MicroRNAs as Potential Regulators of Glutathione Peroxidases Expression and Their Role in Obesity and Related Pathologies

Selenoprotein-p and insulin resistance in children and adolescents with obesity

BACKGROUND

Insulin resistance and obesity present significant challenges in pediatric populations. Selenoprotein P1 (SEPP1) serves as a biomarker for assessing selenium levels in the body. While its association with metabolic syndrome is established in adults, its relevance in children remains underexplored.

AIM

To ascertain SEPP1 blood levels in children and adolescents diagnosed with obesity and to assess its correlation with insulin resistance and adiposity indices.

METHODS

170 children participated in this study, including 85 diagnosed with obesity and an equal number of healthy counterparts matched for age and sex. Each participant underwent a comprehensive medical evaluation, encompassing a detailed medical history, clinical examination, and anthropometric measurements like waist circumference and waist-to-height ratio. Furthermore, routine blood tests were conducted, including serum SEPP1, visceral adiposity index (VAI), and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) level.

RESULTS

Our findings revealed significantly lower serum SEPP1 levels in children with obesity compared to their healthy peers. Moreover, notable negative correlations were observed between serum SEPP1 levels and body mass index, VAI, and HOMA-IR.

CONCLUSION

The study suggests that SEPP1 could serve as a valuable predictor for insulin resistance among children and adolescents diagnosed with obesity. This highlights the potential utility of SEPP1 in pediatric metabolic health assessment and warrants further investigation.

CircRAB11A act as miR-24-5p sponge promotes proliferation and resists apoptosis of chicken granulosa cell via EGFR/ERK1/2 and RAB11A/ PI3K/AKT pathways

Circular RNAs (circRNAs) are a class of endogenous non-coding RNAs that have been implicated in mediating granulosa cell (GC) proliferation and apoptosis. CircRAB11A was found to have a significantly higher expression in normal follicles compared to atrophic follicles. In this study, we determined that the knockdown of circRAB11A resulted in the inhibition of proliferation and promotion of apoptosis in GCs of chicken. Moreover, circRAB11A was found to act as a sponge for miR-24-5p, both member RAS oncogene family (RAB11A) and epidermal growth factor receptor (EGFR) were revealed to be targets of miR-24-5p through a dual-luciferase reporter assay. RAB11A or EGFR promoted proliferation and suppressed apoptosis in GCs through the phosphatidylinositol-kinase (PI3K)/AKT or extracellular signal-regulated kinase (ERK)1/2 pathway. These findings suggest that circRAB11A may function as a competing endogenous RNA (ceRNA) by targeting the miR-24-5p/RAB11A and miR-24-5p/EGFR axes and activating the ERK1/2 and PI3K/AKT pathways, offering a potential avenue for exploring the mechanism of follicle development.

Exploring oxidative stress, immunological and metabolic biomarkers in dairy cows with postpartum pyometra

Pyometra is a prevalent and severe infectious disease that affects the reproductive systems of cattle worldwide. This study's main goal was to investigate the biomarkers for oxidative stress (OS), adiponectin, leptin and neopterin (NPT) in cows suffering from postpartum pyometra. The study also aimed to determine which bacteria were most commonly implicated in the development of the disease. A total of 74 cows with pyometra were examined and compared to a control group of healthy cows (n = 20). In comparison to the healthy control and post-treatment groups, the pyometra group showed higher mean values of leptin, adiponectin and malondialdehyde (MDA). In contrast, the glutathione (GSH) and superoxide dismutase (SOD) mean values were lower in the pyometra group as compared to the post-treatment and control groups. NPT levels in the post-treatment groups were lower than those in cows with pyometra but comparable to the healthy control group (p > .05). When compared to the other biomarkers, NPT, leptin and adiponectin showed higher sensitivity and specificity in identifying pyometra cases (AUC ≥0.99). The predominant bacterial isolates from the ptomtra-affected cows consisted of Escherichia coli (N = 29; 39.2%), Arcanobacterium pyogenes (N = 27; 36.5%) and Fusobacterium necrophorum (N = 13; 17.6%). Mixed infection was determined in nine samples (12.2%). Conclusively, OS, adiponectin, leptin and NPT play crucial roles in comprehending the development of postpartum pyometra in cows and have the potential to serve as biomarkers for the disease.

BAP31-Mediated miR-206/133b Cluster Promotes Transendothelial Migration and Metastasis of Colorectal Cancer

Dysregulated B cell receptor-associated protein 31 (BAP31) plays a crucial role in tumor progression. This study aimed to investigate the functions and molecular mechanism of BAP31 on the miR-206/133b cluster in colorectal cancer (CRC). qPCR was conducted to detect miRNA and mRNA levels in tissues and cells. Western blot assays were used to assess the levels of biomarkers and targets, as well as the levels of BAP31 and HOXD10. Wound healing, coculture and transwell assays were conducted to assess the transendothelial migration abilities of CRC cells. A luciferase assay was employed to assess miRNA binding effects on targets, as well as the initiating transcription effect of genomic fragments. Tumor growth and lung metastatic models were established through an in vivo animal study. BAP31 overexpression in CRC cells led to a reduction in the expression of the miR-206/133b cluster. The expression of the miR-206/133b cluster was correlated with the transendothelial migration capability of CRC cells. The miR-206/133b cluster was found to directly regulate cell division cycle 42 (CDC42) and actin-related protein 2/3 complex subunit 5 (ARPC5) in the tight junction pathway (hsa04530). Moreover, a potential transcription regulator of the miR-206/133b cluster was also found to be Homeobox D10 (HOXD10). We further elucidated the molecular mechanisms and functional mechanisms of BAP31's regulatory role in the expression levels of the miR-206/133b cluster by inhibiting HOXD10 translocation from the cytoplasm to the nucleus. In conclusion, this study provides valuable insights into how BAP31 regulates the transcription of the miR-206/133b cluster and how BAP31-related lung metastases arise in CRC.

Role of MicroRNAs in Dietary Interventions for Obesity and Obesity-Related Diseases

Obesity and related metabolic syndromes pose a serious threat to human health and quality of life. A proper diet is a safe and effective strategy to prevent and control obesity, thus maintaining overall health. However, no consensus exists on the connotations of proper diet, and it is attributed to various factors, including "nutritional dark matter" and the "matrix effect" of food. Accumulating evidence confirms that obesity is associated with the in vivo levels of miRNAs, which serve as potential markers and regulatory targets for obesity onset and progression; food-derived miRNAs can regulate host obesity by targeting the related genes or gut microbiota across the animal kingdom. Host miRNAs mediate food nutrient-gut microbiota-obesity interactions. Thus, miRNAs are important correlates of diet and obesity onset. This review outlines the recent findings on miRNA-mediated food interventions for obesity, thereby elucidating their potential applications. Overall, we provide new perspectives and views on the evaluation of dietary nutrition, which may bear important implications for dietary control and obesity prevention.

