Localisation of proteins of iron metabolism in the human placenta and liver

Abstract

FPN was also most strongly expressed by CD68 + Kupffer cells. These findings contribute to understanding how iron is transported and stored in the human placenta and liver.

Iron Homeostasis in Mother and Child during Placental Malaria Infection

“…Syncytiotrophoblasts express iron-regulatory proteins, including ferroportin, which is responsible for iron release into the fetal circulation. 13 In addition, animal studies revealed that hepcidin and iron levels in the fetal liver may also regulate maternal-fetal iron transport. [14][15][16] We aimed to study maternal and fetal hepcidin and other iron parameters to improve our understanding of human placental iron transport.…”

Ubiquitination of lysine-331 by Kaposi's sarcoma-associated herpesvirus protein K5 targets HFE for lysosomal degradation

“…More work will be required to resolve these alternatives. HFE protein has been detected in few tissues (31)(32)(33) and it will also be important to assess whether HFE ubiquitination represents a general mechanism controlling HFE expression and iron homeostasis in these sites.…”

The placenta: the forgotten essential organ of iron transport

“…Immunohistochemical studies have localized TFR1 and transferrin to the apical membrane of syncytiotrophoblasts. 25,26 Concordantly, immunoelectron microscopy demonstrated the presence of transferrin [26][27][28] and TFR1 29 on the membrane of cellular invaginations and intracellular vesicles, likely representing clathrin-coated endosomes that contain transferrin, 30,31 TFR1, 32 and TFR1-transferrin complexes. 30,32 Kinetic studies in BeWo cells 33 and placental microvillous membrane preparations 17,34,35 showed that diferric transferrin uptake is a specific and saturable process, with binding affinities similar to values reported in K562 erythroleukemia cells 36 and reticulocytes.…”

“…59 There is also evidence for a placental-specific ferritin heavy chain homolog with immunosuppressive activity. 60 Immunohistochemical studies of ferritin expression in syncytiotrophoblasts are conflicting, with the majority of reports showing a lack of expression, 25,[61][62][63] while others demonstrate some staining. 64,65 (Table 1) This discrepancy may be due to the use of antibodies that react differentially with each isoferritin.…”

“…46 In human syncytiotrophoblasts, DMT1 has variably been reported to have a punctate cytoplasmic distribution and to be localized predominantly to the apical 47,48 or basal membranes. 25,49 (Table 1) This dispersed pattern of DMT1 distribution may suggest multiple sites of action. The necessity of DMT1 in placental iron transport requires experimental confirmation, especially in light of the normal body iron concentration in neonatal Dmt1-null mice.…”