Effect of testicular degeneration on expression of sperm protein at 22 kDa in stallions

BACKGROUND

Sperm protein at 22 kDa has been associated with fertility.

OBJECTIVES

The objectives of this study were to determine (1) the localization pattern of SP22 on ejaculated and caudal epididymal equine spermatozoa and in epididymal fluid, and to (2) characterize SP22 protein and mRNA expression in testicular and epididymal tissues in response to heat-induced testicular degeneration.

MATERIALS AND METHODS

Semen was collected before and after hemi-castration, as well as prior to and following insulation of the remaining testes, and tissue specimens were collected for analysis.

RESULTS

Histopathology confirmed degeneration in insulated testes. Ejaculated and epididymal spermatozoa from samples collected prior to insulation of the testicles had a predominant staining pattern of SP22 over the equatorial region. However, the equatorial pattern in the pre-insulation epididymal semen samples was significantly lower than in the pre-insulation ejaculated semen samples (68 ± 3, 81 ± 2.6, respectively). Ejaculated and epididymal samples collected after insulation of the testicles showed a complete loss of staining as the predominant pattern. Western blot analysis verified the presence of SP22 on fresh ejaculated spermatozoa prior to and following heat-induced degeneration, on epididymal spermatozoa after testicular insulation, and in testicular and epididymal tissues. Heat insulation significantly reduced messenger RNA expression in the head of the epididymis and testicular tissues. Immunohistochemistry of the testicular and epididymal tissues pre-heating showed considerably weaker staining than the same tissues post-heating.

DISCUSSION AND CONCLUSION

It was concluded that heat-induced testicular damage causes both loss and relocation of SP22 on the sperm membrane. Future studies are warranted to determine the diagnostic value of these findings.

Evaluation of Spermatogenic Activity of Polyherbal Compound Musalyadi Churna and its Protective Effect Against Nicotine-Induced Testicular Degeneration in Sprague-Dawley Rats

Background

The ancient science of life known as Ayurveda uses a variety of formulations or herbal compounds to treat a wide range of illnesses. Male infertility accounts for half of all infertility worldwide, and numerous etiological variables play a role. A pharmacologically active tobacco component called nicotine has a negative impact on male fertility and the reproductive system. Musalyadi Churna (MSC) is one of the polyherbal compound formulations mentioned in Ayurveda Classics for aphrodisiac therapy and recommended for the treatment of male infertility.

Objective

The current study aims to evaluate the spermatogenic potential of MSC along with its protective effect against testicular degeneration induced by nicotine in rat models.

Materials and Methods

Sixty adult Sprague-Dawley male rats were used in the experiment, which were divided into ten groups of six rats each. Nicotine was administered orally as disease control. The standard and vehicle control were also included along with study drug groups in which MSC was administered orally to the rats. The study was conducted for 70 days for each group with assessment of body weight and food consumption. After treatment, rats were weighed and sacrificed for evaluation of parameters like organ weight, epididymal sperm count, and sperm morphology along with histological assessment. The data were statistically evaluated using analysis of variance test and Bonferroni multiple-comparison range test to compare different treatment groups.

Results and Conclusion

In the present study, MSC possesses substantial spermatogenic efficacy, and the result indicates that the study drug possesses a protective effect against nicotine-induced impaired testicular functions in rats, but further research to elucidate its exact mechanism of action is essential.

Characterisation of the testicular transcriptome in stallions with age-related testicular degeneration

BACKGROUND

Age-related testicular degeneration can be defined as the progressive deterioration of the testis that typically occurs in middle-aged or older males and that leads to diminished testicular function and subfertility. In the equine breeding industry, genetically valuable males maintain their value as breeding animals well into old age. Because testicular degeneration is common in middle-aged and older stallions, the disease often has a significant negative impact on a stallion's breeding career and leads to economic losses in the horse breeding industry.

