Effects of α-Lipoic Acid on Phagocytosis of Oligomeric Beta-Amyloid1–42 in BV-2 Mouse Microglial Cells

Background and objectives: This study aimed to investigate the enhancing effect of vitamin-like alpha-lipoic acid (ALA) on phagocytosis of oligomeric beta-amyloid (oAβ)1–42 in BV-2 mouse microglial cells.Methods: An in vitro model was established to investigate phagocytosis of oAβ1–42 in BV-2 cells. Transmission electron microscopy images indicated that the morphology of prepared oAβ1–42 was spherical particles. BV-2 cells treated with ALA were incubated with 5(6)-carboxyfluorescein-labeled oAβ1–42 (FAM-oAβ1–42) for 24 h, followed by flow cytometer analysis, western blotting, real-time quantitative PCR, and immunocytochemistry (ICC) analysis to assess the in vitro phagocytosis ability of oAβ1–42.Results: Alpha-lipoic acid significantly increased messenger RNA (mRNA) expression of the CD36 receptor in BV-2 cells. ICC analysis showed that ALA significantly elevated CD36 protein expression in BV-2 cells both with and without oAβ1–42 treatment. Results from the flow cytometry analysis indicated that the CD36 receptor inhibitor significantly attenuated ALA-promoted phagocytosis of FAM-oAβ1–42 in BV-2 cells. Moreover, ICC analysis revealed that ALA caused the translocation of peroxisome proliferator-activated receptor-γ (PPAR-γ), which is known to regulate the expression of CD36 mRNA in BV-2 cells. ALA also elevated both the mRNA and protein expression of cyclooxygenase-2 (COX-2), which is a key enzyme involved in the synthesis of 15-deoxy-Δ12,14-prostaglandin J2 in BV-2 cells.Conclusion: We postulated that ALA enhances oAβ1–42 phagocytosis by upregulating the COX-2/15-deoxy-Δ12,14-prostaglandin J2/PPAR-γ/CD36 pathway in BV-2 cells. Finally, future studies should be conducted with an in vivo study to confirm the findings.

Intestinal microbe-dependent ω3 lipid metabolite αKetoA prevents inflammatory diseases in mice and cynomolgus macaques

Dietary ω3 fatty acids have important health benefits and exert their potent bioactivity through conversion to lipid mediators. Here, we demonstrate that microbiota play an essential role in the body’s use of dietary lipids for the control of inflammatory diseases. We found that amounts of 10-hydroxy-cis-12-cis-15-octadecadienoic acid (αHYA) and 10-oxo-cis-12-cis-15-octadecadienoic acid (αKetoA) increased in the feces and serum of specific-pathogen-free, but not germ-free, mice when they were maintained on a linseed oil diet, which is high in α-linolenic acid. Intake of αKetoA, but not αHYA, exerted anti-inflammatory properties through a peroxisome proliferator-activated receptor (PPAR)γ-dependent pathway and ameliorated hapten-induced contact hypersensitivity by inhibiting the development of inducible skin-associated lymphoid tissue through suppression of chemokine secretion from macrophages and inhibition of NF-κB activation in mice and cynomolgus macaques. Administering αKetoA also improved diabetic glucose intolerance by inhibiting adipose tissue inflammation and fibrosis through decreased macrophage infiltration in adipose tissues and altering macrophage M1/M2 polarization in mice fed a high-fat diet. These results collectively indicate that αKetoA is a novel postbiotic derived from α-linolenic acid, which controls macrophage-associated inflammatory diseases and may have potential for developing therapeutic drugs as well as probiotic food products.

