Angiotensin II Dependent Testicular Fibrosis and Effects on Spermatogenesis After Vasectomy in the Rat

Liraglutide ameliorates diabetic-induced testicular dysfunction in male rats: role of GLP-1/Kiss1/GnRH and TGF-β/Smad signaling pathways

Introduction: Glucagon-like peptide -1 (GLP-1) is released by intestinal cells to stimulate glucose-dependent insulin release from the pancreas. GLP-1 has been linked to ameliorating obesity and/or diabetic complications as well as controlling reproductive function. Liraglutide is a GLP-1 receptor agonist (GLP-1RA) with 97% homology with GLP-1. The main objective of this study was to investigate the ameliorative role of liraglutide in diabetic-induced reproductive dysfunction in male rats. Methods: Rats were randomly allocated into 3 groups; a control group, a diabetic group, and a liraglutide-treated diabetic group. Results: In the diabetic group, a significant increase in BMI, FBG, HbA1c, HOMA-IR, TC, TAG, LDL, IL6, TNFα, and MDA, as well as decreased serum insulin, HDL, GSH, total testosterone, LH, and FSH, were shown compared to the control group. Furthermore, A significant downregulation in relative hypothalamic gene expression of GLP-1R, PPAR-α, PGC-1α, kiss, kiss1R, leptin, leptin R, GnRH GLP-1R, testicular PGC-1α, PPARα, kiss1, kiss1R, STAR, CYP17A1, HSD17B3, CYP19A, CYP11A1, and Smad7, as well as upregulation in hypothalamic GnIH and testicular TGF- β and Smad2 expression, were noticed compared to the control group. Liraglutide treatment significantly improved such functional and structural reproductive disturbance in diabetic rats. Conclusion: GLP-1RAs ameliorated the deleterious effects of diabetes on reproductive function by targeting GLP-1/leptin/kiss1/GnRH, steroidogenesis, and TGF- β/Smad pathways.

Vitamin D3 supplementation improves testicular function in diabetic rats through peroxisome proliferator-activated receptor-γ/transforming growth factor-beta 1/nuclear factor-kappa B

AIMS/INTRODUCTION

Vitamin D3 deficiency can lead to male hypogonadism in diabetes mellitus, but the target organs and the mechanism driving the disorder are unclear. This experiment was designed to study the relationship between vitamin D3 deficiency and hypogonadism in diabetes mellitus.

MATERIALS AND METHODS

Rats with streptozotocin-induced diabetes were randomly divided into four groups and treated with different doses of vitamin D3 : blank (no vitamin D3 ), low (0.025 μg/kg/day), high (0.1 μg/kg/day), high (0.1 μg/kg/day) and with bisphenol A diglycidyl ether (peroxisome proliferator-activated receptor gamma inhibitor 30 mg/kg/day). They were compared with wild-type rats.

RESULTS

After 12 weeks, the vitamin D3 supplements had partially restored testicular pathological changes, as shown by reduced testicular fibrosis related to downregulation transforming growth factor beta 1 and apoptosis related to downregulation of nuclear factor kappa B, but not the pituitary gland. The expression of peroxisome proliferator-activated receptor gamma, which can inhibit transforming growth factor beta 1 and nuclear factor kappa B, was significantly increased after treatment with vitamin D3 .

CONCLUSIONS

These results suggest that treatment with vitamin D3 can improve testicular function in diabetic rats through the peroxisome proliferator-activated receptor gamma/transforming growth factor beta 1/nuclear factor kappa B signaling pathway.

