Di-(2-ethylhexyl) phthalate induces testicular endoplasmic reticulum stress and germ cell apoptosis in adolescent mice

Rosa roxburghii juice alleviates DEHP-induced reproductive system damage in male mice via the PI3K/AKT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Rosa roxburghii is an ethnic medicinal herb. Folk medicine collections have documented its nourishing and strengthen effects. It has been used to improve reproductive health, but scientific evidence supporting its efficacy and mechanisms remains limited.

AIM OF THIS STUDY

Endocrine-disrupting chemicals, such as di-(2-ethylhexyl) phthalate (DEHP), are known to impair male reproductive health. This study aims to investigate the protective effects of raw Rosa roxburghii juice (RRJ) on DEHP-induced reproductive toxicity in mice and elucidates its underlying mechanisms.

MATERIALS AND METHODS

Using a DEHP-induced murine model of reproductive damage, we evaluated the effects of RRJ on sperm quality, testicular histopathology, reproductive endocrine function, oxidative stress, inflammation, apoptosis, and DNA damage. Network pharmacology analysis was performed to identify the active components, targets, and mechanisms underlying the therapeutic effects of Rosaroxburghii.

RESULTS

Our data demonstrated that RRJ significantly improved sperm quality, alleviated testicular atrophy, restored endocrine disorders, and mitigated oxidative stress, inflammation, and apoptosis in testicular tissues. Additionally, RRJ reduced testicular and sperm DNA damage, as evidenced by decreased γ-H2AX expression and DNA fragmentation index. Network pharmacology analysis identified quercetin, apigenin, luteolin, kaempferol, eriodictyol, and ellagic acid as the key bioactive compounds in RRJ, with the PI3K/AKT signaling pathway playing a crucial role in its therapeutic effects. Western blotting confirmed that RRJ reversed DEHP-induced suppression of the PI3K/AKT pathway.

CONCLUSIONS

This study demonstrates that RRJ protects against DEHP-induced reproductive toxicity through antioxidant, anti-inflammatory, and anti-apoptotic mechanisms, mediated in part by the PI3K/AKT signaling pathway. This work provides the first comprehensive evidence of the protective effects of Rosa roxburghii against male reproductive system damage and its underlying mechanisms.

Sulforaphane substantially impedes testicular ferroptosis in adult rats exposed to di-2-ethylhexyl phthalate through activation of NRF-2/SLC7A11/GPX-4 trajectory

Di-2-ethylhexyl phthalate (DEHP) is a common plasticizer with a deleterious impact on testicular functionality and male fertility. Growing evidence implicates ferroptosis as one of the plausible mechanisms for DEHP-induced testicular injury. Sulforaphane (SFN) is a natural isothiocyanate displaying beneficial effects on testicular injury in several animal models. Herein, we explored the potential protective effect of SFN on testicular ferroptosis and toxicity evoked by DEHP. Adult male Wistar rats were equally distributed into three groups (n = 6/group): (i) CON group; (ii) DEHP group, received DEHP (2 g/kg PO) for 4 weeks; and (iii) DEHP + SFN group, received SFN (10 mg/kg, PO) 1 week prior to DEHP then concurrently with DEHP for further 4 weeks. Compared to CON group, exposure to DEHP caused testicular atrophy, deteriorated testicular architecture, testicular fibrosis, reduced sperm count and motility, higher sperm deformity, and declined serum testosterone level. All these abnormalities were ameliorated by SFN preconditioning. Additionally, pretreatment with SFN reversed the increased aromatase level and upregulated the steroidogenic markers in testes of DEHP-exposed rats. SFN pretreatment also counteracted DEHP-induced oxidative stress and boosted the total antioxidant capacity in testicular tissue via activation of the nuclear factor erythroid 2-related factor 2 (NRF-2) and its downstream target, hemeoxygenase-1 (HO-1). Moreover, SFN preconditioning mitigated DEHP-induced ferroptosis through up-surging SLC7A11, GPX-4, and GSH, while suppressing iron overload and ACSL4-induced lipid peroxidation in testicular tissue of rats. These findings may nominate SFN as a promising protective intervention to alleviate testicular ferroptosis associated with DEHP exposure through activation of NRF-2/SLC7A11/GPX-4 trajectory.

