线粒体DNA变异与肥厚型心肌病

目的肥厚型心肌病（hypertrophiccardiomyopathy,HCM）是指未伴心室扩张的不明原因左室肥厚,以室间隔非对称性肥厚常见。HCM多由编码肌小节蛋白的基因突变所致;有少部分患者由线粒体DNA突变引起,呈母系遗传。线粒体DNA变异导致HCM的分子机制可能与引起的线粒体结构功能改变,造成氧化磷酸化缺陷,ATP合成不足。本文着重对与HCM相关的mtDNA变异位点作一综述。     

心力衰竭患者心肌线粒体脱氧核糖核酸损伤与衰竭心肌线粒体酶活性的关系

目的 :为探讨心肌线粒体脱氧核糖核酸 (mt DNA)获得性损伤对衰竭心肌线粒体酶活性改变的影响 ,确立 mt DNA损伤在衰竭心肌发病中的作用。　　方法 :对 2 8例慢性心力衰竭患者活检心肌 ,用定量聚合酶链式反应 (PCR)及生化方法 ,观察衰竭心肌中常发缺失型突变 mt DNA4977和 mt DNA7436 缺失率与线粒体呼吸酶活性和心脏功能受损之间的关系。　　结果 :慢性心力衰竭患者活检心肌中的 mt DNA存在不同程度的缺失突变损伤 ,两种缺失类型合计的缺失率在0 .10 2 %～ 1.745 %之间 ;mt DNA缺失率与心肌生化水平上的线粒体呼吸酶活性改变相关性良好 ;同时与整体水平上的心脏泵功能受损呈一致性关系。　　结论 :心肌 mt DNA损伤与心肌线粒体呼吸功能下降和心脏功能受损程度密切相关 ,提示 mt DNA损伤可能参与了心力衰竭的形成与发展。     

线粒体DNA13731点突变与脊髓小脑性共济失调相关性研究

目的 探索线粒体DNA(mtDNA)突变位点与脊髓小脑性共济失调(SCA)的关系.方法 采用聚合酶链反应(PCR)对基因确诊的四个SCA家系10例患者及其亲属共34例与40例健康对照的线粒体ND5基因片段进行扩增,扩增产物进行单链构象多态性分析(SSCP),对SSCP出现异常的样本进行相应mtDNA片段测序.结果 在一家系的1名确诊患者及1名症状前患者检测到mtDNA13731(T>C)点突变.结论 脊髓小脑性共济失调的发生、发展可能与mtDNA突变有关.     

线粒体DNA部分点突变与遗传性共济失调的关系研究

目的探索线粒体DNA部分点突变与遗传性共济失调(hereditary ataxia,HA)的关系。方法对广西壮族自治区第二人民医院神经内科和广西医科大学附属第一医院神经内科1985—2004年收治的临床确诊为HA的30例患者及其部分亲属与2003年7月至12月35名健康体检者外周血白细胞的4个mtDNA片断,即点3243、8993、8344和点11778所在片断采用聚合酶链反应(PCR)扩增。对点3243、8993的PCR产物采用限制性片断长度多态性(RFLP)分析法检测该片断中有无A3243G、T8993G或T8993C点突变;对点8344、11778的PCR产物进行单链构象多态性分析(SSCP),并与患者亲属及健康人进行比较。对SSCP出现异常条带的研究对象进行相应mtDNA片断测序。结果所有研究对象均未检测到A3243G、T8993G或T8993C点突变;点8344所在mtD-NA片断中均未检测到突变。但在家系1中的2例患者及1名无临床症状亲属检测到mtDNAA11893G点突变。结论HA的发生、发展可能与该区域点突变有关。     

Mitochondrial DNA sequence analysis of two mouse hepatocarcinoma cell lines

AIM: To study genetic difference of mitochondrial DNA (mtDNA) between two hepatocarcinoma cell lines (Hca-F and Hca-P) with diverse metastatic characteristics and the relationship between mtDNA changes in cancer cells and their oncogenic phenotype.METHODS: Mitochonddal DNA D-loop, tRNA^Met+Glu+Ile and ND3 gene fragments from the hepatocarcinoma cell lines with 1100, 1126 and 534bp in length respectively were analysed by PCR amplification and restriction fragment length polymorphism techniques. The D-loop 3‘ end sequence of the hepatocarcinoma cell lines was determined by sequencing. RESULTS: No amplification fragment length polymorphism and restriction fragment length polymorphism were observed in tRNA^Met+Glu+Ile, ND3 and D-loop of mitochondrial DNA of the hepatocarcinoma cells. Sequence differences between Hca-F and Hca-P were found in mtDNA D-loop.CONCLUSION: Deletion mutations of mitochondrial DNA restriction fragment may not play a significant role in carcinogenesis. Genetic difference of mtDNA D-loop between Hca-F and Hca-P, which may reflect the environmental and genetic influences during tumor progression, could be linked to their tumorigenic phenotypes.     

