RNA-Seq Analysis Reveals a Positive Role of HTR2A in Adipogenesis in Yan Yellow Cattle

Proteome Analysis Related to Unsaturated Fatty Acid Synthesis by Interfering with Bovine Adipocyte ACSL1 Gene

Unsaturated fatty acids (UFAs) in beef play a vital role in promoting human health. Long-chain fatty acyl-CoA synthase 1 (ACSL1) is a crucial gene for UFA synthesis in bovine adipocytes. To investigate the protein expression profile during UFA synthesis, we performed a proteomic analysis of bovine adipocytes by RNA interference and non-interference with ACSL1 using label-free techniques. A total of 3558 proteins were identified in both the NC and si-treated groups, of which 1428 were differentially expressed proteins (DEPs; fold change ≥ 1.2 or ≤ 0.83 and p-value < 0.05). The enrichment analysis of the DEPs revealed signaling pathways related to UFA synthesis or metabolism, including cAMP, oxytocin, fatty acid degradation, glycerol metabolism, insulin, and the regulation of lipolysis in adipocytes (p-value < 0.05). Furthermore, based on the enrichment analysis of the DEPs, we screened 50 DEPs that potentially influence the synthesis of UFAs and constructed an interaction network. Moreover, by integrating our previously published transcriptome data, this study established a regulatory network involving differentially expressed long non-coding RNAs (DELs), highlighting 21 DEPs and 13 DELs as key genes involved in UFA synthesis. These findings present potential candidate genes for further investigation into the molecular mechanisms underlying UFA synthesis in bovines, thereby offering insights to enhance the quality of beef and contribute to consumer health in future studies.

A review of the role of transcription factors in regulating adipogenesis and lipogenesis in beef cattle

In the past few decades, genomic selection and other refined strategies have been used to increase the growth rate and lean meat production of beef cattle. Nevertheless, the fast growth rates of cattle breeds are often accompanied by a reduction in intramuscular fat (IMF) deposition, impairing meat quality. Transcription factors play vital roles in regulating adipogenesis and lipogenesis in beef cattle. Meanwhile, understanding the role of transcription factors in regulating adipogenesis and lipogenesis in beef cattle has gained significant attention to increase IMF deposition and meat quality. Therefore, the aim of this paper was to provide a comprehensive summary and valuable insight into the complex role of transcription factors in adipogenesis and lipogenesis in beef cattle. This review summarizes the contemporary studies in transcription factors in adipogenesis and lipogenesis, genome-wide analysis of transcription factors, epigenetic regulation of transcription factors, nutritional regulation of transcription factors, metabolic signalling pathways, functional genomics methods, transcriptomic profiling of adipose tissues, transcription factors and meat quality and comparative genomics with other livestock species. In conclusion, transcription factors play a crucial role in promoting adipocyte development and fatty acid biosynthesis in beef cattle. They control adipose tissue formation and metabolism, thereby improving meat quality and maintaining metabolic balance. Understanding the processes by which these transcription factors regulate adipose tissue deposition and lipid metabolism will simplify the development of marbling or IMF composition in beef cattle.

Circular RNA mapping reveals CircCWC22 as a MiR-3059-x sponge in yak fat deposition by regulating HMGCL

The regulatory mechanisms and functions of circular RNAs (circRNAs) in yak intramuscular fat (IMF) deposition remain unclear. This study aimed to investigate yak circRNAs with high and low IMF content using high-throughput sequencing. A total of 270 differentially expressed circRNAs were identified, of which 129 were upregulated and 141 were downregulated. Among these circRNAs, circCWC22, derived from the yak CWC22 gene, was further studied to understand its functions and regulatory mechanisms. Sequencing and RNase R processing confirmed the circular nature of circCWC22. By constructing a circRNA-miRNA-mRNA co-expression network, the potential regulatory pathway of circCWC22/miR-3059-x/HMGCL was identified. To investigate the roles of circCWC22, miR-3059-x, and HMGCL in the deposition of yak intramuscular preadipocytes (YIMAs), CCK-8, EdU, BODIPY, triglyceride content, and qRT-PCR analyses were performed. The results demonstrated that circCWC22, miR-3059-x, and HMGCL promoted the differentiation and inhibited the proliferation of YIMAs. Using the dual-luciferase reporter system and qRT-PCR, we confirmed that circCWC22 adsorbed miR-3059-x, and HMGCL was identified as a target gene of miR-3059-x. In conclusion, this study uncovered a large number of potential circRNAs involved in IMF deposition and highlighted the significant role of circCWC22 in yak IMF deposition via the circCWC22/miR-3059-x/HMGCL axis.

