The effect of vascular endothelial growth factor on spermatogenesis and apoptosis in experimentally varicocele-induced adolescent rats

Insulin-like growth factor-1 promotes the testicular sperm production by improving germ cell survival and proliferation in high-fat diet-treated male mice

BACKGROUND

A decrease in semen volume among men is comparable to the rising prevalence of obesity worldwide. The anabolic hormone insulin-like growth factor-1 (IGF-1) can promote proliferation and differentiation in cultured mouse spermatogonial stem cells and alleviate abnormal in vitro spermatogenesis. Additionally, serum IGF-1 level is negatively correlated with body mass index. Whereas the role of IGF-1 in the sperm production in obese men remains unclear.

OBJECTIVE

To investigate the therapeutic effect and potential mechanism of IGF-1 on spermatogenesis of high-fat diet (HFD)-induced obesity mice.

METHODS

An HFD-induced obesity mouse model was established. Alterations in testicular morphology, sperm count, proliferation, and apoptosis were observed by H&E staining,immunohistochemistry, immunofluorescence, and Western blotting. Exogenous recombinant IGF-1 was administered to obese mice to investigate the correlations between altered testicular IGF-1 levels and sperm production.

RESULTS

The sperm count was reduced, the testicular structure was disordered, and sex hormone levels were abnormal in HFD-fed mice compared with normal diet-fed mice. The expression of proliferation-related antigens such as proliferating cell nuclear antigen (PCNA) and Ki-67 was decreased, while that of proapoptotic proteins such as c-caspase3 was increased in testes from HFD-fed mice. Most importantly, the phosphorylation of insulin-like growth factor-1 receptor (IGF-1R) in testes was decreased due to reductions in IGF-1 from hepatocytes and Sertoli cells. Recombinant IGF-1 alleviated these functional impairments by promoting IGF-1R, Akt, and Erk1/2 phosphorylation in the testes.

CONCLUSIONS

Insufficient IGF-1/IGF-1R signaling is intimately linked to damaged sperm production in obese male mice. Exogenous IGF-1 can improve survival and proliferation as well as sperm production. This study provides a novel theoretical basis and a target for the treatment of obese men with oligozoospermia.

Mean platelet volume might be an effective indicator of poor semen quality in varicocele patients

OBJECTIVE

To delve into the relationship between mean platelet volume (MPV) and semen quality in patients with varicocele.

MATERIALS AND METHODS

A total of 246 varicocele patients and 120 healthy adult males were enrolled. Physical examinations and the color Doppler ultrasonography were conducted on patients with varicocele to confirm the diagnosis. Venous blood samples and semen samples were collected from all participants for subsequent analysis. A series of statistical analyses were conducted to assess the relationship between their MPV levels and semen quality. A series of statistical analyses were performed to assess the relationship between MPV and semen quality.

RESULTS

No statistically significant differences were found between body mass index (BMI), sexual hormones, semen volume, platelet count, and right testicular volume in all three groups (health subjects, varicocele without symptoms, and varicocele with infertility). When conducting regression analysis on two groups with varicocele, the results indicated that a lower MPV is associated with a reduced risk of varicocele accompanied by infertility (OR = 0.557 95% CI: 0.432-0.719, P < 0.001). Further correlation analysis in varicocele patients revealed that high MPV had a statistically negative impact on the occurrence of poor semen quality, affecting sperm concentration, progressive motility, and morphology (all P < 0.001). More importantly, when predicting varicocele associated with infertility, MPV demonstrated high diagnostic sensitivity (AUC = 0.745, P < 0.001).

CONCLUSION

Our results indicate that MPV is higher in varicocele with infertility and is closely related to semen quality, which may suggest an accompanying decline in semen quality associated with varicocele. However, these conclusions require further experimental validation.

Impact of Varicocele on Testicular Oxidative Stress and Sperm Parameters in Experimental Animals: A Systematic Review and Meta-Analysis

PURPOSE

Varicocele has been associated with high seminal oxidative stress (OS), impaired semen quality, and reduced male fertility potential. However, the exact mechanism(s) underlying the development of varicocele-mediated infertility and the cause-effect relationship between varicocele and testicular dysfunction are not fully understood. The aim of this systematic review and meta-analysis (SRMA) is to investigate the impact of varicocele on testicular OS markers and sperm parameters in experimental animals with varicocele as compared to animals without varicocele.

