The combination of stem cell factor and granulocyte-colony stimulating factor for chronic stroke treatment in aged animals

Cortical brain ischemia was produced in aged C57BL mice or aged spontaneously hypertensive rats. SCF+G-CSF or equal volume of vehicle solution was subcutaneously injected for 7 days beginning at 3–4 months after induction of cortical brain ischemia. Using the approaches of biochemistry assays, flow cytometry, pathology, and evaluation of functional outcome, several doses of SCF+G-CSF have been examined for their safety and efficiency on chronic stroke in aged animals.All tested doses did not show acute or chronic toxicity in the aged animals. Additionally, SCF+G-CSF treatment in chronic stroke of aged animals mobilized bone marrow stem cells and improved functional outcome in a dose-dependent manner.SCF+G-CSF treatment is a safe and effective approach to chronic stroke in the aged condition. This study provides important information needed for developing a new therapeutic strategy to improve the health of older adults with chronic stroke.Stroke is a cerebrovascular disease with the highest incidence occurring in those over the age of 60 [1]. Stroke also presents the number one cause of long-term disability in adults worldwide. A stroke is classified into 3 phases based on the pathological progression and timing after stroke onset: the acute phase, the subacute phase and chronic phase. The time frame of the three phases may be different for the individuals according to the location and the size of the infarction, the pathogenesis, cerebral vasculature response, and the age of the patients. Generally, acute stroke is the first 48 h after stroke onset, subacute stroke is 48 h to six weeks or to three months post-stroke, whereas chronic stroke is beyond three to six months after stroke onset.Treatment for stroke is not well developed. Recombinant tissue plasminogen activator (rtPA) is the only US Food and Drug Administration-approved drug for treatment of ischemic stroke patients in the acute phase [2]. This thrombolytic therapy must be initiated within 4.5 h of stroke