MORN2 regulates the morphology and energy metabolism of mitochondria and is required for male fertility in mice

BACKGROUND

Mitochondria produce adenosine triphosphate through respiratory activities to power sperm differentiation and motility, and decreased mitochondrial respiratory activity can result in poor sperm motility and asthenospermia. The mitochondrial sheath is a component of the mid-piece of the sperm flagellum, and dysfunction of the sheath can reduce sperm motility and cause male infertility. The membrane occupation and recognition nexus-motif protein 2 (MORN2) is testis enriched in mice, and the MORN motif was reported to play a role in the regulation of bioelectrical signal homeostasis in cardiomyocytes.

METHODS

We generated Morn2-/- mice using CRISPR/Cas9 and evaluated the potential functions of MORN2 in spermiogenesis through histological analysis, fertility examination, RT-PCR, CASA, immunofluorescence, TUNEL, electron microscopy analysis, mitochondrial energy metabolism analysis, etc. RESULTS: The Morn2-/- mice were infertile, and their sperm showed severe motility defects. Morn2-/- sperm also had abnormal morphology characterized by bent heads, aberrant mitochondrial sheath formation, lower mitochondrial membrane potential, higher levels of reactive oxygen species, and decreased mitochondrial respiratory activity.

CONCLUSIONS

Our study demonstrates that MORN2 is essential for male fertility and indicates that MORN2 functions in mitochondrial sheath formation and regulates mitochondrial respiratory activity.

The Effect of Month-Long Daily Fasting on Semen Parameters: A Retrospective Cohort Study

OBJECTIVE

The aim of the study was to determine whether Ramadan month-long daily fasting affects semen analysis parameters.

METHODS

This retrospective cohort study was conducted in tertiary academic medical center. Medical records of 97 Muslim patients who were admitted to the IVF unit from May 2011 to May 2021 were reviewed. Only men who provided at least one semen sample during Ramadan period (Ramadan month +70 days after) and one sample not during Ramadan were included. Semen characteristics of each patient were independently compared to themselves.

RESULTS

The post-gradient semen analysis indicated significantly lower progressive sperm motility (mean 30.01 ± 20.46 vs. 38.12 ± 25.13) (p < 0.001). The decrease in the progressive motility remained significant among patients with non-male factor indications (p < 0.001). In the non-male factor indication group, the difference in the progressive motility of the post-gradient semen analysis between the 2 samples was not statistically significant (p = 0.4). There were no significant differences between semen parameters before centrifuging. The incidence of asthenospermia (progressive sperm motility <32%) as an absolute parameter was higher after centrifuging the semen sample during the Ramadan period (p = 0.04).

CONCLUSIONS

Semen samples collected during Ramadan period were associated with lower progressive motility and reduced semen volume compared to semen samples from the same men outside of the Ramadan period. A possible effect of these altered semen parameters on fertility should be investigated further.

Therapeutic potential of testosterone on sperm parameters and chromatin status in fresh and thawed normo and asthenozoospermic samples

BACKGROUND

Hormonal changes alter the physiological level of ROS and cause oxidative stress in the cell. As estimated, hormonal deficiencies, environmental and ideological factors make up about 25% of male infertility. Pathogenic reactive oxygen species (ROS) is a chief cause of unexplained infertility. Limited studies exist on the effects of testosterone on human sperm culture. Therefore, in the current study, the effect of different doses of testosterone on sperm parameters and chromatin quality was investigated.

MATERIALS AND METHODS

Semen samples from 15 normospermic and 15 asthenospermic patients were prepared by swim up method, and then were divided into four groups by exposing to different concentrations of testosterone (1, 10, and 100nM) for 45min. Samples without any intervention were considered as control group. All samples were washed twice. Sperm parameters and chromatin protamination were assessed in each group and the remains were frozen. After two weeks, all tests were repeated for sperm thawed. Also, the MSOM technique was used to determine the sperm morphology of class 1.

