Downregulation of miR-24-3p promotes osteogenic differentiation of human periodontal ligament stem cells by targeting SMAD family member 5

The signaling pathways involved in non-coding RNA regulation during osteogenic differentiation of periodontal tissue-derived cells in the field of periodontitis

Periodontitis is a prevalent oral disease caused by chronic inflammation of the periodontal tissues surrounding the teeth, which can lead to bone loss, tooth loosening, and even tooth loss. This inflammation has a negative impact on the osteogenic differentiation capacity of periodontal tissue-derived cells. Non-coding RNAs (ncRNAs) are a class of RNA molecules that do not encode proteins but can regulate various physiological processes. In this review, we summarized the critical signaling pathways that ncRNAs modulate in osteogenic differentiation of periodontal tissue-derived cells, such as the Wnt, BMP/Smad, NF-κB, and PI3-K/Akt/mTOR pathways. This comprehensive exploration of ncRNA-mediated modulation offers fresh and promising insights for prospective approaches in the management of periodontitis and the advancement of periodontal regeneration therapies.

Emerging Role of miRNAs in the Pathogenesis of Periodontitis

MicroRNAs (miRNAs) have been found to participate in the pathogenesis of several immune-related conditions through the modulation of the expression of cytokine coding genes and other molecules that affect the activity of the immune system. Periodontitis is an example of these conditions associated with the dysregulation of several miRNAs. Several miRNAs such as let-7 family, miR-125, miR-378, miR-543, miR-302, miR-214, miR-200, miR-146, miR-142, miR-30 and miR-21 have been shown to be dysregulated in patients with periodontitis. miR-146 is the most assessed miRNA in these patients, which is up-regulated in most studies in patients with periodontitis. In the present review, we describe the impact of miRNAs dysregulation on the pathoetiology of periodontitis.

Interference of a mammalian circRNA regulates lipid metabolism reprogramming by targeting miR-24-3p/Igf2/PI3K-AKT-mTOR and Igf2bp2/Ucp1 axis

White adipose tissue (WAT) is important for regulating the whole systemic energy homeostasis. Excessive WAT accumulation further contributes to the development of obesity and obesity-related illnesses. More detailed mechanisms for WAT lipid metabolism reprogramming, however, are still elusive. Here, we report the abnormally high expression of a circular RNA (circRNA) mmu_circ_0001874 in the WAT and liver of mice with obesity. mmu_circ_0001874 interference achieved using a specific adeno-associated virus infects target tissues, down-regulating lipid accumulation in the obesity mice WAT, and liver tissues. Mechanistically, miR-24-3p directly interacts with the lipid metabolism effect of mmu_circ_0001874 and participates in adipogenesis and lipid accumulation by targeting Igf2/PI3K-AKT-mTOR axis. Moreover, mmu_circ_0001874 binds to Igf2bp2 to interact with Ucp1, up-regulating Ucp1 translation and increasing thermogenesis to decrease lipid accumulation. In conclusion, our data highlight a physiological role for circRNA in lipid metabolism reprogramming and suggest mmu_circ_0001874/miR-24-3p/Igf2/PI3K-AKT-mTOR and mmu_circ_0001874/Igf2bp2/Ucp1 axis may represent a potential mechanism for controlling lipid accumulation in obesity.

Post-Transcriptional Regulatory Crosstalk between MicroRNAs and Canonical TGF-β/BMP Signalling Cascades on Osteoblast Lineage: A Comprehensive Review