MATERIALS AND METHODS

A literature search was performed using the Scopus and PubMed databases on studies that investigated testicular OS markers and sperm parameters in animals with varicocele. The primary outcomes included malondialdehyde (MDA) (nmol/mg) levels whereas the secondary outcomes included total sperm count (×106), sperm vitality (%), total sperm motility (%), and sperm DNA fragmentation (SDF) (%). Standardized mean difference (SMD) (95% confidence interval [CI]) was chosen to express the effect size. The quality of the included studies was evaluated using the Cambridge Quality Checklist.

RESULTS

Out of 76 identified articles, 6 studies on rats were included in the meta-analysis. The analysis showed a significant increase of MDA (SMD: 15.61 [1.93, 29.29]; p=0.03) in rats with varicocele vs. controls. We also observed a significant decrease in total sperm count (SMD: -17.45 [-28.97, -5.93]; p<0.01), sperm vitality (SMD: -16.41 [-26.30, -6.52]; p<0.01), total sperm motility (SMD: -17.67 [-24.90, -10.44]; p<0.01), and a significant increase of SDF (SMD: 7.41 [1.23, 13.59]; p=0.02), in rats with varicocele vs. controls. The quality of the included studies was ranked as high.

CONCLUSIONS

This SRMA indicates a significant increase in levels of testicular MDA and SDF and a reduction of sperm quality in experimental animals with varicocele. These findings support the potential role of testicular OS in the development of varicocele-induced testicular damage.

Role of Oxidative Stress in Varicocele

According to the official statistics of the World Health Organization, at least 48 million couples and 186 million people suffer from infertility. Varicocele has been recognized as the leading cause of male infertility and can affect spermatogenesis and cause testicular and epididymal disorders through multiple diverse pathophysiological processes. Reactive oxygen species (ROS) produced by oxidative stress have been reconciled as an important pathogenic factor throughout the course of varicocele. Testis respond to heat stress, hypoxia, and inflammation at the cost of producing excessive ROS. High levels of ROS can lead to infertility not only through lipid peroxidation or DNA damage, but also by inactivating enzymes and proteins in spermatogenesis. This review studies the oxidative stress and its role in the pathophysiology and molecular biology of varicocele in the context of a decline in fertility.

Minocycline can reduce testicular apoptosis related to varicocele in male rats

The current research aimed to assess the impacts of Minocycline on varicocele-induced regulation of apoptotic-related genes and oxidative stress in the testis of adult Wistar rats. Thirty-two rats were divided into 4 groups: sham, varicocele (VcI), varicocele treated with Minocycline (VcI + Mno) for 56 days and healthy rats treated with minocycline (Mno). After 8 weeks, the oxidative stress markers levels in serum were investigated, afterwards, the level of Bax and Bcl-2 expression were assessed through 'immunocytochemistry' and RT-qPCR assays. Also, the rate of apoptosis was evaluated through the TUNEL method. Johnson's score, 'the width of epithelium' and 'seminiferous tubules diameter' were ameliorated in the VcI + Mno group in comparison with the Vcl group. Administration of Minocycline raised the 'Glutathione peroxidase' and 'Superoxide dismutase' levels in serum and declined the Malondialdehyde level in serum (p = 0.001). Furthermore, current study represented that minocycline reduced Bax and enhanced the expression of Bcl-2 gene and protein in comparison with the Vcl group (p < 0.05). In addition, Minocycline administration significantly declined the rate of apoptosis in germ cells (p < 0.05). Our study demonstrated that the administration of Minocycline could improve testicular injury in varicocele-induced rats by its antioxidant activity.

Thymoquinone improves testicular damage and sperm quality in experimentally varicocele-induced adolescent rats