RESULTS

Although sperm parameters were not show any significant differences in normospermic and asthenospermic samples exposed to different concentrations of testosterone before and after freezing, chromatin protamination was significantly decreased in the normospermic samples exposed to 10nM of testosterone before freezing (p<0.006), as well as 1 and 10nM of testosterone after freezing compared to control samples (p=0.001 and p=0.0009, respectively). Similarly, chromatin protamination in the asthenospermic samples was significantly decreased at concentration of 1nM of testosterone before and after freezing (p=0.0014 and p=0.0004, respectively), and at concentration of 10nM of testosterone before and after freezing (p=0.0009, p=0.0007) compared to control samples.

CONCLUSION

Using a low dose of testosterone in the sperm culture medium, has positive effects on chromatin quality.

Modeling methods for busulfan-induced oligospermia and asthenozoospermia in mice: a systematic review and meta-analysis

OBJECTIVE

Modeling methods for busulfan-induced oligoasthenozoospermia are controversial. We aimed to systematically review the modeling method of busulfan-induced oligospermia and asthenozoospermia, and analyze changes in various evaluation indicators at different busulfan doses over time.

METHODS

We searched the Cochrane Library, PubMed databases, Web of Science, the Chinese National Knowledge Infrastructure, and the Chinese Biomedical Literature Service System until April 9, 2022. Animal experiments of busulfan-induced spermatogenesis dysfunction were included and screened. The model mortality and parameters of the evaluation indicators were subjected to meta-analysis.

RESULTS

Twenty-nine animal studies were included (control/model: 669/1829). The mortality of mice increased with busulfan dose. Significant spermatogenesis impairment occurred within 5 weeks, regardless of busulfan dose (10-40 mg/kg). Testicular weight (weighted mean difference [WMD]: - 0.04, 95% CI: - 0.05, - 0.03), testicular index (WMD: - 2.10, 95% CI: - 2.43, - 1.76), and Johnsen score (WMD: - 4.67, 95% CI: - 5.99, - 3.35) were significantly decreased. The pooled sperm counts of the model group were reduced by 32.8 × 106/ml (WMD: - 32.8, 95% CI: - 44.34, - 21.28), and sperm motility decreased by 37% (WMD: - 0.37, 95% CI: - 0.47, - 0.27). Sperm counts decreased slightly (WMD: - 3.03, 95% CI: - 3.42, - 2.64) in an intratesticular injection of low-dose busulfan (4 - 6 mg/kg), and the model almost returned to normal after one seminiferous cycle.

CONCLUSION

The model using low-dose busulfan (10 - 20 mg/kg) returned to normal after 10 - 15 weeks. However, in some spermatogenesis cycles, testicular weight reduction and testicular spermatogenic function damage were not proportional to busulfan dose. Sperm counts and motility results in different studies had significant heterogeneity. Standard protocols for sperm assessment in animal models were needed to reduce heterogeneity between studies.

Effect of Myo-inositol on sperm quality and biochemical factors in cryopreserved semen of patients with Asthenospermia

In this study, the influence of myoinositol (MYO) as an antioxidant on the inhibition of the negative impacts of cryopreservation on sperm quality in men with Asthenospermia was investigated. In this prospective study, each semen sample from 25 cases was separated into three groups: Fresh, Control (with freezing medium), Myoinositol (2 mg/ml). According to the World Health Organization criteria (WHO) (2010), total motility, progressive sperm motility, viability, normal morphology, and DNA integrity were assessed. In addition, the hypo-osmotic swelling (HOS) test and mitochondrial membrane potential (MMP) were used. Total antioxidant capacity (TAC), malondialdehyde (MDA), and antioxidant enzyme activity were determined by the ELISA method. In contrast to the fresh samples, lipid peroxidation, DNA integrity damage, DNA fragmentation, HOST, and MMP had significant enhancement in the control samples. Sperm quality was significantly decreased (p < 0.05). Mean percentage viability, normal morphology, total motility, progressive motility, and DNA integrity were significantly enhanced in the MYO group in comparison to the control group (p < 0.05). The MDA and TAC levels and DNA damage in the MYO group were significantly lower compared to the control group (p < 0.05). The findings confirm that sperm quality in patients with Asthenospermia is improved by the administration of 2 mg/ml of myoinositol together with the freezing medium after sperm cryopreservation.

