Spinal cord neuroblasts proliferate in response to basic fibroblast growth factor

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• Trophic factors are crucial epigenic signals in embryonic development.
• Understanding signals that regulate neural cell proliferation is vital for developmental neuroscience.

Purpose of the Study:

• To investigate the mitogenic effects of basic fibroblast growth factor (bFGF) on embryonic spinal cord cells.
• To characterize neuroblasts proliferating in response to bFGF and establish long-term cultures.
• To explore the potential for stable gene transduction in these neuroblast cultures.

Main Methods:

• Established long-term cultures of embryonic spinal cord neuroblasts.
• Utilized high concentrations of bFGF (10-100 ng/ml) to assess mitogenic effects.
• Performed morphological and biochemical characterizations, including immunocytochemistry for neuronal markers.
• Employed retroviral vectors for stable gene transduction of the Escherichia coli beta-galactosidase (LacZ) gene.

Main Results:

• bFGF acts as a potent mitogen for committed neuroblasts, with a doubling time of 2.5 days.
• Long-term cultures of neuroblasts were successfully established, demonstrating stability through passaging and cryopreservation.
• Astrocytes showed limited proliferation in response to bFGF, indicating specificity for neuroblasts.
• Cholinergic, GABAergic, and a small population of motoneurons were identified in the cultures.
• Epidermal growth factor (EGF) also exhibited mitogenic effects, but to a lesser extent than bFGF.
• Stable transduction of the LacZ gene into neuroblasts was achieved using retroviral vectors.

Conclusions:

• bFGF selectively promotes the proliferation of embryonic spinal cord neuroblasts.
• Established neuroblast cultures are suitable for long-term studies and genetic manipulation.
• The ability to stably transduce genes into these cells opens avenues for in vivo research on neuronal function and gene expression.