Cell adhesion targets
“[The] proteins and signaling cascades that regulate adhesion between testicular cells have been largely delineated. These findings have unveiled a number of potential "druggable" targets that can be used to induce premature release of germ cells from the seminiferous epithelium, resulting in transient infertility.”
Anchoring Junctions As Drug Targets: Role in Contraceptive Development.
Mruk DD, Silvestrini B, Yan Cheng C.
Pharmacol Rev. 2008 May 15. [Epub ahead of print]
PMID: 18483144
“In this study, we sought to investigate the effect of Adjudin on the oxidative status of mammalian testis… results show that there is an induction of oxidative stress accompanying adherens junction restructuring which suggests a role for reactive oxygen species in the regulation of these testicular junctions. However, transient elevation in reactive oxygen species levels did not affect androgen transport.”
Adjudin-mediated germ cell depletion alters the anti-oxidant status of adult rat testis.
Sarkar O, Mathur PP.
Mol Reprod Dev. 2008 Apr 30. [Epub ahead of print]
PMID: 18449895
Endocrinological approaches
A summary of the male hormonal contraceptive clinical trials with a focus on the types and delivery routes of androgens used. Also summarizes the avenues explored in the non-response mystery: 5α-reductase inhibition, CAG repeats in the androgen receptor gene and CYP3A4 polymorphisms bear no clear relationship to continued spermatogenesis in men with severely depressed gonadotropins. A prospective trial including an INSL3 antagonist would provide another piece of the non-response puzzle.
Progress and prospects in male hormonal contraception.
Amory JK.
Curr Opin Endocrinol Diabetes Obes. 2008 Jun;15(3):255-60.
PMID: 18438174
Supporting endocrinological research
A “report that testosterone does increase Insl3 mRNA levels in a Leydig cell line and in primary Leydig cells. We also show that testosterone activates the activity of the Insl3 promoter from different species… We have mapped the testosterone-responsive element to the proximal Insl3 promoter region. This region, however, lacks a consensus androgen response element suggesting an indirect mechanism of action.”
Antagonistic effects of testosterone and the endocrine disruptor MEHP on INSL3 transcription in Leydig cells.
Laguë E, Tremblay JJ.
Endocrinology. 2008 May 22. [Epub ahead of print]
PMID: 18499751
“Basal serum Inhibin-B values are significantly lower in men with azoospermia compared to controls. However, Inhibin-B is not superior to FSH in predicting the presence of sperm in testicular fine needle aspirate.”
Serum inhibin-B and follicle stimulating hormone as predictors of the presence of sperm in testicular fine needle aspirate in men with azoospermia.
Goulis DG, Polychronou P, Mikos T, Grimbizis G, Gerou S, Pavlidou V, Papanikolaou A, Tarlatzis BC, Bontis IN, Papadimas I.
Hormones ( Athens ). 2008 Apr-Jun;7(2):140-7.
PMID: 18477551
Immunological approaches
The “immunological function of Sertoli cells in the testis is poorly understood at molecular level… We have demonstrated that mouse Sertoli cells express TLR2, TLR3, TLR4 and TLR5 at relatively high levels.” In this study, Sertoli cell phagocytosis of apoptotic spermatocytes and residual bodies was stimulated by “TLR3, but not other TLRs.”
Expression patterns and functions of Toll-like receptors in mouse Sertoli cells.
Wu H, Wang H, Xiong W, Chen S, Tang H, Han D.
Endocrinology. 2008 May 22. [Epub ahead of print]
PMID: 18499758
“These results suggest that sperm [polymorphonuclear (PMN) granulocytes] originate from two regions: 1) the epididymis, where in small numbers and activated they may play a favorable role in sperm quality, and the 2) prostate, where their presence in large numbers, reflecting prostatitis, induces decreased secretion, especially of acid phosphatase.”
Paradoxical increase of sperm motility and seminal carnitine associated with moderate leukocytospermia in infertile patients.
