低氧诱导因子在肾炎大鼠肾小管间质中的表达及氯沙坦的保护作用研究

目的:观察低氧诱导因子在肾炎大鼠肾小管间质中表达的变化以及氯沙坦对肾炎的保护作用。方法:雄性Wistar大鼠32只,随机分成假手术组、肾炎模型组、氯沙坦小剂量组、氯沙坦大剂量组各8只,假手术组不做肾脏切除,其他组在右肾切除后尾静脉注射标记抗体。给药组则按量分别灌胃给药,8周时处死。结果:大剂量给药组的血肌酐(Scr)、收缩压和24 h尿蛋白量较模型组显著降低,且小剂量给药组的血肌酐(Scr)和24h尿蛋白量较模型组也显著降低。小剂量组和大剂量组大鼠的肾间质面积较肾炎模型组均显著降低。HIF-1αmRNA大量表达于肾小管上皮细胞胞质和间质细胞胞质,且与模型组比较,小剂量给药组的HIF-1αmRNA显著降低;大剂量给药组较肾炎模型组HIF-1αmRNA的含量也显著降低。结论:氯沙坦可能可以通过影响低氧诱导因子(HIF-1α)的表达发挥对肾脏的保护作用。     

低氧诱导因子在肾炎大鼠肾小管间质中的表达及氯沙坦的保护作用研究

目的：观察低氧诱导因子在肾炎大鼠肾小管间质中表达的变化以及氯沙坦对肾炎的保护作用。方法：雄性Wistar 大鼠32只,随机分成假手术组、肾炎模型组、氯沙坦小剂量组、氯沙坦大剂量组各8 只,假手术组不做肾脏切除,其他组在右肾切除后尾静脉注射标记抗体。给药组则按量分别灌胃给药,8 周时处死。结果：大剂量给药组的血肌酐（Scr）、收缩压和24 h尿蛋白量较模型组显著降低,且小剂量给药组的血肌酐（Scr）和24h 尿蛋白量较模型组也显著降低。小剂量组和大剂量组大鼠的肾间质面积较肾炎模型组均显著降低。HIF-1αmRNA 大量表达于肾小管上皮细胞胞质和间质细胞胞质,且与模型组比较,小剂量给药组的HIF-1αmRNA显著降低;大剂量给药组较肾炎模型组HIF-1琢mRNA 的含量也显著降低。结论：氯沙坦可能可以通过影响低氧诱导因子（HIF-1α）的表达发挥对肾脏的保护作用。     

蝉花虫草提取物N~6-(2-羟乙基)腺苷对小鼠肾脏缺血再灌注损伤的保护作用

研究蝉花虫草提取物N~6-(2-羟乙基)腺苷[N~6-(2-hydroxyethyl)-adenosine,HEA]对小鼠肾脏缺血再灌注损伤(ischemia reperfusion,IR)的影响。选择20–25g雄性C57BL/6小鼠,随机分成5组。假手术组小鼠仅接受腹中线开腹、游离双侧肾蒂及缝合腹部操作;IR组小鼠制成肾脏IR模型,不给药;HEA低剂量组、HEA中剂量组、HEA高剂量组分别在建立肾脏缺血再灌注模型前15min腹腔注射HEA(2.5mg/kg、5mg/kg和7.5mg/kg)。再灌注24h后检测各组肾功能指标血清肌酐(serum creatinine,Scr)和尿素氮(blood urea nitrogen,BUN)水平。苏木精-伊红染色后用光学显微镜观察肾脏组织形态学改变。电镜和TUNEL分析法观察肾小管上皮细胞凋亡状况。实时荧光定量RT-PCR检测细胞间粘附分子-1(intercellular adhesion molecule-1,ICAM-1)、白细胞介素(interleukin-1β,IL-1β)和肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)等基因的m RNA的表达情况。结果显示,与假手术组比较,IR组BUN和Scr水平明显升高(P0.01,P0.05);肾脏病理表现为上皮细胞碎片和管型,且最为严重;与IR组比较,HEA 7.5mg/kg组血清BUN和Scr水平显著降低(P0.05);HEA 5mg/kg组和HEA 7.5mg/kg组肾损伤情况明显改善(P0.05,P0.01);电镜观察可知HEA 7.5mg/kg组明显改善肾小管上皮细胞的损伤程度,并且保护线粒体和细胞核膜的完整性。原位末端标记法[terminal dexynucleotidyl transferase(Td T)-mediated d UTP nick end labeling,TUNEL]显示HEA治疗组凋亡细胞数量明显低于IR组(P0.01)。HEA治疗组ICAM-1、IL-1β和TNF-αm RNA的水平均低于IR组(P0.01)。所以预处理HEA 7.5mg/kg对肾脏缺血再灌注有保护作用。     

