PURPOSE: An agent containing thymosin beta 4 for suppressing or treating nerve cell injury is provided to reduce nerve cell apoptosis and to suppress inflammation. CONSTITUTION: A composition for suppressing or treating nerve cell injury associated to diseases caused by cerebral blood flow contains thymosin beta 4 protein or nucleic acid encoding the same. The thymosin beta 4 protein or nucleic acid is derived from human. The diseases caused by cerebral blood flow are cerebral ischemia or dementia. A transformed animal model except for human contains the thymosin beta 4 gene. The animal model is a mouse. A method for selecting a marker for diagnosing or treating diseases caused by cerebral blood flow reduction using the animal model which expresses thymosin beta 4 comprises: a step of inducing ischemic brain injury to the animal model and healthy animal； a step of extracting brain tissue from each animal predetermined time later, in which ischemic brain injury is induced； and a step of extracting RNA or protein from the brain tissue.본 발명은 티모신 베타 4 또는 이를 코딩하는 핵산을 포함하는 뇌혈류량 감소로 인한 질환과 연관된 신경세포 손상 억제 또는 치료제를 제공한다. 또한 본 발명은 티모신 베타 4를 발현하는 동물모델 및 상기 동물 모델을 이용한 신경세포 손상에 대한 치료 또는 진단 마커 선별 방법을 제공한다.
