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Bouloorchi Tabalvandani M, Saeidpour Z, Habibi Z, Javadizadeh S, Firoozabadi SA, Badieirostami M. Microfluidics as an emerging paradigm for assisted reproductive technology: A sperm separation perspective. Biomed Microdevices 2024; 26:23. [PMID: 38652182 DOI: 10.1007/s10544-024-00705-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2024] [Indexed: 04/25/2024]
Abstract
Millions of people are subject to infertility worldwide and one in every six people, regardless of gender, experiences infertility at some period in their life, according to the World Health Organization. Assisted reproductive technologies are defined as a set of procedures that can address the infertility issue among couples, culminating in the alleviation of the condition. However, the costly conventional procedures of assisted reproduction and the inherent vagaries of the processes involved represent a setback for its successful implementation. Microfluidics, an emerging tool for processing low-volume samples, have recently started to play a role in infertility diagnosis and treatment. Given its host of benefits, including manipulating cells at the microscale, repeatability, automation, and superior biocompatibility, microfluidics have been adopted for various procedures in assisted reproduction, ranging from sperm sorting and analysis to more advanced processes such as IVF-on-a-chip. In this review, we try to adopt a more holistic approach and cover different uses of microfluidics for a variety of applications, specifically aimed at sperm separation and analysis. We present various sperm separation microfluidic techniques, categorized as natural and non-natural methods. A few of the recent developments in on-chip fertilization are also discussed.
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Affiliation(s)
| | - Zahra Saeidpour
- MEMS Lab, School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, 1439957131, Iran
| | - Zahra Habibi
- MEMS Lab, School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, 1439957131, Iran
| | - Saeed Javadizadeh
- MEMS Lab, School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, 1439957131, Iran
| | - Seyed Ahmadreza Firoozabadi
- MEMS Lab, School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, 1439957131, Iran
| | - Majid Badieirostami
- MEMS Lab, School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, 1439957131, Iran.
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Kim J, Min H, Ko S, Shim YH. Depletion of gipc-1 and gipc-2 causes infertility in Caenorhabditis elegans by reducing sperm motility. Biochem Biophys Res Commun 2020; 534:219-225. [PMID: 33280819 DOI: 10.1016/j.bbrc.2020.11.108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 11/24/2020] [Indexed: 11/24/2022]
Abstract
The G-protein signaling pathway plays a key role in multiple cellular processes and is well conserved in eukaryotes. Although GIPC (G-protein α subunit interacting protein (GAIP)-interacting protein, C terminus) has been studied in several model organisms, little is known about its role in Caenorhabditis elegans. In the present study, we investigated the roles of gipc-1 and gipc-2 in C. elegans. We observed that they were exclusively expressed in sperm throughout the development and that gipc-1; gipc-2 double mutants were infertile. Further examination of sperm development in gipc-1; gipc-2 mutants revealed defective sperm activation and abnormal pseudopod extension that resulted in reduced sperm motility. Moreover, major sperm protein (MSP) was abnormally segregated between spermatids and residual bodies in gipc-1; gipc-2 mutants. Our findings indicate that gipc-1 and gipc-2 are required for the proper pseudopod extension of sperm during the terminal differentiation of spermatids. During this process, the segregation of MSP into spermatids is important for ensuring normal sperm motility during fertilization.
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Affiliation(s)
- Jaehoon Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Hyemin Min
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Sunhee Ko
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Yhong-Hee Shim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea.
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E Silva PV, Borges CDS, Rosa JDL, Pacheco TL, Figueiredo TM, Leite GAA, Guerra MT, Anselmo-Franci JA, Klinefelter GR, Kempinas WDG. Effects of isolated or combined exposure to sibutramine and rosuvastatin on reproductive parameters of adult male rats. J Appl Toxicol 2020; 40:947-964. [PMID: 32072669 DOI: 10.1002/jat.3955] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 01/13/2020] [Accepted: 01/26/2020] [Indexed: 01/23/2023]
Abstract
Many obese patients are exposed to hypolipidemic and serotonin-norepinephrine reuptake inhibitor (SNRI) drugs. Statins are one of the most marketed drugs in the world to treat dyslipidemia, while sibutramine, a SNRI drug, is prescribed in some countries to treat obesity and is detected as an additive in many adulterated weight loss supplements marketed worldwide. Previous studies reported adverse effects of isolated exposure to these drugs on male rat reproductive parameters. In the present work, we further investigated male reproductive toxicity of these drugs, administered in isolation or combination in adult rats for a longer period of treatment. Adult male rats (90 days) were treated (gavage) for 70 days with saline and dimethyl sulfoxide (control), sibutramine (10 mg/kg), rosuvastatin (5 mg/kg), or rosuvastatin combined with sibutramine. Sibutramine alone or with rosuvastatin, promoted a reduction in food intake and body weight gain, weight of the epididymis, ventral prostate and seminal vesicle; as well as decreased sperm reserves and transit time through the epididymis; androgen depletion; and increased index of cytoplasmic droplet. The rosuvastatin-treated group showed reduced frequency of ejaculation. Exposure to this drug alone or combined with sibutramine impaired epididymal morphology. Co-exposed rats had altered epididymal morphometry, and seminal vesicle and testis weights. The rats also showed decreased fertility after natural mating and a trend toward a delay in ejaculation, suggesting a small synergistic effect of these drugs. Given the greater reproductive efficiency of rodents, the results obtained in the present study raise concern regarding possible fertility impairment in men taking statins and SNRI drugs.
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Affiliation(s)
- Patrícia Villela E Silva
- Department of Morphology, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, SP, Brazil
| | - Cibele Dos Santos Borges
- Department of Morphology, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, SP, Brazil
| | - Josiane de Lima Rosa
- Department of Morphology, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, SP, Brazil
| | - Tainá Louise Pacheco
- Department of Morphology, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, SP, Brazil
| | - Thamiris Moreira Figueiredo
- Department of Morphology, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, SP, Brazil
| | - Gabriel Adan Araújo Leite
- Graduate Program in Cell and Structural Biology, Institute of Biology, State University of Campinas - UNICAMP, Campinas, SP, Brazil
| | - Marina Trevizan Guerra
- Department of Morphology, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, SP, Brazil
| | - Janete Aparecida Anselmo-Franci
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo - USP, Ribeirão Preto, SP, Brazil
| | - Gary Robert Klinefelter
- Reproductive Toxicity Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, North Carolina, USA
| | - Wilma De Grava Kempinas
- Department of Morphology, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, SP, Brazil
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Pan D, Feng D, Ding H, Zheng X, Ma Z, Yang B, Xie M. Effects of bisphenol A exposure on DNA integrity and protamination of mouse spermatozoa. Andrology 2019; 8:486-496. [PMID: 31489793 DOI: 10.1111/andr.12694] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 07/04/2019] [Accepted: 07/16/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND Bisphenol A is widely used in the manufacture of polycarbonate plastics and has caused increasing concern over its potential adverse impacts on spermatogenesis. However, the effect of bisphenol A on spermiogenesis is yet to be explored. OBJECTIVES To evaluate whether bisphenol A has adverse effects on DNA integrity and protamination of spermatogenic cell. MATERIALS AND METHODS Newborn male mice were subcutaneously injected with bisphenol A (0.1, 5 mg/kg body weight, n = 15) or coin oil (control group, n = 20) daily from post-natal day 1 until 35. At post-natal day 70, epididymis caudal spermatozoa and testes were collected. Sperm count, sperm motility, and sperm morphology were analyzed. The sperm chromatin structure assay was performed to examine the sperm DNA fragmentation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method was used to assess apoptosis of spermatogenic cells. The ultrastructural features of testicular sections were examined under a transmission electron microscope. Western blot and RT-PCR were used to detect the expression levels of transition protein (Tnp) 1 and Tnp2, protamine (Prm) 1 and Prm2 protein, and mRNA in mice testes. RESULTS Bisphenol A significantly reduced sperm counts, impaired sperm motility, and increased the percentage of malformed spermatozoa. Poor sperm chromatin integrity and increased TUNEL-positive spermatogenic cells were also observed in mice exposed to bisphenol A. Ultrastructural analysis of testes showed that bisphenol A exposure caused incomplete chromatin condensation, retention of residual cytoplasm, and abnormal acrosome formation. In addition, the relative expression levels of Tnp2 and Prm2 in mice testes decreased significantly in bisphenol A groups. DISCUSSION AND CONCLUSION Our findings identified that neonatal bisphenol A exposure may negatively contribute to the sperm quality in adult mice. Mechanistically, we showed that bisphenol A reduced sperm chromatin integrity along with increased DNA damage, which may be due to poor protamination of spermatozoa.
