Peroxisome Proliferator-activated Receptor Signaling Pathway Research Articles

Short hairpin RNA attenuates liver fibrosis by regulating the PPAR‑γ and NF‑κB pathways in HBV‑induced liver fibrosis in mice.

Progressive liver fibrosis, caused by chronic viral infection and metabolic disorders, results in the development of cirrhosis and hepatocellular carcinoma. However, no antifibrotic therapies have been approved to date. In our previous study, adeno-associated virus (AAV) short hairpin RNAs (shRNAs) targeting hepatitis B virus (HBV) and transforming growth factor (TGF)-β administration could persistently inhibit HBV replication and concomitantly prevent liver fibrosis. However, the differentially expressed proteins and critical regulatory networks of AAV-shRNA treatment remain unclear. Accordingly, in the present study, we aimed to analyze differentially expressed proteins in the liver of AAV-shRNA-treated mice with HBV infection and liver fibrosis using isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics and to elucidate the underlying antifibrotic mechanisms. In total 2,743 proteins were recognized by iTRAQ-based quantitative proteomics analysis. Gene Ontology analysis revealed that the differentially expressed proteins mostly participated in peptide metabolism in the biological process category, cytosolic ribosomes in the cell component category, and structural constituents of ribosomes in the molecular function category. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that oxidative stress and the peroxisome proliferator-activated receptor (PPAR) signaling pathway were activated after treatment. Verification studies revealed that AAV-shRNAs inhibited hepatic stellate cell activation and inflammation by suppressing nuclear factor-κB p65 phosphorylation and α-smooth muscle actin expression via upregulation of PPAR-γ. Hepatocytes steatosis was also decreased by activating the PPAR signaling pathway and improving lipid metabolism. The expression level of TGF-β was decreased due to upregulation of PPAR-γ expression and direct inhibition using AAV-shRNA targeting TGF-β. TGF-β-induced oxidative stress was suppressed by increasing glutathione S-transferase Pi 1 and reducing peroxiredoxin 1. Collectively, the present results indicated that AAV-shRNAs were effective in modulating liver fibrosis by reducing oxidative stress, inflammation and activating the PPAR signaling pathway.

Protective effect of picroside I against hepatic fibrosis in mice via sphingolipid metabolism, bile acid biosynthesis, and PPAR signaling pathway

Picroside I, a hepatoprotectant isolated from Picrorhiza kurroa Royle ex Benth and P. scrophulariiflora Pennell, can reduce liver injury in humans and animals. However, its anti-fibrosis effect remains elusive. This work aimed to explore the mechanism underlying the hepatoprotective effect of picroside I against hepatic fibrosis. Male mice (12 mice per group) were randomly divided into six groups: the control group; the model group, which received thioacetamide (TAA); the positive group, which received TAA + S-(5′-adenosyl)-l-methionine (SAMe, 10 mg/kg); the low-dose group, which received TAA + picroside I (25 mg/kg); the middle-dose group, which received TAA + picroside I (50 mg/kg); and the high-dose group, which received TAA + picroside I (75 mg/kg). Serum biochemical indicators were detected, and histological evaluation was performed. Metabolomics and proteomic analyses were conducted via liquid-chromatography coupled with tandem mass spectrometry (LC-MS/MS). Data showed that picroside I could decrease the serum levels of alanine transaminase (ALT), aspartate transaminase (AST), collagen type IV (CIV), N-terminal peptide of type III procollagen (PIIINP), laminin (LN), and hyaluronic acid (HA) and reduced fibrosis area. Picroside I altered metabolomic profiles, including energy, lipid, and glutathione (GSH) metabolism, in ice with fibrosis. Additionally, 25 differentially expressed proteins in the picroside I high-dose-treated group were reversed relative to in the model group. These proteins were involved in the sphingolipid signaling pathway, primary bile acid biosynthesis, and peroxisome proliferator-activated receptor (PPAR) signaling pathway. Moreover, this study revealed how picroside I could protect against TAA-induced liver fibrosis in mice. Results indicated that picroside I can serve as a candidate drug for hepatic fibrosis.

