Age- and degeneration-related variations in cell density and glycosaminoglycan content in the human cervical intervertebral disc and its endplates

Abstract

The first aim of this study was to quantify cell density in cervical intervertebral discs (IVDs) and endplates of varying age and degeneration grade. The second aim was to analyze glycosaminoglycan (GAG) content in cervical IVDs and their endplates. Sixty cervical IVDs were excised from 30 human cadavers, not later than 24 hours post-mortem. Each sample underwent sectioning. Half of each sample underwent GAG content analysis using the dimethylmethylene blue binding assay. The other half underwent histological processing, histological degeneration grading, and cell density assessment using the Abercrombie method. The nucleus pulposus (NP) (4218 ±417 cells/mm 3 ) had significantly higher cell density than the anterior annulus fibrosus (AF) (3283 ±438 cells/mm 3 ; p < 0.0001), and similar cell density (4464 ±551 cells/mm 3 ; p = 0.36) to the posterior AF. Cell density was similar throughout the different regions of the endplate. The NP (619 ±178 µg/mg dry weight) had a significantly higher GAG content than both the anterior (428 ±199 µg/mg dry weight; p < 0.0001) and posterior AF (524 ±218 µg/mg dry weight; p < 0.0001). In conclusion, this study introduces detailed 3D maps of cervical IVD and endplate cell density and GAG content. Furthermore, it shows that cervical IVDs and their endplates only slightly differ, in terms of cell density and GAG content, from lumbar IVDs.

Annulus fibrosus cell phenotypes in homeostasis and injury: implications for regenerative strategies

“…In the human adult, reported AF cell density ranges from approximately 3000 to 9000 cells/mm³ . This range is markedly lower than that of mature hyaline cartilage, which ranges from 16,000 to 60,000 cells/mm³ .…”

“…In the human adult, reported AF cell density ranges from approximately 3000 to 9000 cells/mm³. [69][70][71] This range is markedly lower than that of mature hyaline cartilage, which ranges from 16,000 to 60,000 cells/mm³. 71,72 Despite low AF cell density, there is significant heterogeneity of cell types residing within the AF under healthy conditions.…”

Annulus fibrosus cell sheets limit disc degeneration in a rat annulus fibrosus injury model

“…Moreover, AF tissue maintenance and repair depends on lower cell numbers than other cartilage tissues. The cell density of articular cartilage is estimated at 14000‐15000 cells/mm 3 ; whereas, it is as low as 6000 cells/mm 3 on average in the total IVD, with reports as low as 3000‐4000 cells/mm 3 for the AF . In addition, the AF is largely an avascular tissue, therefore limiting its nutrient supply.…”

“…According to Nishimura grading, degeneration was significantly halted at weeks 4, 8, and 12 in group S compared to that in group D. Abbreviations: D: AF defect only group, S: AF defect treated with sheet transplantation group, C: sham group ** P <.01, comparing group S to group D (n = 9) low as 3000-4000 cells/mm 3 for the AF. 41 In addition, the AF is largely an avascular tissue, therefore limiting its nutrient supply.…”

Anti-aging effect and gene expression profiling of dung beetle glycosaminoglycan in aged rats

“…In fact, although GAGs constitute a minor portion of native tissues, they play a crucial role in various physiological processes [2]. There are many reports that GAGs are related to age; they have been implicated in such processes as degeneration of cervical intervertebral discs [3, 4], age-related diseases that impair bone healing [5], and prevention of cancer [6]. They have been shown to be associated with age-related changes in matrix components and the onset of diseases of aging, especially cardiovascular pathologies, and are mostly involved in the age-dependence of biological functions and the limitation of longevity [7].…”