Myotrophin/V-1 does not act as an extracellular signal to induce myocyte hypertrophy.

ABSTRACT: The myotrophin/V-1 protein was originally found to be elevated in failing heart tissues and was described as an exogenously acting hypertrophy-inducing factor. However, several studies have proposed only intracellular functions for this protein. We investigated whether this protein is an exogenously acting hypertrophy-inducing trophin or an intracellular nuclear factor of kappa B (NFkappaB) regulatory protein. In the current report, immunofluorescence and cell fractionation studies showed that myotrophin is present only in the cytoplasm and is not actively released into the extracellular environment in response to hypertrophy-inducing stimuli. Moreover, in response to ischemia/reperfusion injury, an active release of myotrophin from adult rat myocardium was not observed. Furthermore, prote

SUBMITTER: Knuefermann P 

PROVIDER: S-EPMC1592290 | biostudies-literature | 2006

REPOSITORIES: biostudies-literature