Achilles' Heel-The Significance of Maintaining Microenvironmental Homeostasis in the Nucleus Pulposus for Intervertebral Discs

Int J Mol Sci. 2023 Nov 22;24(23):16592. doi: 10.3390/ijms242316592.

Abstract

The dysregulation of intracellular and extracellular environments as well as the aberrant expression of ion channels on the cell membrane are intricately linked to a diverse array of degenerative disorders, including intervertebral disc degeneration. This condition is a significant contributor to low back pain, which poses a substantial burden on both personal quality of life and societal economics. Changes in the number and function of ion channels can disrupt the water and ion balance both inside and outside cells, thereby impacting the physiological functions of tissues and organs. Therefore, maintaining ion homeostasis and stable expression of ion channels within the cellular microenvironment may prove beneficial in the treatment of disc degeneration. Aquaporin (AQP), calcium ion channels, and acid-sensitive ion channels (ASIC) play crucial roles in regulating water, calcium ions, and hydrogen ions levels. These channels have significant effects on physiological and pathological processes such as cellular aging, inflammatory response, stromal decomposition, endoplasmic reticulum stress, and accumulation of cell metabolites. Additionally, Piezo 1, transient receptor potential vanilloid type 4 (TRPV4), tension response enhancer binding protein (TonEBP), potassium ions, zinc ions, and tungsten all play a role in the process of intervertebral disc degeneration. This review endeavors to elucidate alterations in the microenvironment of the nucleus pulposus during intervertebral disc degeneration (IVDD), with a view to offer novel insights and approaches for exploring therapeutic interventions against disc degeneration.

Keywords: ASIC; calcium ion; intervertebral disc degeneration; metallic elements; nucleus pulposus; osmotic pressure.

Publication types

  • Review

MeSH terms

  • Homeostasis / physiology
  • Humans
  • Intervertebral Disc Degeneration* / metabolism
  • Intervertebral Disc* / metabolism
  • Ion Channels / metabolism
  • Ions / metabolism
  • Nucleus Pulposus* / metabolism
  • Quality of Life
  • Water / metabolism

Substances

  • Ion Channels
  • Ions
  • Water

Grants and funding

This research was supported by the Natural Science Foundation of Gansu province (Grant No. 20JR10RA748), the Gansu Province Youth Science and Technology Fund Program (Grant No. 20JR10RA761), the National Natural Sciences Foundation of China (Grant No. 82272536), the Natural Science Foundation of Gansu province (Grant No. 22JR5RA949), the Lanzhou University Innovation and Entrepreneurship Cultivation Project (Grant No. cxcy2023012), and the Medical Innovation and Development Project of Lanzhou University (Grant No. lzuyxcx2022190).