NEURONAL THREAD PROTEIN GENE MODULATION WITH CEREBRAL INFARCTION

Neuronal thread proteins (NTP) are a family of phosphoproteins express ed during neuritic sprouting. The 15 to 18 kD NTP cluster is associate d with development and neuronal differentiation, whereas the 21 kD and 39 to 42 kD species are overexpressed in Alzheimer's disease, correla ting with neurodegenerative sprouting and synaptic disconnection. Empi rical observations suggested that NTP might also be modulated with cen tral nervous system injury and stroke. In this study of both human and experimental (rat) focal cerebral infarcts, in situ hybridization and immunocytochemical staining revealed NTP gene expression up-regulated in perifocal neurons. These findings were confirmed by quantitative N orthern and Western blot analyses. Moreover, Western blot analysis dem onstrated selectively increased expression of the 15 to 18 kD NTP spec ies during the acute, subacute, and healing phases of cerebral infarct ion in both humans and experimental animals, cone spending with the ex pected period of neuronal repair. These results suggest an additional role for the 15 to 18 kD NTP species in neuritic sprouting required fo r neuronal regeneration after injury in the mature central nervous sys tem.