Iron regulation

Question 1

What is hepcidin?

Answer 1

In short: Hepcidin lowers iron

The iron regulatory hormone secreted by the liver, it inhibits the action of ferroportin (iron uptake protein).

Resultant effect:
Prevent iron absorption and prevent iron uptake to bone marrow (prevent erythropoiesis).

Question 2

What is ferroportin?

Answer 2

The protein responsible for transporting iron across membranes: absorption across enterocytes in GI tract, and absorption, and stimulation of erythropoiesis in bone marrow.

Inhibited by hepcidin.

Question 3

Which influences decrease iron in the body by increasing hepcidin secretion?

Answer 3

High iron concentration - high transferrin saturation

Inflammation - Interleukin 6

MOA: Induce secretion of hepcidin, thereby decreasing iron levels.

Question 4

Which influences increase iron in the body by inhibiting hepcidin secretion?

Answer 4

Low transferrin saturation

Hypoxia

TMPR556 protein (Matriptase 2)

Growth differentiation factor 15 (upregulated in injury to organs)