oru.sePublications
Change search
Refine search result
1 - 28 of 28
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Asfaw Idosa, Berhane
    et al.
    Örebro University, School of Medical Sciences. iRiSC-Inflammatory Response and Infection Susceptibility Centre.
    Kelly, Anne
    iRiSC-Inflammatory Response and Infection Susceptibility Centre, Faculty of Medicine and Health, Örebro University, Örebro, Sweden; Karolinska University Hospital, Solna, Stockholm, Sweden.
    Jacobsson, Susanne
    Örebro University, School of Medical Sciences. Örebro University Hospital. iRiSC-Inflammatory Response and Infection Susceptibility Centre.
    Demirel, Isak
    Örebro University, School of Medical Sciences. iRiSC-Inflammatory Response and Infection Susceptibility Centre.
    Fredlund, Hans
    iRiSC-Inflammatory Response and Infection Susceptibility Centre.
    Särndahl, Eva
    Örebro University, School of Medical Sciences. iRiSC-Inflammatory Response and Infection Susceptibility Centre.
    Persson, Alexander
    Örebro University, School of Medical Sciences. iRiSC-Inflammatory Response and Infection Susceptibility Centre.
    Neisseria meningitidis-Induced Caspase-1 Activation in Human Innate Immune Cells Is LOS-Dependent2019In: Journal of Immunology Research, ISSN 2314-8861, E-ISSN 2314-7156, article id 6193186Article in journal (Refereed)
    Abstract [en]

    Meningococcal disease such as sepsis and meningitidis is hallmarked by an excessive inflammatory response. The causative agent, Neisseria meningitidis, expresses the endotoxin lipooligosaccharide (LOS) that is responsible for activation of immune cells and the release of proinflammatory cytokines. One of the most potent proinflammatory cytokines, interleukin-1 (IL-1), is activated following caspase-1 activity in the intracellular multiprotein complex called inflammasome. Inflammasomes are activated by a number of microbial factors as well as danger molecules by a two-step mechanismpriming and licensing of inflammasome activationbut there are no data available regarding a role for inflammasome activation in meningococcal disease. The aim of this study was to investigate if N. meningitidis activates the inflammasome and, if so, the role of bacterial LOS in this activation. Cells were subjected to N. meningitidis, both wild-type (FAM20) and its LOS-deficient mutant (lpxA), and priming as well as licensing of inflammasome activation was investigated. The wild-type LOS-expressing parental FAM20 serogroup C N. meningitidis (FAM20) strain significantly enhanced the caspase-1 activity in human neutrophils and monocytes, whereas lpxA was unable to induce caspase-1 activity as well as to induce IL-1 release. While the lpxA mutant induced a priming response, measured as increased expression of NLRP3 and IL1B, the LOS-expressing FAM20 further increased this priming. We conclude that although non-LOS components of N. meningitidis contribute to the priming of the inflammasome activity, LOS per se is to be considered as the central component of N. meningitidis virulence, responsible for both priming and licensing of inflammasome activation.

  • 2.
    Asfaw Idosa, Berhane
    et al.
    Örebro University, School of Medical Sciences.
    Persson, Alexander
    Örebro University, School of Medical Sciences.
    Jacobsson, Susanne
    Örebro University, School of Medical Sciences.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Fredlund, Hans
    Örebro University, School of Medical Sciences.
    Särndahl, Eva
    Örebro University, School of Medical Sciences.
    Kelly, Anne
    Karolinska University Hospital, Stockholm, Sweden.
    LOS-dependent Neisseria meningitidis-induced caspase-1 activation in human neutrophilsManuscript (preprint) (Other academic)
  • 3.
    Bang, Charlotte Sahlberg
    et al.
    Örebro University, School of Health Sciences.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Kruse, Robert
    Örebro University, School of Medical Sciences.
    Persson, Katarina
    Örebro University, School of Medical Sciences.
    Global gene expression profiling and antibiotic susceptibility after repeated exposure to the carbon monoxide-releasing molecule-2 (CORM-2) in multidrug-resistant ESBL-producing uropathogenic Escherichia coli2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 6, article id e0178541Article in journal (Refereed)
    Abstract [en]

    Treatment of urinary tract infections is today a challenge due to the increasing prevalence of multidrug-resistant ESBL-producing uropathogenic Escherichia coli (UPEC). There is an urgent need for new treatment strategies for multidrug-resistant UPEC and preferably with targets that have low potential for development of resistance. Carbon monoxide-releasing molecules (CORMs) are novel and potent antibacterial agents. The present study examines the transcriptomic targets of CORM-2 in a multidrug-resistant ESBL-producing UPEC isolate in response to a single exposure to CORM-2 and after repeated exposure to CORM-2. The bacterial viability and minimal inhibitory concentration (MIC) were also examined after repeated exposure to CORM-2. Microarray analysis revealed that a wide range of processes were affected by CORM-2, including a general trend of down-regulation in energy metabolism and biosynthesis pathways and up-regulation of the SOS response and DNA repair. Several genes involved in virulence (ibpB), antibiotic resistance (marAB, mdtABC) and biofilm formation (bhsA, yfgF) were up-regulated, while some genes involved in virulence (kpsC, fepCEG, entABE), antibiotic resistance (evgA) and biofilm formation (artIP) were down-regulated. Repeated exposure to CORM-2 did not alter the gene expression patterns, the growth inhibitory response to CORM-2 or the MIC values for CORM-2, cefotaxime, ciprofloxacin and trimethoprim. This study identifies several enriched gene ontologies, modified pathways and single genes that are targeted by CORM-2 in a multidrug-resistant UPEC isolate. Repeated exposure to CORM-2 did not change the gene expression patterns or fold changes and the susceptibility to CORM-2 remained after repeated exposure.

  • 4.
    Bang, Charlotte Sahlberg
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Kruse, Robert
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Örebro University Hospital.
    Demirel, Isak
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Önnberg, Anna
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Dept Lab Med, Örebro University Hospital, Örebro, Sweden.
    Söderquist, Bo
    Örebro University, School of Medicine, Örebro University, Sweden. Örebro University Hospital. Dept Lab Med, Örebro University Hospital, Örebro, Sweden.
    Persson, Katarina
    Örebro University, School of Medicine, Örebro University, Sweden.
    Multiresistant uropathogenic extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are susceptible to the carbon monoxide releasing molecule-2 (CORM-2).2014In: Microbial Pathogenesis, ISSN 0882-4010, E-ISSN 1096-1208, Vol. 66, p. 29-35Article in journal (Refereed)
    Abstract [en]

    Carbon monoxide (CO) releasing molecules (CO-RMs) have been shown to inhibit growth of commensal Escherichia coli (E. coli). In the present study we examined the effect of CORM-2 on uropathogenic E. coli (UPEC) that produces extended-spectrum β-lactamase (ESBL). Viability experiments showed that CORM-2 inhibited the growth of several different ESBL-producing UPEC isolates and that 500 μM CORM-2 had a bactericidal effect within 4 h. The bactericidal effect of CORM-2 was significantly more pronounced than the effect of the antibiotic nitrofurantoin. CORM-2 demonstrated a low level of cytotoxicity in eukaryotic cells (human bladder epithelial cell line 5637) at the concentrations and time-points where the antibacterial effect was obtained. Real-time RT-PCR studies of different virulence genes showed that the expression of capsule group II kpsMT II and serum resistance traT was reduced and that some genes encoding iron acquisition systems were altered by CORM-2. Our results demonstrate that CORM-2 has a fast bactericidal effect against multiresistant ESBL-producing UPEC isolates, and also identify some putative UPEC virulence factors as targets for CORM-2. CO-RMs may be candidate drugs for further studies in the field of finding new therapeutic approaches for treatment of uropathogenic ESBLproducing E. coli.

