Co-exposure to parabens, bisphenol A, and triclosan and the associations with dyslipidemia in Chinese older adults: the mediation effect of oxidative stress.

Dyslipidemia is a prevalent metabolic disorder in older adults and has negative effects on cardiovascular health. However, the combined effect of paraben, bisphenol A (BPA), and triclosan (TCS) exposure on dyslipidemia and the underlying mechanisms remain unclear. This cross-sectional study recruited 486 individuals ≥60 years in Shenzhen, China. Morning spot urine samples were collected and analyzed for four parabens, BPA, TCS, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a typical biomarker for oxidative stress, using mass spectrometry. Blood samples were tested for lipid levels using an automated biochemical analyzer. Quantile-based g-computation (QGC) was used to assess the combined effects of exposures on dyslipidemia. Mediation analysis was applied to investigate the mediating role of 8-OHdG between exposure and dyslipidemia. QGC showed that co-exposure to parabens, BPA, and TCS was positively linked with hypercholesterolemia (OR: 1.17, 95%CI: 1.10-1.24, P<0.001) and hyper-LDL-cholesterolemia (OR: 1.35, 95%CI: 1.05-1.75, P=0.019). Methylparaben (MeP), n-propyl paraben (PrP), and butylparaben (BtP) were the major contributors. 8-OHdG mediated 6.5% and 13.0% of the overall effect of the examined chemicals on hypercholesterolemia and hyper-LDL-cholesterolemia, respectively (all P<0.05). Our study indicated that co-exposure to parabens, BPA, and TCS is associated with dyslipidemia and oxidative stress partially mediate the association. Future research is needed to explore additional mechanisms underlying these relationships.

Long term exposure of saxitoxin induced cognitive deficits and YAP1 cytoplasmic retention.

While most studies assessed the acute toxicity of saxitoxin (STX), fewer studies focus on the long-term degenerative effects of STX on the central nervous system. We investigated the cognitive impairment and hippocampal damages of 6 months' exposure of low-dose STX to C57BL/6NJ mice with behavioral tests, H&E staining, and Western blots, and the possible mechanism (Ppp1C, YAP1, tau-phosphorylation) underlies the pathological changes. Furthermore, we discussed the specific localization of YAP1 in N2a cells induced by STX and the effect of inactivated Ppp1C on its downstream protein YAP1 in the Hippo signal pathway. We found STX intoxicated mice showed declined cognitive performance in both NOR test and MWM test, degenerations in the CA1 area of hippocampi. STX induced up-regulation expression of Ppp1C and YAP1 in hippocampus and N2a cells. Meanwhile, STX treatment induced cell apoptosis and Tau protein hyperphosphorylation. In addition, STX treatment promoted YAP1 cytoplasmic retention that indicates the activation of Hippo pathway, while depletion of Ppp1C inactivate YAP1 during the treatment of STX. Our results highlight the role of Ppp1C and YAP1 cytoplasmic retention in chronic low-dose STX intoxication.

Association between human herpesvirus 6 (HHV-6) and cognitive function in the elderly population in Shenzhen, China.

AIM: Human herpesvirus 6 (HHV-6) is neurophilic, and its relationship with Alzheimer's disease (AD) remains controversial. This study aimed to examine the relationships between HHV-6 and cognitive abilities in elderly people aged 60 years or above from communities in Shenzhen. METHODS: We recruited participants from 10 community health service centers in Shenzhen. Participants were divided into case and control groups according to Mini-Mental State Examination (MMSE) scale standards and were included in this study with 1:1 matching based on sex and age (± 3 years). The HHV-6 gene was detected by real-time fluorescent quantitative PCR, and the HHV-6 copy number was quantified. RESULTS: A total of 580 participants (cases, n = 290; controls, n = 290), matched for gender and age was included in this study. A positive HHV-6 test was not associated with a significant difference in global cognitive performance (ORadjusted = 1.651, 95% CI = 0.671-4.062). After adjusting for gender, age, education, Pittsburgh Sleep Quality Index (PSQI) score, homocysteine (Hcy) and glycosylated hemoglobin (HbA1c), the results of multiple linear regression showed that there was a statistically negative correlation between HHV-6 copy number and orientation (ßadjusted = -0.974, p = 0.013), attention and calculation (ßadjusted = -1.840, p < 0.001), and language (ßadjusted = -2.267, p < 0.001). The restricted cubic spline (RCS) model results showed that there was a nonlinear dose-response relationship between HHV-6 log10-transformed copies and orientation (poverall = 0.003, pnonliner = 0.045), attention and calculation (poverall < 0.001, pnonliner < 0.001), and language (poverall < 0.001, pnonliner = 0.016). CONCLUSIONS: HHV-6 infection significantly associated with orientation, attention and calculation, and language in elderly individuals.