低氧及低氧预处理时心肌细胞HIF-1α与凋亡相关蛋白表达的变化

目的:观察低氧时心肌细胞HIF-1α表达变化与凋亡相关蛋白表达关系.方法:采用体外心肌细胞培养的方法,将原代培养4～6 d的大鼠乳鼠心肌细胞随机分为对照组、低氧组与低氧预处理组.低氧预处理组在低氧培养箱中通入1%O2、5%CO2、94%N2的低氧混合气体,每天低氧12 h,低氧5 d,第6 d与急性低氧组一同放入0%O2、5%CO2、95%N2的低氧培养箱中进行低氧暴露.低氧48 h后,通过Western blot方法分别检测心肌细胞中HIF-1α、Bcl-2、P53及Bax的表达变化.结果:常氧时细胞不表达HIF-1α,低氧可增加HIF-1的表达,低氧预处理后,能降低HIF-1α的表达.低氧时,Bax的表达变化大致与此相同.p53在低氧时的变化也与其相同,但低氧预处理后似乎没有明显的改变.Bcl-2在低氧时表达下降,低氧预处理后可增加其表达.结论:HIF-1α的表达可协同Bcl-2家族凋亡相关蛋白的表达,在低氧导致的心肌细胞凋亡中发挥重要作用.     

低氧诱导因子-1α对SH-SY5Y细胞兴奋性毒性损伤的调节作用

探讨低氧诱导因子-1α(hypoxia inducible factor-1α,HIF-1α)在喹啉酸诱导人神经母细胞瘤SH-SY5Y细胞损伤中的作用。将体外培养的人神经母细胞瘤SH-SY5Y细胞分为对照组、喹啉酸低、中、高剂量组及HIF-1α抑制剂二甲氧基雌二醇(2-methoxyestradiol,2ME2)预处理喹啉酸高剂量组,采用噻唑蓝还原法和乳酸脱氢酶漏出率检测法测定细胞损伤程度,Hoechst 33342单荧光染色法观察细胞凋亡,免疫荧光染色法检测HIF-1α在细胞内的表达,免疫印迹法检测细胞HIF-1α、蛋白激酶B(protein kinase B,Akt)、磷酸化Akt(p-Akt)、Bcl-2和Bax的表达。结果显示,喹啉酸可剂量、时间依赖性地诱导SH-SY5Y细胞损伤,导致细胞凋亡。同时,喹啉酸可使SH-SY5Y细胞HIF-1α表达上调并发生核转位、p-Akt表达增加及Bax/Bcl-2表达比例增加,而2ME2可抑制喹啉酸诱导的SH-SY5Y细胞损伤及降低HIF-1α、p-Akt和Bax/Bcl-2的表达。由此说明,HIF-1α/Akt通路介导了喹啉酸诱导SHSY5Y的细胞凋亡。HIF-1α抑制剂(2ME2)能够减轻喹啉酸致SH-SY5Y细胞损伤程度,减少细胞凋亡。     

