Prevention of renal ischemic reperfusion injury using FTY 720 and ICAM-1 antisense oligonucleotides

BACKGROUND: Renal damage secondary to ischemia-reperfusion injuries (I-R) is frequent in organ transplantation and adversely affects the graft survival. An important component of this damage is caused by initial adhesion of neutrophils and lymphocytes to endothelial cells. FTY 720, which induces lymphopenia, has previously been shown to display protective effects in models of I-R. The purpose of the present study was to evaluate the combination of FTY 720 and intracellular adhesion molecule and ICAM-1 antisense oligonucleotides (AS-oligos), an agent designed to block the adhesion process. METHODS: Sprague-Dawley rats underwent syngenic kidney transplantation after donor kidneys had been preserved in cold solution for 2 hours. The treatment groups included: (1) FTY 720 (1 mg/kg) before reperfusion, (2) AS-oligos (2 mg/kg) during kidney perfusion, and (3) the combination of FTY 720 and AS-oligos. All animals were followed daily after transplantation; some were sacrificed on the second day for histologic analysis. RESULTS: All treated groups showed a maximal serum creatinine that was significantly less than the control (group 1: 2.76 +/- 1.4, group 2: 2.44 +/- 2.05, group 3: 1.51 +/- 0.42, and control: 4.04 +/- 0.5; P <.01) and returned to the basal value earlier. Also, treated animals showed less histologic stigmata of acute tubular damage. FTY 720 and AS-oligos used in combination showed a mild additive effect. CONCLUSIONS: The use of FTY 720 and/or AS-oligos significantly prevents functional renal damage secondary to I-R, displaying a mild additive effect in this model. Both agents offer the advantage of use during the donor and the graft operations.     

The effect of dexmedetomidine against oxidative and tubular damage induced by renal ischemia reperfusion in rats

Abstract

Dexmedetomidine (dex) is a potent, highly selective and specific α2-adrenoreceptor agonist. This experimental study was designed to investigate protective and therapeutic effect of two different doses of dex, on kidney damage induced by ischemia-reperfusion (I/R) in rats. Male Sprague?Dawley rats were divided into four groups, each including 10 animals: control group, ischemia-reperfusion (I/R) group; treated groups with 10?μg/kg of dex and 100?μg/kg of dex. After removing right kidney of the rats, the left kidney has performed ischemia during 40?min and reperfusion in the following 3?h. The histopathological findings, and also tissue superoxide dismutase (SOD) and catalase (CAT) enzyme activity, malondialdehyde (MDA), glutathione (GSH), serum blood urea nitrogen (BUN), creatinine (Cre) and tumor necrosis factor-alpha (TNF-α) levels were determined. In the I/R group, compared to the control group, levels of BUN, Cre and kidney tissue MDA have increased significantly, SOD, CAT enzyme activity and glutathione levels have decreased significantly. In the dex10 group, compared to the I/R group, levels of Cre and TNF-α have decreased significantly, while the SOD activity has increased significantly. In the dex100 group, compared to the I/R group, levels of BUN, Cre have decreased significantly, while the SOD activity has increased significantly. In the I/R group, there was also extensive tubular necrosis, glomerular damage in the histological evaluation. Dex ameliorated these histological damages in different amounts in two treatment groups. In this study, the protective effects of dex against renal I/R injury have been evaluated by two different amount of doses.     

Prevention of ischemic damage using controlled limb reperfusion

Following prolonged limb ischemia, a reperfusion injury may occur with the reintroduction of unmodified blood, resulting in tissue loss and, in severe cases, limb loss. We have shown that the reperfusion injury in the heart can be minimized by using controlled reperfusion with a substrate-enriched cardioplegia solution prior to restoring normal blood flow. This article describes two clinical cases in which we used controlled reperfusion in an ischemic limb to prevent limb loss. It demonstrates that a controlled, substrate-enhanced, hypocalcemic, leukodepleted, modified blood reperfusate solution can minimize limb reperfusion damage and improve functional recovery. This preliminary experience is presented to familiarize surgeons with this form of treatment and to describe the solutions and method of administration that can be used to avoid the devastating complications of severe limb ischemia.     

