Project description:Following acute injury, the capillary vascular bed in the lung must be repaired to reestablish gas exchange between pulmonary endothelial cells (ECs) lining these vessels and the alveolar epithelium. However, the factors that control EC stress response and drive regeneration of pulmonary capillaries remain incompletely understood. Viral infections such as influenza and COVID-19 may indirectly damage lung vasculature through loss of epithelial gas exchange partners or through signaling from infiltrating immune cells. To prevent excessive tissue damage and to renew the endothelium, ECs must both withstand cellular stress and proliferate after injury. Here, we show that the transcription factor and immediate early gene Atf3 is essential for both responses in the mouse lung after influenza infection. Atf3 expression defines a subpopulation of capillary ECs enriched in genes involved in cellular response to stress, angiogenesis, and vascular development. Endothelial loss of ATF3 results in defective alveolar regeneration: in the absence of ATF3, ECs exhibit increased apoptosis and decreased proliferation, resulting in an emphysema-like phenotype with enlarged alveolar airspaces lined with regions of lost vasculature. These data implicate ATF3 as an essential component of the vascular response to acute lung injury that is required for successful lung regeneration.
Project description:Acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), cause severe endothelial dysfunction in the lung and vascular endothelial growth factor (VEGF) is elevated in ARDS. We have found that the levels of a VEGF-regulated microRNA, microRNA-1 (miR-1) is reduced in the lung endothelium after acute injury. Pulmonary endothelial cell (EC)-specific overexpression of miR-1 protects the lung against cell death and barrier dysfunction in both murine and human models and increases the survival of mice after pneumonia-induced ALI. MiR-1 has an intrinsic protective effect in pulmonary and other types of ECs; it inhibits apoptosis and necroptosis pathways and decreases capillary leak by protecting adherens and tight junctions. Comparative gene expression analysis and RISC recruitment assays identified miR-1 targets in the context of injury, including phosphodiesterase 5A (PDE5A), angiopoetin-2 (ANGPT2), connector enhancer of kinase suppressor of ras 3 (CNKSR3) and TNF alpha induced protein 2 (TNFAIP2). We validated miR-1-mediated regulation of ANGPT2 in both mouse and human ECs and found that in a 119-patient pneumonia cohort, miR-1 correlated inversely with ANGPT2. These findings illustrate the novel role of miR-1 as a cytoprotective orchestrator of endothelial response to acute injury with prognostic and therapeutic potential.
Project description:Acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), cause severe endothelial dysfunction in the lung and vascular endothelial growth factor (VEGF) is elevated in ARDS. We have found that the levels of a VEGF-regulated microRNA, microRNA-1 (miR-1) is reduced in the lung endothelium after acute injury. Pulmonary endothelial cell (EC)-specific overexpression of miR-1 protects the lung against cell death and barrier dysfunction in both murine and human models and increases the survival of mice after pneumonia-induced ALI. MiR-1 has an intrinsic protective effect in pulmonary and other types of ECs; it inhibits apoptosis and necroptosis pathways and decreases capillary leak by protecting adherens and tight junctions. Comparative gene expression analysis and RISC recruitment assays identified miR-1 targets in the context of injury, including phosphodiesterase 5A (PDE5A), angiopoetin-2 (ANGPT2), connector enhancer of kinase suppressor of ras 3 (CNKSR3) and TNF alpha induced protein 2 (TNFAIP2). We validated miR-1-mediated regulation of ANGPT2 in both mouse and human ECs and found that in a 119-patient pneumonia cohort, miR-1 correlated inversely with ANGPT2. These findings illustrate the novel role of miR-1 as a cytoprotective orchestrator of endothelial response to acute injury with prognostic and therapeutic potential.
