Interleukin-1α induces focal degradation of biglycan and tissue degeneration in an in-vitro ovine meniscal model

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• 作者：Emily Fuller^a ; Christopher B. Little^a ; ^b ; James Melrose^a ; ^b ; ^c ; ^{james.melrose@sydney.edu.au" class="auth_mail" title="E-mail the corresponding author}
• 关键词：MI ; MO ; LI ; LO ; the inner and outer zones of the medial and lateral menisci ; AC ; articular cartilage ; IL-1 ; interleukin-1 ; IVD ; intervertebral disc ; GuHCl ; guanidine hydrochloride ; ADAMTS ; a disintegrin adamalysin protease with thrombospondin type 1 motifs ; MMP ; matrix metalloproteinase ; SLRPs ; small leucine rich proteoglycans
• 刊名：Experimental and Molecular Pathology
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：101
• 期：2
• 页码：214-220
• 全文大小：847 K

文摘

We have developed an ovine meniscal explant model where the focal degradative events leading to characteristic fragmentation patterns of biglycan in human OA of the knee and hip, and evident in animal models of knee OA and IVD degeneration are reproduced in culture. Lateral and medial menisci were dissected into outer, mid and inner zones and established in explant culture ± IL-1 (10 ng/ml). The biglycan species present in conditioned media samples and in GuHCl extracts of tissues were examined by Western blotting using two C-terminal antibodies PR-85 and EF-Bgn. Clear differences were evident in the biglycan species in each meniscal tissue zone with the medial outer meniscus having lower biglycan levels and major fragments of 20, 28, 33 and 36, 39 kDa. Similar fragmentation was detected in articular cartilage samples, 42-45 kDa core protein species were also detected. Biglycan fragmentation was not as extensive in the IL-1 stimulated meniscal cultures with 36, 39, 42 and 45 kDa biglycan species evident. Thus the medial meniscus outer zone displayed the highest levels of biglycan processing in this model and correlated with a major zone of meniscal remodelling in OA in man. Significantly, enzymatic digests of meniscal tissues with MMP-13, ADAMTS-4 and ADAMTS-5 have also generated similar biglycan species in-vitro. Zymography confirmed that the medial outer zone was the region of maximal MMP activity. This model represents a convenient system to recapitulate matrix remodelling events driven by IL-1 in pathological cartilages and in animal models of joint degeneration.