ROS/mtROS promotes TNTs formation via the PI3K/AKT/mTOR pathway to protect against mitochondrial damages in glial cells induced by engineered nanomaterials.

BACKGROUND: As the demand and application of engineered nanomaterials have increased, their potential toxicity to the central nervous system has drawn increasing attention. Tunneling nanotubes (TNTs) are novel cell-cell communication that plays a crucial role in pathology and physiology. However, the relationship between TNTs and nanomaterials neurotoxicity remains unclear. Here, three types of commonly used engineered nanomaterials, namely cobalt nanoparticles (CoNPs), titanium dioxide nanoparticles (TiO2NPs), and multi-walled carbon nanotubes (MWCNTs), were selected to address this limitation. RESULTS: After the complete characterization of the nanomaterials, the induction of TNTs formation with all of the nanomaterials was observed using high-content screening system and confocal microscopy in both primary astrocytes and U251 cells. It was further revealed that TNT formation protected against nanomaterial-induced neurotoxicity due to cell apoptosis and disrupted ATP production. We then determined the mechanism underlying the protective role of TNTs. Since oxidative stress is a common mechanism in nanotoxicity, we first observed a significant increase in total and mitochondrial reactive oxygen species (namely ROS, mtROS), causing mitochondrial damage. Moreover, pretreatment of U251 cells with either the ROS scavenger N-acetylcysteine or the mtROS scavenger mitoquinone attenuated nanomaterial-induced neurotoxicity and TNTs generation, suggesting a central role of ROS in nanomaterials-induced TNTs formation. Furthermore, a vigorous downstream pathway of ROS, the PI3K/AKT/mTOR pathway, was found to be actively involved in nanomaterials-promoted TNTs development, which was abolished by LY294002, Perifosine and Rapamycin, inhibitors of PI3K, AKT, and mTOR, respectively. Finally, western blot analysis demonstrated that ROS and mtROS scavengers suppressed the PI3K/AKT/mTOR pathway, which abrogated TNTs formation. CONCLUSION: Despite their biophysical properties, various types of nanomaterials promote TNTs formation and mitochondrial transfer, preventing cell apoptosis and disrupting ATP production induced by nanomaterials. ROS/mtROS and the activation of the downstream PI3K/AKT/mTOR pathway are common mechanisms to regulate TNTs formation and mitochondrial transfer. Our study reveals that engineered nanomaterials share the same molecular mechanism of TNTs formation and intercellular mitochondrial transfer, and the proposed adverse outcome pathway contributes to a better understanding of the intercellular protection mechanism against nanomaterials-induced neurotoxicity.

Single-cell RNA-sequencing of cellular heterogeneity and pathogenic mechanisms in paraquat-induced Parkinson's disease with depression.

Parkinson's disease (PD) is among the most prevalent neurodegenerative diseases, and approximately one third of patients with PD are estimated to have depression. Paraquat (PQ) exposure is an important environmental risk factor for PD. In this study, we established a mouse model of PQ-induced PD with depression to comprehensively investigate cellular heterogeneity and the mechanisms underlying the progression of depression in the context of PD. We utilized single-cell RNA-seq (scRNA-seq) to acquire the transcriptomic atlas of individual cells from model mice and characterize the gene expression profiles in each differentially expressed cell type. We identified a specific glutamatergic neuron cluster responsible for the development of heterogeneous depression-associated changes and established a comprehensive gene expression atlas. Furthermore, functional enrichment and cell trajectory analyses revealed that the mechanisms underlying the progression of PD with depression were associated with specific glutamatergic neurons. Together, our findings provide a valuable resource for deciphering the cellular heterogeneity of PD with depression. The suggested connection between intrinsic transcriptional states of neurons and the progression of depression can provide insight into potential biomarkers and specific targets for anti-depression treatment in patients with PD. SYNOPSIS: Our results obtained using model mice confirm the core effects of PQ exposure on glutamatergic neurons and their potential role in the development of PD with depression.

Expression profiling of N6-methyladenosine-modified mRNA in PC12 cells in response to unconjugated bilirubin.

