The biology of human male reproduction: An overview

In most mammalian species aromatase is encoded by a single gene ( Cyp19 ), which contains 18 exons, nine of them being translated. In man, the presence of a biologically active aromatase and oestrogen receptors (ERα and ERβ) has been reported in Leydig cells, and also in immature germ cells and ejaculated spermatozoa. Concerning aromatase, the amount of transcript and enzymatic activity are decreased in immotile compared with motile sperm. We have amplified aromatase mRNA by real-time polymerase chain reaction in spermatozoa from asthenospermic, teratospermic and asthenoteratospermic men and recorded, respectively, 44, 52 and 67 per cent decreases of the amount of transcripts compared with fertile donors. A high degree of correlation ( r = −0.64) between the abnormal spermatozoa (especially microcephaly and acrosome malformations) and aromatase/GAPDH transcript ratio has been observed. Idiopathic infertility is a wide health problem and no treatment is currently available. In humans, even if the role of oestrogens in spermatogenesis is still a matter of debate, the observations of decreased sperm number and motility in men genetically deficient in aromatase, together with our data and those reported in the literature, may suggest a role for aromatase/oestrogens not only during the development and maintenance of spermatogenesis but also in the final maturation of spermatozoa.

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The highly conserved NANOS2 protein: testis-specific expression and significance for the human male reproduction

MHR Basic science of reproductive medicine ◽

10.1093/molehr/gap003 ◽

2009 ◽

Vol 15 (3) ◽

pp. 165-171 ◽

Cited By ~ 39

Author(s):

K.M. Kusz ◽

L. Tomczyk ◽

M. Sajek ◽

A. Spik ◽

A. Latos-Bielenska ◽

...

Keyword(s):

Male Reproduction ◽

Specific Expression ◽

Human Male ◽

Testis Specific Expression

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Human sperm anatomy and endocrinology in varicocele: role of androgen receptor

Reproduction ◽

10.1530/rep-13-0542 ◽

2014 ◽

Vol 147 (5) ◽

pp. 589-598 ◽

Cited By ~ 7

Author(s):

Carmela Guido ◽

Marta Santoro ◽

Francesca De Amicis ◽

Ida Perrotta ◽

Salvatore Panza ◽

...

Keyword(s):

Androgen Receptor ◽

Molecular Mechanisms ◽

Human Sperm ◽

Pi3k Pathway ◽

Male Reproduction ◽

Male Gametes ◽

Human Male ◽

Normal Sperm ◽

Triglyceride Content ◽

Glucose 6 Phosphate Dehydrogenase

The study of androgens involved in male reproduction has been object of intense efforts, while their reported action on human male gametes is limited. We previously described the presence of androgen receptor (AR) in sperm with a role related to the modulation of the PI3K pathway. In the present study, we investigated the expression of AR and its ultrastructural location in normal sperm as well as in spermatozoa obtained from varicocele patients. We observed a reduced AR content in varicocele sperm with respect to healthy sperm by western blot analysis and transmission electron microscopy (TEM). The ultrastructural location of AR was detected mainly on the head membrane as well as in the nucleus, neck, and mitochondria. Influence of dihydrotestosterone (DHT) treatment on cholesterol efflux was increased in normal sperm, while it was reduced or absent in varicocele sperm. To better understand DHT/AR significance in human male gametes, we evaluated triglyceride content and lipase, acyl-CoA dehydrogenase, and glucose-6-phosphate dehydrogenase activities upon DHT treatment. The metabolic outcome glimpsed in normal sperm was an increased metabolic rate, while ‘varicocele’ sperm economized energy. Taken together, our results reveal DHT and AR as new players in sperm endocrinology, indicating that varicocele sperm may have difficulty in switching to the capacitated status. A decreased AR expression and a consequent reduced responsiveness to DHT in sperm may represent molecular mechanisms involved in the pathophysiology of varicocele leading to male infertility. This study revealed new detrimental effects of varicocele on sperm at the molecular level.

