Ganglioside exogenous

Simons, M., Friedrichson, T., Schulz, J.B., Pitto, M., Masserini, M., and Kurzchalia, T.V. (1999) Exogenous administration of gangliosides displaces GPI-anchored proteins from lipid microdomains in living cells. Mol. Biol. Cell 10, 3187-3196. 

Little is known about the function of gangliosides. Gangliosides may serve as cell surface receptors (45) and as biotransducers of membrane-mediated information ). The ganglioside GM1 has been implicated as the receptor for choleragen. Our studies clearly indicate that butyrate induces toxin receptors and GM1 in parallel. In addition, the toxin receptors induced by butyrate are functionally indistinguishable from exogenous GM1 that has been absorbed by the cells. We believe that these observations are the quintessential evidence that GM1 alone is the receptor for choleragen. 

Exogenous GM1 ganglioside can be incorporated into the cell membrane and then act as a functional receptor. This was first shown by Cuatrecasas (11) who observed an increased binding capacity and lipolytic responsiveness of fat cells which had been soaked in GM1. Using tritium-labelled GM1-ganglioside, Holmgren... 

Effects of Exogenously Added Gangliosides on In Vitro Assays of Cellular Immunity... 

The data presented in Table XII show the effects of exogenous gangliosides, liposomes, and liposomal-bound gangliosides when added at initiation of MLC and 48 and 96 hours later. The effects of gangliosides on MLC reactivity with respect to the time of addition were similar to the effects on Con-A reactivity. When added at the time of culture initiation, both gangliosides and liposomal-bound gangliosides resulted in maximal inhibition with less effect noted when added 48 hours and 96 hours later. 

It is now well established that ganglioside added to culture media can modulate lymphocyte reactivity Iri vitro. Previous studies demonstrated this phenomenon in murine systems(8,9,10), and the present studies show that human peripheral blood mononuclear cell responses to non-specific mitogens and allogeneic stimuli are similarly sensitive to exogenous gangliosides. In none of these systems does the effect appear to be due to a nonspecific toxic effect as cell viability and several biological phenomena remain intact(9). Furthermore, the degree of inhibition is dose dependent. 

Hadjiconstantinou, M., Weihmuller, F.B., Bruno, J.P., Mariani, A.P. and Neff, N.H. (1990) Recovery of dopaminergic function following MPTP-induced neurodegeneration by exogenous GMl ganglioside. In L.A. Horrocks (Ed.), Trophic Factors and the Nervous System, Raven Press, New York, pp. 293-305. 

The synaptosome fractions coming from the two crude mitochondrial fractions were, however, clearly different in their capacity to sialylate endogenous or exogenous gangliosides "in vitro". The... 

Since the discovery of gangliosides by Klenk in the first half of the twentieth century, considerable effort has been made to understand their functional role in the central nervous system. In 1961, Mcllwain reported that the addition of gangliosides could restore the lost electrical excitability of cortical slices kept at 0 C for 5 h. Similarly, the administration of gangliosides could prevent the deleterious effects of ethanol on nerve function. In cell cultures, exogenously added gangliosides could induce axonal sprouting and neurite outgrowth. " ... 

Cho, J. W., and Troy, F. A., 1989, Gangliosides as exogenous acceptors to map the acceptor sugar requirements of the poly-a2,8-sialyltransferase in Escherichia coli kl, Proc. Xth Int. Symp. Glycoconjugates, p. 143. 

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