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1.
Int J Nanomedicine ; 16: 283-296, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33469287

RESUMO

Methods: In this study, we used MTT assays to demonstrate that a combination of SPIO-Serum and wild-type p53 overexpression can reduce ovarian cancer cell viability in vitro. Prussian blue staining and iron assays were used to determine changes in intracellular iron concentration following SPIO-Serum treatment. TEM was used to evaluate any mitochondrial damage induced by SPIO-Serum treatment, and Western blot was used to evaluate the expression of the iron transporter and lipid peroxidation regulator proteins. JC-1 was used to measure mitochondrial membrane potential, and ROS levels were estimated by flow cytometry. Finally, xCT protein expression and mitochondrial ROS levels were confirmed using fluorescence microscopy. Results: SPIO-Serum effectively induced lipid peroxidation and generated abundant toxic ROS. It also facilitated the downregulation of GPX4 and xCT, ultimately resulting in iron-dependent oxidative death. These effects could be reversed by iron chelator DFO and lipid peroxidation inhibitor Fer-1. SPIO-Serum treatment disrupted intracellular iron homeostasis by regulating iron uptake and the cells presented with missing mitochondrial cristae and ruptured outer mitochondrial membranes. Moreover, we were able to show that p53 contributed to SPIO-Serum-induced ferroptosis in ovarian cancer cells. Conclusion: SPIO-Serum induced ferroptosis and overexpressed p53 contributed to ferroptosis in ovarian cancer cells. Our data provide a theoretical basis for ferroptosis as a novel cell death phenotype induced by nanomaterials.


Assuntos
Ferroptose , Neoplasias Ovarianas/patologia , Soro/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Feminino , Humanos , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Modelos Biológicos , Neoplasias Ovarianas/metabolismo , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Receptores da Transferrina/metabolismo , Transferrina/metabolismo
2.
PLoS Negl Trop Dis ; 14(12): e0009004, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33370288

RESUMO

A detailed understanding of the mechanisms underlying the capacity of a virus to break the species barrier is crucial for pathogen surveillance and control. New World (NW) mammarenaviruses constitute a diverse group of rodent-borne pathogens that includes several causative agents of severe viral hemorrhagic fever in humans. The ability of the NW mammarenaviral attachment glycoprotein (GP) to utilize human transferrin receptor 1 (hTfR1) as a primary entry receptor plays a key role in dictating zoonotic potential. The recent isolation of Tacaribe and lymphocytic choriominingitis mammarenaviruses from host-seeking ticks provided evidence for the presence of mammarenaviruses in arthropods, which are established vectors for numerous other viral pathogens. Here, using next generation sequencing to search for other mammarenaviruses in ticks, we identified a novel replication-competent strain of the NW mammarenavirus Tamiami (TAMV-FL), which we found capable of utilizing hTfR1 to enter mammalian cells. During isolation through serial passaging in mammalian immunocompetent cells, the quasispecies of TAMV-FL acquired and enriched mutations leading to the amino acid changes N151K and D156N, within GP. Cell entry studies revealed that both substitutions, N151K and D156N, increased dependence of the virus on hTfR1 and binding to heparan sulfate proteoglycans. Moreover, we show that the substituted residues likely map to the sterically constrained trimeric axis of GP, and facilitate viral fusion at a lower pH, resulting in viral egress from later endosomal compartments. In summary, we identify and characterize a naturally occurring TAMV strain (TAMV-FL) within ticks that is able to utilize hTfR1. The TAMV-FL significantly diverged from previous TAMV isolates, demonstrating that TAMV quasispecies exhibit striking genetic plasticity that may facilitate zoonotic spillover and rapid adaptation to new hosts.


Assuntos
Antígenos CD/metabolismo , Infecções por Arenaviridae/transmissão , Arenaviridae/genética , Receptores da Transferrina/metabolismo , Receptores Virais/metabolismo , Proteínas do Envelope Viral/genética , Sequência de Aminoácidos/genética , Animais , Arenaviridae/isolamento & purificação , Linhagem Celular , Chlorocebus aethiops , Células HEK293 , Humanos , Insetos Vetores/virologia , Alinhamento de Sequência , Carrapatos/virologia , Células Vero , Zoonoses/transmissão , Zoonoses/virologia
3.
PLoS One ; 15(12): e0243812, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33351833