A novel virtual screening procedure identifies Pralatrexate as inhibitor of SARS-CoV-2 RdRp and it reduces viral replication in vitro.

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus poses serious threats to the global public health and leads to worldwide crisis. No effective drug or vaccine is readily available. The viral RNA-dependent RNA polymerase (RdRp) is a promising therapeutic target. A hybrid drug screening procedure was proposed and applied to identify potential drug candidates targeting RdRp from 1906 approved drugs. Among the four selected market available drug candidates, Pralatrexate and Azithromycin were confirmed to effectively inhibit SARS-CoV-2 replication in vitro with EC50 values of 0.008µM and 9.453 µM, respectively. For the first time, our study discovered that Pralatrexate is able to potently inhibit SARS-CoV-2 replication with a stronger inhibitory activity than Remdesivir within the same experimental conditions. The paper demonstrates the feasibility of fast and accurate anti-viral drug screening for inhibitors of SARS-CoV-2 and provides potential therapeutic agents against COVID-19.

All-yarn triboelectric nanogenerator and supercapacitor based self-charging power cloth for wearable applications.

Despite rapid developments, multifunctional wearable electronics are still not significant in practical applications as compared to portable and stretchable power devices. In this paper, we present the flexible and easy large-scale production of single-electrode mode triboelectric nanogenerator (TENG) and supercapacitor yarn-based self-charging power fabric, for simultaneously converting and storing biomechanical energy. Fabricated using traditional knitting technologies, the self-charging power fabric can adapt to complex mechanical deformations owing to its high flexibility and stretchability. Additionally, the output characteristics of the TENG fabric were systematically investigated with the purpose of energy generation. The TENG fabric can generate a maximum peak power density of ∼90 mW·m-2using nylon as the contact material, with an operating frequency of 4 Hz. The as-prepared yarn-based supercapacitor exhibited high capacitance, good cycling stability, and flexibility, making it an appropriate wearable energy-storage device. Moreover, the proposed design uses energy harvested from biomechanical motions to sustainably power portable electronic devices. The results of this study indicate that the proposed design is a promising sustainable power source for wearable electronic devices.

Trichloroethylene-induced downregulation of miR-199b-5p contributes to SET-mediated apoptosis in hepatocytes.

Trichloroethylene (TCE) is a ubiquitous toxicant widespread in our environment. Exposure to TCE can cause severe liver damage. In previous studies, we detected an abnormal elevation of SET (a protein encoded by the SETgene in humans) which was observed in human HL-7702 cells (L-02 hepatocytes) under the treatment of TCE. Moreover, further study indicated that SET acts as an important mediator in TCE-induced hepatocyte apoptosis. The major functions of SET have been elucidated, while the regulatory mechanism responsible for modulation of SET remains unclear. In this study, four major microRNA-related databases were used to screen and identify 6 candidate microRNAs involved in the regulation of SET. Subsequent verification indicated that miR-21 and miR-199b-5p were decreased in TCE-treated L-02 cells, suggesting that miR-21 and miR-199b-5p (miR199b for short) miR199b potentially regulate SET expression. Additionally, the dual-luciferase system revealed that only miR199b could directly bind to untranslated region (3'-UTR) of the SETgene. Modulation of SET by miR199b was verified through overexpression and knockdown of miR199b in L-02 cells. Assessment of apoptosis indicated that elevated miR199b attenuated TCE-induced apoptosis, while reduced miR199b enhanced it. In summary, this study suggests that in cultured hepatocytes, TCE-induced suppression of miR199b drives SET induction, which further mediates the response to TCE.

Heat-Induced Epithelial Barrier Dysfunction Occurs via C-Src Kinase and P120ctn Expression Regulation in the Lungs.

BACKGROUND/AIMS: Thermal injury causes pulmonary edema and can lead to death. Intercellular junctions are composed of adhesive (p120ctn, E-cadherin, α-catenin and ß-catenin) and compact (occludin and ZO-1) junctions. Heat deteriorates intercellular junctions and increases cell gaps to ultimately induce pulmonary edema, but the underlying mechanism remains elusive. METHODS: Mouse lung epithelial (MLE-12) cells pre-treated with the c-Src inhibitor PP2, p120ctn catenin (p120ctn) small interfering RNA and p120ctn catenin (p120ctn) complementary DNA were subjected to heat treatment. Western blotting and real-time polymerase chain reaction assays were used to evaluate junction protein expression changes after heat treatment, and co-immunoprecipitation was used to test the binding state of junction proteins. In addition, hematoxylin and eosin staining and immunohistochemistry were used to evaluate changes in junction protein expression and lung injury in a Wistar rat model of thermal inhalation injury. RESULTS: Heat increased cell permeability; induced ZO-1, occludin, α-catenin and ß-catenin degradation; and decreased E-cadherin distribution in cell membranes. Heat also activated c-Src and decreased both p120ctn expression levels and occludin and ZO-1 association. c-Src inhibitor (PP2) treatment and p120ctn overexpression reversed these effects and attenuated lung injury in vivo. CONCLUSION: Heat induces junction protein degradation and dissociation to increase membrane permeability and cause lung edema via c-Src kinase activation and p120ctn expression downregulation.

Proteomic alterations of brain subcellular organelles caused by low-dose copper exposure: implication for Alzheimer's disease.

Excessive copper intake can lead to neurotoxicity, but there is a lack of comprehensive understanding on the potential impact of copper exposure especially at a low-dose on brain. We used 3xTg-AD mice to explore the potential neurotoxicity of chronic, low-dose copper treatment (0.13 ppm copper chloride in drinking water) on behavior and the brain hippocampal mitochondrial and nuclear proteome. Low-dose copper increased the spatial memory impairment of these animals, increased accumulation of intracellular amyloid 1-42 (Aß1-42), decreased ATP content, increased the positive staining of 8-hydroxyguanosine (8-OHdG), a marker of DNA oxidative damage, and caused apoptosis and a decrease in synaptic proteins. Mitochondrial proteomic analysis by two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) revealed modulation of 24 hippocampal mitochondrial proteins (14 increased and 10 decreased) in copper-treated vs. untreated 3xTg-AD mice. Nuclear proteomic analysis revealed 43 modulated hippocampal nuclear proteins (25 increased and 18 decreased) in copper-treated 3xTg-AD vs. untreated mice. Classification of modulated mitochondrial and nuclear proteins included functional categories such as energy metabolism, synaptic-related proteins, DNA damage and apoptosis-related proteins, and oxidative stress-related proteins. Among these differentially expressed mitochondrial and nuclear proteins, nine proteins were abnormally expressed in both hippocampus mitochondria and nuclei, including electron transport chain-related proteins NADH dehydrogenase 1 alpha subcomplex subunit 10 (NDUAA), cytochrome b-c1 complex subunit Rieske (UCRI), cytochrome c oxidase subunit 5B (COX5B), and ATP synthase subunit d (ATP5H), glycolytic-related pyruvate kinase PKM (KPYM) and pyruvate dehydrogenase E1 component subunit alpha (ODPA). Furthermore, we found coenzyme Q10 (CoQ10), an endogenous mitochondrial protective factor/antioxidant, modulated the expression of 12 differentially expressed hippocampal proteins (4 increased and 8 decreased), which could be classified in functional categories such as glycolysis and synaptic-related proteins, oxidative stress-related proteins, implying that CoQ10 improved synaptic function, suppress oxidative stress, and regulate glycolysis. For the proteomics study, we validated the expression of several proteins related to synapses, DNA and apoptosis. The data confirmed that synapsin-2, a synaptic-related protein, was significantly decreased in both mitochondria and nuclei of copper-exposed 3xTg-AD mice. In mitochondria, dynamin-1 (DYN1), an apoptosis-related proteins, was significantly decreased. In the cellular nuclei, paraspeckle protein 1 (PSPC1) and purin-rich element-binding protein alpha (Purα), two DNA damage-related proteins, were significantly decreased and increased, respectively. We conclude that low-dose copper exposure exacerbates the spatial memory impairment of 3xTg-AD mice and perturbs multiple biological/pathogenic processes by dysregulating the mitochondrial and nuclear proteome. Exposure to copper might therefore contribute to the evolution of AD.

