Background- Cardiomyocytes apoptosis has a significant role in functional abnormalities in heart failure. Colchicine, a microtubule depolymerizing agent, has been shown in previous studies to reverse contractility abnormalities, and to prevent apoptosis following exposure to pro-apoptotic agents such as TNF- α. Our aim was to examine the effect of colchicine in a cell line model simulating myocardial infarction.
Methods- In the first set of experiments, murine cardiomyocyte cell line, HL-1, as well as rat myoblast cell line, H9C2 , were incubated with media containing 5% sera from rats that had a surgically induced myocardial infarction (lasting 3 or 30 days) or with 5% sera from sham-operated controls. Later, colchicine (1μM) was added for one hour and then recovery with full media containing 10% FBS was allowed for 16 hours. In the second set of experiments, we exposed HL1/H9C2 cells to hypoxic/anoxic/normoxic conditions with or without colchicine.
In both sets of experiments, annexin-FITC-propidium iodide assay was used to assess cellular viability using FACS analysis.
Results- 1. Sera effect:
HL-1 cells: Cellular viability was similar when incubated with MI (3 or 30 days)-derived sera or with sham sera (p=0.6). Adding colchocine did not significantly change the viability.
H9C2 cells: Addition of colchicine to sera derived from post MI animals (3 or 30 days) resulted in a significant 15% decrease of cellular viability compared to the same sera in the absence of colchicine.
2. Effect of oxygen deprivation:
Adding colchicine to H9C2 cells exposed to anoxic/ hypoxic environment resulted in a significant decrease in viability, though; to a lesser extent in comparison to adding colchicine to H9C2 cells exposed to normoxic environment.
Conclusions- Colchicine reduced cellular viability of cardiomyoblasts (H9C2) but not of cardiomyocytes (HL-1). In any case, we did not observe any salvage effect of colchicine on cellular viability, as previously suggested by others.
