Relationship between Sestrin2 and mtDNA-NLRP3 inflammasome pathway during endotoxin-induced myocardial injury in mice / 中华麻醉学杂志

Objective:To evaluate the relationship between Sestrin2 and mitochondrial DNA (mtDNA)-NOD-like receptor associated protein 3 (NLRP3) inflammasome pathway during endotoxin-induced myocardial injury in mice.Methods:One hundred and eighty-four clean-grade healthy male ICR mice, aged 8-12 weeks, weighing 20-25 g, were used in this study. One hundred and sixty-eight mice were divided into 7 groups ( n=24 each) using the random number table method: normal control group (N group), lipopolysaccaride(LPS) group (L group), mtDNA group, LPS+ mtDNA group (M group), normal control+ negative control adeno-associated virus (AAV-NC)group (NC group), LPS+ mtDNA+ AAV-NC group (MC group), and LPS+ mtDNA+ Sestrin2 overexpression adeno-associated virus (AAV-Sestrin2) group (MSgroup). Another 10 mice were used to detect the transfection effect of AAV-Sestrin2, and the left 6 mice were used for mtDNA extraction. The model of endotoxemia was developed by intraperitoneal injection of LPS 10 mg/kg. mtDNA 5 mg/kg was intraperitoneally injected in mtDNA group, and mtDNA 5 mg/kg was intraperitoneally injected at 30 min after LPS injection in M group.AAV-Sestrin2 150 μl was injected via the tail vein in MS group, and the equal volume of AAV-NC was injected via the tail vein in MC and NC groups. Four weeks after virus injection, LPS 10 mg/kg was intraperitoneally injected and 30 min later mtDNA 5 mg/kg was intraperitoneally injected in MS and MC groups. Blood samples were collected at 24 h after LPS injection for determination of serum creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) activities (by biochemical assay), concentrations of serum cardiac troponin I (cTnI), interleukin-18 (IL-18) and interleukin-1beta (IL-1β)(by enzyme-linked immunesorbent assay), and expression of mtDNA (by quantitative real-time polymerase chain reaction). The animals were sacrificed after the end of blood sampling and myocardial tissues were obtained for determination of the contents of reactive oxygen species (ROS), total antioxidant capacity (T-AOC), and adenosine triphosphate (ATP) and expression of NOD-like receptor associated protein 3 (NLRP3), active subunit p20 of caspase-1 (caspase-1p20) and apoptosis-associated microprotein (ASC) in myocardial tissues (by Western blot) and for microscopic examination of the pathological changes after HE staining (with a light microscope). Results:Compared with N group, the levels of CK-MB, LDH, cTnI, IL-1β and IL-18 in serum were significantly increased, the expression of mtDNA was up-regulated, the ROS content in myocardial tissues was increased, the T-AOC and ATP contents in myocardial tissues were decreased, the expression of NLRP3, caspase-1p20 and ASC in the myocardial tissues was up-regulated( P<0.05), and the pathological changes of myocardial tissues were aggravated in L group and mtDNA group.Compared with L group and mtDNA group, the levels of CK-MB, LDH, cTnI, IL-1β and IL-18 in serum were significantly increased, the expression of mtDNA was up-regulated, the ROS content in myocardial tissues was increased, the T-AOC and ATP contents in myocardial tissues were decreased, the expression of NLRP3, caspase-1p20 and ASC in the myocardial tissues was up-regulated( P<0.05), and the pathological changes of myocardial tissues were aggravated in M group. Compared with M group, the levels of CK-MB, LDH, cTnI, IL-1β and IL-18 in serum were significantly decreased, the expression of mtDNA was down-regulated, the ROS content in myocardial tissues was decreased, the T-AOC and ATP contents in myocardial tissues were increased, the expression of NLRP3, caspase-1p20 and ASC in the myocardial tissues was down-regulated( P<0.05), and the pathological changes of myocardial tissues were significantly attenuated in MS group. Conclusions:Sestrin2 can reduce endotoxin-induced myocardial injury in mice by alleviating mitochondrial damage, inhibiting oxidative stress, protecting mtDNA from oxidative damage, and then inhibiting mtDNA-NLRP3 inflammasome pathway.

Age-related change in mitochondrial DNA copy number and its correlation with intrinsic capacity and body composition / 中华老年医学杂志

Objective:To investigate the correlation of peripheral blood relative mitochondrial DNA copy number(mtDNAcn)with intrinsic capacity and body composition, and to identify potential biomarkers for healthy aging.Methods:Clinical data of 416 patients admitted to our hospital from September 2019 to June 2021 were consecutively collected.MtDNA was extracted from peripheral blood of these subjects, and mtDNAcn was determined by a real-time fluoresence quantitative reverse transcription-polymerase chain reaction(qRT-PCR). Intrinsic capacity assessment included 5 aspects that were exercise[Morse Fall Scale(MFS), Physiological Frailty Phenotype(PFP), Sarcopenia Questionnaire(SARC-CALF), Short Physical Performance Battery(SPPB), Time Up and Go Test(TUG)]; vitality[Mini Nutritional Assessment(MNA), Multidimensional Prognostic Index(MPI)]; cognition[Mini-Mental State Examination(MMSE)scale]; psychology[Geriatric Depression Scale(GDS), Self-rating Anxiety Scale(SAS)]; sensory capacities[Cumulative Illness Rating Scale-the Comorbidity Index(CIRS-CI)]. To assess body composition, dual-energy X-ray absorptiometry was used to measure body fat, including trunk fat, total body fat, fat in the abdominal region, fat in the buttock region, and then to calculate fat index(FMI)and limb skeletal muscle mass index(ASMI).Results:Spearman correlation analysis showed that mtDNAcn had a negatively correlation with age( r=-0.176, P<0.05). After adjustment for gender and body mass index, partial correlation analysis showed mtDNAcn were still negatively correlated with age( r=-0.144, P<0.05). Furthermore, mtDNAcn was significantly correlated with 4 m gait speed, the scores of SARC-CalF, MFS, MNA, MMSE, MPI and its sub-scale's Activities of Daily Living(ADL)and Short Portable Mental Status Questionnaire(SPMSQ)( r=0.171, -0.207, -0.163, 0.221, 0.184, -0.210, 0.241, -0.269, all P<0.05). After adjustment for age, gender and body mass index, partial correlation analysis showed mtDNAcn still had a significant correlation with gait speed, the scores of MFS, MNA, MPI and SPMSQ( r=0.170, -0.170, 0.148, -0.242, -0.188, all P<0.05). In addition, the Spearman correlation analysis showed that mtDNAcn was positively correlated with FMI, trunk fat, total body fat, abdominal fat and fat in the buttock region( r=0.168, 0.143, 0.175, 0.116, 0.199, all P<0.05). However, after adjustment for age and gender, mtDNAcn was only correlated with FMI, total body fat, fat in the buttock region( r=0.126, 0.131, 0.127, all P<0.05). On the other hand, multiple linear regression analysis showed that mtDNAcn was significantly correlated with age, gait speed, FMI, total body fat, fat in the buttock region, the scores of MFS, PFP, MNA and MPI( β=-0.191, 0.156, 0.126, 0.131, 0.125, -0.119, -0.145, 0.151, -0.171, all P<0.05). Conclusions:MtDNAcn is correlated with physical function, frailty, nutrition, falling, cognition and body composition, and may be considered as a biomarker for the evaluation of the locomotion and vitality of human intrinsic capacity.

Gene therapy for Leber hereditary optic neuropathy / 中华眼底病杂志

Leber hereditary optic neuropathy (LHON) is a matrilineal hereditary optic neuropathy in which mitochondrial DNA mutations lead to retinal ganglion cell degeneration. At present, the treatment for LHON is limited. Early symptomatic treatment and medical treatment may improve the vision of patients. In recent years, rapid progress has been made in gene therapy. Many clinical studies have confirmed its safety and efficacy. Monocular gene therapy is helpful to improve the visual function of LHON patients, and it can also improve the visual acuity of uninjected eyes. Patients do not have serious eye or systemic adverse events during the treatment period, showing good safety and tolerance. Studies with larger sample size and longer follow-up time are needed to further verify the efficacy and safety of gene therapy in the future. Gene therapy is expected to become a safe and effective treatment, bringing hope to LHON patients.

