M. Gleichmann et al., Cloning and characterization of SDF-1 gamma a novel SDF-1 chemokine transcript with developmentally regulated expression in the nervous system, EUR J NEURO, 12(6), 2000, pp. 1857-1866
The cytokines SDF-1 alpha and -1 beta are two alternatively spliced variant
s of the CXC (alpha) chemokines that are highly conserved among species. SD
F-1 alpha was shown to function as a B-cell maturation factor, a ligand for
the CXCR4 (LESTR/fusin) chemokine receptor, thereby inhibiting replication
of T cell-tropic HIV-1 strains and inducing cell death in human neuronal c
ell lines. In this report the cloning of the rat SDF-1 beta cDNA and a new
SDF-1 isoform, SDF-1 gamma, are presented. Using Northern blot analysis, th
e expression pattern of both isoforms was studied in different tissues and
it is shown that during postnatal development of the central and peripheral
nervous system SDF-1 beta- and SDF-1 gamma-mRNA expression is inversely re
gulated. Whilst SDF-1 beta-mRNA is the predominant isoform in embryonic and
early postnatal nerve tissue, SDF-1 gamma-mRNA is expressed at higher leve
ls in adulthood. After peripheral nerve lesion a transient increase in SDF-
1 beta-mRNA expression is observed. As revealed by in situ hybridization, n
eurons and Schwann cells are the main cellular sources of both SDF-1 beta a
nd SDF-1 gamma mRNAs in the nervous system. Computer-assisted analysis reve
aled that both transcripts encode secreted peptides with putative proteolyt
ic cleavage sites which might generate novel neuropeptides.