PPARα agonists inhibit inflammatory activation of macrophages through upregulation of β-defensin 1

Inhibition of tumor migration and invasion by fenofibrate via suppressing epithelial-mesenchymal transition in breast cancers

The recurrence and metastasis in breast cancer within 3 years after the chemotherapies or surgery leads to poor prognosis with approximately 1-year overall survival. Large-scale scanning research studies have shown that taking lipid-lowering drugs may assist to reduce the risk of death from many cancers, since cholesterol in lipid rafts are essential for maintain integral membrane structure and functional signaling regulation. In this study, we examined five lipid-lowering drugs: swertiamarin, gemfibrozil, clofibrate, bezafibrate, and fenofibrate in triple-negative breast cancer, which is the most migration-prone subtype. Using human and murine triple-negative breast cancer cell lines (Hs 578 t and 4 T1), we found that fenofibrate displays the highest potential in inhibiting the colony formation, wound healing, and transwell migration. We further discovered that fenofibrate reduces the activity of pro-metastatic enzymes, matrix metalloproteinases (MMP)-9 and MMP-2. In addition, epithelial markers including E-cadherin and Zonula occludens-1 are increased, whereas mesenchymal markers including Snail, Twist and α-smooth muscle actin are attenuated. Furthermore, we found that fenofibrate downregulates ubiquitin-dependent GDF-15 degradation, which leads to enhanced GDF-15 expression that inhibits cell migration. Besides, nuclear translocation of FOXO1 is also upregulated by fenofibrate, which may responsible for GDF-15 expression. In summary, fenofibrate with anti-cancer ability hinders TNBC from migration and invasion, and may be beneficial to repurposing use of fenofibrate.

Gastrin attenuates sepsis-induced myocardial dysfunction by down-regulation of TLR4 expression in macrophages

Myocardial dysfunction is the most serious complication of sepsis. Sepsis-induced myocardial dysfunction (SMD) is often associated with gastrointestinal dysfunction, but its pathophysiological significance remains unclear. The present study found that patients with SMD had higher plasma gastrin concentrations than those without SMD. In mice, knockdown of the gastrin receptor, cholecystokinin B receptor (Cckbr), aggravated lipopolysaccharide (LPS)-induced cardiac dysfunction and increased inflammation in the heart, whereas the intravenous administration of gastrin ameliorated SMD and cardiac injury. Macrophage infiltration plays a significant role in SMD because depletion of macrophages by the intravenous injection of clodronate liposomes, 48 h prior to LPS administration, alleviated LPS-induced cardiac injury in Cckbr-deficient mice. The intravenous injection of bone marrow macrophages (BMMs) overexpressing Cckbr reduced LPS-induced myocardial dysfunction. Furthermore, gastrin treatment inhibited toll-like receptor 4 (TLR4) expression through the peroxisome proliferator-activated receptor α (PPAR-α) signaling pathway in BMMs. Thus, our findings provide insights into the mechanism of the protective role of gastrin/CCKBR in SMD, which could be used to develop new treatment modalities for SMD.

Fenofibrate Attenuates Asthma Features in an Ovalbumin-induced Mouse Model Via Suppressing NF-κB Binding Activity

BACKGROUND/AIM

Asthma is a chronic inflammatory disease of the airways with a high prevalence. Asthma has a complex pathophysiology and about 5-10% of patients are not fully responsive to the currently available treatments. The aim of this study is to investigate the involvement of NF-κB in the effects of fenofibrate on a mouse model of allergic asthma.

MATERIALS AND METHODS

A total of 49 BALB/c mice were randomly distributed into 7 groups (n=7). Allergic asthma model was created by administering i.p. injections of ovalbumin on days 0, 14 and 21, followed by provocation with inhaled ovalbumin on days 28, 29 and 30. Fenofibrate was orally given in 3 different doses; 1, 10 and 30mg/kg through days 21 to 30 of the experiment. On day 31, pulmonary function test using whole body plethysmography was performed. The mice were sacrificed 24hours later. Blood samples were obtained, and serum of each sample was separated for IgE determination. Bronchoalveolar lavage fluid (BALF) and lung tissues were collected to measure IL-5 and IL-13 levels. Nuclear extracts of lung tissues were employed to assess nuclear factor kappa B (NF-κB) p65 binding activity.

