AIMS: Activation of phosphoinositide-3 kinase (PI3K) is essential for cell growth, relating to adaptive and maladaptive cardiac hypertrophy. This longitudinal canine study was designed to investigate the role of PI3Kalpha and PI3Kgamma in cardiac remodelling during congestive heart failure (CHF) and cardiac recovery (CR). METHODS AND RESULTS: All dogs were surgically instrumented. Congestive heart failure was induced by cardiac pacing for 3-4 weeks and CR was allowed by terminating pacing for 5-6 weeks after induction of HF. Control dogs had sham surgery, but did not undergo pacing. Left ventricular (LV) contractile function was depressed in CHF and restored to 80-90% of the normal level in CR, with a 25% increase in LV weight. The expression of PI3Kgamma was increased four-fold in CHF, but returned to control levels in CR. In contrast, the expression of PI3Kalpha in CHF was not different from that in controls, but increased three-fold in CR and was accompanied by increases in phosphorylation of Akt (five-fold), GSK-3beta (five-fold), beta-catenin (three-fold), mTOR (two-fold), and P70S6K (two-fold). CONCLUSION: Our results indicate that PI3K isoforms are regulated differently during the course of CHF/CR and that the selective activation of PI3Kalpha, through Akt, GSK-3beta, and mTOR signalling pathways, may be involved in the development of cardiac compensatory hypertrophy and functional restoration.
AIMS: Activation of phosphoinositide-3 kinase (PI3K) is essential for cell growth, relating to adaptive and maladaptive cardiac hypertrophy. This longitudinal canine study was designed to investigate the role of PI3Kalpha and PI3Kgamma in cardiac remodelling during congestive heart failure (CHF) and cardiac recovery (CR). METHODS AND RESULTS: All dogs were surgically instrumented. Congestive heart failure was induced by cardiac pacing for 3-4 weeks and CR was allowed by terminating pacing for 5-6 weeks after induction of HF. Control dogs had sham surgery, but did not undergo pacing. Left ventricular (LV) contractile function was depressed in CHF and restored to 80-90% of the normal level in CR, with a 25% increase in LV weight. The expression of PI3Kgamma was increased four-fold in CHF, but returned to control levels in CR. In contrast, the expression of PI3Kalpha in CHF was not different from that in controls, but increased three-fold in CR and was accompanied by increases in phosphorylation of Akt (five-fold), GSK-3beta (five-fold), beta-catenin (three-fold), mTOR (two-fold), and P70S6K (two-fold). CONCLUSION: Our results indicate that PI3K isoforms are regulated differently during the course of CHF/CR and that the selective activation of PI3Kalpha, through Akt, GSK-3beta, and mTOR signalling pathways, may be involved in the development of cardiac compensatory hypertrophy and functional restoration.
Authors: Meng Du; Kun Huang; Lu Gao; Liu Yang; Wen-Shuo Wang; Bo Wang; Kai Huang; Dan Huang Journal: J Huazhong Univ Sci Technolog Med Sci Date: 2013-12-13
Authors: Young Rae Ji; Myoung Ok Kim; Sung Hyun Kim; Dong Hun Yu; Mi Jung Shin; Hei Jung Kim; Hyung Soo Yuh; Ki Beom Bae; Jae Young Kim; Hum Dai Park; Sang Gyu Lee; Byung Hwa Hyun; Zae Young Ryoo Journal: J Biol Chem Date: 2010-06-18 Impact factor: 5.157
Authors: Yan Bai; Eric E Morgan; David R Giovannucci; Sandrine V Pierre; Kenneth D Philipson; Amir Askari; Lijun Liu Journal: Am J Physiol Heart Circ Physiol Date: 2012-11-30 Impact factor: 4.733
Authors: Sébastien Foulquier; Evangelos P Daskalopoulos; Gentian Lluri; Kevin C M Hermans; Arjun Deb; W Matthijs Blankesteijn Journal: Pharmacol Rev Date: 2018-01 Impact factor: 25.468
Authors: Wenbin Liang; Gavin Y Oudit; Mikin M Patel; Ajay M Shah; James R Woodgett; Robert G Tsushima; Michael E Ward; Peter H Backx Journal: Hypertension Date: 2010-08-09 Impact factor: 10.190