Seminal Plasma Leptin Research Articles

Evaluation of the Utility of Seminal Plasma Resistin and Leptin in Predicting Successful Surgical Sperm Retrieval in Men with Non-Obstructive Azoospermia.

The purpose of the current study was evaluation of the utility of seminal plasma (SP) resistin and leptin in predicting successful surgical sperm retrieval (SSR) in men with non-obstructive azoospermia (NOA). This prospective comparative study was conducted in the andrology clinic of a specialized fertility center. In total, 53 NOA men as candidates for either first time micro-testicular sperm extraction (micro-TESE) or repeat micro-TESE and 28 normozoospermic controls were included. ELISA was used for measurement of SP resistin and leptin levels in all participants. Significance level was defined as p<0.05. The current study demonstrated a significant positive correlation between estradiol (E2) level in serum and SP resistin (r=0.342, p=0.025). Also, there was a highly significant positive correlation between SP leptin and SP resistin (r=0.568, p= 0.001). Interestingly, SP leptin was the only variable that demonstrated a significant correlation with eventful micro-TESE outcome in men who underwent micro-TESE for the first time. Finally, ROC curve showed that SP leptin level of 4.05 ng/ml predicted successful SSR in men who underwent micro-TESE for the first time with a sensitivity of 73.3% and a specificity of 75% as 11 out of 27 (41%) cases showed eventful micro-TESE at or above this cut-off level [AUC of 0.747, 95% CI, lower bound of 0.555, and upper bound of 0.939, p=0.030]. SP leptin can be used as a non-invasive biomarker to predict successful SSR in NOA cases undergoing first time micro-TESE, while SP resistin failed to play the same role.

Leptin is upregulated in epididymitis and promotes apoptosis and IL-1β production in epididymal epithelial cells by activating the NLRP3 inflammasome

Epididymitis, one of the most common urological disease, is a significant cause of male infertility. Leptin is capable of modulating both reproduction and immune response. We analyzed the serum and seminal plasma levels of leptin in infertile patients with or without chronic epididymitis. Experimental epididymitis models were generated by administrating 200 μg Lipopolysaccharide (LPS) to Sprague-Dawley rats. The expression of leptin in epididymis were detected using qPCR, Western blots 6–72 h after injection, and using immunohistochemistry 72 h after injection. Besides, rat epididymal epithelial cells were isolated as an in vitro model and were treated with leptin (5–40 ng/ml, 6–48 h), LPS (1ug/ml, 6 h), and NLRP3 inflammasome inhibitor MCC950 (10 μM, 2 h). Cell Counting Kits-8 assay and Annexin V/PE assay were used to evaluate cell viability and apoptosis. Quantitive PCR and ELISA assay were used to detected inflammatory cytokines interleukin-1beta (IL-1β) production. Western Blots were used to detect molecular related to cell apoptosis, IL-1β maturation, and NLRP3 inflammasome. We found that patients with chronic epididymitis presented a significantly higher level of seminal plasma leptin and correlated declined sperm progressive motility. Leptin and leptin receptor expression in epididymis was significantly upregulated 24 h after LPS administration both in mRNA and protein level, and highly expressed in the epididymis epithelium 72 h after LPS administration. In epididymal epithelial cells, leptin reduced cell viability and promoted apoptosis in a concentration-dependent manner via cleavage of caspase-9, caspase-3, and PARP. Leptin enhanced the LPS-induced production of IL-1β, which was associated with increased IL-1β maturation and caspase-1 activation. Furthermore, NLRP3 inhibitor MCC950 attenuated the effects of leptin or co-treatment with LPS on NLRP3, ASC expression, IL-1β maturation, and caspase-1 activation, which indicated that leptin promotes IL-1β production via activating the NLRP3 inflammasome. These data suggested that leptin may act as a potential evaluation and treatment target for epididymitis and male subfertility.

Estimation of Leptin and Leptin Receptor Concentrations in Seminal Plasma of Primary Infertile Men

Background: There are many sources for Leptin secretion, and it is activated by binding with its receptor known as leptin receptor, that play a role in male infertility.Objective: To assess the levels of leptin and leptin receptors in seminal plasma among primary infertile men and its impact on semen parameters.Patients and Methods: A case control study of 75 primary infertile males and 40 healthy individuals who were enrolled in this study during March 2013 to May 2013. Estimation of age, body mass index (BMI), semen analysis, seminal plasma leptin, leptin receptor and testosterone hormone concentration were done for all study subjects.Results: Highly significant difference found in mean of semen parameters of infertile male compared with healthy controls. Mean concentration of seminal plasma leptin and leptin receptor of infertile men were significantly were elevated, while serum testosterone concentration significantly decreased compared with healthy control.Conclusion: There is emerging evidence that the leptin concentration negatively impacts fertility through its correlation with age, BMI, testosterone hormone and semen parameters.

