Effects of epidermal growth factor on sperm content and motility of rats with surgically induced varicoceles

Sperm traits and seminal plasma proteome of locally adapted hairy rams subjected to intermittent scrotal insulation

The present study evaluated the effects of heat stress on reproductive parameters of hairy rams. Six animals were subjected to scrotal insulation during four consecutive nights (6 PM - 6 AM). Day (D) 0 was the first day of insulation. Scrotal circumference increased from 30.5 ± 0.3 cm (at pre-insulation) to 31.8 ± 0.4 cm on D4, decreased 3.9 cm on D28, returning to 30.6 ± 0.6 cm on D57. Sperm concentration decreased from 3.7 ± 0.12 ×109 sperm/mL before insulation to 2.6 ± 0.1 ×109 on D23, returning to normal on D57. Sperm motility averaged 75 ± 2.9% before insulation, was undetectable on D23, and became normal on D77. Sperm with normal morphology reached 5.9 ± 2.6% on D35 but recovered (86.8 ± 2.1%) on D91. Sperm DNA integrity decreased from 86.5 ± 4.7% before insulation to 11.1 ± 3.7% on D63, returning to pre-insulation values on D120. Sperm BSP immunostaining was reduced after scrotal insulation. Variations in seminal protein abundances coincided with changes in sperm parameters. Seminal plasma superoxide dismutase, carboxypeptidase Q-precursor and NPC intracellular cholesterol transporter 2 decreased on D18, returning to normal after D28. Albumin, inhibitor of carbonic anhydrase precursor, EGF-like repeat and discoid I-like domain-containing protein 3 and polymeric immunoglobulin receptor increased after insulation. In summary, intermittent scrotal insulation drastically altered ram sperm attributes and seminal proteins, especially those associated with oxidative stress. Knowledge of animal´s response to thermal stress is vital in the scenario of climate changes.

Gum Acacia attenuates cisplatin toxic effect spermatogenesis dysfunction and infertility in rats

This study aimed to investigate the potential benefits Gum Arabic/Acacia Senegal (GA) in mitigating the harmful effects of cisplatin (CP) on spermatogenesis and testicular health in male adult rats. A total of forty albino rats were used in the study and divided into four groups; control, GA, CP, and Co-treated group, which received both CP and GA concurrently. The results revealed that CP caused a significant increase in oxidative stress and a decrease in antioxidant levels (CAT, SOD, and GSH), which disturbed the testicular machinery. This caused significant histological and ultrastructural damage to the testicular structure, including atrophied seminiferous tubules with severely reduced germinal epithelium. Additionally, CP caused a decrease in reproductive hormones (testosterone and LH), a decline in nucleic proliferation PCNA immunoexpression, and an increase in cytoplasmic apoptotic Caspase-3 protein expression in testicular tissue, when compared to the control and GA groups. Moreover, The CP treatment impaired spermatogenesis and decreased sperm number and motility with abnormal morphology. However, co-administration of GA with CP mitigated the dysfunction in spermatogenesis and reversed testicular damage caused by CP through significantly (P < 0.01) reducing oxidative stress (MDA) and increasing the activities of CAT, SOD, and GSH. Additionally, co-administration of GA elevated the levels of testosterone and luteinizing hormone in blood sera, significantly (P < 0.01) improved the histometric measurements of seminiferous tubules diameter, their epithelial height, Johnsen's score of spermatogenesis, 4-level histological grading scale Cosentino's score, immunohistochemical expression of nucleic PCNA, and cytoplasmic Caspase-3 proteins. Furthermore, TEM examination confirmed the synergistic effect of GA in restoring the germinal epithelial cells ultrastructure, the elongated and transverse sections of spermatozoa in the lumen, and the interstitial tissue. All of these effects resulted in a significant improvement in sperm quality in the Co-treated animals compared with the CP group, as well as, a significant decline in the morphological abnormalities of sperm in Co-treated rats compared to those in the CP group. GA is a valuable agent for ameliorating chemotherapy-related infertility.

Effect of Venlafaxine, Pramipexole, and Valsartan on Spermatogenesis in Male Rats