Fufang Xueshuantong alleviates diabetic retinopathy by activating the PPAR signalling pathway and complement and coagulation cascades

Ethnopharmacological relevanceFufang Xueshuantong (FXST) is a traditional Chinese patent medicine composed of Panax notoginseng (Burkill) F.H.Chen (Araliaceae), Salvia miltiorrhiza Bunge (Lamiaceae), Astragalus propinquus Schischkin (Leguminosae), and Scrophularia ningpoensis Hemsl. (Scrophulariaceae). It has been widely used for the treatment of diabetic retinopathy (DR) and exerts a positive clinical therapeutic effect. Aim of the studyThe aim of this study was to observe the effect of FXST on diabetic rat retinas and investigate its pharmacological mechanism for improving DR. MethodsThe diabetic rat model was established by intraperitoneal injection of streptozotocin. The rats were divided into a normal group, diabetic group, and FXST group. The rats in the FXST group were treated with FXST by intragastric administration for 12 weeks while other rats were given the same volume of normal saline. The haemodynamic parameters of the central retinal artery in the rats were measured by ultrasound. Haematoxylin-eosin staining was utilised to observe the pathological structural changes in the retina. The apoptosis of retinal nerve cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling. RNA sequencing was used to screen the differentially expressed genes (DEGs), and enrichment analyses were performed. The DEGs were validated through real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). ResultsThe peak systolic velocity, end diastolic velocity, and mean velocity decreased while the resistance index and pulsatility index increased in the diabetic rat retinas. FXST also improved haemodynamics. In contrast with the diabetic group, FXST allayed the disorder and oedema of the retinal structure in addition to reversing the reductions in retinal thickness and retinal ganglion cell number. It also decreased the apoptosis index of retinal cells. A total of 1134 DEGs were identified by RNA sequencing in the FXST group compared to the diabetic group, including 814 upregulated genes and 320 downregulated genes. These genes were enriched in the complement and coagulation cascades as well as the peroxisome proliferator-activated receptor (PPAR) signalling pathway. Several DEGs, including PPAR gamma, perilipin 4, acyl-CoA dehydrogenase long chain, CD55 molecule, and plasminogen activator urokinase, were identified by qRT-PCR, and the results were consistent with the RNA sequencing data. ConclusionsFXST alleviates DR by improving the haemodynamics and morphological alterations of diabetic rat retinas, which are mediated by complement and coagulation cascades and the PPAR signalling pathway.

Muscle Transcriptome Analysis Reveals Potential Candidate Genes and Pathways Affecting Intramuscular Fat Content in Pigs.

Intramuscular fat (IMF) content plays an essential role in meat quality. For identifying potential candidate genes and pathways regulating IMF content, the IMF content and the longissimus dorsi transcriptomes of 28 purebred Duroc pigs were measured. As a result, the transcriptome analysis of four high- and four low-IMF individuals revealed a total of 309 differentially expressed genes (DEGs) using edgeR and DESeq2 (p < 0.05, |log2(fold change)| ≥ 1). Functional enrichment analysis of the DEGs revealed 19 hub genes significantly enriched in the Gene Ontology (GO) terms and pathways (q < 0.05) related to lipid metabolism and fat cell differentiation. The weighted gene coexpression network analysis (WGCNA) of the 28 pigs identified the most relevant module with 43 hub genes. The combined results of DEGs, WGCNA, and protein–protein interactions revealed ADIPOQ, PPARG, LIPE, CIDEC, PLIN1, CIDEA, and FABP4 to be potential candidate genes affecting IMF. Furthermore, the regulation of lipolysis in adipocytes and the peroxisome proliferator-activated receptor (PPAR) signaling pathway were significantly enriched for both the DEGs and genes in the most relevant module. Some DEGs and pathways detected in our study play essential roles and are potential candidate genes and pathways that affect IMF content in pigs. This study provides crucial information for understanding the molecular mechanism of IMF content and would be helpful in improving pork quality.

Induction of lipid droplets in THP-1 macrophages by multi-walled carbon nanotubes in a diameter-dependent manner: A transcriptomic study

Exposure to multi-walled carbon nanotubes (MWCNTs) might induce lipid droplet (LD) biogenesis, but the roles of physicochemical properties of MWCNTs, as well as the mechanisms, remain poorly understood. In this study, we investigated lipid laden foam formation in THP-1 macrophages exposed to MWCNTs of different diameters, and attempted transcriptomic analysis to study the possible mechanisms. We observed diameter-dependent cytotoxicity, lipid accumulation and intracellular reactive oxygen species production that were more pronounced for MWCNTs with smaller diameters compared with those with larger diameters. However, more MWCNTs with larger diameters were retained in macrophages after 24 h exposure. One possible explanation for the inverse relationship between MWCNT bio-effects and internalization is that macrophages altered the expression of exocytotic genes to export toxic MWCNTs. Transcriptomic data showed that MWCNTs with smaller diameters more effectively altered the expression of genes related with cytotoxicity and lipid metabolism, and KEGG pathway analysis suggested that MWCNTs with smaller diameters activated peroxisome proliferator-activated receptor (PPAR) signalling pathway (map03320), leading to over-expression of perilipin 2, the surface proteins of LDs. Western blot confirmed that MWCNTs effectively promoted CD36, PPARγ and perilipin 2, key components in map03320. Moreover, inhibition of PPARγ by chemicals or siRNA significantly inhibited lipid accumulation induced by MWCNTs with smaller diameters, and perilipin 2 proteins in MWCNT-exposed macrophages could be decreased by PPARγ siRNA. In conclusion, the results of this study revealed the induction of LDs by MWCNTs in a diameter-dependent manner through the activation of PPAR signalling pathway.

