Bcl-x(L) increases axonal numbers but not axonal elongation from rat retinal explants
Gunnar P H Dietz1, Birgit Dietz, Mathias Bähr
1DFG Research Center for Molecular Physiology of the Brain (CMPB), Neurologische Universitätsklinik, Waldweg 33, 37073 Göttingen, Germany. gdietz@gwdg.de
Abstract:
The Bcl-2 family of proteins has been characterized as a key regulator of cell death programs. In addition, these proteins also play important roles in cellular differentiation, such as axonal growth. The role of Bcl-2 family members on axonal regeneration and neurite extension has been controversial so far. Here, we examine the influence of Bcl-x(L) on axonal regeneration from adult retina explants in vitro. We delivered recombinant Bcl-x(L) into retinal tissue, mediated by the Tat-protein transduction domain, and observed its effect on retinal axon extension. We found that Bcl-x(L) increased the number of regenerating neurites, but did not increase their length. Our results indicate that Bcl-x(L) stimulates axonal initiation but not axonal elongation after crush injury to retinal explants, without altering the number of surviving neurons.
Insights
Bcl-x(L) protein promotes the initiation of new neurites in retinal axon regeneration but does not enhance their elongation. This finding clarifies the role of Bcl-2 family proteins in nerve repair after injury.
Area of Science:
- Neuroscience
- Cell Biology
- Molecular Biology
Background:
- The Bcl-2 family regulates cell death and differentiation, including axonal growth.
- The specific role of Bcl-2 family members in axonal regeneration remains debated.
Purpose of the Study:
- To investigate the effect of Bcl-x(L) on axonal regeneration in adult retinal explants.
- To determine if Bcl-x(L) influences neurite initiation and/or elongation.
Main Methods:
- Recombinant Bcl-x(L) was delivered to retinal tissue using the Tat-protein transduction domain.
- Axonal regeneration and neurite extension were observed in vitro after crush injury.
Main Results:
- Bcl-x(L) significantly increased the number of regenerating neurites.
- Bcl-x(L) did not increase the length of the regenerating neurites.
- Neuron survival was not affected by Bcl-x(L) treatment.
Conclusions:
- Bcl-x(L) promotes axonal initiation in retinal explants.
- Bcl-x(L) does not promote axonal elongation after injury.
- These findings clarify the function of Bcl-x(L) in nerve regeneration.