The study's aim was to explore the effect of venlafaxine, valsartan, and pramipexole on spermatogenesis. It was hypothesized that these drugs may affect the male fertility because of their long-term use in treatment of depression, hypertension, and Parkinson's diseases. Male rats were given venlafaxine, valsartan, and pramipexole at low- and high-dose levels orally once daily for 10 weeks. Testosterone (25 mg/kg) was given as a standard via an intramuscular route once weekly. Rats were sacrificed after blood collection by cardiac puncture, and testes were removed. Sperm parameters were examined from spermatozoa of the cauda epididymis, and testes were treated for histopathological analysis. Results showed nonsignificant effect of venlafaxine on the sperm count, whereas a decreased sperm count was noted in all the treatment groups as compared to that of the control except valsartan at a low dose, which significantly (p < 0.001) raised the sperm count (96.26 ± 2.4) in reference with the control value (49.13 ± 2.3). Treatments had variable effects on total sperm motility and morphological parameters, but valsartan at a low dose showed maximum sperm motility (71.55 ± 0.7) among all. DNA integrity of spermatozoa remained intact in all groups. Luteinizing hormone and follicle-stimulating hormone levels decreased, and testosterone levels increased in all treatment groups as compared to control values, which indicate fertility. Histopathology revealed normal texture of testes with venlafaxine and valsartan, but testicular damage occurred with high-dose pramipexole. It is concluded that the use of venlafaxine, valsartan, and pramipexole at a low dose is devoid of any harmful effect on spermatogenesis, whereas pramipexole at a high dose adversely affect it.

The Effect of Schisandra chinensis Baillon on Cross-Talk between Oxidative Stress, Endoplasmic Reticulum Stress, and Mitochondrial Signaling Pathway in Testes of Varicocele-Induced SD Rat

Schisandra chinensis Baillon (SC) has been utilized for its antioxidants and anti-inflammatory activities in a broad variety of medical applications. However; SC uses for improving fertility in males and related disorders with proper scientific validation remain obscure. The present study aimed to investigate the effects of SC on varicocele (VC)-induced testicular dysfunction and the potential molecular mechanism associated with VC-induced germ cell apoptosis. The male Sprague–Dawley rats were equally divided into four groups consisting of 10 rats in a normal control group (CTR), a control group administered SC 200 mg/kg (SC 200), a varicocele-induced control group (VC), and a varicocele-induced group administered SC 200 mg/kg (VC + SC 200). Rats were administrated 200 mg/kg SC once daily for 28 days after induction of varicocele rats and sham controls. At the end of the treatment period, body and reproductive organ weight, sperm parameters, histopathological damages, proinflammatory cytokines, apoptosis markers, biomarkers of oxidative stress, endoplasmic reticulum (ER) stress, and steroidogenic acute regulatory protein (StAR) were evaluated. The effects of SC extract on human sperm motility were also analyzed. SC treatment reduces VC-induced testicular dysfunction by significantly increasing testicular weight, sperm count and sperm motility, serum testosterone level, Johnsen score, spermatogenic cell density, testicular superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase level, and steroidogenic acute regulatory protein (StAR) level. Furthermore, the effects of SC on malondialdehyde (MDA) level, reactive oxygen species (ROS)/reactive nitrogen species (RNS) level, apoptotic index, serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, Glucose-regulated protein-78 (Grp 78), phosphorylated c-Jun-N-terminal kinase (p-JNK), phosphorylated inositol-requiring transmembrane kinase/endoribonuclease 1α (p-IRE1α), cleaved caspase 3, and Bax:Bcl2 in VC-induced rats were significantly decreased. Treatment with SC extracts also increased sperm motility in human sperm. Our findings suggest that the SC ameliorate testicular dysfunction in VC-induced rats via crosstalk between oxidative stress, ER stress, and mitochondrial-mediated testicular germ cell apoptosis signaling pathways. SC promotes spermatogenesis by upregulating abnormal sex hormones and decreasing proinflammatory cytokines (interleukin-6; TNF-α).

Can Melissa officinalis improve chromatin structure and sperm parameters in a rat model of varicocele?

Excessive production of reactive oxygen species is a central mechanism in the pathology of varicocele; Melissa officinalis (MO) is a medicinal plant from the Lamiaceae family that has antioxidant activity. In this study, we have investigated the potential therapeutic effect of MO on sperm parameters and chromatin structure in varicocelised rat. Male Wistar rats were randomly assigned to control, sham, varicocele, MO treatment and placebo groups. Rats in varicocele, MO treatment and placebo groups underwent left varicocele induction. Following the operation, rats in placebo and MO treatment groups received normal saline or MO extract, daily for 10 weeks respectively. At 10 weeks after varicocele induction, sperm chromatin and parameters were evaluated in all groups. Chromatin structure was evaluated by aniline blue, acridine orange and toluidine blue staining. All three staining outcomes were increased in varicocele and placebo compared control (and sham) groups (p < 0.05). Sperm count, motility, morphology and vitality were decreased between varicocele and control (and sham) group (p < 0.05). Sperm parameters and chromatin staining (else AB staining) outcomes improve in MO treatment compared to varicocele and placebo groups (p < 0.05). These findings suggest that MO ameliorate the harmful effect of varicocele on sperm parameters and chromatin structure.

