scholarly journals Inhibition of PPARγ in myeloid-lineage cells induces systemic inflammation, immunosuppression, and tumorigenesis

Blood ◽  
2012 ◽  
Vol 119 (1) ◽  
pp. 115-126 ◽  
Author(s):  
Lingyan Wu ◽  
Cong Yan ◽  
Magdalena Czader ◽  
Oded Foreman ◽  
Janice S. Blum ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Suppressor Cells ◽  
Dominant Negative ◽  
Peroxisome Proliferator ◽  
Myeloid Lineage ◽  
Peroxisome Proliferator Activated Receptor ◽  
Anti Inflammatory ◽  
Spleen And Lymph Nodes

Abstract Peroxisome proliferator–activated receptor-γ (PPARγ) is an anti-inflammatory molecule. To study its biologic function in myeloid cells, dominant-negative PPARγ (dnPPARγ) was overexpressed in a myeloid-specific bitransgenic mouse model. In this bitransgenic system, overexpression of the dnPPARγ-Flag fusion protein in myeloid-lineage cells abnormally elevated frequencies and total numbers of IL-7Rα−Lin−c-Kit+Sca-1−, Lin−/Scal+/c-Kit+, common myeloid, and granulocyte-monocyte progenitor populations in the BM. dnPPARγ overexpression led to up-regulation of IL-1β, IL-6, and TNFα in the blood plasma. As a result, CD11b+Ly6G+ cells were systemically increased in association with activation of Stat3, NF-κB, Erk1/2, and p38 molecules. Myeloid-derived suppressor cells (MDSCs) inhibited the proliferation and lymphokine production of wild-type CD4+ T cells in vitro. CD4+ T cells from doxycycline-treated bitransgenic mice displayed reduced proliferation and lymphokine release. Both CD4+ and CD8+ T-cell populations were decreased in doxycycline-treated bitransgenic mice. Multiple forms of carcinoma and sarcoma in the lung, liver, spleen, and lymph nodes were observed in doxycycline-treated bitransgenic mice. BM transplantation revealed that a myeloid-autonomous defect was responsible for MDSC expansion, immunosuppression, and tumorigenesis in these mice. These studies suggest that anti-inflammatory PPARγ in myeloid-lineage cells plays a key role in controlling pro-inflammatory cytokine synthesis, MDSC expansion, immunosuppression, and the development of cancer.

scholarly journals Betamethasone induces potent immunosuppression and reduces HIV infection in a PBMC in vitro model

2020 ◽  
Vol 69 (1) ◽  
pp. 28-40 ◽  
Author(s):  
Ross Cromarty ◽  
Alexander Sigal ◽  
Lenine Julie Liebenberg ◽  
Lyle Robert Mckinnon ◽  
Salim Safurdeen Abdool Karim ◽  
...  
Keyword(s):  
T Cells ◽  
Hiv Infection ◽  
Immune Activation ◽  
Cd4 T Cells ◽  
Drug Targets ◽  
Complex Nature ◽  
Peripheral Blood Mononuclear ◽  
Established Risk Factor ◽  
Anti Inflammatory

Genital inflammation is an established risk factor for increased HIV acquisition risk. Certain HIV-exposed seronegative populations, who are naturally resistant to HIV infection, have an immune quiescent phenotype defined by reduced immune activation and inflammatory cytokines at the genital tract. Therefore, the aim of this study was to create an immune quiescent environment using immunomodulatory drugs to mitigate HIV infection. Using an in vitro peripheral blood mononuclear cell (PBMC) model, we found that inflammation was induced using phytohemagglutinin and Toll-like receptor (TLR) agonists Pam3CSK4 (TLR1/2), lipopolysaccharide (LPS) (TLR4) and R848 (TLR7/8). After treatment with anti-inflammatory drugs, ibuprofen (IBF) and betamethasone (BMS), PBMCs were exposed to HIV NL4-3 AD8. Multiplexed ELISA was used to measure 28 cytokines to assess inflammation. Flow cytometry was used to measure immune activation (CD38, HLA-DR and CCR5) and HIV infection (p24 production) of CD4+ T cells. BMS potently suppressed inflammation (soluble cytokines, p<0.05) and immune activation (CD4+ T cells, p<0.05). BMS significantly reduced HIV infection of CD4+ T cells only in the LPS (0.98%) and unstimulated (1.7%) conditions (p<0.02). In contrast, IBF had minimal anti-inflammatory and immunosuppressive but no anti-HIV effects. BMS demonstrated potent anti-inflammatory effects, regardless of stimulation condition. Despite uniform immunosuppression, BMS differentially affected HIV infection according to the stimulation conditions, highlighting the complex nature of these interactions. Together, these data underscore the importance of interrogating inflammatory signaling pathways to identify novel drug targets to mitigate HIV infection.

