Interstitial Leydig cell tumorigenesis : leptin and adiponectin signaling in relation to aromatase expression in the human testis

Although epidemiological studies from the last years report an increase in the incidences of Leydig cell tumors (previously thought to be a rare disease), the biochemical characteristics of that tumor important for understanding its etiology, diagnosis, and therapy still remains not completely characterized. Our prior studies reported G-protein coupled estrogen receptor signaling and estrogen level disturbances in Leydig cell tumors. In addition, we found that expressions of multi-level-acting lipid balance- and steroidogenesis–controlling proteins including peroxisome proliferator-activated receptor are altered in this tumor. In order to get deeper into the other molecular mechanisms that regulate lipid homeostasis in the Leydig cell tumor, here we investigate the presence and expression of newly-described hormones responsible for lipid homeostasis balancing (leptin and adiponectin), together with expression of estrogen synthase (aromatase). Samples of Leydig cell tumors (n = 20) were obtained from patients (31-45 years old) and used for light and transmission electron microscopic, western blotting, and immunohistochemical analyses. In addition, body mass index (BMI) was calculated. In tumor mass, abundant lipid accumulation in Leydig cells and various alterations of Leydig cell shape, as well as the presence of adipocyte-like cells, were observed. Marked lipid content and various lipid droplet size, especially in obese patients, may indicate alterations in lipid homeostasis, lipid processing, and steroidogenic organelle function in response to interstitial tissue pathological changes. We revealed significantly increased expression of leptin, adiponectin and their receptors, as well as aromatase in Leydig cell tumors in comparison to control. The majority of patients (n = 13) were overweight as indicated by their BMI. Moreover, a significant increase in expression of phospholipase C (PLC), and kinases Raf, ERK which are part of adipokine transductional pathways, was demonstrated. These data expand our previous findings suggesting that in human Leydig cell tumors, estrogen level and signaling, together with lipid status, are related to each other. Increased BMI may contribute to certain biochemical characteristics and function of the Leydig cell in infertile patients with a tumor. In addition, altered adipokine-estrogen microenvironment can have an effect on proliferation, growth, and metastasis of tumor cells. We report here various targets (receptors, enzymes, hormones) controlling lipid balance and estrogen action in Leydig cell tumors indicating their possible usefulness for diagnostics and therapy

Effects of flutamide on the expression of nectin in the rat male gonad

W regulacji procesu spermatogenezy ważną rolę odgrywa komunikacja pomiędzy komórkami gonady za którą odpowiadają wyspecjalizowane połączenia międzykomórkowe. Obecność połączeń między sąsiadującymi komórkami Sertoliego oraz między komórkami Sertoliego, a komórkami germinalnymi zapewnia wyspecjalizowane środowisko, między innymi poprzez formowanie bariery krew-jądro (BTB, ang. Blood-Testis Barrier). Jednym z białek tworzących połączenia międzykomórkowe w obrębie bariery krew-jądro jest białko adhezyjne, niezależne od jonów wapnia - nektyna. Głównym celem pracy było zbadanie ekspresji nektyny w jądrach szczurów po ekspozycji na flutamid. Do badań użyto modelu szczurzego in vivo. W celu oceny lokalizacji i ekspresji nektyny w jądrze szczura przeprowadzono analizę immunohistochemiczną potwierdzoną analizą ilościową barwnej reakcji. Aby potwierdzić otrzymane wyniki przeprowadzono również analizę Western blot i qRT-PCR. Rezultaty obu analiz opracowano statystycznie.Analiza immunohistochemiczna tkanek jądra szczurów eksponowanych na flutamid wykazała obniżenie ekspresji nektyny w stosunku do kontroli, zarówno w tkance interstycjalnej jak i w kanaliku plemnikotwórczym. Ponad to stwierdzono zmiany w morfologii tkanki interstycjalnej, jednak nie wykazano zmian w budowie kanalików plemnikotwórczych. Spadek poziomu ekspresji nektyny w jądrze szczura po ekspozycji na flutamid został również potwierdzony na poziomie mRNA (p<0.05) i białka (p<0.01). Otrzymane wyniki wskazują, iż anty-androgeny zaburzają ekspresję białka połączeń międzykomórkowych – nektyny. Obserwowane zmiany mogą skutkować zaburzeniem homeostazy oraz procesu spermatogenezy u szczura.Spermatogenesis is regulated by testicular cell-cell interactions via specialized junctions. Cell-cell junctions between Sertoli cells and Sertoli cells and germ cells create a specialized microenvironment, through the formation of the blood-testis barrier (BTB). Nectin-2 is a Ca2+-independent cell-cell adhesion molecule that is one of the BTB components.The aim of this study was to investigate the expression of nectin in testis of adult rat after treatment with anti-androgen – flutamide. This study was carried out in rat in vivo model using immunohistochemistry and quantitative analysis of the intensity of nectin immunostaining. Moreover, to confirm the results of immunohistochemical analysis Western blot and qRT-PCR were performed. Histological analysis of testis showed hyperplasia of interstitial tissue but a normal morphology of the seminiferous tubules. Moreover, flutamide treatment caused a statistically significant decrease of nectin expression at mRNA (p<0.05) and protein levels (p<0.01). Immunohistochemical analysis revealed decrease in the intensity of the stanning of nectin protein.The results of this study showed that anti-androgens affect the expression of junction protein – nectin. The observed changes may have adverse effects on the homeostasis of the blood-testis barrier and spermatogenesis

