PPARγ and Its Role in Cardiovascular Diseases

C/VDdb: A multi-omics expression profiling database for a knowledge-driven approach in cardiovascular disease (CVD)

The cardiovascular disease (C/VD) database is an integrated and clustered information resource that covers multi-omic studies (microRNA, genomics, proteomics and metabolomics) of cardiovascular-related traits with special emphasis on coronary artery disease (CAD). This resource was built by mining existing literature and public databases and thereafter manual biocuration was performed. To enable integration of omic data from distinct platforms and species, a specific ontology was applied to tie together and harmonise multi-level omic studies based on gene and protein clusters (CluSO) and mapping of orthologous genes (OMAP) across species. CAD continues to be a leading cause of death in the population worldwide, and it is generally thought to be an age-related disease. However, CAD incidence rates are now known to be highly influenced by environmental factors and interactions, in addition to genetic determinants. With the complexity of CAD aetiology, there is a difficulty in research studies to elucidate general elements compared to other cardiovascular diseases. Data from 92 studies, covering 13945 molecular entries (4353 unique molecules) is described, including data descriptors for experimental setup, study design, discovery-validation sample size and associated fold-changes of the differentially expressed molecular features (p-value<0.05). A dedicated interactive web interface, equipped with a multi-parametric search engine, data export and indexing menus are provided for a user-accessible browsing experience. The main aim of this work was the development of a data repository linking clinical information and molecular differential expression in several CVD-related traits from multi-omics studies (genomics, transcriptomics, proteomics and metabolomics). As an example case of how to query and identify data sets within the database framework and concomitantly demonstrate the database utility, we queried CAD-associated studies and performed a systems-level integrative analysis. URL: www.padb.org/cvd

Potentially critical roles of TNPO1, RAP1B, ZDHHC17, and PPM1B in the progression of coronary atherosclerosis through microarray data analysis

OBJECTIVE

This study aimed to identify more potentially critical genes associated with atherosclerotic coronary artery disease (CAD).

MATERIALS AND METHODS

Gene expression profile of GSE12288 was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were screened in atherosclerotic CAD samples compared with controls, followed by weighed gene coexpression network analysis (WGCNA) by which the most significant module was identified. Gene coexpression network was constructed based on genes in the most significant module, and functional annotation was also performed. In addition, microRNAs (miRNAs) that were directly associated with CAD were screened from the literature, and the miRNA-target regulatory network was constructed based on genes in the most significant module, followed by Gene Ontology (GO) and pathway enrichment analysis. Furthermore, we used another data set of GSE42148 from the GEO database to perform data validation.

RESULTS

WGCNA analysis showed that the turquoise module may have the most important role in atherosclerotic CAD. Genes in this module were involved in translational elongation and intracellular signal transduction. Besides, we identified five confirmed CAD-related miRNAs. TNPO1, RAP1B, and ZDHHC17 could be targeted by four of these miRNAs. Genes such as PPM1B could be regulated by three miRNAs. Moreover, TNPO1 and ZDHHC17 were involved in the GO terms associated with protein localization and transport and the immune system; RAP1B and PPM1B were linked with intracellular signal transduction-related pathways. In addition, PPM1B and ZDHHC17 had accordantly significant expression changes in another data set GSE42148.

CONCLUSION

TNPO1, RAP1B, ZDHHC17, and PPM1B may play essential roles in the progression of coronary atherosclerosis.

Fucosterol Protects against Concanavalin A-Induced Acute Liver Injury: Focus on P38 MAPK/NF-κB Pathway Activity

Objective

Fucosterol is derived from the brown alga Eisenia bicyclis and has various biological activities, including antioxidant, anticancer, and antidiabetic properties. The aim of this study was to investigate the protective effects of fucosterol pretreatment on Concanavalin A- (ConA-) induced acute liver injury in mice, and to understand its molecular mechanisms.

Materials and Methods

Acute liver injury was induced in BALB/c mice by ConA (25 mg/kg), and fucosterol (dissolved in 2% DMSO) was orally administered daily at doses of 25, 50, and 100 mg/kg. The levels of hepatic necrosis, apoptosis, and autophagy associated with inflammatory cytokines were measured at 2, 8, and 24 h.

