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Cureus Aug 2022Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a type of mitochondrial disease that is characterized by stroke-like seizures. For...
Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a type of mitochondrial disease that is characterized by stroke-like seizures. For these patients, serious, unexpected complications have occurred during and following anesthetic exposure. Provision of anesthesia is challenging, including the choice of anesthetic agents. We here report a case of general anesthesia management for a patient with MELAS. A 46-year-old woman was diagnosed with MELAS at the age of 40. She subsequently underwent cochlear implantation for hearing loss. Anesthesia was induced with midazolam and maintained with desflurane. In the present case, anesthesia was maintained with inhalation anesthetics to avoid the development of propofol infusion syndrome. Her intraoperative and postoperative courses were uneventful. The anesthesia management of patients with MELAS can be performed safely with carefully planned anesthesia and close monitoring at each step, including the postoperative period.
PubMed: 36106294
DOI: 10.7759/cureus.27761 -
Asian Journal of Surgery Mar 2023
Topics: Humans; MELAS Syndrome; Rhabdomyolysis; Growth Hormone
PubMed: 36068149
DOI: 10.1016/j.asjsur.2022.08.058 -
Orphanet Journal of Rare Diseases Sep 2022Genetic mitochondrial diseases represent a significant challenge to human health. These diseases are extraordinarily heterogeneous in clinical presentation and genetic... (Review)
Review
BACKGROUND
Genetic mitochondrial diseases represent a significant challenge to human health. These diseases are extraordinarily heterogeneous in clinical presentation and genetic origin, and often involve multi-system disease with severe progressive symptoms. Mitochondrial diseases represent the most common cause of inherited metabolic disorders and one of the most common causes of inherited neurologic diseases, yet no proven therapeutic strategies yet exist. The basic cell and molecular mechanisms underlying the pathogenesis of mitochondrial diseases have not been resolved, hampering efforts to develop therapeutic agents.
MAIN BODY
In recent pre-clinical work, we have shown that pharmacologic agents targeting the immune system can prevent disease in the Ndufs4(KO) model of Leigh syndrome, indicating that the immune system plays a causal role in the pathogenesis of at least this form of mitochondrial disease. Intriguingly, a number of case reports have indicated that immune-targeting therapeutics may be beneficial in the setting of genetic mitochondrial disease. Here, we summarize clinical and pre-clinical evidence suggesting a key role for the immune system in mediating the pathogenesis of at least some forms of genetic mitochondrial disease.
CONCLUSIONS
Significant clinical and pre-clinical evidence indicates a key role for the immune system as a significant in the pathogenesis of at least some forms of genetic mitochondrial disease.
Topics: Humans; Immune System; Leigh Disease; Mitochondria; Mitochondrial Diseases; Nervous System Diseases
PubMed: 36056365
DOI: 10.1186/s13023-022-02495-3 -
Frontiers in Neurology 2022Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and progressive external ophthalmoplegia (PEO) are established phenotypes of...
Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and progressive external ophthalmoplegia (PEO) are established phenotypes of mitochondrial disorders. They are maternally-inherited, multisystem disorder that is characterized by variable clinical, biochemical, and imaging features. We described the clinical and genetic features of a Chinese patient with late-onset MELAS/PEO overlap syndrome, which has rarely been reported. The patient was a 48-year-old woman who presented with recurrent ischemic strokes associated with characteristic brain imaging and bilateral ptosis. We assessed her clinical characteristics and performed mutation analyses. The main manifestations of the patient were stroke-like episodes and seizures. A laboratory examination revealed an increased level of plasma lactic acid and a brain MRI showed multiple lesions in the cortex. A muscle biopsy demonstrated ragged red fibers. Genetic analysis from a muscle sample identified two mutations: TL1 m.3243A>G and POLG c.3560C>T, with mutation loads of 83 and 43%, respectively. This suggested that mitochondrial disorders are associated with various clinical presentations and an overlap between the syndromes and whole exome sequencing is important, as patients may carry multiple mutations.
