人参皂苷Rg1对梗阻性肾病大鼠肾脏Klotho表达及肾小管上皮细胞凋亡的影响

目的:观察人参皂苷Rg1(ginsenoside rg1,G-Rg1)对单侧输尿管梗阻(unilateral ureteral obstruction,UUO)大鼠肾脏Klotho表达及肾小管上皮细胞(renal tubular epithelial cell,RTC)凋亡的影响。方法:24只清洁级SD大鼠随机分为三组:对照组、模型组、治疗组;模型组大鼠采用UUO的方法建立肾间质纤维化(renal interstitial fibrosis,RIF)模型,治疗组在UUO的基础上,给予G-Rg1腹腔注射,其余大鼠给予腹腔注射等剂量生理盐水。2周后检测各组大鼠的肾功能,HE及Masson染色观察肾脏病理改变;TUNEL检测RTC凋亡情况,RT-PCR及Western blot检测肾组织Klotho表达变化,Western Blot检测凋亡相关蛋白Bcl-2、Bax的表达情况。结果:与对照组比较,模型组大鼠血清肌酐、尿素氮明显上升,肾脏病理损害加重,RTC凋亡增加;同时模型组肾组织Klotho mRNA及蛋白的表达均减少,伴随凋亡蛋白Bax表达增多及凋亡抑制蛋白Bcl-2表达减少;与模型组比较,治疗组大鼠肾功能好转,肾脏病理损害缓解,RTC凋亡减轻;同时肾组织Klotho mRNA及蛋白表达水平升高,伴随凋亡蛋白Bax表达减少及凋亡抑制蛋白Bcl-2表达增多。结论:G-Rg1可以上调UUO大鼠肾脏Klotho的表达,进而调节凋亡相关蛋白Bax及Bcl-2的表达水平,从而发挥抑制UUO模型中RTC凋亡的作用。     

甲基强的松龙对重症急性胰腺炎大鼠脑组织神经细胞凋亡的影响

目的 探讨甲基强的松龙对重症急性胰腺炎大鼠脑组织神经细胞凋亡的影响.方法 将36只SD大鼠分为3组,假手术组、重症急性胰腺炎组、甲基强的松龙组,每组12只.逆行胰胆管注射5%牛磺脱氧胆酸钠建立重症急性胰腺炎模型.观察各组血清淀粉酶、IL-6、TNF-α水平、腹水量和胰腺组织的病理学改变.RT-PCR法分析脑组织Bcl-2、Bax mRNA的表达水平,TUNEL法检测神经细胞凋亡.结果 重症急性胰腺炎组血清IL-6、TNF-α升高,腩组织Bcl-2 mRNA表达减少,Bax mRNA表达上调,Bcl-2/Bax比值降低,脑组织神经细胞凋亡增加;甲基强的松龙组血清IL-6、TNF-α表达明显下降,脑组织Bcl-2 mRNA表达变化不明显,但Bax mRNA表达下调明显,Bcl-2/Bax比值升高,脑组织神经细胞凋亡显著减少.结论 重症急性胰腺炎时脑组织神经细胞凋亡可能是胰性脑病的发病机制之一;甲基强的松龙可抑制细胞因子的释放,促进脑组织Bcl-2和Bax基因表达的平衡,降低脑组织神经细胞凋亡指数,使脑组织损伤得以改善.     

阿魏酸钠抑制缺血性急性肾衰竭肾小管上皮细胞凋亡

目的：探讨阿魏酸钠对缺血性急性肾衰竭大鼠肾脏小管上皮细胞凋亡的影响及机制。方法：将雄性SD大鼠随机分为假手术组、缺血再灌注组、阿魏酸钠冶疗组、SOD冶疗对照组。观察肾组织病理改变；免疫组化、RT—PCR检测Bax，Bcl-2的表达；采用原位DNAg-断末端标记法（TUNEL）检测肾组织细胞凋亡。结果：大鼠肾脏缺血45min再灌注24h，大鼠肾功能损害明显，肾脏组织病理学改变明显，肾小管上皮细胞凋亡明显，肾组织Bax蛋白、mRNA的表达上调，Bcl-2蛋白、mRNA的表达下调。应用阿魏酸钠干预后。改变与上述相反。结论：在缺血性急性肾衰竭中，阿魏酸钠减轻肾脏缺血再灌注桶伤．减轻肾脏细胞凋亡．缓解肾功能桶害．奠作用至少部分通过调控凋亡相关基因Bcl-2家族基因的表达。     