Blood-testis barrier as a complicated structure

Bariera krew-jądro jest ważną i skomplikowaną strukturą, która umożliwia prawidłowe różnicowanie się komórek germinalnych. Celem tej pracy było przedstawienie molekularnej budowy bariery krew-jądro z uwzględnieniem tworzących ją połączeń międzykomórkowych. W obrębie bariery krew-jądro wyróżnia się: połączenia ścisłe, połączenia szczelinowe, połączenia desmosomopodobne oraz bazalne specjalizacje powierzchniowe. Ponadto, w pracy przedstawiono funkcje bariery krew-jądro oraz dla pełniejszego zrozumienia lokalizacji tej struktury zaprezentowana została krótka charakterystyka budowy i funkcji gonady męskiej.Blood-testis barrier is a very important and complicated structrure that allows normal germ cell differentation. The aim of this work is to show molecular structure of blood-testis barrier based on cell junctions. Blood-testis barrier is composed of: tight junctions, gap junctions, desmosome-like junctions, basal ectoplasmic specializations. Moreover, this work presents several functions of blood-testis barrier and for full understanding short description of testis structure and testicular cell function was presented

Nuclear and membrane receptors for sex steroids are involved in the regulation of Delta/Serrate/LAG-2 proteins in rodent Sertoli cells

Delta/Serrate/LAG-2 (DSL) proteins, which serve as ligands for Notch receptors, mediate direct cell–cell interactions involved in the determination of cell fate and functioning. The present study aimed to explore the role of androgens and estrogens, and their receptors in the regulation of DSL proteins in Sertoli cells. To this end, primary rat Sertoli cells and TM4 Sertoli cell line were treated with either testosterone or 17β-estradiol and antagonists of their receptors. To confirm the role of particular receptors, knockdown experiments were performed. mRNA and protein expressions of Jagged1 (JAG1), Delta-like1 (DLL1), and Delta-like4 (DLL4) were analyzed using RT-qPCR, Western blot, and immunofluorescence. Testosterone caused downregulation of JAG1 and DLL1 expression, acting through membrane androgen receptor ZRT- and Irt-like protein 9 (ZIP9) or nuclear androgen receptor (AR), respectively. DLL4 was stimulated by testosterone in the manner independent of AR and ZIP9 in Sertoli cells. The expression of all studied DSL proteins was upregulated by 17β-estradiol. Estrogen action on JAG1 and DLL1 was mediated chiefly via estrogen receptor α (ERα), while DLL4 was controlled via estrogen receptor β (ERβ) and membrane G-protein-coupled estrogen receptor (GPER). To summarize, the co-operation of nuclear and membrane receptors for sex steroids controls DSL proteins in Sertoli cells, contributing to balanced Notch signaling activity in seminiferous epithelium