Related Experiment Videos
Plasminogen promotes the development of rat mesencephalic dopaminergic neurons in vitro
K Nagata1, K Nakajima, S Kohsaka
1Department of Neurochemistry, National Institute of Neuroscience, Tokyo, Japan.
Abstract:
In order to investigate the physiological significance of plasminogen, which is produced by and secreted from microglia, we determined the effects of plasminogen on the development of primary cultured mesencephalic neurons from 16-day-old embryonic rats. Plasminogen markedly increased dopamine uptake and the dopamine content of cultured neurons. Furthermore, the number of mesencephalic dopaminergic neurons, which was determined by immunostaining with tyrosine hydroxylase antibody, was significantly increased in the presence of plasminogen. However, plasminogen had only a slight effect on gamma-aminobutyric acid (GABA) uptake and glutamic acid decarboxylase activity in mesencephalic neurons. The effect on dopaminergic neurons was also observed in the culture in the presence of cytosine arabinoside. In addition, plasminogen had no effect on the number of glial fibrillary acidic protein-positive cells. These results suggest that plasminogen acts directly on neurons and enhances the development of dopaminergic neurons in a rather selective manner.
Insights
Microglia-secreted plasminogen significantly enhances dopaminergic neuron development and dopamine uptake in developing neurons. This suggests plasminogen plays a key role in promoting the growth of these vital brain cells.
Area of Science:
- Neuroscience
- Cell Biology
- Biochemistry
Background:
- Microglia produce and secrete plasminogen.
- The physiological role of microglial plasminogen in neuronal development is not well understood.
Purpose of the Study:
- To investigate the effects of plasminogen on the development of primary cultured mesencephalic neurons.
- To determine if plasminogen selectively influences dopaminergic neuron development.
Main Methods:
- Primary mesencephalic neurons from embryonic rats were cultured with and without plasminogen.
- Dopamine uptake and content were measured.
- Dopaminergic neuron numbers were quantified using tyrosine hydroxylase immunostaining.
- Gamma-aminobutyric acid (GABA) uptake and glutamic acid decarboxylase activity were assessed.
- Effects on glial cells were evaluated using glial fibrillary acidic protein staining.
Main Results:
- Plasminogen significantly increased dopamine uptake and dopamine content in cultured neurons.
- The number of dopaminergic neurons was significantly elevated in the presence of plasminogen.
- Plasminogen had minimal effects on GABA uptake and glutamic acid decarboxylase activity.
- Plasminogen did not affect the number of glial fibrillary acidic protein-positive cells.
Conclusions:
- Plasminogen directly and selectively enhances the development of dopaminergic neurons.
- Microglia-derived plasminogen may play a crucial role in regulating dopaminergic neuron maturation.