Apolipoprotein A-IV restrains fat accumulation in skeletal and myocardial muscles by inhibiting lipogenesis and activating PI3K-AKT signalling.

BACKGROUND: One of the pathological characteristics of obesity is fat accumulation of skeletal muscles (SKM) and the myocardium, involving mechanisms of insulin resistance and abnormal lipid metabolism. Apolipoprotein A-IV (ApoA-IV) is an essential gene in both glucose and lipid metabolisms. MATERIALS AND METHODS: Using high-fat diet (HFD) induced obese apoA-IV-knockout mice and subsequent introduction of exogenous recombinant-ApoA-IV protein and adeno-associated virus (AAV)-transformed apoA-IV, we examined lipid metabolism indicators of SKM and the myocardium, which include triglyceride (TG) content, RT-PCR for lipogenic indicators and western blotting for AKT phosphorylation. Similarly, we used high-glucose-fed or palmitate (Pal)-induced C2C12 cells co-cultured with ApoA-IV protein to evaluate glucose uptake, the phosphoinositide 3-kinase (PI3K)-AKT pathway, and lipid metabolisms. RESULTS: In stable obese animal models, we find ApoA-IV-knockout mice show elevated TG content, enhanced expression of lipogenic enzymes and diminished phosphorylated AKT in SKM and the myocardium, but both stable hepatic expression of AAV-apoA-IV and brief ApoA-IV protein administration suppress lipogenesis and promote AKT phosphorylation. In a myoblast cell line C2C12, ApoA-IV protein suppresses Pal-induced lipid accumulation and lipogenesis but enhances AKT activation and glucose uptake, and the effect is abolished by a PI3K inhibitor. CONCLUSION: We find that ApoA-IV reduces fat accumulation by suppressing lipogenesis and improves glucose uptake in SKM and the myocardium by regulating the PI3K-AKT pathway.

Apolipoprotein A-IV reduced metabolic inflammation in white adipose tissue by inhibiting IKK and JNK signaling in adipocytes.

Apolipoprotein A-IV (ApoA-IV) plays a role in satiation and serum lipid transport. In diet-induced obesity (DIO) C57BL/6J mice, ApoA-IV deficiency induced in ApoA-IV-/-knock-out (KO mice) resulted in increased bodyweight, insulin resistance (IR) and plasma free fatty acid (FFA), which was partially reversed by stable ApoA-IV-green fluorescent protein (KO-A4-GFP) transfection in KO mice. DIO KO mice exhibited increased M1 macrophages in epididymal white adipose tissue (eWAT) as well as in the blood. Based on RNA-sequencing analyses, cytokine-cytokine receptor interactions, T cell and B cell receptors, and especially IL-17 and TNF-α, were up-regulated in eWAT of DIO ApoA-IV KO compared with WT mice. Supplemented ApoA-IV suppressed lipopolysaccharide (LPS)-induced IKK and JNK phosphorylation in Raw264.7 macrophage cell culture assays. When the culture medium was supplemented to 3T3-L1 adipocytes they exhibited an increased sensitivity to insulin. ApoA-IV protects against obesity-associated metabolic inflammation mainly through suppression in M1 macrophages of eWAT, IL17-IKK and IL17-JNK activity.

Single-cell RNA sequencing reveals a novel inhibitory effect of ApoA4 on NAFL mediated by liver-specific subsets of myeloid cells.

