Characterization of sperm motility and testosterone secretion in the taiep myelin mutant, a model of demyelination

Presently, demyelinating diseases have been reported to affect the reproductive life of patients who suffer from them, but the progression of the alterations is unknown, especially in men. To better understand these effects, it is necessary to perform studies in animal models, such as the male taiep rat, which exhibits progressive demyelination of the central nervous system, altered kisspeptin expression at the hypothalamic level, and decreased luteinizing hormone, which could alter sperm quality and testicular diameter. Thus, the objective of the present study was to analyze the diameter of the seminiferous tubules, the sperm motility, and the testosterone levels of 90-day-old male taiep rats. The obtained results indicate that male taiep rats show an increase in testicular size accompanied by an increase in the diameter of the seminiferous tubules of the left testicle. There was also a decrease in progressive motility in sperm samples from the left epididymis of male taiep rats compared to the control group, with no changes in serum testosterone concentration. Therefore, we conclude that male taiep rats with central demyelination show altered testicular diameter and decreased motility in sperm from the left side. This type of studies serves as a basis for proposing possible reproductive strategies to improve the fertility and testicular function of men with demyelinating diseases of the central nervous system.

Acute effects of para-chloroamphetamine on testosterone and markers of apoptosis in seminiferous epithelium of prepubertal male rats

Serotonin is a neurotransmitter that affects the secretion of gonadotropins and testosterone. In prepubertal male rats, serotonin has a stimulating role in testosterone secretion. Here, we used prepubertal male rats to study the effects of para-chloroamphetamine (pCA) on circulating testosterone and gonadotropins and markers of apoptosis in germ cells from day 1 to day 5 post-treatment. The intraperitoneal administration of pCA induced a significant reduction in concentrations of hypothalamic serotonin and circulating testosterone, but gonadotropins were not affected. In the seminiferous epithelium of pCA-treated rats, increased the number of germ cells positive to markers of apoptosis, concomitantly with alterations in morphometry and the presence of multinucleated germ cells. Levels of testosterone were reduced starting from 1 day after pCA was administered. The time window between the administration of the pCA and collection of samples was sufficient to detect changes in testosterone levels, in contrast with a previous work where no changes were found. There was a possible relationship between the reduction of testosterone and an increase in the number of germ cells positive to apoptosis markers. However, the mechanism that links pCA-testosterone-germ cell positive to markers of apoptosis is unknown. Our outcomes support the view that pCA exposure during the prepubertal stage has an acute impact on testosterone levels and affects the structure and physiology of seminiferous epithelium.

Expression of the NSE,SP,NFH and DβH in normal and cryptorchid testes of Bactrian camel

Neuroendocrine substances play essential roles in regulating the normal physiological functions of testicles. The purpose of this study is to explore the localization and effects of four neuroendocrine markers (NSE, SP, NFH and DβH) in normal and cryptorchid testes of Bactrian camels using western blotting, transmission electron microscopy, immunohistochemistry, and immunofluorescence methods. The results showed that cryptorchidism caused a reduction in layers of spermatogenic epithelium and decreased glycogen positivity in the basement membrane. The ultrastructure revealed that macrophages were always found around the Leydig cells, crowded with swelling mitochondria in cryptorchidism. Expression of NSE in the Leydig cells of cryptorchidism was significantly weakened compared to that in the normal group(p<0.01). We found that SP was always distributed along the nerve fibers in normal testes and was expressed in the Leydig cells of cryptorchidism. However, expression of NFH in the cryptorchidic tissue was strongly positive in the spermatogenic epithelium, with limited expression in Leydig cells and no expression in peritubular myoid cells. Therefore, the expression of DβH in the Sertoli cells was comparatively strong in both the normal and cryptorchidism groups. NFH and DβH expression was significantly increased in the cryptorchidism group compared with the normal group (p<0.01). These findings indicated that the underdeveloped seminiferous epithelium and pathological changes in cryptorchid tissue in Bactrian camels were potentially related to a disorder in glycoprotein metabolism. Our results suggest that NSE and SP could help judge the pathological changes of cryptorchidism. The present study provides the first evidence at the protein level for the existence of NFH and DβH in Sertoli and Leydig cells in Bactrian camel cryptorchidism and provides a more in-depth understanding of neuroendocrine regulation is crucial for animal cryptorchidism.

