IFN-gamma regulation of ICAM-1 receptors in bronchial epithelial cells: soluble ICAM-1 release inhibits human rhinovirus infection

Cytokine storm-based mechanisms for extrapulmonary manifestations of SARS-CoV-2 infection

Viral illnesses like SARS-CoV-2 have pathologic effects on nonrespiratory organs in the absence of direct viral infection. We injected mice with cocktails of rodent equivalents of human cytokine storms resulting from SARS-CoV-2/COVID-19 or rhinovirus common cold infection. At low doses, COVID-19 cocktails induced glomerular injury and albuminuria in zinc fingers and homeoboxes 2 (Zhx2) hypomorph and Zhx2+/+ mice to mimic COVID-19-related proteinuria. Common Cold cocktail induced albuminuria selectively in Zhx2 hypomorph mice to model relapse of minimal change disease, which improved after depletion of TNF-α, soluble IL-4Rα, or IL-6. The Zhx2 hypomorph state increased cell membrane to nuclear migration of podocyte ZHX proteins in vivo (both cocktails) and lowered phosphorylated STAT6 activation (COVID-19 cocktail) in vitro. At higher doses, COVID-19 cocktails induced acute heart injury, myocarditis, pericarditis, acute liver injury, acute kidney injury, and high mortality in Zhx2+/+ mice, whereas Zhx2 hypomorph mice were relatively protected, due in part to early, asynchronous activation of STAT5 and STAT6 pathways in these organs. Dual depletion of cytokine combinations of TNF-α with IL-2, IL-13, or IL-4 in Zhx2+/+ mice reduced multiorgan injury and eliminated mortality. Using genome sequencing and CRISPR/Cas9, an insertion upstream of ZHX2 was identified as a cause of the human ZHX2 hypomorph state.

Biomarkers of Airway Immune Homeostasis Differ Significantly with Generation of E-Cigarettes

Rationale: Numerous studies have demonstrated that e-cigarettes can impact respiratory immune homeostasis; however, the extent of these effects remains an active area of investigation, and most previous studies were conducted with model systems or subjects exposed to third-generation e-cigarettes, such as vape pens and box mods. Objectives: Given the rise in popularity of nicotine-salt-containing pods and disposable e-cigarettes (fourth generation), we set out to better understand the respiratory effects of these newer e-cigarettes and compare their effects to early-generation devices. Methods: We collected induced sputum samples from a cohort of nonsmokers, smokers, third-generation e-cigarette users, and fourth-generation e-cigarette users (n = 20-30 per group) and evaluated the cellular and fluid-phase composition for markers of inflammation, host defense, and lung injury. Measurements and Main Results: Fourth-generation e-cigarette users had significantly more bronchial epithelial cells in the sputum, suggestive of airway injury. Concentrations of soluble intercellular adhesion molecule 1 (sICAM1) and soluble vascular cell adhesion molecule 1 (sVCAM1) were significantly lower in fourth-generation e-cigarette users in comparison with all other groups, and CRP (C-reactive protein), IFN-γ, MCP-1 (monocyte chemoattractant protein-1), MMP-2 (matrix metalloproteinase 2), uteroglobin, and VEGF (vascular endothelial growth factor) were significantly lower in fourth- versus third-generation e-cigarette users, suggestive of overall immune suppression in fourth-generation e-cigarette users. Predictive modeling also demonstrated clear separation between exposure groups, indicating that the overall mediator milieu is different between groups, particularly fourth-generation e-cigarette users. Conclusions: Our results indicate disrupted immune homeostasis in fourth-generation e-cigarette users and demonstrate that the biological effects of fourth-generation e-cigarette use are unique compared with those associated with previous-generation e-cigarettes.

Antiviral activity and possible mechanism of action of constituents identified in Paeonia lactiflora root toward human rhinoviruses

Human rhinoviruses (HRVs) are responsible for more than half of all cases of the common cold and cost billions of USD annually in medical visits and missed school and work. An assessment was made of the antiviral activities and mechanisms of action of paeonol (PA) and 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose (PGG) from Paeonia lactiflora root toward HRV-2 and HRV-4 in MRC5 cells using a tetrazolium method and real-time quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Results were compared with those of a reference control ribavirin. Based on 50% inhibitory concentration values, PGG was 13.4 and 18.0 times more active toward HRV-2 (17.89 μM) and HRV-4 (17.33 μM) in MRC5 cells, respectively, than ribavirin. The constituents had relatively high selective index values (3.3->8.5). The 100 μg/mL PA and 20 μg/mL PGG did not interact with the HRV-4 particles. These constituents inhibited HRV-4 infection only when they were added during the virus inoculation (0 h), the adsorption period of HRVs, but not after 1 h or later. Moreover, the RNA replication levels of HRVs were remarkably reduced in the MRC5 cultures treated with these constituents. These findings suggest that PGG and PA may block or reduce the entry of the viruses into the cells to protect the cells from the virus destruction and abate virus replication, which may play an important role in interfering with expressions of rhinovirus receptors (intercellular adhesion molecule-1 and low-density lipoprotein receptor), inflammatory cytokines (interleukin (IL)-6, IL-8, tumor necrosis factor, interferon beta, and IL-1β), and Toll-like receptor, which resulted in diminishing symptoms induced by HRV. Global efforts to reduce the level of synthetic drugs justify further studies on P. lactiflora root-derived materials as potential anti-HRV products or lead molecules for the prevention or treatment of HRV.

Intercellular adhesion molecule-1 as a drug target in asthma and rhinitis

Intercellular adhesion molecule-1 (ICAM-1) is a transmembrane glycoprotein receptor of the immunoglobulin superfamily. Endothelial cells, epithelial cells, leukocytes and neutrophils are the major cells expressing ICAM-1. Ligands of ICAM-1 are macrophage adhesion ligand-1, leukocyte function-associated antigen-1 and fibrinogen (extracellular matrix protein). In normal physiological conditions, engagement of ICAM-1 receptor with immunological cells surface ligands assists in homing and trafficking of inflammatory cells to distant tissues. ICAM-1 has also long been known to mediate cell-to-cell interaction during antigen presentation and outside-in cell signalling pathways. ICAM-1-mediated elevated inflammation is implicated in asthma. On respiratory epithelial cells surface, ICAM-1 acts as natural binding site for human rhinovirus (HRV), a common cold virus that ultimately causes exacerbation of asthma. This review presents the findings on the role of ICAM-1 in the complication of asthma and in particular asthma exacerbation by HRV.

Intercellular adhesion molecule 1: recent findings and new concepts involved in mammalian spermatogenesis

Spermatogenesis, the process of spermatozoa production, is regulated by several endocrine factors, including testosterone, follicle stimulating hormone, luteinizing hormone and estradiol 17β. For spermatogenesis to reach completion, developing germ cells must traverse the seminiferous epithelium while remaining transiently attached to Sertoli cells. If germ cell adhesion were to be compromised for a period of time longer than usual, germ cells would slough from the seminiferous epithelium and infertility would result. Presently, Sertoli-germ cell adhesion is known to be mediated largely by classical and desmosomal cadherins. More recent studies, however, have begun to expand long-standing concepts and to examine the roles of other proteins such as intercellular adhesion molecules. In this review, we focus on the biology of intercellular adhesion molecules in the mammalian testis, hoping that this information is useful in the design of future studies.

Lung-targeted overexpression of the NF-κB member RelB inhibits cigarette smoke-induced inflammation

Acute lung inflammation can be caused by a variety of respirable agents, including cigarette smoke. Long-term cigarette smoke exposure can cause chronic obstructive pulmonary disease (COPD), a serious illness that affects >10 million Americans. Cigarette smoke is a known inducer of inflammation and is responsible for approximately 90% of all COPD cases. RelB, a member of the NF-κB family, attenuates cigarette smoke-induced inflammatory mediator production in mouse lung fibroblasts in vitro. We hypothesized that overexpression of RelB in the airways of mice would dampen acute smoke-induced pulmonary inflammation. Mice received a recombinant adenovirus encoding RelB by intranasal aspiration to induce transient RelB overexpression in the lungs and were subsequently exposed to mainstream cigarette smoke. Markers of inflammation were analyzed after smoke exposure. Neutrophil infiltration, normally increased by smoke exposure, was significantly and potently decreased after RelB overexpression. Cigarette smoke-induced proinflammatory cytokine and chemokine production, cyclooxygenase-2 expression, and prostaglandin E(2) production were also significantly decreased in the context of RelB overexpression. The expression of intercellular adhesion molecule 1, an NF-κB-dependent protein, was decreased, indicating a potential mechanism through which RelB can regulate inflammatory cell migration. Therefore, increased expression and/or activation of RelB could be a novel therapeutic strategy against acute lung inflammation caused by respirable agents and possibly against chronic injury, such as COPD.

Identification and pharmacological characterization of the anti-inflammatory principal of the leaves of dwarf elder (Sambucus ebulus L.)

AIM OF THE STUDY

The performed investigations aimed on the identification of the anti-inflammatory principal of extracts of leaves of Sambucus ebulus L. (dwarf elder) in order to rationalize the traditional use of this plant for the treatment of chronically inflammatory diseases.

MATERIALS AND METHODS

Dwarf elder leaf extract was subjected to activity guided fractionation using inhibition of TNFα induced expression of vascular cell adhesion molecule 1 (VCAM-1) on the surface of human umbilical vein endothelial cells (HUVECs) as monitoring tool (positive control: parthenolide 10μM, VCAM-1 expression (% of control): 5.35±0.38%).

RESULTS

Bio-guided isolation resulted in identification of ursolic acid as anti-inflammatory principal. Besides its inhibitory effects against TNFα induced expression of VCAM-1 (IC(50) 6.25 μM), ursolic acid inhibits also TNFα induced expression of ICAM-1 (IC(50) value between 3.13 and 6.25 μM) (positive control: parthenolide 10 μM, ICAM-1 expression (% of control): 38.89±16.6%). Toxic effects of ursolic acid on HUVECs can be drastically reduced using an enriched extract instead of the pure compound.

CONCLUSIONS

Our findings suggest an additional mechanism of the anti-inflammatory activity of ursolic acid by demonstrating its ability to inhibit TNFα-stimulated expression of VCAM-1 and ICAM-1 and support the traditional use of extracts and preparations of Sambucus ebulus L., rich in ursolic acid, for the treatment of chronically inflammatory processes.