The liver immune microenvironment is a key element in the development of hepatic inflammation in NAFLD. ApoA4 deficiency increases the hepatic lipid burden, insulin resistance, and metabolic inflammation. However, the effect of ApoA4 on liver immune cells and the precise immune cell subsets that exacerbate fatty liver remain elusive. The aim of this study was to profile the hepatic immune cells affected by ApoA4 in NAFL. We performed scRNA-seq on liver immune cells from WT and ApoA4-deficient mice administered a high-fat diet. Immunostaining and qRT-PCR analysis were used to validate the results of scRNA-seq. We identified 10 discrete immune cell populations comprising macrophages, DCs, granulocytes, B, T and NK&NKT cells and characterized their subsets, gene expression profiles, and functional modules. ApoA4 deficiency led to significant increases in the abundance of specific subsets, including inflammatory macrophages (2-Mφ-Cxcl9 and 4-Mφ-Cxcl2) and activated granulocytes (0-Gran-Wfdc17). Moreover, ApoA4 deficiency resulted in higher Lgals3, Ctss, Fcgr2b, Spp1, Cxcl2, and Elane levels and lower Nr4a1 levels in hepatic immune cells. These genes were consistent with human NAFLD-associated marker genes linked to disease severity. The expression of NE and IL-1ß in granulocytes and macrophages as key ApoA4 targets were validate in the presence or absence of ApoA4 by immunostaining. The scRNA-seq data analyses revealed reprogramming of liver immune cells resulted from ApoA4 deficiency. We uncovered that the emergence of ApoA4-associated immune subsets (namely Cxcl9+ macrophage, Cxcl2+ macrophage and Wfdc17+ granulocyte), pathways, and NAFLD-related marker genes may promote the development of NAFL. These findings may provide novel therapeutic targets for NAFL and the foundations for further studying the effects of ApoA4 on immune cells in various diseases.

Apolipoprotein A4 Restricts Diet-Induced Hepatic Steatosis via SREBF1-Mediated Lipogenesis and Enhances IRS-PI3K-Akt Signaling.

SCOPE: Hepatic steatosis and insulin resistance (IR) are risk factors for many metabolic syndromes such as NAFLD and T2DM. ApoA4 improves glucose hemostasis by increasing glucose-stimulated insulin secretion and glucose uptake via PI3K-Akt activation in adipocytes. However, whether ApoA4 has an effect on hepatic steatosis or IR remains unclear. METHODS AND RESULTS: ApoA4-knockout (KO) aggravates diet-induced obesity, hepatic steatosis, and IR in mice promoted by increased hepatic lipogenesis gene expression based on RNA-seq data. Conversely, liver-specific overexpression of ApoA4 via AAV-ApoA4 transduction reverses the effect in ApoA4-KO mice, accompanied by suppressed hepatic lipogenesis, increased lipolysis, and fatty acid oxidation. Short-term treatment with recombinant ApoA4 protein improves glucose clearance and liver insulin sensitivity, and reduces hepatic lipogenesis gene expression in the absence of insulin. Moreover, in primary hepatocytes and a hepatic cell line, ApoA4 improves hepatic glucose uptake via IRS-PI3K-Akt signaling and decreases fat deposition and hepatic lipogenesis gene expression by inhibiting SREBF1 activity. CONCLUSION: ApoA4 restricts hepatic steatosis by inhibiting SREBF1-mediated lipogenesis and improves insulin sensitivity and glucose uptake via IRS-PI3K-Akt signaling in the liver. These findings indicate that ApoA4 may serve as a therapeutic target for obesity-associated NAFLD.

Several nAChRs gene variants are associated with phenotypes of heroin addiction in Chinese Han population.

Heroin addiction is a chronic and complex brain disease. Nicotinic acetylcholine receptors (nAChRs) have been shown as major control points in many of the neurological and physiological disorders involved in heroin addiction. In the present study, thirty-three SNPs across nine nAChR genes were selected and probed for their associations with heroin addiction phenotypes in 801 unrelated northwestern Chinese Han patients. We found that rs2565055 in CHRNA2 gene was associated with daily dose of methadone treatment, and rs2672215, rs2672216 and rs2741865 in CHRNA10 gene were associated with the duration of the transition from first use to dependence (DTFUD). Cox multivariable regression analysis revealed that rs3743075, rs6495309 in CHRNA3, rs2304297 in CHRNA6, and rs1948 in CHRNB4 were associated with sexual desire in patients with heroin addiction. These findings were further supported by the identification of a haplotype block spanning CHRNA5, CHRNA3, and CHRNB4 that is correlated with changes in sexual desire after long-term heroin use. Our findings highlight associations between polymorphisms in nAChRs genes and the phenotypes of heroin addiction in the Chinese Han population. We suggest several nAChRs subunits as potential novel targets for the treatment of heroin addiction.