Transcriptome signature of two lactation stages in Ghezel sheep identifies using RNA-Sequencing

The expression of genes and their regulation during lactation in Ghezel sheep breed remains less understood. To explore the underlying molecular mechanism of the lactation process in the mammary gland, transcriptome profiles of Iranian fat-tailed Ghezel sheep breed milk at two stages, before (BF) and after peak (AF) stages of lactation were investigated. Functional impacts of differentially expressed genes (DEGs) between BF and AF stages were surveyed using Gene Ontology (GO) and Protein-Protein Interaction (PPI) network analysis. Totally, 75 DEGs were identified between BF and AF stages of lactation. The RNA-Seq results were validated by Q-RT-PCR. Gene ontology of DEGs mainly enriched in metabolic process and oxidative phosphorylation. PPI network analysis also highlighted the contribution of peroxisome proliferator-activated receptors (PPAR) signaling, oxidative phosphorylation and metabolic pathways in the lactation process. Intriguingly, the genes involved in fat metabolism dominantly down-regulated at AF stage. Our results provide new insight into transcriptional changes and add to growing body of knowledge on the lactation process in fat-tailed sheep breeds.

Enhancing fatty acid oxidation negatively regulates PPARs signaling in the heart

High fatty acid oxidation (FAO) is associated with lipotoxicity, but whether it causes lipotoxic cardiomyopathy remains controversial. Molecular mechanisms that may be responsible for FAO-induced lipotoxic cardiomyopathy are also elusive. In this study, increasing FAO by genetic deletion of acetyl-CoA carboxylase 2 (ACC2) did not induce cardiac dysfunction after 16 weeks of high fat diet (HFD) feeding. This suggests that increasing FAO, per se, does not cause metabolic cardiomyopathy in obese mice. We compared transcriptomes of control and ACC2 deficient mouse hearts under chow- or HFD-fed conditions. ACC2 deletion had a significant impact on the global transcriptome including downregulation of the peroxisome proliferator-activated receptors (PPARs) signaling and fatty acid degradation pathways. Increasing fatty acids by HFD feeding normalized expression of fatty acid degradation genes in ACC2 deficient mouse hearts to the same level as the control mice. In contrast, cardiac transcriptome analysis of the lipotoxic mouse model (db/db) showed an upregulation of PPARs signaling and fatty acid degradation pathways. Our results suggest that enhancing FAO by genetic deletion of ACC2 negatively regulates PPARs signaling through depleting endogenous PPAR ligands, which can serve as a negative feedback mechanism to prevent excess activation of PPAR signaling under non-obese condition. In obesity, excessive lipid availability negates the feedback mechanism resulting in over activation of PPAR cascade, thus contributes to the development of cardiac lipotoxicity.

Sirt1 gene confers Adriamycin resistance in DLBCL via activating the PCG-1α mitochondrial metabolic pathway.

Sirt1 is closely related to cells aging, and Sirt1 also plays an important role in diffuse large B-cell lymphoma (DLBCL). However, its mechanism remains unclear. Therefore, we investigated the mechanism of Sirt1 mediated drug-resistance in DLBCL, while the recombinant lentivirus was used to regulate Sirt1 gene expression in DLBCL cell lines. Subsequently, the effect of Sirt1 on DLBCL resistance to Adriamycin was analyzed in vitro. The results show that Sirt1 overexpression confers Adriamycin resistance in DLBCL cell lines. However, inhibition of Sirt1 sensitized DLBCL cell lines to Adriamycin cytotoxicity. Additionally, tumor-bearing mice were used to verify that Sirt1 overexpression confers Adriamycin resistance in vivo after chemotherapy. In addition, we used second-generation sequencing technology and bioinformatics analysis to find that Sirt1 mediated drug-resistance is related to the Peroxisome proliferator-activated receptor (PPAR) signaling pathway, especially to PGC-1α. Interestingly, the mitochondrial energy inhibitor, tigecycline, combined with Adriamycin reversed the cellular resistance caused by Sirt1 overexpression in vivo. Moreover, western blotting and CO-IP assay reconfirmed that Sirt1-mediated drug-resistance is associated with the increased expression of PGC1-α, which induce mitochondrial biogenesis. In summary, this study confirms that Sirt1 is a potential target for DLBCL treatment.

