Age-related changes in human conventional semen parameters and sperm chromatin structure assay-defined sperm DNA/chromatin integrity.

RESEARCH QUESTION: What are the correlations between male age, traditional semen parameters, sperm DNA fragmentation index (DFI) and high DNA stainability (HDS) in a sufficiently large sample size? DESIGN: Retrospective cohort study of 18,441 semen samples, with data divided into seven age groups according to male age: ≤25, 26-30, 31-35, 36-40, 41-45, 46-50 and ≥51 years. RESULTS: Age was negatively correlated with semen volume, total sperm count, motility and HDS, and positively correlated with sperm concentration and DFI (P < 0.001). After 35 years of age, semen volume and total sperm count began to decline. After 30 years of age, motility and HDS decreased consistently. Sperm concentration and DFI increased from 26-30 years of age. DFI was negatively correlated with sperm concentration, total sperm count, motility and normal morphology (P < 0.001) and positively correlated with semen volume and HDS (P < 0.001). HDS was negatively correlated with all parameters (P < 0.001) except semen volume (r = -0.013, P = 0.074) and DFI (r = 0.124, P < 0.001). Patients aged ≥40 years had higher DFI than those aged <40 years in the entire cohort, in the abnormal semen parameters cohort, and in the normal semen parameters cohort (OR 2.145, 2.042, 1.948, respectively, P < 0.001). The ≥40 years age group had a lower HDS than the <40 years age group in the entire cohort and abnormal semen parameters cohort (OR 0.719, 0.677, respectively, P < 0.001). CONCLUSIONS: Ageing is a negative effector of sperm quantity and quality, and routine sperm parameters have weak but significant correlations with sperm DNA/chromatin integrity.

Downregulation of DJ-1 Fails to Protect Mitochondrial Complex I Subunit NDUFS3 in the Testes and Contributes to the Asthenozoospermia.

Asthenozoospermia (AS), an important cause of male infertility, is characterized by reduced sperm motility. Among the aetiologies of AS, inflammation seems to be the main cause. DJ-1, a conserved protein product of the PARK7 gene, is associated with male infertility and plays a role in oxidative stress and inflammation. Although our previous studies showed that a reduction in DJ-1 was accompanied by mitochondrial dysfunction in the sperm of patients with AS, the specific mechanism underlying this association remained unclear. In this study, we found that compared to the patients without AS, the expression of mitochondrial protein nicotinamide adenine dinucleotide dehydrogenase (ubiquinone) Fe-S protein 3 (NDUFS3) was also significantly decreased in the sperm of patients with AS. Similarly, decreased expression of DJ-1 and NDUFS3 and reduced mitochondria complex I activity were evident in a rat model of AS. Moreover, we showed that the interaction between DJ-1 and NDUFS3 in rat testes was weakened by ORN treatment. These results suggest that the impaired mitochondrial activity could be due to the broken interaction between DJ-1 and NDUFS3 and that downregulation of DJ-1 in sperm and testes contributes to AS pathogenesis.

PARK7 protein translocating into spermatozoa mitochondria in Chinese asthenozoospermia.

PARK7 (DJ1) is a multifunctional oxidative stress response protein that protects cells against reactive oxygen species (ROS) and mitochondrial damage. PARK7 defects are known to cause various physiological dysfunctions, including infertility. Asthenozoospermia (AS), i.e. low-motile spermatozoa in the ejaculate, is a common cause of human male infertility. In this study, we found that downregulation of PARK7 resulted in increased levels of lipid peroxide and ROS, decreased mitochondrial membrane potential, and reduced mitochondrial complex I enzyme activity in the spermatozoa from AS patients. Furthermore, it was observed that PARK7 was translocated into the mitochondria of damaged spermatozoa in AS. Finally, we examined the oxidative state of PARK7 and the results demonstrated the enhancement of oxidation, expressed by increased sulfonic acid residues, the highest form of oxidation, as the sperm motility decreased. Taken together, these results revealed that PARK7 deficiency may increase the oxidative stress damage to spermatozoa. Our present findings open new avenues of therapeutic intervention targeting PARK7 for the treatment of AS.

[Relationship of sperm morphology with reproductive hormone levels in infertile men].

