Integrated metabolomics and proteomics analysis reveals energy metabolism disorders in the livers of sleep-deprived mice

Disruption of the peripheral biological clock may play a role in sleep deprivation-induced dysregulation of lipid metabolism in both the daytime and nighttime phases

STUDY OBJECTIVES

This study aimed to examine the effect of sleep deprivation (SD) on lipid metabolism or lipid metabolism regulation in the liver and white adipose tissue (WAT) during the light and dark phases and explored the possible mechanisms underlying the diurnal effect of SD on lipid metabolism associated with clock genes.

METHODS

Male C57BL/6J mice aged 2 months were deprived of sleep daily for 20 h for ten consecutive days with weakly forced locomotion. The body weights and food consumption levels of the SD and control mice were recorded, and the mice were then sacrificed at ZT (zeitgeber time) 2 and ZT 14. The peripheral clock genes, enzymes involved in fat synthesis and catabolism in the WAT, and melatonin signalling pathway-mediated lipid metabolism in the liver were assessed. Untargeted metabolomics and tandem mass tag (TMT) proteomics were used to identify differential lipid metabolism pathways in the liver.

RESULTS

Bodyweight gain and daily food consumption were dramatically elevated after SD. Profound disruptions in the diurnal regulation of the hepatic peripheral clock and enzymes involved in fat synthesis and catabolism in the WAT were observed, with a strong emphasis on hepatic lipid metabolic pathways, while melatonin signalling pathway-mediated lipid metabolism exhibited moderate changes.

CONCLUSIONS

In mice, ten consecutive days of SD increased body weight gain and daily food consumption. In addition, SD profoundly disrupted lipid metabolism in the WAT and liver during the light and dark periods. These diurnal changes may be related to disorders of the peripheral biological clock.

Energy strategy alteration, rather than toxicity itself, interferes with the population fluctuation of Brachionus plicatilis exposed to water-accommodated fractions (WAFs) of crude oil

Oil spills are reported to have conflicting impacts of either injury or resilience on zooplankton communities, and physiological plasticity is speculated to be the possible causative factor. But how? An explanation was sought by exposing the marine rotifer Brachionus plicatilis to a series of water-accommodated fractions (WAFs) of crude oil under controlled laboratory conditions, and population dynamics, which is the core issue for zooplankton facing external stress, were analyzed. The total hydrocarbon concentration of WAFs was quickly degraded from a concentration of 5.0 mg L-1 to half within 24 h and then remained stable. No acute lethality was observed; only motion inhibition was observed in the group treated with 10 %, 50 % and 100 % WAFs, which occurred simultaneously with inhibition of feeding and filtration. However, sublethal exposure to the WAFs concentration series presented stimulation impacts on reproduction and even the population of B. plicatilis. The negative correlation between motion and reproduction seemed to indicate that a shift in the distribution of individual energy toward reproduction rather than motion resulted in increased reproduction after exposure to WAFs. More evidence from transmission electron microscopy (TEM) revealed ultrastructural impairment in both the ovaries and cilia in each treated group, and imbalance in mitochondrial numbers was one of the distinct features of alteration. WAFs stress may alter the energy utilization and storage paradigm, as indicated by the significant elevation in glycogen and the significant decrease in lipid content after WAFs exposure. Further evidence from metabolomics analysis showed that WAFs stress increased the level of lipid metabolism and inhibited some of the pathways in glucose metabolism. Sublethal acute toxicity was observed only in the first 24 h with WAFs exposure, and an energy strategy consisting of changes in the utilization and storage paradigm and reallocation is responsible for the population resilience of B. plicatilis during oil spills.

