MicroRNA-148b promotes proliferation of hair follicle cells by targeting NFAT5

Wanbao Yang,Mei Yu,Bo Su,Qinqun Li

doi:10.15302/j-fase-2016089

Abstract

MicroRNAs (miRNAs), small non-coding RNAs, are involved in many aspects of biological processes. Previous studies have indicated that miRNAs are important for hair follicle development and growth. In our study, we found by qRT-PCR that miR-148b was significantly upregulated in sheep wool follicle bulbs in anagen phase compared with the telogen phase of the hair follicle cycle. Overexpression of miR-148b promoted proliferation of both HHDPC and HHGMC. By using the TOPFlash system we demonstrated that miR-148b could activate Wnt/β-catenin pathway and b-catenin, cycD, c-jun and PPARD were consistently upregulated accordingly. Furthermore, transcript factor nuclear factor of activated T cells type 5 (NFAT5) and Wnt10b were predicted to be the target of miR-148b and this was substantiated using a Dual-Luciferase reporter system. Subsequently NFAT5 was further identified as the target of miR-148b using western blotting. These results were considered to indicate that miR-148b could activate the Wnt/β-catenin signal pathway by targeting NFAT5 to promote the proliferation of human hair follicle cells.

Highlights

Hairs, unique to mammals, are organs found in the skin and have various functions[1,2]
We found through Solexa sequencing that the expression of miR-148b in the anagen of wool bulbs was over 5 times the level in telogen, which indicates a potential role of miR-148b in the wool cycle in Tibetan sheep[28]
The role of NFAT5 in hair follicles still remains unclear, we have provided evidence that miR-148b targets Wnt10b and NFAT5 to regulate the proliferation of hair follicle cells

Summary

Introduction

Unique to mammals, are organs found in the skin and have various functions[1,2]. Unlike other organs during the postnatal life, hair follicles undergo a cyclic period including growth (anagen), regression (catagen) and quiescence (telogen), in which a large number of molecular signals participate. It has been reported that the miRNA, miR24 promotes hair follicle development by directly targeting Tcf-3 and miR-31 regulates anagen progression and hair follicle formation via inhibiting a number of growth regulatory molecules and cytoskeletal proteins[31,32]. The role of miRNAs in hair follicle development and growth has recently been explored, the specific molecular mechanisms involved are still unknown. The specific function and underlying molecular mechanism of miR-148b in hair follicle growth remain unknown

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