Pompe disease results in a Golgi-based glycosylation deficit in human induced pluripotent stem cell-derived cardiomyocytes.
J Biol Chem
; 290(5): 3121-36, 2015 Jan 30.
Article
em En
| MEDLINE
| ID: mdl-25488666
ABSTRACT
Infantile-onset Pompe disease is an autosomal recessive disorder caused by the complete loss of lysosomal glycogen-hydrolyzing enzyme acid α-glucosidase (GAA) activity, which results in lysosomal glycogen accumulation and prominent cardiac and skeletal muscle pathology. The mechanism by which loss of GAA activity causes cardiomyopathy is poorly understood. We reprogrammed fibroblasts from patients with infantile-onset Pompe disease to generate induced pluripotent stem (iPS) cells that were differentiated to cardiomyocytes (iPSC-CM). Pompe iPSC-CMs had undetectable GAA activity and pathognomonic glycogen-filled lysosomes. Nonetheless, Pompe and control iPSC-CMs exhibited comparable contractile properties in engineered cardiac tissue. Impaired autophagy has been implicated in Pompe skeletal muscle; however, control and Pompe iPSC-CMs had comparable clearance rates of LC3-II-detected autophagosomes. Unexpectedly, the lysosome-associated membrane proteins, LAMP1 and LAMP2, from Pompe iPSC-CMs demonstrated higher electrophoretic mobility compared with control iPSC-CMs. Brefeldin A induced disruption of the Golgi in control iPSC-CMs reproduced the higher mobility forms of the LAMPs, suggesting that Pompe iPSC-CMs produce LAMPs lacking appropriate glycosylation. Isoelectric focusing studies revealed that LAMP2 has a more alkaline pI in Pompe compared with control iPSC-CMs due largely to hyposialylation. MALDI-TOF-MS analysis of N-linked glycans demonstrated reduced diversity of multiantennary structures and the major presence of a trimannose complex glycan precursor in Pompe iPSC-CMs. These data suggest that Pompe cardiomyopathy has a glycan processing abnormality and thus shares features with hypertrophic cardiomyopathies observed in the congenital disorders of glycosylation.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doença de Depósito de Glicogênio Tipo II
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Miócitos Cardíacos
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Células-Tronco Pluripotentes Induzidas
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Complexo de Golgi
Limite:
Humans
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article