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Rao RB. Biomarkers of Brain Dysfunction in Perinatal Iron Deficiency. Nutrients 2024; 16:1092. [PMID: 38613125 PMCID: PMC11013337 DOI: 10.3390/nu16071092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/28/2024] [Accepted: 04/04/2024] [Indexed: 04/14/2024] Open
Abstract
Iron deficiency in the fetal and neonatal period (perinatal iron deficiency) bodes poorly for neurodevelopment. Given its common occurrence and the negative impact on brain development, a screening and treatment strategy that is focused on optimizing brain development in perinatal iron deficiency is necessary. Pediatric societies currently recommend a universal iron supplementation strategy for full-term and preterm infants that does not consider individual variation in body iron status and thus could lead to undertreatment or overtreatment. Moreover, the focus is on hematological normalcy and not optimal brain development. Several serum iron indices and hematological parameters in the perinatal period are associated with a risk of abnormal neurodevelopment, suggesting their potential use as biomarkers for screening and monitoring treatment in infants at risk for perinatal iron deficiency. A biomarker-based screening and treatment strategy that is focused on optimizing brain development will likely improve outcomes in perinatal iron deficiency.
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Affiliation(s)
- Raghavendra B. Rao
- Division of Neonatology, Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN 55455, USA;
- Masonic Institute for the Developing Brain, Minneapolis, MN 55414, USA
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2
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Sandri BJ, Kim J, Lubach GR, Lock EF, Ennis-Czerniak K, Kling PJ, Georgieff MK, Coe CL, Rao RB. Prognostic Performance of Hematological and Serum Iron and Metabolite Indices for Detection of Early Iron Deficiency Induced Metabolic Brain Dysfunction in Infant Rhesus Monkeys. J Nutr 2024; 154:875-885. [PMID: 38072152 PMCID: PMC10942850 DOI: 10.1016/j.tjnut.2023.10.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/18/2023] [Accepted: 10/25/2023] [Indexed: 12/27/2023] Open
Abstract
BACKGROUND The current pediatric practice of monitoring for infantile iron deficiency (ID) via hemoglobin (Hgb) screening at one y of age does not identify preanemic ID nor protect against later neurocognitive deficits. OBJECTIVES To identify biomarkers of iron-related metabolic alterations in the serum and brain and determine the sensitivity of conventional iron and heme indices for predicting risk of brain metabolic dysfunction using a nonhuman primate model of infantile ID. METHODS Simultaneous serum iron and RBC indices, and serum and cerebrospinal fluid (CSF) metabolomic profiles were determined in 20 rhesus infants, comparing iron sufficient (IS; N = 10) and ID (N = 10) infants at 2 and 4 mo of age. RESULTS Reticulocyte hemoglobin (RET-He) was lower at 2 wk in the ID group. Significant IS compared with ID differences in serum iron indices were present at 2 mo, but Hgb and RBC indices differed only at 4 mo (P < 0.05). Serum and CSF metabolomic profiles of the ID and IS groups differed at 2 and 4 mo (P < 0.05). Key metabolites, including homostachydrine and stachydrine (4-5-fold lower at 4 mo in ID group, P < 0.05), were altered in both serum and CSF. Iron indices and RET-He at 2 mo, but not Hgb or other RBC indices, were correlated with altered CSF metabolic profile at 4 mo and had comparable predictive accuracy (area under the receiver operating characteristic curve scores, 0.75-0.80). CONCLUSIONS Preanemic ID at 2 mo was associated with metabolic alterations in serum and CSF in infant monkeys. Among the RBC indices, only RET-He predicted the future risk of abnormal CSF metabolic profile with a predictive accuracy comparable to serum iron indices. The concordance of homostachydrine and stachydrine changes in serum and CSF indicates their potential use as early biomarkers of brain metabolic dysfunction in infantile ID.
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Affiliation(s)
- Brian J Sandri
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States; Masonic Institute for the Developing Brain, University of Minnesota, Minneapolis, MN, United States
| | - Jonathan Kim
- Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, United States
| | - Gabriele R Lubach
- Harlow Center for Biological Psychology, University of Wisconsin, Madison, WI, United States
| | - Eric F Lock
- Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, United States
| | - Kathleen Ennis-Czerniak
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States
| | - Pamela J Kling
- Division of Neonatology, Department of Pediatrics, University of Wisconsin, Madison, WI, United States
| | - Michael K Georgieff
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States; Masonic Institute for the Developing Brain, University of Minnesota, Minneapolis, MN, United States
| | - Christopher L Coe
- Harlow Center for Biological Psychology, University of Wisconsin, Madison, WI, United States
| | - Raghavendra B Rao
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States; Masonic Institute for the Developing Brain, University of Minnesota, Minneapolis, MN, United States.
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Pan S, Hale AT, Lemieux ME, Raval DK, Garton TP, Sadler B, Mahaney KB, Strahle JM. Iron homeostasis and post-hemorrhagic hydrocephalus: a review. Front Neurol 2024; 14:1287559. [PMID: 38283681 PMCID: PMC10811254 DOI: 10.3389/fneur.2023.1287559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Accepted: 11/21/2023] [Indexed: 01/30/2024] Open
Abstract
Iron physiology is regulated by a complex interplay of extracellular transport systems, coordinated transcriptional responses, and iron efflux mechanisms. Dysregulation of iron metabolism can result in defects in myelination, neurotransmitter synthesis, and neuronal maturation. In neonates, germinal matrix-intraventricular hemorrhage (GMH-IVH) causes iron overload as a result of blood breakdown in the ventricles and brain parenchyma which can lead to post-hemorrhagic hydrocephalus (PHH). However, the precise mechanisms by which GMH-IVH results in PHH remain elusive. Understanding the molecular determinants of iron homeostasis in the developing brain may lead to improved therapies. This manuscript reviews the various roles iron has in brain development, characterizes our understanding of iron transport in the developing brain, and describes potential mechanisms by which iron overload may cause PHH and brain injury. We also review novel preclinical treatments for IVH that specifically target iron. Understanding iron handling within the brain and central nervous system may provide a basis for preventative, targeted treatments for iron-mediated pathogenesis of GMH-IVH and PHH.
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Affiliation(s)
- Shelei Pan
- Department of Neurosurgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Andrew T. Hale
- Department of Neurosurgery, University of Alabama at Birmingham School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mackenzie E. Lemieux
- Department of Neurosurgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Dhvanii K. Raval
- Department of Neurosurgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Thomas P. Garton
- Department of Neurology, Johns Hopkins University School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Brooke Sadler
- Department of Pediatrics, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Hematology and Oncology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Kelly B. Mahaney
- Department of Neurosurgery, Stanford University School of Medicine, Stanford University, Palo Alto, CA, United States
| | - Jennifer M. Strahle
- Department of Neurosurgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Pediatrics, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Orthopedic Surgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
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Sandri BJ, Ennis-Czerniak K, Kanajam P, Frey WH, Lock EF, Rao RB. Intranasal insulin treatment partially corrects the altered gene expression profile in the hippocampus of developing rats with perinatal iron deficiency. Am J Physiol Regul Integr Comp Physiol 2023; 325:R423-R432. [PMID: 37602386 PMCID: PMC10639019 DOI: 10.1152/ajpregu.00311.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 07/17/2023] [Accepted: 08/09/2023] [Indexed: 08/22/2023]
Abstract
Perinatal iron deficiency (FeD) targets the hippocampus and leads to long-term cognitive deficits. Intranasal insulin administration improves cognitive deficits in adult humans with Alzheimer's disease and type 2 diabetes and could provide benefits in FeD-induced hippocampal dysfunction. To objective was to assess the effects of intranasal insulin administration intranasal insulin administration on the hippocampal transcriptome in a developing rat model of perinatal FeD. Perinatal FeD was induced using low-iron diet from gestational day 3 until postnatal day (P) 7, followed by an iron sufficient (FeS) diet through P21. Intranasal insulin was administered at a dose of 0.3 IU twice daily from P8 to P21. Hippocampi were removed on P21 from FeS control, FeD control, FeS insulin, and FeD insulin groups. Total RNA was isolated and profiled using next-generation sequencing. Gene expression profiles were characterized using custom workflows and expression patterns examined using ingenuity pathways analysis (n = 7-9 per group). Select RNAseq results were confirmed via qPCR. Transcriptomic profiling revealed that mitochondrial biogenesis and flux, oxidative phosphorylation, quantity of neurons, CREB signaling in neurons, and RICTOR-based mTOR signaling were disrupted with FeD and positively affected by intranasal insulin treatment with the most benefit observed in the FeD insulin group. Both perinatal FeD and intranasal insulin administration altered gene expression profile in the developing hippocampus. Intranasal insulin treatment reversed the adverse effects of FeD on many molecular pathways and could be explored as an adjunct therapy in perinatal FeD.
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Affiliation(s)
- Brian J Sandri
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, United States
- Masonic Institute for the Developing Brain, University of Minnesota, Minneapolis, Minnesota, United States
| | - Kathleen Ennis-Czerniak
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, United States
| | - Priya Kanajam
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, United States
| | - William H Frey
- HealthPartners Center for Memory and Aging, HealthPartners Neurosciences, St. Paul, Minnesota, United States
| | - Eric F Lock
- Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, Minnesota, United States
| | - Raghavendra B Rao
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, United States
- Masonic Institute for the Developing Brain, University of Minnesota, Minneapolis, Minnesota, United States
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Abstract
Air pollution is a complex mixture of gases and particulate matter, with adsorbed organic and inorganic contaminants, to which exposure is lifelong. Epidemiological studies increasingly associate air pollution with multiple neurodevelopmental disorders and neurodegenerative diseases, findings supported by experimental animal models. This breadth of neurotoxicity across these central nervous system diseases and disorders likely reflects shared vulnerability of their inflammatory and oxidative stress-based mechanisms and a corresponding ability to produce brain metal dyshomeo-stasis. Future research to define the responsible contaminants of air pollution underlying this neurotoxicity is critical to understanding mechanisms of these diseases and disorders and protecting public health.
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Affiliation(s)
- Deborah A Cory-Slechta
- Department of Environmental Medicine, University of Rochester School of Medicine, Rochester, New York, USA;
| | - Alyssa Merrill
- Department of Environmental Medicine, University of Rochester School of Medicine, Rochester, New York, USA;
| | - Marissa Sobolewski
- Department of Environmental Medicine, University of Rochester School of Medicine, Rochester, New York, USA;
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Eckard ML, Marvin E, Conrad K, Oberdörster G, Sobolewski M, Cory-Slechta DA. Neonatal exposure to ultrafine iron but not combined iron and sulfur aerosols recapitulates air pollution-induced impulsivity in mice. Neurotoxicology 2023; 94:191-205. [PMID: 36509212 PMCID: PMC9839645 DOI: 10.1016/j.neuro.2022.12.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/07/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022]
Abstract
Air pollution (AP) is becoming recognized as a major threat to neurological health across the lifespan with increased risk of both neurodevelopmental and neurodegenerative disorders. AP is a complex mixture of gases and particulate matter, with adsorbed contaminants including metals and trace elements, which may differentially contribute to its neurodevelopmental impacts. Iron (Fe) is one of the most abundant metals found in AP, and Fe concentrations may drive some behavioral deficits observed in children. Furthermore, brains of neonate mice exposed to concentrated ambient ultrafine particulate matter (UFP) show significant brain accumulation of Fe and sulfur (S) supporting the hypothesis that AP exposure may lead to brain metal dyshomeostasis. The current study determined the extent to which behavioral effects of UFP, namely memory deficits and impulsive-like behavior, could be recapitulated with exposure to Fe aerosols with or without concomitant SO2. Male and female neonate mice were either exposed to filtered air or spark discharge-generated ultrafine Fe particles with or without SO2 gas (n = 12/exposure/sex). Inhalation exposures occurred from postnatal day (PND) 4-7 and 10-13 for 4 hr/day, mirroring our previous UFP exposures. Mice were aged to adulthood prior to behavioral testing. While Fe or Fe + SO2 exposure did not affect gross locomotor behavior, Fe + SO2-exposed females displayed consistent thigmotaxis during locomotor testing. Neither exposure affected novel object memory. Fe or Fe + SO2 exposure produced differential outcomes on a fixed-interval reinforcement schedule with males showing higher (Fe-only) or lower (Fe + SO2) response rates and postreinforcement pauses (PRP) and females showing higher (Fe-only) PRP. Lastly, Fe-exposed, but not Fe + SO2-exposed, males showed increased impulsive-like behavior in tasks requiring response inhibition with no such effects in female mice. These findings suggest that: 1) exposure to realistic concentrations of Fe aerosols can recapitulate behavioral effects of UFP exposure, 2) the presence of SO2 can modulate behavioral effects of Fe inhalation, and 3) brain metal dyshomeostasis may be an important factor in AP neurotoxicity.
