PURPOSE: The disease entity mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is characterized by an early onset of stroke-like episodes. MELAS is the most dominant subtype of mitochondrial disease. Molecular genetic testing is important in the diagnosis of MELAS. The mitochondrial DNA (mtDNA) 3243A>G mutation is found in 80% of MELAS patients. Nevertheless, molecular analysis alone may be insufficient to diagnose MELAS because of mtDNA heteroplasmy. This study aimed to evaluate whether muscle biopsy is useful in MELAS patients as an initial diagnostic evaluation method. MATERIALS AND METHODS: The medical records of patients who were diagnosed with MELAS at the Department of Pediatrics of Gangnam Severance Hospital between January 2006 and January 2017 were reviewed. The study population included 12 patients. They were divided into two subgroups according to whether the results of muscle pathology were in accordance with mitochondrial diseases. Clinical variables, diagnostic evaluations, and clinical outcomes were compared between the two groups. RESULTS: Of the 12 patients, seven were muscle pathology-positive for mitochondrial disease. No statistically significant difference in clinical data was observed between the groups that were muscle pathology-positive and muscle pathology-negative for mtDNA 3243A>G mutation. Additionally, the patients with weakness as the initial symptom were all muscle pathology-positive. CONCLUSION: The usefulness of muscle biopsy appears to be limited to an initial confirmative diagnostic evaluation of MELAS. Muscle biopsy can provide some information in MELAS patients with weakness not confirmed by genetic testing.
Biopsy* ; Diagnosis ; DNA, Mitochondrial ; Genetic Testing ; Humans ; Medical Records ; MELAS Syndrome* ; Methods ; Mitochondrial Diseases ; Mitochondrial Encephalomyopathies* ; Molecular Biology ; Pathology ; Pediatrics

Objective To explore the effect of hydrogen sulfide on inflammatory factors and energy metabolism of mitochondria after limbs reperfusion injury in rats. Methods Sixty rats were divided into three groups:sham operation group,control group(ischemia-reperfusion injury + saline group),and experimental group(ischemia-reperfusion injury + HS group).Wistar rat models of limb ischemia-reperfusion injury were established.Skeletal muscle samples were collected to determine the levels of necrosis decomposition products [including myoglobin(MB),lipoprotein complex(LPC)and lipid peroxide(LPO)];blood samples were collected to determine the levels of interleukin(IL)-1,IL-6 and tumor necrosis factor-α(TNF-α);mitochondria were extracted for mitochondrial transmembrane potential measurement and ATP content detection.Statistical analysis was made on the test results. Results After ischemia reperfusion injury,the levels of MB,LPO,and LPC in skeletal muscle,liver,lung and renal tissues of the control group were significantly increased(MB:P =0.003,P =0.001,P =0.001,P =0.001;LPO:P =0.001,P =0.001,P =0.001,P =0.002;LPC:P =0.000,P =0.002,P =0.002,P =0.003),and hydrogen sulfide treatment during ischemia reperfusion significantly inhibited the production of MB,LPO,and LPC(MB:P =0.021,P =0.036,P =0.005;LPO:P =0.003,P =0.008,P =0.010,P =0.015;LPC:P =0.002,P =0.026,P =0.007,P =0.006).Ischemia/reperfusion of lower extremity in rats resulted in increased levels of IL-1,IL-6,and TNF-α in the serum of rats,and the levels of IL-1,IL-6,and TNF-increased over time,with statistically significant differences in IL-1,IL-6,and TNF-α among groups at 3 h(IL-1:P =0.019,P =0.011,P =0.009,$P_{12_{h}}$=0.008,and P =0.002;IL-6:P =0.026,P =0.009,P =0.002, $P_{12_{h}}$=0.002,P =0.003;TNF-α:P =0.002,P =0.002,P =0.005,$P_{12_{h}}$=0.002,P =0.003).The levels of IL-1,IL-6,and TNF-α in serum were significantly inhibited during ischemia reperfusion(IL-1:P =0.035,P =0.039,P =0.012,$P_{12_{h}}$=0.005,P =0.006;IL-6:P =0.042,P =0.025,P =0.023,$P_{12_{h}}$=0.006,P =0.005;TNF-α:P =0.005,P =0.003,P =0.022,$P_{12_{h}}$=0.005,P =0.005),and such inhibitory effects became even more obvious over time.After limb ischemia and reperfusion in the control group,the mitochondrial transmembrane potential of skeletal muscle cells significantly decreased compared with that of the sham group(t=6.698;P=0.001).After hydrogen sulfide treatment,the mitochondrial membrane potential energy of the experimental group was significantly higher than that of the control group(t=7.507,P = 0.000).The ATP level in the mitochondria of ischemia reperfusion rats in the control group was significantly lower than that in the sham group(t=7.526,P = 0.000).The content of mitochondrial ATP in the experimental group was significantly higher than that in the control group after hydrogen sulfide treatment(t=8.604,P = 0.000). Conclusions Hydrogen sulfide can alleviate the injury of skeletal muscle and distal organs after limb ischemia-reperfusion and reduce local inflammatory reaction.In addition,it is valuable in alleviating mitochondrial transmembrane potential and energy metabolism disorders during reperfusion injury.
Animals ; Energy Metabolism ; Hydrogen Sulfide ; pharmacology ; Inflammation ; metabolism ; Interleukin-6 ; metabolism ; Mitochondrial Diseases ; pathology ; Rats ; Rats, Wistar ; Reperfusion Injury ; Tumor Necrosis Factor-alpha ; metabolism

