Anxiang Wen

Role of miR-181a-5p and endoplasmic reticulum stress in the regulation of myogenic differentiation

Accumulating evidence has indicated that microRNAs (miRNAs) and endoplasmic reticulum (ER) stress play critical roles in myoblast differentiation. However, the regulation roles of miRNAs and ER stress in myogenic differentiation have not been fully revealed and need to be further studied. Here, we discovered that the expression levels of miR-181a-5p were strongly upregulated during C2C12 cell differentiation. miR-181a-5p overexpression promoted ER stress and differentiation of C2C12 cells, which was accompanied by increasing expression levels of marker genes related to ER stress-mediated apoptosis and myogenic differentiation. Opposite results were observed after inhibition of the miR-181a-5p expression. The gain- and loss-of-function experiments on C2C12 cells showed that miR-181a-5p affected the development of muscle fiber type, but had no significant influence on C2C12 cell proliferation. In the ER-stressed C2C12 cells induced by thapsigargin (Tg), the expression levels of both miR-181a-5p and marker genes related to ER stress and myogenesis were upregulated. In the ER-stressed C2C12 cells and porcine muscle fibroblast (PMF) cells pretreated with Tg, we found that miR-181a-5p targeted glucose-regulated protein, 78kDa/binding immunoglobulin protein (GRP78/BIP), and influenced cell apoptosis. In conclusion, these results indicate that miR-181a-5p and ER stress have positive synergistic effects on myogenic differentiation by increasing the expression levels of myogenic differentiation key genes and activating the ER stress-mediated apoptosis signaling pathway.

Tissue expression pattern and polymorphism of G0S2 gene in porcine.

Adipose triglyceride lipase (ATGL), catalyzing the initial step of hydrolysis of triacylglycerol (TAG) in adipocytes, has been known to be inhibited by G0/G1 switch protein 2 (G0S2). In this study, we determined tissue expression pattern and polymorphism of G0S2 gene in porcine. The results showed that the G0S2 transcript levels were very high in the liver and, to a lesser degree, in adipose tissues of greater omentum and suet fat; and low G0S2 transcript levels were observed in other tissues. A comparative study on the transcript levels between ATGL and G0S2 genes showed that ATGL transcript levels were high in all six adipose tissues, but negligible in the liver. Higher transcript levels were obtained for sows in adipose tissues of the inner layer of subcutaneous fat and suet fat, but higher expression values were found for boars in the liver, spleen, and stomach. 19 single nucleotide polymorphisms (SNPs), including 4 nonsynonymous SNPs (g.-307A>T, g.-394C>G, g.-565G>A, and g.-566T>C), were found in porcine G0S2 genomic DNA. Association analyses showed that the g.-565G>A and g.-742T>A SNPs were associated with back fat thickness (BFT). In conclusion, G0S2 mRNAs are abundantly expressed in porcine liver and adipose tissues of greater omentum and suet fat, and sex affects porcine G0S2 tissue transcript levels; meanwhile, the genetic diversity of porcine G0S2 gene is abundant and 2 SNPs are a genetic factor affecting BFT.

Cloning of porcine GPIHBP1 gene and its tissue expression pattern and genetic effect on adipose traits

Lipoprotein lipase (LPL) is a key enzyme in lipid metabolism and is transported by glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) from the interstitial spaces to the capillary lumen. Here, we cloned a cDNA and the genomic locus of the porcine GPIHBP1 gene, and investigated its tissue expression pattern and its genetic effects on adipose traits. Porcine GPIHBP1 exhibits a four-exon/three-intron structure, including a 543bp open reading frame that encodes 180 amino acids. The porcine GPIHBP1 protein shows 49%-65% homology and shares the major conserved structural domains of GPIHBP1 proteins in other mammals. Porcine GPIHBP1 mRNA levels were high in the adipose tissue, muscle and lung, and higher mRNA levels were observed in sows compared to boars in adipose tissues of the inner and outer layers of subcutaneous fat, abdominal fat, and suet fat. The mRNA expression pattern of porcine GPIHBP1 and LPL genes was similar in most tissues except for the lung. Thirty six single nucleotide polymorphisms (SNPs) were found in the porcine GPIHBP1 gene. Association analyses showed that the g.-255G>C and g.-626T>G SNPs are associated with intramuscular fat content, and that the g.-1557T>C and g.-1948G>A SNPs are associated with back fat thickness. In conclusion, porcine GPIHBP1 mRNA is abundantly expressed in the adipose tissue, muscle and lung, and gender affects GPIHBP1 mRNA expression levels; furthermore, four GPIHBP1 SNPs are genetic factors affecting adipose traits.

