Benzo[a]pyrene-7,8-diol-9,10-epoxide suppresses the migration and invasion of human extravillous trophoblast HTR-8/SVneo cells by down-regulating MMP2 through inhibition of FAK/SRC/PI3K/AKT pathway

The Effects of Oleic Acid and Palmitic Acid on Porcine Muscle Satellite Cells

We aimed to determine the effects of oleic acid (OA) and palmitic acid (PA), alone or in combination, on proliferation, differentiation, triacylglycerol (TAG) content, and gene expression in porcine muscle satellite cells (PMSCs). Results revealed that OA-alone- and PA + OA-treated PMSCs showed significantly increased viability than those in the control or PA-alone-treated groups. No significant effects on apoptosis were observed in all three treatments, whereas necrosis was significantly lower in OA-alone- and PA + OA-treated groups than in the control and PA-alone-treated groups. Myotube formation significantly increased in OA-alone and PA + OA-treated PMSCs than in the control and PA-alone-treated PMSCs. mRNA expression of the myogenesis-related genes MyoD1 and MyoG and of the adipogenesis-related genes PPARα, C/EBPα, PLIN1, FABP4, and FAS was significantly upregulated in OA-alone- and PA + OA-treated cells compared to control and PA-alone-treated cells, consistent with immunoblotting results for MyoD1 and MyoG. Supplementation of unsaturated fatty acid (OA) with/without saturated fatty acid (PA) significantly stimulated TAG accumulation in treated cells compared to the control and PA-alone-treated PMSCs. These results indicate that OA (alone and with PA) promotes proliferation by inhibiting necrosis and promoting myotube formation and TAG accumulation, likely upregulating myogenesis- and adipogenesis-related gene expression by modulating the effects of PA in PMSCs.

Role of diesel exhaust particle-induced cellular senescence in the development of asthma in young and old mice

BACKGROUND

Although it has been reported that cellular senescence is important in the pathogenesis of asthma, the differential effects of diesel exhaust particle (DEP)-induced cellular senescence on the development of asthma according to age have not been thoroughly studied.

METHODS

We first confirmed that DEP induced cellular senescence in mouse lungs, and then that DEP-induced cellular senescence followed by intranasal instillation of a low-dose house dust mite (HDM) allergen resulted in murine asthma. Second, we examined age-dependent differential effects using 6-week-old (young) and 18-month-old mice (old), and tested whether the mammalian target of the rapamycin (mTOR) pathway plays an important role in this process. Finally, we performed in vitro experiments using human bronchial epithelial cells (HBEC) originating from young and elderly adults to identify the underlying mechanisms.

RESULTS

DEP induced cellular senescence in the airway epithelial cells of young and old mice characterized by increased senescence-associated beta-galactosidase, S100A8/9, and high mobility group box 1 (HMGB1) expressions. DEP-induced cellular senescence with subsequent exposure to a low-dose HDM allergen resulted in asthma in young and old mice. Rapamycin (mTOR pathway inhibitor) administration before DEP instillation significantly attenuated these asthmatic features. In addition, after treatment with a low-dose HDM allergen, S100A9 and HMGB1 over-expressed HBEC originating from young and elderly adults greatly activated co-cultured monocyte-derived dendritic cells (DCs).

CONCLUSIONS

This study showed that DEP-induced senescence made both young and old mice susceptible to allergic sensitization and resultant asthma development by enhancing DC activation. Public health efforts to reduce DEP exposure are warranted.

Transcriptomic and proteomic features of a mouse model of sperm DNA damage induced by benzo(a)pyrene

This study replicated a mouse model of sperm DNA damage induced by benzo(a)pyrene (BaP), and the transcriptomic and proteomic features of the model were examined to clarify the pathways related to BaP-induced damage to sperm DNA. Male mice in the BaP group were subjected to BaP at a dosage of 100 mg/kg/d or an equivalent quantity of saline solution in the control group for 60 days. Subsequently, the DNA fragmentation index (DFI) in sperm was assessed using a sperm chromatin structure assay (SCSA). RNA-seq and data-independent acquisition (DIA) were used to identify the mRNA and protein expression patterns in the testis. The sperm DFI significantly increased in the BaP group. Compared to the control group, the BaP group exhibited differential expression of 240 genes (referred to as DEGs) and 616 proteins (referred to as DEPs). These molecules included Aldh1a1, Cyb5r3, Fads1, Oxsm, Rcn3, and Prss45. Pathways in cancer, the PI3K-Akt signaling pathway, metabolic pathways, and the MAPK signaling pathway were the primary areas where these genes showed enrichment. BaP can damage the DNA of sperm and affect metabolism, the PI3K-Akt pathway, and pathways associated with cancer signaling.

New insight into air pollution-related cardiovascular disease: an adverse outcome pathway framework of PM2.5-associated vascular calcification

Despite the air quality has been generally improved in recent years, ambient fine particulate matter (PM2.5), a major contributor to air pollution, remains one of the major threats to public health. Vascular calcification is a systematic pathology associated with an increased risk of cardiovascular disease. Although the epidemiological evidence has uncovered the association between PM2.5 exposure and vascular calcification, little is known about the underlying mechanisms. The adverse outcome pathway (AOP) concept offers a comprehensive interpretation of all of the findings obtained by toxicological and epidemiological studies. In this review, reactive oxygen species generation was identified as the molecular initiating event (MIE), which targeted subsequent key events (KEs) such as oxidative stress, inflammation, endoplasmic reticulum stress, and autophagy, from the cellular to the tissue/organ level. These KEs eventually led to the adverse outcome, namely increased incidence of vascular calcification and atherosclerosis morbidity. To the best of our knowledge, this is the first AOP framework devoted to PM2.5-associated vascular calcification, which benefits future investigations by identifying current limitations and latent biomarkers.

Lipid Dysregulation Induced by Gasoline and Diesel Exhaust Exposure and the Interaction with Age

Limited knowledge exists regarding gasoline and diesel exhaust effects on lipid metabolism. This study collected gasoline and diesel exhaust under actual driving conditions and conducted inhalation exposure on male young and middle-aged C57BL/6J mice for 4 h/day for 5 days to simulate commuting exposure intensity. Additionally, PM2.5 from actual roadways, representing gasoline and diesel vehicles, was generated for exposure to human umbilical vein endothelial cells (HUVECs) and normal liver cells (LO2) for 24, 48, and 72 h to further investigate exhaust particle toxicity. Results showed that diesel exhaust reduced total cholesterol and low-density lipoprotein cholesterol levels in young mice, indicating disrupted lipid metabolism. Aspartate aminotransferase and alanine aminotransferase levels increased by 53.7% and 21.7%, respectively, suggesting potential liver injury. Diesel exhaust exposure decreased superoxide dismutase and increased glutathione peroxidase levels. Cell viability decreased, and reactive oxygen species levels increased in HUVECs and LO2 following exposure to exhaust particles, with dose- and time-dependent effects. Diesel exhaust particles exhibited more severe inhibition of cell proliferation and oxidative damage compared to gasoline exhaust particles. These findings provide novel evidence of the risk of disrupted lipid metabolism due to gasoline and diesel exhaust, emphasizing the toxicity of diesel exhaust.

TBX3 reciprocally controls key trophoblast lineage decisions in villi during human placenta development in the first trimester

Human trophoblastic lineage development is intertwined with placental development and pregnancy outcomes, but the regulatory mechanisms underpinning this process remain inadequately understood. In this study, based on single-nuclei RNA sequencing (snRNA-seq) analysis of the human early maternal-fetal interface, we compared the gene expression pattern of trophoblast at different developmental stages. Our findings reveal a predominant upregulation of TBX3 during the transition from villous cytotrophoblast (VCT) to syncytiotrophoblast (SCT), but downregulation of TBX3 as VCT progresses into extravillous trophoblast cells (EVT). Immunofluorescence analysis verified the primary expression of TBX3 in SCT, partial expression in MKi67-positive VCT, and absence in HLA-G-positive EVT, consistent with our snRNA-seq results. Using immortalized trophoblastic cell lines (BeWo and HTR8/SVneo) and human primary trophoblast stem cells (hTSCs), we observed that TBX3 knockdown impedes SCT formation through RAS-MAPK signaling, while TBX3 overexpression disrupts the cytoskeleton structure of EVT and hinders EVT differentiation by suppressing FAK signaling. In conclusion, our study suggests that the spatiotemporal expression of TBX3 plays a critical role in regulating trophoblastic lineage development via distinct signaling pathways. This underscores TBX3 as a key determinant during hemochorial placental development.

