title: Neuronal injury affects expression of helix-loop-helix transcription factors.
abstract: Helix-loop-helix transcription (HLH) factors regulate several stages of neuronal development including differentiation of individual populations of neurons and neurite growth. Here we demonstrate that axonal injury of corticospinal and dorsal root ganglion neurons induces changes in the expression of several HLH transcription factors that function as negative regulators of neurogenesis and neurite outgrowth. However, the expression of HLH transcription factors that stimulate neurogenesis is not affected by the axonal injury. Expression of HES, SHARP and Id family members is suppressed shortly after axonal injury and expression returns to normal levels after 14 days. We hypothesize that down-regulation of these HLH transcription factors is required for initiation of regenerative response to axonal injury.
authors.affiliation: Department of Surgery, Maxine Dunitz Neurosurgical Institute, CSMC Burns and Allen Research Institute, Cedars Sinai Medical Center, UCLA School of medicine, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA. kabosp@cshs.org
authors.forename: Peter
authors.initials: P
authors.lastname: Kabos
authors.forename: Andrea
authors.initials: A
authors.lastname: Kabosova
authors.forename: Toomas
authors.initials: T
authors.lastname: Neuman
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins / Q000235:genetics; D015536:Down-Regulation / Q000502:physiology; D005260:Female; D015870:Gene Expression / Q000502:physiology; D018257:Helix-Loop-Helix Motifs / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics; D051798:Inhibitor of Differentiation Protein 1; D051797:Inhibitor of Differentiation Protein 2; D009416:Nerve Regeneration / Q000502:physiology*; D016501:Neurites / Q000502:physiology; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D011712:Pyramidal Tracts / Q000166:cytology / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012097:Repressor Proteins / Q000235:genetics*; D012584:Sciatic Nerve / Q000166:cytology / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D051798:Inhibitor of Differentiation Protein 1; D051797:Inhibitor of Differentiation Protein 2; D012097:Repressor Proteins; D014157:Transcription Factors; C491538:Bhlhe40 protein, rat; C109509:Bhlhe41 protein, rat; C405694:Hairy, HRT1 protein; C489686:Hes5 protein, rat; C497454:ID1 protein, rat; C497451:Id2 protein, rat; C077478:HES5 protein, human