Effects on the function of growth plate chondrocytes by A-kinase anchoring protein 2 gene expression

English Keywords:A-kinase anchoring protein 2  Chondrocytes  Proliferation  Differentiation  ERK1/2 signal path?鄄way

English Abstract:

  【Abstract】 Objectives: To investigate the effect and mechanism of A-kinase anchoring protein 2 (AKAP2) gene expression on the proliferation, differentiation and extracellular matrix metabolism of growth plate chon?鄄drocytes(GPCs). Methods: Designing AKAP2 overexpression and knockdown plasmids to transfect GPCs for overexpression or interference with AKAP2. The negative control of overexpression group(Vector group), the AKAP2 overexpression group (AKAP2 OE group), the negative control of interference group(si-NC group), the AKAP2 interference group(si-AKAP2 group) and AKAP2 OE+U0126 group[U0126: a blocker of the extracellu?鄄lar signal regulated kinase 1/2(ERK1/2) pathway] were constructed. GPCs cell proliferation and calcium depo?鄄sition were recorded. The expression of collagen type Ⅱ alpha 1 (COL2A1), alkaline phosphatase (ALP), col?鄄lagen type Ⅱ(COLⅡ), proliferating cell nuclear antigen(PCNA), SRY-related high-mobility group box gene 9(SOX9) and ERK1/2, phosphorylation level of phosphorylated ERK1/2(p-ERK1/2) were tested. The data were statistically analyzed. Results: Compared with the Vector group, the gene expression of AKAP2, ALP, and COL2A1, and the protein expression level of AKAP2, PCNA, SOX9, ALP, COLⅡ, p-ERK1/2, and cell via?鄄bility were significantly higher, and calcium nodules significantly increased in the AKAP2 OE group (P<0.05). Compared with the si-NC group, the si-AKAP2 group showed the opposite downtrend. Compared with the AKAP2 OE group, the expression of ALP, COLⅡA1, the protein expression level of PCNA, SOX9, ALP, and COLⅡ, p-ERK1/2, cell viability, and protein deposition of COLⅡ were significantly lower, and significantly decreased in the AKAP2 OE+U0126 group (P<0.05). No difference was found in the expression of ERK1/2 (P>0.05). Conclusions: AKAP2 could affect the proliferation, differentiation and extracellular matrix metabolism of chondrocytes through the ERK1/2 signaling pathway, and it may further change the normal growth plate endochondral bone formation pattern.