scholarly journals Melatonin Alleviates Acute Sleep Deprivation-Induced Memory Loss in Mice by Suppressing Hippocampal Ferroptosis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xintong Wang ◽  
Zixu Wang ◽  
Jing Cao ◽  
Yulan Dong ◽  
Yaoxing Chen
Keyword(s):  
Sleep Deprivation ◽  
Antioxidant Enzyme ◽  
Iron Homeostasis ◽  
Memory Loss ◽  
Blue Staining ◽  
Signal Pathways ◽  
Divalent Metal Transporter 1 ◽  
Study Objective ◽  
Divalent Metal Transporter

Objectives: Memory decline caused by insufficient sleep is a critical public health issues and currently lacks effective treatments. This study objective was to explore alleviative effect of melatonin on sleep deprivation (SD)-induced deficiencies in learning and memory.Materials and Methods: A continuous 72 h SD mouse model, with or without melatonin or Fer-1 supplementation were established. The changes of cognitive function, iron homeostasis, lipid peroxidation and intracellular signal pathways in mice were detected by Morris water maze, antioxidant assay, immunohistochemistry, western blot, RT-PCR and Prussian blue staining. In vitro, we treated HT-22 cells with ferroptosis inducer (Erastin) to further explore the specific mechanism of melatonin in ferroptosis.Results: Mice subjected to SD had significantly elevated latency and path length to reach hidden platform, as well as a decrease in number of entries and time spent in the target zone when the hidden platform was removed (p < 0.05). Nevertheless, supplementation with ferroptosis inhibitor (Fer-1) mitigated the memory impairment associated with SD. Further evaluation revealed an up-regulation of intracellular iron accumulation, transferrin receptor 1 and divalent metal transporter 1 expression and ROS and MDA production, and a down-regulation of ferroportin and antioxidant enzyme (GPX4 and SOD) expression in SD mice. SD decreased expression of MT2 receptor rather than of MT1, and inhibited ERK/Nrf2 signaling activation in the hippocampus (p < 0.05). In contrast, the aforementioned SD-inductions were reversed by supplementation using 20 and 40 mg/kg melatonin in SD mice. In vitro, melatonin pretreatment reversed Erastin-induced ferroptosis, abnormalities in iron transporter protein and antioxidant enzyme expression and suppression of ERK/Nrf2 signaling in HT-22 cells, however this protective effect of melatonin was blocked by MT2-, ERK- and Nrf2-specific antagonists (p < 0.05).Conclusion: Our finding suggested SD may induce ferroptosis, in turn leading to cognitive deficits. Melatonin alleviated memory loss and hippocampal ferroptosis caused by acute SD through binding to the MT2 receptor to activate ERK/Nrf2 signaling.

scholarly journals Interrelationships between circulating gastrin and iron status in mice and humans

2008 ◽  
Vol 295 (4) ◽  
pp. G855-G861 ◽  
Author(s):  
Suzana Kovac ◽  
Kelly Smith ◽  
Gregory J. Anderson ◽  
John R. Burgess ◽  
Arthur Shulkes ◽  
...  
Keyword(s):  
Iron Homeostasis ◽  
Iron Absorption ◽  
Iron Status ◽  
Transferrin Saturation ◽  
Wild Type ◽  
Liver Iron ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Mrna Concentration

The observations that the peptide hormone gastrin interacts with transferrin in vitro and that circulating gastrin concentrations are increased in the iron-loading disorder hemochromatosis suggest a possible link between gastrin and iron homeostasis. This study tested the hypothesis that gastrin and iron status are interrelated by measurement of iron homeostasis in mice and humans with abnormal circulating gastrin concentrations. Intestinal iron absorption was determined by59Fe uptake following oral gavage, and concentrations of duodenal divalent metal transporter-1 (DMT-1) and hepatic hepcidin mRNAs were determined by quantitative real-time PCR in agastrinemic (GasKO), hypergastrinemic cholecystokinin 2 receptor-deficient (CCK2RKO), or wild-type mice. Iron status was measured by standard methods in the same mice and in hypergastrinemic humans with multiple endocrine neoplasia type 1 (MEN-1). Iron absorption was increased sixfold and DMT-1 mRNA concentration fourfold, and transferrin saturation was reduced 0.8-fold and hepcidin mRNA expression 0.5-fold in juvenile GasKO mice compared with age-matched wild-type mice. In mature mice, few differences were observed between the strains. Juvenile CCK2RKO mice were hypergastrinemic and had a 5.4-fold higher DMT-1 mRNA concentration than wild-type mice without any increase in iron absorption. In contrast to juvenile GasKO mice, juvenile CCK2RKO mice had a 1.5-fold greater transferrin saturation, which was reflected in a twofold increase in liver iron deposition at maturity compared with wild-type mice. The correlation between transferrin saturation and circulating gastrin concentration observed in mutant mice was also observed in human patients with MEN, in whom hypergastrinemia correlated positively ( P = 0.004) with an increased transferrin saturation. Our data indicate that, in juvenile animals when iron demand is high, circulating gastrin concentrations may alter iron status by a CCK2R-independent mechanism.

