Department of Urology, the Fourth Affiliated Hospital of China Medical University, No.4, Chong-shan East Road, Shenyang 110032, Liaoning Province, PR China.
Department of Surgical Oncology, the First Affiliated Hospital of China Medical University, No.155, Nan-jing North Street, Shenyang 110001, Liaoning Province, PR China.
Cell Calcium. 2019 Jan;77:8-19. doi: 10.1016/j.ceca.2018.11.007. Epub 2018 Nov 17.
It has been suggested that FK506 could improve some symptoms of OAB in both clinical settings and animal models; however, its mechanism of action is not well-understood. Here, we investigated the effect of FK506 on TRPC6 in bladder smooth muscle, and explored the possible involvement of TRPC6 in OAB.
FK506 was injected intraperitoneally into rats in which OAB was induced via BOO, and urodynamic indices were recorded. Rats and human bladder smooth muscle tissues with or without OAB were examined for TRPC6 expression by western blot, RT-PCR and IF staining. Cultured BSMCs were treated with PDGF, TRPC6 siRNAs and FK506. Then the TRPC6 expression and cellular proliferation were examined, and the Ca influx and contractility of BSMCs were examined by time-lapse Ca imaging and collagen gel contraction. Finally, IF and Co-IP were performed to test the effects of FK506 on NFAT translocation to the nucleus and the interaction of TRPC6 with FKBP12, respectively.
FK506 improved urodynamic indices of OAB rats, and TRPC6 was expressed in rats and human bladder tissues. TRPC6 elevation in OAB rats was inhibited by FK506, and this inhibition coincided with improvements in urodynamic indices. PDGF enhanced TRPC6 expression, cellular proliferation, Ca influx and contractility of BSMCs, and these effects were inhibited by TRPC6 siRNAs and FK506. FK506 inhibited NFAT translocation to the nucleus and disrupted the interaction of TRPC6 with FKBP12.
Our results collectively indicate that FK506 may be used to treat OAB, and that TRPC6 may serve as an attractive target for therapeutic intervention in OAB.
有研究表明，FK506 可改善临床和动物模型中 OAB 的某些症状；然而，其作用机制尚不清楚。在这里，我们研究了 FK506 对膀胱平滑肌 TRPC6 的影响，并探讨了 TRPC6 参与 OAB 的可能机制。
通过 BOO 诱导 OAB 后，将 FK506 腹腔注射到大鼠体内，并记录尿动力学指标。通过 Western blot、RT-PCR 和 IF 染色检测有或无 OAB 的大鼠和人膀胱平滑肌组织中 TRPC6 的表达。用 PDGF、TRPC6 siRNA 和 FK506 处理培养的 BSMC。然后检测 TRPC6 的表达和细胞增殖，通过延时钙成像和胶原凝胶收缩检测 BSMC 的 Ca 内流和收缩性。最后，通过 IF 和 Co-IP 分别检测 FK506 对 NFAT 向核内转移以及 TRPC6 与 FKBP12 相互作用的影响。
FK506 改善了 OAB 大鼠的尿动力学指标，并且在大鼠和人膀胱组织中均表达 TRPC6。FK506 抑制了 OAB 大鼠的 TRPC6 升高，这种抑制与尿动力学指标的改善相一致。PDGF 增强了 BSMC 中 TRPC6 的表达、细胞增殖、Ca 内流和收缩性，而这些作用被 TRPC6 siRNA 和 FK506 所抑制。FK506 抑制了 NFAT 向核内转移，并破坏了 TRPC6 与 FKBP12 的相互作用。
我们的研究结果表明，FK506 可用于治疗 OAB，TRPC6 可能是 OAB 治疗干预的一个有吸引力的靶点。
