Leptin and prolactin reduce cryodamage in normozoospermic human semen samples during cryopreservation / La leptina y la prolactina reducen el criodaño en muestras de semen humano normozoospérmico durante la criopreservación

Objectives: Cryopreservation has destructive effects on the function and structure of spermatozoa. It is known that leptin and prolactin play an active role in decreasing the rates of reactive oxygen species and DNA fragmentation, as well as enhancing sperm motility. Hence, this experiment aimed to investigate the effects of leptin and prolactin as pro-survival factors on the normozoospermic human semen samples during cryopreservation. Material and methods: Semen samples were collected from 15 healthy, fertile men ranging from 25 to 40 years. Cryopreservation of the samples was performed in liquid nitrogen over a period of two weeks, using five varying concentrations of leptin/prolactin, 0, 10, 100, 500, and 1000ng/ml respectively. Sperm motility, total caspase activity, and mitochondrial and cytosolic ROS were measured by flowcytometry, TUNEL, and other appropriate tests after thawing of the samples. Results: Both hormones were observed to have positive effects on the motility of the samples post-cryopreservation, the highest improvement being in the 100ng/ml concentration leptin and prolactin in comparison to the control group (P=0.01 and P=0.041, respectively). A significant reduction of mitochondrial ROS was also observed in 100 and 1000ng/ml of leptin (P=0.042), and there was a considerable decrease in the cytosolic ROS in the 100ng/ml of prolactin in comparison to the control group (P=0.048). Total caspase activity was also highly reduced in the 100, 500, and 1000ng/ml of leptin compared to the control group (P=0.039). Interestingly, both hormones also significantly decreased DNA fragmentation in 1000ng/ml compared to the control group (P=0.042). (AU)

Objetivos: La criopreservación tiene efectos destructivos sobre la función y estructura de los espermatozoides. Se sabe que la leptina y la prolactina desempeñan un papel activo en la disminución de las tasas de especies reactivas de oxígeno (ROS) y la fragmentación del ADN, así como en la mejora de la motilidad de los espermatozoides. Por lo tanto, este experimento tuvo como objetivo investigar los efectos de la leptina y la prolactina como factores de supervivencia en las muestras de semen humano normozoospérmico durante la criopreservación. Material y métodos: Se recolectaron muestras de semen de 15 hombres sanos y fértiles de entre 25 y 40 años. La crioconservación de las muestras se realizó en nitrógeno líquido durante un período de 2 semanas, utilizando 5 concentraciones variables de leptina/prolactina: 0, 10, 100, 500 y 1000ng/ml respectivamente. La motilidad de los espermatozoides, la actividad de caspasa total y las ROS mitocondriales y citosólicas se midieron mediante citometría de flujo, TUNEL y otras pruebas apropiadas después de descongelar las muestras. Resultados: Se observó que ambas hormonas tienen efectos positivos sobre la motilidad de las muestras después de la crioconservación, la mayor mejora se encuentra en la concentración de leptina y prolactina de 100ng/ml en comparación con el grupo de control (p=0,01 y p=0,041, respectivamente). También se observó una reducción significativa de las ROS mitocondriales en 100 y 1000ng/ml de leptina (p=0,042), y hubo una disminución considerable en las ROS citosólicas en los 100ng/ml de prolactina en comparación con el grupo de control (p=0,048). La actividad de la caspasa total también se redujo considerablemente en los 100, 500 y 1000ng/ml de leptina en comparación con el grupo de control (p=0,039). Curiosamente, ambas hormonas también redujeron significativamente la fragmentación del ADN en 1000ng/ml en comparación con el grupo de control (p=0,042). (AU)

Photobiomodulation therapy reverses spermatogenesis arrest in hyperthermia-induced azoospermia mouse model.

