miR‑339‑5p negatively regulates loureirin A‑induced hair follicle stem cell differentiation by targeting DLX5

Abstract

Our previous study indicated that loureirin A induces hair follicle stem cell (HFSC) differentiation through Wnt/β-catenin signaling pathway activation. However, if and how microRNAs (miRNAs/miRs) modulate loureirin A-induced differentiation remains to be elucidated. In the present study, HFSCs were separated from the vibrissae of rats and identified by CD34 and keratin, type 1 cytoskeletal (K)15 expression. Microarray-based miRNA profiling analysis revealed that miR-339-5p was downregulated in loureirin A-induced HFSC differentiation. miR-339-5p overexpression by transfection with miR-339-5p mimics markedly inhibited the expression of K10 and involucrin, which are markers of epidermal differentiation, whereas inhibition of miR-339-5p by miR-339-5p inhibitor transfection promoted the expression of K10 and involucrin. These results suggest that miR-339-5p is a negative regulator of HFSC differentiation following induction by loureirin A. These findings were confirmed by a luciferase assay. Homeobox protein DLX-5 (DLX5) was identified as a direct target of miR-339-5p. Furthermore, it was demonstrated that miR-339-5p inhibited DLX5. Overexpression of miR-339-5p by mimic transfection significantly inhibited protein Wnt-3a (Wnt3a) expression, while inhibition of miR-339-5p by inhibitor transfection significantly increased the expression of Wnt3a. Furthermore, small interfering RNA targeting DLX5 was transfected into HFSCs, and western blot analysis revealed that Wnt3a, involucrin and K10 expression was significantly downregulated. Taken together, these results suggest that miR-339-5p negatively regulated loureirin A-induced HFSC differentiation by targeting DLX5, resulting in Wnt/β-catenin signaling pathway inhibition. This may provide a possible therapeutic target for skin repair and regeneration.

RETRACTED ARTICLE: Up-regulated lncRNA5322 elevates MAPK1 to enhance proliferation of hair follicle stem cells as a ceRNA of microRNA-19b-3p

“…MicroRNAs (miRs) are a family of short non-coding RNAs with the length of 21-24 nucleotides, which exert crucial roles in multiple cellular processes such as cell progression, proliferation and differentiation [10]. In particular, miR-214 and miR-125b have been found to operate as key mediators of HF maintenance in the telogen stage through their suppressive roles in HFSCs proliferation and differentiation [11]. Similarly, miR-19b-3p was confirmed to be associated with an enhanced proliferation of goat male germline stem cells [12].…”

ADSCs inhibit photoaging‐ and photocarcinogenesis‐related inflammatory responses and extracellular matrix degradation

“…These findings suggest that the quantity of HFSCs decreased in photoaging skin and increased after ADSCs transplantation. The transient quiescence of HFSCs after UVB irradiation may be a protective mechanism against photocarcinogenesis …”

“…The absence or malfunction of HFSCs is linked to a damaged initial healing response to full‐thickness injury of the skin in a mouse model . Evidence showed that adipose‐derived stem cells (ADSCs) enhance angiogenesis, re‐epithelialization, and extracellular matrix (ECM) deposition, which are essential to the restoration of skin protective screen function .…”

The Role of MicroRNAs in Epidermal Barrier

“…Instead of the association of these components with miRNAs as direct targets or regulators, the altered expression of filaggrin, involucrin, and loricrin is accompanied by changes in other differentiation markers and barrier proteins as described in keratinocyte differentiation associated with upregulation of miR-203 and miR-184 [20,23,32]. Downregulation of miR-339-5p increases levels of distal-less homeobox5 (DLX5), leading to involucrin upregulation via activation of the Wnt/β-catenin signaling pathway [91]. Dicer is involved in the regulation of skin barrier function [100].…”