La sucralosa promueve la polarización a macrófagos proinflamatorios M1

RESUMEN La sucralosa es un edulcorante no calórico de amplio consumo a nivel mundial, es considerado como un aditivo seguro, debido a que es eliminado en periodos cortos de tiempo. Recientemente se evidenció su bioacumulación en tejido adiposo, donde se encuentran inmersos macrófagos, células del sistema inmune involucradas en el desarrollo de la inflamación sistémica de bajo grado. A la fecha, no se cuenta con suficiente información para demostrar si los edulcorantes potencian los procesos inflamatorios alterando la función de células presentes en tejido y/o contribuyen en el desarrollo de patologías metabólicas. Por lo anterior, en nuestro trabajo se evaluó el efecto de la sucralosa en la viabilidad de los macrófagos diferenciados de la línea celular monocítica THP-1, por azul de tripán y ensayos de MTT, así como su efecto en la polarización M1/M2 por PCR según la expresión de IRF4, IRF5, STAT1, STAT6, perfil de expresión de IL-6, IL-12, TNF-α, TGF-β, IL-10 y SOCS3 por qPCR, y la cuantificación de la quimiocina IP-10 por ELISA. Los resultados indicaron que la sucralosa no tiene efectos citotóxicos, pero disminuye el número de células viables metabólicamente activas determinadas por MTT de manera dependiente de la concentración. La sucralosa incrementa la concentración de la quimiocina IP-10 y la expresión génica del factor de transcripción IRF5 y disminuye la expresión de IRF4 y STAT6, favoreciendo la polarización hacia poblaciones M1. La bioacumulación de sucralosa en tejido adiposo, y su interacción con macrófagos, podría inducir su polarización a M1.

ABSTRACT Sucralose is a non-nutritive sweetener widely consumed worldwide; it is considered a safe additive because it is eliminated quickly. Recently its bioaccumulation in adipose tissue was evidenced, where macrophages, cells of the immune system involved in developing low-grade systemic inflammation, are found. To date, there is a paucity of information regarding whether sweeteners potentiate inflammatory processes by altering the function of cells present in tissue and/or contribute to the development of metabolic pathologies. We evaluate the effect of sucralose on the viability of differentiated macrophages of the monocytic cell line THP-1, by trypan blue and MTT assays, respectively, as well as its effect on M1/ M2 by PCR according to the expression of IRF4, IRF5, STAT1, STAT6, expression profile of IL6, IL-12, TNF-α, TGF-β, IL-10 and SOCS3 by qPCR, and the quantification of the chemokine IP-10 by ELISE. The results indicated that sucralose has no cytotoxic effects but decreases the number of metabolically active viable cells determined by MTT of macrophages in a concentration-dependent manner. Sucralose increased the concentration of the chemokine IP-10 and the gene expression of the transcription factors IRF5 and decreased the expression of IRF4 and STAT 6 gene expression, favoring polarization towards M1 populations. The bioaccumulation of sucralose in adipose tissue, and its interaction with macrophages, could induce its polarization to M1.

Dental pulp stem cell-derived apoptotic bodies regulate macrophage polarization and inflammatory response / 口腔疾病防治

Objective@#To investigate the effects of apoptotic bodies (ABs) derived from dental pulp stem cells (DPSCs) on macrophage polarization and inflammation response in vivo. @*Methods @#Human DPSCs were extracted, cultured and identified. Staurosporine was used to apoptosis induction and differential methods were performed for ABs identification. The in vitro cultured macrophages were divided into 3 groups: solvent control, lipopolysaccharide (LPS), and the LPS+ABs. The macrophages were stimulated with LPS to induce inflammation followed by ABs treatment. In the untreated group, macrophages were added with an equal amount of solvent. The specific uptake of ABs by macrophages, the expression level of CD206 and the levels of inflammatory cytokines were analyzed. The mouse models of cutaneous wounds and dextran sulfate sodium (DSS)-induced colitis were established, and the mice were randomly divided into 3 groups: the PBS-treated group, the DPSCs-treated group, and the ABs-treated group. The mice were injected with the same volume of PBS, DPSCs and ABs, respectively. The body weight, histological pathology, the expression levels of CD206 and cytokines, and the extent of tissue regeneration were measured.@* Results @#DPSCs and ABs derived from DPSCs were successfully isolated and characterized. ABs could be taken up by macrophage. While lipopolysaccharide(LPS) induced production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), ABs significantly reduced the levels of these pro-inflammatory cytokines and increased the expression of transforming growth factor-β (TGF-β) and CD206 (P < 0.01). In the cutaneous inflammatory wound model, the wound closure rate in mice intravenously injected with ABs was significantly accelerated (P < 0.05). The administration of ABs markedly reduced the pro-inflammatory factors levels and increased the CD206+ cell number. In the colitis model, treatment with ABs markedly reduced the loss in bodyweight (P < 0.05), recovered the colon length (P < 0.01), and significantly increased the CD206+ cell number.@* Conclusion@# DPSCs-derived ABs could enhance macrophage M2 polarization and attenuate inflammation. Therefore, ABs could be used as a promising cell replacement for inflammatory regulation and tissue regeneration.

