Sphingosine‐1‐phosphate receptor 3 is implicated in BBB injury via the CCL2‐CCR2 axis following acute intracerebral hemorrhage

Abstract

Background Intracerebral hemorrhage (ICH) is a catastrophic cerebrovascular disease with high morbidity and mortality. Evidence demonstrated that sphingosine‐1‐phosphate receptor (S1PR) plays a vital role in inflammatory damage via the upregulation of CCL2 expression. However, whether S1PR3 is involved in blood‐brain barrier (BBB) breakdown via CCL2 activation after ICH has not been described. Methods We investigated the expression profiles of all S1PRs using high‐throughput RNA‐seq analysis and RT‐PCR. The potential role of S1PR3 and interaction between S1PR3 and CCL2 were evaluated via Western blotting, immunofluorescence, and flow cytometry. BBB disruption was examined via magnetic resonance imaging, transmission electron microscopy, and Evans blue extravasation. Microglial activation, proliferation, and polarization were assessed via histopathological analysis. The expression levels of CCL2, p‐p38 MAPK, ICAM‐1, and ZO‐1 were examined in vitro and in vivo. Results The present results showed that the levels of S1PR3 and its ligand, sphingosine 1‐phosphate (S1P), were dramatically increased following ICH, which regulated the expression of CCL2 and p38MAPK. Moreover, reductions in brain edema volume, amelioration of BBB integrity, and improvements in behavioral deficits were achieved after the administration of CAY10444, an S1PR3 antagonist, to rats. Remarkably increased CCL2, p‐p38MAPK, and ICAM‐1 expression and decreased ZO‐1 expression were observed in cocultured human astrocytes (HAs) and hCMEC/D3 cells after S1P stimulation. However, the expression levels of CCL2, p‐p38 MAPK, and ICAM‐1 were decreased and ZO‐1 expression was increased after S1PR3 inhibition. In addition, microglial proliferation and M1 polarization were attenuated after CAY10444 administration. Conclusion To the best of our knowledge, this is the first demonstration of the neuroprotective role of S1PR3 modulation in maintaining BBB integrity by inhibiting the S1PR3‐CCL2 axis after ICH, providing a novel treatment for ICH by targeting S1PR3.

Differential Regulation of Microglial Activation in Response to Different Degree of Ischemia

“…We found that endothelial markers (Angptl4), and pericyte marker (Cyp1b1, Emp1, S1pr3, Serping1, and Cxcl1) were upregulated in prolonged ischemia. These genes have been reported to be highly associated with the breakdown and restoration of the BBB (32,(80)(81)(82)(83). Therefore, the differential expression of these genes in the 60 min BCAL group suggested that the permeability of the BBB may not be restored at 2 days after BCAL, and subsequently promoted microglial activation.…”

Meningitic Escherichia coli-Induced Interleukin-17A Facilitates Blood–Brain Barrier Disruption via Inhibiting Proteinase 3/Protease-Activated Receptor 2 Axis

“…Accumulating evidence has suggested that host factors and cytokines are involved in the regulation of TJs expression and contribute to BBB dysfunction. For example, cytokines such as TNF-α and IL-6 (Sarami Foroshani et al, 2018;Siqueira et al, 2021), chemokines such as CCL2 and IP-10 ( Wang et al, 2018;Xu D. et al, 2021), and growth factors such as VEGF-A and PDGF-BB (Yang et al, 2016(Yang et al, , 2019 are all reported to induce BBB breakdown. However, there are limited reports on whether IL-17A directly impacts BBB permeability.…”

“…Increased BBB permeability has been reported in numerous diseases, such as neoplasia, hypertension, experimental allergic encephalomyelitis, trauma, and neurotropic viral infections (Scholz et al, 2007;Candelario-Jalil et al, 2009). Inflammatory factors such as tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), C-C motif ligand 2 (CCL2, also known as MCP-1) are reported to mediate BBB breakdown, which ultimately leads to the infiltration of peripheral leukocytes and brain injury (Sarami Foroshani et al, 2018;Siqueira et al, 2021;Xu D. et al, 2021). However, the underlying mechanisms by which these factors regulate BBB permeability in response to infection remain largely unclear.…”

Identification and Characterization of TF-lncRNA Regulatory Networks Involved in the Tumorigenesis and Development of Adamantinomatous Craniopharyngioma

“…The real-time RT-PCR method used was described in our previous study (21). Briefly, oligonucleotide primers and TaqMan probes for KLF5 and E2F2 were designed based on sequences available in the GenBank database.…”

“…The immunohistochemistry method used in the present study has been previously described (18,21). Briefly, sections were incubated overnight at 4°C with the following primary antibodies: rabbit anti-KLF5 (1:1000, Proteintech, China) and rabbit anti-E2F2 (1:1000, Proteintech, China).…”