结直肠癌组织中线粒体DNA D-环区突变的研究

背景：近年线粒体DNA与肿瘤之间的相关性已成为新的研究热点，目前已在多种恶性肿瘤或癌前病变中检测到线粒体突变。目的：研究线粒体DNAD-环区在结直肠癌组织中的突变情况，探讨其在结直肠癌发生、发展中的作用。方法：以聚合酶链反应（PCR）扩增40例结直肠癌患者肿瘤组织和癌旁组织的线粒体DNAD-环区，扩增产物直接测序。结果：40例结直肠癌患者中，共发现50个D-环区多态性，其中2个为BLAST数据库中未记录的新多态性。14例患者存在线粒体DNAD-环区突变，突变率为35％，突变位点12个，其中9个点突变，2个微卫星不稳定，1个缺失。结论：结直肠癌组织线粒体DNAD-环区具有高度多态性和高突变率，可能与结直肠癌的发生、发展有关。     

Mitochondrial DNA alterations and mitochondrial dysfunction in the progression of hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is one of the most common malignancies and is ranked third in mortality among cancer-related diseases.Mitochondria are intracellular organelles that are responsible for energy metabolism and cellular homeostasis,and mitochondrial dysfunction has been regarded as a hallmark of cancer.Over the past decades,several types of mitochondrial DNA(mtDNA)alterations have been identified in human cancers,including HCC.However,the role of these mtDNA alterations in cancer progression is unclear.In this review,we summarize the recent findings on the somatic mtDNA alterations identified in HCC and their relationships with the clinicopathological features of HCC.Recent advances in understanding the potential roles of somatic mtDNA alterations in the progression of HCC are also discussed.We suggest that somatic mtDNA mutations and a decrease in the mtDNA copy number are common events in HCC and that a mitochondrial dysfunction-activated signaling cascade may play an important role in the progression of HCC.Elucidation of the retrograde signaling pathways in HCC and the quest for strategies to block some of these pathways will be instrumental for the development of novel treatments for this and other malignancies.     

Elevated Plasma Homocysteine in Alcoholics

A significantly higher concentration of plasma homocysteine compared with controls was noted in a group of alcoholics ( n = 42) hospitalized for detoxication. Normal concentrations of plasma homocysteine were reached within 1 or 2 weeks after admission to the hospital. In another group of abstinent alcoholics ( n = 16) plasma homocysteine did not deviate from that of controls. Since hyperhomocysteinemia has been associated with premature vascular disease, we speculate that the increased plasma homocysteine in alcoholics might cause the increased incidence of stroke found in these patients.     

Mitochondrial DNA,diabetes and pancreatic pathology in Kearns-Sayre syndrome

Summary Mitochondrial DNA (mtDNA) mutations are associated with diabetes mellitus but their role in the onset of hyperglycaemia is unclear. A patient presented with diabetes requiring insulin therapy at the age of 7 years, followed by diagnosis of Kearns–Sayre syndrome (KSS). Beta-cell function was absent at age 19 years as shown by lack of glucose-stimulated C-peptide secretion. Following development of a cardiac conduction defect the patient died aged 21 years. Analysis of mtDNA in blood and several tissues revealed related re-arranged deletions, duplications and deletion dimers in addition to normal mtDNA with the highest levels of duplications in kidney and blood. Pancreatic tissue from the KSS patient was compared with tissue from an insulin-dependent diabetic patient with a similar clinical history of diabetes. Islets in KSS were small, regular in shape and contained predominantly glucagon-containing cells with no evidence of beta cells. In comparison, a small number of beta cells were present in some of the larger more irregularly-shaped islets from the insulin-dependent diabetic patient. These data together suggest that in KSS the loss of beta cells at the onset of diabetes is less disruptive to islet architecture: a small proportion of beta cells or their gradual destruction over a long period would allow retention of islet shape. Abnormal function of the re-arranged mtDNA could affect both development and function of pancreatic islet cells since glucose-stimulated insulin secretion is energy dependent. [Diabetologia (1995) 38: 868–871]. Received: 19 January 1995 and in revised form: 17 March 1995     

