miR-21 Target Research Articles

Microglia-derived exosomal circZNRF1 alleviates paraquat-induced neuronal cell damage via miR-17-5p

Paraquat (PQ) is an environmental poison that causes clinical symptoms similar to those of Parkinson's disease (PD) in vitro and in rodents. It can lead to the activation of microglia and apoptosis of dopaminergic neurons. However, the exact role and mechanism of microglial activation in PQ-induced neuronal degeneration remain unknown. Here, we isolated the microglia-derived exosomes exposed with 0 and 40 μM PQ, which were subsequently co-incubated with PQ-exposed neuronal cells to simulate intercellular communication. First, we found that exosomes released from microglia caused a change in neuronal cell vitality and reversed PQ-induced neuronal apoptosis. RNA sequencing data showed that these activated microglia-derived exosomes carried large amounts of circZNRF1. Moreover, a bioinformatics method was used to study the underlying mechanism of circZNRF1 in regulating PD, and miR-17–5p was predicted to be its target. Second, an increased Bcl2/Bax ratio could play an anti-apoptotic role. Bcl2 was predicted to be a downstream target of miR-17–5p. Our results showed that circZNRF1 plays an anti-apoptotic role by absorbing miR-17–5p and regulating the binding of Bcl2 after exosomes are internalized by dopaminergic neurons. In conclusion, we demonstrated a new intercellular communication mechanism between microglia and neurons, in which circZNRF1 plays a key role in protecting against PQ-induced neuronal apoptosis through miR-17–5p to regulate the biological process of PD. These findings may offer a novel approach to preventing and treating PD.

SIRT1 promotes the progression and chemoresistance of colorectal cancer through the p53/miR-101/KPNA3 axis

ABSTRACT Introduction Sirtuin 1 (SIRT1) is a key modulator in several types of cancer, including colorectal cancer (CRC). Here, we probed into the molecular mechanism of SIRT1 regulating the development and chemoresistance of CRC. Methods Differentially expressed genes related to the growth, metastasis and chemoresistance of CRC were identified by bioinformatics analysis. The expression of SIRT1 in clinical tissues from CRC patients and CRC cell lines was detected by RT-qPCR. Interactions among SIRT1, p53, miR-101 and KPNA3 were analyzed. The effect of SIRT1 on the cell viability, migration, invasion, epithelial-mesenchymal transformation and chemoresistance to 5-FU was evaluated using loss-function investigations in CRC cells. Finally, a xenograft model of CRC and a metastasis model were constructed for further exploration of the roles of SIRT1 in vivo. Results SIRT1 was elevated in CRC tissues and cell lines. SIRT1 decreased p53 via deacetylation, and consequently downregulated the expression of miR-101 while increasing that of the miR-101 target gene KPNA3. By this mechanism, SIRT1 enhanced the proliferation, migration, invasion, epithelial-mesenchymal transformation, and resistance to 5-FU of CRC cells. In addition, in vivo data also showed that SIRT1 promoted the growth, metastasis and chemoresistance to 5-FU of CRC cells via regulation of the p53/miR-101/KPNA3 axis. Conclusions In conclusion, SIRT1 can function as an oncogene in CRC by accelerating the growth, metastasis and chemoresistance to 5-FU of CRC cells through the p53/miR-101/KPNA3 axis.

Abstract P3054: Further Delineation And Exploration Of The Cardiac MicroRNA-Target Interactome

MicroRNAs (miRs) have emerged as key players in cardiac biology and disease. These non-coding RNAs are loaded into Argonaute (Ago) proteins to direct suppression of target mRNAs via base-pairing. Despite a mass of research on cardiac miRs in model systems and humans, the translational impacts have been limited since miR-mRNA target interactions in heart tissues have not been adequately defined at the “-omics” level. Researchers heavily rely on predicted miR targets and are often misled by false predictions, since imperfect base-pairing is sufficient for miR binding. Our goal is to comprehensively define miR targeting events and their biological relevance in the heart and to understand the clinical significance of genetic variants (e.g. SNPs) that modulate cardiac miR functions. We previously used high-throughput biochemical means (Ago2 CLIP-seq) to generate the first transcriptome-wide map of miR binding sites in non-failing human hearts, yielding ~4000 sites across >2000 genes. While exploring this dataset, we discovered translationally relevant miR-SNP interactions that associate with heart failure patient outcomes, most notably in SCN5A . We have since identified multiple common missense variants in TTN that disrupt miR binding. These associate with heart structure/function measures in the general population and could have significant implications for cardiomyopathy patients with TTN mutations. Beyond SNPs, we made the surprising discovery that TTN mRNA harbors >20 miR-133 binding sites and has the potential to bind up to 20% of the miR-133 pool in cardiomyocytes, perhaps serving as an endogenous miR “sponge”. We experimentally validated the potential for this using a TTN mini-gene harboring 18 of the most strongly bound miR-133 target sites; we found that this construct was capable of inhibiting miR-133 activity in cells. Finally, to further expand these studies, we optimized our protocol by adapting state-of-the-art CLIP methods, which recently yielded our 2 nd generation map of human cardiac miR binding sites (now in failing hearts), leading to the identification of >12,000 bindings sites across >6000 genes. We are now interrogating these data and processing additional samples to investigate how miR binding profiles rewire in failing hearts.

