Melatonin protects kidney grafts from ischemia/reperfusion injury through inhibition of NF-kB and apoptosis after experimental kidney transplantation

Abstract:  Free radicals are involved in pathophysiology of ischemia/reperfusion injury (IRI). Melatonin is a potent scavenger of reactive oxygen and nitrogen species. Thus, this study was designed to elucidate its effects in a model of rat kidney transplantation. Twenty Lewis rats were randomly divided into 2 groups (n = 10 animals each). Melatonin (50 mg/kg BW) dissolved in 5 mL milk was given to one group via gavage 2 hr before left donor nephrectomy. Controls were given the same volume of milk only. Kidney grafts were then transplanted into bilaterally nephrectomized syngeneic recipients after 24 hr of cold storage in Histidine–Tryptophan–Ketoglutarate solution. Both graft function and injury were assessed after transplantation through serum levels of blood urea nitrogen (BUN), creatinine, transaminases, and lactate dehydrogenase (LDH). Biopsies were taken to evaluate tubular damage, the enzymatic activity of superoxide dismutase (SOD) and lipid hydroperoxide (LPO), and the expression of NF-kBp65, inducible nitric oxide synthase (iNOS), caspase-3 as indices of oxidative stress, necrosis, and apoptosis, respectively. Melatonin improved survival ( P  < 0.01) while decreasing BUN, creatinine, transaminases, and LDH values up to 39–71% ( P  < 0.05). Melatonin significantly reduced the histological index for tubular damage, induced tissue enzymatic activity of SOD while reducing LPO. At the same time, melatonin down-regulated the expression of NF-kBp65, iNOS, and caspase-3. In conclusion, donor preconditioning with melatonin protected kidney donor grafts from IRI-induced renal dysfunction and tubular injury most likely through its anti-oxidative, anti-apoptotic and NF-kB inhibitory capacity.     

葛根素对臂丛神经根性撕脱伤脊髓前角iNOS、CGRP蛋白表达及PI3K/Akt信号通路的影响

目的　探讨葛根素对臂丛神经根性撕脱伤（brachial plexus root avulsion injury,BPRAI）脊髓前角iNOS、CGRP蛋白表达及PI3K/Akt信号通路的影响。 方法　将50只雄性SD大鼠随机分为正常组、模型组、葛根素低、中、高剂量治疗组,每组10只。模型组,葛根素低、中、高剂量治疗组进行BPRAI造模,撕脱大鼠右侧C5~7脊神经前根,后根剪断,术后3个治疗组予腹腔注射葛根素,剂量分别为50、100、200 mg·kg-1·d-1,正常组、模型组腹腔注射等体积生理盐水,持续4周。采用尼氏染色、免疫荧光化学、Western blot方法,观察损伤侧脊髓前角α运动神经元（alpha motorneurons,α-MNs）的存活率,iNOS、CGRP、PI3K/Akt通路相关蛋白的表达。 结果　第4周时,低、中、高剂量的葛根素治疗可抑制α-MNs丢失（P<0.05或P<0.01）;中、高剂量的葛根素治疗可抑制iNOS表达（P<0.05）;高剂量的葛根素治疗可促进CGRP蛋白表达（P<0.05或P<0.01）;低、中、高剂量葛根素均可显著抑制p-Akt1/2/3表达（P<0.01）。 结论　葛根素可改善BPRAI造模引起的α-MNs死亡,其机制可能与葛根素能抑制iNOS蛋白的表达、促进CGRP蛋白的表达有关,并且PI3K/Akt信号通路参与其调控。     

