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Iron stain in spleen and liver in wild-type and heterozygous Fth / mice. Perls Prussian blue staining of liver (panel A) or spleen (panels B-F) from wild-type (panels A-C) or heterozygous (panels D-F) animals. Animals were analyzed at 6 weeks (panels B,D), 10 weeks (panel E), or 25 weeks (panels A,C,F) after birth. In both genotypes, there is a progressive iron loading of the spleen red pulp, with very few blue deposits in the white pulp, whereas there is no stainable iron in the liver ( 100).
Source publication
Ferritin, the iron-storing molecule, is made by the assembly of various proportions of 2 different H and L subunits into a 24-mer protein shell. These heteropolymers have distinct physicochemical properties, owing to the ferroxidase activity of the H subunit, which is necessary for iron uptake by the ferritin molecule, and the ability of the L subu...
Contexts in source publication
Context 1
... might be due to C57BL/6 and 129SV iron-related genes segregating in the F 2 mice. It is noteworthy that in mice, the spleen appears as a major site of iron storage since iron accumulation is readily detectable by Perls blue staining ( Figure 1C, E-F), whereas it is not in the liver ( Figure 1A). Ultrastructural analysis of a 25-week-old spleen shows that iron accumulates only in macrophages ( Figure 2A). ...
Context 2
... might be due to C57BL/6 and 129SV iron-related genes segregating in the F 2 mice. It is noteworthy that in mice, the spleen appears as a major site of iron storage since iron accumulation is readily detectable by Perls blue staining ( Figure 1C, E-F), whereas it is not in the liver ( Figure 1A). Ultrastructural analysis of a 25-week-old spleen shows that iron accumulates only in macrophages ( Figure 2A). ...
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Citations
... Hence, with this report, we intend to study the role of tumor extrinsic FTH1 on GBM and further investigate the extent of sexual dimorphism in its impact on GBMs by introducing a novel animal model in which one copy of the Fth1 gene has been deleted. Homozygous deletion of Fth1 is known to be embryonically lethal [21]. The Fth1 heterozygous knockout mice model used here has a 2-fold reduction in systemic H-ferritin levels [21]. ...
... Homozygous deletion of Fth1 is known to be embryonically lethal [21]. The Fth1 heterozygous knockout mice model used here has a 2-fold reduction in systemic H-ferritin levels [21]. However, the Fth1 in tumor cells that are injected in these mice is not manipulated/modified in any other manner. ...
... The results of this study demonstrate that genetic manipulation of Fth1 which alters FTH1 protein expression (twofold reduction of protein in blood [21]) impacts survival in female mice but not in male mice with GBMs. Furthermore, we show that this genetic manipulation is associated with altered tumor infiltration of immune cells such as T-cells, and CD8 + T cells, and stromal cells such as mast cells and fibroblasts. ...
Purpose
Iron plays a crucial role in various biological mechanisms and has been found to promote tumor growth. Recent research has shown that the H-ferritin (FTH1) protein, traditionally recognized as an essential iron storage protein, can transport iron to GBM cancer stem cells, reducing their invasion activity. Moreover, the binding of extracellular FTH1 to human GBM tissues, and brain iron delivery in general, has been found to have a sex bias. These observations raise questions, addressed in this study, about whether H-ferritin levels extrinsic to the tumor can affect tumor cell pathways and if this impact is sex-specific.
Methods
To interrogate the role of systemic H-ferritin in GBM we introduce a mouse model in which H-ferritin levels are genetically manipulated. Mice that were genetically manipulated to be heterozygous for H-ferritin (Fth1+/-) gene expression were orthotopically implanted with a mouse GBM cell line (GL261). Littermate Fth1 +/+ mice were used as controls. The animals were evaluated for survival and the tumors were subjected to RNA sequencing protocols. We analyzed the resulting data utilizing the murine Microenvironment Cell Population (mMCP) method for in silico immune deconvolution. mMCP analysis estimates the abundance of tissue infiltrating immune and stromal populations based on cell-specific gene expression signatures.
Results
There was a clear sex bias in survival. Female Fth1+/- mice had significantly poorer survival than control females (Fth1+/+). The Fth1 genetic status did not affect survival in males. The mMCP analysis revealed a significant reduction in T cells and CD8 + T cell infiltration in the tumors of females with Fth1+/- background as compared to the Fth1+/+. Mast and fibroblast cell infiltration was increased in females and males with Fth1+/- background, respectively, compared to Fth1+/+ mice.
