MicroRNA-224 impairs adipogenic differentiation of bovine preadipocytes by targeting LPL

Integrated Transcriptomic Analysis of Liver and Muscle Tissues Reveals Candidate Genes and Pathways Regulating Intramuscular Fat Deposition in Beef Cattle

Intramuscular fat (IMF) content in beef cattle is a critical determinant of beef meat quality, as it positively influences juiciness, tenderness, and palatability. In China, the crossbreeding of Wagyu and Angus is a prevalent method for achieving a better marbling level. However, the molecular mechanisms governing IMF regulation in these crossbreeds remain poorly understood. To elucidate the mechanism of IMF deposition in these crossbred cattle, we conducted a comparative transcriptomic analysis of longissimus dorsi muscles and livers from cattle with divergent IMF content. RNA-seq revealed 940 and 429 differentially expressed genes (DEGs) in the liver and muscle, respectively, with 60 genes co-differentially expressed (co-DEGs) in both tissues. Functional enrichment highlighted lipid metabolism pathways including fatty acid β-oxidation, PPAR signaling, and glycerolipid metabolism. A total of eleven genes including ACAA2, ACADL, ACOX2, CPT1B, CPT2, LPL, SLC27A1, ACAT1, GK, ACOX3, and ACSM5, were screened as key candidate genes for IMF deposition. A "liver-muscle" regulatory network of IMF deposition was built to illustrate the tissues' interaction. The reliability of the transcriptomic data was verified by quantitative reverse real-time PCR (qRT-PCR). Our findings provide novel molecular markers for increasing the IMF content and accelerating the genetic improvement of beef quality traits in crossbred cattle.

bta-miR-224 regulates milk fat metabolism by targeting FABP4 in bovine mammary epithelial cells

Milk fat is produced and secreted by the mammary gland, which is mainly regulated by diet and gene-molecule network. Therefore, understanding the molecular mechanism of milk fat synthesis is of practical significance for improving milk quality. Fatty acid-binding protein 4 (FABP4) is a candidate messenger RNA (mRNA) closely linked to milk fat metabolism obtained from transcriptomic analysis of mammary epithelial cells of cows in the pre-existing high- and low-milk-fat groups, and its expression pattern and function are still unclear. The qRT-PCR results depicted that FABP4 was highly expressed in bovine mammary epithelial cells (BMECs) in breast tissues and the high milk fat group. Subsequently, the regulatory effects of FABP4 on BMECs were analyzed by CCK8, EdU, and flow cytometry, and the results demonstrated that FABP4 inhibited the proliferation and viability of BMECs and promoted their apoptosis. Next, the effect of FABP4 on milk lipid metabolism was explored. pEGFP-N1-FABP4 was transfected into BMECs, and FABP4 upregulated the expression levels of the milk lipid marker genes XDH, PPARG, and ACSS2, and promoted the formation of triglycerides (TGs), cholesterol, lipid droplets, and β-casein. Strong interactions between FABP4 and PPARG were identified using STRING prediction. Western blotting revealed that FABP4 interacted with PPARG to promote PPARG expression, while the opposite result was observed after interfering with FABP4. The gene regulation of microRNA (miRNA) is essential for fatty acid metabolism and synthesis. Predicted by website and combined with pre-miRNA transcriptome sequencing results, we hypothesized that FABP4 might be the target gene of bta-miR-224. The results of the dual-luciferase reporter gene and qRT-PCR revealed that bta-miR-224 negatively regulated FABP4 expression by targeting the 3'-UTR of FABP4. By exploring the function of bta-miR-224, we observed that bta-miR-224 mimics downregulated the expression of the milk fat marker genes AGPAT6, ACSS2, and XDH and inhibited TG synthesis and lipid droplet secretion. However, the bta-miR-224 inhibitor depicted the opposite results. In conclusion, FABP4 plays a crucial role in regulating BMEC proliferation and differentiation. Bta-miR-224 targeting FABP4 may promote biological processes such as TG synthesis and lipid droplet formation through PPARG, which lays a solid foundation for further analysis of the functional mechanism of milk lipid metabolism in dairy cows from a miRNA-mRNA perspective.

