MRMQuant: Automated MRM Data Quantitation for Large-Scale Targeted Metabolomics Analysis.

Multiple reaction monitoring (MRM) is a powerful and popular technique used for metabolite quantification in targeted metabolomics. Accurate and consistent quantitation of metabolites from the MRM data is essential for subsequent analyses. Here, we developed an automated tool, MRMQuant, for targeted metabolomic quantitation using high-throughput liquid chromatography-tandem mass spectrometry MRM data to provide users with an easy-to-use tool for accurate MRM data quantitation with minimal human intervention. This tool has many user-friendly functions and features to inspect and correct the quantitation results as required. MRMQuant possesses the following features to ensure accurate quantitation: (1) dynamic signal smoothing, (2) automatic deconvolution of coeluted peaks, (3) absolute quantitation via standard curves and/or internal standards, (4) visualized inspection and correction, (5) corrections applicable to multiple samples, and (6) batch-effect correction.

NMR-Based Analysis of Plasma Lipoprotein Subclass and Lipid Composition Demonstrate the Different Dietary Effects in ApoE-Deficient Mice.

Plasma lipid levels are commonly measured using traditional methods such as triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and cholesterol (CH). However, the use of newer technologies, such as nuclear magnetic resonance (NMR) with post-analysis platforms, has made it easier to assess lipoprotein profiles in research. In this study involving ApoE-deficient mice that were fed high-fat diets, significant changes were observed in TG, CH, free cholesterol (FC), and phospholipid (PL) levels within the LDL fraction. The varied proportions of TG in wild-type mice and CH, FC, and PL in ApoE-/- mice were strikingly different in very low-density lipoproteins (VLDL), LDL, intermediate-density lipoprotein (IDL), and HDL. This comprehensive analysis expands our understanding of lipoprotein subfractions and the impacts of the APOE protein and high-fat diet in mouse models. The new testing method allows for a complete assessment of plasma lipids and their correlation with genetic background and diet in mice.

Dysregulation of choline metabolism and therapeutic potential of citicoline in Huntington's disease.

Huntington's disease (HD) is associated with dysregulated choline metabolism, but the underlying mechanisms remain unclear. This study investigated the expression of key enzymes in this pathway in R6/2 HD mice and human HD postmortem brain tissues. We further explored the therapeutic potential of modulating choline metabolism for HD. Both R6/2 mice and HD patients exhibited reduced expression of glycerophosphocholine phosphodiesterase 1 (GPCPD1), a key enzyme in choline metabolism, in the striatum and cortex. The striatum of R6/2 mice also showed decreased choline and phosphorylcholine, and increased glycerophosphocholine, suggesting disruption in choline metabolism due to GPCPD1 deficiency. Treatment with citicoline significantly improved motor performance, upregulated anti-apoptotic Bcl2 expression, and reduced oxidative stress marker malondialdehyde in both brain regions. Metabolomic analysis revealed partial restoration of disrupted metabolic patterns in the striatum and cortex following citicoline treatment. These findings strongly suggest the role of GPCPD1 deficiency in choline metabolism dysregulation in HD. The therapeutic potential of citicoline in R6/2 mice highlights the choline metabolic pathway as a promising target for future HD therapies.

Diagnostic Potential of Alternations of Bile Acid Profiles in the Plasma of Patients with Huntington's Disease.

Huntington's disease (HD) is characterized by progressive involuntary chorea movements and cognitive decline. Recent research indicates that metabolic disturbance may play a role in its pathogenesis. Bile acids, produced during cholesterol metabolism in the liver, have been linked to neurodegenerative conditions. This study investigated variations in plasma bile acid profiles among individuals with HD. Plasma levels of 16 primary and secondary bile acids and their conjugates were analyzed in 20 healthy controls and 33 HD patients, including 24 with symptoms (symHD) and 9 carriers in the presymptomatic stage (preHD). HD patients exhibited significantly higher levels of glycochenodeoxycholic acid (GCDCA) and glycoursodeoxycholic acid (GUDCA) compared to healthy controls. Conversely, isolithocholic acid levels were notably lower in the HD group. Neurotoxic bile acids (glycocholic acid (GCA) + glycodeoxycholic acid (GDCA) + GCDCA) were elevated in symHD patients, while levels of neuroprotective bile acids (ursodeoxycholic acid (UDCA) + GUDCA + tauroursodeoxycholic acid (TUDCA)) were higher in preHD carriers, indicating a compensatory response to early neuronal damage. These results underscore the importance of changes in plasma bile acid profiles in HD and their potential involvement in disease mechanisms. The identified bile acids (GCDCA, GUDCA, and isolithocholic acid) could potentially serve as markers to distinguish between HD stages and healthy individuals. Nonetheless, further research is warranted to fully understand the clinical implications of these findings and their potential as diagnostic or therapeutic tools for HD.

Combined Plasma DHA-Containing Phosphatidylcholine PCaa C38:6 and Tetradecanoyl-Carnitine as an Early Biomarker for Assessing the Mortality Risk among Sarcopenic Patients.

The coming of the hyper-aged society in Taiwan prompts us to investigate the relationship between the metabolic status of sarcopenic patients and their most adverse outcome-death. We studied the association between any plasma metabolites and the risk for mortality among older Taiwanese sarcopenic patients. We applied a targeted metabolomic approach to study the plasma metabolites of adults aged ≥65 years, and identified the metabolic signature predictive of the mortality of sarcopenic patients who died within a 5.5-year follow-up period. Thirty-five sarcopenic patients who died within the follow-up period (Dead cohort) had shown a specific plasma metabolic signature, as compared with 54 patients who were alive (Alive cohort). Only 10 of 116 non-sarcopenic individuals died during the same period. After multivariable adjustment, we found that sex, hypertension, tetradecanoyl-carnitine (C14-carnitine), and docosahexaenoic acid (DHA)-containing phosphatidylcholine diacyl (PCaa) C38:6 and C40:6 were important risk factors for the mortality of sarcopenic patients. Low PCaa C38:6 levels and high C14-carnitine levels correlated with an increased mortality risk; this was even the same for those patients with hypertension (HTN). Our findings suggest that plasma PCaa C38:6 and acylcarnitine C14-carnitine, when combined, can be a better early biomarker for evaluating the mortality risk of sarcopenia patients.

Oral fecal transplantation enriches Lachnospiraceae and butyrate to mitigate acute liver injury.

While fecal microbiota transplantation (FMT) shows promise in treating human diseases, oral capsule FMT is more accepted and accessible to patients. However, microbe selection in the upper gastrointestinal tract (UGIT) through oral administration remains unclear. Here, we demonstrate that short-term oral fecal gavage (OFG) alleviates acetaminophen-induced acute liver injury (AILI) in mice, regardless of the divergent effects of commensal gut microbes. Pasteurized fecal gavage yields similar therapeutic effects. OFG enriches gut Lachnospiraceae and butyrate compared to donor feces. Butyrate mitigates AILI-induced ferroptosis via AMPK-ULK1-p62 signaling to simultaneously induce mitophagy and Nrf2 antioxidant responses. Combined N-acetylcysteine and butyrate administration significantly improves AILI mouse survival rates. These observations indicate the significance of the UGIT in modulating the implanted fecal microbes through oral administration and its potential biological and clinical impacts. Our findings also highlight a possible strategy for applying microbial metabolites to treat acute liver injury.