Effect of growth hormone releasing hormone on chondrocytes of osteoarthritis

BACKGROUND/AIMS: To evaluate the effect and possible mechanism of growth hormone releasing hormone (GHRH) on chondrocytes of osteoarthritis (OA). METHODS: Articular chondrocytes were cultured and the expression of GHRH receptor in chondrocytes was detected. Then recombinant adenovirus GHRH (Ad-GHRH) was transfected to one group of chondrocytes. The expression of collagen type II, matrix metalloproteinase 13 (MMP-13) and signal transducer and activator of transcription 3 (STAT3) in each experimental group was determined by Western blot. RESULTS: The GHRH receptor was expressed in chondrocytes, and this provided a basis for further study of the role of GHRH in chondrocytes. Cell proliferation of the Ad-GHRH group was significantly higher than that of the OA group by CCK-8 assay. Compared with the OA-group, the protein expression of MMP‑13 was decreased in the Ad-GHRH group. Compared with the OA-group, the protein expression of collagen type II, phosphorylated STAT3 (P-STAT3) were increased in the Ad-GHRH group. CONCLUSIONS: Our results show that the GHRH receptor is expressed in chondrocytes. GHRH can promote the proliferation of chondrocytes and the synthesis of type II collagen, and increase the extracellular matrix, which is achieved by phosphorylated STAT3 protein.