肾组织细胞凋亡在脓毒症诱发小鼠急性肾损伤中的作用

目的 探讨肾组织细胞凋亡在脓毒症诱发小鼠急性肾损伤中的作用.方法 健康清洁级雄性C57BL/6小鼠45只,随机分为3组(n=15),假手术组(S组)、盲肠结扎穿孔术组(CLP组)和半胱氨酸蛋白酶(caspase)-3抑制剂+盲肠结扎穿孔术组(CI组),CLP组于术前30 min时腹部皮下注射caspase-3抑制剂Ac-DEVD-CHO 4μg/g.分别于CLP术后6、12、24 h时取眼球法采集血样,测定血清尿素氮(BUN)和肌酐(Cr)的浓度,然后取肾组织,测定细胞凋亡情况、caspase-3蛋白和caspase-3 mRNA表达水平,光镜下观察肾组织病理学结果.结果 与S组比较,CLP组血清BUN、Cr的浓度及肾组织细胞凋亡率升高,caspase-3 mRNA表达上调(P＜0.05),caspase-3蛋白表达上调;与CLP组比较,CI组血清BUN、Cr的浓度及肾组织细胞凋亡率降低,caspase-3 mRNA表达下调(P＜0.05),caspase-3蛋白表达下调.CI组肾组织病理学损伤程度轻于CLP组.结论 肾组织细胞凋亡是脓毒症诱发小鼠急性肾损伤的机制之一.     

天冬氨酸特异性半胱氨酸蛋白酶活化在喜树碱诱导膀胱癌细胞凋亡中的作用

目的：探讨天冬氨酸特异性半胱氨酸蛋白酶(Caspase)活化,在DNA拓扑异构酶Ⅰ抑制剂喜树碱(CPT)诱导人膀胱癌细胞凋亡中的作用。方法：将体外培养的膀胱癌RT4和MGH细胞用CPT处理,用流式细胞仪检测处理前及处理后24、36、48h等不同时段细胞凋亡的变化,用蛋白免疫印迹方法检测CPT处理后不同时间段caspase-9和caspase-3活性的改变。结果：CPT处理膀胱RT4和MGH细胞后,细胞凋亡率明显上升,且CPT诱导的膀胱癌凋亡呈时间依赖性和剂量依赖性。同时还可以观察到凋亡执行蛋白caspase-9和caspase-3的活化。结论：CPT能够诱导膀胱癌细胞RT4和MGH发生凋亡．其中caspase-9启动的凋亡内源性途径即线粒体途径可能参与了CPT诱导的膀胱癌细胞的凋亡。     

Role of TNF-associated cytokines in renal tubular cell apoptosis induced by hyperoxaluria

Crystal–cell interaction has been reported as one of the most crucial steps in urinary stone formation. Hyperoxaluria-induced apoptotic changes in renal tubular epithelial cells is the end-stage of this interaction. We aimed to evaluate the possible pathways responsible in the induction of apoptosis within the involved cells by assessing the receptoral expression of three different pathways. 16 male Spraque–Dowley rats were divided into two groups: Group 1 (n:8) received only distilled water; Group 2 (n:8) received 0.75 % ethylene glycol (EG) in their daily water to induce hyperoxaluria for 2 weeks. After 24 h urine collection, all animals were euthenized and right kidneys were removed and fixed for immunohistochemical evaluation. Oxalate and creatinine levels (in 24 h-urine) and FAS, tumor necrosis factor (TNF), TNF-related apoptosis-inducing ligand (TRAIL) and TRAIL receptor-2 expressions (in tissue) have been assessed. In addition to TNF (p = 0.0007) expression; both FAS (p = 0.0129 ) and FASL (p = 0.032) expressions significantly increased in animals treated with EG. The expressions of TRAIL (p = 0.49) and TRAIL-R2 (p = 0.34) receptors did not change statistically after hyperoxaluria induction. Although a positive correlation with cytokine expression density and 24 h-urinary oxalate expression (mg oxalate/mg creatinine) has been assessed with TNF (p = 0.04, r = 0.82), FAS (p = 0.05, r = 0.80), FAS-L (p = 0.04, r = 0.82); no correlation could be demonstrated between TRAIL and TRAIL R2 expressions. Our results indicate that apoptosis induced by oxalate is possibly mediated via TNF and FAS pathways. However, TRAIL and TRAIL-R2 seemed to have no function in the cascade. Correlation with urinary oxalate levels did further strengthen the findings.     

