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B cells play a critical role in immune responses both in physiological and pathological conditions, and microRNAs have been shown to play important roles in regulating B cell proliferation and function. MiR-146a has been shown to modulate T cell immunity, but its function in regulating B cell response remains partially understood. Our previous studies indicated that germinal center (GC) B cells are significantly expanded in miR-146a-overexpressing (TG) mice. In this study, we further characterized the roles of miR-146a in regulating humoral immune responses to specific antigens. We found that the production of IgE antibody were significantly elevated in TG mice, while the antibody affinity maturation of IgM and IgG were similar between TG mice and the normal controls. We further found higher IgE antibody levels in TG B cell culture supernatant than that in normal controls. A global protein expression comparison of B cells from TG mice and the normal controls through TMT proteomic assay showed that 14-3-3σ, a key factor of immunoglobulin class switch DNA recombination (CSR) in B cells, was highly up-regulated in B cells with overexpression of miR-146a, while Smad4, the target of miR-146a, was decreased. Using an asthma model induced by OVA immunization, we further confirmed the increased level of OVA specific IgE antibodies in TG mice. These results demonstrate that miR-146a enhances class switch and secretion of IgE in B cells by upregulating 14-3-3σ expression, and suggest that miR-146a may be a potential target for asthma therapy. [ABSTRACT FROM AUTHOR]

Alzheimer׳s disease (AD) is the most common form of dementia in the elderly. The recent evidence in AD research suggests that alterations in the microRNA (miRNA) could contribute to risk for the disease. However, little is understood about the roles of miRNAs in cognitive impairment of early Alzheimer׳s disease (AD). Here, we used 5-month-old APP/PS1 mice, which mimic many of the salient features of the early stage of AD pathological process, to further investigate the roles of miRNAs in synaptic loss involved in learning and memory. We used miRNA expression microarrays on RNA extracted from the hippocampus of 5-month-old APP/PS1 mice and wild type mice. Real-time reverse transcription PCR was conducted to verify the candidate miRNAs discovered by microarray analysis. The data showed that miR-574 was increased significantly in the hippocampus of 5-month-old APP/PS1 mice, which were concomitant with that APP/PS1 mice at the same age displayed a significant synaptic loss and cognitive deficits. Bioinformatic analysis predicted that neuritin (Nrn1) mRNA is targeted by miR-574. Overexpression of miR-574 lowers the levels of neuritin and synaptic proteins expression in primary hippocampal neurons damage induced by Aβ25-35. And the expression of miR-574 was also up-regulated in the hippocampal neurons from APP/PS1 mice compared with WT littermates. In contrast, suppression of miR-574 by miR-574 inhibitor significantly results in higher levels of neuritin and synaptic proteins expression. Taken together, miR-574 is involved in cognitive impairment in 5-month-old APP/PS1 mice through regulation of neuritin. [ABSTRACT FROM AUTHOR]

MiRNAs located at chromosome fragile sites play important roles in regulating critical genes associated with myeloma pathogenesis, disease progression and drug resistance. Our previous results have identified miR-33b (located in chromosome 17p) was one of the dysregulated miRNAs in the sera of newly diagnosed MM patients. However, little is known about its expression pattern in myeloma tumor cells and its prognostic value in MM patients. In the present study, we investigated the expression pattern of miR-33b in 58 newly diagnosed, 11 relapsed, 12 remission MM patients and 18 health donors by quantitative real-time PCR. Our results showed the expression of miR-33b was obviously down-regulated in newly diagnosed and relapsed MM patients compared to remission patients and health donors ( p < 0.001). Moreover, patients with del(13q), del(17p), t(4;14) and high-risk genetic abnormalities have lower expression levels of miR-33b compared to patients without those of abnormalities ( p = 0.032, 0.018, 0.034, 0.005). Survival analysis showed patients with miR-33b low expression had significantly shortened PFS ( p = 0.016) and OS ( p = 0.033) and might be associated with drug resistance to bortezomib-based treatment. Our data suggest that down-regulated miR-33b might be a novel predictor associated with disease progression and poor prognosis in MM. [ABSTRACT FROM AUTHOR]

