Role of PPAR-related genes in chronic heart failure: evidence from large populations

BACKGROUND

The role of PPAR signaling and its associated genes in the pathogenesis and progression of chronic heart failure (CHF) remains elusive.

METHODS

We accessed the gene expression profile and relevant baseline information of CHF samples from the Gene Expression Omnibus (GEO) database, specifically from the GSE57338 project.

RESULTS

From GSE57338 project, we derived the expression value of 126 PPAR-related genes. A protein-protein interaction network was then established to illustrate potential protein interactions. ClueGO analysis results revealed that these genes predominantly participate in functions such as export across plasma membrane, regulation of lipid metabolic process, fatty acid metabolism, circulatory system vascular processes, alcohol metabolism, triglyceride metabolism and regulation of lipid localization and response to nutrient. Using the cytohubba plug-in in Cytoscape, we pinpointed ACADM, PPARG and CPT2 as potential central molecules in HF pathogenesis and progression. Subsequent Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis delved into the potential biological role of these three genes in CHF. Immune infiltration analysis suggested that the infiltration level of neutrophils and M2 macrophages might be notably influenced by these genes, thereby playing a role in the CHF mechanism.

CONCLUSIONS

Our research provides a comprehensive insight into the significance of PPAR associated genes in CHF development. Notably, the genes ACADM, PPARG and CPT2 emerged as potential targets for clinical interventions.

KCNH2 mutation c.3099_3112del causes congenital long QT syndrome type 2 with gender differences

INTRODUCTION

Long QT Syndrome (LQTS) is an inherited disease with an abnormal electrical conduction system in the heart that can cause sudden death as a result of QT prolongation. LQT2 is the second most common subtype of LQTS caused by loss of function mutations in the potassium voltage-gated channel subfamily H member 2 (KCNH2) gene. Although more than 900 mutations are associated with the LQTS, many of these mutations are not validated or characterized.

METHODS AND RESULTS

Sequencing analyses of genomic DNA of a family with LQT2 identified a putative mutation. i.e., KCNH2(NM_000238.3): c.3099_3112del, in KCNH2 gene which appeared to be a definite pathogenic mutation. The family pedigree information showed a gender difference in clinical features and T-wave morphology between male and female patients. The female with mutation exhibited recurring ventricular arrhythmia and syncope, while two male carriers did not show any symptoms. In addition, T-wave in females was much flatter than in males. The female proband showed a positive reaction to the lidocaine test. Lidocaine injection almost completely blocked ventricular arrhythmia and shortened the QT interval by ≥30 ms. Treatment with propranolol, mexiletine, and implantation of cardioverter-defibrillators prevented the sustained ventricular tachycardia, ventricular fibrillation, and syncope, as assessed by a 3-year follow-up evaluation.

CONCLUSIONS

A putative mutation c.3099_3112del in the KCNH2 gene causes LQT2 syndrome, and the pathogenic mutation mainly causes symptoms in female progeny.

A novel PRRX1 loss-of-function variation contributing to familial atrial fibrillation and congenital patent ductus arteriosus

Atrial fibrillation (AF) represents the most common type of sustained cardiac arrhythmia in humans and confers a significantly increased risk for thromboembolic stroke, congestive heart failure and premature death. Aggregating evidence emphasizes the predominant genetic defects underpinning AF and an increasing number of deleterious variations in more than 50 genes have been involved in the pathogenesis of AF. Nevertheless, the genetic basis underlying AF remains incompletely understood. In the current research, by whole-exome sequencing and Sanger sequencing analysis in a family with autosomal-dominant AF and congenital patent ductus arteriosus (PDA), a novel heterozygous variation in the PRRX1 gene encoding a homeobox transcription factor critical for cardiovascular development, NM_022716.4:c.373G>T;p.(Glu125^*), was identified to be in co-segregation with AF and PDA in the whole family. The truncating variation was not detected in 306 unrelated healthy individuals employed as controls. Quantitative biological measurements with a reporter gene analysis system revealed that the Glu125^*-mutant PRRX1 protein failed to transactivate its downstream target genes SHOX2 and ISL1, two genes that have been causally linked to AF. Conclusively, the present study firstly links PRRX1 loss-of-function variation to AF and PDA, suggesting that AF and PDA share a common abnormal developmental basis in a proportion of cases.

PRRX1 Loss-of-Function Mutations Underlying Familial Atrial Fibrillation

Background

Atrial fibrillation (AF) is the most common form of clinical cardiac dysrhythmia responsible for thromboembolic cerebral stroke, congestive heart failure, and death. Aggregating evidence highlights the strong genetic basis of AF. Nevertheless, AF is of pronounced genetic heterogeneity, and in an overwhelming majority of patients, the genetic determinants underpinning AF remain elusive.

Methods and Results

By genome‐wide screening with polymorphic microsatellite markers and linkage analysis in a 4‐generation Chinese family affected with autosomal‐dominant AF, a novel locus for AF was mapped to chromosome 1q24.2–q25.1, a 3.20‐cM (≈4.19 Mbp) interval between markers D1S2851 and D1S218, with the greatest 2‐point logarithm of odds score of 4.8165 for the marker D1S452 at recombination fraction=0.00. Whole‐exome sequencing and bioinformatics analyses showed that within the mapping region, only the mutation in the paired related homeobox 1 (PRRX1) gene, NM_022716.4:c.319C>T;(p.Gln107*), cosegregated with AF in the family. In addition, sequencing analyses of PRRX1 in another cohort of 225 unrelated patients with AF revealed a new mutation, NM_022716.4:c.437G>T; (p.Arg146Ile), in a patient. The 2 mutations were absent in 908 control subjects. Biological analyses in HeLa cells demonstrated that the 2 mutants had significantly diminished transactivation on the target genes ISL1 and SHOX2 and markedly decreased ability to bind the promoters of ISL1 and SHOX2 (2 genes causally linked to AF), although with normal intracellular distribution.

Conclusions

This study first indicates that PRRX1 loss‐of‐function mutations predispose to AF, which provides novel insight into the molecular pathogenesis underpinning AF, implying potential implications for precisive prophylaxis and management of AF.

RNA sequencing profiling reveals key mRNAs and long noncoding RNAs in atrial fibrillation

Long noncoding RNAs (lncRNAs) are an emerging class of RNA species that could participate in some critical pathways and disease pathogenesis. However, the underlying molecular mechanism of lncRNAs in atrial fibrillation (AF) is still not fully understood. In the present study, we analyzed RNA-seq data of paired left and right atrial appendages from five patients with AF and other five patients without AF. Based on the gene expression profiles of 20 samples, we found that a majority of genes were aberrantly expressed in both left and right atrial appendages of patients with AF. Similarly, the dysregulated pathways in the left and right atrial appendages of patients with AF also bore a close resemblance. Moreover, we predicted regulatory lncRNAs that regulated the expression of adjacent protein-coding genes (PCGs) or interacted with proteins. We identified that NPPA and its antisense RNA NPPA-AS1 may participate in the pathogenesis of AF by regulating the muscle contraction. We also identified that RP11 - 99E15.2 and RP3 - 523K23.2 could interact with proteins ITGB3 and HSF2, respectively. RP11 - 99E15.2 and RP3 - 523K23.2 may participate in the pathogenesis of AF via regulating the extracellular matrix binding and the transcription of HSF2 target genes, respectively. The close association of the lncRNA-interacting proteins with AF further demonstrated that these two lncRNAs were also associated with AF. In conclusion, we have identified key regulatory lncRNAs implicated in AF, which not only improves our understanding of the lncRNA-related molecular mechanism underlying AF but also provides computationally predicted regulatory lncRNAs for AF researchers.

Identification of six miRNAs serving as predictive biomarkers in coronary artery disease