BACKGROUND: Abnormal methylation of N6-methyladenosine (m6A) is reportedly associated with central nervous system disorders. However, the role of m6A mRNA methylation in unconjugated bilirubin (UCB) neurotoxicity requires further research. METHODS: Rat pheochromocytoma PC12 cells treated with UCB were used as in vitro models. After the PC12 cells were treated with UCB (0, 12, 18, and 24 µM) for 24 h, the total RNA m6A levels were measured using an m6A RNA methylation quantification kit. The expression of m6A demethylases and methyltransferases was detected through western blotting. We determined the m6A mRNA methylation profile in PC12 cells exposed to UCB (0 and 18 µM) for 24 h using methylated RNA immunoprecipitation sequencing (MeRIP-seq). RESULTS: Compared with the control group, UCB (18 and 24 µM) treatment decreased the expression of the m6A demethylase ALKBH5 and increased the expression of the methyltransferases METTL3 and METTL14, which resulted in an increase in the total m6A levels in PC12 cells. Furthermore, 1533 m6A peaks were significantly elevated and 1331 peaks were reduced in the UCB (18 µM)-treated groups compared with those in the control group. Genes with differential m6A peaks were mainly enriched in protein processing in the endoplasmic reticulum, ubiquitin-mediated proteolysis, cell cycle, and endocytosis. Through combined analysis of the MeRIP-seq and RNA sequencing data, 129 genes with differentially methylated m6A peaks and differentially expressed mRNA levels were identified. CONCLUSION: Our study suggests that the modulation of m6A methylation modifications plays a significant role in UCB neurotoxicity.

Hyperuricemia and coronary heart disease: The mediating role of blood pressure and thrombospondin 3.

BACKGROUND & AIMS: Although hyperuricemia is a known risk factor for coronary heart disease (CHD), little is known about the role of blood pressure in mediating this association. The purpose of this study is to investigate the role of blood pressure-related indicators and Thrombospondin 3 (THBS3) in the association between hyperuricemia and CHD. METHODS AND RESULTS: Our observational epidemiology study included 593 CHD cases and 760 controls from a residential stable sample. We also chose 43 new CHD patients and 43 controls to test the expression levels of THBS3 using ELISA kits. We used logistic regression models and mediating effect analysis to investigate the relationships between hyperuricemia and CHD, as well as the mediating role of blood pressure-related indicators and THBS3. In the general population (OR: 2.001 [95% CI: 1.528-2.622]), male population (OR: 1.591 [95% CI: 1.119-2.262]), and female population (OR: 2.813 [95% CI: 1.836-4.310]), hyperuricemia is an independent risk factor for CHD. In general, average systolic blood pressure (SBP) and average pulse pressure difference (PPD) mediated 3.35% and 4.59%, respectively, of the association between hyperuricemia and CHD, and 6.60% and 6.60% in women. However, in the male population, we have not yet found that blood pressure-related indicators had a significant mediating effect. Meanwhile, we found that THBS3 mediated 19.23% of the association between hyperuricemia and CHD. CONCLUSIONS: Average SBP, PPD, and THBS3 all play a role in the association of hyperuricemia and CHD. In the female population, similar mediating results in blood pressure-related indicators were observed.

Exploring the association between circRNA expression and pediatric obesity based on a case-control study and related bioinformatics analysis.

OBJECTIVE: Our present study utilized case-control research to explore the relationship between specific circRNAs and pediatric obesity through a literature review and bioinformatics and to predict their possible biological functions, providing ideas for epigenetic mechanism studies of pediatric obesity. METHODS: CircRNAs related to pediatric obesity were preliminarily screened by a literature review and qRT-PCR. CircRNA expression in children with obesity (n = 75) and control individuals (n = 75) was confirmed with qRT-PCR in a case-control study. This was followed by bioinformatics analyses, such as GO analysis, KEGG pathway analysis, and ceRNA network construction. Multivariate logistic regression was utilized to analyze the effects of circRNAs on obesity. A receiver operating characteristic (ROC) curve was also drawn to explore the clinical application value of circRNAs in pediatric obesity. RESULTS: Has_circ_0046367 and hsa_circ_0000284 were separately validated to be statistically downregulated and upregulated, respectively, in the peripheral blood mononuclear cells of children with obesity and revealed as independent indicators of increased CHD risk [hsa_circ_0046367 (OR = 0.681, 95% CI: 0.480 ~ 0.967) and hsa_circ_0000284 (OR = 1.218, 95% CI: 1.041 ~ 1.424)]. The area under the ROC curve in the combined analysis of hsa_circ_0046367 and hsa_circ_0000284 was 0.706 (95% CI: 0.623 ~ 0.789). Enrichment analyses revealed that these circRNAs were actively involved in neural plasticity mechanisms, cell secretion and signal regulation. CONCLUSION: The present research revealed that low expression of hsa_circ_0046367 and high expression of hsa_circ_0000284 are risk factors for pediatric obesity and that neural plasticity mechanisms are closely related to obesity.

Microglia-derived exosomal circZNRF1 alleviates paraquat-induced neuronal cell damage via miR-17-5p.

