Growth factors and adaptation of myocardium to hypoxia

Abstract

The article reviews current data on the regulation of induction of growth factors, mediated by transcription factor HIF, as well as on common or specific effects and mechanisms of growth factor action in the myocardium. Our investigations of expression of HIF-1a and HIF-3a subunits, growth factors IGF-1 and bFGF, HSP70 and HSP60 chaperones in the myocardium of rats under the influence of chronic hypobaric hypoxia, and hypoxic preconditioning suggest a careful regulation of amount of these proteins and term of their action in each heart ventricle, depending on the its load, to achieve adaptation. The induction of IGF-1 in the myocardium following hypoxic preconditioning is delayed and transient, dominated by the right ventricle on day 3, and is accompanied by induction of protein-synergist HSP60. Myocardial adaptation to chronic hypoxia and hypoxic cardiac remodeling are accompanied by a significant increase in the ratio of mRNA expression HIF-3a/HIF-1a, which limits the function of the latter, a reduction of IGF-1 — mediated metabolic and tissue rebuilding, and intensified expression of chaperones.