Mechanism of miR-21 in delayed ischemia preconditioning and its protection against subsequent ischemia reperfusion injury in kidney

Objective To investigate the molecular mechanism of protection of ischemia preconditioning on renal ischemia reperfusion injury. Methods Male C57/BL6N mice were randomly divided into two groups: in IR group, 35 min ischemia was induced by occlusion of both renal pedicles followed by 24 h perfusion (I/R). 15 min ischemia was induced 4 days before I/R in IPC group. Blood sample and kidney were collected in IR and IPC group after 24 h perfusion. Serum creatinine (Scr) and histological changes were used to evaluate the renal injury. PHD2 and HIF-1α were evaluated by Western blotting, miR-21 expression was confirmed by real-time PCR. In vitro, hypoxic model was established by 1% O2 in HK-2 cells. Knockdown of miR-21 in hypoxic model was perfermed by locked nucleic acid modified-anti-miR-21 transfection. The levels of miR-21, HIF-1α and PHD2 mRNA were confirmed by real-time PCR. The levels of HIF-1α and PHD2 proteins were tested by Western blotting. Results In vivo, Compared with IR group, the renal function and histological changes were improved in IPC group (P＜0.01). Compared with IR group, the expression of miR-21(P＜0.01) and HIF-1α (P＜0.05) were increased in IPC group, while PHD2 was reduced (P＜0.01). In vitro, hypoxia reduced miR-21. The inhibition of miR-21 could increased the expression of PHD2 (P＜0.05). Conclusions Ischemia preconditioning may exert protection against renal ischemia reperfusion injury by inhibiting PHD2.     

Influence of albumin on expression of NLRP3 inflammasome in renal tubular epithelial cells

Objective To investigate the effect of albumin on expression of NLRP3 inflammasome and its downstream cytokines IL-1β and IL-18 in tubular epithelial cells. Methods Thirty mesangioproliferative glomerulonephritis (MsPGN) patients with different levels of proteinuria were selected, and their renal biopsy samples were stained by PAS and Masson to observe tubular epithelial cells injury and inflammatory cells infiltration. NLRP3, caspase-1, IL-1β and IL-18, as well as different inflammatory cells, were detected by immunohistostaining. In vitro, Western blotting and real-time PCR were employed to detect NLRP3, caspase-1, IL-1β and IL-18 protein and mRNA in HK-2 cells stimulated by bovine serum albumin (BSA) (20 g/L). Results In MsPGN patients with high levels of proteinuria, there were obvious renal tubular epithelial cell injury and inflammatory cells infiltration (all P＜0.05), and the expressions of NLRP3, caspase-1, IL-1β and IL-18 were up-regulated compared to patients with low levels of proteinuria (all P＜0.05). Furthermore, IL-1β and IL-18 expressions were positively correlated with the degree of proteinuria (r=0.836, P＜0.05; r=0.901, P＜0.05). NLRP3, caspase-1, IL-1β and IL-18 protein and mRNA were significantly increased in HK-2 cells stimulated by BSA compared to the control group (all P＜0.05). Conclusions Albumin is able to induce NLRP3 inflammasome activation in tubular epithelial cells, which may be the mechanism of tubulointerstitial injury and inflammation caused by proteinuria.     

Reduction of renal ischemia reperfusion injury by hydrogen sulfide preconditioning through inhibiting oxidative stress

Objective To investigate the possible role of oxidative stress in the protection of hydrogen sulfide during renal ischemia reperfusion. Methods Male Wistar rats were randomly divided into 3 groups: sham operation (Sham) group, renal ischemia reperfusion (IR) group subject to occlusion of left renal pedicle for 45 min then reperfusion for 24 h, and sodium hydrosulfide (NaHS) preconditioning group with continuous infusion of NaHS (450 nmol/min) by left renal artery for 10 min before ischemia reperfusion. Renal injuries were evaluated by PAS staining. The protein levels of NADPH oxidase (NOX) 4, NOX2 were analyzed by Western blotting. The reactive oxygen species (ROS) level of renal tissue was determined by dihydroethidium (DHE) staining assay. Renal superoxide dismutase (SOD), malonic dialdehyde (MDA) and Scr, BUN were evaluated by chromatometry assay. Cell apoptosis were evaluated by TdT-mediated dUTP nick end labeling (TUNEL) staining. Results Compared with Sham group, in IR group the renal NOX4 and NOX2 protein expressions, the existence of acute tubular necrosis and ROS expression were up-regulated (all P＜0.01); MDA, Scr, and BUN were increased and SOD was decreased significantly in IR-treated kidney (all P＜0.01); Moreover, more apoptotic cells presented in the risk zone of IR-treated kindey (P＜0.01). The effects induced by IR were inhibited by NaHS. Compared to that in IR group, NaHS precondition reversed IR-induced damages of renal function and renal tissue, increased SOD activity and decreased MDA expression (all P＜0.05), as well as reduced the expression of NOX4, NOX2 and ROS (all P＜0.05). Moreover, NaHS precondition reduced apoptosis after IR (P＜0.05). Conclusions NaHS alleviates renal ischemia reperfusion injury through inhibiting oxidative stress. Hydrogen sulfide can decrease ROS by inhibiting the activation of NOX, further inhibit the activation of NOD-like receptor, and alleviate kidney damage.     

