MT-ND1 Gene Research Articles

“Mitochondrial pathogenic mutations and metabolic alterations associated with COVID‐19 disease severity”

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) caused global pandemic and drastically affected the humankind. Mitochondrial mutations have been found to be associated with several respiratory diseases. Missense mutation and pathogenic mitochondrial variants might unveil the potential involvement of the mitochondrial genome in coronavirus disease 2019(COVID-19) pathogenesis. The present study aims to elucidate the role of mitochondrial DNA (mtDNA) mutations, mitochondrial haplogroup, and energy metabolism in disease severity. The study was performed on 58 subjects comprising COVID-19-positive (n = 42) and negative (n = 16) individuals. COVID-19-positive subjects were further categorized into severe deceased (SD), severe recovered (SR), moderate (Mo), and mild (Mi) patients, while COVID-19-negative subjects were healthy control (HC) for the study. High throughput next-generation sequencing was done to investigate mtDNA mutations and haplogroups. The computational approach was applied to study the effect of mtDNA mutations on protein secondary structure. Real time polymerase chain reactionwas used for mtDNA copy number determination and mitochondrial function parameters were also analyzed. We found 15 mtDNA mutations in MT-ND5, MT-ND4, MT-ND2, and MT-COI genes uniquely associated with COVID-19 severity affecting the secondary structure of proteins in COVID-19-positive subjects. Haplogroup analysis suggests that mtDNA haplogroups M3d1a and W3a1b might be potentially associated with COVID-19 pathophysiology. The mitochondrial function parameters were significantly altered in severe patients (SD and SR; p < 0.05). No significant relationship was found between mtDNA mutations and oxidative stress markers (p > 0.05). The study highlights the importance of mitochondrial reprogramming in COVID-19 patients and may provide a feasible approach towardfinding a path for therapeutic interventions to COVID-19 disease.

Mitochondrial Copies Number and Some Renal Function Biomarkers in Type 2 Diabetes Mellitus on Metformin

One of the most common metabolic illnesses in the world is diabetes mellitus. This metabolic disease is responsible for a large percentage of the burden of kidney damage and dysfunction. The goal of this study was to look into the renal function of diabetic patients using metformin monotherapy who came to Mosul's Al-Wafaa diabetes care and research facility. During the period 1 January 2021 to 30 April 2021, 47 patients with T2DM (age 50.48 7.74 years) were enrolled in this case-control study. These patients' results were compared to a control group of 47 seemingly healthy people (age 45.89 9.06 years). All participants' demographic and medical histories were acquired through the delivery of a questionnaire. Blood samples were collected and tested for the mt-ND1 gene, HbA1c, uric acid, urea, and creatinine, among other things. In diabetics, there were extremely significant increases in HbA1c, Urea, and Creatinine (p &lt; 0.001, 0.003, and 0.043, respectively) when compared to the control group. In diabetic patients, however, uric acid levels did not change significantly. HbA1c and uric acid had a strong negative connection (r = -0.045 and 0.05, respectively). In diabetic individuals, the number of mitochondrial copies was substantially lower than in the control group (p &lt; 0.001). In comparison to non-diabetic controls, diabetic patients treated with mono-metformin treatment had a lower mitochondrial copy number and moderate renal impairment.

Mitochondrial DNA haplogroup analysis in Saudi Arab patients with multiple sclerosis.