RESULTS

Enhanced Pause (Penh) values were significantly increased in ovalbumin-sensitized and challenged mice (p<0.01). Administration of fenofibrate (10 and 30mg/kg) resulted in improved pulmonary function as shown by significantly lower Penh values (p<0.01). Interleukin (IL) -5 and IL-13 levels in BALF and lung tissues and immunoglobulin E (IgE) levels in serum were significantly elevated in the allergic mice. IL-5 levels in the lung tissues of mice treated with 1mg/kg fenofibrate (FEN1) group were significantly reduced (p<0.01). BALF and lung tissue IL-5 and IL-13 levels in mice treated with 10 and 30mg/kg fenofibrate, FEN10 and FEN30, respectively, were significantly diminished when compared to the ovalbumin-treated (OVA) group, whereas treatment with 1mg/kg fenofibrate resulted in insignificant changes. IgE levels in the serum of FEN30 group mice have shown a prominent reduction (p<0.01). NF-κB p65 binding activity was higher in mice sensitized and challenged with ovalbumin (p<0.01). NF-κB p65 binding activity was significantly reduced in allergic mice treated with 30mg/kg (p<0.01) fenofibrate.

CONCLUSIONS

In this study, we showed that administration of 10 and 30mg/kg fenofibrate effectively attenuated airway hyperresponsiveness and inflammation in a mouse model of allergic asthma, possibly through inhibition of NF-κB binding activity.

Efficacy and safety of metabolic interventions for the treatment of severe COVID-19: in vitro, observational, and non-randomized open-label interventional study

Background

Viral infection is associated with a significant rewire of the host metabolic pathways, presenting attractive metabolic targets for intervention.

Methods

We chart the metabolic response of lung epithelial cells to SARS-CoV-2 infection in primary cultures and COVID-19 patient samples and perform in vitro metabolism-focused drug screen on primary lung epithelial cells infected with different strains of the virus. We perform observational analysis of Israeli patients hospitalized due to COVID-19 and comparative epidemiological analysis from cohorts in Italy and the Veteran's Health Administration in the United States. In addition, we perform a prospective non-randomized interventional open-label study in which 15 patients hospitalized with severe COVID-19 were given 145 mg/day of nanocrystallized fenofibrate added to the standard of care.

Results

SARS-CoV-2 infection produced transcriptional changes associated with increased glycolysis and lipid accumulation. Metabolism-focused drug screen showed that fenofibrate reversed lipid accumulation and blocked SARS-CoV-2 replication through a PPARα-dependent mechanism in both alpha and delta variants. Analysis of 3233 Israeli patients hospitalized due to COVID-19 supported in vitro findings. Patients taking fibrates showed significantly lower markers of immunoinflammation and faster recovery. Additional corroboration was received by comparative epidemiological analysis from cohorts in Europe and the United States. A subsequent prospective non-randomized interventional open-label study was carried out on 15 patients hospitalized with severe COVID-19. The patients were treated with 145 mg/day of nanocrystallized fenofibrate in addition to standard-of-care. Patients receiving fenofibrate demonstrated a rapid reduction in inflammation and a significantly faster recovery compared to patients admitted during the same period.

Conclusions

Taken together, our data suggest that pharmacological modulation of PPARα should be strongly considered as a potential therapeutic approach for SARS-CoV-2 infection and emphasizes the need to complete the study of fenofibrate in large randomized controlled clinical trials.

Funding

Funding was provided by European Research Council Consolidator Grants OCLD (project no. 681870) and generous gifts from the Nikoh Foundation and the Sam and Rina Frankel Foundation (YN). The interventional study was supported by Abbott (project FENOC0003).

Clinical trial number

NCT04661930.

The PPARα Regulation of the Gut Physiology in Regard to Interaction with Microbiota, Intestinal Immunity, Metabolism, and Permeability

Peroxisome proliferator-activated receptor alpha (PPARα) is expressed throughout the mammalian gut: in epithelial cells, in the villi of enterocytes and in Paneth cells of intestinal crypts, as well as in some immune cells (e.g., lamina propria macrophages, dendritic cells) of the mucosa. This review examines the reciprocal interaction between PPARα activation and intestinal microbiota. We refer to the published data confirming that microbiota products can influence PPARα signaling and, on the other hand, PPARα activation is able to affect microbiota profile, viability, and diversity. PPARα impact on the broad spectrum of events connected to metabolism, signaling (e.g., NO production), immunological tolerance to dietary antigens, immunity and permeability of the gut are also discussed. We believe that the phenomena described here play a prominent role in gut homeostasis. Therefore, in conclusion we propose future directions for research, including the application of synthetic activators and natural endogenous ligands of PPARα (i.e., endocannabinoids) as therapeutics for intestinal pathologies and systemic diseases assumed to be related to gut dysbiosis.