Methylation quantitative trait locus rs5326 is associated with susceptibility and effective dosage of methadone maintenance treatment for heroin use disorder.

RATIONALE: Opioid use disorder is a complicated brain disease with high heritability. The underlying mechanisms of the genetic underpinnings in the susceptibility and treatment response of opioid use disorder remain elusive. OBJECTIVES: To reveal the potential associations of genotypes and gene methylations of dopaminergic system genes, as well as roles of them in opioid use disorder. In the present study, we detected the DNA methylation in the promoter regions of five representative dopaminergic system genes (DRD1, DRD2, SLC6A3, TH, and COMT) between 120 patients with heroin use disorder in methadone maintenance treatment (MMT) program and 111 healthy controls. The associations of 25 SNPs in the above genes and methylation of 237 CpG sites, known as methylation quantitative trait loci (mQTLs), were determined. Then, the correlations of the above mQTLs and traits of heroin use disorder were analyzed in a sample set of 801 patients with heroin use disorder and 930 healthy controls. RESULTS: Our results demonstrated that several mQTLs in the DRD1 and DRD2 genes were identified both in the heroin use disorder and healthy control groups. Interestingly, rs4867798-CpG_174872884 and rs5326-CpG_174872884 in the DRD1 gene were the unique SNP-CpG pairs in the patients with heroin use disorder. Furthermore, mQTL rs5326 was associated with the susceptibility and effective dosage of MMT for heroin use disorder, and demonstrated allele-specific correlation with the expression of the DRD1 gene in the human caudate. CONCLUSIONS: Our findings suggest that some mQTLs may be associated with traits of opioid use disorder by implicating the DNA methylation and gene expression.

Knockdown of DLGAP5 suppresses cell proliferation, induces G2/M phase arrest and apoptosis in ovarian cancer.

Discs large-associated protein 5 (DLGAP5) is a microtubule-associated protein and is reported to exert oncogenic role in tumorigenesis, including lung cancer and hepatocellular carcinoma. However, the prognostic value and biological function of DLGAP5 in ovarian cancer (OC) still remain unclear. The present study investigated the expression pattern of DLGAP5 by searching the Oncomine microarray database. The correlation between DLGAP5 and survival prognosis of OC patients was analyzed by the online tool KM-plotter. Knockdown of DLGAP5 was achieved by transfection with small interfering RNA targeting DLGAP5 in two OC cell lines (SKOV3 and CAOV3). Cell proliferation was assessed by Cell Counting Kit-8 assay and colony-formation assay. Flow cytometry was utilized to determine the effects of DLGAP5 on cell cycle distribution and apoptosis. The present study data showed that DLGAP5 was significantly upregulated in OC and its higher expression was associated with poor survival prognosis. Knockdown of DLGAP5 significantly suppressed cell proliferation, induced cell cycle G2/M phase arrest and apoptosis. Western blot analysis further demonstrated that DLGAP5 knockdown downregulated the expression of CDK1, Cyclin B1 and Bcl-2, but upregulated Bax expression. Collectively, these data demonstrate that DLGAP5 might be a promising prognostic therapeutic target for OC treatment.

Hepatoprotective effect of apolipoprotein A4 against carbon tetrachloride induced acute liver injury through mediating hepatic antioxidant and inflammation response in mice.

Apolipoprotein A4 (ApoA4) regulates lipid and glucose metabolism and exerts anti-inflammatory effects in atherogenesis and colitis. The present study explored the presumed protective role of ApoA4 in carbon tetrachloride (CCl4)-induced acute liver injury (ALI) in mice. The ALI model in wild type (WT), ApoA4 knock-out (ApoA4-KO) and ApoA4 transgenic (ApoA4-TG) mice was induced by a single intraperitoneal administration of CCl4. Liver and blood were harvested from mice to assess liver functions, immunohistological changes, immune cell populations and cytokine profiles. ApoA4 deficiency aggravated, and ApoA4 overexpression alleviated CCl4-inflicted liver damage by controlling levels of anti-oxidant enzymes. ApoA4 deletion increased the recruitment of monocytes/macrophages into the injured liver and upregulated the plasma levels of IL-6, TNF-α and MCP-1, but lower IL-10 and IFN-γ. ApoA4 over-expression rescued this effect and resulted in lower percentages of monocytes/macrophages and dendritic cells, the ratio of blood pro-inflammatory to anti-inflammatory monocytes and reduced plasma concentrations of IL-6, but enhanced IL-10 and IFN-γ. We propose ApoA4 as a potential new therapeutic target for the management of liver damage.