Conclusion
Genetic manipulation of Fth1 which leads to reduced systemic levels of FTH1 protein had a sexually dimorphic impact on survival. Fth1 heterozygosity significantly worsened survival in females but did not affect survival in male GBMs. Furthermore, the genetic manipulation of Fth1 significantly affected tumor infiltration of T-cells, CD8 + T cells, fibroblasts, and mast cells in a sexually dimorphic manner. These results demonstrate a role for FTH1 and presumably iron status in establishing the tumor cellular landscape that ultimately impacts survival and further reveals a sex bias that may inform the population studies showing a sex effect on the prevalence of brain tumors.
... In addition, P4 exerts a natriuretic effect due to its aldosterone antagonism, resulting in plasma sodium and water loss [43,44]. Thus, hormone-associated changes in plasma volume and plasma protein concentration, that occur during the menstrual cycle, offer a possible mechanism to explain differences in iron status indicators at different phases of the estrous cycle. ...
Several studies have demonstrated that in woman the sex hormones such as estrogen (E2) and progesterone (P4) influence iron (Fe) regulation, contributing to variations in Fe parameters along the menstrual cycle. These mechanisms based on the regulation of hepcidin (Hepc) which limits Fe availability during the cycle, remain poorly characterized in healthy mares. The objective of this study was to establish the relationship between Hepc, Fe, ferritin (Ferr), and the primary ovarian hormones E2 and P4 in cycling Purebred Spanish mares. Blood samples were taken from 31 Purebred Spanish mares day −5, on day 0, day +5 and day +16 of the cycle. Fe and Ferr significantly increased and Hepc decreased during pre- and ovulatory periods. The secretion peak of estradiol-17β (E2) was reached on day 0 and progesterone (P4) between days +5 and +16. Fe and Ferr were positively correlated (r = 0.57). Fe and Ferr were negatively correlated with Hepc (r = −0.72 and r = −0.02, respectively). E2 and P4 were negatively and positively correlated with Hepc (r = −0.753 and r = 0.54, respectively). In cycling Purebred Spanish mares there is a measurable relationship between steroid hormones and systemic Fe metabolism. Estrogenic dominance in the pre- and ovulatory period allows for a more effective iron status, mediated by hepcidin inhibition. However, P4 during the luteal phase substantially reduces serum Fe and iron stores, possibly related to Hepc stimulation. Future research is required to clarify the relationship between steroid hormones and iron metabolism at the molecular level in equids.
... Excessive iron increases hepatic hepcidin expression which causes macrophages to sequester iron [10]. Iron can deposit in splenic macrophages in the form of hemosiderin [11,12]. ...
Hereditary hemochromatosis is an iron-overload disease most often arising from a mutation in the Homeostatic Fe regulator (HFE) gene. HFE organs become overloaded with iron which causes damage. Iron-overload is commonly detected by NMR imaging, but the spectroscopic technique is insensitive to diamagnetic iron. Here, we used Mössbauer spectroscopy to examine the iron content of liver, spleen, kidney, heart, and brain of ⁵⁷ Fe-enriched HFE (−/−) mice of ages 3–52 wk. Overall, the iron contents of all investigated HFE organs were similar to the same healthy organ but from an older mouse . Livers and spleens were majorly overloaded, followed by kidneys. Excess iron was generally present as ferritin. Iron–sulfur clusters and low-spin Fe II hemes (combined into the central quadrupole doublet) and nonheme high-spin Fe II species were also observed. Spectra of young and middle-aged HFE kidneys were dominated by the central quadrupole doublet and were largely devoid of ferritin. Collecting and comparing spectra at 5 and 60 K allowed the presence of hemosiderin, a decomposition product of ferritin, to be quantified, and it also allowed the diamagnetic central doublet to be distinguished from ferritin. Hemosiderin was observed in spleens and livers from HFE mice, and in spleens from controls, but only when iron concentrations exceeded 2–3 mM. Even in those cases, hemosiderin represented only 10–20% of the iron in the sample. NMR imaging can identify iron-overload under non-invasive room-temperature conditions, but Mössbauer spectroscopy of ⁵⁷ Fe-enriched mice can detect all forms of iron and perhaps allow the process of iron-overloading to be probed in greater detail.
Graphical Abstract
... The ratio of FTH1 and FTL1 in ferritin is speci c, and ratio H/L and ferritin are essential for cell survival. These two subunits are not interchangeable, and FTL1 cannot compensate for the function of FTH1 (29). FTH1 plays an essential role in the regulation of proliferation, angiogenesis, migration, EMT, stemness, in ammation and immunoregulation. ...
