PPARγ Pathway Research Articles

PPAR gamma agonist leriglitazone improves frataxin-loss impairments in cellular and animal models of Friedreich Ataxia

Friedreich ataxia (FRDA), the most common autosomal recessive ataxia, is characterized by degeneration of the large sensory neurons and spinocerebellar tracts, cardiomyopathy, and increased incidence in diabetes. The underlying pathophysiological mechanism of FRDA, driven by a significantly decreased expression of frataxin (FXN), involves increased oxidative stress, reduced activity of enzymes containing iron‑sulfur clusters (ISC), defective energy production, calcium dyshomeostasis, and impaired mitochondrial biogenesis, leading to mitochondrial dysfunction. The peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcriptional factor playing a key role in mitochondrial function and biogenesis, fatty acid storage, energy metabolism, and antioxidant defence. It has been previously shown that the PPARγ/PPARγ coactivator 1 alpha (PGC-1α) pathway is dysregulated when there is frataxin deficiency, thus contributing to FRDA pathogenesis and supporting the PPARγ pathway as a potential therapeutic target. Here we assess whether MIN-102 (INN: leriglitazone), a novel brain penetrant and orally bioavailable PPARγ agonist with an improved profile for central nervous system (CNS) diseases, rescues phenotypic features in cellular and animal models of FRDA. In frataxin-deficient dorsal root ganglia (DRG) neurons, leriglitazone increased frataxin protein levels, reduced neurite degeneration and α-fodrin cleavage mediated by calpain and caspase 3, and increased survival. Leriglitazone also restored mitochondrial membrane potential and partially reversed decreased levels of mitochondrial Na+/Ca2+ exchanger (NCLX), resulting in an improvement of mitochondrial functions and calcium homeostasis. In frataxin-deficient primary neonatal cardiomyocytes, leriglitazone prevented lipid droplet accumulation without increases in frataxin levels. Furthermore, leriglitazone improved motor function deficit in YG8sR mice, a FRDA mouse model. In agreement with the role of PPARγ in mitochondrial biogenesis, leriglitazone significantly increased markers of mitochondrial biogenesis in FRDA patient cells. Overall, these results suggest that targeting the PPARγ pathway by leriglitazone may provide an efficacious therapy for FRDA increasing the mitochondrial function and biogenesis that could increase frataxin levels in compromised frataxin-deficient DRG neurons. Alternately, leriglitazone improved the energy metabolism by increasing the fatty acid β-oxidation in frataxin-deficient cardiomyocytes without elevation of frataxin levels. This could be linked to a lack of significant mitochondrial biogenesis and cardiac hypertrophy. The results reinforced the different tissue requirement in FRDA and the pleiotropic effects of leriglitazone that could be a promising therapy for FRDA.

Role of peroxisome proliferators-activated receptor-gamma in advanced glycation end product-mediated functional loss of voltage-gated potassium channel in rat coronary arteries

Abstract Background Voltage-gated K+ (Kv) channels in coronary artery smooth muscle cells (CSMCs), especially the major specific Kv1 subfamily, contribute to coronary artery vasodilation. Advanced glycation end products (AGEs) have been strongly implicated in diabetes-related cardiovascular complications. Our previous study showed AGEs can impair Kv channel-mediated coronary vasodilation by reducing Kv channel activity. However, its underlying mechanism remains unclear. Purpose Here, we used isolated rat small coronary arteries (RSCAs) and primary CSMCs to investigate the effect of AGEs on Kv channel-mediated coronary vasodilation and the possible involvement of peroxisome proliferators-activated receptor (PPAR)-γ pathway. Methods RSCAs and primary CSMCs were isolated, cultured and treated with bovine serum albumin (BSA), AGE-BSA, alagrebrium (ALA, AGE cross-linking breaker), pioglitazone (PIO) and/or GW9662, and then divided into the following groups: DMEM, BSA, AGE, AGE+ALA, AGE+PIO, and AGE+PIO+GW9662. Kv channel-mediated coronary vasodilation was analyzed using wire myograph. Histology and immunohistochemistry of RSCAs were performed. Western blot was used to detect the protein expression of RAGE, the major Kv1 channel subunits expressed in CSMCs (Kv1.2/1.5), PPAR-γ, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-2 (NOX-2). Results AGEs markedly reduced forskolin-induced Kv channel-mediated vasodilation of RSCAs by interacting with the receptor for AGEs (RAGE), and ALA or PIO significantly reversed this effect. In both RSCAs and primary CSMCs, AGEs decreased Kv1.2 and Kv1.5 channel protein expression, inhibited PPAR-γ expression, increased RAGE and NOX-2 expression. Treatment with ALA or PIO partially reversed the effects of AGEs on Kv1.2/Kv1.5 expression, accompanied by elevation of PPAR-γ level and diminished oxidative stress. Conclusion AGE/RAGE axis-induced inhibition of PPAR-γ pathway and enhancement of oxidative stress may contribute to AGEs-mediated Kv channel dysfunction and coronary vasodilation in RSCAs. Our results may provide new insights into developing therapeutic strategies to manage diabetic vasculature. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): National Natural Science Foundation of China; Natural Science Foundation of Beijing (7172059)

Circulating Levels of CILP2 Are Elevated in Coronary Heart Disease and Associated with Atherosclerosis.

