Transcriptome analysis revealed the mechanism of the metabolic toxicity and susceptibility of di-(2-ethylhexyl)phthalate on adolescent male ICR mice with type 2 diabetes mellitus

Association of Ultraprocessed Food Consumption with Risk of Cardiovascular Disease Among Individuals with Type 2 Diabetes: Findings from the UK Biobank

SCOPE

Among patients with diabetes, who have modified nutritional behavior and a higher risk of cardiovascular disease (CVD), the influence of ultraprocessed foods (UPFs) on CVD remains unknown. The study aims to evaluate the association between UPF intake and the risk of CVD among individuals with type 2 diabetes (T2D) and further examine the potential biological pathways linking the association.

METHODS AND RESULTS

This study includes 5405 participants with T2D who provided at least one 24-h dietary recall from the UK Biobank study. In the fully adjusted models, a 10% increase in the proportion of UPFs is associated with higher hazards of overall CVD (hazard ratio [HR]: 1.10; 95% confidence interval [CI]: 1.04, 1.15), coronary heart disease (HR: 1.10; 95% CI: 1.04, 1.16), heart failure (HR: 1.14; 95% CI: 1.05, 1.25), but not stroke (HR: 1.01; 95% CI: 0.90, 1.12). Cystatin C, high-density lipoprotein cholesterol (HDL-C), apolipoprotein A, C-reactive protein, and body mass index collectively explain 26.9% (12.8%, 48.5%) of the association between UPF intake and the risk of overall CVD.

CONCLUSION

Higher UPF intakes are associated with increased hazards of CVD among individuals with T2D, and the association is partly mediated through worsening biomarkers of renal function, lipid metabolism, inflammation, and body weight.

Transcriptomics Reveals the Mechanism of Rosa roxburghii Tratt Ellagitannin in Improving Hepatic Lipid Metabolism Disorder in db/db Mice

A complex metabolic disorder, type 2 diabetes, was investigated to explore the impact of ellagitannin, derived from Rosa roxburghii Tratt (RTT), on liver lipid metabolism disorders in db/db mice. The findings demonstrated that both RTT ellagitannin (C1) and RTT ellagic acid (C4) considerably decelerated body mass gain in db/db mice, significantly decreased fasting blood glucose (FBG) levels, and mitigated the aggregation of hepatic lipid droplets. At LDL-C levels, C1 performed substantially better than the C4 group, exhibiting no significant difference compared to the P (positive control) group. An RNA-seq analysis further disclosed that 1245 differentially expressed genes were identified in the livers of experimental mice following the C1 intervention. The GO and KEGG enrichment analysis revealed that, under ellagitannin intervention, numerous differentially expressed genes were significantly enriched in fatty acid metabolic processes, the PPAR signaling pathway, fatty acid degradation, fatty acid synthesis, and other lipid metabolism-related pathways. The qRT-PCR and Western blot analysis results indicated that RTT ellagitannin notably upregulated the gene and protein expression levels of peroxisome proliferator-activated receptor alpha (PPARα) and peroxisome proliferator-activated receptor gamma (PPARγ). In contrast, it downregulated the gene and protein expression levels of sterol regulatory element-binding protein (SREBP), recombinant fatty acid synthase (FASN), and acetyl-CoA carboxylase (ACC). Therefore, RTT ellagitannin can activate the PPAR signaling pathway, inhibit fatty acid uptake and de novo synthesis, and ameliorate hepatic lipid metabolism disorder in db/db mice, thus potentially aiding in maintaining lipid homeostasis in type 2 diabetes.

Food contaminants and potential risk of diabetes development: A narrative review

The number of people diagnosed with diabetes continues to increase, especially among younger populations. Apart from genetic predisposition and lifestyle, there is increasing scientific and public concern that environmental agents may also contribute to diabetes. Food contamination by chemical substances that originate from packaging materials, or are the result of chemical reactions during food processing, is generally recognized as a worldwide problem with potential health hazards. Phthalates, bisphenol A (BPA) and acrylamide (AA) have been the focus of attention in recent years, due to the numerous adverse health effects associated with their exposure. This paper summarizes the available data about the association between phthalates, BPA and AA exposure and diabetes. Although their mechanism of action has not been fully clarified, in vitro, in vivo and epidemiological studies have made significant progress toward identifying the potential roles of phthalates, BPA and AA in diabetes development and progression. These chemicals interfere with multiple signaling pathways involved in glucose and lipid homeostasis and can aggravate the symptoms of diabetes. Especially concerning are the effects of exposure during early stages and the gestational period. Well-designed prospective studies are needed in order to better establish prevention strategies against the harmful effects of these food contaminants.