Role of SIRT1 in renal ischemia-reperfusion injury and its effect on NF-κBp65 - PGC-1α signal pathway in mice

Objective To investigate the role of silent mating type information regulation 2 homologue 1(SIRT1) in renal ischemia-reperfusion(IR) injury and its effect on NF-κBp65 - peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) signal pathway in mice. Methods Seventy-two healthy C57BL/6 male mice were randomly divided into four groups: control group(n=18), sham-operated group(n=18), IR group(n=18), resveratrol group(n=18). Bilateral renal pedicle were clamped for 45 min was adopted to establish the model of acute ischemic renal injury, to give 2% dimethyl sulfoxide or resveratrol by intraperitoneal injection for 7 days before modeling. Determination techniques included routine biochemical methods for the the levels of Scr and BUN, spectrophotometry for the level of superoxide dismutase (SOD), HE staining for the histological changes as well as immunohistochemical method and Western blotting for the expressions of SIRT1, NF-κBp65 and PGC-1α, respectively. Results Compared with that in control and sham-operated groups, the levels of serum Scr and BUN were higher and SOD levels in renal tissues were lower at 12 h and 24 h after operation in IR groups(P＜0.05). HE staining revealed evident pathological lesions including necrosis of renal tubular epithelial cells in IR group. Compared with that in IR group, resveratrol attenuated the above-mentioned changes. Western blotting revealed the up-regulated SIRT1 expression and the activated NF-κB signal pathway, the up-regulated p65 expression and the down-regulated PGC-1α expression subsequent to IR(P＜0.05). Both Western blotting and immunohistochemistry showed that the expressions of SIRT1 and PGC-1α in resveratrol group were up-regulated compared to that in IR group(P＜0.05), while the NF-κBp65 expression in resveratrol group was down-regulated(P＜0.05). Conclusions In mouse model of renal ischemia-reperfusion injury, the activation of SIRT1 can inhibit the NF-κBp65 expression and accordingly up-regulated PGC-1α level, contributing to inhibiting inflammatory reactions and attenuating oxidative stress-induced injury in the protection of the kidneys.     

丙泊酚对大鼠急性肾缺血再灌注损伤的影响

目的 探讨丙泊酚预处理对急性肾缺血再灌注损伤(acute renal ischemia reperfusion injury ,ARIRI)的保护作用及其机制.方法 采用完全随机研究设计(randomized controlled trial,RCT),健康近交系清洁级的雄性SD大鼠63只,随机分为3组:假手术组(A组)、缺血再灌注组(B组)、丙泊酚预处理组(C组),每组21只SD大鼠.采用切除右侧肾,用无损伤微动脉夹夹闭左侧肾蒂60分钟后解除阻断,建立大鼠急性肾缺血再灌注损伤模型.用24号套管针股静脉穿刺置管,实验过程中各组使用微量注射泵注入不同注射液.分别于手术前15分钟、再灌注后2小时、24小时留取血和肾组织标本同时处死大鼠,检测血清尿素氮(BUN)、肌酐(Cr)、超氧化物歧化酶(SOD)、丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)及观察这三个时点肾组织的病理学改变.结果 丙泊酚预处理组各个时点的肾组织病理学变化均轻于缺血再灌注组.缺血再灌注组中血清BUN、Cr、MDA和TNF-α水平增加均高于丙泊酚预处理组(p＜0.05),丙泊酚预处理组血清SOD、IL-6水平均高于缺血再灌注组(p＜0.05).结论 丙泊酚预处理组血清BUN、Cr、MDA、TNF-α、SOD、IL-6水平与缺血再灌注组均有统计学差异.结果 表明丙泊酚能减少氧自由基释放,抑制和减少炎症反应,在急性肾缺血再灌注损伤能起到保护肾脏的作用.     

七氟烷预处理对大鼠心肌缺血再灌注损伤时细胞凋亡的影响

目的 探讨七氟烷预处理对大鼠心肌缺血再灌注损伤时细胞凋亡的影响.方法 成年雄性SD大鼠64只,体重270～350 g,随机分为4组(n=16):假手术组(S组)仅穿线不结扎,心肌缺血再灌注组(I/R组)阻断左冠状动脉前降支缺血30 min,恢复灌注2 h制备心肌缺血再灌注损伤模型,七氟烷组(Sevo组)吸入2.5%七氟烷30 min,七氟烷预处理+心肌缺血再灌注组(SR组)吸入2.5%七氟烷30 min,15 min后制备模型.于再灌注2 h时随机取4只大鼠处死取左心室,采用氯化三苯四唑染色法测定心肌梗死范围,随机取4只大鼠处死取左心室,采用TUNEL法检测凋亡心肌细胞,计算凋亡指数,于缺血前即刻和再灌注2 h时分别随机取4只大鼠处死取左心室,采用Western blot法测定Bcl-2及caspase-3的蛋白表达水平.结果 与S组相比,再灌注2 h时I/R组和SR组心肌梗死范围增大,心肌细胞凋亡指数升高,caspase-3蛋白表达上调,Sevo组Bcl-2蛋白表达上调,I/R组Bcl-2蛋白表达下调,Sevo组和SR组缺血前即刻Bcl-2蛋白表达上凋(P＜0.05);与I/R组相比,再灌注2 h时SR组心肌梗死范围缩小、心肌细胞凋亡指数降低,Sevo组和SR组Bcl-2蛋白表达上调,SR组caspase-3蛋白表达下调(P＜0.05);与缺血前即刻相比,I/R组和SR组再灌注2 h时Bcl-2蛋白表达下调,caspase-3蛋白表达上调(P＜0.05).结论 七氟烷预处理可通过抑制细胞凋亡减轻大鼠心肌缺血再灌注损伤.     