Transcriptional Inhibition of AGPAT2 Induces Abnormal Lipid Metabolism and Oxidative Stress in the Liver of Nile Tilapia Oreochromis niloticus

The enzyme 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2) is an intermediate enzyme in triglyceride synthesis. The aim was to study the regulatory mechanism of AGPAT2 on Nile tilapia, Oreochromis niloticus. In this study, antisense RNA technology was used to knock-down AGPAT2 in Nile tilapia. Compared with the control groups (transfected with ultrapure water or the blank expression vector), the AGPAT2 knock-down group showed a significantly higher weight gain rate, special growth rate, visceral somatic index, and hepatopancreas somatic index; and significantly increased the total cholesterol, triglycerides, glucose, low-density lipoprotein cholesterol, and insulin levels in serum. In addition, the contents of total cholesterol and triglycerides and the abundance of superoxide dismutase, catalase, and glutathione peroxidase in the liver significantly increased, while the malondialdehyde content significantly decreased. The liver cells became severely vacuolated and accumulated lipids in the AGPAT2 knock-down group. Comparative transcriptome analyses (AGPAT2 knock-down vs. control group) revealed 1789 differentially expressed genes (DEGs), including 472 upregulated genes and 1313 downregulated genes in the AGPAT2 knock-down group. Functional analysis showed that the main pathway of differentially expressed genes enrichment was lipid metabolism and oxidative stress, such as steroid biosynthesis, unsaturated fatty acid biosynthesis, the PPAR signaling pathway, and the P53 pathway. We used qRT-PCR to verify the mRNA expression changes of 13 downstream differential genes in related signaling pathways. These findings demonstrate that knock-down of AGPAT2 in tilapia leads to abnormal lipid metabolism and oxidative stress.

Genome-wide survey and functional analysis reveal TCF21 promotes chicken preadipocyte differentiation by directly upregulating HTR2A

BACKGROUND/AIM

Previously, we showed that transcription factor 21 (TCF21) promotes chicken preadipocyte differentiation. However, the genome-wide TCF21 binding sites and its downstream target genes in chicken adipogenesis were unknown.

METHODS

ChIP-Seq and RNA-Seq were used to screen candidate targets of TCF21. qPCR and luciferase reporter assay were applied to verify the sequencing results. Western blotting, oil red-O staining and pharmacological treatments were performed to investigate the function of 5-hydroxytryptamine receptor 2A (HTR2A), one of the bonafide direct downstream binding targets of TCF21.

RESULTS

A total of 94 candidate target genes of TCF21 were identified. ChIP-qPCR, RT-qPCR, and luciferase reporter assay demonstrated that HTR2A is one of the bonafide direct downstream binding targets of TCF21. HTR2A expression in adipose tissue was upregulated in fat line broilers. Also, the abundance of HTR2A gradually increased during the adipogenesis process. Interestingly, pharmacological enhancement or inhibition of HTR2A promoted or attenuated the differentiation of preadipocytes, respectively. Furthermore, HTR2A inhibition impaired the TCF21 promoted adipogenesis.

CONCLUSIONS

We profiled the genome-wide TCF21 binding sites in chicken differentiated preadipocytes revealing HTR2A as the direct downstream target of TCF21 in adipogenesis.

Interference With ACSL1 Gene in Bovine Adipocytes: Transcriptome Profiling of mRNA and lncRNA Related to Unsaturated Fatty Acid Synthesis

The enzyme long-chain acyl-CoA synthetase 1 (ACSL1) is essential for lipid metabolism. The ACSL1 gene controls unsaturated fatty acid (UFA) synthesis as well as the formation of lipid droplets in bovine adipocytes. Here, we used RNA-Seq to determine lncRNA and mRNA that regulate UFA synthesis in bovine adipocytes using RNA interference and non-interference with ACSL1. The corresponding target genes of differentially expressed (DE) lncRNAs and the DE mRNAs were found to be enriched in lipid and FA metabolism-related pathways, according to GO and KEGG analyses. The differentially expressed lncRNA- differentially expressed mRNA (DEL-DEM) interaction network indicated that some DELs, such as TCONS_00069661, TCONS_00040771, TCONS_ 00035606, TCONS_00048301, TCONS_001309018, and TCONS_00122946, were critical for UFA synthesis. These findings assist our understanding of the regulation of UFA synthesis by lncRNAs and mRNAs in bovine adipocytes.

