MK5 haplodeficiency decreases collagen deposition and scar size during post-myocardial infarction wound repair.

MK5 haplodeficiency decreases collagen deposition and scar size during post-myocardial infarction wound repair. Am J Physiol Heart Circ Physiol. 2019 Mar 22;: Authors: Nawaito S, Sahadevan P, Clavet-Lanthier MÉ, Pouliot P, Sahmi F, Shi Y, Gillis MA, Lesage F, Gaestel M, Sirois MG, Calderone A, Tardif JC, Allen BG Abstract MK5 is a protein serine/threonine kinase activated by p38, ERK3, and ERK4 MAPKs. MK5 mRNA and immunoreactivity are detected in mouse cardiac fibroblasts and MK5-haplodeficiency attenuates the increase in collagen 1-a1 mRNA evoked by pressure overload. The present study examined the effect of MK5 haplodeficiency on reparative fibrosis following myocardial infarction (MI). Twelve-week-old MK5+/- and wild-type littermate (MK5+/+) mice underwent ligation of the left anterior descending coronary artery (LADL). Surviving mice were sacrificed 8- or 21-days post-MI. Survival rates did not differ significantly between MK5+/+ and MK5+/- mice, with rupture of the LV wall being the primary cause of death. Echocardiographic imaging revealed similar increases in LV end-diastolic diameter, myocardial performance index, and wall motion score index in LADL-MK5+/+ and LADL-MK5+/- mice. Area at risk did not differ between LADL-MK5+/+ and LADL-MK5+/- hearts. In contrast, infarct size, scar area, and scar collagen content were reduced in LADL-MK5+/- hearts. Immunohistochemical analysis of mice experiencing heart rupture revealed increa...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Tags: Am J Physiol Heart Circ Physiol Source Type: research