Quantification of leptin in seminal plasma of buffalo bulls and its correlation with antioxidant status, conventional and computer-assisted sperm analysis (CASA) semen variables

The present study is the first to quantify leptin in seminal plasma of buffalo and investigate its relationship with seminal attributes. Ten ejaculates each from 10 Murrah buffalo bulls were collected. Semen quality variables such as semen volume, sperm concentration, sperm abnormalities, membrane integrity, antioxidant enzyme activities (superoxide dismutase, catalase and total antioxidant capacity), malondialdehyde (MDA) concentration, as well as sperm kinetics and motility variables were evaluated. The leptin concentration in serum and seminal plasma were estimated by the ELISA method. Bulls were classified in two groups on the basis of sperm concentration with Group I having >800 million sperm/mL and Group II <500 million sperm/mL. Greater (P<0.05) mean sperm abnormalities, seminal leptin concentrations and MDA concentrations were recorded in Group II than Group I. The seminal leptin was positively correlated with sperm abnormalities and MDA concentration while being negatively correlated with sperm concentration, but there was no correlation with sperm kinetic and motility variables, sperm membrane integrity and seminal plasma antioxidant enzyme activity. Thus, the data suggest that seminal leptin has a role in spermatogenesis and can be used as a marker for spermatogenesis to predict the capacity of buffalo bulls for semen production.

Seminal plasma leptin and spermatozoon apoptosis in patients with varicocele and leucocytospermia.

Excessive apoptotic spermatozoon death is associated with male infertility. Leptin regulates apoptosis in several cell types. We prospectively investigated if seminal plasma leptin mediates spermatozoon apoptosis in 74 varicocele (VC) patients and 70 leucocytospermia patients. Spermatozoa from 40 normospermic men were used as controls. Routine semen analysis, spermatozoon apoptosis rate, seminal plasma leptin, reactive oxygen species (ROS) and tumour necrosis factor-alpha (TNF-α) levels were measured. In VC and leucocytospermia patients, seminal plasma leptin levels and spermatozoon apoptosis rates were significantly higher compared with controls. In the VC group, seminal plasma ROS levels were significantly higher compared with controls; there were no significant differences in TNF-α levels. In the leucocytospermia group, both ROS and TNF-α levels were significantly higher compared with controls. In both the VC and leucocytospermia groups, there was a significant positive correlation between the spermatozoon apoptosis rate and leptin levels and ROS and leptin levels. There was a significant correlation between leptin and TNF-α levels in the leucocytospermia group. Seminal plasma leptin levels correlate significantly with spermatozoon apoptosis rate, and leptin may be a spermatozoon pro-apoptotic factors. The generation of ROS is a possible mechanism. Leptin may induce apoptosis via TNF-α in leucocytospermia patients.

Expression and Role of Leptin under Hypoxic Conditions in Human Testis: Organotypic In Vitro Culture Experiment and Clinical Study on Patients with Varicocele

We investigated the expression and the exact role of leptin under hypoxic conditions in the human testis. Five testes from patients treated with orchiectomy for prostate cancer were used to construct an in vitro hypoxic culture system for human testicular tissue. Immunohistochemistry was performed to analyze leptin protein expression. Leptin, leptin receptor and HIF-1α mRNA were examined by quantitative reverse transcriptase-polymerase chain reaction. Serum and seminal plasma leptin, gonadal hormones and semen parameters were evaluated in 10 healthy donors and 42 infertile patients with varicocele before and after surgery. The viability of in vitro cultured testicular tissue was well maintained within 48 hours based on the results of morphological analysis, cell number and cell specific mRNAs. Immunohistochemistry demonstrated that leptin was mainly expressed in seminiferous tubules. Interestingly the optical density of leptin, leptin mRNA and HIF-1α mRNA was significantly increased under hypoxia. Leptin mRNA and HIF-1α mRNA correlated positively (Rs = 0.843, p <0.01). In the clinical study the concentration of seminal plasma leptin before varicocelectomy was markedly higher in patients (mean ± SD 3.01 ± 1.23 ng/l, p <0.01). It was highest in the grade 3 group (mean 3.95 ± 1.37 ng/l, p <0.01) and significantly decreased in the 6-month postoperative group (2.35 ± 0.78, p <0.05). Furthermore, negative correlations were observed between seminal plasma leptin and the sperm concentration (Rs = -0.187, p <0.05), and progressive motility (Rs = -0.234, p <0.05). Leptin expression was induced under hypoxia in the human testis, probably via the HIF-1α related response pathway. Seminal plasma leptin closely correlated with varicocele related spermatogenesis dysfunction. It might effectively reflect the testicular hypoxic environment.

MP-11.01: The Serum and Seminal Plasma Leptin Levels in Athenospermia

To analyze the differences of serum and seminal plasma leptin levels between those with athenospermia and control, and to explore the relationships between leptin and sperm motility.

