JEM Yan Min/Tao Yuanxiang team collaborates to reveal the three-dimensional regulatory molecular mechanism of neuropathic pain

Neuropathic pain caused by nerve injury is a chronic and refractory disease.
In the United States alone, more than 6 million people suffer from neuropathic pain for a long time each year
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As current drugs (such as opioids and non-steroidal anti-inflammatory drugs) are not effective in most patients with neuropathic pain, it is urgent to explore new pathogenesis and develop new treatment methods
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Peripheral nerve injury causes changes in the expression of pain-related genes in the primary sensory neurons of the dorsal root ganglion (DRG) at the transcriptional level.
These changes have been confirmed to be related to the development and maintenance of neuropathic pain
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In-depth study of how peripheral nerve injury leads to changes in the expression of these pain-related genes in DRG may provide a new approach for neuropathic pain treatment
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Genome functional elements enhancers and silencers can precisely regulate the activation or suppression of transcription in time and space in a condition-specific manner [1-3]
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Silencer elements are widespread in mammals [1]
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It can rely on inhibitory transcription factors and inhibitory epiregulatory proteins to exert transcriptional inhibition on target genes [4-6]
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November 11, 2021, under the multidisciplinary collaboration of Yuanxiang Tao's research group at Rutgers University, New Jersey State School of Medicine, the Zilkha Institute of Neurogenesis, Keck School of Medicine, University of Southern California, Los Angeles, and the Institute of Pain Medicine, Nantong University, Zhejiang University Medicine The research group of Yan Min from the Second Affiliated Hospital of the hospital published an online study titled ZNF382 controls mouse neuropathic pain via silencer-based epigenetic inhibition of Cxcl13 in DRG neurons in the Journal of Experimental Medicine.
Based on the conformational loop, the zinc finger protein transcription factor ZNF382 binds to the target gene functional element-silencer, and simultaneously recruits a variety of epiregulatory proteins to play a regulatory role on neuropathic pain
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The study first observed that in normal DRG neurons, the expression of ZNF382 was relatively high
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After peripheral nerve injury, the expression of ZNF382 in DRG decreased significantly
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After peripheral nerve injury, the DRG-specific overexpression of ZNF382 on the injured side can significantly alleviate neuropathic pain symptoms in mice
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Through Microarray analysis, it is found that the overexpression of ZNF382 in DRG can significantly inhibit cytokine receptor binding, chemokine activity and other signaling pathways.
Among a series of inhibited pain-causing genes, the expression of chemokine CXCL13 is most significantly inhibited
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CXCL13 is an important pain-causing gene.
The authors found that it is significantly elevated in DRG neurons after peripheral nerve injury and can cause obvious neuropathic pain symptoms
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Through further chromatin immunoprecipitation sequencing (ChIP-seq) and chromatin immunoprecipitation PCR (ChIP-PCR) experiments, it was found that ZNF382 binds to the intergenic fragment about 29555bp upstream of the CXCL13 gene promoter.
If decoy DNA is used to block Breaking the combination of ZNF382 with the intergenic fragment, or excising the fragment with the CRISPR-Cas9 system, can destroy the transcriptional inhibitory effect of ZNF382 on CXCL13 and at the same time weaken the analgesic effect of ZNF382
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Combining the above evidence, this intergenic fragment with a size of 243 bp is likely to be the silencer element of the CXCL13 gene in DRG
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So after the transcription factor ZNF382 is combined with the silencer of CXCL13, how does it remotely regulate the activity of the CXCL13 promoter? The author further confirmed through the chromatin conformation capture experiment (3-C) that the silencer fragment of CXCL13 and its promoter fragment are spatially close to each other, which suggests the existence of the silencer-promoter conformational loop
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In addition, a series of protein immunoprecipitation (Co-IP) results showed that ZNF382 can recruit two apparent regulatory proteins, namely histone deacetylase HDAC1 and histone methylase SETDB1, and ZNF382/HDAC1/ The formation of SETDB1 complex in DRG after peripheral nerve injury is significantly reduced
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The study further found that HDAC1 and SETDB1 simultaneously bind to specific fragments of the promoter region of CXCL13, mediating the modification of ac-H3 and H3K9me3 in the promoter region of CXCL13
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Due to the decreased expression of ZNF382 in DRG, this caused a decrease in the formation of the ZNF382/HDAC1/SETDB1 complex, which further led to a decrease in the binding of HDAC1/SETDB1 in the CXCL13 promoter region.
Correspondingly, the reduced binding of HDAC1 caused histones in the CXCL13 promoter region.
Significantly increased acetylation level and decreased binding of SETDB1 caused a significant decrease in histone methylation level in the CXCL13 promoter region, increased histone acetylation level and decreased methylation level, and the synergistic effect of the two ultimately resulted in the CXCL13 promoter region The transcription activity is enhanced, thereby activating the transcription process of CXCL13
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The down-regulation of ZNF382 expression caused by peripheral nerve injury ultimately makes CXCL13 in a de-inhibited state, and the resulting up-regulation of CXCL13 expression in DRG neurons ultimately mediates the occurrence and maintenance of neuropathic pain
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This article explains the role and mechanism of the zinc finger protein transcription factor ZNF382 in the pathogenesis of neuropathic pain caused by nerve injury from the perspectives of genomic functional elements, chromatin spatial conformation and epigenetic regulation.
It is the first to explore the field of pain The three-dimensional regulation of pain-causing genes provides a new idea for the development of neuropathic pain drugs
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Professor Yan Min from Zhejiang University School of Medicine and Professor Tao Yuanxiang from Rutgers University New Jersey State School of Medicine are the co-corresponding authors of the paper.
The main team members of this article are Dr.
Ma Longfei, Dr.
Yu Lina, Department of Anesthesiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, and Nantong University Pain Medicine Research Researcher Jiang Baochun and postdoctoral fellow Wang Jingkai from the Institute of Orthopaedics of Zhejiang University are the co-first authors of the article
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Original link: https://doi.
org/10.
1084/jem.
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