骨髓间充质干细胞干预对缺血再灌注诱导肾小管上皮细胞凋亡的影响

目的：观察骨髓间充质干细胞（mesenchymal stemcells,MSCs）对缺血再灌注（ischemia/reperfusion,I/R）诱导的急性肾损伤模型小鼠肾小管上皮细胞（renal tubular epithelial cells,RTECs）凋亡的保护作用及机制。方法：Percoll密度梯度离心结合贴壁培养法有效分离出C57BL/6小鼠的骨髓间充质干细胞（mMSCs）。雄性C57BL/6小鼠45只,分为正常对照组（15只）、I/R组（15只、夹闭双侧肾蒂30min开放）、I/R＋mMSCs组（15只、夹闭双侧肾蒂30min开放的同时尾静脉注射mMSCs）。造模并干预后,于1d、2d、3d、7d、14d分别处死部分小鼠,留取动脉血及肾组织,检测血尿素氮（BUN）及肌酐（Scr）,制作肾组织切片行HE染色进行肾小管损伤程度评分,TUNEL法检测RTECs的凋亡,Western Blot法检测建模后第2天肾小管组织中Caspase-3、Bcl-2蛋白水平的表达。结果：I/R后小鼠的BUN及Scr均显著高于正常对照组,但同一时间点I/R＋mMSCs组小鼠的BUN及Scr水平较I/R组为低,以术后第7天差异最为显著（P〈0.01）,肾小管损伤程度评分也有着显著降低。TUNEL检测表明I/R可诱导RTECs发生明显的凋亡,以术后第2天凋亡指数（apoptosis index,AI）最高（46.71±11.20）（P〈0.01）,而mMSCs干预可显著降低各时间点RTECs的凋亡水平（P〈0.05或P〈0.01）,至14d时AI基本恢复至对照组水平。Western blot进一步显示：I/R＋mMSCs组小鼠的肾组织中Caspase-3蛋白水平明显下降（1.16±0.33,P〈0.01）,而Bcl-2水平却有明显增高（0.94±0.27,P〈0.01）。结论：移植的MSCs对I/R诱导的肾损害小鼠RTECs凋亡具有抑制作用,从而有利于肾小管损伤的早期恢复,其保护机制可能与抑制Caspase-3表达,上调Bcl-2表达有关,但其细胞学和分子机制还有待进一步研究。     

骨髓间充质干细胞干预对缺血再灌注致小鼠肾小管上皮细胞损伤的保护作用

目的 观察骨髓间充质干细胞(MSCs)干预对缺血再灌注(I/R)诱导的急性肾损伤小鼠肾小管上皮细胞(RTECs)自身修复的影响.方法 Percoll密度梯度离心结合贴壁培养法分离纯化出C57BL/6小鼠的骨髓间充质干细胞(mMSCs),5-溴脱氧尿嘧啶核苷(BrdU)标记.雄性C57BL/6小鼠45只,分为正常对照组(15只)、I/R组(15只、夹闭双侧肾蒂30 min开放)、I/R+Brdu-mMSCs组(15只、夹闭双侧肾蒂30 min开放的同时尾静脉注射BrdU标记的mMSCs).留取动脉血及肾组织,检测血尿素氮(BUN)及肌酐(Scr)水平,制作肾组织切片行苏木素-伊红(HE)染色,荧光组织化学观察mMSCs在受体小鼠肾组织的分布,免疫组织化学观察RTECs增强细胞核抗原(PCNA)的表达,TUNEL法检测RTECs凋亡,Western blot检测建模后第2天肾小管组织中Caspase-3、bcl-2蛋白的表达.结果 BrdU标记mMSCs的阳性率可达(98.71±0.32)%.I/R+BrdU-mMSCs组小鼠的BUN及Scr水平较I/R组为低,肾小管损伤病理明显减轻,且小鼠的肾脏中可检测到BrdU+细胞的分布.mMSCs干预后,RTECs细胞核PCNA阳性表达明显增多(P＜0.05或P＜0.01),而细胞凋亡的水平却较I/R组明显减少(P＜0.05或P＜0.01).Western blot进一步显示:I/R+BrdU-mMSCs组小鼠的肾组织中Caspase-3蛋白水平明显下降[(1.16±0.33)比(1.64±0.27),P＜0.01],而bcl-2水平却明显增高[(0.94±0.27)比(0.68 ±0.15),P＜0.01].结论 小鼠发生I/R诱导的急性肾损伤后可诱导移植的MSCs向损伤肾组织归巢,锚定在肾脏的MSCs可促进损伤RTECs的再生,抑制其凋亡,从而有助于RTECs的自身修复,延缓肾损害进展.