The miR-17∼92 miRNAs promote plasma cell differentiation by suppressing SOCS3-mediated NIK degradation

The miR-17∼92 family microRNAs (miRNAs) play a key role in germinal center (GC) reaction through promoting T follicular helper (TFH) cell differentiation. It remains unclear whether they also have intrinsic functions in B cell differentiation and function. Here we show that mice with B cell-specific deletion of the miR-17∼92 family exhibit impaired GC reaction, plasma cell differentiation, and antibody production in response to protein antigen immunization and chronic viral infection. Employing CRISPR-mediated functional screening, we identify Socs3 as a key functional target of miR-17∼92 in regulating plasma cell differentiation. Mechanistically, SOCS3, whose expression is elevated in miR-17∼92 family-deficient B cells, interacts with NIK and promotes its ubiquitination and degradation, thereby impairing NF-κB signaling and plasma cell differentiation. This moderate increase in SOCS3 expression has little effect on IL-21-STAT3 signaling. Our study demonstrates differential sensitivity of two key signaling pathways to alterations in the protein level of an miRNA target gene.

Macrophage-derived exosomes promote intestinal mucosal barrier dysfunction in inflammatory bowel disease by regulating TMIGD1 via mircroRNA-223.

Exosomes are effective mediators of cell-to-cell interactions and transport several regulatory molecules, including microRNAs (miRNAs), involved in diverse fundamental biological processes. The role of macrophage-derived exosomes in the development of inflammatory bowel disease (IBD) has not been previously reported. This study investigated specific miRNAs in macrophage-derived exosomes in IBD and their molecular mechanism. A dextran sulfate sodium (DSS)-induced IBD mouse model was established. The culture supernatant of murine bone marrow-derived macrophages (BMDMs) cultured with or without lipopolysaccharide (LPS) was used for isolating exosomes, which were subjected to miRNA sequencing. Lentiviruses were used to alter miRNA expression and investigate the role of macrophage-derived exosomal miRNAs. Both mouse and human organoids were co-cultured with macrophages in a Transwell system to model cellular IBD in vitro. LPS-induced macrophages released exosomes containing various miRNAs and exacerbated IBD. Based on miRNA sequencing of macrophage-derived exosomes, miR-223 was selected for further analysis. Exosomes with upregulated miR-223 expression contributed to the exacerbation of intestinal barrier dysfunction in vivo, which was further verified using both mouse and human colon organoids. Furthermore, time-dependent analysis of the mRNAs in DSS-induced colitis mouse tissue and miR-223 target gene prediction were performed to select the candidate gene, resulting in the identification of the barrier-related factor Tmigd1. Macrophage-derived exosomal miR-223 has a novel role in the progression of DSS-induced colitis by inducing intestinal barrier dysfunction through the inhibition of TMIGD1.

MiR-21 Targets ASPP2 to Inhibit Apoptosis via CHOP-Mediated Signaling in Helicobacter pylori-Infected Gastric Cancer Cells.

Helicobacter pylori (H. pylori) infection affects cell survival pathways, including apoptosis and proliferation in host cells, and disruption of this balance is the key event in the development of H. pylori-induced gastric cancer (HPGC). H. pylori infection induces alterations in microRNAs expression that may be involved in GC development. Bioinformatic analysis showed that microRNA-21 (miR-21) is significantly upregulated in HPGC. Furthermore, quantitative proteomics and in silico prediction were employed to identify potential targets of miR-21. Following functional enrichment and clustered interaction network analyses, five candidates of miR-21 targets, PDCD4, ASPP2, DAXX, PIK3R1, and MAP3K1, were found across three functional clusters in association with cell death and survival, cellular movement, and cellular growth and proliferation. ASPP2 is inhibited by H. pylori-induced miR-21 overexpression. Moreover, ASPP2 levels are inversely correlated with miR-21 levels in HPGC tumor tissues. Thus, ASPP2 was identified as a miR-21 target in HPGC. Here, we observed that H. pylori-induced ASPP2 suppression enhances resistance to apoptosis in GC cells using apoptosis assays. Using protein interaction network and coimmunoprecipitation assay, we identified CHOP as a direct mediator of the ASPP2 proapoptotic activity in H. pylori-infected GC cells. Mechanistically, ASPP2 suppression promotes p300-mediated CHOP degradation, in turn inhibiting CHOP-mediated transcription of Noxa, Bak, and suppression of Bcl-2 to enact antiapoptosis in the GC cells after H. pylori infection. Clinicopathological analysis revealed correlations between decreased ASPP2 expression and higher HPGC risk and poor prognosis. In summary, the discovery of H. pylori-induced antiapoptosis via miR-21-mediated suppression of ASPP2/CHOP-mediated signaling provides a novel perspective for developing HPGC management and treatment.