Results

Fucosterol attenuated serum liver enzyme levels and hepatic necrosis and apoptosis induced by TNF-α, IL-6, and IL-1β. Fucosterol also inhibited apoptosis and autophagy by upregulating Bcl-2, which decreased levels of functional Bax and Beclin-1. Furthermore, reduced P38 MAPK and NF-κB signaling were accompanied by PPARγ activation.

Conclusion

This study showed that fucosterol could alleviate acute liver injury induced by ConA by inhibiting P38 MAPK/PPARγ/NF-κB signaling. These findings highlight that fucosterol is a promising potential therapeutic agent for acute liver injury.

SHORT CHAIN FATTY ACIDS UPREGULATE ADIPOKINE PRODUCTION IN TYPE 2 DIABETES-DERIVED HUMAN ADIPOCYTES

PURPOSE

Short chain fatty acids (SCFAs) play a major regulatory role in adipocyte function and metabolism. The aim of this study was to investigate the effects of SCFAs on adiponectin and leptin expression in adipocytes, and also to determine whether the effects of SCFA treatment in visceral adipocytes obtained from healthy subjects are different relative to the effects in adipocytes from patients with type 2 diabetes.

MATERIALS AND METHODS

Human pericardiac preadipocytes and human pericardiac preadipocytes type 2 diabetes were differentiated into adipocytes for 21 days in 48-well plates. After differentiation, two kinds of mature adipocytes, human pericardiac adipocytes (HPAd) and human pericardiac adipocytes-type 2 diabetes (HPAd-T2D) were incubated with or without 1 mM of acetic acid (AA), butyrate acid (BA), and propionic acid (PA). After 48 hours of incubation, intracellular lipid accumulation was measured using oil red staining. In addition, mRNA levels of adiponectin, leptin and Peroxisome Proliferator-Activated Receptor γ (PPARγ) were determined by Real-Time PCR system.

RESULTS

In HPAd, SCFA supplementation did not inhibit lipid accumulation. By contrast, both AA (p<0.01) and PA (p<0.01) significantly inhibited lipid accumulation in HPAd-T2D. Regarding mRNA levels of adiponectin, no significant changes were found in HPAd, while all three types of SCFAs significantly increased (p<0.05) adiponectin expression in HPAd-T2D. Leptin mRNA expression levels were significantly increased by treatment with all three types of SCFAs in both HPAd (p<0.05) and HPAd-T2D (p<0.05).

CONCLUSION

SCFAs inhibited lipid droplet accumulation and increased mRNA expression of adiponectin and leptin in T2D-derived adipocytes.

Interplay between the renin-angiotensin system, the canonical WNT/β-catenin pathway and PPARγ in hypertension

PURPOSE OF REVIEW

Heterogeneous causes can determinate hypertension.

RECENT FINDINGS

The renin-angiotensin system (RAS) has a major role in the pathophysiology of blood pressure. Angiotensin II and aldosterone are overexpressed during hypertension and lead to hypertension development and its cardiovascular complications. In several tissues, the overactivation of the canonical WNT/β-catenin pathway leads to inactivation of peroxisome proliferator-activated receptor gamma (PPARγ), while PPARγ stimulation induces a decrease of the canonical WNT/β-catenin pathway. In hypertension, the WNT/β-catenin pathway is upregulated, whereas PPARγ is decreased. The WNT/β-catenin pathway and RAS regulate positively each other during hypertension, whereas PPARγ agonists can decrease the expression of both the WNT/β-catenin pathway and RAS. We focus this review on the hypothesis of an opposite interplay between PPARγ and both the canonical WNT/β-catenin pathway and RAS in regulating the molecular mechanism underlying hypertension. The interactions between PPARγ and the canonical WNT/β-catenin pathway through the regulation of the renin-angiotensin system in hypertension may be an interesting way to better understand the actions and the effects of PPARγ agonists as antihypertensive drugs.