Mitochondrial DNA Heteroplasmy of Hair Shaft Using HID Ion GeneStudioTM S5 Sequencing System / 法医学杂志

Objective To study the heteroplasmy of the whole mitochondrial genome genotyping result of hair shaft samples using HID Ion GeneStudioTM S5 Sequencing System. Methods The buccal swabs and blood of 8 unrelated individuals, and hair shaft samples from different parts of the same individual were collected. Amplification of whole mitochondrial genome was performed using Precision ID mtDNA Whole Genome Panel. Analysis and detection of whole mitochondrial genome were carried out using the HID Ion GeneStudioTM S5 Sequencing System. Results The mitochondrial DNA sequences in temporal hair shaft samples from 2 individuals showed heteroplasmy, while whole mitochondrial genome genotyping results of buccal swabs, blood, and hair samples from the other 6 unrelated individuals were consistent. A total of 119 base variations were observed from the 8 unrelated individuals. The numbers of variable sites of the individuals were 29, 40, 38, 35, 13, 36, 40 and 35, respectively. Conclusion Sequence polymorphism can be fully understood using HID Ion GeneStudioTM S5 Sequencing system.

Research progress in cell and animal models of Leber hereditary optic neuropathy / 中华眼底病杂志

Leber hereditary optic neuropathy (LHON) is a blinding disease caused by mutations in mitochondrial DNA. It is a classic disease model for studying mitochondrial abnormalities. Its main mutation sites are m11778G.A, m.3460G.A and m.14484T.C. LHON cell models are mainly produced by lymphoblasts, fibroblasts, cell hybrids and induced pluripotent stem cells, while LHON animal models are mainly mice, which are produced by rotenone and ND4 mutants. Although the research on the LHON model has achieved good results, there are still many difficulties in constructing an ideal experimental model, which severely limit the exploring to the pathogenesis and therapeutic drugs of LHON. A detailed understanding of the application and characteristics of existing models in LHON will help improve experimental design and construct new models.

Application of Multiple Genetic Markers in Determination of Full and Half Sibling Relationship： A Case Report / 法医学杂志

Objective To investigate the application of the comprehensive use of multiple genetic markers in full and half sibling relationship testing through the identification of a case of suspected sibling relationship. Methods Genomic DNA were extracted from bloodstain samples from 4 subjects （ZHANG-1, ZHANG-2, male; ZHANG-3, ZHANG-4, female）. Autosomal STR loci, X-STR, Y-STR loci and polymorphisms of mtDNA HV-Ⅰ and Ⅱwere genotyped by EX20 STR kit, X19 kit, Data Y24 STR kit, and Sanger sequencing, respectively. Results According to autosomal STR based IBS scoring results, full sibling relationships were indicated among ZHANG-2, ZHANG-3 and ZHANG-4, but those were not indicated between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4. According to autosomal STR based FSI and HSI, with ITO method and discriminant function method, full sibling relationships among ZHANG-2, ZHANG-3 and ZHANG-4 were indicated, and half sibling relationships between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4 were also indicated. X-STR and mtDNA sequencing results showed that all the 4 samples came from a same maternal line, and Y-STR results showed that ZHANG-1 and ZHANG-2 did not come from a same paternal line, which supported the half sibling relationship between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4, verified by parental genotype reconstruction based on autosomal STR genotyping. Conclusion For the identification of sibling relationships, it is effective to have reliable results with the mutual verification and support of multiple genetic markers （autosomal STR, sex chromosomal STR and mtDNA sequence） and calculations （IBS, ITO, discriminant function method and family reconstruction）.

Phylogenetic signal at the Cytb-SertRNA-IG1-ND1 mitochondrial region in Anopheles (Kerteszia) neivai Howard, Dyar & Knab, 1913 / Señal filogenética de la región Cytb- SertRNA -IG1-ND1 en Anopheles (Kerteszia) neivai Howard, Dyar & Knab, 1913

Abstract Introduction: Mitochondrial DNA has proven its utility for the study of insect evolution. Genes such as cytochrome b (Cytb) and the transfer gene for serine (SertRNA) can be used to compare closely related organisms. Objective: The phylogenetic utility of Cytb-SertRNA-IG1-ND1 was tested for polymorphisms, and secondary structure modeling in SertRNA was done to detect possible cryptic species in Anopheles neivai. Materials and methods: Specimens from Colombia, Guatemala, and the type locality in Panamá were collected and sequenced for specimen comparison based on DNA polymorphisms, and secondary structure modeling for the SertRNA gene. Results: Thirty-six sequences for A. neivai and A. pholidotus were obtained. Conclusions: Polymorphic variants were detected in A. neivai for Cytb-SertRNA-IG1- ND1. Despite this variation in A. neivai, cryptic species could not be detected.