Development of an affordable microRNA electrochemical biosensor for identification and monitoring of obstructive sleep apnea and its associated comorbidities

Obstructive sleep apnea (OSA) is a growing and common disorder found in a large global population. Unfortunately, many tend to neglect this disorder without anticipating its chronic and serious health consequences. In this work we demonstrate a prototype portable, low-cost and facile sensing platform that can identify microRNA based molecular markers of OSA including monitoring its severity. An affordable commercial grade gold coated copper cladded laminate sheet was used for fabricating the electrochemical biosensor. The electrode surface was nanotextured to extend a dense and high surface area to significantly improve the sensitivity. A limit of detection of 0.7 nM could be obtained for mir-21 target with a very promising stability of more than 600 days at − 20 °C storage. Clinical utility of the fabricated sensor was established with a rsd of 7.3 % using RNA extracted from PBMC isolated blood samples of various (n = 12) OSA patients and healthy individuals (n = 7). The electrochemical sensing results were compared and satisfactorily validated with ΔCt values obtained from RT-PCR and AHI values from Polysomnography test. Clinical validation not only indicated potentials for an easy portable sensing technology but also a method to monitor patient’s severity of the disorder. These test results have been further supported by statistical analysis that enabled prediction of correlation of OSA with other common lifestyle disorders such as Obesity, liver disorder and diabetes. Overall, the proposed platform holds a strong potential as a reliable alternative to the existing OSA detection technology like Polysomnography that is complex and requires long data acquisition time.

MiR‑122/SENP1 axis confers stemness and chemoresistance to liver cancer through Wnt/β‑catenin signaling.

The property of inherent stemness of tumor cells coupled with the development of chemoresistance results in a poor prognosis for patients with liver cancer. Therefore, the present study focused on microRNA (miR)-122, a potential tumor suppressor, the expression of which has been previously shown to be significantly decreased and negatively associated with cancer cell stemness in liver cancer. The present study aimed to identify the molecular targets of miR-122 whilst uncovering the mechanism underlying chemoresistance and stemness of HepG2 cells in liver cancer. Bioinformatics online tools, such as ENCORI, coupled with dual-luciferase reporter assays in HepG2 cells, were used to identify and validate small ubiquitin-like modifier (SUMO) specific peptidase 1 (SENP1) as a potential target of miR-122 in liver cancer. The liver cancer stem cell population was determined using sphere formation assays and flow cytometry, whilst stem cell markers (Oct3/4, Nanog, B lymphoma Mo-MLV insertion region 1 homolog and Notch1) were detected by reverse transcription-quantitative PCR. Chemoresistance, cell proliferation and migratory ability of HepG2 cells were monitored using Cell Counting Kit-8, colony formation and Transwell assays, respectively. The overexpression of miR-122 by mimic transfection led to a significant decrease in the number spheres, downregulation of stem cell marker expression, the number of CD24+ cells, drug-resistance protein levels (P-glycoprotein and multidrug resistance protein), impaired chemoresistance, proliferation and migration of HepG2 cells. The transfection of SENP1 overexpression vector resulted in contrasting functions to miR-122 mimics, by partially reversing the effects induced by miR-122 mimic transfection in HepG2 cells. Wnt/β-catenin signaling has been proven to be involved in cancer stemness and malignant behavior. Western blotting analysis in HepG2 cells showed that the expression levels of both Wnt1 and β-catenin were significantly reduced after overexpressing miR-122, but increased after overexpressing SENP1. Co-transfection with the SENP1 overexpression vector reversed the suppression induced by the miR-122 mimics on Wnt1 and β-catenin expression. Co-immunoprecipitation, SUMOylation and half-life assays showed SENP1 interacted with β-catenin and decreased the SUMOylation of β-catenin, thereby enhancing its stability. Finally, tumor xenograft analyses revealed that HepG2 cells transfected with Agomir-122 exerted significantly lower tumor initiation frequency and growth rate, and a superior response to DOX in vivo, compared with those transfected with Agomir NC. Taken together, data from the present study miR-122/SENP1 axis can regulate β-catenin stability through de-SUMOylation, thereby promoting stemness and chemoresistance in liver cancer.

