Ischemia, reactive radicals, redox signaling and hematopoietic stem cells

Ischemia is a medical condition generated by inadequate or no blood flow to the organs such as heart, brain, limbs and kidney, contributes to the pathophysiology of several diseases such as myocardial infarction, cerebral ischemia (stroke), peripheral vascular insufficiency and hypovolemic shock etc. As a result of ischemic insult, cascades of metabolic and ultra structural changes occur at the cellular level resulted in irreversible tissue injury and cell death. Several pharmacological interventions such as antioxidant therapy, anti-inflammatory therapy along with reperfusion strategies have been tried for several decades to protect the affected tissue from necrosis and cell death after ischemic insult. But, none of these interventions had proven to be cure for ischemia. Thus, novel therapeutic approach such as stem cell becomes very popular in the field of regenerative medicine to treat post ischemic conditions and to improve patient lifestyle as an alternate. Hematopoietic stem and progenitor cells from different sources showed promise to the ischemic therapy. Human umbilical cord blood-derived stem cells are one of the most promising cells that have shown beneficial effects in treating ischemic disorders in pre-clinical models and some clinical trials. However, several hurdles such as adequate supply of stem cells, suitable route of administration, need to be addressed to use as a regular therapeutic regiment for ischemic patients in the clinic.