In Vitro Antioxidant and Inhibitory Study of Picrorhiza kurroa (Kutki), Syzygium aromaticum (Loung), Lawsonia inermis (Henna), Rheum emodi (Revand Chini), Curcuma longa (Haldi) Against Lipid Per-Oxidation in Mice Brain and Liver

The aerobic organisms not only need oxygen for survival, but oxygen is also fundamentally malignant to the aerobic organism on the grounds of free radical generation and their affiliation with free oxidative stress. This study was done to evaluate the antioxidant and protective properties of P kurroa, S aromaticum, L inermis, R emodi, and C longa against lipid peroxidation induced by different pro-oxidants. The aqueous extracts of these medicinal plants showed inhibition against thiobarbituric acid reactive species (TBARS) induced by different pro-oxidants (10 mM FeSO4 and 5 mM sodium nitroprusside) in the brain and liver of mice. Moreover, the free radical scavenging activities of the extracts were evaluated by the scavenging of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. L inermis, S aromaticum, and R emodi showed higher inhibitory effects, which could be attributed to their significantly reduced ability and free radical scavenging activities. Therefore, the oxidative stress in the brain and liver could be potentially managed or prevented by the dietary intake of L inermis, S aromaticum, and R emodi plants, which justifies the use of these plants in various degenerative diseases. C longa and P kurroa showed relatively weak antioxidant activities.

Myrtle Berries Seeds Prevent Dyslipidemia, Inflammation, and Excessive Cardiac Reactive Oxygen Species Production in Response to High-Fat Diet-Induced Obesity

Anthocyanins are the major polyphenols in myrtle berries seeds aqueous extract (MBSAE). This study investigates the protective potentials of MBSAE against obesity lipotoxicity and inflammation induced by a high-fat diet (HFD). It also describes the underlying mechanisms involved in its protective effects, with special attention to myocardial reactive oxygen species (ROS) production. Male Wistar rats were fed HFD for 6 weeks to induce obesity. MBSAE (100 mg/kg, b.w., p.o.) was orally administered to HFD-fed rats. Anti-obesity effects were triggered by the inhibitory action of the MBSAE against the weights of the body, its relative heart and the total abdominal fat. Treatment with MBSAE also restored the lipid profile to baseline compared with the HFD rats and lowered also the white blood cells count, including neutrophils, lymphocytes, and basophils number as well as cytokines (tumor necrosis factor-α, interleukin [IL]-6, and IL-1β) levels in the rats serum, thus improving the tissue inflammatory status associated with obesity. Exposure of rats to HFD during 6 weeks induces a myocardial oxidative stress as assessed by deleterious effects on lipoperoxidation state, antioxidant enzyme (SOD, CAT, and GPx) activities as well as sulfhydryl groups and GSH rates. Of importance, our study shows also that HFD provokes a heart ROS (H2O2, OH•, and O2•-) overload. Of interest, all these oxidative heart disturbances were clearly ended by MBSAE treatment. Therefore, consumption of MBSAE as a natural extract may be a potential therapeutic strategy to treat obesity-associated diseases.

Natural Compounds and Glutathione: Beyond Mere Antioxidants

The tripeptide glutathione plays important roles in many cell processes, including differentiation, proliferation, and apoptosis; in fact, disorders in glutathione homeostasis are involved both in the etiology and in the progression of several human diseases, including cancer. Natural compounds have been found to modulate glutathione levels and function beyond their role as mere antioxidants. For example, certain compounds can upregulate the expression of glutathione-related enzymes, increase the availability of cysteine, the limiting amino acid for glutathione synthesis, or directly interact with glutathione and modulate its function. These compounds may have therapeutic potential in a variety of disease states where glutathione dysregulation is a contributing factor. On the other hand, flavonoids' potential to deplete glutathione levels could be significant for cancer treatment. Overall, while natural compounds may have potential therapeutic and/or preventive properties and may be able to increase glutathione levels, more research is needed to fully understand their mechanisms of action and their potential benefits for the prevention and treatment of several diseases. In this review, particular emphasis will be placed on phytochemical compounds belonging to the class of polyphenols, terpenoids, and glucosinolates that have an impact on glutathione-related processes, both in physiological and pathological conditions. These classes of secondary metabolites represent the most food-derived bioactive compounds that have been intensively explored and studied in the last few decades.

Cellular Compartmentalization, Glutathione Transport and Its Relevance in Some Pathologies

Reduced glutathione (GSH) is the most abundant non-protein endogenous thiol. It is a ubiquitous molecule produced in most organs, but its synthesis is predominantly in the liver, the tissue in charge of storing and distributing it. GSH is involved in the detoxification of free radicals, peroxides and xenobiotics (drugs, pollutants, carcinogens, etc.), protects biological membranes from lipid peroxidation, and is an important regulator of cell homeostasis, since it participates in signaling redox, regulation of the synthesis and degradation of proteins (S-glutathionylation), signal transduction, various apoptotic processes, gene expression, cell proliferation, DNA and RNA synthesis, etc. GSH transport is a vital step in cellular homeostasis supported by the liver through providing extrahepatic organs (such as the kidney, lung, intestine, and brain, among others) with the said antioxidant. The wide range of functions within the cell in which glutathione is involved shows that glutathione’s role in cellular homeostasis goes beyond being a simple antioxidant agent; therefore, the importance of this tripeptide needs to be reassessed from a broader metabolic perspective.

Cellular and Molecular Mechanisms Associating Obesity to Bone Loss

Obesity is an alarming disease that favors the upset of other illnesses and enhances mortality. It is spreading fast worldwide may affect more than 1 billion people by 2030. The imbalance between excessive food ingestion and less energy expenditure leads to pathological adipose tissue expansion, characterized by increased production of proinflammatory mediators with harmful interferences in the whole organism. Bone tissue is one of those target tissues in obesity. Bone is a mineralized connective tissue that is constantly renewed to maintain its mechanical properties. Osteoblasts are responsible for extracellular matrix synthesis, while osteoclasts resorb damaged bone, and the osteocytes have a regulatory role in this process, releasing growth factors and other proteins. A balanced activity among these actors is necessary for healthy bone remodeling. In obesity, several mechanisms may trigger incorrect remodeling, increasing bone resorption to the detriment of bone formation rates. Thus, excessive weight gain may represent higher bone fragility and fracture risk. This review highlights recent insights on the central mechanisms related to obesity-associated abnormal bone. Publications from the last ten years have shown that the main molecular mechanisms associated with obesity and bone loss involve: proinflammatory adipokines and osteokines production, oxidative stress, non-coding RNA interference, insulin resistance, and changes in gut microbiota. The data collection unveils new targets for prevention and putative therapeutic tools against unbalancing bone metabolism during obesity.