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Affiliation(s)
- M L Eckard
- Department of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA; Department of Psychology, Radford University, Radford, VA, USA.
| | - E Marvin
- Department of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA
| | - K Conrad
- Department of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA
| | - G Oberdörster
- Department of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA
| | - M Sobolewski
- Department of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA
| | - D A Cory-Slechta
- Department of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA
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Sandri BJ, Kim J, Lubach GR, Lock EF, Guerrero C, Higgins L, Markowski TW, Kling PJ, Georgieff MK, Coe CL, Rao RB. Multiomic Profiling of Iron Deficient Infant Monkeys Reveals Alterations in Neurologically Important Biochemicals in Serum and CSF Prior to the Onset of Anemia. Am J Physiol Regul Integr Comp Physiol 2022; 322:R486-R500. [PMID: 35271351 DOI: 10.1152/ajpregu.00235.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND The effects of iron deficiency (ID) during infancy extend beyond the hematologic compartment and include short- and long-term adverse effects on many tissues including the brain. However, sensitive biomarkers of iron-dependent brain health are lacking in humans. OBJECTIVE To determine whether serum and CSF biomarkers of ID-induced metabolic dysfunction are concordant in the pre/early anemic stage of ID prior to anemia in a nonhuman primate model of infantile IDA. METHODS Paired serum and CSF specimens were collected from iron-sufficient (IS; n = 12) and ID (n = 7) rhesus infants at 4-months (pre-anemic period) and 6-months of age (anemic). Hematological, metabolomic, and proteomic profiles were generated via HPLC/MS at both time points to discriminate serum bio markers of ID-induced brain metabolic dysfunction. RESULTS We identified 227 metabolites and 205 proteins in serum. Abnormalities indicating altered liver function, lipid dysregulation, and increased acute phase reactants were present in ID. In CSF, we measured 210 metabolites and 1,560 proteins with changes in ID infants indicative of metabolomic and proteomic differences indexing disrupted synaptogenesis. Systemic and CSF proteomic and metabolomic changes were present and concurrent in the pre-anemic and anemic periods. CONCLUSIONS Multiomic serum and CSF profiling uncovered pathways disrupted by ID in both the pre-anemic and anemic stages of infantile IDA, including evidence for hepatic dysfunction and activation of acute phase response. Parallel changes observed in serum and CSF potentially provide measurable serum biomarkers of ID that reflect at-risk brain processes prior to progression to clinical anemia.
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Affiliation(s)
- Brian J Sandri
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States.,Masonic Institute for the Developing Brain, University of Minnesota, Minneapolis, MN, United States
| | - Jonathan Kim
- Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, United States
| | - Gabriele R Lubach
- Harlow Center for Biological Psychology, University of Wisconsin, Madison, WI, United States
| | - Eric F Lock
- Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, United States
| | - Candace Guerrero
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - LeeAnn Higgins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Todd W Markowski
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Pamela J Kling
- Division of Neonatology, Department of Pediatrics, University of Wisconsin, Madison, WI, United States
| | - Michael K Georgieff
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States.,Masonic Institute for the Developing Brain, University of Minnesota, Minneapolis, MN, United States
| | - Christopher L Coe
- Harlow Center for Biological Psychology, University of Wisconsin, Madison, WI, United States
| | - Raghavendra B Rao
- Division of Neonatology, Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States.,Masonic Institute for the Developing Brain, University of Minnesota, Minneapolis, MN, United States
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Trivedi A, Tercovich KG, Casbon AJ, Raber J, Lowell C, Noble-Haeusslein LJ. Neutrophil-specific deletion of Syk results in recruitment-independent stabilization of the barrier and a long-term improvement in cognitive function after traumatic injury to the developing brain. Neurobiol Dis 2021; 157:105430. [PMID: 34153467 PMCID: PMC11302380 DOI: 10.1016/j.nbd.2021.105430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 05/14/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
While traumatic brain injury (TBI) is the leading cause of death and disability in children, we have yet to identify those pathogenic events that determine the extent of recovery. Neutrophils are best known as "first responders" to sites of infection and trauma where they become fully activated, killing pathogens via proteases that are released during degranulation. However, this activational state may generate substantial toxicity in the young brain after TBI that is partially due to developmentally regulated inadequate antioxidant reserves. Neutrophil degranulation is triggered via a downstream signaling pathway that is dependent on spleen tyrosine kinase (Syk). To test the hypothesis that the activational state of neutrophils is a determinant of early pathogenesis and long-term recovery, we compared young, brain-injured conditional knockouts of Syk (sykf/fMRP8-cre+) to congenic littermates (sykf/f). Based upon flow cytometry, there was an extended recruitment of distinct leukocyte subsets, including Ly6G+/Ly6C- and Ly6G+/Ly6Cint, over the first several weeks post-injury which was similar between genotypes. Subsequent assessment of the acutely injured brain revealed a reduction in blood-brain barrier disruption to both high and low molecular weight dextrans and reactive oxygen species in sykf/fMRP8-cre+ mice compared to congenic littermates, and this was associated with greater preservation of claudin 5 and neuronal integrity, as determined by Western blot analyses. At adulthood, motor learning was less affected in brain-injured sykf/fMRP8-cre+ mice as compared to sykf/f mice. Performance in the Morris Water Maze revealed a robust improvement in hippocampal-dependent acquisition and short and long-term spatial memory retention in sykf/fMRP8-cre+ mice. Subsequent analyses of swim path lengths during hidden platform training and probe trials showed greater thigmotaxis in brain-injured sykf/f mice than sham sykf/f mice and injured sykf/fMRP8-cre+ mice. Our results establish the first mechanistic link between the activation state of neutrophils and long-term functional recovery after traumatic injury to the developing brain. These results also highlight Syk kinase as a novel therapeutic target that could be further developed for the brain-injured child.
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Affiliation(s)
- Alpa Trivedi
- Departments of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA; Departments of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA.
| | - Kayleen G Tercovich
- Departments of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Amy Jo Casbon
- Departments of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA
| | - Jacob Raber
- Departments of Behavioral Neuroscience, Neurology, and Radiation Medicine, ONPRC, Oregon Health & Science University, Portland, OR 97239, USA; Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Clifford Lowell
- Departments of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA.
| | - Linda J Noble-Haeusslein
- Departments of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA; Departments of Neurology and Psychology, The Dell Medical School and the College of Liberal Arts, University of Texas, Austin, TX 78712, USA.
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9
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Strahle JM, Mahaney KB, Morales DM, Buddhala C, Shannon CN, Wellons JC, Kulkarni AV, Jensen H, Reeder RW, Holubkov R, Riva-Cambrin JK, Whitehead WE, Rozzelle CJ, Tamber M, Pollack IF, Naftel RP, Kestle JRW, Limbrick DD. Longitudinal CSF Iron Pathway Proteins in Posthemorrhagic Hydrocephalus: Associations with Ventricle Size and Neurodevelopmental Outcomes. Ann Neurol 2021; 90:217-226. [PMID: 34080727 DOI: 10.1002/ana.26133] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/27/2021] [Accepted: 05/15/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Iron has been implicated in the pathogenesis of brain injury and hydrocephalus after preterm germinal matrix hemorrhage-intraventricular hemorrhage, however, it is unknown how external or endogenous intraventricular clearance of iron pathway proteins affect the outcome in this group. METHODS This prospective multicenter cohort included patients with posthemorrhagic hydrocephalus (PHH) who underwent (1) temporary and permanent cerebrospinal fluid (CSF) diversion and (2) Bayley Scales of Infant Development-III testing around 2 years of age. CSF proteins in the iron handling pathway were analyzed longitudinally and compared to ventricle size and neurodevelopmental outcomes. RESULTS Thirty-seven patients met inclusion criteria with a median estimated gestational age at birth of 25 weeks; 65% were boys. Ventricular CSF levels of hemoglobin, iron, total bilirubin, and ferritin decreased between temporary and permanent CSF diversion with no change in CSF levels of ceruloplasmin, transferrin, haptoglobin, and hepcidin. There was an increase in CSF hemopexin during this interval. Larger ventricle size at permanent CSF diversion was associated with elevated CSF ferritin (p = 0.015) and decreased CSF hemopexin (p = 0.007). CSF levels of proteins at temporary CSF diversion were not associated with outcome, however, higher CSF transferrin at permanent CSF diversion was associated with improved cognitive outcome (p = 0.015). Importantly, longitudinal change in CSF iron pathway proteins, ferritin (decrease), and transferrin (increase) were associated with improved cognitive (p = 0.04) and motor (p = 0.03) scores and improved cognitive (p = 0.04), language (p = 0.035), and motor (p = 0.008) scores, respectively. INTERPRETATION Longitudinal changes in CSF transferrin (increase) and ferritin (decrease) are associated with improved neurodevelopmental outcomes in neonatal PHH, with implications for understanding the pathogenesis of poor outcomes in PHH. ANN NEUROL 2021;90:217-226.
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Affiliation(s)
- Jennifer M Strahle
- Department of Neurosurgery, Washington University St. Louis, St. Louis, MO, USA
| | - Kelly B Mahaney
- Department of Neurosurgery, Stanford University, Palo Alto, CA, USA
| | - Diego M Morales
- Department of Neurosurgery, Washington University St. Louis, St. Louis, MO, USA
| | - Chandana Buddhala
- Department of Neurosurgery, Washington University St. Louis, St. Louis, MO, USA
| | - Chevis N Shannon
- Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John C Wellons
- Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Abhaya V Kulkarni
- Department of Neurosurgery, University of Toronto, Toronto, Ontario, Canada
| | - Hailey Jensen
- Data Coordinating Center, University of Utah, Salt Lake City, UT, USA
| | - Ron W Reeder
- Data Coordinating Center, University of Utah, Salt Lake City, UT, USA
| | - Richard Holubkov
- Data Coordinating Center, University of Utah, Salt Lake City, UT, USA
| | - Jay K Riva-Cambrin
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | | | - Curtis J Rozzelle
- Department of Neurosurgery, University of Alabama - Birmingham, Birmingham, AL, USA
| | - Mandeep Tamber
- Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ian F Pollack
- Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Robert P Naftel
- Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John R W Kestle
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA
| | - David D Limbrick
- Department of Neurosurgery, Washington University St. Louis, St. Louis, MO, USA
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10
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Gozt A, Hellewell S, Ward PGD, Bynevelt M, Fitzgerald M. Emerging Applications for Quantitative Susceptibility Mapping in the Detection of Traumatic Brain Injury Pathology. Neuroscience 2021; 467:218-236. [PMID: 34087394 DOI: 10.1016/j.neuroscience.2021.05.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/16/2022]
Abstract
Traumatic brain injury (TBI) is a common but heterogeneous injury underpinned by numerous complex and interrelated pathophysiological mechanisms. An essential trace element, iron is abundant within the brain and involved in many fundamental neurobiological processes, including oxygen transportation, oxidative phosphorylation, myelin production and maintenance, as well as neurotransmitter synthesis and metabolism. Excessive levels of iron are neurotoxic and thus iron homeostasis is tightly regulated in the brain, however, many details about the mechanisms by which this is achieved are yet to be elucidated. A key mediator of oxidative stress, mitochondrial dysfunction and neuroinflammatory response, iron dysregulation is an important contributor to secondary injury in TBI. Advances in neuroimaging that leverage magnetic susceptibility properties have enabled increasingly comprehensive investigations into the distribution and behaviour of iron in the brain amongst healthy individuals as well as disease states such as TBI. Quantitative Susceptibility Mapping (QSM) is an advanced neuroimaging technique that promises quantitative estimation of local magnetic susceptibility at the voxel level. In this review, we provide an overview of brain iron and its homeostasis, describe recent advances enabling applications of QSM within the context of TBI and summarise the current state of the literature. Although limited, the emergent research suggests that QSM is a promising neuroimaging technique that can be used to investigate a host of pathophysiological changes that are associated with TBI.