Putative proteins involved in manganese transport across the blood-brain barr 1ier

2007 ◽  
Vol 26 (4) ◽  
pp. 295-302 ◽  
Author(s):  
Vanessa A Fitsanakis ◽  
Greg Piccola ◽  
Ana Paula Marreilha dos Santos ◽  
Judy L Aschner ◽  
Michael Aschner
Keyword(s):  
In Vitro Models ◽  
Complex Nature ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Culture Techniques ◽  
Metal Transporter ◽  
Blood Brain ◽  
Essential Nutrient ◽  
Manganese Transport

Manganese (Mn) is an essential nutrient required for proper growth and maintenance of numerous biological systems. At high levels it is known to be neurotoxic. While focused research concerning the transport of Mn across the blood-brain barrier (BBB) is on-going, the exact identity of the transporter(s) responsible is still debated. The transferrin receptor (TfR) and the divalent metal transporter-1 (DMT-1) have long been thought to play a role in brain Mn deposition. However, evidence suggests that Mn may also be transported by other proteins. One model system of the BBB, rat brain endothelial (RBE4) cells, are known to express many proteins suspected to be involved in metal transport. This review will discuss the biological importance of Mn, and then briefly describe several proteins that may be involved in transport of this metal across the BBB. The latter section will examine the potential usefulness of RBE4 cells in characterizing various aspects of Mn transport, and basic culture techniques involved in working with these cells. It is hoped that ideas put forth in this article will stimulate further investigations into the complex nature of Mn transport, and address the importance as well as the limitation of in vitro models in answering these questions. Human & Experimental Toxicology (2007) 26, 295-302

DMT1-Mutant Erythrocytes Have Shortened Life Span, Accelerated Glycolysis and Increased Oxidative Stress

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 957-957
Author(s):  
Zuzana Zidova ◽  
Pavla Pospisilova ◽  
Renata Mojzikova ◽  
Katarina Kapralova ◽  
Dalibor Dolezal ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Life Span ◽  
Conflicts Of Interest ◽  
Transmembrane Protein ◽  
Erythroid Differentiation ◽  
Compound Heterozygous ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter

Abstract Divalent metal transporter 1 (DMT1, also known as NRAMP2 and SLC11A2) is a transmembrane protein important for intestinal iron (Fe2+) absorption and erythroid iron utilization. Homozygous or compound heterozygous mutations in DMT1 are associated with moderate to severe hypochromic microcytic anemia in human patients and a mouse model - mk/mk mice. We have previously reported that DMT1 deficiency leads to an impaired erythroid differentiation hallmarked by accumulation of immature forms of erythroblast which also showed increased rate of apoptosis. For human samples we observed suppression of colony-forming capacity of erythroid progenitors that can be corrected by the addition of iron saturated chelate Fe-SIH. Later we proved this result also for mk/mk progenitors and showed reduced number of mk/mk CFU-E (164±25 vs. 283±50) and BFU-E (9±4 vs. 22±5) colonies in comparison to the colonies of wild-type (wt) mice and improvement of the colony growth with Fe-SIH. In our following studies we focused on mature erythrocytes, the last stage of erythroid differentiation that has not been analyzed yet. We first determined the in vivo half-life of red blood cells (RBC). Isolated RBCs from mk/mk mice and wt controls were in vitro labeled with CFSE fluorescent dye and injected into the wt mice. The intensity of RBCs fluorescence was measured on the 1st, 7th, 10th, 14th, 19th, 26th and 30th day following the injection. We observed an accelerated clearance of CFSE-labeled mk/mk RBCs from circulating blood when compared to wt RBCs, which indicates increased destruction of DMT1-mutant erythrocytes in vivo. It is known, that mature RBCs retain the ability to undergo stress-induced death (eryptosis), characterized by their shrinkage, membrane blebbing and phosphatidylserine surface exposure. This process may be triggered by iron deficiency. To determine the involvement of eryptosis in mk/mk RBCs clearance, RBCs were exposed to different stress conditions in vitro. A significantly increased number of Annexin V-positive RBCs was detected for mk/mk RBCs when compared to wt RBCs after 5 and 7 hour exposure to hyperosmotic shock (400mM sucrose) and glucose depletion, respectively. These results indicate shortened life span of DMT1-mutant erythrocytes and their reduced ability to cope with stress. To unravel the possible underlying mechanisms we focus on two processes important for RBC survival; anti-oxidative defense and anaerobic glycolysis. We observed 1.5 to 2-fold higher activity of glutathione peroxidase, catalase and methemoglobin reductase and elevated levels of methemoglobin in mk/mk RBCs in comparison to wt RBCs, indicating increased oxidative stress in mk/mk RBCs. Increased activity of hexokinase (2.5 times) and pyruvatkinase (2.4 times) together with reduced ratio of ATP/ADP in mk/mk mice compared with wt mice (from 2.89±0.56 μmol/L to 1.71±0.49 μmol/L) shows enhanced demand for glycolytically derived ATP to maintain the stability of RBC membrane in mk/mk mice. Our analyzes suggest that DMT1 deficiency negatively affects metabolism and life span of mature erythrocytes; two other aspects of defective erythropoiesis contributing to the pathophysiology of the disease. Grant support Czech Grant Agency, grant No. P305/11/1745; Ministry of Health Czech Republic Grant No. NT11208 and Internal Grant of Palacky University Olomouc (LF_2013_010). Disclosures: No relevant conflicts of interest to declare.

