The influence of oxygen concentration on the extracellular matrix production of human nucleus pulposus cells during isolation-expansion process
- 14 February 2017
- journal article
- research article
- Published by Wiley in Journal of Biomedical Materials Research Part A
- Vol. 105 (6), 1575-1582
- https://doi.org/10.1002/jbm.a.36020
Abstract
Nucleus pulposus (NP) cells locate in the center of avascular intervertebral discs, and thus have presumably adapted to a hypoxic environment. The purpose of this study was to investigate the influences of hypoxic condition, during isolation-expansion of human NP cells, on the cellular proliferation and extracellular matrix (ECM) synthesis in later three-dimensional cultures. Human NP tissues were obtained from patients who underwent lumbar disc surgeries. Immediately after retrieval, NP tissues from each patient were divided into two aliquots for in vitro cultivation either under classical normoxic (21% O ) or hypoxic (3.5% O ) condition. After isolation-expansion processes, microtissues of NP cells were formed and the analysis was performed after one-week culture. Experiments of pretreatment with TGF-β1 or lovastatin were designed to investigate if the isolation-expansion conditions affect the responsiveness to later exogenous treatments. Hypoxic isolation-expansion stimulated NP cell proliferation during monolayer culture. Hypoxia also upregulated mRNA levels of SOX9 and HIF-1α but downregulated type X collagen as well as improved aggrecan and type II collagen synthesis. Although TGF-β1 had no substantial effect, lovastatin pretreatment showed a greater enhancement on type II collagen expression in hypoxic group. Normoxia negatively affected the biochemical composition of regenerated ECM attributable to downregulation of SOX9 and HIF-1α, while hypoxia enhanced cellular proliferation, improved matrix production, and maintained a functional phenotype of NP cells. Hypoxic isolation-expansion of human NP cells is important to achieve better regenerative cells for later cultivation or cell transplantation. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1575-1582, 2017.Keywords
Funding Information
- Ministry of Science and Technology, Taiwan (99-2628-B-002-041-MY3)
This publication has 40 references indexed in Scilit:
- Clinical experience in cell-based therapeutics: Disc chondrocyte transplantationBiomolecular Engineering, 2007
- Clinical experience in cell-based therapeutics: intervention and outcomeEuropean Spine Journal, 2006
- Nutrition of the Intervertebral DiscSpine, 2004
- The role of the physicochemical environment in determining disc cell behaviourBiochemical Society Transactions, 2002
- A potential role for cell-based therapeutics in the treatment of intervertebral disc herniationEuropean Spine Journal, 2002
- Intervertebral Disc Cells Exhibit Differences in Gene Expression in Alginate and Monolayer CultureSpine, 2001
- Why the back of the child?European Spine Journal, 1999
- The human lumbar intervertebral disc: evidence for changes in the biosynthesis and denaturation of the extracellular matrix with growth, maturation, ageing, and degeneration.JCI Insight, 1996
- Factors Influencing Oxygen Concentration Gradients in the Intervertebral DiscSpine, 1991
- Early Onset of Disk Degeneration and Spondylosis in Sand Rats (Psammomys Obesus)Veterinary Pathology, 1983