Paraquat (PQ) is an environmental poison that causes clinical symptoms similar to those of Parkinson's disease (PD) in vitro and in rodents. It can lead to the activation of microglia and apoptosis of dopaminergic neurons. However, the exact role and mechanism of microglial activation in PQ-induced neuronal degeneration remain unknown. Here, we isolated the microglia-derived exosomes exposed with 0 and 40 µM PQ, which were subsequently co-incubated with PQ-exposed neuronal cells to simulate intercellular communication. First, we found that exosomes released from microglia caused a change in neuronal cell vitality and reversed PQ-induced neuronal apoptosis. RNA sequencing data showed that these activated microglia-derived exosomes carried large amounts of circZNRF1. Moreover, a bioinformatics method was used to study the underlying mechanism of circZNRF1 in regulating PD, and miR-17-5p was predicted to be its target. Second, an increased Bcl2/Bax ratio could play an anti-apoptotic role. Bcl2 was predicted to be a downstream target of miR-17-5p. Our results showed that circZNRF1 plays an anti-apoptotic role by absorbing miR-17-5p and regulating the binding of Bcl2 after exosomes are internalized by dopaminergic neurons. In conclusion, we demonstrated a new intercellular communication mechanism between microglia and neurons, in which circZNRF1 plays a key role in protecting against PQ-induced neuronal apoptosis through miR-17-5p to regulate the biological process of PD. These findings may offer a novel approach to preventing and treating PD.

Association between polyfluoroalkyl substances exposure and sex steroids in adolescents: The mediating role of serum albumin.

BACKGROUND: Polyfluoroalkyl substances (PFASs) are an emerging class of contaminants with endocrine disrupting hazards. The impact of PFASs exposure on sex steroids remain inconclusive. METHODS: This study used data from the 2013-2016 National Health and Nutrition Examination Survey (NHANES), including 525 adolescents aged 12-19. We explored the association between serum PFASs and sex steroids using multiple linear regression, weighted quantified sum (WQS) regression, and Bayesian kernel machine regression (BKMR). Mediation analyses were performed to assess whether serum albumin mediates the effects of PFASs on sex steroids. RESULTS: Single exposure to perfluorohexane sulfonic acid (PFHxS) or n-perfluorooctanoic acid (n-PFOA) was found to be inversely associated with sex hormone binding protein (SHBG) after adjustment for confounders. Results from both the WQS and BKMR models showed that mixed exposure to the five PFASs was negatively associated with SHBG and testosterone (TT) in all adolescents, while only in the WQS model, the mixed exposure to PFASs was negatively correlated with E2 and FAI in boys and negatively correlated with TT and SHBG in girls. Serum albumin was found to possibly mediate 9.7 % of the association between mixed PFAS exposure and TT, and 9.7 % of the association between mixed PFAS exposure and SHBG. CONCLUSION: Our study demonstrates a negative association between mixed exposure to PFASs and adolescent TT and SHBG levels, and suggests that albumin may merit further study as a potential target for PFAS harm reduction.

The interplay between lncRNA NR_030777 and SF3B3 in neuronal damage caused by paraquat.

Paraquat (PQ) has been widely acknowledged as an environmental risk factor for Parkinson's disease (PD). However, the interaction between splicing factor and long non-coding RNA (lncRNA) in the process of PQ-induced PD has rarely been studied. Based on previous research, this study focused on splicing factor 3 subunit 3 (SF3B3) and lncRNA NR_030777. After changing the target gene expression level by lentiviral transfection technology, the related gene expression was detected by western blot and qRT-PCR. The expression of SF3B3 protein was reduced in Neuro-2a cells after PQ exposure, and the reactive oxygen species (ROS) scavenger N-acetylcysteine prevented this decline. Knockdown of SF3B3 reduced the PQ-triggered NR_030777 expression increase, and overexpression of NR_030777 reduced the transcriptional and translational level of Sf3b3. Then, knockdown of SF3B3 exacerbated the PQ-induced decrease in cell viability and aggravated the reduction of tyrosine hydroxylase (TH) protein expression. Overexpressing SF3B3 reversed the reduction of TH expression caused by PQ. Moreover, after intervention with the autophagy inhibitor Bafilomycin A1, LC3B-II protein expression was further increased in Neuro-2a cells with the knockdown of SF3B3, indicating that autophagy was enhanced. In conclusion, PQ modulated the interplay between NR_030777 and SF3B3 through ROS production, thereby impairing autophagic flux and causing neuronal damage.

Paraquat-induced oxidative stress regulates N6-methyladenosine (m6A) modification of long noncoding RNAs in Neuro-2a cells.

