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Molecular Omics Mar 2022MELAS (mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes) is a progressive neurodegenerative disease caused by pathogenic mitochondrial DNA...
MELAS (mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes) is a progressive neurodegenerative disease caused by pathogenic mitochondrial DNA variants. The pathogenic mechanism of MELAS remains enigmatic due to the exceptional clinical heterogeneity and the obscure genotype-phenotype correlation among MELAS patients. To gain insights into the pathogenic signature of MELAS, we designed a comprehensive strategy integrating proteomics and metabolomics in patient-derived dermal fibroblasts harboring the ultra-rare MELAS pathogenic variant m.14453G>A, specifically affecting the mitochondrial respiratory complex I. Global proteomics was achieved by data-dependent acquisition (DDA) and verified by data-independent acquisition (DIA) using both Spectronaut and the recently launched MaxDIA platforms. Comprehensive metabolite coverage was achieved for both polar and nonpolar metabolites in both reverse phase and HILIC LC-MS/MS analyses. Our proof-of-principle MELAS study with multi-omics integration revealed OXPHOS dysregulation with a predominant deficiency of complex I subunits, as well as alterations in key bioenergetic pathways, glycolysis, tricarboxylic acid cycle, and fatty acid β-oxidation. The most clinically relevant discovery is the downregulation of the arginine biosynthesis pathway, likely due to blocked argininosuccinate synthase, which is congruent with the MELAS cardinal symptom of stroke-like episodes and its current treatment by arginine infusion. In conclusion, we demonstrated an integrated proteomic and metabolomic strategy for patient-derived fibroblasts, which has great clinical potential to discover therapeutic targets and design personalized interventions after validation with a larger patient cohort in the future.
Topics: Arginine; Chromatography, Liquid; Humans; MELAS Syndrome; Metabolomics; Neurodegenerative Diseases; Proteomics; Stroke; Tandem Mass Spectrometry
PubMed: 34982085
DOI: 10.1039/d1mo00416f -
Endocrinologia, Diabetes Y Nutricion Jun 2021MELAS syndrome (Mitochondrial Encephalopathy, Lactic Acidosis and Stroke-like episodes) is one of the most frequent mitochondrial pathologies. Its diagnosis is based on...
MELAS syndrome (Mitochondrial Encephalopathy, Lactic Acidosis and Stroke-like episodes) is one of the most frequent mitochondrial pathologies. Its diagnosis is based on the classic triad of symptoms its acronym stands for and the presence of ragged red fibres. There is currently no curative therapy for MELAS, and treatment focuses on managing complications that affect specific organs and functions. However, some immunonutrients can be used as a therapeutic alternative in patients with MELAS. We present a scientific literature review accompanied by the clinical case of a patient with dementia and seizures admitted to the intensive care unit.
PubMed: 34210633
DOI: 10.1016/j.endinu.2021.03.004 -
Brain : a Journal of Neurology Apr 2022In this retrospective, multicentre, observational cohort study, we sought to determine the clinical, radiological, EEG, genetics and neuropathological characteristics of... (Observational Study)
Observational Study
In this retrospective, multicentre, observational cohort study, we sought to determine the clinical, radiological, EEG, genetics and neuropathological characteristics of mitochondrial stroke-like episodes and to identify associated risk predictors. Between January 1998 and June 2018, we identified 111 patients with genetically determined mitochondrial disease who developed stroke-like episodes. Post-mortem cases of mitochondrial disease (n = 26) were identified from Newcastle Brain Tissue Resource. The primary outcome was to interrogate the clinico-radiopathological correlates and prognostic indicators of stroke-like episode in patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes syndrome (MELAS). The secondary objective was to develop a multivariable prediction model to forecast stroke-like episode risk. The most common genetic cause of stroke-like episodes was the m.3243A>G variant in MT-TL1 (n = 66), followed by recessive pathogenic POLG variants (n = 22), and 11 other rarer pathogenic mitochondrial DNA variants (n = 23). The age of first stroke-like episode was available for 105 patients [mean (SD) age: 31.8 (16.1)]; a total of 35 patients (32%) presented with