Targeting scleral remodeling and myopia development in form deprivation myopia through inhibition of EFEMP1 expression

The role of extracellular matrix (ECM) remodeling in the axial elongation associated with myopia has not been fully elucidated, although it is considered a significant factor. EFEMP1, a regulator of ECM, has been associated with various pathological conditions. This study aimed to examine the involvement of EFEMP1 in scleral remodeling during form deprivation myopia. The results indicate a progressive increase in EFEMP1 expression following prolonged form deprivation treatment, followed by a subsequent decrease upon recovery. To gain a deeper understanding of the mechanism of EFEMP1, we conducted transcriptome sequencing on primary scleral fibroblasts that were subjected to lentivirus-mediated overexpression of EFEMP1. Validation was performed using lentivirus-induced overexpression and shRNA targeting EFEMP1 in combination with LY294002, a PI3K inhibitor. Our findings suggest that EFEMP1 may be involved in the development of FDM by regulating the expression of the PI3K/AKT/MMP2 axis. The AAV-mediated injection of shEFEMP1 under Tenon's capsule in guinea pigs was observed to effectively delay the progression of myopia and posterior scleral remodeling. In contrast, the AAV-mediated overexpression of EFEMP1 exacerbated the development of myopia and resulted in further thinning of collagen fibers in the posterior sclera. In summary, adjusting EFEMP1 concentrations could potentially serve as a viable approach to prevent and treat myopia by influencing the remodeling process of the posterior sclera.

Association of urinary polycyclic aromatic hydrocarbon metabolites with gestational diabetes mellitus and gestational hypertension among pregnant women in Southwest China: A cross-sectional study

The association of polycyclic aromatic hydrocarbons (PAHs) with gestational diabetes mellitus (GDM) and gestational hypertension during pregnancy has not yet been established. To investigate the association between PAH exposure and GDM and gestational hypertension, we conducted a cross-sectional study of 4206 pregnant women from the Zunyi birth cohort in southwestern China. Gas chromatography/mass spectrometry was used to detect the urinary levels of 10 monohydroxylated PAHs (OH-PAHs). GDM and gestational hypertension were diagnosed and the relevant information was documented by specialist obstetricians and gynecologists. Logistic regression and restricted cubic spline regression were employed to investigate their single and nonlinear associations. Stratified analyses of pregnancy and body mass index data were conducted to determine their moderating effects on the abovementioned associations. Compared with the first quartile of urinary ∑OH-PAHs, the third or fourth quartile in all study participants was associated with an increased risk of GDM (quartile 3: odds ratio [OR] = 1.35, 95% confidence interval [CI]: 1.03-1.77) and gestational hypertension (quartile 3: OR = 1.88, 95% CI: 1.26-2.81; quartile 4: OR = 1.58, 95% CI: 1.04-2.39), respectively. Nonlinear associations of 1-OH-PYR with GDM (cutoff level: 0.02 μg/g creatinine [Cr]) and 1-OH-PHE with gestational hypertension (cutoff level: 0.06 μg/g Cr) were also observed. In pregnant women with overweight or obesity, 1-OH-PHE and 3-OH-PHE were more strongly associated with gestational hypertension. Our results indicate that exposure to PAH during pregnancy may significantly increase the maternal risks of GDM and gestational hypertension; however, this finding still needs to be confirmed through larger-scale prospective studies and biological evidence.

Jujuboside B post-treatment attenuates PM2.5-induced lung injury in mice

Fine particulate matter (PM2.5) is an air pollutant that causes severe lung injury. We investigated the effects of Jujuboside B (JB), a component of Zizyphi Spinosi Semen, on lung toxicity caused by PM2.5, and we identified the mechanism of its protective effect. Lung injury in an animal model was induced by intratracheal administration of a PM2.5 suspension. After 2 days of PM2.5 pretreatment, mice were administered JB via the tail vein three times over a 2-day period. JB significantly reduced the histological lung damage as well as the lung wet/dry weight ratio. JB also considerably reduced PM2.5-induced autophagy dysfunction, apoptosis, inflammatory cytokine levels, and the number of PM2.5-induced lymphocytes in the bronchial alveolar fluid. We conclude that by regulating TLR2, 4-MyD88, and mTOR-autophagy pathways, JB exerts a protective effect on lung injury. Thus, JB can be used as a potential therapeutic agent for PM2.5-induced lung damage.

Determination of Polycyclic Aromatic Hydrocarbons (PAHs) and Phthalates in Human Placenta by Mixed Hexane/Ether Extraction and Gas Chromatography-Mass Spectrometry/Mass Spectrometry (GC-MS/MS)

In this study, we evaluated the extraction effect of three different extractants, namely hexane + ether (v/v = 3:1), acetonitrile and ethyl acetate, on polycyclic aromatic hydrocarbons (PAHs) and phthalic acid esters (PAEs) in placenta detected and analysed by triple quadrupole gas chromatography-mass spectrometry (GC-MS/MS). The results showed that n-hexane + ether (v/v = 3:1) had the highest extraction efficiency. Under the optimal conditions, the limits of detection (LOD) for the 10 PAHs were 0.003-0.0167 μg/L with relative standard deviations (RSD) of 1.4-5.48% and detection rates of 68.19-107.05%, and the correlation coefficients were (R2, 0.9982-0.9999). The LODs for the nine PAEs were 0.0015-3.5714 μg/L and the correlation coefficients were (R2, 0.9982-0.9999). The limits of detection (S/N = 3) for the nine PAHs were 0.0015-0.5714 μg/L with relative standard deviations (RSD) of 3.15-8.37%, and the detection rates were 80.45-112.59% with correlations of (R2, 0.9972-0.9998). The method was applied to the analysis of PAHs and phthalates in placenta samples from pregnant women. The method's accuracy and applicability were demonstrated. In comparison with other methods for the detection of PAEs and PAHs, the method proposed in this paper has a wider linear range, lower minimum detection limit and comparable recovery with good correlation. This paper is dedicated to providing another method for improving the performance of extracting solid tissues.

Effects of polycyclic aromatic hydrocarbons (PAHs) on pregnancy, placenta, and placental trophoblasts

Polycyclic aromatic hydrocarbons (PAHs) are a group of persistent organic pollutants that are carcinogenic, mutagenic, endocrine-toxic, and immunotoxic. PAHs can be found in maternal and fetal blood and in the placenta during pregnancy. They may thus affect placental and fetal development. Therefore, the exposure levels and toxic effects of PAHs in the placenta deserve further study and discussion. This review aims to summarize current knowledge on the effects of PAHs and their metabolites on pregnancy and birth outcomes and on placental trophoblast cells. A growing number of epidemiological studies detected PAH-DNA adducts as well as the 16 high-priority PAHs in the human placenta and showed that placental PAH exposure is associated with adverse fetal outcomes. Trophoblasts are important cells in the placenta and are involved in placental development and function. In vitro studies have shown that exposure to either PAH mixtures, benzo(a)pyrene (BaP) or BaP metabolite benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) affected trophoblast cell viability, differentiation, migration, and invasion through various signaling pathways. Furthermore, similar effects of BPDE on trophoblast cells could also be observed in BaP-treated mouse models and were related to miscarriage. Although the current data show that PAHs may affect placental trophoblast cells and pregnancy outcomes, further studies (population studies, in vitro studies, and animal studies) are necessary to show the specific effects of different PAHs on placental trophoblasts and pregnancy outcomes.

Effects of Xenobiotic Compounds on Preeclampsia and Potential Mechanisms

Preeclampsia (PE) refers to a disease with new hypertension and albuminuria or other end-organ damage after 20 weeks of pregnancy. As a major complication of pregnancy, PE can increase the morbidity and mortality of pregnant women and fetuses and cause serious social burden. Recently, it has been found that exposure to xenobiotic compounds, especially endocrine disruptors in the environment, may contribute to the development of PE. However, the underlying mechanism is still unclear. It is generally believed that PE is related to placental dysplasia, spiral artery remodelling failure, oxidative stress, etc. Therefore, in order to better prevent the occurrence of PE and reduce the damage and impact on mother and fetus, this paper reviews the role and potential mechanism of PE induced by exogenous chemicals and provides an outlook on the environmental etiology of PE.

BPDE exposure promotes trophoblast cell pyroptosis and induces miscarriage by up-regulating lnc-HZ14/ZBP1/NLRP3 axis

Environmental Benzo(a)pyrene (BaP) and its ultimate metabolite BPDE (benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide) are typical persistent organic pollutants and endocrine disrupting chemicals. BaP/BPDE exposure might cause human trophoblast cell dysfunctions and induce miscarriage. However, the underlying mechanisms remain largely elusive. In this study, we found that BPDE exposure induced human trophoblast cell pyroptosis by up-regulating NLRP3/Caspase1/GSDMD pathway. We also identified that lnc-HZ14 was highly expressed in BPDE-exposed trophoblast cells and in recurrent miscarriage (RM) vs healthy control (HC) villous tissues. Lnc-HZ14 promoted trophoblast cell pyroptosis by promoting IRF1-mediated ZBP1 transcription, increasing METTL3-mediated m6A methylation on NLRP3 mRNA and its stability, and also enhancing ZBP1/NLRP3 protein interactions. Knockdown of lnc-HZ14/ZBP1/NLRP3 axis could efficiently alleviate BPDE-induced trophoblast cell pyroptosis. Higher level of pyroptosis, as indicated by the up-regulation of lnc-HZ14/ZBP1/NLRP3 axis, was found in RM vs HC villous tissues. In BaP-exposed mouse model, BaP exposure induced placental tissue pyroptosis and miscarriage by up-regulating murine Zbp1/Nlrp3 axis, and knockdown of Nlrp3 could efficiently reduce placenta pyroptosis and alleviate BaP-induced mouse miscarriage. Serum IL-1β protein level might act as a promising indicator to predict the risk of miscarriage. These findings provided new insights into BaP/BPDE-induced trophoblast cell pyroptosis and miscarriage and might be helpful for further assessment of the toxicological effects of BaP/BPDE on the female reproduction.