Lipid and Lipoprotein Dysregulation in Sepsis: Clinical and Mechanistic Insights into Chronic Critical Illness

In addition to their well-characterized roles in metabolism, lipids and lipoproteins have pleiotropic effects on the innate immune system. These undergo clinically relevant alterations during sepsis and acute inflammatory responses. High-density lipoprotein (HDL) plays an important role in regulating the immune response by clearing bacterial toxins, supporting corticosteroid release, decreasing platelet aggregation, inhibiting endothelial cell apoptosis, reducing the monocyte inflammatory response, and inhibiting expression of endothelial cell adhesion molecules. It undergoes quantitative as well as qualitative changes which can be measured using the HDL inflammatory index (HII). Pro-inflammatory, or dysfunctional HDL (dysHDL) lacks the ability to perform these functions, and we have also found it to independently predict adverse outcomes and organ failure in sepsis. Another important class of lipids known as specialized pro-resolving mediators (SPMs) positively affect the escalation and resolution of inflammation in a temporal fashion. These undergo phenotypic changes in sepsis and differ significantly between survivors and non-survivors. Certain subsets of sepsis survivors go on to have perilous post-hospitalization courses where this inflammation continues in a low grade fashion. This is associated with immunosuppression in a syndrome of persistent inflammation, immunosuppression, and catabolism syndrome (PICS). The continuous release of tissue damage-related patterns and viral reactivation secondary to immunosuppression feed this chronic cycle of inflammation. Animal data indicate that dysregulation of endogenous lipids and SPMs play important roles in this process. Lipids and their associated pathways have been the target of many clinical trials in recent years which have not shown mortality benefit. These results are limited by patient heterogeneity and poor animal models. Considerations of sepsis phenotypes and novel biomarkers in future trials are important factors to be considered in future research. Further characterization of lipid dysregulation and chronic inflammation during sepsis will aid mortality risk stratification, detection of sepsis, and inform individualized pharmacologic therapies.

Ophiopogonin D Increases SERCA2a Interaction with Phospholamban by Promoting CYP2J3 Upregulation

Ophiopogonin D (OPD), a compound from the Chinese herb Radix Ophiopogonis, reportedly induces increased levels of cytochrome P450 2J3 (CYP2J3)/epoxyeicosatrienoic acids (EETs) and Ca²⁺ in rat cardiomyocytes. Little is known regarding the specific mechanism between CYP2J3 and Ca²⁺ homeostasis. Here, we investigated whether CYP2J3 is involved in the protective action of OPD on the myocardium by activating the Ca²⁺ homeostasis-related protein complex (SERCA2a and PLB) in H9c2 rat cardiomyoblast cells. The interaction between SERCA2a and PLB was measured using fluorescence resonance energy transfer. OPD attenuated heart failure and catalyzed the active transport of Ca²⁺ into the sarcoplasmic reticulum by inducing the phosphorylation of PLB and promoting the SERCA2a activity. These beneficial effects of OPD on heart failure were abolished after knockdown of CYP2J3 in a model of heart failure. Together, our results identify CYP2J3 as a critical intracellular target for OPD and unravel a mechanism of CYP2J3-dependent regulation of intracellular Ca²⁺.

The Basal Pharmacology of Palmitoylethanolamide

Palmitoylethanolamide (PEA, N-hexadecanoylethanolamide) is an endogenous compound belonging to the family of N-acylethanolamines. PEA has anti-inflammatory and analgesic properties and is very well tolerated in humans. In the present article, the basal pharmacology of PEA is reviewed. In terms of its pharmacokinetic properties, most work has been undertaken upon designing formulations for its absorption and upon characterising the enzymes involved in its metabolism, but little is known about its bioavailability, tissue distribution, and excretion pathways. PEA exerts most of its biological effects in the body secondary to the activation of peroxisome proliferator-activated receptor-α (PPAR-α), but PPAR-α-independent pathways involving other receptors (Transient Receptor Potential Vanilloid 1 (TRPV1), GPR55) have also been identified. Given the potential clinical utility of PEA, not least for the treatment of pain where there is a clear need for new well-tolerated drugs, we conclude that the gaps in our knowledge, in particular those relating to the pharmacokinetic properties of the compound, need to be filled.

