Japan Team Finds Substance to Help Keep Post-Stroke Recovery

Tokyo, May 14 (Jiji Press)–A team including Takashi Shichita, a professor at the Institute of Science Tokyo’s Medical Research Laboratory, has developed a drug candidate to suppress a type of protein that causes the rehabilitation-induced partial recovery of motor functions lost from a stroke to end after only about two months. People who lost the abilities to move their hands or feet, or to speak due to the deaths of some nerve cells in their brains from the cerebral infarction can regain the functions to a certain extent through rehabilitation. The recovery normally lasts for about two months. The recovery is possible because surviving nerve cells repair the neuron networks, with microglia, or cells in charge of brain immunity, helping the restoration process by secreting a protein called insulin-like growth factor 1, or IGF1. In a genetic manipulation experiment using mice, Shichita and other members of the team discovered that microglia stopped secreting IGF1 after a while following a stroke due to the function of another protein, ZFP384. The same mechanism was confirmed in the brains of dead stroke patients. The team developed the drug candidate to block the production of ZFP384. After injecting the drug into mice, the team found that microglia continued to secrete IGF1 and helped maintain the recovery of brain functions. The drug is a type of antisense oligonucleotide, or ASO, that binds to messenger RNA, or mRNA, from the ZFP384 gene and helps break down the protein. ASO therapy is starting to be used to treat intractable neurological disorders. Shichita said that the drug candidate still needs to be tweaked to further enhance its efficacy for human use. “We will work hard toward delivering the drug to patients in 10-20 years,” Shichita said. The team’s findings were published on the online edition of British scientific journal Nature on Wednesday. END [Copyright The Jiji Press, Ltd.]