J Physiol. 2012 Sep 1;590(Pt 17):4209-22..
ATP secretion in the male reproductive tract: essential role of CFTR.
Ruan YC, Shum WW, Belleannée C, Da Silva N, Breton S.
Source
Center for Systems Biology/Program in Membrane Biology/Nephrology Division, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114, USA.
Abstract
Extracellular ATP is essential for the function of the epididymis and spermatozoa, but ATP release in the epididymis remains uncharacterized.
We investigated here whether epithelial cells release ATP into the lumen of the epididymis, and we examined the role of the cystic fibrosis transmembrane conductance regulator (CFTR), a Cl(-) and HCO(3)(-) conducting ion channel known to be associated with male fertility, in this process. Immunofluorescence labelling of mouse cauda epididymidis showed expression of CFTR in principal cells but not in other epithelial cells. CFTR mRNA was not detectable in clear cells isolated by fluorescence-activated cell sorting (FACS) from B1-EGFP mice, which express enhanced green fluorescent protein (EGFP) exclusively in these cells in the epididymis. ATP release was detected from the mouse epididymal principal cell line (DC2) and increased by adrenaline and forskolin. Inhibition of CFTR with CFTR(inh172) and transfection with CFTR-specific siRNAs in DC2 cells reduced basal and forskolin-activated ATP release. CFTR-dependent ATP release was also observed in primary cultures of mouse epididymal epithelial cells. In addition, steady-state ATP release was detected in vivo in mice, by measuring ATP concentration in a solution perfused through the lumen of the cauda epididymidis tubule and collected by cannulation of the vas deferens. Luminal CFTR(inh172) reduced the ATP concentration detected in the perfusate.
This study shows that CFTR is involved in the regulation of ATP release from principal cells in the cauda epididymidis. Given that mutations in CFTR are a leading cause of male infertility, we propose that defective ATP signalling in the epididymis might contribute to dysfunction of the male reproductive tract associated with these mutations.
Comment in
Re: ATP secretion in the male reproductive tract: essential role of CFTR. [J Urol. 2013]

Int J Androl. 2012 Apr;35(2):109-24.
The role of mitochondria in energy production for human sperm motility.
Piomboni P, Focarelli R, Stendardi A, Ferramosca A, Zara V.
Source
Department of Biomedical Sciences, Applied Biology Section, University of Siena, Siena, Italy.
Abstract
Mitochondria of spermatozoa are different from the corresponding organelles of somatic cells, in both their morphology and biochemistry. The biochemical differences are essentially related to the existence of specific enzyme isoforms, which are characterized by peculiar kinetic and regulatory properties. As mitochondrial energy metabolism is a key factor supporting several sperm functions, these organelles host critical metabolic pathways during germ cell development and fertilization. Furthermore, spermatozoa can use different substrates, and therefore activate different metabolic pathways, depending on the available substrates and the physico-chemical conditions in which they operate. This versatility is critical to ensure fertilization success.
However, the most valuable aspect of mitochondria function in all types of cells is the production of chemical energy in the form of ATP which can be used, in the case of spermatozoa, for sustaining sperm motility.
The latter, on the other hand, represents one of the major determinants of male fertility. Accordingly, the presence of structural and functional alterations in mitochondria from asthenozoospermic subjects confirms the important role played by these organelles in energy maintenance of sperm motility. The present study gives an overview of the current knowledge on the energy-producing metabolic pathways operating inside human sperm mitochondria and critically analyse the differences with respect to somatic mitochondria. Such a comparison has also been carried out between the functional characteristics of human sperm mitochondria and those of other mammalian species.
A deeper understanding of mitochondrial energy metabolism could open up new avenues of investigation in bioenergetics of human sperm mitochondria, both in physiological and pathological conditions.
© 2011 The Authors. International Journal of Andrology © 2011 European Academy of Andrology.
PMID:21950496[PubMed – indexed for MEDLINE]