Serotonin 5-HT2A receptor activity mediates adipocyte differentiation through control of adipogenic gene expression

Serotonin 5-HT2 receptors are expressed in many tissues and play important roles in biological processes. Although the 5-HT2A receptor is primarily known for its role in central nervous system, it is also expressed in peripheral tissues. We have found that 5-HT2A receptor antagonists inhibit human subcutaneous primary adipocyte differentiation. We also show that siRNA knockdown of the 5-HT2A receptor blocks differentiation. Using gene expression analysis in combination with receptor antagonists we found that activity of 5-HT2A receptors is necessary very early in the differentiation process to mediate expression of adipogenic genes, including peroxisome proliferator-activated receptor gamma (ppar-γ), adipocyte protein 2 (aP2), adiponectin, and serine/threonine-protein kinase 1 (sgk1). We show here for the first time that 5-HT2A receptor activity is necessary for differentiation of human primary subcutaneous preadipocytes to adipocytes, and that 5-HT2A receptor activity mediates key genes related to adipogenesis during this process. Importantly, this work contributes to a greater understanding of the adipocyte differentiation process, as well as to the role of 5-HT2A receptors in peripheral tissues, and may be relevant to the development of novel therapeutic strategies targeting this receptor for the treatment of obesity related diseases.

Interference with ACSL1 gene in bovine adipocytes: Transcriptome profiling of circRNA related to unsaturated fatty acid production

Long-chain acyl-CoA synthetase 1 (ACSL1) is a member of the acyl-CoA synthetase family that plays a vital role in lipid metabolism. We have previously shown that the ACSL1 gene regulates the composition of unsaturated fatty acids (UFAs) in bovine skeletal muscle, which in turn regulates the fatty acid synthesis and the generation of lipid droplets. Here, we used RNA-Seq to screen circRNAs that regulated the expression of ACSL1 gene and other UFA synthesis-related genes by RNA interference and noninterference in bovine adipocytes. The results of KEGG pathway analysis showed that the parental genes of differentially expressed (DE)-circRNAs were primarily enriched in the adipocytokine signaling pathway. The prediction results showed that novel_circ_0004855, novel_circ_0001507, novel_circ_0001731, novel_circ_0005276, novel_circ_0002060, novel_circ_0005405 and novel_circ_0004254 regulated UFA synthesis-related genes by interacting with the related miRNAs. These results could help expand our knowledge of the molecular mechanisms of circRNAs in the regulation of UFA synthesis in bovine adipocytes.

Effect of the ACAA1 Gene on Preadipocyte Differentiation in Sheep

Acetyl-CoA acyltransferase 1 (ACAA1) functions as a key regulator of fatty acid β-oxidation in peroxisomes by catalyzing the cleavage of 3-ketoacyl-CoA to acetyl-CoA and acyl-CoA, which participate in the extension and degradation of fatty acids. Thus, ACAA1 is an important regulator of lipid metabolism and plays an essential role in fatty acid oxidation and lipid metabolism. Our previous study findings revealed that ACAA1 is closely associated with the peroxisome proliferator-activated receptor (PPAR) signaling and fatty acid metabolism pathways, which are involved in fat deposition in sheep, leading to our hypothesis that ACAA1 may be involved in fat deposition by regulating lipid metabolism. However, the associated molecular mechanism remains unclear. In the present study, to assess the potential function of ACAA1 in sheep preadipocyte differentiation, we knocked down and overexpressed ACAA1 in sheep preadipocytes and evaluated the pattern of ACAA1 gene expression during preadipocyte differentiation by qRT-PCR. ACAA1 was significantly expressed in the early stage of adipocyte differentiation, and then its expression decreased. ACAA1 deficiency increased lipid accumulation and the triglyceride content and promoted sheep preadipocyte differentiation, whereas ACAA1 overexpression inhibited adipogenesis and decreased lipid accumulation and the triglyceride content. Simultaneously, we demonstrated that ACAA1 deficiency upregulated the expressions of the adipogenic marker genes PPARγ and C/EBPα in sheep preadipocytes, but ACAA1 overexpression inhibited the expressions of these markers, indicating that ACAA1 affects lipid metabolism by regulating adipogenic marker genes. Our results may promote a better understanding of the regulation of adipogenesis by ACAA1.

