Mitotic Clonal Expansion Research Articles

Ergosterol Peroxide from the Medicinal Mushroom Ganoderma lucidum Inhibits Differentiation and Lipid Accumulation of 3T3-L1 Adipocytes.

Ergosterol peroxide is a natural compound of the steroid family found in many fungi, and it possesses antioxidant, anti-inflammatory, anticancer and antiviral activities. The anti-obesity activity of several edible and medicinal mushrooms has been reported, but the effect of mushroom-derived ergosterol peroxide on obesity has not been studied. Therefore, we analyzed the effect of ergosterol peroxide on the inhibition of triglyceride synthesis at protein and mRNA levels and differentiation of 3T3-L1 adipocytes. Ergosterol peroxide inhibited lipid droplet synthesis of differentiated 3T3-L1 cells, expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAT/enhancer-binding protein alpha (C/EBPα), the major transcription factors of differentiation, and also the expression of sterol regulatory element-binding protein-1c (SREBP-1c), which promotes the activity of PPARγ, resulting in inhibition of differentiation. It further inhibited the expression of fatty acid synthase (FAS), fatty acid translocase (FAT), and acetyl-coenzyme A carboxylase (ACC), which are lipogenic factors. In addition, it inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) involved in cell proliferation and activation of early differentiation transcription factors in the mitotic clonal expansion (MCE) stage. As a result, ergosterol peroxide significantly inhibited the synthesis of triglycerides and differentiation of 3T3-L1 cells, and is, therefore, a possibile prophylactic and therapeutic agent for obesity and related metabolic diseases.

Exposure to HBCD promotes adipogenesis both in vitro and in vivo by interfering with Wnt6 expression

Exposure to HBCD promotes adipogenesis both in vitro and in vivo by interfering with Wnt6 expression

Monosodium glutamate restricts the adipogenic potential of 3T3-L1 preadipocytes through mitotic clonal expansion.

Recent epidemiologic studies pointed out a significant correlation between dietary monosodium glutamate (MSG) and increased body mass index. Corroborating evidences came from animal studies depicting a clear association between dietary MSG intake and increased abdominal fat, dyslipidemia, adipocyte hypertrophy, and total body weight gain. Taken together with the inferred absence of conspicuous hypothalamic neuropathies the hallmark of disease etiopathogenesis in MSG-obese animals, these animal studies with dietary MSG strongly argue for the presence of an alternative non-neuronal route for MSG to mediate its adipose tissue-specific phenotype and body weight gain. On the basis of this hypothesis, we investigated the direct effect of physiologically relevant low (100 µM), moderate (250 µM), and high dosages (2.5 and 25 mM) of MSG on distinct phases of adipocyte differentiation. MSG-dependent changes in cell proliferation and lipid accumulation were analyzed by cell proliferation assays, flow cytometry, and biochemical methods, respectively. Physiologically relevant high dosages MSG demonstrated a significant potential in reducing MCE and thereof adipogenic capacity of preadipocytes in a dose-dependent manner by restricting the availability of critical mitogenic proteins, CCAAT/enhancer-binding protein β (CEBPβ), and the mitotic cyclin B. Our findings warrant further investigations to unravel the effect of long-term dietary MSG intake on capacity of preadipocytes in different fat depots to undergo mitotic clonal expansion and hyperplasia in rodent models and human subjects, respectively.

CD90 serves as differential modulator of subcutaneous and visceral adipose-derived stem cells by regulating AKT activation that influences adipose tissue and metabolic homeostasis