Demyelination in Multiple Sclerosis: Reprogramming Energy Metabolism and Potential PPARγ Agonist Treatment Approaches

Demyelination in multiple sclerosis (MS) cells is the site of several energy metabolic abnormalities driven by dysregulation between the opposed interplay of peroxisome proliferator-activated receptor γ (PPARγ) and WNT/β-catenin pathways. We focus our review on the opposing interactions observed in demyelinating processes in MS between the canonical WNT/β-catenin pathway and PPARγ and their reprogramming energy metabolism implications. Demyelination in MS is associated with chronic inflammation, which is itself associated with the release of cytokines by CD4⁺ Th17 cells, and downregulation of PPARγ expression leading to the upregulation of the WNT/β-catenin pathway. Upregulation of WNT/β-catenin signaling induces activation of glycolytic enzymes that modify their energy metabolic behavior. Then, in MS cells, a large portion of cytosolic pyruvate is converted into lactate. This phenomenon is called the Warburg effect, despite the availability of oxygen. The Warburg effect is the shift of an energy transfer production from mitochondrial oxidative phosphorylation to aerobic glycolysis. Lactate production is correlated with increased WNT/β-catenin signaling and demyelinating processes by inducing dysfunction of CD4⁺ T cells leading to axonal and neuronal damage. In MS, downregulation of PPARγ decreases insulin sensitivity and increases neuroinflammation. PPARγ agonists inhibit Th17 differentiation in CD4⁺ T cells and then diminish release of cytokines. In MS, abnormalities in the regulation of circadian rhythms stimulate the WNT pathway to initiate the demyelination process. Moreover, PPARγ contributes to the regulation of some key circadian genes. Thus, PPARγ agonists interfere with reprogramming energy metabolism by directly inhibiting the WNT/β-catenin pathway and circadian rhythms and could appear as promising treatments in MS due to these interactions.

PPARγ Pro12Ala and C161T polymorphisms in patients with acne vulgaris: Contribution to lipid and lipoprotein profile

PURPOSE

The aim of present study was to clarify the role of peroxisome proliferator-activated receptor γ (PPARγ) Pro12Ala and C161T variants in the pathogenesis of acne vulgaris (AV) and their influence on lipid and lipoprotein profile.

METHODS

The present case-control study consisted of 393 individuals including 198 patients with AV (mild-, moderate-, and severe-AV) and 195 unrelated age-matched healthy individuals from Western Iran. The PPARγ Pro12Ala and C161T polymorphisms were identified using polymerase chain reaction-restriction length polymorphism method. Also, serum lipid and lipoprotein profile and fasting blood sugar (FBS) were detected in studied individuals.

RESULTS

In women patients with AV significantly higher serum levels of FBS, total cholesterol, low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol compared to healthy women were detected. Neither PPARγ Pro12Ala nor C161T polymorphism was associated with the risk of AV but the Pro allele was a risk factor for AV among all men and women patients ≥20years. The variant genotype of PPARγ CG (Pro/Ala) was associated with significantly higher levels of total cholesterol and triglycerides compared to CC (Pro/Pro) genotype. We detected a significantly lower level of FBS in the presence of CT+TT genotype of PPARγ C161T compared to CC genotype. Also, carriers of PPARγ TT genotype had significantly lower serum level of total cholesterol and LDL-C compared to CC genotype.

CONCLUSIONS

Our results demonstrated the association of PPARγ Pro allele with susceptibility to AV in patients ≥20years and the influence of PPARγ Pro12Ala and C161T polymorphisms on the lipid and lipoprotein profile.

Insights on Localized and Systemic Delivery of Redox-Based Therapeutics

Reactive oxygen and nitrogen species are indispensable in cellular physiology and signaling. Overproduction of these reactive species or failure to maintain their levels within the physiological range results in cellular redox dysfunction, often termed cellular oxidative stress. Redox dysfunction in turn is at the molecular basis of disease etiology and progression. Accordingly, antioxidant intervention to restore redox homeostasis has been pursued as a therapeutic strategy for cardiovascular disease, cancer, and neurodegenerative disorders among many others. Despite preliminary success in cellular and animal models, redox-based interventions have virtually been ineffective in clinical trials. We propose the fundamental reason for their failure is a flawed delivery approach. Namely, systemic delivery for a geographically local disease limits the effectiveness of the antioxidant. We take a critical look at the literature and evaluate successful and unsuccessful approaches to translation of redox intervention to the clinical arena, including dose, patient selection, and delivery approach. We argue that when interpreting a failed antioxidant-based clinical trial, it is crucial to take into account these variables and importantly, whether the drug had an effect on the redox status. Finally, we propose that local and targeted delivery hold promise to translate redox-based therapies from the bench to the bedside.

