Target Gene Of miR-21 Research Articles

LIPUS promotes FOXO1 accumulation by downregulating miR-182 to enhance osteogenic differentiation in hPDLCs

Low intensity pulsed ultrasound (LIPUS) promotes bone fracture healing in clinical therapy. Transcription factor Forkhead box O1 (FOXO1) is crucial for bone differentiation. But whether FOXO1 is involved in LIPUS-promoted bone differentiation is largely unknown. In the current study, treatment of human primary periodontal ligament cells (hPDLCs) with LIPUS promoted total and nucleus FOXO1 protein accumulation. LIPUS-induced activation of FOXO1 further lead to higher alkaline phosphatase (ALP) and runt-related transcription factor 2 (Runx2) expression and matrix mineralization. LIPUS inhibited miR-182 expression, which functioned as a repressor of FOXO1 through post-transcriptional regulation. Overexpression of miR-182 reversed the LIPUS-enhanced FOXO1 expression and osteogenic differentiation. Moreover, LIPUS enhanced Akt phosphorylation, which functioned in preventing active FOXO1 excessive accumulation via inducing the cytoplasm translocation of nucleus FOXO1. In conclusion, our study revealed that FOXO1, which was a target gene of miR-182, played an essential role in LIPUS-promoted osteogenic differentiation. This new molecular insight throws light upon the application of LIPUS therapy on periodontal bone defect.

IL6R inhibits viability and apoptosis of pancreatic beta-cells in type 2 diabetes mellitus via regulation by miR-22 of the JAK/STAT signaling pathway.

Background and aimType 2 diabetes mellitus (T2DM) is a common disease of harming to people’s health. MicroRNAs have recently been considered as key regulators of many biological processes, such as cell proliferation, migration and apoptosis. However, the effect of miR-22 expression by targeting IL6 receptor (IL6R) in T2DM and potential molecular mechanism involved remains to be elucidated. The present study aimed to explore the regulatory mechanism of miR-22 by targeting IL6R in pancreatic beta-cells viability and apoptosis of T2DM.MethodsThe expressions of miR-22, IL6R and apolipoprotein (apoA1, apoB and apoE) were examined by reverse transcription-quantitative PCR (qRT-PCR). Pancreatic beta-cells were transiently transfected with a miR-22 mimic or si-IL6R plasmid which validated with qRT-PCR to analyze the expression of miR-22 or IL6R. Cell viability, apoptosis and protein expression levels were determined by CCK-8, flow cytometry and Western blotting, respectively.ResultsThe proportion of INS-1E cell apoptosis was increased in islets of diabetic rats. Furthermore, miR-22 was downregulated and IL6R was upregulated in both diabetic serum and glucose-induced INS-1E cells. miR-22 overexpression or IL6R inhibition significantly strengthened cell viability and reduced the expression of apoptosis-related proteins to suppress cell apoptosis. IL6R was demonstrated as a target gene of miR-22 which could negatively regulate IL6R expression. Moreover, phosphorylation of JAK/STAT signaling pathway was activated by miR-22 overexpression or IL6R inhibition to strengthen the viability and suppress apoptosis of INS-1E cells.ConclusionThis study indicated that miR-22 strengthened the viability and suppressed apoptosis of INS-1E cells, partly by down-regulation of IL6R through the activation of JAK/STAT signaling pathway.

An integrative bioinformatics analysis identified miR-375 as a candidate key regulator of malignant breast cancer.

MicroRNAs (miRNAs) are key regulators that play important biological roles in carcinogenesis and are promising biomarkers for cancer diagnosis and therapy. hsa-miR-375-3p (miR-375) has been suggested to serve as a tumor suppressor or oncogene in various tumor types; however, its specific expression and potential regulatory role in malignant breast cancer remain unclear. In this study, the results from noncoding RNA microarray analysis indicated that the miR-375 expression level is significantly decreased in malignant basal-like breast cancer compared with luminal-like breast cancer. A total of 1895 co-downregulated and 1645 co-upregulated genes were identified in miR-375 mimic-transfected basal-like breast cancer cell lines. Predicted miR-375 targets were obtained from the online databases TargetScan and DIANA-microT-CDS. Combined KEGG enrichment analysis for coregulated genes and predicted miR-375 targets provided information and revealed differences in potential dynamic signaling pathways regulated by miR-375 and also indicated specific regulatory pathways, such as RNA transport and processing, in basal-like breast cancer. Additionally, gene expression microarray analysis accompanied by UALCAN analysis was performed to screen upregulated genes in the basal-like subtype. Four potential key genes, including LDHB, CPNE8, QKI, and EIF5A2, were identified as candidate target genes of miR-375. Therefore, the present study demonstrated that miR-375 may be a potential key regulator and provide a promising direction for diagnostic and therapeutic developments for malignant breast cancer.