Alzheimer's Disease (AD) is a progressive neurodegenerative disease, which is pathologically defined by the accumulation of amyloid plaques and hyper-phosphorylated tau aggregates in the brain. Mitochondrial dysfunction is also a prominent feature in AD, and the extracellular Aβ and phosphorylated tau result in the impaired mitochondrial dynamics. In this study, we generated an induced pluripotent stem cell (iPSC) line from an AD patient with amyloid precursor protein (APP) mutation (Val715Met; APP-V715M) for the first time. We demonstrated that both extracellular and intracellular levels of Aβ were dramatically increased in the APP-V715M iPSC-derived neurons. Furthermore, the APP-V715M iPSC-derived neurons exhibited high expression levels of phosphorylated tau (AT8), which was also detected in the soma and neurites by immunocytochemistry. We next investigated mitochondrial dynamics in the iPSC-derived neurons using Mito-tracker, which showed a significant decrease of anterograde and retrograde velocity in the APP-V715M iPSC-derived neurons. We also found that as the Aβ and tau pathology accumulates, fusion-related protein Mfn1 was decreased, whereas fission-related protein DRP1 was increased in the APP-V715M iPSC-derived neurons, compared with the control group. Taken together, we established the first iPSC line derived from an AD patient carrying APP-V715M mutation and showed that this iPSC-derived neurons exhibited typical AD pathological features, including a distinct mitochondrial dysfunction.
Alzheimer Disease ; Amyloid ; Brain ; Carisoprodol ; Humans ; Immunohistochemistry ; Mitochondrial Dynamics ; Neurites ; Neurodegenerative Diseases ; Neurons ; Pathology ; Plaque, Amyloid ; Pluripotent Stem Cells

PURPOSE: Children with mitochondrial disease (MD) have clinical phenotypes that are more severe than those found in adults. In this study, we assessed cardiac function in children with MD using conventional and advanced echocardiographic measurements, explored any unique patterns present, and investigated the development of early cardiomyopathy (CMP). MATERIALS AND METHODS: We retrospectively reviewed the medical records of 33 children with MD. All patients underwent transthoracic echocardiography with conventional and advanced myocardial analysis. We compared all data between patients and an age-matched healthy control group. RESULTS: Conventional echocardiographic diastolic measurements of mitral E, E/A, and tissue Doppler E′ were significantly lower and E/E′ was significantly higher in children with MD, compared with the measurements from the control group. There was no significant difference in longitudinal and radial strain between the groups. Circumferential strain in the endocardium (p=0.161), middle myocardium (p=0.008), and epicardium (p=0.042) were lower in patients, compared to the values in controls. Circumferential strain was correlated with E′ (p < 0.01, r>0.60). CONCLUSION: In children with MD, myocardial circumferential strain may develop early in all three layers, even with normally preserved longitudinal and radial strain. This may be an early diagnostic indicator with which to predict CMP in this patient population.
Biomechanical Phenomena ; Child ; Echocardiography, Doppler ; Female ; Humans ; Male ; Mitochondrial Diseases/diagnostic imaging ; Mitochondrial Diseases/pathology ; Mitochondrial Diseases/physiopathology ; Myocardium/pathology