Repression of Biotin-Related Proteins by Benzo[a]Pyrene-Induced Epigenetic Modifications in Human Bronchial Epithelial Cells.

Benzo[a]pyrene (B[a]P) exposure has been associated with the alteration in epigenetic marks that are involved in cancer development. Biotinidase (BTD) and holocarboxylase synthetase (HCS) are 2 major enzymes involved in maintaining the homeostasis of biotinylation, and the deregulation of this pathway has been associated with a number of cancers. However, the link between B[a]P exposure and the dysregulation of BTD/HCS in B[a]P-associated tumorigenesis is unknown. Here we showed that the expression of both BTD and HCS was significantly decreased upon B[a]P treatment in human bronchial epithelial (16HBE) cells. Benzo[a]pyrene exposure led to the global loss of DNA methylation by immunofluorescence, which coincided with the reduction in acetylation levels on histones H3 and H4 in 16HBE cells. Consistent with decreased histone acetylation, histone deacetylases (HDACs) HDAC2 and HDAC3 were significantly upregulated in a dosage-dependent manner. When DNA methylation or HDAC activity was inhibited, we found that the reduction in BTD and HCS was separately regulated through distinct epigenetic mechanisms. Together, our results suggested the potential link between B[a]P toxicity and deregulation of biotin homeostasis pathway in B[a]P-associated cancer development.

Phosphoproteomic analyses of L-02 liver cells exposed to trichloroethylene.

Trichloroethylene (TCE) is an environmental and occupational toxicant that has been shown to cause serious hepatotoxicity. However, the mechanisms underlying the hepatotoxicity of TCE remain unclear. Previously, we identified several apoptosis-related proteins in TCE-induced hepatic cytotoxicity. This study is aimed to analyze the changes in phosphoproteins in L-02 liver cells exposed to TCE using iTRAQ labeling, IMAC enrichment and LC-MS/MS. We identified 1878 phosphorylation sites in 107 proteins and found that 20 sites in 16 phosphoproteins were differentially phosphorylated in L-02 cells after TCE treatment. Among these phosphoproteins, 20% were protein localization and formation processes-related proteins, 38% were metabolism-related proteins and 42% were cellular process-related proteins, including transcriptional regulation and biogenesis. Moreover, two phosphoproteins, 4E-BP1 (37T) and MCM2 (139S), were validated as TCE-induced alteration of phosphorylation at specific sites by Western-blot analysis. Taken together, our study demonstrated that TCE exposure changed the levels of multiple phosphoproteins in L-02 liver cells, and the functional analysis suggested that these differentially expressed phosphoproteins might be involved in TCE-induced hepatic cytotoxicity.

[Research progress in carcinogenicity of trichloroethylene and its metabolites].

Trichlorethylene (TCE) is a widely used organic solvent and an important industrial material. It's easily released into the environment through manufacture, use and disposal process, so there is a wide range of occupationally and environmentally exposed population. Based on accumulated research data, International Agency for Research on Cancer (IARC) increased the carcinogenic rating of TCE from probable human carcinogen to certain human carcinogen in 2012. This paper is a review of the carcinogenic effects of TCE and its metabolites from the aspects of epidemiological data, experimental evidence on animals as well as the mechanisms of carcinogenesis.