Project description:Exercise is a powerful driver of physiological angiogenesis during adulthood, but the mechanisms of exercise-induced vascular expansion are poorly understood. We explored endothelial heterogeneity in skeletal muscle and identified two capillary muscle endothelial cells (mEC) populations which are characterized by differential expression of ATF3/4. Spatial mapping showed that ATF3/4 + mECs are enriched in red oxidative muscle areas while ATF3/4 low ECs lie adjacent to white glycolytic fibers. In vitro and in vivo experiments revealed that red ATF3/4 + mECs are more angiogenic when compared to white ATF3/4 low mECs. Mechanistically, ATF3/4 in mECs control genes involved in amino acid uptake and metabolism and metabolically prime red (ATF3/4 + ) mECs for angiogenesis. As a consequence, supplementation of non-essential amino acids and overexpression of ATF4 increased proliferation of white mECs. Finally, deleting Atf4 in ECs impaired exercise-induced angiogenesis. Our findings illustrate that spatial metabolic angiodiversity determines the angiogenic potential of muscle ECs.
Project description:Cardiac resident MerTK+ macrophages exert multiple protective roles post-ischemic injury, however, the mechanisms regulating their fate are not fully understood. Here we show that GAS6-inducible transcription factor ATF3 prevents apoptosis of MerTK+ macrophages after ischemia-reperfusion (IR) injury, by repressing the transcription of multiple genes involved in type I interferon expression (Ifih1 and Infb1) and apoptosis (Apaf1). Mice lacking ATF3 in cardiac macrophages or myeloid cells showed excessive loss of MerTK+ cardiac macrophages, poor angiogenesis, and worse heart dysfunction post-IR, which were rescued by the transfer of MerTK+ cardiac macrophages. GAS6 administration improved cardiac repair in an ATF3-dependent manner. Finally, we showed a negative association of GAS6 and ATF3 expression with the risk of major adverse cardiac events in patients with ischemic heart disease. These results indicate that the GAS6-ATF3 axis has a protective role against IR injury by regulating MerTK+ cardiac macrophage survival/proliferation.
Project description:Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a common life-threatening critical syndrome with no effective pharmacotherapy. Extracellular vesicles (EVs) are considered as a new way of long-distance communication between cells. Our previous research using an ex vivo perfused human ALI model suggested that endothelial cell-derived EVs (EC-EVs) mediate the development of ALI/ARDS. However, how EC-EVs aggravate lung injury remains largely unknown. Here we demonstrated that EC-EVs released under inflammatory stimulation are preferentially taken up by monocytes and reprogram the differentiation of monocytes towards M1 type macrophage. These findings demonstrate a previously unidentified mechanism by which distant infections could lead to ALI/ARDS, providing novel targets and strategies for the prevention and treatment of sepsis-related ALI/ARDS.
Project description:In order to characterize genomic response and identify molecular marker for acute neural injury, we performed RNA-sequencing 4 hours after spinal cord injury. We found a group of genes with significant differential expression (DEG) after Benjamini-Hochberg FDR multiple corrections. These DEGs mainly include early response genes, neuroinflammation, and cell injury and death. Notely, activating transcription factor 3 (ATF3) is one of the most significantly upregulated genes by 9.9 folds and is a well-recognized molecular marker for DRG sensory neuron injury in peripheral nerve injury model.
Project description:We utilized high-throughput single-cell transcriptomics to identify endothelial subpopulations and track their responses to inflammatory injury.
Project description:The goal of this observational study is to compare anesthetic modalities (intravenous propofol anesthesia with sevoflurane gas anesthesia) in patients who underwent colorectal cancer resection surgery regarding the outcome of acute kidney injury.
The main questions it aims to answer are:
* is there a difference in acute kidney injury incidence in the two anesthetic modalities?
* is there a difference in plasma creatinine between the two anesthetic modalities?
* are there any patient characteristics or intraoperative factors that effect the incidence of acute kidney injury in either anesthetic modality?
The study will analyze data from the CAN clinical trial database. (Cancer and Anesthesia: Survival After Radical Surgery - a Comparison Between Propofol or Sevoflurane Anesthesia, NCT01975064)