Involvement of NEAT1/miR-133a axis in promoting cervical cancer progression via targeting SOX4.

NEAT1 is an important tumor oncogenic gene in various tumors. Nevertheless, its involvement remains poorly studied in cervical cancer. Our study explored the functional mechanism of NEAT1 in cervical cancer. NEAT1 level in several cervical cancer cells was quantified and we found NEAT1 was greatly upregulated in vitro. NEAT1 knockdown inhibited cervical cancer development through repressing cell proliferation, colony formation, capacity of migration, and invasion and also inducing the apoptosis. For another, microRNA (miR)-133a was downregulated in cervical cancer cells and NEAT1 negatively modulated miR-133a expression. Subsequently, we validated that miR-133a functioned as a potential target of NEAT1. Meanwhile, SOX4 is abnormally expressed in various cancers. SOX4 was able to act as a downstream target of miR-133a and silencing of SOX4 can restrain cervical cancer progression. In addition, in vivo assays were conducted to prove the role of NEAT1/miR-133a/SOX4 axis in cervical cancer. These findings implied that NEAT1 served as a competing endogenous RNA to sponge miR-133a and regulate SOX4 in cervical cancer pathogenesis. To sum up, it was implied that NEAT1/miR-133a/SOX4 axis was involved in cervical cancer development.

Overexpression of LINC00037 represses cervical cancer progression by activating mTOR signaling pathway.

Long non-coding RNAs have been reported to play crucial roles in tumorigenesis including cervical cancer. LINC00037 has been identified as a significant regulator in several cancers. Our study was aimed to investigate the function of LINC00037 in cervical cancer progression. LINC00037 was significantly downregulated in human cervical cancer cells (HeLa, HCC94, HT-3, Caski, and SiHa cells) compared with the ectocervical epithelial cells (End1/E6E7 cells). Overexpression of LINC00037 was able to inhibit cervical cancer cell proliferation, induce cell apoptosis, and restrain the cell migration/invasion capacity. Reversely, knockdown of LINC00037 exhibited an opposite process in vitro. mTOR has been recognized as an atypical serine/threonine kinase that is involved in regulating significant cellular functions. In our present study, we observed that the mTOR signaling pathway was strongly activated in human cervical cancer cells. Meanwhile, upregulation of LINC00037 contributed to the inactivation of mTOR signaling whereas downregulation of LINC00037 activated the pathway. Subsequently, in vivo animal models using SiHa cells were established and we proved that LINC00037 repressed cervical cancer progression via targeting the mTOR signaling pathway. All these findings implied that LINC00037 could regulate cervical cancer pathogenesis via mTOR signaling. In conclusion, a novel role of LINC00037 was manifested in cervical cancer progression.

The transcriptome profiles and methylation status revealed the potential cancer-related lncRNAs in patients with cervical cancer.