Currently, FTH1 has been increasingly found to play a crucial role in cancer as a core regulator of ferroptosis, while its role of non-ferroptosis in HNSCC is still unclear. Herein, we analyzed the expression level of FTH1 in HNSCC using TCGA database and FTH1 protein in HNSCC tissues and cell lines was determined by immunohistochemistry (IHC) and western blotting, respectively. Then, its prognostic value and relationship with clinical parameters were investigated in HNSCC patients. Additionally, the biological function and its molecular mechanism of FTH1 in HNSCC were explored. The current study showed that FTH1 is significantly overexpressed in HNSCC tissues and related to poor prognosis and lymph node metastasis of HNSCC. FTH1 knockdown could suppress the metastasis and epithelial-mesenchymal transition (EMT) process of HNSCC and we further demonstrated that it may be caused by the inactivation of β-catenin/ZEB1 through HMOX1. Taken together, our findings indicate that FTH1 plays a critical role in the progression and metastasis of HNSCC and can serve as a promising prognostic factor and therapeutic target in HNSCC.
... It is, of course, possible that some horses in this study had greater Fe absorption than others and that this may have led to IR. However, in humans it has been shown that even individuals with hemochromatosis, a genetic condition that gives rise to the absorption of excessive amounts of Fe, do not have any higher incidence of IR than human subjects without this condition [22,23] It should also be kept in mind at this point that serum ferritin is not necessarily indicative of Fe overload as Fe and ferritin can be regulated independently from one another [24]. Instead, serum ferritin is a known marker of inflammation and cellular damage and may in fact not be 'carrying' much Fe at all. ...
Racehorses are often supplemented extra iron with the expectation that the iron will improve overall performance and health. A survey of 120 U.S. Thoroughbred trainers, representing 1978 Thoroughbreds from various regions of the U.S., was conducted to determine the average amount of dietary iron fed to Thoroughbred racehorses per day. Survey results indicated racehorses were fed an average of 3900 mg of iron per day from hay and grain alone. This exceeds the 0.8 mg/kg BW or 400 mg for a 500 kg working horse that the NRC 2007 recommends per day. Supplements increased the daily average intake of iron by an additional 500 mg Fe. Some equine nutritionists propose that excess dietary iron may be a causative factor in insulin resistance (IR). However, the occurrence of IR in Thoroughbred racehorses is very rare. This study did not find one confirmed veterinary diagnosis of IR in any of the surveyed trainers’ Thoroughbred horses, whether racing, on a layoff, or retired. Given the iron content in these diets easily exceeds the NRC minimum daily requirements, it seems unlikely that dietary iron is an independent causative factor in IR.
... Indeed, plasma levels of TIM-1 have been found to be associated with underlying tubulointerstitial and mesangial lesions and progression to kidney failure in two cohort studies of individuals with kidney diseases [104]. Preclinical investigations have demonstrated that TIM-2, the rodent homolog to TIM-1, is a binding partner to H-ferritin [105], a protein initially thought to be solely used for iron storage [106][107][108], which was later shown to serve as an iron delivery protein, secreted from the endothelial cells within the BBB as a source of iron for the brain [109]. TIM-1 can also mediate the tethering between T cells and endothelial cells in vivo and the rolling of lymphocytes on the vascular endothelium [110]. ...
T-cell immunoglobulin and mucin domain 1 (TIM-1) has been recently identified as one of the factors involved in the internalization of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human cells, in addition to angiotensin-converting enzyme 2 (ACE2), trans-membrane serine protease 2 (TMPRSS2), neuropilin-1, and others. We hypothesized that specific microRNAs could target TIM-1, with potential implications for the management of patients suffering from coronavirus disease 2019 (COVID-19). By combining bioinformatic analyses and functional as-says, we identified miR-142 as a specific regulator of TIM-1 transcription. Since TIM-1 has been implicated in the regulation of endothelial function at the level of the blood-brain barrier (BBB) and its levels have been shown to be associated with stroke and cerebral ischemia-reperfusion injury, we validated miR-142 as a functional modulator of TIM-1 in human brain microvascular endothelial cells (hBMECs). Taken together, our results indicate that miR-142 targets TIM-1, representing a novel strategy against cerebrovascular disorders, as well as systemic complications of SARS-CoV-2 and other viral infections.
... [42]. Heterozygous of FT-HC (±) have 7-10-fold elevated serum FT-LC levels, without any changes in serum iron concentration, and higher FT-LC levels in the heart [43]. Additionally, following iron injections, stimulation of FT-HC production rose two-fold in the heart and was identical in all the organs. ...
Heart failure (HF) is a common disease that causes significant limitations on the organism’s capacity and, in extreme cases, leads to death. Clinically, iron deficiency (ID) plays an essential role in heart failure by deteriorating the patient’s condition and is a prognostic marker indicating poor clinical outcomes. Therefore, in HF patients, supplementation of iron is recommended. However, iron treatment may cause adverse effects by increasing iron-related apoptosis and the production of oxygen radicals, which may cause additional heart damage. Furthermore, many knowledge gaps exist regarding the complex interplay between iron deficiency and heart failure. Here, we describe the current, comprehensive knowledge about the role of the proteins involved in iron metabolism. We will focus on the molecular and clinical aspects of iron deficiency in HF. We believe that summarizing the new advances in the translational and clinical research regarding iron deficiency in heart failure should broaden clinicians’ awareness of this comorbidity.
