Changes in the expression of claudins and transepithelial electrical resistance of mouse Sertoli cells by Leydig cell coculture

In the testis, tight junctions (TJs) between adjacent Sertoli cells are important for the formation of blood-testis barrier (BTB). To verify the role of paracrine interactions between the Sertoli and Leydig cells in the structure and function of BTB in testis, the expression of claudin-1 and -11, and transepithelial electrical resistance (TER) of the mouse Sertoli cells were examined under the Leydig cell coculture. TER of Sertoli cell monolayer was significantly larger under the Leydig cell coculture in comparison with the control culture. Meanwhile, the expression of claudin-1 slightly decreased and claudin-11 significantly increased in the Sertoli cells in the Leydig cell coculture compared with control. Testosterone significantly increased claudin-11 expression in cultured Sertoli cells. Taken together, it suggested that Leydig cell coculture changed the structure and functions of inter-Sertoli TJs in vitro. Interactions between Leydig and Sertoli cells might be involved in the development of functional blood testis barrier in mouse testis.