Project description:Lung transplantation remains the only viable therapy for patients with end-stage lung disease; however, full utilization of this treatment strategy is severely compromised by the lack of donor lung availability. For example, the vast majority of donor lungs available for transplantation are obtained from brain death (BD) individuals. Unfortunately, the autonomic storm which accompanies BD often results in neurogenic pulmonary edema (NPE), thereby either producing irreversible lung injury or leading to primary graft dysfunction following lung transplantation. We previously demonstrated that sphingosine 1-phosphate (S1P), a phospholipid angiogenic factor and major barrier-enhancing agent, as well as S1P analogues serve to reduce vascular permeability and ischemia/reperfusion (I/R) lung injury in rodents via ligation of the S1P1 receptor, S1PR1. As primary lung graft dysfunction is induced by lung vascular endothelial cell barrier dysfunction, we hypothesized that SEW-2871, a S1PR1 agonist, may attenuate NPE when administered to the donor shortly after BD. Significant lung injury was observed 4h after BD in a rat BD model with ~60% increases in BAL total protein, BAL cell counts, and lung tissue W/D weight ratios. In contrast, rats receiving SEW-2871 (0.1 mg/kg) 15 minutes after the induction of BD and assessed 4h later exhibited significant lung protection (~50% reduction, p=0.01) reflected by reduced BAL total protein, BAL cytokines concentrations, BAL albumin, BAL total cell count and lung tissue wet/dry (W/D) weights ratio. Microarray analysis at 4hrs revealed a global impact of both BD and SEW on lung gene expression with differential expression of a subclass of genes enriched in immune/inflammation response pathways across the 4 experimental groups. Overall, SEW served to attenuate the BD-mediated ie gene expression upregulation. Two potentially useful biomarkers, Tnf and Ccrl2, exhibited gene dysregulation by microarray analysis, which was validated by qPCR. We conclude that SEW-2871 significantly attenuates BD-induced lung injury and may serve as a potential candidate to improve human lung donor availability and transplantation outcomes. Animals were divided into four groups: sham, BD (A Fogarty catheter 4 Fr. was inserted and secured into the extradural space and inflated to induce BD), SEW (injection of SEW-2871), and BD/SEW. Three replicates each.
Project description:Pulmonary alveolar microlithiasis is an autosomal recessive lung disease caused by a deficiency in the pulmonary epithelial Npt2b sodium-phosphate co-transporter that results in accumulation of phosphate and formation of hydroxyapatite microliths in the alveolar space. The single cell transcriptomic analysis of a pulmonary alveolar microlithiasis lung explant showing a robust osteoclast gene signature in alveolar monocytes and the finding that calcium phosphate microliths contain a rich protein and lipid matrix that includes bone resorbing osteoclast enzymes and other proteins suggested a role for osteoclast-like cells in the host response to microliths. While investigating the mechanisms of microlith clearance, we found that Npt2b modulates pulmonary phosphate homeostasis through effects on alternative phosphate transporter activity and alveolar osteoprotegerin, and that microliths induce osteoclast formation and activation in a receptor activator of nuclear factor kappa B (NF-kB) ligand and dietary phosphate dependent manner. This work reveals that Npt2b and pulmonary osteoclast like cells play key roles in pulmonary homeostasis and suggest potential new therapeutic targets for the treatment of lung disease.
Project description:Lung transplantation remains the only viable therapy for patients with end-stage lung disease; however, full utilization of this treatment strategy is severely compromised by the lack of donor lung availability. For example, the vast majority of donor lungs available for transplantation are obtained from brain death (BD) individuals. Unfortunately, the autonomic storm which accompanies BD often results in neurogenic pulmonary edema (NPE), thereby either producing irreversible lung injury or leading to primary graft dysfunction following lung transplantation. We previously demonstrated that sphingosine 1-phosphate (S1P), a phospholipid angiogenic factor and major barrier-enhancing agent, as well as S1P analogues serve to reduce vascular permeability and ischemia/reperfusion (I/R) lung injury in rodents via ligation of the S1P1 receptor, S1PR1. As primary lung graft dysfunction is induced by lung vascular endothelial cell barrier dysfunction, we hypothesized that SEW-2871, a S1PR1 agonist, may attenuate NPE when administered to the donor shortly after BD. Significant lung injury was observed 4h after BD in a rat BD model with ~60% increases in BAL total protein, BAL cell counts, and lung tissue W/D weight ratios. In contrast, rats receiving SEW-2871 (0.1 mg/kg) 15 minutes after the induction of BD and assessed 4h later exhibited significant lung protection (~50% reduction, p=0.01) reflected by reduced BAL total protein, BAL cytokines concentrations, BAL albumin, BAL total cell count and lung tissue wet/dry (W/D) weights ratio. Microarray analysis at 4hrs revealed a global impact of both BD and SEW on lung gene expression with differential expression of a subclass of genes enriched in immune/inflammation response pathways across the 4 experimental groups. Overall, SEW served to attenuate the BD-mediated ie gene expression upregulation. Two potentially useful biomarkers, Tnf and Ccrl2, exhibited gene dysregulation by microarray analysis, which was validated by qPCR. We conclude that SEW-2871 significantly attenuates BD-induced lung injury and may serve as a potential candidate to improve human lung donor availability and transplantation outcomes.