Resumen Introducción. El ADN mitocondrial ha demostrado su utilidad para el estudio de la evolución en los insectos. Existen algunos genes mitocondriales como el citocromo b (Cytb) y el gen de transferencia para el aminoácido serina (SertRNA) que pueden usarse en el diagnóstico de especies estrechamente relacionadas. Objetivo. Explorar la utilidad filogenética de la región Cytb-SertRNA-IG1-ND1 para detectar posibles especies crípticas en Anopheles neivai. Materiales y métodos. Se recolectaron especímenes en Colombia, Guatemala y en la localidad tipo en Panamá, los cuales se secuenciaron y se compararon mediante el polimorfismo de ADN en toda la región y mediante la simulación de estructuras secundarias del gen SertRNA. Resultados. Se obtuvieron las secuencias de especímenes de A. neivai (34) y A. pholidotus (2). Conclusiones. Se detectaron algunos polimorfismos para la regiónCytb-SertRNA-IG1-ND1 en A. neivai, pero no así especies crípticas.

Whole Genome Sequencing of Human mtDNA Based on Ion Torrent PGMTM Platform / 法医学杂志

Objective To analyze and detect the whole genome sequence of human mitochondrial DNA (mtDNA) by Ion Torrent PGMTM platform and to study the differences of mtDNA sequence in different tissues.Methods Samples were collected from 6 unrelated individuals by forensic postmortem examination,including chest blood,hair,costicartilage,nail,skeletal muscle and oral epithelium.Amplification of whole genome sequence of mtDNA was performed by 4 pairs of primer.Libraries were constructed with Ion ShearTM Plus Reagents kit and Ion Plus Fragment Library kit.Whole genome sequencing of mtDNA was performed using Ion Torrent PGMTM platform.Sanger sequencing was used to determine the heteroplasmy positions and the mutation positions on HV Ⅰ region.Results The whole genome sequence of mtDNA from all samples were amplified successfully.Six unrelated individuals belonged to 6 different haplotypes.Different tissues in one individual had heteroplasmy difference.The heteroplasmy positions and the mutation positions on HV I region were verified by Sanger sequencing.After a consistency check by the Kappa method,it was found that the results of mtDNA sequence had a high consistency in different tissues.Conclusion The testing method used in present study for sequencing the whole genome sequence of human mtDNA can detect the heteroplasmy difference in different tissues,which have good consistency.The results provide guidance for the further applications of mtDNA in forensic science.

Clinical, myopathological and genetic research of a patient with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes/Leigh syndrome overlap syndrome caused by m.10158 T>C mutation / 中华神经科杂志

Objective To report the clinical, myopathological and genetic features of a patient with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS)/Leigh syndrome (LS) overlap syndrome who carried m.10158 T>C mutation. Methods The patient′s clinical and imaging materials were collected. An open biopsy of right biceps brachii was performed. DNA samples were prepared from the patient and her mother′s blood. Direct sequencing of the complete mitochondrial genome was performed to detect the mtDNA mutation.Western blotting was used to estimate the content of respiratory complexes in the patient′s muscle. Results The patient was a 40-year-old female. She had seizures and lost consciousness for 9 months. Brain MRI findings consisted of asymmetrical lesions in the cerebral cortex of the frontal and temporal lobes, as well as symmetrical lesions bilaterally in the basal ganglia. Muscle biopsy showed typical ragged red fibers. Direct sequencing of the complete mitochondrial genome from blood and muscle of the patient revealed the T-to-C transition at nucleotide position 10158 in the MT-ND3 gene.The mutation rate was 9.31% and 70.0%, respectively.Western blotting demonstrated that the contents of complexes Ⅰ and Ⅳ were significantly lower in the patient′s muscle mitochondria compared with the normal controls (53.1%±1.2% vs 88.6%±1.7%, t=4.08, PC mutation in MT-ND3 gene and DNA test is very important for the diagnosis of the disease.