Abstract：

Objective To observe the effects of mesenchymal stem cells (MSCs) on self-repair of renal tubular epithelial cells ( RTECs) in mice under ischemia/reperfusion ( IR). Methods MSCs in C57BL/6 mice were successfully isolated by Percoll density gradient centrifugation and adherence cultivation, then marked with BrdU. Forty-five healthy male C57BL/6 mice were assigned to control group (n =15 ) , I/R group (n = 15 , clamping bilateral renal pedicles and then reopening after 30 min) , I/R + BrdU-MSCs group (n = 15 , clamping bilateral renal pedicles and then reopening after 30 min, meanwhile, BrdU-marked MSCs were injected through caudal vein into the body of model mice). One, 2,3,7 and 14 days later, the mice were killed (n = 3/each group) , and blood and kidneys were obtained. Serum creatinine (Scr) and urea nitrogen (BUN) were determined, and mice kidneys were stained with Hematoxylin and Eosin ( HE) to observe their pathological changes. The distribution of MSCs in mice was observed by using fluorescence histochemistry. The expression of proliferating cell nuclear antigen ( PCNA) in RTECs was assessed by using immunohistological staining. The apoptosis of RTECs was detected by using TUNEL. The protein levels of Caspase-3 and bcl-2 in renal tubules on the day 2 after establishing the model were detected by using Western blotting. Results The positive BrdU marking ratio was (98. 71 ±0. 32) % in MSCs.As compared with I/R group, the levels of BUN and Scr in I/R + BrdU-MSCs group were significantly reduced, and pathological changes in renal tubules were alleviated significantly. BrdU-marked MSCs desposited in the kidneys of I/R + BrdU-MSCs group. The positive PCNA expression of RTECs was increased significantly after intervention of BrdU-MSCs (P ＜0. 05 or P ＜0. 01) , while the apoptosis relieved significantly. Western blotting analysis revealed: as compared with I/R group, the level of Caspase-3 in I/R + BrdU-MSCs group was decreased notably [(1.16±0.33) vs (1.64±0.27), P＜0.01], while the level of bcl-2 increased significantly [(0.94±0.27) vs (0.68±0.15), P＜0.01). Conclusion Acute renal injury by I/R can induce MSCs homing to injured kidney and anchoring here. The anchored MSCs can contribute to RTECs' self-repair of mice under ischemia/reperfusion, inhibit their apoptosis, which is helpful to the RTECs' self-repair and can delay the progression of renal injury.     

