Knockdown of lncRNA KCNQ1OT1 suppresses the adipogenic and osteogenic differentiation of tendon stem cell via downregulating miR-138 target genes PPARγ and RUNX2

Abstract

The study aimed to investigate the mechanism and biological roles of long noncoding RNA KCNQ1OT1 in adipogenic and osteogenic differentiation of tendon stem cell. In this study, tendon injury mice model was established to detect the expression of lncRNA KCNQ1OT1, miR-138, peroxisome proliferator-activated receptor gamma (PPARγ) and runt-related gene 2 (RUNX2) using quantitative real-time PCR (qRT-PCR) and western blot. Mechanical testing was carried out to assess tendon function. Adiponectin and Osterix were used to evaluate the adipogenic and osteogenic differentiation of tendon stem cells (TSCs). The interaction between lncRNA KCNQ1OT1 and miR-138 was detected by RNA immunoprecipitation (RIP) assay and RNA pulldown assay. We found that lncRNA KCNQ1OT1, PPARγ and RUNX2 expression were significantly upregulated, while miR-138 was suppressed in tendon tissue of injured group and the separated TSCs. lncRNA KCNQ1OT1 knockdown inhibited the adipogenic and osteogenic differentiation of TSCs. Further studies indicated that lncRNA KCNQ1OT1 functioned as a competing endogenous RNA (ceRNA) by sponging miR-138 in TSCs. Further investigations confirmed that lncRNA KCNQ1OT1 knockdown exerted anti-adipogenic and anti-osteogenic function via miR-138/PPARγ and miR-138/RUNX2 axis. Therefore, the lncRNA KCNQ1OT1/miR-138/PPARγ or RUNX2 axis modulated adipogenic and osteogenic differentiation of tendon stem cell, which might be a promising therapeutic target for tendon injuries.

MicroRNA-138 Suppresses Adipogenic Differentiation in Human Adipose Tissue-Derived Mesenchymal Stem Cells by Targeting Lipoprotein Lipase

“…Interestingly, dysregulation of miR-138 has also been observed in stem cells from injury tissue. Yu, et al15 proposed that the expression of miR-138 is attenuated in tendon stem cells from injured mice and that miR-138 may mediate the anti-adipogenic differentiation function of lncRNA KCNQ1OT1 knockdown by targeting PPARγ. Moreover, Nardelli, et al21 indicated that miR-138 together with miR-222-3p is overexpressed in hAMSCs from obese-pregnant women.…”

“…Studies have revealed that various miRNAs affect adipogenesis by targeting several adipogenic transcription factors and key signaling molecules in vivo and in vitro 59. Among them, PPARγ is an important regulator of adipogenic differentiation and is targeted by several miRNAs, such as miR-27a/b, miR-130, and miR-138 15202223. The adipogenic commitment of tendon stem cells was suppressed by lncRNA KCNQ1OT1 knockdown via downregulating miR-138-targeted PPARγ, accompanying a loss of the adipogenic marker gene adiponectin 15.…”

“…Emerging evidence has demonstrated dysregulation of miR-138 in adipocytes 1314. In tendon stem cells from injured mice, silencing of lncRNA KCNQ1OT1 exerted anti-adipogenic function by directly upregulating miR-138 15. Additionally, miR-138 was claimed to be downregulated in adipogenic differentiation of hAMSCs 1216.…”

“…Additionally, miR-138 was claimed to be downregulated in adipogenic differentiation of hAMSCs 1216. Although a potential role has been proposed for miR-138 in modulating adipogenic differentiation,1516 the precise mechanism underlying this remains unclear.…”

Competing Endogenous RNAs, Non-Coding RNAs and Diseases: An Intertwined Story

“…Instances of ceRNA crosstalk were experimentally tested in a very large number of contexts and were observed in both normal and pathological backgrounds, demonstrating the wide spread proliferation of the mechanism. In particular, researchers collected evidence from normal physiology, for instance in brain architecture [ 86 ] and regeneration mechanisms [ 87 ], neuronal and muscle developmental processes [ 50 , 88 ], cellular differentiation [ 89 ] and reprogramming [ 90 , 91 ] and from the immense landscape of diseases, syndromes and disorders where highly complex gene regulation circuits are most affected by perturbations. Researchers work hard to model these regulatory networks in order to predict and understand how modifications could alter the dynamic balance among molecules, causing illness such as the onset of cancer and its progression, cardiovascular problems and neurodegenerative disorders and other pathologies, such as those relating to the immune and autoimmune response and to degenerative physical condition.…”