The effects of flutamide on cell-cell junctions in the testis, epididymis, and prostate

17β-Trenbolone activates androgen receptor, upregulates transforming growth factor beta/bone morphogenetic protein and Wnt signaling pathways, and induces masculinization of caudal and anal fins in female guppies (Poecilia reticulata)

Sexually mature female guppies (Poecilia reticulata) were exposed to environmentally relevant concentrations (20, 200, and 2000 ng/L) of 17β-trenbolone for four weeks. As evidenced by the increased caudal fin index and anal fins developing into gonopodium-like structures, exposed females displayed masculinized secondary sexual characteristics. Differential gene expression and subsequent pathway analysis of mRNA sequencing data revealed that the transcription of transforming growth factor beta/bone morphogenetic protein signaling pathway and Wnt signaling pathway were upregulated following 17β-trenbolone exposure. Enzyme-linked immunosorbent assays showed that the bone morphogenetic protein 7 protein content was elevated after 17β-trenbolone exposure. Finally, real-time PCR revealed that 17β-trenbolone treatment significantly increased androgen receptor mRNA levels, and molecular docking showed potent interaction between 17β-trenbolone and guppy androgen receptor. Furthermore, 17β-trenbolone-induced masculinization of caudal and anal fins in female guppies, concomitant to the upregulated expression of differentially expressed genes involved in the above-mentioned two signaling pathways, was significantly inhibited by flutamide (androgen receptor antagonist). These findings demonstrated that 17β-trenbolone masculinized fins of female guppies by activating the androgen receptor. This study revealed that 17β-trenbolone could upregulate signaling pathways related to fin growth and differentiation, and eventually cause caudal and anal fin masculinization in female guppies.

Interrupting the blood-testis barrier with a flutamide-loaded nanostructured lipid carrier: A novel nonsurgical contraceptive approach for male animals

Flutamide is an antagonist of testosterone, an essential hormone in male reproduction. However, the use of flutamide as a contraceptive agent for nonsurgical castration in veterinary practice remains challenging due to its poor bioavailability. Here, the flutamide-loaded nanostructure lipid carrier (FLT-NLC) was synthesized, and its biological effects were demonstrated by an in vitro blood-testis barrier model. The flutamide was incorporated into the nanostructure lipid carrier by a homogenization method resulting in a high encapsulation efficiency (99.7 ± 0.04%). The FLT-NLC was negatively charged (-27.90 ± 0.10 mV), with a nano size (182.13 ± 0.47 nm) and narrow dispersity index (0.17 ± 0.01). An in vitro release study demonstrated a slower release profile of FLT-NLC when compared with flutamide solution (FLT). The FLT-NLC at doses up to 50 μM showed no significant cytotoxic effects against mouse Sertoli cells (TM4) or mouse fibroblast cells (NIH/3T3) (p > 0.05). An in vitro blood-testis barrier with FLT-NLC demonstrated remarkable lower transepithelial electrical resistance when compared with those lacking FLT-NLC (p < 0.01). Moreover, FLT-NLC significantly decreased the mRNA expression of blood-testis barrier proteins, CLDN11 and OCLN. In conclusion, we successfully synthesized FLT-NLC and confirmed its potential antifertility effects on in vitro blood-testis barrier, thus indicating its possible application as nonsurgical contraception for male animals.

Haemolytic anaemia induced by flutamide: a case report

Flutamide-induced haemolytic anaemia is rare but can be fatal. We describe the case of an 88-year-old man with prostatic carcinoma who, in addition to clinically obvious jaundice, developed haemolytic anaemia after undergoing treatment with flutamide for 5 days. When flutamide was replaced with temporary adrenocortical hormone treatment and blood transfusion, the blood indices and liver function of the patient improved gradually. We emphasise the need for routine monitoring of blood counts for patients undergoing flutamide treatment, and highlight the importance of discontinuing flutamide immediately when haemolytic anaemia occurs.

