年龄因素对大鼠睾丸中脑红蛋白表达的影响

目的:探讨脑红蛋白(neuroglobin,NGB)在不同年龄段大鼠睾丸中的分布特征及表达差异。方法:随机选取3月、9月、15月龄SD雄性大鼠,每个年龄段各8只,处死后立即在无菌情况下取睾丸组织,免疫组织化学SP法观测NGB在大鼠睾丸中的定位,巢式PCR和Western blotting分析NGB mRNA和蛋白的表达差异。结果:免疫组织化学显示NGB在大鼠睾丸的间质细胞、精原细胞、各级精母细胞、支持细胞和精子细胞的胞质和胞核都有表达;巢式PCR检测表明9月龄组大鼠睾丸组织中NGB mRNA表达量最高,15月龄组表达次之,3月龄组表达量最低;而NGB蛋白表达与其mRNA相一致。结论:NGB在各年龄段大鼠睾丸组织中广泛表达,且年龄因素影响大鼠睾丸中脑红蛋白的表达。     

Evaluation of globins expression in brain,heart, and lung in rats exposed to side stream cigarette smoke

The side stream cigarette smoke (SSCS) is a contributing factor in the pathogenesis of cigarette smoking‐induced toxicity. Hemoglobin (Hb), myoglobin (Mb), neuroglobin (Ngb), and cytoglobin (Cygb) are globins with different distributions and functions in the tissues and have similar actions by providing O₂ (oxygen) for respiratory chain, detoxification of ROS and nitric oxide (NO), and protect tissues against irreversible lesions. We aimed to investigate the effects of SSCS exposure on gene and protein expression of Ngb, Cygb, and Mb in different tissue. The Ngb and Cygb gene and protein expression in the cerebral cortex increased after 1 week of rat exposure to SSCS. In hippocampus, the Ngb gene and protein expression increased after 1 week or more of exposure and no change was observed in Cygb gene and protein expression. In myocardium, Mb and Cygb gene expression increased at 1 and 4 weeks of exposure, while protein expression of both increased at 1, 2, 3, and 4 weeks. In lung, observed an increase in Cygb gene and protein expression after 2, 3, and 4 weeks of exposure. The findings suggest that SSCS modulates Ngb, Cygb, and Mb in central and peripheral tissue © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1252–1261, 2017.     

大鼠弥漫性颅脑损伤后脑红蛋白mRNA变化的实验研究

目的研究弥漫性颅脑损伤后大鼠脑组织中脑红蛋白（NGB）mRNA的表达变化情况，初步探讨NGB与颅脑损伤的关系。方法选择Marmarou自由落体打击装置制作弥漫性颅脑损伤模型．采用实时、定量PCR检测伤后不同时间脑组织中NGB mRNA的表达情况，并对所得数据进行统计学分析。结果在伤后30min，脑组织中NGB mRNA的表达出现首个高峰．此后逐渐下降，至6h恢复至正常水平；伤后12h再次升高，于伤后48h达高峰，此后下降，至伤后5d仍高于正常水平。结论弥漫性颅脑损伤后，脑组织中NGB mRNA表达呈“双峰”，提示其可能参与神经元损伤后应激及继发缺血、缺氧性脑损害的应答机制。     

脑红蛋白在脑缺血大鼠中的动态表达及脑保护作用

目的:研究脑红蛋白(neuroglobin,Ngb)在大鼠脑缺血模型中的动态表达及缺血缺氧后Ngb的脑保护作用.方法:将SD大鼠随机分为4组.即大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)组、出血性脑梗死(HI)组、氯化血红素(Hemin)干预组和假手术组,以建模后3、6、12、24 h为观察点,测定脑组织含水量、脑梗死体积,H-E染色观察组织病理学改变,免疫组化染色观察Ngb的表达.结果:Hemin处理组脑组织含水量、脑梗死体积较MCAO组和HI组有显著性差异(P<0.01);HI组脑水肿在12 h显著升高;病理切片观察,Hemin处理组水肿程度及变性神经元数量较MCAO组和HI组减轻;免疫组化分析,Hemin处理组Ngb阳性神经元数量较MCAO组和HI组增多.结论:HI组脑水肿高峰提前可能导致原有病情的加重,应用Heroin诱导Ngb的表达,可减轻局灶性脑缺血时脑组织的损伤,从而达到脑保护作用.     

脑红蛋白在脑梗死大鼠脑组织中的表达及其神经保护作用机制

目的：观察脑梗死大鼠脑组织中脑红蛋白（Ngb）的表达及其对PI3K/Akt 信号通路的影响,探讨二者在缺血性脑损伤中的作用及Ngb神经保护作用的可能机制。方法：60只SD大鼠随机分为假手术组、缺血组、Hemin（Ngb 诱导剂）组、LY（PI3-K/Akt抑制剂LY294002）组和Hemin＋LY组,每组12只。应用大脑中动脉线栓法制备脑梗死动物模型,术后24 h观察各组大鼠神经功能评分和脑组织梗死体积;应用RT-PCR法检测各组大鼠脑组织Ngb mRNA表达水平及PI3-K/Akt活性。结果：假手术组未见TTC不着色区,未检出神经功能缺损。与缺血组比较,Hemin组大鼠脑组织中Ngb和Akt mRNA表达水平升高（P<0.01）,神经功能评分降低（P<0.05）,脑梗死体积减小（P<0.01）;与缺血组比较,LY组大鼠脑梗死体积增加（P<0.01）,神经功能评分升高（P<0.05）,Akt mRNA表达水平降低（P<0.01）,Ngb无明显变化。与Hemin组比较,Hemin＋LY组大鼠脑组织损伤加重,Akt mRNA表达水平明显降低（P<0.01）,Ngb未被抑制。结论：Ngb可以减小局灶性脑缺血大鼠脑梗死体积,改善神经功能,并且可能通过PI3K/ Akt信号通路发挥神经保护作用。     

