Influence of hormonal imbalance on the integrity of seminiferous epithelium in the testes of adult rats chronically exposed to letrozole and rats exposed to soya isoflavones during the prenatal period, lactation, and up to sexual maturity

The structural integrity of the germ cells in the seminiferous epithelium and the correct process of spermatogenesis are made possible by proteins that participate in the formation of different types of junctions. This study was performed on samples of the testes of 4 groups (2 experimental and 2 corresponding control) of male Wistar rats. In the first experimental group, the adult rats received letrozole - a nonsteroidal inhibitor of cytochrome P450 aromatase (P450arom). The second experimental group was exposed to soya isoflavones during the prenatal period, lactation, and up to sexual maturity. The aim of this study was to examine the immunoexpression of β-catenin, N-cadherin, occludin, connexin43, annexin V, and advanced glycation end products (AGE) in the seminiferous epithelium of rat testes with chronic estrogen deficiency and of rats exposed to soya isoflavones. Series of sections of the testes were stained using PAS and silver impregnation. Moreover, immunohistochemistry tests were performed. A semi-quantitative determination of protein immunoexpression was performed using Image J. The number of annexin V positive Sertoli cells per tubule were counted manually. Comparisons between the experimental and corresponding control groups were performed using a non-parametric Mann-Whitney U test. The most common alterations were prematurely sloughed germ cells in the lumen of the seminiferous tubules and invaginations of the seminiferous tubules. We observed a lower number of annexin V positive Sertoli cells and a lower expression of N-cadherin and occludin in the seminiferous epithelium of both groups of rats with hormonal imbalances. Moreover, a higher expression of AGE, a lower expression of connexin 43 and a lower amount of reticular fibers in the basal lamina of seminiferous tubules was present in rats treated with letrozole and a higher expression of β-catenin was found in rats exposed to soya isoflavones. The hormonal imbalance between androgens and estrogens resulted in a decreased number of annexin V positive Sertoli cells. This may be associated with a failed clearance of apoptotic germ cells that leads to disturbances in the blood-testis-barrier (BTB) by affecting the expression of junctional proteins in the seminiferous epithelium. Moreover, a decreased level of estrogens was also associated with an increased expression of AGEs and with a changed composition of basal lamina in the seminiferous tubules of rats. These changes could lead to germ cell sloughing and invaginations of the seminiferous tubules.

Modulatory effect of inulin with soya isoflavones on plasma lipid profile and liver SCD-18 index in rats with induced type-2 diabetes mellitus

Obesity and type-2 diabetes are often associated with nonalcoholic fatty liver disease (NAFLD). Soya isoflavones act as antidiabetic agents and protect against NAFLD. There are data suggesting that inulin may increase the plasma concentration and effect of soya isoflavones. The aim of the present study was to compare the effect of soya isoflavones, as opposed to the effect of soya isoflavones with inulin, on plasma lipid profile, liver morphology, and liver fatty acids in rats with induced type-2 diabetes mellitus. Data were collected on thirty-six male Sprague-Dawley rats divided into control and diabetic groups. Animals in the diabetic (DM) group were on a high-fat diet and were injected with low doses of streptozotocin. Animals in the control groups were fed a regular diet and were injected with a buffer. After the injections, the animals were divided into three groups of nondiabetic rats (nDM)-controls (c-nDM), rats treated with isoflavones (IS-nDM), and rats treated with isoflavones plus inulin (IS+IN-nDM)-and three parallel diabetic (DM) subgroups: controls (c-DM), rats treated with isoflavone (IS-DM), and rats treated with isoflavones plus inulin (IS+IN-DM). Hepatic steatosis and fibrosis were examined using hematoxylin-eosin staining and Mallory's trichrome methods respectively. Liver fatty acids were extracted and analyzed by gas chromatography. A lipid blood test was performed. The study showed significant changes in liver fatty acids, liver morphology, and plasma lipid profile. The estimated SCD-18 index significantly decreased in both the control and DM groups after isoflavone supplementation. The level of liver steatosis and fibrosis also decreased after isoflavone supplementation in the DM groups. The plasma lipid profile showed increased levels of HDL-C after isoflavone supplementation in the DM groups. These results support the protective use of isoflavones in liver steatosis and as beneficial to plasma lipid profile in individuals with diabetes. A novelty of this work is its comparison of supplementation using soya isoflavones with supplementation using both soya isoflavones and inulin. Surprisingly, additional supplementation with inulin modulates the positive effect of isoflavones.