Coronary artery disease (CAD) is quite a common disease with high risk. It was reported that microRNAs (miRNAs) had significant effect on the occurrence of CAD. The previously published results are inconsistent due to the parameters, such as sequencing platform, samples selection, and the filter conditions. Here we aimed to explore the critical miRNAs in the occurrence of CAD, which may function as the potential biomarkers. A total of 12 representative datasets of miRNAs related to the occurrence of miRNAs were finally selected, and the critical miRNAs were determined by the comparison of the overlap relations. TargetScan software was used to predict the target genes of these critical miRNAs. Besides, DAVID and Tfacts dataset were used to analyze the functional enrichment and the transcriptional factors analysis. At last, a total of six signature miRNAs were identified, among which five were significantly upregulated and one was downregulated. The target gene of upregulated miRNAs was mostly enriched in the process of RNA Polymerase II promoter and the transcription of DNA template, whereas the target genes of downregulated miRNAs were mostly enriched in the regulation of transcription, DNA-templated. Besides, the result of the transcriptional factor analysis showed that there were 43 factors coexisting in two kinds of target genes. In summary, six critical miRNAs, as well as the corresponding target genes and transcriptional factors, were identified in the occurrence of CAD by bioinformatics analysis. These identified miRNAs may function as potential biomarkers in the clinical management of CAD.

MicroRNA-328 ameliorates oxidized low-density lipoprotein-induced endothelial cells injury through targeting HMGB1 in atherosclerosis

Atherosclerosis has been recognized as a chronic inflammatory disease, which can harden the vessel wall and narrow the arteries. MicroRNAs exhibit crucial roles in various diseases including atherosclerosis. However, so far, the role of miR-328 in atherosclerosis remains barely explored. Therefore, our study concentrated on the potential role of miR-328 in vascular endothelial cell injury during atherosclerosis. In our current study, we observed that oxidized low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cells (HUVECs) apoptosis and inhibited cell viability dose-dependently and time-dependently. In addition, indicated dosage of ox-LDL obviously triggered HUVECs inflammation and oxidative stress process. Then, it was found that miR-328 in HUVECs was reduced by ox-LDL. HUVECs apoptosis was greatly repressed and cell survival was significantly upregulated by overexpression of miR-328. Furthermore, mimics of miR-328 rescued cell inflammation and oxidative stress process induced by ox-LDL. Oppositely, inhibitors of miR-328 strongly promoted ox-LDL-induced endothelial cells injury in HUVECs. By using bioinformatics analysis, high-mobility group box-1 (HMGB1) was predicted as a downstream target of miR-328. HMGB1 has been reported to be involved in atherosclerosis development. The correlation between miR-328 and HMGB1 was validated in our current study. Taken these together, it was implied that miR-328 ameliorated ox-LDL-induced endothelial cells injury through targeting HMGB1 in atherosclerosis.

Blockade of NEAT1 represses inflammation response and lipid uptake via modulating miR-342-3p in human macrophages THP-1 cells

Atherosclerosis has been recognized as a chronic inflammation process induced by lipid of the vessel wall. Oxidized low-density lipoprotein (ox-LDL) can drive atherosclerosis progression involving macrophages. Recently, long noncoding RNAs (lncRNAs) have been reported to play critical roles in atherosclerosis development. In our current study, we focused on the biological roles of lncRNA NEAT1 in atherosclerosis progress. Here, we found that ox-LDL was able to trigger human macrophages THP-1 cells, a human monocytic cell line, apoptosis in a dose-dependent and time-dependent course. In addition, we observed that NEAT1 was significantly increased in THP-1 cells incubated with ox-LDL and meanwhile miR-342-3p was greatly decreased. Then, NEAT1 was silenced by transfection of small interfering RNA (siRNA) of NEAT1 into THP-1 cells. As exhibited, CD36, oil-red staining levels, total cholesterol (TC), total cholesterol (TG) levels and THP-1 cell apoptosis were obviously repressed by knockdown of NEAT1. Furthermore, inhibition of NEAT1 contributed to the repression of inflammation in vitro. Interleukin 6 (IL-6), IL-1β, cyclooxygenase-2 (COX-2) and tumour necrosis factor-alpha (TNF-α) protein levels were remarkably depressed by NEAT1 siRNA in THP-1 cells. By using bioinformatics analysis, miR-342-3p was predicted as a downstream target of NEAT1 and the correlation between them was confirmed in our study. Moreover, overexpression of miR-342-3p could also greatly suppress inflammation response and lipid uptake in THP-1 cells. Knockdown of NEAT1 and miR-342-3p mimics inhibited lipid uptake in THP-1 cells. In conclusion, we implied that blockade of NEAT1 repressed inflammation response through modulating miR-342-3p in human macrophages THP-1 cells and NEAT1 may offer a promising strategy to treat atherosclerotic cardiovascular diseases.

