scholarly journals Heterogeneity in the physiological states and pharmacological responses of differentiating 3T3-L1 preadipocytes

2009 ◽  
Vol 187 (3) ◽  
pp. 375-384 ◽  
Author(s):  
Lit-Hsin Loo ◽  
Hai-Jui Lin ◽  
Dinesh K. Singh ◽  
Kathleen M. Lyons ◽  
Steven J. Altschuler ◽  
...  
Keyword(s):  
Immunofluorescence Microscopy ◽  
Hormone Sensitive Lipase ◽  
Molecular Heterogeneity ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Specific Effects ◽  
Enhancer Binding Protein ◽  
Perilipin A ◽  
Pparγ Agonists ◽  
Hormone Sensitive

Increases in key components of adipogenesis and lipolysis pathways correlate at the population-averaged level during adipogenesis. However, differentiating preadipocytes are highly heterogeneous in cellular and lipid droplet (LD) morphologies, and the degree to which individual cells follow population-averaged trends is unclear. In this study, we analyze the molecular heterogeneity of differentiating 3T3-L1 preadipocytes using immunofluorescence microscopy. Unexpectedly, we only observe a small percentage of cells with high simultaneous expression of markers for adipogenesis (peroxisome proliferator-activated receptor γ [PPARγ], CCAAT/enhancer-binding protein α, and adiponectin) and lipid accumulation (hormone-sensitive lipase, perilipin A, and LDs). Instead, we identify subpopulations of cells with negatively correlated expressions of these readouts. Acute perturbation of adipocyte differentiation with PPARγ agonists, forskolin, and fatty acids induced subpopulation-specific effects, including redistribution of the percentage of cells in observed subpopulations and differential expression levels of PPARγ. Collectively, our results suggested that heterogeneity observed during 3T3-L1 adipogenesis reflects a dynamic mixture of subpopulations with distinct physiological states.

scholarly journals Alisol A 24-acetate stimulates lipolysis in 3 T3-L1 adipocytes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hai-xia Lou ◽  
Wen-cheng Fu ◽  
Jia-xiang Chen ◽  
Tian-tian Li ◽  
Ying-ying Jiang ◽  
...  
Keyword(s):  
Biological Activities ◽  
Quantitative Polymerase Chain Reaction ◽  
Underlying Mechanism ◽  
Hormone Sensitive Lipase ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Protein Levels ◽  
Alisma Orientale ◽  
Perilipin A ◽  
Hormone Sensitive

Abstract Background Alisol A 24-acetate (AA-24-a), one of the main active triterpenes isolated from the well-known medicinal plant Alisma orientale (Sam.) Juz., exhibits multiple biological activities including hypolipidemic activity. However, its effect on lipid metabolism in adipocytes remains unclear. The present study aimed to clarify the effect of AA-24-a on adipocyte lipolysis and to determine its potential mechanism of action using 3 T3-L1 cells. Methods We assayed the release of glycerol into culture medium of 3 T3-L1 cells under treatment with AA-24-a. Protein and mRNA expression and phosphorylation levels of the main lipases and kinases involved in lipolysis regulation were determined by quantitative polymerase chain reaction and western blotting. Specific inhibitors of protein kinase A (PKA; H89) and extracellular signal-regulated kinase (ERK; PD98059), which are key enzymes in relevant signaling pathways, were used to examine their roles in AA-24-a-stimulated lipolysis. Results AA-24-a significantly stimulated neutral lipolysis in fully differentiated adipocytes. To determine the underlying mechanism, we assessed the changes in mRNA and protein levels of key lipolysis-related genes in the presence or absence of H89 and PD98059. Both inhibitors reduced AA-24-a-induced lipolysis. Moreover, pretreatment with H89 attenuated AA-24-a-induced phosphorylation of hormone-sensitive lipase at Ser660, while pretreatment with PD98059 attenuated AA-24-a-induced downregulation of peroxisome proliferator-activated receptor-γ and perilipin A. Conclusions Our results indicate that AA-24-a promoted neutral lipolysis in 3 T3-L1 adipocytes by activating PKA-mediated phosphorylation of hormone-sensitive lipase and ERK- mediated downregulation of expression of perilipin A.

