To better understand the origin of inflammatory bowel diseases such as Crohn’s, researchers set out to create a “human cell atlas” or Human Cell Atlas (HCA), in which they map the cells of the human intestine from early development through adulthood.
- Researchers have listed all of the cell types in the human body in a cell atlas called the “Human Cell Atlas”.
- This tool provides valuable information on the origin of inflammatory bowel diseases (IBD) such as Crohn’s disease.
Affecting nearly 200,000 people in France, inflammatory bowel disease, or IBD, is due to an inadequate immune response against the normal bacteria that make up the gut microbiota. They are characterized by major lesions, even fistulas, in the colon and rectum (ulcerative colitis or ulcerative colitis) or the entire digestive tract (Crohn’s disease), causing abdominal pain, severe fatigue and bleeding.
Although the origin of IBD is still largely unknown, research is increasing to better understand these chronic diseases and provide treatments for them. Among these, the initiative of researchers raises many hopes. Gathered within the Human Cell Atlas (HCA) consortium, they have set themselves the task of mapping each type of cell in the human body in order to better understand the origin of IBD. Two studies published on September 8 in the journal Nature reveal how this cellular atlas of the intestine – the most comprehensive to date – advances the understanding of these diseases.
Cells involved in Crohn’s disease identified
The intestine is a complex tissue made up of several types of cells, which changes enormously during early development. To understand how the gut grows and functions, researchers from the Wellcome Sanger Institute, the University of Newcastle, the University of Cambridge and their collaborators in the Human Cell Atlas studied more than a third of a million individual intestinal cells from developing tissues and from child and adult donors.
Using state-of-the-art single-cell genomics and spatial analysis techniques, the team revealed which genes were active in each cell and created a comprehensive gut cell atlas across time and across 12 regions of the gut.
Thanks to this cellular atlas (the data of which is open access), the researchers discovered how the immune and nervous systems develop in the healthy intestine, and identified important differences along the intestines.
They were also interested in cell development in cases of IBD. The first study thus focused on the intestinal biopsy tissue of children with Crohn’s disease. These data, together with data on healthy development, provide new insight into rare and common bowel diseases.
“This intestinal cell atlas is already very useful, says Dr. Kylie James, lead author of the article. It is already shedding new light on the origins of Crohn’s disease and other intestinal diseases. For example, we have identified three key cells that attract immune cells to form lymphoid tissue during development, and we have shown that this same developmental pathway may cause Crohn’s disease. This knowledge is helping researchers identify potential new drug targets for bowel disease.”
Future genomic reference maps of cells
In the second article published in Naturethe researchers reveal the detailed roadmap of how HCA Development Biological Network researchers plan to create these reference genomic maps of cells, tissues and organs at different stages of healthy human development.
According to Professor Muzlifah Haniffa, coordinator of the Developmental Biological Network, “the cellular atlas of human development will be an essential resource for understanding many aspects of biology and disease, in order to improve human health”. “Our roadmap shows the progress made so far, including the creation of a gut development atlas, how we plan to overcome challenges to achieve a comprehensive human development atlas, and how this will be used to understand diseases”he concludes.
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