Non-coding RNA in Endothelial-to-Mesenchymal Transition

Endothelial-to-mesenchymal transition (EndMT) is the process wherein endothelial cells lose their typical endothelial cell markers and functions and adopt a mesenchymal-like phenotype. EndMT is required for development of the cardiac valves, the pulmonary and dorsal aorta and arterial maturation, but activation of the EndMT program during adulthood is believed to contribute to several pathologies including organ fibrosis, cardiovascular disease and cancer. Non-coding RNAs, including microRNAs, long non-coding RNAs and circular RNAs, modulate EndMT during development and disease. Here, we review the mechanisms by which non-coding RNAs facilitate or inhibit EndMT during development and disease and provide a perspective on the therapeutic application of non-coding RNAs to treat fibroproliferative cardiovascular disease

Transient tissue priming via ROCK inhibition uncouples pancreatic cancer progression, sensitivity to chemotherapy, and metastasis

The emerging standard of care for patients with inoperable pancreatic cancer is a combination of cytotoxic drugs gemcitabine and Abraxane, but patient response remains moderate. Pancreatic cancer development and metastasis occur in complex settings, with reciprocal feedback from microenvironmental cues influencing both disease progression and drug response. Little is known about how sequential dual targeting of tumor tissue tension and vasculature before chemotherapy can affect tumor response. We used intravital imaging to assess how transient manipulation of the tumor tissue, or "priming," using the pharmaceutical Rho kinase inhibitor Fasudil affects response to chemotherapy. Intravital Förster resonance energy transfer imaging of a cyclin-dependent kinase 1 biosensor to monitor the efficacy of cytotoxic drugs revealed that priming improves pancreatic cancer response to gemcitabine/Abraxane at both primary and secondary sites. Transient priming also sensitized cells to shear stress and impaired colonization efficiency and fibrotic niche remodeling within the liver, three important features of cancer spread. Last, we demonstrate a graded response to priming in stratified patient-derived tumors, indicating that fine-tuned tissue manipulation before chemotherapy may offer opportunities in both primary and metastatic targeting of pancreatic cancer

A RhoA-FRET Biosensor Mouse for Intravital Imaging in Normal Tissue Homeostasis and Disease Contexts.

The small GTPase RhoA is involved in a variety of fundamental processes in normal tissue. Spatiotemporal control of RhoA is thought to govern mechanosensing, growth, and motility of cells, while its deregulation is associated with disease development. Here, we describe the generation of a RhoA-fluorescence resonance energy transfer (FRET) biosensor mouse and its utility for monitoring real-time activity of RhoA in a variety of native tissues in vivo. We assess changes in RhoA activity during mechanosensing of osteocytes within the bone and during neutrophil migration. We also demonstrate spatiotemporal order of RhoA activity within crypt cells of the small intestine and during different stages of mammary gestation. Subsequently, we reveal co-option of RhoA activity in both invasive breast and pancreatic cancers, and we assess drug targeting in these disease settings, illustrating the potential for utilizing this mouse to study RhoA activity in vivo in real time

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Expression and functional analysis of notch signalling during cardiac development with special focus on the epicardium and coronary vasculature

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 29-04-2011The Notch pathway is a cell-to-cell signalling pathway conserved from invertebrates to humans. The pattern of Notch1 transcription during embryonic development has been extensively characterized (Del Amo et al., 1992; Reaume et al., 1992; Weinmaster et al., 1991). However, Notch receptor activation depends on where the ligands are expressed and on the expression of proteins that modify the receptor, such as Fringe. In the first part of this PhD project we have shown that our staining method to detect the active Notch1 receptor (N1ICD) using the V1744 antibody is a useful tool for the comparative analysis of Notch1 activity and function during mouse development. We described in detail the expression pattern of N1ICD focusing our attention on the cardiovascular system. Even more, 3D reconstruction analysis confirmed the pattern described in 2D. Trying to understand the restriction pattern showed by N1ICD in the endocardium, we carried out expression analysis of the Delta4 and Jagged1 ligands as well as Fringe genes during the early stages of cardiovascular development in order to determine which were responsible for the restriction of the activation. Results conclude that a complex balance between these elements regulate Notch1 receptor activation. Our expression analysis also showed that N1CD is expressed in the coronary vessels, prompting us to study the expression and function of Notch in epicardial and coronary vessel development. The expression analysis of the Notch pathway elements determined that the pathway is present in all the steps and cell types during the epicardial linage development. Functional analysis using RBPJk standard mutants conclude that the Notch pathway is inhibiting the cardiogenesis in the pericardial mesoderm region. Later in development, Notch ablation in the epicardial cell lineage disrupts coronary vessel development, specifically affecting the differentiation of arterial coronary endothelium and muscularization of the vessel wall. Loss of epicardial Notch signalling also impairs compact myocardium growth. Ectopic N1ICD expression impairs epicardium development affecting normal compact myocardium growth