scholarly journals Peroxisome Proliferator-Activated Receptor-γ Transcriptionally Up-Regulates Hormone-Sensitive Lipase via the Involvement of Specificity Protein-1

Endocrinology ◽  
2006 ◽  
Vol 147 (2) ◽  
pp. 875-884 ◽  
Author(s):  
Tuo Deng ◽  
Song Shan ◽  
Ping-Ping Li ◽  
Zhu-Fang Shen ◽  
Xian-Ping Lu ◽  
...  
Keyword(s):  
Specific Inhibitor ◽  
Binding Activity ◽  
Hormone Sensitive Lipase ◽  
Proximal Promoter ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Specificity Protein 1 ◽  
Pparγ Agonists ◽  
Hormone Sensitive ◽  
Specificity Protein

Both peroxisome proliferator-activated receptor (PPAR)-γ and hormone-sensitive lipase (HSL) play important roles in lipid metabolism and insulin sensitivity. We demonstrate that expression of the HSL gene is up-regulated by PPARγ and PPARγ agonists (rosiglitazone and pioglitazone) in the cultured hepatic cells and differentiating preadipocytes. Rosiglitazone treatment also results in up-regulation of the HSL gene in liver and skeleton muscle from an experimental obese rat model, accompanied by the decreased triglyceride content in these tissues. The proximal promoter (−87 bp of the human HSL gene) was found to be essential for PPARγ-mediated transactivating activity. This important promoter region contains two GC-boxes and binds the transcription factor specificity protein-1 (Sp1) but not PPARγ. The Sp1-promoter binding activity can be endogenously enhanced by PPARγ and rosiglitazone, as demonstrated by analysis of EMSA and chromatin immunoprecipitation assay. Mutations in the GC-box sequences reduce the promoter binding activity of Sp1 and the transactivating activity of PPARγ. In addition, mithramycin A, the specific inhibitor for Sp1-DNA binding activity, abolishes the PPARγ-mediated up-regulation of HSL. These results indicate that PPARγ positively regulates the HSL gene expression, and up-regulation of HSL by PPARγ requires the involvement of Sp1. Taken together, this study suggests that HSL may be a newly identified PPARγ target gene, and up-regulation of HSL may be an important mechanism involved in action of PPARγ agonists in type 2 diabetes.

scholarly journals The Demethoxy Derivatives of Curcumin Exhibit Greater Differentiation Suppression in 3T3-L1 Adipocytes Than Curcumin: A Mechanistic Study of Adipogenesis and Molecular Docking

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1025
Author(s):  
Ahmed Alalaiwe ◽  
Jia-You Fang ◽  
Hsien-Ju Lee ◽  
Chun-Hui Chiu ◽  
Ching-Yun Hsu
Keyword(s):  
Molecular Docking ◽  
Fatty Acid Synthase ◽  
Structural Similarity ◽  
Mechanistic Study ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Enhancer Binding Protein ◽  
Underlying Mechanisms ◽  
Amp Activated Protein Kinase

Curcumin is a known anti-adipogenic agent for alleviating obesity and related disorders. Comprehensive comparisons of the anti-adipogenic activity of curcumin with other curcuminoids is minimal. This study compared adipogenesis inhibition with curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC), and their underlying mechanisms. We differentiated 3T3-L1 cells in the presence of curcuminoids, to determine lipid accumulation and triglyceride (TG) production. The expression of adipogenic transcription factors and lipogenic proteins was analyzed by Western blot. A significant reduction in Oil red O (ORO) staining was observed in the cells treated with curcuminoids at 20 μM. Inhibition was increased in the order of curcumin < DMC < BDMC. A similar trend was observed in the detection of intracellular TG. Curcuminoids suppressed differentiation by downregulating the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), leading to the downregulation of the lipogenic enzymes acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS). AMP-activated protein kinase α (AMPKα) phosphorylation was also activated by BDMC. Curcuminoids reduced the release of proinflammatory cytokines and leptin in 3T3-L1 cells in a dose-dependent manner, with BDMC showing the greatest potency. BDMC at 20 μM significantly decreased leptin by 72% compared with differentiated controls. Molecular docking computation indicated that curcuminoids, despite having structural similarity, had different interaction positions to PPARγ, C/EBPα, and ACC. The docking profiles suggested a possible interaction of curcuminoids with C/EBPα and ACC, to directly inhibit their expression.

