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Objective@#To investigate the role of adenovirus type 36 (Ad36) in the browning of 3T3-L1 cells.@*Methods@#BODIPY staining was performed on the 0, 2nd, 4th, 6th and 8th days of the cocktail induction (control) group and the cocktail plus Ad36 induction (experimental) group to observe the adipogenesis of 3T3-L1 cells.The mRNA and protein expressions of uncoupling protein-1(Ucp1), ATP synthase, H+ transporting, mitochondrial F1 complex, O subunit (Atp5o), cytochrome c oxidase subunit 5B(Cox5b), and perilipin were detected by real-time PCR and Western-blot.@*Results@#The results of BODIPY staining showed that the lipid droplets in the control group gradually became larger with the differentiation of the cells, while the lipid droplets in the experimental group firstly became larger, and then appeared smaller after Ad36 was added on the fourth day. Compared with the control group, the mRNA and protein expression levels of Ucp1, Atp5o, and Cox5b in the experimental group were significantly increased while the expression level of perilipin was significantly decreased (all P<0.05).@*Conclusion@#During the differentiation of 3T3-L1 cells, Ad36 promotes its browning via increasing the expressions of Ucp1, Atp5o, and Cox5b.
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Objective To investigate the role of adenovirus type 36 ( Ad36) in the browning of 3T3-L1 cells. Methods BODIPY staining was performed on the 0, 2nd, 4th, 6th and 8th days of the cocktail induction (control) group and the cocktail plus Ad36 induction ( experimental) group to observe the adipogenesis of 3T3-L1 cells. The mRNA and protein expressions of uncoupling protein-1 ( Ucp1 ), ATP synthase, H+ transporting, mitochondrial F1 complex, O subunit ( Atp5o), cytochrome c oxidase subunit 5B ( Cox5b), and perilipin were detected by real-time PCR and Western-blot. Results The results of BODIPY staining showed that the lipid droplets in the control group gradually became larger with the differentiation of the cells, while the lipid droplets in the experimental group firstly became larger, and then appeared smaller after Ad36 was added on the fourth day. Compared with the control group, the mRNA and protein expression levels of Ucp1, Atp5o, and Cox5b in the experimental group were significantly increased while the expression level of perilipin was significantly decreased ( all P＜0. 05 ). Conclusion During the differentiation of 3T3-L1 cells, Ad36 promotes its browning via increasing the expressions of Ucp1, Atp5o, and Cox5b.
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Aim To identify chemical constituents of supercritical extract from Pteridium aquilinum (Linn.) Kuhn (SFEPA) and investigate its antiadipogenic effect and underlying mechanism. Methods The chemical constituents of SFEPA were identified by GCMS. The differentiation of 3T3L1 preadipocytes was induced to establish cell model. MTT assay was employed to detect cell viability. Oil Red 0 staining was used to analyze the effect of SFEPA on the differentiation of 3T3L1 preadipocytes. qRTPCR was performed to examine the expression of genes related with adipogenesis and lipogenesis. Results Ten compounds of SFEPA were identified. The major constituents were 4, 4, 5, 7, 8pentamethyldihydrocoumarin (36. 0 7 %), ßsitosterol (25. 6 6 %), 4amino7diethylaminochromen2one (8 . 2 6 %) and palmitic acid (5. 0 5 %). SFEPA suppressed 3T3L1 adipocyte differentiation and reduced fat accumulation in a dosedependent manner. Treatment of SFEPA significantly downregulated the mRNA expression of PPARy, C/ EBPa, SREBPlc, as well as FAS and ACC. Conclusions SFEPA can inhibit the adipogenesis and differentiation of 3T3L1 cells, and its mechanism may be closed related to its inhibition of genes expression regulating adipogenesis and lipogenesis. Phenols and alcohols might be potential bioactive components.
