OBJECTIVE: To establish a simple, low-cost and time-saving method for primary culture of mature white adipocytes from mice. METHODS: Mature white adipocytes were isolated from the epididymis and perirenal area of mice for primary culture using a modified mature adipocyte culture method or the ceiling culture method. The morphology of the cultured mature adipocytes was observed using Oil Red O staining, and the cell viability was assessed with CCK8 method. The expression of PPARγ protein in the cells was detected with Western blotting, and the mRNA expressions of CD36, FAS, CPT1A and FABP4 were detected using RT-qPCR. RESULTS: Oil Red O staining showed a good and uniform morphology of the adipocytes in primary culture using the modified culture method, while the cells cultured using the ceiling culture method exhibited obvious morphological changes. CCK8 assay showed no significant difference in cell viability between freshly isolated mature white adipocytes and the cells obtained with the modified culture method. Western blotting showed that the freshly isolated adipocytes and the cells cultured for 72 h did not differ significantly in the expression levels of PPARγ protein (P=0.759), which was significantly lowered in response to treatment with GW9662 (P < 0.001). GW9662 treatment of the cells upregulated mRNA expressions of CD36 (P < 0.001) and CPT1A (P=0.003) and down-regulated those of FAS (P=0.001) and FABP4 (P < 0.001). CONCLUSION We established a convenient and time-saving method for primary culture mature white adipocytes from mice to facilitate further functional studies of mature adipocytes.
Male ; Mice ; Animals ; Adipocytes, White/metabolism* ; PPAR gamma/metabolism* ; RNA, Messenger ; Cell Differentiation ; 3T3-L1 Cells

OBJECTIVETo investigate the effects of rapamycin on cholesterol homeostasis and secretory function of 3T3-L1 cells.

METHODSThe in vitro cultured 3T3-L1 cells (preadipocytes) were divided into control group, rapamycin 50 nmol/L group, rapamycin 100 nmol/L group, and rapamycin 200 nmol/L group. Intracellular cholesterol level was measured by oil red O staining and high performance liquid chromatography. The secretion levels of leptin and adiponectin were assayed by enzyme-linked immunosorbent assay. The mRNA and protein expressions of peroxisome proliferator-activated receptor (PPARgamma) were assayed by quantitative real-time polymerase chain reaction and Western blot.

RESULTSOil red O staining showed rapamycin down-regulated 3T3-L1 cells differentiation and lipid accumulation. Quantitative measurement of cholesterol with high performance liquid chromatography showed that the concentrations of free cholesterol in rapamycin treatment groups had a significant reduction. The concentrations of free cholesterol in the control group, rapamycin 50 nmol/L group, rapamycin 100 nmol/L group, and rapamycin 200 nmol/L group were (12.89 +/- 0.16), (9.84 +/- 0.45), (9.39 +/- 0.46), and (8.61 +/- 0.34) mg/ml, respectively (P < 0.05), and the concentrations of total cholesterol were (12.91 +/- 0.50), (9.94 +/- 0.96), (10.45 +/- 2.51), and (9.53 +/- 0.63) mg/ml, respectively. The leptin concentrations in the control group, rapamycin 50 nmol/L group, rapamycin 100 nmol/L group, and rapamycin 200 nmol/L group were (19.02 +/- 0.52), (16.98 +/- 0.11), (15.62 +/- 0.01), and (13.84 +/- 0.66) ng/ml, respectively. The mRNA expressions of PPARgamma in the rapamycin 50 nmol/L group, rapamycin 100 nmol/L group, and rapamycin 200 nmol/L group were significantly lower than that in control group (P < 0.05). The protein expressions of PPARgamma in the rapamycin 50 nmol/L group, rapamycin 100 nmol/L group, and rapamycin 200 nmol/L group were 80%, 74%, and 61% of that in control group (P < 0.05). After the cells were treated with rapamycin 100 nmol/L, PPARgamma blocking agent GW9662 10 micromol/L, and PPARgamma agonist troglitazone 10 micromol/L, respectively, for 96 hours, the mRNA expression of PPARgamma was (0.60 +/- 0.14), (0.67 +/- 0.03), and (1.30 +/- 0.14) of that in control group (P < 0.05). The protein expression showed a similar trend with mRNA expression (P < 0.05). After the cells were treated with rapamycin 100 nmol/L, PPARgamma blocking agent GW9662 10 micromol/L, and PPARgamma agonist troglitazone 10 micromol/L, respectively, for 96 hours, the expression of leptin in the control group, rapamycin 50 nmol/L group, rapamycin 100 nmol/L group, and rapamycin 200 nmol/L group was (19.02 +/- 0.52), (15.62 +/- 0.10), and (14.45 +/- 1.01) and (18.07 +/- 0.66) ng/ml, respectively (P < 0.05 compared with the control group).

