Amino Acids最新文献

The number of colorectal cancer (CRC) patients is steadily growing worldwide, particularly in developing nations. Nonetheless, recent advances in early detection studies and therapy alternatives have reduced CRC mortality in affluent countries, despite rising incidence. Gut microbiota and their metabolites may contribute to tumor growth and reduced therapeutic efficacy. This preliminary study sought to uncover metabolic fingerprints in colorectal cancer patients. It also emphasizes the correlation between the gut microbiome, microbial metabolism, and altered metabolites in CRC. In this study, stool samples from 20 CRC patients and matched healthy controls were enrolled. Untargeted metabolomics approach based on an ultra-high-performance liquid chromatography high-resolution mass spectrometry (UHPLC-MS/MS) were applied. Statistical approaches, pathway enrichment analysis, and network analysis were employed to unleash CRC perturbed metabolic pathways and putative biomarkers. The study identified a distinct manually curated metabolite profile that is substantially linked to CRC. The steroidogenesis, aspartate, tryptophan (Trp), and urea cycle were the most significant pathways that concurrently contributed to CRC.Prominently, among other pathways, Trp metabolism was identified as a critical pathway, indicating a possible connection between the development of CRC and gut microbiota. In a nutshell the notable resulted metabolites reveal auspicious biomarkers for the initial diagnosis as well as surveilling of CRC progression. This preliminary study highlights the potential involvement that gut bacteria may contribute in CRC patients. Further investigation into the composition of the gut microbiome associated with this metabolic profile may lead to the identification of novel biomarkers for early detection and possible targets for treatment.

Taurine is an amino acid with several physiological functions and has been shown to be involved in the anti-tumor of human nasopharyngeal carcinoma (NPC) cells. However, the role of taurine metabolism-related genes (TMRGs) in NPC has not been reported. We integrated data from the Genecards, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Expression Omnibus(GEO) databases to identify differentially expressed genes associated with taurine metabolism in NPC patients. Gene Ontology (GO) and KEGG analyses were conducted to investigate the underlying mechanisms. Subsequently, Cox regression and Least Absolute Shrinkage and Selection Operator (LASSO) regression analyses were performed to construct a taurine metabolism-related prognostic signature. Survival, medication sensitivity, and immunological microenvironment evaluations were performed to assess the prognostic utility of the model. Finally, immunohistochemistry (IHC) experiments were performed to validate the model’s prognostic reliability. In addition, we further verified the reliability of our research results through molecular docking and single-cell sequencing. Our prognostic model was based on three pivotal TMRGs (ABCB1, GORASP1, and EZH2). Functional analysis revealed a strong association between TMRGs and miRNAs in cancer. Notably, increased risk scores correlated with worsening tumor malignancy and prognosis. Significant disparities in immune microenvironment, immune checkpoints, and drug sensitivity were observed between the high- and low-risk groups. The protein expression patterns of the selected genes in clinical NPC samples were validated using immunohistochemistry. Molecular docking verified the interaction between these three core genes and taurine, which was further supported by single-cell sequencing showing significant expression variation among different cell clusters in NPC. We had elucidated the functions, therapeutic potential, and prognostic significance of three key genes related to taurine metabolism in NPC through multidimensional research and experimental validation. This research provided valuable insights and potential avenues for improved NPC management.

Excellent biomarkers for predicting survival or therapeutic targets are still lacking in gastric cancer (GC), which is one of the most common causes of cancer-related death worldwide. Ring finger protein, transmembrane 2 (RNFT2), which has been reported to be involved in proteolytic process, but how it functions in tumors is rarely investigated. In the present study, we explored the biological property of RNFT2 in GC, we found that RNFT2 was significantly upregulated in GC, and could serve as a tumor marker to predict prognosis. A series of in vitro cell function experiments were performed, we found that knockdown of RNFT2 expression in GC cells could inhibit cell invasion, migration and proliferation. Besides, in vivo experiments also showed that silencing RNFT2 expression in gastric cancer cells significantly reduced tumor size. Furthermore, through gene set enrichment analysis (GSEA) and immunoblotting studies, we observed that RNFT2 might influence the proliferation, invasion and migration of GC cells through the mTORC1 signaling pathway. In summary, our results clarified the carcinogenic role of RNFT2 in GC progression, provided inspiration to further understand the molecular mechanism of GC and made RNFT2 as a potential target for GC diagnosis and therapy.