Establishment of a Mouse Asthenospermia Model through Triggering DGalactose Mediated Oxidative Stress Injury

BACKGROUND

Asthenospermia is defined as forward motility of sperm less than 32%.

AIM/OBJECTIVE

This study aimed to establish mouse model of asthenospermia through triggering D-galactose mediated oxidative stress.

MATERIALS AND METHODS

Total of 40 Kunming male mice were randomly divided into control group, low-dose group (administrating D-galactose at 60 mg/kg), high-dose group (administrating D-galactose at 120 mg/kg) and high-dose+feed addition group (administrating D-galactose at 120 mg/kg together with oral D-galactose). The testicular weight, testicular organ coefficient, sperm viability, sperm concentration and survival rate of tail of epididymis were measured. Oxidative damage of D-galactose to reproductive system of mice was evaluated by measuring superoxide dismutase (SOD) and malondialdehyde (MDA) in testicular homogenate of mice.

FINDINGS

The sperm motility, motility rate, concentration and survival rate of low-dose, high-dose and high-dose+feed addition group were decreased, compared to that in control group. However, there were significant difference between highdose group/high dose+feed group and control group (p<0.05). The forward motile sperm motility rate and total motility rate accorded with critical criteria of asthenospermia. Comparing with the control group, activity of SOD of model group mice significantly decreased, and MDA concentration significantly increased (p<0.05), excepting for low-dose versus control group for SOD activity. This suggests that testicular tissues suffered from oxidative damage.

CONCLUSIONS

This study successfully established a mouse asthenospermia model through D-galactose mediated oxidative stress injury. The establishment of asthenospermia model in this study would provide a new promising insight and act as a potential approach for studying asthenospermia in vivo levels.

Identification and characterization of RSIY-11, a novel seminal peptide derived from semenogelin-1, which acts as a neutral endopeptidase inhibitor modulating sperm motility

PURPOSE

Based on prior reports demonstrating that neutral endopeptidase (NEP) inhibitors increase sperm motility, the goal of our studies was to identify endogenous seminal peptides that inhibit NEP and investigate their potential effect on sperm motility.

METHODS

Peptidomic analysis was performed on human seminal fluid, identifying 22 novel peptides. One peptide, named RSIY-11, derived from semenogelin-1, was predicted through sequence analysis to be a substrate and/or potential inhibitor of NEP. Enzymatic analysis was conducted to determine the inhibitory constant (Ki) of RSIY-11 as an inhibitor of NEP. Total and progressive sperm motility was determined at baseline and 30 and 60 min following addition of RSIY-11 to seminal fluid in 59 patients undergoing an infertility workup at an urban medical center. Additionally, the effects of RSIY-11 on sperm motility were evaluated in 15 of the 59 patients that met criteria for asthenospermia.

RESULTS

RSIY-11 was shown to act as a competitive inhibitor of NEP with a Ki of 18.4 ± 1.6 μM. Addition of RSIY-11 at concentrations of 0.75 μM, 7.5 μM, and 75 μM significantly increased sperm motility at all time points investigated, with increases of 6.1%, 6.9%, and 9.2% at 60 min, respectively. Additionally, within the subgroup of patients with asthenospermia, RSIY-11 at concentrations of 0.75 μM, 7.5 μM, and 75 μM significantly increased sperm motility at all time points investigated, with increases of 7.6%, 8.8%, and 10.6% at 60 min, respectively.

CONCLUSIONS

RSIY-11 is a newly identified semenogelin-1-derived peptide present in seminal fluid. RSIY-11 acts as a potent competitive inhibitor of NEP, which when added to seminal fluid significantly increases sperm motility. RSIY-11 could play a potential role in the treatment for male factor infertility related to asthenospermia and improve intrauterine insemination outcomes.

Is there any relationship between human sperm parameters and protamine deficiency in different groups of infertile men?

