Altered Sperm Morphology Research Articles

Phenotypic continuum and poor intracytoplasmic sperm injection intracytoplasmic sperm injection prognosis in patients harboring HENMT1 variants.

Small RNAs interacting with PIWI (piRNAs) play a crucial role in regulating transposable elements and translation during spermatogenesis and are essential in male germ cell development. Disruptions in the piRNA pathway typically lead to severe spermatogenic defects and thus male infertility. The HENMT1 gene is a key player in piRNAs primary biogenesis and dysfunction of HENMT1 protein in meiotic and haploid germ cells resulted in the loss of piRNA methylation, piRNA instability, and TE de-repression. Henmt1-knockout mice exhibit a severe oligo-astheno-teratozoospermia (OAT) phenotype, whereas patients with HENMT1 variants display more severe azoospermia phenotypes, ranging from meiotic arrest to hypospermatogenesis. Through whole-exome sequencing (WES) of infertile patient cohorts, we identified two new patients with variants in the HENMT1 gene presenting spermatozoa in their ejcaulate, providing us the opportunity to study spermatozoa from these patients. Investigate the spermatozoa of two patients harboring an HENMT1 variant to determine whether or not these scarce spermatozoa could be used with assisted reproductive technologies. HENMT1 variants identified by WES were validated through Sanger sequencing. Comprehensive semen analysis was conducted, and sperm cells were subjected to transmission electron microscopy for structural examination, in situ hybridization for aneuploidy assessment, and aniline blue staining for DNA compaction status. Subsequently, we assessed their suitability for in vitro fertilization using intracytoplasmic sperm injection (IVF-ICSI). Our investigations revealed a severe OAT phenotype similar to knockout mice, revealing altered sperm concentration, mobility, morphology, aneuploidy and nuclear compaction defects. Multiple IVF-ICSI attempts were also performed, but no live births were achieved. We confirm the crucial role of HENMT1 in spermatogenesis and highlight a phenotypic continuum associated with HENMT1 variants. Unfortunately, the clinical outcome of these genetic predispositions remains unfavorable, regardless of the patient's phenotype. The presence of spermatozoa is insufficient to anticipate ICSI pregnancy success in HENMT1 patients.

Contraceptive efficacy: Determining the threshold for effective suppression based on sperm concentration, motility, and morphology.

Human spermatogenesis is a complex process that transforms spermatogonial stem cells through mitosis and meiosis to spermatozoa. Testosterone is the key regulator of the terminal stages of meiosis, adherence of spermatids to Sertoli cells, and spermiation. Follicle-stimulating hormone (FSH) may be required for early spermatogenesis and is important for maintaining normal spermatogenesis in men. Hormonal contraception suppresses FSH, luteinizing hormone, and intratesticular testosterone concentration, resulting in marked suppression of sperm output. Clinical trials using testosterone alone or testosterone plus progestin demonstrate that sustained suppression of sperm concentration to ≤1 million/mL is sufficient to prevent pregnancy in the female partner. New agents that target spermatogenesis could use this as a target for contraceptive efficacy while others that block sperm function or transport may require a lower threshold. When sperm concentrations are suppressed to such low levels, measurement of sperm motility and morphology is technically difficult and unnecessary. With current data from fertile and infertile men, it is not possible to establish a lower limit of sperm motility or percent normal morphology that equates to the prevention of conception. New compounds that decrease sperm motility or alter sperm morphology may need to demonstrate a complete absence of sperm motility or altered morphology in all spermatozoa in the ejaculate. Sperm function tests may be useful depending on the mechanism of action of each new compound. Monitoring of sperm surrogate markers to ensure effective contraception relies on laboratories experienced in semen analyses. The development of at-home tests to assess sperm parameters has progressed rapidly. Some tests have been assessed in clinical trials and approved by regulatory agencies for at-home use for fertility assessment. However, caution must be exercised in using these tests as many have not been rigorously validated against semen parameters measured in laboratories by trained technologists using standardized tests defined in the World Health Organization Semen Manual.