Morphologic Changes in the Dermis After the Single Administration of Autologous Fibroblastic Cells: A Preliminary Study

BACKGROUND

Aging is a multifactorial process defined by an accumulation of damage in all tissues and organs, including the skin, throughout the lifespan of an individual. The reduction of both cellular and extracellular matrix components of the dermis during the aging process is followed by the alteration of the morphology of the skin tissue. This study was conducted to assess skin morphology in men before and 3 months after the intradermal injection of autologous fibroblastic cells.

METHODS

Tissue biopsies were surgically obtained before and 3 months after the treatment with autogenously harvested fibroblasts expanded in vitro, as well as after injection of phosphate-buffered saline. The thickness of collagen fiber bundles and number of fibroblasts in the dermis were analyzed in morphometric studies. The morphologic evaluation, using different methods of staining has been performed to analyze of extracellular matrix proteins, including collagen and reticular fibers, fibrillin-1-rich microfibrils, elastic fibers, and hyaluronic acid.

RESULTS

After administration of the cells, we found a noticeable increase in the number of fibroblasts within the dermis, a significant enlargement in diameter of the collagen fiber bundles, and an improvement in the density of reticular fibers, fibrillin-1-rich microfibrils, and elastic fibers compared with the initial, steady-state condition.

CONCLUSIONS

The administration of autogenous fibroblasts could be an effective and safe adjunctive therapy to conventional health care treatment to prevent and reduce the age-related accumulation of dermal tissue damage.

Perinatal exposure to lead induces morphological, ultrastructural and molecular alterations in the hippocampus

The aim of this paper is to examine if pre- and neonatal exposure to lead (Pb) may intensify or inhibit apoptosis or necroptosis in the developing rat brain. Pregnant experimental females received 0.1% lead acetate (PbAc) in drinking water from the first day of gestation until weaning of the offspring; the control group received distilled water. During the feeding of pups, mothers from the experimental group were still receiving PbAc. Pups were weaned at postnatal day 21 and the young rats of both groups then received only distilled water until postnatal day 28. This treatment protocol resulted in a concentration of Pb in rat offspring whole blood (Pb-B) below the threshold of 10 μg/dL, considered safe for humans.We studied Casp-3 activity and expression, AIF nuclear translocation, DNA fragmentation, as well as Bax, Bcl-2 mRNA and protein expression as well as BDNF concentration in selected structures of the rat brain: forebrain cortex (FC), cerebellum (C) and hippocampus (H). The microscopic examinations showed alterations in hippocampal neurons.Our data shows that pre- and neonatal exposure of rats to Pb, leading to Pb-B below 10 μg/dL, can decrease the number of hippocampus neurons, occurring concomitantly with ultrastructural alterations in this region. We observed no morphological or molecular features of severe apoptosis or necrosis (no active Casp-3 and AIF translocation to nucleus) in young brains, despite the reduced levels of BDNF. The potential protective factor against apoptosis was probably the decreased Bax/Bcl-2 ratio, which requires further investigation. Our findings contribute to further understanding of the mechanisms underlying Pb neurotoxicity and cognition impairment in a Pb-exposed developing brain.

Soy isoflavones administered pre- and postnatally may affect the ERα and ERβ expression and elements' content in bones of mature male rats

The aim of this study was to assess the influence of soy isoflavones, administered pre- and later postnatally, on the estrogen receptor α (ERα) and β (ERβ) expression in bones and to examine the mineral metabolism of the skeletal system in male rats. In bones, ERs were examined with an immunohistochemical method; in blood, estradiol with chemiluminescence immunoassay and in blood and bones, calcium and magnesium with atomic absorption spectrometry and fluorides with a potentiometric method were examined. Decreased immunoexpression of ERα and the increased intensity of immunofluorescence of ERβ in osteocytes in the femur of experimental rats were observed. In the serum of treated rats, a significantly higher concentration of estradiol and lower calcium were observed. The content of magnesium and fluoride were significantly higher in the bones of the examined animals. The data presented show that pre- and postnatal supplementation of male rats with soy isoflavones may considerably increase the concentration of estrogens in serum, with a concurrent effect on the mineral composition of bones.

