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1.
Brain ; 147(5): 1899-1913, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38242545

RESUMO

Aberrant cholesterol metabolism causes neurological disease and neurodegeneration, and mitochondria have been linked to perturbed cholesterol homeostasis via the study of pathological mutations in the ATAD3 gene cluster. However, whether the cholesterol changes were compensatory or contributory to the disorder was unclear, and the effects on cell membranes and the wider cell were also unknown. Using patient-derived cells, we show that cholesterol perturbation is a conserved feature of pathological ATAD3 variants that is accompanied by an expanded lysosome population containing membrane whorls characteristic of lysosomal storage diseases. Lysosomes are also more numerous in Drosophila neural progenitor cells expressing mutant Atad3, which exhibit abundant membrane-bound cholesterol aggregates, many of which co-localize with lysosomes. By subjecting the Drosophila Atad3 mutant to nutrient restriction and cholesterol supplementation, we show that the mutant displays heightened cholesterol dependence. Collectively, these findings suggest that elevated cholesterol enhances tolerance to pathological ATAD3 variants; however, this comes at the cost of inducing cholesterol aggregation in membranes, which lysosomal clearance only partly mitigates.


Assuntos
ATPases Associadas a Diversas Atividades Celulares , Colesterol , Lisossomos , Proteínas de Membrana , Mutação , Animais , Colesterol/metabolismo , Humanos , ATPases Associadas a Diversas Atividades Celulares/genética , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Lisossomos/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Drosophila , Membrana Celular/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo
2.
Am J Hum Genet ; 108(12): 2368-2384, 2021 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-34800363

RESUMO

The 2-oxoglutarate dehydrogenase-like (OGDHL) protein is a rate-limiting enzyme in the Krebs cycle that plays a pivotal role in mitochondrial metabolism. OGDHL expression is restricted mainly to the brain in humans. Here, we report nine individuals from eight unrelated families carrying bi-allelic variants in OGDHL with a range of neurological and neurodevelopmental phenotypes including epilepsy, hearing loss, visual impairment, gait ataxia, microcephaly, and hypoplastic corpus callosum. The variants include three homozygous missense variants (p.Pro852Ala, p.Arg244Trp, and p.Arg299Gly), three compound heterozygous single-nucleotide variants (p.Arg673Gln/p.Val488Val, p.Phe734Ser/p.Ala327Val, and p.Trp220Cys/p.Asp491Val), one homozygous frameshift variant (p.Cys553Leufs∗16), and one homozygous stop-gain variant (p.Arg440Ter). To support the pathogenicity of the variants, we developed a novel CRISPR-Cas9-mediated tissue-specific knockout with cDNA rescue system for dOgdh, the Drosophila ortholog of human OGDHL. Pan-neuronal knockout of dOgdh led to developmental lethality as well as defects in Krebs cycle metabolism, which was fully rescued by expression of wild-type dOgdh. Studies using the Drosophila system indicate that p.Arg673Gln, p.Phe734Ser, and p.Arg299Gly are severe loss-of-function alleles, leading to developmental lethality, whereas p.Pro852Ala, p.Ala327Val, p.Trp220Cys, p.Asp491Val, and p.Arg244Trp are hypomorphic alleles, causing behavioral defects. Transcript analysis from fibroblasts obtained from the individual carrying the synonymous variant (c.1464T>C [p.Val488Val]) in family 2 showed that the synonymous variant affects splicing of exon 11 in OGDHL. Human neuronal cells with OGDHL knockout exhibited defects in mitochondrial respiration, indicating the essential role of OGDHL in mitochondrial metabolism in humans. Together, our data establish that the bi-allelic variants in OGDHL are pathogenic, leading to a Mendelian neurodevelopmental disease in humans.


Assuntos
Ataxia/genética , Epilepsia/genética , Perda Auditiva/genética , Complexo Cetoglutarato Desidrogenase/genética , Mutação , Transtornos do Neurodesenvolvimento/genética , Transtornos da Visão/genética , Alelos , Animais , Células Cultivadas , Criança , Estudos de Coortes , Análise Mutacional de DNA , Drosophila melanogaster/genética , Saúde da Família , Feminino , Fibroblastos , Humanos , Masculino , Splicing de RNA
3.
Nat Rev Mol Cell Biol ; 13(10): 631-45, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23000794

RESUMO

Cell movements are essential for animal development and homeostasis but also contribute to disease. Moving cells typically extend protrusions towards a chemoattractant, adhere to the substrate, contract and detach at the rear. It is less clear how cells that migrate in interconnected groups in vivo coordinate their behaviour and navigate through natural environments. The border cells of the Drosophila melanogaster ovary have emerged as an excellent model for the study of collective cell movement, aided by innovative genetic, live imaging, and photomanipulation techniques. Here we provide an overview of the molecular choreography of border cells and its more general implications.