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The evidence of the last 20 years shows a link between viral infections and obesity in animals and humans. There are five adenovirus which have been associated with development of obesity in animals. SMAM-1 virus was the first studied in humans associated with obesity. There is compelling evidence that Ad-36 virus could contribute to the development of obesity in humans and it is related with body mass index (BMI). This manuscript reviews the association between Ad-36 and the other four virus infections with obesity. An electronic search of articles in the databases PubMed and Scielo, with use of key words: obesity, infection, adipose tissue, Ad-36, 3T3-L1 was performed. The search was restricted "human" and "animals". The importance of the relationship between virus infections and obesity has increased over the past two decades. Ad-36 shows more compelling evidence in humans. There are reports involving this virus in the enhancement of adipogenesis, adipocyte differentiation, a lower secretion of leptin and an increased insulin sensitivity. Future work should focus in larger cohort studies to confirm this association, which explains the global obesity epidemic from a new perspective.
Subject(s)
Humans , Animals , Adenoviridae/pathogenicity , Adenoviridae Infections/complications , Obesity/virology , Body Mass Index , Adipose Tissue/virology , Risk FactorsABSTRACT
Obesity is associated with a number of metabolic abnormalities such as type 2 diabetes and has become a major health problem worldwide. In the present study, we investigated the effects of Epimedium koreanum Nakai (Herba Epimedii, HE) and its main constituent icariin on the adipocyte differentiation in 3T3-L1 preadipocytes. HE extract and icariin significantly reduced lipid accumulation and suppressed the expressions of PPARγ, C/EBPα, and SREBP-1c in 3T3-L1 adipocytes. They also inhibited fatty acid synthase (FAS), acyl-Co A synthase (ACS1), and perilipin. Moreover, HE extract and icariin markedly increased the phosphorylation of AMPK. These results indicated that HE extract and icariin can inhibit the adipocyte differentiation through downregulation of the adipogenic transcription factors, suggesting that HE containing icariin may be used as a potential therapeutic agent in the treatment and prevention of obesity.
Subject(s)
Animals , Mice , 3T3-L1 Cells , Adipocytes , Cell Biology , Metabolism , Adipogenesis , CCAAT-Enhancer-Binding Protein-alpha , Genetics , Metabolism , Epimedium , Chemistry , Flavonoids , Pharmacology , Lipid Metabolism , PPAR gamma , Genetics , Metabolism , Plant Extracts , Pharmacology , Sterol Regulatory Element Binding Protein 1 , Genetics , MetabolismABSTRACT
Objective To investigate the roles of RU486 inhibiting 3T3-L1 pre-adipocytes differentiation and regulating NF-κB activation. Methods Cells were treated with RU486 with concentrations of 0.1 ~ 10μmol/L for 48 h , then the relative contents of triglyceride were analyzed by Oil-Red O staining assay on 9 th day during adipogenesis. The mRNA expressions of PPARγ2,C/EBPa, LPL and FAS were further measured by Real-time PCR. IκBα protein level was detected by Western bolt and nuclear translocation of NF-κB was observed by immunofluorescence assay. Results The relative contents of triglyceride decreased with the increasing of RU486 concentration. Compared with the control, the relative contents of triglyceride in RU486-treatment groups from 0.5 μmol/L were significantly decreased (P < 0.05 or P < 0.01). Compared with the control, PPARγ2, C/EBPa, LPL and FAS mRNA expression and IκBα protein level were significantly decreased (P < 0.01) and NF-κB nuclear translocated from cytoplasm to nucleus in Group 5 mmol/L RU486. Conclusions RU486 could down regulate IκBα protein level , activate NF-κB nuclear translocation , then down regulate PPARγ2 , C/EBPa , LPL and FAS mRNA expression and inhibit adipocytes differentiation.