OBJECTIVE: To investigate the relationship of sperm morphology with reproductive hormones in infertile men and the pathogenesis of teratozoospermia. METHODS: This study included 90 infertile men aged 25 - 40 years. We measured their testis volumes using the Prader orchidometer, conducted routine semen analyses according to the WHO laboratory standard, and determined the concentrations of reproductive hormones and sex hormone-binding globulin (SHBG) by chemiluminescence and the levels of free testosterone (FT) and bioavailable testosterone (BioT). RESULTS: All the subjects showed normal sperm concentration. Based on the results of semen morphology analysis, the 90 infertile men were equally divided into groups 1 (morphologically normal sperm <4%), 2 (morphologically normal sperm > or = 4% and <10%), and 3 (morphologically normal sperm > or = 10%), with no significant differences in age among the three groups (P>0.05). The volumes of the left testis were (14.27 +/- 3.65) ml, (16.90 +/- 3.57) ml and (14.57 +/- 3.57) ml, respectively (P = 0.006 group 1 vs group 2, P = 0.741 group 1 vs group 3, P = 0.014 group 2 vs group 3), and those of the right testis were (14.60 +/- 3.70) ml, (16.60 +/- 3.35) ml and (14.67 +/- 3.54) ml, respectively (P = 0.050). There were no significant differences among the three groups in prolactin, follicle-stimulating hormone, luteinising hormone, estradiol, total testosterone and SHBG, (P>0.05). The levels of serum FT were (0.25 +/- 0.07) nmol/L, (0.29 +/- 0.07) nmol/L and (0.31 +/- 0.13) nmol/L (P = 0.086 group 1 vs group 2, P= 0.010 group 1 vs group 3, P= 0.364 group 2 vs group 3), and those of BioT were (5.81 +/- 1.58) nmol/L, (6.78 +/- 1.55) nmol/L and (7.29 +/- 3.02) nmol/L, respectively (P = 0.086 group 1 vs group 2, P = 0.010 group 1 vs group 3, P = 0.364 group 2 vs group 3). The percentage of morphologically normal sperm was positively correlated with the levels of serum FT and BioT (P<0.05). CONCLUSION: The higher the levels of serum FT and BioT, the higher the percentage of morphologically normal sperm, which suggests that serum FT and BioT might be involved in the pathogenesis of teratozoospermia.

[Expression of Chk1 in human sperm and its significance].

OBJECTIVE: To investigate the expression of the Chk1 gene in human sperm and its clinical significance. METHODS: We collected 80 semen samples and divided them into 4 groups of equal number: normal, oligospermia, asthenozoospermia and oligoasthenozoospermia. The Chk1 expression and its relative level were detected by Western blot and RT-PCR, sperm DNA damage and gradient changes assessed by DNA ladder analysis, and sperm apoptosis determined by Annexin V/PI double staining in each group. RESULTS: The Chk1 gene was expressed in all the four groups, but with significant differences (P < 0.01); the relative levels of CHK1 protein were similar to those of Chk1 mRNA in the normal, oligospermia, asthenozoospermia and oligoasthenozoospermia groups, which were 1.00 +/- 0.22, 0.76 +/- 0.10, 0.45 +/- 0.08 and 0.37 +/- 0.07, respectively. DNA ladder analysis showed a marked DNA ladder in the asthenozoospermia and oligoasthenozoospermia groups. Sperm apoptosis was markedly increased in the oligospermia, asthenozoospermia, oligoasthenozoospermia and 100% graded sperm groups ([ 8.3 +/- 0.60]%, [11.6 +/- 0.92]%, [12.5 +/- 1.43]% and [17.0 +/- 1.98]%), as compared with the normal group ([7.6 +/- 0.34]%) (P < 0.05). CONCLUSION: Chk1 is expressed in human sperm, but differently in different semen quality groups. And its expression is correlated with sperm DNA damage and apoptosis; its reduction may lead to declined sperm repair and increased sperm apoptosis and thus affect semen quality.

[Vasectomy not associated with prostate cancer: a meta-analysis].