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Affiliation(s)
- Aleksandra Gozt
- Curtin University, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Bentley, WA Australia; Perron Institute for Neurological and Translational Science, Nedlands, WA Australia
| | - Sarah Hellewell
- Curtin University, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Bentley, WA Australia
| | - Phillip G D Ward
- Australian Research Council Centre of Excellence for Integrative Brain Function, VIC Australia; Turner Institute for Brain and Mental Health, Monash University, VIC Australia
| | - Michael Bynevelt
- Neurological Intervention and Imaging Service of Western Australia, Sir Charles Gairdner Hospital, Nedlands, WA Australia
| | - Melinda Fitzgerald
- Curtin University, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Bentley, WA Australia; Perron Institute for Neurological and Translational Science, Nedlands, WA Australia.
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11
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McMillen S, Lönnerdal B. Postnatal Iron Supplementation with Ferrous Sulfate vs. Ferrous Bis-Glycinate Chelate: Effects on Iron Metabolism, Growth, and Central Nervous System Development in Sprague Dawley Rat Pups. Nutrients 2021; 13:1406. [PMID: 33921980 PMCID: PMC8143548 DOI: 10.3390/nu13051406] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/18/2021] [Accepted: 04/20/2021] [Indexed: 02/05/2023] Open
Abstract
Iron-fortified formulas and iron drops (both usually ferrous sulfate, FS) prevent early life iron deficiency, but may delay growth and adversely affect neurodevelopment by providing excess iron. We used a rat pup model to investigate iron status, growth, and development outcomes following daily iron supplementation (10 mg iron/kg body weight, representative of iron-fortified formula levels) with FS or an alternative, bioavailable form of iron, ferrous bis-glycinate chelate (FC). On postnatal day (PD) 2, sex-matched rat litters (n = 3 litters, 10 pups each) were randomly assigned to receive FS, FC, or vehicle control until PD 14. On PD 15, we evaluated systemic iron regulation and CNS mineral interactions and we interrogated iron loading outcomes in the hippocampus, in search of mechanisms by which iron may influence neurodevelopment. Body iron stores were elevated substantially in iron-supplemented pups. All pups gained weight normally, but brain size on PD 15 was dependent on iron source. This may have been associated with reduced hippocampal oxidative stress but was not associated with CNS mineral interactions, iron regulation, or myelination, as these were unchanged with iron supplementation. Additional studies are warranted to investigate iron form effects on neurodevelopment so that iron recommendations can be optimized for all infants.
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Affiliation(s)
| | - Bo Lönnerdal
- Department of Nutrition, University of California, Davis, CA 95616, USA;
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12
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Air Pollution-Related Brain Metal Dyshomeostasis as a Potential Risk Factor for Neurodevelopmental Disorders and Neurodegenerative Diseases. ATMOSPHERE 2020. [DOI: 10.3390/atmos11101098] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Increasing evidence links air pollution (AP) exposure to effects on the central nervous system structure and function. Particulate matter AP, especially the ultrafine (nanoparticle) components, can carry numerous metal and trace element contaminants that can reach the brain in utero and after birth. Excess brain exposure to either essential or non-essential elements can result in brain dyshomeostasis, which has been implicated in both neurodevelopmental disorders (NDDs; autism spectrum disorder, schizophrenia, and attention deficit hyperactivity disorder) and neurodegenerative diseases (NDGDs; Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and amyotrophic lateral sclerosis). This review summarizes the current understanding of the extent to which the inhalational or intranasal instillation of metals reproduces in vivo the shared features of NDDs and NDGDs, including enlarged lateral ventricles, alterations in myelination, glutamatergic dysfunction, neuronal cell death, inflammation, microglial activation, oxidative stress, mitochondrial dysfunction, altered social behaviors, cognitive dysfunction, and impulsivity. Although evidence is limited to date, neuronal cell death, oxidative stress, and mitochondrial dysfunction are reproduced by numerous metals. Understanding the specific contribution of metals/trace elements to this neurotoxicity can guide the development of more realistic animal exposure models of human AP exposure and consequently lead to a more meaningful approach to mechanistic studies, potential intervention strategies, and regulatory requirements.
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13
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Lajqi T, Stojiljkovic M, Williams DL, Hudalla H, Bauer M, Witte OW, Wetzker R, Bauer R, Schmeer C. Memory-Like Responses of Brain Microglia Are Controlled by Developmental State and Pathogen Dose. Front Immunol 2020; 11:546415. [PMID: 33101271 PMCID: PMC7546897 DOI: 10.3389/fimmu.2020.546415] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/14/2020] [Indexed: 01/01/2023] Open
Abstract
Microglia, the innate immune cells of the central nervous system, feature adaptive immune memory with implications for brain homeostasis and pathologies. However, factors involved in the emergence and regulation of these opposing responses in microglia have not been fully addressed. Recently, we showed that microglia from the newborn brain display features of trained immunity and immune tolerance after repeated contact with pathogens in a dose-dependent manner. Here, we evaluate the impact of developmental stage on adaptive immune responses of brain microglia after repeated challenge with ultra-low (1 fg/ml) and high (100 ng/ml) doses of the endotoxin LPS in vitro. We find that priming of naïve microglia derived from newborn but not mature and aged murine brain with ultra-low LPS significantly increased levels of pro-inflammatory mediators TNF-α, IL-6, IL-1β, MMP-9, and iNOS as well as neurotrophic factors indicating induction of trained immunity (p < 0.05). In contrast, stimulation with high doses of LPS led to a robust downregulation of pro-inflammatory cytokines and iNOS independent of the developmental state, indicating induced immune tolerance. Furthermore, high-dose priming with LPS upregulated anti-inflammatory mediators IL-10, Arg-1, TGF- β, MSR1, and IL-4 in newborn microglia (p < 0.05). Our data indicate pronounced plasticity of the immune response of neonate microglia compared with microglia derived from mature and aged mouse brain. Induced trained immunity after priming with ultra-low LPS doses may be responsible for enhanced neuro-inflammatory susceptibility of immature brain. In contrast, the immunosuppressed phenotype following high-dose LPS priming might be prone to attenuate excessive damage after recurrent systemic inflammation.
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Affiliation(s)
- Trim Lajqi
- Institute of Molecular Cell Biology, Jena University Hospital, Jena, Germany.,Department of Neonatology, Heidelberg University Children's Hospital, Heidelberg, Germany
| | - Milan Stojiljkovic
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - David L Williams
- Department of Surgery and Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Hannes Hudalla
- Department of Neonatology, Heidelberg University Children's Hospital, Heidelberg, Germany
| | - Michael Bauer
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany
| | - Otto W Witte
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany.,Jena Center for Healthy Aging, Jena University Hospital, Jena, Germany
| | - Reinhard Wetzker
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany
| | - Reinhard Bauer
- Institute of Molecular Cell Biology, Jena University Hospital, Jena, Germany
| | - Christian Schmeer
- Hans-Berger Department of Neurology, Jena University Hospital, Jena, Germany
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14
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Bastian TW, Rao R, Tran PV, Georgieff MK. The Effects of Early-Life Iron Deficiency on Brain Energy Metabolism. Neurosci Insights 2020; 15:2633105520935104. [PMID: 32637938 PMCID: PMC7324901 DOI: 10.1177/2633105520935104] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 05/28/2020] [Indexed: 12/14/2022] Open
Abstract
Iron deficiency (ID) is one of the most prevalent nutritional deficiencies in the world. Iron deficiency in the late fetal and newborn period causes abnormal cognitive performance and emotional regulation, which can persist into adulthood despite iron repletion. Potential mechanisms contributing to these impairments include deficits in brain energy metabolism, neurotransmission, and myelination. Here, we comprehensively review the existing data that demonstrate diminished brain energetic capacity as a mechanistic driver of impaired neurobehavioral development due to early-life (fetal-neonatal) ID. We further discuss a novel hypothesis that permanent metabolic reprogramming, which occurs during the period of ID, leads to chronically impaired neuronal energetics and mitochondrial capacity in adulthood, thus limiting adult neuroplasticity and neurobehavioral function. We conclude that early-life ID impairs energy metabolism in a brain region- and age-dependent manner, with particularly strong evidence for hippocampal neurons. Additional studies, focusing on other brain regions and cell types, are needed.
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Affiliation(s)
- Thomas W Bastian
- Department of Pediatrics, Medical School, University of Minnesota, Minneapolis, MN, USA
| | - Raghavendra Rao
- Department of Pediatrics, Medical School, University of Minnesota, Minneapolis, MN, USA
| | - Phu V Tran
- Department of Pediatrics, Medical School, University of Minnesota, Minneapolis, MN, USA
| | - Michael K Georgieff
- Department of Pediatrics, Medical School, University of Minnesota, Minneapolis, MN, USA
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15
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Association between anemia and maternal depression: A systematic review and meta-analysis. J Psychiatr Res 2020; 122:88-96. [PMID: 31945502 DOI: 10.1016/j.jpsychires.2020.01.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 11/22/2019] [Accepted: 01/06/2020] [Indexed: 12/24/2022]
Abstract
Previous observational epidemiological studies have reported inconsistent findings regarding the association between anemia and the risk of maternal depression. In the present study, we investigated the relationship between anemia and the risk of maternal depression using a meta-analysis. We searched PubMed, EMBASE, and the bibliographies of relevant articles in May 2019. Three evaluators independently reviewed and selected the eligible studies based on the predetermined selection criteria. A random-effects model was employed to calculate meta-estimates of the association between anemia and maternal depression. Of the 1305 articles, 15 observational epidemiological studies (five case-control studies and 10 cohort studies) were included in the final analysis. A total of 32,792,378 women were included. Anemia was significantly associated with an increased risk of maternal depression in the random-effects meta-analysis of 15 studies (OR/RR: 1.53, 95% CI: 1.32-1.78). The association was consistent in both antepartum (OR/RR: 1.36, 95% CI: 1.07-1.72) and postpartum depression (OR/RR: 1.53, 95% CI: 1.32-1.78). Subgroup meta-analyses based on definition of anemia, definition of depression, and methodological quality reported consistent findings. The current meta-analysis showed that anemia was associated with an increased risk of maternal depression.
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16
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Bakulski KM, Seo YA, Hickman RC, Brandt D, Vadari HS, Hu H, KyunPark S. Heavy Metals Exposure and Alzheimer's Disease and Related Dementias. J Alzheimers Dis 2020; 76:1215-1242. [PMID: 32651318 PMCID: PMC7454042 DOI: 10.3233/jad-200282] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease and related dementias lack effective treatment or cures and are major public health challenges. Risk for Alzheimer's disease and related dementias is partially attributable to environmental factors. The heavy metals lead, cadmium, and manganese are widespread and persistent in our environments. Once persons are exposed to these metals, they are adept at entering cells and reaching the brain. Lead and cadmium are associated with numerous health outcomes even at low levels of exposure. Although manganese is an essential metal, deficiency or environmental exposure or high levels of the metal can be toxic. In cell and animal model systems, lead, cadmium, and manganese are well documented neurotoxicants that contribute to canonical Alzheimer's disease pathologies. Adult human epidemiologic studies have consistently shown lead, cadmium, and manganese are associated with impaired cognitive function and cognitive decline. No longitudinal human epidemiology study has assessed lead or manganese exposure on Alzheimer's disease specifically though two studies have reported a link between cadmium and Alzheimer's disease mortality. More longitudinal epidemiologic studies with high-quality time course exposure data and incident cases of Alzheimer's disease and related dementias are warranted to confirm and estimate the proportion of risk attributable to these exposures. Given the widespread and global exposure to lead, cadmium, and manganese, even small increases in the risks of Alzheimer's disease and related dementias would have a major population impact on the burden on disease. This article reviews the experimental and epidemiologic literature of the associations between lead, cadmium, and manganese on Alzheimer's disease and related dementias and makes recommendations of critical areas of future investment.
