Regulation of immune cells by miR-451 and its potential as a biomarker in immune-related disorders: a mini review.

In 2005, Altuvia and colleagues were the first to identify the gene that encodes miR-451 in the human pituitary gland, located in chromosome region 17q11.2. Subsequent studies have confirmed that miR-451 regulates various immune cells, including T cells, B cells, microglia, macrophages, and neutrophils, thereby influencing disease progression. The range of immune-related diseases affected encompasses various cancers, lymphoblastic leukemia, and injuries to the lungs and spinal cord, among others. Moreover, miR-451 is produced by immune cells and can regulate both their own functions and those of other immune cells, thus creating a regulatory feedback loop. This article aims to comprehensively review the interactions between miR-451 and immune cells, clarify the regulatory roles of miR-451 within the immune system, and assess its potential as both a therapeutic target and a biomarker for immune-related diseases.

[Expression of MiR-144/451 in Different Types of Anemia].

OBJECTIVE: To investigate the expression level and clinical correlation of microRNA-144/451 gene cluster (miR-144/451) in different types of anemia. METHODS: The peripheral blood of patients with aplastic anemia (AA), myelodysplastic syndrome (MDS) and diffuse large B-cell lymphoma (DLBCL) who had been diagnosed with anemia for the first time and after chemotherapy were collected. The expression levels of miR-144 and miR-451 were measured by RT-qPCR, and the correlation between the expression levels of miR-144 and miR-451 and routine laboratory indexes was analyzed by Spearman correlation analysis. RESULTS: The expression levels of miR-144 and miR-451 in the peripheral blood of AA and MDS patients were significantly lower than those in normal controls (all P < 0.01). No statistical differences were observed in the expression level of miR-144 in three subgroups of DLBCL patients (P >0.05), while the expression level of miR-451 in peripheral blood of three subgroups of DLBCL patients were significantly higher than those in normal controls (all P < 0.05). Correlation analysis showed that the expression levels of miR-144 and miR-451 in AA patients were positively correlated with red blood cell distribution width-coefficient of variation (RDW-CV) (r =0.629, 0.574). There were no significant correlations between the expression levels of miR-144 and miR-451 and laboratory parameters in MDS and DLBCL patients. CONCLUSION: Different types of anemia disorders have varying levels of miR-144 and miR-451 expression, which is anticipated to develop into a secondary diagnostic and differential diagnostic indicator for clinical anemia diseases.

ß stimulator induces upregulation of miR-27a in the rat heart one hour after the injection.

MicroRNAs (miRs) are non-coding small RNA containing 18 to 22 nucleotides, that post-transcriptionally regulates mRNA expression. Chronic injection of ß stimulator is known to induce cardiac injury and change of miRs expression level in the heart with some pathological changes such as fibrosis, heart failure, myocardial infarction. We investigated the changes in the expression level of miRs in the rat heart one hour after isoproterenol (a ß stimulator) injection. Male Sprague-Dawley rats were assigned into three groups and received subcutaneous injection of normal sarin (NS) or 0.1 mg/kg isoproterenol (ISO-0.1) or 10 mg/kg isoproterenol (ISO-10). After one hour, we collected their heart and plasma. Total RNA was extracted from the left ventricle and used for deep miRNA sequencing. Based on the results of miRNA sequencing, we performed real-time polymerase chain reaction (RT-PCR) using 8 miR primers. Cardiac injury was evaluated by hematoxylin and eosin, and phosphotungstic acid-hematoxylin staining and measuring troponin-I levels in plasma. Troponin-I was significantly increased in ISO-0.1 and ISO-10 groups, but histological observation did not show any cardiac necrosis. miRNA sequencing identified 14 upregulated miRs and 12 downregulated miRs. Of the 26 miRs, RT-PCR confirmed miR-144-3p/5p and miR-451-5p were decreased, and that 5 miRs (miR-27a-5p, miR-30b-3p, miR-92a-1-5p, miR-132-5p, miR-582-3p) were upregulated. This study showed that ß stimulus causes downregulation of miR-144/451 cluster and increases expression of five 5 miRs in the heart, especially 6.5-fold upregulation of miR-27a-5p as early as one hour after isoproterenol injection. Therefore, these miRs might be good biomarkers for cardiac injury.

Mechanism of Zhenwu Decoction modulating TLR4/NF-κB/HIF-1α loop through miR-451 to delay renal fibrosis in type 2 CRS.

BACKGROUND: Type 2 cardiorenal syndrome (CRS) is a progressive renal insufficiency in patients with chronic heart failure, but its pathophysiology is still unclear. The Chinese medicine Zhenwu Decoction plays an important role in the prevention and treatment of 2-CRS, however, its mechanism of action remains unknown. PURPOSE: The aim of this study was to investigate whether the ameliorative effect of ZWD on 2-CRS renal fibrosis is related to the modulation of miR-451 expression and thus mediating the TLR4/NF-κB/HIF-1α loop. STUDY DESIGN AND METHODS: A type 2 CRS rat model was constructed using ligation of the left anterior descending branch of the coronary artery + 3/4 nephrectomy, and randomly divided into Control, Sham, Model, Captopril, ZWD-L, ZWD-M and ZWD-H groups.After 4 weeks of ZWD intervention, its effects on cardiac and renal functions of type 2 CRS rats were observed by hematuria and cardiac ultrasonography. Changes in kidney tissue morphology were observed by HE, Masson and PASM staining. The protein and mRNA expression of TLR4, NF-κB, HIF-1α and IκBα in kidney tissues were detected by immunohistochemistry and qPCR. Immunofluorescence was used to detect the protein expression of NF-κB and HIF-1α in renal tissues. Western blot and qPCR were used to detect the protein expression of MCP-1, ICAM-1, IL-1ß, IL-6, TGF-ß, α-SMA, FN, Smad2, Smad3, and E-cadherin in renal tissues. PCR was used to detect the protein expression of miR-451mRNA expression level in kidney tissues. RESULTS: In this study, we found that ZWD was able to reduce the expression of Scr, BUN, NT-proBNP, and 24-hour quantitative urine protein, elevate LVEF, FS, CO, and reduce the level of LVIDS in type 2 CRS rats, as well as attenuate renal interstitial fibrosis and improve tubular swelling. In addition, Zhenwu Decoction up-regulated the expression of miR-451 in renal tissues and inhibited the expression of TLR4, NF-κB, and HIF-1α proteins and genes, which in turn inhibited the expression of inflammatory factors and fibrosis-related factors. CONCLUSION: ZWD was able to up-regulate the expression of miR-451 in renal tissues, inhibit the TLR4/NF-κB/HIF-1α response loop, and then inhibit the expression of inflammatory factors and fibrosis-related factors, improve renal fibrosis, and delay the pathological process of type 2 CRS.

Diagnostic and Prognostic Value of miR-451 Expression in Colorectal Cancer: A Meta-Analysis.

BACKGROUND: The miR-451 has been reported to play an important role in colorectal cancer (CRC) pathogenesis and can be a pivotal diagnosis biomarker of CRC. Given the contradictions in the diagnosis value of the miR-451 in patients with CRC, deciphering the diagnostic/prognostic role of this miRNA in CRC will support the identification of a novel therapeutic target for CRC. Therefore, in the present meta-analysis, we evaluated the diagnostic value of miR-451 in CRC patients. MATERIALS AND METHODS: The electronic databases of Embase, PubMed, ISI Web of Science, and Scopus systematically searched for relevant studies. The odds ratio (OR) with a 95% confidence interval (CI) was calculated to evaluate the association between miR-451 family expression and diagnosis of colorectal cancer. The parameters including sensitivity, specificity, and area under the curve (AUC) were obtained. The quality of evidence was evaluated using the Newcastle-Ottava Scale (NOS). RESULTS: This study involved 510 patients (45% female and 55% male) with CRC. The pooled analysis of the studies showed a significant association between low expression levels of miR-451 in patients with CRC (OR = 7.59; 95% CI 2.39 - 24.07; p = 0.001). The overall sensitivity and specificity were 0.95 (0.61 - 1) and 0.83 (0.43 - 0.99), respectively. The pooled AUC was 0.97 (0.88 - 1; p < 0.006). Results showed if the pre-test probability is 50% for a patient, the post-test probability will be 85%. The indices demonstrated the high potency of miR-451 as a diagnostic biomarker in patients with CRC. No publication bias was observed using the Begg's (p=0.85) and Egger's tests (p=0.45). CONCLUSION: A strong relationship between the low expression levels of miR-451 and CRC progression was observed. This finding suggests the miR-451 family may be helpful as a potential biomarker for the earlier diagnosis of colorectal cancer.

MicroRNA-451 Regulates Angiogenesis in Intracerebral Hemorrhage by Targeting Macrophage Migration Inhibitory Factor.