DEHP-mediated oxidative stress leads to impaired testosterone synthesis in Leydig cells through the cAMP/PKA/SF-1/StAR pathway

Leydig cells (LCs) injury is often irreversible upon discovery; hence, early identification of risk factors for injury is crucial. The ubiquitous plasticizer di-2-ethylhexyl phthalate (DEHP) in the environment has been shown to potentially cause damage to LCs. However, the underlying mechanisms remain unclear. The present study utilized scRNA-seq analysis, the advantage of which is the ability to explore the characteristics of various testicular cells, combined with studies in vitro and in vivo, to assay the changes in and damage processes of LCs during DEHP exposure. We found that DEHP disrupted the structure and function of LCs. GO analysis suggested that a series of pathways changed, among which the most significant were the "steroid synthesis" and "oxidative stress" pathways. Moreover, DEHP dramatically changed the manner of interaction between LCs and other cells, and the most significant type was the cell-cell contact, which included NECTIN, APP, CADM, and CD39. In addition, the activity of multiple transcription factors (TFs) decreased after DEHP exposure, and the activity of steroidogenic factor 1 (SF-1, Nr5a1) was the most obviously altered. Next, we found that the LCs region indeed experienced oxidative stress, including increased ROS signals, the decreased SOD activity and T-AOC, and increased concentration of 8-OHdG and MDA content. The testosterone level, as well as the expression of StAR, P450scc, and 3β-HSD, was also reduced. To study the association between testosterone synthesis and oxidative stress, the antioxidants N-acetyl-L-cysteine (NAC) and H2O2 were used, and we found that mono-2-ethylhexyl ester (MEHP, a major biometabolite of DEHP) disrupted testosterone synthesis through the inhibition of the cAMP/PKA/SF-1/StAR pathway by inducing oxidative stress. Our study provides new insights into the role and mechanisms of DEHP in LCs injury.

Revealing the core suppression effects of various Di (2-ethylhexyl) phthalate exposure on early meiosis progression in postnatal male mice via single-cell RNA sequencing

The male reproductive system has been the subject of considerable attention in recent years due to the adverse effects of Di (2-ethylhexyl) phthalate (DEHP). Although previous research has suggested that DEHP exposure hinders the early meiotic progression of male germ cells, the underlying mechanisms are still not well understood. The transcriptomic changes in testicular cells of postnatal male rodents following DEHP exposure were meticulously analyzed using 10X Genomics single-cell RNA sequencing in this study. For downstream analysis, we acquired 42,000 cells and generated 3172,754,990 reads. DEHP exposure at concentrations of 40 μg/kg/day (DEHP40) and 80 μg/kg/day (DEHP80) substantially decreased the proportion of pachytene and diplotene spermatocytes, indicating a shared inhibitory effect on early meiosis, as demonstrated by our findings. In addition, DEHP exposure disrupted the cellular communication between Sertoli cells and germ cells, which had a significant impact on the p38-MAPK signaling pathway. The expression of key ligand genes Tgfb1 and Tgfb3 in Sertoli cells was significantly reduced. DEHP exposure resulted in a substantial decrease in the expression of the Trp53 gene, which in turn down-regulated three critical downstream genes (Stmn1, Tubb5, and Ccnb1) that are implicated in spindle organization from a mechanistic perspective. This study offers the first comprehensive evidence that DEHP inhibits early meiotic progression in male germ cells through the Trp53-mediated p38-MAPK pathway, providing crucial insights into the molecular mechanisms underlying DEHP-induced male reproductive toxicity. Our results emphasize the enduring negative effects of DEHP exposure on male fertility, which have substantial ramifications for the comprehension and mitigation of the influence of environmental estrogens on reproductive health.

