线粒体自噬受体蛋白BNIP3的研究进展

<正>作为细胞的“能量工厂”，线粒体源源不断地生产三磷酸腺苷(adenosine triphosphate, ATP)，参与细胞内多个生物合成过程，为机体细胞提供着支持生命活动过程所必需的能量，在调控细胞生长、代谢和死亡等方面发挥重要作用^[1]。然而，受损的线粒体能够生成大量的活性氧(reactiveoxygenspecies, ROS)，导致细胞功能出现紊乱甚至发生细胞死亡^[2]。     

NIX介导的线粒体自噬研究进展

<正>自噬是指细胞在缺氧、饥饿等不利条件下,利用溶酶体降解细胞器和大分子蛋白等物质,以利于细胞存活的过程。根据对降解底物的选择性,自噬可分为选择性自噬和非选择性自噬。线粒体自噬（mi-tophagy）是一种典型的选择性自噬,最早于2005年提出[1]。线粒体自噬是指细胞在受到高水平活性氧自由基（reactive oxygen species,ROS）等危害下,     

针刺对运动性骨骼肌损伤大鼠骨骼肌线粒体自噬的影响

目的:通过观察针刺对大负荷运动大鼠骨骼肌线粒体自噬相关蛋白表达的影响,探讨针刺在运动性骨骼肌损伤修复中的作用及其机制。方法:将128只成年雄性Sprague-Dawley大鼠随机分为4组:空白对照(control,C;n=8)组、单纯运动(exercise,E;n=40)组、单纯针刺(acupuncture,A;n=40)组和运动针刺(exercise and acupuncture,EA;n=40)组。其中,E和EA组进行1次下坡跑运动,A组和EA组(运动后即刻)施加针刺处理。后3组根据干预后不同时相又分为0 h、12 h、24 h、48 h和72 h亚组(n=8),分别于对应时点分离比目鱼肌进行检测,使用透射电子显微镜观察骨骼肌线粒体超微结构变化;采用ELISA法检测比目鱼肌线粒体定量酶柠檬酸合成酶(CS)的含量变化;应用Western blot法检测骨骼肌PTEN诱导假定激酶1(PINK1)、parkin和微管相关蛋白1轻链3(LC3)的蛋白表达变化。结果:1次大负荷运动后大鼠比目鱼肌线粒体出现明显肿胀和肌膜下积聚等超微结构异常变化,伴有大量自噬体形成;同时CS的含量明显减少(P0.05);线粒体自噬蛋白PINK1、parkin和LC3均出现一过性的表达升高(P0.05)。运动后针刺明显改善了线粒体超微结构的异常变化,减少自噬溶酶体的出现,同时抑制CS的含量减少,下调PINK1、parkin和LC3在线粒体上的表达(P0.05)。结论:1次大负荷运动后骨骼肌线粒体结构和数量受损,通过激活PINK1/parkin途径诱发线粒体自噬的过度发生。大负荷运动后针刺可以缓解骨骼肌线粒体的损伤,其作用机制可能是通过下调线粒体外膜蛋白PINK1表达,抑制其对下游胞浆蛋白parkin的招募,进而影响LC3与线粒体的结合以抑制线粒体自噬过度激活。     

低氧复合运动对大鼠骨骼肌线粒体含量的影响

 目的：探讨低氧复合运动对线粒体含量的影响及线粒体生物合成和自噬在其中的作用。方法：雄性SD大鼠随机分为常氧对照（NC）组、常氧运动（NT）组、低氧对照（HC）组和低氧复合运动（HT）组。低氧干预为常压低氧帐篷,11.3%氧浓度持续暴露4周。运动干预为跑台训练（5°,15 m/min）,60 min/d,每周5 d,共4周。JC-1荧光探针检测线粒体膜电位;萤光素酶法检测线粒体ATP合成能力;Western blotting检测骨骼肌过氧化物酶体增殖物激活受体γ辅激活因子1（PGC-1α）、线粒体转录因子A（Tfam）、Bcl-2/腺病毒E1B 19kD相互作用蛋白3（Bnip3）、苄氯素1（beclin-1）、细胞色素C氧化酶亚基IV（COXIV）和电压依赖性阴离子通道1（VDAC-1）蛋白表达量。结果：HC组与NC组比较,线粒体膜电位、ATP合成能力及COXIV、VDAC-1、PGC-1α和Tfam蛋白表达显著降低（P<005或P<001）,Bnip3和beclin-1蛋白表达显著升高（P<005）。HT组与HC组比较,线粒体膜电位、ATP合成能力及COXIV、VDAC-1、PGC-1α、Tfam、Bnip3和beclin-1蛋白表达均显著升高（P<005或P<001）。结论：慢性低氧暴露提高了线粒体自噬但抑制了线粒体生物合成,导致线粒体含量减少。低氧复合运动促进低氧状态下骨骼肌线粒体自噬,并促进线粒体生物合成,从而提高线粒体含量及功能。     