SNPs in microRNA seed region and impact of miR-375 in concurrent regulation of multiple lipid accumulation-related genes

Bovine intramuscular fat (IMF), commonly referred to as marbling, is regulated by lipid metabolism, which includes adipogenesis, lipogenesis, glycerolipid synthesis, and lipolysis. In recent years, breeding researchers have identified single nucleotide polymorphisms (SNPs) as useful marker-assisted selection tools for improving marbling scores in national breeding programs. These included causal SNPs that induce phenotypic variation. MicroRNAs (miRNAs) are small highly conserved non-coding RNA molecules that bind to multiple non-coding regions. They are involved in post-transcriptional regulation. Multiple miRNAs may regulate a given target. Previously, three SNPs in the GPAM 3' UTR and four miRNAs were identified through in silico assays. The aim of this study is to verify the binding ability of the four miRNAs to the SNPs within the 3'UTR of GPAM, and to identify the regulatory function of miR-375 in the expression of genes related to lipid metabolism in mammalian adipocytes. It was verified that the four miRNAs bind to the GPAM 3'UTR, and identified that the miR-375 sequence is highly conserved. Furthermore, it was founded that miR-375 upregulated the GPAM gene, C/EBPα, PPARγ and lipid metabolism-related genes and promoted lipid droplet accumulation in 3T3-L1 cells. In conclusion, these results suggest that miR-375 is a multifunctional regulator of multiple lipid metabolism-related genes and may aid in obesity research as a biomarker.

Functional analysis of differentially expressed circular RNAs in sheep subcutaneous fat

BACKGROUND

Circular RNAs (circRNAs), as important non-coding RNAs (ncRNAs), are involved in many biological activities. However, the exact chemical mechanism behind fat accumulation is unknown. In this paper, we obtained the expression profiles of circRNAs using high-throughput sequencing and investigated their differential expression in subcutaneous fat tissue of Duolang and Small Tail Han sheep.

RESULTS

From the transcriptomic analysis, 141 differentially expressed circRNAs were identified, comprising 61 up-regulated circRNAs and 80 down-regulated circRNAs. These host genes were primarily enriched in the MAPK and AMPK signaling pathways which is closely associated with fat deposition regulation. We identified circRNA812, circRNA91, and circRNA388 as vital genes in fat deposition by miRNA-circRNA target gene prediction. The functional annotation results of target genes of key circRNAs showed that the signaling pathways mainly included PI3K-Akt and AMPK. We constructed the competing endogenous RNA (ceRNA) regulatory network to study the role of circRNAs in sheep lipid deposition, and circRNA812, circRNA91, and circRNA388 can adsorb more miRNAs. NC_040253.1_5757, as the source of miRNA response element (MRE) among the three, may play an important role during the process of sheep fat deposition.

CONCLUSIONS

Our study gives a systematic examination of the circRNA profiles expressed in sheep subcutaneous fat. These results from this study provide some new basis for understanding circRNA function and sheep fat metabolism.

CircADAMTS16 Inhibits Differentiation and Promotes Proliferation of Bovine Adipocytes by Targeting miR-10167-3p

Circular RNAs (CircRNAs) are covalently closed-loop non-coding RNA (ncRNA) molecules present in eukaryotes. Numerous studies have demonstrated that circRNAs are important regulators of bovine fat deposition, but their precise mechanisms remain unclear. Previous transcriptome sequencing studies have indicated that circADAMTS16, a circRNA derived from the a disintegrin-like metalloproteinases with the thrombospondin motif 16 (ADAMTS16) gene, is high expressed in bovine adipose tissue. This gives a hint that the circRNA may be involved in the process of bovine lipid metabolism. In this study, the targeting relationship between circADAMTS16 and miR-10167-3p was verified using a dual-luciferase reporter assay. Then, the functions of circADAMTS16 and miR-10167-3p in bovine adipocytes were explored through gain-of-function and lose-of-function. The mRNA expression levels of genes were detected by real-time quantitative PCR (qPCR), and lipid droplet formation was phenotypically evaluated by Oil Red O staining. Cell proliferation and apoptosis were detected using CCK-8, EdU, and flow cytometry. We demonstrated that circADAMTS16 targeted binding to miR-10167-3p. The up-regulation of circADAMTS16 inhibited the differentiation of bovine preadipocytes, and the overexpression of miR-10167-3p promoted the differentiation of bovine preadipocytes. Meanwhile, CCK-8 and EdU results indicated that circADAMTS16 promoted adipocyte proliferation. Subsequently, flow cytometry analysis showed that circADAMTS16 promoted cell transition from G0/G1 phase to S phase, and inhibited cell apoptosis. However, up-regulation of miR-10167-3p inhibited cell proliferation and promoted apoptosis. Briefly, circADAMTS16 inhibited the differentiation and promotes the proliferation of bovine adipocytes by targeting miR-10167-3p during bovine fat deposition, which provides new insights into the mechanism of circRNAs regulation of beef quality.

