Significance of peroxisome proliferator-activated receptors in the cardiovascular system in health and disease

The Role of NF-κB, PPAR-α, and PPAR-γ in Older Adults with Metabolic Syndrome

The etiopathogenesis of metabolic syndrome (MetS) has not been fully understood yet, and chronic low-grade inflammation is thought to be associated with the development of complications related to MetS. We aimed to investigate the role of Nuclear factor Kappa B ( NF-κB ), Peroxisome Proliferator-Activated Receptor- α and γ (PPAR-α, and PPAR-γ) which are the main markers of inflammation in older adults with MetS. A total of 269 patients aged≥18, 188 patients with MetS who met the diagnostic criteria of the International Diabetes Federation, and 81 controls who applied to geriatrics and general internal medicine outpatient clinics for various reasons were included in the study. Patients were separated into four groups: young with MetS (< 60, n=76), elderly with MetS (≥60, n=96), young control (< 60, n=31), elderly controls (≥60, n=38). Carotid intima-media thickness (CIMT) and NF-κB , PPAR-α, and PPAR-γ plasma levels were measured in all of the participants. Age and sex distribution were similar between MetS and control groups. C-reactive protein (CRP), NF-κB levels (p=0.001) and CIMT (p<0,001) of MetS group were significantly higher than in the control groups. On the other hand, the PPAR-γ (p=0.008) and PPAR-α (p=0.003) levels were significantly lower in MetS. ROC analysis revealed that the NF-κB, PPAR-α, and PPAR-γ could be used to indicate MetS in younger adults (AUC: 0.735, p<0.000; AUC: 0.653, p=0.003), whereas it could not be an indicator in older adults (AUC: 0.617, p=0.079; AUC:0.530, p=0.613). It seems that these markers have important roles in MetS-related inflammation. In our results, suggest that the indicator feature of NF-κB , PPAR-α and PPAR-γ in recognizing MetS in young individuals is lost in older adults with Mets.

The relationship between perfluoroalkyl substances and hypertension: A systematic review and meta-analysis

Hypertension is an important risk factor for cardiovascular diseases (CVDs) and a leading cause of premature death. Epidemiological studies have found that perfluoroalkyl substances (PFASs) are associated with hypertension. However, the correlation between PFASs and hypertension has not been systematically reported. Based on evidence from population epidemiological surveys, we conducted a meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to assess the correlation between PFASs exposure and hypertension. In this study, three databases of PubMed, Web of science, Embase were searched and 13 literatures with 81,096 participants were included. Literature heterogeneity was evaluated by I² statistic, and the random effect model (I² > 50%) and fixed effect model (I² < 50%) were used to combine the studies in meta-analysis. The results showed that PFNA (OR = 1.11, 95% CI: 1.04-1.19), PFOA (OR = 1.12, 95% CI: 1.02-1.23), PFOS (OR = 1.19, 95% CI: 1.06-1.34) and PFHxS (OR = 1.03, 95% CI: 1.00-1.06) were significantly associated with hypertension, while other types of PFASs (∑PFAS, PFDA, PFUnDA) had no statistical significance. In addition, PFNA (OR = 1.12, 95% CI: 1.03-1.22), PFOA (OR = 1.12, 95% CI: 1.01-1.25) and PFOS (OR = 1.12, 95% CI: 1.00-1.25) exposure were positively correlated with the risk of hypertension in men, but not in women. Our study reveals that PFASs are risk factors for hypertension, with notable gender differences observed in PFASs-exposed populations. Specifically, males exposed to PFNA, PFOA, and PFOS exhibit a higher risk of hypertension compared to females. However, further investigations are needed to delve into the precise mechanism through which PFASs contribute to the development of hypertension.

The Yin and Yang Effect of the Apelinergic System in Oxidative Stress

Apelin is an endogenous ligand for the G protein-coupled receptor APJ and has multiple biological activities in human tissues and organs, including the heart, blood vessels, adipose tissue, central nervous system, lungs, kidneys, and liver. This article reviews the crucial role of apelin in regulating oxidative stress-related processes by promoting prooxidant or antioxidant mechanisms. Following the binding of APJ to different active apelin isoforms and the interaction with several G proteins according to cell types, the apelin/APJ system is able to modulate different intracellular signaling pathways and biological functions, such as vascular tone, platelet aggregation and leukocytes adhesion, myocardial activity, ischemia/reperfusion injury, insulin resistance, inflammation, and cell proliferation and invasion. As a consequence of these multifaceted properties, the role of the apelinergic axis in the pathogenesis of degenerative and proliferative conditions (e.g., Alzheimer's and Parkinson's diseases, osteoporosis, and cancer) is currently investigated. In this view, the dual effect of the apelin/APJ system in the regulation of oxidative stress needs to be more extensively clarified, in order to identify new potential strategies and tools able to selectively modulate this axis according to the tissue-specific profile.

Qihuang Zhuyu Formula Attenuates Atherosclerosis via Targeting PPARγ to Regulate Cholesterol Efflux and Endothelial Cell Inflammation

At present, due to the limitations of drug therapy targets for atherosclerosis, some patients fail to achieve satisfactory efficacy. Cholesterol efflux dysfunction and endothelial cell inflammation are considered to be important factors in the development of atherosclerosis. Peroxisome proliferator-activated receptor gamma (PPARγ), a promising therapeutic target for atherosclerosis, plays a dual role in regulating cholesterol efflux and endothelial cell inflammation. However, the use of PPARγ agonist in clinical practice is greatly limited as it could lead to water and sodium retention and hence result in congestive heart failure. Qihuang Zhuyu Formula (QHZYF) is a hospital preparation of Jiangsu Province Hospital of Chinese Medicine which has definite effect in the treatment of atherosclerosis, but its pharmacological mechanism has not been clear. In this study, we successfully predicted that QHZYF might regulate cholesterol efflux and endothelial inflammation via targeting PPARγ-mediated PPARγ/LXRα/ABCA1-ABCG1 and PPARγ/NF-κB p65 pathways by using UPLC-Q-TOF/MS, network pharmacology, bioinformatics analysis, and molecular docking technology. Subsequently, we confirmed in vivo that QHZYF could attenuate atherosclerosis in ApoE-/- mice and regulate the expression levels of related molecules in PPARγ/LXRα/ABCA1-ABCG1 and PPARγ/NF-κB p65 pathways of ApoE-/- mice and C57BL/6 wild-type mice. Finally, in in vitro experiments, we found that QHZYF could reduce lipid content and increase cholesterol efflux rate of RAW 264.7 cells, inhibit the inflammatory response of HUVECs, and regulate the expression levels of related molecules in the two pathways. In addition, the above effects of QHZYF were significantly weakened after PPARγ knockdown in the two kinds of cells. In conclusion, our study revealed that QHZYF attenuates atherosclerosis via targeting PPARγ-mediated PPARγ/LXRα/ABCA1-ABCG1 and PPARγ/NF-κB p65 pathways to regulate cholesterol efflux and endothelial cell inflammation. More importantly, our study offers a promising complementary and alternative therapy which is expected to make up for the limitation of current drug treatment methods and provide a valuable reference for new drugs development in the future.

Jujuboside A Ameliorates Myocardial Apoptosis and Inflammation in Rats with Coronary Heart Disease by Inhibiting PPAR-α Signaling Pathway

Background

Coronary heart disease (CHD) is a chronic disease caused by atherosclerosis (AS), which can cause myocardial ischemia, hypoxia, or necrosis, seriously threatening human health. There is an urgent need for effective treatments and drugs to reduce the various risk factors for coronary heart disease and relieve symptoms of angina pectoris and myocardial infarction in patients. Jujuboside A (JuA) is a triterpenoid saponin extracted from jujube seeds, which has various biological activities such as antioxidant, anti-inflammatory, antiapoptotic, and neuroprotective effects. We study the function of JuA in myocardial injury, dyslipidemia, and inflammation in the CHD rat model, to explore its potential mechanism of improving CHD.

Methods

A rat model of CHD was established by feeding a high-fat diet. The rats were randomly divided into 5 groups (n = 6): control group, CHD group, JuA 25 mg/kg group, JuA 50 mg/kg group, and JuA 75 mg/kg group. Echocardiography was used to detect the cardiac function parameters of rats in each group, and then, hematoxylin and eosin staining was used to assess the histopathological injury in myocardial tissues. Levels of blood lipids, myocardial injury indexes, and inflammatory factors of rats in each group were measured by biochemical tests and enzyme linked immunosorbent assay, and the levels of Bax, Bcl-2, c-caspase-3, PPAR-α, p65, p-p65, IκBα, and p-IκBα protein expression in myocardial tissues were detected by western blot.