The aim of this study was to investigate the protective and therapeutic effects of thymoquinone against the negative effects of varicocele on testicular tissue and sperm morphology. Five groups were formed by random selection from a total of 40 adult male Wistar rats (n = 8). Thymoquinone (5 mg/kg/day) was administered intraperitoneally to the varicocele-dimethyl sulfoxide-olive oil-thymoquinone (VT) group and the sham-thymoquinone group. At the end of the 60th day, all groups were anaesthetised and the left testis was removed from the body quickly. One half of the testis tissue, which was divided into two, was separated for biochemical and Western blot analysis, while the other half were fixed in Bouin's fixative. As a result of biochemical, molecular and histopathological analyses, a statistically significant increase was found in the varicocele group testicular tissues in the malondialdehyde level, apoptotic index, Bax expression, cytochrome c expression and Bax/Bcl-2 ratio compared with the sham group. In addition, histopathological changes characterised by partial or complete degeneration of the germinal epithelium were observed in the seminiferous tubules in the same group. Total oxidant status level and sperm count with abnormal morphology increased in varicocele group, whereas total antioxidant status level decreased. In the VT group, all of the biochemical, molecular and histopathological changes detected in the varicocele group were statistically significantly reduced. When the findings obtained in this study are evaluated, it can be said that thymoquinone has the potential to be used as a preventive and therapeutic pharmacological agent in the medical treatment of varicocele. Although the exact mechanism of action of thymoquinone has not been fully elucidated, the findings obtained in this study support the view that thymoquinone showed a cytoprotective effect by reducing apoptosis, oxidative stress and lipid peroxidation.

What is the role of pre-operative blood parameters in forecasting varicocelectomy success?

BACKGROUND

We aimed to examine the effects of pre-operative blood values on varicocelectomy success.

MATERIALS AND METHODS

A total of 130 patients who underwent varicocelectomy in our clinic were retrospectively analyzed. Operation success was defined as the return of all semen parameters (concentration, progressive motility, and morphology) to normal values 6 months after surgery. The patients were separated as two groups as benefiting from the treatment (Group A) and not (Group B).

RESULTS

The best cut-off value for the neutrophil/lymphocyte ratio (NLR), which can predict varicocelectomy success, was assigned to be 2.27, with AUC of 0.859 (%95 CI 0.795-0.922). The highest sensitivity and specificity were 0.857 and 0.731 (p < 0.001). The best cut-off value for the mean platelet volüme (MPV) value, which can predict varicocelectomy success, was assigned to be 9.45, with AUC of 0.729 (%95 CI 0.639-0.819). The highest sensitivity and specificity were 0.655 and 0.635 (p < 0.001). Binary logistic regression analysis showed NLR ratio (odds ratio (OR): 11.2, p < 0.001) and MPV (OR: 2.65, p = 0.002) parameters as independent predictive factors in predicting varicocelectomy success.

DISCUSSION AND CONCLUSION

Our study showed that low NLR ratio (≤2.27) and high MPV (≥9.45) ratio levels may be a useful pre-operative predictive tool in identifying men who benefit most from varicocelectomy in infertile patients with varicocoele.

Expression of vascular endothelial growth factor and its receptors in infertile men with varicocele

OBJECTIVES

An enlargement of the spermatic vein is known as a varicocele. Research studies suggest that immune system mediators such as vascular endothelial growth factor (VEGF) and its receptors including VEGFR1, VEGFR2, and VEGFR3 can play a role in angiogenesis and inhibition of endothelial cell apoptosis and correspondingly suppress spermatogenesis. Thus, the purpose of this study was to measure the expression of VEGF and its receptors in infertile men with varicocele.

MATERIALS & METHODS

To meet the research objectives, a total number of 30 infertile male patients affected with varicocele (Grade 3) and 30 healthy fertile male subjects without any varicocele or urogenital tract disorder were enrolled in the study. The varicose and normal veins were obtained from the patients along with the blood flowing in these spermatic veins during surgery. Also, peripheral blood samples were collected from the mentioned patients and healthy subjects. The serum levels of VEGF were also measured via enzyme-linked immunosorbent assay (ELISA) and subsequently mRNA level of VEGFR1, VEGFR2, VEGFR3, B Cell Lymphoma-Associated X (Bax), and B-cell lymphoma 2 (Bcl2) genes were measured using the real-time polymerase chain reaction (RT-PCR) technique.

RESULTS

The findings of this study revealed that VEGFR2 gene expression in varicose veins was significantly increased compared with normal veins in varicocele patients (P < 0.001) and Bax/Bcl2 ratio reduced in varicose veins when compared to normal veins of the patients (P < 0.05). Our findings also showed a significant rise in the serum levels of VEGF in the peripheral blood and varicose vein bloodstream compared with those in healthy subjects (P < 0.0001). Moreover, a significant difference was observed in the serum levels of VEGF in the peripheral blood and varicose vein blood of patients suffering from varicocele (P < 0.001).

CONCLUSION

According to the results of this study, VEGF/VEGFR2 axis might act in the survival of endothelial cells of varicocele vein through inhibition of apoptosis and stimulation of angiogenesis. Additionally, increased VEGF in the testis can probably play a role in suppressing spermatogenesis and varicocele-based infertility.

