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Antonio E. Elia - One of the best experts on this subject based on the ideXlab platform.
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Concurrent AFG3L2 and SPG7 mutations associated with syndromic parkinsonism and Optic Atrophy with aberrant OPA1 processing and mitochondrial network fragmentation.
Human Mutation, 2018Co-Authors: Stefania Magri, Massimo Plumari, Valentina Fracasso, Paola Rusmini, Daniele Ghezzi, Angelo Poletti, Daniela Di Bella, Cinzia Gellera, Enrico Alfei, Antonio E. EliaAbstract:: Mitochondrial dynamics and quality control are crucial for neuronal survival and their perturbation is a major cause of neurodegeneration. m-AAA complex is an ATP-dependent metalloprotease located in the inner mitochondrial membrane and involved in protein quality control. Mutations in the m-AAA subunits AFG3L2 and paraplegin are associated with autosomal dominant spinocerebellar ataxia (SCA28) and autosomal recessive Hereditary spastic paraplegia (SPG7), respectively. We report a novel m-AAA-associated phenotype characterized by early-onset Optic Atrophy with spastic ataxia and L-dopa-responsive parkinsonism. The proband carried a de novo AFG3L2 heterozygous mutation (p.R468C) along with a heterozygous maternally inherited intragenic deletion of SPG7. Functional analysis in yeast demonstrated the pathogenic role of AFG3L2 p.R468C mutation shedding light on its pathogenic mechanism. Analysis of patient's fibroblasts showed an abnormal processing pattern of OPA1, a dynamin-related protein essential for mitochondrial fusion and responsible for most cases of Hereditary Optic Atrophy. Consistently, assessment of mitochondrial morphology revealed a severe fragmentation of the mitochondrial network, not observed in SCA28 and SPG7 patients' cells. This case suggests that coincidental mutations in both components of the mitochondrial m-AAA protease may result in a complex phenotype and reveals a crucial role for OPA1 processing in the pathogenesis of neurodegenerative disease caused by m-AAA defects.
Gómez Zaera Montse - One of the best experts on this subject based on the ideXlab platform.
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Implicació del genoma mitocondrial en malalties humanes diverses
Bellaterra : Universitat Autònoma de Barcelona, 2001Co-Authors: Gómez Zaera MontseAbstract:Consultable des del TDXTítol obtingut de la portada digitalitzadaEls resultats que es recullen a la memòria tracten sobre 4 malalties humanes i la seva associació amb alteracions al DNA mitocondrial (mtDNA). Les malalties són: atròfia òptica de Leber (LHON), ambliopia alcohol-tabac (TAA), síndrome de Wolfram (WS) i lipodistròfia associada a teràpia antiretroviral (LD). S'han estudiat 31 persones amb atròfia òptica i 18 familiars de les mateixes. En els pacients s'ha detectat una proporció de mutacions al mtDNA tipus LHON primàries del 29%, a diferència d'altres estudis mundials als quals ~90% de les persones diagnosticades amb LHON tenen alguna mutació primària. Podrien existir altres mutacions (mitocondrials o nuclears) responsables de l'atròfia òptica patida per aquests afectes. També s'ha observat recuperació visual espontània en una persona amb la mutació primària 14484C; i la penetració incompleta en familiars de malalts que són homoplàsmics per a la mateixa mutació que el pacient, i no pateixen l'atròfia òptica. Quant a la TAA, vam estudiar si l'atròfia òptica en un grup de malalts estava causada pel consum d'alcohol i/o tabac elevat, per un estat nutricional deficient, o per la presència de mutacions al mtDNA. Els pacients ambliòpics es van comparar amb dos grups control: persones alcohòliques sense alteracions visuals, i persones no alcohòliques. Els pacients amb ambliopia estaven en un estat nutricional comparable al del grup control alcohòlic. El percentatge de pacients ambliòpics amb una mutació primària LHON o >1 secundària era clarament superior al mateix percentatge en els dos grups control. La predisposició genètica deguda a la presència de les mutacions mitocondrials LHON juntament amb un consum elevat d'alcohol poden ser els responsables de l'atròfia òptica patida per molts d'aquests casos ambliòpics. En 22 pacients amb la WS vam detectar 11 mutacions al gen nuclearWFS1. Una d'aquestes mutacions (425ins16, exó 4) es va identificar al 41% dels pacients i al 50% de les famílies amb mutacions a aquest gen. En 4 i 6 famílies es van identificar delecions múltiples i mutacions puntuals tipus LHON al mtDNA, respectivament. Pensem que no s'han detectat més delecions al mtDNA perquè no s'ha disposat de mostres de teixits afectats per la síndrome (pàncrees, cervell). Únicament s'han estudiat sangs, teixit no alterat en aquesta malaltia. Quant a la LD, hem estudiat individus amb LD, un grup de persones també HIV-positives sense LD, i un segon grup control format de persones no infectades pel virus. Existeixen alteracions mitocondrials a tots els pacients amb LD, les quals no s'han detectat als controls. Les alteracions mitocondrials són conseqüència de l'aplicació de teràpies antiretrovirals altament actives, però no podem establir encara si les alteracions bioquímiques i genètiques en els mitocondris dels pacients són un pas previ i necessari en el desenvolupament de la LD.This thesis contains results about 4 different human diseases and their association to mitochondrial DNA (mtDNA) abnormalities. The diseases studied are: Leber's Hereditary Optic Atrophy (LHON), tobacco-alcohol amblyopia (TAA), Wolfram syndrome (WS) and antiretroviral therapy-related lipodystrophy (LD). Thirty-one individuals suffering Optic Atrophy and 18 relatives were studied. The proportion of primary LHON mutations among patients was 29%, in contrast to previous data on European and worldwide patients which showed that almost 90% of individuals diagnosed with LHON harboured a primary LHON mutation. Some other mutations (either in the nuclear or the mitochondrial genes) must account for the Optic Atrophy experienced by these patients. We also studied if the Optic Atrophy in a group of individuals with TAA was caused by a poor nutritional status, the abuse in toxic substances, or the presence of LHON mutations in the mtDNA. We found that the percentage of patients with TAA that had one primary mutation or more than one secondary mutation was significantly higher than such a percentage in two control groups: one group of alcoholic individuals not suffering visual abnormalities, and a second group of healthy non-alcoholic individuals. The genetic predisposition (due to the presence of mtDNA mutations) together with environmental factors (i.e., the abuse of alcohol and/or tobacco) can be the cause of the Optic Atrophy in these alcoholic patients. Eleven mutations in the nuclear gene WFS1 were detected in 22 WS patients. One 16-base pair insertion in exon 4 was identified in 41% of patients. This mutation has not been detected in other European WS patients. Six families had point mtDNA mutations (LHON mutations), but only four had mtDNA deletions in blood samples. WS typical symptoms strongly suggest a mitochondrial disorder, and we cannot discard such a hypothesis since the only available material for the study was blood, which is not an affected tissue in this syndrome. We believe that affected areas in WS patients (brain, pancreas) probably present high proportions of deleted mtDNA. Biochemical, genetic or structural abnormalities have been found in muscle mitochondria from seven HIV-positive individuals with LD who were under highly active antiretroviral therapies. These abnormalities were not detected in other HIV-positive individuals without LD, or in non-infected individuals. It remains to be determined if the mitochondrial disturbances are needed for the development of LD or whether both phenomena are separate consequences of highly active antiretroviral therapies
Gómez Zaera Montserrat - One of the best experts on this subject based on the ideXlab platform.
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Implicació del genoma mitocondrial en malalties humanes diverses
'Universitat Autonoma de Barcelona', 2001Co-Authors: Gómez Zaera MontserratAbstract:Els resultats que es recullen a la memòria tracten sobre 4 malalties humanes i la seva associació amb alteracions al DNA mitocondrial (mtDNA). Les malalties són: atròfia òptica de Leber (LHON), ambliopia alcohol-tabac (TAA), síndrome de Wolfram (WS) i lipodistròfia associada a teràpia antiretroviral (LD).S'han estudiat 31 persones amb atròfia òptica i 18 familiars de les mateixes. En els pacients s'ha detectat una proporció de mutacions al mtDNA tipus LHON primàries del 29%, a diferència d'altres estudis mundials als quals ~90% de les persones diagnosticades amb LHON tenen alguna mutació primària. Podrien existir altres mutacions (mitocondrials o nuclears) responsables de l'atròfia òptica patida per aquests afectes. També s'ha observat recuperació visual espontània en una persona amb la mutació primària 14484C; i la penetració incompleta en familiars de malalts que són homoplàsmics per a la mateixa mutació que el pacient, i no pateixen l'atròfia òptica.Quant a la TAA, vam estudiar si l'atròfia òptica en un grup de malalts estava causada pel consum d'alcohol i/o tabac elevat, per un estat nutricional deficient, o per la presència de mutacions al mtDNA. Els pacients ambliòpics es van comparar amb dos grups control: persones alcohòliques sense alteracions visuals, i persones no alcohòliques. Els pacients amb ambliopia estaven en un estat nutricional comparable al del grup control alcohòlic. El percentatge de pacients ambliòpics amb una mutació primària LHON o >1 secundària era clarament superior al mateix percentatge en els dos grups control. La predisposició genètica deguda a la presència de les mutacions mitocondrials LHON juntament amb un consum elevat d'alcohol poden ser els responsables de l'atròfia òptica patida per molts d'aquests casos ambliòpics.En 22 pacients amb la WS vam detectar 11 mutacions al gen nuclearWFS1. Una d'aquestes mutacions (425ins16, exó 4) es va identificar al 41% dels pacients i al 50% de les famílies amb mutacions a aquest gen. En 4 i 6 famílies es van identificar delecions múltiples i mutacions puntuals tipus LHON al mtDNA, respectivament. Pensem que no s'han detectat més delecions al mtDNA perquè no s'ha disposat de mostres de teixits afectats per la síndrome (pàncrees, cervell). Únicament s'han estudiat sangs, teixit no alterat en aquesta malaltia.Quant a la LD, hem estudiat individus amb LD, un grup de persones també HIV-positives sense LD, i un segon grup control format de persones no infectades pel virus. Existeixen alteracions mitocondrials a tots els pacients amb LD, les quals no s'han detectat als controls. Les alteracions mitocondrials són conseqüència de l'aplicació de teràpies antiretrovirals altament actives, però no podem establir encara si les alteracions bioquímiques i genètiques en els mitocondris dels pacients són un pas previ i necessari en el desenvolupament de la LD.This thesis contains results about 4 different human diseases and their association to mitochondrial DNA (mtDNA) abnormalities. The diseases studied are: Leber's Hereditary Optic Atrophy (LHON), tobacco-alcohol amblyopia (TAA), Wolfram syndrome (WS) and antiretroviral therapy-related lipodystrophy (LD).Thirty-one individuals suffering Optic Atrophy and 18 relatives were studied. The proportion of primary LHON mutations among patients was 29%, in contrast to previous data on European and worldwide patients which showed that almost 90% of individuals diagnosed with LHON harboured a primary LHON mutation. Some other mutations (either in the nuclear or the mitochondrial genes) must account for the Optic Atrophy experienced by these patients.We also studied if the Optic Atrophy in a group of individuals with TAA was caused by a poor nutritional status, the abuse in toxic substances, or the presence of LHON mutations in the mtDNA. We found that the percentage of patients with TAA that had one primary mutation or more than one secondary mutation was significantly higher than such a percentage in two control groups: one group of alcoholic individuals not suffering visual abnormalities, and a second group of healthy non-alcoholic individuals. The genetic predisposition (due to the presence of mtDNA mutations) together with environmental factors (i.e., the abuse of alcohol and/or tobacco) can be the cause of the Optic Atrophy in these alcoholic patients.Eleven mutations in the nuclear gene WFS1 were detected in 22 WS patients. One 16-base pair insertion in exon 4 was identified in 41% of patients. This mutation has not been detected in other European WS patients. Six families had point mtDNA mutations (LHON mutations), but only four had mtDNA deletions in blood samples. WS typical symptoms strongly suggest a mitochondrial disorder, and we cannot discard such a hypothesis since the only available material for the study was blood, which is not an affected tissue in this syndrome. We believe that affected areas in WS patients (brain, pancreas) probably present high proportions of deleted mtDNA.Biochemical, genetic or structural abnormalities have been found in muscle mitochondria from seven HIV-positive individuals with LD who were under highly active antiretroviral therapies. These abnormalities were not detected in other HIV-positive individuals without LD, or in non-infected individuals. It remains to be determined if the mitochondrial disturbances are needed for the development of LD or whether both phenomena are separate consequences of highly active antiretroviral therapies
Leon Alberta - One of the best experts on this subject based on the ideXlab platform.
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Non-syndromic isolated dominant Optic Atrophy caused by the p.R468C mutation in the AFG3L2 gene
'Spandidos Publications', 2017Co-Authors: Colavito Davide, Maritan Veronica, Suppiej Agnese, Del Giudice Elda, Mazzarolo Monica, Miotto Stefania, Farina Sofia, Dalle Carbonare Maurizio, Piermarocchi Stefano, Leon AlbertaAbstract:Background: Autosomal Dominant Optic Atrophy (DOA) is the most frequent form of Hereditary Optic Atrophy, a disease presenting with considerable inter- and intra-familial clinical variability. Although a number of mutations in different genes are now known to cause DOA, many cases remain undiagnosed. Methods: In attempt to identify the underlying genetic defect, whole exome sequencing was performed in a 19 years old male affected by isolated DOA since childhood. Results: Exome sequencing revealed a pathogenic mutation (p.R468C, c.1402C>T) in the AFG3L2 gene, a gene known to be associated with spinocerebellar ataxia. Our patient does not show any signs other than DOA. Conclusions: Our result raises the possibility that mutations in the AFG3L2 gene may be a cause of isolated autosomal dominant Optic Atrophy
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Non‑syndromic isolated dominant Optic Atrophy caused by the p.R468C mutation in the AFG3 like matrix AAA peptidase subunit 2 gene
'Spandidos Publications', 2017Co-Authors: Colavito Davide, Maritan Veronica, Suppiej Agnese, Del Giudice Elda, Mazzarolo Monica, Miotto Stefania, Farina Sofia, Dalle Carbonare Maurizio, Piermarocchi Stefano, Leon AlbertaAbstract:Autosomal dominant Optic Atrophy (DOA) is the most frequent form of Hereditary Optic Atrophy, a disease presenting with considerable inter- and intra-familial clinical variability. Although a number of mutations in different genes are now known to cause DOA, many cases remain undiagnosed. In an attempt to identify the underlying genetic defect, whole exome sequencing was performed in a 19-year-old male that had been affected by isolated DOA since childhood. The exome sequencing revealed a pathogenic mutation (p.R468C, c.1402C>T) in the AFG3 like matrix AAA peptidase subunit 2 (AFG3L2) gene, a gene known to be associated with spinocerebellar ataxia. The patient did not show any signs other than DOA. Thus, the result demonstrates the possibility that mutations in the AFG3L2 gene may be a cause of isolated autosomal DOA
Stefania Magri - One of the best experts on this subject based on the ideXlab platform.
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Concurrent AFG3L2 and SPG7 mutations associated with syndromic parkinsonism and Optic Atrophy with aberrant OPA1 processing and mitochondrial network fragmentation.
Human Mutation, 2018Co-Authors: Stefania Magri, Massimo Plumari, Valentina Fracasso, Paola Rusmini, Daniele Ghezzi, Angelo Poletti, Daniela Di Bella, Cinzia Gellera, Enrico Alfei, Antonio E. EliaAbstract:: Mitochondrial dynamics and quality control are crucial for neuronal survival and their perturbation is a major cause of neurodegeneration. m-AAA complex is an ATP-dependent metalloprotease located in the inner mitochondrial membrane and involved in protein quality control. Mutations in the m-AAA subunits AFG3L2 and paraplegin are associated with autosomal dominant spinocerebellar ataxia (SCA28) and autosomal recessive Hereditary spastic paraplegia (SPG7), respectively. We report a novel m-AAA-associated phenotype characterized by early-onset Optic Atrophy with spastic ataxia and L-dopa-responsive parkinsonism. The proband carried a de novo AFG3L2 heterozygous mutation (p.R468C) along with a heterozygous maternally inherited intragenic deletion of SPG7. Functional analysis in yeast demonstrated the pathogenic role of AFG3L2 p.R468C mutation shedding light on its pathogenic mechanism. Analysis of patient's fibroblasts showed an abnormal processing pattern of OPA1, a dynamin-related protein essential for mitochondrial fusion and responsible for most cases of Hereditary Optic Atrophy. Consistently, assessment of mitochondrial morphology revealed a severe fragmentation of the mitochondrial network, not observed in SCA28 and SPG7 patients' cells. This case suggests that coincidental mutations in both components of the mitochondrial m-AAA protease may result in a complex phenotype and reveals a crucial role for OPA1 processing in the pathogenesis of neurodegenerative disease caused by m-AAA defects.