Assuntos
Movimento Celular , Drosophila melanogaster/citologia , Animais , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Feminino , Folículo Ovariano/citologia , Folículo Ovariano/metabolismo , Fatores de Transcrição STAT/metabolismo
4.
Am J Hum Genet ; 106(2): 272-279, 2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-32004445

RESUMO

Recent studies have identified both recessive and dominant forms of mitochondrial disease that result from ATAD3A variants. The recessive form includes subjects with biallelic deletions mediated by non-allelic homologous recombination. We report five unrelated neonates with a lethal metabolic disorder characterized by cardiomyopathy, corneal opacities, encephalopathy, hypotonia, and seizures in whom a monoallelic reciprocal duplication at the ATAD3 locus was identified. Analysis of the breakpoint junction fragment indicated that these 67 kb heterozygous duplications were likely mediated by non-allelic homologous recombination at regions of high sequence identity in ATAD3A exon 11 and ATAD3C exon 7. At the recombinant junction, the duplication allele produces a fusion gene derived from ATAD3A and ATAD3C, the protein product of which lacks key functional residues. Analysis of fibroblasts derived from two affected individuals shows that the fusion gene product is expressed and stable. These cells display perturbed cholesterol and mitochondrial DNA organization similar to that observed for individuals with severe ATAD3A deficiency. We hypothesize that the fusion protein acts through a dominant-negative mechanism to cause this fatal mitochondrial disorder. Our data delineate a molecular diagnosis for this disorder, extend the clinical spectrum associated with structural variation at the ATAD3 locus, and identify a third mutational mechanism for ATAD3 gene cluster variants. These results further affirm structural variant mutagenesis mechanisms in sporadic disease traits, emphasize the importance of copy number analysis in molecular genomic diagnosis, and highlight some of the challenges of detecting and interpreting clinically relevant rare gene rearrangements from next-generation sequencing data.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Colesterol/metabolismo , Duplicação Gênica , Recombinação Homóloga , Proteínas de Membrana/genética , Mitocôndrias/patologia , Doenças Mitocondriais/patologia , Proteínas Mitocondriais/genética , ATPases Associadas a Diversas Atividades Celulares/química , Sequência de Aminoácidos , Encefalopatias/etiologia , Encefalopatias/metabolismo , Encefalopatias/patologia , Cardiomiopatias/etiologia , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Opacidade da Córnea/etiologia , Opacidade da Córnea/metabolismo , Opacidade da Córnea/patologia , Variações do Número de Cópias de DNA , Feminino , Rearranjo Gênico , Humanos , Lactente , Recém-Nascido , Masculino , Proteínas de Membrana/química , Mitocôndrias/genética , Mitocôndrias/metabolismo , Doenças Mitocondriais/genética , Doenças Mitocondriais/metabolismo , Proteínas Mitocondriais/química , Hipotonia Muscular/etiologia , Hipotonia Muscular/metabolismo , Hipotonia Muscular/patologia , Mutação , Conformação Proteica , Convulsões/etiologia , Convulsões/metabolismo , Convulsões/patologia , Homologia de Sequência
5.
Genet Med ; 25(2): 100332, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36520152

RESUMO

PURPOSE: This study aimed to establish the genetic cause of a novel autosomal recessive neurodevelopmental disorder characterized by global developmental delay, movement disorder, and metabolic abnormalities. METHODS: We performed a detailed clinical characterization of 4 unrelated individuals from consanguineous families with a neurodevelopmental disorder. We used exome sequencing or targeted-exome sequencing, cosegregation, in silico protein modeling, and functional analyses of variants in HEK293 cells and Drosophila melanogaster, as well as in proband-derived fibroblast cells. RESULTS: In the 4 individuals, we identified 3 novel homozygous variants in oxoglutarate dehydrogenase (OGDH) (NM_002541.3), which encodes a subunit of the tricarboxylic acid cycle enzyme α-ketoglutarate dehydrogenase. In silico homology modeling predicts that c.566C>T:p.(Pro189Leu) and c.890C>A:p.(Ser297Tyr) variants interfere with the structure and function of OGDH. Fibroblasts from individual 1 showed that the p.(Ser297Tyr) variant led to a higher degradation rate of the OGDH protein. OGDH protein with p.(Pro189Leu) or p.(Ser297Tyr) variants in HEK293 cells showed significantly lower levels than the wild-type protein. Furthermore, we showed that expression of Drosophila Ogdh (dOgdh) carrying variants homologous to p.(Pro189Leu) or p.(Ser297Tyr), failed to rescue developmental lethality caused by loss of dOgdh. SpliceAI, a variant splice predictor, predicted that the c.935G>A:p.(Arg312Lys)/p.(Phe264_Arg312del) variant impacts splicing, which was confirmed through a mini-gene assay in HEK293 cells. CONCLUSION: We established that biallelic variants in OGDH cause a neurodevelopmental disorder with metabolic and movement abnormalities.