Paraquat (PQ) is a ubiquitously applied herbicide. Long-term PQ exposure with low dose has been reported to induce abnormal expression of long non-coding RNAs (lncRNAs) in brain nerve cells, which could further lead to Parkinson's disease (PD). N6-methyladenosine (m6A) modification has recently been identified as having an important role in regulating the function of lncRNAs. However, how m6A modification regulates lncRNAs following PQ exposure remains largely unknown. Herein, this study reported m6A modification of lncRNAs in mouse neuroblastoma cells (Neuro-2a) following PQ induced reactive oxide species (ROS). M6A sequencing was performed to explore the m6A modificated pattern of lncRNAs in Neuro-2a cells which were treated with 200 µM PQ for 3 h. It was found that PQ hypermethylated total RNA and changed the expression of m6A methyltransferase and demethylase proteins, which leading to the alteration of m6A modification of lncRNAs. Furthermore, the functional analysis further revealed that N-acetyl-L-cysteine (NAC)，a ROS scavengers, partly reversed PQ-induced distinct m6A modificated pattern of lncRNAs. In addition, tow specific m6A modified lncRNAs were identified: cell division cycle 5-like (lncRNA CDC5L) and signal transducer and activator of transcription 3 (lncRNA STAT3), which could influence downstream autophagy related biological function. In summary, this work could potentially contribute to the new insight of lncRNAs m6A modification mechanism in the field of environmental toxicology.

NOX2 activation contributes to cobalt nanoparticles-induced inflammatory responses and Tau phosphorylation in mice and microglia.

Despite the wide application of cobalt nanoparticles (CoNPs), its neurotoxicity and the underlying mechanisms are not fully understood. In this study, CoNPs-induced toxic effect was examined in both C57BL/6J mice and microglial BV2 cells. CoNPs-induced brain weight loss and the reduction of Nissl bodies, assuring neural damage. Moreover, both total unphosphorylated Tau and phosphorylated Tau (pTau; T231 and S262) expressions in the hippocampus and cortex were upregulated, unveiling Tau phosphorylation. Besides, the increase in inflammation-related proteins NLRP3 and IL-1ß were found in mice brain. Corroborating that, microglial marker Iba-1 expression was also increased, suggesting microglia-involved inflammation. Among the NADPH oxidase (NOX) family proteins tested, only NOX2 was activated by CoNPs in hippocampus. Therefore, BV2 cells were employed to further investigate the role of NOX2. In BV2 cells, NOX2 expression was upregulated, corresponding to the production of ROS. Moreover, similar induction in Tau phosphorylation and inflammation-related protein expressions were observed in CoNPs-exposed BV2 cells. Treatment of apocynin, a NOX2 inhibitor, reduced ROS generation and reversed Tau phosphorylation and inflammation caused by CoNPs. Thus, CoNPs induced ROS production, Tau phosphorylation and inflammation specially via NOX2 activation.

The negative role of histone acetylation in cobalt chloride-induced neurodegenerative damages in SHSY5Y cells.

Cobalt has been known for its neurotoxicity in numerous studies. However, the molecular mechanism underlying cobalt-induced neurotoxicity remains largely unknown. In this study, two neuroblastoma (SHSY5Y and N2a) cell lines and a phaeochromocytoma (PC12) line were used as in vitro models. Cells were treated for 24 h with 50, 100, 200, 300, 400 µM cobalt chloride (CoCl2) or cultured with 300 µM CoCl2 for 4, 8, 12 and 24 h to investigate the effects of histone acetylation on CoCl2-induced neurodegenerative damages. Our findings demonstrate that CoCl2 suppresses the acetylation of histone H3 and H4 in a time-dependent and dosage-dependent manner. Furthermore, CoCl2 selectively decreases the expression and activity of histone acetyltransferase (HAT) but has no effects on histone deacetylase (HDAC) in SHSY5Y cells. More importantly, we show that 100 ng/mL HDAC inhibitor trichostatin (TSA) pre-treatment partly attenuates 300 µM CoCl2-induced neurodegenerative damages in SHSY5Y cells. Mechanistic analyses show that CoCl2-induced neurodegenerative damages are associated with the dysfunction of APP, BACE1, PSEN1, NEP and HIF-1α genes, whose expression are partly mediated by histone modification. In summary, we demonstrate that histone acetylation is involved in CoCl2-induced neurodegenerative damages. Our study indicates an important connection between histone modification and the pathological process of neurodegenerative damages and provides a mechanism for cobalt-mediated epigenetic regulation.

Associations between meteorological variation and rupture of intracranial aneurysm in Fujian, China: A 5-year multicenter study.

