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Context Dipeptidyl peptidase-4 (DPP4) is originally described as a surface protein in lymphocytes. Lymphocyte infiltration and subsequent destruction of thyroid tissue have been considered as the central pathological mechanism in Hashimoto thyroiditis (HT). Objective The present study aimed to investigate DPP4 expression in peripheral blood and thyroid tissue in HT patients, and explore the role of DPP4 in the pathophysiological process of HT. Methods This case-control study recruited 40 drug-naive HT patients and 81 control individuals. Peripheral blood and thyroid specimens were collected for assessing the expression and activity of DPP4. Moreover, single-cell RNA sequencing (scRNA-seq) analysis of 6 "para-tumor tissues" samples from scRNA-seq data set GSE184362 and in vitro cell experiments were also conducted. Results The HT patients had similar DPP4 serum concentration and activity as the controls. However, the expression and activity of DPP4 was significantly increased in the thyroid of the HT group than in the control group. The scRNA-seq analysis showed that DPP4 expression was significantly increased in the HT group, and mainly expressed in T cells. Further in vitro studies showed that inhibition of lymphocyte DPP4 activity with sitagliptin downregulated the production of inflammatory factors in co-cultured thyroid cells. Conclusion DPP4 expression was significantly increased in the thyroid of the HT group compared with the control group, and was mainly localized in the lymphocytes. Inhibition of lymphocyte DPP4 activity reduced the production of inflammatory factors in co-cultured thyroid cells. Therefore, inhibition of DPP4 may have a beneficial effect by alleviating inflammatory reactions in HT patients. [ABSTRACT FROM AUTHOR]

Iron deficiency is a global nutritional problem, and adding iron salts directly to food will have certain side effects on the human body. Therefore, there is growing interest in food-grade iron delivery systems. This review provides an overview of iron delivery systems, with emphasis on the controlled release of iron during gastrointestinal digestion, as well as the enhancement of iron absorption and bioavailability. Iron-bearing proteins are easily degraded by digestive enzymes and absorbed through receptor-mediated endocytosis. Instead, protein aggregates are slowly degraded in the stomach, which delays iron release and serves as a potential iron supplement. Amino acids, peptides and polysaccharides can bind iron through iron binding sites, but the formed compounds are prone to dissociation in the stomach. Moreover, peptides and polysaccharides can deliver iron by mediating the formation of ferric oxyhydroxide which is absorbed through endocytosis or bivalent transporter 1. In addition, liposomes are unstable during gastric digestion and iron is released in large quantities. Complexes formed by polysaccharides and proteins, and microcapsules formed by polysaccharides can delay the release of iron in the gastric environment and prolong iron release in the intestinal environment. This review is conducive to the development of iron functional ingredients and dietary supplements. [ABSTRACT FROM AUTHOR]

Switchgrass (Panicum virgatum L.) is a perennial warm-season C4 grass identified as a model species for bioenergy feedstock production. Lanthanum (La) as a rare earth element can stimulate the physiological processes of plant growth. The purpose of this study was to investigate the effect of lanthanum on seed germination of switchgrass. However, no significant differences in seed germination were found. The energy dispersive X-ray analysis showed that abundant lanthanum deposits resided on the pericarp and testa of the seed while few lanthanum deposits were present on the aleurone and endosperm. This phenomenon demonstrates that a semi-permeable layer, which could restrict or impede solute exchange, while allowing the permeability of internal and external water and gas, may be located between the testa and aleurone. Light microscopy and histochemical analysis revealed that the main chemical composition of the semi-permeable layer would be expected to be suberin because the layer was stained yellow with aniline blue. The quantum chemical calculations predict that the intervals between adjacent carbon chains in suberin molecule are so small that lanthanum ([La(H2O)8]3+) cannot pass through the suberin molecule. In conclusion, the seed germination of switchgrass is not affected by lanthanum because the semi-permeable layer restricts the penetration of lanthanum into the embryo.

BACKGROUND: The contribution and mechanism of κ‐/ι‐carrageenan (CG) with different hydration characteristics on the gelling properties of shrimp myofibrillar protein (MP) gelation was studied. RESULTS: The gel strength, water‐holding capacity and viscoelastic properties of MP gels were significantly enhanced by 1.0% κ‐/ι‐CG (P < 0.05), but the microstructure showed that excessive carrageenan caused fragmentation of the gel network and a corresponding decrease in gel properties. Compared to MP‐ιCG, MP‐κCG showed larger breaking force and shorter breaking distance, thus enhancing the hardness and brittleness of the gel, which might be ascribed to a reinforced network skeleton and a tighter binding of κCG‐myosin. However, MP‐ιCG stabilized more moisture in the gel network, thereby improving the tenderness of the gel, which might be related to the electrostatic repulsion observed between the sulfate groups of ιCG and the myosin observed by molecular docking. In addition, the β‐sheet content and intermolecular interactions might be positively correlated with gel properties. CONCLUSION: In this study, a composite gel system was constructed based on the interaction of MP and CG. The quality differences of two kinds of CG‐MP gels were clarified, which will provide guidance for the application of different kinds of carrageenan and the development of recombinant meat products with specific quality. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]