Assuntos
Transtornos dos Movimentos , Transtornos do Neurodesenvolvimento , Animais , Humanos , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Células HEK293 , Complexo Cetoglutarato Desidrogenase/genética , Complexo Cetoglutarato Desidrogenase/metabolismo , Transtornos do Neurodesenvolvimento/genética
6.
Annu Rev Neurosci ; 37: 137-59, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24821430

RESUMO

Parkinson's disease (PD) is a common neurodegenerative disease, yet the underlying causative molecular mechanisms are ill defined. Numerous observations based on drug studies and mutations in genes that cause PD point to a complex set of rather subtle mitochondrial defects that may be causative. Indeed, intensive investigation of these genes in model organisms has revealed roles in the electron transport chain, mitochondrial protein homeostasis, mitophagy, and the fusion and fission of mitochondria. Here, we attempt to synthesize results from experimental studies in diverse systems to define the precise function of these PD genes, as well as their interplay with other genes that affect mitochondrial function. We propose that subtle mitochondrial defects in combination with other insults trigger the onset and progression of disease, in both familial and idiopathic PD.


Assuntos
Mitocôndrias/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Doença de Parkinson/fisiopatologia , Animais , Humanos , Mitocôndrias/genética , Modelos Biológicos , Proteínas do Tecido Nervoso/genética , Neurônios/fisiologia , Doença de Parkinson/genética
7.
Am J Hum Genet ; 102(3): 494-504, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29478781

RESUMO

ATP synthase, H+ transporting, mitochondrial F1 complex, δ subunit (ATP5F1D; formerly ATP5D) is a subunit of mitochondrial ATP synthase and plays an important role in coupling proton translocation and ATP production. Here, we describe two individuals, each with homozygous missense variants in ATP5F1D, who presented with episodic lethargy, metabolic acidosis, 3-methylglutaconic aciduria, and hyperammonemia. Subject 1, homozygous for c.245C>T (p.Pro82Leu), presented with recurrent metabolic decompensation starting in the neonatal period, and subject 2, homozygous for c.317T>G (p.Val106Gly), presented with acute encephalopathy in childhood. Cultured skin fibroblasts from these individuals exhibited impaired assembly of F1FO ATP synthase and subsequent reduced complex V activity. Cells from subject 1 also exhibited a significant decrease in mitochondrial cristae. Knockdown of Drosophila ATPsynδ, the ATP5F1D homolog, in developing eyes and brains caused a near complete loss of the fly head, a phenotype that was fully rescued by wild-type human ATP5F1D. In contrast, expression of the ATP5F1D c.245C>T and c.317T>G variants rescued the head-size phenotype but recapitulated the eye and antennae defects seen in other genetic models of mitochondrial oxidative phosphorylation deficiency. Our data establish c.245C>T (p.Pro82Leu) and c.317T>G (p.Val106Gly) in ATP5F1D as pathogenic variants leading to a Mendelian mitochondrial disease featuring episodic metabolic decompensation.


Assuntos
Alelos , Doenças Metabólicas/genética , ATPases Mitocondriais Próton-Translocadoras/genética , Mutação/genética , Subunidades Proteicas/genética , Sequência de Aminoácidos , Sequência de Bases , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Mutação com Perda de Função/genética , Masculino , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , ATPases Mitocondriais Próton-Translocadoras/química , Subunidades Proteicas/química
8.
J Inherit Metab Dis ; 44(2): 388-400, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32383294

RESUMO

2-Oxoglutarate dehydrogenase (OGDH) is a rate-limiting enzyme in the mitochondrial TCA cycle, encoded by the OGDH gene. α-Ketoglutarate dehydrogenase (OGDH) deficiency was previously reported in association with developmental delay, hypotonia, and movement disorders and metabolic decompensation, with no genetic data provided. Using whole exome sequencing, we identified two individuals carrying a homozygous missense variant c.959A>G (p.N320S) in the OGDH gene. These individuals presented with global developmental delay, elevated lactate, ataxia and seizure. Fibroblast analysis and modeling of the mutation in Drosophila were used to evaluate pathogenicity of the variant. Skin fibroblasts from subject # 2 showed a decrease in both OGDH protein and enzyme activity. Transfection of human OGDH cDNA in HEK293 cells carrying p.N320S also produced significantly lower protein levels compared to those with wild-type cDNA. Loss of Drosophila Ogdh (dOgdh) caused early developmental lethality, rescued by expressing wild-type dOgdh (dOgdhWT ) or human OGDH (OGDHWT ) cDNA. In contrast, expression to the mutant OGDH (OGDHN320S ) or dOgdh carrying homologous mutations to human OGDH p.N320S variant (dOgdhN324S ) failed to rescue lethality of dOgdh null mutants. Knockdown of dOgdh in the nervous system resulted in locomotion defects which were rescued by dOgdhWT expression but not by dOgdhN324S expression. Collectively, the results indicate that c.959A>G variant in OGDH leads to an amino acid change (p.N320S) causing a severe loss of OGDH protein function. Our study establishes in the first time a genetic link between an OGDH gene mutation and OGDH deficiency.


