Vitamin A could be a Therapeutic Agent in Ischemia/Reperfusion Induced Kidney Injury / La vitamina A podría ser un agente terapéutico en la lesión renal inducida por isquemia/reperfusión

ABSTRACT Introduction: Renal ischemia (I) could develop due to decreased or ceased blood flow to the kidney in some clinical conditions such as shock, sepsis, and kidney transplantation. The re-supply of blood to the kidney is called reperfusion (R). Ischemia and reperfusion periods can cause severe kidney damage. Objectives: When we examined the I/R molecular progression, antioxidant molecules such as vitamin A seem promising treatment agents. This study aimed to investigate the effects of vitamin A on renal I/R injury. Material and Methods: In the study, 40 Sprague-Dawley male rats were divided into five groups (n=8): the control group, only I/R, I/R+1000, I/R+3000, and I/R+9000 IU/kg of Vitamin A groups. Vitamin A was administrated to each group for seven days via oral gavage. Blood and kidney tissue samples were collected at the end of the experiment. We took blood samples for Superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), blood urea nitrogen (BUN), and creatinine (Cr) levels, and determined their values. The tissue samples were stained with hematoxylin/eosin to examine the renal changes histopathologically and stereologically under a light microscope. Results: Histopathological changes caused by I/R were decreased with vitamin A administration in a dose-dependent manner (p<0.05). Vitamin A administration decreased MDA levels and increased SOD and CAT activities (p<0.05). The most effective dose among treatment groups was 9000 IU/kg. There was no significant difference between the controls and all other groups regarding BUN and Cr concentrations. Conclusions: Consequently, administration of vitamin A after renal I/R reduced the histological damage and ameliorated the antioxidant state. These results showed that vitamin A could be a promising agent in treating I/R-induced acute kidney injury.

RESUMEN Introducción: La isquemia renal (I) puede desarrollarse debido a la disminución o interrupción del flujo sanguíneo al riñón en algunas condiciones clínicas como shock, sepsis y trasplante renal. El reabastecimiento de sangre al riñón se denomina reperfusión (R). Tanto la isquemia como los períodos de reperfusión pueden causar graves daños renales. Objetivos: Cuando examinamos la progresión molecular I/R, las moléculas antioxidantes como la vitamina A parecen agentes de tratamiento prometedores. El objetivo de este estudio fue investigar los efectos de la vitamina A sobre la lesión renal I/R. Material y Métodos: En el estudio, 40 ratas macho Sprague-Dawley se dividieron en 5 grupos (n=8) como: control, solo I/R, I/R+1000, I/R+3000 e I/R+9000 UI/kg de la Vitamina A. La vitamina A se administró a cada grupo durante 7 días por vía oral forzada. Al final del experimento se recolectaron muestras de sangre y tejido del riñón. A partir de muestras de sangre se determinaron los niveles de superóxido dismutasa (SOD), malondialdehído (MDA), catalasa (CAT), nitrógeno ureico en sangre (BUN) y creatinina (Cr). Las muestras de tejido se tiñeron con hematoxilina/eosina y los cambios en la histología renal se examinaron histopatológicamente y estereológicamente al microscopio de luz. Resultados: Los cambios histopatológicos causados por I/R disminuyeron con la administración de la vitamina A de manera dependiente de la dosis (p<0,05). La administración de la vitamina A disminuyó los niveles de MDA, aumentó las actividades de SOD y CAT (p<0,05). La dosis más eficaz entre los grupos del tratamiento fue de 9000 UI/kg. No hubo una diferencia significativa entre el grupo control y todos los demás grupos con respecto a las concentraciones de BUN y Cr. Conclusiones: Consiguientemente, la administración de la vitamina A, después de I/R renal, redujo el daño histológico y mejoró el estado antioxidante. Estos resultados mostraron que la vitamina A puede ser un agente promisorio en el tratamiento de la lesión renal aguda (LRA) inducida por I/R.

Naringin and trimetazidine improve baroreflex sensitivity and nucleus tractus solitarius electrical activity in renal ischemia-reperfusion injury / Naringin and trimetazidine improve baroreflex sensitivity and nucleus tractus solitarius electrical activity in renal ischemia-reperfusion injury

Resumo Fundamento: O núcleo do trato solitário (NTS) é uma área do cérebro que desempenha um papel fundamental na regulação renal e cardiovascular através dos impulsos dos barorreceptores. Objetivos: O objetivo deste estudo foi avaliar o efeito da Naringina (NAR) e trimetazidina (TMZ), isoladamente e combinadas, na atividade elétrica do NTS e na sensibilidade barorreflexa (SBR) na lesão de isquemia e reperfusão (I/R) renal. Métodos: Foram utilizados quarenta ratos machos Sprague-Dawley (200-250 g), alocados em 5 grupos com 8 ratos cada. Grupos: 1) Sham; 2) I/R; 3) TMZ 5 mg/kg; 4) NAR 100 mg/kg; e 5) TMZ5 + NAR100. A veia femoral esquerda foi canulada para infundir a solução salina ou droga e avaliar a SBR. A I/R foi induzida por oclusão dos pedículos renais por 45 min, seguida de reperfusão de 4 horas. O eletroencefalograma local do NTS foi registrado antes, durante a isquemia e durante a reperfusão. A fenilefrina foi injetada por via intravenosa para avaliar a SBR ao final do tempo de reperfusão. Os dados foram analisados por ANOVA de duas vias com medidas repetidas seguida pelo teste post hoc de Tukey. Um valor de p<0,05 foi considerado como significativo. Resultados: As ondas elétricas do NTS não se alteraram durante o tempo de isquemia, mas diminuíram significativamente durante todos os tempos de reperfusão. A atividade elétrica do NTS e a SBR foram reduzidas drasticamente em ratos com lesão I/R; no entanto, a administração de NAR e TMZ, isoladamente e combinadas, melhorou significativamente essas alterações em ratos com lesão I/R. Conclusões: Os resultados mostraram que a lesão de I/R leva à redução da atividade elétrica da SBR e do NTS, e pode haver uma ligação entre a I/R e a diminuição da SBR. Além disso, a NAR e a TMZ são agentes promissores para tratar complicações de I/R.

Abstract Background: Nucleus tractus solitarius (NTS) is a brain area that plays a key role in kidney and cardiovascular regulation via baroreceptors impulses. Objectives: The aim of this study was to evaluate the effect of naringin (NAR) and trimetazidine (TMZ) alone and their combination on NTS electrical activity and baroreceptor sensitivity (BRS) in renal ischemia- reperfusion (I/R) injury. Methods: Forty male Sprague-Dawley rats (200- 250 g) were allocated into 5 groups with 8 in each. 1) Sham; 2) I/R; 3) TMZ 5 mg/kg; 4) NAR 100 mg/kg; and 5) TMZ5+ NAR100. The left femoral vein was cannulated to infuse saline solution or drug and the BRS was evaluated. I/R was induced by occlusion of renal pedicles for 45 min, followed by 4 hours of reperfusion. The NTS local electroencephalogram (EEG) was recorded before, during ischemia and throughout the reperfusion. Phenylephrine was injected intravenously to evaluate BRS at the end of reperfusion time. The data were analyzed by two-way repeated measurement ANOVA followed by Tukey's post hoc test. A p-value <0.05 was considered significant. Results: NTS electrical waves did not change during ischemia time, while they significantly decreased during the entire reperfusion time. NTS electrical activity and BRS dramatically reduced in rats with I/R injury; however, administration of NAR, TMZ alone or their combination significantly improved these changes in rats with I/R injury. Conclusions: The results showed that I/R injury leads to reduced BRS and NTS electrical activity and there may be an association between I/R and decreased BRS. In addition, NAR and TMZ are promising agents to treat I/R complications.

The progress on the mechanism of NLRP3 inflammasome in renal ischemia-reperfusion injury / 中华泌尿外科杂志

Renal ischemia-reperfusion injury often occurs during operations that need to block the blood supply of the kidneys. It is an important pathophysiological process that affects the recovery of kidney function and causes acute renal failure. Activated NLRP3 inflammasome can mediate the maturation and release of a variety of pro-inflammatory factors, and participate in the inflammatory response in renal ischemia-reperfusion injury, thereby regulating body inflammation and related cell functions. This article summarized how NLRP3 inflammasome mediated the occurrence of inflammation in renal ischemia reperfusion injury, and further provied a new basis for the prevention and treatment of renal ischemia-reperfusion injury.

Effect of protein kinase C β inhibitor on renal ischemia-reperfusion injury and expression level of macrophage subtypes in rat models / 器官移植

Objective To investigate the effect of protein kinase C (PKC) β inhibitor on the renal ischemia-reperfusion injury (RIRI) in rat models and detect the expression level of macrophage subtypes. Methods Eighteen healthy SD male rats were randomly divided into the Sham operation group (Sham group, n=6), RIRI group (n=6), PKCβ inhibitor +RIRI group (Inhibitor+RIRI group, n=6). Serum and left renal tissue samples were collected at postoperative 24 h. The contents of serum creatinine (Scr) and blood urea nitrogen (BUN) were detected by automatic biochemical analyzer. The infiltration of inflammatory cells and pathological injury in the renal tissues were observed by hematoxylin-eosin (HE) staining. The expression levels of CD68, inducible nitric oxide synthase (iNOS) and CD206 proteins in the renal tissues of rats in each group were assessed by immunohistochemistry and Western blot. Results The contents of serum Scr and BUN in the RIRI group were significantly higher than those in the Sham group (both P < 0.05). The contents of serum Scr and BUN in the Inhibitor+RIRI group were considerably lower than those in the RIRI group (both P < 0.05). No obvious renal injury was noted in the Sham group, whereas renal inflammatory cell infiltration and renal tubular structural damage were observed in the RIRI group. The renal inflammatory cell infiltration and renal tubular structural damage in the Inhibitor+RIRI group was slighter than that in the RIRI group. The protein expression levels of CD68, iNOS and CD206 in the renal tissue of rats in the RIRI group were significantly higher than those in the Sham group (all P < 0.05). The protein expression levels of CD68 and iNOS in the Inhibitor+RIRI group were remarkably lower than those in the RIRI group (all P < 0.05). The expression level of CD206 protein in the Inhibitor+RIRI group was significantly higher than that in the RIRI group (P < 0.05). Conclusions PKC β inhibitor can alleviate the RIRI in rat models to certain extent, which may be correlated with the role of PKC β inhibitor in mitigating inflammatory cell infiltration in ischemic renal tissues and promoting the expression of alternatively activated macrophage