Analysis of trichloroethylene-induced global DNA hypomethylation in hepatic L-02 cells by liquid chromatography-electrospray ionization tandem mass spectrometry.

Trichloroethylene (TCE), a major occupational and environmental pollutant, has been recently associated with aberrant epigenetic changes in experimental animals and cultured cells. TCE is known to cause severe hepatotoxicity; however, the association between epigenetic alterations and TCE-induced hepatotoxicity are not yet well explored. DNA methylation, catalyzed by enzymes known as DNA methyltransferases (DNMT), is a major epigenetic modification that plays a critical role in regulating many cellular processes. In this study, we analyzed the TCE-induced effect on global DNA methylation and DNMT enzymatic activity in human hepatic L-02 cells. A sensitive and quantitative method combined with liquid chromatography and electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) was validated and utilized for assessing the altered DNA methylation in TCE-induced L-02 cells. Quantification was accomplished in multiple reaction monitoring (MRM) mode by monitoring a transition pair of m/z 242.1 (molecular ion)/126.3 (fragment ion) for 5-mdC and m/z 268.1/152.3 for dG. The correlation coefficient of calibration curves between 5-mdC and dG was higher than 0.9990. The intra-day and inter-day relative standard derivation values (RSD) were on the range of 0.53-7.09% and 0.40-2.83%, respectively. We found that TCE exposure was able to significantly decrease the DNA methylation and inhibit DNMT activity in L-02 cells. Our results not only reveal the association between TCE exposure and epigenetic alterations, but also provide an alternative mass spectrometry-based method for rapid and accurate assessment of chemical-induced altered DNA methylation in mammal cells.

Stable SET knockdown in breast cell carcinoma inhibits cell migration and invasion.

Breast cancer is the most malignant tumor for women, however, the mechanisms underlying this devastating disease remain unclear. SET is an endogenous inhibitor of protein phosphatase 2A (PP2A) and involved in many physiological and pathological processes. SET could promote the occurrence of tumor through inhibiting PP2A. In this study, we explore the role of SET in the migration and invasion of breast cancer cells MDA-MB-231 and ZR-75-30. The stable suppression of SET expression through lentivirus-mediated RNA interference (RNAi) was shown to inhibit the growth, migration and invasion of breast cancer cells. Knockdown of SET increases the activity and expression of PP2Ac and decrease the expression of matrix metalloproteinase 9 (MMP-9). These data demonstrate that SET may be involved in the pathogenic processes of breast cancer, indicating that SET can serve as a potential therapeutic target for the treatment of breast cancer.

Interfacial Solar Evaporation: From Fundamental Research to Applications.

In the last decade, interfacial solar steam generation (ISSG), powered by natural sunlight garnered significant attention due to its great potential for low-cost and environmentally friendly clean water production in alignment with the global decarbonization efforts. This review aims to share the knowledge and engage with a broader readership about the current progress of ISSG technology and the facing challenges to promote further advancements toward practical applications. The first part of this review assesses the current strategies for enhancing the energy efficiency of ISSG systems, including optimizing light absorption, reducing energy losses, harvesting additional energy, and lowering evaporation enthalpy. Subsequently, the current challenges faced by ISSG technologies, notably salt accumulation and bio-fouling issues in practical applications, are elucidated and contemporary methods are discussed to overcome these challenges. In the end, potential applications of ISSG, ranging from initial seawater desalination and industrial wastewater purification to power generation, sterilization, soil remediation, and innovative concept of solar sea farm, are introduced, highlighting the promising potential of ISSG technology in contributing to sustainable and environmentally conscious practices. Based on the review and in-depth understanding of these aspects, the future research focuses are proposed to address potential issues in both fundamental research and practical applications.

Compromised very-low density lipoprotein induced polyunsaturated triglyceride accumulation in N-nitrosodiethylamine-induced hepatic steatosis.

