Purpose: To investigate whether bile acids transporters organic anion transporting polypeptides 1A2 (OATP1A2), organic anion transporting polypeptides 1B1 (OATP1B1), organic anion transporting polypeptides 1B3 (OATP1B3) were differently expressed in placenta of intrahepatic cholestasis of pregnancy (ICP).
Methods: Thirty pregnant women with ICP were recruited and 30 normal pregnant women served as control. The expression of mRNA and protein were analyzed by real-time PCR and Western blotting. The localization of OATP1A2, OATP1B1, OATP1B3 were investigated by immunohistochemistry.
Results: The expression of mRNA and protein of both OATP1A2 and OATP1B3 were significantly lower in ICP placenta than normal placenta (P < 0.05). OATP1B1 mRNA was detected by RT-PCR in 8 ICP placentas and 7 control placentas, but protein expression of OATP1B1 was not found in any of the 60 placentas. By immunohistochemistry we found that OATP1A2 was obviously localized to vasculo-syncytial membrane (VSM) and apical surface of syncytiotrophoblasts, while OATP1B3 was localized to VSM of the syncytiotrophoblasts.
Conclusions: The expression of OATP1A2 and OATP1B3 in placenta decreased in ICP. The down-regulation of these transporters may be involved in the pathophysiology of ICP.