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Affiliation(s)
- Kelly M. Bakulski
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Young Ah Seo
- Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Ruby C. Hickman
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Daniel Brandt
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Harita S. Vadari
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Howard Hu
- School of Public Health, University of Washington, Seattle, WA, USA
| | - Sung KyunPark
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA
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17
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Cory-Slechta DA, Sobolewski M, Marvin E, Conrad K, Merrill A, Anderson T, Jackson BP, Oberdorster G. The Impact of Inhaled Ambient Ultrafine Particulate Matter on Developing Brain: Potential Importance of Elemental Contaminants. Toxicol Pathol 2019; 47:976-992. [PMID: 31610749 DOI: 10.1177/0192623319878400] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Epidemiological studies report associations between air pollution (AP) exposures and several neurodevelopmental disorders including autism, attention deficit disorder, and cognitive delays. Our studies in mice of postnatal (human third trimester brain equivalent) exposures to concentrated ambient ultrafine particles (CAPs) provide biological plausibility for these associations, producing numerous neuropathological and behavioral features of these disorders, including male-biased vulnerability. These findings raise questions about the specific components of AP that underlie its neurotoxicity, which our studies suggest could involve trace elements as candidate neurotoxicants. X-ray fluorescence analyses of CAP chamber filters confirm contamination of AP exposures by multiple elements, including iron (Fe) and sulfur (S). Correspondingly, laser ablation inductively coupled plasma mass spectrometry of brains of male mice indicates marked postexposure elevations of Fe and S and other elements. Elevations of brain Fe and S in particular are consistent with potential ferroptotic, oxidative stress, and altered antioxidant capacity-based mechanisms of CAPs-induced neurotoxicity, supported by observations of increased serum oxidized glutathione and increased neuronal cell death in nucleus accumbens with no corresponding significant increase in caspase-3, in male brains following postnatal CAP exposures. Understanding the role of trace element contaminants of particulate matter AP as a source of neurotoxicity is critical for public health protection.
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Affiliation(s)
| | - Marissa Sobolewski
- Department of Environmental Medicine, University of Rochester Medical Center, NY, USA
| | - Elena Marvin
- Department of Environmental Medicine, University of Rochester Medical Center, NY, USA
| | - Katherine Conrad
- Department of Environmental Medicine, University of Rochester Medical Center, NY, USA
| | - Alyssa Merrill
- Department of Environmental Medicine, University of Rochester Medical Center, NY, USA
| | - Tim Anderson
- Department of Environmental Medicine, University of Rochester Medical Center, NY, USA
| | - Brian P Jackson
- Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
| | - Gunter Oberdorster
- Department of Environmental Medicine, University of Rochester Medical Center, NY, USA
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18
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Johnsen KB, Burkhart A, Thomsen LB, Andresen TL, Moos T. Targeting the transferrin receptor for brain drug delivery. Prog Neurobiol 2019; 181:101665. [DOI: 10.1016/j.pneurobio.2019.101665] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/10/2019] [Accepted: 07/18/2019] [Indexed: 02/07/2023]
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19
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Yoon M, Ring C, Van Landingham CB, Suh M, Song G, Antonijevic T, Gentry PR, Taylor MD, Keene AM, Andersen ME, Clewell HJ. Assessing children's exposure to manganese in drinking water using a PBPK model. Toxicol Appl Pharmacol 2019; 380:114695. [PMID: 31394159 DOI: 10.1016/j.taap.2019.114695] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/20/2019] [Accepted: 07/30/2019] [Indexed: 12/27/2022]
Abstract
A previously published human PBPK model for manganese (Mn) in infants and children has been updated with Mn in drinking water as an additional exposure source. Built upon the ability to capture differences in Mn source-specific regulation of intestinal uptake in nursing infants who are breast-fed and formula-fed, the updated model now describes the bioavailability of Mn from drinking water in children of ages 0-18. The age-related features, including the recommended age-specific Mn dietary intake, age-specific water consumption rates, and age-specific homeostasis of Mn, are based on the available human data and knowledge of the biology of essential-metal homeostasis. Model simulations suggest that the impact of adding drinking-water exposure to daily Mn exposure via dietary intake and ambient air inhalation in children is not greater than the impacts in adults, even at a drinking-water concentration that is 2 times higher than the USEPA's lifetime health advisory value. This conclusion was also valid for formula-fed infants who are considered at the highest potential exposure to Mn from drinking water compared to all other age groups. Our multi-route, multi-source Mn PBPK model for infants and children provides insights about the potential for Mn-related health effects on growing children and will thereby improve the level of confidence in properly interpreting Mn exposure-health effects relationships in children in human epidemiological studies.
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Affiliation(s)
- M Yoon
- ToxStrategies, Inc., RTP, NC, USA.
| | - C Ring
- ToxStrategies, Inc., Austin, TX, USA
| | | | - M Suh
- ToxStrategies, Inc., Orange County, CA, USA
| | - G Song
- ToxStrategies, Inc., Orange County, CA, USA
| | | | | | | | - A M Keene
- Afton Chemical Corporation, Richmond, VA, USA
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20
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Qian ZM, Ke Y. Brain iron transport. Biol Rev Camb Philos Soc 2019; 94:1672-1684. [PMID: 31190441 DOI: 10.1111/brv.12521] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 04/22/2019] [Accepted: 04/24/2019] [Indexed: 12/19/2022]
Abstract
Brain iron is a crucial participant and regulator of normal physiological activity. However, excess iron is involved in the formation of free radicals, and has been associated with oxidative damage to neuronal and other brain cells. Abnormally high brain iron levels have been observed in various neurodegenerative diseases, including neurodegeneration with brain iron accumulation, Alzheimer's disease, Parkinson's disease and Huntington's disease. However, the key question of why iron levels increase in the relevant regions of the brain remains to be answered. A full understanding of the homeostatic mechanisms involved in brain iron transport and metabolism is therefore critical not only for elucidating the pathophysiological mechanisms responsible for excess iron accumulation in the brain but also for developing pharmacological interventions to disrupt the chain of pathological events occurring in these neurodegenerative diseases. Numerous studies have been conducted, but to date no effort to synthesize these studies and ideas into a systematic and coherent summary has been made, especially concerning iron transport across the luminal (apical) membrane of the capillary endothelium and the membranes of different brain cell types. Herein, we review key findings on brain iron transport, highlighting the mechanisms involved in iron transport across the luminal (apical) as well as the abluminal (basal) membrane of the blood-brain barrier, the blood-cerebrospinal fluid barrier, and iron uptake and release in neurons, oligodendrocytes, astrocytes and microglia within the brain. We offer suggestions for addressing the many important gaps in our understanding of this important topic, and provide new insights into the potential causes of abnormally increased iron levels in regions of the brain in neurodegenerative disorders.
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Affiliation(s)
- Zhong-Ming Qian
- Institute of Translational & Precision Medicine, Nantong University, Nantong, 226019, China.,Laboratory of Neuropharmacology, School of Pharmacy, & National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, 201203, China
| | - Ya Ke
- School of Biomedical Sciences and Gerald Choa Neuroscience Centre, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
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21
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Armitage AE, Moretti D. The Importance of Iron Status for Young Children in Low- and Middle-Income Countries: A Narrative Review. Pharmaceuticals (Basel) 2019; 12:E59. [PMID: 30995720 PMCID: PMC6631790 DOI: 10.3390/ph12020059] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 04/09/2019] [Accepted: 04/12/2019] [Indexed: 12/21/2022] Open
Abstract
Early childhood is characterised by high physiological iron demand to support processes including blood volume expansion, brain development and tissue growth. Iron is also required for other essential functions including the generation of effective immune responses. Adequate iron status is therefore a prerequisite for optimal child development, yet nutritional iron deficiency and inflammation-related iron restriction are widespread amongst young children in low- and middle-income countries (LMICs), meaning iron demands are frequently not met. Consequently, therapeutic iron interventions are commonly recommended. However, iron also influences infection pathogenesis: iron deficiency reduces the risk of malaria, while therapeutic iron may increase susceptibility to malaria, respiratory and gastrointestinal infections, besides reshaping the intestinal microbiome. This means caution should be employed in administering iron interventions to young children in LMIC settings with high infection burdens. In this narrative review, we first examine demand and supply of iron during early childhood, in relation to the molecular understanding of systemic iron control. We then evaluate the importance of iron for distinct aspects of physiology and development, particularly focusing on young LMIC children. We finally discuss the implications and potential for interventions aimed at improving iron status whilst minimising infection-related risks in such settings. Optimal iron intervention strategies will likely need to be individually or setting-specifically adapted according to iron deficiency, inflammation status and infection risk, while maximising iron bioavailability and considering the trade-offs between benefits and risks for different aspects of physiology. The effectiveness of alternative approaches not centred around nutritional iron interventions for children should also be thoroughly evaluated: these include direct targeting of common causes of infection/inflammation, and maternal iron administration during pregnancy.
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Affiliation(s)
- Andrew E Armitage
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK.
| | - Diego Moretti
- Laboratory of Human Nutrition, Institute of Food Nutrition and Health, Department of Health Sciences and Technology, ETH Zürich, CH-8092 Zürich, Switzerland.
- Nutrition Group, Health Department, Swiss Distance University of Applied Sciences, CH-8105 Regensdorf, Switzerland.
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22
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Abstract
With the development of research, more and more evidences suggested that mutations in the genes associated with brain iron metabolism induced diseases in the brain. Brain iron metabolism disorders might be one cause of neurodegenerative diseases. This review mainly summarizes the normal process of iron entry into the brain across the blood-brain barrier, and the distribution and transportation of iron among neurons and glial cells, as well as the underlying regulation mechanisms. To understand the mechanisms of iron metabolism in the brain will provide theoretical basis to prevent and cure brain diseases related to iron metabolism disorders.
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Affiliation(s)
- Peng Yu
- Laboratory of Molecular Iron Metabolism, Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, 20, Nanerhuan Eastern Road, Shijiazhuang, Hebei Province, 050024, China.
| | - Yan-Zhong Chang
- Laboratory of Molecular Iron Metabolism, Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, 20, Nanerhuan Eastern Road, Shijiazhuang, Hebei Province, 050024, China.
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23
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Wade QW, Chiou B, Connor JR. Iron uptake at the blood-brain barrier is influenced by sex and genotype. PHARMACOLOGY OF RESTLESS LEGS SYNDROME (RLS) 2019; 84:123-145. [DOI: 10.1016/bs.apha.2019.02.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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24
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Nnah IC, Wessling-Resnick M. Brain Iron Homeostasis: A Focus on Microglial Iron. Pharmaceuticals (Basel) 2018; 11:ph11040129. [PMID: 30477086 PMCID: PMC6316365 DOI: 10.3390/ph11040129] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/16/2018] [Accepted: 11/19/2018] [Indexed: 12/14/2022] Open
Abstract
Iron is an essential trace element required for important brain functions including oxidative metabolism, synaptic plasticity, myelination, and the synthesis of neurotransmitters. Disruptions in brain iron homeostasis underlie many neurodegenerative diseases. Increasing evidence suggests that accumulation of brain iron and chronic neuroinflammation, characterized by microglia activation and secretion of proinflammatory cytokines, are hallmarks of neurodegenerative disorders including Alzheimer’ s disease. While substantial efforts have led to an increased understanding of iron metabolism and the role of microglial cells in neuroinflammation, important questions still remain unanswered. Whether or not increased brain iron augments the inflammatory responses of microglial cells, including the molecular cues that guide such responses, is still unclear. How these brain macrophages accumulate, store, and utilize intracellular iron to carry out their various functions under normal and disease conditions is incompletely understood. Here, we describe the known and emerging mechanisms involved in microglial cell iron transport and metabolism as well as inflammatory responses in the brain, with a focus on AD.
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Affiliation(s)
- Israel C Nnah
- Department of Genetics and Complex Diseases, Harvard TH Chan School of Public Health, Boston, MA 02115, USA.
| | - Marianne Wessling-Resnick
- Department of Genetics and Complex Diseases, Harvard TH Chan School of Public Health, Boston, MA 02115, USA.
