Peroxisome proliferator-activated receptor γ ligands regulate neural stem cell proliferation and differentiation in vitro and in vivo

Peroxisome proliferator-activated receptor gamma (PPARγ) belongs to a family of ligand-activated nuclear receptors and its ligands are known to control many physiological and pathological situations. Its role in the central nervous system has been under intense analysis during the last years. Here we show a novel function for PPARγ in controlling stem cell expansion in the adult mammalian brain. Adult rats treated with pioglitazone, a specific ligand of PPARγ, had elevated numbers of proliferating progenitor cells in the subventricular zone and the rostral migratory stream. Electron microscopy analysis also showed important changes in the subventricular zone ultrastructure of pioglitazone-treated animals including an increased number of migratory cell chains. These results were further confirmed in vitro. Neurosphere assays revealed significant increases in the number of neurosphere forming cells from pioglitazone- and rosiglitazone (two specific ligands of PPARγ receptor)-treated cultures that exhibited enhanced capacity for cell migration and differentiation. The effects of pioglitazone were blocked by the PPARγ receptor antagonists GW9662 and T0070907, suggesting that its effects are mediated by a mechanism dependent on PPARγ activation. These results indicate for the first time that activation of PPARγ receptor directly regulates proliferation, differentiation, and migration of neural stem cells in vivo.     

吡格列酮对非乙醇性脂肪肝大鼠肝脏脂质沉积的影响

目的观察吡格列酮对非乙醇性脂肪肝(NAFLD)大鼠肝脏内质网应激(ERS)的影响,为其在肝脏脂质代谢中的作用提供理论依据。方法 30只Sprague-Dawley大鼠随机分为正常对照组、生理盐水组和吡格列酮组,每组10只。生理盐水组和吡格列酮组大鼠用高脂饮食饲养12周成功建立NAFLD模型。吡格列酮组大鼠用吡格列酮治疗12周,生理盐水组大鼠给予生理盐水处理。肝脏病理切片行苏木精-伊红及油红O染色。测量大鼠体质量、肝湿质量,计算肝质量/体质量(肝/体比),检测血清谷氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、总胆固醇(TC)、三酰甘油(TG)及肝脏组织中TC、TG水平;Western blot法检测大鼠肝脏组织ERS相关蛋白葡萄糖调节蛋白78(GRP78)的表达情况。结果生理盐水组大鼠肝细胞均出现不同程度脂肪变性,伴小叶内、汇管区炎性细胞浸润;吡格列酮组多数肝细胞结构恢复正常,细胞质内脂滴空泡明显减少。生理盐水组与正常对照组比较大鼠体质量、肝脏质量、肝/体比、血清及肝脏组织中TC、TG水平、血清AST、ALT水平、肝脏组织GRP78表达水平显著增加,差异有统计学意义(P<0.05);吡格列酮组与生理盐水组比较大鼠体质量、肝脏质量、血清及肝脏组织中TC和TG水平、血清AST和ALT水平、肝脏GRP78水平均显著下降,差异有统计学意义(P<0.05)。结论吡格列酮可能通过改善高脂饮食诱导大鼠肝细胞的ERS水平来纠正脂质代谢异常。     

