氟伐他汀对糖尿病大鼠肾脏CTGF表达的影响

目的观察氟伐他汀对糖尿病大鼠肾脏结缔组织生长因子(CTGF)表达的影响。方法用链脲佐菌素复制糖尿病大鼠模型,成模后给予氟伐他汀治疗。采用ELISA法检测尿微量白蛋白浓度;Western blot和RT-PCR法检测大鼠肾皮质CT-GF蛋白及mRNA的表达水平;免疫组化法检测肾小球内CTGF和FN的表达。结果氟伐他汀治疗组大鼠尿白蛋白排泄率、肾脏肥大指数(KHI)、肾皮质中CTGF的mRNA及蛋白表达、肾小球内CTGF和FN的表达较糖尿病组大鼠均明显降低。结论氟伐他汀能降低肾小球内CTGF及FN的表达,减轻肾小球肥大,起到抑制和延缓糖尿病肾病进展的作用。     

重组腺相关病毒介导克老素基因表达对2型糖尿病大鼠肾脏纤维化的作用及其机制

目的观察重组腺相关病毒(recombinant adeno-associated virus,rAAV)介导的克老素(klotho,KL)基因表达对2型糖尿病(type 2 diabetes mellitus,T2DM)大鼠肾脏纤维化的影响及其机制。方法将SD大鼠随机分为4组,随机选3组建立T2DM大鼠模型,分别经尾静脉注射rAAV.mKL(T2DM-mKL组)、rAAV.GFP(T2DM-GFP组)和PBS(T2DM-PBS组),正常对照(SD-PBS组)大鼠经尾静脉注射PBS,12周后,处死动物,收集肾脏组织标本,冰冻切片观察GFP,Masson染色观察肾脏组织病理变化及胶原纤维表达;免疫组化法检测各组大鼠肾脏组织中KL和波形蛋白(vimentin,VIM)的表达;RT-PCR法检测各组大鼠肾脏组织中Rho激酶(Rho associated coiled-coilforming protein kinase,ROCK)基因mRNA转录水平;Western blot法检测各组大鼠肾脏组织中ROCKⅠ蛋白活性。结果 T2DM-GFP组、T2DM-mKL组大鼠肾脏组织中GFP表达较强;T2DM-mKL组大鼠肾小球基底膜结构较清晰完整,肾小球系膜区及肾小管间质区胶原纤维明显较T2DM-PBS组和T2DM-GFP组减少;T2DM-mKL组KL蛋白的表达明显高于其他各组(P<0.01),VIM蛋白的表达明显低于其他各组,与T2DM-PBS组和T2DM-GFP组VIM蛋白的表达相比,差异有统计学意义(P<0.01);T2DM-mKL组ROCKⅠmRNA转录水平及其蛋白活性均明显低于T2DM-PBS组(P均<0.05)。结论 rAAV.mKL转染可明显增加T2DM大鼠肾脏中KL基因的表达,延缓糖尿病肾纤维化进程,其机制可能与KL抑制ROCK信号通路活性相关。     

阿昔莫司对RAW 264.7细胞三磷酸腺苷结合盒转运子A1表达及其调控的影响

目的研究阿昔莫司对巨噬细胞RAW264.7三磷酸腺苷结合盒转运子A1(ATP binding cassette transporterA1,ABCA1)及其上游调控因子肝脏X受体α(Liver X receptor,LXRα)的影响,探讨其促进胆固醇逆转运(Reversecholesterol transport,RCT)、抗动脉粥样硬化(Atherosclerosis,AS)的可能机制。方法体外培养RAW264.7细胞,将细胞分为空白对照组(不含阿昔莫司)和不同浓度的阿昔莫司干预组(分别含5、10、25μg/ml阿昔莫司),作用24 h后,采用RT-PCR法检测各组细胞中ABCA1和LXRα基因mRNA的转录水平;Western blot法检测各组细胞中ABCA1和LXRα蛋白的表达;闪烁计数法检测各组细胞内胆固醇的流出。结果阿昔莫司呈浓度依赖性地增加RAW264.7细胞中ABCA1和LXRα基因mRNA的转录水平和蛋白的表达水平(P<0.05或P<0.01)及细胞内胆固醇的流出率(P<0.01)。结论阿昔莫司可通过LXRα途径上调巨噬细胞ABCA1的表达,促使细胞内胆固醇流出,从而延缓AS的发生发展。     