Lnc-HZ03 promotes TRBP-mediated splicing of pre-miR-hz03 to generate miR-hz03 in human trophoblast cells

Benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) leads to dysfunctions of human trophoblast cells and further induces miscarriage. In our previous study, we have found that lnc-HZ03 and miR-hz03 are upregulated in BPDE-exposed human trophoblast cells and in recurrent miscarriage tissues; and the upregulated miR-hz03 caused by lnc-HZ03 further promotes the apoptosis of human trophoblast cells and induces miscarriage. However, how lnc-HZ03 upregulates miR-hz03 is completely unknown. In this study, we find that lnc-HZ03 upregulates the expression level of a transcription factor TFIID (a TATA-binding protein) and promotes TFIID-mediated transactivation response element RNA-binding protein (TRBP) transcription. Subsequently, the upregulated TRBP promotes the maturation of miR-hz03 by splicing its precursor pre-miR-hz03 in human trophoblast cells. In BPDE-exposed trophoblast cells or in recurrent miscarriage tissues, lnc-HZ03 was upregulated, which accelerates the TFIID-mediated TRBP transcription and thus promotes TRBP-mediated miR-HZ03 maturation. Subsequently, the upregulated miR-hz03 further promotes the apoptosis of human trophoblast cells and induces miscarriage. This work provides new insights into the regulation of miRNA expression levels by lncRNAs in BPDE-exposed human trophoblast cells.

Biodiesel feedstock determines exhaust toxicity in 20% biodiesel: 80% mineral diesel blends

To address climate change concerns, and reduce the carbon footprint caused by fossil fuel use, it is likely that blend ratios of renewable biodiesel with commercial mineral diesel fuel will steadily increase, resulting in biodiesel use becoming more widespread. Exhaust toxicity of unblended biodiesels changes depending on feedstock type, however the effect of feedstock on blended fuels is less well known. The aim of this study was to assess the impact of biodiesel feedstock on exhaust toxicity of 20% blended biodiesel fuels (B20). Primary human airway epithelial cells were exposed to exhaust diluted 1/15 with air from an engine running on conventional ultra-low sulfur diesel (ULSD) or 20% blends of soy, canola, waste cooking oil (WCO), tallow, palm or cottonseed biodiesel in diesel. Physico-chemical exhaust properties were compared between fuels and the post-exposure effect of exhaust on cellular viability and media release was assessed 24 h later. Exhaust properties changed significantly between all fuels with cottonseed B20 being the most different to both ULSD and its respective unblended biodiesel. Exposure to palm B20 resulted in significantly decreased cellular viability (96.3 ± 1.7%; p < 0.01) whereas exposure to soy B20 generated the greatest number of changes in mediator release (including IL-6, IL-8 and TNF-α, p < 0.05) when compared to air exposed controls, with palm B20 and tallow B20 closely following. In contrast, canola B20 and WCO B20 were the least toxic with only mediators G-CSF and TNF-α being significantly increased. Therefore, exposure to palm B20, soy B20 and tallow B20 were found to be the most toxic and exposure to canola B20 and WCO B20 the least. The top three most toxic and the bottom three least toxic B20 fuels are consistent with their unblended counterparts, suggesting that feedstock type greatly impacts exhaust toxicity, even when biodiesel only comprises 20% of the fuel.

Lnc-HZ05 regulates BPDE-inhibited human trophoblast cell proliferation and affects the occurrence of miscarriage by directly binding with miR-hz05

Approximately 15-25% pregnant women end with miscarriage in the world. Environmental BaP (benzo(a)pyrene) and its terminal metabolite BPDE (benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide) may result in the dysfunctions of trophoblast cells, which might further lead to RM (recurrent miscarriage). However, potential mechanisms remain unelucidated. In this work, we identified a novel lnc-HZ05 highly expressed and a novel miR-hz05 lowly expressed in both trophoblast cells exposed to BPDE and human RM tissues. MiR-hz05 reduces FOXO3a mRNA level by weakening its mRNA stability. Lnc-HZ05 increases the expression of FOXO3a by acting as a ceRNA for miR-hz05, and then increases P21 level and reduces CDK2 level. Thus, cell cycle is arrested at G0/G1 phase and trophoblast proliferation is inhibited. Lnc-HZ05 harboring wild-type binding site for miR-hz05, but not its mutant site, could upregulate FOXO3a expression. In normal trophoblast cells, relatively less lnc-HZ05 and more miR-hz05 activate FOXO3a/P21/CDK2 pathway and promote trophoblast proliferation, giving normal pregnancy. In RM tissues and BPDE-treated human trophoblast cells, lnc-HZ05 is increased and miR-hz05 is reduced, both of which suppress this pathway and inhibit cell proliferation, and finally lead to miscarriage. Thus, lnc-HZ05 and miR-hz05 simultaneously regulate cell cycle and proliferation of BPDE-exposed trophoblast cells and miscarriage, providing new perspectives and clinical understandings in the occurrence of unexplained miscarriage.

Cirsilineol Treatment Attenuates PM2.5-Induced Lung Injury in Mice

Ultrafine particulate matter with less than 2.5 μm diameter (PM_2.5) is an air pollutant that causes severe lung damage. Currently, effective treatment and preventive methods for PM_2.5-induced lung damage are limited. Cirsilineol (CSL) is a small natural compound isolated from Artemisia vestita. In this study, the efficacy of CSL on PM_2.5-induced lung toxicity was tested, and its mechanism was identified. Lung injury was caused by intratracheal administration of PM_2.5 suspension in animal models. Two days after PM_2.5 pretreatment, CSL was injected via mouse tail vein for two days. The effects of CSL on PM_2.5-induced lung damage, autophagy, apoptosis, and pulmonary inflammation in a mouse model and their mechanisms were investigated. CSL significantly suppressed histological lung damage and lung wet/dry weight proportion. CSL also significantly reduced PM_2.5-induced autophagy dysfunction, apoptosis, lymphocyte suppression, and inflammatory cytokine levels in bronchoalveolar fluid (BALF). Furthermore, CSL increased mammalian target of rapamycin (mTOR) phosphorylation and significantly inhibited the expression of Toll-like receptors (TLR) 2 and 4, MyD88, and the autophagy proteins, Beclin1 and LC3II. Thus, CSL exerts protective effects on pulmonary damage by regulating mTOR and TLR2,4-myD88 autophagy pathways. Therefore, CSL can be used as an effective treatment for PM_2.5-induced lung damage.

Amygdalin attenuates PM2.5-induced human umbilical vein endothelial cell injury via the TLR4/NF-κB and Bcl-2/Bax signaling pathways

Mounting evidence supports that long-term exposure to fine particle pollutants (PM2.5) is closely implicated in cardiovascular diseases, especially atherosclerosis. Amygdalin is reported to attenuate external stimuli-induced cardiovascular diseases. However, the underlying mechanisms are still not understood. In this study, we aim to explore the protective effects of amygdalin on PM2.5-induced human umbilical vein endothelial cell (HUVEC) injury and unravel the specific mechanisms by MTT, DCFH-DA, biochemical, immunofluorescence, ELISA, RT-qPCR, flow cytometry, TUNEL and western blot analysis. The results reveal that amygdalin reverses PM2.5-induced cytotoxicity and attenuates intracellular ROS production. Moreover, amygdalin increases the levels of SOD and GSH and alleviates the MDA content. Additionally, amygdalin causes a decline of IL-6, IL-1β, TNF-α and COX-2 levels. Moreover, amygdalin inhibits NF-κB p50 and TLR4 protein expressions and NF-κB p65 nuclear translocation. Concomitantly, a decline of phospho-NF-κB p65/NF-κB p65 and phospho-IκB-α/IκB-α is detected. Meanwhile, amygdalin pretreatment reduces HUVEC apoptosis. In addition, amygdalin triggers an upregulation of Bcl-2 and a downregulation of Bax after stimulation with PM2.5. Collectively, these results suggest that amygdalin suppresses PM2.5-induced HUVEC injury by regulating the TLR4/NF-κB and Bcl-2/Bax signaling pathways, indicating that amygdalin may be a novel target for atherosclerosis treatments.