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Affiliation(s)
- D Pan
- School of Bioscience and Technology, Weifang Medical University, Weifang, China.,State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, Shanghai, China
| | - D Feng
- Department of Obstetrics, Affiliated Hospital of Weifang Medical University, Weifang, China
| | - H Ding
- School of Bioscience and Technology, Weifang Medical University, Weifang, China
| | - X Zheng
- School of Bioscience and Technology, Weifang Medical University, Weifang, China
| | - Z Ma
- School of Bioscience and Technology, Weifang Medical University, Weifang, China
| | - B Yang
- School of Bioscience and Technology, Weifang Medical University, Weifang, China
| | - M Xie
- School of Bioscience and Technology, Weifang Medical University, Weifang, China
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Hu J, Cheng S, Wang H, Li X, Liu S, Wu M, Liu Y, Wang X. Distinct roles of two myosins in C. elegans spermatid differentiation. PLoS Biol 2019; 17:e3000211. [PMID: 30990821 PMCID: PMC6485759 DOI: 10.1371/journal.pbio.3000211] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/26/2019] [Accepted: 03/20/2019] [Indexed: 12/24/2022] Open
Abstract
During spermatogenesis, interconnected haploid spermatids segregate undesired cellular contents into residual bodies (RBs) before detaching from RBs. It is unclear how this differentiation process is controlled to produce individual spermatids or motile spermatozoa. Here, we developed a live imaging system to visualize and investigate this process in C. elegans. We found that non-muscle myosin 2 (NMY-2)/myosin II drives incomplete cytokinesis to generate connected haploid spermatids, which are then polarized to segregate undesired cellular contents into RBs under the control of myosin II and myosin VI. NMY-2/myosin II extends from the pseudo-cleavage furrow formed between two haploid spermatids to the spermatid poles, thus promoting RB expansion. In the meantime, defective spermatogenesis 15 (SPE-15)/myosin VI migrates from spermatids towards the expanding RB to promote spermatid budding. Loss of myosin II or myosin VI causes distinct cytoplasm segregation defects, while loss of both myosins completely blocks RB formation. We found that the final separation of spermatids from RBs is achieved through myosin VI-mediated cytokinesis, while myosin II is dispensable at this step. SPE-15/myosin VI and F-actin form a detergent-resistant actomyosin VI ring that undergoes continuous contraction to promote membrane constriction between spermatid and RB. We further identified that RGS-GAIP-interacting protein C terminus (GIPC)-1 and GIPC-2 cooperate with myosin VI to regulate contractile ring formation and spermatid release. Our study reveals distinct roles of myosin II and myosin VI in spermatid differentiation and uncovers a novel myosin VI-mediated cytokinesis process that controls spermatid release.
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Affiliation(s)
- Junyan Hu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shiya Cheng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Haibin Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Xin Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Sun Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Mengmeng Wu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Yubing Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Xiaochen Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- * E-mail:
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6
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Kumar N, Singh AK. Reactive oxygen species in seminal plasma as a cause of male infertility. J Gynecol Obstet Hum Reprod 2018; 47:565-572. [DOI: 10.1016/j.jogoh.2018.06.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 06/13/2018] [Accepted: 06/21/2018] [Indexed: 12/31/2022]
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Zhu WJ. Transmission electron microscopy analysis of the origin and incidence of sperm intranuclear cytoplasmic retention in fertile and teratozoospermia men. Andrology 2018; 6:317-324. [PMID: 29457364 DOI: 10.1111/andr.12469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 12/31/2017] [Accepted: 01/02/2018] [Indexed: 11/27/2022]
Abstract
The human sperm nucleus contains cytoplasm. However, the origin and incidence of human sperm intranuclear cytoplasmic retention (INCR) remain unknown. The objectives of this study were to observe the morphological origin of INCR within the seminiferous epithelium and investigate the incidence of INCR in fertile and teratozoospermia men using transmission electron microscopy (TEM). By TEM, INCR initially appeared in elongating round spermatid nuclei and varied in size, number, shape, content, location and distribution within sperm nuclei. The teratozoospermia group (n = 16) demonstrated a higher incidence of INCR than did the fertile group (n = 16) (17.6 ± 5.2% vs. 9.7 ± 3.4%; p = 0.000). In the fertile group, no correlations were found between the incidence of INCR and abnormal sperm morphology, nuclear vacuole, acrosome integrity, motility or concentration (p > 0.05). However, the incidence of INCR exhibited a positive relationship with sperm abnormal morphology in the teratozoospermia group (r = 0.616, p = 0.011). These results demonstrate that INCR occurs in the early process of spermatogenesis and is an alteration found in the nucleus. Spermatozoa from teratozoospermia men contained more INCRs than those from fertile males. More attention should be paid to the possibility of spermatozoa containing INCR when using spermatozoa with abnormal head morphology for clinical or diagnostic purposes.
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Affiliation(s)
- W-J Zhu
- Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangzhou, China
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Pathak P, Chandrashekar A, Hakky TS, Pastuszak AW. Varicocele management in the era of in vitro fertilization/intracytoplasmic sperm injection. Asian J Androl 2017; 18:343-8. [PMID: 27030086 PMCID: PMC4854076 DOI: 10.4103/1008-682x.178482] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Varicocele is the most common surgically treatable cause of male infertility, and often results in alterations in semen parameters, sperm DNA damage, and changes to the seminal milieu. Varicocele repair can result in improvement in these parameters in the majority of men with clinical varicocele; data supporting repair in men with subclinical varicocele are less definitive. In couples seeking fertility using assisted reproductive technologies (ARTs), varicocele repair may offer improvement in semen parameters and sperm health that can increase the likelihood of successful fertilization using techniques such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), or may decrease the level of ART needed to achieve successful pregnancy. Male infertility is an indicator of general male health, and evaluation of the infertile male with an eye toward future health can facilitate optimal screening and treatment of these men. Furthermore, varicocele may represent a progressive lesion, offering an argument for its repair, although this is currently unclear.
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Affiliation(s)
| | | | | | - Alexander W Pastuszak
- Scott Department of Urology, Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX; Scott Department of Urology, Baylor College of Medicine, Houston, TX, USA
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Abstract
Testicular varicocele, a dilation of the veins of the pampiniform plexus thought to increase testicular temperature via venous congestion, is commonly associated with male infertility. Significant study has clarified the negative impact of varicocele on semen parameters and more recent work has shed light on its detrimental effects on the molecular and ultrastructural features of sperm and the testicular microenvironment, as well as more clearly defined the positive impacts of treatment on couples’ fertility. The relationship between varicocele and testicular endocrine function, while known for some time based on histologic evaluation, has become more apparent in the clinical setting with a growing link between varicocele and hypogonadism. Finally, in the pediatric setting, while future study will clarify the impact of varicocele on fertility and testicular function, recent work supports a parallel effect of varicocele in adolescents and adults, suggesting a re-evaluation of current treatment approaches in light of the progressive nature of the condition and potential increased risk of future disease.
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Affiliation(s)
- Alexander W Pastuszak
- Center for Reproductive Medicine; Scott Department of Urology, Baylor College of Medicine, Houston, TX, USA
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Steinhauer J. Separating from the pack: Molecular mechanisms of Drosophila spermatid individualization. SPERMATOGENESIS 2015; 5:e1041345. [PMID: 26413413 PMCID: PMC4581072 DOI: 10.1080/21565562.2015.1041345] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 03/26/2015] [Accepted: 03/26/2015] [Indexed: 12/18/2022]
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Lehtihet M, Hylander B. Semen quality in men with chronic kidney disease and its correlation with chronic kidney disease stages. Andrologia 2014; 47:1103-8. [PMID: 25487067 DOI: 10.1111/and.12388] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2014] [Indexed: 12/27/2022] Open
Abstract
The aim of this study was to assess whether chronic kidney disease (CKD) has any impact on semen quality parameters in men with CKD stage 1-5. Results were collected from 66 men with different CKD stages (age 18-50 years). Age and BMI (body mass index) were recorded for each male. Higher CKD stage had a significant negative linear trend on semen volume (P < 0.05), progressive motility (P < 0.01), nonprogressive motility (P < 0.001), sperm concentration (P < 0.01), total sperm number (P < 0.01), cytoplasmic droplets (P < 0.01), teratozoospermia index (P < 0.05) and accessory gland markers, α-glucosidase activity (P < 0.05), zinc (P < 0.01) and fructose (P < 0.01). BMI per se had no significant effect on semen volume, sperm number, sperm concentration, morphology, α-glucosidase activity, fructose concentration or zinc level. A significant negative correlation between BMI and sexual-hormone-binding globulin (SHBG) (P < 0.01) was observed but not with other sex hormones. Age per se was related to a significant decrease of sperm concentration (P < 0.05), normal forms (P < 0.01) and testosterone level (P < 0.05). Our results indicate that CKD stage per se is a factor determining the number of spermatozoa available in the epididymis for ejaculation, in part independent of age-related decrease of testosterone level and BMI.
