| Autor: |
Favara DM; Balliol College, University of Oxford, Oxford OX1 3BJ, UK.; Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK., Zois CE; Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK., Haider S; Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK.; Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London SW7 3RP, UK., Pires E; Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK., Sheldon H; Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK., McCullagh J; Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK., Banham AH; Nuffield Division of Clinical Laboratory Science, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK., Harris AL; Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK. |
| Abstrakt: |
Adhesion G Protein-Coupled Receptor L4 (ADGRL4/ELTD1) is an endothelial cell adhesion G protein-coupled receptor (aGPCR) which regulates physiological and tumour angiogenesis, providing an attractive target for anti-cancer therapeutics. To date, ADGRL4/ELTD1's full role and mechanism of function within endothelial biology remains unknown, as do its ligand(s). In this study, ADGRL4/ELTD1 silencing, using two independent small interfering RNAs (siRNAs), was performed in human umbilical vein endothelial cells (HUVECS) followed by transcriptional profiling, target gene validation, and metabolomics using liquid chromatography-mass spectrometry in order to better characterise ADGRL4/ELTD1's role in endothelial cell biology. We show that ADGRL4/ELTD1 silencing induced expression of the cytoplasmic metabolic regulator ATP Citrate Lyase (ACLY) and the mitochondria-to-cytoplasm citrate transporter Solute Carrier Family 25 Member 1 (SLC25A1) but had no apparent effect on pathways downstream of ACLY (fatty acid and cholesterol synthesis or acetylation). Silencing induced KIT expression and affected the Notch signalling pathway, upregulating Delta Like Canonical Notch Ligand 4 (DLL4) and suppressing Jagged Canonical Notch Ligand 1 ( JAG1 ) and Hes Family BHLH Transcription Factor 2 ( HES2 ). The effect of ADGRL4/ELTD1 silencing on the cellular metabolic profile was modest but several metabolites were significantly affected. Cis-aconitic acid, uridine diphosphate (UDP)-glucoronate, fructose 2,6-diphosphate, uridine 5-diphosphate, and aspartic acid were all elevated as a result of silencing and phosphocreatine, N-acetylglutamic acid, taurine, deoxyadenosine triphosphate, and cytidine monophosphate were depleted. Metabolic pathway analysis implicated ADGRL4/ELTD1 in pyrimidine, amino acid, and sugar metabolism. In summary, this study shows that ADGRL4/ELTD1 impacts core components of endothelial metabolism and regulates genes involved in endothelial differentiation/homeostasis and Notch signalling. |
