When one says yes and the other says no; does calcineurin participate in physiologic cardiac hypertrophy?

Abstract

Developing engaging activities that build skills for understanding and appreciating research is important for undergraduate and postgraduate science students. Comparing and contrasting opposing research studies does this, and more: it also appropriately for these cohortschallenges higher level cognitive processing. Here, we present and discuss one such scenario, that of calcineurin in the heart and itsresponse to exercise training. This scenario is further accentuated by the existence of only two studies. The background is that regularaerobic endurance exercise training stimulates the heart to physiologically adapt to chronically increase its ability to produce a greatercardiac output to meet the increased demand for oxygenated blood in working muscles, and this happens by two main mechanisms: 1)increased cardiac contractile function and 2) physiologic hypertrophy. The major underlying mechanisms have been delineated over thelast decades, but one aspect has not been resolved: the potential role of calcineurin in modulating physiologic hypertrophy. This is partlybecause the existing research has provided opposing and contrasting findings, one line showing that exercise training does activate cardiaccalcineurin in conjunction with myocardial hypertrophy, but another line showing that exercise training does not activate cardiac calcineurineven if myocardial hypertrophy is blatantly occurring. Here, we review and present the current evidence in the field and discussreasons for this controversy. We present real-life examples from physiology research and discuss how this may enhance studentengagement and participation, widen the scope of learning, and thereby also further facilitate higher level cognitive processing