Early life exposure to di(2-ethylhexyl)phthalate causes age-related declines associated with insulin/IGF-1-like signaling pathway and SKN-1 in Caenorhabditis elegans

Di-(2-ethylhexyl) phthalate exposure induces premature testicular senescence by disrupting mitochondrial respiratory chain through STAT5B-mitoSTAT3 in Leydig cell

Di-(2-ethylhexyl) phthalate (DEHP), a prevalent plasticizer, is known to have endocrine-disrupting effects on males and cause reproductive toxicity. There were causal effects of DEHP on testosterone levels in the real world by Mendelian randomization analysis. Exposure to DEHP during the preadult stage might lead to premature testicular senescence, but the mechanisms responsible for this have yet to be determined. In this study, we administered DEHP (300 mg/kg/day) to male C57BL/6 mice from postnatal days 21 to 49. The mice were kept for 6 months without DEHP. RNA sequencing was conducted on testicular tissue at PNM6. The results indicated that DEHP hindered testicular development, lowered serum testosterone levels in male mice, and induced premature testicular senescence. TM3 Leydig cells were exposed to 300 μM of mono(2-ethylhexyl) phthalate (MEHP), the bioactive metabolite of DEHP, for 72 h. The results also found that DEHP/MEHP induced senescence in vivo and in vitro. The mitochondrial respiratory chain was disrupted in Leydig cells. The expression and stability of STAT5B were elevated by MEHP treatment in TM3 cells. Furthermore, p-ERK1/2 was significantly decreased by STAT5B, and mitochondria-STAT3 (p-STAT3 ser727) was significantly decreased due to the decrease of p-ERK1/2. Additionally, the senescence level of TM3 cells was decreased and treated with 5 mM NAC for 1 h after MEHP treatment. In conclusion, these findings provided a novel mechanistic understanding of Leydig cells by disrupting the mitochondrial respiratory chain through STAT5B-mitoSTAT3.

Polystyrene nanoparticles strengthen high glucose toxicity associated with alteration in insulin signaling pathway in C. elegans

Using Caenorhabditis elegans as animal model, we investigated the effect of exposure to polystyrene nanoparticles (PS-NPs) in the range of μg/L on high glucose toxicity induction. With lifespan and locomotion behavior as endpoints, we observed that PS-NP (10 and 100 μg/L) enhanced toxicity in 50 mM glucose treated animals. In insulin signaling pathway, expressions of genes encoding insulin receptor (daf-2), kinases (age-1 and akt-1/2), and insulin peptides (ins-9, ins-6, and daf-28) were increased, and expressions of daf-16 and its target of sod-3 were decreased in high glucose treated nematodes followed by PS-NP exposure. Toxicity enhancement in high glucose treated nematodes by PS-NP exposure was inhibited by RNAi of daf-2, age-1, akt-2, akt-1, and 3 insulin peptides genes, but increased by RNAi of daf-16 and sod-3. The resistance of animals with RNAi of daf-2 to toxicity in high glucose treated nematodes followed by PS-NP exposure could be suppressed by RNAi of daf-16. Moreover, in high glucose treated animals followed by PS-NP exposure, daf-2 expression was inhibited by RNAi of ins-6, ins-9, and daf-28. Our data demonstrated the risk of PS-NP exposure in enhancing the high glucose toxicity. More importantly, alteration in expression of genes in insulin signaling pathway was associated with the toxicity enhancement in high glucose treated nematodes followed by PS-NP exposure.

Exposure to 6-PPD Quinone at Environmentally Relevant Concentrations Inhibits Both Lifespan and Healthspan in C. elegans