OBJECTIVE

Abnormality in Histone-Protamine replacements has been indicated to cause sperm DNA damage and infertility. The aim of the present study was to investigate the relationships between sperm parameters in oligospermia, asthenospermia, and teratospermia with protamine deficiency in infertile men.

MATERIAL AND METHOD

In this case-control study, we had three experimental groups including oligospermia (n=100), asthenospermia (n=100), and teratospermia (n=100) as well as normospermia (n=100) as controls. Sperm analyses were performed according to the recommendations of the World Health Organization (WHO, 2010) and sperm chromatin quality was assessed using Chromomycin A3 (CMA3) staining for each sample.

RESULTS

The comparison of the data between groups indicated that the percentage of spermatozoa with protamine deficiency was significantly different in patients with oligospermia, asthenospermia, and teratospermia when compared with control ones. However, there was no significant correlation between sperm nuclear protamine deficiency and their parameters of the men with teratospermia using CMA3 test. Regarding the oligospermia and asthenospermia semen samples, the findings showed the negative correlations between the sperm nuclear protamine deficiency and progressive motility as well as immobility (p<0.001).

CONCLUSION

The higher proportion of spermatozoa with abnormal chromatin packaging was observed in asthenospermic samples than those from other experimental groups as well as controls. It seems that normal morphology cannot have a valuable predictive value for good chromatin quality of spermatozoa, as much as normal motility characteristics, since samples with high mobility rates often have lower protamine deficiencies. The findings may provide a supportable promoting the future wider clinical application of chromatin/DNA integrity testing along with the semen analysis in male infertility.

[Impact of multiple morphological anomalies of the flagella on the outcomes of intracytoplasmic sperm injection for males with infertility]

Objective: To evalute the clinical outcomes of intracytoplasmic sperm injection(ICSI) for infertility male with severe asthenospermia induced by multiple morphological anomalies of the flagella (MMAF). Methods: The clinical data of 15 patient with MMAF were retrospectively analyzed, who underwent ICSI treatment using hyponotic swelling test the "live" sperm in the Department of Reproductive Medicine of Yantai Yuhuangding Hospital from January 2011 to December 2016. Another 30 obstructive azoospermia (OA)patients are matched strictly who also accepted ICSI in the same treatment time. The two groups were compared in the couples'age, the body mass index(BMI), the duration of infertility, the retrieved oocytes, the number of ICSI oocytes, and the rates of fertilization, cleavage, transferrable embryos, good embryos, embryos implanted, clinical pregncncy, early abortion, singleton and twins. Results: After 27 cycles of ICSI, all of the MMAF patients achieved clinical pregnancy, including 11 cases of live birth, 2 cases of spontaneous abortion, and 2 cases of pregnancy maintenance. There were no significant difference between MMAF and OA groups in the couples'age and BMI, or the numbers of retrieved oocytes and ICSI oocytes(P>0.05), but the differences in the infertility duration had statistical meaning(P<0.001). No statistical differences were observed among groups in ICSI fertility rate(92.0% vs 91.6%), clesvage rate(95.4% vs 96.5%), high-quality embryonic rate(56.5% vs 57.5%), good blastocyst rate(23/61 vs 35/94), embryo implantation rate(20/48 vs 35/75), early abortion rate(4/19 vs 8/36), clinical pregncncy rate(15/27 vs 28/50), singleton rate (10/13 vs 20/25)and twinning rate(3/13 vs 5/25)(P>0.05). Conclusions: MMAF may not affect ICSI treatment outcomes, but genetic defects can be transmitted through ICSI. The affected couples should be informed of the necessity of prenatal genetic diagnosis before embryo implantation and the inevitable vertical transmission of genetic problems to the offspring.