Silence of long intergenic noncoding RNA HOTAIR ameliorates oxidative stress and inflammation response in ox-LDL-treated human macrophages by upregulating miR-330-5p

Evidence of the involvement of long noncoding RNAs (lncRNAs) in atherosclerosis is growing but still not well characterized. Here, we concentrated on the biological roles of lncRNA HOX transcription antisense RNA (HOTAIR) in atherosclerosis. In our study, we found that oxidized low-density lipoprotein (ox-LDL) induced human macrophages THP-1 cells apoptosis dose dependently and time dependently. Meanwhile, HOTAIR was significantly increased in THP-1 cells treated with ox-LDL. Then, HOTAIR was modulated by infection of LV-short hairpin RNA (shRNA) and LV-HOTAIR into THP-1 cells. As displayed, CD36, Oil Red O staining levels, total cholesterol, triglyceride levels and dil-ox-LDL uptake rate were greatly repressed by the silence of HOTAIR while triggered by overexpression of HOTAIR. Moreover, knockdown of HOTAIR suppressed reactive oxygen species, malondialdehyde levels, increased superoxide dismutase activity and cell apoptosis were also restrained. Reversely, overexpression of HOTAIR exhibited an opposite phenomenon. In addition, interleukin 6 (IL-6), IL-1β, cyclo-oxygenase 2, and tumor necrosis factor α protein levels were significantly depressed by LV-shRNA) of HOTAIR while increased by upregulation of HOTAIR in THP-1 cells. By carrying out bioinformatics analysis, miR-330-5p was predicted as a target of HOTAIR and the correlation between them was validated in our current study. MiR-330-5p was greatly decreased in THP-1 cells incubated with ox-LDL and overexpression of miR-330-5p was able to inhibit oxidative stress and inflammation process. Taken together, it was implied that HOTAIR contributed to atherosclerosis development by downregulating miR-330-5p in human macrophages.

The cardioprotective effect of thymoquinone on ischemia-reperfusion injury in isolated rat heart via regulation of apoptosis and autophagy

Thymoquinone (TQ), as the active constituents of black cumin (Nigella sativa) seed oil, has been reported to have potential protective effects on the cardiovascular system. This study aimed to investigate the effects and the underlying mechanisms of TQ on myocardial ischemia-reperfusion (I/R) injury in Langendorff-perfused rat hearts. Wister rat hearts were subjected to I/R and the experimental group were pretreated with TQ prior to I/R. Hemodynamic parameters, myocardial infarct size, cardiac marker enzymes, superoxide dismutase (SOD), malondialdehyde (MDA) content, and cardiomyocyte apoptosis were assayed. Compared with the untreated group, TQ preconditioning significantly improved cardiac function, reduced infarct size, decreased cardiac lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) levels, suppressed enedoxidative stress, and apoptosis. In addition, TQ treatment promoted autophagy, which was partially reversed by chloroquine (CQ), a kind of autophagy blocker. Our study suggests that TQ can protect heart against I/R injury, which is associated with anti-oxidative and anti-apoptotic effects through activation of autophagy.

Apigenin sensitizes hepatocellular carcinoma cells to doxorubic through regulating miR-520b/ATG7 axis

Chemo-resistance is a serious obstacle for successful treatment of cancer. Apigenin, a dietary flavonoid, has been reported as an anticancer drug in various malignant cancers. This study aimed to investigate the potential chemo-sensitization effect of apigenin in doxorubicin-resistant hepatocellular carcinoma cell line BEL-7402/ADM. We observed that apigenin significantly enhanced doxorubicin sensitivity, induced miR-520b expression and inhibited ATG7-dependent autophagy in BEL-7402/ADM cells. In addition, we also showed that miR-520b mimics increased doxorubicin sensitivity and inhibited ATG7-dependent autophagy. Meanwhile, we indicated that ATG7 was a potential target of miR-520b. Furthermore, APG inhibited the growth of hepatocellar carcinoma xenografts in nude mice by up-regulating miR-520b and inhibiting ATG7. Our finding provides evidence that apigenin sensitizes BEL-7402/ADM cells to doxorubicin through miR-520b/ATG7 pathway, which furtherly supports apigenin as a potential chemo-sensitizer for hepatocellular carcinoma.

