scholarly journals Iron Overload contributes to General Anesthesia-induced Neurotoxicity and Cognitive Deficits

2019 ◽  
Author(s):  
Jing Wu ◽  
Shuofei Yang ◽  
Yan Cao ◽  
Huihui Li ◽  
Hongting Zhao ◽  
...  

Abstract Background Increasing evidence suggests that exposure to general anesthesia (GA) could be detrimental to cognitive development in young subjects, and might also contribute to accelerated neurodegeneration in the elderly. Iron is essential for normal neuronal function and excess iron in brain is a hallmark of neuroinflammation and is implicated in several neurodegenerative diseases. However, the role of iron in GA-induced neurotoxicity and cognitive deficits has not been studied.Methods We used the primary hippocampal neurons and rodents including young rats and aged mice to examine whether GA impacts iron metabolism and whether the impact contributed to neuronal outcomes. In addition, a pharmacological suppression of iron metabolism was performed to explore the molecular mechanism underlying GAs-mediated iron overload in the brain.Results Our results demonstrated that GA, induced by intravenous ketamine or inhalational sevoflurane, disturbed iron homeostasis and caused iron overload in both in vitro hippocampal neuron culture and in vivo hippocampus. Interestingly, ketamine or sevoflurane-induced cognitive deficits, very likely, result from a novel regulated iron-dependent cell death, ferroptosis. Notably, iron chelator deferiprone attenuated the GA-induced mitochondrial dysfunctions, ferroptosis, and further cognitive deficits. Moreover, we found that GA-induced iron overload was activated by NMDAR-RASD1 signalling via DMT1 action in the brain.Conclusion We conclude that disturbed iron metabolism may be involved in the pathogenesis of GA-induced neurotoxicity and cognitive deficits. Our study provides new insights into a potential novel therapy for prevention in GA-associated neurological disorders.

2020 ◽  
Author(s):  
Jing Wu ◽  
Jian-Jun Yang ◽  
Yan Cao ◽  
Huihui Li ◽  
Hongting Zhao ◽  
...  

Abstract Background: Increasing evidence suggests that multiple or long-time exposure to general anesthesia (GA) could be detrimental to cognitive development in young subjects, and might also contribute to accelerated neurodegeneration in the elderly. Iron is essential for normal neuronal function and excess iron in brain is implicated in several neurodegenerative diseases. However, the role of iron in GA-induced neurotoxicity and cognitive deficits remains elusive. Methods: We used the primary hippocampal neurons and rodents including young rats and aged mice to examine whether GA impacted iron metabolism and whether the impact contributed to neuronal outcomes. In addition, a pharmacological suppression of iron metabolism was performed to explore the molecular mechanism underlying GAs-mediated iron overload in the brain. Results: Our results demonstrated that GA, induced by intravenous ketamine or inhalational sevoflurane, disturbed iron homeostasis and caused iron overload in both in vitro hippocampal neuron culture and in vivo hippocampus. Interestingly, ketamine or sevoflurane-induced cognitive deficits, very likely, resulted from a novel iron-dependent regulated cell death, ferroptosis. Notably, iron chelator deferiprone attenuated the GA-induced mitochondrial dysfunction, ferroptosis, and further cognitive deficits. Moreover, we found that GA-induced iron overload was activated by NMDAR-RASD1 signalling via DMT1 action in the brain. Conclusion: We conclude that disturbed iron metabolism may be involved in the pathogenesis of GA-induced neurotoxicity and cognitive deficits. Our study provides new vision for consideration in GA-associated neurological disorders.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3941-3941
Author(s):  
Rakesh Bam ◽  
Wen Ling ◽  
Sharmin Khan ◽  
Sathisha Upparahalli Venkateshaiah ◽  
Xin Li ◽  
...  