Role of caspases on cell death, inflammation, and cell cycle in glycerol-induced acute renal failure

Caspases are the main executioners of apoptosis as well as interleukin (IL)-1beta and IL-18 conversion to active forms. They are activated after acute kidney injuries. In this study, we evaluated the importance of the caspase family in the pathogenesis and recovery of glycerol-induced acute renal failure in rats (Gly-ARF). Rats were treated with pan-caspase or selective caspase 1 and 3 inhibitors at the moment we injected glycerol. Renal function, renal histology (HE), transferase-mediated deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling staining for apoptosis, leukocytes infiltration (immunohistochemistry), renal expression of IL-1beta and IL-18 (immunohistochemistry and Western blot), tubular regeneration (5-bromo-2'-deoxyuridine (BrdU) incorporation), and P27(Kip) expression (Western blot) were evaluated at appropriate times. All inhibitors reduced the renal function impairment. Pan-caspase and caspase-3 inhibitors reduced cellular death (necrosis and apoptosis) 24 h after Gly-ARF. All caspases inhibitors reduced macrophages infiltration. The expression of total IL-1beta was enhanced in Gly-ARF, but the active IL-1beta and IL-18 forms were abolished in pan-caspase treated rats. Caspase-1 inhibitor attenuated Gly-ARF but not tubular injury suggesting glomerular hemodynamic improvement. There was striking regenerative response 48 h after Gly-ARF characterized by enhanced BrdU incorporation and reduced expression of p27(Kip). This response was not blunted by caspases inhibition. Our findings demonstrate that caspases participate in important pathogenic mechanisms in Gly-ARF such as inflammation, apoptosis, vasoconstriction, and tubular necrosis. The early inhibition of caspases attenuates these mechanisms and reduces the renal function impairment in Gly-ARF.     

牛磺酸对白蛋白诱导的鼠肾小管细胞凋亡的保护作用

白蛋白诱导肾小管细胞凋亡是蛋白尿导致肾小管间质损害的重要因素之一，因此，探索干预肾小管细胞凋亡的途径非常必要。已有研究发现牛磺酸对细胞损伤具有保护作用。本研究通过评价牛磺酸对白蛋白诱导的肾小管细胞凋亡作用的影响，探讨其信号传导机制。     

Osteosarcoma cell apoptosis induced by selenium.

An essential nutrient selenium has been reported to be a potential cancer preventive and inhibitory agent, although no exact mechanism has yet been proposed. Since little is known about the anti-proliferative effect of selenium on osteosarcoma, this issue was addressed in the present study in vitro using three osteosarcoma cell lines, and in vivo using an osteosarcoma transplantable to nude mice. Selenium inhibited the tumor growth in vitro and morphological changes indicative of apoptosis were demonstrated. Osteosarcomas in nude mice were inhibited in growth by selenium with no cytotoxic change in normal tissues. The findings suggested that selenium may offer a novel therapeutic modality for osteosarcoma.     

Evaluation of apoptosis and cell proliferation in experimentally induced renal cysts