An overview on role of nutrition on COVID-19 immunity: Accumulative review from available studies

The novel coronavirus infection (COVID-19) conveys a serious global threat to health and economy. A common predisposing factor for development to serious progressive disease is presence of a low-grade inflammation, e.g., as seen in diabetes, metabolic syndrome, and heart failure. Micronutrient deficiencies may also contribute to the development of this state. Therefore, the aim of the present study is to explore the role of the nutrition to relieve progression of COVID-19. According PRISMA protocol, we conducted an online databases search including Scopus, PubMed, Google Scholar and web of science for published literatures in the era of COVID-19 Outbreak regarding to the status of nutrition and COVID-19 until December 2021. There were available studies (80 studies) providing direct evidence regarding the associations between the status of nutrition and COVID-19 infection. Adequate nutritional supply is essential for resistance against other viral infections and also for improvement of immune function and reduction of inflammation. Hence, it is suggested that nutritional intervention which secures an adequate status might protect against the novel coronavirus SARS-CoV-2 (Severe Acute Respiratory Syndrome - coronavirus-2) and mitigate its course. We also recommend initiation of adequate nutritional supplementation in high-risk areas and/or soon after the time of suspected infection with SARS-CoV-2. Subjects in high-risk groups should have high priority for applying this nutritive adjuvant therapy that should be started prior to administration of specific and supportive medical measures.

Biological Activity of Selenium and Its Impact on Human Health

Selenium (Se) is a naturally occurring metalloid element essential to human and animal health in trace amounts but it is harmful in excess. Se plays a substantial role in the functioning of the human organism. It is incorporated into selenoproteins, thus supporting antioxidant defense systems. Selenoproteins participate in the metabolism of thyroid hormones, control reproductive functions and exert neuroprotective effects. Among the elements, Se has one of the narrowest ranges between dietary deficiency and toxic levels. Its level of toxicity may depend on chemical form, as inorganic and organic species have distinct biological properties. Over the last decades, optimization of population Se intake for the prevention of diseases related to Se deficiency or excess has been recognized as a pressing issue in modern healthcare worldwide. Low selenium status has been associated with an increased risk of mortality, poor immune function, cognitive decline, and thyroid dysfunction. On the other hand, Se concentrations slightly above its nutritional levels have been shown to have adverse effects on a broad spectrum of neurological functions and to increase the risk of type-2 diabetes. Comprehension of the selenium biochemical pathways under normal physiological conditions is therefore an important issue to elucidate its effect on human diseases. This review gives an overview of the role of Se in human health highlighting the effects of its deficiency and excess in the body. The biological activity of Se, mainly performed through selenoproteins, and its epigenetic effect is discussed. Moreover, a brief overview of selenium phytoremediation and rhizofiltration approaches is reported.

Adipose Tissue Dysfunction: Impact on Metabolic Changes?

Adipose tissue is a metabolically dynamic organ that is the primary site of storage for excess energy, but it serves as an endocrine organ capable of synthesizing a number of biologically active compounds that regulate metabolic homeostasis. However, when the capacity of expansion of this tissue exceeds, dysfunction occurs, favoring ectopic accumulation of fat in the visceral, which has been implicated in several disease states, most notably obesity. This review highlights the mechanisms involved in the structure of adipose tissue, tissue expandability, adipocyte dysfunction, as well as the impact of these events on the manifestation of important metabolic disorders associated with adipose tissue dysfunction. A literature search using Pubmed, Web of Science, Scopus, and Cochrane databases were used to identify relevant studies, using clinical trials, experimental studies in animals and humans, case-control studies, case series, letters to the editor, and review articles published in English, without restrictions on year of publication. The excessive ectopic lipid accumulation leads to local inflammation and insulin resistance. Indeed, overnutrition triggers uncontrolled inflammatory responses white adipose tissue, leading to chronic low-grade inflammation, therefore fostering the progression of important metabolic disorders. Thus, it is essential to advance the understanding of the molecular mechanisms involved in adipose tissue dysfunction in order to mitigate the negative metabolic consequences of obesity.

Glutathione Depletion and MicroRNA Dysregulation in Multiple System Atrophy: A Review

Multiple system atrophy (MSA) is a rare neurodegenerative disease characterized by parkinsonism, cerebellar impairment, and autonomic failure. Although the causes of MSA onset and progression remain uncertain, its pathogenesis may involve oxidative stress via the generation of excess reactive oxygen species and/or destruction of the antioxidant system. One of the most powerful antioxidants is glutathione, which plays essential roles as an antioxidant enzyme cofactor, cysteine-storage molecule, major redox buffer, and neuromodulator, in addition to being a key antioxidant in the central nervous system. Glutathione levels are known to be reduced in neurodegenerative diseases. In addition, genes regulating redox states have been shown to be post-transcriptionally modified by microRNA (miRNA), one of the most important types of non-coding RNA. miRNAs have been reported to be dysregulated in several diseases, including MSA. In this review, we focused on the relation between glutathione deficiency, miRNA dysregulation and oxidative stress and their close relation with MSA pathology.

The role of microRNAs in erectile dysfunction: From pathogenesis to therapeutic potential

Erectile dysfunction (ED) is a common male sexual dysfunction disease, and it was predicted that the number of ED patients worldwide will reach 322 million by 2025. However, the pathogenesis of ED is complex and the current treatment options are still limited, so it is urgent to explore new treatment strategies. Recent studies have shown that microRNAs (miRNAs) play an important role in ED, and these single-stranded non-coding small RNA molecules are involved in key pathophysiological processes in the occurrence and development of ED. Therefore, miRNAs have remarkable potential as therapeutic targets in ED. Here, this review introduces the physiological basis of erectile function and the pathophysiological changes in ED and summarizes the current knowledge on the expression, biological functions, and molecular mechanisms of miRNAs in ED, especially the potential of miRNA-targeted therapies to improve ED. This review will provide a comprehensive view of the role of miRNAs in the pathogenesis of ED and the potential value of miRNAs in the treatment of ED.

Ferroptosis in glioma treatment: Current situation, prospects and drug applications

Ferroptosis is a regulatory form of iron-dependent cell death caused by the accumulation of lipid-based reactive oxygen species (ROS) and differs from apoptosis, pyroptosis, and necrosis. Especially in neoplastic diseases, the susceptibility of tumor cells to ferroptosis affects prognosis and is associated with complex effects. Gliomas are the most common primary intracranial tumors, accounting for disease in 81% of patients with malignant brain tumors. An increasing number of studies have revealed the particular characteristics of iron metabolism in glioma cells. Therefore, agents that target a wide range of molecules involved in ferroptosis may regulate this process and enhance glioma treatment. Here, we review the underlying mechanisms of ferroptosis and summarize the potential therapeutic options for targeting ferroptosis in glioma.

