Nerve growth factor-mediated expression of galectin-3 in mouse dorsal root ganglion neurons.

Galectin-3, a member of the galectin family of beta-galactoside-specific lectins has been found to be expressed by subsets of dorsal root ganglion (DRG) neurons during development and in adulthood. Here we show that (i) after 3-7 days in vitro, DRG neurons derived from neonatal mice express galectin-3 intra- and extracellularly and (ii) lectin expression requires the presence of nerve growth factor (NGF). After 3 days in vitro, a higher number of DRG neurons expressed galectin-3 in the presence of NGF (65 +/- 7%) than in the presence of brain-derived neurotrophic factor (BDNF, 30 +/- 3%) or neurotrophin-3 (NT-3, 34 +/- 3%). After 7 days in vitro, these numbers dropped to 51 +/- 3% (for NGF), 0% (for BDNF) and 8 +/- 4% (for NT-3), respectively. Our findings provide first evidence for the contribution of a neurotrophin to the neuronal expression of galectins and suggest an NGF/TrkA-mediated expression of galectin-3 by early postnatal DRG neurons.