Altered energy status of primary cerebellar granule neuronal cultures from rats exposed to lead in the pre- and neonatal period

This paper examines the effect of pre- and neonatal exposure of rats to lead (0.1% lead acetate in drinking water, resulting in rat offspring whole blood lead concentration (Pb-B) 4μg/dL) on the energy status of neuronal mitochondria by measuring changes in ATP, ADP, AMP, adenosine, TAN concentration, adenylate energy charge value (AEC) and mitochondrial membrane potential in primary cerebellar granule neurons (CGC) in dissociated cultures. Fluorescence studies were performed to imaging and evaluate mitochondria mass, mitochondrial membrane potential, intracellular and mitochondrial reactive oxygen species (ROS) production. The Na(+)/K(+) ATPase activity in intact CGC was measured spectrophotometrically. Our data shows that pre- and neonatal exposure of rats to Pb, even below the threshold of whole blood Pb value considered safe for people, affects the energy status of cultured primary cerebellar granule neurons through a decrease in ATP and TAN concentrations and AEC value, inhibition of Na(+)/K(+) ATPase, and increase in intracellular and mitochondrial ROS concentration. These observations suggest that even these low levels of Pb are likely to induce important alterations in neuronal function that could play a role in neurodegeneration.

Inhibition of erythrocyte phosphoribosyltransferases (APRT and HPRT) by Pb2+: a potential mechanism of lead toxicity

Many reports show that red blood cells of people exposed to lead have a decreased ATP concentration, decreased adenylate energy charge value and many metabolic and morphological abnormalities. Since the synthesis of nucleotides in erythrocytes occurs only through salvage pathways, we hypothesized that a decrease in nucleotide concentrations may be caused by lead-induced inhibition of erythrocyte phosphoribosyltransferases: adenine APRT (EC 2.4.2.7) and hypoxanthine-guanine HPRT (EC 2.4.2.8). These enzymes enable the reutilization of purine bases (adenine, guanine, hypoxanthine) converting them to mononucleotides (AMP, GMP, IMP), substrates for the synthesis of high-energy nucleotides. To confirm the hypothesis two experiments were performed: (i) in vitro, using a lysate of human erythrocytes incubated (5, 10, 30min) with lead ions (100microM, 10microM, 1microM, 500nM, 100nM lead acetate) and 100microM sodium acetate for the control, (ii) in vivo, using a lysate of rat erythrocytes taken from rats chronically exposed to lead (0.1% lead acetate in drinking water for 9 months, resulting in whole blood lead concentration 7microg/dL). The activities of APRT and HPRT were determined using HPLC method, which allowed concurrent determination of the activity of both enzymes in erythrocyte lysates. We have shown that, lead ions: (i) moderately inhibit both phosphoribosyltransferases in erythrocytes, this influence being detectable even at very low concentrations (ii) participate in hemolysis, the intensity of which negatively correlates with the activity of phosphoribosyltransferases. Our results indicate the necessity of further research on the role of lead-induced APRT and HPRT inhibition as one of the mechanisms of lead toxicity.

The effect of stem cell mobilisation with granulocyte colony-stimulating factor on the morphology of the haematopoietic organs in mice

The cellular mobilisation of mice with granulocyte colony-stimulating factor (G-CSF) results in an egress of haematopoietic stem/progenitor cells from the bone marrow and an increase in their level in the peripheral blood. While the mobilisation process with different agents is widely studied, little is known about the morphology of the murine haematopoietic organs during the mobilisation. The purpose of this study was to examine the morphology of the bone marrow, spleen and liver in mice mobilised with G-CSF. To address this issue mice were injected subcutaneously with G-CSF for 6 consecutive days. Morphological analysis revealed an increase in the number of mature neutrophils close to the wall of sinusoids in the bone marrow as well as hypertrophy of the red pulp in the spleen. At the same time no morphological changes were noticed in the livers of G-CSF-mobilised mice. In conclusion, G-CSF induces discrete ultrastructural changes in the bone marrow, which intensify the transendothelial traverse of haematopoietic stem and progenitor cells from it. The changes in the spleen are related to repopulation of this organ by mobilised early haematopoietic cells circulating in the peripheral blood. We also noticed that the process of migration of haematopoietic cells from the bone marrow into the peripheral blood began on day 2 and was most pronounced on day 4 after stimulation with G-CSF.