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25
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Lynch S, Pfeiffer CM, Georgieff MK, Brittenham G, Fairweather-Tait S, Hurrell RF, McArdle HJ, Raiten DJ. Biomarkers of Nutrition for Development (BOND)-Iron Review. J Nutr 2018; 148:1001S-1067S. [PMID: 29878148 PMCID: PMC6297556 DOI: 10.1093/jn/nxx036] [Citation(s) in RCA: 159] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/27/2017] [Accepted: 11/07/2017] [Indexed: 12/20/2022] Open
Abstract
This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health.The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation.
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Affiliation(s)
| | - Christine M Pfeiffer
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA
| | - Michael K Georgieff
- Division of Neonatology, Department of Pediatrics, University of Minnesota School of Medicine, Minneapolis, MN
| | - Gary Brittenham
- Division of Pediatric Hematology, Oncology and Stem Cell Transplant, Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, NY
| | - Susan Fairweather-Tait
- Department of Nutrition, Norwich Medical School, Norwich Research Park, University of East Anglia, Norwich NR4 7JT, UK
| | - Richard F Hurrell
- Institute of Food, Nutrition and Health, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Harry J McArdle
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen AB21 9SB, UK
| | - Daniel J Raiten
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
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Approaches for Reducing the Risk of Early-Life Iron Deficiency-Induced Brain Dysfunction in Children. Nutrients 2018; 10:nu10020227. [PMID: 29462970 PMCID: PMC5852803 DOI: 10.3390/nu10020227] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/12/2018] [Accepted: 02/14/2018] [Indexed: 12/23/2022] Open
Abstract
Iron deficiency is the most common micronutrient deficiency in the world. Women of reproductive age and young children are particularly vulnerable. Iron deficiency in late prenatal and early postnatal periods can lead to long-term neurobehavioral deficits, despite iron treatment. This may occur because screening and treatment of iron deficiency in children is currently focused on detection of anemia and not neurodevelopment. Anemia is the end-stage state of iron deficiency. The brain becomes iron deficient before the onset of anemia due to prioritization of the available iron to the red blood cells (RBCs) over other organs. Brain iron deficiency, independent of anemia, is responsible for the adverse neurological effects. Early diagnosis and treatment of impending brain dysfunction in the pre-anemic stage is necessary to prevent neurological deficits. The currently available hematological indices are not sensitive biomarkers of brain iron deficiency and dysfunction. Studies in non-human primate models suggest that serum proteomic and metabolomic analyses may be superior for this purpose. Maternal iron supplementation, delayed clamping or milking of the umbilical cord, and early iron supplementation improve the iron status of at-risk infants. Whether these strategies prevent iron deficiency-induced brain dysfunction has yet to be determined. The potential for oxidant stress, altered gastrointestinal microbiome and other adverse effects associated with iron supplementation cautions against indiscriminate iron supplementation of children in malaria-endemic regions and iron-sufficient populations.
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Healy S, McMahon JM, FitzGerald U. Modelling iron mismanagement in neurodegenerative disease in vitro: paradigms, pitfalls, possibilities & practical considerations. Prog Neurobiol 2017; 158:1-14. [DOI: 10.1016/j.pneurobio.2017.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 07/27/2017] [Accepted: 08/23/2017] [Indexed: 01/26/2023]
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Gao G, You LH, Chang YZ. Iron Metabolism in Parkinson’s Disease. OXIDATIVE STRESS AND REDOX SIGNALLING IN PARKINSON’S DISEASE 2017. [DOI: 10.1039/9781782622888-00255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In the central nervous system, iron is involved in many biologically important processes such as oxygen transport and storage, electron transport, energy metabolism, and antioxidant and DNA synthesis. Parkinson’s disease (PD) is a common neurodegenerative disease characterized by loss of dopaminergic neurons in the substantia nigra. Extensive research has reported that iron is heavily accumulated in the dopaminergic neurons in substantia nigra (SN) of PD patients. Changes in the expression of key iron transporters have also been observed in PD patients. Excessive iron accumulation can induce neuronal damage through reactive oxygen species production, which can cause oxidative stress increased membrane lipid peroxidation, DNA damage and protein oxidation and misfolding. This chapter provides a review about brain iron metabolism in PD, the role of iron transporters expression and function on brain iron homeostasis and distribution of intracellular iron. This knowledge will be of benefit to novel therapeutic targets for PD.
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Affiliation(s)
- Guofen Gao
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang Hebei Province 050024 China
| | - Lin-Hao You
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang Hebei Province 050024 China
| | - Yan-Zhong Chang
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang Hebei Province 050024 China
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Bastian TW, Duck KA, Michalopoulos GC, Chen MJ, Liu ZJ, Connor JR, Lanier LM, Sola-Visner MC, Georgieff MK. Eltrombopag, a thrombopoietin mimetic, crosses the blood-brain barrier and impairs iron-dependent hippocampal neuron dendrite development. J Thromb Haemost 2017; 15:565-574. [PMID: 28005311 PMCID: PMC5334144 DOI: 10.1111/jth.13602] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Indexed: 11/29/2022]
Abstract
Essentials Potential neurodevelopmental side effects of thrombopoietin mimetics need to be considered. The effects of eltrombopag (ELT) on neuronal iron status and dendrite development were assessed. ELT crosses the blood-brain barrier and causes iron deficiency in developing neurons. ELT blunts dendrite maturation, indicating a need for more safety studies before neonatal use. SUMMARY Background Thrombocytopenia is common in sick neonates. Thrombopoietin mimetics (e.g. eltrombopag [ELT]) might provide an alternative therapy for selected neonates with severe and prolonged thrombocytopenia, and for infants and young children with different varieties of thrombocytopenia. However, ELT chelates intracellular iron, which may adversely affect developing organs with high metabolic requirements. Iron deficiency (ID) is particularly deleterious during brain development, impairing neuronal myelination, dopamine signaling and dendritic maturation and ultimately impairing long-term neurological function (e.g. hippocampal-dependent learning and memory). Objective To determine whether ELT crosses the blood-brain barrier (BBB), causes neuronal ID and impairs hippocampal neuron dendrite maturation. Methods ELT transport across the BBB was assessed using primary bovine brain microvascular endothelial cells. Embryonic mouse primary hippocampal neuron cultures were treated with ELT or deferoxamine (DFO, an iron chelator) from 7 days in vitro (DIV) through 14 DIV and assessed for gene expression and neuronal dendrite complexity. Results ELT crossed the BBB in a time-dependent manner. 2 and 6 μm ELT increased Tfr1 and Slc11a2 (iron-responsive genes involved in neuronal iron uptake) mRNA levels, indicating neuronal ID. 6 μm ELT, but not 2 μm ELT, decreased BdnfVI, Camk2a and Vamp1 mRNA levels, suggesting impaired neuronal development and synaptic function. Dendrite branch number and length were reduced in 6 μm ELT-treated neurons, resulting in blunted dendritic arbor complexity that was similar to DFO-treated neurons. Conclusions Eltrombopag treatment during development may impair neuronal structure as a result of neuronal ID. Preclinical in vivo studies are warranted to assess ELT safety during periods of rapid brain development.
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Affiliation(s)
- Thomas W. Bastian
- Department of Pediatrics, School of Medicine, University of Minnesota, Minneapolis, MN
- Department of Neuroscience, University of Minnesota, Minneapolis, MN
- Center for Neurobehavioral Development, School of Medicine, University of Minnesota, Minneapolis, MN
| | - Kari A. Duck
- Department of Neurosurgery, The Pennsylvania State University, Hershey, PA
| | | | - Michael J. Chen
- Department of Neurosurgery, The Pennsylvania State University, Hershey, PA
| | - Zhi-Jian Liu
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA
| | - James R. Connor
- Department of Neurosurgery, The Pennsylvania State University, Hershey, PA
| | - Lorene M. Lanier
- Department of Neuroscience, University of Minnesota, Minneapolis, MN
- Center for Neurobehavioral Development, School of Medicine, University of Minnesota, Minneapolis, MN
| | | | - Michael K. Georgieff
- Department of Pediatrics, School of Medicine, University of Minnesota, Minneapolis, MN
- Center for Neurobehavioral Development, School of Medicine, University of Minnesota, Minneapolis, MN
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Ripa R, Dolfi L, Terrigno M, Pandolfini L, Savino A, Arcucci V, Groth M, Terzibasi Tozzini E, Baumgart M, Cellerino A. MicroRNA miR-29 controls a compensatory response to limit neuronal iron accumulation during adult life and aging. BMC Biol 2017; 15:9. [PMID: 28193224 PMCID: PMC5304403 DOI: 10.1186/s12915-017-0354-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/25/2017] [Indexed: 02/07/2023] Open
Abstract
Background A widespread modulation of gene expression occurs in the aging brain, but little is known as to the upstream drivers of these changes. MicroRNAs emerged as fine regulators of gene expression in many biological contexts and they are modulated by age. MicroRNAs may therefore be part of the upstream drivers of the global gene expression modulation correlated with aging and aging-related phenotypes. Results Here, we show that microRNA-29 (miR-29) is induced during aging in short-lived turquoise killifish brain and genetic antagonism of its function induces a gene-expression signature typical of aging. Mechanicistically, we identified Ireb2 (a master gene for intracellular iron delivery that encodes for IRP2 protein), as a novel miR-29 target. MiR-29 is induced by iron loading and, in turn, it reduces IRP2 expression in vivo, therefore limiting intracellular iron delivery in neurons. Genetically modified fish with neuro-specific miR-29 deficiency exhibit increased levels of IRP2 and transferrin receptor, increased iron content, and oxidative stress. Conclusions Our results demonstrate that age-dependent miR-29 upregulation is an adaptive mechanism that counteracts the expression of some aging-related phenotypes and its anti-aging activity is primarily exerted by regulating intracellular iron homeostasis limiting excessive iron-exposure in neurons. Electronic supplementary material The online version of this article (doi:10.1186/s12915-017-0354-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Roberto Ripa
- Scuola Normale Superiore, Laboratory of Biology (Bio@SNS), c/o Istituto di Biofisica del CNR, via 17 Moruzzi 1, 56124, Pisa, Italy
| | - Luca Dolfi
- Scuola Normale Superiore, Laboratory of Biology (Bio@SNS), c/o Istituto di Biofisica del CNR, via 17 Moruzzi 1, 56124, Pisa, Italy
| | - Marco Terrigno
- Scuola Normale Superiore, Laboratory of Biology (Bio@SNS), c/o Istituto di Biofisica del CNR, via 17 Moruzzi 1, 56124, Pisa, Italy
| | - Luca Pandolfini
- Wellcome Trust/Cancer Research UK Gurdon Institute, Tennis Court Road, Cambridge, CB2 1QN, UK
| | | | - Valeria Arcucci
- Scuola Normale Superiore, Laboratory of Biology (Bio@SNS), c/o Istituto di Biofisica del CNR, via 17 Moruzzi 1, 56124, Pisa, Italy
| | - Marco Groth
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstr. 11, 07745, Jena, Germany
| | - Eva Terzibasi Tozzini
- Scuola Normale Superiore, Laboratory of Biology (Bio@SNS), c/o Istituto di Biofisica del CNR, via 17 Moruzzi 1, 56124, Pisa, Italy
| | - Mario Baumgart
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstr. 11, 07745, Jena, Germany
| | - Alessandro Cellerino
- Scuola Normale Superiore, Laboratory of Biology (Bio@SNS), c/o Istituto di Biofisica del CNR, via 17 Moruzzi 1, 56124, Pisa, Italy. .,Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstr. 11, 07745, Jena, Germany.
