Long-Term Brain and Behavioral Consequences of Early-Life Iron Deficiency

2016 ◽  
pp. 295-316 ◽  
Author(s):  
Bruce C. Kennedy ◽  
Diana J. Wallin ◽  
Phu V. Tran ◽  
Michael K. Georgieff
Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4527
Author(s):  
Shirelle X. Liu ◽  
Amanda K. Barks ◽  
Scott Lunos ◽  
Jonathan C. Gewirtz ◽  
Michael K. Georgieff ◽  
...  

Early-life iron deficiency (ID) causes long-term neurocognitive impairments and gene dysregulation that can be partially mitigated by prenatal choline supplementation. The long-term gene dysregulation is hypothesized to underlie cognitive dysfunction. However, mechanisms by which iron and choline mediate long-term gene dysregulation remain unknown. In the present study, using a well-established rat model of fetal-neonatal ID, we demonstrated that ID downregulated hippocampal expression of the gene encoding JmjC-ARID domain-containing protein 1B (JARID1B), an iron-dependent histone H3K4 demethylase, associated with a higher histone deacetylase 1 (HDAC1) enrichment and a lower enrichment of acetylated histone H3K9 (H3K9ac) and phosphorylated cAMP response element-binding protein (pCREB). Likewise, ID reduced transcriptional capacity of the gene encoding brain-derived neurotrophic factor (BDNF), a target of JARID1B, associated with repressive histone modifications such as lower H3K9ac and pCREB enrichments at the Bdnf promoters in the adult rat hippocampus. Prenatal choline supplementation did not prevent the ID-induced chromatin modifications at these loci but induced long-lasting repressive chromatin modifications in the iron-sufficient adult rats. Collectively, these findings demonstrated that the iron-dependent epigenetic mechanism mediated by JARID1B accounted for long-term Bdnf dysregulation by early-life ID. Choline supplementation utilized a separate mechanism to rescue the effect of ID on neural gene regulation. The negative epigenetic effects of choline supplementation in the iron-sufficient rat hippocampus necessitate additional investigations prior to its use as an adjunctive therapeutic agent.


Nutrients ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1191 ◽  
Author(s):  
Yu-Chin Lien ◽  
David E Condon ◽  
Michael K Georgieff ◽  
Rebecca A Simmons ◽  
Phu V Tran

Early-life iron deficiency results in long-term abnormalities in cognitive function and affective behavior in adulthood. In preclinical models, these effects have been associated with long-term dysregulation of key neuronal genes. While limited evidence suggests histone methylation as an epigenetic mechanism underlying gene dysregulation, the role of DNA methylation remains unknown. To determine whether DNA methylation is a potential mechanism by which early-life iron deficiency induces gene dysregulation, we performed whole genome bisulfite sequencing to identify loci with altered DNA methylation in the postnatal day (P) 15 iron-deficient (ID) rat hippocampus, a time point at which the highest level of hippocampal iron deficiency is concurrent with peak iron demand for axonal and dendritic growth. We identified 229 differentially methylated loci and they were mapped within 108 genes. Among them, 63 and 45 genes showed significantly increased and decreased DNA methylation in the P15 ID hippocampus, respectively. To establish a correlation between differentially methylated loci and gene dysregulation, the methylome data were compared to our published P15 hippocampal transcriptome. Both datasets showed alteration of similar functional networks regulating nervous system development and cell-to-cell signaling that are critical for learning and behavior. Collectively, the present findings support a role for DNA methylation in neural gene dysregulation following early-life iron deficiency.


Author(s):  
Maria Fitzgerald ◽  
Michael W. Salter

The influence of development and sex on pain perception has long been recognized but only recently has it become clear that this is due to specific differences in underlying pain neurobiology. This chapter summarizes the evidence for mechanistic differences in male and female pain biology and for functional changes in pain pathways through infancy, adolescence, and adulthood. It describes how both developmental age and sex determine peripheral nociception, spinal and brainstem processing, brain networks, and neuroimmune pathways in pain. Finally, the chapter discusses emerging evidence for interactions between sex and development and the importance of sex in the short- and long-term effects of early life pain.


Author(s):  
Stefanie Howaldt ◽  
Eugeni Domènech ◽  
Nicholas Martinez ◽  
Carsten Schmidt ◽  
Bernd Bokemeyer

