Current advances in ischemic stroke research and therapies

Abstract

With more than 795,000 cases occurring every year, stroke has become a major problem in the United States across all demographics. Stroke is the leading cause of long-term disability and is the fifth leading cause of death in the US. Ischemic stroke represents 87% of total strokes in the US, and is currently the main focus of stroke research. This literature review examines the risk factors associated with ischemic stroke, changes in cell morphology and signaling in the brain after stroke, and the advantages and disadvantages of in vivo and in vitro ischemic stroke models. Classification systems for stroke etiology are also discussed briefly, as well as current ischemic stroke therapies and new therapeutic strategies that focus on the potential of stem cells to promote stroke recovery.

Keywords: Dental pulp stem cells; Hematopoietic stem cells; Ischemic stroke; MCAO; Photothrombotic model; Regenerative therapy; Tissue plasminogen activator.

Figure 1.

Two intraluminal filament methods can be used to achieve middle cerebral artery occlusion The Longa method (right) has been deemed more useful for stroke research than the Koizumi method (left). The Longa method sees a much lower mortality rate post-surgery than that of the Koizumi. In the Longa method, the filament is inserted in the external carotid artery and is guided through the internal carotid artery to the middle cerebral artery, as opposed to insertion from the common carotid artery as seen in the Koizumi method.

Figure 2.

A. Summary of stroke generation using Rose Bengal Dye. B. Stepwise depiction of stroke generation at molecular and cellular levels.

Figure 3.

Stepwise summary of the intrinsic pathway of the coagulation cascade.

Figure 4.

A. Liposomes can be loaded with drugs to be delivered to the brain. B. Delivery of drug-loaded liposomes is impossible when the blood-brain barrier is intact. C. When the blood-brain barrier is compromised (such as after a stroke), liposomes can be used to deliver neuroprotective drugs to the tissue surrounding the vessel.

Figure 5.

A. Scanning electron micrograph of nanofiber expanded CD34⁺ hematopoietic stem cells. B. Scanning electron micrograph of neural cells differentiated from nanofiber expanded CD34⁺ hematopoietic stem cells. C. Serial images of brain taken with magnetic resonance imaging machine after middle cerebral artery occlusion-mediated stroke generated in non-obese diabetic/severe combined immunodeficient mice.