Comparison of Special Stains for Analysing the Morphology of Sperm: A Cross-sectional Study

Introduction: In India, male infertility constitutes 40% of infertility cases in males, which has become a serious problem in developing countries. Numerous studies and advanced techniques have been identified in assessing sperm morphology. The detection of sperm morphology is a simple and widely accepted method for determining sperm viability. It assists in selecting appropriate treatments for male infertility in assisted reproductive techniques. Infertility issues can arise in healthy males due to altered sperm morphology. Aim: To analyse the morphology of sperm using basic histopathology stains such as Haematoxylin and Eosin (H&E), Giemsa (G), Eosin-Nigrosin (EN), and Papanicolaou (Pap) stains. Materials and Methods: A cross-sectional study was conducted from April 2022 to June 2022 at the Department of Clinical Pathology, Sree Balaji Medical College and Hospital, Chennai, Tamil Nadu, India. Thirty semen samples were collected from healthy males and stained with H&E, Giemsa, Eosin-Nigrosin, and Papanicolaou stains. The results were observed and tabulated based on sperm shape, size, and motility using Kruger’s strict morphology method. A comparison was made to identify the fastest and most cost-effective method among the four stains. Descriptive statistics were used for the comparison. Results: Among the 30 semen samples, H&E and Papanicolaou stain methods were found to be rapid and cost-effective for analysing sperm morphology compared to the other stains (p-value <0.001). The findings included cases of Normozoospermia (18), Oligozoospermia (9), Necrozoospermia (1), and Teratozoospermia (2). In the Papanicolaou stained samples, the mean sperm head length (μm) was 8.92a±0.5, head width (μm) was 4.48a±0.33, head perimeter (μm) was 27.69a±1.85, head area (μm²) was 33.96a±3.74, tail length (μm) was 44.31a±2.02, sperm length (μm) was 53.24a±2.18, with no cytoplasmic droplets greater than half the size of the head and two vacuoles observed. Papanicolaou stain was the least expensive stain (9.50rs) compared to the other stains used for assessing sperm morphology. Conclusion: Papanicolaou stain is a simple and cost-effective method for analysing sperm morphology compared to other special stains. However, EN Stain is used to detect the morphology of live sperm. Sperm morphology assessment is necessary to monitor the causes of male infertility and determine appropriate treatment modalities.

Consequences of Type-2 diabetes mellitus and Malaria co-morbidity on sperm parameters in men; a case-control study in a district hospital in the Ashanti Region of Ghana.

Type-2 diabetes mellitus (T2DM) and malaria infection are highly prevalent in Africa particularly, in the Sub-Saharan Region. A greater number of people in the Ghanaian population who have T2DM are also reported to harbor malaria parasites. This study aimed to investigate the influence of T2DM & Malaria co-morbidity on sperm parameters among patients in the Ashanti Region of Ghana. This hospital-based cross-sectional analytic case-control study comprised 254 adult male study participants comprising 80 T2DM & Malaria co-morbidity, 80 T2DM only, and 94 normal controls. A blood sample (10mL) was drawn from each participant to measure FBG, HbA1c levels, Testosterone levels, Total cholesterol, and determination of Malaria parasite density. Seminal fluid was also collected from each participant for semen analysis. Sperm kinetics of the T2DM & Malaria co-morbidity group particularly; total motility, rapid progressive motility, and slow progressive motility were negatively affected compared to both T2DM only (p<0.0001) and the Normal control (p<0.0001). Normal sperm morphology was significantly affected in the co-morbidity group compared to T2DM only (p<0.0001). Sperm vitality was also statistically significantly reduced in the T2DM & Malaria co-morbidity than in T2DM only (t (64) = -8.62; p<0.001). There was a significant decline in testosterone levels in the T2DM & Malaria co-morbidity group than in the T2DM only (p<0.0001) and the control (p <0.0001). In conclusion, T2DM and malaria infection have a stronger propensity to alter sperm morphology and lower sperm motility and vitality.

P-098 Cryopreservation process deregulates the expression of pathways important for fertility in human spermatozoa

