ABSTRACT
Objective:To evaluate the role of α7 nicotinic acetylcholine receptor (α7nAChR) in penehyclidine hydrochloride-induced reduction of endotoxin-induced acute lung injury (ALI) in mice.Methods:Forty SPF healthy male C57BL/6 mice, aged 6-8 weeks, weighing 18-25 g, were divided into 4 groups ( n=10 each) using a random number table method: control group (group C), ALI group, penehyclidine hydrochloride group (PHC group), and α7nAChR inhibitor MLA group (MLA group). ALI was induced by intraperitoneal injection of lipopolysaccharide 15 mg/kg in anesthetized animals, while normal saline was given instead in group C. In PHC group, penehyclidine hydrochloride 2 mg/kg was intraperitoneally injected at 30 min before developing the model. MLA 10 mg/kg was intraperitoneally injected at 10 min before administration of penehyclidine hydrochloride in MLA group. Mice were sacrificed at 6 h after lipopolysaccharide administration, and lung tissues were collected for microscopic examination of the pathological changes (by HE staining) and for determination of the wet/dry weight ratio (W/D ratio), content of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and IL-10 (by enzyme-linked immunosorbent assay) and expression of α7nAChR (by Western blot). Results:Compared with C group, the W/D ratio and contents of TNF-α and IL-1β were significantly increased, the content of IL-10 was decreased, and the expression of α7nAChR was up-regulated in ALI, PHC and MLA groups ( P<0.05). Compared with ALI group, the W/D ratio and contents of TNF-α and IL-1β were significantly decreased, the content of IL-10 was increased, and the expression of α7nAChR was up-regulated in PHC group ( P<0.05). Compared with PHC group, the W/D ratio and contents of TNF-α and IL-1β were significantly increased, the content of IL-10 was decreased, and the expression of α7nAChR was down-regulated in MLA group ( P<0.05). Compared with ALI group, the pathological changes of lung tissues were significantly mitigated in PHC group, while this effect of PHC was partially reversed by α7nAChR inhibitor MLA. Conclusions:α7nAChR is involved in penehyclidine hydrochloride-induced reduction of endotoxin-induced ALI in mice.
ABSTRACT
Objective:To evaluate the role of microRNA-21 (miR-21) in sepsis-induced lung injury and the relationship with transient receptor potential melastatin 2 (TRPM2) expression in rats.Methods:Forty-eight clean-grade Wistar rats, half male and half female, weighing 250-300 g, were divided into 4 groups ( n=12 each) by a random number table method: sham operation group (SH group), sepsis group (S group), miR-21 inhibitor group (group MI), and miR-21 inhibitor plus TRPM2 blocker Gd3 + group.Sepsis was induced by cecal ligation and puncture (CLP) in anesthetized rats.In MI group and MIG group, miR-21 inhibitor and miR-21 inhibitor plus TRPM2 blocker Gd3 + were injected through the tail vein, respectively, at 12 h before CLP.Carotid artery blood samples were collected at 24 h after CLP for blood gas analysis, PaO 2 was recorded, and oxygenation index was calculated.Animals were sacrificed, and lung tissues were removed for microscopic examination of the pathological changes which were scored and for determination of wet to dry weight ratio (W/D ratio), expression of miR-21 and TRPM2 mRNA (quantitative real-time polymerase chain reaction), levels of malondialdehyde (MDA) and superoxide dismutase (SOD) (by spectrophotometer colorimetry) and levels of interleukin-6 (IL-6), IL-8 and tumor necrosis factor-alpha (TNF-α) in serum (by enzyme-linked immunosorbent assay). Results:Compared with group SH, the oxygenation index and SOD activity were significantly decreased, and W/D ratio, lung injury score, MDA content, serum IL-6, IL-8 and TNF-α concentrations were increased in the other three groups, and the expression of miR-21 mRNA was up-regulated, and the expression of TRPM2 mRNA was down-regulated in group S ( P<0.05). Compared with group S, the oxygenation index, SOD activity and serum IL-6, IL-8 and TNF-α concentrations were significantly increased, and W/D ratio, lung injury score and MDA content were decreased in group MI, and the expression of miR-21 mRNA was down-regulated, and the expression of TRPM2 mRNA was up-regulated in MI and MIG groups ( P<0.05). Compared with group MI, the oxygenation index and SOD activity were significantly decreased, W/D ratio, lung injury score, MDA content, serum IL-6, IL-8 and TNF-α concentrations were increased, and the expression of TRPM2 mRNA was down-regulated in group MIG ( P<0.05). Conclusion:Up-regulated expression of miR-21 and down-regulated expression of TRPM2 are involved in the process of sepsis-induced lung injury in rats.