PPARγ: a molecular link between systemic metabolic disease and benign prostate hyperplasia

Transcriptomic analysis of benign prostatic hyperplasia identifies critical pathways in prostatic overgrowth and 5-alpha reductase inhibitor resistance

BACKGROUND

The medical therapy of prostatic symptoms (MTOPS) trial randomized men with symptoms of benign prostatic hyperplasia (BPH) and followed response of treatment with a 5α-reductase inhibitor (5ARI), an alpha-adrenergic receptor antagonist (α-blocker), the combination of 5ARI and α-blocker or no medical therapy (none). Medical therapy reduced risk of clinical progression by 66% but the reasons for nonresponse or loss of therapeutic response in some patients remains unresolved. Our previous work showed that prostatic glucocorticoid levels are increased in 5ARI-treated patients and that glucocorticoids can increased branching of prostate epithelia in vitro. To understand the transcriptomic changes associated with 5ARI treatment, we performed bulk RNA sequencing of BPH and control samples from patients who received 5ARI versus those that did not. Deconvolution analysis was performed to estimate cellular composition. Bulk RNA sequencing was also performed on control versus glucocorticoid-treated prostate epithelia in 3D culture to determine underlying transcriptomic changes associated with branching morphogenesis.

METHOD

Surgical BPH (S-BPH) tissue was defined as benign prostatic tissue collected from the transition zone (TZ) of patients who failed medical therapy while control tissue termed Incidental BPH (I-BPH) was obtained from the TZ of men undergoing radical prostatectomy for low-volume/grade prostatic adenocarcinoma confined to the peripheral zone. S-BPH patients were divided into four subgroups: men on no medical therapy (none: n = 7), α-blocker alone (n = 10), 5ARI alone (n = 6) or combination therapy (α-blocker and 5ARI: n = 7). Control I-BPH tissue was from men on no medical therapy (none: n = 8) or on α-blocker (n = 6). A human prostatic cell line in 3D culture that buds and branches was used to identify genes involved in early prostatic growth. Snap-frozen prostatic tissue taken at the time of surgery and 3D organoids were used for RNA-seq analysis. Bulk RNAseq data were deconvoluted using CIBERSORTx. Differentially expressed genes (DEG) that were statistically significant among S-BPH, I-BPH, and during budding and branching of organoids were used for pathway analysis.

RESULTS

Transcriptomic analysis between S-BPH (n = 30) and I-BPH (n = 14) using a twofold cutoff (p < 0.05) identified 377 DEG (termed BPH377) and a cutoff < 0.05 identified 3377 DEG (termed BPH3377). Within the S-BPH, the subgroups none and α-blocker were compared to patients on 5ARI to reveal 361 DEG (termed 5ARI361) that were significantly changed. Deconvolution analysis of bulk RNA seq data with a human prostate single cell data set demonstrated increased levels of mast cells, NK cells, interstitial fibroblasts, and prostate luminal cells in S-BPH versus I-BPH. Glucocorticoid (GC)-induced budding and branching of benign prostatic cells in 3D culture was compared to control organoids to identify early events in prostatic morphogenesis. GC induced 369 DEG (termed GC359) in 3D culture. STRING analysis divided the large datasets into 20-80 genes centered around a hub. In general, biological processes induced in BPH supported growth and differentiation such as chromatin modification and DNA repair, transcription, cytoskeleton, mitochondrial electron transport, ubiquitination, protein folding, and cholesterol synthesis. Identified signaling pathways were pooled to create a list of DEG that fell into seven hubs/clusters. The hub gene centrality was used to name the network including AP-1, interleukin (IL)-6, NOTCH1 and NOTCH3, NEO1, IL-13, and HDAC/KDM. All hubs showed connections to inflammation, chromatin structure, and development. The same approach was applied to 5ARI361 giving multiple networks, but the EGF and sonic hedgehog (SHH) hub was of particular interest as a developmental pathway. The BPH3377, 5ARI363, and GC359 lists were compared and 67 significantly changed DEG were identified. Common genes to the 3D culture included an IL-6 hub that connected to genes identified in BPH hubs that defined AP1, IL-6, NOTCH, NEO1, IL-13, and HDAC/KDM.

CONCLUSIONS

Reduction analysis of BPH and 3D organoid culture uncovered networks previously identified in prostatic development as being reinitiated in BPH. Identification of these pathways provides insight into the failure of medical therapy for BPH and new therapeutic targets for BPH/LUTS.

Effects of the CB1 receptor antagonists AM6545 and AM4113 on metabolic syndrome-induced prostatic hyperplasia in rats

Metabolic syndrome (MetS) is a combination of metabolic disorders that can predispose individuals to benign prostatic hyperplasia (BPH). The inhibition of the cannabinoid 1 (CB1) receptor has been used to treat metabolic disorders in animal models. This study reports the use of a peripherally restricted CB1 antagonist (AM6545) and a neutral CB1 antagonist (AM4113) to improve MetS-related BPH in rats. Animals were divided into three control groups to receive either a normal rodent diet, AM6545, or AM4113. MetS was induced in the fourth, fifth, and sixth groups using a concentrated fructose solution and high-salt diet delivered as food pellets for eight weeks. The fifth and sixth groups were further given AM6545 or AM4113 for additional four weeks. Body and prostate weights were measured and prostate sections were stained with hematoxylin eosin. Cyclin D1, markers of oxidative stress and inflammation, and levels of the endocannabinoids were recorded. BPH in rats with MetS was confirmed through increased prostate weight and index, as well as histopathology. Treatment with either AM6545 or AM4113 significantly decreased prostate weight, improved prostate histology, and reduced cyclin D1 expression compared with the MetS group. Groups treated with CB1 antagonists experienced reduced lipid peroxidation, recovered glutathione depletion, restored catalase activity, and had lower inflammatory markers interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α). MetS rats treated with either AM6545 or AM4113 showed reduced concentrations of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in the prostate compared with the MetS group. In conclusion, the CB1 antagonists AM6545 and AM4113 protect against MetS-induced BPH through their anti-proliferative, antioxidant, and anti-inflammatory effects.

Glucocorticoids are induced while dihydrotestosterone levels are suppressed in 5-alpha reductase inhibitor treated human benign prostate hyperplasia patients

BACKGROUND

The development of benign prostatic hyperplasia (BPH) and medication-refractory lower urinary tract symptoms (LUTS) remain poorly understood. This study attempted to characterize the pathways associated with failure of medical therapy for BPH/LUTS.

METHODS

Transitional zone tissue levels of cholesterol and steroids were measured in patients who failed medical therapy for BPH/LUTS and controls. Prostatic gene expression was measured using qPCR and BPH cells were used in organoid culture to study prostatic branching.

