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Tumor necrosis factor alpha (TNF-α)/hypoxia-treated 3T3-L1 adipocytes have been used to model inflamed and insulin-resistant adipose tissue: this study examines gaps in the model. We tested whether modulating TNF-α/hypoxia treatment time could reduce cell death while still inducing inflammation and insulin resistance. Adipocytes were treated with TNF-α (12 h or 24 h) and incubated in a hypoxic chamber for 24 h. To examine maintenance of the phenotype over time, glucose and FBS were added at 24 h post initiation of treatment, and the cells were maintained for an additional 48 h. Untreated adipocytes were used as a control. Viability, insulin resistance, and inflammation were assessed using Live/Dead staining, RT-qPCR, ELISA, and glucose uptake assays. Treatment for 12 h with TNF-α in the presence of hypoxia resulted in an increase in the percentage of live cells compared to 24 h treated cells. Importantly, insulin resistance and inflammation were still induced in the 12 h treated adipocytes: the expression of the insulin sensitive and inflammatory genes was decreased and increased, respectively. In 72 h treated adipocytes, no significant differences were found in the viability, glucose uptake or insulin-sensitive and inflammatory gene expression. This study provides a modified approach to in vitro odeling adipocyte inflammation and insulin resistance. [ABSTRACT FROM AUTHOR]

Objective To explore the effect of different concentrations of olanzapine on secretion of inflammatory cytokines in adipocytes. Methods 3T3-L1 cells were induced to mature adipocytes using 3-Isobutyl-1-methylxanthine, dexamethasone, and insulin. And then, mature adipocytes were randomly divided into the experiment group 1, experiment group 2, experiment group 3 and control group, respectively. Cells in the experiment groups were intervened with 2. 5, 5. 0, and 10 µmol/L olanzapine, respectively. Cells in the control group were cultured normally without olanzapine. We collected the supernatants of the cell culture medium after intervention for 12, 24, 48 and 72 h, respectively. The levels of inflammatory cytokines, interleukin-6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor-α (TNF-α) were measured by ELISA. Results IL-6 and IL-10 in culture supernatant of mature adipocytes in all experiment groups increased over the intervention time (all P<0. 05). The expression of IL-6 was higher in all experiment groups at 72 h after olanzapine treatment in comparison with that of the control group; that was higher in the experiment group 2 than in the experiment group 1 and experiment group 3 at 72 h after olanzapine treatment (all P<0. 05). The expression levels of IL-10 were lower in the experiment group 1 and experiment group 2 than in the control group after olanzapine intervention for 48 or 72 h, and the expression of IL-10 was lower in the experiment group 3 than in the control group after olanzapine intervention for 72 h (all P<0. 05); the expression of IL-10 was lower in the experiment group 1 and experiment group 2 than in the experiment group 3 after olanzapine intervention for 72 h (both P<0. 05) . However, the absorbance values of TNF-α in the supernatants of the cell culture medium at different time points of intervention in each group were all relatively low, and it was not possible to calculate and obtain the concentrations according to the standard curve method. Conclusions Olanzapine can promote the secretion of pro-inflammatory cytokines IL-6 and inhibit the secretion of anti-inflammatory cytokines IL-10. These effects may be related to the occurrence of obesity in patients with schizophrenia treated by olanzapine. [ABSTRACT FROM AUTHOR]

Flavanones, a class of flavonoids, are abundant in fruits, vegetables, and herbs. They are known to have several biological activities, such as anti-inflammatory and anti-cancer activities, but their effects on obesity remain unclear. Obesity is closely associated with adipocyte differentiation and lipid accumulation in adipose tissue. Therefore, in this study, we examined the effects of flavanone derivatives on adipocyte differentiation and lipid accumulation by using 3T3-L1 cells. Among the 15 flavanone derivatives studied, 4′-phenylflavanone (4PF), with a biphenyl structure, significantly inhibited adipocyte differentiation-related lipid accumulation in 3T3-L1 cells; this inhibition of lipid accumulation was dose-dependent. Gene expression analysis showed that 4PF suppressed the expression of adipogenic marker genes. Although the induction of peroxisome proliferator activator γ2 (Pparγ2), a master regulator of adipocyte differentiation, and its target genes during adipocyte differentiation was attenuated in 4PF-treated cells, 4PF did not directly regulate Pparγ2 gene expression and its activation. In contrast, 4PF suppressed mitotic clonal expansion (MCE), which is associated with changes in the expression of proliferation-related genes at the early stages of adipocyte differentiation. Taken together, these results suggest that 4PF inhibits lipid accumulation because it suppresses MCE during adipocyte differentiation. Thus, our findings may help in the development of anti-obesity drugs. [ABSTRACT FROM AUTHOR]

White adipose tissue (WAT) is essential for lipid storage and systemic energy homeostasis. Understanding adipocyte formation and stability is key to developing therapies for obesity and metabolic disorders. Through a high-throughput cDNA screen, we identified PATZ1, a POZ/BTB and AT-Hook Containing Zinc Finger 1 protein, as an important adipogenic transcription factor. PATZ1 is expressed in human and mouse adipocyte precursor cells (APCs) and adipocytes. In cellular models, PATZ1 promotes adipogenesis via protein-protein interactions and DNA binding. PATZ1 ablation in mouse adipocytes and APCs leads to a reduced APC pool, decreased fat mass, and hypertrophied adipocytes. ChIP-Seq and RNA-seq analyses show that PATZ1 supports adipogenesis by interacting with transcriptional machinery at the promoter regions of key early adipogenic factors. Mass-spec results show that PATZ1 associates with GTF2I, with GTF2I modulating PATZ1's function during differentiation. These findings underscore PATZ1's regulatory role in adipocyte differentiation and adiposity, offering insights into adipose tissue development.

Background: The leaves of the olive plant (Olea europaea) contain significantly higher levels of phenolic compounds than the fruit and olive oil, acting as a natural supplement for antioxidant activities. Objectives: This research aimed to investigate the effect of this extract on certain inflammatory factors (TNF-α, IL-1, IL-6) and its regulatory role on tissue gene (RBP4) in fibroblast cell lines (3T3-L1). Methods: After culturing adipose tissue fibroblast cells (3T3-L1) under sterile and standard conditions, the cells were exposed to different logarithmic concentrations of the extract. The production of inflammatory cytokines TNF-α, IL-1, and IL-6 was measured using ELISA methods, and the expression level of the RBP4 gene was assessed using a real-time PCR technique. Results: The results showed dose-dependent effects of the extract on the 3T3-L1 cells. The MTT assay indicated that the hydroalcoholic extract of olive plant leaves has a concentration-dependent effect on cell proliferation (∗∗P ≤ 0.05). The DPPH test results showed a significant decrease in the level of active oxygen in the presence of Olive leaf extract (OLE). The catalase and MDA test results also indicated an increase in antioxidant activity in cells treated with the extract. Conversely, the expression levels of inflammatory cytokines IL-1 and IL-6 increased by 0.05 and 0.01 (pg/mL), respectively, while changes in TNF-α and RBP4 gene expression were insignificant (P > 0.05). Conclusions: The results demonstrated that OLE can enhance the efficiency of antioxidant and inflammatory pathways in the cell and significantly reduce the level of active oxygen in the cell. [ABSTRACT FROM AUTHOR]

ATAD3 is a vital ATPase of the inner mitochondrial membrane of pluri‐cellular eukaryotes, with largely unknown functions but early required for organism development as necessary for mitochondrial biogenesis. ATAD3 knock‐down in C. elegans inhibits at first the development of adipocyte‐like intestinal tissue so we used mouse adipocyte model 3T3‐L1 cells to analyze ATAD3 functions during adipogenesis and lipogenesis in a mammalian model. ATAD3 function was studied by stable and transient modulation of ATAD3 expression in adipogenesis‐ induced 3T3‐L1 cells using Knock‐Down and overexpression strategies, exploring different steps of adipocyte differentiation and lipogenesis. We show that (i) an increase in ATAD3 is preceding differentiation‐induced mitochondrial biogenesis; (ii) downregulation of ATAD3 inhibits adipogenesis, lipogenesis, and impedes overexpression of many mitochondrial proteins; (iii) ATAD3 re‐expression rescues the phenotype of ATAD3 KD, and (iv) differentiation and lipogenesis are accelerated by ATAD3 overexpression, but inhibited by expression of a dominant‐negative mutant. We further show that the ATAD3 KD phenotype is not due to altered insulin signal but involves a limitation of mitochondrial biogenesis linked to Drp1. These results demonstrate that ATAD3 is limiting for in vitro mitochondrial biogenesis and adipogenesis/lipogenesis and therefore that ATAD3 mutation/over‐ or under‐expression could be involved in adipogenic and lipogenic pathologies. [ABSTRACT FROM AUTHOR]