Quantification of neural and hormonal receptors at the prostate of long-term sexual behaving male rats after lesion of pelvic and hypogastric nerves

Prostate function is regulated by androgens and a neural control via the pelvic and hypogastric nerves. As such, this sexual gland contains receptors for acetylcholine and noradrenaline, although it is unknown whether the expression of these receptors is affected by sexual behavior and even less by denervation of the gland. Thus, the purpose of this work was to evaluate the effect of repeated sexual behavior on the expression of noradrenaline, acetylcholine, and androgen receptors at the prostate, and how they are affected by denervation. To achieve this, we used sexually experienced males denervated at the pelvic or hypogastric nerves, or both. The messenger (mRNA) and protein for androgen, noradrenergic, and cholinergic receptors were evaluated. The weight of the gland and the levels of serum testosterone were also measured. We found that: (1) sexual behavior was not affected by denervation; (2) blood testosterone levels increased due to sexual behavior but such increase is prevented by denervation; (3) the weight of the ventral prostate increased with sexual behavior but was not affected by denervation; (4) AR messenger levels increased with sexual behavior but were not altered by denervation; (5) the messenger for noradrenergic and cholinergic receptors decreased after denervation, and those for muscarinic receptors increased, and (6) only AR protein decreased after denervation of both nerves, while those for other receptors remained unchanged. In summary, we show that the three receptors have different regulatory mechanisms, and that only androgen receptors are regulated by both autonomic systems.

Severing the ventral funiculus in chronic spinal cord injury has the most deteriorating effect on spermatogenesis in rats

Sexual dysfunction, following spinal cord injury (SCI), is highly dependent on the extent of injury. SCI disrupts the supraspinal innervation of the reproductive organs; resulting in structural and functional deficits. Relating the extent of SCI to these changes could eventually improve diagnoses and treatment planning of sexual dysfunction following SCI. In the present study, following chronic SCI of different severities (1/3 dorsal SCI (1/3 SCI), 2/3 dorsal SCI (2/3 SCI), and complete transection (Tx)) at T8 spinal level, histological changes of seminiferous tubules parameters in testis were examined. The diameter of seminiferous tubules (DST) and epithelial height of seminiferous tubules (HST) were significantly decreased in all SCI groups compared to control and sham. In addition, DST in 2/3 SCI and Tx groups and HST in Tx group were significantly decreased in comparison with 1/3 SCI animals. Nonetheless, the diameter of seminiferous tubules' lumen decreased significantly in 2/3 SCI and Tx compared to control, sham, and 1/3 SCI groups. Concerning cellular component, the number of spermatocytes and spermatids layers significantly decreased in both 1/3 and 2/3 SCI in comparison to normal. However, Tx had the most prominent deteriorating effect on these layers; indicating impairment in the process of spermatogenesis. These results show that the spinal tracts are part of the neural circuitries innervating the testis and responsible for their structural support. These tracts are mainly distributed between the lateral and ventral funiculi at T8 spinal level. Consequently, sparing ventral funiculi in the SCI prevents the severe decline in spermatogenesis.

