Top PDF Mitochondrial Energy-Deficient Endophenotype in Autism

Mitochondrial Energy-Deficient Endophenotype in Autism

Mitochondrial Energy-Deficient Endophenotype in Autism

15q inverted duplication with autism and mitochondrial dysfunction: Chromosomal rearrangements have proven to be critical landmarks in the development of our understanding of genetic disease. Particularly propitious for the discovery of disease mechanism is the paradigm that arises when a characteristic chromosomal rearrangement is recognized in a rare subset of individuals with the disease, as the rearrangement often disrupts the function of a critical gene in the pathway leading to the disease. An important step towards highlighting an energy- deficient endophenotype of autism arose in this context. Our University California, Irvine (UCI) autism center reported that two unrelated children rigorously defined to have autism --- by Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV), Autism Diagnostic Observation Schedule-Generic (ADOS-G) and Autism Diagnostic Interview- Revised (ADI-R)--- in whom we had identified a panel of biochemical signs of mild mitochondrial dysfunction including a secondary carnitine deficiency, also both had an inverted duplication of chromosome 15q11-q13 [39] . Both had uneventful perinatal courses, moderate motor delay, severe hypotonia, periods of moderate to severe lethargy (particularly during an intercurrent illness), elevated urinary lactic acid, elevated serum alanine, lactate and pyruvate and normal electroencephalograms (EEG) and magnetic resonance imaging (MRI) scans. The first child’s mitochondrial enzyme assay on muscle showed partial deficiency of respiratory complex III with pronounced mitochondrial hyper-proliferation. The second child’s muscle biopsy showed only mitochondrial hyper-proliferation. Assay of the mitochondrial enzymes in skin fibroblasts from both children showed hyper-proliferation and a relative complex III deficiency. Mitochondrial hyper- proliferation reflects a subtle defect in mitochondrial energy production to which the organelles themselves respond by added rounds of division, increasing the number of mitochondria per cell. Karyotype analysis revealed that each patient carried an extra marker chromosome and detailed fluorescent in situ hybridization (FISH) studies revealed that the marker chromosome in both of these patients contains a duplicated segment from the 15q11 – 13 chromosomal region that is at least 22,810Kb in length. Presumably
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Deficient induction response in a Xenopus nucleocytoplasmic hybrid.

Deficient induction response in a Xenopus nucleocytoplasmic hybrid.

Incompatibilities between the nucleus and the cytoplasm of sufficiently distant species result in developmental arrest of hybrid and nucleocytoplasmic hybrid (cybrid) embryos. Several hypotheses have been proposed to explain their lethality, including problems in embryonic genome activation (EGA) and/or nucleo-mitochondrial interactions. However, conclusive identification of the causes underlying developmental defects of cybrid embryos is still lacking. We show here that while over 80% of both Xenopus laevis and Xenopus (Silurana) tropicalis same-species androgenetic haploids develop to the swimming tadpole stage, the androgenetic cybrids formed by the combination of X. laevis egg cytoplasm and X. tropicalis sperm nucleus invariably fail to gastrulate properly and never reach the swimming tadpole stage. In spite of this arrest, these cybrids show quantitatively normal EGA and energy levels at the stage where their initial gastrulation defects are manifested. The nucleocytoplasmic incompatibility between these two species instead results from a combination of factors, including a reduced emission of induction signal from the vegetal half, a decreased sensitivity of animal cells to induction signals, and differences in a key embryonic protein (Xbra) concentration between the two species, together leading to inefficient induction and defective convergence-extension during gastrulation. Indeed, increased exposure to induction signals and/or Xbra signalling partially rescues the induction response in animal explants and whole cybrid embryos. Altogether, our study demonstrates that the egg cytoplasm of one species may not support the development promoted by the nucleus of another species, even if this nucleus does not interfere with the cytoplasmic/maternal functions of the egg, while the egg cytoplasm is also capable of activating the genome of that nucleus. Instead, our results provide evidence that inefficient signalling and differences in the concentrations of key proteins between species lead to developmental defects in cybrids. Finally, they show that the incompatibilities of cybrids can be corrected by appropriate treatments.
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Metformin reduces hepatic expression of SIRT3, the mitochondrial deacetylase controlling energy metabolism.

