Interleukin-1β induces differentiation of human mesenchymal stem cells into osteoblasts via the Wnt-5a/receptor tyrosine kinase-like orphan receptor 2 pathway.

Mesenchymal stem cells (MSCs) are considered to be a novel tool for the treatment of rheumatoid arthritis (RA) because of their multipotency to differentiate into osteoblasts and chondrocytes, their immunosuppressive effects, and availability. The aim of this study was to assess the mechanisms of human MSC differentiation into osteoblasts under inflammatory conditions. Human MSCs were cultured in commercialized osteogenic induction medium with inflammatory cytokines for up to 10 days. Osteoblast differentiation was detected by alkaline phosphatase staining and messenger RNA (mRNA) expression of multiple osteoblast markers. Mineralization was assessed by alizarin red S staining. Among the various cytokines tested, interleukin-1β (IL-1β) induced differentiation of human MSCs into osteoblasts, which was confirmed by alkaline phosphatase activity, expression of RUNX2 mRNA, and strong alizarin red S staining. Among various molecules of the Wnt family, Wnt-5a and receptor tyrosine kinase-like orphan receptor 2 (Ror2), a major receptor of Wnt-5a, were significantly induced in human MSCs by IL-1β. Silencing of either WNT5A or ROR2 by small interfering RNA with 2 different sequences reduced alkaline phosphatase activity, RUNX2 expression, and alizarin red S staining of human MSCs induced by IL-1β. IL-1β effectively and rapidly induced human MSC differentiation into osteoblasts and mineralization, mainly through the noncanonical Wnt-5a/Ror2 pathway. These results suggest potential benefits of IL-1β-treated human MSCs in the treatment of damaged bone as well as in the induction of self-renewal and self-repair of damaged tissue, including osseous tissue.

Sonomoto K ，Yamaoka K ，Oshita K ，Fukuyo S ，Zhang X ，Nakano K ，Okada Y ，Tanaka Y ... -  《-》

IL-6-accelerated calcification by induction of ROR2 in human adipose tissue-derived mesenchymal stem cells is STAT3 dependent.

The mechanisms of ectopic calcification in inflammatory diseases are poorly understood. We investigated the effects of inflammatory cytokines on the mechanisms of calcification in human adipose tissue-derived mesenchymal stem cells (hADSCs). The effects of inflammatory cytokines were evaluated using hADSCs cultured in osteoblast induction medium. mRNA expression was measured by real-time PCR and protein levels were measured by western blotting. Cell mineralization was evaluated by Alizarin Red S staining. In hADSCs, administration of IL-6/soluble IL-6 receptor (sIL-6R), TNF or IL-1β accelerated calcification through enhanced expression of an osteoblast differentiation marker, runt-related transcription factor 2 (RUNX2). IL-6/sIL-6R had the greatest effect. The transcription of mRNA for receptor tyrosine kinase-like orphan receptor 2 (ROR2), involved in the non-canonical wingless-type (WNT) MMTV integration site pathway, was increased, while β-catenin expression, an essential factor in the canonical WNT signalling pathway for osteoblast differentiation, did not change. Suppression of signal transducer and activator of transcription 3 (STAT3), but not STAT1, by small interfering RNA (siRNA) exerted a strong inhibitory effect on RUNX2 and ROR2 expression, and inhibited accelerated calcification. IL-6/sIL-6R stimulation accelerated the ROR2/WNT5A pathway in hADSCs in a STAT3-dependent manner, resulting in augmented calcification. These results suggest that the mechanisms of ectopic calcification accelerated by IL-6 in hADSCs may be involved in chronic inflammatory tissues and that IL-6 inhibitors may be beneficial in the treatment of ectopic calcification in inflammatory diseases.

Fukuyo S ，Yamaoka K ，Sonomoto K ，Oshita K ，Okada Y ，Saito K ，Yoshida Y ，Kanazawa T ，Minami Y ，Tanaka Y ... -  《-》

The Wnt5a/Ror2 pathway is associated with determination of the differentiation fate of bone marrow mesenchymal stem cells in vascular calcification.

Xin H ，Xin F ，Zhou S ，Guan S ... -  《-》

Myeloma cells inhibit non-canonical wnt co-receptor ror2 expression in human bone marrow osteoprogenitor cells: effect of wnt5a/ror2 pathway activation on the osteogenic differentiation impairment induced by myeloma cells.

Bolzoni M ，Donofrio G ，Storti P ，Guasco D ，Toscani D ，Lazzaretti M ，Bonomini S ，Agnelli L ，Capocefalo A ，Dalla Palma B ，Neri A ，Nicolini F ，Lisignoli G ，Russo F ，Colla S ，Aversa F ，Giuliani N ... -  《-》

Wnt5a is associated with the differentiation of bone marrow mesenchymal stem cells in vascular calcification by connecting with different receptors.

Guan S ，Wang Z ，Xin F ，Xin H ... -  《-》