Impact of Hydrotherapy on Antioxidant Enzyme Activity in an Elderly Population

Oxidative stress is defined as the imbalance between reactive species and antioxidant agents. One of the effects of oxidative stress is the normal process of cellular aging that stems from the accumulation of tissue damage. Epidemiological studies show that regular physical exercise prevents the injuries caused by aging. The objective was to evaluate whether the practice of hydrotherapy, in an elderly population, positively influenced the activity of the enzymes superoxide dismutase, glutathione peroxidase and reductase that act by reducing reactive species in the body. The study involved 37 participants aged ≥ 60 years, of both sexes, divided into experimental and control groups. The experimental group performed 15 hydrotherapy sessions. Enzyme activity was evaluated in two moments: T0-before the first session, and T1-after the last session, with blood collections conducted in both. In T1, there was a significant increase vs. T0 of glutathione peroxidase activity (57.72 ± 19.99 vs. 48.14 ± 17.22 U/g Hb) and glutathione reductase activity (100.18 ± 30.85 vs. 78.44 ± 21.26 U/L). Both sexes tended to show higher values at T1. We concluded that hydrotherapy proved to be a positive stimulus for the enzymatic antioxidant activity of the elderly, suggesting that a regular and moderate practice of physical exercise induces better and higher quality of life.

Basis for using thioredoxin as an electron donor by Schizosaccharomyces pombe Gpx1 and Tpx1

Glutathione (GSH) peroxidases (GPxs or GSHPx) and thioredoxin (Trx) peroxidases (TPxs) are two classes of peroxidases that catalyze the reduction of peroxides. GPxs and TPxs generally use GSH or Trx, respectively, to recycle the oxidized cysteine (Cys) residue in the protein. However, it is unclear why unlike human GPxs, the Schizosaccharomyces pombe Gpx1 (spGpx1) prefers Trx over GSH for recycling of the active-site peroxidatic Cys residue. Here, we compared spGpx1 and S. pombe Tpx1 (spTpx1) protein sequences with those of their respective homologs in Saccharomyces cerevisiae and humans. Our analysis revealed that like spTpx1, spGpx1 contains a pair of conserved Cys residues (Cys36 and Cys82). These two conserved Cys residues are named peroxidatic and resolving Cys residues, respectively, and are found only in GPxs and TPxs that prefer Trx as an electron donor. Our analysis suggested that Cys36 and Cys82 in spGpx1 are most likely to form a disulfide bond upon oxidation of Cys36. Molecular modelling predicted that a conformational change might be required for the formation of this disulfide bond. Evolutionary analysis suggested that fungal GPxs and TPxs are related by divergent evolution from a common ancestor. Our analyses support a prediction that while spGpx1 and spTpx1 are phylogenetically and functionally different, they evolved from a common ancestor and use a similar mechanism for recycling of the active-site peroxidatic Cys residue.

spGpx1 contains two conserved Cys residues (Cys36 and Cys82), which may form a disulfide bond upon oxidation and the reduction of this disulfide bond is most likely to be mediated by Trx in vivo.

Fungal GPxs and TPxs evolved from a common ancestor.

Emerging Roles of Non-Coding RNAs in the Feed Efficiency of Livestock Species

A global population of already more than seven billion people has led to an increased demand for food and water, and especially the demand for meat. Moreover, the cost of feed used in animal production has also increased dramatically, which requires animal breeders to find alternatives to reduce feed consumption. Understanding the biology underlying feed efficiency (FE) allows for a better selection of feed-efficient animals. Non-coding RNAs (ncRNAs), especially micro RNAs (miRNAs) and long non-coding RNAs (lncRNAs), play important roles in the regulation of bio-logical processes and disease development. The functions of ncRNAs in the biology of FE have emerged as they participate in the regulation of many genes and pathways related to the major FE indicators, such as residual feed intake and feed conversion ratio. This review provides the state of the art studies related to the ncRNAs associated with FE in livestock species. The contribution of ncRNAs to FE in the liver, muscle, and adipose tissues were summarized. The research gap of the function of ncRNAs in key processes for improved FE, such as the nutrition, heat stress, and gut–brain axis, was examined. Finally, the potential uses of ncRNAs for the improvement of FE were discussed.

MicroRNAs mediated regulation of glutathione peroxidase 7 expression and its changes during adipogenesis

Glutathione peroxidase 7 (GPx7) acts as an intracellular stress sensor/transmitter and plays an important role in adipocyte differentiation and the prevention of obesity related pathologies. For this reason, finding the regulatory mechanisms that control GPx7 expression is of great importance. As microRNAs (miRNAs) could participate in the regulation of GPx7 expression, we studied the inhibition of GPx7 expression by four selected miRNAs with relation to obesity and adipogenesis. The effect of the transfection of selected miRNAs mimics on GPx7 expression was tested in three cell models (HEK293, SW480, AT-MSC). The interaction of selected miRNAs with the 3'UTR of GPx7 was followed up on using a luciferase gene reporter assay. In addition, the levels of GPx7 and selected miRNAs in adipose tissue mesenchymal stem cells (AT-MSC) and mature adipocytes from four human donors were compared, with the changes in these levels during adipogenesis analyzed. Our results show for the first time that miR-137 and miR-29b bind to the 3'UTR region of GPx7 and inhibit the expression of this enzyme at the mRNA and protein level in all the human cells tested. However, no negative correlation between miR-137 nor miR-29b level and GPx7 was observed during adipogenesis. Despite the confirmed inhibition of GPx7 expression by miR-137 and miR-29b, the action of these two molecules in adipogenesis and mature adipocytes must be accompanied by other regulators.

Dietary Selenium Regulates microRNAs in Metabolic Disease: Recent Progress

Selenium (Se) is an essential element for the maintenance of a healthy physiological state. However, due to environmental and dietary factors and the narrow safety range of Se, diseases caused by Se deficiency or excess have gained considerable traction in recent years. In particular, links have been identified between low Se status, cognitive decline, immune disorders, and increased mortality, whereas excess Se increases metabolic risk. Considerable evidence has suggested microRNAs (miRNAs) regulate interactions between the environment (including the diet) and genes, and play important roles in several diseases, including cancer. MiRNAs target messenger RNAs to induce changes in proteins including selenoprotein expression, ultimately generating disease. While a plethora of data exists on the epigenetic regulation of other dietary factors, nutrient Se epigenetics and especially miRNA regulated mechanisms remain unclear. Thus, this review mainly focuses on Se metabolism, pathogenic mechanisms, and miRNAs as key regulatory factors in Se-related diseases. Finally, we attempt to clarify the regulatory mechanisms underpinning Se, miRNAs, selenoproteins, and Se-related diseases.

