Project description:Mechanical ventilation is a life-saving intervention in critically ill patients with respiratory failure due to acute respiratory distress syndrome (ARDS). Paradoxically, mechanical ventilation also creates excessive mechanical stress that directly augments lung injury, a syndrome known as ventilator-induced lung injury (VILI). The pathobiology of VILI and ARDS shares many inflammatory features including increases in lung vascular permeability due to loss of endothelial cell barrier integrity resulting in alveolar flooding. While there have been advances in the understanding of certain elements of VILI and ARDS pathobiology, such as defining the importance of lung inflammatory leukocyte infiltration and highly induced cytokine expression, a deep understanding of the initiating and regulatory pathways involved in these inflammatory responses remains poorly understood. Prevailing evidence indicates that loss of endothelial barrier function plays a primary role in the development of VILI and ARDS. Thus this review will focus on the latest knowledge related to 1) the key role of the endothelium in the pathogenesis of VILI; 2) the transcription factors that relay the effects of excessive mechanical stress in the endothelium; 3) the mechanical stress-induced posttranslational modifications that influence key signaling pathways involved in VILI responses in the endothelium; 4) the genetic and epigenetic regulation of key target genes in the endothelium that are involved in VILI responses; and 5) the need for novel therapeutic strategies for VILI that can preserve endothelial barrier function.
Project description:In this study we provide evidence on potential mechanisms involved in H2S mediated protection against VILI. H2S down-regulates genes that are involved in oxidative stress and pro-inflammatory cell responses. H2S regulates ECM remodelling, a mechanism which may contribute to H2S-mediated lung protection. In addition, H2S inhalation activates anti-apoptotic and anti-inflammatory genes, and genes controlling the vascular permeability. The functional relevance of Atf3 underscores the potential of H2S to limit lung injury. We utilized a microarray approach for large scale analysis of target genes in order to elucidate the therapeutic effects of H2S in VILI. This study demonstrates the influence of supplemental H2S on gene expression in a model of VILI. In addition to describing the genes differentially regulated in VILI, the present study focused on newly identified H2S target genes within several functional groups, including anti-inflammatory and anti-apoptotic pathways, regulation of extracellular matrix (ECM) remodelling and angiogenesis. Gene expression analysis of control group, allowed to breathe spontaneously synthetic air and mice ventilated with synthetic air or synthetic air with 80 ppm H2S for 6 hours.
Project description:In this study we provide evidence on potential mechanisms involved in H2S mediated protection against VILI. H2S down-regulates genes that are involved in oxidative stress and pro-inflammatory cell responses. H2S regulates ECM remodelling, a mechanism which may contribute to H2S-mediated lung protection. In addition, H2S inhalation activates anti-apoptotic and anti-inflammatory genes, and genes controlling the vascular permeability. The functional relevance of Atf3 underscores the potential of H2S to limit lung injury. We utilized a microarray approach for large scale analysis of target genes in order to elucidate the therapeutic effects of H2S in VILI. This study demonstrates the influence of supplemental H2S on gene expression in a model of VILI. In addition to describing the genes differentially regulated in VILI, the present study focused on newly identified H2S target genes within several functional groups, including anti-inflammatory and anti-apoptotic pathways, regulation of extracellular matrix (ECM) remodelling and angiogenesis.
Project description:Intracerebral haemorrhage accounts for about 10-15% of all strokes and is associated with high mortality and morbidity. No successful phase 3 clinical trials for this disorder have been completed. In the past 6 years, the number of preclinical and clinical studies focused on intracerebral haemorrhage has risen. Important advances have been made in animal models of this disorder and in our understanding of mechanisms underlying brain injury after haemorrhage. Several therapeutic targets have subsequently been identified that are now being pursued in clinical trials. Many clinical trials have been based on limited preclinical data, and guidelines to justify taking preclinical results to the clinic are needed.
Project description:The incidence of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is a common health problem in the clinic and is projected to increase in prevalence in the future. Mechanical ventilation is commonly used to provide respiratory support and has become indispensable in emergency and critical medicine. However, ventilator use can result in lung tissue damage, collectively termed ventilator-induced lung injury (VILI). In the present study, phosphoprotein profiling of blood and tissue samples from ventilated and non-ventilated mice was performed and key changes in protein levels and cell signaling during VILI were identified. Activation of the PI3K/AKT and mitogen activated protein kinase signaling pathways, in addition to changes in expression of cancer, inflammatory and cell-death related proteins were detected in response to mechanical ventilation. Focal adhesion-related protein levels and signaling pathways were also significantly altered in an injury model compared with control. VILI can affect patient mortality in ALI and ARDS cases, and no targeted treatment options currently exist. Identifying biomarkers and understanding the signaling pathways associated with VILI is critical for the development of future therapies.