Relationship between mitochondrial DNA copy number, membrane potential of human embryo and embryo morphology / 中华妇产科杂志

Objective To explore the relationship between the embryo with the different morphological types in the third day and its mitochondrial copy number,the membrane potential.Methods Totally 117 embryos with poor development after normal fertilization and were not suitable transferred in the fresh cycle and 106 frozen embryos that were discarded voluntarily by infertility patients with in vitro fertilization-embryo transfer after successful pregnancy were selected.According to evaluation of international standard in embryos,all cleavage stage embryos were divided into class Ⅰ frozen embryo group (n=64),class Ⅱ frozen embryo group (n=42) and class Ⅲ fresh embryonic group (not transplanted embryos;n=117).Real-time PCR and confocal microscopy methods were used to detect mitochondrial DNA (mtDNA) copy number and the mitochondrial membrane potential of a single embryo.The differences between embryo quality and mtDNA copy number and membrane potential of each group were compared.Results The copy number of mtDNA and the mitochondrial membrane potential in class Ⅲ fresh embryonic group [(1.7± 1.0)× 105 copy/μl,1.56±0.32] were significantly lower than those in class Ⅰ frozen embryo group [(3.4±1.7)×105 copy/μl,2.66±0.21]and class Ⅱ frozen embryo group [(2.6± 1.2)× 105 copy/μl,1.80±0.32;all P＜0.05].The copy number of mtDNA and the mitochondrial membrane potential in class Ⅰ frozen embryo group were significantly higher than those in class Ⅱ frozen embryo group (both P＜0.05).Conclusion The mtDNA copy number and the mitochondrial membrane potential of embryos of the better quality embryo are higher.

Correlation between heteroplasmy level of the 5178C＞A mutation in the ND2 gene of mitochondria DNA and essential hypertension in middle-aged and elderly adults / 中华老年医学杂志

Objectives To explore the correlation between the heteroplasmy level of mt5178C＞A mutation in ND2 gene of mitochondria DNA and essential hypertension(EH)in middle-aged and elderly adults.Methods EH patients and normotensive controls were recruited consecutively from 2014-2015 from general population.Demographics,clinical characteristics and blood leukocytes were collected.The mt5178C＞A mutation heteroplasmy level was quantified by the rapid and sensitive realtime polymerase chain reaction(PCR) method for each participant.Results A total of 108 EH patients and 109 controls were recruited.The mt5178C＞A mutation heteroplasmy level was(42 ± 11％)in EH patients and (54± 13)％ in control subjects,with statistically significant difference between the two groups(P＜0.01).Using a two-step cluster analysis,the mt5178C＞A heteroplasmy level exceeding 44％ was associated with a decreased risk of EH(OR=0.18,95％,CI:0.10-0.31,P＜0.01).Correlation analysis showed mt5178C＞ A heteroplasmy level was significantly negatively correlated with both systolic blood pressure (r =-0.38,P＜ 0.001) and diastolic blood pressure (r =-0.49,P＜ 0.01)in 109 controls.Logistic regression analysis demonstrated that in single-factor analysis,mt5178C ＞ A heteroplasmy level (OR =0.82,95 ％ CI:0.77 0.87,P ＜ 0.01) was protective factor for EH,however,BMI(OR=1.30,95％CI:1.12-1.45,P＜0.01),total cholesterol(OR=2.13,95％CI:1.39-3.28,P=0.00),triglyceride(OR=7.62,95％CI:3.45-16.84,P＜0.01)and blood urea nitrogen(OR =1.35,95 ％ CI,P =0.03) were risk factors for EH.And a multiple logistic regression analysis showed that mt5178C＞ A heteroplasmy level (OR =0.83,95 ％ CI:0.78-0.89,P＜ 0.01) was independent protective factor for E H,however,only total cholesterol (OR =2.17,95 ％ CI:1.58-2.98,P =0.02) and low density lipoprotein cholesterol (OR =0.06,95％ CI:0.01-0.83,P =0.04) were independent risk factors for EH,and the P at critical 0.05 value.Conclusions Mitochondrial ND2 gene 5178C＞ A mutation heteroplasmy level exerts protective role against EH in middle-aged and elderly adults in Chinese population.

The advances and new technologies for the study of mitochondrial diseases / Avanços e novas tecnologias para o estudo das doenças mitocondriais

ABSTRACT Genetic mitochondrial disorders are responsible for the most common inborn errors of metabolism, caused by mutations in either nuclear genes or in mitochondrial DNA. This article presents the prokaryotic origin of the organelle and the relation between nuclear and mitochondrial genomes, as well as current evolutionary models for such mechanisms. It also addresses the structure of mitochondrial genes, their expression pattern, clinical features of gene defects, risk of transmission and current techniques to avoid these events in assisted human reproduction. Finally, it discusses the ethical implications of these possibilities.

