FC-99 ameliorates sepsis-induced liver dysfunction by modulating monocyte/macrophage differentiation via Let-7a related monocytes apoptosis

Yarong Zhao; Haiyan Zhu; Haining Wang; Liang Ding; Lizhi Xu; Dai Chen; Sunan Shen; Yayi Hou; Huan Dou

doi:10.18632/oncotarget.24127

FC-99 ameliorates sepsis-induced liver dysfunction by modulating monocyte/macrophage differentiation via Let-7a related monocytes apoptosis

Oncotarget. 2018 Jan 10;9(19):14959-14976. doi: 10.18632/oncotarget.24127. eCollection 2018 Mar 13.

Authors

Yarong Zhao¹, Haiyan Zhu¹, Haining Wang¹, Liang Ding¹, Lizhi Xu², Dai Chen³, Sunan Shen^{1

2}, Yayi Hou^{1

2}, Huan Dou^{1

2}

Affiliations

¹ The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, PR China.
² Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, PR China.
³ Novel Bioinformatics Co., Ltd, Shanghai, PR China.

Abstract

Background: The liver is a vital target for sepsis-related injury, leading to inflammatory pathogenesis, multiple organ dysfunction and high mortality rates. Monocyte-derived macrophage transformations are key events in hepatic inflammation. N¹-[(4-methoxy)methyl]-4-methyl-1,2-benzenediamine (FC-99) previously displayed therapeutic potential on experimental sepsis. However, the underlying mechanism of this protective effect is still not clear.

Results: FC-99 treatment attenuated the liver dysfunction in septic mice that was accompanied with reduced numbers of pro-inflammatory Ly6C^hi monocytes in the peripheral blood and CD11b⁺F4/80^lo monocyte-derived macrophages in the liver. These effects were attributed to the FC-99-induced apoptosis of CD11b⁺ cells. In PMA-differentiated THP-1 cells, FC-99 repressed the expression of CD11b, CD14 and caspase3 and resulted in a high proportion of Annexin V⁺ cells. Moreover, let-7a-5p expression was abrogated upon CLP stimulation in vivo, whereas it was restored by FC-99 treatment. TargetScan analysis and luciferase assays indicated that the anti-apoptotic protein BCL-XL was targeted by let-7a-5p. BCL-XL was inhibited by FC-99 in order to induce monocyte apoptosis, leading to the impaired monocyte-to-macrophage differentiation.

Materials and methods: Murine acute liver failure was generated by caecal ligation puncture surgery after FC-99 administration; Blood samples and liver tissues were collected to determine the monocyte/macrophage subsets and the induction of apoptosis. Human acute monocytic leukemia cell line (THP-1) cells were pretreated with FC-99 followed by phorbol-12-myristate-13-acetate (PMA) stimulation, in order to induce monocyte-to-macrophage differentiation. The target of FC-99 and the mechanistic analyses were conducted by microarrays, qRT-PCR validation, TargetScan algorithms and a luciferase report assay.

Conclusions: FC-99 exhibits potential therapeutic effects on CLP-induced liver dysfunction by restoring let-7a-5p levels.

Keywords: FC-99; let-7a-5p; monocyte apoptosis; monocyte-to-macrophage differentiation; sepsis-induced liver injury.