BackgroundWhite adipose tissue includes subcutaneous and visceral adipose tissue (SAT and VAT) with different metabolic features. SAT protects from metabolic disorders, while VAT promotes them. The proliferative and adipogenic potentials of adipose-derived stem cells (ADSCs) are critical for maintaining adipose tissue homeostasis through driving adipocyte hyperplasia and inhibiting pathological hypertrophy. However, it remains to be elucidated the critical molecules that regulate different potentials of subcutaneous and visceral ADSCs (S-ADSCs, V-ADSCs) and mediate distinct metabolic properties of SAT and VAT. CD90 is a glycosylphosphatidylinositol-anchored protein on various cells, which is also expressed on ADSCs. However, its expression patterns and differential regulation on S-ADSCs and V-ADSCs remain unclear.MethodsS-ADSCs and V-ADSCs were detected for CD90 expression. Proliferation, colony formation, cell cycle, mitotic clonal expansion, and adipogenic differentiation were assayed in S-ADSCs, V-ADSCs, or CD90-silenced S-ADSCs. Glucose tolerance test and adipocyte hypertrophy were examined in mice after silencing of CD90 in SAT. CD90 expression and its association with CyclinD1 and Leptin were analyzed in adipose tissue from mice and humans. Regulation of AKT by CD90 was detected using a co-transfection system.ResultsCompared with V-ADSCs, S-ADSCs expressed high level of CD90 and showed increases in proliferation, mitotic clonal expansion, and adipogenic differentiation, together with AKT activation and G1-S phase transition. CD90 silencing inhibited AKT activation and S phase entry, thereby curbing proliferation and mitotic clonal expansion of S-ADSCs. In vivo CD90 silencing in SAT inhibited S-ADSC proliferation, which caused adipocyte hypertrophy and glucose intolerance in mice. Furthermore, CD90 was highly expressed in SAT rather than in VAT in human and mouse, which had positive correlation with CyclinD1 but negative correlation with Leptin. CD90 promoted AKT activation through recruiting its pleckstrin homology domain to plasma membrane.ConclusionsCD90 is differentially expressed on S-ADSCs and V-ADSCs, and plays critical roles in ADSC proliferation, mitotic clonal expansion, and hemostasis of adipose tissue and metabolism. These findings identify CD90 as a crucial modulator of S-ADSCs and V-ADSCs to mediate distinct metabolic features of SAT and VAT, thus proposing CD90 as a valuable biomarker or target for evaluating ADSC potentials, monitoring or treating obesity-associated metabolic disorders.

Ezetimibe ameliorates lipid accumulation during adipogenesis by regulating the AMPK-mTORC1 pathway.

Adipogenesis, a critical process that converts adipocyte precursors into adipocytes, is considered a potential therapeutic target for the treatment of obesity. Ezetimibe, a drug approved by the United States Food and Drug Administration, is used for the treatment of hypercholesterolemia. Recently, it was reported to ameliorate high fat diet-induced dyslipidemia in mice and reduce lipid accumulation in hepatocytes through the activation of AMPK. However, the anti-adipogenic effects of ezetimibe and the underlying molecular mechanism have not yet been elucidated. Here, we found that ezetimibe reduced lipid accumulation via activating AMPK during the early phase of adipogenesis. We also observed that ezetimibe inhibited peroxisome proliferator-activated receptor γ, which is a major transcription factor of adipogenesis. Furthermore, ezetimibe-mediated AMPK activation reduced lipid accumulation by inhibiting mTORC1 signaling, leading to the downregulation of lipogenesis-related genes. Mitotic clonal expansion, required for adipogenesis, accelerates cell cycle progression and cell proliferation. We additionally observed that ezetimibe prevented the progression of mitotic clonal expansion by arresting the cell cycle at the G0/G1 phase, which was followed by the inhibition of cell proliferation. Collectively, ezetimibe-mediated inhibition of adipogenesis is dependent on the AMPK-mTORC1 pathway. Thus, we suggest that ezetimibe might be a promising drug for the treatment of obesity.

Curcumin Attenuates Adipogenesis by Inducing Preadipocyte Apoptosis and Inhibiting Adipocyte Differentiation.