Characterization of the Gut Microbiota in Six Geographical Populations of Chinese Rhesus Macaques ( Macaca mulatta ), Implying an Adaptation to High-Altitude Environment

Knowledge about the impact of different geographical environments on rhesus macaque gut microbiota is limited. In this study, we compared the characteristics of gut microbiota in six different Chinese rhesus macaque populations, including Hainan, Nanning, Guizhou, Xichang, Jianchuan and Tibet. Through the composition analysis of operational taxonomic units (OTUs), we found that there were significant differences in the abundance of core overlapping OTUs in the six Chinese groups. Specifically, the Tibet population exhibited the highest gut microbial diversity and the most unique OTUs. Statistically significant differences in the composition of gut microbiota among the six groups at phylum and family level were evident. Specifically, Tibet had higher abundances of Firmicutes and lower abundances of Bacteroidetes than the other geographical groups, and the higher abundance of Firmicutes in the Tibetan group was mainly caused by a significant increase in the family Ruminococcaceae and Christensenellaceae. Phylogenetic investigation of communities by reconstruction of unobserved state analysis showed that the enrichment ratio for environmental information processing and organismal systems was the highest in the Tibet population. Additionally, our results suggested that in the adaptation process of rhesus macaques to different geographical environments, the abundance of the core common flora of the intestinal microbes had undergone varying degree of change and produced new and unique flora, both of which helped to reshape the gut microbiota of rhesus macaques. In particular, this change was more obvious for animals in the high-altitude environments.

Transcriptome-wide N 6 -methyladenosine methylome profiling of porcine muscle and adipose tissues reveals a potential mechanism for transcriptional regulation and differential methylation pattern

BackgroundN6-methyladenosine (m6A) is the most prevalent internal form of modification in messenger RNA in higher eukaryotes and potential regulatory functions of reversible m6A methylation on mRNA have been revealed by mapping of m6A methylomes in several species. m6A modification in active gene regulation manifests itself as altered methylation profiles in a tissue-specific manner or in response to changing cellular or species living environment. However, up to date, there has no data on m6A porcine transcriptome-wide map and its potential biological roles in adipose deposition and muscle growth.MethodsIn this work, we used methylated RNA immunoprecipitation with next-generation sequencing (MeRIP-Seq) technique to acquire the first ever m6A porcine transcriptome-wide map. Transcriptomes of muscle and adipose tissues from three different pig breeds, the wild boar, Landrace, and Rongchang pig, were used to generate these maps.ResultsOur findings show that there were 5,872 and 2,826 m6A peaks respectively, in the porcine muscle and adipose tissue transcriptomes. Stop codons, 3′-untranslated regions, and coding regions were found to be mainly enriched for m6A peaks. Gene ontology analysis revealed that common m6A peaks in nuclear genes are associated with transcriptional factors, suggestive of a relationship between m6A mRNA methylation and nuclear genome transcription. Some genes showed tissue- and breed-differential methylation, and have novel biological functions. We also found a relationship between the m6A methylation extent and the transcript level, suggesting a regulatory role for m6A in gene expression.ConclusionThis comprehensive map provides a solid basis for the determination of potential functional roles for RNA m6A modification in adipose deposition and muscle growth.