N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine (6-PPD), one of the most common additives used in rubber, enters the environment due to significant emissions of tire wear particles. 6-PPD quinone (6-PPDQ) is an important derivative of 6-PPD after ozonization. With concentrations ranging from nanograms per liter to μg/L, 6-PPDQ has so far been identified in a series of water samples. Acute lethality of 6-PPDQ in coho salmon (LC50 < 1 μg/L) was lower than environmental concentrations of 6-PPDQ, highlighting the environment exposure risks of 6-PPDQ. It is becoming increasingly necessary to investigate the potential toxicity of 6-PPDQ at environmental concentrations. Here, we examined the effect of 6-PPDQ exposure on lifespan and healthspan and the underlying mechanism in Caenorhabditis elegans. Exposure to 6-PPDQ (1 and 10 μg/L) shortened the lifespan. Meanwhile, during the aging process, 6-PPDQ (0.1-10 μg/L) could decrease both pumping rate and locomotion behavior, suggesting the 6-PPDQ toxicity on healthspan. For the underlying molecular mechanism, the dysregulation in the insulin signaling pathway was linked to toxicity of 6-PPDQ on lifespan and healthspan. In the insulin signaling pathway, DAF-2 restricted the function of DAF-16 to activate downstream targets (SOD-3 and HSP-6), which in turn controlled the toxicity of 6-PPDQ on lifespan and healthspan. Additionally, in response to 6-PPDQ toxicity, insulin peptides (INS-6, INS-7, and DAF-28) could activate the corresponding receptor DAF-2. Therefore, exposure to 6-PPDQ at environmentally relevant concentrations potentially causes damage to both lifespan and healthspan by activating insulin signaling in organisms.

Di(2-ethylhexyl) phthalate induces reproductive toxicity and transgenerational reproductive aging in Caenorhabditis elegans

With the large-scale production and use of plastic products, the global plastic pollution problem is becoming more and more serious. The plasticizer di (2-ethylhexyl) phthalate (DEHP), which is widely used in the production of plastics, has caused great concern for the health of the population. Exposure of organisms to DEHP can cause a variety of health damage, of which reproductive system damage is an important part. At present, there are still few studies on DEHP in reproductive aging, and it is of great significance to explore the role of DEHP in promoting reproductive aging and its underlying mechanism. In this study, the model organism Caenorhabditis elegans (C. elegans) was used to preliminarily explore the mechanism of DEHP-induced female reproductive senescence. The results showed that DEHP reduced the number of offspring and gonad area of C. elegans, resulting in shortened reproductive and life span, abnormal phenotypes in somatic gonad structure including the Emo phenotype, the BOW phenotype, a twisted gonad arm, and atrophied oocytes. Biochemical studies showed that DEHP promoted oxidative stress and autophagy in C. elegans. Further, we found the decreased number of offspring, malformed somatic gonad structure, oxidative damage and autophagy induced by DEHP in parental worms can be inheritance to the not directly exposed offspring.

Tangeretin Supplementation Mitigates the Aging Toxicity Induced by Dietary Benzo[a]pyrene Exposure with Aberrant Proteostasis and Heat Shock Responses in Caenorhabditis elegans

Benzo[a]pyrene (BaP) is a common food contaminant that can impair organismal aging. Tangeretin (TAN) may mitigate aging toxicities as a dietary supplement. This study used Caenorhabditis elegans to investigate the effects of chronic exposure to BaP on aging and to determine whether TAN supplementation could alleviate BaP-induced toxicity. Early life exposure to BaP (10 μM) significantly inhibited growth by 5%, and exposure to 0.1 to 10 μM BaP impaired C. elegans motility, resulting in a 3.4-6.5% reduction in motility. Chronic exposure to BaP (10 μM) age-dependently aggravated aberrant protein aggregation (7% increase) and shortened the median lifespan of the worms from 20 to 16 days. In addition, BaP worsened the age-dependent decline in motility and pharyngeal pumping, as well as the accumulation of reactive oxygen species. Furthermore, exposure to BaP resulted in significantly higher relative transcript levels of approximately 1.8-2.0-fold for the hsp-16.1, hsp-16.2, hsp-16.49, and hsp-70 genes. Stressed worms exposed to BaP exhibited significantly lower survival under heat stress. Dietary TAN supplementation alleviated the BaP-induced decline in motility, pumping, and poly-Q accumulation and restored heat shock proteins' transcript levels. Our findings suggest that chronic BaP exposure adversely affects aging and that TAN exposure mitigates the BaP-induced aging toxicity.

Microbial colonization of microplastics in wastewater accelerates the aging process associated with oxidative stress and the insulin/IGF1 signaling pathway

