S1PR3, as a Core Protein Related to Ischemic Stroke, is Involved in the Regulation of Blood–Brain Barrier Damage

Abstract

Background: Ischemic stroke is the most common stroke incident. Sphingosine-1-phosphate (S1P) receptor 3 (S1PR3) is a member of the downstream G protein-coupled receptor family of S1P. The effect of S1PR3 on ischemic stroke remains elusive.Methods: We downloaded two middle cerebral artery occlusion (MCAO) microarray datasets from the Gene Expression Omnibus (GEO) database and screened differentially expressed genes (DEGs). Then, we performed a weighted gene coexpression network analysis (WGCNA) and identified the core module genes related to ischemic stroke. We constructed a protein–protein interaction (PPI) network for the core genes in which DEGs and WGCNA intersected. Finally, we discovered that S1PR3 was involved as the main member of the red proteome. Then, we explored the mechanism of S1PR3 in the mouse tMCAO model. The S1PR3-specific inhibitor CAY10444 was injected into the abdominal cavity of mice after cerebral ischemia/reperfusion (I/R) injury, and changes in the expression of blood–brain barrier-related molecules were measured using PCR, western blotting, and immunofluorescence staining.Results: Both GEO datasets showed that S1PR3 was upregulated during cerebral I/R in mice. WGCNA revealed that the light yellow module had the strongest correlation with the occurrence of IS. We determined the overlap with DEGs, identified 146 core genes that are potentially related to IS, and constructed a PPI network. Finally, S1PR3 was found to be the main member of the red proteome. In the mouse cerebral I/R model, S1PR3 expression increased 24 h after ischemia. After the administration of CAY10444, brain edema and neurological deficits in mice were ameliorated. CAY10444 rescued the decreased expression of the tight junction (TJ) proteins zonula occludens 1 (ZO1) and occludin after ischemia induced by transient MCAO (tMCAO) and reduced the increase in aquaporin 4 (AQP4) levels after tMCAO, preserving the integrity of the BBB. Finally, we found that S1PR3 is involved in regulating the mitogen-activated protein kinase (MAPK) and (phosphatidylinositol-3 kinase/serine-threonine kinase) PI3K-Akt signaling pathways.Conclusion: S1PR3 participates in the regulation of blood–brain barrier damage after cerebral I/R. S1PR3 is expected to be an indicator and predictor of cerebral ischemia, and drugs targeting S1PR3 may also provide new ideas for clinical medications.

Laquinimod Inhibits Microglial Activation, Astrogliosis, BBB Damage, and Infarction and Improves Neurological Damage after Ischemic Stroke

“…Ischemic injury causes an increase of AQP4 expression perivascular astrocyte swelling . It has been demonstrated that, after MCAO, the AQP4 protein level was upregulated, and expanded around the blood vessels in the mouse brain, and our results also confirmed a similar trend of AQP4 after ischemic injury in the present study. Therefore, LAQ treatment reduced the increased expression of AQP4, indicating that the neuroprotective effect of LAQ may be involved in the downregulation and redistribution of AQP4.…”

Spatiotemporal sphingosine-1-phosphate receptor 3 expression within the cerebral vasculature after ischemic stroke

“…For the first time to our knowledge, this study provides evidence of higher S1PR3 plasma levels in murine and human ischemic stroke and thus, supports findings obtained in a proteomic assessment of peripheral blood mononuclear cells (PBMCs) that identified S1PR3 as one of 146 core genes potentially related to ischemic stroke. 68 Using receiver operating characteristic (ROC) analysis, the authors suggested S1PR3 as good ischemic stroke indicator. 68 However, care must be taken when interpreting and generalizing these findings because of their small sample size (i.e., 20 stroke patients and 20 control subjects) without available information on sampling timepoint post-stroke, stroke severity or sex of the participating subjects.…”

“… 68 Using receiver operating characteristic (ROC) analysis, the authors suggested S1PR3 as good ischemic stroke indicator. 68 However, care must be taken when interpreting and generalizing these findings because of their small sample size (i.e., 20 stroke patients and 20 control subjects) without available information on sampling timepoint post-stroke, stroke severity or sex of the participating subjects. Although high S1PR3 levels in patients with acute stroke were not associated with neurological impairment, worse general outcome, or inflammation in our study, S1PR3 signaling may still be an interesting target to consider for further stroke therapy studies.…”

LRRK2 kinase activity restricts NRF2-dependent mitochondrial protection in microglia

“…In addition to acting as a protective factor in neurodegenerative disease, activation of NRF2 also ameliorates damage caused from ischemic stroke where it protects the BBB, improves edema, and mitigates neurological defects by reducing oxidative stress (69,72). It is also likely that NRF2 activation restricts the overactivation of type I IFN by microglia which occurs during the acute phase of stroke with deleterious consequences (73).…”