Metformin reduces hepatic expression of SIRT3, the mitochondrial deacetylase controlling energy metabolism.

ERRa is a nuclear receptor induced by fasting [25], and controls transcription of Sirt3 gene [14]. Consistently with these observations, ERRa levels were elevated in cells treated with glucagon and cAMP (Fig. 2a, b). On the other hand, metformin attenuated induction of ERRa mRNA by glucagon (Fig. 2c). Moreover, treatment of primary hepatocytes with metformin alone reduced ERRa (Fig. 2d). To further study the significance of ERRa reduction, the expression of two established ERRa target genes, Ppara [26] and Cyp17a1 [27], was measured. Indeed, PPARa and CYP17A1 mRNAs were downregulated by metfor- min; however, both genes, as well as SIRT3, were affected by lower concentrations of metformin than ERRa (Fig. 2d, Fig. 1d). In the next phase, we performed an in vivo experiment. Mice were treated with metformin (300 mg/kg i.g. once a day) for seven days and hepatic mRNA expression was compared to vehicle- treated controls (physiological saline). A relatively high dose of metformin was used because of earlier reports suggesting that high doses of i.g. metformin are necessary in rodents to reach plasma concentrations similar to those found in patients [28] and also because a similar dose was used in a previous study to demonstrate metformin’s effect on blood glucose in AMPK-deficient mice [3]. ERRa, SIRT3 and PPARa mRNAs were all statistically significantly downregulated by metformin (Fig. 2e). The contri- bution of ERRa reduction to SIRT3 downregulation by metformin was further studied by knockdown of ERRa in primary hepatocytes. ERRa siRNA did not affect constitutive expression of SIRT3. In contrast, PGC-1a-mediated induction of SIRT3 was significantly attenuated by ERRa knockdown (Fig. 2f).
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Genetic Evidence for Elevated Pathogenicity of Mitochondrial DNA Heteroplasmy in Autism Spectrum Disorder.

Genetic Evidence for Elevated Pathogenicity of Mitochondrial DNA Heteroplasmy in Autism Spectrum Disorder.

Although ASD is traditionally described as a developmental disorder of the central nervous system, emerging evidence suggests that systemic physiological abnormalities, including dysre- gulated inflammation and immune system [6,7], elevated oxidative stress [8], and mitochon- drial dysfunction [9–12], are present in peripheral tissues as well as in brains of autistic patients [13]. Epidemiological studies also identified a staggeringly high comorbidity between ASD and mitochondrial disorder (MD) [14]. MD is a heterogeneous group of diseases due to maternally inherited or sporadic defects in genes encoding the mitochondrial oxidative phos- phorylation (OXPHOS) system [15], the core functional component of mitochondria responsi- ble for generating energy. MD usually results from genetic mutations on nuclear DNA or mitochondrial DNA (mtDNA) genes [15]. It has an extremely low birth prevalence of 6.2 in 100,000 children [16] and only about 1 in 4,300 adults is affected or at risk of developing MD [17]. However, the incidence of MD among autistic patients is estimated up to 5% by some studies [14], over 200-fold the incidence of MD in general populations. In addition, expression of OXPHOS genes has been shown to decrease in brains of autistic patients [18], suggesting a biological overlap in the pathogenesis of MD and ASD. Moreover, decreased activity of the five OXPHOS complexes has been observed in leukocytes, buccal cells, muscle biopsies and brains of autistic patients [11,14,19], suggesting the increased MD incidence among autistic patients is due not to a specific protein defect but to defects across components of the OXPHOS system.
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Mitochondrial disease in autism spectrum disorder patients: a cohort analysis.

