VDAC1 and heart failure: However, contrarily to these results, other studies propose heart failure to be associated with a reduced ER–mitochondria coupling: in diabetes type 2, where a reduced Ca2+ shuttling in MAM regions was repeatedly demonstrated for many tissues [115,116,117], a reduction in IP3R-VDAC1 interaction and, thus, a decrease in IP3 stimulated Ca2+ transfer to mitochondria was observed for cardiomyocytes.