MicroRNA-93 inhibits ischemia-reperfusion induced cardiomyocyte apoptosis by targeting PTEN

MicroRNAs have been implicated in some biological and pathological processes, including the myocardial ischemia/reperfusion (I/R) injury. Recent findings demonstrated that miR-93 might provide a potential cardioprotective effect on ischemic heart disease. This study was to investigate the role of miR-93 in I/R-induced cardiomyocyte injury and the potential mechanism. In this study, we found that hypoxia/reoxygenation (H/R) dramatically increased LDH release, MDA contents, ROS generation, and endoplasmic reticulum stress (ERS)-mediated cardiomyocyte apoptosis, which were attenuated by co-transfection with miR-93 mimic. Phosphatase and tensin homolog (PTEN) was identified as the target gene of miR-93. Furthermore, miR-93 mimic significantly increased p-Akt levels under H/R, which was partially released by LY294002. In addtion, Ad-miR-93 also attenuated myocardial I/R injury in vivo, manifested by reduced LDH and CK levels, infarct area and cell apoptosis. Taken together, our findings indicates that miR-93 could protect against I/R-induced cardiomyocyte apoptosis by inhibiting PI3K/AKT/PTEN signaling.

Icariin protects against ischemia‑reperfusion injury in H9C2 cells by upregulating heat shock protein 20

Icariin (ICA) has been implicated in certain biological and pathological processes, including myocardial ischemia/reperfusion (I/R) injury. The aim of the present study was to investigate the role of ICA in I/R‑induced cardiomyocyte injury and the potential underlying mechanism. Cell proliferation and apoptosis of H9C2 cells was determined by cell counting kit‑8 and flow cytometry assays. In addition, reactive oxygen species (ROS) production in H9C2 cells was measured by flow cytometry. Reverse transcription‑quantitative polymerase chain reaction and western blot assay were performed to examine the expression levels of proteins, including HSP20, B‑cell lymphoma 2 (Bcl‑2), cytochrome complex (Cyt‑c), apoptotic protease activating factor 1 (APAF1), caspase‑9 andcaspase‑3, and the phosphorylation of Akt (p‑Akt) in H9C2 cells. The present results demonstrated that, compared with the control group, the I/R group demonstrated significantly reduced levels of HSP20 expression and cell proliferation, and increased apoptosis and ROS production in H9C2 cells. In parallel, the expression levels of Cyt‑c, APAF1, caspase‑9 and caspase‑3 were significantly increased in the I/R group, although Bcl‑2 and p‑Akt/Akt expression levels were decreased. Furthermore, compared with the I/R group, ICA treatment and/or HSP20 overexpression significantly improved cardiac function, as evidenced by promoted cell proliferation and inhibited apoptosis of H9C2 cells. The current study indicates that ICA exerts a cardioprotective effect against I/R injury, which is associated with the upregulation of HSP20.

Co-expression analysis reveals key gene modules and pathway of human coronary heart disease

Coronary heart disease is a kind of disease which causes great injury to people world-widely. Although gene expression analyses had been performed previously, to our best knowledge, systemic co-expression analysis for this disease is still lacking to date. Microarray data of coronary heart disease was downloaded from NCBI with the accession number of GSE20681. Co-expression modules were constructed by WGCNA. Besides, the connectivity degree of eigengenes was analyzed. Furthermore, GO and KEGG enrichment analysis was performed on these eigengenes in these constructed modules. A total of 11 co-expression modules were constructed by the 3000 up-regulated genes from the 99 samples with coronary heart disease. The average number of genes in these modules was 270. The interaction analysis indicated the relative independence of gene expression in these modules. The functional enrichment analysis showed that there was a significant difference in the enriched terms and degree among these 11 modules. The results showed that modules 9 and 10 played critical roles in the occurrence of coronary disease. Pathways of hsa00190 (oxidative phosphorylation) and (hsa01130: biosynthesis of antibiotics) were thought to be closely related to the occurrence and development of coronary heart disease. Our result demonstrated that modules 9 and 10 were the most critical modules in the occurrence of coronary heart disease. Pathways as hsa00190 (oxidative phosphorylation) and (hsa01130: biosynthesis of antibiotics) had the potential to serve as the prognostic and predictive marker of coronary heart disease.