Results

Compared with the CHD group, JuA therapy significantly improved injury in myocardial tissue and endothelial tissue. It also strengthened cardiac function, while decreasing total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol levels in the serum and increasing high-density lipoprotein cholesterol levels. In addition, JuA also restrained cardiomyocytes apoptosis and inhibited the inflammatory reaction by reducing TNF-α, IL-1β, and IL-6 expression in myocardial tissues. Furthermore, administration of JuA inhibited the activation of PPAR-α pathway by preventing the phosphorylation of p65 and IκBα in myocardial tissues of CHD rats.

Conclusion

JuA may improve cardiac function, alleviate myocardial and endothelial injury, and also ameliorate dyslipidemia and inflammatory reaction in rats with CHD, where JuA probably plays a protective role by inhibiting the activation of PPAR-α pathway.

Cardiomyocyte peroxisome proliferator-activated receptor α is essential for energy metabolism and extracellular matrix homeostasis during pressure overload-induced cardiac remodeling

Peroxisome proliferator-activated receptor α (PPARα), a ligand-activated nuclear receptor critical for systemic lipid homeostasis, has been shown closely related to cardiac remodeling. However, the roles of cardiomyocyte PPARα in pressure overload-induced cardiac remodeling remains unclear because of lacking a cardiomyocyte-specific Ppara-deficient (Ppara^ΔCM) mouse model. This study aimed to determine the specific role of cardiomyocyte PPARα in transverse aortic constriction (TAC)-induced cardiac remodeling using an inducible Ppara^ΔCM mouse model. Ppara^ΔCM and Ppara^fl/fl mice were randomly subjected to sham or TAC for 2 weeks. Cardiomyocyte PPARα deficiency accelerated TAC-induced cardiac hypertrophy and fibrosis. Transcriptome analysis showed that genes related to fatty acid metabolism were dramatically downregulated, but genes critical for glycolysis were markedly upregulated in Ppara^ΔCM hearts. Moreover, the hypertrophy-related genes, including genes involved in extracellular matrix (ECM) remodeling, cell adhesion, and cell migration, were upregulated in hypertrophic Ppara^ΔCM hearts. Western blot analyses demonstrated an increased HIF1α protein level in hypertrophic Ppara^ΔCM hearts. PET/CT analyses showed an enhanced glucose uptake in hypertrophic Ppara^ΔCM hearts. Bioenergetic analyses further revealed that both basal and maximal oxygen consumption rates and ATP production were significantly increased in hypertrophic Ppara^fl/fl hearts; however, these increases were markedly blunted in Ppara^ΔCM hearts. In contrast, hypertrophic Ppara^ΔCM hearts exhibited enhanced extracellular acidification rate (ECAR) capacity, as reflected by increased basal ECAR and glycolysis but decreased glycolytic reserve. These results suggest that cardiomyocyte PPARα is crucial for the homeostasis of both energy metabolism and ECM during TAC-induced cardiac remodeling, thus providing new insights into potential therapeutics of cardiac remodeling-related diseases.

Systematic exploration of the potential material basis and molecular mechanism of the Mongolian medicine Nutmeg-5 in improving cardiac remodeling after myocardial infarction

ETHNOPHARMACOLOGICAL RELEVANCE

Nutmeg-5, which consists of Myristica fragrans Houtt., Aucklandia lappa Decne., Inula helenium L., Fructus Choerospondiatis and Piper longum L., is an ancient and classic formula in traditional Mongolian medicine that is widely used in the treatment of ischemic heart disease. However, its material basis and pharmacological mechanisms remain to be fully elucidated.

AIM OF THE STUDY

The aim of this study was to explore the potential material basis and molecular mechanism of Nutmeg-5 in improving cardiac remodeling after myocardial infarction (MI).

MATERIALS AND METHODS

The constituents of Nutmeg-5 absorbed into the blood were identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS). A mouse MI model was induced in male Kunming mice by permanent ligation of the left anterior descending coronary artery (LDA) ligation. Echocardiography was performed to assess cardiac function. The protective effect of Nutmeg-5 and compound Danshen dripping pills as positive control medicine on post-MI cardiac remodeling was evaluated by tissue histology and determination of the serum protein levels of biomarkers of myocardial injury. RNA sequencing analysis of mouse left ventricle tissue was performed to explore the molecular mechanism of Nutmeg-5 in cardiac remodeling after MI.

RESULTS

A total of 27 constituents absorbed into blood were identified in rat plasma following gavage administration of Nutmeg-5 (0.54 g/kg) for 1 h. We found that ventricular remodeling after MI was significantly improved after Nutmeg-5 treatment in mice, which was demonstrated by decreased mortality, better cardiac function, decreased heart weight to body weight and heart weight to tibia length ratios, and attenuated cardiac fibrosis and myocardial injury. RNA sequencing revealed that the protective effect of Nutmeg-5 on cardiac remodeling after MI was associated with improved heart metabolism. Further study found that Nutmeg-5 treatment could preserve the ultrastructure of mitochondria and upregulate gene expression related to mitochondrial function and structure. HIF-1α (hypoxia inducible factor 1, alpha subunit) expression was significantly upregulated in the hearts of MI mice and significantly suppressed in the hearts of Nutmeg-5-treated mice. In addition, Nutmeg-5 treatment significantly activated the peroxisome proliferator-activated receptor alpha signaling pathway, which was inhibited in the hearts of MI mice.

CONCLUSIONS

Nutmeg-5 attenuates cardiac remodeling after MI by improving heart metabolism and preserving mitochondrial dysfunction by inhibiting HIF-1α expression in the mouse heart after MI.

FABP3 Deficiency Exacerbates Metabolic Derangement in Cardiac Hypertrophy and Heart Failure via PPARα Pathway

Background: Cardiac hypertrophy was accompanied by various cardiovascular diseases (CVDs), and due to the high global incidence and mortality of CVDs, it has become increasingly critical to characterize the pathogenesis of cardiac hypertrophy. We aimed to determine the metabolic roles of fatty acid binding protein 3 (FABP3) on transverse aortic constriction (TAC)-induced cardiac hypertrophy. Methods and Results: Transverse aortic constriction or Ang II treatment markedly upregulated Fabp3 expression. Notably, Fabp3 ablation aggravated TAC-induced cardiac hypertrophy and cardiac dysfunction. Multi-omics analysis revealed that Fabp3-deficient hearts exhibited disrupted metabolic signatures characterized by increased glycolysis, toxic lipid accumulation, and compromised fatty acid oxidation and ATP production under hypertrophic stimuli. Mechanistically, FABP3 mediated metabolic reprogramming by directly interacting with PPARα, which prevented its degradation and synergistically modulated its transcriptional activity on Mlycd and Gck. Finally, treatment with the PPARα agonist, fenofibrate, rescued the pro-hypertrophic effects of Fabp3 deficiency. Conclusions: Collectively, these findings reveal the indispensable roles of the FABP3-PPARα axis on metabolic homeostasis and the development of hypertrophy, which sheds new light on the treatment of hypertrophy.

Anthracycline Associated Disturbances of Cardiovascular Homeostasis

Despite the dynamic progress of modern medicine, oncological and cardiovascular diseases (CVD) remain a severe economic burden worldwide. Therefore, the study of chemotherapeutic cardiotoxicity appears to be comprehensively demanded. Nowadays, pharmacological therapy in oncology has undoubtedly unprecedented development, but at the same time, the rates of cardiovascular complications of chemotherapy still remain unchanged. The well-established and highly effective, but at the same time, cardiotoxic anthracyclines have not lost their relevance. Furthermore, they remain indispensable components of an immense amount of chemotherapy regimens, such as AC, FAC, etc. Moreover, the anthracycline-containing chemotherapy regimens have become a standard of care in several cancer types. In the context of the above mentioned, the study of the pathophysiological mechanisms, biochemical aspects, and dynamics of the morphological remodeling of doxorubicin-induced cardiovascular homeostasis disturbances will enable finding new targets of pharmacological therapy, which either in the short or long perspectives, will have a beneficial effect, improving both the quality of life and prognosis of oncological patients. This article covers a versatile overview of the molecular mechanisms of doxorubicin-induced cardiotoxicity. The pathogenesis of cardiotoxicity assessment could help to explore specific molecular mechanisms that initiate cardiovascular alteration that may favorably affect the future development of targeted drugs that could prevent cardiovascular events in cancer patients.

Pemafibrate Pretreatment Attenuates Apoptosis and Autophagy during Hepatic Ischemia-Reperfusion Injury by Modulating JAK2/STAT3β/PPARα Pathway

Hepatic ischemia-reperfusion injury (HIRI) is a common phenomenon in liver transplantation and liver surgery. This article is aimed at clarifying the role of pemafibrate in HIRI through JAK2/STAT3β/PPARα. In the experiment, we divided Balb/c into seven groups, namely, normal control (NC), Sham, PEM (1.0 mg/kg), IRI, IRI + PEM (0.1 mg/kg), IRI + PEM (0.5 mg/kg), and IRI + PEM (1.0 mg/kg). We used biochemical assay, histopathological evaluation, immunohistochemistry, RT-PCR and qRT-PCR, ELISA analysis, and other methods to determine the level of serum AST, ALT, IL-1β, and TNF-α in the liver at three time points (2 h, 8 h, and 24 h) after reperfusion of apoptosis factor, autophagy factor, and the JAK2/STAT3/PPARα content in tissues. Our experiment results showed that the pemafibrate can effectively reduce the level of hepatic IR injury. In addition, pemafibrate has anti-inflammatory, antiapoptotic, and antiautophagy effects, which are mediated by the JAK2/STAT3β/PPARα pathway.