RESULTS

BPH patients on 5-α-reductase inhibitor (5ARI) showed low levels of tissue dihydrotestosterone (DHT), increased levels of steroid 5-α-reductase type II (SRD5A2), and diminished levels of androgen receptor (AR) target genes, prostate-specific antigen (PSA), and transmembrane serine protease 2 (TMPRSS2). 5ARI raised prostatic tissue levels of glucocorticoids (GC), whereas alpha-adrenergic receptor antagonists (α-blockers) did not. Nuclear localization of GR in prostatic epithelium and stroma appeared in all patient samples. Treatment of four BPH organoid cell lines with dexamethasone, a synthetic GC, resulted in budding and branching.

CONCLUSIONS

After failure of medical therapy for BPH/LUTS, 5ARI therapy continued to inhibit androgenesis but a 5ARI-induced pathway increased tissue levels of GC not seen in patients on α-blockers. GC stimulation of organoids indicated that the GC receptors are a trigger for controlling growth of prostate glands. A 5ARI-induced pathway revealed GC activation can serve as a master regulator of prostatic branching and growth.

High degree of prostate related LUTS in a prospective cross-sectional community study in Ghana (Mamprobi)

Background

Changing voiding patterns, volume and frequency, may sometimes be mistaken for anxiety, stress or increase in fluid consumption. In the aging male population, the commencement of lower urinary tract symptoms (LUTS) may be silent and perceived as “normal” and unrelated to Benign prostatic enlargement (BPE). The purpose of the study was to determine the prevalence of apparently “silent LUTS” (perceived asymptomatic LUTS) in men in a Ghanaian Community as well as its underlying risk factors.

Methods

One hundred and eleven (111) men (40–70 years) were recruited from a community in Ghana. The International Prostate Symptoms Score (IPSS) questionnaire (administered in the local language and English) and ultrasonographic imaging of the prostate volume (PV) were utlized to collect data. IPSS score >7 plus PV > 30 cm³ was definitive of lower urinary tract symptoms. Eighty-one (81) participants were classified “LUTS Negative” (LN) and 30, “LUTS Positive” (LP). Risk factors i.e., cholesterol (CHOL), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), very low-density lipoprotein (VLDL), coronary risk (CR), BMI and Blood Pressure were also determined.

Results

The prevalence of LUTS using only IPSS definition alone was 42.3%. However, IPSS in combination with Prostate Volume gave a prevalence of 27.0%. LN subjects had enlarged prostate (41.98%) and LP, 100%. Quality of life (QoL) was better in the LUTS Negative than LUTS Positive group (p < 0.001). In the univariant analysis coronary risk, triglyceride and VLDL contributed to LUTS (p = 0.023, 0.22, 0.22, respectively). In a multivariant analysis HDL-C (p = 0.027), BMI (p = 0.047) and triglyceride (p = 0.019) significantly contributed to LUTS.

Conclusions

The prevalence of LUTS (42.3%) is high. Components of Metabolic Syndrome- HDL-C, BMI, and coronary risk were associated with LUTS. This emphasizes the need for community education.

Upregulated PPARG2 facilitates interaction with demethylated AKAP12 gene promoter and suppresses proliferation in prostate cancer

Prostate cancer (PCA) is one of the most common male genitourinary tumors. However, the molecular mechanisms involved in the occurrence and progression of PCA have not been fully clarified. The present study aimed to investigate the biological function and molecular mechanism of the nuclear receptor peroxisome proliferator-activated receptor gamma 2 (PPARG2) in PCA. Our results revealed that PPARG2 was downregulated in PCA, and overexpression of PPARG2 inhibited cell migration, colony formation, invasion and induced cell cycle arrest of PCA cells in vitro. In addition, PPARG2 overexpression modulated the activation of the Akt signaling pathway, as well as inhibited tumor growth in vivo. Moreover, mechanistic analysis revealed that PPARG2 overexpression induced increased expression level of miR-200b-3p, which targeted 3′ UTR of the downstream targets DNMT3A/3B, and facilitated interaction with demethylated AKAP12 gene promoter and suppressed cell proliferation in PCA. Our findings provided the first evidence for a novel PPARG2-AKAP12 axis mediated epigenetic regulatory network. The study identified a molecular mechanism involving an epigenetic modification that could be possibly targeted as an antitumoral strategy against prostate cancer.

Peroxisome proliferator-activated receptor gamma expression along the male genital system and its role in male fertility

Peroxisome proliferator-activated receptor gamma (PPARγ) acts as a ligand activated transcription factor and regulates processes, such as energy homeostasis, cell proliferation and differentiation. PPARγ binds to DNA as a heterodimer with retinoid X receptor and it is activated by polyunsaturated fatty acids and fatty acid derivatives, such as prostaglandins. In addition, the insulin-sensitizing thiazolidinediones, such as rosiglitazone, are potent and specific activators of PPARγ. PPARγ is present along the hypothalamic-pituitary-testis axis and in the testis, where low levels in Leydig cells and higher levels in Sertoli cells as well as in germ cells have been found. High amounts of PPARγ were reported in the normal epididymis and in the prostate, but the receptor was almost undetectable in the seminal vesicles. Interestingly, in the human and in pig, PPARγ protein is highly expressed in ejaculated spermatozoa, suggesting a possible role of PPARγ signaling in the regulation of sperm biology. This implies that both natural and synthetic PPARγ ligands may act directly on sperm improving its performance. Given the close link between energy balance and reproduction, activation of PPARγ may have promising metabolic implications in male reproductive functions. In this review, we first describe PPARγ expression in different compartments of the male reproductive axis. Subsequently, we discuss the role of PPARγ in both physiological and several pathological conditions related to the male fertility.

Animal models of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) and associated lower urinary tract symptoms are common clinical concerns that affect aging men all over the world. The underlying molecular and cellular mechanisms remain elusive. Over the past few years, a number of animal models of BPH, including spontaneous model, BPH-induction model, xenograft model, metabolic syndrome model, mechanical obstruction model, and transgenic model, have been established that may provide useful tools to fill these critical knowledge gaps. In this review, we therefore outlined the present status quo for animal models of BPH, comparing the pros and cons with respect to their ability to mimic the etiological, histological, and clinical hallmarks of BPH and discussed their applicability for future research.

