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

Abstract

ObjectiveThis study evaluates molecular, nutritional and biochemical alterations in human intervertebral discs between middle and old age.MethodsTwenty-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.ResultsThe old-aged group showed a decrease in content of sulphated and non-sulphated glycosaminoglycans 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.ConclusionsResults 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.

Development of an in vitro intervertebral disc innervation model to screen neuroinhibitory biomaterials

“…The initial candidate materials chosen for assessment with our in vitro disc innervation model were chondroitin sulfate (CS) biomaterials as there is a robust connection between increased disc innervation and the reduction of neuroinhibitory CSPGs that occurs with age and disc degeneration . The neuroinhibitory properties of CSPGs are determined by the different sulfation patterns of the CS the CSPGs contain because the sulfation pattern determines the neuronal receptors to which the CS can bind .…”

Intervertebral disc degeneration and regeneration: a motion segment perspective

“…The thickness of the bony endplate is greatest in the lumbar vertebra, with the anterior shell thickness greater than the posterior in both endplates, cranial and caudal to the disc (Edwards et al, 2001). The bony endplate is thinnest and most porous in the central region of the vertebra adjacent to the NP (Edwards et al, 2001;Zehra et al, 2015) The caudal bony endplate has significantly more marrow contact pores than the cranial endplate (Martins et al, 2018).…”

“…Further work is needed on facet joints, investigating alternate loading modalities, magnitudes and frequencies, as well as assaying additional anabolic outputs. In skeletal muscle, exercise is known to increase collagen synthesis rates and have broad anti-inflammatory effects (Miller et al, 2005;Petersen and Pedersen, 2005). Work in the SPARC null mouse model, which exhibits spontaneous disc degeneration, demonstrated that fibrotic remodelling and inflammation of the multifidus muscle could be successfully attenuated with physical activity (James et al, 2018;James et al, 2019).…”

Inflammatory biomarkers in sera of patients with intervertebral disc degeneration

“…Two distinct regions in intervertebral discs can be characterize, i.e ., annulus fibrosus (AF) with high amounts of collagen and nucleus pulposus rich in proteoglycans. ( 1 ) The principal proteoglycans found in intervertebral discs are aggrecan noncovalently attached to hyaluronic acid (HA). These proteoglycans' function allows compressive loads to intervertebral discs.…”

“…Há possibilidade de caracterização de duas regiões distintas nos discos intervertebrais: anel fibroso, com altas quantidades de colágeno, e núcleo pulposo (NP), rico em proteoglicanos. ( 1 ) Os principais proteoglicanos encontrados nos discos intervertebrais são agrecan aderidos de forma não covalente ao ácido hialurônico (AH). Sua função é permitir cargas compressivas nos discos intervertebrais.…”