低氧后处理诱导的低氧诱导因子-1α表达上调减轻H9c2心肌细胞低氧/复氧损伤北大核心CSCD

本文旨在探讨低氧后处理(hypoxic postconditioning)对低氧/复氧(hypoxia/reoxygenation,H/R)所致的心肌细胞损伤以及低氧诱导因子-1α(hypoxia inducible factor-1α,HIF-1α)表达的影响,并分析二者之间可能的关系。利用H9c2心肌细胞株建立低氧/复氧和低氧后处理模型,通过测定细胞存活率、细胞培养液中乳酸脱氢酶(lactate dehydrogenase,LDH)的活性及caspase-3活性来观察低氧/复氧造成的H9c2细胞的损伤,用Westernblot检测H9c2细胞内HIF-1α的蛋白水平,用real-timePCR检测细胞内HIF-1α的mRNA水平。结果显示,低氧后处理提高了低氧/复氧H9c2细胞的存活率,降低了LDH及caspase-3活性。同时,低氧后处理增加了H9c2细胞内HIF-1α的蛋白水平。预先利用HIF-1α脯氨酸羟化酶抑制剂DMOG上调HIF-1α的蛋白水平后,由低氧/复氧导致的H9c2细胞的损伤明显减轻,其效应与低氧后处理完全一致。对H9c2细胞内HIF-1α蛋白水平与细胞存活率进行相关性分析,结果显示二者呈显著正相关(r=0.743,P<0.01);而运用siRNA方法抑制细胞内HIF-1α基因表达后,显著削弱了低氧后处理减轻低氧/复氧细胞损伤的效应。以上结果提示,HIF-1α表达上调是低氧后处理减轻细胞低氧/复氧损伤的机制之一。     

缺氧对大鼠脑微血管内皮细胞增殖和凋亡的影响及其机制研究

目的:探讨缺氧对大鼠脑微血管内皮细胞增殖和凋亡的影响及其可能的分子机制。方法:从2周龄的SD大鼠中提取脑微血管内皮细胞。体外模拟脑缺氧微环境,将体外培养的脑微血管内皮细胞分别置于常氧(21%O_2)和低氧环境(1%O_2)下处理6、12和24小时,采用四甲基偶氮唑盐(MTT)法观测不同时间点细胞增殖能力的变化;用AnnexinV-FITC/PI双标流式细胞术观察不同时间点细胞凋亡情况;Real time-PCR和Western blot法检测细胞中(Hypoxia-inducible factor-1α) HIF-1αm RNA和蛋白的表达。进一步使用HIF-1αsi RNA靶向沉默HIF-1α基因,再检测低氧环境下HIF-1αm RNA和蛋白表达、细胞增殖以及凋亡水平的变化。结果:随着低氧处理时间的延长,大鼠脑微血管内皮细胞的增殖能力被显著抑制,同时凋亡水平显著增加,HIF-1αm RNA和蛋白表达水平显著升高。使用HIF-1αsi RNA特异性阻断HIF-1α表达后,低氧环境下HIF-1αm RNA和蛋白表达明显降低,同时细胞活性增加,细胞凋亡率显著下降。结论:缺氧微环境能够通过上调HIF-1α的表达抑制大鼠脑微血管内皮细胞增殖并促进其凋亡。     

低氧处理不同时间对人肺腺癌A549细胞增殖的影响 及相应缺氧模型探讨*

目的:观察低氧处理不同时间对人肺腺癌A549细胞增殖的影响,探讨合理的人肺腺癌细胞株A549体外模拟缺氧时间。方法:将人肺腺癌细胞A549细胞株在低氧环境下分别培养12 h、24 h、48 h、72 h,设置常氧对照组,通过CCK8法测定A549细胞存活率,RT-PCR和免疫印迹分别检测细胞缺氧诱导因子-1α(hypoxia-inducible factor-1α, HIF-1α)和血管内皮生长因子(vascularendothelial growth factor, VEGF)mRNA及蛋白的表达。结果:低氧24 h组A549细胞存活率最高,低氧48 h、72 h组A549细胞存活率呈时间依赖性明显下降(P0.001)。自低氧12 h起,A549细胞HIF-1αmRNA和VEGFmRNA的表达开始随低氧时间延长而显著增加(P均0.001);HIF-1α和VEGF蛋白表达自24 h开始随低氧时间延长而显著增加(P均0.001)。结论:低氧诱导的A549细胞存活率呈时间依赖性降低,而HIF-1α、VEGF表达呈时间依赖性增高,人肺癌细胞株A549缺氧模型最适时间为24 h。     