Mitochondrial disease in autism spectrum disorder patients: a cohort analysis.

Twenty-three of the 25 children underwent quadriceps muscle biopsies, 11 had skin biopsies, and one had a liver biopsy. Three patients had sibs with muscle biopsies. Muscle ETC determina- tions were performed at either Horizon Molecular Medicine, LLC, Atlanta [20,21] or the Center for Inherited Disorders of Energy Metabolism (CIDEM) Lab, Cleveland [22]. Muscle biopsy specimens were either snap frozen then shipped for ETC determination in homogenates or muscle mitochondria were isolated from fresh muscle biopsy specimens with aliquots frozen for subsequent determination of ETC activities. Functional (polarographic) analyses of oxidative phosphorylation using freshly isolated muscle mitochondria were performed at CIDEM [22]. ETC determinations of skin fibroblasts were done at CIDEM [23] or Mayo Laboratories. Fibroblast lactate and pyruvate measure- ments were performed at The Hospital for Sick Children, Toronto [24]. ETC activities were normalized to the mitochondrial marker enzyme citrate synthase, or if citrate synthase activity was not assayed, the percent of the mean of controls was used.
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The biopsychosocial processes in autism spectrum disorder

The biopsychosocial processes in autism spectrum disorder

The results of Schultz et al. [27] regarding the poor acti- vation of the fusiform gyrus may support the theory of weak central coherence suggesting that, in individuals with autism, processing the stimulus of sight of a face occurs so that attention is paid to details, consistent with the pro- cessing of non-facial stimuli, such as objects - elements that depend on specific characteristics for identification, rather than a configurational focus, the set of elements which we call a face [30].

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CoDAS  vol.26 número3

CoDAS vol.26 número3

criminate, by identifying the behavior of children, speciic developmental disorders, such as autism, Rett syndrome (RS), Asperger syndrome (AS), pervasive developmental disorders not otherwise speciied (PDD-NOS), apraxia, mental retarda- tion (MR), and other syndromes (OS). The last three catego- ries will not be approached in this study because they are not

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Rev. Bras. Psiquiatr.  vol.28 número2

Rev. Bras. Psiquiatr. vol.28 número2

The multifactorial threshold model of complex genetic disease assumes that many factors contribute to a disorder in an indivi- dual, that the effects of each single factor may be small but small effects may accumulate, and that once the combined effects of the factors pass some critical value the disorder may become manifest. 3 This model also can be applied to both macro

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Altered hematopoiesis in mice lacking DNA polymerase mu is due to inefficient double-strand break repair.

Altered hematopoiesis in mice lacking DNA polymerase mu is due to inefficient double-strand break repair.

The role of DNA repair in hematopoietic homeostasis has become increasingly clear in recent years [20–23]. Knockout models of many DNA repair enzymes are characterized by either reduced stem cell function or alterations in specific hematopoietic populations. Moreover, since stem cells are protected from apoptosis [20,21], probably because of their quiescent state [46], deficiency in DNA repair enzymes allows mutations to accumulate in these cells. Conversely, more committed progenitors, which cycle more rapidly, would be more sensitive to cell cycle arrest or apoptosis, thus explaining the observed reduction in the numbers of progenitor cells in Polm-deficient mice. Thus the survival of HSC comes at the price of accumulated mutations; two recent reports show that mice deficient in DNA repair maintain expanded stem cell pools, but that these pools have a reduced differentiation potential during aging [20,21].
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Comparação dos instrumentos Childhood Autism Rating Scale e Autism Behavior Checklist na identificação e caracterização de indivíduos com distúrbios do espectro autístico.

Comparação dos instrumentos Childhood Autism Rating Scale e Autism Behavior Checklist na identificação e caracterização de indivíduos com distúrbios do espectro autístico.

5. Pereira AM, Wagner MB, Riesgo RS. Autismo infantil: Tradução e validação da CARS (Childhood Autism Rating Scale) para uso no Brasil [tese]. Porto Alegre: Universidade Federal do Rio Grande do Sul; 2007. 6. Stella J, Mundy P, Tuchman, R. Social and nonsocial factors in the

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The functionality profile of children with Autistic Spectrum Disorders (ASD) in the Azores – communication, learning and autonomy

The functionality profile of children with Autistic Spectrum Disorders (ASD) in the Azores – communication, learning and autonomy

encourage parents to accept their condition, and to seek to apply the responses that best fit their child's real needs and abilities (Gomes, 2012/13). Likewise, according to Gomes (2012/13), it is of great importance that parents share information about the child to school so that the institution meets the necessary conditions for the promotion and enhancing their skills. Similarly, it is essential that these families, as well as schools, are aware of the importance of implementing strategies that enhance the development of communication, learning, and autonomy, and where students perform domestic tasks, solve problems and are stimulated in negotiation skills as a way of promoting responsibility and self-control (Silva, 2015). A close sharing relationship between family and school is a fundamental factor for the good prognosis in the evolution of the functionality of children with neurodevelopmental disorders (Martins, Acosta & Machado, 2016).
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SOD2 deficient erythroid cells up-regulate transferrin receptor and down-regulate mitochondrial biogenesis and metabolism.

SOD2 deficient erythroid cells up-regulate transferrin receptor and down-regulate mitochondrial biogenesis and metabolism.

Labeling. Total RNA from each sample was used to prepare biotinylated target RNA using standard Affymetrix protocol (http://www.affymetrix.com/support/technical/manual/expression_ manual.affx) as previously described [48]. Briefly, 5 m g of total RNA was used to generate first-strand cDNA by using a T7-linked oligo(dT) primer. After second-strand synthesis, in vitro trans- cription was performed with biotinylated UTP and CTP (Enzo Life Sciences, Farmingdale, NY). Hybridization: the target cRNA generated from each sample was processed as per manufacturer’s recommendation using a GeneChip Instrument System (Affymetrix). Briefly, spike controls were added to 6.7 m g and 10 m g fragmented cRNA before overnight hybridization on GLYCOv2 and 430 2.0 arrays, respectively. Post-processing and scanning: arrays were then washed and stained with streptavidin-phycoerythrin, before being scanned on a ScanArray 3000 (Affymetrix) using default settings and a target intensity of 250 for scaling. Quality control (QC): The amount and quality of starting total RNA and cRNA were checked with a ND-1000 Spectrophotometer (NanoDrop Technologies, Inc., Wilmington, DE) and an Agilent Bioanalyzer (Agilent Technologies, Palo Alto, CA), respectively, and/or on formaldehyde-containing agarose gels. After scanning, array images were assessed by eye to confirm scanner alignment and the absence of significant bubbles or scratches on the chip surface. GAPDH and b-actin 3 9/59 ratios were confirmed to be within acceptable limits although one Sod2 -/- specimen, showed slight RNA degradation. Gene Sifter analyses performed with and without this 4 th Sod2 -/- sample yielded similar results, and all figures/tables are derived from a
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Intragenic initiation in SETD2 deficient cells

Intragenic initiation in SETD2 deficient cells

Several genetic alterations have been associated with RCC. In particular, mutations in the Von Hippel-Lindau (VHL) gene, chromosome 3p translo- cation and mutations in the succinate dehydrogenase B (SDHB) gene have been shown to play a role in the pathogenesis of ccRCC (Cancer Genome At- las Research Network, 2013). Mutations in the VHL tumor suppressor gene account for 60% of the sporadic ccRCC and are also associated with the Von Hippel-Lindau disease, an autosomal dominant genetic disorder char- acterized by retinal angiomas, hemamgioblastomas of the central nervous system, pheochromocytomas and ccRCC. Moreover, translocations in chro- mosome 3p have been associated with ccRCC in part because the VHL gene is involved. However, translocations involving other regions of chromosome 3p, namely 3p21 also seem to be involved in the pathophysiology of ccRCC thus suggesting the presence of other tumor suppressor genes in that region. Recently, Duns et al. have identified the SETD2 gene as putative tumor suppressor in cell lines of ccRCC with 3p21 copy number loss. The SETD2 gene, the human counterpart of the Set2 gene from yeast, codes for a histone methyltransferase that is nonredundantly responsible for the trimethylation of lysine 36 of histone H3 (H3K36me3). Lack of expression of SETD2 in cells results in microsatellite instability and an elevated mutation rate which explains the association between loss of function of SETD2 and cancer (Li et al. , 2013).
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Arq. NeuroPsiquiatr.  vol.71 número11

Arq. NeuroPsiquiatr. vol.71 número11

O objetivo deste estudo é descrever como a Childhood Autism Rating Scale (CARS) se comporta em relação à Autism Diagnostic Observation Schedule (ADOS) e ao diagnóstico clínico baseado nos critérios definidos pelo Manual Diagnóstico e estatístico dos Transtornos Mentais (DSM-IV - 4ª Edição) do em crianças filhas de imigrantes. Foram avaliadas 49 crianças cujos pais imigraram para o Canadá. Nessa amostra os resultados das avaliações pelo ADOS e DSM-IV foram totalmente concordantes. Usando o ponto-de-corte padrão de 30, a CARS mostrou elevada especificidade e baixa sensibilidade. Esse estudo propõe um ponto de corte para a CARS que possa incluir o transtorno invasivo do desenvolvimento não especificado. A redução do ponto de corte para 20/21 aumentou a especificidade do instrumento para esse grupo de crianças, sem reduzir significativamente a sensibilidade.
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Genes involved in the development of autism

Genes involved in the development of autism

It is present in locus 15q21 and codes for a protein whose role is still not completely understood. However, it has already been established that it is expressed in a subgroup of human neuronal and glial cells, being the first candidate gene for dyslexia and the second associated with language disturbances. In the presence of genetic change, like a translocation, the gene is interrupted and can lead to two variants. One of these is related with the loss of attachment place to several linking factors. The second leads to the appearance of a premature stop codon and consequent loss of four amino acids at the end of the coded protein [25].
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PRACTICAL ASPECTS OF FORMATION CORPORATE COMPETENCY MODEL

PRACTICAL ASPECTS OF FORMATION CORPORATE COMPETENCY MODEL

The questions of energy investments in the regions of the world, which allowed to carry out analysis of various types of energy production, focus on enerhozberezheni and renewable energy sources. Proved the importance of investing energy sector for the entire civilized world and defined the priorities of the process. Indicated that investment in the energy sector is based on public policy, to determine possible solutions to the energy dependence of Ukraine, taking into account the international experience.

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Mitochondrial DNA variants in obesity.

Mitochondrial DNA variants in obesity.

Heritability estimates for body mass index (BMI) variation are high. For mothers and their offspring higher BMI correlations have been described than for fathers. Variation(s) in the exclusively maternally inherited mitochondrial DNA (mtDNA) might contribute to this parental effect. Thirty-two to 40 mtDNA single nucleotide polymorphisms (SNPs) were available from genome-wide association study SNP arrays (Affymetrix 6.0). For discovery, we analyzed association in a case-control (CC) sample of 1,158 extremely obese children and adolescents and 435 lean adult controls. For independent confirmation, 7,014 population-based adults were analyzed as CC sample of n = 1,697 obese cases (BMI$30 kg/m 2 ) and n = 2,373 normal weight and lean controls (BMI,25 kg/m 2 ). SNPs were analyzed as single SNPs and haplogroups determined by HaploGrep. Fisher’s two-sided exact test was used for association testing. Moreover, the D-loop was re-sequenced (Sanger) in 192 extremely obese children and adolescents and 192 lean adult controls. Association testing of detected variants was performed using Fisher’s two-sided exact test. For discovery, nominal association with obesity was found for the frequent allele G of m.8994G/A (rs28358887, p = 0.002) located in ATP6. Haplogroup W was nominally overrepresented in the controls (p = 0.039). These findings could not be confirmed independently. For two of the 252 identified D-loop variants nominal association was detected (m.16292C/T, p = 0.007, m.16189T/C, p = 0.048). Only eight controls carried the m.16292T allele, five of whom belonged to haplogroup W that was initially enriched among these controls. m.16189T/C might create an uninterrupted poly-C tract located near a regulatory element involved in replication of mtDNA. Though follow-up of some D-loop variants still is conceivable, our hypothesis of a contribution of variation in the exclusively maternally inherited mtDNA to the observed larger correlations for BMI between mothers and their offspring could not be substantiated by the findings of the present study.
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Suppression of Cpn10 increases mitochondrial fission and dysfunction in neuroblastoma cells.

Suppression of Cpn10 increases mitochondrial fission and dysfunction in neuroblastoma cells.

Altered mitochondrial dynamics are associated with mitochon- drial dysfunctions in neurodegenerative diseases. In this study, we showed that down-regulation of Cpn10 promotes mitochondrial fission and potentiates neurotoxin-induced mitochondrial dysfunc- tion and cell death. Cpn10 plays many roles in mitochondrial homeostasis. Cpn10 is considered a cooperating partner of HSP60 in protein folding processes [32]. The HSP60-Cpn10 protein complex accelerates the folding of polypeptides imported into mitochondria and reduces aggregation of unfolded inactive polypeptides. It has been reported that expression of mitochon- drial HSP proteins is up-regulated to protect against cellular damage following global brain ischemia [33]. Overexpression of Cpn10 and HSP60 suppresses cytotoxicity by inhibiting mito- chondrial depolarization and modulating mitochondrial Bcl-2 family proteins in cardiomyocytes [34]. Ectopic expression of Cpn10 increases Bcl-xL protein levels and restores the mitochon- drial membrane potential as well as reducing caspase activation in doxorubicin-treated cells [24]. In accordance with results, we have found that loss of Cpn10 promotes mitochondrial dysfunction and potentiates cytotoxicity in neuroblastoma cells. Down-regulation of Cpn10 synergistically increased mitochondrial fragmentation and dysfunction following 3-NP or 6-hydroxyl dopamine treat- ment (Figure 3 and data not shown). Our data presented here further emphasize the importance of Cpn10 in mitochondria. Cpn10 is overexpressed during carcinogenesis of the large bowel and uterine exocervix [35]. In addition, Cpn10 is up-regulated by
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Impaired bone formation in Pdia3 deficient mice.

Impaired bone formation in Pdia3 deficient mice.

gotes were intercrossed to produce timed pregnancies. At 1 p.m., we checked the vaginal plug and considered it as E0.5. Embryos were isolated at different days of the pregnancy and stained with arcridine orange (Sigma, USA) in PBS for 30 min at 37uC. After extensive washes with PBS, the embryos were examined by stereoconfocal microscopy. For detection of transgenic b-galacto- sidase activity, the embryos were subjected to X-gal (Sigma, USA) staining according to the manufacturer’s protocol. After examin- ing the embryos microscopically, RNA, DNA and protein were extracted from them using Trizol according to the manufacturer’s instruction (Invitrogen, USA). DNA was subjected to genotyping using primers described above, RNA was reverse transcribed into cDNA and amplified using primers against Pdia3, ribosomal protein s18 (S18) and neomycion (Neo). Sequences of the primer sets used for PCR are listed in Table S1.
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Arq. NeuroPsiquiatr.  vol.67 número3A

Arq. NeuroPsiquiatr. vol.67 número3A

has been a signiicant increase in the proportion of XYY males detected prenatally, mostly as a fortuitous ind- ing. These patients are at considerably increased risk for delayed language and/or motor development, and from primary school age on, there is an increased risk for child psychiatric disorders such as autism 8 . An extra Y chro-

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