Causality Investigation between Gut Microbiome and Sleep-Related Traits: A Bidirectional Two-Sample Mendelian Randomization Study

Recent research has highlighted associations between sleep and microbial taxa and pathways. However, the causal effect of these associations remains unknown. To investigate this, we performed a bidirectional two-sample Mendelian randomization (MR) analysis using summary statistics of genome-wide association studies (GWAS) from 412 gut microbiome traits (N = 7738) and GWAS studies from seven sleep-associated traits (N = 345,552 to 386,577). We employed multiple MR methods to assess causality, with Inverse Variance Weighted (IVW) as the primary method, alongside a Bonferroni correction ((p < 2.4 × 10-4) to determine significant causal associations. We further applied Cochran's Q statistical analysis, MR-Egger intercept, and Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) for heterogeneity and pleiotropy assessment. IVW estimates revealed 79 potential causal effects of microbial taxa and pathways on sleep-related traits and 45 inverse causal relationships, with over half related to pathways, emphasizing their significance. The results revealed two significant causal associations: genetically determined relative abundance of pentose phosphate decreased sleep duration (p = 9.00 × 10-5), and genetically determined increase in fatty acid level increased the ease of getting up in the morning (p = 8.06 × 10-5). Sensitivity analyses, including heterogeneity and pleiotropy tests, as well as a leave-one-out analysis of single nucleotide polymorphisms, confirmed the robustness of these relationships. This study explores the potential causal relationships between sleep and microbial taxa and pathways, offering novel insights into their complex interplay.

Emodin-8-O-β-D-glucopyranoside-induced hepatotoxicity and gender differences in zebrafish as revealed by integration of metabolomics and transcriptomics

BACKGROUND

Emodin-8-O-β-D-glucopyranoside (Em8G) is an active ingredient of traditional Chinese medicine Rhei Radix et Rhizoma and Polygonum multiflorum Thunb.. And it caused hepatotoxicity, while the underlying mechanism was not clear yet.

PURPOSE

We aimed to explore the detrimental effects of Em8G on the zebrafish liver through the metabolome and transcriptome integrated analysis.

STUDY DESIGN AND METHODS

In this study, zebrafish larvae were used in acute toxicity tests to reveal the hepatotoxicity of Em8G. Adult zebrafish were then used to evaluate the gender differences in hepatotoxicity induced by Em8G. Integration of transcriptomic and metabolomic analysis was used further to explore the molecular mechanisms underlying gender differences in hepatotoxicity.

RESULTS

Our results showed that under non-lethal concentration exposure conditions, hepatotoxicity was observed in Em8G-treated zebrafish larvae, including changes in liver transmittance, liver area, hepatocyte apoptosis and hepatocyte vacuolation. Male adult zebrafish displayed a higher Em8G-induced hepatotoxicity than female zebrafish, as demonstrated by the higher mortality and histopathological alterations. The results of transcriptomics combined with metabolomics showed that Em8G mainly affected carbohydrate metabolism (such as TCA cycle) in male zebrafish and amino acid metabolism (such as arginine and proline metabolism) in females, suggesting that the difference of energy metabolism disorder may be the potential mechanism of male and female liver toxicity induced by Em8G.

CONCLUSIONS

This study provided the direct evidence for the hepatotoxicity of Em8G to zebrafish models in vivo, and brought a new insight into the molecular mechanisms of Em8G hepatotoxicity, which can guide the rational application of this phytotoxin. In addition, our findings revealed gender differences in the hepatotoxicity of Em8G to zebrafish, which is related to energy metabolism and provided a methodological reference for evaluating hepatotoxic drugs with gender differences.

Systematic Metabolic Profiling of Mice with Sleep-Deprivation

Adequate sleep is essential for the biological maintenance of physical energy. Lack of sleep can affect thinking, lead to emotional anxiety, reduce immunity, and interfere with endocrine and metabolic processes, leading to disease. Previous studies have focused on long-term sleep deprivation and the risk of cancer, heart disease, diabetes, and obesity. However, systematic metabolomics analyses of blood, heart, liver, spleen, kidney, brown adipose tissue, and fecal granules have not been performed. This study aims to systematically assess the metabolic changes in the target organs caused by sleep deprivation in vivo, to search for differential metabolites and the involved metabolic pathways, to further understand the impact of sleep deprivation on health, and to provide strong evidence for the need for early intervention.

