Dysregulated plasma lipid mediator profiles in critically ill COVID-19 patients.

Coronavirus disease (COVID)-19, as a result of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, has been the direct cause of over 2.2 million deaths worldwide. A timely coordinated host-immune response represents the leading driver for restraining SARS-CoV-2 infection. Indeed, several studies have described dysregulated immunity as the crucial determinant for critical illness and the failure of viral control. Improved understanding and management of COVID-19 could greatly reduce the mortality and morbidity caused by SARS-CoV-2. One aspect of the immune response that has to date been understudied is whether lipid mediator production is dysregulated in critically ill patients. In the present study, plasma from COVID-19 patients with either severe disease and those that were critically ill was collected and lipid mediator profiles were determined using liquid chromatography tandem mass spectrometry. Results from these studies indicated that plasma concentrations of both pro-inflammatory and pro-resolving lipid mediator were reduced in critically ill patients when compared with those with severe disease. Furthermore, plasma concentrations of a select group of mediators that included the specialized pro-resolving mediators (SPM) Resolvin (Rv) D1 and RvE4 were diagnostic of disease severity. Interestingly, peripheral blood SPM concentrations were also linked with outcome in critically ill patients, where we observed reduced overall concentrations of these mediators in those patients that did not survive. Together the present findings establish a link between plasma lipid mediators and disease severity in patients with COVID-19 and indicate that plasma SPM concentrations may be linked with survival in these patients

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

How Do They Do It? – Understanding the Success of Marine Invasive Species

From the depths of the oceans to the shallow estuaries and wetlands of our coasts, organisms of the marine environment are teeming with unique adaptations to cope with a multitude of varying environmental conditions. With millions of years and a vast volume of water to call their home, they have become quite adept at developing specialized and unique techniques for survival and – given increasing human mediated transport – biological invasions. A growing world human population and a global economy drives the transportation of goods across the oceans and with them invasive species via ballast water and attached to ship hulls. In any given 24-hour period, there are about 10,000 species being transported across different biogeographic regions. If any of them manage to take hold and establish a range in an exotic habitat, the implications for local ecosystems can be costly. This review on marine invasions highlights trends among successful non-indigenous species (NIS), from vectors of transport to ecological and physiological plasticity. Apart from summarizing patterns of successful invasions, it discusses the implications of how successfully established NIS impact the local environment, economy and human health. Finally, it looks to the future and discusses what questions need to be addressed and what models can tell us about what the outlook on future marine invasions is

Postprandial response of adiponectin, interleukin-6, tumor necrosis factor-α, and C-reactive protein to a high-fat dietary load

Objective: Circulating levels of adiponectin are low in obesity and metabolic disorders associated with increasing fat mass including insulin resistance and dyslipidemia. Body fat stores may be positively related to intake of dietary fat, but little is known of mechanisms by which serum adiponectin may be regulated through diet. We investigated acute effects of a high-fat load and changes in fatty acid saturation on circulating adiponectin and associated mediators of inflammation including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP). Methods: A high-fat test meal (59 ± 4 g fat; 71% of energy as fat) containing a high (∼71:29) or low (∼55:45) ratio of saturated:unsaturated fatty acids was given at breakfast on two occasions. Blood samples were collected at 0 (baseline), 1, 3, and 6 h for measurement of adiponectin, IL-6, TNF-α, and high-sensitivity CRP. A fat-exclusion lunch, snack, and dinner were also given and blood samples collected at 10 and 24 h. Results: Eighteen healthy, lean men completed the trial. There was no evidence of acute change in circulating adiponectin in response to the lipid bolus or a differential effect of fatty acid saturation on adiponectin, high-sensitivity CRP, or IL-6 (P > 0.05). IL-6 increased over 6 h on both treatments (time, P < 0.05). TNF-α decreased on the high saturated:unsaturated fatty acid treatment (treatment by time, P < 0.05). There were no significant correlations between circulating adiponectin and insulin on either dietary treatment in these normoglycemic subjects. Conclusion: Acute changes in the content of saturated and unsaturated fatty acids had no adverse effect on postprandial circulation of the adipose-related factors adiponectin, IL-6, TNF-α, or high-sensitivity CRP. © 2008 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex

Effect of high-fat meals and fatty acid saturation on postprandial levels of the hormones ghrelin and leptin in healthy men

Objective: Ghrelin and leptin play a role in control of food intake and adiposity but mechanisms regulating these hormones in man are poorly defined and evidence that dietary fats may have adverse effects is inconclusive. We investigated whether high-fat meals, which differed in saturated fatty acid (SFA) content acutely modified these hormones. Design: Randomised, double-blind, crossover trial. A high-fat (HF) test meal (59± 4 g fat; 71% of energy as fat) was given for breakfast on two occasions. Meals comprised either high (∼70:30) or low (∼ 55:45) saturated:unsaturated fatty acid (SFA:USFA) ratio. Fasting and postprandial measurements of serum total ghrelin (RIA), leptin (enzyme-linked immunosorbent assay (ELISA)) and insulin (RIA) were made over 6 h. Postprandial measurements were also made at 10 and 24 h following a fat-exclusion lunch, snack and dinner. Subjects: A total of 18 lean, healthy men. Results: There was no significant effect of the fatty meal (time, P>0.05), nor a differential effect of SFA:USFA ratio (treatment *time, P>0.05) on ghrelin over 6 h. Leptin decreased in response to both HF treatments (time, P0.05). There was no significant correlation between ghrelin or leptin and circulating insulin (P>0.05). Conclusion: We conclude that HF diets may adversely effect serum leptin, although the circadian decrease may account in part for this response. Increasing dietary SFAs had no deleterious effects on leptin or total ghrelin. © 2006 Nature Publishing Group. All rights reserved.link_to_subscribed_fulltex