Transplantation of adipose-derived stem cells in stroke

Abstract

Not only is stroke second only to cardiac ischemia as a leading cause of death worldwide, but it also drastically impaired the quality of life of the survivors through its crippling neurological sequelae which account for the third leading cause of disability. Instead of merely a loss of functioning neurons from ischemia, stroke triggers a cascade of adverse events including inflammation, oxidative stress, and apoptosis that perpetuates the initial ischemic damage. Current therapeutic strategies, including the use of thrombolytic agents and other non-pharmaceutical approaches, have their limitations either because of the risk of complications or focusing only on the prevention of brain damage and rehabilitation. More importantly, none has been convincingly shown to improve neurological outcome in patients with stroke once the brain tissue is infarcted. Accumulating evidence has indicated that, instead of being only neuroprotective, stem cells actually possess neurorestorative function for promoting recovery of the injured brain tissue. Accordingly, cell transplant therapy with adipose-derived mesenchymal stem cells (ADSC) has recently emerged as a potentially feasible therapeutic option not only because of their abundance and relative ease of being harvested, but also because of the possibility of autologous implantation and their demonstrated multiple beneficial biological actions against stroke in experimental settings, namely paracrine effects, transdifferentiation, and immunomodulation, that could enhance brain plasticity such as neurogenesis, remyelination, synaptogenesis, and angiogenesis in the recovery process. The nature and source of ADSC as well as their demonstrated therapeutic potential against stroke, the clinical perspective in stroke treatment, and the potential risks are reviewed.