RESUMO As doenças genéticas mitocondriais são responsáveis pelos erros inatos do metabolismo mais comuns, causados por mutações tanto em genes nucleares como no DNA mitocondrial. Este artigo apresenta a origem procariótica dessa organela, e a relação entre os genomas nuclear e mitocondrial, bem como modelos evolutivos correntes para esses mecanismos. Também trata da estrutura dos genes mitocondriais, seu padrão de expressão, características clínicas de defeitos genéticos, riscos de transmissão e técnicas atualmente utilizadas para evitar esses eventos em reprodução humana assistida. Finalmente, discute as implicações éticas dessas possibilidades.

Molecular identification of the species of Biomphalaria snails in Shenzhen reservoir based on 16S rDNA sequences / 中华地方病学杂志

Objective To identify the species of Biomphalaria snails collected in Shenzhen reservoir,based on the mitochondrial 16S rDNA sequences.Methods The 16S rDNA fragments were amplified by PCR from the genome DNA of Biomphalaria snails,and inserted in plasmid pMD-18T for sequencing.The sequence of 16S rDNA fragment and its phylogenetic relationships with those of other species of Biomphalaria snails were analyzed with BLAST and MEGA4 software.Results The amplified 16S rDNA fragment of the Biomphalaria snails was about 466 bp in length.As aligned with the corresponding sequences of the related Biomphalaria species,the identity of nucleotides was 99％ with 1 isolate of Biomphaltria straminea (B.straminea),98％ with 3 isolates of B.kuhniana,95％ with 1 isolate of B.intermedia,and 94％ with 1 isolate of B.edisoni.Based on the 16S rDNA sequence,the results of phylogenetic analysis with neighbor-joining (NJ) and unweighted pair-group method with arithmetic means (UPGMA) indicated that the snails had close genetic relationships with the B.straminea isolate (Genbank accession NO.AY030213.1) Conclusion The Biomphalaria snails collected in Shenzhen reservoir could be classified as B.straminea based on the characteristics of 16S rDNA sequence.

Effects of inflammatory markers on the level of reactive oxygen species and mitochondria DNA copy numbers in granulosa cells of patients without PCOS / 天津医药

Objective To study the effect of inflammatory markers on the level of reactive oxygen species (ROS) and mitochondrial DNA (mtDNA) copy numbers in granulosa cells of patients without polycystic ovary syndrome (PCOS). Methods Fifty patients without PCOS treated with in vitro fertilization and embryo transfer (IVF-ET) were selected in this study. The granulosa cells were extracted and cultured in vitro. Cells were randomly divided into treatment group and control group. The 5 nmol/L interleukin (IL)-1, IL-6 and tumor necrosis factor (TNF)-αwere given to treatment group, and same amount of inflammatory diluted solution was added to control group. The levels of ROS and copy numbers of mtDNA were compared between two groups. Results The ROS levels and mtDNA copy number of granulosa cells were significantly higher in IL-1, IL-6 and TNF-αtreatment groups than those of control group (P<0.05). Conclusion Inflammatory markers of IL-1, IL-6 and TNF-αincrease the level of ROS and damage mtDNA in granulosa cells.

Relationship between mitochondrial DNA alteration and gastric cancer / 国际肿瘤学杂志

Mitochondrial DNA (mtDNA) is more susceptible to oxidative damage and has a higher mutation rate compared with nuclear DNA due to the absence of protective histone proteins and imperfect repair system.Somatic alterations in mtDNA have been proposed to contribute to initiation and progression of human cancer in previous researches.However,the role of these mtDNA alterations in gastric cancer progression remains unclear.Point mutations and mtDNA content alterations are the two most common mtDNA alterations that result in mitochondrial dysfunction in gastric cancers.Identifing somatic mtDNA alterations in gastric cancers as well as their association with the clinicopathological parameters of gastric cancer,and exploring the causative factors of the somatic mtDNA alterations in cancer progression have been a new direction of gastric cancer research in recent years.

