Galectin-3 promotes neural cell adhesion and neurite growth

Abstract

Galectin-3 is a member of the galectin family and belongs to a group of soluble beta-galactoside-binding animal lectins. The molecule is expressed by neural and nonneural cells intra- (cytoplasm and nucleus) as well as extra-cellularly (plasma membrane and extracellular space). By using an in vitro cell-substratum adhesion assay, we have addressed the question whether galectin-3 present in the extracellular milieu may support the adhesion and/or neurite outgrowth of neural cells in a manner analogous to cell adhesion molecules. Galectin-3 was immobilized as a substratum and various cell types, N2A (neuroblastoma), PC12 (pheochromocytoma), and TSC (transformed Schwann cells) cell lines, neural cells from early postnatal mouse cerebellum, and dorsal root ganglion neurons from newborn mice were allowed to adhere to the lectin. Here we show that all cell types studied specifically adhered to galectin-3 by the following criteria: 1) the number of adherent cells was dependent on the galectin-3 concentration used for coating; 2) adhesion of cells to galectin-3, but not to collagen type I or laminin was inhibited by polyclonal antibodies to galectin-3; 3) upon addition of asialofetuin (a polyvalent carrier of terminal beta-galactosides) to the cell suspension prior to the adhesion assay, cell adhesion to galectin-3 was inhibited in a dose-dependent manner; and 4) cell adhesion to galectin-3 was abolished by treatment of cells with endo-beta-galactosidase. In addition, the adhesion of dorsal root ganglion neurons to galectin-3 could be inhibited by lactose. Notably, substratum-bound galectin-3 promoted the outgrowth of neurites from dorsal root ganglia explants and this neurite outgrowth promoting activity could be inhibited by polyclonal antibodies to galectin-3.

Galectin-1 and Galectin-3 in Chronic Pancreatitis

“…Galectin-1 and its laminin ligand have been implicated in the growth of primary sensory olfactory axons arising from the olfactory neuroepithelium that lines the nasal cavity and then projects, via the olfactory nerve, into the olfactory bulb (TenneBrown et al, 1998). Furthermore, galectin-3 influences cell growth and repair in the nervous system by promoting neural cell adhesion and neurite growth (Pesheva et al, 1998). It is expressed in the developing notochord of embryonic mice, and in the dorsal root ganglion of rats with peripheral nerve injury (Cameron et al, 1993;Fowlis et al, 1995).…”

Proteomic Analysis of Dendritic Cell-Derived Exosomes: A Secreted Subcellular Compartment Distinct from Apoptotic Vesicles

“…All these proteins could be involved in budding of vesicles from the external membrane of the multivesicular endosome to form the exosomes and/or in fusion of these compartments with the plasma membrane that result in exosome secretion. Interestingly, two cytosolic proteins found in exosomes have been described in the extracellular environment: galectin-3, which modulates cell interaction with laminin (50,51), and annexin II (52). These proteins do not bear a signal sequence responsible for secretion through the constitutive pathway; it would therefore be interesting to determine whether exosomes represent an unconventional secretion pathway for some proteins (53).…”

Galectin-3 maintains cell motility from the subventricular zone to the olfactory bulb

“…Although we do not believe it is likely, it is possible that widths of GFAP immunoreactivity increased without the entire process thickening. Gal-3 promotes process outgrowth in dorsal root ganglion neurons (Pesheva et al, 1998) and axonal branching in hippocampal neurons (Diez-Revuelta et al, 2010), suggesting that it regulates morphology in a variety of neural cells. Disrupted SVZ and RMS astrocytic cytoarchitecture has been associated with abnormal migration in Bax-null mice and ErbB4 mutants (Ghashghaei et al, 2006).…”