Dexmedetomidine hydrochloride up-regulates expression of hypoxia inducible factor-1α to alleviate renal ischemiareperfusion injury in diabetic rats / 南方医科大学学报

OBJECTIVE@#To verify whether dexmedetomidine hydrochloride (Dex) alleviates renal ischemia-reperfusion (IR) injury in diabetic rats by increasing the expression of hypoxia inducible factor-1 (HIF-1).@*METHODS@#A rat model of type 2 diabetes mellitus was established by high-fat diet and streptozotocin injection. The rats were subjected to daily intragastric administration of 0.05 mg/kg digoxin for 7 consecutive days and intraperitoneal injection of Dex 2 h before renal IR injury induced by ligation of the bilateral renal arteries for 60 min followed by reperfusion for 120 min. After reperfusion, blood samples were taken for detection of serum creatinine (Scr) and urea nitrogen (BUN) levels. Western blotting was used to detect the expression of HIF-1, cleaved caspase-3, Bcl-2, and Bax in the renal tissues; the expression of the HIF-1, p-eNOS, and eNOS were detected using ELISA. The percentage of apoptotic glomerular cells was assessed using TUNEL assay.@*RESULTS@#The levels of Scr, BUN, HIF-1, p-eNOS, and eNOS and the percentage of apoptotic cells in both normal and diabetic rats increased significantly after renal IR injury ( < 0.05). The expressions of Scr, BUN, p-eNOS, and eNOS decreased while HIF-1 expression increased significantly in Dex-treated rats with renal IR injury ( < 0.05). Compared with the non-diabetic rats, the diabetic rats showed more obvious increase in the expressions of Scr, BUN, p-eNOS, and eNOS following renal IR injury. In the diabetic rats with renal IR injury, Dex treatment prior to the injury significantly lowered the expressions of Scr, BUN, p-eNOS, eNOS, cleaved caspase-3, and Bax, decreased the percentage of apoptotic cells, and increased the levels of HIF-1a and Bcl-2 ( < 0.05). Digoxin treatment significantly antagonized the effects of Dex in the diabetic rats with renal IR injury by increasing the expressions of cleaved caspase-3 and Bax, promoting glomerular cell apoptosis, and decreasing renal expressions of HIF-1 and Bcl-2 ( < 0.05).@*CONCLUSIONS@#Dex alleviates renal IR injury in diabetic rats probably by inhibiting renal expression of HIF-1 and glomerular cell apoptosis.

Remifentanil alleviates renal ischemia/reperfusion injury by activating PI3K/Akt/eNOS pathway / 第二军医大学学报

Objective: To explore the effect and mechanism of intraoperative remifentanil (RF) on renal ischemia/reperfusion (I/R) injury. Methods: Fifty male C57/BL mice were randomly divided into 5 groups: sham group, I/R group, I/R+LY294002 (a phosphatidylinositol 3-kinase [PI3K] inhibitor) group, I/RRF group and I/R + RF+LY294002 group, with 10 mice in each group. Venous blood or renal tissue samples were collected from the mice of each group 6 h after I/R operation. The levels of blood urea nitrogen (BUN) and serum creatinine (SCr) were detected using automatic biochemical analyzer. The expression levels of PI3K/protein kinase B (Akt)/endothelial nitric oxide synthase (eNOS) pathway-related proteins in renal tissues of mice were detected using Western blotting. The aggregation of inflammatory cells was observed by H-E staining. The expression levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6 and IL-10 in renal tissues of mice were detected by enzyme-linked immunosorbent assay. The mRNA expression levels of anti-apoptotic factor Bcl2 and apoptotic factor Caspase-3 in renal tissues were determined by real-time quantitative PCR. Results: Compared with the sham group, the BUN and SCr levels in venous blood were increased in the I/R group, the PI3K expression, phosphorylated-Akt (p-Akt)/Akt ratio and phosphorylated-eNOS (p-eNOS)/eNOS ratio in renal tissues were decreased, the release levels of inflammatory factors (TNF-α, IL-1β, IL-6 and IL-10) were increased, Bcl2 mRNA expression was decreased, and Caspase-3 mRNA expression was increased; and the differences were significant (all P < 0.05). The mice of the I/R group had increased inflammatory cell recruitment in renal tissues. After RF treatment, the mice of the I/R + RF group had decreased levels of BUN and SCr in venous blood, increased PI3K expression, p-Akt/Akt ratio and p-eNOS/eNOS ratio in renal tissues, decreased release levels of inflammatory factors (TNF-α, IL-1β, IL-6 and IL-10), increased Bcl2 mRNA expression, and decreased Caspase-3 mRNA expression; and the differences were significant compared with the mice of the I/R group (all P < 0.05). The inflammatory cell recruitment was decreased in the I/R RF group. Moreover, compared with the mice of the I/RRF group, the mice of the I/RRF LY294002 group had increased levels of BUN and SCr in venous blood, decreased p-eNOS/eNOS ratio in renal tissues, increased IL-1β and IL-6 release, and increased Caspase-3 mRNA expression; and the differences were significant (all P<0.05). The inflammatory cell recruitment was increased in the I/R + RF + LY294002 group. Conclusion: RF exerts protective effect on kidney with I/R injury by alleviating renal inflammation and cell apoptosis through activating PI3K/Akt/eNOS pathway.