Histochemical Study of the Emergence of Apoptosis and Altered SYCP3 Protein Distribution During the First Spermatogenic Wave in Wistar Rats

Apoptosis is a type of cell death responsible for maintaining tissue homeostasis that can occur in male gonads. The morphological and biochemical characteristics of apoptosis include cellular contraction, caspase activation, and DNA fragmentation. Dynamic processes of cell renewal and differentiation occur inside the seminiferous tubules, which are regulated by mitosis and meiosis, respectively. During meiosis, recombination is caused by assembly of the synaptonemal complex, which involves the participation of constitutive proteins, such as synaptonemal complex protein-3 (SYCP3). The present study evaluated germinal cell death in immature male rats and the distribution of the SYCP3 protein. Our results indicate that as germinal cells progress to the second meiotic stage, significant numbers of them are eliminated by apoptosis. We determined that the SYCP3 protein is not always incorporated into the structure of the synaptonemal complex but rather forms a nuclear cumulus near the inner nuclear membrane, causing many of these cells to undergo apoptosis. We propose that both the excess of the SYCP3 protein and its accumulation during the first meiotic division could contribute to the cell death of primary spermatocytes during the first spermatogenic wave in prepubertal Wistar rats. Anat Rec, 302:2082-2092, 2019. © 2019 American Association for Anatomy.

Chronic Intake of Green Propolis Negatively Affecting the Rat Testis

BACKGROUND

Human and animal evidence suggests that environmental toxicants may have an adverse impact on male reproductive health, reducing the population's reproductive output. Owing to the renewed attraction for natural products, some of them constitute effective alternatives to mitigate these effects. Propolis is a candidate for this use because of its intrinsic properties. In many situations, it improved the testicular damage and alleviated the toxic effects induced by environmental contaminant exposure.

OBJECTIVE

The aim of this study was to investigate possible alterations of testicular parameters and certify if its use is really advantageous to the testis, since this could affect rat reproductive function.

MATERIALS AND METHODS

Forty-eight adult male Wistar rats were divided into four groups (Co = control, T1 = 3 mg propolis/kg/day, T2 = 6 mg/kg/day, T3 = 10 mg/kg/day) and were exposed during 56 days. The testes were assessed with morphometrical, stereological, and ultrastructural analyses. Cell proliferation and death were diagnosed, respectively, by immunocytochemistry. Connexin 43 (Cx43) and N-cadherin transcript levels were determined by reverse transcription-polymerase chain reaction.

RESULTS

Increased cell proliferation and Leydig cell volume were observed in T2, and in contrast, Cx43 upregulation and cell death were observed in T3. Both T2 and T3 showed ultrastructural abnormalities in testicular parenchyma.

CONCLUSION

We recommend a cautious intake of propolis to avoid deleterious effects.

SUMMARY

Chronic intake of Brazilian green propolis induced N.-cadherin downregulation and decreased on seminiferous tubule volumeIncrease on connexin 43 expression and cell death and decrease in Leydig cell.(LC) number/testis with the concentration of 10 mg/kg/day were observedIncrease on cell proliferation, cytoplasmic proportion, and volume of LC with the concentration of 6 mg/kg/day was detectedThe presence of empty spaces between spermatids and malformed spermatozoa in the lumen of seminiferous tubule was showedThis male reproductive disruption can be linked to phenolic compounds present in Brazilian green propolis. Abbreviation Used: AEC: 3-amino-9-ethylcarbazole; AJ: Adherens junction; AME: Aromadendrin-40-methyl ether; CAPE: Caffeic acid phenethyl ester; Co: Control group; C×43: Connexin 43; DAB: Diaminobenzidine; dNTP: Deoxyribonucleotide phosphate; DSP: Daily sperm production; FA: Ferulic acid; FSH: Follicle-stimulating hormone; GJ: Gap junction; GJIC: Gap junction intercellular communication; HPLC: High-performance liquid chromatography; LC: Leydig cell; LH: Luteinizing hormone; N-cad: N-cadherin; PCNA: Proliferating cell nuclear antigen; PCR: Polymerase chain reaction; RT-PCR: Reverse transcription-polymerase chain reaction; SDM: Standard deviation of mean; T1: Group exposed to 3 mg of propolis/kg/day; T2: Group exposed to 6 mg of propolis/kg/day; T3: Group exposed to 10 mg of propolis/kg/day; TUNEL: Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling; WB-ras 2 cells: Ras-transformed rat liver epithelial cell line.

