The action of Nutraceuticals on key macrophage processes associated with Atherosclerosis

Objectives: To investigate the actions of nutraceuticals on key macrophage processes associated with atherosclerosis. Background: Atherosclerosis is an inflammatory disorder of the vasculature orchestrated by the action of cytokines. Macrophages play a pivotal role in atherosclerosis and represent promising therapeutic targets. Current therapies against atherosclerosis are associated with substantial residual risk together with other issues such as adverse side effects. In addition, there have been numerous disappointments on many pharmaceutical agents identified from drug discovery programs. This has initiated interest in nutraceuticals as preventative or therapeutic agents in atherosclerosis but requires an in-depth understanding of their actions. The purpose of this study was to delineate the effects of nutraceuticals on key macrophage processes associated with atherosclerosis together with the molecular mechanisms underlying their actions. Methods: The studies used a combination of macrophage cell lines and primary cultures. Gene expression was monitored by real time quantitative PCR and western blot analysis. The production of reactive oxygen species was determined using a kit from Abcam. Foam cell formation was monitored by uptake of fluorescently labeled modified LDL, intracellular lipid profile and cholesterol efflux. Inflammasome activation was evaluated by following the release of interleukin (IL)-1beta. Cell viability was assessed by release of lactate dehydrogenase. Results: The studies focused on key components in olive oil and omega-6 polyunsaturated fatty acids. These attenuated the expression of key markers of inflammation induced by several pro-atherogenic cytokines, the uptake of modified LDL, macropinocytosis and foam cell formation in macrophages. In addition, they stimulated macrophage cholesterol efflux. A differential effect was observed for other parameters such as production of reactive oxygen species and production of IL-1beta via inflammasome activation. The mechanisms underlying such actions will be presented. Conclusions: The studies provide novel insights into the actions of nutraceuticals on key macrophage pprocesses associated with atherosclerosisroce

Pro-atherogenic actions of signal transducer and activator of transcription 1 serine 727 phosphorylation in LDL receptor deficient mice via modulation of plaque inflammation

Atherosclerosis is a chronic inflammatory disorder of the vasculature regulated by cytokines. We have previously shown that extracellular signal-regulated kinase-1/2 (ERK1/2) plays an important role in serine 727 phosphorylation of signal transducer and activator of transcription-1 (STAT1) transactivation domain, which is required for maximal interferon-γ signaling, and the regulation of modified LDL uptake by macrophages in vitro. Unfortunately, the roles of ERK1/2 and STAT1 serine 727 phosphorylation in atherosclerosis are poorly understood and were investigated using ERK1 deficient mice (ERK2 knockout mice die in utero) and STAT1 knock-in mice (serine 727 replaced by alanine; STAT1 S727A). Mouse Atherosclerosis RT² Profiler PCR Array analysis showed that ERK1 deficiency and STAT1 S727A modification produced significant changes in the expression of 18 and 49 genes, respectively, in bone marrow-derived macrophages, with 17 common regulated genes that included those that play key roles in inflammation and cell migration. Indeed, ERK1 deficiency and STAT1 S727A modification attenuated chemokine-driven migration of macrophages with the former also impacting proliferation and the latter phagocytosis. In LDL receptor deficient mice fed a high fat diet, both ERK1 deficiency and STAT1 S727A modification produced significant reduction in plaque lipid content, albeit at different time points. The STAT1 S727A modification additionally caused a significant reduction in plaque content of macrophages and CD3 T cells and diet-induced cardiac hypertrophy index. In addition, there was a significant increase in plasma IL-2 levels and a trend toward increase in plasma IL-5 levels. These studies demonstrate important roles of STAT1 S727 phosphorylation in particular in the regulation of atherosclerosis-associated macrophage processes in vitro together with plaque lipid content and inflammation in vivo, and support further assessment of its therapeutical potential

Concordance of B- and T-cell responses to SARS-CoV-2 infection, irrespective of symptoms suggestive of COVID-19

This study assessed T‐cell responses in individuals with and without a positive antibody response to SARS‐CoV‐2, in symptomatic and asymptomatic individuals during the COVID‐19 pandemic. Participants were drawn from the TwinsUK cohort, grouped by (a) presence or absence of COVID‐associated symptoms (S+, S−), logged prospectively through the COVID Symptom Study app, and (b) anti‐IgG Spike and anti‐IgG Nucleocapsid antibodies measured by ELISA (Ab+, Ab−), during the first wave of the UK pandemic. T‐cell helper and regulatory responses after stimulation with SARS‐CoV‐2 peptides were assessed. Thirty‐two participants were included in the final analysis. Fourteen of 15 with IgG Spike antibodies had a T‐cell response to SARS‐CoV‐2‐specific peptides; none of 17 participants without IgG Spike antibodies had a T‐cell response (χ (2): 28.2, p < 0.001). Quantitative T‐cell responses correlated strongly with fold‐change in IgG Spike antibody titer (ρ = 0.79, p < 0.0001) but not to symptom score (ρ = 0.17, p = 0.35). Humoral and cellular immune responses to SARS‐CoV‐2 are highly correlated. We found no evidence of cellular immunity suggestive of SARS‐CoV2 infection in individuals with a COVID‐19‐like illness but negative antibodies