The role of phosphoinositide-3 kinase and PTEN in cardiovascular physiology and disease.
Phosphoinositide-3 kinases (PI3Ks) are a family of evolutionary conserved lipid kinases that mediate many cellular responses in both physiologic and pathophysiologic states. Class I PI3K can be activated by either receptor tyrosine kinase (RTK)/cytokine receptor activation (class I(A)) or G-protein-coupled receptors (GPCR) (class I(B)). Once activated PI3Ks generate phosphatidylinositols (PtdIns) (3,4,5)P(3) leading to the recruitment and activation of Akt/protein kinase B (PKB), PDK1 and monomeric G-proteins (e.g. Rac-GTPases), which then activate a range of downstream targets including glycogen synthase kinase-3beta (GSK-3beta), mammalian target of rapamycin (mTOR), p70S6 kinase, endothelial nitric oxide synthase (eNOS) and several anti-apoptotic effectors. Class I(A) (PI3Kalpha, beta and delta) and class I(B) (PI3Kgamma) PI3Ks mediate distinct phenotypes in the heart and under negative control by the 3'-lipid phosphatase, phosphatase and tensin homolog on chromosome ten (PTEN) which dephosphorylate PtdIns(3,4,5)P(3) into PtdIns(4,5)P(2). PI3Kalpha, gamma and PTEN are expressed in cardiomyocytes, fibroblasts, endothelial cells and vascular smooth muscle cells where they modulate cell survival/apoptosis, hypertrophy, contractility, metabolism and mechanotransduction. Several transgenic and knockout models support a fundamental role of PI3K/PTEN signaling in the regulation of myocardial contractility and hypertrophy. Consequently the PI3K/PTEN signaling pathways are involved in a wide variety of diseases including cardiac hypertrophy, heart failure, preconditioning and hypertension. In this review, we discuss the biochemistry and molecular biology of PI3K (class I isoforms) and PTEN and their critical role in cardiovascular physiology and diseases.
Heart and Stroke/Richard Lewar Centre of Excellence, Departments of Medicine and Physiology, University of Toronto, Room 68, 150 College Street, Fitzgerald Building, Toronto, Ont., M5S 3E2, Canada.
Gavin Y
GY
Oudit
Hui
H
Sun
Benoit-Gilles
BG
Kerfant
Michael A
MA
Crackower
Josef M
JM
Penninger
Peter H
PH
Backx
D000818:Animals; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000503:physiopathology; D002320:Cardiovascular Physiological Phenomena; D002319:Cardiovascular System / Q000201:enzymology*; D006801:Humans; D007527:Isoenzymes / Q000502:physiology; D051059:PTEN Phosphohydrolase; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D010716:Phosphatidylinositols / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010744:Phosphoric Monoester Hydrolases / Q000502:physiology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D015398:Signal Transduction; D025521:Tumor Suppressor Proteins / Q000502:physiology*
D007527:Isoenzymes; D051059:PTEN Phosphohydrolase; D019869:Phosphatidylinositol 3-Kinases; D010716:Phosphatidylinositols; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010744:Phosphoric Monoester Hydrolases; D047428:Protein Kinase Inhibitors; D025521:Tumor Suppressor Proteins; C494929:PTEN protein, human