Abstract Background Iron-deficiency anemia is common in inflammatory bowel disease, requiring oral or intravenous iron replacement therapy. Treatment with standard oral irons is limited by poor absorption and gastrointestinal toxicity. Ferric maltol is an oral iron designed for improved absorption and tolerability. Methods In this open-label, phase 3b trial (EudraCT 2015-002496-26 and NCT02680756), adults with nonseverely active inflammatory bowel disease and iron-deficiency anemia (hemoglobin, 8.0-11.0/12.0 g/dL [women/men]; ferritin, <30 ng/mL/<100 ng/mL with transferrin saturation <20%) were randomized to oral ferric maltol 30 mg twice daily or intravenous ferric carboxymaltose given according to each center’s standard practice. The primary endpoint was a hemoglobin responder rate (≥2 g/dL increase or normalization) at week 12, with a 20% noninferiority limit in the intent-to-treat and per-protocol populations. Results For the intent-to-treat (ferric maltol, n = 125/ferric carboxymaltose, n = 125) and per-protocol (n = 78/88) analyses, week 12 responder rates were 67% and 68%, respectively, for ferric maltol vs 84% and 85%, respectively, for ferric carboxymaltose. As the confidence intervals crossed the noninferiority margin, the primary endpoint was not met. Mean hemoglobin increases at weeks 12, 24, and 52 were 2.5 vs 3.0 g/dL, 2.9 vs 2.8 g/dL, and 2.7 vs 2.8 g/dL with ferric maltol vs ferric carboxymaltose. Treatment-emergent adverse events occurred in 59% and 36% of patients, respectively, and resulted in treatment discontinuation in 10% and 3% of patients, respectively. Conclusions Ferric maltol achieved clinically relevant increases in hemoglobin but did not show noninferiority vs ferric carboxymaltose at week 12. Both treatments had comparable long-term effectiveness for hemoglobin and ferritin over 52 weeks and were well tolerated.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A11-A12
Author(s):  
Carolyn Jones ◽  
Randall Olson ◽  
Alex Chau ◽  
Peyton Wickham ◽  
Ryan Leriche ◽  
...  

Abstract Introduction Glutamate concentrations in the cortex fluctuate with the sleep wake cycle in both rodents and humans. Altered glutamatergic signaling, as well as the early life onset of sleep disturbances have been implicated in neurodevelopmental disorders such as autism spectrum disorder. In order to study how sleep modulates glutamate activity in brain regions relevant to social behavior and development, we disrupted sleep in the socially monogamous prairie vole (Microtus ochrogaster) rodent species and quantified markers of glutamate neurotransmission within the prefrontal cortex, an area of the brain responsible for advanced cognition and complex social behaviors. Methods Male and female prairie voles were sleep disrupted using an orbital shaker to deliver automated gentle cage agitation at continuous intervals. Sleep was measured using EEG/EMG signals and paired with real time glutamate concentrations in the prefrontal cortex using an amperometric glutamate biosensor. This same method of sleep disruption was applied early in development (postnatal days 14–21) and the long term effects on brain development were quantified by examining glutamatergic synapses in adulthood. Results Consistent with previous research in rats, glutamate concentration in the prefrontal cortex increased during periods of wake in the prairie vole. Sleep disruption using the orbital shaker method resulted in brief cortical arousals and reduced time in REM sleep. When applied during development, early life sleep disruption resulted in long-term changes in both pre- and post-synaptic components of glutamatergic synapses in the prairie vole prefrontal cortex including increased density of immature spines. Conclusion In the prairie vole rodent model, sleep disruption on an orbital shaker produces a sleep, behavioral, and neurological phenotype that mirrors aspects of autism spectrum disorder including altered features of excitatory neurotransmission within the prefrontal cortex. Studies using this method of sleep disruption combined with real time biosensors for excitatory neurotransmitters will enhance our understanding of modifiable risk factors, such as sleep, that contribute to the altered development of glutamatergic synapses in the brain and their relationship to social behavior. Support (if any) NSF #1926818, VA CDA #IK2 BX002712, Portland VA Research Foundation, NIH NHLBI 5T32HL083808-10, VA Merit Review #I01BX001643


2021 ◽  
pp. 1-10
Author(s):  
Pablo E. Pergola ◽  
Diogo Belo ◽  
Paul Crawford ◽  
Moustafa Moustafa ◽  
Wenli Luo ◽  
...  

<b><i>Introduction:</i></b> Ferric citrate (FC) is indicated as an oral iron replacement for iron deficiency anemia in adult patients with chronic kidney disease (CKD) not on dialysis. The recommended starting dose is one 1-g tablet three times daily (TID). This study investigated long-term efficacy and safety of different FC dosing regimens for treating anemia in nondialysis-dependent CKD (NDD-CKD). <b><i>Methods:</i></b> In this phase 4, randomized, open-label, multicenter study, patients with anemia with NDD-CKD (estimated glomerular filtration rate, ≥20 mL/min and &#x3c;60 mL/min) were randomized 1:1 to one FC tablet (1-g equivalent to 210 mg ferric iron) TID (3 g/day) or 2 tablets twice daily (BID; 4 g/day). At week 12, dosage was increased to 2 tablets TID (6 g/day) or 3 tablets BID (6 g/day) in patients whose hemoglobin (Hb) levels increased &#x3c;0.5 g/dL or were &#x3c;10 g/dL. Primary endpoint was mean change in Hb from baseline to week 24. <b><i>Results:</i></b> Of 484 patients screened, 206 were randomized and 205 received FC. Mean (standard deviation) changes from baseline in Hb at week 24 were 0.77 (0.84) g/dL with FC TID 3 g/day and 0.70 (0.98) g/dL with FC BID 4 g/day. <b><i>Discussion/Conclusions:</i></b> FC administered BID and TID for 48 weeks was safe and effective for treating anemia in this population, supporting potentially increased dosing flexibility.


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