Combination of Korean Red Ginseng Extract and Hydrogen-Rich Water Improves Spermatogenesis and Sperm Motility in Male Mice

OBJECTIVE

To investigate the effect of hydrogen-rich Korean Red Ginseng (KRG) water (HRGW) mixture on the spermatogenesis and sperm motility of mice of different ages.

METHODS

Eighty young (3 month-old) and aged (12 month-old) male mice were randomly assigned to 4 groups (n =10 per group) including control group, hydrogen-rich water (HRW) group (10 mL/kg daily), KRG group (50 mg/kg daily) and HRGW group (10 mL/kg and 50 mg/kg daily) by an oral zoned needle for 4 weeks. Sperm count and motility were measured using sperm suspension released from cauda epididymis. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and reactive oxygen species (ROS) in serum have also been estimated. Tubular changes were examined through histological hematoxylin and eosin staining. Expression of antioxidation (PPx3, PPx4, GSTm5 and GPx4), spermatogenesis (inhibin-a, neptin-2 and CREM), antiaging (SIRT1 and SIRT2), and angiogenesis [visfatin and vascular endothelial growth factor (VEGF)] related genes were examined through real-time polymerase chain reaction.

RESULTS

HRW and KRG treatment stimulated spermatogenesis followed by increasing sperm production and sperm motility (P <0.05). These effects were strengthened synergistically by a HRGW mixture (P <0.05 or P <0.01). HRGW greatly increased the expressions of antioxidation, antiaging, spermatogenesis related genes and VEGF especially in aged mice (P <0.05). Serum testosterone and FSH levels also increased, while serum ROS level decreased (all P <0.05).

CONCLUSION

HRGW increases sperm production and motility by enhancing antioxidation and stimulating spermatogenesis and sex hormone production, particularly in aged mice.

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).

Hesperidin attenuated apoptotic-related genes in testicle of a male rat model of varicocoele

BACKGROUND

Varicocoele is a swollen bulge of the pampiniform venous plexus inside the scrotum. It is also considered one of the causes of infertility in males. It has been demonstrated that hesperidin has remarkable pharmacological potentials, including antioxidant, anti-inflammatory, antimicrobial, and anticarcinogenic effects.

OBJECTIVE

The present study aimed to evaluate the protective effect of hesperidin on varicocoele-induced testicular tissue damage and oxidative stress in the testicles of adult male rats.

MATERIALS AND METHODS

Animals were assigned into the following groups: control group (Ctrl) or sham, varicocoele group (Vcl) which received no treatment, varicocoele group that was daily fed with hesperidin (Vcl+Hsp) at a dose of 50 mg/kg for eight weeks, and hesperidin group (Hsp) which received only hesperidin. At the end of the treatment period, the levels of oxidative stress markers were measured in plasma, and the expression of Bax and Bcl-2 was determined by immunocytochemistry and RT-qPCR methods. The index of apoptosis was assessed by the TUNEL assay.

RESULTS

Johnsen's score, the epithelium thickness, and diameter of seminiferous tubules were improved in the Vcl+Hsp group as compared to the Vcl group. Treatment with hesperidin enhanced the serum levels of glutathione peroxidase (GPx) and superoxide dismutase (SOD) enzymes and decreased the heightened concentrations of malondialdehyde (MDA) in testicular tissue (p < 0.001). Moreover, our results demonstrated that hesperidin considerably diminished Bax and increased Bcl-2 expression (gene and protein) levels compared with the Vcl group (p < 0.05). It also markedly reduced the rate of programmed cell death in germ cells (p < 0.05).

CONCLUSIONS

It seems that the treatment with hesperidin could mitigate testicular tissue damage in rats underwent varicocoele possibly through its antioxidant properties.