Taurine is an abundant, β-amino acid with diverse cytoprotective activity. In some species, taurine is an essential nutrient but in man it is considered a semi-essential nutrient, although cells lacking taurine show major pathology. These findings have spurred interest in the potential use of taurine as a therapeutic agent. The discovery that taurine is an effective therapy against congestive heart failure led to the study of taurine as a therapeutic agent against other disease conditions. Today, taurine has been approved for the treatment of congestive heart failure in Japan and shows promise in the treatment of several other diseases. The present review summarizes studies supporting a role of taurine in the treatment of diseases of muscle, the central nervous system, and the cardiovascular system. In addition, taurine is extremely effective in the treatment of the mitochondrial disease, mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), and offers a new approach for the treatment of metabolic diseases, such as diabetes, and inflammatory diseases, such as arthritis. The review also addresses the functions of taurine (regulation of antioxidation, energy metabolism, gene expression, ER stress, neuromodulation, quality control and calcium homeostasis) underlying these therapeutic actions.
Acidosis, Lactic ; Arthritis ; Brain Diseases ; Calcium ; Cardiovascular System ; Central Nervous System ; Cytoprotection ; Energy Metabolism ; Gene Expression ; Heart Failure ; Japan ; MELAS Syndrome ; Metabolic Diseases ; Mitochondrial Diseases ; Neurodegenerative Diseases ; Pathology ; Quality Control ; Taurine*

Alzheimer Disease ; complications ; pathology ; therapy ; Amyloid beta-Peptides ; metabolism ; Humans ; Mitochondria ; physiology ; Mitochondrial Diseases ; etiology ; tau Proteins ; metabolism

BACKGROUNDMitochondrial diseases are a group of energy metabolic disorders with multisystem involvements. Variable clinical features present a major challenge in pediatric diagnoses. We summarized the clinical spectrum of m.3243A>G mutation in Chinese pediatric patients, to define the common clinical manifestations and study the correlation between heteroplasmic degree of the mutation and clinical severity of the disease.

METHODSClinical data of one-hundred pediatric patients with symptomatic mitochondrial disease harboring m.3243A>G mutation from 2007 to 2013 were retrospectively reviewed. Detection of m.3243A>G mutation ratio was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism. Correlation between m.3243A>G mutation ratio and age was evaluated. The differences in clinical symptom frequency of patients with low, middle, and high levels of mutation ratio were analyzed by Chi-square test.

RESULTSSixty-six patients (66%) had suffered a delayed diagnosis for an average of 2 years. The most frequent symptoms were seizures (76%), short stature (73%), elevated plasma lactate (70%), abnormal magnetic resonance imaging/computed tomography (MRI/CT) changes (68%), vomiting (55%), decreased vision (52%), headache (50%), and muscle weakness (48%). The mutation ratio was correlated negatively with onset age (r = -0.470, P < 0.001). Myopathy was more frequent in patients with a high level of mutation ratio. However, patients with a low or middle level of m.3243A>G mutation ratio were more likely to suffer hearing loss, decreased vision, and gastrointestinal disturbance than patients with a high level of mutation ratio.

CONCLUSIONSOur study showed that half of Chinese pediatric patients with m.3243A>G mutation presented seizures, short stature, abnormal MRI/CT changes, elevated plasma lactate, vomiting, and headache. Pediatric patients with these recurrent symptoms should be considered for screening m.3243A>G mutation. Clinical manifestations and laboratory abnormalities should be carefully monitored in patients with this point mutation.

Adolescent ; Age of Onset ; Asian Continental Ancestry Group ; Chi-Square Distribution ; Child ; Child, Preschool ; DNA, Mitochondrial ; genetics ; Female ; Hearing Loss ; pathology ; physiopathology ; Humans ; Infant ; Lactic Acid ; blood ; Magnetic Resonance Imaging ; Male ; Mitochondrial Diseases ; blood ; genetics ; pathology ; physiopathology ; Mutation ; Point Mutation ; genetics ; Polymerase Chain Reaction ; Retrospective Studies ; Seizures ; pathology ; physiopathology

Mitochondria are important intracellular organelles that produce energy for cellular development, differentiation, and growth. Mitochondrial DNA (mtDNA) presents a 10- to 20-fold higher susceptibility to genetic mutations owing to the lack of introns and histone proteins. The mtDNA repair system is relatively inefficient, rendering it vulnerable to reactive oxygen species (ROS) produced during ATP synthesis within the mitochondria, which can then target the mtDNA. Under conditions of chronic inflammation and excess stress, increased ROS production can overwhelm the antioxidant system, resulting in mtDNA damage. This paper reviews recent literature describing the pathophysiological implications of oxidative stress, mitochondrial dysfunction, and mitochondrial genome aberrations in aging hematopoietic stem cells, bone marrow failure syndromes, hematological malignancies, solid organ cancers, chronic inflammatory diseases, and other diseases caused by exposure to environmental hazards.
DNA, Mitochondrial/*genetics/metabolism ; Hematologic Diseases/genetics/*pathology ; Humans ; *Inflammation ; Mitochondria/genetics ; Mutation ; Neoplasms/genetics/*pathology ; Oxidative Stress ; Reactive Oxygen Species/metabolism

INTRODUCTIONThis study aimed to assess the kind of haematological abnormalities that are present in patients with mitochondrial disorders (MIDs) and the frequency of their occurrence.

