Alveolar type II (ATII) epithelial cells contain lamellar bodies (LBs) which synthesize and store lung surfactants. In animals, the inhibition or knockout of leucine-rich repeat kinase 2 (LRRK2) causes abnormal enlargement of LBs in ATII cells. This effect of LRRK2 inhibition in lung is largely accepted as being mediated directly through blocking of the kinase function; however, downstream consequences in the lung remain unknown. In this work we established an in vitro alveolar epithelial cell (AEC) model that recapitulates the in vivo phenotype of ATII cells and developed an assay to quantify changes in LB size in response to LRRK2 inhibitors. Culture of primary human AECs at the air-liquid interface on matrigel and collagen-coated transwell inserts in the presence of growth factors promoted the LB formation and apical microvilli and induced expression of LRRK2 and ATII cell markers. Treatment with a selective LRRK2 inhibitor resulted in pharmacological reduction of phospho-LRRK2 and a significant increase in LB size; effects previously reported in lungs of non-human primates treated with LRRK2 inhibitor. In summary, our human in vitro AEC model recapitulates the abnormal lung findings observed in LRRK2-perturbed animals and holds the potential for expanding current understanding of LRRK2 function in the lung.

肺泡 II 型 (ATII) 上皮细胞包含合成和储存肺表面活性剂的层状体 (LB)。在动物中，富含亮氨酸重复激酶 2 (LRRK2) 的抑制或敲除会导致 ATII 细胞中 LB 的异常增大。肺中 LRRK2 抑制的这种作用在很大程度上被认为是通过阻断激酶功能直接介导的。然而，肺部的下游后果仍然未知。在这项工作中，我们建立了一个体外肺泡上皮细胞 (AEC) 模型，该模型概括了体内ATII 细胞的表型并开发了一种测定方法来量化响应 LRRK2 抑制剂的 LB 大小的变化。在生长因子存在的情况下，在基质胶和胶原包被的 transwell 插入物上的气液界面处培养原代人 AEC，促进了 LB 形成和顶端微绒毛，并诱导了 LRRK2 和 ATII 细胞标记物的表达。用选择性 LRRK2 抑制剂治疗导致磷酸化 LRRK2 的药理学减少和 LB 大小的显着增加；先前在用 LRRK2 抑制剂治疗的非人类灵长类动物的肺中报告的影响。总之，我们的人类体外AEC 模型概括了在 LRRK2 扰动的动物中观察到的异常肺部发现，并有可能扩大目前对 LRRK2 肺功能的理解。