Current views on the pharmacological correction of iron deficiency conditions in gynecological practice

GYNECOLOGY ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 300-306
Author(s):  
Aleksandr S. Dukhanin
Keyword(s):  
Molecular Mechanisms ◽  
Ferric Iron ◽  
Reticuloendothelial System ◽  
Feedback Mechanism ◽  
Dissociation Rate ◽  
Plasma Vitamin ◽  
Iron Regulatory Proteins ◽  
Iron Preparation ◽  
Iron Delivery ◽  
Mineral Levels

The review considers features of iron and folic acid (FA) pharmacokinetics, which affect the effective micronutrient support: molecular mechanisms of absorption and distribution, homeostatic processes of maintaining plasma vitamin and mineral levels by the feedback mechanism, including by regulating the deposition. An important characteristic of ferrokinetics is the presence of unique iron exporter ferroportin which is controlled by a family of iron regulatory proteins. Systemic ferrotherapy and oral rout of iron delivery are distinguished. In general, parenteral iron preparation complexes consist of Fe(III) oxide/hydroxide core stabilized by a carbohydrate polymer shell. Once entering the bloodstream, iron complexes are absorbed by resident macrophages of the reticuloendothelial system of the liver, spleen and bone marrow. Systemic Fe(III) preparations are prodrugs, the active part of which, i.e. iron is released in the lysosomal matrix of phagocytes. Oral iron preparations are divided into those containing bivalent (ferrous) and trivalent (ferric) iron. The article discusses factors determining the differences in the absorption of oral ferrous and ferric iron preparation, the spectrum of side effects, as well as key pharmaceutical approaches to increase the tolerance and adherence of ferrotherapy. These include using preparations containing Fe(II) organic compounds that have a lower dissociation rate than inorganic iron salts as well as slowing down the release of the active Fe(II) pharmaceutical substance from the drug. The review pays special attention to folates as iron synergists and examines the features of FA pharmacokinetics, the molecular basis of synergism, and substantiates the use of combined iron and FA preparations.

scholarly journals A Short Review of Iron Metabolism and Pathophysiology of Iron Disorders

Medicines ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 85 ◽  
Author(s):  
Andronicos Yiannikourides ◽  
Gladys Latunde-Dada
Keyword(s):  
Iron Metabolism ◽  
Iron Homeostasis ◽  
Cellular Proliferation ◽  
Peptide Hormone ◽  
Short Review ◽  
Reticuloendothelial System ◽  
Cellular Level ◽  
Feedback Mechanism ◽  
The Body ◽  
Iron Regulatory Proteins

Iron is a vital trace element for humans, as it plays a crucial role in oxygen transport, oxidative metabolism, cellular proliferation, and many catalytic reactions. To be beneficial, the amount of iron in the human body needs to be maintained within the ideal range. Iron metabolism is one of the most complex processes involving many organs and tissues, the interaction of which is critical for iron homeostasis. No active mechanism for iron excretion exists. Therefore, the amount of iron absorbed by the intestine is tightly controlled to balance the daily losses. The bone marrow is the prime iron consumer in the body, being the site for erythropoiesis, while the reticuloendothelial system is responsible for iron recycling through erythrocyte phagocytosis. The liver has important synthetic, storing, and regulatory functions in iron homeostasis. Among the numerous proteins involved in iron metabolism, hepcidin is a liver-derived peptide hormone, which is the master regulator of iron metabolism. This hormone acts in many target tissues and regulates systemic iron levels through a negative feedback mechanism. Hepcidin synthesis is controlled by several factors such as iron levels, anaemia, infection, inflammation, and erythropoietic activity. In addition to systemic control, iron balance mechanisms also exist at the cellular level and include the interaction between iron-regulatory proteins and iron-responsive elements. Genetic and acquired diseases of the tissues involved in iron metabolism cause a dysregulation of the iron cycle. Consequently, iron deficiency or excess can result, both of which have detrimental effects on the organism.

scholarly journals Regulation of Store-Operated Ca2+ Entry by SARAF

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1887
Author(s):  
Inbal Dagan ◽  
Raz Palty
Keyword(s):  
Molecular Mechanisms ◽  
Feedback Mechanism ◽  
Cellular Biology ◽  
Excitable Cells ◽  
Major Pathway ◽  
Negative Feedback Mechanism ◽  
Crac Channels ◽  
Dependent Inactivation ◽  
Crac Channel ◽  
The One