Although polystyrene (PS)-induced toxicity in organisms has been documented, adverse effects on lifespan and molecular mechanisms underlying microbial colonization of PS remain elusive. Herein, physicochemical properties of biofilm-developed PS (B-PS) incubated in wastewater were altered compared with virgin PS (V-PS). Bacterial community adherence to the B-PS surface were also impacted. Acute exposure to V-PS (100 μg/L) and B-PS (10 μg/L) significantly altered the mean lifespan and lipofuscin accumulation of Caenorhabditis elegans, suggesting that B-PS exposure at environmentally relevant concentrations could more severely accelerate the aging process than V-PS. Generation of ROS, gst-4::GFP expression, and oxidative stress-related gene expression were significantly altered following B-PS exposure. Moreover, B-PS exposure increased the nucleus-cytoplasm translocation of DAF-16 and altered the expression of genes encoding the insulin/IGF1 signaling (IIS) pathway. Compared with wild-type nematodes, the daf-16 mutation markedly enhanced lipofuscin accumulation and reduced mean lifespan, whereas daf-2, age-1, pdk-1, and akt-1 mutants could recover lipofuscin accumulation and mean lifespan. Accordingly, B-PS exposure accelerated the aging process associated with oxidative stress and the IIS pathway, and the DAF-2-AGE-1-PDK-1-AKT-1-DAF-16 signaling cascade may play a critical role in regulating the lifespan of C. elegans. This study provides new insights into the potential risks associated with microbial colonization of microplastics.

Chronic exposure to di(2-ethylhexyl) phthalate (DEHP) weakens innate immunity and leads to immunosenescence in C. elegans

Di(2-ethylhexyl) phthalate (DEHP), a widespread contaminant, has numerous adverse impacts on human health and ecosystems. Chronic DEHP exposure has been found to accelerate aging; however, its potential threat to age-dependent innate immune decline remains unknown. This study aims to evaluate the effects of chronic DEHP exposure on innate immunosenescence in Caenorhabditis elegans. We show that the length of the exposure period significantly impacts DEHP-induced age-related declines, which is linked to immunosenescence and oxidative stress. We found that the DEHP-caused immunosenescence is accompanied with downregulation of an antimicrobial gene lys-7 as well as an enhancement of the nuclear translocation of HLH-30, an orthologue of mammalian transcription factor EB (TFEB). Moreover, DEHP exposure increases the expression of riok-1, a human RIO kinase homolog, which is associated with DEHP-induced HLH-30/TFEB translocation. Our findings suggest that early-life and chronic exposure to DEHP, mostly due to parent compound rather than its metabolite mono(2-ethylhexyl) phthalate (MEHP), may weaken the innate immunity in C. elegans and may enhance susceptibility to infections or promote immunosenescence in aged populations.

Nanoplastic exposure in soil compromises the energy budget of the soil nematode C. elegans and decreases reproductive fitness

Environmental nanoplastics (NPs) can accumulate in soils, posing a potential risk to soil ecosystems. However, the ecotoxicity of NPs for soil organisms has received little research attention. This study investigated whether NP exposure in soil leads to reproductive decline in the soil nematode Caenorhabditis elegans and sought to determine the mechanisms by which it may occur. Wild-type N2 C. elegans L1 larvae were exposed to various concentrations of nano-sized polystyrene (100 nm) in soil (0, 1, 10, 100, and 1000 mg/kg dry weight) for 96 h. We show that nano-sized polystyrene (100 nm) labeled with red fluorescence significantly accumulated in the intestine of C. elegans in a dose-dependent fashion via soil exposure (8%-47% increase). In addition, NP soil exposure led to 7%-33% decline in the number of eggs in utero and 2.6%-4.4% decline in the egg hatching percentage. We also find that the number of germ cell corpses (31%-55% increase) and the mRNA levels of germline apoptosis marker gene ced-3 (14%-31% increase) were significantly higher with greater NP soil exposure (10, 100, and 1000 mg/kg), while intracellular ATP levels were significantly reduced. Finally, the DEBtox model, which is based on the dynamic energy budget theory, was applied to show that the increased reproductive costs for C. elegans caused by NPs in soil are associated with energy depletion and reproductive decline. The threshold value (4.18 × 10^-6 mg/kg) for the energy budget also highlighted the potential high reproductive risk posed by NPs in terrestrial ecosystems. Our study provides new insights into how soil organisms interact with NPs in soil ecosystems.

Lipid metabolism and ageing in Caenorhabditis elegans: a complex interplay

Life expectancy in Western countries is increasing, with concomitant rise in ageing-related pathologies, including Parkinson's and Alzheimer's disease, as well as other neurodegenerative diseases. Consequently, the medical, psychological and economic burden to society is increasing. Thus, understanding the cellular and molecular mechanisms underlying the association of ageing with elevated vulnerability to disease is crucial towards promoting quality of life in old age. Caenorhabditis elegans has emerged as a versatile model to study ageing, due to its simplicity, fast life cycle, and the availability of a wide range of biological tools to target specific genes and cells. Indeed, recent studies in C. elegans have revealed that lipid metabolism plays a key role in controlling longevity by impinging on a plethora of molecular pathways and cell types. Here, we summarise findings relevant to the interplay between lipid metabolism and ageing in C. elegans, and discuss the implications for the pathogenesis of age-related disorders in humans.

