Thymosin β4 for the treatment of acute stroke: neurorestorative or neuroprotective?

INTRODUCTION: Thymosin β4 (Tβ4) is a 5K peptide which influences cellular migration by inhibiting organization of the actin-cytoskeleton. Treatment of acute stroke presently involves use of rt-PA and/or endovascular treatment with thrombectomy, both of which have time limitations. Therefore, development of a treatment beyond these times is necessary as most stroke patients present beyond these time limits. A drug which could be administered within 24 h from symptom onset would provide substantial benefit. AREAS COVERED: This review summarizes the data and results of two in-vivo studies testing Tβ4 in an embolic stroke model of young and aged rats. In addition, we describe in-vitro investigations of the neurorestorative and neuroprotective properties of Tβ4 in a variety of neuroprogenitor and oligoprogenitor cell models. EXPERT OPINION: Tβ4 acts as a neurorestorative agent when employed in a young male rat model of embolic stroke while in an aged model it acts a neuroprotectant. However evaluation of Tβ4 as a treatment of stroke requires further preclinical evaluation in females and in males and females with comorbidities such as, hypertension and diabetes in models of embolic stroke to further define the mechanism of action and potential as a treatment of stroke in humans.