吡格列酮对糖尿病大鼠肾脏骨桥蛋白表达的影响

 目的 观察吡格列酮对糖尿病大鼠肾组织骨桥蛋白表达的影响。方法 SD大鼠随机分为正常对照组和造模组。链脲佐菌素诱导糖尿病大鼠。造模成功的大鼠随机分为糖尿病组、吡格列酮3,15 mg·kg^-1·d^-1组。8周末测大鼠24 h尿微量白蛋白、血糖,血肌酐。HE染色观察肾组织形态,免疫组织化学法及逆转录-聚合酶链反应法分别测大鼠肾组织骨桥蛋白及骨桥蛋白mRNA的表达。结果 吡格列酮3 mg·kg^-1·d^-1组、吡格列酮15 mg·kg^-1·d^-1组血肌酐、微量白蛋白、肾质量/体质量较糖尿病组明显下降（P<0.05）。与糖尿病组比较,吡格列酮15 mg·kg^-1·d^-1组血糖明显降低（P<0.05）,吡格列酮3 mg·kg^-1·d^-1组血糖无明显改善,差异无统计学意义（P>0.05）。糖尿病组肾组织骨桥蛋白及骨桥蛋白mRNA表达水平较正常对照组明显升高（P<0.05）。吡格列酮3,15 mg·kg^-1·d^-1组肾组织骨桥蛋白、骨桥蛋白mRNA表达水平较糖尿病组均明显下降（P<0.05）。结论 糖尿病大鼠肾组织骨桥蛋白表达增加,提示骨桥蛋白可能参与糖尿病肾脏病变的发病过程。吡格列酮干预可以减少糖尿病大鼠尿微量白蛋白,对肾脏有保护作用。吡格列酮对肾脏的保护作用部分可能与吡格列酮抑制肾脏骨桥蛋白的表达有关。     

过氧化物酶体增殖物激活受体γ激动剂吡格列酮对大鼠创伤性脑损伤的影响

目的 观察PPARγ激动剂吡格列酮对大鼠创伤性脑损伤的神经保护作用.方法 将72只SD大鼠按随机数字表法分为假致伤组、对照组、吡格列酮治疗组,每组24只.采用改良的Feeney法制作脑创伤模型,治疗组采用吡格列酮(10 mg/kg)灌胃,假致伤组和对照组用等量生理盐水灌胃.致伤后在相应时相点行大鼠神经功能评分后,用干湿质量法进行脑组织含水量测定,进行HE、Nissl及TUNEL染色观察脑组织损伤、迟发性神经元死亡及神经细胞凋亡程度.结果 ①在伤后48 h、5 d,治疗组的神经功能评分[分别为(2.12±0.58)、(1.67±0.78)]好于对照组[(2.67±0.65)、(2.25±0.62),P<0.05];②伤后24 h治疗组与对照组脑组织含水量差异无统计学意义[分别为(78.84±1.92)%、(79.21±2.20)%,P>0.05];③伤后48 h,治疗组迟发性神经元死亡(38.59±1.97)%和神经细胞凋亡数(31.67±4.76)明显低于对照组[分别为(51.25±4.01)%、(45.33±4.68),P<0.05].结论 PPARγ激动剂吡格列酮能抑制创伤性脑损伤后的神经细胞凋亡,保护神经元,从而发挥神经保护作用.     

A long‐term comparison of pioglitazone and gliclazide in patients with Type 2 diabetes mellitus: a randomized,double‐blind,parallel‐group comparison trial

Aims This study compared the effects of pioglitazone and gliclazide on metabolic control in drug‐naïve patients with Type 2 diabetes mellitus. Methods A total of 1270 patients with Type 2 diabetes were randomized in a parallel‐group, double‐dummy, double‐blind study. Patients with poorly controlled Type 2 diabetes (HbA_1c 7.5–11%), despite dietary advice, received either pioglitazone up to 45 mg once daily or gliclazide up to 160 mg two times daily. Primary efficacy endpoint was change in HbA_1c from baseline to the end of the study. Secondary efficacy endpoints included change in fasting plasma glucose, fasting plasma insulin and plasma lipids. At selected centres, oral glucose tolerance tests were performed and C‐peptide and pro‐insulin levels were measured. Results Mean HbA_1c values decreased by the same amount in the two treatment groups from baseline to week 52 [pioglitazone: ?1.4%; gliclazide: ?1.4%; (90% CI: ?0.18 to 0.02)]. A significantly greater mean reduction in fasting plasma glucose was observed in the pioglitazone group (2.4 mmol/l) than in the gliclazide group [2.0 mmol/l; treatment difference ?0.4 mmol/l in favour of pioglitazone; P = 0.002; (95% CI: ?0.7 to ?0.1)]. Improvements in high‐density lipoprotein cholesterol (HDL‐C) and total cholesterol/HDL‐C were greater with pioglitazone than with gliclazide (P < 0.001). The frequencies of adverse events were comparable between the two treatment groups, but more hypoglycaemic events were reported for gliclazide, whereas twice as many patients reported oedema with pioglitazone than with gliclazide. Conclusions Pioglitazone monotherapy was equivalent to gliclazide in reducing HbA_1c, with specific differences between treatments in terms of mechanism of action, plasma lipids and adverse events.     

