Loss of PI3Kγ results in massive myocardial ischemia/reperfusion induced heart damage.

<p>(<b>A</b>) Following M I/R injury, serum TroponinT is significantly increased in PI3Kγ^−/− (KO) mice compared to wild type (WT) controls. Data are from 3 hours after reperfusion. n = 13 per group. (<b>B</b>) No significant difference in the numbers of inflammatory cells in the injured hearts of PI3Kγ^−/− and WT mice. Inflammatory cell infiltrates were assessed 3 hours after reperfusion. n = 7 per group. (<b>C</b>) No significant difference in the area at risk (AAR)/left ventricle (LV) in PI3Kγ^−/− and WT mice. (<b>D</b>) PI3Kγ KO mice display a markedly increased area of infarction/area at risk (AAR) 24 hours after reperfusion. n = 6 per group for (<b>C</b>) and (<b>D</b>). (<b>E</b>) Representative left ventricular TTC-stained sections from the basis (left) to the apex (right) of wild type (WT; upper panels) and PI3Kγ^−/− (KO; lower panels) hearts after 24 hours of reperfusion. Pale areas represent necrotic regions (arrows). Bars indicate 1 mm. In all bar graphs mean values +/− SEM are shown. *p<0.05. **p<0.01. NS = not significant.</p

PI3Kγ^−/− lipid kinase activity is not required for cardioprotection.

<p>(<b>A</b>) TroponinT levels measured after 30 minutes of ischemia and 3 hours of reperfusion are comparable between PI3Kγ^KD/KD (KD) and control wild type (WT) mice. In total PI3Kγ knock-out (KO) mice TroponinT levels are significantly increased (*p<0.05). n = 13 for WT and KO, n = 11 for KD mice. (<b>B</b>) No significant difference in the area at risk (AAR)/left ventricle (LV) in PI3Kγ^−/− (KO), PI3Kγ^KD/KD (KD), and control WT mice. Data are at 24 hours after M/I injury. (<b>C</b>) PI3Kγ KO, but not PI3Kγ^KD/KD (KD) mice display a markedly increased area of infarction/area at risk (AAR) 24 hours after reperfusion evaluated by TTCstaining. n = 6 per group. *p<0.05. NS = not significant. (<b>D</b>) Representative left ventricular Trichrome-stained sections from the basis (left) to the apex (right) of hearts from wild type (WT), PI3Kγ^KD/KD knock-in (KD), and PI3Kγ^−/− (KO) mice challenged with 30 minutes of ischemia plus 1 week of reperfusion. Arrows represent infarcted regions. Bars indicate 1 mm. (<b>E</b>) PI3Kγ^KD/KD (KD) mice display similar infarctions/left ventricle (LV) compared to wild type controls after 30 minutes of ischemia and 1 week of reperfusion. Data from PI3Kγ^−/− (KO) are also shown. n = 6 per group. (<b>F</b>) PI3Kγ^−/− (KO), but not PI3Kγ^KD/KD knock-in (KD) mice exhibit a significant greater impairment in percentage fractional shortening (FS) relative to WT controls after 30 minutes of ischemia and 1 week of reperfusion. n = 6 per group. Note that the data are calculated to baseline FS of the respective genotype. All bar graphs show mean values +/− SEM. *p<0.05. (<b>G</b>) Representative M-mode echocardiography of wild type (WT), PI3Kγ^KD/KD knock-in (KD), and PI3Kγ^−/− (KO) mice one week after M I/R injury. Note, that baseline contractility is enhanced in PI3Kγ^−/− (KO), but not PI3Kγ^KD/KD knock-in (KD) mice as reported previously <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0009350#pone.0009350-Crackower1" target="_blank">[11]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0009350#pone.0009350-Patrucco1" target="_blank">[12]</a>. Bars indicate 50 ms (horizontal) and 1 mm (vertical).</p

Loss of PI3Kγ results in long term myocardial ischemia/reperfusion induced heart damage.

<p>(<b>A</b>) Areas of infarction (arrows) in representative left mid-ventricular sections 1 week after M I/R injury. (H&E staining). Bars indicate 1 mm. (<b>B</b>) PI3Kγ^−/− (KO) hearts show a markedly greater infarction size in the left ventricle (LV) at 1 week after M I/R. n = 7 per group. (<b>C</b>) No significant difference between PI3Kγ^−/− and WT mice in the numbers of infiltrating inflammatory cells 1 week after M I/R. n = 7 per group. (<b>D</b>) Representative left mid-ventricular sections stained with Trichrome and Aniline blue to visualize collagen deposits (arrows) in hearts of PI3Kγ^−/− (KO) and wild type (WT) mice 3 weeks after M I/R. Magnifications ×20. (<b>E</b>) Markedly increased scar tissue in PI3Kγ^−/− 3 weeks after M I/R injury. n = 7 per group. (<b>F</b>) PI3Kγ^−/− mice exhibit a significant greater loss in percentage fractional shortening (FS) relative to their respective baseline FS after 3 weeks of M I/R compared to WT controls. n = 9 per group. In all bar graphs mean values +/− SEM are shown. *p<0.05. NS = not significant.</p

PI3Kγ functions in non-haematopoietic cells in myocardial ischemia/reperfusion injury.

<p>(<b>A</b>) Representative left mid-ventricular histological sections (H&E staining) from WT mice receiving WT bone marrow (WT→WT) and WT mice receiving PI3Kγ^−/− bone marrow (KO→WT). Hearts were isolated and analysed from mice 1 week after M I/R injury. Arrows indicate areas of infarction. (<b>B</b>) Representative left mid-ventricular histological sections (H&E staining) from PI3Kγ^−/− mice receiving WT bone marrow (WT→KO) and PI3Kγ^−/− mice receiving PI3Kγ^−/− bone marrow (KO→KO) after 1 week of M I/R injury. Arrows point at areas of infarction. (<b>C</b>) No significant difference between WT→WT and KO→WT chimeras and no difference between WT→KO and KO→KO chimeras in the size of infarction determined 1 week after M I/R injury. n = 5 per group. (<b>D</b>) No significant difference between WT→WT and KO→WT chimeras and no difference between WT→KO and KO→KO chimeras in TroponinT levels assayed 3 hours after reperfusion. n = 7 per group. (<b>E</b>) No significant difference between all 4 groups of chimeric mice in the numbers of infiltrating inflammatory cells 1 week after M I/R. n = 5 per group. In all histological pictures the bar indicates 1 mm. All bar graphs show mean values +/− SEM. *p<0.05. NS = no significant difference.</p