Project description:Acute Lung Injury (ALI) causes the highly lethal Acute Respiratory Distress Syndrome (ARDS) in children and adults, for which therapy is lacking. Children with Pediatric ARDS (PARDS) have a mortality rate that is about half of adults with ARDS. Improved ALI measures can be reproduced in rodent models with juvenile animals, suggesting that physiologic differences may underlie these different outcomes. Here, we show that pneumonia-induced ALI caused inflammatory signaling in the endothelium of adult mice which depended on Yes-associated protein (YAP). This signaling was not present in 21-day-old weanling mice. Transcriptomic analysis of lung endothelial responses revealed nuclear factor kappa-B (NF-kB) as significantly increased with ALI in adult versus weanling mice. Blockade of YAP signaling protected against ALI and NF-kB nuclear translocation in adult mice. Our results demonstrate an important signaling cascade in the lung endothelium of adult mice that is not present in weanlings. We suggest other pathways may also exhibit age-dependent inflammatory signaling, which would have important implications for therapeutics in the adult and pediatric age groups.
Project description:Maturation of lung cell types occurs during late gestation to ensure lung function and optimal gas exchange at birth. The pulmonary lymphatic endothelium is an understudied cell type and is essential for immune regulation and interstitial fluid removal. Here we provide the first characterization of the pulmonary lymphatic endothelium during late gestation prior to birth. We used microarrays to detail the global transcriptional programme underlying maturation of pulmonary lymphatic endothelium and identified 1,281 genes with significant changes in gene expression over time. Gene expression was validated by qPCR and in situ hybridization, which indicated a potential role for IFN-I signaling in pulmonary lymphatic endothelial cell (PLEC) maturation prior to birth.
Project description:We investigate the MED1/KLF4 co-regulation of the BMP/TGF-beta axes in endothelium by studying the epigenetic regulation of BMP receptor type II (BMPR2), ETS-related gene (ERG), and TGF-beta receptor 2 (TGFBR2) and their involvement in the PH. High throughput screening involving data from RNA-seq, MED1 ChIP-seq, H3K27ac ChIP-seq, KLF4 ATAC-seq, and high-throughput chromosome conformation capture (HiC) together with in silico computations were used to explore the epigenetic and transcriptional regulation of BMPR2, ERG, and TGFBR2 by MED1 and KLF4. In vitro experiments with cultured pulmonary arterial endothelial cells (PAECs) and bulk assays were used to validate results from these in silico analyses. Lung tissue from patients with idiopathic pulmonary arterial hypertension (IPAH), animals with experimental PH, and mice with endothelial ablation of MED1 (EC-MED1-/-) were used to study the PH-protective effect of MED1. Levels of MED1 were decreased in lung tissue or PAECs from IPAH patients and rodent PH models. Mechanistically, MED1 acted synergistically with KLF4 to transactivate BMPR2, ERG, and TGFBR2 via chromatin remodeling and enhancer-promoter interactions. EC-MED1-/- mice showed PH susceptibility. In contrast, MED1 overexpression mitigated the PH phenotype in rodents. A homeostatic regulation of BMPR2, ERG, and TGFBR2 in ECs by MED1 synergistic with KLF4 is essential for the normal function of the pulmonary endothelium. Dysregulation of MED1 and the resulting impairment of the BMP/TGF- signaling is implicated in the disease progression of PAH in humans and PH in rodent models.