Project description:RNA sequencing was used to evaluate genes regulated in C3H10T1/2 cells by the G protein-coupled receptor agonist sphingosine 1-phosphate.
Project description:Summary: Brain trauma is a major cause of morbidity and mortality, both in adult and pediatric populations. Much of the functional deficit derives from delayed cell death resulting from induction of neurotoxic factors that overwhelm endogenous neuroprotective responses. Hypothesis: Gene expression profiling across species and models may help identify candidate molecular pathways induced by brain injury, some of which may provide novel targets for therapeutic intervention. Specific Aim: To identify the potential molecular mechanisms underlying such delayed responses, we compared gene expression patterns using high-density oligonucleotide arrays at 4, 8, 24 and 72 hours after moderate levels of lateral fluid percussion-induced brain injury in rats and lateral controlled cortical impact injury in mice.
Project description:Hepatic injury is often accompanied by pulmonary inflammation and tissue damage, but the underneath mechanism is not fully elucidated. Here we identify hepatic miR-122 as a culprit of pulmonary inflammation induced by various liver injuries. Analyses of acute and chronic liver injury mouse models confirm that liver dysfunction can cause pulmonary inflammation and tissue damage. Injured livers release large amounts of miR-122 in a microvesicle-independent manner into the circulation compared to normal livers. Circulating miR-122 is then preferentially transported to mouse lungs and taken up by alveolar macrophages, in which it binds toll-like receptor 7 (TLR7) and activates inflammatory responses. Depleting plasma miR-122 largely abolishes liver injury-induced pulmonary inflammation and tissue damage. Furthermore, alveolar macrophage activation by miR-122 is blocked by mutating the TLR7-binding UG-rich sequence on miR-122 or knocking out macrophage TLR7. Our findings reveal a novel causative role of hepatic miR-122 in liver injury-induced pulmonary dysfunction.
Project description:PPARδ is emerging as a key metabolic regulator with pleiotropic actions on various tissues including fat, skeletal muscle and liver. The aim of our study was to assess the effect of either the well-validated PPARδ agonist GW501516, or a novel PPARδ agonist KD3010 in mouse models of liver fibrosis. KD3010, but not GW501516, treated mice had markedly less liver injury induced by carbon tetrachloride (CCl4) injections. Deposition of extracellular matrix proteins was lower in the KD3010 group as compared to the vehicle or GW501516 treated group. Interestingly, profibrogenic CTGF was significantly induced by GW501516, but not KD3010, following CCl4 treatment. The hepatoprotective and antifibrotic effect of KD3010 was confirmed in a model of cholestasis-induced liver injury and fibrosis using bile duct ligation for three weeks. Hepatocytes were identified as targets for PPARδ agonist, and primary hepatocytes treated with KD3010 showed decreased serum starvation or CCl4-induced cell death, while GW501516 treated hepatocytes were not protected. KD3010 treatment of hepatocytes decreased reactive oxygen species (ROS) production after CCl4 exposure. In conclusion, our data demonstrate that a novel PPARδ agonist has hepatoprotective and antifibrotic effects in animal models of liver fibrosis. Given the oral availability and the favorable pharmacologic profile of KD3010, ligand activation of PPARδ represents an attractive and promising target for patients with chronic liver diseases. Total RNA was extracted from primary mouse hepatocytes treated with DMSO or PPARd agonists (KD3010, GW1516)
Project description:Background: Previous study showed that stroke may be a potential first sign of neoplasia. But the relationship between them remains unclear. Besides, ischemic stroke is a complex brain disease, which involves cell death or complex immune regulation. Thus, it is necessary to reveal the association of tumor immune microenvironment and cell death with ischemic stroke. Methods: Here, a photothrombosis-induced ischemic injury models of brain and skull was established. We compared and analyzed the pattern of gene expression profile between brain and skull after ischemic injury by transcriptome analysis. Further, we investigated the enrichment of relevant differential genes in cancer pathways and cell death pathways, and analyzed changes in the immune microenvironment after ischemic injury. Moreover, the pan-cancer genomic and prognosis analysis of ischemic injury related gene set were performed. Results: The results showed that the gene expression patterns were different in temporal and spatial locations after ischemic injury. We found that the effect on the transcriptome of the brain after skull ischemic injury was particularly large, but it could be recovered in a short period, while the effect on the skull after brain ischemic injury was long-lasting. The expression of genes related to ischemic injury is also associated with cell death and cancer hallmark pathways. In addition, changes in the abundance of immune cells indicate that brain ischemic injury may disrupt its immune microenvironment for a longer time, while skull can better balance the stability of immune microenvironment. Moreover, the brain ischemic injury-related gene sets are highly correlated with a variety of tumors, especially GBM, KIRC, LGG and UVM after stroke have a greater risk of death. Conclusion: This study gives us a new understanding of the role of the skull in brain ischemic injury, and reveals the association of tumor immune microenvironment and cell death with ischemic stroke.