their first stroke-like episode ≥40 years of age. The median interval (interquartile range) between first and second stroke-like episodes was 1.33 (2.86) years; 43% of patients developed recurrent stroke-like episodes within 12 months. Clinico-radiological, electrophysiological and neuropathological findings of stroke-like episodes were consistent with the hallmarks of medically refractory epilepsy. Patients with POLG-related stroke-like episodes demonstrated more fulminant disease trajectories than cases of m.3243A>G and other mitochondrial DNA pathogenic variants, in terms of the frequency of refractory status epilepticus, rapidity of progression and overall mortality. In multivariate analysis, baseline factors of body mass index, age-adjusted blood m.3243A>G heteroplasmy, sensorineural hearing loss and serum lactate were significantly associated with risk of stroke-like episodes in patients with the m.3243A>G variant. These factors informed the development of a prediction model to assess the risk of developing stroke-like episodes that demonstrated good overall discrimination (area under the curve = 0.87, 95% CI 0.82-0.93; c-statistic = 0.89). Significant radiological and pathological features of neurodegeneration were more evident in patients harbouring pathogenic mtDNA variants compared with POLG: brain atrophy on cranial MRI (90% versus 44%, P < 0.001) and reduced mean brain weight (SD) [1044 g (148) versus 1304 g (142), P = 0.005]. Our findings highlight the often idiosyncratic clinical, radiological and EEG characteristics of mitochondrial stroke-like episodes. Early recognition of seizures and aggressive instigation of treatment may help circumvent or slow neuronal loss and abate increasing disease burden. The risk-prediction model for the m.3243A>G variant can help inform more tailored genetic counselling and prognostication in routine clinical practice.
Topics: Adult; DNA, Mitochondrial; Humans; MELAS Syndrome; Mitochondrial Diseases; Mutation; Retrospective Studies; Stroke
PubMed: 34927673
DOI: 10.1093/brain/awab353 -
Balkan Medical Journal Jan 2024Coronavirus disease 2019 (COVID-19) is caused by the novel severe acute respiratory coronavirus-2 (SARS-CoV-2). Several explanations for the development of... (Review)
Review
Coronavirus disease 2019 (COVID-19) is caused by the novel severe acute respiratory coronavirus-2 (SARS-CoV-2). Several explanations for the development of cardiovascular complications during and after acute COVID-19 infection have been hypothesized. The COVID-19 pandemic, caused by SARS-CoV-2, has emerged as one of the deadliest pandemics in modern history. The myocardial injury in COVID-19 patients has been associated with coronary spasm, microthrombi formation, plaque rupture, hypoxic injury, or cytokine storm, which have the same pathophysiology as the three clinical variants of Kounis syndrome. The angiotensin-converting enzyme 2 (ACE2), reninaldosterone system (RAAS), and kinin-kallikrein system are the main proposed mechanisms contributing to cardiovascular complications with the COVID-19 infection. ACE receptors can be found in the heart, blood vessels, endothelium, lungs, intestines, testes, neurons, and other human body parts. SARS-CoV-2 directly invades the endothelial cells with ACE2 receptors and constitutes the main pathway through which the virus enters the endothelial cells. This causes angiotensin II accumulation downregulation of the ACE2 receptors, resulting in prothrombotic effects, such as hemostatic imbalance via activation of the coagulation cascade, impaired fibrinolysis, thrombin generation, vasoconstriction, endothelial and platelet activation, and pro-inflammatory cytokine release. The KKS system typically causes vasodilation and regulates tissue repair, inflammation, cell proliferation, and platelet aggregation, but SARS-CoV-2 infection impairs such counterbalancing effects. This cascade results in cardiac arrhythmias, cardiac arrest, cardiomyopathy, cytokine storm, heart failure, ischemic myocardial injuries, microvascular disease, Kounis syndrome, prolonged COVID, myocardial fibrosis, myocarditis, new-onset hypertension, pericarditis, postural orthostatic tachycardia syndrome, pulmonary hypertension, stroke, Takotsubo syndrome, venous thromboembolism, and thrombocytopenia. In this narrative review, we describe and elucidate when, where, and how COVID-19 affects the human cardiovascular system in various parts of the human body that are vulnerable in every patient category, including children and athletes.
