Endurance exercise training decreased serum levels of surfactant protein D and improved aerobic fitness of obese women with type-2 diabetes

Combined Effects of Exercise Training and Nutritional Supplementation in Cancer Patients in the Context of the COVID-19: A Perspective Study

The 2019 coronavirus (COVID-19) epidemic, has caused unprecedented global social and economic impacts and many deaths. Many risk factors have been identified in the progression of COVID-19 to severe and critical stages, and it is shown that the coronavirus appears more severely in people with cancer. Pro-inflammatory status and weakened immune system due to cancer-related treatments can be determinants in the immune system’s response to the coronavirus in these patients. Higher physical activity levels are associated with lower hospitalization rates and mortality in COVID-19. Also, regular exercise training can improve immune system responses, modulate inflammatory responses, and improve psychological parameters in cancer patients. The interactive effects of nutritional supplements on immune responses and anti-inflammatory status have been shown in some studies. The purpose of this perspective article was to investigate the interaction between dietary supplementation and regular physical exercise in controlling risk factors associated with coronavirus in cancer patients. In addition to appropriate dietary habits, some nutritional supplements, especially vitamin D, have been shown to improve the immune system’s response against COVID-19 and cancer. Using lifestyle strategies such as regular physical activity and intake of functional compounds as supplements can be effective in treatment outcomes, quality of life, and overall survival in cancer patients. We proposed that combining dietary supplements and exercise training in cancer patients can boost immune responses against COVID-19 and probably improve vaccine responses. Angiotensin (ANG)-(1-7) Mas receptor axis can probably activate following exercise training and vitamin D combination. And can prevent pulmonary injury, hematological alterations, and hyperinflammatory state in COVID-19.

Surfactant Protein D Recognizes Multiple Fungal Ligands: A Key Step to Initiate and Intensify the Anti-fungal Host Defense

With limited therapeutic options and associated severe adverse effects, fungal infections are a serious threat to human health. Innate immune response mediated by pattern recognition proteins is integral to host defense against fungi. A soluble pattern recognition protein, Surfactant protein D (SP-D), plays an important role in immune surveillance to detect and eliminate human pathogens. SP-D exerts its immunomodulatory activity via direct interaction with several receptors on the epithelial cells lining the mucosal tracts, as well as on innate and adaptive immune cells. Being a C-type lectin, SP-D shows calcium- and sugar-dependent interactions with several glycosylated ligands present on fungal cell walls. The interactome includes cell wall polysaccharides such as 1,3-β-D-glucan, 1,6-β-D-glucan, Galactosaminogalactan Galactomannan, Glucuronoxylomannan, Mannoprotein 1, and glycosylated proteins such as gp45, gp55, major surface glycoprotein complex (gpA). Recently, binding of a recombinant fragment of human SP-D to melanin on the dormant conidia of Aspergillus fumigatus was demonstrated that was not inhibited by sugars, suggesting a likely protein-protein interaction. Interactions of the ligands on the fungal spores with the oligomeric forms of full-length SP-D resulted in formation of spore-aggregates, increased uptake by phagocytes and rapid clearance besides a direct fungicidal effect against C. albicans. Exogenous administration of SP-D showed significant therapeutic potential in murine models of allergic and invasive mycoses. Altered susceptibility of SP-D gene-deficient mice to various fungal infections emphasized relevance of SP-D as an important sentinel of anti-fungal immunity. Levels of SP-D in the serum or lung lavage were significantly altered in the murine models and patients of fungal infections and allergies. Here, we review the cell wall ligands of clinically relevant fungal pathogens and allergens that are recognized by SP-D and their impact on the host defense. Elucidation of the molecular interactions between innate immune humoral such as SP-D and fungal pathogens would facilitate the development of novel therapeutic interventions.

Circulating Surfactant Protein-D Is Associated With Clinical Outcomes in Peripheral Artery Disease Patients Following Endovascular Therapy

BACKGROUND

Peripheral artery disease (PAD) is a risk factor for the development of cardiovascular disease and death. Surfactant protein-D (SP-D) is a 43-kDa protein secreted from type II pneumocytes in the lungs. Recent studies have demonstrated that circulating SP-D plays a key role in the development of atherosclerosis and is related to clinical outcomes in patients with ischemic heart disease. However, it remains unclear whether circulating SP-D is associated with clinical outcomes in patients with PAD.Methods and Results:We enrolled 364 patients with PAD who underwent endovascular therapy. We measured serum levels of SP-D and Krebs von den Lungen-6 (KL-6). During a median follow-up period of 974 days, there were 69 major adverse cardiovascular and leg events (MACLE), including 48 major adverse cardiovascular events (MACE). Kaplan-Meier analysis demonstrated that patients with high SP-D (≥110 ng/mL) had higher rates of MACE and MACLE than those with low SP-D. Multivariate Cox proportional hazard regression analysis demonstrated that SP-D, but not KL-6, was an independent predictor of MACE and MACLE. The addition of SP-D to known risk factors significantly improved the C index and net reclassification index. The circulating SP-D level was affected by sex, diabetes mellitus, and cilostazol prescription.

CONCLUSIONS

Circulating SP-D was associated with clinical outcomes in patients with PAD, suggesting that it may be a new therapeutic target in these patients.