Co-expression network analysis of long noncoding RNAs (IncRNAs) and cancer genes revealsSFTA1P and CASC2abnormalities in lung squamous cell carcinoma

Lung squamous cell carcinoma(LSCC) is the most common and aggressive lung tumor with poor clinical outcome. Previously studies showed that deregulation of long noncoding RNAs (lncRNAs) were involved in LSCC. We intended to figure out the role of lncRNAs in the regulation process of cancer-related genes and pathways they are involved. Data of 552 samples, including 501 cancer samples and 51 normal ones, were extracted from The Cancer Genome Atlas (TCGA). Differentially expressed lncRNAs (DEIs) were screened out (FDR<0.05, |logFC|>1) and then followed by GO ontology and KEGG annotation analysis. Oncogenes from COSMIC data set and Tumor suppressor genes (TSGs) from TSGene data set were collected and analyzed by gene Set Enrichment Analysis (GSEA) . The differentially expressed oncogenes and tumor supressor gene (TSGs) were obtained and co-expression analysis was conducted to generate co-expression lncRNA-gene pairs, which can be helpful in figuring out the role of lncRNA in the regulation of oncogenes and tumor suppressor genes. A total of 31 lncRNAs with low expression levels and 37 lncRNAs with high expression levels were screened out and most of them were enriched in pathways such as meiosis, male gamete generation, defensins. Of note, SFTA1P and CASC2 were found to be related with most of the oncogenes and TSGs by co-expression analysis. We suggested SFTA1P and CASC2 played important role in the regulation of both oncogene and TSGs during the carcinogenesis of LSCC and have the potential to be applied in future diagnosis, prognostic process and target therapy of LSCC.

TMEM88, CCL14 and CLEC3B as prognostic biomarkers for prognosis and palindromia of human hepatocellular carcinoma

Hepatocellular carcinoma is one of the most mortal and prevalent cancers with increasing incidence worldwide. Elucidating genetic driver genes for prognosis and palindromia of hepatocellular carcinoma helps managing clinical decisions for patients. In this study, the high-throughput RNA sequencing data on platform IlluminaHiSeq of hepatocellular carcinoma were downloaded from The Cancer Genome Atlas with 330 primary hepatocellular carcinoma patient samples. Stable key genes with differential expressions were identified with which Kaplan-Meier survival analysis was performed using Cox proportional hazards test in R language. Driver genes influencing the prognosis of this disease were determined using clustering analysis. Functional analysis of driver genes was performed by literature search and Gene Set Enrichment Analysis. Finally, the selected driver genes were verified using external dataset GSE40873. A total of 5781 stable key genes were identified, including 156 genes definitely related to prognoses of hepatocellular carcinoma. Based on the significant key genes, samples were grouped into five clusters which were further integrated into high- and low-risk classes based on clinical features. TMEM88, CCL14, and CLEC3B were selected as driver genes which clustered high-/low-risk patients successfully (generally, p = 0.0005124445). Finally, survival analysis of the high-/low-risk samples from external database illustrated significant difference with p value 0.0198. In conclusion, TMEM88, CCL14, and CLEC3B genes were stable and available in predicting the survival and palindromia time of hepatocellular carcinoma. These genes could function as potential prognostic genes contributing to improve patients' outcomes and survival.

Apigenin sensitizes BEL-7402/ADM cells to doxorubicin through inhibiting miR-101/Nrf2 pathway

Chemo-resistance is one of the main obstacle in hepatocellular carcinoma therapy. Apigenin as a natural bioflavonoid has been exhibited anti-cancer properties in various malignant cancers. The aim of this study is to evaluate the potential chemo-sensitization effect of apigenin in doxorubicin-resistant hepatocellular carcinoma cell line BEL-7402/ADM and to investigate its possible mechanism. We found that apigenin significantly reversed doxorubicin sensitivity and induced caspase-dependent apoptosis in BEL-7402/ADM cells. Furthermore, apigenin induced miR-101 expression, and overexpression of miR-101 mimicked the doxorubicin-sensitizing effect of apigenin. Importantly, we showed that miR-101 was able to target the 3'-UTR of Nrf2. The results suggested that apigenin sensitizes BEL-7402/ADM cells to doxorubicin through miR-101/Nrf2 pathway, which furtherly supports apigenin as a potential chemo-sensitizer for hepatocellular carcinoma.

