Abstract 15308: SPARC Deletion Suppresses Age-related Cardiac Inflammation
Secreted protein acidic and rich in cysteine (SPARC) is a collagen-binding matricellular protein that facilitates the formation and assembly of mature cross-linked collagen fibrils. We previously reported that aged mice exhibit increased SPARC levels in the heart, and SPARC deletion inhibits age-related collagen deposition. The present study investigated whether SPARC deletion could suppress age-related cardiac inflammation. Six groups of mice were studied: young (3-5 month old), middle-aged (10-12 m.o.) and old (18-29 m.o.) C57BL/6J wild type (WT) and SPARC-null (Null) mice (n=5-10 per group). Echocardiography and histology revealed that LV wall thickness and myocyte size were 15% and 43% increased with age in WT, respectively (both p<0.05 old versus young). These age-dependent structural changes were blunted in the Null. The pro-inflammatory chemokines Ccl5 and Ccr2 were increased in middle-aged and old WT, and Cxcl1 was increased in old WT, compared to young WT (all p<0.05). Interestingly, the age-dependent increases in Ccl5, Ccr2, and Cxcl1 were delayed in Null. Migration inhibitory factor (Mif) and Cx3cl1 showed an age-dependent increase in both WT and Null. Cxcl5 expression levels increased age-dependently only in Null, suggesting a compensatory increase for the decline of other chemokines. In summary, these results suggest that SPARC deletion slowed age-related cardiac inflammation.
Author Disclosures: H. Toba: None. L.E. de Castro Brás: None. C.F. Baicu: None. M.R. Zile: None. M.L. Lindsey: None. A.D. Bradshaw: None.
- © 2014 by American Heart Association, Inc.