Adolescent ; Cardiac Catheterization ; methods ; Child, Preschool ; Echocardiography, Transesophageal ; methods ; Female ; Heart Septal Defects, Atrial ; diagnostic imaging ; therapy ; Humans ; Treatment Outcome

A new class of RNA regulatory genes known as microRNAs (miRNAs) has been found to introduce a whole new layer of gene regulation in eukaryotes. The intensive studies of the past several years have demonstrated that miRNAs are not only found intracellularly, but are also detectable outside cells, including in various body fluids (e.g. serum, plasma, saliva, urine and milk). This phenomenon raises questions about the biological function of such extracellular miRNAs. Substantial amounts of extracellular miRNAs are enclosed in small membranous vesicles (e.g. exosomes, shedding vesicles and apoptotic bodies) or packaged with RNA-binding proteins (e.g. high-density lipoprotein, Argonaute 2 and nucleophosmin 1). These miRNAs may function as secreted signaling molecules to influence the recipient cell phenotypes. Furthermore, secreted extracellular miRNAs may reflect molecular changes in the cells from which they are derived and can therefore potentially serve as diagnostic indicators of disease. Several studies also point to the potential application of siRNA/miRNA delivery as a new therapeutic strategy for treating diseases. In this review, we summarize what is known about the mechanism of miRNA secretion. In addition, we describe the pathophysiological roles of secreted miRNAs and their clinical potential as diagnostic biomarkers and therapeutic drugs. We believe that miRNA transfer between cells will have a significant impact on biological research in the coming years.
Animals ; Diagnosis ; Extracellular Space ; genetics ; Gene Transfer, Horizontal ; Humans ; MicroRNAs ; genetics ; metabolism ; Therapeutics

MicroRNAs (miRNAs) are endogenously expressed small, non-coding transcripts that regulate protein expression. Substantial evidences suggest that miRNAs are enriched in central nervous system, where they are hypothesized to play pivotal roles during neural development. In the present study, we analyzed miRNAs expression in mice cerebral cortex and hippocampus at different developmental stages and found miR-29a increased dramatically at postnatal stages. In addition, we provided strong evidences that miR-29a is enriched in mature neurons both in vitro and in vivo. Further investigation demonstrated that the activation of glutamate receptors induced endogenous miR-29a level in primary neurons. Moreover, we showed that miR-29a directly regulated its target protein Doublecortin (DCX) expression, which further modulated axon branching in primary culture. Together, our results suggested that miR-29a play an important role in neuronal development of mice cerebrum.
Animals ; Axons ; metabolism ; physiology ; Hippocampus ; growth & development ; metabolism ; Mice ; MicroRNAs ; genetics ; metabolism ; Microtubule-Associated Proteins ; genetics ; Neurogenesis ; Neurons ; metabolism ; Neuropeptides ; genetics ; Primary Cell Culture

The mechanism underlying T cell-mediated fulminant hepatitis is not fully understood. In this study, we investigated whether myeloid derived suppressor cells (MDSCs) could prevent the concanavalin A (ConA)-induced hepatitis through suppressing T cell proliferation. We observed an increase in the frequencies of MDSCs in mouse spleen and liver at early stage of ConA treatment, implicating that the MDSCs might be involved in the initial resistance of mice against ConA-mediated inflammation. Subpopulation analysis showed that the MDSCs in liver of ConA-induced mice were mainly granulocytic MDSCs. Adoptive transfer of the bone marrow-derived MDSCs into ConA-treated mice showed that the MDSCs migrated into the liver and spleen where they suppressed T cell proliferation through ROS pathway. In addition, the frequencies of MDSCs in mice were also significantly increased by the treatment with immune suppressor glucocorticoids. Transfer of MDSCs into the regulatory T cell (Treg)-depleted mice showed that the protective effect of MDSCs on ConA-induced hepatitis is Treg-independent. In conclusion, our results demonstrate that MDSCs possess a direct protective role in T cell-mediated hepatitis, and increasing the frequency of MDSCs by either adoptive transfer or glucocorticoid treatment represents a potential cell-based therapeutic strategy for the acute inflammatory disease.
Adoptive Transfer ; Animals ; Blotting, Western ; Bone Marrow Cells ; immunology ; CD11b Antigen ; immunology ; metabolism ; Cell Movement ; immunology ; Cell Proliferation ; Chemical and Drug Induced Liver Injury ; etiology ; immunology ; prevention & control ; Concanavalin A ; toxicity ; Dexamethasone ; pharmacology ; Flow Cytometry ; Glucocorticoids ; pharmacology ; Liver ; immunology ; pathology ; Male ; Mice, Inbred C57BL ; Mitogens ; administration & dosage ; toxicity ; Myeloid Cells ; immunology ; metabolism ; transplantation ; Receptors, Chemokine ; immunology ; metabolism ; Spleen ; immunology ; pathology ; T-Lymphocytes ; immunology ; T-Lymphocytes, Regulatory ; immunology