Cell proliferation and apoptosis in renal cysts induced by streptozotocin, alloxan and ferric-nitrilotriacetate were investigated in rats. In the kidneys of all treated animals dilated tubules at the cortico-medullary region, large cysts, glomerular cysts and tubular dilation in the medullary area were found. Both cell proliferation and apoptosis were increased in the epithelium of the non-dilated tubules, in the mesangial and interstitial cells. Cells lining the dilated tubules or cysts demonstrated apoptosis but their proliferating activity was low. By calculating the proliferation–apoptosis ratio we found that alloxan did not change the balance between the two mechanisms. Meanwhile streptozotocin resulted in an increased apoptosis and ferric-nitrilotriacetate in an increased cell proliferation. p53 expression might be responsible for the uncontrolled proliferation in rats treated with ferric-nitrilotriacetate as this oncoprotein was diffusely present in tubular cell nuclei. The observed apoptosis seemed to be independent of bcl-2 oncoprotein expression. We assume that the initial factor in such cystogenesis should be a cellular injury due to direct toxic or to the diabetogenic effect of the drugs. The latter is more likely as all the animals were hyperglycemic and insulin treatment following administration of streptozotocin prevented the morphologic changes. Received: 10 January 1998 / Accepted: 2 June 1998     

异丙酚对急性肺栓塞大鼠肺细胞凋亡的影响

目的 评价异丙酚对急性肺栓塞大鼠肺细胞凋亡的影响.方法 健康雄性SD大鼠40只,体重280～300 g,随机分为5组(n=8):假手术组(S组)、急性肺栓塞组(APTE组)、异丙酚4 mg·kg-1 ·h-1 组(P1组)、异丙酚8 mg·kg-1 ·h- 1组(P2组)和异丙酚16 mg·kg-1 ·h-1 组(P3组).取尾静脉血样0.2 ml,37℃水浴箱内过夜,分割成直径1 mm ,长5 mm的栓子,颈静脉注射混有15个栓子的2 ml生理盐水制备大鼠肺栓塞模型.S组静脉输注生理盐水2 ml/h 4 h;APTE组、P1组、P2组和P3组制备肺栓塞模型,然后APTE组静脉输注5%葡萄糖2 ml/h4 h,P1 组、P2组和P3组分别静脉输注异丙酚4、8、16 mg·kg-1 ·h-1 (用5%葡萄糖稀释至2 m1)4 h.给药结束后,处死大鼠,取肺组织,采用流式细胞仪检测细胞凋亡情况,计算细胞凋亡率,采用RT-PCR法检测caspase-3、Bcl-2、Box、Fas和FasL的mRNA表达水平,采用Western blot法检测caspase-3、Bcl-2、Bax、Fas和FasL的蛋白表达水平,计算Bcl-2/Bax的mRNA和蛋白表达比值.结果 与S组比较,AVIE组、P1组、P2组和P3 组肺组织细胞凋亡率升高,caspase-3、Bax、Fas、FasL的mRNA和蛋白表达上调,Bcl-2的mRNA和蛋白表达下调,Bcl-2/Bax的mRNA和蛋白表达比值降低(P＜0.05或0.01);与APTE组比较,P1组、P2组和P3 组肺组织细胞凋亡率降低,caspase-3、Bax、Fas、FasL的mRNA和蛋白表达下调,Bcl-2的mRNA和蛋白表达上调,Bcl-2/Bax的mRNA和蛋白表达比值升高(P＜0.05或0.01);P.组、P2组和P3组间肺组织细胞凋亡率、caspase-3、Bcl-2、Bax、Fas、 FasL的mRNA和蛋白表达、Bcl-2/Bax的mRNA和蛋白表达比值差异无统计学意义(P＞0.05).结论 异丙酚可抑制急性肺栓塞大鼠肺细胞凋亡,其机制与下调肺组织caspase-3、Fas和FasL的表达,调节Bcl-2/Bax的平衡有关.     

