Related Articles
Mutsaerts, Meike AQ | Groen, Henk | ter Bogt, Nancy CW | Bolster, Johanna HT | Land, Jolande A | Bemelmans, Wanda JE | Kuchenbecker, Walter KH | Hompes, Peter GA | Macklon, Nick S | Stolk, Ronald P | van der Veen, Fulco | Maas, Jacques WM | Klijn, Nicole F | Kaaijk, Eugenie M | Oosterhuis, Gerrit JE | Bouckaert, Peter XJM | Schierbeek, Jaap M | van Kasteren, Yvonne M | Nap, Annemiek W | Broekmans, Frank J | Brinkhuis, Egbert A | Koks, Carolien AM | Burggraaff, Jan M | Blankhart, Adrienne S | Perquin, Denise AM | Gerards, Marie H | Mulder, Robert JAB | Gondrie, Ed TCM | Mol, Ben WJ | Hoek, Annemieke
Background
In the Netherlands, 30% of subfertile women are overweight or obese, and at present there is no agreement on fertility care for them. Data from observational and small intervention studies suggest that reduction of weight will increase the chances of conception, decrease pregnancy complications and improve perinatal outcome, but this has not been confirmed in randomised controlled trials. This study will assess the cost and effects of a six-months structured lifestyle program aiming at weight reduction followed by conventional fertility care (intervention group) as compared to conventional fertility care only (control group) in overweight and obese subfertile women. We hypothesize that the intervention will decrease the need for fertility treatment, diminish overweight-related pregnancy complications, and will improve perinatal outcome.
Methods/Design
Multicenter randomised controlled trial in subfertile women (age 18-39 year) with a body mass index between 29 and 40 kg/m2. Exclusion criteria are azoospermia, use of donor semen, severe endometriosis, premature ovarian failure, endocrinopathies or pre-existent hypertensive disorders.
In the intervention group the aim is a weight loss of at least 5% to10% in a six-month period, to be achieved by the combination of a diet, increase of physical activity and behavioural modification. After six months, in case no conception has been achieved, these patients will start fertility treatment according to the Dutch fertility guidelines. In the control group treatment will be started according to Dutch fertility guidelines, independently of the patient's weight.
Outcome measures and analysis
The primary outcome measure is a healthy singleton born after at least 37 weeks of gestation after vaginal delivery. Secondary outcome parameters including pregnancy outcome and complications, percentage of women needing fertility treatment, clinical and ongoing pregnancy rates, body weight, quality of life and costs.
Data will be analysed according to the intention to treat principle, and cost-effectiveness analysis will be performed to compare the costs and health effects in the intervention and control group.
Discussion
The trial will provide evidence for costs and effects of a lifestyle intervention aiming at weight reduction in overweight and obese subfertile women and will offer guidance to clinicians for the treatment of these patients.
Trial registration
Dutch Trial Register NTR1530
doi:10.1186/1472-6874-10-22
PMCID: PMC2907305
PMID: 20579357
Purpose: To study the role of the autosomal candidate gene DAZLA (Deleted in AZoospermia Like Autosome) in male subfertility.
Methods: We reviewed clinical data of subfertile men with oligozoospermia or azoospermia, mostly candidates for intracytoplasmic sperm injection (ICSI). Mutation detection was performed using polymerase chain reaction followed by single strand conformation polymorphism analysis. All shifted bands were analyzed by sequencing.
Results: We searched for mutations in 44 subfertile men. Nine subfertile men were included, because family history showed that their brothers also faced fertility problems. In these men a possible autosomal gene defect may contribute to their fertility problem. No mutations were found, except for two polymorphisms in intron 4 and 5.
Conclusion: At this moment it does not seem relevant to search for possible mutations in the DAZLA gene in clinical practice.
doi:10.1023/A:1016678624225
PMCID: PMC3455824
PMID: 11499325
DAZLA; genetics; ICSI; male subfertility
Background
To gain more insight in whether failure of intrauterine insemination (IUI) treatment in patients with idiopathic subfertility could be related to diminished fertilization, the aim of this study is to compare the fertilization of an initial IVF procedure after six cycles of IUI and the fertilization of an initial IVF procedure without preceding IUI cycles in couples with idiopathic subfertility.
Methods
We performed a complimentary analysis of a randomized controlled trial, in which the number of total fertilization failure (TFF) in the first IVF procedure after unsuccessful IUI was compared to those of IVF without preceding IUI in patients with idiopathic subfertility. These patients participated in a previous study that assessed the cost effectiveness of IUI versus IVF in idiopathic subfertility and were randomized to either IUI or IVF treatment.
Results
45 patients underwent IVF after 6 cycles of unsuccessful IUI and 58 patients underwent IVF immediately without preceding IUI. In 7 patients the IVF treatment was cancelled before ovum pick. In the IVF after unsuccessful IUI group TFF was seen in 2 of the 39 patients (5%) versus 7 of the 56 patients (13%) in the immediate IVF group. After correction for confounding factors the TFF rate was not significantly different between the two groups (p = 0.08, OR 7.4; 95% CI: 0.5–14.9).