The global prevalence of obesity is rising year by year, which has become a public health problem worldwide. Many animal and clinical studies have shown that Lactiplantibacillus plantarum is considered an ideal probiotic and potential supplement for the treatment of obesity. In this study, we aimed to complete the genome sequence of L. plantarum HOM2217, which was isolated from human milk, and study its physiological characteristics and anti-obesity effects in 3T3-L1 cells and rats fed a high-fat diet (HFD) to determine its potential as a starter for functional food products. Whole-genome analysis demonstrated that HOM2217 contained a single circular chromosome of 3,267,529 bp with a GC content of 44.5% and one plasmid (62,350 bp) with a GC content of 38.5%. Compared to the reference strains, HOM2217 demonstrated superior tolerance to gastrointestinal conditions, higher adhesion to intestinal epithelial cell lines, potent antimicrobial activity against Enterobacter cloacae ATCC 13047, and effective cholesterol removal ability in vitro. Treatment with heat-killed HOM2217 significantly reduced lipid accumulation and intracellular triglyceride production in 3T3-L1 adipocytes. Daily treatment of HFD-fed rats with HOM2217 for 7 weeks decreased body weight, body weight gain, and body fat without changes in food intake. HOM2217 also significantly increased the serum high-density lipoprotein cholesterol (HDL-C) level, decreased the serum tumor necrosis factor (TNF-a) and increased short-chain fatty acid (SCFA) (formic acid, acetic acid, and butyric acid) levels in the cecum. Thus, HOM2217 could potentially prevent obesity in rats by inhibiting inflammatory responses and regulating lipid metabolism and SCFAs expression. Therefore, HOM2217 has potential as an alternative treatment for obesity. [ABSTRACT FROM AUTHOR]

Notwithstanding the several investigations of the hydroxy fatty acids (hFAs)' physiological functions, studies focusing on their anti-obesity effects are limited. This study investigated the anti-obesity effects of 4 hFAs—10-hydroxy stearic acid (10-hSA), 12-hydroxy stearic acid (12-hSA), 9,12-hydroxy stearic acid (9,12-dhSA), and 12-hydroxy oleic acid (12-hOA)—on the 3T3-L1 cells. All hFAs suppressed lipid accumulation, with 10-hSA and 12-hOA exhibiting the strongest suppression, followed by 12-hSA and 9,12-hSA. This trend was similar to that observed for the glycerol-3-phosphate dehydrogenase (GPDH) activity level. Contrastingly, only 9,12-dhSA suppressed cell viability. The mRNA levels of HK1 and Aldoa were markedly suppressed by 10-hSA and 12-hSA compared to the control. Additionally, mRNA expression of Gyk was considerably suppressed by 12-hSA. Thus, all hFAs suppressed lipid accumulation by suppressing GPDH activity, although their molecular mechanisms were different. These findings will aid the application of hFAs in the food and medical industries. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the effects of low‐intensity pulsed ultrasound (LIPUS) on the proliferation, differentiation, and tumor necrosis factor‐α (TNF‐α)‐induced lipolysis of 3T3‐L1 cells, and to explore the feasibility of regulating the release of free fatty acids (FFA) to prevent lipotoxicity. Methods: Different intensities (30, 60, 90, and 120 mW/cm2) of LIPUS were applied to 3T3‐L1 preadipocytes for different durations (5, 10, 15, 20, 25, and 30 minutes). Appropriate parameters for subsequent experiments were selected by assessing cell viability. The effect of LIPUS on the proliferation and differentiation of 3T3‐L1 cells was evaluated by microscope observation, flow cytometry, and lipid content determination. After treated with LIPUS and TNF‐α (50 ng/mL), the degree of lipolysis was assessed by measuring the extracellular FFA content. Quantitative real‐time polymerase chain reaction (qRT‐PCR) was used to detect the mRNA expression of relevant genes. Results: Different parameters of LIPUS significantly enhance the viability of 3T3‐L1 cells (P <.05), with 20 minutes and 30 mW/cm2 as the most suitable settings. After LIPUS treatment, 3T3‐L1 cell proliferation accelerated, apoptosis rate and G1 phase cell proportion decreased, the content of lipid droplets and TG was increased in differentiated cells, while FFA release decreased (P <.05). The expression of PCNA, PPARγ, C/EBPα, Perilipin A mRNA increased, and the expression of TNF‐α, ATGL, HSL mRNA decreased (P <.05). Conclusions: LIPUS could promote the proliferation and differentiation of 3T3‐L1 cells and inhibit TNF‐α‐induced lipolysis, indicating its potential as a therapy for mitigating lipotoxicity caused by decompensated adipocytes. [ABSTRACT FROM AUTHOR]

IntroductionThe plasma membrane-bound protein, multi-drug resistance-associated protein 4 (MRP4/ABCC4), has gained attention for its pivotal role in facilitating the efflux of a wide range of endogenous and xenobiotic molecules. Its significance in adipogenesis and fatty acid metabolism has been brought to light by recent studies. Notably, research on ABCC4 knockout (ABCC4−/−) mice has established a link between the absence of ABCC4 and the development of obesity and diabetes. Nevertheless, the specific contribution of ABCC4 within adipose tissue remains largely unexplored.MethodsTo address this gap, we conducted a study to elucidate the role of the ABCC4 transporter in mature adipocytes, using siRNA constructs to silence its gene function.ResultsThe successful knockdown of ABCC4 significantly altered lipid status and adipogenic gene expression in mature 3T3-L1 adipocytes. Intriguingly, this knockdown also altered the gene expression patterns of other ABCC transporter family members in 3T3-L1 cells. The downregulation of ABCC5 expression was particularly noteworthy, suggesting potential crosstalk between ABCC transporters in mature adipocytes. Additionally, knocking down ABCC5 resulted in significantly higher adipogenic and lipogenic gene expression levels. Oil Red O staining confirmed increased lipid accumulation following the knockdown of ABCC4 and ABCC5. Surprisingly, the simultaneous knockdown of both transporters did not show a cumulative effect on adipogenesis, rather it led to higher levels of intracellular cAMP and extracellular prostaglandin metabolite, both of which are essential signaling molecules in adipogenesis.ConclusionThese results highlight the complex interplay between ABCC4 and ABCC5 transporters in adipocyte function and suggest their individual contributions toward obesity and related disorders.

Obesity is a significant risk factor for the development of type 2 diabetes due to its association with increased oxidative stress and inflammation. This study investigates the potential therapeutic effects of butein, a plant-derived polyphenol used as a dietary supplement, on adipogenic differentiation in 3T3-L1 cells, as well as its effects on inflammation and glucose metabolism in co-cultured 3T3-L1 and RAW264 cells treated with lipopolysaccharide (LPS). While butein did not significantly affect lipid accumulation in adipocytes, it significantly upregulated the mRNA expression of genes involved in adipogenic differentiation. In addition, butein demonstrated the ability to reduce reactive oxygen species levels in adipocytes. In co-culture with LPS-stimulated cells, butein exhibited anti-inflammatory properties by suppressing the expression of pro-inflammatory cytokines. Although its efficacy in reversing LPS-induced glucose metabolism in 3T3-L1 adipocytes was limited, butein significantly inhibited GLUT1 expression in LPS-stimulated RAW264 cells. The effects of butein on adipogenic differentiation, inflammation and glucose metabolism were found to be concentration dependent, suggesting potential protective benefits in co-cultured cell models under LPS stimulation.

Tumor necrosis factor alpha (TNF-α)/hypoxia-treated 3T3-L1 adipocytes have been used to model inflamed and insulin-resistant adipose tissue: this study examines gaps in the model. We tested whether modulating TNF-α/hypoxia treatment time could reduce cell death while still inducing inflammation and insulin resistance. Adipocytes were treated with TNF-α (12 h or 24 h) and incubated in a hypoxic chamber for 24 h. To examine maintenance of the phenotype over time, glucose and FBS were added at 24 h post initiation of treatment, and the cells were maintained for an additional 48 h. Untreated adipocytes were used as a control. Viability, insulin resistance, and inflammation were assessed using Live/Dead staining, RT-qPCR, ELISA, and glucose uptake assays. Treatment for 12 h with TNF-α in the presence of hypoxia resulted in an increase in the percentage of live cells compared to 24 h treated cells. Importantly, insulin resistance and inflammation were still induced in the 12 h treated adipocytes: the expression of the insulin sensitive and inflammatory genes was decreased and increased, respectively. In 72 h treated adipocytes, no significant differences were found in the viability, glucose uptake or insulin-sensitive and inflammatory gene expression. This study provides a modified approach to in vitro odeling adipocyte inflammation and insulin resistance.

