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SARS-CoV-2 can cause acute respiratory distress and death in some patients 1 . Although severe COVID-19 is linked to substantial inflammation, how SARS-CoV-2 triggers inflammation is not clear 2 . Monocytes and macrophages are sentinel cells that sense invasive infection to form inflammasomes that activate caspase-1 and gasdermin D, leading to inflammatory death (pyroptosis) and the release of potent inflammatory mediators 3 . Here we show that about 6% of blood monocytes of patients with COVID-19 are infected with SARS-CoV-2. Monocyte infection depends on the uptake of antibody-opsonized virus by Fcγ receptors. The plasma of vaccine recipients does not promote antibody-dependent monocyte infection. SARS-CoV-2 begins to replicate in monocytes, but infection is aborted, and infectious virus is not detected in the supernatants of cultures of infected monocytes. Instead, infected cells undergo pyroptosis mediated by activation of NLRP3 and AIM2 inflammasomes, caspase-1 and gasdermin D. Moreover, tissue-resident macrophages, but not infected epithelial and endothelial cells, from lung autopsies from patients with COVID-19 have activated inflammasomes. Taken together, these findings suggest that antibody-mediated SARS-CoV-2 uptake by monocytes and macrophages triggers inflammatory cell death that aborts the production of infectious virus but causes systemic inflammation that contributes to COVID-19 pathogenesis., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Complement plays an important role in the pathogenesis of rheumatoid arthritis. Although the alternative pathway (AP) is known to play a key pathogenic role in models of rheumatoid arthritis, the importance of the lectin pathway (LP) pattern recognition molecules such as ficolin (FCN) A, FCN B, and collectin (CL)-11, as well as the activating enzyme mannose-binding lectin-associated serine protease-2 (MASP-2), are less well understood. We show in this article that FCN A -/- and CL-11 -/- mice are fully susceptible to collagen Ab-induced arthritis (CAIA). In contrast, FCN B -/- and MASP-2 -/- /sMAp -/- mice are substantially protected, with clinical disease activity decreased significantly ( p < 0.05) by 47 and 70%, respectively. Histopathology scores, C3, factor D, FCN B deposition, and infiltration of synovial macrophages and neutrophils were similarly decreased in FCN B -/- and MASP-2 -/- /sMAp -/- mice. Our data support that FCN B plays an important role in the development of CAIA, likely through ligand recognition in the joint and MASP activation, and that MASP-2 also contributes to the development of CAIA, likely in a C4-independent manner. Decreased AP activity in the sera from FCN B -/- and MASP-2 -/- /sMAp -/- mice with arthritis on adherent anti-collagen Abs also support the hypothesis that pathogenic Abs, as well as additional inflammation-related ligands, are recognized by the LP and operate in vivo to activate complement. Finally, we also speculate that the residual disease seen in our studies is driven by the AP and/or the C2/C4 bypass pathway via the direct cleavage of C3 through an LP-dependent mechanism., (Copyright © 2017 by The American Association of Immunologists, Inc.)

Following our recent discovery of a new scaffold exhibiting significant neurotrophic and neurogenic activities, a structurally tweaked analogue, embodying a 2-oxa-spiro [5.4]decane framework, has been conceptualised and found to be more potent and versatile. It exhibits enhanced neurotrophic and neurogenic action in in vitro, ex vivo and in vivo models and also shows robust neuroprotection in mouse acute cerebral stroke model. The observed attributes are traceable to the predominant activation of the TrkB-PI3K-AKT-CREB pathway. In addition, it also exhibits remarkable anti-neuroinflammatory activity by concurrently down-regulating pro-inflammatory cytokines IL-1α and IL-6, thereby providing a unique molecule with a trinity of neuroactivities, i.e. neurotrophic, neurogenic and anti-inflammatory. The new chemical entity disclosed here has the potential to be advanced as a versatile therapeutic molecule to treat stroke, depression, and possibly other neuropsychiatric disorders associated with attenuated neurotrophic/ neurogenic activity, together with heightened neuroinflammation.