线粒体自噬与心力衰竭

心力衰竭(简称心衰)是指由于心脏功能障碍导致心室充盈或射血能力受损的一种复杂的综合征。目前,我国35岁以上人群慢性心衰的患病率约为0.9%[1]。随着人口老龄化,冠心病、高血压、糖尿病等慢性病的发病率增加,以及对急性心血管疾病治疗手段的提高,心衰的患病率必然进一步增加。     

线粒体自噬对结直肠癌的影响

线粒体是细胞新陈代谢和生长发育过程中重要的细胞器,能够为细胞的生命活动提供能量和底物.当细胞处于恶劣环境时,线粒体通过自噬清除不需要或损伤的线粒体来减轻负荷,补充营养物质,适应恶劣的环境.线粒体自噬对维持细胞生存,抵御环境压力,衰老和凋亡过程起着重要作用.线粒体自噬的异常将导致多种疾病,如:神经退行性变、心脏病、糖尿病以及肿瘤等.随着人们生活习惯的改变,结直肠癌的发病率和死亡率逐年增加,成为中国最常见的恶性肿瘤之一,结直肠癌与线粒体自噬的研究也成为该领域的研究热点.明确线粒体自噬对结直肠癌的作用,有助于进一步了解结直肠癌的发病机制,并为结直肠癌的诊断和治疗提供新的方向和思路.因此,本文将着重阐述线粒体自噬的发生机制及其与结直肠癌的关系.     

线粒体自噬与肺部疾病的研究进展

线粒体自噬是选择性自噬的重要形式之一,可通过调控生物体内线粒体质量影响肺部疾病发生发展。线粒体自噬在不同的肺部疾病中发挥着不同的作用。如在特发性肺纤维化与急性肺损伤中,线粒体自噬水平过高或过低都可加重病情;而在肺动脉高压中,线粒体自噬水平过高时会产生损害效应。除此之外,在慢性阻塞性肺疾病中,线粒体自噬可调节细胞坏死以及控制细胞炎性反应。因此,深入了解线粒体自噬调控机制对肺部疾病的防治具有重要意义。     

大强度耐力运动抑制骨骼肌线粒体的生物合成

背景：耐力运动对骨骼肌线粒体生成影响的研究多采用中小强度,长期大强度对其有何影响还不清楚,这种影响是否涉及5’-一磷酸腺苷激活的蛋白激酶(AMPK)、沉默信息调节因子2相关酶1(SIRT1)等调节线粒体生成的信号分子也未见报道。 目的：观察AMPK/SIRT1信号级联在7周不同强度耐力运动中对骨骼肌线粒体生物合成的影响。 方法：42只雄性SD大鼠分为安静组、中等强度运动组和大强度运动组。运动负荷为中等强度组28 m/min,60 min/d、大强度组38 m/min,60 min/d,每周运动5 d,休息2 d,共7周。运动组动物分别在运动后即刻、6 h和24 h取材。荧光定量PCR检测骨骼肌PGC-1α 、SIRT1基因表达,Western blot测定P-AMPK、SIRT1蛋白表达。 结果与结论：①中等强度运动后即刻、6 h、24 h,骨骼肌PGC-1α mRNA表达分别为安静组的362%(P < 0.01)、657%(P < 0.01)、116%,P-AMPK蛋白表达分别为安静组的112%、163%(P < 0.05)、129%(P < 0.05),SIRT1蛋白和mRNA表达分别为安静组的55%(P < 0.05)、86%、103%和109%、155%(P < 0.05)、132%(P < 0.05)。②大强度运动后即刻、6 h、24 h,骨骼肌PGC-1α mRNA表达分别为安静组的274%(P < 0.01)、130%(P < 0.05)、68%(P < 0.05),P-AMPK蛋白表达分别为安静组的235%(P < 0.01)、166%(P < 0.05)、160%(P < 0.05),SIRT1蛋白和mRNA表达分别为安静组的199%(P < 0.01)、166%(P < 0.05)、164%(P < 0.05)和255%(P < 0.01)、292%(P < 0.01)、122%。结果表明：①7周中等强度耐力运动显著增加骨骼肌PGC-1α基因表达,其机制可能涉及AMPK/SIRT1信号级联。②7周大强度耐力运动造成骨骼肌PGC-1α基因表达在运动后24 h时被抑制,这一过程是以非AMPK/SIRT1信号级联依赖性方式进行的。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

