The Novel HDAC8 Inhibitor WK2-16 Attenuates Lipopolysaccharide-Activated Matrix Metalloproteinase-9 Expression in Human Monocytic Cells and Improves Hypercytokinemia In Vivo.

Chih-Kuang Chen,Wei-Jan Huang,Yung-Chen Chou,Yu-Wen Cheng,George Hsiao,Jing-Shiun Jan

doi:10.3390/ijms18071394

Abstract

Dysregulated human monocytes/macrophages can synthesize and secrete matrix metalloproteinases (MMPs), which play important roles in the progression of sepsis. In this study, we investigated the effects and mechanism of a novel histone deacetylase (HDAC8) inhibitor, (E)-N-hydroxy-4-methoxy-2-(biphenyl-4-yl)cinnamide (WK2-16), on MMP-9 production and activation in stimulated human monocytic THP-1 cells. Our results demonstrated that the acetylation level of structural maintenance of chromosomes 3 (SMC3) was up-regulated by WK2-16 in THP-1 cells. Consistently, an in vitro enzyme study demonstrated that WK2-16 selectively inhibited HDAC8 activity. Moreover, the WK2-16 concentration dependently suppressed MMP-9-mediated gelatinolysis induced by tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS). Additionally, WK2-16 significantly inhibited both MMP-9 protein and mRNA expression without cellular toxicity. Nevertheless, WK2-16 suppressed the extracellular levels of interleukin (IL)-6 from LPS-stimulated THP-1 cells. For the signaling studies, WK2-16 had no effect on LPS/TLR4 downstream signaling pathways, such as the NF-κB and ERK/JNK/P38 MAPK pathways. On the other hand, WK2-16 enhanced the recruitment of acetylated Yin Yang 1 (YY1) with HDAC1. Finally, in vivo studies indicated that WK2-16 could reduce the serum levels of TNF-α and IL-6 in endotoxemic mice. These results suggested that HDAC8 inhibition might provide a novel therapeutic strategy of hypercytokinemia in sepsis.

Highlights

Sepsis is defined as a life-threatening organ dysfunction caused by an abnormal host response to infection [1]
THP-1 cells were pretreated with WK2-16 (5, 10 and 20 μM), the pan-Histone deacetylases (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) (10 μM) or vehicle (DMSO) for 15 min followed by the addition of LPS (50 ng/mL)
THP-1 cells were pretreated with WK2-16 (2, 5, 10 and 20 μM) for 15 min followed by the addition of LPS (50 ng/mL), tumor necrosis factor-α (TNF-α) (10 ng/mL), phorbol 12-myristate 13-acetate (PMA) (10 μM) or Transforming growth factor (TGF)-β (10 ng/mL)

Summary

Introduction

Sepsis is defined as a life-threatening organ dysfunction caused by an abnormal host response to infection [1]. In the acute phase of severe sepsis, hypercytokinemia of the systemic cytokine storm may dysregulate the immune balance and enhance tissue damage and organ failure [2]. Because phagocytic cells are the major source of inflammatory mediators, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and matrix metalloproteinases (MMPs) [8,9,10], involved in the pathogenesis of sepsis. Recent studies have suggested that the serum levels of MMP-9 and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are associated with mortality and organ injury [10,12,13,14]. The reduction of the MMP-mediated inflammatory response may improve the outcome of sepsis

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Discussion

Conclusion