OBJECTIVE: By exploring the exposure-response relationships between meteorological factors and rupture of intracranial aneurysm (IA) to reveal the influence of meteorological variation on IA rupture under the specific climate in Fujian, China. METHOD: 7515 cases of IA rupture from several municipal medical institutions in Fujian Province as well as local meteorological data during the same period were collected from 2013 to 2017. Poisson regression and Spearman correlation analysis were applied to explore the distribution characteristics of IA rupture and how it is associated with meteorological parameters. Poisson generalized additive model was established to further analyze the exposure-response relationships between meteorological factors and IA rupture, and its hysteresis effects. RESULT: The IA rupture exhibited a negative correlation with temperature (rs = -0.323, 95% CI: -0.539 ~ -0.068) and a positive correlation with atmospheric pressure (rs = 0.397, 95% CI: 0.152-0.597) or pressure difference (rs = 0.296, 95% CI: 0.038-0.517), 21.05 â„ƒ and 1000.14 hPa were the risk thresholds for the onset ascribed to variation in temperature and atmospheric pressure, respectively. Temperature and atmospheric pressure also exerted hysteresis effects on IA rupture. Cold will increase the rupture risk in the subsequent 1-3 days, and high pressure will raise the morbidity in the next 1-2 days. Besides, drastic variations in temperature and atmospheric pressure were also associated with the higher risk of IA rupture in the next 2 days and 1 day, respectively. CONCLUSION: Temperature and atmospheric pressure have a negative and positive correlation with IA rupture in Fujian, China, respectively. Variation in temperature and atmospheric pressure exert different degrees of hysteresis effects on IA rupture.

Inflammatory lncRNA AK039862 regulates paraquat-inhibited proliferation and migration of microglial and neuronal cells through the Pafah1b1/Foxa1 pathway in co-culture environments.

Emerging evidences having suggested that particular lncRNAs have a potential effect on PD progression through provoking damage and inflammatory responses of microglia/ dopaminergic cells. In addition, paraquat can be accumulated in human body through various approaches and have an increased risk for Parkinson's disease. However, the specific role and mechanism of lncRNA related to neurotoxic in the progression of PD is unclear. In our study, a mouse PD model was established induced by the intraperitoneal injection of paraquat (5 mg/kg and 10 mg/kg) every three days (10 times). We determined differential expression of lncRNA AK039862 and its potential targeted genes Pafah1b1/Foxa1 in PD mouse model, then we used fluorescence in situ hybridization (FISH) to visualize the cellular distribution of AK039862. Short interfering RNAs (siRNAs) and overexpression plasmids were designed for knockdown or overexpression of AK039862. To simulate the coexisting dopaminergic cells and microglia cells in vitro, we applied several non-contact co-culture models, including conditioned medium and Transwell co-culture systems. Cytotoxicity of PQ was evaluated using bv2 cells with the concentrations: 30, 60 µM, and mn9d cells with the concentrations: 50, 100 µM. As a result, we depicted multiple interesting individual and interactive features of inflammatory lncRNA AK039862 involved in PQ-induced cellular functional effects. First, we detected that AK039862 contributed to the neuronal injury process in PQ-treated mice and co-localization of AK039862 with dopaminergic cells in vivo. And interestingly, we demonstrated that PQ significantly inhibited microglia and dopaminergic cells proliferation and microglia migration in vitro. Further research indicated that the PQ-induced low expression of AK039862 rescued microglia proliferation and migration inhibition via the AK039862/Pafah1b1/Foxa1 pathway. Meanwhile, AK039862 also participated in the interaction between microglia and dopaminergic cells with PQ treatment in non-contact co-culture models. In summary, we found that PQ inhibited the proliferation and migration of microglial cells, and elucidated AK039862 played a key role in PQ-induced neuroinflammatory damage through Pafah1b1/Foxa1. Finally, inflammatory AK039862 is involved in the complex communication between microglia and dopaminergic cells in the environment of PQ damage.

Region-specific air pollutants and meteorological parameters influence COVID-19: A study from mainland China.