Kronik Hastalıklarda İnflamasyonun Rolü, Omega-3 Yağ Asitleri ve Epigenetik Yolaklar

Diyet bileşenlerinin epigenomu etkileyerek kronik hastalıklar üzerinde etkilerinin olduğu bilinmektedir. Bu bilgilerin ışığında, beslenme ve epigenetik arasındaki ilişkileri inceleyen bir bilim dalı olan nutriepigenomik kronik hastalıkların tedavisinde umut verici bir alan olmuştur. Epigenom üzerinde etkileri olduğu bilinen omega-3 yağ asitleri, sadece önemli bir enerji kaynağı değil, aynı zamanda transkripsiyon faktörlerinin ligandları olarak hareket edebilmekte, böylelikle metabolik düzenleyiciler olarak da görev yapmaktadır. Yapılan araştırmalar omega-3 yağ asitlerinin, çeşitli mekanizmalarla gen ekspresyonunu değiştirebileceğini, böylelikle birçok kronik hastalığın patogenezine katkıda bulunan kronik inflamasyon üzerinde olumlu etkilerinin olabileceğini göstermektedir. Özellikle eikozapentaenoik asit ve dokosaheksaenoik asit gibi omega-3 yağ asitlerinin bazı önemli moleküler hücre mekanizmalarını kontrol ettiği, böylelikle inflamasyonla ilişkili hastalıklarda anti-inflamatuvar etki oluşturabileceği bildirilmiştir. Aynı zamanda, bu yağ asitlerinin DNA metilasyonu gibi epigenetik belirteçlerde değişikliklere yol açarak da bahsi geçen olumlu etkileri sağlayabileceği belirtilmektedir. Literatür, omega-3 yağ asitlerinin, çeşitli nükleer reseptör ve transkripsiyon faktörleri ile etkileşime girerek bazı pro-inflamatuvar genlerin ekspresyonunu modüle edebileceği, böylelikle aktivasyonlarında değişikliklere yol açabileceğini göstermektedir. Genel olarak omega-3 yağ asitlerinin, inflamasyon üzerinde etkin rol oynayan nükleer faktör κB (NFκB), PPAR- γ (PPARG) ve G proteinine bağlı reseptör (GPR120) ile etkileşime girerek anti-inflamatuvar etki yaratabileceği bilinmektedir. Bu mekanizmalar karmaşıktır. Bu derlemenin amacı, omega-3 yağ asitlerinin inflamatuvar süreçleri etkilediği epigenetik mekanizmaları açıklamaktır.

The PPAR-γ agonist pioglitazone exerts proinflammatory effects in bronchial epithelial cells during acute Pseudomonas aeruginosa pneumonia

Pseudomonas (P.) aeruginosa is a common respiratory pathogen that causes injurious airway inflammation during acute pneumonia. PPAR (peroxisome proliferator-activated receptor)-γ is involved in the regulation of metabolic and inflammatory responses in different cell types and synthetic agonists of PPAR-γ exert anti-inflammatory effects on myeloid cells in vitro and in models of inflammation in vivo. We sought to determine the effect of the PPAR-γ agonist pioglitazone on airway inflammation induced by acute P. aeruginosa pneumonia, focusing on bronchial epithelial cells. Mice pretreated with pioglitazone or vehicle (-24 and -1 hour) were infected with P. aeruginosa via the airways. Pioglitazone treatment was associated with increased expression of chemokine (Cxcl1, Cxcl2, Ccl20) and cytokine genes (Tnfa, Il6, Cfs3) in bronchial brushes obtained 6 hours after infection. This proinflammatory effect was accompanied by increased expression of Hk2 and Pfkfb3, genes encoding rate limiting enzymes of glycolysis; concurrently, the expression of Sdha, important for maintaining metabolite flux in the tricarboxylic acid cycle, was reduced in bronchial epithelial cells of pioglitazone treated-mice. Pioglitazone inhibited bronchoalveolar inflammatory responses measured in lavage fluid. These results suggest that pioglitazone exerts a selective proinflammatory effect on bronchial epithelial cells during acute P. aeruginosa pneumonia, possibly by enhancing intracellular glycolysis.

PPAR-γ Promotes the Polarization of Rat Retinal Microglia To M2 Phenotype By Regulating the Expression of CD200-CD200R1 Under Hypoxia

Objective Based on recent reports, peroxisome proliferator-activated receptor-γ (PPAR-γ) could promote microglial M2 polarization to inhibit inflammation. However, the specific molecular mechanisms instigate the anti-inflammatory ability of PPAR-γ in microglia have not been expounded. In the present study, we explored the molecular mechanisms of the anti-inflammatory effects of PPAR-γ in hypoxia-stimulated rat microglial cells. Methods shRNA expressing lentivirus was used to knock down PPAR-γ and CD200 genes. The hypoxia-induced polarization markers release (M1: iNOS, IL-1β, IL-6 and TNF-α; M2: Arg-1, YM1, IL-4 and IL-10) was assessed by RT-PCR, while PPAR-γ-related signals (PPAR-γ, PPAR-γ in cytoplasm or nucleus, CD200 and CD200Rs) were monitored by western blot and RT-PCR. Results Hypoxia enhanced PPAR-γ and CD200 expressions in microglial cells. In addition, PPAR-γ agonist 15d-PGJ2 elevated CD200 and CD200R1 expressions, while sh-PPAR-γ (PPAR-γ knock-down) had just the opposite effect. Following hypoxia, expressions of M1 markers increased significantly, while those of M2 markers decreased, and the above effects were attenuated by 15d-PGJ2. Conversely, knocking down PPAR-γ or CD200 inhibited the polarization of microglial cells to M2 phenotype. Conclusion Results demonstrated that PPAR-γ performed an anti-inflammatory function in hypoxia-stimulated microglial cells by promoting their polarization to M2 phenotype via CD200-CD200R1 pathway.

Monocytes and pyrophosphate promote mesenchymal stem cell viability and early osteogenic differentiation

Pyrophosphate-containing calcium phosphate implants promote osteoinduction and bone regeneration. The role of pyrophosphate for inflammatory cell-mesenchymal stem cell (MSC) cross-talk during osteogenesis is not known. In the present work, the effects of lipopolysaccharide (LPS) and pyrophosphate (PPi) on primary human monocytes and on osteogenic gene expression in human adipose-derived MSCs were evaluated in vitro, using conditioned media transfer as well as direct effect systems. Direct exposure to pyrophosphate increased nonadherent monocyte survival (by 120% without LPS and 235% with LPS) and MSC viability (LDH) (by 16–19% with and without LPS). Conditioned media from LPS-primed monocytes significantly upregulated osteogenic genes (ALP and RUNX2) and downregulated adipogenic (PPAR-γ) and chondrogenic (SOX9) genes in recipient MSCs. Moreover, the inclusion of PPi (250 μM) resulted in a 1.2- to 2-fold significant downregulation of SOX9 in the recipient MSCs, irrespective of LPS stimulation or culture media type. These results indicate that conditioned media from LPS-stimulated inflammatory monocytes potentiates the early MSCs commitment towards the osteogenic lineage and that direct pyrophosphate exposure to MSCs can promote their viability and reduce their chondrogenic gene expression. These results are the first to show that pyrophosphate can act as a survival factor for both human MSCs and primary monocytes and can influence the early MSC gene expression.

Effectiveness of Yoga, Fast of Dawood, Green Tea and Apple Juice as Suppressors of PPAR-γ, C/EBP-α, and SREBP-c for Management of Obesity on Adolescents

Obesity is a condition that can increase the risk of some diseases such as reduced brain capacity, dyspnea, skin irritation, hypertension, and diabetes. Proper treatment is needed to overcome the problems of obesity. The objective of this study was to investigate the effectiveness of Yoga, fast of Dawood, Green Tea, and Apple juice to suppressor PPAR-γ gene activity, C / EBPα, and SREBP-c to manage obesity in adolescents. The method used in this study was a literature review from journal publications through the database ScienceDirect, PUBMED, and google scholar, and the criteria were Indonesian and English with a range of publication years 2014-2019. Nine main articles were used as references in this study. These articles proved that yoga therapy could maintain the balance and health of the physical, emotional, and spiritual dimensions, and Fast of Dawood can limit the amount of calorie intake at a particular time. Moreover, by consuming green tea as a source of polyphenol derivatives and apples with high of flavanol, anthocyanidin, dihydrochalcones, and hydroxycinnamic acid could decrease adolescents' body weight. Yoga and Fast of Dawood exercise can reduce adipogenesis and induce reverse cholesterol transport, cellular cholesterol released, reduced pro-inflammatory cytokines dan decreased the incidence of obesity.