Key Laboratory of Geriatrics of Jiangsu Province, Department of Geriatrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, P.R. China.
Department of Respiratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan, P.R. China.
Cancer Genomics Proteomics. 2021 May-Jun;18(3 Suppl):451-459. doi: 10.21873/cgp.20271.
BACKGROUND/AIM: The prevalence of idiopathic pulmonary fibrosis (IPF) increases with age and is associated with senescence of alveolar epithelial cells (AECs). AEC senescence in pulmonary cells mediates IPF. We herein aimed to determine if YAP1 gene knockdown, a member of the Hippo/YAP signal pathway, in the bleomycin (BLM)-induced mouse model of IPF, inhibits onset of senescence of AECs and alleviates IPF.
Adeno-associated viruses (AAVs) expressing Yes-associated protein 1 (YAP1) short hairpin RNA (shRNA) were delivered into the lung of BLM-induced IPF mice via intratracheal injection, to knockdown the YAP1 gene in AECs. The mice were assigned to 4 groups: G1: control (normal mice); G2: IPF mice; G3: IPF + AAV/YAP1; G4: IPF + AAV/scramble. After 28 days, AECs were examined for senescence using H&E staining, Masson's trichrome Staining, senescence-associated ß-galactosidase (SA-β-gal) staining, western blotting and co-immunofluorescence staining, to determine the expression of YAP1, Smad-3 and p21, in order to determine the induction of senescence of ACEs.
The severity of IPF determined by H&E staining, Masson's staining and immunofluorescence (IF) staining was positively correlated with the senescence of AECs. Down-regulation of YAP1 expression of the Hippo-signaling pathway, determined by western blotting in AECs, alleviated pulmonary fibrosis as determined by Masson's staining. Down regulation of YAP1 expression reduced the senescence of AECs as determined by ß-galactosidase (SA-β-gal) staining, which alleviated the clinical symptoms of IPF mice, as determined by body weight and lung index.
Down-regulation of YAP1 expression in AECs inhibited AEC senescence which is thought to be the cause of IPF. Therefore, future studies can focus on inhibiting YAP1 to effectively treat IPF.
背景/目的：特发性肺纤维化（IPF）的患病率随年龄增长而增加，与肺泡上皮细胞（AEC）衰老有关。肺细胞中的 AEC 衰老介导了 IPF。本研究旨在确定 YAP1 基因敲低（Hippo/YAP 信号通路的一个成员）是否能抑制博来霉素（BLM）诱导的 IPF 小鼠模型中 AEC 衰老的发生，从而缓解 IPF。
通过气管内注射将表达 Yes 相关蛋白 1（YAP1）短发夹 RNA（shRNA）的腺相关病毒（AAVs）递送至 BLM 诱导的 IPF 小鼠的肺部，以敲低 AEC 中的 YAP1 基因。将小鼠分为 4 组：G1：对照组（正常小鼠）；G2：IPF 组；G3：IPF+AAV/YAP1 组；G4：IPF+AAV/scramble 组。28 天后，通过 H&E 染色、Masson 三色染色、衰老相关β-半乳糖苷酶（SA-β-gal）染色、Western blot 和共免疫荧光染色检测 AEC 衰老，以确定 ACE 衰老的诱导情况。
H&E 染色、Masson 染色和免疫荧光（IF）染色确定的 IPF 严重程度与 AEC 衰老呈正相关。Western blot 检测到 AEC 中 Hippo 信号通路的 YAP1 表达下调，通过 Masson 染色缓解了肺纤维化。下调 YAP1 表达通过β-半乳糖苷酶（SA-β-gal）染色减少了 AEC 的衰老，从而缓解了 IPF 小鼠的临床症状，通过体重和肺指数来确定。
下调 AEC 中的 YAP1 表达抑制了被认为是 IPF 病因的 AEC 衰老。因此，未来的研究可以集中在抑制 YAP1 以有效治疗 IPF。
