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Background: Previous studies have demonstrated the role of N6-methyladenosine (m 6 A) RNA methylation in various biological processes, our research is the first to elucidate its specific impact on LCAT mRNA stability and adipogenesis in poultry., Results: The 6 100-day-old female chickens were categorized into high (n = 3) and low-fat chickens (n = 3) based on their abdominal fat ratios, and their abdominal fat tissues were processed for MeRIP-seq and RNA-seq. An integrated analysis of MeRIP-seq and RNA-seq omics data revealed 16 differentially expressed genes associated with to differential m 6 A modifications. Among them, ELOVL fatty acid elongase 2 (ELOVL2), pyruvate dehydrogenase kinase 4 (PDK4), fatty acid binding protein 9 (PMP2), fatty acid binding protein 1 (FABP1), lysosomal associated membrane protein 3 (LAMP3), lecithin-cholesterol acyltransferase (LCAT) and solute carrier family 2 member 1 (SLC2A1) have ever been reported to be associated with adipogenesis. Interestingly, LCAT was down-regulated and expressed along with decreased levels of mRNA methylation methylation in the low-fat group. Mechanistically, the highly expressed ALKBH5 gene regulates LCAT RNA demethylation and affects LCAT mRNA stability. In addition, LCAT inhibits preadipocyte proliferation and promotes preadipocyte differentiation, and plays a key role in adipogenesis., Conclusions: In conclusion, ALKBH5 mediates RNA stability of LCAT through demethylation and affects chicken adipogenesis. This study provides a theoretical basis for further understanding of RNA methylation regulation in chicken adipogenesis., (© 2024. The Author(s).)

Background: Transmembrane proteins are vital for intercellular signalling and play important roles in the control of cell fate. However, their physiological functions and mechanisms of action in myogenesis and muscle disorders remain largely unexplored. It has been found that transmembrane protein 182 (TMEM182) is dramatically up-regulated during myogenesis, but its detailed functions remain unclear. This study aimed to analyse the function of TMEM182 during myogenesis and muscle regeneration., Methods: RNA sequencing, quantitative real-time polymerase chain reaction, and immunofluorescence approaches were used to analyse TMEM182 expression during myoblast differentiation. A dual-luciferase reporter assay was used to identify the promoter region of the TMEM182 gene, and a chromatin immunoprecipitation assay was used to investigate the regulation TMEM182 transcription by MyoD. We used chickens and TMEM182-knockout mice as in vivo models to examine the function of TMEM182 in muscle growth and muscle regeneration. Chickens and mouse primary myoblasts were used to extend the findings to in vitro effects on myoblast differentiation and fusion. Co-immunoprecipitation and mass spectrometry were used to identify the interaction between TMEM182 and integrin beta 1 (ITGB1). The molecular mechanism by which TMEM182 regulates myogenesis and muscle regeneration was examined by Transwell migration, cell wound healing, adhesion, glutathione-S-transferse pull down, protein purification, and RNA immunoprecipitation assays., Results: TMEM182 was specifically expressed in skeletal muscle and adipose tissue and was regulated at the transcriptional level by the myogenic regulatory factor MyoD1. Functionally, TMEM182 inhibited myoblast differentiation and fusion. The in vivo studies indicated that TMEM182 induced muscle fibre atrophy and delayed muscle regeneration. TMEM182 knockout in mice led to significant increases in body weight, muscle mass, muscle fibre number, and muscle fibre diameter. Skeletal muscle regeneration was accelerated in TMEM182-knockout mice. Furthermore, we revealed that the inhibitory roles of TMEM182 in skeletal muscle depend on ITGB1, an essential membrane receptor involved in cell adhesion and muscle formation. TMEM182 directly interacted with ITGB1, and this interaction required an extracellular hybrid domain of ITGB1 (aa 387-470) and a conserved region (aa 52-62) within the large extracellular loop of TMEM182. Mechanistically, TMEM182 modulated ITGB1 activation by coordinating the association between ITGB1 and laminin and regulating the intracellular signalling of ITGB1. Myogenic deletion of TMEM182 increased the binding activity of ITGB1 to laminin and induced the activation of the FAK-ERK and FAK-Akt signalling axes during myogenesis., Conclusions: Our data reveal that TMEM182 is a novel negative regulator of myogenic differentiation and muscle regeneration., (© 2021 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders.)

Excessive abdominal fat deposition is an issue with general concern in broiler production, especially for Chinese native chicken breeds. A high-fat diet (HFD) can induce body weight gained and excessive fat deposition, and genes and pathways participate in fat metabolism and adipogenesis would be influenced by HFD. In order to reveal the main genes and pathways involved in chicken abdominal fat deposition, we used HFD and normal diet (ND) to feed a Chinese native chicken breed, respectively. Results showed that HFD can increase abdominal fat deposition and induce adipocyte hypertrophy. Additionally, we used RNA-sequencing to identify the differentially expressed genes (DEGs) between HFD and ND chickens in liver and abdominal fat. By analyzed these DEGs, we found that the many DEGs were enriched in fat metabolism related pathways, such as peroxisome proliferator-activated receptor (PPAR) signaling, fat digestion and absorption, extracellular matrix (ECM)-receptor interaction, and steroid hormone biosynthesis. Notably, the expression of insulin-like growth factor II mRNA binding protein 1 (IGF2BP1) , which is a binding protein of IGF2 mRNA, was found to be induced in liver and abdominal fat by HFD. Ectopic expression of IGF2BP1 in chicken liver-related cell line Leghorn strain M chicken hepatoma (LMH) cell revealed that IGF2BP1 can regulate the expression of genes associated with fatty acid metabolism. In chicken preadipocytes (ICP cell line), we found that IGF2BP1 can promote adipocyte proliferation and differentiation, and the lipid droplet content would be increased by overexpression of IGF2BP1 . Taken together, this study provides new insights into understanding the genes and pathways involved in abdominal fat deposition of Chinese native broiler, and IGF2BP1 is an important candidate gene for the study of fat metabolism and adipogenesis in chicken.