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Bastian TW, von Hohenberg WC, Mickelson DJ, Lanier LM, Georgieff MK. Iron Deficiency Impairs Developing Hippocampal Neuron Gene Expression, Energy Metabolism, and Dendrite Complexity. Dev Neurosci 2016; 38:264-276. [PMID: 27669335 DOI: 10.1159/000448514] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 07/05/2016] [Indexed: 12/28/2022] Open
Abstract
Iron deficiency (ID), with and without anemia, affects an estimated 2 billion people worldwide. ID is particularly deleterious during early-life brain development, leading to long-term neurological impairments including deficits in hippocampus-mediated learning and memory. Neonatal rats with fetal/neonatal ID anemia (IDA) have shorter hippocampal CA1 apical dendrites with disorganized branching. ID-induced dendritic structural abnormalities persist into adulthood despite normalization of the iron status. However, the specific developmental effects of neuronal iron loss on hippocampal neuron dendrite growth and branching are unknown. Embryonic hippocampal neuron cultures were chronically treated with deferoxamine (DFO, an iron chelator) beginning at 3 days in vitro (DIV). Levels of mRNA for Tfr1 and Slc11a2, iron-responsive genes involved in iron uptake, were significantly elevated in DFO-treated cultures at 11DIV and 18DIV, indicating a degree of neuronal ID similar to that seen in rodent ID models. DFO treatment decreased mRNA levels for genes indexing dendritic and synaptic development (i.e. BdnfVI,Camk2a,Vamp1,Psd95,Cfl1, Pfn1,Pfn2, and Gda) and mitochondrial function (i.e. Ucp2,Pink1, and Cox6a1). At 18DIV, DFO reduced key aspects of energy metabolism including basal respiration, maximal respiration, spare respiratory capacity, ATP production, and glycolytic rate, capacity, and reserve. Sholl analysis revealed a significant decrease in distal dendritic complexity in DFO-treated neurons at both 11DIV and 18DIV. At 11DIV, the length of primary dendrites and the number and length of branches in DFO-treated neurons were reduced. By 18DIV, partial recovery of the dendritic branch number in DFO-treated neurons was counteracted by a significant reduction in the number and length of primary dendrites and the length of branches. Our findings suggest that early neuronal iron loss, at least partially driven through altered mitochondrial function and neuronal energy metabolism, is responsible for the effects of fetal/neonatal ID and IDA on hippocampal neuron dendritic and synaptic maturation. Impairments in these neurodevelopmental processes likely underlie the negative impact of early life ID and IDA on hippocampus-mediated learning and memory.
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Affiliation(s)
- Thomas W Bastian
- Department of Pediatrics and Center for Neurobehavioral Development, School of Medicine, Minneapolis, Minn., USA
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Abstract
Iron is an essential element for human development. It is a major requirement for cellular processes such as oxygen transport, energy metabolism, neurotransmitter synthesis, and myelin synthesis. Despite its crucial role in these processes, iron in the ferric form can also produce toxic reactive oxygen species. The duality of iron’s function highlights the importance of maintaining a strict balance of iron levels in the body. As a result, organisms have developed elegant mechanisms of iron uptake, transport, and storage. This review will focus on the mechanisms that have evolved at physiological barriers, such as the intestine, the placenta, and the blood–brain barrier (BBB), where iron must be transported. Much has been written about the processes for iron transport across the intestine and the placenta, but less is known about iron transport mechanisms at the BBB. In this review, we compare the established pathways at the intestine and the placenta as well as describe what is currently known about iron transport at the BBB and how brain iron uptake correlates with processes at these other physiological barriers.
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Affiliation(s)
- Kari A Duck
- Department of Neurosurgery, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - James R Connor
- Department of Neurosurgery, The Pennsylvania State University College of Medicine, Hershey, PA, USA.
- Department of Neurosurgery, Neural and Behavioral Sciences and Pediatrics, Center for Aging and Neurodegenerative Diseases, Penn State Hershey Medical Center, 500 University Drive, MC H110, C3830, Hershey, PA, 17033, USA.
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Zamora TG, Guiang SF, Georgieff MK, Widness JA. Iron is prioritized to red blood cells over the brain in phlebotomized anemic newborn lambs. Pediatr Res 2016; 79:922-8. [PMID: 26866907 PMCID: PMC4899227 DOI: 10.1038/pr.2016.20] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 12/03/2015] [Indexed: 12/17/2022]
Abstract
BACKGROUND Critically ill preterm and term neonates are at high risk for negative iron balance due to phlebotomy that occurs with frequent laboratory monitoring, and the high iron demand of rapid growth. Understanding the prioritization of iron between red blood cells (RBCs) and brain is important given iron's role in neurodevelopment. METHODS Ten neonatal twin lamb pairs (n = 20) underwent regular phlebotomy for 11 d. Lambs were randomized to receive no iron or i.v. daily iron supplementation from 1 to 5 mg/kg. Serum hemoglobin concentration and reticulocyte count were assayed, iron balance calculated, and iron content of RBCs, liver, brain, muscle, and heart measured at autopsy. RESULTS Among phlebotomized lambs: (i) liver iron concentration was directly related to net iron balance (r = 0.87; P < 0.001) and (ii) brain iron concentration was reduced as a function of net iron balance (r = 0.63) only after liver iron was depleted. In animals with negative iron balance, total RBC iron was maintained while brain iron concentration decreased as a percentage of the iron present in RBCs (r = -0.70; P < 0.01) and as a function of reticulocyte count (r = -0.63; P < 0.05). CONCLUSION Phlebotomy-induced negative iron balance limits iron availability to the developing brain.
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Affiliation(s)
- Tara G Zamora
- Children’s Hospitals and Clinics of Minnesota. St. Paul, MN, USA,Department of Pediatrics, University of Minnesota School of Medicine. Minneapolis, MN, USA,Corresponding Author Contact: Tara G Zamora, MD, 347 N Smith Ave Suite 505 St. Paul MN 55102, P: 651-220-6264 F: 651-220-7777,
| | - Sixto F Guiang
- Department of Pediatrics, University of Minnesota School of Medicine. Minneapolis, MN, USA
| | - Michael K Georgieff
- Department of Pediatrics, University of Minnesota School of Medicine. Minneapolis, MN, USA
| | - John A Widness
- Department of Pediatrics, University of Iowa School of Medicine. Iowa City, Iowa, USA
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The efficacy of early iron supplementation on postpartum depression, a randomized double-blind placebo-controlled trial. Eur J Nutr 2015; 56:901-908. [DOI: 10.1007/s00394-015-1140-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 12/15/2015] [Indexed: 10/22/2022]
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Bouabid S, Tinakoua A, Lakhdar-Ghazal N, Benazzouz A. Manganese neurotoxicity: behavioral disorders associated with dysfunctions in the basal ganglia and neurochemical transmission. J Neurochem 2015; 136:677-691. [PMID: 26608821 DOI: 10.1111/jnc.13442] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 10/24/2015] [Accepted: 11/10/2015] [Indexed: 11/30/2022]
Abstract
Manganese (Mn) is an essential element required for many physiological functions. While it is essential at physiological levels, excessive accumulation of Mn in the brain causes severe dysfunctions in the central nervous system known as manganism. Manganism is an extrapyramidal disorder characterized by motor disturbances associated with neuropsychiatric and cognitive disabilities similar to Parkinsonism. As the primary brain regions targeted by Mn are the basal ganglia, known to be involved in the pathophysiology of extrapyramidal disorders, this review will examine the impact of Mn exposure on the basal ganglia circuitry and neurotransmitters in relation to motor and non-motor disorders. The collected data from recent available studies in humans and experimental animal models provide new information about the mechanisms by which Mn affects behavior, neurotransmitters, and basal ganglia function observed in manganism. The effects of the alterations of metals on basal ganglia and neurochemical functioning are critical to develop effective modalities not only for the treatment of vulnerable populations (e.g., Mn-exposed workers) but also for understanding the etiology of neurodegenerative diseases where brain metal imbalances are involved, such as Parkinson's disease. We examine the impact of manganese (Mn) exposure on the basal ganglia circuitry and neurotransmitters in relation with motor and non-motor disorders. The collected data from available studies show that when accumulated in the globus pallidus, Mn influences the subthalamic (STN) and substantia nigra (SN) neurons, which are at the origin of changes in the thalamus and the cortex.
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Affiliation(s)
- Safa Bouabid
- University de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.,Université Mohammed V, Faculté des Sciences, Equipe Rythmes Biologiques, Neurosciences et Environnement, Rabat, Morocco
| | - Anass Tinakoua
- University de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.,Université Mohammed V, Faculté des Sciences, Equipe Rythmes Biologiques, Neurosciences et Environnement, Rabat, Morocco
| | - Nouria Lakhdar-Ghazal
- Université Mohammed V, Faculté des Sciences, Equipe Rythmes Biologiques, Neurosciences et Environnement, Rabat, Morocco
| | - Abdelhamid Benazzouz
- University de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
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Expression of Iron-Related Proteins at the Neurovascular Unit Supports Reduction and Reoxidation of Iron for Transport Through the Blood-Brain Barrier. Mol Neurobiol 2015; 53:7237-7253. [DOI: 10.1007/s12035-015-9582-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/29/2015] [Indexed: 11/25/2022]
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Sartini S, Lattanzi D, Ambrogini P, Di Palma M, Galati C, Savelli D, Polidori E, Calcabrini C, Rocchi MBL, Sestili P, Cuppini R. Maternal creatine supplementation affects the morpho-functional development of hippocampal neurons in rat offspring. Neuroscience 2015; 312:120-9. [PMID: 26592720 DOI: 10.1016/j.neuroscience.2015.11.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/05/2015] [Accepted: 11/10/2015] [Indexed: 12/28/2022]
Abstract
Creatine supplementation has been shown to protect neurons from oxidative damage due to its antioxidant and ergogenic functions. These features have led to the hypothesis of creatine supplementation use during pregnancy as prophylactic treatment to prevent CNS damage, such as hypoxic-ischemic encephalopathy. Unfortunately, very little is known on the effects of creatine supplementation during neuron differentiation, while in vitro studies revealed an influence on neuron excitability, leaving the possibility of creatine supplementation during the CNS development an open question. Using a multiple approach, we studied the hippocampal neuron morphological and functional development in neonatal rats born by dams supplemented with 1% creatine in drinking water during pregnancy. CA1 pyramidal neurons of supplemented newborn rats showed enhanced dendritic tree development, increased LTP maintenance, larger evoked-synaptic responses, and higher intrinsic excitability in comparison to controls. Moreover, a faster repolarizing phase of action potential with the appearance of a hyperpolarization were recorded in neurons of the creatine-treated group. Consistently, CA1 neurons of creatine exposed pups exhibited a higher maximum firing frequency than controls. In summary, we found that creatine supplementation during pregnancy positively affects morphological and electrophysiological development of CA1 neurons in offspring rats, increasing neuronal excitability. Altogether, these findings emphasize the need to evaluate the benefits and the safety of maternal intake of creatine in humans.
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Affiliation(s)
- S Sartini
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy.
| | - D Lattanzi
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - P Ambrogini
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - M Di Palma
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - C Galati
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - D Savelli
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - E Polidori
- University of Urbino Carlo Bo, Dept. of Biomolecular Sciences, via I Maggetti, 26, 61029 Urbino, Italy
| | - C Calcabrini
- University of Urbino Carlo Bo, Dept. of Biomolecular Sciences, via I Maggetti, 26, 61029 Urbino, Italy
| | - M B L Rocchi
- University of Urbino Carlo Bo, Dept. of Biomolecular Sciences, via I Maggetti, 26, 61029 Urbino, Italy
| | - P Sestili
- University of Urbino Carlo Bo, Dept. of Biomolecular Sciences, via I Maggetti, 26, 61029 Urbino, Italy
| | - R Cuppini
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
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Menon AV, Chang J, Kim J. Mechanisms of divalent metal toxicity in affective disorders. Toxicology 2015; 339:58-72. [PMID: 26551072 DOI: 10.1016/j.tox.2015.11.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 10/19/2015] [Accepted: 11/03/2015] [Indexed: 01/01/2023]
Abstract
Metals are required for proper brain development and play an important role in a number of neurobiological functions. The divalent metal transporter 1 (DMT1) is a major metal transporter involved in the absorption and metabolism of several essential metals like iron and manganese. However, non-essential divalent metals are also transported through this transporter. Therefore, altered expression of DMT1 can modify the absorption of toxic metals and metal-induced toxicity. An accumulating body of evidence has suggested that increased metal stores in the brain are associated with elevated oxidative stress promoted by the ability of metals to catalyze redox reactions, resulting in abnormal neurobehavioral function and the progression of neurodegenerative diseases. Metal overload has also been implicated in impaired emotional behavior, although the underlying mechanisms are not well understood with limited information. The current review focuses on psychiatric dysfunction associated with imbalanced metabolism of metals that are transported by DMT1. The investigations with respect to the toxic effects of metal overload on behavior and their underlying mechanisms of toxicity could provide several new therapeutic targets to treat metal-associated affective disorders.
