Imperatorin a furocoumarin inhibits periplasmic Cu-Zn SOD of Shigella dysenteriae their by modulates its resistance towards phagocytosis during host pathogen interaction

Shigella dysenteriae continues to be a major health problem, which leads to death, due to diarrhoea and dysentery, predominantly in children below the age of 5. Bacterial invasion of the colonic epithelium leads to severe inflammation together with bacterial dissemination generates abscesses and ulcerations. Periplasmic copper, zinc super oxide dismutase of Shigella protects it from exogenous superoxide produced by host, during its invasion. Hence, in present study an attempt was made to study the effect of aqueous extract of Aegle marmelos on host and pathogen defence. Histology analysis of rat ileal loop showed the loss of virulence in aqueous extract of A. marmelos pre-treated Shigella and their intracellular survival was also decreased, where active component present in aqueous extract of A. marmelos was identified as imperatorin confirmed by UV absorption spectrum and HPLC. Increase in peripheral blood mononuclear cell viability and decreased in intracellular bacterial count along with transmission electron microscope analysis of imperatorin treated S. dysenteriae succumb to host oxidative stress. Loss of virulence is associated with attenuation of copper, zinc super oxide dismutase activity in Shigella, which was confirmed by using activity staining of bacterial cell lysate. Further, by performing docking analysis it has been proved that imperatorin present in aqueous extract of A. marmelos inhibited copper, zinc super oxide dismutase. From the above study, we concluded that Shigella succumb to oxidative stress (host defence) due to inhibition of copper, zinc super oxide dismutase (pathogen's defence) by imperatorin, an active compound aqueous extract of A. marmelos.     

川芎嗪对大鼠脑缺血再灌注损伤的作用

目的探讨中药川芎嗪对大鼠脑缺血再灌注损伤的作用机制。方法选用雄性Wistar大鼠25只,随机分为正常对照组(n=5)、脑缺血再灌注组(n=6)、尼莫地平组(n=7)及川芎嗪组(n=7)。正常对照组不做任何处理;余3组采用改良Zea Longa线栓法建立可再通脑缺血模型,模型成功建立后,各组大鼠腹腔分别注射0.9%氯化钠注射液、尼莫地平、川芎嗪;于脑缺血3 h和再灌注后48 h分别行神经功能评分。再灌注后48 h后测定各组大鼠脑血流。处死后对脑缺血再灌注组、尼莫地平组及川芎嗪组大鼠进行TTC染色计算脑梗死体积,并测定缺血区线粒体超氧化物歧化酶(SOD)活性。结果缺血再灌注48 h后4组脑血流值两两比较差异均有统计学意义(P<0.01);尼莫地平组与川芎嗪组脑梗死神经功能恢复评分均低于给药前和缺血再灌注组,差异均有统计学意义(P<0.01),且川芎嗪组改善情况优于尼莫地平组(P<0.01);缺血再灌注各组大鼠脑梗死区相对体积组间两两比较差异均有统计学意义(P<0.05,P<0.01)。川芎嗪组大鼠脑组织线粒体SOD活性与其他缺血再灌注组比较差异均有统计学意义(P<0.01)。结论川芎嗪具有抗氧自由基作用,可修复脑缺血再灌注损伤。     

E6-AP association promotes SOD1 aggresomes degradation and suppresses toxicity

Protein aggregation and ordered fibrillar amyloid deposition inside and outside of the central nervous system cells is the common pathologic hallmark of most aging-related neurodegenerative disorders. Dominant mutations in the gene encoding superoxide dismutase 1 (SOD1) protein are linked to familial amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by progressive degeneration of motor neurons, leading to muscle paralysis and death. The major histochemical hallmark in the remaining motor neurons of ALS is the intracellular accumulation of ubiquitinated inclusions consisting of insoluble aberrant protein aggregates. However, the molecular pathomechanisms underlying the process have been elusive. Here for the first time, we report that E6-AP, a homologous to E6-AP C terminus-type E3 ubiquitin ligase depleted in ALS mouse models before neurodegeneration. E6-AP coimmunoprecipitates with the SOD1 protein and is predominantly mislocalized in mutant SOD1-containing inclusion bodies. Overexpression of E6-AP increases the ubiquitination and facilitates degradation of SOD1 proteins. Finally, we show that the overexpression of E6-AP suppresses the aggregation and cell death mediated by mutated SOD1 proteins and cellular protective effect is more prominent when E6-AP is overexpressed along with Hsp70. These data suggest that enhancing the activity of E6-AP ubiquitin ligase might be a viable therapeutic strategy to eliminate mutant SOD1-mediated toxicity in ALS.     

Amyotrophic lateral sclerosis: a new missense mutation in the SOD1 gene

Copper-zinc superoxide dismutase-1 (SOD1) is the second most common mutated gene in amyotrophic lateral sclerosis (ALS). To date more than 150 missense mutations of SOD1 have been reported. The objective of this study was to describe a novel SOD1 mutation and its phenotypic expression. We describe a 74-year-old Caucasian man who began to complain of progressive weakness and atrophy of the right hand and over 10 months developed a severe tetraparesis, with atrophies of upper and lower limbs and neck muscles, dysphagia, and dyspnea that led to percutaneous endoscopic gastrostomy and tracheotomy. A diagnosis of ALS was made. Genetic analysis identified a heterozygous mutation in exon 4 of SOD1 that results in the amino acid substitution from arginine to cysteine at position 115 (p.R115C). We identified a novel pathogenic SOD1 mutation in a patient with a very rapid disease progression and aggressive phenotype providing additional information on the wide range of SOD1 mutations in apparently sporadic ALS and confirming the possibility of a strong genotype-phenotype correlation for distinct SOD1 mutations.     

