A Step Forward in Understanding the Expression of Classical Aquaporins in the Male Reproductive Tract: Study Findings in Cattle (Bos taurus).

Aquaporins (AQPs), also known as water channels, appear to be particularly promising in maintaining male reproductive potential. Therefore, this study aimed to determine the presence of classical AQPs in the bovine (Bos taurus) reproductive system and analyze changes in their expression with age using immunohistochemistry and Western blotting. Of the six classical AQPs, AQP0, AQP1, AQP4, AQP5 and AQP6 were detected, while AQP2 was absent. In the testis, AQP0 was visible in Leydig cells in selected animals, while AQP1 was found in myoid cells surrounding the seminiferous tubules of mature individuals. This characteristic expression patterns of AQP0, limited only to certain bulls, is difficult to explain unequivocally. It is possible that AQP0 expression in cattle is subject to individual variability or changes in response to specific physiological conditions. In the caput and corpus epididymis, AQP0 showed weak expression in epithelial cells of immature animals and stronger expression in basal and principal cells of reproductive bulls. In all animals, AQP1 was present on the apical surface of epithelial cells in the initial segment of the caput epididymis. AQP4, AQP5 and AQP6 were identified in principal and basal cells along the entire epididymis of reproductive bulls. The abundance of AQP4 and AQP6 increased from the caput to the cauda epididymis with the growth and development of the animals. In all males, AQP4, AQP5 and AQP6 were observed in epithelial cells of the vas deferens, and their expression in this section increased with age. In conclusion, the abundance and distribution of the classical AQPs in various cell types and parts of the male reproductive system indicate their crucial role in maintaining water homeostasis, which is essential for normal reproductive function in cattle.

Expression and Clinical Significance of Non B Cell-Derived Immunoglobulins in the Urinary System and Male Reproductive System.

The urinary system comprises kidneys, ureters, bladder, and urethra with its primary function being excretion, referring to the physiological process of transporting substances that are harmful or surplus out of the body. The male reproductive system consists of gonads (testis), vas deferens, and accessory glands such as the prostate. According to classical immunology theory, the tissues and organs mentioned above are not thought to produce immunoglobulins (Igs), and any Ig present in the relevant tissues under physiological and pathological conditions is believed to be derived from B cells. For instance, most renal diseases are associated with uncontrolled inflammation caused by pathogenic Ig deposited in the kidney. Generally, these pathological Igs are presumed to be produced by B cells. Recent studies have demonstrated that renal parenchymal cells can produce and secrete Igs, including IgA and IgG. Glomerular mesangial cells can express and secrete IgA, which is associated with cell survival and adhesion. Likewise, human podocytes demonstrate the ability to produce and secrete IgG, which is related to cell survival and adhesion. Furthermore, renal tubular epithelial cells also express IgG, potentially involved in the epithelial-mesenchymal transition (EMT). More significantly, renal cell carcinoma, bladder cancer, and prostate cancer have been revealed to express high levels of IgG, which promotes tumour progression. Given the widespread Ig expression in the urinary and male reproductive systems, continued efforts to elucidate the roles of Igs in renal physiological and pathological processes are necessary.

Role of hydrogen sulfide in the male reproductive system.

As an important gas signaling molecule, hydrogen sulfide (H2S) affects multiple organ systems, including the nervous, cardiovascular, digestive, and genitourinary, reproductive systems. In particular, H2S not only regulates female reproductive function but also holds great promise in the treatment of male reproductive diseases and disorders, such as erectile dysfunction, prostate cancer, varicocele, and infertility. In this review, we summarize the relationship between H2S and male reproductive organs, including the penis, testis, prostate, vas deferens, and epididymis. As lower urinary tract symptoms have a significant impact on penile erection disorders, we also address the potential ameliorative effects of H2S in erectile dysfunction resulting from bladder disease. Additionally, we discuss the regulatory role of H2S in cavernous smooth muscle relaxation, which involves the NO/cGMP pathway, the RhoA/Rho-kinase pathway, and K+ channel activation. Recently, various compounds that can alleviate erectile dysfunction have been reported to be at least partly dependent on H2S. Therefore, understanding the role of H2S in the male reproductive system may help develop novel strategies for the clinical treatment of male reproductive system diseases.