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Affiliation(s)
- M Lehtihet
- Department of Medicine, Karolinska Institute and Centre for Andrology and Sexual Medicine, Karolinska University Hospital, Huddinge, Sweden
| | - B Hylander
- Department of Nephrology, Karolinska Institute and Karolinska University Hospital Solna, Stockholm, Sweden
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12
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Beracochea F, Gil J, Sestelo A, Garde J, Santiago-Moreno J, Fumagalli F, Ungerfeld R. Sperm characterization and identification of sperm sub-populations in ejaculates from pampas deer (Ozotoceros bezoarticus). Anim Reprod Sci 2014; 149:224-30. [DOI: 10.1016/j.anireprosci.2014.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 07/08/2014] [Accepted: 07/09/2014] [Indexed: 11/29/2022]
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The role of E3 ligases in the ubiquitin-dependent regulation of spermatogenesis. Semin Cell Dev Biol 2014; 30:27-35. [PMID: 24632385 DOI: 10.1016/j.semcdb.2014.03.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 03/02/2014] [Indexed: 12/23/2022]
Abstract
The ubiquitination of proteins is a post-translational modification that was first described as a means to target misfolded or unwanted proteins for degradation by the proteasome. It is now appreciated that the ubiquitination of proteins also serves as a mechanism to modify protein function and cellular functions such as protein trafficking, cell signaling, DNA repair, chromatin modifications, cell-cycle progression and cell death. The ubiquitination of proteins occurs through the hierarchal transfer of ubiquitin from an E1 ubiquitin-activating enzyme to an E2 ubiquitin-conjugating enzyme and finally to an E3 ubiquitin ligase that transfers the ubiquitin to its target protein. It is the final E3 ubiquitin ligase that confers the substrate specificity for ubiquitination and is the focus of this review. Spermatogenesis is a complex and highly regulated process by which spermatogonial stem cells undergo mitotic proliferation and expansion of the diploid spermatogonial population, differentiate into spermatocytes and progress through two meiotic divisions to produce haploid spermatids that proceed through a final morphogenesis to generate mature spermatozoa. The ubiquitination of proteins in the cells of the testis occurs in many of the processes required for the progression of mature spermatozoa. Since it is the E3 ubiquitin ligase that recognizes the target protein and provides the specificity and selectivity for ubiquitination, this review highlights known examples of E3 ligases in the testis and the differing roles that they play in maintaining functional spermatogenesis.
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15
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Lehtihet M, Arver S, Kalin B, Kvist U, Pousette A. Left-sided grade 3 varicocele may affect the biological function of the epididymis. Scand J Urol 2013; 48:284-9. [PMID: 24354516 DOI: 10.3109/21681805.2013.868513] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Varicocele is present in approximately 30-40% of men evaluated for infertility and in 10-20% of the general male population, but the association between varicocele, compromised semen quality and male infertility remains unclear. This indicates that varicocele may impair spermatogenesis or in some other way mitigate sperm quality. Better understanding of criteria for the selection of men who will benefit from varicocele repair would improve the clinical management of men with impaired semen quality and varicocele. MATERIAL AND METHODS To further understand the effect of varicocele repair by embolization in men with grade 3 varicocele, 50 men referred for infertility with varicocele were evaluated before and after embolization. RESULTS There was a significant improvement in total sperm count (25.5 ± 4.7 million to 78 ± 11 million, p < 0.001) and sperm motility (slowly and rapidly progressive) (31.5 ± 2.9% to 45 ± 2.5%, p < 0.001) after spermatic vein embolization, comparing baseline to 3 month post-treatment follow-up data. Furthermore, alpha-glucosidase (specific epididymis-derived protein) increased from 61.7 ± 5.7 U to 84.7 ± 7.0 U (p < 0.05) and sperm droplets decreased from 14.2 ± 1.5% to 11.0 ± 1.0% (p < 0.05). CONCLUSION The results indicate improved epididymal function and suggest that left-sided grade 3 varicocele may affect the epididymis in addition to effects on the testis.
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Affiliation(s)
- Mikael Lehtihet
- Department of Medicine/Huddinge, Karolinska Institutet and Centre for Andrology and Sexual Medicine, Karolinska University Hospital , Stockholm , Sweden
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Semen levels of spermatid-specific thioredoxin-3 correlate with pregnancy rates in ART couples. PLoS One 2013; 8:e61000. [PMID: 23734172 PMCID: PMC3667087 DOI: 10.1371/journal.pone.0061000] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 03/05/2013] [Indexed: 12/22/2022] Open
Abstract
Spermatid specific thioredoxin-3 (SPTRX3 or TXNDC8) is a testis/male germ line specific member of thioredoxin family that accumulates in the superfluous cytoplasm of defective human spermatozoa. We hypothesized that semen levels of SPTRX3 are reflective of treatment outcome in assisted reproductive therapy (ART) couples treated by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Relationship between SPTRX3 and treatment outcome was investigated in 239 couples undergoing ART at an infertility clinic. Sperm content of SPTRX3 was evaluated by flow cytometry and epifluorescence microscopy, and correlated with clinical semen analysis parameters, and data on embryo development and pregnancy establishment. High SPTRX3 levels (>15% SPTRX3-positive spermatozoa) were found in 51% of male infertility patients (n = 72), in 20% of men from couples with unexplained, idiopathic infertility (n = 61) and in 14% of men from couples previously diagnosed with female-only infertility (n = 85). Couples with high SPTRX3 produced fewer two-pronuclear zygotes and had a reduced pregnancy rate (19.2% pregnant with >15% SPTRX3-positive spermatozoa vs. 41.2% pregnant with <5% SPTRX3-positive sperm; one-sided p<0.05). The average pregnancy rate of all 239 couples was 25.1%. Live birth rate was 19.2% and lowest average SPTRX3 levels were found in couples that delivered twins. Men with >15% of SPTRX3-positive spermatozoa, a cutoff value established by ROC analysis, had their chance of fathering children by IVF or ICSI reduced by nearly two-thirds. The percentage of SPTRX3-positive spermatozoa had predictive value for pregnancy after ART. Gradient purification and sperm swim-up failed to remove all SPTRX3-positive spermatozoa from semen prepared for ART. In summary, the elevated semen content of SPTRX3 in men from ART couples coincided with reduced incidence of pregnancy by IVF or ICSI, identifying SPTRX3 as a candidate biomarker reflective of ART outcome.
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Aitken RJ, Baker MA, O'Bryan M. Andrology Lab Corner*: Shedding Light on Chemiluminescence: The Application of Chemiluminescence in Diagnostic Andrology. ACTA ACUST UNITED AC 2013; 25:455-65. [PMID: 15223833 DOI: 10.1002/j.1939-4640.2004.tb02815.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- R John Aitken
- ARC Centre of Excellence in Biotechnology and Development, Discipline of Biological Sciences, Faculty of Science and IT, University of Newcastle, Callaghan, New South Wales, Australia.
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Franken DR, Oehninger S. Semen analysis and sperm function testing. Asian J Androl 2011; 14:6-13. [PMID: 22179512 DOI: 10.1038/aja.2011.58] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Despite controversy regarding the clinical value of semen analysis, male fertility investigation still relies on a standardized analysis of the semen parameters. This is especially true for infertility clinics in both developing and developed countries. Other optional tests or sophisticated technologies have not been widely applied. The current review addresses important changes in the analysis of semen as described in the new World Health Organization (WHO) manual for semen analysis. The most important change in the manual is the use of evidence-based publications as references to determine cutoff values for normality. Apart from the above mentioned changes, the initial evaluation and handling methods remain, in most instances, the same as in previous editions. Furthermore, the review evaluates the importance of quality control in andrology with emphasis on the evaluation of sperm morphology. WHO sperm morphology training programmes for Sub-Saharan countries were initiated at Tygerberg Hospital in 1995. The external quality control programme has ensured that the majority of participants have maintained their morphological reading skills acquired during initial training. This review reports on current sperm functional tests, such as the induced acrosome reaction, and sperm-zona pellucida binding assays, as well as the impact of sperm quality in terms of DNA integrity, and the relationship of sperm function tests to sperm morphology.
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Affiliation(s)
- Daniel R Franken
- Department of Obstetrics and Gynaecology, Tygerberg Hospita, Cape Town, South Africa.
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Sperm preparation: state-of-the-art--physiological aspects and application of advanced sperm preparation methods. Asian J Androl 2011; 14:260-9. [PMID: 22138904 DOI: 10.1038/aja.2011.133] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
For assisted reproduction technologies (ART), numerous techniques were developed to isolate spermatozoa capable of fertilizing oocytes. While early methodologies only focused on isolating viable, motile spermatozoa, with progress of ART, particularly intracytoplasmic sperm injection (ICSI), it became clear that these parameters are insufficient for the identification of the most suitable spermatozoon for fertilization. Conventional sperm preparation techniques, namely, swim-up, density gradient centrifugation and glass wool filtration, are not efficient enough to produce sperm populations free of DNA damage, because these techniques are not physiological and not modeled on the stringent sperm selection processes taking place in the female genital tract. These processes only allow one male germ cell out of tens of millions to fuse with the oocyte. Sites of sperm selection in the female genital tract are the cervix, uterus, uterotubal junction, oviduct, cumulus oophorus and the zona pellucida. Newer strategies of sperm preparation are founded on: (i) morphological assessment by means of 'motile sperm organelle morphological examination (MSOME)'; (ii) electrical charge; and (iii) molecular binding characteristics of the sperm cell. Whereas separation methods based on electrical charge take advantage of the sperm's adherence to a test tube surface or separate in an electrophoresis, molecular binding techniques use Annexin V or hyaluronic acid (HA) as substrates. Techniques in this category are magnet-activated cell sorting, Annexin V-activated glass wool filtration, flow cytometry and picked spermatozoa for ICSI (PICSI) from HA-coated dishes and HA-containing media. Future developments may include Raman microspectrometry, confocal light absorption and scattering spectroscopic microscopy and polarization microscopy.
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Abstract
Sperm DNA can be damaged due to a multitude of different noxae, which include disease, and occupational and environmental factors. Depending on the magnitude of the damage, such lesions may be repaired by the oocyte or the embryo. If this is not possible, a permanent damage can be manifested leading to mutations of the male genome. In cases where the oocyte or the embryo does not counter these damages to the male genome in terms of repair or an early abortion, sperm DNA damage and fragmentation can be a cause of numerous diseases including childhood cancer.
