Adipocyte最新文献

Oil Red O (ORO) staining is a commonly used experimental technique to detect lipid content in cells or tissues. Freshly prepared ORO in 60% isopropanol is the most widely used method at present. However, isopropanol is volatile and harmful to the human body. It will also affect the interpretation of the results due to the formation of crystals and non-specific diffuse staining. In this paper, by screening and validation, we report a salicylic acid ethanol solution (containing 50% ethanol, 5%-10% salicylic acid) for the preparation of ORO solution, which has a better staining effect on lipid staining in cells and tissues, with a clean background and short dyeing time. What's more, this ORO solution is non-toxic, convenient to prepare, and can be stored for a long time. Therefore, it is reliable, easy to operate, and can be widely popularized and applied in laboratories.

Ferroptosis is closely associated with the development of disease in the body. However, there are few studies on ferroptosis-related genes (FRGs) in obesity. Therefore, key genes and signalling pathways related to ferroptosis in obesity were screened. Briefly, the RNA sequencing data of obesity and the non-obesity human samples and 259 FRGs were downloaded from GEO database and FerrDb database, respectively. The obesity-related module genes were firstly screened by weighted gene co-expression network analysis (WGCNA) and crossed with differentially expressed genes (DEGs) of obesity/normal samples and FRGs to obtain obesity-ferroptosis related (OFR) DEGs. Then, key genes were screened by PPI network. Next, the correlation of key genes and differential immune cells between obesity and normal samples were further explored by immune infiltration analysis. Finally, microRNA (miRNA)-messenger RNA (mRNA), transcription factor (TF)-mRNA networks and drug-gene interaction networks were constructed. As a result, 17 OFR DEGs were obtained, which mainly participated in processes such as lipid metabolism or adipocyte differentiation. The 4 key genes, STAT3, IL-6, PTGS2, and VEGFA, constituted the network. M2 macrophages, T cells CD8, mast cells activated, and T cells CD4 memory resting had significant differences between obesity and normal samples. Moreover, 51 miRNAs and 164 drugs were predicted for 4 key genes. All in all, this study has screened 4 FRGs, including IL-6, VEGFA, STAT3, and PTGS2, in obesity patients.

The cytokine interleukin (IL)-27 has been reported to induce thermogenesis in white adipocytes. However, it remains unknown whether IL-27-mediated adipocyte energy dissipation is paralleled by an elevated energy supply from lipids and/or carbohydrates. We hypothesized that IL-27 increases lipolysis and glucose uptake in white adipocytes, thereby providing substrates for thermogenesis. Unexpectedly, we found that treatment of 3T3-L1 adipocytes with IL-27 reduced intra- and extracellular free fatty acid (FFA) concentrations and that phosphorylation of hormone-sensitive lipase (HSL) was not affected by IL-27. These results were confirmed in subcutaneous white adipocytes. Further, application of IL-27 to 3T3-L1 adipocytes increased intracellular triglyceride (TG) content but not mitochondrial ATP production nor expression of enzymes involved in beta-oxidation indicating that elevated esterification rather than oxidation causes FFA disappearance. In addition, IL-27 significantly increased GLUT1 protein levels, basal glucose uptake as well as glycolytic ATP production, suggesting that increased glycolytic flux due to IL-27 provides the glycerol backbone for TG synthesis. In conclusion, our findings suggest IL-27 increases glucose uptake and TG deposition in white adipocytes.

Alterations of the extracellular matrix contribute to adipose tissue dysfunction in metabolic disease. We studied the role of matrix density in regulating human adipocyte phenotype in a tunable hydrogel culture system. Lipid accumulation was maximal in intermediate hydrogel density of 5 weight %, relative to 3% and 10%. Adipogenesis and lipid and oxidative metabolic gene pathways were enriched in adipocytes in 5% relative to 3% hydrogels, while fibrotic gene pathways were enriched in 3% hydrogels. These data demonstrate that the intermediate density matrix promotes a more adipogenic, less fibrotic adipocyte phenotype geared towards increased lipid and aerobic metabolism. These observations contribute to a growing literature describing the role of matrix density in regulating adipose tissue function.

