Epidemiological and histological findings implicate matrix Gla protein in diastolic left ventricular dysfunction
Rows are labelled by the MGP conformation (red) stained for: from top to bottom uncarboxylated MGP (ucMGP), carboxylated MGP (cMGP), unphosphorylated MGP (dpMGP) and phosphorylated MGP (pMGP). pMGP and cMGP include the secreted and active MGP conformation. Columns refer to exemplary tissue samples of male patients aged 61–63 years: from left to right unused donor heart (.h [HD]), dilated cardiomyopathy (.d [DCM] and ischemic cardiomyopathy representative section (.i [ICM]) and fibrotic area of the same ischemic heart (.f). WGA (green) and TO-PRO3 (blue) stain cell membranes and nuclei, respectively. The dilution of the conformation specific antibodies was 1:100 for ucMGP, dpMGP, pMGP and the inset in panel B.co and 1:250 for cMGP. The scale bar corresponds to 25 μm. The findings are described in a qualitative way in the results section. The quantitative analysis, comparing abundance of ucMGP and pMGP among HD, DCM and ICM appear in panels E and F, respectively. n refers to the number of tissue samples included in the quantitative analysis. Labels: asterisks indicate cardiomyocytes; arrows point to interstitial cells with perinuclear MGP deposition; L lumen of muscularized microvessels.