Microarray analysis reveals the changes of circular RNA expression and molecular mechanism in acute lung injury mouse model

Acute lung injury (ALI) is a severe disease with sudden onset, rapid progression, poor treatment response, and high mortality. An increasing number of studies had found that circular RNAs (circRNAs) has significant functions in various diseases, while the role of circRNAs in ALI is not yet clear. The purpose of this study was to find circRNAs related to ALI and their mechanism of action. Expression profiles of lung circRNAs and messenger RNAs (mRNAs) were analyzed by microarray in the ALI mice models and healthy controlled mice. Differentially expressed RNAs were identified, function and pathways were analyzed by bioinformatics analysis. Moreover, the results of the microarray were verified by real-time PCR. We identified 2262 differentially expressed mRNAs and 581 circRNAs between ALI mice and control. Validation of candidate circRNAs by real-time PCR indicates that the majority of circRNAs identified by microarray are reliable and worthy of further study. ALI induced circRNAs primarily function in the metabolic regulatory process. Moreover, differentially expressed circRNAs were mainly involved in signaling pathways of mitogen-activated protein kinases, focal adhesion, FoxO, neurotrophin, and Wnt. In addition, a competitive endogenous RNA network was constructed to further interpret the molecular mechanism of ALI. This study observed significantly changed circRNAs profiles in LPS-induced mouse model and revealed a potential role of circRNAs in ALI.     

Effect of microRNA-27a-5p on apoptosis and inflammatory response of pancreatic acinar cells in acute pancreatitis by targeting PTEN

To investigate the apoptosis and inflammatory response of microRNA-27a-5p (miR-27a-5p) in pancreatic acinar cells of acute pancreatitis (AP) and its related mechanisms. Rat pancreatic acinar cell line AR42J was treated with caerulein (10nmol/L) to construct an acute pancreatitis cell model. Quantitative real-time polymerase chain reaction was performed to measure the expression of miR-27a-5p; The miR-27a-5p mimic was transfected into cell, and the apoptosis rate of the cells was detected by flow cytometry; The levels of TNF-α, IL-1, and IL-6 in the culture supernatant were determined by enzyme-linked immunosorbent assay; TargetScans database predicted and dual luciferase reporter gene assay verified the relationship between miR-27a-5p and the phosphatase and tensin homolog deleted on chromosome 10 (PTEN); The recovery experiment explored the apoptosis and the effects of inflammatory responses. The expression of miR-27a-5p decreased gradually (P < 0.05) and the expression of PTEN increased gradually (P < 0.05) with the prolongation of acting time. Upregulation of miR-27a-5p significantly promoted cell apoptosis (P < 0.05) and inhibited inflammatory response (P < 0.05); The TargetScans database predicted that the 3'UTR of PTEN contains a base complementary to the miR-27a-5p seed region. Cotransfection of wild-type vector (PTEN-WT) with miR-27a-5p mimic or miR-27a-5p inhibitor significantly affected the relative activity of luciferase (P < 0.05), and no significant impact was observed in mutant PTEN-MUT. Compared with miR-27a-5p + pcDNA group, transfection of miR-27a-5p mimic and pcDNA-PTEN significantly increased the expression of PTEN (P < 0.05), decreased the apoptotic rate (P < 0.05), and increased the inflammatory response (P < 0.05). miR-27a-5p induced apoptosis and inhibited the inflammatory response of pancreatic acinar cells in AP by targeting PTEN.     