Conclusion
Our data showed that TFF and the fertilization rate in the first IVF treatment were not significantly different between couples with idiopathic subfertility undergoing IVF after failure of IUI versus those couples undergoing IVF immediately without prior IUI treatment. Apparently, impaired fertilization does not play a significant role in the success rate of IUI in patients with idiopathic subfertility.
doi:10.1186/1477-7827-7-3
PMCID: PMC2632644
PMID: 19138415
OBJECTIVE--To test the hypothesis that subfertility in men is familial and to examine the distribution of subfertility within families for consistency with a genetic cause. DESIGN--Case-control study and segregation analysis. SETTING--Two teaching hospitals in Leeds. SUBJECTS--Cases (probands) were men with an abnormal sperm count who attended a subfertility clinic and whose partners had no major factor contravening fertility. Controls were fathers of two or more children recruited through vasectomy clinics or a maternity department. MAIN OUTCOME MEASURES--The incidence of involuntary childlessness among brothers with partners and among sisters and second and third degree male relatives. When possible clinical and laboratory details were obtained from involuntarily childless brothers. RESULTS--Seventeen of the 148 (11.5%) brothers of probands but none of the 169 brothers of controls had sought medical advice for childlessness (P < 0.0005). Four probands had more than one involuntarily childless brother. There were six further brothers whose childlessness was thought to be involuntary bringing the total prevalence of subfertility among brothers of probands to 16%. Segregation analysis was consistent with an autosomal recessive mode of inheritance accounting for 60% of subfertility in men. Seventeen of the 346 (4.9%) uncles of probands and 10 of 420 (2.8%) uncles of controls were reported to be involuntarily childless (P = 0.09), but there was no difference in childlessness among sisters. In three families sperm counts from "affected" brothers confirmed the diagnosis and showed considerable similarities within but not between families. CONCLUSION--Subfertility in men has a familial component, and the observations are consistent with an autosomal recessive mode of inheritance in over half the cases. Several different genes are probably involved.
PMCID: PMC2541440
PMID: 8086942
Testicular biopsies from eight men with abnormal karyotypes have been examined for histological and cytogenetic evidence of disturbances of meiosis. Quantitative analysis of this material showed one, with a 13;14 Robertsonian translocation, to have apparently normal spermatogenesis. Three patients, one with a 47,XYY and two with 45,XY, inv 9 karyotypes, had an overall depression of spermatogenesis. Four others, all with major chromosomal abnormalities, had apparently normal spermatogenesis until the primary spermatocyte stage. Two of these had sex autosomal translocations. One, 45,Y,t(X;21), had a complete block at MI, the other, 46,X,t(Y;16), had a partial block at spermatid formation. One man with a reciprocal 2;10 translocation showed delay at all stages beyond spermatocyte formation and one man with an inversion of chromosome 3 showed impaired spermatid maturation.
Images
PMCID: PMC1048819
PMID: 7069747
Objective
To examine the association between body weight and measures of male reproductive potential.
Design
Cross-sectional study
Setting
Fertility clinic in an academic medical center.
Patients
483 male partners of subfertile couples.
Interventions
None
Main outcome measures
Standard semen analysis, sperm DNA fragmentation and serum levels of reproductive hormones.
Results
As expected, BMI was positively related to estradiol levels and inversely related to total testosterone and SHBG levels. There was also a strong inverse relation between BMI and inhibin B levels and a lower testosterone:LH ratio among men with a BMI ≥ 35kg/m2. BMI was unrelated to sperm concentration, motility or morphology. Ejaculate volume decreased steadily with increasing BMI levels. Further, men with BMI ≥ 35kg/m2 had a lower total sperm count (concentration × volume) than normal weight men (Adjusted difference in the median [95% CI] = −86 × 106 sperm [−134, −37]). Sperm with high DNA damage were significantly more numerous in obese men than in normal weight men.
Conclusions
These data suggest that despite major differences in reproductive hormone levels with increasing body weight, only extreme levels of obesity may negatively influence male reproductive potential.
doi:10.1016/j.fertnstert.2009.01.100
PMCID: PMC2864498
PMID: 19261274
BMI; obesity; semen analysis; sperm DNA; hormones; infertility
BACKGROUND
High isoflavone intake has been related to decreased fertility in animal studies, but data in humans are scarce. Thus, we examined the association of soy foods and isoflavones intake with semen quality parameters.
METHODS
The intake of 15 soy-based foods in the previous 3 months was assessed for 99 male partners of subfertile couples who presented for semen analyses to the Massachusetts General Hospital Fertility Center. Linear and quantile regression were used to determine the association of soy foods and isoflavones intake with semen quality parameters while adjusting for personal characteristics.
RESULTS
There was an inverse association between soy food intake and sperm concentration that remained significant after accounting for age, abstinence time, body mass index, caffeine and alcohol intake and smoking. In the multivariate-adjusted analyses, men in the highest category of soy food intake had 41 million sperm/ml less than men who did not consume soy foods (95% confidence interval = –74, –8; P, trend = 0.02). Results for individual soy isoflavones were similar to the results for soy foods and were strongest for glycitein, but did not reach statistical significance. The inverse relation between soy food intake and sperm concentration was more pronounced in the high end of the distribution (90th and 75th percentile) and among overweight or obese men. Soy food and soy isoflavone intake were unrelated to sperm motility, sperm morphology or ejaculate volume.