TLR7在1型糖尿病大鼠肾缺血再灌注损伤中的作用研究

目的:探讨Toll样受体7(TLR7)介导的My D88/NF-κB信号通路在1型糖尿病大鼠肾缺血再灌注损伤中的作用。方法:雄性SD大鼠随机分为3组(n=6),糖尿病假手术组(DS),糖尿病缺血再灌注组(DIR),糖尿病缺血再灌注+氯喹预处理组(DIR+CQ)。采用腹腔注射链尿佐菌素65 mg/kg建立糖尿病模型,TLR7抑制剂氯喹预处理于糖尿病模型成功后第3周0.5%氯喹40 mg/kg进行腹腔注射,连续给药7天。于第四周采用双侧肾蒂夹闭25 min,再灌注48 h建立肾缺血再灌注损伤模型。取大鼠肾脏HE染色观察大鼠病理学结果,血标本测定血尿素氮(BUN)和血肌酐(Scr)水平,ELISA法检测白细胞介素6(IL-6)和肿瘤坏死因子-α(TNF-α),TUNEL法检测细胞凋亡,Western blot检测TLR7,My D88和NF-κB蛋白表达。结果:与DS组相比,DIR组肾小管肿胀,间质水肿,刷状缘丢失,空泡变性坏死,Paller评分升高(P0.01)。与DIR组相比,氯喹预处理可以改善肾损伤(P=0.017);与DS组相比,DIR组BUN,Scr,IL-6,TNF-α,细胞调亡指数(Apoptosis%),TLR7,My D88,NF-κB增高(P0.05);与DIR组相比,DIR+CQ组BUN,Scr,IL-6,TNF-α,Apoptosis%,TLR7,My D88,NF-κB降低(P0.05)。结论:TLR7介导的My D88/NF-κB信号通路参与糖尿病肾缺血再灌注损伤,氯喹通过抑制TLR7表达,阻断My D88/NF-κB信号通路,降低炎症反应,从而减轻1型糖尿病大鼠肾缺血再灌注损伤。     

缺氧诱导因子-1α在缺氧预处理预防心肌细胞损伤中的作用

本工作旨在研究缺氧预处理(hypoxic preconditioning,HPC)对于心肌细胞外信号调节激酶(extracellular signal-regulated proteinkinases,ERK)活性、缺氧诱导因子-1α(hypoxia-inducible factor-1α,HIF-1α)表达的影响,及其在缺氧复氧诱导心肌细胞损伤中的作用。通过在培养的SD乳鼠心肌细胞缺氧／复氧(H／R)模型上,观察HPC对于24h后H／R诱导心肌细胞损伤的影响,以台盼蓝排斥实验检测心肌细胞存活率、以TUNEL法检测细胞凋亡、并用荧光素染料Hoechst33258测定心肌细胞凋亡率：制备心肌细胞蛋白提取物,以磷酸化的ERK1／2抗体测定ERK1／2活性,以抗HIF-1α抗体检测HIF-1α的表达,并观察ERKs的上游激酶(MEK1／2)抑制剂PD98059对于HPC诱导的ERKs磷酸化、HIF-1α表达以及心肌细胞保护作用的影响,并分析细胞损伤与ERK1／2活性、HIF-1α表达量之间的相互关系。结果 显示缺氧复氧造成心肌细胞损伤,HPC可以增加心肌细胞H／R后存活率,降低凋亡率,并激活ERKll2,诱导HIF-1α表达：细胞凋亡与ERKs活性、HIF-1α表达量之间存在负相关,即ERKs活化、HIF-1α表达与预防细胞损伤有关：而ERKs活性与HIF-1α表达量之间存在正相关,ERKs的上游激酶MEK抑制剂PD98059可以消除HPC诱导的ERKs磷酸化、HIF-1α表达和心肌细胞保护作用。由此得出的结论是HPC可以提高乳鼠心肌细胞对于H／R的耐受性,其机制涉及ERKs介导的HIF-1α表达。     

