title: Effects of age and insulin-like growth factor-1 on rat neurotrophin receptor expression after nerve injury.
abstract: Neurotrophin receptors, such as p75(NTR) , direct neuronal response to injury. Insulin-like growth factor-1 receptor (IGF-1R) mediates the increase in p75(NTR) during aging. The aim of this study was to examine the effect of aging and insulin-like growth factor-1 (IGF-1) treatment on recovery after peripheral nerve injury.
  
  
  
  Young and aged rats underwent tibial nerve transection with either local saline or IGF-1 treatment. Neurotrophin receptor mRNA and protein expression were quantified.
  
  
  
  Aged rats expressed elevated baseline IGF-1R (34% higher, P = 0.01) and p75(NTR) (68% higher, P < 0.01) compared with young rats. Post-injury, aged animals expressed significantly higher p75(NTR) levels (68.5% above baseline at 4 weeks). IGF-1 treatment suppressed p75(NTR) gene expression at 4 weeks (17.2% above baseline, P = 0.002) post-injury.
  
  
  
  Local IGF-1 treatment reverses age-related declines in recovery after peripheral nerve injuries by suppressing p75(NTR) upregulation and pro-apoptotic complexes. IGF-1 may be considered a viable adjuvant therapy to current treatment modalities. Muscle Nerve 54: 769-775, 2016.
authors.affiliation: Department of Orthopaedic Surgery, Wake Forest Baptist Medical Center, Medical Center Boulevard, Winston-Salem, North Carolina, 27157, USA.
authors.forename: T David
authors.initials: TD
authors.lastname: Luo
authors.affiliation: Department of Orthopaedic Surgery, Wake Forest Baptist Medical Center, Medical Center Boulevard, Winston-Salem, North Carolina, 27157, USA.
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Alton
authors.affiliation: Department of Orthopaedic Surgery, Wake Forest Baptist Medical Center, Medical Center Boulevard, Winston-Salem, North Carolina, 27157, USA.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Apel
authors.affiliation: Department of Orthopaedic Surgery, Wake Forest Baptist Medical Center, Medical Center Boulevard, Winston-Salem, North Carolina, 27157, USA.
authors.forename: Jiaozhong
authors.initials: J
authors.lastname: Cai
authors.affiliation: Department of Orthopaedic Surgery, Wake Forest Baptist Medical Center, Medical Center Boulevard, Winston-Salem, North Carolina, 27157, USA.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Barnwell
authors.affiliation: Department of Geriatric Medicine, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA.
authors.forename: William E
authors.initials: WE
authors.lastname: Sonntag
authors.affiliation: Department of Orthopaedic Surgery, Wake Forest Baptist Medical Center, Medical Center Boulevard, Winston-Salem, North Carolina, 27157, USA.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Smith
authors.affiliation: Department of Orthopaedic Surgery, Wake Forest Baptist Medical Center, Medical Center Boulevard, Winston-Salem, North Carolina, 27157, USA. zli@wakehealth.edu.
authors.forename: Zhongyu
authors.initials: Z
authors.lastname: Li
mesh_terms: D000367:Age Factors; D000375:Aging / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015870:Gene Expression; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D059348:Peripheral Nerve Injuries / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D017526:Receptor, IGF Type 1 / Q000096:biosynthesis / Q000235:genetics; D017475:Receptors, Nerve Growth Factor / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D017475:Receptors, Nerve Growth Factor; C548904:insulin-like growth factor-1, rat; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1
keywords: IGF-1; aging; insulin-like growth factor-1; nerve growth factor; nerve regeneration; neurotrophin receptor; peripheral nerve injury