Dietary alpha- and gamma-tocopherol (1:5 ratio) supplementation attenuates adipose tissue expansion, hepatic steatosis, and expression of inflammatory markers in a high-fat-diet-fed murine model

OBJECTIVES

The aim of this study was to evaluate the effect of the dietary supplementation of an alpha- and gamma-tocopherol mixture (1:5 ratio) in the adipose tissue expansion, hepatic steatosis, and expression of inflammatory markers induced by consumption of a high-fat diet (HFD) in mice.

METHODS

Male C57BL/6 J mice were fed for 12 wk and divided into the following: 1) control diet (CD; 10% fat, 20% protein, 70% carbohydrates); 2) CD + TF (CD plus alpha-tocopherol: 0.7 mg/kg/d, gamma-tocopherol: 3.5 mg/kg/d); 3) HFD (60% fat, 20% protein, 20% carbohydrates); and 4) HFD + TF (HFD plus alpha-tocopherol: 0.7 mg/kg/d, gamma-tocopherol: 3.5 mg/kg/d). General parameters, adipocyte size, liver steatosis, adipose and hepatic tumor necrosis factor-α (TNF-α) and interleukin-1 β (IL-1β) expression, hepatic nuclear factor kappa B (NF-κB), and peroxisome proliferator-activated receptor α (PPAR-α) levels were evaluated.

RESULTS

Tocopherol supplementation in HFD-fed mice showed a significant decrease in the body weight (19%) and adipose tissue weight (52%), adipose tissue/body weight ratio (36%), and serum triacylglycerols (56%); a 42% decrease (P < 0.05) of adipocyte size compared to HFD; attenuation of liver steatosis by decreasing (P < 0.05) lipid vesicles presence (90%) and total lipid content (75%); and downregulation of inflammatory markers (TNF-α and IL-1β), along with an upregulation of hepatic PPAR-α expression and its downstream-regulated genes (ACOX and CAT-1), and an inhibition of hepatic NF-κB activation.

CONCLUSION

The present study suggests that alpha- and gamma-tocopherol (1:5 ratio) supplementation attenuates the adipocyte enlargement, hepatic steatosis, and metabolic inflammation induced by HFD in association with PPAR-α/NF-κB modulation.

Apelin protects against ischemia-reperfusion injury in diabetic myocardium via inhibiting apoptosis and oxidative stress through PI3K and p38-MAPK signaling pathways

Among all diabetes mellitus-associated cardiovascular diseases, morbidity of diabetic myocardium with ischemia reperfusion injury (D-IRI) is increasing year by year. We aimed to discover a therapeutic biomarker and investigate its mechanism in D-IRI. High-fat diet and streptozotocin-induced diabetes rats were operated with IRI or sham. Recombined lentiviral vector encoding Apelin was injected into D-IRI rat via tail vein. Cardiac function, infarct size, cellular death and oxidative stress were major outcome measures. Cardiomyocyte ischemia reperfusion injury was more serious in D-IRI rats than in non-diabetes ischemia reperfusion injury (ND-IRI) rats. The secretion of NTproBNP was increased in D-IRI compared with ND-IRI. Bcl-2 expression was decreased, and Bax and cleaved caspase-3 expression was increased in D-IRI rats compared with ND-IRI rats, which were reversed after treatment with Apelin. Apelin-upregulation improved cardiomyocyte ischemia reperfusion injury and decreased NT-proBNP levels in D-IRI rats. Apelin overexpression enhanced PI3K and eNOS levels while reduced those of p38-MAPK and iNOS in D-IRI rats. Apelin overexpression protected against D-IRI through inhibiting apoptosis and oxidative stress via PI3K and p38MAPK signaling pathways in D-IRI rats. These findings provide critical new insight into understanding of Apelin's cardio-protective effects, which may become a novel therapeutic target for the diabetic IRI patients.

PPARα and PPARβ/δ are negatively correlated with proinflammatory markers in leukocytes of an obese pediatric population

BACKGROUND

Obesity configures a pathophysiological profile that predisposes the development of metabolic and cardiovascular diseases, critically impacting public health. The chronic dysregulation of immuno-metabolic components triggered by pediatric obesity is a common but scarcely understood aspect of the disease. Peroxisome proliferator-activated receptors (PPARs) are a group of transcription factors essential for energy and immune homeostasis of different tissues. Besides, the glucagon-like peptide-1 receptor (GLP-1R) activation influences insulin secretion, but also regulates the cytokine profile possibly mediated through a PPAR isotype. However, the role of PPARs and GLP-1R in leukocytes from obese pediatric patients remains unclear. Therefore, we examined the expression of PPARs isotypes and GLP-1R in leukocytes, and its correlation with metabolic, hormonal, inflammatory, and anthropometric markers in an obese pediatric population.

RESULTS

Obese children and adolescents presented a significant increase in anthropometric and body composition parameters, TG, VLDL, TG/HDL, android fat (%)/gynoid fat (%) (A/G%) index, and HOMA score when compared with the control group. Obese participants exhibited a pro-inflammatory profile with an augment of IL-8 (p = 0,0081), IL-6 (p = 0,0005), TNF-α (p = 0,0004), IFN-γ (p = 0,0110), MCP-1 (p = 0,0452), and adipsin (p = 0,0397), whereas displayed a reduction of adiponectin (p = 0,0452). The expression of PPARα and GLP-1R was lower in the leukocytes from obese participants than in lean subjects. Furthermore, PPARα correlates negatively with TNF-α (p = 0,0383), while GLP-1R did not show correlation with any inflammatory variable. However, both receptors correlate negatively with the abdominal skinfold. Although PPARβ/δ expression was similar between groups, it was negatively associated with IL-8 levels (p = 0,0085).

CONCLUSIONS

PPARα and PPARβ/δ expression are negatively correlated with the proinflammatory markers TNF-α and IL-8, respectively, suggesting participation in the regulation of inflammation which was observed to be altered in pediatric obesity. Furthermore, PPARα and GLP-1R are downregulated in leukocytes from obese participants. The low expression of both receptors is correlated with an increase in abdominal skinfold, suggesting a role in fat distribution that could indirectly affect cytokine secretion from different immune and adipose cells, likely triggering an inflammatory profile as a consequence of obesity. Altogether, these findings may impact the understanding and implementation of PPARα or GLP-1R agonists in the clinic.

PPARα Ameliorates Doxorubicin-Induced Cardiotoxicity by Reducing Mitochondria-Dependent Apoptosis via Regulating MEOX1

Doxorubicin (DOX), a chemotherapeutic drug widely used in the clinical setting, is known to cause serious cardiotoxicity and greatly reduces the survival rate as well as quality of life of patients receiving chemotherapy. Peroxisome proliferation activated receptor α (PPARα) is a type of ligand activated receptor of the nuclear hormone receptor family that regulates multiple gene expression. Several studies have shown that PPARα has anti-apoptotic and cardio-protective effects. However, its role in DOX-induced cardiotoxicity is rarely reported. In this study, we observed decreased expression of PPARα in the heart of tumor-bearing mice already treated with DOX; however, no such phenomenon was observed in tumor tissues. Next, we observed that the PPARα agonist, fenofibrate (FENO), had no effect on tumor progression; however, it enhanced cardiac function in tumor-bearing mice treated with DOX. Subsequently, recombinant adeno-associated virus serotype 9 (rAAV9) was used to manipulate the expression of PPARα in the heart of DOX-induced mice. Our results showed that PPARα gene delivery reduced cardiac dysfunction and mitochondria-dependent apoptosis in DOX-induced mice. Furthermore, we found that PPARα directly regulated the expression of mesenchyme homeobox 1 (MEOX1). Most importantly, the cardioprotective effects of PPARα could be neutralized by knocking down MEOX1. In summary, PPARα plays a vital role in DOX-induced cardiotoxicity and is a promising treatment target.

