Inflammation after Ischemic Stroke: The Role of Leukocytes and Glial Cells

Abstract

The immune response after stroke is known to play a major role in ischemic brain pathobiology. The inflammatory signals released by immune mediators activated by brain injury sets off a complex series of biochemical and molecular events which have been increasingly recognized as a key contributor to neuronal cell death. The primary immune mediators involved are glial cells and infiltrating leukocytes, including neutrophils, monocytes and lymphocyte. After ischemic stroke, activation of glial cells and subsequent release of pro- and anti-inflammatory signals are important for modulating both neuronal cell damage and wound healing. Infiltrated leukocytes release inflammatory mediators into the site of the lesion, thereby exacerbating brain injury. This review describes how the roles of glial cells and circulating leukocytes are a double-edged sword for neuroinflammation by focusing on their detrimental and protective effects in ischemic stroke. Here, we will focus on underlying characterize of glial cells and leukocytes under inflammation after ischemic stroke.

Role of neuroinflammation in ischemic stroke

“…[37] Astrocyte is important mediator of homeostasis in the brain. [38] These two cells are key players in the multicellular response to central nervous system (CNS) trauma and disease, including the immune reactions. [39,40] TLRs, the well-defined pattern recognition receptors of the immune system, [41] can initiate an immune response upon exposure to harmful microorganisms [42] and play a key role in macrophage activation.…”

“…[72] Ischemia-induced cell debris and increased ROS lead to neuroinflammation by activating resident microglia and astrocytes as well as attracting infiltrating leukocytes from circulating blood. [73] These cells increase major histocompatibility complex class II molecules and cytokines. [74][75][76] Following activation of microglia, the release of pro-inflammatory mediators from these microglia favor the permeability of the BBB.…”

Neutrophil to Lymphocyte Ratio Predicts Short-Term Functional Outcome in Acute Ischemic Stroke

“…Elevated blood inflammatory markers such as high sensitivity C-reactive protein (hs-CRP) have been shown to be independent risk factors for cardiovascular disease and ischemic stroke [2,3]. Recently, there have been reports of leukocytes having a similar role in ischemic events [4,5].…”

“…Inflammatory cascade following acute ischemic stroke (AIS) is an important pathological process in damaged brain tissue [4,5]. The inflammatory process in AIS involves cytokines and chemokines released from ischemic tissues, promoting the accumulation of leukocytes to the ischemic areas [5,6].…”

“…The inflammatory process in AIS involves cytokines and chemokines released from ischemic tissues, promoting the accumulation of leukocytes to the ischemic areas [5,6]. Among circulating leukocytes, neutrophils have been regarded as crucial mediators of ischemic injury [6][7][8].…”