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Affiliation(s)
| | - JuOae Chang
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Jonghan Kim
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA.
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Zizioli D, Tiso N, Guglielmi A, Saraceno C, Busolin G, Giuliani R, Khatri D, Monti E, Borsani G, Argenton F, Finazzi D. Knock-down of pantothenate kinase 2 severely affects the development of the nervous and vascular system in zebrafish, providing new insights into PKAN disease. Neurobiol Dis 2015; 85:35-48. [PMID: 26476142 PMCID: PMC4684146 DOI: 10.1016/j.nbd.2015.10.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 08/31/2015] [Accepted: 10/11/2015] [Indexed: 01/31/2023] Open
Abstract
Pantothenate Kinase Associated Neurodegeneration (PKAN) is an autosomal recessive disorder with mutations in the pantothenate kinase 2 gene (PANK2), encoding an essential enzyme for Coenzyme A (CoA) biosynthesis. The molecular connection between defects in this enzyme and the neurodegenerative phenotype observed in PKAN patients is still poorly understood. We exploited the zebrafish model to study the role played by the pank2 gene during embryonic development and get new insight into PKAN pathogenesis. The zebrafish orthologue of hPANK2 lies on chromosome 13, is a maternal gene expressed in all development stages and, in adult animals, is highly abundant in CNS, dorsal aorta and caudal vein. The injection of a splice-inhibiting morpholino induced a clear phenotype with perturbed brain morphology and hydrocephalus; edema was present in the heart region and caudal plexus, where hemorrhages with reduction of blood circulation velocity were detected. We characterized the CNS phenotype by studying the expression pattern of wnt1 and neurog1 neural markers and by use of the Tg(neurod:EGFP/sox10:dsRed) transgenic line. The results evidenced that downregulation of pank2 severely impairs neuronal development, particularly in the anterior part of CNS (telencephalon). Whole-mount in situ hybridization analysis of the endothelial markers cadherin-5 and fli1a, and use of Tg(fli1a:EGFP/gata1a:dsRed) transgenic line, confirmed the essential role of pank2 in the formation of the vascular system. The specificity of the morpholino-induced phenotype was proved by the restoration of a normal development in a high percentage of embryos co-injected with pank2 mRNA. Also, addition of pantethine or CoA, but not of vitamin B5, to pank2 morpholino-injected embryos rescued the phenotype with high efficiency. The zebrafish model indicates the relevance of pank2 activity and CoA homeostasis for normal neuronal development and functioning and provides evidence of an unsuspected role for this enzyme and its product in vascular development. Zebrafish pank2 gene is highly expressed in the CNS and the main vascular structures. Pank2 down-regulation severely affects the development of the forebrain. Pank2 down-regulation affects the dorsal aorta, caudal vein and inter-somitic vessels. Pantethine and Coenzyme A restore the normal development in the absence of pank2 expression.
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Affiliation(s)
- Daniela Zizioli
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy.
| | - Natascia Tiso
- Department of Biology, University of Padova, via U. Bassi 58/B, 35121 Padova, Italy
| | - Adele Guglielmi
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
| | - Claudia Saraceno
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
| | - Giorgia Busolin
- Department of Biology, University of Padova, via U. Bassi 58/B, 35121 Padova, Italy
| | - Roberta Giuliani
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
| | - Deepak Khatri
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
| | - Eugenio Monti
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
| | - Giuseppe Borsani
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
| | - Francesco Argenton
- Department of Biology, University of Padova, via U. Bassi 58/B, 35121 Padova, Italy
| | - Dario Finazzi
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy; Clinical Chemistry Laboratory, Spedali Civili Hospital, 25123 Brescia, Italy.
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40
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McCarthy RC, Kosman DJ. Mechanisms and regulation of iron trafficking across the capillary endothelial cells of the blood-brain barrier. Front Mol Neurosci 2015; 8:31. [PMID: 26236187 PMCID: PMC4500905 DOI: 10.3389/fnmol.2015.00031] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/29/2015] [Indexed: 02/06/2023] Open
Abstract
The transcellular trafficking of iron from the blood into the brain interstitium depends on iron uptake proteins in the apical membrane of brain microvascular capillary endothelial cells and efflux proteins at the basolateral, abluminal membrane. In this review, we discuss the three mechanisms by which these cells take-up iron from the blood and the sole mechanism by which they efflux this iron into the abluminal space. We then focus on the regulation of this efflux pathway by exocrine factors that are released from neighboring astrocytes. Also discussed are the cytokines secreted by capillary cells that regulate the expression of these glial cell signals. Among the interstitial factors that regulate iron efflux into the brain is the Amyloid precursor protein (APP). The role of this amyliodogenic species in brain iron metabolism is discussed. Last, we speculate on the potential relationship between iron transport at the blood-brain barrier and neurological disorders associated with iron mismanagement.
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Affiliation(s)
- Ryan C McCarthy
- Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo Buffalo, NY, USA
| | - Daniel J Kosman
- Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo Buffalo, NY, USA
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Abstract
The human brain undergoes a remarkable transformation during fetal life and the first postnatal years from a relatively undifferentiated but pluripotent organ to a highly specified and organized one. The outcome of this developmental maturation is highly dependent on a sequence of environmental exposures that can have either positive or negative influences on the ultimate plasticity of the adult brain. Many environmental exposures are beyond the control of the individual, but nutrition is not. An ever-increasing amount of research demonstrates not only that nutrition shapes the brain and affects its function during development but also that several nutrients early in life have profound and long-lasting effects on the brain. Nutrients have been shown to alter opening and closing of critical and sensitive periods of particular brain regions. This paper discusses the roles that various nutrients play in shaping the developing brain, concentrating specifically on recently explicated biological mechanisms by which particularly salient nutrients influence childhood and adult neural plasticity.
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Ji C, Kosman DJ. Molecular mechanisms of non-transferrin-bound and transferring-bound iron uptake in primary hippocampal neurons. J Neurochem 2015; 133:668-83. [PMID: 25649872 DOI: 10.1111/jnc.13040] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 01/08/2015] [Accepted: 01/14/2015] [Indexed: 12/16/2022]
Abstract
The molecular mechanisms of iron trafficking in neurons have not been elucidated. In this study, we characterized the expression and localization of ferrous iron transporters Zip8, Zip14 and divalent metal transporter 1 (DMT1), and ferrireductases Steap2 and stromal cell-derived receptor 2 in primary rat hippocampal neurons. Steap2 and Zip8 partially co-localize, indicating these two proteins may function in Fe(3+) reduction prior to Fe(2+) permeation. Zip8, DMT1, and Steap2 co-localize with the transferrin receptor/transferrin complex, suggesting they may be involved in transferrin receptor/transferrin-mediated iron assimilation. In brain interstitial fluid, transferring-bound iron (TBI) and non-transferrin-bound iron (NTBI) exist as potential iron sources. Primary hippocampal neurons exhibit significant iron uptake from TBI (Transferrin-(59) Fe(3+)) and NTBI, whether presented as (59) Fe(2+) -citrate or (59) Fe(3+) -citrate; reductase-independent (59) Fe(2+) uptake was the most efficient uptake pathway of the three. Kinetic analysis of Zn(2+) inhibition of Fe(2+) uptake indicated that DMT1 plays only a minor role in the uptake of NTBI. In contrast, localization and knockdown data indicate that Zip8 makes a major contribution. Data suggest also that cell accumulation of (59) Fe from TBI relies at least in part on an endocytosis-independent pathway. These data suggest that Zip8 and Steap2 play a major role in iron accumulation from NTBI and TBI by hippocampal neurons. Analysis of the expression and localization of known iron uptake transporters demonstrated that Zip8 makes a major contribution to iron accumulation in primary cultures of rat embryonic hippocampal neurons. These cells exhibit uptake pathways for ferrous and ferric iron (non-transferrin-bound iron, NTBI in figure) and for transferrin-bound iron; the ferrireductases Steap2 and SDR2 support the uptake of ferric iron substrates. Zip8 and Steap2 are strongly expressed in the plasma membrane of both soma and processes, implying a crucial role in iron accumulation from NTBI and transferrin-bound iron (TBI) by hippocampal neurons.
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Affiliation(s)
- Changyi Ji
- Department of Biochemistry, State University of New York, School of Medicine and Biomedical Sciences Buffalo, Buffalo, New York, USA
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Iron transport across the blood-brain barrier: development, neurovascular regulation and cerebral amyloid angiopathy. Cell Mol Life Sci 2014; 72:709-27. [PMID: 25355056 DOI: 10.1007/s00018-014-1771-4] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/10/2014] [Accepted: 10/23/2014] [Indexed: 12/14/2022]
Abstract
There are two barriers for iron entry into the brain: (1) the brain-cerebrospinal fluid (CSF) barrier and (2) the blood-brain barrier (BBB). Here, we review the literature on developmental iron accumulation by the brain, focusing on the transport of iron through the brain microvascular endothelial cells (BMVEC) of the BBB. We review the iron trafficking proteins which may be involved in the iron flux across BMVEC and discuss the plausible mechanisms of BMVEC iron uptake and efflux. We suggest a model for how BMVEC iron uptake and efflux are regulated and a mechanism by which the majority of iron is trafficked across the developing BBB under the direct guidance of neighboring astrocytes. Thus, we place brain iron uptake in the context of the neurovascular unit of the adult brain. Last, we propose that BMVEC iron is involved in the aggregation of amyloid-β peptides leading to the progression of cerebral amyloid angiopathy which often occurs prior to dementia and the onset of Alzheimer's disease.
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Guo C, Chen X, Xiong P. Baicalin suppresses iron accumulation after substantia nigra injury: relationship between iron concentration and transferrin expression. Neural Regen Res 2014; 9:630-6. [PMID: 25206866 PMCID: PMC4146239 DOI: 10.4103/1673-5374.130108] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2014] [Indexed: 01/13/2023] Open
Abstract
Previous studies have shown that baicalin prevented iron accumulation after substantia nigra injury, reduced divalent metal transporter 1 expression, and increased ferroportin 1 expression in the substantia nigra of rotenone-induced Parkinson's disease rats. In the current study, we investigated the relationship between iron accumulation and transferrin expression in C6 cells, to explore the mechanisms of the inhibitory effect of baicalin on iron accumulation observed in Parkinson's disease rats. Iron content was detected using inductively coupled plasma-atomic emission spectroscopy. Results showed that iron content decreased 41% after blocking divalent metal transporter 1 and ferroportin 1 proteins. After treatment with ferric ammonium citrate of differing concentrations (10, 50, 100, 400μg/mL) in C6 glioma cells, cell survival rate and ferroportin 1 expression were negatively correlated with ferric ammonium citrate concentration, but divalent metal transporter 1 expression positively correlated with ferric ammonium citrate concentration. Baicalin or deferoxamine reduced divalent metal transporter 1 expression, but increased ferroportin 1 expression in the 100μg/mL ferric ammonium citrate-loaded C6 cells. These results indicate that baicalin down-regulated iron concentration, which positively regulated divalent metal transporter 1 expression and negatively regulated ferroportin 1 expression, and decreased iron accumulation in the substantia nigra.