Ziyyat A, Barraud-Lange V, Sifer C, Ducot B, Wolf JP, Soufir JC.
Fertil Steril. 2008 Apr 24. [Epub ahead of print]
PMID: 18439589
Motility/capacitation targets
“To investigate the physiological role of meichroacdin (MCA), we generated MCA-disrupted mutant mice; homozygous MCA mutant males were infertile, but females were not. Sperm was rarely observed in the caput epididymidis of MCA mutant males. However, little to no difference was seen in testis mass between wild-type and mutant mice. During sperm morphogenesis, elongated spermatids had retarded flagellum formation and increased phagocytosis by Sertoli cells. Immunohistochemical analysis revealed that MCA interacts with proteins located on the outer dense fibers of the flagellum.”
Meichroacidin containing the MORN motif is essential for spermatozoa morphogenesis.
Tokuhiro K, Hirose M, Miyagawa Y, Tsujimura A, Irie S, Isotani A, Okabe M, Toyama Y, Ito C, Toshimori K, Takeda K, Oshio S, Tainaka H, Tsuchida J, Okuyama A, Nishimune Y, Tanaka H.
J Biol Chem. 2008 May 3. [Epub ahead of print]
PMID: 18453535
“The association of β-microseminoprotein (MSMB) to the sperm surface, the inhibitor effect on the spontaneous acrosome reaction and the increased MSMB levels found in seminal plasma in subfertile men suggests a relationship between this protein and semen quality and a possible role in the process of fertilization.”
β-microseminoprotein in human spermatozoa and its potential role in male fertility.
Franchi N, Avendaño C, Molina R, Tissera A, Maldonado C, Oehninger S, Coronel C.
Reproduction. 2008 May 9. [Epub ahead of print]
PMID: 18469041
Epididymal targets
“The human epididymis may rely on OCTN2 for transporting L-Carnitine into the epididymal duct to promote sperm maturation. With the accumulation of information on OCTN2 in the human epididymis, OCTN2 will become a new molecular target for researches on male contraception.”
Expression of OCTN2 mRNA in the human epididymis and its significance. [Chinese]
Gong DM, Li Z, Zhu XB, Liu YL, Cao XR, Liu Y, Wang YX.
Zhonghua Nan Ke Xue. 2008 Mar;14(3):242-4.
PMID: 18488339
Semen parameter standardization
“To improve consistency of sperm count measurements in multicenter trials of male hormonal contraception, a method was developed for central analysis of sperm concentration. In this process, a novel method was developed for assessment of “azoospermia” (or better: low sperm concentrations). This method uses a large counting chamber (25 μL; Leja, Nieuw-Vennep, The Netherlands) in combination with fluorescent staining of DNA and fluorescence microscopy… These results underline the conclusion of Grimes and Lopez that, for valid interpretation, vague terminology should be abandoned, and semen analysis should be reported quantitatively.”
Within subject variance and estimating degrees of confidence that 0 sperm is the true value?
Kersemaekers W, Mommers E.
Fertil Steril. 2008 May;89(5):1277. No abstract available.
PMID: 18486665
Proteomic / genomic supporting research
Analysis of epididymosomes showed “146 different proteins… [with] western blot [showing] that the protein composition of epididymosomes differed from that characterizing prostasomes; membranous vesicles secreted by the prostate.” Microarray analysis of caput, corpus, and cauda epididymal protein synthesis showed that epididymosomes collected at the distal end were secreted in different segments.
Protein composition of human epididymosomes collected during surgical vasectomy reversal: a proteomic and genomic approach.
Thimon V, Frenette G, Saez F, Thabet M, Sullivan R.
Hum Reprod. 2008 May 14. [Epub ahead of print]
PMID: 18482993
“[Transgenic] Ctnnb1(tm1Mmt/+);Amhr2(tm3(cre)Bhr/+) mice were generated to obtain sustained activation of the WNT/CTNNB1 pathway in both Leydig and Sertoli cells… [Resultant] data suggest that the WNT/CTNNB1 pathway regulates Sertoli cell functions critical to their capacity to support spermatogenesis in the postnatal testis.”