CONCLUSIONS
These data suggest that higher intake of soy foods and soy isoflavones is associated with lower sperm concentration.
doi:10.1093/humrep/den243
PMCID: PMC2721724
PMID: 18650557
soy; isoflavones; semen analysis; sperm concentration; infertility
Genital tract reconstruction has been attempted in subfertile men with obstructive azoospermia (370 patients) or unilateral testicular obstruction (80 patients), and in vasectomised men undergoing reversal for the first (130 patients) or subsequent (32 patients) time. Histopathological changes in the obstructed testes and epididymes, and immunological responses to the sequestered spermatozoa have been studied to gain insight into possible causes of failure of surgical treatment. The results of surgery have been assessed by follow-up sperm counts and occurrence of pregnancies in the female partners. The best results were obtained with vasectomy reversal (patency 90%, pregnancy 45%), even after failed previous attempts (patency 87%, pregnancy 37%). Epididymovasostomy gave good results with postinfective caudal blocks (patency 52%, pregnancy 38%), while postinfective vasal blocks were better corrected by total anatomical reconstruction (patency 73%, pregnancy 27%) than by transvasovasostomy (patency 9%, no pregnancies). Poor results were obtained with capital blocks (patency 12%, pregnancy 3%), in which substantial lipid accumulation was demonstrated in the ductuli efferentes; three-quarters of these patients had sinusitis, bronchitis or bronchiectasis (Young's syndrome). There is circumstantial evidence to suggest that this syndrome may be a late complication of mercury intoxication in childhood. After successful reconstruction, fertility was relatively reduced in those men who had antibodies to spermatozoa, particularly amongst the postinfective cases. Similarly, impaired fertility was found in men with unilateral testicular obstruction and antibodies to spermatozoa. Mononuclear cell infiltration of seminiferous tubules and rete testis was noted occasionally, supporting a diagnosis of autoimmune orchitis; although rare, this was an important observation as the sperm output became normal with adjuvant prednisolone therapy.
Images
PMCID: PMC2499292
PMID: 2241062
Background
Several studies have reported associations between solvent exposure and reduced female fertility, but the evidence is inconclusive for male fertility.
Objectives
To investigate the impact of solvent exposure on subfertility among families of male licensed pesticide applicators in the Agricultural Health Study cohort.
Methods
The couples enrolled between 1993 and 1997. Cross‐sectional questionnaire information on work tasks was used to assess exposure to solvents. The data were limited to couples (wife aged less than 40 years) with an attempt at pregnancy in the last four years (n = 2112).
Results
Twenty eight per cent of the couples were defined as subfertile (not conceiving a pregnancy after at least 12 months of unprotected intercourse, regardless of whether or not a pregnancy ultimately occurred). Adjusted subfertility odds ratios (OR) for exposure to solvents were calculated with logistic regression. Female (OR 1.42, 95% CI 1.15 to 1.75) and male exposure to solvents (OR 1.21 (95% CI 0.93 to 1.57) for monthly exposure and 1.40 (95% CI 0.97 to 2.03) for daily or weekly exposure) were associated with subfertility. In farming, spouses may share or exchange jobs. To account for potential dual exposure, variables for parental exposure (either parent exposed or both parents exposed) were also defined. Both were strongly associated with subfertility (OR 1.62 (95% CI 1.20 to 2.17) and OR 2.10 (95% CI 1.22 to 3.60), respectively).
Conclusions
Solvents may impair fertility of either gender, though the evidence for female effects is stronger than for male effects.
doi:10.1136/oem.2005.021337
PMCID: PMC2092515
PMID: 16698811
agriculture; female exposure; male exposure; solvent exposure; subfertility
Spermatogenesis is regulated by a cascade of steroid regulated genes in the testis. Recent studies suggested that acupuncture may improve fertility in men with abnormal semen parameters. Yet, the underlying mechanisms in which acupuncture enhances spermatogenesis remain largely unknown. Here we used a scrotal heat-treated rat model to study the effect of electroacupuncture (EA) on recovery of spermatogenesis. In this model, spermatogenesis was disrupted by 30 min scrotal heat treatment at 43°C. Ten sessions of EA were given at Baihui (GV20), Guanyuan (CV4), Zusanli (ST36) and Sanyinjiao (SP6) from day 9 to day 36 post-treatment. Sperm motility and production, morphology of the germinal epithelium by Johnsen’s scoring, germ cell apoptosis by TUNEL staining, proliferation by proliferating cell nuclear antigen (PCNA) staining, as well as serum testosterone and inhibin B levels by immunoassays were evaluated on day 0, 1, 9, 25, 37, 46, 56 and 79. When compared with the heat-treated (H) group, the heat-treated plus EA (H+EA) group showed a significant increase (p < 0.05) in PCNA-positive cells and inhibin B levels on days 37 and 46, and a higher Johnsen’s score till day 56. On day 79, motile spermatozoa could be found in the vas deferens of H+EA group only. Consistently, there was a trend of improved motility and increased number of motile epididymal spermatozoa in the H+EA group than the H group; while apoptosis of germ cells and serum testosterone levels were similar between the two groups. Taken together, EA enhanced germ cell proliferation through improvement of Sertoli cell functions. This may facilitate the recovery of spermatogenesis and may restore normal semen parameters in subfertile patients.