Effect of apelin hormone on renal ischemia/reperfusion induced oxidative damage in rats

Apelin is a peptide hormone defined as a ligand for G-protein clamped receptor (APJ) receptor. It is indicated in the literature both apelin and APJ are synthesized on the peripheral tissues including the renal tissues. Which roles does the apelin play on the renal tissue has not been completely illuminated yet. This study is designed to determine the possible protective effect of apelin-13 on the kidney I/R injury. Adult male Sprague-Dawley rats were used in this study. In the sham group, right kidneys of the animals were dissected. In the I/R group, right kidney was dissected and ischemia of 45?min was performed, and then reperfusion was applied for 3?h. In the treatment groups, three different doses of apelin were injected at the beginning of the ischemia unlike the I/R group. BUN, Cre, Na, K, Cl, total protein and albumin from serum samples were determined and TNF-α, IL-1β, IL-6, TAS and TOS parameters were read with ELISA reader. MDA, SOD, CAT and GSH-Px enzyme activations from renal tissues were measured. In comparison with the sham and I/R groups, while the serum BUN, CRE, CI and TNF-α levels showed an increase in the groups on which the apelin-13 was applied, Na, total protein, albumin, TAS levels decreased. Serum TOS level of other groups showed an increase by comparison with the sham group. Our results showed that apelin-13 applied after I/R increased the antioxidant enzyme activity in a dose dependent manner, prevented the lipid oxidation and improved the renal functions.     

钠-氢交换蛋白1小干扰RNA对抗霉素A诱导人肾小管上皮细胞缺血再灌注损伤的保护机制

目的 通过构建钠-氢交换蛋白1（NHE-1）小干扰RNA (siRNA)抑制肾小管上皮细胞NHE-1的表达，探讨其对细胞缺血再灌注损伤的保护作用机制。 方法 根据人NHE-1全长基因序列设计并合成NHE-1-siRNA，转染人肾小管上皮细胞系（HKC），以无关siRNA转染组作为对照。利用10 μmol/L 抗霉素A诱导细胞来模拟缺血缺氧环境。用RT-PCR、Western印迹法检测NHE-1的表达。用BCECF/AM、Fluo-3/AM和SBFI-AM标记HKC，通过激光共聚焦显微镜分别检测其细胞内pHi、Ca2+和Na+浓度的变化。用Hoechst 33342染色技术及Annexin V/PI 染色结合流式细胞仪技术检测细胞凋亡情况。利用荧光探针JC-1检测细胞线粒体膜电位的变化。 结果 特异性NHE-1-siRNA能有效抑制HKC的NHE-1表达，与无关siRNA转染组相比，NHE-1-siRNA转染组NHE-1 mRNA和蛋白表达水平明显下调(均P < 0.05)。抗霉素A刺激后，2组细胞NHE-1 mRNA及蛋白表达水平显著上调，而NHE-1-siRNA转染组低于无关siRNA转染组；同时NHE-1-siRNA转染组细胞凋亡率（8.9%±2.9%）明显低于抗霉素A处理组（18.8%±3.2%）和抗霉素A+无关siRNA转染组（17.4%±3.6%）（均P < 0.05）；NHE-1-siRNA转染组线粒体膜电位明显增高；与无关siRNA转染组相比较，NHE-1-siRNA转染组经抗霉素A处理后，细胞内钠离子、氢离子及钙离子增高的幅度较低（P < 0.05）。 结论 NHE-1-siRNA可抑制肾小管上皮细胞内NHE-1的表达，对抗霉素A诱导肾小管上皮细胞的缺血再灌性损伤有一定的保护作用。其机制可能通过抑制NHE-1表达，延缓细胞内Na+的积聚，减轻细胞内钙离子的超载，抑制损伤细胞的线粒体膜电位下降，减少细胞的凋亡。     

Growth factor Midkine is involved in the pathogenesis of renal injury induced by protein overload containing endotoxin

Background

Growth factor Midkine (MK), which expresses on endothelial cells and renal proximal tubules, has been implicated in inflammation-related kidney diseases such as ischemic reperfusion-induced tubulointerstitial injury and diabetic nephropathy. The biological actions of MK are elicited through its chemotactic activity and chemokine-driven inflammatory pathway. Post-infectious glomerulonephritis is caused by the deposition of immune complexes into glomeruli by infiltrating a number of inflammatory cells. Therefore, we investigated whether MK might be involved in the pathogenesis of acute glomerulonephritis.