CONCLUSIONSBy downregulating the expression of PPARgamma, rapamycin can decrease cholesterol accumulation in 3T3-L1 cells and inhibit its leptin-secreting capability. This finding may provide a possible explanation for rapamycin-induced hyperlipidemia in clinical practice.

3T3-L1 Cells ; Adipocytes ; drug effects ; metabolism ; Animals ; Cholesterol ; metabolism ; Leptin ; metabolism ; Mice ; PPAR gamma ; genetics ; metabolism ; Sirolimus ; pharmacology

AIMTo establish a HSP90 highly expressing cell line and study the effect of high level of HSP90 on cell stress response.

METHODSThe recombined plasmid pSmycHSP, which contained the full length DNA coding for human HSP90 B, was introduced into mouse fibroblast cell line NIH-3T3 by electroporation after being subcloned, purified and identified by limited enzyme digestion. After screened by G418, the positive clones were selected and identified by immunocytochemistry and Western-blotting. Contrasted with NIH-3T3 cells transfected with empty plasmid, the effect of high-level HSP90 on cell proliferation and cell cycle was analyzed by MTT method and flow cytometry.

RESULTSThe rising level of HSP90 was shown by immunocytochemistry and Western-blotting. Compared with control, the growth of HSP90 highly expressing cell line slowed down and the DNA content of S phase was lower.

CONCLUSIONThe NIH-3T3 derived cell line, which stably expressed high level of HSP90 was established. The effect of high-level HSP90 on cell proliferation was to retard cell growth by affecting cell cycle.

Animals ; Cell Cycle ; Cell Proliferation ; HSP90 Heat-Shock Proteins ; metabolism ; Mice ; NIH 3T3 Cells

BACKGROUNDTo construct recombinant vector expressing antisense RNA to CCR5 in eukaryotic cells and obtain recombinant pseudovirus, which will be used to block HIV-1 infection.

METHODSThe DNA fragment targeted against the initional part of CCR 5 mRNA translation was amplified by using RT-PCR from peripheral blood mononuclear cells (PBMCs) and cloned into retroviral vector pLXSN, then transfected into packaging cell (PA317) with lipofectAMINE. After 2-3 weeks selecting with G418, the pseudovirion in the survival cell's supernatant was detected with RT-PCR (FQ),then was used to infect NIH/3T3 cell.

RESULTSThe psuedovirion packed from expression vector of sense/antisense RNA to CCR5 had infected NIH/3T3 cell successfully. The vector had incorporated into its genome and transcripted into RNA.

CONCLUSIONSThe gene fragment of antisense RNA to CCR5 could be obtained from PBMCs and transfected into eukaryotic cell with retroviral vector. The results made a great foundation for studying its inhibiting effect on HIV-1 infection.

3T3 Cells ; Animals ; Eukaryotic Cells ; metabolism ; Gene Expression ; Genetic Vectors ; Mice ; Plasmids ; genetics ; RNA, Antisense ; genetics ; Receptors, CCR5 ; genetics ; Transfection