METHODSThe blood cell counts of a cohort of patients with syndromic and non-syndromic MIDs were retrospectively reviewed. MIDs were classified as 'definite', 'probable' or 'possible' according to clinical presentation, instrumental findings, immunohistological findings on muscle biopsy, biochemical abnormalities of the respiratory chain and/or the results of genetic studies. Patients who had medical conditions other than MID that account for the haematological abnormalities were excluded.

RESULTSA total of 46 patients ('definite' = 5; 'probable' = 9; 'possible' = 32) had haematological abnormalities attributable to MIDs. The most frequent haematological abnormality in patients with MIDs was anaemia. 27 patients had anaemia as their sole haematological problem. Anaemia was associated with thrombopenia (n = 4), thrombocytosis (n = 2), leucopenia (n = 2), and eosinophilia (n = 1). Anaemia was hypochromic and normocytic in 27 patients, hypochromic and microcytic in six patients, hyperchromic and macrocytic in two patients, and normochromic and microcytic in one patient. Among the 46 patients with a mitochondrial haematological abnormality, 78.3% had anaemia, 13.0% had thrombopenia, 8.7% had leucopenia and 8.7% had eosinophilia, alone or in combination with other haematological abnormalities.

CONCLUSIONMID should be considered if a patient's abnormal blood cell counts (particularly those associated with anaemia, thrombopenia, leucopenia or eosinophilia) cannot be explained by established causes. Abnormal blood cell counts may be the sole manifestation of MID or a collateral feature of a multisystem problem.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Anemia ; pathology ; Biopsy ; Blood Cell Count ; Electron Transport ; Eosinophilia ; blood ; Female ; Hematologic Diseases ; blood ; complications ; Humans ; Leukopenia ; blood ; Male ; Middle Aged ; Mitochondrial Diseases ; blood ; complications ; Muscles ; pathology ; Retrospective Studies ; Thrombocytopenia ; blood ; Thrombocytosis ; blood ; Young Adult

BACKGROUNDPreeclampsia is a multifactorial disease during pregnancy. Dysregulated lipid metabolism may be related to some preeclampsia. We investigated the relationship between triglycerides (TGs) and liver injury in different preeclampsia-like mouse models and their potential common pathways.

METHODSPreeclampsia-like models (Nw-nitro-L-arginine-methyl ester [L-NAME], lipopolysaccharide [LPS], apolipoprotein C-III [Apo] transgnic mice + L-NAME, β2 glycoprotein I [βGPI]) were used in four experimental groups: L-NAME (LN), LPS, Apo-LN and βGPI, respectively, and controls received saline (LN-C, LPS-C, Apo-C, βGPI-C). The first three models were established in preimplantation (PI), early-, mid- and late-gestation (EG, MG and LG). βGPI and controls were injected before implantation. Mean arterial pressure (MAP), 24-hour urine protein, placental and fetal weight, serum TGs, total cholesterol (TC) and pathologic liver and trophocyte changes were assessed.

RESULTSMAP and proteinuria were significantly increased in the experimental groups. Placenta and fetal weight in PI, EP and MP subgroups were significantly lower than LP. Serum TGs significantly increased in most groups but controls. TC was not different between experimental and control groups. Spotty hepatic cell necrosis was observed in PI, EG, MG in LN, Apo-LN and βGPI, but no morphologic changes were observed in the LPS group. Similar trophoblastic mitochondrial damage was observed in every experimental group.

CONCLUSIONSEarlier preeclampsia onset causes a higher MAP and urine protein level, and more severe placental and fetal damage. Preeclampsia-like models generated by varied means lead to different changes in lipid metabolism and associated with liver injury. Trophoblastic mitochondrial damage may be the common terminal pathway in different preeclampsia-like models.

Animals ; Cholesterol ; blood ; Disease Models, Animal ; Female ; Fetal Weight ; physiology ; Liver ; injuries ; Male ; Mice ; Mice, Inbred C57BL ; Mitochondrial Diseases ; blood ; pathology ; Placenta ; metabolism ; Pre-Eclampsia ; blood ; pathology ; Pregnancy ; Triglycerides ; blood ; Trophoblasts ; pathology