scholarly journals Anti-Inflammatory Effects of Fucoxanthinol in LPS-Induced RAW264.7 Cells through the NAAA-PEA Pathway

Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 222 ◽  
Author(s):  
Wenhui Jin ◽  
Longhe Yang ◽  
Zhiwei Yi ◽  
Hua Fang ◽  
Weizhu Chen ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Inhibitory Effect ◽  
Inflammatory Factors ◽  
Lipid Mediator ◽  
Peroxisome Proliferator ◽  
Necrosis Factor Alpha ◽  
Peroxisome Proliferator Activated Receptor ◽  
Tnf Α ◽  
Anti Inflammatory

Palmitoylethanolamide (PEA) is an endogenous lipid mediator with powerful anti-inflammatory and analgesic functions. PEA can be hydrolyzed by a lysosomal enzyme N-acylethanolamine acid amidase (NAAA), which is highly expressed in macrophages and other immune cells. The pharmacological inhibition of NAAA activity is a potential therapeutic strategy for inflammation-related diseases. Fucoxanthinol (FXOH) is a marine carotenoid from brown seaweeds with various beneficial effects. However, the anti-inflammatory effects and mechanism of action of FXOH in lipopolysaccharide (LPS)-stimulated macrophages remain unclear. This study aimed to explore the role of FXOH in the NAAA–PEA pathway and the anti-inflammatory effects based on this mechanism. In vitro results showed that FXOH can directly bind to the active site of NAAA protein and specifically inhibit the activity of NAAA enzyme. In an LPS-induced inflammatory model in macrophages, FXOH pretreatment significantly reversed the LPS-induced downregulation of PEA levels. FXOH also substantially attenuated the mRNA expression of inflammatory factors, including inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), and markedly reduced the production of TNF-α, IL-6, IL-1β, and nitric oxide (NO). Moreover, the inhibitory effect of FXOH on NO induction was significantly abolished by the peroxisome proliferator-activated receptor α (PPAR-α) inhibitor GW6471. All these findings demonstrated that FXOH can prevent LPS-induced inflammation in macrophages, and its mechanisms may be associated with the regulation of the NAAA-PEA-PPAR-α pathway.

scholarly journals Apple Flavonols Mitigate Adipocyte Inflammation and Promote Angiogenic Factors in LPS- and Cobalt Chloride-Stimulated Adipocytes, in Part by a Peroxisome Proliferator-Activated Receptor-γ-Dependent Mechanism

Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1386 ◽  
Author(s):  
Danyelle M. Liddle ◽  
Meaghan E. Kavanagh ◽  
Amanda J. Wright ◽  
Lindsay E. Robinson
Keyword(s):  
Mrna Expression ◽  
Cobalt Chloride ◽  
Nuclear Factor Κb ◽  
Diglycidyl Ether ◽  
Low Grade ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Anti Inflammatory

Adipose tissue (AT) expansion induces local hypoxia, a key contributor to the chronic low-grade inflammation that drives obesity-associated disease. Apple flavonols phloretin (PT) and phlorizin (PZ) are suggested anti-inflammatory molecules but their effectiveness in obese AT is inadequately understood. Using in vitro models designed to reproduce the obese AT microenvironment, 3T3-L1 adipocytes were cultured for 24 h with PT or PZ (100 μM) concurrent with the inflammatory stimulus lipopolysaccharide (LPS; 10 ng/mL) and/or the hypoxia mimetic cobalt chloride (CoCl2; 100 μM). Within each condition, PT was more potent than PZ and its effects were partially mediated by peroxisome proliferator-activated receptor (PPAR)-γ (p < 0.05), as tested using the PPAR-γ antagonist bisphenol A diglycidyl ether (BADGE). In LPS-, CoCl2-, or LPS + CoCl2-stimulated adipocytes, PT reduced mRNA expression and/or secreted protein levels of inflammatory and macrophage chemotactic adipokines, and increased that of anti-inflammatory and angiogenic adipokines, which was consistent with reduced mRNA expression of M1 polarization markers and increased M2 markers in RAW 264.7 macrophages cultured in media collected from LPS + CoCl2-simulated adipocytes (p < 0.05). Further, within LPS + CoCl2-stimulated adipocytes, PT reduced reactive oxygen species accumulation, nuclear factor-κB activation, and apoptotic protein expression (p < 0.05). Overall, apple flavonols attenuate critical aspects of the obese AT phenotype.