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Objective To optimize and establish the methodology for culturing and inducing differentiation of mouse preadipocytes 3T3-L1. Methods The mouse cells 3T3-L1 were incubated in DMEM medium contained with 10%FBS, during which the incubation medium was refreshed every 2 to 3 days. Two methods were used to introduce differentiation, including three-drug combination group and four-drug combination group. The protocol of mediumⅠin three-drug combination group including insulin 10 mg/L, IBMX 0.5 mmol/L and DEX 1.0μmol/L. The protocol of mediumⅠin four-drug combination group including indometacin 0.1 mmol/L based on those of three-drug combination group. Both of them were incubated for 2 days and continuous for 2 times. And medium Ⅱ included insulin 10 mg/L for 2-day culturing and continuous for 2 times. Oil red O staining was used to observe the morphological changes of two groups of cells before and after treatment under inverted microscope. Results Mouse preadipocytes 3T3-L1 appeared in good conditions and grew in a paving stone fashion. These cells covered homogeneously the bottom of incubators, the culture medium refreshed every 2 days. The results of four-drug combination group were better than those of three-drug combination group. After three-drug combination induced differentiation, there was no significant change in cell morphology. Comparing with three-drug combination induced differentiation, four-drug combination was successfully achieved in over 90% of the cell inducing, which were round-shaped, with jacinth ester droplets by oil-red O staining. Conclusion We have optimized the method for culturing and inducing differentiation of mouse preadipocytes 3T3-L1 by adding indometacin on the basis of the three-drug combination induced differentiation.
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The study was designed to measure the effect of S.baicalensiswater extract (SBWE) on 3T3-L1 cells and its adiponectin (ADP) mRNA (Adipoq) and promoter luciferase activity.Cell survival rate was determined by MTT assay.The expression of Adipoq was measured by real-time PCR,while the luciferase report systems of Adipoq were used to transfer 3T3-L1 cells.The luciferase activities of the transferred cells were compared by luciferase assay.It was found that the mRNA expression of Adipoq was decreased in comparison with the control group.The luciferase activity showed a stronger ADP promoter activity in 3T3-L1 cells in SBWE treated group than that of control one.In conclusion,SBWE treatment improves the cykomine expression and luciferase reporter gene activity which will be an essential method for further studies of obesity therapy in traditional Chinese medicine.
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Aim To investigate glucose uptake effects and mechanism of emodin in 3T3-L1 adipocytes. Methods LPS-induced differentiated 3 T3-L1 adipo-cytes were divided into control group and emodin ( 1 , 10, 50 μmol · L-1 ) groups. Then, 6-NBDG uptake and the expression of cell surface GLUT4 , PPARγ, AMPKα1/2 , p-AMPKα1/2 , IRS-1 , p-IRS-1 , Adi-ponectin, chREBP-α and chREBP-β were detected. The ability of 6-NBDG uptake in LPS-induced 3 T3-L1 adipocytes was also evaluated following interference with AMPK inhibitor and PPARγinhibitor, respective-ly. Meanwhile, STZ-induced diabetic rats were ran-domly divided into control group and emodin treatment group. The mRNA expression of Adiponectin and pro-tein expression of cell surface GLUT4 , AMPKα1/2 , p-AMPKα1/2 were measured. Results Compared with the control group, emodin improved the mRNA expres-sion of cell surface GLUT4, Adiponectin, chREBP-αand chREBP-β, and protein expression of cell surface GLUT4 , PPARγ, IRS-1 , p-IRS-1 , AMPKα1/2 and p-AMPKα1/2 in 3T3-L1 adipocytes(P<0. 05). Emodin enhanced 6-NBDG uptake and the uptake of emodin group was both decreased following interference with AMPK inhibitor and PPARγ inhibitor, respectively ( P<0. 05 ) . Emodin also increased the mRNA expression of Adiponectin and protein expression of cell surface GLUT4 , AMPKα1/2 and p-AMPKα1/2 in adipose tis-sue of T2 DM rats ( P <0. 05 ) . Conclusion Emodin can enhance glucose uptake in 3 T3-L1 adipocytes and the mechanism is probably associated with activating Adiponectin and IRS-1 , thereby activating AMPK and PPARγ.