MicroRNAs (miRNAs) are a family of small, single-stranded, and non-protein coding RNAs about 19 to 22 nucleotides in length, that have been reported to have important roles in the control of bone development. MiRNAs have a strong influence on osteoblast differentiation through stages of lineage commitment and maturation, as well as via controlling the activities of osteogenic signal transduction pathways. Generally, miRNAs may modulate cell stemness, proliferation, differentiation, and apoptosis by binding the 3'-untranslated regions (3'-UTRs) of the target genes, which then can subsequently undergo messenger RNA (mRNA) degradation or protein translational repression. MiRNAs manage the gene expression in osteogenic differentiation by regulating multiple signalling cascades and essential transcription factors, including the transforming growth factor-beta (TGF-β)/bone morphogenic protein (BMP), Wingless/Int-1(Wnt)/β-catenin, Notch, and Hedgehog signalling pathways; the Runt-related transcription factor 2 (RUNX2); and osterix (Osx). This shows that miRNAs are essential in regulating diverse osteoblast cell functions. TGF-βs and BMPs transduce signals and exert diverse functions in osteoblastogenesis, skeletal development and bone formation, bone homeostasis, and diseases. Herein, we highlighted the current state of in vitro and in vivo research describing miRNA regulation on the canonical TGF-β/BMP signalling, their effects on osteoblast linage, and understand their mechanism of action for the development of possible therapeutics. In this review, particular attention and comprehensive database searches are focused on related works published between the years 2000 to 2022, using the resources from PubMed, Google Scholar, Scopus, and Web of Science.

Non-coding RNAs regulate the BMP/Smad pathway during osteogenic differentiation of stem cells

MicroRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) are involved in the regulation of bone metabolism. The BMP/Smad pathway is a key signaling pathway for classical regulation of osteogenic differentiation. Non-coding RNAs (ncRNAs) and the BMP/Smad pathway both have important roles for osteogenic differentiation of stem cells, bone regeneration, and development of bone diseases. There is increasing evidence that ncRNAs interact with the BMP/Smad pathway to regulate not only osteogenic differentiation of stem cells but also progression of bone diseases, such as osteoporosis (OP), myeloma, and osteonecrosis of the femoral head (ONFH), by controlling the expression of bone disease-related genes. Therefore, ncRNAs that interact with BMP/Smad pathway molecules are potential targets for bone regeneration as well as bone disease diagnosis, prevention, and treatment. However, despite extensive studies on ncRNAs associated with the BMP/Smad pathway and osteogenic differentiation of stem cells, there is a lack of comparability. Moreover, some bone disease-associated ncRNAs with low abundance can be difficult to detect and there is a lack of mature delivery systems for their stable translocation to target sites, thus limiting their application. In this review, we summarize the research progress on interactions between ncRNAs and the BMP/Smad pathway during osteogenic differentiation of various stem cells and in the regulation of bone regeneration and bone diseases.

Zuogui Pill Ameliorates Glucocorticoid-Induced Osteoporosis through ZNF702P-Based ceRNA Network: Bioinformatics Analysis and Experimental Validation

