Effect of indoxyl sulfate on the morphology and function of the thyroid gland - ex vivo studies in rabbits

Indoxyl sulfates are uremic indolic toxins known to participate in the pathogenesis of cardiovascular diseases during chronic kidney disease in humans and some animal species. However, nothing is known about the indoxyl sulfate effect on the thyroid gland which is especially responsible for the general organism metabolism. This study determines the morpho-functional status of the thyroid gland after exposure to indoxyl sulfate (10, 25, and 50 mM) with the use of an ex vivo system and rabbit (n=10) as an experimental model thyroid gland histology, immunoexpression of thyrotropin receptor (TSHR), and concentrations of thyroxine (T4) and triiodothyronine (T3) were evaluated. Statistical analyses were performed using one-way analysis of the variance (ANOVA) followed by Tukey's post hoc comparison test. Minor alterations in thyroid tissue structure e.g. very rare exfoliated epithelial cells, condensed colloid fluid, or slight loosening of the epithelium were found. In addition, modulated dose dependent-expression of TSHR (p<0.01, p<0.001) together with a decreased level of T4 and T3 (p<0.001, p<0.01) exception of an increased level of T4 after the middle dose of indoxyl sulfate were revealed. We report here, for the first time, that indoxyl sulfate affects the thyroid gland mainly at the molecular level. The rabbit thyroid gland ex vivo system seems to be suitable for further studies on the thyroid gland in health and disease. However, the effect of TSH-TSHR signaling at ultrastructural, and epigenetic levels needs supplementary appraisal.

Next-Generation Sequencing analysis discloses genes implicated in equine endometrosis that may lead to tumorigenesis

Endometrosis is a periglandular fibrosis associated with dysfunction of affected glandular epithelial cells that is the most common cause of reduced fertility in mares, although it is not fully understood. The etiology of the disease is still partially unknown. This study focuses on understanding the genetic mechanisms potentially underlying endometrosis in mares using the Next Generation Sequencing (NGS) technique. Endometrial samples, used in the study, were obtained in the anestrus phase both from healthy mares and those diagnosed with endometrosis. The NGS data were analyzed for gene involvement in biological processes and pathways (e.g. STAR, KOBAS-I, STRING, and ClustVis software). Bioinformatic analysis revealed differential expression of 55 transcripts. In tissues with endometrosis, most genes displayed upregulated expression. The protein-protein interaction analysis disclosed a substantial transcript network including transcripts related to metabolism e.g. sulfur metabolism (SELENBP1), ovarian steroidogenesis, steroid hormone biosynthesis, and chemical carcinogenesis (CYP1B1), COXs (COX4I1, COX3, UQCRFS1) as well as transcripts related to immune response e.g. MMP7, JCHAIN, PIGR, CALR, B2M, FCGRT. Interestingly, the latter has been previously linked with various pathologies including cancers in the female reproductive system. In conclusion, this study evaluated genes that are not directly impacted by sex hormone feedback, but that create a metabolic and immune environment in tissues, thus influencing fertility and pregnancy in mares with endometrosis. Moreover, some of the identified genes may be implicated in tumorigenesis of endometrial lesions. These data may be useful as a starting point in further research, such as the development of targeted strategies for rapid diagnosis and/or prevention of this pathology based on gene and protein-protein interactions.

Leydig Cells in Immunocastrated Polish Landrace Pig Testis: Differentiation Status and Steroid Enzyme Expression Status

Porker immunocastration against gonadoliberin (GnRH) secretion has been utilized since 2009; however, consumers are still skeptical of it. This is due to not having full information available on the problem of a boar taint, as well as a lack of research on morphological and molecular changes that may occur in the animal reproductive system and other body systems. The present study aimed to explore the functional status of steroidogenic Leydig cells of the testicular interstitial tissue in immunocastrated Polish Landrace pigs. Analyses were performed using Western blot, immunohistochemistry for relaxin (RLN), insulin-like 3 protein (INSL3), pelleted growth factor receptor α (PDGFRα), cytochrome P450scc, 3β- and 17β-hydroxysteroid dehydrogenases (3β-HSD, 17β-HSD), cytochrome P450arom, and 5α-reductase (5α-RED). Immunoassay ELISA was used to measure the androstenone, testosterone, and estradiol levels in the testis and serum of immunocastrates. We revealed disturbances in the distribution and expression of (i) RLN, indicating an inflammatory reaction in the interstitial tissue; (ii) INSL3 and PDGFRα, indicating alterations in the differentiation and function of fetal, perinatal, or adult Leydig cell populations; (iii) P450scc, 3β-HSD, 17β-HSD, P450arom, and 5α-RED, indicating disturbances in the sex steroid hormone production and disturbed functional status of Leydig cells; as well as (iv) decreased levels of androstenone, testosterone, and estradiol in testicular tissue and serum, indicating the dedicated action of Improvac to reduce boar taint at both the hypothalamic-hypophysis-gonadal axis and local level (Leydig cells). In summary, our study provides a significant portion of knowledge on the function of Leydig cells after immunocastration, which is also important for the diagnosis and therapy of testis dysfunction due to GnRH action failure and/or Leydig cell differentiational-functional alterations.