Methods and Results Circulating CILP2 levels (measured by ELISA) were compared to various insulin resistance- and atherosclerosis-related parameters in normal subjects and newly diagnosed CHD patients. THP-1 cells were cultured and treated with indicated stimulators. Western blots and RT-PCR were performed to examine protein and mRNA expressions. The results showed that there were significantly higher circulating CILP2 levels in CHD patients relative to healthy controls. Circulating CILP2 correlated positively with waist-hip ratio (WHR), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), HbA1c, homeostasis model assessment of insulin resistance (HOMA-IR), and Gensini scores. In an in vitro study, we found that CILP2 increased oxidatively modified LDL-stimulated lipid accumulation in THP-1 macrophages via the upregulation of CD36 expression. Inhibition of PPARγ signaling eliminated the CILP2 regulation of CD36 expression in THP-1 macrophages. CILP2 positively regulated CD36 transcription through PPARγ-mediated action on two peroxisome-proliferator-responsive elements (PPREs) binding sites of CD36 promoter, PPRE-G, and PPRE-J. Conclusions Our findings have uncovered a novel role for CILP2 in lipid uptake and foam cell formation. This role is mediated by CD36 through the activation of PPARγ pathway.

Effect of Quercetin 3-O-β-D-Galactopyranoside on the Adipogenic and Osteoblastogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stromal Cells.

Natural products, especially phenols, are promising therapeutic agents with beneficial effects against aging-related complications such as osteoporosis. This study aimed to investigate the effect of quercetin 3-O-β-D-galactopyranoside (Q3G), a glycoside of a common bioactive phytochemical quercetin, on osteogenic and adipogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs). hBM-MSCs were induced to differentiate into osteoblasts and adipocytes in the presence or absence of Q3G and the differentiation markers were analyzed to observe the effect. Q3G treatment stimulated the osteoblastogenesis markers: cell proliferation, alkaline phosphatase (ALP) activity and extracellular mineralization. In addition, it upregulated the expression of RUNX2 and osteocalcin protein as osteoblastogenesis regulating transcription factors. Moreover, Q3G treatment increased the activation of osteoblastogenesis-related Wnt and bone morphogenetic protein (BMP) signaling displayed as elevated levels of phosphorylated β-catenin and Smad1/5 in nuclear fractions of osteo-induced hBM-MSCs. The presence of quercetin in adipo-induced hBM-MSC culture inhibited the adipogenic differentiation depicted as suppressed lipid accumulation and expression of adipogenesis markers such as PPARγ, SREBP1c and C/EBPα. In conclusion, Q3G supplementation stimulated osteoblast differentiation and inhibited adipocyte differentiation in hBM-MSCs via Wnt/BMP and PPARγ pathways, respectively. This study provided useful information of the therapeutic potential of Q3G against osteoporosis mediated via regulation of MSC differentiation.

Non-Viable Lactobacillus johnsonii JNU3402 Protects against Diet-Induced Obesity.

In this study, the role of non-viable Lactobacillus johnsonii JNU3402 (NV-LJ3402) in diet-induced obesity was investigated in mice fed a high-fat diet (HFD). To determine whether NV-LJ3402 exhibits a protective effect against diet-induced obesity, 7-week-old male C57BL/6J mice were fed a normal diet, an HFD, or an HFD with NV-LJ3402 for 14 weeks. NV-LJ3402 administration was associated with a significant reduction in body weight gain and in liver, epididymal, and inguinal white adipose tissue (WAT) and brown adipose tissue weight in HFD-fed mice. Concomitantly, NV-LJ3402 administration to HFD-fed mice also decreased the triglyceride levels in the plasma and metabolic tissues and slightly improved insulin resistance. Furthermore, NV-LJ3402 enhanced gene programming for energy dissipation in the WATs of HFD-fed mice as well as in 3T3-L1 adipocytes with increased peroxisome proliferator-activated receptor-γ (PPARγ) transcriptional activity, suggesting that the PPARγ pathway plays a key role in mediating the anti-obesity effect of NV-LJ3402 in HFD-fed mice. Furthermore, NV-LJ3402 administration in HFD-fed mice enhanced mitochondrial levels and function in WATs and also increased the body temperature upon cold exposure. Together, these results suggest that NV-LJ3402 could be safely used to develop dairy products that ameliorate diet-induced obesity and hyperlipidemia.