Soc Reprod Fertil Suppl. 2007;65:309-25.
Energy metabolism and sperm function.
Miki K.
Source
Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina 27599-7090, USA. miki@med.unc.edu
Abstract
Energy metabolism is a key factor supporting sperm function.
Sustaining sperm motility and active protein modifications such as phosphorylation could be the reason why sperm require exceptionally more ATP than other cells.
Many methods have been used to understand the relationship between energy metabolism and sperm function. These approaches have identified critical metabolic pathways that support specific processes during germ cell development and fertilisation. In round spermatids, lactate and pyruvate are the preferred substrates and the use of glucose is limited, however, during epididymal maturation sperm expand to use glycolysis. While the acrosome reaction requires lactate or pyruvate for ATP production by oxidative phosphorylation, gamete fusion requires glucose to produce NADPH by the pentose phosphate pathway. Sperm motility appears to be supported by relatively low ATP levels, but achievement of high ATP levels are essential for tyrosine phosphorylation linked to hyperactivation. Thus, each individual process and event requires a different substrate and metabolic pathway. Despite different preferences for energy substrates and metabolic pathways between species, analysis of knockout mice revealed that glycolysis is indispensable for mouse sperm function and that oxidative phosphorylation is not essential for male fertility. This suggests that glycolysis could compensate for the lack of oxidative phosphorylation and recover most sperm function. Spermatogenic cell-specific glycolytic enzymes may confer flexible use of substrates and adapt to unexpected conditions for substrates in the female reproductive tract.
PMID:17644971[PubMed – indexed for MEDLINE]

Andrologia. 2012 May;44 Suppl 1:586-9.
Adenosine deaminase activity in fertile and infertile men.
Rostampour F, Biglari M, Vaisi-Raygani A, Salimi S, Tavilani H.
Source
Department of Biochemistry, Medical School, Hamadan University of Medical Sciences, Hamadan,
Iran.
Abstract
Adenosine deaminase (ADA; E.C.3.5.4.4) catalyses the deamination of adenosine to inosine. In the human reproductive system, the importance of enzymes that affect metabolism of adenosine, particularly adenosine deaminase, has been noticed. The purpose of this study was to determine the plasma activities of total adenosine deaminase (ADAT), and its isoenzymes, ADA1 and ADA2, in fertile and infertile men. Plasma activities of ADA and its isoenzymes were measured in 55 fertile men and 70 infertile men. There was a significant difference in the ADA1 and ADA2 activities between fertile and infertile individuals (P < 0.01). The activity of ADAT, ADA2 and ADA1 in infertile men was higher than that in fertile individuals.
This alteration in ADA activity can lead to reduced adenosine levels, which may be involved in disturbing the fertility process.
© 2011 Blackwell Verlag GmbH.
PMID:21919946[PubMed – indexed for MEDLINE]

Mitochondrion. 2011 Sep;11(5):797-813.
Mitochondrial function in the human oocyte and embryo and their role in developmental competence.
Van Blerkom J.
Source
Department of Molecular, Cellular and Developmental Biology, The University of Colorado, Boulder, Colorado, USA. Jonathan.Vanblerkom@Colorado.EDU
Abstract
The role of mitochondria as a nexus of developmental regulation in mammalian oogenesis and early embryogenesis is emerging from basic research in model species and from clinical studies in infertility treatments that require in vitro fertilization and embryo culture.
Here, mitochondrial bioenergetic activities and roles in calcium homeostasis, regulation of cytoplasmic redox state, and signal transduction are discussed with respect to outcome in general, and as possible etiologies of chromosomal defects, maturation and fertilization failure in human oocytes, and as causative factors in early human embryo demise.
At present, the ability of mitochondria to balance ATP supply and demand is considered the most critical factor with respect to fertilization competence for the oocyte and developmental competence for the embryo. mtDNA copy number, the timing of mtDNA replication during oocyte maturation, and the numerical size of the mitochondrial complement in the oocyte are evaluated with respect to their relative contribution to the establishment of developmental competence.
Rather than net cytoplasmic bioenergetic capacity, the notion of functional compartmentalization of mitochondria is presented as a means by which ATP may be differentially supplied and localized within the cytoplasm by virtue of stage-specific changes in mitochondrial density and potential (ΔΨm).
Abnormal patterns of calcium release and sequestration detected at fertilization in the human appear to have coincident effects on levels of mitochondrial ATP generation.
These aberrations are not uncommon in oocytes obtained after ovarian hyperstimulation for in vitro fertilization.
The possibility that defects in mitochondrial calcium regulation or bioenergetic homeostasis could have negative downstream development consequences, including imprinting disorders, is discussed in the context of signaling pathways and cytoplasmic redox state.
Copyright © 2010 Elsevier B.V. and Mitochondria Research Society. All rights reserved.
PMID:20933103[PubMed – indexed for MEDLINE]