Inhibition of the transcription factors AP-1 and NF-κB in CD4 T cells by peroxisome proliferator-activated receptor γ ligands

2001 ◽  
Vol 1 (4) ◽  
pp. 803-812 ◽  
Author(s):  
Ping Wang ◽  
Per O. Anderson ◽  
Shangwu Chen ◽  
Kajsa M. Paulsson ◽  
Hans-Olov Sjögren ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factors ◽  
Cd4 T Cells ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

scholarly journals The role of the amino-terminal domain in the interaction of unliganded peroxisome proliferator-activated receptor γ-2 with nuclear receptor co-repressor

2010 ◽  
Vol 45 (3) ◽  
pp. 133-145 ◽  
Author(s):  
Sadako Suzuki ◽  
Shigekazu Sasaki ◽  
Hiroshi Morita ◽  
Yutaka Oki ◽  
Daisuke Turiya ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Nuclear Receptor ◽  
Thyroid Hormone Receptor ◽  
Dominant Negative ◽  
Peroxisome Proliferator ◽  
Wild Type ◽  
Peroxisome Proliferator Activated Receptor ◽  
Amino Terminal

Peroxisome proliferator-activated receptor γ-2 (PPARG2) is a ligand-dependent transcriptional factor involved in the pathogenesis of insulin resistance. In the presence of a ligand, PPARG2 associates with co-activators, while it recruits co-repressors (CoRs) in the absence of a ligand. It has been reported that the interaction of liganded PPARG2 with co-activators is regulated by the amino-terminal A/B domain (NTD) via inter-domain communication. However, the role of the NTD is unknown in the case of the interaction between unliganded PPARG2 and CoRs. To elucidate this, total elimination of the influence of ligands is required, but the endogenous ligands of PPARG2 have not been fully defined. PPARG1-P467L, a naturally occurring mutant of PPARG1, was identified in a patient with severe insulin resistance. Reflecting its very low affinity for various ligands, this mutant does not have transcriptional activity in the PPAR response element, but exhibits dominant negative effects (DNEs) on liganded wild-type PPARG2-mediated transactivation. Using the corresponding PPARG2 mutant, PPARG2-P495L, we evaluated the role of the NTD in the interaction between unliganded PPARG2 and CoRs. Interestingly, the DNE of PPARG2-P495L was increased by the truncation of its NTD. NTD deletion also enhanced the DNE of a chimeric receptor, PT, in which the ligand-binding domain of PPARG2 was replaced with that of thyroid hormone receptor β-1. Moreover, NTD deletion facilitated the in vitro binding of nuclear receptor CoR with wild-type PPARG2, mutant P495L, and the PT chimera (PPARG2-THRB). Inter-domain communication in PPARG2 regulates not only ligand-dependent transactivation but also ligand-independent silencing.

scholarly journals Mechanism of the Anti-inflammatory Effect of Curcumin: PPAR-γActivation

PPAR Research ◽  
2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
Asha Jacob ◽  
Rongqian Wu ◽  
Mian Zhou ◽  
Ping Wang
Keyword(s):  
Clinical Studies ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Commercial Grade ◽  
Inflammatory Agent ◽  
Anticancer Effects ◽  
Anti Inflammatory ◽  
Inflammatory Effect

Curcumin, the phytochemical component in turmeric, is used as a dietary spice and a topical ointment for the treatment of inflammation in India for centuries. Curcumin (diferuloylmethane) is relatively insoluble in water, but dissolves in acetone, dimethylsulphoxide, and ethanol. Commercial grade curcumin contains 10–20% curcuminoids, desmethoxycurcumin, and bisdesmethoxycurcumin and they are as effective as pure curcumin. Based on a number of clinical studies in carcinogenesis, a daily oral dose of 3.6 g curcumin has been efficacious for colorectal cancer and advocates its advancement into Phase II clinical studies. In addition to the anticancer effects, curcumin has been effective against a variety of disease conditions in both in vitro and in vivo preclinical studies. The present review highlights the importance of curcumin as an anti-inflammatory agent and suggests that the beneficial effect of curcumin is mediated by the upregulation of peroxisome proliferator-activated receptor-γ(PPAR-γ) activation.

scholarly journals PPAR-γAgonist Alleviates Liver and Spleen Pathology via Inducing Treg Cells duringSchistosoma japonicumInfection

