Project description:The PHD/HIF pathway has been implicated in a wide range of immune and inflammatory processes, including in the oxygen‐deprived tumor microenvironment. To examine the effect of HIF stabilization in anti‐tumor immunity, we deleted Phd2 selectively in T lymphocytes using the cre/lox system. We show that the deletion of PHD2 in lymphocytes resulted in enhanced regression of EG7‐OVA tumors, in a HIF‐1adependent manner. The enhanced control of neoplastic growth correlated with increased poly‐functionality of CD8+ tumor‐infiltrating lymphocytes, i.e. enhanced expression of IFN‐g, TNF‐a and granzyme B. Phenotypic and transcriptomic analyses point to a key role of glycolysis in sustaining CTL activity in the tumor bed and identifies the PHD2/HIF‐1 pathway as potential target for intervention.
Project description:To identify novel regulator of EGLN1/PHD2, we performed label-free quantitative interactome analysis. Stable Hela cell lines expressing Flag-tagged PHD2 and control vector were generated. Immunoprecipitation and mass spectrometry analysis were performed to identify novel interactors of PHD2 followed by validation and functional analysis.
Project description:In our study, we utilized cutting-edge CrisPR-Cas9 technology to evaluate the effects of deleting prolyl hydroxylase domain-containing enzymes (PHD) 2 and 3, which stabilizes HIF-1 signaling, in CD8 T cells that have already undergone differentiation and activation, mirroring the conditions encountered in clinical settings. Our study revealed a significant boost in T-cell activation and effector functions after PHD2/3 deletion, and conclusively established its dependence on HIF-1. This improvement in CD8 T cell performance translated into a remarkable enhancement in the response to adoptive T cell therapy, across various tumor models, even including those reported to be extremely resistant to immunotherapeutic interventions. Furthermore, our data provide compelling evidence that the increased effector functions observed in PHD-deficient (KO) CD8 T cells are intricately linked to an increased glycolytic flux. These findings hold significant promise for advancing CD8 T -cell based therapies and overcoming the immune suppression barriers within challenging tumor microenvironments.
Project description:To study the cell composition and gene expression profile in the mesendoderm differentiation of WT and PHD2 knockout, we performed scRNA-seq on the cells collected from the differentiation of WT and PHD2 knockout AB2.2 mESCs at differentiation day 4. PHD2 knockoutout mESCs were constructed by CRISPR/Cas9. The differentiation was performed using a non-lineage tendency differentiation protocol.
Project description:Prolyl hydroxylase domain protein 2 (PHD2) is one of the intracellular oxygen sensors that mediates proteasomal degradation of hypoxia-inducible factor (HIF)-α via hydroxylation under normoxia. Because of its canonical function in the hypoxia signaling pathway, PHD2 is generally regarded as a tumor suppressor. However, the effects of PHD2 in tumorigenesis are not entirely dependent on HIF-α. Based on the data obtained from The Cancer Genome Atlas (TCGA) database, we found that the expression of PHD2 is upregulated in non-small cell lung cancer (NSCLC), which accounts for approximately 80-85% of lung cancers, suggesting that PHD2 may play an important role in NSCLC. However, the function of PHD2 in NSCLC remains largely unknown. In this study, we established PHD2-deficient H1299 cells to investigate the function of PHD2 in NSCLC, and found that PHD2 suppressed cell proliferation and metabolism, but induced ROS levels in human NSCLC cells. Further results indicated that the function of PHD2 in NSCLC is dependent on its enzymatic activity and partially independent of HIF. Moreover, we performed RNA-seq and transcriptomics analysis to explore the underlying mechanisms, and identified some potential targets and pathways regulated by PHD2, apart from the canonical HIF-mediated hypoxia signaling pathway. These results provide some clues to uncover novel roles of PHD2 in lung cancer progression.
Project description:Ischemic heart disease is the leading cause of heart failure. Both clinical trials and experimental animal studies demonstrate that chronic hypoxia can induce contractile dysfunction even before substantial ventricular damage, implicating a direct role of oxygen in the regulation of cardiac contractile function. Prolyl hydroxylase domain (PHD) proteins are well recognized as oxygen sensors and mediate a wide variety of cellular events by hydroxylating a growing list of protein substrates. Both PHD2 and 3 are highly expressed in the heart, yet their functional roles in modulating contractile function remain incompletely understood. Here, we report that combined deletion of PHD2 and 3 dramatically decreases the expression of phospholamban (PLN), results in sustained activation of CaMKII and sensitizes mice to myocardial injury induced by chronic β-adrenergic stress. We provide evidence that thyroid hormone receptor-α (TR-α), a transcriptional regulator of PLN, interacts with PHD2 and 3 and is hydroxylated at two proline residues. Inhibition of PHDs increases the interaction between TR-α and nuclear receptor co-repressor 2 (NCOR2) and suppresses PLN transcription. These observations provide new mechanistic insights into how oxygen directly modulates cardiac contractility, providing the possibility that cardiac function can be modulated therapeutically by tuning PHD enzymatic activity. Two-condition experiment comparing gene expression in hearts isolated from PHD2/3f/f; Cre-/- and PHD2/3f/f; Cre+/- mice. Three biological replicates (mouse hearts) per condition.
Project description:The mRNA abundance in the wild-type or Phd2 knockout carotid body and adrenal medulla of mice was analysed by RNA-Seq. For this purpose, mice with tyrosine hydroxylase-restricted inactivation of Phd2 were generated. For the preparation of a single RNA-Seq library, RNA from 10 carotid bodies or adrenal medullas from 5 mice was pooled.