Glucocorticoid-induced osteoporosis (GIOP) is a musculoskeletal disease with increased fracture risk caused by long-term application of glucocorticoid, but there exist few effective interventions. Zuogui Pill (ZGP) has achieved clinical improvement for GIOP as an ancient classical formula, but its molecular mechanisms remain unclear due to scanty relevant studies. This study aimed to excavate the effective compounds and underlying mechanism of ZGP in treating GIOP and construct relative ceRNA network by using integrated analysis of bioinformatics analysis and experimental validation. Results show that ZNF702P is significantly upregulated in GIOP than normal cases based on gene chip sequencing analysis. Totally, 102 ingredients and 535 targets of ZGP as well as 480 GIOP-related targets were selected, including 122 common targets and 8 intersection targets with the predicted mRNAs. The ceRNA network contains one lncRNA (ZNF702P), 6 miRNAs, and 8 mRNAs. Four hub targets including JUN, CCND1, MAPK1, and MAPK14 were identified in the PPI network. Six ceRNA interaction axes including ZNF702P-hsa-miR-429-JUN, ZNF702P-hsa-miR-17-5p/hsa-miR-20b-5p-CCND1, ZNF702P-hsa-miR-17-5p/hsa-miR-20b-5p-MAPK1, and ZNF702P-hsa-miR-24-3p-MAPK14 were obtained. By means of molecular docking, we found that all the hub targets could be effectively combined with related ingredients. GO enrichment analysis showed 649 biological processes, involving response to estrogen, response to steroid hormone, inflammatory response, macrophage activation, and osteoclast differentiation, and KEGG analysis revealed 102 entries with 36 relative signaling pathways, which mainly contained IL-17 signaling pathway, T cell receptor signaling pathway, FoxO signaling pathway, the PD-L1 expression and PD-1 checkpoint pathway, MAPK signaling pathway, TNF signaling pathway, Estrogen signaling pathway, and Wnt signaling pathway. Our experiments confirmed that ZNF702P exhibited gradually increasing expression levels during osteoclast differentiation of human peripheral blood monocytes (HPBMs) induced by RANKL, while ZGP could inhibit osteoclast differentiation of HPBMs induced by RANKL in a concentration-dependent manner. Therefore, by regulating inflammatory response, osteoclast differentiation, and hormone metabolism, ZGP may treat GIOP by regulating hub target genes, such as JUN, CCND1, MAPK1, and MAPK14, and acting on numerous key pathways, which involve the ZNF702P-based ceRNA network.

miR-589-3p promoted osteogenic differentiation of periodontal ligament stem cells through targeting ATF1

Background

An increasing number of studies have shown that dysregulated miR-589-3p is associated with multiple diseases. However, the role of miR-589-3p in osteogenic differentiation of periodontal ligament stem cells (PDLSCs) remains unknown. This study aimed to explore the biological function and potential molecular mechanism of miR-589-3p in osteogenic differentiation of PDLSCs.

Methods

GSE159508 was downloaded from Gene Expression Omibus (GEO, http://www.ncbi.nlm.nih.gov/geo/). Differentially expressed miRNAs between osteogenic induction PDLSCs versus non-induction PDLSCs were obtained by R software. miR-589-3p mimic and miR-589-3p inhibitor and corresponding negative control were obtained and to identify the role of miR-589-3p in osteogenic differentiation of PDLSCs. ALP staining and ARS were used to evaluate ALP activity and mineralization, respectively. The targeted binding relationship between miR-589-3p and ATF1 was predicted and verified by target prediction analysis and dual-luciferase assay. Furthermore, the functional mechanism based on miR-589-3p and ATF1 in osteogenic differentiation of PDLSCs was further investigated through rescue experiments.

Results

According to the cut-off criteria with log 2 FC > 1.0 and P < 0.05, 514 differentially expressed miRNAs were identified between osteogenic induction and non-induction PDLSCs, including 309 upregulated miRNAs and 205 downregulated miRNAs. Compared with control PDLSCs, miR-589-3p expression level was notably increased in PDLSCs that underwent osteogenic induction. The overexpression of miR-589-3p promoted the cell viability of PDLSCs, while the low expression of miR-589-3p had the opposite effect. The dual luciferase reporter assay verified that ATF1 was proved to be a direct target of miR-589-3p in PDLSCs. And overexpressed miR-589-3p reduced the expression of ATF1. Overexpression of miR-589-3p enhanced the osteogenic capacity of PDLSCs, as demonstrated by increases in ALP activity, matrix mineralization, and RUNX2, OCN and OSX expression. In addition, the rescue experiments confirmed that overexpressed ATF1 restored the effects of overexpressed miR-589-3p on cell proliferation and osteogenic differentiation of PDLSCs.

Conclusion

miR-589-3p could down-regulate the expression of ATF1, thereby promote the proliferation and osteogenic differentiation of PDLSCs. This finding may provide a new therapeutic target for molecular therapy of periodontitis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03000-z.

