Low-frequency maternal novel MYH7 mosaicism mutation in recurrent fetal-onset severe left ventricular noncompaction: a case report

BackgroundLeft ventricular noncompaction (LVNC) is a rare inherited cardiomyopathy with a broad phenotypic spectrum. The genotype-phenotype correlations in fetal-onset LVNC have not yet been fully elucidated. In this report, we present the first case of severe fetal-onset LVNC caused by maternal low-frequency somatic mosaicism of the novel myosin heavy chain 7 (MYH7) mutation.Case presentationA 35-year-old pregnant Japanese woman, gravida 4, para 2, with no significant medical or family history of genetic disorders, presented to our hospital. In her previous pregnancy at 33 years of age, she delivered a male neonate at 30 weeks of gestation with cardiogenic hydrops fetalis. Fetal echocardiography confirmed LVNC prenatally. The neonate died shortly after birth. In the current pregnancy, she again delivered a male neonate with cardiogenic hydrops fetalis caused by LVNC at 32 weeks of gestation. The neonate died shortly after birth. Genetic screening of cardiac disorder-related genes by next-generation sequencing (NGS) was performed which revealed a novel heterozygous missense MYH7 variant, NM_000257.3: c.2729A > T, p.Lys910Ile. After targeted and deep sequencing by NGS, the same MYH7 variant (NM_000257.3: c.2729A > T, p.Lys910Ile) was detected in 6% of the variant allele fraction in the maternal sequence but not in the paternal sequence. The MYH7 variant was not detected by conventional direct sequencing (Sanger sequencing) in either parent.ConclusionsThis case demonstrates that maternal low-frequency somatic mosaicism of an MYH7 mutation can cause fetal-onset severe LVNC in the offspring. To differentiate hereditary MYH7 mutations from de novo MYH7 mutations, parental targeted and deep sequencing by NGS should be considered in addition to Sanger sequencing

In vivo functional brain imaging and a therapeutic trial of L-argine in MELAS patients

Background: Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is the most common type of mitochondrial disease and is characterized by stroke-like episodes (SEs), myopathy, lactic acidosis, diabetes mellitus, hearing-loss and cardiomyopathy. The causal hypotheses for SEs in MELAS presented to date are angiopathy, cytopathy and neuronal hyperexcitability. L-arginine (Arg) has been applied for the therapy in MELAS patients.Scope of review: We will introduce novel in vivo functional brain imaging techniques such as MRI and PET, and discuss the pathogenesis of SEs in MELAS patients. We will further describe here our clinical experience with L-arg therapy and discuss the dual pharmaceutical effects of this drug on MELAS.Major conclusions: Administration of L-arg to MELAS patients has been successful in reducing neurological symptoms due to acute strokes and preventing recurrences of SEs in the chronic phase. L-Arg has dual pharmaceutical effects on both angiopathy and cytopathy in MELAS.General significance: In vivo functional brain imaging promotes a better understanding of the pathogenesis and potential therapies for MELAS patients. This article is part of a Special Issue entitled Biochemistry of Mitochondria, Life and Intervention 2010

Cu-ATSM is a novel indicator of intercellular over-reduced states in mitochondrial dysfunction: fundamental evaluation using mitochondrial DNA-less (Rho0) cells and cybrids carrying causal mitochondrial DNA mutation of MELAS syndrome

“Mitochondria, Life and Intervention 2010”　7th ASMRM ( Asian Society for Mitochondrial Research and Medicine ) an

The transcription factor FoxH1 (FAST) mediates Nodal signaling during anterior-posterior patterning and node formation in the mouse

FoxH1 (FAST) is a transcription factor that mediates signaling by transforming growth factor–β, Activin, and Nodal. The role of FoxH1 in development has now been investigated by the generation and analysis of FoxH1-deficient (FoxH1(−/−)) mice. The FoxH1(−/−) embryos showed various patterning defects that recapitulate most of the defects induced by the loss of Nodal signaling. A substantial proportion of FoxH1(−/−) embryos failed to orient the anterior-posterior (A-P) axis correctly, as do mice lacking Cripto, a coreceptor for Nodal. In less severely affected FoxH1(−/−) embryos, A-P polarity was established, but the primitive streak failed to elongate, resulting in the lack of a definitive node and its derivatives. Heterozygosity for nodal renders the FoxH1(−/−) phenotype more severe, indicative of a genetic interaction between FoxH1 and nodal. The expression of FoxH1 in the primitive endoderm rescued the A-P patterning defects, but not the midline defects, of FoxH1(−/−) mice. These results indicate that a Nodal-FoxH1 signaling pathway plays a central role in A-P patterning and node formation in the mouse

Cerebral Oxidative Stress in Early Alzheimer’s Disease Evaluated by ⁶⁴Cu-ATSM PET/MRI: A Preliminary Study