MicroRNAs (miRNAs) are small non-coding RNAs (ncRNAs) that are involved in post-transcriptional gene regulation. It has long been assumed that miRNAs exert their roles only in the cytoplasm, where they recognize their target protein-coding messenger RNAs (mRNAs), and result in translational repression or target mRNA degradation. Recent studies, however, have revealed that mature miRNAs can also be transported from the cytoplasm to the nucleus and that these nuclear miRNAs can function in an unconventional manner to regulate the biogenesis and functions of ncRNAs (including miRNAs and long ncRNAs), adding a new layer of complexity to our understanding of gene regulation. In this review, we summarize recent literature on the working model of these unconventional miRNAs and speculate on their biological significance. We have every reason to believe that these novel models of miRNA function will become a major research topic in gene regulation in eukaryotes.
Cell Nucleus ; genetics ; Cytoplasm ; genetics ; Eukaryota ; genetics ; Gene Expression Regulation ; Humans ; MicroRNAs ; genetics ; RNA Stability ; genetics ; RNA, Long Noncoding ; genetics ; RNA, Messenger ; genetics ; metabolism

Animals ; Biomarkers ; blood ; cerebrospinal fluid ; metabolism ; Brain ; metabolism ; Cell Line ; Cell Movement ; Central Nervous System ; metabolism ; Exocytosis ; Humans ; Mice ; MicroRNAs ; blood ; cerebrospinal fluid ; metabolism ; Secretory Vesicles ; metabolism

Colostrum provides essential nutrients and immunologically active factors that are beneficial to newborns. Our previous work demonstrated that milk contains large amounts of miRNA that is largely stored in milk-derived microvesicles (MVs). In the present study, we found that the MVs from colostrum contain significantly higher levels of several immune-related miRNAs. We hypothesized that the colostrum MVs may transfer the immune-related miRNAs into cells, which contribute to its immune modulatory feature. We isolated colostrum MVs by ultracentrifugation and demonstrated several immune modulation features associated with miRNAs. We also provide evidence that the physical structure of milk-derived MVs is essential for transfer miRNAs and following immune modulation effect. Moreover, we found that colostrum powder-derived MVs also contains higher levels of immune-related miRNAs that display similar immune modulation effects. Taken together, these results show that MV-containing immunerelated miRNAs may be a novel mechanism by which colostrum modulates body immune response.
Animals ; Cattle ; Cell Movement ; Cell Proliferation ; Colostrum ; metabolism ; Cytokines ; metabolism ; Female ; Liposomes ; chemistry ; isolation & purification ; metabolism ; Macrophages ; immunology ; metabolism ; Mice ; MicroRNAs ; immunology ; metabolism ; Milk ; immunology ; metabolism ; Phagocytosis ; Pregnancy ; Ultracentrifugation

Avian Myeloblastosis Virus ; enzymology ; Escherichia coli ; genetics ; metabolism ; Genome, Bacterial ; MicroRNAs ; metabolism ; RNA-Directed DNA Polymerase ; genetics ; metabolism ; Real-Time Polymerase Chain Reaction ; Sequence Analysis, RNA

MicroRNAs (miRNAs) are small, non-coding RNAs that function as post-transcriptional regulators of gene expression. The deregulated expression of miRNAs is associated with a variety of diseases, including breast cancer. In the present study, we found that miR-495 was markedly up-regulated in clinical breast cancer samples by quantitative real time-PCR (qRT-PCR). Junctional adhesion molecule A (JAM-A) was predicted to be a potential target of miR-495 by bioinformatics analysis and was subsequently verified by luciferase assay and Western blotting. JAM-A was found to be negatively correlated with the migration of breast cancer cells through loss-of-function and gain-of-function assays, and the inhibition of JAM-A by miR-495 promoted the migration of MCF-7 and MDA-MB-231 cells. Furthermore, overexpression of JAM-A could restore miR-495-induced breast cancer cell migration. Taken together, our findings suggest that miR-495 could facilitate breast cancer progression through the repression of JAM-A, making this miRNA a potential therapeutic target.
3' Untranslated Regions ; genetics ; Adult ; Aged ; Blotting, Western ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Adhesion Molecules ; genetics ; metabolism ; Cell Line, Tumor ; Cell Movement ; genetics ; Female ; Gene Expression Regulation, Neoplastic ; Gene Knockdown Techniques ; Humans ; MCF-7 Cells ; MicroRNAs ; genetics ; Middle Aged ; RNA Interference ; Receptors, Cell Surface ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

Amniotic Fluid ; drug effects ; metabolism ; Female ; Fetus ; drug effects ; metabolism ; Gene Expression Regulation, Developmental ; drug effects ; genetics ; Humans ; MicroRNAs ; genetics ; pharmacology ; Placenta ; metabolism ; Pregnancy ; RNA, Plant ; genetics ; pharmacology ; Umbilical Cord ; drug effects ; metabolism