共查询到20条相似文献,搜索用时 15 毫秒
1.
Sun Young Ahn Yon-Sik ChoiHyun-Jung Koo Jae Hoon JeongWook Ha Park Minseok KimYing Piao Youngmi Kim Pak 《Biochimica et Biophysica Acta (BBA)/General Subjects》2010
Background
Atherosclerosis is one of the major complications of diabetes, which may result from insulin resistance via mitochondrial dysfunction. Although a strong association between insulin resistance and cardiovascular disease has been suggested, it is not clear yet whether stress-inducing factors damage mitochondria and insulin signaling pathway in cardiovascular tissues.Methods
We investigated whether stress-induced mitochondrial dysfunction might alter the insulin/Akt signaling pathway in A10 rat vascular smooth muscle cells (VSMC).Results
The treatment of oxidized low density lipoprotein (oxLDL) decreased ATP contents, mitochondrial respiration activity, mRNA expressions of OXPHOS subunits and IRS-1/2 and insulin-mediated phosphorylations of Akt and AMP-activated protein kinase (AMPK). Similarly, dideoxycytidine (ddC), the mtDNA replication inhibitor, or rotenone, OXPHOS complex I inhibitor, inhibited the insulin-mediated pAkt while increased pAMPK regardless of insulin. Reciprocally, an inhibitor of Akt, triciribine (TCN), decreased cellular ATP contents. Overexpression of Akt dominant positive reversed the oxLDL- or ddC-mediated ATP decrease but AMPK activator did not. Akt activation also normalized the aberrant VSMC migration induced by ddC.Conclusions
Defective insulin signaling and mitochondrial function may collectively contribute to developing cardiovascular disease.General significance
Akt may be a possible therapeutic target for treating insulin resistance-associated atherosclerosis. 相似文献2.
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Beatriz Tavira Juan Gómez Carmen Díaz-Corte Laura LLobet Eduardo Ruiz-Pesini Francisco Ortega Eliecer Coto 《Gene》2014
Background and aims
Tacrolimus (Tac) is an immunosuppressive drug widely used to avoid organ rejection. New-onset diabetes after transplantation (NODAT) is a major complication among transplanted patients who receive Tac. The increased risk for NODAT could be partly mediated by the effect of Tac on mitochondria from pancreatic beta-cells. Common and rare mitochondrial DNA variants have been linked to the risk of diabetes. Our aim was to determine whether mtDNA polymorphisms/haplogroups were associated with NODAT in Tac-treated kidney transplanted.Methods
Seven polymorphisms that define the common European haplogroups were determined in 115 NODAT and 197 no-NODAT patients.Results
Haplogroup H was significantly more frequent in the NODAT group (50% vs. 35%; p = 0.01, OR = 1.82). There was no difference between patients without and with (n = 106) D2M prior to the transplant.Conclusions
Mitochondrial haplogroup H was associated with the risk for NODAT among Tac-treated transplanted patients. The reported differences between the mtDNA variants could explain the increased NODAT-risk among H-patients. 相似文献5.
LOX-1 – dependent mitochondrial DNA damage and NLRP3 activation during systemic inflammation in mice
Zufeng Ding Shijie Liu Xianwei Wang Sue Theus Yubo Fan Xiaoyan Deng Jawahar L. Mehta 《Biochemical and biophysical research communications》2014
Background
Lectin-like oxidized low-density lipoprotein scavenger receptor-1 (LOX-1) is known to be involved in many pathophysiological events, such as inflammation.Methods
To clarify the role of LOX-1 in mtDNA damage and NLRP3 inflammasome activation, we studied wild-type (WT) and LOX-1 knockout (KO) mice given thioglycollate, an inflammatory stimulus.Results
We observed intense inflammatory response (CD45 and CD68 expression) and mtDNA damage in spleen and kidneys of WT mice given thioglycollate. The abrogation of LOX-1 (use of LOX-1 knockout mice) reduced the inflammatory response as well as mtDNA damage (P < 0.05 vs. WT mice). We also observed that mice with LOX-1 deletion had markedly reduced expression of caspase-1 (P10 and P20 subunits) as well as cleaved IL-1β and IL-18. These mice also had much less mtDNA damage and only limited NLRP3 inflammasome expression.Conclusions
These in vivo observations indicate that LOX-1 plays a key role in mtDNA damage which then leads to NLRP3 inflammasome activation during inflammation. 相似文献6.