Calcium (Ca2+) signaling plays a dichotomous role in cellular biology, controlling cell survival and proliferation on the one hand and cellular toxicity and cell death on the other. Store-operated Ca2+ entry (SOCE) by CRAC channels represents a major pathway for Ca2+ entry in non-excitable cells. The CRAC channel has two key components, the endoplasmic reticulum Ca2+ sensor stromal interaction molecule (STIM) and the plasma-membrane Ca2+ channel Orai. Physical coupling between STIM and Orai opens the CRAC channel and the resulting Ca2+ flux is regulated by a negative feedback mechanism of slow Ca2+ dependent inactivation (SCDI). The identification of the SOCE-associated regulatory factor (SARAF) and investigations of its role in SCDI have led to new functional and molecular insights into how SOCE is controlled. In this review, we provide an overview of the functional and molecular mechanisms underlying SCDI and discuss how the interaction between SARAF, STIM1, and Orai1 shapes Ca2+ signaling in cells.

scholarly journals Abnormal Iron and Lipid Metabolism Mediated Ferroptosis in Kidney Diseases and Its Therapeutic Potential

Metabolites ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Xiaoqin Zhang ◽  
Xiaogang Li
Keyword(s):  
Kidney Disease ◽  
Signaling Pathways ◽  
Metabolic Pathways ◽  
Molecular Mechanisms ◽  
Unsaturated Fatty Acids ◽  
Therapeutic Potential ◽  
Kidney Diseases ◽  
Intracellular Iron ◽  
Metabolic Signaling ◽  
Iron Regulatory Proteins

Ferroptosis is a newly identified form of regulated cell death driven by iron-dependent phospholipid peroxidation and oxidative stress. Ferroptosis has distinct biological and morphology characteristics, such as shrunken mitochondria when compared to other known regulated cell deaths. The regulation of ferroptosis includes different molecular mechanisms and multiple cellular metabolic pathways, including glutathione/glutathione peroxidase 4(GPX4) signaling pathways, which are involved in the amino acid metabolism and the activation of GPX4; iron metabolic signaling pathways, which are involved in the regulation of iron import/export and the storage/release of intracellular iron through iron-regulatory proteins (IRPs), and lipid metabolic signaling pathways, which are involved in the metabolism of unsaturated fatty acids in cell membranes. Ferroptosis plays an essential role in the pathology of various kidneys diseases, including acute kidney injury (AKI), chronic kidney disease (CKD), autosomal dominant polycystic kidney disease (ADPKD), and renal cell carcinoma (RCC). Targeting ferroptosis with its inducers/initiators and inhibitors can modulate the progression of kidney diseases in animal models. In this review, we discuss the characteristics of ferroptosis and the ferroptosis-based mechanisms, highlighting the potential role of the main ferroptosis-associated metabolic pathways in the treatment and prevention of various kidney diseases.

scholarly journals The dissociation mechanism of processive cellulases

2019 ◽  
Vol 116 (46) ◽  
pp. 23061-23067 ◽  
Author(s):  
Josh V. Vermaas ◽  
Riin Kont ◽  
Gregg T. Beckham ◽  
Michael F. Crowley ◽  
Mikael Gudmundsson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Molecular Mechanisms ◽  
Soluble Sugars ◽  
Dissociation Rate ◽  
Replica Exchange ◽  
Wild Type ◽  
Replica Exchange Molecular Dynamics ◽  
Hamiltonian Replica Exchange ◽  
Biochemical Measurements ◽  
Rate Limiting