Objective: The study was designed to test solvent extracts of Rubus suavissimus (RS) for compounds that regulate lipid metabolism and to measure their relative activity as quantitative markers of lipid metabolism-regulating activities based on the spectrum-effect relationship. Method: RS was extracted with 95% ethanol, the different extraction parts were successively extracted with petroleum ether, methylene chloride, ethyl acetate and n-butanol, respectively. The solution of different extraction parts was applied to the induced differentiated 3T3-L1 preadipocytes, and the oil red O staining and triglyceride release from the cells were determined to screen the best metabolism-regulating site. Analysis of different extraction sited by UPLC-Q-TOF-MS/MS technique to separate and identify the components. Based on specific assays, image intensity analysis, grey correlation and partial least squares regressions, the spectrum-effect relationship of the most abundant active components and their ability to regulate lipid metabolism were determined, and the quality markers were screened. Results: Ethyl acetate and n-butanol extraction site was the best metabolism-regulating site. Four components, including ellagic acid, centaurin-3-O-rutinoside, rubusoside and enantio-kauri-16-ene-19-carboxylic acid-13-O-β-D-glucoside were highly associated with metabolism-regulating effects. It could be used as quality markers for regulating lipid metabolism. Conclusion: Investigation of the quality markers of RS extracts based on the spectrum-effect relationship is of great importance for elucidating the pharmacodynamics, screening the core quality markers for therapeutic activity, and ensuring the safety and rational application of traditional medicines.

Objective: The study was designed to test solvent extracts of Rubus suavissimus (RS) for compounds that regulate lipid metabolism and to measure their relative activity as quantitative markers of lipid metabolism-regulating activities based on the spectrum-effect relationship. Method: RS was extracted with 95% ethanol, the different extraction parts were successively extracted with petroleum ether, methylene chloride, ethyl acetate and n-butanol, respectively. The solution of different extraction parts was applied to the induced differentiated 3T3-L1 preadipocytes, and the oil red O staining and triglyceride release from the cells were determined to screen the best metabolism-regulating site. Analysis of different extraction sited by UPLC-Q-TOF-MS/MS technique to separate and identify the components. Based on specific assays, image intensity analysis, grey correlation and partial least squares regressions, the spectrum-effect relationship of the most abundant active components and their ability to regulate lipid metabolism were determined, and the quality markers were screened. Results: Ethyl acetate and n-butanol extraction site was the best metabolism-regulating site. Four components, including ellagic acid, centaurin-3-O-rutinoside, rubusoside and enantio-kauri-16-ene-19-carboxylic acid-13-O-β-D-glucoside were highly associated with metabolism-regulating effects. It could be used as quality markers for regulating lipid metabolism. Conclusion: Investigation of the quality markers of RS extracts based on the spectrum-effect relationship is of great importance for elucidating the pharmacodynamics, screening the core quality markers for therapeutic activity, and ensuring the safety and rational application of traditional medicines. [ABSTRACT FROM AUTHOR]

Abstract Interleukin-33 (IL-33), an emerging cytokine within the IL-1 family, assumes a pivotal function in the control of obesity. However, the specific mechanism of its regulation of obesity formation remains unclear. In this study, we found that the expression level of IL-33 increased in visceral adipose tissue in mice fed with a high-fat diet (HFD) compared with that in mice fed with a normal diet (ND). In vitro, we also found the expression level of IL-33 was upregulated during the adipogenesis of 3T3-L1 cells. Functional test results showed that knockdown of IL-33 in 3T3-L1 cells differentiation could promote the accumulation of lipid droplets, the content of triglyceride and the expression of adipogenic–related genes (i.e. PPAR-γ, C/EBPα, FABP4, LPL, Adipoq and CD36). In contrast, overexpression of IL-33 inhibits adipogenic differentiation. Meanwhile, the above tests were repeated after over-differentiation of 3T3-L1 cells induced by oleic acid, and the results showed that IL-33 played a more significant role in the regulation of adipogenesis. To explore the mechanism, transcriptome sequencing was performed and results showed that IL-33 regulated the PPAR signaling pathway in 3T3-L1 cells. Further, Western blot and confocal microscopy showed that the inhibition of IL-33 could promote PPAR-γ expression by inhibiting the Wnt/β-catenin signal in 3T3-L1 cells. This study demonstrated that IL-33 was an important regulator of preadipocyte differentiation and inhibited adipogenesis by regulating the Wnt/β-catenin/PPAR-γ signaling pathway, which provided a new insight for further research on IL-33 as a new intervention target for metabolic disorders.

Objective: To investigate the active components, protein targets, and mechanisms underlying the anti-obesity effects of Hippophae fructus using network pharmacology and molecular docking techniques, and to validate its in vitro anti-obesity efficacy. Methods: The TCMSP platform was utilized to retrieve the active components and targets of Hippophae fructus, and disease targets were collected. Venny 2.0.2 was used to identify the intersection of targets between Hippophae fructus and obesity-related targets. The STRING database was used to establish a drug-target-disease protein interaction (PPI) network. The intersecting targets were analyzed using the David database to perform GO enrichment analysis and KEGG pathway analysis. Cytoscape 3.9.1 was used to construct a network diagram of the components of Hippophae fructus, anti-obesity targets, and related signaling pathways. Autodock Dock 1.5.7 and Pymol 2.2.0 were used to carry out molecular docking between the core targets of Hippophae fructus and its components, followed by visualization. The in vitro anti-obesity effect of Hippophae fructus extract was evaluated through cell experiments using 3T3-L1 cells. Results: A total of 33 active components, 2820 disease targets, and 151 intersection targets of Hippophae fructus were identified. The main active components included flavonoids, vitamins, and sterols, while key targets involved AKT1, TNF, IL6, TP53, VEGFA, CASP3, and others. KEGG pathway enrichment analysis revealed 131 signaling pathways, including those related to malignant tumors, lipid and atherosclerosis, and AGE-RAGE signaling. Molecular docking results demonstrated favorable binding interactions between the core targets and the corresponding active components of Hippophae fructus. The in vitro experiments indicated that Hippophae fructus extract exhibited inhibitory effects on the proliferation of 3T3-L1 pre-adipocytes. Conclusion: This study reveals that Hippophae fructus exerts anti-obesity effects through multiple components, targets, and pathways, providing valuable insights for its clinical research and product development.

Flavanones, a class of flavonoids, are abundant in fruits, vegetables, and herbs. They are known to have several biological activities, such as anti-inflammatory and anti-cancer activities, but their effects on obesity remain unclear. Obesity is closely associated with adipocyte differentiation and lipid accumulation in adipose tissue. Therefore, in this study, we examined the effects of flavanone derivatives on adipocyte differentiation and lipid accumulation by using 3T3-L1 cells. Among the 15 flavanone derivatives studied, 4′-phenylflavanone (4PF), with a biphenyl structure, significantly inhibited adipocyte differentiation-related lipid accumulation in 3T3-L1 cells; this inhibition of lipid accumulation was dose-dependent. Gene expression analysis showed that 4PF suppressed the expression of adipogenic marker genes. Although the induction of peroxisome proliferator activator γ2 (Pparγ2), a master regulator of adipocyte differentiation, and its target genes during adipocyte differentiation was attenuated in 4PF-treated cells, 4PF did not directly regulate Pparγ2 gene expression and its activation. In contrast, 4PF suppressed mitotic clonal expansion (MCE), which is associated with changes in the expression of proliferation-related genes at the early stages of adipocyte differentiation. Taken together, these results suggest that 4PF inhibits lipid accumulation because it suppresses MCE during adipocyte differentiation. Thus, our findings may help in the development of anti-obesity drugs.