The Relationship between Phthalates and Diabetes: A Review

Since the beginning of their production, in the 1930s, phthalates have been widely used in the plastics industry to provide durability and elasticity to polymers that would otherwise be rigid, or as solvents in hygiene and cosmetic products. Taking into account their wide range of applications, it is easy to understand why their use has been increasing over the years, making them ubiquitous in the environment. This way, all living organisms are easily exposed to these compounds, which have already been classified as endocrine disruptor compounds (EDC), affecting hormone homeostasis. Along with this increase in phthalate-containing products, the incidence of several metabolic diseases has also been rising, namely diabetes. That said, and considering that factors such as obesity and genetics are not enough to explain this substantial increase, it has been proposed that the exposure to environmental contaminants may also be a risk factor for diabetes. Thus, the aim of this work is to review whether there is an association between the exposure to phthalates and the development of the several forms of diabetes mellitus, during pregnancy, childhood, and adulthood.

Cumulative Risk Evaluation of Phthalates Under TSCA

The U.S. Environmental Protection Agency (EPA) is currently conducting separate Toxic Substances Control Act (TSCA) risk evaluations for seven phthalates: dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), diisobutyl phthalate (DIBP), dicyclohexyl phthalate (DCHP), di-isodecyl phthalate (DIDP), and diisononyl phthalate (DINP). Phthalates are highly abundant plastic additives used primarily to soften materials and make them flexible, and biomonitoring shows widespread human exposure to a mixture of phthalates. Evidence supports biological additivity of phthalate mixture exposures, including the enhancement of toxicity affecting common biological targets. Risk estimates based on individual phthalate exposure may not be protective of public health. Thus, a cumulative risk approach is warranted. While EPA initially did not signal that it would incorporate cumulative risk assessment (CRA) as part of its current risk evaluation for the seven phthalates, the agency recently announced that it is reconsidering if CRA for phthalates would be appropriate. Based on our review of existing chemical mixtures risk assessment guidance, current TSCA scoping documents for the seven phthalates, and pertinent peer-reviewed literature, we delineate a CRA approach that EPA can easily implement for phthalates. The strategy for using CRA to inform TSCA risk evaluation for existing chemicals is based upon integrative physiology and a common adverse health outcome algorithm for identifying and grouping relevant nonchemical and chemical stressors. We recommend adjustments for how hazard indices (HIs) or margins of exposure (MOEs) based on CRA are interpreted for determining "unreasonable risk" under TSCA.

Consequences of in vitro benzyl butyl phthalate exposure for blubber gene expression and insulin-induced Akt activation in juvenile grey seals

Plastic and plasticiser pollution of marine environments is a growing concern. Although phthalates, one group of plasticisers, are rapidly metabolised by mammals, they are found ubiquitously in humans and have been linked with metabolic disorders and altered adipose function. Phthalates may also present a threat to marine mammals, which need to rapidly accumulate and mobilise their large fat depots. High molecular weight (HMW) phthalates may be most problematic because they can accumulate in adipose. We used blubber explants from juvenile grey seals to examine the effects of overnight exposure to the HMW, adipogenic phthalate, benzyl butyl phthalate (BBzP) on expression of key adipose-specific genes and on phosphorylation of Akt in response to insulin. We found substantial differences in transcript abundance of Pparγ, Insig2, Fasn, Scd, Adipoq and Lep between moult stages, when animals were also experiencing differing mass changes, and between tissue depths, which likely reflect differences in blubber function. Akt abundance was higher in inner compared to outer blubber, consistent with greater metabolic activity in adipose closer to muscle than skin, and its phosphorylation was stimulated by insulin. Transcript abundance of Pparγ and Fasn (and Adipoq in some animals) were increased by short term (30 min) insulin exposure. In addition, overnight in vitro BBzP exposure altered insulin-induced changes in Pparγ (and Adipoq in some animals) transcript abundance, in a tissue depth and moult stage-specific manner. Basal or insulin-induced Akt phosphorylation was not changed. BBzP thus acted rapidly on the transcript abundance of key adipose genes in an Akt-independent manner. Our data suggest phthalate exposure could alter seal blubber development or function, although the whole animal consequences of these changes are not yet understood. Knowledge of typical phthalate exposures and toxicokinetics would help to contextualise these findings in terms of phthalate-induced metabolic disruption risk and consequences for marine mammal health.