Comparative transcriptome and microbiota analyses provide new insights into the adverse effects of industrial trans fatty acids on the small intestine of C57BL/6 mice.

To reveal the mechanism that links industrial trans fatty acids (iTFAs) to various chronic diseases, we examined the impact of iTFAs on the local microenvironment of the small intestine (duodenum, jejunum and ileum). Forty male 8-week-old mice were fed diets containing one of the following: (1) low soybean oil (LS); (2) high soybean oil (HS); (3) low partially hydrogenated oil (LH), and (4) high partially hydrogenated oil (HH). The analysis of microbiota from small intestinal content was performed by real-time qPCR. The fatty acid composition of small intestine mucosa was measured by GC/MS, and comparative transcriptome of the small intestinal mucosa was analyzed by RNA-sequencing. The intake of iTFAs changed the fatty acid spectrum of the small intestine mucosa, especially the excessive accumulation of iTFA (mainly elaidic acid). For microbiota, the relative abundance of δ- and γ-proteobacteria, Lactobacillus, Desulfovibrio, Peptostreptococcus and Turicibacter were significantly different in the iTFA diet groups compared to the control group. Based on the identification of differently expressed genes(DEGs) and pathway annotation, comparative transcriptome analysis of the small intestine mucosa revealed obvious overexpression of genes involved in the extracellular matrix (ECM)-receptor interaction and the peroxisome proliferator-activated receptor signaling pathway, which suggests that ECM remodeling and abnormal lipid metabolism may have occurred with iTFA ingestion. Our research demonstrated multiple adverse effects of iTFA that may have originated from the small intestine. This finding could be to facilitate the development of new strategies to suppress iTFA-related diseases by reversing the adverse effects of iTFA on intestinal health.

Bioinformatics analysis of different candidate genes involved in hepatocellular carcinoma induced by HepG2 cells or tumor cells of patients.

ObjectiveHepatocellular carcinoma (HCC) is a common cancer with a high mortality rate; the molecular mechanism involved in HCC remain unclear. We aimed to provide insight into HCC induced with HepG2 cells and identify genes and pathways associated with HCC, as well as potential therapeutic targets.MethodsDataset GSE72581 was downloaded from the Gene Expression Omnibus, including samples from mice injected in liver parenchyma with HepG2 cells, and from mice injected with cells from patient tumor explants. Differentially expressed genes (DEGs) between the two groups of mice were analyzed. Then, gene ontology and Kyoto Encyclopedia of Gene and Genomes pathway enrichment analyses were performed. The MCODE plug-in in Cytoscape was applied to create a protein–protein interaction (PPI) network of DEGs.ResultsWe identified 1,405 DEGs (479 upregulated and 926 downregulated genes), which were enriched in complement and coagulation cascades, peroxisome proliferator-activated receptor signaling pathway, and extracellular matrix–receptor interaction. The top 4 modules and top 20 hub genes were identified from the PPI network, and associations with overall survival were determined using Kaplan–Meier analysis.ConclusionThis preclinical study provided data on molecular targets in HCC that could be useful in the clinical treatment of HCC.