  • 5.
    Demirel, Isak
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Uropathogenic Esherichia coli, multidrug-resistance and induction of host defense mechanisms2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Uropathogenic Escherichia coli (UPEC) is the primary cause of urinary tract infection (UTI), which is one of the most common infections in humans. UPEC strains have acquired successful strategies to subvert the host defense and antibiotics to persist in the urinary tract. The main aim of this thesis was to investigate the host defense mechanisms during a UPEC infection in vitro.

    The results showed that SOCS3, a key regulator of the immune system, was increased in bladder epithelial cells in response to a UPEC infection. In addition, UPEC decreased the phosphorylation of the SOCS3 regulated transcription factor STAT3. Nitric oxide (NO), a host-derived antimicrobial factor was shown to increase the release of IL-6 from renal epithelial cells alone or in combination with UPEC. The induction of IL-6 was mediated by ERK1/2 and p38 MAPK signaling and NO was also shown to attenuate UPEC-induced IL-6 mRNA degradation. Furthermore, extended-spectrum beta-lactamase (ESBL)-producing UPEC isolates were shown to induce higher PMN migration and ROS-production, but lower cytokine secretion from renal epithelial cells than susceptible isolates. Ineffective ceftibuten treatment of ESBL isolates induced bacterial filamentation associated with an increased release of ATP and LPS, with a subsequent enhancement of the ESBL evoked host response.

    Taken together, the findings show that UPEC can induce SOCS3, a suppressor of host responses and that NO can regulate proinflammatory mediators. In addition, the data suggest that there are differences between ESBL- and non-ESBL-producing isolates ability to evoke a host response. Exposing resistant isolates to ineffective antibiotics was shown to alter the evoked host response.

    List of papers
    1. Expression of suppressor of cytokine signalling 3 (SOCS3) in human bladder epithelial cells infected with uropathogenic Escherichia coli
    Open this publication in new window or tab >>Expression of suppressor of cytokine signalling 3 (SOCS3) in human bladder epithelial cells infected with uropathogenic Escherichia coli
    2013 (English)In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 121, no 2, p. 158-167Article in journal (Refereed) Published
    Abstract [en]

    Suppressor of cytokine signalling (SOCS) proteins inhibit pro-inflammatory signalling mediated by Janus-activated kinase (JAK)-signal transducer and activator of transcription (STAT) pathways. To evade the immune response some pathogens appear to modify the host SOCS proteins. Uropathogenic Escherichia coli (UPEC) are able to subvert the host response evoked by bladder epithelial cells, but the mechanisms are not fully understood. The objective of this study was to investigate whether UPEC can modify the host SOCS and STAT3 response. Real time RT-PCR studies demonstrated an increased SOCS1 and SOCS3 expression in the isolated human bladder epithelial cell lines (RT-4 and 5637) in response to cytokines. UPEC strain IA2 increased SOCS3, but not SOCS1, mRNA levels with a peak at 6 h after infection. The increase of SOCS3 was confirmed at the protein level by Western blotting. The UPEC strain IA2 caused a time-dependent decrease in the phosphorylation of STAT3. This study demonstrates that UPEC are able to affect SOCS3 and STAT3 signalling in human uroepithelial cells. The finding that UPEC are able to induce mediators involved in suppression of host cytokine signalling may help to elucidate how UPEC may circumvent the host response during urinary tract infection.

    Place, publisher, year, edition, pages
    Wiley-Blackwell, 2013
    National Category
    Medical and Health Sciences
    Research subject
    Medicine
    Identifiers
    urn:nbn:se:oru:diva-26375 (URN)10.1111/j.1600-0463.2012.02951.x (DOI)000313830700010 ()23030674 (PubMedID)
    Note

    Funding Agency:

    Swedish Medical Research Council 65X-12601-11 

    Faculty of Medicine and Health at Örebro University 

    Available from: 2012-11-07 Created: 2012-11-07 Last updated: 2017-12-07Bibliographically approved
    2. Nitric oxide activates IL-6 production and expression in human renal epithelial cells
    Open this publication in new window or tab >>Nitric oxide activates IL-6 production and expression in human renal epithelial cells
    Show others...
    2012 (English)In: American Journal of Nephrology, ISSN 0250-8095, E-ISSN 1421-9670, Vol. 36, no 6, p. 524-530Article in journal (Refereed) Published
    Abstract [en]

    Background/Aims: Increased nitric oxide (NO) production or inducible form of NO synthase activity have been documented in patients suffering from urinary tract infection (UTI), but the role of NO in this infection is unclear. We investigated whether NO can affect the host response in human renal epithelial cells by modulating IL-6 production and mRNA expression.

    Methods: The human renal epithelial cell line A498 was infected with a uropathogenic Escherichia coli (UPEC) strain and/or the NO donor DETA/NO. The IL-6 production and mRNA expression were evaluated by ELISA and real-time RT-PCR. IL-6 mRNA stability was evaluated by analyzing mRNA degradation by real-time RT-PCR.

    Results: DETA/NO caused a significant (p < 0.05) increase in IL-6 production. Inhibitors of p38 MAPK and ERK1/2 signaling, but not JNK, were shown to significantly suppress DETA/NO-induced IL-6 production. UPEC-induced IL-6 production was further increased (by 73 ± 23%, p < 0.05) in the presence of DETA/NO. The IL-6 mRNA expression increased 2.1 ± 0.17-fold in response to DETA/NO, while the UPEC-evoked increase was pronounced (20 ± 4.5-fold). A synergistic effect of DETA/NO on UPEC-induced IL-6 expression was found (33 ± 7.2-fold increase). The IL-6 mRNA stability studies showed that DETA/NO partially attenuated UPEC-induced degradation of IL-6 mRNA.

    Conclusions: NO was found to stimulate IL-6 in renal epithelial cells through p38 MAPK and ERK1/2 signaling pathways and also to increase IL-6 mRNA stability in UPEC-infected cells. This study proposes a new role for NO in the host response during UTI by modulating the transcription and production of the cytokine IL-6.

    Place, publisher, year, edition, pages
    Basel, Switzerland: S. Karger, 2012
    Keywords
    Nitric oxide, urinary tract infections, il-6, mapk signaling, renal epithelial cells
    National Category
    Medical and Health Sciences Microbiology in the medical area
    Research subject
    Medicine
    Identifiers
    urn:nbn:se:oru:diva-26534 (URN)10.1159/000345351 (DOI)000312916200004 ()23183248 (PubMedID)2-s2.0-84869889861 (Scopus ID)
    Available from: 2012-11-28 Created: 2012-11-28 Last updated: 2018-01-12Bibliographically approved
    3. Comparison of host response mechanisms evoked by extended spectrum beta lactamase (ESBL)- and non-ESBL-producing uropathogenic E. coli
    Open this publication in new window or tab >>Comparison of host response mechanisms evoked by extended spectrum beta lactamase (ESBL)- and non-ESBL-producing uropathogenic E. coli
    Show others...
    2013 (English)In: BMC Microbiology, ISSN 1471-2180, E-ISSN 1471-2180, Vol. 13, article id 181Article in journal (Refereed) Published
    Abstract [en]

    Background: Infections caused by extended spectrum beta-lactamases (ESBL)-producing bacteria have been emerging worldwide and the majority of ESBL-producing E. coli strains are isolated from patients with urinary tracts infections. The purpose of this study was to compare the host-response mechanisms in human polymorphonucleated leukocytes (PMN) and renal epithelial cells when stimulated by ESBL-or non-ESBL-producing uropathogenic E. coli (UPEC) isolates. The host-pathogen interaction of these ESBL-producing strains in the urinary tract is not well studied.