Assuntos
Complexo Cetoglutarato Desidrogenase/genética , Doenças Mitocondriais/genética , Doenças do Sistema Nervoso/genética , Adolescente , Animais , Criança , Pré-Escolar , DNA/genética , Drosophila , Feminino , Expressão Gênica , Técnicas de Silenciamento de Genes , Predisposição Genética para Doença , Células HEK293 , Homozigoto , Humanos , Complexo Cetoglutarato Desidrogenase/deficiência , Masculino , Mutação de Sentido Incorreto , Adulto Jovem
9.
Am J Hum Genet ; 99(4): 831-845, 2016 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-27640307

RESUMO

ATPase family AAA-domain containing protein 3A (ATAD3A) is a nuclear-encoded mitochondrial membrane protein implicated in mitochondrial dynamics, nucleoid organization, protein translation, cell growth, and cholesterol metabolism. We identified a recurrent de novo ATAD3A c.1582C>T (p.Arg528Trp) variant by whole-exome sequencing (WES) in five unrelated individuals with a core phenotype of global developmental delay, hypotonia, optic atrophy, axonal neuropathy, and hypertrophic cardiomyopathy. We also describe two families with biallelic variants in ATAD3A, including a homozygous variant in two siblings, and biallelic ATAD3A deletions mediated by nonallelic homologous recombination (NAHR) between ATAD3A and gene family members ATAD3B and ATAD3C. Tissue-specific overexpression of borR534W, the Drosophila mutation homologous to the human c.1582C>T (p.Arg528Trp) variant, resulted in a dramatic decrease in mitochondrial content, aberrant mitochondrial morphology, and increased autophagy. Homozygous null bor larvae showed a significant decrease of mitochondria, while overexpression of borWT resulted in larger, elongated mitochondria. Finally, fibroblasts of an affected individual exhibited increased mitophagy. We conclude that the p.Arg528Trp variant functions through a dominant-negative mechanism that results in small mitochondria that trigger mitophagy, resulting in a reduction in mitochondrial content. ATAD3A variation represents an additional link between mitochondrial dynamics and recognizable neurological syndromes, as seen with MFN2, OPA1, DNM1L, and STAT2 mutations.


Assuntos
Adenosina Trifosfatases/genética , Alelos , Proteínas de Membrana/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/genética , Mutação , Doenças do Sistema Nervoso/genética , ATPases Associadas a Diversas Atividades Celulares , Adulto , Animais , Axônios/patologia , Cardiomiopatias/genética , Criança , Pré-Escolar , Variações do Número de Cópias de DNA/genética , Deficiências do Desenvolvimento/genética , Drosophila melanogaster/genética , Feminino , Fibroblastos , Homozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Hipotonia Muscular/genética , Músculos/patologia , Doenças do Sistema Nervoso/metabolismo , Doenças do Sistema Nervoso/patologia , Neurônios/patologia , Atrofia Óptica/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Síndrome , Adulto Jovem
10.
Hum Mol Genet ; 25(21): 4661-4673, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28173107

RESUMO

Four mutations in the VAMP/synaptobrevin-associated protein B (VAPB) gene have been linked to amyotrophic lateral sclerosis (ALS) type 8. The mechanism by which VAPB mutations cause motor neuron disease is unclear, but studies of the most common P56S variant suggest both loss of function and dominant-negative sequestration of wild-type protein. Diminished levels of VAPB and its proteolytic cleavage fragment have also been reported in sporadic ALS cases, suggesting that VAPB loss of function may be a common mechanism of disease. Here, we tested whether neuronal overexpression of wild-type human VAPB would attenuate disease in a mouse model of familial ALS1. We used neonatal intraventricular viral injections to express VAPB or YFP throughout the brain and spinal cord of superoxide dismutase (SOD1) G93A transgenic mice. Lifelong elevation of neuronal VAPB slowed the decline of neurological impairment, delayed denervation of hindlimb muscles, and prolonged survival of spinal motor neurons. Collectively, these changes produced a slight but significant extension in lifespan, even in this highly aggressive model of disease. Our findings lend support for a protective role of VAPB in neuromuscular health.