Abstract Abstract 3941 Iron overload is a significant clinical feature in multiple myeloma (MM) and has been implicated in osteoporosis. MM patients also frequently suffer from anemia presumably due to elevated hepcidin secretion and dysfunctional erythropoiesis. The aims of the study were to shed light on molecular mechanisms associated with iron overload in MM cells and study the effect of the novel iron chelator, Dp44mT, on MM cell growth, osteoclastogenesis and MM bone disease in vitro and in vivo. In our clinical global gene expression profiling (GEP) data the main iron transporter gene TFRC (transferrin receptor) was >3 folds higher (p<0.0001) in newly diagnosed MM cells (n=556) than normal plasma cells (n=25) while the iron exporter ferroportin was downregulated in MM cells by >4 folds (p<0.0001). Deregulated TFRC and ferroportin expression were more profound in the molecularly classified proliferation (PR) subtype. Osteoclasts which are known to have abundant mitochondria due to high energy consumption express excessive TFRC (>5 folds higher than highly proliferating MM cells). In primary MM cell-osteoclast cocultures (n=8) TFRC expression was upregulated in cocultured MM cells than baseline MM cells (p<0.03) while ferroportin was lower in cocultured osteoclasts than control osteoclasts (p<0.04). Our GEP, qRT-PCR and immunohistochemistry analyses revealed expression of hepcidin by osteoclasts but not MM cells. Hepcidin was not detected in conditioned media from osteoclasts cultured alone or cocultured with MM cells using ELISA, suggesting an autocrine role of hepcidin in maintaining excess iron in osteoclasts. In vitro, Dp44mT dose dependently inhibited growth of MM cell lines (n=3) at low nanomolar levels (IC50 at 3±0.8 nM, p<0.03, 48 hrs). In contrast, known chelators such as Deferoxamine and Deferasirox inhibited myeloma cell growth at 10–50 micromoles range. At 1nM Dp44mT also suppressed formation of multinucleated osteoclasts by 87% (p<0.001) and bone resorbing activity of mature osteoclasts on dentine slices by 94% (p<0.03). Dp44mT induced upregulation of BMP2 expression in osteoblast precursors and promoted osteoblast differentiation. In vivo, SCID-rab mice engrafted with luciferase-expressing U266 MM line (6 mice/group) or the Hg MM line (maintained through in vivo passaging, 10 mice/group) were subcutaneously treated with vehicle or Dp44mT (1 mg/kg/day) for 2–3 weeks. Using live-animal imaging, Dp44mT reduced growth of U266 cells by 3 folds from pretreatment levels (p<0.01) while in control group tumor burden was increased by 52 folds from pretreatment levels (p<0.002). Dp44mT also inhibited growth of Hg MM cells determined by measurement of circulating human immunoglobulins in mice sera (p<0.01). Osteoclasts numbers were lower by 36% (p<0.003) while osteoblasts numbers were higher by 59% (p<0.017) in myelomatous bones from hosts treated with Dp44mT than control vehicle. Our data suggest that interaction of myeloma cells with osteoclasts alters expression of distinct iron metabolism associated factors which elicit iron overload in both cell types, resulting in increased myeloma cell proliferation and osteoclast activity. This study also suggests that Dp44mT is an effective iron chelator with marked anti-MM activity. Disclosures: Barlogie: Celgene, Genzyme, Novartis, Millennium: Consultancy, Honoraria, Patents & Royalties. Shaughnessy:Myeloma Health, Celgene, Genzyme, Novartis: Consultancy, Employment, Equity Ownership, Honoraria, Patents & Royalties.


2021 ◽  
Author(s):  
Hyunseong Kim ◽  
Jin Young Hong ◽  
Wan-Jin Jeon ◽  
Junseon Lee ◽  
Yoon Jae Lee ◽  
...  

Abstract BackgroundLumbar spinal stenosis (LSS) is defined as the narrowing of the spinal canal, which compresses the nerves traveling through the lower back into the legs. Inflammation is the most common cause of LSS. Chronic pain induced by nerve damage results from chronic inflammation, and the inflammation response worsens with elevated iron stores. Furthermore, macrophage polarization to the M1 (inflammatory) or M2 (anti-inflammatory) type is essential for controlling host defense or repairing tissues. However, the precise function of macrophage polarization in iron release or retention in LSS pathophysiology is not well-understood. Here, we introduce melittin to modulate macrophage polarization related to iron metabolism for LSS treatment.MethodsPrimary peritoneal macrophage were cultured in 200 or 500 ng/mL of melittin and FeSO4-containing medium for 24 h. Macrophage polarization was assessed by Immunofluorescence staining to CD86 or Arg1 antibodies. In an in vivo rat model of LSS, melittin were administered at 100 and 250 µg/kg, and in vivo effects of melittin on iron deposition-induced macrophage polarization was evaluated by immunochemistry, real time-PCR, western blot, and flow-cytometry. The locomotor functions were assessed by BBB, ladder scoring, and Von Frey test for up to 3 weeks. ResultsIn vitro experiments demonstrated that macrophages can be polarized toward an M2 phenotype after melittin treatment in iron-insulted primary macrophages. Treatment with 100 and 250 μg/kg melittin in a rat LSS model increased the proportion of M2 macrophages in the damaged spinal cord. Moreover, we found that melittin attenuated iron overload-induced M1 polarization via regulating iron metabolism-related genes in LSS rats. As a result, melittin improved locomotor recovery and stimulated axonal growth following LSS.ConclusionsMelittin can promote functional recovery in LSS models by activating M2 macrophages via controlling macrophage iron metabolism, suggesting the potential applications of melittin for treating LSS.


