ADENOVIRUS-MEDIATED OVEREXPRESSION OF HUMAN TRANSFORMING GROWTH-FACTOR-BETA-1 IN RAT CARDIAC FIBROBLASTS, MYOCYTES AND SMOOTH-MUSCLE CELLS

Transforming growth factor-beta 1 (TGF-beta 1) is known to regulate ca rdiac cell function and its overexpression in the heart is thought to contribute to the development of cardiac hypertrophy and fibrosis. We wished to develop a high efficiency gene transfer method that could be used both in vitro and in vivo and result in the overexpression of TG F-beta 1. For this purpose, we constructed a replication-deficient hum an adenovirus 5 vector encoding for human TGF-beta 1 and used for cont rol purposes an adenovirus lacZ vector, The adenovirus 5 construct was capable of infecting neonatal rat cardiac myocytes, fibroblasts and V SMCs, Of the three cell types, cardiac myocytes appear more susceptibl e to infection by the adenovirus 5 construct as assessed through beta- galactosidase staining. Infection of cardiac fibroblasts, myocytes and VSMCs with the hTGF-beta 1 adenovirus leads to the expression of hTGF -beta 1 mRNA and enhanced levels of bioactive and total TGF-beta 1 pro tein. Infection with hTGF-beta 1 adenovirus also results in enhanced l evels of collagen type III gene expression in VSMCs and fibroblasts wh ereas in cardiac myocytes it leads to increased levels for sarcomeric and beta-actin. Thus, this adenoviral Vector might be used for the exp loration of in vivo effects of altered levels of cardiac TGF-beta 1. ( C) 1996 Academic Press Limited