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Affiliation(s)
- Ralf R. Henkel
- Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
| | - Daniel R. Franken
- Department of Obstetrics and Gynaecology, University of Stellenbosch, Tygerberg, South Africa
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A young Drosophila duplicate gene plays essential roles in spermatogenesis by regulating several Y-linked male fertility genes. PLoS Genet 2010; 6:e1001255. [PMID: 21203494 PMCID: PMC3009665 DOI: 10.1371/journal.pgen.1001255] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 11/19/2010] [Indexed: 11/30/2022] Open
Abstract
Gene duplication is supposed to be the major source for genetic innovations. However, how a new duplicate gene acquires functions by integrating into a pathway and results in adaptively important phenotypes has remained largely unknown. Here, we investigated the biological roles and the underlying molecular mechanism of the young kep1 gene family in the Drosophila melanogaster species subgroup to understand the origin and evolution of new genes with new functions. Sequence and expression analysis demonstrates that one of the new duplicates, nsr (novel spermatogenesis regulator), exhibits positive selection signals and novel subcellular localization pattern. Targeted mutagenesis and whole-transcriptome sequencing analysis provide evidence that nsr is required for male reproduction associated with sperm individualization, coiling, and structural integrity of the sperm axoneme via regulation of several Y chromosome fertility genes post-transcriptionally. The absence of nsr-like expression pattern and the presence of the corresponding cis-regulatory elements of the parental gene kep1 in the pre-duplication species Drosophila yakuba indicate that kep1 might not be ancestrally required for male functions and that nsr possibly has experienced the neofunctionalization process, facilitated by changes of trans-regulatory repertories. These findings not only present a comprehensive picture about the evolution of a new duplicate gene but also show that recently originated duplicate genes can acquire multiple biological roles and establish novel functional pathways by regulating essential genes. Gene duplication has long been appreciated as a major source for new genes and new functions. Nevertheless, it is still a fascinating mystery how new duplicate genes are functionally integrated into the existing gene network and how they contribute to the novel functions of organisms at the pathway level. By studying the recently originated kep1 gene family in Drosophila melanogaster, we show that one of the young duplicate genes, nsr, has evolved important biological functions associated with male reproduction by regulating several essential fertility genes in the short evolutionary period after its birth. The evolutionary dynamics, biological roles, and the underlying molecular mechanism of nsr revealed in this study present a vivid and comprehensive example of how new genes acquire important biological functions and demonstrate that recently originated new genes can regulate pre-existing essential genes and create novel architectures of genetic pathways.
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22
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Henkel RR. Leukocytes and oxidative stress: dilemma for sperm function and male fertility. Asian J Androl 2010; 13:43-52. [PMID: 21076433 DOI: 10.1038/aja.2010.76] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Spermatozoa are constantly exposed to the interphase between oxidation through high amounts of reactive oxygen species (ROS) and leukocytes, and reduction by means of scavengers and antioxidants. Considering the very special functions as being the only cells with such high polarization and exerting their functions outside the body, even in a different individual, the female genital tract, the membranes of these cells are chemically composed of an extraordinary high amount of polyunsaturated fatty acids. This in turn, renders them very susceptible to oxidative stress, which is defined as an imbalance between oxidation and reduction towards the oxidative status. As a result, ROS deriving from both leukocytes and the male germ cells themselves cause a process called 'lipid peroxidation' and other damages to the sperm cell. On the other hand, a certain limited amount of ROS is essential in order to trigger vital physiological reactions in cells, including capacitation or the acrosome reaction in sperm. The treatment of patients with antioxidants to compensate the oxidative status caused by oxidative stress is highly debated as uncontrolled antioxidative treatment might derail the system towards the reduced status, which is also unphysiological and can even induce cancer. This paradox is called the 'antioxidant paradox'. Therefore, a proper andrological diagnostic work-up, including the evaluation of ROS levels and the antioxidant capacity of the semen, has to be carried out beforehand, aimed at keeping the fine balance between oxidation and scavenging of vital amounts of ROS.
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Affiliation(s)
- Ralf R Henkel
- Department of Medical Biosciences, University of the Western Cape, Bellville 7535, South Africa.
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Nasr-Esfahani MH, Abasi H, Razavi S, Ashrafi S, Tavalaee M. Varicocelectomy: semen parameters and protamine deficiency. ACTA ACUST UNITED AC 2009; 32:115-22. [DOI: 10.1111/j.1365-2605.2007.00822.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Laudat A, Lecourbe K. Diminution du pourcentage d’acrosomes malformés après un test de migration–survie des spermatozoïdes. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.immbio.2008.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Hurtado de Catalfo GE, Ranieri-Casilla A, Marra FA, de Alaniz MJT, Marra CA. Oxidative stress biomarkers and hormonal profile in human patients undergoing varicocelectomy. ACTA ACUST UNITED AC 2007; 30:519-30. [PMID: 17573856 DOI: 10.1111/j.1365-2605.2007.00753.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The aetiology of varicocele is multifactorial although hormonal imbalance and oxidative stress play a key role in the progression of illness. No conclusive evidence has been presented previously, describing the changes in these two factors and the evolution of patients after varicocelectomy. Semen characteristics and hormonal profile were analysed in 36 infertile men with unilateral left varicocele and 33 age-paired controls (proved to be fertile men), after careful inclusion/exclusion selection criteria. Liposoluble and hydrosoluble antioxidants, oligoelements and enzyme activities of the antioxidant defence system were also determined in plasma and erythrocyte from antecubital and spermatic veins, and in spermatozoa. Data were compared between groups at different times before and after varicocelectomy. Decreased levels of liposoluble and hydrosoluble antioxidants and increased activities of the antioxidant defence system enzymes were observed in patients compared with controls. Varicocelectomy normalized this condition at different post-surgical times. Levels of Zn and Se in seminal plasma, protein carbonyls and fragmented DNA remained elevated up to 1 month after surgery. Luteinizing and follicle stimulating hormone concentrations exhibited a biphasic behaviour while testosterone was diminished in patients but normalized soon after varicocelectomy. The results clearly demonstrate the link between the antioxidant defence system, hormonal status and semen characteristics along the post-varicocelectomy period. We suggest that oxidative biomarkers may be appropriate in controlling the evolution of post-varicocelectomy patients, and antioxidant supplementation may improve the clinical condition of infertile men with varicocele.
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Affiliation(s)
- Graciela E Hurtado de Catalfo
- INIBIOLP (Instituto de Investigaciones Bioquímicas de La Plata), CONICET-UNLP, Cátedra de Bioquímica de la Facultad de Ciencias Médicas de la Universidad Nacional de La Plata, Argentina
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Moskovtsev SI, Willis J, White J, Mullen JBM. Leukocytospermia: relationship to sperm deoxyribonucleic acid integrity in patients evaluated for male factor infertility. Fertil Steril 2007; 88:737-40. [PMID: 17336968 DOI: 10.1016/j.fertnstert.2006.11.132] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 10/31/2006] [Accepted: 11/27/2006] [Indexed: 11/26/2022]
Abstract
The purpose of our study was to analyze the relationship of leukocytospermia to sperm DNA damage as assessed by the DNA integrity assay. Results indicate that leukocytospermia has a significant negative effect on the standard semen parameters of concentration, motility, and morphology but at most a very weak effect on DNA integrity as measured by the DNA fragmentation assay.
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Affiliation(s)
- Sergey I Moskovtsev
- Andrology Laboratory, Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
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Tarozzi N, Bizzaro D, Flamigni C, Borini A. Clinical relevance of sperm DNA damage in assisted reproduction. Reprod Biomed Online 2007; 14:746-57. [PMID: 17579991 DOI: 10.1016/s1472-6483(10)60678-5] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many studies have shown how a 'paternal effect' can cause repeated assisted reproduction failures. In particular, with increasing experience of intracytoplasmic sperm injection (ICSI), it became evident that spermatozoa from some patients repeatedly fail to form viable embryos, although they can fertilize the oocyte and trigger early preimplantation development. Many authors have shown how this paternal effect can be traced back to anomalies in sperm chromatin organization: the spermatozoa of subfertile men are characterized by numerical abnormalities in spermatozoal chromosome content, Y chromosome microdeletions, alterations in the epigenetic regulation of paternal genome and non-specific DNA strand breaks. In particular, pathologically increased sperm DNA fragmentation is one of the main paternal-derived causes of repeated assisted reproduction failures in the ICSI era. The intention of this review is to describe nuclear sperm DNA damage, with emphasis on its clinical significance and its relationship with male infertility. Assessment of sperm DNA damage appears to be a potential tool for evaluating semen samples prior to their use in assisted reproduction, helping to select spermatozoa with intact DNA or with the least amount of DNA damage for use in assisted conception.