OBJECTIVE

Because testicular degeneration is a tissue autologous disease in the horse, the objective of this study was to use whole-transcriptome sequencing to compare the testicular transcriptomes of normal, fertile stallions to those of stallions affected by age-related testicular degeneration in order to better understand the pathophysiology of the disease.

STUDY DESIGN

Cross sectional.

METHODS

Testicular tissue samples from clinical castrations or euthanasia were collected from normal healthy (n = 3) or older subfertile (n = 4) stallions. Samples were processed and sequenced on an Illumina HiSeq™ 2000 Sequencing System. Bioinformatic analysis of the data was performed in R/RStudio, and the transcriptomes were compared between the two groups. Genes were considered to be differentially expressed between healthy and diseased tissue if they demonstrated at least a ±1.5× fold change difference and had a false discovery rate-adjusted P value <0.05. Gene ontology analysis was performed using Ingenuity® IPA.

RESULTS

Analyses of differential expression of individual genes, as well as computer-based gene ontology analysis, identified upregulation of cytokine-mediated inflammatory pathways in testes from stallions affected with testicular degeneration. This upregulation of inflammation was associated with upregulation of cell survival pathways, inhibition of apoptotic pathways and increases in collagen formation.

MAIN LIMITATIONS

There are unavoidable confounding factors (e.g. differences in breed, management, environment, age) that could create non disease-related genetic variation between our normal and affected samples. In addition, there are practical limitations to applying computer-based gene ontology analysis to equine samples. Gene ontology software relies on published information (mostly non-equine), and some biological processes (e.g. apoptosis and inflammation) are more commonly studied than others and so are over-represented in the literature and therefore more likely to be identified by computer algorithms. Caution should be taken when interpreting the data, as alterations in gene expression can be the cause of disease processes or can be the result of disease processes.

CONCLUSIONS

These results suggest that chronic, low-grade inflammation may be involved in the pathophysiology of age-related testicular degeneration in stallions.

A novel testicular degenerative condition in a wild population of the common carp Cyprinus carpio (L)

Gonad abnormalities can restrict or completely block reproductive capability of individuals and in some case that of their populations. Here, we describe a novel testicular degenerative condition of non-germ cell origin with a high prevalence (up to 22.1% of the population) in a wild population of carp. Based on gross morphology, and microscopic and cellular examinations, the condition shows progressive severity which could be categorized into low, mild, severe and complete. In early stages of the condition, an abnormally increased proliferation (11-fold) of the Sertoli cell occurred, followed by degenerative cell death of all testicular cells, resulting in fluid-filled vesicles in the later stages. This initial uncontrolled proliferation of Sertoli cells suggests that the condition could be triggered by malignant pathways; however, the observed subsequent apoptosis of all testicular cells en masse, rendering the animals "sterile," appears unique. Observations, to date, indicate that this condition is specific to male carp and not present in other species of fish sharing the habitat. High prevalence of the condition allowed comparative evaluation between affected individuals, an aspect likely to facilitate future studies, including elucidation of the cause, robust testing of therapies and practical applications such as management of feral carp populations.

Changes of reproductive indices of the testis due to Trypanosoma evansi infection in dromedary bulls (Camelus dromedarius): Semen picture, hormonal profile, histopathology, oxidative parameters, and hematobiochemical profile

Objective:

IThis study was designed for the investigation of the effect of infection by Trypanosoma evansi on the changes of reproductive indices of the testis, causing reproductive failure in dromedary bulls (Camelus dromedarius).

Materials and methods:

Seventy-five bulls were used for monitoring of the changes in the semen characteristics, reproductive hormones, hematobiochemical profiles, histopathological characters in the testis, and oxidative biomarkers. The animals were divided into two groups. Group A represented the uninfected or control group, while group B represented the infected group. Group B was again divided into two subgroups, such as acute and chronic infected animals.

