Age-related changes in lamin A/C expression in cardiomyocytes.
Am J Physiol Heart Circ Physiol
; 293(3): H1451-6, 2007 Sep.
Article
in En
| MEDLINE
| ID: mdl-17513488
ABSTRACT
Lamin A and C (A/C) are type V intermediate filaments that form the nuclear lamina. Lamin A/C mutations lead to reduced expression of lamin A/C and diverse phenotypes such as familial cardiomyopathies and accelerated aging syndromes. Normal aging is associated with reduced expression of lamin A/C in osteoblasts and dermal fibroblasts but has never been assessed in cardiomyocytes. Our objective was to compare the expression of lamin A/C in cardiomyocytes of old (24 mo) versus young (4 mo) C57Bl/6J mice using a well-validated mouse model of aging. Lamin B1 was used as a control. Immunohistochemical and immunofluorescence analyses showed reduced expression of lamin A/C in cardiomyocyte nuclei of old mice (proportion of nuclei expressing lamin A/C, 9% vs. 62%, P < 0.001). Lamin A/C distribution was scattered peripherally and perinuclear in old mice, whereas it was homogeneous throughout the nuclei in young mice. Western blot analyses confirmed reduced expression of lamin A/C in nuclear extracts of old mice (ratio of lamin A/C to B1, 0.6 vs. 1.2, P < 0.01). Echocardiographic studies showed increased left ventricular wall thickness with preserved cavity size (concentric remodeling), increased left ventricular mass, and a slight reduction in fractional shortening in old mice. This is the first study to show that normal aging is associated with reduced expression and altered distribution of lamin A/C in nuclei of cardiomyocytes.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Aging
/
Myocytes, Cardiac
/
Lamin Type A
Limits:
Animals
Language:
En
Journal:
Am J Physiol Heart Circ Physiol
Journal subject:
CARDIOLOGIA
/
FISIOLOGIA
Year:
2007
Document type:
Article
Affiliation country:
Canada