MR 04. The inhibitory effect of Cox7a2 on the LH induced testosterone production in TM3 mouse Leydig cells

Cox7a2 is the gene encoding one component of the nuclearencoded subunits of cytochrome c oxidase complex in the mitochondrial respiratory chain. Cox7a2 had been shown high expressed in the testes of aging males, but the significance of its high expression pattern was not clear presently. In our study, we investigated the effect of Cox7a2 on testosterone production in TM3 mouse Leydig cells, and the involvement mechanism of this effect. Cox7a2-pEYFP-N1 plamid was construced and transfected back to TM3 mouse Leydig cells for the overpression of Cox7a2. The testosterone secretion was tested by ELISA and the expression of StAR, P450scc and 3β-HSD was investigated by western blotting. The investigations suggested that Cox7a2 inhibited the LH-induced testosterone production at least by disrupting the expression of StAR protein, other than the expression of P450scc and 3β-HSD enzymes in TM3 mouse Leydig cells.