Intracerebral hemorrhage (ICH) is a subtype of stroke with the highest fatality and disability rate. Up to now, commonly used first-line therapies have limited value in improving prognosis. Angiogenesis is essential to neurological recovery after ICH. Recent studies have shown that microRNA-451(miR-451) plays an important role in angiogenesis by regulating the function of vascular endothelial cells. We found miR-451 was significantly decreased in the peripheral blood of ICH patients in the acute stage. Based on the clinical findings, we conducted this study to investigate the potential regulatory effect of miR-451 on angiogenesis after ICH. The expression of miR-451 in ICH mouse model and in a hemin toxicity model of human brain microvascular endothelial cells (hBMECs) was decreased the same as in ICH patients. MiR-451 negatively regulated the proliferation, migration, and tube formation of hBMECs in vitro. MiR-451 negatively regulated the microvessel density in the perihematoma tissue and affected neural functional recovery of ICH mouse model. Knockdown of miR-451 could recovered tight junction and protect the integrity of blood-brain barrier after ICH. Based on bioinformatic programs, macrophage migration inhibitory factor (MIF) was predicted to be the target gene and identified to be regulated by miR-451 inhibiting the protein translation. And p-AKT and p-ERK were verified to be downstream of MIF in angiogenesis. These results all suggest that miR-451 will be a potential target for regulating angiogenesis in ICH.

Exosomal SOX21-AS1 Regulates EREG by Sponging miR-451a and Promotes the Malignancy of Pancreatic Ductal Adenocarcinoma.

The incidence and mortality of pancreatic ductal adenocarcinoma (PDAC) have increased. Exosomes, as a regulatory mode of intercellular communication, contain lncRNAs. SOX21-AS1 has been studied in other cancers, and its expression is elevated in PDAC, but its role in PDAC remains unclear. First, we analyzed the expression of lncRNAs in PDAC tissues and nontumor tissues through the TCGA database. Next, the results of the RT-qPCR experiment confirmed the prediction that the expression of SOX21-AS1 was elevated in PDAC tissues. In vivo and in vitro cell function assays confirmed that the degree of malignancy of PDAC was proportional to the expression of SOX21-AS1. In addition, through exosome isolation and uptake experiments, we first found that PDAC could secrete exosomal SOX21-AS1 and play an angiogenic role in HUVECs. Subsequently, the relationship between SOX21-AS1, miR-451a and epiregulin (EREG) was verified through database prediction and analysis and RIP assays. Finally, functional recovery assays in vivo and in vitro verified that SOX21-AS1 regulates the expression of EREG through combination with miR-451a and thus promotes the malignancy of PDAC. SOX21-AS1 was upregulated in PDAC. The upregulation of SOX21-AS1 can stimulate the proliferation, migration, invasion, stemness and epithelial-mesenchymal transition (EMT) progression of PDAC cells. Furthermore, PDAC cells secrete exosomal SOX21-AS1, which is absorbed by HUVECs and promotes angiogenesis. Our study first identified that SOX21-AS1 promotes the malignancy of PDAC through the SOX21-AS1/miR-451a/EREG axis, and also that exosomal SOX21-AS1 promotes angiogenesis in PDAC.

c-Jun targets miR-451a to regulate HQ-induced inhibition of erythroid differentiation via the BATF/SETD5/ARHGEF3 axis.

Benzene, a widely used industrial chemical, has been clarified to cause hematotoxicity. Our previous study suggested that miR-451a may play a role in benzene-induced impairment of erythroid differentiation. However, the mechanism underlying remains unclear. In this study, we explored the role of miR-451a and its underlying mechanisms in hydroquinone (HQ)-induced suppression of erythroid differentiation in K562 cells. 0, 1.0, 2.5, 5.0, 10.0, and 50 µM HQ treatment of K562 cells resulted in a dose-dependent inhibition of erythroid differentiation, as well as the expression of miR-451a. Bioinformatics analysis was conducted to predict potential target genes of miR-451a and dual-luciferase reporter assays confirmed that miR-451a can directly bind to the 3'-UTR regions of BATF, SETD5, and ARHGEF3 mRNAs. We further demonstrated that over-expression or down-regulation of miR-451a altered the expression of BATF, SETD5, and ARHGEF3, and also modified erythroid differentiation. In addition, BATF, SETD5, and ARHGEF3 were verified to play a role in HQ-induced inhibition of erythroid differentiation in this study. Knockdown of SETD5 and ARHGEF3 reversed HQ-induced suppression of erythroid differentiation while knockdown of BATF had the opposite effect. On the other hand, we also identified c-Jun as a potential transcriptional regulator of miR-451a. Forced expression of c-Jun increased miR-451a expression and reversed the inhibition of erythroid differentiation induced by HQ, whereas knockdown of c-Jun had the opposite effect. And the binding site of c-Jun and miR-451a was verified by dual-luciferase reporter assay. Collectively, our findings indicate that miR-451a and its downstream targets BATF, SETD5, and ARHGEF3 are involved in HQ-induced erythroid differentiation disorder, and c-Jun regulates miR-451a as a transcriptional regulator in this process.

miR-451a suppresses the proliferation and migration of high-grade serous ovarian cancer by targeting RAB5A through the Ras/Raf/MEK/ERK pathway.