Previous studies have suggested that mitochondrial DNA (mtDNA) variants are associated with multiple sclerosis (MS), a complex neurodegenerative immune-mediated disease of the central nervous system. Since mtDNA is maternally inherited without recombination, specific mtDNA variants defining genetic background are associated with the susceptibility to human diseases. To assess the contribution of mtDNA haplogroups to the predisposition of MS in an Arab population, we analysed sequencing data of mitochondrial genomes from 47 native Saudi Arab individuals including 23 patients with relapsing-remitting MS (RRMS) and 24 healthy controls. All patients and controls could be classified into ten haplogroups. The European-specific haplogroup U was more prevalent in patients than in the controls (26.1% vs. 4.2%), whereas haplogroup T was only present in patients and haplogroups HV and N were only found in controls. Haplogroup U was significantly association with increased risk of MS (odds ratio = 6.26, p<0.05), although the association did not maintain significance after adjustment for multiple comparisons. Haplotype U was more prevalent in patients with younger age of onset (p = 0.006), but there was no relationship between haplotype U and disease severity, disease duration or EDSS and age-matched carriers and non-carriers of haplogroup U (p>0.05). Definition site of haplogroup U include the variant m.12308A>G in MT-TL2 gene which was found to affect highly conserved position within the variable arm of tRNALeu(CUN) and thus may impact mitochondrial protein synthesis, and two other variants namely m.11467A>G in MT-ND4 gene and m.12372G>A in MT-ND5 gene which were previously linked with mitochondrial function. Despite the small number of subjects, which may limit the statistical power of the study, our results showed for the first time a possible contribution of haplogroup U to the predisposition to MS in an Arab population. These findings warrant further validation in a large cohort to distinguish a genuine effect specific to MS from a chance finding due to small sampling.

A Patient Diagnosed with Mosaic Trisomy 18 Presenting New Symptoms: Diaphragmatic Relaxation and Cyclic Vomiting Syndrome. Updated Review of Mosaic Trisomy 18 Cases.

Although data on T18 are widespread, there is a lack of knowledge on mosaic trisomy 18 (mT18). A current review of mT18 symptomatology, long-term follow-up, and potential health risks is lacking for health care professionals. Our paper addresses these, emphasizing the importance of regular tumor screening as a key message for mT18 patient follow-up. We also present the case of a female patient with mT18 who presented with diaphragmatic relaxation and cyclic vomiting syndrome (CVS), which had previously not been reported in this genetic condition. On further investigating the etiology of CVS, we revealed a novel mitochondrial mutation in the MT-ND6 gene in heteroplasmic form. Based on the literature, we hypothesize that the mitochondrial mutation together with mT18 could result in CVS.

In Silico Evaluation of the Haplotype Diversity, Phylogenetic Variation and Population Structure of Human E. granulosus sensu stricto (G1 Genotype) Sequences.

Echinococcus granulosus sensu lato is the causative agent of cystic echinococcosis (CE), which is a neglected zoonotic disease with an important role in human morbidity. In this study, we aimed to investigate the haplotype diversity, genetic variation, population structure and phylogeny of human E. granulosus sensu stricto (s.s.) (G1 genotype) isolates submitted to GenBank from different parts of the world by sequencing the mitochondrial CO1 and ND1 genes. The sequences of the mt-CO1 (401 bp; n = 133) and mt-ND1 (407 bp; n = 140) genes were used to analyze the haplotype, polymorphism and phylogenetic of 273 E. granulosus s.s. (G1 genotype) isolates. Mutations were observed at 31 different points in the mt-CO1 gene sequences and at 100 different points in the mt-ND1 gene sequences. Furthermore, 34 haplotypes of the mt-CO1 sequences and 37 haplotypes of the mt-ND1 sequences were identified. Tajima's D, Fu's Fs, and Fu's LD values showed high negative values in both mt-CO1 and mt-ND1 gene fragments. The haplotype diversities in the sequences retrieved from GenBank in this study indicate that the genetic variation in human isolates of E. granulosus s.s. in western countries is higher than in eastern countries. This may be due to demographic expansions due to animal trades and natural selections.

Randomized trial of bilateral gene therapy injection for m.11778G > A MT-ND4 Leber optic neuropathy.