Seminiferous Tubule Degeneration and Infertility in Mice with Sustained Activation of WNT/CTNNB1 Signaling in Sertoli Cells.
Boyer A, Hermo L, Paquet M, Robaire B, Boerboom D.
Biol Reprod. 2008 May 14. [Epub ahead of print]
PMID: 18480464
“Since DNA solution can be injected into the seminiferous tubule via the rete testis, similar to germ cell transplantation, it is easy to transfect expression vectors into various differentiated germ cells and supporting Sertoli cells with [electroporation]. Unfortunately, it is difficult to create transgenic animals using this method because of its low efficiency. However, gain- and loss-of-function assays, promoter assays, and tagged-protein behavior assays can be conducted with this technique, as in in vitro culture systems.”
Mammalian testis: A target of in vivo electroporation.
Yomgogida K.
Dev Growth Differ. 2008 May 13. [Epub ahead of print]
PMID: 18482405
“In addition to the centriolar localization during flagellogenesis, mouse TSKS and the TSSK2 kinase localized in the tail and acrosomal regions of mouse epididymal sperm, while TSSK2 was found in the equatorial segment, neck and the midpiece of human spermatozoa. TSSK2/TSKS is the first kinase/substrate pair localized to the centrioles of spermatids and spermatozoa.”
TSKS concentrates in spermatid centrioles during flagellogenesis.
Xu B, Hao Z, Jha KN, Zhang Z, Urekar C, Digilio L, Pulido S, Strauss JF 3rd, Flickinger CJ, Herr JC.
Dev Biol. 2008 Apr 11. [Epub ahead of print]
PMID: 18495105
Heat-based approaches
“Decreased expression of LHR and 3beta-HSD and increased expression of aromatase in the cryptorchid testes suggest that hormonal imbalance was caused both by reduced testosterone synthesis and by increased androgen aromatisation. Impaired expression of Cx43 in the seminiferous tubules as well as in the interstitial tissue of the cryptorchid horse indicates that cryptorchidism affects intercellular communication in the testes.”
The effects of cryptorchidism on the regulation of steroidogenesis and gap junctional communication in equine testes.[Polish]
Hejmej A, Bilińska B.
Endokrynol Pol. 2008;59(2):112-118.
PMID: 18465685
Return to the top
With funding tight for conference travel these days and US visitor visas difficult for non-Europeans to obtain, researchers in the US and overseas have few opportunities to meet each other and learn firsthand about their colleagues' research. This month we begin a series on male contraceptive leads beyond the US borders, beginning with Carica papaya extracts, under study by Prof. N.K. Lohiya, FNASc, FAMS, in Jaipur, India.
Originally native to Latin America, the papaya is now cultivated in most countries with tropical climates. The fruit is widely used for food. The plant produces a latex sap rich in the enzyme papain, a protease that tenderizes meat and other proteins. Both the green fruit and the sap have multiple additional medicinal uses, including folk remedies for contraception and induced abortion. Medical research in adult male langur monkeys has confirmed the contraceptive capabilities of papaya.
Q: How does it work as a male contraceptive?
Prof. N.K. Lohiya: We have been conducting research to establish the male contraceptive potential of the seeds of Carica papaya, using various solvents and extraction procedures in the order of polarity. The chloroform extract, and [various purified subfractions] have shown results leading to male contraceptive effects in rats, rabbits and langur monkeys. The mode of action appears to be species- and extract-specific, showing testicular and post-testicular effects (i.e. either results in total sperm motility inhibitory effect, or azoospermia). The effects are free of systemic toxicity and are reversible.
Q: What is the next step in this research?