Deciphering the Epigenetic Code of Stem Cells Derived From Dental Tissues

Stem cells derived from dental tissues (DSCs) exhibit multipotent regenerative potential in pioneering tissue engineering regimens. The multipotency of DSCs is critically regulated by an intricate range of factors, of which the epigenetic influence is considered vital. To gain a better understanding of how epigenetic alterations are involved in the DSC fate determination, the present review overviews the current knowledge relating to DSC epigenetic modifications, paying special attention to the landscape of epigenetic modifying agents as well as the related signaling pathways in DSC regulation. In addition, insights into the future opportunities of epigenetic targeted therapies mediated by DSCs are discussed to hold promise for the novel therapeutic interventions in future translational medicine.

CircRNA FAT1 Regulates Osteoblastic Differentiation of Periodontal Ligament Stem Cells via miR-4781-3p/SMAD5 Pathway

The ability of human periodontal ligament stem cells (PDLSCs) to differentiate into osteoblasts is significant in periodontal regeneration tissue engineering. In this study, we explored the role and mechanism of circRNA FAT1 (circFAT1) in the osteogenic differentiation of human PDLSCs. The proliferation capacity of PDLSCs was evaluated by EdU and CCK-8 assay. The abilities of circFAT1 and miR-4781-3p in regulating PDLSC differentiation were analyzed by western blot, reverse transcription-polymerase chain reaction (RT-PCR), alkaline phosphatase (ALP), and Alizarin red staining (ARS). A nucleocytoplasmic separation experiment was utilized for circFAT1 localization. A dual-luciferase reporter assay confirmed the binding relationship between miR-4781-3p and circFAT1. It was showed that circFAT1 does not affect the proliferation of PDLSCs. The osteogenic differentiation of PDLSCs was benefited from circFAT1, which serves as a miRNA sponge for miR-4781-3p targeting SMAD5. Both knockdown of circFAT1 and overexpression of miR-4781-3p suppressed the osteogenic differentiation of PDLSCs. Thus, circFAT1 might be considered as a potential target of PDLSCs mediated periodontal bone regeneration.

Long non-coding RNA potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 regulates the proliferation and osteogenic differentiation of human periodontal ligament stem cells by targeting miR-24-3p

OBJECTIVES

This study aims to explore the effect and molecular mechanism of long non-coding RNA (lncRNA) potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (KCNQ1OT1) on proliferation and osteogenic differentiation in human periodontal ligament stem cells (hPDLSCs).

METHODS

The hPDLSCs of normal periodontal tissues were isolated and cultured. The mineralized solution induced the osteoblast differentiation of hPDLSCs. The down-regulation of lncRNA KCNQ1OT1, the overexpression of anti-miR-24-3p on the proliferation and the levels of osteocalcin (OCN), osteopontin (OPN) and alkaline phosphatase (ALP) of hPDLSCs were investigated. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the levels of lncRNA KCNQ1OT1, miR-24-3p, OCN, OPN, and ALP. Methyl thiazolyl tetrazolium (MTT) method was used to detect cell viability and activity. Cell proliferation was evaluated by MTT. Western blot was used to detect protein expression. The targeted relationship between lncRNA KCNQ1OT1 and miR-24-3p was detected by double-luciferase experiment.

RESULTS

The expression level of lncRNA KCNQ1OT1 increased, and that of miR-24-3p decreased during the osteogenesis of hPDLSCs (P<0.05). The down-regulation of lncRNA KCNQ1OT1 inhibited cell proliferation and reduced the mRNA and protein expression levels of OCN, OPN, and ALP (P<0.05). LncRNA KCNQ1OT1 targeted and regulated miR-24-3p. The overexpression of miR-24-3p inhibited cell proliferation and reduced the mRNA and protein expression levels of OCN, OPN, and ALP (P<0.05). Inhibition of miR-24-3p reversed the effect of the down-regulation of lncRNA KCNQ1OT1 on cell proliferation and mRNA and protein expression levels of OCN, OPN, and ALP (P<0.05).