脐带间充质干细胞调节炎性微环境干预急性肾损伤的效应研究

目的：观察移植外源性脐带间充质干细胞（UC-MSCs）对小鼠急性肾损伤（AKI）炎性微环境的影响及对肾组织的修复作用。方法：分离培养孕后期C57BL/6雌性小鼠的UC-MSCs。另取雌性C57BL/6小鼠60只,随机分为正常对照组、AKI组、AKI＋MSC移植组,每组20只。AKI组和AKI＋MSC组用微型动脉夹夹闭小鼠双侧肾蒂45 min复制AKI模型,并于模型制备成功时腹腔内注射生理盐水0.2 ml（AKI组）或1＆#215;106 UC-MSCs（AKI＋MSC组）。于第2天和第7天每组活杀10只小鼠,取眼球血及肾组织,检测血尿素氮（BUN）及血肌酐（SCr）水平;肾组织行HE染色,观察组织病理学变化;ELISA法检测肾组织匀浆中促炎因子IL-1β、TNF-α、干扰素-1（IFN-1）及抗炎因子碱性成纤维细胞生长因子（bFGF）、IL-10、B淋巴细胞瘤-2（Bcl-2）的水平。结果：2 d时AKI组小鼠肾小管上皮细胞肿胀,胞质空泡性变,BUN和Cr均显著高于正常对照组,提示造模成功后肾小管受损严重,7 d稍有减轻;AKI＋MSC移植组小鼠肾功能在2 d时较AKI组有所恢复,肾组织病理学变化明显减轻（P＜0.01）,7 d基本恢复正常。ELISA结果显示,与正常对照组比较, AKI组各时间点肾组织匀浆中促炎因子的水平均显著升高（P＜0.01或P＜0.05）,抗炎因子的水平均显著降低（P＜0.01或P＜0.05）,2 d较7 d更加明显。各时间点AKI＋MSC组抗炎因子的水平较AKI组明显升高,促炎因子的水平明显下降,但与正常对照组比较差异均有显著性（P＜0.01或P＜0.05）,7d较2 d改善更明显。结论：MSC可通过减轻AKI肾组织炎症反应,调节损伤肾脏组织微环境中的细胞因子水平发挥保护肾损害的修复作用。     

骨髓间充质干细胞对缺血再灌注损伤肾小管上皮细胞增殖和凋亡的影响

目的：探讨外源性骨髓间充质干细胞（MSCs）移植对缺血再灌注损伤（I/R）后肾小管上皮细胞增殖和凋亡的影响。方法：将雄性SD大鼠MSCs用DAPI标记后注入受体雌性SD大鼠体内。30只受体大鼠随机分为3组：假手术对照组（C组）、MSCs＋I/R组（M组）、DMEM-F12＋I/R组（D组）,每组10只。7d后观察肾功能,肾脏病理改变,采用原位末端标记法检测细胞凋亡指数,免疫组化法检测增殖细胞核抗原（PCNA）的表达,并观察DAPI标记的MSCs在受体大鼠肾脏的分布情况。结果：I/R后第7天,M组在肾功能、肾脏病理改变上,均明显好于D组;肾组织内PCNA＋细胞数和凋亡指数均低于D组。I/R后7d内未发现MSCs定位于肾组织中。结论：外源性MSCs可以促进I/R损伤后肾小管上皮细胞的增殖和减少细胞凋亡,从而有利于肾小管损伤的早期恢复。     

大鼠肾脏缺血再灌注后IL-6变化及姜黄素预处理的影响

目的：观察大鼠肾脏缺血再灌注（IRI）的不同时间组炎性细胞因子白细胞介素-6（IL-6）在肾组织和血液中的含量变化及姜黄素预处理的影响。方法：采用大鼠肾缺血再灌注（IR）模型（将大鼠右肾切除,夹闭左肾蒂,60min后松开使左肾再灌注）,用双抗体夹心ELISA法动态检测肾组织和血液中IL-6含量,以及用生化分析仪测定BUN、Scr等指标变化。取肾脏称重,计算肾系数：肾重/体重,同时观察肾脏病理学变化。结果：肾组织中IL-6含量在单纯缺血组、R4h和R24h组均明显低于对照组（P〈0.05）,而R1h组与对照组水平差异无统计学意义,但与缺血组比较,其增高差异有统计学意义（P〈0.01）。血清IL-6水平在R1h组明显高于单纯缺血组（P〈0.01）。姜黄素干预可使R4h和R24h组的IL-6含量较未处理组增高（P〈0.01）,同时使R4h组BUN、Scr及肾系数也明显增高（P〈0.01或P〈0.05）,使R24h组的Scr明显降低（P〈0.01）,但BUN及肾系数无明显变化。结论：在再灌注的早期,肾组织和血液中IL-6的含量升高,随后下降接近于单纯缺血水平。姜黄素预处置使IL-6增多的同时加重早期肾缺血再灌注损伤（IRI）,姜黄素早期使肾功能障碍加重的作用是否与IL-6增加有关,值得进一步探讨;随着再灌注时间延长,姜黄素治疗作用逐渐显示。姜黄素与IL-6之间具体的作用机制有待进一步研究。     