The discovery of a novel eight-mRNA-lncRNA signature predicting survival of hepatocellular carcinoma patients

Increasing evidence indicates that the expressions of messenger RNAs (mRNAs) and long non-coding RNAs (lncRNAs) undergo a frequent and aberrant change in carcinogenesis and cancer development. But some research was carried out on mRNA-lncRNA signatures for prediction of hepatocellular carcinoma (HCC) prognosis. We aimed to establish an mRNA-lncRNA signature to improve the ability to predict HCC patients’ survival. The subjects from the cancer genome atlas (TCGA) data set were randomly divided into two parts: training data set (n = 246) and testing data set (n = 124). Using computational methods, we selected eight gene signatures (five mRNAs and three lncRNAs) to generate the risk score model, which were significantly correlated with overall survival of patients with HCC in both training and testing data set. The signature had the ability to classify the patients in training data set into a high-risk group and low-risk group with significantly different overall survival (hazard ratio = 4.157, 95% confidence interval = 2.648-6.526, P < 0.001). The prognostic value was further validated in testing data set and the entire data set. Further analysis revealed that this signature was independent of tumor stage. In addition, Gene Set Enrichment Analysis suggested that high risk score group was associated with cell proliferation and division related pathways. Finally, we developed a well-performed nomogram integrating the prognostic signature and other clinical information to predict 3- and 5-year overall survival. In conclusion, the prognostic mRNAs and lncRNAs identified in our study indicate their potential role in HCC biogenesis. The risk score model based on the mRNA-lncRNA may be an efficient classification tool to evaluate the prognosis of patients’ with HCC.     

Role of lactadherin in intestinal barrier integrity in experimental neonatal necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is one of the most widespread and devastating gastrointestinal diseases in neonates. Destruction of the intestinal barrier is the main underlying cause of NEC. The aim of this study was to determine the role of lactadherin in preventing NEC in a neonatal rat model and investigate the molecular mechanism of lactadherin-mediated protection of the intestinal barrier. Neonatal rats were divided into three groups: dam feeding (DF), NEC (NEC), and NEC supplemented with 10 μg/(g·day) recombinant human lactadherin (NEC+L). Intestinal permeability, tissue damage, and cell junction protein expression and localization were evaluated. We found that lactadherin reduced weight loss caused by NEC, reduced the incidence of NEC from 100% to 46.7%, and reduced the mean histological score for tissue damage to 1.40 compared with 2.53 in the NEC group. Intestinal permeability of lactadherin-treated rats was significantly reduced when compared with that of the NEC group. In addition, the expression levels of JAM-A, claudin 3, and E-calcium in the ileum of NEC group animals increased compared with those in the ileum of DF group animals, and these levels decreased in the NEC+L group. Lactadherin changed the localization of claudin 3, occludin, and E-cadherin in epithelial cells. The mechanism underlying lactadherin-mediated protection of the intestinal barrier might be restoring the correct expression levels and localization of tight junction and adherent junction proteins. These findings suggest a new candidate agent for the prevention of NEC in newborns.     

Overexpression of the lncRNA FER1L4 inhibits paclitaxel tolerance of ovarian cancer cells via the regulation of the MAPK signaling pathway

To determine how the lncRNA FER1L4 in ovarian cancer cells influences paclitaxel (PTX) resistance, we examined the expression level of FER1L4 in human ovarian epithelial cell lines IOSE80 and HOSEpiC and human ovarian cancer cell lines OVCAR-3, Caov-3, and SKOV3 through RNA isolation and quantitative polymerase chain reaction (qRT-PCR). SKOV3 cell lines were treated with PTX. The cell survival rate and apoptosis rate of SKOV3 and SKOV3-PR at different PTX dose levels were evaluated. Next, qRT-PCR was performed to detect the expression of FER1L4 in SKOV3 and SKOV3-PR cell lines. SKOV3-PR cell lines were transfected with pcDNA3.1 as the control group (SKOV3-PR/pcDNA3.1) or pcDNA3.1-FER1L4 to upregulate the expression level of FER1L4 (SKOV3-PR/pcDNA3.1-FER1L4). The level of cell survival, apoptosis, and colony formation were compared between the two groups using MTT, flow cytometry analysis, and colony formation assay. To reveal the molecular mechanism, we measured the relative protein phosphorylation level of ERK and MAPK in SKOV3, SKOV3-PR, SKOV3-PR/pcDNA3.1, and SKOV3-PR/pcDNA3.1-FER1L4 groups using an enzyme-linked immunosorbent assay. The effects of SB203580 (a p38 MAPK inhibitor) on PTX were also investigated to reveal the function of the MAPK pathway on the PTX tolerance of SKOV3. In comparison with normal ovarian epithelial cells, FER1L4 was downregulated. The FER1L4 level was decreased in human ovarian cancer cells with drug resistance than in common ovarian cancer cells. The upregulation of FER1L4 could promote the PTX sensitivity of ovarian cancer cells. The increased level of FER1L4 could suppress the PTX resistance of ovarian cancer cells through the inhibition of the MAPK signaling pathway.     