CONCLUSIONS

Down-regulation of lncRNA KCNQ1OT1 inhibited the proliferation and osteogenic differentiation of hPDLSCs by targeting the up-regulated expression of miR-24-3p.

Multidifferentiation potential of dental-derived stem cells

Tooth-related diseases and tooth loss are widespread and are a major public health issue. The loss of teeth can affect chewing, speech, appearance and even psychology. Therefore, the science of tooth regeneration has emerged, and attention has focused on tooth regeneration based on the principles of tooth development and stem cells combined with tissue engineering technology. As undifferentiated stem cells in normal tooth tissues, dental mesenchymal stem cells (DMSCs), which are a desirable source of autologous stem cells, play a significant role in tooth regeneration. Researchers hope to reconstruct the complete tooth tissues with normal functions and vascularization by utilizing the odontogenic differentiation potential of DMSCs. Moreover, DMSCs also have the ability to differentiate towards cells of other tissue types due to their multipotency. This review focuses on the multipotential capacity of DMSCs to differentiate into various tissues, such as bone, cartilage, tendon, vessels, neural tissues, muscle-like tissues, hepatic-like tissues, eye tissues and glands and the influence of various regulatory factors, such as non-coding RNAs, signaling pathways, inflammation, aging and exosomes, on the odontogenic/osteogenic differentiation of DMSCs in tooth regeneration. The application of DMSCs in regenerative medicine and tissue engineering will be improved if the differentiation characteristics of DMSCs can be fully utilized, and the factors that regulate their differentiation can be well controlled.

MicroRNA-24-3p Inhibits Microglia Inflammation by Regulating MK2 Following Spinal Cord Injury

Spinal cord injury (SCI) is a functional impairment of the spinal cord caused by external forces, accompanied by limb movement disorders and permanent paralysis, which seriously lowers the life quality of SCI patients. Secondary injury caused by inflammation attenuated the therapeutic effects of SCI. Therefore, the exploration of biomarkers associated with the inflammatory response following SCI might provide novel therapy strategy against SCI.SCI rat model was established as previously reported and evaluated by BBB score. The expression of microRNA-24-3p (miR-24-3p) and MAPK-activated protein kinase 2 (MK2) in spinal cord tissues of SCI rats and HAPI cells was analyzed by qRT-PCR. Protein expression of MK2, ionized calcium-binding adapter molecule-1 (Iba-1), tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β) was assessed by western blot assay. The release of inflammatory cytokines TNF-α and IL-1β was measured by enzyme-linked immunosorbent assay (ELISA). The interaction between miR-24-3p and MK2 was examined by the luciferase reporter system. Basso-Beattie-Bresnahan (BBB) score dramatically reduced in rats following SCI compared with sham rats. Moreover, the expression of miR-24-3p was down-regulated, while MK2 was up-regulated in the spinal cord tissues of SCI rats and LPS-induced microglia cells compared with the corresponding control group. Luciferase reporter system confirmed the interaction between miR-24-3p and MK2. In addition, miR-24-3p upregulation or MK2 knockdown attenuated LPS induced activation of microglial cells and expression of inflammatory cytokine TNF-α and IL-1β. Besides, we discovered that miR-24-3p regulated inflammation of highly aggressively proliferating immortalized (HAPI) cells by targeting MK2.In our study, we clarified that miR-24-3p repressed inflammation of microglia cells following SCI by regulating MK2, thereby providing promising biomarkers for SCI therapy.

