Project description:The role of the transcription factor EB (TFEB) in the control of cellular functions, including in vascular bed, is mostly thought to be the regulation of lysosomal biogenesis and autophagic flux. While this is its best-known function, we report here the ability of TFEB to orchestrate a non-canonical program involved in the control of cell-cycle and VEGFR2 pathway in the developing vasculature. In endothelial cells, TFEB deletion halts proliferation by inhibiting the CDK4/Rb pathway, which regulates the cell cycle G1-S transition. In an attempt to overcome this limit, cells compensate by increasing the amount of VEGFR2 on the plasma membrane through a microRNA-mediated mechanism and the control of its membrane trafficking. TFEB transactivates the miR-15a/16-1 cluster, which limits the stability of the VEGFR2 transcript, and negatively modulates the expression of MYO1C, which regulates VEGFR2 delivery to the cell surface. In TFEB knocked-down cells, the reduced and increased amount respectively of miR-15a/16-1 and MYO1C result in the overexpression on plasmamembrane of VEGFR2, which however shows low signaling strength. Using endothelial loss-of-function Tfeb mouse mutants, we present evidence of defects in fetal and newborn mouse vasculature caused by the reduced endothelial proliferation and by the anomalous function of VEGFR2 pathway. Thus, this study revealed a new and unreported function of TFEB that expands its role beyond the regulation of autophagic pathway in the vascular system.
Project description:The role of the transcription factor EB (TFEB) in the control of cellular functions, including in vascular bed, is mostly thought to be the regulation of lysosomal biogenesis and autophagic flux. While this is its best-known function, we report here the ability of TFEB to orchestrate a non-canonical program involved in the control of cell-cycle and VEGFR2 pathway in the developing vasculature. In endothelial cells, TFEB deletion halts proliferation by inhibiting the CDK4/Rb pathway, which regulates the cell cycle G1-S transition. In an attempt to overcome this limit, cells compensate by increasing the amount of VEGFR2 on the plasma membrane through a microRNA-mediated mechanism and the control of its membrane trafficking. TFEB transactivates the miR-15a/16-1 cluster, which limits the stability of the VEGFR2 transcript, and negatively modulates the expression of MYO1C, which regulates VEGFR2 delivery to the cell surface. In TFEB knocked-down cells, the reduced and increased amount respectively of miR-15a/16-1 and MYO1C result in the overexpression on plasmamembrane of VEGFR2, which however shows low signaling strength. Using endothelial loss-of-function Tfeb mouse mutants, we present evidence of defects in fetal and newborn mouse vasculature caused by the reduced endothelial proliferation and by the anomalous function of VEGFR2 pathway. Thus, this study revealed a new and unreported function of TFEB that expands its role beyond the regulation of autophagic pathway in the vascular system.
Project description:The role of the transcription factor EB (TFEB) in the control of cellular functions, including in vascular bed, is mostly thought to be the regulation of lysosomal biogenesis and autophagic flux. While this is its best-known function, we report here the ability of TFEB to orchestrate a non-canonical program involved in the control of cell-cycle and VEGFR2 pathway in the developing vasculature. In endothelial cells, TFEB deletion halts proliferation by inhibiting the CDK4/Rb pathway, which regulates the cell cycle G1-S transition. In an attempt to overcome this limit, cells compensate by increasing the amount of VEGFR2 on the plasma membrane through a microRNA-mediated mechanism and the control of its membrane trafficking. TFEB transactivates the miR-15a/16-1 cluster, which limits the stability of the VEGFR2 transcript, and negatively modulates the expression of MYO1C, which regulates VEGFR2 delivery to the cell surface. In TFEB knocked-down cells, the reduced and increased amount respectively of miR-15a/16-1 and MYO1C result in the overexpression on plasmamembrane of VEGFR2, which however shows low signaling strength. Using endothelial loss-of-function Tfeb mouse mutants, we present evidence of defects in fetal and newborn mouse vasculature caused by the reduced endothelial proliferation and by the anomalous function of VEGFR2 pathway. Thus, this study revealed a new and unreported function of TFEB that expands its role beyond the regulation of autophagic pathway in the vascular system.
Project description:Analysis of ex vivo isolated lymphatic endothelial cells from the dermis of patients to define type 2 diabetes-induced changes. Results preveal aberrant dermal lymphangiogenesis and provide insight into its role in the pathogenesis of persistent skin inflammation in type 2 diabetes. The ex vivo dLEC transcriptome reveals a dramatic influence of the T2D environment on multiple molecular and cellular processes, mirroring the phenotypic changes seen in T2D affected skin. The positively and negatively correlated dLEC transcripts directly cohere to prolonged inflammatory periods and reduced infectious resistance of patients´ skin. Further, lymphatic vessels might be involved in tissue remodeling processes during T2D induced skin alterations associated with impaired wound healing and altered dermal architecture. Hence, dermal lymphatic vessels might be directly associated with T2D disease promotion. Global gene expression profile of normal dermal lymphatic endothelial cells (ndLECs) compared to dermal lymphatic endothelial cells derived from type 2 diabetic patients (dLECs).Quadruplicate biological samples were analyzed from human lymphatic endothelial cells (4 x diabetic; 4 x non-diabetic). subsets: 1 disease state set (dLECs), 1 control set (ndLECs)