ObjectiveTo explore the dynamic expression changes of neuronal growth and differentiation-associated miR-124a and miR-9 in the process of epileptogenesis. MethodsEstablish the lithium-pilocarpine induced status epilepticus (SE) rat model. Animal behavior change induced by SE as well as in the period of chronic epilepsy was observed by naked-eye or video-recording. Major time points for the study were chosen at 1d, 7d, 14d and 28d post-SE, on which the post-SE rats were decapitated and their hippocampal specimens were obtained. Total RNA from each specimen was extracted and qPCR was exploited to detect miR-124a and miR-9 expression in the specimens. Statistical analysis was used to show the dynamic expressional changes of miR-124a and miR-9 in rat hippocampus at 1d, 7d, 14d and 28d post-SE during the process of epileptogenesis. ResultsCompared with normal rats, the expression level of miR-124a in rat hippocampus did not show a significant difference at 1d post-SE, but it had shown markedly differences at 7d, 14d and 28d post-SE(P < 0.05), with a declining trend. Compared with normal rats, the expression level of miR-9 had demonstrated significant differences at 1d, 7d, 14d and 28d post-SE(P < 0.05)with a generally increasing trend, although there was slight fluctuation of expressional up-regulation at 7d post-SE. ConclusionNeuronal growth and differentiation-associated miR-124a and miR-9 had shown dynamic changes of down-regulation or up-regulation in the process of epileptogenesis. It can be suspected that miR-124a and miR-9 take part in hippocampal neurogenesis post-SE and be involved in epileptogenesis process.
Mechanoresponsive microRNAs are a type of miRNAs which are sensitive or responsive to mechanical strain applied to them, their expression levels were changed after mechanical loading, thus affecting the expression levels of mRNA and proteins they regulated. Up to now, some mechanoresponsive miRNAs have been discovered in physiological or pathological tissues or organs. However, these discoveries are usually limited, and they are not able to guide clinical practice well. According to this situation, this paper summarizes research findings of mechanoresponsive miRNAs, and provides directions for clinical practice and further researches.
ObjectiveTo explore the influence of miRNA-155/PU.1 signaling pathway blockade on bone marrow-derived dendritic cells (DCs) maturation and immune function of rat small intestinal transplantation. MethodsThe DCs were induced by adherent culture.The critical transcription factor gene PU.1 was designed and PU.1 siRNA was synthe-sized.The DCs were transfected by liposome transfection and a pair of PU.1 siRNA was screened according to the high silencing efficiency.The expressions of DCs surface markers CD80, CD86, and MHC-Ⅱamong three groups (PU.1 silent group, negative control group, and control group) were analyzed by flow cytometry.The IL-10 and IL-12p70 secretion levels in the supernatant were tested by ELISA method.The allogeneic T lymphocyte proliferation was tested by mixed lymphocyte reaction.The transfected cells were intravenously injected into the recipient rat on day 7 before intestinal transplantation.The survival conditions as well as pathological changes were observed in each group recipients. Results①The surface molecules CD80, CD86, and MHC-Ⅱin the PU.1 silent group were (27.0±5.6)%, (23.6±4.8)%, and (36.8±6.8)%, respectively; versus (74.0±9.4)%, (76.5±8.7)%, and (87.8±11.3)% in the negative control group, respectively, which were significantly lower in former and showing an in creased trend (P < 0.05).②Compared with the negative control group, IL-10 secretion level was significantly increased (P < 0.05), IL-12p70 secretion level significantly decreased (P < 0.05) in the PU.1 silent group.③The proliferation of T lymphocytes in the PU.1 silent group was significantly lower than that in the negative control group (P < 0.05).④When the transfected DCs were injected into the intestinal transplantation rats on day 7 before operation, the survival time was (14.3±3.3) d, (7.8±1.5) d, and (8.0±2.5) d in the PU.1 silent group, negative control group, and control group, respectively, which in the PU.1 silent group were significantly longer than that in the other two groups (P < 0.05), and the graft pathology showed that there were mild intestinal tissue damage, lymphocyte infiltration or villus edema in the PU.1 silent group. ConclusionmiRNA-155/PU.1 signaling pathway blockade could reduce DCs maturation and induce receptor-specific immune tolerance, which are proved both in vivo and in vitro.