Accelerated discovery of functional genomic variation in pigs

The genotype-phenotype link is a major research topic in the life sciences but remains highly complex to disentangle. Part of the complexity arises from the number of genes contributing to the observed phenotype. Despite the vast increase of molecular data, pinpointing the causal variant underlying a phenotype of interest is still challenging. In this study, we present an approach to map causal variation and molecular pathways underlying important phenotypes in pigs. We prioritize variation by utilizing and integrating predicted variant impact scores (pCADD), functional genomic information, and associated phenotypes in other mammalian species. We demonstrate the efficacy of our approach by reporting known and novel causal variants, of which many affect non-coding sequences. Our approach allows the disentangling of the biology behind important phenotypes by accelerating the discovery of novel causal variants and molecular mechanisms affecting important phenotypes in pigs. This information on molecular mechanisms could be applicable in other mammalian species, including humans.

Genetic Parameters and Genome-Wide Association Studies of Quality Traits Characterised Using Imaging Technologies in Rainbow Trout, Oncorhynchus mykiss

One of the top priorities of the aquaculture industry is the genetic improvement of economically important traits in fish, such as those related to processing and quality. However, the accuracy of genetic evaluations has been hindered by a lack of data on such traits from a sufficiently large population of animals. The objectives of this study were thus threefold: (i) to estimate genetic parameters of growth-, yield-, and quality-related traits in rainbow trout (Oncorhynchus mykiss) using three different phenotyping technologies [invasive and non-invasive: microwave-based, digital image analysis, and magnetic resonance imaging (MRI)], (ii) to detect quantitative trait loci (QTLs) associated with these traits, and (iii) to identify candidate genes present within these QTL regions. Our study collected data from 1,379 fish on growth, yield-related traits (body weight, condition coefficient, head yield, carcass yield, headless gutted carcass yield), and quality-related traits (total fat, percentage of fat in subcutaneous adipose tissue, percentage of fat in flesh, flesh colour); genotypic data were then obtained for all fish using the 57K SNP Axiom® Trout Genotyping array. Heritability estimates for most of the 14 traits examined were moderate to strong, varying from 0.12 to 0.67. Most traits were clearly polygenic, but our genome-wide association studies (GWASs) identified two genomic regions on chromosome 8 that explained up to 10% of the genetic variance (cumulative effects of two QTLs) for several traits (weight, condition coefficient, subcutaneous and total fat content, carcass and headless gutted carcass yields). For flesh colour traits, six QTLs explained 1-4% of the genetic variance. Within these regions, we identified several genes (htr1, gnpat, ephx1, bcmo1, and cyp2x) that have been implicated in adipogenesis or carotenoid metabolism, and thus represent good candidates for further functional validation. Finally, of the three techniques used for phenotyping, MRI demonstrated particular promise for measurements of fat content and distribution, while the digital image analysis-based approach was very useful in quantifying colour-related traits. This work provides new insights that may aid the development of commercial breeding programmes in rainbow trout, specifically with regard to the genetic improvement of yield and flesh-quality traits as well as the use of invasive and/or non-invasive technologies to predict such traits.

Macrophage plays important role in cortisol and serotonin induced adipogenesis in vitro

Psychological stress is an important cause to induce various metabolic disorders such as obesity, type II diabetes, and cardiovascular disorders by affecting the visceral adipose tissue. Pathophysiology of these diseases is often accompanied by the hyperactive immune system. The hyperactive immune system causes immune cells to infiltrate in the adipose tissue to increase the severity of metabolic disorders and to affect the levels of stress associated hormones, such as cortisol and serotonin. Cortisol and serotonin, alone or together, could regulate several aspects of the metabolic and immunological deregulations by manipulating the lipid accumulation or adipogenesis in cells. During adipogenesis, macrophages are recruited. Previous reports from the Aich laboratory established the roles of cortisol and serotonin to influence adipogenesis in pre-adipocytes 3T3-L1 in the presence and absence of macrophages. In the current study, we reported the role of macrophage RAW264.7, especially its polarized states, on differentiated murine adipocytes 3T3-L1 in the presence or absence of cortisol and serotonin. The current study also compares the differential role of macrophage recruitment on pre- and differentiated adipocytes.