Effect of dihydrotestosterone on melatonin secretion and the expression of melatonin receptors and apoptosis-related factors in sheep epididymides

Melatonin (MEL) is involved in homeostasis of the epididymis lumen environment. Dihydrotestosterone (DHT) partakes in the development of gonads and organs in male animals. However, whether MEL secretion, the expression of its receptors, MT1 and MT2, and sheep epididymal epithelial cell apoptosis is regulated by DHT remains unclear. In this study, we used immunohistochemical staining to detect the distribution patterns of DHT synthetases [5α-reductase (5α-red)] and its androgen receptor (AR) in sheep epididymides. 5α-red1, 5α-red2, and AR were positively expressed in sperm, epididymal epithelial cells, and the smooth muscle cells of the caput, corpus, and cauda regions of the epididymis. DHT concentration and the expression levels of 5α-red and AR in the caput, corpus, and cauda regions were measured by enzyme-linked immunosorbent assay, liquid chromatography-mass spectrometry, real-time quantitative polymerase chain reaction, and western blot analysis. DHT concentration in the caput was significantly higher than those in corpus and cauda, probably because of the high expression of 5α-red2 in the caput and secretion and transport of DHT by the testicles. DHT inhibited MEL secretion, the expression of its membrane receptors, and MEL synthetases in cultured sheep epididymal epithelial cells in vitro. In addition, the Bax/Bcl-2 ratio, ACT CASP3, and caspase-3 mRNA expression were also decreased. The decreasing effect was partially reversed after flutamide treatment. Therefore, DHT regulates sheep epididymal function by influencing MEL expression and apoptosis-related factors. This study provides basic data for further research on the reproductive physiology of male animals.

Differential gene expression and hallmarks of stemness in epithelial cells of the developing rat epididymis

Epididymal development can be subdivided into three phases: undifferentiated, a period of differentiation, and expansion. The objectives of this study were (1) to assess gene expression profiles in epididymides, (2) predict signaling pathways, and (3) develop a novel 3D cell culture method to assess the regulation of epididymal development in vitro. Microarray analyses indicate that the largest changes in differential gene expression occurred between the 7- to 18-day period, in which 1452 genes were differentially expressed, while 671 differentially expressed genes were noted between days 18 and 28, and there were 560 differentially expressed genes between days 28 and 60. Multiple signaling pathways were predicted at different phases of development. Pathway associations indicated that in epididymides of 7- to 18-day old rats, there was a significant association of regulated genes implicated in stem cells, estrogens, thyroid hormones, and kidney development, while androgen- and estrogen-related pathways were enriched at other phases of development. Organoids were derived from CD49f + columnar cells from 7-day old rats, while no organoids developed from CD49f^- cells. Cells cultured in an epididymal basal cell organoid medium versus a commercial kidney differentiation medium supplemented with DHT revealed that irrespective of the culture medium, cells within differentiating organoids expressed p63, AQP9, and V-ATPase after 14 days of culture. The commercial kidney medium resulted in an increase in the number of organoids positive for p63, AQP9, and V-ATPase. Together, these data indicate that columnar cells represent an epididymal stem/progenitor cell population.

Microenvironment for spermatogenesis and sperm maturation

The male reproductive system consists of testes, a series of ducts connecting the testes to the external urethral orifice, accessory sex glands, and the penis. Spermatogonial stem cells differentiate and mature in testes and epididymides, and spermatozoa are ejaculated with exocrine fluids secreted by accessory sex glands. Many studies have clarified the detailed structure and function of the male reproductive system, and have shown that various biologic controls, including genomics, epigenetics, and the neuroendocrine-immune system regulate proliferation, differentiation, and maturation of germ cells. In other words (1) genetic deletion or abnormalities, (2) aberration of DNA methylation and histone modifications, as well as small RNA dysfunction, and (3) neuroendocrine-immune disorders are involved in functional failure of the male reproductive system. In this article, we review these three factors for germ cell microcircumstance, especially focused on the immunoendocrine environment. In particular, the relation between factors protecting germ cells with strong auto-immunogenicity and opposite factors compromising this protection are discussed. Reductions in sperm count, concentration, and semen quality are serious problems in developed countries, although the causes are complex and remain unclear. The accumulation of basic knowledge regarding the structure, function, and regulation of the male reproductive system under various experimental conditions will be important to resolve these problems.