Effect of stem cell mobilization with cyclophosphamide plus granulocyte colony-stimulating factor on morphology of haematopoietic organs in mice

Both granulocyte colony-stimulating factor (G-CSF) and cyclophosphamide (CY) are employed in the clinic as mobilizing agents to stimulate the egress of haematopoietic stem/progenitor cells (HSPC) from bone marrow (BM) into peripheral blood (PB). However, although both compounds are effective, the simultaneous administration of G-CSF + CY allows for optimal mobilization. The aim of this study was to compare morphological changes in major haematopoietic organs in mice mobilized by G-CSF + CY. We employed the standard G-CSF + CY mobilization protocol, in which mice were injected at day 0 with a single dose of CY followed by daily injection of G-CSF for 6 consecutive days. We noticed that the cytoreductive effect of CY on BM and spleen tissue was compensated at day 2 by the pro-proliferative effect of G-CSF. Furthermore, as evidenced by histological examination of BM sections at day 4, egress of haematopoietic cells from BM was accelerated by 2 days as compared to mobilization by G-CSF or CY alone; also, by day 6 there was accumulation of early haematopoietic (Thy-l(low) c-kit+) cells in the spleens and livers of mobilized animals. This implies that HSPC that are mobilized from BM and circulate in PB may 'home' to peripheral organs. We envision that such an accumulation of these cells in the spleen (which is a major haematopoietic organ in mouse) allows them to participate in haematopoietic reconstitution. Their homing to other sites (for example the liver) is evidence that BM-derived stem cells are playing a pivotal role in organ/tissue regeneration. The potential involvement of major chemoattractants for stem cells, like stromal-derived factor-1 which is induced by CY in various regenerating organs such as the liver, requires further study. We conclude that inclusion of CY into mobilization protocols on the one hand efficiently increases the egress of HSPC from the BM, but on the other hand may lead to the relocation of BM stem cell pools to peripheral tissues.

Morphology of the testis and the epididymis in rats with dihydrotestosterone (DHT) deficiency

The aim of the study was to estimate morphology in the testis and epididymis of adult rats, treated with finasteride for 28 days (the time period of two seminiferous epithelium cycles) and 56 days (the time period of one spermatogenesis). A 28 days long DHT deficiency did not significantly influence the structure of seminiferous epithelium. After 56 days of treatment, finasteride induced sloughing of immature genninal cells (spermatids and rarely pachytene spermatocytes) into the lumen of the seminiferous tubules. A reduced content of spermatozoa was observed in the lumen of rat epididymis in rats with 56-day-long deficiency. The results indicated that 5alpha-reductase 2 activity is important for the maintenance of spermatogenesis. The decreased content of spermatozoa in the epididymal lumen of rats, treated with finasteride during one course of spermatogenesis, could reflect seminiferous epithelium condition.

Primary culture of the rat epididymal epithelial cells as a source of oestrogen

Studies were performed on the rat epithelial cells of the caput and cauda epididymidis cultured in a full medium enriched with foetal calf serum without or with exogenous testosterone. After 3 days of culture, the cells formed a monolayer. The cytoplasm of epididymal epithelial cells cultured with testosterone was rich in lipid droplets, glycogen and PAS-positive substances, while their content was decreased in the cytoplasm of cells cultured without testosterone. The activity of 3beta-hydroxysteroid dehydrogenase was observed both in the cytoplasm of cultured epididymal epithelial cells and epithelial cells of epididymal sections. Hormone assays showed very low levels of dehydroepiandrosterone, androstenedione and testosterone, and the absence of progesterone in the media of cells cultured without testosterone and higher testosterone concentrations when the cells were cultured with exogenous testosterone. However, the concentration of 17beta-oestradiol found in the medium of cells was high, and exceeded many-fold its levels in the control media. Lentaron (Formestan), steroidal inhibitor of cytochrome P450 aromatase added to the culture decreased the secretion of oestradiol. RT-PCR analysis yielded cDNA products of 333 bp in length when primers were chosen to amplify a highly conserved sequence in the 3' region of the cytochrome P450 aromatase gene. This study demonstrates the ability of epididymal epithelial cells in vitro to synthesize androgens and mRNA for cytochrome P450 aromatase in the cultured epididymal epithelial cells of the rat as well as the ability to aromatise the synthesized androgen to 17beta-oestradiol.

