Inhibition of androgen induces autophagy in benign prostate epithelial cells

Autophagy in benign prostatic hyperplasia: insights and therapeutic potential

Autophagy is a cellular homeostatic mechanism characterized by cyclic degradation. It plays an essential role in maintaining cellular quality and survival by eliminating dysfunctional cellular components. This process is pivotal in various pathophysiological processes. Benign prostatic hyperplasia (BPH) is a common urological disorder in middle-aged and elderly men. It frequently presents as lower urinary tract symptoms due to an increase in epithelial and stromal cells surrounding the prostatic urethra. The precise pathogenesis of BPH is complex. In recent years, research on autophagy in BPH has gained significant momentum, with accumulating evidence indicating its crucial role in the onset and progression of the disease. This review aims to outline the various roles of autophagy in BPH and elucidate potential therapeutic strategies targeting autophagy for managing BPH.

The role of autophagy in prostate cancer and prostatic diseases: a new therapeutic strategy

BACKGROUND

Autophagy is a well-conserved catabolic process that plays a key role in cell homeostasis. In the prostate, defective autophagy has been implicated in the genesis and progression of several pathological conditions.

AIM

The present review explored the autophagy pathway in prostate-related dysfunctions, focusing on prostate cancer (PCa), benign prostatic hyperplasia (BPH) and prostatitis.

RESULTS

Impaired autophagy activity has been shown in animal models of BPH and prostatitis. Moreover, autophagy activation by specific and non-specific drugs improved both conditions in pre-clinical studies. Conversely, the efficacy of autophagy inducers in PCa remains controversial, depending on intrinsic PCa characteristics and stage of progression. Intriguingly, autophagy inhibitors have shown beneficial effects in PCa suppression or even to overcome chemotherapy resistance. However, there are still open questions regarding the upstream mechanisms by which autophagy is deregulated in the prostate and the exact role of autophagy in PCa. The lack of specificity and increased toxicity associated with the currently autophagy inhibitors limits its use clinically, reflecting in reduced number of clinical data.

CONCLUSION

New therapeutic strategies to treat prostatic diseases involving new autophagy modulators, combination therapy and new drug formulations should be explored. Understanding the autophagy signaling in each prostatic disease is crucial to determine the best pharmacological approach.

Exploring the Enigma of 5-ARIs Resistance in Benign Prostatic Hyperplasia: Paving the Path for Personalized Medicine

PURPOSE OF REVIEW

Despite the widespread utilization of 5-alpha reductase inhibitors (5-ARIs) for managing benign prostatic hyperplasia (BPH), certain BPH patients exhibit unresponsiveness to 5-ARIs therapy. This paper provides a comprehensive overview of the current perspectives on the mechanisms of 5-ARIs resistance in BPH patients and integrates potential biomarkers and underlying therapeutic options for 5-ARIs resistance. These findings may facilitate the development of novel or optimize more effective treatment options, and promote personalized medicine for BPH.

RECENT FINDINGS

The pathways contributing to resistance against 5-ARIs in certain BPH patients encompass epigenetic modifications, shifts in hormone levels, autophagic processes, and variations in androgen receptor structures, and these pathways may ultimately be attributed to inflammation. Promisingly, novel biomarkers, including intravesical prostatic protrusion, inflammatory factors, and single nucleotide polymorphisms, may offer predictive insights into the responsiveness to 5-ARIs therapy, empowering physicians to fine-tune treatment strategies. Additionally, on the horizon, GV1001 and mTOR inhibitors have emerged as potential alternative therapeutic modalities for addressing BPH in the future. After extensive investigation into BPH's pathological processes and molecular landscape, it is now recognized that diverse pathophysiological mechanisms may contribute to different BPH subtypes among individuals. This insight necessitates the adoption of personalized treatment strategies, moving beyond the prevailing one-size-fits-all paradigm centered around 5-ARIs. The imperative for early identification of individuals prone to treatment resistance will drive physicians to proactively stratify risk and adapt treatment tactics in future practice. This personalized medicine approach marks a progression from the current standard treatment model, emerging as the future trajectory in BPH management.