Assuntos
Doenças Neuromusculares/metabolismo , Proteínas de Transporte Vesicular/biossíntese , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Animais , Denervação , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Doença dos Neurônios Motores/genética , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Mutação , Doenças Neuromusculares/genética , Neurônios/metabolismo , Medula Espinal/metabolismo , Superóxido Dismutase-1/genética , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
11.
BMC Cancer ; 14: 36, 2014 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-24447339

RESUMO

BACKGROUND: Combination therapy is key to improving cancer treatment efficacy. Phorbol 12-myristate 13-acetate (PMA), a well-known PKC activator, increases the cytotoxicity of several anticancer drugs. Apicularen A induces cytotoxicity in tumor cells through disrupting microtubule networks by tubulin down-regulation. In this study, we examined whether PMA increases apicularen A-induced cytotoxicity in HeLa cells. METHODS: Cell viability was examined by thiazolyl blue tetrazolium (MTT) assays. To investigate apoptotic potential of apicularen A, DNA fragmentation assays were performed followed by extracting genomic DNA, and caspase-3 activity assays were performed by fluorescence assays using fluorogenic substrate. The cell cycle distribution induced by combination with PMA and apicularen A was examined by flow cytometry after staining with propidium iodide (PI). The expression levels of target proteins were measured by Western blotting analysis using specific antibodies, and α-tubulin mRNA levels were assessed by reverse transcription polymerase chain reaction (RT-PCR). To examine the effect of combination of PMA and apicularen A on the microtubule architecture, α-tubulin protein and nuclei were visualized by immunofluorescence staining using an anti-α-tubulin antibody and PI, respectively. RESULTS: We found that apicularen A induced caspase-dependent apoptosis in HeLa cells. PMA synergistically increased cytotoxicity and apoptotic sub-G1 population induced by apicularen A. These effects were completely blocked by the PKC inhibitors Ro31-8220 and Go6983, while caspase inhibition by Z-VAD-fmk did not prevent cytotoxicity. RNA interference using siRNA against PKCα, but not PKCß and PKCγ, inhibited cytotoxicity induced by combination PMA and apicularen A. PMA increased the apicularen A-induced disruption of microtubule networks by further decreasing α- and ß-tubulin protein levels in a PKC-dependent manner. CONCLUSIONS: These results suggest that the synergy between PMA and apicularen A is involved by PKCα activation and microtubule disruption, and that may inform the development of novel approaches to treat cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Microtúbulos/efeitos dos fármacos , Neoplasias do Colo do Útero/metabolismo , Apoptose/efeitos dos fármacos , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Caspase 3/metabolismo , Pontos de Checagem do Ciclo Celular , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Feminino , Células HeLa , Humanos , Microtúbulos/genética , Microtúbulos/metabolismo , Microtúbulos/patologia , Proteína Quinase C-alfa/antagonistas & inibidores , Proteína Quinase C-alfa/genética , Proteína Quinase C-alfa/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Interferência de RNA , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Tempo , Transfecção , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/farmacologia , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
12.
Biochem Biophys Res Commun ; 434(3): 634-40, 2013 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-23583412

RESUMO

Apicularen A is a novel antitumor agent and strongly induces death in tumor cells. In this study, we synthesized apicularen A acetate, an acetyl derivative of apicularen A, and investigated its antitumor effect and mechanism in HM7 colon cancer cells. Apicularen A acetate induced apoptotic cell death and caspase-3 activation; however, the pan-caspase inhibitor Z-VAD-fmk could not prevent this cell death. Apicularen A acetate induced the loss of mitochondrial membrane potential and the translocation of apoptosis-inducing factor (AIF) from mitochondria. In addition, apicularen A acetate significantly decreased tubulin mRNA and protein levels and induced disruption of microtubule networks. Taken together, these results indicate that the mechanism of apicularen A acetate involves caspase-independent apoptotic cell death and disruption of microtubule architecture.


Assuntos
Fator de Indução de Apoptose/metabolismo , Apoptose/efeitos dos fármacos , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Neoplasias do Colo/patologia , Regulação para Baixo/efeitos dos fármacos , Microtúbulos/efeitos dos fármacos , Tubulina (Proteína)/metabolismo , Western Blotting , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Citometria de Fluxo , Imunofluorescência , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microtúbulos/metabolismo , Transporte Proteico , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
CRISPR J ; 6(2): 176-182, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37071670

RESUMO

The CRISPR-Cas9 system has enabled researchers to precisely modify/edit the sequence of a genome. A typical editing experiment consists of two steps: (1) editing cultured cells; (2) cell cloning and selection of clones with and without intended edit, presumed to be isogenic. The application of CRISPR-Cas9 system may result in off-target edits, whereas cloning will reveal culture-acquired mutations. We analyzed the extent of the former and the latter by whole genome sequencing in three experiments involving separate genomic loci and conducted by three independent laboratories. In all experiments we hardly found any off-target edits, whereas detecting hundreds to thousands of single nucleotide mutations unique to each clone after relatively short culture of 10-20 passages. Notably, clones also differed in copy number alterations (CNAs) that were several kb to several mb in size and represented the largest source of genomic divergence among clones. We suggest that screening of clones for mutations and CNAs acquired in culture is a necessary step to allow correct interpretation of DNA editing experiments. Furthermore, since culture associated mutations are inevitable, we propose that experiments involving derivation of clonal lines should compare a mix of multiple unedited lines and a mix of multiple edited lines.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Sistemas CRISPR-Cas/genética , Mutação , DNA
14.
STAR Protoc ; 3(3): 101465, 2022 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-35719725