MiR-126 promotes endothelial cell apoptosis by targeting PI3K/Akt in rats with lower limb arteriosclerosis obliterans.

To investigate the influence of micro ribonucleic acid (miR)-126 on the rats with lower limb arteriosclerosis obliterans (ASO). Male Sprague- Dawley rats aged 3 months old were randomly divided into Sham operation group (Control group, n=10) and Model group (n=10), and the model of lower limb ASO was established. After modeling, the expression of miR-126 in arteries was detected using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR), and the change in the downstream signaling pathway was examined via Western blotting. The human umbilical vein endothelial cells (HUVECs) were induced by oxidized low-density lipoprotein (Ox-LDL) to establish the model of endothelial injury, followed by detection of miR-126 expression. Then, the Luciferase assay was performed to verify the downstream target gene of miR-126. After being cultured, HUVECs were set as Control group, Ox-LDL induction group, and Ox-LDL + miR-126 inhibitor group, and the expressions of phosphorylated-protein kinase B (p-Akt) and cleaved cysteine-aspartic protease-3 (Caspase-3) were detected in the above groups. After the establishment of the model, the expression level of miR-126 was raised in vessels, but the phosphatidylinositol 3-hydroxy kinase (PI3K)/Akt signals were weakened (p<0.01). Ox-LDL-induced endothelial cell apoptosis promoted the expression of miR-126, and the difference was statistically significant. The bioinformatics analysis results showed that PI3KR2 was a direct target of miR-126, which was also proven via the Luciferase assay. Moreover, the transfection with miR-126 inhibitor into endothelial cells suppressed Ox-LDL-induced cell apoptosis, thereby persistently activating the PI3K/Akt signaling pathway (p<0.01). In rats with lower limb arteriosclerosis obliterans (ASO), miR-126 represses the PI3K/Akt signaling pathway to accelerate endothelial cell apoptosis.

MicroRNA-21 promotes breast cancer proliferation and metastasis by targeting LZTFL1

BackgroundBreast cancer is the most common cancer type in female. As microRNAs play vital role in breast cancer, this study aimed to explore the molecular mechanism and clinical value of miR-21 in breast cancer.MethodsqRT-PCR was performed to detect miR-21 levels in plasma of 127 healthy controls, 82 benign breast tumor, 252 breast cancer patients, as well as in breast cancer cell lines. Transwell and wound healing assay were used to analyze breast cancer metastasis in response to miR-21 inhibitor. Colony formation and eFluor™ 670 based flow cytometric analysis were used to test breast cancer proliferation following miR-21 inhibitor treatment. Leucine zipper transcription factor-like 1 (LZTFL1), the target gene of miR-21 was predicted by MIRDB, TargetScan 5.1, PicTar and miRanda. Survival analysis of LZTFL1 levels in breast cancer prognosis was estimated with the Kaplan–Meier method by log-rank test according to data from the Cancer Genome Atlas. Luciferase activity assay was performed to confirm the regulation of miR-21 on LZTFL1. LZTFL1 siRNA and miR-21 inhibitor were co-transfected to breast cancer cells, then cell proliferation, migration and epithelial–mesenchymal transition (EMT) makers were tested. BALB/c nude mice were injected in situ with Hs578T cells stably overexpressing miR-21. Breast tumor growth, metastasis and the expression of EMT markers or LZTFL1 were detected in vivo.ResultsPlasma miR-21 levels were elevated in breast cancer patients compared with healthy controls and benign breast tumor patients, and the miR-21 levels were significantly decreased after surgery comparing with pre operation in 44 patients. Inhibition of miR-21 suppressed cell proliferation and metastasis in breast cancer cells. LZTFL1 was identified as a novel target gene of miR-21. Knockdown of LZTFL1 overcame the suppression of miR-21 inhibitor on cell proliferation, metastasis and the expression of EMT markers in breast cancer cells. miR-21 overexpression promoted breast cancer cell proliferation and metastasis in vivo.ConclusionsThese results indicate that plasma miR-21 level is a crucial biomarker for breast cancer diagnosis and targeting miR-21–LZTFL1–EMT axis might be a promising strategy in breast cancer therapy.Trial registrationRetrospectively registered.

