Damage to the central nervous system (CNS) due to spinal cord injury (SCI), stroke, or neurodegenerative disorders such as Alzheimer's or Parkinson's disease result in failed axon regeneration and permanent loss of function. Some types of neurons (e.g. peripheral or embryonic) do succeed in regenerating axons by engaging pro-growth transcriptional programs. Thus it is increasingly clear that in addition to overcoming inhibitory external factors, re-activation of a pro-regenerative transcriptional program is crucial for successful CNS regeneration. The specific genes and associated molecular mechanisms that are required to initiate a successful regenerative response remain largely unknown, but growing evidence indicates that core molecular mechanisms driving cellular growth are well conserved across cell types. Specifically, it appears that genes that regulate growth and motility in the context of proliferating, cancerous cells may be important regulators of regenerative abilit in post- mitotic neurons. Consistent with this overall hypothesis, bioinformatics analysis has revealed a remarkable degree of overlap between transcription factors (TFs) that are implicated in cancer growth and TFs known to modulate axon regeneration. Moreover, new data indicates that many TFs previously identified as oncogenic or tumor suppressive have proven to regulate axon growth when expressed in neurons. In three Specific Aims, we will (1) Combine our expertise in high content screening technology along with highly efficient CRISPR based knockdown strategies to identify novel genes involved in regulation of axon growth by testing requirements for transcription factors implicated in cancer biology in promoting axon growth in vitro; (2) Engineer transcriptionally active and inactive forms of candidate genes to identify specific transcriptional domains of novel genes that are required for promoting regenerative axon growth; (3) Use integrated bioinformatics and high content screening to define functional networks of interacting transcription factors and identify optimal combinations for growth promotion. Ultimately, these studies will fill a critical gap in knowledge in the field through the identification of novel genes and concomitant transcriptional components that aid in CNS regeneration and thereby reveal therapeutic targets to improve regenerative capacity in humans.
A major challenge to treating injuries to the brain and spinal cord is that once severed, the nerve fibers that carry information are unable to regrow. This project addresses a critical need in public health by seeking to identify new genes that can boost the capacity of injured nerve cells to regenerate their fibers and restore lost connections.
| Venkatesh, Ishwariya; Mehra, Vatsal; Wang, Zimei et al. (2018) Developmental Chromatin Restriction of Pro-Growth Gene Networks Acts as an Epigenetic Barrier to Axon Regeneration in Cortical Neurons. Dev Neurobiol 78:960-977 |
| Callif, Ben L; Maunze, Brian; Krueger, Nick L et al. (2017) The application of CRISPR technology to high content screening in primary neurons. Mol Cell Neurosci 80:170-179 |
| Venkatesh, Ishwariya; Blackmore, Murray G (2017) Selecting optimal combinations of transcription factors to promote axon regeneration: Why mechanisms matter. Neurosci Lett 652:64-73 |
| Venkatesh, Ishwariya; Simpson, Matthew T; Coley, Denise M et al. (2016) Epigenetic profiling reveals a developmental decrease in promoter accessibility during cortical maturation in vivo. Neuroepigenetics 8:19-26 |