Molecular Mechanism of Stem Cell Differentiation into Adipocytes and Adipocyte Differentiation of Malignant Tumor

Adipogenesis is the process through which preadipocytes differentiate into adipocytes. During this process, the preadipocytes cease to proliferate, begin to accumulate lipid droplets, and develop morphologic and biochemical characteristics of mature adipocytes. Mesenchymal stem cells (MSCs) are a type of adult stem cells known for their high plasticity and capacity to generate mesodermal and nonmesodermal tissues. Many mature cell types can be generated from MSCs, including adipocyte, osteocyte, and chondrocyte. The differentiation of stem cells into multiple mature phenotypes is at the basis for tissue regeneration and repair. Cancer stem cells (CSCs) play a very important role in tumor development and have the potential to differentiate into multiple cell lineages. Accumulating evidence has shown that cancer cells can be induced to differentiate into various benign cells, such as adipocytes, fibrocytes, osteoblast, by a variety of small molecular compounds, which may provide new strategies for cancer treatment. Recent studies have reported that tumor cells undergoing epithelial-to-mesenchymal transition can be induced to differentiate into adipocytes. In this review, molecular mechanisms, signal pathways, and the roles of various biological processes in adipose differentiation are summarized. Understanding the molecular mechanism of adipogenesis and adipose differentiation of cancer cells may contribute to cancer treatments that involve inducing differentiation into benign cells.

RNA-Seq Analysis Identifies Differentially Expressed Genes Insubcutaneous Adipose Tissuein Qaidamford Cattle, Cattle-Yak, and Angus Cattle

Simple Summary

Fat content is an important factor affecting beef quality. Therefore, the screening and identification of differentially expressed genes in adipose tissue between different breeds (Qaidamford cattle, hybrid cattle-yak, and Angus cattle) by RNA high-throughput sequencing can provide useful information to the beef cattle industry. The aim of this work was to identify candidate genes of adipose tissue for future beef breeding efforts. Comparative analysis revealed a significant difference between hybrid cattle and Angus, but the difference between hybrid cattle varieties (cattle-yak vs. Qaidamford cattle) was not significant. Gene ontology (GO) and KEGG pathway enrichment analysis indicated that some differentially expressed genes are involved in lipid metabolism-related biological processes and signaling pathways associated with cell metabolism, such as extracellular matrix (ECM)-receptor interaction and the PI3K-Akt signal pathway. The expression levels of some of the identified genes were further verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). These data will be helpful for further investigations of meat quality and breeding efforts for different cattle breeds.

Abstract

In the beef industry, fat tissue is closely related to meat quality. In this study, high-throughput RNA sequencing was utilized for adipose tissue transcriptome analysis between cattle-yak, Qaidamford cattle, and Angus cattle. The screening and identification of differentially expressed genes (DEGs) between different breeds of cattle would facilitate cattle breeding. Compared to Angus cattle adipose tissue, a total of 4167 DEGs were identified in cattle-yak adipose tissue and 3269 DEGs were identified in Qaidamford cattle adipose tissue. Considering cattle-yak as a control group, 154 DEGs were identified in Qaidamford cattle adipose tissue. GO analysis indicated the significant enrichment of some DEGs related to lipid metabolism. The KEGG pathway database was also used to map DEGs and revealed that most annotated genes were involved in ECM-receptor interaction and the PI3K-Akt signal pathway, which are closely related to cell metabolism. Eight selected DEGs related to adipose tissue development or metabolism were verified by RT-qPCR, indicating the reliability of the RNA-seq data. The results of this comparative transcriptome analysis of adipose tissue and screening DEGs suggest several candidates for further investigations of meat quality in different cattle breeds.

ALDH1A1 effect on Yan Yellow Cattle preadipocyte differentiation

Aldehyde dehydrogenase 1A1 (ALDH1A1) is a cytosolic enzyme that mainly catalyzes the oxidation of acetaldehyde into acetic acid and participates in the regulation of differentiation and gene expression in fat cell growth and development. However, the physiological role of ALDH1A1 in the formation of fat cell precursors in the Yan Yellow Cattle is still not clear. Herein, we investigated the specific regulation of the gene encoding for ALDH1A1 during the differentiation process of the adipocyte cells of the Yan Yellow Cattle by interfering or overexpressing the ALDH1A1 gene. As a result, we found that the mRNA expression levels of ALDH1A1 were significantly increased during the formation of progenitor cells. In addition, the expression levels of the Lipoprotein lipase (LPL) and transcription factors (PPARγ, C/EBPα) were also significantly increased. ALDH1A1 gene overexpression and RNA interfering promoted and inhibited respectively the lipid accumulation and triglyceride production in mature adipocytes, and the expression of the LPL and transcription factors (PPARγ, C/EBPα). The changes in the protein expression levels of ALDH1A1 and adipogenic factors were in accord with the changes observed in the mRNA levels. In conclusion, our results indicate that ALDH1A1 plays an important regulatory role in the differentiation of preadipocyte cells.