OBJECTIVE: To evaluate the association between vasectomy and prostate cancer. METHODS: We searched comprehensively the databases, CBMDisc, CMCC, CMAC, CNKI (from 1978 to January 6, 2009), and PubMed (from 1965 to January 6, 2009) using the key words "vasectomy" and "prostate cancer", screened the retrieved literature according to the inclusion and exclusion criteria, performed a Meta-analysis with the software RevMan 4.2 after identification of the relevant data, and calculated the overall pooled OR (95% CI) as well as that of the association of prostate cancer with <20 and > or =20 yr vasectomy. RESULTS: A total of 20 088 cases and 232 506 controls in 27 reports (7 cohort and 20 case-control studies) were included in this investigation. The overall pooled OR (95% CI) was 1.10 (0.97-1.24), and those of <20 and > or =20 yr vasectomy were 0.94 (0.83-1.06) and 1.05 (0.90-1.23), respectively. CONCLUSION: No existing literature show any positive association between vasectomy and prostate cancer.

[Sperm mtDNA content and mtDNA4977bp deletion in normal and leukocytospermia men].

OBJECTIVE: To determine the sperm mtDNA content, mtDNA4977bp deletion and ROS in the seminal plasma of normal and leukocytospermia men, and to investigate the correlation of the changes of sperm mtDNA with the increase of leukocytes and reactive oxgygen species (ROS) in the seminal plasma. METHODS: Seventy-eight semen samples from leukocytospermia patients and 31 from healthy donors were divided into 3 layers, supernatant fluid, 30% sperm and 80% sperm, by Percoll gradient centrifugation, their sperm mtDNA content and mtDNA4977bp deletion quantitatively analyzed by real-time PCR, and the level of ROS determined by flow cytometry. RESULTS: The ROS in the seminal plasma and the sperm mtDNA contents of the three layers were all significantly higher in the leukocytospermia group than in the healthy control (P < 0.01). In the supernatant fluid and 80% layers, mtDNA4977bp deletion showed no obvious difference between the control and the leukocytospermia group, but was significantly higher in the 30% layer of the latter (P < 0.01). The ROS level was found positively correlated with the mtDNA content in the 30% (r = 0.347, P < 0.01) and the 80% layer (r = 0.456, P < 0.01), but not in the supernatant layer. CONCLUSION: The increase of leukocytes and ROS may be one of the causes of the enhanced sperm mtDNA content, but has no significant impact on the mtDNA4977bp deletion.

[Seminal plasma levocarnitine significantly correlated with semen quality].

OBJECTIVE: To investigate the relationship of seminal plasma levocarnitine with sperm concentration, vitality and motility. METHODS: Enrolled in this study were 64 infertile men, who were divided according to the results of routine sperm tests into a normozoospermia (n = 12), an oligozoospermia (n = 16), an asthenozoospermia (n = 20) and an oligoasthenozoospermia group (n = 16). The level of seminal plasma levocarnitine was detected by LC-MS-MS, the concentration of seminal plasma testosterone measured by chemiluminescence immunoassay, the correlation of seminal plasma levocarnitine with sperm concentration, motility and vitality determined by bivariate correlation analysis with SPSS15.0, and so was the correlation between the carnitine and sperm concentration by partial correlation analysis with seminal plasma testosterone as a control variable to exclude the influence of testosterone. RESULTS: The concentrations of total seminal plasma levocarnitine, free seminal plasma levocarnitine and seminal plasma acetolevocarnitine were (91.33 +/- 40.49) mg/L, (40.89 +/- 24.13) mg/L and (50.44 +/- 21.90) mg/L; the Pearson coefficients of correlation of the levocarnitine level with sperm motility, vitality and concentration were 0.161 (P = 0.235), 0.114 (P = 0.370) and 0.637 (P < 0.001), those of free seminal carnitine with sperm motility and vitality were 0.325 (P = 0.024) and 0.316 (P = 0.029), respectively, with the oligozoospermia group excluded, and that of partial correlation between the concentrations of seminal levocarnitine and sperm was 0.641 (P < 0.001). CONCLUSION: The level of seminal plasma levocarnitine is positively correlated with sperm motility and vitality, and more significantly with sperm concentration.

Single-Cell RNA Sequencing Analysis Reveals Sequential Cell Fate Transition during Human Spermatogenesis.

