modeling-adipocyte-insulin-resistance-using-mouse-subcutaneous

Modeling Adipocyte Insulin Resistance Using Mouse Subcutaneous Adipose Tissue-derived Stromal Vascular Fraction

Insulin resistance in adipose tissue is a central feature of metabolic disorders such as type 2 diabetes, yet many in vitro models rely on immortalized ...

This study aims to investigate the molecular mechanism of Adenovirus type 36 (Ad36) in adipocyte differentiation and glucolipid metabolism.

Adenovirus type 36 regulates adipose stem cell differentiation and glucolipid metabolism through the PI3K/Akt/FoxO1/PPARγ signaling pathway.

This study is to investigate the role of adenovirus 36 (Ad36) in regulating expression of peroxisome proliferator-activated receptor γ (PPARγ) and cell death-inducing DFFA-like effector c (CIDEC) in Ad36-induced adipocyte differentiation. Human adipose-derived mesenchymal stem cells (hAMSCs) were isolated and cultured, and then infected with Ad36. Ad36-induced adipocytes were identified using quantitative real-time PCR and Oil red O staining. The expression levels of PPARγ and CIDEC in Ad36-induced adipocytes were determined by quantitative real-time PCR and Western blot analysis. Glucose uptake and intracellular triglyceride content were also determined in these induced cells. Our results from the Oil red O staining showed that Ad36 induced the differentiation of hAMSCs into human adipocytes in vitro. Moreover, the medium glucose concentration was significantly decreased, while the intracellular triglyceride content was significantly increased, in the Ad36-induced adipocytes, compared with the control group. Furthermore, our results showed that, the mRNA and protein expression levels of PPARγ and CIDEC were significantly upregulated in Ad36-induced adipocytes, in a time-dependent manner. On the other hand, compared with the control group, the CIDEC expression was downregulated when the Ad36-induced adipocytes were treated with the PPARγ inhibitor, GW9662. Ad36 could upregulate the expression level of CIDEC through increasing PPARγ expression during the adipocyte differentiation process.

Regulation of PPARγ and CIDEC expression by adenovirus 36 in adipocyte differentiation.

To determine the role of lncRNA HOXA11-AS1 on adipocyte differentiation.

Effect of lncRNA HOXA11-AS1 on adipocyte differentiation in human adipose-derived stem cells.

This study is to investigate the role of adenovirus type 36 (Ad36) in inducing differentiation of human adipose-derived stem cells (hADSCs) into brown adipocytes.

Ad36 promotes differentiation of hADSCs into brown adipocytes by up-regulating LncRNA ROR.

Adipogenesis is regulated by genetic interactions, in which post-transcriptional regulation plays an important role. Staufen double-stranded RNA binding protein 1 (Staufen1 or ) plays diverse roles in RNA processing and adipogenesis. Previously, we found that the downregulation of  affects the expression of fatty acid-binding protein 4 (FABP4) at the protein level but not at the mRNA level. This study aimed to determine the mechanism underlying the regulation of FABP4 expression by STAU1, explaining the inconsistency between FABP4 mRNA and protein levels. We used RNA interference, photoactivatable ribonucleoside enhanced cross-linking and immunoprecipitation, and an adeno-associated virus to examine the functions of STAU1 in adipogenesis. Our results indicate that STAU1 binds to the coding sequences of , thereby regulating the translation of  mRNA by unwinding the double-stranded structure. Furthermore, STAU1 mediates adipogenesis by regulating the secretion of free fatty acids. However, STAU1 knockdown decreases the fat weight/body weight ratio but does not affect the plasma triglyceride levels. These findings describe the mechanisms involved in STAU1-mediated regulation of  expression at the translational level during adipogenesis.

Staufen1 unwinds the secondary structure and facilitates the translation of fatty acid binding protein 4 mRNA during adipogenesis.

During adipocyte differentiation, specific genes such as peroxisome proliferator-activated receptor γ (PPARγ) are transcribed and post-transcriptional pre-mRNA is processed into mature mRNA. Since Pparγ2 pre-mRNAs contain putative binding sites for STAUFEN1 (STAU1), which can affect the alternative splicing of pre-mRNA, we hypothesized that STAU1 might regulate the alternative splicing of Pparγ2 pre-mRNA. In this study, we found that STAU1 affects the differentiation of 3 T3-L1 pre-adipocytes. Through RNA-seq analysis, we confirmed that STAU1 can regulate alternative splicing events during adipocyte differentiation, mainly through exon skipping, which suggests that STAU1 is mainly involved in exon splicing. In addition, gene annotation and cluster analysis revealed that the genes affected by alternative splicing were enriched in lipid metabolism pathways. We further demonstrated that STAU1 can regulate the alternative splicing of Pparγ2 pre-mRNA and affect the splicing of exon E1 through RNA immuno-precipitation, photoactivatable ribonucleotide enhanced crosslinking and immunoprecipitation, and sucrose density gradient centrifugation assays. Finally, we confirmed that STAU1 can regulate the alternative splicing of Pparγ2 pre-mRNA in stromal vascular fraction cells. In summary, this study improves our understanding of the function of STAU1 in adipocyte differentiation and the regulatory network of adipocyte differentiation-related gene expression.

STAU1 promotes adipogenesis by regulating the alternative splicing of Pparγ2 mRNA.

In mammals, adipose tissue is involved in energy homeostasis regulation. White adipose tissue (WAT) is the major energy storage site for mammals, whereas brown adipose tissue (BAT) is involved in energy expenditure and thermogenesis. The conversion of triglycerides from WAT into fuel provides calories for the body and aids in reducing WAT accumulation, which is considered an effective strategy for weight loss and improving lipid metabolism. Regulation at the transcriptional level can determine the differentiation and transdifferentiation of WAT and BAT; however, post-transcriptional regulation offers an additional level of coordination to this process. Despite the high number of studies investigating the transcriptional regulatory mechanisms of key thermogenesis-regulated genes, the regulatory roles of these genes at the post-transcriptional level remain poorly understood. Therefore, this review summarizes the post-transcriptional regulatory mechanisms of key thermogenesis-regulated genes, including splicing, m6A modification, RNA degradation, RNA-binding proteins, and ncRNA regulation of pre-mRNAs of these thermogenic genes.

Article	Year
Adenovirus type 36 regulates adipose stem cell differentiation and glucolipid metabolism through the PI3K/Akt/FoxO1/PPARγ signaling pathway. Lipids in health and disease\| PubMed ID: 30902099	2019
Regulation of PPARγ and CIDEC expression by adenovirus 36 in adipocyte differentiation. Molecular and cellular biochemistry\| PubMed ID: 27995415	2017
Effect of lncRNA HOXA11-AS1 on adipocyte differentiation in human adipose-derived stem cells. Biochemical and biophysical research communications\| PubMed ID: 29217197	2018
Ad36 promotes differentiation of hADSCs into brown adipocytes by up-regulating LncRNA ROR. Life sciences\| PubMed ID: 33189825	2021
Staufen1 unwinds the secondary structure and facilitates the translation of fatty acid binding protein 4 mRNA during adipogenesis. Adipocyte\| PubMed ID: 34224297	2021
STAU1 promotes adipogenesis by regulating the alternative splicing of Pparγ2 mRNA. Biochimica et biophysica acta. Molecular and cell biology of lipids\| PubMed ID: 36871938	2023
Fine-tuning thermogenesis from the post-transcriptional level. iScience\| PubMed ID: 41467175	2025

Xiaodi Liang

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