Dietary miR-451 protects erythroid cells from oxidative stress via increasing the activity of Foxo3 pathway

MicroRNAs-associated with FOXO3 in cellular senescence and other stress responses

FOXO3 is a member of the FOXO transcription factor family and is known for regulating cellular survival in response to stress caused by various external and biological stimuli. FOXO3 decides cell fate by modulating cellular senescence, apoptosis and autophagy by transcriptional regulation of genes involved in DNA damage response and oxidative stress resistance. These cellular processes are tightly regulated physiologically, with FOXO3 acting as the hub that integrates signalling networks controlling them. The activity of FOXO3 is influenced by post-translational modifications, altering its subcellular localisation. In addition, FOXO3 can also be regulated directly or indirectly by microRNAs (miRNAs) or vice versa. This review discusses the involvement of various miRNAs in FOXO3-driven cellular responses such as senescence, apoptosis, autophagy, redox and inflammation defence. Given that these responses are linked and influence cell fate, a thorough understanding of the complex regulation by miRNAs would provide key information for developing therapeutic strategy and avoid unintended consequences caused by off-site targeting of FOXO3.

The Role of microRNAs in Arsenic-Induced Human Diseases: A Review

MicroRNAs (miRNAs) are noncoding RNAs with 20-22 nucleotides, which are encoded by endogenous genes and are capable of targeting the majority of human mRNAs. Arsenic is regarded as a human carcinogen, which can lead to many adverse health effects including diabetes, skin lesions, kidney disease, neurological impairment, male reproductive injury, and cardiovascular disease (CVD) such as cardiac arrhythmias, ischemic heart failure, and endothelial dysfunction. miRNAs can act as tumor suppressors and oncogenes via directly targeting oncogenes or tumor suppressors. Recently, miRNA dysregulation was considered to be an important mechanism of arsenic-induced human diseases and a potential biomarker to predict the diseases caused by arsenic exposure. Endogenic miRNAs such as miR-21, the miR-200 family, miR-155, and the let-7 family are involved in arsenic-induced human disease by inducing translational repression or RNA degradation and influencing multiple pathways, including mTOR/Arg 1, HIF-1α/VEGF, AKT, c-Myc, MAPK, Wnt, and PI3K pathways. Additionally, exogenous miRNAs derived from plants, such as miR-34a, miR-159, miR-2911, miR-159a, miR-156c, miR-168, etc., among others, can be transported from blood to specific tissue/organ systems in vivo. These exogenous miRNAs might be critical players in the treatment of human diseases by regulating host gene expression. This review summarizes the regulatory mechanisms of miRNAs in arsenic-induced human diseases, including cancers, CVD, and other human diseases. These special miRNAs could serve as potential biomarkers in the management and treatment of human diseases linked to arsenic exposure. Finally, the protective action of exogenous miRNAs, including antitumor, anti-inflammatory, anti-CVD, antioxidant stress, and antivirus are described.

Targeting MicroRNA-144/451-AKT-GSK3β Axis Affects the Proliferation and Differentiation of Radial Glial Cells in the Mouse Hippocampal Dentate Gyrus

It is well known that aging induces a progressive decline in the proliferation and neural differentiation of radial glial cells (RGCs) in the hippocampal dentate gyrus (DG). The function of miR-144/451 is to activate stress-regulated molecular gene expression switches for cell proliferation and differentiation. We found that the miR-144/451 expression in the hippocampus was significantly reduced in aged mice compared to adult mice. Furthermore, the proliferation and neural differentiation of RGCs in the mouse hippocampal DG was decreased by miR-144/451 knockout (miR-144/451^-/-). Antioxidant agents, superoxide dismutases (SODs) and catalase, and the expression of melatonin's receptor in the hippocampus were decreased in the miR-144/451^-/- mice. In addition, the (protein kinase B) AKT/(glycogen synthase kinase 3β) GSK3β/(catenin beta-1) β-catenin signaling pathway was weakly activated in the hippocampus of miR-144/451^-/- mice, which was related to brain neurogenesis. Melatonin treatment improved the expression of miR-144/451 and antioxidant enzymes and activated the AKT/GSK3β/β-catenin pathway in the hippocampus of miR-144/451^-/- mice. When the AKT pathway was inhibited by LY294002, the neurogenerative and antioxidant effects of melatonin were significantly limited in the hippocampus of miR-144/451^-/- mice. In brief, our results indicated that miR-144/451 plays crucial roles in the proliferation and neural differentiation of RGCs via the regulation of the antioxidant and AKT/GSK3β/β-catenin pathways.