七氟醚预处理对大鼠肾缺血再灌注损伤的影响

目的 评价七氟醚预处理对大鼠肾缺血再灌注损伤的影响.方法 雄性SD大鼠24只,体重250～300 g,采用随机数字表法,将大鼠随机分为3组(n=8):假手术组(S组)、肾缺血再灌注组(I/R组)和七氟醚预处理组(SP组).I/R组和SP组采用切除右肾然后夹闭左侧肾动脉45 min再开放的方法 制备肾缺血再灌注模型.SP组吸入2.2%七氟醚1 h,停止吸入后10 min时进行肾缺血.于再灌注2 h时采集静脉血样,测定血清肌酐(Cr)、尿素氮(BUN)和胱抑素C(Cys C)的浓度,取肾组织,光镜下及透射电镜下观察病理学结果,并根据肾小管病变程度进行Paller评分.结果 与S组比较,I/R组血清Cr和BUN浓度差异无统计学意义(P＞0.05),血清Cys C浓度和Paller评分明显升高(P＜0.05);与I/R组比较,SP组血清Cys C浓度和Paller评分明显降低(P＜0.05).SP组肾组织损伤程度轻于I/R组.结论 七氟醚预处理可减轻大鼠肾缺血再灌注损伤.

Abstract：

Objective To investigate the effects of sevoflurane preconditioning on renal ischemia-reperfusion(I/R)injury in rats.Methods Twenty-four adult male SD rats weighing 250-300 g were randomly divided into 3 groups(n=8 each):sham operation group (group S);I/R group; sevoflurane preconditioning group (group SP). After the rats underwent right nephrectomy, renal I/R was produced by occlusion of left renal artery for 45 min followed by reperfusion in I/R and SP groups.In group SP, the rats inhaled 2.2% sevoflurane for 1 h, then the inhalation was stopped and renal ischemia was performed 10 min later. Venous blood samples were collected at 2 h of reperfusion to determine the concentrations of serum creatinine(Cr), urea nitrogen (BUN), cystatin C (Cys C) . The renal tissues were obtained for microscopic examination, and Paller's score was recorded. Results Compared with group S, there was no significant difference in the serum Cr and BUN concentrations (P＞0.05), while the serum Cys C concentration and Paller's score for acute renal tubular injury were significantly increased in group I/R(P＜0.05). The serum Cys C concentration and Paller's score were significantly lower in group SP than in group I/R(P＜0.05).I/R-induced renal injury was significantly reduced in group SP compared with group I/R. Conclusion Preconditioning with sevoflurane can provide significant protection against renal I/R injury.     

缺血预处理和缺血后处理对大鼠心肌缺血再灌注时炎性反应影响的比较

目的 比较缺血预处理和缺血后处理对大鼠心肌缺血再灌注时炎性反应的影响.方法 雄性SD大鼠40只,体重290～320 g,随机分为4组(n=10),缺血再灌注组(I/R组)、缺血预处理组(IPC组)和缺血后处理组(IPOC组)采用结扎左冠状动脉前降支30 min进行再灌注的方法制备心肌缺血再灌注模型,假手术组(S组)仅在左冠状动脉前降支下穿线.监测再灌注期间HR和MAP,并计算HR和MAP的乘积(心肌氧耗指数,RPP).分别于再灌注30和180 min时采集静脉血样,测定血清TNF-α、IL-6、高迁移率组蛋白1(HMGB1)和心肌肌钙蛋白I(cTnI)的浓度.采集完血样,取心肌组织,测定心肌梗死体积.结果 与S组比较,I/R组MAP和RPP降低,血清cTnI和炎性细胞因子浓度升高,心肌梗死体积增大(P＜0.05);与I/R组比较,IPC组MAP升高,IPOC组MAP和RPP均升高,两组血清cTnI和炎性细胞因子浓度降低,心肌梗死体积缩小(P＜0.05);与IPC组比较,IPOC组血清炎性细胞因子浓度升高,心肌梗死体积增大(P＜0.05).结论缺血预处理减轻大鼠心肌缺血再灌注时炎性反应的作用强于缺血后处理,从而使心肌保护效应较好.     