Comprehensive Analysis Reveals Novel Interactions between Circulating MicroRNAs and Gut Microbiota Composition in Human Obesity

Background: The determinants that mediate the interactions between microRNAs and the gut microbiome impacting on obesity are scarcely understood. Thus, the aim of this study was to investigate possible interactions between circulating microRNAs and gut microbiota composition in obesity. Method: The sample comprised 78 subjects with obesity (cases, body mass index (BMI): 30–40 kg/m²) and 25 eutrophic individuals (controls, BMI ≤ 25 kg/m²). The expression of 96 microRNAs was investigated in plasma of all individuals using miRCURY LNA miRNA Custom PCR Panels. Bacterial DNA sequencing was performed following the Illumina 16S protocol. The FDR correction was used for multiple comparison analyses. Results: A total of 26 circulating microRNAs and 12 bacterial species were found differentially expressed between cases and controls. Interestingly, an interaction among three miRNAs (miR-130b-3p, miR-185-5p and miR-21-5p) with Bacteroides eggerthi and BMI levels was evidenced (r² = 0.148, p = 0.004). Moreover, these microRNAs regulate genes that participate in metabolism-related pathways, including fatty acid degradation, insulin signaling and glycerolipid metabolism. Conclusions: This study characterized an interaction between the abundance of 4 bacterial species and 14 circulating microRNAs in relation to obesity. Moreover, the current study also suggests that miRNAs may serve as a communication mechanism between the gut microbiome and human hosts.

Differential expression and significance of miRNAs in plasma extracellular vesicles of patients with Parkinson's disease

OBJECTIVE

To study the feasibility of plasma extracellular vesicles (EVs) miRNAs as diagnostic biomarkers for Parkinson's disease (PD).

METHODS

Plasma EVs were isolated from 30 PD patients and 30 age- and sex-matched healthy controls. Plasma EVs miRNAs were analysed by qRT-PCR. SH-SY5Y cells were induced by different concentrations of 1-Methyl-4-phenil-pyridinium (MPP⁺) to obtain PD cellular model. The levels of miRNAs and α-synuclein (α-syn) in PD cellular model were analysed by qRT-PCR and Western blot. Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic usefulness of the miRNAs in plasma EVs for PD. The gene ontology (GO) and KEGG pathways of the target genes of miRNAs were analysed by softwares.

RESULTS

The level of hsa-miR-30c-2-3p in plasma EVs was significantly higher in PD patients than that in controls, and the levels of hsa-miR-15b-5p, hsa-miR-138-5p, hsa-miR-338-3p, hsa-miR-106b-3p and hsa-miR-431-5p in plasma EVs were lower in PD patients than that in controls. When compared with the control group, the area under the curve (AUC) values for hsa-miR-15b-5p, hsa-miR-30c-2-3p, hsa-miR-138-5p, hsa-miR-431-5p, hsa-miR-338-3p and hsa-miR-106b-3p were all greater than 0.6. The target genes of hsa-miR-15b-5p, hsa-miR-30c-2-3p, hsa-miR-138-5p and hsa-miR-338-3p were enriched in dopaminergic synapse and PD pathway.

CONCLUSIONS

The hsa-miR-15b-5p, hsa-miR-30c-2-3p, hsa-miR-138-5p, hsa-miR-106b-3p, hsa-miR-338-3p and hsa-miR-431-5p may be used as potential biomarkers for the diagnosis of PD, and the combined diagnostic accuracy of hsa-miR-15b-5p, hsa-miR-30c-2-3p, hsa-miR-138-5p and hsa-miR-106b-3p was better. The target genes of hsa-miR-15b-5p, hsa-miR-30c-2-3p, hsa-miR-138-5p and hsa-miR-338-3p may regulate the expression of dopamine by dopaminergic synapse and PD pathway.HighlightsIsolation and identification of plasma EVs.The miRNAs in plasma EVs may be used as potential biomarkers for the diagnosis of PD.When SH-SY5Y cells were induced by different concentrations of MPP⁺, the levels of miRNAs and α-syn changed gradually.The target genes of miRNAs were enriched in dopaminergic synapse and PD pathway.The target genes of miRNAs may regulate the expression of dopamine.

Cross-talk between oxidative stress signaling and microRNA regulatory systems in carcinogenesis: Focused on gastrointestinal cancers

Molecular mechanisms underlying development and progression of gastrointestinal (GI) cancers are mediated by both oxidative stress (OS) and microRNAs (miRNAs) involvement. Notably, OS signaling may regulate the expression of miRNAs, and miRNAs function as imperative players in OS-initiated tumors. Given the defined biological roles of both OS systems and miRNAs in GI carcinogenesis, a possible interplay between these two key cellular networks is considered. A growing body of evidence has indicated a reciprocal connection between OS signaling pathways and miRNA regulatory machines in GI cancer development and progression. Illumination of the molecular cross-talking between miRNAs and the OS would improve our pathophysiological insight into carcinogens. Also, understanding the molecular mechanisms in which these systems are reciprocally regulated may imply in future medical practice mainly GI cancer therapy. Nowadays, therapeutic strategies focusing on miRNA and OS in GI cancer treatment are increasingly delineated. Since the use of antioxidants is limited owing to the contrasting consequences of OS signaling in cancer, the discovery of OS-responsive miRNAs may provide a potential new strategy to overcome OS-mediated GI carcinogenesis. Given the possible interaction between OS and miRNAs in GI cancers, this review aimed to elucidate the existing evidence on the interaction between OS and miRNA regulatory machinery and its role in GI carcinogenesis. In this regard, we will illustrate the function of miRNAs which target OS systems during homeostasis and tumorigenesis. We also discuss the biological cross-talk between OS systems and miRNAs and corresponding cell signaling pathways.