BACKGROUND: Ovarian cancer is one of the most common cancers in women. Profiles changes of microRNAs (miRNAs) are closely linked to malignant tumors. In the present study, we investigated expression of miR-451a in high-grade serous ovarian cancer (HGSOC). We also investigated the potential pathological roles and the likely mechanism of miR-451a in the development of HGSOC using animal models and cell lines. METHODS: Using bioinformatics techniques and a real-time PCR, we analyzed differently expressed miRNAs in HGSOC compared to normal tissue. MTT (i.e. 3-[4, 5-dimethyl thiazol-2-yl]-2,5-diphenyl tetrazolium bromide), EDU (i.e. 5-ethynyl-2'-deoxyuridine) and transwell assays were performed to investigate the effect of miR-451a on the proliferation and migration of HGSOC SKOV-3 cells. A dual luciferase reporter assay was performed to verify the targeting relationship of miR-451 and RAB5A (one of the Rab GTPase proteins that regulates endocytosis and vesicle transport). Also, we analyzed levels of the RAB5A mRNA and protein by real-time PCR, western blotting and immunohistochemistry assays in HGSOC cells and tissues. Finally, we performed in vivo experiments using HGSOC mice. RESULTS: miR-451a was substantially upregulated in HGSOC and associated with favorable clinical characteristics. miR-451a knockdown significantly increased growth and metastasis of HGSOC cell line SKOV-3 through Ras/Raf/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling. In addition, RAB5A, an early endosome marker, was shown to be a direct target of miR-451a. Moreover, RAB5A is correlated with unfavorable clinical features and shows independent prognostic significance in HGSOC. CONCLUSIONS: We found that the miR-451a/RAB5A axis is associated with tumorigenesis and progression through the Ras/Raf/MEK/ERK pathway, providing prognostic indicators and therapeutic targets for patients with HGSOC.

To Assess the Role of microRNA-451 in the Progression and Metastasis of Colorectal Cancer.

The study aimed to determine the expression of miR451 in colorectal cancer (CRC) subjects with CRC cells, and the role of miR451 in colorectal cancer cells. In October 2020, ATC purchased CRC and normal mucosal cell lines of CRC and implanted them in DMEM with 10% fetal serum. The suitability of the HT29 cell line is verified using the STR profile. In an incubator with 5% CO2, enlarged cells were placed at 37 °C. TCGA data was used to select the top 120 patients with a high voice and the lowest 120 patients with a low voice. Cells were collected and coated with Annexin V and PE according to the manufacturer's instructions after 24.0 h. After that, the cells were separated. Cells were also tested using flow cytometry. HCT-120 cells were transplanted into a concentration of 5×105/ml cells in 6-source plates. HCT120 cells in the experimental group were combined with miR451 mimics, miR451 inhibitors, or miR451 miR + SMAD4B for 12 h at 37 °C, and cells were collected 24 h later at 37 °C. The sample was injected with 5 ml of Annexin VFITC and PE. Compared with normal colorectal mucosal cells, CRC cell lines decreased miR451 expression levels (fetal human cells (FHC) and HCoEpiC). Then, the HCT120 cells were transfected with miR451 inhibitors, and 72 h after transfection, say of miR451 was normal. There was a significant decrease in cell function in the miR451mimic groups, but an increase when the miR451 was blocked. The proliferation of cancer cells was prevented and chemotherapy was effective when miR451 was overexpressed. The SMAD4 gene provides instructions for making a protein involved in transmitting chemical signals from the cell surface to the nucleus. The SMAD4B expression was tested by RT-qPCR and Western blotting after 72.0 h of transmission. The mRNA and protein expression of SMAD4B decreased significantly when miR451 was significantly higher than when inhibited, as revealed in the results of this study. Seventy-two hours after transplantation, mRNA levels and SMAD4B proteins were measured in HCT120 cells. In addition, the researchers in this study investigated whether miR451 was associated with SMAD4B-directed control of CRC growth and migration. It was found that SMAD4B is highly expressed in both CRC and para-cancer tissues while using the TCGA database to detect SMAD4B expression. Patients with CRC with SMAD4B have a severe prognosis. MiR451 is sensitive to depressive disorders by targeting SMAD4B, according to these studies. We found that miR451 inhibited cell growth and migration, made CRC cells more readily available in chemotherapy, and did so by targeting SMAD4B. The findings suggest that miR451 and its genetic predisposition, SMAD4B, may help predict the prognosis and course of cancer patients. Treatments that target the miR451/SMAD4B axis may be helpful to people with CRC.

