Sera from patients with Kawasaki disease induce intercellular adhesion molecule-1 but not Fas in human endothelial cells

Cellular and Molecular Pathways of COVID-19 and Potential Points of Therapeutic Intervention

With the objective of linking early findings relating to the novel SARS-CoV-2 coronavirus with potentially informative findings from prior research literature and to promote investigation toward therapeutic response, a coherent cellular and molecular pathway is proposed for COVID-19. The pathway is consistent with a broad range of observed clinical features and biological markers and captures key mediators of pathophysiology. In this proposed pathway, membrane fusion and cytoplasmic entry of SARS-CoV-2 virus via ACE2 and TMPRSS2-expressing respiratory epithelial cells, including pulmonary type-II pneumocytes, provoke an initial immune response featuring inflammatory cytokine production coupled with a weak interferon response, particularly in IFN-λ-dependent epithelial defense. Differentiation of non-classic pathogenic T-cells and pro-inflammatory intermediate monocytes contributes to a skewed inflammatory profile, mediated by membrane-bound immune receptor subtypes (e.g., FcγRIIA) and downstream signaling pathways (e.g., NF-κB p65 and p38 MAPK), followed by chemotactic infiltration of monocyte-derived macrophages and neutrophils into lung tissue. Endothelial barrier degradation and capillary leakage contribute to alveolar cell damage. Inflammatory cytokine release, delayed neutrophil apoptosis, and NETosis contribute to pulmonary thrombosis and cytokine storm. These mechanisms are concordant with observed clinical markers in COVID-19, including high expression of inflammatory cytokines on the TNF-α/IL-6 axis, elevated neutrophil-to-lymphocyte ratio (NLR), diffuse alveolar damage via cell apoptosis in respiratory epithelia and vascular endothelia, elevated lactate dehydrogenase (LDH) and CRP, high production of neutrophil extracellular traps (NETs), depressed platelet count, and thrombosis. Although certain elements are likely to be revised as new findings emerge, the proposed pathway suggests multiple points of investigation for potential therapeutic interventions. Initial candidate interventions include prophylaxis to augment epithelial defense (e.g., AT1 receptor blockade, type III and type I interferons, melatonin, calcitriol, camostat, and lopinavir) and to reduce viral load (e.g., remdesivir, ivermectin, emetine, Abelson kinase inhibitors, dopamine D2 antagonists, and selective estrogen receptor modulators). Additional interventions focus on tempering inflammatory signaling and injury (e.g., dexamethasone, doxycycline, Ang1-7, estradiol, alpha blockers, and DHA/EPA, pasireotide), as well as inhibitors targeted toward molecular mediators of the maladaptive COVID-19 immune response (e.g., IL-6, TNF-α, IL-17, JAK, and CDK9).

The role of Ca2+/NFAT in Dysfunction and Inflammation of Human Coronary Endothelial Cells induced by Sera from patients with Kawasaki disease

Ca²⁺/nuclear factor of activated T-cells (Ca²⁺/NFAT) signaling pathway may play a crucial role in the pathogenesis of Kawasaki disease (KD). We investigated the poorly understood Ca²⁺/NFAT regulation of coronary artery endothelial cells and consequent dysfunction in KD pathogenesis. Human coronary artery endothelial cells (HCAECs) stimulated with sera from patients with KD, compared with sera from healthy children, exhibited significant increases in proliferation and angiogenesis, higher levels of NFATc1 and NFATc3 and some inflammatory molecules, and increased nuclear translocation of NFATc1 and NFATc3. HCAECs stimulated with sera from patients with KD treated with cyclosporine A (CsA) showed decreased proliferation, angiogenesis, NFATc1 and inflammatory molecules levels as compared with results for untreated HCAECs. In conclusion, our data reveal that KD sera activate the Ca²⁺/NFAT in HCAECs, leading to dysfunction and inflammation of endothelial cells. CsA has cytoprotective effects by ameliorating endothelial cell homeostasis via Ca²⁺/NFAT.

Endothelial Response to Glucocorticoids in Inflammatory Diseases

The endothelium plays a crucial role in inflammation. A balanced control of inflammation requires the action of glucocorticoids (GCs), steroidal hormones with potent cell-specific anti-inflammatory properties. Besides the classic anti-inflammatory effects of GCs on leukocytes, recent studies confirm that endothelial cells also represent an important target for GCs. GCs regulate different aspects of endothelial physiology including expression of adhesion molecules, production of pro-inflammatory cytokines and chemokines, and maintenance of endothelial barrier integrity. However, the regulation of endothelial GC sensitivity remains incompletely understood. In this review, we specifically examine the endothelial response to GCs in various inflammatory diseases ranging from multiple sclerosis, stroke, sepsis, and vasculitis to atherosclerosis. Shedding more light on the cross talk between GCs and endothelium will help to improve existing therapeutic strategies and develop new therapies better tailored to the needs of patients.

Kawasaki disease: infection, immunity and genetics

Kawasaki disease is an acute multisystem vasculitic syndrome of unknown etiology occurring mostly in infants and children younger than 5 years of age. In developed countries, Kawasaki disease is currently the leading cause of acquired heart diseases in children. However, it is still a mysterious disease. In this article, we reviewed and summarized from the aspects based on infection agents, host immune dysregulation and genetic background intended to establish a feasible infection-immunogenetic pathogenesis for this mysterious disease and also provided the rational strategy to explore optimal treatment of this disease.