The Role of Noncoding RNAs in Osteogenic Differentiation of Human Periodontal Ligament Stem Cells

Chronic inflammatory diseases, including periodontitis, are the most common causes of bone tissue destruction. Periodontitis often leads to loss of connective tissue homeostasis and reduced alveolar bone levels. Human periodontal ligament stem cells (PDLSCs), a population of multipotent stem cells derived from periodontal ligament tissues, are considered as candidate cells for the regeneration of alveolar bone and periodontal tissues. Periodontitis impairs the osteogenic differentiation of human PDLSCs. Noncoding RNAs (ncRNAs), including long noncoding RNA (lncRNA), microRNA (miRNA), and circular RNA (circRNA), have been proposed as vital regulators influencing several differentiation processes including bone regeneration. Still, the molecular mechanisms of ncRNAs regulating osteogenic differentiation of human PDLSCs remain poorly understood. Exploring the influence of ncRNAs in the process of osteogenic differentiation of human PDLSCs may provide novel therapeutic strategies for tissue regeneration as the regeneration of the lost periodontium is the ultimate goal of periodontal therapy.

Overview of noncoding RNAs involved in the osteogenic differentiation of periodontal ligament stem cells

Periodontal diseases are infectious diseases that are characterized by progressive damage to dental support tissue. The major goal of periodontal therapy is to regenerate the periodontium destroyed by periodontal diseases. Human periodontal ligament (PDL) tissue possesses periodontal regenerative properties, and periodontal ligament stem cells (PDLSCs) with the capacity for osteogenic differentiation show strong potential in clinical application for periodontium repair and regeneration. Noncoding RNAs (ncRNAs), which include a substantial portion of poly-A tail mature RNAs, are considered “transcriptional noise.” Recent studies show that ncRNAs play a major role in PDLSC differentiation; therefore, exploring how ncRNAs participate in the osteogenic differentiation of PDLSCs may help to elucidate the underlying mechanism of the osteogenic differentiation of PDLSCs and further shed light on the potential of stem cell transplantation for periodontium regeneration. In this review paper, we discuss the history of PDLSC research and highlight the regulatory mechanism of ncRNAs in the osteogenic differentiation of PDLSCs.

Long non-coding RNA FER1L4 promotes osteogenic differentiation of human periodontal ligament stromal cells via miR-874-3p and vascular endothelial growth factor A

Background

Periodontal ligament stromal cells (PDLSCs) are ideal cell sources for periodontal tissue repair and regeneration, but little is known about what determines their osteogenic capacity. Long non-coding RNAs (lncRNAs) are important regulatory molecules at both transcriptional and post-transcriptional levels. However, their roles in the osteogenic differentiation of PDLSCs are still largely unknown.

Methods

The expression of lncRNA Fer-1-like family member 4 (FER1L4) during the osteogenic differentiation of PDLSCs was detected by quantitative reverse transcription polymerase chain reaction. Overexpression or knockdown of FER1L4 was used to confirm its regulation of osteogenesis in PDLSCs. Alkaline phosphatase and Alizarin red S staining were used to detect mineral deposition. Dual luciferase reporter assays were used to analyze the binding of miR-874-3p to FER1L4 and vascular endothelial growth factor A (VEGFA). Bone regeneration in critical-sized calvarial defects was assessed in nude mice. New bone formation was analyzed by micro-CT, hematoxylin and eosin staining, Masson’s trichrome staining, and immunohistochemical analyses.

Results

FER1L4 levels increased gradually during consecutive osteogenic induction of PDLSCs. Overexpression of FER1L4 promoted the osteogenic differentiation of PDLSCs, as revealed by alkaline phosphatase activity, Alizarin red S staining, and the expression of osteogenic markers, whereas FER1L4 knockdown inhibited these processes. Subsequently, we identified a predicted binding site for miR-874-3p on FER1L4 and confirmed a direct interaction between them. Wild-type FER1L4 reporter activity was significantly inhibited by miR-874-3p, whereas mutant FER1L4 reporter was not affected. MiR-874-3p inhibited osteogenic differentiation and reversed the promotion of osteogenesis in PDLSCs by FER1L4. Moreover, miR-874-3p targeted VEGFA, a crucial gene in osteogenic differentiation, whereas FER1L4 upregulated the expression of VEGFA. In vivo, overexpression of FER1L4 led to more bone formation compared to the control group, as demonstrated by micro-CT and the histologic analyses.

