Mouse 3T3-L1 Cells Research Articles

1,25‑Dihydroxyvitamin D3 mitigates the adipogenesis induced by bisphenol A in 3T3-L1 and hAMSC through miR-27-3p regulation

PurposeEndocrine-disrupting compounds, including bisphenol A (BPA), may promote obesity influencing basal metabolic rate and shifting metabolism towards energy storage. The role of 1,25‑Dihydroxyvitamin D3 (VitD) in counteracting adipogenesis is still a matter of debate. Thus, the current study aims to investigate whether and how VitD exposure during adipogenesis could prevent the pro-adipogenic effect of BPA in two adipocyte models, mouse 3T3-L1 cell line and human adipose-derived mesenchymal stem cells (hAMSC).Methods3T3-L1, mouse pre-adipocytes and human adipose-derived mesenchymal stem cells (hAMSC) were treated with VitD (10−7 M) and BPA (10−8 M and 10−9 M), alone or in combination, throughout the differentiation in mature adipocytes. Cellular lipid droplet accumulation was assessed by Oil Red O staining, mRNA and protein expression of key adipogenic markers, transcription factors, and cytokines were investigated by RT-qPCR and WB, respectively. miRNAs involved in the regulation of adipogenic transcription factors were evaluated by RT-qPCR, and highly potent steric-blocking oligonucleotides (miRNA inhibitors) were used to modulate miRNAs expression.ResultsPre-adipocytes express VitD receptor (VDR) in basal condition, but during the differentiation process VDR expression reduces if not stimulated by the ligand. VitD significantly decreases lipid accumulation, with a consequent reduction in adipogenic marker expression, and counteracts the pro-adipogenic effect of BPA in 3T3-L1 and hAMSC during differentiation. This effect is associated to the increased expression of miR-27a-3p and miR-27b-3p. The blocking of miR-27a-3p and miR-27b-3p through miRNA inhibitors prevents the anti-adipogenic effect of VitD in both cell models.ConclusionsThese results suggest that in cultured 3T3-L1 and hAMSC VitD induces an anti-adipogenic effect and prevents BPA pro-adipogenic effect by triggering at least in part epigenetic mechanisms involving miR-27-3p.

PABPN1 functions as a downstream gene of CREB to inhibit the proliferation of preadipocytes.

This study was designed to reveal the role of nuclear poly(A) binding protein 1 (PABPN1) in the proliferation of preadipocytes, and to reveal the relationship between PABPN1 and cAMP response element (CRE)-binding protein (CREB) in the regulation of preadipocyte proliferation. Vectors overexpressing and siRNAs against PABPN1/CREB were transiently transfected into both porcine preadipocytes and mouse 3T3-L1 cells. Preadipocyte proliferation was measured with CCK-8, EdU, real-time quantitative PCR, Western blotting, and flow cytometry analyses. Additionally, the transcriptional regulation of CREB on PABPN1 were analyzed with dual-luciferase reporter gene and EMSA assays. Overexpression of PABPN1 inhibits, and knockdown of PABPN1 promotes, the proliferation of both porcine preadipocytes and 3T3-L1 cell lines. PABPN1 overexpression increased, while knockdown decreased, the cell population in the G0/G1 phase. These indicates that PABPN1 repressed preadipocyte proliferation by inhibiting cell cycle progress. Additionally, it was revealed that CREB regulated the expression of PABPN1 through binding to the promoter and that CREB inhibited preadipocyte proliferation by repressed cell cycle progress. Furthermore, we showed that PABPN1 functions as a downstream gene of CREB to regulate the proliferation of preadipocytes. PABPN1 inhibits preadipocyte proliferation by suppressing the cell cycle. We also found that CREB could promote PABPN1 expression by binding to a motif in the promoter. Further analysis confirmed that PABPN1 functions as a downstream gene of CREB to regulate the proliferation of preadipocytes. These results suggest that the CREB/PABPN1 axis plays a role in the regulation of preadipocyte proliferation, which will contribute to further revealing the mechanism of fat accumulation.

