An NMR- and MS-based metabonomic investigation of saliva metabolic changes in feline odontoclastic resorptive lesions (FORL)-diseased cats

Abstract

The feline odontoclastic resorptive lesion (FORL) is a common oral problem in cats. The disease has increased steadily since the domestication of cats and etiology of this disease has not been fully determined although several theories have been proposed. Feeding practices, vaccination, and neutering programs have all been suspected to be associated with FORL. The aim of the current study is to assess the feasibility of metabonomics to detect at an early stage the onset of the disease. The diagnostic biomarkers could then be used as ''efficacy markers'' for nutritional intervention in preventing and/or slowing the progression of FORL. 1 H-NMR-and LC/MS-based metabonomic analysis of saliva samples obtained from a group of 21 cats (11 healthy and 10 FORL diseased) showed clear differences in the metabolic composition of saliva from healthy and FORL-diseased cats. To identify biomarkers, the spectroscopic data was processed using partial least-squares discriminant analysis (PLS-DA) and validated by leave-one-subject-out cross validation. The PLS-DA model predicted FORL-diseased cats with over 60% accuracy. The maximum value of Q 2 of the random permutation sets was less than 0.3. The diseased cats showed increased levels of many organic and amino acids, such as acetate, lactate, propionate, isovalerate, tryptamine, and phenylalanine suggesting changes in oral microflora in the disease situation. This study is preliminary and a larger study with more samples to further validate the biomarker profile predictive of an early FORL pathophysiological status is in progress.

Individual Human Metabolic Phenotype Analyzed by 1H NMR of Saliva Samples

“…The samples were thawed at room temperature and centrifuged (14 000 rpm for 30 min at 4 °C) to remove cells, mucus, and macromolecules. 540 μL of supernatant was then taken and immediately added to 60 μL of phosphate buffer (composition: 0.2 M Na 2 HPO 4 , 0.2 M NaH 2 PO 4 , 30 mM NaN 3 , and 10 mM TSP (sodium trimethylsilyl [2,2,3,3- 2 H 4 ] propionate) in 100% 2 H 2 O; pH 7.4) . NaN 3 was also added as a preservative to ensure that metabolites were not generated or consumed due to bacteria present in the saliva during the time of preparation of the samples or of the acquisition of NMR spectra.…”

Potential of Human Saliva for Nuclear Magnetic Resonance-Based Metabolomics and for Health-Related Biomarker Identification

“…Metabolomics, the term describing the global analysis of metabolites, has emerged as a powerful approach used in many disciplines to study how a stimulus causes perturbations in the metabolite profile. Nuclear magnetic resonance (NMR) is one of the principal analytical technique for metabolomic purposes, , and blood and urine are the biofluids most frequently studied in these investigations. , In contrast, the use of saliva in metabolomic studies are rare; , however, recently a comprehensive investigation of the salivary metabolome was reported . This is despite the fact that the use of saliva has an important advantage, as it is easily accessible and can be sampled noninvasively without the introduction of stress or pain.…”

Advances in separation science applied to metabonomics

“…Ramadan et al . 41 observed that there are increased levels of acetate, lactate, propionate, isovalerate, tryptamine and phenylalanine, indicating changes in oral microflora of cats infected with feline odontoclastic resorptive lesion, suggesting that it is possible to predict feline odontoclastic resorptive lesion disease at early stage by monitoring metabolite profiles in saliva samples. Williams et al .…”