Gene expression in activated WT or PDK4 -/- CD4+ T cells
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ABSTRACT: Activation of CD4+ T cells requires metabolic reprograming to sustain demands of cellular building blocks and ATP. Pyruvate dehydrogenase kinase (PDK) is an enzyme regulating pyruvate dehydrogenase complex subunit alpha 1 (PDHE1-alpha), which converts pyruvate to acetyl-CoA. Gene expression analysis of TCR-stimulated CD4+ T cells with PDK4 deletion exhibited the reduced calcium signaling and aerobic glycolysis pathway.
Project description:Pyruvate Dehydrogenase Kinase 4 (Pdk4) is a pyruvate dehydrogenase inhibiton gene that strongly regulates metabolism. We studied the expression of Pdk4 in the young and aged mouse heart in both healthy conditions and after ischemic insult.
Project description:Cellular senescence is a response elicited by acute or chronic damage signals. In humans, senescent cells accumulate in multiple tissues at different rates, from 2- to 20-fold when comparing young (<35 years) to old (>65 years) healthy donors. The pathogenic role of cellular senescence in diverse age-related diseases can be largely explained by the senescence-associated secretory phenotype (SASP). Senescent cells display changes in mitochondrial activity with increased ATP production and high lactate production, which are partially correlated with upregulation of pyruvate dehydrogenase kinase 4 (PDK4), an inhibitor of mitochondrial pyruvate dehydrogenase. We used a genotoxic agent, bleomycin, and/or a PDK4-targeting chemical, PDK4-IN, to treat human primary stromal cells and determined the influence of PDK4 inhibition on the transcriptomic expression profile of senescent cells. The data allow to disclose the importance of PDK4 activity in development of senescence-associated phenotypes, particularly the SASP.
Project description:Technical advances in next generation sequencing (NGS) has revolutionized system-based analysis of genome-wide expression, cellular pathways and responses. We performed this study to establish the transcriptomic profiles of human prostate cancer cell lines exposed to conditioned media from human primary stromal cells engineered to express pyruvate dehydrogenase kinase 4 (PDK4), a key enzyme that is correlated with glucose metabolism, negatively regulates the conversion of pyruvate to acetyl-CoA and plays important roles in cancer progression and multiple other pathological events.
Project description:Prostate cancer has a broad spectrum of clinical behavior, hence biomarkers are urgently needed for risk stratification. We previously described the protective effect of signal transducer and activator of transcription 3 (STAT3) in a prostate cancer mouse model. We now show the importance of STAT3-regulated metabolic functions and explain their influence on aggressive prostate cancer. By utilizing a gene co-expression network in addition to laser microdissected proteomics from human and murine FFPE samples, we established a workflow that facilitates the discovery of new biomarkers. We thereby identified the protective effect of pyruvate dehydrogenase kinase 4 (PDK4) in prostate cancer. PDK4 is a key regulator of the citrate cycle and low PDK4 is significantly associated with disease recurrence.
Project description:Cardiac metabolism plays a crucial role in producing sufficient energy to sustain cardiac contractions. However, the role of metabolism in cardiomyocyte proliferation remains unclear. Working with the adult zebrafish heart regeneration model, we first find an increase in the levels of mRNAs encoding enzymes regulating glucose and pyruvate metabolism, including pyruvate kinase M1/2 (Pkm) and pyruvate dehydrogenase kinases (Pdks), specifically in tissues bordering the damaged area. We proceed to show that impaired glycolysis decreases the number of proliferating cardiomyocytes following cardiac injury. These observations are further supported by analyses using loss-of-function models for the metabolic regulators Pkm2a and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (Ppargc1a). Cardiomyocyte-specific loss- and gain-of-function manipulations of pyruvate metabolism using Pdk3 and a catalytic subunit of the pyruvate dehydrogenase complex (PDC) reveal its importance in cardiomyocyte dedifferentiation and proliferation. Furthermore, we find that PDK activity can modulate cell cycle progression and protrusive activity in mammalian cardiomyocytes in culture. Our findings reveal new roles for cardiac metabolism and the PDK-PDC axis in cardiomyocyte behavior following cardiac injury.