Activities Analysis and Polymorphisms Identification of GPIHBP1 Promoter Region in Porcine

GPIHBP1 is expressed restrictively in capillary endothelial cells, but the transcriptional regulation mechanisms of GPIHBP1 in capillaries are still unknown. Here, we analyzed the promoter activities of porcine GPIHBP1 using dual luciferase reporter assays and detected single nucleotide polymorphisms (SNPs) in the promoter region. Activity analysis discovered that the sequence from–187 to +174 is a basal promoter region, the sequence from–187 to–582 is a positive regulation region, whereas the sequence from–582 to–1321 is a negative regulation region. 11 SNPs were found in the promoter region of porcine GPIHBP1, and the g.-796G>A SNP within the NF-l-binding site is associated with pig back fat thickness. The work performed here will serve as a valuable resource for discovering the expression regulation mechanism of GPIHBP1 and promoting further development of pig as a model organism for human cardiovascular disease research.

Comprehensive transcriptional landscape of porcine cardiac and skeletal muscles reveals differences of aging

Aging significantly affects the cardiac muscle (CM) and skeletal muscles (SM). Since the aging process of CM and SM may be different, high throughput RNA sequencing was performed using CM and SM in different age conditions to evaluate the expression profiles of messenger RNA (mRNA), long non-coding RNA (lncRNA), micro RNA (miRNA), and circular (circRNA). Several mRNAs, lncRNAs, and miRNAs were highly expressed and consistently appeared in both ages in one of the two muscle tissues. Gene ontology (GO) annotation described that these genes were required for maintaining normal biological functions of CM and SM tissues. Furthermore, 26 mRNAs, 4 lncRNAs, 22 miRNAs, and 26 circRNAs were differentially expressed during cardiac muscle aging. Moreover, 81 mRNAs, 5 lncRNAs, 79 miRNAs, and 62 circRNAs were differentially expressed during aging of skeletal muscle. When comparing the expression profiles of CM and SM during aging, the senescence process in CM and SM was found to be fundamentally different. In addition, we assessed multi-group cooperative control relationships and constructed circRNA-miRNA-mRNA co-expression networks in muscular aging. In conclusion, our findings will contribute to the understanding of muscular aging and provide a foundation for future studies on the molecular mechanisms underlying muscular aging.

Complete mitochondrial genome and phylogenetic analysis of a Chinese Eurasian lynx (Lynx lynx)

Abstract The complete mitochondrial genome of Eurasian lynx (Lynx lynx) from China has been described in this study. It has a circular genome of 16,996 bp with a higher A + T content of 58.65%, and the base composition is A: 32.31%, G: 14.29%, T: 26.35%, C: 27.06%. When compared with the reported individual (KR919624) from China, there are 81 variations and 58 base deletion between the two sequences. The phylogenetic analysis indicated our sequence separated clearly from Eurasian lynx individuals in the previous publications. These results could provide more molecular information for the conservation of Eurasian lynx genetic resources.

Complete mitochondrial genome of black-shanked douc langurs (Pygathrix nigripes) and its phylogenetic analysis

Abstract In this study, we first characterized the complete mitogenome of Pygathrix nigripes, and analysed its phylogenetic status. The circular mitogenome was 16,534 bp in length, and contained 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and one non-coding control region (D-loop). These genes except ND6 and 8 tRNA genes were encoded on the H-strand. The phylogenetic analysis exhibited that our sequence formed a sister branch with P. cinereal and P. nemaeus of genus Pygathrix, which showed a closer genetic relationship of the three species. These information contribute to molecular, phylogenetic studies and genetic diversity conservation for this species.

Complete mitochondrial genome of Schizopygopsis chengi chengi (Cyprinidae, Schizothoracinae, Schizopygopsis).

Abstract The complete mitochondrial DNA sequence of Schizopygopsis chengi chengi collected from the Dadu River was determined in this study. The complete mitochondrial genome of S. chengi chengi was a circular molecule of 16 688 bp in size, and all genes showed the typical gene arrangement conforming to the vertebrate consensus. Twelve protein-coding genes (except ND6) of S. chengi chengi and other 22 Schizothoracinae species from two genera were used for phylogenetic analysis by Bayesian inference and maximum likelihood methods. The topology confirmed the close genetic relationship between S. chengi chengi and S. chengi baoxinggensis.