Sesame oil mitigates memory impairment, oxidative stress, and neurodegeneration in a rat model of Alzheimer's disease. A pivotal role of NF-κB/p38MAPK/BDNF/PPAR-γ pathways

Ethnopharmacological relevanceSesame (Sesamum indicum, L., Family: Pedaliaceae) is a notable folk medicine in Middle East, Asia and Africa. Many traditional and pharmacological studies have documented the unique nature of sesame oil (SO). SO has been reported to have many pharmacological effects related to the anti-inflammatory and antioxidant capacity of its components. Neuroinflammation and oxidative stress have been the predominant pathogenic events in Alzheimer's disease (AD) which is one of the most common neurodegenerative diseases. Aim of studywe aimed to explore the neuroprotective effect and the probable mechanisms of SO against aluminium chloride (AlCl3)-induced AD symptoms. Materials and methodsRats were treated daily with AlCl3 (100 mg/kg/i.p.) either alone or with SO (two different doses) for six weeks. Behavioral (Open-field and Morris water maze tests), histopathological, and biochemical examinations were used to evaluate the neuroprotective effect and the underlying mechanisms of SO against AlCl3-induced AD symptoms. ResultsOur results indicated that SO significantly improved learning and memory impairments induced by AlCl3. Indeed, SO treatment significantly restored the elevated level of acetylcholinesterase (AChE) and amyloid beta (Aβ) overexpression. Moreover, AlCl3 treatment afforded histopathological changes, increase the expression of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) in addition to mitigation of oxidative stress status in the brain. SO abolished all these abnormalities. Meanwhile, AlCl3 induced activation of p38 mitogen-activated protein kinase (p38MAPK) and decreased brain-derived neurotrophic factor (BDNF) which were inhibited by SO. Furthermore, SO administration modulated the expression of the peroxisome proliferator-activated receptor gamma (PPAR-γ) and nuclear factor kappa B (NF-κB). ConclusionsIn conclusion, the neuroprotective effect of SO involved the modulation of different mechanisms targeting oxidative stress, neuroinflammation, and cognitive functions. SO may modulate different molecular targets involved in AD pathogenesis by alterations of NF-κB/p38MAPK/BDNF/PPAR-γ signalling and this may be attributed to the synergistic effect of their active components.

Pioglitazone modulates doxorubicin resistance in a in vivo model of drug resistant osteosarcoma xenograft.

Osteosarcoma has been reported with treatment failure in up to 40% of cases. Our laboratory had identified genes involved in the PPARγ pathway to be associated with doxorubicin (DOX) resistance. We hence used PPARγ agonist pioglitazone (PIO) to modulate DOX resistance. DOX-resistant cell line (143B-DOX) was developed by gradient exposure to DOX. The cytotoxicity to PIO and in combination with DOX was assayed in vitro, followed by HPLC to estimate the metabolites of PIO in the presence of microsomes (HLMs). Gene expression studies revealed the mechanism behind the cytotoxicity of PIO. Further, the effects were evaluated in mice bearing 143B-DOX tumors treated either with PIO (20 mg/kg/p.o or 40 mg/kg/p.o Q1D) alone or in combination with DOX (0.5 mg/kg/i.p Q2W). 143B-DOX was 50-fold resistant over parental cells. While PIO did not show any activity on its own, the addition of HLMs to the cells in culture showed over 80% cell kill within 24 h, possibly due to the metabolites of PIO as determined by HPLC. In combination with DOX, PIO had shown synergistic activity. Additionally, cytotoxicity assay in the presence of HLMs revealed that PIO on its own showed promising activity compared to its metabolites-hydroxy pioglitazone and keto pioglitazone. In vivo studies demonstrated that treatment with 40 mg/kg/p.o PIO alone showed significant activity, followed by a combination with DOX. Gene expression studies revealed that PIO could modulate drug resistance by downregulating MDR1 and IL8. Our study suggests that PIO can modulate DOX resistance in osteosarcoma cells.

NRF2 and PPAR-γ Pathways in Oligodendrocyte Progenitors: Focus on ROS Protection, Mitochondrial Biogenesis and Promotion of Cell Differentiation.

