Spermatozoa Of Infertile Patients Research Articles

ROLE OF EMBRYO IGF2 IN THE ETIOLOGY OF THE LONG-TERM CONSEQUENCES OF ART IN OFFSPRING

A higher prevalence of myocardial dysfunction, blood hypertension, asthma, allergies, autism spectrum disorder, hypospadias, cryptorchidism, and cancer has been described in children conceived with assisted reproductive technology (ART) compared to those conceived spontaneously. The reasons are still unclear. Hypermethylation of the insulin-like growth factor 2/H19 differently methylated region (IGF2-H19 DMR) occurs in spermatozoa of infertile patients and can be transmitted on to offspring. In turn, this can lead to lower IGF2 expression in early-stage embryos.

Relationship between nuclear DNA fragmentation, mitochondrial DNA damage and standard sperm parameters in spermatozoa of infertile patients with leukocytospermia

The association of leukocytospermia with male fertility is still under debate. Our objective was to evaluate the association of leukocytospermia with sperm parameters, mitochondrial DNA (mtDNA) variations, and seminal concentration of several oxidative stress and inflammatory cytokines in Tunisian infertile men. The studied patients were divided into two groups: patients without leukocytospermia (Group 1) and patients with leukocytospermia (Group 2). DNA fragmentation significantly increased in group 2 (31.41 %) compared to group 1 (14.68 %) ; (p < 0.001). A total of 115 nucleotide substitutions in mitochondrial DNA were depicted, among which 113 were previously identified. The number of substitutions was more elevated in group 2. Leukocytospermic group had significantly higher MDA (nmole/mL) levels than patients without leukocytospermia (34±24.43 vs 18.94±15.96 ; p=0.001), GSH (μg/mL) levels were also higher compared to the control group (126.53±22.87 vs 79.4±19.38 ; p < 0.001), SOD (U/mg of protein) levels were higher but without reaching the statistical significance (89.74±74.85 vs 67.56±37.11 ; p = 0.25) ; whereas seminal CAT (μmole H2O2/min/mg of protein) levels were lower in this group (10.66±14.32 vs 27.35±25.28 ; p = 0.012). No statistically significant differences between the two groups of patients were found in the levels of inflammatory cytokines. However, IL-8 level was positively correlated with DNA fragmentation and negatively correlated with vitality. These findings confirm the association between leukocytospermia and sperm DNA damage.

PA-7 - Sperm DNA fragmentation – does age really matter?

Objective: Male fertility declines with increase in age where every single delayed year accounts to a considerable difference. Impaired fertilization, poor embryo and blastocyst development, lower implantation rates and higher instances of miscarriage are the adverse effects of damages in sperm DNA, thereby affecting fertility. Factors contributing to sperm DNA damage can be both internal and external. Intrinsic factors include protamine deficiency, mutations that affect DNA compaction, and advanced paternal age. High levels of reactive oxygen species (ROS') are detected in the semen of infertile men which directly or indirectly influences DNA fragmentation. In addition, certain external factors such as heat, chemotherapy, radiation, and others are also associated with an increase in DNA damage. Cigarette smoking, genital tract inflammation, varicoceles, and hormonal deficiencies have all been found to be the factors of DNA damage. To top it all, age is a constant factor influencing DNA fragmentation and chromosomal abnormalities in the spermatozoa of infertile patients and fertile men.

The role of the molecular chaperone heat shock protein A2 (HSPA2) in regulating human sperm-egg recognition.