A sperm-activating trypsin-like protease from the male reproductive tract of Spodoptera litura: Proteomic identification, sequence characterization, gene expression profile, RNAi and the effects of ionizing radiation.

Like other lepidopteran insects, males of the tobacco cutworm moth, Spodoptera litura produce two kinds of spermatozoa, eupyrene (nucleate) and apyrene (anucleate) sperm. Formed in the testis, both kinds of sperm are released into the male reproductive tract in an immature form and are stored in the duplex region of the tract. Neither type of sperm is motile at this stage. When stored apyrene sperm from the duplex are treated in vitro with an extract of the prostatic region of the male tract, or with mammalian trypsin, they become motile; activation is greater and achieved more rapidly with increasing concentration of extract or enzyme. The activating effect of prostatic extract is blocked by soybean trypsin inhibitor (SBTI), also in a dose-dependent way. These results suggest that the normal sperm-activating process is due to an endogenous trypsin-like protease produced in the prostatic region. Proteomic analysis of S. litura prostatic extracts revealed a Trypsin-Like Serine Protease, TLSP, molecular weight 27 kDa, whose 199-residue amino acid sequence is identical to that of a predicted protein from the S. litura genome and is highly similar to predicted proteins encoded by genes in the genomes of several other noctuid moth species. Surprisingly, TLSP is only distantly related to Serine Protease 2 (initiatorin) of the silkmoth, Bombyx mori, the only identified lepidopteran protein so far shown to activate sperm. TLSP has features typical of secreted proteins, probably being synthesized as an inactive precursor zymogen, which is later activated by proteolytic cleavage. cDNA was synthesized from total RNA extracted from the prostatic region and was used to examine TLSP expression using qPCR. tlsp mRNA was expressed in both the prostatic region and the accessory glands of the male tract. Injection of TLSP-specific dsRNA into adult males caused a significant reduction after 24 h in tlsp mRNA levels in both locations. The number of eggs laid by females mated to adult males that were given TLSP dsRNA in 10 % honey solution, and the fertility (% hatched) of the eggs were reduced. Injecting pupae with TLSP dsRNA caused the later activation of apyrene sperm motility by adult male prostatic extracts to be significantly reduced compared to controls. Exposure of S. litura pupae to ionizing radiation significantly reduced expression of tlsp mRNA in the prostatic part and accessory gland of irradiated males in both the irradiated generation and also in their (unirradiated) F1 progeny. The implications of these findings for the use of the inherited sterility technique for the control of S. litura and other pest Lepidoptera are discussed.

Comparing the effects and mechanisms of exposure to polystyrene nanoplastics with different functional groups on the male reproductive system.

After aging in the environment, some nanoplastics will carry different charges and functional groups, thereby altering their toxicological effects. To evaluate the potential impact of aging of nanoplastics on the mammalian reproductive system, we exposed C57BL/6 male mice to a dose of 5 mg/kg/d polystyrene nanoparticles (PS-NPs) with different functional groups (unmodified, carboxyl functionalized and amino functionalized) for 45 days for this study. The results suggest that PS-NPs with different functional groups triggered oxidative stress, a decreased in the testis index, disruption of the outer wall of the seminiferous tubules, reduction in the number of spermatogonia cells and sperm counts, and an increased in sperm malformations. We performed GO and KEGG enrichment analysis on the differentially expressed proteins, and found they were mainly enriched in protein transport, RNA splicing and mTOR signaling. We confirmed that the PI3K-AKT-mTOR pathway is over activated, which may lead to reduction of spermatogonia stem cells by over differentiation. Strikingly, PS-NPs with functional group modifications are more toxic than those of unmodified polystyrene, and that PS-NPs with positively charged amino modifications are the most toxic. This study provides a new understanding for correctly evaluating the toxicological effects of plastic aging, and of the mechanism responsible for the reproductive toxicity caused by nanoplastics.

