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Di-n-butyl phthalate (DBP) is a pollutant that is widely present in the environment. We have previously demonstrated that maternal exposure to DBP resulted in renal fibrosis in offspring, but the underlying mechanism was not well elucidated. Therefore, the current study aims to understand the underlying molecular mechanisms in these sex-specific developmental alterations. Here, we used RNA-seq analysis to explore the underlying molecular mechanisms of DBP-associated renal fibrosis. Pregnant rats received DBP orally at a dose of 850 mg/kg BW/day during gestational days 14-18. Upregulated autophagy in renal tubules in offspring was confirmed in the DBP-treated group via accessing LC3Ⅱ/Ⅰ protein expression. Increased expression of the HhIP gene was found in the DBP-treated group via RNA-seq analysis. Immunohistochemistry (IHC) staining and Western blot analysis confirmed increased expression of HhIP protein and inhibited hedgehog signaling. Increased HhIP expression further leaded to impaired activation of hedgehog signaling, which is critical for normal embryonic development. Additional in vitro experiments on renal tubular cells suggest that inactivation of hedgehog signaling induced autophagy in renal tubular cells. Taken together, our findings show that maternal exposure to DBP induced autophagy through regulation of hedgehog signaling via overexpression of HhIP in foetal renal tubular cells, which may be essential for renal fibrosis development., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: This study focused on the oxidative stress effect of di-n-butyl phthalate (DBP) on development of the urinary system., Methods: We examined the mRNA expression of genital tubercle (GT) in control and DBP induced hypospadias group by Affymetrix Rat 230 2.0 Array. Real-time PCR and Western Blot were used to detect the protein and mRNA expression levels of inositol-1,4,5-triphate-receptor (IP3R) and epithelial-mesenchymal-transition (EMT)-related molecular markers, such as E-cadherin, β-Catenin, Snail, N-cadherin, in the GT of hypospadiac male rats and controls. The results of array were further confirmed in vitro. The changes of intracellular calcium concentration in urethral epithelial cells were detected by Fluo-3-AM before and after DBP treatment. The levels of reactive oxygen species (ROS) in urethral epithelial cells were measured by DCFH-DA with different concentrations of DBP (0, 1, 10, 100 μmol/L) treatment., Results: The mRNA expression profiles of GT in control and DBP induced hypospadias group showed high expression of IP3R and the abnormalities of EMT. Compared to the control group, the expression levels of IP3R, E-cadherin and β-Catenin increased at both the protein and mRNA levels. However the expression levels of Snail and N-cadherin decreased. The intracellular calcium concentration increased significantly after DBP treatment. The effect of DBP on urethral epithelial cells was linked to the generation of oxidative stress., Conclusion: DBP can influence the development of GT through its oxidative stress effect, which significantly increases the concentration of calcium and inhibits EMT in urethral epithelial cells, and block the fusion process of urethral groove, causing the occurrence of hypospadias. This study provides a new understanding of DBP's molecular mechanisms on hypospadias and may lead to new treatment strategies for the disease., (Copyright © 2020. Published by Elsevier Inc.)

Maternal exposure to di-n-butyl phthalate (DBP) induces hypospadias via regulation of autophagy in uroepithelial cells. Here, we use gene express analysis to explore the underlying molecular mechanisms. Pregnant rats received DBP orally at a dose of 750 mg/kg/day during gestational days 14-18. Gene expression analysis showed an increased expression of the hedgehog interacting protein (HhIP) gene. In DBP-induced hypospadiac male offspring, immunohistochemistry (IHC) staining and Western blot analysis confirmed increased expression of the HhIP protein and inhibited hedgehog signaling. in vitro experiments suggest the involvement of the reactive oxygen species (ROS)-HhIP-Gli1-autophagy axis in DBP-treated primary rat urethral epithelial cells. Taken together, our findings show that prenatal exposure to DBP induces abnormal hedgehog signaling and autophagy in uroepithelial cells that may play important roles in the development of hypospadias., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We previously demonstrated that maternal exposure to di-n-butyl phthalate (DBP) resulted in renal fibrosis in male offspring; however, the underlying mechanism governing this effect has not been thoroughly elucidated to date. We hypothesized that DBP exposure induces TGF-β expression and abnormal activation of epithelial-mesenchymal transition (EMT) in fibrotic kidneys. Pregnant rats received DBP orally at a dose of 850 mg/kg BW/day during gestational days 14-18. In the DBP-exposed group, immunohistochemistry (IHC) staining showed increased expression of TGF-β1 and EMT markers. In rat kidney tubular epithelial cells (NRK52E), ROS production increased expression levels of TGF-β1 and subsequently contributed to the induction of Snail1-mediated EMT. Notably, DBP exposure also promoted autophagy that downregulated TGF-β1. Taken together, our findings suggest that maternal exposure to DBP promotes EMT in tubular epithelial cells via upregulation of TGF-β1., (Copyright © 2018 Elsevier Inc. All rights reserved.)