MiRNA-Seq reveals key MicroRNAs involved in fat metabolism of sheep liver

There is a genetic difference between Hu sheep (short/fat-tailed sheep) and Tibetan sheep (short/thin-tailed sheep) in tail type, because of fat metabolism. Previous studies have mainly focused directly on sheep tail fat, which is not the main organ of fat metabolism. The function of miRNAs in sheep liver fat metabolism has not been thoroughly elucidated. In this study, miRNA-Seq was used to identify miRNAs in the liver tissue of three Hu sheep (short/fat-tailed sheep) and three Tibetan sheep (short/thin-tailed sheep) to characterize the differences in fat metabolism of sheep. In our study, Hu sheep was in a control group, we identified 11 differentially expressed miRNAs (DE miRNAs), including six up-regulated miRNAs and five down-regulated miRNAs. Miranda and RNAhybrid were used to predict the target genes of DE miRNAs, obtaining 3,404 target genes. A total of 115 and 67 GO terms as well as 54 and 5 KEGG pathways were significantly (padj < 0.05) enriched for predicted 3,109 target genes of up-regulated and 295 target genes of down-regulated miRNAs, respectively. oar-miR-432 was one of the most up-regulated miRNAs between Hu sheep and Tibetan sheep. And SIRT1 is one of the potential target genes of oar-miR-432. Furthermore, functional validation using the dual-luciferase reporter assay indicated that the up-regulated miRNA; oar-miR-432 potentially targeted sirtuin 1 (SIRT1) expression. Then, the oar-miR-432 mimic transfected into preadipocytes resulted in inhibited expression of SIRT1. This is the first time reported that the expression of SIRT1 gene was regulated by oar-miR-432 in fat metabolism of sheep liver. These results could provide a meaningful theoretical basis for studying the fat metabolism of sheep.

Genome-Wide Analysis of microRNAs Identifies the Lipid Metabolism Pathway to Be a Defining Factor in Adipose Tissue From Different Sheep

microRNAs are a class of important non-coding RNAs, which can participate in the regulation of biological processes. In recent years, miRNA has been widely studied not only in humans and mice, but also in animal husbandry. However, compared with other livestock and poultry breeds, the study of miRNA in subcutaneous adipose tissue of sheep is not comprehensive. Transcriptome analysis of miRNAs in subcutaneous adipose tissue of Duolang sheep, and Small Tail Han sheep was performed using RNA-Seq technology. Differentially expressed miRNAs were screened between different breeds. Target genes were predicted, and then the joint analysis of candidate genes were conducted based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. Finally, the RNA-Seq data were verified by real-time quantitative polymerase chain reaction (qRT-PCR). Herein, we identified 38 differentially expressed miRNAs (9 novel miRNAs and 29 known miRNAs). In addition, a total of 854 target genes were predicted by miRanda software. GO and KEGG pathway analysis demonstrated that regulation of lipolysis in adipocytes plays a key role in the deposition of subcutaneous adipose tissue in Duolang sheep and Small Tail Han sheep. The miRNAs might regulate fat deposits by regulating genes involved in regulation of lipolysis in adipocytes. Specifically, NC_ 040278.1_ 37602, oar-mir-493-3p, NC_ 040278.1_ 37521 and NC_ 040255.1_ 11627 might target PTGS2, AKT2, AKT3, and PIK3CA, respectively, and then play critical regulatory role. In conclusion, all the results provide a good idea for further revealing the mechanism of subcutaneous adipose tissue deposition and improving the meat production performance of sheep, and lay a foundation for promoting the development of animal husbandry.

