Jun-Tao Jiang

Activated androgen receptor promotes bladder cancer metastasis via Slug mediated epithelial-mesenchymal transition

Androgen receptor (AR) has been indicated to be involved in bladder cancer progression. We showed androgen induced epithelial-mesenchymal transition (EMT) in AR-positive bladder cancer cells and promoted tumor metastasis in xenograft models. We subsequently identified that Slug was the mediator of EMT induced by androgen. Furthermore, upregulation of Slug was due to activation of Wnt/β-catenin signaling in response to androgen. Finally, expression of AR showed strong correlation with loss of E-cadherin, higher expression of Slug and nuclear accumulation of β-catenin in bladder tumor tissues. Taken together, our results suggest AR signaling promotes bladder cancer metastasis through Slug mediated EMT.

Molecular and toxicologic research in newborn hypospadiac male rats following in utero exposure to di-n-butyl phthalate (DBP)

The objective of this study was to first evaluate the developmental abnormalities and carry out the molecular analysis of external genitalia in newborn hypospadiac male rats induced by maternal exposure to di-n-butyl phthalate (DBP). Timed-pregnant rats were given DBP by gastric intubation at dose of 750 mg/kg body weight (bw)/day from gestation day (GD) 14 to GD18 to establish a hypospadiac rat model. The incidence of hypospadias was 46.67% in male offsprings. On postnatal day (PND) 7, at the newborn stage, decreased body weight and anogenital distance (AGD)/body weight ratio were observed in newborn hypospadiac male rats. The general image and transverse serial histological analysis of genitalia of newborn hypospadiac male rats confirmed the malformation. Autopsy analysis revealed development of reproductive organs (testes, genital tubercle (GT)), hollow organs (stomach, bladder), and solid organs (brain, heart, liver, spleen, lung, kidney, pancreas) in newborn hypospadiac male rats affected by DBP. Moreover, significantly decreased gene expression of important signaling molecules necessary for GT formation including sonic hedgehog signaling molecules (Shh and Ptched 1), bone morphogenetic proteins signaling molecules (Bmp4 and Bmp7), fibroblast growth factor signaling molecules (Fgf8, Fgf10 and Fgfr2), and the transforming growth factor-beta superfamily signaling molecules (TGF-beta1 and TGF-beta receptor III) were observed, for the first time, in the GT of newborn hypospadias induced by DBP. These results showed that the reproductive system and development conditions of newborn hypospadiac rats were damaged by DBP. These disturbed signaling pathways which orchestrating genital development might play an important role in the toxic process of DBP induced hypospadias.

Prenatal exposure to di-n-butyl phthalate induces anorectal malformations in male rat offspring

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.

Ureteral Reconstruction Using Autologous Tubular Grafts for the Management of Ureteral Strictures and Defects: An Experimental Study

Objective: To investigate whether the peritoneal cavity could function as a bioreactor to produce autologous tubular grafts for ureteral reconstruction in beagles. Materials and Methods: 8-Fr Silastic tubes were implanted into the peritoneal cavities of 6 female beagles. At 3 weeks, the tubes were harvested and the tubular tissue covering the tubes was gently everted. A segment 3 cm in length of the right mid-ureter, involving two thirds of its diameter, was removed parallel to the ureteral axis, leaving a third of the ureteral wall. A 5-Fr double-J stent was inserted into the ureter through the created defect, and two thirds of the graft were anastomosed to both edges of the ureteral defect. One third of the graft was overlapped with the retained normal ureter and anastomosed to the external surface of the lumens. Thus, the graft was partly encapsulated by the remainder of ureteral wall. The stent was maintained for 6 weeks and removed. Excretory urography was performed at 8 (n = 3) and 12 weeks (n = 3), postoperatively. Meanwhile, the neoureter was harvested and analyzed. The left ureter served as the control and a simple intubated ureterotomy was performed. Results: Histological analysis of the tubular tissue demonstrated transversely arranged myofibroblasts and an outer layer of mesothelium. The tissue was easily everted and transplanted as a ureteral graft. Eight weeks postoperatively, the neoureter demonstrated normal ureteral architecture, composed of multilayers of urothelium surrounded by smooth muscle bundles, which became increasingly organized with time. Excretory urography indicated no stenosis or hydronephrosis. Conclusions: These results show that autologous tubular tissue grown within the recipients’ peritoneal cavity can be used for ureteral reconstruction in the beagle model.

The role of androgen-induced growth factor (FGF8) on genital tubercle development in a hypospadiac male rat model of prenatal exposure to di-n-butyl phthalate.

Fibroblast growth factor 8 (FGF8) is an androgen-induced growth factor (AIGF) that is crucial for embryonic development. This study was developed to investigate the role of FGF8 in developmental abnormalities of the genital tubercle (GT) in hypospadiac male rats when prenatally exposed to di-n-butyl phthalate (DBP). DBP was administered to timed-pregnant rats to establish the hypospadiac rat model where the incidence of hypospadias in male offspring was 43.6%. On postnatal day (PND) 7, decreased mRNA and protein expression levels for androgen receptor (AR) and FGF8 were observed in the GT of hypospadiac rats. Decreased serum testosterone (T) levels were observed in groups displaying hypospadias, which was confirmed using histological analysis. Further anatomical examination using digital photography helped to reveal visualized expression of dysplasia in organs strongly associated with hypospadias. In addition, changes in body weight (BW) and anogenital distance (AGD) were recorded, showing definitive decreases. Collectively, these data clearly demonstrate an interaction between androgen and FGF8, which might play an important role in the occurrence of hypospadias and abnormal organ development induced by DBP.

Prenatal exposure to di-n-butyl phthalate (DBP) differentially alters androgen cascade in undeformed versus hypospadiac male rat offspring

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.

Maternal exposure to di-n-butyl phthalate (DBP) induces combined anorectal and urogenital malformations in male rat offspring.

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.

Reduced Fgf10/Fgfr2 and androgen receptor (AR) in anorectal malformations male rats induced by di-n-butyl phthalate (DBP): A study on the local and systemic toxicology of DBP.

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.

Genetic research and structural dysplasia assessment of anorectal malformations in neonatal male rats induced by di(n-butyl) phthalate.

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.

Maternal exposure to di-n-butyl phthalate (DBP) induces renal fibrosis in adult rat offspring

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 Massons 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.