Chronic di(2-ethylhexyl) phthalate exposure leads to dopaminergic neuron degeneration through mitochondrial dysfunction in C. elegans

The plasticizer di(2-ethylhexyl) phthalate (DEHP) is frequently detected in the environment due to the abundance of its use. These levels might be hazardous to human health and ecosystems. Phthalates have been associated with neurological disorders, yet whether chronic DEHP exposure plays a role in Parkinson's disease (PD) or its underlying mechanisms is unknown. We investigated the effects of chronic DEHP exposure less than an environmentally-relevant dose on PD hallmarks, using Caenorhabditis elegans as a model. We show that developmental stage and exposure timing influence DEHP-induced dopaminergic neuron degeneration. In addition, in response to chronic DEHP exposure at 5 mg/L, mitochondrial fragmentation became significantly elevated, reactive oxygen species (ROS) levels increased, and ATP levels decreased, suggesting that mitochondrial dysfunction occurs. Furthermore, the data show that mitochondrial complex I (nuo-1 and gas-1) and complex II (mev-1) are involved in DEHP-induced dopaminergic neuron toxicity. These results suggest that chronic exposure to DEHP at levels less than an environmentally-relevant dose causes dopaminergic neuron degeneration through mitochondrial dysfunction involving mitochondrial complex I and II. Considering the high level of genetic conservation between C. elegans and mammals, chronic DEHP exposure might elevate the risk of developing PD in humans.

Chronic exposure to environmentally relevant levels of di(2-ethylhexyl) phthalate (DEHP) disrupts lipid metabolism associated with SBP-1/SREBP and ER stress in C. elegans

DEHP is commonly found in the environment, biota, food, and humans, raising significant health concerns. Whether developmental stage and exposure duration modify the obesogenic effects of DEHP is unclear, especially the underlying mechanisms by which chronic exposure to DEHP as well as its metabolites remain largely unknown. This study investigated the obesogenic effects of chronic DEHP exposure, with levels below environmentally-relevant amounts and provide the mechanism in Caenorhabditis elegans. We show that early-life DEHP exposure resulted in an increased lipid and triglyceride (TG) accumulation mainly attributed to DEHP itself, not its metabolite mono-2-ethylhexyl phthalate (MEHP). In addition, developmental stage and exposure timing influence DEHP-induced TG accumulation and chronic DEHP exposure resulted in the most significant effect. Analysis of fatty acid composition shows that chronic DEHP exposure altered fatty acid composition and TG, resulting in an increased ω-6/ω-3 ratio. The increased TG content by chronic DEHP exposure required lipogenic genes fat-6, fat-7, pod-2, fasn-1, and sbp-1. Moreover, chronic DEHP exposure induced XBP-1-mediated endoplasmic reticulum (ER) stress which might lead to up-regulation of sbp-1. This study suggests the possible involvement of ER stress and SBP-1/SREBP-mediated lipogenesis in chronic DEHP-induced obesogenic effects. Results from this study implies that chronic exposure to DEHP disrupts lipid metabolism, which is likely conserved across species due to evolutionary conservation of molecular mechanisms, raising concerns in ecological and human health.

Competition-Induced Binding Spherical Nucleic AcidFluorescence Amplifier for the Detection of Di (2-ethylhexyl) Phthalate in the Aquatic Environment

Di-2-ethylhexyl phthalate (DEHP) is a toxic plasticizer and androgen antagonist. Its accumulation in water exceeds national drinking water standards and it must be continuously and effectively regulated. Currently, methods used to detect DEHP are still unsatisfactory because they usually have limited detection sensitivity and require complex operating procedures. A competition-induced fluorescence detection method was developed for the selective detection of DEHP in an aquatic environment. An aptamer with walking function was used as the recognition element for DEHP, and its quantification was induced by competition to change the fluorescence signal. The detection range was 0.01~100 µg/L, and the detection limit was 1.008 μg/L. This high-sensitivity DEHP detection capability and simplified process facilitates real-time fields and other monitoring tasks.