Qiliqiangxin attenuates isoproterenol-induced cardiac remodeling in mice

BACKGROUND

To further explore the role of PPARγ in QL treatment, ISO-induced mice model and following methods were established.

METHODS

Cardiac remodeling on mice model was induced by isoproterenol (ISO) infusion or saline infusion as control for two weeks then divided into 4 groups, after that divided in 5 different treatment methods to investigate the role of PPARγ in QL therapy. Echocardiography and Masson's trichrome staining were respectively used to determine cardiac function and fibrosis. Immunoblotting was applied to evaluate the expression levels of proliferator-activated receptor-γ (PPARγ), Bax, Bcl, phospho-Akt (Ser473), Akt, phospho-P38 and P38, phosphor-ERK and ERK.

RESULTS

QL treatment improved left ventricular function, decreased apoptosis, and prevented myocardial fibrosis at the same time. Meanwhile, the PPARγ level was elevated with QL treatment in ISO-injected mice hearts. Inhibition of PPARγ activity blocked the protective effects of QL, while the activator of PPARγ did not provide additional benefit. Specifically, the results indicated a decline in PPARγ in ISO-infused mice and QL decreased the toxicity of ISO by improving the level of PPARγ.

CONCLUSIONS

Our study demonstrated that QL treatment provided cardioprotection against ISO-induced cardiac remodeling by improving PPARγ level, which could be as the potential therapeutic target in reversing cardiac remodeling and heart failure.

The novel ZIP4 regulation and its role in ovarian cancer

Our RNAseq analyses revealed that ZIP4 is a top gene up-regulated in more aggressive ovarian cancer cells. ZIP4's role in cancer stem cells has not been reported in any type of cancer. In addition, the role and regulation of ZIP4, a zinc transporter, have been studied in the context of extracellular zinc transporting. Factors other than zinc with ZIP4 regulatory effects are essentially unknown. ZIP4 expression and its regulation in epithelial ovarian cancer cells was assessed by immunoblotting, quantitative PCR, or immunohistochemistry staining in human ovarian tissues. Cancer stem cell-related activities were examined to evaluate the role of ZIP4 in human high-grade serous ovarian cancer cells in vitro and in vivo. RNAi and CRISPR techniques were used to knockdown or knockout ZIP4 and related genes. Ovarian cancer tissues overexpressed ZIP4 when compared with normal and benign tissues. ZIP4 knockout significantly reduced several cancer stem cell-related activities in EOC cells, including proliferation, anoikis-resistance, colony-formation, spheroid-formation, drug-resistance, and side-population in vitro. ZIP4-expressing side-population highly expressed known CSC markers ALDH1 and OCT4. ZIP4 knockout dramatically reduced tumorigenesis and ZIP4 overexpression increased tumorigenesis in vivo. In addition, the ZIP4-expressing side-population had the tumor initiating activity. Moreover, the oncolipid lysophosphatic acid effectively up-regulated ZIP4 expression via the nuclear receptor peroxisome proliferator-activated receptor gamma and lysophosphatic acid 's promoting effects in cancer stem cell-related activities in HGSOC cells was at least partially mediated by ZIP4 in an extracellular zinc-independent manner. Our critical data imply that ZIP4 is a new and important cancer stem cell regulator in ovarian cancer. Our data also provide an innovative interpretation for the apparent disconnection between low levels of zinc and up-regulation of ZIP4 in ovarian cancer tissues.

Yixinshu ameliorates hippocampus abnormality induced by heart failureviathe PPARγ signaling pathway

Yizinshu (YXS) improves cardiac function and ameliorates hippocampus abnormality induced by heart failureviathe PPARγ signaling pathway.