RESUMO

In this protocol, we take CRISPR/Cas9 and Gal4/UAS approaches to achieve tissue-specific knockout in parallel with rescue of the knockout by cDNA expression in Drosophila. We demonstrate that guide RNAs targeting the exon-intron junction of target genes cleave the genomic locus of the genes, but not UAS-cDNA transgenes, in a tissue where Gal4 drives Cas9 expression. The efficiency of this approach enables the determination of pathogenicity of disease-associated variants in human genes in a tissue-specific manner in Drosophila. For complete details on the use and execution of this protocol, please refer to Yap et al. (2021).


Assuntos
Sistemas CRISPR-Cas , Drosophila melanogaster , Animais , Sistemas CRISPR-Cas/genética , DNA Complementar/genética , Drosophila/genética , Drosophila melanogaster/genética , Éxons/genética , Íntrons
15.
BMC Cancer ; 11: 307, 2011 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-21781302

RESUMO

BACKGROUND: Polysaccharides extracted from the Phellinus linteus (PL) mushroom are known to possess anti-tumor effects. However, the molecular mechanisms responsible for the anti-tumor properties of PL remain to be explored. Experiments were carried out to unravel the anticancer effects of PL. METHODS: The anti-cancer effects of PL were examined in SW480 colon cancer cells by evaluating cell proliferation, invasion and matrix metallo-proteinase (MMP) activity. The anti-angiogenic effects of PL were examined by assessing human umbilical vein endothelial cell (HUVEC) proliferation and capillary tube formation. The in vivo effect of PL was evaluated in an athymic nude mouse SW480 tumor engraft model. RESULTS: PL (125-1000 µg/mL) significantly inhibited cell proliferation and decreased ß-catenin expression in SW480 cells. Expression of cyclin D1, one of the downstream-regulated genes of ß-catenin, and T-cell factor/lymphocyte enhancer binding factor (TCF/LEF) transcription activity were also significantly reduced by PL treatment. PL inhibited in vitro invasion and motility as well as the activity of MMP-9. In addition, PL treatment inhibited HUVEC proliferation and capillary tube formation. Tumor growth of SW480 cells implanted into nude mice was significantly decreased as a consequence of PL treatment, and tumor tissues from treated animals showed an increase in the apoptotic index and a decrease in ß-catenin expression. Moreover, the proliferation index and microvessel density were significantly decreased. CONCLUSIONS: These data suggest that PL suppresses tumor growth, invasion, and angiogenesis through the inhibition of Wnt/ß-catenin signaling in certain colon cancer cells.


Assuntos
Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Polissacarídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Carga Tumoral/efeitos dos fármacos , Agaricales/química , Animais , Western Blotting , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Ciclina D1/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Neovascularização Patológica/prevenção & controle , Phellinus , Extratos Vegetais , Polissacarídeos/metabolismo , Ligação Proteica , Fatores de Transcrição TCF/metabolismo , Proteínas Wnt/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , beta Catenina/metabolismo
16.
Pancreatology ; 11(6): 574-84, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22213040

RESUMO

BACKGROUND/AIMS: ω3-polyunsaturated fatty acids (ω3- PUFAs) are known to possess anticancer properties. However, the relationship between ω3-PUFAs and ß-catenin, one of the key components of the Wnt signaling pathway, in human pancreatic cancer remains poorly characterized. METHODS: Human pancreatic cancer cells (SW1990 and PANC-1) were exposed to two ω3-PUFAs, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), to investigate the relationship between ω3-PUFAs and the Wnt/ß-catenin signaling pathway in vitro. Mouse pancreatic cancer (PANC02) cells were implanted into fat-1 transgenic mice, which express ω3 desaturases and result in elevated levels of ω3-PUFAs endogenously. The tumor size, levels of Wnt/ß-catenin signaling molecules and apoptosis levels were analyzed to examine the influence of ω3-PUFAs in vivo. RESULTS: DHA and EPA significantly inhibited cell growth and increased cell death in pancreatic cancer cells. DHA also reduced ß-catenin expression, T cell factor/lymphoid-enhancing factor reporter activity and induced ß-catenin/Axin/GSK-3ß complex formation, a known precursor to ß-catenin degradation. Furthermore, Wnt3a, a natural canonical Wnt pathway ligand, reversed DHA-induced growth inhibition in PANC-1 cells. Immunohistochemical analysis showed aberrant upregulation and increased nuclear staining of ß-catenin in tumor tissues from pancreatic cancer patients. However, ß-catenin levels in tumor tissues from fat-1 transgenic mice were reduced with a significant increase in apoptosis compared with those from control mice. CONCLUSION: ω3-PUFAs may be an effective therapy for the chemoprevention and treatment of human pancreatic cancer. and IAP.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos/farmacologia , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Neoplasias Pancreáticas/tratamento farmacológico , Via de Sinalização Wnt/efeitos dos fármacos , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Transgênicos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Via de Sinalização Wnt/genética
17.
Genome Med ; 13(1): 55, 2021 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-33845882