1,25-Dihydroxyvitamin D3 reduces adipogenesis and mitigates the bisphenol-A-induced pro-adipogenic effect in mouse 3T3-L1 cell line and human adipose-derived mesenchymal stem cells through miR-27-3p regulation

1,25-Dihydroxyvitamin D3 reduces adipogenesis and mitigates the bisphenol-A-induced pro-adipogenic effect in mouse 3T3-L1 cell line and human adipose-derived mesenchymal stem cells through miR-27-3p regulation

Effects of mifepristone on adipocyte differentiation in mouse 3T3-L1 cells

BackgroundBoth glucocorticoid receptor and peroxisome proliferator-activated receptor-γ (PPARγ) play a critical role in adipocyte differentiation. Mifepristone is not only an antagonist of the glucocorticoid receptor but also an agonist of PPARγ. Therefore, the present study investigated the effect of mifepristone on adipocyte differentiation.MethodsMouse 3T3-L1 cells were used as a model for adipocyte differentiation. The lipid droplet formation was evaluated with Bodipy493/503 staining and the expression of adipocyte markers [adiponectin and adipocyte fatty acid binding protein-4 (Fabp4)] was evaluated with quantitative PCR and immunoblot analyses for indication of adipocyte differentiation. siRNA and neutralizing antibodies were used to elucidate the molecular mechanism of mifepristone-induced adipocyte differentiation. Luciferase reporter assay was used to examine the effect of mifepristone on the promoter activity of PPAR-response element (PPRE). The DNA microarray analysis was used to characterize the transcriptome of the mifepristone-induced adipocytes. In vivo adipogenic effect of mifepristone was examined in mice.ResultsMifepristone not only enhanced adipocyte differentiation induced by the conventional protocol consisting of insulin, dexamethasone and 3-isobutyl-1-methylxanthine but also induced adipocyte differentiation alone, as evidenced by lipid droplets formation and induction of the expression of adiponectin and Fabp4. These effects were inhibited by an adiponectin-neutralizing antibody and a PPARγ antagonist. Mifepristone activated the promoter activity of PPRE in a manner sensitive to PPARγ antagonist. A principal component analysis (PCA) of DNA microarray data revealed that the mifepristone-induced adipocytes represent some characteristics of the in situ adipocytes in normal adipose tissues to a greater extent than those induced by the conventional protocol. Mifepristone administration induced an increase in the weight of epididymal, perirenal and gluteofemoral adipose tissues.ConclusionsMifepristone alone is capable of inducing adipocyte differentiation in 3T3-L1 cells and adipogenesis in vivo. PPARγ plays a critical role in the mifepristone-induced adipocyte differentiation. Mifepristone-induced adipocytes are closer to the in situ adipocytes than those induced by the conventional protocol. The present study proposes a single treatment with mifepristone as a novel protocol to induce more physiologically relevant adipocytes in 3T3-L1 cells than the conventional protocol.

Anti-Obesity Effects of Hovenia Dulcis Branches in Mouse Adipocytes, 3t3-l1 Cells, and High-Fat Diet Obese Mice.

Hovenia dulcis has been reported to have various pharmacological activities, but most studies were done with its fruits. However, from an economic point of view, the use of discarded leaves and branches as by-products is very valuable. In this study, thein vitro andin vivo anti-obesity activities of Hovenia dulcis branch extract (HDB) were investigated to evaluate the applicability of HDB as an anti-obesity agent. In differentiated 3T3-L1 cells, HDB inhibited lipid droplet accumulation. And HDB downregulated CEBPα, PPARγ, and perilipin-1, and upregulated ATGL, p-HSL, HSL, p-AMPK, UCP-1, PGC-1α, PRDM16, LC3-II, and p62/SQSTM1. In addition, HDB increased free glycerol content. In HFD-induced obese mice, HDB reduced body weight and total fat weight. In addition, HDB decreased blood LDL-cholesterol, blood total cholesterol, and blood triglyceride. These results indicate that HDB has anti-obesity activity and HDB can be used as a healthy functional food agent for weight reduction.