Abstract Study question Does cryopreservation impact on transcriptome of conventional frozen human spermatozoa? Summary answer The cryopreservation of human sperm alters pathways important for fertility, although the upregulation of some genes can compensate for the harmful effects of freezing. What is known already Sperm cryopreservation is a widely used procedure for storing gametes for later use, for preserving fertility in patients before gonadotoxic treatments or surgery, and for sperm donation programs. The cryopreservation technique can cause damage to sperm through induction of DNA alterations, fragmentation and oxidation, and altered motility, mitochondrial activity and morphology. Transcriptomic alterations have been reported in cryopreserved sperm from various animal species, but no experimental data are available on the effect of cryopreservation on the transcriptome-wide profile of human sperm. Study design, size, duration Semen samples were obtained from 20 normospermic men from April to May 2022. Each sample was divided in two aliquots. From one aliquot total RNA was immediately extracted. The second aliquot was slowly cryopreserved and after a week of storage in liquid nitrogen total RNA was extracted. A total of 13 paired RNA samples passed quality control and were analyzed after randomization into 4 pools, each of 6 patients. Participants/materials, setting, methods The men who participated in this study had a median age of 35.0 years (range: 29.0-46.0). RNA was extracted by miRNeasy Micro Kit (Qiagen), analyzed by High Sensitivity RNA on 2200 Tape Station system (Agilent), amplified by Ovation Pico WTA SystemV2 (Nugen), labeled and hybridized on GE 4x44K v2 microarrays (Agilent). The paired Significance Analysis of Microarray (SAM) was performed using the limma hgug4112a.db and samr packages in R/BioConductor. Main results and the role of chance The expression profiles of cryopreserved sperm significantly differed from those of fresh sperm in 219 down-regulated and 28 up-regulated unique transcripts. The gene ontology analysis disclosed that cryopreservation downregulates genes involved in sperm motility by the mitochondria function (CABS1, SPATA19) and the correct organization of the sperm midpiece and flagellum cytoskeleton (ACTL7A, AKAP4, C9ORF24, CAPZB, CCIN, IQCG, ODF2, SPATA6, SPATA6L, TBC1D21), in fertilization (ACTL7A, AKAP4, PLCZ1, PRSS37, TUBGCP3), early embryo development (AGT, CLMN, DCC, DHRS3, EGFLAM, FAM20A, FREM1, GPI, HEMGN, KRTDAP, IFT172, MICAL2, MLF1, NF2, PGRMC2, PHACTR1, POPDC3, RO60, ROBO1, RORA, SGCA, SPRR2D, TCF4, TNC, TNNI3), oxidant detoxification (TXNDC29) and DNA repair (BRIP1, ERCC6, TRIP12), calcium ion binding and homeostasis (AMY1C, ANO1, ANO2, ASGR1, CABS1, CPNE9, FREM1, KCNIP2, ITPR3, PKD2L1, PLCZ1, SELENOK, SYN3, TNNI3). Upregulated genes were enriched in pathways related to the negative regulation of DNA damage response (ALOX15B, CD74, RPL10, SNAI1, THBS1), cellular response to calcium ion (ALOX15B, FOSB, HLA-DQB1, S100A4, THBS1), regulation of transcription (CD74, FOSB, HLA-DRB1, MAMLD1, RASD1, RPL10, SNAI1, TCF15, TLE1), protein stabilization (CD74), protein ubiquitination (BAG1, DCAF6, ERCC6, HERPUD2, KLHL7, MARCHF8, NF2, PSMA6, RNF133, SERGEF, TRIP12, UBE2DNL, UBL3, UBQLN3, ZNRF3) and ubiquitin protein ligase binding (GPI, HSPA1L, PRKAR2A, STX8). Limitations, reasons for caution Data validation in a larger sample cohort and by quantitative PCR would be useful, although we have applied stringent criteria for gene selection (FDR = 0). Further research should be undertaken to experimentally test whether the length of cryostorage can have any effect on the gene expression profile of sperm. Wider implications of the findings Specific pathways are deregulated by cryopreservation, in accordance with altered sperm morphology, motility and molecular integrity reported in literature. Functional enrichment analyses also revealed gene expression changes to compensate for the sperm cryoinjury. This finding is noteworthy for safety issue of sperm banking i.e., fertility preservation, gamete donation. Trial registration number not applicable

Effects of recreational cannabis on testicular function in primary infertile men.

Male factor contributes to up to 50% of cases of couples experiencing infertility. Cannabis is one of the most commonly used recreational drugs, and its effects on the reproductive system have been largely debated in the literature. The aim of this study is to evaluate the effect of recreational cannabis use on total T (tT) levels, gonadal status, and sperm parameters in a cohort of primary infertile non-Finnish, white-European men. Data of 2074 white-European men visited for primary couple's infertility were analyzed. Lifestyle factors and cannabis use were investigated in all participants. Semen analyses were based on the 2010 World Health Organization reference criteria. Serum hormones were evaluated, and patients were subdivided based on their gonadal status. Health-significant comorbidities were scored with the Charlson Comorbidity Index (CCI). Descriptive statistics and linear regression analyses were used to test the association between cannabis use, sperm parameters, and hormonal levels. Logistic regression analyses tested potential predictors for abnormal sperm parameters and gonadal status. Of 2074, 225 (10.9%) patients reported cannabis use in their lifetime. Total Testosterone levels were lower in cannabis users compared to nonusers (p = 0.03). In a multivariable linear regression analysis, cannabis use was inversely associated with tT levels (ß = -0.372 ng/ml; p = 0.005) but not with follicle-stimulating hormone nor with luteinizing hormone levels. Conversely, at multivariable logistic regression model cannabis use was not associated with the type of hypogonadism. At multivariable linear regression analysis, cannabis use was inversely associated with sperm morphology (p = 0.007), while not with both sperm concentration and sperm motility. Similarly, at adjusted logistic regression analysis cannabis use resulted associated with teratozoospermia (p = 0.039) but not with oligo-, astheno-, and azoospermia. Infertile men using cannabis are at higher risk of having lower testosterone levels and altered sperm morphology as compared with nonusers.