Cervical cancer continues to be a major public health problem. Although long noncoding RNAs (lncRNAs) were involved in the initiation and progression of cancer, few studies focus on the lncRNAs in the cervical cancer. Here, we systematically studied the clinical information, transcriptome profiling, and methylation array data of cervical squamous cell carcinoma and endocervical adenocarcinoma that retrieved from genomic data commons (GDC). Compared with protein-coding genes, the expression levels of pseudogenes and lncRNAs were much lower. A total of 190 differentially expressed lncRNAs and 2,326 protein-coding genes were identified. Meanwhile, 269 differentially methylation regions (DMRs), where 16 lncRNAs were located, were figured out. Only one lncRNA, LINC00592, which was located in the DMRs, was also found differentially expressed. Several transcriptional regulation genes, such as ZNF20, ZNF441, ZNF573, and TMF1, were highly correlated with the expression of LINC00592, which illustrated its possible function on the transcription. Two microRNAs, which were both associated with tumor progression, can bind to LINC00592. Moreover, LINC00592 were also differentially expressed in other tumors. We proposed, with the help of various databases, that LINC00592 is a potential cancer-related lncRNA in cervical cancer and might activate the cancer progression through the regulation of transcription or structural integrity.

A random forest classifier predicts recurrence risk in patients with ovarian cancer.

Ovarian cancer (OC) is associated with a poor prognosis due to difficulties in early detection. The aims of the present study were to construct a recurrence risk prediction model and to reveal important OC genes or pathways. RNA sequencing data was obtained for 307 OC samples, and the corresponding clinical data were downloaded from The Cancer Genome Atlas database. Additionally, two validation datasets, GSE44104 (20 recurrent and 40 non­recurrent OC samples) and GSE49997 (204 OC samples), were obtained from the Gene Expression Omnibus database. Differentially expressed genes were screened using the differential expression via distance synthesis algorithm, followed by gene ontology enrichment analysis and weighted gene coexpression network analysis (WGCNA). Furthermore, subnetwork analysis was conducted for the protein­protein interaction (PPI) network using the BioNet package. Finally, a random forest classifier was constructed based on the subnetwork nodes, and its reliability was validated using the GSE44104 and GSE49997 validation datasets. A total of 44 upregulated and 117 downregulated genes were identified in the recurrent samples. Enrichment analysis indicated that cytochrome P450 family 17 subfamily A member 1 (CYP17A1) was associated with 'positive regulation of steroid hormone biosynthetic processes'. WGCNA identified turquoise and grey modules that were significantly correlated with status and prognosis. A significant PPI subnetwork containing 16 nodes was also identified, including: Transcription factor GATA­4; fibroblast growth factor 9; aromatase; 3ß­hydroxysteroid dehydrogenase/δ5­4­isomerase type 2; corticosteroid 11ß­dehydrogenase isozyme 1; CYP17A1; pituitary homeobox 2; left­right determination factor 1; homeobox protein ARX; estrogen receptor ß; steroidogenic factor 1; forkhead box protein L2; myocardin; steroidogenic acute regulatory protein mitochondrial; vesicular inhibitory amino acid transporter; and twist­related protein 1. A random forest classifier was constructed using the subnetwork nodes as feature genes, which exhibited a 92% true positive rate when classifying recurrent and non­recurrent OC samples. The classifying efficiency of the random forest classifier was validated using the two other independent datasets. Overall, 44 upregulated and 117 downregulated genes associated with OC recurrence were identified. Furthermore, the 16 subnetwork node genes that were identified may be important molecules in OC recurrence.

Establishment of a SVM classifier to predict recurrence of ovarian cancer.