异丙酚对急性肺栓塞大鼠肺细胞凋亡的影响

Objective To evaluate the effect of propofol on lung cell apoptosis induced by acute pulmonary thromboembolism (APTE) .Methods Forty male SD rats weighing 280-300 g were randomly divided into 5 groups ( n = 8 each) : group Ⅰ sham operation ( group S) ; group ⅡAPTE and 3 propofol groups ( group P1-3). APTE was produced by iv injection of auto-blood clots. Venous blood 0.2 ml was obtained from rat tail vein and placed in a sterile test tube which was kept in water bath at 37 ℃ overnight. The blood clot was cut into thrombi ( diameter 1 mm, length 5 mm) the next day. Fifteen thrombi in 2 ml of normal saline were injected into immediately after iv injection of auto-bloed clots. The animals were killed at the end of 4 h propofol infusion and lung specimens were obtained for determination of lung cell apoptosis rate by flow eytometry and expression of caspase-3, Bax, Bcl-2, Fas, FasL mRNA and protein by RT-PCR and Western blot.The expression of Bcl-2/Bax mRNA and protein was calculated. Results Compared with group S,APTE significantly increased the lung cell apoptosis rate, and expression of caspase-3, Bax, Fas, FasL and decreased the expression of Bcl-2 and Bcl-2/Bax. Propofol infusion significantly attenuated these APTE-induced changes. Conclusion Propofol can inhibit APTE-induced lung cell apoptosis by down-regulating the caspase-3, Fas and FasL expression and regulating the balance between Bcl-2 and Bax expression.     

异丙酚对急性肺栓塞大鼠肺细胞凋亡的影响

Objective To evaluate the effect of propofol on lung cell apoptosis induced by acute pulmonary thromboembolism (APTE) .Methods Forty male SD rats weighing 280-300 g were randomly divided into 5 groups ( n = 8 each) : group Ⅰ sham operation ( group S) ; group ⅡAPTE and 3 propofol groups ( group P1-3). APTE was produced by iv injection of auto-blood clots. Venous blood 0.2 ml was obtained from rat tail vein and placed in a sterile test tube which was kept in water bath at 37 ℃ overnight. The blood clot was cut into thrombi ( diameter 1 mm, length 5 mm) the next day. Fifteen thrombi in 2 ml of normal saline were injected into immediately after iv injection of auto-bloed clots. The animals were killed at the end of 4 h propofol infusion and lung specimens were obtained for determination of lung cell apoptosis rate by flow eytometry and expression of caspase-3, Bax, Bcl-2, Fas, FasL mRNA and protein by RT-PCR and Western blot.The expression of Bcl-2/Bax mRNA and protein was calculated. Results Compared with group S,APTE significantly increased the lung cell apoptosis rate, and expression of caspase-3, Bax, Fas, FasL and decreased the expression of Bcl-2 and Bcl-2/Bax. Propofol infusion significantly attenuated these APTE-induced changes. Conclusion Propofol can inhibit APTE-induced lung cell apoptosis by down-regulating the caspase-3, Fas and FasL expression and regulating the balance between Bcl-2 and Bax expression.     

血红素加氧酶1对白蛋白诱导肾小管上皮细胞凋亡的影响

目的 探讨血红素加氧酶1（HO-1）对白蛋白诱导肾小管上皮细胞凋亡的影响及其可能机制。 方法 体外培养大鼠肾小管上皮细胞（NRK-52E）为正常对照。白蛋白对照组加去脂的小牛血清白蛋白（BSA）30 g/L共同培养。干预组先加钴卟啉（Cobalt protoporphyrin IX,CoPP,血红素加氧酶1诱导剂）5 μmol/L,0.5 h后再加入BSA 30 g/L,作用24 h。四甲基偶氮唑盐（MTT）比色法检测CoPP对BSA抑制NRK-52E细胞增殖的影响。细胞免疫荧光染色检测细胞凋亡率。RT-PCR法检测凋亡相关蛋白Bcl-2、Bax mRNA表达情况。 结果 与正常对照组比较,BSA对细胞增殖具有抑制作用并诱导细胞凋亡,差异有统计学意义（P < 0.05）,而CoPP对BSA引起的细胞毒性作用具有保护作用（P < 0.05）;BSA对照组HO-1 mRNA表达增加（0.44±0.06比0.39±0.05,P < 0.05),差异有统计学意义（P < 0.05）。CoPP预处理后,HO-1 mRNA表达（0.50±0.06）较BSA对照组增加（P < 0.05）。BSA可上调Bax mRNA表达(0.87±0.04比0.67±0.03,P < 0.05）及下调Bcl-2 mRNA的表达（0.25±0.04比0.42±0.02,P < 0.05),当加入CoPP预处理后可抑制上述改变（Bax mRNA：0.75±0.07,Bcl-2 mRNA：0.36±0.03,均P < 0.05）。 结论 BSA可显著增加细胞的凋亡率并直接调控凋亡相关蛋白mRNA的表达,CoPP可抑制上述BSA的作用。HO-1对BSA所致肾小管上皮细胞凋亡具有保护作用,可以抑制细胞凋亡。     