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Affiliation(s)
- Nicoletta Tarozzi
- Tecnobios Procreazione, Centre for Reproductive Health, Via Dante 15, I-40125 Bologna, Italy
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Rago V, Siciliano L, Aquila S, Carpino A. Detection of estrogen receptors ER-alpha and ER-beta in human ejaculated immature spermatozoa with excess residual cytoplasm. Reprod Biol Endocrinol 2006; 4:36. [PMID: 16846491 PMCID: PMC1550242 DOI: 10.1186/1477-7827-4-36] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 07/17/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A key role of estrogens in human sperm biology has been recently suggested by aromatase and estrogen receptor detection in human testicular germ cells and ejaculated spermatozoa. However, the involvement of these hormones in the sperm maturation process is still not defined. The aim of this work was to investigate the expression of estrogen receptors, ER-alpha and ER-beta, in human ejaculated immature spermatozoa with excess residual cytoplasm. METHODS Immunofluorescence labelling has been used to localize ER-alpha and ER-beta proteins in immature spermatozoa isolated by Percoll gradient, while Western blot analysis was carried out on sperm protein extracts. RESULTS Both estrogen receptors were localized in excess residual cytoplasm of immature sperm, while sperm tails showed only ER-beta. Furthermore, in the same cells, immunoblots detected the presence of the full-length (approximately 67 kDa) ER-alpha and (approximately 59 kDa) ER-beta proteins, together with a approximately 50 kDa ER-beta species, lacking in mature sperm. CONCLUSION The present investigation demonstrated ER-alpha and ER-beta presence in excess residual cytoplasm of human abnormal sperm cells, suggesting the hypothesis that both the 'classical' ERs could be able to mediate estrogen action in spermatogenetic cells. Furthermore, the presence of the short ER-beta form in abnormal germ cells and its disappearance in mature sperm, support estrogen modulation via different ER forms during sperm maturation.
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Affiliation(s)
- Vittoria Rago
- Department of Cell Biology, Faculty of Pharmacy, University of Calabria, Cosenza, Italy
| | - Laura Siciliano
- Department of Cell Biology, Faculty of Pharmacy, University of Calabria, Cosenza, Italy
| | - Saveria Aquila
- Department of Pharmaco-Biology, Faculty of Pharmacy, University of Calabria, Cosenza, Italy
| | - Amalia Carpino
- Department of Cell Biology, Faculty of Pharmacy, University of Calabria, Cosenza, Italy
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Bassols J, Kádár E, Briz M, Pinart E, Sancho S, Garcia-Gil N, Badia E, Pruneda A, Bussalleu E, Yeste M, Casas I, Dacheux JL, Bonet S. Evaluation of boar sperm maturation after co-incubation with caput, corpus and cauda epididymal cultures. Theriogenology 2005; 64:1995-2009. [PMID: 15964065 DOI: 10.1016/j.theriogenology.2005.05.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2005] [Revised: 03/29/2005] [Accepted: 05/01/2005] [Indexed: 11/17/2022]
Abstract
Boar sperm from the proximal caput epididymis were co-incubated with 1, 4, 7, 10 and 14-day old caput, corpus and cauda epididymal cultures for 24, 48 and 72 h. Boar kidney epithelial cells (LLC-PK1) and ECM alone were used as negative controls. Sperm motility, morphology and membrane integrity were studied to evaluate boar sperm maturation in vitro. Our results showed that epithelial cell monolayers (10, 14-day old) create a suitable microenvironment for the survival of proximal caput sperm and the maintenance of sperm motility over a 72 h period. Moreover, corpus epididymal tubule fragments in culture (1, 4-day old) are capable of promoting the migration of the cytoplasmic droplet along the sperm tail after 24h of co-incubation.
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Affiliation(s)
- J Bassols
- Biotechnology of Porcine Reproduction, Department of Biology, INTEA, Faculty of Sciences, University of Girona, Campus Montilivi s/n, 17071 Girona, Spain
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Abstract
It has been widely held that all that fathers essentially contribute to the next generation is half their genome. However, recent progress towards understanding biological processes such as sperm maturation and fertilization now indicates that the paternal contribution has been underestimated. To tackle some of the misconceptions surrounding the paternal contribution, the factors that are actually delivered by the sperm at fertilization and their potential developmental functions will be discussed using data from humans and animal models. Although still in their infancy, the practical applications of using sperm RNAs have already emerged in reproductive medicine as markers that are indicative of successful vasectomy. They are also beginning to appear in the forensic sciences and, within the next decade, might appear in the environmental sciences.
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Affiliation(s)
- Stephen A Krawetz
- Department of Obstetrics and Gynecology, Center for Molecular Medicine and Genetics, Institute for Scientific Computing, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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31
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Henkel R, MAAß G, Bödeker RH, Scheibelhut C, Stalf T, Mehnert C, Schuppe HC, Jung A, Schill WB. Sperm function and assisted reproduction technology. Reprod Med Biol 2005; 4:7-30. [PMID: 29699207 DOI: 10.1111/j.1447-0578.2005.00087.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The evaluation of different functional sperm parameters has become a tool in andrological diagnosis. These assays determine the sperm's capability to fertilize an oocyte. It also appears that sperm functions and semen parameters are interrelated and interdependent. Therefore, the question arose whether a given laboratory test or a battery of tests can predict the outcome in in vitro fertilization (IVF). One-hundred and sixty-one patients who underwent an IVF treatment were selected from a database of 4178 patients who had been examined for male infertility 3 months before or after IVF. Sperm concentration, motility, acrosin activity, acrosome reaction, sperm morphology, maternal age, number of transferred embryos, embryo score, fertilization rate and pregnancy rate were determined. In addition, logistic regression models to describe fertilization rate and pregnancy were developed. All the parameters in the models were dichotomized and intra- and interindividual variability of the parameters were assessed. Although the sperm parameters showed good correlations with IVF when correlated separately, the only essential parameter in the multivariate model was morphology. The enormous intra- and interindividual variability of the values was striking. In conclusion, our data indicate that the andrological status at the end of the respective treatment does not necessarily represent the status at the time of IVF. Despite a relatively low correlation coefficient in the logistic regression model, it appears that among the parameters tested, the most reliable parameter to predict fertilization is normal sperm morphology. (Reprod Med Biol 2005; 4: 7-30).
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Affiliation(s)
- Ralf Henkel
- Department of Urology, Friedrich Schiller University, Jena.,Center for Dermatology and Andrology
| | - Gesa MAAß
- Center for Dermatology and Andrology
| | - Rolf-Hasso Bödeker
- Institute for Medical Informatics, Working Group for Medical Statistics, and
| | | | - Thomas Stalf
- Institute for Reproductive Medicine, Justus Liebig University, Giessen, Germany
| | - Claas Mehnert
- Institute for Reproductive Medicine, Justus Liebig University, Giessen, Germany
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Henkel R, Maa\ G, Bödeker RH, Scheibelhut C, Stalf T, Mehnert C, Schuppe HC, Jung A, Schill WB. Sperm function and assisted reproduction technology. Reprod Med Biol 2005. [DOI: 10.1007/bf03016134] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Henkel R, Kierspel E, Stalf T, Mehnert C, Menkveld R, Tinneberg HR, Schill WB, Kruger TF. Effect of reactive oxygen species produced by spermatozoa and leukocytes on sperm functions in non-leukocytospermic patients. Fertil Steril 2005; 83:635-42. [PMID: 15749492 DOI: 10.1016/j.fertnstert.2004.11.022] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Revised: 08/07/2004] [Accepted: 08/07/2004] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To investigate whether there is an impact of different sources of reactive oxygen species (ROS) on sperm functions. DESIGN Prospective study. SETTING Patients at the Center for Dermatology and Andrology, Giessen, Germany. PATIENT(S) Semen collected from 63 randomly collected patients attending the IVF unit of the University of Giessen, Germany. INTERVENTION(S) Only patients with nonleukocytospermia were included in this study. MAIN OUTCOME MEASURE(S) Sperm count and motility before and after sperm separation by swim-up, morphology, DNA fragmentation, and extrinsic (by leukocytes) and intrinsic ROS production (by spermatozoa) were evaluated. RESULT(S) Leukocytes correlated significantly with extrinsic ROS production (r = 0.576), but markedly less with intrinsic ROS production (r = 0.296). Sperm count, morphology, and motility in the ejaculate were markedly more affected by extrinsic than by intrinsic ROS. The DNA fragmentation was strongly positively correlated with intrinsic ROS production, whereas this correlation was weaker for extrinsic ROS production. No correlation was found between DNA fragmentation and the number of leukocytes, whereas the correlations with motility in the ejaculate and the motile sperm count after swim-up were highly significant. Moreover, significant differences were observed for extrinsic and intrinsic ROS production between groups of patients having a high (> or = 1 x 10(6)/mL) and a low number (<1 x 10(6)/mL) of leukocytes in the ejaculate. CONCLUSION(S) The origin of ROS seems to have an influence on the site of the damage. Because leukocyte counts <1 x 10(6)/mL caused a significant decrease of motility and DNA integrity, the threshold given by the World Health Organization (WHO) should be re-evaluated.
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Affiliation(s)
- Ralf Henkel
- Center for Dermatology and Andrology, Justus Liebig University, Giessen, Germany.