    Results: The ability of ESBL strains to evoke ROS-production from PMN cells was significantly higher than that of the non-ESBL strains. The growth of ESBL strains was slightly suppressed in the presence of PMN compared to non-ESBL strains after 30 min and 2 h, but the opposite was observed after 5 and 6 h. The number of migrating PMN was significantly higher in response to ESBL strains compared to non-ESBL strains. Stimulation of A498 cells with ESBL strains elicited lower production of IL-6 and IL-8 compared to non-ESBL strains.

    Conclusion: Significant differences in host-response mechanisms were identified when host cells were stimulated by ESBL-or non-ESBL producing strains. The obtained results on the early interactions of ESBL-producing strains with the host immune system may provide valuable information for management of these infections.

    Place, publisher, year, edition, pages
    London, United Kingdom: BioMed Central, 2013
    Keywords
    Extended spectrum beta-lactamases, Urinary tract infections, Renal epithelial cells, Polymorphonucleated leukocytes, Uropathogenic E. coli
    National Category
    Medical and Health Sciences Microbiology
    Research subject
    Medicine
    Identifiers
    urn:nbn:se:oru:diva-30515 (URN)10.1186/1471-2180-13-181 (DOI)000322659500001 ()24059789 (PubMedID)2-s2.0-84880913688 (Scopus ID)
    Available from: 2013-08-30 Created: 2013-08-30 Last updated: 2018-05-21Bibliographically approved
    4. Antibiotic-induced filamentation of extended spectrum beta lactamase (ESBL)-producing uropathogenic E. coli alters host cell responses during an in vitro infection
    Open this publication in new window or tab >>Antibiotic-induced filamentation of extended spectrum beta lactamase (ESBL)-producing uropathogenic E. coli alters host cell responses during an in vitro infection
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Inadequate and delayed antibiotic treatment of extended spectrum beta-lactamase (ESBL)- producing isolates have been associated with increased mortality of affected patients. The purpose of this study was to compare the host response of human renal epithelial cells and polymorphonuclear leukocyte (PMN) cells when infected by ESBL-producing uropathogenic E. coli (UPEC) isolates in the presence or absence of ineffective antibiotics.

    The renal epithelial cell line A498 and PMN cells were stimulated with ESBLproducing UPEC isolates in the presence or absence of three different antibiotics (trimetoprim, ceftibuten and ciprofloxacin). Host cell responses were evaluated as release of cytokines (IL-6, IL-8), reactive oxygen species (ROS), ATP and endotoxins. Bacterial morphology and PMNphagocytosis were evaluated by microscopy.

    In the presence of ceftibuten, 2 out of 3 examined ESBL-isolates changed their morphology into a filamentous form. The presence of ceftibuten enhanced IL-6, IL-8 and ROS-production from host cells, but only from cells stimulated by the filamentous isolates. The bacterial supernatant and not the filamentous bacteria per se was responsible for the increased release of IL-6, IL-8 and ROS. Increased endotoxin and ATP levels were found in the bacterial supernatants from filamentous isolates. Apyrase decreased IL-6 secretion from A498 cells and polymyxin B abolished the increased ROS production from PMN cells. PMN were able to inhibit the bacterial growth of some ESBL-isolates in the presence of ceftibuten. In conclusion, antibiotic-induced filamentation of ESBL-producing UPEC isolates and the associated release of ATP and endotoxins can alter the host cell response in the urinary tract.

    Keywords
    urinary tract infections, renal epithelial cells, polymorphonucleated leukocytes, uropathogenic E. coli, extended spectrum beta-lactamases, filamentous bacteria
    National Category
    Medical and Health Sciences
    Research subject
    Biomedicine
    Identifiers
    urn:nbn:se:oru:diva-34891 (URN)
    Available from: 2014-04-28 Created: 2014-04-28 Last updated: 2017-10-17Bibliographically approved
  • 6.
    Demirel, Isak
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Kinnunen, Annica
    Örebro University, School of Science and Technology.
    Önnberg, Anna
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Laboratory Medicine, Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Söderquist, Bo
    Örebro University, School of Medicine, Örebro University, Sweden. Department of Laboratory Medicine, Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Persson, Katarina
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Comparison of host response mechanisms evoked by extended spectrum beta lactamase (ESBL)- and non-ESBL-producing uropathogenic E. coli2013In: BMC Microbiology, ISSN 1471-2180, E-ISSN 1471-2180, Vol. 13, article id 181Article in journal (Refereed)
    Abstract [en]

    Background: Infections caused by extended spectrum beta-lactamases (ESBL)-producing bacteria have been emerging worldwide and the majority of ESBL-producing E. coli strains are isolated from patients with urinary tracts infections. The purpose of this study was to compare the host-response mechanisms in human polymorphonucleated leukocytes (PMN) and renal epithelial cells when stimulated by ESBL-or non-ESBL-producing uropathogenic E. coli (UPEC) isolates. The host-pathogen interaction of these ESBL-producing strains in the urinary tract is not well studied.

    Results: The ability of ESBL strains to evoke ROS-production from PMN cells was significantly higher than that of the non-ESBL strains. The growth of ESBL strains was slightly suppressed in the presence of PMN compared to non-ESBL strains after 30 min and 2 h, but the opposite was observed after 5 and 6 h. The number of migrating PMN was significantly higher in response to ESBL strains compared to non-ESBL strains. Stimulation of A498 cells with ESBL strains elicited lower production of IL-6 and IL-8 compared to non-ESBL strains.

    Conclusion: Significant differences in host-response mechanisms were identified when host cells were stimulated by ESBL-or non-ESBL producing strains. The obtained results on the early interactions of ESBL-producing strains with the host immune system may provide valuable information for management of these infections.

  • 7.
    Demirel, Isak
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Kruse, Robert
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Önnberg, Anna
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Laboratory Medicine, Clinical Microbiology, Örebro University Hospital, Örebro, Sweden.
    Persson, Katarina
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Antibiotic-induced filamentation of extended spectrum beta lactamase (ESBL)-producing uropathogenic E. coli alters host cell responses during an in vitro infectionManuscript (preprint) (Other academic)
    Abstract [en]

    Inadequate and delayed antibiotic treatment of extended spectrum beta-lactamase (ESBL)- producing isolates have been associated with increased mortality of affected patients. The purpose of this study was to compare the host response of human renal epithelial cells and polymorphonuclear leukocyte (PMN) cells when infected by ESBL-producing uropathogenic E. coli (UPEC) isolates in the presence or absence of ineffective antibiotics.

    The renal epithelial cell line A498 and PMN cells were stimulated with ESBLproducing UPEC isolates in the presence or absence of three different antibiotics (trimetoprim, ceftibuten and ciprofloxacin). Host cell responses were evaluated as release of cytokines (IL-6, IL-8), reactive oxygen species (ROS), ATP and endotoxins. Bacterial morphology and PMNphagocytosis were evaluated by microscopy.

