Circular RNAs (circRNAs) have been identified from various tissues and species, but their regulatory functions during developmental processes are not well understood. We examined circRNA expression ...profiles of two developmental stages of bovine skeletal muscle (embryonic and adult musculus longissimus) to provide first insights into their potential involvement in bovine myogenesis. We identified 12 981 circRNAs and annotated them to the Bos taurus reference genome, including 530 circular intronic RNAs (ciRNAs). One parental gene could generate multiple circRNA isoforms, with only one or two isoforms being expressed at higher expression levels. Also, several host genes produced different isoforms when comparing development stages. Most circRNA candidates contained two to seven exons, and genomic distances to back-splicing sites were usually less than 50 kb. The length of upstream or downstream flanking introns was usually less than 105 nt (mean≈11 000 nt). Several circRNAs differed in abundance between developmental stages, and real-time quantitative PCR (qPCR) analysis largely confirmed differential expression of the 17 circRNAs included in this analysis. The second part of our study characterized the role of circLMO7-one of the most down-regulated circRNAs when comparing adult to embryonic muscle tissue-in bovine muscle development. Overexpression of circLMO7 inhibited the differentiation of primary bovine myoblasts, and it appears to function as a competing endogenous RNA for miR-378a-3p, whose involvement in bovine muscle development has been characterized beforehand. Congruent with our interpretation, circLMO7 increased the number of myoblasts in the S-phase of the cell cycle and decreased the proportion of cells in the G0/G1 phase. Moreover, it promoted the proliferation of myoblasts and protected them from apoptosis. Our study provides novel insights into the regulatory mechanisms underlying skeletal muscle development and identifies a number of circRNAs whose regulatory potential will need to be explored in the future.
Muscle fibers are generally formed as multinucleated fibers that are differentiated from myoblasts. Several reports have identified transcription factors and proteins involved in the process of ...muscle differentiation, but the roles of microRNAs (miRNAs) in myogenesis remain unclear. Here, comparative analysis of the miRNA expression profiles in mouse myoblasts and gastrocnemius (GA) muscle uncovered miR-3074-3p as a novel miRNA showing markedly reduced expression in fully differentiated adult skeletal muscle. Interestingly, elevating miR-3074-3p promoted myogenesis in C2C12 cells, primary myoblasts, and HSMMs, resulting in increased mRNA expression of myogenic makers such as Myog and MyHC. Using a target prediction program, we identified Caveolin-1 (Cav1) as a target mRNA of miR-3074-3p and verified that miR-3074-3p directly interacts with the 3’ untranslated region (UTR) of Cav1 mRNA. Consistent with the findings in miR-3074-3p-overexpressing myoblasts, knockdown of Cav1 promoted myogenesis in C2C12 cells and HSMMs. Taken together, our results suggest that miR-3074-3p acts a positive regulator of myogenic differentiation by targeting Cav1. BMB Reports 2020; 53(5): 278-283
The bone morphogenetic protein (BMP) gene family comprises a group of multifunctional cytokines that play important roles in limb development, bone formation, fat deposition, and reproductive traits ...of vertebrates. However, no systematic and comprehensive investigations of the various traits of the whole family members have been conducted, particularly in chickens. Here, we performed genome-wide screening and identified 14 BMP genes, which were classified into the BMP2/4, BMP5/6/7/8A, growth differentiation factor (GDF) 2/BMP10, GDF5/6/7, and GDF11/BMP3/15 subfamilies. Genetic variation pattern analysis showed that BMP genes were responsible for the artificial selection of commercial broilers and layers, with BMP2, BMP6, and GDF7 likely contributing significantly to the formation of both specialized meat- and egg-type lines, whereas BMP7 likely contributed more to the formation of meat-type lines. Genetic association analysis showed that single nucleotide polymorphisms (SNPs) in the BMP7 intron region were associated with body weight, breast muscle weight, leg weight, abdominal fat weights and contents of total cholesterol (T-CHO), triglyceride (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) in serum. Additionally, gain- and loss-of-function assays demonstrated that BMP7 promoted the proliferation, myogenic differentiation, and lipid droplet accumulation in myoblasts; enhanced lipid synthesis in hepatocytes; promoted the proliferation and inhibited adipogenic differentiation of intramuscular preadipocytes; and induced the proliferation and adipogenic differentiation of abdominal preadipocytes. These results provide novel insights into the role of BMP genes in chicken growth, reproductive regulation, and lipid deposition and could be used to develop genetic markers for breeding selection in chickens.