Testicular heat stress leads to impairment of spermatogenesis in mammals. Involved mechanism in this vulnerability to heat-induced injury remains unclear, and research is being conducted to find an approach to reverse spermatogenesis arrest caused by hyperthermia. Recently, different studies have utilized photobiomodulation therapy (PBMT) therapy for the improvement of sperm criteria and fertility. This study aimed at evaluating the effect of PBMT on the improvement of spermatogenesis in mouse models of hyperthermia-induced azoospermia. A total of 32 male NMRI mice were equally divided into four groups consisting of control, hyperthermia, hyperthermia + Laser 0.03 J/cm2, and hyperthermia + Laser 0.2 J/cm2. To induce scrotal hyperthermia, mice were anesthetized and placed in a hot water bath at 43 °C for 20 min for 5 weeks. Then, PBMT was operated for 21 days using 0.03 J/cm2 and 0.2 J/cm2 laser energy densities in the Laser 0.03 and Laser 0.2 groups, respectively. Results revealed that PBMT with lower intensity (0.03 J/cm2) increased succinate dehydrogenase (SDH) activity and glutathione (GSH)/oxidized glutathione (GSSG) ratio in hyperthermia-induced azoospermia mice. At the same time, low-level PBMT reduced reactive oxygen species (ROS), mitochondrial membrane potential, and lipid peroxidation levels in the azoospermia model. These alterations accompanied the restoration of spermatogenesis manifested by the elevated number of testicular cells, increased volume and length of seminiferous tubules, and production of mature spermatozoa. After conducting experiments and analyzing the results, it has been revealed that the use of PBMT at a dosage of 0.03 J/cm2 has shown remarkable healing effects in the heat-induced azoospermia mouse model.

Insulin Ameliorates Folliculogenesis in An Experimental Model of PCOS Mice.

BACKGROUND: Insulin is an essential factor that controls female reproductive system. Insulin signaling via Foxo1 and Akt1 can improve steroidogenesis, cell proliferation, and protein synthesis. We aimed to determine the effect of insulin on possible changes in gene expression, hormonal status, and histological aspects of the ovary following the induction of the animal model of polycystic ovary syndrome (PCOS). MATERIALS AND METHODS: In this experimental study, 24 adult female NMRI mice weighing 25-30 g were randomly placed in three groups: control, PCOS (60 mg/kg dehydroepiandrosterone (DHEA) for 20 days, and PCOS+insulin (60 mg/kg DHEA for 20 days+100 µL insulin diluted in water twice a week for 30 consecutive days). Blood specimens were obtained from the heart and the serum levels of testosterone, progesterone, and estradiol were measured. Right, and left ovaries were removed for real-time polymerase chain reaction (PCR) and stereological study. RESULTS: DHEA injection significantly amplified the concentration of testosterone, progesterone, and estradiol. While insulin treatment amended the level of reproductive hormones. DHEA injection significantly reduced the expression levels of Irs1-4, Pdk1, Pi3k, and Akt1-3 and raised the expression level of Caspase-3. However, insulin administration amplified expression levels of Irs1-4, Pdk1, Pi3k, and Akt1-3, and reduced Caspase-3. The total volume of ovarian tissue in mice receiving DHEA significantly declined compared to the control group. Besides, a substantial decrease was detected in the number of ovarian antral, Graafian, and primordial follicles and also in the total number of corpus luteum following DHEA administration. Comparison of structural alterations in ovarian tissue between the PCOS+insulin and the PCOS groups displayed that insulin administration improved the total number of Graafian, primordial, and antral follicles and also corpus luteum. CONCLUSION: In general, short-term insulin treatment showed improvement in hormonal balance, folliculogenesis, and insulin resistance in the ovaries of the PCOS mice model.

Leptin and prolactin reduce cryodamage in normozoospermic human semen samples during cryopreservation.