An adequate protection from oxidative and inflammatory reactions, together with the promotion of oligodendrocyte progenitor (OP) differentiation, is needed to recover from myelin damage in demyelinating diseases. Mitochondria are targets of inflammatory and oxidative insults and are essential in oligodendrocyte differentiation. It is known that nuclear factor-erythroid 2-related factor/antioxidant responsive element (NRF2/ARE) and peroxisome proliferator-activated receptor gamma/PPAR-γ response element (PPAR-γ/PPRE) pathways control inflammation and overcome mitochondrial impairment. In this study, we analyzed the effects of activators of these pathways on mitochondrial features, protection from inflammatory/mitochondrial insults and cell differentiation in OP cultures, to depict the specificities and similarities of their actions. We used dimethyl-fumarate (DMF) and pioglitazone (pio) as agents activating NRF2 and PPAR-γ, respectively, and two synthetic hybrids acting differently on the NRF2/ARE pathway. Only DMF and compound 1 caused early effects on the mitochondria. Both DMF and pio induced mitochondrial biogenesis but different antioxidant repertoires. Moreover, pio induced OP differentiation more efficiently than DMF. Finally, DMF, pio and compound 1 protected from tumor necrosis factor-alpha (TNF-α) insult, with pio showing faster kinetics of action and compound 1 a higher activity than DMF. In conclusion, NRF2 and PPAR-γ by inducing partially overlapping pathways accomplish complementary functions aimed at the preservation of mitochondrial function, the defense against oxidative stress and the promotion of OP differentiation.

The PPAR-γ inhibitor T0070907 normalizes impaired electro-mechanical properties of human-induced pluripotent stem cell-derived cardiomyocytes in DSC2 arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) primarily involves right ventricle impairment and lethal arrhythmias. Hereditary forms of ACM are mostly caused by mutations in genes coding for desmosomal proteins. Histopathological hallmark includes fibrofatty replacement of myocardial tissue, which may involve transdifferentiation of cardiomyocytes into adipocyte cells through the PPAR-γ pathway. Comprehensive investigation of cardiomyocytes electro-mechanical properties during this process has never been undertaken. We aimed to assess the implication of the PPAR-γ pathway inhibition using T0070907 inhibitor. We used cardiomyocytes (hiPSC-CM) differentiated from an ACM patient-derived pluripotent stem cells (hiPSC) harbouring a mutation (R132 C) in the DSC2 gene. The control and DSC2 hiPSC were reprogrammed and differentiated into hiPSC-CM to examine gene expression, electro-mechanical properties (patch-clamp and video analysis) and calcium handling (fluorescence imaging) profiles. The DSC2 hiPSC-CM were cultured for 40 days in presence or absence of 1 μM T0070907. The RT-qPCR of both DSC2 patient's heart samples and hiPSC-CM showed an increase of PPAR-γ expression when compared to control cells. When compared to control hiPSC-CM, the DSC2 hiPSC-CM exhibited a shorter action potential duration, due to an increase of K+ current density. Culture of DSC2 hiPSC-CM with the PPAR-γ inhibitor normalized both the action potential duration and K+ current density. Differences were also found in both the calcium transient and mechanical properties between control, DSC2 and DSC2 with PPAR-γ hiPSC-CM. PPAR-γ pathway inhibition by T0070907 normalized the disrupted electro-mechanical properties in DSC2 hiPSC-CM. This result opens interesting perspectives for further studies of the adipogenesis pathway to prevent appearance of fibro-fatty adipose tissue in the ACM patient's heart.

Inhibition of miR-27b Regulates Lipid Metabolism in Skeletal Muscle of Obese Rats During Hypoxic Exercise by Increasing PPARγ Expression.

Hypoxic exercise may represent a novel therapeutic strategy to reduce and prevent obesity through the regulation of lipid metabolism. During hypoxic exercise, the targeting of peroxisome proliferator-activated receptor gamma (PPARγ) by miR-27b has been proposed to be one of the mechanisms involved in the modulation of lipid metabolism. We have previously shown that miR-27b can repress PPARγ and lipid metabolism-associated factors, thereby affecting lipid metabolism during hypoxic exercise in a rat model of obesity. In the current study, we aimed to confirm the role of miR-27b in the regulation of lipid metabolism. First, miR-27b expression was either upregulated or downregulated through the injection of adeno-associated virus (AAV) 9 containing a miR-27b expression cassette or miR-27b-3p inhibitor, respectively, into the right gastrocnemius muscle of obese rats. The rats were then subjected to a 4-week program of hypoxic exercise, and a series of parameters related to lipid metabolism were systematically evaluated, including body composition, blood lipid levels, miR-27b RNA levels, and mRNA and protein levels of PPARγ and those of its downstream lipid metabolism-associated factors. No significant differences were found in body composition between rats expressing different levels of miR-27b. However, regarding blood lipids, miR-27b overexpression led to increased concentrations of triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and free fatty acids (FFAs), while inhibition of miR-27b decreased the total cholesterol (TC) level and increased that of high-density lipoprotein cholesterol (HDL-C). At the mRNA level, miR-27b overexpression downregulated the expression of Pparγ, but upregulated that of lipid metabolism-associated factors such as heart-type fatty acid-binding protein (H-FABP), fatty acid transport protein 1 (FATP1), adipose triglyceride lipase (ATGL), and lipoprotein lipase (LPL), whereas miR-27b inhibition elicited the opposite effect; however, inhibition of miR-27b led to elevated cholesterol 7 alpha-hydroxylase (CYP7A1) and fatty acid translocase 36 (CD36) levels. Similarly, at the protein level, miR-27b overexpression promoted a decrease in the concentration of PPARγ, whereas miR-27b inhibition led to an increase in PPARγ levels, as well as those of CYP7A1, CD36, ATGL, and LPL. Overall, our results indicated that hypoxic exercise regulates lipid metabolism via the miR-27b/PPARγ pathway and modulates ATGL and LPL expression through inducing their post-transcriptional modifications.