Ferulic acid prevents lead-induced testicular oxidative stress and suppressed spermatogenesis in rats

Lead affects multiple organ systems including testis. We investigated the effects of ferulic acid (FA) on lead-induced oxidative stress and spermatogenesis suppression in rats. Animals received lead acetate (500 mg/L in drinking water) and/or FA (50 mg/kg, i.g.) for eight weeks. Lead increased testicular malondialdehyde (MDA) and nitrite levels and decreased glutathione (GSH) content and catalase (CAT) activity. Lead decreased testis weight and testosterone level. Sperm parameters decreased in lead group. FA ameliorated the decreased testis weight, serum testosterone as well as sperm count, viability, motility and normal morphology in lead group. FA improved antioxidant capacity as well as sperm count, viability, motility and normal morphology. FA decreased Johnsen's mean testicular biopsy score (MTBS) criteria by restoring degeneration, atrophy and tubular disarrangement. FA also normalised spermatogonia, spermatocytes and spermatids numbers in lead group and led to increases in number of Leydig and Sertoli cells. FA showed beneficial effects in lead-induced testicular oxidative stress and spermatological disorders, through inhibiting lipid peroxidation and enhancing antioxidant defence systems. The positive effects of FA on Leydig cells may be involved in restoring testosterone levels in lead group. FA can be considered a potential candidate to protect testis against the deleterious effect of lead intoxication.

Saffron improves epididymal sperm parameters in rats exposed to cadmium

Background:

Cadmium (Cd) is known to cause various disorders in the testis. The general population may be exposed to Cd through ingestion of food and drinking water, inhalation of particulates from ambient air, tobacco smoke and ingestion of contaminated soil and dust. Saffron (Crocus sativus L.) is widely used as a food flavour, and has well known medicinal effects.

Objectives:

The aim of this study was to determine the effects of saffron on the results of semen parameters (sperm concentration, motility and viability in cauda of epididymis) in rats exposed to cadmium.

Materials and Methods:

Thirty Wistar male rats were divided into four groups. Cadmium chloride (1 mg/kg body weight) was injected intraperitoneally during 16 days at intervals of 48 hours between subsequent treatments. Crocus sativus L. (100 mg/kg b.w., IP) was pretreated in both control and cadmium-injected rats. Both control and cadmium-injected rats were pretreated with Crocus sativus L. (100 mg/kg b.w., IP). The animals were killed and their sperm count, motility, and vitality were evaluated.

Results:

Sperm parameters did not differ significantly between control and sham groups. Following contamination with cadmium, sperm count, motility and vitality were significantly decreased in comparison to control group (P < 0.05). In pretreated (saffron) group, the sperm parameters improved significantly in comparison with cadmium group (P ≤ 0.05). A significant decrease in sperm motility was observed in Cd-treated rats compared to the control rats. However, no significant changes were recorded by comparison of the control and saffron treated groups except for the sperm motility parameter.

Conclusions:

Saffron, as an antioxidant, is positively effective on sperm parameters in rats exposed with cadmium.

Role of TNF-related apoptosis-inducing ligand (TRAIL) in the pathogenesis of varicocele-induced testicular dysfunction

The higher frequency of varicocele in men with infertility has drawn attention and resulted in increased research at the molecular level towards treatments. The aim of this study was to investigate the role of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its receptors in varicocele-induced testicular dysfunction in an experimental rat model. The rats were divided into three groups: control, sham and varicocele. Varicoceles in rats were induced by partial ligation of the left renal vein and left testes. The rats were analyzed 13 weeks after surgery. The degree of DNA fragmentation within cells in the testis was determined using terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (TUNEL) assay. Tubule degeneration was evaluated using the Johnsen score. The expression of TRAIL and its receptors was detected by immunohistochemical and Western blotting techniques. The apoptotic index, Johnsen score and the expression of TRAIL and TRAIL receptors were examined. The data are presented as the mean±s.d. and were analyzed using computer software. The Kruskal-Wallis and Dunn's multiple comparison tests were used in the statistical analyses. The germ cell apoptotic index was increased in rats with varicoceles when compared with the sham and control groups (P=0.0031). The Johnsen score was significantly decreased in the varicocele group when compared with the sham and control groups (P<0.0001). Immunohistochemical and Western blotting analyses showed that after varicocele induction, the expression of TRAIL-R1 and TRAIL-R4 in germ cells was increased and the expression of TRAIL-R2 was decreased. There are no significant differences among the groups in terms of TRAIL and TRAIL-R3 receptor expression. The results of this study indicate that TRAIL and its receptors may have a potential role in the pathogenesis of varicocele-induced testicular dysfunction.