The relevance of sperm morphology in male infertility.

This brief report concerns the role of human sperm morphology assessment in different fields of male infertility: basic research, genetics, assisted reproduction technologies, oxidative stress. One of the best methods in studying sperm morphology is transmission electron microscopy (TEM) that enables defining the concept of sperm pathology and classifying alterations in non-systematic and systematic. Non-systematic sperm defects affect head and tail in variable ratio, whereas the rare systematic defects are characterized by a particular anomaly that marks most sperm of an ejaculate. TEM analysis and fluorescence in situ hybridization represent outstanding methods in the study of sperm morphology and cytogenetic in patients with altered karyotype characterizing their semen quality before intracytoplasmic sperm injection. In recent years, the genetic investigations on systematic sperm defects, made extraordinary progress identifying candidate genes whose mutations induce morphological sperm anomalies. The question if sperm morphology has an impact on assisted fertilization outcome is debated. Nowadays, oxidative stress represents one of the most important causes of altered sperm morphology and function and can be analyzed from two points of view: 1) spermatozoa with cytoplasmic residue produce reactive oxygen species, 2) the pathologies with inflammatory/oxidative stress background cause morphological alterations. Finally, sperm morphology is also considered an important endpoint in in vitro experiments where toxic substances, drugs, antioxidants are tested. We think that the field of sperm morphology is far from being exhausted and needs other research. This parameter can be still considered a valuable indicator of sperm dysfunction both in basic and clinical research.

Endocrine disruption: Reproductive toxicity of glyceryl trinitrate and isosorbide mononitrate in male Wistar rats

Glyceryl trinitrate (GTN) and isosorbide mononitrate (IM) are organic nitrates which release nitric oxide upon metabolism with potential to adversely affect male reproductive function. Therefore, this study was designed to evaluate the sub-chronic effect of these organic nitrates on reproductive system in male rats. Wistar rats were separately treated with GTN and IM at 2.5, 5 and 7.5mg/kg/day by oral gavage for 45 days. At the end of treatment, serum blood samples were taken from anaesthetized rats for assessment of hormonal profile. Epididymis was removed to analyse sperm parameters. Rat testes were dissected to perform histopathological evaluation and oxidative stress biomarkers. The GTN and IM treated groups showed a significant decrease in sperm parameters (count, motility and viability) and serum testosterone in comparison to normal control group. The GTN and IM treatment also altered sperm morphology such as bent tail and head deformities as compared to control. A significant decrease in catalase activity and, increase in nitric oxide and malondialdehyde were observed in high dose drug treated groups. Moreover, a significant increase in follicle stimulating hormone and decrease in testosterone levels were evident in all drug treated groups. The level of luteinizing hormone was raised in rats treated with medium doses of drugs while it decreased at the highest dose of both drugs. Histological study showed vacuolization and degeneration of seminiferous tubules. It is concluded that GTN and IM treatment adversely affected the male reproductive function by altering sperm parameters and disrupting the reproductive hormone profile which may be attributed to the increased level of nitric oxide and oxidative stress.

A Perspective on Reproductive Toxicity of Metallic Nanomaterials.

Nanotechnological tools have been greatly exploited in all possible fields. However, advancement of nanotechnology has raised concern about their adverse effects on human and environment. These deleterious effects cannot be ignored and need to be explored due to safety purpose. Several recent studies have demonstrated possible health hazard of nanoparticles on organism. Moreover, studies showed that toxicity of metallic nanomaterial could also lead to reproductive toxicity. Various deleterious effects have demonstrated decreased sperm motility, increased abnormal spermatozoa, altered sperm count, and altered sperm morphology. Morphological and ultrastructural changes also have been reported due to the accumulation of these nanomaterials in reproductive organs. Nonetheless, studies also suggest crossing of metallic nanoparticles through blood testes barrier and generation of oxidative stress which plays major role in reproductive toxicity. In the present study, we have incorporated updated information by gathering all available literature about various metallic nanomaterials and risk related to reproductive system.

