Neutrophils are innate immune phagocytes that have a central role in immune defence. Our understanding of the role of neutrophils in pathogen clearance, immune regulation and disease pathology has advanced dramatically in recent years. Web-like chromatin structures known as neutrophil extracellular traps (NETs) have been at the forefront of this renewed interest in neutrophil biology. The identification of molecules that modulate the release of NETs has helped to refine our view of the role of NETs in immune protection, inflammatory and autoimmune diseases and cancer. Here, I discuss the key findings and concepts that have thus far shaped the field of NET biology.

Neutrophil extracellular traps in immunity and disease

The world is in the grip of the COVID-19 pandemic. Public health measures that can reduce the risk of infection and death in addition to quarantines are desperately needed. This article reviews the roles of vitamin D in reducing the risk of respiratory tract infections, knowledge about the epidemiology of influenza and COVID-19, and how vitamin D supplementation might be a useful measure to reduce risk. Through several mechanisms, vitamin D can reduce risk of infections. Those mechanisms include inducing cathelicidins and defensins that can lower viral replication rates and reducing concentrations of pro-inflammatory cytokines that produce the inflammation that injures the lining of the lungs, leading to pneumonia, as well as increasing concentrations of anti-inflammatory cytokines. Several observational studies and clinical trials reported that vitamin D supplementation reduced the risk of influenza, whereas others did not. Evidence supporting the role of vitamin D in reducing risk of COVID-19 includes that the outbreak occurred in winter, a time when 25-hydroxyvitamin D (25(OH)D) concentrations are lowest; that the number of cases in the Southern Hemisphere near the end of summer are low; that vitamin D deficiency has been found to contribute to acute respiratory distress syndrome; and that case-fatality rates increase with age and with chronic disease comorbidity, both of which are associated with lower 25(OH)D concentration. To reduce the risk of infection, it is recommended that people at risk of influenza and/or COVID-19 consider taking 10,000 IU/d of vitamin D3 for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d. The goal should be to raise 25(OH)D concentrations above 40–60 ng/mL (100–150 nmol/L). For treatment of people who become infected with COVID-19, higher vitamin D3 doses might be useful. Randomized controlled trials and large population studies should be conducted to evaluate these recommendations.

Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths.

The terms 'antioxidant', 'oxidative stress' and 'oxidative damage' are widely used but rarely defined. This brief review attempts to define them and to examine the ways in which oxidative stress and oxidative damage can affect cell behaviour both in vivo and in cell culture, using cancer as an example.

Biochemistry of oxidative stress

https://www.med.upenn.edu/baurlab/pdfs/Resveratrol_delays_age-related_deterioration.pdf

Resveratrol delays age-related deterioration and mimics transcriptional aspects of dietary restriction without extending life span.

Fungal diseases represent an important paradigm in immunology, as they can result from either a lack of recognition by the immune system or overactivation of the inflammatory response. Research in this field is entering an exciting period of transition from studying the molecular and cellular bases of fungal virulence to determining the cellular and molecular mechanisms that maintain immune homeostasis with fungi. The fine line between these two research areas is central to our understanding of tissue homeostasis and its possible breakdown in fungal infections and diseases. Recent insights into immune responses to fungi suggest that functionally distinct mechanisms have evolved to achieve optimal host-fungus interactions in mammals.

Immunity to Fungal Infections

Inflammation, a biological response of body tissues to harmful stimuli, is also known to be involved in a host of diseases, such as obesity, atherosclerosis, rheumatoid arthritis, and even cancer. Isoflavones are a class of flavonoids that exhibit antioxidant, anticancer, antimicrobial, and anti-inflammatory properties. Increasing evidence has highlighted the potential for isoflavones to prevent the chronic diseases in which inflammation plays a key role, though the underlying mechanisms remain unclear. Recently, some studies have raised concerns about isoflavones induced negative effects like carcinogenesis, thymic involution, and immunosuppression. Therefore, this review aims to summarize the anti-inflammatory effects of isoflavones, unravel the underlying mechanisms, and present the potential health risks.