Signaling for the caspases: their role in prostate cell apoptosis

PURPOSE: The caspases are an evolutionary conserved family of cell death proteases. Their activation during apoptosis is an important underlying theme in prostate cancer therapy. We summarize the signaling pathways leading to the recruitment of the caspases and address the importance of recent therapeutic strategies aimed at specifically targeting these proteases in relation to prostate cancer. MATERIALS AND METHODS: We present a background introduction into the role of the caspases in apoptosis and how failure to signal effectively their activation may contribute to prostate cancer progression. Key studies aimed at specifically targeting the caspases as cancer therapy are discussed. RESULTS: Prostate carcinogenesis and apoptosis are related. The deregulation of apoptosis contributes to tumor initiation, metastasis and progression to the androgen insensitive state. Conversely the effectiveness of therapy often depends on its ability to induce apoptosis in prostate cancer cells. Identifying abnormalities in the apoptotic signaling pathway has greatly contributed to understanding the biology of prostate cancer. Elucidating caspase regulation has contributed to the design of novel therapies for prostate cancer. CONCLUSIONS: We summarize the physiological and pathological pathways leading to caspase activation in the prostate and describe novel approaches that target these proteases.     

生长抑素对胆囊癌细胞株的致凋亡研究

目的 通过前期实验发现,生长抑素(somatostatin,SST)作用于胆囊癌细胞株(GBC-SD)后,可显著增强阿霉素(doxorubicin,DOX)的杀伤能力[1].该实验旨在研究SST对GBC-SD细胞的诱导凋亡作用,并探讨其发生机制.方法 GBC-SD细胞分为4组:单独SST作用组、单独DoX作用组、联合用药组(SST预处理24 h后,再加入DOX)和对照组.药物作用24、36、48和60 h后,采用FITC-Annexin V/PI试验分别检测各组GBC-SD细胞的凋亡情况;另外运用Western印迹方法 检测SST作用24 h后,GBC-SD细胞内P53蛋白和Bax蛋白表达的变化.结果 SST分别作用24、36、48和60 h后,GBC-SD细胞没有出现明显的细胞凋亡,SST的致凋亡作用仅仅表现出微弱的时间依赖性;而在SST作用24 h后,GBC-SD细胞内的P53蛋白和Bax蛋白的表达都没有明显的变化(P>0.05).结论 SST不能诱导GBC-SD细胞产生明显的细胞凋亡,P53蛋白和Bax蛋白在其中发挥着重要作用.     

Germ cell apoptosis induced by ureaplasma urealyticum infection

Aim: To study the effect of Ureaplasma urealyticum (UU) infection on germ cell apoptosis of male rats. Methods: Male rats were infected artificially with UU serotype 8 (T960). Morphological changes of germ cells in the seminiferous tubules and the lumen of the epididymides were observed under the light microscope. Fluorescence-conjugated polyclonal antibodies to Fas and Fas ligand (FasL) were used to localize Fas and FasL. TUNEL staining of germ cells and Sertoli cells was performed by the AKPase method. TUNEL-positive rate ( % positive cells) and TUNEL-positive area (area occupied by stained cells) were analysed by KS400 Image Analysis System. The DNA laddering analysis was performed by agarose gels electrophoresis. Results: In those rats infected with UU: (1) Exfoliated germ cells were dramatically increased. Many multinucleated giant cells were found in the seminiferous tubules and the lumen of the epididymides. (2) The number of TUNEL-positive cells and the TUNEL-positive area were significantly increased. (3) The expression of Fas and FasL in germ cells and Sertoli cells was up-regulated. (4) Discrete bands of fragmented DNA were found in the testicular cells. Conclusion: In male rats, germ cell apoptosis was increased in UU infection.     

