Donatella Paoli

Mitochondrial membrane potential profile and its correlation with increasing sperm motility

OBJECTIVE To investigate sperm mitochondrial integrity through analysis of mitochondrial membrane potential (Δψ) and to correlate the energy status with variations in sperm motility. DESIGN Experimental study. SETTING Seminology Laboratory, University of Rome, Italy. PATIENT(S) Two hundred thirteen semen samples from the same number of patients, divided into two groups on the basis of their motility: group A, 185 samples with linear motility and group B, 28 samples with nonlinear motility. INTERVENTION(S) Evaluation of sperm motility. MAIN OUTCOME MEASURE(S) Sperm mitochondrial integrity evaluated with a fluorimetric method using the cationic lipophilic stain JC-1. RESULT(S) The mean FL2 (percentage of sperm with high and low ∆ψ) for group A was 46.19±23.25 and for group B, it was 48.32±24.43. There was no significant difference between the groups. There was a positive correlation between both FL2 and linear motility and FL2 and sperm vitality in group A; both correlations were statistically significant. In group B, there was a positive correlation between FL2 and nonlinear motility and FL2 and sperm vitality; again, both correlations were statistically significant. CONCLUSION(S) Our data reveal a positive correlation between total motility and Δψ, suggesting that sperm motility may be dependent on the functional integrity of the mitochondria.

The role of antioxidant therapy in the treatment of male infertility: An overview

In recent years, many studies have focused on the effect of oxidative stress, reactive oxygen species (ROS) and antioxidants on the male eproductive system. Under physiological conditions, sperm produces small amounts of ROS, which are needed for fertilisation, acrosome reaction and capacitation. However, if an increased production of ROS is not associated with a similar increase in scavenging systems, peroxidative damage of the sperm plasma membrane and loss of DNA integrity typically occur, which leads to cell death and reduced fertility. Furthermore, since there is no linear correlation between sperm quality and pregnancy rates, an improvement in semen parameters should not be the sole outcome considered in studies of antioxidant therapies. A definitive conclusion regarding the benefit of these therapies is difficult to obtain, as most of the previous studies lacked control groups, considered different antioxidants in different combinations and doses, or did not evaluate pregnancy rates in previously infertile couples. Even if beneficial effects were reported in a few cases of male infertility, more multicentre, double-blind studies performed with the same criteria are necessary for an increased understanding of the effects of various antioxidants on fertility.

Antisperm antibody detection: 2. Clinical, biological, and statistical correlation between methods

PROBLEM: In clinical andrology, the detection of antisperm antibodies (ASA) is regarded as one of the most important steps in the study of male infertility. This practice is generally accepted even though there is still some disagreement about the true meaning of antisperm immunity, and there remains a good deal of controversy about the test regarded as the most suitable for the detection of antibodies directed against sperm antigens. International Workshops have tried to standardize universally accepted protocols. A panel of three or four methods is generally advised to provide a correct and complete screening of patients with antisperm immunity.

Pesticide exposure and serum organochlorine residuals among testicular cancer patients and healthy controls

The incidence of testicular cancer (TC) has been increasing worldwide during the last decades. The reasons of the increase remains unknown, but recent findings suggest that organochlorine pesticides (OPs) could influence the development of TC. A hospital-based case-control study of 50 cases and 48 controls was conducted to determine whether environmental exposure to OPs is associated with the risk of TC, and by measuring serum concentrations of OPs, including p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE) isomer and hexachlorobenzene (HCB) in participants. A significant association was observed between TC and household insecticide use (odds ratio [OR] = 3.01, 95 % CI: 1.11-8.14; ORadjusted = 3.23, 95 % CI: 1.15-9.11). Crude and adjusted ORs for TC were also significantly associated with higher serum concentrations of total OPs (OR = 3.15, 95 % CI: 1.00-9.91; ORadjusted = 3.34, 95 % CI: 1.09-10.17) in cases compared with controls. These findings give additional support to the results of previous research that suggest that some environmental exposures to OPs may be implicated in the pathogenesis of TC.

Effect of endogenous and exogenous hormones on testicular cancer: the epidemiological evidence

Testicular cancer is the most common type of malignancy in men aged 15-40 years. Although its incidence has increased over the past 40 years in most countries, the reasons for this rise are unclear. It has been suggested that a relative excess of endogenous estrogens during prenatal life and/or later exposures to various occupational and environmental estrogenic chemicals such as organochlorine compounds may play a causal role in the etiology of testicular cancer, but the issue is still open to further research. The purpose for this review is to summarize the epidemiologic literature about hormonal factors, endogenous hormones and environmental xenoestrogens, and testicular carcinogenesis. Future studies need to (a) consider the possible synergistic effect of exposure to environmental xenoestrogens and sex hormones, (b) focus on the most vulnerable life stages of exposure to endocrine disruptors and testicular cancer risk, (c) assess the possible additive role of androgen secretion occurring during puberty in tumor progression, and (d) consider more systematically gene-environment interactions.

Sperm cryopreservation: Effects on chromatin structure

Cryopreservation is a technique that can keep sperm alive indefinitely, enabling the conservation of male fertility. It involves the cooling of semen samples and their storage at -196°C in liquid nitrogen. At this temperature all metabolic processes are arrested. Sperm cryopreservation is of fundamental importance for patients undergoing medical or surgical treatments that could induce sterility, such as cancer patients about to undergo genotoxic chemotherapy or radiotherapy, as it offers these patients not only the hope of future fertility but also psychological support in dealing with the various stages of the treatment protocols.Despite its importance for assisted reproduction technology (ART) and its success in terms of babies born, this procedure can cause cell damage and impaired sperm function. Various studies have evaluated the impact of cryopreservation on chromatin structure, albeit with contradictory results. Some, but not all, authors found significant sperm DNA damage after cryopreservation. However, studies attempting to explain the mechanisms involved in the aetiology of cryopreservation-induced DNA damage are still limited. Some reported an increase in sperm with activated caspases after cryopreservation, while others found an increase in the percentage of oxidative DNA damage. There is still little - and contradictory - information on the mechanism of the generation of DNA fragmentation after cryopreservation. More studies are needed to establish the true importance of such damage, especially to improve the results of ART.

