We aimed to examine the effect of pioglitazone on transdifferentiation of preosteoblasts from rat bone marrow mesenchymal stem cells (BMSCs) into adipocytes and investigate its effect on bone metabolism. BMSCs were harvested from the femurs and tibias of a rat, then separated, purified, proliferated for 3 generations and differentiated into preosteoblasts for 5 days and 14 days respectively in the presence of osteogenic medium. Thereafter, the preosteoblasts were cultured for 21 days in the presence of adipogenic medium with and without pioglitazone (1 μg/mL). Partially-differentiated osteoblasts were identified by mineralized nodules with Alizarin red S staining. Transdifferentiated adipocytes were identified by Oil Red O staining. Reverse transcription PCR (RT-PCR) was performed to assay the expression levels of osteogenic markers Runx2 and ALP, and an adipogenic marker PPARγ. Those cells cultured for 5 days did not show mineralized nodules as detected by staining of Alizarin red S, while those cultured for 14 days showed dispersed mineralized centers in the form of brown spots, although without obvious red mineralized nodules. After adipogenic transdifferentiation for 21 days, adipose-drops were found in cells of 5CG and 5EG earlier than those of 14CG and 14EG, and the former showed much more adipocytes separately as detected by Oil Red O staining. Whatever the time was 5 days or 14 days of BMSCs osteogenic differentiation, the cells cultured with pioglitazone showed much more adipocytes than those without pioglitazone. Our experiment showed that the less time it took for BMSCs osteogenic differentiation, a stronger ability remained for BMSCs to transdifferentiate into adipocytes. The mRNA expression levels of Runx2 and ALP were decreased by 1.79 and 1.90 times respectively in 5EG (P< 0.05) as compared with 5CG, and that of PPARγ was increased by 1.31 times in 5EG (P<0.05) as compared with 5CG. The mRNA expression levels of Runx2 and ALP were decreased by 1.45 and 1.54 times respectively in 14EG (P<0.05) as compared with 14CG, and that of PPARγ was increased by 1.39 times in 14EG (P<0.05) as compared with 14CG. It was concluded that pioglitazone stimulated the transdifferentiation of BMSCs into adipocytes. These observations provided a potential mechanism of imbalance in thiazolidinedione induced bone metabolism.
Adipocytes ; drug effects ; Animals ; Cell Transdifferentiation ; drug effects ; Female ; Male ; Mesenchymal Stromal Cells ; drug effects ; Osteoblasts ; drug effects ; Osteogenesis ; drug effects ; Rats ; Rats, Sprague-Dawley ; Thiazolidinediones ; pharmacology

Objective To explore the effect of the action time of inducers on the differentiation of 3T3-L1 cells to adipocytes. Methods According to the "Cocktail" method,3T3-L1 cells were divided into three groups according to the action time of inducers,with the action time being 2,3 or 4 days,respectively. Cell morphology was observed using inverted microscope and adipose content were detected by Oil red "O" staining and detection of triglyceride. The cell viability was identified by trypan blue staining method. Results The proportion of samples (n=12) with differentiation rate above 80% in group A was 66% (12/18),while the differentiation rate of all the samples (n=18)in group B and group C were above 80%. For the Oil red "O",the OD value at 510 nm in group C was 2.59±0.17,which was significantly higher than that in group A (2.12±0.47;F=6.62,P=0.0001)and group B (2.20±0.17;F=5.15,P=0.0001),while no significant difference was found between group A and group B (F=1.14,P=0.74). As for the triglyceride,the value in group C was (1351.04±119.01)ng/ml,which was significantly higher than that in group A[ (1077.88±272.75)ng/ml;F=6.73,P=0.001] and group B [(1089.38±115.39)ng/ml;F=5.78,P=0.001],while no difference was found between group A and group B (F=0.27,P=0.64). The cell viability in group A,B,and C was (98.3±1.2)%,(98.5±1.8)%,and (98.9±2.1)%,respectively,showing no significant difference (F=0.18,P=0.83). Conclusions The modified procedure for the differentiation of 3T3-L1 cells to adipocytes can increase the differentiation rate and thus may be applied for establishing adipocyte models. The recommended action time is three days.
3T3-L1 Cells ; Adipocytes ; cytology ; drug effects ; Animals ; Cell Culture Techniques ; Cell Differentiation ; drug effects ; Mice ; Time Factors

To explore the effect of chronic high dose of insulin on lipolysis in porcine adipocytes and the underlying molecular regulation mechanisms, we cultured primary porcine adipocytes and incubated them with different concentrations of insulin (0, 200, 400, 800, 1600 nmol/L) for 24-96 h in the absence or presence of specific protein kinase A (PKA) inhibitor or extracellular signal-related kinase (ERK) inhibitor. Then, we measured the glycerol release into the culture media as an indicator of the lipolysis, and observed the lipid accumulation morphology by phase-contrast microscopy. Further, we analyzed the gene expressions of perilipin A and peroxisome proliferator-activated receptor-gamma 2 (PPAR gamma 2) with semi-quantitative RT-PCR and Western blotting, respectively. The results showed that chronic high dose of insulin stimulated lipolysis in differentiated porcine adipocytes in a dose- and time-dependent manner, and significantly attenuated the lipolytic response to isoprenaline. Meanwhile, the protein and mRNA expressions of PPAR gamma 2 and perilipin A were significantly reduced. In addition, both PKA and ERK inhibitors significantly suppressed insulin-stimulated lipolysis, however, only ERK inhibitor reversed the insulin-induced down-regulation of perilipin A. These findings imply that chronic high dose of insulin stimulates lipolysis in porcine adipocytes by repressing perilipin A, which is involved in ERK pathway.
Adipocytes ; cytology ; drug effects ; metabolism ; Animals ; Carrier Proteins ; Dose-Response Relationship, Drug ; Down-Regulation ; drug effects ; Insulin ; pharmacology ; Lipolysis ; drug effects ; Perilipin-1 ; Phosphoproteins ; metabolism ; Swine

To study insulino-mimetic effects of bis(alpha-furancarboxylato) oxovanadium (IV) (BFOV), a orally active antidiabetic vanadyl complex, on glucose uptake and lipogenesis in isolated rat adipocytes were determined by using 2-deoxy-D-[3H]-glucose and D-[3H]-glucose, respectively. Lipolysis was assayed by free fatty acids (FFA) released from isolated rat adipocytes treated with epinephrine. The results showed that BFOV, similar to insulin, concentration-dependently significantly enhanced the uptake of 2-deoxy-D-[3H]-glucose and the transformation from D-[3H]-glucose to lipid in isolated rat adipocytes, with the EC50 values of (0.31 +/- 0.08) mmol L(-1) and (0.49 +/- 0.12) mmol L(-1), respectively. Moreover, BFOV markedly inhibited FFA release from isolated rat adipocytes treated with epinephrine, and the IC50 value was (0.30 +/- 0.20) mmol L(-1). BFOV had insulino-mimetic effects such as enhancing glucose uptake and lipogenesis, as well as inhibiting lipolysis.
Adipocytes ; drug effects ; metabolism ; Animals ; Blood Glucose ; drug effects ; Hypoglycemic Agents ; pharmacology ; Insulin ; pharmacology ; Lipogenesis ; drug effects ; Male ; Organometallic Compounds ; pharmacology ; Rats ; Rats, Sprague-Dawley

Adipocytes ; cytology ; Cell Line ; Endothelial Cells ; cytology ; drug effects ; Epithelial-Mesenchymal Transition ; drug effects ; Humans ; Melatonin ; pharmacology ; Mesenchymal Stromal Cells ; cytology ; drug effects ; metabolism

OBJECTIVETo explore the feasibility of inducing the differentiation of human adipose tissue-derived stem cells (ADSCs) into Leydig cells in vitro.

METHODSWe isolated ADSCs by digestion with Collagenase I from the subcutaneous adipose tissue, cultured them in the DMEM/F12 medium with 10% fetal bovine serum, and detected the expression of vimentin by immunohistochemistry. We exposed the ADSCs to different concentrations of human chorionic gonadotropin (HCG) for different times, determined the expression of StAR mRNA by real-time PCR, and measured the HCG-induced proliferation of ADSCs by MTT. After a week of induction by HCG and DMSO, we conducted 3beta-HSD immunohistochemistry, and detected the testosterone level in the supernatant and lysis of the cells by radioimmunoassay.

RESULTSThe ADSCs grew well with a positive expression of vimentin. The expression of the StAR gene was positively correlated with the increased concentration of HCG, reaching the peak at HCG 10 U/ml in 1 week culture. The proliferation of ADSCs was significantly increased by HCG induction. A positive expression of 3beta-HSD was observed after 1 week induction with HCG 10 U/ml and DMSO 3.2 x 10(-6)mol/L.

