Selective Hepatic Cbs Knockout Aggravates Liver Damage, Endothelial Dysfunction and ROS Stress in Mice Fed a Western Diet

CCAAT/Enhancer-Binding Protein Beta Nitration Participates in Hyperhomocysteinemia-Induced Cardiomyocyte Autophagic Flux Blockage by Inhibiting Transcription Factor EB Transcription

Aims: Autophagy is a protective mechanism of cardiomyocytes. Hyperhomocysteinemia (HHcy) elevates oxidative and nitrosative stress levels, leading to an abnormal increase in nitration protein, possibly leading to abnormal autophagy regulation in cardiomyocytes. However, the regulatory effect of HHcy on autophagy at the post-translational modification level is still unclear. Here, we aimed to explore the regulatory mechanism of HHcy on transcription factor EB (TFEB) and nitration of CCAAT/enhancer-binding protein beta (C/EBPβ), a transcriptional repressor of Tfeb, on autophagy in cardiomyocytes. Results: In this study, we established the HHcy rat model by feeding a 2.5% (w/w) methionine diet. The nitration level of C/EBPβ was increased in HHcy, which promoted the entry of C/EBPβ into the nucleus, enhanced the transcriptional suppressive effect of C/EBPβ on Tfeb, and induced insufficient autophagy in cardiomyocytes. Furthermore, we confirmed that the Tyr 274 site of C/EBPβ could undergo nitration induced by HHcy. Once C/EBPβ was nitrated on the Tyr 274 site, the nuclear translocation of C/EBPβ and transcription suppressor function of C/EBPβ on Tfeb were enhanced. Innovation and Conclusion: We find that C/EBPβ is a transcriptional repressor of Tfeb, and HHcy induces the nitration at the Tyr 274 site of C/EBPβ, leading to autophagic flux blockage in cardiomyocytes. These data indicated that nitrated C/EBPβ might be a potential therapeutic target against HHcy-induced autophagy insufficiency of cardiomyocytes. Antioxid. Redox Signal. 42, 165-183.

Rodent model of metabolic dysfunction-associated fatty liver disease: a systematic review

Although significant progress has been made in developing preclinical models for metabolic dysfunction-associated steatotic liver disease (MASLD), few have encapsulated the essential biological and clinical outcome elements reflective of the human condition. We conducted a comprehensive literature review of English-language original research articles published from 1990 to 2023, sourced from PubMed, Embase, and Web of Science, aiming to collate studies that provided a comparative analysis of physiological, metabolic, and hepatic histological characteristics between MASLD models and control groups. The establishment of a robust metabolic dysfunction-associated steatotic liver rodent model hinges on various factors, including animal species and strains, sex, induction agents and methodologies, and the duration of induction. Through this review, we aim to guide researchers in selecting suitable induction methods and animal species for constructing preclinical models aligned with their specific research objectives and laboratory conditions. Future studies should strive to develop simple, reliable, and reproducible models, considering the model's sensitivity to factors such as light-dark cycles, housing conditions, and environmental temperature. Additionally, the potential of diverse in vitro models, including 3D models and liver organ technology, warrants further exploration as valuable tools for unraveling the cellular mechanisms underlying fatty liver disease.

Hypoxia-inducible lipid droplet-associated protein (HILPDA) and cystathionine β-synthase (CBS) co-contribute to protecting intestinal epithelial cells from Staphylococcus aureus via regulating lipid droplets formation

Despite Staphylococcus aureus (S. aureus) being a highly studied zoontic bacterium, its enteropathogenicity remains elusive. Herein, our findings demonstrated that S. aureus infection led to the accumulation of lipid droplets (LDs) in intestinal epithelial cells, accompanied by marked elevation inflammatory response that ultimately decreases intracellular bacterial load. The aforestated phenomenon may be partly attributed to the up-regulation of hypoxia-inducible lipid droplet-associated protein (HILPDA) and the concomitant down-regulation of cystathionine β-synthase (CBS) protein. Moreover, S. aureus infection up-regulated the expression of HILPDA, thereby promoting LDs accumulation, and down-regulated that of CBS, consequently inhibiting microsomal triglyceride transfer protein (MTTP) expression. This process may suppress the transport of LDs to the extracellular environment, further contributing to the formation of intracellular LDs. In summary, the results of this study provide significant insights into the intricate mechanisms through which the host organism combats pathogens and maintains the balance of sulfur and lipid metabolism. These findings not only enhance our understanding of the host's defense mechanisms but also offer promising avenues for the development of novel strategies to combat intestinal infectious diseases.