Topics: Child; Humans; COVID-19; SARS-CoV-2; Renin-Angiotensin System; Angiotensin-Converting Enzyme 2; Peptidyl-Dipeptidase A; Cytokine Release Syndrome; Endothelial Cells; Pandemics; Kounis Syndrome; Cardiovascular System
PubMed: 38173173
DOI: 10.4274/balkanmedj.galenos.2023.2023-10-25 -
Brain and Nerve = Shinkei Kenkyu No... May 2023In MELAS, taurine modification defect in the anticodon of mitochondrial leucine tRNA causes codon translation failure. An investigator-started clinical trials of...
In MELAS, taurine modification defect in the anticodon of mitochondrial leucine tRNA causes codon translation failure. An investigator-started clinical trials of high-dose taurine therapy, that showed its efficacy in preventing stroke-like episodes, and improving the taurine modification rate. The drug was found to be safe. Taurine has been approved as a drug covered by public insurance for prevention of stroke-like episodes since 2019. Recently, L-arginine hydrochloride has also been approved for off-label use as a treatment for both acute and intermittent stages of stroke-like episodes.
Topics: Humans; MELAS Syndrome; Stroke; Arginine; Taurine; Mitochondria
PubMed: 37194524
DOI: 10.11477/mf.1416202371 -
Current Opinion in Clinical Nutrition... Jan 2020We would like to inform clinicians that the systematic administration of oral and intravenous L-arginine is therapeutically beneficial and clinically useful for patients... (Review)
Review
PURPOSE OF REVIEW
We would like to inform clinicians that the systematic administration of oral and intravenous L-arginine is therapeutically beneficial and clinically useful for patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), when they maintain plasma arginine concentration at least 168 μmol/l.
RECENT FINDINGS
MELAS is associated with endothelial dysfunction by decreased plasma L-arginine, nitric oxide (NO), and cyclic guanosine monophosphate. Endothelial dysfunction is also evident using flow-mediated vasodilation measurement by high-resolution Doppler echocardiography in the forearm artery in patients with MELAS. L-arginine is known to be an important precursor of NO to normalize the endothelial function in MELAS. In our clinical trial followed by 7 years follow-up study, the systematic administration of L-arginine to patients with MELAS significantly improved the survival curve of patients compared with natural history. Maintaining plasma arginine concentration at least 168 μmol/l may prevent the ictuses through the putative pathophysiologic mechanism and optimal normalization of endothelial dysfunction.
SUMMARY
Neither death nor bedriddenness occurred during the 2-year clinical trials, and the latter did not develop during the 7-year follow-up despite the progressively neurodegenerative and eventually life-threatening nature of MELAS. Therapeutic regimen of L-arginine on MELAS may be beneficial and clinically useful for patient care with MELAS.
Topics: Administration, Intravenous; Arginine; Clinical Trials as Topic; Follow-Up Studies; Humans; MELAS Syndrome; Treatment Outcome
PubMed: 31693521
DOI: 10.1097/MCO.0000000000000610 -
Annals of Medicine and Surgery (2012) Jun 2023Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like syndrome (MELAS) is a rare neurodegenerative inherited disorder that is characterized by stroke-like...
UNLABELLED
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like syndrome (MELAS) is a rare neurodegenerative inherited disorder that is characterized by stroke-like episodes, seizures, endocrine, and multiple system involvement. It is important to consider it as a differential diagnosis in a young patient with stroke-like episodes as it is progressive and has multiple complications.
CASE PRESENTATION
A 28-year-old male presented with slurring of speech and drowsiness for 7 h. He was a diagnosed case of type 2 diabetes mellitus, Wolf-Parkinson-White syndrome, and bilateral hearing loss.