Patients with metabolic syndrome are at an increased risk of developing type 2 diabetes and cardiovascular diseases. The principal risk factor for development of metabolic syndrome is obesity, defined as a state of pathological hyperplasia or/and hypertrophy of adipose tissue. The number of mature adipocytes is determined by adipocyte differentiation from preadipocytes. The purpose of the present study is to investigate the effects of curcumin on adipogenesis and the underlying mechanism. To examine cell toxicity of curcumin, 3T3-L1 preadipocytes were treated with 0–50 µM curcumin for 24, 48, or 72 h, then cell viability was measured using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The effect of curcumin on the cell cycle was determined by flow cytometry. Curcumin-induced cell apoptosis was determined by the TUNEL assay and curcumin-induced caspase activation was measured by immunoblotting. The effect of curcumin on adipocyte differentiation was determined by measuring mitotic clonal expansion (MCE), expression of adipogenic transcription factors, and lipid accumulation. Results showed the viability of preadipocytes was significantly decreased by treatment with 30 µM curcumin, a concentration that caused apoptosis in preadipocytes, as assessed by the TUNEL assay, and caused activation of caspases 8, 9, and 3. A non-cytotoxic dose of curcumin (15 µM) inhibited MCE, downregulated the expression of PPARγ and C/EBPα, prevented differentiation medium-induced β-catenin downregulation, and decreased the lipid accumulation in 3T3-L1 adipocytes. In conclusion, our data show that curcumin can induce preadipocyte apoptosis and inhibit adipocyte differentiation, leading to suppression of adipogenesis.

Pyridocarbazole alkaloids from Ochrosia borbonica: lipid-lowering agents inhibit the cell proliferation and adipogenesis of 3T3-L1 adipocyte via intercalating into supercoiled DNA.

Pyridocarbazole alkaloids from Ochrosia borbonica: lipid-lowering agents inhibit the cell proliferation and adipogenesis of 3T3-L1 adipocyte via intercalating into supercoiled DNA.

ZFP217 regulates adipogenesis by controlling mitotic clonal expansion in a METTL3-m6A dependent manner

ABSTRACT Obesity is becoming a global problem. Research into the detailed mechanism of adipocyte development is crucial for the treatment of excess fat. Zinc finger protein 217 plays roles in adipogenesis. However, the underlying mechanism remains unclear. Here, we demonstrated that ZFP217 knockdown prevented the mitotic clonal expansion process and caused adipogenesis inhibition. Depletion of ZFP217 increased the expression of the m6A methyltransferase METTL3, which upregulated the m6A level of cyclin D1 mRNA. METTL3 knockdown rescued the siZFP217-inhibited MCE and promoted CCND1 expression. YTH domain family 2 recognized and degraded the methylated CCND1 mRNA, leading to the downregulation of CCND1. Consequently, cell-cycle progression was blocked, and adipogenesis was inhibited. YTHDF2 knockdown relieved siZFP217-inhibited adipocyte differentiation. These findings reveal that ZFP217 knockdown–induced adipogenesis inhibition was caused by CCND1, which was mediated by METTL3 and YTHDF2 in an m6A-dependent manner. We have provided novel insight into the underlying molecular mechanisms by which m6A methylation is involved in the ZFP217 regulation of adipogenesis.

PRMT7 deficiency enhances adipogenesis through modulation of C/EBP-β

PRMT7 deficiency enhances adipogenesis through modulation of C/EBP-β

Regulation of in Vitro Adipogenesis by All-trans Retinoic Acid (P21-075-19)

Regulation of in Vitro Adipogenesis by All-trans Retinoic Acid (P21-075-19)

Placental extract suppresses differentiation of 3T3-L1 preadipocytes to mature adipocytes via accelerated activation of p38 MAPK during the early phase of adipogenesis