Project description:SARS-CoV-2 seriously injures human alveoli and causes severe respiratory illness. Histopathologic evidences suggested alveolar-capillary barrier integrity is compromised in COVID-19 deaths, however, little is known about how it is disrupted. In this study, we investigated the effects of SARS-CoV-2 infection on alveolar epithelium and pulmonary microvascular endothelium, and tried to elucidate the cross-talk between them during viral infection. Under monoculture system, SARS-CoV-2 infection caused massive virus replication and dramatic organelles re-modeling in alveolar epithelial cells. While, as for pulmonary microvascular endothelial cells, direct viral exposure had little effect on them, but treatment with culture supernatant from infected epithelial cells significantly damaged them, which suggested SARS-CoV-2 affected endothelium indirectly, possibly by substances released from infected alveolar epithelium. Then, we tested SARS-CoV-2 infection in an alveolar epithelium/endothelium co-culture system, and found viral infection caused global proteomic modulations and ultrastructural changes in both cell types. Especially for alveolar epithelial cells, viral infection elicited significant protein changes and structural reorganizations across many sub-cellular compartments. Among the affected organelles, mitochondrion seems to be a primary target organelle. In addition, based on proteomic analysis and EM clues, we tested several autophagy inhibitors, and discovered one of them, Daurisoline, could inhibit virus replication effectively in cells. Collectively, our study revealed the distinctive responses of alveolar epithelium and microvascular endothelium to SARS-CoV-2 infection, which will expand our understanding of COVID-19 and helpful for targeted drug development.
Project description:SARS-CoV-2 seriously injures human alveoli and causes severe respiratory illness. Histopathologic evidences suggested alveolar-capillary barrier integrity is compromised in COVID-19 deaths, however, little is known about how it is disrupted. In this study, we investigated the effects of SARS-CoV-2 infection on alveolar epithelium and pulmonary microvascular endothelium, and tried to elucidate the cross-talk between them during viral infection. Under monoculture system, SARS-CoV-2 infection caused massive virus replication and dramatic organelles re-modeling in alveolar epithelial cells. While, as for pulmonary microvascular endothelial cells, direct viral exposure had little effect on them, but treatment with culture supernatant from infected epithelial cellls significantly damaged them, which suggested SARS-CoV-2 affected endothelium indirectly, possibly by substances released from infected alveolar epithelium. Then, we tested SARS-CoV-2 infection in an alveolar epithelium/endothelium co-culture system, and found viral infection caused global proteomic modulations and ultrastructual changes in both cell types. Especially for alveolar epithelial cells, viral infection elicited significant protein changes and structural reorganizations across many sub-cellular compartments. Among the affected organelles, mitochondrion seems to be a primary target organelle. In addition, based on proteomic analysis and EM clues, we tested several autophagy inhibitors, and discovered one of them, Daurisoline, could inhibit virus replication effectively in cells. Collectively, our study revealed the distinctive responses of alveolar epithelium and microvascular endothelium to SARS-CoV-2 infection, which will expand our understanding of COVID-19 and helpful for targeted drug development.
Project description:This experiment was carried out to see if there were any miRNA expression differences in pulmonary endothelial cells between patients with and without COPD. COPD is an inflammatory condition and although much work has previously been performed to investigate the inflammatory cells in COPD there has not been as much research looking at the endothelium through which inflammatory cells must pass through to reach the lung tissue. In this experiment pulmonary endothelial cells were extracted from whole lung tissue removed at the time of cardiothoracic surgery. This was performed for patients with and without COPD. RNA was extracted using the Qiagen microRNeasy kits prior to transferring to the University of Birmingham Biosciences department who performed RNA labelling and ran the microarrays. Once the microarrays were performed quality was checked using ArrayQualityMetrics and the COPD group was compared to the non-COPD group using SAM. The experiment was then repeated using another patient group. MiRNAs of interest were validated with qPCR initially before moving on to functional work.
Project description:This experiment was carried out to see if there were any miRNA expression differences in pulmonary endothelial cells between patients with and without COPD. COPD is an inflammatory condition and although much work has previously been performed to investigate the inflammatory cells in COPD there has not been as much research looking at the endothelium through which inflammatory cells must pass through to reach the lung tissue. In this experiment pulmonary endothelial cells were extracted from whole lung tissue removed at the time of cardiothoracic surgery. This was performed for patients with and without COPD. RNA was extracted using the Qiagen microRNeasy kits prior to transferring to the University of Birmingham Biosciences department who performed RNA labelling and ran the microarrays. Once the microarrays were performed quality was checked using ArrayQualityMetrics and the COPD group was compared to the non-COPD group using SAM. The experiment was then repeated using another patient group. MiRNAs of interest were validated with qPCR initially before moving on to functional work.