Mast cells in chronic pressure overload induced right ventricular hypertrophy

Objective:

Although mast cell functions have classically been related to allergic and non-allergic immune responses, a rapidly growing body of evidence has implicated these cells in a large variety of pathophysiologic processes. However, the role of mast cells in the development of right ventricular (RV) hypertrophy is not known.

Results:

In a murine model of pulmonary artery banding, RV remodeling was characterized by dilatation and increased chamber and cardiomyocyte hypertrophy, enhanced collagen deposition, and significant increase in the mRNA expression of myocardial hypertrophy marker genes. The RV remodeling process in banded mice was associated with a significant deterioration of RV function, increased filling pressures, and decreased cardiac output. In addition, we found time-dependant increase in mast cell density and degranulation in RVs of banded mice, which was associated with upregulation of mast cell-specific genes in banded mice.

Conclusion:

Taken together, our preliminary data suggest possible involvement of mast cells in the RV remodeling in response to pressure overload.