As an important non-coding, evolutionary conserved, and post-transcriptional gene regulators of genome, microRNAs (miRNAs) have received extensive attention from various disciplines in the important role of biological processes and the connection with various diseases. It is also a new type of tumor marker with high specificity and sensitivity. Due to their important diagnostic values and crucial biological functions, miRNA detection attracts widespread interests. Due to the merits of low interference background, low cost, simple operation, fast response, inexpensive equipment, excellent sensitivity, and instrument miniaturization photoelectrochemical technique has been widely applied in the field of miRNA assay. As an important factor affecting the detection sensitivity, the signal amplification strategy is very important for PEC sensor. The purpose of this review is to introduce the signal amplification strategies involved into the PEC sensing filed for miRNA detection in the past five years, considering their advantages and disadvantages, and to open up new approaches in biological analysis and early disease diagnosis. The future prospects and current challenges are also discussed. • Comprehensive review for signal amplification strategy in photoelectrochemical biosensor for microRNA detection. • The detection principles of these biosensor were discussed based on different amplification strategies. • Highlight of photoelectrochemical biosensors for microRNA detection. • Future prospects in this field are discussed. [ABSTRACT FROM AUTHOR]

Cardiovascular disease (CVD) is the leading cause of mortality worldwide. Cardiac fibrosis is the scarring process occurs commonly with CVDs impairing the function and structure of heart. Herein, we investigated the role of circPAN3 in the pathogenesis of cardiac fibrosis. A rat myocardial infarction (MI) model was constructed to evaluate the role of circPAN3. Expression of circPAN3 in MI was determined, and si- circPAN3 was applied to verify its profibrotic effects. With an in vitro model, cardiac fibroblasts were stimulated by transforming growth factor beta 1 (TGFβ1). Immunofluorescent staining was employed to assess the fibrosis-related markers, as well as autophagy activity. CCK-8 and transwell assays were performed to determine cell proliferation and migration. Luciferase reporter assay and RNA pull-down were subjected to verify the interaction of circPAN3/miR-221. The enrichment of FoxO3 on the promoter region of ATG7 was detected using CHIP assay. Elevated circPAN3 was found in rat MI heart tissue, of which knockdown attenuated cardiac fibrosis after MI. In an in vitro model exposing with TGFβ1, increasing cell proliferation and migration were observed, whereas these effects were abolished by circPAN3 knockdown, as well as autophagy activity. miR-221 was identified as a target to be involved in circPAN3 -mediated cardiac fibrosis after MI. miR-221 negatively regulated FoxO3, thus causing the inhibition of ATG7 transcription. The regulatory network of circPAN3 / miR-221 /FoxO3/ATG7 in cardiac fibrosis was further determined in vivo. circPAN3 exhibited profibrotic effects during autophagy-mediated cardiac fibrosis via miR-221 /FoxO3/ATG7 axis, which may serve as potential biomarkers for cardiac fibrosis therapeutics. [ABSTRACT FROM AUTHOR]

Aims: The impaired angiogenesis is one of the main factors affecting the healing of diabetic foot ulcer (DFU) wounds. Maggot debridement therapy (MDT) promotes granulation tissue growth and angiogenesis during DFU wound healing. Non-coding microRNAs can also promote local angiogenesis in DFU wounds by regulating wound repairing related gene expression. The purpose of this study was to investigate the mechanism of microRNAs in MDT promoting DFU wound angiogenesis.Methods: In this study, we applied MDT to treat DFU wound tissue and detect the expression of the miR-17-92 cluster. In vitro experiments, human umbilical vein endothelial cells (HUVECs) were treated with maggot excretions/secretions (ES), the miR-17-92 cluster and the predicted target gene expression were measured. Tube formation assay and cell scratch assay were performed when inhibition of miR-18a/19a or overexpression of thrombospondin-1 (TSP-1) were used in this study.Results: miR-18a/19a transcription significantly up-regulated and TSP-1 expression down-regulated in patients wound tissue and in HUVECs. Inhibition of miR-18a/19a or overexpression of TSP-1 partially blocked the migration and tube formation ability stimulated by ES.Conclusion: Targeted activation of miR-18a/19a transcription levels and subsequent regulation of TSP-1 expression may be a novel therapeutic strategy for DFU. [ABSTRACT FROM AUTHOR]