Hulya Azakli Candan Gurses Muzaffer Arikan Aydın Aydoseli Yavuz Aras Altay Sencer Aysen Gokyigit Bilge Bilgic Duran Ustek 《Gene》2013
Introduction
Hippocampal sclerosis is the most common lesion in patients with mesial temporal lobe epilepsy. Recently, there has been growing evidence on the involvement of mitochondria also in sporadic forms of epilepsy. In addition, it has been increasingly argued that mitochondrial dysfunction has an important role in epileptogenesis and seizure generation in temporal lobe epilepsy. Although mtDNA polymorphisms have been identified as potential risk factors for neurological diseases, the link between homoplasmy and heteroplasmy within tissues is not clear. We investigated whether mitochondrial DNA (mtDNA) polymorphisms are involved in a case report of a patient with mesial temporal lobe epilepsy-hippocampal sclerosis (MTLE-HS).Design
We report the whole genome mtDNA deep sequencing results and clinical features of a 36-year-old woman with MTLE-HS. We used pyrosequencing technology to sequence a whole mitochondrial genome isolated from six different regions of her brain and blood. To assess the possible role of mitochondrial DNA variations in affected tissues, we compared all specimens from different regions of the hippocampus and blood.Results
In total, 35 homoplasmic and 18 heteroplasmic variations have been detected in 6 different regions of the hippocampus and in blood samples. While the samples did not display any difference in homoplasmic variations, it has been shown that hippocampus regions contain more heteroplasmic variations than blood. The number of heteroplasmic variations was highest in the CA2 region of the brain and accumulated in ND2, ND4 and ND5 genes. Also, dentate and subiculum regions of the hippocampus had similar heteroplasmic variation profiles.Discussion
We present a new rare example of parallel mutation at 16223 position. Our case suggests that defects in mitochondrial function might be underlying the pathogenesis of seizures in temporal lobe epilepsy. 相似文献7.
Objective
To identify the mitochondrial DNA (mtDNA) single nucleotide polymorphisms (SNPs) in the control region and elucidate their role in metabolic phenotypes and oxidative stress.Methods
A total of 861 nondiabetic subjects were enrolled, including 250 impaired fasting glucose (IFG) and 370 obese subjects (body mass index [BMI] > 25 kg/m2). Antioxidant status presented as total free thiol level was determined from serum samples. DNA was extracted from peripheral blood leucocytes, and the sequences were analyzed using the DNASTAR software. SNPs were identified by comparison with the Cambridge Reference Sequence.Results
After adjusting odds ratios for age, sex, and BMI, the selected independently significant SNPs indicated 4 susceptible SNPs: SNP-16126C and SNP-16261T, which were related to abdominal obesity (P = 0.009; 0.06); SNP-16390A, related to hypertension (HTN) (P = 0.007); and SNP-16092C, related to decreased antioxidant capacity (P = 0.015). In the obese subgroup, 3 susceptible SNPs included SNP-16189C and SNP-16260T, which showed significantly higher IFG prevalence (P = 0.016 and 0.024, respectively), and SNP-16519C, which was significantly higher in the HTN group (P = 0.036). As to protective SNPs, 5 protective SNPs were identified in all subjects but only one SNP-16093C is consistent in obese group, which showed a significantly lower prevalence in patients with abdominal obesity and was associated with a higher antioxidant status (P < 0.001).Conclusion
SNPs in the mtDNA control region are associated with metabolic phenotypes and oxidative stress markers. Some SNPs are relating to the interaction between obesity and genetic factors. The beneficial effects of these protective SNPs were insignificant and some susceptible SNPs became dominant within the obese subgroup. Subjects harboring these SNPs should avoid excessive weight gain. 相似文献8.
Zhinan Ding Jingzhang Ji Guorong Chen Hezhi Fang Shihui Yan Lijun Shen Jia Wei Kaiyan Yang Jianxin Lu Yidong Bai 《Biochimica et Biophysica Acta (BBA)/General Subjects》2010
Background
Mitochondrial defects have been associated with various human conditions including cancers.Methods
We analyzed the mutations at the mitochondrial DNA (mtDNA) in patients with different thyroid lesions. In particular, in order to investigate if the accumulation of mtDNA mutations play a role in tumor progression, we studied the highly variable main control region of mtDNA, the displacement-loop (D-loop) in patients with non-tumor nodular goiters, with benign thyroid adenomas, and with malignant thyroid carcinomas. Total thyroid tumor or goiter samples were obtained from 101 patients, matched with nearby normal tissue and blood from the same subject.Results
Noticeably, mitochondrial microsatellite instability (mtMSI) was detected in 2 of 19 nodular goiters (10.53%), and 8 of 77 (10.39%) malignant thyroid carcinomas. In addition, 6 patients, including 5 (6.49%) with malignant thyroid carcinomas and 1 (5.26%) with nodular goiter, were found to harbor point mutations. The majority of the mutations detected were heteroplasmic.General significance
Our results indicate that mtDNA alterations in the D-loop region could happen before tumorigenesis in thyroid, and they might also accumulate during tumorigenesis. 相似文献9.