Coronavirus disease 2019 (COVID-19) was first detected in December 2019 in Wuhan, China, with 11,669,259 positive cases and 539,906 deaths globally as of July 8, 2020. The objective of the present study was to determine whether meteorological parameters and air quality affect the transmission of COVID-19, analogous to SARS. We captured data from 29 provinces, including numbers of COVID-19 cases, meteorological parameters, air quality and population flow data, between Jan 21, 2020 and Apr 3, 2020. To evaluate the transmissibility of COVID-19, the basic reproductive ratio (R0) was calculated with the maximum likelihood "removal" method, which is based on chain-binomial model, and the association between COVID-19 and air pollutants or meteorological parameters was estimated by correlation analyses. The mean estimated value of R0 was 1.79 ± 0.31 in 29 provinces, ranging from 1.08 to 2.45. The correlation between R0 and the mean relative humidity was positive, with coefficient of 0.370. In provinces with high flow, indicators such as carbon monoxide (CO) and 24-h average concentration of carbon monoxide (CO_24 h) were positively correlated with R0, while nitrogen dioxide (NO2), 24-h average concentration of nitrogen dioxide (NO2_24 h) and daily maximum temperature were inversely correlated to R0, with coefficients of 0.644, 0.661, -0.636, -0.657, -0.645, respectively. In provinces with medium flow, only the weather factors were correlated with R0, including mean/maximum/minimum air pressure and mean wind speed, with coefficients of -0.697, -0.697, -0.697 and -0.841, respectively. There was no correlation with R0 and meteorological parameters or air pollutants in provinces with low flow. Our findings suggest that higher ambient CO concentration is a risk factor for increased transmissibility of the novel coronavirus, while higher temperature and air pressure, and efficient ventilation reduce its transmissibility. The effect of meteorological parameters and air pollutants varies in different regions, and requires that these issues be considered in future modeling disease transmissibility.

Reactive oxygen species regulate miR-17-5p expression via DNA methylation in paraquat-induced nerve cell damage.

There is emerging evidence suggesting that oxidative stress and DNA methylation can alter miRNA expression. However, little is known on the mechanism of miR-17-5p expression changes in paraquat (PQ)-induced nerve cell damage. In the present study, neuro-2a cells were pretreated with antioxidant N-acetylcysteine (NAC) or DNA methylation inhibitor decitabine (DAC), then exposed to different concentrations of PQ, while the expression levels of miR-17-5p were detected by qRT-PCR. Here, it is showed that PQ downregulated the expression of miR-17-5p dose-dependently in neuro-2a cells. The DNA methylation level was upregulated after PQ exposure, while downregulated with the pretreatment of NAC in the above content, detected by 5-mC immunofluorescence technique. The interaction effect of NAC and PQ in alternating DNA methylation level was further confirmed by flow cytometry. NAC and DAC individually had an interaction effect in PQ-induced nerve cell damage. After using NAC, PQ-induced ROS elevation and DNA methylation are reduced, thereby preventing the proapoptotic effect of miR-17-5p. Above all, PQ can induce DNA methylation variations through ROS production, leading to the downregulation of miR-17-5p expression in PQ-induced nerve cell damage.

Comparison of the neurotoxicity associated with cobalt nanoparticles and cobalt chloride in Wistar rats.

Cobalt nanoparticles (CoNPs) have been widely used in industry given their physical, chemical and magnetic properties; however, CoNPs may cause neurological symptoms and diseases in human, yet their mechanisms of toxicity remain unknown. Here, we used male Wistar rats to investigate differences in the toxic effects associated with CoNPs and CoCl2. Upon exposure to CoCl2, and 96 nm or 123 nm CoNPs at the same concentration, the Co2+ content in CoCl2 group was significantly higher than that in either the CoNPs groups in brain tissues and blood, but lower in liver. Significant neural damage was observed in both hippocampus and cortex of the temporal lobe. Increase malondialdehyde (MDA) content and CASPASE 9 protein level were associated both with CoCl2 and CoNPs treatments, consistent with lipid perioxidation and apoptosis. Heme oxygenase-1 and (NF-E2) p45-related factor-2 protein levels were elevated in response to 96 nm CoNPs exposure. In PC12 cells, NRF2 downregulation led to reduced cell viability and increased apoptotic rate. In conclusion, both CoNPs and CoCl2 cause adverse neural effects, with nanoparticles showing greater neurotoxic potency. In addition, NRF2 protects neural cells from damage induced by CoCl2 and CoNPs by activating downstream antioxidant responses.

Association of circular RNAs and environmental risk factors with coronary heart disease.