Exosomes provide unappreciated carrier effects that assist transfers of their miRNAs to targeted cells; I. They are 'The Elephant in the Room'

Extracellular vesicles (EV), such as exosomes, are emerging biologic entities that mediate important newly recognized functional effects. Exosomes are intracellular endosome-originating, cell-secreted, small nano-size EV. They can transfer cargo molecules like miRNAs to act intracellularly in targeted acceptor cells, to then mediate epigenetic functional alterations. Exosomes among EV, are universal nanoparticles of life that are present across all species. Some critics mistakenly hold exosomes to concepts and standards of cells, whereas they are subcellular nanospheres that are a million times smaller, have neither nuclei nor mitochondria, are far less complex and currently cannot be studied deeply and elegantly by many and diverse technologies developed for cells over many years. There are important concerns about the seeming impossibility of biologically significant exosome transfers of very small amounts of miRNAs resulting in altered targeted cell functions. These hesitations are based on current canonical concepts developed for non-physiological application of miRNAs alone, or artificial non-quantitative genetic expression. Not considered is that the natural physiologic intercellular transit via exosomes can contribute numerous augmenting carrier effects to functional miRNA transfers. Some of these are particularly stimulated complex extracellular and intracellular physiologic processes activated in the exosome acceptor cells that can crucially influence the intracellular effects of the transferred miRNAs. These can lead to molecular chemical changes altering DNA expression for mediating functional changes of the targeted cells. Such exosome mediated molecular transfers of epigenetic functional alterations, are the most exciting and life-altering property that these nano EV bring to virtually all of biology and medicine. .Abbreviations: Ab, Antibody Ag Antigen; APC, Antigen presenting cells; CS, contact sensitivity; DC, Dendritic cells; DTH, Delayed-type hypersensitivity; EV, extracellular vesicles; EV, Extracellular vesicle; FLC, Free light chains of antibodies; GI, gastrointestinal; IP, Intraperitoneal administration; IV, intravenous administration; OMV, Outer membrane vesicles released by bacteria; PE, Phos-phatidylethanolamine; PO, oral administration.

Plant-derived xenomiRs and cancer: Cross-kingdom gene regulation

Exosomal microRNAs (miRNAs) critically regulate several major intracellular and metabolic activities, including cancer evolution. Currently, increasing evidence indicates that exosome harbor and transport these miRNAs from donor cells to neighboring and distantly related recipient cells, often in a cross-species manner. Several studies have reported that plant-based miRNAs can be absorbed into the serum of humans, where they hinder the expression of human disease-related genes. Moreover, few recent studies have demonstrated the role of these xenomiRs in cancer development and progression. However, the cross-kingdom gene regulation hypothesis remains highly debatable, and many follow up studies fail to reproduce the same. There are reports that show no effect of plant-derived miRNAs on mammalian cancers. The foremost cause of this controversy remains the lack of reproducibility of the results. Here, we reassess the latest developments in the field of cross-kingdom transference of miRNAs, emphasizing on the role of the diet-based xenomiRs on cancer progression.