    In the presence of ceftibuten, 2 out of 3 examined ESBL-isolates changed their morphology into a filamentous form. The presence of ceftibuten enhanced IL-6, IL-8 and ROS-production from host cells, but only from cells stimulated by the filamentous isolates. The bacterial supernatant and not the filamentous bacteria per se was responsible for the increased release of IL-6, IL-8 and ROS. Increased endotoxin and ATP levels were found in the bacterial supernatants from filamentous isolates. Apyrase decreased IL-6 secretion from A498 cells and polymyxin B abolished the increased ROS production from PMN cells. PMN were able to inhibit the bacterial growth of some ESBL-isolates in the presence of ceftibuten. In conclusion, antibiotic-induced filamentation of ESBL-producing UPEC isolates and the associated release of ATP and endotoxins can alter the host cell response in the urinary tract.

  • 8.
    Demirel, Isak
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Kruse, Robert
    Örebro University, School of Medicine, Örebro University, Sweden.
    Önnberg, Anna
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Persson, Katarina
    Örebro University, School of Medicine, Örebro University, Sweden.
    Ceftibuten-induced filamentation of extended spectrum beta lactamase (ESBL)-producing uropathogenic Escherichia coli alters host cell responses during an in vitro infection2015In: Microbial Pathogenesis, ISSN 0882-4010, E-ISSN 1096-1208, Vol. 78, p. 52-62Article in journal (Refereed)
    Abstract [en]

    Inadequate and delayed antibiotic treatment of extended spectrum beta-lactamase (ESBL)-producing isolates have been associated with increased mortality of affected patients. The purpose of this study was to compare the host response of human renal epithelial cells and polymorphonuclear leucocyte (PMN) cells when infected by ESBL-producing uropathogenic Escherichia coli (UPEC) isolates in the presence or absence of ineffective antibiotics.

    The renal epithelial cell line A498 and PMN cells were stimulated with ESBL-producing UPEC isolates in the presence or absence of three different antibiotics (trimetoprim, ceftibuten and ciprofloxacin). Host cell responses were evaluated as release of cytokines (IL-6, IL-8), reactive oxygen species (ROS), ATP and endotoxins. Bacterial morphology and PMN phagocytosis were evaluated by microscopy.

    In the presence of ceftibuten, 2 out of 3 examined ESBL-isolates changed their morphology into a filamentous form. The presence of ceftibuten enhanced IL-6, IL-8 and ROS-production from host cells, but only from cells stimulated by the filamentous isolates. The bacterial supernatant and not the filamentous bacteria per se was responsible for the increased release of IL-6, IL-8 and ROS. Increased endotoxin and ATP levels were found in the bacterial supernatants from filamentous isolates. Apyrase decreased IL-6 secretion from A498 cells and polymyxin B abolished the increased ROS-production from PMN cells. PMN were able to inhibit the bacterial growth of some ESBL-isolates in the presence of ceftibuten.

    In conclusion, antibiotic-induced filamentation of ESBL-producing UPEC isolates and the associated release of ATP and endotoxins can alter the host cell response in the urinary tract.

  • 9.
    Demirel, Isak
    et al.
    Örebro University, School of Medical Sciences.
    Persson, Alexander
    Örebro University, School of Medical Sciences.
    Brauner, Annelie
    Department of Microbiology, Tumor and Cell Biology, Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
    Särndahl, Eva
    Örebro University, School of Medical Sciences.
    Kruse, Robert
    Örebro University, School of Medical Sciences. Department of Clinical Research Laboratory, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Persson, Katarina
    Örebro University, School of Medical Sciences.
    Activation of the NLRP3 Inflammasome Pathway by Uropathogenic Escherichia coli Is Virulence Factor-Dependent and Influences Colonization of Bladder Epithelial Cells2018In: Frontiers in Cellular and Infection Microbiology, E-ISSN 2235-2988, Vol. 8, article id 81Article in journal (Refereed)
    Abstract [en]

    The NLRP3 inflammasome and IL-1 beta release have recently been suggested to be important for the progression of urinary tract infection (UTI). However, much is still unknown regarding the interaction of UPEC and the NLRP3 inflammasome. The purpose of this study was to elucidate what virulence factors uropathogenic Escherichia coil (UPEC) use to modulate NLRP3 inflammasome activation and subsequent IL-1 beta release and the role of NLRP3 for UPEC colonization of bladder epithelial cells. The bladder epithelial cell line 5637, CRISPR/Cas9 generated NLRP3, caspase-1 and mesotrypsin deficient cell lines and transformed primary bladder epithelial cells (HBLAK) were stimulated with UPEC isolates and the non-pathogenic MG1655 strain. We found that the UPEC strain CFT073, but not MG1655, induced an increased caspase-1 activity and IL-1 beta release from bladder epithelial cells. The increase was shown to be mediated by et-hemolysin activation of the NLRP3 inflammasome in an NE-kappa B-independent manner. The effect of-hemolysin on IL-1 beta release was biphasic, initially suppressive, later inductive. Furthermore, the phase-locked type-1-fimbrial ON variant of CFT073 inhibited caspase-1 activation and IL-1 beta release. In addition, the ability of CFT073 to adhere to and invade NLRP3 deficient cells was significantly reduced compare to wild-type cells. The reduced colonization of NLRP3-deficient cells was type-1 fimbriae dependent. In conclusion, we found that the NLRP3 inflammasome was important for type-1 fimbriae-dependent colonization of bladder epithelial cells and that both type-1 fimbriae and alpha-hemolysin can modulate the activity of the NLRP3 inflammasome.

  • 10.
    Demirel, Isak
    et al.
    Örebro University, School of Medical Sciences. Inflammatory Response and Infection Susceptibility Centre.
    Rangel, Ignacio
    Örebro University, School of Medical Sciences.
    Petersson, Ulrika
    School of Medical Sciences, Örebro University, Örebro, Sweden.
    Persson, Katarina
    Örebro University, School of Medical Sciences. Faculty of Medicine and Health, Inflammatory Response and Infection Susceptibility Centre, Örebro University, Örebro, Sweden.
    Kruse, Robert
    Örebro University, School of Medical Sciences. Faculty of Medicine and Health, Inflammatory Response and Infection Susceptibility Centre, Örebro University, Örebro, Sweden; Department of Clinical Research Laboratory, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Transcriptional Alterations of Virulence-Associated Genes in Extended Spectrum Beta-Lactamase (ESBL)-Producing Uropathogenic Escherichia coli during Morphologic Transitions Induced by Ineffective Antibiotics2017In: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 8, article id 1058Article in journal (Refereed)
    Abstract [en]

    It is known that an ineffective antibiotic treatment can induce morphological shifts in uropathogenic Escherichia coli (UPEC) but the virulence properties during these shifts remain to be studied. The present study examines changes in global gene expression patterns and in virulence factor-associated genes in an extended spectrum beta-lactamase (ESBL)-producing UPEC (ESBL019) during the morphologic transitions induced by an ineffective antibiotic and in the presence of human primary bladder epithelial cells. Microarray results showed that the different morphological states of ESBL019 had significant transcriptional alterations of a large number of genes (Transition; 7%, Filamentation; 32%, and Reverted 19% of the entities on the array). All three morphological states of ESBL019 were associated with a decreased energy metabolism, altered iron acquisition systems and altered adhesion expression. In addition, genes associated with LPS synthesis and bacterial motility was also altered in all the morphological states. Furthermore, the transition state induced a significantly higher release of TNF-alpha from bladder epithelial cells compared to all other morphologies, while the reverted state was unable to induce INF-alpha release. Our findings show that the morphological shifts induced by ineffective antibiotics are associated with significant transcriptional virulence alterations in ESBL-producing UPEC, which may affect survival and persistence in the urinary tract.