Oxidative stress imaging using diacetyl-bis (N4-methylthiosemicarbazone) (Cu-ATSM) was applied to the evaluation of patients with early Alzheimer’s disease (eAD). Ten eAD patients (72 ± 9 years) and 10 age-matched healthy controls (HCs) (73 ± 9 years) participated in this study. They underwent dynamic PET/MRI using 11C-PiB and 64Cu-ATSM with multiple MRI sequences. To evaluate cerebral oxidative stress, three parameters of 64Cu-ATSM PET were compared: standardized uptake value (SUV), tracer influx rate (Kin), and a rate constant k3. The input functions were estimated by the image-derived input function method. The relative differences were analyzed by statistical parametric mapping (SPM) using SUV and Kin images. All eAD patients had positive and HC subjects had negative PiB accumulation, and MMSE scores were significantly different between them. The 64Cu-ATSM accumulation tended to be higher in eAD than in HCs for both SUV and Kin. When comparing absolute values, eAD patients had a greater Kin in the posterior cingulate cortex and a greater k3 in the hippocampus compared with lobar cortical values of HCs. In SPM analysis, eAD had an increased left operculum and decreased bilateral hippocampus and anterior cingulate cortex compared to HCs. 64Cu-ATSM PET/MRI and tracer kinetic analysis elucidated cerebral oxidative stress in the eAD patients, particularly in the cingulate cortex and hippocampus

A novel application of radiolabeled Cu-ATSM as an indicator of intracellular over-reduced states in disorders with mitochondrial dysfunction: studies with cybrids carrying mitochondrial DNA mutation from MELAS patients.

Objectives: Radiolabeled Cu-diacetyl-bis (N4-methylthiosemicarbazone) (*Cu-ATSM), including 60/62/64Cu-ATSM, is a potential imaging agent of hypoxic tumors for PET. We have reported that *Cu-ATSM is trapped in tumor cells under intracellular over-reduced states eg. hypoxia. Here we evaluated *Cu-ATSM as an indicator of intercellular over-reduced states in disorders with mitochondrial dysfunction. Methods: Mitochondrial DNA-less &#61554;0 cells&#61472; and the parental 143B human osteosarcoma cells, and the cybrids carrying mutated mitochondria from patients of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) (2SD cells) and that carrying wild-type one (2SA) were used. Cells were treated under normoxia or hypoxia and 64Cu-ATSM uptake was examined to compare it with levels of biological reductant NADH and NADPH. Results: &#61554;0 206 cells showed 2.7-fold higher 64Cu-ATSM uptake than parent 143B cells under normoxia (P<0.05), whereas the 64Cu-ATSM uptake was not increased under hypoxia. The NADH and NADPH levels showed correlate change to 64Cu-ATSM uptake, but it was not increased under hypoxia. 2SD cells showed 1.5-fold increase in 64Cu-ATSM uptake under normoxia as compared with 2SA, whereas 2SD cells showed no significant increased 64Cu-ATSM uptake under hypoxia, which was correlated with NADH and NADPH levels.ISNM　2011　Annual Meetin

Radiolabeled Cu-ATSM as a novel indicator of overreduced intracellular state due to mitochondrial dysfunction: studies with mitochondrial DNA-less p0 cells and cybrids carrying MELAS mitochondrial DNA mutation

ObjectivesRadiolabeled Cu-diacetyl-bis (N4-methylthiosemicarbazone) (\u27Cu-ATSM), including 60/62/64Cu-ATSM, is a potential imaging agent of hypoxic tumors for positron emission tomography (PET). We have reported that \u27Cu-ATSM is trapped in tumor cells under intracellular overreduced states, e.g., hypoxia. Here we evaluated \u27Cu-ATSM as an indicator of intracellular overreduced states in mitochondrial disorders using cell lines with mitochondrial dysfunction.\nMethodsMitochondrial DNA-less p0206 cells; the parental 143B human osteosarcoma cells; the cybrids carrying mutated mitochondria from a patient of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) (2SD); and that carrying wild-type one (2SA) were used. Cells were treated under normoxia or hypoxia, and 64Cu-ATSM uptake was examined to compare it with levels of biological reductant NADH and NADPH.\nResultsp0206 cells showed higher 64Cu-ATSM uptake than control 143B cells under normoxia, whereas 64Cu-ATSM uptake was not significantly increased under hypoxia in p0206 cells. Additionally, 64Cu-ATSM uptake showed correlate change to the NADH and NADPH levels, but not oxygenic conditions. 2SD cells showed increased 64Cu-ATSM uptake under normoxia as compared with the control 2SA, and 64Cu-ATSM uptake followed NADH and NADPH levels, but not oxygenic conditions.\nConclusions64Cu-ATSM accumulated in cells with overreduced states due to mitochondrial dysfunction, even under normoxia. We recently reported that 62Cu-ATSM-PET can visualize stroke-like episodes maintaining oxygen supply in MELAS patients. Taken together, our data indicate that \u27Cu-ATSM uptake reflects overreduced intracellular states, despite oxygenic conditions; thus, \u27Cu-ATSM would be a promising marker of intracellular overreduced states for disorders with mitochondrial dysfunction, such as MELAS, Parkinson\u27s disease and Alzheimer\u27s disease.\nAbbreviations: Cu-ATSM, Cu-diacetyl-bis (N4-methylthiosemicarbazone); MELAS, mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes; mtDNA, mitochondrial DNA; PET, positron emission tomograph