Background
Disorders of the mitochondrial respiratory chain are heterogeneous in their symptoms and underlying genetics. Simple links between candidate mutations and expression of disease phenotype typically do not exist. It thus remains unclear how the genetic variation in the mitochondrial genome contributes to the phenotypic expression of complex traits and disease phenotypes.Scope of review
I summarize the basic genetic processes known to underpin mitochondrial disease. I highlight other plausible processes, drawn from the evolutionary biological literature, whose contribution to mitochondrial disease expression remains largely empirically unexplored. I highlight recent advances to the field, and discuss common-ground and -goals shared by researchers across medical and evolutionary domains.Major conclusions
Mitochondrial genetic variance is linked to phenotypic variance across a variety of traits (e.g. reproductive function, life expectancy) fundamental to the upkeep of good health. Evolutionary theory predicts that mitochondrial genomes are destined to accumulate male-harming (but female-friendly) mutations, and this prediction has received proof-of-principle support. Furthermore, mitochondrial effects on the phenotype are typically manifested via interactions between mitochondrial and nuclear genes. Thus, whether a mitochondrial mutation is pathogenic in effect can depend on the nuclear genotype in which is it expressed.General significance
Many disease phenotypes associated with OXPHOS malfunction might be determined by the outcomes of mitochondrial–nuclear interactions, and by the evolutionary forces that historically shaped mitochondrial DNA (mtDNA) sequences. Concepts and results drawn from the evolutionary sciences can have broad, but currently under-utilized, applicability to the medical sciences and provide new insights into understanding the complex genetics of mitochondrial disease. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research. 相似文献10.
Yuko Kumamoto-Yonezawa Ryohei Sasaki Yosuke Ota Yoko Suzuki Shoji Fukushima Takahiko Hada Keisuke Uryu Kazuro Sugimura Hiromi Yoshida Yoshiyuki Mizushina 《Biochimica et Biophysica Acta (BBA)/General Subjects》2009
Background
Conjugated eicosapentaenoic acid (cEPA) containing conjugated double bonds, which is prepared by alkaline treatment of eicosapentaenoic acid (EPA), selectively inhibited the activities of both mammalian DNA polymerases (pols) and human DNA topoisomerases (topos).Methods
Human colon carcinoma cell line, HCT116, was cultured and performed drug and small interfering RNA (siRNA) treatment, flow cytometry analysis, BrdU incorporation analysis, and western blot analysis.Results
The levels of bromodeoxyuridine (BrdU) incorporation labeling during DNA synthesis were decreased in time- and dose-dependent manners in HCT116 cells, treated with cEPA. The level of chromatin association of RPA70, a subunit of the single-stranded DNA (ssDNA)-binding protein, was increased following cEPA exposure, suggesting that the replication forks were stalled in response to inhibition of replicative pol activity by cEPA in the cells. cEPA also induced the activation of ataxia-telangiectasia and Rad3-related (ATR) protein in HCT116 cells, and activated the G1 checkpoint pathway in the cells, which was down-regulated by a small interfering RNA (siRNA) against ATR protein. Moreover, caffeine, a known ATR kinase inhibitor, abrogated the cEPA-induced G1 checkpoint in HCT116 cells.General significance
cEPA could inhibit the activity of replicative pols, such as pols α, δ and ?, affect the DNA replication fork including ssDNA, and then activate the G1 checkpoint pathway by the induction of RPA and ATR expression levels in cancer cells. 相似文献11.
