Browsing by Subject "Dioxygenases"

Now showing 1 - 3 of 3
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    Il-1r1 drives leukemogenesis induced by Tet2 loss
    (Springer Nature, 2022-10) Burns, Sarah S.; Kumar, Ramesh; Pasupuleti, Santhosh Kumar; So, Kaman; Zhang, Chi; Kapur, Reuben; Pediatrics, School of Medicine
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    Physioxia-induced downregulation of Tet2 in hematopoietic stem cells contributes to enhanced self-renewal
    (American Society of Hematology, 2022) Aljoufi, Arafat; Zhang, Chi; Ropa, James; Chang, Wennan; Palam, Lakshmi Reddy; Cooper, Scott; Ramdas, Baskar; Capitano, Maegan L.; Broxmeyer, Hal E.; Kapur, Reuben; Microbiology and Immunology, School of Medicine
    Hematopoietic stem cells (HSCs) manifest impaired recovery and self-renewal with a concomitant increase in differentiation when exposed to ambient air as opposed to physioxia. Mechanism(s) behind this distinction are poorly understood but have the potential to improve stem cell transplantation. Single-cell RNA sequencing of HSCs in physioxia revealed upregulation of HSC self-renewal genes and downregulation of genes involved in inflammatory pathways and HSC differentiation. HSCs under physioxia also exhibited downregulation of the epigenetic modifier Tet2. Tet2 is α-ketoglutarate, iron- and oxygen-dependent dioxygenase that converts 5-methylcytosine to 5-hydroxymethylcytosine, thereby promoting active transcription. We evaluated whether loss of Tet2 affects the number and function of HSCs and hematopoietic progenitor cells (HPCs) under physioxia and ambient air. In contrast to wild-type HSCs (WT HSCs), a complete nonresponsiveness of Tet2-/- HSCs and HPCs to changes in oxygen tension was observed. Unlike WT HSCs, Tet2-/- HSCs and HPCs exhibited similar numbers and function in either physioxia or ambient air. The lack of response to changes in oxygen tension in Tet2-/- HSCs was associated with similar changes in self-renewal and quiescence genes among WT HSC-physioxia, Tet2-/- HSC-physioxia and Tet2-/- HSC-air. We define a novel molecular program involving Tet2 in regulating HSCs under physioxia.
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    Vasculogenic skin reprogramming requires TET-mediated gene demethylation in fibroblasts for rescuing impaired perfusion in diabetes
    (Springer Nature, 2024-11-27) Mohanty, Sujit K.; Singh, Kanhaiya; Kumar, Manishekhar; Verma, Sumit S.; Srivastava, Rajneesh; Gnyawali, Surya C.; Palakurti, Ravichand; Sahi, Ajay K.; El Masry, Mohamed S.; Banerjee, Pradipta; Kacar, Sedat; Rustagi, Yashika; Verma, Priyanka; Ghatak, Subhadip; Hernandez, Edward; Rubin, J. Peter; Khanna, Savita; Roy, Sashwati; Yoder, Mervin C.; Sen, Chandan K.; Surgery, School of Medicine
    Tissue nanotransfection (TNT) topically delivers Etv2, Foxc2, and Fli1 (EFF) plasmids increasing vasculogenic fibroblasts (VF) and promoting vascularization in ischemic murine skin. Human dermal fibroblasts respond to EFF nanoelectroporation with elevated expression of endothelial genes in vitro, which is linked to increased ten-eleven translocase 1/2/3 (TET) expression. Single cell RNA sequencing dependent validation of VF induction reveals a TET-dependent transcript signature. TNTEFF also induces TET expression in vivo, and fibroblast-specific EFF overexpression leads to VF-transition, with TET-activation correlating with higher 5-hydroxymethylcytosine (5-hmC) levels in VF. VF emergence requires TET-dependent demethylation of endothelial genes in vivo, enhancing VF abundance and restoring perfusion in diabetic ischemic limbs. TNTEFF improves perfusion and wound closure in diabetic mice, while increasing VF in cultured human skin explants. Suppressed in diabetes, TET1/2/3 play a critical role in TNT-mediated VF formation which supports de novo blood vessel development to rescue diabetic ischemic tissue.