Tag Archive for: biology

Exploring Sex Differences In Body Size Using The Fruit Fly (Drosophila melanogaster)

Interviewee: Celena Cherian, PhD Candidate, Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia | Authors/Editors: Romina Garcia de leon, Janielle Richards (Blog Co-coordinators)

Published: December 6, 2024

Can you tell us about your research?

In the animal kingdom, there are sex differences in body size across many species. This is true for Drosophila (fruit flies) as well, where females are larger than males. Furthermore, sex differences within species exist in multiple aspects of physiology and metabolism. Therefore, my research project involves exploring sex differences in body size using the fruit fly with the aim of elucidating the mechanism for these differences. I am particularly interested in the larval adipose tissue biology as it is important for systemic growth.

What led you to undertaking this research?

I was searching for labs that used imaging techniques to study cell biology, and mitochondrial biology in particular. This was the only lab that I came across which employed these techniques while exploring sex differences. I was then struck by the fact that nobody was studying sex differences in this area. This was the primary reason I wanted to do research in the area; the research was novel and I wanted to be involved in generating data on physiology and metabolism within females. Additionally, I really loved the way my supervisor wrote her papers. They were very easy to understand and I could see how passionate she was about science communication. I was sold before I got into the lab and luckily I was able to secure a position.

Are there any findings in the field and/or your study you wish to highlight?

Prior literature shows that ribosome and mitochondrial biology in the larval adipose tissue are both important for cellular growth, organism growth, and body size. However, these papers didn’t use both sexes separately and instead mixed sex populations were used. Many studies also classically only use males to study for metabolism, because female hormones were presumed to be confounding factors which has created a gap in the contribution of mitochondrial and ribosome function in cell growth. 

This was the starting point for our research and so far we found that female larval adipose tissue has significantly higher levels of mitochondrial and ribosomal protein genes than males. We are currently working to investigate the cellular significance of this exciting finding.

Where do you see your research going?

I hope my research encourages others to analyze males and females separately in the field of metabolism and physiology as data in this area is limited. I hope to understand the role of protein synthesis and mitochondrial function in regulating sex differences in growth. I would like to find which pathways are involved and also look at the effect of nutrients on these sex differences. Eventually, I am interested in looking at the impact of sex determination genes / sex chromosomes on these cellular functions.

Behind the Science: Pregnancy and Multiple Sclerosis – What’s The Link?

Interviewees: Pia Campagna, Postdoctoral Fellow, Monash University, Melbourne, Australia Authors/Editors: Romina Garcia de leon, Shayda Swann (Blog Co-coordinators)

Published: December 15th, 2023

When there are clear sex differences in disease prevalence, researchers must question the underlying factors. Women with Multiple Sclerosis (MS) outnumber men 4 to 1. What is being done to understand this statistic? How can we look into female-specific factors to disentangle these questions? 

For this month’s Behind the Science, we interviewed Pia Campagna who provided some insight into these questions.  

 

Can you tell us about your research? 

Our lab studies Multiple Sclerosis (MS) and other neuro-immunological conditions. Much of my work focuses on incorporating women’s health into MS research by looking at pregnancy and menopause. MS affects 2 million people globally, roughly 75% of which are women. Previous work from our group has shown the clinical effect of pregnancy, where a pregnancy before disease onset delays the onset of MS symptoms by 3.4 years. After onset, the effect of pregnancy is more controversial, but work from our group has shown a protective effect of pregnancy on long-term disability accumulation.In my postdoc, I’m seeking to understand the biological mechanisms underpinning these clinical effects via a national multi-site prospective study.

 

Why did you want to get involved in women’s health? 

I started research in MS due to the demographic of those affected – women. Because of this, it’s an interesting population to study in light of all of the female-specific experiences that interact with this disease. For example, it’s a disease that’s primarily diagnosed in a woman’s reproductive years (20-40 years old) so there are interactions with pregnancy, and due to the chronic nature, women are living with MS during perimenopause and menopause too.

I started my Ph.D., focused on genomics, prognostic modelling and machine learning in MS. It just so happened that other people in our group were doing this fascinating work on pregnancy. I had the opportunity to delve into the epigenetic impacts of pregnancy in women with MS, which sparked my interest in women’s health route MS. I did love the bioinformatic aspects of my Ph.D. work and hope to incorporate that down the line when we have the data available. 

 

Is there anything interesting that you’ve learned from your research findings?

When we compared the whole blood DNA methylation profiles of women with MS who had not given birth, we identified differences in methylation patterns at genes enriched in neurogenesis and axon guidance pathways. After noticing these signals, we hypothesized that the hormonal changes from pregnancy created long-term effects that drive changes to the clinical course of MS.  Now, we are collecting blood from women with and without MS before, during and after pregnancy, so eventually we’ll be able to look at DNA methylation in these different stages, as well as a range of other -omic profiles. 

What impact do you hope to see with this work in the long term?