Autophagy, a critical element in the aging male reproductive disorders and prostate cancer: a therapeutic point of view

Autophagy is a highly conserved, lysosome-dependent biological mechanism involved in the degradation and recycling of cellular components. There is growing evidence that autophagy is related to male reproductive biology, particularly spermatogenic and endocrinologic processes closely associated with male sexual and reproductive health. In recent decades, problems such as decreasing sperm count, erectile dysfunction, and infertility have worsened. In addition, reproductive health is closely related to overall health and comorbidity in aging men. In this review, we will outline the role of autophagy as a new player in aging male reproductive dysfunction and prostate cancer. We first provide an overview of the mechanisms of autophagy and its role in regulating male reproductive cells. We then focus on the link between autophagy and aging-related diseases. This is followed by a discussion of therapeutic strategies targeting autophagy before we end with limitations of current studies and suggestions for future developments in the field.

Decoding ceRNA regulatory network and autophagy-related genes in benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a common disease among aging males. We obtained BPH transcriptional signatures by high-throughput RNA sequencing analysis. Accordingly, we determined the differentially expressed RNAs (DERNAs) between BPH tissues and normal prostate tissues. WebGestalt and R package (clusterprofiler) was used to enrichment analysis. Clinical correlations were analyzed using Spearman's coefficient. TargetScan, ENCORI, miRNet, and miRDB databases were used to predict targets' relationships in ceRNA networks. Immunofluorescence staining and qRT-PCR analyses were performed to validate the findings. Microarray analysis of the datasets showed 369 DElncRNAs, 122 DEpseudogenes, 6 DEmiRNAs and 1358 DEmRNAs. DEmRNAs were particularly enriched in the autophagy-related pathways. Following the screening of DEmRNAs and autophagy-related genes (ARGs), 50 DEARGs were selected. MCODE analysis on Cytoscape was performed for the 50 DEARGs, and 3 hub genes (ATF4, XBP1, and PPP1R15A) were obtained. Spearman's correlation analysis showed that the mRNA expression of XBP1 correlated positively with age, total score, and storage score, but negatively with the maximum flow rate. Subsequently, the pseudogene/lncRNA- hsa-miR-222-3p-XBP1 pathway was identified. Our findings elucidate that the pseudogene/lncRNA-hsa-miR-222-3p-XBP1 pathway may play a regulatory role in the occurrence of BPH through autophagy.

Effect of Beclin-1 gene silencing on autophagy and apoptosis of the prostatic hyperplasia epithelial cells

OBJECTIVES

This study aims to explore the effect of silencing Beclin-1 gene on autophagy and apoptosis of Benign Prostatic Hyperplasia (BPH) (BPH-1) cells under the condition of Androgen Deprivation (AD) and Autophagy Inhibition (AI).

METHODS

Control group (BPH-1 group), empty carrier group (sh-RNA-BPH-1 group) and Beclin-1 silenced group (sh-Beclin1-BPH-1 group) were set. The Beclin-1 gene silencing efficiency was detected by RT-PCR and Western blot. Autophagic flux was monitored by GFP-LC3 cleavage assay and cell apoptosis was analyzed by flow cytometry. The protein expression levels of LC3, Caspase-3, PARP-1, Bcl-2, and Bax were detected by Western blot.

RESULTS

The transfection of sh-Beclin-1 obviously down-regulated the expression of Beclin-1 at both mRNA and protein levels. Under the conditions of AD and AI, silencing of Beclin-1 restrained the autophagy of BPH-1 cells, as evidenced by a decreased number of autophagosomes and down-regulation of LC3-II protein (p < 0.001). The results of flow cytometry showed that the apoptotic rate of sh-Beclin-1 group was elevated significantly compared to the other two groups (p < 0.01). Western blot results showed that silencing of Beclin-1 promoted 89 kd fragmentation of PARP-1 (p < 0.001) and Caspase-3 activation (p < 0.01). Moreover, silencing of Beclin-1 resulted in declined Bcl-2 and augmented Bax protein expression in BPH-1 cells (p < 0.01), which ultimately led to a decreased Bcl-2/Bax ratio.

