Have scientists uncovered an alternative to condoms and vasectomies?

Good news! Hopefully, finally men have better options too! However, this is very early research!

Gender equality in contraceptives!

That men have been so dependent for so many years on women to effectively control reproduction without interfering with the joy of sex was hard to swallow (pardon my pun).

"... surveys show most American men are interested in using male contraceptives, yet they have almost no options. Recent attempts to develop drugs that block sperm production, maturation, or fertilization have had limited success, providing incomplete protection or severe side effects. New approaches to male contraception are needed, but because sperm development is so complex, researchers have struggled to identify parts of the process that can be safely and effectively tinkered with.

Now, scientists at the Salk Institute in California have found a new method of interrupting sperm production that is both non-hormonal and reversible. The study, just published in Proceedings of the National Academy of Sciences under the title “Targeting nuclear receptor corepressors for reversible male contraception,” has found a  new protein complex in regulating gene expression during sperm production. The researchers demonstrate that treating male mice with an existing class of drugs called HDAC (histone deacetylase) inhibitors can interrupt the function of this protein complex and block fertility without affecting libido.  ...

Salk scientists found that for this to work, retinoic acid receptors must bind with a protein called SMRT (silencing mediator of retinoid and thyroid hormone receptors) that then recruits HDACs, and this complex of proteins goes on to synchronize the expression of genes that produce sperm. ..."

From the significance and abstract:

"Significance

With unintended pregnancies costing billions of dollars a year in the United States alone, the socioeconomic and health benefits of improved birth control cannot be overemphasized. Despite the pressing need for population control, male contraceptive options are limited. These rodent studies demonstrate reversible male contraception by targeting silencing mediator of retinoid and thyroid hormone receptors-retinoid acid receptor signaling to identify a non-hormonal approach to male contraception.

Abstract

Despite numerous female contraceptive options, nearly half of all pregnancies are unintended. Family planning choices for men are currently limited to unreliable condoms and invasive vasectomies with questionable reversibility. Here, we report the development of an oral contraceptive approach based on transcriptional disruption of cyclical gene expression patterns during spermatogenesis. Spermatogenesis involves a continuous series of self-renewal and differentiation programs of spermatogonial stem cells (SSCs) that is regulated by retinoic acid (RA)–dependent activation of receptors (RARs), which control target gene expression through association with corepressor proteins. We have found that the interaction between RAR and the corepressor silencing mediator of retinoid and thyroid hormone receptors (SMRT) is essential for spermatogenesis. In a genetically engineered mouse model that negates SMRT-RAR binding (SMRTmRID mice), the synchronized, cyclic expression of RAR-dependent genes along the seminiferous tubules is disrupted. Notably, the presence of an RA-resistant SSC population that survives RAR de-repression suggests that the infertility attributed to the loss of SMRT-mediated repression is reversible. Supporting this notion, we show that inhibiting the action of the SMRT complex with chronic, low-dose oral administration of a histone deacetylase inhibitor reversibly blocks spermatogenesis and fertility without affecting libido. This demonstration validates pharmacologic targeting of the SMRT repressor complex for non-hormonal male contraception."

Have scientists uncovered an alternative to condoms and vasectomies? - The Jerusalem Post Salk Institute scientists discover new target for reversible, non-hormonal male birth control

Salk Scientists Discover New Target For Reversible, Non-Hormonal Male Birth Control Oral administration of HDAC inhibitor blocked sperm production and fertility in mice without affecting libido

Targeting nuclear receptor corepressors for reversible male contraception (no public access)

Sperm, pictured inside the cross-sectioned tube of the epididymis, were not generated while mice took the HDAC inhibitor drug (top right), but after 60 days off the drug, spermatogenesis was recovered (bottom right). The left column shows sperm at the same time points in a mouse that did not receive the drug.