Insulin exacerbated high glucose-induced epithelial-mesenchymal transition in prostatic epithelial cells BPH-1 and prostate cancer cells PC-3 via MEK/ERK signaling pathway

As two most common progressive diseases of aging, type 2 diabetes mellitus (T2DM) and benign prostatic hyperplasia (BPH) were all characterized by endocrine and metabolic disorders. Here, our clinical study showed that there were significant differences in fasting blood glucose (FBG), fasting insulin (FINS), insulin resistance index (HOMA-IR) and prostate volume (PV) between simple BPH patients and BPH complicated with T2DM patients. Further analysis showed that HOMA-IR was positively correlated with PV in BPH complicated with T2DM patients. The in vitro experiment results showed that high glucose (HG) promoted EMT process in a glucose-dependent manner in human prostate hyperplasia cells (BPH-1) and prostate cancer cells (PC-3), and this pathological process was exacerbated by co-culture with insulin. Mechanistically, insulin-induced exacerbation of EMT was depended on the activation of MEK/ERK signaling pathway, and we suggested that insulin and its analogs should be used very carefully for the clinical antihyperglycemic treatment of BPH complicated with T2DM patients.

Hyperglycemia and T Cell infiltration are associated with stromal and epithelial prostatic hyperplasia in the nonobese diabetic mouse

BACKGROUND

Prostatic inflammation and various proinflammatory systemic comorbidities, such as diabetes and obesity are associated with human benign prostatic hyperplasia (BPH). There is a paucity of in vivo models reflecting specific aspects of BPH pathogenesis. Our aim was to investigate the nonobese diabetic (NOD) mouse as a potential model for subsequent intervention studies.

MATERIALS AND METHODS

We used the NOD mouse, a model of autoimmune inflammation leading to type 1 diabetes to examine the effects of systemic inflammation and diabetes on the prostate. We assessed changes in prostatic histology, infiltrating leukocytes, and gene expression associated with aging and diabetic status.

RESULTS

Both stromal expansion and epithelial hyperplasia were observed in the prostates. Regardless of diabetic status, the degree of prostatic hyperplasia varied. Local inflammation was associated with a more severe prostatic phenotype in both diabetic and nondiabetic mice. Testicular atrophy was noted in diabetic mice, but prostate glands showed persistent focal cell proliferation. In addition, a prostatic intraepithelial neoplasia (PIN)-like phenotype was seen in several diabetic animals with an associated increase in c-Myc and MMP-2 expression. To examine changes in gene and cytokine expression we performed microarray and cytokine array analysis comparing the prostates of diabetic and nondiabetic animals. Microarray analysis revealed several differentially expressed genes including CCL3, CCL12, and TNFS10. Cytokine array analysis revealed increased expression of cytokines and proteases such as LDLR, IL28 A/B, and MMP-2 in diabetic mice.

CONCLUSION

Overall, NOD mice provide a model to examine the effects of hyperglycemia and chronic inflammation on the prostate, demonstrating relevance to some of the mechanisms present underlying BPH and potentially the initiation of prostate cancer.

Classification of prostate cancer using a protease activity nanosensor library

Improved biomarkers are needed for prostate cancer, as the current gold standards have poor predictive value. Tests for circulating prostate-specific antigen (PSA) levels are susceptible to various noncancer comorbidities in the prostate and do not provide prognostic information, whereas physical biopsies are invasive, must be performed repeatedly, and only sample a fraction of the prostate. Injectable biosensors may provide a new paradigm for prostate cancer biomarkers by querying the status of the prostate via a noninvasive readout. Proteases are an important class of enzymes that play a role in every hallmark of cancer; their activities could be leveraged as biomarkers. We identified a panel of prostate cancer proteases through transcriptomic and proteomic analysis. Using this panel, we developed a nanosensor library that measures protease activity in vitro using fluorescence and in vivo using urinary readouts. In xenograft mouse models, we applied this nanosensor library to classify aggressive prostate cancer and to select predictive substrates. Last, we coformulated a subset of nanosensors with integrin-targeting ligands to increase sensitivity. These targeted nanosensors robustly classified prostate cancer aggressiveness and outperformed PSA. This activity-based nanosensor library could be useful throughout clinical management of prostate cancer, with both diagnostic and prognostic utility.

The Lipid Side of Bone Marrow Adipocytes: How Tumor Cells Adapt and Survive in Bone

PURPOSE OF REVIEW

Bone marrow adipocytes have emerged in recent years as key contributors to metastatic progression in bone. In this review, we focus specifically on their role as the suppliers of lipids and discuss pro-survival pathways that are closely linked to lipid metabolism, affected by the adipocyte-tumor cell interactions, and likely impacting the ability of the tumor cell to thrive in bone marrow space and evade therapy.

RECENT FINDINGS

The combined in silico, pre-clinical, and clinical evidence shows that in adipocyte-rich tissues such as bone marrow, tumor cells rely on exogenous lipids for regulation of cellular energetics and adaptation to harsh metabolic conditions of the metastatic niche. Adipocyte-supplied lipids have a potential to alter the cell's metabolic decisions by regulating glycolysis and respiration, fatty acid oxidation, lipid desaturation, and PPAR signaling. The downstream effects of lipid signaling on mitochondrial homeostasis ultimately control life vs. death decisions, providing a mechanism for gaining survival advantage and reduced sensitivity to treatment. There is a need for future research directed towards identifying the key metabolic and signaling pathways that regulate tumor dependence on exogenous lipids and consequently drive the pro-survival behavior in the bone marrow niche.

Metformin: an antiproliferative agent and methylation regulator in treating prostatic disease?

Existing drugs that have been used in clinical practice for other purposes can prove useful for reutilization, since much of the safety profile and pharmacokinetics have been completed. Therefore, the drugs can enter clinical practice for a variety of causes with less regulatory burden. Metformin may prove to be such a drug; it may have a role in other diseases, besides the management of diabetes. In this perspective, we provide our findings and understanding of metformin as an alternative way to treat urological abnormal proliferation. We propose the potential mechanisms into two hallmarks: direct antiproliferative function via insulin-like growth factor (IGF) signaling pathway and epigenetic modulating via adjusting DNA methylation. These specific hallmarks may ultimately contribute to a better understanding of metformin in treating prostatic diseases.

A genetic variant near GATA3 implicated in inherited susceptibility and etiology of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS)

BACKGROUND

Benign prostatic hyperplasia (BPH) and associated lower urinary tract symptoms (LUTS) are common conditions. Little is known about their etiologies except that studies have suggested a substantial heritable component. Our objective is to provide a comprehensive, genome-wide evaluation of inherited risks and possible mechanisms of etiology in BPH.