Genetic differentiation in the populations of red piranha, Pygocentrus nattereri Kner (1860) (Characiformes: Serrasalminae), from the river basins of northeastern Brazil / Diferenciação genética em populações da piranha vermelha, Pygocentrus nattereri Kner (1860) (Characiformes: Serrasalminae), em bacias hidrográficas do nordeste do Brasil

Abstract The red piranha, Pygocentrus nattereri, is an important resource for artisanal and commercial fisheries. The present study determines the genetic differentiation among P. nattereri populations from the northeastern Brazilian state of Maranhão. The DNA was isolated using a standard phenol-chloroform protocol and the Control Region was amplified by PCR. The PCR products were sequenced using the didesoxyterminal method. A sequence of 1039 bps was obtained from the Control Region of 60 specimens, which presented 33 polymorphic sites, 41 haplotypes, һ =0.978 and π =0.009. The neutrality tests (D and Fs) were significant (P < 0.05) for most of the populations analyzed. The AMOVA indicated that most of the molecular variation (72%) arises between groups. The fixation index was highly significant (FST = 0.707, P < 0.00001). The phylogenetic analyses indicated that the specimens represented a monophyletic group. Genetic distances between populations varied from 0.8% to 1.9%, and were <0.5% within populations. The degree of genetic differentiation found among the stocks of P. nattereri indicates the need for the development of independent management plans for the different river basins in order to preserve the genetic variability of their populations.

Resumo A piranha vermelha, Pygocentrus nattereri, é um recurso importante para pesca artesanal e comercial. O presente estudo determinou a diferenciação genética entre populações de P. nattereri no nordeste do estado brasileiro do Maranhão. O DNA foi isolado utilizando o protocolo de Fenol-clorofórmio e a Região Controle foi amplificada por PCR. Os produtos da PCR foram sequenciados usando o método didesoxiterminal. Uma sequência de 1039 pbs foi obtida da Região Controle de 60 espécimes, que apresentaram 33 sítios polimórficos, 41 haplótipos, һ= 0.978 e π= 0.009. Os testes de neutralidade (D and Fs) foram significativos (P < 0.05) para a maioria das populações analisadas. A AMOVA indicou que a maior parte da variação molecular (72%) surge entre os grupos. O índice de fixação foi altamente significativo (FST = 0.707, P = < 0.00001). As análises filogenéticas indicaram que os espécimes representam um grupo monofilético. Distâncias genéticas entre as populações variaram de 0.8% a 1.9%, e de <0.5% dentro das populações. O grau de diferenciação genética encontrada entre os estoques de P. nattereri indicam a necessidade para o desenvolvimento de planos de manejo independentes para as diferentes bacias hidrográficas, a fim de preservar a variabilidade genética dessas populações.

La mitocondria en la medicina legal y forense / The Mitochondrion in legal and forensic medicine

Las mitocondrias son las organelas intracelulares encargadas de suministrar la mayor parte de la energía necesaria para la actividad celular. Actúan, por lo tanto, como centrales energéticas de la célula y sintetizan ATP a expensas de los sustratos metabólicos. La intoxicación con ácido cianhídrico inhibe estos mecanismos y las alteraciones en el funcionamiento del metabolismo mitocondrial de origen genético o congénito producen innumerables patologías. El conocimiento de las patologías y disfunción de las mitocondrias es de importancia para realizar correctamente el diagnóstico de las causas de muerte. El ADN mitocondrial es de suma importancia en la medicina legal y forense para la identificación de las personas.

Mitochondria are organelles in the cell cytoplasm which supply most of the energy needed for cellular activity. They behave as cell’s power plants and synthesize ATP using metabolic substrates. Intoxication with Hydrocyanic Acid inhibits the synthesis of ATP, generating alterations in the mitochondrial metabolism, either genetic or congenital. The consequences of those alterations are innumerables pathologies. Understanding the pathologies and malfunctions of mitochondria help us to make the right diagnostic about the cause of death. In forensic medicine, mitochondrial DNA is of paramount relevance to people identification.