Not only is the prevalence of MS increasing worldwide but so is the female-to-male ratio. I hope that research focuses more on the female-specific aspects of the disease, which is still very understudied. Although there’s strong evidence that pregnancy is beneficial before onset, and some evidence of a beneficial long-term effect, , it’s surprising to me that we still don’t know how or why. Detangling this will not only be beneficial to women but also more individualized therapeutic targets benefit men as well. Another frontier in MS research that I would like to see more of is the impact of menopause. For example, we still don’t know if the disease gets worse after menopause, how estrogen loss interacts with disease-modifying therapies, or whether they’re as effective. Understanding the clinical aspects of menopause and subsequently, the biological aspects of menopause is an important route to take moving forward.

Where can people learn more about your work?

Same Disease, Different Risks & Symptoms: Cardiovascular Disease in Women

Authors: Nabilah Gulamhusein: Libin Cardiovascular Institute & Cumming School of Medicine, University of Calgary; Elaha Niazi: Libin Cardiovascular Institute & Cumming School of Medicine, University of Calgary; Smriti Juriasingani: Cumming School of Medicine, University of Calgary 

Editors: Romina Garcia de leon & Shayda Swann (Blog Co-coordinators).

 

Cardiovascular disease is the leading cause of death among women worldwide, and in fact, women are more likely to die from a heart attack than men. This often surprises women and their care providers because cardiovascular disease has traditionally been considered a male-dominated disease. Deaths due to cardiovascular disease have declined in the last 50 years in men, but have risen in women, especially in younger women. It is increasingly apparent that there are both sex-based (related to biological attributes) and gender-based (related to socially constructed identities, expression, roles, and behaviors) differences in cardiovascular risk factors, as well as the development and progression of cardiovascular diseases. Though we have made great gains in improving men’s heart health, women remain under-researched, under-diagnosed, under-treated, and under-supported; consequently, many women are unaware of their cardiovascular disease risk. 

 

Though many consider cardiovascular disease only a disease of older women, it affects women at all life stages. Reproductive-aged women have been developing increasingly disadvantageous cardiovascular disease risk profiles, including obesity, physical inactivity, an unhealthy diet, and stress; these factors appear to have a larger impact on women than men. While these are certainly important considerations in cardiovascular disease risk for young women, it is time to adopt a broader understanding of female-specific risk factors.

 

In addition to traditional risk factors, female-specific and female-predominant factors contribute to cardiovascular risk. Conditions related to fertility, such as polycystic ovarian syndrome and menstrual irregularities, have been associated with an increased cardiovascular disease risk. In addition, certain pregnancy complications can increase heart disease risk, including gestational hypertension and diabetes. It is critical that women have the opportunity for informed discussions with healthcare providers to mitigate reproductive and pregnancy-related risks. There is also a multitude of medical conditions disproportionately impacting women that result in increased cardiovascular risk. These include depression, diabetes, hypertension, autoimmune diseases, and chronic kidney disease. Awareness of these important female-specific and female-predominant risk factors can empower women in making heart-healthy choices. 

 

There is no question, however, that as a woman ages, cardiovascular risk increases considerably due to changes in the heart and blood vessels. The timing of the onset of menopause, as well as perimenopause (when the transition to menopause begins, but before a final menstrual period), may influence a woman’s cardiovascular risk. Premature menopause (before age 40) and early menopause (before age 45) are significantly associated with increased cardiovascular risk. Additionally, cardiovascular disease risk commonly increases after menopause, which is attributed to changes in hormone levels (e.g., estrogens).

 

Early heart attack symptoms are missed in more than 50% of women and therefore, it is important to recognize that women may have different symptoms compared to men during a heart attack. While women experience symptoms such as sharp chest pain, they may also have aching sensations across the back and stomach, pain in the jaw, neck or arm, shortness of breath, abnormally excessive sweating, nausea, indigestion, and extreme fatigue. Unlike men, women are more likely to present with three or more symptoms in addition to chest pain when having a heart attack. Being informed and spreading the word about heart disease symptoms in women is the first step towards protecting the women in our lives. 

 

Knowing that women have unique cardiovascular risk factors and subtle symptoms can be overwhelming, however, heart disease is largely preventable. First, following Canada’s 24-hour movement guidelines, including getting 150 minutes of moderate to vigorous physical activity per week, reducing sedentary time, and getting enough good quality sleep is recommended for a healthy lifestyle. Research shows that consuming 7-10 servings of fruits and vegetables every day, while limiting processed foods, sugar and salt are key ways to reduce cardiovascular risk. It is also important for women to have regular check-ups with their healthcare providers and take their medications as prescribed. Finally, living free from commercial tobacco and vaping while reducing alcohol intake and actively managing stress can also be beneficial.  

 

To learn about women’s cardiovascular health, including risk factors, symptoms, treatment, and support, you can participate in Wear Red Canada or visit WearRedCanada.ca! Wear Red Canada is run by volunteers across the country, including healthcare providers, scientists, and people with lived experience. Wear Red Canada Day is celebrated annually on February 13th to raise awareness about women’s heart and vascular health. Each year, you are invited to attend presentations by leading experts, join the Wear Red Canada Movement Challenge, and visit local landmarks that will light up RED in support of women’s heart health. On February 13, wear RED and join us on social media to share selfies or pictures of your participation in these events with the hashtag #HerHeartMatters and tag @WearRedCanada to share this important message. By starting conversations about women’s cardiovascular health and getting informed, we can increase awareness and improve the health of the women in our lives.