METHODS

We performed a three-stage, genome-wide association study (GWAS) of men from three independent populations, the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial, the CLUE II cohort, and a Finnish hospital-based population. DNA samples were genotyped using the Illumina HumanOmniExpress BeadChip in REDUCE and CLUE II, and using the Sequenom iPLEX system for the confirmation stage in the Finnish population. A logistic regression model was used to evaluate the association between each SNP and BPH/LUTS.

RESULTS

Fourteen SNPs reached P < 5.0 × 10^-4 in the meta-analysis of the two GWASs (CLUE II and REDUCE). A total of 773 SNPs were chosen for the confirmation step in the Finish cohort. Only one SNP (rs17144046) located ∼489 kb downstream of GATA3 remained significant after correction for multiple testing (P < 6.5 × 10^-5 ). This SNP marginally reached the GWAS significance level after performing a meta-analysis of the three stages (P_-meta  = 8.89 × 10^-7 ). Expression quantitative trait loci (eQTL) analyses showed that the risk allele (G) of rs17144046 was significantly associated with increased expression of GATA3 (P = 0.017). Reported studies indicated a close correlation between GATA3 and BPH pathogenesis and progression.

CONCLUSIONS

Rs17144046 located near GATA3 was significantly associated with BPH/LUTS in three independent populations, but did not reach a stringent GWAS significance level. Genetic variants of GATA3 may play a role in the inherited susceptibility and etiology of BPH/LUTS. Further research in this area is needed.

Atorvastatin attenuates testosterone-induced benign prostatic hyperplasia in rats: role of peroxisome proliferator-activated receptor-γ and cyclo-oxygenase-2

Diabetes and obesity have been reported to alter sex steroid hormone metabolism. In this study, an attempt was made to investigate the protective effect of atorvastatin (ATR) in combination with celecoxib (CEL) or pioglitazone (PIO) on testosterone-induced BPH in rats. Male Wistar rats (200-250 g) were randomly divided into nine groups (n = 8) and orally treated as follows for 28 consecutive days: group 1: vehicle control (10 mL/kg); group 2: vehicle testosterone (10 mL/kg); groups 3 - 5: ATR (0.5, 2.5, and 5 mg/kg, respectively); group 6: CEL (20 mg/kg); group 7: PIO (20 mg/kg); and groups 8-9: ATR 0.5 mg/kg, and 15 min later, animals were given CEL (20 mg/kg) or PIO (20 mg/kg), respectively. One hour post-treatment, animals in groups 2-9 were given testosterone propionate (3 mg/kg, s.c.). Twenty-four hours after last treatment on day 28, blood was collected for serum testosterone and prostate-specific antigen (PSA) analysis. Prostate was harvested for biochemical and histological assays. Subcutaneous injection of testosterone increased serum levels of testosterone and PSA which was ameliorated by pretreatments of rat with ATR, celecoxib, or pioglitazone. Similarly, testosterone-induced increase in MDA and reduction in the activity of GSH, superoxide dismutase (SOD), and catalase were attenuated by ATR. Conversely, celecoxib or pioglitazone treatment failed to affect the activity of antioxidant enzymes. The histology of the prostate showed significant improvement in prostatic cells of ATR, celecoxib, or pioglitazone treated. Findings from the study showed that atorvastatin attenuated testosterone-induced BPH. Moreover, synergistic effect was observed when atorvastatin was combined with celecoxib.

Review of Prostate Anatomy and Embryology and the Etiology of Benign Prostatic Hyperplasia

Prostate development follows a common pattern between species and depends on the actions of androgens to induce and support ductal branching morphogenesis of buds emerging from the urogenital sinus. The human prostate has a compact zonal anatomy immediately surrounding the urethra and below the urinary bladder. Rodents have a lobular prostate with lobes radiating away from the urethra. The human prostate is the site of benign hyperplasia, prostate cancer, and prostatitis. The rodent prostate has little naturally occurring disease. Rodents can be used to model aspects of human benign hyperplasia, but care should be taken in data interpretation and extrapolation to the human condition.

NF-κB and androgen receptor variant 7 induce expression of SRD5A isoforms and confer 5ARI resistance

BACKGROUND

Benign prostatic hyperplasia (BPH) is treated with 5α-reductase inhibitors (5ARI). These drugs inhibit the conversion of testosterone to dihydrotestosterone resulting in apoptosis and prostate shrinkage. Most patients initially respond to 5ARIs; however, failure is common especially in inflamed prostates, and often results in surgery. This communication examines a link between activation of NF-κB and increased expression of SRD5A2 as a potential mechanism by which patients fail 5ARI therapy.

METHODS

Tissue was collected from "Surgical" patients, treated specifically for lower urinary tract symptoms secondary to advanced BPH; and, cancer free transition zone from "Incidental" patients treated for low grade, localized peripheral zone prostate cancer. Clinical, molecular and histopathological profiles were analyzed. Human prostatic stromal and epithelial cell lines were genetically modified to regulate NF-κB activity, androgen receptor (AR) full length (AR-FL), and AR variant 7 (AR-V7) expression.

RESULTS

SRD5A2 is upregulated in advanced BPH. SRD5A2 was significantly associated with prostate volume determined by Transrectal Ultrasound (TRUS), and with more severe lower urinary tract symptoms (LUTS) determined by American Urological Association Symptom Score (AUASS). Synthesis of androgens was seen in cells in which NF-κB was activated. AR-FL and AR-V7 expression increased SRD5A2 expression while forced activation of NF-κB increased all three SRD5A isoforms. Knockdown of SRD5A2 in the epithelial cells resulted in significant reduction in proliferation, AR target gene expression, and response to testosterone (T). In tissue recombinants, canonical NF-κB activation in prostatic epithelium elevated all three SRD5A isoforms and resulted in in vivo growth under castrated conditions.

CONCLUSION

Increased BPH severity in patients correlates with SRD5A2 expression. We demonstrate that NF-κB and AR-V7 upregulate SRD5A expression providing a mechanism to explain failure of 5ARI therapy in BPH patients. Prostate 76:1004-1018, 2016. © 2016 Wiley Periodicals, Inc.

Protective potential of epigallocatechin-3-gallate against benign prostatic hyperplasia in metabolic syndrome rats

Epigallocatechin-3-gallate (EGCG) is a major catechin in green tea with functions of antioxidant, anti-proliferative, anti-inflammatory and attenuating metabolic syndrome. In this study, rat model of benign prostatic hyperplasia (BPH) accompanied with metabolic syndrome was induced by fed on high-fat diet for 12 weeks combined with testosterone injection (10mg/kg/d) from 9th to 12th weeks. EGCG was orally given from 9th to 12th weeks. Finally, the levels of glucose, total cholesterol, triglyceride, prostate weight, insulin-like growth factors (IGFs), inflammatory cytokines, antioxidant enzymes, and prostatic expression of IGF binding protein-3 (IGFBP-3) and peroxisome proliferator activated receptors (PPARs) were evaluated. It was found that EGCG significantly decreased the levels of glucose, total cholesterol, triglyceride, IGFs, and inflammatory cytokines, normalized the activities of antioxidant enzymes, as well as increased the prostatic expression of IGFBP-3 and PPARs. These results indicated that EGCG was able to exert anti-BPH activities in metabolic syndrome rats.

