pt | en Login Registo
pt | en Login Registo
EARA Newsletter

13 de Outubro de 2025

 
 

EARA News Digest 2025 - Week 42


Welcome to your Monday morning update, from EARA, on the latest news in biomedical science, policy and openness on animal research. 

This week: Mice studies were key for 2025 Nobel Prize research; Alzheimer’s protein fights cancer in mice; Pregnancy turns on aggression on female mice brains.

Mice studies were key for 2025 Nobel Prize research

The 2025 Nobel Prize in Physiology or Medicine was awarded to three researchers — Shimon Sakaguchi, Mary E. Brunkow and Fred Ramsdell — for discovering how the immune system is kept in check, based on studies in mice. 

Until 1995, it was believed that the immune system avoids attacking the body by eliminating cells that recognise the body’s own proteins, a process that occurs early in life in the thymus. However, the laureates identified regulatory T cells — immune cells that send signals to calm the immune system when attacking our own cells, thus preventing harm to the body. 

Sakaguchi, at Osaka University, performed a key experiment by removing the thymus of newborn mice, which caused them to develop autoimmune diseases. However, when he injected the mice with mature T cells from other mice, they were protected, suggesting that there was another security guard keeping the immune system in check. By performing similar experiments with different types of T cells, he discovered regulatory T cells, the ones responsible for protecting against autoimmunity. 

Mary Brunkow and Fred Ramsdell, researchers in the US, were working on the effects of radiation when they found a mutation that made T cells attack the body’s own organs in mice. They discovered the gene responsible, Foxp3, and found that mutations in this gene cause IPEX, a rare autoimmune disease in humans.  

Two years later, Sakaguchi and other researchers put these discoveries together and showed that the Foxp3 gene controls the development of regulatory T cells.   

“Their discoveries have been decisive for our understanding of how the immune system functions and why we do not all develop serious autoimmune diseases,” said Olle Kämpe, chair of the Nobel Committee and an autoimmunity researcher at EARA member Karolinska Institute. 

These fundamental findings are contributing to research on how to prevent organ rejection after transplantation and have paved the way for many treatments for cancer and autoimmune diseases which are now undergoing clinical trials. 

 

 

Alzheimer’s protein fights cancer in mice

Researchers in the US have found that amyloid beta, a hallmark in Alzheimer’s, can strengthen immune responses and reduce tumour growth in mice. 

In Alzheimer’s, amyloid beta builds up in the brain and blocks the recycling of damaged mitochondria — cell components responsible for energy — leading to neuronal death and memory loss.  

Previous studies showed that adults over 59 years with Alzheimer's were 21 times less likely to develop cancer than those without the disease, but the reason behind this relationship remained elusive.  

A team at the Medical University of South Carolina has now found that that the same protein that harms the brain in Alzheimer’s, amyloid beta, can have a beneficial effect on immune cells, specifically T-cells, which identify and destroy cancer.  

In genetically modified mice with Alzheimer’s-like symptoms, amyloid beta's effect on mitochondria enhanced T-cells energy production, making them stronger and more active against threats like cancer. These mice showed reduced tumour growth in skin and oral cancer models. Transferring mitochondria from these T-cells to older immune cells restored their activity and anti-tumour strength.  

“Older T-cells began functioning like young, active T-cells again,” said Besim Ogretmen, lead researcher of the study published in Cancer Research. “That was an incredible finding because it suggests a whole new way to think about rejuvenating the immune system.” 

The research points to potential therapies that could recharge the immune system. 

 

 

Pregnancy turns on aggression on female mice brains     

Researchers in Sweden have discovered what changes in the brain of mice that unlock the so-called maternal aggression. 

Female mice are normally not aggressive but become suddenly aggressive during pregnancy and after giving birth. Researchers at Stockholm University and EARA member Karolinska Institute have discovered that a group of neurons previously known to be responsible for aggressiveness in males is dormant in females but becomes active during this period.  

They observed that females that had recently given birth, when socialising with other mice, had behaviours such as chasing or biting, which did not happen with female mice that had never been pregnant. In the mothers, the researchers observed that the dormant brain region was activated.  

Using light to turn these neurons on and off — optogenetics — in females who were mothers, the team discovered that these neurons are responsible for maternal aggression. By adding the maternal hormones to postmortem brain tissue, the team also found that these hormones make it easier to turn on these neurons after they first become active.  

These findings suggests that mammals’ brains could be more flexible than previously thought, turning on and off behaviours according to the requirements of specific life periods. 

"This is a study on laboratory mice, and we do not currently know whether the results can be transferred to humans. But the mechanism that we identify here… may reflect a principle of brain flexibility with relevance beyond maternal aggression," said Christian Broberger, leader of the study published in Nature Communications. 






Registo na página SPCAL

O registo é rápido e permite-lhe acesso a conteúdos exclusivos e reservados para utilizadores cadastrados na página da Sociedade Portuguesa de Ciências em Animais de Laboratório.

Efetuar registo