Ischemic stroke and neurovascular unit: How do they associate?
Dr Md Anawar Hossain
Ischemic stroke and its effect
Stroke is the second leading factor for people’s death worldwide. It also causes the disability of people. Ischemic stroke (IS) is a common cerebrovascular disease which accounts for 85% of strokes (Wang et al., 2021). A sudden blockage of a blood vessel in the brain restricts blood supply to the brain cell, causes the death of brain cells and makes a significantly negative impact on human health and society. The large scale neuroprotective clinical trials were conducted for the last few decades, but most of them failed. Therefore, the focus of stroke treatment shifted from a neuroprotective approach to neurovascular protection.
Treatment options and new development
The concept of the neurovascular unit (NVU) consists of neurons, astrocytes, smooth muscle cells (SMCs), endothelial cells (ECs), pericytes (PCs), and the basal lamina matrix (Wang et al., 2021). It plays a significant role in ischemic stroke progression. Effective reperfusion strategies are implemented to restore the blood flow in the target organ or tissue after stroke or heart attack. The intravenous thrombolysis and thrombectomy are the most common treatment options for ischemic stroke patients. Currently, the tissue-type plasminogen activator (tPA) is a widely accepted treatment, that is the most effective when administered within 4.5 h after acute ischemic stroke (AIS). However, tissue-type plasminogen activator treatment is administered to a limited number of patients due to its time restriction. Therefore, there is an urgent need to develop other effective treatments.
Impact of neurovascular unit on ischemic stroke treatment
The current treatment methods use the recanalization of occluded blood vessels, which are insufficient or inaccessible to many stroke patients. Recently, we can more clearly understand about the profound influence of the neurovascular unit on recanalization and the prognosis of ischemic stroke. Deeper studies of the neurovascular unit have also provided novel approaches for ischemic stroke treatment (Wang et al., 2021). Wang et al. (2021) reported that both the pathophysiological and neurovascular repair processes of ischemic stroke are strongly associated with the homeostatic state of the neurovascular unit. Therefore, further research into therapies focusing on the neurovascular unit could develop more treatment options for ischemic stroke. Wang et al. (2021) made a thorough review and provided some conclusions for the effects of neurovascular unit on the current and future development of therapies for ischemic stroke as below:
- Definitely, the neurovascular unit has a significant leading role in the pathophysiological process of ischemic stroke.
- Neurovascular unit may have great effects on the blood-brain barrier (BBB), cell preservation, inflammatory immune response, and neurovascular repair.
- Both cell-based and pharmacological treatments targeting the neurovascular unit can act or fight against detrimental effects or injuries after an ischemic stroke.
- The idea of ischemic stroke treatment has shifted from the neuronal era to the neurovascular era.
- The entire framework of the neurovascular unit must be considered to conduct thorough investigations on the multiple interactions between its cells to further explore the therapeutic potential of the neurovascular unit in clinical settings.
Reference
Wang L., Xiong X., Zhang L., Shen J., 2021. Neurovascular Unit: A critical role in ischemic stroke. CNS Neuroscience & Therapeutics, Vol. 27, pp. 7–16.