人特异性CHRFAM7A基因抑制小鼠肾缺血再灌注损伤炎症反应

本研究探讨人特异性CHRFAM7A基因抑制小鼠肾缺血再灌注损伤早期炎症作用及其机制。 12只野生型（wild type, WT）C57BL/6成年雄性小鼠随机分为2组：野生型假手术组（WT Sham）和野生型肾缺血再灌注损伤（WT RIRI）组。12只性别、年龄匹配的 CHRFAM7A转基因（transgenic mice, GT）小鼠也随机分组为：转基因型假手术组（GT Sham）和转基因型肾缺血再灌注损伤（GT RIRI）组,每组各6只。除WT 和GT假手术组仅行剖腹手术外,所有小鼠均夹闭双侧肾蒂40 min,再灌注24 h后,留取各组小鼠血清及肾组织标本。生化分析仪检测血清中的尿素氮（BUN）和肌酐（Scr）水平;ELISA法检测白介素-8（IL-8）、肿瘤坏死因子（TNF-α）和胱天蛋白酶7水平;免疫组织化学染色法检测高迁移率族蛋白1（HMGB1）表达水平;苏木-伊红（HE）染色和原位末端标记法（TUNEL）染色观察肾组织病理损伤;流式检测HK-2细胞凋亡率。结果显示,与WT Sham组对比,WT RIRI组血清中,BUN、Scr、IL-8和TNF-α含量增加（P<0.0001）;肾组织中,胱天蛋白酶7水平增高（P＜0.001）,HMGB1平均光密度值增加(P<0.0001),肾组织细胞凋亡指数（AI%）增高(P<0.0001)。与GT Sham组对比, GT RIRI组血清BUN、Scr、IL-8和TNF-α含量增加（P<0.05,P<0.0001, P<0.01, P<0.01）;肾组织中,胱天蛋白酶7水平明显增高（P＜0.01）,HMGB1平均光密度值增加(P<0.0001),肾组织细胞AI%增高(P=0.0005)。与WT RIRI组对比,GT RIRI组血清中的BUN、Scr水平降低（P<0.0001）,IL-8、TNF-α、HMGB1和胱天蛋白酶7的水平明显下降（P<0.01, P<0.0001, P<0.0001, P<0.01）,肾组织细胞凋亡指数（AI%）下降（P=0.0003）.与pLVX空载质粒+氯化钴组相比,pLVX-CHRFAM7A+氯化钴组的凋亡率(19.31%±1.45 vs 34.92%±4.21, P<0.001)明显下降。上述结果表明,人特异性CHRFAM7A基因在小鼠肾缺血再灌注损伤中,通过抑制早期的炎症反应,对肾组织发挥保护作用。     

Relationship between HIF-1α and apoptosis in rats with traumatic brain injury and the influence of traditional Chinese medicine Sanqi

Objective To explore the expression of HIF-1α, neuronal apoptosis and the influence of traditional Chinese medicine Sanqi on hematoma after brain injury in rats. Methods Ninety SD rats were divided into 3 groups randomly: blank control group, traumatic brain injury (TBI) group and Sanqi intervention group, and they were decapitated after brain injury at different time points: 6 h, 1 d, 2 d, 3 d, 5 d, 7 d. The model of cerebral hemorrhage was made by autologous non-coagulation in stereotactic locator, the expression of HIF-1α and TUNEL-positive cells (apoptotic cells) in the perihematomal area was detected by immunohistochemistry. Results In blank control group, a small amount of HIF-1α was expressed and apoptotic cells were observed. The expression of HIF-1α was up-regulated in the brain injury group from 6 h, and the apoptotic cells increased in abundance. The peak of HIF-1α was reached at 3 d, then decreased, and remained at the high level on the 7 d. Compared with blank control group, the TBI group was statistically significant (P < 0.05). The Chinese medicine Sanqi intervention group significantly up-regulated HIF-1α’expression and decreased neuronal apoptosis, which was statistically significant (P < 0.05). Conclusion HIF-1α’s expression was up-regulated around the hematoma after brain injury, and the apoptosis of nerve cells was obviously increased. The traditional Chinese medicine Sanqi can significantly increase the expression of HIF-1α, reduce the apoptosis around the hematoma, and thus play a neuroprotective role.     