Leber hereditary optic neuropathy (LHON) is an important example of mitochondrial blindness with the m.11778G > A mutation in the MT-ND4 gene being the most common disease-causing mitochondrial DNA (mtDNA) variant worldwide. The REFLECT phase 3 pivotal study is a randomized, double-masked, placebo-controlled trial investigating the efficacy and safety of bilateral intravitreal injection of lenadogene nolparvovec in patients with a confirmed m.11778G > A mutation, using a recombinant adeno-associated virus vector 2, serotype 2 (rAAV2/2-ND4). The first-affected eye received gene therapy; the fellow (affected/not-yet-affected) eye was randomly injected with gene therapy or placebo. The primary endpoint was the difference in change from baseline of best-corrected visual acuity (BCVA) in second-affected/not-yet-affected eyes treated with lenadogene nolparvovec versus placebo at 1.5 years post-treatment, expressed in logarithm of the minimal angle of resolution (LogMAR). Forty-eight patients were treated bilaterally and 50 unilaterally. At 1.5 years, the change from baseline in BCVA was not statistically different between second-affected/not-yet-affected eyes receiving lenadogene nolparvovec and placebo (primary endpoint). A statistically significant improvement in BCVA was reported from baseline to 1.5 years in lenadogene nolparvovec-treated eyes: -0.23 LogMAR for the first-affected eyes of bilaterally treated patients (p < 0.01); and -0.15 LogMAR for second-affected/not-yet-affected eyes of bilaterally treated patients and the first-affected eyes of unilaterally treated patients (p < 0.05). The mean improvement in BCVA from nadir to 1.5 years was -0.38 (0.052) LogMAR and -0.33 (0.052) LogMAR in first-affected and second-affected/not-yet-affected eyes treated with lenadogene nolparvovec, respectively (bilateral treatment group). A mean improvement of -0.33 (0.051) LogMAR and -0.26 (0.051) LogMAR was observed in first-affected lenadogene nolparvovec-treated eyes and second-affected/not-yet-affected placebo-treated eyes, respectively (unilateral treatment group). The proportion of patients with one or both eyes on-chart at 1.5 years was 85.4% and 72.0% for bilaterally and unilaterally treated patients, respectively. The gene therapy was well tolerated, with no systemic issues. Intraocular inflammation, which was mostly mild and well controlled with topical corticosteroids, occurred in 70.7% of lenadogene nolparvovec-treated eyes versus 10.2% of placebo-treated eyes. Among eyes treated with lenadogene nolparvovec, there was no difference in the incidence of intraocular inflammation between bilaterally and unilaterally treated patients. Overall, the REFLECT trial demonstrated an improvement of BCVA in LHON eyes carrying the m.11778G > A mtDNA mutation treated with lenadogene nolparvovec or placebo to a degree not reported in natural history studies and supports an improved benefit/risk profile for bilateral injections of lenadogene nolparvovec relative to unilateral injections.

Enhanced mitochondrial DNA editing in mice using nuclear-exported TALE-linked deaminases and nucleases

We present two methods for enhancing the efficiency of mitochondrial DNA (mtDNA) editing in mice with DddA-derived cytosine base editors (DdCBEs). First, we fused DdCBEs to a nuclear export signal (DdCBE-NES) to avoid off-target C-to-T conversions in the nuclear genome and improve editing efficiency in mtDNA. Second, mtDNA-targeted TALENs (mitoTALENs) are co-injected into mouse embryos to cleave unedited mtDNA. We generated a mouse model with the m.G12918A mutation in the MT-ND5 gene, associated with mitochondrial genetic disorders in humans. The mutant mice show hunched appearances, damaged mitochondria in kidney and brown adipose tissues, and hippocampal atrophy, resulting in premature death.

FP.16 The effects of resistance exercise training on mitochondrial myopathy patients

Patients with single, large-scale mitochondrial DNA (mtDNA) deletions often present with mitochondrial myopathy (MM) for which no treatment is available. Exercise intervention induces beneficial effects in mitochondrial myopathy. However, the mechanisms for this are not yet understood. The aim of this study is to investigate genetic, biochemical and molecular changes triggered by 16-week resistance exercise training for the development of exercise mimetic drugs for the cure of MM patients. Quadriceps biopsies were taken from a cohort of single, large-scale mtDNA deletion patients before and after 16-week resistance exercise training. Biopsies were assessed for changes after exercise in oxidative phosphorylation (OXPHOS) staining for Laminin, VDAC1, Ndufb8 and COX1; fibre type distribution, size and contraction force staining for Myh7, Myh2 and Myh1; heteroplasmy using real-time PCR for MT-ND4, MT-CO1, MT-CO3 and MT-CYB genes; differentially expressed (DE) genes and related protein level using RNA-sequencing and imaging mass cytometry, respectively. Myopathy score is a strong predictor of resistance exercise training responsiveness. Compared to healthy controls, all patients present with a significantly lower contraction force of SKM fibres (p=0.003) and differential fibre type distribution with increased type 2a (p<0.04) and decreased fibre I (p<0.0001). After exercise, all cases show an increase in the proportion of fibres with higher level of COX1 (p<0.0012) and increase of Myh7⁺ fibre type size (all patients except P2, p < 0.0001). The majority of patients show a significant increase of mitochondrial mass that positively correlates with the increase of aerobic capability (R=0.81). Furthermore, 13,132 DE genes were identified between pre- and post-exercise cases, of which 40 DE genes were selected with p<0.05 and logarithmic fold change <1.5 or >1.5. Among these, 13 novel exercise-modulated targets were established with an increased protein level localising within the SKM fibres (e.g. Dock11, Edil3, Ikbkg, Gem). Further analysis will assess the protein level of targets with nuclear, perinuclear and extracellular localisation in SKM of MM patients. Resistance exercise training is effective in reducing the OXPHOS defects and induces SKM remodelling in MM patients. The identification of novel exercise-modulated targets may provide insight for the development of exercise mimetic drugs for the cure of mitochondrial myopathy patients.