Exploration of the underlying mechanisms of isoniazid/rifampicin-induced liver injury in mice using an integrated proteomics and metabolomics approach

The hepatotoxic mechanism resulting from coadministration of isoniazid (INH) and rifampicin (RIF) are complex and studies remain inconclusive. To systematically explore the underlying mechanisms, an integrated mass-based untargeted metabolomics and label-free quantitative proteomics approach was used to clarify the mechanism of INH/RIF-induced liver injury. Thirty male mice were randomly divided into three groups: control (receiving orally administered vehicle solution), INH (150 mg/kg) + RIF (300 mg/kg) orally administered for either 7 or 14 days, respectively. Serum was collected for the analysis of biochemical parameters and liver samples were obtained for mass spectrum-based proteomics, metabolomics, and lipidomics analysis. Overall, 511 proteins, 31 metabolites, and 23 lipids were dysregulated and identified, and disordered biological pathways were identified. The network of integrated multiomics showed that glucose, lipid, and amino acid metabolism as well as energy metabolism were mainly dysregulated and led to oxidative stress, inflammation, liver steatosis, and cell death induced by INH and RIF. Coadministration of INH and RIF can induce liver injury by oxidative stress, inflammation, liver steatosis, and cell death, and the reduction in glutathione levels may play a critical role in these systematic changes and warrants further study.

Melatonin protects against body weight gain induced by sleep deprivation in mice

Sleep deprivation is an epidemic phenomenon in modern society. Lack of sleep has been shown to result in metabolic and endocrine disorders that predispose to obesity and other chronic metabolic diseases. Melatonin is a sleep-related neurohormone and affected by the circadian rhythm and light/dark cycles. Melatonin has recently been used to ameliorate diet-induced or night light-induced energy metabolic imbalance. However, the effect of melatonin on sleep deprivation-induced obesity has been poorly characterized. This study focuses on the protective effects of melatonin on lipid metabolism and body weight homeostasis in sleep-deprived mice. Mice subjected to sleep deprivation had significantly decreased plasma melatonin content and increased food intake and body weight gain compared to that of control. Meanwhile, the transcription factor PPARγ protein in liver increased, but there were no significant changes in hepatic circadian proteins BMAL1 and REV-ERBα after 10 consecutive days of sleep deprivation. Moreover, melatonin supplementation increased liver AMPKα/PPARα signaling pathway activity, which leads to lipid catabolism and reduced fat accumulation. These findings suggested that melatonin may be a potential agent for protecting against sleep deprivation-induced obesity.

Torularhodin Alleviates Hepatic Dyslipidemia and Inflammations in High-Fat Diet-Induced Obese Mice via PPARα Signaling Pathway

Torularhodin is a β-carotene-like compound from Sporidiobolus pararoseus, and its protective effect against high-fat diet (HFD)-induced hepatic dyslipidemia and inflammation was investigated. Compared to mice of C57BL/6J fed on HFD, the addition of Torularhodin into the HFD (HFD-T) significantly reduced body weight, serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), and the inflammatory mediators of TNF-α, IL-6, IL-1β, and lipopolysaccharide (LPS). A significant increase of high-density lipoprotein cholesterol (HDL-c), which is beneficial to cholesterol clearance, was also observed in HFD-T group. Proteomic analysis showed HDL-C-c is highly correlated with proteins (e.g., CPT1A and CYP7A1) involved in lipid β-oxidation and bile acid synthesis, whereas the other phenotypic parameters (TC, TG, LDL, and inflammatory cytokines) are highly associated with proteins (e.g., SLC27A4) involved in lipid-uptake. The up-regulated anti-inflammation proteins FAS, BAX, ICAM1, OCLN, GSTP1, FAF1, LRP1, APEX1, ROCK1, MANF, STAT3, and INSR and down-regulated pro-inflammatory proteins OPTN, PTK2B, FADD, MIF, CASP3, YAP1, DNM1L, and NAMPT not only demonstrate the occurrence of HFD-induced hepatic inflammation, but also prove the anti-inflammatory property of Torularhodin. KEGG signaling pathway analysis revealed that the PPARα signaling pathway is likely fundamental to the health function of Torularhodin through up-regulating genes related to fatty acid β-oxidation, cholesterol excretion, HDL-Cc formation, and anti-inflammation. Torularhodin, as a new food resource, may act as a therapeutic agent to prevent hepatic dyslipidemia and related inflammation for improved health.