OBJECTIVES: Cryopreservation has destructive effects on the function and structure of spermatozoa. It is known that leptin and prolactin play an active role in decreasing the rates of reactive oxygen species and DNA fragmentation, as well as enhancing sperm motility. Hence, this experiment aimed to investigate the effects of leptin and prolactin as pro-survival factors on the normozoospermic human semen samples during cryopreservation. MATERIAL AND METHODS: Semen samples were collected from 15 healthy, fertile men ranging from 25 to 40 years. Cryopreservation of the samples was performed in liquid nitrogen over a period of two weeks, using five varying concentrations of leptin/prolactin, 0, 10, 100, 500, and 1000ng/ml respectively. Sperm motility, total caspase activity, and mitochondrial and cytosolic ROS were measured by flowcytometry, TUNEL, and other appropriate tests after thawing of the samples. RESULTS: Both hormones were observed to have positive effects on the motility of the samples post-cryopreservation, the highest improvement being in the 100ng/ml concentration leptin and prolactin in comparison to the control group (P=0.01 and P=0.041, respectively). A significant reduction of mitochondrial ROS was also observed in 100 and 1000ng/ml of leptin (P=0.042), and there was a considerable decrease in the cytosolic ROS in the 100ng/ml of prolactin in comparison to the control group (P=0.048). Total caspase activity was also highly reduced in the 100, 500, and 1000ng/ml of leptin compared to the control group (P=0.039). Interestingly, both hormones also significantly decreased DNA fragmentation in 1000ng/ml compared to the control group (P=0.042). CONCLUSION: It can be concluded that leptin and prolactin act as protective agents against cryodamage to spermatozoa during cryopreservation.

COVID-19 disrupts the blood-testis barrier through the induction of inflammatory cytokines and disruption of junctional proteins.

OBJECTIVE: Junctional proteins are the most important component of the blood-testis barrier and maintaining the integrity of this barrier is essential for spermatogenesis and male fertility. The present study elucidated the effect of SARS-CoV-2 infection on the blood-testis barrier (BTB) in patients who died from severe acute respiratory syndrome coronavirus 2 (COVID-19) complications. METHODS: In this study, lung and testis tissue was collected from autopsies of COVID-19 positive (n = 10) and negative men (n = 10) and was taken for stereology, immunocytochemistry, and RNA extraction. RESULTS: Evaluation of the lung tissue showed that the SARS-CoV-2 infection caused extensive damage to the lung tissue and also increases inflammation in testicular tissue and destruction of the testicular blood barrier. Autopsied testicular specimens of COVID-19 showed that COVID-19 infection significantly changes the spatial arrangement of testicular cells and notably decreased the number of Sertoli cells. Moreover, the immunohistochemistry results showed a significant reduction in the protein expression of occluding, claudin-11, and connexin-43 in the COVID-19 group. In addition, we also observed a remarkable enhancement in protein expression of CD68 in the testes of the COVID-19 group in comparison with the control group. Furthermore, the result showed that the expression of TNF-α, IL1ß, and IL6 was significantly increased in COVID-19 cases as well as the expression of occludin, claudin-11, and connexin-43 was decreased in COVID-19 cases. CONCLUSIONS: Overall, the present study demonstrated that SARS-CoV-2 could induce the up-regulation of the pro-inflammatory cytokine and down-regulation of junctional proteins of the BTB, which can disrupt BTB and ultimately impair spermatogenesis.

Chronic scrotal hyperthermia induces azoospermia and severe damage to testicular tissue in mice.

Scrotal hyperthermia leads to altered spermatogenesis due to heat-related oxidative stress. One of the main causes of infertility in men is oxidative stress, which refers to an imbalance in the levels of reactive oxygen species (ROS) and antioxidants. Therefore, this study aimed to evaluate the effects of chronic scrotal hyperthermia on testicular tissue structure, sperm parameters, and oxidative stress in adult mice. Thirty adult NMRI male mice were divided into three groups: Control (n = 10), Sham (n = 10), and Hyperthermia (n = 10). At the end of the study animals were sacrificed for evaluations of biochemical, cellular and histological analysis. The Hyperthermia group revealed a significant reduction in sperm count and weight of testis when compared to the control and sham groups. Also, succinate dehydrogenase (SDH) activity, ROS, ATP production, glutathione disulfide (GSH), tiols metabolism and stereological parameters in the hyperthermia group showed a significant reduction compared to the control and sham groups. Our results also revealed that scrotal hyperthermia significantly increases ROS production, mitochondrial membrane permeability (MMP), malondialdehyde (MDA), oxidized glutathione (GSSG) and apoptotic cells in testicular tissue in the hyperthermia groups in comparison with the control and sham groups. Overall, our result indicated that chronic scrotal hyperthermia causes complete spermatogenic arrest, probably mainly throughout the induction of oxidative stress.