Up-regulation of microRNA-203 inhibits myocardial fibrosis and oxidative stress in mice with diabetic cardiomyopathy through the inhibition of PI3K/Akt signaling pathway via PIK3CA

Diabetic cardiomyopathy (DCM) refers to the myocardial dysfunction in the absence of coronary artery disease and hypertension. Recently, the role of microRNAs (miRs) in gene expression regulation has attracted much more attention. Studies have shown that the PI3K/Akt signaling pathway is involved in the growth, metabolism and apoptosis of myocardial cells. Therefore, this study aimed to explore the regulatory role of miR-203 in myocardial fibrosis in mice with DCM via involvement of the PI3K/Akt signaling pathway. Firstly, mouse model of diabetes mellitus (DM) was established and injected with agomir, antagomir or IGF-1 (PI3K/Akt signaling pathway activator) for investigating the role of miR-203 in PIK3CA and the PI3K/Akt signaling pathway. PIK3CA was identified as a target gene of miR-203, and overexpressed miR-203 inhibited the activation of PI3K/Akt signaling pathway. The obtained results indicated that up-regulation of miR-203 reduced myocardial hypertrophy, myocardial fibrosis, myocardial apoptosis, and levels of PIK3CA, PI3K, Akt, CoI I, CoI III, ANP, MDA and ROS in the myocardial tissues, by which DM-induced cardiac dysfunction and pathological changes could be ameliorated. Collectively, our present study highlighted that overexpression of miR-203 may function as a cardioprotective regulator in DCM by targeting PIK3CA via inactivation of PI3K/Akt signaling pathway.

Down-regulation of microRNA-138 improves immunologic function via negatively targeting p53 by regulating liver macrophage in mice with acute liver failure.

MicroRNAs (miRNAs) have been frequently identified as key mediators in almost all developmental and pathological processes, including those in the liver. The present study was conducted with aims of investigating the role of microRNA-138 (miR-138) in acute liver failure (ALF) via a mechanism involving p53 and liver macrophage in a mouse model. The ALF mouse model was established using C57BL/6 male mice via tail vein injection of Concanamycin A (Con A) solution. The relationship between miR-138 and p53 was tested. The mononuclear macrophages were infected with mimic and inhibitor of miR-138 in order to identify roles of miR-138 in p53 and levels of inflammatory factors. Reverse transcription quantitative polymerase chain reaction (RT-qPCR), Western blot analysis and ELISA were conducted in order to determine the levels of miR-138, inflammatory factors, and p53 during ALF. The results showed an increase in the levels of miR-138 and inflammatory factors in ALF mice induced by the ConA as time progressed and reached the peak at 12 h following treatment with ConA, while it was on the contrary when it came to the level of p53. Dual-luciferase reporter gene assay revealed that p53 was a target gene of miR-138. Furthermore, the results from the in vitro transfection experiments in primary macrophages of ALF mouse showed that miR-138 down-regulated p53 and enhanced levels of inflammatory factors; thus, improving immune function in ALF mice. In conclusion, by negatively targeting p53, the decreased miR-138 improves immunologic function by regulating liver macrophage in mouse models of ALF.

MicroRNA-155 inhibition up-regulates LEPR to inhibit osteoclast activation and bone resorption via activation of AMPK in alendronate-treated osteoporotic mice.

