Reproductive Health

Why we need to make more of an effort to understand sperm

Sperm are the key to the future of fertility – and contraception.

Despite the huge global demand for both fertility treatment and contraception, there are surprisingly few options to boost male fertility, or for male contraception. To have more options, we really need a better understanding of how human sperm work. Unfortunately, they are incredibly difficult to study in the lab.

Not only are sperm the smallest cells in the body (25 times smaller than a grain of sand), they are unique and highly specialised, designed to survive outside the body. Unlike other cells, sperm contain virtually no cytoplasm – the jelly-like fluid that fills a cell and stores many of the chemicals that are essential for life. Instead they interact with the surrounding environment to inform their behaviour. Their internal chemical messages and signals are also different to those of other cells, meaning we can’t make assumptions about how they work and many standard cell research techniques can’t be applied in the lab. It’s little wonder then that research in the field of male fertility and contraception is limited.

Growing infertility

Infertility is estimated to affect about one in seven couples of reproductive age in the United Kingdom. Male fertility problems are increasingly common. However, our limited understanding of how sperm work and the requirements needed to achieve fertilisation, means that we struggle to treat this problem.

Incredibly, there is no drug that an infertile man can take, or that can be added to his sperm in a laboratory to improve how sperm swim or work. Instead couples rely on treatments such as in vitro fertilisation or IVF and intracytoplasmic sperm injection or ICSI, which are expensive, invasive, and not guaranteed to succeed. Nonetheless, the number of people seeking IVF and ICSI treatment is increasing each year.

Although access to female contraception varies considerably across the globe, use of male methods (condoms, vasectomy) is consistently low. There has been no significant innovation in available male contraception in the past 50 years. Hormonal and non-hormonal methods have been researched since the 70s, but side effects were too severe for implementation.

An immobilized ejaculated spermatozoon is inserted into a human oocyte. (Image: Eugene Ermolovich/Wikimedia Commons)
An immobilized ejaculated spermatozoon is inserted into a human oocyte. (Image: Eugene Ermolovich/Wikimedia Commons)

New, safe, effective and acceptable contraceptive methods for men would help to address the needs of couples who do not, or cannot, use currently available methods. Having a wider choice of contraceptives is also known to increase uptake of all methods. Perhaps more significant is the potential to give men increased options in family planning, leveling the gender inequality in this area.

Silent swimmers

There is a real demand – and an unmet need – for the development of new treatments for both male infertility and family planning. But, before we can tackle these global health issues, we need to understand how sperm work. Without this detailed knowledge, and a potential target for a drug to work on, it is virtually impossible to develop new compounds to enhance, or inhibit, sperm function.

Sperm swimming (motility) is probably its most important characteristic. Although the underlying cellular mechanisms are not fully understood, changes in levels of calcium inside the sperm cell are known to be crucial to sperm function, including swimming and fertilisation. Fluctuations in the level of calcium within sperm cells is known to be due to specific membrane pores (ion channels) in the sperm tail – these pores are called CatSper.

A swimming sperm. From video by Kantsler et al. (CC BY 3.0)
A swimming sperm. From video by Kantsler et al. (CC BY 3.0)

High-throughput screening or HTS is an approach used by the pharmacology industry to discover new drugs, where automated experiments can examine thousands of compounds to “screen” for a desired effect. Compounds that show the desired effect are called “hits”.

We recently published a paper describing a HTS approach to look for new drugs to treat male infertility. Calcium inside sperm was fluorescently labelled, and levels then measured in response to a number of new drug compounds.

We screened more than 3,400 compounds and identified 48 hits, that showed the effects we needed. Further testing of several of these hit compounds found two that showed improved function and swimming in sperm, probably due to an effect on CatSper channels.

A potential cure

Although the original experiments used sperm from healthy volunteers, the researchers also saw enhanced function and swimming when they tested both compounds on samples from patients undergoing IVF. Given the lack of progress in treating male infertility to date, this is a promising find, even if it is very early days.

The beauty of this finding is that the compounds that we found would only act on sperm cells, because the ion channel “CatSper” is unique to sperm. This could help to avoid unwanted side effects, which makes these compounds attractive clinically and commercially. While this research has been directed at drug discovery for male fertility, it is possible to turn the concept around and find compounds that inhibit sperm swimming, thereby creating a new male contraceptive.

This is an advance that potentially offers hope to millions of couples worldwide, but there is still much that we need to know and understand to unlock the workings of the human sperm.