普罗布考防治大鼠顺铂急性肾损伤的实验研究

目的：复制大鼠顺铂急性肾损伤模型,研究氧化应激与核转录因子Sp1及凋亡的关系;探讨普罗布考对顺铂急性肾损伤的保护作用及作用机制。方法：24只SD雄性大鼠被随机分为生理盐水对照组、顺铂模型组、普罗布考干预组、普罗布考对照组,每组6只;检测尿N-乙酰-β-D-氨基葡萄糖甘酶（NAG）、血清肌酐（Scr）、血尿素氮（BUN）、肾组织匀浆液丙二醛（MDA）和谷胱甘肽过氧化物酶（GSH-Px）,光镜观察肾脏病理改变;采用免疫组化染色检测肾组织Sp1蛋白表达;采用TUNEL染色检测肾小管上皮细胞凋亡。结果：与生理盐水对照组和普罗布考对照组相比,顺铂模型组大鼠血清BUN和Scr,尿NAG酶,肾脏组织匀浆MDA含量显著升高,肾组织匀浆GSH-Px活力显著下降（P〈0.01）;肾脏指数、肾小管损伤分数和肾小管上皮细胞凋亡百分比均明显增加（P〈0.01）;肾组织Sp1蛋白的表达上调。采用普罗布考干预后血清BUN和Scr,尿NAG酶,肾脏组织匀浆MDA含量显著下降（P〈0.05）;肾组织匀浆GSH-Px活力显著升高;肾脏指数、肾小管损伤分数和肾小管上皮细胞凋亡百分比均明显降低（P〈0.01）;肾组织Sp1蛋白的表达下调。结论：氧化应激和核转录因子Sp1在顺铂所致大鼠肾毒性中起一定作用;普罗布考对顺铂所致大鼠肾毒性有保护作用,其机制可能与抗氧化、抑制肾小管上皮细胞凋亡、下调肾组织Sp1蛋白表达有关。     

雷公藤内酯醇对肾缺血再灌注大鼠凋亡诱导因子及细胞间黏附分子-1表达的影响

目的:探讨雷公藤内酯醇(TP)对肾缺血再灌注(I/R)大鼠的肾保护作用,及对凋亡诱导因子、细胞间黏附分子-1的影响。方法:48只雄性Wistar大鼠随机分为假手术组、I/R模型组(I/R组)、TP高、中、低剂量干预组、泼尼松对照组(Pred组)。采用夹闭双侧肾动脉30 min,再灌注18 h的方法制作肾I/R大鼠模型。检测血肌酐(Scr)、尿素氮(BUN),原位末端标记法检测肾小管上皮细胞凋亡,观察肾病理改变,计算肾小管损伤(ATN)评分。Western印迹和RT-PCR分别检测AIF、ICAM-1蛋白和基因表达。结果:(1)I/R组血Scr、BUN、ATN评分及细胞凋亡指数较假手术组显著升高(P<0.01);与I/R组比较,TP各组以上指标均改善(P<0.01),pred组血Scr、BUN、ATN评分改善(P<0.01),但细胞凋亡指数无明显变化(P>0.05)。(2)I/R组大鼠肾组织AIF、ICAM-1较假手术组高表达(P<0.01);与I/R组比较,TP各组二者表达均减弱(P<0.01),pred组ICAM-1表达减弱(P<0.01)但AIF表达差异无统计学意义(P>0.05)。结论:TP对肾I/R大鼠具有肾保护作用,其部分机制可能与抑制肾小管上皮细胞过度凋亡及AIF、ICAM-1表达有关。     