2018 ◽  
Vol 18 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Jiaqiang Wang ◽  
Chien-shan Cheng ◽  
Yan Lu ◽  
Xiaowei Ding ◽  
Minmin Zhu ◽  
...  

Background: Propofol, a widely used intravenous anesthetic agent, is traditionally applied for sedation and general anesthesia. Explanation: Recent attention has been drawn to explore the effect and mechanisms of propofol against cancer progression in vitro and in vivo. Specifically, the proliferation-inhibiting and apoptosis-inducing properties of propofol in cancer have been studied. However, the underlying mechanisms remain unclear. Conclusion: This review focused on the findings within the past ten years and aimed to provide a general overview of propofol's malignance-modulating properties and the potential molecular mechanisms.


2013 ◽  
Vol 150 (3) ◽  
pp. 1024-1031 ◽  
Author(s):  
Mohammad Hossein Boskabady ◽  
Sakine Shahmohammadi Mehrjardi ◽  
Abadorrahim Rezaee ◽  
Houshang Rafatpanah ◽  
Sediqeh Jalali

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroaki Kanzaki ◽  
Tetsuhiro Chiba ◽  
Junjie Ao ◽  
Keisuke Koroki ◽  
Kengo Kanayama ◽  
...  

AbstractFGF19/FGFR4 autocrine signaling is one of the main targets for multi-kinase inhibitors (MKIs). However, the molecular mechanisms underlying FGF19/FGFR4 signaling in the antitumor effects to MKIs in hepatocellular carcinoma (HCC) remain unclear. In this study, the impact of FGFR4/ERK signaling inhibition on HCC following MKI treatment was analyzed in vitro and in vivo assays. Serum FGF19 in HCC patients treated using MKIs, such as sorafenib (n = 173) and lenvatinib (n = 40), was measured by enzyme-linked immunosorbent assay. Lenvatinib strongly inhibited the phosphorylation of FRS2 and ERK, the downstream signaling molecules of FGFR4, compared with sorafenib and regorafenib. Additional use of a selective FGFR4 inhibitor with sorafenib further suppressed FGFR4/ERK signaling and synergistically inhibited HCC cell growth in culture and xenograft subcutaneous tumors. Although serum FGF19high (n = 68) patients treated using sorafenib exhibited a significantly shorter progression-free survival and overall survival than FGF19low (n = 105) patients, there were no significant differences between FGF19high (n = 21) and FGF19low (n = 19) patients treated using lenvatinib. In conclusion, robust inhibition of FGF19/FGFR4 is of importance for the exertion of antitumor effects of MKIs. Serum FGF19 levels may function as a predictive marker for drug response and survival in HCC patients treated using sorafenib.


2021 ◽  
Vol 22 (4) ◽  
pp. 2204
Author(s):  
Simon Grootendorst ◽  
Jonathan de Wilde ◽  
Birgit van Dooijeweert ◽  
Annelies van Vuren ◽  
Wouter van Solinge ◽  
...  

Rare hereditary anemias (RHA) represent a group of disorders characterized by either impaired production of erythrocytes or decreased survival (i.e., hemolysis). In RHA, the regulation of iron metabolism and erythropoiesis is often disturbed, leading to iron overload or worsening of chronic anemia due to unavailability of iron for erythropoiesis. Whereas iron overload generally is a well-recognized complication in patients requiring regular blood transfusions, it is also a significant problem in a large proportion of patients with RHA that are not transfusion dependent. This indicates that RHA share disease-specific defects in erythroid development that are linked to intrinsic defects in iron metabolism. In this review, we discuss the key regulators involved in the interplay between iron and erythropoiesis and their importance in the spectrum of RHA.


Author(s):  
Wen-Dai Bao ◽  
Pei Pang ◽  
Xiao-Ting Zhou ◽  
Fan Hu ◽  
Wan Xiong ◽  
...  

