Do Yup Lee

Stress is now recognized as a universal premorbid factor associated with many risk factors of various chronic diseases. Acute stress may induce an individual's adaptive response to environmental demands. However, chronic, excessive stress causes cumulative negative impacts on health outcomes through "allostatic load". Thus, monitoring the quantified levels of long-term stress mediators would provide a timely opportunity for prevention or earlier intervention of stress-related chronic illnesses.

NAFLD progression was robustly associated with metabolic dys-regulations in the SCFAs, bile acid and indole compounds, and NAFLD can be accurately diagnosed using the metabolites. L. lactis and P. pentosaceus ameliorate NAFLD progression by modulating gut metagenomic and metabolic environment, particularly tryptophan pathway, of the gut-liver axis.

Drastic alterations in macronutrients are known to cause large changes in biochemistry and gene expression in the photosynthetic alga Chlamydomonas reinhardtii. However, metabolomic and proteomic responses to subtle reductions in macronutrients have not yet been studied. When ammonium levels were reduced by 25-100% compared with control cultures, ammonium uptake and growth rates were not affected at 25% or 50% nitrogen-reduction for 28 h. However, primary metabolism and enzyme expression showed

Our understanding of biology has been greatly improved through recent developments in mass spectrometry, which is providing detailed information on protein and metabolite composition as well as protein-metabolite interactions. The high sensitivity and resolution of mass spectrometry achieved with liquid or gas chromatography allows for detection and quantification of hundreds to thousands of molecules in a single measurement. Where homogenization-based sample preparation and extraction methods r

Emerging evidences about gut-microbial modulation have been accumulated in the treatment of nonalcoholic fatty liver disease (NAFLD). We evaluated the effect of <i>Bifidobacterium breve</i> and <i>Bifidobacterium longum</i> on the NAFLD pathology and explore the molecular mechanisms based on multi-omics approaches. Human stool analysis [healthy subjects (<i>n</i> = 25) and NAFLD patients (<i>n</i> = 32)] was performed to select NAFLD-associated microbiota. Six-week-old male C57BL/6 J mice were f

Trinucleotide repeats (TNRs) expansion disorders are severe neurodegenerative and neuromuscular disorders that arise from inheriting a long tract (30-50 copies) of a trinucleotide unit within or near an expressed gene (Figure 1a). The mutation is referred to as 'trinucleotide expansion' since the number of triplet units in a mutated gene is greater than the number found in the normal gene. Expansion becomes obvious once the number of repeating units passes a critical threshold length, but what h

Rapamycin, known as an inhibitor of Target of Rapamycin (TOR), is an immunosuppressant drug used to prevent rejection in organ transplantation. Despite the close association of the TOR signaling cascade with various scopes of metabolism, it has not yet been thoroughly investigated at the metabolome level. In our current study, we applied mass spectrometric analysis for profiling primary metabolism in order to capture the responsive dynamics of the Chlamydomonas metabolome to the inhibition of TO

Particulate matter (PM) exposure is related to an increased risk of sporadic Alzheimer's disease (AD), the pathogenesis of which is explained by chronic neurometabolic disturbance. Therefore, PM-induced alterations in neurometabolism might herald AD. We aimed to identify brain region-specific changes in metabolic pathways associated with ultrafine particle (UFP) exposure and to determine whether such metabolic alterations are linked to susceptibility to AD. We constructed UFP exposure chambers a

For the elemental determination of rice, a microwave-assisted sample preparation method employing diluted HNO3 and H2O2 under high temperature and pressure was developed in a rapid and eco-friendly manner. The analysis was performed using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). At 280 °C and 160 bar, the optimal condition for microwave-assisted wet digestion in a single reaction chamber was achieved with a mixt

In a variety of neurological diseases, pathological progression is cell type and region specific. Previous reports suggest that mass spectrometry imaging has the potential to differentiate between brain regions enriched in specific cell types. Here, we utilized a matrix-free surface mass spectrometry approach, nanostructure initiator mass spectrometry (NIMS), to show that spatial distributions of multiple lipids can be used as a 'fingerprint' to discriminate between neuronal- and glial- enriched

With the increase in soybean trade between countries, the intentional mislabeling of the origin of soybeans has become a serious problem worldwide. In this study, metabolic profiling of soybeans from the Republic of Korea and China was performed by nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate statistical analysis to predict the geographical origin of soybeans. The optimal orthogonal partial least squares-discriminant analysis (OPLS-DA) model was obtained using total ar