UV-filter octyl methoxycinnamate causes reproductive toxicity associated with germline apoptosis and vitellogenin decrease in Caenorhabditis elegans

Octyl methoxycinnamate (OMC) is a common UV filter found in personal care products such as sunscreen and cosmetics. However, OMC's presence in wastewater has raised concerns that it could potentially pollute aquatic ecosystems because of its limited biodegradability and its estrogenic disrupting properties. In this study, we investigated the environmental toxicity of OMC and its potential biomarkers using the nematode Caenorhabditis elegans. Our results showed that body length, eggs in utero, and total brood size decreased with increasing dose (experimental concentrations = 0, 1, 5, 10, 100, 500 μM for body length and eggs in utero, and 0, 5, 10 μM for total brood size) in C. elegans after L1 larval stage (the first larval stage for 0 - 12 hours post-hatching) larval stage exposure to OMC. The minimum effective concentrations were 1, 5, and 10 μM, respectively. Modeling results demonstrated that the threshold concentration of OMC inducing 10% inhibited eggs in utero was 0.33 μM (95.11 μg/L). Furthermore, germline apoptosis was induced in 10 μM OMC-treated worms (experimental concentrations = 0, 5, 10 μM). Decreased mRNA levels of vitellogenin-related genes (vit-2 and vit-6) and increased mRNA levels of apoptosis-related genes (egl-1 and ced-3) were observed in 10 μM OMC-treated C. elegans (experimental concentrations = 0, 10 μM), suggesting that reproductive toxicity was associated with decreased vitellogenin levels and germline apoptosis. In summary, our study shows that OMC is reproductively toxic and leads to reduced egg formation and decreased brood size in C. elegans by reducing vitellogenin levels and promoting germline apoptosis.

Tris(1,3-dichloro-2-propyl) phosphate reduces longevity through a specific microRNA-mediated DAF-16/FoxO in an unconventional insulin/insulin-like growth factor‑1 signaling pathway

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) has received concerns due to its frequent detection in environmental media and biological samples. Our previous study has indicated TDCPP reduced the lifespan of Caenorhabditis elegans (C. elegans) by triggering an unconventional insulin/insulin-like growth factor signaling (IIS) pathway. This study continued to investigate the possible deleterious effects of TDCPP relating to longevity regulation signal pathways and biological processes. Specifically, this study uniquely performed small RNA transcriptome sequencing (RNA-seq), focusing on the underlying mechanisms of TDCPP-reduced the longevity of C. elegans in-depth in microRNAs (miRNAs). Based on Small RNA-seq results and transcript levels of mRNA involved in the unconventional IIS pathway, a small interaction network of miRNAs-mRNAs following TDCPP exposure in C. elegans was preliminarily established. Among them, up-regulated miR-48 and miR-84 (let-7 family members) silence the mRNA of daf-16 (the crucial member of the FoxO family and pivotal regulator in longevity) via post-transcription and translation dampening abilities, further inhibit its downstream target metallothionein-1 (mtl-1), and ultimately contributed to the reduction of nematode longevity and locomotion behaviors. Meanwhile, the high binding affinities of TDCPP with miRNAs cel-miR-48-5p and cel-miR-84-5p strongly support their participation in the regulation of nematode mobility and longevity. These findings provide a comprehensive analysis of TDCPP-reduced longevity from the perspective of miRNAs.

Tangeretin promotes lifespan associated with insulin/insulin-like growth factor-1 signaling pathway and heat resistance in Caenorhabditis elegans

Tangeretin is a polymethoxylated flavonoid naturally occurred in citrus fruits with many pharmacological activities, such as anti-inflammatory, antiproliferative, and neuroprotective properties. A previous study reported that tangeretin-enriched orange extract could prolong the lifespan in Caenorhabditis elegans. However, the antiaging effect of tangeretin remains uncertain. In this study, we used the model organism C. elegans to conduct a lifespan test, observed the aging-related functional changes of nematodes, the fluorescence changes of stress-related proteins (DAF-16 and HSP-16.2) and its response to stress assay, and monitored the effect of tangeretin on the mRNA expression levels. The results showed that tangeretin supplementation (30 and 100 μM) extended the mean lifespan, slowed aging-related functional declines, and increased the resistance against heat-shock stress. Furthermore, tangeretin upregulated the mRNA expression of daf-16, hsp-16.2, and hsp-16.49, promoted the nuclear localization of DAF-16, and enhanced the fluorescence intensity of HSP-16.2, while it had no effect on the lifespan of daf-2, age-1, and daf-16 mutants. The current findings suggest that tangeretin can significantly extend the lifespan and enhance heat stress tolerance in an insulin/insulin-like growth factor signaling dependent manner.