Effects of iron regulatory protein regulation on iron homeostasis during hypoxia

Blood ◽  
2003 ◽  
Vol 102 (9) ◽  
pp. 3404-3411 ◽  
Author(s):  
Brian D. Schneider ◽  
Elizabeth A. Leibold
Keyword(s):  
Iron Uptake ◽  
Iron Homeostasis ◽  
Rna Binding ◽  
Late Phase ◽  
Regulatory Protein ◽  
Binding Activity ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Iron Regulatory Proteins ◽  
Ft Synthesis

AbstractIron regulatory proteins (IRP1 and IRP2) are RNA-binding proteins that affect the translation and stabilization of specific mRNAs by binding to stem-loop structures known as iron responsive elements (IREs). IREs are found in the 5′-untranslated region (UTR) of ferritin (Ft) and mitochondrial aconitase (m-Aco) mRNAs, and in the 3′-UTR of transferrin receptor (TfR) and divalent metal transporter-1 (DMT1) mRNAs. Our previous studies show that besides iron, IRPs are regulated by hypoxia. Here we describe the consequences of IRP regulation and show that iron homeostasis is regulated in 2 phases during hypoxia: an early phase where IRP1 RNA-binding activity decreases and iron uptake and Ft synthesis increase, and a late phase where IRP2 RNA-binding activity increases and iron uptake and Ft synthesis decrease. The increase in iron uptake is independent of DMT1 and TfR, suggesting an unknown transporter. Unlike Ft, m-Aco is not regulated during hypoxia. During the late phase of hypoxia, IRP2 RNA-binding activity increases, becoming the dominant regulator responsible for decreasing Ft synthesis. During reoxygenation (ReO2), Ft protein increases concomitant with a decrease in IRP2 RNA-binding activity. The data suggest that the differential regulation of IRPs during hypoxia may be important for cellular adaptation to low oxygen tension.

scholarly journals EGCG Protects against 6-OHDA-Induced Neurotoxicity in a Cell Culture Model

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Dan Chen ◽  
Anumantha G. Kanthasamy ◽  
Manju B. Reddy
Keyword(s):  
Iron Metabolism ◽  
Iron Homeostasis ◽  
Regulatory Gene ◽  
Cell Uptake ◽  
Dopamine Depletion ◽  
Intracellular Iron ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Sytox Green ◽  
Gene And Protein Expression

Background. Parkinson’s disease (PD) is a progressive neurodegenerative disease that causes severe brain dopamine depletion. Disruption of iron metabolism may be involved in the PD progression.Objective. To test the protective effect of (−)-epigallocatechin-3-gallate (EGCG) against 6-hydroxydopamine- (6-OHDA-) induced neurotoxicity by regulating iron metabolism in N27 cells.Methods. Protection by EGCG in N27 cells was assessed by SYTOX green assay, MTT, and caspase-3 activity. Iron regulatory gene and protein expression were measured by RT-PCR and Western blotting. Intracellular iron uptake was measured using55Fe. The EGCG protection was further tested in primary mesencephalic dopaminergic neurons by immunocytochemistry.Results. EGCG protected against 6-OHDA-induced cell toxicity. 6-OHDA treatment significantly (p<0.05) increased divalent metal transporter-1 (DMT1) and hepcidin and decreased ferroportin 1 (Fpn1) level, whereas pretreatment with EGCG counteracted the effects. The increased55Fe (by 96%,p<0.01) cell uptake confirmed the iron burden by 6-OHDA and was reduced by EGCG by 27% (p<0.05), supporting the DMT1 results. Pretreatment with EGCG and 6-OHDA significantly increased (p<0.0001) TH+cell count (~3-fold) and neurite length (~12-fold) compared to 6-OHDA alone in primary mesencephalic neurons.Conclusions. Pretreatment with EGCG protected against 6-OHDA-induced neurotoxicity by regulating genes and proteins involved in brain iron homeostasis, especially modulating hepcidin levels.

