Figure 1. Loss of Kindlin-2 in the heart results in postnatal lethality.

(A) Western blot and (B) corresponding quantitative densitometric analysis of Kindlin-2 in control (Ctrl) and Kindlin-2^f/f; β-MHC Cre knockout (cKO) mouse hearts at postnatal day (P) 0, 7 and 14. GAPDH served as a loading control. Kindlin-2 pixel density is normalized to the level of GAPDH (*P<0.05, two-tailed Student’s t-test). A representative example of at least two independent experiments is shown (n=2 per genotype/experiment). (C) Kaplan-Meier survival curves of male (top) and female (bottom) Ctrl and cKO mice. Male and female cKO mice die between 42–55 and 45–52 weeks, respectively. (D) Macroscopic cross-sectional views of Hematoxylin and Eosin- and Masson’s Trichrome-stained hearts isolated from Ctrl and cKO mice, at 7 and 13 months (scale bar: 2 mm). Representative high magnification views are shown below each corresponding whole heart section (scale bar: 100 µm) (n=2–3 per genotype). (E) Heart weight to body weight ratio (HW/BW) of Ctrl versus cKO mice at 7 and 13 months (M) (***P<0.001, two-tailed Student’s t-test). (F) qRT-PCR analysis of indicated genes in Ctrl and cKO mouse hearts, at 7 (left) and 13 (right) months. Data is normalized to corresponding 18S levels, and cKO is expressed as fold change versus Ctrl (*P<0.05; **P<0.01, two-tailed Student’s t-test). Col1α1, collagen alpha 1 type I; Col3α1, collagen alpha1 type III; ANF, atrial natriuretic factor; BNP, B-type natriuretic peptide.