... The lack of hinokitiol-mediated release of iron from the spleen may be due to a paucity of mobile iron in this tissue. Specifically, there is twofold more L-ferritin (per gram tissue) in the spleen than in the liver in wildtype mice (58). Based on this information, we hypothesize that more of the iron in splenic macrophages is ferritin bound/nonlabile and that this may explain why hinokitiol is less able to mobilize the iron retained in the spleen (26). ...
Deficiencies of the transmembrane iron-transporting protein ferroportin (FPN1) cause the iron misdistribution that underlies ferroportin disease, anemia of inflammation, and several other human diseases and conditions. A small molecule natural product, hinokitiol, was recently shown to serve as a surrogate transmembrane iron transporter that can restore hemoglobinization in zebrafish deficient in other iron transporting proteins and can increase gut iron absorption in FPN1-deficient flatiron mice. However, whether hinokitiol can restore normal iron physiology in FPN1-deficient animals or primary cells from patients and the mechanisms underlying such targeted activities remain unknown. Here, we show that hinokitiol redistributes iron from the liver to red blood cells in flatiron mice, thereby increasing hemoglobin and hematocrit. Mechanistic studies confirm that hinokitiol functions as a surrogate transmembrane iron transporter to release iron trapped within liver macrophages, that hinokitiol-Fe complexes transfer iron to transferrin, and that the resulting transferrin-Fe complexes drive red blood cell maturation in a transferrin-receptor–dependent manner. We also show in FPN1-deficient primary macrophages derived from patients with ferroportin disease that hinokitiol moves labile iron from inside to outside cells and decreases intracellular ferritin levels. The mobilization of nonlabile iron is accompanied by reductions in intracellular ferritin, consistent with the activation of regulated ferritin proteolysis. These findings collectively provide foundational support for the translation of small molecule iron transporters into therapies for human diseases caused by iron misdistribution.
... Herein, we also observed a strong increase in the spleen iron content with age ( Figure 1B). Iron accumulation was previously reported in 25-week old mice [46] but the quantification with age, as achieved here between 6-week and 6-month old mice, was missing, to the best of our knowledge. Endogenous iron and copper can also be expressed in terms ...
Nanoparticles (NPs) are at the leading edge of nanomedicine, and determining their biosafety remains a mandatory precondition for biomedical applications. Herein, we explore the bioassimilation of copper sulfide NPs reported as powerful photo-responsive anticancer therapeutic agents. The nanoparticles investigated present a hollow shell morphology, that can be left empty (CuS NPs) or be filled with an iron oxide flower-like core (iron oxide@CuS NPs), and are compared with the iron oxide nanoparticles only (iron oxide NPs). CuS, iron oxide@CuS and iron oxide NPs were injected in 6-week-old mice, at doses coherent with an antitumoral treatment. Cu and Fe were quantified in the liver, spleen, kidneys, and lungs over 6 months, including the control animals, thus providing endogenous Cu and Fe levels in the first months after animal birth. After intravenous NPs administration, 77.0 ± 3.9% of the mass of Cu injected, and 78.6 ± 3.8% of the mass of Fe, were detected in the liver. In the spleen, we found 3.3 ± 0.6% of the injected Cu and 3.8 ± 0.6% for the Fe. No negative impact was observed on organ weight, nor on Cu or Fe homeostasis in the long term. The mass of the two metals returned to the control values within three months, a result that was confirmed by transmission electron microscopy and histology images. This bioassimilation with no negative impact comforts the possible translation of these nanomaterials into clinical practice.
... This ratio H/L, as well as total ferritin, is critical to cell survival. Indeed, FTL and FTH1 subunits are not interchangeable, and FTL is unable to compensate for the function of FTH1 in knockout mice [28,29]. ...
Ferritin, the principal intracellular iron-storage protein localized in the cytoplasm, nucleus, and mitochondria, plays a major role in iron metabolism. The encoding ferritin genes are members of a multigene family that includes some pseudogenes. Even though pseudogenes have been initially considered as relics of ancient genes or junk DNA devoid of function, their role in controlling gene expression in normal and transformed cells has recently been re-evaluated. Numerous studies have revealed that some pseudogenes compete with their parental gene for binding to the microRNAs (miRNAs), while others generate small interference RNAs (siRNAs) to decrease functional gene expression, and still others encode functional mutated proteins. Consequently, pseudogenes can be considered as actual master regulators of numerous biological processes. Here, we provide a detailed classification and description of the structural features of the ferritin pseudogenes known to date and review the recent evidence on their mutual interrelation within the complex regulatory network of the ferritin gene family.
