1: Am J Physiol Heart Circ Physiol. 2000 Mar;278(3):H796-805. 

Altered molecular response to adrenoreceptor-induced cardiac hypertrophy in
Egr-1-deficient mice.

Saadane N, Alpert L, Chalifour LE.

Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General
Hospital, Montreal H3T 1E2, Quebec, Canada H3A 1A3.

Unmanipulated early growth response-1 (Egr-1)-deficient -/- mice have similar
heart-to-body weight ratios but express lower amounts of atrial natriuretic
factor (ANF), beta-myosin heavy chain (beta-MHC), skeletal actin, NGF1-A binding
protein (NAB)-2, Sp1, c-fos, c-jun, GATA-4, and Nkx2.5 than +/+ or +/- mice.
alpha-MHC, tubulin, and NAB-1 expression was similar. Isoproterenol (Iso) and
phenylephrine (PE) infusion into +/+ and -/- mice increased heart weight, ANF,
beta-MHC, skeletal actin, Sp1, NAB-2, c-fos, and c-jun expression, but induction
in -/- mice was lower. Only Iso + PE-treated +/+ mice showed induction of NAB-1,
GATA-4, and Nkx2.5. Foci of fibrosis were found in Iso + PE-treated -/- and +/+
mice. Surprisingly, vehicle-treated -/- mice displayed fibrosis and increased
Sp1, skeletal actin, Nkx2.5, and GATA-4 expression without hypertrophy. Minipump
removal caused the agonist-treated hearts and gene expression to regress to
control or near-control levels. Thus Egr-1 deficiency caused a blunted
catecholamine-induced hypertrophy response and increased sensitivity to stress.

PMID: 10710348 [PubMed - indexed for MEDLINE]


---------------------------------------------------------------