Eating microRNAs: pharmacological opportunities for cross-kingdom regulation and implications in host gene and gut microbiota modulation

Cross-kingdom communication via non-coding RNAs is a recent discovery. Exogenous microRNAs (exog-miRNAs) mainly enter the host via the diet. Generally considered unstable in the gastrointestinal tract, some exogenous RNAs may resist these conditions, especially if transported in extracellular vesicles. They could then reach the intestines and more probably exert a regulatory effect. We give an overview of recent discoveries concerning dietary miRNAs, possible ways of enhancing their resistance to food processing and gut conditions, their transport in extracellular vesicles (animal- and plant-origin) and possible biological effects on recipient cells after ingestion. We critically focus on what we believe are the most relevant data for future pharmacological development of dietary miRNAs as therapeutic agents. Finally, we discuss the miRNA-mediated cross-kingdom regulation between diet, host and the gut microbiota. We conclude that, despite many obstacles and challenges, extracellular miRNAs are serious candidates to be targeted pharmacologically for development of new therapeutic agents.

Erythroid microRNA and oxidant status alterations in l-thyroxine-induced hyperthyroid rats: effects of selenium supplementation

BACKGROUND

Hypermetabolic state in hyperthyroidism causes oxidative stress. Erythrocytes are the cells that are involved in oxidant equilibrium in an organism and contain microRNA (miRNA). Selenium, which is an essential element for an organism, has antioxidant properties. The present study was aimed at investigating the effects of selenium supplementation in hyperthyroidism, on pro- and antioxidant enzymes, and miRNA (miR-144 and miR-451) expressions in the erythrocytes.

METHODS

Forty-eight Sprague-Dawley male rats were divided into 6 groups; control group, group fed with 0.5 mg/kg sodium selenite; group fed with 1 mg/kg sodium selenite; hyperthyroid group; hyperthyroid group fed with 0.5 mg/kg sodium selenite; and hyperthyroid group fed with 1 mg/kg sodium selenite. Malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), miR-144, and miR-451 expression levels were studied in erythrocyte hemolysates.

RESULTS

MDA levels were increased in the hyperthyroid group compared to the control group, and the group fed with 0.5 mg/kg sodium selenite (P<0.001 and P<0.01, respectively). GSH levels were increased in the hyperthyroid group and the hyperthyroid group fed with 0.5 mg/kg sodium selenite compared to the control group (P<0.001, and P<0.05, respectively). GSH levels of the hyperthyroid group fed with 1 mg/kg sodium selenite were decreased when compared with the hyperthyroid group (P<0.05). SOD levels of the hyperthyroid group were increased when compared with the control group (P<0.05, and P<0.001, respectively). Similarly, SOD levels of the hyperthyroid group fed with 1 mg/kg sodium selenite were lower than the hyperthyroid group (P<0.01). miR-144 values were increased in the hyperthyroid group and the hyperthyroid group fed with 0.5 mg/kg sodium selenite compared to the control group (P<0.001, and P<0.05 respectively). miR-451 expression was increased significantly in the hyperthyroid group compared to the control group (P<0.05).

CONCLUSIONS

Our findings showed that MDA, SOD and GSH levels increased, and miR-144 and miR-451 expressions changed in hyperthyroidism. Supplementation of 1 mg/kg sodium selenite was more effective than 0.5 mg/kg sodium selenite for normalizing the MDA, GSH, SOD, and miRNA levels in the hyperthyroid group.

Deletion of MicroRNA-144/451 Cluster Aggravated Brain Injury in Intracerebral Hemorrhage Mice by Targeting 14-3-3ζ

This study aims at evaluating the importance and its underlying mechanism of the cluster of microRNA-144/451 (miR-144/451) in the models with intracerebral hemorrhage (ICH). A model of collagenase-induced mice with ICH and a model of mice with simple miR-144/451 gene knockout (KO) were used in this study. Neurodeficits and the water content of the brain of the mice in each group were detected 3 days after collagenase injection. The secretion of proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β), as well as certain biomarkers of oxidative stress, was determined in this study. The results revealed that the expression of miR-451 significantly decreased in the mice with ICH, whereas miR-144 showed no significant changes. KO of the cluster of miR-144/451 exacerbated the neurological deficits and brain edema in the mice with ICH. Further analyses demonstrated that the KO of the cluster of miR-144/451 significantly promoted the secretion of TNF-α and IL-1β and the oxidative stress in the perihematomal region of the mice with ICH. In addition, the miR-144/451's depletion inhibited the regulatory axis' activities of miR-451-14-3-3ζ-FoxO3 in the mice with ICH. In conclusion, these data demonstrated that miR-144/451 might protect the mice with ICH against neuroinflammation and oxidative stress by targeting the pathway of miR-451-14-3-3ζ-FoxO3.

