Hearing Loss ; genetics ; Humans ; Mitochondria ; genetics ; Mutation

SIRT3, SIRT4 and SIRT5 are located in mitochondria and also known as mitochondrial sirtuins. They play important roles in regulating many cellular functions including cell survival, cell cycle or apoptosis, DNA repair and metabolism. Mitochondrial sirtuins are involved in the protection of mitochondrial integrity and energy metabolism under stress regulating the expression of neurotransmitter receptors, neurotrophins, extracellular matrix proteins and various transcription factors, thus involved in epileptogenesis triggered by both genetic or acquired factors. Here we review research progress on the actions of mitochondrial sirtuin in epilepsy; and discuss the challenges and perspectives of mitochondrial sirtuin as a potential therapeutic target for epilepsy.
Apoptosis ; Epilepsy/genetics* ; Humans ; Mitochondria/genetics* ; Sirtuin 3 ; Sirtuins

To evaluate the therapeutic effect of Potentilla discolor on 2,4,6-trinitrobenzensulfonic acid(TNBS)-induced experimental ulcerative colitis(UC) in rats and to determine its therapeutic mechanism through mitochondrial autophagy, immune cells, and cytokines. A rat model of UC was established by TNBS-ethanol enema. Rats were divided into six groups: control, UC model, sulfasalazine(positive drug), and high-dose, moderate-dose, and low-dose ethanol extract groups. After 14-day continuous administration of the corresponding drugs, the disease activity index(DAI) and hematoxylin and eosin(HE) were evaluated. The morphological structure of mitochondria was observed by using transmission electron microscope(TEM), mitophagy-related mRNA expression was detected by using Real-time quantitative polymerase chain reaction(qRT-PCR), immune cell differentiation in rat serum was detected by using flow cytometry(FCM), and cytokine expression in colon tissues of rats was detected by protein microarray. The results showed that compared with the model group, each dose group of P. discolor could significantly reduce the DAI of UC model rats, and decrease the degree of inflammatory cells infiltration in the colon tissue of UC model rats. Meanwhile the expressions of T cells and Th cells in the serum increased significantly, the expression of Tc cells in the serum decreased significantly. Transmission electron microscope found that there was fusion of mitochondria and lysosomes in the colon tissue of the administration group. The expressions of mitochondrial autophagy related genes NF-κB, p62 and parkin were significantly increased in colon tissues. The results of protein chip showed that compared with the model group, the high dose group of P. discolor could significantly regulate the expression of cytokines. In conclusion, these results suggested that P. discolor improved TNBS-induced acute ulcerative colitis in rats by regulating the mitochondrial autophagy and the inflammatory factor expression.
Animals ; Autophagy ; Colitis, Ulcerative/genetics* ; Colon ; Mitochondria ; Potentilla/genetics* ; Rats

Mitochondrial DNA (mtDNA) exhibits matrilineal inherence. Familial mitochondrial diseases caused by mtDNA mutations are generally involved in organs featuring high energy consumption, which include heart, brain and skeletal muscle. Recently, it has been found that some essential hypertension patients featured classical maternal inheritance, which has confirmed and enriched mtDNA mutations as one of the molecular mechanisms underlying maternally inherited hypertension. Nevertheless, more general as well as radical questions are still to be answered. This article reviews recent advance in mitochondrial genome evolution, mtDNA genetics and the role of mtDNA mutations in maternally inherited hypertension.
DNA, Mitochondrial ; genetics ; Evolution, Molecular ; Humans ; Hypertension ; genetics ; Mitochondria ; genetics ; Mutation

Erythrocytes ; metabolism ; Humans ; Kidney Diseases ; genetics ; metabolism ; Mitochondria ; genetics ; Mitochondrial Membranes ; metabolism ; Oxidative Stress ; genetics ; physiology

Humans ; Mitochondria/genetics* ; Mutation/genetics* ; Parkinson Disease/genetics* ; Protein Kinases ; Ubiquitin-Protein Ligases

Mitochondrion is known as the energy factory of the cell, which is also a unique mammalian organelle and considered to be evolved from aerobic prokaryotes more than a billion years ago. Mitochondrial DNA, similar to that of its bacterial ancestor’s, consists of a circular loop and contains significant number of unmethylated DNA as CpG islands. The innate immune system plays an important role in the mammalian immune response. Recent research has demonstrated that mitochondrial DNA (mtDNA) activates several innate immune pathways involving TLR9, NLRP3 and STING signaling, which contributes to the signaling platforms and results in effector responses. In addition to facilitating antibacterial immunity and regulating antiviral signaling, mounting evidence suggests that mtDNA contributes to inflammatory diseases following cellular damage and stress. Therefore, in addition to its well-appreciated roles in cellular metabolism and energy production,mtDNA appears to function as a key member in the innate immune system. Here, we highlight the emerging roles of mtDNA in innate immunity.
Animals ; DNA, Mitochondrial ; genetics ; Humans ; Immunity, Innate ; immunology ; Mitochondria ; genetics ; immunology ; Signal Transduction

