Researchers at the National Center of Neurology and Psychiatry (NCNP), Osaka University, University of Tsukuba and others have elucidated the mechanism by which the repair power of the neural circuit of the brain that has deteriorated due to aging is restored.
The neural circuits of the brain and spinal cord have the power to repair naturally even if they are damaged by various cerebrospinal diseases.However, the ability to repair neural circuits deteriorates with age, and it gradually becomes impossible to repair.
On the other hand, the structure called "myelin sheath" that constitutes the neural circuit of the brain and spinal cord is said to play an important role in exerting nerve function, and the loss of the myelin sheath is observed as a lesion of various diseases of the brain and spinal cord. ..Oligodendrocyte progenitor cells need to be differentiated to repair the myelin sheath, but with aging, the ability of oligodendrocytes to differentiate decreases, making it difficult to differentiate spontaneously.
Against this background, the group investigated molecular expression in oligodendrocytes in experiments using mice.As a result, it was found that the molecule called APJ receptor is abundantly expressed in oligodendrocytes under the condition that the myelin sheath is easily repaired.On the contrary, it was found that in mice lacking the APJ receptor expressed in oligodendrocytes, myelin sheath formation and poor motor function were remarkable.
Therefore, further experiments were conducted using aged mice, and the amount of apelin, which is a bioactive peptide in the body, was decreased in the aged mice, and the repair of the damaged myelin sheath was promoted by the APJ receptor activator. I found out.In experiments using cultured cells, it was confirmed that activation of APJ receptors also promotes differentiation of human oligodendrocytes.
Myelin sheath shedding is also a feature of multiple sclerosis lesions, a designated intractable disease.This result indicates that activation of APJ receptors improves the repair ability of the myelin sheath, and may be effective in improving brain function in the elderly and treating diseases with myelin sheath injury.
Paper information:[Nature Aging] Age-dependent decline in remyelination capacity is mediated by apelin–APJ signaling