Effects of L-Ornithine on Metabolic Processes of the Urea Cycle in Human Keratinocytes

House ammonia exposure causes alterations in microbiota, transcriptome, and metabolome of rabbits

Introduction

Pollutant gas emissions in the current production system of the livestock industry have negative influences on environment as well as the health of farm staffs and animals. Although ammonia (NH3) is considered as the primary and harmful gas pollutant in the rabbit farm, less investigation has performed to determine the toxic effects of house ammonia exposure on rabbit in the commercial confined barn.

Methods

In this study, we performed multi-omics analysis on rabbits exposed to high and low concentration of house ammonia under similar environmental conditions to unravel the alterations in nasal and colonic microbiota, pulmonary and colonic gene expression, and muscular metabolic profile.

Results and discussion

The results showed that house ammonia exposure notably affected microbial structure, composition, and functional capacity in both nasal and colon, which may impact on local immune responses and inflammatory processes. Transcriptome analysis indicated that genes related to cell death (MCL1, TMBIM6, HSPB1, and CD74) and immune response (CDC42, LAMTOR5, VAMP8, and CTSB) were differentially expressed in the lung, and colonic genes associated with redox state (CAT, SELENBP1, GLUD1, and ALDH1A1) were significantly up-regulated. Several key differentially abundant metabolites such as L-glutamic acid, L-glutamine, L-ornithine, oxoglutaric acid, and isocitric acid were identified in muscle metabolome, which could denote house ammonia exposure perturbed amino acids, nucleotides, and energy metabolism. In addition, the widespread and strong inter-system interplay were uncovered in the integrative correlation network, and central features were confirmed by in vitro experiments. Our findings disclose the comprehensive evidence for the deleterious effects of house ammonia exposure on rabbit and provide valuable information for understanding the underlying impairment mechanisms.

Characterizing amino-acid biosignatures amongst individuals with schizophrenia: a case-control study

Amino acids and derivatives participate in the biosynthesis and downstream effects of numerous neurotransmitters. Variations in specific amino acids have been implicated in the pathophysiology of schizophrenia. Herein, we sought to compare levels of amino acids and derivatives between subjects with schizophrenia and healthy controls (HC). Two hundred and eight subjects with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria (DSM-IV)-defined schizophrenia and 175 age- and sex-matched HC were enrolled. The levels of twenty-five amino acids and seven related derivatives were measured in plasma samples using hydrophilic interaction liquid chromatography (HILIC) liquid chromatography-tandem mass spectrometry (LC-MS). After controlling for age, sex and body mass index (BMI), four amino acids and derivatives (i.e., cysteine, GABA, glutamine and sarcosine) were observed to be higher in the schizophrenia group when compared with HC; seven amino acids and derivatives were lower in the schizophrenia group (i.e., arginine, L-ornithine, threonine, taurine, tryptophan, methylcysteine, and kynurenine). Statistically significant differences in plasma amino-acid profiles between subjects with first-episode vs. recurrent schizophrenia for aspartate and glutamine were also demonstrated using generalized linear models controlling for age, sex, and BMI. The differences in amino acids and derivatives among individuals with schizophrenia when compared to HC may represent underlying pathophysiology, including but not limited to dysfunctional proteinogenic processes, alterations in excitatory and inhibitory neurotransmission, changes in ammonia metabolism and the urea cycle. Taken together, amino-acid profiling may provide a novel stratification approach among individuals with schizophrenia.