Author/Authors :
Michael A. Crackower، نويسنده , , Gavin Y. Oudit، نويسنده , , Ivona Kozieradzki، نويسنده , , Renu Sarao، نويسنده , , Hui Sun، نويسنده , , Takehiko Sasaki، نويسنده , , Emilio Hirsch، نويسنده , , Akira Suzuki، نويسنده , , Tetsuo Shioi، نويسنده , , Junko Irie-Sasaki، نويسنده , , Rajan Sah، نويسنده , , Hai-Ying M. Cheng، نويسنده , , Vitalyi O. Rybin، نويسنده , , Giuseppe Lembo، نويسنده , , Luigi Fratta، نويسنده , , Antonio J. Oliveira-dos-Santos، نويسنده , , Jeffery L. Benovic، نويسنده , , C Ronald Kahn، نويسنده , , Seigo Izumo، نويسنده , , Susan F. Steinberg، نويسنده , , et al.، نويسنده ,
Abstract :
The PTEN/PI3K signaling pathway regulates a vast array of fundamental cellular responses. We show that cardiomyocyte-specific inactivation of tumor suppressor PTEN results in hypertrophy, and unexpectedly, a dramatic decrease in cardiac contractility. Analysis of double-mutant mice revealed that the cardiac hypertrophy and the contractility defects could be genetically uncoupled. PI3Kα mediates the alteration in cell size while PI3Kγ acts as a negative regulator of cardiac contractility. Mechanistically, PI3Kγ inhibits cAMP production and hypercontractility can be reverted by blocking cAMP function. These data show that PTEN has an important in vivo role in cardiomyocyte hypertrophy and GPCR signaling and identify a function for the PTEN-PI3Kγ pathway in the modulation of heart muscle contractility.