Singapore Med J. 2009 Apr;50(4):336-47.
Genetics of human male infertility.
Poongothai J, Gopenath TS, Manonayaki S.
Source
Computational Engineering and Networking Department, Amrita Viswha Vidyapeetham, Ettimadai, Coimbatore 638107, Tamil Nadu, India. poongothai_jp@yahoo.co.in
Abstract
Infertility is defined as a failure to conceive in a couple trying to reproduce for a period of two years without conception. Approximately 15 percent of couples are infertile, and among these couples, male factor infertility accounts for approximately 50 percent of causes. Male infertility is a multifactorial syndrome encompassing a wide variety of disorders. In more than half of infertile men, the cause of their infertility is unknown (idiopathic) and could be congenital or acquired. Infertility in men can be diagnosed initially by semen analysis. Seminograms of infertile men may reveal many abnormal conditions, which include azoospermia, oligozoospermia, teratozoospermia, asthenozoospermia, necrospermia and pyospermia. The current estimate is that about 30 percent of men seeking help at the infertility clinic are found to have oligozoospermia or azoospermia of unknown aetiology. Therefore, there is a need to find the cause of infertility. The causes are known in less than half of these cases, out of which genetic or inherited disease and specific abnormalities in the Y chromosome are major factors. About 10-20 percent of males presenting without sperm in the ejaculate carry a deletion of the Y chromosome. This deleted region includes the Azoospermia Factor (AZF) locus, located in the Yq11, which is divided into four recurrently deleted non-overlapping subregions designated as AZFa, AZFb, AZFc and AZFd. Each of these regions may be associated with a particular testicular histology, and several candidate genes have been found within these regions. The Deleted in Azoospermia (DAZ) gene family is reported to be the most frequently deleted AZF candidate gene and is located in the AZFc region. Recently, a partial, novel Y chromosome 1.6-Mb deletion, designated “gr/gr” deletion, has been described specifically in infertile men with varying degrees of spermatogenic failure. The DAZ gene has an autosomal homologue, DAZL (DAZ-Like), on the short arm of the chromosome 3 (3p24) and it is possible that a defective autosomal DAZL may be responsible for the spermatogenic defect. The genetic complexity of the AZF locus on the long arm of the Y chromosome could be revealed only with the development of sequence tagged sites. Random attacks on the naked mitochondrial DNA (mtDNA) of sperm by reactive oxygen species or free radicals will inevitably cause oxidative damage or mutation to the mitochondrial genome with pathological consequences and lead to infertility in males. The key nuclear enzyme involved in the elongation and repair of mtDNA strands is DNA polymerase gamma, mapped to the long arm of chromosome 15 (15q25), and includes a CAG repeat region.
Its mutation affects the adenosine triphosphate production.
The introduction of molecular techniques has provided great insight into the genetics of infertility. Yet, our understanding of the genetic causes of male infertility remains limited.
PMID:19421675[PubMed – indexed for MEDLINE]

