|
1
|
Wu Q, Ford NC, He S, Zhang C, Cui X, Liu J, Chen X, Cao X, Guan Y, Zang L. Characterizing a new rat model of chronic pain after spine surgery. Bone Res 2025; 13:34. [PMID: 40074742 PMCID: PMC11904174 DOI: 10.1038/s41413-025-00408-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2024] [Revised: 01/14/2025] [Accepted: 01/21/2025] [Indexed: 03/14/2025] Open
Abstract
Chronic pain after spine surgery (CPSS) is a complex disorder characterized by multifactorial pathogenesis that occurs in 8%-40% of patients undergoing lumbar spine surgery. We aimed to develop a rat model that mimics clinical CPSS conditions by taking two sequential surgical procedures. Step 1: A plastic rod was inserted into the left L5 intervertebral foramen to produce a steady compression on the dorsal root ganglion (DRG) and the spinal nerve, a common cause of low back pain (LBP). Step 2: The rod was removed after 7 days when rats exhibited mechanical and heat hypersensitivity in the ipsilateral hindpaw, followed by a full L5 laminectomy to mimic spine decompression surgery in LBP patients. The retention of the rod induced a prolonged LBP-like behavior but was quickly resolved after rod removal without laminectomy. However, rats that received laminectomy after rod removal developed heightened mechanical and heat sensitivity in the hindpaw, impaired gait, and reduced spontaneous exploration activity, indicating CPSS. Patch clamp recording revealed a significant augmentation in the intrinsic excitability of small-diameter DRG neurons in CPSS rats. Administration of Dermorphin [D-Arg2, Lys4] (1-4) amide (DALDA, 5 mg /kg, i.p.), a peripherally acting mu-opioid receptor (MOR)-preferred agonist, attenuated pain hypersensitivity, capsaicin-induced [Ca2+]i rising and the increased intrinsic excitability of DRG neurons from CPSS rats. Our findings suggest that this new model, which mirrors the nature of CPSS developed in patients, may be useful for future studies of the underlying mechanisms.
Collapse
Affiliation(s)
- Qichao Wu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
- Department of Orthopedics, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Neil C Ford
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Shaoqiu He
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Chi Zhang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Xiang Cui
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Jing Liu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Xueming Chen
- Department of Orthopedics, Beijing Luhe Hospital, Capital Medical University, Beijing, China
| | - Xu Cao
- Department of Orthopedics, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
- Department of Neurological Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
| | - Lei Zang
- Department of Orthopedics, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
| |
Collapse
|
|
2
|
Yu J, Li D, Xie M, Xie J, Wang Z, Gu X, Ma Z, Sun Y. Complex Topology of Ubiquitin Chains Mediates Lysosomal Degradation of MrgC Proteins. Cell Biochem Biophys 2024; 82:641-645. [PMID: 38291169 DOI: 10.1007/s12013-023-01204-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 11/28/2023] [Indexed: 02/01/2024]
Abstract
BACKGROUND Activation of Mas-related G protein-coupled receptor C (MrgC) receptors relieves pain, but also leads to ubiquitination of MrgC receptors. Ubiquitination mediates MrgC receptor endocytosis and degradation. However, MrgC degradation pathways and ubiquitin-linked chain types are not known. METHODS N2a cells were treated with cycloheximide (CHX, protein synthesis inhibitor), Mg132 (proteasome inhibitor), 3-Methyladenine (3MA, autophagy lysosome inhibitor) and Chloroquine (CQ, autophagy lysosome inhibitor) to observe the half-life and degradation pathway of MrgC. The location of internalized MrgC receptors and lysosomes (Lyso-Tracker) was observed by immunofluorescence staining. N2a cells were transfected with Myc-MrgC and a series of HA-tagged ubiquitin mutants to study the ubiquitin-linked chain type of MrgC. RESULTS The amount of MrgC protein decreased with time after CHX treatment of N2a cells. Autophagy lysosome inhibitors can inhibit the degradation of MrgC. The amount of MrgC protein decreased with time after CHX treatment of N2a cells. 3-MA and CQ inhibited the degradation of MrgC protein, whereas Mg-132 did not inhibit it. Partially internalized MrgC receptors were co-labeled with lysosomes. MrgC proteins have multiple topologies of ubiquitin-modified chains. CONCLUSION As a member of the G protein-coupled receptor family, MrgC receptors can be degraded over time. The complex topology of the ubiquitin-linked chain mediates the lysosomal degradation of MrgC proteins.
Collapse
Affiliation(s)
- Jiacheng Yu
- Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, 210023, China
| | - Dan Li
- Nanjing Drum Tower Hospital Clinical College of Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Mingming Xie
- Nanjing Drum Tower Hospital Clinical College of Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Jun Xie
- Nanjing Drum Tower Hospital Clinical College of Jiangsu University, Nanjing, 210023, China
| | - Zhen Wang
- Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, 210023, China
| | - Xiaoping Gu
- Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, 210023, China
| | - Zhengliang Ma
- Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, 210023, China
| | - Yu'e Sun
- Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, 210023, China.
- Nanjing Drum Tower Hospital Clinical College of Nanjing University of Chinese Medicine, Nanjing, 210023, China.
- Nanjing Drum Tower Hospital Clinical College of Jiangsu University, Nanjing, 210023, China.
- Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, 210023, China.
| |
Collapse
|
|
3
|
Yu J, Hou B, Huang Y, Wang X, Qian Y, Liang Y, Gu X, Ma Z, Sun Y. USP48 alleviates bone cancer pain and regulates MrgC stabilization in spinal cord neurons of male mice. Eur J Pain 2023. [PMID: 36864656 DOI: 10.1002/ejp.2102] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/19/2023] [Accepted: 02/21/2023] [Indexed: 03/04/2023]
Abstract
BACKGROUND Ubiquitin-mediated degradation of the Mas-related G protein-coupled receptor C (MrgC) reduces the number of receptors. However, the specific deubiquitinating enzyme antagonize this process has not been reported. In this study, we investigated the effect of ubiquitin-specific protease-48 (USP48) on bone cancer pain (BCP) and its effect on MrgC. METHODS A mouse model of BCP was established. BCP behaviours of mice were assessed after intrathecal injection of adeno-associated virus (AAV)-USP48. USP48 and MrgC interactions were studied by immunoprecipitation. Overexpression and knockdown of USP48 were conducted in N2a cells to investigate the effect of USP48 on MrgC receptor number and ubiquitination. RESULTS Spinal cord level USP48 expression was reduced in mice with BCP. Intrathecal injection of AAV-USP48 increased paw withdrawal mechanical threshold and reduced spontaneous flinching in mice. In N2a cells, there were increased number of MrgC receptors after overexpression of USP48 and decreased number of MrgC receptors after knockdown of USP48. USP48 interacted with MrgC and overexpression of USP48 altered the level of ubiquitination of MrgC. CONCLUSION USP48 antagonizes ubiquitin-mediated autophagic degradation of MrgC and alleviates BCP in a murine animal model. Our findings may provide a new perspective for the treatment of BCP. SIGNIFICANCE Our finding may provide an important theoretical basis as well as an intervention target for clinical development of drugs for BCP.
Collapse
Affiliation(s)
- Jiacheng Yu
- Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Bailing Hou
- Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Yulin Huang
- Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Xiaoyu Wang
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China
| | - Yue Qian
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China
| | - Ying Liang
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China
| | - Xiaoping Gu
- Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Zhengliang Ma
- Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Yue Sun
- Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| |
Collapse
|