Conclusion

FER1L4 positively regulates the osteogenic differentiation of PDLSCs via miR-874-3p and VEGFA. Our study provides a promising target for enhancing the osteogenic potential of PDLSCs and periodontal regeneration.

MicroRNA-24-3p regulates neuronal differentiation by controlling hippocalcin expression

Hippocalcin (HPCA) is a neuron-specific calcium-binding protein predominantly expressed in the nervous system. In the present study, we demonstrate that HPCA regulates neuronal differentiation in SH-SY5Y cells. We observed that the expression level of HPCA was increased during neuronal differentiation. Depletion of HPCA inhibited both neurite outgrowth and synaptophysin (SYP) expression, whereas overexpression of HPCA enhanced neuronal differentiation. Interestingly, we also found that the expression of HPCA mRNA was modulated by miR-24-3p. Using a dual-luciferase assay, we showed that co-transfection of a plasmid containing the miR-24-3p binding site from the 3'-untranslated region (3'UTR) of the HPCA gene and an miR-24-3p mimic effectively reduced luminescence activity. This effect was abolished when miR-24-3p seed sequences in the 3'UTR of the HPCA gene were mutated. miR-24-3p expression was decreased during differentiation, suggesting that the decreased expression level of miR-24-3p might have upregulated mRNA expression of HPCA. As expected, upregulation of miR-24-3p by an miRNA mimic led to reduced HPCA expression, accompanied by diminished neuronal differentiation. In contrast, downregulation of miR-24-3p by an antisense inhibitor promoted neurite outgrowth as well as levels of SYP expression. Taken together, these results suggest that miR-24-3p is an important miRNA that regulates neuronal differentiation by controlling HPCA expression.

Bta-miR-24-3p Controls the Myogenic Differentiation and Proliferation of Fetal, Bovine, Skeletal Muscle-Derived Progenitor Cells by Targeting ACVR1B

Simple Summary

MicroRNAs play pivotal roles in skeletal muscle development, but the molecular basis of their functions in fetal bovine skeletal muscle development is largely unknown. Here, we report a mechanistic study of bta-miR-24-3p, a key miRNA regulator of the myogenic differentiation of fetal bovine platelet-derived growth factor receptor alpha negative (PDGFRα^-) progenitor cells. We isolated progenitor cells from the bovine fetal longissimus dorsi muscle and purified them with PDGFRα antibodies to remove fibro-adipogenic progenitors. We observed elevated bta-miR-24-3p expression during differentiation, and bta-miR-24-3p overexpression led to promoted myogenic differentiation but suppressed proliferation. Moreover, activin receptor type 1B (ACVR1B) was identified as a direct target of bta-miR-24-3p, and ACVR1B-silencing cells exhibited similar phenotypes to bta-miR-24-3p-overexpressing bovine PDGFRα^- progenitor cells. These results extended our understanding on the roles of miRNA in fetal muscle development. The method of removing fibro-adipogenic progenitors in our study will also provide useful information for other investigators.

Abstract

MicroRNAs modulate a variety of cellular events, including skeletal muscle development, but the molecular basis of their functions in fetal bovine skeletal muscle development is poorly understood. In this study, we report that bta-miR-24-3p promotes the myogenic differentiation of fetal bovine PDGFRα^- progenitor cells. The expression of bta-miR-24-3p increased during myogenic differentiation. Overexpression of bta-miR-24-3p significantly promoted myogenic differentiation, but inhibited proliferation. A dual-luciferase assay identified ACVR1B as a direct target of bta-miR-24-3p. Similarly, knocking down ACVR1B by RNA interference also significantly inhibited proliferation and promoted the differentiation of bovine PDGFRα^- progenitor cells. Thus, our study provides a mechanism in which bta-miR-24-3p regulates myogenesis by inhibiting ACVR1B expression.