Abundance of estrogen receptors involved in non-canonical signaling in the dog testis

With estrogen regulation of the reproductive system, G-protein-coupled membrane estrogen receptor (GPER) and estrogen-related receptors (ERRs) are implicated. Non-canonical receptors can bind estrogens such as environmental and pharmacological chemicals. These compounds induce rapid non-genomic pathways or receptor interaction including autoactivation. Testicular tumors occur in dogs more frequently than in other domestic animals. Also, in recent decades there were increased occurrences of various tumor types in dogs. Using qRT-PCR, Western blot and immunohistochemistry procedures in the present study, there was determination of abundance pattern of GPER, ERRα, β and γ in dog tests when there were intratubular germ cell tumors. There was quantitation of estradiol, cyclic GMP and calcium ions (Ca2⁺). There were changes (P < 0.01; P < 0.001) in GPER, ERRα and β in both mRNA transcript and protein abundances including less (P < 0.001) co-abundance of ERRγ mRNA transcript and protein. Receptors were mainly located in Leydig cells with there being receptor delocalization to the cell cytoplasm or occasionally detections in the seminiferous tubule epithelia, especially of testicular tumor tissues. There were also greater estradiol (P < 0.05) and lesser cGMP and Ca2⁺ concentrations in testicular tumor tissues indicating there was a disrupted sex steroid milieu and tumor cell metastasis. Results from the present study provide further evidence that ERRγ has marked actions in testicular germ cell tumor initiation and development and in further structural-functional disruptions of dog testis. Concomitantly, abundance pattern of GPER and ERRs, relative to concentrations of cGMP and Ca2⁺, may be an additional indicator of intratubular germ cell tumors in dogs.

Senescence and adiponectin signaling - Studies in canine testis

BACKGROUND

The meaning of senescence for tissue physiological and pathological conditions is poorly known. Based on initial reports especially proteins and mechanisms that regulate this process are necessary to be determinate.

METHODS

The main aim of the study was to investigate the presence of senescent cells in canine testicular tissue (mixed breed testes; n = 60) in relation to adiponectin signaling. In detail, new information on the senescence cell number, as well as senescence and adiponectin signaling mechanisms in cryptorchid and germ cell tumor testes were provided with the use of immunohistochemical and colorimetric analyses.

RESULTS

Comparison of immunohistochemical results, in cryptorchid and tumor testes revealed increased number of senescent cells (p16 and γH2AX markers). Increased expression of adiponectin and adiponectin receptor 1, as well as extracellular signal-activated kinase (ERK1/2) in pathological testes were detected. In addition, decreased cholesterol and increased testosterone levels in tumor testis were found.

CONCLUSION

The present study is the first to demonstrate the presence as well as the differences that exist in senecent cell number in mixed breed dog testes with cryptorchidism and germ cell tumor. Altered expression of adiponectin signaling and ERK1/2 signaling pathways together with altered cholesterol and testosterone levels reflect important senescence role in disturbed functions of canine testis. Moreover, the application of studied here senescence regulating molecules for detection and prevention against pathologies of the male gonad should be furtherly considered.

Implication of Membrane Androgen Receptor (ZIP9) in Cell Senescence in Regressed Testes of the Bank Vole

Here, we studied the impact of exposure to short daylight conditions on the expression of senescence marker (p16), membrane androgen receptor (ZIP9) and extracellular signal-regulated kinase (ERK 1/2), as well as cyclic AMP (cAMP) and testosterone levels in the testes of mature bank voles. Animals were assigned to groups based on an analysis of testis diameter, weight, seminiferous tubule diameter and the interstitial tissue area: group 1, not fully regressed (the highest parameters); group 2 (medium parameters); or group 3, regressed (the lowest parameters). Cells positive for p16 were observed only in the seminiferous tubule epithelium. However, in groups 1 and 2, these were mostly cells sloughed into the tubule lumen. In group 3, senescent cells resided in between cells of the seminiferous epithelium. Staining for ZIP9 was found in Sertoli cells. Western blot analysis showed a trend towards a decreased expression of p16 and ZIP9 in the testes of the voles in groups 2 and 3, compared to group 1. In addition, a trend towards an increased expression of ERK, as well as an increase of cAMP and testosterone levels, was revealed in group 2. In the regressed testes, a functional link exists between senescence and androgen levels with implication of ZIP9 and cAMP/ERK signaling pathways.