RESUMO

BACKGROUND: ATPase family AAA-domain containing protein 3A (ATAD3A) is a nuclear-encoded mitochondrial membrane-anchored protein involved in diverse processes including mitochondrial dynamics, mitochondrial DNA organization, and cholesterol metabolism. Biallelic deletions (null), recessive missense variants (hypomorph), and heterozygous missense variants or duplications (antimorph) in ATAD3A lead to neurological syndromes in humans. METHODS: To expand the mutational spectrum of ATAD3A variants and to provide functional interpretation of missense alleles in trans to deletion alleles, we performed exome sequencing for identification of single nucleotide variants (SNVs) and copy number variants (CNVs) in ATAD3A in individuals with neurological and mitochondrial phenotypes. A Drosophila Atad3a Gal4 knockin-null allele was generated using CRISPR-Cas9 genome editing technology to aid the interpretation of variants. RESULTS: We report 13 individuals from 8 unrelated families with biallelic ATAD3A variants. The variants included four missense variants inherited in trans to loss-of-function alleles (p.(Leu77Val), p.(Phe50Leu), p.(Arg170Trp), p.(Gly236Val)), a homozygous missense variant p.(Arg327Pro), and a heterozygous non-frameshift indel p.(Lys568del). Affected individuals exhibited findings previously associated with ATAD3A pathogenic variation, including developmental delay, hypotonia, congenital cataracts, hypertrophic cardiomyopathy, and cerebellar atrophy. Drosophila studies indicated that Phe50Leu, Gly236Val, Arg327Pro, and Lys568del are severe loss-of-function alleles leading to early developmental lethality. Further, we showed that Phe50Leu, Gly236Val, and Arg327Pro cause neurogenesis defects. On the contrary, Leu77Val and Arg170Trp are partial loss-of-function alleles that cause progressive locomotion defects and whose expression leads to an increase in autophagy and mitophagy in adult muscles. CONCLUSION: Our findings expand the allelic spectrum of ATAD3A variants and exemplify the use of a functional assay in Drosophila to aid variant interpretation.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Variação Genética , Proteínas de Membrana/genética , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Neurônios/metabolismo , Adolescente , Alelos , Sequência de Aminoácidos , Animais , Autofagia/genética , Simulação por Computador , Drosophila/ultraestrutura , Feminino , Humanos , Lactente , Recém-Nascido , Locomoção , Masculino , Mitofagia/genética , Mutação de Sentido Incorreto/genética , Neurogênese/genética , Linhagem , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Adulto Jovem
18.
Biochim Biophys Acta ; 1791(8): 816-26, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19427405

RESUMO

Preadipocyte Factor 1 (Pref-1), also known as Delta-like Protein 1 (DLK-1) is an epidermal growth factor-like domain-containing trans-membrane protein that is involved in adipogenesis and cell fate decision. Its function in adipogenesis is reported inconsistently based on different cellular model systems. Here, by using human mesenchymal stem cells (MSCs), we show that Pref-1 is modulated by both dexamethasone and 3-isobutyl-1methylxanthine (IBMX), two components of the adipogenic induction mixture during the adipogenesis in vitro. IBMX induces the expression of Pref-1 in a time- and dose-dependent manner through cyclic AMP and cyclic GMP independent pathway and attenuates adipocyte differentiation by down-regulating PPARgamma (peroxisome proliferator activated receptor gamma) expression. Dexamethasone, on the other hand, is capable of subduing the inhibitory effect of IBMX-induced Pref-1 and initiating the adipogenesis by up-regulating PPARgamma expression. Moreover, the treatment of IBMX or dexamethasone alone fails to develop MSCs into mature adipocytes, however, treating cells with both IBMX and dexamethasone leads to a complete adipocyte differentiation as evaluated by lipid-droplet formation. Taken together, our study demonstrates that IBMX accelerates accumulation of lipid in MSCs only under the circumstance that the negative effect of Pref-1 induced by IBMX on the adipogenesis is overcome by dexamethasone.