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The pathophysiology and genetics of human male reproduction

Male Infertility ◽

10.3109/9780203090626-5 ◽

2007 ◽

pp. 35-48

Author(s):

Christiaan Hoogendijk ◽

Ralf Henkel

Keyword(s):

Male Reproduction ◽

Human Male

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Prostasomes—their effects on human male reproduction and fertility

Human Reproduction Update ◽

10.1093/humupd/dmi052 ◽

2005 ◽

Vol 12 (3) ◽

pp. 283-292 ◽

Cited By ~ 58

Author(s):

H.P. Burden ◽

C.H. Holmes ◽

R. Persad ◽

K. Whittington

Keyword(s):

Male Reproduction ◽

Human Male

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Two Y Genes Can Replace the Entire Y Chromosome for Assisted Reproduction in the Mouse

Science ◽

10.1126/science.1242544 ◽

2013 ◽

Vol 343 (6166) ◽

pp. 69-72 ◽

Cited By ~ 44

Author(s):

Yasuhiro Yamauchi ◽

Jonathan M. Riel ◽

Zoia Stoytcheva ◽

Monika A. Ward

Keyword(s):

Male Infertility ◽

Y Chromosome ◽

Assisted Reproduction ◽

Germ Cells ◽

Male Reproduction ◽

Fetal Life ◽

Human Male ◽

Determinant Factor ◽

Spermatogonial Proliferation ◽

Live Mouse

The Y chromosome is thought to be important for male reproduction. We have previously shown that, with the use of assisted reproduction, live offspring can be obtained from mice lacking the entire Y chromosome long arm. Here, we demonstrate that live mouse progeny can also be generated by using germ cells from males with the Y chromosome contribution limited to only two genes, the testis determinant factorSryand the spermatogonial proliferation factorEif2s3y.Sryis believed to function primarily in sex determination during fetal life.Eif2s3ymay be the only Y chromosome gene required to drive mouse spermatogenesis, allowing formation of haploid germ cells that are functional in assisted reproduction. Our findings are relevant, but not directly translatable, to human male infertility cases.

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The pathophysiology and genetics of human male reproduction

Male Infertility ◽

10.3109/9780203090626-11 ◽

2007 ◽

pp. 63-76 ◽

Cited By ~ 2

Keyword(s):

Male Reproduction ◽

Human Male

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Air pollutants and impairments of male reproductive health-an overview

Reviews on Environmental Health ◽

10.1515/reveh-2020-0136 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Sunil Kumar ◽

Anupama Sharma ◽

Riddhi Thaker

Keyword(s):

Air Pollution ◽

Reproductive Health ◽

Indoor Air ◽

Air Pollutants ◽

Semen Quality ◽

Ambient Air ◽

Quality Parameters ◽

Male Reproduction ◽

Human Male ◽

Male Reproductive Health

Abstract Excessive air pollution, both ambient and indoor are might be detrimental to human wellbeing and are related to morbidity and mortality, it may also affect the reproductive function and its outcome. It is a recognized fact that air pollution contains several toxicants, gases, particulate matter, toxic metals etc. Some of them might affect reproductive and developmental process and a few are persistent. The information accessible on air pollution to human male reproduction is stated to affect semen quality by diminishing one or more sperm quality parameters i.e., sperm morphology, concentration, motility etc. and may causes sperm DNA damage, these might alter the fertility potential which in turn affect pregnancy or its outcome. The impact might be related to the pollutant’s concentration and duration of exposure. The data on impact of air contamination on endocrine function are inadequate, inconsistence and the diversity of existence of air contaminants in area to area and multiplicity in semen quality parameters assessed in various studies as well as study design variables complicated the problem of evaluation of impact of air pollution on male reproduction. The data available suggests the air pollution is might be injurious to human male reproductive health, which depends upon amounts of air pollutants in the air, duration of exposure etc. but more comprehensive data are needed to substantiate the findings. The data are also needed on indoor air pollution on reproduction as people are might be subjected to greater quantities of some of the indoor air pollutants as compared to ambient air pollution.

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