Study on the Effects of Prophylactic Administration of Ramulus mori Polysaccharides on Inflammatory Responses of Renal Ischemia Reperfusion Injury Model Mice and Its Mechanism / 中国药房

OBJECTIVE： To study on the effects of prophylactic administration of Ramulus mori polysaccharides （RMP） on inflammatory response of renal ischemia reperfusion injury （RIRI） model mice and to explore its possible mechanism. METHODS： Totally 60 C57BL/6 mice were randomly divided to sham operation group， model group， atorvastatin group （positive control， 15 mg/kg）， RMP low-dose， medium-dose and high-dose groups （300， 600， 1 200 mg/kg）. Except for sham operation group， RIRI model was induced in other 5 groups. 24 h before surgery， they were given relevant medicine intragastrically， once a day， for consecutive one week. 24 h after reperfusion， the mice were sacrificed. The serum levels of Scr and BUN were detected. The morphological changes of renal tissue were observed under optical microscope. The serum levels of IL-1β， IL-6， IL-10 and TNF-α were determined by ELISA. Western blot assay was used to determine the protein expressions of Toll-like receptor 4 （TLR4）， p38 mitogen-activation protein kinase （p38MAPK） and p-p38MAPK. RESULTS： Compared with sham operation group， the serum levels of Scr and BUN were significantly elevated in model group  （P＜0.01）. RIRI led to typical inflammatory response of renal tissue， widespread renal tubular epithelial cell degeneration and necrosis， and inflammatory cells infiltration. Serum levels of IL-1β， IL-6， IL-10 and TNF-α were increased significantly （P＜0.01）. The protein expressions of TLR4， p38MAPK and p-p38MAPK were increased significantly in renal cortex （P＜0.01）. Compared with model group， serum levels of Scr and BUN were decreased significantly in administration groups （P＜0.05 or P＜0.01）. The pathological damage of renal tissue was improved in varying degrees， especially in the RMP medium-dose and high-dose groups. Serum levels of IL-1β and IL-6 were decreased significantly in administration groups （P＜0.05 or P＜0.01）. Serum levels of IL-10 were further increased in atorvastatin group and RMP high-dose group （P＜0.01）， and serum level of TNF-α was decreased significantly in atorvastatin group and RMP medium-dose and high-dose groups （P＜0.05 or P＜0.01）. The protein expressions of TLR4 and p-p38MAPK in renal cortex were decreased significantly in administration groups （P＜0.05 or P＜0.01）. CONCLUSIONS： RMP prophylactic administration can improve RIRI of mice， the mechanism of which may be associated with relieving the inflammatory response through inhibition of TLR4/p38MAPK signaling pathway.

Study on Protective Mechanism of Panax Notoginseng Saponins on Rats with Renal Ischemia Reperfusion Injury Based on Klotho / 中国中医药信息杂志

Objective To investigate the effects of Panax Notoginseng saponins (PNS) on protein expression of Klotho in rats with renal ischemia reperfusion injury; To discuss its protective mechanism for model rats. Methods Experimental rats were randomly divided into sham-operation group, model group, positive medicine group, PNS high-, medium- and low-dosage groups. Each administration group was given relevant medicine for gavage, once a day. Renal ischemia reperfusion injury model was established. Rats were sacrificed by taking blood from abdominal aorta after 4 hours of modeling. Serum levels of blood urea nitrogen (BUN), creatinine (SCr), malondialdehyde (MDA) content in kidney tissue, superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity were measured. HE staining was used to observe the morphological changes of renal tissue. The protein expressions of Klotho and NF-κB p65 were measured by immunohistochemical method. Results Compared with the sham-operation group, the levels of BUN and SCr in the model group increased significantly (P<0.05); protein expression of Klotho in renal tissue decreased and the protein expression of NF-κB p65 increased (P<0.05). Compared with the model group, the expression of Klotho increased but protein expression of NF-κB p65 decreased in each administration group (P<0.05); Compared with the positive medicine group, the expression of Klotho in PNS high-dosage group increased but protein expression of NF-κB p65 decreased (P<0.05). The protein expression of NF-κB p65 was negatively related to protein expression of Klotho (r=-0.895, P<0.05). Conclusion PNS can inhibit oxidative stress and anti-inflammatory effects through upregulating protein expression of Klotho, and reduce the protein expression of NF-κB p65, and thus exerts renal protective effects.

