GDF15 enhances proliferation of aged chondrocytes by phosphorylating SMAD2

• Published in: Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2022-01, Vol.27 (1), p.249-256
• Main Authors: Wang, Dongming, Wei, Xiaochun, Geng, Xiang, Li, Pengcui, Li, Lu
• Format: Article
• Language: English
• Subjects: Aged; Cell Proliferation; Chondrocytes - metabolism; Gene Expression; Growth Differentiation Factor 15; Humans; Osteoarthritis; Smad2 Protein; Transforming Growth Factor beta - metabolism
• ISSN: 0949-2658; 1436-2023
• DOI: 10.1016/j.jos.2020.12.004

Aging is one of the primary factors influencing development of osteoarthritis, and the TGF-β pathway plays an important role in age-related osteoarthritis. Specifically, GDF15 phosphorylates SMAD2/3 in the TGF-β pathway to inhibit cardiomyocyte hypertrophy, and promote proliferation of chondrocytes. However, age-dependent changes in the level of GDF15 are unclear, as is whether GDF15 phosphorylates SMAD2/3 in the TGF-β pathway to promote proliferation of old chondrocytes. This study, therefore, sought to examine the effect of various GDF15 concentrations on old chondrocyte proliferation. Serum and cartilage specimens of young adults and older adults were collected, and GDF15 expression was quantified. Human chondrocytes were then cultured following routine protocols, and different concentrations of recombinant human GDF15 or pSMAD2 inhibitor were added into the culture medium. After 48 h of culturing, the proliferation of chondrocytes was detected by EdU, and the expression MMP13, SMAD2, and pSMAD2 was detected in chondrocytes via western blot and qRT-PCR analysis. The GDF15 content in serum and cartilage of young adults was higher than that of older adults (p