吡格列酮对人脐静脉内皮细胞血凝素样氧化低密度脂蛋白受体1表达的影响

目的探讨氧化型低密度脂蛋白(ox-LDL)作用下,吡格列酮对人脐静脉内皮细胞(HUVECs)血凝素样氧化低密度脂蛋白受体1(LOX-1)表达的影响。方法将培养的第4代HUVECs分5组:空白组(无干预);ox-LDL组(80 mg/L ox-LDL);低浓度组(1μmol/L吡格列酮+80 mg/L ox-LDL);高浓度组(10μmol/L吡格列酮+80 mg/Lox-LDL);对照组(10μmol/L吡格列酮),各组培养24 h后,采用流式细胞仪检测LOX-1的表达,采用RT-PCR检测LOX-1 mRNA的表达。结果与空白组比较,对照组LOX-1及LOX-1 mRNA表达均无明显改变(P0.05),ox-LDL组、低浓度组和高浓度组LOX-1及LOX-1 mRNA表达明显增多(P0.01);与ox-LDL组比较,低浓度组和高浓度组LOX-1及LOX-1 mRNA表达明显降低(P0.01);高浓度组较低浓度组降低更明显(P0.05)。结论吡格列酮能降低ox-LDL刺激下的HUVECs LOX-1及LOX-1 mRNA的表达,提示吡格列酮可能通过干预ox-LDL的病理生理过程起到抗动脉硬化的作用。     

吡格列酮对糖尿病大鼠血清MMP-9水平及其外周血单核细胞中MMP-9表达的影响

目的:观察过氧化物酶体增殖物激活受体γ(PPARγ)配体吡格列酮对糖尿病大鼠血清基质金属蛋白酶9(MMP-9)浓度和外周血单核细胞中MMP-9表达的影响。方法:40只Wistar大鼠随机分为5组,即对照组、糖尿病组和不同剂量5、10、20mg/(kg.d)吡格列酮治疗组,每组8只。给糖尿病组和3个吡格列酮治疗组大鼠腹腔注射链脲霉素制作糖尿病大鼠模型后,各吡格列酮治疗组以不同剂量的吡格列酮灌胃:5、10、20mg/(kg.d),共28d;对照组和糖尿病组以等量生理盐水灌胃。比较治疗前、后的血清MMP-9浓度的变化。分离大鼠外周血单核细胞,用RT-PCR和Westernblot检测MMP-9表达的变化。结果:与对照组比较,吡格列酮降低血清MMP-9的浓度(P0.05),降低外周血单核细胞中MMP-9的表达。结论:吡格列酮可以降低糖尿病大鼠血清MMP-9浓度及外周血单核细胞中MMP-9的表达,提示其在降糖之外还具有心血管保护作用。     

Rosiglitazone and pioglitazone increase fracture risk in women and men with type 2 diabetes

Aim: The objectives of the study were to determine whether thiazolidinedione (TZD) use is associated with an increased risk of fracture in men and women with type 2 diabetes mellitus and to compare the effects of pioglitazone and rosiglitazone. Materials and Methods: A research database of integrated pharmacy and medical claims was analysed using Cox models adjusted for age, gender, chronic obstructive pulmonary disease, asthma, osteoporosis, stroke, prior fracture and chronic disease score. Patients were followed for 540 days. Results: There was a 39% higher [adjusted hazard ratio (HR), 1.39; 95% confidence interval (CI), 1.32–1.46] incidence of fractures in men and women exposed to a TZD (n = 69047; age = 56 ± 5 years; 59% men; 48% rosiglitazone) compared with that in control patients (n = 75352; age = 56 ± 5 years; 51% men). Men treated with a TZD had a higher likelihood of fracture than control patients (adjusted HR rosiglitazone, 1.47; 95% CI, 1.38–1.56; adjusted HR pioglitazone, 1.43; 95% CI, 1.34–1.52). The HRs associated with pioglitazone (adjusted HR, 1.43; 95% CI, 1.34–1.52) and rosiglitazone (adjusted HR, 1.47; 95% CI, 1.38–1.56) were almost identical. TZD use was associated with a higher fracture risk in women aged above and below 50 years and in men aged above 50 years. Conclusions: Our findings add support to the growing literature that TZD treatment is associated with an increased risk of fractures in both men and women, that effects of rosiglitazone and pioglitazone are similar and that fracture risk is increased even in younger women.     

