JUN 01, 2018 7:39 AM PDT

How does estrogen increase the risk of autoimmunity for women?

WRITTEN BY: Kara Marker

The unique activity of estrogen hormones and their cell receptors in the female body may explain why women are more likely than men to develop autoimmune diseases. From the University of Turku, scientists investigate an estrogen pathway as a new way to target autoimmunity.

Histopathology image of chronic inactive ulcerative colitis. Credit: CoRus13

In general, women are more likely than men to develop autoimmune diseases, like rheumatoid arthritis, multiple sclerosis, and lupus – making estrogen a likely causative factor in autoimmunity. In the female body, estrogen is the key hormone for growth and development of female sexual characteristics and reproduction.

The name “estrogen” includes several related hormones, such as estrone, estradiol, and estriol. Estrogen is produced in the ovaries, adrenal glands, and fat tissues, circulating in the blood and binding to cells via hormone receptors on the cell surface. After binding, estrogen activity has a variety of effects on breast and uterus tissue as well as brain, bone, liver, and heart tissue. For example, estrogen is responsible for regulating the growth of the uterine lining in the first stage of the menstrual cycle.

However, estrogen is not completely unique to females. In males, estrogen plays a role in modulating libido, erectile function, and spermatogenesis.

Estrogen binds cells through the estrogen receptor alpha protein. This is one estrogen receptor subtype with activity in the nucleus. Mainly, this receptor helps transcribe certain target genes, giving it the ability to regulate key physiological functions in the mammary glands, uterus, ovaries, bones, liver, and adipose tissue. This receptor’s “cousin,” estrogen receptor beta protein, is found in bladder, ovary, colon, and adipose tissue.

So what happens when T cells’ estrogen receptors are missing? With their new study, scientists wanted to answer this question. Thus, they genetically altered mice to lack estrogen receptor alpha protein on T cells. When they transferred these lacking T cells to mouse models of human inflammatory bowel disease, the mice did not develop inflammation in the colon, compared to mouse models without the transferred cells who did develop disease.

RNA sequencing studies also helped them find that the estrogen receptor alpha protein “regulates multiple aspects of T cell function, including T cell activation, proliferation, and survival,” explained research leader Docent Zhi Chen.

With this finding, it is likely that the receptor protein is causing dysfunction in regulatory T cell activity. These “Tregs” are vital for maintaining the balance in the immune system. Too little immune activity leads to pathogenic invasions running rampant in the body, and too much immune activity results in allergies and autoimmune diseases. It could be that estrogen receptors are disrupting that balance, explaining in part why women are more vulnerable to autoimmune diseases than men.

The present study was published in the journal Science Signaling.

Sources: HealthyWomen.org, Steroids, Asian Journal of Andrology, University of Turku

 

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
FEB 02, 2021
Immunology
Pumping the Brakes on Stomach Cancer Progression
FEB 02, 2021
Pumping the Brakes on Stomach Cancer Progression
By the time stomach cancer is diagnosed, it’s often bad news for patients. The disease often presents with relativ ...
MAR 18, 2021
Immunology
COVID Cytokine Storm Chasers Look Inside the Lungs
MAR 18, 2021
COVID Cytokine Storm Chasers Look Inside the Lungs
Immunologists have revealed one of the underlying mechanisms behind COVID’s life-threatening cytokine storms. By s ...
MAR 23, 2021
Immunology
Assay Detects Antibodies in Asymptomatic COVID Carriers
MAR 23, 2021
Assay Detects Antibodies in Asymptomatic COVID Carriers
It is estimated that around one in five people infected with SARS-CoV-2 will not show any infection symptoms. Some of th ...
APR 11, 2021
Genetics & Genomics
Trial Shows Personalized Cancer Vaccines are Safe
APR 11, 2021
Trial Shows Personalized Cancer Vaccines are Safe
Vaccines are mostly known as tools to prevent illness. But cancer vaccines are a bit different, and aim to treat existin ...
APR 29, 2021
Immunology
A Week for World Immunization
APR 29, 2021
A Week for World Immunization
The World Health Organization (WHO) is calling our attention to World Immunization Week, which comes in the last week of ...
MAY 11, 2021
Genetics & Genomics
Gene Therapy Trial for Severe Immune Disorder is Successful
MAY 11, 2021
Gene Therapy Trial for Severe Immune Disorder is Successful
Severe combined immunodeficiency (SCID), which virtually eliminates a patient's immune system, and severely affects thei ...
Loading Comments...