doi:10.4161/spmg.19282
PMCID: PMC3341246
PMID: 22553490
Apoptosis; electroacupuncture; proliferation; spermatogenesis; spermatozoa
Oxidative stress contributes to defective spermatogenesis and the poor quality of sperm associated with idiopathic male factor infertility. The aim of this study was to review the current literature on the effects of various types of antioxidant supplements in patients to improve fertilization and pregnancy rates in subfertile males with idiopathic oligoasthenoteratozoospermia (iOAT). Review of recent publications through PubMed and the Cochrane database. Oxidative stress is implicated in impaired spermatogenesis leading to the poor semen parameters and increased DNA damage and apoptosis in iOAT. Strategies to modulate the level of oxidative stress within the male reproductive tract include the use of oral antioxidant compounds to reinforce the body's defence against oxidative damage. In our evaluation, carnitines were considered the most established pharmacotherapeutic agent to treat iOAT, as evidence and data concerning carnitine supplementation have been shown to be most consistent and relevant to the population of interest. Other therapies, such as combined vitamin E and C therapy, are still considered controversial as vitamin C can act as a pro-oxidant in certain instances and the results of randomized controlled trials have failed to show significant benefit to sperm parameters and pregnancy rates. There is a need for further investigation with randomized controlled studies to confirm the efficacy and safety of antioxidant supplementation in the medical treatment of idiopathic male infertility as well as the need to determine the dosage required to improve semen parameters, fertilization rates and pregnancy outcomes in iOAT.
doi:10.4103/0970-1591.78437
PMCID: PMC3114591
PMID: 21716893
Antioxidants; idiopathic oligoasthenoteratozoospermia; male infertility; oxidative stress
Objectives
To identify lifestyle factors associated with subfertility (time to pregnancy >12 months) among women attending an antenatal clinic, and to determine whether this changed from 2001 to 2007.
Methods
Waiting-room surveys administered in 2001 and 2007.
Results
There were significant changes in lifestyle factors between 2001 and 2007, including such factors as previous contraceptive use and obesity, smoking, alcohol and caffeine intake of both partners. All changes were in the direction favourable to health and fertility. However, despite these health improvements, there was no overall decrease in the prevalence of subfertility in the antenatal population. Mathematical modelling showed that even if the entire population had improved their lifestyle this would have made little difference to the proportion of subfertile couples.
Conclusions
A modest improvement in lifestyle over a period of 6 years in couples trying to conceive a pregnancy did not lead to any reduction in the incidence of subfertility and even substantial changes would not have made a significant difference.
doi:10.3109/14647270903386807
PMCID: PMC3564671
PMID: 19895360
Infertility; subfertility; time to pregnancy; reproductive and sexual health
Background
An association between male subfertility and an increased risk of testicular cancer has been proposed, but conflicting results of research on this topic have rendered this theory equivocal. To more precisely assess the association between subfertility and the risk of testicular cancer, we performed a systematic review of international epidemiologic evidence.
Principal Findings
We searched the Medline database for records from January 1966 to March 2008 complemented with manual searches of the literature and then identified studies that met our inclusion criteria. Study design, sample size, exposure to subfertility and risk estimates of testicular cancer incidence were abstracted. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated using the DerSimonian and Laird model. All statistical tests were two-sided. We identified seven case-control studies and two cohort studies published between 1987 and 2005. Analysis of the seven case-control studies that included 4,954 participants revealed an overall statistically significant association between subfertility and increased risk of testicular cancer (summary RR = 1.68, 95% CI: 1.22 to 2.31), without heterogeneity between studies (Q = 8.46, P heterogeneity = 0.21, I2 statistics = 0.29). The association between subfertility and testicular cancer was somewhat stronger in the United States (summary RR = 1.75, 95% CI: 1.01 to 3.02) than it was in Europe (summary RR = 1.53, 95% CI: 1.22 to 1.92). The source of the control subjects had a statistically significant effect on the magnitude of the association (population-based summary—RR = 2.15, 95% CI: 1.11 to 4.17; hospital-based summary—RR = 1.56, 95% CI: 0.93 to 2.61). After excluding possible cryptorchidism, an important confounding factor, we also found a positive association between subfertility and increased risk of testicular cancer (summary RR = 1.59, 95% CI: 1.28 to 1.98). These results were consistent between studies conducted in the United States and in Europe (Q = 0.20, P heterogeneity = 0.66). Of the two cohort studies that reported standardized incidence ratios, both reported a statistically significant positive association between subfertility and increased risk of testicular cancer.