Cellulase enzymes deconstruct recalcitrant cellulose into soluble sugars, making them a biocatalyst of biotechnological interest for use in the nascent lignocellulosic bioeconomy. Cellobiohydrolases (CBHs) are cellulases capable of liberating many sugar molecules in a processive manner without dissociating from the substrate. Within the complete processive cycle of CBHs, dissociation from the cellulose substrate is rate limiting, but the molecular mechanism of this step is unknown. Here, we present a direct comparison of potential molecular mechanisms for dissociation via Hamiltonian replica exchange molecular dynamics of the model fungal CBH, Trichoderma reesei Cel7A. Computational rate estimates indicate that stepwise cellulose dethreading from the binding tunnel is 4 orders of magnitude faster than a clamshell mechanism, in which the substrate-enclosing loops open and release the substrate without reversing. We also present the crystal structure of a disulfide variant that covalently links substrate-enclosing loops on either side of the substrate-binding tunnel, which constitutes a CBH that can only dissociate via stepwise dethreading. Biochemical measurements indicate that this variant has a dissociation rate constant essentially equivalent to the wild type, implying that dethreading is likely the predominant mechanism for dissociation.

Iron homeostasis: new tales from the crypt

Blood ◽  
2000 ◽  
Vol 96 (13) ◽  
pp. 4020-4027 ◽  
Author(s):  
Cindy N. Roy ◽  
Caroline A. Enns
Keyword(s):  
Iron Uptake ◽  
Iron Transport ◽  
Iron Homeostasis ◽  
Molecular Mechanisms ◽  
Hereditary Hemochromatosis ◽  
The Body ◽  
Regulatory Proteins ◽  
Iron Regulatory Proteins ◽  
Duodenal Epithelium ◽  
Related Proteins

Abstract The enterocyte is a highly specialized cell of the duodenal epithelium that coordinates iron uptake and transport into the body. Until recently, the molecular mechanisms underlying iron absorption and iron homeostasis have remained a mystery. This review focuses on the proteins and regulatory mechanisms known to be present in the enterocyte precursor cell and in the mature enterocyte. The recent cloning of a basolateral iron transporter and investigations into its regulation provide new insights into possible mechanisms for iron transport and homeostasis. The roles of proteins such as iron regulatory proteins, the hereditary hemochromatosis protein (HFE)–transferrin receptor complex, and hephaestin in regulating this transporter and in regulating iron transport across the intestinal epithelium are discussed. A speculative, but testable, model for the maintenance of iron homeostasis, which incorporates the changes in the iron-related proteins associated with the life cycle of the enterocyte as it journeys from the crypt to the tip of the villous is proposed.

Characteristics of Iron Dextran Utilization in Man

Blood ◽  
1969 ◽  
Vol 34 (3) ◽  
pp. 357-375 ◽  
Author(s):  
PERRY A. HENDERSON ◽  
ROBERT S. HILLMAN
Keyword(s):  
Reticuloendothelial System ◽  
Prolonged Storage ◽  
Iron Level ◽  
Iron Dextran ◽  
Serum Iron Level ◽  
Iron Supply ◽  
Iron Deficient ◽  
Marrow Stroma ◽  
Ionic Iron ◽  
Iron Delivery

Abstract The major portion of iron dextran iron becomes available to the erythroid marrow only after uptake and release of ionic iron by the reticuloendothelial system. With large intravenous infusions, (1000-2000 mg.), the rate of removal of the iron dextran complex from plasma is enough to supply the marrow with more than 200 mg. of iron/day. However, in the present studies the observed rate of iron delivery to the erythroid marrow was far below this level. Although iron supply immediately after infusion was sufficient to permit marrow production to rise to 4-6 times normal, this was maintained for less than two weeks. With time, reticuloendothelial iron dextran stores became less available, the serum iron level fell and marrow production was restricted to levels below twice normal. In fact, large infusion doses and prolonged storage may have made a portion of the iron dextran stores completely unavailable. Thus, an iron deficient type of erythropoiesis appeared in some patients while iron dextran stores were still readily visible on examination of marrow stroma.

Chronic idiopathic thrombocytopenic purpura (ITP): molecular mechanisms and implications for therapy

2004 ◽  
Vol 6 (24) ◽  
pp. 1-17 ◽  
Author(s):  
Per-Ola Andersson ◽  
Hans Wadenvik
Keyword(s):  
T Cells ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Molecular Mechanisms ◽  
Reticuloendothelial System ◽  
Current Status ◽  
Chronic Idiopathic Thrombocytopenic Purpura ◽  
Thrombocytopenic Purpura ◽  
Humoral Immune ◽  
Chronic Itp ◽  
Relative Contribution

