Gastrointestinal function, divalent metal transporter-1 expressionand intestinal iron absorption

2000 ◽  
Vol 440 (3) ◽  
pp. 496-502 ◽  
Author(s):  
Phillip S. Oates ◽  
Deborah Trinder ◽  
Evan H. Morgan
2020 ◽  
Author(s):  
Nupur K Das ◽  
Amanda Sankar ◽  
Andrew J Schwartz ◽  
Sumeet Solanki ◽  
Xiaoya Ma ◽  
...  

AbstractIron is critical for many processes including oxygen transport and erythropoiesis. Transcriptomic analysis demonstrates that HIF-2α regulates over 90% of all transcripts induced following iron deficiency in the intestine. However, beyond divalent metal transporter 1 (DMT1), ferroportin 1 (Fpn1) and duodenal cytochrome b (Dcytb), no other genes/pathways have been critically assessed with respects to their importance in intestinal iron absorption. Ferritinophagy is associated with cargo specific autophagic breakdown of ferritin and subsequent release of iron. We show here that nuclear receptor co-activator 4 (NCOA4)-mediated intestinal ferritinophagy is integrated to systemic iron demand via HIF-2α. Duodenal NCOA4 expression is regulated by HIF-2α during high systemic iron demands. Moreover, overexpression of intestinal HIF-2α is sufficient to activate NCOA4 and promote lysosomal degradation of ferritin. Promoter analysis revealed NCOA4 as a direct HIF-2α target. To demonstrate the importance of intestinal HIF-2α/ferritinophagy axis in systemic iron homeostasis, whole body and intestine-specific NCOA4-null mouse lines were assessed. These analyses demonstrate an iron sequestration in the enterocytes, and significantly high tissue ferritin levels in the dietary iron deficiency and acute hemolytic anemia models. Together, our data suggests efficient ferritinophagy is critical for intestinal iron absorption and systemic iron homeostasis.


2007 ◽  
Vol 293 (3) ◽  
pp. G640-G644 ◽  
Author(s):  
Khristy Thompson ◽  
Ramon M. Molina ◽  
Thomas Donaghey ◽  
Joseph D. Brain ◽  
Marianne Wessling-Resnick

Divalent metal transporter-1 (DMT1) mediates dietary nonheme iron absorption. Belgrade ( b) rats have defective iron metabolism due to a mutation in the DMT1 gene. To examine the role of DMT1 in neonatal iron assimilation, b/b and b/+ pups were cross-fostered to F344 Fischer dams injected with59FeCl3twice weekly during lactation. Tissue distribution of the radioisotope in the pups was determined at weaning ( day 21). The b/b pups had blood59Fe levels significantly lower than b/+ controls but significantly higher59Fe tissue levels in heart, bone marrow, skeletal muscle, kidney, liver, spleen, stomach, and intestines. To study the pharmacokinetics of nonheme iron absorption at the time of weaning,59FeCl3was administered to 21-day-old b/b and b/+ rats by intragastric gavage. Blood59Fe levels measured 5 min to 4 h postgavage were significantly lower in b/b rats, consistent with impaired DMT1 function in intestinal iron absorption. Tissue59Fe levels were also lower in b/b rats postgavage. Combined, these data suggest that DMT1 function is not essential for iron assimilation from milk during early development in the rat.


PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0218123 ◽  
Author(s):  
Layimar Cegarra ◽  
Andrea Colins ◽  
Ziomara P. Gerdtzen ◽  
Marco T. Nuñez ◽  
J. Cristian Salgado

2021 ◽  
Vol 22 (15) ◽  
pp. 8013
Author(s):  
Taewook Kang ◽  
Honggang Huang ◽  
Thomas Mandrup-Poulsen ◽  
Martin R. Larsen

Pro-inflammatory cytokines promote cellular iron-import through enhanced divalent metal transporter-1 (DMT1) expression in pancreatic β-cells, consequently cell death. Inhibition of β-cell iron-import by DMT1 silencing protects against apoptosis in animal models of diabetes. However, how alterations of signaling networks contribute to the protective action of DMT1 knock-down is unknown. Here, we performed phosphoproteomics using our sequential enrichment strategy of mRNA, protein, and phosphopeptides, which enabled us to explore the concurrent molecular events in the same set of wildtype and DMT1-silenced β-cells during IL-1β exposure. Our findings reveal new phosphosites in the IL-1β-induced proteins that are clearly reverted by DMT1 silencing towards their steady-state levels. We validated the levels of five novel phosphosites of the potential protective proteins using parallel reaction monitoring. We also confirmed the inactivation of autophagic flux that may be relevant for cell survival induced by DMT1 silencing during IL-1β exposure. Additionally, the potential protective proteins induced by DMT1 silencing were related to insulin secretion that may lead to improving β-cell functions upon exposure to IL-1β. This global profiling has shed light on the signal transduction pathways driving the protection against inflammation-induced cell death in β-cells after DMT1 silencing.


Sign in / Sign up

Export Citation Format

Share Document