N-Nitrosodiethylamine (NDEA), a carcinogen in some foods and medications, is linked to liver damage similar to non-alcoholic fatty liver disease (NAFLD). This study explores how NDEA disrupts liver lipid metabolism. Sprague-Dawley rats were given two doses of NDEA (100 mg/kg) orally, 24 h apart. Liver response was assessed through tissue staining, blood tests, and biochemical markers, including fatty acids, lipid peroxidation, and serum very-low density lipoprotein (VLDL) levels. Additionally, lipidomic analysis of liver tissues and serum was performed. The results indicated significant hepatic steatosis (fat accumulation in the liver) following NDEA exposure. Blood analysis showed signs of inflammation and liver damage. Biochemical tests revealed decreased liver protein synthesis and specific enzyme alterations, suggesting liver cell injury but maintaining mitochondrial function. Increased fatty acid levels without a rise in lipid peroxidation were observed, indicating fat accumulation. Lipidomic analysis showed increased polyunsaturated triglycerides in the liver and decreased serum VLDL, implicating impaired VLDL transport in liver dysfunction. In conclusion, NDEA exposure disrupts liver lipid metabolism, primarily through the accumulation of polyunsaturated triglycerides and impaired fat transport. These findings provide insight into the mechanisms of NDEA-induced liver injury and its progression to hepatic steatosis.

Polyelectrolyte Hydrogel-Functionalized Photothermal Sponge Enables Simultaneously Continuous Solar Desalination and Electricity Generation Without Salt Accumulation.

Technologies that can simultaneously generate electricity and desalinate seawater are highly attractive and required to meet the increasing global demand for power and clean water. Here, a bifunctional solar evaporator that features continuous electric generation in seawater without salt accumulation is developed by rational design of polyelectrolyte hydrogel-functionalized photothermal sponge. This evaporator not only exhibits an unprecedentedly high water evaporation rate of 3.53 kg m-2 h-1along with 98.6% solar energy conversion efficiency but can also uninterruptedly deliver a voltage output of 0.972 V and a current density of 172.38 µA cm-2 in high-concentration brine over a prolonged period under one sun irradiation. Many common electronic devices can be driven by simply connecting evaporator units in series or in parallel without any other auxiliaries. Different from the previously proposed power generation mechanism, this study reveals that the water-enabled proton concentration fields in intermediate water region can also induce an additional ion electric field in free water region containing solute, to further enhance electricity output. Given the low-cost materials, simple self-regeneration design, scalable fabrication processes, and stable performance, this work offers a promising strategy for addressing the shortages of clean water and sustainable electricity.

Inhibition of autophagosome-lysosome fusion contributes to TDCIPP-induced Aß1-42 production in N2a-APPswe cells.

Alzheimer's disease is the most common form of dementia and is characterized by cognitive impairment. The disruption of autophagosome-lysosome function has been linked to the pathogenesis of Alzheimer's disease. Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphorus flame retardant that has the potential to cause neuronal damage. We found that TDCIPP significantly increased the expression of ß-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), presenilin-1 (PS1) and Aß42. Proteomic studies with TMT labeling revealed changes in the profiles of N2a-APPswe cells after exposure to TDCIPP. Proteomic and bioinformatics analyses revealed that lysosomal proteins were dysregulated in N2a-APPswe cells after treatment with TDCIPP. The LC3, P62, CTSD, and LAMP1 levels were increased after TDCIPP exposure, and dysregulated protein expression was validated by Western blotting. The exposure to TDCIPP led to the accumulation of autophagosomes, and this phenomenon was enhanced in the presence of chloroquine (CQ). Our results revealed for the first time that TDCIPP could be a potential environmental risk factor for AD development. The inhibition of autophagosome-lysosome fusion may have a significant impact on the generation of Aß1-42 in response to TDCIPP.

Analysis of the differences in physicochemical properties, volatile compounds, and microbial community structure of pit mud in different time spaces.