Next-generation sequencing of Tunisian Leigh syndrome patients reveals novel variations: impact for diagnosis and treatment.

Mitochondrial cytopathies, among which the Leigh syndrome (LS), are caused by variants either in the mitochondrial or the nuclear genome, affecting the oxidative phosphorylation process. The aim of the present study consisted in defining the molecular diagnosis of a group of Tunisian patients with LS.Six children, belonging to five Tunisian families, with clinical and imaging presentations suggestive of LS were recruited. Whole mitochondrial DNA and targeted next-generation sequencing of a panel of 281 nuclear genes involved in mitochondrial physiology were performed. Bioinformatic analyses were achieved in order to identify deleterious variations.A single m.10197G>A (p.Ala47Thr) variant was found in the mitochondrial MT-ND3 gene in one patient, while the others were related to autosomal homozygous variants: two c.1412delA (p.Gln471ArgfsTer42) and c.1264A>G (p.Thr422Ala) in SLC19A3, one c.454C>G (p.Pro152Ala) in SLC25A19 and one c.122G>A (p.Gly41Asp) in ETHE1.Our findings demonstrate the usefulness of genomic investigations to improve LS diagnosis in consanguineous populations and further allow for treating the patients harboring variants in SLC19A3 and SLC25A19 that contribute to thiamine transport, by thiamine and biotin supplementation. Considering the Tunisian genetic background, the newly identified variants could be screened in patients with similar clinical presentation in related populations.

Retinal morphological and functional response to Idebenone therapy in Leber hereditary optic neuropathy.

Leber hereditary optic neuropathy (LHON) is a mitochondrial disease leading to optic atrophy due to degeneration of the retinal ganglion cell. A curative treatment is not available at the moment, but a new antioxidant drug, Idebenone, is expected to reduce the progression of the disorder. Two male patients, genetically confirmed with LHON, were clinically, morphologically, and electrophysiologically evaluated, before and three, six, nine and 12 months after starting the treatment. The patient with 3460G>A mutation in mitochondrially-encoded nicotinamide adenine dinucleotide, reduced form (NADH):ubiquinone oxidoreductase core subunit (mtND)1 gene showed an improvement in visual acuity, visual field, and visual evoked potentials with no effect on morphological examinations, while the patient with 11778G>A mutation in mtND4 gene showed no functional, nor morphological recovery after one year of treatment. This study demonstrates that Idebenone, depending on the genetic profile of the disease, may be effective in functional improvement in patients with LHON.

Mitochondrial DNA variant spectrum and the association with chronic tic disorders.