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Obesity occurs when a person's calorie intake exceeds the amount of energy burns, which may lead to pathologic growth of adipocytes and the accumulation of fat in the tissues. In this study, the effect and mechanism of pear pomace extracts on 3T3-L1 adipocyte differentiation and apoptosis of mature adipocytes were investigated. The effects of pear pomace extract on cell viability and the anti-adipogenic and proapoptotic effects were investigated via MTT assay, Oil red O staining, western blot analysis and apoptosis assay. 3T3-L1 preadipocytes were stimulated with DMEM containing 10% FBS, 0.5 mM 3-isobutyl-1-methylxanthine (IBMX), 5 microg/ml insulin and 1 microM dexamethasone for differentiation to adipocytes. 3T3-L1 cells were cultured with PBS or water extract of pear pomace. Water extract of pear pomace effectively inhibited lipid accumulations and expressions of PPAR-gamma and C/EBPalpha in 3T3-L1 cells. It also increased expression of p-AMPK and decreased the expression of SREBP-1c and FAS in 3T3-L1 cells. The induction of apoptosis was observed in 3T3-L1 cells treated with pear pomace. These results indicate that pear pomace water extract inhibits adipogenesis and induces apoptosis of adipocytes and thus can be used as a potential therapeutic substance as part of prevention or treatment strategy for obesity.
Subject(s)
1-Methyl-3-isobutylxanthine , 3T3-L1 Cells , Adipocytes , Adipogenesis , Apoptosis , Blotting, Western , Burns , Cell Survival , Dexamethasone , Insulin , Obesity , Pyrus , Sterol Regulatory Element Binding Protein 1 , WaterABSTRACT
BACKGROUND/OBJECTIVES: The purpose of this study was to examine the effects and associated mechanisms of arctiin, a lignan compound found in burdock, on adipogenesis in 3T3-L1 cells. Also, the effects of arctiin supplementation in obese mice fed a high-fat diet on adiposity were examined. MATERIALS/METHODS: 3T3-L1 cells were treated with arctiin (12.5 to 100 microM) during differentiation for 8 days. The accumulation of lipid droplets was determined by Oil Red O staining and intracellular triglyceride contents. The expressions of genes related to adipogenesis were measured by real-time RT-PCR and Western blot analyses. For in vivo study, C57BL/6J mice were first fed either a control diet (CON) or high-fat diet (HF) to induce obesity, and then fed CON, HF, or HF with 500 mg/kg BW arctiin (HF + AC) for four weeks. RESULTS: Arctiin treatment to 3T3-L1 pre-adipocytes markedly decreased adipogenesis in a dose-dependent manner. The arctiin treatment significantly decreased the protein levels of the key adipogenic regulators PPARgamma and C/EBPalpha, and also significantly inhibited the expression of SREBP-1c, fatty acid synthase, fatty acid-binding protein and lipoprotein lipase. Also, arctiin greatly increased the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target phosphorylated-acetyl CoA carboxylase. Furthermore, administration of arctiin significantly decreased the body weight in obese mice fed with the high-fat diet. The epididymal, perirenal or total visceral adipose tissue weights of mice were all significantly lower in the HF + AC than in the HF. Arctiin administration also decreased the sizes of lipid droplets in the epididymal adipose tissue. CONCLUSIONS: Arctiin inhibited adipogenesis in 3T3-L1 adipocytes through the inhibition of PPARgamma and C/EBPalpha and the activation of AMPK signaling pathways. These findings suggest that arctiin has a potential benefit in preventing obesity.