Tipepidine (3-[di-2-thienylmethylene]-1-methylpiperidine) (TP) is a non-narcotic antitussive used in Japan. Recently, the potential application of TP in the treatment of neuropsychiatric disorders, such as depression and attention deficit hyperactivity disorder, has been suggested; however, its functions in energy metabolism are unknown. Here, we demonstrate that TP exhibits a metabolism-improving action. The administration of TP reduced high-fat diet-induced body weight gain in mice and lipid accumulation in the liver and increased the weight of epididymal white adipose tissue (eWAT) in diet-induced obese (DIO) mice. Furthermore, TP inhibited obesity-induced fibrosis in the eWAT. We also found that TP induced AMP-activated protein kinase (AMPK) activation in the eWAT of DIO mice and 3T3-L1 cells. TP-induced AMPK activation was abrogated by the transfection of liver kinase B1 siRNA in 3T3-L1 cells. The metabolic effects of TP were almost equivalent to those of metformin, an AMPK activator that is used as a first-line antidiabetic drug. In summary, TP is a potent AMPK activator, suggesting its novel role as an antidiabetic drug owing to its antifibrotic effect on adipose tissues. [ABSTRACT FROM AUTHOR]

Objective: To investigate the active components, protein targets, and mechanisms underlying the anti-obesity effects of Hippophae fructus using network pharmacology and molecular docking techniques, and to validate its in vitro anti-obesity efficacy. Methods: The TCMSP platform was utilized to retrieve the active components and targets of Hippophae fructus, and disease targets were collected. Venny 2.0.2 was used to identify the intersection of targets between Hippophae fructus and obesity-related targets. The STRING database was used to establish a drug-target-disease protein interaction (PPI) network. The intersecting targets were analyzed using the David database to perform GO enrichment analysis and KEGG pathway analysis. Cytoscape 3.9.1 was used to construct a network diagram of the components of Hippophae fructus, anti-obesity targets, and related signaling pathways. Autodock Dock 1.5.7 and Pymol 2.2.0 were used to carry out molecular docking between the core targets of Hippophae fructus and its components, followed by visualization. The in vitro anti-obesity effect of Hippophae fructus extract was evaluated through cell experiments using 3T3-L1 cells. Results: A total of 33 active components, 2820 disease targets, and 151 intersection targets of Hippophae fructus were identified. The main active components included flavonoids, vitamins, and sterols, while key targets involved AKT1, TNF, IL6, TP53, VEGFA, CASP3, and others. KEGG pathway enrichment analysis revealed 131 signaling pathways, including those related to malignant tumors, lipid and atherosclerosis, and AGE-RAGE signaling. Molecular docking results demonstrated favorable binding interactions between the core targets and the corresponding active components of Hippophae fructus. The in vitro experiments indicated that Hippophae fructus extract exhibited inhibitory effects on the proliferation of 3T3-L1 pre-adipocytes. Conclusion: This study reveals that Hippophae fructus exerts antiobesity effects through multiple components, targets, and pathways, providing valuable insights for its clinical research and product development. [ABSTRACT FROM AUTHOR]

There is increasing evidence of a role for environmental contaminants in disrupting metabolic health in both humans and animals. Despite a growing need for well-understood models for evaluating adipogenic and potential obesogenic contaminants, there has been a reliance on decades-old in vitro models that have not been appropriately managed by cell line providers. There has been a quick rise in available in vitro models in the last ten years, including commercial availability of human mesenchymal stem cell and preadipocyte models; these models require more comprehensive validation but demonstrate real promise in improved translation to human metabolic health. There is also progress in developing three-dimensional and co-culture techniques that allow for the interrogation of a more physiologically relevant state. While diverse rodent models exist for evaluating putative obesogenic and/or adipogenic chemicals in a physiologically relevant context, increasing capabilities have been identified for alternative model organisms such as Drosophila, C. elegans, zebrafish, and medaka in metabolic health testing. These models have several appreciable advantages, including most notably their size, rapid development, large brood sizes, and ease of high-resolution lipid accumulation imaging throughout the organisms. They are anticipated to expand the capabilities of metabolic health research, particularly when coupled with emerging obesogen evaluation techniques as described herein.

The dysregulation of energy homeostasis in obesity involves multihormone resistance. Although leptin and insulin resistance have been well characterized, catecholamine resistance remains largely unexplored. Murine β3-adrenergic receptor expression in adipocytes is orders of magnitude higher compared with that of other isoforms. While resistant to classical desensitization pathways, its mRNA (Adrb3) and protein expression are dramatically downregulated after ligand exposure (homologous desensitization). β3-Adrenergic receptor downregulation also occurs after high-fat diet feeding, concurrent with catecholamine resistance and elevated inflammation. This downregulation is recapitulated in vitro by TNF-α treatment (heterologous desensitization). Both homologous and heterologous desensitization of Adrb3 were triggered by induction of the pseudokinase TRIB1 downstream of the EPAC/RAP2A/PI-PLC pathway. TRIB1 in turn degraded the primary transcriptional activator of Adrb3, CEBPα. EPAC/RAP inhibition enhanced catecholamine-stimulated lipolysis and energy expenditure in obese mice. Moreover, adipose tissue expression of genes in this pathway correlated with body weight extremes in a cohort of genetically diverse mice and with BMI in 2 independent cohorts of humans. These data implicate a signaling axis that may explain reduced hormone-stimulated lipolysis in obesity and resistance to therapeutic interventions with β3-adrenergic receptor agonists.

Abstract Background Gremlin-1 (GREM1) and Gremlin-2 (GREM2) are bone morphogenetic protein antagonists that play important roles in organogenesis, tissue differentiation, and tissue homeostasis. Although GREM1 has been reported to be involved in promoting various cancers, little has been reported about effects of GREM2 on cancer. Recently, it has been reported that GREM2 can inhibit adipogenesis in adipose-derived stromal/stem cells. However, as an inhibitor of adipogenesis, the role of GREM2 in cancer progression is not well understood yet. Methods Pre-adipocyte 3T3-L1 cells overexpressing mock or Grem2 were established using a lentiviral transduction system and differentiated into adipocytes-mock and adipocytes-Grem2, respectively. To investigate the effect of adipocyte-Grem2 on breast cancer cells, we analyzed the proliferative and invasion abilities of spheroids using a 3D co-culture system of breast cancer cells and adipocytes or conditioned medium (CM) of adipocytes. An orthotopic breast cancer mouse model was used to examine the role of adipocytes-Grem2 in breast cancer progression. Results Grem2 overexpression suppressed adipogenesis of 3T3-L1 cells. Proliferative and invasion abilities of spheroids formed by co-culturing MTV/TM-011 breast cancer cells and adipocytes-Grem2 were significantly reduced compared to those of spheroids formed by co-culturing MTV/TM-011 cells and adipocytes-mock. Compared to adipocytes-mock, adipocytes-Grem2 showed decreased mRNA expression of several adipokines, notably IL-6. The concentration of IL-6 in the CM of these cells was also decreased. Proliferative and invasive abilities of breast cancer cells reduced by adipocytes-Grem2 were restored by IL-6 treatment. Expression levels of vimentin, slug, and twist1 in breast cancer cells were decreased by treatment with CM of adipocytes-Grem2 but increased by IL-6 treatment. In orthotopic breast cancer mouse model, mice injected with both MTV/TM-011 cells and adipocytes-Grem2 showed smaller primary tumors and lower lung metastasis than controls. However, IL-6 administration increased both the size of primary tumor and the number of metastatic lung lesions, which were reduced by adipocytes-Grem2. Conclusions Our study suggests that GREM2 overexpression in adipocytes can inhibit adipogenesis, reduce the expression and secretion of several adipokines, including IL-6, and ultimately inhibit breast cancer progression.

Squalene (SQ) is a natural compound with anti-inflammatory, anti-cancer, and anti-oxidant effects, but due to its low solubility, its biological properties have been greatly underestimated. This study aims to explore the differences in gene expression patterns of four newly synthesized amphipathic ethylene glycol (EG) derivatives of SQ by whole-genome transcriptomics analysis using DNA microarray to examine the mRNA expression profile of adipocytes differentiated from 3T3-L1 cells treated with SQ and its EG derivatives. Enrichment analyses of the transcriptional data showed that compared with SQ, its EG derivatives exerted different, in most cases desirable, biological responses. EG derivatives showed increased enrichment of mitochondrial functions, lipid and glucose metabolism, and inflammatory response. Mono-, di-, and tetra-SQ showed higher enrichment of the cellular component-ribosome. Histological staining showed EG derivatives prevented excessive lipid accumulation. Additionally, mitochondrial transcription factors showed upregulation in tetra-SQ-treated cells. Notably, EG derivatives showed better anti-inflammatory effects. Further, gene-disease association analysis predicted substantial improvement in the bioactivities of SQ derivatives in metabolic diseases. Cluster analyses revealed di- and tetra-SQ had more functional similarities than others, reflected in their scanning electron microscopy images; both di- and tetra-SQ self-organized into similar sizes and shapes of vesicles, subsequently improving their cation binding activities. Protein-protein interaction networks further revealed that cation binding activity might explain a major part, if not all, of the differences observed in functional analyses. Altogether, the addition of EG derivatives may improve the biological responses of SQ and thus may enhance its health-promoting potential.