Mixtures of phthalates disrupt expression of genes related to lipid metabolism and peroxisome proliferator-activated receptor signaling in mouse granulosa cells

Phthalates are a class of known endocrine-disrupting chemicals that are found in common everyday products. Several studies associate phthalate exposure with detrimental effects on ovarian function, including growth and development of the follicle and production of steroid hormones. We hypothesized that dysregulation of the ovary by phthalates may be mediated by phthalate toxicity towards granulosa cells, a major cell type in ovarian follicles responsible for key steps of hormone production and nourishing the developing oocyte. To test the hypothesis that phthalates target granulosa cells, we harvested granulosa cells from adult CD-1 mouse ovaries and cultured them for 96 h in vehicle control, a phthalate mixture, or a phthalate metabolite mixture (0.1 to 100 μg/ml). After culture, we measured metabolism of the phthalate mixture into monoester metabolites by the granulosa cells, finding that granulosa cells do not significantly contribute to ovarian metabolism of phthalates. Immunohistochemistry of phthalate metabolizing enzymes in whole ovaries confirmed that these enzymes are not strongly expressed in granulosa cells of antral follicles and that ovarian metabolism of phthalates likely occurs primarily in the stroma. RNA sequencing of treated granulosa cells identified 407 differentially expressed genes, with overrepresentation of genes from lipid metabolic processes, cholesterol metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Expression of significantly differentially expressed genes related to these pathways was confirmed using qPCR. Our results agree with previous findings that phthalates and phthalate metabolites have different effects on the ovary, but both interfere with PPAR signaling in granulosa cells.

Impact of DEHP on mitochondria-associated endoplasmic reticulum membranes and reproductive toxicity in ovary

Di(2-ethylhexyl) phthalate (DEHP) is a widely recognized environmental endocrine disruptor that potentially impacts female reproductive function, although the specific mechanisms leading to such impairment remain unclear. A growing body of research has revealed that the endoplasmic reticulum and mitochondrial function significantly influence oocyte quality. The structure of mitochondria-associated endoplasmic reticulum membranes (MAMs) is crucial for facilitating the exchange of Ca2+, lipids, and metabolites. This study aimed to investigate the alterations in the composition and function of MAMs after DEHP exposure and to elucidate the underlying mechanisms of ovarian toxicity. The female mice were exposed to DEHP at doses of 5 and 500 mg/kg/day for one month. The results revealed that DEHP exposure led to reduced serum anti-Müllerian hormone levels and increased atretic follicles in mice. DEHP induced endoplasmic reticulum stress and disrupted calcium homeostasis in oocytes. Furthermore, DEHP impaired the mitochondrial function of oocytes and reduced their membrane potential, and promoting apoptosis. Similar results were observed in human granulosa cells after exposure to mono-(2-ethylhexyl) phthalate (MEHP, metabolites of DEHP) in vitro. Proteomic analysis and transmission electron microscopy revealed modifications in the functional proteins and structure of the MAMs, and the suppression of oxidative phosphorylation pathways. The findings of this investigation provide a new perspective on the mechanism underlying the reproductive toxicity of DEHP in females.

Mixtures of phthalates disrupt expression of genes related to lipid metabolism and peroxisome proliferator-activated receptor signaling in mouse granulosa cells

Phthalates are a class of known endocrine disrupting chemicals that are found in common everyday products. Several studies associate phthalate exposure with detrimental effects on ovarian functions, including growth and development of the follicle and production of steroid hormones. We hypothesized that dysregulation of the ovary by phthalates may be mediated by phthalate toxicity towards granulosa cells, a major cell type in ovarian follicles responsible for key steps of hormone production and nourishing the developing oocyte. To test the hypothesis that phthalates target granulosa cells, we harvested granulosa cells from adult CD-1 mouse ovaries and cultured them for 96 hours in vehicle control, a phthalate mixture, or a phthalate metabolite mixture (0.1-100 μg/mL). After culture, we measured metabolism of the phthalate mixture into monoester metabolites by the granulosa cells, finding that granulosa cells do not significantly contribute to ovarian metabolism of phthalates. Immunohistochemistry of phthalate metabolizing enzymes in whole ovaries confirmed that these enzymes are not strongly expressed in granulosa cells of antral follicles and that ovarian metabolism of phthalates likely occurs primarily in the stroma. RNA sequencing of treated granulosa cells identified 407 differentially expressed genes, with overrepresentation of genes from lipid metabolic processes, cholesterol metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Expression of significantly differentially expressed genes related to these pathways were confirmed using qPCR. Our results agree with previous findings that phthalates and phthalate metabolites have different effects on the ovary and interfere with PPAR signaling in granulosa cells.

