CXCL4与高氧诱导新生小鼠性别差异性肺损伤的相关研究

Correlation of CXCL4 and lung injury with sexual dimorphism in neonatal mice induced by hyperoxic

目的:探讨肺组织CXC趋化因子配体4(chemokine C-X-C motif ligand 4,CXCL4)与高氧诱导新生小鼠性别差异性肺损伤的关系及相关机制。方法:32只C57BL/6J新生小鼠(雄性、雌性各16只)随机分为4组:高氧雄性组、高氧雌性组、空气雄性组、空气雌性组(每组8只)。高氧组小鼠置于95%氧浓度下暴露7 d,空气组于室内环境(FiO2=21%)中饲养。串联质谱标签(tandem mass tags,TMT)定量蛋白组学技术检测4组小鼠肺组织中蛋白质的表达变化,筛选差异表达的蛋白质;ELISA法检测肺组织匀浆CXCL4含量;HE染色法观察小鼠肺组织病理改变;冰冻切片免疫荧光染色检测肺组织'M4'型巨噬细胞(MMP7+ S100A8+)分布情况。结果:高氧暴露组肺组织肺泡化程度降低,辐射状肺泡计数(radial alveolar count,RAC)明显减小(P <0.001);与高氧雌性组相比,高氧雄性组RAC值下降(P <0.01)。TMT筛选出的CXCL4在高氧雄性组差异性表达上调;肺组织匀浆验证了质谱分析结果。高氧雄性小鼠肺组织MMP7+ S100A8+细胞增多。结论:高氧诱导新生小鼠肺损伤程度存在性别差异,雄性损伤程度高于雌性,可能与CXCL4诱导肺'M4'型巨噬细胞形成存在一定的相关性。

Objective:This study aims to investigate the relationship between chemokine C-X-C motif ligand 4(CXCL4)and gender differences in lung tissues of neonatal mice with hyperoxia-induced lung injury.Methods:Thirty-two mouse pups(16 animals per sex),were randomly and equally assigned to four groups:Hyperoxia-male group,Hyperoxia-female group,Room air-male group and Room air-female group,with 8 mice in each group.The mice in air group were exposed to room air(FiO2=21%)and those in hyperoxia group were exposed to hyperoxia(FiO2≥95%)for 7 days.All animals were sacrificed and lung tissues were excised for analysis via histological staining,tandem mass tags(TMT)technology and immunofluorescence staining.The levels of CXCL4 in tissue homogenates were measured.Results:The mouse pups exposed to hyperoxia had significant reductions in the degree of alveolarization,and radial alveolar count(RAC)in lung tissues(P<0.001)was significantly decreased in hyperoxia-exposed animals and was decreased to a larger extent in males compared with females(P<0.01).Under hyperoxia intervention,CXCL4 upregulated was exclusively differentially regulated in hyperoxia exposed neonatal male mice compared to room air controls.M4 macrophage(MMP7+S100A8+)infiltration was higher in male mice following postnatal hyperoxia exposure.Conclusion:These findings highlight sex-specific differences in hyperoxic lung injury,and male neonatal mice are more susceptible to hyperoxia-mediated lung injury and display larger arrest in lung alveolarization,which suggests the changes in M4 macrophages induced by CXCL4 may play a crucial role in sexual differences in neonatal hyperoxic lung injury.