MiR-143 targets SYK to regulate NEFA uptake and contribute to thermogenesis in male mice.

Excessive energy intake is the main cause of obesity, and stimulation of brown adipose tissue (BAT) and white adipose tissue (WAT) thermogenesis has emerged as an attractive tool for anti-obesity. Although miR-143 has been reported to be associated with BAT thermogenesis, its role remains unclear. Here, we found that miR-143 was highest expression in adipose tissue, especially in BAT. During short-term cold exposure or CL316,243 injected, miR-143 was markedly down-regulated in BAT and subcutaneous WAT (scWAT). Moreover, knockout of miR-143 (KO) increases the body temperature of mice upon cold exposure, which may be due to the increased thermogenesis of BAT and scWAT. More importantly, supplement of miR-143 in BAT of KO mice can inhibit the increase of body temperature in KO mice. Mechanistically, spleen tyrosine kinase (SYK) was revealed for the first time as a new target of miR-143, and deletion of miR-143 facilitates fatty acid uptake in BAT. In addition, we found that brown adipocytes can promote fat mobilization of white adipocytes, and miR-143 may participate in this process. Meanwhile, we demonstrate that inactivation of AC9 in BAT inhibits thermogenesis through AC9-PKA-AMPK-CREB-UCP1 signaling pathway. Overall, our results reveal a novel function of miR-143 on thermogenesis, and a new functional link of the BAT and WAT.

New oncogenic functions of LINE1 retroelement as a ceRNA for tumor suppressive microRNA miR-126 on ENPP5.

Retroelements (REs) had been considered 'Junk' until the encyclopedia of DNA elements (ENCODE) project demonstrated that most genome is functional. Although the function of retroelements has been reported in diverse cancers including human breast cancer (HBC) and subtypes, only a few studies have suggested the putative functions of REs via their random genome integration. A canine mammary tumor (CMT) has been highlighted due to the similarities in molecular and pathophysiology with HBC. This study investigated the putative roles of REs common in both HBC and CMT. The human LINE and HERV-K sequences harbor many miRNAs responsive elements (MREs) for tumor-suppressive miRNA such as let-7. We also observed that various MREs are exist in the ERV and LINE highly expressed in the transcriptome data of CMT as well as HBC sets. MREs against miR-126 were highly expressed in both HBC and CMT while the levels of miR-126 were down-regulated. Oppositely, the expression of miR-126 target genes was significantly up-regulated in the cancers. Moreover, cancer patients with an increased level of miR-126 showed better overall survival. The expression of ENPP5, a putative miR-126 target gene, was downregulated by miR-126 mimic. Importantly, overexpression of LINE fragment significantly suppressed miR-126 function on the target gene expression. We propose the functional role of REs expression in tumorigenesis as competing endogenous RNAs (ceRNA) against tumor-suppressive miRNAs. This study provided pieces of evidence that LINE expression, even partial and fragmented, have a regulatory function in ENPP5 gene expression via the competition with miR-126.

P-155 MicroRNA-155 (miR-155) expression profile and developmental characteristics of bovine early embryos are altered when cultured in group versus individually