PPAR-α Agonist Fenofibrate Suppressed the Formation of Ocular Surface Squamous Metaplasia Induced by Topical Benzalkonium Chloride

Purpose

To investigate the effects and mechanisms of the peroxisome proliferator-activated receptor alpha (PPAR-α) agonist fenofibrate on the formation of ocular surface squamous metaplasia induced by topical benzalkonium chloride (BAC) in a mouse model.

Methods

Ocular surface squamous metaplasia was induced in 16 days by topical BAC application in mice. During the period of induction, mice were divided into four groups: no additional treatment (BAC+UT), topical vehicle (BAC+Vehicle), topical fenofibrate (BAC+Feno), or topical fenofibrate plus intraperitoneal injection of MK886 (BAC+Feno+MK886). The parameters of tear film were evaluated on day 16, and eye specimens were collected. Histologic investigation; PAS assays; immunostaining for cytokeratin 10 (K10), Ki67, and F4/80; and PCR assays for TNF-α and IL-6 were performed. Cell Counting Kit 8 (CCK-8) assays were performed to evaluate the inhibitory effects of fenofibrate on RAW264.7 cells.

Results

Fenofibrate suppressed the formation of BAC-induced instable tear film. In the BAC+Feno group, the expression of K10 and Ki67 was lower than in the other three groups. The number of goblet cells was reduced in eyes of the BAC+UT and BAC+Vehicle groups but was maintained in eyes of the BAC+Feno group. The number of F4/80-positive cells and the levels of TNF-α and IL-6 mRNA were significantly reduced in the cornea of the BAC+Feno group. These effects of fenofibrate could be attenuated by MK886. The cell viability of RAW264.7 cells could be significantly inhibited by fenofibrate in a dose-dependent pattern.

Conclusions

Topical application of fenofibrate suppressed the formation of ocular surface squamous metaplasia, which might be mediated through the PPAR-α signaling pathway.

Pharmacological targets of metabolism in disease: Opportunities from macrophages

From advances in the knowledge of the immune system, it is emerging that the specialized functions displayed by macrophages during the course of an immune response are supported by specific and dynamically-connected metabolic programs. The study of immunometabolism is demonstrating that metabolic adaptations play a critical role in modulating inflammation and, conversely, inflammation deeply influences the acquisition of specific metabolic settings.This strict connection has been proven to be crucial for the execution of defined immune functional programs and it is now under investigation with respect to several human disorders, such as diabetes, sepsis, cancer, and autoimmunity. The abnormal remodelling of the metabolic pathways in macrophages is now emerging as both marker of disease and potential target of therapeutic intervention. By focusing on key pathological conditions, namely obesity and diabetes, rheumatoid arthritis, atherosclerosis and cancer, we will review the metabolic targets suitable for therapeutic intervention in macrophages. In addition, we will discuss the major obstacles and challenges related to the development of therapeutic strategies for a pharmacological targeting of macrophage's metabolism.

Regulation and Mechanism of miR-518d through the PPARα-Mediated NF-κB Pathway in the Development of Gestational Diabetes Mellitus

OBJECTIVES

To observe the role of miR-518d in pregnant women with gestational diabetes mellitus (GDM) and its adjusting effects on PPARα and to explore the regulatory mechanisms of the NF-κB pathway in the development and progression of GDM.