The Association Between Metabolic Syndrome and Characteristics of Benign Prostatic Hyperplasia: A Systematic Review and Meta-Analysis

The purpose of this systematic review was to examine the association of metabolic syndrome (MS) with measures of benign prostatic hyperplasia (BPH) including prostate growth rate, prostate volume, International Prostate Symptom Score (IPSS), prostate-specific antigen (PSA) level, and maximal flow rate.Medline, Cochrane CENTRAL, EMBASE, CBM, and Google Scholar databases were searched until March 23, 2015 using combinations of the keywords benign prostate hyperplasia/BPH, metabolic syndrome, total prostate volume, prostate growth rate, prostate specific antigen, International Prostate Symptom Score/IPSS, maximal flow rate. Cohort or case-control studies of patients with BPH and MS that reported quantitative outcomes were included. The pooled mean differences of the outcome measures were compared between patients with and without MS.A total of 158 potentially relevant studies were identified, and 8 were included in the meta-analysis. The 8 studies included in the meta-analysis contained a total of 3093 BPH patients, wherein 1241 had MS and 1852 did not have MS. BPH patients with MS had a significantly higher prostate growth rate (pooled mean difference = 0.67 mL/y, P < 0.001) and larger prostate volume (pooled mean difference = 6.8 mL, P = 0.010) than the BPH patients without MS. There was no significant difference in IPSS score (pooled mean difference = 1.58, P = 0.202) or maximal flow rate (pooled mean difference = -1.41 mL/s, P = .345) between BPH patients with and without MS. A borderline nonsignificant difference in PSA (pooled mean difference = 0.24 ng/mL, P = 0.056) was noted between BPH patients with and without MS.The results of this meta-analysis are consistent with literature indicating that BPH patients with MS have a higher prostate growth rate and larger prostate volume than those without MS; however, further study is necessary to determine the association of BPH and metabolic disorder elements and the potential risk of disease progression in BPH patients with MS.

Parturition dysfunction in obesity: time to target the pathobiology

Over a third of women of childbearing age in the United States are obese, and during pregnancy they are at increased risk for delayed labor onset and slow labor progress that often results in unplanned cesarean delivery. The biology behind this dysfunctional parturition is not well understood. Studies of obesity-induced changes in parturition physiology may facilitate approaches to optimize labor in obese women. In this review, we summarize known and proposed biologic effects of obesity on labor preparation, contraction/synchronization, and endurance, drawing on both clinical observation and experimental data. We present evidence from human and animal studies of interactions between obesity and parturition signaling in all elements of the birth process, including: delayed cervical ripening, prostaglandin insensitivity, amniotic membrane strengthening, decreased myometrial oxytocin receptor expression, decreased myocyte action potential initiation and contractility, decreased myocyte gap junction formation, and impaired myocyte neutralization of reactive oxygen species. We found convincing clinical data on the effect of obesity on labor initiation and successful delivery, but few studies on the underlying pathobiology. We suggest research opportunities and therapeutic interventions based on plausible biologic mechanisms.

Effect of obesity and hyperglycemia on benign prostatic hyperplasia in elderly patients with newly diagnosed type 2 diabetes

PURPOSE

To investigate the relationship between blood glucose levels, age, body mass index (BMI), and benign prostatic hyperplasia (BPH) in patients with newly diagnosed type 2 diabetes.

METHODS

A total of 141 BPH patients with newly diagnosed type 2 diabetes participated in this study. Their glucose level, international prostate symptom score (IPSS), prostate volume (PV), and maximum urinary flow rate (Qmax) were determined and analyzed.

RESULTS

Compared to patients in 60-69 years of age, those in 70-79 years of age had higher IPSS and PV values (11.10±2.68 vs. 16.09±2.64, respectively; P<0.01; 38.67±4.65 vs. 44.76±2.84, respectively; P<0.01) as did patients ≥80 y (11.10±2.68 vs. 19.87±3.35, respectively; P<0.01; 38.67±4.65 vs. 51.38±3.74, respectively; P<0.01). The Qmax was lower in the ≥80 y group compared to the 60-69 y group (7.91±2.13 vs. 13.50±1.75, respectively; P<0.01). IPSS, PV, and insulin resistance index (HOMA-IR) were higher in patients with a BMI ≥28 kg/m(2) group as compared to those with a BMI <24 kg/m(2) group. IPSS and PV values were higher in patients with HbA1c levels ≥6.5% than in those with HbA1c<6.5% (16.30±3.31 vs. 9.87±1.07, respectively; P<0.01; 45.69±3.97 vs. 36.64±3.30, respectively; P<0.01), and the Qmax was lower (10.61±1.98 vs. 14.40±0.82, respectively; P<0.01).

CONCLUSIONS

Aging, obesity, high glucose level, and insulin resistance increase the risk of BPH progression in elderly patients with newly diagnosed type 2 diabetes. Managing body weight and lowering the level of glycosylated hemoglobin may slow the progression of BPH in people with type 2 diabetes.

The effect of pomegranate fruit extract on testosterone-induced BPH in rats

BACKGROUND

Benign prostatic hyperplasia (BPH) affects many men after the age of 50 years. Inflammation and oxidative stress along with apoptotic changes are thought to play an important role in the pathology of BPH. Pomegranate contains a variety of polyphenolic compounds that have been studied in a medley of diseases for their anti-oxidant, anti-inflammatory and pro-apoptotic properties. Therefore, this study examined the effect of Pomegranate Fruit Extract (PFE) on the development of BPH using a testosterone-induced BPH model in rats.

METHODS

A total of 48 rats were randomly divided into six groups of eight, one group served as the control, BPH was induced by testosterone 3 mg/kg S.C. daily in four groups, three of them received PFE by oral gavage daily at doses of 25, 50, and 100 mg/kg respectively, while one group received PFE at a dose of 50 mg/kg without induction of BPH.

