IDH1/MDH1 deacetylation promotes NETosis by regulating OPA1 and autophagy

Background: As a heterogeneous and life-threatening disease, the pathogenesis of acute liver failure (ALF) is complex. Our previous study has shown that IDH1/MDH1 deacetylation promotes ALF by regulating NETosis (a novel mode of cell death). In this article, we explore the manners of IDH1/MDH1 deacetylation regulates NETosis.

Methods: In vitro experiments, the formation of NETs was detected by immunofluorescence staining and Western blotting. LC3 fluorescence staining was used to detect autophagosome formation. To observe mitochondrial morphology, cells were stained by Mito-Tracker Red. Western blotting was used to detect the levels of Autophagy protein and mitochondrial Dynamin. In vivo experiments, the ALF model in mouse was established with LPS/D-gal, and the formation of NETs was detected by immunofluorescence staining and Western blotting. The Autophagy levels were detected by Western blotting in liver samples.

Results: In dHL-60 cells, Western blotting results showed that the expression of OPA1 was higher in the IDH1/MDH1 deacetylated group compared with the IDH1/MDH1 WT group. And histone deacetylase inhibitor 6 (HDAC6i, ACY1215) decreased the expression level of OPA1 in IDH1/MDH1 deacetylated group. IDH1/MDH1 deacetylation increased the expression levels of both LC3B-II and Beclin 1, while decreasing the expression level of p62. It was reversed by ACY1215. Combined with our previous experiments, IDH1/MDH1 deacetylation upregulated Autophagy concomitant with the increased expression of the markers of NETs formation. In a mouse model of ALF, ACY1215 further decreased the expression levels of LC3B-II and Beclin 1, while increasing the expression level of p62 in IDH1/MDH1 deacetylated mice.

Conclusions: IDH1/MDH1 deacetylation promoted NETosis by regulating Autophagy and OPA1 in vitro. The regulation of neutrophil Autophagy on NETosis during IDH1/MDH1 deacetylation might be masked in mice. ACY1215 might attenuate NETosis by regulating neutrophil Autophagy, which alleviated ALF aggravated by IDH1/MDH1 deacetylation.

Autophagy; Deacetylation; NETosis; OPA1.