AbstractIron homeostasis disturbance has been implicated in Alzheimer’s disease (AD), and excess iron exacerbates oxidative damage and cognitive defects. Ferroptosis is a nonapoptotic form of cell death dependent upon intracellular iron. However, the involvement of ferroptosis in the pathogenesis of AD remains elusive. Here, we report that ferroportin1 (Fpn), the only identified mammalian nonheme iron exporter, was downregulated in the brains of APPswe/PS1dE9 mice as an Alzheimer’s mouse model and Alzheimer’s patients. Genetic deletion of Fpn in principal neurons of the neocortex and hippocampus by breeding Fpnfl/fl mice with NEX-Cre mice led to AD-like hippocampal atrophy and memory deficits. Interestingly, the canonical morphological and molecular characteristics of ferroptosis were observed in both Fpnfl/fl/NEXcre and AD mice. Gene set enrichment analysis (GSEA) of ferroptosis-related RNA-seq data showed that the differentially expressed genes were highly enriched in gene sets associated with AD. Furthermore, administration of specific inhibitors of ferroptosis effectively reduced the neuronal death and memory impairments induced by Aβ aggregation in vitro and in vivo. In addition, restoring Fpn ameliorated ferroptosis and memory impairment in APPswe/PS1dE9 mice. Our study demonstrates the critical role of Fpn and ferroptosis in the progression of AD, thus provides promising therapeutic approaches for this disease.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1414
Author(s):  
Josep M. Cambra ◽  
Emilio A. Martinez ◽  
Heriberto Rodriguez-Martinez ◽  
Maria A. Gil ◽  
Cristina Cuello

The development of chemically defined media is a growing trend in in vitro embryo production (IVP). Recently, traditional undefined culture medium with bovine serum albumin (BSA) has been successfully replaced by a chemically defined medium using substances with embryotrophic properties such as platelet factor 4 (PF4). Although the use of this medium sustains IVP, the impact of defined media on the embryonic transcriptome has not been fully elucidated. This study analyzed the transcriptome of porcine IVP blastocysts, cultured in defined (PF4 group) and undefined media (BSA group) by microarrays. In vivo-derived blastocysts (IVV group) were used as a standard of maximum embryo quality. The results showed no differentially expressed genes (DEG) between the PF4 and BSA groups. However, a total of 2780 and 2577 DEGs were detected when comparing the PF4 or the BSA group with the IVV group, respectively. Most of these genes were common in both in vitro groups (2132) and present in some enriched pathways, such as cell cycle, lysosome and/or metabolic pathways. These results show that IVP conditions strongly affect embryo transcriptome and that the defined culture medium with PF4 is a guaranteed replacement for traditional culture with BSA.


2020 ◽  
Vol 54 (01) ◽  
pp. 37-46
Author(s):  
Kristina Friedland ◽  
Giacomo Silani ◽  
Anita Schuwald ◽  
Carola Stockburger ◽  
Egon Koch ◽  
...  

Abstract Background Silexan, a special essential oil from flowering tops of lavandula angustifolia, is used to treat subsyndromal anxiety disorders. In a recent clinical trial, Silexan also showed antidepressant effects in patients suffering from mixed anxiety-depression (ICD-10 F41.2). Since preclinical data explaining antidepressant properties of Silexan are missing, we decided to investigate if Silexan also shows antidepressant-like effects in vitro as well as in vivo models. Methods We used the forced swimming test (FST) in rats as a simple behavioral test indicative of antidepressant activity in vivo. As environmental events and other risk factors contribute to depression through converging molecular and cellular mechanisms that disrupt neuronal function and morphology—resulting in dysfunction of the circuitry that is essential for mood regulation and cognitive function—we investigated the neurotrophic properties of Silexan in neuronal cell lines and primary hippocampal neurons. Results The antidepressant activity of Silexan (30 mg/kg BW) in the FST was comparable to the tricyclic antidepressant imipramine (20 mg/kg BW) after 9-day treatment. Silexan triggered neurite outgrowth and synaptogenesis in 2 different neuronal cell models and led to a significant increase in synaptogenesis in primary hippocampal neurons. Silexan led to a significant phosphorylation of protein kinase A and subsequent CREB phosphorylation. Conclusion Taken together, Silexan demonstrates antidepressant-like effects in cellular as well as animal models for antidepressant activity. Therefore, our data provides preclinical evidence for the clinical antidepressant effects of Silexan in patients with mixed depression and anxiety.


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