Cell-Cell Interaction-Mediated Signaling in the Testis Induces Reproductive Dysfunction—Lesson from the Toxicant/Pharmaceutical Models

Emerging evidence has shown that cell-cell interactions between testicular cells, in particular at the Sertoli cell-cell and Sertoli-germ cell interface, are crucial to support spermatogenesis. The unique ultrastructures that support cell-cell interactions in the testis are the basal ES (ectoplasmic specialization) and the apical ES. The basal ES is found between adjacent Sertoli cells near the basement membrane that also constitute the blood-testis barrier (BTB). The apical ES is restrictively expressed at the Sertoli-spermatid contact site in the apical (adluminal) compartment of the seminiferous epithelium. These ultrastructures are present in both rodent and human testes, but the majority of studies found in the literature were done in rodent testes. As such, our discussion herein, unless otherwise specified, is focused on studies in testes of adult rats. Studies have shown that the testicular cell-cell interactions crucial to support spermatogenesis are mediated through distinctive signaling proteins and pathways, most notably involving FAK, Akt1/2 and Cdc42 GTPase. Thus, manipulation of some of these signaling proteins, such as FAK, through the use of phosphomimetic mutants for overexpression in Sertoli cell epithelium in vitro or in the testis in vivo, making FAK either constitutively active or inactive, we can modify the outcome of spermatogenesis. For instance, using the toxicant-induced Sertoli cell or testis injury in rats as study models, we can either block or rescue toxicant-induced infertility through overexpression of p-FAK-Y397 or p-FAK-Y407 (and their mutants), including the use of specific activator(s) of the involved signaling proteins against pAkt1/2. These findings thus illustrate that a potential therapeutic approach can be developed to manage toxicant-induced male reproductive dysfunction. In this review, we critically evaluate these recent findings, highlighting the direction for future investigations by bringing the laboratory-based research through a translation path to clinical investigations.

Screening of hub genes and evaluation of the growth regulatory role of CD44 in metastatic prostate cancer

Prostate cancer (PCa) is the most common cancer type in men worldwide. Currently, the management of metastatic PCa (mPCa) remains a challenge to urologists. The analysis of hub genes and pathways may facilitate the understanding of the molecular mechanism of PCa. In the present study, to identify the hub genes in the mPCa, the three datasets GSE3325, GSE6919 and GSE38241 were downloaded from the platform of the Gene Expression Omnibus and function enrichment analysis of differentially expressed genes (DEGs) was performed. A total of 168 DEGs were obtained and the DEGs were significantly enriched in ‘cell junction’ and ‘cell adhesion’, among others. The Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis demonstrated that DEGs were enriched in three pathways including ‘focal adhesion’, ‘renal cell carcinoma’ and ‘Hippo signaling pathway’. The results of the protein-protein interaction network revealed that the hub genes in mPCa were separately PTEN, Rac GTPase-activating protein 1, protein regulator of cytokinesis 1, PDZ binding kinase, centromere-associated protein E, NUF2 component of NDC80 kinetochore complex, TPX2 microtubule nucleation factor, SOX2, CD44 and ubiquitin-like with PHD and ring finger domains 1. As a hub gene, CD44 was differentially expressed in PCa, as determined by Oncomine analysis. Further experiments in vivo demonstrated that SB-3CT, a selective matrix metalloproteinase inhibitor that has been reported to block CD44 cleavage and inhibit the downstream signaling pathway, suppressed the tumorigenicity of PCa cells by decreasing the expression levels of pyruvate dehydrogenase kinase 1 and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 4. Moreover, the combination therapy with SB-3CT and docetaxel was more effective in inhibiting PCa compared with monotherapy. In conclusion, the identification of DEGs and the in vivo experimental results helped to elucidate the molecular mechanisms of PCa and provided a potential strategy for the treatment of PCa.