Obesity is the excessive accumulation of body fat resulting from impairment in energy balance mechanisms. In this study, we aimed to investigate the mechanism whereby GABA (γ-aminobutyric acid) prevents high-fat diet-induced obesity, and whether it induces lipolysis and browning in white adipose tissue (WAT), using high-fat diet (HFD)-fed obese mice and 3T3-L1 adipocytes. We demonstrated that GABA substantially inhibits the body mass gain of mice by suppressing adipogenesis and lipogenesis. Consistent with this result, histological analysis of WAT demonstrated that GABA decreases adipocyte size. Moreover, we show that GABA administration decreases fasting blood glucose and improves serum lipid profiles and hepatic lipogenesis in HFD-fed obese mice. Furthermore, Western blot and immunofluorescence analyses showed that GABA activates protein kinase A (PKA) signaling pathways that increase lipolysis and promote uncoupling protein 1 (UCP1)-mediated WAT browning. Overall, these results suggest that GABA exerts an anti-obesity effect via the regulation of lipid metabolism. [ABSTRACT FROM AUTHOR]

Fat browning, which converts white adipose tissue to brown, has attracted attention as a promising strategy for the treatment of obesity. Betanin (BT) has been reported to have potential anti-obesity activity. 3T3-L1 cells were differentiated for 7 days during BT treatment. The BT concentration range for the study was determined using an MTT assay, and lipid accumulation was evaluated by Oil-Red-O staining. The expression of protein level was analyzed by Western blot. Immunofluorescence images were performed with confocal microscopy to visually show the amount and location of thermogenesis factor uncoupling protein1 (UCP1) and mitochondria. qRT-PCR was performed to evaluate mRNA expression. BT inhibited lipid accumulation and increased the expression of UCP1, peroxisome-proliferator-activated receptor gamma (PPARγ), and PPARγ coactivator-1 alpha (PGC-1α). In addition, the increases in beige adipocyte-specific markers were observed, supporting BT-mediated browning of the fat tissue. The UCP1 was localized in the inner membrane of the mitochondria, and its expression was associated with mitochondrial activation. Consistent with this, the mRNA expression of mitochondrial biogenesis markers increased in 3T3-L1 cells after BT treatment. Immunofluorescence staining also indicated an increased number of mitochondria and UCP1, respectively. Moreover, BT inhibited lipogenesis and enhanced lipolysis and fatty acid oxidation. This mechanism has been suggested to be mediated by an adenosine monophosphate-activated protein kinase (AMPK) pathway. BT induces fat browning and regulates lipid metabolism via the AMPK-mediated pathway in 3T3-L1 cells, suggesting that BT can be a promising candidate for controlling obesity. [ABSTRACT FROM AUTHOR]

Natural polyphenol-rich plant resources, such as agricultural waste, were proven to diminish insulin resistance and weight gain in rats on a high-fat diet. To test whether date seed polyphenol pills (DSPPs) might lower adipose tissue accumulation by precisely affecting adipocytes, we explored the impacts of DSPPs on cell proliferation, differentiation, and lipolysis in 3T3-L1 cells. We utilized tablets made commercially from date seed polyphenols that were mostly composed of epicatechin (45.9 g/kg). The total polyphenol and antioxidant capacities of the digested and non-digested DSPPs were also evaluated. DSPPs at doses of 25, 50, and 100 µg/mL hindered the proliferation of both pre-confluent preadipocytes and mature post-confluent adipocytes. DSPPs decreased the quantity of viable cells in completely developed adipocytes. Treatment with 100 µg/mL of DSPPs decreased the basal lipolysis of completely differentiated adipocytes but modestly boosted epinephrine-induced lipolysis. A significant transcription factor for the adipogenic gene, the peroxisome proliferator-activated receptor (PPAR), was repressed by DSPPs, which significantly decreased lipid buildup. The total polyphenol and antioxidant capacities were also increased after digestion with a good bubble Pearson correlation between both. DSPPs may have anti-obesity and anti-diabetic characteristics by inhibiting adipocyte development and basal lipolysis, which could be commercially industrialized. [ABSTRACT FROM AUTHOR]

Summary: High amounts of raspberries are wasted every year, which are rich source of bioactive compounds. Thus, raspberry waste was used to obtain the essential oil by maceration and the oleoresin by supercritical fluid extraction (SFE). Higher amounts of total phenolics (185 mg GAE g−1) and flavonoids (11.0 mg QE g−1) were obtained in oleoresins than in essential oil (131 mg GAE g−1 and 9.0 mg QE g−1, respectively). DPPH radical scavenging was 1350 μm TE g−1 for oleoresins and 890 μm TE g−1 for essential oil. SFE allowed the extraction of compounds not reported before in red raspberry such as a pinocembrin and farnesol. Oleoresin at 20 μg mL−1 induced a decrease in lipid accumulation during the 3T3‐L1 cell differentiation process, but no after cells were differentiated. Red raspberry waste is an important source of bioactives that can be extracted using green technologies to generate high commercial value by‐products. [ABSTRACT FROM AUTHOR]

Background and Objectives: This study evaluated the in vitro anti-adipogenic and anti-inflammatory properties of black cumin (Nigella sativa L.) seed extract (BCS extract) as a potential candidate for developing herbal formulations targeting metabolic disorders. Materials and Methods: We evaluated the BCS extract by assessing its 2,2-diphenyl-1-picrohydrazyl (DPPH) radical scavenging activity, levels of prostaglandin E2 (PGE2) and nitric oxide (NO), and mRNA expression levels of key pro-inflammatory mediators. We also quantified the phosphorylation of nuclear factor kappa light chain enhancer of activated B cells (NF-κB) and mitogen-activated protein kinases (MAPK) signaling molecules. To assess anti-adipogenic effects, we used differentiated 3T3-L1 cells and BCS extract in doses from 10 to 100 μg/mL. We also determined mRNA levels of key adipogenic genes, including peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding protein α (C/BEPα), adipocyte protein 2 (aP2), lipoprotein lipase (LPL), fatty acid synthase (FAS), and sterol-regulated element-binding protein 1c (SREBP-1c) using real-time quantitative polymerase chain reaction (qPCR). Results: This study showed a concentration-dependent DPPH radical scavenging activity and no toxicity at concentrations up to 30 μg/mL in Raw264.7 cells. BCS extract showed an IC50 of 328.77 ± 20.52 μg/mL. Notably, pre-treatment with BCS extract (30 μg/mL) significantly enhanced cell viability in lipopolysaccharide (LPS)-treated Raw264.7 cells. BCS extract treatment effectively inhibited LPS-induced production of PGE2 and NO, as well as the expression of monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), inducible NO synthase (iNOS), interleukin (IL)-1β and IL-6, possibly by limiting the phosphorylation of p38, p65, inhibitory κBα (I-κBα), and c-Jun N-terminal kinase (JNK). It also significantly attenuated lipid accumulation and key adipogenic genes in 3T3-L1 cells. Conclusions: This study highlights the in vitro anti-adipogenic and anti-inflammatory potential of BCS extract, underscoring its potential as a promising candidate for managing metabolic disorders. [ABSTRACT FROM AUTHOR]

Phospholipid synthesis and fat storage as triglycerides are regulated by lipin phosphatidic acid phosphatases (PAPs), whose enzymatic PAP function requires association with cellular membranes. Using hydrogen deuterium exchange mass spectrometry, we find mouse lipin 1 binds membranes through an N-terminal amphipathic helix, the Ig-like domain and HAD phosphatase catalytic core, and a middle lipin (M-Lip) domain that is conserved in mammalian and mammalian-like lipins. Crystal structures of the M-Lip domain reveal a previously unrecognized protein fold that dimerizes. The isolated M-Lip domain binds membranes both in vitro and in cells through conserved basic and hydrophobic residues. Deletion of the M-Lip domain in lipin 1 reduces PAP activity, membrane association, and oligomerization, alters subcellular localization, diminishes acceleration of adipocyte differentiation, but does not affect transcriptional co-activation. This establishes the M-Lip domain as a dimeric protein fold that binds membranes and is critical for full functionality of mammalian lipins.