Testicular cancer and sperm DNA damage: short- and long-term effects of antineoplastic treatment

The aim of this study was to investigate sperm DNA damage induced by chemo‐ and radiotherapy in patients with testicular cancer to provide data on the extent and persistence of nuclear damage that might affect individual reproductive potential. We evaluated pre‐ and post‐antineoplastic treatment sperm DNA integrity, expressed as DNA Fragmentation Index (DFI), in a large caseload of testicular cancer patients by sperm chromatin structure assay. The mean total DFI for all patients at T0 was 18.0 ± 12.5%. Sperm chromatin profile was markedly impaired at T3 (27.7 ± 17.4%) and T6 (23.2 ± 15.3%), improving considerably at T12 and T24 (14.0 ± 8.9% and 14.4 ± 10.3%). After chemotherapy, we found a marked increase in DFI at T3 and T6 and a significant reduction at T12 and T24 in comparison with the baseline. In contrast, DFI increased at T3 and T6 after radiotherapy but the subsequent reduction was far less marked, reaching baseline values at T12 and T24. Finally, post‐treatment DNA damage was not age or histotype dependent, but was more marked in the advanced stage of cancer. In this study, we showed that the chromatin profile may be affected in the months immediately following the end of the treatment, improving after 12–24 months. Our results thus indicate that post‐treatment DNA damage is influenced both by the type and intensity of the therapy and by the pathological and clinical stage of the disease.

Higher clusterin immunolabeling and sperm DNA damage levels in hypertensive men compared with controls

BACKGROUND Clusterin, a heterodimeric glycoprotein found at several sites in the human male reproductive tract, could be a marker of morphologically abnormal spermatozoa, while TUNEL positivity indicates DNA fragmentation. Metabolic disorders such as diabetes mellitus and obesity may compromise sperm quality and fertility of men; however, little evidence specifically links hypertension with the impairment of male reproductive function. METHODS By flow cytometric, immunofluorescence (TUNEL assay and clusterin immunolabeling) and immunohistochemical (peroxidase-streptavidin method) analyses, we have compared both clusterin- and TUNEL labeling in ejaculated spermatozoa from healthy normotensive donors and hypertensive subjects with the purpose to reveal possible differences between the two conditions. RESULTS Data analysis from the normotensive (n=25) and hypertensive subjects (n=25) demonstrate a significant correlation between high levels of clusterin immunolabeling and the presence of sperm DNA damage, which is often associated with abnormal morphology. In the normotensive subjects, a low percentage (15.3±4.5) of spermatozoa positive for high levels of clusterin was detected; however, this percentage significantly increased (30.9±13.0) (P<0.01) in hypertensive subjects. Standard semen evaluations does not reveal any significant differences between the two groups of subjects, except for a reduced forward motility and lower sperm vitality in the hypertensive subjects. CONCLUSIONS This pilot study strongly suggests a relationship between hypertension and markers indicative of poor sperm quality. In hypertensive subjects, high levels of clusterin immunolabeling identified a consistent fraction of ejaculated spermatozoa carrying both DNA fragmentation and strong morphological alterations, which was not correlated with age or with sperm cell mortality. The alternative possibility that sperm damage observed is due to adverse effects of anti-hypertensive drugs does not find support in the literature nor in the drug data sheets. The relationship observed between hypertension and human semen represents a novel and possibly relevant information to be considered in the study of male fertility.

Expression and localization of the sodium/iodide symporter (NIS) in testicular cells

Administration of radioiodine (I131) is currently exploited for both diagnostic and therapeutic treatment of thyroid cancer. Few data are available on the sodium/iodide symporter (NIS) expression in human testis, a particular important prerequisite to predict radioiodine accumulation in the gonads of males with thyroid cancer exposed to such a treatment. In this study, we analyzed the expression of NIS in mouse, rat and human normal testis in different stages of development. By using a quantitative RT-PCR, Western blot and immunohistochemical analysis, NIS mRNA and protein were measured in both fetal and adult testicular tissues. NIS transcript was detected in both fetal and adult testis, although its expression levels were approximately 10-fold less than in thyroid gland. Western blot analysis and immunohistochemistry showed the presence of NIS protein in germinal and Leydig cells, but not in Sertoli cells with prevalent expression in the cytosol compartment of the cells. Our study demonstrates that NIS transcript and protein are expressed in normal testis. Further studies will demonstrate whether it may act as the transporter of radioiodine in normal testis of male patients with thyroid cancer.

Influence of CAG Repeat Polymorphism on the Targets of Testosterone Action

In the last decade, ample evidence has demonstrated the growing importance of androgen receptor (AR) CAG repeat polymorphism in andrology. This genetic parameter is able to condition the peripheral effects of testosterone and therefore to influence male sexual function and fertility, cardiovascular risk, body composition, bone metabolism, the risk of prostate and testicular cancer, the psychiatric status, and the onset of neurodegenerative disorders. In this review, we extensively discuss the literature data and identify a role for AR CAG repeat polymorphism in conditioning the systemic testosterone effects. In particular, our main purpose was to provide an updated text able to shed light on the many and often contradictory findings reporting an influence of CAG repeat polymorphism on the targets of testosterone action.