The effects of nitric oxide (NO) from calcium-independent NO synthase (iNOS) on microvascular protein leak in acute lung injury (ALI) are uncertain, possibly because of disparate effects of iNOS-derived NO from different cells. We assessed the contribution of iNOS from inflammatory versus parenchymal cells to pulmonary protein leak in murine cecal ligation and perforation-induced ALI. We studied iNOS+/+, iNOS-/-, and two reciprocally bone marrow-transplanted iNOS chimeric mice groups: + to - (iNOS+/+ donor bone marrow-transplanted into iNOS-/- recipient mice) and - to +. Sepsis-induced ALI was characterized by pulmonary leukocyte infiltration, increased pulmonary iNOS activity, and increased pulmonary microvascular protein leak, as assessed by Evans blue (EB) dye. Despite equal neutrophil infiltration, sepsis-induced EB-protein leak was eliminated in iNOS-/- mice and in - to + iNOS chimeras (parenchymal cell-localized iNOS) but was preserved in + to - chimeric mice (inflammatory cell-localized iNOS). EB-protein leak was also prevented by pretreatment with allopurinol and superoxide dismutase. Microvascular protein leak in sepsis-induced ALI is uniquely dependent on iNOS in inflammatory cells with no obvious contribution of iNOS in pulmonary parenchymal cells. Pulmonary protein leak is also dependent on superoxide, suggesting an effect of peroxynitrite rather than NO itself.
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J Cardiovasc Electrophysiol
January 2025
Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China.
Ryanodine receptor 2 (RyR2) protein, a calcium ion release channel in the sarcoplasmic reticulum (SR) of myocardial cells, plays a crucial role in regulating cardiac systolic and diastolic functions. Mutations in RyR2 and its dysfunction are implicated in various congenital heart diseases (CHDs). Studies have shown that mutations in the RYR2 gene, which encodes the RyR2 protein, are linked to several cardiac arrhythmias, including catecholaminergic polymorphic ventricular tachycardia (CPVT), long QT syndrome (LQTS), calcium release deficiency syndrome (CRDS), and atrial fibrillation (AF).
View Article and Find Full Text PDFTransl Vis Sci Technol
January 2025
Yale Cardiovascular Research Center, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.
Purpose: Alteration of visual acuity in wet age-related macular degeneration (AMD) is mostly driven by vascular endothelial growth factor A (VEGF-A)-induced edema from leaky newly forming blood vessels below the retina layers. To date, all therapies aimed at alleviation of this process have relied on inhibition of VEGF-A activity. Although effective in preventing vascular leak and edema, this approach also leads to the loss of normal vasculature and multiple related side effects.
View Article and Find Full Text PDFBiol Open
January 2025
Department of Pulmonary Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
Epithelial cell cohesion and barrier function critically depend on α-catenin, an actin-binding protein and essential constituent of cadherin-catenin-based adherens junctions. α-catenin undergoes actomyosin force-dependent unfolding of both actin-binding and middle domains to strongly engage actin filaments and its various effectors; this mechanosensitivity is critical for adherens junction function. We previously showed that α-catenin is highly phosphorylated in an unstructured region that links the mechanosensitive middle and actin-binding domains (known as the P-linker region), but the cellular processes that promote α-catenin phosphorylation have remained elusive.
View Article and Find Full Text PDFJ Cutan Pathol
January 2025
Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital/Mass General Brigham, Boston, Massachusetts, USA.
The human body is composed mostly of water fortified by a variety of proteins, fats, carbohydrates, vitamins, minerals, and other nutrients, all organized into an elegant structurally complex and functionally efficient machine in which our consciousness resides. This heterogeneous assemblage of essential ingredients is enclosed in a container known as the integument, or simply, the skin. The container is as important as its contents; when itself devoid of structural and functional integrity, it will both leak as well as become infused with potentially harmful external agents.
View Article and Find Full Text PDFJ Abdom Wall Surg
December 2024
Anesthesiology and Critical Care Department, Pellegrin University Hospital, Bordeaux, France.
Introduction: In critically ill surgical patients treated with open abdomen and negative pressure therapy (OA/NPT), the association between nutritional support and clinical outcome is still controversial. The main objective of this study was to assess the effect of enteral nutritional support during the acute phase (i.e.
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