Yarrow oil ameliorates ulcerative colitis in mice model via regulating the NF-κB and PPAR-γ pathways

Background/AimsUlcerative colitis (UC) is a chronic inflammatory disorder with indefinite etiology; however, environmental, genetic, immune factors and microbial agents could be implicated in its pathogenesis. UC treatment is lifelong, therefore; the potential side effects and cost of the therapy are significant. Yarrow is a promising medicinal plant with the ability to treat many disorders, owing to its bioactive compounds especially the essential oil. The main aim of this research was to investigate the therapeutic effect of the yarrow oil on colitis including the involved mechanism of action.MethodsIn 21-female C57BL/6 mice were divided into 3 groups; control group, colitis model group, and oil-treated group. Groups 2 and 3 received 5% dextran sulfate sodium (DSS) in drinking water for 9 days, and concomitantly, only group 3 was given 100 mg/kg yarrow oil. Mice were examined for their body weight, stool consistency and bleeding, and the disease activity indexes were calculated.ResultsOral administration of yarrow oil markedly repressed the severity of UC via the reduction of the inflammatory signs and restoring colon length. The oil was able to down-regulate nuclear factor kappa light chain enhancer of activated B cells (NF-κB), up-regulate peroxisome proliferator-activated receptor gamma (PPAR-γ), and enhance transforming growth factor-β expression. The oil normalized the tumor necrosis factor-α expression, restored the normal serum level of interleukin-10 (IL-10) and reduced the serum level of IL-6.ConclusionsYarrow oil mitigated UC symptoms and regulated the inflammatory cytokines secretion via regulation of NF-κB and PPAR-γ pathways in the mice model, however, this recommendation requires further investigations using clinical studies to confirm the use of the oil on humans.

Abstract 4966: MyD88 in myofibroblasts enhances colitis-associated tumorigenesis via promoting macrophage M2 polarization in mice

Abstract Background & Aims: The signal adapter MyD88, an essential component of TLR signaling, plays an important role in gut-microbiome interactions. However, its contribution to colitis-associated cancer (CAC) is still controversial. We investigated whether MyD88 signaling in myofibroblasts contributes to an environment that promotes CAC development. Methods: C57BL/6J mice (control) and mice with myofibroblasts-specific deletion of MyD88 (Fib-MyD88 KO) were performed azoxymethane (AOM)/dextran sodium sulfate (DSS) model or DSS model. Colon tissue was collected and analyzed for inflammation, cell proliferation and macrophage polarization. Primary normal fibroblasts (NFs) were isolated and measured for mechanisms that induced macrophage polarization. Results: Myofibroblasts MyD88-deficient mice were resistant to AOM/DSS-induced tumorigenesis, as evidence by the decrease in the number and sizes of tumors. MyD88 deficiency in myofibroblasts did not affect the inflammatory response but attenuated intestinal epithelial cell (IEC) proliferation after acute DSS-induced colitis. Furthermore, MyD88 signaling in myofibroblasts increased the secretion of osteopontin (OPN), which promoted macrophage M2 polarization through binding to αvβ3 and CD44, leading to activation of the STAT3 and PPARγ pathways. Conclusions: MyD88 signaling in myofibroblasts crucially contributes to colorectal cancer development and provides a promising therapeutic target for the prevention of colitis-associated carcinogenesis. Citation Format: Jinhua Zhang, Tian Tian, Qi Yuan. MyD88 in myofibroblasts enhances colitis-associated tumorigenesis via promoting macrophage M2 polarization in mice [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4966.

Cyanidin-3-O-glucoside restores insulin signaling and reduces inflammation in hypertrophic adipocytes

