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A super thin forgotten cell

By Johanna Andrae  
28 August, 2020     

Confocal microscope image of a blood vessel in the meninges outside the brain – cell nuclei (blue), perivascular fibroblasts (green), endothelial cells (white), extracellular matrix (red).

Microscope image of a blood vessel in the meninges outside the meninges showing different cell types


Our brains are highly vascularized to meet its high requirements of oxygen and energy. Oxygen rich blood enters the brain via large arteries, which gradually decrease in size to eventually form small capillaries. An adult human brain contains 650 km capillaries, from which oxygen leaves the blood to reach all cells in the brain. The capillary network is very dense and no cell in the brain is more than 20 µm away from a blood vessel. The blood vessels in the brain are surrounded by the blood-brain barrier (BBB), which protects our brains from pathogens and toxic agents. The special characteristics of the BBB are generated by different cell types like endothelial cells, astrocytes, microglia and pericytes forming tight junctions and basement membranes.

Knowledge about the BBB is important to understand disease progression and treatment of diseases in the central nervous system. For example, one drawback with the BBB is that it prohibits wanted drugs from entering the brain, which complicates systemic treatment of brain diseases. In this project, we study the role of perivascular fibroblasts, a so far poorly described cell type, which wrap around blood vessels in the brain. We have found that the cytoplasm of a perivascular fibroblast is extremely thin and that the cells are located between the vascular smooth muscle cells and the astrocytic endfeet.

Whether the perivascular fibroblasts contribute to the BBB or not, remains to be found out. Anyway, it is important to understand their potential roles during development, in the mature brain and during disease.

About the author:

Johanna is a researcher at the Rudbeck Laboratory and a docent in Developmental genetics. She is interested in developmental aspects of signaling via the platelet-derived growth factors (PDGFs), with a special focus on the PDGF receptor-alfa. Main research areas are the central nervous system and the lungs, with a high interest in the role of perivascular fibroblasts during vascular formation and during disease.

Photo of Joahnna AndraeJohanna Andrae
Uppsala University
Dept. Immunology, Genetics and Pathology
Rudbeck Laboratory C11
Dag Hammarskjölds Väg 20
751 85 Uppsala