Expression of RXFP2 receptor on human spermatozoa and the anti-apoptotic and antioxidant effects of insulin-like factor 3.

Insulin-like factor 3 (INSL3) has an important role in the human reproductive system; however, its detailed function is still mysterious. We aimed to investigate the possibility of expression of RXFP2 receptor on human spermatozoa and to determine the anti-apoptotic and antioxidant mechanism derived the binding of INSL3 and RXFP2. In this experimental study, the expression/location of the RXFP2 receptor was determined on the spermatozoa of fertile and infertile men. Twenty samples from 20 fertile men were collected and divided into 6 parts (control group, and five groups treated with INSL3 10, 100, 250, 500, 1,000 ng/ml). DNA damage, active caspase, reactive oxygen species (ROS) and sperm parameters were evaluated by TUNEL, flow cytometry, optical microscope and computer-assisted sperm analysis. The expression of RXFP2 was confirmed by Western blot. Immunocytochemistry illustrated that this receptor is expressed in the posterior half of the spermatozoa's head. The INSL3 at concentrations of 500 and 1,000 ng/ml reduced the active caspase and mitochondrial ROS, and also reduced DNA fragmentation at 1,000 ng/ml. Besides, INSL3 500 and 1,000 ng/ml significantly increased the sperm motility. This study confirmed the presence of RXFP2 receptor in fertile and infertile men's spermatozoa, indicating the highly dose-dependent efficacy of the INSL3, which may have promising impacts on the in-vitro fertilisation outcomes.

Hyperthermia versus busulfan: Finding the effective method in animal model of azoospermia induction.

Animal models of azoospermia are very applicable when evaluating new treatment methods for research purposes. The present study aimed to compare azoospermia induction in mice using busulfan or hyperthermia. To do this, about 36 adult male mice (28-30 g) were included into three experimental groups randomly (n = 12): control, busulfan (injected by a single dose of 40 mg/kg busulfan intraperitoneally) and hyperthermia (exposure to a temperature of 43°C every other day for 5 weeks). Animals were preserved for 35 and 70 days following interventions and then were sacrificed for further evaluations. After 35 days, busulfan and hyperthermia groups revealed a significant decrease in the sperm count and weight of testis compared to the control group (p < .0001). In addition, after 70 days, sperm count and weight of testis in group busulfan showed a significant increase compared to group hyperthermia (p < .01). No significant difference was observed regarding the mortality of mice between busulfan and hyperthermia groups. In group busulfan, degenerative changes in the germinal epithelium were detected in some tubules, although in group hyperthermia, degenerative changes and complete depletion of all tubules were observed. Continuous hyperthermia is a more effective method in the induction of as animal model of azoospermia compared to the busulfan.

Impaired spermatogenesis associated with changes in spatial arrangement of Sertoli and spermatogonial cells following induced diabetes.