Morinda Officinalis Polysaccharides Attenuate Varicocele-Induced Spermatogenic Impairment through the Modulation of Angiogenesis and Relative Factors

Evidence supporting best treatment practices for varicocele is lacking. The effects of a water-soluble polysaccharide extracted from Morinda officinalis (MOP) on the progression of varicocele were evaluated in the present study. The extracted MOP was confirmed as having a high purity of 98% with scant protein contamination, and it mainly consisted of glucose, lactose, and xylose at a molar ratio of 7.63:1.23:0.95 glucose:lactose:xylose. MOPs were administered to experimental left varicocele rats immediately after surgery at doses ranging from 25 to 200 mg/kg. As detected by sperm analysis and histopathological staining, the intragastric administration of 100 mg/kg MOPs significantly improved the sperm parameters of bilateral cauda epididymis, attenuated seminiferous epithelial structures, and inhibited germ cell apoptosis. The results of immunofluorescence and immunoblot showed that administration of 100 mg/kg MOPs effectively inhibited angiogenesis in the bilateral testes but modulated the expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase 2 (MMP2), and MMP9 mildly. These results indicate that inhibition of angiogenesis may be one of the mechanisms by which MOP exerts its inhibitive activities on the progression of varicocele, whereas a relative upregulation of VEGF and MMP-9 may be crucial for the spermatogenetic protective effects of 100 mg/kg MOP administration.

Effect of varicocelectomy treatment on spermatogenesis and apoptosis via the induction of heat shock protein 70 in varicocele‑induced rats

In the current study, the hypothesis that testicular varicocelectomy improves spermatogenesis and attenuates apoptosis via the induction of heat shock protein 70 (Hsp70) in a rat model of varicocele was investigated. Adult male Wistar rats (n=75) were randomly divided into 5 groups of 15 each: Control, sham, varicocele, varicocelectomy, and varicocelectomy plus Quercetin. A total of 6 weeks after the varicocelectomy, the left testis of all rats was removed for subsequent examination. Histological changes were compared between the groups. The expression of Hsp70 and apoptosis‑associated indicators were evaluated based on immunohistochemical, western blot and mRNA expression analyses. Compared with the varicocele group, the varicocelectomy group exhibited a markedly reduced Bcl‑2‑associated X protein/B‑cell lymphoma 2 (Bax/Bcl‑2) ratio, and had a decreased expression of caspase‑9, cytochrome c (cyt c) and caspase‑3 through the intrinsic signal transduction pathways. Quercetin treatment inhibited the protective effects of varicocelectomy. The expression of Hsp70 was increased in the varicocele group which was further elevated by the varicocelectomy. These results indicated that varicocelectomy can reduce the Bax/Bcl‑2 ratio, and decrease the levels of caspase‑9, cyt c and caspase‑3 via the mitochondrial signal transduction pathway. Such protective effects on left testis spermatogenesis and against apoptosis may be due to the induction of Hsp70. The findings of the present study suggested that varicocelectomy has a clear advantage in protecting testicular function and ameliorating spermatogenic cells apoptosis.

The effect of the degree of left renal vein constriction on the development of adolescent varicocele in Sprague-Dawley rats

Experimental models have allowed inquiry into the pathophysiology of varicocele (VC) beyond that possible with human patients. A randomized controlled study in rats was designed to clarify the influence of the degree of left renal vein constriction on the development of adolescent VC. Fifty adolescent male Sprague–Dawley rats (Rattus norvegicus) were randomly assigned to five groups of 10: the experimental groups (I–IV) underwent partial ligation of left renal veins with 0.5-, 0.6-, 0.7-, and 0.8-mm diameter needles, respectively. The control group (V) underwent a sham operation. The diameter of the left spermatic vein (LSV) was measured at baseline and 30 days postoperatively. In addition, the lesion of the left kidney was examined with the naked eye and assessed by Masson's trichrome staining. VC was successfully induced in 2 (20%), 4 (40%), 7 (70%), and 10 (100%) rats in groups I–IV, respectively. The other rats failed to develop VCs primarily due to left renal atrophy. No VC was observed in group V. The postsurgical LSV diameters in VC rats in groups III and IV were 1.54 ± 0.16 and 1.49 ± 0.13 mm, respectively (P > 0.05), and their increments were 1.36 ± 0.10 and 1.31 ± 0.10 mm, respectively (P > 0.05). These results suggest that suitable constriction of the left renal vein is critical for adolescent VC development. In addition, the 0.8-mm diameter needle may be more suitable for inducing left renal vein constriction in adolescent rat models.

