Abstract |
Although evidence shows that intervertebral disc degeneration is generally characterized by angiogenesis, the role of angiopoietin has not been investigated. This study examined the presence of angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) within the native intervertebral disc (IVD) and elucidated their functions in the regulation of nucleus pulposus (NP) cells. Initial investigation of uncultured NP tissue revealed that Ang-1 and Ang-2 were expressed by native NP cells. Ang-2 expression was significantly increased in infiltrated and degenerate samples relative to normal samples. The ratio of Ang-2/Ang-1 in tissues from patients increased markedly with increasing age and level of degeneration of the IVD. The ratio of both Ang-2/Ang-1 mRNA and protein increased over time when cells were subjected to constant pressure at 1 Mpa in vitro. Our findings indicate that Ang-2 plays a role in suppressing cell adhesion and viability, and promotes the apoptosis of NP cells and that Ang-2 can inhibit the pathways stimulated by Ang-1 and fibronectin. Ang-2 release during IVD degeneration causes higher ratio of Ang-2 to Ang-1, further inhibits NP cell viability and adhesion, promoting apoptosis by blocking PI3K/Akt signaling. The present study therefore provides new insights into the role of the angiopoietin-Tie system in the pathogenesis of IVD degeneration.
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Authors | Kun Wang, Wei Liu, Yu Song, Xinghuo Wu, Yukun Zhang, Shuai Li, Yong Gao, Ji Tu, Yingle Liu, Cao Yang |
Journal | Laboratory investigation; a journal of technical methods and pathology
(Lab Invest)
Vol. 97
Issue 8
Pg. 971-982
(08 2017)
ISSN: 1530-0307 [Electronic] United States |
PMID | 28394321
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- ANGPT1 protein, human
- ANGPT2 protein, human
- Angiopoietin-1
- Angiopoietin-2
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Topics |
- Adolescent
- Adult
- Angiopoietin-1
(analysis, metabolism)
- Angiopoietin-2
(analysis, metabolism)
- Apoptosis
(physiology)
- Cell Adhesion
- Cell Survival
- Cells, Cultured
- Humans
- Intervertebral Disc Degeneration
(metabolism)
- Middle Aged
- Nucleus Pulposus
(cytology, metabolism)
- Signal Transduction
(physiology)
- Young Adult
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