冬虫夏草通过抗氧化抗炎抑制细胞凋亡改善顺铂肾损伤

目的:观察顺铂(cisplatin,CP)小鼠肾损伤后肾组织氧化应激、炎症及细胞凋亡情况以及冬虫夏草干预的影响,探讨冬虫夏草的肾保护作用机制。方法:用腹腔注射cisplatin的方法建立顺铂肾损伤模型,28只8周龄C57BL/6小鼠随机分为空白对照组、CP组、冬虫夏草组、冬虫夏草+CP组,每组7只。72 h后处死小鼠,检测各组小鼠血清尿素氮(BUN)和血肌酐(Scr),肾组织超氧化物歧化酶(SOD)、丙二醛(MDA),HE染色观察小鼠肾小管间质病理变化,TUNEL法检测肾小管上皮细胞凋亡情况; ELISA的方法测定组织中TNF-α、IL-1β、IL-6。结果:与对照组及冬虫夏草相比,CP组与冬虫夏草+CP组小鼠的BUN、Scr及肾组织MDA水平增高(P0.01),肾组织SOD降低(P0.01),肾小管病理半定量计分显示小管间质损伤明显加重(P0.01),TUNEL阳性细胞表达增多(P0.01),TNF-α、IL-1β、IL-6明显增加(P0.01);与CP组相比较,冬虫夏草+CP组的血清BUN、Scr及肾组织MDA水平下降(P0.01),肾组织SOD上升(P0.05),肾小管病理半定量计分显示冬虫夏草+CP组较CP组小管间质损伤明显改善(P0.01),TUNEL阳性细胞表达明显减少(P0.01),TNF-α、IL-1β、IL-6明显减少(P0.01)。结论:顺铂肾损伤肾组织中MDA明显增高,SOD活性降低,TNF-α、IL-1β、IL-6及凋亡细胞显著增加,提示顺铂至急性肾损伤与其诱导氧化应激、炎症及细胞凋亡有关。冬虫夏草干预后肾组织中MDA明显降低,SOD活性升高,TNF-α、IL-1β、IL-6及凋亡细胞显著减少,提示冬虫夏草可能通过抑制氧化应激、炎症及肾小管上皮细胞凋亡而达到肾保护作用。     

益肾胶囊对糖尿病肾病大鼠肾组织SOCS-3、TLR4、IL-6表达的影响

目的：观察益肾胶囊对糖尿病肾病（DN）大鼠模型肾组织中细胞因子信号抑制物3（SOCS-3）、Toll样受体4（TLR4）及白细胞介素-6（IL-6）表达的影响。方法：将40只Wistar系雄性大鼠随机分为4组,即：正常对照组（N组）、DN模型组（DN组）、DN模型＋益肾胶囊治疗组（DN＋Y组）及DN模型＋氯沙坦钾治疗组（DN＋L组）,利用单侧肾切除＋腹腔注射链脲佐菌素,建立DN大鼠模型。记录大鼠体重,检测血糖、24h尿蛋白定量、血肌酐（Scr）、尿素氮（BUN）等指标;取肾组织行HE染色,进行病理组织学观察;用免疫组化方法检测肾组织中SOCS-3、TLR4及IL-6的表达。结果：12周末,DN组大鼠的24h尿蛋白定量、Scr、BUN均高于N组（P〈0.05）,肾组织中SOCS-3、TLR4及IL-6表达水平明显高于N组（P〈0.05）;DN＋Y组大鼠24h尿蛋白定量、Scr、BUN均低于DN组（P〈0.05）,肾组织SOCS-3表达水平明显高于DN组（P〈0.05）,而TLR4及IL-6表达水平明显低于DN组（P〈0.05）;DN＋L组与DN＋Y组24h尿蛋白定量、Scr、BUN、SOCS-3、TLR4及IL-6的差异无统计学意义（P〉0.05）。结论：益肾胶囊可能通过调节SOCS-3、TLR4及IL-6在肾组织中的表达,降低DN的炎症反应,从而延缓DN的进展。     