Applicability of Obesity-Related SNPs and their Effect Size Measures Defined on Populations with European Ancestry for Genetic Risk Estimation among Roma

Investigations on the impact of genetic factors on the development of obesity have been limited regarding the Roma population—the largest and most vulnerable ethnic minority in Europe of Asian origin. Genetic variants identified from genetic association studies are primarily from European populations. With that in mind, we investigated the applicability of data on selected obesity-related single nucleotide polymorphisms (SNPs), obtained from the Hungarian general (HG) population of European origin, on the Hungarian Roma (HR) population. Twenty preselected SNPs in susceptible alleles, known to be significantly associated with obesity-related phenotypes, were used to estimate the effect of these SNPs on body mass index (BMI) and waist circumference (WC) in HG (N = 1783) and HR (N = 1225) populations. Single SNP associations were tested using linear and logistic regression models, adjusted for known covariates. Out of 20 SNPs, four located in FTO (rs1121980, rs1558902, rs9939609, and rs9941349) showed strong association with BMI and WC as continuous variables in both samples. Computations based on Adult Treatment Panel III (ATPIII) and the International Diabetes Federation’s (IDF) European and Asian criteria showed rs9941349 in FTO to be associated only with WC among both populations, and two SNPs (rs2867125, rs6548238) in TMEM18 associated with WC only in HG population. A substantial difference (both in direction and effect size) was observed only in the case of rs1801282 in PPARγ on WC as a continuous outcome. Findings suggest that genetic risk scores based on counting SNPs with relatively high effect sizes, defined based on populations with European ancestry, can sufficiently allow estimation of genetic susceptibility for Roma. Further studies are needed to clarify the role of SNP(s) with protective effect(s).

Molecular Mechanisms of Cardiac Remodeling and Regeneration in Physical Exercise

Regular physical activity with aerobic and muscle-strengthening training protects against the occurrence and progression of cardiovascular disease and can improve cardiac function in heart failure patients. In the past decade significant advances have been made in identifying mechanisms of cardiomyocyte re-programming and renewal including an enhanced exercise-induced proliferational capacity of cardiomyocytes and its progenitor cells. Various intracellular mechanisms mediating these positive effects on cardiac function have been found in animal models of exercise and will be highlighted in this review. 1) activation of extracellular and intracellular signaling pathways including phosphatidylinositol 3 phosphate kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR), EGFR/JNK/SP-1, nitric oxide (NO)-signaling, and extracellular vesicles; 2) gene expression modulation via microRNAs (miR), in particular via miR-17-3p and miR-222; and 3) modulation of cardiac cellular metabolism and mitochondrial adaption. Understanding the cellular mechanisms, which generate an exercise-induced cardioprotective cellular phenotype with physiological hypertrophy and enhanced proliferational capacity may give rise to novel therapeutic targets. These may open up innovative strategies to preserve cardiac function after myocardial injury as well as in aged cardiac tissue.

A Review of Chinese Herbal Medicine for the Treatment of Chronic Heart Failure

Heart failure is one of the major causes of mortality worldwide and it is the end stage of sev-eral cardiovascular diseases. Traditional Chinese medicine has been used in the management of heart failure for a long time. Only until recently, well-designed clinical trials have been put into practice to study the efficacies of Chinese herbs. Extensive studies have also been carried out to explore the under-lying mechanisms of pharmaceutical actions of Chinese herbs. In this study, we will summarize the frequently used Chinese herbs, formulae and patent Chinese drugs in treating patients with heart failure and review published clinical evaluations of Chinese herbs in treating cardiovascular diseases. The mechanisms by which Chinese herbs exert cardio-protective effects will also be reviewed. In the end, we will point out the limitations of current studies and challenges facing modernization of traditional Chi-nese medicine.

PPAR-δ Activation Ameliorates Diabetes-Induced Cognitive Dysfunction by Modulating Integrin-linked Kinase and AMPA Receptor Function

An estimated 9% of the American population experiences type II diabetes mellitus (T2DM) due to diet or genetic predisposition. Recent reports indicate that patients with T2DM are at increased risk for cognitive dysfunctions, as observed in conditions like Alzheimer's disease (AD). In addition, AD is the leading cause of dementia, highlighting the urgency of developing novel therapeutic targets for T2DM-induced cognitive deficits. The peroxisome proliferator activated receptor-δ (PPAR-δ) is highly expressed in the brain and has been shown to play an important role in spatial memory and hippocampal neurogenesis. However, the effect of PPAR-δ agonists on T2DM-induced cognitive impairment has not been explored. In this study, the effects of GW0742 (a selective PPAR-δ agonist) on hippocampal synaptic transmission, plasticity, and spatial memory were investigated in the db/db mouse model of T2DM. Oral administration of GW0742 for 2 weeks significantly improved hippocampal long-term potentiation. In addition, GW0742 effectively prevented deficits in hippocampal dependent spatial memory in db/db mice. PPAR-δ-mediated improvements in synaptic plasticity and behavior were accompanied by a significant recovery in hippocampal α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-mediated synaptic transmission. Our findings suggest that activation of PPAR-δ might ameliorate T2DM-induced impairments in hippocampal synaptic plasticity and memory.

PPARα receptor expression in patients with metabolic syndrome

BACKGROUND

Metabolic syndrome (MS) is considered one of the major worldwide epidemics. It accounts for billions of cardiovascular disease events and deaths. Till now, major basics of MS are not fully clarified. Peroxisome Proliferator-Activated Receptor-α (PPARα) displays a ligand-activated transcription factor. It is involved in the regulation of many metabolic processes including inflammation, lipid, and glucose metabolism. Therefore, this study investigated the leucocytic expression of PPARα in a metabolic patient in comparison to healthy controls.

METHODS

100 subjects with MS were recruited, in addition to 100 subjects without any obvious metabolic disorders as healthy controls. Expression of PPARα and CD 36 were analyzed on different leucocytic populations using optimized flow-cytometric analysis. Correlations of the expression of both indexes with different clinical and laboratory parameters were analyzed.

RESULTS

The eosinophilic expression of PPARα was found to be lower in subjects with MS in comparison to the healthy controls (p value 0.001). Also, PPARα expression, on most of the leucocytic populations, was inversely correlated with waist circumferences among the study populations.

CONCLUSION

Circulated eosinophilic expression of PPARα protein is reduced in MS subjects. This conclusion may explain the endothelial dysfunction and obesity associated with MS, as well as it may help in the management of this worldwide health problem.

Integrated analysis of long noncoding RNA and mRNA profiling ox-LDL-induced endothelial dysfunction after atorvastatin administration

BACKGROUND

Long noncoding RNAs (lncRNAs) play a key role in the development of endothelial dysfunction. However, few lncRNAs associated with endothelial dysfunction after atorvastatin administration have been reported.

METHODS

In the present study, differentially expressed (DE) genes in ox-LDL versus control and ox-LDL + atorvastatin versus control were detected. Bioinformatics analysis and integrated analysis of mRNAs and lncRNAs were conducted to study the mechanisms of endothelial dysfunction after atorvastatin administration and to explore the regulation functions of lncRNAs.

RESULTS

Here, 532 DE mRNAs and 532 DE lncRNAs were identified (among them, 195 mRNAs and 298 lncRNAs were upregulated, 337 mRNAs and 234 lncRNAs were downregulated) after ox-LDL treatment for 24 hours (fold change ≥2.0, P < .05). After ox-LDL treatment following atorvastatin administration, 750 DE mRNAs and 502 DE lncRNAs were identified (among them, 149 mRNAs and 218 lncRNAs were upregulated and 601 mRNAs and 284 lncRNAs were downregulated). After atorvastatin administration, 167 lncRNAs and 262 mRNAs were still DE. Q-PCR validated the results of microarrays.

CONCLUSION

Chronic inflammatory response, nitric oxide biosynthetic process, microtubule cytoskeleton, cell proliferation and cell migration are regulated by lncRNAs, which also participated in the mainly molecular function and biological processes underlying endothelial dysfunction. Atorvastatin partly improved endothelial dysfunction, but the aspects beyond recovery were mainly concentrated in cell cycle, mitosis, and metabolism. Further exploration is required to explicit the mechanism by which lncRNAs participate in endothelial dysfunction.

Phenotype and genotype predictors of BMI variability among European adults

Background/Objective

Obesity is a complex and multifactorial disease resulting from the interactions among genetics, metabolic, behavioral, sociocultural and environmental factors. In this sense, the aim of the present study was to identify phenotype and genotype variables that could be relevant determinants of body mass index (BMI) variability.

Subjects/Methods

In the present study, a total of 1050 subjects (798 females; 76%) were included. Least angle regression (LARS) analysis was used as regression model selection technique, where the dependent variable was BMI and the independent variables were age, sex, energy intake, physical activity level, and 16 polymorphisms previously related to obesity and lipid metabolism.

Results

The LARS analysis obtained the following formula for BMI explanation: (64.7 + 0.10 × age [years] + 0.42 × gender [0, men; 1, women] + −40.6 × physical activity [physical activity level] + 0.004 × energy intake [kcal] + 0.74 × rs9939609 [0 or 1–2 risk alleles] + −0.72 × rs1800206 [0 or 1–2 risk alleles] + −0.86 × rs1801282 [0 or 1–2 risk alleles] + 0.87 × rs429358 [0 or 1–2 risk alleles]. The multivariable regression model accounted for 21% of the phenotypic variance in BMI. The regression model was internally validated by the bootstrap method (r² original data set = 0.208, mean r² bootstrap data sets = 0.210).