Abstract Study question Culturing bovine preimplantation embryos in group versus individually has an impact on the expression profile of miR-155 and developmental characteristics. Summary answer MiR-155 was significantly greater in its expression when embryos were cultured in groups versus singly. Developmental characteristics of blastocysts were similar regardless of culture condition. What is known already MiRNAs are short non-coding RNAs that play important roles in many biological pathways including embryogenesis and are potent effectors of post-transcriptional gene silencing. It has been estimated that approximately 60% of all proteins-coding genes are regulated by miRNAs. MiR-155 is involved in early events of embryogenesis; however, it has not been characterized in bovine embryos and this knowledge has not yet been clinically translated. Existing literature indicates that group culture yields superior embryo development as embryos can benefit from autocrine signaling and paracrine communication but embryos in groups may be exposed to negative effects of dying or delayed embryos. Study design, size, duration The study consisted of two groups: zygotes cultured to blastocysts in group and those cultured individually. Each sample consists of 3 blastocysts. Droplet digital PCR (dd-PCR) was used to examine the expression of miR-155. Gene Set Enrichment Analysis (GSEA) of miRNAs was carried out to identify functional Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways that are enriched for the targets of one or more miRNAs. Participants/materials, setting, methods Oocytes were aspirated from antral follicles of bovine ovaries and matured in vitro. Twenty-four hours post retrieval, matured oocytes were inseminated with sperm from similar bull. Presumptive zygotes were cultured either in groups or individually until blastocyst stage, Blastocyst were collected and purified for RNA. Analysis for KEGG and GO Biological Process, Cellular Component and Molecular Functions were carried out on the identified target genes. Results were plotted according to level of enrichment for miR-155. Main results and the role of chance Five hundred and seventy-five oocytes were retrieved from 120 bovine ovaries. Cleavage rate and blastocyst formation after IVF were compared between those blastocysts cultured in groups versus individually. There was no significant difference among the two groups with regards to cleavage rate (69% vs. 54%) and blastocyst formation (42% vs.35%). ddPCR assessment showed significantly greater MiR-155 expression in those blastocysts cultured in groups (p = 0.002). The highest level of miR-151 expressed was 20 copies/sample. Every sample, regardless of the culture conditions, had detectable miR-155 level. The interaction of predicted miR-155 target clusters based on the GO Biological Processes shows that miR-155 plays a role in DNA binding, transcription factor binding, regulates transcription and affects cell adhesion. KEGG analysis revealed an association between miR-155 to steroidogenesis and controls apoptosis pathways. Limitations, reasons for caution The number of copies expressed for this miRNA was relatively low, which could suggest that miR-155 may not have a functional role at the blastocyst stage as the effectiveness of a miRNA depends on the relative number of binding site and target molecules. Blastocysts were pooled based on morphological assessment. Wider implications of the findings MiRNAs offer a novel mean to assess embryonic fitness. Further validation and more complex study designs are required to implement the profiling of embryonic miRNAs as a diagnostic test for embryo selection. Group culture increased miR-155 expression, possibly reflecting differences in cellular behavior between group cultured embryos and individually ones. Trial registration number Not applicable

Identifying miRNA biomarkers for breast cancer and ovarian cancer: a text mining perspective.

microRNA (miRNAs) are small, non-coding RNAs that mediate post-transcriptional gene silencing. Numerous studies have demonstrated the critical role of miRNAs in the development of breast cancer and ovarian cancer. To reduce potential bias from individual studies, a more comprehensive approach of exploring miRNAs in cancer research is essential. This study aims to explore the role of miRNAs in the development of breast cancer and ovarian cancer. Abstracts of the publications were tokenized and the biomedical terms (miRNA, gene, disease, species) were identified and extracted for vectorization. Predictive analyses were conducted with four machine learning models: K-Nearest Neighbors (KNN), Support Vector Machines (SVM), Random Forest (RF), and Naïve Bayes. Both holdout validation and cross-validation were utilized. Feature importance will be identified for miRNA-cancer networks construction. We found that miR-182 is highly specific to female cancers. miR-182 targets different genes in regulating breast cancer and ovarian cancer. Naïve Bayesprovided a promising prediction model for breast cancer and ovarian cancer with miRNAs and genes combination, with an accuracy score greater than 60%. Feature importance identified miR-155 and miR-199 are critical for breast cancer and ovarian cancer prediction, with miR-155 being highly related to breast cancer, whereas miR-199 being more associated with ovarian cancer. Our approach effectively identified potential miRNA biomarkers associated with breast cancer and ovarian cancer, providing a solid foundation for generating novel research hypotheses and guiding future experimental studies.

CircRNA-02191 regulating unsaturated fatty acid synthesis by adsorbing miR-145 to enhance CD36 expression in bovine mammary gland

CD36 functions as a receptor for long-chain fatty acids, promoting the absorption and transport of long-chain unsaturated fatty acids. However, the regulatory influence of upstream circRNAs or miRNAs on its expression in cow mammary gland remains unclear. Herein, we performed high-throughput sequencing to screen for differentially expressed miRNAs and mRNAs in bovine mammary tissue during the late-lactation and the dry period to screen and conducted bioinformatics analysis to identify 420 miRNA/mRNA pairs, including miR-145/CD36. Experimental results indicate that miR-145 can directly target CD36 and inhibit its expression. Additionally, the circRNA-02191 sequence is predicted to contain a miR-145 binding site. As shown by dual luciferase reporter system detection, circRNA-02191 bound to miR-145 and its overexpression significantly reduced the expression of miR-145. Furthermore, the overexpression of miR-145 inhibited triglyceride accumulation, while circRNA-02191 enhanced the expression of the miR-145 target gene CD36. The above results indicate that circRNA-02191 can regulate triglyceride and fatty acid components by binding miR-145 and subsequently alleviating the inhibitory effect of miR-145 on the expression of CD36. Taken together, these findings present a novel approach to improve milk quality by analyzing the regulatory effect and mechanism regulating the circ02191/miR-145/CD36 pathway on fatty acid synthesis in the mammary gland of dairy cows.

