Salidroside Restores an Anti-inflammatory Endothelial Phenotype by Selectively Inhibiting Endothelial Complement After Oxidative Stress
Salidroside, an active component of Rhodiola rosea, reduces inflammation and neuronal damage after middle cerebral artery occlusion (MCAO) with reperfusion, partly by inhibiting cerebral complement C3 activation. However, the mechanisms of this inhibition are not fully understood. In this study, we investigated which cerebral cells might contribute to the inhibition of complement by salidroside and the consequences of this inhibition. We used human umbilical endothelial cells (HUVEC) as a model of cerebral endothelium and found that salidroside prevented the increases of C3 and its active fragment C3a, and the associated increases in C1q and C2, otherwise caused by oxygen-glucose deprivation followed by restoration (OGD/R). However, salidroside did not affect C1q, C2 or C3 in astrocytes and microglial BV2 cells after OGD/R. Salidroside also prevented the decreases in CD46 and CD59, and the increases in VCAM-1, ICAM-1, P-selectin and E-selectin caused by OGD/R in HUVEC, which were associated with decreasing LDH release and increasing Bcl-2/Bax ratio. None of these effects of salidroside occurred in the absence of oxygen-glucose restoration. Moreover, salidroside and C3a receptor antagonist reduced the markers of endothelial activation and neutrophil adhesion to HUVEC after OGD/R to similar extents, and their effects were not additive. Correspondingly, salidroside reduced the markers of endothelial activation and neutrophilic infiltration in the rat brains after MCAO with reperfusion. These results suggest endothelium is an important locus of inhibition of complement by salidroside, restoring an anti-inflammatory endothelial phenotype after oxidative stress, partly by inhibiting classical complement activation and partly by increasing CD46 and CD59, in association with anti-apoptotic effects. These endothelial effects may contribute to the protection afforded by salidroside in cerebral ischemia-reperfusion injury.
KEY WORDScomplement endothelial cells inflammation salidroside stroke
The authors thank the staff in the Animal Center of the Fujian University of TCM for their technical support.
This work was supported by the National Natural Science Foundation of China (projects 81473382 and 81603323), the Collaborative Innovation Center for Rehabilitation Technology of Fujian University of TCM, the TCM Rehabilitation Research of SATCM (X2018002-Collaborative) and the Young Talent Training Project provided by the Health Committee of Fujian Province (2019-ZQN-74).
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no competing interests.
- 6.Thiel, S., T. Vorup-Jensen, C.M. Stover, W. Schwaeble, S.B. Laursen, K. Poulsen, A.C. Willis, P. Eggleton, S. Hansen, U. Holmskov, K.B. Reid, and J.C. Jensenius. 1997. A second serine protease associated with mannan-binding lectin that activates complement. Nature 386 (6624): 506–510.PubMedCrossRefGoogle Scholar
- 13.Zhang, X., W. Lai, X. Ying, L. Xu, K. Chu, J. Brown, L. Chen, and G. Hong. 2019. Salidroside reduces inflammation and brain injury after permanent middle cerebral artery occlusion in rats by regulating PI3K/PKB/Nrf2/NFkappaB signaling rather than complement C3 activity. Inflammation 42: 1830–1842. https://doi.org/10.1007/s10753-019-01045-7.CrossRefPubMedGoogle Scholar
- 14.Dimpfel, W., L. Schombert, and A.G. Panossian. 2018. Assessing the quality and potential efficacy of commercial extracts of rhodiola rosea l. By analysing the salidroside and rosavin content and the electrophysiological activity in hippocampal long-term potentiation, a synaptic model of memory. Frontiers in Pharmacology 9: 425.PubMedPubMedCentralCrossRefGoogle Scholar
- 16.Crotti, A., C. Benner, B.E. Kerman, D. Gosselin, C. Lagier-Tourenne, C. Zuccato, E. Cattaneo, F.H. Gage, D.W. Cleveland, and C.K. Glass. 2014. Mutant Huntingtin promotes autonomous microglia activation via myeloid lineage-determining factors. Nature Neuroscience 17 (4): 513–521.PubMedPubMedCentralCrossRefGoogle Scholar
- 17.Horvath, R.J., N. Nutile-McMenemy, M.S. Alkaitis, and J.A. Deleo. 2008. Differential migration, LPS-induced cytokine, chemokine, and NO expression in immortalized BV-2 and HAPI cell lines and primary microglial cultures. Journal of Neurochemistry 107 (2): 557–569.PubMedPubMedCentralCrossRefGoogle Scholar
- 22.Defazio, G., M. Gelati, E. Corsini, B. Nico, A. Dufour, G. Massa, and A. Salmaggi. 2001. In vitro modulation of adhesion molecules, adhesion phenomena, and fluid phase endocytosis on human umbilical vein endothelial cells and brain-derived microvascular endothelium by IFN-beta 1a. Journal of Interferon & Cytokine Research 21 (5): 267–272.CrossRefGoogle Scholar
- 30.Ducruet, A.F., B.G. Hassid, W.J. Mack, S.A. Sosunov, M.L. Otten, D.J. Fusco, Z.L. Hickman, G.H. Kim, R.J. Komotar, J. Mocco, and E.S. Connolly. 2008. C3a receptor modulation of granulocyte infiltration after murine focal cerebral ischemia is reperfusion dependent. Journal of Cerebral Blood Flow and Metabolism 28 (5): 1048–1058.PubMedCrossRefPubMedCentralGoogle Scholar
- 32.Oh, H., B. Siano, and S. Diamond. 2008. Neutrophil isolation protocol. Journal of Visualized Experiments 17: 745.Google Scholar
- 42.Zhao, D., X. Sun, S. Lv, M. Sun, H. Guo, Y. Zhai, Z. Wang, P. Dai, L. Zheng, M. Ye, and X. Wang. 2019. Salidroside attenuates oxidized low-density lipoprotein-induced endothelial cell injury via promotion of the AMPK/SIRT1 pathway. International Journal of Molecular Medicine 43 (6): 2279–2290.PubMedPubMedCentralGoogle Scholar