CONCLUSIONS

The results indicated that the silencing of Beclin-1 gene hampered autophagy while activating apoptosis in BPH-1 cells. Thus, Beclin-1 may participate in an antagonistic relationship between autophagy and apoptosis in BPH.

Silencing of LLGL2 Suppresses the Estradiol-Induced BPH-1 Cell Proliferation through the Regulation of Autophagy

Lethal giant larvae (Lgl) is an apical-basal polarity gene first identified in Drosophila. LLGL2 is one of the mammalian homologs of Lgl. However, little is known about its function in the prostate. In this study, to explore the new role of LLGL2 in the prostate, we examined the proliferative activity of a BPH-1 cell line, a well-established model for the human prostate biology of benign prostatic hyperplasia (BPH). The expression of LLGL2 was dose-dependently increased in BPH-1 cells after treatment with 17β-estradiol (E2). Additionally, E2 treatment increased the proliferation of the BPH-1 cells. However, the knockdown of LLGL2 with siRNA significantly suppressed the proliferation of the E2-treated BPH-1 cells. Moreover, si-llgl2 treatment up-regulated the expression of LC-3B, ATG7, and p-beclin, which are known to play a pivotal role in autophagosome formation in E2-treated BPH-1 cells. Overexpression of LLGL2 was able to further prove these findings by showing the opposite results from the knockdown of LLGL2 in E2-treated BPH-1 cells. Collectively, our results suggest that LLGL2 is closely involved in the proliferation of prostate cells by regulating autophagosome formation. These results provide a better understanding of the mechanism involved in the effect of LLGL2 on prostate cell proliferation. LLGL2 might serve as a potential target in the diagnosis and/or treatment of human BPH.

Rauwolfia vomitoria extract suppresses benign prostatic hyperplasia by inducing autophagic apoptosis through endoplasmic reticulum stress

Background

The current drug treatments for benign prostatic hyperplasia (BPH) have negative side effects. Therefore, it is important to find effective alternative therapies with significantly fewer side effects. Our previous study revealed that Rauwolfia vomitoria (RWF) root bark extract reversed BPH development in a rat model. However, the molecular mechanism of its inhibitory effects on BPH remains largely unknown.

Methods

BPH-1 and WPMY-1 cell lines derived from BPH epithelial and prostatic stromal compartments were selected to investigate how RWF extract inhibits BPH in vitro by MTT and flow cytometry assays. Microarray, quantitative real-time PCR, immunoblotting, and GFP-LC3 immunofluorescence assays were performed to evaluate the effects of RWF extract on endoplasmic reticulum stress (ER stress) and autophagic apoptosis pathways in two cell lines. A human BPH ex vivo explant assay was also employed for validation.

Results

RWF extract treatment decreased cell viability and induced apoptotic cell death in both BPH-1 and WPMY-1 cells in a concentration-dependent manner with the increase of pro-apoptotic PCDC4 protein. RWF extract induced autophagy by enhancing the levels of autophagic genes (ULK2 and SQSTM1/p62) and the LC3II:LC3I ratio, with the increase of GFP-LC3 puncta. Moreover, RWF extract activated PERK- and ATF6-associated ER stress pathways by inducing the transcriptional levels of EIF2AK3/PERK, DDIT3/CHOP and ATF6, accompanied by the reduction of BiP protein level, but not its mRNA level. Another ER stress pathway was not induced by RWF extract, as manifested by the lack of XBP1 splicing. Pharmacological inhibition of autophagy by 3-methyladenine abrogated apoptosis but not ER stress; while inhibition of ER stress by 4-phenylbutyrate alleviated the induction of autophagy and apoptosis. In addition, pretreatments with either 3-methyladenine or 4-phenylbutyrate suppressed RWF extract-induced cytotoxicity. Notably, the inductions of PERK- and ATF6-related stress pathways and autophagic apoptosis were confirmed in a human BPH ex vivo explant.

Conclusions

Our data have demonstrated that RWF extract significantly suppressed the viabilities of BPH epithelial cells and BPH myofibroblasts by inducing apoptosis via upregulating ER stress and autophagy. These data indicate that RWF extract is a potential novel alternative therapeutic approach for BPH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03610-4.