Objective
Individuals with chromosomal aneuploidies tend to develop malignancies. Telomerase is an enzyme complex that lengthens telomeres and has enhanced expression in numerous malignancies; one of its components is encoded by the TERC gene. In this study, we evaluated the TERC gene copy number in amniocytes from fetuses with aneuploidy, other than trisomy-21.Methods
In this prospective, basic research study, fluorescence in situ hybridization (FISH) for the TERC gene (3q26) was applied to amniocytes retrieved from 14 fetuses with various aneuploidies and from a control group of 6 fetuses with a normal karyotype, to determine the TERC gene copy number.Results
The percentage of cells with more than two copies of the TERC gene was lowest in the control group (x3 = 1.2 ± 0.4%; x4 = 0 ± 0%), higher in the sex chromosome aneuploidies (x3 = 4 ± 3%; x4 = 0.7 ± 0.95%) and even higher in trisomy 18 (x3 = 10.6 ± 2.3; x4 = 4.6 ± 1.8). The differences were statistically significant (P < 0.05).Conclusion
The TERC gene copy number is increased in aneuploid amniocytes, which demonstrates their genetic instability and is presumably related to their tendency to develop malignancies. 相似文献12.
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Sylvain Hanein Mathilde Garcia Lucas Fares-Taie Valérie Serre Yves De Keyzer Thierry Delaveau Isabelle Perrault Nathalie Delphin Sylvie Gerber Alain Schmitt Jean-Marc Masse Arnold Munnich Josseline Kaplan Frédéric Devaux Jean-Michel Rozet 《Biochimica et Biophysica Acta (BBA)/General Subjects》2013
Background
Hereditary optic neuropathies (HONs) are a heterogeneous group of disorders that affect retinal ganglion cells (RGCs) and axons that form the optic nerve. Leber's Hereditary Optic Neuropathy and the autosomal dominant optic atrophy related to OPA1 mutations are the most common forms. Nonsyndromic autosomal recessive optic neuropathies are rare and their existence has been long debated. We recently identified the first gene responsible for these conditions, TMEM126A. This gene is highly expressed in retinal cellular compartments enriched in mitochondria and supposed to encode a mitochondrial transmembrane protein of unknown function.Methods
A specific polyclonal antibody targeting the TMEM126A protein has been generated. Quantitative fluorescent in situ hybridization, cellular fractionation, mitochondrial membrane association study, mitochondrial sub compartmentalization analysis by both proteolysis assays and transmission electron microscopy, and expression analysis of truncated TMEM126A constructs by immunofluorescence confocal microscopy were carried out.Results
TMEM126A mRNAs are strongly enriched in the vicinity of mitochondria and encode an inner mitochondrial membrane associated cristae protein. Moreover, the second transmembrane domain of TMEM126A is required for its mitochondrial localization.Conclusions
TMEM126A is a mitochondrial located mRNA (MLR) that may be translated in the mitochondrial surface and the protein is subsequently imported to the inner membrane. These data constitute the first step toward a better understanding of the mechanism of action of TMEM126A in RGCs and support the importance of mitochondrial dysfunction in the pathogenesis of HON.General significance
Local translation of nuclearly encoded mitochondrial mRNAs might be a mechanism for rapid onsite supply of mitochondrial membrane proteins. 相似文献16.
Lei Sun Zuqian Fan Xunjin Weng Xuehe Ye Ju Long Kepeng Fu Shanhuo Yan Bo Wang Yongguang Zhuo Xinxing Liu Kegan Lao 《Gene》2014
Objective
Development of a qPCR test for the detection of trisomy 21 using segmental duplications.Methods
Segmental duplications in the TTC3 gene on chromosome 21 and the KDM2A gene on chromosome 11 were selected as molecular markers for the diagnostic qPCR assay. A set of consensus primers selected from the conserved regions of these segmental duplications were used to amplify internal diverse sequences that were detected and quantified with different probes labeled with distinct fluorescence. The copy numbers of these two fragments were determined based on the ΔCq values of qPCR. The results of qPCR for prenatal and neonatal screening of Down's syndrome were compared with the conventional karyotype analysis by testing 82 normal individuals and 50 subjects with Down's syndrome.Results
The ΔCq values of segmental duplications on chr21 and 11 ranged between 0.33 and 0.75 in normal individuals, and between 0.91 and 1.18 in subjects with Down's syndrome. The ΔCq values of these two segmental duplications clearly discriminated Down's syndrome from normal individuals (P < 0.001). Furthermore, the qPCR results were consistent with karyotype analysis.Conclusion
Our qPCR can be used for rapid prenatal and neonatal screening of Down's syndrome. 相似文献17.