Steroidogenic characteristics of in vitro cultured epididymal epithelial cells of the rat

The paper presents the steroidogenic features of cultured epithelial cells of rat epididymis and their ability to synthesize steroid hormones. The cytoplasm of epididymal epithelial cells accumulated lipid droplets and contained active enzymes of steroidogenesis. Numerous mitochondria with lamellar cristae occurred near lipid droplets. Frequently, mitochondria formed a direct contact with lipid droplets and smooth endoplasmic reticulum. The hormone assay showed that the epididymal epithelial cells cultured without dihydrotestosterone synthesized and released the following steroids: dehydroepiandrosterone (DHEA), testosterone (T) and 17beta-estradiol (E). The levels of DHEA and T were very low. The concentration of E detected in media of cultured epididymal epithelial cells exceeded many times the concentration of E in control media. The cytoplasmic presence of organelles and enzymes that participated in the steroid synthesis indicated their similarity to steroidogenic cells. Epididymal epithelial cells were capable of moderate in vitro synthesis of androgens. It cannot be excluded that steroidogenesis in the cultured epididymal epithelial cells is maintained to sustain 17beta-estradiol synthesis pathways.

[Steroidogenesis in epithelial cells of rat epididymis]

Studies were performed on cultured epithelial cells of the caput and cauda of epididymis stemming from male rats of inbred Wistar strain. The cultures were conducted on a full medium enriched with 5% fetal calf serum in the presence or without exogenic androgens-T and DHT. The cells were identified by means of immunohistochemical reactions with the use of monoclonal antibodies against cytokeratin and desmin (Fig. 1, 2). All cells in the culture showed positive reaction to cytokeratin. At the same time there was a lack of desmin-positive cells. Through secreting the proteins, glycoproteins, glycolipids, phospholipids and number of other substances the epithelial cells of epididymis create an environment for maturating and storing of spermatozoa in lumen of the duct. Synthesis of these substances is possible thanks to the expression of genes defined for a given zone of epididymis, the expression being mainly regulated by androgen, although a share of estrogens is also evidenced in this process. The cytoplasm of epithelial cells of epididymis fails to reveal the presence of secretory granules, while the mechanism of releasing the secretion still continues to be controversial. There are also some and unverified suggestions about the capability of these cells to synthesize androgens. In connection with what was mentioned above, the objective of the work was to establish the mode of releasing the secretions by cultured epithelial cells of epididymis as well as to determine whether these cells synthesize androgens and if they may be the source of estrogens. Electron-microscopic observations disclosed a rich content of rough endoplasmic reticulum and structures similar to secretory units produced from concentrically arranged membranes encircling cytoplasm fragments in their interior (Fig. 10B, 14, 15A). There were protrusions of cytoplasm on the surface of cells. Released secretion was present between the cells. The apocrine way of releasing was confirmed also by scanning electron microscope. Numerous granular protrusions were released into the intercellular space (Fig. 19). The process of synthesis and release of secretion was androgen-dependent. Cells cultured without addition of exogenic androgens were characterized by disorganization of organelles and reduction of their number, particularly rough endoplasmic reticulum. The surface of cells was prevalently smooth, deprived from protrusions (Fig. 21). Very close neighbourhood, and sometimes a direct contact of lipid droplets and mitochondria with lamellar cristae as well as the presence of smooth endoplasmic reticulum observed in cytoplasm of cultured epithelial cells of epididymis, suggest their similarity to steroidogenic cells (Fig. 11A, 12). This is also indicated by the finding that these cells reveal the presence of active enzymes of the steroidogenesis pathway, 3 beta-HSD and 17 beta-HSD exhibited in histochemical reactions (Fig. 8, 9). RIA determination of hormones in the medium, wherein the epithelial cells had been cultured showed that the said cells synthesized and released DHEA, A and T, but in low and sometimes trace concentrations (Tab. 1-3). Lack of progesterone in medium of the cells on the 3rd and 5th days of culture indicates that the synthesis of testosterone and earlier forms of androgens proceeds using delta 5 metabolites, as it takes place in human testis. The cells' medium on the 3rd and 5th days of culture was found to disclose high concentration of 17 beta-estradiol (E2) (Tab. 4). E2 concentrations were always higher when the cells were grown without the addition of exogenic androgens. In this cases the cytoplasm of the cells displayed depolymerization of microtubules, which enhances the approximation to each other of structures participating in steroidogenesis and translocation of substrates and products of the consecutive stages of steroidogenesis. (ABSTRACT TRUNCATED)