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Henderson NA, Robaire B. Effects of PNU157706, a Dual 5α-Reductase Inhibitor, on Rat Epididymal Sperm Maturation and Fertility1. Biol Reprod 2005; 72:436-43. [PMID: 15483222 DOI: 10.1095/biolreprod.104.033548] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Sperm entering the epididymis gain progressive motility and fertilizing ability in a process termed maturation. The functional dependence of the epididymis on dihydrotestosterone (DHT) is well established, yet few studies have examined the consequences on the epididymis of inhibiting DHT formation. We have shown that inhibition of both isoforms of 5alpha-reductase (types 1 and 2), the enzyme that converts testosterone to DHT, has pronounced effects on epididymal gene expression. In the present study, we investigate whether inhibiting 5alpha-reductase has consequences on epididymal sperm maturation. Rats were treated with vehicle or 10 mg/kg/day PNU157706, a dual-type inhibitor, for 28 days. Fertility and several key facets of sperm maturation were analyzed. Changes in sperm motility were assessed by computer-assisted sperm analysis (CASA). Changes in sperm morphology were assessed by CASA and electron microscopy. The motility of spermatozoa from the cauda epididymidis of treated animals showed a significant decrease in both the percentage of motile and progressively motile sperm as well as altered motion parameters. The morphology of cauda epididymal spermatozoa was also adversely affected by the treatment; the most prominent effect was a markedly elevated proportion of sperm that retained their cytoplasmic droplet. Matings with treated males resulted in fewer successful pregnancies and a higher rate of preimplantation loss. Progeny outcome was unaffected. The compromised sperm motility and morphology likely contribute to the subfertility of inhibitor-treated rats. Our results indicate a role for dual 5alpha-reductase inhibitors in further studies of epididymal physiology and as a potential component of a male contraceptive.
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Affiliation(s)
- Natali Anne Henderson
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
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35
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Abstract
The term cytoplasmic droplets is used to mean two different structures by basic scientists and clinicians. The literature on the presence, position and loss of cytoplasmic droplets and their relationship to infertility in animal species is reviewed. It is proposed that a change in terminology is required: 'cytoplasmic droplet' should be used to describe normal droplets associated with functional sperm produced by normal spermatogenesis and 'excess residual cytoplasm' is suggested to describe abnormal droplets associated with dysfunctional sperm that are products of faulty spermatogenesis.
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Affiliation(s)
- T G Cooper
- Institute of Reproductive Medicine of the University Clinic, Münster, Domagkstrasse 11, D-48129 Münster, Germany.
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36
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Nicòtina PA, Romeo C, Arena S, Arena F, Maisano D, Zuccarello B. Immunoexpression of aquaporin-1 in adolescent varicocele testes: Possible significance for fluid reabsorption. Urology 2005; 65:149-52. [PMID: 15667881 DOI: 10.1016/j.urology.2004.08.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2004] [Accepted: 08/12/2004] [Indexed: 10/25/2022]
Abstract
OBJECTIVES To investigate the immunoexpression of aquaporin-1 (AQP-1), a major transmembrane water channel, in high-grade varicocele testes, which are known to imply an unbalanced transmembrane water flow, in both tubular and extratubular compartments. METHODS Light microscopy and AQP-1 immunohistologic examination were carried out on incisional testicular biopsies from 20 adolescent boys, aged 13 to 18 years, with grade 2 or 3 idiopathic varicocele. Testicular tissue from 4 autopsied subjects of matched age were also investigated as parallel controls. RESULTS At microscopic examination, the tubular lumina and extracellular matrix were expanded and venular profiles dilated. Cytoplasmic vacuoles were frequent in the Sertoli cells, spermatogonia, and spermatocytes, together with premature sloughing of germ cells and residual cytoplasmic droplets inside the spermatozoa, if present. Diffuse AQP-1 positivity occurred at venular endothelial cell membranes and, unexpectedly, at the cell membranes of the Sertoli cells, diploid germ cells, and haploid cells. In the control testes, focal AQP-1 immunolabeling was confined to the microvessel endothelial cells, without any positive reaction in the tubular or extratubular compartments. CONCLUSIONS This is the first report showing AQP-1 cell expression in adolescent varicocele testes in both tubular and extratubular compartments. It was associated with the main histologic features of unbalanced water flow in the tubular and interstitial compartments of the testis. Immunocytochemical patterns revealed AQP-1 as a possible critical reabsorption factor, acting to reduce abnormal fluid retention in endotubular cells and the extracellular matrix and, to a lesser extent, in Leydig cells.
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Affiliation(s)
- P A Nicòtina
- Department of Human Pathology, University of Messina Medical School, Messina, Italy.
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Cooper TG, Yeung CH, Fetic S, Sobhani A, Nieschlag E. Cytoplasmic droplets are normal structures of human sperm but are not well preserved by routine procedures for assessing sperm morphology. Hum Reprod 2004; 19:2283-8. [PMID: 15242996 DOI: 10.1093/humrep/deh410] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND There is a discrepancy between the use of terminology employed by clinicians and basic scientists concerning the cytoplasmic droplets of sperm. Most clinicians consider their presence on sperm to be indicative of abnormal sperm, whereas basic scientists consider them to be attributes of normal sperm. METHODS The presence of cytoplasmic droplets on human sperm was examined using conventional air-dried, fixed and stained sperm smears and in living and fixed wet preparations. RESULTS Cytoplasmic droplets were found on the majority of motile sperm and in fixed preparations but only half of them were found in air-dried smears. There was no relationship between the presence of abnormally large cytoplasmic droplets, indicative of abnormal sperm, and the droplets found on living cells. CONCLUSION The term 'cytoplasmic droplet' is confusingly used to describe two different sperm structures: large amounts of retained, excessive cytoplasmic remnants, that survive the air-drying procedure and are observed on abnormal sperm in conventionally stained sperm smears, and osmotically sensitive vesicles that are present on normal living sperm. A plea is made to retain the term 'cytoplasmic droplet' for the latter structure of normal sperm and to use the term 'excess residual cytoplasm' to describe the abnormally retained cytoplasm observed on abnormal sperm in smears.
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Affiliation(s)
- Trevor G Cooper
- Institute of Reproductive Medicine of the University Clinic, Domagkstrasse 11, D-48129 Münster, Germany.
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Kotula-Balak M, Grzmil P, Styrna J, Bilińska B. Immunodetection of aromatase in mice with a partial deletion in the long arm of the Y chromosome. Acta Histochem 2004; 106:55-64. [PMID: 15032329 DOI: 10.1016/j.acthis.2003.09.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aromatization of androgens into estrogens is catalyzed by a microsomal enzyme, P450 aromatase. Males of the mouse strain B10.BR and its congenic mutant strain B10.BR-Ydel (with a partial deletion in the long arm of the Y chromosome) were used to identify the cellular source of estrogens within the testis. Immunocytochemistry was applied to localize aromatase in cultured Leydig cells, cytoplasmic droplets attached to flagella of spermatozoa, and sections of testes. The presence of aromatase in testes was checked by means of Western-blot analysis. Steroid hormones secreted by Leydig cells in vitro were measured in homogenates of testes using radioimmunological methods. Additionally, a Southern analysis was performed using the Y353/B probe to check the length of the deletion in the Y chromosome. In sections of testis of B10.BR mice, weak to moderate immunohistochemical staining of aromatase was found in Leydig cells, Sertoli cells, and germ cells. In testicular cells of B10.BR-Ydel mice, stronger immunostaining of aromatase was observed, especially in germ cells and Leydig cells. Positivity for aromatase was also found in the cytoplasm of cultured Leydig cells from both strains, but it was higher in cells derived from mutant males. Western-blot analysis revealed one major band of approx. 55kDa of aromatase in testes from both strains. Lower testosterone levels were found in mutant males in supernatants of culture media and homogenates of testes in comparison with control males. In contrast, estradiol levels were always higher in mutants. Therefore, it seems likely that the increased expression of aromatase and, as a consequence, the higher levels of endogenous estrogens enhance the morphological alterations in testis and affect spermatogenesis in mutant males.
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Affiliation(s)
- Małgorzata Kotula-Balak
- Laboratory of Endocrinology and Tissue Culture, Department of Animal Physiology, Institute of Zoology, Jagiellonian University, Ingardena 6, Kraków 30-060, Poland
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Aitken RJ, Sawyer D. The human spermatozoon--not waving but drowning. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 518:85-98. [PMID: 12817679 DOI: 10.1007/978-1-4419-9190-4_8] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The poor quality of the human ejaculate sets man apart from all other mammalian species. Even in normal fertile men the ejaculate may contain up to 85% abnormal forms according to the World Heath Organization (1999). In the wake of this poor semen quality comes extremely poor fertility (Hull et al, 1985) and the highest rates of aneuploidy, pregnancy loss and birth defects in viviparous vertebrates. Thus, the poor quality of human spermatozoa is reflected in both their capacity for fertilization and their genetic integrity. The ultimate cause of defective sperm function is unknown. In certain patients a genetic basis for male infertility has been identified involving DNA deletions on the long arm of the Y chromosome. Such deletions might explain the impoverished semen quality seen in about 10-14% of men with severely impaired spermatogenesis, but fail to explain the infertility seen in most (>85%) cases of male infertility. One of the key attributes and probable causes of defective sperm function is oxidative stress created by excessive ROS generation by the spermatozoa and/or the disruption of antioxidant defence systems in the male reproductive tract. Excess free radical generation frequently involves an error in spermiogenesis resulting in the release of spermatozoa from the germinal epithelium exhibiting abnormally high levels of cytoplasmic retention. The excess cytoplasm contains enzymes that fuel the generation of ROS by the spermatozoa's plasma membrane redox systems. The consequences of such oxidative stress include a loss of motility and fertilizing potential and the induction of DNA damage in the sperm nucleus. The loss of sperm function is due to the peroxidation of unsaturated fatty acids in the sperm plasma membrane as a consequence of which the latter loses its fluidity and the cells lose their function. The causes and consequences of oxidative damage to the DNA in the sperm nucleus are still not known with certainty. The available evidence suggests that early pregnancy loss and morbidity in the offspring, including childhood cancer, are associated with such damage. Developing animal models with which to establish the validity of these relationships and identifying the environmental factors associated with the proposed 'testicular dysgenesis syndrome' will clearly be important tasks for the future.