Morphological and molecular characterisation of Twitcher mouse spermatogenesis: an update

Spermatogenesis is a complex developmental program in which interactions between different cell types are finely regulated. Mouse models in which any of the sperm maturation steps are perturbed provide major insights into the molecular control of spermatogenesis. The Twitcher mouse is a model of Krabbe disease, characterised by the deficiency of galactosylceramidase, the enzyme that hydrolyses galactosylceramide and galactosylsphingosine. Galactosyl-alkyl-acyl-glycerol, a precursor of seminolipid, the most abundant glycolipid in spermatozoa, is also a substrate for galactosylceramidase. Altered sphingolipid metabolism has been suggested to be the cause of the morphological abnormalities reported previously in the spermatogenesis of Twitcher. However, given the frequency of infertility associated with neurological impairment, we hypothesised that an unbalanced hormonal profile could contribute to male infertility in this mutant. In order to clarify this issue, we investigated potential variations in the expression of hormones and hormone receptors involved in the regulation of spermatogenesis. Our data show that, in the brain of Twitcher mouse, gonadotrophin-releasing hormone (GnRH), LH and FSH gene expression is decreased, whereas expression of androgen receptor (AR) and inhibin ?A (INH?A) is increased. The changes in gene expression for the LH and FSH receptors and AR in the testes support the hypothesis that altered sphingolipid metabolism is not the only cause of Twitcher infertility.

Follicular fluid Aβ40 concentrations may be associated with ongoing pregnancy following in vitro fertilization

PURPOSE

To determine whether Aβ40 levels in the follicular fluid (FF) of infertile women undergoing IVF demonstrate a relationship with IVF cycle parameters and outcome.

METHODS

FF Aβ40 levels were compared between patients achieving ongoing pregnancy and those with unsuccessful cycles. Clinical data such as ongoing pregnancy rate, implantation rate, number of oocytes retrieved, number of 8 cells embryos with ≤5 % fragmants, ratio of 8 cells embryos with ≤5 % fragmants to total embryos per patient and cleavage rate were compared among three percentile groups of Aβ40. CCK-8 method was used to measure the effect of Aβ40 on rat granulosa cells proliferation in vitro. RT-PCR was used to detect the mRNA expression levels of steroidogenesis related genes.

RESULTS

Patients achieving ongoing pregnancy (n = 26; 50.98%) demonstrated significantly higher FF Aβ40 levels compared to those with unsuccessful cycles (n = 25; 49.02%; P = 0.024). No significant differences were observed in APP (amyloid precursor protein) and its other proteolysis products including sAPPα, sAPPβand Aβ 42 between the two groups. Statistically significant differences between the three percentile groups of Aβ 40 were observed only in the implantation rates and ongoing pregnancy rates. There were no statistically significant differences between the three percentile groups in the age, No. oocytes retrieved, No. 2 pronucleus, No. embryos transferred, No. 8 cells embryos with ≤5% fragmants and cleavage rate. Significantly negative correlation exists between APP and AFC (antral follicle count) (R =-0.360, P = 0.005) and oocytes retrieved (R =-0.378, P = 0.004). There were also significantly positive correlations between Aβ40 and Aβ42 (R = 0.407, P = 0.000), between AFC and oocytes retrieved (R = 0.476, P = 0.000). Rat granulosa cells treated with Aβ40 of different concentrations have improved their proliferative ability. Cells treated with 200 pg/ml Aβ40 have the strongest ability of proliferation. 200 pg/ml Aβ40 enhanced the expression of key molecules during steroidogenesis such as IGF-1,IGF-1receptor (IGF-1R),FSH receptor (FSHR),P450 aromatase (P450arom),steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage cytochromes P450(P450scc).

CONCLUSIONS

Aβ40 levels in follicle fluid may be associated with ongoing pregnancy and the moderate expression level of Aβ40 is important for oocytes and embryos development.