Obesity is a metabolic disorder characterized by excess adipose tissue, macrophages infiltration, and inflammation which in turn lead to insulin-resistance. Epidemiological evidences reported that anthocyanins possess not only high antioxidant and antiinflammatory activities, but also improve metabolic complications associated with obesity. The aim of this work was to evaluate the in vitro beneficial effects of cyanidin-3-O-glucoside (C3G) in counteracting inflammation and insulin-resistance in 3T3-L1 hypertrophic adipocytes exposed to palmitic acid (PA). In the present study murine 3T3-L1 adipocytes were pretreated with C3G for 24 h and then exposed to palmitic acid (PA) for 24 h. Real‐time PCR, western blotting analysis and Oil Red O staining were applied for investigating the mechanism involved in adipocytes dysfunction. C3G pretreatment reduced lipid accumulation, PPARγ pathway and NF-κB pathway induced by PA in murine adipocytes. In addition, our data demonstrated that PA reduced insulin signaling via IRS-1 Ser307phosphorylation while C3G dose-dependently improved insulin sensitivity restoring IRS-1/PI3K/Akt pathway. Furthermore, C3G improved adiponectin mRNA levels altered by PA in 3T3-L1 murine and SGBS human adipocytes. Herein reported data demonstrate that C3G ameliorated adipose tissue dysfunction, thus suggesting new potential roles for this compound of nutritional interest in the prevention of pathological conditions linked to obesity.

Co-exposure to multi-walled carbon nanotube and lead ions aggravates hepatotoxicity of nonalcoholic fatty liver via inhibiting AMPK/PPARγ pathway.

Multi-walled carbon nanotubes (MWCNTs) have been widely used in sewage disposal, water purification, and disinfection. Co-exposure to MWCNTs and heavy metal ions is common during water disposal. However, the hepatotoxicity of co-exposure to MWCNTs and lead ions for nonalcoholic fatty liver disease (NAFLD) subjects has not been investigated. NAFLD mice were fed intragastrically with MWCNTs and lead acetate (PbAc). Combined administration of MWCNTs and PbAc significantly damaged the liver function, and aggravated the nonalcoholic steatohepatitis phenotype as well as the hepatic fibrosis and steatosis in NAFLD mice. Furthermore, MWCNTs and PbAc significantly induced apoptosis in primary hepatocytes isolated from NAFLD mice. Combined administration of MWCNTs and PbAc also resulted in hepatic lipid peroxidation by inducing antioxidant defense system dysfunction, and significantly enhanced the expression levels of inflammatory cytokines in NAFLD mice livers. Meanwhile, combined administration of MWCNTs and PbAc may exert its hepatotoxicity in the NAFLD via inhibiting the adenosine 5‘-monophosphate activated protein kinase (AMPK)/peroxisome proliferator-activated receptors γ (PPARγ) pathway. Taken together, we conclude that co-exposure to MWCNTs and PbAc can remarkably aggravate the hepatotoxicity in NAFLD mice via inhibiting the AMPK/PPARγ pathway. This study may provide a biosafety evaluation for the application of nanomaterials in wastewater treatment.

Asperosaponin VI inhibits LPS-induced inflammatory response by activating PPAR-γ pathway in primary microglia.

Microglia cells are the main mediators of neuroinflammation. Activation of microglia often aggravates the pathological process of various neurological diseases. Natural chemicals have unique advantages in inhibiting microglia-mediated neuroinflammation and improving neuronal function. Here, we examined the effects of asperosaponin VI (ASA VI) on LPS-activated primary microglia. Microglia were isolated from mice and pretreated with different doses of ASA VI, following lipopolysaccharide (LPS) administration. Activation and inflammatory response of microglia cells were evaluated by real-time fluorescence quantitative polymerase chain reaction (q-PCR), immunohistochemistry and enzyme-linked immunosorbent assay (ELISA). Signaling pathways were detected by western blotting. We found that the ASA VI inhibited the morphological expansion of microglia cells, decreased the expression and release of proinflammatory cytokines, and promoted the expression of antiinflammatory cytokines in a dose-dependent manner. ASA VI also activated PPAR-γ signaling pathway in LPS-treated microglia. The anti-inflammatory effects of ASA VI in microglia were blocked by treating PPAR-γ antagonist (GW9662). These results showed that ASA VI promote the transition of microglia cells from proinflammatory to anti-inflammatory by regulating PPAR-γ pathway.

Δ9 -Tetrahydrocannabinolic acid alleviates collagen-induced arthritis: Role of PPARγ and CB1 receptors.

