Is membrane androgen and estrogen receptor signaling imperative in the governing function of the adrenal cortex in the Eurasian beaver (Castor fiber L.)?

There is a need to fully know the physiology of Eurasian beaver due to its essential role in environmental homeostasis. However, a "human factor" impacts this, including stress conditions and environmental pollution. Adrenal glands protect these all. The regulation of endocrine processes by nonclassical androgen and estrogen signaling, the first and fastest control, is still a matter of research. The specific analyses performed here in mature female and male beaver adrenals contained: anatomical and histological examinations, expression and localization of membrane androgen receptor (zinc transporter, Zinc- and Iron-like protein 9; ZIP9) and membrane estrogen receptor coupled with G protein (GPER), and measurement of zinc (Zn2+) and copper (Ca2+) ion levels and corticosterone levels. We revealed normal anatomical localization, size, and tissue histology in female and male beavers, respectively. Equally, ZIP9 and GPER were localized in the membrane of all adrenal cortex cells. The protein expression of these receptors was higher (p < 0.001) in male than female adrenal cortex cells. Similarly, Zn2+ and Ca2+ ion levels were higher (p < 0.05, p < 0.01) in male than female adrenal cortex. The increased corticosterone levels (p < 0.001) were detected in the adrenal cortex of females when compared to males. The present study is the first to report the presence of nonclassical androgen and estrogen signaling and its possible regulatory function in the adrenal cortex of Eurasian beavers. We assume that this first-activated and fast-transmitted regulation can be important in the context of the effect of environmental physical and chemical stressors especially on adrenal cortex cells. The beaver adrenals may constitute an additional supplementary model for searching for universal mechanisms of adrenal cortex physiology and diseases.

The uterusmasculinus of the Eurasian beaver (Castor fever L.) - The appraisal of fast hormone regulation by membrane androgen and estrogen receptors involvement.

The phenomenon of remaining paramesonephric ducts (uterus masculinus) in males of some animal species concerning its role is still an unresolved issue. Now it is well-recognized that sex hormonal regulation of reproductive physiology involves also fast nongenomic control of cellular processes through noncanonical signaling. Herein, in the uterus masculinus of Eurasian beaver membrane androgen receptor (metal ion transporter Zrt- and Irt-like protein 9; ZIP9) and membrane estrogen receptor (G protein-coupled estrogen receptor; GPER) were studied. Scanning electron microscopy together with anatomical analysis revealed that Eurasian male beavers possess one double uterus (uterus duplex). Two odd parts open into the vagina but do not form a common lumen. The length of the horns is the most differential feature of this organ in studied animals. Uterus masculinus is not a tightly closed tubular structure. Histological analysis showed an analogy to the female uterus structure however no glands but gland-like structures were observed. The presence and abundant localization of ZIP9 and GPER proteins in cells of uterus masculinus was confirmed by immunohistochemistry while their expression was measured by western blotting. GPER expression in remnants was lower (P < 0.001) than those in the female uterus. Parallelly, the concentration of progesterone and estradiol but not testosterone was lower (P < 0.05 and P < 0.01, respectively) in comparison to the female uterus. Our study, for the first time, reports the involvement of fast hormonal regulation in the uterus masculinus of Eurasian beavers reflecting the participation of this organ in the creation local hormonal environment. Moreover, the uterus masculinus seems to be a useful research model for understanding and resolving urgent biological problems such as gender identities and having children by women with a lack of uterus or anatomical barriers on this level.

Towards understanding leydigioma: do G protein-coupled estrogen receptor and peroxisome proliferator-activated receptor regulate lipid metabolism and steroidogenesis in Leydig cell tumors?

Leydig cell tumors (LCT) are the most common type of testicular stromal tumor. Herein, we investigate the G protein-coupled estrogen receptor (GPER) and peroxisome proliferator-activated receptor (PPAR) implication in regulation of lipid homeostasis including the expression of steroidogenesis-controlling molecules in clinical specimens of LCTs and tumor Leydig cells (MA-10). We showed the general structure and morphology of LCTs by scanning electron and light microscopy. In LCTs, mRNA and protein analyses revealed increased expression of GPER and decreased expression of PPARα, ß, and γ. Concomitantly, changes in expression pattern of the lutropin receptor (LHR), protein kinase A (PKA), perilipin (PLIN), hormone sensitive lipase (HSL), steroidogenic acute regulatory protein (StAR), translocator protein (TSPO), HMG-CoA synthase, and reductase (HMGCS, HMGCR) were observed. Using MA-10 cells treated with GPER and PPAR antagonists (alone and in combination), we demonstrated GPER-PPAR-mediated control of estradiol secretion via GPER-PPARα and cyclic guanosine monophosphate (cGMP) concentration via GPER-PPARγ. It is assumed that GPER and PPAR can crosstalk, and this can be altered in LCT, resulting in a perturbed lipid balance and steroidogenesis. In LCTs, the phosphatidylinositol-3-kinase (PI3K)-Akt-mTOR pathway was disturbed. Thus, PI3K-Akt-mTOR with cGMP can play a role in LCT outcome and biology including lipid metabolism.

