The Anti-apoptotic Effect On PC12 Cells Induced By Ganglioside GM1

Parkinson's disease (PD) is one of the most common degenerative disorders of central neural system, which is characterized by a selective loss of dopaminergic neurons in the mesencephalic nigrostriatal projection, The decrease of the neurotransmitter of dopamine lead to various clinical symptoms such as tremor, rigidity, akinesia and so on. Oral administration of L-dopa continues to be the mainstay of current therapy for PD, but is limited by the inability to prevent the progressive degeneration of dopamine-secreting nerve cells. Ganglioside GM1 is a normal constituent of mammalian vertebrate cell membranes, which could protect the neural tissue from damage and promote its regeneration.OBJECTIVETo explore the mechanism of the protective effect of the ganglioside GM1 in the treatment of Parkinson's disease. The rat pheochromocytoma PC 12 cells as a catecholaminergic lines are widely used in the death pattern of neurons because it has the similar receptors and transmitters in the dopaminergic neurons.Gangliosides are normal constituent of mammalian vertebrate cell membranes and are particularly abundant in the central and peripheral nervous systems. The biological effects have been investigated in vitro and in experimental animal models and proved that they have neuronotrophic and neuritogenic properties. In this study, we build this apoptotic cellular model with PC 12 cells treated with L-dopa, using the flow cytometry, electron microscope and immuno-histochemica! technology to observer whether the GM1 could protect the PC12 cells from apoptosis.METHODS1.Using the electron microscope and microscope, we observed the alteration of structure, ultrastructure and biochemistry on PC 12 cells with different concentration of ganglioside GM1 in different time.2.Using the flow cytometry and electrophoreiss technology, we observed the effect of ganglioside GM1 on PC 12 cells with different concentration in different period induced by L-dopa, to find the death pattern of cell and to study the relationship between apotosis and the dosage of ganglioside GM1 in different time.3.Using the Immunohistochemical technology, we observed the expression of anti-apoptosis protein (Bcl-2) and proapoptotic protein (Bax), and the relationships between these protein expression and apoptosis.RESULTSl.When PC 12 cells were treated with L-DOPA for 24h, Some apoptotic morphological features, such as volume reduction, chromatin condensation and apoptotic bodies can be found under light microscope and electron microscope. Necroses were also found when the stimulation went on. PC 12 cells treated with ganglioside GM1 have less apoptotic morphological features than the group above.2.Using the flow cytometry to observe the cellular life circle and death rate, we can find that the group treated with ganglioside GM1 has lower death rate than the L-dopa treated group and this shows dose-dependent manner3.The results of electrophoresis shows a typical DNA Madder' fragment which means the occurrence of apoptosis in the L-dopa treated group and the ganglioside GM1 treated group has less DNA Madder'.4.The expression of Bcl-2 and Bax protein had been found when PC 12 cells were treated with L-dopa only. The Bcl-2 protein which can prevent apoptosis had a top peak expression in 12h, then decrease rapidly. The Bax protein which induces apoptosis had a top peak expression in 6h, then decrease greatly. The ratio of Bcl-2 to Bax can decides the process of apotosis. The ganglioside GM1 used here can prevent the expression of Bax protein. Such effect also shows dose dependent manner.CONCLUSIONSl.The findings of this study demonstrate that GM1 could protect the PCI2 cells from apoptosis and show a dose dependent effect. The main reason for this may be that the ganglioside GM1 can break up the apoptotic pathway.2. This study proved that ganglioside GM1 could protect the PC 12 cells from apoptosis with the change of morphological features. The results of the flow cytometry and the electrophoreiss also identi...