Effect of Oral Zinc Supplementation on the Thiol Oxido-Reductive Index and Thiol-Related Enzymes in Seminal Plasma and Spermatozoa of Iraqi Asthenospermic Patients

A thiol group plays an essential role in sperm metabolism and the antioxidative defense state. Zinc is the second most abundant element in the human body, following iron. The present study was conducted to study the effect of zinc supplementation on the characteristics of semen along with thiol and thiol-related enzymes in semen of asthenospermic patients. Semen samples were obtained from 60 fertile and 60 asthenospermic men, from couples who had consulted the infertility clinic of Babil Hospital (Hillah city, Iraq). The subfertile group was treated with zinc; every participant took two 220 mg capsules of zinc sulfate per day for 3 months. Semen samples were obtained (before and after zinc supplementation). The levels of reduced thiol, oxidized thiol, thiol oxido-reductive index, and thiol-related enzymes activities were determined in spermatozoa and seminal plasma of patients and healthy groups. Oxidized thiol levels were significantly higher in the infertile patients compared to that in the fertile group. Conversely, reduced thiol level, sulfhydryl oxidase activity, and glutathione peroxidase activity significantly decreased in the infertile patients compared to that in the fertile group. Oxidized thiol levels, reduced thiol levels, and thiol-related enzymes activities of the infertile patients were restored to normal values after treatment with zinc. However, reduced and oxidized thiol levels in spermatozoa did not change significantly in the group treated with zinc. The quantitative values for RSH/RSSR and thiol-related enzymes may provide useful means to qualitatively express the oxidant/antioxidant balance in clinical and epidemiologic studies. ClinicalTrials.gov Identifier: NCT02985905.

[Morphological characteristics and phenotypic analysis of multiple morphological abnormalities in sperm flagella]

Objective: To analyze the sperm morphological characteristics of multiple morphological abnormalities of the sperm flagella (MMAF), and to analyze their common features and subtypes. Methods: Twenty-eight patients with abnormal morphology of flagella were analyzed by semen analysis. The morphological characteristics were analyzed by scanning electron microscopy and transmission electron microscopy. Histological observation of one case of testicular tissue was performed. Results: Of the 28 patients, only 13 patients (46.4%) had motile spermatozoa, 12 of which had a sperm motility rate of <10% and a sperm survival rate of 9.0%-80.0%. Under light and scanning electron microscope, sperm with absent, short, coiled, bent and irregular width flagella or their combinations were observed. Transmission electron microscopy showed structural abnormalities of sperm fibrous sheath, mitochondrial sheath. Loss rate of central microtubule was 41.4%-84.6%. The semen of the 2 patients with the absence or presence of the kinetic protein arm and both the inner and lateral motilin arms missing had no motile spermatozoa. There was no statistically significant difference in the proportion of flagellar malformations between the two groups of patients (without motile sperm vs with motile spermatozoa). Conclusion: MMAF is a kind of sperm flagella specific abnormalities. Initially diagnosis can be carried out using light microscopy. Clear diagnosis could be conduct using transmission electron microscopy, and the central microtubule loss of the sperm could be seen as the main feature of the flagella abnormalities. Through the morphological analysis and research, MMAF could be precisely classified, which provide a strong basis for the diagnosis.

Fertility in men with spinal cord injury

Young men comprise the overwhelming majority of men with spinal cord injury (SCI), the incidence of which has been growing over the years. Due to advances in physical medicine and rehabilitation, remarkable improvements in survival rates have been reported, leading to life expectancies similar to those of the general population. However, many sexual and reproductive functions may be impaired due to erectile or ejaculatory dysfunction and semen abnormalities, characterised by low-sperm motility or viability in SCI males who have not become parents yet. Nevertheless, fatherhood is still possible through the introduction of specialised medical management, by using various medical, technical and surgical methods for sperm retrieval in combination with assisted reproductive techniques. Erectile dysfunction can be managed by the use of phosphodiesterase-5 inhibitors, intracavernosal injections, vacuum devices and penile prostheses. Semen can be obtained from the vast majority of anejaculatory men by medically assisted ejaculation through the use of penile vibratory stimulation or electroejaculation and via prostate massage or surgical procedures. Despite impaired sperm parameters, reasonable pregnancy rates similar to those in able-bodied subfertile cohorts have been reported. However, future research should focus on the optimisation of semen quality in these men and on improving natural ejaculation.