基于NOD2信号通路探讨NADPH抑制剂对肾脏缺血再灌注损伤的影响

目的基于抑制核苷酸寡聚化结构域蛋白-2(nucleotide-binding oligomerization domain-2,NOD2)信号通路,探讨NADPH抑制剂对大鼠肾脏缺血再灌注损伤(ischemia/reperfusion injury,IRI)的影响及作用机制。方法将雄性Wistar大鼠切除右肾,并随机分为4组:①肾脏缺血再灌注(I/R)组:给予等量生理盐水预处理后夹闭左肾动脉制备IRI模型;②I/R组+氯化二碘联苯(diphenylene iodonium,DPI)组:给予DPI预处理后夹闭左肾动脉制备IRI模型;③I/R组+4-羟基-3甲氧基苯乙酮(4-hydroxy-3-methoxyacetophenone,Apocynin)组:给予Apocynin预处理后夹闭左肾动脉制备肾脏IRI模型;④假手术(Sham)组:给予等量生理盐水处理后不予夹闭左肾动脉。试验结束24 h后收集各组大鼠血及肾组织标本,采用Western blot法分别对NOD2、核因子κB(nuclear factor-κB,NF-κB)、半胱氨酸蛋白酶(Caspase-1)的表达进行检测;采用实时定量PCR法对NOD2 mRNA的表达进行检测;采用HE染色法观察肾脏组织学改变;采用免疫组织化学法检测肾组织炎症因子IL-1β的表达。结果与Sham组比较,I/R组的大鼠肾组织NOD2、NF-κB蛋白、Caspase-1表达显著增加(P<0.05);NOD2 mRNA表达显著增加(P<0.05);I/R组肾脏病理表现为肾小管上皮细胞水肿、坏死,脱落于管腔,肾间质炎性细胞浸润,肾小管损伤评分明显增加(P<0.05)。与I/R组相比,I/R+Apocynin组和I/R+DPI组的NOD2、NF-κB蛋白、Caspase-1表达均显著减少(P<0.05),NOD2 mRNA表达显著减少(P<0.05),肾脏病理显示急性肾小管坏死程度减轻,肾小管损伤评分显著减低(P<0.05)。结论抑制氧化应激可通过阻断NOD2受体信号通路来减轻肾脏IRI过程。     

纤维蛋白肽Bβ15～42对大鼠缺血再灌注损伤肾脏局部炎性反应的影响

目的 观察纤维蛋白肽Bβ15～42(the fibrin-derived peptide Bβ15-42,FgBβ15～42肽)对大鼠肾脏缺血再灌注损伤(IRI)后肾脏局部炎性反应的影响并探讨其机制.方法 将SD大鼠随机分成假手术组(Sham组)、IRI组、阴性治疗组和FgBβ15 ～ 42肽治疗组.Sham组:分离肾动脉后关闭腹腔;IRI组:采用双侧肾动脉夹闭的方法制作肾脏IRI模型;阴性治疗组:于肾脏再灌注后立即尾静脉注射随机肽段3.6 mg/kg; FgBβ15～42肽治疗组:于肾脏再灌注后立即尾静脉注射FgBβ15～ 42肽3.6 mg/kg.后3组按照再灌注24h、48 h分为两个亚组,Sham组与各亚组均为8只大鼠.常规生化法检测肾功能;HE、PAS染色观察肾脏组织学改变;免疫组化、实时荧光定量PCR法及Western印迹检测肾组织白细胞介素1β(IL-1β)、细胞间黏附分子1(ICAM-1)的mRNA及蛋白表达.结果 与Sham组相比,IRI组的Scr和BUN水平均显著增加(均P ＜0.05),肾小管及间质病理损伤显著,以再灌注48 h更为明显;与IRI组相比,FgBβ15～ 42肽治疗组Scr和BUN显著下降(均P＜0.05),小管间质损伤程度明显减轻(P＜0.05).与Sham组相比,IRI组IL-1β和ICA M-1的mRNA和蛋白水平于再灌注24h显著上升,48 h稍微下降,但仍维持在较高水平;FgBβ15～ 42肽治疗组大鼠肾组织IL-1β和ICAM-1的表达于再灌注24h、48 h显著低于同时间点的IRI组(均P＜0.05),但仍明显高于Sham组.上述各指标在阴性治疗组和IRI组之间的表达差异无统计学意义.结论 FgBβ15～42肽对肾脏IRI具有保护作用,其作用机制可能与其减少炎性因子IL-1β、黏附分子ICAM-1的表达有关.     