Regulatory roles of non-coding RNAs and m6A modification in trophoblast functions and the occurrence of its related adverse pregnancy outcomes

Adverse pregnancy outcomes, such as preeclampsia, gestational diabetes mellitus, fetal growth restriction, and recurrent miscarriage, occur frequently in pregnant women and might further induce morbidity and mortality for both mother and fetus. Increasing studies have shown that dysfunctions of human trophoblast are related to these adverse pregnancy outcomes. Recent studies also showed that environmental toxicants could induce trophoblast dysfunctions. Moreover, non-coding RNAs (ncRNAs) have been reported to play important regulatory roles in various cellular processes. However, the roles of ncRNAs in the regulation of trophoblast dysfunctions and the occurrence of adverse pregnancy outcomes still need to be further investigated, especially with exposure to environmental toxicants. In this review, we analyzed the regulatory mechanisms of ncRNAs and m6A methylation modification in the dysfunctions of trophoblast cells and the occurrence of adverse pregnancy outcomes and also summarized the harmful effects of environmental toxicants. In addition to DNA replication, mRNA transcription, and protein translation, ncRNAs and m6A modification might be considered as the fourth and fifth elements that regulate the genetic central dogma, respectively. Environmental toxicants might also affect these processes. In this review, we expect to provide a deeper scientific understanding of the occurrence of adverse pregnancy outcomes and to discover potential biomarkers for the diagnosis and treatment of these outcomes.

The disruption of human trophoblast functions by autophagy activation through PI3K/AKT/mTOR pathway induced by exposure to titanium carbide (Ti3C2) MXene

Ti₃C₂ MXene, as a novel nanomaterial, has attracted great attention due to its promising properties in biomedical applications. However, the potential effects of Ti₃C₂ MXene on trophoblast functions have not been investigated. Here, we found that Ti₃C₂ MXene exposure weakened the extension ability of villus explants in vitro. We employed human trophoblast HTR-8/SVneo cells to reveal the underlying molecular mechanisms by which Ti₃C₂ MXene exposure affected trophoblast functions. Results showed that Ti₃C₂ MXene entered cells and mostly deposited in the cytoplasm, inhibiting cell migration and invasion abilities. Furthermore, we found that Ti₃C₂ MXene exposure elevated autophagy through the inhibition of the PI3K/AKT/mTOR pathway. Meanwhile, the application of an autophagy inhibitor (3-MA) prevented autophagy and restored cell viability, resulting in the recovery of cell migration and invasion abilities. These indicated that the cellular dysfunction induced by Ti₃C₂ MXene may be mediated by autophagy activation. Our results indicated that autophagy is a key factor in eliciting HTR-8/SVneo dysfunction after Ti₃C₂ MXene exposure, which could therefore damage placental development. Autophagy inhibition is a potential therapeutic strategy for alleviating the placental toxicity of nanoparticles.

The utility of alternative models in particulate matter air pollution toxicology

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Countless unique particulate matter (PM) samples with limited or no toxicity information.

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Alternative in vivo models offer greater throughput than traditional mammalian models.

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Use of zebrafish, fruit flies, and nematodes in PM toxicology lacks systematic review.

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Their utility in PM toxicity and mechanistic research and as screening tools is reviewed.

Exposure to particulate matter (PM) air pollution increases risk of adverse human health effects. As more attention is brought to bear on the problem of PM, traditional mammalian in vivo models struggle to keep up with the risk assessment challenges posed by the countless number of unique PM samples across air sheds with limited or no toxicity information. This review examines the utility of three higher throughput, alternative, in vivo animal models in PM toxicity research: Danio rerio (zebrafish), Caenorhabditis elegans (nematode), and Drosophila melanogaster (fruit fly). These model organisms vary in basic biology, ease of handling, methods of exposure to PM, number and types of available assays, and the degree to which they mirror human biology and responsiveness, among other differences. The use of these models in PM research dates back over a decade, with assessments of the toxicity of various PM sources including traffic-related combustion emissions, wildland fire smoke, and coal fly ash. This article reviews the use of these alternative model organisms in PM toxicity studies, their biology, the various assays developed, endpoints measured, their strengths and limitations, as well as their potential role in PM toxicity assessment and mechanistic research going forward.

Extracellular Vesicle-Derived miR-105-5p Promotes Malignant Phenotypes of Esophageal Squamous Cell Carcinoma by Targeting SPARCL1 via FAK/AKT Signaling Pathway

Objective: Esophageal squamous cell carcinoma (ESCC) presents high morbidity and mortality. It was demonstrated that blood-derived vesicles can facilitate ESCC development and transmit regulating signals. However, the molecular mechanism of vesicle miRNA secreted by tumor cells affecting ESCC progression has not been explored.

Methods: The mRNA-related signaling pathways and differentially expressed genes were screened out in TCGA dataset. The levels of miRNA-105-5p and SPARCL1 were determined by qRT-PCR. Protein level determination was processed using Western blot. The interaction between the two genes was verified with the dual-luciferase method. A transmission electron microscope was utilized to further identify extracellular vesicles (EVs), and co-culture assay was performed to validate the intake of EVs. In vitro experiments were conducted to evaluate cell function changes in ESCC. A mice tumor formation experiment was carried out to observe tumor growth in vivo.

Results: MiRNA-105-5p expression was increased in ESCC, while SPARCL1 was less expressed. MiRNA-105-5p facilitated cell behaviors in ESCC through targeting SPARCL1 and regulating the focal adhesion kinase (FAK)/Akt signaling pathway. Blood-derived external vesicles containing miRNA-105-5p and EVs could be internalized by ESCC cells. Then, miRNA-105-5p could be transferred to ESCC cells to foster tumorigenesis as well as cell behaviors.

Conclusion: EV-carried miRNA-105-5p entered ESCC cells and promoted tumor-relevant functions by mediating SPARCL1 and the FAK/Akt signaling pathway, which indicated that the treatment of ESCC via serum EVs might be a novel therapy and that miRNA-105-5p can be a molecular target for ESCC therapy.

Nickel nanoparticles affect the migration and invasion of HTR-8/SVneo cells by downregulating MMP2 through the PI3K/AKT pathway

Proper migration and invasion of extravillous trophoblast cells into the endometrium in early gestation is essential for successful embryo implantation. The development of nanotechnology has led to the emergence of nickel nanoparticles (Ni NPs), for which attendant health concerns are widespread. Ni NPs are known to affect reproduction and be embryotoxic, but whether they affect the migration and invasion functions of trophoblast cells is unclear. We investigated the effects of Ni NPs on the migration and invasion of HTR-8/SVneo in extravillous trophoblast cells and explored the possible role of the PI3K/AKT/MMP2 signaling pathway in this regard. Results showed that the migration and invasion of cells was significantly inhibited by the exposure of Ni NPs. The protein and mRNA levels of PI3K/AKT/MMP2 signaling pathway were significantly reduced with the increase in Ni NPs concentration. The presence of the PI3K activator 740Y-P partially attenuated the inhibition of cell migration and invasion by Ni NPs, confirming the involvement of this pathway. Thus, Ni NPs inhibit migration and invasion of human trophoblast HTR-8/SVneo cells by downregulating the PI3K/AKT/MMP2 signaling pathway. This study is important for the development of safety evaluation criteria for Ni NPs.

Astragaloside IV pre-treatment attenuates PM2.5-induced lung injury in rats: Impact on autophagy, apoptosis and inflammation

BACKGROUND

Fine particulate matter (PM2.5) with an aerodynamic diameter of less than 2.5 μm, exerts serious lung toxicity. At present, effective prevention measures and treatment modalities for pulmonary toxicity caused by PM2.5 are lacking. Astragaloside IV (AS-IV) is a natural product that has received increasing attention from researchers for its unique biological functions.

PURPOSE

To investigate the protective effects of AS-IV on PM2.5-induced pulmonary toxicity and identify its potential mechanisms.

METHODS

The rat model of PM2.5-induced lung toxicity was created by intratracheal instillation of PM2.5 dust suspension. The investigation was performed with AS-IV or in combination with autophagic flux inhibitor (Chloroquine) or AMP-sensitive protein kinase (AMPK)-specific inhibitor (Compound C). Apoptosis was detected by terminal deoxy-nucleotidyl transferase dUTP nick end labeling (TUNEL) and western blotting. Autophagy was detected by immunofluorescence staining, autophagic flux measurement, western blotting, and transmission electron microscopy. The AMPK/mTOR pathway was analyzed by western blotting. Inflammation was analyzed by western blotting and suspension array.

RESULTS

AS-IV prevented histopathological injury, inflammation, autophagy dysfunction, apoptosis, and changes in AMPK levels induced by PM2.5. AS-IV increased autophagic flux and inhibited apoptosis and inflammation by activating the AMPK/ mammalian target of rapamycin (mTOR) pathway. However, AS-IV had no protective effect on PM2.5-induced lung injury following treatment with Compound C or Chloroquine.

CONCLUSION

AS-IV prevented PM2.5-induced lung toxicity by restoring the balance among autophagy, apoptosis, and inflammation in rats by activating the AMPK/mTOR signaling pathway.

Size-dependent effects of polystyrene nanoplastics on autophagy response in human umbilical vein endothelial cells

Ubiquitous nanoplastics (NPs) increase exposure risks to humans through the food chain and/or other ways. However, huge knowledge gaps exist regarding the fate and adverse impact of NPs on the human cardiovascular system. Autophagy is an important catabolic pathway that disposes of cytoplasmic waste through the lysosomes. In this study, we pursued to determine the interaction and autophagy effect of polystyrene nanoplastics (PS-NPs) (100 and 500 nm in size) on human umbilical vein endothelial cells (HUVECs). The results showed both sizes of PS-NPs interacted with almost all the treated HUVECs in a time- and concentration-dependent manner, and 500 nm PS-NPs were only bound to the surface of cell membranes, whereas 100 nm PS-NPs were taken up by HUVECs and aggregated in the cytoplasm. Furthermore, exposure to 25 μg/mL of 500 nm PS-NPs for 48 h significantly increased lactate dehydrogenase release from HUVECs, while internalized 100 nm PS-NPs not only caused cell membrane damage, but also induced autophagy initiation and autophagosome formation. By a mCherry-GFP-LC3 lentivirus infection assay, we also demonstrated that autophagic flux level was impaired in response to 100 nm PS-NPs. Herein, our results provide new insight into the size-dependent internalization and autophagy response to PS-NPs in HUVECs.

Extravillous trophoblast migration and invasion: Impact of environmental chemicals and pharmaceuticals

During pregnancy, the migration and invasion of extravillous trophoblasts (EVTs) into the maternal uterus is essential for proper development of the placenta and fetus. During the first trimester, EVTs engraft and remodel maternal spiral arteries allowing for efficient blood flow and the transfer of essential nutrients and oxygen to the fetus. Aberrant migration of EVTs leading to either shallow or deep invasion into the uterus has been implicated in a number of gestational pathologies including preeclampsia, fetal growth restriction, and placenta accreta spectrum. The migration and invasion of EVTs is well-coordinated to ensure proper placentation. However, recent data point to the ability of xenobiotics to disrupt EVT migration. These xenobiotics include heavy metals, endocrine disrupting chemicals, and organic contaminants and have often been associated with adverse pregnancy outcomes. In most instances, xenobiotics appear to reduce EVT migration; however, there are select examples of enhanced motility after chemical exposure. In this review, we provide an overview of the 1) current experimental approaches used to evaluate EVT migration and invasion in vitro, 2) ability of environmental chemicals and pharmaceuticals to enhance or retard EVT motility, and 3) signaling pathways responsible for altered EVT migration that are sensitive to disruption by xenobiotics.

Effects of palmitic acid and eicosapentaenoic acid on angiogenesis of porcine vascular endothelial cells

Restricted placental angiogenesis is an important cause of intrauterine growth retardation in piglets. During pregnancy, sow obesity can result in an increase in placental lipid deposition, subsequently inhibiting placental angiogenesis and fetal development. However, the effect of different types of fatty acids on placental angiogenesis is still unclear. Trophoblast cells and vascular endothelial cells constitute two important types of placental tissue. In this study, we used palmitic acid (C16:0) and eicosapentaenoic acid (C20:5, n-3), respectively, to treat porcine trophectoderm cells (pTr2) and porcine iliac artery endothelial cells (PIEC) to study the effects of saturated fatty acids and n-3 polyunsaturated fatty acids (PUFAs) on placental angiogenesis in vitro. We found that C16:0 caused significant cytotoxicity in pTr2 and PIEC (p < 0.01) and inhibited the proliferation and migration of PIEC (p < 0.01), whereas C20:5 treatment exhibited very low cytotoxicity and minimal inhibition of cellular proliferation. Meanwhile, a low concentration of C16:0 had no effect on the tube formation in PIEC, whereas C20:5 significantly promoted tube formation of PIEC (p < 0.01). These results suggested that saturated fatty acids and n-3 PUFAs had different effects on placental angiogenesis. As essential functional fatty acid, n-3 PUFA might be effective measure in alleviating the placental lipotoxicity caused by sow obesity during pregnancy.

Malignant transformation of human bronchial epithelial cells induced by benzo [a] pyrene suggests a negative feedback of TP53 to PPP1R13L via binding a possible enhancer element

Previous studies have shown that PPP1R13L as an inhibitor of apoptosis protease TP53 can lead to abnormal cell proliferation and carcinogenesis, however, the function of PPP1R13L was complicated and the interaction between TP53 and PPP1R13L needs to be further explored. In the present study, a malignant transformation model of human bronchial epithelial cells induced by benzo (a) pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) was established to observe the regulatory patterns between TP53 and PPP1R13L during carcinogenesis. In vitro experiments including CRISPR-Cas9 editing, RNA silence, Co-Immunoprecipitation and Chromatin Immunoprecipitation were applied to discuss their interactive effects. Additionally, TCGA data profile and our clinical samples of lung cancer were also used to analyze their relationship at the transcriptome level. Interestingly, we found that the mRNA and protein level of TP53 and PPP1R13L fluctuated as a wave in BPDE-induced malignant transformation under wild-type TP53 genetic background. Our results have also demonstrated that PPP1R13L acts as an inhibitor of TP53, while TP53 can regulate PPP1R13L via binding a possible enhancer of the first intron of PPP1R13L gene. Likewise, TCGA data and clinical samples have identified that in the case of TP53 mutation, TP53 expression was negatively correlated with PPP1R13L, while in the case of TP53 wild-type, TP53 expression was not correlated with PPP1R13L. It suggested that there existed a negative feedback of wild-type TP53 to PPP1R13L, which reminded a unique implication during chemical carcinogenesis.

The involvement of DRP1-mediated caspase-1 activation in inflammatory response by urban particulate matter in EA.hy926 human vascular endothelial cells

Atmospheric particulate matter (PM) has been reported to be closely related to cardiovascular adverse events. However, the underlying mode of action remains to be elucidated. Previous studies have documented that PM induces mitochondrial damage and inflammation, the relation between these two biological outcomes is still unclear though. In this study, we used EA.hy926 human vascular endothelial cells and a standard PM, PM SRM1648a to study the potential effects of mitochondrial dysfunction on endothelial inflammatory responses. As a result, PM SRM1648a changes mitochondrial morphology and interrupts mitochondrial dynamics with a persistent tendency of fission in a dose-dependent manner. Additionally, the caspase-1/IL-1β axis is involved in inflammatory responses but not cell pyroptosis in EA.hy926 cells following the exposure to PM SRM1648a. The activation of caspase-1 has implications in inflammation but not pyroptosis, because caspase-1-dependent pyroptosis is not the main modality of cell death in PM SRM1648a-treated EA.hy926 cells. With regard to the association between mitochondrial damage and inflammation in the case of particle stimulation, DRP1-mediated mitochondrial fission is responsible for inflammatory responses as a result of caspase-1 activation. The current study showed that PM SRM1648a has the ability to disturb mitochondrial dynamics, and trigger endothelial inflammation via DRP1/caspase-1/IL-1β regulatory pathway. In a conclusion, mitochondrial fission enables EA.hy926 cells to facilitate caspase-1 activation in response to PM SRM1648a, which is a crucial step for inflammatory reaction in vascular endothelial cells.

Ambient particulate matter triggers defective autophagy and hijacks endothelial cell renewal through oxidative stress-independent lysosomal impairment

Ambient particulate matter (APM) has been authenticated to exert hazards on human vascular endothelial cells, including abnormal autophagy. However, the potential reasons for autophagosome accumulation are still obscure. Since autophagy is a dynamic process, it is imperative to systemically consider the autophagic induction combined with its degradation to reflect realistic scenarios. Therefore, in the current study, different exposure durations were initially employed for the detection of autophagic marker proteins to assess the dynamic autophagic state preliminarily. Additionally, LC3 turn-over and autophagic flux assays were used to determine the specific cause of LC3II upregulation in EA.hy926 human vascular endothelial cells by a type of standard urban particulate matter, PM SRM1648a. As a result, PM SRM1648a stimulates excess autophagic vacuoles in EA. hy926 cells, in which the underlying causes are probably different at varying incubation endpoints. Intriguingly, LC3II upregulation was due to the intensifying autophagic initiation after 6 h of exposure, whereas as exposure period was extended to 24 h, overloaded autophagic vacuoles were attributed to the defective autophagy. Mechanistically, PM SRM1648a damages EA. hy926 cells by inducing lysosomal disequilibrium and resultant autophagic malfunction which are not directly mediated by oxidative stress. These data indicate that appropriate maintenance of lysosomal function and autophagic flux is probably a protective measure against APM-induced endothelial cell damage.