氯沙坦对肾衰大鼠RAS基因表达的影响

目的观察氯沙坦对肾衰大鼠肾组织肾素-血管紧张素系统(RAS)血管紧张素1型受体(AT1)、血管紧张素2型受体(AT2)、血管紧张素转化酶(ACE)及血管紧张素原(AGT)基因表达的影响,探讨RAS在慢性肾衰发生发展过程中的作用。方法复制阿霉素(ADR)慢性肾衰大鼠动物模型,随机分为模型(ADR)组和血管紧张素受体拮抗剂(ARB)氯沙坦(ADR+ARB)组,氯沙坦组给予氯沙坦灌胃,另设正常大鼠对照组。取各组大鼠肾组织,经HE染色进行形态学观察,半定量RT-PCR法检测AT1、AT2、ACE及AGT基因mRNA的转录水平。结果与对照组相比,ADR组大鼠肾小球和肾小管出现明显的病变,而ADR+ARB组病变明显减轻。与对照组相比,ADR组AT1﹑AGT和ACE基因表达上调,AT2基因表达下调;与ADR组相比,ADR+ARB组AT1和AGT基因表达下调;ADR+ARB组的AT2基因表达水平接近对照组,ACE基因表达下调,但仍高于对照组水平。结论慢性肾损伤的发生发展可能与AT1、AGT及ACE基因表达水平增高有关。     

Klotho基因高表达对糖尿病肾病大鼠肾脏的保护作用

目的观察Klotho基因高表达对糖尿病肾病(diabeticnephropathy,DN)大鼠肾脏的保护作用。方法采用RT-PCR法从健康Wistar大鼠肾脏中分段扩增Klotho基因,将两段基因连接后,亚克隆至腺病毒载体shuttle中,构建重组质粒shuttle/Klotho,与腺病毒骨架质粒共转染AD293细胞进行包装后,检测重组腺病毒的滴度。经Wistar大鼠腹腔注射链脲佐菌素(streptozotocin,STZ)复制DN模型,将DN模型大鼠随机分成DN组、Ad组和Klotho组,从糖尿病(diabetes mellitus,DM)模型建立成功后2周开始,Ad组每只经尾静脉注射3×108 PFU不含Klotho基因的腺病毒,Klotho组每只经尾静脉注射3×108 PFU含Klotho基因的重组腺病毒,DN组每只经尾静脉注射等体积生理盐水;并设对照组(即Con组,制备糖尿病模型时,经腹腔注射等量柠檬酸缓冲液,治疗时经尾静脉注射等体积生理盐水)。各组均每2周注射1次。实验期间,每天观察各组大鼠一般情况。分别于糖尿病模型建立成功后第4、8、16周,称量大鼠体重并处死,取左侧肾组织称重,计算肾脏指数(renal index,RI);显微镜下观察肾脏的病理学改变;RT-PCR法检测大鼠肾脏组织中Klotho基因mRNA的转录水平;ELISA法检测尿微量白蛋白水平,比浊法检测血尿素氮和血肌酐水平。结果酶切及测序鉴定证实克隆的Klotho基因正确。含Klotho基因的重组腺病毒的滴度为4.2×108 PFU/ml。DN、Ad和Klotho组大鼠从DM模型建立成功后第2周开始毛色逐渐无光泽,体重降低,活动能力减弱,食量、饮水量增加,粪便偏稀,精神状态差;从第6周开始,Klotho组大鼠的上述症状均有所改善。DM模型建立成功后第4、8、16周,与Con组相比,DN和Ad组大鼠的RI、尿微量白蛋白、血肌酐和血尿素氮水平均显著增加(P0.01),而Klotho组RI和尿微量白蛋白水平显著低于DN和Ad组(P0.05或P0.01),血肌酐和血尿素氮水平也下降,且第8、16周DN和Ad组大鼠血肌酐和血尿素氮水平高于第4周,而Klotho组无此现象;DN和Ad组大鼠的肾小球体积明显增大,肾小球系膜细胞增生,系膜区明显增宽,基膜增厚、基质大量堆积,部分肾小球出现硬化,肾小管上皮细胞肿胀,而Klotho组大鼠肾脏上述病变较DN和Ad组减轻;DN和Ad组大鼠肾脏组织中Klotho基因mRNA的转录水平明显减少(P0.05或P0.01),Klotho组变化不明显,但高于DN和Ad组(P0.01)。结论 Klotho基因高表达可减轻DN大鼠的肾脏损伤,对肾脏具有保护作用。     