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Duck meat is pivotal in providing high-quality protein for human nutrition, underscoring the importance of studying duck myogenesis. The regulatory mechanisms governing duck myogenesis involve both ...coding and non-coding RNAs, yet their specific expression patterns and molecular mechanisms remain elusive. To address this knowledge gap, we performed expression profiling analyses of mRNAs, lncRNAs, circRNAs, and miRNAs involved in duck myogenesis using whole-transcriptome RNA-seq. Our analysis identified 1733 differentially expressed (DE)-mRNAs, 1116 DE-lncRNAs, 54 DE-circRNAs, and 174 DE-miRNAs when comparing myoblasts and myotubes. A GO analysis highlighted the enrichment of DE molecules in the extracellular region, protein binding, and exocyst. A KEGG analysis pinpointed pathways related to ferroptosis, PPAR signaling, nitrogen metabolism, cell cycle, cardiac muscle contraction, glycerolipid metabolism, and actin cytoskeleton. A total of 51 trans-acting lncRNAs, including ENSAPLT00020002101 and ENSAPLT00020012069, were predicted to participate in regulating myoblast proliferation and differentiation. Based on the ceRNAs, we constructed lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA ceRNA networks involving five miRNAs (miR-129-5p, miR-133a-5p, miR-22-3p, miR-27b-3p, and let-7b-5p) that are relevant to myogenesis. Furthermore, the GO and KEGG analyses of the DE-mRNAs within the ceRNA network underscored the significant enrichment of the glycerolipid metabolism pathway. We identified five different DE-mRNAs, specifically ENSAPLG00020001677, ENSAPLG00020002183, ENSAPLG00020005019, ENSAPLG00020010497, and ENSAPLG00020017682, as potential target genes that are crucial for myogenesis in the context of glycerolipid metabolism. These five mRNAs are integral to ceRNA networks, with miR-107_R-2 and miR-1260 emerging as key regulators. In summary, this study provides a valuable resource elucidating the intricate interplay of mRNA-lncRNA-circRNA-miRNA in duck myogenesis, shedding light on the molecular mechanisms that govern this critical biological process.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Muscle stem cells, termed satellite cells, are crucial for skeletal muscle growth and regeneration. In healthy adult muscle, satellite cells are quiescent but poised for activation. During muscle ...regeneration, activated satellite cells transiently re-enter the cell cycle to proliferate and subsequently exit the cell cycle to differentiate or self-renew. Recent studies have demonstrated that satellite cells are heterogeneous and that subpopulations of satellite stem cells are able to perform asymmetric divisions to generate myogenic progenitors or symmetric divisions to expand the satellite cell pool. Thus, a complex balance between extrinsic cues and intrinsic regulatory mechanisms is needed to tightly control satellite cell cycle progression and cell fate determination. Defects in satellite cell regulation or in their niche, as observed in degenerative conditions such as aging, can impair muscle regeneration. Here, we review recent discoveries of the intrinsic and extrinsic factors that regulate satellite cell behaviour in regenerating and degenerating muscles.
In this study, we investigated whether p-anisaldehyde (PAA), the main component of essential oils derived from anise seeds, influences the differentiation of mouse C2C12 myoblasts. Cells were induced ...to differentiate over 5 days using a differentiation medium with or without PAA (50 or 200 mg/mL). Myotube length and diameter were measured, and the expressions of myogenic markers (myoblast determination protein 1, myogenin, myocyte enhancer factor 2, muscle creatine kinase, and myosin heavy chain) and atrophy-related genes (atrogin-1 and muscle ring finger-1 MuRF-1) were assessed by quantitative real-time polymerase chain reaction. Additionally, protein kinase B (Akt) phosphorylation was monitored by western blotting. PAA significantly induced the formation of smaller and thinner myotubes and reduced myogenic marker expression. Furthermore, PAA increased the expressions of atrogin-1 and MuRF-1 and simultaneously reduced Akt phosphorylation. Our findings indicate that PAA inhibits the myogenic differentiation of C2C12 cells by reducing the phosphorylation and activation of Akt.
C2C12 근육모세포의 분화에서 p -anisaldehyde의 역할 김달아; Dal-ah Kim; 공경혜 ...
Korean journal of clinical laboratory science,
09/2023, Volume:
55, Issue:
3
Journal Article
Peer reviewed
Open access
골격근은 대사, 열기반 온도 조절, 그리고 전반적인 체내 균형을 위해 필수적인 조직이고 근발생(myogenesis)이라는 다단계 과정을 거쳐서 근관세포를 형성한다. p-아니스알데하이드(p-anisaldehyde, PAA) (4-메톡시벤잘데하이드)는 아니스 씨에서 추출된 에센셜 오일의 주성분이지만, 골격근에서의 기능은 아직까지 알려져 있지 않다. 따라서, ...우리는 마우스 C2C12 근육모세포를 이용하여 근육분화가 PAA에 의해 영향을 받는지를 연구하였다. C2C12 근육모세포의 분화를 유도하기 위해 이 세포를 분화 배지에서 5일동안 배양하였고, 매일 PAA (50 또는 200 μg/mL)를 포함하는 새로운 배지로 교체하였다. 대조군으로서 PAA가 포함되지 않은 배지를 사용하였다. 우리는 분화시작 후 1, 3, 5일째에 근관세포의 길이와 지름을 측정함으로써 PAA가 근관 형성에 미치는 영향을 평가하였고, quantitative real-time polymerase chain reaction 분석을 통해 PAA가 근육 표지인자(myoblast determination protein 1, myogenin, myocyte enhancer factor 2C, muscle creatine kinase, 및 myosin heavy chain)와 근육위축 관련 유전자(atrogin-1과 muscle ring finger-1 MuRF-1)의 발현에 미치는 영향을 분석하였다. 또한, 주요 근육형성 키나아제인 protein kinase B (Akt)의 인산화를 웨스턴 블롯을 이용해 관찰하였다. 그 결과 PAA가 더 작고 얇은 근관 형성을 유의하게 유발하며 근육 표지인자의 발현을 감소시킨다는 것을 확인하였다. 또한, atrogin-1과 MuRF-1의 발현이 PAA에 의해서 감소하였는데, 이는 Akt 인산화의 감소와 일치하는 결과이다. 결론적으로, 본 연구결과는 PAA가 Akt 인산화와 활성화를 감소시킴으로써 C2C12 세포에서의 근육 분화를 억제하는 역할을 한다는 것을 증명한다.