This study was to determine the impact of maternal exposure to di-n-butyl phthalate (DBP) on renal development and fibrosis in adult offspring. Pregnant rats received DBP at a dose of 850 mg/kg BW/day by oral perfusion during gestational days 14-18. In DBP exposed newborn offspring, gross observation and histopathological examination revealed the dysplasia of kidney. The expression of genes related to renal development was also changed. In DBP exposed adult offspring, histopathological examination and Masson's trichrome staining revealed the pathological changes of renal fibrosis. Furthermore, higher expression levels of transforming growth factor- β (TGF-β) and alpha-smooth muscle actin (α-SMA) were also detected. In vitro studies reveal that DBP promoted the activation of NRK49F cells and G2/M arrest in NRK52E cells at a sublethal dose. The effect of DBP on these cell lines was linked to the generation of oxidative stress. In addition, DBP induced oxidative stress in both renal fibroblasts and tubular epithelial cells, whereas vitamin C ameliorated the changes caused by DBP. In conclusion, our results showed that prenatal exposure to DBP may generate oxidative stress in both renal fibroblasts and tubular epithelial cells, leading to kidney dysplasia and renal fibrosis.

This study was to compare the alterations of androgen cascades in di-n-butyl phthalate (DBP)-exposed male offspring without hypospadias (undeformed) versus those with hypospadias. To induce hypospadias in male offspring, pregnant rats received DBP via oral gavage at a dose of 750mg/kg BW/day during gestational days 14-18. The mRNA expression levels of genes downstream of the androgen signaling pathway, such as androgen receptor (AR) and Srd5a2, in testes of undeformed rat pups were similar to those in controls; in hypospadiac rat pups these levels were significantly lower than those of control pups. In contrast, both undeformed and hypospadiac rats had decreased serum testosterone levels, reduced mRNA expression of key enzymes in the androgen synthetic pathway in the testes, and ablated genes of developmental pathways, such as Shh, Bmp4, Fgf8, Fgf10 and Fgfr2, in the genital tubercle (GT) as compared to those in DBP-unexposed controls, albeit hypospadiac rats had a more severe decrement than those of undeformed rats. Although other possibilities cannot be excluded, our findings suggest that the relatively normal levels of testosterone-AR-Srd5a2 may contribute to the resistance to DBP toxicity in undeformed rats. In conclusion, our results showed a potential correlation between decreased testosterone levels, reduced mRNA expression of AR and Srd5a2 and the occurrence of hypospadias in male rat offspring prenatally exposed to DBP., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Anorectal malformations in combination with hypospadias (ARMs & hypospadias) are a type of complex congenital malformations. The underlying mechanisms of this deformity are largely unknown. In this study, we comprehensively characterized the dysplasia, histological malformations, and genetic changes of ARMs & hypospadias in male rats after maternal exposure to di-n-butyl phthalate (DBP) by gastric intubation at doses of 850mg/kg bw/day during GD11-15. On postnatal day 1, anatomical and histopathological analysis confirmed combined malformations of the genital tubercle (GT), terminal rectum (TR) and testes. DBP-induced dysplasia was also seen in the kidney, lung, spleen, heart and liver of ARMs & hypospadias male rats. Moreover, decreased levels of serum testosterone, as well as reduced expression of genes related to the androgen signaling pathway (Cyp11a1, Hsd3b, Scarb1, Star, AR, Srd5a2) were found in the testes of ARMs & hypospadias male rats after DBP exposure as compared to untreated controls. Further, decreased mRNA levels of Shh, Fgf10, Gli2, Gli3, Bmp4, Wnt5a, Hoxa13, Hoxd13, Fgfr2 and AR were observed in TR and GT in the ARMs & hypospadias group. These results provide evidence that prenatal exposure to DBP can lead to combined anorectal and urogenital malformations as well as dysplasia of the testes., (Copyright © 2016 Elsevier Inc. All rights reserved.)

