罗格列酮和血清对猪前脂肪细胞诱导分化过程中PPARα和PPARγ基因表达的影响

[目的]探讨罗格列酮和血清对猪前脂肪细胞诱导分化过程中PPARα和PPARγ基因表达的影响。[方法]利用胶原酶消化法分离了猪皮下前脂肪细胞,采用3种不同分化培养液对猪前脂肪细胞进行了诱导分化,借助油红O染色提取法比较了不同分化培养液对分化过程中细胞内脂肪含量变化的影响,并运用实时定量RT-PCR方法检测了不同分化培养液细胞分化过程中PPARα和PPARγ基因表达的变化趋势。[结果]细胞内脂肪聚积以含罗格列酮的MⅡ最快,不含罗格列酮的MⅠ最慢。罗格列酮可极显著上调PPARγ基因的表达（P〈0.01）,而对PPARα基因的表达存在一定的抑制作用,但不显著。血清对PPARγ基因的表达有极显著的上调作用（P〈0.01）,而对PPARα基因的表达有极显著下调作用（P〈0.01）。[结论]罗格列酮可极大地促进PPARγ基因的表达,继而增进细胞内脂肪沉积;血清中可能存在PPARγ基因的激活剂,同时存在PPARα基因的抑制因子。     

Effects of PPARγ agonist on calpain expression in model of acute experimental autoimmune encephalomyelitis

AIM: To explore the effects of peroxisome proliferator-activated receptor γ （PPARγ） agonist on calcium-activated neutral proteinase, calpain, expression in the brain of rats with acute experimental autoimmune encephalomyelitis (EAE). METHODS: EAE model was established in rats by inoculating the homogenate contained spinal cord of guinea pig and complete Freunds adjuvant. Respectively, the PPARγ agonist rosiglitazone and non-steroid anti-inflammatory drug (NSAID) ibuprofen were used to treat the EAE rats. Outcome measures (Kohs scale) were applied at baseline and after treatment to assess the improvement of clinical symptoms. Calpain expression levels were detected by RT-PCR and Western blotting. RESULTS: All the groups showed significant improvements of scales scores after treatment with rosiglitazone and ibuprofen. No significant difference of the expression of calpain mRNA was found among EAE group, rosiglitazone and ibuprofen groups (P>0.05), but the expression of calpain reduced markedly in rosiglitazone and ibuprofen groups compared with that in EAE group (P<0.05). CONCLUSION: Rosiglitazone and ibuprofen inhibit the expression of calpain and improve the clinical symptoms of EAE rats. PPARγ agonist plays a neuroprotective role in EAE rats.     

Effect of peroxisome proliferator-activated receptor γ agonist rosiglitazone on intestinal injury in rats undergoing orthotopic autologous liver transplantation by inhibiting inflammatory response

AIM: To investigate the effect of rosiglitazone, a peroxisome proliferators-activated receptor γ(PPARγ) agonist, on the expression of PPARγ, the activation of NF-κB and intestine injury in the rats undergoing orthotopic autologous liver transplantation(OALT).METHODS: Sprague-Dawley male rats were randomly divided into 4 groups:control group, sham group, OALT group and rosiglitazone(0.3 mg/kg, iv) pretreatment(ROS+OALT) group. The OALT model was established, and the intestinal tissues were collected 8 h after the liver reperfusion. The intestinal tissue sections were stained to visualize the damage. The expression of PPARγ and NF-κB in the tissues, the concentrations of diamine oxidase(DAO) and fatty acid-binding protein 2(FABP2) in the serum and the concentration of TNF-α and IL-6 in the tissues were measured.RESULTS: Compared with sham group, the intestinal mucosa of the rats showed obvious pathological injury after liver reperfusion in OALT group and ROS group, the Chiu,s scores of intestinal mucosa was significantly higher, and the serum concentrations of DAO and FABP2 increased(P<0.05). After rosiglitazone pretreatment, the injury of intestinal mucosa of the rats was alleviated, the Chiu,s scores was lower and the serum concentrations of DAO and FABP2 decreased(P<0.05), the PPARγ expression was obviously up-regulated in the intestinal tissues, the nuclear translocation of NF-κB was reduced and the concentrations of IL-6 and TNF-α were decreased.CONCLUSION: During perioperative period of OALT in rats, the inflammatory responses are obvious. Furthermore, obvious intestinal injury occurs. PPARγ agonist rosiglitazone obviously up-regulates PPARγ expression and inhibits the inflammation in the intestines, thus protecting against intestinal injury in rats undergoing OALT.     

罗格列酮和血清对猪前脂肪细胞诱导分化过程中PPARα和PPARγ基因表达的影响

[目的]探讨罗格列酮和血清对猪前脂肪细胞诱导分化过程中PPARα和PPARγ基因表达的影响。[方法]利用胶原酶消化法分离了猪皮下前脂肪细胞,采用3种不同分化培养液对猪前脂肪细胞进行了诱导分化,借助油红O染色提取法比较了不同分化培养液对分化过程中细胞内脂肪含量变化的影响,并运用实时定量RT-PCR方法检测了不同分化培养液细胞分化过程中PPARα和PPARγ基因表达的变化趋势。[结果]细胞内脂肪聚积以含罗格列酮的MⅡ最快,不含罗格列酮的MⅠ最慢。罗格列酮可极显著上调PPARγ基因的表达（P〈0.01）,而对PPARα基因的表达存在一定的抑制作用,但不显著。血清对PPARγ基因的表达有极显著的上调作用（P〈0.01）,而对PPARα基因的表达有极显著下调作用（P〈0.01）。[结论]罗格列酮可极大地促进PPARγ基因的表达,继而增进细胞内脂肪沉积;血清中可能存在PPARγ基因的激活剂,同时存在PPARα基因的抑制因子。     