Effects of Coenzyme Q10 and Diamond Nanoparticles on Ischemia-Reperfusion-Induced Testicular Damages in Rats

Background:Ischemia-reperfusion (I/R) induced by testicular torsion can damage the testicles. In the present study, we assessed the effects of coenzyme Q10 (CoQ10) and diamond nanoparticles on sperm parameters in I/R testes in rats.Materials and Methods:Forty-eight Wistar adult male rats were divided into eight groups: healthy control (Ch), diamond nanoparticle healthy control group (Ch+Dia), CoQ10 healthy control group (Ch+Q10), diamond nanoparticles+CoQ10 healthy control group (Ch+Q10+Dia), torsion/detorsion group (Ct), the Ct group that received diamond nanoparticles (Ct+Dia), the Ct group that received CoQ10 (Ct+Q10), and Ct group that received diamond nanoparticles and CoQ10 (Ct+Q10+Dia). The rats were euthanized, and we collected the semen from the epididymal tissues to evaluate sperm viability, motility, concentration, and morphology parameters.Results:The I/R of the testicles significantly reduced sperm concentration, motility, viability, and altered sperm morphology in the rats. However, the administration of CoQ10 significantly improved sperm parameters in the rats with testicular I/R. Diamond nanoparticles decreased the sperm parameters; however, simultaneous administration of diamond nanoparticles and CoQ10 led to improved sperm parameters. Conclusion:CoQ10 potentially appeared to have protective effects against the long-term side-effects of I/R in testes in rats. Co-administration of diamond nanoparticles with CoQ10 significantly improved sperm parameters and greatly reduced the negative effects of diamond nanoparticles alone. Therefore, green synthesis of nanoparticles with the use of antioxidants such as CoQ10 is recommended.

Effects of Coenzyme Q10 and Diamond Nanoparticles on Ischemia-Reperfusion-Induced Testicular Damages in Rats

Background: Ischemia-reperfusion (I/R) induced by testicular torsion can damage the testicles. In the present study, we assessed the effects of coenzyme Q10 (CoQ10) and diamond nanoparticles on sperm parameters in I/R testes in rats. Materials and Methods: Forty-eight Wistar adult male rats were divided into eight groups: healthy control (Ch), diamond nanoparticle healthy control group (Ch+Dia), CoQ10 healthy control group (Ch+Q10), diamond nanoparticles+CoQ10 healthy control group (Ch+Q10+Dia), torsion/detorsion group (Ct), the Ct group that received diamond nanoparticles (Ct+Dia), the Ct group that received CoQ10 (Ct+Q10), and Ct group that received diamond nanoparticles and CoQ10 (Ct+Q10+Dia). The rats were euthanized, and we collected the semen from the epididymal tissues to evaluate sperm viability, motility, concentration, and morphology parameters. Results: The I/R of the testicles significantly reduced sperm concentration, motility, viability, and altered sperm morphology in the rats. However, the administration of CoQ10 significantly improved sperm parameters in the rats with testicular I/R. Diamond nanoparticles decreased the sperm parameters; however, simultaneous administration of diamond nanoparticles and CoQ10 led to improved sperm parameters. Conclusion: CoQ10 potentially appeared to have protective effects against the long-term side-effects of I/R in testes in rats. Co-administration of diamond nanoparticles with CoQ10 significantly improved sperm parameters and greatly reduced the negative effects of diamond nanoparticles alone. Therefore, green synthesis of nanoparticles with the use of antioxidants such as CoQ10 is recommended. [GMJ.2021;10:e2029]

Bisphenol A-induced Alterations in Different Stages of Spermatogenesis and Systemic Toxicity in Albino Mice (Mus musculus).