益肾胶囊对糖尿病肾病大鼠模型肾组织TLR4表达的影响

目的：观察益肾胶囊对糖尿病肾病（DN）大鼠模型肾组织Toll样受体4（toll-like receptor4,TLR4）、白细胞介素-6（IL-6）及白细胞介素-8（IL-8）表达水平的影响。方法：36只Wistar雄性大鼠随机分成正常对照组、DN模型组、益肾胶囊治疗组,每组12只,利用单侧肾切除加腹腔注射链脲佐菌素建立DN大鼠模型,连续给药12周。记录大鼠体重、观察24h尿蛋白定量、血肌酐（Scr）、尿素氮（BUN）变化;取肾组织行病理组织学观察;用免疫荧光方法检测肾组织中TLR4、IL-6及IL-8的表达水平的变化。结果：12周末,DN模型组大鼠的24h尿蛋白定量、Scr、BUN均高于正常对照组（P〈0.05）,肾组织中TLR4、IL-6及IL-8表达水平明显高于正常对照组（P〈0.05）;益肾胶囊治疗组大鼠24h尿蛋白定量、Scr、BUN均低于模型组（P〈0.05）,肾组织TLR4、IL-6及IL-8表达水平明显低于DN模型组（P〈0.05）。结论：益肾胶囊可能通过调节肾组织TLR4、IL-6及IL-8的表达,减少DN的炎症反应,从而延缓了DN的进展。     

C57BL/6 and 129/Sv mice: genetic difference to renal ischemia-reperfusion

Background: C57BL/6 and 129/Sv are the 2 most commonly used strains of mice in renal ischemia-reperfusion injury (IRI) studies, yet there are currently no studies that contrast differences in the degree of renal injury after ischemia-reperfusion. Methods: To evaluate renal IRI in male C57BL/6 and 129/Sv mice, we performed unilateral clamping of the left renal pedicle for 45 minutes and compared the degree of renal tissue damage and function. To measure function and tissue damage we examined: glomerular filtration rate (GFR; by inulin clearance), renal blood flow (RBF; by p-aminohippurate [PAH] clearance), renal morphology, immunohistochemistry for infiltrating leukocytes, and fibrogenic markers by Sirius red staining. Results: After unilateral IRI, 129/sv mice had significantly less GFR and RBF disfunction at both day 14 (d14) and d28. 129/sv mice also had significantly less acute tubular necrosis on d1 and fewer infiltrating leukocytes on d28, as well as less collagen deposition on d28 than C57BL/6 mice. Conclusions: C57BL/6 mice were much more sensitive to damage caused by renal IRI than are 129/Sv mice.     

红细胞生成素对模拟急性肾损伤微环境下培养骨髓间充质干细胞增殖的影响及机制探讨

目的 观察经红细胞生成素（EPO）干预后,体外模拟急性肾损伤（AKI）微环境下培养骨髓间充质干细胞（MSC）的分裂增殖情况,并探讨产生这种变化的可能机制。 方法 抽取C57BL/6小鼠的骨髓,经Percoll密度梯度离心联合贴壁培养法分离纯化出小鼠MSC（mMSC）,以流式细胞仪鉴定。夹闭雄性C57BL/6小鼠双侧肾蒂30 min再开放30 min的方法制作AKI鼠模型,即刻取双侧肾脏皮质制作缺血再灌注（IR）肾脏匀浆上清。取扩增第3代的mMSC分组培养：A组：含10%胎牛血清的低糖DMEM培养基;B组：含10%胎牛血清的低糖DMEM培养基＋IR肾脏匀浆上清,体外模拟AKI微环境干预mMSC;C组：含10%胎牛血清的低糖DMEM培养基＋IR肾脏匀浆上清+不同浓度EPO（1、5、10、50 U/ml）。培养1、3、5、7 d。CCK-8法检测各组培养mMSC的增殖,TUNEL法检测mMSC凋亡,Western印迹法检测mMSC表面EPO受体（EPOR）及增殖凋亡相关信号通路蛋白的表达。 结果 CCK-8法检测显示,经IR肾脏匀浆上清干预后,不同时间点mMSC的增殖效应显著减弱（P ＜ 0.01）,而TUNEL检测表明其胞核染色阳性细胞的百分比显著高于A组（P ＜ 0.01）;给予EPO干预后,mMSC的增殖能力增强,胞核染色阳性细胞百分比降低,具有浓度依赖效应。Western印迹结果显示,第3代mMSC表面存在EPOR表达,培养5 d后EPOR相对表达量为0.092±0.015。EPO以剂量和时间依赖性降低AKI微环境下凋亡相关蛋白caspase-3的表达,同时上调凋亡抑制蛋白Bcl-2的表达。用10 U/ml EPO干预5 d后,相对于B组,磷酸化蛋白酪氨酸激酶2及磷酸化信号转导和转录因子的表达均显著上调（均P < 0.01）。 结论 EPO能促进体外AKI微环境干预下培养mMSC的增殖,减轻其凋亡,该效应经EPOR介导,并与增殖凋亡相关信号通路蛋白有关。     