Conclusion

In conclusion, age, physical activity, energy intake and polymorphisms in FTO, APOE, PPARG and PPARA genes are significant predictors of the BMI trait.

Autologous fat transplants to deliver glitazone and adiponectin for vasculoprotection

The insulin sensitizing glitazone drugs, rosiglitazone (ROS) and pioglitazone (PGZ) both have anti-proliferative and anti-inflammatory effects and induce adipose tissue (fat) to produce the vaso-protective protein adiponectin. Stenosis due to intimal hyperplasia development often occurs after placement of arteriovenous synthetic grafts used for hemodialysis. This work was performed to characterize the in vitro and in vivo effects of ROS or PGZ incorporation in fat and to determine if fat/PGZ depots could decrease vascular hyperplasia development in a porcine model of hemodialysis arteriovenous graft stenosis. Powdered ROS or PGZ (6-6000μM) was mixed with fat explants and cultured. Drug release from fat was quantified by HPLC/MS/MS, and adiponectin and monocyte chemotactic protein-1 (MCP-1) levels in culture media were measured by ELISA. The effect of conditioned media from the culture of fat with ROS or PGZ on i) platelet-derived growth factor-BB (PDGF-BB)-stimulated proliferation of human venous smooth muscle cells (SMC) was measured by a DNA-binding assay, and ii) lipopolysaccharide (LPS)-induced human monocyte release of tumor necrosis factor-alpha (TNFα) was assessed by ELISA. In a porcine model, pharmacokinetics of PGZ from fat depots transplanted perivascular to jugular vein were assessed by HPLC/MS/MS, and retention of the fat depot was monitored by MRI. A porcine model of synthetic graft placed between carotid artery and ipsilateral jugular vein was used to assess effects of PGZ/fat depots on vascular hyperplasia development. Both ROS and PGZ significantly induced the release of adiponectin and inhibited release of MCP-1 from the fat. TNF production from monocytes stimulated with LPS was inhibited 50-70% in the presence of media conditioned by fat alone or fat and either drug. The proliferation of SMC was inhibited in the presence of media conditioned by fat/ROS cultures. Fat explants placed perivascular to the external jugular vein were retained, as confirmed by MRI at one week after placement. PGZ was detected in the fat depot, in the external jugular vein wall and in adjacent tissue at clinically relevant levels, whereas levels in plasma were below detection. External jugular vein exposed to fat incorporated with PGZ had increased adiponectin expression compared to vein exposed to fat alone. However, the development of hyperplasia within the arteriovenous synthetic grafts was unchanged by treatment with fat/PGZ depots compared to no treatment.

Study of the interactions between Edaglitazone and Ciglitazone with PPARγ and their antiplatelet profile

Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated transcription factor with an important role in lipid metabolism, inflammation and cardiovascular diseases. PPARγ ligands have inhibitory effects on platelet aggregation via the cAMP pathway, which may confer them a protective cardioprotective role. Edaglitazone and Ciglitazone are two chemically-similar thiazolidinedione (TZD) drugs that have been described as potent PPARγ agonists; however, Edaglitazone is over 100 times more potent than Ciglitazone. Here, we report a computational study to describe the ligand binding and the experimental antiplatelet profiles of Edaglitazone and Ciglitazone. Both ligands presented similar orientations within the PPARγ binding site. Their polar heads exhibit complex hydrogen bond networks with the residues at arm I pocket, while their hydrophobic tails are oriented inside arm II or the entrance pocket. The bulkier and longer tail of Edaglitazone exhibited additional hydrophobic interactions, explaining its stronger binding to PPARγ supported by binding affinity calculations. On the other hand, both Edaglitazone and Ciglitazone displayed an antiplatelet activity, but only Edaglitazone retained such effect at low concentrations. Furthermore, we evidenced that Edaglitazone increases intraplatelet cAMP levels and prevents PPARγ secretion, explaining its greater antiplatelet activity. Altogether, the more potent PPARγ agonist Edaglitazone seems to be a potent antiplatelet agent.

Targeting P-selectin glycoprotein ligand-1/P-selectin interactions as a novel therapy for metabolic syndrome

Obesity-induced insulin resistance and metabolic syndrome continue to pose an important public health challenge worldwide as they significantly increase the risk of type 2 diabetes and atherosclerotic cardiovascular disease. Advances in the pathophysiologic understanding of this process has identified that chronic inflammation plays a pivotal role. In this regard, given that both animal models and human studies have demonstrated that the interaction of P-selectin glycoprotein ligand-1 (PSGL-1) with P-selectin is not only critical for normal immune response but also is upregulated in the setting of metabolic syndrome, PSGL-1/P-selectin interactions provide a novel target for preventing and treating resultant disease. Current approaches of interfering with PSGL-1/P-selectin interactions include targeted antibodies, recombinant immunoglobulins that competitively bind P-selectin, and synthetic molecular therapies. Experimental models as well as clinical trials assessing the role of these modalities in a variety of diseases have continued to contribute to the understanding of PSGL-1/P-selectin interactions and have demonstrated the difficulty in creating clinically relevant therapeutics. Most recently, however, computational simulations have further enhanced our understanding of the structural features of PSGL-1 and related glycomimetics, which are responsible for high-affinity selectin interactions. Leveraging these insights for the design of next generation agents has thus led to development of a promising synthetic method for generating PSGL-1 glycosulfopeptide mimetics for the treatment of metabolic syndrome.

Negative regulation of NOD1 mediated angiogenesis by PPARγ-regulated miR-125a

Infection with pathogens activates the endothelial cell and its sustained activation may result in impaired endothelial function. Endothelial dysfunction contributes to the pathologic angiogenesis that is characteristic of infection-induced inflammatory pathway activation. Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) is a protein receptor which recognizes bacterial molecules and stimulates an immune reaction in various cells; however, the underlying molecular mechanisms in the regulation of inflammation-triggered angiogenesis are not fully understood. Here we report that peroxisome proliferator-activated receptor gamma (PPARγ)-mediated miR-125a serves as an important regulator of NOD1 agonist-mediated angiogenesis in endothelial cells by directly targeting NOD1. Treatment of human umbilical vein endothelial cells with natural PPARγ ligand, 15-Deoxy-Delta12,14-prostaglandin J2, led to inhibition of NOD1 expression; contrarily, protein levels of NOD1 were significantly increased by PPARγ knockdown. We report that PPARγ regulation of NOD1 expression is a novel microRNA-mediated regulation in endothelial cells. MiR-125a expression was markedly decreased in human umbilical vein endothelial cells subjected to PPARγ knockdown while 15-Deoxy-Delta12,14-prostaglandin J2 treatment increased the level of miR-125a. In addition, NOD1 is closely regulated by miR-125a, which directly targets the 3' untranslated region of NOD1. Moreover, both overexpression of miR-125a and PPARγ activation led to inhibition of NOD1 agonist-induced tube formation in endothelial cells. Finally, NOD1 agonist increased the formation of cranial and subintestinal vessel plexus in zebrafish, and this effect was abrogated by concurrent PPARγ activation. Overall, these findings identify a PPARγ-miR-125a-NOD1 signaling axis in endothelial cells that is critical in the regulation of inflammation-mediated angiogenesis.

Cardiac Protective Effects of Moringa oleifera Seeds in Spontaneous Hypertensive Rats

BACKGROUND

Hypertension is characterized by a maintained high blood pressure leading to cardiac complications such as left ventricular hypertrophy and fibrosis and an increased risk of heart failure and myocardial infarction. This study investigated the cardiac effects of oral administration of Moringa oleifera (MOI) seed powder in spontaneous hypertensive rats (SHR).

METHODS

SHR received food containing MOI seed powder (750mg/d, 8 weeks) or normal food. In vivo measurement of hemodynamic parameters by telemetry and cardiac structure and function analysis by echocardiography were performed. Histological studies were performed to determine fibrosis and protein expression.

RESULTS

MOI treatment did not modify blood pressure in SHR but reduced nocturnal heart rate and improved cardiac diastolic function (reduction of isovolumetric relaxation time and deceleration time of the E wave, increase of ejection volume and cardiac output compared to nontreated SHR). Left ventricular anterior wall thickness, interseptal thickness on diastole, and relative wall thickness were reduced after MOI treatment. Furthermore, we found a significant reduction of fibrosis in the left ventricle of MOI-treated SHR. This antihypertrophic and antifibrotic effect of MOI was associated with increased expression of peroxisome proliferator-activated receptor (PPAR)-α and δ, reduced cardiac triglyceride level, and enhanced plasmatic prostacyclins.