In this study, we investigated whether p-anisaldehyde (PAA), the main component of essential oils derived from anise seeds, influences the differentiation of mouse C2C12 myoblasts. Cells were induced to differentiate over 5 days using a differentiation medium with or without PAA (50 or 200 mg/mL). Myotube length and diameter were measured, and the expressions of myogenic markers (myoblast determination protein 1, myogenin, myocyte enhancer factor 2, muscle creatine kinase, and myosin heavy chain) and atrophy-related genes (atrogin-1 and muscle ring finger-1 MuRF-1) were assessed by quantitative real-time polymerase chain reaction. Additionally, protein kinase B (Akt) phosphorylation was monitored by western blotting. PAA significantly induced the formation of smaller and thinner myotubes and reduced myogenic marker expression. Furthermore, PAA increased the expressions of atrogin-1 and MuRF-1 and simultaneously reduced Akt phosphorylation. Our findings indicate that PAA inhibits the myogenic differentiation of C2C12 cells by reducing the phosphorylation and activation of Akt.
Skeletal myogenesis serves as a paradigm to investigate the molecular mechanisms underlying exquisitely regulated cell fate decisions in developing embryos. The evolutionarily conserved miR-133 ...family of microRNAs is expressed in the myogenic lineage, but how it acts remains incompletely understood. Here, we performed genome-wide differential transcriptomics of miR-133 knockdown (KD) embryonic somites, the source of vertebrate skeletal muscle. These analyses, performed in chick embryos, revealed extensive downregulation of Sonic hedgehog (Shh) pathway components: patched receptors, Hedgehog interacting protein and the transcriptional activator Gli1. By contrast,
, a transcriptional repressor, was de-repressed and confirmed as a direct miR-133 target. Phenotypically, miR-133 KD impaired myotome formation and growth by disrupting proliferation, extracellular matrix deposition and epithelialization. Together, these observations suggest that miR-133-mediated
silencing is crucial for embryonic myogenesis. Consistent with this idea, we found that activation of Shh signalling by either purmorphamine, or KD of
by antisense morpholino, rescued the miR-133 KD phenotype. Thus, we identify a novel Shh/myogenic regulatory factor/miR-133/Gli3 axis that connects epithelial morphogenesis with myogenic fate specification.
Background: Obesity is often accompanied by deficits in skeletal muscle fatty acid oxidation (FAO). Here, we tested the hypothesis that predisposition for excess adiposity may be linked to early life ...deficits in FAO. We used myogenic differentiated mesenchymal stem cells (MSCs) from infant umbilical cord tissue. Methods: In a subset of pregnant women from the Healthy Start Study (age: 28.7±6 .2 y; BMI: 25.0±5.1 kg/m2; gestational age: 39.5±1.3 weeks), we measured infant MSC (n=116) FAO under two conditions: control (21d myogenesis) and 21d myogenesis + 24h excess fatty acid exposure (200 µM, 2:1 oleate:palmitate + 1 mM carnitine. MSC metabolic health index was based on the sum of Z-score from the FAO variables (total fat uptake, total fat oxidation, ratio of acid-soluble metabolites ASM, incomplete fat oxidation and complete oxidation to CO2 ASM/CO2). Child adiposity from the same infants was measured via whole-body air plethysmography at age 4-6y. We used multiple linear regression to investigate the association between MSC's metabolic health index and child adiposity adjusted for infant sex, age at adiposity measure, and any breastfeeding at 12-mo of age. To account for normality deviations, 95% confidence intervals (CI) were estimated via bootstrapping. Results: Sixty-five children (40 male/25 female; age: 4.6±0.2 y; BMI: 15.6±2.3 kg/m2; fat mass: 19.7±7.2%; fat free mass: 80.3±7.7%) were analyzed. MSC metabolic health index was positively associated with child adiposity (ß=0.46, p=0.03; CI: 0.13-0.80). Conclusions: Elevated MSC metabolic health index, indicative of poor fatty acid metabolism during myogenesis, may be an earlier marker for excess adiposity during childhood. Future studies using infant MSCs should further investigate the molecular underpinnings of early pre-disposition for obesity in humans.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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