A Combination of a GnRH Antagonist and Agonist for Fertility Preservation in an Adolescent Female Murine Model

Recent studies have suggested that GnRH agonists (GnRHags) protect ovarian function following chemotherapy. Here, we study the effect of a combination of GnRH antagonist (GnRHan) and GnRHag for gonadal protection from gonadotoxic chemotherapy in adolescent female rats. Cycling Sprague Dawley rats were treated at adolescent age. Thirty female rats were randomized to 5 treatment groups (n = 6/group): (1) placebo, (2) cyclophosphamide (CPA) alone, (3) GnRHan followed by GnRHag with placebo, (4) GnRHan followed by GnRHag with CPA, and (5) GnRHag with CPA. The main outcome measure was live birth rate (LBR), and secondary measures included rat weight, ovarian volume, and follicles. Group 2 had decreased LBR compared to all other groups. Group 4 and 5 had LBR similar to placebo. There was no difference in the ovarian volume. The CPA-alone group had decreased number of antral follicles compared to control. These studies demonstrate that the combination of GnRHan and GnRHag and GnRHag alone preserved fertility in female adolescent rats following gonadotoxic chemotherapy treatment. The addition of a GnRHan to a GnRHag does not confer a greater protective effect.

Role of Inhibitors of Apoptosis Proteins in Testicular Function and Male Fertility: Effects of Polydeoxyribonucleotide Administration in Experimental Varicocele

Neuronal apoptosis inhibitory protein (NAIP) and survivin might play an important role in testicular function. We investigated the effect of PDRN, an agonist of adenosine A2A receptor, on testicular NAIP and survivin expression in an experimental model of varicocele. After the creation of experimental varicocele (28 days), adolescent male Sprague-Dawley rats were randomized to one of the following treatments lasting 21 days: vehicle, PDRN (8 mg/kg i.p., daily), PDRN + 3,7-dimethyl-propargylxanthine (DMPX, a specific adenosine A2A-receptor antagonist, 0.1 mg/kg i.p., daily), varicocelectomy, and varicocelectomy + PDRN (8 mg/kg i.p., daily). Sham-operated animals were used as controls. Animals were then euthanized and testis expression of NAIP and survivin was evaluated through qRT-PCR, western blot, and immunohistochemical analysis. Spermatogenetic activity was also assessed. NAIP and survivin expressions were significantly reduced following varicocele induction when compared to sham animals whereas PDRN-treated rats showed an increase in NAIP and survivin levels. Immunohistochemistry revealed an enhanced expression of NAIP and survivin with a characteristic pattern of cellular localization following PDRN treatment. Moreover, administration of PDRN significantly restored spermatogenic function in varicocele rats. PDRN may represent a rational therapeutic option for accelerating recovery from depressed testicular function through a strategic modulation of apoptosis in experimental varicocele.

Angiogenesis inhibition impairs testicular morphology in experimental left varicocele rat model

INTRODUCTION

It has been reported that varicocele might promote angiogenesis. However, it is not clearly identified how angiogenesis affect testicular morphology or spermatogenic activity. The objective of the study is to investigate the effect of spironolactone, as an angiogenesis inhibitor, on the ipsilateral testis morphology in left varicocele-induced rats.

MATERIALS AND METHODS

Twenty four adult (12-14 mo), male Wistar albino rats were randomly assigned to four groups (n=6, for each): 1. Control group, 2. Sham-operated group, 3. Experimental left varicocele group and, 4. Spironolactone (20mg/kg/day)-treated experimental left varicocele group. Histopathological findings in rat testis were investigated.

RESULTS

Microvessel density increased in varicocele group and spironolactone inhibited angiogenesis neither by antimineralocorticoid, nor by antiandrogenic effect. However, spermatogenesis impaired in spironolactone treated varicocele group.

CONCLUSION

Angiogenesis seems to be a protective process in varicocele. Spironolactone treatment, probably by inhibiting angiogenesis, impairs testicular morphology.

Evaluation of heat-shock protein A2 (HSPA2) in male rats before and after varicocele induction

Varicocele is a major cause of infertility and may impair spermatogenesis. This study evaluated the molecular consequences of varicocele on the induction of heat-shock proteins, intracellular chaperones involved in stress responses, and of the ubiquitin-proteasome system, which is participates in the removal of defective sperm in the testis and epididymis. Wistar rats were randomly divided into three groups: surgically induced left varicocele, sham-operated, and untreated controls. Two months after surgery, we observed significantly reduced sperm parameters, DNA integrity, and protamine content in the sperm retrieved from the left epididymis compared to the right epididymis in the varicocele group, as well as compared to sperm retrieved from the left epididymis of the sham and control groups. According to Western blot analysis, we observed significantly higher HSPA2 expression in testicular tissue from the left testis compared to the right testis in the varicocele group or the left testis of the control group. Immunohistochemical analysis showed that expression of HSPA2 was higher in the round spermatid and sperm from the left varicocele compared to the control group. There was normally less HSPA2 expressed in the caput and corpus compared to the cauda of the epididymis in the control group, but this pattern was altered in the caput epididymis of the varicocele group. Levels of ubiquitination were also remarkably lower in the left testis of the varicocele group. Therefore, varicocele impacts expression of HSPA2 and ubiquitination.