Subject(s)
Animals , Mice , 3T3-L1 Cells , Adenylate Kinase , Adipocytes , Adipogenesis , Adipose Tissue , Adiposity , AMP-Activated Protein Kinases , Blotting, Western , Body Weight , Diet , Diet, High-Fat , Intra-Abdominal Fat , Lipoprotein Lipase , Mice, Obese , Obesity , Phosphorylation , PPAR gamma , Sterol Regulatory Element Binding Protein 1 , Triglycerides , Weights and MeasuresABSTRACT
Obesity, an intractable metabolic disease, currently has no medical treatment without side effects, so studies have been actively carried out to find natural compounds that have anti-obesity activity with minimum side effects. In this study, the anti-obesity effects of water extracts of seven Capsicum annuum L. varieties being Putgochu (Pca), Oyee gochu (Oca), Kwari putgochu (Kca), Green pepper (Gca), Yellow paprika (Yca), Red paprika (Rca) and Cheongyang gochu (Cca), were examined through the evaluation of lipoprotein lipase (LPL) mRNA expression level in 3T3-L1 cells (mouse pre-adipocytes). After capsaicin elimination by chloroform defatting, freeze-dried powder of Cca was treated to 3T3-L1 cells and anti-obesity effects were examined by determining the LPL mRNA level using the RT-PCR method. Of the primary fractions, only proven fractions underwent secondary and tertiary refractionating to determine anti-obesity effects. From seven different Capsicum annuum L., there was a significant decrease of the LPL mRNA expression level of 50.9% in Cca treatment compared to the control group. A significant decrease of the LPL mRNA expression level was shown in primary fractions (Fr) 5 (36.2% decrease) and 6 (30.5% decrease) of the Cca water extracts. Due to the impurities checked by UPLC chromatography, Fr 5 and 6 were refractionated to determine the LPL mRNA expression level. Treatment of Fr 6-6 (35.8% decrease) and Fr 5-6 (35.3% decrease) showed a significant decrease in the LPL mRNA expression level. When analyzed using UPLC, major compounds of Fr 6-6 and Fr 5-6 were very similar. Subsequently, we refractionated Fr 6-6 and Fr 5-6 to isolate the major peak for structure elucidation. Treatment of Fr 5-6-1 (26.6% decrease) and Fr 6-6-1 (29.7% decrease) showed a significant decrease in the LPL mRNA expression level. Consequently, the fractions may have a possibility to ameliorate obesity through the decrease of the LPL mRNA expression level.
Subject(s)
3T3-L1 Cells , Capsaicin , Capsicum , Chloroform , Chromatography , Lipoprotein Lipase , Lipoproteins , Metabolic Diseases , Obesity , RNA, Messenger , WaterABSTRACT
The aim of this study was to investigate whether a water extract of L. cladonioides (LC) has an anti-obesity effect in 3T3-L1 cells and obese mice. Treatment of differentiated 3T3-L1 adipocytes with LC caused a significant increase in glycerol release and reduced the protein expression of the adipogenic transcription factors, PPARgamma and C/EBPalpha. In an animal model, obese mice were artificially induced by a high fat diet for 10 weeks. Experimental groups were treated with LC (100 mg/kg/day) by gavage for the next 10 weeks. At the end of experiment, the body weight of the LC group mice was reduced by 14.2% compared to the high fat diet (HFD) group. The treatment also decreased liver (31.0%), epididymal (18.0%) and retroperitoneal (19.3%) adipose tissue, and kidney (6.7%) weights, respectively, compared with those of the HFD group. LC prevented diet-induced increases in the serum level of TC (22.6%), TG (11.6%), and glucose (35.0%), respectively, compared with the HFD group. However, the HDL-C level was higher in the LC group (26.1%) than the HFD group. The results of this study thus suggest that LC suppressed lipid accumulation and expression of adipogenic transcription factors, and increased the amount of glycerol release. LC also indicated an anti-obese and anti-hyperlipidemic effect.