Effect of fasudil on experimental autoimmune neuritis and its mechanisms of action

This study aimed to investigate the therapeutic effect of fasudil on treating experimental autoimmune neuritis (EAN). Twenty-four EAN mice were randomly assigned to fasudil treatment (Fasudil group) or saline treatment (EAN model group) for 28 days. Clinical symptom score was evaluated every other day; inflammatory cell infiltration, demyelination, anti-myelin basic protein (MBP), inflammatory cytokines, inducible nitric oxide synthase (iNOS), and arginase-1 were detected in sciatic nerves at day 28. Th1, Th2, Th17, and Tregs proportions in splenocytes were detected at day 28. Clinical symptom score was found to be attenuated in the Fasudil group compared to the EAN model group from day 12 to day 28. Sciatic nerve inflammatory cell counts by HE staining and demyelination by luxol fast blue staining were both reduced, while MBP was increased in the Fasudil group compared to the EAN model group at day 28. Interferon γ (IFN-γ) and interleukin (IL)-17 were reduced, while IL-4 and IL-10 were elevated in the Fasudil group at day 28. Sciatic nerve M1 macrophages marker iNOS was decreased while M2 macrophages marker arginase-1 was increased in the Fasudil group at day 28. CD4+IFN-γ+ (Th1) and CD4+IL-17+ (Th17) cell proportions were both decreased, CD4+IL-4+ (Th2) cell proportion was similar, while CD25+FOXP3+ (Treg) cell proportion in splenocytes was increased in the Fasudil group. In summary, fasudil presented a good therapeutic effect for treating EAN by attenuating Th1/Th17 cells and promoting Tregs activation as well as M2 macrophages polarization.

AKT/mTOR/STATs signaling pathway regulates various immune cells that mediate MS / 医学研究生学报

AKT/mTOR/STATs signaling pathway not only plays an important role in tumor growth, but also in the regulation of immune system. Activated AKT promotes the activation of downstream signaling pathways mTORC1 and mTORC2 through phosphorylation. mTOR is currently being considered as an important regulator of immune system and plays an important role in regulating the function and metabolism of various immune cells. Multiple sclerosis (MS) is an autoimmune deficiency disease whose pathogenesis has not been fully elucidated. This article focuses on the regulation of AKT/mTOR/STATs signaling pathways in various immune cells such as macrophage M1/M2 polarization, B cell proliferation and differentiation, helper T lymphocyte (Th cell) proliferation and differentiation, and Treg cell proliferation and differentiation, which would be helpful to illustrate the role of the AKT/mTOR/STATs signaling pathway in mediating the regulation of immune cells in MS.

Effect of macrophage polarization on interstitial fibrosis in mouse unilateral ureteral obstruction model / 中华肾脏病杂志

Objective To investigate the effect of macrophage polarization on tubulointerstitial fibrosis of mouse unilateral ureteral obstruction(UUO) model.Methods Twelve male C57BL/6J mice were employed,each of which with an age of 8 to 10 weeks.UUO model was established with these mice with the method of unilateral ureteral ligation.Mice were then sacrificed on the 7th and 14th day respectively after operation,and renal tissue specimens were obtained.The authors detected collagen deposition by Masson staining,and alpha smooth muscle actin (alpha SMA) as well as collagen type Ⅰ (Coll-1) mRNA by real-time quantitative PCR.The authors also detected the degree of renal interstitial macrophages infiltration and expression changes of polarization by immunofluorescence staining.Results Compared with the mice that were observed on the 7th day after operation,the degree of renal interstitial fibrosis in mice observed on the 14th day after operation was comparatively serious,the difference shown by semi-quantitative results was statistically significant (P ＜ 0.05).Moreover,mice observed on the 14th day after operation have more M2 macrophages,the difference between two groups of mice was statistically significant (P ＜ 0.05).On the contrary,there was no statistically significant difference in the degree of M1 macrophages infiltration between these two groups of mice.Conclusions In the renal interstitial fibrosis model induced by UUO,the degree of macrophage infiltration increased significantly,mainly resulted from M2 macrophage infiltration,suggesting that M2 macrophages were involved in the formation of renal fibrosis.