Δ9 -Tetrahydrocannabinolic acid (Δ9 -THCA-A), the precursor of Δ9 -THC, is a non-psychotropic phytocannabinoid that shows PPARγ agonist activity. Here, we investigated the ability of Δ9 -THCA-A to modulate the classic cannabinoid CB1 and CB2 receptors and evaluated its anti-arthritis activity in vitro and in vivo. Cannabinoid receptors binding and intrinsic activity, as well as their downstream signalling, were analysed in vitro and in silico. The anti-arthritis properties of Δ9 -THCA-A were studied in human chondrocytes and in the murine model of collagen-induced arthritis (CIA). Plasma disease biomarkers were identified by LC-MS/MS based on proteomic and elisa assays. Functional and docking analyses showed that Δ9 -THCA-A can act as an orthosteric CB1 receptor agonist and also as a positive allosteric modulator in the presence of CP-55,940. Also, Δ9 -THCA-A seemed to be an inverse agonist for CB2 receptors. In vivo, Δ9 -THCA-A reduced arthritis in CIA mice, preventing the infiltration of inflammatory cells, synovium hyperplasia, and cartilage damage. Furthermore, Δ9 -THCA-A inhibited expression of inflammatory and catabolic genes on knee joints. The anti-arthritic effect of Δ9 -THCA-A was blocked by either SR141716 or T0070907. Analysis of plasma biomarkers, and determination of cytokines and anti-collagen antibodies confirmed that Δ9 -THCA-A mediated its activity mainly through PPARγ and CB1 receptor pathways. Δ9 -THCA-A modulates CB1 receptors through the orthosteric and allosteric binding sites. In addition, Δ9 -THCA-A exerts anti-arthritis activity through CB1 receptors and PPARγ pathways, highlighting its potential for the treatment of chronic inflammatory diseases such as rheumatoid arthritis.

Intermedin alleviates pathological cardiac remodeling by upregulating klotho

Cardiac remodeling is accompanied by cardiac hypertrophy, fibrosis, dysfunction, and eventually leading to heart failure. Intermedin (IMD), as a paracrine/autocrine peptide, has a protective effect in cardiovascular diseases. In this study, we elucidated the role and the underlying mechanism of IMD in pathological remodeling. Pathological remodeling mouse models were induced by abdominal aorta constriction for 4 weeks or angiotensin II (Ang II) infusion for 2 weeks in wildtype, IMD-overexpression, IMD-knockout and klotho-knockdown mice. Western blot, real-time PCR, histological staining, echocardiography and hemodynamics were used to detect the role of IMD in cardiac remodeling. Cardiac hypertrophy, fibrosis and dysfunction were significantly aggravated in IMD-knockout mice versus wildtype mice, and the expression of klotho was downregulated. Conversely, cardiac remodeling was alleviated in IMD-overexpression mice, and the expression of klotho was upregulated. Hypertension induced by Ang II infusion rather than abdominal aorta constriction was mitigated by IMD. However, the cardioprotective effect of IMD was blocked in klotho-knockdown mice. Similar results were found in cultured neonatal rat cardiomyocytes, which was pretreated with IMD before Ang II stimulation. Mechanistically, IMD inhibited the phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and the activity of calcineurin to protect against cardiac hypertrophy through upregulating klotho in vivo and in vitro. Furthermore, peroxisome proliferator-activated receptor γ (PPARγ) might mediate IMD upregulating klotho. In conclusion, pathological remodeling may be alleviated by endogenous IMD, which inhibits the expression of calcineurin and p-CaMKII by upregulating klotho via the PPARγ pathway. It suggested that IMD might be a therapeutic target for heart disease.

Active ingredients from oil by-products modulate spleen inflammatory and antioxidant response in pigs

Abstract Grape seed cakes (GSC) resulted from grape seed oil extraction represent a by-product rich in bioactive compounds such as polyphenols, polyunsaturated fatty acids, fibres, minerals, vitamins etc known for their beneficial anti-inflammatory, anti-microbial, anti-oxidative and immune-modulatory effects. In the present study, we have investigated the effects of dietary grape seed cakes bioactive compounds on several anti-inflammatory and antioxidative biomarkers in spleen of pigs during fattening phase. Twelve crossbred TOPIG hybrid fattening pigs were allocated to two experimental treatments: 1) commercial diet (control group) and 2) a diet including 5% grape seed cakes (GSC group) for 24 days. At the end of experimental period (day 24) pigs were sacrificed and spleen samples were collected and stored at –80°C until analysis. The results showed that GSC diet lowered the gene expression as well as the protein concentration of pro-inflammatory markers: interleukin 1 beta (IL-1β, -52.66%, p<0.05) and interferon gamma (IFN-γ, -42.13%, p<0.05) and had a tendency to decrease that of interleukin 6 (IL-6, -13.25%), tumour necrosis factor alpha (TNF-α, -9.06%) and interleukin 8 (IL-8, -11.08%) when compared to control diet confirming the anti-inflammatory properties of GSC’s active ingredients. The total splenic antioxidant capacity (TEAC) and gene expression of antioxidant enzymes (catalase-CAT and glutathione peroxidase-GPx) were higher in spleen of pigs fed GSC diet than in control group suggesting also the antioxidative potential of GSC. The results related to the molecular mechanism showed a higher expression of gene encoding for PPAR-γ and for Nrf2 in spleen of pigs receiving the GSC diet (Fc 1.81 and 1.58) suggesting that the anti-inflammatory and antioxidant effect of this diet is probably exerted by PPAR-γ and Nrf2 pathway. Further, other percent of dietary GSC inclusion need to be investigated in order to obtain a more complex response related to biomarkers which characterise the fattening/obesity process.

