title: Diverse Functions and Mechanisms of Pericytes in Ischemic Stroke.
abstract: BACKGROUND
  Every year, strokes take millions of lives and leave millions of individuals living with permanent disabilities. Recently more researchers embrace the concept of the neurovascular unit (NVU), which encompasses neurons, endothelial cells (ECs), pericytes, astrocyte, microglia, and the extracellular matrix. It has been well-documented that NVU emerged as a new paradigm for the exploration of mechanisms and therapies in ischemic stroke. To better understand the complex NVU and broaden therapeutic targets, we must probe the roles of multiple cell types in ischemic stroke. The aims of this paper are to introduce the biological characteristics of brain pericytes and the available evidence on the diverse functions and mechanisms involving the pericytes in the context of ischemic stroke.
  
  
  METHODS
  Research and online content related to the biological characteristics and pathophysiological roles of pericytes is review. The new research direction on the Pericytes in ischemic stroke, and the potential therapeutic targets are provided.
  
  
  RESULTS
  During the different stages of ischemic stroke, pericytes play different roles: 1) On the hyperacute phase of stroke, pericytes constriction and death may be a cause of the no-reflow phenomenon in brain capillaries; 2) During the acute phase, pericytes detach from microvessels and participate in inflammatory-immunological response, resulting in the BBB damage and brain edema. Pericytes also provide benefit for neuroprotection by protecting endothelium, stabilizing BBB and releasing neurotrophins; 3) Similarly, during the later recovery phase of stroke, pericytes also contribute to angiogenesis, neurogenesis, and thereby promote neurological recovery.
  
  
  CONCLUSIONS
  This emphasis on the NVU concept has shifted the focus of ischemic stroke research from neuro-centric views to the complex interactions within NVU. With this new perspective, pericytes that are centrally positioned in the NVU have been widely studied in ischemic stroke. More work is needed to elucidate the beneficial and detrimental roles of brain pericytes in ischemic stroke that may serve as a basis for potential therapeutic targets.
authors.affiliation: Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Huijuan
authors.initials: H
authors.lastname: Jin
authors.affiliation: Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wan
authors.affiliation: Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Elvis Nana
authors.initials: EN
authors.lastname: Opoku
authors.affiliation: Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Lingqiang
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000503:physiopathology; D002545:Brain Ischemia / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D020286:Pericytes / Q000502:physiology* / Q000648:ultrastructure; D020521:Stroke / Q000188:drug therapy / Q000503:physiopathology*
keywords: BBB; NVU; Pericytes; ischemic stroke; mechanisms; therapeutic targets