Zuo Yunlong, Dang Run, Peng Hongyan, Hu Peidan, Yang Yiyu
Pediatric Intensive Care Unit, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, No. 318, Renmin Middle Road, Yuexiu District, Guangzhou, Guangdong, 510120, China.
Open Life Sci. 2024 Aug 28;19(1):20220943. doi: 10.1515/biol-2022-0943. eCollection 2024.
Sepsis-induced acute lung injury is associated with lung epithelial cell injury. This study analyzed the role of the antimicrobial peptide LL37 with mitochondrial DNA (LL37-mtDNA) and its potential mechanism of action in lipopolysaccharide (LPS)-treated rat type II alveolar epithelial cells (RLE-6TN cells). RLE-6TN cells were treated with LPS alone or with LL37-mtDNA, followed by transcriptome sequencing. Differentially expressed and pivotal genes were screened using bioinformatics tools. The effects of LL37-mtDNA on cell viability, inflammation, apoptosis, reactive oxygen species (ROS) production, and autophagy-related hallmark expression were evaluated in LPS-treated RLE-6TN cells. Additionally, the effects of Hsp90aa1 silencing following LL37-mtDNA treatment were investigated in vitro. LL37-mtDNA further suppressed cell viability, augmented apoptosis, promoted the release of inflammatory cytokines, increased ROS production, and elevated LC3B expression in LPS-treated RLE-6TN cells. Using transcriptome sequencing and bioinformatics, ten candidate genes were identified, of which three core genes were verified to be upregulated in the LPS + LL37-mtDNA group. Additionally, Hsp90aa1 downregulation attenuated the effects of LL37-mtDNA on LPS-treated RLE-6TN cells. Hsp90aa1 silencing possibly acted as a crucial target to counteract the effects of LL37-mtDNA on viability, apoptosis, inflammation, and autophagy activation in LPS-treated RLE-6TN cells.
脓毒症诱导的急性肺损伤与肺上皮细胞损伤有关。本研究分析了抗菌肽LL37与线粒体DNA（LL37-mtDNA）的作用及其在脂多糖（LPS）处理的大鼠II型肺泡上皮细胞（RLE-6TN细胞）中的潜在作用机制。RLE-6TN细胞单独用LPS或LL37-mtDNA处理，然后进行转录组测序。使用生物信息学工具筛选差异表达基因和关键基因。在LPS处理的RLE-6TN细胞中评估LL37-mtDNA对细胞活力、炎症、细胞凋亡、活性氧（ROS）产生和自噬相关标志性表达的影响。此外，在体外研究了LL37-mtDNA处理后Hsp90aa1沉默的影响。LL37-mtDNA进一步抑制了LPS处理的RLE-6TN细胞的活力，增加了细胞凋亡，促进了炎性细胞因子的释放，增加了ROS的产生，并提高了LC3B的表达。通过转录组测序和生物信息学，鉴定出10个候选基因，其中3个核心基因在LPS + LL37-mtDNA组中被证实上调。此外，Hsp90aa1的下调减弱了LL37-mtDNA对LPS处理的RLE-6TN细胞的影响。Hsp90aa1沉默可能是对抗LL37-mtDNA对LPS处理的RLE-6TN细胞活力、细胞凋亡、炎症和自噬激活影响的关键靶点。