Deregulation of proteins involved in iron metabolism in hepcidin-deficient mice

Blood ◽  
2005 ◽  
Vol 105 (12) ◽  
pp. 4861-4864 ◽  
Author(s):  
Lydie Viatte ◽  
Jeanne-Claire Lesbordes-Brion ◽  
Dan-Qing Lou ◽  
Myriam Bennoun ◽  
Gaël Nicolas ◽  
...  
Keyword(s):  
Iron Overload ◽  
Iron Homeostasis ◽  
Genetic Disorder ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Metal Transporter ◽  
The Common ◽  
Related Proteins ◽  
Deficient Mice

Abstract Evidence is accumulating that hepcidin, a liver regulatory peptide, could be the common pathogenetic denominator of all forms of iron overload syndromes including HFE-related hemochromatosis, the most prevalent genetic disorder characterized by inappropriate iron absorption. To understand the mechanisms whereby hepcidin controls iron homeostasis in vivo, we have analyzed the level of iron-related proteins by Western blot and immunohistochemistry in hepcidin-deficient mice, a mouse model of severe hemochromatosis. These mice showed important increased levels of duodenal cytochrome b (Dcytb), divalent metal transporter 1 (DMT1), and ferroportin compared with control mice. Interestingly, the level of ferroportin was coordinately up-regulated in the duodenum, the spleen, and the liver (predominantly in the Kupffer cells). Finally, we also evidenced a decrease of ceruloplasmin in the liver of hepcidin-deficient mice. We hypothesized that the deregulation of these proteins might be central in the pathogenesis of iron overload, providing key therapeutic targets for iron disorders. (Blood. 2005;105:4861-4864)

scholarly journals Skeletal Lipocalin-2 Is Associated with Iron-Related Oxidative Stress in ob/ob Mice with Sarcopenia

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 758
Author(s):  
Eun Bee Choi ◽  
Jae Hun Jeong ◽  
Hye Min Jang ◽  
Yu Jeong Ahn ◽  
Kyu Hyeon Kim ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Iron Homeostasis ◽  
Skeletal Muscle Regeneration ◽  
Lipocalin 2 ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Metal Transporter ◽  
Candidate Target ◽  
And Oxidative Stress

Obesity and insulin resistance accelerate aging-related sarcopenia, which is associated with iron load and oxidative stress. Lipocalin-2 (LCN2) is an iron-binding protein that has been associated with skeletal muscle regeneration, but details regarding its role in obese sarcopenia remain unclear. Here, we report that elevated LCN2 levels in skeletal muscle are linked to muscle atrophy-related inflammation and oxidative stress in leptin-deficient ob/ob mice. RNA sequencing analyses indicated the LCN2 gene expression is enhanced in skeletal muscle of ob/ob mice with sarcopenia. In addition to muscular iron accumulation in ob/ob mice, expressions of iron homeostasis-related divalent metal transporter 1, ferritin, and hepcidin proteins were increased in ob/ob mice compared to lean littermates, whereas expressions of transferrin receptor and ferroportin were reduced. Collectively, these findings demonstrate that LCN2 functions as a potent proinflammatory factor in skeletal muscle in response to obesity-related sarcopenia and is thus a therapeutic candidate target for sarcopenia treatment.

scholarly journals Hypoxia-inducible factor-2α but not hypoxia-inducible factor-1α increases iron traffic in astrocytes

2020 ◽  
Author(s):  
Manman Xu ◽  
Zhiqiang Chen ◽  
Xizhen Ma ◽  
Hangrui Xu ◽  
Changsheng Fan ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Ferrous Iron ◽  
Iron Homeostasis ◽  
Hypoxia Inducible Factor ◽  
Western Blots ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Kinase C ◽  
Cultured Astrocytes