Sarah Martins da Silva, Consultant Gynaecologist and Senior Lecturer In Reproductive Medicine, University of Dundee.

This article first appeared on The Conversation.

We welcome your comments at letters@scroll.in.
Sponsored Content BY 

What’s the difference between ‘a’ washing machine and a ‘great’ washing machine?

The right machine can save water, power consumption, time, energy and your clothes from damage.

In 2010, Hans Rosling, a Swedish statistician, convinced a room full of people that the washing machine was the greatest invention of the industrial revolution. In the TED talk delivered by him, he illuminates how the washing machine freed women from doing hours of labour intensive laundry, giving them the time to read books and eventually join the labour force. Rosling’s argument rings true even today as it is difficult to deny the significance of the washing machine in our everyday lives.

For many households, buying a washing machine is a sizable investment. Oddly, buyers underestimate the importance of the decision-making process while buying one and don’t research the purchase as much as they would for a television or refrigerator. Most buyers limit their buying criteria to type, size and price of the washing machine.

Visible technological advancements can be seen all around us, making it fair to expect a lot more from household appliances, especially washing machines. Here are a few features to expect and look out for before investing in a washing machine:

Cover your basics

Do you wash your towels every day? How frequently do you do your laundry? Are you okay with a bit of manual intervention during the wash cycle? These questions will help filter the basic type of washing machine you need. The semi-automatics require manual intervention to move clothes from the washing tub to the drying tub and are priced lower than a fully-automatic. A fully-automatic comes in two types: front load and top load. Front loading machines use less water by rotating the inner drum and using gravity to move the clothes through water.

Size matters

The size or the capacity of the machine is directly proportional to the consumption of electricity. The right machine capacity depends on the daily requirement of the household. For instance, for couples or individuals, a 6kg capacity would be adequate whereas a family of four might need an 8 kg or bigger capacity for their laundry needs. This is an important factor to consider since the wrong decision can consume an unnecessary amount of electricity.

Machine intelligence that helps save time

In situations when time works against you and your laundry, features of a well-designed washing machine can come to rescue. There are programmes for urgent laundry needs that provide clean laundry in a super quick 15 to 30 minutes’ cycle; a time delay feature that can assist you to start the laundry at a desired time etc. Many of these features dispel the notion that longer wash cycles mean cleaner clothes. In fact, some washing machines come with pre-activated wash cycles that offer shortest wash cycles across all programmes without compromising on cleanliness.

The green quotient

Despite the conveniences washing machines offer, many of them also consume a substantial amount of electricity and water. By paying close attention to performance features, it’s possible to find washing machines that use less water and energy. For example, there are machines which can adjust the levels of water used based on the size of the load. The reduced water usage, in turn, helps reduce the usage of electricity. Further, machines that promise a silent, no-vibration wash don’t just reduce noise – they are also more efficient as they are designed to work with less friction, thus reducing the energy consumed.

Customisable washing modes

Crushed dresses, out-of-shape shirts and shrunken sweaters are stuff of laundry nightmares. Most of us would rather take out the time to hand wash our expensive items of clothing rather than trusting the washing machine. To get the dirt out of clothes, washing machines use speed to first agitate the clothes and spin the water out of them, a process that takes a toll on the fabric. Fortunately, advanced machines come equipped with washing modes that control speed and water temperature depending on the fabric. While jeans and towels can endure a high-speed tumble and spin action, delicate fabrics like silk need a gentler wash at low speeds. Some machines also have a monsoon mode. This is an India specific mode that gives clothes a hot rinse and spin to reduce drying time during monsoons. A super clean mode will use hot water to clean the clothes deeply.

Washing machines have come a long way, from a wooden drum powered by motor to high-tech machines that come equipped with automatic washing modes. Bosch washing machines include all the above-mentioned features and provide damage free laundry in an energy efficient way. With 32 different washing modes, Bosch washing machines can create custom wash cycles for different types of laundry, be it lightly soiled linens, or stained woollens. The ActiveWater feature in Bosch washing machines senses the laundry load and optimises the usage of water and electricity. Its EcoSilentDrive motor draws energy from a permanent magnet, thereby saving energy and giving a silent wash. The fear of expensive clothes being wringed to shapelessness in a washing machine is a common one. The video below explains how Bosch’s unique VarioDrumTM technology achieves damage free laundry.

Play

To start your search for the perfect washing machine, see here.

This article was produced by the Scroll marketing team on behalf of Bosch and not by the Scroll editorial team.