| Obstructive sleep apnea hypopnea syndrome(OSAHS)refers to intermittent hypoxia(CIH)/reoxygenation during sleep,with upper airway obstruction,causing apnea or hypoventilation,which impairs multiple organ function and brings greater harm for the patients' healthy and social economy.Many studies have found that exercise has a significant protective effect on multiple organ function damage,especially lung function,in patients with OSAHS,but the specific mechanism is unknown.Object:To investigate the effects of aerobic exercise on lung injury and endoplasmic reticulum stress in CIH mice.Methods:In this experiment,male 6-week-old C57BL/6 mice weighing 20-25 g,a total of 40 were used.The mice were randomly divided into 4 groups:control group(C),exercise control group(E),intermittent hypoxia group(H),intermittent hypoxia combined exercise group(HE),10 mice in each group.CIH modeling was performed using a self-designed computer-controlled chronic intermittent hypoxic device.Group C was normally raised for 5 weeks.In group E,the adaptive movement of the treadmill was performed for 1 week under normal-oxygen conditions.From the second week,treadmill exercise was performed for 60 minutes every day,and the adaptability and formal exercise were 5 weeks.Group H was treated with intermittent hypoxia for 8 hours every day for 5 weeks.In the first week,HE group was performed adaptive running exercise after CIH treatment.From the second week,8 hours of CIH treatment per day followed by treadmill exercise for 60 minutes,adaptability and formal exercise for 5 weeks.After the experiment,the morphology of lung tissue was observed byHematoxylin-Eosin staining,and the degree of fibrosis of lung tissue was observed by Masson staining.The mRNA expression of transforming growth factor(TGF?-1),type 1 collagen(Collagen I)and apoptosis-related gene CHOP were detected by RT-PCR.The phosphorylation of the regulatory protein eIF2a and the expression of ATF4 in endoplasmic reticulum stress were detected by Western Blot.Results:(1)Morphological examination in each group showed that CIH caused edema and structural disorder in the lung tissue of group H mice,and some alveolar cells merged into a larger balloon-containing cavity.There were a large amount of collagen fibers in the pulmonary interstitial and blood vessels ambitus,and the degree of fibrosis was severe in CIH mice.Aerobic exercise significantly improved alveolar destruction and fibrosis in HE group.(2)Compared with group C,the mRNA expression of lung fibrosis-related factor TGF-?1 in group H was significantly increased(P<0.01).The expression of TGF-?1 mRNA of HE group was significantly decreased compared with H group(P<0.05)because of aerobic exercise.Similarly,the mRNA expression of Collagen 1 in H group was significantly higher than that of group C(P<0.05).The mRNA expression of Collagen 1 in HE group was significantly lower than that in group H(P<0.05).(3)Compared with group C,the mRNA expression of endoplasmic reticulum stress-related gene CHOP in group H was significantly increased(P<0.05).Exercise significantly reduced the expression of CHOP in HE group compared with the H group(P<0.05).Compared with group C,the phosphorylation level of endoplasmic reticulum stress regulator eIF2a was significantly increased in group H(P<0.01)detected by Western Blot.And it in HE group was significantly lower than that in H group(P<0.05).Similarly,the protein expression of endoplasmic reticulum stress-related factor ATF4 in group H was significantly higher than that of group C(P<0.01).And it in HE group was significantly lower than that in H group(P<0.01)because of aerobic exercise..Conclusion:(1)Aerobic exercise has a protective effect on lung injury induced by CIH in mice.(2)Aerobic exercise reduces the degree of pulmonary fibrosis and apoptosis by mediating the endoplasmic reticulum stress process of lung tissue and protects lung function.In this process,eIF2a and ATF4 may play important regulatory roles. |
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