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Affiliation(s)
- R John Aitken
- Discipline of Biological Sciences, Centre for Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.
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40
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Aitken RJ. Founders' Lecture. Human spermatozoa: fruits of creation, seeds of doubt. Reprod Fertil Dev 2004; 16:655-64. [PMID: 15740688 DOI: 10.1071/rd04083] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Accepted: 08/06/2004] [Indexed: 11/23/2022] Open
Abstract
Deoxyribonucleic acid damage in the male germline is associated with defective fertilisation, impaired embryonic development, reduced implantation, abortion and childhood disease. Oxidative stress and the retention of excess residual cytoplasm by the spermatozoa are frequently associated with the induction of such damage. The redox cycling of xenobiotics by oxido-reductases in the germline, the patient’s age, the incidence of genital tract infections and Sertoli cell dysfunction are all possible contributors to DNA damage in germ cells. Collateral peroxidation of unsaturated fatty acids in the sperm plasma membrane generally ensures that spermatozoa experiencing severe oxidative DNA damage cannot participate in the process of fertilisation. The adaptive termination of pregnancy through the selective vulnerability of genes involved in placentation may also help prevent the vertical transmission of damaged DNA. However, the ultimate safeguard against this form of damage will be to understand the biochemical basis of oxidative stress in human spermatozoa, so that the underlying causative mechanisms can be addressed in a logical manner.
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Affiliation(s)
- R John Aitken
- ARC Centre of Excellence in Biotechnology and Development and Reproductive Science Group, Discipline of Biological Sciences, University of Newcastle, NSW, Australia.
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41
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Abstract
Spermatozoa were the first cell type in which the cellular generation of reactive oxygen was demonstrated. This activity has now been confirmed in spermatozoa from all mammalian species examined including the rat, mouse, rabbit, horse, bull and human being. Under physiological circumstances, cellular redox activity is thought to drive the cAMP-mediated, tyrosine phosphorylation events associated with sperm capacitation. In addition to this biological role, human spermatozoa also appear to suffer from oxidative stress, with impacts on the normality of their function and the integrity of their nuclear and mitochondrial DNA. Recent studies have helped to clarify the molecular basis for the intense redox activity observed in defective human spermatozoa, the nature of the subcellular structures responsible for this activity and possible mechanisms by which oxidative stress impacts on these cells. Given the importance of oxidative damage in the male germ line to the origins of male infertility, early pregnancy loss and childhood disease, this area of sperm biochemistry deserves attention from all those interested in improved methods for the diagnosis, management and prevention of male-mediated reproductive failure.
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Huh JR, Vernooy SY, Yu H, Yan N, Shi Y, Guo M, Hay BA. Multiple apoptotic caspase cascades are required in nonapoptotic roles for Drosophila spermatid individualization. PLoS Biol 2003; 2:E15. [PMID: 14737191 PMCID: PMC300883 DOI: 10.1371/journal.pbio.0020015] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2003] [Accepted: 11/14/2003] [Indexed: 11/18/2022] Open
Abstract
Spermatozoa are generated and mature within a germline syncytium. Differentiation of haploid syncytial spermatids into single motile sperm requires the encapsulation of each spermatid by an independent plasma membrane and the elimination of most sperm cytoplasm, a process known as individualization. Apoptosis is mediated by caspase family proteases. Many apoptotic cell deaths in Drosophila utilize the REAPER/HID/GRIM family proapoptotic proteins. These proteins promote cell death, at least in part, by disrupting interactions between the caspase inhibitor DIAP1 and the apical caspase DRONC, which is continually activated in many viable cells through interactions with ARK, the Drosophila homolog of the mammalian death-activating adaptor APAF-1. This leads to unrestrained activity of DRONC and other DIAP1-inhibitable caspases activated by DRONC. Here we demonstrate that ARK- and HID-dependent activation of DRONC occurs at sites of spermatid individualization and that all three proteins are required for this process. dFADD, the Drosophila homolog of mammalian FADD, an adaptor that mediates recruitment of apical caspases to ligand-bound death receptors, and its target caspase DREDD are also required. A third apoptotic caspase, DRICE, is activated throughout the length of individualizing spermatids in a process that requires the product of the driceless locus, which also participates in individualization. Our results demonstrate that multiple caspases and caspase regulators, likely acting at distinct points in time and space, are required for spermatid individualization, a nonapoptotic process. Known as executors of programmed cell death, several caspases are here shown to be involved in Drosophila spermatogenesis, a process that resembles in many ways the generation of individual sperm cells in mammals, including humans
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Affiliation(s)
- Jun R Huh
- Division of Biology, California Institute of Technology, Pasadena, California, USA
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Aitken RJ, Baker MA, Sawyer D. Oxidative stress in the male germ line and its role in the aetiology of male infertility and genetic disease. Reprod Biomed Online 2003; 7:65-70. [PMID: 12930576 DOI: 10.1016/s1472-6483(10)61730-0] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The human male is characterized by extremely poor semen quality as reflected in the number, morphology and motility of the spermatozoa and a high incidence of nuclear and mitochondrial DNA damage. As a consequence of these factors, defective sperm function is thought to be a major contributor to the aetiology of human infertility, as well as childhood diseases including dominant genetic mutations such as achondroplasia and cancer. Factors associated with the origin of poor semen quality include: (i) a lack of selection pressure for high fecundity genes in developed countries, (ii) an evolutionary lineage associated with the deterioration of several male fertility genes in humans and their close ancestors, (iii) genetic factors including, but not limited to, Y-chromosome deletions (iv) paternal age and (v) environmental factors. A model is proposed whereby factors such as ageing or environmental toxicants initiate DNA strand breakage in the spermatozoa of affected males, eventually leading to a mutation in the embryo. This hypothesis stresses the importance of discovering the identity of those environmental factors that are capable of damaging DNA integrity in the male germ line. Such information could make an important contribution to understanding of the origins of both male infertility and a variety of pathological conditions that affect humans, including cancer and dominant genetic disease.
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Affiliation(s)
- R John Aitken
- ARC Centre of Excellence in Biotechnology and Development, Discipline of Biological Sciences, School of Environmental and Life Sciences, University of Newcastle, NSW 2308, Australia.
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44
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Henkel R, Kierspel E, Hajimohammad M, Stalf T, Hoogendijk C, Mehnert C, Menkveld R, Schill WB, Kruger TF. DNA fragmentation of spermatozoa and assisted reproduction technology. Reprod Biomed Online 2003; 7:477-84. [PMID: 14656411 DOI: 10.1016/s1472-6483(10)61893-7] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Despite the ever-increasing knowledge of the fertilization process, there is still a need for better understanding of the causes of sperm DNA fragmentation and its impact on fertilization and pregnancy. For this reason, human sperm DNA fragmentation was investigated by means of the terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling (TUNEL) assay and the production of reactive oxygen species (ROS) in the ejaculate and in the spermatozoa themselves. These data were correlated with fertilization and pregnancy data from IVF and intracytoplasmic sperm injection (ICSI) patients. Sperm DNA fragmentation did not correlate with fertilization rate, but there was a significantly reduced pregnancy rate in IVF patients inseminated with TUNEL-positive spermatozoa. ICSI patients exhibited the same tendency. This implies that spermatozoa with damaged DNA are able to fertilize an oocyte, but at the time the paternal genome is switched on, further development stops. The determination of ROS in the ejaculate and the percentage of ROS-producing spermatozoa revealed markedly stronger correlations between sperm functions (i.e. motility) and the percentage of ROS-producing spermatozoa. The influence of seminal leukocytes, known to produce large amounts of oxidants, on sperm DNA fragmentation should not be neglected.
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Affiliation(s)
- Ralf Henkel
- Centre for Dermatology and Andrology, Justus Liebig University, Gaffkystrasse 14, D-35385 Giessen, Germany.
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Abstract
OBJECTIVES To examine the retention of sperm cytoplasmic droplets (CD) and DNA denaturation (DD) in semen from fertile and infertile men. METHODS Semen samples were obtained from consecutive nonazoospermic men presenting for infertility evaluation (n = 101) and fertile men presenting for vasectomy (n = 13). The standard semen parameters (sperm concentration, motility, and morphology), sperm DD, and sperm CD were monitored. Sperm DD was evaluated by flow cytometry analysis of acridine orange-treated spermatozoa and expressed as the percentage of spermatozoa demonstrating denatured DNA. RESULTS The mean (+/-SE) percentages of spermatozoa with CD and DD were significantly higher in infertile than in fertile men (sperm CD 15.7% +/- 0.8% versus 4.8% +/- 0.7% and sperm DD 22.0% +/- 1.5% versus 10.8% +/- 1.8%, respectively). Sperm CD and DD were positively correlated (r = 0.59). Also, sperm CD and DD values correlated inversely with the standard semen parameters. CONCLUSIONS Our data demonstrate that the retention of sperm CD correlates positively with sperm DD and that significantly higher sperm DD and CD are found in infertile than in fertile men. These data suggest that the enhanced susceptibility of sperm DNA to denaturation is associated with the abnormal disposal of residual sperm cytoplasm in the testis and/or epididymis.
