Question

Evolutionarily, hepcidin is upregulated to prevent pathogens from accessing iron. Pathogens use circulating iron to thrive. This response is also triggered by chronic disease states, thus causing anemia of chronic disease. What is the role of hepcidin in preventing pathogens from accessing iron?

1) It inhibits the release of iron from macrophages
2) It promotes the absorption of iron from the diet
3) It increases the production of iron in the liver
4) It enhances the utilization of iron by red blood cells

Answer 1

Hepcidin's role in preventing pathogens from accessing iron is to inhibit the release of iron from macrophages, thereby reducing iron availability in the bloodstream and contributing to the nutritional immunity of the host.

Step-by-step explanation:

The role of hepcidin in preventing pathogens from accessing iron is to inhibit the release of iron from macrophages. Hepcidin is a peptide hormone that regulates iron homeostasis in the body. When hepcidin levels are upregulated, it binds to the iron transporter ferroportin on the surface of cells, such as macrophages and enterocytes (intestinal iron-absorbing cells), triggering its internalization and degradation. This process prevents the release of iron stored in these cells into the bloodstream, reducing its availability for use by pathogens that require iron for growth and proliferation. At the same time, the decrease in iron release leads to a reduction in circulating iron levels, thereby contributing to the anemia seen in chronic disease states. By sequestering iron within cells, hepcidin plays a crucial role in the body's nutritional immunity, which denies pathogens the iron they need to survive and multiply.