Effect of Hypertriglyceridemia on Beta Cell Mass and Function in ApoC3 Transgenic Mice.
J Biol Chem
; 291(28): 14695-705, 2016 Jul 08.
Article
en En
| MEDLINE
| ID: mdl-27226540
ABSTRACT
Hypertriglyceridemia results from increased production and decreased clearance of triglyceride-rich very low-density lipoproteins, a pathological condition that accounts for heightened risk of ischemic vascular diseases in obesity and type 2 diabetes. Despite its intimate association with insulin resistance, whether hypertriglyceridemia constitutes an independent risk for beta cell dysfunction in diabetes is unknown. Answering this fundamental question is stymied by the fact that hypertriglyceridemia is intertwined with hyperglycemia and insulin resistance in obese and diabetic subjects. To circumvent this limitation, we took advantage of apolipoprotein C3 (ApoC3)-transgenic mice, a model with genetic predisposition to hypertriglyceridemia. We showed that ApoC3-transgenic mice, as opposed to age/sex-matched wild-type littermates, develop hypertriglyceridemia with concomitant elevations in plasma cholesterol and non-esterified fatty acid levels. Anti-insulin and anti-glucagon dual immunohistochemistry in combination with morphometric analysis revealed that ApoC3-transgenic and wild-type littermates had similar beta cell and alpha cell masses as well as islet size and architecture. These effects correlated with similar amplitudes of glucose-stimulated insulin secretion and similar degrees of postprandial glucose excursion in ApoC3-transgenic versus wild-type littermates. Oil Red O histology did not visualize lipid infiltration into islets, correlating with the lack of ectopic triglyceride and cholesterol depositions in the pancreata of ApoC3-transgenic versus wild-type littermates. ApoC3-transgenic mice, despite persistent hypertriglyceridemia, maintained euglycemia under both fed and fasting conditions without manifestation of insulin resistance and fasting hyperinsulinemia. Thus, hypertriglyceridemia per se is not an independent risk factor for beta cell dysfunction in ApoC3 transgenic mice.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Hipertrigliceridemia
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Diabetes Mellitus Tipo 2
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Células Secretoras de Insulina
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Apolipoproteína C-III
Tipo de estudio:
Prognostic_studies
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Risk_factors_studies
Límite:
Animals
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Female
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Humans
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Male
Idioma:
En
Revista:
J Biol Chem
Año:
2016
Tipo del documento:
Article