Investigating the role of LncRNA PSMG3-AS1 in gastric cancer: implications for prognosis and therapeutic intervention.

LncRNAs are widely linked to the complex development of gastric cancer, which is acknowledged worldwide as the third highest contributor to cancer-related deaths and the fifth most common form of cancer. The primary focus of this study is to examine the role of LncRNA PSMG3-AS1 in a group of individuals with gastric cancer. The results of our study indicate that PSMG3-AS1 is highly expressed in over 20 different types of cancer. Significantly, there was a clear association found between the expression of PSMG3-AS1 and a multitude of TMB and MSI tumors. PSMG3-AS1 exhibited significant upregulation in gastric cancer patients compared to healthy individuals within the gastric cancer cohort. The prognosis of gastric cancer patients is intrinsically associated with PSMG3-AS1, as confirmed by survival analysis and ROC curves. Furthermore, we created a disruption vector based on LncRNA PSMG3-AS1 and introduced it into AGS and MKN-45 cells, which are human gastric cancer cells. Significant decreases in the expression of the PSMG3-AS1 gene were noticed in both intervention groups compared to the NC group, reflecting the protein level expressions. Significantly, the proliferative and invasive capabilities of MKN-45 and AGS cells were notably reduced following transfection with PSMG3-AS1 siRNA. The results of our study indicate that disruption of the LncRNA PSMG3-AS1 gene may impact the CAV1/miR-451a signaling pathway, thereby leading to a reduction in the ability of gastric cancer cells to multiply and invade.

HOXD9/miR-451a/PSMB8 axis is implicated in the regulation of cell proliferation and metastasis via PI3K/AKT signaling pathway in human anaplastic thyroid carcinoma.

Anaplastic thyroid carcinoma (ATC) is a deadly disease with a poor prognosis. Thus, there is a pressing need to determine the mechanism of ATC progression. The homeobox D9 (HOXD9) transcription factor has been associated with numerous malignancies but its role in ATC is unclear. In the present study, the carcinogenic potential of HOXD9 in ATC was investigated. We assessed the differential expression of HOXD9 on cell proliferation, migration, invasion, apoptosis, and epithelial-mesenchymal transition (EMT) in ATC and explored the interactions between HOXD9, microRNA-451a (miR-451a), and proteasome 20S subunit beta 8 (PSMB8). In addition, subcutaneous tumorigenesis and lung metastasis in mouse models were established to investigate the role of HOXD9 in ATC progression and metastasis in vivo. HOXD9 expression was enhanced in ATC tissues and cells. Knockdown of HOXD9 inhibited cell proliferation, migration, invasion, and EMT but increased apoptosis in ATC cells. The UCSC Genome Browser and JASPAR database identified HOXD9 as an upstream regulator of miR-451a. The direct binding of miR-451a to the untranslated region (3'-UTR) of PSMB8 was established using a luciferase experiment. Blocking or activation of PI3K by LY294002 or 740Y-P could attenuate the effect of HOXD9 interference or overexpression on ATC progression. The PI3K/AKT signaling pathway was involved in HOXD9-stimulated ATC cell proliferation and EMT. Consistent with in vitro findings, the downregulation of HOXD9 in ATC cells impeded tumor growth and lung metastasis in vivo. Our research suggests that through PI3K/AKT signaling, the HOXD9/miR-451a/PSMB8 axis may have significance in the control of cell proliferation and metastasis in ATC. Thus, HOXD9 could serve as a potential target for the diagnosis of ATC.

Circulating miR-3613-5p but not miR-125b-5p, miR-199a-3p, and miR-451a are biomarkers of endometriosis.