Recent advances in toxicological research of di-(2-ethylhexyl)-phthalate: Focus on endoplasmic reticulum stress pathway

The plasticizer di-(2-ethylhexyl)-phthalate (DEHP) is the most significant phthalate in production, usage, and environmental occurrence. DEHP is found in products such as personal care products, furniture materials, cosmetics, and medical devices. DEHP is noncovalently bind with plastic therefore, repeated uses lead to leaching out of it. Exposure to DEHP plasticizers leads to toxicity in essential organs of the body through various mechanisms. The main objective of this review article is to focus on the DEHP-induced endoplasmic reticulum (ER) stress pathway implicated in the testis, brain, lungs, kidney, heart, liver, and other organs. Not only ER stress, PPAR-related pathways, oxidative stress and inflammation, Ca2+ homeostasis disturbances in mitochondria are also identified as the relative mechanisms. ER is involved in various critical functions of the cell such as Protein synthesis, protein folding, calcium homeostasis, and lipid peroxidation but, DEHP exposure leads to augmentation of misfolded/unfolded protein. This review complies with various recently reported DEHP-induced toxicity studies and some pharmacological interventions that have been shown to be effective through ER stress pathway. DEHP exposure does assess health risks and vulnerability to populations across the globe. This study offers possible targets and approaches for addressing various DEHP-induced toxicity.

Disruption of gonocyte development following neonatal exposure to di (2-ethylhexyl) phthalate

Pre- and/or post-natal administrations of di(2-ethylhexyl) phthalate (DEHP) in experimental animals cause alterations in the spermatogenesis. However, the mechanism by which DEHP affects fertility is unknown and could be through alterations in the survival and differentiation of the gonocytes. The aim of the present study was to evaluate the effect of a single administration of DEHP in newborn mice on gonocytic proliferation, differentiation and survival and its long-term effects on seminiferous epithelium and sperm quality. BALB/c mice distributed into Control and DEHP groups were used. Each animal in the DEHP group was given a single dose of 500 mg/Kg at birth. The animals were analyzed at 1, 2, 4, 6, 8, 10 and 70 days postpartum (dpp). Testicular tissues were processed for morphological analysis to determine the different types of gonocytes, differentiation index, seminiferous epithelial alterations, and immunoreactivity to Stra8, Pcna and Vimentin proteins. Long-term evaluation of the seminiferous epithelium and sperm quality were carried out at 70 dpp. The DEHP animal group presented gonocytic degeneration with delayed differentiation, causing a reduction in the population of spermatogonia (Stra8 +) in the cellular proliferation (Pcna+) and disorganization of Vimentin filaments. These events had long-term repercussions on the quality of the seminiferous epithelium and semen. Our study demonstrates that at birth, there is a period that the testes are extremely sensitive to DEHP exposure, which leads to gonocytic degeneration and delay in their differentiation. This situation can have long-term repercussions or permanent effects on the quality of the seminiferous epithelium and sperm parameters.

Protective effects of melatonin on DEHP-induced apoptosis and oxidative stress in prepubertal testes via the PI3K/AKT pathway

Di(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, is one of the most common plasticizers and is widely used in various plastic products. DEHP induces apoptosis and oxidative stress and has been shown to have androgenic toxicity. However, the methods to combat DEHP-induced testicular damage and the mechanisms involved remain to be elucidated. In the present study, we used melatonin, which has strong antioxidant properties, to intervene in prepubertal mice and mouse Leydig cells (TM3) treated with DEHP or its metabolite mono(2-ethylhexyl) phthalate (MEHP). The results showed that melatonin protected against DEHP-induced testicular damage in prepubertal mice, mainly by protecting against DEHP-induced structural destruction of the germinal tubules and by attenuating the DEHP-induced decrease in testicular organ coefficients and testosterone levels. Transcriptomic analysis found that melatonin may attenuate DEHP-induced oxidative stress and apoptosis in prepubertal testes. In vitro studies further revealed that MEHP induces oxidative stress injury and increases apoptosis in TM3 cells, while melatonin reversed this damage. In vitro studies also found that MEHP exposure inhibited the expression levels of molecules related to the PI3K/AKT signaling pathway, and melatonin reversed this change. In conclusion, these findings suggest that melatonin protects against DEHP-induced prepubertal testicular injury via the PI3K/AKT signaling pathway, and provide a theoretical basis and experimental rationale for combating male reproductive dysfunction.