Long-term hypoxia exposure impairs metabolic pathways of de novo lipogenesis in young mouse adipocytes

Introduction: Obstructive sleep apnea syndrome, manifested by tissue hypoxia, is causally linked with the development of metabolic diseases such as Type 2 diabetes. Although there is convincing epidemiological evidence, molecular mechanisms mediating the adverse metabolic effects remain unclear. Hypoxia may play an important role and modulate metabolic pathways in young adipocytes including the utilization of glucose and acetate or the activation of the reverse tricarboxylic acid cycle (rTCA) leading to increase de novo lipogenesis and excessive fat accumulation. The aim of this study was to investigate the impact of long-term hypoxia on important pathways of de novo lipogenesis in mouse early and late adipocytes. Hypothesis: Hypoxia affects the utilization of carbon sources for de novo lipogenesis differently in early and late adipocytes. Methods: Mouse 3T3-L1 cells were differentiated into adipocytes for 7 days - early adipocytes (EA) or 14 days - late adipocytes (LA). The cells were cultured in gas-permeable cultureware allowing exposure to sustained oxygen levels of 21% O 2 or 4% O 2 . [ 13 C-5]-glutamine (2.5mM) was added to culture media for 7 and 14 days to assess 13 C incorporation to newly synthesized lipids via rTCA and [ 13 C-1]-glutamine (2.5mM) was added to media for 24h to assess 13 C incorporation to rTCA metabolites. The 13 C incorporation studies were analyzed via gas chromatography-mass spectrometry. The contribution of glucose and acetate to de novo lipogenesis was assessed using [ 14 C]-glucose and [ 14 C]-acetate (both 0.2 μCi) provided in culture media for 2h at the end of experiments. Subsequently, radioactivity in extracted lipids was measured via scintillation counter. Statistical significance was assessed by 2-way ANOVA followed by Tukey's test. Data are presented as means ± SD, N=9. Data Hypoxia had no effect on lipid accumulation in EA, lipid accumulation in LA was increased by 134,41% vs control. The 13 C incorporation to lipids was increased in EA by 42,2% vs control and by 13,33% vs LA. The 13 C incorporation in citrate was increased by 8,71%, in malate by 9,58% in EA vs control, in LA the incorporation remained unchanged. The [ 14 C]-glucose incorporation to lipids was elevated in EA vs control by 209,98% and EA vs LA by 60,02%. The [ 14 C]-acetate incorporation to lipids was increased in EA by 198,43% vs control and decreased by 45,13% vs LA. Differences are statistically significant (p <0.05). Summary: The effect of hypoxia on lipid accumulation was observed at the late stages of adipocyte maturation. However, in EA hypoxia initially stimulated the activation of rTCA to partially contribute to de novo lipogenesis and significantly increased 14 C-glucose incorporation. In LA the rTCA and 14 C-glucose incorporation were reduced to the control level and the contribution of acetate was increased. Conclusion: Hypoxia modified metabolic pathways in maturating adipocytes leading to increased de novo lipogenesis and thus hypertrophic mature adipocytes. Project was supported by Grant Agency of the Charles University project GAUK 294822 and by grant AZV project NU21-01-00259 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Luteolin protects against adipogenic and lipogenic potency induced by human relevant mixtures of persistent organic pollutants (POPs) in the 3T3-L1 model.