PubMed: 36034288
DOI: 10.3389/fneur.2022.927823 -
Cells Aug 2022Nearly half a century has passed since the discovery of cytoplasmic inheritance of human chloramphenicol resistance. The inheritance was then revealed to take place... (Review)
Review
Nearly half a century has passed since the discovery of cytoplasmic inheritance of human chloramphenicol resistance. The inheritance was then revealed to take place maternally by mitochondrial DNA (mtDNA). Later, a number of mutations in mtDNA were identified as a cause of severe inheritable metabolic diseases with neurological manifestation, and the impairment of mitochondrial functions has been probed in the pathogenesis of a wide range of illnesses including neurodegenerative diseases. Recently, a growing number of preclinical studies have revealed that animal behaviors are influenced by the impairment of mitochondrial functions and possibly by the loss of mitochondrial stress resilience. Indeed, as high as 54% of patients with one of the most common primary mitochondrial diseases, mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome, present psychiatric symptoms including cognitive impairment, mood disorder, anxiety, and psychosis. Mitochondria are multifunctional organelles which produce cellular energy and play a major role in other cellular functions including homeostasis, cellular signaling, and gene expression, among others. Mitochondrial functions are observed to be compromised and to become less resilient under continuous stress. Meanwhile, stress and inflammation have been linked to the activation of the tryptophan (Trp)-kynurenine (KYN) metabolic system, which observably contributes to the development of pathological conditions including neurological and psychiatric disorders. This review discusses the functions of mitochondria and the Trp-KYN system, the interaction of the Trp-KYN system with mitochondria, and the current understanding of the involvement of mitochondria and the Trp-KYN system in preclinical and clinical studies of major neurological and psychiatric diseases.
Topics: Animals; DNA, Mitochondrial; Humans; Kynurenine; Mitochondria; Mitochondrial Diseases; Tryptophan
PubMed: 36010683
DOI: 10.3390/cells11162607 -
Biomedicines Jul 2022(1) Background: The development of mitochondrial medicine has been severely impeded by a lack of effective therapies. (2) Methods: To better understand Mitochondrial...
Glutamate-Induced Deregulation of Krebs Cycle in Mitochondrial Encephalopathy Lactic Acidosis Syndrome Stroke-Like Episodes (MELAS) Syndrome Is Alleviated by Ketone Body Exposure.
(1) Background: The development of mitochondrial medicine has been severely impeded by a lack of effective therapies. (2) Methods: To better understand Mitochondrial Encephalopathy Lactic Acidosis Syndrome Stroke-like episodes (MELAS) syndrome, neuronal cybrid cells carrying different mutation loads of the m.3243A > G mitochondrial DNA variant were analysed using a multi-omic approach. (3) Results: Specific metabolomic signatures revealed that the glutamate pathway was significantly increased in MELAS cells with a direct correlation between glutamate concentration and the m.3243A > G heteroplasmy level. Transcriptomic analysis in mutant cells further revealed alterations in specific gene clusters, including those of the glutamate, gamma-aminobutyric acid pathways, and tricarboxylic acid (TCA) cycle. These results were supported by post-mortem brain tissue analysis from a MELAS patient, confirming the glutamate dysregulation. Exposure of MELAS cells to ketone bodies significantly reduced the glutamate level and improved mitochondrial functions, reducing the accumulation of several intermediate metabolites of the TCA cycle and alleviating the NADH-redox imbalance. (4) Conclusions: Thus, a multi-omic integrated approach to MELAS cells revealed glutamate as a promising disease biomarker, while also indicating that a ketogenic diet should be tested in MELAS patients.
PubMed: 35884972
DOI: 10.3390/biomedicines10071665 -
Asian Journal of Surgery Jan 2023
Topics: Humans; MELAS Syndrome; Growth Hormone; Stroke; DNA, Mitochondrial
PubMed: 35864039
DOI: 10.1016/j.asjsur.2022.07.035 -
Herzschrittmachertherapie &... Sep 2022MELAS syndrome is defined as a combination of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes resulting from mutations in mitochondrial...
MELAS syndrome is defined as a combination of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes resulting from mutations in mitochondrial DNA. All medical interventions in these patients appear challenging due to a high risk of lactate acidosis or anesthesiological complications. Of note, previous reports suggest that these patients have a higher incidence of Wolff-Parkinson-White (WPW) syndrome. Here, a case of successful catheter ablation of a posteroseptal bypass tract using analgosedation in a patient with MELAS syndrome combined with WPW syndrome is presented.
Topics: Catheter Ablation; Humans; MELAS Syndrome; Wolff-Parkinson-White Syndrome
PubMed: 35804205
DOI: 10.1007/s00399-022-00881-9 -
Stem Cell Research & Therapy Jun 2022Mitochondrial dysfunction and mitochondrial DNA (mtDNA) damage in the retinal pigment epithelium (RPE) have been implicated in the pathogenesis of age-related macular...
