PRDX6 regulates the H2O2 and blue light-induced APRE-19 cell apoptosis via down-regulating and interacting with RARA.

Hereditary retinal disease (HRD) is the primary retinal degeneration that leads to severe visual impairments and refractory blindness, and the therapy of HRD was most important in ophthalmology. The apoptosis of retinal cells plays important roles in HRD progression. Therefore, in this study, we explore the mechanism of H2O2 and blue light-induced apoptosis of ARPE-19 cells. Co-immunoprecipitation (Co-IP) is employed to test the interactions between proteins, and western blotting is used to detect the protein levels. Apoptosis is analyzed by Flow cytometry. Our results found that PRDX6 could interact with RARA in ARPE-19 cells, and H2O2 and blue light could significantly reduce the RARA protein expression, and also could inhibit the interaction between PRDX6 and RARA. Using a rescue experiment, we further elucidated that H2O2 and blue light reduced the RARA expression via down-regulating PRDX6. And H2O2 and blue light induced the ARPE-19 cell apoptosis via decreasing the expression of PRDX6. Our results suggested that the interaction between PRDX6 and RARA played important roles in the apoptosis of ARPE-19 cells.

Identification of a novel four-lncRNA signature as a prognostic indicator in cirrhotic hepatocellular carcinoma.

BACKGROUND: Many studies have shown that long noncoding RNAs (lncRNA) are closely associated with the occurrence and development of various tumors and have the potential to be prognostic markers. Moreover, cirrhosis is an important prognostic risk factors in patients with liver cancer. Some studies have reported that lncRNA-related prognostic models have been used to predict overall survival (OS) and recurrence-free survival (RFS) in patients with hepatocellular carcinoma (HCC). However, no one has constructed a prognostic lncRNA model only in patients with cirrhotic HCC. Thus, it is necessary to screen novel potential lncRNA markers for improve the prognosis of cirrhotic HCC patients. METHODS: The probe expression profile dataset (GSE14520-GPL3921) from the Gene Expression Omnibus (GEO), which included 204 cirrhotic HCC samples, was reannotated and the lncRNA and mRNA expression dataset was obtained. The patients were randomly assigned to either the training set (n = 103) and testing set (n = 100). Univariate cox regression and the least absolute shrinkage and selection operator (LASSO) model were applied to screen lncRNAs linked to the OS of cirrhotic HCC in the training set. The lncRNAs having significant correlation with OS were then selected and the multivariate Cox regression model was implemented to construct the prognostic score model. Whether or not this model was related to RFS in the training set was simultaneously determined. The testing set was used to validate the lncRNA risk score model. A risk score based on the lncRNA signature was used for stratified analysis of different clinical features to test their prognostic performance. The prognostic lncRNA-related protein genes were identified by the co-expression matrix of lncRNA-mRNA, and the function of these lncRNAs was predicted through the enrichment of these co-expression genes. RESULTS: The signature consisted of four lncRNAs:AC093797.1,POLR2J4,AL121748.1 and AL162231.4. The risk model was closely correlated with the OS of cirrhotic HCC in the training cohort, with a hazard ratio (HR) of 3.650 (95% CI [1.761-7.566]) and log-rank P value of 0.0002. Moreover, this model also showed favorable prognostic significance for RFS in the training set (HR: 2.392, 95% CI [1.374-4.164], log-rank P = 0.0015). The predictive performance of the four-lncRNA model for OS and RFS was verified in the testing set. Furthermore, the results of stratified analysis revealed that the four-lncRNA model was an independent factor in the prediction of OS and RFS of patients with clinical characteristics such as TNM (Tumor, Node, Metastasis system) stages I-II, Barcelona Clinic Liver Cancer (BCLC) stages 0-A, and solitary tumors in both the training set and testing set. The results of functional prediction showed that four lncRNAs may be potentially involve in multiple metabolic processes, such as amino acid, lipid, and glucose metabolism in cirrhotic HCC.

Umbilical cord-derived mesenchymal stem cells inhibit growth and promote apoptosis of HepG2 cells.