Leptin and varicocele‐related spermatogenesis dysfunction: animal experiment and clinical study

The objective of this study was to explore the relationships between varicocele-related spermatogenesis dysfunction and the expression of leptin and leptin receptors. In rats with experimental varicocele, the function of spermatogenesis, the expression of leptin and leptin receptors in testes were analysed; and in patients with varicocele-related male infertility, serum and seminal plasma levels of leptin, gonadal hormones and semen parameters were evaluated. In the testes of rats, leptin was expressed in seminiferous tubules and intersitium, leptin receptor was predominantly expressed in interstitium. The expression of leptin and its receptor in the testis of rats was not related to the weight of rat, but was inversely related to the weight of testis (r = -0.408, p = 0.009 and r = -0.433, p = 0.005, respectively), the Johnsen scores (r = -0.916, p = 0.000 and r = -0.863, p = 0.000, respectively), the seminiferous tubules diameter (r = -0.853, p = 0.000 and r = -0.870, p = 0.000, respectively) and the thickness of seminiferous epithelium (r = -0.929, p = 0.000 and r = -0.948, p = 0.000, respectively). In varicocele patients (N = 40), the sperm concentration and motility were significantly lower (p = 0.000) than those in the control group (N = 25), and the leptin level in seminal plasma was significantly higher (p = 0.000) than that in the control group. The leptin in serum and seminal plasma was positively related (r = 0.223, p = 0.002). The seminal plasma leptin level was inversely related to sperm concentration (r = -0.632, p = 0.000) and motility (r = -0.635, p = 0.000). There was no significant relation between serum leptin and seminal parameters and between leptin and gonadal hormone values. The dysfunction of spermatogenesis in varicocele-related infertile male is associated with increase in leptin and leptin receptors. Leptin may have local effects on the function of testis and spermatogenesis.

RNA extraction and Leptin receptor mRNA detection in bull ejaculated spermatozoa

Leptin, known as a potential satiety factor, plays an important role in both metabolism and reproduction. The presence of leptin in human seminal plasma and human spermatozoa has been shown; recently, leptin receptors (Ob-R) have been localized in human spermatozoa, thus suggesting a possible action of this hormone even on these cells. Our aim was to detect leptin receptor mRNA in bull ejaculated spermatozoa by reverse transcriptase-polymerase chain reaction (RT-PCR). Total RNA was isolated from bull ejaculated spermatozoa and purified by different methods. Our results have revealed that sodium dodecyl sulphate (SDS) and SDS/citric acid extraction methods are superior to guanidinium isothiocyanate in terms of yield and reproducibility of RNA recovery. The mRNA for Ob-Rb was detected in all samples examined. We conclude that Ob-R mRNA is present in bull spermatozoa where seminal plasma leptin can exert its effects.

Leptin receptor in boar spermatozoa

Leptin is active in both metabolism and reproduction. In fact, it seems to exert an inhibitory action on gonadal functions by reducing testosterone production. The presence of leptin in human and boar seminal plasma and in human spermatozoa has been demonstrated; recently, leptin receptors (Ob-R) have been localized in human spermatozoa, thus suggesting a possible action of this hormone even on these cells. Our aim was to verify whether leptin receptor [the long form (Ob-Rb)] is present in boar spermatozoa. Immunofluorescence and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques were employed. RNA was extracted from boar spermatozoa and a specific band (382 bp) for Ob-Rb was detected after RT-PCR. Ob-Rb was detected on acrosome, subequatorial area and either on the midpiece or on the whole tail. These localizations were maintained even in semen washed twice to eliminate seminal plasma. We conclude that Ob-R is present in boar spermatozoa where seminal plasma leptin can exert its effects.

Leptin exists in tubuli seminiferi and in seminal plasma.

Leptin is a 167-amino acid protein that stimulates gonadotrophin-releasing hormone secretion and exerts indirect effects on the gonads via neuropeptide Y, NPY. Recent research has suggested that leptin may also have an effect on testosterone secretion. To investigate the role of leptin in reproduction, leptin in testicular tissue and seminal plasma was examined in relation to leptin in serum, semen sample qualities and vasectomy. Seminal plasma and serum of 64 infertility patients, and 15 individuals after vasectomy, were assayed for leptin using a competitive 'in house' radioimmunoassay. The concentration of leptin in seminal plasma was significantly lower in the 'normal' semen sample group than in the 'pathological' group (Mean +/- SEM; 1.45 +/- 0.18 vs. 3.19 +/- 0.57 ng ml-1; P < 0.05), and showed a significantly negative correlation with percentage of motile spermatozoa (r = -0.46; P = 0.0005) and with the velocity straight line, VSL, (r = -0.30; P = 0.029). In contrast, leptin concentration in serum did not show any relationship with the spermiogram parameters. In testicular tissue, leptin was preferentially found within the tubuli seminiferi using anti-leptin polyclonal antibody, Ob A-20 Sc 842. The amount of leptin per ejaculate did not significantly change after vasectomy, and was not correlated to fructose, zinc or neutral alpha glucosidase in seminal plasma (P > 0.05). These results suggest that the amount of leptin in the genital tract, including the tubuli seminiferi, may influence the mechanisms involved in the motility development of spermatozoa.