Systematic analysis of coronary artery disease datasets revealed the potential biomarker and treatment target

Coronary artery disease caused about 1 of every 7 deaths in the United States and early prevention was potential to decrease the incidence and mortality. We aimed to figure the genes involving in the coronary artery disease using meta-anlaysis. Five datasets of coronary heart disease from GEO series were retrieved and data preprocessing and quality control were carried out. Moderated t-test was used to decide the differentially expressed genes for a single dataset. And the combined p-value using systematic-analysis methods were conducted using MetaDE. The pathway enrichment was carried out using Reactome database. Protein-protein interactions of the identified differentially expressed genes were also analyzed using STRING v10.0 online tool. After removing unidentified or intermediate samples and a total of 238 cases and 189 matched or partially matched control from five microarray datasets were retrieved from GEO. Six different quality control measures were calculated and PCA biplots were plotted in order to visualize the quantitative measure. The first two PCs captured 91% of the variance and we decided to include all of the datasets for systematic analysis. Using the FDR cut-off as 0.1, nine genes, including LFNG, ID3, PLA2G7, FOLR3, PADI4, ARG1, IL1R2, NFIL3 and MGAM, were differentially expressed according to maxP. Their protein-protein interactions showed that they were closely connected and 24 Reactome pathways were related to coronary artery disease. We concluded that pathways related to immune responses, especially neutrophil degranulation, were associated with coronary heart disease.

Identification of MSX1 and DCLK1 as mRNA Biomarkers for Colorectal Cancer Detection Through DNA Methylation Information

Colorectal cancer is the second most deadly malignancy in the United States. However, the currently screening options had their limitation. Novel biomarkers for colorectal cancer detections are necessary to reduce the mortality. The clinical information, mRNA expression levels and DNA methylation information of colorectal cancer were downloaded from TCGA. The patients were separated into training group and testing group based on their platforms for DNA methylation. Beta values of DNA methylation from tumor tissues and normal tissues were utilized to figure out the position that were differentially methylated. The expression levels of mRNA of thirteen genes, whose CpG islands were differentially methylated, were extracted from the RNA-Seq results from TCGA. The probabilities whether the mRNA was differentially expressed between tumor and normal samples were calculated using Student's t-test. Logistic regression and decision tree were built for cancer detection and their performances were evaluated by the area under the curve (AUC). Twenty-four genomic locations were differentially methylated, which could be mapped to eleven genes. Nine out of eleven genes had differentially expressed mRNA levels, which were used to build the model for cancer detection. The final detection models consisting of mRNA expression levels of these nine genes had great performances on both training group and testing group. The model that constructed in this study suggested MSX1 and DCLK1 might be used in colorectal cancer detection or as target of cancer therapies. J. Cell. Physiol. 232: 1879-1884, 2017. © 2016 Wiley Periodicals, Inc.

Chrysin enhances sensitivity of BEL-7402/ADM cells to doxorubicin by suppressing PI3K/Akt/Nrf2 and ERK/Nrf2 pathway

Nuclear factor-E2-related factor 2 (Nrf2) is an important cytoprotective transcription factor which plays a key role in antioxidant and detoxification processes. Recent studies have reported that development of chemoresistance is associated with the constitutive activation of the Nrf2-mediated signaling pathway in many types of cancer cells. Here, we investigated whether Nrf2 was associated with drug resistant in doxorubicin resistant BEL-7402 (BEL-7402/ADM) cells, and if chrysin could reverse drug resistance in BEL-7402/ADM cells. We found that remarkable higher level of Nrf2 and its target proteins in BEL-7402/ADM cells compared to BEL-7402 cells. Similarly, intracellular Nrf2 protein level was significantly decreased and ADM resistance was partially reversed by Nrf2 siRNA in BEL-7402/ADM cells. chrysin is a potent Nrf2 inhibitor which sensitizes BEL-7402/ADM cells to ADM and increases intracellular concentration of ADM. Mechanistically, chrysin significantly reduced Nrf2 expression at both the mRNA and protein levels through down-regulating PI3K-Akt and ERK pathway. Consequently, expression of Nrf2-downstream genes HO-1, AKR1B10, and MRP5 were reduced and the Nrf2-dependent chemoresistance was suppressed. In conclusion, these results clearly indicate that activation of Nrf2 is associated with drug resistance in BEL-7402/ADM cells and chrysin may be an effective adjuvant sensitizer to reduce anticancer drug resistance by down-regulating Nrf2 signaling pathway.