Human exposure to persistent organic pollutants (POPs) may contribute to obesogenic effects. We have previously shown that POP mixtures modelled on blood levels relevant to the Scandinavian population induces adipogenic effects in the mouse 3T3-L1 cell line. Luteolin is a flavone that has shown anti-lipogenic and anti-adipogenic effects on adipogenesis in in vitro models. In this study, luteolin has been applied to inhibit adipocyte formation and intracellular lipid content increase induced by a human relevant mixture of POPs. 3T3-L1 cells were exposed to a POP mixture consisting of 29 chemicals, including amongst others polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), perfluoroalkylated acids (PFAAs), and polybrominated diphenyl ethers (PBDEs). Rosiglitazone was applied as a positive lipogenic control. Luteolin was tested between 0.5 and 10μM. High content analysis was used to assess changes in adipocyte formation and intracellular lipid content in the 3T3-L1 cell line. Luteolin significantly reduced POP-induced adipocyte formation at 2, 5 and 10μM, and lipid accumulation at 10μM. Interestingly, luteolin did not affect rosiglitazone induced adipo- and lipogenic effects, suggesting differences in mechanisms of action. In conclusion, this in vitro study shows that dietary polyphenols such as luteolin may protect against POP induced adipo- and lipogenic effects.

Effects of solid-state fermentation using R. oligosporus on the phytochemical composition of wild-simulated ginseng leaf and its biological properties

Wild-simulated ginseng (WSG) grown in the mountains without specific facilities is widely used as functional foods in Asian countries due to its bioactive compounds, such as ginsenosides. However, long-time cultivation, lower survival rate, and small size of WSG limit its use in the food industry. In this study, WSG leaves, which can be harvested annually, were fermented using R. oligosporus for 0–10 days. The phytochemical compounds of fermented WSG leaves, including squalene, phenols, saponins, and most ginsenosides (except for Rb1), were increased. L-carnitine was newly synthesized in WSG leaves, with a content of 165.1 μg/g measured after 10 days of fermentation. Moreover, the minor ginsenosides Rg2, Rg3, Rh1, F1, F2, and CK increased by 1.32-, 1.58-, 1.42-, 1.91-, 1.49-, and 4.43-fold compared to non-fermented WSG leaves. The highest antioxidant activities, as measured by FRAP and ORAC assays of WSG leaves, were obtained after 3 days of fermentation. Furthermore, the suppression of NO release in LPS-stimulated RAW264.7 cells and lipid accumulation in mouse 3T3-L1 cells of fermented WSG leaves was greater than in WSG leaves. From these results, fermented WSG leaves have potential applications as functional materials in the food industry.

Reorganization of the DNA replication landscape during adipogenesis is closely linked with adipogenic gene expression.

The temporal order of DNA replication along the chromosomes is thought to reflect the transcriptional competence of the genome. During differentiation of mouse 3T3-L1 cells into adipocytes, cells undergo one or two rounds of cell division called mitotic clonal expansion (MCE). MCE is an essential step for adipogenesis; however, little is known about the regulation of DNA replication during this period. Here, we performed genome-wide mapping of replication timing (RT) in mouse 3T3-L1 cells before and during MCE, and identified a number of chromosomal regions shifting toward either earlier or later replication through two rounds of replication. These RT changes were confirmed in individual cells by single-cell DNA-replication sequencing. Coordinate changes between a shift toward earlier replication and transcriptional activation of adipogenesis-associated genes were observed. RT changes occurred before the full expression of these genes, indicating that RT reorganization might contribute to the mature adipocyte phenotype. To support this, cells undergoing two rounds of DNA replication during MCE had a higher potential to differentiate into lipid droplet-accumulating adipocytes, compared with cells undergoing a single round of DNA replication and non-replicating cells.