Reprod Sci. 2007 Oct;14(7):655-66.
Effects of extracellular adenosine 5′-triphosphate on human sperm motility.
Edwards SE, Buffone MG, Knee GR, Rossato M, Bonanni G, Masiero S, Ferasin S, Gerton GL, Moss SB, Williams CJ.
Source
Center for Research on Reproduction & Women’s Health, Department of Obstetrics & Gynecology, University of Pennsylvania, Philadelphia, PA, USA.
Abstract
Extracellular adenosine 5′-triphosphate (ATP) previously has been shown to increase the fertilization percentage in human in vitro fertilization (IVF) performed for male factor infertility.
The objective of this study is to determine the effects of extracellular adenosine 5′-triphosphate (ATPe) on human sperm function by examining its effects on end points of sperm capacitation. Sperm obtained from healthy volunteers with normal semen parameters, asthenozoospermic men, and cryopreserved samples were incubated in medium with or without 2.5 mM ATPe. The effects of ATPe on acrosomal exocytosis, protein tyrosine phosphorylation, and sperm motility parameters were quantified. Although ATPe did not affect acrosomal exocytosis or protein tyrosine phosphorylation in sperm from healthy donors, it significantly altered several motility parameters, with the largest effects manifested in increased curvilinear velocity and percentage hyperactivation. ATPe similarly affected sperm selected for poor motility and thawed cryopreserved sperm but to a lesser extent than its effects on sperm with normal motility. ATPe increased straight-line velocity and linearity of sperm obtained from asthenozoospermic men. Human sperm motility characteristics are altered by ATPe; this finding may explain its previously reported beneficial effect on human IVF.
These results suggest that ATPe could constitute a new therapeutic modality in the treatment of male infertility.
PMID:18000227[PubMed – indexed for MEDLINE]

Biol Reprod. 2008 Jul;79(1):164-71.
Extracellular adenosine 5′-triphosphate alters motility and improves the fertilizing capability of mouse sperm.
Rodríguez-Miranda E, Buffone MG, Edwards SE, Ord TS, Lin K, Sammel MD, Gerton GL, Moss SB, Williams CJ.
Source
Department of Obstetrics & Gynecology, Center for Research on Reproduction & Women’s Health, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Abstract
Extracellular adenosine 5′-triphosphate (ATPe) treatment of human sperm has been implicated in improving in vitro fertilization (IVF) results.
We used the mouse model to investigate mechanisms of action of ATPe on sperm. ATPe treatment significantly enhanced IVF success as indicated by both rate of pronuclear formation and percentage cleavage to the 2-cell stage. However, ATPe did not increase the percentage of sperm undergoing spontaneous acrosomal exocytosis nor change the pattern of protein tyrosine phosphorylation normally observed in capacitated sperm. ATPe altered sperm motility parameters; in particular, both noncapacitated and capacitated sperm swam faster and straighter. The percentage of hyperactivated sperm did not increase in capacitated ATPe-treated sperm compared to control sperm. ATPe induced a rapid increase in the level of intracellular calcium that was inhibited by two distinct P2 purinergic receptor inhibitors, confirming that these receptors have an ionotropic role in sperm function.
The observed motility changes likely explain, in part, the improved fertilizing capability when ATPe-treated sperm were used in IVF procedures and suggest a mechanism by which ATPe treatment may be beneficial for artificial reproductive techniques.
PMID:18401012[PubMed – indexed for MEDLINE]