Dietary cholesterol and oxidised cholesterol: effects on sperm characteristics, antioxidant status and hormonal profile in rats

Present study was designed to compare the potential effects of high serum levels of LDL and oxidised LDL (OxLDL) on spermatogenesis parameters in male Wistar rats. Animals were allocated into three groups and were fed for 14 weeks with normal, cholesterol-rich and oxidised cholesterol-rich diets. Blood lipid profile, sex hormones level, as well as sex organs weight were evaluated. The sex organs weight in oxidised cholesterol-fed group was significantly reduced (P < 0.05). Spermatozoa count in the group with high serum concentration of OxLDL (64 ± 4.2 × 10(6) ) was markedly lower (P < 0.01) than that of normal rats (87 ± 4.1 × 10(6) ) and rats with high serum level of LDL (90 ± 6.3 × 10(6) ). Similarly, the percentage of viable spermatozoa was significantly (P < 0.001) decreased from 78% to 52% by high level of OxLDL in serum. While, nonoxidised LDL did not have suppressive effects on spermatogenesis and organs weight. Consistent with these effects, the serum concentration of sex hormones including FSH (P < 0.001), LH (P < 0.001) and testosterone (P < 0.01) was significantly decreased only in rats with high level of OxLDL but not in rats with high level of nonoxidised LDL. In conclusion, high OxLDL level showed higher destructive effect on reproductive system compared to the high LDL level.

The role of animal models in the study of varicocele

Varicocele is the most common correctible cause of male infertility and is present in 15% to 20% of the male population. Despite its prevalence, the pathophysiology of varicocele remains under investigation. One of the largest obstacles in studying varicocele is that it is almost exclusively found in humans. This has necessitated the creation of an animal model of varicocele. The most commonly used animal model involves the creation of a varicocele in a rodent by partially occluding the left renal vein. This model has provided a significant amount of data on varicocele, and a modification of this model utilizing microsurgery appears even more promising. Animal models have proven critical to investigating the pathophysiology of varicocele.

Experimental varicocoele in rats affects mechanisms that control expression and function of the androgen receptor

Varicocoele is an important cause of male infertility. Normal male reproductive function and fertility depends on a delicate balance between androgen receptor (AR) and the classic oestrogen receptors ESR1 (ERα) and ESR2 (ERβ). Using a model of surgically induced varicocoele in rats, this study aimed to investigate the effects of varicocoele on the expression of AR, ESR1, ESR2 and G-protein coupled oestrogen receptor (GPER). Varicocoele did not affect the mRNA and protein expression of ESR1 and ESR2 in both testes. Varicocoele did not affect the mRNA and protein expression of GPER in the right testis, but slightly reduced the mRNA and increased the protein levels in the left testis. Varicocoele did not affect the mRNA for AR, but reduced the protein levels in both testes. A proteomic approach was used in an attempt to find differentially expressed targets with possible correlation with AR downregulation. Varicocoele caused the differential expression of 29 proteins. Six proteins were upregulated, including the receptor for activated C kinase 1 (RACK1), and 23 were downregulated, including dihydrolipoamide dehydrogenase, alpha-enolase and pyrophosphatase 1. Western blot analysis confirmed that varicocoele upregulated the expression of RACK1, a protein involved with tyrosine phosphorylation and regulation of AR transcriptional activity, AR metabolism and dynamics of the blood-testis barrier. In conclusion, this study suggests that varicocoele affects mechanisms that control AR expression and function. This regulation of AR may play an important role in the varicocoele-induced testicular dysfunction. Furthermore, varicocoele downregulates several other proteins in the testis that may be useful markers of spermatozoa function and male infertility.

