Urinary metabolite biomarkers changes in obesity-induced nafld and obesity-induced nafld plus xx

Obesity-induced Non-alcoholic fatty liver disease (NAFLD) is the leading causes of chronic liver disease, affecting 25% globally. It starts as hepatic steatosis, progresses to steatohepatitis, fibrosis, cirrhosis and possible hepatocellular cancer. NAFLD is often associated with obesity plus insulin resistance or type 2 diabetes. Liver function blood tests and non-invasive radiological imaging are clinically used to detect NAFLD. Whilst, liver biopsy remains the “gold standard” for detection and staging, the procedure is invasive and can be unreliable especially in obese patients.^1–3 There is a need for specific, non-invasive biomarkers for the detection and staging of NAFLD. Our aim was to assay urine metabolite changes in mice with obesity-induced NAFLD and obesity-induced NAFLD plus agent XX. C57BL/6 mice (n=78) were fed a diet comprising high fat (54%), high cholesterol (1.4%) with high sucrose (55%) and fructose (45%) in drinking water, to simulate the diet typically consumed by obese patients with NAFLD. The urine of mice fed the obesogenic diet (OD) and OD plus XX (OD-XX), with their parallel controls fed normal chow (NC) for ~40 weeks, were assayed with metabolomic techniques. These techniques were Fourier-transform infrared (FT-IR), 1H Nuclear magnetic resonance (NMR), 2D 1H-1H total correlation heteronuclear single quantum coherence (TOCSY) and electrospray liquid chromatography-mass spectrometry (ESI-LC-MS/MS) with multivariate analysis. Body, liver, liver/body weights, liver biochemistry and liver histology were evaluated. Sera AST (IU/L) were elevated in OD and OD-XX cohorts compared to NC and decreased in OD-XX group vs OD (367.00±46 vs 544.00±22 vs 335.70±35.05; NC vs OD vs OD-XX; p<0.01). Sera ALT (IU/L) levels were also increased in OD and OD-XX cohorts and reduced in OD-Tx group vs OD (101.70±15.79 vs 401.40±10.57 vs 319.40±43.79, NC vs OD vs OD-XX; p<0.01). The NASH clinical research network scores increased for OD and OD-XX livers vs NC (1.0±0.2 vs 5.10±0.28 vs 5.92±0.28; NC vs OD and NC vs OD-XX, p<0.04; OD vs OD-XX – not significant). Principal component analysis score (PCA) plot (figure 1) urine NMR spectra displayed differences between OD and OD-Tx groups, indicating that XX induced metabolite changes. We have identified specific urinary metabolites with 1H NMR, 2D 1H-1H TOCSY and ESI-LC-MS/MS. The results demonstrate that metabolomic approaches may be useful in detecting novel biomarkers in human NAFLD.

References

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