RESULTS

PFE at a dose of 100 mg/kg was the most effective in decreasing testosterone-induced increase in prostate weight, prostate weight/body weight ratio, and PAP levels by 30.8%, 55%, and 68% respectively and in preventing the accompanying histological changes. In the BPH model, testosterone significantly decreased GSH, SOD, and CAT to 0.45, 0.64, and 0.88 of the control group values respectively, and significantly increased MDA by >6-fold. In combination with testosterone, PFE dosed at 100 mg/kg significantly increased GSH, SOD, and CAT to 0.83, 0.92, and 0.93 of the control group values respectively, whereas MDA was significantly decreased by 72% compared with the testosterone treated group. In addition to this, at the range of doses studied, PFE lowered COX-II, iNOS, Ki-67 expression, and increased apoptotic index.

CONCLUSION

The current findings elucidate the effectiveness of PFE in preventing testosterone-induced BPH in rats. This could be attributed, at least partly, to its anti-oxidant, anti-inflammatory, and pro-apoptotic properties.

Expression of Peroxisome Proliferator Activated Receptor gamma in Prostatic Adenocarcinoma

Peroxisome proliferator-activated receptor gamma (PPAR-γ), a ligand-activated transcription factor has been investigated as the target for cancer treatment as well as metabolic disorders. Recent studies have demonstrated that PPAR-γ ligands are anti-tumorigenic in prostate cancer due to anti-proliferative and pro-differentiation effects. The aim of this study was to validate PPAR-γ expression in malignant and benign prostate tissues by immunohistochemistry and quantitative real-time polymerase chain reaction (PCR). A total of 730 prostatic adenocarcinomas (PCAs) including 63 whole sections from radical prostatectomy specimens and tissue microarrays containing 667 PCAs were subject to immunostaining for two PPAR-γ antibodies. Twenty-five benign prostate tissues and PCAs were selected for investigating mRNA expression by quantitative real-time PCR. 10.7% of PCAs (78/730) showed cytoplasmic immunoreactivity of PPAR-γ and no nuclear immunoreactivity was noted in PCAs. Most benign prostatic glands showed negative immunoreactivity of PPAR-γ except for variable weak cytoplasmic staining in some glands. Nuclear immunoreactivity of PPAR-γ was noted some central zone and verumontanum mucosal epithelium. The constitutive PPAR-γ mRNA showed significantly lower level in PCAs compared to that in the benign tissues. There was no difference of PPAR-γ mRNA expression between low (≤7) and high (>7) Gleason score groups. There was no association of PPAR-γ mRNA level or cytoplasmic immunostaining with Gleason grade or pathologic stage. Our study supported the evidence of extra-nuclear localization and nongenomic actions of PPAR-γ. Further studies are needed to assess the functional role of PPAR-γ and to validate its therapeutic implication in prostate cancer.

Urine chemokines indicate pathogenic association of obesity with BPH/LUTS

OBJECTIVES

High prevalence of lower urinary tract symptoms (LUTS) consistent with benign prostate hyperplasia (BPH) is associated with obesity and prostatic inflammation. Here, we investigated whether chemokines associated with obesity and prostatic inflammation can be measured in normally voided urine of BPH/LUTS patients to demonstrate the mechanistic association between obesity and BPH/LUTS.

METHODS

Frozen urine specimens of BPH/LUTS patients enrolled in the Nashville Men's Health Study were sent for blinded analysis to University of Pittsburgh. Thirty patients were blocked by their AUA-SI (>7 or ≤7) and prostatic enlargement (<40, 40-60, >60 cc). Clinical parameters including age, prostate size, and medications were derived from chart review. CXC chemokines (CXCL-1, CXCL-8, and CXCL-10), CC chemokines (CCL2 and CCL3), and sIL-1ra were measured in thawed urine using Luminex™ xMAP(®) technology and ELISA for NGF.

RESULTS

Urinary CCL2 levels were several fold higher compared with the other six proteins, of which CCL3 was detectable in less than one-fourth of patients. Urine levels of sIL-1ra and CXCL-8 were significantly associated with increasing BMI and waist circumference in BPH patients. CXCL-8 showed a marginal association with overall AUA-SI scores, as well as obstructive (p = 0.08) symptom subscores. Prostate volume was inversely and marginally associated with urinary CXCL-10 (p = 0.09).

CONCLUSIONS

Urine levels of CXCL-8, CXCL-10, and sIL-1ra were associated with varying degrees with LUTS severity, prostate size, and obesity, respectively. These findings in urine are consistent with past studies of chemokine levels from expressed prostatic secretions and demonstrate the potential of noninvasively measured chemokine in urine to objectively classify BPH/LUTS patients.

Association of variants in genes related to the immune response and obesity with BPH in CLUE II

BACKGROUND

Chronic inflammation and obesity may contribute to the genesis or progression of BPH and BPH-associated lower urinary tract symptoms (LUTS). The influence of variants in genes related to these states on BPH has not been studied extensively. Thus, we evaluated the association of 17 single-nucleotide polymorphisms (SNPs) in immune response genes (IL1B, IL6, IL8, IL10, TNF, CRP, TLR4 and RNASEL) and genes involved in obesity, including insulin regulation (LEP, ADIPOQ, PPARG and TCF7L2), with BPH.

METHODS

BPH cases (N = 568) and age-frequency matched controls (N=568) were selected from among adult male CLUE II cohort participants who responded in 2000 to a mailed questionnaire. BPH was defined as BPH surgery, use of BPH medications or symptomatic BPH (American Urological Association Symptom Index Score ⩾ 15). Controls were men who had not had BPH surgery, did not use BPH medications and whose symptom score was ⩽ 7. Age-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression.

RESULTS

None of the candidate SNPs was statistically significantly associated with BPH. However, we could not rule out possible weak associations for CRP rs1205 (1082C>T), ADIPOQ rs1501299 (276C>A), PPARG rs1801282 (-49C>G) and TCF7L2 rs7903146 (47833T>C). After summing risk alleles, men with ⩾ 4 had an increased BPH risk compared with those with ⩽ 1 (OR, 1.78; 95% CI, 1.10-2.89; P(trend) = 0.006).

CONCLUSIONS

SNPs in genes related to immune response and obesity, especially in combination, may be associated with BPH.

Thiazolidinedione and Metformin Use and the Risk of Benign Prostate Hyperplasia in Veterans with Diabetes Mellitus

BACKGROUND

Chronic inflammation is important in the development of benign prostatic hyperplasia (BPH) and certain oral antidiabetic medications have anti-inflammatory properties. The purpose of this study was to determine if use of thiazolidinediones or metformin was associated with a reduced risk of requiring medical or surgical treatment for BPH compared to sulfonylureas among diabetic men.

