The arachidonic acid metabolome reveals elevation of prostaglandin E2 biosynthesis in colorectal cancer.

Arachidonic acid metabolites are a family of bioactive lipids derived from membrane phospholipids. They are involved in cancer progression, but arachidonic acid metabolite profiles and their related biosynthetic pathways remain uncertain in colorectal cancer (CRC). To compare the arachidonic acid metabolite profiles between CRC patients and healthy controls, quantification was performed using a liquid chromatography-mass spectrometry-based analysis of serum and tissue samples. Metabolomics analysis delineated the distinct oxidized lipids in CRC patients and healthy controls. Prostaglandin (PGE2)-derived metabolites were increased, suggesting that the PGE2 biosynthetic pathway was upregulated in CRC. The qRT-PCR and immunohistochemistry analyses showed that the expression level of PGE2 synthases, the key protein of PGE2 biosynthesis, was upregulated in CRC and positively correlated with the CD68+ macrophage density and CRC development. Our study indicates that the PGE2 biosynthetic pathway is associated with macrophage infiltration and progression of CRC tumors.

Butyrate promotes C2C12 myoblast proliferation by activating ERK/MAPK pathway.

Sarcopenia has garnered considerable interest in recent years as ageing-associated diseases constitute a significant worldwide public health burden. Nutritional supplements have received much attention as potential tools for managing sarcopenia. However, the specific nutrients responsible are still under-investigated. In the current study, we first determined the levels of short chain fatty acids (SCFAs) and intestinal flora in the feces of elderly sarcopenia subjects and elderly healthy individuals by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Then cell viability detection, flow cytometry and transcriptome analysis were adopted to experimentally evaluate the effect and the underlying mechanism of SCFA on C2C12 cells proliferation in vitro. The results suggested that patients with sarcopenia exhibited decreased levels of butyrate. And butyrate may stimulate C2C12 myocyte proliferation via promoting G1/S cell cycle transition. Transcriptomic analyses pointed to upregulation of the Mitogen-activated protein kinase (MAPK) signaling pathway in butyrate-treated cells. In addition, the above proliferative phenotypes could be suppressed by the combination of ERK/MAPK inhibitor. A combined transcriptomic and metabolomic approach was applied in our study to investigate the potential effect of microbiota-derived butyrate yield on muscular proliferation which may indicate a protective effect of nutritional supplements.

Diagnostic value of serum sphingolipids in patients with colorectal cancer.

Background: Abnormal lipid metabolism affects the regulation of tumor progression, though use of serum lipids and sphingolipids for disease progression identification is uncertain. Methods: Serum samples from 51 healthy volunteers and 76 patients were collected and analyzed by liquid chromatography tandem mass spectrometry. Results: Levels of serum total cholesterol and high-density lipoprotein were significantly lower in colorectal cancer patients. Multivariate analysis demonstrated distinct sphingolipid profiles between healthy individuals and patients. Of 106 sphingolipids, 15 metabolites that showed statistical significance were selected, and receiver operating characteristic analysis of these metabolites yielded an area under the curve of 0.868 to 0.9 by machine learning algorithms for distinguishing colorectal cancer from a healthy status. Conclusions: Healthy individuals, polyps patients and colorectal cancer patients have different serum sphingolipid signatures. Serum sphingolipids might be used as biomarkers for early detection or prediction of colorectal cancer.

Precision N-Glycoproteomic Profiling of Murine Peritoneal Macrophages After Different Stimulations.

Macrophages are important immune cells that participate in both innate and adaptive immune responses, such as phagocytosis, recognition of molecular patterns, and activation of the immune response. In this study, murine peritoneal macrophages were isolated and then activated by LPS, HSV and VSV. Integrative proteomic and precision N-glycoproteomic profiling were conducted to assess the underlying macrophage activation. We identified a total of 587 glycoproteins, including 1239 glycopeptides, 526 monosaccharide components, and 8326 intact glycopeptides in glycoproteomics, as well as a total of 4496 proteins identified in proteomic analysis. These glycoproteins are widely involved in important biological processes, such as antigen presentation, cytokine production and glycosylation progression. Under the stimulation of the different pathogens, glycoproteins showed a dramatic change. We found that receptors in the Toll-like receptor pathway, such as Tlr2 and CD14, were increased under LPS and HSV stimulation. Glycosylation of those proteins was proven to influence their subcellular locations.

Computational and Mass Spectrometry-Based Approach Identify Deleterious Non-Synonymous Single Nucleotide Polymorphisms (nsSNPs) in JMJD6.

The jumonji domain-containing protein 6 (JMJD6) gene catalyzes the arginine demethylation and lysine hydroxylation of histone and a growing list of its known substrate molecules, including p53 and U2AF65, suggesting a possible role in mRNA splicing and transcription in cancer progression. Mass spectrometry-based technology offers the opportunity to detect SNP variants accurately and effectively. In our study, we conducted a combined computational and filtration workflow to predict the nonsynonymous single nucleotide polymorphisms (nsSNPs) present in JMJD6, followed by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis and validation. The computational approaches SIFT, PolyPhen-2, SNAP, I-Mutant 2.0, PhD-SNP, PANTHER, and SNPS&GO were integrated to screen out the predicted damaging/deleterious nsSNPs. Through the three-dimensional structure of JMJD6, H187R (rs1159480887) was selected as a candidate for validation. The validation experiments showed that the mutation of this nsSNP in JMJD6 obviously affected mRNA splicing or the transcription of downstream genes through the reduced lysyl-hydroxylase activity of its substrates, U2AF65 and p53, further indicating the accuracy of this prediction method. This research provides an effective computational workflow for researchers with an opportunity to select prominent deleterious nsSNPs and, thus, remains promising for examining the dysfunction of proteins.

Metabolomics analysis provides new insights into the medicinal value of flavonoids in tobacco leaves.

Tobacco is a traditional Chinese medicine containing a variety of biologically active substances. In addition to being used to make cigarettes, tobacco is also a vastly underdeveloped medicinal resource. In order to identify and clarify the biological activities and medicinal value of tobacco leaves, the metabolomes of tobacco leaves were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) based on multiple reaction monitoring (MRM). In total, 1169 metabolites were identified and quantified. The results showed that the metabolic profiles of the tobacco cultivars K326 and Yun87 are similar to each other but different from that of Hongda. Moreover, the curing process affects the metabolic profiles of tobacco leaves. Flavonoids are the largest class of metabolites in tobacco leaves. Flavonoids have multiple biological functions; for example, they can promote or inhibit inflammation. We found that quercetin provides anti-inflammatory activity by inhibiting the il-1ß mRNA expression, while glycitin and neohesperidin can promote il-1ß and il-6 production. Our results provide in-depth insights into the medical uses and biological mechanisms of tobacco leaves.