Mitochondria play a pivotal role in energy production, metabolism, and cellular signaling, serving as key regulators of cellular functions, including differentiation and tissue-specific adaptation. The interplay between mitochondria and the nucleus is crucial for coordinating these processes, particularly through the supply of metabolites for epigenetic modifications that facilitate nuclear-mitochondrial interactions. To investigate tissue-specific mitochondrial adaptations at the molecular level, we conducted RNA sequencing data analyses of kidney, heart, brain, and ovary tissues of female buffaloes, focusing on variations in mitochondrial gene expression related to amino acid metabolism. Our analysis identified 82 nuclear-encoded mitochondrial transcripts involved in amino acid metabolism, with significant differential expression patterns across all tissues. Notably, the heart, brain, and kidney—tissues with higher energy demands—exhibited elevated expression levels compared to the ovary. The kidney displayed unique gene expression patterns, characterized by up-regulation of genes involved in glyoxylate metabolism and amino acid catabolism. In contrast, comparative analysis of the heart and kidney versus the brain revealed shared up-regulation of genes associated with fatty acid oxidation. Gene ontology and KEGG pathway analyses confirmed the enrichment of genes in pathways related to amino acid degradation and metabolism. These findings highlight the tissue-specific regulation of mitochondrial gene expression linked to amino acid metabolism, reflecting mitochondrial adaptations to the distinct metabolic and energy requirements of different tissues in buffalo. Importantly, our results underscore the relevance of mitochondrial adaptations not only for livestock health but also for understanding metabolic disorders in humans. By elucidating the molecular mechanisms of mitochondrial function and their tissue-specific variations, this study provides insights that could inform breeding strategies for enhanced livestock productivity and contribute to therapeutic approaches for human metabolic diseases. Thus, our findings illustrate how mitochondria are specialized in a tissue-specific manner to optimize amino acid utilization and maintain cellular homeostasis, with implications for both animal welfare and human health.

Observational studies have linked uric acid (UA) levels and kidney disease to amino acid homeostasis, but the causal relationship is unclear. This study aims to determine if elevated UA affects amino acid levels and whether amino acids mediate this relationship, focusing on the causal links between UA, circulating amino acids, and kidney disease. Methods: This study utilized Uox-KO mice as a hyperuricemia model, assessed renal injury through blood biochemistry and pathology, analyzed serum amino acid changes via targeted amino acidomics, and employed Mendelian randomization to investigate the causal links between uric acid, amino acids, and renal disease. Results: Hyperuricemia Uox-KO mice have significantly higher serum UA and renal impairment markers, with histopathological analysis showing extensive renal tissue damage. Changes in amino acid balance were found in the mice's serum, with key metabolites like alanine, isoleucine, leucine, aspartic acid, cysteine, glutamate, and glycine potentially influencing UA pathophysiology. Genetically predicted UA was positively correlated with chronic renal failure (CRF) and blood urea nitrogen(BUN) levels and negatively with serum cystatin C (eGFRcys) and serum creatinine (eGFRcrea). Alanine (Ala) mediated the effect of UA on elevated CRF and BUN risk, accounting for 4.5% of the UA-CRF relationship and 14.4% of the UA-BUN association. Conclusion: In hyperuricemia mice, serum amino acids undergo metabolic changes. Genetically predicted UA levels are positively linked to CRF and BUN, but negatively linked to eGFRcys and eGFRcrea. Ala mediates UA's effect on CRF and BUN risk, indicating Ala could be a target for preventing renal diseases caused by hyperuricemia.