Hepatocellular carcinoma is the fifth most common type of cancer worldwide and remains difficult to treat. The aim of this study was to investigate the effects of mesenchymal stem cells (MSCs) derived from the umbilical cord (UC­MSCs) on HepG2 hepatocellular carcinoma cells. UC­MSCs were co­cultured with HepG2 cells and biomarkers of UC­MSCs were analyzed by flow cytometry. mRNA and protein expression of genes were determined by reverse transcription­polymerase chain reaction and flow cytometry, respectively. Passage three and seven UC­MSCs expressed CD29, CD44, CD90 and CD105, whereas CD34 and CD45 were absent on these cells. Co­culture with UC­MSCs inhibited proliferation and promoted apoptosis of HepG2 cells in a time­dependent manner. The initial seeding density of UC­MSCs also influenced the proliferation and apoptosis of HepG2 cells, with an increased number of UC­MSCs causing enhanced proliferation inhibition and cell apoptosis. Co­culture with UC­MSCs downregulated mRNA and protein expression of α­fetoprotein (AFP), Bcl­2 and Survivin in HepG2 cells. Thus, UC­MSCs may inhibit growth and promote apoptosis of HepG2 cells through downregulation of AFP, Bcl­2 and Survivin. US-MSCs may be used as a novel therapy for treating hepatocellular carcinoma in the future.

PRDX6 Protects ARPE-19 Cells from Oxidative Damage via PI3K/AKT Signaling.

BACKGROUND/AIMS: Oxidative stress that damages cells of the retinal pigment epithelium (RPE) can cause the development of hereditary retinal disease (HRD). PRDX6, which is a member of the PRDX family, is essential for removing metabolic free radicals from the body. However, the effect of PRDX6 on oxidative stress in HRD remains unknown. In this study, we sought to investigate the role of PRDX6 in oxidative stress-induced HRD in ARPE-19 cells and the molecular mechanism involved. METHODS: ARPE-19 cells were used in the current study. Intracellular ROS levels were determined by flow cytometry. Lipid peroxidation was measured using a commercial MDA assay kit. Cellular variability was determined by MTT assay. Apoptosis was determined using an Annexin V-FITC Apoptosis Detection Kit. mRNA and protein expression levels were detected by real-time PCR and western blot analysis, respectively. RESULTS: We found that H2O2 and blue light could induce significant oxidative stress damage and cell death in ARPE-19 cells. Furthermore, we found that PRDX6 levels significantly decreased after H2O2 treatment. PRDX6 overexpression protected ARPE-19 cells from H2O2- and blue light-induced oxidative damage, while PRDX6 knockdown enhanced oxidative damage in these cells. Mechanistically, we found that PRDX6 prevented oxidative damage and promoted ARPE-19 cell survival through the PI3K/AKT signaling pathway. CONCLUSIONS: Collectively, these results suggest that PRDX6 protects ARPE-19 cells from H2O2-induced oxidative stress and apoptosis and that this protection is mediated at least partially through the PI3K/AKT pathway.

Urine and serum metabolomic profiling reveals that bile acids and carnitine may be potential biomarkers of primary biliary cirrhosis.

In order to provide non-invasive, reliable and sensitive laboratory parameters for the diagnosis of primary biliary cirrhosis (PBC), metabolic technology of ultraperformance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF MS) was used to compare small molecule metabolites in blood and urine from patients with PBC and healthy controls. We then screened for bio-markers in the blood and urine of the patients with PBC. Data were processed by Bruker ProfileAnalysis metabonomic software and imported to SIMCA-P software, which utilized principal component analysis (PCA) to create models of patients with PBC and healthy controls. In total, 18 urinary markers were found and the levels of 11 of these urinary markers were elevated in the patients with PBC, whereas the levels of the remaining 7 markers were lower in the PBC group compared to the control group. We also identified 20 blood-based biomarkers in the patients with PBC and the levels of 9 of these markers were higher in the PBC group, whereas the levels of the remaining 11 markers were lower in the patients with PBC compared to the controls. Among these biomarkers, the levels of bile acids increased with the progression of PBC, while the levels of carnitines, such as propionyl carnitine and butyryl carnitine, decreased with the progression of PBC. In conclusion, the findings of the present study suggest that the circulating levels of bile acids and carnitine are differentially altered in patients with PBC.