Genetic regulation and variation of expression of miRNA and mRNA transcripts in fetal muscle tissue in the context of sex, dam and variable fetal weight

BACKGROUND

Impaired skeletal muscle growth in utero can result in reduced birth weight and pathogenesis of intrauterine growth restriction. Fetal and placental growth is influenced by many factors including genetic, epigenetic and environmental factors. In fact, the sex and genotype of the fetus itself, as well as the mother providing it with a suitable environment, influence the growth of the fetus. Hence, our goal was to decipher and elucidate the molecular pathways of developmental processes mediated by miRNAs and mRNAs in fetal muscle tissue in the context of sex, dam, and fetal weight. Therefore, we analyse the variation of miRNA and mRNA expression in relation to these factors. In addition, the coincidence of genetic regulation of these mRNAs and miRNAs, as revealed by expression quantitative trait loci (eQTL) analyses, with sex-, mother- and weight-associated expression was investigated.

METHODS

A three-generation pig F2 population (n = 118) based on reciprocal crossing of German Landrace (DL) and Pietrain (Pi) was used. Genotype information and transcriptomic data (mRNA and miRNA) from longissimus dorsi muscle (LDM) of pig fetuses sampled at 63 days post-conception (dpc) were used for eQTL analyses.

RESULTS

The transcript abundances of 13, 853, and 275 probe-sets were influenced by sex, dam and fetal weight at 63 dpc, respectively (FDR < 5%). Most of significant transcripts affected by sex were located on the sex chromosomes including KDM6A and ANOS1 or autosomes including ANKS1B, LOC100155138 and miR-153. The fetal muscle transcripts associated with fetal weight indicated clearer metabolic directions than maternally influenced fetal muscle transcripts. Moreover, coincidence of genetic regulation (eQTL) and variation in transcript abundance due to sex, dam and fetal weight were identified.

CONCLUSIONS

Integrating information on eQTL, sex-, dam- and weight-associated differential expression and QTL for fetal weight allowed us to identify molecular pathways and shed light on the basic biological processes associated with differential muscle development in males and females, with implications for adaptive fetal programming.

Integrated Analysis of the ceRNA Network and M-7474 Function in Testosterone-Mediated Fat Deposition in Pigs

Castration can significantly enhance fat deposition in pigs, and the molecular mechanism of fat deposition caused by castration and its influence on fat deposition in different parts of pigs remain unclear. RNA-seq was performed on adipose tissue from different parts of castrated and intact Yorkshire pigs. Different ceRNA networks were constructed for different fat parts. GO and KEGG pathway annotations suggested that testosterone elevates cell migration and affects differentiation and apoptosis in back fat, while it predisposes animals to glycolipid metabolism disorders and increases the expression of inflammatory cytokines in abdominal fat. The interaction between M-7474, novel_miR_243 and SGK1 was verified by dual fluorescence experiments. This ceRNA relationship has also been demonstrated in porcine preadipocytes. Overexpression of M-7474 significantly inhibited the differentiation of preadipocytes compared to the control group. When 100 nM testosterone was added during preadipocyte differentiation, the expression of M-7474 was increased, and preadipocyte differentiation was significantly inhibited. Testosterone can affect preadipocyte differentiation by upregulating the expression of M-7474, sponging novel-miR-243, and regulating the expression of genes such as SGK1. At the same time, HSD11B1 and SLC2A4 may also be regulated by the corresponding lncRNA and miRNA, which ultimately affects glucose uptake by adipocytes and leads to obesity.

miR-302b promotes bovine preadipocyte differentiation and inhibits proliferation by targeting CDK2

MicroRNAs have been recently reported to act as key regulators of adipogenesis, a multifactorial complex process. One miRNA, miR-302b, is an important regulator of cell proliferation and differentiation and controls cancer development, but we speculate that miR-302b may also regulate bovine adipogenesis. Herein we have evaluated the role of this miRNA in bovine adipocyte differentiation using quantitative Real-Time Polymerase Chain Reaction (qRT-PCR), Oil Red O staining, a dual-luciferase reporter. CDK2 was identified as the target gene of miR-302b, and miR-302b agomir promoted mRNA and protein expression levels of adipocyte-specific genes. In addition, a CCK-8 kit was used to show that miR-302b agomir, but not the negative control, inhibits preadipocyte proliferation. In conclusion, miR-302b promotes bovine preadipocyte differentiation and inhibits proliferation by targeting CDK2.