Lnc-HZ01 with m6A RNA methylation inhibits human trophoblast cell proliferation and induces miscarriage by up-regulating BPDE-activated lnc-HZ01/MXD1 positive feedback loop

Environmental BaP (benzo(a)pyrene) and its metabolite BPDE (benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide) inhibit proliferation of human villous trophoblast cells, which might further induce recurrent miscarriage (RM). However, the underlying mechanisms remain largely unknown. In this work, we identified a novel lncRNA HZ01 (lnc-HZ01) that is up-regulated in both RM tissues and BPDE-exposed trophoblast cells. Lnc-HZ01 inhibits trophoblast cell proliferation and induces miscarriage. Mechanistically, lnc-HZ01 promotes MXD1 mRNA transcription by up-regulating its transcription factor c-JUN and also enhances MXD1 protein stability by up-regulating its deubiquitin enzyme USP36. Reversely, MXD1 up-regulates lnc-HZ01 level by enhancing its RNA stability due to the increased level of m6A RNA methylation on lnc-HZ01, the first example that m6A modification regulates trophoblast cell functions. Thus, lnc-HZ01 and MXD1 comprise a positive self-feedback loop, which is up-regulated in both RM tissues and BPDE-exposed trophoblast cells. Once this loop is activated by BaP or BPDE exposure, both pathways in this loop would be up-regulated, promote EIF4E transcription, inhibit trophoblast cell proliferation, and further induce miscarriage. This work provides new clinical and scientific understanding in unexplained miscarriage.

Environmental Pollutant Benzo[a]pyrene Upregulated Long Non-coding RNA HZ07 Inhibits Trophoblast Cell Migration by Inactivating PI3K/AKT/MMP2 Signaling Pathway in Recurrent Pregnancy Loss

Benzo(a)pyrene (BaP) is a ubiquitous environmental endocrine-disrupting chemical that is known to have toxic effects on reproduction. However, the underlying mechanisms describing how BaP and its metabolite benzo[a]pyrene-7, 8-diol-9, 10-epoxide (BPDE) induce recurrent pregnancy loss (RPL) are still largely unclear. In this study, we identified a novel long non-coding RNA (lnc-HZ07, NCBI MT936329) that was upregulated in trophoblast cells after exposure to BPDE, and lnc-HZ07 expression was significantly higher in RPL villous tissues than that in control villous tissues. Knockdown of lnc-HZ07 promoted trophoblast cell migration, whereas overexpression of lnc-HZ07 inhibited trophoblast cell migration. Further study showed that lnc-HZ07 inhibited trophoblast migration by downregulating matrix metalloproteinase 2 (MMP2) expression via dephosphorylation of AKT. These results demonstrated a novel regulatory pathway in which BaP downregulated AKT phosphorylation and inhibited MMP2 expression by upregulating lnc-HZ07, suggesting that lnc-HZ07 could be considered as a potential pathological marker of BaP-induced RPL and therapeutic target for this disease.

Hyperoside relieves particulate matter-induced lung injury by inhibiting AMPK/mTOR-mediated autophagy deregulation

Autophagy-mediated cell death plays a critical role in the pathogenesis of PMs-induced lung injury. Hyperoside (Hyp), a flavonoid glycosides, is known to exert protective effects on many diseases by inhibiting autophagic activity. The current study aimed to explore the protective effect and mechanism of Hyp against PMs-induced lung injury in PM2.5 challenged Beas-2b cells in vitro and BALB/C mice in vivo. In vitro, we found that the organic solvent-extractable fraction of SRM1649b (O-PMs) caused more severe cytotoxicity in Beas-2b cells than the water solvent-extractable fraction of SRM1649b (W-PMs). O-PMs treatment dose-dependently upregulated the expression of autophagy markers (beclin-1, p62, atg3 and LC3II) and apoptotic proteins. This cytotoxicity of O-PMs was attenuated by Hyp pretreatment in parallel with downregulation of the expression of autophagy markers, apoptotic proteins, and p-AMPK and upregulation of p-mTOR expression. Notably, the therapeutic effect of Hyp was attenuated by pretreated with AICAR (an AMPK inducer), but enhanced by CC and 3-MA treatment. In vivo, Hyp reduced pathological lung injury and decreased the levels of PMs-induced inflammatory cytokines (TNF-α and IL-6), and the number of total cells in the BALF by inhibiting AMPK/mTOR signaling. Furthermore, cotreatment with AICAR (500 mg/kg) reduced but did not abrogate the pulmonary protective effect of Hyp. These findings indicate that Hyp protects against PMs-induced lung injury by suppressing autophagy deregulation and apoptosis through regulation of the AMPK/mTOR pathway.

Lnc-HZ08 regulates BPDE-induced trophoblast cell dysfunctions by promoting PI3K ubiquitin degradation and is associated with miscarriage

Increasing evidences have shown that pregnant women might miscarry after exposure with environmental BaP (benzo(a)pyrene). Additionally, BPDE (benzo(a)pyren-7,8-dihydrodiol-9,10-epoxide), the ultimate metabolite of BaP, could induce dysfunctions of human trophoblast cells. However, it is rarely correlated between miscarriage and trophoblast dysfunctions. Moreover, their underlying mechanisms are still largely unidentified. In this study, a novel lncRNA (long non-coding RNA), lnc-HZ08, was identified to be highly expressed in human recurrent miscarriage (RM) tissues and in BPDE-treated human trophoblast cells. Lnc-HZ08 acts as a RNA scaffold to interact with both PI3K and its ubiquitin ligase CBL (Cbl proto-oncogene), enhances their protein interactions, and promotes PI3K ubiquitin degradation. In RM tissues and BPDE-treated trophoblast cells, DNA methylation level in lnc-HZ08 promoter region was reduced, which promotes estrogen receptor 1 (ER)-mediated lnc-HZ08 transcription. Subsequently, this upregulated lnc-HZ08 downregulated PI3K level, suppressed PI3K/p-AKT/p-P21/CDK2 pathway, and thus weakened proliferation, migration, and invasion of human trophoblast cells, which further induces miscarriage. These results may provide novel scientific and clinical insights in the occurrence of unexplained miscarriage. A novel lncRNA (lnc-HZ08) regulates the functions of human trophoblast cells and affects miscarriage. Lnc-HZ08 promotes PI3K ubiquitin degradation by enhancing CBL and PI3K interactions, downregulates PI3K/p-AKT/p-P21/CDK2 pathway, and weakens proliferation, migration, and invasion of trophoblast cells. BPDE exposure reduces the DNA methylation level in lnc-HZ08 promoter region and promotes estrogen receptor 1 (ER)-mediated lnc-HZ08 transcription. The suppressed PI3K/p-AKT/p-P21/CDK2 pathway regulated by increased lnc-HZ08 is associated with miscarriage. These results provide novel insights in the occurrence of unexplained miscarriage. Graphical Headlights • Lnc-HZ08 downregulates PI3K/p-AKT/p-P21/CDK2 pathway to suppress proliferation, migration, and invasion of human trophoblast cells, and affects miscarriage. • Lnc-HZ08 acts as a RNA scaffold to enhance the protein interaction of PI3K and its ubiquitin ligase CBL, which increases PI3K ubiquitination and degradation. • Lnc-HZ08 transcription is associated with DNA methylation on its promoter region and transcription factor ER.

Upregulated lnc-HZ02 and miR-hz02 inhibited migration and invasion by downregulating the FAK/SRC/PI3K/AKT pathway in BPDE-treated trophoblast cells

BPDE (benzo(a)pyren-7,8-dihydrodiol-9,10-epoxide), a metabolite of environmental carcinogenic BaP, weakens the migration and invasion of human villous trophoblast cells and may further induce miscarriage. However, the underlying mechanisms remain largely unknown. In this study, we identified that in trophoblast Swan 71 and HTR-8/SVneo cells, miR-hz02 upregulates the level of lnc-HZ02, which inhibits the expression of an RNA-binding protein HuR. HuR could interact with FAK mRNA and promote its mRNA stability, thus upregulating the FAK level and the FAK/SRC/PI3K/AKT pathway, and finally maintaining the normal migration and invasion of trophoblast cells. If trophoblast cells are exposed to BPDE, both miR-hz02 and lnc-HZ02 are upregulated, which reduce the level of HuR, weaken the interactions of HuR with FAK mRNA, downregulate FAK level and the FAK/SRC/PI3K/AKT pathway, and finally inhibit cell migration and invasion. This study provides a novel scientific understanding of the dysfunctions of human trophoblast cells.

