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1.
Am J Public Health ; 114(S1): S103-S111, 2024 Jan.
Article En | MEDLINE | ID: mdl-38207270

Making data accessible to communities is essential for developing community-driven solutions to address health inequities. In this analytic essay, we highlight the importance of democratizing data for Native Hawaiians and Pacific Islanders (NHPIs)-diverse populations that historically have had little access to their data-in the context of achieving equity in health and the social drivers of health. We provide a framework for evaluating community accessibility of data, which includes concepts of data availability, salience, cost, and report back. We apply the framework to evaluate community accessibility of NHPI data from 29 federal data sources. In addition, we provide results from a survey of NHPI-serving community organizations in California conducted from December 2021 to February 2022 to assess community data needs. Findings reveal federal gaps in data accessibility, as well as NHPI community organizational needs for increased data accessibility, data saliency, and technical capacity. Furthermore, organization leads expressed concerns about data privacy, security, and misuse. We provide recommendations for data custodians to improve accessibility of timely, accurate, and robust data to support NHPI communities. (Am J Public Health. 2024;114(S1):S103-S111. https://doi.org/10.2105/AJPH.2023.307503).


Health Status Disparities , Native Hawaiian or Other Pacific Islander , Humans , Health Inequities
2.
Endocrinology ; 164(5)2023 03 13.
Article En | MEDLINE | ID: mdl-36740725

Exposure of pregnant F0 mouse dams to the obesogen tributyltin (TBT) predisposes unexposed male descendants to obesity and diverts mesenchymal stem cells (MSCs) toward the adipocytic lineage. TBT promotes adipogenic commitment and differentiation of MSCs in vitro. To identify TBT-induced factors predisposing MSCs toward the adipocytic fate, we exposed mouse MSCs to TBT, the peroxisome proliferator activated receptor gamma (PPARγ)-selective agonist rosiglitazone, or the retinoid X receptor (RXR)-selective agonist LG-100268. Then we determined their transcriptomal profiles to determine candidate microRNAs (miR) regulating adipogenic commitment and differentiation. Of the top 10 candidate microRNAs predicted by Ingenuity Pathway Analysis, miR-21, miR-33, and miR-223 were expressed consistent with an ability to differentially regulate target genes during adipogenesis. We found that 24-hour exposure to 50nM TBT caused miR-223 levels in MSCs to increase; expression of its target genes ZEB1, NFIB, and FOXP1 was decreased. Rosiglitazone and TBT increased miR-223 levels. This induction was inhibited by the PPARγ antagonist T0070907 but not by the RXR antagonists HX531 or UVI3003, placing miR-223 downstream of PPARγ. Chromatin immunoprecipitation confirmed TBT-induced binding of PPARγ to regulatory elements in the miR-223 promoter. miR-223 levels were elevated in white adipose tissue of F2 and F3 male descendants of pregnant F0 mouse dams exposed to 50nM TBT throughout gestation. miR-223 levels were potentiated in males fed an increased fat diet. We infer that TBT induced miR-223 expression and increased adipogenesis in MSCs through the PPARγ pathway and that transgenerationally increased expression of miR-223 plays an important role in the development of obesity caused by TBT exposure.


Mesenchymal Stem Cells , MicroRNAs , Female , Pregnancy , Male , Animals , Mice , Adipogenesis/genetics , Rosiglitazone/pharmacology , PPAR gamma/metabolism , Cell Differentiation/genetics , Obesity/genetics , Obesity/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism
3.
Endocrinology ; 164(4)2023 02 11.
Article En | MEDLINE | ID: mdl-36750942

2,4-Di-tert-butylphenol (2,4-DTBP) is an important commercial antioxidant and a toxic natural secondary metabolite that has been detected in humans. However, there is scant information regarding its toxicological effects. We asked whether 2,4-DTBP is a potential obesogen. Using a human mesenchymal stem cell adipogenesis assay, we found that exposure to 2,4-DTBP led to increased lipid accumulation and expression of adipogenic marker genes. Antagonist assays revealed that 2,4-DTBP increased lipid accumulation by activating the peroxisome proliferator-activated receptor (PPAR) γ-retinoid X receptor (RXR) heterodimer. 2,4-DTBP likely activated the PPARγ/RXRα heterodimer by activating RXRα but not directly binding to PPARγ. We confirmed that 2,4-DTBP directly bound to RXRα by solving the crystal structure of this complex, then predicted and demonstrated that related compounds could also activate RXRα. Our study demonstrated that 2,4-DTBP and related chemicals could act as obesogens and endocrine disruptors via RXRs. These data showed that 2,4-DTBP belongs to a family of compounds whose endocrine-disrupting and obesogenic effects can be strongly modulated by their chemical composition. Structure-activity studies such as the present one could help guide the rational development of safer antioxidants that do not interact with important nuclear receptors having broad effects on human development and physiology.


Adipogenesis , Mesenchymal Stem Cells , Humans , Retinoid X Receptors , PPAR gamma/metabolism , Lipids
4.
Biochem Pharmacol ; 197: 114910, 2022 03.
Article En | MEDLINE | ID: mdl-35026188

Cannabidiol (CBD) is a non-psychoactive phytocannabinoid found in the Cannabis sativa plant. Human exposure to CBD can be through recreational marijuana use, commercially available CBD-containing products, and medical treatments. Previous studies found that cannabidiol may activate the master regulator of adipogenesis, peroxisome proliferator activated receptor gamma (PPARγ). Here we investigated the effects of CBD on adipogenesis in human and mouse multipotent mesenchymal stromal stem cells (MSCs). We tested the effects of CBD on nuclear receptor activation and adipogenic potential to demonstrate the mechanism of CBD effects and employed the in vitro MSC differentiation models to assess adipogenic effects of CBD.Using transient transfection assays, we demonstrated that CBD activated mouse and human PPARγ, but not its heterodimeric partner, the retinoid 'X' receptor, RXR. Our results showed that CBD increased lipid accumulation and the expression of adipogenic genes in mouse and human MSCs in vitro. Adipogenic differentiation induced by CBD was significantly decreased by the PPARγ antagonist T0070907, supporting the hypothesis that CBD promoted differentiation via PPARγ. Taken together, our results indicate that in humans and in mice, CBD induced adipogenic differentiation in MSCs through a PPARγ-dependent mechanism.


Adipogenesis/drug effects , Cannabidiol/pharmacology , Lipogenesis/drug effects , Lipolysis/drug effects , Mesenchymal Stem Cells/drug effects , PPAR gamma/agonists , Adipogenesis/physiology , Animals , Benzamides/pharmacology , Cell Line, Transformed , Humans , Lipogenesis/physiology , Lipolysis/physiology , Mesenchymal Stem Cells/metabolism , Mice , PPAR gamma/antagonists & inhibitors , PPAR gamma/metabolism , Pyridines/pharmacology
5.
Am J Public Health ; 111(S2): S49-S52, 2021 07.
Article En | MEDLINE | ID: mdl-34314211

As of March 2021, Native Hawaiians and Pacific Islanders (NHPIs) in the United States have lost more than 800 lives to COVID-19-the highest per capita death rate in 18 of 20 US states reporting NHPI deaths. However, NHPI risks are overlooked in policy discussions. We discuss the NHPI COVID-19 Data Policy Lab and dashboard, featuring the disproportionate COVID-19 mortality burden for NHPIs. The Lab democratized NHPI data, developed community infrastructure and resources, and informed testing site and outreach policies related to health equity.


COVID-19/mortality , Health Status Disparities , Health Status Indicators , Native Hawaiian or Other Pacific Islander/statistics & numerical data , Hawaii , Humans , Risk Factors , Socioeconomic Factors
6.
Epigenetics Chromatin ; 14(1): 27, 2021 06 15.
Article En | MEDLINE | ID: mdl-34130715

BACKGROUND: A critical question emerging in the field of developmental toxicology is whether alterations in chromatin structure induced by toxicant exposure control patterns of gene expression or, instead, are structural changes that are part of a nuclear stress response. Previously, we used a mouse model to conduct a three-way comparison between control offspring, alcohol-exposed but phenotypically normal animals, and alcohol-exposed offspring exhibiting craniofacial and central nervous system structural defects. In the cerebral cortex of animals exhibiting alcohol-induced dysgenesis, we identified a dramatic increase in the enrichment of dimethylated histone H3, lysine 9 (H3K9me2) within the regulatory regions of key developmental factors driving histogenesis in the brain. However, whether this change in chromatin structure is causally involved in the development of structural defects remains unknown. RESULTS: Deep-sequencing analysis of the cortex transcriptome reveals that the emergence of alcohol-induced structural defects correlates with disruptions in the genetic pathways controlling oxidative phosphorylation and mitochondrial function. The majority of the affected pathways are downstream targets of the mammalian target of rapamycin complex 2 (mTORC2), indicating that this stress-responsive complex plays a role in propagating the epigenetic memory of alcohol exposure through gestation. Importantly, transcriptional disruptions of the pathways regulating oxidative homeostasis correlate with the emergence of increased H3K9me2 across genic, repetitive, and non-transcribed regions of the genome. However, although associated with gene silencing, none of the candidate genes displaying increased H3K9me2 become transcriptionally repressed, nor do they exhibit increased markers of canonical heterochromatin. Similar to studies in C. elegans, disruptions in oxidative homeostasis induce the chromatin looping factor SATB2, but in mammals, this protein does not appear to drive increased H3K9me2 or altered patterns of gene expression. CONCLUSIONS: Our studies demonstrate that changes in H3K9me2 associate with alcohol-induced congenital defects, but that this epigenetic change does not correlate with transcriptional suppression. We speculate that the mobilization of SATB2 and increased enrichment of H3K9me2 may be components of a nuclear stress response that preserve chromatin integrity and interactions under prolonged oxidative stress. Further, we postulate that while this response may stabilize chromatin structure, it compromises the nuclear plasticity required for normal differentiation.


Ethanol/toxicity , Histones , Oxidative Phosphorylation , Prenatal Exposure Delayed Effects , Animals , Female , Histones/metabolism , Mice , Mitochondria/metabolism , Pregnancy , Prenatal Exposure Delayed Effects/genetics , Transcriptome
7.
Environ Epigenet ; 6(1): dvaa011, 2020.
Article En | MEDLINE | ID: mdl-33214907

It is now clear that parental histories of drug use, toxicant exposure, and social stress all have a significant influence on the health and development of the next generation. However, the ability of epigenetic parental life memories to interact with subsequent gestational exposures and cumulatively modify the developmental trajectory of the offspring remains an unexplored perspective in toxicology. Studies from our laboratory have identified male-specific postnatal growth restriction in a mouse model of chronic, preconception paternal alcohol exposure. The goal of the current study was to determine if paternal alcohol use, before conception, could modify the susceptibility of the offspring to a completely separate exposure encountered by the mother during pregnancy. In independent experiments, we previously identified altered developmental programming and increased markers of severe asthma induced by gestational exposure to particulate air pollution. In this study, male mice were exposed to either the control or alcohol preconception treatments, then mated to naive females, which we subsequently exposed to an ultrafine mixture of particulate matter via inhalation. Individually, neither preconception paternal drinking nor gestational exposures to particulate air pollution impacted the postnatal growth of female offspring. However, when both exposures were combined, females displayed a 30% reduction in weight gain. Unexpectedly, this exposure paradigm resulted in a dramatic postnatal increase in litter loss due to maternal cannibalism, which prevented additional measures of offspring health. These preliminary studies provide evidence of a complex interplay between preconception life history and intrauterine environmental factors in the control of postnatal growth.

8.
Mol Metab ; 30: 161-172, 2019 12.
Article En | MEDLINE | ID: mdl-31767168

OBJECTIVES: Paternally inherited alterations in epigenetic programming are emerging as relevant factors in numerous disease states, including the growth and metabolic defects observed in fetal alcohol spectrum disorders. In rodents, chronic paternal alcohol use induces fetal growth restriction, as well as sex-specific alterations in insulin signaling and lipid homeostasis in the offspring. Based on previous studies, we hypothesized that the observed metabolic irregularities are the consequence of paternally inherited alterations liver x receptor (LXR) activity. METHODS: Male offspring of alcohol-exposed sires were challenged with a high-fat diet and the molecular pathways controlling glucose and lipid homeostasis assayed for LXR-induced alterations. RESULTS: Similar to findings in studies employing LXR agonists we found that the male offspring of alcohol-exposed sires display resistance to diet-induced obesity and improved glucose homeostasis when challenged with a high-fat diet. This improved metabolic adaptation is mediated by LXRα trans-repression of inflammatory cytokines, releasing IKKß inhibition of the insulin signaling pathway. Interestingly, paternally programmed increases in LXRα expression are liver-specific and do not manifest in the pancreas or visceral fat. CONCLUSIONS: These studies identify LXRα as a key mediator of the long-term metabolic alterations induced by preconception paternal alcohol use.


Ethanol/adverse effects , Liver X Receptors/metabolism , Obesity/etiology , Animals , Diet, High-Fat/adverse effects , Epigenesis, Genetic/genetics , Female , Fetal Alcohol Spectrum Disorders/genetics , Insulin/metabolism , Liver/metabolism , Male , Mice , Obesity/metabolism , Paternal Exposure , Pregnancy
9.
Reprod Toxicol ; 87: 11-20, 2019 08.
Article En | MEDLINE | ID: mdl-31051257

Using a mouse model, our group recently described an association between chronic paternal alcohol use prior to conception and deficits in offspring growth. Here, we sought to determine the impact of alcohol exposure on male reproductive physiology and the association of sperm-inherited noncoding RNAs with the transmission of the observed growth defects. Alcohol exposure did not appreciably alter male reproductive physiology or fertility. However, chronic alcohol use reproducibly induced late-term fetal growth restriction in the offspring, which correlated with a shift in the proportional ratio of transfer RNA-derived small RNAs to Piwi-interacting RNAs, as well as altered enrichment of microRNAs miR21, miR30, and miR142 in alcohol-exposed sperm. Although our dataset share similarities to prior works examining the impact of paternal stress on offspring phenotype, we were unable to identify any changes in plasma corticosterone, indicating alcohol may alter sperm-inherited noncoding RNAs through distinct mechanisms.


Alcohol Drinking , Fathers , Fetal Growth Retardation , Preconception Injuries , RNA, Untranslated , Spermatozoa/drug effects , Animals , Male , Mice, Inbred C57BL
10.
Proc Natl Acad Sci U S A ; 116(9): 3443-3448, 2019 02 26.
Article En | MEDLINE | ID: mdl-30808738

Early life exposure to fine particulate matter (PM) in air is associated with infant respiratory disease and childhood asthma, but limited epidemiological data exist concerning the impacts of ultrafine particles (UFPs) on the etiology of childhood respiratory disease. Specifically, the role of UFPs in amplifying Th2- and/or Th17-driven inflammation (asthma promotion) or suppressing effector T cells (increased susceptibility to respiratory infection) remains unclear. Using a mouse model of in utero UFP exposure, we determined early immunological responses to house dust mite (HDM) allergen in offspring challenged from 0 to 4 wk of age. Two mice strains were exposed throughout gestation: C57BL/6 (sensitive to oxidative stress) and BALB/C (sensitive to allergen exposure). Offspring exposed to UFPs in utero exhibited reduced inflammatory response to HDM. Compared with filtered air (FA)-exposed/HDM-challenged mice, UFP-exposed offspring had lower white blood cell counts in bronchoalveolar lavage fluid and less pronounced peribronchiolar inflammation in both strains, albeit more apparent in C57BL/6 mice. In the C57BL/6 strain, offspring exposed in utero to FA and challenged with HDM exhibited a robust response in inflammatory cytokines IL-13 and Il-17. In contrast, this response was lost in offspring exposed in utero to UFPs. Circulating IL-10 was significantly up-regulated in C57BL/6 offspring exposed to UFPs, suggesting increased regulatory T cell expression and suppressed Th2/Th17 response. Our results reveal that in utero UFP exposure at a level close to the WHO recommended PM guideline suppresses an early immune response to HDM allergen, likely predisposing neonates to respiratory infection and altering long-term pulmonary health.


Asthma/immunology , Hypersensitivity/immunology , Particulate Matter/adverse effects , Prenatal Exposure Delayed Effects/immunology , Allergens/chemistry , Allergens/toxicity , Animals , Asthma/chemically induced , Asthma/genetics , Asthma/pathology , Bronchoalveolar Lavage Fluid/immunology , Cytokines/genetics , Female , Hypersensitivity/genetics , Hypersensitivity/pathology , Immunosuppression Therapy , Lung/drug effects , Lung/pathology , Mice , Pregnancy , Prenatal Exposure Delayed Effects/pathology , Pyroglyphidae/chemistry , Th17 Cells/immunology , Th2 Cells/immunology
11.
Epigenetics Chromatin ; 12(1): 9, 2019 01 22.
Article En | MEDLINE | ID: mdl-30670059

BACKGROUND: Although clinical data support an association between paternal alcohol use and deficits in child neurocognitive development, the relationship between paternal drinking and alcohol-induced growth phenotypes remains challenging to define. Using an established mouse model of chronic exposure, previous work by our group has linked preconception paternal alcohol use to sex-specific patterns of fetal growth restriction and placental dysfunction. The aim of the present study was to investigate the long-term impact of chronic preconception paternal alcohol use on offspring growth and metabolic programming. RESULTS: Preconception paternal alcohol exposure induced a prolonged period of fetal gestation and an increased incidence of intrauterine growth restriction, which affected the male offspring to a greater extent than the females. While the female offspring of ethanol-exposed males were able to match the body weights of the controls within the first 2 weeks of postnatal life, male offspring continued to display an 11% reduction in weight at 5 weeks of age and a 6% reduction at 8 weeks of age. The observed growth deficits associated with insulin hypersensitivity in the male offspring, while in contrast, females displayed a modest lag in their glucose tolerance test. These metabolic defects were associated with an up-regulation of genes within the pro-fibrotic TGF-ß signaling pathway and increased levels of cellular hydroxyproline within the livers of the male offspring. We observed suppressed cytokine profiles within the liver and pancreas of both the male and female offspring, which correlated with the up-regulation of genes in the LiverX/RetinoidX/FarnesoidX receptor pathways. However, patterns of gene expression were highly variable between the offspring of alcohol-exposed sires. In the adult offspring of alcohol-exposed males, we did not observe any differences in the allelic expression of Igf2 or any other imprinted genes. CONCLUSIONS: The impact of paternal alcohol use on child development is poorly explored and represents a significant gap in our understanding of the teratogenic effects of ethanol. Our studies implicate paternal exposure history as an additional and important modifier of alcohol-induced growth phenotypes and challenge the current maternal-centric exposure paradigm.


Alcohol Drinking/adverse effects , Embryonic Development , Epigenesis, Genetic , Fetal Alcohol Spectrum Disorders/genetics , Metabolome , Paternal Exposure , Alcohol Drinking/genetics , Animals , Female , Male , Mice , Mice, Inbred C57BL , Paternal Inheritance , Sex Factors
12.
Mol Genet Metab ; 126(1): 53-63, 2019 01.
Article En | MEDLINE | ID: mdl-30473481

Primary mitochondrial complex I deficiency is the most common defect of the mitochondrial respiratory chain. It is caused by defects in structural components and assembly factors of this large protein complex. Mutations in the assembly factor NDUFAF5 are rare, with only five families reported to date. This study provides clinical, biochemical, molecular and functional data for four unrelated additional families, and three novel pathogenic variants. Three cases presented in infancy with lactic acidosis and classic Leigh syndrome. One patient, however, has a milder phenotype, with symptoms starting at 27 months and a protracted clinical course with improvement and relapsing episodes. She is homozygous for a previously reported mutation, p.Met279Arg and alive at 19 years with mild neurological involvement, normal lactate but abnormal urine organic acids. We found the same mutation in one of our severely affected patients in compound heterozygosity with a novel p.Lys52Thr mutation. Both patients with p.Met279Arg are of Taiwanese descent and had severe hyponatremia. Our third and fourth patients, both Caucasian, shared a common, newly described, missense mutation p.Lys109Asn which we show induces skipping of exon 3. Both Caucasian patients were compound heterozygotes, one with a previously reported Ashkenazi founder mutation while the other was negative for additional exonic variants. Whole genome sequencing followed by RNA studies revealed a novel deep intronic variant at position c.223-907A>C inducing an exonic splice enhancer. Our report adds significant new information to the mutational spectrum of NDUFAF5, further delineating the phenotypic heterogeneity of this mitochondrial defect.


Electron Transport Complex I/deficiency , Leigh Disease/genetics , Methyltransferases/genetics , Mitochondrial Diseases/genetics , Mitochondrial Proteins/genetics , Mutation , Phenotype , Adolescent , Biopsy , Child , Child, Preschool , Electron Transport Complex I/genetics , Female , Humans , Infant , Male , Pedigree , Skin/pathology , Exome Sequencing , Whole Genome Sequencing , Young Adult
13.
Epigenetics ; 12(10): 841-853, 2017.
Article En | MEDLINE | ID: mdl-28816587

The preconception environment is a significant modifier of dysgenesis and the development of environmentally-induced disease. To date, fetal alcohol spectrum disorders (FASDs) have been exclusively associated with maternal exposures, yet emerging evidence suggests male-inherited alterations in the developmental program of sperm may be relevant to the growth-restriction phenotypes of this condition. Using a mouse model of voluntary consumption, we find chronic preconception male ethanol exposure associates with fetal growth restriction, decreased placental efficiency, abnormalities in cholesterol trafficking, sex-specific alterations in the genetic pathways regulating hepatic fibrosis, and disruptions in the regulation of imprinted genes. Alterations in the DNA methylation profiles of imprinted loci have been identified in clinical studies of alcoholic sperm, suggesting the legacy of paternal drinking may transmit via heritable disruptions in the regulation of imprinted genes. However, the capacity of sperm-inherited changes in DNA methylation to broadly transmit environmentally-induced phenotypes remains unconfirmed. Using bisulphite mutagenesis and second-generation deep sequencing, we find no evidence to suggest that these phenotypes or any of the associated transcriptional changes are linked to alterations in the sperm-inherited DNA methylation profile. These observations are consistent with recent studies examining the male transmission of diet-induced phenotypes and emphasize the importance of epigenetic mechanisms of paternal inheritance beyond DNA methylation. This study challenges the singular importance of maternal alcohol exposures and suggests paternal alcohol abuse is a significant, yet overlooked epidemiological factor complicit in the genesis of alcohol-induced growth defects, and may provide mechanistic insight into the failure of FASD children to thrive postnatally.


DNA Methylation/genetics , Fetal Alcohol Spectrum Disorders/genetics , Fetal Growth Retardation/genetics , Prenatal Exposure Delayed Effects/genetics , Alcohol Drinking/adverse effects , Animals , Child , DNA Methylation/drug effects , Disease Models, Animal , Epigenesis, Genetic/drug effects , Epigenesis, Genetic/genetics , Ethanol/toxicity , Female , Fetal Alcohol Spectrum Disorders/pathology , Fetal Growth Retardation/chemically induced , Fetal Growth Retardation/pathology , Humans , Male , Mice , Phenotype , Pregnancy , Prenatal Exposure Delayed Effects/chemically induced , Prenatal Exposure Delayed Effects/pathology , Spermatozoa/drug effects , Spermatozoa/pathology
14.
World J Pediatr ; 10(1): 83-5, 2014 Feb.
Article En | MEDLINE | ID: mdl-24464670

BACKGROUND: Effects of circulatory arrest upon an inborn error of metabolism patient are unknown. METHODS: A retrospective chart review was performed of outcome and biochemical parameters obtained during palliative cardiac surgery for a mutase-deficient methylmalonic aciduria patient with Ebstein's cardiac anomaly was performed. RESULTS: The levels of ammonia, methylmalonic acid, free carnitine, and propionylcarnitine of the patient were improved. The patient survived surgery following institution of four metabolic treatment principles: 1) restriction of toxic substrate; 2) promotion of anabolism via administration of carbohydrate and lipid calories; 3) administration of detoxifying levocarnitine and sodium benzoate; and 4) cobalamin enzymatic co-factor administration. The patient died from post-operative dysrhythmia and was posthumously determined to have compound heterozygosity for mutations predicting severe, cobalamin non-responsive disease: c.322C>T/c.1233del3 (p.R108C/p.ΔI412). CONCLUSION: Metabolic decompensation is preventable during cardiopulmonary bypass and cardioplegia using four principles of metabolic treatment.


Amino Acid Metabolism, Inborn Errors/complications , Amino Acid Metabolism, Inborn Errors/metabolism , Cardiopulmonary Bypass , Heart Defects, Congenital/surgery , Amino Acid Metabolism, Inborn Errors/therapy , Humans , Infant, Newborn , Male , Palliative Care
15.
JIMD Rep ; 14: 29-35, 2014.
Article En | MEDLINE | ID: mdl-24272679

Intermittent hypoglycemia has been described in association with Alpers' syndrome, a disorder caused by mutations in the mitochondrial DNA polymerase gamma gene. In some patients hypoglycemia may define the initial disease presentation well before the onset of the classical Alpers' triad of psychomotor retardation, intractable seizures, and liver failure. Correlating with the genotype, POLG pathogenicity is a result of increased mitochondrial DNA mutability, and mitochondrial DNA depletion resulting in energy deficient states. Hypoglycemia therefore could be secondary to any metabolic pathway affected by ATP deficiency. Although it has been speculated that hypoglycemia is due to secondary fatty acid oxidation defects or abnormal gluconeogenesis, the exact underlying etiology is still unclear. Here we present detailed studies on carbohydrate metabolism in an Alpers' patient who presented initially exclusively with intermittent episodes of hypoglycemia and ketosis. Our results do not support a defect in gluconeogenesis or fatty acid oxidation as the cause of hypoglycemia. In contrast, studies performed on liver biopsy suggested abnormal glycogenolysis. This is shown via decreased activities of glycogen brancher and debrancher enzymes with normal glycogen structure and increased glycogen on histology of the liver specimen. To our knowledge, this is the first report documenting abnormalities in glycogen metabolism in a patient with Alpers' syndrome.

16.
Mol Genet Metab ; 110(4): 484-9, 2013 Dec.
Article En | MEDLINE | ID: mdl-24144945

Congenital disorders of glycosylation are a group of metabolic disorders with an expansive and highly variable clinical presentation caused by abnormal glycosylation of proteins and lipids. Dolichol kinase (DOLK) catalyzes the final step in biosynthesis of dolichol phosphate (Dol-P), which is the oligosaccharide carrier required for protein N-glycosylation. Human DOLK deficiency, also known as DOLK-CDG or CDG-Im, results in a syndrome that has been reported to manifest with dilated cardiomyopathy of variable severity. A male neonate born to non-consanguineous parents of Palestinian origin presented with dysmorphic features, genital abnormalities, talipes equinovarus, and severe, refractory generalized seizures. Additional multi-systemic manifestations developed including dilated cardiomyopathy, hepatomegaly, severe insulin-resistant hyperglycemia, and renal failure, which were ultimately fatal at age 9months. Electrospray ionization mass spectrometric (ESI-MS) analysis of transferrin identified a type I congenital disorder of glycosylation; next-generation sequencing demonstrated homozygous p.Q483K DOLK mutations that were confirmed in patient fibroblasts to result in severely reduced substrate binding and catalytic activity. This patient expands the phenotype of DOLK-CDG to include anatomic malformations and multi-systemic dysfunction.


Cardiomyopathy, Dilated/pathology , Congenital Disorders of Glycosylation/pathology , Lipid Metabolism/genetics , Phosphotransferases (Alcohol Group Acceptor)/deficiency , Amino Acid Sequence , Cardiomyopathy, Dilated/complications , Cardiomyopathy, Dilated/genetics , Congenital Disorders of Glycosylation/complications , Congenital Disorders of Glycosylation/genetics , Congenital Disorders of Glycosylation/mortality , Dolichols/metabolism , Fatal Outcome , Glycosylation , Homozygote , Humans , Infant, Newborn , Male , Mutation , Phosphotransferases (Alcohol Group Acceptor)/genetics , Phosphotransferases (Alcohol Group Acceptor)/metabolism
17.
Mol Genet Metab ; 94(4): 485-490, 2008 Aug.
Article En | MEDLINE | ID: mdl-18495510

The mitochondrial 13513G>A (D393N) mutation in the ND5 subunit of the respiratory chain complex I was initially described in association with MELAS syndrome. Recent observations have linked this mutation to Leigh disease. We screened for the 13513G>A mutation in a cohort of 265 patients with Leigh and Leigh-like disease. The mutation was found in a total of 5 patients. An additional patient who had clinical presentation consistent with a Leigh-like phenotype but with a normal brain MRI was added to the cohort. None of an additional 88 patients meeting MELAS disease criteria, nor 56 patients with respiratory chain deficiency screened for the 13513G>A were found positive for the mutation. The most frequent clinical manifestations in our patients were hypotonia, ocular and cerebellar involvement. Low mutation heteroplasmy in the range of 20-40% was observed in all 6 patients. This observation is consistent with the previously reported low heteroplasmy of this mutation in some patients with the 13513G>A mutation and complex I deficiency. However, normal complex I activity was observed in two patients in our cohort. As most patients with Leigh-like disease and the 13513G>A mutation have been described with complex I deficiency, this report adds to the previously reported subset of patients with normal respiratory complex function. We conclude that in any patient with Leigh or Leigh-like disease, testing for the 13513G>A mutation is clinically relevant and low mutant loads in blood or muscle may be considered pathogenic, in the presence of normal respiratory chain enzyme activities.


Electron Transport Complex I/deficiency , Leigh Disease/enzymology , Leigh Disease/genetics , Mitochondria/genetics , Mitochondrial Proteins/deficiency , Muscles/enzymology , Point Mutation , Amino Acid Sequence , Child, Preschool , Cohort Studies , DNA Mutational Analysis , Electron Transport Complex I/chemistry , Electron Transport Complex I/genetics , Female , Humans , Infant , Male , Mitochondria/chemistry , Mitochondria/enzymology , Mitochondrial Proteins/chemistry , Mitochondrial Proteins/genetics , Molecular Sequence Data , Muscles/chemistry , Mutation, Missense , Phenotype , Sequence Alignment
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