Project description:Isolated perfused and ventilated BALB/c mouse lung model 3 conditions c-10cmH2O pressure ventilation 3h, LPS-10cmH2O pressure ventilation 3h in the presence of E. coli LPS in the perfusion buffer (3mg/kg), ov-overventilation with 25cmH2O pressure 3h
Project description:Recently, we have shown that inhalation of hydrogen sulfide (H2S) protects against ventilator-induced lung injury (VILI). In the present study, we aimed to determine the underlying molecular mechanisms of H2S-dependent lung protection by analyzing gene expression profiles in mice. C57BL/6 mice were subjected to spontaneous breathing or mechanical ventilation in the absence or presence of H2S (80 parts per million). Gene expression profiles were determined by microarray, sqRT-PCR and Western Blot analyses. The association of Atf3 in protection against VILI was confirmed with a Vivo-Morpholino knockout model. Mechanical ventilation caused a significant lung inflammation and damage that was prevented in the presence of H2S. Mechanical ventilation favoured the expression of genes involved in inflammation, leukocyte activation and chemotaxis. In contrast, ventilation with H2S activated genes involved in extracellular matrix remodelling, angiogenesis, inhibition of apoptosis, and inflammation. Amongst others, H2S administration induced Atf3, an anti-inflammatory and anti-apoptotic regulator. Morpholino mediated reduction of Atf3 resulted in elevated lung injury despite the presence of H2S. In conclusion, lung protection by H2S during mechanical ventilation is associated with down-regulation of genes related to oxidative stress and inflammation and up-regulation of anti-apoptotic and anti-inflammatory genes. Here we show that Atf3 is clearly involved in H2S mediated protection.
Project description:Isolated perfused and ventilated BALB/c mouse lung model 3 conditions c-10cmH2O pressure ventilation 3h, LPS-10cmH2O pressure ventilation 3h in the presence of E. coli LPS in the perfusion buffer (3mg/kg), ov-overventilation with 25cmH2O pressure 3h Keywords: parallel sample
Project description:Accumulating evidence indicates a central role for epigenetic modifications in the progression of stroke pathology. These epigenetic mechanisms are involved in complex and dynamic processes that modulate post-stroke gene expression, cellular injury response, motor function, and cognitive ability. Despite decades of research, stroke continues to be classified as a leading cause of death and disability worldwide with limited clinical interventions. Thus, technological advances in the field of epigenetics may provide innovative targets to develop new stroke therapies. This review presents the evidence on the impact of epigenomic readers, writers, and erasers in both ischemic and hemorrhagic stroke pathophysiology. We specifically explore the role of DNA methylation, DNA hydroxymethylation, histone modifications, and epigenomic regulation by long non-coding RNAs in modulating gene expression and functional outcome after stroke. Furthermore, we highlight promising pharmacological approaches and biomarkers in relation to epigenetics for translational therapeutic applications.
Project description:Acute kidney injury (AKI) due to renal ischemia reperfusion (IR) is a major clinical problem without effective therapy and is a significant and frequent cause of morbidity and mortality during the perioperative period. Although the pathophysiology of ischemic AKI is not completely understood, several important mechanisms of renal IR-induced AKI have been studied. Renal ischemia and subsequent reperfusion injury initiates signaling cascades mediating renal cell necrosis, apoptosis, and inflammation, leading to AKI. Better understanding of the molecular and cellular pathophysiological mechanisms underlying ischemic AKI will provide more targeted approach to prevent and treat renal IR injury. In this review, we summarize important mechanisms of ischemic AKI, including renal cell death pathways and the contribution of endothelial cells, epithelial cells, and leukocytes to the inflammatory response during ischemic AKI. Additionally, we provide some updated potential therapeutic targets for the prevention or treatment of ischemic AKI, including Toll-like receptors, adenosine receptors, and peptidylarginine deiminase 4. Finally, we propose mechanisms of ischemic AKI-induced liver, intestine, and kidney dysfunction and systemic inflammation mainly mediated by Paneth cell degranulation as a potential explanation for the high mortality observed with AKI.