Background: Protease-Activated Receptors (PARs), members of G-protein-coupled receptors, are activated by proteolytic activity of various proteases. Activation of PAR1 and PAR2 triggers innate immune responses in human oral keratinocytes (HOKs), but the signaling pathways downstream of PAR activation in HOKs have not been clearly defined. In this study, we aimed to determine if PAR1- and PAR2-mediated signaling differs in the induction of innate immune markers CXCL3, CXCL5 and CCL20 via ERK, p38 and PI3K/Akt.
Results: Our data show the induction of innate immunity by PAR1 requires both p38 and ERK MAP kinases, while PAR2 prominently signals via p38. However, inhibition of PI3K enhances expression of innate immune markers predominantly via suppressing p38 phosphorylation signaled by PAR activation.
Conclusion: Our data indicate that proteases mediating PAR1 and PAR2 activation differentially signal via MAP kinase cascades. In addition, the production of chemokines induced by PAR1 and PAR2 is suppressed by PI3K/Akt, thus keeping the innate immune responses of HOK in balance. The results of our study provide a novel insight into signaling pathways involved in PAR activation.
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http://dx.doi.org/10.1186/1471-2172-11-53 | DOI Listing |
Elife
December 2024
Department of Cadre Cardiology, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China.
Metabolic abnormalities associated with liver disease have a significant impact on the risk and prognosis of cholecystitis. However, the underlying mechanism remains to be elucidated. Here, we investigated this issue using Wilson's disease (WD) as a model, which is a genetic disorder characterized by impaired mitochondrial function and copper metabolism.
View Article and Find Full Text PDFPLoS Pathog
January 2025
Institute of Pediatric Infection, Immunity, and Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Function-to-find domain (FIIND)-containing proteins, including NLRP1 and CARD8, are vital components of the inflammasome signaling pathway, critical for the innate immune response. These proteins exist in various forms due to autoproteolysis within the FIIND domain, resulting in full-length (FL), cleaved N-terminal (NT), and cleaved C-terminal (CT) peptides, which form autoinhibitory complexes in the steady state. However, the detailed mechanism remains elusive.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22908.
Although viruses subvert innate immune pathways for their replication, there is evidence they can also co-opt antiviral responses for their benefit. The ubiquitous human pathogen, Herpes simplex virus-1 (HSV-1), encodes a protein (UL12.5) that induces the release of mitochondrial nucleic acid into the cytosol, which activates immune-sensing pathways and reduces productive replication in nonneuronal cells.
View Article and Find Full Text PDFAnnu Rev Pathol
January 2025
Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA; email:
Focal segmental glomerulosclerosis (FSGS) is the morphologic manifestation of a spectrum of kidney diseases that primarily impact podocytes, cells that create the filtration barrier of the glomerulus. As its name implies, only parts of the kidney and glomeruli are affected, and only a portion of the affected glomerulus may be sclerosed. Although the diagnosis is based primarily on microscopic features, patient stratification relies on clinical data such as proteinuria and etiological criteria.
View Article and Find Full Text PDFJ Infect Dis
January 2025
School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
Background: Inflammation and innate immune activation are associated with chronic HIV infection, despite effective treatment. Although gut microbiota alterations are linked to systemic inflammation, the relationships between the gut microbiome, inflammation and HIV remain unclear.
Methods: The UPBEAT-CAD sub-study, examining cardiovascular disease (CVD) risk in HIV, enrolled participants matched on HIV status and traditional CVD risk factors.
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