MiR-140 and miR-200 regulate the migratory heterogeneity of location-specific Schwann cell population.

Schwann cells are functional cells in nerve regeneration and are commonly used as seed cells in tissue engineering. Enhanced Schwann cell migration capacity improves recovery effects, and thus, the identification of Schwann cells with greater migration ability is of great importance. In the present study, we examined the biological activities of Schwann cells collected from rat sciatic nerves (SN) and dorsal root ganglia (DRG). Observations from transwell migration assay and wound healing assay demonstrate that DRG Schwann cells migrate at a faster speed as compared with SN Schwann cells. Sequencing and bioinformatics suggest that differentially expressed genes between SN and DRG Schwann cells are associated with cell motility and migration. miR-140 and miR-200, two microRNAs (miRNAs) that are highly expressed in SN Schwann cells negatively influence Schwann cell migration and thus may be key regulators of Schwann cell phenotype. Igsf10, Plxna2, and Lcp1 are screened as candidate downstream targets of miR-140 and miR-200 based on bioinformatic analysis and their expression correlation with miRNAs. Our comparative analysis displays the unique characteristics of Schwann cells in different anatomical localizations and demonstrates that DRG Schwann cells are suitable seed cells for tissue engineering and regenerative medicine.

MiR-9 targeting RUNX1 improves LPS-induced alveolar hypercoagulation and fibrinolysis inhibition through NF-κB inactivation in ARDS

BackgroundAcute respiratory distress syndrome (ARDS) is a clinical and pathophysiological complex syndrome with high mortality. Alveolar hypercoagulation and fibrinolytic inhibition constitute the core part of the pathophysiology of ARDS. miR-9 (microRNA-9a-5p) plays an important role in the pathogenesis of ARDS, but whether it regulates alveolar pro-coagulation and fibrinolysis inhibition in ARDS remains to be elucidated. We aimed to determine the contributing role of miR-9 on alveolar hypercoagulation and fibrinolysis inhibition in ARDS. MethodsIn the ARDS animal model, we first observed the miR-9 and runt-related transcription factor 1 (RUNX1) expression in lung tissue, the effects of miR-9 on alveolar hypercoagulation and fibrinolytic inhibition in ARDS rats, and the efficacy of miR-9 on acute lung injury. In the cell, alveolar epithelial cells type II (AECII) were treated with LPS, and the levels of miR-9 and RUNX1 were detected. Then we observed the effects of miR-9 on procoagulant and fibrinolysis inhibitor factors in cells. Finally, we explored whether the efficacies of miR-9 were associated with RUNX1; we also preliminarily examined the miR-9 and RUNX1 levels in plasma in patients with ARDS. ResultsIn ARDS rats, miR-9 expression decreased, but RUNX1 expression increased in the pulmonary tissue of ARDS rats. miR-9 displayed to attenuate lung injury and pulmonary wet/dry ratio. Study results in vivo demonstrated that miR-9 ameliorated alveolar hypercoagulation and fibrinolysis inhibition and attenuated the collagen III expressions in tissue. miR-9 also inhibited NF-κB signaling pathway activation in ARDS. In LPS-induced AECII, the expression changes of both miR-9 and RUNX1 were similar to those in pulmonary tissue in the animal ARDS model. miR-9 effectively inhabited tissue factor (TF), plasma activator inhibitor (PAI-1) expressions, and NF-κB activation in LPS-treated ACEII cells. Besides, miR-9 directly targeted RUNX1, inhibiting TF and PAI-1 expression and attenuating NF-κB activation in LPS-treated AECII cells. Clinically, we preliminarily found that the expression of miR-9 was significantly reduced in ARDS patients compared to non-ARDS patients. ConclusionOur experimental data indicate that by directly targeting RUNX1, miR-9 improves alveolar hypercoagulation and fibrinolysis inhibition via suppressing NF-κB pathway activation in LPS-induced rat ARDS, implying that miR-9/RUNX1 is expected to be a new therapeutic target for ARDS treatment.

MiR-145 Modulates Fatty Acid Metabolism by Targeting FOXO1 to Affect SERBP1 Activity in Bovine Mammary Epithelial Cells