Protective Effect of Fingolimod on Renal Ischemia Reperfusion Injury Model Mice and Its Mechanism Study / 中国药房

OBJECTIVE:To study the protective effect of fingolimod on renal ischemia reperfusion injury (RIRI) model mice and its mechanism.METHODS:A total of 60 mice were randomly divided into sham operation group,model group,fingolimod group (1 mg/kg) and fingolimod+wortmannin group [fingolimod 1 mg/kg+phosphatidylinositol 3-kinase (PI3K) specific blocker wortmarmin 1.4 mg/kg],with 15 mice in each group.Except for sham operation group,RIRI model was induced in other 3 groups,and those model mice were given relevant medicine via caudal vein at once 24 h before surgery.Serum of mice were collected in each group after 24 h perfusion.Serum levels of Scr and BUN were measured by automatic biochemical analyzer.The pathological changes of renal tissue were observed under light microscope.The protein expression of intercellular cell adhesion molecule-1 (ICAM-1),monocyte chemoattractant protein-1 (MCP-1) and phosphorylated protein kinase B (p-Akt) in renal tissue were measured by Western blot assay.RESULTS:Compared with sham operation group,the serum levels of Scr and BUN in model group were increased significantly (P＜0.01).Pathological changes were found in the kidney,and RIRI led to widespread renal tubular epithelial cell injury,apoptosis and inflammatory cells infiltration.The protein expression of ICAM-1 and MCP-1 in renal tissue were increased significantly (P＜0.01),the protein expression of p-Akt was increased slightly (P＞0.05).Compared with model group,other indexes of fingolimod group were improved significantly (P＜0.01) except that the protein expression of p-Akt in renal tissue was increased significantly (P＜0.01).Compared with fingolimod group,above indexes of fingolimod+wortmannin group were reversed (P＜0.05 or P＜0.01).CONCLUSIONS:Fingolimod can obviously ameliorate renal injury induced by RIRI in mice,the mechanism of which may be associated with the activation of PI3K/Akt signaling pathway.

Effect of 17β-estradiol on renal tubular cells apoptosis and inflammation induced by renal ischemia /reperfusion injury in rats / 临床与实验病理学杂志

Purpose To investigate the effects and mechanism of 17β-estradiol on the apoptosis and inflammation of renal tubular cells in rats with renal ischemia/reperfusion injury. Methods All the female Sprague-Dawley rats were ovariectomized and randomly divided into four groups: Control group, Sham group, I/R group and estrogen plus I/R (E2 + I/R) group (n = 8). Right kidney of the rat was excised and artery of the left kidney was blockaded for 45 min.24 h after the reperfusion, we collected the blood and nephridial tissue of each group. An automatic biochemical analyzer was used to measure the expression level of BUN and Cr in blood. Hematoxylin-eosin (HE) staining was used to observe the pathological changes and the degree of inflammatory reaction of the ischemia/reperfusion injury kidney. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) method was used to detect the apoptosis of renal tubular cells. The expression levels of Cleaved-Caspase-3 protein were measured by Western blot, while the numbers of CD4+ T lymphocyte infiltration in each group were tested by immunofluorescence (IF). Results Compared with the Sham group, expression level of BUN, Cr and Cleaved-Caspase-3 in I/R group significantly increased (P＜0.05) as well as the number of apoptotic cells (P＜0.05). In the meantime, inflammatory reaction significantly aggravated (P＜0.05) and the number of CD4 + T lymphocytes increased remarkably (P＜0.05). However, expression level of BUN, Cr and Gleaved-Caspase-3 in E2 + I/R group decreased significantly (P＜0.05) and the pathological damage in the kidney was alleviated (P＜0.05) compared with I/R group, furthermore, the number of apoptotic cells decreased (P＜0.05) compared with I/R group. The inflammatory reaction significantly blunted (P＜0.05) and the infiltration of CD4 + T lymphocytes decreased remarkably (P＜0.05) compared with I/R group. Conclusion Estrogen can inhibit the expression of Cleaved-Caspase-3 in renal tissue during ischemia/reperfusion injury and reduce the apoptosis of renal tubular cells. It can also reduce the infiltration of CD4 + T lymphocytes, thus playing a protective role on renal ischemia/reperfusion injury.

Cordyceps sinensis protects HK2 cells from ischemia-reperfusion injury through SirtⅠ pathway / 中南大学学报(医学版)

Objective:To investigate the effects of Cordyceps sinensis (CS) on cellular apoptosis and Sirt1 expression in HK2 cells followed by ischemia-reperfusion (I/R).Methods:HK2 cells were incubated with different concentrations of CS (10,20,40,80,160,320 mg/L) for 24 hours,and the optimal concentration of CS was selected by measuring cell proliferation.The confluent HK2 cells were incubated with 0.01 μmol/L antimycin A for 2 hours to induce ischemia in vitro,and then the reperfusion was achieved by incubating cells with glucose-replete complete growth medium for 24 hours.HK2 cells were divided into 4 groups:a control group,an I/R group,an I/R+CS (160 mg/L) group,and an I/R+CS (160 mg/L)+Sirtinol (25 μtmol/L) group.Twenty-four hours later,total RNA and protein were collected.The cell proliferation was evaluated by MTT assay;the mRNA and protein expression of Sirtl and the cleaved caspase-3 were measured by qRT-PCR and Western blot,respectively.The cellular apoptosis rate was determined by Annexin V-FITC/PI double staining and flow cytometry.Results:Certain concentrations (10-160 mg/L) of CS did not show effect on the proliferation of HK2 cells (P＞0.05),while 320 mg/L of CS inhibited cell proliferation significantly (P＜0.01);compared with the control group,the mRNA and protein expressions of Sirtl and the cleaved caspase-3 in the I/R group were up-regulated (P＜0.01) and the apoptosis rate was extremely high;compared with the I/R group,CS significantly up-regulated Sirt1 mRNA and protein expression (P＜0.01) while down-regulated cleaved caspase-3 mRNA and protein levels (P＜0.01),and reduced apoptosis rate (P＜0.05).The effects of CS were blocked in the presence of sirtinol,an inhibitor of CS.Conclusion:CS protects HK2 cells from I/R injury through activation of Sirt 1 pathway.