P0011THE ROLE OF AQUAPORIN-11 (AQP11) IN THE THYMUS DEVELOPMENT

Abstract Background and Aims Some aquaporins transport not only water but also small non-ionic molecules such as glycerol. In fact, aquaporin-9 (AQP9) has been shown to transport glycerol which is critical to support memory T cell survival through metabolic fitness (Cui G et al. Cell. 161:750, 2015). As AQP11 is widely expressed and transport glycerol as well as water, AQP11 may also play a role in immunological system, which will expand the repertoire of the aquaporin research field. Method The AQP11 expression in the thymus was examined by RT-PCR, Western blot and immunohistochemistry in mice. Phenotypic analysis and microarray analysis of the thymus were conducted in wild and AQP11 null mice at 21 day old before the development of uremia due to polycystic kidneys. Results Both mRNA and protein expressions of AQP11 in the thymus were higher than those of the kidney by RT-PCR and Western blot. Interestingly, the size of the thymus from AQP11 null mice was smaller than that of the wild mice: 28mg vs. 56mg, even after the correction by the body weight: 0.59 % vs. 0.82 %, as the body size of AQP11 null mice was smaller. The vacuolated medullary epithelial cells were observed in the thymus of AQP11 null mice with narrowed cortex. The immunohistochemical analysis revealed the AQP11 expression at the stromal-epithelial cells in the thymus. The microarray analysis of the gene expression in the thymus was compared between the wild and AQP11 null thymus by the annotation analysis based on the David Bioinformatics Resources 6.8 (beta). The up-regulated 66 genes more than 1.5 folds in AQP11 null thymus are mainly related to the PI3K/Akt signaling pathway to promote metabolism, proliferation, cell survival, growth and angiogenesis. On the other hand, the down-regulated 55 genes less than half in AQP11 null thymus are related to energy production and the peroxisome proliferator-activated receptor (PPAR) signaling pathway. Further RT-qPCR analysis confirmed the enhanced expression of Egfr (Epidermal Growth Factor Receptor), Itgb4 (Integrin beta-4) and Il2ra (interleukin 2 receptor alpha) and the diminished expression of aquaglyceroporin AQP7, Pck1 (Phosphoenolpyruvate carboxy-kinase 1) and Ucp1 (Mitochondrial uncoupling protein 1). The up-regulated genes for growth signaling was unexpected with the smaller thymus but may support the survival of the hypoplastic thymus as a compensation. On the other hand, the down-regulated genes may compromise fat-glucose-energy metabolism in the thymus leading to the smaller thymus, which may be aggravated by the decreased expression of AQP7, another glycerol channel. Conclusion AQP11 may play an important role in the metabolic control of the developing thymus possibly through its glycerol transport. The smaller thymus with narrower cortex in AQP11 null mice may lead to immunological dysfunction, which is currently under study.

Abstract C026: Lack of HER4 signaling predicts poor prognosis among triple-negative breast cancer patients of African descent: A multi-institutional study

Abstract Triple-negative breast cancer (TNBC) disproportionately affects African-American (AA) women. Literature underscores that women from West Africa exhibit higher TNBC incidence and mortality rates than AA women. Distinctions in inherent tumor biology between the races have been speculated to underlie this global disparate burden. We conducted a multi-institutional study in which we analyzed differences in expression of BC-related immunohistochemical biomarkers between self-reported European, EA, AA, and African TNBC patients treated at Nottingham University in Nottingham, UK, Emory University in Atlanta, GA, and Olabisi Onabanjo University Teaching Hospital in Sagamu, Nigeria, respectively. We discovered highly significant differences in expression of the members of the HER family, HER1/EGFR, HER3 and HER4, between the racial groups (p&amp;lt;0.0001). HER4 and a summation of EGFR and HER4 (EGFR-HER4) scores decreased with increasing self-reported African ancestry. Gene expression analysis of The Cancer Genome Atlas (TCGA) publicly available dataset revealed that the genes encoding EGFR (ERBB1) and HER4 (ERBB4) were expressed less among AA compared to EA TNBC samples (p&amp;lt;0.05). A lack of HER4 expression correlated with high Nottingham grade (p=0.03) and mitotic index (p=0.03) among AA patients and high Ki-67 (p=0.04) among early-stage AA patients. Furthermore, low combined EGFR-HER4 expression was associated with low nuclear AR expression (p=0.03) among early-stage AA patients. Among both AA and African patients, low HER4 expression predicted significantly shorter 5-year overall survival (OS) (p=0.001) in Kaplan-Meier analyses. In multivariate models, low EGFR-HER4 score predicted shorter 10-year OS (p=0.03; HR: 0.03; 95% CI:0.001-0.76) and disease-free survival (p=0.04; HR: 0.03; 95% CI:0.001-0.80) among non-chemotherapy treated AA patients. In the TCGA dataset, we also observed downregulation of the EGFR but upregulation of the Notch signaling pathways to be more prevalent among AA compared to EA TNBC patients. Furthermore, peroxisome proliferator-activated receptor (PPAR) signaling was downregulated more among TNBC patients with low compared to high combined EGFR-HER4 scores (p=0.036). These results suggest that HER4 signaling differs among biogeographically distinct TNBC patients and that lack of HER4 and EGFR-HER4 expression may predict more aggressive disease among AA and indigenous African TNBC patient populations. Our findings also suggest that TNBC patients of African descent with low HER4 and low EGFR-HER4 scores overexpress members of the Notch and underexpress members of the PPAR signaling pathways, with potential therapeutic value. Citation Format: Nikita Wright, Chaeyun Lee, Uma Krishnamurti, Xiaoxian Li, Bikram Sahoo, Andrew Green, Ian Ellis, Ayodeji Agboola, Guanhao Wei, Lauren McCullough, Emad Rakha, Padmashree C.G. Rida, Remus Osan, Ritu Aneja. Lack of HER4 signaling predicts poor prognosis among triple-negative breast cancer patients of African descent: A multi-institutional study [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C026.