Adverse cardiovascular effects and potential molecular mechanisms of DEHP and its metabolites-A review

Currently, cardiovascular disease (CVD) is a health hazard that is associated with progressive deterioration upon exposure to environmental pollutants. Di(2-ethylhexyl) phthalate (DEHP) has been one of the focuses of emerging concern due to its ubiquitous nature and its toxicity to the cardiovascular (CV) system. DEHP has been noted as a causative risk factor or a risk indicator for the initiation and augment of CVDs. DEHP represents a precursor that contributes to the pathogenesis of CVDs through its active metabolites, which mainly include mono (2-ethylhexyl) phthalate (MEHP). Herein, we systematically presented the association between DEHP and its metabolites and adverse CV outcomes and discussed the corresponding effects, underlying mechanisms and possibly interventions. Epidemiological and experimental evidence has suggested that DEHP and its metabolites have significant impacts on processes and factors involved in CVD, such as cardiac developmental toxicity, cardiac injury and apoptosis, cardiac arrhythmogenesis, cardiac metabolic disorders, vascular structural damage, atherogenesis, coronary heart disease and hypertension. DNA methylation, PPAR-related pathways, oxidative stress and inflammation, Ca²⁺ homeostasis disturbance may pinpoint the relevant mechanisms. The preventive and therapeutic measures are potentially related with P-glycoprotein, heat-shock proteins, some antioxidants, curcumin, apigenin, β-thujaplicin, glucagon-like peptide-1 receptor agonists and Ang-converting enzyme inhibitors and so on. Promisingly, future investigations should aid in thoroughly assessing the causal relationship and molecular interactions between CVD and DEHP and its metabolites and explore feasible prevention and treatment measures accordingly.

Di-(2-ethylhexyl) phthalate increases plasma glucose and induces lipid metabolic disorders via FoxO1 in adult mice

Di-(2-ethylhexyl) phthalate (DEHP), an endocrine-disrupting chemical (EDC) commonly used as a plasticizer, is responsible for widespread environmental pollution. Epidemiological and experimental data implicate DEHP and its metabolite mono(2-ethylhexyl) phthalate (MEHP) in the occurrence and development of metabolic syndrome. However, the specific effects and potential mechanisms of action of DEHP on glucose and lipid metabolism in adults are currently unclear. In the current study, adult male mice were continuously exposed to DEHP (0, 5, and 25 mg/kg/day) via oral administration and changes in glucose and lipid metabolism explored. Notably, exposure to DEHP led to a significant increase in plasma glucose and hepatic lipid accumulation but had no effect on insulin secretion. Western blot and real-time quantitative PCR showed that DEHP induced insulin resistance and promoted gluconeogenesis and lipid accumulation via overexpression of forkhead box protein O1 (FoxO1), in keeping with hepatic RNA sequencing data. Variations in gut microbiota aggravated these effects while inhibition of FoxO1 reversed the adverse effects of DEHP. Our findings support a key role of FoxO1 in disorders of glucose and lipid metabolism caused by DEHP.