Background.Bisphenol A (BPA) is known to alter sperm morphology, but information is limited on the most susceptible stage(s) of spermatogenesis, especially in mice.Objectives.This study investigated the reproductive, biochemical, and hematological changes caused by exposure to BPA in male albino mice. The genotoxicity of BPA to the six stages of spermatogenesis in mice was determined.Methods.Mice were exposed orally to BPA at 0.5, 1.0, 2.0, and 5.0 mg/kg bw doses for 5 days and assessed for sperm morphology after 35 days. Based on the result, the second group of mice was exposed to BPA at 1.0 mg/kg bw dose for 5 days, their spermatozoa were assessed for sperm morphology based on BPA exposure at the 6 maturation stages of spermatogenesis: spermatozoa, elongating spermatids, round spermatids, secondary spermatocytes, primary spermatocytes, and spermatogonia. Biochemical and hematological analyses of the blood of exposed mice were also carried out.Results.The results showed that BPA induced concentration-dependent, significantly (p<0.05) increased sperm cell abnormalities at three of the four concentrations tested, with the exception of 0.5 mg/kg bw, in comparison with the negative control. The highest frequency of sperm aberrations was induced in spermatozoa exposed to BPA while at the primary spermatocytes. The order of induced sperm abnormality at the different stages of exposure was: primary spermatocytes > elongating spermatids > spermatozoa > spermatogonia > round spermatids > secondary spermatocytes. The results of the biochemical analysis showed significantly (p<0.05) increased serum urea, creatinine, and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities with a concomitant decrease in total protein content at the various stages of spermatogenesis. In addition, the results for hematological parameters showed several significant (p<0.05) modulations in mice exposed to BPA.Conclusions.These data showed that BPA is most toxic to primary spermatocytes and alterations of biochemical and hematological parameters might be the mechanisms of induced toxicity.Ethics Approval.The Research Ethics Committee, Federal University of Technology, Akure approved the study protocols.Competing Interests.The authors declare no competing financial interests

Circular RNAs protect male fertility

Molecular Genetics Eukaryotes make thousands of circular RNAs (circRNAs) by noncanonical RNA splicing. The functions of most are mysterious, but many sequester microRNAs or RNA-binding proteins. Gao et al. examined the functions of circRNAs from the conserved reproductive gene BOULE (circBoule RNAs). Loss of these RNAs reduced male fertility in fruit flies and mice under heat stress, with reduced sperm levels and altered sperm morphology. During spermatogenesis, circBoule RNAs interact with heat shock proteins and control their levels by promoting their ubiquitination. circBoule RNA interaction with heat shock proteins is conserved in human sperm, and low circBoule RNA levels correlate with low sperm motility. These findings reveal conserved molecular and physiological functions of circBoule RNAs over some 600 million years of evolution. Sci. Adv. 10.1126/sciadv.abb7426 (2020).

Protective role of glutamine against cadmium-induced testicular dysfunction in Wistar rats: Involvement of G6PD activity

BackgroundEndocrine disruptor such as cadmium has been widely reported to cause testicular toxicity, which contributes to recent decline in male fertility worldwide. Glutamine, the most abundant amino acid in the body has been demonstrated to exert protective effects in cellular toxicity. However, its role in testicular toxicity is unknown. The present study is therefore aimed at investigating the effects of glutamine supplementation on cadmium-induced testicular toxicity, and the possible involvement of glucose-6-phosphate dehydrogenase (G6PD) activity. Materials and methodMale Wistar rats weighing 160–190 g were allotted into 4 groups (n = 5/group): The groups received vehicle (distilled water; p.o.), glutamine (1gkg−1; p.o.), cadmium chloride (5mgkg−1p.o.) and Cadmium chloride plus glutamine respectively, daily for 30 days. Biochemical and histological analyses were performed with appropriate method. ResultsAdministration of cadmium significantly decreased body weight, sperm count, motility and viability, as well as altered sperm morphology and progressivity. Cadmium also caused atrophy of the seminiferous tubule in addition to disrupted testicular architecture, lumen, Sertoli cells and spermatogonia. Similarly, serum and testicular aspartate transaminase, and malondialdehyde significantly increased, and G6PD, glutathione, nicotinamide adenine dinucleotide phosphate and nitric oxide significantly decreased with corresponding decrease in follicle stimulating hormone, luteinizing hormone and testosterone in cadmium-treated animals compared with control groups. However, supplementation with glutamine attenuated these alterations. ConclusionThe present study demonstrates that cadmium induces testicular dysfunction that is attributable to defective G6PD and accompanied by increased lipid peroxidation and impaired NO-dependent endothelial function. Interestingly, glutamine supplementation ameliorates cadmium-induced testicular dysfunction through enhancement of G6PD activity.

