Project description:To elucidate the mechanism of enarodustat pretreatment-induced protection against oxygen-glucose deprivation (OGD), we have we have employed whole genome microarray expression profiling as a discovery platform to identify genes upregulated by enarodustat exposure. HK2 cells were pretreated with either vehicle (DMSO) or enarodustat for 24 hours prior to OGD for 16 hours. Pathway analysis revealed upregulated glysolysis pathway.
Project description:Oxygen-glucose deprivation (OGD) is a cellular phenomenon consistently observed upon occurrence of ischemic stroke which eventually results in neuronal death. Neuronal cell death after ischemia takes place via two distinct processes, necrosis and apoptosis. Apoptosis, programmed cell death, is denoted by chromatin condensation, nuclear blebbing, cellular shrinkage, and DNA fragmentation. Unlike apoptosis, cellular swelling and lysis is suggestive of necrosis. However, these two processes are related not only to the severity but also to the duration of ischemia. Microarray analysis was carried out using 20 Illumina mouse Ref8V1.1 genechip arrays. The assignment of the arrays was as follows: Controls (n=5); exposure to OGD for 10min, 5h, 8h, 15h and 24 h (n=3 respectively).
Project description:Abnormal tumor vessels promote metastasis and impair chemotherapy. Hence, tumor vessel normalization (TVN) by targeting endothelial cells (ECs) is emerging as anti-cancer treatment. Here, we show that tumor ECs (TECs) have a hyper-glycolytic metabolism, shunting glycolytic intermediates to nucleotide synthesis. EC haplo-deficiency or blockade of the glycolytic activator PFKFB3 did not affect tumor growth, but reduced cancer cell intra- and extravasation and metastasis by normalizing tumor vessels, which improved vessel maturation and perfusion. Mechanistically, PFKFB3 inhibition tightened the vascular barrier by reducing VE-cadherin endocytosis in ECs and rendering glycolytic pericytes more quiescent; it also lowered the expression of cancer cell adhesion molecules in ECs. Additionally, PFKFB3-blockade treatment improved chemotherapy. Considering TEC metabolism for anti-cancer treatment might thus merit further attention.
Project description:The non-receptor tyrosine kinase SRC is upregulated in various human cancers and plays crucial roles in cancer progression by promoting invasion and metastasis. We show that the transforming growth factor beta (TGF-β/SMAD pathway directly upregulates SRC during the epithelial-mesenchymal transition. In human epithelial MCF10A cells, TGF-β1 treatment markedly upregulated mRNA expression of SRC. Knockout of SMAD4 suppressed upregulation of SRC by TGF-β1. ChIP-sequencing analysis revealed that SRC was transcribed from the SRC1A promoter, which interacted with SMAD2 and SMAD4, in response to TGF-β1. These findings demonstrate that a direct interaction of the activated SMAD complex with the SRC1A promoter directly upregulates SRC and suggest that TGF-β contributes to SRC upregulation in the tumor microenvironment, where TGF-β-mediated tumor progression takes place.
Project description:Upon antigen stimulation, the bioenergetic demands of T cells increase dramatically over the resting state. Although a role for the metabolic switch to glycolysis has been suggested to support increased anabolic activities and facilitate T cell growth and proliferation, whether cellular metabolism controls T cell lineage choices remains poorly understood. Here we report that the glycolytic pathway is actively regulated during the differentiation of inflammatory TH17 and Foxp3-expressing regulatory T cells (Treg), and controls cell fate determination. TH17 but not Treg-inducing conditions resulted in strong upregulation of the glycolytic activity and induction of glycolytic enzymes. Blocking glycolysis inhibited TH17 development while promoting Treg cell generation. Moreover, the transcription factor hypoxia-inducible factor 1a (HIF1a) was selectively expressed in TH17 cells and its induction required signaling through mTOR, a central regulator of cellular metabolism. HIF1a-dependent transcriptional program was important for mediating glycolytic activity, thereby contributing to the lineage choices between TH17 and Treg cells. Lack of HIF1a resulted in diminished TH17 development but enhanced Treg differentiation, and protected mice from autoimmune CNS inflammation. Our studies demonstrate that HIF1a-dependent glycolytic pathway orchestrates a metabolic checkpoint for the differentiation of TH17 and Treg cells. Naïve CD4 T cells from wild-type and HIF1a-deficient mice (in triplicates each group) were differentiated under TH17 conditions for 2.5 days, and RNA was analyzed by microarrays.
Project description:Prolonged cellular hypoxia leads to energetic failure and death. However, sublethal hypoxia can trigger an adaptive response called hypoxic preconditioning. While prolyl-hydroxylase (PHD) enzymes and hypoxia inducible factors (HIFs) have been identified as key elements of oxygen sensing machinery, the mechanisms by which hypoxic preconditioning protects against insults remain unclear. Here, we perform serum metabolomic profiling to assess alterations induced by hypoxic preconditioning. We discover that hypoxic preconditioning increases serum kynurenine levels and enhance kynurenine biotransformation leading to preservation of NAD+ in the post-ischemic kidney. Furthermore, we show that Indoleamine 2,3-dioxygenase 1 (Ido1) deficiency abolishes the systemic increase of kynurenine and the subsequent renoprotection generated by hypoxic preconditioning. Importantly, exogenous administration of kynurenine restores the hypoxic preconditioning in the context of Ido1 deficiency. Collectively, our findings demonstrate a critical role of Ido1/kynurenine axis in mediating hypoxic preconditioning