Background: Previous studies have demonstrated the role of N6-methyladenosine (m6A) RNA methylation in various biological processes, our research is the first to elucidate its specific impact on LCAT mRNA stability and adipogenesis in poultry. Results: The 6 100-day-old female chickens were categorized into high (n = 3) and low-fat chickens (n = 3) based on their abdominal fat ratios, and their abdominal fat tissues were processed for MeRIP-seq and RNA-seq. An integrated analysis of MeRIP-seq and RNA-seq omics data revealed 16 differentially expressed genes associated with to differential m6A modifications. Among them, ELOVL fatty acid elongase 2 (ELOVL2), pyruvate dehydrogenase kinase 4 (PDK4), fatty acid binding protein 9 (PMP2), fatty acid binding protein 1 (FABP1), lysosomal associated membrane protein 3 (LAMP3), lecithin-cholesterol acyltransferase (LCAT) and solute carrier family 2 member 1 (SLC2A1) have ever been reported to be associated with adipogenesis. Interestingly, LCAT was down-regulated and expressed along with decreased levels of mRNA methylation methylation in the low-fat group. Mechanistically, the highly expressed ALKBH5 gene regulates LCAT RNA demethylation and affects LCAT mRNA stability. In addition, LCAT inhibits preadipocyte proliferation and promotes preadipocyte differentiation, and plays a key role in adipogenesis. Conclusions: In conclusion, ALKBH5 mediates RNA stability of LCAT through demethylation and affects chicken adipogenesis. This study provides a theoretical basis for further understanding of RNA methylation regulation in chicken adipogenesis. [ABSTRACT FROM AUTHOR]

The Ras and Rab interactor 2 (RIN2) gene, which encodes RAS and Rab interacting protein 2, can interact with GTP-bound Rab5 and participate in early endocytosis. This study found a 61-bp insertion/deletion (indel) in the RIN2 intron region, and 3 genotypes II , ID , and DD were observed. Genotype analysis of mutation sites was performed on 665 individuals from F2 population and 8 chicken breeds. It was found that the indel existed in each breed and that yellow feathered chickens were mainly of the DD genotype. Correlation analysis of growth and carcass traits in the F2 population of Xinghua and White Recessive Rock chickens showed that the 61-bp indel was significantly correlated with abdominal fat weight, abdominal fat rate, fat width, and hatching weight (P < 0.05). RIN2 mRNA was expressed in all the tested tissues, and its expression in abdominal fat was higher than that in other tissues. In addition, the expression of the RIN2 mRNA in the abdominal fat of the DD genotype was significantly higher than that of the II genotype (P < 0.05). The transcriptional activity results showed that the luciferase activity of the pGL3-DD vector was significantly higher than that of the pGL3-II vector (P < 0.01). Moreover, the results indicate that the polymorphisms in transcription factor binding sites (TFBSs) of 61-bp indel may affect the transcriptional activity of RIN2 , and thus alter fat traits in chicken. The results of this study showed that the 61-bp indel was closely related to abdominal fat-related and hatching weight traits of chickens, which may have reference value for molecular marker-assisted selection of chickens. [ABSTRACT FROM AUTHOR]

Sex-linked dwarf (SLD) chicken, which is caused by a recessive mutation of the growth hormone receptor (GHR), has been widely used in the Chinese broiler industry. However, it has been found that the SLD chicken has more abdominal fat deposition than normal chicken. Excessive fat deposition not only reduced the carcass quality of the broilers but also reduced the immunity of broilers to diseases. To find out the key genes and the precise regulatory pathways that were involved in the GHR mutation-induced excessive fat deposition, we used high-fat diet (HFD) and normal diet to feed the SLD chicken and normal chicken and analyzed the differentially expressed genes (DEGs) among the four groups. Results showed that the SLD chicken had more abdominal fat deposition and larger adipocytes size than normal chicken and HFD can promote abdominal fat deposition and induce adipocyte hypertrophy. RNA sequencing results of the livers and abdominal fats from the above chickens revealed that many DEGs between the SLD and normal chickens were enriched in fat metabolic pathways, such as peroxisome proliferator-activated receptor (PPAR) signaling, extracellular matrix (ECM)-receptor pathway, and fatty acid metabolism. Importantly, by constructing and analyzing the GHR -downstream regulatory network, we found that suppressor of cytokine signaling 2 (SOCS2) and cytokine-inducible SH2-containing protein (CISH) may involve in the GHR mutation-induced abdominal fat deposition in chicken. The ectopic expression of SOCS2 and CISH in liver-related cell line leghorn strain M chicken hepatoma (LMH) cell and immortalized chicken preadipocytes (ICP) revealed that these two genes can regulate fatty acid metabolism, adipocyte differentiation, and lipid droplet accumulation. Notably, overexpression of SOCS2 and CISH can rescue the hyperactive lipid metabolism and excessive lipid droplet accumulation of primary liver cell and preadipocytes that were isolated from the SLD chicken. This study found some genes and pathways involved in abdominal fat deposition of the SLD chicken and reveals that SOCS2 and CISH are two key genes involved in the GHR mutation-induced excessive fat deposition of the SLD chicken. [ABSTRACT FROM AUTHOR]