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The role of glycolysis and mitochondrial respiration in the formation and functioning of endothelial tip cells during angiogenesis. Sci Rep 2019; 9:12608. [PMID: 31471554 PMCID: PMC6717205 DOI: 10.1038/s41598-019-48676-2] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/01/2019] [Indexed: 02/07/2023] Open
Abstract
During sprouting angiogenesis, an individual endothelial tip cell grows out from a pre-existing vascular network and guides following and proliferating stalk cells to form a new vessel. Metabolic pathways such as glycolysis and mitochondrial respiration as the major sources of adenosine 5'-triphosphate (ATP) for energy production are differentially activated in these types of endothelial cells (ECs) during angiogenesis. Therefore, we studied energy metabolism during angiogenesis in more detail in tip cell and non-tip cell human umbilical vein ECs. Small interfering RNA was used to inhibit transcription of glycolytic enzymes PFKFB3 or LDHA and mitochondrial enzyme PDHA1 to test whether inhibition of these specific pathways affects tip cell differentiation and sprouting angiogenesis in vitro and in vivo. We show that glycolysis is essential for tip cell differentiation, whereas both glycolysis and mitochondrial respiration occur during proliferation of non-tip cells and in sprouting angiogenesis in vitro and in vivo. Finally, we demonstrate that inhibition of mitochondrial respiration causes adaptation of EC metabolism by increasing glycolysis and vice versa. In conclusion, our studies show a complex but flexible role of the different metabolic pathways to produce ATP in the regulation of tip cell and non-tip cell differentiation and functioning during sprouting angiogenesis.
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Egloff C, Eldin de Pecoulas A, Mechler C, Tassin M, Mairovitz V, Corrizi F, Dussaux C, Boutron A, Simon I, Guet A, Sibiude J, Mandelbrot L, Picone O. Prenatal sonographic description of fetuses affected by pyruvate dehydrogenase or pyruvate carboxylase deficiency. Prenat Diagn 2018; 38:607-616. [PMID: 29752808 DOI: 10.1002/pd.5282] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/16/2018] [Accepted: 05/01/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Pyruvate dehydrogenase deficiency (PDHD) and pyruvate carboxylase deficiency (PCD) are diseases with severe neonatal forms, and their low prevalence makes them difficult to diagnose during pregnancy. Our objective was to describe prenatal ultrasound features that may be suggestive of these diagnoses. METHODS We analyzed 3 cases from our institution and reviewed 12 published cases of PDHD and 6 cases of PCD, recording all of the ultrasound signs, as well as magnetic resonance findings when available. Because of the small number of cases of PCD, we also included postnatal signs that could have been observed during imaging during pregnancy, for a total of 11 cases of PCD. RESULTS We conclude that PDHD can be suggested in the presence of ventriculomegaly or paraventricular cysts, associated with an abnormality of the cerebral parenchyma such as abnormal gyration or involvement of the corpus callosum. Pyruvate carboxylase deficiency can be suggested in the presence of ventriculomegaly, frontal horn impairment associated with subependymal, and paraventricular cysts. CONCLUSION When confronted to the ultrasound abnormalities we described, and after eliminating the most frequent etiologies, a metabolic deficiency should be considered. Furthermore, the hereditary character of these diseases makes that it is important to send the family with genetic advice in particular in case of history of a fetal death in utero or a death neonatal unexplained.
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Affiliation(s)
- Charles Egloff
- Service de Gynécologie Obstetrique, Hopital Louis-Mourier, Colombes, France
| | | | - Charlotte Mechler
- Department of Pathology, Hopital Universitaire Robert-Debre, Paris, France
| | - Mikael Tassin
- Service de Gynécologie Obstetrique, Hopital Louis-Mourier, Colombes, France
| | - Valerie Mairovitz
- Service de Gynécologie Obstetrique, Hopital Louis-Mourier, Colombes, France
| | - Frederic Corrizi
- Service de Gynécologie Obstetrique, Hopital Louis-Mourier, Colombes, France
| | - Chloe Dussaux
- Service de Gynécologie Obstetrique, Hopital Louis-Mourier, Colombes, France
| | - Audrey Boutron
- Biochemistry Department, Hopital Bicetre, Le Kremlin-Bicetre, France
| | | | - Agnes Guet
- Pediatric Neurology, Hopital Louis-Mourier, Colombes, France
| | - Jeanne Sibiude
- Service de Gynécologie Obstetrique, Hopital Louis-Mourier, Colombes, France
| | - Laurent Mandelbrot
- Service de Gynécologie Obstetrique, Hopital Louis-Mourier, Colombes, France
| | - Olivier Picone
- Service de Gynécologie Obstetrique, Hopital Louis-Mourier, Colombes, France
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Ciara E, Rokicki D, Halat P, Karkucińska-Więckowska A, Piekutowska-Abramczuk D, Mayr J, Trubicka J, Szymańska-Dębińska T, Pronicki M, Pajdowska M, Dudzińska M, Giżewska M, Krajewska-Walasek M, Książyk J, Sperl W, Płoski R, Pronicka E. Difficulties in recognition of pyruvate dehydrogenase complex deficiency on the basis of clinical and biochemical features. The role of next-generation sequencing. Mol Genet Metab Rep 2016; 7:70-6. [PMID: 27144126 PMCID: PMC4840431 DOI: 10.1016/j.ymgmr.2016.03.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 03/21/2016] [Indexed: 01/31/2023] Open
Abstract
Pyruvate dehydrogenase complex (PDHc) defect is a well-known cause of mitochondrial disorders (MD) with at least six responsible genes (PDHA1, PDHB, DLAT, DLD, PDHX, PDP1). The aim of this work was to assess the diagnostic value of biochemical methods in recognition of PDHc defect in Polish patients with suspicion of MD. In the first step, Western blot of the E1α subunit was performed on 86 archive muscle bioptates with suspicion of MD. In the second step, Sanger PDHA1 sequencing was performed in 21 cases with low E1α expression. In the third step, 7 patients with negative results of PDHA1 sequencing were subjected to whole-exome sequencing (WES). This protocol revealed 4 patients with PDHA1 and one with DLD mutations. Four additional probands were diagnosed outside the protocol (WES or Sanger sequencing). The molecular characterization of PDHc defect was conducted in a total of 9 probands: 5 according to and 4 off the protocol. Additionally, two affected relatives were recognized by a family study. Altogether we identified seven different PDHA1 changes, including two novel variants [c.464T > C (p.Met155Thr) and c.856_859dupACTT (p.Arg288Leufs*10)] and one DLD variant. The lactate response to glucose load in the PDHA1 subset was compared to a subset of non PDHc-related MD. Opposite responses were observed, with an increase of 23% and decrease of 27%, respectively. The results show that determining lactate response to glucose load and muscle E1α expression may contribute to distinguishing PDHc-related and other MD, however, WES is becoming the method of choice for MD diagnostics.
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Affiliation(s)
- E Ciara
- Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
| | - D Rokicki
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children's Memorial Health Institute, Warsaw, Poland
| | - P Halat
- Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
| | | | | | - J Mayr
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - J Trubicka
- Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
| | - T Szymańska-Dębińska
- Department of Pathology, The Children's Memorial Health Institute, Warsaw, Poland
| | - M Pronicki
- Department of Pathology, The Children's Memorial Health Institute, Warsaw, Poland
| | - M Pajdowska
- Department of Biochemistry and Experimental Medicine, The Children's Memorial Health Institute, Warsaw, Poland
| | - M Dudzińska
- Department of Child Neurology, Chorzowskie Centrum Pediatrii i Onkologii, Chorzów, Poland
| | - M Giżewska
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology, Pomeranian Medical University, Szczecin, Poland
| | - M Krajewska-Walasek
- Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
| | - J Książyk
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children's Memorial Health Institute, Warsaw, Poland
| | - W Sperl
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - R Płoski
- Department of Medical Genetics, Warsaw Medical University, Warsaw, Poland
| | - E Pronicka
- Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland; Department of Pediatrics, Nutrition and Metabolic Diseases, The Children's Memorial Health Institute, Warsaw, Poland
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4
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Patel KP, O’Brien TW, Subramony SH, Shuster J, Stacpoole PW. The spectrum of pyruvate dehydrogenase complex deficiency: clinical, biochemical and genetic features in 371 patients. Mol Genet Metab 2012; 106:385-94. [PMID: 22896851 PMCID: PMC4003492 DOI: 10.1016/j.ymgme.2012.03.017] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CONTEXT Pyruvate dehydrogenase complex (PDC) deficiency is a genetic mitochondrial disorder commonly associated with lactic acidosis, progressive neurological and neuromuscular degeneration and, usually, death during childhood. There has been no recent comprehensive analysis of the natural history and clinical course of this disease. OBJECTIVE We reviewed 371 cases of PDC deficiency, published between 1970 and 2010, that involved defects in subunits E1α and E1β and components E1, E2, E3 and the E3 binding protein of the complex. DATA SOURCES AND EXTRACTION English language peer-reviewed publications were identified, primarily by using PubMed and Google Scholar search engines. RESULTS Neurodevelopmental delay and hypotonia were the commonest clinical signs of PDC deficiency. Structural brain abnormalities frequently included ventriculomegaly, dysgenesis of the corpus callosum and neuroimaging findings typical of Leigh syndrome. Neither gender nor any clinical or neuroimaging feature differentiated the various biochemical etiologies of the disease. Patients who died were younger, presented clinically earlier and had higher blood lactate levels and lower residual enzyme activities than subjects who were still alive at the time of reporting. Survival bore no relationship to the underlying biochemical or genetic abnormality or to gender. CONCLUSIONS Although the clinical spectrum of PDC deficiency is broad, the dominant clinical phenotype includes presentation during the first year of life; neurological and neuromuscular degeneration; structural lesions revealed by neuroimaging; lactic acidosis and a blood lactate:pyruvate ratio ≤ 20.
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Affiliation(s)
- Kavi P. Patel
- Department of Medicine (Division of Endocrinology, Metabolism and
Diabetes), College of Medicine, University of Florida, Gainesville, FL 32611,
USA
| | - Thomas W. O’Brien
- Department of Biochemistry and Molecular Biology, College of
Medicine, University of Florida, Gainesville, FL 32611, USA
| | | | - Jonathan Shuster
- Department of Epidemiology and Health Policy Research, College of
Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Peter W. Stacpoole
- Department of Medicine (Division of Endocrinology, Metabolism and
Diabetes), College of Medicine, University of Florida, Gainesville, FL 32611,
USA
- Department of Biochemistry and Molecular Biology, College of
Medicine, University of Florida, Gainesville, FL 32611, USA
- Corresponding author at: UF College of Medicine, 1600 SW
Archer Road M2-238, P.O. Box 100226, Gainesville, FL 32610, USA. Fax: +1
352 273 9013. (P.W. Stacpoole)
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Patel KP, O'Brien TW, Subramony SH, Shuster J, Stacpoole PW. The spectrum of pyruvate dehydrogenase complex deficiency: clinical, biochemical and genetic features in 371 patients. Mol Genet Metab 2012; 105:34-43. [PMID: 22079328 PMCID: PMC3754811 DOI: 10.1016/j.ymgme.2011.09.032] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 09/27/2011] [Accepted: 09/27/2011] [Indexed: 01/01/2023]
Abstract
CONTEXT Pyruvate dehydrogenase complex (PDC) deficiency is a genetic mitochondrial disorder commonly associated with lactic acidosis, progressive neurological and neuromuscular degeneration and, usually, death during childhood. There has been no recent comprehensive analysis of the natural history and clinical course of this disease. OBJECTIVE We reviewed 371 cases of PDC deficiency, published between 1970 and 2010, that involved defects in subunits E1α and E1β and components E1, E2, E3 and the E3 binding protein of the complex. DATA SOURCES AND EXTRACTION English language peer-reviewed publications were identified, primarily by using PubMed and Google Scholar search engines. RESULTS Neurodevelopmental delay and hypotonia were the commonest clinical signs of PDC deficiency. Structural brain abnormalities frequently included ventriculomegaly, dysgenesis of the corpus callosum and neuroimaging findings typical of Leigh syndrome. Neither gender nor any clinical or neuroimaging feature differentiated the various biochemical etiologies of the disease. Patients who died were younger, presented clinically earlier and had higher blood lactate levels and lower residual enzyme activities than subjects who were still alive at the time of reporting. Survival bore no relationship to the underlying biochemical or genetic abnormality or to gender. CONCLUSIONS Although the clinical spectrum of PDC deficiency is broad, the dominant clinical phenotype includes presentation during the first year of life; neurological and neuromuscular degeneration; structural lesions revealed by neuroimaging; lactic acidosis and a blood lactate:pyruvate ratio ≤20.
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Affiliation(s)
- Kavi P. Patel
- Department of Medicine (Division of Endocrinology and Metabolism), College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Thomas W. O'Brien
- Department of Biochemistry and Molecular Biology College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | | | - Jonathan Shuster
- Epidemiology and Health Policy Research College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Peter W. Stacpoole
- Department of Medicine (Division of Endocrinology and Metabolism), College of Medicine, University of Florida, Gainesville, FL, 32611, USA
- Department of Biochemistry and Molecular Biology College of Medicine, University of Florida, Gainesville, FL, 32611, USA
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Imbard A, Boutron A, Vequaud C, Zater M, de Lonlay P, de Baulny HO, Barnerias C, Miné M, Marsac C, Saudubray JM, Brivet M. Molecular characterization of 82 patients with pyruvate dehydrogenase complex deficiency. Structural implications of novel amino acid substitutions in E1 protein. Mol Genet Metab 2011; 104:507-16. [PMID: 21914562 DOI: 10.1016/j.ymgme.2011.08.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2011] [Revised: 08/10/2011] [Accepted: 08/10/2011] [Indexed: 11/28/2022]
Abstract
BACKGROUND Pyruvate dehydrogenase complex (PDHc) deficiencies are an important cause of primary lactic acidosis. Most cases result from mutations in the X-linked gene for the pyruvate dehydrogenase E1α subunit (PDHA1) while a few cases result from mutations in genes for E1β (PDHB), E2 (DLAT), E3 (DLD) and E3BP (PDHX) subunits or PDH-phosphatase (PDP1). AIM To report molecular characterization of 82 PDHc-deficient patients and analyze structural effects of novel missense mutations in PDHA1. METHODS PDHA1 variations were investigated first, by exon sequencing using a long range PCR product, gene dosage assay and cDNA analysis. Mutation scanning in PDHX, PDHB, DLAT and DLD cDNAs was further performed in unsolved cases. Novel missense mutations in PDHA1 were located on the tridimensional model of human E1 protein to predict their possible functional consequences. RESULTS PDHA1 mutations were found in 30 girls and 35 boys. Three large rearrangements, including two contiguous gene deletion syndrome were identified. Novel missense, frameshift and splicing mutations were also delineated and a nonsense mutation in a mosaic male. Mutations p.Glu75Ala, p.Arg88Ser, p.Arg119Trp, p.Gly144Asp, p.Pro217Arg, p.Arg235Gly, p.Tyr243Cys, p.Tyr243Ser, p.Arg245Gly, p.Pro250Leu, p.Gly278Arg, p.Met282Val, p.Gly298Glu in PDHA1 were predicted to impair active site channel conformation or subunit interactions. Six out of the seven patients with PDHB mutations displayed the recurrent p.Met101Val mutation; 9 patients harbored PDHX mutations and one patient DLD mutations. CONCLUSION We provide an efficient stepwise strategy for mutation screening in PDHc genes and expand the growing list of PDHA1 mutations analyzed at the structural level.
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Affiliation(s)
- A Imbard
- Biochimie-Hôpital de Bicêtre, Hôpitaux Universitaires Paris-Sud, AP-HP, Paris, France
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7
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Singer BH, Iyer RK, Kerr DS, Ahmad A. Deletion at chromosomal band Xp22.12-Xp22.13 involving PDHA1 in a patient with congenital lactic acidosis. Mol Genet Metab 2010; 101:87-9. [PMID: 20591708 DOI: 10.1016/j.ymgme.2010.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 05/18/2010] [Accepted: 05/18/2010] [Indexed: 11/23/2022]
Abstract
We present a patient with congenital lactic acidosis, agenesis of the corpus callosum, and profound developmental delay. Assays of pyruvate dehydrogenase complex function were normal in lymphocytes, but decreased in fibroblasts. Sequencing of the PDHA1 gene did not reveal deleterious mutations, and BAC based microarray analysis did not reveal any chromosomal abnormality. However, gene dosage analysis with oligonucleotide-based chromosomal microarray revealed a deletion of Xp22.12-Xp22.13 involving complete deletion of PDHA1. This is the first report of a whole gene deletion of PDHA1 detected by oligonucleotide-based microarray.
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Barnerias C, Saudubray JM, Touati G, De Lonlay P, Dulac O, Ponsot G, Marsac C, Brivet M, Desguerre I. Pyruvate dehydrogenase complex deficiency: four neurological phenotypes with differing pathogenesis. Dev Med Child Neurol 2010; 52:e1-9. [PMID: 20002125 DOI: 10.1111/j.1469-8749.2009.03541.x] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM To describe the phenotype and genotype of pyruvate dehydrogenase complex (PDHc) deficiency. METHOD Twenty-two participants with enzymologically and genetically confirmed PDHc deficiency were analysed for clinical and imaging features over a 15-year period. RESULTS Four groups were identified: (1) those with neonatal encephalopathy with lactic acidosis (one male, four females; diagnosis at birth); (2) those with non-progressive infantile encephalopathy (three males, three females; age at diagnosis 2-9mo); (3) those with Leigh syndrome (eight males; age at diagnosis 1-13mo); and (4) those with relapsing ataxia (three males; 18-30mo). Seventeen mutations involved PDHA1 (a hotspot was identified in exons 6, 7, and 8 in seven males with Leigh syndrome or recurrent ataxia). Mutations in the PDHX gene (five cases) were correlated with non-progressive encephalopathy and long-term survival in four cases. INTERPRETATION Two types of neurological involvement were identified. Abnormal prenatal brain development resulted in severe non-progressive encephalopathy with callosal agenesis, gyration anomalies, microcephaly with intrauterine growth retardation, or dysmorphia in both males and females (12 cases). Acute energy failure in infant life produced basal ganglia lesions with paroxysmal dystonia, neuropathic ataxia due to axonal transport dysfunction, or epilepsy only in males (11 cases). The ketogenic diet improved only paroxysmal dysfunction, providing an additional argument in favour of paroxysmal energy failure.
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Boichard A, Venet L, Naas T, Boutron A, Chevret L, de Baulny HO, De Lonlay P, Legrand A, Nordman P, Brivet M. Two silent substitutions in the PDHA1 gene cause exon 5 skipping by disruption of a putative exonic splicing enhancer. Mol Genet Metab 2008; 93:323-30. [PMID: 18023225 DOI: 10.1016/j.ymgme.2007.09.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 09/28/2007] [Accepted: 09/28/2007] [Indexed: 01/28/2023]
Abstract
BACKGROUND Synonymous mutations within exons may cause aberrant splicing by disrupting exonic splicing enhancer (ESE) motifs in the vicinity of non consensus splice sites. Mutational analysis of PDHA1 revealed only one silent single nucleotide substitution in exon 5 in two unrelated boys and a girl (c.483C>T and c.498C>T variants, respectively). For both patients, pyruvate dehydrogenase complex activity was low and the immunoreactive E1alpha protein was defective in cultured fibroblasts. METHODS AND RESULTS One of the boys was a somatic mosaic for the c.483C>T variant, as shown by the variable ratio of mutant to normal alleles in fibroblast, lymphocyte and single hair root DNA. Transcript analysis in fibroblasts from the three patients revealed the presence of both normal and truncated cDNAs, with the splicing out of exon 5 predicted to result in a frame shift and premature termination (p.Arg141AlafsX11). The treatment of fibroblasts with emetine before harvesting to prevent nonsense mRNA-mediated decay increased the amount of mutant mRNA. In silico analysis revealed that each variant disrupted a putative SRp55 binding site and that the intron 5 donor splice site (5'ss) contained a weak splicing signal. Transient transfection of COS-7 or Hela cells with hybrid minigene constructs containing wild-type or mutant PDHA1 exon 5, followed by RT-PCR demonstrated that each variant resulted in the incomplete inclusion of PDHA1 exon 5, and that this defect was corrected following the restoration of a perfect consensus sequence for the 5' splice site by site-directed mutagenesis. CONCLUSION These two synonymous mutations expand the spectrum of rare PDHA1 splicing mutations, all of which are located in non canonical splice sites.
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Affiliation(s)
- A Boichard
- Biochemistry laboratory, AP-HP hôpital de Bicêtre, Le Kremlin-Bicêtre, France
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Han Z, Gorbatyuk M, Thomas J, Lewin AS, Srivastava A, Stacpoole PW. Down-regulation of expression of rat pyruvate dehydrogenase E1alpha gene by self-complementary adeno-associated virus-mediated small interfering RNA delivery. Mitochondrion 2007; 7:253-9. [PMID: 17392036 PMCID: PMC1973157 DOI: 10.1016/j.mito.2007.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 02/08/2007] [Indexed: 11/24/2022]
Abstract
Mutations in the E1alpha subunit gene (PDHA1) of the pyruvate dehydrogenase complex (PDC) are common causes of congenital lactic acidosis. An animal model of E1alpha deficiency could provide insight into the pathological consequences of mutations and serve to test potential therapies. Small interfering RNAs (siRNAs) were designed to cleave the messenger RNA (mRNA) of the E1alpha subunit and were tested in vitro to assess the feasibility of producing a gene knockdown in rats. HEK 293 cells were co-transfected with a rat PDHA1 expression vector and eight naked siRNAs that specifically targeted rat E1alpha mRNA. Quantitative PCR (qPCR) analyses showed that four siRNAs reduced rat PDHA1 RNA levels up to 85% by 24h and up to 65% by 56h, compared to negative and positive controls. Since oligonucleotide-mediated siRNA delivery provided only transient suppression, we next selected two siRNA candidates and generated self-complementary, double-stranded adeno-associated virus (scAAV) vectors (serotypes 2 and 5) expressing a rat short hairpin siRNA expression cassette (scAAVsi-PDHA1). Rat lung fibroblast (RLF) cultures were infected with scAAVsi-PDHA1 vectors. The RLF PDHA1 mRNA level was reduced 53-80% 72h after infection and 54-70% 10 days after infection in RLF cultures. The expression of E1alpha and the specific activity of pyruvate dehydrogenase were also decreased at 10 days after infection in RLF cultures. Thus, scAAV siRNA-mediated knockdown of PDHA1 gene expression provides a strategy that may be applied to create a useful animal model of PDC deficiency.
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Affiliation(s)
- Zongchao Han
- Department of Pediatrics (Division of Cellular and Molecular Therapy), University of Florida, College of Medicine, Gainesville, FL 32610, USA
| | - Marina Gorbatyuk
- Department of Molecular Genetics and Microbiology, University of Florida, College of Medicine, Gainesville, FL 32610, USA
| | - James Thomas
- Department of Molecular Genetics and Microbiology, University of Florida, College of Medicine, Gainesville, FL 32610, USA
| | - Alfred S. Lewin
- Department of Molecular Genetics and Microbiology, University of Florida, College of Medicine, Gainesville, FL 32610, USA
| | - Arun Srivastava
- Department of Pediatrics (Division of Cellular and Molecular Therapy), University of Florida, College of Medicine, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida, College of Medicine, Gainesville, FL 32610, USA
- the General Clinical Research Center, University of Florida, College of Medicine, Gainesville, FL 32610, USA
| | - Peter W. Stacpoole
- Department of Medicine (Division of Endocrinology and Metabolism), University of Florida, College of Medicine, Gainesville, FL 32610, USA
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, FL 32610, USA
- the General Clinical Research Center, University of Florida, College of Medicine, Gainesville, FL 32610, USA
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Clendenning M, Hampel H, LaJeunesse J, Lindblom A, Lockman J, Nilbert M, Senter L, Sotamaa K, de la Chapelle A. Long-range PCR facilitates the identification of PMS2-specific mutations. Hum Mutat 2006; 27:490-5. [PMID: 16619239 DOI: 10.1002/humu.20318] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Mutations within the DNA mismatch repair gene, "postmeiotic segregation increased 2" (PMS2), have been associated with a predisposition to hereditary nonpolyposis colorectal cancer (HNPCC; Lynch syndrome). The presence of a large family of highly homologous PMS2 pseudogenes has made previous attempts to sequence PMS2 very difficult. Here, we describe a novel method that utilizes long-range PCR as a way to preferentially amplify PMS2 and not the pseudogenes. A second, exon-specific, amplification from diluted long-range products enables us to obtain a clean sequence that shows no evidence of pseudogene contamination. This method has been used to screen a cohort of patients whose tumors were negative for the PMS2 protein by immunohistochemistry and had not shown any mutations within the MLH1 gene. Sequencing of the PMS2 gene from 30 colorectal and 11 endometrial cancer patients identified 10 novel sequence changes as well as 17 sequence changes that had previously been identified. In total, putative pathologic mutations were detected in 11 of the 41 families. Among these were five novel mutations, c.705+1G>T, c.736_741del6ins11, c.862_863del, c.1688G>T, and c.2007-1G>A. We conclude that PMS2 mutation detection in selected Lynch syndrome and Lynch syndrome-like patients is both feasible and desirable.
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Affiliation(s)
- Mark Clendenning
- Human Cancer Genetics Program, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA
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12
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Schiff M, Miné M, Brivet M, Marsac C, Elmaleh-Bergés M, Evrard P, Ogier de Baulny H. Leigh's disease due to a new mutation in the PDHX gene. Ann Neurol 2006; 59:709-14. [PMID: 16566017 DOI: 10.1002/ana.20818] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To describe the clinical course, neuroradiological presentation, biochemical and molecular studies of a new patient with pyruvate dehydrogenase complex (PDHc) deficiency. To compare this case with the data on other published cases. METHODS Brain magnetic resonance imaging (MRI), basal metabolic investigations with lactate measurements in body fluids, PDHc activity assay on cultured skin fibroblasts, immunoblot analysis and molecular studies (polymerase chain reaction [PCR] and sequencing procedures). RESULTS Our patient accused an unspecific encephalopathy for years and presented at 13 years of age an acute deterioration with basal ganglia necrosis and subcortical white matter involvement. PDHc deficiency was secondary to a large deletion (3913 bp) in the PDHX gene, which encodes E3 binding protein (E3BP) subunit. INTERPRETATION These data provide an additional case of E3BP deficiency with a unique and previously unreported deletion in the PDHX gene.
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Affiliation(s)
- Manuel Schiff
- Service de Neuropédiatrie et Maladies métaboliques, Hôpital Robert Debré, Paris, France.
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