The meaning of non-classical estrogen receptors and peroxisome proliferator-activated receptor for boar Leydig cell of immature testis.

Communication in biological systems involves diverse-types of cell-cell interaction including cross-talk between receptors expressed by the target cells. Recently, novel sort of estrogen receptors (G protein - coupled estrogen receptor; GPER and estrogen-related receptor; ERR) that signal directly via estrogen binding and/or via mutual interaction-regulated estrogen signaling were reported in various organs including testis. Peroxisome proliferator - activated receptor (PPAR) is responsible for maintaining of lipid homeostasis that is critical for sex steroid production in the testis. Here, we investigated the role of interaction between GPER, ERRß and PPARγ in steroidogenic Leydig cells of immature boar testis. Testicular fragments cultured ex vivo were treated with GPER or PPARγ antagonists. Then, cell ultrastructure, expression and localization of GPER, ERRß, PPARγ together with the molecular receptor mechanism, through cyclic AMP and Raf/Ras/extracellular signal activated kinases (ERK), in the control of cholesterol concentration and estrogen production by Leydig cells were studied. In the ultrastructure of antagonist-treated Leydig cells, mitochondria were not branched and not bifurcated as they were found in control. Additionally, in PPARγ-blocked Leydig cells changes in the number of lipid droplets were revealed. Independent of used antagonist, western blot revealed decreased co-expression of GPER, ERRß, PPARγ with exception of increased expression of ERRß after PPARγ blockage. Immunohistochemistry confirmed presence of all receptors partially located in the nucleus or cytoplasm of Leydig cells of both control and treated testes. Changes in receptor expression, decreased cholesterol and increased estradiol tissue concentrations occurred through decreased cAMP level (with exception after GPER blockage) as well as Raf/Ras/ERK pathway expression. These all findings indicate that GPER-ERRß-PPARγ interaction exists in immature boar testis and regulates Leydig cell function. Further detailed studies and considerations on GPER-ERRß-PPARγ as possible diagnosis/therapy target in disturbances of testis steroidogenic function are needed.

Serum amyloid A protein (SAA), haptoglobin (Hp) and selected hematological and biochemical parameters in wild mares before and after parturition.

The aim of the study was to evaluate physiological changes in hematological and biochemical parameters in mares in perinatal period. Blood samples were collected from 24 pregnant Polish Konik breed mares which were divided into two groups. The first group (Group - I, n=12) comprised mares living in the wild, in the reserve. The second group (Group - II, n=12) consisted of mares kept in stables. The blood was collected 2 weeks prior to the parturition, then 24 hours after the delivery, and then at the 7th and 21st day after foaling. When comparing the two groups before the parturition, no significant differences in terms of WBC, RBC, and Hb were found, however, there was a significant difference in MCV, MCH, LYM, NEU and SEG NEU (p≤0.05). In Group II, 24 hours after the parturition and at the 21st day after foaling, a significant raise in WBC, NEU and SEG NEU (p≤0.05) was detected. No significant differences in serum concentrations of proteins such as TP, Alb or Glb were observed. As to acute phase proteins, significant rise in SAA and Hp (p≤0.05) was found in the two examined groups 24 hours after the parturition. Yet, this rise remained within physiological range. The study revealed a certain degree of fluctuations in hematological parameters, in serum concentrations of acute-phase proteins and total proteins in the mares in the perinatal period. However, these changes remained still within physiological ranges and thus they do not indicate potential susceptibility to disorders of perinatal period.

The hypoglossal nuclear complex in reindeer.

The hypoglossal complex has an ovoid shape and is largest at the level of obex. Caudally to the obex is 2/3 of the complex. The complex is divided into 4 groups. Sublingual nucleus of Roller presents a narrow strip of cells located ventrally to the middle part of hypoglossal nucleus. Laterally to obex is the paramedian nucleus of Jacobson in the form of short, narrow band. Posteriorly to Jacobson's nucleus is the intercalated nucleus of Staderini. Constinuation of the hypoglossal nucleus is the nucleus prepositus of Marburg.