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Amyloid fibers are implicated in numerous diseases, making their study crucial for identifying effective therapeutic compounds. This research highlights the ability of L-tyrosine to inhibit the formation of amyloid fibers in human lysozyme. At a 1:1 molar ratio under physiological conditions (pH 7.4, 37 °C), L-tyrosine significantly reduces amyloid fiber formation, as evidenced by a decrease in thioflavin T fluorescence. Differential scanning calorimetry (DSC) shows a major energy requirement for temperature denaturation when the lysozyme is in the presence of L-tyrosine. Additionally, chemical denaturation experiments reveal a shift in the intrinsic fluorescence spectrum of lysozyme in the presence of L-tyrosine, indicating a direct interaction. Computational docking studies with Molecular Operating Environment (MOE) further confirm that L-tyrosine binds effectively, exhibiting similar binding energies to those of the natural substrate. This study underscores L-tyrosine’s potential as a strong inhibitor of amyloid fiber formation, demonstrating its stabilizing effect on lysozyme and its promise in therapeutic applications.

The main objective of this experiment was to study the metabolism of arginine in juvenile largemouth bass (Micropterus salmoides). A total of 300 healthy fish (average weight of 25 ± 0.5 g) were randomly assigned to ten groups. Experimental fish were orally administered or intraperitoneally injected with 0.9% sodium chloride, arginine, arginine-aspartate, citrulline, and glutamate solutions, respectively. They were euthanized at 10, 30, 60, 120, and 240 min after oral administration or intraperitoneal injection, and various tissue samples were subsequently collected for analysis. The results revealed that serum ornithine and citrulline concentrations of largemouth bass were significantly increased by oral administration of arginine or arginine-aspartate (P < 0.05). Intraperitoneal injection of arginine or arginine-aspartate solution significantly elevated the concentrations of ornithine and citrulline in the serum, liver, kidney, and muscles (P < 0.05). The concentrations of citrulline, ornithine, and arginine in serum and muscle increased significantly at 4 h after intraperitoneal injection of glutamate (P < 0.05). Intraperitoneal injection of citrulline significantly increased the concentrations of ornithine and arginine in the serum and muscles (P < 0.05). The research findings demonstrate that both free and small peptide forms of arginine were rapidly degraded to ornithine due to the high arginase activity in various tissues of largemouth bass. Additionally, the pathway of synthesizing citrulline from glutamate and then arginine from citrulline may exist in largemouth bass, but the exact location of this synthesis process may differ from that found in mammals.

Compound-specific stable carbon isotope analysis of amino acids (CSIA-AA) is widely used in ecological studies to analyze food-webs and is gaining use in archaeology for investigating past diets. However, its use in reconstructing breastfeeding and weaning practices is not fully understood. This study evaluates the efficacy of stable carbon isotope analysis of amino acids in early life diet reconstruction by analyzing keratin from fingernail samples of three mother-infant pairs during late gestation and early postpartum periods. Our results show that stable carbon isotope ratios (δ¹³C) of glycine, and to a lesser extent glutamate, effectively trace the onset of exclusive breastfeeding and the end of weaning in infants. We propose that glycine’s ‘conditionally essential’ metabolic pathway during infancy allows it to reflect maternal glycine δ¹³C, indicating breastmilk consumption. Subtle changes in glutamate δ¹³C likely result from its ‘non-essential’ status. Additionally, δ¹³C values of glycine and glutamate indicate maternal physiological and pathological stress due to catabolic effects such as gluconeogenesis. These findings have significant implications for ecological and archaeological research using CSIA-AA for dietary reconstructions. They highlight the need to understand how metabolic pathways affecting δ¹³C of amino acids may change over an individual’s lifespan or be altered due to various forms of stress.