Novel Elongator Protein 2 Inhibitors Mitigating Tumor Necrosis Factor-α Induced Osteogenic Differentiation Inhibition.

Wen-Jiao Wu,Yong Qi,Yun-Fei Ma,Chang-Liang Xia,Shuan-Ji Ou,Yi-Long Hou,Jian-Wei Li,Qing-Po Yang,Jun Zhang,Yang Yang,Chang-Peng Xu,Fabiano Bini

doi:10.1155/2021/3664564

Abstract

Tumor necrosis factor-α is a common cytokine that increases in inflammatory processes, slows the differentiation of bone formation, and induces osteodystrophy in the long-term inflammatory microenvironment. Our previous study confirmed that the Elongation protein 2 (ELP2) plays a significant role in osteogenesis and osteogenic differentiation, which is considered a drug discovery target in diseases related to bone formation and differentiation. In this study, we applied an in silico virtual screening method to select molecules that bind to the ELP2 protein from a chemical drug molecule library and obtained 95 candidates. Then, we included 11 candidates by observing the docking patterns and the noncovalent bonds. The binding affinity of the ELP2 protein with the candidate compounds was examined by SPR analysis, and 5 out of 11 compounds performed good binding affinity to the mouse ELP2 protein. After in vitro cell differentiation assay, candidates 2# and 5# were shown to reduce differentiation inhibition after tumor necrosis factor-α stimulation, allowing further optimization and development for potential clinical treatment of inflammation-mediated orthopedic diseases.

Highlights

Persistent bone tissue inflammation, such as bone fractures and rheumatoid arthritis (RA), destroys the bone formation and absorption balance, which reduces bone mass and results in significant impact on bone regeneration [1]
In the ligand-docking stage, the Elongation protein 2 (ELP2) model and the entire ligand library were first applied to perform a high-throughput virtual screening (HT-VS), and 11,216 compounds were passed. These screened compounds were further analyzed by the standard precision (SP) and extraprecision (XP) glide docking models. 397 hits belonging to 102 clusters were retrieved from the Glide SP docking with a docking score cut-off value of -6.0 kcal/mol
To determine the effect of the candidate compounds on TNF-αinduced osteogenic differentiation inhibition, we examined the activity of osteogenic marker alkaline phosphatase in the cells

Summary

Introduction

Persistent bone tissue inflammation, such as bone fractures and rheumatoid arthritis (RA), destroys the bone formation and absorption balance, which reduces bone mass and results in significant impact on bone regeneration [1]. Elongation protein 2 (ELP2) is a subordinate of the ELP123 complex and regulates the activity of elongation protein by integrating signals from various factors. It affects the inflammatory response through the JAK-STAT3 cascade and downstream pathways [4]. Our previous research identified the role of ELP2 in regulating TNF-α-induced osteoblast differentiation inhibition. A mechanistic study concluded that ELP2 blocked the osteogenic differentiation induced by BMP-2 through activation the STAT3 pathway and downregulating the utterance of BMPR2, thereby slowing the process of early bone tissue formation in the inflammatory microenvironment [5]. ELP2 was shown to be the potential drug target to develop novel therapeutic for inflammation-induced bone loss

Methods

Results

Conclusion