Methylated CpG dinucleotides in the 5-α reductase 2 gene may explain finasteride resistance in benign prostatic enlargement patients

The inhibition of 5-α reductase type 2 (SRD5A2) by finasteride is commonly used for the management of urinary obstruction resulting from benign prostatic enlargement (BPE). Certain BPE patients showing no SRD5A2 protein expression are resistant to finasteride therapy. Our previous work showed that methylated cytosine-phosphate-guanine (CpG) islands in the SRD5A2 gene might account for the absence or reduction of SRD5A2 protein expression. Here, we found that the expression of the SRD5A2 protein was variable and that weak expression of the SRD5A2 protein (scored 0–100) occurred in 10.0% (4/40) of benign adult prostates. We showed that the expression of SRD5A2 was negatively correlated with DNA methyltransferase 1 (DNMT1) expression. In vitro SRD5A2-negative BPH-1 cells were resistant to finasteride treatment, and SRD5A2 was re-expressed in BPH-1 cells when SRD5A2 was demethylated by 5-Aza-2'-deoxycytidine (5-Aza-CdR) or N-phthalyl-L-tryptophan (RG108). Furthermore, we determined the exact methylation ratios of CpG dinucleotides in a CpG island of SRD5A2 through MassArray quantitative methylation analysis. Ten methylated CpG dinucleotides, including four CpG dinucleotides in the promoter and six CpG dinucleotides in the first exon, were found in a CpG island located from −400 bp to +600 bp in SRD5A2, which might lead to the silencing of SRD5A2 and the absence or reduction of SRD5A2 protein expression. Finasteride cannot exert a therapeutic effect on patients lacking SRD5A2, which may partially account for the resistance to finasteride observed in certain BPE patients.

Morphological and functional alterations of the prostate tissue during clinical progression in hormonally-naïve, hormonally-treated and castration-resistant patients with metastatic prostate cancer

Since commony used tools in oncological practice for the diagnosis of castration-resistent prostatic acinar adenocarcinoma are based on clinical criteria, such as castrate testosterone level, continuous rise in serum prostate-specific antigen, progression of preexisting disease or appearance of new metastases, it is important to identify reliable histopathological markers for the identification of this disease. Therefore, the aim of the present study was to determine the association between results from histological analysis, ultrastructural analysis and apoptosis in the prostate of patients with metastatic acinar prostatic adenocarcinoma (mPC). Patients were treated with androgen deprivation therapy (ADT), abiraterone acetate (Abi) therapy or received no treatment. Prostate tissue samples were divided into four groups as follows: i) Group 1, tissues from patients with benign prostatic hyperplasia (adenocarcinoma negative); ii) group 2, tissues from patients with metastatic hormone naïve prostate cancer; iii) group 3, tissues from patients with mPC treated with ADT; and iv) group 4, tissues from patients with metastatic castration-resistant prostate cancer treated with ADT and Abi. Immunohistochemical, terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling (TUNEL) and ultrastructural assays using light, fluorescence and transmission electron microscopy, respectively, were used to analyze prostate tissue samples. The results demonstrated that ADT and Abi therapy caused histological and ultrastructural changes in prostate tissues. In groups 3 and 4, benign and malignant tissues were affected by the hormonal therapy. Histologically, the malignant epithelium after ADT therapy in groups 3 and 4 presented with a loss of glandular architecture, nuclear and nucleolar shrinkage, chromatin condensation and cytoplasmic clearing. At the ultrastructural level, compact hypertrophic and hyperchromatic nuclei with numerous invaginations were observed in groups 2, 3 and 4. In addition, the incidence of abnormal mitochondria in malignant cells of these groups was high. Group 4 was characterized by the presence of malignant mesenchyme-like cells in the prostatic stroma, arranged in small groups surrounded by collagen fibrils. Furthermore, the cytoplasm of these cells contained filaments. A decrease in the number of apoptotic cells using TUNEL assays in the examined samples was observed with increasing disease progression. The findings from the present study suggest that the duration of treatment with ADT and progression of the disease were associated with apoptosis dysregulation.