The Role of Oxidative Stress in Aseptic Loosening of Total Hip Arthroplasties

This study investigated the hypothesis that wear particle-induced oxidative stress initiates osteolysis after total hip arthroplasty (THA). Patient radiographs were scored for osteolysis and periprosthetic tissues were immunostained and imaged to quantify polyethylene wear, inflammation, and five osteoinflammatory and oxidative stress-responsive factors. These included high mobility group protein-B1 (HMGB1), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), 4-hydroxynonenal (4-HNE), and nitrotyrosine (NT). The results show wear debris correlated with inflammation, 4-HNE, NT and HMGB1, whereas inflammation only correlated with NT and HMGB1. Similar to wear debris and inflammation, osteolysis correlated with HMGB1. Additionally, osteolysis correlated with COX2 and 4-HNE, but not iNOS or NT. Understanding the involvement of oxidative stress in wear-induced osteolysis will help identify diagnostic biomarkers and therapeutic targets to prevent osteolysis after THA.     

iNOS和VEGF在子宫内膜异位症的表达

目的:研究诱导型一氧化氮合成酶(iNOS)、血管内皮生长因子(VEGF)在子宫内膜异位症(EMs)的异位内膜的表达.方法:采用免疫组织化学方法分别检测30例EMs异位内膜与35例正常对照组子宫内膜组织中iNOS、VEGF的表达,了解异位内膜组织中iNOS、VEGF表达的相关性.结果:在EMs的异位内膜组织中,iNOS和VEGF蛋白的表达明显高于正常子宫内膜组织的表达;在EMs异位子宫内膜组织中,iNOS和VEGF的表达成正相关(r=0.895,P＜0.05).结论:EMs中,异位内膜组织的侵袭力增强及血管生成可能与iNOS、VEGF高表达有关.     

褪黑素对大鼠脊髓损伤后iNOS表达的影响

目的：探讨褪黑素对大鼠脊髓损伤后诱生型一氧化氮合酶（iNOS）表达的影响。方法：采用改良Allen’S撞击法制备脊髓损伤模型;成年SD大鼠110只随机分为假损伤组、损伤组和药物治疗组3组,其中损伤组和药物治疗组各50只,分5个时间点（8小时、24小时、72小时、7天、14天）处死;假损伤组10只,于手术后14天处死,采用HE染色和免疫组化检测脊髓损伤后脊髓组织中iNOS蛋白的表达。结果：与损伤组比较,药物治疗组大鼠损伤后脊髓组织iNOS表达明显降低,差异有统计学意义（P〈0．05）。结论：褪黑素可通过抑制iNOS蛋白表达对大鼠脊髓损伤起保护作用。     

通络醒脑泡腾片对MID模型大鼠血液流变学,iNOS,VEGF及LDH-5的影响

考察通络醒脑泡腾片对多发脑梗死性痴呆(multi-infarct dementia,MID)模型大鼠血液流变学,i NOS,VEGF及LDH-5影响。采用微血栓栓塞法制备MID大鼠模型,将造模成功大鼠50只随机分为模型对照组,甲磺酸双氢麦角毒碱片(喜得镇)组(0.7 mg·kg~(-1)),通络醒脑泡腾片高、中、低剂量组(7.56,3.78,1.59 g·kg~(-1)),另取10只假手术动物作为平行对照组,连续灌胃90 d。运用Morris水迷宫检测大鼠的学习记忆能力;腹主动脉取血测定不同切变率下的全血黏度和红细胞聚集指数;采用ELISA法测定血清i NOS和VEGF的含量;采用免疫组化和图像分析技术测定MID大鼠海马LDH-5的表达。结果显示通络醒脑泡腾片能明显缩短MID模型大鼠的逃避潜伏期,增加逃逸平台进入次数,延长中环滞留时间,在1,5,30,200 S-14个切变率下,也能显著降低模型大鼠的全血黏度,红细胞聚集指数以及血清i NOS,VEGF含量和LDH-5平均光密度,与模型对照组比较有统计学意义(P0.05)。结果表明通络醒脑泡腾片能提高MID模型大鼠学习记忆能力,改善外周血液流变学,降低i NOS,VEGF的含量及海马LDH-5表达,进而改善脑组织能量供应。     

IL-10 administration attenuates pulmonary neutrophil infiltration and alters pulmonary iNOS activation following hemorrhagic shock