Mitochondrial dysfunction and endoplasmic reticulum stress induced by activation of PPARα leaded testicular to apoptosis in SD rats explored to di-(2-ethylhexyl) phthalate (DEHP)

Di-2-ethylhexyl phthalate (DEHP), as a common endocrine disrupting chemicals, can induce toxicity to reproductive system. However, the mechanism remains to be explored. In our study, DEHP exposure induced testicular injury in rats. The high throughput transcriptional sequencing was performed to identify differentially expressed genes (DEGs) between the treatment and control groups. KEGG analysis revealed that DEGs were enriched in apoptosis, PPARα, and ER stress pathway. DEHP up-regulated the expression of PPARα, Bax, Bim, caspase-4. GRP78, PERK, p-PERK, eIF2α, p-eIF2α, ATF4 and CHOP. This view has also been confirmed in TM3 and TM4 cells. In vitro, after pre-treatment with GW6471 (an inhibitor of PPARα) or GSK (an inhibitor of PERK), the apoptosis was inhibited and mitochondrial dysfunction was improved. Moreover, the improvement of mitochondrial dysfunction decreased the expression of PERK pathway by using SS-31(a protective agent for mitochondrial function). Interestingly, ER stress promoted the accumulation of ROS by ERO1L (the downstream of CHOP during ER stress), and the ROS further aggravated the ER stress, thus forming a feedback loop during the apoptosis. In this process, a vicious cycle consisting of PERK, eIF2α, ATF4, CHOP, ERO1L, ROS was involved. Taken together, our results suggested that mitochondrial dysfunction and ER stress-ROS feedback loop caused by PPARα activation played a crucial role in DEHP-induced apoptosis. This work provides insight into the mechanism of DEHP-induced reproductive toxicity.

Lycopene prevents Di-(2-ethylhexyl) phthalate-induced mitophagy and oxidative stress in mice heart via modulating mitochondrial homeostasis

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer that is easily found in the environment. Excessive daily exposure of it may lead to an increased risk of cardiovascular disease (CVD). Lycopene (LYC), as a natural carotenoid, has been shown to have the potential to prevent CVD. However, the mechanism of LYC on cardiotoxicity caused by DEHP exposure is unknown. The research was aimed to investigate the chemoprotection of LYC on the cardiotoxicity caused by DEHP exposure. Mice were treated with DEHP (500 mg/kg or 1,000 mg/kg) and/or LYC (5 mg/kg) for 28 d by intragastric administration, and the heart was subjected to histopathology and biochemistry analysis. The results indicated that DEHP caused cardiac histological alterations and enhanced the activity of cardiac injury indicators, and interfered with mitochondrial function and activating mitophagy. Notably, LYC supplementation could inhibit DEHP-induced oxidative stress. The mitochondrial dysfunction and emotional disorder caused by DEHP exposure were significantly improved through the protective effect of LYC. We concluded that LYC enhances mitochondrial function by regulating mitochondrial biogenesis and dynamics to antagonize DEHP-induced cardiac mitophagy and oxidative stress.