Flutamide treatment reveals a relationship between steroidogenic activity of Leydig cells and ultrastructure of their mitochondria

Our present knowledge on interrelation between morphology/ultrastructure of mitochondria of the Leydig cell and its steroidogenic function is far from satisfactory and needs additional studies. Here, we analyzed the effects of blockade of androgen receptor, triggered by exposure to flutamide, on the expression of steroidogenic proteins (1) and ultrastructure of Leydig cells' constituents (2). We demonstrated that increase in the expression level of steroidogenic (StAR, CYP11A1, 3β-HSD, and CYP19A1) proteins (and respective mRNAs) in rat testicular tissue as well as elevation of intratesticular sex steroid hormone (testosterone and estradiol) levels observed in treated animals correspond well to morphological alterations of the Leydig cell ultrastructure. Most importantly, up-regulation of steroidogenic proteins' expression apparently correlates with considerable multiplication of Leydig cell mitochondria and subsequent formation of local mitochondrial networks. Interestingly, we showed also that the above-mentioned processes were associated with elevated transcription of Drp1 and Mfn2 genes, encoding proteins implicated in mitochondrial dynamics. Collectively, our studies emphasize the importance of mitochondrial homeostasis to the steroidogenic function of Leydig cells.

Papain Mediated Synthesized Gold Nanoparticles Encore the Potency of Bioconjugated Flutamide

BACKGROUND

Prostate cancer is the second most common cause of male cancer death after lung cancer in the US. Therefore, there is an urgent need for a highly effective therapeutic drug at substantially low doses.

OBJECTIVE

Anti-androgen drug flutamide was delivered to the prostate cancer cells using Papain Mediated Synthesized Gold Nanoparticles (PGNPs) as the drug delivery system. PGNPs and flutamide worked synergistically against cancer cells.

METHODS

Flutamide was used to bioconjugate with PGNPs to improve its efficacy against prostate cancer. The synthesis and bioconjugation of flutamide with PGNPs (F-PGNPs) were characterized by various characterization techniques such as UV-vis spectroscopy, Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), and zeta potential to ensure the synthesis, size, shape, size distribution, and stability. The drug loading efficiency of flutamide in F-PGNPs was confirmed and validated by UV-vis spectroscopy. Eventually, in vitro studies were performed to determine the potency of F-PGNPs, changes in nuclear morphology, and generation of Reactive Oxygen Species (ROS).

RESULTS

The efficacy of F-PGNPs (IC₅₀ is 46.54 μg/mL) was found to be improved significantly over pure flutamide (IC50 is 64.63 μg/mL) against human prostate cancer PC-3 cell line whereas F-PGNPs did not show any significant toxicity up to a fairly high concentration toward normal mouse macrophage J774A.1 cells. The apoptotic effects and ROS generation of F-PGNPs were analyzed by increased permeability of the cell membrane and condensed chromatin with deep blue and green fluorescent nucleus, respectively.

DISCUSSION

The results clearly showed that F-PGNPs significantly improved the potency of flutamide by delivering it directly into the nucleus of cancer cells through caveolae-dependent endocytosis.

CONCLUSION

Thus, the greater inhibitory effect of F-PGNPs over the pure drug would be of great advantage during prostate cancer treatment.

Changes in porcine cauda epididymal fluid proteome by disrupting the HPT axis: Unveiling potential mechanisms of male infertility

Male infertility or subfertility is frequently associated with disruption of the hypothalamic-pituitary-testis axis events, like secondary hypogonadism. However, little is known how this condition affects the proteomic composition of the epididymal fluid. In the present study, we evaluated the proteomic changes in the cauda epididymal fluid (CEF) in a swine model of secondary hypogonadism induced by anti-GnRH immunization using multidimensional protein identification technology. Seven hundred and eighteen proteins were identified in both GnRH-immunized and control groups. GnRH immunization doubled the number of proteins in the CEF, with 417 proteins being found exclusively in samples from GnRH-immunized boars. CEF from GnRH-immunized boars presented an increase in the number of proteins related to cellular and metabolic processes, with affinity to organic cyclic compounds, small molecules, and heterocyclic compounds, as well changed the enzymatic profile of the CEF. Also, a significant increase in the number of proteins associated to the ubiquitin-proteasome system was identified in CEF from GnRH-immunized animals. These results bring strong evidence of the impact of secondary hypogonadism on the epididymal environment, which is responsible for sperm maturation and storage prior ejaculation. Finally, the differently expressed proteins in the CEF are putative seminal biomarkers for testicular and epididymal disorders caused by secondary hypogonadism.