Methods

We induced endocapillary proliferative glomerulonephritis in 129/SV mice using intraperitoneal injections of a large amount of protein.

Results

In contrast to mice deficient in MK (Mdk ??em>/??/sup>), Mdk ^+/+ mice induced by protein overload demonstrated more diffuse cellular proliferation in the mesangial areas and capillary lumens, eventually leading to glomerular damage and tubulointerstitial injury. This pathological observation could be attributable to neutrophil infiltration through the chemotaxis and stimulation of the MK-macrophage inflammatory protein (MIP)-2 pathway, but appeared to be due to the MK-related immunoglobulin (Ig)G deposition and C3 activation. These findings are often seen in infectious-related glomerular injury. Furthermore, the profile of MK expression was strongly consistent with that of glomerular damage and tubulointersititial injury.

Conclusion

This study might provide a new insight into understanding the deleterious role of MK in endocapillary proliferative glomerulonephritis induced by protein overload.     

Myoglobinuria exacerbates ischemic renal damage in the dog

The effects of intramuscular glycerol on ischemic acute renal failure was investigated in dogs. Anesthetized dogs received a bilateral 120-min renal artery obstruction (RAO) alone, RAO plus 5 ml/kg of 50% glycerol or RAO plus 5 ml/kg of 75% glycerol. Control groups received the glycerol injection, but not RAO. Renal histopathology was minimal in dogs receiving glycerol alone. In RAO dogs, those receiving 50% glycerol showed diffuse acute tubular necrosis (ATN), while those receiving 75% glycerol had severe ATN with extreme mortality. Changes in serum creatinine, creatinine clearance, and fractional excretion of sodium were consistent with the histopathologic changes. We conclude that myoglobinuria, of a degree insufficient to cause renal failure itself, can interact with renal ischemia to significantly exacerbate the renal damage produced.     

Reduction of renal reperfusion damage following warm ischemia by allopurinol and superoxide dismutase

Preserved organs are damaged not only by the ischemic injury due to lack of oxygen. The reperfusion injury mediated by oxygen free radicals is an important factor in the postischemic organ failure. The prevention of free radical-induced reperfusion injury with allopurinol (AP) and superoxide dismutase (SOD) is shown in a warm ischemia kidney model. Rats were treated with allopurinol (40 mg/kg i.v.) one hour, or with SOD (20,000 IU/kg i.v.) one minute before reperfusion after a period of 35 minutes of warm ischemia. Allopurinol and SOD reduced significantly the postischemic kidney failure with a less important increase of creatinine. Creatinine levels on day three in the control group: 517 +/- 87 mumol/ml, in the SOD-group: 206 +/- 105 mumol/ml, and in the AP-group: 163 +/- 81 mumol/ml (anal. of variance: p = 0.0001). AP has a wide therapeutic range. We feel, that it is important to confirm the prevention of reperfusion injury by allopurinol prophylaxis clinically.     

缺血后处理对肾缺血再灌注损伤的抑制作用及对细胞凋亡的影响

目的 观察缺血后处理对大鼠急性.肾缺血再灌注损伤的抑制作用及其对细胞凋亡的影响.方法 建立原位大鼠单侧肾缺血再灌注动物模型,摘除右肾后对左肾行缺血后处理,即10 s再灌注,10 s缺血,6次循环后再灌注24 h.全自动生化分析仪检测血尿素氮(BUN)和肌酐(Cr)含量,比色法测定血浆中脂质过氧化产物丙二醛(MDA)和超氧化物歧化酶(SOD)含量,免疫组织化学法观察肾组织中细胞色素C的表达,流式细胞术检测细胞凋亡率,免疫印迹法(Western blot)检测胞浆中细胞色素C的含量.结果 肾缺血再灌注24 h后,血中BUN、Cr和MDA明显增高,肾细胞凋亡率明显增加.移植肾经缺血后处理,血中BUN、Cr和MDA含量均降低,SOD含量升高,细胞色素C释放减少,肾细胞凋亡率明显降低.结论 缺血后处理可以减轻移植肾脂质过氧化反应,减少肾细胞凋亡率,减轻肾缺血再灌注损伤.     