Atmospheric particulate matter impedes autophagic flux by impairing lysosomal milieu and integrity in human umbilical vein endothelial cells (HUVECs)

Autophagy is a dynamic process for waste disposal and cell equilibrium. Previous studies have demonstrated that atmospheric particulate matter (APM) induces autophagy and enhances LC3II expression in human vascular endothelial cells. However, the underlying mechanism of autophagosome accumulation in human vascular endothelial cells under the exposure to APM has not been understood. In principle, the upregulation of LC3II or autophagosomes accumulation is presumably caused by the enhancement of autophagic ability, or alternatively, by the abnormal autophagic degradation. Therefore, in the current study, autophagic ability and autophagic flux are systemically studied to decipher the exact cause of autophagosomes accumulation in human umbilical vein endothelial cells (HUVECs) in response to a standard urban particulate matter, PM SRM1648a. As a result, it was observed that after 24 h of exposure, PM SRM1648a significantly increases LC3II expression with apparent autophagosomes accumulation in HUVECs. Compared with the control group, there is a time-dependent increase in p62, a protein of autophagic substrate that can be preliminarily used to evaluate the autophagic degradation, in the PM SRM1648a-exposed HUVECs, which suggested that normal function of autophagic degradation was probably impaired. Additionally, mRFP-GFP-LC3 assay and LAMP-2/LC3B co-localization suggested that autolysosomes (fusion between autophagosomes and lysosomes) were partially inhibited in PM SRM1648a-treated HUVECs. Furthermore, LC3II turn-over assay hinted that after 24 h, LC3II upregulation is attributed to the blockage of autophagic flux instead of the enhancement of autophagic induction. Mechanistically, the blockade of autophagic flux can be explained by the detrimental effects of PM SRM1648a on lysosomal function, including lysosomal destabilization, lysosomal alkalization and hydrolase inactivation, which are involved in the blockade of fusion between autophagosomes and lysosomes, further disrupting autophagic degradation and waste disposal. These observations provide evidence that PM SRM1648a destroys the equilibrium of lysosomal stability and thus results in the dysfunction of autophagic flux, eventually contributing to endothelial cell damage.

Novel lnc-HZ03 and miR-hz03 promote BPDE-induced human trophoblastic cell apoptosis and induce miscarriage by upregulating p53/SAT1 pathway

Normal pregnancy is essential for human reproduction. However, environmental BaP (benzo(a)pyrene) and its metabolite BPDE (benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide) induce dysfunctions of human trophoblastic cells, which could further result in miscarriage. Yet, the molecular mechanisms remain poorly understood. In this work, a novel lnc-HZ03 and a novel miR-hz03 were identified. Both lnc-HZ03 and miR-hz03 were highly expressed in human recurrent miscarriage villous tissues and in BPDE-exposed trophoblastic cells. Lnc-HZ03 and miR-hz03 upregulated each other, forming a positive feedback loop. MiR-hz03 could also upregulate p53 level by enhancing its mRNA stability. Both lnc-HZ03 and p53 mRNA contained the target site for miR-hz03 and could directly interact with miR-hz03. It was this target site instead of its mutant on lnc-HZ03 that regulated p53 expression. Subsequently, the upregulated p53 facilitated SAT1 transcription and enhanced SAT1-catalyzed spermine metabolism, which further resulted in trophoblastic cell apoptosis and induced miscarriage. All together, the p53/SAT1 pathway upregulated by lnc-HZ03 and miR-hz03 could promote BPDE-induced human trophoblastic cell apoptosis and the occurrence of miscarriage, shedding novel light on the causes of miscarriage. Graphical abstract Lnc-HZ03 and miR-hz03 regulate the occurrence of recurrent miscarriage (RM). In human trophoblastic cells, lnc-HZ03 upregulates miR-hz03 level. MiR-hz03 increases the RNA stability of lnc-HZ03 and p53 mRNA. P53 promotes SAT1 transcription and reduces its cellular spermine content, resulting in cell apoptosis. Under normal conditions, lnc-HZ03/miR-hz03 and p53/SAT1 pathways are downregulated, maintaining normal pregnancy. After exposure to BPDE, lnc-HZ03/miR-hz03 and p53/SAT1 pathways are upregulated and finally induce miscarriage.

New insight into the negative impact of imidazolium-based ionic liquid [C10mim]Cl on Hela cells: From membrane damage to biochemical alterations

As an alternative to volatile organic solvents, ionic liquids (ILs) are known as "green solvents", and widely used in industrial applications. However, due to their high solubility and stability, ILs have tendency to persist in the water environment, thus having potential negative impacts on the aquatic ecosystem. For assessing the environmental risks of ILs, a fundamental understanding of the toxic effects and mechanisms of ILs is needed. Here we evaluated the cytotoxicity of 1-methyl-3-decylimidazolium chloride ([C₁₀mim]Cl) and elucidated the main toxic mechanism of [C₁₀mim]Cl in human cervical carcinoma (Hela) cells. Microstructural analysis revealed that [C₁₀mim]Cl exposure caused the cell membrane breakage, swollen and vacuolated mitochondria, and spherical cytoskeletal structure. Cytotoxicity assays found that [C₁₀mim]Cl exposure increased ROS production, decreased mitochondrial membrane potential, induced cell apoptosis and cell cycle arrest. These results indicated that [C₁₀mim]Cl could induce damage to cellular membrane structure, affect the integrity of cell ultrastructure, cause the oxidative damage and ultimately lead to the inhibition of cell proliferation. Moreover, alterations of biochemical information including the increased ratios of unsaturated fatty acid and carbonyl groups to lipid, and lipid to protein, and the decreased ratios of Amide I to Amide II, and α-helix to β-sheet were observed in [C₁₀mim]Cl treated cells, suggesting that [C₁₀mim]Cl could affect the structure of membrane lipid alkyl chain and cell membrane fluidity, promote the lipid peroxidation and alter the protein secondary structure. The findings from this work demonstrated that membrane structure is the key target, and membrane damage is involved in [C₁₀mim]Cl induced cytotoxicity.

Toxicological Effects of BPDE on Dysfunctions of Female Trophoblast Cells

Polycyclic aromatic hydrocarbons (PAHs) are widely spread persistent environmental toxicants. Its typical representative benzo[a]pyrene (BaP) is a human carcinogen. BaP can pass through the placental barrier and is finally metabolized into benzo[a]pyren-7, 8-dihydrodiol-9, 10-epoxide (BPDE). BPDE can form DNA adducts, which directly affect the female reproductive health. Based on the special physiological functions of trophoblast cells and its important effect on normal pregnancy, this chapter describes the toxicity and molecular mechanism of BPDE-induced dysfunctions of trophoblast cells. By affecting the invasion, migration, apoptosis, proliferation, inflammation, and hormone secretion of trophoblast cells, BPDE causes diseases such as choriocarcinoma, intrauterine growth restriction, eclampsia, and abortion. In the end, it is expected to provide a scientific basis and prevention approach for women's reproductive health and decision-making basis for the formulation of environmental health standards.

Mitochondrial Dynamics in Placenta-Derived Mesenchymal Stem Cells Regulate the Invasion Activity of Trophoblast

Mitochondrial dynamics are involved in many cellular events, including the proliferation, differentiation, and invasion/migration of normal as well as cancerous cells. Human placenta-derived mesenchymal stem cells (PD-MSCs) were known to regulate the invasion activity of trophoblasts. However, the effects of PD-MSCs on mitochondrial function in trophoblasts are still insufficiently understood. Therefore, the objectives of this study are to analyze the factors related to mitochondrial function and investigate the correlation between trophoblast invasion and mitophagy via PD-MSC cocultivation. We assess invasion ability and mitochondrial function in invasive trophoblasts according to PD-MSC cocultivation by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and extracellular flux (XF) assay. Under PD-MSCs co-cultivation, invasion activity of a trophoblast is increased via activation of the Rho signaling pathway as well as Matrix metalloproteinases (MMPs). Additionally, the expression of mitochondrial function (e.g., reactive oxygen species (ROS), calcium, and adenosine triphosphate (ATP) synthesis) in trophoblasts are increased via PD-MSCs co-cultivation. Finally, PD-MSCs regulate mitochondrial autophagy factors in invasive trophoblasts via regulating the balance between PTEN-induced putative kinase 1 (PINK1) and parkin RBR E3 ubiquitin protein ligase (PARKIN) expression. Taken together, these results demonstrate that PD-MSCs enhance the invasion ability of trophoblasts via altering mitochondrial dynamics. These results support the fundamental mechanism of trophoblast invasion via mitochondrial function and provide a new stem cell therapy for infertility.

The unique applicability of the human placenta to the Adverse Outcome Pathway (AOP) concept: the placenta provides fundamental insights into human organ functions at multiple levels of biological organization

Despite the short lifespan of the human placenta, the proper formation and function of the organ is of crucial importance for fetal development. Placental dysfunction increases the risk of complications for mother and child during pregnancy and childbirth and beyond as it predisposes to fetal programming. The placenta is an upstream organ of the fetus. It performs the functions of fetal lungs, liver, intestines, kidneys and glands as long as these organs are not fully functional. Furthermore, it is the only human organ that is non-invasively available either after elective abortion or after birth. This is a crucial point given that the conceptual framework of Adverse Outcome Pathway (AOP) requires data on organ function. In vitro and ex vivo placental studies, combined with epidemiological and clinical data on pregnant women, newborns, and infants can uniquely cover all levels of information needed to develop new AOPs and complement existing AOPs related to reproductive toxicity and beyond. To stimulate further research in this area and to support researchers in future studies dealing with the development of AOPs related to the placenta, this review first gives a brief description of placental structure, placental development and relevant pregnancy diseases. The state of knowledge about the available placental models, their particularities and limitations are briefly discussed. Finally, the use of placental research for the development of AOPs is presented with an illustrative example.

