Interplay among miR-29 family, mineral metabolism, and gene regulation in Bos indicus muscle

MicroRNA-542-3p targets Pten to inhibit the myoblasts proliferation but suppresses myogenic differentiation independent of targeted Pten

BACKGROUND

Non-coding RNA is a key epigenetic regulation factor during skeletal muscle development and postnatal growth, and miR-542-3p was reported to be conserved and highly expressed in the skeletal muscle among different species. However, its exact functions in the proliferation of muscle stem cells and myogenesis remain to be determined.

METHODS

Transfection of proliferative and differentiated C2C12 cells used miR-542-3p mimic and inhibitor. RT-qPCR, EdU staining, immunofluorescence staining, cell counting kit 8 (CCK-8), and Western blot were used to evaluate the proliferation and myogenic differentiation caused by miR-542-3p. The dual luciferase reporter analysis and rescued experiment of the target gene were used to reveal the molecular mechanism.

RESULTS

The data shows overexpression of miR-542-3p downregulation of mRNA and protein levels of proliferation marker genes, reduction of EdU+ cells, and cellular vitality. Additionally, knocking it down promoted the aforementioned phenotypes. For differentiation, the miR-542-3p gain-of-function reduced both mRNA and protein levels of myogenic genes, including MYOG, MYOD1, et al. Furthermore, immunofluorescence staining immunized by MYHC antibody showed that the myotube number, fluorescence intensity, differentiation index, and myotube fusion index all decreased in the miR-542-3p mimic group, compared with the control group. Conversely, these phenotypes exhibited an increased trend in the miR-542-3p inhibitor group. Mechanistically, phosphatase and tensin homolog (Pten) was identified as the bona fide target gene of miR-542-3p by dual luciferase reporter gene assay, si-Pten combined with miR-542-3p inhibitor treatments totally rescued the promotion of proliferation by loss-function of miR-542-3p.

CONCLUSIONS

This study indicates that miR-542-3p inhibits the proliferation and differentiation of myoblast and Pten is a dependent target gene of miR-542-3p in myoblast proliferation, but not in differentiation.

A Study of FoxO1, mTOR, miR-21, miR-29b, and miR-98 Expression Levels Regarding Metabolic Syndrome in Acne Vulgaris Patients

BACKGROUND

Acne vulgaris (AV) is an inflammatory skin disease caused by the mechanistic target of rapamycin complex 1 (mTORC1). forkhead box protein (Fox) O1 is known to regulate the relationship between the mTORC1 signaling pathway and insulin resistance (IR). Increased mTORC1 signaling is known to predispose one to diseases such as insulin resistance (IR), obesity, and diabetes mellitus. One of the major components of mTORC1 is mTOR. FoxO1 and mTOR play key roles in the onset and progression of metabolic syndrome (MetS). In this study, we aimed to elucidate the relationship between AV and MetS through FoxO1 and mTOR signaling pathways and microRNAs (miRs) associated with these signaling pathways.

METHODS

We examined 20 AV patients without MetS, 16 AV patients with MetS, and 20 healthy controls. The demographic characteristics of the patients, MetS parameters, clinical severity of AV (Global Acne Grading System, GAGS), and the homeostasis model assessment (HOMA) values were compared between the groups. In addition, the expression levels of FoxO1 and mTOR genes, along with the expression levels of miR-21, miR-29b, and miR-98, were assessed in skin biopsy samples from all groups using real-time polymerase chain reaction methods. FoxO1, mTOR, and miRNA expression levels were recorded as fold change.

RESULTS

The mean age of patients with AV without MetS was statistically lower. In AV patients with MetS, those with moderate GAGS scores had statistically significantly higher HOMA values than those with mild GAGS scores. FoxO1 expression was significantly lower in AV patients compared to controls. The mTOR expression levels of AV patients with MetS were significantly higher than the other two groups. The expression levels of miR-21 and miR-29b were significantly increased in the group of AV patients with MetS compared to the group of AV patients without MetS.

CONCLUSIONS

These results suggested that the mTOR pathway may play an important role in explaining the relationship between AV and MetS in acne pathogenesis. They also suggested that miR-21 and miR-29b play a role in the inflammatory process of AV.

Multi-Omics Approach Reveals miR-SNPs Affecting Muscle Fatty Acids Profile in Nelore Cattle

MicroRNAs (miRNAs) are key regulators of gene expression, potentially affecting several biological processes, whose function can be altered by sequence variation. Hence, the integration of single nucleotide polymorphisms (SNP) and miRNAs can explain individual differences in economic traits. To provide new insights into the effects of SNPs on miRNAs and their related target genes, we carried out a multi-omic analysis to identify SNPs in miRNA mature sequences (miR-SNPs) associated with fatty acid (FA) composition in the Nelore cattle. As a result, we identified 3 miR-SNPs in different miRNAs (bta-miR-2419-3p, bta-miR-193a-2, and bta-miR-1291) significantly associated with FA traits (p-value < 0.02, Bonferroni corrected). Among these, the rs110817643C>T, located in the seed sequence of the bta-miR-1291, was associated with different ω6 FAs, polyunsaturated FA, and polyunsaturated:saturated FA ratios. Concerning the other two miR-SNPs, the rs43400521T>C (located in the bta-miR-2419-3p) was associated with C12:0 and C18:1 cis-11 FA, whereas the rs516857374A>G (located in the bta-miR-193a-2) was associated with C18:3 ω6 and ratio of ω6/ω3 traits. Additionally, to identify potential biomarkers for FA composition, we described target genes affected by these miR-SNPs at the mRNA or protein level. Our multi-omics analysis outlines the effects of genetic polymorphism on miRNA, and it highlights miR-SNPs and target candidate genes that control beef fatty acid composition.