Prof. Lohiya: We have established the contraceptive potential of the seed products of Carica papaya in all three animal models tested. Safety of the [drug] has also been investigated by acute, sub-chronic, chronic, and carcinogenicity tests. Developmental toxicity and teratogenic potential of the drug are in progress. However, in plant research, identification of the active principle of the test material for mass production and for reproducibility of the results is essential. Our current research is focused on identifying the active principle.
Q: What is your biggest hurdle or concern?
Prof. Lohiya: One of the major hurdles in plant research is the reproducibility of the results. A plant that has shown to be effective in [folk medicine] and [has been used] for centuries may not be effective in animal models. In many cases the results vary from no activity to 100% activity with the same plant. Proper recording of time and place of collection, proper authentification of plants, formulation of uniform protocol for extraction and other trials may help in identifying the plant products with fertility regulation properties.
Q: What other contraceptive research areas are you working on?
Prof. Lohiya: A successful non-invasive reversal to normal, functional spermatozoa has been demonstrated in azoospermic RISUG-injected langur monkeys. An exploratory feasibility trial of a male spacing method in langur monkeys by repeated vas occlusion and non-invasive reversal has also been successfully demonstrated by us for the first time in male contraceptive research. The procedure may offer the feasibility of total non-invasive reversible vas occlusion by no scalpel injection and non-invasive reversal. The feasibility of the procedure in the human situation is awaiting clearance from the [relevant] drug regulatory agencies. We are currently investigating possible developmental and teratological effects in F 1 and F 2 generation following RISUG reversal with DMSO or NaHCO 3.
Q: What would most help your contraceptive research move forward?
Prof. Lohiya: Technical, infrastructure, and financial inputs would help us to characterize the seed products and would facilitate our efforts towards developing a contraceptive pill of plant origin.
Return to the top
Citizens of both developed and developing countries have a need for new family planning options, and emerging male contraceptives will be an important piece of improved global reproductive health. A series of recent research publications provide the statistics to back up the assertion of a global need for improved contraceptives.
The Guttmacher Institute found that 3.1 million unplanned pregnancies occur yearly in the US. Method failure accounted for almost half of the unplanned pregnancies. Forty-three percent of those pregnancies occured in women whose contraceptive use was inconsistent or incorrect, while 5% “were in women whose contraceptive method was used correctly but failed.” There is room for improvement in method counseling and use — and in the range of methods available.
The need for better family planning options among adolescent women and men is global. United Nations’ statistics on global fertility trends show that adolescent birth rates in developed countries range “between 4.9 and 43.0 births per 1000 women aged 15-19,” with a much wider range of 2.2 to 200.1 births per 1000 adolescent women in developing countries. While the US has an anomolously high rate of 43 adolescent births per 1000, a recent drop this rate shows change is possible. The majority of this decline is attributed to increased use of contraception.
Among couples of all ages, the Population Reference Bureau projects that demand for contraception will grow in the coming years. Their new data chalks up this increasing demand to “two trends: the burgeoning numbers of young people entering childbearing age and the increasing adoption of contraceptive use.” These trends are acting at different rates in various regions, and the resultant growth in demand “will be especially strong in some countries.”
Keep these references handy for when you need to justify the importance of your work!
Read more:
• Guttmacher Insititute’s Improving Contraceptive Use In the United States
• BMJ’s “Problems with contraception play big part in unplanned pregnancies, study says”
• United Nations’ World Fertility Patterns
• Population Reference Bureau’s Family Planning Worldwide
Return to the top
The National Institute of Child Health and Human Development announces an R-01 request for applications for collaborative reproductive health research between Indian and US scientists. Grants can be funded for $250,000 per year for 4 years.
The “Indo-US program on Contraception and Reproductive Health Research (CRHR) Joint Working Group continues to emphasize the need for more ‘translational’ types of research intended to move from basic science and discovery to product development and delivery… Emphasis should be placed on candidate methods and approaches to family planning that have achieved a level of development that would make them ideal candidates to move to the delivery/ implementation phase.