Associating diethylhexyl phthalate to gestational diabetes mellitus via adverse outcome pathways using a network-based approach

Gestational diabetes mellitus (GDM) is a common pregnancy complication that is harmful to both the woman and fetus. Several epidemiological studies have found that exposure to diethylhexyl phthalate (DEHP), an endocrine disruptor ubiquitous in the environment, may be associated with GDM. This study aims to investigate the mechanism between DEHP and GDM using the adverse outcome pathway (AOP) framework, which can integrate information from different sources to elucidate the causal pathways between chemicals and adverse outcomes. We applied a network-based workflow to integrate diverse information to generate computational AOPs and accelerate the AOP development. The interactions among DEHP, genes, phenotypes, and GDM were retrieved from several publicly available databases, including the Comparative Toxicogenomics Database (CTD), Computational Toxicology (CompTox) Chemicals Dashboard, DisGeNET, MalaCards, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG). Based on the above interactions, a DEHP-Gene-Phenotype-GDM network consisting of 52 nodes and 227 edges was formed to support AOP construction. The filtered genes and phenotypes were assembled as molecular initiating events (MIEs) and key events (KEs) according to the upstream and downstream relationships, generating a computational AOP (cAOP) network. Based on the Organization for Economic Co-operation and Development handbook of AOPs, a cAOP was assessed and applied to determine the effects of DEHP on GDM. DEHP could increase TNF-α, downregulate the glucose uptake process, and lead to GDM. Overall, this study revealed the utility of computational methods in integrating a variety of datasets, supporting AOP development, and facilitating a better understanding of the underlying mechanism of exposure to chemicals on human health.

Phthalate exposure and risk of diabetes mellitus: Implications from a systematic review and meta-analysis

BACKGROUND

Epidemiologic studies indicated that phthalate exposure might be associated with diabetes mellitus (DM). However, discrepancies existed. The link between phthalate exposure and risk of DM remained unclarified.

METHODS

We conducted a meta-analysis to explore the association between phthalate exposure and risk of DM. Effects of phthalate exposure on insulin resistance were also evaluated by systematic review.

RESULTS

Seven studies involving 12,139 participants were included in this meta-analysis. Our results showed that urinary concentrations of phthalates were positively associated with risk of DM. The pooled ORs were 3.11 (95% CI: 1.16-8.37) for monomethyl phthalate (MMP), 1.27 (95% CI: 1.03-1.56) for mono-n-butyl phthalate (MnBP), 2.59 (95% CI: 1.10-6.10) for mono-isobutyl phthalate (MiBP), 1.99 (95% CI: 1.52-2.61) for mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), 1.90 (95% CI: 1.40-2.57) for mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), 1.55 (95% CI: 1.10-2.20) for mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), and 2.39 (95% CI: 1.18-4.85) for mono-(3-carboxypropyl) phthalate (MCPP), respectively. Molar summation of di-2-ethylhexyl phthalate metabolites (∑DEHP) was also found to be correlated with risk of DM (OR 2.15, 95% CI: 1.48-3.13). No significant association with risk of DM was found regarding monoethyl phthalate (MEP), monobenzyl phthalate (MBzP) and mono(2-ethylhexyl) phthalate (MEHP). In literature review, most studies showed positive correlations of phthalates, especially ∑DEHP, with homeostasis model assessment of insulin resistance and fasting glucose.

CONCLUSION

Exposure to phthalates, especially MMP, MnBP, MiBP, MCPP and DEHP metabolites, might be a risk factor of DM. Our results should be interpreted with caution due to heterogeneous design of enrolled studies.

Short-term exposure to acrylamide exacerbated metabolic disorders and increased metabolic toxicity susceptibility on adult male mice with diabetes

Diabetes mellitus is a common endocrine metabolic disorder, and previous studies have shown that diabetics are more sensitive to the toxic environmental contaminants. Acrylamide (ACR) is both an industrially multipurpose compound and a common endogenous food contaminant to which people are frequently exposed and at high risk. However, the toxicity of ACR on diabetes hasn't attracted much attention. In this study, both healthy mice and diabetic mice received ACR administration orally to investigate the ACR-induced metabolic toxicity, mechanism and susceptibility to ACR toxicity in adult diabetic male mice. The results showed that ACR significantly increased FBG level and decreased bodyweight, serum lipid and liver lipid biomarkers (TC, TG, LDL-C, HDL-C) levels as well as expression of lipid and glucose metabolism-related genes in diabetic mice, indicating that ACR can exacerbate metabolic disorders of glucose and lipid in diabetic male mice. Moreover, ACR exposure significantly increased levels of MDA and COX-2), decreased GSH level and antioxidant enzyme activity (SOD, GSH-PX and CAT) by downregulating expression of Nrf2 and Keap1 in diabetic mice. Factorial analysis showed ACR had a more significant disturbance in diabetic mice compared with healthy mice. Our results indicated that ACR exposure can cause oxidative stress and inflammatory damage, which can exacerbate abnormal glucose and lipid metabolism. This work helps to elucidate the effects and underlying mechanisms of ACR-induced metabolic toxicity in adults with diabetes.