Tic disorders (TDs) are childhood onset neuropsychiatric disorders characterized by single or multiple sudden, rapid, recurrent, and motor tics and/or vocal tics. Several nuclear genes that are involved in mitochondrial functions suggest a potential role of mitochondria in TDs. To evaluate the association of mitochondrial DNA (mtDNA) variants with TDs, we screened the whole mitochondrial genomes in 493 TD patients and 109 age- and sex-matched healthy controls using next generation sequencing technology. A total of 1918 mtDNA variants including 1220 variants in patients only, 154 variants in controls only, and 544 variants shared by both cases and controls were identified. We found a higher number of overall mtDNA variants in TD patients (p= 0.00028). The variant density in MT-ATP6/8 and MT-CYB coding regions showed a significant difference between TD patients and controls (p= 0.0025 and p= 0.003, respectively). Furthermore, we observed a significant association of 15 common variants with TD based on an additive model, including m.14766C &gt; T, m.14783 T &gt; C, m.14905G &gt; A, and m.15301G &gt; A in MT-CYB; m.4769A &gt; G, m.10398A &gt; G, m.12705C &gt; T, and m.12850A &gt; G in MT-ND genes; m.7028C &gt; T in MT-CO1; m.8701A &gt; G in MT-ATP6; two variants with m.16223C &gt; T, m.5580 T &gt; C in noncoding regions; and three rRNA variants with m.1438A &gt; G and m.750A &gt; G in RNR1, and m.2352 T &gt; C in RNR2. Our data provide evidence of mtDNA variants associated with TDs. The accumulation of the heteroplasmic levels may increase the risk of TDs. Replication studies with larger samples are necessary to understand the pathogenesis of TDs.

Absence of lenadogene nolparvovec DNA in a brain tumor biopsy from a patient in the REVERSE clinical study, a case report

BackgroundLeber Hereditary Optic Neuropathy (LHON) is a rare, maternally-inherited mitochondrial disease that primarily affects retinal ganglion cells (RGCs) and their axons in the optic nerve, leading to irreversible, bilateral severe vision loss. Lenadogene nolparvovec gene therapy was developed as a treatment for patients with vision loss from LHON caused by the most prevalent m.11778G > A mitochondrial DNA point mutation in the MT-ND4 gene. Lenadogene nolparvovec is a replication-defective recombinant adeno-associated virus vector 2 serotype 2 (AAV2/2), encoding the human wild-type MT-ND4 protein. Lenadogene nolparvovec was administered by intravitreal injection (IVT) in LHON patients harboring the m.11778G > A ND4 mutation in a clinical development program including one phase 1/2 study (REVEAL), three phase 3 pivotal studies (REVERSE, RESCUE, REFLECT), and one long-term follow-up study (RESTORE, the follow-up of REVERSE and RESCUE patients).Case presentationA 67-year-old woman with MT-ND4 LHON, included in the REVERSE clinical study, received a unilateral IVT of lenadogene nolparvovec in the right eye and a sham injection in the left eye in May 2016, 11.4 months and 8.8 months after vision loss in her right and left eyes, respectively. The patient had a normal brain magnetic resonance imaging with contrast at the time of diagnosis of LHON. Two years after treatment administration, BCVA had improved in both eyes. The product was well tolerated with mild and resolutive anterior chamber inflammation in the treated eye. In May 2019, the patient was diagnosed with a right temporal lobe glioblastoma, IDH-wildtype, World Health Organization grade 4, based on histological analysis of a tumor excision. The brain tumor was assessed for the presence of vector DNA by using a sensitive validated qPCR assay targeting the ND4 sequence of the vector.ConclusionND4 DNA was not detected (below 15.625 copies/μg of genomic DNA) in DNA extracted from the brain tumor, while a housekeeping gene DNA was detected at high levels. Taken together, this data shows the absence of detection of lenadogene nolparvovec in a brain tumor (glioblastoma) of a treated patient in the REVERSE clinical trial 3 years after gene therapy administration, supporting the long-term favorable safety of lenadogene nolparvovec.

Generation of an induced pluripotent stem cell line from a patient with leber's hereditary optic neuropathy carrying a homoplasmic m.3635G > A mutation in the mitochondrial ND1 gene

Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disease that usually leads to selective degeneration of retinal ganglion cells (RGCs) and optic atrophy in young adults. One of three common mitochondrial DNA (mtDNA) mutations (m.11778G > A, m.3460G > A, m.14484 T > C) account for 90% of LHON cases. All three affect the function of respiration chain complex I. However, m.3635G > A, affecting the structure and function of MT-ND1 gene, is also associated with LHON. Here, we successfully generated a human induced pluripotent stem cell (hiPSC) line from an LHON patient carrying a homoplasmic m.3635G > A mutation in the MT-ND1 gene.