Fibrosis and inflammation in tissue pathophysiology

In adult mammals, tissue damage activates a wound healing response with acute inflammation followed by either complete repair (for low-grade damage or in highly regenerative tissues, such as the liver) or replacement fibrosis (for extensive damage or in poorly regenerative tissues, such as the myocardium). Persistent damage and repeated insults sustain continuous activation of repair pathways leading to chronic inflammation, progressive tissue fibrosis and sclerosis. Despite the evolutionary advantage conferred by scarring as a rapid repair mechanism, chronic fibrosis leads to tissue adverse remodeling and impaired function. Persistent low-level inflammation and fibrosis are observed in many pathological conditions (e.g. hypertension, obesity, diabetes, genetic diseases), and lead to further complications including atherosclerosis and ischemic events, organ failure, autoimmune diseases, cancer, aging, and reduced resilience to infectious diseases. Pathological fibrosis plays a major role in a wide range of diseases, accounting for an increasingly large fraction of mortality cases worldwide. While recent advances have unveiled many environmental and genetic causes of fibrotic disorders, a better understanding of both ubiquitous and tissue-specific regulatory pathways and cellular dynamics could help to design new targeted therapies, and to identify the etiology of idiopathic diseases. Within this Research Topic, we invite submission of articles (reviews, original research, or methodology articles) on the pathophysiological role of fibrosis and inflammation in different tissues. Areas to be covered include, but are not limited to: - genetic and environmental causes of persistent low-level inflammation and fibrosis (e.g. autoimmunity, hypertension, obesity, diabetes, genetic diseases, latent infections); - comorbidities including systemic sclerosis, neurological disorders, organ failure (heart, skeletal muscle, kidney, liver, lungs), cancer, and reduced resilience to infectious diseases; - in vivo (animal models) and in vitro (organoids, tissue culture) modelling of fibrotic diseases for the discovery of novel therapeutic targets and potential tissue-specific treatments; - vascular responses to inflammation and inflammation of vascular tissues; - system biology approaches to identify molecular and cellular networks leading to chronic inflammation and fibrosis

Transient tissue priming via ROCK inhibition uncouples pancreatic cancer progression, sensitivity to chemotherapy, and metastasis

The emerging standard of care for patients with inoperable pancreatic cancer is a combination of cytotoxic drugs gemcitabine and Abraxane, but patient response remains moderate. Pancreatic cancer development and metastasis occur in complex settings, with reciprocal feedback from microenvironmental cues influencing both disease progression and drug response. Little is known about how sequential dual targeting of tumor tissue tension and vasculature before chemotherapy can affect tumor response. We used intravital imaging to assess how transient manipulation of the tumor tissue, or priming, using the pharmaceutical Rho kinase inhibitor Fasudil affects response to chemotherapy. Intravital Förster resonance energy transfer imaging of a cyclin-dependent kinase 1 biosensor to monitor the efficacy of cytotoxic drugs revealed that priming improves pancreatic cancer response to gemcitabine/Abraxane at both primary and secondary sites. Transient priming also sensitized cells to shear stress and impaired colonization efficiency and fibrotic niche remodeling within the liver, three important features of cancer spread. Last, we demonstrate a graded response to priming in stratified patient-derived tumors, indicating that fine-Tuned tissue manipulation before chemotherapy may offer opportunities in both primary and metastatic targeting of pancreatic cancer