  • 11.
    Demirel, Isak
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Säve, Susanne
    School of Natural Sciences, Linnaeus University, Kalmar, Sweden.
    Kruse, Robert
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Persson, Katarina
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Expression of suppressor of cytokine signalling 3 (SOCS3) in human bladder epithelial cells infected with uropathogenic Escherichia coli2013In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 121, no 2, p. 158-167Article in journal (Refereed)
    Abstract [en]

    Suppressor of cytokine signalling (SOCS) proteins inhibit pro-inflammatory signalling mediated by Janus-activated kinase (JAK)-signal transducer and activator of transcription (STAT) pathways. To evade the immune response some pathogens appear to modify the host SOCS proteins. Uropathogenic Escherichia coli (UPEC) are able to subvert the host response evoked by bladder epithelial cells, but the mechanisms are not fully understood. The objective of this study was to investigate whether UPEC can modify the host SOCS and STAT3 response. Real time RT-PCR studies demonstrated an increased SOCS1 and SOCS3 expression in the isolated human bladder epithelial cell lines (RT-4 and 5637) in response to cytokines. UPEC strain IA2 increased SOCS3, but not SOCS1, mRNA levels with a peak at 6 h after infection. The increase of SOCS3 was confirmed at the protein level by Western blotting. The UPEC strain IA2 caused a time-dependent decrease in the phosphorylation of STAT3. This study demonstrates that UPEC are able to affect SOCS3 and STAT3 signalling in human uroepithelial cells. The finding that UPEC are able to induce mediators involved in suppression of host cytokine signalling may help to elucidate how UPEC may circumvent the host response during urinary tract infection.

  • 12.
    Demirel, Isak
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Vumma, Ravi
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Mohlin, Camilla
    School of Natural Sciences, Linnaeus University, Kalmar, Sweden.
    Svensson, Lovisa
    School of Natural Sciences, Linnaeus University, Kalmar, Sweden; Department of Medical Sciences, Uppsala University, Uppsala , Sweden.
    Säve, Susanne
    School of Natural Sciences, Linnaeus University, Kalmar, Sweden.
    Persson, Katarina
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. School of Natural Sciences, Linnaeus University, Kalmar, Sweden.
    Nitric oxide activates IL-6 production and expression in human renal epithelial cells2012In: American Journal of Nephrology, ISSN 0250-8095, E-ISSN 1421-9670, Vol. 36, no 6, p. 524-530Article in journal (Refereed)
    Abstract [en]

    Background/Aims: Increased nitric oxide (NO) production or inducible form of NO synthase activity have been documented in patients suffering from urinary tract infection (UTI), but the role of NO in this infection is unclear. We investigated whether NO can affect the host response in human renal epithelial cells by modulating IL-6 production and mRNA expression.

    Methods: The human renal epithelial cell line A498 was infected with a uropathogenic Escherichia coli (UPEC) strain and/or the NO donor DETA/NO. The IL-6 production and mRNA expression were evaluated by ELISA and real-time RT-PCR. IL-6 mRNA stability was evaluated by analyzing mRNA degradation by real-time RT-PCR.

    Results: DETA/NO caused a significant (p < 0.05) increase in IL-6 production. Inhibitors of p38 MAPK and ERK1/2 signaling, but not JNK, were shown to significantly suppress DETA/NO-induced IL-6 production. UPEC-induced IL-6 production was further increased (by 73 ± 23%, p < 0.05) in the presence of DETA/NO. The IL-6 mRNA expression increased 2.1 ± 0.17-fold in response to DETA/NO, while the UPEC-evoked increase was pronounced (20 ± 4.5-fold). A synergistic effect of DETA/NO on UPEC-induced IL-6 expression was found (33 ± 7.2-fold increase). The IL-6 mRNA stability studies showed that DETA/NO partially attenuated UPEC-induced degradation of IL-6 mRNA.

    Conclusions: NO was found to stimulate IL-6 in renal epithelial cells through p38 MAPK and ERK1/2 signaling pathways and also to increase IL-6 mRNA stability in UPEC-infected cells. This study proposes a new role for NO in the host response during UTI by modulating the transcription and production of the cytokine IL-6.

  • 13.
    Engelsöy, Ulrik
    et al.
    School of Medical Sciences, Örebro University, Örebro, Sweden.
    Rangel, Ignacio
    Örebro University, School of Medical Sciences. Nutrition-Gut-Brain Interactions Research Centre.
    Demirel, Isak
    Örebro University, School of Medical Sciences. iRiSC - Inflammatory Response and Infection Susceptibility Centre.
    Impact of Proinflammatory Cytokines on the Virulence of Uropathogenic Escherichia coli2019In: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 10, article id 1051Article in journal (Refereed)
    Abstract [en]

    The effect of a urinary tract infection on the host is a well-studied research field. However, how the host immune response affects uropathogenic Escherichia coli (CFT073) virulence is less studied. The aim of the present study was to investigate the impact of proinflammatory cytokine exposure on the virulence of uropathogenic Escherichia coli. We found that all tested proinflammatory cytokines (TNF-alpha, IL-1 beta, IL-6, IL-8 and IFN-gamma) induced an increased CFT073 growth. We also found that biofilm formation and hemolytic activity was reduced in the presence of all proinflammatory cytokines. However, a reduction in siderophore release was only observed in the presence of IL-1 beta, IL-6 and IL-8. Real time-qPCR showed that all proinflammatory cytokines except TNF-alpha significantly increased genes associated with the iron acquisition system in CFT073. We also found that the proinflammatory cytokines induced significant changes in type-1 fimbriae, P-fimbriae and gluconeogenetic genes. Furthermore, we also showed, using a Caenorhabditis elegans (C. elegans) killing assay that all cytokines decreased the survival of C. elegans worms significantly. Taken together, our findings show that proinflammatory cytokines have the ability to alter the virulence traits of UPEC.

  • 14.
    Jayaprakash, Kartheyaene
    et al.
    Örebro University, School of Medical Sciences.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Gunaltay, Sezin
    Örebro University, School of Medical Sciences.
    Khalaf, Hazem
    Örebro University, School of Medical Sciences.
    Bengtsson, Torbjörn
    Örebro University, School of Medical Sciences.
    PKC, ERK/p38 MAP kinases and NF-B targeted signalling play a role in the expression and release of IL-1β  and CXCL8 in Porphyromonas gingivalis-infected THP1 cells2017In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 125, no 7, p. 623-633Article in journal (Refereed)
    Abstract [en]

    Porphyromonas gingivalis is a keystone pathogen in periodontitis and is gaining importance in cardiovascular pathogenesis. Protease-activated receptors (PARs), toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD) on monocytes recognize the structural components on P. gingivalis, inducing inflammatory intermediates. Here, we elucidate the modulation of PARs, TLRs, NODs, and the role of MAPK and NF-B in IL-1 and CXCL8 release. THP1 cells were stimulated with P. gingivalis wild-type W50 and its isogenic gingipain mutants: Rgp mutant E8 and Kgp mutant K1A. We observed modulation of PARs, TLRs, NOD, IL-1 and CXCL8 expression by P. gingivalis. Gingipains hydrolyse IL-1 and CXCL8, which is more evident for IL-1 accumulation at 24 h. Inhibition of PKC (protein kinase C), p38 and ERK (extracellular signal-regulated kinases) partially reduced P. gingivalis-induced IL-1 at 6 h, whereas PKC and ERK reduced CXCL8 at both 6 and 24 h. Following NF-B inhibition, P. gingivalis-induced IL-1 and CXCL8 were completely suppressed to basal levels. Overall, TLRs, PARs and NOD possibly act in synergy with PKC, MAPK ERK/p38 and NF-B in P. gingivalis-induced IL-1 and CXCL8 release from THP1 cells. These pro-inflammatory cytokines could affect leucocytes in circulation and exacerbate other vascular inflammatory conditions such as atherosclerosis.