METHODS

Placenta tissues and peripheral plasma were obtained from pregnant women with normal pregnancy and GDM, respectively, followed by the detections of miR-518d contents by RT-PCR and the expression levels of inflammatory factors using ELISA. Human placenta trophoblast cells (HTR8/SVneo) were cultured under the conditions of physiological glucose (PG group) and high glucose level (HG group). Cells in the HG group were transfected with miR-518d control, mimics, and inhibitors and were separately administered with a PPARα-specific antagonist (GW6471) and PPARα siRNA, and cells were divided into the following groups: HG+miR-518d control group (HGNC group), HG+miR-518d mimic group (HGM group), HG+miR-518d inhibitor group (HGI group), HGI+PPARα antagonist group, and HGI+PPARα siRNA group. The relative expression levels of miR-518d, PPARα, and its downstream genes and NF-κB signalling pathway-related genes were detected by RT-PCR and Western blotting. The contents of inflammatory factors were examined by Western blotting. A dual-luciferase report assay was performed to validate the correlations between miR-518d and PPARα. In this study, mouse GDM models were established to further prove the previous hypothesis with an in vivo experiment. A total of 40 C57BL/6J mice were randomly divided into the following groups: normal diet group (Control_Ms), GDM group (GDM_Ms group), GDM+miR-518d antagomir group, and GDM+miR-518d antagomir+PPARα antagonist group. The mouse model of GDM was established by feeding with combined high-sugar and high-saturated fat diet and injecting streptozotocin (STZ) after 15-day feeding. Female and male mice were cocaged in the number ratio of 2 : 1, and the evidence of vaginal suppository detected in female mice was marked as D0 of pregnancy. The contents of total cholesterol (CH), triglyceride (TG), fast glucose, and insulin (INS) were examined using ELISA, followed by the evaluation of insulin resistance (IR). The related expression levels were also detected with the above methods shown in the previous cell culture.

RESULTS

miR-518d has a high expression level in placentas with GDM. As the target gene of miR-518d, PPARα was downregulated with the increased levels of miR-518d. When GDM occurs, inflammatory responses were elevated, stimulating the nuclear transport process of NF-κB. Activated NF-κB triggered the phosphorylation of IKKβ and IκBα.

CONCLUSIONS

High expression of miR-518d was observed in the development of GDM. In this study, we validated that miR-518d negatively regulates the expression of PPARα and triggers the nuclear transport process of NF-κB and phosphorylation of pathway-associated proteins leading to an inflammatory response and the development of GDM.

Self-regulation of the inflammatory response by peroxisome proliferator-activated receptors

The peroxisome proliferator-activated receptor (PPAR) family includes three transcription factors: PPARα, PPARβ/δ, and PPARγ. PPAR are nuclear receptors activated by oxidised and nitrated fatty acid derivatives as well as by cyclopentenone prostaglandins (PGA₂ and 15d-PGJ₂) during the inflammatory response. This results in the modulation of the pro-inflammatory response, preventing it from being excessively activated. Other activators of these receptors are nonsteroidal anti-inflammatory drug (NSAID) and fatty acids, especially polyunsaturated fatty acid (PUFA) (arachidonic acid, ALA, EPA, and DHA). The main function of PPAR during the inflammatory reaction is to promote the inactivation of NF-κB. Possible mechanisms of inactivation include direct binding and thus inactivation of p65 NF-κB or ubiquitination leading to proteolytic degradation of p65 NF-κB. PPAR also exert indirect effects on NF-κB. They promote the expression of antioxidant enzymes, such as catalase, superoxide dismutase, or heme oxygenase-1, resulting in a reduction in the concentration of reactive oxygen species (ROS), i.e., secondary transmitters in inflammatory reactions. PPAR also cause an increase in the expression of IκBα, SIRT1, and PTEN, which interferes with the activation and function of NF-κB in inflammatory reactions.

Osthole inhibits oleic acid/lipopolysaccharide-induced lipid accumulation and inflammatory response through activating PPARα signaling pathway in cultured hepatocytes

Osthole, a coumarin derivative, can increase hepatic peroxisome proliferator-activated receptor α (PPARα) expression and reduce hepatic steatosis and inflammatory response in rats with non-alcoholic steatohepatitis (NASH). In this study, a cell model of NASH was induced with oleic acid (OA)/lipopolysaccharide (LPS) and treated for 36 h with different osthole concentrations. Results showed that intracellular lipid and inflammatory cytokine levels gradually decreased after osthole treatment. These effects, however, were abolished or attenuated after PPARα gene silencing. Accordingly, PPARα gene silencing reversed the osthole-mediated expressions of proteins involved in lipid synthesis and fatty acid oxidation. PPARα gene silencing also abrogated the inhibitory effect of osthole on nuclear factor kappa B p65 protein expression. These findings demonstrate that osthole activates PPARα signaling pathway to inhibit lipid accumulation and inflammatory response in OA/LPS-stimulated hepatocytes.