BACKGROUND
Mitochondrial dysfunction and mitochondrial DNA (mtDNA) damage in the retinal pigment epithelium (RPE) have been implicated in the pathogenesis of age-related macular degeneration (AMD). However, a deeper understanding is required to determine the contribution of mitochondrial dysfunction and impaired mitochondrial autophagy (mitophagy) to RPE damage and AMD pathobiology. In this study, we model the impact of a prototypical systemic mitochondrial defect, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), in RPE health and homeostasis as an in vitro model for impaired mitochondrial bioenergetics.
METHODS
We used induced pluripotent stem cells (iPSCs) derived from skin biopsies of MELAS patients (m.3243A > G tRNA leu mutation) with different levels of mtDNA heteroplasmy and differentiated them into RPE cells. Mitochondrial depletion of ARPE-19 cells (p cells) was also performed using 50 ng/mL ethidium bromide (EtBr) and 50 mg/ml uridine. Cell fusion of the human platelets with the p cells performed using polyethylene glycol (PEG)/suspension essential medium (SMEM) mixture to generate platelet/RPE "cybrids." Confocal microscopy, FLowSight Imaging cytometry, and Seahorse XF Mito Stress test were used to analyze mitochondrial function. Western Blotting was used to analyze expression of autophagy and mitophagy proteins.
RESULTS
We found that MELAS iPSC-derived RPE cells exhibited key characteristics of native RPE. We observed heteroplasmy-dependent impairment of mitochondrial bioenergetics and reliance on glycolysis for generating energy in the MELAS iPSC-derived RPE. The degree of heteroplasmy was directly associated with increased activation of signal transducer and activator of transcription 3 (STAT3), reduced adenosine monophosphate-activated protein kinase α (AMPKα) activation, and decreased autophagic activity. In addition, impaired autophagy was associated with aberrant lysosomal function, and failure of mitochondrial recycling. The mitochondria-depleted p cells replicated the effects on autophagy impairment and aberrant STAT3/AMPKα signaling and showed reduced mitochondrial respiration, demonstrating phenotypic similarities between p and MELAS iPSC-derived RPE cells.
CONCLUSIONS
Our studies demonstrate that the MELAS iPSC-derived disease models are powerful tools for dissecting the molecular mechanisms by which mitochondrial DNA alterations influence RPE function in aging and macular degeneration, and for testing novel therapeutics in patients harboring the MELAS genotype.
Topics: Autophagy; DNA, Mitochondrial; Energy Metabolism; Epithelial Cells; Humans; Induced Pluripotent Stem Cells; MELAS Syndrome; Macular Degeneration; Mitochondria; Retinal Pigment Epithelium; Retinal Pigments
PubMed: 35715869
DOI: 10.1186/s13287-022-02937-6 -
Molecular Neurobiology Sep 2022Monogenic forms of cerebral small vessel disease (CSVD) can be caused by both variants in nuclear DNA and mitochondrial DNA (mtDNA). Mitochondrial encephalopathy, lactic...
Monogenic forms of cerebral small vessel disease (CSVD) can be caused by both variants in nuclear DNA and mitochondrial DNA (mtDNA). Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is known to have a phenotype similar to Cerebral Autosomal Dominant Arteriopathy with Sub-cortical Infarcts and Leukoencephalopathy (CADASIL), and can be caused by variants in the mitochondrial genome and in several nuclear-encoded mitochondrial protein (NEMP) genes. The aim of this study was to screen for variants in the mitochondrial genome and NEMP genes in a NOTCH3-negative CADASIL cohort, to identify a potential link between mitochondrial dysfunction and CSVD pathology. Whole exome sequencing was performed for 50 patients with CADASIL-like symptomology on the Ion Torrent system. Mitochondrial sequencing was performed using an in-house designed protocol with sequencing run on the Ion GeneStudio S5 Plus (S5 +). NEMP genes and mitochondrial sequencing data were examined for rare (MAF < 0.001), non-synonymous variants that were predicted to have a deleterious effect on the protein. We identified 29 candidate NEMP variants that had links to either MELAS-, encephalopathy-, or Alzheimer's disease-related phenotypes. Based on these changes, variants affecting POLG, MTO1, LONP1, NDUFAF6, NDUFB3, and TCIRG1 were thought to play a potential role in CSVD pathology in this cohort. Overall, the exploration of the mitochondrial genome identified a potential role for mitochondrial related proteins and mtDNA variants contributing to CSVD pathologies.
Topics: ATP-Dependent Proteases; CADASIL; Cerebral Small Vessel Diseases; DNA, Mitochondrial; Humans; Leukoencephalopathies; MELAS Syndrome; Mitochondria; Mitochondrial Proteins; Mutation; Stroke; Vacuolar Proton-Translocating ATPases
PubMed: 35699875
DOI: 10.1007/s12035-022-02914-3