scholarly journals Flubendiamide Enhances Adipogenesis and Inhibits AMPKα in 3T3-L1 Adipocytes

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2950 ◽  
Author(s):  
Quancai Sun ◽  
Jie Lin ◽  
Yukui Peng ◽  
Ruichang Gao ◽  
Ye Peng
Keyword(s):  
Adipocyte Differentiation ◽  
Peroxisome Proliferator ◽  
Potential Influence ◽  
Peroxisome Proliferator Activated Receptor ◽  
Acetyl Coenzyme A ◽  
Enhancer Binding Protein ◽  
Triglyceride Content ◽  
Important Regulator ◽  
Amp Activated Protein Kinase ◽  
Acetyl Coenzyme A Carboxylase

Flubendiamide, a ryanoid class insecticide, is widely used in agriculture. Several insecticides have been reported to promote adipogenesis. However, the potential influence of flubendiamide on adipogenesis is largely unknown. The current study was therefore to determine the effects of flubendiamide on adipogenesis utilizing the 3T3-L1 adipocytes model. Flubendiamide treatment not only enhanced triglyceride content in 3T3-L1 adipocytes, but also increased the expression of cytosine-cytosine-adenosine-adenosine-thymidine (CCAAT)/enhancer-binding protein α and peroxisome proliferator-activated receptor gamma-γ, two important regulators of adipocyte differentiation. Moreover, the expression of the most important regulator of lipogenesis, acetyl coenzyme A carboxylase, was also increased after flubendiamide treatment. Further study revealed that 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or A769662, two Adenosine 5′-monophosphate (AMP)-activated protein kinase α activators, subverted effects of flubendiamide on enhanced adipogenesis. Together, these results suggest that flubendiamide promotes adipogenesis via an AMPKα-mediated pathway.

scholarly journals Crocetin Isolated from the Natural Food Colorant Saffron Reduces Intracellular Fat in 3T3-L1 Adipocytes

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1648
Author(s):  
Elena Jiménez-Ortega ◽  
Aitana Braza-Boïls ◽  
Miguel Burgos ◽  
Natalia Moratalla-López ◽  
Manuel Vicente ◽  
...  
Keyword(s):  
Lipid Accumulation ◽  
Low Cost ◽  
Natural Food ◽  
Peroxisome Proliferator ◽  
Synthetic Dyes ◽  
Potential Candidate ◽  
Peroxisome Proliferator Activated Receptor ◽  
Food Colorant ◽  
Enhancer Binding Protein ◽  
Diphenyltetrazolium Bromide

Saffron, as a food colorant, has been displaced by low-cost synthetic dyes. These have unhealthy properties; thus, their replacement with natural food colorants is an emerging trend. Obesity is a worldwide health problem due to its associated comorbidities. Crocetin esters (crocins) are responsible for the red saffron color. Crocetin (CCT) exhibits healthful properties. We aimed to broaden the existing knowledge on the health properties of CCT isolated from saffron, to facilitate its consideration as a healthy natural food colorant in the future. We evaluated the ability of CCT (1 and 5 μM) to reduce lipid accumulation during the differentiation of 3T3-L1 preadipocytes. Intracellular fat was quantified by Oil Red O staining. CTT cytotoxicity was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The number and size of lipid droplets were analyzed using WimLipid software. The expression of adipogenic genes (CCAAT/enhancer-binding protein (C/EBPβ, C/EBPδ, C/EBPα), and peroxisome proliferator-activated receptor γ (PPARγ)) was analyzed using quantitative real-time PCR (qRT-PCR). CCT 5 μM decreased intracellular fat by 22.6%, without affecting viability or lipid droplet generation, via a decrease in C/EBPα expression, implicated in lipid accumulation. Thus, CCT is a potential candidate to be included in dietary therapies aimed at reversing adipose tissue accumulation in obesity.

