1. Academic Validation
  2. Thrombin increases the expression of cholesterol 25-hydroxylase in rat astrocytes after spinal cord injury

Thrombin increases the expression of cholesterol 25-hydroxylase in rat astrocytes after spinal cord injury

  • Neural Regen Res. 2023 Jun;18(6):1339-1346. doi: 10.4103/1673-5374.357905.
Chen Chen 1 Huiyuan Ji 2 Nan Jiang 3 Yingjie Wang 4 Yue Zhou 3 Zhenjie Zhu 3 Yuming Hu 3 Yongjun Wang 4 Aihong Li 5 Aisong Guo 6
Affiliations

Affiliations

  • 1 Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University; Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China.
  • 2 Department of Rehabilitation Medicine, The Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China.
  • 3 Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China.
  • 4 Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China.
  • 5 Department of Neurology, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China.
  • 6 Department of Traditional Chinese Medicine, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China.
Abstract

Astrocytes are important cellular centers of Cholesterol synthesis and metabolism that help maintain normal physiological function at the organism level. Spinal cord injury results in aberrant Cholesterol metabolism by astrocytes and excessive production of oxysterols, which have profound effects on neuropathology. 25-Hydroxycholesterol (25-HC), the main product of the membrane-associated Enzyme cholesterol-25-hydroxylase (CH25H), plays important roles in mediating neuroinflammation. However, whether the abnormal astrocyte Cholesterol metabolism induced by spinal cord injury contributes to the production of 25-HC, as well as the resulting pathological effects, remain unclear. In the present study, spinal cord injury-induced activation of Thrombin was found to increase astrocyte CH25H expression. A Protease-activated Receptor 1 inhibitor was able to attenuate this effect in vitro and in vivo. In cultured primary astrocytes, Thrombin interacted with Protease-activated Receptor 1, mainly through activation of the mitogen-activated protein kinase/nuclear factor-kappa B signaling pathway. Conditioned culture medium from astrocytes in which ch25h expression had been knocked down by siRNA reduced macrophage migration. Finally, injection of the Protease activated receptor 1 inhibitor SCH79797 into rat neural sheaths following spinal cord injury reduced migration of microglia/macrophages to the injured site and largely restored motor function. Our results demonstrate a novel regulatory mechanism for thrombin-regulated Cholesterol metabolism in astrocytes that could be used to develop anti-inflammatory drugs to treat patients with spinal cord injury.

Keywords

25-hydroxycholesterol; PAR1; astrocyte; chemotaxis; cholesterol metabolism; cholesterol-25-hydroxylase; lipid homeostasis; macrophage; spinal cord injury; thrombin.

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