Lei Yu

Bio: Lei Yu is an academic researcher from Harbin Medical University. The author has contributed to research in topics: Luciferase & Wild type. The author has an hindex of 2, co-authored 2 publications receiving 65 citations.

Protection from H1N1 influenza virus infections in mice by supplementation with selenium: a comparison with selenium-deficient mice.

Abstract: The present paper describes protective effects of supplemental selenium in mice infected with influenza virus. The effects of supplemental selenium on serum selenium levels, mortality, lung virus titers, and cytokine titers were investigated in mice inoculated intranasally with suspensions of influenza virus. Whereas the mortality of the virus-infected Se-deficient mice was 75%, along with a marked reduction in body weight, lower levels of TNF-α and IFN-γ and lower serum selenium concentrations, the mortality of mice maintained on feed containing 0.5 mg Se/kg in the form of sodium selenite was 25%.There were no significantly differences, however, in viral titer between the Se-adequate and the selenium-supplemented groups. The data indicate that selenium supplementation may provide a feasible approach to improving the immune response to viral infections, such as lethal influenza infection.

LINC00994 promoted invasion and proliferation of gastric cancer cell via regulating miR-765-3p.

Abstract: Emerging studies indicated that lncRNA is one crucial regulator in development and tumorigenesis. We firstly showed that LINC00994 was overexpressed in GC cells compare with GES-1. Compared to adjacent samples, the LINC00994 expression was increased in GC tissues by qRT-PCR assay. Furthermore, Elevated expression of LINC00994 induced GC cell invasion, proliferation and cycle. Luciferase reporter analysis indicated that ectopic miR-765-3p expression suppressed wild type LINC00994 luciferase activity, but not mutant LINC00994 in GC cells. Elevated expression of LINC00994 inhibited the miR-765-3p expression in GC cells. Compared to adjacent samples, the miR-765-3p expression was decreased in GC tissues by qRT-PCR assay. LINC00994 induced GC cell invasion and growth via modulating miR-765-3p. Thus, our data suggested an oncogenic role of LINC00994 in development of GC.

The Role of Selenium in Inflammation and Immunity: From Molecular Mechanisms to Therapeutic Opportunities

Abstract: Dietary selenium (]Se), mainly through its incorporation into selenoproteins, plays an important role in inflammation and immunity. Adequate levels of Se are important for initiating immunity, but they are also involved in regulating excessive immune responses and chronic inflammation. Evidence has emerged regarding roles for individual selenoproteins in regulating inflammation and immunity, and this has provided important insight into mechanisms by which Se influences these processes. Se deficiency has long been recognized to negatively impact immune cells during activation, differentiation, and proliferation. This is related to increased oxidative stress, but additional functions such as protein folding and calcium flux may also be impaired in immune cells under Se deficient conditions. Supplementing diets with above-adequate levels of Se can also impinge on immune cell function, with some types of inflammation and immunity particularly affected and sexually dimorphic effects of Se levels in so...

Nano-selenium and its nanomedicine applications: a critical review.

Abstract: Traditional supplements of selenium generally have a low degree of absorption and increased toxicity. Therefore, it is imperative to develop innovative systems as transporters of selenium compounds, which would raise the bioavailability of this element and allow its controlled release in the organism. Nanoscale selenium has attracted a great interest as a food additive especially in individuals with selenium deficiency, but also as a therapeutic agent without significant side effects in medicine. This review is focused on the incorporation of nanotechnological applications, in particular exploring the possibilities of a more effective way of administration, especially in selenium-deficient organisms. In addition, this review summarizes the survey of knowledge on selenium nanoparticles, their biological effects in the organism, advantages, absorption mechanisms, and nanotechnological applications for peroral administration.

Selenium, Selenoproteins and Viral Infection

Abstract: Reactive oxygen species (ROS) are frequently produced during viral infections. Generation of these ROS can be both beneficial and detrimental for many cellular functions. When overwhelming the antioxidant defense system, the excess of ROS induces oxidative stress. Viral infections lead to diseases characterized by a broad spectrum of clinical symptoms, with oxidative stress being one of their hallmarks. In many cases, ROS can, in turn, enhance viral replication leading to an amplification loop. Another important parameter for viral replication and pathogenicity is the nutritional status of the host. Viral infection simultaneously increases the demand for micronutrients and causes their loss, which leads to a deficiency that can be compensated by micronutrient supplementation. Among the nutrients implicated in viral infection, selenium (Se) has an important role in antioxidant defense, redox signaling and redox homeostasis. Most of biological activities of selenium is performed through its incorporation as a rare amino acid selenocysteine in the essential family of selenoproteins. Selenium deficiency, which is the main regulator of selenoprotein expression, has been associated with the pathogenicity of several viruses. In addition, several selenoprotein members, including glutathione peroxidases (GPX), thioredoxin reductases (TXNRD) seemed important in different models of viral replication. Finally, the formal identification of viral selenoproteins in the genome of molluscum contagiosum and fowlpox viruses demonstrated the importance of selenoproteins in viral cycle.

Selenium: an element for life

Abstract: This review aims to illustrate the importance of selenium (Se) for maintenance of overall health, especially for the thyroid, immunity, and homeostasis. Furthermore, it outlines the role of Se in reproduction and in virology and discusses the effects of Se supplementation in critical illness. The multifaceted aspects of this essential nutrient have attracted worldwide clinical and research interest in the last few decades. Se exerts its activity in the form of the aminoacid selenocysteine incorporated in selenoproteins. The impact of Se administration should be considered in relation to its apparent U shaped effects, i.e., exhibiting major advantages in Se-deficient individuals but specific health risks in those with Se excess. Addition of selenium to the administration of levothyroxine may be useful in patients with low Se intake and with mild-form or early-stage Hashimoto’s thyroiditis (HT). Serum Se concentration (possibly also at tissue level) decreases in inflammatory conditions and may vary with the severity and duration of the inflammatory process. In such cases, the effect of Se supplementation seems to be useful and rational. Meanwhile, Se’s ability to improve the activity of T cells and the cytotoxicity of natural killer cells could render it effective in viral disease. However, the evidence, and this should be stressed, is at present conflicting as to whether Se supplementation is of benefit in patients with HT, though there are indications that it is advantageous in cases of mild/moderate Graves’ Orbitopathy. The role of Se in type 2 diabetes mellitus (T2DM) is ambiguous, driven by both Se intake and serum levels. The evidence that insulin and glycaemia influence the transport and activity of Se, via regulatory activity on selenoproteins, and that high serum Se may have a diabetogenic effect suggests a ‘Janus-effect’ of Se in T2DM. Though the evidence is not as yet clear-cut, the organic form (selenomethionine), due to its pharmacokinetics, is likely to be more advantageous in long-term prevention, and supplementation efforts, while the inorganic form (sodium selenite) has proven effective in an acute, e.g., sepsis, clinical setting. Recent data indicate that functional selenoprotein single-nucleotide polymorphisms (SNPs) may interfere with Se utilization and effectiveness.