Involvement of Gr-1 dull+ cells in the production of TNF-α and IL-17 and exacerbated systemic inflammatory response caused by lipopolysaccharide

Characterization and Hepatoprotections of Ganoderma lucidum Polysaccharides against Multiple Organ Dysfunction Syndrome in Mice

Background

The liver is one of the most commonly affected organs in multiple organ dysfunction syndrome (MODS). In recent years, there have been many studies on Ganoderma lucidum polysaccharides (GLP), but the role of GLP in MODS is still unclear. The purpose of this work was to explore the antioxidant, anti-inflammatory, and protective effects of GLP on the liver in MODS model mice.

Methods

The characteristic properties of GLP were processed by physicochemical analysis. The MODS models were successfully established with intraperitoneal injection of zymosan in Kunming strain mice. The antioxidant, anti-inflammatory, and hepatoprotective effects of GLP were processed both in vitro and in vivo by evaluating the oxidative parameters, inflammatory factors, and liver pathological observations.

Results

The characterization analysis revealed that GLP was a pyranose mainly composed of glucose with the molecular weights (Mw) of 8309 Da. The experimental results proved that GLP had potential hepatoprotection possibly by improving the antioxidant status (scavenging excessive oxygen radicals, increasing the antioxidant enzyme activities, and reducing the lipid peroxide), alleviating the inflammatory response (reducing the inflammatory factor levels), and guaranteeing the liver functions.

Conclusions

This research suggested that GLP had the potential to be developed as a natural medicine for the treatment of multiple organ failure.

Effect of lipopolysaccharide and polyinosinic:polycytidylic acid in a murine model of nasal polyp

Several factors, including bacterial and viral infections, have been associated with rhinosinusitis and nasal tissue remodelling that may result in nasal polyp formation. However, the potential role of bacterial or viral stimuli triggering polyp development is unclear. Here, we used lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid [poly(I:C)] in a murine model of allergic rhinosinusitis to compare different effects of bacterial- and virus-derived stimuli in the pathogenesis of nasal polyp formation. Briefly, BALB/c mice were sensitised and challenged with ovalbumin and staphylococcal enterotoxin, with or without LPS or poly(I:C), and the consequent histopathological profiles, cytokines, and systemic humoral responses were studied. While no significant differences in polyp formations and epithelial disruptions were observed among the experimental groups, the local cell recruitment patterns slightly differed in animals that received either LPS or poly(I:C). Additionally, the local immune environments generated by LPS or poly(I:C) stimulation varied. LPS stimulation induced a marked Th1/Th17 response and predominantly neutrophilic nasal polyp formations, whereas poly(I:C) induced a Th2-skewed environment in neutrophilic nasal polyp development. Overall, our findings show that both cell recruitment patterns and local immune environments induced by these two stimuli differ, which may have implications in the physiopathology of rhinosinusitis with nasal polyp.

Establishment of a mouse model of lipopolysaccharide-induced neutrophilic nasal polyps

Research has identified that gram-negative bacteria have an important role in refractory nasal polyps. In the present study, lipopolysaccharide (LPS) was used to establish a mouse model with neutrophilic nasal polyps in order to explore the effect and mechanism of LPS on the formation of neutrophilic nasal polyps in mice. A total of 5 or 10 µg of LPS was dropped into the nasal cavities of C57BL/6J mice in order to establish animal models with neutrophilic nasal polyps. Histological staining, toll-like receptor 4 (TLR4), cluster of differentiation 68 for macrophages and myeloperoxidase for neutrophil immunohistochemistry were used to observe histopathological changes in the nasal mucosa. The expression levels of cytokines, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-4 and IL-17 in the nasal lavage fluid, were detected by ELISA. Compared with the control group, mice in the LPS groups exhibited significant mucosa epithelial cell damage and nasal polyp formation. Furthermore, TLR4⁺ cells, macrophages, neutrophils and significantly increased levels of IFN-γ, TNF-α, and IL-17 in the nasal lavage fluids were indicated (all P=0.008). These findings indicated that LPS is able to activate the TLR4 receptor pathway to induce the formation of neutrophilic nasal polyps in mice. Additionally, LPS administration was accompanied by a significant increase in the number of macrophages, T helper (Th) 1 and Th17-related cytokines (P=0.009, P=0.008 and P=0.008, respectively). Therefore, the present model is commensurate with the characteristics of primary nasal polyps that have been identified in the Asian population.