PPARγ agonist pioglitazone reverses memory impairment and biochemical changes in a mouse model of type 2 diabetes

OBJECTIVE Pioglitazone,known as a peroxisome proliferator-activated receptor γ(PPARγ) agonist,is used to treat type 2 diabetes(T2DM).T2DM has been associated with reduced performance on numerous domains of cognitive function.Here,we investigated the effects of pioglitazone on memory impairment in a mouse model with defects in insulin sensitivity and secretion,namely high-fat diet(HFD) streptozotocin(STZ)-induced diabetic mice.METHODS ICR mice were fed an HFD for 4 weeks and then injected with a single low dose of STZ followed by continued HFD feeding for an additional 4 weeks.The diabetic mice were orally administered with pioglitazone(9,18 mg·kg-1) for 4-5 weeks.Y-maze test and Morris water maze test(MWM) were employed for testing learning and memory.Serum glucose,serum insulin,serum triglyceride,brain amyloid peptide-β(Aβ),brain β-site amyloid precursor protein cleaving enzyme(BACE1),brain nuclear factor κB(NF-κB),brain receptor for advanced glycation end products(RAGE) were also tested.RESULTS The STZ/HFD diabetic mice,characterized by hyperglycemia,hyperlipemia and hypoinsulinemia,performed poorly on Y-maze and MWM hence reflecting impairment of learning and memory behavior with increases of Aβ40/Aβ42,BACE1,NF-κB,and RAGE in brain.Treatment of PPARγ agonist,pioglitazone,significantly reversed diabetes-induced impairment of learning and memory behavior,which is involved in decreases of Aβ40/Aβ42 via inhibition of NF-κB,BACE1 and RAGE in brain as well as attenuation of hyperglycemia,hyperlipemia and hypoinsulinemia.CONCLUSION It is concluded that PPARγ agonist pioglitazone may be considered as potential pharmacological agents for the management of cognitive dysfunction in T2DM.     

吡格列酮对糖尿病大鼠氧化应激和肾组织基质积聚的影响

目的研究吡格列酮对链脲佐菌素(STZ)诱导的糖尿病大鼠氧化应激及肾组织细胞外基质蛋白积聚的影响。方法将45只大鼠随机分为3组:正常对照组(NC组),糖尿病对照组(DM组),糖尿病吡格列酮治疗组(DP组)。DP组给予吡格列酮20mg.kg-1.d-1灌胃。8周后观察大鼠肾指数(KI)、尿微量清蛋白(MAU)、肾组织丙二醛(MAD)、过氧化氢酶(CAT)、铜锌超氧化物歧化酶(Cu,Zn-SOD)等,光镜及超微电镜观察肾脏病理形态学改变,免疫组化法观察肾组织Ⅳ型胶原表达。结果 DM组大鼠KI、MAU、肾组织MAD水平显著高于NC组,并出现典型糖尿病肾病(DN)病理学损害,而DP组KI、MAU、MAD水平明显下降,差异有统计学意义(P<0.01);DM组大鼠肾组织CAT、Cu-ZnSOD水平较NC组降低(P<0.01),DP组CAT、Cu-ZnSOD显著上升(P<0.01)。DM组大鼠肾组织Ⅳ型胶原表达明显增多,DP组表达显著降低(P<0.01)。结论吡格列酮可通过抑制氧化应激反应、减轻细胞外基质积聚,对DN起保护作用。