Objective:To evaluate the relationship between Wnt/β-catenin signaling pathway and autophagy during hyperoxia-induced acute lung injury in infantile rats.Methods:A total of 24 clean-stage healthy male infantile Sprague-Dawley rats, aged 14 days, weighing 40-50 g, were allocated into 4 groups ( n=6 each) using a random number table method: control group (C group), hyperoxic acute lung injury (HALI) group, HALI+ IWP-2 group (HI group) and HALI+ DMF group (HD group). HALI model was developed by inhaling oxygen at a concentration greater than 90% for 72 h. Starting from 30 min before developing the model, IWP-2 15 mg/kg was intraperitoneally injected every day for 3 consecutive days in HI group, the equal volume of DMF solution was injected every day for 3 consecutive days in HD group, and the equal volume of normal saline was intraperitoneally injected instead in C and HALI groups. Blood samples were taken from the common carotid artery for blood gas analysis at the end of developing the model, and oxygenation index (OI) was calculated. Then the infantile rats were sacrificed under deep anesthesia, and lungs were removed for examination of the pathological changes which were scored and for determination of the weight to dry weight ratio (W/D ratio), contents of interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-alpha (TNF-α) (by enzyme-linked immunosorbent assay) and expression of Wnt3a, β-catenin, microtubule-associated protein 1 light chain 3(LC3), Beclin1 and p62 (by Western blot). LC3Ⅱ/LC3Ⅰ ratio was calculated. Results:Compared with C group, the OI was significantly decreased, the W/D ratio, lung injury score and contents of IL-6, IL-1β and TNF-α were increased, and the expression of Wnt3a, β-catenin and Beclin1 was up-regulated, the expression of p62 was down-regulated, and LC3Ⅱ/LC3Ⅰ ratio was increased in HALI, HD and HI groups ( P<0.05). Compared with HALI group, the OI was significantly decreased, the W/D ratio, lung injury score and contents of IL-6, IL-1β and TNF-α were increased, and the expression of Wnt3a, β-catenin and p62 was down-regulated, the expression of Beclin1 was up-regulated, and LC3Ⅱ/LC3Ⅰ ratio was increased in HI group ( P<0.05), and no significant change was found in the parameters mentioned above in HD group ( P>0.05). Compared with HI group, the OI was significantly increased, the W/D ratio, lung injury score and contents of IL-6, IL-1β and TNF-α were decreased, and the expression of Wnt3a, β-catenin and p62 was up-regulated, the expression of Beclin1 was down-regulated, and LC3Ⅱ/LC3Ⅰ ratio was decreased in HD group ( P<0.05). Conclusions:In the pathophysiology of hyperoxia-induced acute lung injury in infantile rats, Wnt/β-catenin signaling pathway may be a negative regulator of autophagy. Wnt/β-catenin signaling pathway may be involved in the process of HALI through negative regulation of autophagy.

Objective:To evaluate the effects of electroacupuncture (EA) on the learning and memory function of offspring rats exposed to sevoflurane in late-pregnancy.Methods:Thirty-two SPF healthy Sprague-Dawley pregnant rats at gestational day 18, weighing 260-280 g, were assigned to 4 groups ( n=8 each) using a random number table method: control group (C group), sevoflurane group (Sev group), EA group and sham EA group (SEA group). Sev, SEA and EA groups inhaled 2.5% sevoflurane in 50% oxygen for 6 h. In EA group, Shenting, Baihui, bilateral Quchi, and bilateral Zusanli points were stimulated with an electric stimulator (disperse-dense waves, frequency 2/6 Hz, intensity 1 mA, 20 min per day for 7 consecutive days) starting on postnatal day 21, EA was performed again for 7 days after an interval of 1 day, and the EA treatment lasted for a total of 14 days. Moriss water maze test was performed at 36 days of age to detect the spatial learning and memory function. The offspring rats were sacrificed on postnatal day 42, and the hippocampal tissues were removed for calculation of the dendritic spine density of neurons (after Golgi staining) and for determination of the apoptosis rate (using flow cytometry) and the expression of the two primary forms of brain-derived neurotrophic factor (BDNF), mature (mBDNF) and pro (proBDNF), mBDNF/proBDNF ratio, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) (by Western blot). The mBDNF/proBDNF ratio was calculated. Results:Compared with C group, the escape latency was significantly prolonged, the time of staying at the target platform quadrant was shortened, the frequency of crossing the original platform was reduced, the dendritic spine density of hippocampal neurons and mBDNF/proBDNF ratio were decreased, the expression of TrkB was down-regulated, and the expression of p75NTR was up-regulated in Sev groups ( P<0.05). Compared with the offspring rats of Sev and SEA groups, the escape latency was significantly shortened, the time of staying at the target platform quadrant was prolonged, the frequency of crossing the original platform was increased, the dendritic spine density of hippocampal neurons and mBDNF/proBDNF ratio were increased, the expression of TrkB was up-regulated, and the expression of p75NTR was down-regulated in the offspring rats of EA group ( P<0.05), and no significant change was found in the aforementioned parameters in the offspring rats of SEA group ( P>0.05). There was no significant difference in the apoptosis rate of hippocampal neurons among the offspring rats of the four groups ( P>0.05). Conclusions:EA can improve the learning and memory function of offspring rats exposed to sevoflurane in late-pregnancy, and the mechanism may be related to promoting the conversion of proBDNF to mBDNF and improving neuronal development.