Roles of Regulatory RNAs in Nutritional Control

Small RNAs (sRNAs), including microRNAs (miRNAs), are noncoding RNA (ncRNA) molecules involved in gene regulation. sRNAs play important roles in development; however, their significance in nutritional control and as metabolic modulators is still emerging. The mechanisms by which diet impacts metabolic genes through miRNAs remain an important area of inquiry. Recent work has established how miRNAs are transported in body fluids often within exosomes, which are small cell-derived vesicles that function in intercellular communication. The abundance of other recently identified ncRNAs and new insights regarding ncRNAs as dietary bioactive compounds could remodel our understanding about how foods impact gene expression. Although controversial, some groups have shown that dietary RNAs from plants and animals (i.e., milk) are functional in consumers. In the future, regulating sRNAs either directly through dietary delivery or indirectly by altered expression of endogenous sRNA may be part of nutritional interventions for regulating metabolism.

Cross-Kingdom Regulation by Plant microRNAs Provides Novel Insight into Gene Regulation

microRNAs (miRNAs) are well known as major players in mammalian and plant genetic systems that act by regulating gene expression at the post-transcriptional level. These tiny molecules can regulate target genes (mRNAs) through either cleavage or translational inhibition. Recently, the discovery of plant-derived miRNAs showing cross-kingdom abilities to regulate mammalian gene expression has prompted exciting discussions among researchers. After being acquired orally through the diet, plant miRNAs can survive in the digestive tract, enter the circulatory system, and regulate endogenous mRNAs. Here, we review current knowledge regarding the cross-kingdom mechanisms of plant miRNAs, related controversies, and potential applications of these miRNAs in dietary therapy, which will provide new insights for plant miRNA investigations related to health issues in humans.

miR-144/451 inhibits c-Myc to promote erythroid differentiation

Ablation of miR-144/451 disrupts homeostasis of erythropoiesis. Myc, a protooncogenic protein, is essential for erythroblast proliferation but commits rapid downregulation during erythroid maturation. How erythroblasts orchestrate maturation processes through coding and non-coding genes is largely unknown. In this study, we use miR-144/451 knockout mice as in vivo model, G1E, MEL erythroblast lines and erythroblasts from fresh mouse fetal livers as in vitro systems to demonstrate that targeted depletion of miR-144/451 blocks erythroid nuclear condensation and enucleation. This is due, at least in part, to the continued high expression of Myc in erythroblasts when miR-144/451 is absent. Specifically, miR-144/451 directly inhibits Myc in erythroblasts. Loss of miR-144/451 locus derepresses, and thus, increases the expression of Myc. Sustained high levels of Myc in miR-144/451-depleted erythroblasts blocks erythroid differentiation. Moreover, Myc reversely regulates the expression of miR-144/451, forming a positive miR-144/451-Myc feedback to ensure the complete shutoff of Myc during erythropoiesis. Given that erythroid-specific transcription factor GATA1 activates miR-144/451 and inactivates Myc, our findings indicate that GATA1-miR-144/451-Myc network safeguards normal erythroid differentiation. Our findings also demonstrate that disruption of the miR-144/451-Myc crosstalk causes anemia, suggesting that miR-144/451 might be a potential therapeutic target in red cell diseases.