  • 15.
    Jayaprakash, Kartheyaene
    et al.
    Örebro University, School of Medical Sciences.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Gunaltay, Sezin
    Örebro University, School of Medical Sciences.
    Khalaf, Hazem
    Örebro University, School of Medical Sciences.
    Bengtsson, Torbjörn
    Örebro University, School of Medical Sciences.
    PKC, ERK/p38 MAP kinases and NF-κB targeted signalling plays a crucial role in expression and release of IL-1β and CXCL8 in Porphyromonas gingivalis infected monocytesManuscript (preprint) (Other academic)
  • 16.
    Jayaprakash, Kartheyaene
    et al.
    Örebro University, School of Medical Sciences.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Khalaf, Hazem
    Örebro University, School of Medical Sciences.
    Bengtsson, Torbjörn
    Örebro University, School of Medical Sciences.
    Porphyromonas gingivalis induced release of reactive oxygen species and interleukin-1 beta and the effects of low density lipoproteins in monocytes and whole bloodManuscript (preprint) (Other academic)
  • 17.
    Jayaprakash, Kartheyaene
    et al.
    Department of Medical Sciences, Örebro University, Örebro, Sweden.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Khalaf, Hazem
    Örebro University, School of Medical Sciences.
    Bengtsson, Torbjörn
    Örebro University, School of Medical Sciences.
    Porphyromonas gingivalis-induced inflammatory responses in THP1 cells are altered by native and modified low-density lipoproteins in a strain-dependent manner2018In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 126, no 8, p. 667-677Article in journal (Refereed)
    Abstract [en]

    Strong epidemiological evidence supports an association between cardiovascular and periodontal disease and furthermore, the periodontopathogen Porphyromonas gingivalis has been identified in blood and from atheromatous plaques. Blood exposed to P.gingivalis shows an increased protein modification of low-density lipoprotein (LDL). In this study, we investigate the inflammatory responses of THP1 cells incubated with P.gingivalis and the effects of native or modified LDL on these responses. Reactive oxygen species (ROS) and IL-1 were observed in THP1 cells following infection with P.gingivalis ATCC33277 and W50. Caspase 1 activity was quantified in THP1 cells and correlated with IL-1 accumulation. Oxidized LDL (oxLDL) induced IL-1 release and CD36 expression on THP1 cells. Modified LDL co-stimulated with ATCC33277 exhibited regulatory effects on caspase 1 activity, IL-1 release and CD36 expression in THP1 cells, whereas W50 induced more modest responses in THP1 cells. In summary, we show that P.gingivalis is capable of inducing pro-inflammatory responses in THP1 cells, and native and modified LDL could alter these responses in a dose- and strain-dependent manner. Strain-dependent differences in THP1 cell responses could be due to the effect of P.gingivalis proteases, presence or absence of capsule and proteolytic transformation of native and modified LDL.

  • 18.
    Jayaprakash, Kartheyaene
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Demirel, Isak
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Khalaf, Hazem
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Bengtsson, Torbjörn
    Örebro University, School of Medicine, Örebro University, Sweden.
    The role of phagocytosis, oxidative burst and neutrophil extracellular traps in the interaction between neutrophils and the periodontal pathogen Porphyromonas gingivalis2015In: Molecular Oral Microbiology, ISSN 2041-1006, E-ISSN 2041-1014, Vol. 30, no 5, p. 361-375Article in journal (Refereed)
    Abstract [en]

    Neutrophils are regarded as the sentinel cells of innate immunity and are found in abundance within the gingival crevice. Discovery of neutrophil extracellular traps (NETs) within the gingival pockets prompted us to probe the nature of the interactions of neutrophils with the prominent periopathogen Porphyromonas gingivalis. Some of the noted virulence factors of this Gram-negative anaerobe are gingipains: arginine gingipains (RgpA/B) and lysine gingipain (Kgp). The aim of this study was to evaluate the role of gingipains in phagocytosis, formation of reactive oxygen species, NETs and CXCL8 modulation by using wild-type strains and isogenic gingipain mutants. Confocal imaging showed that gingipain mutants K1A (Kgp) and E8 (RgpA/B) induced extracellular traps in neutrophils, whereas ATCC33277 and W50 were phagocytosed. The viability of both ATCC33277 and W50 dwindled as the result of phagocytosis and could be salvaged by cytochalasin D, and the bacteria released high levels of lipopolysaccharide in the culture supernatant. Porphyromonas gingivalis induced reactive oxygen species and CXCL8 with the most prominent effect being that of the wild-type strain ATCC33277, whereas the other wild-type strain W50 was less effective. Quantitative real-time polymerase chain reaction revealed a significant CXCL8 expression by E8. All the tested P.gingivalis strains increased cytosolic free calcium. In conclusion, phagocytosis is the primary neutrophil response to P.gingivalis, although NETs could play an accessory role in infection control. Although gingipains do not seem to directly regulate phagocytosis, NETs or oxidative burst in neutrophils, their proteolytic properties could modulate the subsequent outcomes such as nutrition acquisition and survival by the bacteria.

  • 19.
    Khalaf, Hazem
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Demirel, Isak
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Bengtsson, Torbjörn
    Örebro University, School of Medicine, Örebro University, Sweden.
    Suppression of inflammatory gene expression in T cells by Porphyromonas gingivalis is mediated by targeting MAPK signaling2013In: Cellular & Molecular Immunology, ISSN 1672-7681, E-ISSN 2042-0226, Vol. 10, no 5, p. 413-422Article in journal (Refereed)
    Abstract [en]

    There is increasing awareness of the effects of Porphyromonas gingivalis on host immune responses. Degradation of cytokines and chemokines by cysteine proteinases has previously been reported. However, the precise mechanisms by which P. gingivalis is able to alter intracellular signaling, and thus proliferation and inflammation, have not been described. We have previously reported suppression of activator protein-1 (AP-1) and degradation of IL-2 by proteinases from P. gingivalis. In the present study, we have analyzed the effects of P. gingivalis on Jurkat T-cell signal transduction and subsequent IL-2 and CXCL8 expression. We found that CXCL8, but not IL-2, gene expression levels were significantly suppressed by viable P. gingivalis. Analysis of intracellular signaling revealed an inhibitory effect of P. gingivalis on c-Jun and c-Fos, but not NF kappa B (p50 and p65), NFAT or STAT5 expression. This inhibitory effect was not due to suppression of mitogen-activated protein kinase (MAPK) (p38, erk and JNK) gene expression, but was rather due to prevention of protein kinase C (PKC) and p38 phosphorylation, as demonstrated by western blot analysis. Furthermore, SOCS1 and SOCS3 expression levels decreased following treatment of Jurkat T cells with viable P. gingivalis. The results indicate that P. gingivalis is able to suppress inflammatory gene expression by targeting the activity of MAPK pathways in T cells, which was confirmed by using specific inhibitors of NF-kappa B, PKC, ERK, p38 and JNK.

