Nanoplastics and chrysene pollution: Potential new triggers for nonalcoholic fatty liver disease and hepatitis, insights from juvenile Siniperca chuatsi

Associations of metabolic dysfunction-related fatty liver disease and dementia risk: A prospective study based on the UK biobank

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) has garnered increasing attention for its potential link with dementia. This study aims to investigate the association between MAFLD and dementia, including its subtypes, to address existing knowledge gaps.

METHODS

A total of 415,116 participants from the UK Biobank were included, with standardized screening criteria used to determine MAFLD diagnosis. Cox regression was employed to assess the relationship between MAFLD and dementia risk. Subgroup analyzes were conducted to provide further insights into the impact of MAFLD on dementia risk, and the mediation effect of inflammation was evaluated.

RESULTS

Among the 150,509 MAFLD patients, there was a significantly elevated risk of dementia, with hazard ratios (HR) of 1. 526 (95 % CI = 1. 460-1. 596) for all-cause dementia, 1. 356 (95 % CI = 1. 266-1. 453) for Alzheimer's disease (AD), and 2. 206 (95 % CI = 2. 000-2. 434) for vascular dementia (VaD). MAFLD patients showed a significant reduction in gray matter volume in MAFLD patients (β = -0. 07, 95 % CI = -0. 17, -0. 01) and a marked increase in deep white matter lesion volume (P < 0. 001). Elevated inflammatory markers in MAFLD patients accounted for a mediation effect of 30. 8 %.

CONCLUSION

MAFLD substantially increases the risk of dementia, underscoring the importance of early intervention and prevention strategies targeting MAFLD to reduce dementia incidence.

Impact of polystyrene nanoplastics on apoptosis and inflammation in zebrafish larvae: Insights from reactive oxygen species perspective

In recent years, there has been a growing focus on the toxicity and mortality induced by nanoplastics (NPs) in aquatic organisms. However, studies investigating mechanisms underlying oxidative stress (OS), apoptosis, and inflammation induced by NPs in fish remain limited. This study observed that polystyrene NPs (PS-NPs) were accumulated into zebrafish larvae and zebrafish embryonic fibroblast (ZF4 cells), accompanied by the occurrence of pathological damage both at the cellular and tissue-organ level. Additionally, the transcriptional up-regulation of NADPH oxidases (NOXs) and subsequent excessive generation of reactive oxygen species (ROS) resulted in notable changes in the relative mRNA and protein expression levels associated with antioxidant oxidase systems in larvae. Furthermore, the study identified the impact of NPs on mitochondrial ultrastructural, resulting in mitochondrial depolarization and downregulation of mRNA expression related to the electron transport chain due to excessive ROS generation. Short-term exposure to NPs also triggered apoptosis and inflammation in zebrafish larvae, evident from significant up-regulation in mRNA expressions of proapoptotic factors and NF-κB proinflammatory signaling pathway, as well as increased transcription and protein levels of pro-inflammatory factors in larvae. Inhibition of intracellular excessive ROS effectively reduced the induction of apoptosis, NF-κB P65 nuclear migration levels, and cytokine secretion, underscoring OS as a pivotal factor throughout the process of apoptosis and inflammatory responses induced by NPs. This research significantly advances our comprehension of biological effects and underlying mechanisms of NPs in freshwater fish.

The silent threat: Nanopolystyrene and chrysene pollutants disrupt the intestinal mucosal barrier, new insights from juvenile Siniperca chuatsi

The intestinal mucosal barrier-comprising microbial, mechanical, chemical, and immunological barriers-is critical to protection against pathogens and maintenance of host health; however, it remains unclear whether it is affected by environmental contaminants. Therefore, the present study assessed whether exposure to ambient concentrations of nanopolystyrene (NP) and chrysene (CHR)-two ubiquitous environmental pollutants in the aquatic environment-affect the intestinal mucosal barrier in juvenile Siniperca chuatsi. After exposure for 21 days, S. chuatsi exhibited intestinal oxidative stress and imbalance of intestinal microbial homeostasis. NP and/or CHR exposure also disrupted the intestinal mechanical barrier, as evidenced by the altered intestinal epithelial cell morphology, disrupted structure of intercellular tight junctions, and decreased expression of tight junction proteins. Damage to the intestinal chemical barrier manifested as thinning of the mucus layer owing to the loss and damage of goblet cells. Furthermore, the intestinal immunological barrier was impaired as indicated by the loss of intestinal intraepithelial lymphocytes and increase in pro-inflammatory cytokines, chemokines, and immunoglobulins. These findings collectively suggest that the intestinal mucosal barrier was damaged. This study is, to the best of our knowledge, the first to report that exposure to NP and/or CHR at environmentally relevant concentrations disrupts the intestinal mucosal barrier in organisms and highlight the significance of nanoplastic/CHR pollution for intestinal health.