To examine the role of ultrasound in gene delivery in vitro, three cells lines were exposed to the low-frequency ultrasound of varying intensities and for different durations to evaluate their effect on gene transfection and cell viability of the cells. Microbubble (MB), Optison (10%), was also used to observe the role of the microbubbles in gene transfection. The results demonstrated that as the ultrasound intensity and the exposure time increased, the gene transfer rate increased and the cell viability decreased, but at high energy intensities, the cell viability decreased dramatically, which caused the transfer rate to decrease. The most efficient ultrasound intensity for inducing gene transfer was 1 W/cm(2) with duration being 20 s. At the same energy intensity, higher ultrasound intensity could achieve maximal gene transfer rate earlier. Microbubbles could increase ultrasound-induced cell gene transfer rate by about 2 to 3 times mainly at lower energy intensities. Moreover, microbubbles could raise the maximum gene transfer rate mediated by ultrasound. It is concluded that the low-frequency ultrasound can induce cell gene transfer and the cell gene transfer rate and viability are correlated with not only the ultrasound energy intensity but also the ultrasound intensity, the higher ultrasound intensity achieves its maximal transfer rate more quickly and the ultrasound intensity that can induce optimal gene transfer is 1 W/cm(2) with duration being 20 s, and microbubbles can significantly increase the maximal gene transfer rate in vitro.
3T3 Cells ; CHO Cells ; Cell Line ; Cell Survival/*genetics ; Contrast Media/metabolism ; Cricetinae ; Cricetulus ; Microbubbles ; Transfection/*methods ; Ultrasonics

OBJECTIVETo construct and identify the stable expression system of NIH3T3 fibroblast with eukaryotic expression vector of human transforming growth factor beta3 (pcDNA3.1 (-)/TGFbeta3). So as to investigate the proliferation of NIH3T3 fibroblasts transfected with hTGFbeta3 gene stably.

METHODSThe stable transfection of NIH3T3 fibroblasts with recombinant plasmid expressing hTGFbeta3 was established by using LipofectamineTM2000 and G418 selection. The mRNA and protein expression of TGFbeta3 were detected by the RT-PCR and Western blot method, respectively. Microscope and MTT were adopted to examine the proliferation of the stable expression system of fibroblasts with hTGFbeta3.

RESULTSAfter G418 selection, RT-PCR and Western blot analysis, 7 out of 10 cell lines transfected with pcDNA3.1 (-)/TGFbeta3 expressed with very high level of TGFbeta3, as compared with vector control transfectants that showed no expression, and compared with the other cell lines that expressed relatively low level. The stable transfection of NIH3T3 fibroblasts growth slowed down significantly (P < 0.05).

CONCLUSIONThe stable expression system of NIH3T3 fibroblast with hTGFbeta3 were constructed successfully. The TGFbeta3 gene could inhibit the proliferation of NIH3T3 fibroblasts in vitro.

Animals ; Cell Proliferation ; Fibroblasts ; metabolism ; Humans ; Mice ; NIH 3T3 Cells ; Plasmids ; Transfection ; Transforming Growth Factor beta3 ; genetics ; metabolism

OBJECTIVETo investigate the effects of GW4064, a farnesoid X receptor (FXR) agonist, on adiponectin and its receptors during the differentiation of 3T3-L1 preadipocytes and on adiponectin receptors in HepG2 cells.

METHODSThe mRNA expressions of FXR, PPARγ2, adiponectin, AdipoR1, and AdipoR2 and the protein levels of adiponectin on days 0, 2, 4, 6, and 8 during the differentiation of 3T3-L1 preadipocytes treated with GW4064 were detected by fluorescent real-time PCR and ELISA, respectively. The mRNA expressions of AdipoR1 and AdipoR2 in HepG2 cells were also examined at 0, 12, 24, and 48 h after GW4064 treatment.

RESULTSThe mRNA expressions of FXR, PPARγ2, adiponectin, and AdipoR2 in 3T3-L1 preadipocytes and AdipoR2 in HepG2 cells treated with GW4064 was significantly increased compared with the control group (all P<0.05). The protein level of adiponectin was also significantly increased after GW4064 treatment. The expression of AdipoR1 in either 3T3-L1 preadipocytes or HepG2 cells showed no significant changes after GW4064 treatment.

CONCLUSIONGW4064 can up-regulate the expressions of FXR, PPARγ2, adiponectin, AdipoR2 in 3T3-L1 preadipocytes and AdipoR2 in HepG2 cells. As adiponectin and its receptors are two important factors in the treatment of non-alcoholic fatty liver disease, FXR agonist may potentially produce therapeutic effect on non-alcoholic fatty liver disease and can regulate adipocytes via up-regulating PPARγ during adipocyte differentiation.