MicroRNA sequencing of rat hippocampus and human biofluids identifies acute, chronic, focal and diffuse traumatic brain injuries

High-throughput sequencing technologies could improve diagnosis and classification of TBI subgroups. Because recent studies showed that circulating microRNAs (miRNAs) may serve as noninvasive markers of TBI, we performed miRNA-seq to study TBI-induced changes in rat hippocampal miRNAs up to one year post-injury. We used miRNA PCR arrays to interrogate differences in serum miRNAs using two rat models of TBI (controlled cortical impact [CCI] and fluid percussion injury [FPI]). The translational potential of our results was evaluated by miRNA-seq analysis of human control and TBI (acute and chronic) serum samples. Bioinformatic analyses were performed using Ingenuity Pathway Analysis, miRDB, and Qlucore Omics Explorer. Rat miRNA profiles identified TBI across all acute and chronic intervals. Rat CCI and FPI displayed distinct serum miRNA profiles. Human miRNA profiles identified TBI across all acute and chronic time points and, at 24 hours, discriminated between focal and diffuse injuries. In both species, predicted gene targets of differentially expressed miRNAs are involved in neuroplasticity, immune function and neurorestoration. Chronically dysregulated miRNAs (miR-451a, miR-30d-5p, miR-145-5p, miR-204-5p) are linked to psychiatric and neurodegenerative disorders. These data suggest that circulating miRNAs in biofluids can be used as "molecular fingerprints" to identify acute, chronic, focal or diffuse TBI and potentially, presence of neurodegenerative sequelae.

Dietary microRNA-A Novel Functional Component of Food

MicroRNAs are a class of small RNAs that play essential roles in various biological processes by silencing genes. Evidence emerging in recent years suggests that microRNAs in food can be absorbed into the circulatory system and organs of humans and other animals, where they regulate gene expression and biological processes. These food-derived dietary microRNAs may serve as a novel functional component of food, a role that has been neglected to date. However, a significant amount of evidence challenges this new concept. The absorption, stability, and physiological effects of dietary microRNA in recipients, especially in mammals, are currently under heavy debate. In this review, we summarize our current understanding of the unique characteristics of dietary microRNAs and concerns about both the mechanistic and methodological basis for studying the biological significance of dietary microRNAs. Such efforts will benefit continuing investigations and offer new perspectives for the interpretation of the roles of dietary microRNA with respect to the health and disease of humans and animals.

MicroRNAs from plants to animals, do they define a new messenger for communication?

MicroRNAs (miRNAs), a class of single-stranded non-coding RNA of about 22 nucleotides, are potent regulators of gene expression existing in both plants and animals. Recent studies showed that plant miRNAs could enter mammalian bloodstream via gastrointestinal tract, through which access a variety of tissues and cells of recipients to exert therapeutic effects. This intriguing phenomenon indicates that miRNAs of diet/plant origin may act as a new class of bioactive ingredients communicating with mammalian systems. In this review, in order to pinpoint the reason underlying discrepancies of miRNAs transmission from diet/plant to animals, the pathways that generate miRNAs and machineries involved in the functions of miRNAs in both kingdoms were outlined and compared. Then, the current controversies concerning cross-kingdom regulations and the potential mechanisms responsible for absorption and transfer of diet/plant-derived miRNAs were interpreted. Furthermore, the hormone-like action of miRNAs and the intricate interplay between miRNAs and hormones were implicated. Finally, how these findings may impact nutrition and medicine were briefly discussed.

Plant MicroRNAs in Cross-Kingdom Regulation of Gene Expression

MicroRNAs (miRNAs) are a class of noncoding small RNAs, which play a crucial role in post-transcriptional gene regulation. Recently, various reports revealed that miRNAs could be transmitted between species to mediate cross-kingdom regulation by integrating into a specific target gene-mediated regulatory pathway to exert relevant biological functions. Some scholars and researchers have observed this as an attractive hypothesis that may provide a foundation for novel approaches in the diagnosis, prognosis, and treatment of disease. Meanwhile, others deem the mentioned results were obtained from a “false positive effect” of performed experiments. Here, we focus on several current studies concerning plant miRNA-mediated cross-kingdom regulation (from both fronts) and discuss the existing issues that need further consideration. We also discuss possible miRNA horizontal transfer mechanisms from one species to another and analyze the relationship between miRNA-mediated cross-kingdom regulation and coevolution during a long-term specific host–pathogen interaction.