CONCLUSIONS

Our data show a beneficial effect of MOI on the cardiac structure and function in SHR associated with an upregulation of PPAR-α and δ signaling. This study thus provides scientific rational support for the empirical use of MOI in the traditional Malagasy medicine against cardiac diseases associated with blood pressure overload.

Effect of DanQi Pill on PPARα, lipid disorders and arachidonic acid pathway in rat model of coronary heart disease

Background

Danqi pill (DQP) is one of the most widely prescribed formulas and has been shown to have remarkable protective effect on coronary heart disease (CHD). However, its regulatory effects on lipid metabolism disorders haven’t been comprehensively studied so far. We aimed to explore the effects of DQP on Peroxisome Proliferator activated receptors α (PPARα), lipid uptake-transportation-metabolism pathway and arachidonic acid (AA)-mediated inflammation pathway in rats with CHD.

Methods

80 Sprague-Dawley (SD) Rats were randomly divided into sham group, model group, positive control group and DQP group. Rat model of CHD was induced by ligation of left ventricle anterior descending artery and fed with high fat diet in all but the sham group. Rats in sham group only underwent thoracotomy. After surgery, rats in the positive control and DQP group received daily treatments of pravastatin and DQP respectively. At 28 days after surgery, rats were sacrificed and plasma lipids were evaluated by plasma biochemical detection. Western blot and PCR were applied to evaluate the expressions of PPARα, proteins involved in lipid metabolism and AA pathways.

Results

Twenty eight days after surgery, dyslipidemia developed in CHD model rats, as illustrated by elevated plasma lipid levels. Expressions of apolipoprotein A-I (ApoA-I), cluster of differentiation 36 (CD36) and fatty acid binding protein (FABP) in the heart tissues of model group were down-regulated compared with those in sham group. Expressions of carnitine palmitoyl transferase I (CPT-1A) and lipoproteinlipase (LPL) were also reduced significantly. In addition, levels of phospholipase A2 (PLA2) and cyclooxygenase 2 (COX-2) were up-regulated. Expressions of Nuclear factor-κB (NF- κB) and signal transducer and activator of transcription 3 (STAT3) also increased. Furthermore, Expression of PPARα decreased in the model group. DQP significantly up-regulated expressions of ApoA-I and FABP, as well as the expressions of CPT-1A and CD36. In addition, DQP down-regulated expressions of PLA2, COX-2 and NF-κB in inflammation pathway. Levels of STAT3 and LPL were not affected by DQP treatment. In particular, DQP up-regulated PPARα level significantly.

Conclusions

DQP could effectively regulate lipid uptake-transportation-metabolism process in CHD model rats, and the effect is achieved mainly by activating ApoA-I-CD36-CPT-1A molecules. Interestingly, DQP can up-regulate expression of PPARα significantly. The anti-inflammatory effect of DQP is partly exerted by inhibiting expressions of PLA2-COX2 -NF-κB pathway.

Training-induced anti-atherosclerotic effects are associated with increased vascular PPARgamma expression in apolipoprotein E-deficient mice

AIM

Physical exercise prevents cardiovascular risk and atherosclerosis lesions. However, the molecular aspects are still unknown. Vascular peroxisome proliferator-activated receptors (PPARs) exert anti-atherogenic effects. The aim of this study was to determine whether exercise-induced anti-atherosclerotic effect is associated with change in PPARs vascular expression in apolipoprotein E-deficient (ApoE(-/-) ) mice.

METHODS

Male ApoE(-/-) mice were fed with a high-fat diet and randomized into two groups: one trained group undergoing swimming training for 3 months and one sedentary group. Sedentary and trained C57BL/6J mice were used as control. mRNA of PPAR-α, PPAR-β/δ and PPAR-γ was measured in aorta by quantitative PCR. mRNA of pro- (TNF-α, IL-1β) and anti-inflammatory (IL-10, IL-1Ra) cytokines was also measured.

RESULTS

Atherosclerotic lesion size was significantly reduced in trained ApoE(-/-) mice compared to sedentary ones. In contrast, reduction of atherosclerotic lesion size was not observed in trained ApoE(-/-) mice supplied with BADGE, an antagonist of PPAR-γ. Exercise training significantly increased PPAR-γ expression in aorta. PPAR-γ expression was inversely correlated with the atherosclerotic plaque area. Aortic PPAR-α and PPAR-β/δ mRNA expressions were not changed in response to exercise training. Atherosclerosis increased the aortic mRNA expression of TNF-α, IL-1β, IL-10 and IL-1Ra. Exercise training decreased aortic IL-1β mRNA expression in ApoE(-/-) mice, but did not change expression of TNF-α, IL-10 and IL-1Ra. IL-1β mRNA expression was also significantly lower in atherosclerosis lesions from trained ApoE(-/-) compared with those from sedentary ones.

CONCLUSIONS

Exercise training increases vascular PPAR-γ expression in ApoE(-/-) mice that could potentially underlie training-related beneficial effects on atherosclerosis.

Targeting inflammation in metabolic syndrome

The metabolic syndrome (MetS) is comprised of a cluster of closely related risk factors, including visceral adiposity, insulin resistance, hypertension, high triglyceride, and low high-density lipoprotein cholesterol; all of which increase the risk for the development of type 2 diabetes and cardiovascular disease. A chronic state of inflammation appears to be a central mechanism underlying the pathophysiology of insulin resistance and MetS. In this review, we summarize recent research which has provided insight into the mechanisms by which inflammation underlies the pathophysiology of the individual components of MetS including visceral adiposity, hyperglycemia and insulin resistance, dyslipidemia, and hypertension. On the basis of these mechanisms, we summarize therapeutic modalities to target inflammation in the MetS and its individual components. Current therapeutic modalities can modulate the individual components of MetS and have a direct anti-inflammatory effect. Lifestyle modifications including exercise, weight loss, and diets high in fruits, vegetables, fiber, whole grains, and low-fat dairy and low in saturated fat and glucose are recommended as a first line therapy. The Mediterranean and dietary approaches to stop hypertension diets are especially beneficial and have been shown to prevent development of MetS. Moreover, the Mediterranean diet has been associated with reductions in total and cardiovascular mortality. Omega-3 fatty acids and peroxisome proliferator-activated receptor α agonists lower high levels of triglyceride; their role in targeting inflammation is reviewed. Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone blockers comprise pharmacologic therapies for hypertension but also target other aspects of MetS including inflammation. Statin drugs target many of the underlying inflammatory pathways involved in MetS.

Additive Renoprotection by Pioglitazone and Fenofibrate against Inflammatory, Oxidative and Apoptotic Manifestations of Cisplatin Nephrotoxicity: Modulation by PPARs

Nephrotoxicity is a major side effect for the antineoplastic drug cisplatin. Here, we employed pharmacological, biochemical, and molecular studies to investigate the role of peroxisome proliferator-activated receptors (PPARs) in cisplatin nephrotoxicity. Rats were treated with a single i.p. dose of cisplatin (5 mg/kg) alone or combined with pioglitazone (PPARγ agonist), fenofibrate (PPARα agonist), pioglitazone plus fenofibrate, or thalidomide (Tumor necrosis factor-α inhibitor; TNF-α). Cisplatin nephrotoxicity was evidenced by rises in renal indices of functional (blood urea nitrogen, BUN, and creatinine), inflammatory (TNF-α, interleukin 6, IL-6), oxidative (increased malondialdehyde, MDA, and decreased superoxide dismutase, SOD and nitric oxide metabolites, NOx), apoptotic (caspase 3), and histological (glomerular atrophy, acute tubular necrosis and vacuolation) profiles. Cisplatin effects were partly abolished upon concurrent exposure to pioglitazone, fenofibrate, or thalidomide; more renoprotection was observed in rats treated with pioglitazaone plus fenofibrate. Immunostaining showed that renal expressions of PPARα and PPARγ were reduced by cisplatin and restored to vehicle-treated values after simultaneous treatment with pioglitazone or fenofibrate. Fenofibrate or pioglitazone renoprotection remained unaltered after concurrent blockade of PPARα (GW6471) and PPARγ (GW9662), respectively. To complement the rat studies, we also report that in human embryonic kidney cells (HEK293 cells), increases caused by cisplatin in inflammatory, apoptotic, and oxidative biomarkers were (i) partly improved after exposure to pioglitazone, fenofibrate, or thalidomide, and (ii) completely disappeared in cells treated with a combination of all three drugs. These data establish that the combined use of pioglitazone and fenofibrate additively improved manifestations of cisplatin nephrotoxicity through perhaps GW6471/GW9662-insensitive mechanisms.