Transcriptome analysis of miRNAs during myoblasts adipogenic differentiation

Intramuscular fat content is closely related to meat quality traits and has high heritability. miRNAs are a class of small non-coding RNA, which are highly conserved in animals and play important regulatory roles in adipogenesis. Therefore, they can be used as molecular markers for meat quality traits. Herein, we used in vitro model of myoblasts adipogenic differentiation to screen differential miRNAs by RNA-seq. A total of 71 differentially miRNAs were filtered, including 31 up-regulated miRNAs and 40 down-regulated miRNAs. Since, we selected 18 miRNAs for RT-qPCR validation, including some miRNAs likely miR-146a-5p, miR-210-3p, miR-199a, miR-224, and miR-214-3p that play important regulatory roles in adipogenesis. In addition, functional enrichment analysis results revealed that members of miRNA target genes were enriched into insulin signaling pathway and MAPK signaling pathway, which are closely related to adipogenesis. Taken together, these data will contribute to further investigate the function of miRNAs in intramuscular fat deposition. These differentially miRNAs can be developed as biomarkers for animal breeding.

Human amniotic mesenchymal stem cells combined with PPCNg facilitate injured endometrial regeneration

BACKGROUND

Caused by the injury to the endometrial basal layer, intrauterine adhesions (IUA) are characterized by uterine cavity obliteration, leading to impaired fertility. Human amniotic mesenchymal stem cells (hAMSCs) have the potential to promote endometrial regeneration mainly through paracrine ability. PPCNg is a thermoresponsive biomaterial consisted of Poly (polyethylene glycol citrate-co-N-isopropylacrylamide) (PPCN) mixed with gelatin, which has been reported as a scaffold for stem cell transplantation. This study aims to investigate the therapeutic effect of hAMSCs combined with PPCNg transplantation in promoting the regeneration of injured endometrium.

METHODS

hAMSCs were cultured in different concentrates of PPCNg in vitro, and their proliferation, apoptosis and cell cycle were examined by CCK-8 assay and flow cytometry. Immunofluorescence was used to determine the MSCs specific surface markers. The expression of pluripotent genes was analyzed by qRT-PCR. The multiple-lineage differentiation potential was further evaluated by detecting the differentiation-related genes using qRT-PCR and specific staining. The Sprague-Dawley (SD) rat IUA model was established with 95% ethanol. hAMSCs combined with PPCNg were transplanted through intrauterine injection. The retention of DiR-labeled hAMSCs was observed by vivo fluorescence imaging. The endometrium morphology was assessed using hematoxylin and eosin (H&E) and Masson staining. Immunohistochemistry staining was performed to detect biomarkers related to endometrial proliferation, re-epithelialization, angiogenesis and endometrial receptivity. The function of regenerated endometrium was evaluated by pregnancy tests.

RESULTS

hAMSCs maintained normal cell proliferation, apoptosis and cell cycle in PPCNg. Immunofluorescence and qRT-PCR showed that hAMSCs cultured in PPCNg and hAMSCs cultured alone expressed the same surface markers and pluripotent genes. hAMSCs exhibited normal multilineage differentiation potential in PPCNg. Vivo fluorescence imaging results revealed that the fluorescence intensity of hAMSCs combined with PPCNg intrauterine transplantation was stronger than that of direct hAMSCs intrauterine transplantation. Histological assays showed the increase in the thickness of endometrial and the number of endometrial glands, and the remarkably decrease in the fibrosis area in the PPCNg/hAMSCs group. The expressions of Ki-67, CK7, CK19, VEGF, ER and PR were significantly increased in the PPCNg/hAMSCs group. Moreover, the number of implanted embryos and pregnancy rate were significantly higher in the PPCNg/hAMSCs group than in the hAMSCs group.