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Affiliation(s)
- Chunyan Guo
- Traditional Chinese Medicine School, Capital Medical University, Beijing, China
| | - Xin Chen
- Traditional Chinese Medicine School, Capital Medical University, Beijing, China
| | - Pei Xiong
- Traditional Chinese Medicine School, Capital Medical University, Beijing, China
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45
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Perinatal manganese exposure and hydroxyl radical formation in rat brain. Neurotox Res 2014; 27:1-14. [PMID: 25323423 PMCID: PMC4286139 DOI: 10.1007/s12640-014-9474-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 04/22/2014] [Accepted: 04/22/2014] [Indexed: 11/13/2022]
Abstract
The present study was designed to investigate the role of pre- and postnatal manganese (Mn) exposure on hydroxyl radical (HO•) formation in the brains of dopamine (DA) partially denervated rats (Parkinsonian rats). Wistar rats were given tap water containing 10,000 ppm manganese chloride during the duration of pregnancy and until the time of weaning. Control rat dams consumed tap water without added Mn. Three days after birth, rats of both groups were treated with 6-hydroxydopamine at one of three doses (15, 30, or 67 µg, intraventricular on each side), or saline vehicle. We found that Mn content in the brain, kidney, liver, and bone was significantly elevated in dams exposed to Mn during pregnancy. In neonates, the major organs that accumulated Mn were the femoral bone and liver. However, Mn was not elevated in tissues in adulthood. To determine the possible effect on generation of the reactive species, HO• in Mn-induced neurotoxicity, we analyzed the contents of 2.3- and 2.5-dihydroxybenzoic acid (spin trap products of salicylate; HO• being an index of in vivo HO• generation), as well as antioxidant enzyme activities of superoxide dismutase (SOD) isoenzymes and glutathione S-transferase (GST). 6-OHDA-depletion of DA produced enhanced HO• formation in the brain tissue of newborn and adulthood rats that had been exposed to Mn, and the latter effect did not depend on the extent of DA denervation. Additionally, the extraneuronal, microdialysate, content of HO• in neostriatum was likewise elevated in 6-OHDA-lesioned rats. Interestingly, there was no difference in extraneuronal HO• formation in the neostriatum of Mn-exposed versus control rats. In summary, findings in this study indicate that Mn crosses the placenta but in contrast to other heavy metals, Mn is not deposited long term in tissues. Also, damage to the dopaminergic system acts as a “trigger mechanism,” initiating a cascade of adverse events leading to a protracted increase in HO• generation, and the effects of Mn and 6-OHDA are compounded. Moreover, HO• generation parallels the suppression of SOD isoenzymes and GST in the brains of rats lesioned with 6-OHDA and/or intoxicated with Mn—the most prominent impairments being in frontal cortex, striatum, and brain stem. In conclusion, ontogenetic Mn exposure, resulting in reactive oxygen species, HO• formation, represents a risk factor for dopaminergic neurotoxicity and development of neurodegenerative disorders.
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46
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Gao G, Chang YZ. Mitochondrial ferritin in the regulation of brain iron homeostasis and neurodegenerative diseases. Front Pharmacol 2014; 5:19. [PMID: 24596558 PMCID: PMC3925988 DOI: 10.3389/fphar.2014.00019] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 01/30/2014] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial ferritin (FtMt) is a novel iron-storage protein in mitochondria. Evidences have shown that FtMt is structurally and functionally similar to the cytosolic H-chain ferritin. It protects mitochondria from iron-induced oxidative damage presumably through sequestration of potentially harmful excess free iron. It also participates in the regulation of iron distribution between cytosol and mitochondrial contents. Unlike the ubiquitously expressed H-ferritin, FtMt is mainly expressed in testis and brain, which suggests its tissue-related roles. FtMt is involved in pathogenesis of neurodegenerative diseases, as its increased expression has been observed in Alzheimer’s disease, restless legs syndrome and Friedreich’s ataxia. Studies from our laboratory showed that in Alzheimer’s disease, FtMt overexpression attenuated the β-amyloid induced neurotoxicity, which on the other hand increased significantly when FtMt expression was knocked down. It is also found that, by maintaining mitochondrial iron homeostasis, FtMt could prevent 6-hydroxydopamine induced dopaminergic cell damage in Parkinson’s disease. These recent findings on FtMt regarding its functions in regulation of brain iron homeostasis and its protective role in pathogenesis of neurodegenerative diseases are summarized and reviewed.
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Affiliation(s)
- Guofen Gao
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
| | - Yan-Zhong Chang
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University Shijiazhuang, China
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47
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Callahan LSN, Thibert KA, Wobken JD, Georgieff MK. Early-life iron deficiency anemia alters the development and long-term expression of parvalbumin and perineuronal nets in the rat hippocampus. Dev Neurosci 2013; 35:427-36. [PMID: 24080972 DOI: 10.1159/000354178] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 07/04/2013] [Indexed: 01/07/2023] Open
Abstract
Early-life iron deficiency anemia (IDA) alters the expression of critical genes involved in neuronal dendritic structural plasticity of the hippocampus, thus contributing to delayed maturation of electrophysiology, and learning and memory behavior in rats. Structural maturity in multiple cortical regions is characterized by the appearance of parvalbumin-positive (PV(+)) GABAergic interneurons and perineuronal nets (PNNs). Appearance of PV(+) interneurons and PNNs can serve as cellular markers for the beginning and end of a critical developmental period, respectively. During this period, the system progresses from an immature yet highly plastic condition, to a more mature and efficient state that is however less flexible and may exhibit poorer potential for recovery from injury. To test if fetal-neonatal IDA alters parvalbumin (PV) mRNA expression, protein levels, and the number of PV(+) interneurons and PNNs in the male rat hippocampus, pregnant dams were given an iron-deficient (ID) diet (3 mg iron/kg chow) from gestational day 2 to postnatal day (P) 7 and then placed on an iron-sufficient (IS) diet (198 mg/kg) for the remainder of the experiment. On this regimen, formerly ID animals become fully iron-replete by P56. Minimal levels of PV (mRNA and protein), PV(+) interneurons, and PNNs were found in IS and ID P7 rats. By P15, and continuing through P30 and P65, ID rats had reduced PV mRNA expression and protein levels compared to IS controls. While there were no differences in the number of PV(+) neurons at either P30 or P65, the percentage of PV(+) cells surrounded by PNNs was slightly greater in ID rats as compared to IS controls. The lower levels of these acknowledged critical period biomarkers in the ID group are consistent with studies that demonstrate later maturation of the acutely ID hippocampus and lower plasticity in the adult formerly ID hippocampus. The findings provide additional potential cellular bases for previously described electrophysiologic and behavioral abnormalities found during and following early-life IDA.
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Affiliation(s)
- Liam S N Callahan
- Department of Pediatrics, Center for Neurobehavioral Development, University of Minnesota, Minneapolis, Minn., USA
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48
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Radlowski EC, Johnson RW. Perinatal iron deficiency and neurocognitive development. Front Hum Neurosci 2013; 7:585. [PMID: 24065908 PMCID: PMC3779843 DOI: 10.3389/fnhum.2013.00585] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 08/30/2013] [Indexed: 12/20/2022] Open
Abstract
Iron deficiency is the most common form of nutrient deficiency worldwide. It is highly prevalent due to the limited availability of high quality food in developing countries and poor dietary habits in industrialized countries. According to the World Health Organization, it affects nearly 2 billion people and up to 50% of women who are pregnant. Maternal anemia during pregnancy is especially burdensome to healthy neurodevelopment in the fetus because iron is needed for proper neurogenesis, development, and myelination. Maternal anemia also increases the risk of low birth weight, either due to premature birth or fetal growth restriction, which is associated with delayed neurocognitive development and even psychiatric illness. As rapid neurodevelopment continues after birth infants that received sufficient iron in utero, but that receive a low iron diet after 6 months of age, also show deficits in neurocognitive development, including impairments in learning and memory. Unfortunately, the neurocognitive complications of iron deficiency during critical pre- and postnatal periods of brain development are difficult to remedy, persisting into adulthood. Thus, preventing iron deficiency in the pre- and postnatal periods is critical as is devising new means to recapture cognitive function in individuals who experienced early iron deficiency. This review will discuss the prevalence of pre- and postnatal iron deficiency, the mechanism, and effects of iron deficiency on brain and cognitive development.
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Affiliation(s)
- Emily C Radlowski
- 1Department of Animal Sciences, University of Illinois Urbana, IL, USA ; 2Division of Nutritional Sciences, University of Illinois Urbana, IL, USA
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49
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Fretham SJB, Carlson ES, Georgieff MK. Neuronal-specific iron deficiency dysregulates mammalian target of rapamycin signaling during hippocampal development in nonanemic genetic mouse models. J Nutr 2013; 143:260-6. [PMID: 23303869 PMCID: PMC3713018 DOI: 10.3945/jn.112.168617] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Iron deficiency (ID) is the most common nutrient deficiency worldwide, disproportionally affecting infants, children, and women of childbearing age. Although ID commonly occurs with anemia (IDA), nonanemic ID is 3 times more common than IDA in toddlers and also occurs in infants following gestational complications. Both conditions negatively affect motor, socio-emotional, and cognitive behaviors, suggesting that iron, apart from anemia, has a critical role in neurodevelopment. Here, the specific role of iron in regulation of mammalian target of rapamycin (mTOR) signaling (a kinase pathway that integrates metabolic supply and demand to regulate cell growth and morphology) was examined using 2 hippocampal, pyramidal cell-specific, nonanemic, genetic mouse models of ID: a CAMKIIα cre-loxP permanent knockout of divalent metal transporter-1 (DMT-1 CKO) and a CAMKIIα-tTA-driven reversible, overexpression of nonfunctional, dominant negative transferrin receptor-1 (DN TfR-1). In both models, mTOR activity, assessed by phosphorylation levels of key proteins, was upregulated during development by ID [S6K(Thr389) phosphorylation increased 87 and 57% in the DMT-1 CKO and DN TfR-1 models, respectively; P < 0.05]. This effect was shown to be iron-dependent, because iron repletion at postnatal d 21 normalized mTOR activity in the reversible DN TfR-1 model (62% reduction compared with unrepleted mice; P < 0.05). In the permanent DMT-1 CKO model, suppression of ID-induced mTOR hyperactivity by rapamycin administered during the sensitive period for iron improved Morris water maze performance despite ongoing ID (DMT-1 wild-type and DMT-1 CKO mice reached criterion in 3 d compared with 4 d necessary for vehicle-treated DMT-1 CKO mice; P < 0.05). Together, these findings implicate mTOR dysregulation as a cellular mechanism underlying the acute and persistent neurodevelopmental deficits that accompany early-life ID.
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Affiliation(s)
- Stephanie J. B. Fretham
- Department of Pediatrics,Center for Neurobehavioral Development,Graduate Program in Neuroscience
| | - Erik S. Carlson
- Department of Pediatrics,Center for Neurobehavioral Development,Graduate Program in Neuroscience,Medical Scientist Training Program, and
| | - Michael K. Georgieff
- Department of Pediatrics,Center for Neurobehavioral Development,Graduate Program in Neuroscience,Developmental Biology Center, University of Minnesota School of Medicine, Minneapolis, MN,To whom correspondence should be addressed. E-mail:
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50
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Monnot AD, Zheng G, Zheng W. Mechanism of copper transport at the blood-cerebrospinal fluid barrier: influence of iron deficiency in an in vitro model. Exp Biol Med (Maywood) 2012; 237:327-33. [PMID: 22442359 DOI: 10.1258/ebm.2011.011170] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Copper (Cu) is an essential trace element that requires tight homeostatic regulation to ensure appropriate supply while not causing cytotoxicity due to its strong redox potential. Our previous in vivo study has shown that iron deficiency (FeD) increases Cu levels in brain tissues, particularly in the choroid plexus, where the blood-cerebrospinal fluid (CSF) barrier resides. This study was designed to elucidate the mechanism by which FeD results in excess Cu accumulation at the blood-CSF barrier. The effect of FeD on cellular Cu retention and transporters Cu transporter-1 (Ctr1), divalent metal transporter 1 (DMT1), antioxidant protein-1 (ATOX1) and ATP7A was examined in choroidal epithelial Z310 cells. The results revealed that deferoximine treatment (FeD) resulted in 70% increase in cellular Cu retention (P < 0.05). A significant increase in the mRNA levels of DMT1, but not Ctr1, was also observed after FeD treatment, suggesting a critical role of DMT1 in cellular Cu regulation during FeD. Knocking down Ctr1 or DMT1 resulted in significantly lower Cu uptake by Z310 cells, whereas the knocking down of ATOX1 or ATP7A led to substantial increases of cellular retention of Cu. Taken together, these results suggest that Ctr1, DMT1, ATOX1 and ATP7A contribute to Cu transport at the blood-CSF barrier, and that the accumulation of intracellular Cu found in the Z310 cells during FeD appears to be mediated, at least in part, via the upregulation of DMT1 after FeD treatment.
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Affiliation(s)
- Andrew D Monnot
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, CIVL1169, West Lafayette, IN 47907, USA
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