  • 20.
    Klarström-Engström, Kristin
    et al.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Clinical trial unit.
    Zhang, Boxi
    Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Human renal fibroblasts are strong immunomobilizers during a urinary tract infection mediated by uropathogenic Escherichia coli2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, no 1, article id 2296Article in journal (Refereed)
    Abstract [en]

    To prevent the onset of urosepsis and reduce mortality, a better understanding of how uropathogenic Escherichia coli (UPEC) manages to infiltrate the bloodstream through the kidneys is needed. The present study elucidates if human renal interstitial fibroblasts are part of the immune response limiting a UPEC infection, or if UPEC has the ability to modulate the fibroblasts for their own gain. Microarray results showed that upregulated genes were associated with an activated immune response. We also found that chemokines released from renal fibroblasts upon a UPEC infection could be mediated by LPS and triacylated lipoproteins activating the TLR2/1, TLR4, MAPK, NF-κB and PKC signaling pathways. Furthermore, UPEC was also shown to be able to adhere and invade renal fibroblasts, mediated by the P-fimbriae. Furthermore, it was found that renal fibroblasts were more immunoreactive than renal epithelial cells upon a UPEC infection. However, both renal fibroblasts and epithelial cells were equally efficient at inducing neutrophil migration. In conclusion, we have found that human renal fibroblasts can sense UPEC and mobilize a host response with neutrophil migration. This suggests that renal fibroblasts are not only structural cells that produce and regulate the extracellular matrix, but also highly immunoreactive cells.

  • 21.
    Kruse, Robert
    et al.
    Örebro University, School of Medicine, Örebro University, Sweden. Örebro University Hospital. Faculty of Medicine and Health, Örebro University, Örebro, Sweden; Clinical Research Centre (KFC), Örebro University Hospital, Örebro, Sweden.
    Demirel, Isak
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Säve, Susanne
    School of Natural Sciences, Linnaeus University, Kalmar, Sweden.
    Persson, Katarina
    Örebro University, School of Medicine, Örebro University, Sweden. Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    IL-8 and global gene expression analysis define a key role of ATP in renal epithelial cell responses induced by uropathogenic bacteria2014In: Purinergic Signalling Purinergic Signalling, ISSN 1573-9538, E-ISSN 1573-9546, Vol. 10, no 3, p. 499-508Article in journal (Refereed)
    Abstract [en]

    The recent recognition of receptor-mediated ATP signalling as a pathway of epithelial pro-inflammatory cytokine release challenges the ubiquitous role of the TLR4 pathway during urinary tract infection. The aim of this study was to compare cellular responses of renal epithelial cells infected with uropathogenic Escherichia coli (UPEC) strain IA2 to stimulation with ATP-gamma-S. A498 cells were infected or stimulated in the presence or absence of apyrase, that degrades extracellular ATP, or after siRNA-mediated knockdown of ATP-responding P2Y(2) receptors. Cellular IL-8 release and global gene expression were analysed. Both IA2 and A498 cells per se released ATP, which increased during infection. IA2 and ATP-gamma-S caused a similar to 5-fold increase in cellular release of IL-8 and stimulations performed in the presence of apyrase or after siRNA knockdown of P2Y(2) receptors resulted in attenuation of IA2-mediated IL-8 release. Microarray results show that both IA2 and ATP-gamma-S induced marked changes in gene expression of renal cells. Thirty-six genes were in common between both stimuli, and many of these are key genes belonging to classical response pathways of bacterial infection. Functional analysis shows that 88 biological function-annotated cellular pathways were identical between IA2 and ATP-gamma-S stimuli. Results show that UPEC-induced release of IL-8 is dependent on P2Y(2) signalling and that cellular responses elicited by UPEC and ATP-gamma-S have many identical features. This indicates that renal epithelial responses elicited by bacteria could be mediated by bacteria- or host-derived ATP, thus defining a key role of ATP during infection.

  • 22.
    Lindblad, Anna
    et al.
    Örebro University, School of Medical Sciences.
    Persson, Katarina
    Örebro University, School of Medical Sciences.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    IL-1RA is part of the inflammasome-regulated immune response in bladder epithelial cells and influences colonization of uropathogenic E. coli2019In: Cytokine, ISSN 1043-4666, E-ISSN 1096-0023, Vol. 123, article id 154772Article in journal (Refereed)
    Abstract [en]

    The NLRP3 inflammasome, IL-1β release and pyroptosis (cell lysis) have recently been proposed to be essential for the progression of urinary tract infection (UTI) and elimination of intracellular bacterial niches. However, the effects of IL-1R antagonist (IL-1RA) on immune responses during UTI, except for its ability to disrupt IL-1β signalling, are not well understood. The aim of this study was to investigate the role of IL-1RA in UPEC colonization of bladder epithelial cells and the subsequent host inflammatory response. Human bladder epithelial cells (5637) and CRISPR/Cas9 generated NLRP3 and caspase-1 knockdown cells and IL-1RA knockout cells were stimulated with the UPEC isolate CFT073. The results showed that the UPEC virulence factor α-hemolysin is essential for IL-1RA release, and that the inflammasome-associated proteins caspase-1 and NLRP3 affect the release of IL-1RA. IL-1RA deficient cells showed a reduced adherence and invasion by CFT073 compared to wild-type cells, suggesting that IL-1RA may oppose mechanisms that protects against bacterial colonization. A targeted protein analysis of inflammation-related proteins showed that the basal expression of 23 proteins and the UPEC-induced expression of 10 proteins were significantly altered in IL-1RA deficient bladder epithelial cells compared to Cas9 control cells. This suggests that IL-1RA has a broad effect on the inflammatory response in bladder epithelial cells.

  • 23.
    Lönn, J.
    et al.
    Department of Oral Biology, Institute of Odontology, Malmö University, Malmö, Sweden; PEAS Institute AB, Linköping, Sweden.
    Ljunggren, S.
    Department of Clinical and Experimental Medicine, Occupational and Environmental Medicine Center, Linköping University, Linköping, Sweden.
    Klarström-Engström, Kristin
    Department of Medical Sciences, Örebro University, Örebro, Sweden.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Bengtsson, Torbjörn
    Örebro University, School of Medical Sciences.
    Karlsson, H.
    Department of Clinical and Experimental Medicine, Occupational and Environmental Medicine Center, Linköping University, Linköping, Sweden.
    Lipoprotein modifications by gingipains of Porphyromonas gingivalis2018In: Journal of Periodontal Research, ISSN 0022-3484, E-ISSN 1600-0765, Vol. 53, no 3, p. 403-413Article in journal (Refereed)
    Abstract [en]

    BACKGROUND AND OBJECTIVE: Several studies have shown an association between periodontitis and cardiovascular disease (CVD). Atherosclerosis is the major cause of CVD, and a key event in the development of atherosclerosis is accumulation of lipoproteins within the arterial wall. Bacteria are the primary etiologic agents in periodontitis and Porphyromonas gingivalis is the major pathogen in the disease. Several studies support a role of modified low-density lipoprotein (LDL) in atherogenesis; however, the pathogenic stimuli that induce the changes and the mechanisms by which this occur are unknown. This study aims to identify alterations in plasma lipoproteins induced by the periodontopathic species of bacterium, P. gingivalis, in vitro.

    MATERIAL AND METHODS: Plasma lipoproteins were isolated from whole blood treated with wild-type and gingipain-mutant (lacking either the Rgp- or Kgp gingipains) P. gingivalis by density/gradient-ultracentrifugation and were studied using 2-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ionization mass spectrometry. Porphyromonas gingivalis-induced lipid peroxidation and antioxidant levels were measured by thiobarbituric acid-reactive substances and antioxidant assay kits, respectively, and lumiaggregometry was used for measurement of reactive oxygen species (ROS) and aggregation.