Results:

Results showed that the semen analysis of infected camels revealed the presence of alterations in the morphology of sperms, especially the heads and tails, as compared to control animals. The hormonal profile indicated a significant decrease in the luteinizing hormone, follicle- stimulating hormone, and testosterone levels, accompanied by the rise in the cortisol level in infected camels compared with the negative control. The histopathology and testicular degeneration were found to be associated with other disorders in infected camels. The oxidative profile and protein oxidation were promoted in infected testicles, indicating the occurrence of harmful effects in the cell.

Conclusion:

It is concluded that T. evansi infection in dromedary bulls causes severe damage to the testicular tissue and decreases the reproductive hormone levels associated with severe morphological disorders in sperms due to oxidative stress resulting from the infection. All these findings indicate that T. evansi can cause reproductive failure and fertility damage.

Severe Degenerative Changes in Cryptorchid Testes in Japanese Black Cattle

This is a histopathologic and endocrinologic study of 6 calves diagnosed with cryptorchidism. Cases 1-3 were diagnosed as resembling testicular regression syndrome. In cases 1 and 2, the extracted tissue was a small, firm, gray-white mass, and there was lack of obvious testicular tissue in case 3. Histopathologically, the excised tissue in cases 1-3 was a fibrotic testicular remnant with inflammation, mineralization, hemosiderin-laden macrophages or lipofuscin-laden macrophages, and lack of germ cells and interstitial endocrine cells. These findings were compared with cases 4-6, which were diagnosed as testicular hypoplasia due to cryptorchidism. These cases had small but otherwise grossly unremarkable intra-abdominal testicular tissue and histologically had a few germ cells and sustentacular cells with arrested spermatogenesis and an increase in interstitial endocrine cells. Cases 1-3 had more severe degenerative changes compared with cases 4-6. In case 2, the average diameter of the seminiferous tubules was much smaller than in cases 4-6, and there were few tubule cross sections. Anti-Müllerian hormone (214 pg/ml) was detected in the plasma of case 2. Based on the macroscopic and histopathologic findings as well as endocrinologic profiles, the testicular degeneration in cases 1-3 was considered similar to that of testicular regression syndrome. In this condition, it is thought that a normally developing intra-abdominal testis undergoes degeneration due to heat or a vascular disorder such as torsion.

Effects of intratesticular injection of zinc-based solution in rats in combination with anti-inflammatory and analgesic drugs during chemical sterilization

Aim

Chemical sterilization is a non-surgical method of contraception based on compounds injected into the testis to induce infertility. However, these injections can cause discomfort and pain able to impair the recovery of animals after this treatment. The objective of this study was to investigate if anti-inflammatories or pain relievers inhibited the sterilizing effect of zinc gluconate-based solution on the testis.

Materials and Methods

Adult rats were treated in groups: G1 (control), G2 (dimethyl sulfoxide + dipyrone); G3 (dipyrone/zinc); G4 (dipyrone + celecoxib/zinc); G5 (dipyrone + meloxicam/zinc), and G6 (dipyrone + dexamethasone/zinc) in a single dose per day during 7 days. Animals were analyzed at 7, 15, and 30 days after treatments.

Results

The zinc-induced a widespread testicular degeneration and decreased testosterone levels even in combination with anti-inflammatories or pain relievers. Testis, epididymis, prostate, and seminal vesicle had a weight reduction. The anti-inflammatory effect of dexamethasone interfered in the desired action of zinc gluconate in the 1^st 15 days and celecoxib up to 7 days.

Conclusion

Meloxicam plus dipyrone did not impair the chemical sterilization based on zinc gluconate, and it can be used to reduce nociceptive effects in animals after chemical sterilization.

Testicular pathology, gonadal and epididymal sperm reserves of Yankasa rams infected with experimental Trypanosoma brucei brucei and Trypanosoma evansi

AIM

The study was conducted to evaluate the pathological effects of trypanosomosis on the testes, gonadal, and epididymal sperm reserves of Yankasa rams for 98 days.