线粒体自噬与心血管疾病

线粒体自噬是一种细胞内针对功能异常线粒体的选择性降解机制,在细胞的线粒体质量控制中发挥重要作用.近年来,越来越多的研究发现线粒体自噬参与心血管疾病的发生、发展,如高血压、动脉粥样硬化、心肌缺血/再灌注损伤和心力衰竭等.因此,本文就线粒体自噬的定义、线粒体自噬的两大类活化启动机制(包括泛素依赖型和受体依赖型两大途径及其分...     

线粒体自噬最新研究进展

活性氧由线粒体产生且作用于线粒体.在压力环境下,选择性降解损伤的线粒体,并维持正常的线粒体数量对维持细胞的正常结构、生长起重要作用.线粒体通透性改变、过氧化氢酶失活等诸多影响因素都会促进线粒体自噬的发生.最近研究发现PINK1-Parkin信号通路,Mfn1、Mfn2和OPA1等蛋白与线粒体关系紧密,调控线粒体的融合、分裂、自噬.线粒体自噬可能导致神经退行性疾病,主要的神经退行性疾病包括帕金森病(Parkinson's disease,PD)、肌萎缩侧索硬化症(Alzheimer's disease,AD)、亨廷顿舞蹈病等(Huntington's disease,HD),这些与线粒体的动态改变有关.     

Effects of training at mild exercise intensities on quadriceps muscle energy metabolism in patients with chronic obstructive pulmonary disease

Aim: To study the effects of physical training at mild intensities on skeletal muscle energy metabolism in eight patients with chronic obstructive pulmonary disease (COPD) and eight paired healthy sedentary subjects. Methods: Energy metabolism of patients and controls vastus lateralis muscle was studied before and after 3 months of cycling training at mild exercises intensities. Results: The total amount of work accomplished was about 4059 ± 336 kJ in patients with COPD and 7531 ± 1693 kJ in control subjects. This work corresponds to a mechanical power set at 65.2 ± 7.5% of the maximum power for patients with COPD and 52 ± 3.3% of the maximum power in control group. Despite this low level of exercise intensities, we observed an improvement in mitochondrial oxidative phosphorylation through the creatine kinase system revealed by the increased apparent K_m for ADP (from 105.5 ± 16.1 to 176.9 ± 26.5 μm , P < 0.05 in the COPD group and from 126.9 ± 16.8 to 177.7 ± 17.0, P > 0.05 in the control group). Meanwhile, maximal mechanical and metabolic power increased significantly from 83.1 ± 7.1 to 91.3 ± 7.4 Watts (P < 0.05) and from 16 ± 0.8 to 18.7 ± 0.98 mL O₂ kg^?1 min^?1 (P < 0.05) only in the COPD group. Conclusion: This study shows that physical training at mild intensity is able to induce comparable changes in skeletal muscles oxidative energy metabolism in patients with COPD and sedentary healthy subjects, but different changes of maximal mechanical and metabolic power.     