The Mechanism of Stem Cell Aging

Stem cells have self-renewal ability and multi-directional differentiation potential. They have tissue repair capabilities and are essential for maintaining the tissue homeostasis. The depletion of stem cells is closely related to the occurrence of body aging and aging-related diseases. Therefore, revealing the molecular mechanisms of stem cell aging will set new directions for the therapeutic application of stem cells, the study of aging mechanisms, and the prevention and treatment of aging-related diseases. This review comprehensively describes the molecular mechanisms related to stem cell aging and provides the basis for further investigations aimed at developing new anti-stem cell aging strategies and promoting the clinical application of stem cells.

siRNA@superparamagnetic iron oxide nanoparticles attenuate physiological toxicity of DEHP by suppressing autophagy pathway activities in Caenorhabditis elegans

Bis(2-ethylhexyl)ortho-phthalate (DEHP) is a widely used plasticizer in polyvinyl chloride materials. Considering its widespread application, it has become a major environmental pollutant and can cause endocrine, reproductive system, and gastrointestinal disorders. Herein we aimed to elucidate the mechanisms via which DEHP causes cytotoxicity in Caenorhabditis elegans and assess whether siRNA@superparamagnetic iron oxide nanoparticles (SPIONs) can attenuate this effect. On exposing C. elegans to 10 μM DEHP, its physiological functions and gene expression levels were markedly affected. RNA-seq and Kyoto Encyclopedia of Genes and Genomes pathway analyses indicated that DEHP exposure significantly activated the autophagy-animal signal transduction pathway in the somatic cells of C. elegans. Subsequently, the surface of SPIONs was loaded with siRNAs and transfected into C. elegans. Transmission electron microscopy showed that SPIONs could smoothly enter the somatic cells of C. elegans. Further, qPCR showed that the expression levels of autophagy pathway-related genes, namely Atg-2, Epg-9, Atg-18, Bec-1, and Atg-16.2, in the siRNA@SPION intervention group were significantly lower than those in the control group. Biochemical and physiological test results suggested that siRNA@SPION complexes attenuated DEHP-induced physiological toxicity and oxidative stress damage in C. elegans. Collectively, our findings indicated that DEHP markedly affects the physiological activity of C. elegans, induces changes in gene expression levels, and activates the autophagy signal transduction pathway and that siRNA@SPION complexes suppress such toxic effects by silencing the expression of genes involved in the autophagy signal transduction pathway.

Chronic exposure of zearalenone inhibits antioxidant defense and results in aging-related defects associated with DAF-16/FOXO in Caenorhabditis elegans

Zearalenone (ZEN), a mycotoxin with endocrine disruptive activity and oxidative stress generating ability, has been a worldwide environmental concern for its prevalence and persistency. However, the long-term effect of ZEN on aging process is not fully elucidated. Thus, the present study applied the Caenorhabditis elegans model to investigate the aging-related toxic effect and possible underlying mechanisms under prolonged and chronic ZEN exposure. Our results showed that locomotive behaviors significantly decreased in ZEN (0.3, 1.25, 5, 10, 50 μM) treated C. elegans. In addition, lifespan and aging markers including pharyngeal pumping and lipofuscin were also adversely affected by ZEN (50 μM). Furthermore, ZEN (50 μM) increased ROS level and downregulated antioxidant genes resulted from inhibition of nuclear DAF-16 translocation in aged C. elegans, which was further confirmed by more significant aging-related defects observed in ZEN treated daf-16 mutant. In conclusion, our findings suggest that the aging process and aging-related decline were induced by long-term exposure of ZEN in C. elegans, which is associated with oxidative stress, inhibition of antioxidant defense, and transcription factor DAF-16/FOXO.