创伤性脑损伤后脑红蛋白的表达变化

目的 观察创伤性脑损伤后伤灶周围皮质脑红蛋白（Ngb）的表达变化.方法 采用自由落体硬膜外撞击方法建立脑外伤模型,应用免疫组织化学和Western Blot技术,定量观察创伤性脑损伤后Ngb的表达变化.结果 各实验组之间阳性信号面积没有统计学差异（P＞0.05）;但外伤后,光密度或累积光密度均明显增高（P＜0.05或P＜0.01）.结论 脑外伤后伤灶周围皮质神经元Ngb的表达增高,提示Ngb可能参与了脑外伤后伤灶周围神经元的保护过程.     

脑红蛋白在改良线栓法制备大鼠局灶性脑缺血再灌注模型的表达

目的：研究脑缺血再灌注损伤后脑红蛋白（NGB）在大脑皮质和海马区的表达变化。方法：改良ZeaLonga线栓法制备W istar大鼠大脑中动脉闭塞/再灌注模型（MCAO/R）,在缺血2h后随机分为1h、4h、8h、16h、32h、64h和128h再灌注组和假手术组。采用神经功能评价、TTC染色、脑梗死体积测定、光镜HE检测等方法对不同组大鼠予以评价。采用免疫组化染色结合阳性细胞计数的方法,检测脑缺血再灌注损伤不同时间点大鼠脑组织梗死中心区和半暗带区NGB的表达变化。结果：大鼠脑缺血再灌注损伤后,大脑皮质的NGB蛋白表达损伤后呈现出先上升后下降的趋势,而非缺血侧对称区域皮质阳性表达不随时间变化。海马区NGB表达则呈持续减少的趋势。病理学检测显示海马区神经细胞损伤程度较大脑皮质区严重。结论：不同脑区对缺血性损伤的耐受性差异可能与NGB表达水平有关。NGB表达上调可能对脑缺血再灌注损伤具有保护作用。     

Neuroglobin mRNA expression after transient global brain ischemia and prolonged hypoxia in cell culture

Neuroglobin is a nerve-specific respiratory protein that has been proposed to play an important role in the protection of brain neurons from ischemic and hypoxic injuries. Here, we investigated the regulation of neuroglobin expression after transient global ischemia in the rat brain using mRNA in situ hybridization and under hypoxic stress in cultured neuronal cell lines (PC12, HN33) by quantitative RT-PCR. While neuroglobin mRNA expression was significantly enhanced in cell culture after severe prolonged hypoxia (0-1% O2 for 24 h), we did not find any significant increases in neuroglobin mRNA levels in the rat brain after transient global ischemia. Vegf and Glut1 mRNAs showed increases in the hippocampus as expected. Therefore, it is unlikely that neuroglobin is instrumental in the acute response of neurons to hypoxic or ischemic insults, for which the mammalian brain is not adapted.     

脑红蛋白与脑红蛋白介导的神经元保护作用

脑红蛋白是新近发现的球蛋白超家族中的一员,主要表达在脊椎动物的大脑和视网膜中.脑红蛋白在生物体中的作用至今尚不明确,但它与氧的亲和性及在中枢神经元的高度表达提示其在神经元缺血缺氧反应中是重要的神经元保护因子.脑红蛋白可以使氧气更容易弥散入线粒体;与钠钾ATP酶结合并调节其活性;清除活性氧和一氧化氮;在缺氧状态下减少细胞间信号转导;诱导一些重要的神经营养因子表达,如内皮型一氧化氮合酶.     

Neuroglobin mitigates mitochondrial impairments induced by acute inhalation of combustion smoke in the mouse brain

Abstract

Context: Acute inhalation of combustion smoke adversely affects brain homeostasis and energy metabolism. We previously showed that overexpressed neuroglobin (Ngb), neuron specific globin protein, attenuates the formation of smoke inhalation-induced oxidative DNA damage, in vivo, in the mouse brain, while others reported protection by Ngb in diverse models of brain injury, mainly involving oxidative stress and hypoxic/ischemic insults.

Objective: To determine to what extent elevated Ngb ameliorates post smoke-inhalation brain bioenergetics and homeostasis in Ngb overexpressing transgenic mouse.

Methods: Smoke inhalation induced changes in bioenergetics were measured in the wild type and Ngb transgene mouse brain. Modulations of mitochondrial respiration were analyzed using the Seahorse XF24 flux analyzer and changes in cytoplasmic energy metabolism were assessed by measuring enzymatic activities and lactate in the course of post smoke recovery.

Results: Cortical mitochondria from Ngb transgene, better maintained ATP synthesis-linked oxygen consumption and unlike wild type mitochondria did not increase futile oxygen consumption feeding the proton leak, reflecting lesser smoke-induced mitochondrial compromise. Measurements revealed lesser reduction of mitochondrial ATP content and lesser compensatory increases in cytosolic energy metabolism, involving pyruvate kinase and lactate dehydrogenase activities as well as cytosolic lactate levels. Additionally, induction of c-Fos, the early response gene and key neuronal stress sensor, was attenuated in Ngb transgene compared to wild type brain after smoke.

Conclusion: Considered together, these differences reflect lesser perturbations produced by acute inhalation of combustion smoke in the Ngb overexpressing mouse, suggesting that Ngb mitigates mitochondrial dysfunction and neurotoxicity and raises the threshold of smoke inhalation-induced brain injury.