ObjectiveTo investigate the effect of Smad4 on the fibrosis of tendon derived fibroblasts (TDFs) induced by transforming growth factor β1(TGF-β1) by targeted regulation of miRNA219-5P (miR219-5P). MethodsThe tendons donated by the volunteers were harvested to isolate and culture TDFs. The 3rd generation cells were used for experiment. Chemically synthesized miR219-5P mimics, miR219-5P inhibitor, and negative control sequences were transfected into TDFs. The gene expression of miR219-5P in TDFs was detected by real-time PCR, and the protein expression of Smad4 in TDFs was detected by Western blot at 48 hours after transfection. The combining sites of miR219-5P and Smad4 in 3'UTR district were predicted by informatics software. Wild type and mutant type reporter gene expression vectors were constructed and then targeted verification was carried out by the luciferase reporter gene test. Transfected TDFs were then induced by TGF-β1. The proliferation activity of the cells were measured by the cell counting kit 8 after culturing for 24, 48, and 72 hours. The expressions of fibrosis related proteins in TDFs were detected by Western blot at 72 hours. ResultsAfter TDFs were transfected by miR219-5P mimics, miR219-5P expression was significantly up-regulated, but the expressions of Smad4 was decreased subsequently (P<0.05). Intracellular expression of miR219-5P was inhibited by miR219-5P mimics inhibitor, however, the protein expression of Smad4 was significantly increased (P<0.05). Luciferase reporter gene test showed that luciferase activities were significantly decreased in pGL3-WT-Smad4+mimics group, but were significantly increased in pGL3-WT-Smad4+inhibitor group when compared with pGL3-WT-Smad4 transfected group (P<0.05), but no significant difference was found between GL3-MT-Smad4+mimics and pGL3-MT-Smad4+inhibitor groups (P>0.05). Cell proliferation and the fibrosis related proteins were increased in TGF-β1 induced TDFs, however, decreased in TGF-β1 induced TDFs after transfected by miR219-5P inhibitor (P<0.01). ConclusionmiR219-5P can significantly inhibit fibrosis of TDFs induced by TGF-β1 by down-regulating Smad4 expression.
ObjectiveTo investigate the expression of miRNA-1 in denervated skeletal muscle at different periods, and to explore effects of passive movement on the expression of miRNA-1 and differentiation of myoblasts in denervation-induced skeletal muscle atrophy in rats. MethodsTwenty-seven Sprague Dawley rats, weighing (200±10) g, were randomly divided into sham-operated group (group A, n=3), denervated group (group B, n=12), and passive movement group (group C, n=12). After the right sciatic nerve was exposed and dissociated, the sciatic nerve of 1 cm in length was removed in groups B and C; resection was not performed in group A. At 1 day after operation, passive flexion and extension movement was performed on the right hind limb in group C. At 6 hours in group A and at 3, 7, 14, and 28 days in groups B and C, 3 rats were sacrificed to measure the wet weight ratio of gastrocnemius muscle, to observe the diameter of the gastrocnemius muscle cell and evaluate the muscle atrophy by HE staining; RT-PCR was used to detect the mRNA expression of miRNA-1 and myocyte differentiation factor (MyoD), and immunohistochemistry to determine the protein expression of MyoD. ResultsAtrophy in various degrees was observed in denervated gastrocnemius muscle of groups B and C. The muscle fiber arranged in disorder and the diameter of the muscle cells decreased gradually with the time, without normal structure and morphology. The wet weight ratio and the cell diameter of the gastrocnemius in groups B and C were significantly less than those in group A (P<0.05); the wet weight ratio at 7, 14, 28 days and the cell diameter at 7, 14 days of group B were significantly greater than those of group A (P<0.05). The expressions of miRNA-1 and MyoD mRNA gradually increased with time in groups B and C, but were significantly less than those of group A at each time point (P<0.05). At 7, 14, and 28 days after operation, the expressions of miRNA-1 and MyoD mRNA in group C were significantly higher than those in group B (P<0.05). Immunohistochemical staining showed positive expression of MyoD in groups A, B, and C at each time point, but higher expression was observed in groups B and C than group A; the expression increased with time in groups B and C, and it was significantly higher in group C than group B. The correlation analysis results showed that the overall change trend of miRNA-1 and MyoD had no relation with the gastrocnemius wet weight ratio at 3 and 7 days (P>0.05), and had positive correlation at 14 and 28 days (P<0.05); positive correlation was found between the relative expression of MyoD and miRNA-1 mRNA (P<0.05). ConclusionPassive movement can prevent amyotrophy by increasing the expression of miRNA-1 and promoting the differentiation of myoblasts.
Colorectal cancer is one of the most common malignant diseases that threatens human being's health. With researches on microRNAs (miRNAs) getting deeper and wider, more evidences revealed that a great many of miRNAs have been involved in the development of colorectal cancer and have the potential to become the biomarker for early diagnosis, prediction of prognosis and recurrence of colorectal cancer. MiRNA-143/miRNA-145 are significantly reduced in several cancers, including colorectal cancer, showing an antitumorigenic activity. In the present article, we make a brief review on the advances in the researches on miRNA-143/miRNA-145 and colorectal cancer to provide guidance for further explorations of the mechanism and target therapy of this disease.
Objective To explore the diagnostic value of miRNAs for pancreatic cancer. Methods PubMed, Scopus, Web of Science, CBM, CNKI, WanFang Data and VIP databases were retrieved from inception to December 31st 2015, to collect diagnostic accuracy studies about miRNAs for pancreatic cancer. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies by using the QUADAS-2 tool. Then meta-analysis was performed using MetaDiSc 1.4 and Stata 12.0 softwares. Results A total of 40 articles involving 109 studies were included. The results of meta-analysis showed that the pooled Sen, Spe, +LR, –LR and DOR were 0.81 (95%CI 0.80 to 0.82), 0.77 (95%CI 0.75 to 0.78), 3.15 (95%CI 2.78 to 3.58), 0.27 (95%CI 0.24 to 0.31) and 13.58 (95%CI 10.89 to 16.94), respectively. The AUC of SROC was 0.86 (95%CI 0.84 to 0.88). Subgroups analysis showed that: as to diagnostic accuracy, Caucasian was superior to Asian (AUC=0.89vs. 0.84); multiple-miRNAs profiling-based assays was superior to single miRNA assays (AUC=0.91vs. 0.84). Conclusion Current evidence suggests that miRNA has potential diagnostic value for pancreatic cancer, particularly using multiple miRNAs. Due to limited quality of the included studies, more high quality studies are needed to verify the above conclusion.