The therapeutic effects of Stauntonia hexaphylla in benign prostate hyperplasia are mediated by the regulation of androgen receptors and 5α-reductase type 2

ETHNOPHARMACOLOGICAL RELEVANCE

Stauntonia hexaphylla (Lardizabalaceae, S. hexaphylla) is traditionally used as a folk remedy for alleviating fever and for its anti- inflammatory and analgesic properties. In Korea and China, S. hexaphylla has been used as a traditional medicine that acts as diuretic and analgesic. S. hexaphylla has also been reported to inhibit osteoporosis and aldose reductase activity.

AIM OF THE STUDY

The study aimed to evaluate the therapeutic effects of an extract of S. hexaphylla on testosterone induced benign prostate hyperplasia (BPH) models and to observe its mechanism of action.

MATERIALS AND METHODS

To induce a BPH model in vitro and in vivo, a testosterone-treated LNCaP cell line and Sprague Dawley (SD) rats were used, respectively. Androgen receptors (ARs) and prostate-specific antigens (PSA), which are typical BPH-related proteins, were evaluated using western blotting. Prostate weights and dihydrotestosterone (DHT) levels were measured in vivo, and histopathology of the prostate examined using hematoxylin and eosin staining. Proliferating cell nuclear antigen (PCNA) and 5α-reductase type 2 were also evaluated via immunohistochemistry (IHC). In addition, TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining and LC3 staining of IHC were performed to evaluate apoptosis and autophagy.

RESULTS

S. hexaphylla reduced prostates weights and the thickness of prostate epithelial cells. In vivo and in vitro, PSA and ARs were downregulated following S. hexaphylla treatment. The S. hexaphylla extracts also reduced DHT and 5α-reductase type 2 expression. In addition, the expression of PCNA was reduced, and in the TUNEL staining and IHC of LC3, the number of positive cells was increased in the groups treated with S. hexaphylla.

CONCLUSIONS

It was observed that extracts of S. hexaphylla inhibited both 5α -reductase type 2 and ARs. The results indicate that the use of S. hexaphylla extract in BPH is probably beneficial through 5α-reductase inhibition and α-adrenergic receptor blockade. In addition, apoptosis and autophagy were induced, and PCNA was downregulated after S. hexaphylla treatment. Therefore, it can be concluded that S. hexaphylla has a therapeutic effect on BPH.

Measurement of autophagy flux in benign prostatic hyperplasia in vitro

Background

Recent studies have suggested a novel therapeutic strategy for treatment of benign prostatic hyperplasia (BPH) via modulation of autophagy. However, it is not clear whether autophagy induction or inhibition can render better therapeutic efficacy for BPH treatment because autophagy activation in BPH tissue is not precisely known and still contradictory. The purpose of this study was to examine the levels of autophagy in BPH tissue cells.

Methods

We have analyzed and compared autophagic flux which is defined as a measure of autophagic degradation activity in two human prostate epithelial cell lines, RWPE-1 (normal prostate) and BPH-1 (BPH) using LC3-II turnover assay, to clarify the levels of autophagy in BPH.

Results

The in vitro autophagy flux assays showed that autophagy flux was significantly decreased in BPH-1 cell lines compared with RWPE-1 cells under all three conditions of using the original (~62%), the exchanged (~46%), and the same media (Hank's balanced salt solution (HBSS), ~40%), and these results were similar to those seen in the prostate of testosterone-induced BPH rats (~50%) (P < 0.05).

Conclusion

It is suggested that defective autophagy, which is decreased autophagy flux in the prostate gland, may be implicated in BPH, and activating autophagy flux of the prostate with BPH may be used as a potential therapeutic target for treating and alleviating BPH disease.

5-ARI induces autophagy of prostate epithelial cells through suppressing IGF-1 expression in prostate fibroblasts

Objectives

5α‐reductase inhibitor (5‐ARI) is a commonly used medicine in the treatment of lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). Our study mainly focuses on the mechanism of BPH development after 5ARI treatment.

Materials and Methods

Prostate specimens from patients were collected. Insulin‐like growth factor 1 (IGF‐1), Beclin‐1, LC3 levels, was analysed by immunohistochemistry. The role IGF‐1 on autophagic flux in prostate epithelial cells was studied. Additionally, effect of autophagy on recombinant grafts consisting of prostate stromal and epithelial cells in nude mice was investigated.

