1. Academic Validation
  2. The Role of Sphingomyelin Metabolism in the Protection of Rat Brain Microvascular Endothelial Cells by Mild Hypothermia

The Role of Sphingomyelin Metabolism in the Protection of Rat Brain Microvascular Endothelial Cells by Mild Hypothermia

  • Neurocrit Care. 2022 Apr;36(2):546-559. doi: 10.1007/s12028-021-01338-6.
Hai-Hong Zhang  # 1 Lin Wang  # 2 Wei Zhang 1 Zhi Wan 3
Affiliations

Affiliations

  • 1 Department of Emergency Medicine, West China Hospital, Sichuan University, 37 Guoxue Road, Chengdu, 610041, Sichuan, China.
  • 2 Department of Cardiology, West China Hospital, Sichuan University, Chengdu, China.
  • 3 Department of Emergency Medicine, West China Hospital, Sichuan University, 37 Guoxue Road, Chengdu, 610041, Sichuan, China. 303680215@qq.com.
  • # Contributed equally.
Abstract

Background: Sphingomyelin, composed of ceramide (CER), sphingosine (Sph), and sphingosine-1-phosphate (S1P), is an essential structural component of cellular membranes and plays an important role in the signal transduction regulating cell proliferation, differentiation, and Apoptosis. CER is mainly metabolized to Sph, and under the action of sphingosine kinases (SphKs), Sph produces S1P, which can be converted back to Sph by S1P Phosphatase. It is suggested that the fate of cells is controlled partly by the interconversion of CER and intracellular S1P. SphK2 is considered the main kinase of S1P synthesis in the central nervous system. The objective of this study was to explore the hypothesis that SphK2 and sphingomyelin metabolism participated in the process of cell Apoptosis and the protection of mild hypothermia.

Methods: Rat brain microvascular endothelial cells were divided into groups for intervention of SphK2 Inhibitor, SphK2 small interfering RNA (SiRNA) transfection, ischemia-reperfusion, and mild hypothermia. After interventions, cell Apoptosis was detected by 4,6-diamino-2-phenyl indole (DAPI) and flow cytometry, the expression of apoptosis-related protein was detected by Western Blot, and SphK2 Enzyme activity and the content of sphingomyelin were determined.

Results: ABC294640 and transfection of SphK2 SiRNA could increase Apoptosis, accompanied by the increase of the expression of proapoptotic genes Caspase3 and Bax and the decrease of the expression of Bcl-2. This effect could be partially reversed with mild hypothermia. Ischemia-reperfusion injury, transfection of SphK2 SiRNA, and the addition of ABC294640 could significantly inhibit the activity of SphK2, accompanied by the increase of CERs and the decrease of S1P. Mild hypothermia could reverse the changes of sphingolipids but have no significant effect on the activity of SphK2.

Conclusions: Mild hypothermia can inhibit the occurrence of Apoptosis and reverse the changes of apoptosis-related genes and sphingomyelin content induced by ischemia-reperfusion injury, but the effect on sphk2 Enzyme activity was not significant.

Keywords

Apoptosis; Cerebral microcirculation; Ischemia–reperfusion injury; Mild hypothermia; Sphingomyelin metabolism.

Figures
Products
  • Cat. No.
    Product Name
    Description
    Target
    Research Area
  • HY-16015
    99.94%, SphK Inhibitor