Expression of beta-synuclein in normal human astrocytes

Although alpha- and beta -synucleins are expressed predominantly in presyna ptic nerve terminals, recent studies have demonstrated that alpha -synuclei n is also expressed in cultured astrocytes and oligodendrocytes. We determi ned whether alpha -synuclein might be expressed in astrocytes. alpha -Synuc lein mRNA and protein were detected in normal human astrocytes in culture, and immunofluorescent staining showed that beta -synuclein protein was expr essed within the cytoplasm and nucleus. Furthermore, beta -synuclein immuno reactivity was present in astrocytes, but not in oligodendrocytes, in norma l human brain tissues. Ultrastructurally, beta -synuclein immunoreactivity was found in the cytoplasm of astrocytes, in association with the plasma me mbrane, ribosomes, rough endoplasmic reticulum and the nuclear outer membra ne. The novel expression of beta -synuclein in astrocytes may provide an im portant insight about the role of this protein. NeuroReport 12:2845-2848 (C ) 2001 Lippincott Williams & Wilkins.