Integrated metabolomics and transcriptomics reveal di(2-ethylhexyl) phthalate-induced mitochondrial dysfunction and glucose metabolism disorder through oxidative stress in rat liver

Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous pollutant that results in hepatotoxicity. However, an understanding of the systematic mechanism of hepatic injury caused by DEHP remains limited. Here, we performed a comprehensive metabolomics and transcriptomics analyses to describe hepatic responses of rats to long-term DEHP exposure and, together with pathology and functional injury of liver, systematically analyzed the pathogenesis and mechanisms of liver damage. SD rats were exposed to 0 and 600 mg/kg/day DEHP for 12 weeks. Thereafter, biochemical indicators and histopathological changes regarding liver function were detected. Metabolomics and transcriptomics profiles of rat liver samples were analyzed using a UPLC-MS/MS system and Illumina Hiseq 4000, respectively. DEHP induced hepatocyte structural alterations and edema, depressed monooxygenase activity, decreased antioxidant activities, aggravated oxidative damage, blocked the tricarboxylic acid cycle and respiratory chain, and disturbed glucose homeostasis in the liver. These findings indicate that reactive oxygen species play a major role in these events. Overall, this study systematically depicts the comprehensive mechanisms of long-term DEHP exposure to liver injury and highlights the power of metabolomics and transcriptomics platforms in the mechanistic understanding of xenobiotic hepatotoxicity.

Glycolipid metabolism and liver transcriptomic analysis of the therapeutic effects of pressed degreased walnut meal extracts on type 2 diabetes mellitus rats

Walnut meal (WM) is rich in polyphenols which exhibit multiple therapeutic effects. The purpose of this study was to investigate the therapeutic effects of walnut meal extracts (WMP) on glycolipid metabolism and liver transcriptomics in T2DM rats. A T2DM rat model was established by using a high-fat diet combined with streptozotocin. A 5-week WMP therapy showed the effects of decreasing water intake, excretion, fasting blood glucose, fasting insulin, and insulin resistance, increasing β-cell function and insulin sensitivity index; meanwhile regulating dysfunctional lipid metabolism and reducing inflammation; improving body weight, oral glucose tolerance test and insulin sensitivity; and increasing the activities of SOD and CAT while decreasing the MDA levels in the liver and serum of T2DM rats. Moreover, 10 key differentially expressed genes were identified by RNA-seq, including Gck, RT1-Ba, Fasn, Slc13a3, Cd74, Jun, Cyp4a1, Myh7b, Plin3, and Got1, and they were highly potentially related to glycolipid metabolism. Our results suggested that WMP exhibited the anti-diabetic effect and could regulate glycolipid metabolism in T2DM rats. This finding might assist in identifying potential therapeutic targets for T2DM prevention and intervention.

Short-term exposure of decabromodiphenyl ether in female adult Balb/c mice: Immune toxicity and self-recovery