Ferroptosis is critical for phthalates driving the blood-testis barrier dysfunction via targeting transferrin receptor

The global rate of human male infertility is rising at an alarming rate owing to environmental and lifestyle changes. Phthalates are the most hazardous chemical additives in plastics and have an apparently negative impact on the function of male reproductive system. Ferroptosis is a recently described form of iron-dependent cell death and has been linked to several diseases. Transferrin receptor (TfRC), a specific ferroptosis marker, is a universal iron importer for all cells using extracellular transferrin. We aim to investigate the potential involvement of ferroptosis during male reproductive toxicity, and provide means for drawing conclusions on the effect of ferroptosis in phthalates-induced male reproductive disease. In this study, we found that di (2-ethylhexyl) phthalate (DEHP) triggered blood-testis barrier (BTB) dysfunction in the mouse testicular tissues. DEHP also induced mitochondrial morphological changes and lipid peroxidation, which are manifestations of ferroptosis. As the primary metabolite of DEHP, mono-2-ethylhexyl phthalate (MEHP) induced ferroptosis by inhibiting glutathione defense network and increasing lipid peroxidation. TfRC knockdown blocked MEHP-induced ferroptosis by decreasing mitochondrial and intracellular levels of Fe²⁺. Our findings indicate that TfRC can regulate Sertoli cell ferroptosis and therefore is a novel therapeutic molecule for reproductive disorders in male patients with infertility.

Single-cell transcriptomic profiling to evaluate the effects of Di(2-ethylhexyl)phthalate exposure on early meiosis of female mouse germ cells

Di(2-ethylhexyl)phthalate (DEHP) has proven characteristics of an endocrine-disrupting compound (EDC), which can threaten the reproductive health of humans and other animals. In mammals, a series of chromosomal events occur during the meiotic stage of oocytes. External toxins may enter the body and cause infertility and other related diseases. Therefore, it is crucial to explore the influence of DEHP exposure on the molecular mechanism of germ cell meiosis. We used single-cell RNA sequencing (scRNA-seq) to analyse the ovaries of foetal mice at embryonic day 12.5 (E12.5) and E14.5 after maternal DEHP exposure. DEHP exposure further activated the pathways related to DNA repair in germ cells, increased the expression of genes related to DNA damage and changed the developmental trajectory of germ cells. DEHP exposure may affect the proliferation of pregranulosa (PG) cells. Moreover, DEHP exposure altered the signal transduction between PG cells and germ cells. We showed that DEHP affects meiosis by causing DNA damage in oocytes and disrupting the signal transduction between PG cells and germ cells. These results provide a strong theoretical basis for the prevention and treatment of DEHP-mediated female reproductive health problems.

Di-(2-ethyl hexyl) phthalate induced oxidative stress promotes microplastics mediated apoptosis and necroptosis in mice skeletal muscle by inhibiting PI3K/AKT/mTOR pathway

The plastic decomposition product microplastics (MPs) and the plastic additive Di (2-ethylhexyl) phthalate (DEHP) in the environment can damage various organs of the organism by inducing oxidative stress. The PI3K/AKT/mTOR signaling pathway participate in toxin-induced apoptosis and necroptosis. However, the effects of DEHP/MPs alone and combined exposure on skeletal muscle cell injury in mice and the role of PI3K/AKT/mTOR axis remain unclear. To investigate the effect of DEHP or/and MPs on skeletal muscle in mice and its possible toxicological mechanism, 60 mice were randomly divided into control group, DEHP group (DEHP 200 mg/kg dissolved in 50 mL corn oil mixed with 2.5 kg diet), MPs group (10 mg/L MPs in drinking water) and combined exposure group. In vitro, C2C12 cells were exposed to DEHP 600 μM/MPs 800 μM alone or in combination for 24 h. The results showed that DEHP/MPs exposure alone or in combination increased MDA content, decreased activities of CAT, T-AOC, SOD and GSH-Px, increased mRNA and protein expressions of Caspase-3, BAX, RIPK1, RIPK3 and MLKL, and decreased BCL-2 expression. The expression of PI3K/AKT/mTOR signaling pathway was significantly down-regulated. All the above results showed that the combined exposure group was more toxic, and similar experimental results were obtained by DEHP/MPs exposure test of C2C12 cells in vitro. It is suggested that DEHP/MPs can induce apoptosis and necroptosis by activating oxidative stress and down-regulating PI3K/AKT/mTOR pathway. This study provides new evidence for clarifying the possible mechanism of toxicity of DEHP and MPs to skeletal muscle of mice.