Peroxisome proliferator-activated receptor gamma signaling in human sperm physiology

Peroxisome proliferator-activated receptor gamma (PPARγ) is a member of the PPARs, which are transcription factors of the steroid receptor superfamily. PPARγ acts as an important molecule for regulating energy homeostasis, modulates the hypothalamic-pituitary-gonadal (HPG) axis, and is reciprocally regulated by HPG. In the human, PPARγ protein is highly expressed in ejaculated spermatozoa, implying a possible role of PPARγ signaling in regulating sperm energy dissipation. PPARγ protein is also expressed in Sertoli cells and germ cells (spermatocytes). Its activation can be induced during capacitation and the acrosome reaction. This mini-review will focus on how PPARγ signaling may affect fertility and sperm quality and the potential reversibility of these adverse effects.

Peroxisome Proliferator-Activated Receptors and the Heart: Lessons from the Past and Future Directions

Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear family of ligand activated transcriptional factors and comprise three different isoforms, PPAR-α, PPAR-β/δ, and PPAR-γ. The main role of PPARs is to regulate the expression of genes involved in lipid and glucose metabolism. Several studies have demonstrated that PPAR agonists improve dyslipidemia and glucose control in animals, supporting their potential as a promising therapeutic option to treat diabetes and dyslipidemia. However, substantial differences exist in the therapeutic or adverse effects of specific drug candidates, and clinical studies have yielded inconsistent data on their cardioprotective effects. This review summarizes the current knowledge regarding the molecular function of PPARs and the mechanisms of the PPAR regulation by posttranslational modification in the heart. We also describe the results and lessons learned from important clinical trials on PPAR agonists and discuss the potential future directions for this class of drugs.

Activation of peroxisome proliferator-activated receptor γ ameliorates monocrotaline-induced pulmonary arterial hypertension in rats

Activation of peroxisome proliferator-activated receptor γ (PPARγ) suppresses the proliferation of pulmonary artery smooth muscle cells (PASMCs) and vascular remodeling in rats and humans, and therefore improves the development of pulmonary arterial hypertension (PAH). However, molecular mechanisms underlying these effects have not been completely understood. In the present study, the effects of PPARγ activation in monocrotaline (MCT)-induced pulmonary artery remodeling in rats were investigated. Eighteen Sprague-Dawley (SD) rats were randomly assigned into three groups (n=6): Control (Con), PAH and PAH treated with rosiglitazone (MCT + Rosi). The right ventricular systolic pressure (RVSP), the ratio of the right to left ventricle plus septum weight [RV/(LV + S)], the percentage of medial wall thickness (%MT) and wall area (%WA) were used to evaluate the development of PAH. Tissue morphology was measured using hematoxylin and eosin staining. The protein levels of the phosphatase and tensin homologue deleted on chromosome ten (PTEN), Akt (ser473) phosphorylation (p-Akt) and total Akt in intrapulmonary arteries were determined by western blot analysis. MCT treatment significantly increased the RVSP, which was reduced by rosiglitazone treatment. The ratio of RV/(LV + S), %MT and %WA induced by MCT were similarly inhibited, which was associated with the increase of PTEN expression and the inhibition of Akt phosphorylation levels by rosiglitazone. In conclusion, activation of PPARγ ameliorates the proliferation of PASMCs and vascular remodeling by regulating the PTEN/PI3K/Akt pathway, suggesting that the activation of PPARγ has potential benefits for PAH.

Dietary Njavara rice bran oil reduces experimentally induced hypercholesterolaemia by regulating genes involved in lipid metabolism

The present study was carried out to evaluate the anti-atherogenic effect of Njavara rice bran oil (NjRBO) on atherosclerosis by modulating enzymes and genes involved in lipid metabolism in rats fed a high-cholesterol diet (HCD). Adult male rats (Sprague–Dawley strain, weighing 100–120 g) were divided into three groups of nine animals each. Group I served as the control, group II were fed a HCD and group III were fed a HCD and NjRBO (100 mg/kg body weight). The study duration was 60 d. Serum and tissue lipid profile, atherogenic index, enzymes of lipid metabolism, plasma C-reactive protein levels, serum paraoxonase and arylesterase activities, thiobarbituric acid-reactive substances, gene and protein expression of paraoxonase 1 (PON1), PPARα, ATP-binding cassette transporter A1 (ABCA1), apoB and apoA1 in the liver were quantified. Total cholesterol, TAG, phospholipid, NEFA, LDL-cholesterol concentrations in the serum and liver, lipogenic enzyme activities, hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity and atherogenic index were significantly increased in HCD-fed rats, but they decreased after treatment with NjRBO. HDL-cholesterol level and lecithin cholesterol acyl transferase activity were increased in the NjRBO-treated group, but decreased in the HCD-fed group. The expression levels of ABCA1, apoA1, PON1 and PPARα were found to be significantly increased in NjRBO-treated group compared with the HCD-fed group; however, the expression level of apoB was found to be higher in HCD-fed group and lower in the NjRBO-treated group. These data suggest that NjRBO possesses an anti-atherogenic property by modulating lipid metabolism and up-regulating genes involved in reverse cholesterol transport and antioxidative defence mechanism through the induction of the gene expressionPON1.

Structure-based virtual screening and discovery of New PPARδ/γ dual agonist and PPARδ and γ agonists

Peroxisome proliferator-activated receptors (PPARs) are involved in the control of carbohydrate and lipid metabolism and are considered important targets to treat diabetes mellitus and metabolic syndrome. The available PPAR ligands have several side effects leading to health risks justifying the search for new bioactive ligands to activate the PPAR subtypes, in special PPARδ, the less studied PPAR isoform. Here, we used a structure-based virtual screening protocol in order to find out new PPAR ligands. From a lead-like subset of purchasable compounds, we identified 5 compounds with potential PPAR affinity and, from preliminary in vitro assays, 4 of them showed promising biological activity. Therefore, from our in silico and in vitro protocols, new PPAR ligands are potential candidates to treat metabolic diseases.

Breaking the mold: transcription factors in the anucleate platelet and platelet-derived microparticles

Platelets are small anucleate blood cells derived from megakaryocytes. In addition to their pivotal roles in hemostasis, platelets are the smallest, yet most abundant, immune cells and regulate inflammation, immunity, and disease progression. Although platelets lack DNA, and thus no functional transcriptional activities, they are nonetheless rich sources of RNAs, possess an intact spliceosome, and are thus capable of synthesizing proteins. Previously, it was thought that platelet RNAs and translational machinery were remnants from the megakaryocyte. We now know that the initial description of platelets as "cellular fragments" is an antiquated notion, as mounting evidence suggests otherwise. Therefore, it is reasonable to hypothesize that platelet transcription factors are not vestigial remnants from megakaryocytes, but have important, if only partly understood functions. Proteins play multiple cellular roles to minimize energy expenditure for maximum cellular function; thus, the same can be expected for transcription factors. In fact, numerous transcription factors have non-genomic roles, both in platelets and in nucleated cells. Our lab and others have discovered the presence and non-genomic roles of transcription factors in platelets, such as the nuclear factor kappa β (NFκB) family of proteins and peroxisome proliferator-activated receptor gamma (PPARγ). In addition to numerous roles in regulating platelet activation, functional transcription factors can be transferred to vascular and immune cells through platelet microparticles. This method of transcellular delivery of key immune molecules may be a vital mechanism by which platelet transcription factors regulate inflammation and immunity. At the very least, platelets are an ideal model cell to dissect out the non-genomic roles of transcription factors in nucleated cells. There is abundant evidence to suggest that transcription factors in platelets play key roles in regulating inflammatory and hemostatic functions.

Effect of obesity on the association between common variations in the PPAR gene and C-reactive protein level in Chinese Han population

The peroxisome proliferator-activated receptors (PPARs)-α, -β/δ, and -γ are the ligand-activated transcription factors that function as the master regulators of glucose, fatty acid and lipoprotein metabolism, inflammation, and atherosclerosis. Our aim was to test the association between ten single nucleotide polymorphisms of PPARs and CRP level, as well as their interaction with overweight/obesity. A sample population of 643 subjects was recruited from the prevention of MetS and multi-metabolic disorders in Jiangsu Province of China Study. The selected SNPs in PPAR α (rs135539, rs4253778, rs1800206), PPAR β/δ (rs2016520 and rs9794), and PPAR γ (rs10865710, rs1805192, rs709158, rs3856806, and rs4684847) were genotyped. After adjustment for smoking, alcohol consumption, SBP, DBP, TG, and HDL-C, rs1800206, rs709158, rs1805192, and rs4684847 polymorphisms were significantly associated with CRP level in normal weight subjects (P < 0.05). In the overweight/obese subjects, rs1800206 was also significant associated with CRP level (P<0.01). In addition, the rs709158, rs1805192, and rs4684847 polymorphisms were shown interactions with overweight/obesity to influence CRP level (P<0.05). PPARs polymorphisms are independently associated with CRP levels in Chinese Han population. Further, PPARs polymorphisms interact with overweight/obesity to set CRP levels.

Developmental and extracellular matrix-remodeling processes in rosiglitazone-exposed neonatal rat cardiomyocytes

OBJECTIVE

The objective of this study was to investigate the effects of rosiglitazone (Avandia(®)) on gene expression in neonatal rat ventricular myocytes.

