CTGF Positively Regulates BMP12 Induced Tenogenic Differentiation of Tendon Stem Cells and Signaling

Abstract

Background/Aims: Disordered differentiation of tendon stem cells (TSCs) during repair of injured tendon can result in the pathogenesis of chronic tendinopathy. Understanding tenocyte differentiation may provide new therapeutic insights for the prevention and treatment of chronic tendinopathy. The aim of our study was to determine if CTGF exerts a similar effect on BMP12-driven differentiation of rat TSCs. Methods: In overexpressing and RNA interference CTGF TSCs, tenogenic differentitation and the expression of related genes were determined by immunofluorescence staining, quantitative PCR, and western blotting, with or without BMP12 treatment. The interaction in vitro between CTGF and BMP12 was detected by Chemical crosslinking assay. Results: Our results showed that BMP12 effectively increased the expression of the tenocyte lineage markers scleraxis (Scx) and tenomodulin (Tnmd) at both mRNA and protein levels. Over-expression of CTGF from a lentiviral vector increased the expression of Scx and Tnmd as well as tendon proteins type I collagen (ColI) and tenascin-C (Tn-C) in TSCs compared to non-treated control cells with or without simultaneous BMP12 stimulation. Knockdown of CTGF expression decreased the expression of Scx, Tnmd, ColI and Tn-C compared to control cells. Chemical crosslinking experiments demonstrated a direct interaction between CTGF and BMP12. Conclusion: In conclusion, BMP12 plays a crucial role in tenogenesis via the Smad1/5/8 pathway, and CTGF positively promotes this effect.

Harnessing endogenous stem/progenitor cells for tendon regeneration

“…In addition, transplantation of CD146 + TSCs treated by CTGF short-term was able to induce tendon regeneration (Supplemental Figure 11, C and F), whereas scar-like tissue with disrupted collagens formed when CD146 -or untreated CD146 + tendon cells were delivered (Supplemental Figure 11, A The TGF-β pathway has been reported to play critical roles in tendon development (50). A recent in vitro study suggested a potential link between CTGF and BMP12 in tenogenic differentiation of rat flexor TSCs (51). Although we have demonstrated that the FAK/ERK1/2 pathway regulates CTGF's function in CD146 + TSCs using siRNA KD, it is unclear how CTGF-regulated tenogenic differentiation is linked with signaling mediated by TGF-β and/or BMPs.…”

“…Osteogenic, chondrogenic, and adipogenic differentiation were induced by applying differentiation media, as per our prior methods (6,37,38). Osteogenic differentiation medium contained 100 nM dexamethasone, 10 mM β-glycerophosphate, and 0.05 mM l-ascorbic acid 2-phosphate (SigmaAldrich) per our prior methods (12,51). Chondrogenic medium was supplemented with 10 ng/ml transforming growth factor-β3 (TGF-β3) (R&D Systems).…”

Thermal Preconditioning May Prevent Tendon Adhesion by Up-Regulating HSP72 in Rats

“…Tendon stem cells (TSCs), prone to osteogenic differentiation under excessive tension, present a high multi-differentiation potential, self-renewal capacity, and low immunogenicity [18, 19], and disordered differentiation of TSCs in the repair of injured tendon might lead to the pathogenesis of chronic tendinopathy [20]. The metaplasia of adipose tissue appeared in the ruptured tendon demonstrates that Dex could induce TSCs to differentiate into adipocytes, while the mechanism of it remains unclear [21].…”

Tendon stem progenitor cells: Understanding the biology to inform therapeutic strategies for tendon repair

“…BMP14 also increased cell proliferation in a time and dose‐dependent manner as well as matrix content . Similarly, BMP12 (GDF7) resulted in upregulation of several tendon markers, including Scx , Tnmd , Col1a1 , and Tnc . Although combinatorial screens with these BMPs have not been extensively studied for TSPCs, stimulation with BMP12 in combination with overexpression of CTGF had an additive effect on the expression of tendon genes .…”