Changes in human intervertebral disc biochemical composition and bony end plates between middle and old age

Author(s)

Martins, Delio Eulalio ^[1] ; de Medeiros, Valquiria Pereira ^{[2, 3]} ; Wajchenberg, Marcelo ^[1] ; Paredes-Gamero, Edgar Julian ^{[4, 3]} ; Lima, Marcelo ^[4] ; Reginato, Rejane Daniele ^[5] ; Nader, Helena Bonciani ^[4] ; Puertas, Eduardo Barros ^[1] ; Faloppa, Flavio ^[1]

Affiliation

^[1] Univ Fed Sao Paulo, Dept Orthopaed & Traumatol, UNIFESP, Sao Paulo, SP - Brazil

^[2] Univ Fed Juiz de Fora, Dept Biochem, Juiz De Fora, MG - Brazil

^[3] Univ Fed Mato Grosso do Sul, Fac Pharmaceut Sci, Campo Grande, MS - Brazil

^[4] Univ Fed Sao Paulo, Dept Biochem, UNIFESP, Sao Paulo, SP - Brazil

^[5] Univ Fed Sao Paulo, Dept Morphol & Genet, UNIFESP, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: PLoS One; v. 13, n. 9 SEP 18 2018.
• Web of Science Citations: 2

Abstract

Objective This study evaluates molecular, nutritional and biochemical alterations in human intervertebral discs between middle and old age. Methods Twenty-eight human lumbar intervertebral discs from donors were evaluated and separated into two groups: Middle-aged (35-50 years old, relatively non-degenerate discs of Pfirrmann grades 1-3, n = 15) and Old-aged (>= 80 years old, all degenerate Pfirrmann grade 4 or 5, n = 13). Parameters which might be expected to to be related to nutrient supply and so the health of disc cells (eg the porosity of the vertebral endplate, cell viability and cell density) and to disc extracellular composition (ie quantification of glycosaminoglycan disaccharides and hyaluronic acid molecular weight) and collagen organization, were analyzed. Three regions of the intervertebral disc (anterior annulus fibrosus, nucleus pulposus, and posterior annulus fibrosus) were examined. Results The old-aged group showed a decrease in content of sulphated and non-sulphated glycos-aminoglycans relative to middle-aged and there were also alterations in the proportion of GAG disaccharides and a decrease of collagen fiber size. Hyaluronic acid molecular weight was around 200 kDa in all regions and ages studied. The anterior annulus differed from the posterior annulus particularly in relation to cell density and GAG content. Additionally, there were changes in the bony endplate, with fewer openings observed in the caudal than cranial endplates of all discs in both groups. Conclusions Results show the cranial vertebral endplate is the main vascular source for the intervertebral discs. Hylauronic acid molecular weight is the same through the intervertebral disc after age of 50 years. (AU)