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Role of the ERK1/2 pathway in osmolarity effects on nucleus pulposus cell apoptosis in a disc perfusion culture.
- Source :
-
Journal of Orthopaedic Research . Jan2017, Vol. 35 Issue 1, p86-92. 7p. - Publication Year :
- 2017
-
Abstract
- ABSTRACT Osmolarity fluctuations are inevitable within the nucleus pulposus (NP). However, the effects of osmolarity on NP cell apoptosis within the organ-cultured disc remain unclear. The objective of this study was to investigate effects of different osmolarity levels (hypo-, iso-, and hyper-) and osmolarity modes (constant and cyclic) on NP cell apoptosis in a disc perfusion culture and to study the role of the ERK1/2 pathway in this regulatory process. Porcine discs were cultured for 7 days in different osmotic medium, including constant hypo-, iso-, and hyper-osmolarity (330, 430, and 550 mOsm/L, respectively) and cyclic-osmolarity (430 mOsm/L for 8 h, followed by 550 mOsm/L for 16 h). The role of the ERK1/2 pathway was investigated by using the pharmacological inhibitor U0126. NP cell apoptosis was analyzed by TUNEL staining, caspase-3 activity, gene expression of Bcl-2, Bax and caspase-3 and protein expression of cleaved caspase-3, and cleaved PARP. Our results showed that NP cell apoptosis was increased in hypo- and hyper-osmolarity cultures compared to iso- or cyclic-osmolarity culture, whereas the level of apoptosis in the iso-osmolarity culture was lower than that in the cyclic-osmolarity culture. When the ERK1/2 pathway was inhibited in the iso- and cyclic-osmolarity cultures, the level of NP cell apoptosis was significantly increased. In conclusion, the effects of osmolarity on NP cell apoptosis depend on the osmolarity level (hypo-, iso-, or hyper-) and osmolarity mode (constant or cyclic). Futhermore, inhibition of the ERK1/2 pathway promotes NP cell apoptosis in this process. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:86-92, 2017. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 07360266
- Volume :
- 35
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Journal of Orthopaedic Research
- Publication Type :
- Academic Journal
- Accession number :
- 120900028
- Full Text :
- https://doi.org/10.1002/jor.23249