Dexmedetomidine alleviates cerebral ischemia-reperfusion injury in rats via inhibition of hypoxia-inducible factor-1α

Dexmedetomidine (Dex) was reported to reduce ischemia-reperfusion (I/R) injury in kidney and brain tissues. Thus, we aimed to study the role and mechanism of Dex in cerebral I/R injury by inhibiting hypoxia-inducible factor-1α (HIF-1α) and apoptosis. First, I/R injury models were established. Six groups were assigned after different treatments: sham, I/R, I/R+Dex, I/R+2-methoxyestradiol (2ME2) (HIF-1α inhibitor), I/R+CoCl ₂ (HIF-1α activator), and I/R+Dex+CoCl ₂ groups. Neurological function, cerebral infarction volume, survival, and apoptosis of brain cells were then analyzed. Besides, immunohistochemistry and Western blot analysis were used to detect the expression of HIF-1α, BCL-2[B-cell leukemia/lymphoma 2] adenovirus E1B interacting protein 3 (BNIP3), B-cell leukemia/lymphoma 2 (BCL2), BCL2[B-cell leukemia/lymphoma 2] associated X (Bax), and cleaved-caspase3 proteins in brain tissues. I/R rats showed cerebral infarction, increased neurological function score, number of terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL)-positive cells and HIF-1α–positive cells as well as decreased neurons. Inhibition of HIF-1α can reduce the apoptosis induced by I/R, and overexpression of HIF-1α can aggravate apoptosis in brain tissue of I/R rats. Furthermore, activation of HIF-1α expression blocks the inhibitory effect of Dex on neuronal apoptosis in I/R rats. Dex may inhibit the neuronal apoptosis of I/R rats by inhibiting the HIF-1α pathway and then improve the cerebral I/R injury in rats.     

Protective Effect of Ginsenoside Rb1 against Intestinal Ischemia-Reperfusion Induced Acute Renal Injury in Mice

Ginsenoside Rb1 (RB1), the most clinically effective constituent of ginseng, possesses a variety of biological activities. The objectives of this study were to investigate the protective effects of RB1 and its underlying mechanism on renal injury induced by intestinal ischemia-reperfusion (IIR) in mice. RB1 was administered prior to inducing IIR achieved by occluding the superior mesenteric artery for 45 min followed by 120 min of reperfusion. All-trans-retinoic acid (ATRA) was used as an inhibitor of NF-E2-related factor-2 (Nrf2) signaling. Adult male C57BL/6J mice were randomly divided into six groups: (1) sham group, (2) IIR group, (3) RB1 group, (4) sham + ATRA group, (5) IIR + ATRA group, and (6) RB1 + ATRA group. Intestinal histology and pathological injury score were observed. Intestinal mucosal injury was also evaluated by measuring serum diamine oxidase (DAO). Renal injury induced by IIR was characterized by increased levels of histological severity score, blood urea nitrogen (BUN), serum creatinine (Scr) and neutrophil gelatinase-associated lipocalin (NGAL), which was accompanied with elevated renal TUNEL-positive cells and the Bcl-2/Bax expression ratio. RB1 significantly reduced renal injury and apoptosis as compared with IIR group, which was reversed by ATRA treatment. Immunohistochemistry and Western blot analysis demonstrated that RB1 significantly upregulated the protein expression of heme oxygenase-1 (HO-1) and Nrf2, which were attenuated by ATRA treatment. Taken together, these results suggest that the protective effects of RB1 pretreatment against renal injury induced by IIR are associated with activation of the Nrf2/ anti-oxidant response element (ARE) pathway.     

