Title:Heme Oxygenase-1 may Mediate Early Inflammatory Response of Intracerebral
Hemorrhage through Toll-like Receptor 4 Signaling Pathway
Volume: 19
Issue: 2
Author(s): Yuejia Song, Ke Li, Zhen Zhang, Qi Liu, Yu Wang and Jiping Qi*
Affiliation:
- Department of Pathology, First Affiliated Hospital, Harbin Medical University, Harbin 150001, China
Keywords:
Heme oxygenase-1, toll-like receptor 4, intracerebral hemorrhage, microglia, inflammation, neuroinflammation.
Abstract:
Objective: The aim of this study was to investigate whether heme oxygenase-1 (HO-1)
promotes an early neuroinflammatory response after intracerebral hemorrhage (ICH) by regulating
the toll-like receptor 4 (TLR4) signaling pathway.
Methods: We used a stereotaxic instrument to induce a mouse model of ICH through collagenase.
We divided the participants into a control group, an ICH group, and an ICH and zinc protoporphyrin
IX (ZnPP) group. The temporal expression pattern and cell localization of HO-1 and TLR4 after the
ICH were detected by immunofluorescence and western blot; after the expression of HO-1 was inhibited,
the expression levels of the TLR4 protein, the downstream molecule myeloid differentiation
factor 88 (MyD88), the Toll and interleukin-1 receptor (TIR) -domain-containing adapter-inducing
interferon-β (TRIF) and the inflammatory factors were measured by western blotting.
Results: Immunofluorescence showed that HO-1 and TLR4 had similar temporal expression patterns
and cellular localization after ICH, and we found that inhibiting HO-1 reduces the expression
of TLR4 protein pathways, including TLR4, MyD88, TRIF, and related inflammatory factors, by
studying the inhibitor ZnPP.
Conclusion: These results indicate that HO-1 may promote early neuroinflammation after ICH
through the TLR4/MyD88/TRIF signaling pathway.