Subject(s)
Animals , Mice , 3T3-L1 Cells , Adipocytes , Adipose Tissue , Body Weight , Diet, High-Fat , Glucose , Glycerol , Kidney , Liver , Mice, Obese , Models, Animal , Obesity , PPAR gamma , Transcription Factors , Water , Weights and MeasuresABSTRACT
Objective: To observe the expression changes of protein tyrosine phosphatase 1B (PTP1B) mRNA and protein during the differentiation of 3T3-L1 preadipocytes, so as to explore the relationship between PTP1B and adipocytes differentiation. Methods: 3T3-L1 preadipocytes were cultured in vitro and were induced to differentiate into mature adipocytes; the differentiation of adipocytes was assessed through detecting expression of peroxisome proliferator-activated receptor-gamma 2 (PPARγ2) mRNA by RT-PCR and oil red O staining. Expression of PTP1B in adipocytes was detected by RT-PCR and Western blot during differentiation. Results: With the progression of 3T3-L1 cell differentiation, oil red O staining showed that the lipid droplets increased gradually to 90% of the vision field; meanwhile, the expression of PPARγ2 also increased gradually, suggesting the proliferation and maturation of the preadipocytes. The expression of PTP1B mRNA and protein decreased in 3T3-L1 preadipocytes with their differentiation and maturation; the expression reached the lowest level in mature adipocytes. Conclusion: Expression of PTP1B mRNA and protein decreases during the differentiation of preadipocytes, indicating a role for PTP1B in the maturation of adipocytes.
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Objective To observe the effects of JAZF1 (Juxtaposed with another zinc finger gene 1 ) overexpression on glucose and lipid metabolism in 3T3-L1 adipocytes. Methods The tissue distribution of JAZF1 in healthy C57BL/6J mice was detected by real-time quantitative PCR( RT-QPCR). Expression vector for JAZF1 gene was constructed and transfected into 3T3-L1 adipocytes. The mRNA levels of JAZF1, GLUT1, GLUT4, FAS, ACC, SREBP1, ATGL, and HSL implicated in glucose and lipid metabolism were determined by RT-QPCR; JAZF1 protein level was measured by Western blot. Intracelluar lipid accumulation were measured by oil red O staining method. Results In JAZF1-transfected adipocytes, JAZF1 mRNA and protein levels were significantly higher than control cells after 48 h. The mRNA level of HSL was increased significantly (P<0. 05) in JAZF1 transfection group compared with negative control and empty vector group, and the expressions of FAS, ACC, SREBP1 mRNA were decreased significantly(all P<0.01). However, the mRNA levels of ATGL, GLUT1, GLUT4 were not changed. Intracelluar lipid accumulation was decreased significantly (P<0.05 ) by oil red O staining and colorimetric in JAZF1 -transfected cells compared with negative control and empty vector group. Conclusions There was an extensive expression of JAZF1 in various tissues of C57BL/6J mice,indicating that JAZF1 might play a role in maintaining normal physiological function. These results show that overexpression of JAZF1 in 3T3-L1 cells can reduce lipid synthesis, increase lipolysis, and improve lipid accumulation. JAZF1 might provide a new potential therapeutic target for obesity and diabetes.
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Treatment of AIDS (HIV) and hepatitis C virus needs protease inhibitors (PI) to prevent viral replication. Uses of PI in therapy are usually associated with a decrease in body weight and dyslipidemia. Acylation stimulating protein (ASP) is a protein synthesized in adipocytes to increase triglycerides biosynthesis, for that the relation of PI and ASP to adipogenesis is tested in this work. ASP expression was increased during 3T3-L1 differentiation and reached a peak at day 8 with cell maturation. Addition of PI during adipocytes differentiation dose dependently and significantly (p < 0.5) inhibited the degree of triglycerides (TG) accumulation. Moreover, presence of ASP (450 ng/mL) in media significantly (p < 0.5) stimulated the degree of TG accumulation and there was additive stimulation for ASP when added with insulin (10 microgram/mL). Finally, when ASP in different doses (Low, 16.7; Medium, 45 and High, 450 ng/mL) incubated with a dose of x150 PI, ASP partially inhibited the PI-inhibited adipogenesis and TG accumulation. The results in this study show that PI inhibit lipids accumulation and confirm role of ASP in TG biosynthesis and adipogenesis.
