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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, RESULTS. Meshes: Actins, Adult, Cell Survival, Cyclooxygenase 2, Enzyme Activation, Female, Glycogen Synthase Kinase 3, Heart Failure, Heart Ventricles, Heart-Assist Devices, Humans, Insulin Receptor Substrate Proteins, Isoenzymes, Male, Membrane Proteins, Middle Aged, Myocytes, Cardiac, Phosphoproteins, Prostaglandin-Endoperoxide Synthases, Protein-Serine-Threonine Kinases, Proto-Oncogene Proteins, Proto-Oncogene Proteins c-akt, Receptor, IGF Type 1, Transcription, Genetic.
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Does mechanical unloading of the failing human heart fail to activate the protein kinase B/Akt/glycogen synthase kinase-3beta survival pathway? Context: Left ventricular assist device (LVAD) support of the failing human heart improves myocyte function and increases cell survival. One potential mechanism underlying this phenomenon is activation of the protein kinase B (PKB)/Akt/glycogen synthase kinase-3beta (GSK-3beta) survival pathway. Left ventricular tissue was obtained both at the time of implantation and explantation of the LVAD (n = 11). Six patients were diagnosed with idiopathic dilated cardiomyopathy, 4 patients with ischemic cardiomyopathy and 1 patient with peripartum cardiomyopathy. The mean duration of LVAD support was 205 +/- 35 days. Myocyte diameter and phosphorylation of ERK were used as indices for reverse remodeling. Transcript levels of genes required for the activation of PKB/Akt (insulin-like growth factor-1, insulin receptor substrate-1) were measured by quantitative RT-PCR. In addition, we measured the relative activity of PKB/Akt and GSK-3beta, and assayed for molecular and histological indices of PKB/Akt activation (cyclooxygenase mRNA levels and glycogen levels). Myocyte diameter and phosphorylation of ERK decreased with LVAD support. In contrast, none of the components of the PKB/Akt/GSK-3beta pathway changed significantly with mechanical unloading.
assistant
The PKB/Akt/GSK-3beta pathway is not activated during LVAD support. Other signaling pathways must be responsible for the improvement of cellular function and cell survival during LVAD support. Final Decision: yes