Con Mallidis

Oxidative DNA damage in human sperm can be detected by Raman microspectroscopy

OBJECTIVE To determine whether Raman microspectroscopy can identify different levels of oxidative sperm nDNA damage and to corroborate the findings using an established method and an alternative but complementary spectroscopic technique. DESIGN Three-way comparison of Raman profiles, Fourier transform infrared spectroscopy (FTIR) spectra, and flow-cytometric assessments of sperm nDNA damage. SETTING University-based research laboratory. PATIENT(S) Thirty-eight men attending the infertility clinic at the Centre of Reproductive Medicine and Andrology. INTERVENTION(S) Induction of oxidative damage by Fentons reaction on semen samples. MAIN OUTCOME MEASURE(S) Raman profiles, FTIR spectra, and flow-cytometric analysis of DNA fragmentation. RESULT(S) Raman and FTIR spectra contained distinctive differences between untreated and fragmented nDNA sperm that were indicative of oxidative attack. The changes in Raman profiles were similar to those previously seen and corresponded to the DNA backbone. The peak attributions were corroborated by the FTIR spectra. Principal component analysis of the entire Raman spectra distinguished samples with varying degrees of damage. After determination of a cutoff value (0.63), estimation of the percentage of sperm with nDNA damage using the intensity ratio of Raman peaks (1,050/1,095 cm(-1)) correlated linearly to the flow-cytometric assessment. CONCLUSION(S) Raman microspectroscopy still requires further validation but may potentially provide a means of assessing the nDNA status of a living sperm.

Advanced glycation end products accumulate in the reproductive tract of men with diabetes

Light microscopic studies comparing sperm parameters show little association between diabetes and male fertility. However, with the introduction of new analytical techniques, evidence is now emerging of previously undetectable effects of diabetes on sperm function. Specifically, a recent study has found a significantly higher sperm nuclear DNA fragmentation in diabetic men. As advanced glycation end products (AGEs) are important instigators of oxidative stress and cell dysfunction in numerous diabetic complications, we hypothesized that these compounds could also be present in the male reproductive tract. The presence and localization of the most prominent AGE, carboxymethyl-lysine (CML), in the human testis, epididymis and sperm was determined by immunohistochemistry. Parallel ELISA and Western blot analyses were performed to ascertain the amount of CML in seminal plasma and sperm from 13 diabetic and nine non-diabetic subjects. CML immunoreactivity was found throughout the seminiferous epithelium, the nuclei of spermatogonia and spermatocytes, in the basal and principle cells cytoplasm and nuclei of the caput epididymis and on most sperm tails, mid pieces and all cytoplasmic droplets. The acrosomal cap, especially the equatorial band, was prominently stained in diabetic samples only. The amount of CML was significantly higher (p = 0.004) in sperm from non-diabetic men. Considering the known detrimental actions of AGEs in other organs, the presence, location and quantity of CML, particularly the increased expression found in diabetic men, suggest that these compounds may play a hitherto unrecognized role in male infertility.

The influence of type 1 diabetes mellitus on spermatogenic gene expression

Routine semen analysis found no differences in diabetic men; however, mRNA profiles showed changes in the expression of genes involved in oxidative stress.

Age and markers of Leydig cell function, but not of Sertoli cell function predict the success of sperm retrieval in adolescents and adults with Klinefelter's syndrome

Microsurgical testicular sperm extraction (mTESE), combined with intracytoplasmic sperm injection (ICSI) represents a chance for azoospermic men with Klinefelter′s syndrome (KS) to father children. The objective of this study was to identify predictive factors for the success of mTESE from adolescents and adults with KS.

Spermatogenic and sperm quality differences in an experimental model of metabolic syndrome and hypogonadal hypogonadism.

The synergistic effect of the co-morbidities that comprise metabolic syndrome (MetS) is increasingly being recognised as an important contributor in the pathology of a broad spectrum of seemingly disparate conditions. However, in terms of male reproductive function, beyond erectile dysfunction, little is known about the influence of this cohort (collectively or separately) on spermatogenesis and sperm quality. The aims of this study were to assess the reproductive tract of a MetS animal model for detrimental changes, to determine whether a group of compounds (advanced glycation end products and their receptor) known to cause cell dysfunction and DNA damage was present and assess whether hypogonadotropic hypogonadism was the main contributing factor for the changes seen. Animals fed a high-fat diet were found to have significantly increased cholesterol, triglycerides, blood glucose, mean arterial pressure and visceral fat levels. Although serum testosterone was decreased, no changes were seen in either testicular or epididymal histology. Immunolocalisation of N(ε)-carboxymethyl-lysine and the receptor for advanced glycation end products was found in the testes, epididymides and sperm of the two treated groups of animals; however, ELISA did not show any difference in protein levels. Similarly, assessment of sperm nuclear DNA (nDNA) fragmentation by acridine orange test did not find significant differences in nDNA integrity. We conclude that the minimal effect on spermatogenesis and sperm quality seen in our model is probably due to the moderate increase of blood glucose rather than the hypogonadism.