“Towards that end, the CRHR program seeks a balance among: 1) R&D of totally new male and female focused methods (hormonal, non-hormonal and/or barrier); 2) studies of approaches to increase the acceptability, access and utilization of currently available methods of family planning in at-risk populations of men, women and couples; and 3) efforts to incrementally improve existing methods, i.e., make what is already available, better.”
The deadline to submit a letter of intent is July 11, 2008. For eligibility criteria and detailed application instructions, see RFA-HD-08-024.
Return to the top
On the occasion of an Australian engineer announcing his idea for a radio-controlled sperm blocker, the June issue of Popular Science includes a brief piece on several other non-hormonal male contraceptives in the works — all of which are reality, not just a concept. “The idea is to stop sperm at one localized site, rather than using hormones that can affect heart function, weight and cholesterol levels,’ reports Cliff Kuang, who picks clever nicknames and eye-catching graphics to describe RISUG (“Drano”), the IVD, and ultrasound (“contraception could become a twice-yearly checkup procedure, like going to the dentist”).
Beyond the Male “Pill”: From remote-control key fobs to ultrasound, male contraception goes high tech
Popular Science, June 2008
The Los Angeles Times covers the hormonal research meta-analysis by UCLA team Drs. Ron Swerdloff and Christina Wang, and asks men to weigh in with their opinion. “‘The concept has been validated,’ says Swerdloff. ‘We are convinced that new alternatives for family planning are needed. But a product is not yet ready to go to market.’ Why not? Perhaps pharmaceutical companies are on the sidelines because they don't think men are enthusiastic about controlling their own fertility. What do you say, men?”
Male contraception almost ready. Are men?
Los Angeles Times, 1 May
Additional Southern California papers profile Drs. Wang and Swerdloff. “A study compiled by two Torrance-area scientists — a married couple who head one of only two government-funded research centers in the United States for male contraceptives -- found that hormone pills that block sperm production in men are safe and reversible. ‘There is more of an awareness that the responsibility in family planning should be a shared responsibility…’”
Local experts tout male birth control
Daily Breeze, 29 April
Oklahoma newspapers feature Oklahoma Medical Research Foundation scientist Dr. Kevin Moore and his knockout work on two closely-related enzymes, tyrosylprotein sulfotransferases (TPST) 1 and 2. Mice lacking the TPST-2 enzyme are infertile due to impaired sperm-egg binding. “Though promising, Moore’s male contraceptive is years from human testing. He has started a new drug discovery company called Siwa Biotech Corporation and has begun searching for a compound to inhibit the production of TPST-2. He said that his team has narrowed thousands of contenders to about 150 possible options and that he may be able to narrow those down to a good candidate by next week.”
City research may lead to ‘the pill’ for men
NewsOK.com, 29 April
Journalist Amy Crawford writes a well-researched piece covering the new retinoic acid receptor antagonist research at Columbia University, and clarifying the struggles faced by hormonal researchers — in addition to mentioning suspensories, RISUG, and the IVD. Quotes from Drs. Debra Wolgemuth, Ron Swerdloff, John Amory, and MCIP's director Elaine Lissner address both technical challenges and societal readiness. “Though they didn't look like much, the white specks squirming under a microscope in researcher Debra Wolgemuth's lab could have a big impact in the high-stakes world of controlling fertility — not for women, but for men… ‘In the past 30 to 40 years,’ said Lissner, ‘there's been a societal shift in the responsibility men take for reproduction. It takes time for science and money to catch up, so it's only been in the last five to 10 years that this [field] has taken off.’” Written for the Columbia News Service, a wire put out by Columbia Journalism School and the New York Times Company, this article was also syndicated in other papers around the country.
Scientists say male contraceptive is closer than ever
Vermont Sunday Magazine, 18 May
College papers continue to cover male contraception and interview students to guage their interest in new methods. “The responsibility of birth control has fallen on females since its invention. But a range of birth control methods now being tested suggest that society is putting more responsibility on males when it comes to using protection…”
Birth control everyone's responsibility
OSU - The Lantern, 15 May
Return to the top