Objective and design:  Several studies report immuno-modulatory effects of endogenous IL-10 after trauma. This study investigates the effect of IL-10 administration on systemic and pulmonary inflammation in hemorrhagic shock. Material and Methods:  Male C57/BL6 mice (4–6 animals per group) were subjected to volume controlled hemorrhagic shock for 3 hrs followed by resuscitation. Animals were either subcutaneously injected with 0.9 % saline (Shock group) or with recombinant mouse IL-10 (Shock+IL-10 group) 1 h before and 1 h after the induction of hemorrhagic shock. Serum TNF-α, IL-6, and keratinocyte (KC) concentrations were measured with the Luminex^TM multiplexing platform. Acute pulmonary inflammation was assessed by pulmonary myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activity. Results:  IL-10 administration significantly decreased serum TNF-α (10.30 ± 1.68 vs 37.42 ± 10.64; p < 0.05), IL-6 (44.22 ± 6.65 vs 85.24 ± 7.94; p < 0.05), and KC (276.74 ± 52.67 vs 465.61 ± 58.98; p < 0.05) levels following hemorrhagic shock. Further, pulmonary MPO activity was significantly lower (2698.85 ± 431.10 vs 4580.67 ± 294.38; p < 0.05) and pulmonary iNOS activity upregulated. Conclusion:  These findings suggest that administration of IL-10 modulates the degree of hemorrhage-induced systemic and pulmonary inflammation and support the notion of a central role for iNOS in acute lung injury. Received 3 June 2008; returned for revision 28 July 2008; received from final revision 7 August 2008; accepted by A. Bauhofer 4 September 2008     

Inducible nitric oxide synthase is expressed in synovial fluid granulocytes

The objective of the study was to evaluate the NO-producing potential of synovial fluid (SF) cells. SF from 15 patients with arthritis was compared with blood from the same individuals and with blood from 10 healthy controls. Cellular expression of inducible nitric oxide synthase (iNOS) was analysed by flow cytometry. High-performance liquid chromatography was used to measure l-arginine and l-citrulline. Nitrite and nitrate were measured colourimetrically utilizing the Griess' reaction. Compared to whole blood granulocytes in patients with chronic arthritis, a prominent iNOS expression was observed in SF granulocytes (P < 0.001). A slight, but statistically significant, increase in iNOS expression was also recorded in lymphocytes and monocytes from SF. l-arginine was elevated in SF compared to serum (257 +/- 78 versus 176 +/- 65 micro mol/l, P = 0.008), whereas a slight increase in l-citrulline (33 +/- 11 versus 26 +/- 9 micro mol/l), did not reach statistical significance. Great variations but no significant differences were observed comparing serum and SF levels of nitrite and nitrate, respectively, although the sum of nitrite and nitrate tended to be elevated in SF (19.2 +/- 20.7 versus 8.6 +/- 6.5 micro mol/l, P = 0.054). Synovial fluid leucocytes, in particular granulocytes, express iNOS and may thus contribute to intra-articular NO production in arthritis.     

Long-term effect of heme oxygenase (HO)-1 induction in glomerular immune injury

In a rat model of macrophage-dependent glomerular immune injury induced by administration of antibody against the glomerular basement membrane (anti-GBM), the authors assessed the anti-proteinuric effect of Heme Oxygenase-1 (HO-1) induction. Rats received anti-GBM antibody alone, anti-GBM antibody and treatment with the HO-1 inducer, hemin, or non-immune serum (controls). Urine protein, creatinine, and nitrite/nitrate excretion were measured on days 5, 7, and 14 after administration of the anti-GBM antibody. In hemin-treated animals with anti-GBM antibody-induced immune injury, HO-1 immunolocalized in macrophages infiltrating glomeruli and in tubular epithelial cells. In these animals, proteinuria was decreased. There was also a decrease in blood urea nitrogen (BUN) levels without a change in serum creatinine or systemic blood pressure. The observations establish the anti-proteinuric effect of hemin induction. This effect could be mechanistically linked to blunting of the ability of infiltrating macrophages to cause injury or to changes in tubular handling of filtered protein.