Urine Proteome in Distinguishing Hepatic Steatosis in Patients with Metabolic-Associated Fatty Liver Disease

Background: In patients with metabolic-associated fatty liver disease (MAFLD), hepatic steatosis is the first step of diagnosis, and it is a risk predictor that independently predicts insulin resistance, cardiovascular risk, and mortality. Urine biomarkers have the advantage of being less complex, with a lower dynamic range and fewer technical challenges, in comparison to blood biomarkers. Methods: Hepatic steatosis was measured by magnetic resonance imaging (MRI), which measured the proton density fat fraction (MRI-PDFF). Mild hepatic steatosis was defined as MRI-PDFF 5−10% and severe hepatic steatosis was defined as MRI-PDFF > 10%. Results: MAFLD patients with any kidney diseases were excluded. There were 53 proteins identified by mass spectrometry with significantly different expressions among the healthy control, mild steatosis, and severe steatosis patients. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of these significantly changed urinary molecular features correlated with the liver, resulting in the dysregulation of carbohydrate derivative/catabolic/glycosaminoglycan/metabolic processes, insulin-like growth factor receptor levels, inflammatory responses, the PI3K−Akt signaling pathway, and cholesterol metabolism. Urine alpha-1-acid glycoprotein 1 (ORM1) and ceruloplasmin showed the most significant correlation with the clinical parameters of MAFLD status, including liver fat content, fibrosis, ALT, triglycerides, glucose, HOMA-IR, and C-reactive protein. According to ELISA and western blot (30 urine samples, normalized to urine creatinine), ceruloplasmin (ROC 0.78, p = 0.034) and ORM1 (ROC 0.87, p = 0.005) showed moderate diagnostic accuracy in distinguishing mild steatosis from healthy controls. Ceruloplasmin (ROC 0.79, p = 0.028) and ORM1 (ROC 0.81, p = 0.019) also showed moderate diagnostic accuracy in distinguishing severe steatosis from mild steatosis. Conclusions: Ceruloplasmin and ORM1 are potential biomarkers in distinguishing mild and severe steatosis in MAFLD patients.

Potential effects of shift work on skin autoimmune diseases

Shift work is associated with systemic chronic inflammation, impaired host and tumor defense and dysregulated immune responses to harmless antigens such as allergens or auto-antigens. Thus, shift workers are at higher risk to develop a systemic autoimmune disease and circadian disruption with sleep impairment seem to be the key underlying mechanisms. Presumably, disturbances of the sleep-wake cycle also drive skin-specific autoimmune diseases, but epidemiological and experimental evidence so far is scarce. This review summarizes the effects of shift work, circadian misalignment, poor sleep, and the effect of potential hormonal mediators such as stress mediators or melatonin on skin barrier functions and on innate and adaptive skin immunity. Human studies as well as animal models were considered. We will also address advantages and potential pitfalls in animal models of shift work, and possible confounders that could drive skin autoimmune diseases in shift workers such as adverse lifestyle habits and psychosocial influences. Finally, we will outline feasible countermeasures that may reduce the risk of systemic and skin autoimmunity in shift workers, as well as treatment options and highlight outstanding questions that should be addressed in future studies.