BACKGROUND: Coronary heart disease (CHD) is a complex disease caused by multi-factors and a major threat to human health. Circular RNAs (circRNAs) have critical roles in various biological processes and diseases. This study explores the independent role of circRNAs and their interaction with environmental factors in CHD. METHODS: A case-control study was conducted from March 2015 to September 2017 in Fuzhou, China. A total of 585 CHD patients and 585 gender- and age-matched healthy controls were enrolled. Questionnaire survey, health examination and molecular biology laboratory testing were conducted. Microarray technology and quantitative real-time polymerase chain reaction (PCR) were used to profile the expression levels of circRNAs. The area under the curve (AUC) of the receiver operating characteristic (ROC) was used to determine the diagnostic cut-offs. Multivariate logistic regression and multiplicative analysis were used to analyse the effects of environmental factors and hsa_circ_0008507, hsa_circ_0001946, hsa_circ_0000284 and hsa_circ_0125589 on CHD. RESULTS: The expression profile of circRNAs showed that 3423 circRNAs were differentially expressed at P < 0.05, but none pass multiple testing correction. qRT-PCR further confirmed the expression levels of hsa_circ_0008507, hsa_circ_0001946 and hsa_circ_0000284 in peripheral blood leukocytes in CHD cases were higher than those in non-CHD subjects (All p < 0.05). Hsa_circ_0008507 (OR = 1.29; 95% CI: 1.11-1.50), hsa_circ_0001946 (OR = 1.20; 95% CI: 1.01-1.42) and hsa_circ_0000284 (OR = 2.05; 95% CI: 1.32-3.19) were independent risk factors for CHD after controlling other common environmental risk factors. The AUC for hsa_circ_0008507, hsa_circ_0001946 and hsa_circ_0000284 was 0.75, 0.71 and 0.68, respectively. Compared with non-smoking individuals with low hsa_circ_0008507 expression, the smokers with high hsa_circ_0008507 expression showed the highest magnitude of OR in CHD risk. Additionally, a statistically significant multiplicative interaction was found between hsa_circ_0008507 and smoking for CHD. CONCLUSIONS: Hsa_circ_0008507, hsa_circ_0001946 and hsa_circ_0000284 were closely related to the occurrence and development of CHD. The combination of smoking and high hsa_circ_0008507 expression causes the occurrence and development of CHD.

Comparative mouse lung injury by nickel nanoparticles with differential surface modification.

BACKGROUND: Previous studies have demonstrated that exposure to nickel nanoparticles (Nano-Ni) causes oxidative stress and severe, persistent lung inflammation, which are strongly associated with pulmonary toxicity. However, few studies have investigated whether surface modification of Nano-Ni could alter Nano-Ni-induced lung injury, inflammation, and fibrosis in vivo. Here, we propose that alteration of physicochemical properties of Nano-Ni through modification of Nano-Ni surface may change Nano-Ni-induced lung injury, inflammation, and fibrosis. METHODS: At first, dose-response and time-response studies were performed to observe lung inflammation and injury caused by Nano-Ni. In the dose-response studies, mice were intratracheally instilled with 0, 10, 20, 50, and 100 µg per mouse of Nano-Ni and sacrificed at day 3 post-exposure. In the time-response studies, mice were intratracheally instilled with 50 µg per mouse of Nano-Ni and sacrificed at days 1, 3, 7, 14, 28, and 42 post-instillation. At the end of the experiment, mice were bronchoalveolar lavaged (BAL) and the neutrophil count, CXCL1/KC level, LDH activity, and concentration of total protein in the BAL fluid (BALF) were determined. In the comparative studies, mice were intratracheally instilled with 50 µg per mouse of Nano-Ni or with the same molar concentration of Ni as Nano-Ni of either partially [O]-passivated Nano-Ni (Nano-Ni-P) or carbon-coated Nano-Ni (Nano-Ni-C). At day 3 post-exposure, BAL was performed and the above cellular and biochemical parameters in the BALF were analyzed. The MMP-2/9 protein levels and activities in the BALF and mouse lung tissues were also determined. Mouse lung tissues were also collected for H&E staining, and measurement of thiobarbituric acid reactive substances (TBARS) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the genomic DNA. At day 42 post-exposure, mouse right lung tissues were collected for H&E and Trichrome stainings, and left lung tissues were collected to determine the hydroxyproline content. RESULTS: Exposure of mice to Nano-Ni resulted in a dose-response increase in acute lung inflammation and injury reflected by increased neutrophil count, CXCL1/KC level, LDH activity, and concentration of total protein in the BALF. The time-response study showed that Nano-Ni-induced acute lung inflammation and injury appeared as early as day 1, peaked at day 3, and attenuated at day 7 post-instillation. Although the neutrophil count, CXCL1/KC level, LDH activity, and concentration of total protein in the BALF dramatically decreased over the time, their levels were still higher than those of the controls even at day 42 post-exposure. Based on the results of the dose- and time-response studies, we chose a dose of 50 µg per mouse of Nano-Ni, and day 3 post-exposure as short-term and day 42 post-exposure as long-term to compare the effects of Nano-Ni, Nano-Ni-P, and Nano-Ni-C on mouse lungs. At day 3 post-exposure, 50 µg per mouse of Nano-Ni caused acute lung inflammation and injury that were reflected by increased neutrophil count, CXCL1/KC level, LDH activity, concentration of total protein, and MMP-2/9 protein levels and activities in the BALF. Nano-Ni exposure also caused increased MMP-2/9 activities in the mouse lung tissues. Histologically, infiltration of large numbers of neutrophils and macrophages in the alveolar space and interstitial tissues was observed in mouse lungs exposed to Nano-Ni. Nano-Ni-P exposure caused similar acute lung inflammation and injury as Nano-Ni. However, exposure to Nano-Ni-C only caused mild acute lung inflammation and injury. At day 42 post-exposure, Nano-Ni caused extensive interstitial fibrosis and proliferation of interstitial cells with inflammatory cells infiltrating the alveolar septa and alveolar space. Lung fibrosis was also observed in Nano-Ni-P-exposed lungs, but to a much lesser degree. Only slight or no lung fibrosis was observed in Nano-Ni-C-exposed lungs. Nano-Ni and Nano-Ni-P, but not Nano-Ni-C, caused significantly elevated levels of TBARS in mouse lung tissues and 8-OHdG in mouse lung tissue genomic DNA, suggesting that Nano-Ni and Nano-Ni-P induce lipid peroxidation and oxidative DNA damage in mouse lung tissues, while Nano-Ni-C does not. CONCLUSION: Our results demonstrate that short-term Nano-Ni exposure causes acute lung inflammation and injury, while long-term Nano-Ni exposure causes chronic lung inflammation and fibrosis. Surface modification of Nano-Ni alleviates Nano-Ni-induced pulmonary effects; partially passivated Nano-Ni causes similar effects as Nano-Ni, but the chronic inflammation and fibrosis were at a much lesser degree. Carbon coating significantly alleviates Nano-Ni-induced acute and chronic lung inflammation and injury.