Chronic idiopathic thrombocytopenic purpura (ITP) is an immune-mediated disorder in which platelets are prematurely destroyed in the reticuloendothelial system by platelet autoantibodies. However, it is becoming clear that the pivotal process of the humoral immune response in the pathogenesis of the disorder is a complex interaction between antigen-presenting cells, T cells and B cells. Furthermore, it is increasingly evident that regulatory T cells play an important role and that T-cell-mediated cytotoxicity contributes to the destruction of platelets in ITP. Different new approaches to immunotherapy in chronic ITP have been explored, including use of anti-CD20, anti-CD154 and anti-CD52 antibodies. So far, these therapies have been antigen-nonspecific and the risk of general immunosuppression is a concern. Thus, improving our understanding of the interaction and relative contribution of humoral and cell-mediated mechanisms is essential for developing antigen-specific immunotherapies for the treatment of this disorder. This review aims to elucidate the current status of knowledge of the cellular and humoral immune components of chronic ITP, together with the implications of this knowledge for therapy.

Iron homeostasis: new tales from the crypt

Blood ◽  
2000 ◽  
Vol 96 (13) ◽  
pp. 4020-4027 ◽  
Author(s):  
Cindy N. Roy ◽  
Caroline A. Enns
Keyword(s):  
Iron Uptake ◽  
Iron Transport ◽  
Iron Homeostasis ◽  
Molecular Mechanisms ◽  
Hereditary Hemochromatosis ◽  
The Body ◽  
Regulatory Proteins ◽  
Iron Regulatory Proteins ◽  
Duodenal Epithelium ◽  
Related Proteins

The enterocyte is a highly specialized cell of the duodenal epithelium that coordinates iron uptake and transport into the body. Until recently, the molecular mechanisms underlying iron absorption and iron homeostasis have remained a mystery. This review focuses on the proteins and regulatory mechanisms known to be present in the enterocyte precursor cell and in the mature enterocyte. The recent cloning of a basolateral iron transporter and investigations into its regulation provide new insights into possible mechanisms for iron transport and homeostasis. The roles of proteins such as iron regulatory proteins, the hereditary hemochromatosis protein (HFE)–transferrin receptor complex, and hephaestin in regulating this transporter and in regulating iron transport across the intestinal epithelium are discussed. A speculative, but testable, model for the maintenance of iron homeostasis, which incorporates the changes in the iron-related proteins associated with the life cycle of the enterocyte as it journeys from the crypt to the tip of the villous is proposed.

scholarly journals GRIP1 is required for homeostatic regulation of AMPAR trafficking

2015 ◽  
Vol 112 (32) ◽  
pp. 10026-10031 ◽  
Author(s):  
Han L. Tan ◽  
Bridget N. Queenan ◽  
Richard L. Huganir
Keyword(s):  
Molecular Mechanisms ◽  
Feedback Mechanism ◽  
Homeostatic Plasticity ◽  
Homeostatic Regulation ◽  
Synaptic Scaling ◽  
Negative Feedback Mechanism ◽  
Ampar Trafficking ◽  
The Central Nervous System ◽  
Biochemical Genetic ◽  
Zona Occludens

Homeostatic plasticity is a negative feedback mechanism that stabilizes neurons during periods of perturbed activity. The best-studied form of homeostatic plasticity in the central nervous system is the scaling of excitatory synapses. Postsynaptic AMPA-type glutamate receptors (AMPARs) can be inserted into synapses to compensate for neuronal inactivity or removed to compensate for hyperactivity. However, the molecular mechanisms underlying the homeostatic regulation of AMPARs remain elusive. Here, we show that the expression of GRIP1, a multi-PDZ (postsynaptic density 95/discs large/zona occludens) domain AMPAR-binding protein, is bidirectionally altered by neuronal activity. Furthermore, we observe a subcellular redistribution of GRIP1 and a change in the binding of GRIP1 to GluA2 during synaptic scaling. Using a combination of biochemical, genetic, and electrophysiological methods, we find that loss of GRIP1 blocks the accumulation of surface AMPARs and the scaling up of synaptic strength that occur in response to chronic activity blockade. Collectively, our data point to an essential role of GRIP1-mediated AMPAR trafficking during inactivity-induced synaptic scaling.

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