Results

We demonstrated that IGF‐1 expression is down‐regulated in prostate fibroblasts after long‐term 5‐ARI application. A decrease in IGF‐1 levels was found to activate autophagic flux through the mTOR pathway in prostate epithelial cells, while the inhibition of IGF‐1 receptor function induced autophagy in prostate epithelial cells. In addition, we revealed that blocking autophagic flux initiation can reduce the volume of recombinant grafts in vivo. Finally, our findings suggest that long‐term 5‐ARI application reduces IGF‐1 secretion by prostatic stromal cells, thereby inducing autophagy of prostatic epithelial cells, which is one of the mechanisms underlying BPH pathogenesis and progression.

Conclusions

Focusing on the autophagy induced by low levels of IGF‐1 in prostatic epithelial cells, after elucidating AR signalling impairment of prostate stromal cells, might provide a novel strategy for the treatment and prevention of BPH development.

Deregulation of ATG9A by impaired AR signaling induces autophagy in prostate stromal fibroblasts and promotes BPH progression

The activation of androgen receptor (AR) signaling plays an essential role in both prostate stromal cells and epithelial cells during the development of benign prostatic hyperplasia (BPH). Here we demonstrated that androgen ablation after 5α-reductase inhibitor (5-ARI) treatment induced autophagy in prostate stromal fibroblasts inhibiting cell apoptosis. In addition, we found that ATG9A expression was increased after androgen ablation, which facilitated autophagic flux development. Knockdown of ATG9A not only inhibited autophagy notably in prostate stromal fibroblasts, but also reduced the volumes of prostate stromal fibroblast and epithelial cell recombinant grafts in nude mice. In conclusion, our findings suggested that ATG9A upregulation after long-term 5-ARI treatment constitutes a possible mechanism of BPH progression. Thus, combined treatment with 5-ARI and autophagy inhibitory agents would reduce the risk of BPH progression.

Crosstalk between apoptosis and autophagy in prostate epithelial cells under androgen deprivation

The present study investigated the molecular mechanism of apoptosis and autophagy in prostate epithelial cells under androgen deprivation (AD). BPH-1 cells were divided into four groups as follows: Control (Cont), AD, autophagy inhibition (AI) and AD + AI groups. Cells in the four groups were treated accordingly, and the level of apoptosis was subsequently measured via flow cytometry. The expression of the microtubule-associated proteins 1A/1B light chain 3 (LC3), caspase-3, poly (ADP-ribose) polymerase 1 (PARP-1) and Beclin-1 proteins of BPH-1 cells was detected at different time points following culture in androgen-deprived medium. Western blotting revealed that the basal levels of the LC3-II protein were detected at 0 h. At 4 h, LC3-II was significantly increased compared with 0 h (P<0.05). Beginning at 20 h, the expression level of the LC3-II protein decreased significantly (P<0.05). Western blotting revealed that beginning at 24 h, the expression level of the PARP-1 protein decreased significantly (P<0.001) and the cleavage fragments of the PARP-1 protein appeared. These results further imply that autophagy serves a cell protective function by mutual inhibition with apoptosis in BPH-1 cells in the removal of androgen conditions. Furthermore, the fragments of the cleaved Beclin-1 protein appeared as 35 and 37 kDa bands. Flow cytometry analysis demonstrated that the rate of cell apoptosis in the AD, AI and AD + AI groups was significantly increased compared with the Cont group (P<0.01). Compared with the AD or the AI groups individually, the rate of cell apoptosis in the AD + AI group was significantly increased (P<0.001). These findings suggest that in the early stage of AD, autophagy has a compensatory function in the cell, whereas in the whole process, autophagy and apoptosis share a mutual antagonism. The Beclin-1-C protein fragment contributed positive feedback to the process of apoptosis, which may be a potential mechanism of AD therapy. Therefore, AD and AI exhibit a synergistic effect to further improve the level of apoptosis.

Correlation between Cholinergic Innervation, Autophagy, and Etiopathology of Benign Prostatic Hyperplasia

BACKGROUND

Whether cholinergic innervations and/or autophagy have a role in the etiopathology of benign prostatic hyperplasia (BPH) is still unknown. This study aimed to investigate the role of cholinergic innervation and autophagy in the etiopathology of BPH.