Impact of micronised purified flavonoid fraction on increased malondialdehyde and decreased metalloproteinase-2 and metalloproteinase-9 levels in varicocele: outcome of an experimentally induced varicocele

To analyse the levels of an indirect marker of ROS-induced lipid peroxidation [i.e. malondialdehyde (MDA)] in both testes and the levels of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and matrix metalloproteinase inhibitor-1 (TIMP-1) in the left testis after induction of varicocele and investigated the impact of micronised purified flavonoid fraction (MPFF) on these markers. Forty-nine adolescent (6-week-old) male Wistar rats were included in this study. The rats were divided into seven groups as follows:Group-1, control; Group-2, sham; Group-3, left varicocele-induced; Group-4, varicocele + varicocelectomy + MPFF-treated (for 4 weeks); Group-5, varicocele + MPFF-treated (for 8 weeks); Group-6, varicocele-induced and 4 weeks later, MPFF-treated (for 4 weeks); and Group-7, varicocele + varicocelectomy. MDA was measured in the tissues of both testes using the thiobarbituric acid reactivity method. The ELISA method was used for the quantification of MMP-2, MMP-9 and TIMP-1 in the left testicular tissue. The levels of MDA were significantly higher in the varicocele group than in the other groups. The MDA levels in the left testicular tissues of Group-7 were significantly higher than those of Group 4 (P = 0.03). In the varicocele group, the MMP-2 and MMP-9 levels decreased, whereas the levels of TIMP-1 increased. The tissue levels of MMP-2 in Groups 4, 5 and 7 were significantly higher than those in Group 1 (P < 0.05).

The effect of micronized purified flavonoid fraction on the prevention of testicular pathologies in adolescent rats with experimentally induced varicocele

PURPOSE

We investigated the effect of micronized purified flavonoid fraction on the prevention of testicular pathologies following varicocele induction.

MATERIALS AND METHODS

A total of 66 adolescent (6-week-old) male Wistar rats were included in study. Rats were divided into 7 groups, including group 1--control, group 2--sham operation, group 3--left varicocele induced, group 4--varicocele induced, varicocelectomy done 4 weeks later and micronized purified flavonoid fraction administered for 4 weeks, group 5--varicocele induced and micronized purified flavonoid fraction administered for 8 weeks, group 6--varicocele induced and beginning 4 weeks later micronized purified flavonoid fraction administered for 4 weeks, and group 7--varicocele induced and varicocelectomy done 4 weeks later. Before sacrifice bilateral real-time testicular microvascular perfusion of all rats was measured using the PeriFlux System 5000 PF 5010 LDPM Unit (Perimed, Järfälla, Sweden). All testes were graded according to the Johnsen scoring system. To assess apoptosis caspase-3 levels were measured.

RESULTS

Testicular weight in group 3 was markedly decreased and the extent of seminiferous tubular damage was significantly increased compared with the other groups. Bilateral testicular blood flow and the number of apoptotic germ cells were greater in group 3. Significantly higher Johnsen scores and a meaningful decrease in the apoptotic index were detected in groups 4 to 7 compared with group 3.

CONCLUSIONS

We observed favorable effects of micronized purified flavonoid fraction on the regression of testicular damage secondary to varicocele.

Polydeoxyribonucleotide administration improves the intra-testicular vascularization in rat experimental varicocele

OBJECTIVE

To study the effect of PDRN on angiogenesis in a model of varicocele in rats.

DESIGN

After the creation of experimental varicocele, rats were randomized to one of the four treatments: vehicle, PDRN, DMPX, and PDRN plus DMPX. Twenty-one days after randomization, all animals were euthanized and the left testis was harvested.

SETTING

Academic hospital.

ANIMAL(S)

Male Sprague-Dawley rats were used.

INTERVENTION(S)

A clamp was passed behind the left renal vein distally to the spermatic vein insertion. A silk ligature was placed around the left renal vein at this site and was tied over the top of a probe. The latter was then withdrawn and the vein was allowed to expand. In shams, a suture was placed but it was not tied.

MAIN OUTCOME MEASURE(S)

To assess testicular microvascular density using CD34 immunostaining.

RESULT(S)

Microvascular density in the varicocele plus PDRN group was significantly higher than in other groups.

CONCLUSION(S)

PDRN could represent a novel therapeutic strategy for varicocele treatment in subfertile patients, improving the innate pathophysiologic mechanism of neoangiogenesis, through compensatory oxygen and metabolite supply to tubular and extratubular testicular compartments.

Activation of adenosine A2A receptors by polydeoxyribonucleotide increases vascular endothelial growth factor and protects against testicular damage induced by experimental varicocele in rats

In rat experimental varicocele, polydeoxyribonucleotide (PDRN) induces vascular endothelial growth factor (VEGF) production, thereby enhancing testicular function. This may point to a new therapeutic approach in human varicocele.