FK506对肝脏保存再灌注中Bcl-2 mRNA、Bax mRNA表达及肝细胞凋亡的影响

目的探讨肝脏保存再灌注中Bcl-2 mRNA、Bax mRNA表达,肝细胞凋亡以及FK506的作用.方法建立离体大鼠肝脏保存再灌注模型,采用逆转录-多聚酶链反应(RT-PCR)和细胞凋亡原位末端标记技术(TUNEL),分别检测肝脏保存0、8、16、24、32 h组Bcl-2 mRNA、Bax mRNA表达,肝细胞凋亡以及FK506对上述指标的影响.结果 FK506保存组16、24、32 h Bcl-2 mRNA表达明显高于对照组(P<0.05); Bax mRNA表达明显低于对照组(P<0.05);FK506保存组肝细胞凋亡指数明显低于对照组(P<0.05).结论 FK506能使肝脏保存再灌注中Bcl-2 mRNA表达增强,Bax mRNA表达减低,肝细胞凋亡减少.FK506对肝脏保存再灌注损伤具有防治作用.     

邻苯二甲酸二丁酯孕期暴露导致性发育期子代大鼠睾丸细胞凋亡和空泡化

目的:探讨邻苯二甲酸二丁酯(DBP)孕期暴露对性发育期子代大鼠睾丸细胞凋亡的影响。方法:受孕SD大鼠10只,随机分为空白对照组和DBP染毒组,妊娠12~19 d,空白对照组和DBP染毒组分别给予橄榄油1 ml/d和DBP 500 mg/(kg·d)灌胃,于性发育期(PND45)取出睾丸标本,透射电镜观察睾丸细胞结构,HE染色观察各级生精细胞发育情况,TUNEL法检测睾丸细胞凋亡情况,免疫组化和Western印迹观察凋亡调控蛋白Bcl-2、Bcl-XL、Bax和p53的表达。结果:电镜观察见DBP染毒后性发育期子代大鼠睾丸细胞凋亡增加和细胞空泡化,HE染色见各级生精细胞明显减少,TUNEL检测结果显示DBP染毒组细胞凋亡指数明显高于空白对照组(12.00±5.22 vs 3.17±1.47,P0.01),免疫组化和Western印迹提示DBP染毒组促凋亡蛋白Bax和p53的表达较空白对照组显著升高(P0.05)。结论:DBP孕期染毒导致性发育期雄性子代大鼠睾丸生殖细胞和支持细胞凋亡增加及细胞空泡化,促凋亡蛋白Bax和p53的表达明显增高。     

党参皂甙减轻大鼠移植肾缺血再灌注损伤中细胞凋亡的作用及其机制

目的 探讨党参提取物皂甙减轻移植肾缺血再灌注损伤中细胞凋亡的作用及其机制.方法 将雌、雄各半SD大鼠随机分成三组,每组20只,即假手术组、缺血再灌注组和皂甙干预组.假手术组不进行肾移植,仅切除右肾,游离左肾动静脉,暴露左肾1 h后关闭腹腔.缺血再灌注组和皂甙干预组建立大鼠移植肾缺血再灌注损伤模型.皂甙干预组分别于肾移植前48、24和0.5 h经腹腔注入皂甙溶液(每千克体重80 mg).移植肾再灌注后24 h,取大鼠外周血和移植肾组织待测.检测各组血尿素氮(BUN)和肌酐(Cr)水平;采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记(TUNEL)法检测各组肾组织原位细胞凋亡指数(AI);采用逆转录聚合酶链反应(RT-PCR)检测与细胞凋亡有关的基因Bcl-2和Bax mRNA在各组肾组织中的相对表达量.结果 与假手术组相比,缺血再灌注组和皂甙干预组血BUN和Cr水平都显著升高(P＜0.05);移植肾细胞凋亡指数也显著增高(P＜0.05);移植肾组织中Bcl-2 mRNA表达显著降低,Bax mRNA表达显著增高(P＜0.05).与缺血再灌注组比较,皂甙干预组血BUN和Cr值明显下降(P＜0.05);移植肾细胞凋亡指数明显下降(P＜0.05);移植肾组织中Bcl-2 mRNA表达显著增加,Bax mRNA表达明显下降(P＜0.05).结论 党参皂甙在移植肾缺血再灌注损伤中能显著减轻细胞凋亡.其机制可能是通过对Bcl-2基因表达的上调和对Bax基因表达的下调,从而抑制细胞的凋亡.     

