Inhibition of interleukin 1-induced matrix metalloproteinase 13 expression in human chondrocytes by interferon  

Abstract

Background: Despite well-documented immunomodulation by interferon c (IFNc), its role and mechanism of regulation of matrix metalloproteinase 13 (MMP13) gene expression in human chondrocytes is unknown. Objective: To investigate the ability and mechanism of IFNc to suppress interleukin 1 (IL1)-induced MMP13 expression in articular chondrocytes. Methods: Human chondrocytes were treated with IFNc or IL1b alone or in combination. MMP13 mRNA was analysed by semiquantitative reverse transcriptase-PCR. MMP13 protein, phospho-signal transducer and activator of transcription 1 (STAT1) and p44/42 mitogen-activated protein kinase levels were measured by western blotting. MMP13 promoter luciferase, cytomegalovirus cyclic AMP response element-binding protein (CBP)/p300 plasmids and STAT1 small interfering RNA (siRNA) were transfected by the calcium phosphate method. IFNc receptor was also neutralised. Activator protein (AP) 1 activity was monitored by the TransAM transcription factor kit. STAT1-CBP/p300 interaction was studied by immunoprecipitation. Results: IFNc potently suppressed IL1-induced expression of MMP13 and promoter activity. Blockade with neutralising IFNc R1 antibody revealed that MMP13 inhibition by IFNc is mediated by the IFN receptor. IFNcstimulated activation of STAT1 was directly correlated with MMP13 suppression. Knockdown of the STAT1 gene by specific siRNA or its inhibition with fludarabine partially restored the IL1b induction of MMP13 expression and promoter activity. IFNc did not alter AP1 binding ability but promoted physical interaction of STAT1 and CBP/p300 coactivator. p300 overexpression reversed IFNc inhibition of endogenous MMP13 mRNA expression and exogenous MMP13 promoter activity. Conclusion: IFNc, through its receptor, activates STAT1, which binds with CBP/p300 coactivator, sequesters it from the cell system, and thus inhibits transcriptional induction of the MMP13 gene in chondrocytes. IFNc and its signalling pathways could be targeted therapeutically for diminishing IL1-induced cartilage degradation by MMP13 in patients with arthritis.

Uhrf1 is indispensable for normal limb growth by regulating chondrocyte differentiation through specific gene expression

“…In this study, integrative analyses using MBD-seq and RNA-seq could identify direct and specific target genes of Uhrf1 in chondrocytes, such as Hspb1. Hspb1 is a downstream factor in IL1 signaling and can increase Mmp13 expression as well as induce articular cartilage degeneration (Ahmad et al, 2007;Freshney et al, 1994). Although there are differences between articular and growth plate chondrocytes, these reports help to elucidate Uhrf1 and Hspb1 functions in chondrocyte differentiation.…”

“…5E and Fig. S6A), because they are known to be related to IL1 signaling (Freshney et al, 1994;Hsu et al, 1995), which can facilitate Mmp13 expression and cartilage degradation (Ahmad et al, 2007). Hspb1 expression was increased in the growth plate as well as in the primary spongiosa of cKO mice, as shown by IHC ( Fig.…”

CXCL10 suppression of hem- and lymph-angiogenesis in inflamed corneas through MMP13

“…MMP-13 is thought to be the major enzyme responsible for cartilage collagen degradation, which is driven by IL-1 cytokine. The IL-1 signaling, however, suppressed by interferon-γ, resulting in downregulation of MMP-13 [54, 55]. Our previous study revealed that basal epithelium expressed CXCL10 recruits NK cells to line underneath the basement membrane of the epithelium and infection results in the influx of NK cells that express IFN-γ which in turn induces the persistent expression of CXCL10 during infection.…”

Defining the roles of inflammatory and anabolic cytokines in cartilage metabolism

“…MMP gene expression may also be modified by JAK/STAT signalling, although direct binding to STAT sites in MMP promoters has not been demonstrated. Oncostatin M augments IL1-induced expression of several MMPs and ADAMTSs by activating Stat3,116 – 118 whereas interferon γ antagonises cytokine induction of MMP-1, 9 and 13 through mechanisms that involve interaction of Stat1α with AP-1 or CBP/p300 119…”