Candesartan Mediated Amelioration of Cisplatin-Induced Testicular Damage Is Associated with Alterations in Expression Patterns of Nephrin and Podocin

Nephrin and podocin are known to be closely related to the pharmacological effects of angiotensin-II receptor blocker (ARB). The objectives of this study were to investigate the role of nephrin and podocin using cisplatin-induced testicular damage and to evaluate the effect of ARB. At first, we evaluated the effects of cisplatin either alone or in combination with ARB candesartan on changes in expression patterns of nephrin and podocin in the rat testes. We then conducted in vitro studies to investigate the effects of angiotensin using cultured Sertoli cells, line TM4. As a result, the expression of nephrin and podocin was shown to localize around the basal membrane of seminiferous tubules. Treatment with cisplatin resulted in a marked decrease in the expression of nephrin and podocin and induced a shift of both proteins from linear to granular expression patterns, accompanying the increased apoptotic index in the testes; these changes were partially restored by the additional administration of candesartan. In vitro studies with TM4 revealed the angiotensin-II mediated expression changes of nephrin and podocin. These findings suggest that candesartan can prevent cisplatin-induced testicular damage by regulating expression patterns of the nephrin-podocin complex in the testes.

The prevalence of Peyronie's disease in Japan: a study in men undergoing maintenance hemodialysis and routine health checks

INTRODUCTION

The incidence of Peyronie's disease (PD) in the general population is believed to be as high as 20%. However, most of the data concerning the prevalence of PD have been obtained from Caucasian populations.

AIM

The aim of this study was to examine the prevalence of PD in Asia and among men undergoing hemodialysis and discuss the pathophysiology of PD.

METHODS

A total of 1,090 men who received a routine health check at our hospital (control group) as well as 130 male patients undergoing maintenance hemodialysis were enrolled. The diagnosis of PD was based on a palpable penile plaque.

MAIN OUTCOME MEASURES

Hemodialysis patients were asked about their sexual activity and completed the International Index of Erectile Function-5 questionnaires. The differences between patients' and hemodialysis-associated factors, comorbidities, and medications were statistically assessed for patients with and without PD.

RESULTS

The prevalence of PD was significantly increased among hemodialysis patients (12 patients: 9.2%) relative the control group (six men: 0.6%) (P<0.0001, odds ratio: 18.4). In both groups, the plaques were primarily allocated dorsally. In the hemodialysis patients with PD, the frequency of masturbation (P<0.05) and the incidence of moderate or severe erectile dysfunction (P<0.01) were significantly higher than those among hemodialysis patients without PD. In comparison with patients without PD, the number of acetate dialysate users was significantly higher among patients with PD (P<0.05), and none of the PD patients used angiotensin-related antihypertensive drugs (P<0.05).

CONCLUSIONS

The prevalence of PD in healthy Japanese men is low (0.6%), which suggests the existence of racial differences in the prevalence of PD. Moreover, these results indicate that hemodialysis increases the incidence of PD. The differences in the characteristics between male hemodialysis patients with and without PD provide new insights into the pathophysiology and therapeutic window of PD.

Effects of 4-Hydroxy-2-Nonenal, a Marker of Oxidative Stress, on Spermatogenesis and Expression of p53 Protein in Male Infertility

PURPOSE

Oxidative stress is involved in male infertility. However, little is known about how it impairs spermatogenesis. We investigated the presence of oxidative stress in human testes by studying the generation of 4-hydroxy-2-nonenal modified proteins and expressions of proliferating cell nuclear antigen and p53.

MATERIALS AND METHODS

A total of 47 testicular biopsies from patients with varicocele, obstructive azoospermia and idiopathic infertility were included. Localization and generation of 4-hydroxy-2-nonenal modified proteins were determined by immunohistochemistry and Western blotting. The expressions of proliferating cell nuclear antigen and p53 were assessed by Western blotting. The interaction between 4-hydroxy-2-nonenal modified proteins and p53 was examined by immunoprecipitation. Data were compared to clinicopathological parameters.