Differences in mouse models of diabetes mellitus in studies of male reproduction

Diabetes Mellitus (DM) has been found to have subtle yet profound effects on the metabolic status of the testis, the expression of numerous spermatogenic genes and is associated with increased numbers of sperm with nuclear DNA damage. The precise mechanism causing these detrimental effects remains unknown. The presence of increased levels of the most prominent member (carboxymethyllysine - CML) of the advanced glycation end product adducts and their receptor (RAGE) in the reproductive tract of DM men has provided a new avenue for research. As there are suspicions that the antibiotic (streptozotocin - STZ) employed to induce DM is also capable of causing oxidative stress and DNA damage, we compared CML and RAGE levels in the reproductive tract and sperm nDNA status of STZ mice with the levels in the Ins(2Akita) mouse to determine which more closely mimics the situation described in the human diabetic. CML was observed in the testes, epididymes and sperm of all animals. Sperm from DM mice showed particularly strong CML immunolocalization in the acrosomal cap, the equatorial region and whenever present, cytoplasmic droplets. Although increased, the level of CML on the sperm of the STZ and Ins(2Akita) DM mice did not reach statistical significance. RAGE was present on the developing acrosome and epididymal sperm of all animals and in discrete regions of the epididymes of the DM models. Only the epididymal sperm of the Ins(2Akita) mice were found to have significantly increased (p < 0.0001) nDNA damage. The Ins(2Akita) mouse therefore appears to more accurately reflect the conditions found in the human and, as such, is a more representative model for the study of diabetes and glycations influence on male fertility.

Structural and Functional Integrity of Spermatozoa Is Compromised as a Consequence of Acute Uropathogenic E. coli-Associated Epididymitis

ABSTRACT Uropathogenic Escherichia coli (UPEC)-associated epididymitis is commonly diagnosed in outpatient settings. Although the infection can be successfully cleared using antimicrobial medications, 40% of patients unexplainably show persistent impaired semen parameters even after treatment. Our aim was to investigate whether pathogenic UPEC and its associated virulence factor hemolysin (hlyA) perturb the structural and functional integrity of both the epididymis and sperm, actions that may be responsible for the observed impairment and possibly a reduction of fertilization capabilities. Semen collected from patients diagnosed with E. coli-only related epididymitis showed that sperm counts were low 14 days postantimicrobial treatment regardless of hlyA status. At Day 84 following treatment, hlyA production correlated with approximately 4-fold lower sperm concentrations than in men with hlyA-negative strains. In vivo experiments with the hlyA-producing UPEC CFT073 strain in a murine epididymitis model showed that just 3 days postinfection, structural damage to the epididymis (epithelial damage, leukocyte infiltration, and edema formation) was present. This was more severe in UPEC CFT073 compared to nonpathogenic E. coli (NPEC 470) infection. Moreover, pathogenic UPEC strains prematurely activated the acrosome in vivo and in vitro. Raman microspectroscopy revealed that UPEC CFT073 undermined sperm integrity by inducing nuclear DNA damage. Consistent with these observations, the in vitro fertilization capability of hlyA-treated mouse sperm was completely abolished, although sperm were motile. These findings provide new insights into understanding the possible processes underlying clinical manifestations of acute epididymitis.

UVB irradiation as a tool to assess ROS-induced damage in human spermatozoa.