Concentrated ambient PM2.5exposure affects mice sperm quality and testosterone biosynthesis

BackgroundStudies suggested that PM2.5 exposure could lead to adverse reproductive effects on male animals. However, the underlying mechanism is still not clear. Besides, animals in the majority of previous studies were exposed to PM2.5 through intratracheal instillation which should be improved. In addition, limited amount of research has been conducted in China where the PM2.5 concentration is higher and the PM2.5 components are different. The aim of this work is to explore the effects of concentrated ambient PM2.5 (CAP) on mice sperm quality and testosterone biosynthesis.MethodsA total of 12 male C57BL/6 mice were exposed to filtered air (FA) or CAP for 125 days using the Shanghai Meteorological and Environmental Animal Exposure System. The mice sperm concentration, sperm motility, DNA fragmentation index, high DNA stainability and plasma testosterone were analyzed. Testicular histology and sperm morphology were observed through optical microscope. Testosterone biosynthesis related gene expressions were analyzed using real-time PCR, including cytochrome P450 CHOL side-chain cleavage enzyme (P450scc), steroidogenic acute regulatory protein (StAR), 3β-hydroxysteroid dehydrogenase (3β HSD), 17β-hydroxysteroid dehydrogenase, cytochrome P450 aromatase (P450arom), estrogen receptor (ER), androgen receptor (AR) and follicle stimulating hormone receptor (FSHR).ResultsExposure to CAP resulted in disturbance of various stages of spermatogenesis and significant higher percentage of abnormal sperm (FA vs. CAP: 24.37% vs. 44.83%) in mice testis. CAP exposure significantly decreased sperm concentration (43.00 × 106 vs. 25.33 × 106) and motility (PR: 63.58% vs. 55.15%; PR + NP: 84.00% vs. 77.08%) in epididymis. Plasma testosterone concentration were significantly declined (0.28 ng/ml vs. 0.69 ng/ml) under CAP exposure. Notably, the levels of testosterone biosynthesis related genes, StAR, P450scc, P450arom, ER and FSHR were significantly decreased with CAP exposure.ConclusionConcentrated ambient PM2.5 exposure altered mice sperm concentration, motility and morphology, which might be mediated primarily by the decline in testosterone concentration and testosterone biosynthesis process.

Effects of in vitro exposure of mercury on sperm quality and fertility of tropical fish Cyprinus carpio L.

Mercury is a widespread aquatic pollutant that adversely affects the reproductive system of male fish. Although the effects of mercuric chloride (HgCl2) on the testicular structure, the sperm count and altered sperm morphology of fish have been investigated, the effects on sperm quality and fertilization are unknown. Therefore, the aim of this study was to investigate the effects of HgCl2 exposure in different concentrations (0; 0.5; 1; 2.5; 5 ppm) on sperm parameters and fertility of male Cyprinus carpio. Sperm quality parameters, including mass and individual time of sperm motility (s), and viability (%) were measured using digital inverted microscopy. The fertilization (%) was measured by counting the number of fertilized eggs. Integrity or DNA fragmentation (%) was measured by Acridine orange test (AOT) using fluorescence microscopy. The change of sperm membrane surface was examined using scanning electron microscopy (SEM). The results showed that the in vitro exposure of mercury could significantly decrease some parameters of fish sperm qualities, i.e. decreased the time for mass and individual motility, viability, DNA fragmentation, and fertilization ability (P < 0.05) and significantly increase the malondialdehyde levels of sperm (P < 0.05). In addition, Hg exposure altered the morphological structure of the sperm head and interfered with the development of embryos in fish eggs.

Deficiency of fibroblast growth factor 2 (FGF-2) leads to abnormal spermatogenesis and altered sperm physiology.

In previous studies, we described the presence of fibroblast growth factor 2 (FGF-2) and its receptors (FGFRs) in human testis and sperm, which are involved in spermatogenesis and in motility regulation. The aim of the present study was to analyze the role of FGF-2 in the maintenance of sperm physiology using FGF-2 knockout (KO) mice. Our results showed that in wild-type (WT) animals, FGF-2 is expressed in germ cells of the seminiferous epithelium, in epithelial cells of the epididymis, and in the flagellum and acrosomal region of epididymal sperm. In the FGF-2 KO mice, we found alterations in spermatogenesis kinetics, higher numbers of spermatids per testis, and enhanced daily sperm production compared with the WT males. No difference in the percentage of sperm motility was detected, but a significant increase in sperm concentration and in sperm head abnormalities was observed in FGF-2 KO animals. Sperm from KO mice depicted reduced phosphorylation on tyrosine residues (a phenomenon that was associated with sperm capacitation) and increased acrosomal loss after incubation under capacitating conditions. However, the FGF-2 KO males displayed no apparent fertility defects, since their mating with WT females showed no differences in the time to delivery, litter size, and pup weight in comparison with WT males. Overall, our findings suggest that FGF-2 exerts a role in mammalian spermatogenesis and that the lack of FGF-2 leads to dysregulated sperm production and altered sperm morphology and function. FGF-2-deficient mice constitute a model for the study of the complex mechanisms underlying mammalian spermatogenesis.