As a typical persistent organic pollutant, decabromodiphenyl ether (BDE-209) is associated with various health risks, especially on immune system, which is sensitive to environmental pollutants. In addition, there is a problem of multi-index estimation and lack of comprehensive evaluation in immune toxicity study. In this study, the immunotoxicity of BDE-209 was systematically estimated from the aspects of immunopathology, humoral immunity, cellular immunity and non-specific immunity, etc., and integrated biomarker responses (IBR) combined with principal component analysis was applied to comprehensively evaluate the immunotoxicity of BDE-209 and its self-recovery after discontinuation. Results showed that BDE-209 exposure could cause immunotoxicity. This response seems to depend on (1) atrophying immune organs (thymus and spleen), hepatomegaly accompanied by increasing aspartate aminotransferase and oxidative stress;(2) changing humoral (immunoglobulins) and cellular (lymphocyte proliferation and cytokine secretion) immunity indices; (3) altering related expressions of genes, and further leading to imbalance of Th1/Th2 (Th, helper T cell). Integrated biomarker responses (IBR) companied with principal component analysis selected five biomarkers (mRNA expression of GATA-3, malondialdehyde level in thymus, count of white blood cell, serum IgG and lipopolysaccharide-induced splenic lymphocyte proliferation) to clarify the immunotoxicity induced by BDE-209. Furthermore, IBR combined with factorial analysis revealed that the effect of BDE-209 could be dose-dependently reduced after withdrawal of BDE-209. Overall results suggested that BDE-209 has immunotoxicity on adult Balb/c mice, whereas this immunotoxicity could be reduced by the self-regulation of organisms to some extent.

Di-(2-ethylhexyl) phthalate-induced hepatotoxicity exacerbated type 2 diabetes mellitus (T2DM) in female pubertal T2DM mice

Di-(2-ethylhexyl) phthalate (DEHP), one of the most common plasticizers, is closely associated with a high prevalence of pubertal type 2 diabetes mellitus (T2DM). Numerous studies have indicated that DEHP-induced metabolic toxicity exhibits sex differences. In this study, the sex differences in the effect of DEHP on pubertal T2DM (P-T2DM) mice, the susceptibility of female P-T2DM mice to DEHP-induced metabolic toxicity, and the underlying mechanisms were investigated. DEHP exposure exacerbated metabolic disorders in female P-T2DM mice. Factorial analysis showed that female P-T2DM mice were more sensitive to DEHP exposure than female normal mice and male P-T2DM mice. It was determined by integrated biomarker response results that female P-T2DM mice had higher risks of developing T2DM, metabolic disorders, cardiovascular events and hepatotoxicity than male P-T2DM mice. Moreover, hepatic transcriptome analysis emphasized the effects of DEHP on the expression of oxidative injury- and metabolic function-related genes. Western blotting indicated that DEHP activated Jun-N-terminal kinase (JNK) and impaired insulin sensitivity in the liver, which were the main causes of DEHP-exacerbated metabolic abnormalities in P-T2DM mice. Our study revealed that compared with normal mice and male P-T2DM mice, female P-T2DM mice tend to suffer from increased DEHP-induced metabolic toxicity, which was primarily attributed to hepatotoxicity.

Metabolic, reproductive and thyroid effects of bis(2-ethylhexyl) phthalate (DEHP) orally administered to male and female juvenile rats at dose levels derived from children biomonitoring study

Bis(2-ethylhexyl) phthalate (DEHP) is a plasticizer used in several items, non-covalently bound to plastics and easily released, since metabolites were found in human matrices. DEHP is an endocrine disrupter and children are particularly vulnerable and susceptible to DEHP effects due to higher exposure levels and developmental stage. A juvenile toxicity study was performed to identify DEHP hazard and mode of action in Sprague-Dawley rats of both sexes during peri-pubertal period - corresponding to childhood phase - from weaning, post-natal day (PND) 23, to full sexual maturity (PND60); the dose levels of 0, 9, 21 and 48 mg/kg bw/day were derived from LIFE PERSUADED biomonitoring study in children. DEHP was administered by gavage for 28 days (5 days/week); timing of preputial separation and vaginal opening was observed during treatment. Histopathological analysis was performed on: adrenals, spleen, liver, thyroid and reproductive organs. The following serum biomarkers were assessed: estradiol, testosterone, anti-Mullerian hormone, tetraiodothyronine, thyroid stimulating hormone, adiponectin and leptin. Gene expression on hypothalamic-pituitary area was focused on follicle stimulating, luteinizing, and thyroid stimulating hormones. The results showed that main targets of DEHP during juvenile period were liver and metabolic system in both sexes, while sex-specific effects were recorded in reproductive system (male rats) and in thyroid (female rats). DEHP exposure during peri-pubertal period at dose levels derived from biomonitoring study in children can induce sex-specific imbalances identifying the juvenile animal model as a sound tool to identify hazards for a reliable risk assessment targeted to children.