Objective Hepatitis B virus X (HBx) protein is involved in the initiation and progression of hepatocellular carcinoma (HCC) by regulating the host protein-coding genes. Herein, we want to explore whether HBx protein can alter the expression of microRNAs (miRNAs) to promote proliferation and transformation in malignant hepatocytesin vitro. Methods MiRNA microarray and quantitative reverse-transcription polymerase chain reactions (qRT-PCRs) were performed to identify miRNAs that were differentially regulated by HBx protein in HCC cells. Protein and mRNA expression analyses, cell cycle and apoptosis analyses, and luciferase reporter assays were performed to delineate the consequences of miR-16 family repression in HepG2 cells. Results HBx protein induced widespread deregulation of miRNAs in HepG2 cells, and the downregulation of the miR-16 family was reproducible in HepG2, SK-HEP-1, and Huh7 cells. CCND1, a target gene of the miR-16 family, was derepressed by HBx protein in HepG2 cells. C-myc mediated the HBx-induced repression of miR-15a/16 in HepG2 cells. Ectopically expressed miR-15a/16 suppressed the proliferation, clonogenicity, and anchorage-independent growth of HBx-expressing HepG2 cells by arresting them in the G1 phase and inducing apoptosis, whereas reduced expression of miR-16 accelerated the growth and cell-cycle progression of HepG2 cells. Conclusions HBx protein altered thein vitro expression of miRNAs in host malignant hepatocytes, particularly downregulating the miR-16 family. Repression of miR-15a/16 is c-myc mediated and is required for the HBx-induced transformation of HepG2 cellsin vitro. Therefore, miR-16 family may serve as a therapeutic target for hepatitis B virus (HBV)-associated HCC.
Objective To review the research progress of miRNA regulation in the differentiation of adipose-derived stem cells (ADSCs). Methods The recent literature associated with miRNAs and differentiation of ADSCs was reviewed. The regulatory mechanism was analyzed in detail and summarized. Results The results indicate that the expression of miRNAs changes during differentiation of ADSCs. In addition, miRNAs regulate the differentiation of ADSCs into adipocytes, osteoblasts, chondrocytes, neurons, and hepatocytes by regulating the signaling pathways involved in cell differentiation. Conclusion Through controlling the differentiation of ADSCs by miRNAs, the suitable seed cell for tissue engineering can be established. The review will provide a theoretical basis for molecular targeted therapy and stem cell therapy in clinic.
Objective To detect expression of miR-483-5p in surem of patients with hepatocellular carcinoma (HCC) and investigate it’s clinical significance for diagnosis of HCC. Methods The rerum samples of 112 patients with HCC (HCC group), 85 patients with chronic viral hepatitis B (CHB group), and 56 healthy people for physical examination (healthy control group) were collected from January 2010 to January 2012 in the First Hospital of Lanzhou University. According to the results of preliminary chip detection of miRCURY LNATM miRNA, the real-time fluorescent quantitative PCR was adopted to quantitate the serum levels of miR-483-5p and miR-500a and the routine electrochemical method was used to detect the serum alpha fetoprotein (AFP) in every group. The receiver operating characteristic (ROC) curve was utilized to analyze the diagnostic values of serum miR-483-5p, miR-500a, and AFP for the HCC. Results The serum levels of miR-483-5p and miR-500a in the HCC group were significantly higher than those of the CHB and healthy control groups (both P<0.000 1), which had no significant differences between the CHB group and the healthy control group (P>0.05). The serum miR-483-5p level of the HCC patient decreased markedly at the postoperative 30 d (P<0.000 1) as compared with the preoperative level. The area under the ROC curve (AUC) of miR-483-5p, miR-500a, AFP, or miR-483-5p in combination with AFP for the diagnosis of the HCC was 0.74 (cutoff value=2.842, sensitivity=74% and specificity=66%), 0.66 (cutoff value=1.830, sensitivity=74% and specificity=51%), 0.81 (cutoff value=20 μg/L, sensitivity=78% and specificity=70%), and 0.92 (cutoff value=3.78, sensitivity=81% and specificity=83%), respectively. The AUC values of miR-483-5p in the diagnosis of the HCC patients with positive AFP (AFP>20 μg/L) and negative AFP (0–20 μg/L) were 0.78 and 0.83, respectively. Conclusions Serum miR-483-5p highly expresses in HCC, which has a certain accuracy in diagnosis of HCC, it combined with AFP could further increase its diagnostic value. Serum miR-483-5p might play an important supplemental role in diagnosis of HCC patient with negative AFP.