Integrated Analysis of Three Publicly Available Gene Expression Profiles Identified Genes and Pathways Associated with Clear Cell Renal Cell Carcinoma.

BackgroundAlthough advances have been achieved in the therapy of clear cell renal cell carcinoma (ccRCC), the pathogenesis of ccRCC is not yet fully understood. This study aimed to explore the critical genes and pathways associated with ccRCC by meta-analysis.Material/MethodsWe performed an integrated analysis of 3 publicly available microarray datasets developed from ccRCC tumor samples and normal tissues. A list of overlapped differentially expressed genes (DEGs) with the consistent expression trend in ccRCC tumor samples were identified, for which the protein–protein interaction (PPI) network was constructed, followed by topology structure and module analysis. The microRNA (miRNA) regulatory network and ccRCC associated pathway network were reconstructed.ResultsA total of 504 genes were found to be consistently and differentially regulated based on 3 microarray datasets. The overrepresented pathways for DEGs included citric acid cycle (TCA cycle) and peroxisome proliferator-activated receptor (PPAR) signaling pathway and cell cycle. The PPI network was clustered into 6 modules that were closely related with the M phase, desmosome assembly, and response to hormone stimulus. The hsa04110: cell cycle and hsa04510: focal adhesion were the significant pathways associated with ccRCC overlapped with enrichment analysis. KDR and ITGB4 were focal-adhesion-associated genes, which were regulated by has-miR-424 and has-miR-204, respectively. CCND2 and CCNA2 were cell-cycle-associated genes, which were regulated by hsa-miR-324-3p, hsa-miR-146a and hsa-miR-145.ConclusionsCell cycle and focal adhesion were dysregulated in ccRCC, which were associated with the expression of CCND2, ITGB4, KDR, and CCNA2 genes. The deregulation of pathways and associated genes may provide insights to ccRCC research and therapy.

Oxylipin Profiles in Plasma of Patients with Wilson's Disease.

Wilson’s disease (WD) is a rare autosomal recessive metabolic disorder resulting from mutations in the copper-transporting, P-type ATPase gene ATP7B gene, but influences of epigenetics, environment, age, and sex-related factors on the WD phenotype complicate diagnosis and clinical manifestations. Oxylipins, derivatives of omega-3, and omega-6 polyunsaturated fatty acids (PUFAs) are signaling mediators that are deeply involved in innate immunity responses; the regulation of inflammatory responses, including acute and chronic inflammation; and other disturbances related to any system diseases. Therefore, oxylipin profile tests are attractive for the diagnosis of WD. With UPLC-MS/MS lipidomics analysis, we detected 43 oxylipins in the plasma profiles of 39 patients with various clinical manifestations of WD compared with 16 healthy controls (HCs). Analyzing the similarity matrix of oxylipin profiles allowed us to cluster patients into three groups. Analysis of the data by VolcanoPlot and partial least square discriminant analysis (PLS-DA) showed that eight oxylipins and lipids stand for the variance between WD and HCs: eicosapentaenoic acid EPA, oleoylethanolamide OEA, octadecadienoic acids 9-HODE, 9-KODE, 12-hydroxyheptadecatrenoic acid 12-HHT, prostaglandins PGD2, PGE2, and 14,15-dihydroxyeicosatrienoic acids 14,15-DHET. The compounds indicate the involvement of oxidative stress damage, inflammatory processes, and peroxisome proliferator-activated receptor (PPAR) signaling pathways in this disease. The data reveal novel possible therapeutic targets and intervention strategies for treating WD.

Integrative transcriptome analysis and discovery of signaling pathways involved in the protective effects of curcumin against oxidative stress in tilapia hepatocytes

Summer outbreaks of the hepatobiliary syndrome in fish impose a heavy burden on aquaculture in China. Curcumin is a polyphenol with antioxidant activity that has been used to protect the health of fish livers, but the mechanism underlying its protective effect is unclear. In this study, an in vitro model of hepatocyte oxidative damage in Oreochromis niloticus was established using H2O2. Treatment with 5 mM H2O2 for 2.5 h markedly reduced cell viability and antioxidant activity and elevated lactate dehydrogenase (LDH) activity, indicating conditions that can be used to establish an oxidative stress model. Under H2O2 stress, curcumin pretreatment significantly maintained cell viability, reduced malondialdehyde (MDA) levels, and increased superoxide dismutase (SOD) activity. RNA-seq results showed that acute H2O2 treatment resulted in minor changes in gene expression, whereas curcumin changed the expression profile and affected cytochrome P450 (Cyp 450), glutathione (GSH) metabolism, and the peroxisome proliferator-activated receptor (PPAR) signaling pathway. Several critical antioxidant defense signaling pathways were identified, and altered expression was confirmed by q-PCR. These results indicate that curcumin might upregulate PPAR expression by increasing Cyp2J2 expression. Further experiments showed that curcumin can upregulate the Nrf2-Keap1 signaling pathway at the transcriptional level, and this upregulation can induce downstream defense genes, including glutamate cysteine ligase catalytic subunit(GCLC) and glutamate cysteine ligase modifier subunit (GCLM), and thereby promote GSH synthesis and the expression of related antioxidases. This study might shed light on the effects of curcumin on the prevention and alleviation of liver diseases in fish.