The contribution of adipose-derived FGF21 to energy homeostasis is unclear. Here we show that browning of inguinal white adipose tissue (iWAT) by β-adrenergic agonists requires autocrine FGF21 signaling. Adipose-specific deletion of the FGF21 co-receptor β-Klotho renders mice unresponsive to β-adrenergic stimulation. In contrast, mice with liver-specific ablation of FGF21, which eliminates circulating FGF21, remain sensitive to β-adrenergic browning of iWAT. Concordantly, transgenic overexpression of FGF21 in adipocytes promotes browning in a β-Klotho-dependent manner without increasing circulating FGF21. Mechanistically, we show that β-adrenergic stimulation of thermogenic gene expression requires FGF21 in adipocytes to promote phosphorylation of phospholipase C-γ and mobilization of intracellular calcium. Moreover, we find that the β-adrenergic-dependent increase in circulating FGF21 occurs through an indirect mechanism in which fatty acids released by adipocyte lipolysis subsequently activate hepatic PPARα to increase FGF21 expression. These studies identify FGF21 as a cell-autonomous autocrine regulator of adipose tissue function.

Adipose tissue mass and adiposity change throughout the lifespan. During aging, while visceral adipose tissue (VAT) tends to increase, peripheral subcutaneous adipose tissue (SAT) decreases significantly. Unlike VAT, which is linked to metabolic diseases, including type 2 diabetes, SAT has beneficial effects. However, the molecular details behind the aging-associated loss of SAT remain unclear. Here, by comparing scRNA-seq of total stromal vascular cells of SAT from young and aging mice, we identify an aging-dependent regulatory cell (ARC) population that emerges only in SAT of aged mice and humans. ARCs express adipose progenitor markers but lack adipogenic capacity; they secrete high levels of pro-inflammatory chemokines, including Ccl6, to inhibit proliferation and differentiation of neighboring adipose precursors. We also found Pu.1 to be a driving factor for ARC development. We identify an ARC population and its capacity to inhibit differentiation of neighboring adipose precursors, correlating with aging-associated loss of SAT.

The present study explores the molecular mechanism of anti-obesity effect of total lutein oxidized products (LOPs) in high-fat diet-induced obese C57BL/6 mice. Total LOPs (50, 100, 200 mg/kg b.wt.) were intubated for 22 weeks. Lipid profile, peroxides, AST, ALT, GST activities, lipid metabolizing enzymes/molecules, 3T3-L1 cell differentiation, TGF-β1 and p38 MAPK expressions were studied. Total LOPs at 100 mg/kg b.wt. reduced plasma and hepatic cholesterol, triglycerides, phospholipids, ALT and AST activities. FAS and CPT activities were inhibited in the liver homogenate, and epididymal WAT (eWAT). Total LOPs at 200 mg/kg b.wt. reduced HMGCoA:Mevalonate in eWAT, lipid peroxides in eWAT and liver. GST activity was high in the liver and eWAT. Total LOPs (100μg/ml) suppressed adipogenesis and decreased the accumulation of lipid droplets from two to eight days. Adiponectin was upregulated, PPAR γ, lipoprotein lipase, TGF-β1, and p38 MAPK were down-regulated. The results have shown that total LOPs are potent anti-obese molecules.ABBREVIATIONS: AIN 93G: American institute of nutrition 93 for growth; ALT: alanine transaminase; AST: aspartate transaminase; CEBPα: ccaat/enhancer binding protein α; C-DNA: complementary deoxyribonucleic acid; CPT: carnitine palmitoyl transferase; GST: glutathione-S-transferase; ELISA: enzyme-linked immune sorbent assay; FAS: fatty acid synthase; HDL: high-density lipoprotein; HFD: high-fat diet; HMG CoA: β-Hydroxy β-methylglutaryl-Coenzyme A; LDL: low-density lipoprotein; LOPs: total lutein oxidized products; LPL: lipoprotein lipase; MDA-Malonaldehyde; MTT: 3-(4,5-dimethylthiazol-2-yl)−2,5-diphenyl tetrazolium bromide; MVA: mevalonate; p38MAPK: p38 mitogen-activated protein kinases; RNA: ribonucleic acid; RTq-PCR: quantitative reverse transcription polymerase chain reaction; PPAR-γ: peroxisome proliferator-activated receptor-gamma; TGF-β1: transforming growth factor beta 1; WAT: white adipose tissue.

Infections are a major complication of obesity, but the mechanisms responsible for impaired defense against microbes are not well understood. Here, we found that adipocyte progenitors were lost from the dermis during diet-induced obesity (DIO) in humans and mice. The loss of adipogenic fibroblasts from mice resulted in less antimicrobial peptide production and greatly increased susceptibility to Staphylococcus aureus infection. The decrease in adipocyte progenitors in DIO mice was explained by expression of transforming growth factor-β (TGFβ) by mature adipocytes that then inhibited adipocyte progenitors and the production of cathelicidin in vitro. Administration of a TGFβ receptor inhibitor or a peroxisome proliferator-activated receptor-γ agonist reversed this inhibition in both cultured adipocyte progenitors and in mice and subsequently restored the capacity of obese mice to defend against S. aureus skin infection. Together, these results explain how obesity promotes dysfunction of the antimicrobial function of reactive dermal adipogenesis and identifies potential therapeutic targets to manage skin infection associated with obesity.

Bile acids have recently emerged as key metabolic hormones with beneficial impacts in multiple metabolic diseases. We previously discovered that hepatic bile acid overload distally modulates glucose and fatty acid metabolism in adipose tissues to exert anti-obesity effects. However, the detailed mechanisms that explain the salutary effects of serum bile acid elevation remain unclear. Here, proteomic profiling identified a new hepatokine, Orosomucoid (ORM) that governs liver-adipose tissue crosstalk. Hepatic ORMs were highly induced by both genetic and dietary bile acid overload. To address the direct metabolic effects of ORM, purified ORM proteins were administered during adipogenic differentiation of 3T3-L1 cells and mouse stromal vascular fibroblasts. ORM suppressed adipocyte differentiation and strongly inhibited gene expression of adipogenic transcription factors such as C/EBPβ, KLF5, C/EBPα, and PPARγ. Taken together, our data clearly suggest that bile acid-induced ORM secretion from the liver blocks adipocyte differentiation, potentially linked to anti-obesity effect of bile acids.