Downregulation of cAMP-Dependent Protein Kinase Inhibitor-b Promotes Preeclampsia by Decreasing Phosphorylated Akt

Preeclampsia is a multi-system disease that is unique to human pregnancy. Impaired extravillous trophoblast migration and invasion accompanied by poor spiral vascular remodeling is thought to be the initial reason. This study investigated cAMP-dependent protein kinase inhibitor-b(PKIB) expression in placentas and its involvement in the pathogenesis of PE. We used immunohistochemistry and western blotting to calculate PKIB levels in the placentas. Then we knocked down PKIB by siRNA and used real-time cell analysis to assess the invasion and migration ability of trophoblasts. Tube formation assay and spheroid sprouting assay were utilized to identify the ability to form vessels of trophoblasts. At last, western blotting was used to demonstrate the level of phosphorylated Akt, as well as downstream-related genes of Akt signaling pathway in trophoblasts. We first found that PKIB expression level was lower in the PE placentas than in the normal placentas. In addition, we found that downregulation of PKIB can inhibit the migration, invasion, and the ability to form vessels of HTR8/SVneo cells. Downregulation of PKIB leaded to a decrease in phosphorylated Akt, as well as downstream proteins such as matrix metalloproteinase 2, matrix metalloproteinase 9, and glycogen synthase kinase 3β, which are related to migration and invasion. Our study revealed that the downregulation of PKIB expression resulted in decreased migration, invasion, and vessel formation ability by regulating Akt signaling pathway in placental trophoblasts in PE.

miR-338-5p Targets Epidermal Growth Factor-Containing Fibulin-Like Extracellular Matrix Protein 1 to Inhibit the Growth and Invasion of Trophoblast Cells in Selective Intrauterine Growth Restriction

Selective intrauterine growth restriction (sIUGR) is a disorder of monochorionic (MC) twin pregnancies. However, the underlying mechanism remains largely unknown. Trophoblast cells are the major component of the placenta. Dysfunction of trophoblast cells is associated with placental dysfunction. Our previous study identified miR-338-5p is downregulated in placenta tissues sharing larger twins of sIUGR. In the present study, we aimed to investigate the role of miR-338-5p in trophoblast cells and explored its target. Our results further indicated that miR-338-5p was downregulated in placental tissues supporting larger twins of sIUGR, whereas epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) was upregulated. Moreover, miR-338-5p overexpression suppressed the growth and invasion of trophoblast cells. Importantly, results from luciferase reporter assay demonstrated that miR-338-5p bound on the 3'-UTR of EFEMP1. miR-338-5p suppressed the growth and invasion of trophoblast cells via targeting EFEMP1. Further, miR-338-5p/EFEMP1 might disrupt the function of trophoblast cells via inhibiting the phosphorylation of AKT.

Exposure to airborne fine particulate matter is associated with impaired endothelial function and biomarkers of oxidative stress and inflammation

Epidemiological evidence suggests that exposure to air pollution is a leading risk factor for cardiovascular disease (CVD). However, there is little direct evidence linking exposure to vascular dysfunction. We conducted a cross-sectional study of 100 participants, recruited from the University of Louisville Clinics. Endothelial function was assessed by calculating the reactive hyperemia index (RHI). Oxidative stress was indexed by measuring urinary levels of isoprostanes (n = 91). Inflammatory biomarkers were measured in the plasma (n = 80). Daily average PM_2.5 levels were obtained from regional monitoring stations. Adjusted associations between PM_2.5 levels and measured outcomes were tested using generalized linear models. The average age of participants was 48 years (44% male, 62% white); 52% had a diagnosis of hypertension, and 44% had type-2 diabetes. A 12.4% decrease in RHI was associated with 10 μg/m³ increase in PM_2.5 (95% CI: 21.0, -2.7). The F-2 isoprostane metabolite showed a positive association of 28.4% (95% CI: 2.7, 60.3) per 10 μg/m³ increase in PM_2.5. Positive associations were observed with angiopoietin 1 (17.4%; 95% CI: 2.8, 33.8), vascular endothelial growth factor (10.4%; 95% CI: 0.6, 21.0), placental growth factor (31.7%; 95% CI: 12.2, 54.5), intracellular adhesion molecule-1 (24.6%; 95% CI: 1.6, 52.8), and matrix metalloproteinase-9 (30.3%; 95% CI: 8.0, 57.5) per 10 μg/m³ increase in PM_2.5. Additionally, a 10 μg/m³ increase in PM_2.5 was associated with 15.9% decrease in vascular cell adhesion molecule-1 (95% CI: 28.3, -1.3). These findings suggest that exposure to PM_2.5 is associated with impaired vascular function, which may result from oxidative stress and inflammation, thereby leading to a pro-atherogenic state.

Down-regulated long non-coding RNA PVT1 contributes to gestational diabetes mellitus and preeclampsia via regulation of human trophoblast cells

OBJECTIVE

We aimed to explore the expression level and biological function of lncRNA PVT1 in human trophoblast cells.

METHODS

The expression levels of PVT1 in cancer cell lines, HTR8/SVneo cell, HUVEC cell, the maternal placenta of GDM patients, PE patients and normal pregnancy were detected by qRT-PCR. The cell culture, cell transfection, CCK-8 assay, flow cytometry, wound scratch assay and transwell were carried out to determine the effects of silencing and overexpression of PVT1 on the HTR8/SVneo trophoblast cell line. Nuclear and chromatin RNA fraction assay, RNA-sequencing, western blot and qRT-PCR were conducted to preliminarily explore possible mechanisms.

RESULTS

The relative PVT1 expression level in HTR-8/Svneo cells was higher compared to other cancer cells and HUVEC, and was lower in the GDM and PE placentas than in the normal placentas. The results showed that PVT1 knockdown notably inhibited the proliferation, migration and invasiveness abilities of trophoblast cells, and significantly promoted the apoptosis. Furthermore, overexpression of PVT1 showed the opposite results. We identified 105 differentially expressed genes after PVT1 knockdown, 23 were up-regulated and 82 were down-regulated. GO enrichment analysis and pathway enrichment analysis showed that the DEGs were closely related to the functional changes of trophoblast cells. Because of the enrichment of 7 DEGs and less Q value, PI3K/AKT pathway was prominent and attracted our attention. More importantly, we confirmed that knockdown of PVT1 obviously decreased AKT phosphorylation and decreased the expression of DEGs (GDPD3, ITGAV and ITGB8) while overexpression of PVT1 promoted the AKT phosphorylation and increased the expression of DEGs (GDPD3, ITGAV and ITGB8). PVT1 was primarily distributed in the nuclear compartment and also distributed in the cytoplasmic of HTR-8/Svneo cells.

CONCLUSIONS

This study provided the evidence that PVT1 played a vital role in trophoblast cells, and it is important for maintaining the normal physiological function of trophoblast cells. The PVT1 expression was lower in the GDM and PE placentas than the normal placentas, which might disrupt the function of trophoblast cells through PI3K/AKT pathway.

Effect of Chlorpyrifos on human extravillous-like trophoblast cells

An increased risk of pregnancy disorders has been reported in women and animal models exposed to organophosphate pesticides. However, less information is available on impacts to human placental function. Here, we addressed the impact of chlorpyrifos (CPF) on extravillous cytotrophoblasts (evCTB) employing HTR8/SVneo cells as an in vitro model. Cell proliferation, migration and invasion were not affected by CPF under conditions where cell viability was not compromised; however, we observed reduced expression of genes for vascular endothelial growth factor receptor 1, hypoxia-inducible factor 1-alpha, peroxisome proliferator activated receptor gamma, and the β-subunit of human chorionic gonadotropin. These results are the first effects reported by organophosphate pesticide in evCTB cells and show altered expression of several genes important for placental development that could serve as potential biomarkers for future research.

Traffic-related particulate matter exposure induces nephrotoxicity in vitro and in vivo

Traffic emission is responsible for most small-sized particulate matter (PM) air pollution in urban areas. Several recent studies have indicated that traffic-related PM may aggravate kidney disease. Furthermore, exposure to particulate air pollution may be related to the risk of chronic kidney disease (CKD). However, the underlying molecular mechanisms have not been adequately addressed. In the present study, we studied the mechanisms of renal damage that might be associated with exposure to PM. In a real world of whole-body exposure to traffic-related PM model for 3-6 months, PM in urban ambient air can affect kidney function and induce autophagy, endoplasmic reticulum (ER) stress and apoptosis in kidney tissues. Exposure to traffic-related diesel particulate matter (DPM) led to a reduction in cell viability in human kidney tubular epithelial cells HK-2. DPM increased mitochondrial reactive oxygen species (ROS) and decreased the mitochondrial membrane potential. Furthermore, DPM induced ER stress and activated the unfolded protein response (UPR) pathway. Eventually, DPM exposure induced caspase pathways and triggered apoptosis. In addition, DPM induced autophagy through the inhibition of the Akt/mTOR pathway. Autophagy inhibition resulted in significantly increased cytotoxicity and apoptosis. These findings suggest that air pollution in urban areas may cause nephrotoxicity and autophagy as a protective role in PM-induced cytotoxicity.