One of the most common lesions present in the spermatozoa of human infertility patients is an idiopathic failure of sperm-egg recognition. Although this unique cellular interaction can now be readily by-passed by assisted reproductive strategies such as intracytoplasmic sperm injection (ICSI), recent large-scale epidemiological studies have encouraged the cautious use of this technology and highlighted the need for further research into the mechanisms responsible for defective sperm-egg recognition. Previous work in this field has established that the sperm domains responsible for oocyte interaction are formed during spermatogenesis prior to being dynamically modified during epididymal maturation and capacitation in female reproductive tract. While the factors responsible for the regulation of these sequential maturational events are undoubtedly complex, emerging research has identified the molecular chaperone, heat shock protein A2 (HSPA2), as a key regulator of these events in human spermatozoa. HSPA2 is a testis-enriched member of the 70 kDa heat shock protein family that promotes the folding, transport, and assembly of protein complexes and has been positively correlated with in vitro fertilization (IVF) success. Furthermore, reduced expression of HSPA2 from the human sperm proteome leads to an impaired capacity for cumulus matrix dispersal, sperm-egg recognition and fertilization following both IVF and ICSI. In this review, we consider the evidence supporting the role of HSPA2 in sperm function and explore the potential mechanisms by which it is depleted in the spermatozoa of infertile patients. Such information offers novel insights into the molecular mechanisms governing sperm function.

AB201. Sperm fluorescence in situ hybridization analysis of AZF cmicrodeletion in severe oligozoospermia

ObjectiveMicrodeletions of azoospermia factor (AZF) regions in Y chromosome were a genetic risk factor of spermatogenic failure and male infertility. Most laboratories carried out the AZF microdeletion testing by using peripheral intravenous blood, and AZF microdeletion in spermatozoa of infertile patients was sometimes not identical to that of peripheral intravenous blood due to the existence of mosaicism. The aim of this study was to summarize the data of sperm fluorescence in situ hybridization (FISH) analysis of AZF microdeletion in patients with severe oligospermia.Materials and methodsThe experiment included 16 patients with severe oligospermia which didn’t find AZF microdeletions in peripheral intravenous blood. Additionally, 2 normozoospermic cases and 2 oligozoospermiccases with AZF microdeletion were recruited as positive controls and as negative controls respectively. Frequency of AZF microdeletion in spermatozoa was detected by FISH with probes for chromosomes Y and chromosome 18, SRY gene was selected as the Y chromosome-specific signal, DAZ gene as AZFc-specific signal. A total of 100 spermatozoa were observed in each group.ResultsA total of 2,000 spermatozoa were counted from the semen samples in three groups. The hybridization rate was 97.2%, 95.3% and 96.4% in experiment group, positive group and negative group respectively. five out of 16 patients with severe oligospermia was found to bear DAZ gene signal missing in sperms with SRY signal, and the average missing rate was 8.7%. The positive control group was not found signal missing of DAZ gene in sperms with SRY signal, and DAZ gene signal was not found in the negative control groupConclusionsAZF microdeletions were not found in some patients with severe oligospermia via testing the peripheral intravenous blood, but sperm analysis by FISH revealed the presence of 8.7% abnormal spermatozoa with Y chromosome signal, in which DAZ gene signal were not found. This study is important to explain the mechanism of non-vertical transmission in patients with Y chromosome microdeletions, and can help to assess the genetic risk of Y chromosome microdeletions for male offspring and can be used for appropriate genetic counseling before the employment of assisted reproduction techniques.

Sperm fluorescence in situ hybridization analysis of AZFC microdeletion in severe oligozoospermia

Microdeletions of AZF (azoospermia factor) regions in Y chromosome were a genetic risk factor of spermatogenic failure and male infertility. Most laboratories carried out the AZF microdeletion testing by using peripheral intravenous blood, and AZF microdeletion in spermatozoa of infertile patients was sometimes not identical to that of peripheral intravenous blood due to the existence of mosaicism. The aim of this study was to summarize the data of sperm fluorescence in situ hybridization (FISH) analysis of AZFc microdeletion in patients with severe oligospermia.