Gut Microbiota and Sinusoidal Vasoregulation in MASLD: A Portal Perspective

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a common condition with heterogeneous outcomes difficult to predict at the individual level. Feared complications of advanced MASLD are linked to clinically significant portal hypertension and are initiated by functional and mechanical changes in the unique sinusoidal capillary network of the liver. Early sinusoidal vasoregulatory changes in MASLD lead to increased intrahepatic vascular resistance and represent the beginning of portal hypertension. In addition, the composition and function of gut microbiota in MASLD are distinctly different from the healthy state, and multiple lines of evidence demonstrate the association of dysbiosis with these vasoregulatory changes. The gut microbiota is involved in the biotransformation of nutrients, production of de novo metabolites, release of microbial structural components, and impairment of the intestinal barrier with impact on innate immune responses, metabolism, inflammation, fibrosis, and vasoregulation in the liver and beyond. The gut-liver axis is a conceptual framework in which portal circulation is the primary connection between gut microbiota and the liver. Accordingly, biochemical and hemodynamic attributes of portal circulation may hold the key to better understanding and predicting disease progression in MASLD. However, many specific details remain hidden due to limited access to the portal circulation, indicating a major unmet need for the development of innovative diagnostic tools to analyze portal metabolites and explore their effect on health and disease. We also need to safely and reliably monitor portal hemodynamics with the goal of providing preventive and curative interventions in all stages of MASLD. Here, we review recent advances that link portal metabolomics to altered sinusoidal vasoregulation and may allow for new insights into the development of portal hypertension in MASLD.

Identification of hub genes significantly linked to tuberous sclerosis related-epilepsy and lipid metabolism via bioinformatics analysis

Background

Tuberous sclerosis complex (TSC) is one of the most common genetic causes of epilepsy. Identifying differentially expressed lipid metabolism related genes (DELMRGs) is crucial for guiding treatment decisions.

Methods

We acquired tuberous sclerosis related epilepsy (TSE) datasets, GSE16969 and GSE62019. Differential expression analysis identified 1,421 differentially expressed genes (DEGs). Intersecting these with lipid metabolism related genes (LMRGs) yielded 103 DELMRGs. DELMRGs underwent enrichment analyses, biomarker selection, disease classification modeling, immune infiltration analysis, weighted gene co-expression network analysis (WGCNA) and AUCell analysis.

Results

In TSE datasets, 103 DELMRGs were identified. Four diagnostic biomarkers (ALOX12B, CBS, CPT1C, and DAGLB) showed high accuracy for epilepsy diagnosis, with an AUC value of 0.9592. Significant differences (p < 0.05) in Plasma cells, T cells regulatory (Tregs), and Macrophages M2 were observed between diagnostic groups. Microglia cells were highly correlated with lipid metabolism functions.

Conclusions

Our research unveiled potential DELMRGs (ALOX12B, CBS, CPT1C and DAGLB) in TSE, which may provide new ideas for studying the psathogenesis of epilepsy.

Nitrous Oxide Abuse: Clinical Outcomes, Pharmacology, Pharmacokinetics, Toxicity and Impact on Metabolism

The recreational use of nitrous oxide (N2O), also called laughing gas, has increased significantly in recent years. In 2022, the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) recognized it as one of the most prevalent psychoactive substances used in Europe. Chronic nitrous oxide (N2O) exposure can lead to various clinical manifestations. The most frequent symptoms are neurological (sensitive or motor disorders), but there are also other manifestations like psychiatric manifestations or cardiovascular disorders (thrombosis events). N2O also affects various neurotransmitter systems, leading to its anesthetic, analgesic, anxiolytic and antidepressant properties. N2O is very challenging to measure in biological matrices. Thus, in cases of N2O intoxication, indirect biomarkers such as vitamin B12, plasma homocysteine and plasma MMA should be explored for diagnosis and assessment. Others markers, like oxidative stress markers, could be promising but need to be further investigated.