CONCLUSIONHCG enhances the expression of the StAR gene and the proliferation of ADSCs. Induced by HCG 10 U/ml and DMSO 3.2 x 10(-6) mol/L, ADSCs tend to differentiate into Leydig cells.

Adipocytes ; cytology ; drug effects ; Cell Culture Techniques ; Cell Differentiation ; drug effects ; Cells, Cultured ; Chorionic Gonadotropin ; pharmacology ; Humans ; Leydig Cells ; cytology ; drug effects ; Male

OBJECTIVETo observe the effects of panax quinquefolius saponin (PQS) of stem and leaf on glucose-lipid metabolism and insulin signal transduction in the insulin resistant model of adipocytes.

METHODSThe insulin resistant model of differentiated 3T3-L1 adipocytes was established in vitro with free fatty acid. After induction of insulin resistance, cells were treated with metformin or PQS for 2 days. The glucose consumption in culture fluid was detected by glucose oxidase method; the effects of PQS on the lipolysis induced by tumor necrosis factor (TNF-alpha) was observed using colorimetry; and the phospholation of signal proteins was detected by Western-blot.

RESULTSThe amount of glucose consumption (mmol/L) in the model group (5.250 +/- 2. 671) was significantly lower than that in the normal control group (14.133 +/- 1.305, P < 0.01), it increased in the meformin treated group (11.807 +/- 1.358), and the groups treated with high-, middle- and low-dose PQS dose-dependently (10.784 +/- 2.373, 10.217 +/- 1.237 and 9.984 +/- 2.006, respectively), significantly higher than that in the model group (P < 0.01). Upon TNF-alpha treatment, the concentration of free fatty acid (FFA) (nmol/ microg) in culture medium was 2.479 +/- 0.597, predominantly higher than that in the control group (1.320 +/- 0.538, P < 0.01), while it was 1.210 +/- 0.566 in the metformin group, 1.105 +/- 0.631 in high-dose PQS group, 1.108 +/- 0.260 in the middle-dose PQS group, 1.201 +/- 0.593 in the low-dose PQS group, all were lower than that in the TNF-alpha group (P < 0.05 or P < 0.01), and a dose-dependent tendency of PQS's action was seen. The tyrosine phosphorylation of insulin receptor and IRS-1 as well as Ser473 phosphorylation of PKB were lower in the model group than in the control group; they were insignificantly changed in the low-dose PQS group, but did show significant difference in comparing with those in the high-and middle-dose PQS groups or metformin group.

CONCLUSIONPQS can accelerate the glucose utilization and depress the lipolysis in adipocytes induced by TNF-alpha, which may be correlated with its promoting insulin signal transduction and improving insulin resistance in adipocytes.

3T3-L1 Cells ; Adipocytes ; drug effects ; metabolism ; Animals ; Glucose ; metabolism ; Insulin ; metabolism ; Insulin Resistance ; Lipid Metabolism ; drug effects ; Mice ; Saponins ; pharmacology ; Signal Transduction ; drug effects

PURPOSE: Ascorbic acid has been reported to have an adipogenic effect on 3T3-L1 preadipocytes, while evidence also suggests that ascorbic acid reduces body weight in humans. In this study, we tested the effects of ascorbic acid on adipogenesis and the balance of lipid accumulation in ovariectomized rats, in addition to long-term culture of differentiated 3T3-L1 adipocytes. MATERIALS AND METHODS: Murine 3T3-L1 fibroblasts and ovariectomized rats were treated with ascorbic acid at various time points. In vitro adipogenesis was analyzed by Oil Red O staining, and in vivo body fat was measured by a body composition analyzer using nuclear magnetic resonance. RESULTS: When ascorbic acid was applied during an early time point in 3T3-L1 preadipocyte differentiation and after bilateral ovariectomy (OVX) in rats, adipogenesis and fat mass gain significantly increased, respectively. However, lipid accumulation in well-differentiated 3T3-L1 adipocytes showed a significant reduction when ascorbic acid was applied after differentiation (10 days after induction). Also, oral ascorbic acid administration 4 weeks after OVX in rats significantly reduced both body weight and subcutaneous fat layer. In comparison to the results of ascorbic acid, which is a well-known cofactor for an enzyme of collagen synthesis, and the antioxidant ramalin, a potent antioxidant but not a cofactor, showed only a lipolytic effect in well-differentiated 3T3-L1 adipocytes, not an adipogenic effect. CONCLUSION: Taking these results into account, we concluded that ascorbic acid has both an adipogenic effect as a cofactor of an enzymatic process and a lipolytic effect as an antioxidant.
3T3-L1 Cells ; Adipocytes/drug effects ; Adipocytes/metabolism ; Adipogenesis/drug effects ; Animals ; Antioxidants/pharmacology ; Ascorbic Acid/pharmacology ; Body Composition/drug effects ; Body Weight/drug effects ; Cell Differentiation/drug effects ; Female ; Fibroblasts/drug effects ; Fibroblasts/metabolism ; Lipolysis/drug effects ; Mice ; Ovariectomy ; Rats, Sprague-Dawley

