Summary: Immune responses during pregnancy can alter gene regulation in the developing brain of mouse embryos. Researchers have discovered that maternal immune responses are detected by microglia, brain cells that then affect surrounding neurons.
These changes persist in juvenile mice, suggesting long-term effects on brain development. This research could help understand the origins of neurodevelopmental disorders like autism and schizophrenia.
Highlights:
- The role of microglia: Maternal immune responses are detected by microglia in the embryonic brain, influencing gene regulation.
- Persistent changes: Changes in genetic regulation in the brain persist into juvenile stages, long after the immune response has subsided.
- Neurodevelopmental impact: The findings provide insight into how maternal infections might contribute to neurodevelopmental disorders.
Source: Company of Biologists
No parent wants to risk their child having a serious infection, especially while they are still in the womb, but did you know that the immune system answer Could viral infection during pregnancy also affect the development of unborn offspring?
Scientists from Harvard University in Cambridge, USA, have shown that immune responses in pregnant mice are detected by a specific type of brain cell in the developing embryo and change the way genes are regulated in the brain – a change that persists in juvenile mice.
Published today in the magazine DevelopmentThis study provides new insights into how the maternal immune response might influence embryonic brain development and could help researchers understand the origins of neurodevelopmental disorders such as autism.
Scientists have long suspected that fetal exposure to infectious microbes may increase the risk of developing neurological diseases such as schizophrenia and autism spectrum disorders.
There is also evidence that fighting infection during pregnancy could affect the growth of offspring in the womb, even if the embryos themselves are not infected.
However, it is not clear how embryos recognize their parents’ immune response and the exact consequences for their development.
In their latest study, a Harvard University group led by Professor Paola Arlotta identified a specific cell type in the embryonic mouse brain that responds to an immune response in the mother.
Researchers used a compound that mimics a virus to stimulate an immune response in pregnant mice without causing an actual infection. They then characterized how the embryonic brain cells responded by assessing which genes were turned on or off.
Using this approach, scientists have shown that cells called “microglia” can detect the maternal immune response.
“Microglia are the immune cells of the brain. They play an essential role during inflammation and infection and also have fundamental functions in healthy brain development,” explained Arlotta.
Following the mother’s immune response, embryonic microglia change which genes are turned on or off, which also occurs in surrounding brain cells, such as neurons.
Interestingly, the change in gene regulation in neighboring cells depends on the presence of microglia in the brain; When the researchers repeated the experiments on mice lacking microglia, other brain cells did not respond to the maternal immune response.
Although most viral infections are often short-lived, scientists have found that changes caused by the maternal immune system in embryonic brain cells persist long after the immune response has subsided.
“Based on previous studies demonstrating that microglia exposed to early infections respond differently to stimuli in adulthood, we hypothesized that the maternal immune response might induce changes in microglial gene regulation that persist after birth,” said Dr. Bridget Ostrem, co-author of the study. .
This research improves our understanding of the cellular basis of neurodevelopmental disorders in humans.
“Our results suggest a potential role for microglia as therapeutic targets in maternal infections,” Ostrem said, although more work remains to be done.
Harvard researcher Dr. Nuria Domínguez-Iturza added: “Next, it will be crucial to determine the long-term behavioral implications of the changes we observed in this study. »
About this news on research into maternal immunity and fetal development
Author: Alex Eve
Source: Company of Biologists
Contact: Alex Eve – Company of Biologists
Picture: Image is credited to Neuroscience News
Original research: Free access.
“The fetal brain response to maternal inflammation requires microglia” by Anne Manning et al. Development
Abstract
Fetal brain response to maternal inflammation requires microglia
In utero Maternal infection and inflammation can harm fetal brain development. Maternal systemic diseases, even in the absence of direct fetal brain infection, are associated with an increased risk of neuropsychiatric disorders in affected children.
The cell types that mediate the fetal brain response to maternal inflammation are largely unknown, preventing the development of new therapeutic strategies.
Here we show that microglia, the resident phagocytes of the brain, highly express relevant pathogen and cytokine receptors throughout embryonic development.
Using a rodent model of maternal immune activation (MIA) in which polyinosinic:polycytidylic acid is injected into pregnant mice, we demonstrate long-lasting transcriptional changes in fetal microglia that persist into postnatal life.
We find that MIA induces widespread changes in gene expression in neuronal and non-neuronal cells; Importantly, these responses are abolished by selective genetic deletion of microglia, indicating that microglia are necessary for the transcriptional response of other cortical cell types to MIA.
These results demonstrate that microglia play a crucial long-lasting role in the fetal response to maternal inflammation and should be explored as potential therapeutic cellular targets.
News Source : neurosciencenews.com
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