The Role of IL-6 and TMEM100 in Lumbar Discogenic Pain and the Mechanism of the Glycine-Serine-Threonine Metabolic Axis: A Metabolomic and Molecular Biology Study

Zhaoyang Guo; Yuanye Ma; Yaqing Wang; Hongfei Xiang; Shang-You Yang; Zhu Guo; Ronghuan Wang; Wujun Chen; Dongming Xing; Bohua Chen; Hao Tao; Xiaolin Wu

doi:10.2147/JPR.S400871

The Role of IL-6 and TMEM100 in Lumbar Discogenic Pain and the Mechanism of the Glycine-Serine-Threonine Metabolic Axis: A Metabolomic and Molecular Biology Study

J Pain Res. 2023 Feb 15:16:437-461. doi: 10.2147/JPR.S400871. eCollection 2023.

Authors

Zhaoyang Guo^#¹, Yuanye Ma^#¹, Yaqing Wang², Hongfei Xiang¹, Shang-You Yang³, Zhu Guo¹, Ronghuan Wang¹, Wujun Chen⁴, Dongming Xing^{4

5}, Bohua Chen¹, Hao Tao¹, Xiaolin Wu^{1

4}

Affiliations

¹ Department of Orthopedics, The Affiliated Hospital of Qingdao University, Qingdao, People's Republic of China.
² Department of Nephrology, The First Affiliated Hospital of China Medical University, Shenyang, People's Republic of China.
³ School of Medicine-Wichita, University of Kansas, Wichita, KS, USA.
⁴ Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao Cancer Institute, Qingdao, People's Republic of China.
⁵ School of Life Sciences, Tsinghua University, Beijing, People's Republic of China.

^# Contributed equally.

Abstract

Background: It is well established that discogenic low back pain (DLBP) is often caused by the inflammatory response during intervertebral disc degeneration (IDD). However, it remains unclear how inflammatory mediators such as Interleukin-6 (IL-6) are involved in discogenic pain caused by degeneration and intervertebral disc (IVD) metabolism. The purpose of this study is to study the relationship between IL-6 and Transmembrane protein 100 (TMEM100), and to analyze the different metabolites and metabolic pathways in various rat intervertebral discs by metabonomics.

Methods: We established a rat model of IDD-DLBP by disc punctures and PBS infusion to examine the rat pain behaviors. Intervertebral disc tissues were harvested for molecular biology experiments to explore the relationship between IL-6 and TMEM100. High-resolution mass spectrometry (HRMS) was performed for untargeted metabolomics, and nuclear magnetic resonance spectroscopy metabolomics (MRS) for differential metabolites and metabolic pathways.

Results: The results showed a significant decrease in vonFrey test, hot plate test and acetone test (P < 0.05). The expression of IL-6 and TMEM100 in DLBP model was significantly higher than that in sham control group and IDD discs without PBS infusion group (P < 0.05). There were 15 major contributing metabolites identified in the DLBP intervertebral discs through metabolomic studies, involving 6 major metabolic pathways. The main differential metabolites included nitric oxide (NO), ammonia, and lactic acid as the metabolic endpoints; and the differential metabolic pathways included the glycine-serine-threonine (Gly-Ser-Thr), which is gradually weakened with the progression of inflammation.

Conclusion: The change of TMEM100 expression mediated by il-6 is related to the Gly-Ser-Thr metabolic axis and plays an important role in the relief of discogenic pain.

Keywords: DLBP; IDD; IL-6; TMEM100; inflammatory mediators; metabolomics.

Grants and funding

This work was supported by Shandong Provincial Natural Science Foundation (ZR2022MH218); Youth Research Fund of Affiliated Hospital of Qingdao University in 2021 (QDFYQN202101012). The National Natural Science Foundation of China (82172478); National Key Research and Development Project (2019YFC0121404); Shandong Higher Education Young Science and Technology Support Program (2021KJ048); Innovation Fund of National Orthopedics and Sports Rehabilitation Clinical Medicine Research Center (2021-NCRC-CXJJ-ZH-02); The Young Taishan Scholars Program (tsqn201909190); Postdoctoral Science Foundation of China (2021M701813); Qingdao Postdoctoral Applied Research Project (2020).