Project description:AMP-activated protein 1 kinase (AMPK), a phylogenetically conserved serine/threonine kinase regarded as a key cellular energy sensor, exists in eukaryotes as a heterotrimer comprising a catalytic α and regulatory β and γ subunits. In humans, activating mutations in the gene encoding the γ2 subunit of AMPK (PRKAG2) display a cardiac phenotype of left ventricular hypertrophy (LVH), conduction system disease, ventricular pre-excitation and increased cardiomyocyte glycogen accumulation. While existing transgenic models have elucidated the pathogenesis of several aspects of the disease5-7, the slow heart rate (sinus bradycardia) – a prominent feature of the disease – remains poorly understood. Here, using gene-targeting to generate mice which recapitulate this bradycardia, we demonstrate that γ2 AMPK activation perturbs fundamental mechanisms that determine sinoatrial pacemaker cell function. Reduction in the sarcolemmal hyperpolarization activated (“funny”) current (If) and damping of ryanodine receptor-derived diastolic local subsarcolemmal Ca2+ releases (LCRs)12,13 contribute to reduced sinoatrial cell spontaneous activity and, ultimately, to a lower heart rate. Pharmacological activation of AMPK reversibly reduces the beating rate of murine pluripotent stem cell-derived induced sinoatrial bodies. In contrast, using a mouse knock-out of γ2 AMPK, which exhibits an increased heart rate, we demonstrate a role for γ2 AMPK in physiological heart rate regulation, including an indispensable role in the bradycardic adaptation to endurance exercise. Through regulating the cardiac pacemaker and thereby heart rate, γ2 AMPK by virtue of its energy-sensing role, is a key physiological determinant of overall cardiac energy homeostasis.
Project description:Despite significant advances in our understanding of the biology determining systemic energy homeostasis, the treatment of obesity remains a medical challenge. Activation of AMP-activated protein kinase (AMPK) has been proposed as an attractive strategy for the treatment of obesity and its complications. AMPK is a conserved, ubiquitously expressed, heterotrimeric serine/threonine kinase whose short-term activation has multiple beneficial metabolic effects. Whether these translate into long-term benefits for obesity and its complications is unknown. Here, we observe that mice with chronic AMPK activation, resulting from mutation of the AMPK γ2 subunit, exhibit ghrelin signalling-dependent hyperphagia, obesity and impaired pancreatic islet insulin secretion. Humans bearing the homologous mutation manifest a congruent phenotype. Our studies highlight that long-term AMPK activation can have adverse metabolic consequences with implications for pharmacological strategies seeking to chronically activate AMPK systemically to treat metabolic disease.
Project description:This research trial is testing a combination of two experimental drugs, MSC1936369B (Mitogen-activated protein extracellular signal-regulated kinase (MEK) Inhibitor) and SAR245409 (Phosphatidylinositol 3-kinase (Pi3K)/Mammalian Target of Rapamycin (mTOR) inhibitor), in the treatment of locally advanced or metastatic solid tumors. The primary purpose of the study is to determine the maximum tolerated dose of the drug combination.
Project description:The conserved Snf1/AMPK (AMP-activated protein Kinase) family is one of the central components in nutrient sensing and regulation of carbon metabolism in eukaryotes. It is also involved in several other processes such as stress resistance, invasive growth and ageing. Snf1 kinase is composed of a catalytic alpha-subunit Snf1, a regulatory gamma-subunit Snf4 and one of three possible beta-subunits, Sip1, Sip2 or Gal83. We used a systematic approach to study the role of the three beta-subunits by analyzing all 7 possible combinations of beta-subunit deletions together with the reference strain.
Project description:To explore the function of AMPK signaling in acute myeloid leukemia (AML), we used shRNA to knock down the expression of PRKAA1, the catalytic subunit of the 5'-prime-AMP-activated protein kinase (AMPK), in primary human AML cells and performed RNA-seq experiment to profile transcriptional changes upon AMPK inactivation.
Project description:The conserved Snf1/AMPK (AMP-activated protein Kinase) family is one of the central components in nutrient sensing and regulation of carbon metabolism in eukaryotes. It is also involved in several other processes such as stress resistance, invasive growth and ageing. Snf1 kinase is composed of a catalytic α-subunit Snf1, a regulatory γ-subunit Snf4 and one of three possible β-subunits, Sip1, Sip2 or Gal83. We used a systematic approach to study the role of the three β-subunits by analyzing all 7 possible combinations of β-subunit deletions together with the reference strain.
Project description:Conducted serum untargeted metabolomics analysis in AMP-activated protein kinase (AMPK) intestinal KO mice and control mice under high-fat diet (HFD) conditions