Title:Albumin Induces Neuroprotection Against Ischemic Stroke by Altering Toll-Like Receptor 4 and Regulatory T Cells in Mice
Volume: 12
Issue: 2
Author(s): Min Wang, Yongming Wang, Jing He, Siyu Wei, Na Zhang, Fengyong Liu, Xin Liu, Yi Kang and Xiaomei Yao
Affiliation:
Keywords:
Albumin, Toll-like receptor 4, regulatory T cell, Middle Cerebral Artery Occlusion, interleukin-10, transforming
growth factor beta1.
Abstract: The objective of this study was to characterize the effect of albumin therapy on the expression of Toll-like
receptor 4 (TLR 4), anti-inflammation cytokines and CD4+CD25+forkhead box P3 (Foxp3)+ regulatory T lymphocytes
(Treg cells) in the ischemic brain and peripheral immune system after Middle Cerebral Artery Occlusion (MCAO). Adult
male Kunming mice were subjected to MCAO, the suture was withdrawn 2 h later followed by an intravenous
administration of 25% albumin (1.25 g/kg) or saline (5 ml/kg) through caudal vein. We demonstrated that albumin
administration elevated the serum albumin level supranormally at 6 h and 24 h after MCAO in mice. In addition, we
showed that both in the ischemic brain and in the spleen, albumin administration significantly depressed the increase of
TLR 4 mRNA expression by quantitative real-time polymerase chain reaction (QRT-PCR), and significantly increase the
anti-inflammatory related interleukin-10 (IL-10) and transforming growth factor beta1 (TGF-β1) mRNA expression by
transcription-polymerase chain reaction (RT-PCR) after MCAO. In the spleen, compared to sham group, strong TLR 4
immunoreactivity was noted in the saline group; while compared to saline group, albumin administration markedly
reduced the immunoreactivity of TLR 4 after MCAO by immunohistochemistry. Moreover, albumin administration
significantly increased the percentage of Treg in spleen CD4+ cells by flow cytometry. In conclusion, the decrease of TLR
4 expression and the increase of Treg cell, IL-10, and TGF-β1 expression may partly contribute to the neuroprotective
effect of albumin therapy on MCAO induced immune inflammatory responses.
