Proteomic Analysis Reveals Grb2 as a Key Regulator of Periodic Mechanical Stress Transduction in Chondrocytes

Abstract

Background/Aims: Periodic mechanical stress could significantly promote chondrocyte proliferation and matrix synthesis. However, the mechanisms underlying the ability of chondrocyte detecting and responding to periodic mechanical stimuli have not been well delineated. Methods: Quantitative proteomic analysis was performed to construct the differently expressed proteome profiles of chondrocyte under pressure. Then a combination of Western blot, quantitative real-time PCR, lentiviral vector and histological methods were used to confirm the proteomic results and investigate the mechanoseing mechanism. Results: Growth factor receptor-bound protein 2 (Grb2), a component of integrin adhesome, was found a 1.49-fold increase in dynamic stress group. This process was mediated through integrin β1, leading to increased phosphorylation of focal adhesion kinase (FAK) and extracellular signal–regulated kinase 1/2 (ERK1/2) respectively and then produce the corresponding biological effects. Conclusion: This was the first time to demonstrate Grb2 has such an important role in periodic mechanotransduction, and the proteomic data could facilitate the further investigation of chondrocytes mechanosensing.

Periodic Mechanical Stress Stimulates Cav-1-Dependent IGF-1R Mitogenic Signals in Rat Chondrocytes Through ERK1/2

“…The cells were trypsinized and counted as previously described [24]. The cell number was determined by counting each piece of glass slide independently.…”