Early-life chronic di(2-ethylhexyl)phthalate exposure worsens age-related long-term associative memory decline associated with insulin/IGF-1 signaling and CRH-1/CREB in Caenorhabditis elegans

The ubiquitous contamination of di(2-ethylhexyl)phthalate (DEHP) in the environment, biota, and food poses potential ecological and human health risks. DEHP exposure can adversely affect learning and memory, yet the underlying mechanisms remain unclear. In this study, Caenorhabditis elegans was used to investigate the effect of early-life DEHP exposure on age-related long-term associative memory (LTAM) decline, as well as the associations with the cAMP-responsive element-binding protein (CREB) transcription factor and insulin/IGF-1 signaling (IIS). We showed that early-life exposure to DEHP reduced LTAM in wild-type worms at day-0 adulthood. Chronic exposure to DEHP from the L1 stage to day-5 adulthood worsened the age-dependent decline of LTAM. Moreover, the effect of DEHP on age-related LTAM requires CRH-1, a homolog of CREB. Mutations in daf-2, the sole receptor of C. elegans IIS, ameliorated the inhibition of LTAM by DEHP, and the effect depended on daf-16. In addition, daf-2 mutation restored the CRH-1 level in DEHP-exposed worms, and the effect required daf-16. Our study suggests that early-life chronic exposure to DEHP worsens age-related LTAM decline and the effect is associated with CRH-1 and IIS in C. elegans. The evolutionary conservation of IIS and CREB implies possible adverse effects by DEHP across species.

Analysis of the impact of three phthalates on the freshwater gastropod Physella acuta at the transcriptional level

Plastic pollution is one of the leading environmental problems. Phthalates are widely used plastic additives released into the environment. Although the effects of phthalates on vertebrates have been extensively studied, there is a knowledge gap regarding their effects on invertebrates. This work analyzes the impact of three phthalates, diethyl phthalate (DEP), benzyl butyl phthalate (BBP), and bis-(2-ethylhexyl) phthalate (DEHP), on the gastropod Physella acuta at the molecular level to establish the putative pathways involved in its response to them. By real-time PCR, we obtained the expression profile of 30 genes in animals exposed for 1 week to 0.1, 10, and 1000 μg/L of each phthalate. The genes cover DNA repair, detoxification, apoptosis, oxidative and stress responses, immunity, energy reserves, and lipid transport. The results show that while DEP and DEHP did not alter the mRNA levels, BBP modulated almost all the analyzed genes. It can be concluded that the impact of BBP is extensive at the molecular level. However, it cannot be dismissed that the increase in transcriptional activity is a general response due to this compound's well-known role as an endocrine disruptor. Additional research is needed to elucidate the differences observed in the impact of these compounds on the gastropod P. acuta.

Early-life and chronic exposure to di(2-ethylhexyl) phthalate enhances amyloid-β toxicity associated with an autophagy-related gene in Caenorhabditis elegans Alzheimer's disease models

The widespread use of di(2-ethylhexyl) phthalate (DEHP) has resulted in its ubiquitous presence in the environment, which has led to serious health concerns. One of these concerns is its possible link to Alzheimer's disease (AD), which is the most common neurodegenerative disease in aged individuals. This study investigated whether early-life and chronic exposure to DEHP affects AD via the toxicity of amyloid-β (Aβ), which has been implicated in the pathogenesis of AD, using Caenorhabditis elegans AD models (strains CL4176 and CL2006). We show that early-life DEHP exposure increased Aβ toxicity in C. elegans strains CL4176 and CL2006. Early-life and chronic exposure to DEHP also significantly increased intracellular ROS levels and Aβ deposition in aged CL2006 nematodes. Moreover, it was found that DEHP-induced Aβ toxicity does not require transcription factors DAF-16 or SKN-1, while early-life and chronic exposure to DEHP significantly increased the accumulation of lysosome-related organelles and the mRNA levels of the autophagy-related gene bec-1 in aged CL2006 nematodes. Our findings suggest that early-life and chronic exposure to DEHP enhances Aβ toxicity, which may be associated with the autophagy-lysosomal degradation pathway in C. elegans.

Tris(1,3-dichloro-2-propyl)phosphate Reduces the Lifespan via Activation of an Unconventional Insulin/Insulin-Like Growth Factor-1 Signaling Pathway

Tris(1,3-dichloro-2-propyl)phosphate (TDCPP) is an environmental contaminant that has attracted increasing concern due to its presence in environmental media and biological samples. Our previous study demonstrated that exposure to TDCPP reduced the lifespan of Caenorhabditis elegans, but the mechanisms, including the relevant signaling pathways, are unclear. The current study found that TDCPP exposure triggers an unconventional insulin/insulin-like growth factor signaling (IIS) pathway, not by disrupting the insulin-like growth factor-1 receptor DAF-2/IGF1R but by inhibiting the downstream tumor-suppressor factor DAF-18/PTEN. This inhibition reduces PI(3,4,5)P₃ (PIP₃) dephosphorylation, causing buildup that increases the activation of the Akt/Protein Kinase B (PKB) family of serine/threonine kinases. This activation induces DAF-16/FoxO phosphorylation and promotes the sequestration of DAF-16/FoxO in the cytoplasm, reducing the lifespan of nematodes. Our results have important diagnostic and therapeutic implications for controlling TDCPP-related diseases, especially those originating with IIS pathway components.