CpG-ODN对肾小球肾炎进展的影响

目的观察CpG-ODN对肾小球肾炎进展的影响。方法将Wistar雄性大鼠随机分为N组(正常对照)、M组(模型对照)、CpG组和GpC组。N组大鼠经尾静脉注射生理盐水2.5ml/(kg·d),其余3组大鼠经尾静脉注射抗-thy1.1单克隆抗体2.5ml/(kg·d),隔日1次,共3次。注射抗-thy1.1单克隆抗体后,隔天,CpG组经尾静脉注射CpG-ODN,300μg/只,GpC组经尾静脉注射GpC-ODN,300μg/只,隔日注射,共3次。各组大鼠分别于用药前和第1针注射后1周测定尿蛋白;用药后第8周留取大鼠24h尿、血清及肾脏组织,检测24h尿蛋白定量、血清白蛋白和肾功;肾脏组织用于肾脏病理检查以及RT-PCR法检测TLR-9mRNA的表达。结果CpG组与M组和GpC组相比,血清白蛋白含量明显降低,且差异有显著意义;M组、CpG组和GpC组在给药后1周均出现尿蛋白,在给药后8周,24h尿蛋白含量明显增多;CpG组与M组相比,TLR-9mRNA在肾脏的表达水平明显增加,且差异有显著意义;GpC组与M组相比,差异无显著意义;光镜下可见CpG组肾组织病理改变明显加重。结论天然CpG-ODN可促进肾小球肾炎病情加重,TLR-9可能在其发生机理中起重要作用。     

亚致死剂量马拉硫磷导致小鼠肾损伤及内质网应激分析

[目的]探讨有机磷化合物对哺乳动物肾组织的毒效作用,为有机磷的非胆碱能毒理机制研究提供参考。[方法]选取马拉硫磷为有机磷代表,分别以1/3 LD_(50)、1/10 LD_(50)、1/25 LD_(50)亚致死剂量马拉硫磷经口灌胃小鼠18 d,苏木精-伊红(HE)染色观察各组肾组织病理变化情况,荧光定量PCR和免疫组织化学染色法测定药物处理前后肾组织DDIT3基因的m RNA和蛋白表达情况。[结果]亚致死剂量马拉硫磷可以升高小鼠血液中的血尿素氮、肌酐、尿酸含量。HE染色显示,与对照组比较,1/3 LD_(50)和1/10 LD_(50)剂量组对小鼠肾小球、肾小囊腔内、肾静脉血管损伤显著。荧光定量PCR和IHC结果显示,马拉硫磷可显著升高小鼠肾组织中内质网应激的标志基因DDIT3的m RNA水平和蛋白表达。[结论]以上结果提示,亚致死剂量马拉硫磷可致肾组织损伤,增加肾细胞的内质网应激,诱导肾细胞凋亡可能是其产生损伤的原因之一。     