EPO对缺血/再灌注损伤大鼠心肌细胞Mfn2蛋白表达及心肌细胞凋亡的影响

目的观察重组人促红细胞生成素（recombinant human erythropoietin,rhEPO）对缺血/再灌注损伤大鼠心肌细胞Mitofusin2（Mfn2）蛋白表达的影响及其抗心肌细胞凋亡的作用。方法选取成年SD大鼠35只,随机分为正常组（Normal）,假手术组（Sham）,缺血再灌注组（I/R）,缺血再灌注EPO治疗组（I/R＋EPO）。各组分别于再灌注3h和24h后,剪取心脏缺血/再灌注损伤区域,用脱氧核苷酸末端转移酶介导的缺口末端标记法（TUNEL）检测心肌细胞凋亡,免疫组化法检测Mfn2蛋白的表达。结果再灌注3h和24h后,与正常组和假手术组相比,I/R组Mfn2蛋白的表达和心肌细胞凋亡均显著增加;与I/R组相比,I/R＋EPO组Mfn2蛋白的表达和心肌细胞凋亡均显著降低。结论EPO可以下调缺血再灌注损伤后心肌细胞Mfn2蛋白的表达,抑制心肌细胞的凋亡。     

MicroRNA-194 overexpression protects against hypoxia/reperfusion-induced HK-2 cell injury through direct targeting Rheb

Renal ischemia-reperfusion injury, a major cause of renal failure, always leads to acute kidney injury and kidney fibrosis. MicroRNAs (miRs) have been reported to be associated with renal ischemia-reperfusion injury. miR-194 was downregulated following renal ischemia-reperfusion injury; however, the function and mechanism of miR-194 in renal ischemia-reperfusion injury have not yet been fully understood. In the present study, we constructed renal ischemia-reperfusion injury model in vitro through treatment of human kidney proximal tubular epithelial cells HK-2 by hypoxia/reperfusion (H/R). We observed that miR-194 was decreased in H/R-induced HK-2 cells. miR-194 mimic increased H/R-induced HK-2 cell survival, whereas miR-194 inhibitor further strengthened H/R- inhibited HK-2 cell survival. Also, we observed that miR-194 overexpression suppressed oxidative stress markers, including malondialdehyde, glutathione, and secretion of pro-inflammatory cytokines, including IL-6, IL-1β, and TNF-α; however, miR-194 inhibitor showed the reverse effects. Results from dual-luciferase analysis confirmed that Ras homology enriched in brain (Rheb) was a direct target of miR-194. Finally, we corroborated that miR-194 affected cell growth, oxidative stress, and inflammation through targeting Rheb in H/R-induced HK-2 cells. In conclusion, our results suggested that miR-194 protect against H/R-induced injury in HK-2 cells through direct targeting Rheb.     

HIF-1α 在垂体腺瘤中的表达及与垂体腺瘤侵袭性的关系

目的:研究缺氧诱导因子-1α(HIF-1α)在人垂体腺瘤中的表达,对HIF-1α蛋白表达与肿瘤分级进行相关性分析,探讨其表达水平与垂体腺瘤侵袭性的关系.方法:集影像学检查、内分泌学检查及病理诊断的垂体腺瘤60例,分为侵袭组和非侵袭组,其中侵袭组36例,非侵袭组24例;对照组正常脑组织5例.免疫组织化学技术检测HIF-1α蛋白的表达,结合临床资料进行统计学分析.分析垂体腺瘤HIF-1α蛋白的表达水平并与对照组进行比较,比较侵袭组和非侵袭组垂体腺瘤之间HIF-1α蛋白表达水平的差异.结果:HIF-1α蛋白在垂体腺瘤中的表达明显高于对照组,二者比较,x20.05,1=12.392,P＜0.001,有显著性差异;侵袭组HIF-1α蛋白的表达较非侵袭组显著增高,二者比较,x20.05.1=24.658,P＜0.001,有显著性差异.结论:H1F-1α是垂体腺瘤侵袭过程中的重要调控因子,与垂体腺瘤的大小、分级以及侵袭性密切相关,其作用机制有待进一步研究,其表达程度可用作垂体腺瘤预后的评估指标,为垂体腺瘤术后的复发以及相应的辅助治疗提供判断依据.有可能为人们靶向肿瘤缺氧来开发新药物提供新的作用靶点.