Inhibition of METTL3 alleviated LPS-induced alveolar epithelial cell apoptosis and acute lung injury via restoring neprilysin expression.

Abstract

AIMS:

To investigate the role and mechanisms of methyltransferase-like 3 (METTL3) in the pathogenesis of lipopolysaccharide (LPS)-induced acute lung injury (ALI).

MAIN METHODS:

LPS intratracheally instillation was applied in alveolar epithelial cell METTL3 conditional knockout (METTL3-CKO) mice and their wild-type littermates. In addition, METTL3 inhibitor STM2457 was used. LPS treatment on mouse lung epithelial 12 (MLE-12) cell was applied to establish an in vitro model of LPS-induced ALI. H&E staining, lung wet-to-dry ratio, and total broncho-alveolar lavage fluid (BALF) concentrations were used to evaluate lung injury. Overall, the m6A level was determined with the m6A RNA Methylation Quantification Kit and dot blot assay. Expression of METTL3 and neprilysin were measured with immunohistochemistry, immunofluorescence, immunofluorescence-fluorescence in situ hybridization, and western blot. Apoptosis was detected with TUNEL, western blot, and flow cytometry. The interaction of METTL3 and neprilysin was determined with RIP-qPCR and MeRIP.

KEY FINDINGS:

METTL3 expression and apoptosis were increased in alveolar epithelial cells of mice treated with LPS, and METTL3-CKO or METTL3 inhibitor STM2457 could alleviate apoptosis and LPS-induced ALI. In MLE-12 cells, LPS-Induced METTL3 expression and apoptosis. Knockdown of METTL3 alleviated, while overexpression of METTL3 exacerbated LPS-induced apoptosis. LPS treatment reduced neprilysin expression, the intervention of neprilysin expression negatively regulated apoptosis without affecting METTL3 expression, and mitigated the promoting effect of METTL3 on LPS-induced apoptosis. Additionally, METTL3 could bind to the mRNA of neprilysin, and reduce its expression.

SIGNIFICANCE:

Our findings revealed that inhibition of METTL3 could exert anti-apoptosis and ALI-protective effects via restoring neprilysin expression.

• Authors: Jingsi Jia, Yu Yuan, Yi He, Binaya Wasti, Wentao Duan, Zhifeng Chen, Danhong Li, Wenjin Sun, Qingping Zeng, Libing Ma, Xiufeng Zhang, Shaokun Liu, Dongshan Zhang, Linxia Liu, Qimi Liu, Hengxing Liang, Guyi Wang, Xudong Xiang, Bing Xiao
• Journal: Life sciences (Life Sci) Vol. 333 Pg. 122148 (Nov 15 2023) ISSN: 1879-0631 [Electronic] Netherlands
• PMID: 37805166 (Publication Type: Journal Article)
• Copyright: Copyright © 2023. Published by Elsevier Inc.

Chemical References

• Lipopolysaccharides
• Neprilysin
• Mettl3 protein, mouse

Topics

• Animals
• Mice
• Acute Lung Injury (metabolism)
• Alveolar Epithelial Cells (metabolism)
• Apoptosis
• In Situ Hybridization, Fluorescence
• Lipopolysaccharides (pharmacology)
• Lung (metabolism)
• Neprilysin