Mutation of Mitochondrial DNA in Livers From Patients With Alcoholic Hepatitis and Nonalcoholic Steatohepatitis

Background: In alcoholic hepatitis (Al-Hep) and nonalcoholic steatohepatitis (NASH), triglycerides accumulate in hepatocytes. We examined the hypothesis that mutations in mitochondrial DNA may take place by mitochondrial overwork, resulting in dysfunction of mitochondria.
Subjects and Methods: Subjects of this research were 8 cases each of Al-Hep, NASH, and fatty liver (FL). Total DNA was extracted from the biopsied liver samples. DNA fragments were amplified by PCR and DNA sequences determined in the control and coding regions of mitochondrion.
Results: When the numbers of mutations per 1,000 bases of mitochondrial DNA were compared between each group, no significant differences were found among D-loop, HV1, and HV2 mitochondrial DNA regions. However, there were significantly more mutations in ND1 and COII of Al-Hep and NASH than in FL, and mutations were comparatively at random. Neither a region in which mutations were focused nor differences among the groups were recognized. When details of the base mutation in a control region were investigated by group, the transition type of mutation between T:A≪–≫C:G occurred in at least 70%. Also, a transition-type mutation was found mostly in a coding region, which was similar to the mutation pattern in the control region, except for the ND1 and COII regions where there were hardly any mutations.
Conclusions: As gene mutations of mitochondrial DNA appeared frequently in Al-Hep, and also in NASH, mitochondrial dysfunction caused by mutation in mitochondrial DNA may be involved in the pathogenesis of both diseases.     

Mitochondrial dysfunction and mitochondrial DNA mutations in atherosclerotic complications in diabetes

Mitochondrial DNA(mtDNA) is particularly prone to oxidation due to the lack of histones and a deficient mismatch repair system.This explains an increased mutation rate of mtDNA that results in heteroplasmy,e.g.,the coexistence of the mutant and wild-type mtDNA molecules within the same mitochondrion.In diabetes mellitus,glycotoxicity,advanced oxidative stress,collagen cross-linking,and accumulation of lipid peroxides in foam macrophage cells and arterial wall cells may significantly decrease the mutation threshold required for mitochondrial dysfunction,which in turn further contributes to the oxidative damage of the diabetic vascular wall,endothelial dysfunc-tion,and atherosclerosis.     

A Comparison of Older and Younger Adults Attending Alcoholics Anonymous

Abstract

This study was conducted to explore some of the differences between older and younger participants on measures of emotional support, depression, loneliness and life satisfaction. A total of 160 adults (72 males and 87 females), ranging in age from 18 to 83, who attended one of 18 different AA. meetings in Massachusetts were examined. The respondents were divided into three groups based on age (under 40, 40-65, 65+). The youngest group reported the greatest number of depressive symptoms and the lowest level of life satisfaction. The oldest group reported the lowest number of depressive symptoms and the greatest amount of life satisfaction. Most of the findings can probably be attributed to length of sobriety. While A. A. helped these elders maintain long-term sobriety, the program does not appear to be attracting older persons who are struggling to overcome dependency upon alcohol and/or drugs.     

Personality Characteristics of Sisters and Spouses of Male Alcoholics

Sisters of alcoholics from high-density multigenerational families were assessed to determine personality characteristics. Spousal similarity was evaluated in proband/spouse pairs and in spouse pairs from the parental generation, allowing for comparisons of selection versus contagion as explanations for this similarity.
Sisters were found to differ from control women with respect to Alienation and Social Closeness from the Multidimensional Personality Questionnaire, and Scale 6 (Paranoia) from the Minnesota Multiphasic Personality Inventory. Only spouses from the parental generation were similar on Alienation, suggesting that exposure over time (contagion) leads to greater similarity in parents from High-Risk families. Modest correlations in spouse pairs from both generations suggest that assortative mating for Social Closeness occurs among the parents of these individuals from High-Risk families, and further suggest that a diminished level of Social Closeness for sisters of alcoholics may be mediated in part by additive genetic variance. It is concluded that assortative mating for particular traits may contribute to increased risk for alcoholism. Also, failure to mate assortatively for other traits (e.g., Traditionalism, Harm Avoidance) may also contribute to increased rates in High-Risk families.     