CONCLUSIONS

PPCNg is suitable for growth, phenotype maintenance and multilineage differentiation of hAMSCs. hAMSCs combined with PPCNg intrauterine transplantation can facilitate the regeneration of injured endometrium by improving utilization rates of hAMSCs, and eventually restore reproductive capacity.

Licochalcone A activation of glycolysis pathway has an anti-aging effect on human adipose stem cells

Licochalcone A (LA) is a chalcone flavonoid of Glycyrrhiza inflata, which has anti-cancer, antioxidant, anti-inflammatory, and neuroprotective effects. However, no anti-aging benefits of LA have been demonstrated in vitro or in vivo. In this study, we explored whether LA has an anti-aging effect in adipose-derived stem cells (ADSCs). We performed β-galactosidase staining and measured reactive oxygen species, relative telomere lengths, and P16^ink4a mRNA expression. Osteogenesis was assessed by Alizarin Red staining and adipogenesis by was assessed Oil Red O staining. Protein levels of related markers runt-related transcription factor 2 and lipoprotein lipase were also examined. RNA sequencing and measurement of glycolysis activities showed that LA significantly activated glycolysis in ADSCs. Together, our data strongly suggest that the LA have an anti-aging effect through activate the glycolysis pathway.

Bta-miR-2400 Targets SUMO1 to Affect Yak Preadipocytes Proliferation and Differentiation

Yak adipose tissue may have evolved a unique energy metabolism manner to accommodate the organism's seasonal growth rhythms. MiRNAs regulate multiple biological processes including systemic metabolism and energy homeostasis through post-transcriptional regulations. Rare reports have shown that miRNAs regulate lipid metabolism in domestic yaks. Therefore, we investigated the regulatory mechanisms of bta-miR-2400 in modulating yak preadipocytes proliferation and differentiation. We found that bta-miR-2400 was highly expressed in adipose tissue. Overexpression of bta-miR-2400 in yak preadipocytes significantly enhanced cell proliferation, increased the number of EdU fluorescence-stained cells, and promoted the expression of proliferation marker genes (CDK2, CDK4 and PCNA). Besides, overexpression of bta-miR-2400 repressed the expression of adipogenesis-related marker genes, and the content of cellular triglyceride was substantially reduced. Conversely, inhibition of bta-miR-2400 showed opposite effects compared to those of bta-miR-2400 overexpression in yak preadipocytes. Further, luciferase reporter assays revealed that SUMO1 is a target gene of bta-miR-2400, with bta-miR-2400 being able to down-regulate SUMO1 mRNA and protein expression. In conclusion, bta-miR-2400 regulates lipid metabolism and energy homeostasis in yak preadipocytes by directly targeting SUMO1 to promote cell proliferation and inhibit differentiation.

Mechanisms linking endoplasmic reticulum (ER) stress and microRNAs to adipose tissue dysfunction in obesity

Over accumulation of lipids in adipose tissue disrupts metabolic homeostasis by affecting cellular processes. Endoplasmic reticulum (ER) stress is one such process affected by obesity. Biochemical and physiological alterations in adipose tissue due to obesity interfere with adipose ER functions causing ER stress. This is in line with increased irregularities in other cellular processes such as inflammation and autophagy, affecting overall metabolic integrity within adipocytes. Additionally, microRNAs (miRNAs), which can post-transcriptionally regulate genes, are differentially modulated in obesity. A better understanding and identification of such miRNAs could be used as novel therapeutic targets to fight against diseases. In this review, we discuss ways in which ER stress participates as a common molecular process in the pathogenesis of obesity-associated metabolic disorders. Moreover, our review discusses detailed underlying mechanisms through which ER stress and miRNAs contribute to metabolic alteration in adipose tissue in obesity. Hence, identifying mechanistic involvement of miRNAs-ER stress cross-talk in regulating adipose function during obesity could be used as a potential therapeutic approach to combat chronic diseases, including obesity.