The hypoxic testicle: physiology and pathophysiology

Mammalian spermatogenesis is a complex biological process occurring in the seminiferous tubules in the testis. This process represents a delicate balance between cell proliferation, differentiation, and apoptosis. In most mammals, the testicles are kept in the scrotum 2 to 7°C below body core temperature, and the spermatogenic process proceeds with a blood and oxygen supply that is fairly independent of changes in other vascular beds in the body. Despite this apparently well-controlled local environment, pathologies such as varicocele or testicular torsion and environmental exposure to low oxygen (hypoxia) can result in changes in blood flow, nutrients, and oxygen supply along with an increased local temperature that may induce adverse effects on Leydig cell function and spermatogenesis. These conditions may lead to male subfertility or infertility. Our literature analyses and our own results suggest that conditions such as germ cell apoptosis and DNA damage are common features in hypoxia and varicocele and testicular torsion. Furthermore, oxidative damage seems to be present in these conditions during the initiation stages of germ cell damage and apoptosis. Other mechanisms like membrane-bound metalloproteinases and phospholipase A2 activation could also be part of the pathophysiological consequences of testicular hypoxia.

Folic acid alleviates oxidative stress and hyperhomocysteinemia involved in testicular dysfunction of hypothyroid rats

Although there is general agreement that thyroid hormone is an important hormonal regulator of testis physiology during development period, its role in the post-pubertal and adult testes is still controversial. Furthermore, most experimental studies to date have focused on thyroid hormone effects on the developing testes and only limited data are available on its role in spermatogenesis. This study evaluated some biochemical alterations in post-pubertal hypothyroidism and its impact on testicular function. Additionally, the ameliorating role of folic acid supplementation was investigated. Fifty male albino rats were randomly divided into five groups (group I, control; group II, folic acid; group III, 0.05% propylthiouracil-induced hypothyroid rats; group IV, co-treatment; group V, post-treatment). Plasma total homocysteine, total NO metabolites, malondialdehyde and GSSG/GSH ratio quantified by HPLC significantly (P<0.05) increased in hypothyroid rats as compared to controls. These biochemical alterations at least in part disrupted spermatogenesis in these experimental models. Folic acid supplemented after restoration of the euthyroid state (group V) presented better amelioration to spermatogenesis over its concurrent supplementation (group IV). This postulates an indirect negative impact of post-pubertal hypothyroidism on testicular function through development of these alterations. This is plus the observed role of folic acid supplementation in enhancing spermatogenesis, boosting sperm concentration and building up the antioxidant status against the oxidants in the present study. If confirmed in human beings, our results could propose that folic acid can be used as an adjuvant therapy in hypothyroidism disorders with thyroxin replacement therapy.

Ram Sperm Motility Parameters under The Influence of Epidermal Growth Factor

Epidermal growth factor (EGF) is one of the important cytokines that play a role in fertility. It is known that EGF affects both male and female reproduction, but its effect on sperm parameters is not fully understood. Up to the present, the effect of EGF on ram sperm motility parameters has not been published. We analyzed motility parameters of ejaculates after 24, 48, and 72 hours from the EGF addition. EGF was added to chilled ram sperm at concentrations of 0, 100, 200, and 400 ng·ml⁻¹. Analyses were realized using computer, assisted semen analyzer (CASA)—Hamilton Thorn motility analyzer (version 7). The effect of EGF was already visible after 30 min of incubation. Significant effect on ram sperm total motility and progressive movement was observed at higher EGF concentrations after 48 h of incubation. Our results show that EGF affects sperm motility parameters depending on concentration and time of exposure.

Protease activated receptor 2 and epidermal growth factor receptor are involved in the regulation of human sperm motility

AIM

To investigate mechanisms of tryptase-induced reduction of sperm motility and explore whether epidermal growth factor receptor (EGF-R) and protease activated receptor 2 (PAR-2)- associated pathways are involved.

METHODS

Fresh semen was collected from healthy donors (n = 15). Semen parameters and quality were assessed in accordance with the World Health Organization (WHO) criteria. Swim-up sperm were fixed and subjected to immunocytochemistry and immunoelectronmicroscopy with specific antibodies directed against PAR-2 and EGF-R. Protein extractions from swim-up spermatozoa were analyzed by Western blotting with antibodies for both receptors. Motility of spermatozoa was evaluated by computer-assisted semen analysis.

RESULTS

Immunocytochemistry found PAR-2 and EGF-R in approximately 30% of examined human ejaculated spermatozoa. Both receptors were localized in the plasma membrane. Like tryptase, the PAR-2 synthetic agonist SLIGKV reduced sperm motility, and this effect was inhibited by application of two specific EGF-R pathway blockers (AG1478 and PD168393).

CONCLUSION

The observed reduction of sperm motility by tryptase through the PAR-2 receptor involves EGF-R pathways.