缺氧通过TAZ-H2A.Z轴调控H2A.Z染色质沉积促进肺泡上皮细胞增殖的研究  

Hypoxia promotes proliferation of alveolar epithelial cells by regulating chromatin H2A.Z deposition through TAZ-H2A.Z axis

作　　者：刘派予 张梦洁 曾继涛 倪兵 LIU Paiyu;ZHANG Mengjie;ZENG Jitao;NI Bing(Department of Pathophysiology,Faculty of High Altitude Military Medicine,Army Medical University(Third Military Medical University),Chongqing;Department of Psychiatry and Psychology,No.991 Hospital of Joint Logistic Support Force of PLA,Xiangyang,Hubei;Reproductive Medical Center,First Affiliated Hospital,Army Medical University(Third Military Medical University),Chongqing,China)

机构地区：[1]陆军军医大学(第三军医大学)高原军事医学系病理生理学教研室,重庆 [2]中国人民解放军联勤保障部队第991医院精神心理科,湖北襄阳 [3]陆军军医大学(第三军医大学)第一附属医院生殖医学中心,重庆

出　　处：《陆军军医大学学报》2025年第6期498-505,共8页Journal of Army Medical University

基　　金：重庆市自然科学基金面上项目(CSTB2024NSCQ-MSX0838)。

摘　　要：目的本研究旨在探讨转录共激活因子(transcriptional coactivator with PDZ-binding motif,TAZ)与组蛋白H2A(histone H2A,H2A)的一种组蛋白变体H2A.Z,在缺氧诱导的肺损伤后修复中的作用及其潜在机制。方法利用缺氧模拟仓(5800 m)处理4 d后,构建小鼠缺氧肺损伤模型,肺组织切片HE染色评估肺损伤程度。利用缺氧工作站(1%O_2浓度)处理小鼠肺泡上皮细胞系(murine lung epithelial-12,MLE12)24 h,构建MLE12缺氧细胞模型,Western blot分析检测TAZ表达。CCK-8实验评价肺泡上皮细胞(alveolar epithelial cells,AECs)增殖。免疫共沉淀(co-immunoprecipitation,Co-IP)实验验证TAZ与H2A.Z二者之间的相互作用。靶向剪切及转座酶标记技术(cleavage under targets and tagmentation,CUT&Tag)测序分析TAZ影响H2A.Z在染色质沉积情况。结果缺氧显著诱导小鼠肺组织肺泡萎缩及炎症浸润(P<0.01)。缺氧培养显著上调MLE12细胞中TAZ蛋白表达(P<0.05)。CCK-8实验发现,敲低TAZ后AECs增殖能力显著下降(P<0.01)。Co-IP证实TAZ与H2A.Z存在物理相互作用。靶向剪切及转座酶标记技术(cleavage under targets and tagmentation,CUT&Tag)测序显示缺氧促进H2A.Z在染色质上的沉积(常氧结合位点31817,缺氧结合位点44078),而TAZ敲低部分逆转此现象(结合位点37840)。结论缺氧显著上调TAZ表达,后者与H2A.Z的结合并促进H2A.Z在染色质上的沉积,增强AECs增殖以应对缺氧损伤。Objective To explore the role and underlying mechanism of the transcriptional coactivator with PDZ-binding motif(TAZ)and a histone variant of acute histone H2A(H2A.Z)in the repair of hypoxia-induced lung injury.Methods A mouse model of hypoxic lung injury was established by being placed in a hypoxia chamber(simulating an altitude of 5800 m)for 4 d.HE staining was used to observe the severity of lung injury.A hypoxia model of murine alveolar epithelial cells(murine lung epithelial-12,MLE12)was constructed by treating the cells in a hypoxia workstation(1%O2 concentration)for 24 h.Western blotting was employed to detect TAZ expression.The proliferation of alveolar epithelial cells(AECs)was evaluated by CCK-8 assay.Co-immunoprecipitation(Co-IP)assay was utilized to verify the interaction between TAZ and H2A.Z.CUT&Tag sequencing was performed to determine the effect of TAZ on the chromatin deposition of H2A.Z.Results Hypoxia significantly induced alveolar atrophy and inflammatory infiltration in mouse lung tissues(P<0.01).Hypoxia significantly up-regulated the protein level of TAZ in MLE12 cells(P<0.05).CCK-8 assay showed that knockdown of TAZ significantly reduced the proliferative capacity of AECs(P<0.01).Co-IP assay confirmed the physical interaction between TAZ and H2A.Z.CUT&Tag sequencing revealed that hypoxia promoted the deposition of H2A.Z on chromatin(31817 peaks under normoxia,44078 peaks under hypoxia),which was partially reversed by TAZ knockdown(37840 peaks).Conclusion Hypoxia significantly up-regulates the expression of TAZ,which combines with H2A.Z and promotes the deposition of H2A.Z on chromatin,thus enhancing the proliferation of AECs in response to hypoxic injury.

关 键 词：缺氧 肺泡上皮细胞 TAZ H2A.Z 增殖 

分 类 号：R322.35[医药卫生—人体解剖和组织胚胎学] R363.125[医药卫生—基础医学] R364.3