Discovery of a novel anti-obesity meroterpenoid agent targeted subcutaneous adipose tissue

BackgroundMeroterpenoid furanasperterpene A (T2–3) with a novel 6/6/6/6/5 pentacyclic skeleton was isolated from the Aspergillus terreus GZU-31–1. Previously, we showed that T2–3 possessed significant lipid-lowering effects in 3T3-L1 adipocytes at 5 μM concentration. However, its therapeutic effect in metabolic disease and the underlying mechanisms of action remain unclear. MethodsHigh fat diet-induced obesity (DIO) mouse model and 3T3-L1 cell model were used to assess the anti-obesity effects of T2–3. Lipids in the adipocytes were examined by Oil Red O staining. β-catenin expression was examined by immunofluorescence and Western blotting, its activity was assessed by TOPflash/FOPflash assay. ResultsT2–3 possessed potent anti-obesity effects in DIO mice, it significantly reduced body weight and subcutaneous adipose tissue (SAT) mass. Mechanistic studies showed that T2–3 significantly inhibited 3T3-L1 preadipocyte differentiation as indicated by the reduced number of mature adipocytes. The treatments also reduced the expressions of critical adipogenic transcription factors CEBP-α and PPAR-γ in both 3T3-L1 adipocytes and SAT in DIO mice. Interestingly, T2–3 increased the cytoplasmic and nuclear expressions of β-catenin and the transcriptional activity of β-catenin in 3T3-L1 adipocytes; the elevated β-catenin expression was also observed in SAT of the T2–3-treated DIO mice. Indeed, upregulation of β-catenin activity suppressed adipogenesis, while β-catenin inhibitor JW67 reversed the anti-adipogenic effect of T2–3. Taken together, our data suggest that T2–3 inhibits adipogenesis by upregulating β-catenin activity. ConclusionsOur study is the first report demonstrating meroterpenoid furanasperterpene A as a novel 6/6/6/6/5 pentacyclic skeleton (T2–3) that possesses potent anti-adipogenic effect by targeting β-catenin signaling pathway. Our findings drive new anti-obesity drug discovery and provide drug leads for chemists and pharmacologists.

Genetic association-based functional analysis detects HOGA1 as a potential gene involved in fat accumulation.

Although there are a number of discoveries from genome-wide association studies (GWAS) for obesity, it has not been successful in linking GWAS results to biology. We sought to discover causal genes for obesity by conducting functional studies on genes detected from genetic association analysis. Gene-based association analysis of 917 individual exome sequences showed that HOGA1 attains exome-wide significance (p-value < 2.7 × 10–6) for body mass index (BMI). The mRNA expression of HOGA1 is significantly increased in human adipose tissues from obese individuals in the Genotype-Tissue Expression (GTEx) dataset, which supports the genetic association of HOGA1 with BMI. Functional analyses employing cell- and animal model-based approaches were performed to gain insights into the functional relevance of Hoga1 in obesity. Adipogenesis was retarded when Hoga1 was knocked down by siRNA treatment in a mouse 3T3-L1 cell line and a similar inhibitory effect was confirmed in mice with down-regulated Hoga1. Hoga1 antisense oligonucleotide (ASO) treatment reduced body weight, blood lipid level, blood glucose, and adipocyte size in high-fat diet-induced mice. In addition, several lipogenic genes including Srebf1, Scd1, Lp1, and Acaca were down-regulated, while lipolytic genes Cpt1l, Ppara, and Ucp1 were up-regulated. Taken together, HOGA1 is a potential causal gene for obesity as it plays a role in excess body fat development.

Biochemical characterization of synthesized fisetin glucoside by dextransucrase from Leuconostoc mesenteroides NRRL B-1299CB4 with enhanced water solubility