Effects of estrogen on the vasomotor function of rats' renal interlobar arteries and Cx43 expression after renal ischemia-reperfusion injury / 西安交通大学学报(医学版)

Objective To investigate the effect of estrogen (E2) on the connexin43 (Cx43) expression of renal interlobar arteries after renal ischemia-reperfusion injury (I/R).Methods The experiment was carried out in vivo using an SD rat I/R model.SD rats were randomly divided into normal group,sham-operation group,I/R group,and estrogen-intervention group.The functional changes of the kidney were analyzed after 24 hours of I/R;nephridial tissue section was stained by hematoxylin-eosin (HE),and Paller scores were used to evaluate the degree of kidney damage.Pressure myography was utilized to detect the vasomotor function of renal interlobar arteries.Immunofluorescence technique,qRT-PCR and Western blot were applied to determine the expression of Cx43 in renal interlobar arteries in different groups.Results Estrogen markedly decreased the levels of Cr and BUN in the serum of I/R rats (P＜0.05),and the damage of the kidney tissue could be improved noticeably.The vasomotor rate of renal interlobar arteries was (24.80 ± 3.70)％ after I/R and (41.60 ± 3.50)％ after treatment with estrogen,which was higher than that of I/R group (P＜0.05).The expression of Cx43 was lower in renal interlobar arteries of estrogen-intervention group than that in I/R group (P＜0.01).Conclusion Estrogen may reduce vascular tension and boost dilation of the artery by inhibiting Cx43 expression and GJ function.Therefore,estrogen may attenuate the damage of I/R and improve renal function.

Effects of propofol on the expression of gap junction Cx43 in renal arteryin rats with renal ischemia reperfusion injury / 西安交通大学学报(医学版)

Objective To observe the effects of propofol intervention on renal ischemia-reperfusion injury on the expression of Cx43 in rat renal interlobar artery.Methods Male SD rats were randomly divided into control 4h and 24h groups (control), sham operation 4h and 24h groups (sham), ischemia reperfusion 4h and 24h groups (I/R), propofol 4h and 24h groups (propofol), and fat emulsion 4h and 24h groups (intralipid).Ischemia/reperfusion model was prepared by resection of right kidney and noninvasive arterial occlusion of left kidney, with renal ischemia for 45min and reperfusion for 4h or 24h depending on different group.Serum urea nitrogen (BUN) and creatinine (Cr) were detected by automatic biochemical analyzer.HE staining was used to observe the pathological changes of renal tissue.The changes of renal artery systolic and diastolic lobes were examined by pressure myographic technique.The expression of Cx43 protein in renal interlobar artery was analyzed by Western blot.Results The concentrations of serum BUN and Cr in sham group did not differ significantly from those in the blank control group.Renal HE staining showed no significant lesions;the pressure myogram of motor renal interlobar artery contraction rate showed no significant difference.The expression of Cx43 protein did not change significantly.Compared with sham operation group, the concentrations of serum BUN and Cr in ischemia-reperfusiongroup were significantly increased.HE slices kidney showed that the pathological changes of renal tissue became obvious;pressure motor indicated renal interlobar artery contraction rate was decreased;the expression of Cx43 protein was increased significantly (P<0.05).Compared with ischemia-reperfusion group, the concentrations of serum BUN and Cr in propofol group were decreased;renal HE slices showed reduced renal tissue lesions, increased renal interlobar artery contraction rate, and decreased expression of Cx43 protein (P<0.05).Conclusion Propofol can change renal ischemia-reperfusion injury by reducing the expression of Cx43 protein in vasomotor in renal interlobar artery.

Research on preventative role of Nrf2 in kidney diseases / 中国药理学通报

Nrf2,a key transcriptional factor in regulating endog-enous antioxidant signaling pathway,maintains the redox bal-ance by controlling the expression of a battery of antioxidant en-zymes,phase-Ⅱ detoxification enzymes and phase-Ⅲ transport-ers.Furthermore,Nrf2 regulates inflammation.Recent resear-ches have confirmed that Nrf2 provides a vital physiological role in kidney diseases,activation of Nrf2 enhances the antioxidant and anti-inflammatory ability in cellular and tissue levels,thusalleviates renal injury.Here,this article aims to summarize the protective effect of Nrf2 on various models of kidney impairment and explore the potential of Nrf2 as a therapeutic target to pre-vent kidney diseases.