Reciprocal effect of microRNA-224 on osteogenesis and adipogenesis in steroid-induced osteonecrosis of the femoral head

The adverse effects of glucocorticoids (GCs) on bone marrow stromal stem cells (BMSCs) play an important role in steroid-induced osteonecrosis of the femoral head (ONFH). Our previous miRNA microarray analysis indicated that microRNA-224-5p (miR-224-5p) could be a potential regulator; however, the underlying mechanism remains unclear. In the present study, we demonstrated that miR-224-5p was upregulated in GC-treated BMSCs, and functional experiments revealed that miR-224-5p could suppress osteogenic but promote adipogenic differentiation of BMSCs. Smad4 was identified as a direct target gene of miR-224-5p, and the Smad4-Taz axis was confirmed as the regulatory pathway for adipo-osteogenic differentiation of BMSCs. Our in vivo experiments further confirmed that the miR-224-5p antagomir could alleviate the inhibitory effects of GCs and facilitate bone formation in steroid-induced ONFH models. Therefore, these findings provide insight into the function of miR-224-5p as a reciprocal regulator of the adipo-osteogenic differentiation of BMSCs, and it could serve as a novel therapeutic target for steroid-induced ONFH.

ncRNAs regulate bovine adipose tissue deposition

Lipid metabolism, which encompasses synthesis and degradation of lipids, is critical for a wide range of cellular functions, including structural and morphological properties of organelles, energy storage, signalling, and the stability and function of membrane proteins. Adipose tissue is a dynamic tissue type that performs a lot of significant physiological functions, including secretion, and is involved in maintaining homeostasis and in regulatory roles of other tissues based on paracrine or endocrine. More recently, several classes of non-coding RNAs (ncRNAs), such as long non-coding RNA (lncRNA), microRNA (miRNA) and circular RNA (circRNA), have been discovered in adipocytes, and they act as critical regulators of gene expression in adipogenesis and regulate adipogenesis through multiple pathways. In the present paper, we discussed several classes of non-coding RNAs and summarized the latest research on the regulatory role of ncRNAs in bovine adipogenesis. We gave examples for known modes of action to look forward to providing reference information future scientific research in cattle breeding.

Identification of Candidate Circular RNAs Underlying Intramuscular Fat Content in the Donkey

Intramuscular fat (IMF) content is a crucial indicator of meat quality. Circular RNAs (circRNAs) are a large class of endogenous RNAs that are involved in many physiological processes. However, the expression and function of circRNA in IMF in the donkey remains unresolved. Here we performed an expression profiling of circRNAs in the donkey longissimus dorsi muscle and identified 12,727 candidate circRNAs. Among these, 70% were derived from the exons of protein genes. Furthermore, a total of 127 differentially expressed (DE) circRNAs were identified in high (H) and low (L) IMF content groups, including 63 upregulated and 64 downregulated circRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the host genes of the DE circRNAs showed that the host genes were enriched in lipid metabolism related GO terms (e.g., fatty acid beta-oxidation using acyl-CoA dehydrogenase and MLL3/4 complex), and signaling pathways (e.g., TGF-beta and lysine degradation signaling pathway). Further analyses indicated that 127 DE circRNAs were predicted to potentially interact with miRNAs, leading to the construction of circRNA-miRNA regulatory network. Multiple circRNAs can potentially function as sponges of miRNAs that regulate the differentiation of adipocytes. Our results provide valuable expression profile information for circRNA in the donkey and new insight into the regulatory mechanisms of circRNAs in the regulation of IMF content.

Sex-specific microRNAs in women with diabetes and left ventricular diastolic dysfunction or HFpEF associate with microvascular injury

