Chronic Lower back pain (LBP) is the leading cause of disability and morbidity worldwide. Degeneration of the spine’s intervertebral discs (IVDs) is a common cause of chronic LBP and accounts for about 40% of all cases. IVDs are structures that are embedded in the spine, and when healthy they provide cushioning during movement. They are made of special tissue-specific cells including nucleus pulposus cells. Previous research shows that adding healthy nucleus pulposus cells to the degenerated IVDs could promote regeneration.
However, two problems exist when it comes to using them. Firstly, nucleus pulposus cells are scarce. This means that extensive expansion of these cells outside of the body is required to obtain enough cells for insertion into the degenerated IVDs. Secondly, once obtained, cells adapt to the culture conditions outside the body and can lose their capacity for IVD regeneration. Researchers can determine this ‘loss of fitness’ by characterizing several known markers which are expressed on the outside and inside of these cells (this characterizes their phenotype).
A promising strategy to optimize the expansion of these cells outside of the body is to focus on factors that influence the nucleus pulposus cell’s phenotype. Studies in humans show that increasing the concentration of particles dissolved in the lab’s culture medium – in other words increasing osmolarity – enhances the phenotype and regenerative capacity of nucleus pulposus cells. However, this has not been tested on dog NPCs even though dogs also suffer from LBD due to IVD degeneration and they represent a clinically relevant model for IVD regeneration in humans.
In this study, Lisanne Laagland and colleagues collected nucleus pulposus cells from dog spines showing mild degeneration of IVDs. These cells don’t have the optimal phenotype for IVD regeneration and can therefore be seen as unhealthy. By expanding these cells in culture media with varying osmolarities they aimed to
Study design
improve their phenotype and with that their regenerative capacity.
They found that these optimized expansion conditions indeed improved the phenotype of the dog nucleus pulposus cells, indicating that cells grown this way could be more suitable to regenerate the spine’s IVDs.
Taken together these results are an important piece of the puzzle to find an optimal treatment for chronic LBP in the future. By determining the optimal culture conditions of IVD cells, researchers can expand these precious cells more efficiently, leaving them more capable of regenerating IVD tissue.
However, the road to an efficient cell-based treatment is still long and several obstacles need to be overcome before both human and dog patients in the clinic can actually benefit from this treatment.
Read about other cell based therapies here!
Hyperosmolar expansion medium improves nucleus pulposus cell phenotype
Lisanne T. Laagland, Frances C. Bach, Laura B. Creemers, Christine L. Le Maitre, Deepani W. Poramba-Liyanage, Marianna A. Tryfonidou
First published : 18 August 2022
Abstract:
Background: Repopulating the degenerated intervertebral disc (IVD) with tissue-specific nucleus pulposus cells (NPCs) has already been shown to promote regeneration in various species. Yet the applicability of NPCs as cell-based therapy has been hampered by the low cell numbers that can be extracted from donor IVDs and their potentially limited regenerative capacity due to their degenerated phenotype. To optimize the expansion conditions, we investigated the effects of increasing culture medium osmolarity during expansion on the phenotype of dog NPCs and their ability to produce a healthy extracellular matrix (ECM) in a 3D culture model.
Methods: Dog NPCs were expanded in expansion medium with a standard osmolarity of 300 mOsm/L or adjusted to 400 or 500 mOsm/L in both normoxic and hypoxicconditions. Following expansion, NPCs were cultured in a 3D culture model in chon-drogenic culture medium with a standard osmolarity. Read-out parameters included cell proliferaton rate, morphology, phenotype and healthy ECM production.
Results: Increasing the expansion medium osmolarity from 300 to 500 mOsm/L resulted in NPCs with a more rounded morphology and a lower cell proliferation rate accompanied by the expression of several healthy NPC and progenitor markers at gene (KRT18, ACAN, COL2, CD73, CD90) and protein (ACAN, PAX1, CD24, TEK,CD73) level. The NPCs expanded at 500 mOsm/L were able to retain most of their phenotypic markers and produce healthy ECM during 3D culture independent of the oxygen level used during expansion.
Conclusions: Altogether, our findings show that increasing medium osmolarity during expansion results in an NPC population with improved phenotype, which could enhance the potential of cell-based therapies for IVD regeneration.
Funding information: Dutch Arthritis Society, Grant/Award Numbers: LLP12, LLP22; Horizon 2020 Framework Programme, Grant/Award Number: 825925
Read the full paper here!
Cookie | Duration | Description |
---|---|---|
lang | session | This cookie is used to store the language preferences of a user to serve up content in that stored language the next time user visit the website. |
pll_language | 1 year | This cookie is set by Polylang plugin for WordPress powered websites. The cookie stores the language code of the last browsed page. |
Cookie | Duration | Description |
---|---|---|
_ga | 2 years | This cookie is installed by Google Analytics. The cookie is used to calculate visitor, session, campaign data and keep track of site usage for the site's analytics report. The cookies store information anonymously and assign a randomly generated number to identify unique visitors. |
_gat_gtag_UA_137999563_1 | 1 minute | This cookie is set by Google and is used to distinguish users. |
_gid | 1 day | This cookie is installed by Google Analytics. The cookie is used to store information of how visitors use a website and helps in creating an analytics report of how the website is doing. The data collected including the number visitors, the source where they have come from, and the pages visted in an anonymous form. |
CONSENT | 16 years 4 months 16 days 3 hours 11 minutes | These cookies are set via embedded youtube-videos. They register anonymous statistical data on for example how many times the video is displayed and what settings are used for playback.No sensitive data is collected unless you log in to your google account, in that case your choices are linked with your account, for example if you click “like” on a video. |
Cookie | Duration | Description |
---|---|---|
IDE | 1 year 24 days | Used by Google DoubleClick and stores information about how the user uses the website and any other advertisement before visiting the website. This is used to present users with ads that are relevant to them according to the user profile. |
NID | 6 months | This cookie is used to a profile based on user's interest and display personalized ads to the users. |
test_cookie | 15 minutes | This cookie is set by doubleclick.net. The purpose of the cookie is to determine if the user's browser supports cookies. |
VISITOR_INFO1_LIVE | 5 months 27 days | This cookie is set by Youtube. Used to track the information of the embedded YouTube videos on a website. |
YSC | session | This cookies is set by Youtube and is used to track the views of embedded videos. |
yt-remote-connected-devices | never | These cookies are set via embedded youtube-videos. |
yt-remote-device-id | never | These cookies are set via embedded youtube-videos. |
yt.innertube::nextId | never | These cookies are set via embedded youtube-videos. |
yt.innertube::requests | never | These cookies are set via embedded youtube-videos. |
Cookie | Duration | Description |
---|---|---|
cookielawinfo-checkbox-functional | 1 year | The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". |