MNX1-AS1 is a novel biomarker for predicting clinical progression and poor prognosis in lung adenocarcinoma

Motor neuron and pancreas homeobox 1-antisense RNA1 (MNX1-AS1) is a novel long noncoding RNA and has been suggested to be overexpressed in human ovarian cancer and glioma. The role of MNX1-AS1 in lung cancer was still unknown. In our study, we observed levels of MNX1-AS1 expression through analyzing The Cancer Genome Atlas and found MNX1-AS1 expression was highly expressed in lung adenocarcinoma tissues compared with normal lung tissues, but there was no statistical difference between lung squamous cell carcinoma tissues and normal lung tissues. Furthermore, we conducted quantitative real-time polymerase chain reaction, and confirmed that the expression of MNX1-AS1 was definitely higher in lung adenocarcinoma tissue samples, but not in lung squamous cell carcinoma tissue samples. In addition, high MNX1-AS1 expression was found to be associated with the low differentiated degree, advanced clinical stage, big tumor size, lymph node metastasis, and distant metastasis in lung adenocarcinoma patients. High expression of MNX1-AS1 was negatively correlated with overall survival time and served as an independent unfavorable prognostic factor in patients with lung adenocarcinoma. The in vitro functional studies suggested that suppression of MNX1-AS1 inhibited lung adenocarcinoma cell proliferation and migration, and promoted apoptosis. In conclusion, MNX1-AS1 is overexpressed in lung adenocarcinoma, and associated with clinical progression and poor prognosis.     

Fibroblast growth factor 21 protects against pathological cardiac remodeling by modulating galectin-3 expression

Background/Aims: Fibroblast growth factor 21 (FGF21) plays a protective role in ischemia/reperfusion induced cardiac injury. However, the exact molecular mechanism of FGF21 action remains unclear. This study was designed the protective effect of FGF21 on the heart and its mechanism. Method: Adenovirus vector expressing FGF21 or control β-galactosidase was injected into the myocardium of mice. Myocardial injury was observed by tissue staining and immunohistochemical staining. The expression level of caspases-3 and galectin-3 in myocardial cells were observed by immunoblotting. Then, hypoxia-induced cell model was established. Small interfering RNA (SiRNA) and plasmid were transfected into H9c2 using Lipofectamine 2000 reagent (Invitrogen). The expression levels of galectin-3, ECM and cystatin-3 in cells were observed by immunoblotting, and the relationship between fibroblast growth factor 21 and galectin-3 was analyzed. Result: Cell test in vitro showed that FGF21 could inhibit apoptosis and decrease the expression of ECM (ColIaI, fibronectin, and alpha-SMA) under hypoxia. Western blot data showed that hypoxia-induced cell damage increased galectin-3 levels, while FGF21 decreased galactose lectin-3 levels. In addition, inhibition of galactose agglutinin-3 expression by siRNA enhanced the cardioprotective effect of FGF21, while overexpression of galectin-3 reduced the cardioprotective effect of fibroblast growth factor 21. Conclusion: FGF21 may be a novel therapy for hypoxia-induced cardiac injury by regulating the expression of galectin-3.