Background: Gremlin-1 (GREM1) and Gremlin-2 (GREM2) are bone morphogenetic protein antagonists that play important roles in organogenesis, tissue differentiation, and tissue homeostasis. Although GREM1 has been reported to be involved in promoting various cancers, little has been reported about effects of GREM2 on cancer. Recently, it has been reported that GREM2 can inhibit adipogenesis in adipose-derived stromal/stem cells. However, as an inhibitor of adipogenesis, the role of GREM2 in cancer progression is not well understood yet. Methods: Pre-adipocyte 3T3-L1 cells overexpressing mock or Grem2 were established using a lentiviral transduction system and differentiated into adipocytes-mock and adipocytes-Grem2, respectively. To investigate the effect of adipocyte-Grem2 on breast cancer cells, we analyzed the proliferative and invasion abilities of spheroids using a 3D co-culture system of breast cancer cells and adipocytes or conditioned medium (CM) of adipocytes. An orthotopic breast cancer mouse model was used to examine the role of adipocytes-Grem2 in breast cancer progression. Results: Grem2 overexpression suppressed adipogenesis of 3T3-L1 cells. Proliferative and invasion abilities of spheroids formed by co-culturing MTV/TM-011 breast cancer cells and adipocytes-Grem2 were significantly reduced compared to those of spheroids formed by co-culturing MTV/TM-011 cells and adipocytes-mock. Compared to adipocytes-mock, adipocytes-Grem2 showed decreased mRNA expression of several adipokines, notably IL-6. The concentration of IL-6 in the CM of these cells was also decreased. Proliferative and invasive abilities of breast cancer cells reduced by adipocytes-Grem2 were restored by IL-6 treatment. Expression levels of vimentin, slug, and twist1 in breast cancer cells were decreased by treatment with CM of adipocytes-Grem2 but increased by IL-6 treatment. In orthotopic breast cancer mouse model, mice injected with both MTV/TM-011 cells and adipocytes-Grem2 showed smaller primary tumors and lower lung metastasis than controls. However, IL-6 administration increased both the size of primary tumor and the number of metastatic lung lesions, which were reduced by adipocytes-Grem2. Conclusions: Our study suggests that GREM2 overexpression in adipocytes can inhibit adipogenesis, reduce the expression and secretion of several adipokines, including IL-6, and ultimately inhibit breast cancer progression. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect and mechanism of mannan-binding lectin （MBL） on inflammation and insulin resistance of 3T3-L1 adipocytes induced by lipopolysaccharide. Methods: 3T3-L1 preadipocytes were induced to mature adipocyte, and the degree of cell differentiation was analyzed by oil red O staining. The effects of MBL（ 1, 10, 20 μg/ml） and LPS on cell proliferation ability were detected by CCK-8 during differentiation. Contents of IL-6 and TNF-α were detected by ELISA. The expressions of IL-6, TNF-α and TLR4/NF-κBproteins in signaling pathway, GLUT4 and the phosphorylation of Akt and IRS-1 try were analyzed by Western blot. Flow cytometry was used to detect the regulation of MBL on glucose uptake in 3T3-L1 cells. Results: Oil red O staining confirmed that 3T3-L1 preadipocytes had been induced into mature adipocytes at 12 days. CCK-8 results showed that different concentrations of MBL （1, 10, 20 μg/ml） and LPS had no significant effect on cell proliferation during the whole process of differentiation. The results of ELISA and Western blot showed that MBL inhibited LPS-induced inflammatory factor secretion in a concentration dependent manner during the differentiation and maturation of adipocytes. Western blot results showed that MBL inhibited LPS-induced IκB phosphorylation, IKK phosphorylation, TLR4 and nuclear NF-κB expressions in a concentration-dependent manner, MBL enhanced Akt and IRS-1 phosphorylation and increased GLUT4 expression; flow cytometry showed that MBL could remove LPS inhibition of glucose uptake in 3T3-L1 cells in a dose-dependent manner. Conclusion: In adipocytes, MBL can inhibit the secretion of pro-inflammatory factors in 3T3-L1 cells through TLR4/NF-κB signaling pathway, achieving anti-inflammatory effect. MBL relieves the inhibition of glucose uptake and IRS-1/Akt signaling by LPS in 3T3-L1 cells through the inhibition of inflammatory factor secretion, achieving alleviation of insulin resistance. [ABSTRACT FROM AUTHOR]

The present study was aimed to evaluate the anti-adipogenic activity of piperine (PIP) and epigallocatechin gallate (EGCG) in 3T3-L1 cells. In cytotoxicity studies, PIP and EGCG showed IC50 values of 260 and 218 µM respectively and in combination (20 µM each) did not show cytotoxicity. Treatment with PIP and EGCG (20 µM each) significantly (p<.01) inhibited cell differentiation, lipid droplets deposition and enhanced glycerol release in 3T3-L1 cells. The secreted level of leptin was decreased but adiponectin level was increased in treated 3T3-L1 cells than untreated cells. In molecular expression studies, key adipogenic genes PPAR-γ, SREBP-1c, FAS, Fab-4, C/EBP-α and HMG-CoA reductase were markedly down-regulated but UCP-1 was up-regulated in treated 3T3-L1 cells and the same trend was observed in expression levels of selected proteins. In conclusion, our results demonstrated a combination of PIP and EGCG exhibited strong anti-adipogenic and lipid lowering effect than individual treatments due to synergism. [ABSTRACT FROM AUTHOR]

The signaling pathway of fatty acids in the context of obesity is an extensively explored topic, yet their primary mechanism of action remains incompletely understood. This study aims to examine the effect of docosahexaenoic acid (DHA) on some crucial aspects of adipogenesis in differentiating 3T3-L1 cells, using palmitic acid-treated (PA), standard differentiated, and undifferentiated adipocytes as controls. Employing 60 µM DHA or PA, 3T3-L1 preadipocytes were treated from the onset of adipogenesis, with negative and positive controls included. After eight days, we performed microscopic observations, cell viability assays, the determination of adiponectin concentration, intracellular lipid accumulation, and gene expression analysis. Our findings demonstrated that DHA inhibits adipogenesis, lipolysis, and glucose uptake by suppressing peroxisome proliferator-activated receptor gamma (Pparg) and G-protein coupled receptor 120 (Gpr120) gene expression. Cell cytotoxicity was ruled out as a causative factor, and β-oxidation involvement was suspected. These results challenge the conventional belief that omega-3 fatty acids, acting as Pparg and Gpr120 agonists, promote adipogenesis and enhance insulin-dependent glucose cell flux. Moreover, we propose a novel hypothesis suggesting the key role of the co-repressor G protein pathway suppressor 2 in mediating this process. Additional investigations are required to elucidate the molecular mechanisms driving DHA's anti-adipogenic effect and its broader health implications. [ABSTRACT FROM AUTHOR]

Obesity is a major risk factor for a variety of diseases and contributes to chronic inflammation. Resveratrol is a naturally occurring antioxidant that can reduce adipogenesis. In this study, the antiadipogenic and anti-inflammatory activities of resveratrol-enriched rice were investigated in 3T3-L1 adipocyte cells. Cotreatment of dexamethasone and isobutylmethylxanthin upregulated adipogenic transcription factors and signaling pathways. Subsequent treatment of adipocytes with rice seed extracts suppressed the differentiation of 3T3-L1 by downregulating adipogenic transcription factors (peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α) and signaling pathways (extracellular signal-regulated kinase 1/2 and protein kinase B Akt), this was especially observed in cells treated with germinated resveratrol-enriched rice seed extract (DJ526_5). DJ526_5 treatment also markedly reduced lipid accumulation in the cells and expression of adipogenic genes. Lipopolysaccharide (LPS)-induced inflammatory cytokines (prostaglandin-endoperoxide synthase 2 (COX-2), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) decreased in cells treated with DJ526_5. Collectively, DJ526_5 exerts antiadipogenic effects by suppressing the expression of adipogenesis transcription factors. Moreover, DJ526_5 ameliorates anti-inflammatory effects in 3T3-L1 adipocytes by inhibiting the activation of phosphorylation NF-κB p65 and ERK ½ (MAPK). These results highlight the potential of resveratrol-enriched rice as an alternative obesity-reducing and anti-inflammatory agent. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated the existence of a discrete pool of cholesterol in the plasma membranes (PM) of mammalian cells-referred to as the accessible cholesterol pool-that can be detected by the binding of modified versions of bacterial cytolysins (e.g., anthrolysin O). When the amount of accessible cholesterol in the PM exceeds a threshold level, the excess cholesterol moves to the endoplasmic reticulum (ER), where it regulates the SREBP2 pathway and undergoes esterification. We reported previously that the Aster/Gramd1 family of sterol transporters mediates nonvesicular movement of cholesterol from the PM to the ER in multiple mammalian cell types. Here, we investigated the PM pool of accessible cholesterol in cholesterol-loaded fibroblasts with a knockdown of Aster-A and in mouse macrophages from Aster-B and Aster-A/B-deficient mice. Nanoscale secondary ion mass spectrometry (NanoSIMS) analyses revealed expansion of the accessible cholesterol pool in cells lacking Aster expression. The increased accessible cholesterol pool in the PM was accompanied by reduced cholesterol movement to the ER, evidenced by increased expression of SREBP2-regulated genes. Cosedimentation experiments with liposomes revealed that the Aster-B GRAM domain binds to membranes in a cholesterol concentration-dependent manner and that the binding is facilitated by the presence of phosphatidylserine. These studies revealed that the Aster-mediated nonvesicular cholesterol transport pathway controls levels of accessible cholesterol in the PM, as well as the activity of the SREBP pathway.

G protein-coupled receptor 120 (GPR120) and PPARγ agonists each have insulin sensitizing effects. But whether these two pathways functionally interact and can be leveraged together to markedly improve insulin resistance has not been explored. Here, we show that treatment with the PPARγ agonist rosiglitazone (Rosi) plus the GPR120 agonist Compound A leads to additive effects to improve glucose tolerance and insulin sensitivity, but at lower doses of Rosi, thus avoiding its known side effects. Mechanistically, we show that GPR120 is a PPARγ target gene in adipocytes, while GPR120 augments PPARγ activity by inducing the endogenous ligand 15d-PGJ2 and by blocking ERK-mediated inhibition of PPARγ. Further, we used macrophage- (MKO) or adipocyte-specific GPR120 KO (AKO) mice to show that GRP120 has anti-inflammatory effects via macrophages while working with PPARγ in adipocytes to increase insulin sensitivity. These results raise the prospect of a safer way to increase insulin sensitization in the clinic.