MATERIALS AND METHODS

A total of 16 Yankasa rams, aged between 24 and 30 months and weighed between 22 and 25 kg, were acclimatized for a period of 2-months in a clean fly proof house and were adequately fed and given water ad-libitum. Of the 16 rams, 12 that were clinically fit for the experiment at the end of the acclimatization period were randomly divided into four groups: Groups I, II, III, and IV, each having 3 rams. Groups I and II were each challenged singly with experimental Trypanosoma brucei brucei (Federer strain) and Trypanosoma evansi (Sokoto strain), respectively, while Group III was challenged with mixed T. brucei brucei and T. evansi parasites (50% of each species in the infective inoculum) and Group IV was left as an uninfected control. Each infected ram received 2 mL of the infected blood containing 2×10(6) trypomastigotes via the jugular vein, while the control group received 2 mL each, normal saline.

RESULTS

All the infected rams developed clinical signs typical of trypanosomosis at varying pre-patent periods. The gross lesions observed in the infected rams in Group II were moderate and more severe in those of Groups I and III. Histological sections of the testes of infected rams (Groups I, II, and III) showed moderate (T. evansi-infected group) to severe (mixed and T. brucei brucei-infected groups) testicular degenerations with reduction in number of spermatogenic cell layers, degenerated seminiferous tubules, congested interlobular spaces, loss of tissue architecture with significant (p<0.01) depletion, and loss of gonadal and epididymal sperm reserves in Groups I and III in comparison to Group II and the control Group IV. No observable clinical signs and histopathological lesions were found in those rams of the control Group IV.

CONCLUSION

The study concluded that trypanosomosis due to experimental T. brucei brucei or T. evansi or mixed infections (of both parasites) caused testicular damage, decreased epididymal and gonadal sperm reserves and an important cause of infertility in Yankasa rams.

mTOR Regulates Gap Junction Alpha-1 Protein Trafficking in Sertoli Cells and Is Required for the Maintenance of Spermatogenesis in Mice

The mammalian target of rapamycin (Mtor) gene encodes a serine/threonine kinase that acts as a master regulator of processes as diverse as cell growth, protein synthesis, cytoskeleton reorganization, and cell survival. In the testis, physiological roles for Mtor have been proposed in perinatal Sertoli cell proliferation and blood-testis barrier (BTB) remodeling during spermatogenesis, but no in vivo studies of Mtor function have been reported. Here, we used a conditional knockout approach to target Mtor in Sertoli cells. The resulting Mtor(flox/flox); Amhr2(cre/+) mice were characterized by progressive, adult-onset testicular atrophy associated with disorganization of the seminiferous epithelium, loss of Sertoli cell polarity, increased germ cell apoptosis, premature release of germ cells, decreased epididymal sperm counts, increased sperm abnormalities, and infertility. Histopathologic analysis and quantification of the expression of stage-specific markers showed a specific loss of pachytene spermatocytes and spermatids. Although the BTB and the ectoplasmic specializations did not appear to be altered in Mtor(flox/flox);Amhr2(cre/+) mice, a dramatic redistribution of gap junction alpha-1 (GJA1) was detected in their Sertoli cells. Phosphorylation of GJA1 at Ser373, which is associated with its internalization, was increased in the testes of Mtor(flox/flox); Amhr2(cre/+) mice, as was the expression and phosphorylation of AKT, which phosphorylates GJA1 at this site. Together, these results indicate that Mtor expression in Sertoli cells is required for the maintenance of spermatogenesis and the progression of germ cell development through the pachytene spermatocyte stage. One mechanism of mTOR action may be to regulate gap junction dynamics by inhibiting AKT, thereby decreasing GJA1 phosphorylation and internalization. mTOR regulates gap junction alpha-1 protein distribution in Sertoli cells and is necessary for progression through the pachytene spermatocyte stage.