    RESULTS: Porphyromonas gingivalis exerted substantial proteolytic effects on the lipoproteins. The Rgp gingipains were responsible for producing 2 apoE fragments, as well as 2 apoB-100 fragments, in LDL, and the Kgp gingipain produced an unidentified fragment in high-density lipoproteins. Porphyromonas gingivalis and its different gingipain variants induced ROS and consumed antioxidants. Both the Rgp and Kgp gingipains were involved in inducing lipid peroxidation.

    CONCLUSIONS: Porphyromonas gingivalis has the potential to change the expression of lipoproteins in blood, which may represent a crucial link between periodontitis and CVD.

  • 24.
    Månsson, Emeli
    et al.
    Örebro University, School of Medical Sciences. Centre for Clinical Research, Hospital of Västmanland, Region Västmanland, Västerås,Sweden; Centre for Clinical Research, Hospital of Västmanland, Uppsala University, Västerås, Sweden.
    Söderquist, Bo
    Örebro University, School of Medical Sciences. Department of Laboratory Medicine, Clinical Microbiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Nilsdotter-Augustinsson, Åsa
    Department of Infectious Diseases, Department of Clinical and Experimental Medicine, Linköping University, Norrköping, Sweden.
    Särndahl, Eva
    Örebro University, School of Medical Sciences.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Staphylococcus epidermidis from prosthetic joint infections induces lower IL-1 release from human neutrophils than isolates from normal flora2018In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 126, no 8, p. 678-684Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to test the hypothesis that Staphylococcus epidermidis isolated from prosthetic joint infections (PJIs) differs from S.epidermidis isolated from normal flora in terms of its capacity to induce activation of caspase-1 and release of IL-1 in human neutrophils. The amount of active caspase-1 was determined over 6h by detecting Ac-YVAD-AMC fluorescence in human neutrophils incubated with S.epidermidis isolates from PJIs (ST2) or normal flora. The amount of IL-1 was detected by ELISA in neutrophil supernatants after 6h of incubation. Mean IL-1 release was lower after incubation with S.epidermidis from PJIs compared to isolates from normal flora, but no statistically significant difference was found in active caspase-1. Substantial inter-individual differences in both active caspase-1 and IL-1 were noted. These results suggest that evasion of innate immune response, measured as reduced capacity to induce release of IL-1 from human neutrophils, might be involved in the predominance of ST2 in S.epidermidis PJIs, but that other microbe-related factors are probably also important.

  • 25.
    Palm, Eleonor
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Demirel, Isak
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Bengtsson, Torbjörn
    Örebro University, School of Medicine, Örebro University, Sweden.
    Khalaf, Hazem
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    The role of toll-like and protease-activated receptors and associated intracellular signalling in Porphyromonas gingivalis-infected gingival fibroblastsManuscript (preprint) (Other academic)
  • 26.
    Palm, Eleonor
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Demirel, Isak
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Bengtsson, Torbjörn
    Örebro University, School of Medicine, Örebro University, Sweden.
    Khalaf, Hazem
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    The role of toll-like and protease-activated receptors in the expression of cytokines by gingival fibroblasts stimulated with the periodontal pathogen Porphyromonas gingivalisManuscript (preprint) (Other academic)
  • 27.
    Palm, Eleonor
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Biomedicine, Örebro University Hospital, Örebro, Sweden.
    Demirel, Isak
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Biomedicine, Örebro University Hospital, Örebro, Sweden.
    Bengtsson, Torbjörn
    Örebro University, School of Medicine, Örebro University, Sweden. Department of Biomedicine, Örebro University Hospital, Örebro, Sweden.
    Khalaf, Hazem
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Biomedicine, Örebro University Hospital, Örebro, Sweden.
    The role of toll-like and protease-activated receptors in the expression of cytokines by gingival fibroblasts stimulated with the periodontal pathogen Porphyromonas gingivalis2015In: Cytokine, ISSN 1043-4666, E-ISSN 1096-0023, Vol. 76, no 2, p. 424-432Article in journal (Refereed)
    Abstract [en]

    Porphyromonas gingivalis is a periodontitis-associated pathogen and interactions between the bacterium and gingival fibroblasts play an important role in development and progression of periodontitis, an inflammatory disease leading to degeneration of tooth-supporting structures. Gingival fibroblasts, which expresses protease activated receptors (PARs) as well as toll-like receptors (TLRs), produces inflammatory mediators upon bacterial challenges. In this study, we elucidated the importance of PAR1, PAR2, TLR2 and TLR4 for the expression and secretion of CXCL8, interleukin-6 (IL-6), transforming growth factor-beta 1 (TGF-beta 1) and secretory leukocyte inhibitor (SLPI). Human gingival fibroblasts were transfected with small-interfering RNA against the target genes, and then stimulated with P. gingivalis wild-type W50 and W50-derived double rgp mutant E8 and kgp mutant K1A. TLR2-silencing reduced P. gingivalis-induced CXCL8 and IL-6. IL-6 was also reduced after PAR1-silencing. No effects were observed for TGF-beta 1. SLPI was suppressed by P. gingivalis and silencing of PAR1 as well as TLR2, gave additional suppression at the mRNA level. TLR4 was not involved in the regulation of the investigated mediators. CXCL8 and IL-6 are important for progression and development of periodontitis, leading to a chronic inflammation that may contribute to the tissue destruction that follows an exacerbated host response. Therefore, regulating the expression of TLR2 and subsequent release of CXCL8 and IL-6 in periodontitis could attenuate the tissue destruction seen in periodontitis.

  • 28.
    Svensson, Lovisa
    et al.
    Örebro University, School of Medical Sciences.
    Poljakovic, Mirjana
    Integrated Cardio Metabolic Centre, Department of Medicine, Karolinska University Hospital, Stockholm, Sweden.
    Demirel, Isak
    Örebro University, School of Medical Sciences.
    Sahlberg, Charlotte
    Örebro University, School of Health Sciences.
    Persson, Katarina
    Örebro University, School of Medical Sciences.
    Host-Derived Nitric Oxide and Its Antibacterial Effects in the Urinary Tract2018In: Advances in Microbial Physiology, ISSN 0065-2911, E-ISSN 2162-5468, Vol. 73, p. 1-62Article, review/survey (Refereed)
    Abstract [en]

    Urinary tract infection (UTI) is one of the most common bacterial infections in humans, and the majority are caused by uropathogenic Escherichia coli (UPEC). The rising antibiotic resistance among UPEC and the frequent failure of antibiotics to effectively treat recurrent UTI and catheter-associated UTI motivate research on alternative ways of managing UTI. Abundant evidence indicates that the toxic radical nitric oxide (NO), formed by activation of the inducible nitric oxide synthase, plays an important role in host defence to bacterial infections, including UTI. The major source of NO production during UTI is from inflammatory cells, especially neutrophils, and from the uroepithelial cells that are known to orchestrate the innate immune response during UTI. NO and reactive nitrogen species have a wide range of antibacterial targets, including DNA, heme proteins, iron-sulfur clusters, and protein thiol groups. However, UPEC have acquired a variety of defence mechanisms for protection against NO, such as the NO-detoxifying enzyme flavohemoglobin and the NO-tolerant cytochrome bd-I respiratory oxidase. The cytotoxicity of NO-derived intermediates is nonspecific and may be detrimental to host cells, and a balanced NO production is crucial to maintain the tissue integrity of the urinary tract. In this review, we will give an overview of how NO production from host cells in the urinary tract is activated and regulated, the effect of NO on UPEC growth and colonization, and the ability of UPEC to protect themselves against NO. We also discuss the attempts that have been made to develop NO-based therapeutics for UTI treatment.

1 - 28 of 28
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf