RESUMO
This commentary provides an overview of the putamen as an established target site for gene therapy in treating aromatic l-amino acid decarboxylase (AADC) deficiency and Parkinson's disease, two debilitating neurological disorders that involve motor dysfunction caused by dopamine deficiencies. The neuroanatomy and the function of the putamen in motor control provide good rationales for targeting this brain structure. Additionally, the efficacy and safety of intraputaminal gene therapy demonstrate that restoration of dopamine synthesis in the putamen by using low doses of adeno-associated viral vector serotype 2 to deliver the hAADC gene is well tolerated. This restoration leads to sustained improvements in motor and nonmotor symptoms of AADC deficiency and improved uptake and conversion of exogenous l-DOPA into dopamine in Parkinson's patients.
Assuntos
Carboxiliases , Doença de Parkinson , Descarboxilases de Aminoácido-L-Aromático/genética , Descarboxilases de Aminoácido-L-Aromático/metabolismo , Terapia Genética , Humanos , Doença de Parkinson/genética , Doença de Parkinson/terapia , Putamen/metabolismoRESUMO
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 27â¯months and a protracted clinical course with improvement and relapsing episodes. She is homozygous for a previously reported mutation, p.Met279Arg and alive at 19â¯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.
Assuntos
Complexo I de Transporte de Elétrons/deficiência , Doença de Leigh/genética , Metiltransferases/genética , Doenças Mitocondriais/genética , Proteínas Mitocondriais/genética , Mutação , Fenótipo , Adolescente , Biópsia , Criança , Pré-Escolar , Complexo I de Transporte de Elétrons/genética , Feminino , Humanos , Lactente , Masculino , Linhagem , Pele/patologia , Sequenciamento do Exoma , Sequenciamento Completo do Genoma , Adulto JovemRESUMO
Inborn errors of vitamin B(12) (cobalamin) metabolism are characterized by decreased production of active cobalamin cofactors and subsequent deficiencies in the activities of methionine synthase and methylmalonyl-CoA mutase. With the recent discovery of the cblJ defect in two patients with phenotypes mimicking the cblF defect, there are nine genes known to be involved in cobalamin metabolism. The new defect is caused by mutations in the ABCD4 gene, encoding an ABC transporter. At the moment, there is no clear distinction between the cblJ and cblF defects either clinically or biochemically, and both defects result in blocks in the transport of cobalamin from the lysosome to the cytoplasm. A patient was diagnosed with hyperhomocysteinemia and methylmalonic aciduria at the age of 8 years. Incorporations of both [(14)C]propionate and [(14)C]methyltetrahydrofolate in cultured fibroblasts were within reference ranges and thus too high to allow for complementation analysis. We observed decreased synthesis of both adenosylcobalamin and methylcobalamin and accumulation of unmetabolized cyanocobalamin. Exome sequencing was performed to identify causative mutation(s) and Sanger re-sequencing was performed to validate segregation of mutation in the family. By this approach, a homozygous mutation, c.423C>G, in the ABCD4 gene was identified. Here, we report the successful application of exome sequencing for diagnosis of a rare inborn error of vitamin B(12) metabolism in a patient whose unusual presentation precluded diagnosis using standard biochemical and genetic approaches. The patient represents only the third known patient with the cblJ disorder.
Assuntos
Exoma , Erros Inatos do Metabolismo/diagnóstico , Erros Inatos do Metabolismo/genética , Mutação , Vitamina B 12/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Adolescente , Idade de Início , Alelos , Sequência de Bases , Fibroblastos/metabolismo , Genótipo , Humanos , Masculino , Erros Inatos do Metabolismo/terapia , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Linhagem , Vitamina B 12/sangueRESUMO
Keloids are tumor-like skin scars that grow as a result of the aberrant healing of skin injuries, with no effective treatment. We provide new evidence that both overexpression of plasminogen activator inhibitor-1 (PAI-1) and elevated collagen accumulation are intrinsic features of keloid fibroblasts and that these characteristics are causally linked. Using seven strains each of early passage normal and keloid fibroblasts, the keloid strains exhibited inherently elevated collagen accumulation and PAI-1 expression in serum-free, 0.1% ITS+ culture; larger increases in these parameters occurred when cells were cultured in 3% serum. To demonstrate a causal relationship between PAI-1 overexpression and collagen accumulation, normal fibroblasts were infected with PAI-1-expressing adenovirus. Such cells exhibited a two- to fourfold increase in the accumulation of newly synthesized collagen in a viral dose-dependent fashion in both monolayers and fibrin gel, provisional matrix-like cultures. Three different PAI-1-targeted small interfering RNAs, alone or in combination, produced greater than an 80% PAI-1 knockdown and reduced collagen accumulation in PAI-1-overexpressing normal or keloid fibroblasts. A vitronectin-binding mutant of PAI-1 was equipotent with wild-type PAI-1 in inducing collagen accumulation, whereas a complete protease inhibitor mutant retained approximately 50% activity. Thus, PAI-1 may use more than its protease inhibitory activity to control keloid collagen accumulation. PAI-1-targeted interventions, such as small interfering RNA and lentiviral short hairpin RNA-containing microRNA sequence suppression reported here, may have therapeutic utility in the prevention of keloid scarring.
Assuntos
Adenoviridae/genética , Colágeno/metabolismo , Fibroblastos/patologia , Queloide/patologia , Inibidor 1 de Ativador de Plasminogênio/metabolismo , RNA Interferente Pequeno/metabolismo , Supressão Genética , Adolescente , Adulto , Idoso , Células Cultivadas , Colágeno/biossíntese , Feminino , Fibroblastos/metabolismo , Fibroblastos/virologia , Humanos , Queloide/metabolismo , Masculino , Pessoa de Meia-Idade , Mutação/genética , Transdução GenéticaRESUMO
AIM: To describe the significant over-expression of fibroblast growth factor receptor 3 (FGFR3), which is a signal transduction and cell proliferation related gene in hepatocellular carcinoma (HCC). METHODS: Following DNA microarray, Northern blot and quantitative real-time PCR were employed to confirm FGFR3 expression difference in HCC tissues and surrounding non-neoplastic liver tissue. FGFR3 expression levels were further determined by immunohistochemical study in 43 cases of HCC. RESULTS: Northern blot results showed the significant over-expression of FGFR3 in HCC tissues, which was consistent with that from DNA microarray. Quantitative real-time PCR demonstrated that the mean ratio of FGFR3 mRNA to glyceraldehyde-3-phosphate dehydrogenase (GADPH) mRNA in HCC tissue was 0.250, whereas the ratio in non-neoplastic liver tissue was 0.014. Statistical analyses of 43 cases of HCC revealed that HCC scored higher than the matched non-neoplastic liver tissues. Examination of clinicopathological features revealed a strong correlation of over-expression of FGFR3 with poor tumor differentiation and high nuclear grade. CONCLUSION: Over-expression of FGFR3 may play an important role in liver carcinogenesis. FGFR3 may be an ideal candidate as a molecular marker in the diagnosis of HCC and a potential therapeutic target.