丙泊酚预处理对大鼠心肌缺血/再灌注损伤中自噬潮的影响

目的 研究丙泊酚预处理对大鼠心肌缺血/再灌注(ischemia/reperfusion,I/R)期间自噬潮的影响及其机制. 方法 采用大鼠在体心肌I/R损伤模型,将90只雄性SD大鼠按照随机数字表法分为5组(每组18只):①假手术组(Sham组),只穿线不结扎;②I/R组;③丙泊酚预处理组(P+I/R组);④Ⅰ型磷脂酰肌醇3-激酶(phosphatidylinositol 3-kinase,PI3K)抑制剂A66预处理组(A+I/R组);⑤丙泊酚+A66预处理组(P+A+I/R组).采用结扎冠状动脉左前降支的方法制备心肌I/R模型.除Sham组外,其余各组均缺血30 min,再灌注120 min.缺血前15 min,P+I/R组通过股静脉输注丙泊酚15 mg·kg1·h1;A+I/R组缺血前1h腹腔注射A66溶液10 mg/kg;P+A+I/R组在缺血前1h腹腔注射A66溶液10 mg/kg,缺血前15 min再通过股静脉输注丙泊酚15 mg·kg1·h-1.模型制备后取心肌,2,3,5-氯化三苯基四氮唑(2,3,5-triphenyhetrazolium chloride,TTC)法染色并计算梗死面积百分比,酶标法测定乳酸脱氢酶(lactate dehydwgenase,LDH)活性,Western bolt法检测微管相关蛋白1轻链3(microtubule-associated protein 1 light chain 3,LC3)-Ⅱ、P62蛋白的表达量,电子显微镜定性观察自噬体、自噬溶酶体的数量.结果 与I/R组比较,P+I/R组与P+A+I/R组梗死面积[(50.1±-3.9)％比(26.5±1.3)％、(42.6±1.9)％]显著减小(P＜0.05),血清LDH活性降低,LC3-Ⅱ表达水平降低,P62表达水平升高(P＜0.05),自噬体、自噬溶酶体明显减少.与P+I/R组比较,P+A+I/R组梗死面积[(26.5±1.3)％比(42.6±1.9)％]显著增加(P＜0.05),血清LDH活性升高,LC3-Ⅱ表达水平升高,P62表达水平降低(P＜0.05),自噬体、自噬溶酶体增加. 结论 丙泊酚预处理激活PI3K/蛋白激酶B(pmtein kinase B,Akt)通路,抑制I/R心肌中自噬潮进行,对大鼠心肌I/R损伤产生保护作用.     

TAK1信号通路在高糖诱导骨髓来源巨噬细胞激活中的作用

Objective To investigate the role of transforming growth factor-β activated kinase-1 (TAK1) signaling pathway in the activation of bone marrow derived macrophages (BMDM) induced by high glucose. Methods Purity of mouse BMDM was detected by flow cytometry. The mice macrophages cultured in vitro were stimulated by high glucose and treated with TAK1 specific inhibitor 5Z-7-oxozeaenol. Cells were divided into normal control group (RPMI 1640), osmolality control group (25 mmol/L mannitol), high glucose group (33 mmol/L D-glucose) and inhibitor group (33 mmol/L D-glucose+300 nmol/L 5Z-7-oxozeaenol). Immunocytochemistry and flow cytometry were used to detect macrophage subtype. The expression of monocyte chemotactic protein-1 (MCP-1) and tumor necrosis Factor-α (TNF-α) mRNA were determined by real time PCR. Expressions of p-TAK1, TAK1 binding protein (TAB1), p-JNK, p-p38 MAPK and NF-κB p65 proteins were analyzed by Western blotting. Results The purity of BMDM was about 99.36%. Compared with normal control group, high glucose group had increased percentage of M1 macrophages, increased expression of MCP-1 and TNF-α mRNA (all P＜0.05). Moreover, p-TAK1, TAB1, p-JNK, p-p38 MAPK and NF-κB p65 proteins expression also increased significantly in high glucose group (all P＜0.05). After treatment with inhibitor 5Z-7-oxozeaenol, the effects induced by high glucose were inhibited (P＜0.05). Conclusions High glucose can induce M1 macrophage activation and expression of inflammatory cytokine of BMDM, which can be inhibited 5Z-7-oxozeaenol through inhibiting TAK1/MAPK and TAK1/NF-κB pathway.     

右美托咪定预处理对大鼠心肌缺血/再灌注损伤时心肌组织高迁移率族蛋白B1的影响

目的 探讨右美托咪定(dexmedetomidine,Dex)预处理对大鼠心肌缺血/再灌注损伤(myocardial ischemia/reperfusion injury,MFRI)时心肌组织高迁移率族蛋白B1(high mobility group box-1 protein,HMGB1)表达量的影响. 方法 健康雄性SD大鼠52只,体重250～300 g,按随机数字表法分为4组(每组13只):假手术组(S组)、缺血/再灌注(ischemia/reperfusion,I/R)组(I/R组)、Dex+I/R组(D组)、Dex+育亨宾+I/R组(D/Y组).结扎左冠状动脉前降支30 min,恢复灌注120 min制备MI/RI模型.再灌120 min时采血ELISA法测定血清中IL-6、TNF-α浓度,随后处死大鼠摘取心脏,用2,3,5-氯化三苯基四氮唑(2,3,5-triphenyltetrazolium chloride,TTC)染色法测定心肌梗死面积,Western blot法测定心肌组织HMGB1蛋白的表达量. 结果 与S组比较,I/R组血清中IL-6、TNF-α含量[(336±41)、(636±25) ng/L]均显著增高(P＜0.05),心肌梗死面积明显增大(P＜0.05),心肌组织HMGB1蛋白表达量明显升高(P＜0.05);与豫组比较,D组血清中IL-6、TNF-α含量[(153±10)、(233±9) ng/L]均明显降低(P＜0.05),心肌梗死面积明显减少(P＜0.05),心肌组织HMGB1蛋白表达量显著降低(P＜0.05);与D组比较,D/Y组血清中IL-6、TNF-α含量[(230±20)、(386±32) ng/L]均显著增高(P＜0.05),心肌梗死面积明显增大(P＜0.05),心肌组织HMGB1蛋白表达量明显升高(P＜0.05). 结论 Dex预处理减轻MI/RI心肌组织HMGB1的表达量,减轻I/R损伤的炎症反应.Dex通过α2受体发挥保护作用.     