Left ventricular diastolic dysfunction (LVDD) and heart failure with preserved ejection fraction (HFpEF) are microcirculation defects following diabetes mellitus (DM). Unrecognized HFpEF is more prevalent in women with diabetes compared to men with diabetes and therefore sex-specific diagnostic strategies are needed. Previously, we demonstrated altered plasma miRs in DM patients with microvascular injury [defined by elevated plasma Angiopoietin-2 (Ang-2) levels]. This study hypothesized the presence of sex-differences in plasma miRs and Ang-2 in diabetic (female) patients with LVDD or HFpEF. After a pilot study, we assessed 16 plasma miRs in patients with LVDD (n = 122), controls (n = 244) and female diabetic patients (n = 10). Subsequently, among these miRs we selected and measured plasma miR-34a, -224 and -452 in diabetic HFpEF patients (n = 53) and controls (n = 52). In LVDD patients, miR-34a associated with Ang-2 levels (R² 0.04, R = 0.21, p = 0.001, 95% CI 0.103–0.312), with plasma levels being diminished in patients with DM, while women with an eGFR < 60 ml/min and LVDD had lower levels of miR-34a, -224 and -452 compared to women without an eGFR < 60 ml/min without LVDD. In diabetic HFpEF women (n = 28), plasma Ang-2 levels and the X-chromosome located miR-224/452 cluster increased compared to men. We conclude that plasma miR-34a, -224 and -452 display an association with the microvascular injury marker Ang-2 and are particularly targeted to women with LVDD or HFpEF.

The Role of MicroRNAs in Muscle Tissue Development in Beef Cattle

In this review, we highlight information on microRNA (miRNA) identification and functional characterization in the beef for muscle and carcass composition traits, with an emphasis on Qinchuan beef cattle, and discuss the current challenges and future directions for the use of miRNA as a biomarker in cattle for breeding programs to improve meat quality and carcass traits. MicroRNAs are endogenous and non-coding RNA that have the function of making post-transcriptional modifications during the process of preadipocyte differentiation in mammals. Many studies claim that diverse miRNAs have an impact on adipogenesis. Furthermore, their target genes are associated with every phase of adipocyte differentiation. It has been confirmed that, during adipogenesis, several miRNAs are differentially expressed, including miR-204, miR-224, and miR-33. The development of mammalian skeletal muscle is sequentially controlled by somite commitment into progenitor cells, followed by their fusion and migration, the proliferation of myoblasts, and final modification into fast- and slow-twitch muscle fibers. It has been reported that miRNA in the bovine MEG3-DIO3 locus has a regulatory function for myoblast differentiation. Likewise, miR-224 has been associated with controlling the differentiation of bovine adipocytes by targeting lipoprotein lipase. Through the posttranscriptional downregulation of KLF6, miR-148a-3p disrupts the proliferation of bovine myoblasts and stimulates apoptosis while the miR-23a~27a~24-2 cluster represses adipogenesis. Additional to influences on muscle and fat, bta-mir-182, bta-mir-183, and bta-mir-338 represent regulators of proteolysis in muscle, which influences meat tenderness.

HOXC10 promotes proliferation and attenuates lipid accumulation of sheep bone marrow mesenchymal stem cells

Homeodomain-containing gene C10 (HOXC10), known to regulate cell differentiation and proliferation, is a key negative regulator in the browning of white adipose tissue in mice. Sheep is an important farm animal that provides meat for human consumption, with fat content being an important meat quality determinant; however, there is no report about the role of HOXC10 in sheep adipocytes or adipogenesis. In this study, we investigated the effect of HOXC10 on proliferation and adipogenic differentiation in sheep bone marrow mesenchymal stem cells (sBMSCs). In sBMSCs, HOXC10 overexpression promoted cell proliferation and upregulated the expression of p-PI3K, p-AKT, p-p70S6K, p-MEK, and p-ERK, whereas HOXC10 knockdown was associated with the opposite effects. These results suggested that HOXC10 may promote cell proliferation by activating the MEK/ERK and PI3K/AKT/mTOR/p70S6K signaling pathways. In addition, we found that HOXC10 expression was negatively associated with lipid accumulation in adipogenic-differentiated sBMSCs. HOXC10 overexpression in sBMSCs significantly decreased lipid droplet accumulation and suppressed the expression of adipogenic-specific genes, including ACC, LPL, PPARG, and FABP4, while HOXC10 knockdown was associated with the opposite effects. Furthermore, our study suggested a new regulatory mechanism of the effect of HOXC10 on lipid accumulation and metabolism; HOXC10 may negatively regulate lipid accumulation in adipogenic-differentiated sBMSCs, at least in part, by suppressing LPL expression. Overall, our research not only contributes to a better understanding of the mechanism of lipid accumulation and metabolism in sheep, but also shed light on meat quality control in the future.