ABSTRACT
Objective To investigate the regulation of blood-testis barrier by Rab13-PKA pathway in rats.Meth-od First, shRNA vector targeting at Rab13 was constructed and then the Rab13 shRNA was transfected into the rat testis by injection.Western blot was used to detect the knock-down effect of Rab13 and the expression of blood-testis barrier ( BTB) constituent proteins.PKA activity was detected by autoradiography and scintillation counting.Further, immunoflu-orescence analysis and phalloidin staining were applied to observe the distribution of occludin and F-actin, respectively. Results The expression level of Rab13 in the testis was reduced by approximately 70%after transfection of Rab13 shRNA as compared with the non-targeted control group ( P<0.01 ) , while the expression of BTB constituent proteins remained unchanged.PKA activity was significantly increased after Rab13 RNAi transfection (P<0.01).The distribution of occlu-din at BTB was remarkably increased after Rab13 RNAi silencing around stage VIII but not at other stages of the seminifer-ous epithelial cycle.The assembly of F-actin at BTB was also intensified in Rab13-silenced testis.Both the changes of dis-tribution of occludin and F-actin induced by Rab13 shRNA were found to be antagonized by the PKA specific inhibitor H89.Conclusions Rab13 can modulate the distribution of occludin and F-actin at the blood-testis barrier in rats by regu-lating PKA activity, which may participate in the regulation of BTB function.