Abstract Background: Disrupted iron homeostasis in the substantia nigra (SN) is an important mechanism in Parkinson’s disease (PD). In our previous studies using cultured neurons, we showed that 6-hydroxydopamine (6-OHDA) treatment increased the expression of divalent metal transporter-1 (DMT1) gating iron influx and decreased the expression of ferroportin 1 (FPN1) gating iron efflux, leading to increased iron deposition. In astrocytes, 6-OHDA increased both DMT1 and FPN1 expressions and iron traffic. However, the underlying mechanisms mediating these processes remain elusive. Hypoxia-inducible factors (HIFs) are important regulators of iron homeostasis.Methods: Using western blots, we observed HIFs, DMT1 and FPN1 expressions in primary cultured astrocytes and ventral mesencephalic (VM) treated with 6-OHDA, inhibitors of HIF-1α and HIF-2α, protein kinase C (PKC) inhibitor and PKC activator, radical scavenger and inducible NO synthase (iNOS) inhibitor . The ferrous iron traffic of astrocytes was determined by measuring the quenching or reversing of calcein fluorescence.Results: Using primary rat cell cultures, we observed that 6-OHDA treatment significantly increased the expressions of HIF-1α and HIF-2α in cultured astrocytes but not in VM neurons. Moreover, we observed that HIF-2α inhibitor, but not HIF-1α inhibitor reversed the 6-OHDA-induced upregulation of DMT1 and FPN1 and ferrous iron traffic. Blocking protein kinase C (PKC) pathway by bisindolylmaleimide I hydrochloride (Bisl) or N-acetyl-l-cysteine (NAC) or Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) inhibits Phorbol 12-myristate 13-acetate (PMA) or 6-OHDA induced activation of HIF-2α, whereas activating by PMA or 6-OHDA was sufficient to activate HIF-2α. Notably, blocking of PKC delta (PKC δ) phosphorylation by NAC, or L-NAME inhibits 6-OHDA induced activation of HIF-2α.Conclusion: Our data indicate that astrocytic HIF-2α, but not HIF-1α, may be an important regulator of DMT1 and FPN1 expressions by activating the PKC -dependent pathway.

scholarly journals Hypoxia-inducible factor 2α but not hypoxia-inducible factor-1α increases iron traffic in astrocytes

2020 ◽  
Author(s):  
Manman Xu ◽  
Zhiqiang Chen ◽  
Xizhen Ma ◽  
Hangrui Xu ◽  
Changsheng Fan ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Ferrous Iron ◽  
Iron Homeostasis ◽  
Hypoxia Inducible Factor ◽  
Western Blots ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Kinase C ◽  
Cultured Astrocytes

Abstract Background Disrupted iron homeostasis in the substantia nigra (SN) is an important mechanism in Parkinson’s disease (PD). In our previous studies using cultured neurons, we showed that 6-hydroxydopamine (6-OHDA) treatment increased the expression of divalent metal transporter-1 (DMT1) gating iron influx and decreased the expression of ferroportin 1 (FPN1) gating iron efflux, leading to increased iron deposition. In astrocytes, 6-OHDA increased both DMT1 and FPN1 expressions and iron traffic. However, the underlying mechanisms mediating these processes remain elusive. Hypoxia-inducible factors (HIFs) are important regulators of iron homeostasis. Methods Using western blots, we observed HIFs, DMT1 and FPN1 expressions in primary cultured astrocytes and ventral mesencephalic (VM) treated with 6-OHDA, inhibitors of HIF-1α and HIF-2α, protein kinase C (PKC) inhibitor and PKC activator, radical scavenger and inducible NO synthase (iNOS) inhibitor. The ferrous iron traffic of astrocytes was determined by measuring the quenching or reversing of calcein fluorescence. Results Using primary rat cell cultures, we observed that 6-OHDA treatment significantly increased the expressions of HIF-1α and HIF-2α in cultured astrocytes but not in VM neurons. Moreover, we observed that HIF-2α inhibitor, but not HIF-1α inhibitor reversed the 6-OHDA-induced upregulation of DMT1 and FPN1 and ferrous iron traffic. Blocking protein kinase C (PKC) pathway by bisindolylmaleimide I hydrochloride (Bisl) or N-acetyl-l-cysteine (NAC) or Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) inhibits Phorbol 12-myristate 13-acetate (PMA) or 6-OHDA induced activation of HIF-2α, whereas activating by PMA or 6-OHDA was sufficient to activate HIF-2α. Notably, blocking of PKC delta (PKC δ) phosphorylation by NAC, or L-NAME inhibits 6-OHDA induced activation of HIF-2α. Conclusion Our data indicate that astrocytic HIF-2α, but not HIF-1α, may be an important regulator of DMT1 and FPN1 expressions by activating the PKC -dependent pathway.

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