BNIP3 expression in follicular lymphoma

AIMS: To investigate the role of BNIP3, a 19-kDa interacting protein of the Bcl-2 family, alongside Bcl-2 in follicular lymphoma in comparison with reactive lymphoid hyperplasia. The results were compared with those from p53 and caspase-3 (apoptotic markers) and Ki67 (proliferation marker). METHODS AND RESULTS: Immunohistochemistry using monoclonal antibodies showed BNIP3 to be strongly expressed in most follicular lymphomas but to be weak to negative in all of the reactive cases. There was also an inverse relationship with Bcl-2 expression. There was no correlation of BNIP3 immunoreactivity with proliferation and caspase and p53 were virtually negative in all follicular lymphomas and reactive lymphoid cases. CONCLUSIONS: BNIP3 is strongly expressed in most follicular lymphomas, especially those that are Bcl-2 negative. BNIP3 may serve as a marker of more aggressive behaviour in follicular lymphoma and be useful diagnostically in the distinction from reactive lymphadenitis.     

兔退变椎间盘中BNIP3的免疫组织化学研究

目的探讨兔退变椎间盘中BNIP3蛋白的表达情况。方法建立兔椎间盘穿刺退变模型,分别培养2、4、8周后对目的椎间盘进行组织HE染色、番红O染色及BNIP3免疫组织化学染色,与正常椎间盘随机对照,检测椎间盘退变程度及BNIP3蛋白表达情况。结果成功建立兔椎间盘退变模型,随椎间盘退变程度加重,BNIP3蛋白在中央髓核组织中的阳性表达逐渐增强。结论兔椎间盘退变过程中,BNIP3蛋白表达增强诱导髓核细胞死亡增加。     

Effects of streptozotocin-induced diabetes,physical training and their combination on collagen biosynthesis in rat skeletal muscle

The effects of streptozotocin-induced diabetes, physical training and their combination on the activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyl-transferase (GGT), both marker enzymes of collagen biosynthesis, and on the concentration of hydroxyproline (Hyp) were studied in vastus lateralis, rectus femoris and gastrocnemius muscles in rats. The experimental period was 12–16 weeks. Diabetes had an overall decreasing effect on specific PH activity in all muscles studied, whereas specific GGT activity remained at control level. Total PH and GGT activities decreased in all three muscles in the diabetic animals (P < 0,001). Training caused an increase in PH and GGT activities in gastrocnemius in non-diabetic rats, whereas training in combination with diabetes did not change specific PH or GGT activity. Diabetes increased specific Hyp concentration in vastus lateralis and gastrocnemius in trained diabetic rats (P < 0.05), whereas training decreased Hyp level significantly (P < 0.05) in vastus lateralis in non-diabetic rats, but not in diabetic animals. The results suggest that in streptozotocin-induced diabetes the decrease in collagen synthesis rate exceeds the negative total protein balance in the muscle. Although physical training may have an increasing effect on muscular collagen synthesis in non-diabetic rats, it is unable to prevent the decreasing effect of diabetes on collagen synthesis.     

Uptake of 3H-leucine into different fractions of rat skeletal muscle following acute endurance and sprint exercise

Summary In order to study the specificity of the protein synthetic response to different acute exercise loads, 48 male rats served as non-exercised controls or ran at either 0.5 m·s^–1 for 1 h or 1.5 m·s^–1, 10 s20 s workrest, for 1h. Animals were killed and red and white vastus muscles excised from the controls or at 0, 2, 18, 24, or 48 h post-exercise. Muscle slices were incubated in a medium containing 10 Ci l-[4,5-³H]leucine for 30 min. Incorporation of the radionuclide was measured by liquid scintillation (dpm·mg^–1 protein) in the whole homogenate and in four subcellular fractions. The endurance exercise elicited increased uptakes into the mitochondrial fractions of both red and white vastus at 2 and 18 h respectively. However, the mitochondrial uptake was depressed at 24 h in the red and at 2 h in the white vastus. Only in red vastus was incorporation into the soluble protein elevated following endurance exercise. The sprint protocol elicited increased uptake into soluble protein at 2 and 18 h in both red and white vastus and into mitochondrial protein at 18 and 24 h in the white vastus. The shifts in uptake in white vastus occurred in conjunction with depressed uptakes in the total homogenate. These data indicate that both the changes in the type of protein and the time course of amino acid incorporation following acute exercise are related to both the metabolic characteristics of the muscle fibres and the intensity of the exercise.This study was supported by Grants from the Natural Sciences and Engineering Research Council (NSERC A0424 and NSERC A6436)