BackgroundAdipogenesis, the process of preadipocyte differentiation to mature adipocytes accompanied by accumulation of intracytoplasmic lipid droplets, is regulated by various genetic and environmental factors, and closely associated with the development of obesity. Numerous recent studies suggest that some bioactive peptides and proteins derived from animals, and chemical compounds isolated from plants may be useful for prevention and treatment of obesity and obesity-related chronic diseases. In the present study, we examined the broad spectrum of effects of placental extract, with a focus on the influence of placental extract on adipogenesis.MethodWe cultured 3T3-L1 cells, which are widely used as a model of white preadipocytes, under differentiation conditions in the presence of porcine placental extract (PPE) for 8 days, and then stained the lipid droplets accumulated in the cytoplasm with Oil Red O. We also analyzed the effects of PPE on the mitogen-activated protein kinases (MAPKs) signaling, mitotic clonal expansion (MCE) and gene expressions associated with 3T3-L1 differentiation.ResultsWhen we cultured 3T3-L1 cells with PPE under differentiation conditions, the accumulation of lipid droplets and expression of adipocyte differentiation marker genes (Cebpa, Pparg, Slc2a4, Fasn and Adipoq) were dramatically attenuated. The suppressive activity of PPE against adipogenesis was heat-stable and recovered in a low-molecular-weight fraction after ultrafiltration (< 3 kDa) and gel-filtration chromatography (fraction No. 9). We also found that the suppressive activity of PPE affected the early phase of adipocyte differentiation (Days 0–2) without influencing the expression levels of C/EBPβ and C/EBPδ. The PPE and fraction No. 9 obtained from gel-filtration chromatography both promoted mitotic clonal expansion of 3T3-L1 while accelerating p38 MAPK phosphorylation. In addition, SB203580, a p38 MAPK inhibitor, partially restored the accumulation of lipid droplets and the expression of adipocyte differentiation marker genes that were suppressed by fraction No. 9.ConclusionThese results indicate that PPE suppresses the differentiation of preadipocytes via accelerated activation of p38 MAPK during the early phase of adipogenesis, suggesting PPE or its functional component could be a potential therapy for treating obesity.

Spliceostatin A treatment inhibits mitotic clonal expansion and adipogenesis

Spliceostatin A treatment inhibits mitotic clonal expansion and adipogenesis

Flavonoids kaempferide and 4,2′-dihydroxy-4′,5′,6′-trimethoxychalcone inhibit mitotic clonal expansion and induce apoptosis during the early phase of adipogenesis in 3T3-L1 cells

Flavonoids kaempferide and 4,2′-dihydroxy-4′,5′,6′-trimethoxychalcone inhibit mitotic clonal expansion and induce apoptosis during the early phase of adipogenesis in 3T3-L1 cells

Ganoderma Lucidum polysaccharide inhibits lipid accumulation in vivo and in vitro by activating HIF‐1a through ERK1/2 signaling pathway

Ganoderma lucidum polysaccharide (GLP) has been proposed to have beneficial effects against obesity. However, how GLP affects lipid accumulation has not been examined. In this study, we used 3T3‐L1 preadipocytes and a high‐fat diet‐induced obese mice model to investigate the effects and mechanism of GLP on lipid accumulation. Our results revealed that GLP significantly inhibited adipogenic differentiation in a dose‐dependent manner in 3T3‐L1 preadipocytes determined by Oil Red O staining and Triglyceride measurement. In order to explore the mechanism, we conducted a dynamic transcriptome study during 3T3‐L1 preadipocytes differentiation (0 h, 9 h, 18 h, 48 h, 120 h) with or without GLP treatment. Transcriptome analyses showed that GLP significantly caused cellular hypoxia by blocking respiration chain, and inducing the expression of HIF‐1a which is a major regulator of cell cycle arrest during hypoxia by activating the ERK1/2 signaling pathway. And then delayed the mitotic clonal expansion(MCE) which is required for differentiation of 3T3‐L1 cells, eventually inhibiting a cascade of adipogenesis pathway. These has been verified by qRT‐PCR or Western blot. Moreover, flow cytometry data revealed that GLP does arrest cell cycle at G0/G1 phase at 9 h of differentiation. Furthermore, knocking‐down of HIF‐1a by siRNA can abolish the GLP‐induced inhibition of adipogenesis in 3T3‐L1 cells, indicating that HIF‐1a was directly required for GLP‐induced inhibition of aidopogenesis. In addition, we demonstrated that GLP induces the phosphorylation of ERK1/2. Interestingly, pretreatment with ERK inhibitor, significantly rescued GLP‐induced inhibition of adipogenesis. We further demonstrated that HIF‐1a is the downstream target of ERK1/2. Furthermore, GLP treatment significantly suppressed hepatic lipid accumulation by activating ERK1/2/HIF‐1a signaling pathway to improve non‐alcoholic fatty liver disease(NAFLD) and insulin resistance in high‐fat diet‐induced obese mice. Taken together, GLP inhibits lipid accumulation by activating HIF‐1a through ERK1/2 signaling pathway in vivo and in vitro. These findings also indicate that GLP possesses protective effects in NAFLD and IR‐related metabolic disorders.Support or Funding InformationNational Natural Science Foundation of China (Grant No. 81473397).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Natural Products and Obesity: A Focus on the Regulation of Mitotic Clonal Expansion during Adipogenesis.