The effects of male aging on semen quality, sperm DNA fragmentation and chromosomal abnormalities in an infertile population

To investigate the effects of male aging on semen quality, DNA fragmentation and chromosomal abnormalities in the spermatozoa of infertile patients and fertile men. Semen samples of 140 infertile patients (24-76years) and 50 men with proven fertility (25-65years) were analyzed according to WHO guidelines. DNA fragmentation was detected by TUNEL assay, while aneuploidy was assessed by FISH. In the patient group, semen volume and vitality of spermatozoa decreased significantly with age, while sperm concentration showed a statistically significant increase with age. DNA fragmentation as well as disomy of sex chromosomes and disomy 8 did not show a statistically significant change with age. However, the diploidy rate was significantly increased with patient's age. In the control group, conventional semen parameters as well as DNA fragmentation and chromosomal abnormalities did not show a statistically significant with age. Increased age in infertile men is associated with an increase in sperm concentration and diploidy, as well as a decline in semen volume and sperm vitality. However motility, morphology and DNA fragmentation are not affected by male age.

Flow cytometric determination of binding of monoclonal antibodies to human spermatozoa

Although several monoclonal antibodies to sperm antigens are available, only few systematical reports on the appearance of distinct antibody binding structures in spermatozoa of infertile patients are available. We studied the binding frequency of six monoclonal antibodies (TUS-1, -2, -10, -17, -19, -20) by means of a flow cytometer in different semen samples and their possible relationship to other sperm parameters, in particular to the motility parameters as determined by computer-assisted semen analysis. The percentage of vital spermatozoa binding the different antibodies was 21.5% (TUS-2) to 52.1% (TUS-20). The percentage binding was higher in samples with normozoospermia than in those with oligo-asthenoteratozoospermia. A significant correlation occurred between sperm concentration and the percentage of spermatozoa stained by TUS-2 and TUS-17; between motile spermatozoa and those binding TUS-17 and TUS-20; the velocity average path and those binding TUS-17; an inverse correlation occurred between the morphologically-abnormal spermatozoa and those binding TUS-20; an inverse correlation between TUS-17 and acrosin. We conclude from our results that although the antigens of the antibodies concerned are not yet characterized, the determination of antibody binding will give additional information on the functional status during capacitation and acrosome reaction of spermatozoa.

Citation classics in Fertility and Sterility, 1975–2004

Citation classics in Fertility and Sterility, 1975–2004

Molecular biology of human male infertility: links with aging, mitochondrial genetics, and oxidative stress?

Molecular biology of human male infertility: links with aging, mitochondrial genetics, and oxidative stress?

Formation of reactive oxygen species in spermatozoa of infertile patients

To determine the incidence of reactive oxygen species formation in semen of a population of patients consulting for infertility. The incidence of reactive oxygen species formation in whole semen and in washed spermatozoa was studied. The values obtained were correlated with semen parameters. The effect of the type of sperm washing on reactive oxygen species formation was also investigated. Semen samples from patients consulting for infertility and control subjects were obtained by masturbation after 3 days of sexual abstinence. Reactive oxygen species formation was measured in whole semen, sperm suspension washed by Percoll gradients, or repeated centrifugations. Sperm motility parameters were measured by computer-aided sperm analysis. Fertile control men and an unselected population of patients consulting for infertility. None. Reactive oxygen species formation by fresh semen specimen or washed spermatozoa was measured in a computer-driven LKB 1251 Luminometer (LKB-Wallac, Turku, Finland). Reactive oxygen species formation was detected in 40% of the semen with spermatozoa from infertile patients, whereas none was found in 6 azoospermic men and 10 control men. The level of reactive oxygen species formation was inversely correlated to the semen volume, the percentage of motile spermatozoa, and sperm linearity both in semen and in Percoll-washed spermatozoa. Washing by repeated centrifugation-resuspension increased 20- to 50-fold sperm reactive oxygen species formation. This enhancement was caused by the centrifugation itself and by the removal of seminal plasma. Both morphologically normal and abnormal spermatozoa produced reactive oxygen species. The data suggest that reactive oxygen species formation by spermatozoa may be a significant cause for male infertility.