脑缺血预处理对小鼠脑缺血再灌注损伤的保护作用

目的 研究脑缺血预处理对脑缺血再灌注损伤的保护作用。方法 C57BL/6 小鼠分4组,无缺血对照组行假手术,预处理对照组夹闭双侧颈总动脉6min,缺血组夹闭双侧颈总动脉18min,预处理组经6min缺血预处理后48h再行18min脑缺血。末次缺血后3d使用TUNEL原位标记法检测海马区神经原的DNA断片化改变,末次缺血后7d,用甲酚紫染色及微小管相关蛋白2免疫组化染色法观察海马区神经元损伤。结果 6min脑缺血未导致海马神经元缺失,18min脑缺血造成双侧海马神经元大量缺失,6min预处理明显减轻18min脑缺血所造成的神经元损伤及凋亡。结论 脑缺血预处理对脑缺血再灌注损伤有保护作用,此预处理模型为在基因水平研究脑缺血预处理保护作用的分子机制提供了一种新的手段。     

Preoperative fasting induces protection against renal ischemia/reperfusion injury by a corticosterone‐independent mechanism

Three days of fasting protects mice against lethal renal ischemia–reperfusion (I/R) injury. We hypothesize that the protection imposed by fasting is mediated by increased levels of corticosterone, induced by the stress of food deprivation. C57Bl/6 mice were fasted for 3 days after which serum corticosterone levels were determined. Mice underwent a bilateral adrenalectomy (ADX). Ten days later, they were either fasted or given a corticosterone receptor antagonist while fasting. Bilateral renal I/R injury was induced by clamping the artery and vein of the left and right kidney simultaneously for 37 min. Survival and kidney function were determined. Fasting significantly increased corticosterone levels. Only 8% of the ADX mice which were fasted prior to I/R injury survived, whereas all sham‐ADX operated mice survived I/R injury after fasting. After ADX and fasting, 70% of the mice subjected to sham I/R succumbed to the surgical procedure. After fasting with concomitant blockade of the glucocorticoid receptor all animals survived renal I/R. Three days of fasting protects against I/R injury and increases serum corticosterone levels. ADX renders mice incapable of withstanding subsequent abdominal surgery. Glucocorticoid receptor blockade does not interfere with the protective effects of fasting. Thus, the protection against renal I/R injury induced by preoperative fasting is mediated by corticosterone‐independent mechanisms.     

Persistent renal and extrarenal immune changes after severe ischemic injury

BACKGROUND: Renal ischemia/reperfusion (I/R) injury is associated with delayed graft function and decreased long-term allograft function. However, most experimental studies evaluating renal I/R injury have focused on acute events after ischemia. T cells are potential candidates to link preservation injury, alloimmunity, and fibrosis. We hypothesized that severe renal I/R injury would generate long-term kidney damage and immune changes. METHODS: C57BL/6 mice underwent 60 minutes of warm unilateral I/R injury or sham surgery and were studied for 6 weeks. Serum creatinine, renal histology, and albumin excretion were measured. Phagocyte infiltration, CD4+ infiltration, renal cytokine expression, and splenic lymphocyte intracellular cytokine production were also measured in mice at 6 weeks. RESULTS: Serum creatinine levels rose following 60 minutes of unilateral I/R injury compared to sham mice. Histologic analysis of ischemic kidneys at 6 weeks revealed a pronounced loss of tubular architecture and infiltration of inflammatory cells. Phagocyte and CD4+ T-cell infiltration were significantly increased in ischemic kidneys. This was accompanied by a significant increase in interleukin (IL)-1beta and regulated upon activation, normal T-cell expressed and secreted (RANTES) expression. Despite similar splenic CD4 and CD8 numbers, intracellular cytokine staining of T cells revealed a significant increase in interferon-gamma (IFN-gamma) in I/R injury mice compared to sham mice. CONCLUSION: Persistent renal and extrarenal immune responses occur after a single episode of severe I/R injury. These immune processes resulting from injury could in turn have long-term consequences on progression of renal disease in transplanted and native kidneys.     