Osteoporosis is characterized by a progressive increase in bone fragility, leading to low bone mass and structural deterioration of bone tissue. MicroRNA-155 (miR-155) is highly expressed in osteoporosis. Thus, the current study aimed to investigate the effect of miR-155 on the inhibition of osteoclast activation and bone resorption by targeting leptin receptor (LEPR) through the adenosine monophosphate activated protein kinase (AMPK) pathway in alendronate-treated osteoporotic mice. An osteoporosis mouse model was established to examine the bone tension and bone density and the expression of miR-155 in osteoclasts. Binding sites between miR-155 and LEPR were verified. Osteoclasts in the treatment group were transfected with different mimic, inhibitor, vector, or siRNA for subsequent experiments. The expression of miR-155, LEPR, AMPK, p-AMPK, RANKL, OPG, M-CSF, RANK, TRAP, Bax, Bcl-2, and the contents of TNF-α and IL-1β were all examined. The proliferation and bone resorption of osteoclasts were also detected. Mice with osteoporosis exhibited decreased bone density and bone tension, along with elevated expression of miR-155. LEPR was verified as a target gene of miR-155. Down-regulated miR-155 was found to increase the expression of LEPR, AMPK, p-AMPK, OPG, Bax, decrease expression of TNF-α, IL-1β, RANKL, M-CSF, RANK, TRAP, Bcl-2, inhibit the cell proliferation and bone resorption of osteoclasts. Taken together, decreased miR-155 up-regulated LEPR via activation of AMPK, which ultimately repressed osteoclast activation and bone resorption of osteoclasts in alendronate-treated osteoporotic mice.

MiR-203 inhibits the malignant behavior of prostate cancer cells by targeting RGS17.

The aim of this study was to explore the role of microRNA-203 (miR-203) in Prostate Cancer (PCa), and to further verify its influence in PCa cell function. The expression level of miR-203 in 55 clinical PCa cases and cell lines was detected by qRT-PCR. Then, the target gene of miR-203 in PCa cells was predicted and verified by online prediction software and Luciferase reporter gene assay, respectively. Furthermore, the role of miR-203 in PCa cell proliferation, colony formation, cell cycle and metastasis capacities was detected through a series of in vitro experiments. The expression of miR-203 in PCa tissues and cells was significantly reduced when compared with that of normal tissues and cells. In searching for potential downstream targets of miR-203, a regulator of G-protein signaling 17 (RGS17) entered our sight due to its active role in a variety of malignant tumors. More importantly, the negative regulation of RGS17 by miR-203 was verified by Luciferase reporter gene assay. Functional experiments demonstrated that low expression of RGS17 in PCa cells induced by up-regulation of miR-203 could significantly restrain the proliferation, invasion and migration capacities of PCa cells. MiR-203 served as a tumor suppressor gene in PCa. Through targeting RGS17, miR-203 significantly controlled the malignant behavior of PCa cells. Our findings revealed that miR-203/RGS17 axis might be a potential therapeutic target for the treatment of PCa.

Abstract 783: miR-375 downregulates VEGFA via YAP1-EBRR2 pathway in esophageal cancer

Abstract Esophageal cancer (EC), including esophageal squamous cell carcinoma (ESCC) and adenocarcinoma (EAC), is one of the deadliest cancers with extremely aggressive nature and poor survival rate. Diagnostic methods for EC mainly include endoscopy, barium swallow and ultrasound, which are either invasive or lack of sensitivity and specificity at early stages. Therefore, the development of a non-invasive and reliable diagnostic method with high sensitivity and specificity is crucial in improving early detection, diagnosis and treatment. microRNAs (miRNAs) are small RNA molecules that regulate the expression of protein-coding genes by directly binding to target mRNAs in a sequence-specific manner. The aim of this study is to identify novel miRNA biomarkers for EC diagnosis. By cross-referencing our data with others’ from NCBI, we identified a list of dysregulated miRNAs in EC, including miR-375. We assessed the expression of miR-375 in EC cell lines and tissues using real-time reverse transcriptase-polymerase chain reaction (qRT-PCR). We found that miR-375 expression is significantly decreased in human EC cell lines (KEYS-70, KEYS-180, FLO-1 and JHU-ad1) compared to the normal esophageal squamous cell line, Het-1A. Using microdissection technique, we isolated normal epithelium, dysplasia, and invasive EC components from formalin-fixed, paraffin-embedded (FFPE) tissue followed by qRT-PCR analysis. Decreased expression of miR-375 was detected in 12 of 14 EC tissue samples (86%) compared to the matched normal tissues. MTT and Matrigel invasion assay demonstrated that forced expression of miR-375 suppressed the proliferation and invasion in EC cell lines. TargetScanS and miRanda were used to identify potential target genes of miR-375, which includes epidermal growth factor receptor 2 (HER2) and YES-associated protein (YAP1), both of them act as oncogenes in EC development. Interestingly, forced expression of miR-375 resulted in significantly reduced expression of human vascular endothelial growth factor-A (VEGF-A) gene, which is a downstream target gene of YAP1/ERBB2 pathway involving in tumor angiogenesis in EC cell lines. More functional analysis is under way. These findings suggest that miR-375 may act as a tumor suppressor, and could serve as a marker for EC diagnosis and management. Citation Format: Shuchang Ren, Xiaohui Tan, Xiaoling Wu, Tao Chen, Patricia Latham, Sidney W. Fu. miR-375 downregulates VEGFA via YAP1-EBRR2 pathway in esophageal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 783.