METHODS

We constructed a retrospective cohort of 192,457 male veterans newly prescribed either rosiglitazone, pioglitazone, metformin, or a sulfonylurea. We used Cox proportional hazard regression to assess the association between thiazolidinedione or metformin use and the risk of requiring medical or surgical treatment for BPH compared to sulfonylurea use. New BPH treatment was defined by either a new prescription for a α-1 blocker or 5α-reductase inhibitors or a surgical procedure indicated for severe BPH.

RESULTS

In 259,995 person-years of follow up we identified 14,690 new treatments for BPH. After adjusting for covariates including age, HbA1c, and body mass index, we found no association between rosiglitazone (adjusted hazard ratio [aHR] 1.02, 95% CI 0.86, 1.20), pioglitazone (aHR 0.79, 95% CI 0.45, 1.38), or metformin use (aHR 0.99, 95% CI 0.94, 1.03) and risk of new medical or surgical treatment for BPH compared to sulfonylureas. Analyses ignoring prescriptions for non-selective α-1 blockers (terazosin, doxazosin, prazosin) from our BPH case definition (n = 11,079), yielded similar results.

CONCLUSIONS

In this large cohort, we observed no association between the use of thiazolidinediones or metformin and new medical or surgical treatment for BPH compared to sulfonylureas.

Leptin influences estrogen metabolism and accelerates prostate cell proliferation

AIM

The present study was designed to investigate the effect of leptin on estrogen metabolism in prostatic cells.

MAIN METHODS

Malignant (PC-3) and benign (BPH-1) human prostate cells were treated with 17-β-hydroxyestradiol (1 μM) alone or in combination with leptin (0.4, 4, 40 ng/ml) for 72 h. Cell proliferation assay, immunocytochemical staining of estrogen receptor (ER), liquid chromatography-tandem mass spectrometry method (LC-MS) and semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) were used.

KEY FINDINGS

Cell proliferation assay demonstrated that leptin caused significant growth potentiation in both cells. Immunocytochemical staining showed that leptin significantly increased the expression of ER-α and decreased that of ER-β in PC-3 cells. LC-MS method revealed that leptin increased the concentration 4-hydroxyestrone and/or decreased that of 2-methoxyestradiol, 4-methoxyestradiol and 2-methoxyestrone. Interestingly, RT-PCR showed that leptin significantly up-regulated the expression of aromatase and cytochrome P450 1B1 (CYP1B1) enzymes; however down-regulated the expression of catechol-o-methyltransferase (COMT) enzyme.

SIGNIFICANCE

These data indicate that leptin-induced proliferative effect in prostate cells might be partly attributed to estrogen metabolism. Thus, leptin might be a novel target for therapeutic intervention in prostatic disorders.

Bone marrow adipocytes promote tumor growth in bone via FABP4-dependent mechanisms

Incidence of skeletal metastases and death from prostate cancer greatly increases with age and obesity, conditions which increase marrow adiposity. Bone marrow adipocytes are metabolically active components of bone metastatic niche that modulate the function of neighboring cells; yet the mechanisms of their involvement in tumor behavior in bone have not been explored. In this study, using experimental models of intraosseous tumor growth and diet-induced obesity, we demonstrate the promoting effects of marrow fat on growth and progression of skeletal prostate tumors. We reveal that exposure to lipids supplied by marrow adipocytes induces expression of lipid chaperone FABP4, pro-inflammatory interleukin IL-1β, and oxidative stress protein HMOX-1 in metastatic tumor cells and stimulates their growth and invasiveness. We show that FABP4 is highly overexpressed in prostate skeletal tumors from obese mice and in bone metastasis samples from prostate cancer patients. In addition, we provide results suggestive of bi-directional interaction between FABP4 and PPARγ pathways that may be driving aggressive tumor cell behavior in bone. Together, our data provide evidence for functional relationship between bone marrow adiposity and metastatic prostate cancers and unravel the FABP4/IL-1β axis as a potential therapeutic target for this presently incurable disease.

Prostatic protective nature of the flavonoid-rich fraction from Cyclosorus acuminatus on carrageenan-induced non-bacterial prostatitis in rat

Abstract Context: Cyclosorus acuminatus (Houtt.) Nakai (Thelypteridaceae) is used in Chinese traditional medicine for inflammation and pyretic stranguria. Objective: This study investigates the prostatic protective potential of the flavonoid-rich [(2S)-5,7,5'-trihydroxyflavanone glycosides] fraction from C. acuminatus (FCA). Materials and methods: Chronic non-bacterial prostatitis (CNBP) was induced by injecting 20 μl of 1% carrageenan into the rat prostate. Subsequently, FCA (150 or 300 mg/kg/d) was orally given once a day for 4 weeks. Finally, the levels of proinflammatory cytokines and the prostatic expression of peroxisome proliferator activated receptor-γ (PPAR-γ) were evaluated. Results: Treatment with 300 mg/kg/d FCA ameliorated the carrageenan-induced higher prostatic index (PI) state and proinflammatory cytokines levels (NFκB from 2602 ± 588 to 1348 ± 300 pg/ml, TNF-α from 151.6 ± 10.4 to 126.0 ± 3.52 pg/ml, IL-1β from 153.7 ± 14.8 to 63.9 ± 6.7 pg/ml, COX-2 from 313.3 ± 16.5 to 263.1 ± 15.1 pg/ml, PGE from 1532 ± 130 to 864 ± 126 pg/ml, NOS from 33.7 ± 3.0 to 23.6 ± 1.6 U/mg protein, and NO from 40.3 ± 2.9 to 27.1 ± 2.9 μmol/g protein) as well as regulated the prostatic expression of PPAR-γ (increased about 3.50-fold) when compared to the rat model of prostatitis. Discussion and conclusion: FCA could exert a prostatic protective response via modulating the prostatic expression of PPAR-γ and eventually alleviating the NFκB dependent inflammatory response.

Association of metabolic syndrome and benign prostatic hyperplasia in Chinese patients of different age decades

OBJECTIVES

To evaluate the relationship between metabolic syndrome (MetS) and annual prostate growth rates in Chinese patients of different age decades with benign prostatic hyperplasia (BPH).

METHODS

We retrospectively analyzed the clinical data obtained from 1,052 Chinese men with BPH. Overnight fasting venous blood specimens were collected and serum levels of prostate-specific antigen, fasting blood glucose, high-density lipoprotein cholesterol, total cholesterol and triglyceride were recorded. We divided age into four groups: 50 ≤ age ≤ 60, 60 < age ≤ 70, 70 < age ≤ 80 and 80 < age ≤ 90. Pearson's correlation coefficient was used to test the linearity of the relationships between each of the MetS components and prostate volume and annual prostate growth rates generally and in different age decades.

