Elevated concentrations of IL-6 (interleukin-6) and sIL-6r (soluble IL-6 receptor) in the synovial fluid and serum of patients with arthritis have been implicated in joint cartilage destruction. This study examined the effects of IL-6 and sIL-6r on the expression of MMPs (matrix metalloproteinases), TIMPs (tissue inhibitor of metalloproteinases), the plasminogen activation system including tPA (tissue-type PA), uPA (urokinase-type PA) and PAI-1 (PA inhibitor type 1) using chondrocytes derived from normal human femur cartilage. The cells were cultured with or without 50 ng/ml IL-6 and/or 30 ng/ml sIL-6r in the presence or absence of the JAK3 (Janus kinase 3) inhibitor WHI-P131 or the MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular signal protein kinase) kinase] inhibitor PD98059 for up to 28 days. The expression of MMPs, TIMPs, uPA, tPA and PAI-1 was investigated at the mRNA and protein levels. MMP protein expression and pSTAT3 (phosphorylation of signal transducer and activator of transcription 3) and pERK (phosphorylation of ERK) were also measured. Treatment with both IL-6 and sIL-6r markedly increased the expression of MMP-1, MMP-13, TIMP-1 and PAI-1, while significantly decreasing the expression of tPA and uPA and stimulating pSTAT3 and pERK. Adding WHI-P131 or PD98059 decreased IL-6 and sIL-6r enhancement of MMP-1, -3 and -13. The results suggest that IL-6 and sIL-6r stimulate the production of MMPs and their inhibitor via JAK-STAT and ERK-MAPK signalling in chondrocytes.
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http://dx.doi.org/10.1042/CBI20110150 | DOI Listing |
Front Immunol
January 2025
Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
Introduction: Serum levels of interleukin-6 (IL-6) are increased in COVID-19 patients. IL-6 is an effective therapeutic target in inflammatory diseases and tocilizumab, a monoclonal antibody that blocks signaling via the IL-6 receptor (IL-6R), is used to treat patients with severe COVID-19. However, the IL-6R exists in membrane-bound and soluble forms (sIL-6R), and the sIL-6R in combination with soluble glycoprotein 130 (sgp130) forms an IL-6-neutralizing buffer system capable of neutralizing small amounts of IL-6.
View Article and Find Full Text PDFJ Infect Dis
January 2025
Peking University People's Hospital, Peking University Institute of Hematology, National Clinical Research Center for Treatment of Hematological Disease, Beijing Key Laboratory of Hematopoietic Stem Cell Transplantation for the Treatment of Hematological Diseases, Beijing, China.
Background: Severe pneumonia after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is associated with high mortality. Given that cytokine, including Interleukin-6 (IL-6), play a critical role in immune-mediated organ injury in patients with severe COVID-19, we hypothesized that cytokines may also contribute to the pathogenesis of severe pneumonia after allo-HSCT. This study aimed to investigate the role of IL-6 in severe pneumonia post-allo-HSCT and explore its underlying mechanism.
View Article and Find Full Text PDFAnticancer Res
January 2025
Department of Charged Particle Therapy Research, National Institutes for Quantum Science and Technology, Chiba, Japan
Background/aim: For patients with unresectable locally advanced pancreatic cancer (LAPC), carbon-ion radiotherapy (C-ion RT) can safely deliver higher doses than conventional photon therapy, increasing the potential for long-term survival. However, achieving meaningful improvements in survival rates requires reliable prognostic biomarkers to identify patients likely to benefit from treatment.
Patients And Methods: In this study, we measured plasma levels of soluble interleukin-6 receptor (sIL-6R) before C-ion RT and examined their association with the risk of distant metastasis (DM), local recurrence (LR), and overall survival (OS).
Exp Eye Res
December 2024
Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
Intraocular pressure (IOP) is regulated through the balance of production and drainage of aqueous humor. The main route of aqueous-humor outflow comprises the trabecular meshwork (TM) and Schlemm's canal (SC). We reported that IL-6 trans-signaling can inhibit TGF-β signaling in TM cells and may affect regulation of IOP.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
December 2024
Center for Biotechnology & Genomic Medicine, Augusta University, Augusta, Georgia, United States.
Purpose: Interleukin-6 (IL-6) is an inflammatory cytokine implicated in various retinal pathologies and functions primarily through two signaling pathways: cis-signaling via IL-6 binding to its membrane-bound receptor (IL-6Rα), and trans-signaling via IL-6 binding to soluble IL-6 receptor (sIL-6R). Because the differential effects of IL-6 signaling in retinal Müller glial cells (MGCs) remain unclear, we generated an MGC-specific Il6ra-/- knockout (KO) mouse to eliminate IL-6Rα and, consequently, IL-6 cis-signaling in MGCs. In this study, we examined the proteomic changes in MGCs isolated from KO mice lacking a functional IL-6Rα.
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