The current study was conducted to assess the relationship between testicular cells in spermatogenesis, through which the production of healthy and mature sperm is essential. However, it seems necessary to obtain more information about the three-dimensional pattern of the testis cells arrangement, which is directly related to the function of the testis after induction of diabetes. Twelve adult mice (28-30 g) were assigned into two experimental groups: (1) control and (2) diabetic (40 mg/kg STZ). The epididymal sperm collected from the tail of the epididymis and testes samples were taken for stereology, immunocytochemistry and RNA extraction. Our data showed that diabetes could notably decrease the number of testicular cells, together with a reduction of total sperm count. In addition, the results from the second-order stereology indicated the significant changes in the spatial arrangement of Sertoli cells and spermatogonial cells in the diabetic groups, in comparison with the control (P < .05). Moreover, the immunohistochemistry results showed a significant reduction in Sex-determining Region Y (SRY) box 9 gene (SOX9), vimentin, occludin, and connexin-43 positive cells in the diabetic groups compared with the control (P < .05). Furthermore, our data showed that the expression of steroidogenic acute regulatory protein steroidogenic acute regulatory protein (StAR) and peripheral benzodiazepine receptor peripheral benzodiazepine receptor (PBR) was significantly reduced in the diabetic groups, in comparison with the control (P < .05). These findings suggest that structural and functional changes of testis cells after induction of diabetes cause the alterations in the spatial arrangement of Sertoli and spermatogonial cells, ultimately influencing the normal spermatogenesis in mice.

Effects of Sertoli Cell Transplantation on Spermatogenesis in Azoospermic Mice.

BACKGROUND/AIMS: The aim of this study was to evaluate the potential and significant applications of Sertoli cells (SCs) transplantation, and to explore the effect of transplantation on spermatogenesis process, in azospermic mice. METHODS: In this study, we utilized 18 adult mice (28‒30 g), divided into four experimental groups: (1) control, (2) vehicle (DMSO 2%) (10 µl) (3) busulfan and (4) busulfan+ SCs (1×104 cells/µL). SCs were isolated from the testis of 4-week-old mouse and after using anesthetics, 10 µl of SCs suspension (1×104 cells/µL) was injected over 3-5 min, into each testis and subsequently, sperm samples were collected from the tail of the epididymis. Afterward, the animals were euthanized and testis samples were taken for histopathology experiments, and RNA extraction, in order to examine the expression of c-kit, STRA8 and PCNA genes. RESULTS: Our data showed that SCs transplantation could notably increase the total sperm count and the number of testicular cells, such as spermatogonia, primary spermatocyte, round spermatid, SCs and Leydig cells, compared to the control, DMSO and busulfan groups. Furthermore, the result showed that the expression of c-kit and STRA8 were significantly decreased in busulfan and busulfan/SCs groups, at 8 weeks after the last injection (p<0.001), but no significant decrease was found for PCNA, compared to the control and DMSO groups (P<0.05). CONCLUSION: These findings suggest that SCs transplantation may be beneficial as a practical approach for therapeutic strategies in reproductive and regenerative medicine. We further highlighted the essential applications that might provide a mechanism for correcting fertility in males, suffering from cell deformity.

Effect of insulin on functional parameters of human cryopreserved sperms.

Cryopreservation of sperms is common therapy but with multiple damages to sperms. The aim of this study was to assess the effect of insulin as a prosurvival factor on the most important functional parameters of human spermatozoa during cryopreservation. Semen samples were obtained from 15 normozoospermic men at age 25-40 years of old through masturbation. Cryopreservation of sperms was conducted along with adding 10, 100, 500 and 1000 (ng/ml) insulin and a control group was also considered by adding distilled water. Samples were cryopreserved for 2 weeks in liquid nitrogen. Then, after thawing sperm motility; cytosolic/mitochondrial reactive oxygen species (ROS) levels; and DNA fragmentation were analyzed. Data were analyzed by SPSS software using one-way ANOVA. Results showed that insulin at all doses significantly decreased cytosolic ROS especially in 10 ng/ml group (P˂0.05). Mitochondrial ROS also decreased by adding insulin in comparison to the control group, although unmeaningfully (P˃0.05). Insulin at 1000 (ng/ml) decreased DNA fragmentation, significantly (P˂0.05). Also, the number of motile sperms increased in all insulin groups but it wasn't meaningful (P˃0.05). Based on our findings adding insulin to semen leads to protecting effects against cryopreservation damages and increases sperms motility. Therefore, using insulin for human semen seems to could be suggested for future clinical applications.