Fisetin (7,3',4'-flavon-3-ol) is a flavonol found in plants, fruits, and vegetables. It exhibits diverse biological activities, including antioxidant, anti-inflammatory, and anti-cancer effects. However, the low water solubility and bioavailability of fisetin restrict its pharmaceutical applications. In this work, we synthesized a novel fisetin-4'-O-α-D-glucopyranoside (FST-G1) using transglucosylation with sucrose, fisetin, and dextransucrase from Leuconostoc mesenteroides NRRL B-1299CB4. The water solubility of FST-G1 (109.8 ± 6.3 mg/L) was enhanced compared to fisetin (13.6 ± 1.3 mg/L). The antioxidant activities of FST-G1 in non-cellular assays, including ORAC, ABTS•+, and FRAP assays, were lower compared to fisetin. However, FST-G1 exhibited higher nitric oxide inhibition (62.5 µM; 92.3 %) in lipopolysaccharide-stimulated RAW 264.7 murine macrophage cells compared to fisetin (81.4 %). Anti-lipid accumulation in mouse 3T3-L1 cells treated with FST-G1 was similar to that in cells treated with fisetin. Taken together, the novel synthesized FST-G1 is expected to become a promising functional material for using in the pharmaceutical industry.

FATP1 Exerts Variable Effects on Adipogenic Differentiation and Proliferation in Cells Derived From Muscle and Adipose Tissue.

In livestock, intramuscular adipose tissue is highly valued whereas adipose tissue in other depots is considered as waste. Thus, genetic factors that favor fat deposition in intramuscular compartments over that in other adipose depots are highly desirable in meat-producing animals. Fatty acid transport 1 (FATP1) has been demonstrated to promote cellular fatty acid uptake and metabolism; however, whether it also influences cellular lipid accumulation remains unclear. In the present study, we investigated the effects of FATP1 on the differentiation and proliferation of adipocytes in five types of cells derived from muscle and adipose tissue and estimated the effects of FATP1 on intramuscular fat (IMF) deposition. We showed that FATP1 is mainly expressed in heart and muscle tissue in buffaloes as well as cells undergoing adipogenic differentiation. Importantly, we found that FATP1 promoted the adipogenic differentiation of muscle-derived cells (buffalo myocytes and intramuscular preadipocytes and mouse C2C12 cells) but did not affect, or even inhibited, that of adipose-derived cells (buffalo subcutaneous preadipocytes and mouse 3T3-L1 cells, respectively). Correspondingly, our results further indicated that FATP1 promotes IMF deposition in mice in vivo. Meanwhile, FATP1 was found to enhance the proliferative activity of all the assessed cells, except murine 3T3-L1 cells. These results provide new insights into the potential effects of FATP1 on IMF deposition, especially regarding its positive effects on meat quality in buffaloes and other livestock.

2D structured graphene nanosheets decorated by monodispersed superparamagnetic Fe3O4 nanoparticles for differentiation of mouse cells

In the present study, the reduced graphene oxide (RGO) decorated by monodispersed superparamagnetic Fe3O4 (RGO-IO) nanocomposite was prepared and confirmed with various spectroscopic and microscopic techniques. The elemental spectral mapping depicts the composition of carbon, oxygen and iron in confirmed the successful formulation and homogenous distribution. The X-ray photoelectron spectroscopy (XPS) analysis of nanocomposite confirms the existence of elements such as C, O and Fe. The Raman spectroscopy analysis showed the characteristic peak for RGO i.e. D-band and G-band and A1 g phonon and Eg phonon peaks for IO is indicating the formation of RGO-IO. Moreover, the HR-TEM microscopic analysis evidently revealed the 2D structured RGO nanosheets are well decorated by a large quantity of IO nanoparticles. The in vitro cytotoxic activity of nanocomposite showed less toxicity and increased the cellular growth of mouse C2C12 and 3T3-L1 cells at higher concentration. The treatment of nanocomposite increases the ROS generation due to the excellent electrochemical performance and induces the formation of myotubes and mature adipocytes. The nanocomposite upregulates the expression of molecular marker proteins responsible for the myogenesis and adipogenesis was confirmed. Together, the synthesized RGO-IO nanocomposites provide surplus support for the use of nanomaterials in tissue engineering and regenerative medicine.

