1H NMR investigation of changes in the metabolic profile of synovial fluid in bilateral canine osteoarthritis with unilateral joint denervation

Abstract

This study lends support to the principle of neurogenic acceleration of OA in that the observed differences in metabolite concentrations found in the denervated knee fluids seem to correlate with metabolic changes resulting from aggravation of the OA process caused by joint denervation.

Metabolomics in rheumatic diseases: desperately seeking biomarkers

“…The samples were analysed by 1 H-NMR and GC–MS, and the differences in metabolic profiles were indicative of hypoxic conditions in diseased and inflamed knee joints, and high energy requirements in patients with OA 84 . Similar alterations have been described previously 84–88 , with some variations in the involvement of specific metabolites, possibly owing to the use of animal models 84–86,88 or the lack of a healthy human control group 87 . These studies did not include samples from other inflammatory arthritides, so further studies are needed to determine the specific metabolomic profile of OA.…”

Metabolic analysis of knee synovial fluid as a potential diagnostic approach for osteoarthritis

“…A decrease in the methionine concentration indicates its utilization, where it is likely converted to S‐adenosylmethionine (SAM), which has been proposed as a cartilage damage repairing and inflammatory reducing factor . Interestingly, the metabolic pathways and physiological conditions highlighted here (i.e., hypoxia, inflammation and high energy requirements) are similar to those described in previous metabolomics studies of OA in SF . However, specific differences between metabolites could be due to the fact that some of the earlier studies focused on OA in animal models only or were lacking a healthy control group when examining a human population .…”

“…32 Interestingly, the metabolic pathways and physiological conditions highlighted here (i.e., hypoxia, inflammation and high energy requirements) are similar to those described in previous metabolomics studies of OA in SF. 11,[33][34][35][36][37] However, specific differences between metabolites could be due to the fact that some of the earlier studies focused on OA in animal models only 11,[33][34][35] or were lacking a healthy control group when examining a human population. 36,37 Together with these previous studies, the significant changes in the metabolites detected in our study provide a way to identify OA in SF, and further work may provide insight into the mechanisms of disease progression and identification of therapeutic targets.…”

Serum branched-chain amino acid to histidine ratio: a novel metabolomic biomarker of knee osteoarthritis

“…Leucine has been shown to increase the release of acetoactate and 3-hydroxybutyrate as a result of the partial oxidation of leucine. An increased concentration of hydroxybutyrate in osteoarthritic synovial fluids and urine sample has been observed,3 6 17 also favouring this hypothesis. This may be true given that the BCAA are essential amino acids and cannot be synthesised within the body.…”