https://www.mdpi.com/2072-6643/8/6/361/pdf

Isoflavones: Anti-Inflammatory Benefit and Possible Caveats

The objective of the present study was to evaluate the effects of fibre source on intestinal mucosal barrier function in weaning piglets. A total of 125 piglets were randomly allotted on the basis of their body weight and litters to one of five experimental diets, i.e. a control diet without fibre source (CT), and diets in which expanded maize was replaced by 10 % maize fibre (MF), 10 % soyabean fibre (SF), 10 % wheat bran fibre (WBF) or 10 % pea fibre (PF). The diets and water were fed ad libitum for 30 d. Piglets on the WBF and PF diets had lower diarrhoea incidence compared with the MF- and SF-fed animals. A higher ratio of villous height:crypt depth in the ileum of WBF-fed piglets and higher colonic goblet cells in WBF- and PF-fed piglets were observed compared with CT-, MF- and SF-fed piglets. In the intestinal digesta, feeding WBF and PF resulted in increased Lactobacillus counts in the ileum and Bifidobacterium counts in the colon. Lower Escherichia coli counts occurred in the ileum and colon of WBF-fed piglets than in SF-fed piglets. Tight junction protein (zonula occludens 1; ZO-1) and Toll-like receptor 2 (TLR2) gene mRNA levels were up-regulated in the ileum and colon of pigs fed WBF; however, feeding MF and SF raised IL-1α and TNF-α mRNA levels. Furthermore, higher diamine oxidase activities, transforming growth factor-α, trefoil factor family and MHC-II concentration occurred when feeding WBF and PF. In conclusion, the various fibre sources had different effects on the ileal and colonic barrier function. Clearly, WBF and PF improved the intestinal barrier function, probably mediated by changes in microbiota composition and concomitant changes in TLR2 gene expression.

/pdf/dietary-fibre-affects-intestinal-mucosal-barrier-function-1fddevlq7b.pdf

Dietary fibre affects intestinal mucosal barrier function and regulates intestinal bacteria in weaning piglets.

Dietary resveratrol supplementation improves meat quality of finishing pigs through changing muscle fiber characteristics and antioxidative status

This study was undertaken to investigate the effects of oxidative stress on growth performance, nutrient digestibilities and activities of antioxidant enzymes of weanling pigs. In the experiment, 24 male LandrancexYorkshire weanling pigs were allotted to three groups of 8 animals each. Pigs were fed individually. According to a single factorial arrangement, pigs received diets with 5% of either fresh (group 1 and group 3) or oxidized fish oil (peroxide value was 786.50 meq O 2 /kg before inclusion in the diet, group 2). At the beginning of the experiment, pigs in group 3 received an intraperitoneal injection of diquat at 12 mg/kg of body weight. The trial lasted for 26 d. A metabolism test was carried out during the last 4 days of the second week. The results showed that feeding diets containing oxidized fish oil or injection with diquat depressed the growth performance and nutrient digestibilities of weanling pigs, decreased activities of antioxidant enzymes and increased concentration of malondialdehyde in plasma and liver. Intraperitoneal injection of diquat would induce more serious oxidative stress than oral intake of oxidized fish oil in the diet. In conclusion, administration of oxidized fish oil or diquat could induce oxidative stress in weanling pigs, and oxidative stress could depress growth performance and impact anti-oxidative ability of young pigs.

Bing Yu

Papers

Isoflavones: Anti-Inflammatory Benefit and Possible Caveats

Dietary fibre affects intestinal mucosal barrier function and regulates intestinal bacteria in weaning piglets.

Dietary resveratrol supplementation improves meat quality of finishing pigs through changing muscle fiber characteristics and antioxidative status

Effects of Oxidative Stress on Growth Performance, Nutrient Digestibilities and Activities of Antioxidative Enzymes of Weanling Pigs

MicroRNA-27a promotes myoblast proliferation by targeting myostatin.