Cellular Uptake of Pyrroloquinoline Quinone in Its Intact and Derivatized Forms from the Cell Culture Medium of 3T3-L1

Following a growing interest in the physiological effects of pyrroloquinoline quinone (PQQ), more cell culture experiments have begun to elucidate its mechanism of action. However, to our knowledge, no reports have used instrumental analysis, such as liquid chromatography-tandem mass spectrometry (LC-MS/MS), to study cellular uptake of PQQ. In addition, despite the propensity of PQQ to react with amino acids and other compounds, only a handful of cell culture experiments have been conducted on PQQ derivatives. In the present study, we prepared PQQ derivatives by reacting PQQ with various amino acids and used them as reference standards for optimizing the LC-MS/MS analysis conditions to detect PQQ and its derivatives. Using this method, we evaluated the uptake of PQQ into mouse 3T3-L1 cells and found that most PQQ added to the medium was taken up by the cells in its unchanged form, while some PQQ reacted with amino acids in the medium and was taken up by the cells as PQQ derivatives. These results suggest that PQQ derivatives may contribute to the physiological effects of PQQ. To further elucidate the function of PQQ, it is necessary for future studies to clarify the activity of PQQ derivatives and to evaluate the types of PQQ present in food, animal, and cell samples in more detail.

Amber Extract Reduces Lipid Content in Mature 3T3-L1 Adipocytes by Activating the Lipolysis Pathway.

Amber—the fossilized resin of trees—is rich in terpenoids and rosin acids. The physiological effects, such as antipyretic, sedative, and anti-inflammatory, were used in traditional medicine. This study aims to clarify the physiological effects of amber extract on lipid metabolism in mouse 3T3-L1 cells. Mature adipocytes are used to evaluate the effect of amber extract on lipolysis by measuring the triglyceride content, glucose uptake, glycerol release, and lipolysis-related gene expression. Our results show that the amount of triacylglycerol, which is stored in lipid droplets in mature adipocytes, decreases following 96 h of treatment with different concentrations of amber extract. Amber extract treatment also decreases glucose uptake and increases the release of glycerol from the cells. Moreover, amber extract increases the expression of lipolysis-related genes encoding perilipin and hormone-sensitive lipase (HSL) and promotes the activity of HSL (by increasing HSL phosphorylation). Amber extract treatment also regulates the expression of other adipocytokines in mature adipocytes, such as adiponectin and leptin. Overall, our results indicate that amber extract increases the expression of lipolysis-related genes to induce lipolysis in 3T3-L1 cells, highlighting its potential for treating various obesity-related diseases.

Profiling of RNA-binding Proteins Interacting With Glucagon and Adipokinetic Hormone mRNAs.

ObjectiveGlucagon in mammals and its homolog (adipokinetic hormone [AKH] in Drosophila melanogaster) are peptide hormones which regulate lipid metabolism by breaking down triglycerides. Although regulatory mechanisms of glucagon and AKH expression have been widely studied, post-transcriptional gene expression of glucagon has not been investigated thoroughly. In this study, we aimed to profile proteins binding with Gcg messenger RNA (mRNA) in mouse and Akh mRNA in Drosophila.MethodsDrosophila Schneider 2 (S2) and mouse 3T3-L1 cell lysates were utilized for affinity pull down of Akh and Gcg mRNA respectively using biotinylated anti-sense DNA oligoes against target mRNAs. Mass spectrometry and computational network analysis revealed mRNA-interacting proteins residing in functional proximity.ResultsWe observed that 1) 91 proteins interact with Akh mRNA from S2 cell lysates, 2) 34 proteins interact with Gcg mRNA from 3T3-L1 cell lysates. 3) Akh mRNA interactome revealed clusters of ribosomes and known RNA-binding proteins (RBPs). 4) Gcg mRNA interactome revealed mRNA-binding proteins including Plekha7, zinc finger protein, carboxylase, lipase, histone proteins and a cytochrome, Cyp2c44. 5) Levels of Gcg mRNA and its interacting proteins are elevated in skeletal muscles isolated from old mice compared to ones from young mice.Conclusion Akh mRNA in S2 cells are under active translation in a complex of RBPs and ribosomes. Gcg mRNA in mouse precursor adipocyte is in a condition distinct from Akh mRNA due to biochemical interactions with a subset of RBPs and histones. We anticipate that our study contributes to investigating regulatory mechanisms of Gcg and Akh mRNA decay, translation, and localization.