Relationship of angiotensin II type 1 receptor autoantibody and renal cell apoptosis induced by caspase-12 in diabetic nephropathy rats

Objective To study the relationship of angiotensin II type 1 receptor (AT1R) autoantibody (AT1-AA) and renal cell apoptosis induced by caspase-12 in diabetic nephropathy (DN) rats. Methods High-sucrose and high-fat diet and intraperitoneal injection of streptozotocin (35 mg/kg) were utilized to establish DN rat model. Serum AT1-AA was detected by enzyme-linked immunosorbent assay (ELISA) and renal cell apoptosis was detected by TUNEL staining. Furthermore, the mRNA levels of the endoplasmic reticulum stress (ERS) chaperone protein glucose regulated protein 78 (GRP78) and ERS-associated apoptosis protein caspase-12 were measured by real-time quantitative PCR. Additionally, the levels of GRP78 and caspase-12 protein were measured by Western blotting. Results The renal cell apoptosis rate in DN group was increased significantly (P＜0.01), and the renal cells apoptosis rate in AT1-AA positive DN group was higher than that in AT1-AA negative DN group [(20.05±1.71)% vs (13.24±4.93)%, P＜0.01]. The mRNA expressions of GRP78 and caspase-12 in DN group, in comparison to NC group, were increased significantly (P＜0.01), as well as the proteins (P＜0.01). And the expression of these mRNA and proteins had significant increment in AT1-AA positive DN rats when compared with AT1-AA negative DN rats (P＜0.05). Conclusions AT1-AA can induce ERS in the renal tissue of DN rats, and promote renal cell apoptosis likely via the modulation of caspase-12 signaling pathway.     

Apocynin和DPI通过抑制NOD1信号通路在缺血性AKI中的保护作用

目的NOD样受体可促发炎症反应,夹竹桃麻素(apocynin)和二苯基碘鎓(DPI)均为氧化酶抑制剂。本研究观察在缺血性急性肾损伤中抑制氧化应激产生是否能通过NOD1信号通路减轻肾间质炎症反应与细胞凋亡。 方法将雄性Wistar大鼠随机分为4组：假手术(Sham)组、肾脏缺血再灌注(I/R)组、I/R ＋夹竹桃麻素(apocynin)组、I/R ＋二苯基碘鎓(DPI)组。通过Western印记法分别对肾组织核苷酸结合寡聚域样受体1(NOD1)、半胱天冬酶(caspase-1)及细胞核因子-κB(NF-κB)蛋白的表达进行检测;实时定量PCR法对NOD1mRNA的表达进行检测;HE染色法观察肾脏组织学改变;免疫组织化学法检测肾组织肿瘤坏死因子(TNF-ɑ)的表达;TUNEL法检测肾组织细胞凋亡。采用SPSS 22.0统计软包对实验数据进行统计学处理。 结果与Sham组比较,I/R组大鼠肾组织NOD1、caspase-1、NF-κB、TNF-ɑ蛋白表达增加(t＝16.81, t＝ 7.28, t＝ 11.08, t＝ 10.11;P<0.05);NOD1mRNA表达增加(t＝－7.93, P<0.05);HE染色表现为急性肾小管坏死,肾小管损伤评分明显增加(t＝－11.0, P<0.05);TUNEL染色显示缺血区凋亡细胞数目增加(t＝－18.38, P<0.05)。与I/R组比较,I/R＋ apocynin组的NOD1、caspase-1、NF-κB、TNF-ɑ蛋白表达减少(t＝－10.9, t＝－7.6, t＝－4.9, t＝－9.7;P<0.05);NOD1mRNA表达减少(t＝8.49, P<0.05);HE染色后者较前者急性肾小管坏死减轻,肾小管损伤评分减低(t＝－12, P<0.05);TUNEL染色显示缺血区凋亡细胞数目减少(t＝－11.3, P<0.05)。与I/R组比较,I/R＋DPI组的NOD1、caspase-1、NF-κB、TNF-ɑ蛋白表达减少(t＝－11.4, t＝－6.8, t＝－5.4, t＝－10.6, P<0.05);NOD1mRNA表达减少(t＝7.5, P<0.05);HE染色后者较前者急性肾小管坏死减轻,肾小管损伤评分减低(t＝－11, P<0.05);TUNEL染色显示缺血区凋亡细胞数目减少(t＝－10.8, P<0.05)。 结论抑制氧化应激可阻断NOD1样受体依赖的炎症途径与细胞凋亡,从而减轻肾缺血再灌注损伤。     

Administration of interleukin-1 receptor antagonist ameliorates renal ischemia-reperfusion injury.

