Maresin-2 alleviates allergic airway inflammation in mice by inhibiting the activation of NLRP3 inflammasome, Th2 type immune response and oxidative stress.

Asthma is a chronic inflammatory disease of the respiratory system. Maresin-2 (MaR2) is biosynthesized from docosahexaenoic acid (DHA) by macrophages, display strong anti-inflammatory and pro-resolving activity. To investigate the therapeutic effect and mechanism of MaR2 on asthmatic mice induced by ovalbumin (OVA) in conjunction with the adjuvant aluminum hydroxide. Twenty four female BALB/c mice were randomly divided into control, OVA, OVA + MaR2, and OVA + dexamethasone (Dexa) groups. MaR2 or Dexa were given as a treatment for OVA-induced asthma. Serum, bronchoalveolar alveolar lavage fluid (BALF) and lung tissue were collected for further analysis. The Pathological changes of lung tissue, proportion of inflammatory cells in BALF, levels of inflammatory cytokines in BALF or serum, oxidative stress indices, and the protein concentration of ASC, MPO, Ly-6G, ICAM-1, NLRP3 and Caspase-1 in lung tissues were evaluated. Compared with the OVA group, both OVA + MaR2 and OVA + Dexa group had reduced inflammation and mucus secretion in lung tissue, number of inflammatory cells in BALF, levels of related inflammatory cytokines in serum or BALF, and expressions of ASC, MPO, Ly-6G, ICAM-1, NLRP3 and Caspase-1 proteins in lung tissue. In addition, the oxidative stress was alleviated as indicated by decreased MDA, and elevated SOD and GSH. MaR2 has an obvious protective effect on OVA-induced bronchial asthma in mice, in a similar manner as Dexa. The mechanism may be related to the inhibition of the Th2 type immune response, the NLRP3 inflammasome activation and oxidative stress.

The effect of FTY720 at different doses and time-points on LPS-induced acute lung injury in rats.

We sought to assess the protective effect of different doses of Fingolimod (FTY720) in a rat model of acute lung injury (ALI) induced by intratracheal instillation of lipopolysaccharide (LPS) and explored the underlying mechanisms. The ALI model was established in rats and different doses of FTY720 (0.1 mg/kg, 0.2 mg/kg, 0.5 mg/kg, 1 mg/kg, or 2 mg/kg) were injected intraperitoneally. Lung computed tomography and blood gas analyses were performed at 6 h, 24 h, and 48 h after intraperitoneal injection, and the lung tissues were extracted to prepare paraffin sections for histopathological examination. The levels of inflammatory cytokines (TNF-α, IL-6, and IL-1ß) were detected by ELISA, and the expressions of inflammatory pathway proteins in each group were measured by Western blot analysis. A single intraperitoneal injection of FTY720 inhibited LPS-induced NF-κB activation, reduced the level of inflammatory cytokines, and decreased the infiltration of inflammatory cells. Moreover, it alleviated lung tissue injury, as shown by marked attenuation of pulmonary oedema and improved arterial partial pressure of oxygen (PaO2) and the general condition of ALI rats. In conclusion, our results demonstrate the protective effect of FTY720 against LPS-induced ALI. The underlying mechanism of the protective effect may involve inhibition of LPS-induced activation of NF-κB and regulation of the inflammatory pathway to alleviate barrier dysfunction of alveolar capillaries.