Upregulation of miR-675-5p induced by lncRNA H19 was associated with tumor progression and development by targeting tumor suppressor p53 in non-small cell lung cancer.

Lung cancer is the main cause of cancer-related death, and the proportion of non-small cell lung cancer (NSCLC) on lung cancer is 85%, while more than 80% lung cancer patients are diagnosed with chronic obstructive pulmonary disease (COPD). In this study, we aimed to explore the potential mechanism of COPD induced NSCLC. Luciferase assay and reverse transcription-polymerase chain reaction (RT-PCR) were conducted to study the regulatory relationship between P53 and microRNA-675 (miR-675). Real-time PCR, Western-blot analysis, and MTT assay were performed to explore the impact of H19 and miR-675 in the signaling pathway involved in COPD induced NSCLC. In NSCLC patients with COPD, H19 and miR-675 levels were strikingly upregulated while P53 level was significantly downregulated. P53 was identified as a target gene of miR-675, and H19 remarkably upregulated miR-675, while H19 siRNA notably inhibited miR-675. In addition, miR-675 and H19 dramatically suppressed the expression of P53 and Bax while inducing the expression of Bcl-2. Finally, H19 and miR-675 induced proliferation of A549 and MRC-5 cells. These finding indicated that COPD (hypoxia)-induced H19 promoted expression of miR-675 associated with NSCLC though target apoptosis-related protein P53, BAX, and Bcl-2.

Upregulated lncRNA-UCA1 contributes to metastasis of bile duct carcinoma through regulation of miR-122/CLIC1 and activation of the ERK/MAPK signaling pathway

ABSTRACTIn the present study, we aimed to identify specific lncRNAs and miRNAs, as well as mRNAs, involved in bile duct carcinoma (BDC) and to further explore the way in which lncRNA UCA1 regulates cell metastasis ability. Differentially expressed RNAs were screened out from the TCGA database. In in vitro experiments, qRT-PCR was used to measure lncRNA UCA1, miR-122 and CLIC1 expression. We performed a dual luciferase assay to validate the target relationships among UCA1, CLIC1 and miR-122. The cell migration ability was measured by a wound healing assay, and Transwell assays were applied to detect cell invasive ability. Western blot analysis was employed to detect the expression of related proteins in the MAPK signaling pathway. According to the bioinformatics analysis, lncRNA UCA1 and CLIC1 were both significantly upregulated in BDC, while the expression of miR-122 declined compared with the normal group. The target relationship among UCA1, CLIC1 and miR-122 was verified. UCA1 promoted BDC cell migration and invasiveness, while miR-122 inhibited their progression. CLIC1 served as the downstream target gene of miR-122 and had opposite effects. The ERK/MAPK signaling pathway was activated after upregulating UCA1. LncRNA-UCA1 promoted the metastasis of BDC cells by regulating the expression of miR-122 and its downstream gene mRNA CLIC1 and promoted the activation of the ERK/MAPK pathway, which expanded the horizons of targeted therapy of cholangiocarcinoma.

Downregulation of microRNA-155 stimulates sevoflurane-mediated cardioprotection against myocardial ischemia/reperfusion injury by binding to SIRT1 in mice.