Effects of rosiglitazone on expressions of peroxisome proliferator-activated receptor gamma and TGF-β1 in rats with adriamycin nephrosis

AIM: To investigate the expression of renal peroxisome proliferator-activated receptor gamma (PPARγ) in rats with adrimycine nephrosis (ADR), and the effect of rosiglitazone on the activation of NF-κB p65 in renal tissue rats with ADR. METHODS: The rats were randomly assigned to following groups: control (CTR) group, adrimycine nephrosis (ADR) group, and ADR treated with rosiglitazone (5 mg·kg^-1·d^-1) group（RGL）. The levels of urinary protein, albumin, total cholesterol, triglyceride and renal function change in rats were measured after 12 weeks. The nuclear-translocation of cortical NF-κB p65 was detected by immunohistochemistry. The activity of cortical NF-κB p65 was measured by sandwich ELISA. The mRNA levels of cortical PPARγ and TGF-β₁ were detected by RT-PCR. The protein expressions of PPARγ and TGF-β₁ in the rat kidney tissues were detected by Western blotting. RESULTS: As compared to ADR group, the urinary protein excretion in RGL treatment group was decreased and the serum albumin levels were increased, but the serum total cholesterol and triglyceride were decreased and the renal pathological lesion was ameliorated. The activity of NF-κB p65 and the expressions of TGF-β₁ mRNA and protein were significantly decreased in rosiglitazone group, while the expression of PPARγ mRNA and protein was increased in RGL group (P<0.01). The correlation analysis was manifested: in ADR and RGL group, a negative correlation between the activity of NF-κB p65 and the expression of PPARγ in renal tissue (r=-0.8305, P<0.01) was observed. There was a negative correlation between the expression of TGF-β₁ and PPARγ in renal tissues (r=－0.7938, P<0.01). CONCLUSION: The expression of renal cortical PPARγ is up-regulated in rats with adrimycine nephrosis by rosiglitazone. Rosiglitazone inhibits the activation of renal cortical NF-κB p65 in part, so it inhibits the gene expression of renal TGF-β₁ and relieves the renal pathological lesion.     

Role of Wnt pathway in Aβ deposition in hippocampus of insulin resistant rats before and after treated with rosiglitazone

AIM: To investigate the relationship between classical Wnt pathway with β-amyloid peptide(Aβ) deposition in hippocampus of insulin resistance(IR) rat model and to observe the above-mentioned proteins and the correlation with peroxisome proliferator-activated receptor γ(PPARγ) by treating the IR rats with rosiglitazone.METHODS: The rat models of IR and TZD were made. The plasma insulin and the plasma glucose levels were tested by RIA and glucose-oxidase methods, respectively. The indexes of insulin resistance were calculated by HOMA-IR. The proteins of Aβ, Wnt3a, β-catenin and PPARγ were analyzed by Western blotting.RESULTS: The plasma insulin in IR group was significantly higher than that in control group. Insulin resistance, which was calculated by HOMA-IR, was significantly higher in IR group than that in control group. The levels of Aβ and β-catenin in IR group were higher than those in control group, while the levels of Wnt3a and PPARγ were decreased. After treatment with rosiglitazone, Aβ was reduced but Wnt3a, β-catenin and PPARγ were increased.CONCLUSION: In hippocampus of IR rats, Aβ is deposited and the levels of Wnt3a and Wnt are reduced. Rosiglitazone, as a PPARγ agonist, can upregulate the activity of Wnt pathway and reduce Aβ deposition in rat hippocampus.     

Effect of rosiglitazone on expressions of insulin receptor substrate-1 and glucose transporter 4 in skeletal muscle of type 2 diabetic rats with hyperlipemia

AIM: To investigate the effect of rosiglitazone on the expressions of insulin receptor substrate-1 (IRS-1) and glucose transporter 4 (GLUT4) in skeletal muscles of type 2 diabetic rats with hyperlipemia, and to explore the different pharmacological mechanism. METHODS: The model of type 2 diabetic rats with hyperlipemia was established by injecting low dosage of streptozotocin (STZ) and feeding with high fat diet. Then the diabetic rats were divided into two groups: untreated diabetic group and rosiglitazone-intervened diabetic group. The course of treatment lasted for 4 weeks. The expressions of IRS-1 and the GLUT4 proteins in the cell membrane of isolated rats skeletal muscles were detected by Western blotting. RESULTS: The fasting blood glucose, insulin and triglyceride contents in rosiglitazone-intervened diabetic group were lower than those in untreated diabetic group, but they were still higher than those in control group. The result of Western blotting showed that the expression of GLUT4 protein in rosiglitazone-intervened diabetic group was increased compared with untreated diabetic group, but its level was still lower than that in control group. The protein expression and tyrosine phosphorylation of IRS-1 in rosiglitazone-intervened diabetic group were significantly higher than those in untreated diabetic group and their levels were lower than those in control group. CONCLUSION: The effect of rosiglitazone on GLUT4 protein may link to its ability to induce the protein expression and tyrosine phosphorylation of IRS-1 in skeletal muscles in type 2 diabetic rats.