缰核损毁对下丘脑内GABA_A受体α1亚单位表达的影响

目的观察缰核损毁对下丘脑内GABAA受体α1亚单位(GABAAα1)表达的影响,以揭示缰核与下丘脑之间功能联系的可能的分子机制。方法建立缰核损毁大鼠模型,以假手术组为对照。分离下丘脑,提取总RNA及总蛋白,采用RT-PCR和Western blot方法检测两组大鼠下丘脑内GABAAα1 mRNA的转录水平及蛋白的表达水平。结果缰核损毁大鼠下丘脑内GABAAα1 mRNA的转录水平及蛋白表达水平均明显高于假手术对照组。结论缰核损毁可显著提高下丘脑内GABAAα1的表达水平,提示GABAA受体可能在缰核与下丘脑共同参与的生理调节过程中起重要作用。     

血脂康对新生大鼠心肌成纤维细胞增殖及胶原合成的影响

目的观察血脂康对血管紧张素Ⅱ(AngⅡ)诱导的新生大鼠心肌成纤维细胞(CFs)增殖及胶原合成的影响,并探讨可能的分子机制。方法采用胰酶消化法分离培养Sprague-Dawley大鼠心肌成纤维细胞,建立AngⅡ诱导CFs增殖的模型,以MTT比色法和流式细胞仪检测细胞周期分析法观察血脂康对CFs数目和细胞周期的影响。AngⅡ及不同浓度血脂康作用48 h后,用天狼星红染色法检测培养上清中胶原的含量;ELISA法检测细胞培养上清液中TGF-β1蛋白表达;RT-PCR法检测胶原和TGF-β1 mRNA表达。结果AngⅡ对CFs增殖有明显促进作用,血脂康可明显抑制AngⅡ诱导的CFs增殖,且呈剂量依赖性;血脂康可增加G0/G1期细胞百分率,降低S、G2/M期细胞百分率,降低胶原含量、TGF-β1蛋白及胶原和TGF-β1 mRNA的表达。结论血脂康能抑制AngⅡ诱导的CFs增殖和胶原的产生,其作用可能是通过抑制TGF-β1表达实现的。     

ClC-2氯通道在大鼠小梁网中的表达

目的分析电压门控性氯通道ClC家族中的ClC-2氯通道在大鼠小梁网中的表达,探讨ClC-2在青光眼发病机制中的可能作用。方法经前房内注射玻璃酸钠建立大鼠慢性高眼压模型,取正常大鼠及模型大鼠小梁网组织,采用RT-PCR法检测ClC-2基因mRNA的转录水平,免疫组化法检测ClC-2蛋白的表达水平。结果在正常大鼠和慢性高眼压模型大鼠小梁网组织中,均可检测到ClC-2的表达,且模型大鼠ClC-2基因mRNA的转录水平和蛋白的表达水平均较正常大鼠降低。结论大鼠小梁组织中存在ClC-2氯通道的表达,该通道的表达受小梁网的一些病理因素的影响。     

The Urinary Level of Injury Biomarkers Is Not Univocally Reflective of the Extent of Toxic Renal Tubular Injury in Rats

Nephrotoxicity is a major cause of intrinsic acute kidney injury (AKI). Because renal tissue damage may occur independently of a reduction in glomerular filtration rate and of elevations in plasma creatinine concentration, so-called injury biomarkers have been proposed to form part of diagnostic criteria as reflective of tubular damage independently of renal function status. We studied whether the urinary level of NGAL, KIM-1, GM2AP, t-gelsolin, and REGIIIb informed on the extent of tubular damage in rat models of nephrotoxicity, regardless of the etiology, moment of observation, and underlying pathophysiology. At a time of overt AKI, urinary biomarkers were measured by Western blot or ELISA, and tubular necrosis was scored from histological specimens stained with hematoxylin and eosin. Correlation and regression studies revealed that only weak relations existed between biomarkers and tubular damage. Due to high interindividual variability in the extent of damage for any given biomarker level, urinary injury biomarkers did not necessarily reflect the extent of the underlying tissue injury in individual rats. We contended, in this work, that further pathophysiological contextualization is necessary to understand the diagnostic significance of injury biomarkers before they can be used for renal tubular damage severity stratification in the context of nephrotoxic and, in general, intrinsic AKI.     