OBJECTIVETo study the effect of emodin (EMO) on the proliferation and differentiation of rat preadipocytes.

METHODSeparating and culturing rat preadipocytes, grouping the wells that preadipocytes were growing according to certain concentration such as 0, 5, 10, 20, 40, 80, 160 micromol x L(-1) randomly, MTT spectrophotometry and flow cytometry (FCM) were adopted to determine the effect of EMO on proliferation of rat preadipocytes. The accumulation of TG (triglyceride) in adipocytes was assayed by oil red O staining, and the morphological changes of the adipocytes were determined by morphology observation.

RESULTEMO in the range of 20-160 micromol x L(-1) could inhibit the proliferation and differentiation of preadipocytes in a dose and time dependent manner, and induce apoptosis of preadipocytes in a certain degree.

CONCLUSIONEMO should have a potential to serve as a fat-reducing drug.

Adipocytes ; cytology ; drug effects ; Animals ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Emodin ; administration & dosage ; pharmacology ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley

This study was aimed to explore the regulation of arsenic trioxide (As₂O₃) on imbalance between adipogenic and osteogenic differentiation of BM-MSC from patients with aplastic anemia(AA). The BM-MSC from AA patients were separated and purified, placed into the adipogenic and osteogenic differentiation culture system, then added the As₂O₃, CsA, As₂O₃combined with CsA were added to corresponding differentiation culture system, the concentration of As₂O₃and CsA were set at 0.001 µmol/ml and 2.5 mmol/ml respectively, the cells were divided into As₂O₃group, the CsA group, combined group and control group (no drug). The cell morphological observation, oil red 'O' staining, Von-Kossa staining, and RT-PCR were used to detect corresponding differentiation marks. The results indicated that in respect to adipogenic differentiation, cellular morphology observing and oil red 'O' staining showed that the rate of adipocyte differentiation in As₂O₃group was (18.3 ± 1.9)%, which was lower than the (91.8 ± 2.7)% in the CsA group and (92.1 ± 1.2)% in control group (P < 0.05), there was no significant difference in comparison with (8.3 ± 1.9)% in the combined group (P > 0.05), but the rate of differentiation in CsA group was higher than that in combined group (P < 0.05), and there was no significant difference in comparison wtih control group. RT-PCR showed that the LPL-mRNA expression level in As₂O₃group were significantly lower than that in the CsA group and the control group (P < 0.05), no difference was observed while compared with the combined group (P > 0.05), but the LPL-mRNA expression level in CsA group was significantly higher than that in the combined group (P < 0.05). In terms of osteogenetic differentiation, the calcium deposition in As₂O₃group and combined group was obviously observed while rarely in the CsA group and the control group when detected by the Von-Kossa staining. OST-mRNA expression level in As₂O₃group were higher than that in CsA group and the control group (P < 0.05), while compared with the combined group, there was no significant difference (P > 0.05), but the OST-mRNA expression level in the CsA group was lower than that in the combined group (P < 0.05). It is concluded that As₂O₃can significantly enhance the ability of BM-MSC from AA patients to differentiate into osteoblast, also can inhibit the adipogenic differentiation, in contrast, the CsA can not promote the osteoblast differentiation of BM-MSC from AA patients.
Adipocytes ; cytology ; drug effects ; Anemia, Aplastic ; pathology ; Arsenicals ; pharmacology ; Bone Marrow ; drug effects ; Cell Differentiation ; drug effects ; Cells, Cultured ; Humans ; Mesenchymal Stromal Cells ; cytology ; drug effects ; Osteoblasts ; Osteogenesis ; drug effects ; Oxides ; pharmacology