Background & Aims: Non-selective beta blockers (NSBBs) have been shown to have deleterious outcomes in patients with refractory ascites, alcoholic hepatitis and spontaneous bacterial peritonitis leading many physicians to stop the drug in these cases. Acute-on-chronic liver failure (ACLF) is characterized by systemic inflammation and high mortality. As NSBBs may have beneficial effects on gut motility and permeability and, systemic inflammation, the aims of this prospective, observational study were to determine whether ongoing use of NSBBs reduced 28-day mortality in ACLF patients., Methods: The study was performed in 349 patients with ACLF included in the CANONIC study, which is a prospective observational investigation in hospitalized cirrhotic patients with acute deterioration. The data about the use of NSBBs, its type and dosage was specifically recorded. Patient characteristics at enrollment significantly associated with treatment and mortality were taken into account as potential confounders to adjust for treatment effect. A logistic regression model was fitted., Results: 164 (47%) ACLF patients received NSBBs whereas 185 patients did not. Although the CLIF-C ACLF scores were similar at presentation, more patients in the NSBB treated group had lower grades of ACLF (p=0.047) at presentation and significantly more patients improved. Forty patients (24.4%) died in NSBB treated group compared with 63 patients (34.1%) (p=0.048) [estimated risk-reduction 0.596 (95%CI: 0.361-0.985; p=0.0436)]. This improvement in survival was associated with a significantly lower white cell count (NSBB: 8.5 (5.8); no NSBB: 10.8 (6.6); p=0.002). No long-term improvement in survival was observed., Conclusions: This study shows for the first time that ongoing treatment with NSBBs in cirrhosis is safe and reduces the mortality if they develop ACLF. Careful thought should be given before stopping NSBBs in cirrhotic patients., (Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background & Aims: Liver failure is characterized by endothelial dysfunction, which results in hemodynamic disturbances leading to renal failure. Albumin infusion improves hemodynamics and prevents renal dysfunction in advance liver failure. These effects are only partly explained by the oncotic properties of albumin. This study was designed to test the hypothesis that albumin exerts its beneficial effects by stabilising endothelial function., Methods: In vivo: systemic hemodynamics, renal function, markers of endothelial dysfunction (ADMA) and inflammation were studied in analbuminaemic and Sprague-Dawley rats, 6-weeks after sham/bile duct ligation surgery. In vitro: human umbilical vein endothelial cells were stimulated with LPS with or without albumin. We studied protein expression and gene expression of adhesion molecules, intracellular reactive oxygen species, and cell stress markers., Results: Compared to controls, analbuminaemic rats had significantly greater hemodynamic deterioration after bile duct ligation, resulting in worse renal function and shorter survival. This was associated with significantly greater plasma renin activity, worse endothelial function, and disturbed inflammatory response. In vitro studies showed that albumin was actively taken up by endothelial cells. Incubation of albumin pre-treated endothelial cells with LPS was associated with significantly less activation compared with untreated cells, decreased intracellular reactive oxygen species, and markers of cell stress., Conclusions: These results show, for the first time, that absence of albumin is characterised by worse systemic hemodynamics, renal function and higher mortality in a rodent model of chronic liver failure and illustrates the important non-oncotic properties of albumin in protecting against endothelial dysfunction., (Copyright © 2015. Published by Elsevier B.V.)

Portal hypertension has traditionally been viewed as a progressive process, involving ultrastructural changes including fibrosis, nodule formation, and vascular thrombosis, leading to increased intrahepatic resistance to flow. However, it is increasingly recognized that a significant component of this vascular resistance results from a dynamic process, regulated by complex interactions between the injured hepatocyte, the sinusoidal endothelial cell, the Kupffer cell and the hepatic stellate cell, which impact on sinusoidal calibre. Recent findings suggest these haemodynamic findings are most marked in patients with superimposed inflammation. The precise mechanisms for vascular dysfunction in cirrhosis with superimposed inflammation remain to be fully elucidated but several studies over the past decade have started to generate the hypothesis that inflammation may be a key mediator of the pathogenesis and severity of portal hypertension in this context. This review provides a comprehensive overview of the biological mechanisms for inflammation playing a key role in the severity of portal hypertension, and illustrates potential novel therapies that act by modifying these processes., (Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background: Moderate alcohol consumption is thought to confer cardiometabolic protective effects. Inflammatory pathways are hypothesized to partly underlie this association.Objectives: The aim of this study was to examine the association between typologies of alcohol consumption and markers of inflammation, and their rate of change over time.Methods: Data were collected from 8209 participants [69% men; mean age, 50 years (SD 6.1)] of the British Whitehall II study. Alcohol consumption typologies were defined using up to three measures during an approximately 10-year period spanning from 1985 to 1994 as (i) stable nondrinkers, (ii) stable moderate drinkers (referent), (iii) stable heavy drinkers, (iv) nonstable drinkers and (v) former drinkers. C-reactive protein (CRP), interleukin (IL)-6 and IL-1 receptor antagonist (IL-1 RA) were measured up to three times in the following 12 years.Results: Stable moderate drinkers had lower levels of CRP than stable nondrinkers, stable heavy drinkers, former drinkers and nonstable drinkers, but there were no differences in the rate of change in CRP over time between groups. Stable nondrinkers had higher levels of IL-6 as did stable heavy drinkers; rates of change in IL-6 over time were also increased in the latter group. Stable nondrinkers also had higher levels of IL-1 RA. These associations were robust to adjustment for confounding factors.Conclusion: Our novel investigation of 10-year drinking typologies shows that stable moderate alcohol consumption is associated with a long-term inflammatory marker profile that is consistent with conferring a reduced risk of developing coronary heart disease. [ABSTRACT FROM AUTHOR]