Obesity is recognized as a worldwide health crisis. Obesity and its associated health complications such as diabetes, dyslipidemia, hypertension, and cardiovascular diseases impose a big social and economic burden. In an effort to identify safe, efficient, and long-term effective methods to treat obesity, various natural products with potential for inhibiting adipogenesis were revealed. This review aimed to discuss the molecular mechanisms underlying adipogenesis and the inhibitory effects of various phytochemicals, including those from natural sources, on the early stage of adipogenesis. We discuss key steps (proliferation and cell cycle) and their regulators (cell-cycle regulator, transcription factors, and intracellular signaling pathways) at the early stage of adipocyte differentiation as the mechanisms responsible for obesity.

The brominated flame retardant PBDE 99 promotes adipogenesis via regulating mitotic clonal expansion and PPARγ expression

The brominated flame retardant PBDE 99 promotes adipogenesis via regulating mitotic clonal expansion and PPARγ expression

FGF11 influences 3T3‐L1 preadipocyte differentiation by modulating the expression of PPARγ regulators

Fibroblast growth factor 11 (FGF11) is a member of the intracellular fibroblast growth factor superfamily. Here, we identified FGF11 as a novel mediator of adipogenesis. During 3T3‐L1 adipocyte differentiation, the expression of FGF11 decreased at the mitotic clonal expansion stage and increased at the terminal differentiation stage. FGF11 knockdown reduced the expression of peroxisome proliferator‐activated receptor gamma (PPARγ), a master regulator of adipogenesis, resulting in the inhibition of adipocyte differentiation. Treatment with the PPARγ agonist rosiglitazone restored the inhibition of adipogenesis caused by FGF11 knockdown. We also report that the expression of the PPARγ regulators CCAAT/enhancer‐binding protein α, sterol regulatory element‐binding protein 1, KLF9, KLF2, GATA binding factor 2, and GATA binding factor 3 was influenced by FGF11. These results suggest that FGF11 indirectly controls the expression of PPARγ through modifying the expression of multiple PPARγ regulators, thereby mediating adipogenesis.

Long non-coding RNA lnc-OAD is required for adipocyte differentiation in 3T3-L1 preadipocytes

Long non-coding RNA lnc-OAD is required for adipocyte differentiation in 3T3-L1 preadipocytes

Syringic acid (4-hydroxy-3,5-dimethoxybenzoic acid) inhibits adipogenesis and promotes lipolysis in 3T3-L1 adipocytes

Increase in adiposity is associated with obesity and obesity-related complications. Syringic acid (SA), a phenolic acid facilitates oxidation, polymerization, and condensation reactions, may function as an effective anti-adipogenic agent. This study examined whether SA inhibits adipogenesis in 3T3-L1 preadipocytes by inhibiting differentiation and controlling lipid accumulation. Ten days of SA treatment suppressed differentiation of 3T3-L1 preadipocyte to mature adipocytes in a concentration-dependent manner as determined by Oil Red O staining. Suppression of adipogenic differentiation by SA was primarily from inhibition of mitotic clonal expansion during the early stages of differentiation. Treatment of adipocytes with SA reduced triglyceride production (lipogenesis) and increased glycerol release (lipolysis). The addition of SA to the adipocytes attenuated in vitro ROS production. These results indicate that SA inhibits the adipogenesis of 3T3-L1 preadipocytes, reduces lipid accumulation, and attenuates ROS accumulation, suggesting for the first time that SA has an anti-obesity effect in vitro.

Linifanib exerts dual anti-obesity effect by regulating adipocyte browning and formation

Linifanib exerts dual anti-obesity effect by regulating adipocyte browning and formation