As conserved enzymes with important functions, aminoacyl-tRNA synthetase are expressed ubiquitously in cells. These include cytoplasmic aminoacyl-tRNA synthetase, mitochondrial aminoacyl-tRNA synthetase and bifunctional aminoacyl-tRNA synthetase. Mitochondrial aminoacyl-tRNA synthetases catalyze the binding of amino acids with its corresponding tRNA in the mitochondria and participate in the translation of 13 subunits of oxidative phosphorylation enzyme complexes encoded by the mitochondrial genome. Mutations in genes encoding mitochondrial aminoacyl-tRNA synthase may cause a variety of genetic disorders. This review has summarized the clinical characteristics, molecular pathogenesis and treatment of genetic diseases caused by mutations of such genes.
Humans ; RNA, Transfer, Amino Acyl ; Genes, Mitochondrial ; Amino Acyl-tRNA Synthetases/genetics* ; Genome, Mitochondrial ; Mitochondria/genetics*

Objective: To investigate the association between peripheral blood mitochondrial DNA copy number (mtDNAcn) and incident risk of liver cancer. Methods: At the baseline of Dongfeng-Tongji (DFTJ) cohort, 27 009 retirees were recruited from Dongfeng Motor Corporation in 2008. After excluding people without baseline DNA, with current malignant tumor and loss of follow-up, 1 173 participants were randomly selected into a sub-cohort by age-and gender-stratified sampling method at a proportion of 5% among all retirees. A total of 154 incident liver cancer cases identified from the cohort before December 31, 2018 (4 cases had been selected into the sub-cohort) were selected to form the case cohort of liver cancer. For the above 1 323 participants, their baseline levels of mtDNAcn in peripheral blood cells were measured by using quantitative real-time PCR method. The restricted cubic spline analysis was used to fit the shape of the association between baseline mtDNAcn and incident risk of liver cancer. The weighted Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95%CI. Results: In this case-cohort study, the median follow-up time was 10.3 years. The restricted cubic spline analysis indicated that the relationship between peripheral blood mtDNAcn and incident risk of liver cancer followed a U-shaped pattern (P_non-linear<0.05). All case-cohort population were divided into four subgroups by sex-specific quartiles of mtDNAcn levels among sub-cohort participants, when compared to participants in the Q₂ subgroup of mtDNAcn, those in the Q₁ subgroup (HR=2.00,95%CI:1.08-3.70) and Q₄ subgroup (HR=4.11,95%CI:2.32-7.26) both had a significantly elevated risk of liver cancer, while those in the Q₃ subgroup (HR=1.05,95%CI:0.54-2.05) had not. There were no significant multiply interaction effects of aging, gender, tobacco smoking, alcohol drinking and history of chronic hepatitis on the above association (P_interaction>0.05). Conclusion: Both extremely low and high baseline level of mtDNAcn in peripheral blood cells are associated with an increased risk of incident liver cancer, but the underlying mechanisms need to be further clarified.
Cohort Studies ; DNA Copy Number Variations ; DNA, Mitochondrial/genetics* ; Female ; Humans ; Liver Neoplasms/genetics* ; Male ; Mitochondria

Mitochondrial DNA (mtDNA) mutations result in a variety of genetic diseases. As an emerging therapeutic method, mtDNA editing technology recognizes targets more based on the protein and less on the nucleic acid. Although the protein recognition type mtDNA editing technology represented by zinc finger nuclease technology, transcription activator like effector nuclease technology and base editing technology has made some progress, the disadvantages of complex recognition sequence design hinder further popularization. Gene editing based on nucleic acid recognition by the CRISPR system shows superiority due to the simple structure, easy design and modification. However, the lack of effective means to deliver nucleic acids into mitochondria limits application in the field of mtDNA editing. With the advances in the study of endogenous and exogenous import pathways and the deepening understanding of DNA repair mechanisms, growing evidence shows the feasibility of nucleic acid delivery and the broad application prospects of nucleic acid recognition type mtDNA editing technology. Based on the classification of recognition elements, this article summarizes the current principles and development of mitochondrial gene editing technology, and discusses its application prospects.
Genes, Mitochondrial ; Gene Editing ; Mitochondria/genetics* ; DNA, Mitochondrial/genetics* ; Nucleic Acids ; Technology