Gene expression data using retrieved ovarian cancer (OC) samples were used to identify genes of interest and a support vector machine (SVM) classifier was subsequently established to predict the recurrence of OC. Three datasets (GSE17260, GSE44104 and GSE51088) investigating OC gene expression were downloaded from the Gene Expression Omnibus. Differentially expressed genes (DEGs) in samples from patients with non­recurrent and recurrent OC were revealed via a homogeneity test and quality control analysis. A protein­protein interaction (PPI) network was subsequently established for the DEGs using data from Biological General Repository for Interaction Datasets, Human Protein Reference Database and Database of Interacting Proteins. Degrees of interaction and betweenness centrality (BC) scores were calculated for each node in the PPI network. The top 100 genes ranked by BC scores were selected to identify feature genes via recursive feature elimination using the GSE17260 dataset. Following this, a SVM classifier was constructed and further validated using the GSE44104 and GSE51088 datasets and independent gene expression data obtained from the Cancer Genome Atlas (TCGA). A total of 639 DEGs were identified from the three gene expression datasets, and a PPI network including 249 nodes and 354 edges was constructed. A SVM classifier consisting of 39 feature genes (including cullin 3, mouse double minute 2 homolog, aurora kinase A, WW domain containing oxidoreducatase, large tumor suppressor kinase 2, sirtuin 6, staphylococcal nuclease and tudor domain containing 1, leucine rich repeats and immunoglobulin like domains 1 and aurora kinase 1 interacting protein 1) was subsequently constructed. The prediction accuracies of the SVM classifier for GSE17260, GSE44104 and GSE51088 datasets as well as data downloaded from TCGA were revealed to be 92.7, 93.3, 96.6 and 90.4%, respectively. Furthermore, the results of the present study revealed that patients with predicted non­recurrent OC survived significantly longer compared with the patients with predicted recurrent OC (P=6.598x10­6). A SVM classifier consisting of 39 feature genes was established for predicting the recurrence and prognosis of OC. Therefore, the results of the present study suggested that the 39 feature genes may serve important roles in the development of OC and may represent therapeutic biomarkers of OC.

A 15-long non-coding RNA signature to improve prognosis prediction of cervical squamous cell carcinoma.

Long non-coding RNAs (lncRNAs), which have little or no protein-coding capacity, caught a particular interest since their potential roles in the cancer paradigm. As the most common cancer in women, cervical squamous cell carcinoma remains one of the leading causes of deaths from cancer. However, limited evidence is available to determine the role of lncRNAs in the prognosis of cervical squamous cell carcinoma. In this study, we collected lncRNA expression profiling to identify prognosis related lncRNAs for cervical squamous cell carcinoma from TCGA database. In addition, we developed a 15-lncRNA signature based risk score to comprehensively assess the prognostic function of lncRNA. Furthermore, we performed a ROC analysis to identify the optimal cut-off point for classification risk level of the patients. Univariate Cox regression models were used to assess the association between lncRNAs and prognosis of patients with cervical squamous cell carcinoma. A 15-lncRNA based risk score was developed based on the Cox co-efficient of the individual lncRNAs. The prognostic value of this risk score was validated in the complete set and internal testing set. In summary, a 15-lncRNA expression signature (BAIAP2-AS1, RP11-203J24.8, LINC01133, RP1-7G5.6, RP11-147L13.15, SERHL, CTC-537E7.3, RP11-440L14.1, RP11-131N11.4, ILF3-AS1, RP11-80H18.4, RP11-1096G20.5, CTD-2192J16.26, RP11-621L6.3, and RP11-571M6.18) were identified and validated which can predict cervical cancer patient survival. The potential functions of this 15-lncRNA expression signature and individual lncRNAs as prognostic targets of cervical cancer were revealed by this study. Furthermore, these findings may have important implications in the understanding of the potential therapeutic method for the cervical squamous cell carcinoma patients.

A polymeric film probe with a turn-on fluorescence response to hydrogen sulfate ions in aqueous media.

A new kind of hydrophilic copolymer poly(HEMA-co-VNP) was designed and synthesized by the radical copolymerization of 2-hydroxyethylmethacrylate (HEMA) and 2-{[2-(4-vinylbenzyloxy)naphthalen-1-yl]methyleneamino}-(S)-2-phenylethanol (VNP). The desired copolymer showed a highly selective red-shifted emission and a unique chiroptical response upon HSO4 - binding in organic solution. UV-vis and 1H NMR spectroscopic studies revealed that the hydrogen bonding between the imine moiety in the VNP repeating units and HSO4 - is crucial for the high selectivity of the receptor to this anion. As expected, the incorporation of HEMA into the polymer matrix endowed the copolymer excellent hydrophilicity, flexibility and good film-forming properties. Thus, high-quality film sensors could be easily fabricated on quartz plates through spin-casting techniques. The resultant polymeric films can recognize HSO4 - ions among a series of common anions in aqueous solution with high selectivity and sensitivity. The promising new film probe for HSO4 - has distinct characteristics such as a rapid response, enough stability in an aqueous media and practicality.