Expression of nerve growth factor in the callus during fracture healing in a fracture model in aged mice.
Nerve growth factor
delayed union
fracture
Journal
Bio-medical materials and engineering
ISSN: 1878-3619
Titre abrégé: Biomed Mater Eng
Pays: Netherlands
ID NLM: 9104021
Informations de publication
Date de publication:
2022
2022
Historique:
pubmed:
7
9
2021
medline:
16
3
2022
entrez:
6
9
2021
Statut:
ppublish
Résumé
Impaired fracture healing results in extensive and prolonged disability and long-term pain. Previous studies reported that nerve growth factor (NGF) was expressed during fracture healing and that anti-NGF antibody improves physical activity associate with facture pain. However, NGF expression levels in delayed or non-union are not fully understood. We compared chronological changes in NGF in the callus of young mice after femur fracture with those in aged mice after femur fracture as a model of bone fracture in the elderly. We used young (age 8 weeks) and aged (age 10 months) male C57BL/6J mice. A fracture was generated in the femur. At 5, 7, 10, 14, 17, and 21 days after creation of a fracture, mRNA expression levels of Col2a1, Col10a1, NGF were evaluated using quantitative PCR. We examined NGF protein expression levels and localization in the callus at day 14 using ELISA and immunohistochemistry, respectively. Expression of NGF in the callus after femur fracture in aged mice was significantly greater than that in young mice at days 5, 7, 10, 17, and 21 days. NGF protein levels in the callus of aged mice were also significantly higher than that in young mice. Immunohistochemical staining showed that NGF was heavily expressed in hypertrophic chondrocytes in the callus in aged mice. It is suggested that delayed Col2a1 and Col10a1 expression reflects delayed chondrocyte formation and delayed chondrocyte maturation in aged mice and that higher NGF expression in aged mice at day 14 may be associated with the presence of remaining hypertrophic chondrocytes in callus with delaying endochondral ossification.
Sections du résumé
BACKGROUND
BACKGROUND
Impaired fracture healing results in extensive and prolonged disability and long-term pain. Previous studies reported that nerve growth factor (NGF) was expressed during fracture healing and that anti-NGF antibody improves physical activity associate with facture pain. However, NGF expression levels in delayed or non-union are not fully understood.
OBJECTIVE
OBJECTIVE
We compared chronological changes in NGF in the callus of young mice after femur fracture with those in aged mice after femur fracture as a model of bone fracture in the elderly.
METHODS
METHODS
We used young (age 8 weeks) and aged (age 10 months) male C57BL/6J mice. A fracture was generated in the femur. At 5, 7, 10, 14, 17, and 21 days after creation of a fracture, mRNA expression levels of Col2a1, Col10a1, NGF were evaluated using quantitative PCR. We examined NGF protein expression levels and localization in the callus at day 14 using ELISA and immunohistochemistry, respectively.
RESULTS
RESULTS
Expression of NGF in the callus after femur fracture in aged mice was significantly greater than that in young mice at days 5, 7, 10, 17, and 21 days. NGF protein levels in the callus of aged mice were also significantly higher than that in young mice. Immunohistochemical staining showed that NGF was heavily expressed in hypertrophic chondrocytes in the callus in aged mice.
CONCLUSIONS
CONCLUSIONS
It is suggested that delayed Col2a1 and Col10a1 expression reflects delayed chondrocyte formation and delayed chondrocyte maturation in aged mice and that higher NGF expression in aged mice at day 14 may be associated with the presence of remaining hypertrophic chondrocytes in callus with delaying endochondral ossification.
Identifiants
pubmed: 34487017
pii: BME211284
doi: 10.3233/BME-211284
doi:
Substances chimiques
Nerve Growth Factor
9061-61-4
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM