NEMO-binding domain peptides alleviate perihematomal inflammation injury after experimental intracerebral hemorrhage

Qinghua Luo  ¹ , Dongling Li  ¹ , Bing Bao  ² , Xiaolin Wan  ¹ , Bingxing Pan  ³ , Jianglong Tu  ¹ , Han Wang  ⁴ , Yetong Ouyang  ⁴ , Zhiying Chen  ⁵ , Xiaoping Yin  ⁶

• ¹ Department of Neurology, The Second Affiliated Hospital of Nanchang University, No. 1, Minde Road, Nanchang 330006, Jiangxi Province, China.
• ² Department of Neurology, The Affiliated Hospital of Jiujiang University, No. 57, Xiangyang East Road, Jiujiang 332000, Jiangxi Province, China.
• ³ Department of Neurology, The Second Affiliated Hospital of Nanchang University, No. 1, Minde Road, Nanchang 330006, Jiangxi Province, China; Laboratory of Fear and Anxiety Disorders, Institute of Life Science and School of Life Science, Nanchang University, No. 999, Xuefu Avenue, Nanchang 330031, Jiangxi Province, , China.
• ⁴ Department of Neurology, The Affiliated Hospital of Jiujiang University, No. 57, Xiangyang East Road, Jiujiang 332000, Jiangxi Province, China; Department of Neurology, The Second Affiliated Hospital of Nanchang University, No. 1, Minde Road, Nanchang 330006, Jiangxi Province, China.
• ⁵ Department of Neurology, The Affiliated Hospital of Jiujiang University, No. 57, Xiangyang East Road, Jiujiang 332000, Jiangxi Province, China. Electronic address: chenzhiying0627@126.com.
• ⁶ Department of Neurology, The Affiliated Hospital of Jiujiang University, No. 57, Xiangyang East Road, Jiujiang 332000, Jiangxi Province, China. Electronic address: xiaopingbuxiao@126.com.

Abstract

Inflammation aggravates the lethal consequences of intracerebral hemorrhage. Recently, many studies have found that nuclear factor-κB (NF-κB) is a crucial transcription factor that initiates inflammation in the perihematomal region of ICH. NF-κB essential modulator (NEMO)-binding domain (NBD) peptide, a cell-permeable peptide spanning the NBD of IKKα or IKKβ, functions as a highly specific inhibitor of NF-κB. This peptide can negatively regulate the NF-κB pathway. The present study aimed to explore the effects and underlying pathomechanisms of NBD peptides after ICH. Striatum infusion of whole blood or saline was performed on C57BL/6 mice (n = 198). Experimental animals were administered NBD or control (mutated) peptides 2 h before or after ICH by intracerebroventricular injection (icv.). NBD peptides significantly inhibited edema formation, ameliorated the neurological deficits, markedly reduced IκBα and p65 phosphorylation, blocked nuclear translocation of p65, and upregulated IκBα expression by NF-κB after ICH induction. Using an in vitro hemin toxicity model, we investigated the effects of NBD peptides on microglial inflammation. We found that NBD peptides suppressed microglia inflammation and lowered the expression of TNF-α and IL-1β in both in vivo and in vitro experiments. Further experiments were performed in mice and cultured microglia, which treated with NBD peptides in the presence of p65 siRNA confirmed that the specificity of NBD peptides inhibit ICH-induced NF-κB activation. This study demonstrated that NBD peptides exert a neuroprotective role after ICH and might be a potential candidate for a novel therapeutic strategy for ICH.

Keywords: NBD peptide; intracerebral hemorrhage; microglia; neuroinflammation.