Impact of estrogen-related receptor α on the biological characteristics of rat mandibular condylar chondrocytes.

It is well‑known that estrogen-related receptor α (ERRα) affects numerous metabolic pathways and biological functions in the body, although the function of ERRα in the mandibular condylar chondrocytes (MCCs) of the temporomandibular joint remains unclear. The aim of the present study was to investigate the effect of ERRα on the biological characteristics of MCCs in female rats. Immunofluorescent staining was used to observe the expression level and distribution of ERRα in MCCs and tissues. Quantitative polymerase chain reaction (qPCR) was performed to detect the impact of estrogen intervention on the biological characteristics of female rat MCCs and ERRα expression levels. Liposome transfection and XCT‑790 were used to overexpress and inhibit ERRα expression, respectively, and then qPCR was performed to detect changes in the biological characteristics of MCCs. ERRα expression was detected in the nucleus and cytoplasm of rat MCCs. 17‑β estradiol (E2) (10‑8 M) increased the mRNA and protein expression levels of ERRα, Sox9, GDF‑5 and aromatase during in vitro MCC cultivation. In addition, E2 affected MCC proliferation through the regulation of ERRα expression levels. Overexpression of ERRα positively regulated the mRNA and protein expression levels of Sox9 and GDF‑5, but did not exhibit a significant effect on the mRNA and protein expression levels of aromatase and Col2a1. In conclusion, ERRα exhibited an important regulatory role in the proliferation and differentiation of female Sprague‑Dawley rat MCCs in vitro through regulating Sox9 and GDF-5.