Effect of Grape Seed Procyanidins on Protein Expressions of Caspase-3 and TRAF6 in Renal Tissue of Rats with Renal Ischemia-reperfusion Injury / 中国药房

OBJECTIVE:To study the effect of grape seed procyanidins on protein expressions of cysteine aspartic protease 3 (Caspase-3), tumor necrosis factor-related receptors (TRAF6) in renal tissue of rats with renal ischemia-reperfusion injury (RIRI),and explore the protective mechanism of procyanidins on RIRI. METHODS:50 rats were randomly divided into sham op-eration group,model group,Shenfukang capsules group(positive control,600 mg/kg),procyanidins low-dose,high-dose groups (100,150 mg/kg),10 in each group. All rats were intragastrically administrated once a day,for 7 d. After administration,rats in other groups except for sham operation group were established the RIRI model.After the modeling successed of 24 h,levels of creati-nine(Cr),urea nitrogen(BUN)in serum,and protein expressions of Caspase-3,TRAF6 in renal tissue of rats in each group were detected,and apoptotic rate of renal tubular epithelial cells was determined. RESULTS:Compared with sham operation group,lev-els of Cr,BUN in serum in model group were significantly increased(P<0.05);protein expressions of Caspase-3,TRAF6 in re-nal tissue were obviously enhanced (P<0.05);apoptotic rate of renal tubular epithelial cells was obviously increased (P<0.05). Compared with model group,levels of Cr,BUN in serum in each administration group were obviously decreased(P<0.05);pro-tein expressions of Caspase-3,TRAF6 in renal tissue were obviously weakened(P<0.05);apoptotic rate of renal tubular epithelial cells was obviously decreased(P<0.05);and procyanidins high-dose group showed superior effect to low-dose group and Shenfu-kang granules group (P<0.05). CONCLUSIONS:Grape seed procyanidins can relieve the RIRI of rats,which may be achieved by reducing protein expressions of Caspase-3 and TRAF6 to inhibit the apoptotic rate of renal tubular epithelial cells.

Effects of simvastatin on expression of Bcl-2 and Bax in myocardium of rats with renal ischemia-reperfusion injury / 中国病理生理杂志

AIM:To observe the effect of simvastatin on myocardial tissue after renal ischemia-reperfusion in-jury and its mechanism .METHODS:A rat model of renal ischemia-reperfusion injury was prepared by clamping the bilat-eral renal arteries for 45 min.The rats (n=36) were randomly divided into sham operation group , renal ischemia-reperfu-sion (I/R) group and simvastatin group with 12 rats in each group.The content of serum creatinine (SCr), blood urea ni-trogen ( BUN) and myocardial tissue malondialdehyde ( MDA) , the myocardial activity of lactate dehydrogenase ( LDH) , creatine kinase (CK) and superoxide dismutase (SOD), and the myocardial protein expression of Bcl-2 and Bax were de-tected.RESULTS:Compared with sham operation group , the content of SCr , BUN and myocardial MDA , and the myo-cardial activity of LDH and CK in I/R group were significantly increased (P<0.05), and the activity of SOD was signifi-cantly decreased (P<0.05).Compared with I/R group, the content of SCr, BUN and myocardial MDA, and the myocar-dial activity of LDH and CK in simvastatin group were significantly decreased ( P<0.05 ) , while SOD activity was en-hanced (P<0.05).The protein expression of Bcl-2 and Bax in sham operation group was less than that in I/R group (P<0.05), and the protein level of Bax in simvastatin group was significantly lower than that in I /R group (P<0.05), while the protein level of Bcl-2 was increased (P<0.05).CONCLUSION:Simvastatin has a protective effect on the my-ocardium of the rats with renal ischemia-reperfusion injury , and the protective mechanism may be related to the elimination of free radicals by simvastatin , increase in the protein expression of Bcl-2 and decrease in the protein expression of Bax .

Apoptosis and Histopathology of the Heart after Renal Ischemia-Reperfusion in Male Rat Running title: Ischemia-Reperfusion Injury

ABSTRACT Ischemia-reperfusion injury was seen in strokes, myocardial infarctions, acute kidney injury, mesenteric ischemia, liver and systemic shock. Renal ischemia-reperfusion is more importance in the setting of kidney transplantation that affects distant organs. In this study forty Male Albino Wistar rats (200-250g) were randomly divided in four group (n=10) including control, sham operation group, nephrectomy and IRI group. All rats anesthetized with intraperitoneal injection of ketamine (50 mg/kg) and xylazine (10 mg/kg) and maintained the core body temperature at approximately 37°C. For inducing IRI group, it was performed right nephrectomy, and in continuing, the left kidney pedicle occluded to 45 min via nontraumatic microvascular clamp for making ischemia that followed 24 hours reperfusion. TUNEL assay was used to detect the cardiac apoptotic cells. Hematoxylin-Eosin staining and periodic acid-Schiff (PAS) procedure was used to histopathological assessment and glycogen accumulation respectively. There was more heart damage at 24 h reperfusion in IRI group. Renal IRI group showed myocardial degeneration, necrosis and increasing connective tissue in myofibril. There were apparent hypertrophy and swelling of myofibril, fragmentation and vacuolization of sarcoplasm. In addition, it was shown elevated apoptotic cell at 24 hours reperfusion in renal IRI group than sham group. There were increases of glycogen accumulation in cardimyocyte of renal IRI group. Our findings suggest that renal IRI-induced cardiac damage, accompanied by an accumulation of glycogen granules, induced apoptosis and histological changes in cardiomyocytes.