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yuxiao Zhu ◽  
Yangyue Ni ◽  
Ran Liu ◽  
Min Hou ◽  
Bingya Yang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Schistosoma Japonicum ◽  
Cellular Proliferation ◽  
Inflammatory Responses ◽  
Treg Cells ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Tissue Samples

Background. Peroxisome proliferator-activated receptor- (PPAR-)γplays critical roles in human metabolic disorders and has recently been implicated as a regulator of cellular proliferation and inflammatory responses. Regulatory T cells (Tregs), which express high levels of PPAR-γprotein, have the ability to maintain immune tolerance to self-antigens and regulate immune response toSchistosomainfection. However, mechanisms involved in the resolution of these responses are elusive.Methods. Liver and spleen tissue samples inSchistosoma japonicum-infected mice after administration of pioglitazone (a PPAR-γagonist) were collected. The hepatic and splenic pathologies were detected by H&E and Masson staining. The percentages of Th1/2 and Treg cells in the liver and spleen of each mouse were determined using flow cytometry. Levels of gene expression of PPAR-γand Foxp3 in tissues or cells were determined using real-time PCR (RT-PCR). Macrophages were treated with pioglitazonein vitroor cocultured with normal purified CD4+T cells for detecting Treg cells by flow cytometry. The interactions of PPAR-γwith Foxp3 in CD4+T cells were detected by coimmunoprecipitation.Results. Administration of pioglitazone resulted in the prevention of the development of hepatic and splenic pathologies. Activation of PPAR-γby pioglitazone resulted in increased percentages of CD4+CD25+Foxp3+Treg cells and decreased percentages of CD3+CD4+IFN-γ+and CD3+CD4+IL-4+cells in the liver and spleen ofSchistosoma japonicum-infected mice. In addition, the PPAR-γagonist can induce Treg cellsin vitrodirectly or by modulating the macrophage’s function indirectly. Furthermore, through interaction with Foxp3 in CD4+T cells, the PPAR-γagonist can promote the expression of Foxp3; however, the inhibitor of PPAR-γweakened the expression of Foxp3 by modifying the coexpression of Foxp3 and PPAR-γ.Conclusions. Our study reveals a previously unrecognized role for PPAR-γ/Foxp3 signaling in regulating the immunopathology that occurs duringSchistosomainfection through induction of Treg cells.

scholarly journals Potential role of MRN-100, an iron-based compound, in upregulating production of cytokine IL-10 in human dendritic cells to promote an anti-inflammatory response in vitro

2019 ◽  
Vol 33 ◽  
pp. 205873841984493
Author(s):  
Mamdooh H Ghoneum ◽  
James K Gimzewski ◽  
Aya D Ghoneum ◽  
Sudhanshu Agrawal
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Cd4 T Cells ◽  
Inflammatory Cytokine ◽  
Enzyme Linked Immunosorbent Assay ◽  
Functional Assay ◽  
Iron Based ◽  
Anti Inflammatory ◽  
Human Dendritic Cells

The hydroferrate fluid MRN-100, an iron-based compound with potent antioxidant characteristics, was examined to identify its possible anti-inflammatory effects on human dendritic cells (DCs) in vitro. Human monocyte–derived DCs were treated with MRN-100 at two concentrations (50 and 100 μL/mL) for 24 h and then stimulated with or without lipopolysaccharides (LPS). The expression of DC maturation markers was assessed by flow cytometry and the production of cytokines was determined by enzyme-linked immunosorbent assay (ELISA). Functional assay was performed by co-culturing MRN-100-treated and untreated DCs with allogeneic naïve CD4+ T cells and assaying the T cells’ cytokine production. Results show that treatment with MRN-100 significantly upregulated the co-stimulatory molecules CD80 and CD86 and increased human leukocyte antigen-DR (HLA-DR) though not significantly. MRN-100 treatment also significantly increased the production of the anti-inflammatory cytokine interleukin (IL)-10. On the other hand, MRN-100 significantly induced the secretion of pro-inflammatory cytokines such as IL-6 only at high concentrations. Furthermore, DCs pretreated with MRN-100 and either stimulated or not with LPS were able to prime CD4+ T cells to secrete significant amounts of IL-10 while inhibiting the secretion of pro-inflammatory cytokine tumor necrosis factor (TNF)-α. These results indicate that MRN-100 is a powerful anti-inflammatory agent that promotes the generation of an anti-inflammatory immune response in vitro. MRN-100 could be beneficial for treating patients with inflammatory diseases, including arthritis and type 1 diabetes, and its potential benefits should be examined in clinical trials.

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