One of the consequences of oxygen metabolism is the production of reactive oxygen species (ROS) which in a situation of imbalance with antioxidants can damage several biomolecules, compromise cell function and even lead to cellular death. The particularities of the sperm cell make it particularly vulnerable to ROS attack compromising its functionality, mirrored in terms of fertility outcome and making the study of the origin of sperm ROS, as well as the alterations they cause very important. In the present work, we used UVB irradiation, an easy experimental approach known as a potent inducer of ROS formation, to better understand the origin of ROS damage without any confounding effects that usually exist in disease models in which ROS are reported to play a role. To address these issues we evaluated sperm mitochondrial ROS production using the Mitosox Red Probe, mitochondrial membrane potential using the JC‐1 probe, lipid peroxidation through BODIPY probe and vitality using PI. We observed that UVB irradiation leads to an increase in sperm mitochondrial ROS production and lipid peroxidation that occur previously to an observable mitochondrial dysfunction. We concluded that sperm UVB irradiation appears to be a good and easily manipulated in vitro model system to study mitochondria‐induced oxidative stress in spermatozoa and its consequences, which may be relevant in terms of dissecting the action pathways of many other pathologies, drugs and contaminants, including endocrine disruptors.

Restoration of fertility by gonadotropin replacement in a man with hypogonadotropic azoospermia and testicular adrenal rest tumors due to untreated simple virilizing congenital adrenal hyperplasia

CONTEXT Classical congenital adrenal hyperplasia (CAH), a genetic disorder characterized by 21-hydroxylase deficiency, impairs male fertility, if insufficiently treated. PATIENT A 30-year-old male was referred to our clinic for endocrine and fertility assessment after undergoing unilateral orchiectomy for a suspected testicular tumor. Histopathological evaluation of the removed testis revealed atrophy and testicular adrenal rest tumors (TARTs) and raised the suspicion of underlying CAH. The remaining testis was also atrophic (5 ml) with minor TARTs. Serum 17-hydroxyprogesterone levels were elevated, cortisol levels were at the lower limit of normal range, and gonadotropins at prepubertal levels, but serum testosterone levels were within the normal adult range. Semen analysis revealed azoospermia. CAH was confirmed by a homozygous mutation g.655A/C>G (IVS2-13A/C>G) in CYP21A2. Hydrocortisone (24 mg/m(2)) administered to suppress ACTH and adrenal androgen overproduction unmasked deficient testicular testosterone production. As azoospermia persisted due to sustained hypogonadotropic hypogonadism, a combined s.c. gonadotropin replacement with human chorionic gonadotropin (hCG) (1500 IU twice weekly) and FSH (human menopausal gondadotropin (hMG) 150 IU three times weekly) was initiated. RESULTS Normalization of testosterone levels and a stable low sperm concentration (0.5 mill/ml) with good sperm motility (85% A+B progressive) were achieved within 21 months of treatment. Despite persisting TARTs, while receiving treatment, the patient successfully impregnated his wife twice, the latter impregnation leading to the birth of a healthy girl. CONCLUSIONS TARTs in unrecognized (simple virilizing) CAH may lead to unnecessary orchiectomy. In hypogonadotropic, azoospermic CAH, a combined treatment with oral corticosteroids and subcutaneously administered hCG and FSH can successfully restore testicular testosterone production and fertility, even if only one hypoplastic and atrophic testis with adrenal rest tumors is present.

Raman microspectroscopic discrimination of TCam-2 cultures reveals the presence of two sub-populations of cells.

TCam-2 cells are the main in vitro model for investigations into seminomatous tumors. However, despite their widespread use, questions remain regarding the cells’ homogeneity and consequently how representative they are of seminomas. We assess the TCam-2 cell line using routine and novel authentication methods to determine its homogeneity, identify any cellular sub-populations and resolve whether any changes could be due to generational differentiation. TCam-2, embryonal carcinoma cells (2102EP) and breast cancer cell (MCF7) lines were assessed using qRT-PCR, immunocytochemistry, flow cytometry and short tandem repeat analyses. Raman maps of individual cells (minimum of 10) and single scan spectra from 200 cells per culture were obtained. TCam-2s displayed the characteristic marker gene expression pattern for seminoma, were uniform in size and granularity and short tandem repeat analysis showed no contamination. However, based only on physical parameters, flowcytometry was unable to differentiate between TCam-2 and 2102EPs. Raman maps of TCam-2s comprised three equally distributed, distinct spectral patterns displaying large intercellular single spectral variation. All other cells showed little variation. Principal component, cluster and local spectral angle analyses indicated that the TCam-2s contained two different types of cells, one of which comprised two subgroups and was similar to some 2102EP cells. Protein expression corroborated the presence of different cells and generational differences. The detailed characterization provided by the Raman spectra, augmented by the routine methods, provide substantiation to the long-held suspicion that TCam-2 are not homogeneous but comprise differing cell populations, one of which may be embryonal carcinoma in origin.