Germ cell apoptosis induced by progesterone in rats

Objectives:To document the effect of progesterone exposure with large dose and long term on spermatogenesis,especially on the germ cell apoptosis in rats.This study was also to evaluate the toxicity of progesterone in the reproductive system when administered with large doses and long term in men.Methods:Groups of adult male SD rats were administered with 37.5,75 and 150 mg/kg depot-medroxyprogesterone acetate(DMPA)per two-weeks for 12 or 18 weeks.At the end of treatment,each male rat was paired with one adult female SD rat to estimate the reproductive function.Serum testosterone concentration was analyzed in duplicate by radioimmunoassay(RIA).The pathological changes of testes,epididymis,and prostate were checked under light microscopic,epididymis was also used for sperm count,and fresh testis tissue was used for apoptosis assessment by flow cytometry.Results:After treatment with DMPA,weights of gonad,the ratio of testes/body,the ratio of epididymides/body,and the ratio of prostate/body decreased significantly(P<0.01).The level of serum testosterone,sperm count,sperm activity decreased significantly(P<0.01)while abnormality of sperm increased significantly(P<0.01).The embryonic number in uterus of pairing female rat decreased significantly after DMPA treatment.Compared with control,the number and the ratio of apoptotic germ cell increased dramatically(P<0.01)along with dose increase or treating prolongation of DMPA,which analyzed by flow cytometry.Conclusion:In summary,in addition to inhibition of pituitary gonadotrophin and subsequently deprivation of androgen,progesterone(DMPA)inhibits spermatogenesis by the induced germ cell apoptosis.The reproductive toxicity of DMPA administrated with large doses and long term is confirmed.     

肾上腺髓质素对缺氧复氧诱导的大鼠近端肾小管上皮细胞凋亡的影响及其机制

目的 探讨肾上腺髓质素(ADM)对缺氧复氧(HR)诱导的大鼠近端肾小管上皮细胞(NRK-52E)凋亡的影响及其机制.方法 体外培养的NRK-52E细胞,随机分为4组:正常对照组、HR组、空质粒+HR组、ADM质粒+HR组.采用Fugene HD转染试剂,将pcDNA3.1-myc-his B空质粒和ADM真核表达质粒分别转染至NRK-52E细胞内,应用免疫细胞化学的方法检测转染效率,转染成功48 h后制作HR模型.锥虫蓝摄取法进行细胞计数并计算细胞存活率,分光光度法检测上清液中乳酸脱氢酶(LDH)含量评价细胞活力;Annexin V和PI染色结合流式细胞仪技术检测细胞凋亡率;RT-PCR法检测ADM、Bax、Bcl-2、Fas的mRNA表达;Western印迹法检测活性半胱氨酸天冬氨酸蛋白酶3、8、9(Caspase-3、8、9)的蛋白表达.结果 HR组ADM的表达显著高于正常对照组(P＜0.05).ADM质粒+HR组的ADM表达显著高于空质粒+ HR组(P＜0.05).与正常对照组相比,HR组活细胞计数和细胞存活率显著降低,LDH含量及细胞凋亡率显著升高,Bax、Bcl-2、Fas、活性Caspase-3、8、9表达显著上调,Bax上调更明显,故Bax/Bcl-2升高(均P＜0.05).与HR组相比,ADM质粒+HR组活细胞计数和细胞存活率显著升高,LDH含量及细胞凋亡率显著降低,Bax、Fas、活性Caspase-3、8、9表达显著下调,Bcl-2表达进一步上调,Bax/Bcl-2降低(均P＜0.05).空质粒+HR组和HR组比较,上述各指标差异均无统计学意义(P＞0.05).结论 ADM在NRK-52E细胞中的高表达可以减轻HR诱导的细胞凋亡,其机制至少部分是通过抑制线粒体通路和死亡受体通路实现的.     