Life-long testosterone and antiandrogen treatments affect the survival and reproduction of captive male red-legged partridges (Alectoris rufa)

Abstract

Sexual steroids can play an important role as life-history organizers. In males, high circulating testosterone levels induce physiological/behavioral costs and benefits, leading to trade-offs. However, studies simultaneously testing the impact of these levels in both fitness components (survival and fecundity) during lifetime are scarce and limited to wild birds. To determine the mortality causes or hormonal manipulation impacts on male fertility is, nonetheless, a difficult task in free-ranging animals that could be easier in captivity. We longitudinally monitored captive red-legged partridges (Alectoris rufa) and exposed males to high exogenous testosterone levels, anti-androgens, or a control treatment during each breeding period throughout their lives. Theory predicts that individuals maintaining high androgen levels should obtain higher fitness returns via reproduction, but suffer reduced longevity. Testosterone-treated male partridges, accordingly, lived shorter compared to controls, since they were more prone to die from a natural bacterial infection. However, the same birds seemed to have a lower capacity to fertilize eggs, probably due to endocrine feedback reducing testicular mass. These results show that exogenous testosterone can exert unpredicted effects on fitness parameters. Therefore, caution must be taken when drawing conclusions from non-fully controlled experiments in the wild. Males treated with the androgen-receptor blocker flutamide did not outlive controls as predicted by the life-history trade-off theory, but their mates laid eggs with higher hatching success. The latter could be due to mechanisms improving sperm quality/quantity or influencing maternal investment in egg quality. Testosterone receptor activity/amount could thus be as relevant to fitness as testosterone levels.

Significance statement

It has repeatedly been hypothesized that high testosterone levels induce a cost in terms of reduced lifetime reproductive success. This can be due to reduced fecundity or via shorter lifespan. This is, however, only supported by a handful of studies, mostly in wild birds. We tested this in captive male red-legged partridges, which allowed us to determine reproductive success and mortality causes. We increased testosterone levels or blocked its action with antiandrogens throughout life. High testosterone levels reduced the survival by making birds more prone to die by infection. The eggs produced by their mates also showed lower hatching success, a probable manipulation artifact that should be considered in avian studies in the wild. Interestingly, the androgen-receptor blocker flutamide increased lifetime hatching success compared to controls, suggesting that androgen receptor amounts/activity are even more relevant to fitness than testosterone levels.

Role of non-classical effects of testosterone and epitestosterone on AMH balance and testicular development parameters

Testosterone (T) and its 17-α epimer, epitestosterone (EpiT), are described as having non-classical effects in addition to their classical androgen actions via the intracellular androgen receptor (iAR). The actions of these androgens play an essential role in triggering factors that shift Sertoli cells from the proliferation phase to the maturation phase. This process is essential for successful spermatogenesis and normal fertility. The aim of this work was to investigate the difference between T and EpiT effects in normal and in chemically castrated Wistar rats. We also tested the effects of these hormones when the iAR-dependent pathways were inhibited by the antiandrogen flutamide. Rats were chemically castrated on postnatal day (pnd) 5 using EDS, a cytotoxic agent that promotes apoptosis of Leydig cells, reducing androgen levels. Then, animals received replacement with T or EpiT and were treated or not with flutamide from pnd 6 to pnd 13 or 20 and were euthanized on pnd 14 and 21. Animals treated with EpiT and flutamide had lower body weight overall. Epididymis weight was also reduced in animals treated with EpiT and flutamide. Flutamide per se reduced epididymis weight at both ages (pnd 14 and 21). Testicular weight and the testicular/body weight ratio were reduced in EDS animals, and flutamide further reduced this weight in animals which received T replacement. EDS administration reduced mRNA levels of both AMH (anti-Müllerian hormone) and its receptor, AMHR2, at pnd 14. In the testes of flutamide-treated animals, EpiT reduced AMH, and both T and EpiT replacement diminished AMHR2 mRNA expression also on pnd 14. EDS decreased iAR expression, and androgen replacement did not change this effect on pnd 21. In rats receiving flutamide, only those also receiving T and EpiT replacement exhibited decreased iAR expression. An increase in connexin 43 expression was observed in animals treated with EpiT without flutamide, whereas in rats treated with flutamide, both hormones were ineffective to increase connexin 43 expression reduced by EDS. Our results suggest that EpiT has an antiandrogen effect on androgen-sensitive tissues such as the epididymis. Nonetheless, the effects of T and EpiT on testicular development parameters are similar. Both hormones may act through their iAR-independent non-classical pathway, regulating AMH and AMHR2, as well as iAR expression.