Rol de la osteocalcina más allá del hueso / Role of osteocalcin beyond bone

Los hallazgos osteológicos se intensi!caron en los últimos años. Se demostró que el esqueleto se comporta, además de sus funciones clásicas, como un órgano de secreción endocrina que sintetiza al menos dos hormonas: el factor de crecimiento de !broblastos 23 (FGF-23) y la osteocalcina (Ocn). La Ocn es un péptido pequeño que contiene 3 residuos de ácido glutámico. Estos residuos se carboxilan postraduccionalmente, quedando retenida en la matriz ósea. La forma decarboxilada en el primer residuo de ácido glutámico (GluOcn) fue reportada por poseer efectos biológicos; la resorción ósea es el mecanismo clave para su bioactivación. La presente revisión se centra en los conocimientos actuales sobre la función hormonal de la Ocn. A la fecha se reporta que la Ocn regularía el metabolismo energético aumentando la proliferación de células ` pancreáticas, y la secreción de insulina y de adiponectina. Sobre el músculo esquelético actuaría favoreciendo la absorción y el catabolismo de nutrientes. La función reproductiva masculina estaría regulada mediante el estímulo a las células de Leydig para sintetizar testosterona; en el desarrollo cerebral y la cognición, la Ocn aumentaría la síntesis de neurotransmisores monoaminados y disminuiría el neurotransmisor inhibidor GABA. Si bien son indispensables mayores evidencias para dilucidar los mecanismos reguladores por medio de los cuales actuaría la Ocn, los resultados enumerados en los distintos estudios experimentales establecen la importancia de este novedoso integrante molecular. Dilucidar su rol dentro de estos procesos interrelacionados en seres humanos abriría la posibilidad de utilizar a la Ocn en el tratamiento de enfermedades endocrino-metabólicas. (AU)

Osteological !ndings have intensi!ed in recent years. The skeleton behaves as an endocrine secretion organ that synthesizes at least two hormones: osteocalcin (Ocn) and !broblast growth factor 23 (FGF-23). Ocn is a small peptide that contains 3 glutamic acid residues. After translation, these residues are carboxylated to make possible its retention into the bone matrix. Decarboxylation on the !rst glutamic acid residue (GluOcn) has been reported to have biological effects. Bone resorption is the key mechanism for its bioactivation. This review focuses on current knowledge on Ocn hormonal function. It has been reported that Ocn regulates energy metabolism by increasing the proliferation of pancreatic ` cells, and the secretion of insulin and adiponectin. On the skeletal muscle, it may act by favoring the absorption and catabolism of nutrients. Male reproductive function might be regulated by stimulating Leydig cells to synthesize testosterone. Regarding brain development and cognition, Ocn would increase monoamine neurotransmitters synthesis and decrease inhibitory neurotransmitter GABA. Although more evidence is needed to elucidate the regulatory mechanisms of Ocn, different experimental studies establish the importance of this novel molecular mediator. Clarifying its role within interrelated processes in humans, might open the possibility of using Ocn in different treatments of endocrine-metabolic diseases. (AU)

Immunohistochemical study of aquaporin 1 and 2 in the reproductive tract of the bactrian camel (Camelus bactrianus) / Estudio inmunohistoquímico de acuaporina 1 y 2 en el tracto reproductivo del camello bactriano (Camelus bactrianus)

Spermatogenesis is associated with considerable fluid secretion or absorption in the male reproductive tract. Aquaporins (AQPs) are membrane protein channels that allow the rapid movement of water through epithelium. In the present study, immunohistochemistry was utilized to localize the expression of AQP 1, AQP2 in the testis and prostate of adult bactrian camel (Camelus bactrianus). Results show that AQP1 have intense reaction in rete testis, efferent ducts, vessels, seminiferous duct and in the prostate, AQP2 was found minor expression in the rete testis, vessels and prostate, which suggesting that AQP1 may have the main role in the absorption of the large amount of testicular fluid in male camel reproductive tract. Investigations of AQPs biology in camel could be relevant with technologies for assisted procreation in animal husbandry and aquaculture.

La espermatogénesis se asocia con la secreción de una cantidad considerable de líquido o absorción en el tracto reproductor masculino. Las acuaporinas (ACPs) son canales de proteínas de membrana que permiten el movimiento rápido de agua a través del epitelio. En el presente estudio, se utilizó inmunohistoquímica para localizar la expresión de ACP 1, ACP2 en el testículo y la próstata del camello bactriano adulto (Camelus bactrianus). Los resultados muestran que ACP1 tiene una reacción intensa en la rete testis, conductos eferentes, vasos, conductos seminíferos y en la próstata. La expresión ACP2, de menor importancia, se observó en la rete testis, vasos y próstata, lo que sugiere que ACP1 puede tener el papel principal en la absorción de gran cantidad de líquido testicular en el tracto reproductivo masculino del camello. Las investigaciones de la biología del ACP en camello podrían ser relevantes para las tecnologías de reproducción asistida de la ganadería y la acuicultura.