Exercise is a universally acknowledged and healthy way to reducing body weight. However, the roles and mechanisms of exercise on metabolism of adipose tissue remain largely unclear. Adipose tissues include white adipose tissue (WAT), brown adipose tissue (BAT) and beige adipose tissue (BeAT). The main function of WAT is to store energy, while the BAT and BeAT can generate heat and consume energy. Therefore, promotion of BAT activation and WAT browning contributes to body weight loss. To date, many studies have suggested that exercise exerts the potential regulatory effects on BAT activation and WAT browning. In the present review, we compile the evidence for the regulatory effects of exercise on BAT activation and WAT browning and summarize the possible mechanisms whereby exercise modulates BAT activation and WAT browning, including activating sympathetic nervous system (SNS) and promoting the secretion of exerkines, with special focus on exerkines. These data might provide reference for prevention or treatment of obesity and the related metabolic disease through exercise.

This study aimed to observe the expression of insulin-signaling molecules in different organs of mice with insulin resistance (IR). Firstly, mice were fed a high-fat and high-sugar diet (HF group) to establish an IR model, and the controls (NF group) were fed with a normal diet. Next, the weight, fasting blood glucose (FBG), serum insulin and insulin tolerance were detected. Pathological changes of liver tissues were observed by H&E staining. The expressions of INSR, IRS-1 and IRS-2 in the liver, skeletal muscle and ovary were measured by qRT-PCR and western blotting. As a result, compared with the NF group, the HF group mice had increased weight, FBG, insulin and IR index after 6-week of feeding as well as a worse performance in the insulin tolerance test and H&E staining showed fatty liver-like changes after 12-week of feeding, exhibited lower expression of INSR, IRS-1 and IRS-2 in the liver of mice at 6 and 12 weeks. The expression of INSR and IRS-1 in skeletal muscle tissues exhibited the same trend, while those in ovary organs showed the opposite trend. These results suggested that the insulin signaling alters in the liver, skeletal muscle and ovary organs with the progress of IR.

The renin-angiotensin system (RAS) operates within adipose tissue. Obesity-related changes can affect adipose RAS, predisposing to hypertension, type 2 diabetes, and possibly severe COVID-19. We evaluated the in vitro research on human adipose RAS and identified gaps in the literature. Medline (Ovid), Embase (Ovid), Web of Science, Scopus, and 1findr were searched to identify relevant studies. Fifty primary studies met our inclusion criteria for analysis. Expression of RAS components (n = 14), role in differentiation (n = 14), association with inflammation (n = 15) or blood pressure (n = 7) were investigated. We found (1) obesity-related changes in RAS were frequently studied (30%); (2) an upswing of articles investigating adipose ACE-2 expression since the COVID-19 pandemic; (3) a paucity of papers on AT2R and Ang (1-7)/MasR which counterbalance Ang II/ART1; (4) weight loss lowered adipose ACE-2 mRNA expression; and (5) angiotensin receptor blockers (ARBs) reduced deleterious effects of angiotensin II. Overall, these studies link Ang II/ATR1 signalling to impaired adipogenesis and a pro-inflammatory dysfunctional adipose tissue, with ATR1 blockade limiting these responses. ACE-2 may mitigate Ang II effects by converting it to Ang(1-7) which binds MasR. More work is needed to understand adipose RAS in various pathologic states such as obesity and COVID-19 infection.T.

Background: Mature adipocytes are notoriously difficult to study ex vivo and alternative cell culture systems have therefore been developed. One of the most common models are human adipose progenitor cells (hAPCs). Unfortunately, these display replicative senescence after prolonged culture conditions, which limits their use in mechanistic studies.

Methods: Herein, we knocked in human telomerase reverse transcriptase (TERT) into the AAVS1 locus of CD55⁺ hAPCs derived from abdominal subcutaneous adipose tissue and characterized the cells before and after differentiation into adipocytes.