Pit mud (PM) is among the key factors determining the quality of Nongxiangxing baijiu, a Chinese liquor. Microorganisms present inside PM are crucial for the unique taste and flavor of this liquor. In this study, headspace solid-phase microextraction was used in combination with gas chromatography and high-throughput sequencing to determine the volatile compounds and microbial community structure of 10- and 40-year PM samples from different spaces. The basic physicochemical properties of the PM were also determined. LEfSe and RDA were used to systematically study the PM in different time spaces. The physicochemical properties and ester content of the 40-year PM were higher than those of the 10-year PM, but the spatial distribution of the two years PM samples exhibited no consistency, except in terms of pH, available phosphorus content, and ester content. In all samples, 29 phyla, 276 families, and 540 genera of bacteria, including four dominant phyla and 20 dominant genera, as well as eight phyla, 24 families, and 34 genera of archaea, including four dominant phyla and seven dominant genera, were identified. The LEfSe analysis yielded 18 differential bacteria and five differential archaea. According to the RDA, the physicochemical properties and ethyl caproate, ethyl octanoate, hexanoic acid, and octanoic acid positively correlated with the differential microorganisms of the 40-year PM, whereas negatively correlated with the differential microorganisms of the 10-year PM. Thus, we inferred that Caproiciproducens, norank_f__Caloramatoraceae, and Methanobrevibacter play a dominant and indispensable role in the PM. This study systematically unveils the differences that affect the quality of PM in different time spaces and offers a theoretical basis for improving the declining PM, promoting PM aging, maintaining cellars, and cultivating an artificial PM at a later stage.

Associations of urinary nicotine metabolites and essential metals with metabolic syndrome in older adults: The mediation effect of insulin resistance.

Exposure to tobacco smoke and essential metals is linked with metabolic syndrome (MS). However, the joint effect of them on MS in older adults and the underlying mechanisms are still unclear. This large-scale study measured the urinary concentrations of 8 nicotine metabolites and 8 essential metals in 4564 older adults from Shenzhen, China. The biomarker of insulin resistance, triglyceride-glucose index (TyG), was also calculated. Restricted cubic splines (RCS), Bayesian kernel machine regression and quantile-based g-computation were used to access the single and joint effects of urinary nicotine metabolites and essential metals on MS and insulin resistance. Mediation analysis was performed to investigate the role of TyG in these relationships. Single urinary nicotine metabolite and essential metal had non-linear relationships with MS in RCS. The overall effect of urinary nicotine metabolites and essential metals was positively associated with MS. Urinary zinc (52.2 %) and copper (20.1 %) were the major contributors to MS, whereas molybdenum had a negative association with MS. TyG mediated 64.7 % of the overall effect of urinary nicotine metabolites and essential metals on MS. Overall, the mixture of urinary nicotine metabolites and essential metals had a dose-response relationship with MS. Insulin resistance was as a crucial mediated pathway in this association.

The role of mitochondrial dysfunction in the association between trace metals and QTc prolongation in the aged population.

This study delves into the relationship between environmental metal exposure and QT interval corrected for heart rate (QTc) prolongation, a critical marker for cardiovascular risk in the elderly. Although the interplay between metal exposure and QTc prolongation is important for predicting sudden cardiac death, it remains underexplored. Our analysis of 6478 participants from the Shenzhen aging-related disorder cohort involved measuring urinary concentrations of 22 trace metals and using mitochondrial DNA copy number (mtDNA-CN) as an indicator of mitochondrial dysfunction. Utilizing Bayesian kernel machine regression, and structural equation modeling, we assessed the effects of mixed trace metals on QTc prolongation. Our findings indicated a direct association between certain metals (Sb, Cu, Zn) and a 7 % increase in QTc prolongation risk, while Li, V, and Rb were associated with a 5 % reduction in risk. Elevated levels of V, Ti, and Cr corresponded to higher mtDNA-CN. Notably, restricted cubic splines revealed a U-shaped, nonlinear relationship between mtDNA-CN and QTc prolongation. After adjusting for metal exposure, an inverse correlation was observed between mtDNA-CN and QTc prolongation, suggesting mitochondrial dysfunction as a partial mediator.