PPARα suppresses Th17 cell differentiation through IL-6/STAT3/RORγt pathway in experimental autoimmune myocarditis

Family members of peroxisome proliferator-activated receptors (PPARs), such as PPARγ, have been shown to be effective in regulating T helper 17 (Th17) cell differentiation. However, whether PPARα, another important family member of PPARs, contributes to Th17 cell differentiation remains controversial. In the present study, we show that PPARα may be a negative regulator of Th17 cell differentiation. In CD4⁺ T cells from PPARα knockout mice, PPARα deficiency enhances IL-17 and IL-6 levels and promotes Th17 cell differentiation. In contrast, in CD4⁺ T cells from wild type mice, PPARα activation suppresses Th17 cell differentiation. Furthermore, IL-6 neutralizing antibody dose-dependently reduces the activity of STAT3 and down-regulates the protein expression of RORγt in CD4⁺ T cells from PPARα knockout mice but has no effect on that of wild type mice. On the other hand, in isolated CD4⁺ T cells from experimental autoimmune myocarditis (EAM) rats, PPARα agonist Fenofibrate decreased the expression of IL-17 and RORγt, increased the expression of Foxp3, while PPARα antagonist MK886 reversed these effects. Importantly, in vivo activation of PPARα ameliorates EAM by suppressing Th17 cell differentiation through reducing the expression of RORγt and phosphorylated STAT3 that are upregulated in EAM hearts. These results imply that PPARα suppresses Th17 cell differentiation through IL-6/STAT3/RORγt signaling pathway and suggest that PPARα may become a molecular target for treating autoimmune myocarditis.

Metabolic Alterations Associated with Atorvastatin/Fenofibric Acid Combination in Patients with Atherogenic Dyslipidaemia: A Randomized Trial for Comparison with Escalated-Dose Atorvastatin

In the current study, the metabolic effects of atorvastatin dose escalation versus atorvastatin/fenofibric acid combination were compared using metabolomics analyses. Men and women with combined hyperlipidaemia were initially prescribed atorvastatin (10 mg, ≥4 weeks). Patients who reached low-density lipoprotein-cholesterol targets, but had triglyceride and high-density lipoprotein-cholesterol levels ≥150 mg/dL and <50 mg/dL, respectively, were randomized to receive atorvastatin 20 mg or atorvastatin 10 mg/fenofibric acid 135 mg for 12 weeks. Metabolite profiling of serum was performed and changes in metabolites after drug treatment in the two groups were compared. Analysis was performed using patients' samples obtained before and after treatment. Of 89 screened patients, 37 who met the inclusion criteria were randomized, and 34 completed the study. Unlike that in the dose-escalation group, distinct clustering of both lipid and aqueous metabolites was observed in the combination group after treatment. Most lipid metabolites of acylglycerols and many of ceramides decreased, while many of sphingomyelins increased in the combination group. Atorvastatin dose escalation modestly decreased lysophosphatidylcholines; however, the effect of combination therapy was variable. Most aqueous metabolites decreased, while L-carnitine remarkably increased in the combination group. In conclusion, the atorvastatin/fenofibric acid combination induced distinct metabolite clustering. Our results provide comprehensive information regarding metabolic changes beyond conventional lipid profiles for this combination therapy.

Hepatocyte-specific PPARA expression exclusively promotes agonist-induced cell proliferation without influence from nonparenchymal cells

Peroxisome proliferator-activated receptor-α (PPARA) is a nuclear transcription factor and key mediator of systemic lipid metabolism. Prolonged activation in rodents causes hepatocyte proliferation and hepatocellular carcinoma. Little is known about the contribution of nonparenchymal cells (NPCs) to PPARA-mediated cell proliferation. NPC contribution to PPARA agonist-induced hepatomegaly was assessed in hepatocyte (Ppara^△Hep)- and macrophage (Ppara^△Mac)-specific Ppara null mice. Mice were treated with the agonist Wy-14643 for 14 days, and response of conditional null mice was compared with conventional knockout mice (Ppara^-/- ). Wy-14643 treatment caused weight loss and severe hepatomegaly in wild-type and Ppara^△Mac mice, and histological analysis revealed characteristic hepatocyte swelling; Ppara^△Hep and Ppara^-/- mice were protected from these effects. Ppara^△Mac serum chemistries, as well as aspartate aminotransferase and alanine aminotransferase levels, matched wild-type mice. Agonist-treated Ppara^△Hep mice had elevated serum cholesterol, phospholipids, and triglycerides when compared with Ppara^-/- mice, indicating a possible role for extrahepatic PPARA in regulating circulating lipid levels. BrdU labeling confirmed increased cell proliferation only in wild-type and Ppara^△Mac mice. Macrophage PPARA disruption did not impact agonist-induced upregulation of lipid metabolism, cell proliferation, or DNA damage and repair-related gene expression, whereas gene expression was repressed in Ppara^△Hep mice. Interestingly, downregulation of inflammatory cytokines IL-15 and IL-18 was dependent on macrophage PPARA. Cell type-specific regulation of target genes was confirmed in primary hepatocytes and Kupffer cells. These studies conclusively show that cell proliferation is mediated exclusively by PPARA activation in hepatocytes and that Kupffer cell PPARA has an important role in mediating the anti-inflammatory effects of PPARA agonists.