P-026 Lack of association between single polymorphic variants of the mitochondrial nicotinamide adenine dinucleotide dehydrogenase 3, and 4L (MT-ND3 and MT-ND4L) and male infertility

Abstract Study question Is there any association between male infertility and the polymorphic variants of Mitochondrial Nicotinamide Adenine Dinucleotide Hydride dehydrogenase (NADH) Subunit 3 and 4L (MT-ND3 and MT-ND4L)? Summary answer The genotypes and allele frequencies of the study population have shown a lack of statistically significant association between MT-ND3 and MT-ND4L SNPs and male infertility. What is known already Male infertility is a multifactorial condition associated with different genetic abnormalities in at least 15%–30% of cases. The rate of mutations in the mtDNA is high due to the lack of histones and DNA repair mechanisms. Moreover, mtDNA is more vulnerable compared to nuclear DNA due to the lack of an efficient repairing system and high exposure to oxidative species produced by the mitochondria. Eventually, this leads to abnormal sperm function, structure and even infertility. Study design, size, duration Prospective study was carried out between 2018 and 2019. 112 semen samples were collected in this study. Participants/materials, setting, methods The present study was carried out at the department of Obstetrics and Gynecology, University of Saarland,Germany. After semen analysis, samples were purified. Mitochondrial DNA was extracted using a QIAamp DNA Mini Kit, then, the mitochondrial DNA was amplified by using the REPLI-g Mitochondrial DNA Kit. Polymerase chain reaction (PCR) was used to amplify MT-ND3 and MT-ND4L genes. After that samples were purified and sequenced using the Sanger method in the Microsynth Seq Lab in Germany. Main results and the role of chance Eight single nucleotide polymorphisms (SNPs) in MT-ND3 (rs2853826, rs28435660, rs193302927, rs28358278, rs41467651, rs3899188, rs28358277 and rs28673954) and seven SNPs in MT-ND4L (rs28358280, rs28358281, rs28358279, rs2853487, rs2853488, rs193302933 and rs28532881) were detected and genotyped. The genotypes and allele frequencies of the study population have shown a lack of statistically significant association between MT-ND3 and MT-ND4L SNPs and male infertility. Besides, no statistically significant difference was found between the asthenozoospermia, oligozoospermia, teratozoospermia, asthenoteratozoospermia, oligoasthenoteratozoospermia and oligoteratozoospermia subgroups of subfertile males. However, rs28358278 genotype of the MT-ND3 gene was reported in the subfertile group but not in the fertile group, which implies a possible role of this SNP in male infertility. Limitations, reasons for caution The size number of the study samples. Wider implications of the findings Further studies are required to evaluate these findings. Moreover, the subfertile individuals who exhibit a polymorphism at rs28358278 require further monitoring and evaluation. Trial registration number Basic Science

Quantitative and structural characteristics of mitochondrial DNA in varicose veins

ObjectiveWe examined quantitative (in terms of mtDNA/nuclear DNA) and structural (in terms of common deletions in the MT-ND4 gene region) characteristics of mitochondrial DNA (mtDNA) in varicose veins (VVs) and venous wall layers by comparing mitochondrial genome parameters, as well as mitochondrial function (in terms of mitochondrial membrane potential (MtMP)), in varicose vein (VV) vs. non-varicose vein (NV) tissue samples. MethodsWe analyzed paired great saphenous vein samples (VV vs. NV segments from each patient left after venous surgery) harvested from patients with VVs. Relative mtDNA level and the proportion of no-deletion mtDNA were determined by a multiplex quantitative PCR (qPCR), confirming the latter with a more sensitive method – droplet digital PCR (ddPCR). Mitochondria's functional state in VVs was assessed using fluorescent (dependent on MtMP) live-staining of mitochondria in venous tissues. ResultsTotal mtDNA level was lower in VV than in NV samples (predominantly in the t. media layer). ddPCR analysis showed lower proportion of no-deletion mtDNA in VVs. Because of the decrease in relative MtMP in VVs, our results suggest a possible reduction of mitochondrial function in VVs. ConclusionQuantitative and structural changes (copy number and integrity) of mtDNA are plausibly involved in VV pathogenesis. Future clinical studies implementing the mitochondrial targeting may be eventually fostered after auxiliary mechanistic studies.