The effects of type I collagenase on the degelification of chimpanzee (Pan troglodytes) semen plug and sperm quality

BackgroundSemen from the chimpanzee species becomes a colloidal solid after ejaculation. The formation of this copulatory plug is believed to prevent additional spermatozoa of subsequent mating events from accessing the ova. However, this naturally preserved strategy hampers the processes for sperm preparation. In this study, we investigated whether collagenase can be used to degelify the semen plug and accelerate the semen liquefaction process in zoo captive chimpanzee species (Pan troglodytes).ResultsWe showed that incubation of chimpanzee ejaculates with 0.1% type I collagenase efficiently and significantly (p < 0.05) releases 2.7-fold more spermatozoa from the coagulated ejaculates, and this degelification process did not alter sperm morphology or viability; nor did it stimulate spontaneous capacitation or an acrosome reaction as assessed by tyrosine phosphorylation and peanut agglutinin stains; moreover, based on computer assisted sperm analysis assay, motility-related parameters remained similar to those of untreated spermatozoa. When collagenase effects were evaluated on cryopreserved sperm samples, we observed post collagenase treatment in which 2.5% glycerol, as a cryoprotectant, preserved sperm acrosome integrity better than 7.8%; however, 7.8% glycerol, as a cryoprotectant, maintained sperm motility better than that of 2.5% glycerol.ConclusionsOur results demonstrated for the first time that type I collagenase can be used to obtain a significantly higher number of spermatozoa from colloid chimpanzee semen ejaculate without affecting the physiological properties of spermatozoa, and these results are critical for the subsequent gamete development. Our results would benefit sperm preparation processes and cryopreservation efficiency per ejaculate, as more unaffected spermatozoa can be released from the semen plug within a shorter period of time. These results would also benefit the genetic diversity of the chimpanzee species, using sperm cells from less dominant individuals, and for achieving better pregnancy success in primates with significantly higher amounts of sperm for artificial insemination.

Paternal developmental TCDD exposure disrupts placental function in a subsequent adult pregnancy in a murine model

We previously established a murine model to explore the adult consequences of developmental TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) exposure. Using this model, we demonstrated that adult male offspring (F1) of toxicant exposed dams exhibit testicular inflammation, reduced sperm count, altered sperm morphology and subfertility. Control partners of F1 males that were able to become pregnant exhibit placental inflammation and an increased risk of spontaneous preterm birth. Our studies also demonstrated reduced placental and pup weight in pregnancies arising from F1 males compared to controls, suggesting paternal toxicant exposure is associated with placental dysfunction.

Sertoli Cells Are Susceptible to ZIKV Infection in Mouse Testis.

Flaviviruses including Dengue virus (DENV), Yellow fever virus (YFV), West Nile virus (WNV), and Japanese encephalitis virus (JEV) are global health problems that caused several serious diseases such as fever, hemorrhagic fever, and encephalitis in the past century. Recently, Zika virus (ZIKV) which spreads from Asia to American and causes millions of infections emerges as a new dangerous member of the genus of Flavivirus. Unlike other well-known flaviviruses, ZIKV can be transmitted sexually and infect testes in murine models. Its impacts on sperm functions, and the exact susceptible cells, however, are not entirely clear. To investigate these issues, we infected interferon α/β and γ receptors deficient AG6 mice with ZIKV and examined the outcomes of infection using an assortment of physiological, histopathological, immunological, and virological techniques. We found that infected mice displayed signs of reproductive system disorder, altered androgen levels in serum, and high viral load in semen and testes. Additionally, histopathological examinations revealed marked atrophy of seminiferous tubules and significant reduction in lumen size. Notably, these were accompanied by positive staining of ZIKV antigens on sertoli cells, detection of viral particles and vacuole changes within cytoplasm of sertoli cells. The susceptibility of sertoli cells to ZIKV was further validated in vitro study using cell lines. Importantly, the disruption of tight junctions within testis and altered sperm morphology were also observed in ZIKV infected mice. It is well-known that tight junctions formed by adjacent sertoli cells are major component of blood testis barrier, which plays important roles in maintenance of microenvironment for spermagenesis in testis. Taken together, these results demonstrate that sertoli cells are susceptible to ZIKV infection, which results in the disruption of tight junctions in testis and causes abnormal spermatogenesis in mice. These results also imply that long-term impact of ZIKV infection on human male reproductive system requires close monitoring.