MicroRNA-7 Targets the KLF4 Gene to Regulate the Proliferation and Differentiation of Chicken Primary Myoblasts

The proliferation and differentiation of chicken primary myoblasts (CPMs) play an important role in the development of skeletal muscle. In our previous research, RNA-seq analysis showed that microRNA-7 (miR-7) was relatively highly expressed in the proliferation phase of CPMs, but its expression level decreased significantly after CPM_S-induced differentiation. Meanwhile, the mechanism by which the miR-7 regulates the proliferation and differentiation of CPMs is still unknown. In this study, we found that the expression levels of miR-7 and the Krüppel-like factor 4 (KLF4) gene were negatively correlated during the embryonic phase, and in vitro induced differentiation. A dual-luciferase assay and a rescue experiment show that there is a target relationship between miR-7 and the KLF4 gene. Meanwhile, the results show that overexpression of miR-7 inhibited the proliferation and differentiation of CPMs, while inhibition of miR-7 had the opposite effects. Furthermore, overexpression of the KLF4 gene was found to significantly promote the proliferation and differentiation of CPMs. Conversely, inhibition of the KLF4 gene was able to significantly decrease the proliferation and differentiation of CPMs. Our results demonstrate, for the first time, that miR-7 inhibits the proliferation and differentiation of myoblasts by targeting the KLF4 gene in chicken primary myoblasts.

Selenium and RNA Virus Interactions: Potential Implications for SARS-CoV-2 Infection (COVID-19)

SARS-CoV-2 is an RNA virus responsible for the COVID-19 pandemic that already claimed more than 340,000 lives worldwide as of May 23, 2020, the majority of which are elderly. Selenium (Se), a natural trace element, has a key and complex role in the immune system. It is well-documented that Se deficiency is associated with higher susceptibility to RNA viral infections and more severe disease outcome. In this article, we firstly present evidence on how Se deficiency promotes mutations, replication and virulence of RNA viruses. Next, we review how Se might be beneficial via restoration of host antioxidant capacity, reduction of apoptosis and endothelial cell damages as well as platelet aggregation. It also appears that low Se status is a common finding in conditions considered at risk of severe COVID-19, especially in the elderly. Finally, we present a rationale for Se use at different stages of COVID-19. Se has been overlooked but may have a significant place in COVID-19 spectrum management, particularly in vulnerable elderly, and might represent a game changer in the global response to COVID-19.

The effect of baicalin on microRNA expression profiles in porcine aortic vascular endothelial cells infected by Haemophilus parasuis

Glässer's disease, caused by Haemophilus parasuis (H. parasuis), is associated with vascular damage and vascular inflammation in pigs. Therefore, early assessment and treatment are essential to control the inflammatory disorder. MicroRNAs have been shown to be involved in the vascular pathology. Baicalin has important pharmacological functions, including anti-inflammatory, antimicrobial and antioxidant effects. In this study, we investigated the changes of microRNAs in porcine aortic vascular endothelial cells (PAVECs) induced by H. parasuis and the effect of baicalin in this model by utilizing high-throughput sequencing. The results showed that 155 novel microRNAs and 76 differentially expressed microRNAs were identified in all samples. Subsequently, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the target genes of the differentially expressed microRNAs demonstrated that regulation of actin cytoskeleton, focal adhesion, ECM-receptor interaction, bacterial invasion of epithelial cells, and adherens junction were the most interesting pathways after PAVECs were infected with H. parasuis. In addition, when the PAVECs were pretreated with baicalin, mismatch repair, peroxisome, oxidative phosphorylation, DNA replication, and ABC transporters were the most predominant signaling pathways. STRING analysis showed that most of the target genes of the differentially expressed microRNAs were associated with each other. The expression levels of the differentially expressed microRNAs were negatively co-regulated with their target genes' mRNA following pretreatment with baicalin in the H. parasuis-induced PAVECs using co-expression networks analysis. This is the first report that microRNAs might have key roles in inflammatory damage of vascular tissue during H. parasuis infection. Baicalin regulated the microRNAs changes in the PAVECs following H. parasuis infection, which may represent useful novel targets to prevent or treat H. parasuis infection.

Overexpression of GPX3, a potential biomarker for diagnosis and prognosis of breast cancer, inhibits progression of breast cancer cells in vitro

Background

Growing evidence has demonstrated that glutathione peroxidases (GPXs) family genes play critical roles in onset and progression of human cancer. However, a systematic study regarding expression, diagnostic and prognostic values, and function of GPXs family genes in breast cancer remains absent.

Materials and methods

Several databases were employed to perform in silico analyses for GPXs family genes. qRT-PCR, western blot and immunohistochemistry staining were introduced to validate GPX3 expression in breast cancer. The functions of GPX3 in breast cancer cells were successively determined.

Results

By combination of receiver operating characteristic (ROC) curve analysis, survival analysis and expression analysis, GPX3 was considered as a potential tumor suppressor and a promising diagnostic/prognostic biomarker in breast cancer. Next, low expression of GPX3 was confirmed in breast cancer cells and tissues when compared with corresponding normal controls. Overexpression of GPX3 markedly suppressed proliferation, colony formation, migration and invasion of breast cancer in vitro. Moreover, two potential mechanisms responsible for GPX3 downregulation in breast cancer, including hypermethylation of GPX3 promoter and release of hsa-miR-324-5p inhibition.

Conclusions

Collectively, we demonstrate that GPX3 is markedly downregulated in breast cancer, possesses significant diagnostic and prognostic values and attenuated in vitro growth and metastasis of breast cancer.

Targeting c-Src Reverses Accelerated GPX-1 mRNA Decay in Chronic Obstructive Pulmonary Disease Airway Epithelial Cells

Enhanced expression of the cellular antioxidant glutathione peroxidase (GPX)-1 prevents cigarette smoke-induced lung inflammation and tissue destruction. Subjects with chronic obstructive pulmonary disease (COPD), however, have decreased airway GPX-1 levels, rendering them more susceptible to disease onset and progression. The mechanisms that downregulate GPX-1 in the airway epithelium in COPD remain unknown. To ascertain these factors, analyses were conducted using human airway epithelial cells isolated from healthy subjects and human subjects with COPD and lung tissue from control and cigarette smoke-exposed A/J mice. Tyrosine phosphorylation modifies GPX-1 expression and cigarette smoke activates the tyrosine kinase c-Src. Therefore, studies were conducted to evaluate the role of c-Src on GPX-1 levels in COPD. These studies identified accelerated GPX-1 mRNA decay in COPD airway epithelial cells. Targeting the tyrosine kinase c-Src with siRNA inhibited GPX-1 mRNA degradation and restored GPX-1 protein levels in human airway epithelial cells. In contrast, silencing the tyrosine kinase c-Abl, or the transcriptional activator Nrf2, had no effect on GPX-1 mRNA stability. The chemical inhibitors for c-Src (saracatinib and dasanitib) restored GPX-1 mRNA levels and GPX-1 activity in COPD airway cells in vitro. Similarly, saracatinib prevented the loss of lung Gpx-1 expression in response to chronic smoke exposure in vivo. Thus, this study establishes that the decreased GPX-1 expression that occurs in COPD lungs is at least partially due to accelerated mRNA decay. Furthermore, these findings show that targeting c-Src represents a potential therapeutic approach to augment GPX-1 responses and counter smoke-induced lung disease.