Conclusions
Our findings support a relationship between subfertility and increased risk of testicular cancer and apply to the management of men with subfertility, and prevention and diagnosis of testicular cancer.
doi:10.1371/journal.pone.0005591
PMCID: PMC2680046
PMID: 19440348
Introduction
Microarray gene‐expression profiling is a powerful tool for global analysis of the transcriptional consequences of disease phenotypes. Understanding the genetic correlates of particular pathological states is important for more accurate diagnosis and screening of patients, and thus for suggesting appropriate avenues of treatment. As yet, there has been little research describing gene‐expression profiling of infertile and subfertile men, and thus the underlying transcriptional events involved in loss of spermatogenesis remain unclear. Here we present the results of an initial screen of 33 patients with differing spermatogenic phenotypes.
Methods
Oligonucleotide array expression profiling was performed on testis biopsies for 33 patients presenting for testicular sperm extraction. Significantly regulated genes were selected using a mixed model analysis of variance. Principle components analysis and hierarchical clustering were used to interpret the resulting dataset with reference to the patient history, clinical findings and histological composition of the biopsies.
Results
Striking patterns of coordinated gene expression were found. The most significant contains multiple germ cell‐specific genes and corresponds to the degree of successful spermatogenesis in each patient, whereas a second pattern corresponds to inflammatory activity within the testis. Smaller‐scale patterns were also observed, relating to unique features of the individual biopsies.
doi:10.1136/jmg.2007.049650
PMCID: PMC2597934
PMID: 17496197
testis; infertility; microarray; spermatogenesis; germ cell
Objectives To assess gestational length and prevalence of preterm birth among medically and naturally conceived twins; to establish the role of zygosity and chorionicity in assessing gestational length in twins born after subfertility treatment.
Design Population based cohort study.
Setting Collaborative network of 19 maternity facilities in East Flanders, Belgium (East Flanders prospective twin survey).
Participants 4368 twin pairs born between 1976 and 2002, including 2915 spontaneous twin pairs, 710 twin pairs born after ovarian stimulation, and 743 twin pairs born after in vitro fertilisation or intracytoplasmic sperm injection.
Main outcome measures Gestational length and prevalence of preterm birth.
Results Compared with naturally conceived twins, twins resulting from subfertility treatment had on average a slightly decreased gestational age at birth (mean difference 4.0 days, 95% confidence interval 2.7 to 5.2), corresponding to an odds ratio of 1.6 (1.4 to 1.8) for preterm birth, albeit confined to mild preterm birth (34-36 weeks). The adjusted odds ratios of preterm birth after subfertility treatment were 1.3 (1.1 to 1.5) when controlled for birth year, maternal age, and parity and 1.6 (1.3 to 1.8) with additional control for fetal sex, caesarean section, zygosity, and chorionicity. Although an increased risk of preterm birth was therefore seen among twins resulting from subfertility treatment, the risk was largely caused by a first birth effect among subfertile couples; conversely, the risk of prematurity was substantially levelled off by the protective effect of dizygotic twinning.
Conclusions Twins resulting from subfertility treatment have an increased risk of preterm birth, but the risk is limited to mild preterm birth, primarily by virtue of dizygotic twinning.
doi:10.1136/bmj.38625.685706.AE
PMCID: PMC1285094
PMID: 16249191
Background
Ovarian Reserve (OR) is a term which describes the functional potential of the ovary, which constitutes the size of the ovarian follicle pool and reflects the number and quality of the oocytes which are within it. Assessment of the OR helps in reflecting the reproductive potential of women. Various markers are available for assessing the OR and the best marker is the Anti Mullerian Hormone (AMH) which reflects the ovarian follicular pool in the ovary. In this study, the serum level of AMH/MIS(Mullerian Inhibiting Substance)was estimated to assess the ovarian reserve in both fertile and infertile women.
Objective
To assess the ovarian reserve in women of the fertile and subfertile groups with regular cycles, who were in the age range of 26 -33yrs, by estimating the level of AMH and those of other hormones like FSH and E2 and also to calculate the ovarian volume and the Antral follicular count by an ultrasonographic method.
Materials and Methods
Thirty fertile and thirty sub fertile women whose ages ranged from 26-33yrs were included as group 1 and group 2 respectively. The hormones like AMH ,FSH and oestradiol were assayed. Measurement of the ovarian volume and the antral follicular count by doing a transvaginal ultrasonogram, was done in all the subjects who were involved in both the groups. The correlation test was studied between the variables and the test of significance of the variables between the 2 groups was also analyzed by the Statistical Package Of Social Sciences (SPSS).
Results
The Antral Follicular Count (AFC) and the ovarian volume were negatively correlated with the age. The ovarian volume was positively correlated with the AFC. The FSH negatively correlated with the AFC. The Anti Mullerian Hormone negatively correlated with the age, and it positively correlated with the AFC. The mean values of AFC, FSH, and AMH were also statistically significant between the two groups.