Flutamide Alters the Expression of Chemerin, Apelin, and Vaspin and Their Respective Receptors in the Testes of Adult Rats

Adipokines influence energy metabolism and have effects on male reproduction, including spermatogenesis and/or Sertoli cell maturation; however, the relationship between these active proteins and androgens in testicular cells is limited. Here, we studied the impact of short-term exposure to flutamide (an anti-androgen that blocks androgen receptors) on the expression of chemerin, apelin, vaspin and their receptors (CCRL2, CMKLR1, GPR1, APLNR, GRP78, respectively) in adult rat testes. Moreover, the levels of expression of lipid metabolism-modulating proteins (PLIN1, perilipin1; TSPO, translocator protein) and intercellular adherens junction proteins (nectin-2 and afadin) were determined in testicular cells. Plasma levels of adipokines, testosterone and cholesterol were also evaluated. Gene expression techniques used included the quantitative real-time polymerase chain reaction (qRT-PCR), Western blot (WB) and immunohistochemistry (IHC). The androgen-mediated effects observed post-flutamide treatment were found at the gonadal level as chemerin, apelin, and vaspin gene expression alterations at mRNA and protein levels were detected, whereas the cellular targets for these adipokines were recognised by localisation of respective receptors in testicular cells. Plasma concentrations of all adipokines were unchanged, whereas plasma cholesterol content and testosterone level increased after flutamide exposure. Differential distribution of adipokine receptors indicates potential para- or autocrine action of the adipokines within the rat testes. Additionally, changes in the expression of PLIN1 and TSPO, involved in the initial step of testosterone synthesis in Leydig cells, suggest that testicular cells represent a target of flutamide action. Increase in the gene expression of PLIN1 and TSPO and higher total plasma cholesterol content indicates enhanced availability of cholesterol in Leydig cells as a result of androgen-mediated effects of flutamide. Alterations in adherens junction protein expression in the testis confirm the flutamide efficacy in disruption of androgen signalling and presumably lead to impaired para- and autocrine communication, important for proper functioning of adipokines.

Secondary Resistant Mutations to Small Molecule Inhibitors in Cancer Cells

Secondary resistant mutations in cancer cells arise in response to certain small molecule inhibitors. These mutations inevitably cause recurrence and often progression to a more aggressive form. Resistant mutations may manifest in various forms. For example, some mutations decrease or abrogate the affinity of the drug for the protein. Others restore the function of the enzyme even in the presence of the inhibitor. In some cases, resistance is acquired through activation of a parallel pathway which bypasses the function of the drug targeted pathway. The Catalogue of Somatic Mutations in Cancer (COSMIC) produced a compendium of resistant mutations to small molecule inhibitors reported in the literature. Here, we build on these data and provide a comprehensive review of resistant mutations in cancers. We also discuss mechanistic parallels of resistance.

