Downregulation of TRPC6 expression is a critical molecular event during FK506 treatment for overactive bladder

Cheng Chang; Kai Li; Sinan Jiang; Baoman Li; Liu Cao; Ping Wang

doi:10.1016/j.ceca.2018.11.007

Downregulation of TRPC6 expression is a critical molecular event during FK506 treatment for overactive bladder

Cell Calcium. 2019 Jan:77:8-19. doi: 10.1016/j.ceca.2018.11.007. Epub 2018 Nov 17.

Authors

Cheng Chang¹, Kai Li², Sinan Jiang¹, Baoman Li³, Liu Cao⁴, Ping Wang⁵

Affiliations

¹ Department of Urology, the Fourth Affiliated Hospital of China Medical University, No.4, Chong-shan East Road, Shenyang 110032, Liaoning Province, PR China.
² Department of Surgical Oncology, the First Affiliated Hospital of China Medical University, No.155, Nan-jing North Street, Shenyang 110001, Liaoning Province, PR China.
³ Department of Brain Metabolic Diseases Laboratory, Institute of Metabolic Disease Research and Drug Development, China Medical University, No.77, Puhe Road, Shenyang 110122, Liaoning Province, PR China.
⁴ Department of Key Laboratory of Medical Cell Biology (Ministry of Education), the Institute of Translational Medicine, China Medical University, No.77, Puhe Road, Shenyang 110122, Liaoning Province, PR China.
⁵ Department of Urology, the Fourth Affiliated Hospital of China Medical University, No.4, Chong-shan East Road, Shenyang 110032, Liaoning Province, PR China. Electronic address: pwang@cmu.edu.cn.

PMID: 30476735
DOI: 10.1016/j.ceca.2018.11.007

Abstract

Purpose: 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.

Methods: 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 Ca²⁺ influx and contractility of BSMCs were examined by time-lapse Ca²⁺ 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.

Results: 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, Ca²⁺ 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.

Conclusions: 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.

Keywords: BSMC; Calcium; FK506; OAB; PDGF; TRPC6.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Disease Models, Animal
Down-Regulation / drug effects*
Female
Humans
Rats
Rats, Wistar
TRPC Cation Channels / biosynthesis*
TRPC6 Cation Channel / biosynthesis*
Tacrolimus / pharmacology*
Urinary Bladder, Overactive* / drug therapy
Urinary Bladder, Overactive* / metabolism
Urinary Bladder, Overactive* / pathology
Urodynamics / drug effects*

Substances

TRPC Cation Channels
TRPC6 Cation Channel
TRPC6 protein, human
Trpc6 protein, rat
Tacrolimus