The optimal duration of ischemic preconditioning for renal ischemia-reperfusion injury in mice

PURPOSE: The aim of the present study was to investigate the protective effects of ischemic preconditioning for different periods of time and to elucidate the optimal safe ischemic preconditioning time for renal ischemia-reperfusion (I/R) injury in mice. METHODS: A total of 25 male C57BL/6 mice were randomly divided into 5 groups (sham, I/R, ischemic preconditioning [IP]-3, IP-5, and IP-7 groups), in which the kidney was preconditioned with IP of various durations and then subjected to I/R injury (the last 3 groups). To induce renal ischemia, the left renal pedicle was occluded with a nontraumatic microaneurysm clamp for 30 minutes followed by reperfusion for 24 hours. The effects of IP on renal I/R injury were evaluated in terms of renal function, tubular necrosis, apoptotic cell death and inflammatory cytokines. RESULTS: Results indicated that BUN and creatinine (Cr) levels increased significantly in the I/R group, but the elevations were significantly lower in IP groups, especially in the IP-5 group. Histological analysis revealed that kidney injury was markedly decreased in the IP-5 group compared with the I/R group, as evidenced by reduced renal necrosis/apoptosis. In addition, IP significantly inhibited gene expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and chemokines (monocyte chemoattractant protein-1). Western blot analysis indicated that the expression levels of Toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) were upregulated in the I/R group, while expression was inhibited in the IP groups. CONCLUSION: Five-minute IP had the greatest protective effect against I/R injury.

Effect of Complement C5a/C5aR pathway on autophagy induced by renal ischemia-reperfusion injury / 中华器官移植杂志

Objective To investigate the expression of autophagy and the effect of complement C5a/C5aR pathway on autophagy induced by renal ischemia reperfusion injury (IRI).Methods MaleWT and C5aR gene knockout (BALB/C background) mice were selected.The model of renal IRI was established by occluding bilateral renal pedicles with microaneurysm clamps.Mice were divided into wild type BALB/C (WT) group and C5aR gene knock out (C5aRKO) group.The pathology of kidney was assessed by HE staining.The levels of BUN and KIM-1 were detected 24 h after reperfusion.The expression of the autophagy-associated protein (LC3 Ⅱ/LC3 Ⅰ and P62) was measured by Western blotting and immunofluorescence.In vitro,human renal tubular epithelial cells (HK2) were cultured.The expression of LC3 in HK2 cells was investigated by immunofluorescence and Western blotting after being treated with recombinant C5a or C5a combined with C5aR antagonist (C5aRA).Results As compared with WT group,the severity of kidney injury was obviously reduced in C5aRKO group (P＜0.05).After ischemia-reperfusion,the expression of autophagy-related protein LC3 gradually increased with the reperfusion time prolonged.The level of autophagy induced by ischemia-reperfusion was significantly reduced in C5aRKO group as compared with WT group (P＜0.05).In addition,the expression of autophagy-related protein LC3 Ⅱ in HK2 cells was increased with the augment of C5a stimulation concentration in vitro.Blockage of C5aR pathway by C5aRA led to a significant decrease in autophagy (P ＜ 0.05).Conclusion Complement C5a/C5aR pathway promotes renal IRI-induced autophagy.

Establishment of Cardio-renal Syndrome and the mRNA Expression of Pro-renin Receptor in Experimental Rat’s Model / 中国循环杂志

Objective: To establish the cardio-renal syndrome (CRS) model by coarctation of abdominal aorta (CAA) with renal ischemia reperfusion injury (RIRI), and to observe the mRNA expression of pro-renin receptor [(P)RR] in experimental rats. Methods: A total of 42 Wistar rats were randomly divided into 4 groups: Sham group, CAA group, RIRI group and CAA+RIRI group.n=10 in each group, 2 rats died during the modeling and all animals were treated for 16 weeks. Blood levels of BNP, creatinine (Cr), urea nitrogen (BUN), the activity of rennin, the contents of angiotensin-I (AT-I), AT-II and aldosterone were examined by laboratory test. The diastolic end inter-ventricular septum thickness (DEIVST), DELVPT, LVEF, ventricular weight index (VWI) and cardiac weight index were detected by small animal echocardiography. The histological changes of myocardium and kidney tissue were measured by HE staining, and the mRNA expressions of pro-renin receptor in myocardium and kidney tissues were measured by RT-PCR. Results: Compared with Sham group, blood levels of BNP were increased in the other 3 groups,P0.05. Compared with CAA group, CAA+RIRI group had more obvious changes of DEIVST and LVEF,P<0.01. Compared with RIRI group, CAA+RIRI group had more obvious ventricular hypertrophy, higher VWI and cardiac weight index, allP<0.05. HE staining presented that CAA+RIRI group had broadening of myocardial cell bundle space, decreased left renal index, severe tubular atrophy and partial glomerular atrophy. RT-PCR demonstrated that compared with Sham group, the mRNA expressions of pro-renin receptor in myocardium and kidney tissues were decreased in the other 3 groups. Conclusion: Combined CAA+RIRI method may damage the cardial and renal tissues at the same time which was more severe than either CAA or RIRI. While CAA+RIRI model has better controllability and higher consistency that provides a methodological reference for pro-renin receptor in treating CRS in experimental rat’s model.