The inhaled sevoflurane has been demonstrated to protect against myocardial ischemia/reperfusion (I/R) injury. However, the relative mechanisms of sevoflurane-mediated cardioprotection remain largely unknown. This study intends to explore the effect of miR-155 on the sevoflurane-mediated cardioprotection by regulating Sirtuin 1 (SIRT1) in mouse models of myocardial I/R. Left anterior descending coronary artery ligation was used to induce models of myocardial I/R in mice. The I/R mice were treated with sevoflurane, sevoflurane + mimics negative control (NC) or sevoflurane + miR-155 mimics. The expression of microRNA-155 (miR-155) and SIRT1 was examined by quantitative real-time polymerase chain reaction and Western blot assay. Then cardiac functions and hemodynamic alterations were evaluated. Evans blue-2,3,5-triphenyltetrazolium chloride and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay staining methods were adopted to evaluate infarct size and cardiomyocyte apoptosis, respectively. In the I/R mice, miR-155 was expressed at a high level and SIRT1 at a low level. SIRT1 was confirmed to be a target gene of miR-155. The treatment of sevoflurane could reduce miR-155 expression and increased SIRT1 expression in the myocardial tissues, under which conditions, cardiac functions were promoted, accompanied by reduced infarct size and inhibited cardiomyocyte apoptosis. In response to miR-155 upregulation, the sevoflurane-treated I/R mice showed reduced cardiac functions, and increased infarct size and cardiomyocyte apoptosis. The findings obtained in this study provide evidence suggesting that miR-155 targets and negatively regulates SIRT1 expression, a mechanism by which the protection of sevoflurane is inhibited against myocardial I/R in mice.

MicroRNA-155 Promotes Myocardial Infarction-Induced Apoptosis by Targeting RNA-Binding Protein QKI.

Acute myocardial infarction (AMI) is the leading cause of sudden death worldwide. MicroRNA-155 (miR-155) has been reported to target antiapoptotic genes in various diseases models, but the functional role of miR-155 in response to MI injury needs further investigations. This study investigated the role of miR-155 in myocardial ischemia injury. TUNEL and flow cytometry were performed to measure cell apoptosis. Western blot analysis was employed to detect protein expressions of Bcl-2, XIAP, Bax, and caspase-3. qRT-PCR was used to quantify miRNA levels. We showed that miR-155 was dynamically elevated in murine hearts subjected to MI and in neonatal rat ventricular cardiomyocyte (NRVM) injury induced by hydrogen peroxide (H2O2). In response to H2O2, the silencing of miR-155 using AMO-155 (antisense inhibitor oligodeoxyribonucleotides) significantly increased cell viability and reduced cell apoptosis. Moreover, AMO-155 reversed the H2O2-induced downregulation of Bcl-2 and XIAP and upregulation of Bax and cleaved-caspase-3. Further study revealed that AMO-155 resulted in a decrease of H2O2-induced JC-1-labelled monomeric cell number. In addition, AMO-155 markedly decreased infarct size, ameliorated impaired cardiac function, and significantly reduced apoptotic cell percentages in MI mice heart. The RNA-binding protein Quaking (QKI) was predicted as a target gene of miR-155 through bioinformatic analysis, and AMO-155 attenuated the downregulation of QKI in H2O2-treated cardiomyocytes and MI mice heart. Knockdown of QKI by siRNA abolished the antiapoptotic effects of AMO-155. Taken together, miR-155 is upregulated in the MI heart and NRVMs in response to H2O2 stress, and downregulating of miR-155 protects cardiomyocytes against apoptosis. Mechanistically, it is probably due to the repression of QKI signaling pathway.

B cell-intrinsic and lymphocyte extrinsic miR-21 drive optimal germinal center and antibody responses

Abstract Germinal centers (GCs) generate high affinity B cell responses that are protective against infection but can produce autoreactive responses when dysregulated. MicroRNAs (miRNAs) have been implicated in the regulation of GC fate, though the role of many individual miRNAs remains uncharacterized. Here, we demonstrate that within the GC, miR-21 promotes T follicular helper cell (Tfh), T follicular regulatory cell (Tfr), and GC B cell responses, as well as downstream antibody production. Regulation of the GC response by miR-21 requires multiple mechanisms, occurring in both B cells and innate cells. B cell-intrinsic miR-21 drives GC B cell expansion by promoting B cell activation and proliferation. MiR-21 target gene expression arrays have revealed several putative target genes in B cells, suggesting that miR-21 targets negative regulators of proliferative pathways to enhance B cell proliferation and GC responses. In contrast, Tfh and Tfr are driven by miR-21 in a B and T cell extrinsic manner, likely by innate cells. Our data suggest that miR-21 modifies the cytokine microenvironment, which impacts regulatory T cell expansion and Tfh programs. Therefore, the synergy of B cell intrinsic and lymphocyte extrinsic miR-21 activity is required to generate optimal GC and Ab responses. Of clinical relevance, we also found that upregulation of miR-21 in autoimmune-prone mice drives autoantibody responses, implicating miR-21 in both anti-pathogen responses and its dysregulation in autoimmunity. Therefore, dampening miR-21 function may provide a strategy for autoimmune therapeutics. Alternatively, boosting miR-21 activity in healthy individuals could allow more efficient generation of protective antibody following vaccination.