Genetic variants of the peroxisome proliferator-activated receptor (PPAR) signaling pathway genes and risk of pancreatic cancer.

Because the peroxisome proliferator-activated receptor (PPAR) signaling pathway is involved in development and progression of pancreatic cancer, we investigated associations between genetic variants of the PPAR pathway genes and pancreatic cancer risk by using three published genome-wide association study datasets including 8477 cases and 6946 controls of European ancestry. Expression quantitative trait loci (eQTL) analysis was also performed for correlations between genotypes of the identified genetic variants and messenger RNA (mRNA) expression levels of their genes by using available databases of the 1000 Genomes, TCGA, and GTEx projects. In the single-locus logistic regression analysis, we identified 1141 out of 17 532 significant single-nucleotide polymorphisms (SNPs) in 112 PPAR pathway genes. Further multivariate logistic regression analysis identified three independent, potentially functional loci (rs12947620 in MED1, rs11079651 in PRKCA, and rs34367566 in PRKCB) for pancreatic cancer risk (odds ratio [OR] = 1.11, 95% confidence interval [CI], [1.06-1.17], P = 5.46 × 10-5 ; OR = 1.10, 95% CI, [1.04-1.15], P = 1.99 × 10-4 ; and OR = 1.09, 95% CI, [1.04-1.14], P = 3.16 × 10-4 , respectively) among 65 SNPs that passed multiple comparison correction by false discovery rate (< 0.2). When risk genotypes of these three SNPs were combined, carriers with 2 to 3 unfavorable genotypes (NUGs) had a higher risk of pancreatic cancer than those with 0 to 1 NUGs. The eQTL analysis showed that rs34367566 A>AG was associated with decreased expression levels of PRKCB mRNA in 373 lymphoblastoid cell lines. Our findings indicate that genetic variants of the PPAR pathway genes, particularly MED1, PRKCA, and PRKCB, may contribute to susceptibility to pancreatic cancer.

Synergic effect of combined intervention with clindamycin and PPARγ agonist in an HLA-II mouse model of Group A Streptococcal Necrotizing Fasciitis

Abstract Group A Streptococcus (GAS, Streptococcus pyogenes) is an important human pathogen that can cause a broad spectrum of diseases ranging from self-limiting pharyngitis and impetigo to deeper, life-threatening invasive infections such as streptococcal toxic shock syndrome and necrotizing fasciitis (NF). An overarching pro-inflammatory cytokine storm and a rapidly progressive tissue destruction lead to significant morbidity and lethal outcomes of GAS NF. Transcriptome profiling of uninfected and GAS infected skin from HLA-II transgenic mouse models of GAS NF revealed strong activation of inflammatory signaling and inhibition of peroxisome proliferator-activated receptor (PPAR) signaling pathways. Specifically, PPARgamma (PPARγ), a lipid ligand-activated transcription factor driving adipogenic and anti-inflammatory effects, was a significantly inhibited upstream regulator and this inhibition was reflected in downregulation of PPARγ-dependent genes. So far, there are no reports on the role of PPARγ in GAS infections. Here, we explored the potential use of the PPARγ selective synthetic agonist, pioglitazone (PZ), in combination with clindamycin (CLN), as a combined therapeutic approach in vivo in an HLA-II mouse model of GAS NF. Although the mechanism of synergy is not understood, our data demonstrate that combined CLN PZ intervention offers significant advantages over treatment with CLN alone, and uncover a new role for PPARγ in attenuating skin lesions, GAS burden, IL-6 and IFN-γ levels, and weight loss during GAS NF. To our knowledge, this is the first report to demonstrate the benefits of a combined host- and pathogen-directed treatment approach to ameliorate severity and inflammation during GAS NF.

Gan-Jiang-Ling-Zhu decoction alleviates hepatic steatosis in rats by the miR-138-5p/CPT1B axis

BackgroundNon-alcoholic fatty liver disease (NAFLD) is a commonly-encountered chronic liver disease which lacks verified pharmacological interventions. Gan-Jiang-Ling-Zhu decoction (GJLZ) is a classic formula utilized in clinical practice. In this study, we aimed to evaluate the therapeutic effect of GJLZ in NAFLD and explore the possible underlying mechanisms. MethodsTwenty-four rats were randomly divided into three groups: normal group, fed with chow diet for 8 weeks; model group, fed with high fat diet for 8 weeks; and GJLZ group, initially fed HFD for 4 weeks, and then administered the GJLZ decoction for 4 weeks by oral gavage while continuously feeding HFD. Rats were sacrificed after the intervention, and liver tissues and blood samples were harvested. Liver steatosis was detected by HE and Oil Red O staining. Body weight and liver index were analyzed. Liver triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL), serum almandine aminotransferase (ALT), aspartate aminotransferase (AST), and nonesterified fatty acid (NEFA) were assayed using commercial kits. Differentially expressed genes were identified by RNA-sequencing and verified using real-time PCR (RT-PCR) and western blotting. Whole miRNAs were detected by RNA-sequence analysis, and mRNA-targeted miRNAs were verified by RT-PCR. The miRNA-mRNA regulation pattern was confirmed using the dual-luciferase reporter assay. ResultsTreatment with GJLZ significantly improved hepatic steatosis and inflammation, reduced liver index and liver TG content, and also significantly reduced serum ALT and AST levels. Based on the results of RNA-sequence analysis, five differentially expressed genes (DEGs) in the peroxisome proliferator-activated receptor (PPAR) signaling pathway were recognized. RT-PCR confirmed that carnitine palmitoyltransferase 1b (CPT1B) expression was significantly regulated by GJLZ treatment. GJLZ decoction intervention also increased significantly hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA) expression. Next, miRNA profiling and screening were performed based on CPT1B alteration. Rno-miR-138-5p likely responded to GJLZ intervention, and rno-miR-138-5p inhibitor increased CPT1B expression while rno-miR-138-5p mimic reduced CPT1B expression. When CPT1B mutated, miR-138-5p mimic and inhibitor could not regulate the luciferase activity of CPT1B. ConclusionsGJLZ is an effective formula for NAFLD management, and its possible mechanism of action involves the regulation of CPT1B expression via rno-miR-138-5p.

A novel metformin derivative showed improvement of lipid metabolism in obese rats with type 2 diabetes.

In this study, we investigated the lipid metabolism regulatory activity of a novel metformin derivative (MD568) and its potential mechanism of action in obese rats with type 2 diabetes mellitus (T2 DM). Previous gene chip analysis of 3T3-L1 cells have shown that MD568 regulates the transcription of genes involved in the peroxisome proliferator-activated receptor (PPAR) signalling pathway, fatty acid metabolism, and glycerolipid metabolism. In this study, obese T2 DM rats were treated with MD568 (200mg/kg) for 8weeks. Results showed that MD568 significantly reduced the body weight gain, plasma glucose, insulin, total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels. MD568 treatment also improved the insulin resistance of obese T2 DM model rats. In particular, in white adipose tissue, MD568 inhibited the excessive volume increment of adipose cells by down-regulating the protein levels of CCAAT/enhancer-binding protein-α (C/EBP-α) and PPAR-γ, as well as the transcription of their target lipid metabolism-related genes. In the liver, MD568 inhibited hepatic fatty lesions and interfered with hepatic gluconeogenesis by regulating the expression of lipid metabolism-related genes and glycogen-related kinases. In conclusion, our results suggest that the newly synthesized MD568 affects the maintenance of lipid homeostasis in obese type 2 diabetic rats.

Gene Expression Profiling of the Liver and Lung in Mice After Exposure to ZnO Quantum Dots.

IntroductionZnO quantum dots (QDs) have drawn much attention recently as they are Cd-free, low-cost, and have excellent optical properties. With the expanded production and application of ZnO nanoparticles, concerns about their potential toxicity have also been raised.Materials and MethodsWe used RNA sequencing (RNA-seq) to analyze the global gene expression of liver and lung tissues after ZnO QDs treatment. Differentially expressed genes (DEGs) were screened, with a fold change >1.5 and padj <0.05. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed, and padj <0.05 was considered significantly enriched. The RNA-seq results were validated by quantitative real-time polymerase chain reaction (qRT-PCR).ResultsA total of 47 and 218 genes were significantly differentially expressed in the liver and lung. Eight GO terms were enriched in the liver and lung, and retinol metabolism and the peroxisome proliferator-activated receptor (PPAR) signaling pathway were shared in different tissues.DiscussionAccording to DEGs and pathway enrichment analyses, inflammation might be induced in liver and lung tissues after intravenous injection of ZnO QDs. These findings will be helpful for future research and application of ZnO QDs.