Pretreatment with granulocyte colony-stimulating factor attenuated renal ischaemia and reperfusion injury via activation of PI3/Akt signal pathway

Aim: Granulocyte colony-stimulating factor (G-CSF) has been shown to exert protective effects in various tissues and experimental models of ischaemia-induced injury. However, the mechanism of renoprotective action in ischaemia/reperfusion (I/R) renal injury of G-CSF was unknown. Methods: Male C57BL/6J mice, subjected to renal ischaemia for 45 min, 48 h and 7 days reperfusion, were administered either saline, wortmannin, G-CSF, and G-CSF plus wortmannin 3 days prior to I/R. Saline-treated group served as the control. At 48 h and 7 days of reperfusion, the mice were killed. Results: Significantly, renal dysfunction and morphological injury were identified at 48 h and 7 days after I/R. Wortmannin pretreatment worsened the renal injury significantly. However, G-CSF pretreatment significantly attenuated renal injury, reduced the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive ratio of renal tubular epithelial cells and inflammation cytokine expression in the kidney. Moreover, G-CSF pretreatment inhibited the expression of Bax and increased the expression of bcl-2 and p-Akt in the kidney. Wortmannin blunted the beneficial effects of G-CSF. Conclusion: The cytoprotective action of G-CSF against I/R injury seems to be associated with its anti-apoptotic action mediated by upregulation of p-Akt signal pathway.     

静脉注射含饱和氢气生理盐水减轻小鼠肾脏缺血再灌注损伤

目的 研究静脉注射含饱和氢气生理盐水对小鼠肾脏缺血再灌注(IR)损伤的保护作用及其机制.方法 健康、雄性的C57BL/6小鼠随机分为3组,每组10只.假手术组(SO组)小鼠仅接受中线开腹、双侧肾蒂游离及关腹操作;缺血再灌注组(IR组)小鼠用无损伤动脉夹同时钳夹双侧肾蒂,阻断45 min,制成肾脏IR损伤模型,并于肾脏缺血同时经尾静脉注射生理盐水,5 ml/kg;实验组小鼠制成肾脏IR损伤模型,并于肾脏缺血同时经尾静脉注射含饱和氢气生理盐水,5 ml/kg.各组小鼠于肾脏再灌注6 h时检测血清尿素氮(BUN)和肌酐(Scr);检测肾组织中丙二醛(MDA)和髓过氧化物酶(MPO)的含量;观察肾脏组织形态学变化并检测肾小管上皮细胞的凋亡情况;观察肾组织中巨噬细胞的浸润情况;检测各组小鼠肾组织中肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、IL-1β和IL-17 mRNA的水平.结果 实验组血清BUN和Scr水平明显低于IR组(P<0.05).实验组肾组织病理改变较IR组明显减轻,其肾小管损伤评分明显低于IR组(P<0.01),肾小管上皮细胞凋亡明显轻于IR组(P<0.05).实验组肾组织内MDA含量低于IR组(P<0.05).实验组小鼠肾组织内中性粒细胞和巨噬细胞的浸润较IR组减少(P<0.05).实验组TNF-α、IL-6、IL-1β和IL-17mRNA的水平均低于IR组(P<0.05).结论 静脉注射含饱和氢气生理盐水能够在一定程度上减轻肾脏IR损伤,其机制可能与抑制肾脏IR后炎症反应有关.