Objective For the purpose of an early identification of intervention targets for acute spinal cord injury (ASCI), we investigated the changes in expression levels of microRNA-9 (miR-9) and MCPIP1 in rat ASCI model. Method A total of 108 healthy rats were randomly divided into non-ASCI group ( n = 18) and five ASCI groups, 6 h, 12 h, 24 h, 3 days and 7 days, representing the experimental time points following ASCI ( n = 18 per group). Hematoxylin and eosin (HE) staining was used to assess the ASCI damage, and quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH) were employed for the detection of miR-9 and MCPIP1 mRNA expression. Results HE staining results showed normal neuronal morphology in the non-ASCI group, but spinal cord tissue at 6 h after ASCI showed developing neuronal necrosis. Acute inflammatory response was evident at 12 h and 24 h, with immune cells infiltrating into the gray matter. Vascular permeability increased and the nerve cells in gray-white matter exhibited extensive damage and necrosis at 24 h and 7 days after ASCI. MiR-9 expression in ASCI tissue was significantly lower than that in normal spinal cord tissue. Statistical analysis showed a significant decrease in miR-9 expression in all the ASCI groups, compared to the non-ASCI group. Results from real-time PCR analysis revealed that MCPIP1 expression in all the ASCI groups was significantly higher than the non-ASCI group, and MCPIP1 expressions gradually increased with times at 6h–24 h after ASCI. ISH revealed the following results after ASCI (1) miR-9 and MCPIP1 mRNA expression mainly distributed in ventral horn motor neurons, (2) miR-9 expression was high at 7 day after ASCI and (3) in the non-ASCI group, MCPIP1 expression was high at 6 h, 12 h, 24 h and 3 days. Conclusion MCPIP1 is significantly up-regulated after ASCI. The negative relationship between MCPIP1 and miR-9 suggest that MCPIP1 mRNA could be a target of miR-9 during ASCI. Thus, miR-9 is a marker for apoptosis in neurons, and an excellent therapeutic target for ASCI patients. [ABSTRACT FROM AUTHOR]

Abstract: MicroRNAs (miRNA) participate in regulating diverse biological pathways by translational repression in animals. They have attracted increasing attention recently. However, little work has been done on the miRNA genes in agriculturally important pests. Because the transcripts of most miRNA genes are the products of type-II RNA polymerase, pri-miRNA has a poly(A) tail and appears in expressed sequence tags (EST). We developed a computational pipeline to identify miRNA genes from insect ESTs. First, 980,697 ESTs from 63 insects were collected and used to search the nr database. The ESTs which did not share significant similarities with any known protein-coding genes were treated as non-coding ESTs. Next, known mature miRNAs were used to align with non-coding ESTs. The ESTs which contain the sequence of mature miRNA were treated as candidate ESTs. Finally, putative precursors were extracted flanking the mature miRNA region in candidate ESTs and evaluated by the Triplet-SVM algorithm. As a result, 86 miRNAs from 30 insect species were found based on a strict criterion while 330 miRNAs from 51 species were found based on a loose criterion. Evolution analysis indicated that mir-467, mir-297 and mir-466 were the highest conserved miRNA families in insects. To confirm the reliability of putative insect miRNAs, the expression profile of nine predicted miRNAs in Locusta migratoria was investigated. Eight miRNAs were successfully detected by RT-PCR. Most miRNAs were expressed ubiquitously at all examined tissues and developmental stages whereas Lmi-mir-509 was specifically expressed in the thorax of the 2nd, 4th and 5th instars and adult locust. In all, our work reported an efficient computational strategy for predicting miRNA genes from insect ESTs and presented tens of miRNAs in diverse insect species which are expected to participate in many important physiological processes. [ABSTRACT FROM AUTHOR]