MicroRNA-mediated gene regulation is important for the regulation of fatty acid metabolism and synthesis. Our previous study uncovered that the miR-145 expression is higher in the lactating mammary gland of dairy cows than in the dry-period, but the underlying molecular mechanism is incompletely understood. In this study, we have investigated the potential role of miR-145 in bovine mammary epithelial cells (BMECs). We found that the expression of miR-145 gradually increased during lactation. CRISPR/Cas9-mediated knockout (KO) of miR-145 in BMECs results in the downregulated expression of fatty acid metabolism-associated genes. Further results revealed that miR-145 KO reduced total triacylglycerol (TAG) and cholesterol (TC) accumulation and altered the composition of intracellular fatty acids (C16:0, C18:0, and C18:1). Conversely, miR-145 overexpression had the opposite effect. Bioinformatics online program predicted that miR-145 targets the 3'-UTR of the Forkhead Box O1 (FOXO1) gene. Subsequently, FOXO1 was identified as a direct target of miR-145 by qRT-PCR, Western blot analysis, and luciferase reporter assay. Furthermore, siRNA-mediated silencing of FOXO1 promoted fatty acid metabolism and TAG synthesis in BMECs. Additionally, we observed the involvement of FOXO1 in the transcriptional activity of the sterol regulatory element-binding protein 1 (SREBP1) gene promoter. Overall, our findings indicated that miR-145 relieves the inhibitory effect of FOXO1 on SREBP1 expression by targeting FOXO1 and subsequently regulating fatty acid metabolism. Thus, our results provide valuable information on the molecular mechanisms for improving milk yield and quality from the perspective of miRNA-mRNA networks.

Loss of microRNA-29 in B cells leads to atopic skin phenotype in mice

Abstract Developing B cells are highly dependent on microRNA (miRNA) regulation. We have previously demonstrated the miR-29 family of miRNAs contributes to the regulation of B cell survival through fine-tuning of PTEN expression, a negative regulator of B cell receptor (BCR) signaling. When the miR-29 alleles are selectively deleted in B cells, this leads to reduced survival which can be rescued by ablating one copy of Ptento restore normal BCR signaling. We observed that mice with B cells lacking miR-29 also develop an inflammatory skin phenotype associated with lesions, leukocyte infiltration into the skin, and persistent pruritis. Nearly 50% of miR-29-deficient animals die within 6 months of birth, and ablation of Ptento restore BCR signaling did not improve the survival rate. This suggests that additional targets of miR-29 in B lymphocytes are involved in promoting this inflammatory skin condition. Epidermal thickening, granulocyte plasma cell infiltration in the skin, and high serum IgE titers suggest that miR-29 may contribute to the regulation of IgE-driven immune responses and that in the absence of this miRNA family, animals develop atopic dermatitis. Our bioinformatic analysis revealed that miR29 is predicted to regulate the expression of the Il4Ratranscript, and in vitrodifferentiation assays revealed that miR-29-deficient B cells have a higher propensity for IgE class switch recombination in response to IL-4 and/or IL-13 stimulation compared to wild-type control B cells. We conclude that miR-29 is critical in the regulation of both Ptenand Il4raexpression in mature B cells thereby influencing the survival and function of peripheral B lymphocytes, which can have profound repercussions for the development of autoimmune disease. The Bernard Levine Fellowship

Extracellular vesicles derived from cervical cancer cells carrying MCM3AP-AS1 promote angiogenesis and tumor growth in cervical cancer via the miR-93/p21 axis

Tumor cells can promote angiogenesis by secreting extracellular vesicles (EVs). Meanwhile, tumor-derived EVs can carry long non-coding RNAs to activate pro-angiogenic signaling in endothelial cells. Here, we investigated the role of long non-coding RNA MCM3AP-AS1 carried by cervical cancer (CC) cell-derived EVs in the angiogenesis and the resultant tumor growth in CC, as well as the potential molecular mechanisms. LncRNAs significantly expressed in CC cell-derived EVs and CC were screened, followed by prediction of downstream target genes. EVs were isolated from HcerEpic and CaSki cell supernatants, followed by identification. The expression of MCM3AP-AS1 in CC was analyzed and its interaction with miR-93-p21 was confirmed. Following co-culture system, the role of MCM3AP-AS1 carried by EVs in HUVEC angiogenic ability, CC cell invasion and migration in vitro along with angiogenesis and tumorigenicity in vivo was assayed. MCM3AP-AS1 was overexpressed in CC cell-derived EVs as well as in CC tissues and cell lines. Cervical cancer cell-derived EVs could transfer MCM3AP-AS1 into HUVECs where MCM3AP-AS1 competitively bound to miR-93 and upregulate the expression of the miR-93 target p21 gene. Thus, MCM3AP-AS1 promoted angiogenesis of HUVECs. In the similar manner, MCM3AP-AS1 enhanced CC cell malignant properties. In nude mice, EVs-MCM3AP-AS1 induced angiogenesis and tumor growth. Overall, this study reveals that CC cell-derived EVs may transport MCM3AP-AS1 to promote angiogenesis and tumor growth in CC.

