Hypoxia Helps Maintain Nucleus Pulposus Homeostasis by Balancing Autophagy and Apoptosis.
Oxid Med Cell Longev
; 2020: 5915481, 2020.
Article
em En
| MEDLINE
| ID: mdl-33029281
ABSTRACT
Intervertebral disc degeneration (IVDD) is a common cause of lower back pain. Programmed cell death (PCD) including apoptosis and autophagy is known to play key mechanistic roles in the development of IVDD. We hypothesized that the nucleus pulposus cells that make up the center of the IVD can be affected by aging and environmental oxygen concentration, thus affecting the development of IVDD. Here, we evaluated the phenotype changes and PCD signaling in nucleus pulposus cells in two different oxygen percentages (5% (hypoxia) and 20% (normoxia)) up to serial passage 20. NP cells were isolated from the lumbar discs of rats, and the chondrogenic, autophagic, and apoptotic gene expressions were analyzed during cell culture up to serial passage 20. Hypoxia significantly increased the number of autophagosomes, as determined by monodansylcadaverine staining and transmission electron microscopy. Furthermore, hypoxia triggered the activation of autophagic flux (beclin-1, LC3-II/LC3-I ratio, and SIRT1) with a concomitant decrease in the expression of apoptotic proteins (Bax and caspase-3). Despite injury and age differences, no significant differences were observed between the ex vivo lumbar disc cultures of groups incubated in the hypoxic chamber. Our study provides a better understanding of autophagy- and apoptosis-related senescence in NP cells. These results also provide insight into the effects of aging on NP cells and their PCD levels during aging.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Autofagia
/
Hipóxia Celular
/
Apoptose
Limite:
Animals
Idioma:
En
Revista:
Oxid Med Cell Longev
Assunto da revista:
METABOLISMO
Ano de publicação:
2020
Tipo de documento:
Article