OBJECTIVE: This study aimed to assess the utility of circulating miR-125b-5p, miR-199a-3p, miR-451a, and miR-3613-5p as biomarkers of endometriosis. STUDY DESIGN: Patients with stage III or IV of endometriosis according to the revised American Society of Reproductive Medicine (rASRM) staging classification, as well as control women, were recruited. We created a prospective study conducted on a group of 48 patients (n = 25 controls, n = 24 endometriosis) who had laparoscopic surgery. Blood samples were taken and plasma miRNA levels were measured by quantitative real-time polymerase chain reaction (RT-qPCR) and assessed with AUC and ROC curves. RESULTS: MiR-451a and miR-3613-5p were significantly decreased in the plasma of endometriosis patients. miR-451a had a receiver-operating characteristic (ROC) area under the curve 0.8283 and miR-3613-5p had a ROC area under the curve 0.7617. The concentration of circulating miR-125b-5p and miR-199-3p did not differ between endometriosis patients and controls. Plasma miRNA levels did not change with BMI, smoking status, fertility problems, or menstrual pain according to the VAS scale (p > 0.05). CONCLUSION: Circulating miR-451a and miR-3613-5p levels significantly differed between endometriosis and controls. However, the levels of miR-451a were discordant with previous studies. Therefore, miR-3613-5p may have better potential as the endometriosis biomarker. Circulating miR-125b-5p and miR-199a-3p cannot be used as reliable markers of endometriosis.

Characteristics of microRNAs in Skeletal Muscle of Intrauterine Growth-Restricted Pigs.

microRNAs are a class of small RNAs that have been extensively studied, which are involved in many biological processes and disease occurrence. The incidence of intrauterine growth restriction is higher in mammals, especially multiparous mammals. In this study, we found that the weight of the longissimus dorsi of intrauterine growth-restricted pigs was significantly lower than that of normal pigs. Then, intrauterine growth-restricted pig longissimus dorsi were used to characterize miRNA expression profiles by RNA sequencing. A total of 333 miRNAs were identified, of which 26 were differentially expressed. Functional enrichment analysis showed that these differentially expressed miRNAs regulate the expression of their target genes (such as PIK3R1, CCND2, AKT3, and MAP3K7), and these target genes play an important role in the proliferation and differentiation of skeletal muscle through signaling pathways such as the PI3K-Akt, MAPK, and FoxO signaling pathways. Furthermore, miRNA-451 was significantly upregulated in IUGR pig skeletal muscle. Overexpression of miR-451 in C2C12 cells significantly promoted the expression of Mb, Myod, Myog, Myh1, and Myh7, suggesting that miR-451 may be involved in the regulation of the myoblastic differentiation of C2C12 cells. Our results reveal the role of miRNA-451 in regulating myogenic differentiation of skeletal muscle in pigs with intrauterine growth restriction.

Circulating miR-26b-5p and miR-451a as diagnostic biomarkers in medullary thyroid carcinoma patients.

PURPOSE/METHODS: The determination of tumour biomarkers is paramount to advancing personalized medicine, more so in rare tumours like medullary thyroid carcinoma (MTC), whose diagnosis is still challenging. The aim of this study was to identify non-invasive circulating biomarkers in MTC. To achieve this goal, paired MTC tissue and plasma extracellular vesicle samples were collected from multiple centres and microRNA (miRNA) expression levels were evaluated. RESULTS: The samples from a discovery cohort of 23 MTC patients were analysed using miRNA arrays. Lasso logistic regression analysis resulted in the identification of a set of circulating miRNAs as diagnostic biomarkers. Among them, miR-26b-5p and miR-451a, were highly expressed and their expression decreased during follow-up in disease-free patients in the discovery cohort. Circulating miR-26b-5p and miR-451a were validated using droplet digital PCR in a second independent cohort of 12 MTC patients. CONCLUSION: This study allowed the identification and validation of a signature of two circulating miRNAs, miR-26b-5p and miR-451a, in two independent cohorts reporting a significant diagnostic performance for MTC. The results of this study offer advancements in molecular diagnosis of MTC proposing a novel non-invasive tool to use in precision medicine.

Decreased miR-451a in cerebrospinal fluid, a marker for both cognitive impairment and depressive symptoms in Alzheimer's disease.

Background: Alzheimer's disease (AD) patients are often accompanied by depressive symptoms, but its underlying mechanism remains unclear. The present study aimed to explore the potential role of microRNAs in the comorbidity of AD and depression. Methods: The miRNAs associated with AD and depression were screened from databases and literature and then confirmed in the cerebrospinal fluid (CSF) of AD patients and different ages of transgenic APP/PS1 mice. AAV9-miR-451a-GFP was injected into the medial prefrontal cortex (mPFC) of APP/PS1 mice at seven months, and four weeks later, a series of behavioral and pathological analyses were performed. Results: AD patients had low CSF levels of miR-451a, which was positively correlated with the cognitive assessment score, but negatively with their depression scale. In the mPFC of APP/PS1 transgenic mice, the miR-451a levels also decreased significantly in the neurons and microglia. Specific virus vector-induced overexpression of miR-451a in the mPFC of APP/PS1 mice ameliorated AD-related behavior deficits and pathologies, including long-term memory defects, depression-like phenotype, ß-amyloid load, and neuroinflammation. Mechanistically, miR-451a decreased the expression of neuronal ß-secretase 1 of neurons through inhibiting Toll-like receptor 4/Inhibitor of kappa B Kinase ß/ Nuclear factor kappa-B signaling pathway and microglial activation by inhibiting activation of NOD-like receptor protein 3, respectively. Conclusion: This finding highlighted miR-451a as a potential target for diagnosing and treating AD, especially for those with coexisting symptoms of depression.

[The Role and Mechanism of MiR-451 in Multidrug Resistance of Leukemia Cell Line K562/A02].

OBJECTIVE: To detect the differential expressions of miR-451, ABCB1 and ABCC2 in drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, and explore the regulatory relationship between miR-451 and the expressions of ABCB1 and ABCC2 , and the mechanism of miR-451 involved in drug resistance in leukemia. METHODS: CCK-8 assay was used to detect the drug resistance of K562/A02 and K562 cells. Quantitative Real-time PCR (qRT-PCR) was used to verify the differential expressions of miR-451 in K562 and K562/A02 cells. MiR-451 mimic and negative control (miR-NC), miR-451 inhibitor and negative control (miR-inNC) were transfected into K562 and K562/A02 cells respectively, then qRT-PCR and Western blot were used to detect the expression levels of mRNA and protein of ABCB1 and ABCC2 in K562 and K562/A02 cells and the transfected groups. RESULTS: The drug resistance of K562/A02 cells to adriamycin was 177 times higher than that of its parent cell line K562. Compared with K562 cells, the expression of miR-451 in K562/A02 cells was significantly higher (P <0.001), and the mRNA and protein expression levels of ABCB1 and ABCC2 in K562/A02 cells were significantly higher than those in K562 cells (P <0.001). After transfected with miR-451 inhibitor, the expression of miR-451 was significantly down-regulated in K562/A02 cells (P <0.001), the sensitivity to chemotherapy drugs was significantly enhanced (P <0.05), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly decreased (P <0.01). After transfected with miR-451 mimic, the expression of miR-451 was significantly upregulated in K562 cells (P <0.001), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly increased (P <0.01). CONCLUSION: There are significant differences in the expressions of miR-451, ABCB1 and ABCC2 between the drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, which suggests that miR-451 may affect the drug resistance of leukemia cells by regulating the expression of ABCB1 and ABCC2.

Effects of Banxia Xiexin Decoction on apoptosis of interstitial cells of Cajal via regulation of MiR-451-5p: An in vivo and in vitro study.

ETHNOPHARMACOLOGICAL RELEVANCE: Banxia Xiexin Decoction (BXD) is a traditional Chinese medical formula applied to gastrointestinal (GI) motility disorders. Previous studies showed that miR-451-5p was down-regulated in rats with GI motility disorders induced by gastric electrical dysrhythmia. Interstitial cells of Cajal (ICCs) are pacemakers for GI motility, while loss of ICCs is responsible for GI motility disturbance. Thus, the underlying interaction mechanisms for BXD regulating ICCs apoptosis via miR-451-5p remain to be explored. AIM OF THE STUDY: In this work, the main objectives were to examine the efficacy of BXD on ICCs via miR-451-5p both in GI motility disorders rats model and in vitro, as well as the potential contributions of SCF/c-kit signaling. MATERIALS AND METHODS: Rats with gastric electrical dysrhythmia were established in male SD rats by using a single-day diet and a double fasting method (drinking diluted hydrochloric acid water during the period) for 4 weeks. The gastric slow wave (GSW) recording, RT-qPCR, and western blot were performed to examine the effects of BXD on ICCs apoptosis in rats with GED and miR-451-5p expression. In vitro assays included CCK-8, flow cytometry analysis, RT-qPCR, and western blot were applied to investigate the potential molecular mechanism of BXD on ICCs apoptosis via miR-451-5p. RESULTS: BXD promoted gastric motility, reduced ICCs apoptosis, and elevated miR-451-5p in GED rats. In addition, miR-451-5p was significantly up-regulated in ICCs after BXD treatment compared with that in ICCs with miR-451-5p inhibitor transfection. Meanwhile, high miR-451-5p expression with either BXD treatment or miRNA mimics enhanced ICCs proliferation and inhibit apoptosis. Moreover, overexpression of miR-451-5p can reverse G0/G1 arrest in ICCs by BXD treatment. Further, SCF and c-kit protein levels were detected to demonstrate that modulation of miR-451-5p by BXD treatment was involved in this signaling. CONCLUSIONS: Through this study, we demonstrated that BXD could promote ICCs proliferation and inhibit apoptosis via miR-451-5p and may involve the modulations of SCF/c-kit signaling, thus suggesting a new therapy basis for GI motility dysfunction from the perspective of modulation of ICCs apoptosis by targeting miR-451-5p.

