Transplantations and Cloning of an Immortal Cell Line from Rat SCN.

摘要

Primary cells from the anlagen of the rat suprachiasmatic nucleus (SCN) have been immortalized by infection with a retroviral vector encoding the adenovirus E1A oncogene. The resulting neural cell lines (SCN1.4 and 2.2) are characterized by extended growth potential without neoplastic activity, uniform nuclear expression of ElA protein and heterogeneous cell types in various stages of differentiation. The SCN1.4 and SCN2.2 lines exhibit many cells with glial morphologies and a small, stable population of cells with neuronal characteristics. Differentiated neuron-like cells are distinguished by fine processes and immunostaining for neuronal markers and peptides found within SCN neurons in situ. Concordant with immunostaining data, content, release and mRNA expression of SCN neuropeptides in both lines followed a distinct pattern with somatostatin and vasopressin cells representing the most and least common peptidergic phenotypes, respectively. Since E1A-immortalized cells from the primordial SCN can differentiate into neurons with mature, parental-like phenotypes, the initial project objective was to determine whether the lines also retain the distinctive function of the SCN to generate circadian rhythms. Circadian wheel-running activity was restored in approx. 40% of SCN-lesioned hamsters following transplantation of immortalized cells, suggesting that circadian timekeeping may be a stable functional property of these lines. The project has also yielded clonal lines of immortalized cells that exhibit specific SCN phenotypes and may provide models for studying the regulation of neuropeptide gene expression and the role of peptidergic cells in mammalian circadian timekeeping. Circadian rhythms, Biological clock, Oscillation, Suprachiasmatic nucleus, Im.