DAla2GIP antagonizes H₂O₂-induced chondrocyte apoptosis and inflammatory factor secretion

To investigate the protective effects of DAla2GIP against the apoptosis and inflammatory factor secretion in H₂O₂-induced chondrocyte, and explore the possible mechanisms of DAla2GIP underlying its protection.

The chondrocytes were divided into the following four groups: Control, 300 μM H₂O₂, 100 pM DAla2GIP and 300 μM H₂O₂ + 100 pM DAla2GIP. The apoptosis of chondrocyte was measured by using mitochondrial membrane potential assay kit (JC-1) and TUNEL assay, the inflammatory factor secretion were assessed by ELISA assay, and the cellular and molecular mechanisms of DAla2GIP protection were investigated by using Real time-PCR, flow cytometry, Non- invasive calcium detection and western blotting techniques.

(1) DAPla2GIP prevents apoptosis of chondrocyte induced by H₂O₂. (2) DAla2GIP alleviated the inflammation of chondrocyte induced by H₂O₂. (3) DAla2GIP prevents chondrocyte apoptosis by inhibiting calcium influx of chondrocyte and regulating expression of Bcl-2 and Caspase-3induced by H₂O₂. (4) DAla2GIP inhibited the H₂O₂ mediated inflammation by up- regulating the expressions of Sox9 and Col2a1 and inhibiting PI3K/Akt/NF-κB pathway.

Our experimental results revealed that DAla2GIP prevents chondrocyte apoptosis by inhibiting calcium influx of chondrocyte and induced regulating expression of Bcl-2 and Casp ase-3by H₂O₂. Further, molecular biology experiments confirmed that DAla2GIP inhibited the H₂O₂ mediated inflammation vis up-regulating the expressions of Sox9 and Col2a1 and inhibiting PI3K/Akt/NF-κB pathway. The results demonstrate that DAla2GIP has protective properties in H₂O₂-induced chondrocyte injury, this finding shows that novel GIP analogues have the potential as a novel therapeutic for osteoarthritis patients.