Conclusion
AMH can be considered as a marker for assessing the ovarian reserve, as it is cycle independent as compared to the other hormones. The women in the subfertile group with low levels of AMH should be insisted to proceed for ART as early as possible.
doi:10.7860/JCDR/2012/5101.2624
PMCID: PMC3552193
PMID: 23373017
Ovarian reserve; AMH; AFC
Berkowitz, Karen M. | Sowash, Aislinn R. | Koenig, Lydia R. | Urcuyo, Dawnette | Khan, Fahmida | Yang, Fang | Wang, P. Jeremy | Jongens, Thomas A. | Kaestner, Klaus H. | Schimenti, John C.
CHTF18 (chromosome transmission fidelity factor 18) is an evolutionarily conserved subunit of the Replication Factor C-like complex, CTF18-RLC. CHTF18 is necessary for the faithful passage of chromosomes from one daughter cell to the next during mitosis in yeast, and it is crucial for germline development in the fruitfly. Previously, we showed that mouse Chtf18 is expressed throughout the germline, suggesting a role for CHTF18 in mammalian gametogenesis. To determine the role of CHTF18 in mammalian germ cell development, we derived mice carrying null and conditional mutations in the Chtf18 gene. Chtf18-null males exhibit 5-fold decreased sperm concentrations compared to wild-type controls, resulting in subfertility. Loss of Chtf18 results in impaired spermatogenesis; spermatogenic cells display abnormal morphology, and the stereotypical arrangement of cells within seminiferous tubules is perturbed. Meiotic recombination is defective and homologous chromosomes separate prematurely during prophase I. Repair of DNA double-strand breaks is delayed and incomplete; both RAD51 and γH2AX persist in prophase I. In addition, MLH1 foci are decreased in pachynema. These findings demonstrate essential roles for CHTF18 in mammalian spermatogenesis and meiosis, and suggest that CHTF18 may function during the double-strand break repair pathway to promote the formation of crossovers.
Author Summary
Meiosis is the specialized process of cell division during germ cell development that results in formation of eggs and sperm. Genetic exchange between maternal and paternal chromosomes occurs during meiosis in a process called homologous recombination, in which DNA double- strand breaks are made and then repaired to allow DNA crossovers to form. These are essential processes that keep homologous chromosomes joined until anaphase I and ensure proper chromosome segregation. Errors in meiotic recombination lead to chromosome mis-segregation and ultimately aneuploidy, an abnormal chromosome number. Although it is well known that defects in these processes contribute greatly to infertility, birth defects, and pregnancy loss in humans, their molecular basis is not well understood. We demonstrate here a Chtf18 mutant mouse that exhibits subfertility and defects in meiotic recombination. Specifically, DNA double-strand breaks are incompletely repaired, DNA crossovers are significantly decreased, and homologous chromosomes separate during prophase I in Chtf18-null males. Our findings suggest roles for CHTF18 in DNA double-strand break repair and crossover formation, functions in mammals not previously known.
doi:10.1371/journal.pgen.1002996
PMCID: PMC3486840
PMID: 23133398
Spermatogenesis is a temperature-dependent process, and increases in scrotal temperature can disrupt its progression. We previously showed that heat stress causes DNA damage in germ cells, an increase in germ cell death (as seen on TUNEL staining), and subfertility. The present study evaluated the stress response in mouse testes following a single mild transient scrotal heat exposure (40°C or 42°C for 30 min). We investigated markers of three types of stress response, namely, hypoxia, oxidative stress, and apoptosis. Heat stress caused an increase in expression of hypoxia-inducible factor 1 alpha (Hif1a) mRNA expression and translocation of HIF1A protein to the germ cell nucleus, consistent with hypoxic stress. Increased expression of heme oxygenase 1 (Hmox1) and the antioxidant enzymes glutathione peroxidase 1 (GPX1) and glutathione S-transferase alpha (GSTA) was consistent with a robust oxidative stress response. Germ cell death was associated with an increase in expression of the effector caspase cleaved caspase 3 and a decrease in expression of the protein inhibitor of caspase-activated DNase (ICAD). Reduced expression of ICAD contributes to increased activity of caspase-activated DNase and is consistent with the increased rates of DNA fragmentation that have been detected previously using TUNEL staining. These studies confirmed that transient mild testicular hyperthermia results in temperature-dependent germ cell death and demonstrated that elevated temperature results in a complex stress response, including induction of genes associated with oxidative stress and hypoxia.
Testicular heat stress causes a hypoxic and oxidative stress response in the testis, which results in apoptosis mediated by caspase 3.
doi:10.1095/biolreprod.108.071779
PMCID: PMC2709966
PMID: 19144962
apoptosis; spermatogenesis; stress; testis
Purpose: To determine the frequency and type of microdeletions on the Y chromosome, and to evaluate cytogenetic findings in unselected ICSI candidates at a Danish Fertility Clinic.
Methods: Genomic DNA was extracted from blood samples, which were collected prospectively from 400 ICSI candidates attending the Fertility Clinic at Aarhus University Hospital, Denmark. Twenty-five sequence tagged sites (STSs) spanning the azoospermia factor (AZF) regions of the Y chromosome were amplified in 5 multiplex sets to investigate Y microdeletions. Semen analysis, karyotype analysis, and histological evaluation of testicular biopsies were also performed.