miR-139-5p and miR-451a as a Diagnostic Biomarker in LUSC.

Background: Lung squamous cell carcinoma (LUSC) is a type of lung cancer that originates from segmental or subsegmental bronchial mucosa. There is evidence that miRNA plays an important role in the occurrence and progression of tumors. Methods: In this study, plasma samples of patients with early LUSC and healthy volunteers were subjected to miRNA sequencing, and the levels of differentially expressed miRNAs (DEMs) in LUSC tissues were analyzed using R language. Cox regression and Kaplan-Meier (K-M) survival curve analyses were performed to determine the relationship between DEMs and prognosis in LUSC, and PCR method was verified for the plasma expression level of DEMs in patients with LUSC. The levels of CYFRA21-1 and SCC-Ag in plasma were measured, and area under curve (AUC) was used to evaluate the diagnostic value of the DEMs. Results: A total of 21 DEMs were screened out by sequencing. The expression levels of DEMs in tissue samples in the TCGA database were analyzed, and four DEMs with consistent expression levels were further screened from plasma and tissue samples. Regression analysis and K-M curve were performed to select two DEMs (miR-139-5p, miR-451a) that were correlated with the prognosis. PCR verification results showed that the levels of miR-451a and miR-139-5p were low in patients, and the level of miR-139-5p in late stages III & IV with the patients of LUSC was higher than that in stages I & II. The AUC values of the four indicators (SCC-Ag, CYFRA21-1, miR-451a and miR-139-5p) in the diagnosis of LUSC, early and late cases were 0.884, 0.935 and 0.778, respectively. Conclusion: The detection of miR-139-5p and miR-451a levels in plasma has a certain potential in the non-invasive diagnosis, especially in patients with early stages of LUSC.

[Discovery of miRNA and target signal molecules involved in inhibition of chlorogenic acid on N-acetyl-p-aminophenol-induced hepatotoxicity based on microRNA array].

This study aims to observe the effect of chlorogenic acid(CGA) on microRNA(miRNA) in the process of protecting against N-acetyl-p-aminophenol(APAP)-induced liver injury. Eighteen C57BL/6 mice were randomly assigned into a normal group, a model group(APAP, 300 mg·kg~(-1)), and a CGA(40 mg·kg~(-1)) group. Hepatotoxicity of mice was induced by intragastric administration of APAP(300 mg·kg~(-1)). The mice in the CGA group were administrated with CGA(40 mg·kg~(-1)) by gavage 1 h after APAP administration. The mice were sacrificed 6 h after APAP administration, and plasma and liver tissue samples were collected for the determination of serum alanine/aspartate aminotransferase(ALT/AST) level and observation of liver histopathology, respectively. MiRNA array combined with real-time PCR was employed to discover important miRNAs. The target genes of miRNAs were predicted via miRWalk and TargetScan 7.2, verified by real-time PCR, and then subjected to functional annotation and signaling pathway enrichment. The results showed that CGA administration lowered the serum ALT/AST level elevated by APAP and alleviate the liver injury. Nine potential miRNAs were screened out from the microarray. The expression of miR-2137 and miR-451a in the liver tissue was verified by real-time PCR. The expression of miR-2137 and miR-451a was significantly up-regulated after APAP administration, and such up-regulated expression was significantly down-regulated after CGA administration, consistent with the array results. The target genes of miR-2137 and miR-451a were predicted and verified. Eleven target genes were involved in the process of CGA protecting against APAP-induced liver injury. Gene Ontology(GO) annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment with DAVID and R language showed that the 11 target genes were enriched in Rho protein-related signal transduction, vascular patterning-related biological processes, binding to transcription factors, and Rho guanyl-nucleotide exchange factor activity. The results indicated that miR-2137 and miR-451a played an important role in the inhibition of CGA on APAP-induced hepatotoxicity.