[Effects of Shoutai pills on immune function and oxidative stress in pregnant rats with di(2-ethylhexyl) phthalate exposure]

OBJECTIVE

To investigate the effects of Shoutai pills (a traditional Chinese medicinal preparation) on immune functions and oxidative stress in pregnant rats exposed to di(2-ethylhexyl) phthalate (DEHP).

METHODS

Thirty-six mature female SD rats were randomly divided into 3 groups (n=12). After pregnancy was confirmed, the rats were given 10 mL/kg corn oil +10 mL/kg saline (control group), 500 mg/kg DEHP+10 mL/kg saline (model group), and 500 mg/kg DEHP+10 mL/kg Shoutai pills (treatment group). At 19 days of gestation, the rats were sacrificed and the fetal rats were weighed and the numbers of live and stillborn fetal rats were recorded. Serum levels of interleukin-6 (IL-6), interleukin-2 (IL-2), tumor necrosis factor-ɑ (TNF-ɑ), estradiol (E2) and progesterone (P) levels were detected. The appearance, color and quality of the placenta in each group were recorded, and the placental tissues were examined pathologically. The total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH- Px), catalase (CAT), reactive oxygen species (ROS) and malondialdehyde (MDA) in the placental tissues were measured.

RESULTS

Compared with the control group, the rats with DEHP exposure showed slow weight gain in the middle and late gestation period and significantly lower fetal weight (P < 0.05) with lowered serum levels of IL-2, IL-6 and TNF-ɑ, increased estradiol level (P < 0.05), decreased placental T-AOC, GSH-Px, SOD and CAT levels, and increased ROS and MDA levels (P < 0.01). Compared with the model group, the rats treated with Shoutai pills had significantly increased weight gain in mid and late pregnancy and greater fetal weight (P < 0.05) with significantly increased serum IL-2 and IL-6 levels, decreased estradiol level (P < 0.05), slightly increased TNF-ɑ expression (P> 0.05), increased placenta T-AOC, GSH- Px and CAT levels, decreased MDA level (P < 0.05), and slightly increased SOD and decreased ROS levels (P>0.05). No significant difference was found in progesterone levels among the groups (P>0.05). HE staining showed that the trophoblast in the placental tissue sponge in the model group was loose and irregular with numerous vacuoles. In the treatment group, the structure of the placenta remained intact with clearly visible labyrinth zone, sponge trophoblast and giant cell trophoblast, and the cell distribution in each layer was better than that in the model group.

CONCLUSIONS

Shoutai pills can regulate the immune function of DEHP-exposed pregnant rats possibly by antagonizing the estrogenlike effect of DEHP and regulating serum immune factors; Shoutai pills can also reduce placental tissue damage and improve pregnancy outcome by correcting DEHP-induced imbalance of oxidative stress in the placental tissues.

Selection of Aptamers Specific for DEHP Based on ssDNA Library Immobilized SELEX and Development of Electrochemical Impedance Spectroscopy Aptasensor

A selection of aptamers specific for di(2-ethylhexyl) phthalate (DEHP) and development of electrochemical impedance spectroscopy (EIS) aptasensor are described in this paper. The aptamers were selected from an immobilized ssDNA library using the systematic evolution of ligands by exponential enrichment (SELEX). The enrichment was monitored using real-time quantitative PCR (Q-PCR), and the aptamers were identified by high-throughput sequencing (HTS), gold nanoparticles (AuNPs) colorimetric assay, and localized surface plasmon resonance (LSPR). The EIS aptasensor was developed to detect DEHP in water samples. After eight rounds of enrichment, HTS, AuNPs colorimetric assay, and LSPR analysis indicated that four aptamers had higher binding activity, and aptamer 31 had the highest affinity (Kd = 2.26 ± 0.06 nM). The EIS aptasensor had a limit of detection (LOD) of 0.103 pg/mL with no cross-reactivity to DEHP analogs and a mean recovery of 76.07% to 141.32% for detection of DEHP in water samples. This aptamer is novel with the highest affinity and sensitivity.