 

 

 

 

The Gut-Brain Connection: Why Biological Sex May Matter

Author: Avril Metcalfe-Roach, PhD student, University of British Columbia | Editors: Negin Nia and Arrthy Thayaparan (Blog Coordinators) 

Published: November 12th, 2021

If you had to build your own house from scratch, what supplies would you bring to the job? High-quality building materials would certainly make the house much more durable, and having a diverse array of tools on hand will make construction much easier. 

Joe, on the other hand, brought just four zip ties and a wrench and is probably in for a tough time. If you live in a hot climate, you might consider installing air conditioning; in cold climates, good insulation and a heater will help you avoid freezing during the winter. In any case, putting love and effort into the home helps ensure that it keeps you comfortable for many years.

Similarly, the food we eat directly impacts every facet of our health. The links between diet, obesity, and cardiovascular disease are well known. However, more research indicates that dietary habits also directly impact issues like cancer, mental health, and even neurodegenerative diseases, including Alzheimer’s and Parkinson’s disease. Healthy eating can also indirectly reduce disease burden by ensuring that your body has the tools it needs to heal and combat infection.

So, how do different foods actually exert these effects? 

Each food, of course, has a different nutritional profile and will provide your body with different tools. We can anticipate what tools we will need and provide them before problems arise. For example, people who menstruate require more iron in their diets, and oral contraceptive use can lower the absorption of multiple vitamins and minerals. 

Humans also have a little problem: we’re more complex than our genetics allow. While our bodies directly absorb and create many nutrients, a lot of essential nutrients are created solely by the 100 trillion bacteria living in our intestines. In exchange for some energy and a warm place to call home, these beneficial bacteria help to prevent other harmful bacteria from infecting the gut. This keeps our gut tissue working properly, and produces vitamins and other compounds that can leave the gut and promote health throughout the body. For example, certain types of fiber are broken down by bacteria into molecules that enter the bloodstream and help to reduce inflammation.

Even the ‘happy’ chemical, serotonin, is mostly produced in the gut. Like us, each type of bacteria has its own nutritional requirements that mostly revolve around fiber-rich foods such as fruits and whole grains. By eating a variety of nutrient-dense foods, we foster a gut environment full of healthy, anti-inflammatory bacteria that in turn keep us healthy. 

What type of diets are sustainable and have health benefits?

Dietary research is progressing at a staggering rate, and it can be overwhelming to stay up to date. When the research is clarified, however, certain dietary patterns emerge that are consistently linked with specific health outcomes. 

The Mediterranean diet, which promotes plant-based foods, fish, and healthy oils, while limiting red meat and other animal products, is perhaps the best-studied healthy diet in the world. It has been associated with lower rates of cardiovascular disease, obesity, glucose sensitivity and diabetes, and overall mortality.

More recently, a few studies have suggested that the Mediterranean diet may improve brain health. Neurodegenerative diseases are not yet well understood, and there are very few known factors that help to prevent them. Recognizing this, Dr. Martha Clare Morris unveiled the MIND diet in 2015, which optimizes the Mediterranean diet against cognitive decline.

What is the MIND diet and how does it benefit us?

Most food groups are conserved between the two diets; crucially, however, the MIND diet also promotes brain-healthy berries and leafy greens, while restricting pro-inflammatory sugary, fried, and processed food. These latter foods are becoming increasingly common, especially in North America; some research suggests that their overconsumption can even negate some of the health benefits normally associated with the Mediterranean diet. 

As a result, the MIND diet has since been associated with significantly reduced rates of many neurodegenerative diseases, including Alzheimer’s, cognitive decline, and general motor decline; what’s more, the strength of these associations seems to exceed those of the Mediterranean diet.

We recently investigated the MIND diet in a group of individuals with Parkinson’s disease, where we assessed their normal dietary intake and assigned a score based on how closely their intake resembled the MIND diet. Female participants had higher scores on average, indicating closer MIND diet resemblance. Participants with high scores developed Parkinson’s disease significantly later than those with low scores; unexpectedly, this association was especially strong in the female participants, where dietary habits accounted for up to 17 years’ difference in disease onset. Interestingly, the MIND diet accounted for only 10 years in men, and the Mediterranean diet accounted for 10 years with no apparent sex differences.

How do these diets work exactly?

While the complexity of these diets means that it is difficult to know exactly how they work, a sizable amount of research has zeroed in on our microscopic friends as a key factor. Brain-healthy diets help anti-inflammatory bacteria to thrive, which may help to limit inflammation in the brain. Regulation of the immune system is known to be partially sex-specific – for example, women are more prone to autoimmune disease, where the immune system attacks healthy body tissue – and these differences might impact how effective the diets are against neurodegeneration. Indeed, women make up only 1/3 of all Parkinson’s disease cases. 

While our findings here are only correlational, they highlight the importance of including sex as a factor in further research. With a strong enough framework, everyone can design a house that will keep them happy and healthy for a lifetime.