IGFBP7 downregulation or overexpression effect on bovine preadipocyte differentiation

The insulin-like growth factor binding-protein 7 (IGFBP7) has binding affinities to IGFs and is able to either positively or negatively regulate the IGFs signaling pathway. It also plays a crucial role in cell growth, differentiation and development in an IGF-independent manner. Herein, we investigated the specific regulation of the gene encoding for IGFBP7during the differentiation process of the adipocyte cells of the Yan Yellow Cattle by interfering with or by overexpressing the IGFBP7 gene. As a result, we found that the mRNA expression levels of IGFBP7 were significantly increased during the formation of progenitor cells. In addition, the expression levels of the lipoprotein lipase (LPL) and transcription factors (PPARγ, C/EBPα) were also significantly increased. IGFBP7 gene overexpression and RNA interfering promoted and inhibited respectively the lipid accumulation and triglyceride production in mature adipocytes, and the expression of the LPL and transcription factors (PPARγ, C/EBPα). The changes in the protein expression levels of IGFBP7 and adipogenic factors were in accord with the changes observed in the mRNA levels. In conclusion, our results indicate that IGFBP7 plays an important regulatory role in the differentiation of preadipocyte cells.

Transcriptome Analysis of Differentially Expressed Genes Related to the Growth and Development of the Jinghai Yellow Chicken

The growth traits are important traits in chickens. Compared to white feather broiler breeds, Chinese local broiler breeds have a slow growth rate. The main genes affecting the growth traits of local chickens in China are still unclear and need to be further explored. This experiment used fast-growth and slow-growth groups of the Jinghai Yellow chicken as the research objects. Three males and three females with similar body weights were selected from the two groups at four weeks old and eight weeks old, respectively, with a total of 24 individuals selected. After slaughter, their chest muscles were taken for transcriptome sequencing. In the differentially expressed genes screening, all of the genes obtained were screened by fold change ≥ 2 and false discovery rate (FDR) < 0.05. For four-week-old chickens, a total of 172 differentially expressed genes were screened in males, where there were 68 upregulated genes and 104 downregulated genes in the fast-growth group when compared with the slow-growth group. A total of 31 differentially expressed genes were screened in females, where there were 11 upregulated genes and 20 downregulated genes in the fast-growth group when compared with the slow-growth group. For eight-week-old chickens, a total of 37 differentially expressed genes were screened in males. The fast-growth group had 28 upregulated genes and 9 downregulated genes when compared with the slow-growth group. A total of 44 differentially expressed genes were screened in females. The fast-growth group had 13 upregulated genes and 31 downregulated genes when compared with the slow-growth group. Through gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, many genes were found to be related to cell proliferation and differentiation, muscle growth, and cell division such as SNCG, MCL1, ARNTL, PLPPR4, VAMP1, etc. Real-time PCR results were consistent with the RNA-Seq data and validated the findings. The results of this study will help to understand the regulation mechanism of the growth and development of Jinghai Yellow chicken and provide a theoretical basis for improving the growth rate of Chinese local chicken breeds.

RNA-Seq analysis reveals a negative role of MSMO1 with a synergized NSDHL expression during adipogenesis of 3T3-L1

To investigate a comprehensive transcriptome information of adipogenesis, we assessed global changes in the transcriptional events during 3T3-L1 adipogenesis by RNA-Seq. Compared to the preadipocyte stage (day 0), gene expression profiling demonstrated that 2013 genes were up-regulated, and 2430 genes were down-regulated at the differentiated adipocyte stage (day 13). Among these differentially expressed genes, we found the expression of MSMO1 was down-regulated at day 13, but whether it impacts adipogenesis has not been characterized. Thus, we investigated its role in adipogenesis. Results showed that overexpression of MSMO1 inhibited the differentiation of 3T3-L1, and led to the down-regulated expression of adipogenic marker genes, while knockdown of MSMO1 had totally opposite effects. Furthermore, interaction network model allowed us to validate an unexpected role between MSMO1 and its partner, NSDHL, in regulating adipogenesis, which plays a synergized expression pattern with MSMO1. Our findings indicate that MSMO1 and NSDHL are novel modulators of adipogenesis.