Specialized Cells Clear Blood Toxins to Reduce Hemolysis Harm

What is it about?

When red blood cells break down (a process called hemolysis), they release harmful substances like hemoglobin and bilirubin into the bloodstream. These toxins can damage organs and tissues. In rare diseases like erythropoietic protoporphyria (EPP), red blood cells also release a toxic molecule called protoporphyrin IX (PPIX), which causes severe symptoms. Our research discovered a special type of cells—scavenger endothelial cells (SECs)—that act like “cleanup crews” in the body. In zebrafish and mice, these cells rapidly swallow harmful molecules released by broken red blood cells, including hemoglobin, bilirubin, and PPIX. This cleanup process depends on a protein called Stab2, which acts like a “garbage detector” on the cells’ surface. Importantly, when SECs remove these toxins, they protect tissues from damage. For example, in zebrafish with EPP-like symptoms, SECs reduced deaths caused by PPIX buildup. This shows that SECs play a vital role in preventing harm during both normal blood cell turnover and diseases involving red blood cell destruction.

Featured Image

Photo by ANIRUDH on Unsplash

Photo by ANIRUDH on Unsplash

Why is it important?

Our study reveals an unappreciated defense system alleviating hemolysis induced damage. This finding could lead to new therapies for diseases linked to hemolysis (e.g., sickle cell anemia, EPP) and highlight SECs as potential targets for treating toxin-related organ damage.

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