Protective effects of vitamin E against liver damage caused by renal ischemia reperfusion

Abstract

Recent studies have reported that remote organs are affected by renal ischemia reperfusion (IR). The present study investigates the role of vitamin E on the liver damage after renal IR. First, male mice were subjected to three groups (n?=?9): 1) sham-operated, (2) renal IR (45?min ischemia), (3) renal IR?+?Vitamin E (150?mg/kg trough feeding tube for 28?d). After 24?h of reperfusion, animal were anesthetized for sample collections. Liver tissues malondialdehyde (MDA) increased and total glutathione (GSH) concentration decreased in the IR group compared to the sham group. Vitamin E consumption diminished the IR-induced increase in plasma AST and ALT. In addition, Vitamin E inhibited the IR-induced decrease in GSH activity and diminished IR-induced increase in MDA concentration. These findings showed that vitamin E consumption partly inhibited the IR-induced liver damage.     

存活素反义寡核苷酸诱导肾癌细胞凋亡及机制的实验研究

目的观察存活素反义寡核苷酸封闭存活素的表达对肾癌细胞凋亡的影响。方法采用脂质体介导的存活素反义寡核苷酸技术转染肾癌细胞786-0。电镜观察细胞超微结构,免疫组织化学、Western blot及RT-PCR方法检测存活素蛋白及mRNA表达,流式细胞仪检测细胞凋亡率,四甲基偶氮唑盐比色法检测癌细胞抑制率。酶标免疫测定caspase-3活性。结果存活素反义寡核苷酸能显著降低存活素蛋白和mRNA的表达,并呈浓度和时间依赖效应。转染后的肾癌细胞出现了大量凋亡小体。400、600、800 ng／ml反义寡核苷酸细胞凋亡率分别为（10．54±0．72）％,（12．80±0．38）％,（22．30±1．23）％,较空白对照组[（6．05±0．48）％]和正义对照组[（5．70±0．41）％]显著增加（P〈0．05）。反义寡核苷酸各组caspase-3的相对活性分别为0．052±0．009,0．078±0．004和0．092±0．002,与空白对照组（0．027±0．008）和正义对照组（0．028±0．001）相比,差异有统计学意义（P〈0．05）。结论存活素反义寡核苷酸能显著下调存活素基因表达,明显促进肾癌细胞786-0凋亡并抑制其增殖;可能是通过上调caspase-3表达来促进凋亡。     

Prevention of renal damage by alpha tocopherol in ischemia and reperfusion models of rats

Ischemia-reperfusion injury in rat kidneys most probably comes from oxidative stress, but the possible preventive effect of alpha-tocopherol (AT) treatment on this injury has not yet been established. Forty male Wistar rats were randomly divided into four groups. The left renal arteries of all rats except the controls were clamped to induce renal ischemia. The left kidneys of the rats in the ischemia group were removed following 40 min ischemia. The rats in the ischemia-reperfusion and ischemia-reperfusion-AT groups were treated similarly, but in these groups the renal arteries were re-perfused for 1 h following ischemia. The rats in the ischemia-reperfusion-AT group also received 10 mg/kg AT 3 h prior to ischemia. The specimens were examined histopathologically and ultrastructurally, and the tissue calcium levels were measured. Light microscope and ultrastructural examination showed that the greatest damage occurred in the ischemia-reperfusion group. The highest level of tissue calcium was also found in this group. In the ischemia-reperfusion-AT-treated group, less tissue damage and a lower tissue calcium concentration was found compared to both the ischemia and ischemia-reperfusion groups. Our results indicate that AT can reduce tissue damage after ischemia-reperfusion injury.