3T3-L1 Cells ; Adiponectin ; metabolism ; Animals ; Cell Differentiation ; drug effects ; Hep G2 Cells ; Humans ; Isoxazoles ; pharmacology ; Mice ; PPAR gamma ; metabolism ; Receptors, Adiponectin ; metabolism ; Receptors, Cytoplasmic and Nuclear ; agonists

In order to probe into the patho-physiology semicarbazide-sensitive amine oxidase (SSAO), we determined the variation of its activity in the days of 3T3-F442A cells' differentiation into adipocytes in vitro. The differentiated 3T3-F442A cells were collected in various days and disrupted by ultrasonication. Then we studied the SSAO activity of the collected cells by oxidase-linked spectrophotometric assay. In the course of 3T3-F442A cells' differentiation, SSAO expression was shown by a curve graph. There was no SSAO detected in 3T3-F442A preadipocyte, and only a little of SSAO was detected in the cells on the 3rd day of differentiation. Since then, SSAO significantly increased and reached to a maximum level six or seven days after the cells' differentiation.
3T3 Cells ; Adipocytes ; cytology ; enzymology ; Amine Oxidase (Copper-Containing) ; metabolism ; Animals ; Cell Differentiation ; physiology ; Mice ; Spectrophotometry ; methods

AIMTo investigate the effect of interleukin-8 (IL-8) on the differentiation and clonal expansion of 3T3-L1 preadipocyte during the differentiation period.

METHODSThe morphological changes of 3T3-L1 cells during differentiation after the treatment of IL-8 was observed by Oil-Red O staining. Glycerol-3-phosphate dehydrogenase (GPDH) activity was measured by a spectrophotometric method. MTT method and 3H-TdR incorporation were applied to examine the changes of cell proliferation and DNA synthesis in clonal expansion of 3T3-L1 cells. Cell cycle analysis was taken by flow cytometry.

RESULTSIL-8 could inhibit the differentiation and GDPH activity in a dose dependent manner. IL-8 decreased the cell proliferation and DNA synthesis in clonal expansion after induction. Also, the proportion of cells in G1 phase was increased and that of cells in S and G2 phase was declined after the treatment of IL-8.

CONCLUSIONIL-8 inhibits the differentiation of 3T3-L1 preadipocytes by decreasing the clonal expansion of the cells.

3T3-L1 Cells ; Adipocytes ; cytology ; metabolism ; Animals ; Cell Cycle ; Cell Differentiation ; Cell Proliferation ; drug effects ; Interleukin-8 ; pharmacology ; Mice

Phosphatidylinositol (PI) 3-kinase plays an important role in transducing the signals of various growth factor receptors. However, the regulatory mechanism of PI3-kinase activity by these growth factor receptors is not completely understood. Therefore, we attempted to clarify the regulatory mechanism of PI3-kinase using insulin and 3T3 L1 fibroblasts. Our results showed that insulin stimulated PI3-kinase activity seven-fold and concomitantly phosphorylated a p85 subunit at the tyrosine residue. However, this tyrosine phosphorylation was not significant in the activation of PI3-kinase as the PI3-kinase pulled down by the overexpressed GST-p85 fusion protein showed as high an activity as the immunoprecipitated one. The p110 subunit was phosphorylated at both serine and tyrosine residues without insulin treatment. Since the phosphorylation state was not changed by insulin. The results suggested that phosphorylation of the p110 subunit does not control PI3-kinase activity. Finally, it was shown that the insulin receptor substrate-1 (IRS-1) binding to PI3-kinase was not sufficient for full activation because the amount of IRS-1 pulled down by the GST-p85 fusion protein reached almost maximum, after incubation with insulin-treated cell lysates for 20 min, whereas PI3-kinase activity reached its maximum only after incubation for 5 h. All results suggest that the phosphorylation of p85 subunit at tyrosine residues and phosphorylation of p110 subunit at tyrosine or serine residues are not functionally significant in the regulation of PI3-kinase activity. They also suggest that P13-kinase is needed to bind to other protein(s) as well as the insulin receptor substrate-1 for full activation.
1-Phosphatidylinositol 3-Kinase/metabolism* ; 3T3 Cells ; Animal ; Enzyme Activation ; Fibroblasts/metabolism* ; Human ; Immunoblotting ; Insulin/pharmacology* ; Mice ; Phosphoproteins/metabolism ; Phosphorylation ; Receptor, Insulin/metabolism ; Time Factors