Suppressed Hepatic Production of Indoxyl Sulfate Attenuates Cisplatin-Induced Acute Kidney Injury in Sulfotransferase 1a1-Deficient Mice

Endogenous factors involved in the progression of cisplatin nephropathy remain undetermined. Here, we demonstrate the toxico-pathological roles of indoxyl sulfate (IS), a sulfate-conjugated uremic toxin, and sulfotransferase 1A1 (SULT1A1), an enzyme involved in its synthesis, in cisplatin-induced acute kidney injury using Sult1a1-deficient (Sult1a1^-/- KO) mice. With cisplatin administration, severe kidney dysfunction, tissue damage, and apoptosis were attenuated in Sult1a1^-/- (KO) mice. Aryl hydrocarbon receptor (AhR) expression was increased by treatment with cisplatin in mouse kidney tissue. Moreover, the downregulation of antioxidant stress enzymes in wild-type (WT) mice was not observed in Sult1a1^-/- (KO) mice. To investigate the effect of IS on the reactive oxygen species (ROS) levels, HK-2 cells were treated with cisplatin and IS. The ROS levels were significantly increased compared to cisplatin or IS treatment alone. IS-induced increases in ROS were reversed by downregulation of AhR, xanthine oxidase (XO), and NADPH oxidase 4 (NOX4). These findings suggest that SULT1A1 plays toxico-pathological roles in the progression of cisplatin-induced acute kidney injury, while the IS/AhR/ROS axis brings about oxidative stress.     

In Vivo and In Vitro Evaluation of Urinary Biomarkers in Ischemia/Reperfusion-Induced Kidney Injury

Oxidative stress plays an important role in the pathophysiology of acute kidney injury (AKI). Previously, we reported that vanin-1, which is involved in oxidative stress, is associated with renal tubular injury. This study was aimed to determine whether urinary vanin-1 is a biomarker for the early diagnosis of AKI in two experimental models: in vivo and in vitro. In a rat model of AKI, ischemic AKI was induced in uninephrectomized rats by clamping the left renal artery for 45 min and then reperfusing the kidney. On Day 1 after renal ischemia/reperfusion (I/R), serum creatinine (SCr) in I/R rats was higher than in sham-operated rats, but this did not reach significance. Urinary N-acetyl-β-D-glucosaminidase (NAG) exhibited a significant increase but decreased on Day 2 in I/R rats. In contrast, urinary vanin-1 significantly increased on Day 1 and remained at a significant high level on Day 2 in I/R rats. Renal vanin-1 protein decreased on Days 1 and 3. In line with these findings, immunofluorescence staining demonstrated that vanin-1 was attenuated in the renal proximal tubules of I/R rats. Our in vitro results confirmed that the supernatant from HK-2 cells under hypoxia/reoxygenation included significantly higher levels of vanin-1 as well as KIM-1 and NGAL. In conclusion, our results suggest that urinary vanin-1 might be a potential novel biomarker of AKI induced by I/R.     

The Protective Role of Prolyl Oligopeptidase (POP) Inhibition in Kidney Injury Induced by Renal Ischemia–Reperfusion