2310-PUB: Chronic Western Diets Initiate Fibrosis Progression in Nonalcoholic Fatty Liver of Male Mice Modifying the PPARγ Pathway via Mir-27b-5p Regulation

Increased fructose intake in Western diets contributes to metabolic diseases. However, the epigenetic mechanisms are mostly unknown. Here, six week-old C57BL/6J male and female mice were fed with a low-fat diet (LFD), high-fat diet (HFD), and high-fat high-fructose diet (HFD-HF) for 20 weeks. We determined that HFD-HF or HFD mice experienced significant metabolic dysregulation compared to the LFD. Metabolic changes in male mice were significantly dysregulated compared to female mice. HFD-HF and HDF male-specific responses included physiological/metabolic changes such as significant increased body weight, increased liver size, increased fasting glucose levels and downregulated PPARγ (P < 0.001), SCD1 (P < 0.05 to P < 0.01), and FAS (P < 0.05) protein expression. In contrast, female mice were less affected by HFD and HFD-HF. Interestingly, none of the groups exhibited less insulin sensitivity after 20 weeks of feeding when compared to LFD. As miR-27b contains a seed sequence in PPARγ, it was discovered that these changes are accompanied by male-specific upregulation of miR-27b-5p, which is even more pronounced in the HFD-HF group (P < 0.01 vs. LFD) compared to the HFD group (P < 0.05 vs. LFD). Other miR-27 subtypes were increased but not significantly. Fat ballooning in hepatocytes were increased in HFD fed mice compared to HFD-HF fed mice, however, the HFD-HF liver showed an increase in the number of small cells. Here, we concluded that our chronic western diet-composition administered for 20 weeks surpassed the nonalcoholic fatty liver (NAFL) stage and initiated liver fibrosis via miR-27b-5p-induced PPARγ downregulation. Disclosure J. Zhang: None. C. Powell: None. M.K. Kay: None. R. Sonkar: None. S. Meruvu: None. M. Choudhury: None. Funding Morris L. Lichtenstein, Jr. Medical Research Foundation

Protein Digests and Pure Peptides from Chia Seed (Salvia hispanica L) Prevented Adipogenesis and Its Associated Inflammation by Inhibition of PPAR-γ and NF-κB Pathways

Abstract Objectives To evaluate the mechanism of action of the effect of digested total proteins (DTP), albumin, and glutelin from chia seed to prevent and inhibit inflammation in 3T3-L1 adipocytes. Methods Preadipocytes (3T3-L1) were differentiated into mature adipocytes and received DTP, digested albumin, or glutelin (1 mg/ml) from chia seed together with conditioned medium (CM) from inflamed macrophages during 48 h (prevention), or the digested samples were added after 48 h of CM-stimulated inflammation (inhibition). ROS and cytokines secretion (IL-10, IL-12, IL-6, MCP-1, PGE2, and TNF-α) were analyzed by ELISA and lipid accumulation by oil red-O staining, triglyceride content, lipase activity and expression of proteins (PPAR-γ, SREBP1, FAS, LPL, COX-2, iNOS, and NF-κB) by western-blot. The interactions of peptides with FAS, MAGL, and PPAR-γ were evaluated in silico. Data analyses were performed in triplicate from two independent experiments by ANOVA and post-hoc of Tukey (P < 0.05). Results DTP and digested albumin and glutelin in both, prevention and inhibition of induced inflammation, decreased the expression of PPAR-γ more than 50% (P < 0.05). Digested samples reduced TNF-α secretion, ROS production, lipid accumulation, iNOS and COX-2 expression, especially glutelin (−71, −53, −15, −75, and -85%, respectively) on prevention of inflammation. Albumin digest inhibited NO and PGE2 (−42 and 64%, respectively). DTP reduced the lipase activity (−13%), triglyceride content (−27%), and NF-κB expression (−48%) (P < 0.05). On inhibition of inflammation, only SREBP-1 expression was reduced more than 33% (P < 0.05) by every digested protein. DTP was effective to reduce LPL (-32%), FAS (−29%), iNOS (−52%), and COX-2 (−66%) expression, as well as NO secretion (−15%), and triglyceride content (−18%) (P < 0.05). Peptides TGPSPTAGPPAPGGGTH and YLGAHPGTAN, from digested albumin, showed the highest interaction with PPAR-γ (−9.1 kcal/mol) and MAGL (−7.8 kcal/mol), respectively. Peptide APSPPVLGPP from DTP, showed the highest interaction with FAS (−9.8 kcal/mol). Conclusions Digested samples from chia seed were effective in preventing and even inhibiting inflammation in adipocytes by inhibition of PPAR-γ and NF-κB pathways which highlight the effectiveness these digested proteins against obesity complications. Funding Sources CNPq and CAPES (Brazil), and NIFA HATCH (USA).