Expression of lipogenic genes is upregulated in the heart with exercise training-induced but not pressure overload-induced left ventricular hypertrophy

2013 ◽  
Vol 304 (12) ◽  
pp. E1348-E1358 ◽  
Author(s):  
Pawel Dobrzyn ◽  
Aleksandra Pyrkowska ◽  
Monika K. Duda ◽  
Tomasz Bednarski ◽  
Michal Maczewski ◽  
...  
Keyword(s):  
Regulatory Element ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Hormone Sensitive Lipase ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Cardiac Lipid ◽  
Protein Levels ◽  
Lipogenic Genes ◽  
Pathological Hypertrophy

Cardiac hypertrophy is accompanied by molecular remodeling that affects different cellular pathways, including fatty acid (FA) utilization. In the present study, we show that cardiac lipid metabolism is differentially regulated in response to physiological (endurance training) and pathological [abdominal aortic banding (AAB)] hypertrophic stimuli. Physiological hypertrophy was accompanied by an increased expression of lipogenic genes and the activation of sterol regulatory element-binding protein-1c and Akt signaling. Additionally, FA oxidation pathways regulated by AMP-activated protein kinase (AMPK) and peroxisome proliferator activated receptor-α (PPARα) were induced in trained hearts. Cardiac lipid content was not changed by physiological stimulation, underlining balanced lipid utilization in the trained heart. Moreover, pathological hypertrophy induced the AMPK-regulated oxidative pathway, whereas PPARα and expression of its downstream targets, i.e., acyl-CoA oxidase and carnitine palmitoyltransferase I, were not affected by AAB. In contrast, pathological hypertrophy leads to cardiac triglyceride (TG) and diacylglycerol (DAG) accumulation, although the expression of lipogenic genes and the levels of FA transport proteins (CD36 and FATP) were not changed or reduced compared with the sham group. A possible explanation for this phenomenon is a decrease in lipolysis, as evidenced by the increased content of adipose triglyceride lipase inhibitor G0S2, the increased phosphorylation of hormone-sensitive lipase at Ser565, and the decreased protein levels of DAG lipase that attenuate TG and DAG contents. The increased TG and DAG accumulation observed in AAB-induced hypertrophy might have lipotoxic effects, thereby predisposing to cardiomyopathy and heart failure in the future.

scholarly journals Central leptin regulates heart lipid content by selectively increasing PPAR β/δ expression

2018 ◽  
Vol 236 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Cristina Mora ◽  
Cristina Pintado ◽  
Blanca Rubio ◽  
Lorena Mazuecos ◽  
Virginia López ◽  
...  
Keyword(s):  
Target Genes ◽  
Cardiac Tissue ◽  
Cardiac Metabolism ◽  
Pyruvate Dehydrogenase Kinase ◽  
Hormone Sensitive Lipase ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Expression Of Genes ◽  
Gene And Protein Expression ◽  
Tag Accumulation

The role of central leptin in regulating the heart from lipid accumulation in lean leptin-sensitive animals has not been fully elucidated. Herein, we investigated the effects of central leptin infusion on the expression of genes involved in cardiac metabolism and its role in the control of myocardial triacylglyceride (TAG) accumulation in adult Wistar rats. Intracerebroventricular (icv) leptin infusion (0.2 µg/day) for 7 days markedly decreased TAG levels in cardiac tissue. Remarkably, the cardiac anti-steatotic effects of central leptin were associated with the selective upregulation of gene and protein expression of peroxisome proliferator-activated receptor β/δ (PPARβ/δ, encoded by Pparb/d) and their target genes, adipose triglyceride lipase (encoded by Pnpla2, herefater referred to as Atgl), hormone sensitive lipase (encoded by Lipe, herefater referred to as Hsl), pyruvate dehydrogenase kinase 4 (Pdk4) and acyl CoA oxidase 1 (Acox1), involved in myocardial intracellular lipolysis and mitochondrial/peroxisomal fatty acid utilization. Besides, central leptin decreased the expression of stearoyl-CoA deaturase 1 (Scd1) and diacylglycerol acyltransferase 1 (Dgat1) involved in TAG synthesis and increased the CPT-1 independent palmitate oxidation, as an index of peroxisomal β-oxidation. Finally, the pharmacological inhibition of PPARβ/δ decreased the effects on gene expression and cardiac TAG content induced by leptin. These results indicate that leptin, acting at central level, regulates selectively the cardiac expression of PPARβ/δ, contributing in this way to regulate the cardiac TAG accumulation in rats, independently of its effects on body weight.

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