Crucial role of androgen receptor in resistance and endurance trainings-induced muscle hypertrophy through IGF-1/IGF-1R- PI3K/Akt- mTOR pathway

Background

Androgen receptor (AR) has been reported to play vital roles in exercise-induced increase of muscle mass in rats, but needs to be further verified and the mechanism behind remains unclear. As AR target genes, insulin growth factor-1 (IGF-1) and IGF-1 receptor (IGF-1R) promote muscle hypertrophy through activating PI3K/Akt- mammalian target of rapamycin (mTOR) pathway, a classic pathway of muscle hypertrophy. So the main purpose of this study was using AR antagonist flutamide to demonstrate AR’s effect on training-induced muscle hypertrophy and its possible mechanism: IGF-1/IGF-1R- PI3K/Akt- mTOR pathway?

Methods

Forty-eight Sprague Dawley male rats aged 7 weeks were randomly divided into six groups: control (C), flutamide (F), resistance training (R), resistance training plus flutamide (R + F), endurance training (E), and endurance training plus flutamide (E + F) groups. Flutamide was used to block AR in rats. Rats in R and R + F groups fulfilled 3 weeks of ladder climbing with progressively increased load, while E and E + F rats completed 3-week moderate intensity aerobic exercise on a treadmill. The relative muscle mass (muscle mass/body weight) of rats was detected. Serum levels of testosterone and IGF-1 of rats were determined by ELISA, and mRNA levels of IGF-1R and mTOR in muscles by real-time PCR. Protein levels of AR, IGF-1, IGF-1R, mTOR, PI3K, Akt, p-PI3K and p-Akt in muscles were detected by Western blot.

Results

(1) The training-induced rise in the relative muscle mass and the expression levels of AR were only found in the gastrocnemius of R rats and in the soleus of E rats (selective muscle hypertrophy), which were blocked by flutamide. (2) Serum testosterone in the R and E rat were increased, and flutamide exerted no effect. (3) The levels of IGF-1, IGF-1R and mTOR as well as the activities of PI3K and Akt were enhanced selectively (in the gastrocnemius of R rats and in the soleus of E rats), which were reduced by flutamide. Conclusions: AR exerted an essential role in both resistance training and endurance training-induced muscle hypertrophy, which was mediated at least partly through IGF-1/IGF-1R- PI3K/Akt- mTOR pathway.

Differential expression of cell-cell junction proteins in the testis, epididymis, and ductus deferens of domestic turkeys (Meleagris gallopavo) with white and yellow semen

Tight, adherens, and gap junctions are involved in the regulation of reproductive tissue function in male mammals. In birds, including domestic turkeys, intercellular interactions performed by junctional networks have not yet been studied. Furthermore, the cellular and molecular basis of yellow semen syndrome (YSS) in the turkey population remains poorly understood. Thus, the aim of the present study was 2-fold: first, to provide new information on the localization and expression of cell-cell junction proteins in the testis, epididymis, and ductus deferens of domestic turkeys and second, to compare expression of junctional protein genes between 2 turkey population, one that produces white normal semen (WNS) and the other that produces yellow abnormal semen. Expression of occludin, zonula occludens-1 (ZO-1), connexin 43 (Cx43), N- and E-cadherin, and β-catenin genes were investigated using 3 complementary techniques: quantitative real-time PCR, western blot, and immunohistochemistry. Compared to WNS testis, epididymis, and ductus deferens, YSS tissues exhibited downregulation of occludin and β-catenin mRNA (P < 0.05) and protein (P < 0.05 and P < 0.01, respectively) and upregulation of N- and E-cadherin mRNA (P < 0.001, P < 0.05, P < 0.01, respectively) and protein (P < 0.01, P < 0.05, and P < 0.05, respectively). In contrast, ZO-1 and Cx43 mRNA and protein were upregulated in YSS testis (P < 0.05 and P < 0.001, respectively) but not in epididymis and ductus deferens; both mRNAs and proteins were downregulated (P < 0.05) compared to the respective WNS epididymis and ductus deferens. Altered staining intensity of immunoreactive proteins in YSS vs. WNS reproductive tissue sections confirmed the gene expression results. The present study is the first to demonstrate altered levels of junctional protein gene expression in reproductive tissues of male YSS turkeys. These findings may suggest that subtle changes in junctional protein expression affect the microenvironment in which spermatozoa develop and mature and thus may have an impact on the appearance of yellow semen in domestic turkeys.