Tea Polyphenols Improve Down-Regulation of Mitochondrial Functional Gene Expression Induced by Bisphenol A in Zebrafish Ovaries

The plasticizer bisphenol A, a typical endocrine disrupting chemical, is widely present in the environment. Previous studies demonstrated that exposure to bisphenol A can cause reproductive toxicity, abnormal fertilization, and infertility. However, the mechanisms of low-concentration bisphenol A on the reproductive system and treatment measures have not been fully determined. In this study, we explored the transcriptomic profiles of female zebrafish ovaries. The transcriptomic data revealed that mitochondrial NADH dehydrogenase (mt-Nd) genes were significantly decreased in the bisphenol A-exposed group, while the co-administration of tea polyphenols remarkably elevated the expression of mt-Nd genes. To further explore the expression pattern of the mt-Nd, we analyzed the expression of six mt-Nd genes on different days by qRT-PCR in control, bisphenol A-exposed, and bisphenol A-tea polyphenols ovaries. Here, we found that 0.1 mg/L bisphenol A exposure adversely affects the mitochondrial respiratory chain in ovaries and may lead to reproductive disorders. Finally, our study demonstrated that tea polyphenols play a protective role in ovarian mitochondrial dysfunction in low-concentration bisphenol A-exposed female zebrafish.

The Analysis of Genetic Variation in the Mitochondrial ND6 Gene and its Application for the Identification of Indonesian Catfish Species

Background: Catfish is a freshwater and saltwater fish type with a wide distribution throughout the Indonesian archipelago. This study was conducted to analyze Indonesian catfish’s genetic diversity and evolutionary relationships based on the mitochondrial ND6 gene. Methods: Twenty-eight catfish samples were collected from nine rivers and one ocean in seven provinces of Indonesia. The MT-ND6 gene was amplified by using a set of primers (BaungND6F and BaungND6R). The MEGA X software was used to examine the MT-ND6 sequences for genetic variation and phylogenetic relation between Indonesian catfish populations. Result: There were 167 nucleotide site variations and thirty-two amino acid variations in the MT-ND6 gene. The genetic difference among populations ranges from 0.9 to 25% and the average evolutionary divergence in the overall populations was 14%, with catfish BB and PM having the closest genetic distance, while the farthest is BF to MP and BF to MS. In conclusion, the phylogenetic tree indicated that there were four distinct catfish clades in this study: MP, MS, KR, PM, BB and KS had been grouped with Hemibagrus nemurus (Bagridae family), EM had been grouped with Mystus vittatus (Bagridae family), BSBJ had been grouped with Pangasius pangasius (Pangasiidae family) and PD and BF had been grouped with Netuma thalassina (Ariidae family).

Next-generation sequencing of the whole mitochondrial genome identifies functionally deleterious mutations in patients with multiple sclerosis.

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system with genetics and environmental determinants. Studies focused on the neurogenetics of MS showed that mitochondrial DNA (mtDNA) mutations that can ultimately lead to mitochondrial dysfunction, alter brain energy metabolism and cause neurodegeneration. We analyzed the whole mitochondrial genome using next-generation sequencing (NGS) from 47 Saudi individuals, 23 patients with relapsing-remitting MS and 24 healthy controls to identify mtDNA disease-related mutations/variants. A large number of variants were detected in the D-loop and coding genes of mtDNA. While distinct unique variants were only present in patients or only occur in controls, a number of common variants were shared among the two groups. The prevalence of some common variants differed significantly between patients and controls, thus could be implicated in susceptibility to MS. Of the unique variants only present in the patients, 34 were missense mutations, located in different mtDNA-encoded genes. Seven of these mutations were not previously reported in MS, and predicted to be deleterious with considerable impacts on the functions and structures of encoded-proteins and may play a role in the pathogenesis of MS. These include two heteroplasmic mutations namely 10237T>C in MT-ND3 gene and 15884G>C in MT-CYB gene; and three homoplasmic mutations namely 9288A>G in MT-CO3 gene, 14484T>C in MT-ND6 gene, 15431G>A in MT-CYB gene, 8490T>C in MT-ATP8 gene and 5437C>T in MT-ND2 gene. Notably some patients harboured multiple mutations while other patients carried the same mutations. This study is the first to sequence the entire mitochondrial genome in MS patients in an Arab population. Our results expanded the mutational spectrum of mtDNA variants in MS and highlighted the efficiency of NGS in population-specific mtDNA variant discovery. Further investigations in a larger cohort are warranted to confirm the role of mtDNA MS.

