Exocytosis-Mediated Urinary Full-Length Megalin Excretion Is Linked With the Pathogenesis of Diabetic Nephropathy.
Diabetes
; 66(5): 1391-1404, 2017 05.
Article
em En
| MEDLINE
| ID: mdl-28289043
ABSTRACT
Efficient biomarkers for diabetic nephropathy (DN) have not been established. Using ELISA, we found previously that urinary levels of full-length megalin (C-megalin), a multiligand endocytic receptor in proximal tubules, was positively correlated with DN progression in patients with type 2 diabetes mellitus (T2DM). Here, we found that urinary extracellular vesicle (UEV) excretion and C-megalin content in UEVs or in their exosomal fraction increased along with the progression of the albuminuric stages in patients with T2DM. Cultured immortalized rat proximal tubule cells (IRPTCs) treated with fatty acid-free BSA or advanced glycation end product-modified BSA (AGE-BSA), endocytic ligands of megalin, increased EV excretion, and their C-megalin content. C-megalin excretion from IRPTCs via extracellular vesicles was significantly blocked by an exosome-specific inhibitor, GW4869, indicating that this excretion is mainly exocytosis-mediated. AGE-BSA treatment of IRPTCs caused apparent lysosomal dysfunction, which stimulated multivesicular body formation, resulting in increased exosomal C-megalin excretion. In a high-fat diet-induced, megalin-mediated kidney injury model in mice, urinary C-megalin excretion also increased via UEVs. Collectively, exocytosis-mediated urinary C-megalin excretion is associated with the development and progression of DN in patients with T2DM, particularly due to megalin-mediated lysosomal dysfunction in proximal tubules, and hence it could be a candidate biomarker linked with DN pathogenesis.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade
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Diabetes Mellitus Tipo 2
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Nefropatias Diabéticas
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Exocitose
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Vesículas Extracelulares
Tipo de estudo:
Etiology_studies
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Observational_studies
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Risk_factors_studies
Limite:
Adult
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Aged
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Aged80
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Animals
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Diabetes
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Japão