Seminarium Instytutowe

Dr Katarzyna Mleczko-Sanecka

International Institute of Molecular and Cell Biology

Tutuł: „Novel insights into functional alterations of iron-recycling macrophages.”


Iron deficiency is a global health burden with profound sociomedical impacts. Little is known about how functions of specialized cells are affected by low systemic iron levels, and how this contributes to the organism. Red pulp macrophages (RPMs) residing in the spleen are responsible for removing aged red blood cells from the bloodstream in the process called erythrophagocytosis. Following red blood cell lysis, RPMs release iron via the exporter ferroportin to replenish the pool of serum iron necessary for sustaining erythropoiesis. Iron efflux from RPMs is negatively controlled by the liverderived hormone hepcidin according to body iron needs. It was largely unknown if the rates of red blood cell uptake and digestion are regulated by iron availability, and specifically if these processes may be affected by low body iron status. We uncovered that RPMs possess specialized mechanisms that enhance their capacity for red blood cell clearance under irondeficient conditions, a phenomenon that likely contributes to the adaptation of the whole organism to limited iron supplies. We found that in a mildly anemic mouse model of nutritional iron deficiency, RPMs show enhanced erythrophagocytosis rate and increased potential for red blood cell degradation within lysosomes. Our data suggest that this energyconsuming ‘adaptive program’ is associated with a switch towards mitochondriabased metabolism,which is unique in comparison to other cell types. Interestingly, these responses were largely absent in peritoneal or liver macrophages, implying their high specificity to RPMs. Our further data suggest that a serum factor associated with systemic iron deficiency modulates RPMs’ phagocytic capacity. We hypothesized that one of such signals could be provided by low levels of hepcidin. Confirming this hypothesis, we found that hepcidin mimetic reverts elevated erythrophagocytosisrate and increased mitochondrial activity of RPMs in irondeficient mice. Taken together, in my talk I will present data from this ongoing project that aims to characterize new physiological responses to iron deficiency.


Informacja dla uczestników

Seminaria odbywają się języku angielskim w trybie on-line przy użyciu platformy ZOOM. Prezentacja trwa do 40 minut, dyskusja do 20 minut
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Wszystkie Seminaria Instytutowe odbywają się z użyciem tego samego odnośnika do Seminarium.