Small GTPases are essential signaling molecules for regulating glucose uptake in adipose tissues upon insulin stimulation, and this regulation maintains an appropriate range of glycemia. The involvement of small GTPases in adipogenesis, however, has not been systemically investigated. In this study, we applied a high-throughput scheduled multiple-reaction monitoring (MRM) method, along with the use of synthetic stable isotope-labeled peptides, to identify differentially expressed small GTPase proteins during adipogenesis of cultured murine cells. We were able to quantify the relative levels of expression of 55 and 49 small GTPases accompanied by adipogenic differentiation in 3T3-L1 and C3H10T1/2 cells, respectively. When compared with analysis conducted in the data-dependent acquisition (DDA) mode, the MRM-based proteomic platform substantially increased the coverage of the small GTPase proteome. Western blot analysis further corroborated the MRM quantification results for selected small GTPases. Interestingly, overall a significant number of small GTPases were down-regulated during adipogenesis. Among them, the expression levels of Rab32 protein were consistently lower in differentiated adipocytes than the corresponding undifferentiated precursors in both cell lines. Overexpression of Rab32 in 3T3-L1 and C3H10T1/2 cells prior to adipogenesis induction suppressed their differentiation. Together, this is the first comprehensive analysis of the alterations in small GTPase proteome during adipogenesis, and we reveal a previously unrecognized role of Rab32 in adipogenic differentiation.

Our understanding of adipose tissue biology has steadily evolved. While structural and energy storage functionalities have been in the forefront, a key endocrine role for adipocytes was revealed only over the last few decades. In contrast to the wealth of information on dynamic function of other endocrine tissues, few studies have focused on dynamic adipose tissue function or on tool development toward that end. Here, we apply our unique droplet-based microfluidic devices to culture, perfuse, and sample secretions from primary murine epididymal white adipose tissue (eWAT), and from predifferentiated clusters of 3T3-L1 adipocytes. Through automated control, oil-segmented aqueous droplets (∼2.6 nL) were sampled from tissue or cells at 3.5 second temporal resolution (including sample and reference droplets), with integrated enzyme assays enabling real-time quantification of glycerol (down to 1.9 fmol per droplet). This high resolution revealed previously unreported oscillations in secreted glycerol at frequencies of 0.2 to 2.0 min-1 (∼30-300 s periods) present in the primary tissue but not in clustered cells. Low-level bursts (∼50 fmol) released in basal conditions were contrasted with larger bursts (∼300 fmol) during stimulation. Further, both fold changes and burst magnitudes were decreased in eWAT of aged and obese mice. These results, combined with immunostaining and photobleaching analyses, suggest that gap-junctional coupling or nerve cell innervation within the intact ex vivo tissue explants play important roles in this apparent tissue-level, lipolytic synchronization. High-resolution, quantitative sampling by droplet microfluidics thus permitted unique biological information to be observed, giving an analytical framework poised for future studies of dynamic oscillatory function of adipose and other tissues.

Obesity is caused by the accumulation of excess lipids due to an energy imbalance. Differentiation of pre-adipocytes induces abnormal lipid accumulation, and reactive oxygen species (ROS) generated in this process promote the differentiation of pre-adipocytes through mitogen-activated protein kinase (MAPK) signaling. Peroxiredoxin (Prx) is a potent antioxidant enzyme, and peroxiredoxin 5 (Prx5), which is mainly expressed in cytosol and mitochondria, inhibits adipogenesis by regulating ROS levels. Based on previous findings, the present study was performed to investigate whether cytosolic Prx5 (CytPrx5) or mitochondrial Prx5 (MtPrx5) has a greater effect on the inhibition of adipogenesis. In this study, MtPrx5 decreased insulin-mediated ROS levels to reduce adipogenic gene expression and lipid accumulation more effectively than CytPrx5. In addition, we found that p38 MAPK mainly participates in adipogenesis. Furthermore, we verified that MtPrx5 overexpression suppressed the phosphorylation of p38 during adipogenesis. Thus, we suggest that MtPrx5 inhibits insulin-induced adipogenesis more effectively than CytPrx5. [ABSTRACT FROM AUTHOR]

Gadolinium-based contrast agents (GBCAs) are widely used in magnetic resonance imaging (MRI) to improve the sensitivity and enhance diagnostic performance. GBCAs are mostly eliminated from the body through the kidney after administration; however small amounts of gadolinium are retained in the brain and other tissues. Although there is increasing concern about the adverse health effects of gadolinium, the cellular effects of GBCAs remains poorly understood. Here, we elucidated the potential cytotoxicity of the GBCAs Omniscan and Gadovist in 12 different cell lines, especially 3T3-L1 adipocyte cell line. Omniscan and Gadovist treatments significantly increased intracellular gadolinium levels in 3T3-L1 cells in a time- and dose-dependent manner. Additionally, Omniscan and Gadovist treatments downregulated the expression of adipocyte differentiation markers, including peroxisome proliferator-activated receptor γ (PPARG), adiponectin (ADIPOQ), and fatty acid-binding protein (FABP4), in 3T3-L1 cells, especially during early differentiation (day 0–2). Moreover, histological analysis using Oil red O staining showed that gadolinium chloride (GdCl 3) treatment suppressed lipid droplet accumulation and the expression of adipocyte differentiation markers. Overall, the results showed that Omniscan and Gadovist treatment suppressed adipocyte differentiation in 3T3-L1 cells, contributing to the understanding of the potential toxic effects of GBCA exposure. • Omniscan and Gadovist promotes intracellular gadolinium content in 3T3-L1 cells. • Omniscan and Gadovist decrease adipokine expression during differentiation. • Gadolinium chloride suppresses lipid droplet accumulation in 3T3-L1 cells. [ABSTRACT FROM AUTHOR]

Adult mesenchymal stem cells, including preadipocytes, possess a cellular sensory organelle called the primary cilium. Ciliated preadipocytes abundantly populate perivascular compartments in fat and are activated by a high-fat diet. Here, we sought to understand whether preadipocytes use their cilia to sense and respond to external cues to remodel white adipose tissue. Abolishing preadipocyte cilia in mice severely impairs white adipose tissue expansion. We discover that TULP3-dependent ciliary localization of the omega-3 fatty acid receptor FFAR4/GPR120 promotes adipogenesis. FFAR4 agonists and ω-3 fatty acids, but not saturated fatty acids, trigger mitosis and adipogenesis by rapidly activating cAMP production inside cilia. Ciliary cAMP activates EPAC signaling, CTCF-dependent chromatin remodeling, and transcriptional activation of PPARγ and CEBPα to initiate adipogenesis. We propose that dietary ω-3 fatty acids selectively drive expansion of adipocyte numbers to produce new fat cells and store saturated fatty acids, enabling homeostasis of healthy fat tissue.

Insulin resistance is a key feature of obesity and type 2 diabetes. PU.1 is a master transcription factor predominantly expressed in macrophages but after HFD feeding PU.1 expression is also significantly increased in adipocytes. We generated adipocyte specific PU.1 knockout mice using adiponectin cre to investigate the role of PU.1 in adipocyte biology, insulin and glucose homeostasis. In HFD-fed obese mice systemic glucose tolerance and insulin sensitivity were improved in PU.1 AKO mice and clamp studies indicated improvements in both adipose and liver insulin sensitivity. At the level of adipose tissue, macrophage infiltration and inflammation was decreased and glucose uptake was increased in PU.1 AKO mice compared with controls. While PU.1 deletion in adipocytes did not affect the gene expression of PPARg itself, we observed increased expression of PPARg target genes in eWAT from HFD fed PU.1 AKO mice compared with controls. Furthermore, we observed decreased phosphorylation at serine 273 in PU.1 AKO mice compared with fl/fl controls, indicating that PPARg is more active when PU.1 expression is reduced in adipocytes. Therefore, in obesity the increased expression of PU.1 in adipocytes modifies the adipocyte PPARg cistrome resulting in impaired glucose tolerance and insulin sensitivity.