复方丹参注射液对体外循环后大鼠肺组织Bcl-2和Bax表达的影响

目的探讨复方丹参注射液对体外循环（CPB）后大鼠肺组织凋亡调控基因Bcl-2和Bax表达的影响。方法成年健康雄性SD大鼠24只,年龄12～16周龄,体重400～450 g,随机分为3组（n=8）：对照组、CPB组和丹参组。对照组行假手术,CPB组和丹参组建立体外循环,丹参组在停机前5 min经储血器加入复方丹参注射液1 ml/kg。CPB结束后60 min取肺组织提取总RNA,用RT-PCR方法测定凋亡调控基因Bcl-2、Bax的mRNA表达。取肺组织用多聚甲醛固定,制作石蜡切片,用免疫组织化学方法测定肺组织中Bcl-2、Bax的蛋白表达。结果与对照组相比,CPB组和丹参组肺组织Bcl-2和Bax的mRNA和蛋白表达均增加（P＜0．05或0．01）,CPB组Bax/Bcl-2比值升高（P＜0．05）。与CPB组相比,丹参组肺组织Bax的mRNA表达及Bax/Bcl-2比值均降低（P＜0．05）,肺组织Bcl-2蛋白表达增高,Bax蛋白表达降低（P＜0．01）。结论体外循环可上调凋亡调控基因的表达,复方丹参注射液能下调促凋亡基因Bax的表达,抑制大鼠肺组织的细胞凋亡因而可减轻肺损伤。     

反义p53对创伤后神经元的保护作用

目的 观察p53反义寡核苷酸对创伤后迟发性神经元死亡的防治效果。方法在自由落体打击大鼠弥漫性脑创伤模型中,转染反义寡核苷酸药物,以大鼠神经功能行为评分及Tunel法检测鼠脑皮层神经元DNA损伤情况作为疗效评价指标;用原位杂交、免疫组化法检测p53 mRNA与蛋白质的表达水平。结果大鼠打击后,神经功能行为评分下降,皮层打击区伤后1周内出现神经元凋亡现象。脑创伤后2～4h p53 mRNA及蛋白表达增加。p53反义寡核苷酸转染后的大鼠,神经功能评分明显改善;神经元凋亡数量明显减少;p53 mRNA及蛋白表达减少。结论细胞凋亡在创伤性脑损伤中起重要作用,对创伤后神经功能的缺损有重要影响;反义p53抑制脑创伤后细胞凋亡的发生可能成为治疗创伤性脑损伤后迟发性神经元死亡的新途径。     

藕节对糖尿病肾病大鼠肾组织JAK2/STAT3及凋亡因子表达的影响

也页目的：探讨藕节对糖尿病肾病大鼠肾组织p-JAK2、p-STAT3及凋亡因子Bcl-2、Bax表达的影响。方法：健康雄性SD大鼠60只,随机选取10只为正常组（ N组）,其余采用单次腹腔注射链尿佐菌素（ STZ,45 mg/kg）制作DN模型,造模成功后随机分为糖尿病肾病组（DN）、藕节小剂量组（RL,1.5 g·kg-1·d-1）、中剂量组（RM,3.0 g·kg-1·d-1）、大剂量组（RH,6.0 g·kg-1·d-1）及氯沙坦钾组（LP,30 mg·kg-1·d-1）,均采用灌胃给药,N组和DN组给予等量蒸馏水。12周后检测大鼠生化指标;HE、Masson染色及电镜观察肾脏病理改变;免疫组化法测定p-JAK2、p-STAT3、Bcl-2及Bax在肾组织表达情况;原位末端标记法（ TUNEL）检测肾组织细胞凋亡情况。结果：实验12周末,与N组比较,DN组大鼠肾小球肥大、系膜基质增多、细胞凋亡明显,BUN、Scr、24 h尿蛋白定量明显升高（P〈0.05）,肾组织Bax、p-JAK2、p-STAT3表达明显上调,Bcl-2表达下调（P〈0.05）;与DN组比较,藕节中、高剂量组肾脏病理改变减轻、细胞凋亡减少,24 h尿蛋白定量较DN组明显降低（P〈0.05）,但降尿蛋白作用弱于氯沙坦钾组,同时肾组织Bax、p-JAK2、p-STAT3表达下调,Bcl-2表达上调（P〈0.05）。结论：藕节可能通过上调Bcl-2在肾组织的表达,下调Bax、p-JAK2、p-STAT3的表达,从而减少尿蛋白,延缓DN进展。     

