Induction of cellular apoptosis in h9c2 cells by tissue factor

Abstract

Cardiac hypertrophy is the adaptive response of the heart to chronic mechanical overload and an important risk factor in the development of heart failure. Increased cell death resulting from both apoptosis and necrosis is a characteristic of cardiac hypertrophy. During the onset of cardiac hypertrophy, tissue factor (TF), the main initiator of blood coagulation, is shown to be up-regulated in the myocardium. TF is a strong marker and putative modulator of cellular events in apoptosis. In the present study, we investigated the involvement of TF in the programmed cell death of H9c2 cardiomyocytic cell line. H9c2 cardiomyocytes were cultured in serum-free conditions and treated with a range of concentrations of human recombinant TF (0.05–2 μM) over a period of 10 days. The proliferation of the cells was assessed by an MTT assay and the onset of apoptosis measured by caspase-3 activation using flow cytometry. Treatment of H9c2 cells over the period of the investigation resulted in a progressive decrease in the H9c2 proliferation (down to 20% of the control). Caspase-3 activity was increased above 12% of the control over the period of the investigation. We propose that chronic elevation in circulating TF, as a result of infection or vascular inflammation, can lead to myocyte depletion, ultimately leading to cardiac hypertrophy.