肾上腺髓质素对大鼠肾缺血再灌注损伤中肾小管上皮细胞凋亡的影响及机制研究

目的 观察肾上腺髓质素(adrenomedullin,AM)对大鼠肾缺血再灌注损伤(ischemia reperfusion injury,IRI)中肾小管上皮细胞凋亡的影响,并探讨其机制.方法 Wistar大鼠32只,随机分为4组:假手术组和IRI组各6只,转染空质粒组和转染AM质粒组各10只.大鼠右肾切除后1周,用超声微泡造影剂介导的基因转染方法将大鼠AM真核表达质粒转染大鼠肾脏,1周后采用免疫组织化学方法检测转染效率.转染成功后夹闭左肾动脉45 min制作肾IRI模型,于再灌注24 h后留取肾组织标本.TUNEL染色检测肾组织细胞凋亡,RT-PCR检测肾组织Bcl-2、Bax和Fas的mRNA表达,蛋白质印迹法检测caspase-3、caspase-8和caspase-9蛋白质表达.结果 转染AM质粒组的AM表达显著高于转染空质粒组(0.51±0.09和0.23±0.05,P＜0.05).与假手术组相比,IRI组肾组织细胞凋亡率明显增加[(38.79±7.52)%和(2.89±0.52)%,P＜0.05];肾组织Bax、Bcl-2、Fas、caspase-3、caspase-8和caspase-9表达上调,分别为0.72±0.18和0.23±0.04、0.80±0.12和0.38±0.06、1.24±0.25和0.39±0.09、0.76±0.13和0.38±0.08、0.92±0.14和0.32±0.06、0.89±0.12和0.42±0.09(P＜0.05),Bax/Bcl-2升高(0.91±0.18和0.61±0.08,P＜0.05).转染AM质粒组肾组织凋亡细胞数、Bax、Fas、caspase-3、caspase-8和caspase-9表达下调,分别为(19.36±6.78)%、0.48±0.11、0.62±0.07、0.53±0.08、0.46±0.08、0.51±0.12,与IRI组比较差异均有统计学意义(P＜0.05);Bcl-2表达进一步上调为1.23±0.25,Bax/Bcl-2降低为0.44±0.12,与IRI组比较差异均有统计学意义(P＜0.05).转染空质粒组和IRI组比较,上述各指标差异均无统计学意义(P＞0.05).结论 AM能减轻肾IRI引起的肾小管上皮细胞凋亡,其部分机制可能是通过抑制caspase依赖的内、外源性凋亡途径实现的.

Abstract：

Objective To investigate the effect and mechanism of adrenomedullin (AM) on apoptosis of renal tubular epithelial cell in rats induced by renal ischemia reperfusion injury. Methods Thirty-two Wistar rats were randomly divided into 4 groups: control group, IRI group, empty plasmid group and AM group. One week after removing the right kidney, eukaryotic expression vector encoding rat AM gene was transfected into the left kidney using an ultrasound-microbubble mediated system. After 1 week the transfer efficiency was detected by immunohistochemical method . Renal IRI model induced by clamping left renal arteries for 45 min followed by reperfusion for 24 h. Tubular cell apoptosis was detected by TUNEL assay. Bcl-2, Bax and Fas expressions were examined by RT-PCR. The expressions of caspase-3, caspase-8 and caspase-9 were determined by Western bolt analysis. Results The expression of AM in the AM group was significantly higher than the empty plasmid group (0.51±0.09 vs 0.23±0.05; P<0.05). Compared with the control group, the apoptosis rate of renal tubular cell in the IRI group was significantly higher [(38.79±7.52)% vs (2.89±0.52)%; P<0.05]. The expressions of Bax, Bcl-2, Fas, caspase-3, caspase-8 and caspase-9 were also significantly increased (0.72±0.18 vs 0.23±0.04, 0.80±0.12 vs 0.38±0.06, 1.24±0.25 vs 0.39±0.09, 0.76±0.13 vs 0.38±0.08, 0.92±0.14 vs 0.32±0.06, 0.89±0.12 vs 0.42±0.09; P<0.05). Bax/Bcl-2 was also significantly increased (0.91±0.18 vs 0.61±0.08; P<0.05). Compared with the IRI group, AM pretreatment significantly decreased the apoptosis rate of renal tubular cells [(19.36±6.78)% vs (38.79±7.52)%; P<0.05]. AM inhibited the up-regulation of Bax, Fas, caspase-3, caspase-8 and caspase-9, while promoting the up-regulation of Bcl-2 (0.48±0.11 vs 0.72±0.18, 0.62±0.07 vs 1.24±0.25, 0.53±0.08 vs 0.76±0.13, 0.46±0.08 vs 0.92±0.14, 0.51±0.12 vs 0.89±0.12, 1.23±0.25 vs 0.80±0.12; P<0.05). Bax/Bcl-2 significantly decreased (0.44±0.12 vs 0.91±0.18; P<0.05). The above parameters had no significant diffe-rence between the empty plasmid group and the IRI group (P>0.05). Conclusion AM can reduce apoptosis of renal tubular epithelial cell induced by renal IRI, the mechanism of which might be achieved by inhibiting caspase-dependent intrinsic and extrinsic pathways.     

