Mechanism of Learning and Memory Impairment in Rats Exposed to Arsenic and/or Fluoride Based on Microbiome and Metabolome.

Objective: Arsenic (As) and fluoride (F) are two of the most common elements contaminating groundwater resources. A growing number of studies have found that As and F can cause neurotoxicity in infants and children, leading to cognitive, learning, and memory impairments. However, early biomarkers of learning and memory impairment induced by As and/or F remain unclear. In the present study, the mechanisms by which As and/or F cause learning memory impairment are explored at the multi-omics level (microbiome and metabolome). Methods: We stablished an SD rats model exposed to arsenic and/or fluoride from intrauterine to adult period. Results: Arsenic and/fluoride exposed groups showed reduced neurobehavioral performance and lesions in the hippocampal CA1 region. 16S rRNA gene sequencing revealed that As and/or F exposure significantly altered the composition and diversity of the gut microbiome，featuring the Lachnospiraceae_NK4A136_group, Ruminococcus_1, Prevotellaceae_NK3B31_group, [Eubacterium]_xylanophilum_group. Metabolome analysis showed that As and/or F-induced learning and memory impairment may be related to tryptophan, lipoic acid, glutamate, gamma-aminobutyric acidergic (GABAergic) synapse, and arachidonic acid (AA) metabolism. The gut microbiota, metabolites, and learning memory indicators were significantly correlated. Conclusion: Learning memory impairment triggered by As and/or F exposure may be mediated by different gut microbes and their associated metabolites.

Mechanism of subchronic vinyl chloride exposure combined with a high-fat diet on hepatic steatosis.

Vinyl chloride (VC) is a common industrial organic chlorine and environmental pollutant. In recent years, the dietary structure of residents especially Chinese has gradually shifted to western dietary patterns. VC aggravates dietary fatty acid-induced hepatic steatosis, but its mechanism is still unclear. And if the risk factors for steatosis persist, more severe diseases such as fibrosis and cirrhosis will occur. Therefore, we studied the effects and mechanisms of VC (160 and 800 mg/m3 ) and its metabolite (chloroacetaldehyde, 2.25, 4.5, and 9 µM) on hepatic steatosis of high-fat diet (HFD)-fed mice and palmitic acid (PA, 100 µM) treated HepG2 cells. Liver and serum biochemical indicators and pathological staining of the liver showed that the hepatic steatosis of VC combined with HFD groups was more severe than that of single-exposure groups (HFD group, low-dose VC group, and high-dose VC group). Moreover, VC enhanced HFD-induced oxidative stress (OS) and endoplasmic reticulum stress (ERS) and further upregulated the expression of sterol regulatory element-binding protein 1 (SREBP-1) and FAS. Besides, antioxidants and ERS inhibitors reduced the steatosis of HepG2 cells induced by VC metabolites and PA. These results suggest that VC exposure can enhance the degree of hepatic steatosis in HFD-fed mice. VC combined with HFD led to OS and ERS and upregulated the expression of de novo lipogenesis-related proteins, which may be related to the occurrence of hepatic steatosis. And the increased expression of CYP2E1 induced by VC combined with HFD may be the cause of OS.

Relative Telomere Length in Peripheral Blood Cells and Hypertension Risk among Mine Workers: A Case-Control Study in Chinese Coal Miners.

Hypertension is a common chronic disease in middle-aged and elderly people and is an important risk factor for many cardiovascular diseases. Its pathogenesis remains unclear. Epidemiological studies have found that the loss of telomere length in peripheral blood cells can increase the risk of coronary heart disease, myocardial infarction, and other diseases. However, a correlation between loss of telomere length and hypertension has not been established. In this study, we aimed to explore the association between telomere length and the risk of essential hypertension (EH) in Chinese coal miners. A case-control study was performed with 215 EH patients and 222 healthy controls in a large coal mining group located in North China. Face-to-face interviews were conducted by trained staff with the necessary medical knowledge. Relative telomere length (RTL) was measured by a quantitative real-time PCR assay using DNA extracted from peripheral blood. In the control group, the age-adjusted RTL was statistically significantly lower in miners performing hard physical labour compared with nonphysical labour (P = 0.043). A significantly shorter age-adjusted RTL was found in the control group of participants who consumed alcohol regularly compared with those who do not consume alcohol (P = 0.024). Age-adjusted RTL was negatively correlated with body mass index (BMI) and alcohol consumption. Hypertension was also found to be significantly correlated with factors such as age, BMI, alcohol consumption, smoking, and tea consumption. Our results suggest that RTL is associated with hypertension in coal miners.