Identification of Molecular Mechanisms Related to Pig Fatness at the Transcriptome and miRNAome Levels

Fat deposition and growth rate are closely related to pork quality and fattening efficiency. The next-generation sequencing (NGS) approach for transcriptome and miRNAome massive parallel sequencing of adipocyte tissue was applied to search for a molecular network related to fat deposition in pigs. Pigs were represented by three breeds (Large White, Pietrain, and Hampshire) that varied in fat content within each breed. The obtained results allowed for the detection of significant enrichment of Gene Ontology (GO) terms and pathways associated directly and indirectly with fat deposition via regulation of fatty acid metabolism, fat cell differentiation, inflammatory response, and extracellular matrix (ECM) organization and disassembly. Moreover, the results showed that adipocyte tissue content strongly affected the expression of leptin and other genes related to a response to excessive feed intake. The findings indicated that modification of genes and miRNAs involved in ECM rearrangements can be essential during fat tissue growth and development in pigs. The identified molecular network within genes and miRNAs that were deregulated depending on the subcutaneous fat level are proposed as candidate factors determining adipogenesis, fatness, and selected fattening characteristics in pigs.

Protective effects of bovine milk exosomes against oxidative stress in IEC-6 cells

PURPOSE

Bovine milk exosomes, which are enriched with microRNAs (miRNAs) and proteins, regulate immune response and growth. In the present study, we aimed to assess the protective effects of bovine milk exosomes against oxidative stress of intestinal crypt epithelial cells (IEC-6).

METHODS

Bovine milk exosomes were isolated and characterized. To assess the protective effects of exosomes, IEC-6 cells were pretreated with exosomes, followed by H₂O₂. Cell viability and levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GPX), reactive oxidative species (ROS), and lactate dehydrogenase (LDH) were measured. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (Ho1) genes, and miR-146a, miR-155, and the HO-1 protein were also determined.

RESULTS

The isolated bovine milk exosome were positive for CD63 and CD9 expression. The exosomes were approximately circular and had a diameter of about 67.23 nm. Pretreatment of IEC-6 cells with bovine milk exosomes enhanced cell viability; increased SOD and GPX activities; and reduced LDH, ROS, and MDA levels after H₂O₂ challenge. Further analysis showed that exosome pretreatment increased intracellular miR-146a and miR-155 levels. Exosome pretreatment inhibited the elevation of Nrf2 and Ho1 gene expression induced by H₂O₂, but promoted HO-1 protein expression.

CONCLUSION

The results indicated that bovine milk exosomes exerted protective effects against oxidative stress in IEC-6 cells.

Selenium and RNA Virus Interactions: Potential Implications for SARS-CoV-2 Infection (COVID-19)

SARS-CoV-2 is an RNA virus responsible for the COVID-19 pandemic that already claimed more than 340,000 lives worldwide as of May 23, 2020, the majority of which are elderly. Selenium (Se), a natural trace element, has a key and complex role in the immune system. It is well-documented that Se deficiency is associated with higher susceptibility to RNA viral infections and more severe disease outcome. In this article, we firstly present evidence on how Se deficiency promotes mutations, replication and virulence of RNA viruses. Next, we review how Se might be beneficial via restoration of host antioxidant capacity, reduction of apoptosis and endothelial cell damages as well as platelet aggregation. It also appears that low Se status is a common finding in conditions considered at risk of severe COVID-19, especially in the elderly. Finally, we present a rationale for Se use at different stages of COVID-19. Se has been overlooked but may have a significant place in COVID-19 spectrum management, particularly in vulnerable elderly, and might represent a game changer in the global response to COVID-19.

Selenium and RNA Virus Interactions: Potential Implications for SARS-CoV-2 Infection (COVID-19)

SARS-CoV-2 is an RNA virus responsible for the COVID-19 pandemic that already claimed more than 340,000 lives worldwide as of May 23, 2020, the majority of which are elderly. Selenium (Se), a natural trace element, has a key and complex role in the immune system. It is well-documented that Se deficiency is associated with higher susceptibility to RNA viral infections and more severe disease outcome. In this article, we firstly present evidence on how Se deficiency promotes mutations, replication and virulence of RNA viruses. Next, we review how Se might be beneficial via restoration of host antioxidant capacity, reduction of apoptosis and endothelial cell damages as well as platelet aggregation. It also appears that low Se status is a common finding in conditions considered at risk of severe COVID-19, especially in the elderly. Finally, we present a rationale for Se use at different stages of COVID-19. Se has been overlooked but may have a significant place in COVID-19 spectrum management, particularly in vulnerable elderly, and might represent a game changer in the global response to COVID-19.

Reactive Oxygen Species-Induced Lipid Peroxidation in Apoptosis, Autophagy, and Ferroptosis

Reactive oxygen species- (ROS-) induced lipid peroxidation plays a critical role in cell death including apoptosis, autophagy, and ferroptosis. This fundamental and conserved mechanism is based on an excess of ROS which attacks biomembranes, propagates lipid peroxidation chain reactions, and subsequently induces different types of cell death. A highly evolved sophisticated antioxidant system exists that acts to protect the cells from oxidative damage. In this review, we discussed how ROS propagate lipid peroxidation chain reactions and how the products of lipid peroxidation initiate apoptosis and autophagy in current models. We also discussed the mechanism of lipid peroxidation during ferroptosis, and we summarized lipid peroxidation in pathological conditions of critical illness. We aim to bring a more global and integrative sight to know how different ROS-induced lipid peroxidation occurs among apoptosis, autophagy, and ferroptosis.

Relationship between Selenium and Hematological Markers in Young Adults with Normal Weight or Overweight/Obesity

Selenium deficiency has been linked to anemia of inflammation, which is mediated by hepcidin. However, there are few studies providing evidence of the role of hepcidin in this relationship. In this study, we investigated the interrelationships among selenium biomarkers, hepcidin concentration, and iron status among individuals with overweight/obesity compared to their normal weight counterparts, since obesity is associated with chronic inflammation. A total of 59 college students were recruited for this study. Fasting blood samples were collected for the analysis of iron status, plasma selenoproteins (glutathione peroxidase (GPX) activity and selenoprotein P (SEPP1)), and plasma hepcidin. Subjects completed three-day dietary records to determine average daily nutrient intakes. SEPP1 concentration, GPX activity, and iron status biomarkers (serum iron, transferrin saturation, and hemoglobin concentration) were lower among individuals with overweight/obesity compared with individuals with normal weight, but these differences were not significant (p > 0.05). Regression analysis showed that GPX activity (β = −0.018, p = 0.008) and SEPP1 concentration (β = −1.24, p = 0.03) were inversely associated with hepcidin concentration. The inverse association between selenoproteins and hepcidin concentration supports a potential role of hepcidin as a mediator between selenium and iron status and warrants further studies to better understand this relationship.