Estrogen receptors and function in the male reproductive system: [review] / Receptores e função do estrógeno no sistema reprodutor masculino: [revisão]

A substantial advance in our understanding on the estrogen signaling occurred in the last decade. Estrogens interact with two receptors, ESR1 and ESR2, also known as ERα and ERβ, respectively. ESR1 and ESR2 belong to the nuclear receptor family of transcription factors. In addition to the well established transcriptional effects, estrogens can mediate rapid signaling, triggered within seconds or minutes. These rapid effects can be mediated by ESRs or the G protein-coupled estrogen receptor GPER, also known as GPR30. The effects of estrogen on cell proliferation, differentiation and apoptosis are often mediated by growth factors. The understanding of the cross-talk between androgen, estrogen and growth factors signaling pathways is therefore essential to understand the physiopathological mechanisms of estrogen action. In this review we focused on recent discoveries about the nature of the estrogen receptors, and on the signaling and function of estrogen in the male reproductive system.

Durante a última década, ocorreu um avanço substancial no conhecimento da sinalização do estrógeno. Estrógenos interagem com dois receptores, ESR1 e ESR2, também conhecidos como ERα e ERβ, respectivamente. ESR1 e ESR2 pertencem à família de receptores nucleares, que funcionam como fatores de transcrição. Além dos bem estabelecidos efeitos transcricionais, os estrógenos medeiam a sinalização rápida, desencadeada dentro de segundos ou minutos. Esses efeitos rápidos podem ser mediados por ESRs ou pelo receptor de estrógeno acoplado à proteína G, GPER, também conhecido como GPR30. Os efeitos de estrógenos sobre a proliferação celular, diferenciação e apoptose são, muitas vezes, mediados por fatores de crescimento. Portanto, a compreensão da interação entre as vias de sinalização de andrógeno, estrógeno e fatores de crescimento é essencial para entender os mecanismos fisiopatológicos envolvidos na ação estrogênica. Nesta revisão, foram abordadas descobertas recentes sobre a estrutura dos receptores, a sinalização e a função do estrógeno no sistema reprodutor masculino.

Androgens and the male reproductive tract: an overview of classical roles and current perspectives: [review] / Androgênios e o trato reprodutor masculino: ações clássicas e perspectivas atuais: [revisão]

Androgens are steroid hormones that play key roles in the development and maintenance of male phenotype and reproductive function. These hormones also affect the function of several non-reproductive organs, such as bone and skeletal muscle. Endogenous androgens exert most of their effects by genomic mechanisms, which involve hormone binding to the androgen receptor (AR), a ligand-activated transcription factor, resulting in the modulation of gene expression. AR-induced non-genomic mechanisms have also been reported. A large number of steroidal and non-steroidal AR-ligands have been developed for therapeutic use, including the treatment of male hypogonadism (AR agonists) and prostate diseases (AR antagonists), among other pathological conditions. Here, the AR gene and protein structure, mechanism of action and AR gene homologous regulation were reviewed. The AR expression pattern, its in vivo regulation and physiological relevance in the developing and adult testis and epididymis, which are sites of sperm production and maturation, respectively, were also presented.

Os androgênios são hormônios esteroides com papel fundamental no desenvolvimento e na manutenção do fenótipo masculino e da função reprodutiva. Esses hormônios também afetam a função de diversos tecidos não reprodutivos, como, por exemplo, o ósseo e musculoesquelético. Os androgênios endógenos exercem a maioria de suas funções por mecanismo genômico, que envolve a ligação do hormônio ao receptor de androgênio (RA), um fator de transcrição ativado por ligante, o que resulta no controle da expressão gênica. Mecanismos não genômicos também têm sido associados aos efeitos induzidos pelo RA. Um grande número de ligantes do RA, esteroidais e não esteroidais, tem sido desenvolvido para o uso terapêutico, incluindo o tratamento do hipogonadismo masculino (agonistas do RA) e de doenças da próstata (antagonistas do RA), entre outras condições patológicas. Neste trabalho, foram discutidas as características estruturais básicas do RA (gene e proteína), os mecanismos de ação desse receptor, bem como aspectos relacionados à sua regulação homóloga. O padrão de expressão do RA, sua regulação in vivo e relevância fisiológica durante o desenvolvimento e a vida adulta na função do testículo e epidídimo, tecidos responsáveis pela produção e maturação de espermatozoides, respectivamente, também foram discutidos.