RESULTS

4-Hydroxy-2-nonenal modified proteins were strongly positive in spermatogonia, primary spermatocytes and Sertoli's cells, and generation was inversely correlated with expression of proliferating cell nuclear antigen. The expression of p53 was increased in testes with varicocele (p <0.01) and obstructive azoospermia (p <0.05), and there was a positive or inverse correlation with 4-hydroxy-2-nonenal modified proteins and proliferating cell nuclear antigen. Immunoprecipitated p53 was detected by anti-4-hydroxy-2-nonenal modified protein antibody.

CONCLUSIONS

4-Hydroxy-2-nonenal impairs the proliferation of germ cells through the up-regulation of p53 protein, especially in testes with varicocele. Modification by 4-hydroxy-2-nonenal might alter normal function and stabilization of p53 protein.

Increased vaginal oxidative stress, apoptosis, and inducible nitric oxide synthase in a diabetic rat model: implications for vaginal fibrosis

OBJECTIVE

To determine whether vaginal fibrosis occurs in diabetic animals and is associated with oxidative stress and cell death and with the expression of inducible nitric oxide synthase (iNOS), as a putative antifibrotic mechanism.

DESIGN

Research experimental project.

SETTING

University research laboratory.

ANIMAL(S)

Female Wistar rats.

INTERVENTION(S)

Female rats were injected with streptozotocin or saline and killed at 3 months. The vaginas were excised and processed for paraffin-embedded sections (n = 6 per group) or were frozen for biochemical and molecular biology procedures.

MAIN OUTCOME MEASURE(S)

Immunohistochemistry and quantitative image analysis were applied to tissue sections to measure alpha-smooth muscle actin, transforming growth factor beta1, plasminogen activator inhibitor, NOS isoforms, Cu/Zn superoxide dismutase, apoptotic index, and nitrotyrosine. Xanthine dehydrogenase, reactive oxygen species (ROS), and hydroxyproline were measured in fresh vaginal tissue (n = 5 per group). Reactive oxygen species also were determined in blood.

RESULT(S)

Diabetes was associated with vaginal fibrosis, as evidenced by increased collagen, transforming growth factor beta1, plasminogen activator inhibitor, and apoptosis, and by decreased alpha-smooth muscle actin. The increment of ROS and the reduction of superoxide dismutase indicated oxidative stress in diabetic tissue, accompanied by iNOS induction and increased nitric oxide-ROS reaction.

CONCLUSION(S)

Diabetes in the rat causes oxidative stress and fibrosis in the vagina, which may be compensated partially by iNOS induction to reduce ROS.

Increased expression of Leydig cell haem oxygenase-1 preserves spermatogenesis in varicocele

BACKGROUND

Oxidative stress is involved in the pathogenesis of testicular disorders. Haem oxygenase-1 (HO-1) plays an important cytoprotective role against oxidative stress. We investigated the presence of oxidative stress, represented by generation of 4-hydroxy-2-nonenal (4-HNE)-modified proteins, and expression of HO-1 in varicocele testes of human.

METHODS

Thirty testicular biopsies from patients with left varicocele and 10 from patients with normal spermatogenesis were included. Generation of 4-HNE-modified proteins was examined as a marker of oxidative stress. Expression of HO-1 was assessed by western blotting and immunohistochemistry. The expression was compared with clinico-pathological parameters.

RESULTS

Increased generation of 4-HNE-modified proteins was observed in varicocele testes. HO-1 expression was significantly correlated with varicocele grade (P < 0.01 in grade 2 and 3 compared to control) and expression of 4-HNE-modified proteins (r = 0.508, P < 0.01). The immunoreactivity was increased in Leydig cells in varicocele testes. There were significant correlations between age, total motile sperm count, Johnsen's mean score and HO-1:4-HNE-modified protein ratio (r = 0.206, 0.405 and 0.408, P = 0.027, 0.027 and 0.025 respectively).

CONCLUSIONS

In testes with varicocele, there are increases in 4-HNE-modified proteins, suggesting that oxidative stress is present. Increased HO-1 expression, mainly in Leydig cells, is considered to protect the cells against oxidative stresses in varicocele testes.