Results: Y microdeletions were detected in 3 (0.75%) of 400 unselected ICSI candidates. The frequency of Y microdeletions was found higher in azoospermic men (2%) than in oligozoospermic men (0.6%). Two patients having oligozoospermia had Y microdeletions in the AZFc region only, whereas the patient having azoospermia had Y microdeletions spanning the AZFb and AZFc regions. No microdeletion was detected in the AZFa region. Chromosomal anomalies were found in 6.1% of azoospermic men and in 2.7% of oligozoospermic men. A high frequency of cytogenetic abnormalities was found in normozoospermic men with fertilization failure (7.4%).
Conclusions: The frequency of Y microdeletions both in the unselected ICSI candidates and subgroups classified as azoospermic and oligozoospermic seems rather low compared to results of previous studies, which have been quite varying. It is possible that in addition to patient selection criteria, ethnical and geographical differences may contribute to these variations. Cytogenetic evaluation of normozoospermic men with fertilization failure seems indicated because of a high frequency of cytogenetic abnormalities.
doi:10.1023/A:1015358802577
PMCID: PMC3468230
PMID: 12099553
Intracytoplasmic sperm injection; karyotyping; male infertility; oligo-azoospermia; Y-chromosome microdeletions
Two T7OH/+ translocation-carrying male mice were used in an investigation into the relation between the segregation pattern of the translocation caused multivalent at anaphase I and the position of the only chiasma in a long interstitial segment. Moreover, the relation between meiotic stage (from early diakinesis to metaphase I) and chiasma movement was assessed. It appeared that pronounced movement of a chiasma within the multivalent was linked with chiasma terminalization in an adjacent segment, either on the same side of the translocation breakpoint or on the other side. On summing the CIV and CIII+I configurations (making up 97.9% of all configurations found) and focusing on the multivalents from late meiotic cells, 41.3% had a proximal chiasma in the long interstitial segment of the multivalent. In total, a percentage of 33.5% of all secondary spermatocytes were characteristic of adjacent-2 segregation (i.e., homologous centromeres move to the same pole at anaphase I). Results obtained with T7OH translocation trisomics, which are briefly discussed in this paper, confirm the tendency of proximal chiasma frequencies in late meiotic cells to coincide with the frequency of absence of homologous centromere separation within the T7OH translocation multivalent. The importance of this phenomenon for normal bivalent behavior during anaphase I is considered.
PMCID: PMC1637662
PMID: 499122
BACKGROUND
Post-transcriptional modification by SUMOylation is involved in numerous cellular processes including human spermatogenesis. For human male meiosis, we previously showed that the small ubiquitin-related modifier-1 (SUMO-1) protein localizes to chromatin axes in early pachytene spermatocytes, then to kinetochores as meiosis progresses. Here, we delineate possible functional roles based on subcellular localization for SUMO-1 and SUMO-2/3.
METHODS
Western and immunoprecipitation analyses were conducted on proteins isolated from the testis of two normal adult fertile men. Combinatorial immunofluorescence and chromosome-specific fluorescence in situ hybridization analyses were performed on male meiocytes obtained during testicular biopsy from four patients undergoing testicular sperm extraction for assisted reproduction technologies.
RESULTS
The synaptonemal complex (SC) and SC proteins (SCP)-1 and SCP2, but not SCP3, are SUMOylated by SUMO-1 during the pachytene substage. Likewise, two distinct localization patterns for SUMO-1 are identified: a linear pattern co-localized with autosomal SCs and isolated SUMO-1 near the centromeric heterochromatin of chromosomes 9 and 1. In contrast to SUMO-1, which is not detectable prior to pachytene in normal tissue, SUMO-2/3 is identified as early as leptotene and zygotene and in some, but not all, pachytene cells; no linear patterns were detected. Similar to SUMO-1, SUMO-2/3 localizes in two predominant subnuclear patterns: a single, dense signal near the centromere of human chromosome 9 and small, individual foci co-localized with autosomal centromeres.
CONCLUSIONS
Our data suggest that SUMO-1 may be involved in maintenance and/or protection of the autosomal SC. SUMO-2/3, though expressed similarly, may function separately and independently during pachytene in men.
doi:10.1093/humrep/den300
PMCID: PMC2583944
PMID: 18694876
small ubiquitin-related modifier-1; men; meiosis; heterochromatin; chromosome
The guanosine trisphosphatase Rap1 serves as a critical player in signal transduction, somatic cell proliferation and differentiation, and cell–cell adhesion by acting through distinct mechanisms. During mouse spermiogenesis, Rap1 is activated and forms a signaling complex with its effector, the serine-threonine kinase B-Raf. To investigate the functional role of Rap1 in male germ cell differentiation, we generated transgenic mice expressing an inactive Rap1 mutant selectively in differentiating spermatids. This expression resulted in a derailment of spermiogenesis due to an anomalous release of immature round spermatids from the seminiferous epithelium within the tubule lumen and in low sperm counts. These spermiogenetic disorders correlated with impaired fertility, with the transgenic males being severely subfertile. Because mutant testis exhibited perturbations in ectoplasmic specializations (ESs), a Sertoli–germ cell-specific adherens junction, we searched for expression of vascular endothelial cadherin (VE-cadherin), an adhesion molecule regulated by Rap1, in spermatogenic cells of wild-type and mutant mice. We found that germ cells express VE-cadherin with a timing strictly related to apical ES formation and function; immature, VE-cadherin–positive spermatids were, however, prematurely released in the transgenic testis. In conclusion, interfering with Rap1 function during spermiogenesis leads to reduced fertility by impairment of germ–Sertoli cell contacts; our transgenic mouse provides an in vivo model to study the regulation of ES dynamics.