Estereología comparativa entre las glándulas del complejo prostático del conejo Oryctolagus cunniculus / Comparative stereology between the glands of the prostatic complex in the rabbit Oryctolagus cunniculus

El objetivo del estudio fue determinar algunos parámetros estereológicos de las glándulas que conforman el complejo prostático en el conejo y así, sentar las bases para estudios morfofuncionales. Se utilizaron 5 conejos (Oryctolagus cuniculus), machos, adultos y clínicamente sanos, mantenidos en el Bioterio de la Facultad de Medicina de la Universidad de La Frontera, Temuco, Chile. Fue disecada la región pélvica y se aisló el complejo prostático de las otras glándulas anexas. Las muestras fueron fijadas en Bouin, durante 24 horas y procesadas para su inclusión en paraplast. Se realizaron cortes seriados de 5 Jm de espesor, los cuales fueron teñidos con hematoxilina eosina, para su análisis estéreo lógico. Los resultados mostraron que el complejo prostático del conejo está formado por 4 glándulas: próstata (craneal a la glándula vesicular), propróstata (caudal a la glándula vesicular y craneal a la próstata) y dos parapróstata (inferiores y lateralmente situadas a la propróstata). El promedio de células glandulares en la próstata fue de 7,3 x 10(6)/ mm³ (D. E. 1,8 x 10(6)); en la propróstata fue de 10,33 x 10(6)/ mm³ (D. E. 2,45 x 10(6)); en la parapróstata derecha fue de 13,57 x 10(6)/ mm³ (D. E. 2,84 x 10(6)) y en la parapróstata izquierda fue de 11,91 x 10(6)/mm³ (D. E. 2,97 x 10(6)).E1 porcentaje promedio de células glandulares en la próstata fue de 14,12 por ciento (D. E. 3,01); en la propróstata fue de 13,56 por ciento (D. E. 3,13); en la parapróstata derecha fue de 18,80 por ciento (D. E. 3,04) y en la parapróstata izquierda de 18,59 por ciento (D. E. 3,43). Las glándulas del complejo prostático presentan diferencias morfológicas entre sí y, en especial, en sus aspectos estereológicos, siendo las parapróstatas las que presentaron un mayor número de células glandulares y mayor porcentaje de tejido glandular (semejante a la glándula bulbouretral), lo que podría indicar que cada una de las glándulas de este complejo cumple roles funcionales...

The aim of this study was to determine some stereological parameters of the glands of the prostatic complex in the rabbit and thereby setting the basis for future morphofunctional studies. Five rabbits (Oryctolagus cuniculus), males, adults, clinically healthy and mantained in the Biotery of the Faculty of Medicine of the Universidad de La Frontera, Temuco, Chile, were used. The pelvic region was dissected and the prostatic complex of the other glands was isolated. The samples were fixed in Bouin solution for 24 hours and processed for inclusion in paraplast. Serial cuts of 5mm which were stained with hematoxilin eosin for stereological analysis. The results showed that the prostatic complex of the rabbit was composed of four glands: prostate (cranial to vesicular gland), proprostate (caudal to vesicular gland and cranial to the prostate) and two paraprostates (inferior and lateral to the prostate). The average of the glandular cells in the prostate was 7,3 x 107 mm³ (S. D. 1,8 x 10s); in the proprostate was 10,33 x 107 mm³ (S. D. 2,45 x 10s); in the right paraprostate was 13,57 x 107 mm³ (S. D. 2,84 x 10s) and in the left paraprostate was 11,91 x 107 mm³ (S. D. 2,97 x 10s). The percentage average of the glandular cells in the prostate was 14,12 percent (S. D. 3,01); in the proprostate was 13,56 percent (S. D. 3,13); in the right paraprostate was 18,80 percent (S. D. 3,04) and in the left paraprostate was 18,59 percent (S. D. 3,43). The gland of the prostatic complex show morphological differences among themselves and in particular, its stereological aspects, with paraprostates which showed an increased number of glandular cells and higher percentage of glandular tissue ( similar to the bulbourethral gland), which could indicate that each of the glands of this complex plays specific functional roles in the reproductives processes.