No abstract

Several studies suggest that variations in the concentration of plasma glycoproteins can influence cellular changes in a large number of diseases. In recent years, proton nuclear magnetic resonance (1H-NMR) has played a major role as an analytical tool for serum and plasma samples. In recent years, there is an increasing interest in the characterization of glycoproteins through 1H-NMR in order to search for reliable and robust biomarkers of disease. The objective of this review was to examine the existing studies in the literature related to the study of glycoproteins from an analytical and clinical point of view. There are currently several techniques to characterize circulating glycoproteins in serum or plasma, but in this review, we focus on 1H-NMR due to its great robustness and recent interest in its translation to the clinical setting. In fact, there is already a marker in H-NMR representing the acetyl groups of the glycoproteins, GlycA, which has been increasingly studied in clinical studies. A broad search of the literature was performed showing a general consensus that GlycA is a robust marker of systemic inflammation. The results also suggested that GlycA better captures systemic inflammation even more than C-reactive protein (CRP), a widely used classical inflammatory marker. The applications reviewed here demonstrated that GlycA was potentially a key biomarker in a wide range of diseases such as cancer, metabolic diseases, cardiovascular risk, and chronic inflammatory diseases among others. The profiling of glycoproteins through 1H-NMR launches an encouraging new paradigm for its future incorporation in clinical diagnosis.

SummaryIt has been suggested that the short-chain fatty acids (SCFAs) produced by anaerobic bacterial intestinal fermentation of soluble fiber may regulate lipid metabolism in intestine, thus reducing plasma cholesterol levels. However, the exact mechanism of action of SCFAs in lowering cholesterol levels is not fully understood. The aims of this study were to test the effects of SCFAs on gene expression in a human enterocyte cell line Caco-2/TC-7 and to validate microarray data by real-time PCR. Human Caco-2/TC-7 enterocytes were cultured on transwell filter inserts and incubated with the SCFAs acetate (Ac), propionate (Pr), and butyrate (Bu). Total RNA was then isolated for microarrays and quantitative real-time PCR analysis. Treatment of human enterocytes with Pr and Bu affects a wide variety of genes. These genes were classified according to the PANTHER classification system, and the results showed that different biological processes and metabolic pathways were modified by Pr and Bu treatment, including the intestinal cholesterol biosynthesis pathway. Differential array expression analysis showed that nine genes were downregulated in this pathway, and these results were validated by real-time PCR. This in vitro study allowed us to identify a wide variety of biological processes and metabolic pathways affected by the SCFAs tested. Importantly, our results show that the global effect of Pr and Bu is to downregulate the expression of nine key genes involved in intestinal cholesterol biosynthesis, thus possibly inhibiting this pathway.2008 IUBMB IUBMB Life, 60(11): 757-764, 2008