MATERIALS & METHODS

Myocytes were exposed to rosiglitazone ex vivo. The two factors examined in the experiment were drug exposure (rosiglitazone and dimethyl sulfoxide vs dimethyl sulfoxide), and length of exposure to drug (½ h, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h, 18 h, 24 h, 36 h and 48 h).

RESULTS

Transcripts that were consistently expressed in response to the drug were identified. Cardiovascular system development, extracellular matrix and immune response are represented prominently among the significantly modified gene ontology terms.

CONCLUSION

Hmgcs2, Angptl4, Cpt1a, Cyp1b1, Ech1 and Nqo1 mRNAs were strongly upregulated in cells exposed to rosiglitazone. Enrichment of transcripts involved in cardiac muscle cell differentiation and the extracellular matrix provides a panel of biomarkers for further analysis in the context of adverse cardiac outcomes in humans. Original submitted 15 November 2013; Revision submitted 14 February 2014.

Cardiac-specific ablation of ARNT leads to lipotoxicity and cardiomyopathy

Patients with type 2 diabetes often present with cardiovascular complications; however, it is not clear how diabetes promotes cardiac dysfunction. In murine models, deletion of the gene encoding aryl hydrocarbon nuclear translocator (ARNT, also known as HIF1β) in the liver or pancreas leads to a diabetic phenotype; however, the role of ARNT in cardiac metabolism is unknown. Here, we determined that cardiac-specific deletion of Arnt in adult mice results in rapid development of cardiomyopathy (CM) that is characterized by accumulation of lipid droplets. Compared with hearts from ARNT-expressing mice, ex vivo analysis of ARNT-deficient hearts revealed a 2-fold increase in fatty acid (FA) oxidation as well as a substantial increase in the expression of PPARα and its target genes. Furthermore, deletion of both Arnt and Ppara preserved cardiac function, improved survival, and completely reversed the FA accumulation phenotype, indicating that PPARα mediates the detrimental effects of Arnt deletion in the heart. Finally, we determined that ARNT directly regulates Ppara expression by binding to its promoter and forming a complex with HIF2α. Together, these findings suggest that ARNT is a critical regulator of myocardial FA metabolism and that its deletion leads to CM and an increase in triglyceride accumulation through PPARα.

Role of the ubiquitin-proteasome system in cardiac dysfunction of adipose triglyceride lipase-deficient mice

Systemic deletion of the gene encoding for adipose triglyceride lipase (ATGL) in mice leads to severe cardiac dysfunction due to massive accumulation of neutral lipids in cardiomyocytes. Recently, impaired peroxisome proliferator-activated receptor α (PPARα) signaling has been described to substantially contribute to the observed cardiac phenotype. Disturbances of the ubiquitin-proteasome system (UPS) have been implicated in numerous cardiac diseases including cardiomyopathy, ischemic heart disease, and heart failure. The objective of the present study was to investigate the potential role of UPS in cardiac ATGL deficiency. Our results demonstrate prominent accumulation of ubiquitinated proteins in hearts of ATGL-deficient mice, an effect that was abolished upon cardiomyocyte-directed overexpression of ATGL. In parallel, cardiac protein expression of the ubiquitin-activating enzyme E1a, which catalyzes the first step of the ubiquitination cascade, was significantly upregulated in ATGL-deficient hearts. Dysfunction of the UPS was accompanied by activation of NF-κB signaling. Moreover, the endoplasmic reticulum (ER)-resident chaperon protein disulfide isomerase was significantly upregulated in ATGL-deficient hearts. Chronic treatment of ATGL-deficient mice with the PPARα agonist Wy14,643 improved proteasomal function, prevented NF-κB activation and decreased oxidative stress. In summary, our data point to a hitherto unrecognized link between proteasomal function, PPARα signaling and cardiovascular disease.

Effect of peroxisome proliferator-activated receptor gamma agonist on heart of rabbits with acute myocardial ischemia/reperfusion injury

OBJECTIVE

To explore protective effect of rosiglitazone on myocardial ischemia reperfusion injury.

METHODS

A total of 48 male SD rats were randomly divided into control group (A), I/R group(B), high dose of rosiglitazone (C), low dose of rosiglitazone (D). Plasm concentration of creatine kinase (CK), CK-MB, hsCRP, Superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), nitric oxide (NO) and endothelin (ET) were measured 1 h later after I/R. 24 h after I/R hearts were harvested to observe pathological and ultrastructural changes. Immunohistochemistry and western blotting was used to test CD40 expression in myocardial tissue. Area of myocardial infarction were tested, arrhythmia rate during I/R was recorded.

RESULTS

Plasm concentration of creatine kinase (CK), CK-MB, hsCRP, NO, MDA and ET were decreased in group C, D compared with group B. Plasm concentration of T-SOD and GSH-Px was increased significantly in group C, D compared with group B. Compared with group B, pathological and ultrastructural changes in group C, D were slightly. Myocardial infarction area and arrhythmia rate were lower in group C, D compare with group B.

CONCLUSIONS

Rosiglitazone can protect myocardium from I/R injury by enhancing T-SOD and GSH-Px concentration, inhibit inflammatory reaction, improve endothelial function, reduce oxidative stress and calcium overload.

Peroxisome proliferator-activated receptors for hypertension

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily, which is composed of four members encoded by distinct genes (α, β, γ, and δ). The genes undergo transactivation or transrepression under specific mechanisms that lead to the induction or repression of target gene expression. As is the case with other nuclear receptors, all four PPAR isoforms contain five or six structural regions in four functional domains; namely, A/B, C, D, and E/F. PPARs have many functions, particularly functions involving control of vascular tone, inflammation, and energy homeostasis, and are, therefore, important targets for hypertension, obesity, obesity-induced inflammation, and metabolic syndrome in general. Hence, PPARs also represent drug targets, and PPARα and PPARγ agonists are used clinically in the treatment of dyslipidemia and type 2 diabetes mellitus, respectively. Because of their pleiotropic effects, they have been identified as active in a number of diseases and are targets for the development of a broad range of therapies for a variety of diseases. It is likely that the range of PPARγ agonist therapeutic actions will result in novel approaches to lifestyle and other diseases. The combination of PPARs with reagents or with other cardiovascular drugs, such as diuretics and angiotensin II receptor blockers, should be studied. This article provides a review of PPAR isoform characteristics, a discussion of progress in our understanding of the biological actions of PPARs, and a summary of PPAR agonist development for patient management. We also include a summary of the experimental and clinical evidence obtained from animal studies and clinical trials conducted to evaluate the usefulness and effectiveness of PPAR agonists in the treatment of lifestyle-related diseases.

Cellular responses to excess fatty acids: focus on ubiquitin regulatory X domain-containing protein 8

PURPOSE OF REVIEW

Although fatty acids are crucial for cell survival, their overaccumulation triggers lipotoxicity that leads to metabolic syndrome. Thus, cells maintain their homeostasis by multiple feedback regulatory systems. This review focuses on how cells regulate the level of fatty acids by these systems.

RECENT FINDINGS

Ubiquitin regulatory X domain-containing protein 8 has been identified as a specific sensor for unsaturated fatty acids that regulates lipogenic activity.

SUMMARY

Together with the previously identified peroxisome proliferator-activated receptors and liver X receptor, these proteins sense the presence of unsaturated fatty acids and initiate reactions preventing their overaccumulation. Understanding the mechanism of the signal transduction pathways mediated by these proteins may offer new strategies to treat metabolic syndrome.

New Insights into the PPAR γ Agonists for the Treatment of Diabetic Nephropathy

Diabetic nephropathy (DN) is a severe complication of diabetes and serves as the leading cause of chronic renal failure. In the past decades, angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin II receptor blockers (ARBs) based first-line therapy can slow but cannot stop the progression of DN, which urgently requests the innovation of therapeutic strategies. Thiazolidinediones (TZDs), the synthetic exogenous ligands of nuclear receptor peroxisome proliferator-activated receptor- γ (PPAR γ ), had been thought to be a promising candidate for strengthening the therapy of DN. However, the severe adverse effects including fluid retention, cardiovascular complications, and bone loss greatly limited their use in clinic. Recently, numerous novel PPAR γ agonists involving the endogenous PPAR γ ligands and selective PPAR γ modulators (SPPARMs) are emerging as the promising candidates of the next generation of antidiabetic drugs instead of TZDs. Due to the higher selectivity of these novel PPAR γ agonists on the regulation of the antidiabetes-associated genes than that of the side effect-associated genes, they present fewer adverse effects than TZDs. The present review was undertaken to address the advancements and the therapeutic potential of these newly developed PPAR γ agonists in dealing with diabetic kidney disease. At the same time, the new insights into the therapeutic strategies of DN based on the PPAR γ agonists were fully addressed.