Project description:Cardiac metabolism plays a crucial role in producing sufficient energy to sustain cardiac function. However, the role of metabolism in different aspects of cardiomyocyte regeneration remains unclear. Working with the adult zebrafish heart regeneration model, we first find an increase in the levels of mRNAs encoding enzymes regulating glucose and pyruvate metabolism, including pyruvate kinase M1/2 (Pkm) and pyruvate dehydrogenase kinases (Pdks), especially in tissues bordering the damaged area. We further find that impaired glycolysis decreases the number of proliferating cardiomyocytes following injury. These observations are supported by analyses using loss-of-function models for the metabolic regulators Pkma2 and peroxisome proliferator-activated receptor gamma coactivator 1 alpha. Cardiomyocyte-specific loss- and gain-of-function manipulations of pyruvate metabolism using Pdk3 as well as a catalytic subunit of the pyruvate dehydrogenase complex (PDC) reveal its importance in cardiomyocyte dedifferentiation and proliferation after injury. Furthermore, we find that PDK activity can modulate cell cycle progression and protrusive activity in mammalian cardiomyocytes in culture. Our findings reveal new roles for cardiac metabolism and the PDK-PDC axis in cardiomyocyte behavior following cardiac injury.
Project description:We identified PDK4 as a gene with adaptive transcriptional response to chemical stress. Although PDK4 is an energy resource regulator induced by starvation, expression of other fasting-inducible genes was unaffected, indicating additional physiological role of PDK4 for liver adaptation to the chemical stress. We used microarrays to determine genes with altered transcriptional level by PDK4 overexpression. Mice were infected with Ad-control (empty adenovirus vector) or Ad-PDK4 (PDK4 overexpressing adenovirus vector) at a dose of 10^9 PFU/mouse by tail vein injection. 3 days after the infection, mice were sacrificed for RNA preparation from the liver. Ad-control infected = 4, Ad-PDK4 infected = 3. Specimens from mice of each group were pooled, and 10 ug RNA from each pool was used for cRNA synthesis.
Project description:We identified PDK4 as a gene with adaptive transcriptional response to chemical stress. Although PDK4 is an energy resource regulator induced by starvation, expression of other fasting-inducible genes was unaffected, indicating additional physiological role of PDK4 for liver adaptation to the chemical stress. We used microarrays to determine genes with altered transcriptional level by PDK4 overexpression.
Project description:Metabolic reprogramming during macrophage polarization supports the effector functions of these cells in health and disease. Although the importance of glycolytic and oxidative metabolism in M1 and M2 macrophages, respectively, is well established, our knowledge of metabolic checkpoints controlling these effector states is limited. Here we demonstrate that pyruvate dehydrogenase kinase (PDK), which inhibits the conversion of cytosolic pyruvate to mitochondrial acetyl-CoA by pyruvate dehydrogenase, functions as a metabolic checkpoint in M1 macrophages. Genetic deletion or pharmacological inhibition of PDK2/4 prevents polarization of macrophages to the M1 phenotype in response to inflammatory stimuli (lipopolysaccharide plus IFN-γ). The therapeutic potential of attenuation of pro-inflammatory responses by PDK inhibition was tested, both genetically and pharmacologically, in obesity-induced insulin resistance, a disease process in which M1 macrophages contribute to adipose tissue inflammation and insulin resistance. Taken together, these studies identify PDK2/4 as a metabolic checkpoint for M1 phenotype polarization of macrophages.
Project description:Using the highly sensitive miRNA array, we screened out different microRNAs regulated by different concertration of dichloroacetate for different time. Among them 119 microRNAs were obvious Metabolic abnormality is one of the hallmarks of cancer and has been shown to be involved in chemoresistance. In this context, targeting the abnormal metabolism of cancer cells has been an intense avenue of research aiming at asphyxiating the tumor . DCA inhibits the enzymatic activity of Pyruvate Dehydrogenase Kinases (PDK 1 to 4), which are enzymes critical for the activation of the pyruvate dehydrogenase necessary to transform pyruvate into acetyl-CoA, linking the glycolytic metabolism to the citric acid cycle. DCA is primarily used to treat lactic acidosis and hereditary mitochondrial disease, which has been also reported to have anti-cancer effect . However, the mechanism underlying the effect of DCA on CRC treatment remain unsettled. Multiple and complex mechanisms have been described that control the metabolic shift in cancer cells, including microRNAs (miRNAs). MicroRNAs represents a class of small endogenous noncoding RNAs that regulate translation and degradation of mRNAs. Besides controlling the metabolism, miRNAs participate in many more biological processes including cell proliferation, migration, apoptosis , self-renewal, initiation and development of cancers, and chemoresistance.Here we explore the molecular mechanism involved in regulating glucose metabolism and associated chemotherapy resistance in CRC. By exploiting DCA, pyruvate dehydrogenase kinase (PDK) inhibitor, in CRC cells, trying to elucidate the roles of related miRNAs and thereby outlining a signaling pathway.