Phospholipid content and lamellar structures in the epididymal epithelial cells of rats treated chronically with lead acetate [Pb(II)]

The electron-microscopic observations accomplished covered epididymal epithelial cells of rats receiving lead acetate for five times longer than the duration of one spermatogenesis. These cells were found to possess a large number of vacuoles and conglomerates containing plicated membranes or tightly packed myelin-like lamellar formations. Further observations also revealed the formation of lamellar structures in mitochondria, dilatation of cisternae in the Golgi apparatus, and increased phagocytosis of spermatozoa by epithelial cells. The presence of a large amount of membranous material correlated with the increased content of phospholipids in epididymal epithelial cells. It may be suggested that the presence of such a great quantity of lamellar structures in epididymal epithelial cells of rats treated chronically with lead is the result of several processes, including the augmented synthesis of membranes associated with encircling the deposits of lead, autophagy in the cells, as well as intensified phagocytosis of spermatozoa.

In vivo and in vitro studies on the toxicity of Hoechst 33342 (Ho342). Implications for employing Ho342 for the isolation of haematopoietic stem cells

The fluorescence dye Hoechst 33342 (Ho342) is employed for isolating early haematopoietic cells and the aim of this study was to evaluate the in vivo and in vitro toxicity of this compound. First, by employing a murine model we studied the influence of this dye on the morphology of the different organs of animals that have been injected intravenously with increasing doses of Ho342. Accordingly, we found that Ho342 at relatively low doses (0,3 M) caused morphological changes in the spleen and lungs and at higher doses (1,5 & 6 M) damaged also the liver. In contrast, kidneys appear to be relatively resistant to this dye. Next, since Ho342 is employed for isolating early haematopoietic cells by FACS, we have been looking for potential toxicity of this dye against normal human haematopoietic progenitors. Accordingly, CD34+ cells isolated from cord blood (CB) samples were exposed to increasing doses of Ho342 (0-50 microM). We found that the low concentration of Ho342 (10 microM) recommended for isolating HSC significantly inhibited the clonogenecity of human erythroid progenitors (BFU-E). The higher doses of Ho342 have also been toxic against normal human myeloid progenitors (CFU-GM). This study shows that Ho342 could potentially damage human cells. This fact should be considered whenever Ho342 has to be employed for isolating living cells.

Inducible nitric oxide synthase in the epithelial epididymal cells of the rat

The expression of mRNA for inducible nitric oxide synthase (iNOS) in rat epithelial cells of epididymis was investigated with reverse transcription followed by polymerase chain reaction. Immunocytochemical reaction for iNOS was performed to confirm the enzyme's localization in the epididymal epithelium. Additionally, an indirect spectrophotometric method for nitric oxide (NO) determination was applied for measurement of nitrite production by cultured epididymal epithelial cells. Inducible NOS mRNA was detected in freshly isolated epithelial cells, in cultured cells without stimulation as well as in cultured cells after stimulation by lipopolysaccharide and interferon-gamma. Inducible NOS immunoreactivity was observed in the apical part of epithelial cells of epididymal sections and in the cytoplasm of cells in culture. Release of nitrite was observed in vitro in both the unstimulated and stimulated cells of caput (1.44+/-0.94 v. 4.37+/-2.42 microM) and cauda (0.69+/-1.21 v. 5.21+/-2.76 microM) epididymis (P < 0.001). To the best of our knowledge, this is the first study to demonstrate iNOS in the epididymal epithelial cells of the rat. Nitric oxide released by epididymal epithelial cells may act on cells and tissues located nearby. The results may help explain epididymal function: sperm storage, passage and maturation. Excessive epididymal NO production may also play a role in the inflammatory infertility of the male.