This study was the first to investigate the genetic abnormalities and structural dysplasia of anorectal malformations (ARMs) in male rats induced by di(n-butyl) phthalate (DBP). DBP was administered to timed-pregnant rats to establish the ARM rat model. The incidence of ARMs in male offspring was 39.5%. In neonatal period, decreased body weight and anogenital distance were observed. The general image and histological analysis of male offspring confirmed the presence of ARMs. Anatomical examination of the ARM male rats revealed the dysplasia in solid organs (heart-lung, liver, spleen, and kidney). The decreases of serum testosterone concentration and androgen receptor expression in terminal rectum were indicative of the antiandrogenic effects of DBP. Moreover, significant decreased mRNA expressions of these androgen-related genes such as sonic hedgehog, Gli2, Gli3, bone morphogenetic protein 4, Wnt5a, Hoxa13, Hoxd13, fibroblast growth factor 10, and fibroblast growth factor receptor 2 were found in terminal rectum of the ARM male pubs. These results demonstrated that development of ARM rats was impaired by maternal exposure to DBP. The antiandrogenic effects of DBP disturbing the androgen-related signaling networks might play an important role in the occurrence of ARMs., (© 2014 Wiley Periodicals, Inc.)

Previous study have demonstrated that not only the anorectal development but also the general conditions of anorectal malformations (ARMs) male rats are severely affected by di-n-butyl phthalate (DBP) maternal exposure. However, the mechanisms underlying DBP-induced congenital defects remain elusive. Reportedly, Fgf10/Fgfr2 and androgen receptor (AR) are pivotal for the development of multiple organs. In this study, we therefore investigated the expression of Fgf10/Fgfr2 together with AR in the terminal rectum and multiple organs of ARM male rats induced by in utero exposure to DBP. DBP was administered to pregnant rats to establish the model and the incidence of ARMs in male offspring was 39.5%. On postnatal day(PND)1, the gross photograph and histopathological staining confirmed the abnormal manifestations in these organs of newborn ARMs. Decreased anogenital distance, body weight and serum testosterone level were observed in ARM male offspring. The reduced expression of Fgf10/Fgfr2 mRNA and protein was seen in terminal rectum and kidney, spleen, liver, heart in ARM male rats, whereas the reduced expression of AR was only observed in the kidney and terminal rectum. Our findings suggest the potential involvement of altered Fgf10/Fgfr2 signaling and AR in pathogenesis of local and systemic development defects in ARMs male rats induce by DBP., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Mounting evidence has indicated the crucial role of Wnt5a in the embryonic development including guts. However, the Wnt5a involvement in the process of anorectal malformations (ARMs) remains unclear. In this study, we examined the expression of Wnt5a during ARMs development in the offspring of di(n-butyl) phthalate (DBP)-treated pregnant rats. During the neonatal period, Wnt5a expression was evaluated in the terminal rectum of ARM offspring, non-ARM littermates and controls. Using real-time polymerase chain reaction (real-time PCR), western-blot analysis and immunohistochemistry approaches, we found a significant decrease of Wnt5a expression in DBP-induced ARMs rats. Collectively, our results demonstrate the aberrant expression of Wnt5a during anorectal development, which suggests that Wnt5a might be involved in DBP-induced ARMs.

The objectives of this study were to investigate the dysplasia, histological malformations, and genetic abnormalities in male rats induced by maternal exposure to di-n-butyl phthalate (DBP). Here we report novel findings concerning developmental abnormalities resulting from prenatal exposure to DBP, which leads to significant anorectal malformations (ARMs) in male rat offspring. The incidence of ARMs was 39.5% in male offspring and all abnormal pups were complicated with secondary megacolon. General images, histological analysis and anatomy examination confirmed the malformation. The development abnormalities such as decreased bodyweight (BW) and anogenital distance (AGD), shortened body lengths (with tail removed), as well as increased abdominal circumference were observed at different developmental stages of ARMs in male rat. The developmental abnormalities in both solid organs (brain, heart, liver, spleen, lung and kidney) and reproductive organs (testes and epididymis) of abnormal pubs on PND35 were also investigated. In addition, the serum testosterone (T) level of ARMs in male rats on PND1 was significantly lower than that of controls with accompanying reduced expression of androgen receptor (AR), sonic hedgehog (Shh) and bone morphogenetic protein 4 (Bmp4) mRNA from tissues of the terminal rectum. These results conclusively demonstrate for the first time that in utero exposure to DBP leads to an increased likelihood for the development of ARMs and subsequent complicating megacolon in male rat offspring., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)