Interleukin (IL)-1 is a major contributor to inflammation and apoptosis during ischemia/reperfusion (I/R) injury. Its deleterious effects are primarily mediated by the activation of nuclear factor-kappaB (NF-kappaB). Receptor-binding and signaling of IL-1 can be blocked by the IL-1 receptor antagonist (IL-1ra). The aim of our study was to characterize effects and mechanisms of IL-1ra administration on inflammation, apoptosis, and infiltration in renal I/R injury. Renal ischemia was induced in Lewis rats by clamping of the left renal artery for 45 min. Kidneys were removed for histological and molecular analysis 24 h or 5 days after reperfusion. IL-1ra ameliorated I/R induced renal injury and inflammation. Furthermore, the number of apoptotic tubular cells was lower in IL-1ra-treated animals 24 h after ischemia, which was paralleled by a Bax/Bcl-2 mRNA ratio towards anti-apoptotic effects. IL-1ra reduced the expression of monocyte chemoattractant protein-1 (MCP-1) mRNA at 24 h and 5 days and that of intracellular adhesion molecule-1 (ICAM-1) expression at 24 h in the ischemic reperfused kidneys. Our results indicate that IL-1ra treatment ameliorates renal I/R injury and this protective effect might be mediated by reduced induction of NF-kappaB mediated MCP-1, ICAM-1, and a decreased ratio between Bax and Bcl-2 mRNA expression.     

异丙酚联合机体低氧预处理对大鼠肺缺血再灌注损伤的影响

目的 探讨异丙酚联合机体低氧预处理对大鼠肺缺血再灌注损伤的影响.方法 健康雄性SD大鼠90只,体重250～320 g,随机分为5组(n=18):假手术组(S组)、肺缺血再灌注组(IR组)、异丙酚组(P组)、机体低氧预处理组(WBHP组)和异丙酚联合机体低氧预处理组(PW组).IR组采用阻断左肺门45 min后再灌注的方法制备大鼠单肺缺血再灌注损伤模型,P组夹闭左肺门前30 min持续静脉输注异丙酚30 mg·kg-1·h-1;WBHP组夹闭左肺门前先行机体低氧预处理;PW组夹闭左肺门前30 min持续静脉输注异丙酚30 mg·kg-1·h-1和机体低氧预处理.分别于再灌注0.5、1、4 h时测定肺组织TNF-α、IL-1、IL-6和MDA的含量,SOD活性,计算肺湿干重比(W/D).结果 与S组比较,IR组、P组、WBHP组和PW组T1～3时肺组织TNF-α、IL-1、IL-6和MDA的含量及W/D升高,SOD活性降低(P＜0.05);与IR组比较,P组、WBHP组和PW组T1～3时TNF-α、IL-1、IL-6和MDA的含量及W/D降低,SOD活升高(P＜0.05);与P组和WBHP组比较,PW组T2,3时TNF-α和IL-6的含量及W/D降低,SOD活性升高,T3时IL-1和MDA的含量降低(P＜0.05).P组与WBHP组各指标差异无统计学意义(P＞0.05).结论 异丙酚联合机体低氧预处理减轻肺缺血再灌注损伤的作用较单独应用时强,可能与联合应用时抑制炎性反应的作用增强和抗氧化能力提高有关.     

缺血预处理通过抑制炎症反应保护心肌细胞的研究

目的 探讨缺血预处理(IP)对心肌细胞的保护作用及其机制.方法 2004年4月至2004年12月期间在我科行瓣膜置换手术的患者36例,根据是否采取缺血预处理分为预处理组(20例)和对照组(16例),比较两组炎症因子白细胞介素(IL)-8、IL-10、肿瘤坏死因子-α(TNF-α)和心肌细胞转录因子NF.KB p65蛋白的变化情况,分析IP对机体炎症反应的影响.结果 两组患者细胞因子IL-8、IL-10、TNF-α均在主动脉开放6 h时达到高峰,术后5 d均恢复到术前水平.预处理组开放后6 h、术后1 d、术后2 d IL-8和TNF-a水平明显低于对照组(P<0.05),IL-10水平显著高于对照组(P<0.05).复灌后两组心肌细胞中NF-KB p65蛋白表达明显增多,预处理组表达量明显低于对照组(P<0.05),与术后1 d TNF-α呈正相关.结论 缺血预处理可能通过降低机体的炎症反应途径达到心肌细胞保护的效果.     

七氟醚延迟预处理对大鼠缺血再灌注心肌ARC表达的影响

目的 评价七氟醚延迟预处理对大鼠缺血再灌注心肌带有Caspase富集功能域的凋亡抑制蛋白(ARC)表达的影响.方法 成年雄性SD大鼠64只,体重270～350 g,采用随机数字表法,将其随机分为4组(n=16):假手术组(S组)、心肌缺血再灌注组(I/R组)、七氟醚+假手术组(S-S组)和七氟醚延迟预处理+心肌缺血再灌注组(S-VR组).S-S组和S-I/R组分别吸入33%氧气和2.5%七氟醚2 h,停止吸入后24 h行假手术或心肌缺血再灌注;I/R组和S-I/R组采用结扎左冠状动脉前降支30 min,再灌注2 h的方法制备心肌缺血再灌注模型.于再灌注2 h时处死8只大鼠,取左心室组织,测定心肌梗死范围及细胞凋亡情况,计算凋亡指数,于缺血前即刻及再灌注2 h时各处死4只大鼠,取左心室组织,测定ARC及Caspase-8的表达水平.结果 与S组比较,I/R组和S-I/R组心肌梗死范围及细胞凋亡指数升高,缺血前即刻S-S组和S-I/R组ARC表达上调,再灌注2 h时I/R组Caspese-8、表达上调(P＜0.05);与I/R组比较,S-I/R组心肌梗死范围和细胞凋亡指数降低,再灌注2 h时S-S组和S-I/R组ARC表达上调,Caspase-8表达下调(P＜0.05).结论 七氟醚延迟预处理可上调心肌ARC表达,减少细胞凋亡的发生,从而减轻大鼠心肌缺血再灌注损伤.