Subject(s)
Animals , Mice , 3T3 Cells , Adipogenesis/drug effects , Gene Expression Regulation/drug effects , Hypoglycemic Agents/pharmacology , Insulin/pharmacology , Intercellular Signaling Peptides and Proteins/pharmacology , Lipid Metabolism/drug effects , Protease Inhibitors/pharmacology , Time FactorsABSTRACT
To identify regulatory molecules which play key roles in the development of obesity, we investigated the transcriptional profiles in 3T3-L1 cells at early stage of differentiation and analyzed the promoter sequences of differentially regulated genes. One hundred and sixty-one (161) genes were found to have significant changes in expression at the 2nd day following treatment with differentiation cocktail. Among them, 86 transcripts were up-regulated and 75 transcripts were down-regulated. The 161 transcripts were classified into 10 categories according to their functional roles; cytoskeleton, cell adhesion, immune, defense response, metabolism, protein modification, protein metabolism, regulation of transcription, signal transduction and transporter. To identify transcription factors likely involved in regulating these differentially expressed genes, we analyzed the promoter sequences of up- or -down regulated genes for the presence of transcription factor binding sites (TFBSs). Based on coincidence of regulatory sites, we have identified candidate transcription factors (TFs), which include those previously known to be involved in adipogenesis (CREB, OCT-1 and c-Myc). Among them, c-Myc was also identified by our microarray data. Our approach to take advantage of the resource of the human genome sequences and the results from our microarray experiments should be validated by further studies of promoter occupancy and TF perturbation.
Subject(s)
Humans , 3T3-L1 Cells , Adipogenesis , Binding Sites , Cell Adhesion , Cytoskeleton , Gene Expression Profiling , Genome, Human , Metabolism , Microarray Analysis , Obesity , Signal Transduction , Transcription Factors , TranscriptomeABSTRACT
Aquaporin adipose (AQPap) is the physiological glycerol channel specific to adipocytes. By means of semiquantitive RT-PCR and Western blotting, this study showed that insulin was a negative regulator of AQPap expression, while high concentration of glucose could increase AQPap expression.
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The effects of pioglitazone (PIO) and tumor necrosis faetor-?(TNF-?) on two kinds of adiponectin receptor (AdipoR) mRNA expression were observed in 3T3-L1 adipocytes by RT-PCR.AdipoR mRNA expression was up-regulated during 3T3-L1 preadipocyte differentiation;PIO could increase the AdipoR mRNA level expressed in undifferentiated and differentiated 3T3-L1 adipocytes in a time-and dose-dependent manner,and TNF-?had no influence on the expression of AdipoR mRNA.
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Objective:To observe the expression changes of protein tyrosine phosphatase 1B(PTP1B)mRNA and protein during the differentiation of 3T3-L1 preadipocytes,so as to explore the relationship between PTP1B and adipocytes differentiation.Methods:3T3-L1 preadipocytes were cultured in vitro and were induced to differentiate into mature adipocytes; the differentiation of adipocytes was assessed through detecting expression of peroxisome proliferator-activated receptor-gamma 2(PPAR?2)mRNA by RT-PCR and oil red O staining.Expression of PTP1B in adipocytes was detected by RT-PCR and Western blot during differentiation.Results:With the progression of 3T3-L1 cell differentiation,oil red O staining showed that the lipid droplets increased gradually to 90% of the vision field;meanwhile,the expression of PPAR?2 also increased gradually, suggesting the proliferation and maturation of the preadipocytes.The expression of PTP1B mRNA and protein decreased in 3T3-L1 preadipocytes with their differentiation and maturation;the expression reached the lowest level in mature adipocytes. Conclusion:Expression of PTP1B mRNA and protein decreases during the differentiation of preadipocytes,indicating a role for PTP1B in the maturation of adipocytes.