The microRNA cluster miR-17~92 is induced by aldosterone and estrogen and inhibits aldosterone signaling in the kidney distal nephron

Background: Hypertension affects more than one billion people worldwide. A key regulator of blood pressure homeostasis is aldosterone, the final signaling hormone of the renin-angiotensin-aldosterone-signaling (RAAS) system. Aldosterone increases sodium (Na+) transport in the kidney distal nephron to regulate blood volume. We previously demonstrated that aldosterone alters the expression of microRNAs (miRs) in collecting duct epithelial cells to modulate the Na+ transport response to aldosterone. In this study a novel miR cluster, miR-17~92, is investigated for its ability to alter aldosterone signaling in the kidney in a sex-specific manner. Methods: The cortical collecting duct (CCD), mCCD-cl1, cell line were cultured on permeable filter supports to measure Na+ transport by short-circuit current recordings in Ussing chambers. In vivo regulation of miRs by aldosterone was confirmed using freshly isolated CCD cells from male and female mice placed on low Na+ diets. Dual-luciferase assays validated miR targeting of the serum and glucocorticoid kinase (SGK1). CCD cells were treated with estrogen to determine the impact on aldosterone stimulation and Na+ transport. RT-qPCR quantified miR and mRNA expression and western blot analysis quantified protein expression of the RAAS signaling cascade in mCCD cells after aldosterone and estrogen stimulation. Results: The miR-17~92 cluster expression is increased after aldosterone and estrogen stimulation in cultured mCCD cells. A sex-specific upregulation of the miR-17~92 cluster was observed in isolated CCD cells from female mice placed on a low-Na+ diet to stimulate aldosterone release. This increase was not observed in male mice. Members of the miR cluster, miRs-19a&b, are predicted to bind to the 3’-untranslated region of SGK1 and this was confirmed using luciferase assays. Overexpression of miR-19 in mCCD cells using miR mimics significantly inhibited aldosterone stimulation of Na+ transport via the epithelial sodium channel (ENaC). Estrogen pretreatment of mCCD blunted a subsequent aldosterone stimulation. This blunting of aldosterone signaling was due to a decrease in SGK1 mRNA and protein levels, for both estrogen stimulated and miR-19 mimic overexpressing cells. Conclusion: The miR-17~92 cluster is regulated by aldosterone and estrogen. Mir-19 targets SGK1 and reduces its expression. This, in turn, reduces the aldosterone-induced ENaC transport. The regulation of miR-17~92 is sex-specific and estrogen responsive, and targets SGK1 to downregulate sodium transport in the CCD. This could contribute to sex differences in sodium homeostasis. NIH 5T32DK061296-20 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The miR-7/EGFR axis controls the epithelial cell immunomodulation and regeneration and orchestrates the pathology in inflammatory bowel disease

IntroductionThe epithelial immunomodulation and regeneration are intrinsic critical events against inflammatory bowel disease (IBD). MiR-7 is well documented as a promising regulator in the development of various diseases including inflammatory diseases. ObjectivesThis study aimed to assess the effect of miR-7 in intestinal epithelial cells (IECs) in IBD. MethodsMiR-7def mice were given dextran sulfate sodium (DSS) to induce enteritis model. The infiltration of inflammatory cells was measured by FCM and immunofluorescence assay. 5′deletion assay and EMSA assays were performed to study the regulatory mechanism of miR-7 expression in IECs. The inflammatory signals and the targets of miR-7 were analyzed by RNA-seq and FISH assay. IECs were isolated from miR-7def, miR-7oe and WT mice to identify the immunomodulation and regeneration capacity. IEC-specific miR-7 silencing expression vector was designed and administered by the tail vein into murine DSS-induced enteritis model to evaluate the pathological lesions of IBD. ResultsWe found miR-7 deficiency improved the pathological lesions of DSS-induced murine enteritis model, accompanied by elevated proliferation and enhanced transduction of NF-κB/AKT/ERK signals in colonic IECs, as well as decreased local infiltration of inflammatory cells. MiR-7 was dominantly upregulated in colonic IECs in colitis. Moreover, the transcription of pre-miR-7a-1, orchestrated by transcription factor C/EBPα, was a main resource of mature miR-7 in IECs. As for the mechanism, EGFR, a miR-7 target gene, was downregulated in colonic IECs in colitis model and Crohn's disease patients. Furthermore, miR-7 also controlled the proliferation and inflammatory-cytokine secretion of IECs in response to inflammatory-signals through EGFR/NF-κB/AKT/ERK pathway. Finally, IEC-specific miR-7 silencing promoted the proliferation and transduction of NF-κB pathway in IECs and alleviated the pathological damage of colitis. ConclusionOur results present the unknown role of miR-7/EGFR axis in IEC immunomodulation and regeneration in IBD and might provide clues for the application of miRNA-based therapeutic strategies in colonic diseases.