Curcumin ameliorates atherosclerosis through upregulation of miR-126.

The potential usage of curcumin in diverse human diseases has been widely studied, including arteriosclerosis (AS). This study focused on investigating the relationship between curcumin and AS-associated microRNA, which may provide a better understanding of curcumin in a different mechanism. Human microvascular endothelial HMEC-1 cells were treated by curcumin alone or oxidized low-density lipoprotein (ox-LDL) plus curcumin, after which the following parameters were analyzed: cell viability, migration, and the expression of AS-associated factors. The regulatory effects of curcumin on miR-126 and signaling pathways involved in AS were then studied. Further, an animal model of AS was stimulated by feeding rabbits with 1% cholesterol diet. The effects of curcumin on the animal model were explored. We found that curcumin treatment significantly reduced HMEC-1 cells viability, migration, and the protein levels of MMP-2, MMP-9, and vascular endothelial growth factor (VEGF) in the presence or absence of ox-LDL. Meanwhile, the expression of VEGFR1 and VEGFR2 was repressed by curcumin. miR-126 was upregulated by curcumin. The abovementioned effects of curcumin on HMEC-1 cells were all attenuated when miR-126 was silenced. And also, VEGF was a target gene of miR-126, and curcumin could inhibit the activation of PI3K/AKT JAK2/STAT5 signaling pathways via miR-126. The effects of curcumin and its regulation on miR-126 and VEGF were confirmed in the animal model of AS. To sum up, curcumin exerted potent anti-AS property possibly via upregulating miR-126 and thereby inhibiting PI3K/AKT and JAK2/STAT5 signaling pathways.

Long noncoding RNA C2dat1 protects H9c2 cells against hypoxia injury by downregulating miR-22.

Myocardial ischemia is accompanied with hypoxia injury in myocardial cells. Long noncoding RNAs (lncRNA) CAMK2D-associated transcript 1 (C2dat1) C2dat1) has been linked with several ischemic diseases. However, the investigation regarding its role in myocardial ischemia is relatively rare. The aim of this study was to examine the role of C2dat1 in hypoxia response in H9c2 cells. H9c2 cells were subjected to hypoxia to evoke cell damage. Expressions of C2dat1, miR-22, and VEGF in H9c2 cells were altered by transfection, and then cell survival, migration, and invasion were respectively assessed posttransfection. Regulatory relationship between C2dat1, miR-22, and VEGF, as well as the involvement of PI3K/AKT/mTOR and JAK/STAT3 pathways in H9c2 cells injury was then studied. C2dat1 upregulation ameliorated hypoxia injury in H9c2 cells due to the increased viability, migration, and invasion, as well as the decreased apoptosis. miR-22 was negatively regulated by C2dat1. The effects of C2dat1 on H9c2 cells injured by hypoxia were attenuated when miR-22 was overexpressed. VEGF was a target gene of miR-22, and VEGF exerted similar protective effects to C2dat1. Finally, we found that silence of C2dat1 deactivated PI3K/AKT/mTOR and JAK/STAT3 pathways via regulating miR-22 and its downstream gene VEGF. C2dat1-miR-22-VEGF axis could regulate hypoxia injury in H9c2 cells. C2dat1 alleviated hypoxia injury possibly via downregulating miR-22, then upregulating VEGF, which further enhancing the activation of PI3K/AKT/mTOR and JAK/STAT3 pathways.

MiR-144 suppresses cell proliferation and invasion in gastric cancer through downregulation of activating enhancer-binding protein 4.