Jafar Mohseni Chia Boon Hock Che Abdul Razak Syah Nor Iman Othman Fatemeh Hayati Winnie Ong PeiTee Muzhirah Haniffa Bin Alwi Zilfalil Rowani Mohd. Rawi Lock-Hock Ngu Teguh Haryo Sasongko 《Gene》2014
Background
Hyperargininemia is a very rare progressive neurometabolic disorder caused by deficiency of hepatic cytosolic arginase I, resulting from mutations in the ARG1 gene. Until now, some mutations were reported worldwide and none of them were of Southeast Asian origins. Furthermore, most reported mutations were point mutations and a few others deletions or insertions.Objective
This study aims at identifying the disease-causing mutation in the ARG1 gene of Malaysian patients with hyperargininemia.Methodology
We employed a series of PCR amplifications and direct sequencing in order to identify the mutation. We subsequently used quantitative real-time PCR to determine the copy number of the exons flanking the mutation. We blasted our sequencing data with that of the reference sequence in the NCBI in order to obtain positional insights of the mutation.Results
We found a novel complex re-arrangement involving insertion, inversion and gross deletion of ARG1 (designated g.insIVS1 + 1899GTTTTATCAT;g.invIVS1 + 1933_ + 1953;g.delIVS1 + 1954_IVS2 + 914;c.del116_188;p.Pro20SerfsX4) commonly shared by 5 patients with hyperargininemia, each originating from different family. None of the affected families share known relationship with each other, although four of the five patients were known to have first-cousin consanguineous parents.Conclusion
This is the first report of complex re-arrangement in the ARG1. Further analyses showing that the patients have shared the same geographic origin within the northeastern part of Malaysia prompted us to suggest a simple molecular screening of hyperargininemia within related ethnicities using a long-range PCR. 相似文献18.
Background
The prevalence of type 2 diabetes is rapidly increasing world-wide and insulin resistance is central to the aetiology of this disease. The biology underpinning the development of insulin resistance is not completely understood and the role of impaired mitochondrial function in the development of insulin resistance is controversial.Scope of review
This review will provide an overview of the major processes regulated by mitochondria, before examining the evidence that has investigated the relationship between mitochondrial function and insulin action. Further considerations aimed at clarifying some controversies surrounding this issue will also be proposed.Major conclusions
Controversy on this issue is fuelled by our lack of understanding of some of the basic biological interactions between mitochondria and insulin regulated processes in the context of insults thought to induce insulin resistance. Aspects that have not yet been considered are tissue/cell type specific responses, mitochondrial responses to site-specific impairments in mitochondrial function and as yet uncharacterised retrograde signalling from mitochondria.General significance
Further investigation of the relationship between mitochondria and insulin action could reveal novel mechanisms contributing to insulin resistance in specific patient subsets. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research. 相似文献19.
Shi-Bei Wu Yu-Ting Wu Tsung-Pu Wu Yau-Huei Wei 《Biochimica et Biophysica Acta (BBA)/General Subjects》2014
Background
Mitochondrial DNA (mtDNA) mutations are an important cause of mitochondrial diseases, for which there is no effective treatment due to complex pathophysiology. It has been suggested that mitochondrial dysfunction-elicited reactive oxygen species (ROS) plays a vital role in the pathogenesis of mitochondrial diseases, and the expression levels of several clusters of genes are altered in response to the elevated oxidative stress. Recently, we reported that glycolysis in affected cells with mitochondrial dysfunction is upregulated by AMP-activated protein kinase (AMPK), and such an adaptive response of metabolic reprogramming plays an important role in the pathophysiology of mitochondrial diseases.Scope of review
We summarize recent findings regarding the role of AMPK-mediated signaling pathways that are involved in: (1) metabolic reprogramming, (2) alteration of cellular redox status and antioxidant enzyme expression, (3) mitochondrial biogenesis, and (4) autophagy, a master regulator of mitochondrial quality control in skin fibroblasts from patients with mitochondrial diseases.Major conclusion
Induction of adaptive responses via AMPK–PFK2, AMPK–FOXO3a, AMPK–PGC-1α, and AMPK–mTOR signaling pathways, respectively is modulated for the survival of human cells under oxidative stress induced by mitochondrial dysfunction. We suggest that AMPK may be a potential target for the development of therapeutic agents for the treatment of mitochondrial diseases.General significance
Elucidation of the adaptive mechanism involved in AMPK activation cascades would lead us to gain a deeper insight into the crosstalk between mitochondria and the nucleus in affected tissue cells from patients with mitochondrial diseases. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research. 相似文献20.