Significance of mtDNA expression in acute peritonitis induced by monosodium urate in mice / 中华风湿病学杂志

Objective To establish acute peritonitis induced by monosodium urate (MSU) of in mice and observe the significance of mitochondrial deoxyribonucleic acid (mtDNA) expression in the inflammatory processes.Methods The mouse models of acute peritonitis were made by intraperitoneal injection of MSU.Sixty-four male C57BL16 mice were randomly divided into the MSU group which were treated with 0.2 ml of 15 mg/ml MSU solution by i.p.injection and the control group which were treated with 0.2 ml of PBS.Respectively four mice from MSU group and four mice from control group were killed 2 hours, 4 hours, 6 hours, 8 hours 12 hour, 16 hours, 20 hours and 24 hours later and whole blood, peritoneal lavage and peritoneum were collected respectively.Four the mice from the MSU group and four mice from the control group were killed and whole blood, peritoneal lavage and peritoneum were collected.Immunoflourescence study of peritoneum tissues was performed.The levels of interleukin (IL)-1β, IL-18 in plasma and peritoneal lavage were examined by enzyme linked immunosorbent assay (ELISA).DNA was extracted from blood and peritoneal lavage, and mtDNA level was detected by using real-time polymerase chain reaction (PCR).The data was analyszied by multivariate analysis of variance.Results As compared with those killed at other time points from the MSU groups and the control group, the levels of IL-1β [(27.0±2.0) pg/ml vs (26.8±2.1) pg/ml], IL-18 [(673±454) pg/ml vs(752±495) pg/ml] in plasma and peritoneal lavage were increased progressively in those which were killed after i.p.injection of 2 hours and 4 hours from in the MSU group (F=22.778, P＜0.05;F=6.660, P＜0.05).The mtDNA in plasma and peritoneal lavage of the mice began to be expressed 4 hours after i.p.injection 4 hours from in the MSU group.The peak level was detected in those i.p.injected MSU 6 hours later [(9.85±4.59)×106 copies, (7.81±3.43)×106 copies].Then 8 hours later the mtDNA began to slowly decreased.At these three time points, the mtDNA were all increased progressively than those at the other time points of the MSN group or at all time points of the control group (F=6.719, P＜0.05;F=11.181, P＜0.05).By immunoflourescence study, there were neutrophil extracellular traps (NETs) were formed 12 hours later in the MSU group and aggregated NETs were found 24 hours later.Conclusion In the inflammatory processes of acute peritonitis induced by MSU of in mice, with the expression of mtDNA increasing, the inflammation is relieved, and aggregated NETs are formed in the end.Expression of mtDNA may be one for the protective factors of the inflammation induced by MSU.

The relationship between mitochondrial DNA damage and retinal pigment epithelium cells / 天津医药

Mitochondrial DNA (mtDNA) is a genetic effect DNA molecule of double closed loop, and is crucial for cells and their functions. Mitochondria take an active part in physiological activities of retinal pigment epithelium (RPE) cells. The oxidative stress is usually occurred in RPE for its active metabolism, which can lead to mitochondria and mtDNA dam?age. Once mitochondria and mtDNA lesions have not been repaired timely, the lesions can be accumulated, which can cause dysfunctions and damaged-structures of RPE and mitochondria, and can motivate the progression of cell apoptosis. In the end it can result in some ocular related diseases such as aged-related macular degeneration (AMD). This study reviewed the functional relationship between mtDNA and RPE, and repair and detection methods of mtDNA damage.

Study on transfection of adeno associated virus 2-ND4 gene into mitochondria / 中华实验眼科杂志

Background Leber hereditary optic neuropathy (LHON) is mitochondrial DNA (mtDNA) disease and mainly leads to optical nerve degeneration.Its primary mechanism is synthesis disorder of DN4 protein due to variation of mtDNA 11778 locus.So to construct a vector with exogenous normal ND4 and transfect into mitochondria is a key of gene therapy for LHON.Objective This study was to investigate the in vitro transfection of adeno-associated virus (AAV)-ND4 gene into mitochondria.Methods Human renal epithelial cell lines transfected adenovirus E1A (293 cells) were regularly cultured and divided into two groups.Framework plasmids of recombinant AAV-ND4 or simple AAV2 were added to the cell medium respectively.The expression of ND4 in cells were located 12,24,36 and 48 hours after transfected by Y03 dual fluorescent quantum dots staining.The positive response for ND4 showed the green fluorescence.Results Cultured 293 cells grew well with 80％ confluence.Abundant green fluorescence particles were seen in cytoplasm in the AAV-ND4 transfected group,but only red fluorescence from mitochondrial protein was seen in the simple AAV transfected group under the fluorescence microscope.Conclusions Exogenous ND4 protein can been successfully transfected into mitochondria using the ND4 gene constructed AAV.This result provides experimental evidence for the further study on gene therapy of LHON.