title: Collateral blood flow in different cerebrovascular hierarchy provides endogenous protection in cerebral ischemia.
abstract: Collateral blood flow as vascular adaptions to focal cerebral ischemia is well recognized. However, few studies directly investigate the dynamics of collateral vessel recruitment in vivo and little is known about the effect of collateral blood flow in different cerebrovascular hierarchy on the neuropathology after focal ischemic stroke. Here, we report that collateral blood flow is critically involved in blood vessel compensations following regional ischemia. We occluded a pial arteriole using femtosecond laser ablating under the intact thinned skull and documented the changes of collateral flow around the surface communication network and between the surface communication network and subsurface microcirculation network using in vivo two photon microscopy imaging. Occlusion of the pial arteriole apparently increased the diameter and collateral blood flow of its leptomeningeal anastomoses, which significantly reduced the cortical infarction size. This result suggests that the collateral flow via surface communicating network connected with leptomeningeal anastomoses could greatly impact on the extent of infarction. We then further occluded the target pial arteriole and all of its leptomeningeal anastomoses. Notably, this type of occlusion led to reversals of blood flow in the penetrating arterioles mainly proximal to the occluded pial arteriole in a direction from the subsurface microcirculation network to surface arterioles. Interesting, the cell death in the area of ischemic penumbra was accelerated when we performed occlusion to cease the reversed blood flow in those penetrating arterioles, suggesting that the collateral blood flow from subsurface microcirculation network exerts protective roles in delaying cell death in the ischemic penumbra. In conclusion, we provide the first experimental evidence that collateral blood vessels at different cerebrovascular hierarchy are endogenously compensatory mechanisms in brain ischemia.
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors.forename: Chuanming
authors.initials: C
authors.lastname: Luo
authors.affiliation: Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, First Affiliated Hospital Sun Yat-Sen University, Guangzhou, 510080, China.
authors.forename: Fengyin
authors.initials: F
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors.forename: Huixia
authors.initials: H
authors.lastname: Ren
authors.affiliation: Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, First Affiliated Hospital Sun Yat-Sen University, Guangzhou, 510080, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, First Affiliated Hospital Sun Yat-Sen University, Guangzhou, 510080, China.
authors.forename: Mingyue
authors.initials: M
authors.lastname: Li
authors.affiliation: South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Dajiang
authors.initials: D
authors.lastname: Qin
authors.affiliation: School of Psychology, Nanjing Normal University, Nanjing, China.
authors.forename: Ti-Fei
authors.initials: TF
authors.lastname: Yuan
authors.affiliation: Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, First Affiliated Hospital Sun Yat-Sen University, Guangzhou, 510080, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Pei
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors.forename: Huanxing
authors.initials: H
authors.lastname: Su
mesh_terms: D000818:Animals; D001160:Arterioles; D001921:Brain / Q000503:physiopathology; D002545:Brain Ischemia / Q000097:blood / Q000473:pathology*; D002544:Cerebral Infarction / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D003097:Collateral Circulation / Q000502:physiology*; D004195:Disease Models, Animal; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D020521:Stroke / Q000473:pathology
keywords: collateral blood flow; endogenous protection; focal ischemia; leptomeningeal anastomoses; microcirculation; two-photon microscopys