Results: Immortalized TERT-hAPCs retained proliferative and adipogenic capacities comparable to those of early-passage wild type hAPCs for > 80 passages. In line with this, our integrative transcriptomic and proteomic analyses revealed that TERT-hAPCs displayed robust adipocyte expression profiles in comparison to wild type hAPCs. This was confirmed by functional analyses of lipid turnover where TERT-hAPCs exhibited pronounced responses to insulin and pro-lipolytic stimuli such as isoprenaline, dibutyrul cAMP and tumour necrosis factor alpha. In addition, TERT-hAPCs could be readily cultured in both standard 2D and 3D-cultures and proteomic analyses revealed that the spheroid culture conditions improved adipogenesis.

Conclusion: Through descriptive and functional studies, we demonstrate that immortalization of human CD55⁺ hAPCs is feasible and results in cells with stable proliferative and adipogenic capacities over multiple passages. As these cells are cryopreservable, they provide the additional advantage over primary cells of allowing repeated studies in both 2D and 3D model systems with the same genetic background. (234/250).

Introduction: Mitochondria are essential for generating cellular energy and are significant in the pathogenesis of obesity. Peptide PDBSN has been demonstrated to inhibit the adipogenic differentiation of adipocytes in vitro and improves metabolic homoeostasis in vivo. Therefore, in this study, we further investigated the effects of PDBSN on the morphology, synthesis, and function of adipocyte mitochondria. Methods: Human visceral and subcutaneous primary preadipocytes (HPA-v and HPA-s) were cultured into mature adipocytes. Intracellular triglyceride content was assessed using oil-red O staining and tissue triglyceride determination. Gene and protein levels associated with mitochondrial synthesis were detected using real-time quantitative polymerase chain reaction and western blotting. Mitochondrial membrane potentials and ROS were detected using fluorescent indicators. Morphological changes were observed by electron microscopy. Results: PDBSN significantly increased mitochondrial membrane potential (MMP), while decreasing intracellular triglyceride (TG) and intracellular reactive oxygen species (ROS) levels. On the other hand, the transcription and protein levels of genetic marker genes PGC1-α and MTFA were significantly up-regulated after PDBSN administration. Further studies showed that transcriptional and protein levels of mitochondrial fusion and fission genetic markers MFN1, MFN2, NRF1, and DRP1 increased. Conclusion: PDBSN significantly reduces intracellular TG and ROS levels and increases MMP. The maximum respiratory capacity in adults significantly increases after PDBSN administration, and ROS levels are significantly reduced. This suggests that PDBSN improves mitochondrial function to some extent, which not only provides an essential basis for the pathophysiology of obesity but also provides insights for the development of new drugs to treat obesity and metabolic diseases.

Increasing studies have identified the potential of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) in non-alcoholic fatty liver disease (NAFLD) treatment. Hence, we further focused on the potential of adipose-derived MSC (ADSC)-EVs in NAFLD by delivering miR-223-3p. The uptake of isolated ADSC-EVs by hepatocytes was assessed, and the expression of miR-223-3p in ADSC-EVs and hepatocytes was characterized. It was established that miR-223-3p, enriched in ADSC-EVs, could be delivered by ADSC-EVs into hepatocytes. Using co-culture system and gain-of-function approach, we evaluated the effect of ADSC-EVs carrying miR-223-3p on lipid accumulation and liver fibrosis in pyrrolizidine alkaloids (PA)-induced hepatocytes and a high-fat diet-induced NAFLD mouse model. Bioinformatics websites and dual-luciferase reporter gene assay were performed to determine the interactions between miR-223-3p and E2F1, which was further validated by rescue experiments. ADSC-EVs containing miR-223-3p displayed suppressive effects on lipid accumulation and liver fibrosis through E2F1 inhibition, since E2F1 was demonstrated as a target gene of miR-223-3p. The protective role of ADSC-EVs by delivering miR-223-3p was then confirmed in the mouse model. Collectively, this study elucidated that ADSC-EVs delayed the progression NAFLD through the delivery of anti-fibrotic miR-223-3p and subsequent E2F1 suppression, which may suggest miR-223-3p-loaded ADSC-EVs to be a potential therapeutic approach for NAFLD.