Spermatogenesis generates mature male gametes and is critical for the proper transmission of genetic information between generations. However, the developmental landscapes of human spermatogenesis remain unknown. Here, we performed single-cell RNA sequencing (scRNA-seq) analysis for 2,854 testicular cells from donors with normal spermatogenesis and 174 testicular cells from one nonobstructive azoospermia (NOA) donor. A hierarchical model was established, which was characterized by the sequential and stepwise development of three spermatogonia subtypes, seven spermatocyte subtypes, and four spermatid subtypes. Further analysis identified several stage-specific marker genes of human germ cells, such as HMGA1, PIWIL4, TEX29, SCML1, and CCDC112. Moreover, we identified altered gene expression patterns in the testicular somatic cells of one NOA patient via scRNA-seq analysis, paving the way for further diagnosis of male infertility. Our work allows for the reconstruction of transcriptional programs inherent to sequential cell fate transition during human spermatogenesis and has implications for deciphering male-related reproductive disorders.

[An approach to male infertility from economic sociology].

OBJECTIVE: To study the psychology of infertility patients from the perspective of economic sociology so as to prevent the patients from medical frauds in seeking medical treatment. METHOD: We investigated 902 infertility patients of the Third Hospital of Peking University from September 2005 to January 2006 using a randomized questionnaire. RESULTS: Of the total number, 84.4% had education below college level; the majority had a low monthly family income, 36.6% below Y1,000, 19.7% from Y1,000 to Y2,000, 16.5% from Y2,000 to Y3,000, 7.8% from Y3,000 to Y4,000 and 19.4% above Y4,000; 88.7% had a strong desire for a child; 60.3% were psychologically stressed. As for the advertisements for the treatment of infertility, 50.2% of the patients disbelieved them, 6.2% wanted to have a try and about 43.6% accepted them to be true. Regarding the treatment in individual hospitals, 55.2% disbelieved in it, 5.8% wanted to try it and about 39.0% believed in it. CONCLUSION: Infertility patients of low economic status usually have a lower educational level but a higher desire for children, and therefore are more likely to be the victims of medical frauds and more psychologically stressed. It calls for our attention how to provide them with medical help.

[Aildenafil citrate: a new potent and highly selective phosphodiesterase type 5 inhibitor for the treatment of erectile dysfunction].

OBJECTIVE: To evaluate the efficacy and safety of aildenafil citrate, an oral phosphodiesterase type 5 inhibitor, in the treatment of erectile dysfunction. METHODS: Integrated analyses were made of 8-week, randomized, double-blind, placebo-controlled phase 2 clinical trials involving 250 men with mild-to-severe erectile dysfunction of various etiologies who received aildenafil citrate 30 or 60 mg (n = 167) or placebo (n = 83). RESULTS: The statistic results of International Index of Erectile Function, Patient Sexual Encounter Profile (SEP) diaries and Global Assessment Question (GAQ) were significantly higher in the aildenafil citrate patients than in the placebo controls. The main drug-related adverse events were flushing, headache, dizziness and naupathia, which were mild and could be self-relieved. CONCLUSION: The aildenafil citrate therapy significantly ameliorated erectile function and was well tolerated by a wide range of patients with erectile dysfunction.

Down-regulation of DJ-1 protein in the ejaculated spermatozoa from Chinese asthenozoospermia patients.

OBJECTIVE: To determine whether the expression of DJ-1 protein, whose levels in spermatozoa have been reported to be highly correlated with male infertility caused by toxicants, is changed in spermatozoa of Chinese asthenozoospermia patients. DESIGN: DJ-1 measurement by Western blotting, quantitive ELISA, and isoelectric-focusing electrophoresis (IFE) combined with immunoblotting. SETTING: Academic medical center and research laboratories. PATIENT(S): Asthenozoospermia patients (n = 113), including mild asthenozoospermia patients (n = 70) and moderate asthenozoospermia patients (n = 43), and age-matched control subjects (n = 58). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): DJ-1 in spermatozoa was determined by Western blotting and ELISA, the isoelectric point (pI) of DJ-1 by IFE combined with immunoblotting, and sperm superoxide dismutase (SOD) activity by an assay kit. RESULT(S): The sperm DJ-1 concentration in moderate asthenozoospermia patients was lower than those in mild asthenozoospermia patients and control subjects. DJ-1 with a more acidic pI was increased in asthenozoospermia patients. Sperm SOD activity was decreased in asthenozoospermia patients. CONCLUSION(S): DJ-1 levels are reduced in moderate asthenozoospermia patients. DJ-1 concentration is positively correlated with sperm motility and sperm SOD activity indicated by partial correlation analysis.