Gastric cancer (GC) is the most common malignant disease and its incidence rate is increasing rapidly worldwide. The molecular mechanisms underlying GC tumorigenesis require further investigation. The expression and physiological roles of microRNA-144 (miR-144) have been investigated in numerous types of tumor. However, its biological function in GC remains largely unknown. The reverse transcription- quantitative polymerase chain reaction was used to determine the expression of miR-144 in GC cells and normal gastric epithelial cells. An miR-144 mimic was transfected into HGC-27 cells. In addition, bioinformatics analysis was performed to identify the potential targets of miR-144. Protein expression, luciferase and rescue assays were used to confirm the target of miR-144. It was identified that the expression of miR-144 was significantly downregulated in GC cells compared with in normal gastric epithelial cells. Furthermore, overexpression of miR-144 suppressed HGC-27 cell proliferation, migration and invasion. Additionally, bioinformatics analysis suggested that the activating enhancer-binding protein 4 (AP4) is a target gene of miR-144. In addition, it was determined that miR-144 suppresses the expression of AP4 by binding directly to its 3'-untranslated regions. Furthermore, restoration of AP4 partially attenuated miR-144-induced inhibition of cell proliferation, migration and invasion. Therefore, the results of the present study suggest that miR-144 serves an important role in GC progression.

Role of microRNA-21 in airway remodeling in asthmatic mice

Objective Airway remodeling is an important pathological feature of asthma.This study is to investigate the role of microRNA-21 (miR-21) in airway remodeling in asthmatic mice. Methods A total of 16 female BALB/c mice were randomly divided into control group and asthma model group.Mice were sensitized and challenged by ovalbumin to establish a murine model of asthma.The mice in the normal control group were intraperitoneally injected with phosphate buffered saline for sensitization and given a phosphate buffered saline inhalation for the challenge.Twenty-four hours after the last aerosol inhalation, lung tissues of mice were sampled and subjectd to Western blot for testing expression of TGFβ type Ⅱ receptor, Smad7, and Collagen Type Ⅰ (COL Ⅰ) in lung tissue of mice of each group.Quantitative real-time PCR was used to test miR-21 expression in lung tissue of mice of each group.Target gene prediction software (TargetScan) was used to predict target gene of miR-21.293T cell was used to conduct dual-luciferase reporter gene assay for verification of miR-21 target gene. Results Compared with control group, asthma group had increased expression of COL Ⅰ protein and miR-21 in lung tissue (t=11.94, P<0.05; t=23.05, P<0.05). Smad7 and TGF-βRⅡ were target genes of miR-21. Conclusion miR-21 down-regulates Smad7, a target gene of miR-21, activates the TGFβ/Smad signaling pathway, and promotes airway remodeling, indicating that miR-21 may be a therapeutic target for the treatment of airway remodeling in asthma. Key words: MicroRNA-21; Target gene; Asthma; Airway remodeling; Mice

DNA Methylation of miR-122 Aggravates Oxidative Stress in Colitis Targeting SELENBP1 Partially by p65NF-κB Signaling.

Aberrant microRNA (miRNA) expressions contribute to the development and progression of various diseases, including Crohn's disease (CD). However, the accurate mechanisms of miRNAs in CD are definitely unclear. We employed colonic tissue samples from normal volunteers and CD patients, an acute mice colitis model induced by 2,4,6-trinitro-benzene-sulfonic acid (TNBS), and a cellular oxidative stress model induced by H2O2 in HT-29 cells to determine the effects of oxidative stress on expressions of miR-122, selenium-binding protein 1 (SELENBP1, SBP1), p65 nuclear factor κB (p65NF-κB) signaling, and DNA methylation. We found that SBP1 was mainly located on epithelial cells and was significantly increased in patients with active CD. SBP1 was the target gene of miR-122. miR-122 expression was downregulated while SBP1 expression was upregulated under TNBS-induced colitis or oxidative stress. Pre-miR-122 or siRNA SBP1 (si-SBP1) treatment ameliorated acute TNBS-induced colitis and H2O2-induced oxidative stress. Cotreatment of pre-miR-122 and si-SBP1 enhanced these effects. Besides, pre-miR-122 and si-SBP1 obviously activated the p65NF-κB signaling by phosphorylation of IκBα. Bisulfite sequencing of the CpG islands in the promoter region of miR-122 showed that CpG methylation was significantly increased under oxidative stress. Treating cells with 5′-AZA which was well known as a DNA-demethylating agent significantly increased miR-122 expression. Our results suggest that oxidative stress-induced DNA methylation of miR-122 aggravates colitis targeting SELENBP1 partially by p65NF-κB signaling and may promote the progression of CD.