doi:10.1091/mbc.E06-10-0902
PMCID: PMC1838989
PMID: 17314400
Study Objective
To determine whether infertile women have lower antral follicle counts (AFC) than age-matched normal women
Design
Case- control
Setting
Academic center
Patients
881 infertile women and 771 women from the community
Interventions
Antral follicle count and basal hormone measurements
Main outcome measure(s)
Median AFCs and FSH levels were compared between the 2 groups within 5 year age strata, using the median test. A subanalysis was performed by identifying women in the control group with a history of attempting conception without success (Subfertile Group) and with a spontaneous conception in less than 12 months resulting in a live birth (Fertile Group). Age-specific AFC percentiles were calculated and compared within strata determined by age at the time of attempted conception
Results
AFCs were significantly lower in infertile women than in controls across age groups up to 40 years of age (P<0.001). Average FSH levels were significantly higher in the younger age infertile group vs. the community (P<0.005). AFC percentiles differ significantly between fertile and subfertile women within the community up until 40 years of age (P<0.02)
Conclusion
Decreased AFC in infertile women suggests that factors affecting the size of the remaining follicle pool in younger women also affect oocyte quality and the likelihood of conception
doi:10.1016/j.fertnstert.2011.01.151
PMCID: PMC3080442
PMID: 21376313
Antral follicle count; Decreased ovarian reserve; DOR; unexplained infertility; subfertile; FSH
Purpose:The creatine kinase level indicates sperm maturity and correlates with the spermatozoal fertilizing potential. The relationship between creatine kinase levels in subfertile men and their clinical diagnosis was examined.
Methods:Patients with unexplained infertility (n = 34), varicocele (n = 20), postvasectomy reversal (n = 7), or cancer (n = 22) were included in this prospective clinical study. The control group consisted of healthy normal donors (n = 15).
Results:The median and interquartile range values of creatine kinase for each group were as follows: normal donors, 0.061 U/108sperm (0.056 to 0.076 U/108sperm); idiopathic malefactor, 0.119 U/108sperm (0.061 to 0.190 U/108sperm); varicocele, 0.392 U/108sperm (0.209 to 1.494 U/108sperm); postvasectomy reversal, 0.589 U/108sperm (0.425 to 4.043 U/108sperm); and cancer, 0.068 U/108sperm (0.047 to 0.168 U/108sperm). Sperm creatine kinase levels were significantly higher in patients with varicocele compared to normal donors (P = 0.0001), cancer patients (P = 0.0002), and men with idiopathic infertility (P = 0.0009). Sperm concentration and creatine kinase level were inversely correlated in patients (r = −0.7,P < 0.001) but not in normal donors.
Conclusions:Semen quality is poorer in subfertile patients with clinical varicocele and postvasectomy reversal than in cancer patients and patients with idiopathic male infertility. That the creatine kinase levels in cancer patients were similar to those of normal donors suggests that the final phase of spermatogenesis may not be altered in men with cancer; thus semen from these patients should be banked to ensure fertility after cancer treatment.
doi:10.1023/A:1023096201880
PMCID: PMC3454933
PMID: 9565847
cancer patients; postvasectomy reversal; idiopathic infertility; sperm creatine kinase; varicocele
The interaction of the testis and gonadotropin secretion was studied in 15 men surviving chemotherapy for lymphoma. Azoospermia and complete destruction of all testicular germinal elements were present in 10 of the 15 men; however, Sertoli cells and Leydig cells were present. In these 10 men plasma follicle-stimulating hormone (FSH) levels were fourfold higher than in normal men of similar age whereas luteinizing hormone (LH) levels were normal. In contrast, both FSH and LH were normal in the remaining five men. Three had a full complement of spermatogenic tissue on biopsy and normal sperm concentrations. The other two men were azoospermic; one demonstrated full spermatogenesis in 30% of his tubules; the other had only a few spermatogonia in all tubules. In those patients with lower levels of gonadotropins pituitary insufficiency was excluded by the demonstration of appropriate responsiveness of FSH and LH to clomiphene administration. Similarly, Leydig cell function was normal since plasma testosterone was within the normal range in 13 of the 15 men and only slightly decreased in two. Thus, following chemotherapy, testicular damage was restricted to the germinal tissue, and this in turn was associated with a selective increase in FSH. The source of the FSH inhibitor is either the Sertoli cell or early germinal elements. However, since FSH levels are only half as high as those reported for castrate men, other testicular factors may modify FSH secretion.
Images
PMCID: PMC302213
PMID: 4552337