METHODS

Male, 13-week-old spontaneous hypertension rats (spontaneous BPH animal model) were divided into three groups: an experimental group (EG, n = 24), a control group (CG, n = 24), and a normal control group (NC, n = 10). The EG animals were intragastrically injected with tolterodine (3.5 mg/kg, twice a day), CG animals were intragastrically injected with physiological saline, and the NC animals did not receive any treatment. Rats were sacrificed every 4 weeks, and the prostatic gross morphological changes, wet weight/body weight (ww/bw), dry weight/wet weight (dw/ww), histological changes, ultrastructural changes, and LC3 immunohistochemistry were continuously observed and compared.

RESULTS

The gross morphological and ww/bw changes in the three groups were similar at every stage. The dw/ww (mg/mg) values of the EG at week 17, 21, 25, and 29 were 0.1478 ± 0.0034, 0.1653 ± 0.0036, 0.1668 ± 0.0045, and 0.1755 ± 0.0034, respectively, and the CG values were 0.1511 ± 0.0029, 0.1734 ± 0.0020, 0.1837 ± 0.0052, and 0.1968 ± 0.0045, respectively. The difference between EG and CG for dw/ww showed statistical significance after 21 weeks of age (week 21: P= 0.016, week 25: P= 0.008, and week 29: P= 0.001). Both EG and CG, prostatic glandular epithelial cell proliferation, and secretory function improved with age, but in EG, these improvements were slower than those in CG, and all the differences were statistically significant after 21 weeks. An increasing number of autophagosomes in the prostatic glandular cell cytoplasm, attenuation of LC3-I immunohistochemical staining, enhancement of LC3-II staining, and the ratio of LC3-II/LC3-I staining were all progressive in both groups, but the rate of change in EG was faster than that in CG, and these differences gained statistical significance after 25 weeks. Comparisons with regard to the above indexes between CG and NC showed no statistical significance at any stage.

CONCLUSIONS

Cholinergic innervations and activation of autophagy appear to have important functions in the etiopathology of BPH. Drug-mediated blockade of cholinergic innervations could delay the physiopathology processes. Moreover, overactivation of autophagy may also play an important role in this delay.

Di-n-butyl phthalate induced hypospadias relates to autophagy in genital tubercle via the PI3K/Akt/mTOR pathway

OBJECTIVE

To explore the mechanisms of hypospadias induced by in utero exposure to din-butyl phthalate (DBP).

METHODS

Timed-pregnant Sprague-Dawley rats were administered 750 mg/kg of DBP by gavage from GD (gestation days) 13 to GD 18, whereas control group received corn oil. Genital tubercles (GTs) and blood samples were collected from male fetuses on GD 19. The serum testosterone concentration, apoptosis activity, autophagosomes and their related proteins (light chain 3 (LC3-I, LC3-II) ), and sequestosomes (SQSTM1/p62) in the GTs were then measured. Protein expression of protein kinase B (Akt), Beclin 1, phosphorylated Akt (p-Akt), p-S6, and phosphorylated mammalian target of rapamycin (p-mTOR) in the GTs were analyzed by Western blotting.

RESULTS

The incidence of hypospadias induced by DBP was 43.64% in male fetuses. The GT volume and GT volume/body weight of fetuses were significantly reduced in the hypospadias and the non-hypospadias groups. Apoptotic cell number was significantly decreased in the GTs of the hypospadias group, but unchanged in the non-hyposadias group. The ratio of LC3-II/LC3-I was higher in the GTs from DBP exposed fetuses compared to the control group. The ratio of LC3-II/LC3-I in the GTs was higher in the hypospadias group than in the non-hypospadias group. The number of autophagosomes was increased in the GTs of the hypospadias group. Protein expression of p-S6, p-mTOR, and p-Akt were significantly decreased in the GTs of hypospadiac rats.

CONCLUSIONS

DBP-induced hypospadias might be associated with apoptosis and autophagy mediated by the PI3K/Akt/mTOR signaling pathway in the GT.