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Affiliation(s)
- Marc Anthony Fischer
- Division of Urology, Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
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Laudat A, Lecourbe K, Guéchot J, Palluel AM. Values of sperm thiobarbituric acid-reactive substance in fertile men. Clin Chim Acta 2002; 325:113-5. [PMID: 12367774 DOI: 10.1016/s0009-8981(02)00289-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND The objective of this study was to establish for the first time reference levels of sperm malondialdehyde, a stable lipid peroxidation product, in a cohort of fertile men. METHODS Sperm malondialdehyde, a thiobarbituric acid-reactive substance, was assayed using the 2-thiobarbituric acid method. RESULTS Sperm malondialdehyde levels, expressed in nM/10(8) spermatozoa, were normally distributed in our cohort of fertile men and averaged 0.0287 +/- 0.0162 (mean +/- S.D.). CONCLUSIONS Given the impact of lipid peroxidation on spermatozoa and thereby on male fertility, the assay of sperm membrane thiobarbituric acid-reactive substance is clearly of interest. Malondialdehyde levels found in our study form a basis for normal values of sperm thiobarbituric acid-reactive substance observed in the semen of fertile men.
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Affiliation(s)
- Antoine Laudat
- Service de Biochimie-Biologie de la Reproduction, Centre Hospitalier Général, BP 407, 28018 Chartres, France.
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Abstract
OBJECTIVE To investigate the influence of nicotine exposure on the ultrastructure of the rat testis. MATERIALS AND METHODS Twenty rats were injected with nicotine at a dose of 0.4 mg/100 g body weight daily for 3 months; a group of 20 control rats matched for weight and age were injected with saline only for the same duration. The testes were then harvested and examined by transmission electron microscopy. RESULTS Rats given nicotine showed: thickening of the tunica propria, caused by an increase in the collagen fibres under the irregular basal lamina; degeneration of junctional specializations between the Sertoli cells, with malformed nuclei showing condensed chromatin; Sertoli cells with numerous polymorphic mitochondria with irregular cristae and an electron-dense matrix. The germ cells were degenerated, spermatids retained excess cytoplasm and accumulated electron-dense lipid droplets in the cytoplasm. The acrosomes were irregular and abnormally configured. CONCLUSION There were ultrastructural alterations in rats exposed to nicotine that could be attributed to the detrimental effects of nicotine on germ cells, peritubular structures and Sertoli cells.
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Affiliation(s)
- K Aydos
- Department of Urology, Histology and Embryology, and Physiology, School of Medicine, University of Ankara, Turkey.
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48
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Thundathil J, Palasz AT, Barth AD, Mapletoft RJ. The use of in vitro fertilization techniques to investigate the fertilizing ability of bovine sperm with proximal cytoplasmic droplets. Anim Reprod Sci 2001; 65:181-92. [PMID: 11267798 DOI: 10.1016/s0378-4320(00)00231-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this experiment was to determine the effect of proximal droplets on sperm-oocyte binding, zona penetration, fertilization, and the developmental competence of oocytes fertilized by sperm with proximal droplets (PD) in an in vitro fertilization (IVF) and culture system. Frozen semen from three bulls (PD1, PD2 and PD3) with varying proportions of normal appearing sperm with proximal droplets and semen from a normal control bull (C) were used in this experiment. The mean number of sperm bound to the zona pellucida (26.8 +/- 2.0, n=100; 15.2 +/- 1.1, n=100; 16.2 +/- 1.0, n=100) for bulls PD1, PD2, and PD3, respectively, were significantly lower (P<0.05) than that of the control bull C (47.4+/- 1.9; n=114). No spermatozoa with PD were found bound to the zona pellucida and this finding was consistent among the three bulls. The percentage penetration of zonae for the bulls PD1, PD2 and PD3 (74%, 74/100; 71%, 71/100 and 69%, 69/100, respectively) were not different than that of bull C (72%, 179/245). Similarly, the mean number of sperm penetrating the zona pellucida (1.43+/- 1.2, 1.24 +/- 1.1 and 1.20 +/- 1.1, for bulls PD1, PD2 and PD3, respectively) were not different than that of bull C (1.45 +/- 1.1). However, fertilization rates (8.8%, 8/90; 16.8%, 16/95; and 10.6%, 11/103, for bulls PD1, PD2 and PD3, respectively) were lower (P<0.001) than that of bull C (68.7%; 77/112). Similarly, cleavage rates (5%, 10/200; 8%, 8/100 and 14%, 15/111) for the bulls PD1, PD2 and PD3, respectively, were lower than that of the control bull, C (60.7%; 79/130). Cleaved zygotes resulting from the fertilization of oocytes by apparently normal sperm from bulls with PD did not develop beyond cleavage, whereas, 43.8% (57/130) morulae and 20% (26/130) blastocysts were produced by oocytes fertilized by sperm from bull C. In summary, normal appearing sperm with PD did not bind to the zona pellucida. Apparently normal sperm with out proximal droplets co-existing in the semen along with sperm containing PD were also functionally deficient, resulting in reduced zonae binding and zygotes resulting from insemination with semen with a high percentage of PD did not develop beyond cleavage.
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Affiliation(s)
- J Thundathil
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, 52 Campus Dr, University of Saskatchewan, SK, S7N 5B4, Saskatoon, Canada
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Amann RP, Seidel GE, Mortimer RG. Fertilizing potential in vitro of semen from young beef bulls containing a high or low percentage of sperm with a proximal droplet. Theriogenology 2000; 54:1499-515. [PMID: 11191872 DOI: 10.1016/s0093-691x(00)00470-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fertilizing potential of semen containing a high percentage of sperm with a proximal droplet was evaluated using IVF. Design criteria: (a) specified semen with >100 x 10(6) sperm/mL with >40% progressively motile spermatozoa, after collection via electro-stimulation; (b) designated a droplet group, bulls whose semen contained >30% spermatozoa with a proximal droplet and <25% with other morphological abnormalities, and a control group, with <25% abnormalities of any type; and (c) stipulated evaluations at 11 to 13 mo of age and again -4 wk later. At the initial evaluation, when a bull was assigned to the droplet group, the next bull meeting control criteria was designated his pair; 15 pairs in four herds were studied. Semen was extended in egg-yolk citrate, cooled to 5 degrees C over approximately 2.5 h, and held at 5 degrees C. After 20 to 44 h, spermatozoa were processed by swimup, incubated with heparin, and co-cultured with oocytes (35 to 56 oocytes/sample; 18 h). Ova were observed for cleavage approximately 42 h after co-culture, and further development was evaluated on day 8. At first evaluation, cleavage rates were 18 and 46% for droplet and control groups (P < 0.01); semen had 34 to 70% and 0 to 12% droplet spermatozoa. For 10 of 15 droplet bulls, <10% of ova were cleaved whereas cleavage rate was >15% for all control bulls. At second evaluation, only three droplet bulls still had >30% of spermatozoa with a proximal droplet. Cleavage rates increased accordingly; only four droplet bulls had <10% cleaved ova and 10 had >34% cleaved ova. Three control bulls had <10% cleaved ova and nine had > or = 34% cleaved ova. Considering all 60 ejaculates, correlation between percentage of spermatozoa with a proximal droplet and percentage of cleaved ova was -0.49 (P < 0.0 1). Correlations between percentages of motile or normal spermatozoa in field evaluations and outcome in IVF were 0.28 and 0.52. Laboratory evaluations of spermatozoa concomitant with preparation for IVF revealed that only incidence of proximal droplets appeared related to outcome in IVF. We concluded: (a) semen from most yearling beef bulls with a high incidence of proximal droplet spermatozoa had severely compromised IVF fertility; (b) as these bulls matured, the incidence of proximal droplets decreased, and IVF fertilizing potential increased; and (c) semen containing >30% spermatozoa with a proximal droplet is strong evidence that fertilizing potential of the bull will be low until the incidence decreases.
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Affiliation(s)
- R P Amann
- Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins 80523, USA
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50
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Mak V, Jarvi K, Buckspan M, Freeman M, Hechter S, Zini A. Smoking is associated with the retention of cytoplasm by human spermatozoa. Urology 2000; 56:463-6. [PMID: 10962316 DOI: 10.1016/s0090-4295(00)00700-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES To determine whether cigarette smoking is associated with the abnormal retention of residual sperm cytoplasm in infertile men. METHODS Semen samples were obtained from 87 consecutive non-azoospermic men with idiopathic infertility (18 smokers and 69 nonsmokers) and from 20 men presenting for vasectomy (fertile controls). Standard semen parameters and the percentage of spermatozoa with residual cytoplasm (on Papanicolaou smears) were recorded. RESULTS Subject age, semen volume, and sperm density, motility, and morphology were not significantly different between the two groups of infertile men. However, a significant difference was found in the mean +/- SEM percentages of sperm with cytoplasm droplets between smokers and nonsmokers (12.9% +/- 1.7% and 8.1% +/- 0.9%, respectively; P < 0.001). CONCLUSIONS Our data suggest that cigarette smoking is associated with retention of sperm cytoplasmic droplets in infertile men, a morphologic characteristic associated with impaired sperm function.
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Affiliation(s)
- V Mak
- Division of Urology, Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
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