Telomeric repeat binding factor 2 (TRF2), which plays a central role in telomere capping, is frequently increased in human tumors. We reveal here that TRF2 is expressed in the vasculature of most human cancer types, where it colocalizes with the Wilms' tumor suppressor WT1. We further show that TRF2 is a transcriptional target of WT1 and is required for proliferation, migration, and tube formation of endothelial cells. These angiogenic effects of TRF2 are uncoupled from its function in telomere capping. Instead, TRF2 binds and transactivates the promoter of the angiogenic tyrosine kinase platelet-derived growth factor receptor β (PDGFRβ). These findings reveal an unexpected role of TRF2 in neoangiogenesis and delineate a distinct function of TRF2 as a transcriptional regulator.
Cellular senescence affects many physiological and pathological processes and is characterized by durable cell cycle arrest, an inflammatory secretory phenotype and metabolic reprogramming. Here, by using dynamic transcriptome and metabolome profiling in human fibroblasts with different subtypes of senescence, we show that a homoeostatic switch that results in glycerol-3-phosphate (G3P) and phosphoethanolamine (pEtN) accumulation links lipid metabolism to the senescence gene expression programme. Mechanistically, p53-dependent glycerol kinase activation and post-translational inactivation of phosphate cytidylyltransferase 2, ethanolamine regulate this metabolic switch, which promotes triglyceride accumulation in lipid droplets and induces the senescence gene expression programme. Conversely, G3P phosphatase and ethanolamine-phosphate phospho-lyase-based scavenging of G3P and pEtN acts in a senomorphic way by reducing G3P and pEtN accumulation. Collectively, our study ties G3P and pEtN accumulation to controlling lipid droplet biogenesis and phospholipid flux in senescent cells, providing a potential therapeutic avenue for targeting senescence and related pathophysiology.
Health and resilience of the coral holobiont depend on diverse bacterial communities often dominated by key marine symbionts of theEndozoicomonadaceaefamily. The factors controlling their distribution and their functional diversity remain, however, poorly known. Here, we study the ecology ofEndozoicomonadaceaeat an ocean basin-scale by sampling specimens from three coral genera (Pocillopora,Porites,Millepora) on 99 reefs from 32 islands across the Pacific Ocean. The analysis of 2447 metabarcoding and 270 metagenomic samples reveals that each coral genus harbored a distinct new species ofEndozoicomonadaceae. These species are composed of nine lineages that have distinct biogeographic patterns. The most common one, found inPocillopora, appears to be a globally distributed symbiont with distinct metabolic capabilities, including the synthesis of amino acids and vitamins not produced by the host. The other lineages are structured partly by the host genetic lineage inPocilloporaand mainly by the geographic location inPorites.Milleporais more rarely associated toEndozoicomonadaceae. Our results show that different coral genera exhibit distinct strategies of host-Endozoicomonadaceaeassociations that are defined at the bacteria lineage level.