Effects of Lycium barbarum glycopeptide on renal and testicular injury induced by di(2-ethylhexyl) phthalate

Di(2-ethylhexyl) phthalate (DEHP) is a common environmental pollutant with renal and reproductive toxicity. Lycium barbarum glycopeptide (LbGp) is the main active component of Lycium barbarum, which can protect the kidney and promote reproduction. Autophagy and apoptosis are the regulatory mechanisms of cell adaptation to external stress. This study investigated whether DEHP and LbGp affect kidney and testis by regulating autophagy and apoptosis. DEHP induced apoptosis in human embryonic kidney-293 (HEK-293) cells and human kidney-2 (HK-2) cells, as well as glomerular enlargement, enhanced renal autophagy and inflammation, decreased testicular germ cells, and enhanced testicular autophagy. LbGp reduced apoptosis in HEK-293 cells and HK-2 cells, reduced glomerular enlargement and renal inflammation, enhanced renal autophagy, increased testicular germ cells, and alleviated testicular autophagy. These results suggested that DEHP induced inflammation to cause kidney injury, mildly enhanced renal autophagy, and also induced excessive autophagy, leading to testicular injury. LbGp reduced inflammation and appropriately enhanced autophagy to alleviate renal injury and also reduced excessive autophagy to alleviate testicular injury. Silent information regulator 1 (SIRT1)/forkhead box O3a (FoxO3a)-mediated autophagy and p38 mitogen-activated protein kinase (p38 MAPK)-mediated inflammation played important roles.

Lycopene regulates the mitochondrial unfolded protein response to prevent DEHP-induced cardiac mitochondrial damage in mice

Lycopene (LYC), as a kind of carotene, has antioxidant effects. Di(2-ethylhexyl) phthalate (DEHP) was used to improve the flexibility of plastics. However, the potential role of LYC in DEHP induced cardiac injury in mice remains unclear. Therefore, the aim of this study was to investigate the role and mechanism of LYC in DEHP induced cardiac injury. Male ICR mice were treated with DEHP (500 or 1000 mg per kg BW per day) and/or LYC (5 mg per kg BW per day) for 28 days. The results of histopathology and ultrastructure showed that LYC relieved the decrease of mitochondrial volume density and myocardial fibre disorder induced by DEHP. Subsequently, LYC attenuated DEHP-induced mitochondrial damage, mitochondrial unfolded protein response (UPR^mt) activation, nuclear factor erythroid 2-related factor 2 (Nrf2) mediated oxidative stress and heat shock response (HSR) activation induced by DEHP. LYC regulates UPR^mt to prevent DEHP-induced cardiac mitochondrial damage. Thus, this study provided new evidence of UPR^mt as a target for LYC treatment preventing DEHP-induced cardiac disease.

Multiple transcriptomic profiling: potential novel metabolism-related genes predict prepubertal testis damage caused by DEHP exposure

The toxic effect of di(2-ethylhexyl) phthalate (DEHP) on prepubertal testes was examined in this study. We treated 3-week-old male mice with 4.8 mg/kg/day (milligram/kilogram/day) (no observed adverse effect level), 30 mg/kg/day (high exposure dose relative to humans), 100 mg/kg/day (level causing a reproductive system disorder), and 500 mg/kg/day (dose causing a multigenerational reproductive system disorder) of DEHP via gavage. Obvious abnormalities in the testicular organ coefficient, spermatogenic epithelium, and testosterone levels occurred in the 500 mg/kg DEHP group. Ribonucleic acid sequencing (RNA-seq) showed that differentially expressed genes (DEGs) in each group could enrich reproduction and reproductive process terms according to the gene ontology (GO) results, and coenrichment of metabolism pathway was observed by the Reactome pathway analysis. Through the analysis of common genes in the metabolism pathway, we discovered that DEHP exposure at 4.8 to 500 mg/kg or 100 mg/kg caused the same damages to the prepubertal testis. In general, we identified two key transcriptional biomarkers (fatty acid binding protein 3 (Fabp3) and carboxylesterase (Ces) 1d), which provided new insight into the gene regulatory mechanism associated with DEHP exposure and will contribute to the prediction and diagnosis of prepuberty testis injury caused by DEHP.