[The role of PEP-1-SOD1 fusion protein on ischemia-reperfusion injury in isolated perfused rat hearts.]

OBJECTIVE

The transduction efficiency of the purified PEP-1-SOD1 fusion protein and the effects of PEP-1-SOD1 fusion protein on ischemia reperfusion injury in the isolated perfused rat hearts were investigated.

METHODS

The constructed pET15b-SOD1 and pET15b-PEP-1-SOD1 were transformed into BL21 (DE3) for expression and purification of SOD1 and PEP-1-SOD1, respectively. Isolated perfused rat hearts were subjected to 60 min of global ischemia and 30 min of reperfusion and treated with vehicle, 100 micromol/L SOD1 and 25, 50, 100 micromol/L PEP-1-SOD1, respectively. The transduction efficiency was evaluated with immunofluorescent microscopy and Western blot. The enzyme activity of the transduced PEP-1-SOD1 was measured with commercial SOD detection kit. The MDA content in myocardial tissue and the CK activity in coronary exudate at 15 min after reperfusion were also measured. Cardiomyocyte apoptosis was detected with TUNEL. The infarct size was determined in isolated hearts 60 min after reperfusion with TTC staining.

RESULTS

Immunofluorescent microscopy and Western blot demonstrated PEP-1-SOD1 was transduced into myocardial tissue in a dose-dependent manner, whereas SOD1 could not be detected in SOD1 group. SOD activity in control, SOD1 group, 25, 50, 100 micromol/L PEP-1-SOD1 groups was (10.06 +/- 0.77) U/mg prot, (10.59 +/- 0.71) U/mg prot, (32.29 +/- 1.42) U/mg prot, (43.16 +/- 1.16) U/mg prot, (55.14 +/- 1.59) U/mg prot, respectively. MDA content in corresponding groups was (1.48 +/- 0.19) nmol/mg prot, (1.39 +/- 0.11) nmol/mg prot, (1.01 +/- 0.14) nmol/mg prot, (0.73 +/- 0.13) nmol/mg prot, (0.50 +/- 0.06) nmol/mg prot, respectively. CK activity in corresponding groups was (1.73 +/- 0.58) U/mg prot,(1.68 +/- 0.14) U/mg prot,(1.40 +/- 0.28) U/mg prot,(0.97 +/- 0.39) U/mg prot, (0.61 +/- 0.56) U/mg prot, respectively. Cardiomyocyte apoptotic index in corresponding groups was (17.25 +/- 0.75)%, (16.63 +/- 1.07)%, (11.50 +/- 0.57) U/mg prot, (6.50 +/- 0.63) U/mg prot, (4.13 +/- 0.52)%, repectively. The percentage of myocardial infarction area was (55.13 +/- 2.18)%, (52.13 +/- 2.59)%, (33.88 +/- 2.06)%, (25.50 +/- 2.16)%, (15.38 +/- 1.14)%, respectively. Compared with control group and SOD1 group, all P < 0.01 These results demonstrated the enzyme activity of the transduced PEP-1-SOD1 was significantly increased in a dose-dependent manner and the MDA content, CK activity, the cardiomyocyte apoptotic index and the infarct size was decreased siginificantly in PEP-1-SOD1 pretreatment groups compared with SOD1 group.

CONCLUSION

The native, biologically active form of PEP-SOD1 fusion protein could be effectively transduced into the isolated rat hearts subjecting ischemia reperfusion injury in a dose-dependent manner. The transduced PEP-1-SOD1 has protective effects on ischemia reperfusion injury in the isolated rat hearts.