Ischemia/reperfusion injury (IRI) is a complex pathophysiological process characterized by blood circulation disorder caused by various factors, such as traumatic shock, surgery, organ transplantation, and thrombus. Severe metabolic dysregulation and tissue structure destruction are observed upon restoration of blood flow to the ischemic tissue. The kidney is a highly perfused organ, sensitive to ischemia and reperfusion injury, and the incidence of renal IRI has high morbidity and mortality. Several studies showed that infiltration of inflammatory cells, apoptosis, and angiogenesis are important mechanisms involved in renal IRI. Despite advances in research, effective therapies for renal IRI are lacking. Recently it has been demonstrated the role of KYP2047, a selective inhibitor of prolyl oligopeptidase (POP), in the regulation of inflammation, apoptosis, and angiogenesis. Thus, this research focused on the role of POP in kidney ischemia/reperfusion (KI/R). An in vivo model of KI/R was performed and mice were subjected to KYP2047 treatment (intraperitoneal, 0.5, 1 and 5 mg/kg). Histological analysis, Masson’s trichrome and periodic acid shift (PAS) staining, immunohistochemical and Western blots analysis, real-time PCR (RT-PCR) and ELISA were performed on kidney samples. Moreover, serum creatinine and blood urea nitrogen (BUN) were quantified. POP-inhibition by KYP2047 treatment, only at the doses of 1 and 5 mg/kg, significantly reduced renal injury and collagen amount, regulated inflammation through canonical and non-canonical NF-κB pathway, and restored renal function. Moreover, KYP2047 modulated angiogenesis markers, such as TGF-β and VEGF, also slowing down apoptosis. Interestingly, treatment with KYP2047 modulated PP2A activity. Thus, these findings clarified the role of POP inhibition in AKI, also offering novel therapeutic target for renal injury after KI/R.     

Protective Effect of D-Panthenol in Rhabdomyolysis-Induced Acute Kidney Injury

We investigated the nephroprotective effect of D-panthenol in rhabdomyolysis-induced acute kidney injury (AKI). Adult male Wistar rats were injected with 50% glycerol solution to induce rhabdomyolysis. Animals with rhabdomyolysis were injected with D-panthenol (200 mg/kg) for 7 days. On day 8, we examined AKI markers, renal histology, antioxidant capacity, and protein glutathionylation in kidneys to uncover mechanisms of D-panthenol effects. Rhabdomyolysis kidneys were shown to have pathomorphological alterations (mononuclear infiltration, dilatation of tubules, and hyaline casts in Henle’s loops and collecting ducts). Activities of skeletal muscle damage markers (creatine kinase and lactate dehydrogenase) increased, myoglobinuria was observed, and creatinine, BUN, and pantetheinase activity in serum and urine rose. Signs of oxidative stress in the kidney tissue of rhabdomyolysis rats, increased levels of lipid peroxidation products, and activities of antioxidant enzymes (SOD, catalase, and glutathione peroxidase) were all alleviated by administration of D-panthenol. Its application improved kidney morphology and decreased AKI markers. Mechanisms of D-panthenol’s beneficial effects were associated with an increase in total coenzyme A levels, activity of Krebs cycle enzymes, and attenuation of protein glutathionylation. D-Panthenol protects kidneys from rhabdomyolysis-induced AKI through antioxidant effects, normalization of mitochondrial metabolism, and modulation of glutathione-dependent signaling.     

Study of the Role of the Tyrosine Kinase Receptor MerTK in the Development of Kidney Ischemia-Reperfusion Injury in RCS Rats

Renal ischaemia reperfusion (I/R) triggers a cascade of events including oxidative stress, apoptotic body and microparticle (MP) formation as well as an acute inflammatory process that may contribute to organ failure. Macrophages are recruited to phagocytose cell debris and MPs. The tyrosine kinase receptor MerTK is a major player in the phagocytosis process. Experimental models of renal I/R events are of major importance for identifying I/R key players and for elaborating novel therapeutical approaches. A major aim of our study was to investigate possible involvement of MerTK in renal I/R. We performed our study on both natural mutant rats for MerTK (referred to as RCS) and on wild type rats referred to as WT. I/R was established by of bilateral clamping of the renal pedicles for 30′ followed by three days of reperfusion. Plasma samples were analysed for creatinine, aspartate aminotransferase (ASAT), lactate dehydrogenase (LDH), kidney injury molecule -1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels and for MPs. Kidney tissue damage and CD68-positive cell requirement were analysed by histochemistry. monocyte chemoattractant protein-1 (MCP-1), myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), and histone 3A (H3A) levels in kidney tissue lysates were analysed by western blotting. The phagocytic activity of blood-isolated monocytes collected from RCS or WT towards annexin-V positive bodies derived from cultured renal cell was assessed by fluorescence-activated single cell sorting (FACS) and confocal microscopy analyses. The renal I/R model for RCS rat described for the first time here paves the way for further investigations of MerTK-dependent events in renal tissue injury and repair mechanisms.     