Assuntos
Adipogenia , Regulação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Células-Tronco Mesenquimais/metabolismo , 1-Metil-3-Isobutilxantina/farmacologia , Células 3T3-L1/metabolismo , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adipogenia/efeitos dos fármacos , Animais , Proteínas de Ligação ao Cálcio , AMP Cíclico/farmacologia , GMP Cíclico/farmacologia , Dexametasona/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Indometacina/farmacologia , Insulina/farmacologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , Modelos Biológicos , Fatores de Tempo
19.
Prostate ; 70(4): 353-61, 2010 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-19866472

RESUMO

BACKGROUND: Hepatocyte nuclear factor-3alpha (HNF-3alpha) has been known to act as a repressor in the pathogenesis of many cancers. Herein, we investigated the effect of HNF-3alpha overexpression in prostate cancer cells. METHODS: HNF-3alpha was overexpressed in prostate cancer cells using an adenovirus recombinant expressing wild-type HNF-3alpha. The apoptosis of prostate cancer cells was determined by TUNEL, FACS, and caspase activity analyses. RESULTS: Adenovirus-mediated overexpression of HNF-3alpha caused cell death in prostate cancer cells as assessed by changes in cellular and nuclear morphology, TUNEL analysis, and caspase activations. Furthermore, FACS analysis showed an increased sub-G1 phase of cell cycle as well as the G2/M phase with a corresponding decrease in S phases. HNF-3alpha overexpression caused the upregulation of p53 protein and its accumulation, together with HNF-3alpha, in the cytoplasm. It also causes Bax protein to localize to the mitochondria-enriched fraction. These findings suggest that multiple apoptotic pathways seem to be involved in the HNF-3alpha-induced cell death: pathways involving the accumulation of p53 protein in the cytoplasm and subsequent cytochrome c release, and other pathways involving death receptor signaling and caspase-8 activation. CONCLUSIONS: The results of the current study suggest a novel function of HNF-3alpha as a killer of malignant prostate cancer cells, which reveals HNF-3alpha as a promising therapeutic molecule for prostate cancers.


Assuntos
Apoptose/genética , Regulação Neoplásica da Expressão Gênica , Fator 3-alfa Nuclear de Hepatócito/genética , Neoplasias da Próstata/genética , Proteína Supressora de Tumor p53/genética , Regulação para Cima , Adenoviridae/genética , Caspases/metabolismo , Fracionamento Celular , Linhagem Celular Tumoral , Citoplasma , Ativação Enzimática , Citometria de Fluxo , Vetores Genéticos/genética , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Humanos , Marcação In Situ das Extremidades Cortadas , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias da Próstata/metabolismo , Transfecção , Proteína Supressora de Tumor p53/metabolismo
20.
Stem Cells ; 27(6): 1455-62, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19492297

RESUMO

The senescence of human mesenchymal stem cells (hMSCs) causes disruption of tissue and organ maintenance, and is thus an obstacle to stem cell-based therapies for disease. Although some researchers have studied changes in the characteristics of hMSCs (decreases in differentiation ability and self-renewal), comparing young and old ages, the mechanisms of stem cell senescence have not yet been defined. In this study, we developed a growth curve for human bone marrow derived MSCs (hBMSCs) which changes into a hyperbolic state after passage number 7. Senescence associated beta-galactosidase (SA beta-gal) staining of hBMSCs showed 10% in passage 9 and 45% in passage 11. We detected an increase in endogenous superoxide levels during senescence that correlated with senescence markers (SA beta-gal, hyperbolic growth curve). Interestingly, even though endogenous superoxide increased in a replicative senescence model, the expression of APE1/Ref-1, which is sensitive to intracellular redox state, decreased. These effects were confirmed in a stress-induced senescence model by exogenous treatment with H(2)O(2). This change is related to the p53 activity that negatively regulates APE1/Ref-1. p21 expression levels, which represent p53 activity, were transiently increased in passage 9, meaning that they correlated with the expression of APE1/Ref-1. Overexpression of APE1/Ref-1 suppressed superoxide production and decreased SA beta-gal in hBMSCs. In conclusion, intracellular superoxide accumulation appears to be the main cause of the senescence of hBMSCs, and overexpression of APE1/Ref-1 can rescue cells from the senescence phenotype. Maintaining characteristics of hBMSCs by regulating intracellular reactive oxygen species production can contribute to tissue regeneration and to improved cell therapy.


Assuntos
Senescência Celular/fisiologia , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/biossíntese , Células-Tronco Mesenquimais/metabolismo , Estresse Oxidativo/fisiologia , Western Blotting , Linhagem Celular , Regulação para Baixo , Citometria de Fluxo , Expressão Gênica , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Células-Tronco Mesenquimais/citologia , Microscopia Confocal , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Superóxidos/metabolismo
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