Oxidative stress induced by Se-deficient high-energy diet implicates neutrophil dysfunction via Nrf2 pathway suppression in swine

The mechanism of the interaction between Se deficiency and high energy remains limited. The aim of the current study was to identify whether Se-deficient, high-energy diet can induce oxidative stress, and downregulate the Nrf2 pathway and phagocytic dysfunction of neutrophils. We detected the phagocytic activity, ROS production, protein levels of Nrf2 and Nrf2 downstream target genes, and the mRNA levels of 25 selenoproteins, heat shock proteins, and cytokines in neutrophils. Cytokine ELISA kits were used to measure the serum cytokines. The concentration of ROS was elevated (P < 0.05) in obese swine fed on a low Se diet (less than 0.03 mg/kg Se) compared to control swine. The protein levels of Nrf2 and its downstream target genes were depressed during Se deficiency and high-energy intake. The mRNA levels of 16 selenoproteins were significantly decreased (P < 0.05) in the Se-deficient group and Se-deficient, high-energy group compared to the control group. However, the mRNA levels of 13 selenoproteins in peripheral blood neutrophils were upregulated in high energy group, except TrxR1, SelI and SepW. In summary, these data indicated that a Se-deficient, high-energy diet inhibits the Nrf2 pathway and its regulation of oxidative stress, and prompted a pleiotropic mechanism that suppresses phagocytosis.

Linkages between soil, crop, livestock, and human selenium status in Sub-Saharan Africa: a scoping review

Selenium (Se) is essential for human health, however, data on population Se status and agriculture-nutrition-health linkages are limited in sub-Saharan Africa (SSA). The scoping review aims to identify linkages between Se in soils/crops, dietary Se intakes, and livestock and human Se status in SSA. Online databases, organisational websites and grey literature were used to identify articles. Articles were screened at title, abstract and full text levels using eligibility criteria. The search yielded 166 articles from which 112 were excluded during abstract screening and 54 full text articles were assessed for eligibility. The scoping review included 34 primary studies published between 1984 and 2021. The studies covered Se concentrations in soils (n = 7), crops (n = 9), animal tissues (n = 2), livestock (n = 3), and human Se status (n = 15). The evidence showed that soil/crop Se concentrations affected Se concentration in dietary sources, dietary Se intake and biomarkers of Se status. Soil types are a primary driver of human Se status and crop Se concentration correlates positively with biomarkers of Se dietary status. Although data sets of Se concentrations exist across the food system in SSA, there is limited evidence on linkages across the agriculture-nutrition nexus. Extensive research on Se linkages across the food chain is warranted.

Translational Selenium Nanoparticles Promotes Clinical Non-small-cell Lung Cancer Chemotherapy via Activating Selenoprotein-driven Immune Manipulation

Reconstructing the tumor immune microenvironment is an effective strategy to enhance therapeutic efficacy limited by immunosuppression in non-small-cell lung cancer (NSCLC). In this study, it is found that selenium (Se) depletion and immune dysfunction are present in patients with advanced NSCLC compared with healthy volunteers. Surprisingly, Se deficiency resulted in decreased immunity and accelerated rapid tumor growth in the mice model, which further reveals that the correlation between micronutrient Se and lung cancer progression. This pioneering work achieves 500-L scale production of Se nanoparticles (SeNPs) at GMP level and utilizes it to reveal how and why the trace element Se can enhance clinical immune-mediated treatment efficacy against NSCLC. The results found that translational SeNPs can promote the proliferation of NK cells and enhance its cytotoxicity against cancer cells by activating mTOR signaling pathway driven by GPXs to regulate the secretion of cytokines to achieve an antitumor response. Moreover, a clinical study of an Investigator-initiated Trial shows that translational SeNPs supplementation in combination with bevacizumab/cisplatin/pemetrexed exhibits enhanced therapeutic efficacy with an objective response rate of 83.3% and a disease control rate of 100%, through potentiating selenoprotein-driven antitumor immunity. Taken together, this study, for the first time, highlights the translational SeNPs-enhanced therapeutic efficacy against clinical advanced NSCLC.