CLINICAL FINDINGS AND INVESTIGATIONS
The patient had expressive aphasia with impaired fluency, repetition, and naming. After being discharged, he represented with loss of consciousness and involuntary movements of the whole body. MRI and MRS showed extension of hyperintense lesions to parieto-occipital regions from temporal regions not limited by vascular territories. MELAS was considered, which was confirmed by molecular genetic analysis. Coenzyme Q10 was used for MELAS. Insulin, Linagliptin, and levetiracetam were used for diabetes and seizures. Regular follow-up was advised to the patient.MELAS is an important syndrome to consider in any young patient presenting with unexplained stroke disorders. A high index of suspicion is needed in an appropriate clinical setting to avoid misdiagnosis.
PubMed: 37363571
DOI: 10.1097/MS9.0000000000000712 -
American Journal of Ophthalmology Case... Jun 2022Retro-mode illumination imaging can provide good visualization of chorio-retinal atrophy and of the retinal pigment epithelial alterations occurring in m.3243A > G...
Retro-mode illumination imaging can provide good visualization of chorio-retinal atrophy and of the retinal pigment epithelial alterations occurring in m.3243A > G associated retinopathy.
PubMed: 35282600
DOI: 10.1016/j.ajoc.2022.101411 -
Biology Sep 2022Advances in data acquisition via high resolution genomic, transcriptomic, proteomic and metabolomic platforms have driven the discovery of the underlying factors... (Review)
Review
Advances in data acquisition via high resolution genomic, transcriptomic, proteomic and metabolomic platforms have driven the discovery of the underlying factors associated with metabolic disorders (MD) and led to interventions that target the underlying genetic causes as well as lifestyle changes and dietary regulation. The review focuses on fourteen of the most widely studied inherited MD, which are familial hypercholesterolemia, Gaucher disease, Hunter syndrome, Krabbe disease, Maple syrup urine disease, Metachromatic leukodystrophy, Mitochondrial encephalopathy lactic acidosis stroke-like episodes (MELAS), Niemann-Pick disease, Phenylketonuria (PKU), Porphyria, Tay-Sachs disease, Wilson's disease, Familial hypertriglyceridemia (F-HTG) and Galactosemia based on genome wide association studies, epigenetic factors, transcript regulation, post-translational genetic modifications and biomarker discovery through metabolomic studies. We will delve into the current approaches being undertaken to analyze metadata using bioinformatic approaches and the emerging interventions using genome editing platforms as applied to animal models.
PubMed: 36138787
DOI: 10.3390/biology11091308 -
Survey of Ophthalmology 2021Cellular function and survival are critically dependent on the proper functionality of the mitochondrion. Neurodegenerative cellular processes including cellular... (Review)
Review
Cellular function and survival are critically dependent on the proper functionality of the mitochondrion. Neurodegenerative cellular processes including cellular adenosine triphosphate production, intermediary metabolism control, and apoptosis regulation are all mitochondrially mediated. The A to G transition at position 3243 in the mitochondrial MTTL1 gene that encodes for the leucine transfer RNA (m.3243A>G) causes a variety of diseases, including maternally inherited loss of hearing and diabetes syndrome (MIDD), mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes syndrome (MELAS). Ophthalmological findings-including posterior sub-capsular cataract, ptosis, external ophthalmoplegia, and pigmentary retinopathy- have all been associated with the m.3243A>G variant. Pigmentary retinopathy is, however, the most common ocular finding, occurring in 38% to 86% of cases. To date, little is known about the pathogenesis, natural history, and heteroplasmic and phenotypic correlations of m.3243A>G-associated pigmentary retinopathy. We summarize the current understanding of mitochondrial genetics and pathogenesis of some associated diseases. We then review the pathophysiology, histology, clinical features, treatment, and important ocular and systemic phenotypic manifestations of m.3243A>G variant associated retinopathy. Mitochondrial diseases require a multidisciplinary team approach to ensure effective treatment, regular follow-up, and accurate genetic counseling.
Topics: DNA, Mitochondrial; Humans; MELAS Syndrome; Mitochondria; Mitochondrial Diseases; Retinal Diseases
PubMed: 33610586
DOI: 10.1016/j.survophthal.2021.02.008