Nontarget metabolomics profiling of neuromyelitis optica spectrum disorder

Tissue-based metabolomics reveals metabolic signatures and major metabolic pathways of gastric cancer with help of transcriptomic data from TCGA

PURPOSE

The aim of the present study was to screen differential metabolites of gastric cancer (GC) and identify the key metabolic pathways of GC.

METHODS

GC (n=28) and matched paracancerous (PC) tissues were collected, and LC-MS/MS analysis were performed to detect metabolites of GC and PC tissues. Metabolite pathways based on differential metabolites were enriched by MetaboAnalyst, and genes related to metabolite pathways were identified using the KEGGREST function of the R software package. Transcriptomics data from The Cancer Genome Atlas (TCGA) was analyzed to obtain differentially expressed genes (DEGs) of GC. Overlapping genes were acquired from metabonimics and transcriptomics data. Pathway enrichment analysis was performed using String. The protein expression of genes was validated by the Human Protein Atlas (HPA) database.

RESULTS

A total of 325 key metabolites were identified, 111 of which were differentially expressed between the GC and PC groups. Seven metabolite pathways enriched by MetaboAnalyst were chosen, and 361 genes were identified by KEGGREST. A total of 2831 DEGs were identified from the TCGA cohort. Of these, 1317 were down-regulated, and 1636 were up-regulated. Twenty-two overlapping genes were identified between genes related to metabolism and DEGs. Glycerophospholipid (GPL) metabolism is likely associated with GC, of which AGPAT9 and ETNPPL showed lower expressed in GC tissues.

CONCLUSIONS

We investigated the tissue-based metabolomics profile of GC, and several differential metabolites were identified. GPL metabolism may affect on progression of GC.

Sex-dependent changes in the skin mucus metabolome of discus fish (Symphysodon haraldi) during biparental care

Discus fish Symphysodon spp. employs an unusual parental care where fry feed on parental skin mucus after hatching. Here, we investigated the mucus metabolites of parental and non-parental discus by using non-targeted metabolomics. Statistical analysis of the skin mucus metabolome revealed sex-dependent changes of mucus between parental and non-parental discus, as well as sex-specific differences between parental fish. Differential metabolites reflected that mucus of both parents was rich in prostaglandin A1, but only male contained more oligosaccharides (gentiobiose and D-melezitose) and nucleotides (guanine and cytosine), and only female detected more thymine. Moreover, differential metabolites revealed the metabolic status of parental discus, including the inhibition of biosynthesis of amino acids, e.g., L-phenylalanine (parents), L-aspartic acid (female) and taurine (male) and the activation of metabolism of these amino acids; the increase of metabolism of fatty acids such as α-Linolenic acid (female), arachidonic acid (female) and linoleic acid (male); the perturbation of metabolism of carbohydrate and energy including starch and sucrose metabolism (parents), ascorbate and aldarate metabolism (parents), amino sugar and nucleotide sugar metabolism (female), pentose and glucuronate interconversions (male) and glyoxylate and dicarboxylate metabolism (male). These results might suggest sex-specific metabolic changes in the skin mucus of discus fish during parental care. SIGNIFICANCE: We detected the low-molecular-weight compounds present in the parental mucus of discus fish evolving for offspring and revealed the possible metabolic changes associated with parental care. These results are helpful to gain further insights on the functional and regulatory aspects of skin mucus of discus during parental care.