Role of Cytosolic 2-Cys Prx1 and Prx2 in Redox Signaling

Peroxiredoxins (Prxs), a family of peroxidases, are reactive oxygen species scavengers that hydrolyze H₂O₂ through catalytic cysteine. Mammalian Prxs comprise six isoforms (typical 2-Cys Prxs; Prx1–4, atypical 2-Cys Prx; Prx5, and 1-Cys Prx; Prx6) that are distributed over various cellular compartments as they are classified according to the position and number of conserved cysteine. 2-Cys Prx1 and Prx2 are abundant proteins that are ubiquitously expressed mainly in the cytosol, and over 90% of their amino acid sequences are homologous. Prx1 and Prx2 protect cells from ROS-mediated oxidative stress through the elimination of H₂O₂ and regulate cellular signaling through redox-dependent mechanism. In addition, Prx1 and Prx2 are able to bind to a diversity of interaction partners to regulate other various cellular processes in cancer (i.e., regulation of the protein redox status, cell growth, apoptosis, and tumorigenesis). Thus, Prx1 and Prx2 can be potential therapeutic targets and it is particularly important to control their level or activity. This review focuses on cytosolic 2-Cys Prx1 and Prx2 and their role in the regulation of redox signaling based on protein-protein interaction.

Analysis of 1508 Plasma Samples by Capillary-Flow Data-Independent Acquisition Profiles Proteomics of Weight Loss and Maintenance

Comprehensive, high throughput analysis of the plasma proteome has the potential to enable holistic analysis of the health state of an individual. Based on our own experience and the evaluation of recent large-scale plasma mass spectrometry (MS) based proteomic studies, we identified two outstanding challenges: slow and delicate nano-flow liquid chromatography (LC) and irreproducibility of identification of data-dependent acquisition (DDA). We determined an optimal solution reducing these limitations with robust capillary-flow data-independent acquisition (DIA) MS. This platform can measure 31 plasma proteomes per day. Using this setup, we acquired a large-scale plasma study of the diet, obesity and genes dietary (DiOGenes) comprising 1508 samples. Proving the robustness, the complete acquisition was achieved on a single analytical column. Totally, 565 proteins (459 identified with two or more peptide sequences) were profiled with 74% data set completeness. On average 408 proteins (5246 peptides) were identified per acquisition (319 proteins in 90% of all acquisitions). The workflow reproducibility was assessed using 34 quality control pools acquired at regular intervals, resulting in 92% data set completeness with CVs for protein measurements of 10.9%.The profiles of 20 apolipoproteins could be profiled revealing distinct changes. The weight loss and weight maintenance resulted in sustained effects on low-grade inflammation, as well as steroid hormone and lipid metabolism, indicating beneficial effects. Comparison to other large-scale plasma weight loss studies demonstrated high robustness and quality of biomarker candidates identified. Tracking of nonenzymatic glycation indicated a delayed, slight reduction of glycation in the weight maintenance phase. Using stable-isotope-references, we could directly and absolutely quantify 60 proteins in the DIA.In conclusion, we present herein the first large-scale plasma DIA study and one of the largest clinical research proteomic studies to date. Application of this fast and robust workflow has great potential to advance biomarker discovery in plasma.

miR-1915-3p inhibits Bcl-2 expression in the development of gastric cancer

Many gene expressions changed during the development of gastric cancer, and non-coding RNAs including microRNAs (miRNAs) have been found to regulate cancer progression by participating in the process of tumor cell growth, migration, invasion and apoptosis. Our previous study has identified 29 miRNAs that are highly expressed in gastric cancer stem cells. One of these miRNAs, miR-1915-3p, has shown great potential as a diagnostic and prognostic biomarker for the cancers in liver, colon and thyroid, as well as in immune and kidney diseases. Herein, we found that miR-1915-3p exhibited low expression level in differentiated gastric cancer cell lines and gastric cancer tissues. It was found that the miR-1915-3p inhibited the growth of gastric cancer cells and thus promoted cell apoptosis. We discovered that the expressions of miR-1915-3p were significantly correlated to the lymph node metastasis and overall survival of patients with gastric cancer. Further study showed that there was a negative correlation between miR-1915-3p and Bcl-2 (B cell lymphoma/leukemia-2) expression, suggesting that Bcl-2 was a target gene of miR-1915-3p. Hence, miR-1915-3p possibly contributes to the development and progression of gastric cancer by inhibiting the anti-apoptotic protein Bcl-2. The finding provides a potential therapeutic strategy for gastric cancer.

Glutathione "Redox Homeostasis" and Its Relation to Cardiovascular Disease

More people die from cardiovascular diseases (CVD) than from any other cause. Cardiovascular complications are thought to arise from enhanced levels of free radicals causing impaired "redox homeostasis," which represents the interplay between oxidative stress (OS) and reductive stress (RS). In this review, we compile several experimental research findings that show sustained shifts towards OS will alter the homeostatic redox mechanism to cause cardiovascular complications, as well as findings that show a prolonged antioxidant state or RS can similarly lead to such cardiovascular complications. This experimental evidence is specifically focused on the role of glutathione, the most abundant antioxidant in the heart, in a redox homeostatic mechanism that has been shifted towards OS or RS. This may lead to impairment of cellular signaling mechanisms and elevated pools of proteotoxicity associated with cardiac dysfunction.

Selenium-Related Transcriptional Regulation of Gene Expression

The selenium content of the body is known to control the expression levels of numerous genes, both so-called selenoproteins and non-selenoproteins. Selenium is a trace element essential to human health, and its deficiency is related to, for instance, cardiovascular and myodegenerative diseases, infertility and osteochondropathy called Kashin–Beck disease. It is incorporated as selenocysteine to the selenoproteins, which protect against reactive oxygen and nitrogen species. They also participate in the activation of the thyroid hormone, and play a role in immune system functioning. The synthesis and incorporation of selenocysteine occurs via a special mechanism, which differs from the one used for standard amino acids. The codon for selenocysteine is a regular in-frame stop codon, which can be passed by a specific complex machinery participating in translation elongation and termination. This includes a presence of selenocysteine insertion sequence (SECIS) in the 3′-untranslated part of the selenoprotein mRNAs. Nonsense-mediated decay is involved in the regulation of the selenoprotein mRNA levels, but other mechanisms are also possible. Recent transcriptional analyses of messenger RNAs, microRNAs and long non-coding RNAs combined with proteomic data of samples from Keshan and Kashin–Beck disease patients have identified new possible cellular pathways related to transcriptional regulation by selenium.