Fertil Steril. 1998 Mar;69(3):533-8.
Absence of cyclic adenosine 3′:5′ monophosphate responsive element modulator expression at the spermatocyte arrest stage.
Lin WW, Lamb DJ, Lipshultz LI, Kim ED.
Source
Baylor College of Medicine, Houston, Texas, USA.
Abstract
OBJECTIVE:
To test the hypotheses that variations in the expression of adenosine 3′:5′ monophosphate (cAMP) responsive element modulator are found in human seminiferous epithelium in men with impaired testicular function and subsequent infertility and that variations in apoptosis frequency are associated with differential cAMP responsive element modulator expression in male infertility states.
DESIGN:
Standard immunohistochemical staining using a rabbit polyclonal antibody against the tau isoform of the cAMP responsive element modulator protein was performed on 5-microM sections of Bouin’s fixed, paraffin-embedded testicular tissue obtained from azoospermic or severely oligozoospermic men for routine clinical purposes. Histologic diagnosis was confirmed with computerized image analysis of Feulgen-stained sections.
SETTING:
Tertiary male infertility referral center at a medical school.
PATIENT(S):
Forty-eight testis biopsies were performed in 38 azoospermic or severely oligozoospermic males.
INTERVENTION(S):
Rabbit polyclonal cAMP responsive element modulator tau antibody was applied to the paraffin-embedded testis sections.
MAIN OUTCOME MEASURE(S):
Testis immunoreactivity to polyclonal cAMP responsive element modulator tau antibody and apoptotic indices.
RESULT(S):
Although cAMP responsive element modulator immunoreactivity was present in the round spermatid stage of meiosis in testis biopsy specimens showing normal spermatogenesis, spermatid maturation arrest, and hypospermatogenesis, there was complete absence of expression in biopsy specimens from patients with Sertoli cell only and spermatocyte maturation arrest states. In addition, significantly increased apoptotic indices were observed in the spermatocyte maturation arrest state in comparison with normal spermatogenesis and Sertoli cell only pattern.
CONCLUSION(S):
These data suggest that cAMP responsive element modulator may be important for spermatid development and a stage-specific regulator of human spermatogenesis.
Absence of cAMP responsive element modulator may be a cause of testicular failure in various types of male infertility.
PMID:9531892[PubMed – indexed for MEDLINE]

Int J Androl. 2012 Apr;35(2):133-44.
Effects of polydeoxyribonucleotide on the histological damage and the altered spermatogenesis induced by testicular ischaemia and reperfusion in rats.
Minutoli L, Antonuccio P, Squadrito F, Bitto A, Nicotina PA, Fazzari C, Polito F, Marini H, Bonvissuto G, Arena S, Morgia G, Romeo C, Caputi AP, Altavilla D.
Source
Section of Pharmacology, Department of Experimental and Clinical Medicine and Pharmacology, University of Messina, Messina, Italy. lminutoli@unime.it
Abstract
The effects of polydeoxyribonucleotide (PDRN), an agonist of the A2A adenosine receptors which when activated positively influences sperm activity, were tested in an experimental testicular ischaemia/reperfusion injury model. Anaesthetized male Sprague-Dawley rats were subjected to testicular torsion-induced ischaemia, followed by reperfusion (TI/R). Immediately after detorsion, randomized animals, including SHAM, received intraperitoneal injections of: (i) vehicle (1 mL/kg 0.9% NaCl solution); (ii) PDRN (8 mg/kg); (iii) DMPX (3,7-dimethyl-1-propargilxanthine, 0.1 mg/kg); or (iv) PDRN (8 mg/kg) + DMPX (0.1 mg/kg). Animals were euthanized at 1, 7 and 30 days following reperfusion. Vascular endothelial growth factor (VEGF) expression is normally associated with adenosine A2A receptor stimulation. After treatment, VEGF mRNA/protein expression quantified by qPCR and Western blot, vascular endothelial growth factor receptor-1 (VEGFR1) and endothelial nitric oxide synthase (eNOS) mRNA measured by qPCR, VEGF and VEGFR1 assessed using immunohistochemical methods, histological staining and spermatogenic activity were all analysed. Testis ischaemia-reperfusion (TI/R) injury caused increases in VEGF mRNA and protein, VEGFR1 and eNOS mRNA, histological damage and reduced spermatogenic activity. Immunostaining showed a lower expression of VEGF in germinal epithelial cells and a strong expression of VEGFR1 in Leydig cells after TI/R. PDRN administration increased significantly VEGF message/protein, VEGFR1 and eNOS message, decreased histological damage and ameliorated spermatogenic activity.
PDRN might be useful in the management of testicular torsion.
© 2011 The Authors. International Journal of Andrology © 2011 European Academy of Andrology.
PMID:21651579[PubMed – indexed for MEDLINE]
( polydeoxyribonucleotide: mixture of fractions of nucleotides by DNA)