Abstract：

Objective To investigate the effects of sevoflurane delayed preconditioning on caspase recruitment domain (ARC) expression during myocardial ischemia-reperfusion (I/R) in rats. Methods Sixty-four adult male SD rats weighing 270-350 g were randomly divided into 4 groups ( n = 16 each): sham operation (group S); myocardial I/R group; sevoflurane + sham operation group (group S-S) and sevoflurane delayed preconditioning + myocardial I/R group (group S-I/R) . Myocardial I/R was induced by occlusion of anterior descending branch of left coronary artery for 30 min followed by 2 h of reperfusion in groups I/R and S-I/R. Group S-S inhaled 33% oxygen for 2 h, and sham operation was performed 24 h later. Group S-I/R inhaled 2.5% sevoflurane for 2 h, and then myocardial I/R was induced 24 h later. Eight animals were sacrificed at the end of 2 h reperfusion in each group and the hearts removed for determination of myocardial infarct size (IS) as a percentage of area at risk (AAR) by triphenyl tetrazolium chloride staining (IS/AAR) . Myocardial apoptosis was detected using TUNEL and apoptosis index was calculated. Another 4 animals were sacrificed immediately before ischemia and at the end of 2 h reperfusion to determine the expression of ARC and Caspase-8 in myocardium by Western blot. Results Compared with group S, the infarct size and apoptosis index were significantly increased in groups I/R and S-I/R, and ARC expression was up-regulated immediately before ischemia in groups S-S and S-I/R, and Caspase-8 expression was up-regulated at 2 h of reperfusion in group I/R ( P ＜ 0.05) . Compared with group I/R, the infarct size and apoptosis index were significantly decreased in group S-I/R, and ARC expression was up-regulated, while Caspase-8 expression was down-regulated at 2 h of reperfusion in groups S-S and S-I/R ( P ＜ 0.05) . Conclusion Sevoflurane delayed preconditioning can attenuate myocardial I/R injury through up-regulating the ARC expression and decreasing the myocardial apoptosis.     

Renoprotective effect of transforming growth factor beta activator kinase 1 inhibitor in diabetic db/db mice and its mechanism

Objective To investigate the renoprotective effect of transforming growth factor beta activator kinase 1 (TAK1) inhibitor 5Z-7-oxozeaenol (OZ) in diabetic db/db mice and the mechanism. Methods Twenty-four male db/db mice were randomly divided into two groups: db/db mice (db/db, n=12) and db/db mice with 5Z-7-oxozeaenol treatment (db/db+OZ, n=12). Another group of wild type mice (n=12) was held as the control group. OZ 2 mg/kg was administrated by intraperitoneal injection every other day. At week 8 and 12 after 5Z-7-oxozeaenol treatment, blood glucose (BG), body weight (BW), kidney weight (KW) and urinary albumin excretion rate (UAER) were evaluated. Kidney pathological lesions were detected by light and electron microscopy. NF-κB p65, monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) were detected by immunohistochemistry. Western blotting was used to detect p-TAK1, TAB1, p-p38MAPK and IL-1β expression, while ICAM-1 and MCP-1 mRNA levels were evaluated by real-time PCR. Results Compared with control group, the levels of BG, BW, KW and UAER were higher (P＜0.01) in db/db mice group, while BW, KW and UAER levels were significantly decreased in db/db+OZ group compared with that in db/db mice group (P＜0.05). In week 8 and 12 db/db mice, glomerular volume and extracellular matrix were increased, while pathological lesions in kidney tissue were positively improved by TAK1 inhibitor. Immunohistochemistry showed that NF-κB p65, MCP-1 and TNF-α expression levels were apparently increased in db/db mice group compared with that in control group (P＜0.05) and were significantly inhibited by TAK1 inhibitor (P＜0.05). Western blotting showed that p-TAK1, TAB1, p-p38MAPK and IL-1β expression levels were higher in db/db mice group than that in control group (P＜0.05) and lower in db/db+OZ group than that in db/db mice group (P＜0.05). Moreover, real-time PCR showed that the expressions of ICAM-1 and MCP-1 mRNA were higher in db/db mice group than that in control group and lower in db/db+OZ group than that in db/db mice group (P＜0.05). Conclusions TAK1 Inhibitor can down-regulate MAPK and NF-κB pathway to restrain the reaction of inflammation and alleviate kidney injury in diabetic db/db mice.