大鼠急性脊髓损伤后热休克蛋白47基因mRNA的转录水平

目的探讨大鼠急性脊髓损伤(Spinal cord injury,SCI)后热休克蛋白47(HSP47)基因mRNA的转录水平。方法将12只Wistar大鼠随机分为1周SCI组、3周SCI组、5周SCI组和8周SCI组,复制钳夹型SCI模型,另设正常对照组和假手术组。分别在SCI后3d及每周进行BBB评分,并在1周、3周、5周和8周采用半定量RT-PCR法检测各组大鼠脊髓组织中HSP47基因mRNA的转录水平。结果SCI后,BBB评分低,随着时间的延长,评分逐渐上升;HSP47基因mRNA的转录水平明显升高,且在第8周升高更为明显。结论Wistar大鼠SCI后,HSP47基因mRNA的转录水平升高,提示其很可能参与了SCI的病理改变过程。     

Matrix Metalloproteinase-10 in Kidney Injury Repair and Disease

Matrix metalloproteinase-10 (MMP-10) is a zinc-dependent endopeptidase with the ability to degrade a broad spectrum of extracellular matrices and other protein substrates. The expression of MMP-10 is induced in acute kidney injury (AKI) and chronic kidney disease (CKD), as well as in renal cell carcinoma (RCC). During the different stages of kidney injury, MMP-10 may exert distinct functions by cleaving various bioactive substrates including heparin-binding epidermal growth factor (HB-EGF), zonula occludens-1 (ZO-1), and pro-MMP-1, -7, -8, -9, -10, -13. Functionally, MMP-10 is reno-protective in AKI by promoting HB-EGF-mediated tubular repair and regeneration, whereas it aggravates podocyte dysfunction and proteinuria by disrupting glomerular filtration integrity via degrading ZO-1. MMP-10 is also involved in cancerous invasion and emerges as a promising therapeutic target in patients with RCC. As a secreted protein, MMP-10 could be detected in the circulation and presents an inverse correlation with renal function. Due to the structural similarities between MMP-10 and the other MMPs, development of specific inhibitors targeting MMP-10 is challenging. In this review, we summarize our current understanding of the role of MMP-10 in kidney diseases and discuss the potential mechanisms of its actions.     

TUNEL Assay: A Powerful Tool for Kidney Injury Evaluation

Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay is a long-established assay used to detect cell death-associated DNA fragmentation (3’-OH DNA termini) by endonucleases. Because these enzymes are particularly active in the kidney, TUNEL is widely used to identify and quantify DNA fragmentation and cell death in cultured kidney cells and animal and human kidneys resulting from toxic or hypoxic injury. The early characterization of TUNEL as an apoptotic assay has led to numerous misinterpretations of the mechanisms of kidney cell injury. Nevertheless, TUNEL is becoming increasingly popular for kidney injury assessment because it can be used universally in cultured and tissue cells and for all mechanisms of cell death. Furthermore, it is sensitive, accurate, quantitative, easily linked to particular cells or tissue compartments, and can be combined with immunohistochemistry to allow reliable identification of cell types or likely mechanisms of cell death. Traditionally, TUNEL analysis has been limited to the presence or absence of a TUNEL signal. However, additional information on the mechanism of cell death can be obtained from the analysis of TUNEL patterns.