[Interaction between long noncoding RNA and environmental factors on coronary heart disease].

OBJECTIVE: To investigate the role of leukocyte long noncoding RNA(lncRNA) and environmental factors on coronary heart disease(CHD). METHODS: A case-control study was conducted in a hospital in Fuzhou City by using stratified random sampling method during March 2015 and December 2017. The related surveys included questionnaire investigation, physical examination and laboratory detection. And real-time fluorescence quantitative PCR was used to detect the expression of lncRNA(NR_027032, NR_047116 and NR_104181) in case group and control group. Multivariate Logistic regression models and crossover analysis were used to analyze the interaction and association of environmental factors and lncRNA on CHD. RESULTS: Wilcoxon rank sum test indicated that: The expression levels of NR_027032, NR_047116 and NR_104181 in CHD were lower than those in control group, the difference was statistically significant(P<0.05). Multivariate Logistic regression analysis showed that the low expression of NR_027032, NR_047116 and NR_104181 may increase the risk of CHD. Crossover analysis showed that the risk of CHD was 19.053 times(95% CI 5.159-70.361) in the presence of overweight and low expression of NR_047116 than that in the normal condition. And the additive model between the two groups was statistically significant(U=1.999, P=0.046). The evaluation indexes were S=0.598, AP=10.070 and RERI=0.629. CONCLUSION: CHD is the result of environmental factors and genetic factors. The association and additive effect of NR_047116 low expression and overweight may increase the risk of CHD.

Bypass of an Abasic Site via the A-Rule by DNA Polymerase of Pseudomonas aeruginosa Phage PaP1.

The abasic site is one the most common DNA lesions formed in cells; it induces a severe blockage of DNA replication and is highly mutagenic. We continue to use Gp90 exo-, the sole DNA polymerase from Pseudomonas aeruginosa phage PaP1, to study DNA replication upon encountering an abasic site lesion. Gp90 exo- can incorporate dNTPs opposite the abasic site, but extension past this site is extremely slow. Among the four dNTPs, dATP is preferentially incorporated opposite the abasic site, consistent with the A-rule. The incorporation is independent of the identity of the nucleotide 5' of the abasic site. The incorporation of dATP opposite the abasic site occurs by direct incorporation of dNTP opposite the abasic site without a -1 frameshift deletion. Extension from an A:abasic site pair by Gp90 exo- is slightly unfavorable relative to those from other abasic site pairs. Incorporation of dATP opposite the abasic site is preferential and shows a biphasic shape, indicating that this incorporation is much faster than the subsequent dissociation of the polymerase from DNA. The template sequence does not affect the dATP incorporation priority, burst amplitude, burst rate, or dATP dissociation constant. Surface plasmon resonance shows that the presence of an abasic site in the template weakens the binding affinity of Gp90 exo- to DNA in a binary or ternary complex in the presence of any one kind of dNTP. This study reveals that Gp90 exo- preferentially inserts A opposite an abasic site via the A-rule, like other DNA polymerases (e.g., Pol θ, KlenTaq, KF exo-, Pols α, δ/PCNA, and Thermococcus litoralis Pol Vent (exo-)), providing further insight into DNA replication mediated by P. aeruginosa phage PaP1 upon encountering an abasic site lesion.