Fig. 6
Adult deletion of fibroblast Mcu exacerbates cardiac dysfunction, fibrosis, and myofibroblast formation post-MI and chronic angiotensin II administration. a Mcufl/fl mice were crossed with mice expressing a tamoxifen (tamox)-inducible, fibroblast-specific Cre recombinase (Col1a2-CreERT). Tamox administration (40 mg/kg/day) for 10 days induces fibroblast-restricted Cre expression. b Adult cardiac fibroblasts were isolated post-tamox treatment and immunoblotted for MCU expression. CIII (Complex III, subunit-UQCRC2) was used as a loading control. c Experimental timeline: 8–12-week-old mice were treated with tamox and allowed to rest before permanent ligation of the left coronary artery. d–f Cardiac function was analyzed by echocardiography 1 week prior to MI and every week thereafter. M-mode echo measurements of left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), and percent fractional shortening (FS). n = 10 Col1a2-Cre, n = 20 Mcufl/fl × Col1a2-Cre. g Ratio of heart weight to tibia length 4 weeks post-MI. Sham: n = 5 Col1a2-Cre, n = 7 Mcufl/fl × Col1a2-Cre; post-MI: n = 10 Col1a2-Cre, n = 20 Mcufl/fl × Col1a2-Cre. h Quantification of wet–dry lung weight as a measurement of lung edema 4 weeks post-MI. n = 10 Col1a2-Cre, n = 20 Mcufl/fl × Col1a2-Cre. i, j LV sections were stained with Masson’s trichrome (MTc). Representative images are shown. Percent fibrotic area per infarct border and remote zones. n = 4 mice per group, multiple non-consecutive heart sections were quantified per mouse. k Percent change in myofibroblast number (α-SMA+/CD31−) in the remote zone 4 weeks post-MI. n = 4 Col1a2-Cre, n = 8 Mcufl/fl × Col1a2-Cre; multiple non-consecutive heart sections in the remote zone were quantified per mouse. l Experimental timeline: mini-osmotic pumps were subcutaneously implanted in mice to deliver AngII for 4 weeks. m, n Representative images of MTc stained LV sections. Percent fibrosis per area was quantified. n = 5 Col1a2-Cre, n = 4 Mcufl/fl × Col1a2-Cre; multiple non-consecutive heart sections were quantified per mouse. o Percent change in myofibroblast number (α-SMA+/CD31−) 4 weeks post-AngII infusion. Sham: n = 3; AngII: n = 4; multiple non-consecutive heart sections were quantified per mouse. All data shown as mean ± SEM, ***p < 0.001, **p < 0.01, *p < 0.05 vs. control (week 0 or sham) analyzed by ANOVA. ###p < 0.001, ##p < 0.01, #p < 0.05 vs. Ad-βgal analyzed by t-test. Scale bar = 250 μm. Also see Supplementary Fig. 7 and Supplementary Table 2
