Li A-Guo, Huang Xiao-Ye, Zhang Ken-Qi, Xu Ping, Wang Hong-Yan, Yao Ye-Ping, Tu Yong-Sheng
The Second Clinical College, Guangzhou Medical University, Guangzhou, 511436, China.
School of Pediatrics, Guangzhou Medical University, Guangzhou, 511436, China.
Sci Rep. 2025 Jul 8;15(1):24574. doi: 10.1038/s41598-025-08990-4.
Brain-specific angiogenesis inhibitor-1 (BAI1) is an endocytic scavenger receptor that mediates macrophage clearance of apoptotic or phosphatidylserine-expressing cells. Previous studies have shown that BAI1 was localized in the cellular cytoplasm and membrane. However, currently there is no available information regarding the distribution of BAI1 expression in alveolar macrophages (AMs) or its specific role in acute lung injury (ALI). The aim of this study was to preliminarily investigate BAI1 expression in AMs and changes in BAI1 expression levels in an ALI model. A mouse model of ALI was established through intratracheal instillation of a 2 mg/kg LPS. The expression of BAI1 in lung tissues was quantified using immunohistochemistry staining, while the expression of BAI1 in AMs in bronchoalveolar lavage fluid (BALF) was examined through immunofluorescence. Additionally, the MH-S cells were treated with LPS to investigate the distribution and changes in BAI1 expression levels, which were detected using immunofluorescence and Western Blot. Results showed that BAI1 protein was found to be localized in the cellular nuclei in AMs. Moreover, the BAI1 expression level was observed to escalate with the rising concentration of LPS in MH-S cells and in AMs of lungs from ALI mice. Finally, the upregulation of BAI1 expression in MH-S cells induced by LPS was associated with a decrease in the efferocytosis of MH-S cells. The discovery of BAI1 expression in the nuclei of AMs in ALI mice is a novel finding. It is plausible that BAI1 protein may participate in efferocytosis of AMs during ALI through novel signaling pathways.
脑特异性血管生成抑制因子-1（BAI1）是一种内吞性清道夫受体，介导巨噬细胞清除凋亡细胞或表达磷脂酰丝氨酸的细胞。先前的研究表明，BAI1定位于细胞质和细胞膜。然而，目前尚无关于BAI1在肺泡巨噬细胞（AMs）中的表达分布或其在急性肺损伤（ALI）中的具体作用的可用信息。本研究的目的是初步探讨AMs中BAI1的表达以及ALI模型中BAI1表达水平的变化。通过气管内滴注2mg/kg脂多糖（LPS）建立ALI小鼠模型。采用免疫组织化学染色定量肺组织中BAI1的表达，通过免疫荧光检测支气管肺泡灌洗液（BALF）中AMs中BAI1的表达。此外，用LPS处理MH-S细胞，以研究BAI1表达水平的分布和变化，采用免疫荧光和蛋白质免疫印迹法进行检测。结果显示，在AMs的细胞核中发现了BAI1蛋白。此外，在MH-S细胞和ALI小鼠肺AMs中，观察到BAI1表达水平随LPS浓度升高而升高。最后，LPS诱导的MH-S细胞中BAI1表达上调与MH-S细胞的噬菌作用降低有关。在ALI小鼠AMs细胞核中发现BAI1表达是一项新发现。BAI1蛋白可能通过新的信号通路参与ALI期间AMs的噬菌作用，这是合理的。