A20转染对大鼠肾脏缺血再灌注后肾小管上皮细胞凋亡的影响

目的 观察和分析A20基因转染对大鼠肾脏缺血再灌注后诱发的肾小管损伤及凋亡的影响。 方法 通过构建人源的A20基因表达载体pcDNA3.1-A20及空质粒载体pcDNA3.1,并将其表达载体及pcDNA3.1空质粒载体转化到感受态大肠杆菌。大肠杆菌采用固体LB培养基划盘,37℃恒温培养箱培养12～16 h,挑取单菌落,接种于5 ml 含氨苄青霉素的LB液体培养基中,置37℃恒温摇床,转速210 r/min,培养12～16 h,后接种于200ml含氨苄青霉素的LB液体培养基中继续培养12～16 h,提取质粒DNA,并对其进行1%琼脂糖凝胶电泳,以确定是目的基因。雄性SD大鼠24只,随机分为3组：生理盐水组、A20组、空质粒组,每组8只大鼠。术前48 h,脂质体Lipofectamine 2000包裹DNA,即脂质体pcDNA3.1-A20 + 生理盐水至250 ul (15 ul脂质体加10 ug构建的质粒DNA混匀后加入生理盐水至250 ul)、脂质体-pcDNA3.1 + 生理盐水至250 ul (方法同上), 混匀室温静置30min,分别通过大鼠尾静脉注射。手术方法：打开腹腔,分离左侧肾脏动脉和静脉,夹闭左侧肾脏动静脉45 min,观察大鼠左侧肾脏缺血后颜色变化,期间行右肾切除术,后左侧肾血管再灌注,制成大鼠肾脏缺血再灌注损伤模型。术后24 h收获大鼠,采用全自动生化分析仪检测肾功能,肾组织HE染色行病理学检测,TUNEL法检测肾组织细胞凋亡的情况。 结果 A20组Scr、BUN水平明显低于空质粒组和生理盐水组（P均 ﹤0.05）,差异有统计学意义。各组肾小管都有不同程度的损伤,A20组与生理盐水组及空质粒组比较,肾小管扩张,肾小管上皮细胞刷状缘脱落、坏死,蛋白管型等肾脏组织病理损伤明显减轻（P均 ﹤0.05）,差异有统计学意义;空质粒组与生理盐水组比较,差异无统计学意义（P＞ 0.05）。肾小管上皮细胞凋亡多见于远端小管,A20组与生理盐水组和空质粒组比较,凋亡细胞数明显减少,差异有统计学意义（P均 ﹤0.05）;生理盐水组和空质粒组比较无显著性差异（P ＞0.05）。 结论 A20基因转染能明显减轻肾脏缺血再灌注损伤,其机制可能与抑制肾小管上皮细胞凋亡有关。