M.3685T > C is a novel mitochondrial DNA variant that causes Leigh syndrome.

Variants in the mitochondrial genome can result in dysfunction of Complex I within the electron transport chain, thus causing disruptions in oxidative phosphorylation. Pathogenic variants in the MT-ND1 (NADH:ubiquinone oxidoreductase core subunit 1) gene that result in Complex I dysfunction are a known cause of Leigh syndrome. The patient is a 4-yr-old female who initially presented with generalized tonic–clonic seizures, with other symptoms of Leigh syndrome becoming apparent after the seizures. A three-generation pedigree revealed no family history of mitochondrial disorders. Laboratory studies were remarkable for elevated blood lactate, alanine, and GDF15. T2-weighted magnetic resonance imaging (MRI) revealed bilateral asymmetric signal hyperintensities in the basal ganglia, specifically in the bilateral putamen and right caudate. Magnetic resonance spectroscopy showed regionally elevated glucose and lactate. Mitochondrial respiratory chain enzyme analysis on skin fibroblasts demonstrated slightly reduced Complex I function. A 16-gene dystonia panel and chromosomal microarray analysis did not identify any disease-causing variants. Combined exome and mitochondrial genome sequencing identified the m.3685T > C (MT-ND1 p.Tyr127His) variant with 62.3% heteroplasmy with no alternative cause for the patient's condition. Mitochondrial genome sequencing of the mother demonstrated that the m.3685T > C variant occurred de novo. The m.3685T > C variant is absent from population databases. The tyrosine 127 residue is highly conserved, and several nearby pathogenic variants in the MT-ND1 gene have been previously associated with Leigh syndrome. We propose that the m.3685T > C variant is a novel mitochondrial DNA variant that causes Leigh syndrome, and we classify this variant as likely pathogenic based on currently available information.

Single-Cell Transcriptome Analysis of Chronic Antibody-Mediated Rejection After Renal Transplantation.

Renal transplantation is currently the most effective treatment for end-stage renal disease. However, chronic antibody-mediated rejection (cABMR) remains a serious obstacle for the long-term survival of patients with renal transplantation and a problem to be solved. At present, the role and mechanism underlying immune factors such as T- and B- cell subsets in cABMR after renal transplantation remain unclear. In this study, single-cell RNA sequencing (scRNA-seq) of peripheral blood monocytes (PBMCs) from cABMR and control subjects was performed to define the transcriptomic landscape at single-cell resolution. A comprehensive scRNA-seq analysis was performed. The results indicated that most cell types in the cABMR patients exhibited an intense interferon response and release of proinflammatory cytokines. In addition, we found that the expression of MT-ND6, CXCL8, NFKBIA, NFKBIZ, and other genes were up-regulated in T- and B-cells and these genes were associated with pro-inflammatory response and immune regulation. Western blot and qRT-PCR experiments also confirmed the up-regulated expression of these genes in cABMR. GO and KEGG enrichment analyses indicated that the overexpressed genes in T- and B-cells were mainly enriched in inflammatory pathways, including the TNF, IL-17, and Toll-like receptor signaling pathways. Additionally, MAPK and NF-κB signaling pathways were also involved in the occurrence and development of cABMR. This is consistent with the experimental results of Western blot. Trajectory analysis assembled the T-cell subsets into three differentiation paths with distinctive phenotypic and functional prog rams. CD8 effector T cells and γδ T cells showed three different differentiation trajectories, while CD8_MAI T cells and naive T cells primarily had two differentiation trajectories. Cell-cell interaction analysis revealed strong T/B cells and neutrophils activation in cABMR. Thus, the study offers new insight into pathogenesis and may have implications for the identification of novel therapeutic targets for cABMR.