缺血预处理对大鼠压疮缺血再灌注损伤保护作用的实验研究

目的比较不同缺血处理方法对大鼠皮肤及皮下组织的保护作用,为临床判断压疮损伤的程度及压疮干预效果提供理论依据。方法将60只SD大鼠随机分为对照组（S组）、缺血再灌注组（RI组）和缺血预处理组（IPC组）,每组20只．建立大鼠压疮缺血再灌注损伤处理模型,通过肉眼观察受压程度,检测血清氧自由基的水平,以判断压疮缺血再灌注损伤程度。结果RI组和IPC组大鼠出现I期压疮的发生率为100％。IPC组血清一氧化氮、丙二醛含量高于S组,明显低于RI组．超氧化物歧化酶活性低于S组,明显高于RI组。结论缺血预处理对压疮缺血再灌注损伤具有保护作用。     

超氧化物歧化酶及游离脂肪酸检测在胰岛素抵抗疾病中的应用

目的 探讨超氧化物歧化酶(SOD)及游离脂肪酸(FFA)检测在胰岛素抵抗疾病中的应用价值.方法 选择300例2型糖尿病(DM2)患者,其中150例合并非酒精性脂肪肝(NAFLD),空腹采血检测超氧化物歧化酶(SOD)、游离脂肪酸(FFA)、胰岛素(INS)、葡萄糖(FPG)、脂类等实验室指标,同时做肝脏瞬时弹性检查(FibroScan)和受控衰减参数(CAP);选择150例体检健康者为对照组,做相同检测.结果 糖尿病组和合并NAFLD组检测结果进行对比,各项指标的差异均具有统计学意义(P＜0.05),糖尿病组、合并NAFLD组与对照组的检测结果进行对比,各项指标的差异均具有统计学意义(P＜0.05).结论 超氧化物歧化酶及游离脂肪酸检测在胰岛素抵抗疾病中有重要的应用价值.     

鼠神经生长因子对急性脑出血患者肿瘤坏死因子-α、血清基质金属蛋白酶-9和超氧化物歧化酶水平的影响

目的探讨鼠神经生长因子(NGF)对急性脑出血患者肿瘤坏死因子-α(TNF-α)、血清基质金属蛋白酶-9(MMP-9)和超氧化物歧化酶(SOD)水平的影响。方法选择急性脑出血患者64例,随机分为研究组和对照组。两组患者均予以控制血压、血糖和颅内压,营养脑细胞、止血、给氧及维持酸碱平衡等治疗。研究组在此基础上加用NGF 20μg肌肉注射,1次/d,连用2周。观察并比较两组患者治疗前后TNF-α、MMP-9和SOD水平的变化,并观察两组的临床疗效和不良反应。结果治疗2周后,两组患者血清TNF-α、MMP-9水平均较治疗前明显下降,血清SOD活性较治疗前明显上升,且研究组下降或上升幅度明显大于对照组(P<0.05);同时两组患者神经功能缺损评分均有明显下降(P<0.05或P<0.01),且研究组下降幅度较对照组更明显(P<0.05),研究组临床总有效率明显高于对照组(χ2=6.56,P<0.05)。两组患者治疗期间均未出现明显药物不良反应。结论 NGF治疗急性脑出血安全有效,作用机制与降低血浆炎症因子水平、减轻血脑屏障破环和改善氧自由基代谢密切相关。     

非酒精性脂肪性肝病兔血浆丙二醛、超氧化物歧化酶与硫化氢、一氧化氮的关系

目的观察非酒精性脂肪性肝病(NAFLD)兔血浆超氧化物歧化酶(SOD)、丙二醛(MDA)、硫化氢(H2S)、一氧化氮(NO)关系。方法 40只日本大耳白兔随机分为重、轻度NAFLD组及对照组。重度组给予高脂饲料160 g/d,轻度组给予高脂饲料80 g/d+普通饲料80 g/d,对照组给予普通饲料160 g/d。饲养周期13 w,建立不同程度NAFLD模型。实验结束采集血浆标本,按设备、试剂操作常规检测SOD、MDA、H2S、NO。结果重、轻度组MDA较对照组明显增高(P<0.01,P<0.05),且重度组明显高于轻度组(P<0.05)。重、轻度组SOD活力较对照组明显减低,重度组明显低于轻度组(均P<0.01)。重度组、轻度组H2S水平较对照组明显降低(P<0.01),重、轻度组无显著差异(P>0.05)。重、轻度组NO较对照组明显升高(P<0.01)。重度组高于轻度组(P<0.01)。结论 NAFLD兔血浆MDA/SOD、H2S/NO平衡紊乱可能是NAFLD的发病机制。