Insulin Directly Regulates the Circadian Clock in Adipose Tissue.

Adipose tissue (AT) is a key metabolic organ which functions are rhythmically regulated by an endogenous circadian clock. Feeding is a "zeitgeber" aligning the clock in AT with the external time, but mechanisms of this regulation remain largely unclear. We tested the hypothesis that postprandial changes of the hormone insulin directly entrain circadian clocks in AT and investigated a transcriptional-dependent mechanism of this regulation. We analyzed gene expression in subcutaneous AT (SAT) of obese subjects collected before and after the hyperinsulinemic-euglycemic clamp or control saline infusion (SC). The expressions of core clock genes PER2, PER3, and NR1D1 in SAT were differentially changed upon insulin and saline infusion, suggesting insulin-dependent clock regulation. In human stem cell-derived adipocytes, mouse 3T3-L1 cells, and AT explants from mPer2Luc knockin mice, insulin induced a transient increase of the Per2 mRNA and protein expression, leading to the phase shift of circadian oscillations, with similar effects for Per1 Insulin effects were dependent on the region between -64 and -43 in the Per2 promoter but not on CRE and E-box elements. Our results demonstrate that insulin directly regulates circadian clocks in AT and isolated adipocytes, thus representing a primary mechanism of feeding-induced AT clock entrainment.

A Novel Herbal Combination Decreased Lipid Droplets Accumulation and Cytokines Levels During Adipogenesis by Regulating Leptin, PPARγ and SREBP1c Genes Expression in 3T3L1 Cells

The present study aims at demonstrating the anti-adipogenesis and anti-inflammatory of combination of extracts of commiphora wightti, curcuma longa, and tinospora cordifolia using mouse 3T3-L1 cells. Herbal formula (CCT) significantly suppressed the mRNA of PPARγ, leptin, and SREBP1c expression, which is reveals its significant anti-adipogenesis activity. In addition, CCT down-regulated TNFα and iNOS expression, this is an added advantage and helps to alleviate the inflammatory reactions during adipogenesis. These findings encourage for further studies using in vivo models of obesity and associated complications.

Zero valent zinc regulates adipocyte differentiation through calpain family protein and peroxisome proliferator-activated receptor gamma signaling in mouse 3T3-L1 cells

In the present study, the zero valent zinc (ZVZ) was used in the field of tissue regeneration engineering by inducing the preadipocytes into mature adipocytes in mouse 3T3-L1 cells. Initially, the ZVZ nanoparticles was synthesized using chemical reduction method and confirmed by EDS spectrum analysis which showed the presence of zinc ion without any impurities. The XRD and Raman analysis showed the characteristic peaks of zinc with hexagonal structure and the strong phonon band attributed to ZVZ, respectively. The microscopic analysis showed the ZVZ nanoparticles are well dispersed with spherical shape and the size was found to between 85−95 nm. The in vitro cytotoxic activity of ZVZ against 3T3-L1 showed less toxicity in higher concentration and the results were compared with standard adipogenic stimulant dexamethasone. The oil red O staining assay morphologically confirmed the ZVZ induces adipogenesis in 3T3-L1 as well as increase the lipid accumulation during treatment with ZVZ. Moreover, the ZVZ upregulates the expression of adipogenic marker genes such as PPARγ, FABP4 and the calpain family protein during differentiation of preadipocytes into mature adipocytes. Together, the ZVZ regulates the differentiation in 3T3-L1 cells through PPARγ and calpain signaling pathway deciphers the role of ZVZ in tissue regeneration engineering.