Bcl-2/Bax及Caspase-3在心肌缺血再灌注引起的急性肺损伤中的表达及作用

目的 探讨Bcl-2/Bax及Caspase-3在心肌缺血再灌注及后处理对大鼠肺损伤的表达及作用.方法 雄性SD大鼠30只随机分为3组,每组10只,假手术组（S）、心肌缺血/再灌注组（IR）、缺血后处理组（IPost）.结扎左冠状动脉前降支制备心肌缺血/再灌注模型,后处理组于再灌注前1 min内,连续3个循环灌注10s,缺血10s,再灌注120 min后快速取肺.SP法测定肺组织内Bcl-2/Bax及Caspase-3.TUNEL法检测细胞凋亡.结果 与S组相比较,IR组,IPost组,Bax,Caspase-3,Bcl-2表达减少（P＜0.01）,细胞凋亡增多;与IR组相比较,IPost组,Bax,Caspase-3,细胞凋亡（TUNEL）表达减少,Bcl-2表达增多（P＜0.01）,细胞凋亡减少.结论 缺血后处理可以诱导Bcl-2表达增强,Bax及Caspase-3表达降低,从而减轻肺损伤.     

Expression of transforming growth factor-β type II receptor mRNA in embryonic and adult rat kidney

Summary: The transforming growth factor-β (TGF-β) family of growth factors regulates cell proliferation, differentiation, extracellular matrix synthesis and angiogenesis in many developing tissues. Transforming growth factor-β1 was recently shown to affect the branching of ureteric epithelium and nephron formation in cultured rat metanephroi. As the TGF-β type II receptor is specific for the TGF-β family, the present study used in situ hybridization to localize mRNA for this receptor in metanephroi from Sprague-Dawley rat embryos. Transforming growth factor-β type II receptor mRNA was located in ureteric duct epithelium, undifferentiated mesenchymal cells in the nephrogenic zone, vesicles, comma-shaped bodies and S-shaped bodies. In some S-shaped bodies, TGF-β type II receptor mRNA was not expressed in the lower limb, which subsequently forms the renal corpuscle. Expression was not observed in capillary loop stage glomeruli and maturing glomeruli, or in proximal tubules and interstitial cells. In adult rat kidney, TGF-β type II receptor mRNA was expressed in cortical collecting ducts and distal tubules but not in glomeruli or proximal tubules. These findings demonstrate that the prominent expression of TGF-β type II receptor mRNA decreases as glomeruli and tubules develop. Expression then remains undetectable in adult glomeruli and proximal tubules. the developmentally-regulated expression of this receptor suggests a key role in glomerular and nephron development.     

Dynamic p53 protein expression and phosphorylation in the kidneys of rats that experienced intrauterine growth restriction

Abstract

Aim: This study investigated the mechanisms involved in intrauterine growth restriction (IUGR). Methods: The IUGR model was established by feeding pregnant SD rats a low-protein diet. Protein expression and phosphorylation were detected using Western blot and/or immunohistochemistry. Cell apoptosis was detected by TUNEL staining. The MDM2 mRNA expression was measured by real-time PCR. Results: Pups from the IUGR group had significantly lower body (7th day, 2 months) and kidney weights (1st day, 7th day, 2 months) compared to pups from the control group (p?<?0.01). The glomeruli number in IUGR pups was significantly less than that in the control pups at 2 and 3 months after birth (p?<?0.01). p53 protein level and p53 phosphorylation at Ser¹⁵ were time-dependently decreased in the kidney at 1st day, 7th day, 21st day, 2 months and 3 months, but their levels in the kidney of the IUGR pups was significantly higher than that in control pups at each time point (p?<?0.05, p?<?0.01, or p?<?0.001). Significantly more positive p21 staining was observed in IUGR pups than in control pups at each time point. Real-time PCR of MDM2 mRNA expression showed no significant difference between IUGR and control pups (p?>?0.05). Significant apoptosis was observed in the kidneys of IUGR pups compared to control pups. Conclusion: Malnutrition-induced IUGR may be associated with the activation of p53–p21 signaling in the kidney.     

Intranephron distribution and regulation of endothelin-converting enzyme-1 in cyclosporin A-induced acute renal failure in rats

Endothelin-1 (ET-1) is thought to play a significant role in acute renal failure induced by cyclosporin A (CsA). The cDNA sequence encoding endothelin-converting enzyme-1 (ECE-1), which produces the active form of ET-1 from big ET-1, was recently reported. To elicit the role of ECE-1 in the glomerular and tubular dysfunction induced by CsA, the effects of CsA on mRNA and protein expression of ECE-1 in rat kidney and on mRNA expression of prepro-ET-1 and ET A- and B-type receptors in glomeruli were studied. ECE-1 mRNA was detected in glomeruli and in whole nephron segments. ECE-1 mRNA expression was downregulated in all nephron segments at 24 h after CsA injection. Protein levels were also downregulated in glomeruli and in the outer and inner medulla. CsA rapidly increased prepro-ET-1 mRNA expression in glomeruli at 30 to 60 min after injection; this rapid increase was followed by an increase in plasma ET-1 levels. These increases were followed by decreased expression of ECE-1, ET A-type receptor, and ET B-type receptor mRNA at 6 h after injection, and serum creatinine levels were increased at 24 h after CsA injection. It is suggested that downregulation of glomerular and tubular ECE-1 expression may be caused by increased ET-1 synthesis in CsA-induced acute renal failure.     

Severe intraglomerular detachment of podocytes in a Gitelman syndrome patient

We report the case of a 38-year-old woman diagnosed with Gitelman syndrome. A kidney biopsy showed abundant floating cells in the Bowman's space of the mildly cystic glomeruli, moderate tubulointerstitial changes and apparent intimal thickening of small arteries. These floating cells were immunohistologically identified as podocytes, by the expression of podocalyxin, vimentin, Wilms' tumor 1, synaptopodin and nephrin with positivities of 100%, 88.4%, 80.4%, 74.7% and 22.6%, respectively. In these phenotypes, nephrin expression was notably decreased in both detached and capillary-attached podocytes in comparison with normal control podocytes. Immunostaining of both detached and capillary-attached podocytes for Bax, Bcl-2, desmin, fibroblast-specific protein-1, α-smooth muscle actin and Ki-67 was negative, as were TUNEL assays. These results suggest that apoptosis and epithelial-mesenchymal transition were not the main cause of podocyte detachment in this patient. In addition, levels of urinary podocalyxin were not elevated, suggesting the detached podocytes were not excreted in the urine. To the best of our knowledge, this is the first report of severe intraglomerular non-apoptotic detachment of podocytes in Gitelman syndrome. This podocyte detachment may be associated with nephron obstruction and reduced nephrin expression.     

Apoptotic cell loss following cell proliferation in renal glomeruli of Otsuka Long-Evans Tokushima Fatty rats,a model of human type 2 diabetes

BACKGROUND: The mechanism of glomerular cell loss during the late stage of diabetic nephropathy is unknown. METHODS: We examined cell population, proliferation, apoptosis, and immunohistochemical expression of apoptosis-related proteins, Bcl-2 and Bax, in renal glomeruli of the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, an animal model of human type 2 diabetes. 10-, 30-, 50-, and 70-week-old rats were used (n = 5-8). Control was the Long-Evans Tokushima Otsuka (LETO) rat. RESULTS: The cell population in renal glomeruli of OLETF rats progressively increased with age, but decreased at 70 weeks old. High cell proliferative activity based on proliferating cell nuclear antigen (PCNA) expression was limited during the early stage, whereas by in situ nick end-labeling (TUNEL), Taq polymerase based in situ ligation, and electron microscopy, apoptosis was detected during the late stage (50 and 70 weeks old). Augmented expression of Bax, but not of Bcl-2, was evident in glomeruli of OLETF rats during the late stage, which contributed to an increased Bax/Bcl-2 ratio. CONCLUSION: It appears that high cell proliferative activity and the subsequent cell loss via apoptosis counterbalance each other and determine glomerular cell population of OLETF rats. Augmented Bax expression may be one of the important regulators of this apoptosis.     

Immunolocalization of fibroblast growth factor-1 and -2 in the embryonic rat kidney

Summary: Fibroblast growth factors (FGF) regulate cell proliferation, migration, differentiation and angiogenesis during morphogenesis in many different tissues. Recent evidence indicates that exogenous FGF-2 stimulates mesenchymal condensation in cultured rat metanephroi, a crucial epithelial-mesenchymal induction event in the developing nephron. the aim of the present investigation was to determine the in vivo distribution of FGF-1 and FGF-2 in developing rat metanephroi at embryonic days 14, 15, 16, 18 and 20. Avidin-biotin enhanced indirect immunohistochemistry was used to demonstrate that both FGF-1 and FGF-2 were co-localized in metanephroi at all ages studied. High levels of FGF-1 and FGF-2 were present in ureteric bud branches and in developing distal tubules. Fibroblast growth factor-1 and FGF-2 were colocalized in developing nephron elements, from vesicles to S-shaped bodies, and in the mesangium of capillary loop and maturing stage glomeruli. Both growth factors were present in the mesenchyme of the nephrogenic zone and in the interstitium of the developing cortex. However, immunostaining for FGF was not evident in mesenchymal condensates, endothelial cells, medullary interstitial cells, or in the thin undifferentiated epithelium of the immature loop of Henle. These findings indicate that the expression of both FGF-1 and FGF-2 is tightly regulated in the embryonic kidney and suggest a role for these molecules in kidney development.