充血性心力衰竭患者线粒体DNA缺失的意义

为探讨线粒体DNA（mtDNA）5．0kb缺失与充血性心力衰竭（CHF）发病的关系，应用聚合酶链反应（PCR）技术分析72例CHF患者的mtDNA。结果显示，CHF患者mtDNA5．0kb缺失率明显高于对照组（0.254％±0．08％比0．032％±0．01％，P＜0．01）；CHF组内扩张型心肌病组及冠心病组mtDNA5．0kb缺失率高于风心病及高血压心脏病组（P＜0．05）。研究中还发现，随着心功能分级增加，mtDNA5．0kb缺失率增高（P＜0．05）。提示mtDNA缺失影响心肌细胞线粒体呼吸功能，心肌能量供应障碍与CHF的发生、发展有关。     

扩张型心肌病患儿线粒体DNA缺失的研究

采用PCR法检测了15例扩张型心肌病（DCM）、13例急性心肌炎（病程＜3个月）患儿和10例正常儿童外周血淋巴细胞中线粒体DNA（mtDNA）的缺失情况,以研究mtDNA突变在DCM发病中的作用。结果显示,被检者线粒体均存在5Kb和7.4Kb的mtDNA缺失,但DCM患儿的缺失率显著高于心肌炎患儿和正常儿童（缺失率分别为7.97±3．51％,2.5±1．64％和2.28±1．76％,P＜0．05）。提示mtDNA缺失与部分DCM的发病有关。     

线粒体突变及不稳定在胃癌中的研究

目的 探讨线粒体突变及不稳定在胃癌发生、发展中的作用.方法 利用激光显微切割技术分离胃癌组织及其切缘的正常组织,应用变性高效液相色谱DHPLC对胃癌线粒体D-loop调控区D-loop-(CA)n进行突变筛查及测序分析,同时进行线粒体D-loop非编码区(CA)n重复序列的不稳定(mtMSI)检测.结果 胃癌组织样本中D-loop-(CA)n调控区基因突变率为50.8％ (31/61),正常组织均未见有序列改变.29.5％ (18/61)发生线粒体重复序列(CA)n的不稳定.18例线粒体不稳定(mtMSI)中有16.4％(10/61)同时发生D-loop点突变,有8例同时存在核不稳定(nMSI-H).结论 胃癌mtDNA异常参与了肿瘤的发生、发展.     

Cognitive Efficiency in Alcoholics and Polysubstance Abusers

Previous studies have found alcoholics to be impaired on tests of cognitive efficiency. However, it is unclear to what extent individuals who abuse drugs in addition to alcohol exhibit similar deficits. To answer this question, 63 healthy control subjects were compared with 40 individuals who abused alcohol only, 24 individuals who abused alcohol and stimulants, 16 individuals who abused alcohol and marijuana, and 41 individuals who abused alcohol and depres-sants/narcotics, or alcohol and two or more other drugs. All subjects were administered tests of Short-term memory, spatial orientation, visual-spatial perception, and problem-solving. Results from the study indicated that control subjects and individuals who abused both alcohol and marijuana performed significantly better than the other groups on most tests. These results were not attributable to differences on measures of affect or chronicity of alcohol consumption.     

Mitochondrial DNA content in paired normal and cancerous breast tissue samples from patients with breast cancer

Introduction  We develop a multiplex quantitative real-time PCR for synchronized analysis of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) to investigate relative mtDNA abundance in paired normal and cancerous breast tissues. Materials and methods  The amounts of nDNA and mtDNA in 102 tissue samples were quantified for both glyceraldehype-3-phosphodehydrogenase (GAPDH) gene and mtDNA encoded ATPase (MTATP) 8 gene. The average threshold cycle (Ct) number values of the nDNA and mtDNA were used to calculate relative mtDNA content in breast tissues. Results  The median delta Ct (ΔCt) and the median mtDNA content for normal and cancerous breast tissues were 6.73 and 2.54, as well as 106.50 and 5.80 (P = 0.000, respectively). The mtDNA content was decreased in 82% of cancerous breast tissues compared with the normal ones. The changes were associated with hormone receptor status. Conclusion  Our finding suggests that decreased mtDNA content in breast cancer may have diagnostic and prognostic value for the disease.