RESULTS

The median total prostate volume (69.01 ml) and median annual prostate growth rate (1.92 ml/year) were significantly higher in the MetS group compared with the non-MetS group (57.26 ml and 1.23 ml/year). Significant positive correlations were also found in total prostate volume and different age decades, while negative correlations were seen in annual prostate growth rate and different age decades.

CONCLUSIONS

MetS is associated with an increased risk of total volume and annual prostate growth rate in BPH patients of different age decades.

Mechanisms of synergism between antagonists of growth hormone-releasing hormone and antagonists of luteinizing hormone-releasing hormone in shrinking experimental benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) affects aging men. Combined therapy with antagonists of growth hormone-releasing hormone (GHRH) and of luteinizing hormone-releasing hormone (LHRH or GnRH) induces prostate shrinkage in rat models. We investigated the mechanisms of action of this combination on cell cycle traverse and expression of prostatic genes.

METHODS

Effects of GHRH antagonist, JMR-132 (40 µg/day), the LHRH antagonist, cetrorelix (0.625 mg/kg), and their combination were evaluated on testosterone-induced benign prostatic hyperplasia in male Wistar rats. Influence of JMR-132, cetrorelix, and their combinations on cell viability was assessed by MTS assay in BPH-1 human prostate epithelial cells and WPMY-1 normal prostate stromal cells. Cell cycle was analyzed by laser flow cytometry. Real-time PCR arrays were performed.

RESULTS

The combination of antagonists caused marked shrinkage of rat prostate (29.5%). In vitro, JMR-132 plus cetrorelix (both 5µM) produced synergistic (57.4%) inhibition of growth of BPH-1 cells, but a lesser inhibition (46%) of WPMY-1 cells. Co-treatment of with JMR-132 plus cetrorelix induced a significant increase of BPH-1 cells blocked in S-phase plus cells with lower G0 /G1 and G2 /M DNA content. Significant changes in expression of >40 gene transcripts related to growth factors, inflammatory cytokines, and signal transduction were identified.

CONCLUSIONS

GHRH antagonist and LHRH antagonist combination potentiates rat prostate weight reduction and synergistically inhibits of growth of BPH-1 leading to cell cycle arrest in S-phase. These effects were lesser in normal stromal prostate cell line, WPMY-1. Our findings suggest that GHRH antagonists could be useful for BPH therapy, possibly in combination with LHRH antagonists.

Extensive alternative splicing of the repressor element silencing transcription factor linked to cancer

The repressor element silencing transcription factor (REST) is a coordinate transcriptional and epigenetic regulator which functions as a tumor suppressor or an oncogene depending on cellular context, and a truncated splice variant REST4 has been linked to various types of cancer. We performed a comprehensive analysis of alternative splicing (AS) of REST by rapid amplification of cDNA ends and PCR amplification of cDNAs from various tissues and cell lines with specific primers. We identified 8 novel alternative exons including an alternate last exon which doubles the REST gene boundary, along with numerous 5'/3' splice sites and ends in the constitutive exons. With the combination of various splicing patterns (e.g. exon skipping and alternative usage of the first and last exons) that are predictive of altered REST activity, at least 45 alternatively spliced variants of coding and non-coding mRNA were expressed in a species- and cell-type/tissue-specific manner with individual differences. By examining the repertoire of REST pre-mRNA splicing in 27 patients with kidney, liver and lung cancer, we found that all patients without exception showed differential expression of various REST splice variants between paired tumor and adjacent normal tissues, with striking cell-type/tissue and individual differences. Moreover, we revealed that exon 3 skipping, which causes no frame shift but loss of a domain essential for nuclear translocation, was affected by pioglitazone, a highly selective activator of the peroxisome proliferator-activated receptor gamma (PPARγ) which contributes to cell differentiation and tumorigenesis besides its metabolic actions. Accordingly, this study demonstrates an extensive AS of REST pre-mRNA which redefines REST gene boundary and structure, along with a general but differential link between REST pre-mRNA splicing and various types of cancer. These findings advance our understanding of the complex, context-dependent regulation of REST gene expression and function, and provide potential biomarkers and therapeutic targets for cancer.

Cholesterol and male fertility: what about orphans and adopted?

The link between cholesterol homeostasis and male fertility has been clearly suggested in patients who suffer from hyperlipidemia and metabolic syndrome. This has been confirmed by the generation of several transgenic mouse models or in animals fed with high cholesterol diet. Next to the alteration of the endocrine signaling pathways through steroid receptors (androgen and estrogen receptors); "orphan" and "adopted" nuclear receptors, such as the Liver X Receptors (LXRs), the Proliferating Peroxisomal Activated Receptors (PPARs) or the Liver Receptor Homolog-1 (LRH-1), have been involved in this cross-talk. These transcription factors show distinct expression patterns in the male genital tract, explaining the large panel of phenotypes observed in transgenic male mice and highlighting the importance of lipid homesostasis and the complexity of the molecular pathways involved. Increasing our knowledge of the roles of these nuclear receptors in male germ cell differentiation could help in proposing new approaches to either treat infertile men or define new strategies for contraception.

PPARγ isoforms differentially regulate metabolic networks to mediate mouse prostatic epithelial differentiation

Recent observations indicate prostatic diseases are comorbidities of systemic metabolic dysfunction. These discoveries revealed fundamental questions regarding the nature of prostate metabolism. We previously showed that prostate-specific ablation of PPARγ in mice resulted in tumorigenesis and active autophagy. Here, we demonstrate control of overlapping and distinct aspects of prostate epithelial metabolism by ectopic expression of individual PPARγ isoforms in PPARγ knockout prostate epithelial cells. Expression and activation of either PPARγ 1 or 2 reduced de novo lipogenesis and oxidative stress and mediated a switch from glucose to fatty acid oxidation through regulation of genes including Pdk4, Fabp4, Lpl, Acot1 and Cd36. Differential effects of PPARγ isoforms included decreased basal cell differentiation, Scd1 expression and triglyceride fatty acid desaturation and increased tumorigenicity by PPARγ1. In contrast, PPARγ2 expression significantly increased basal cell differentiation, Scd1 expression and AR expression and responsiveness. Finally, in confirmation of in vitro data, a PPARγ agonist versus high-fat diet (HFD) regimen in vivo confirmed that PPARγ agonization increased prostatic differentiation markers, whereas HFD downregulated PPARγ-regulated genes and decreased prostate differentiation. These data provide a rationale for pursuing a fundamental metabolic understanding of changes to glucose and fatty acid metabolism in benign and malignant prostatic diseases associated with systemic metabolic stress.