Bezafibrate Attenuates Pressure Overload-Induced Cardiac Hypertrophy and Fibrosis

Background. Peroxisome proliferator-activated receptor-α (PPAR-α) is closely associated with the development of cardiac hypertrophy. Previous studies have indicated that bezafibrate (BZA), a PPAR-α agonist, could attenuate insulin resistance and obesity. This study was designed to determine whether BZA could protect against pressure overload-induced cardiac hypertrophy. Methods. Mice were orally given BZA (100 mg/kg) for 7 weeks beginning 1 week after aortic banding (AB) surgery. Cardiac hypertrophy was assessed based on echocardiographic, histological, and molecular aspects. Moreover, neonatal rat ventricular cardiomyocytes (NRVMs) were used to investigate the effects of BZA on the cardiomyocyte hypertrophic response in vitro. Results. Our study demonstrated that BZA could alleviate cardiac hypertrophy and fibrosis in mice subjected to AB surgery. BZA treatment also reduced the phosphorylation of protein kinase B (AKT)/glycogen synthase kinase-3β (GSK3β) and mitogen-activated protein kinases (MAPKs). BZA suppressed phenylephrine- (PE-) induced hypertrophy of cardiomyocyte in vitro. The protective effects of BZA were abolished by the treatment of the PPAR-α antagonist in vitro. Conclusions. BZA could attenuate pressure overload-induced cardiac hypertrophy and fibrosis.

Protective effects of fenofibrate and resveratrol in an aggressive model of rheumatoid arthritis in rats

Context Fibrates were reported to have anti-inflammatory effects while the naturally occurring polyphenol resveratrol was traditionally known as a potent antioxidant agent. Objective The effects of fenofibrate and resveratrol were investigated on complete Freund's adjuvant (CFA)-induced rheumatoid arthritis (RA) in adult female albino rats. Materials and methods Rats were divided into a normal control group, an arthritis control group receiving CFA, two reference treatment groups receiving dexamesathone (1.5 mg/kg/day) and methotrexate (1 mg/kg/day), and two treatment groups receiving fenofibrate (100 mg/kg/day) and resveratrol (10 mg/kg/day) for seven consecutive days. Assessment of RA was performed by measuring serum rheumatoid factor (RF), matrix metalloprotinease-3 (MMP-3) and cartilage oligomeric matrix protein (COMP) as specific rheumatoid biomarkers, immunoglobulin G (IgG) and antinuclear antibody (ANA) as immunological biomarkers, tumour necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10) as immunomodulatory cytokines, myeloperoxidase (MPO) and C-reactive protein (CRP) as inflammatory biomarkers and malondialdehyde (MDA) and glutathione (GSH) as oxidative stress biomarkers, supported by a histopathological study on joints and spleens. Results Serum RF, MMP-3, COMP, IgG, ANA, TNF-α, MPO, CRP and MDA were decreased to about 36, 56, 66, 65, 9, 35, 24, 44 and 31% by fenofibrate, and to about 37, 59, 44, 70, 5, 30, 23, 33 and 28% by resveratrol treatments, respectively. Alternatively, serum IL-10 and GSH were significantly increased to about 215 and 251% by fenofibrate and to about 225 and 273% by resveratrol treatments, respectively. Discussion and conclusion Fenofibrate and resveratrol protect against RA, possibly through their immunomodulatory, anti-inflammatory and antioxidant potential.