RESUMO

BACKGROUND: Iron metabolism is essential because it plays regulatory roles in various physiological and pathological processes. Disorders of iron metabolism balance are related to various cancers, including hepatocellular carcinoma. Cancer stem-like cells (CSCs) exert critical effects on chemotherapy failure, cancer metastasis, and subsequent disease recurrence and relapse. However, little is known about how iron metabolism affects liver CSCs. Here, we investigated the expression of transferrin receptor 1 (TFR1) and ferroportin (FPN), two iron importers, and an upstream regulator, iron regulatory protein 2 (IRP2), in liver hepatocellular carcinoma (LIHC) and related CSCs. METHODS: The expression levels of TFR1, FPN and IRP2 were analysed using the GEPIA database. CSCs were derived from parental LIHC cells cultured in serum-free medium. After TFR1 knockdown, ROS accumulation and malignant behaviours were measured. The CCK-8 assay was performed to detect cell viability after TFR1 knockdown and erastin treatment. RESULTS: TFR1 expression was upregulated in LIHC tissue and CSCs derived from LIHC cell lines, prompting us to investigate the roles of TFR1 in regulating CSCs. Knockdown of TFR1 expression decreased iron accumulation and inhibited malignant behaviour. Knockdown of TFR1 expression decreased reactive oxygen species (ROS) accumulation induced by erastin treatment and maintained mitochondrial function, indicating that TFR1 is critical in regulating erastin-induced cell death in CSCs. Additionally, knockdown of TFR1 expression decreased sphere formation by decreasing iron accumulation in CSCs, indicating a potential role for TFR1 in maintaining stemness. CONCLUSION: These findings, which revealed TFR1 as a critical regulator of LIHC CSCs in malignant behaviour and stemness that functions by regulating iron accumulation, may have implications to improve therapeutic approaches.


Assuntos
Carcinoma Hepatocelular/patologia , Ferro/metabolismo , Neoplasias Hepáticas/patologia , Células-Tronco Neoplásicas/patologia , Receptores da Transferrina/metabolismo , Linhagem Celular Tumoral , Humanos , Fenótipo
4.
Int J Nanomedicine ; 15: 6673-6688, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32982226

RESUMO

Background: The safe and efficient delivery of chemotherapeutic agents is critical to glioma therapy. However, chemotherapy for glioma is extremely challenging because the blood-brain barrier (BBB) rigorously prevents drugs from reaching the tumor region. Materials and Methods: TfR-T12 peptide-modified PEG-PLA polymer was synthesized to deliver paclitaxel (PTX) for glioma therapy. TfR was significantly expressed on brain capillary endothelial cells and glioma cells; therefore, TfR-T12 peptide-modified micelles can cross the BBB system and target glioma cells. Results: TfR-T12-PEG-PLA/PTX polymeric micelles (TfR-T12-PMs) could be absorbed rapidly by tumor cells, and traversed effectively the BBB monolayers. TfR-T12-PMs can effectively inhibit the proliferation of U87MG cells in vitro, and TfR-T12-PMs loaded with paclitaxel presented better antiglioma effect with prolonged median survival of nude mice-bearing glioma than the unmodified PMs. Conclusion: The TfR-T12-PMs could effectively overcome the BBB barrier and accomplish glioma-targeted drug delivery, thus validating its potential in improving the therapeutic outcome in multiforme.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Glioblastoma/tratamento farmacológico , Micelas , Animais , Antígenos CD , Barreira Hematoencefálica/efeitos dos fármacos , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/metabolismo , Glioblastoma/patologia , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Paclitaxel/administração & dosagem , Paclitaxel/farmacologia , Peptídeos/química , Polietilenoglicóis/química , Receptores da Transferrina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Chem Biol Interact ; 329: 109217, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32750324

RESUMO

Developing brain is very sensitive to the influence of environmental factors during gestation and the neonatal period. The aim of the study is to assess cobalt and iron accumulation in the brain as well as changes in the expression of iron-regulatory proteins transferrin receptor 1, hepcidin, and ferroportin in suckling mice. Perinatal exposure to cobalt chloride increased significantly cobalt content in brain tissue homogenates of 18-day-old (d18) and 25-day-old (d25) mice inducing alterations in brain iron homeostasis. Higher degree of transferrin receptor 1 expression was demonstrated in cobalt chloride-exposed mice with no substantial changes between d18 and d25 mice. A weak ferroportin expression was found in 18-day-old control and cobalt-treated mouse brain. Cobalt exposure of d25 mice resulted in increased ferroportin expression in brain compared to the untreated age-matched control group. Hepcidin level in cobalt-exposed groups was decreased in d18 mice and slightly increased in d25 mice. The obtained data contribute for the better understanding of metal toxicity impact on iron homeostasis in the developing brain with further possible implications in neurodegeneration.


Assuntos
Encéfalo/metabolismo , Cobalto/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Proteínas Reguladoras do Ferro/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Cobalto/metabolismo , Feminino , Hepcidinas/genética , Hepcidinas/metabolismo , Ferro/metabolismo , Proteínas Reguladoras do Ferro/genética , Camundongos , Camundongos Endogâmicos ICR , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo
6.
Int J Nanomedicine ; 15: 5491-5501, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32848385

RESUMO

Purpose: Currently, the treatment of brain metastases from non-small cell lung cancer (NSCLC) is rather difficult in the clinic. A combination of small molecule-targeted drug and chemo-drug is a promising therapeutic strategy for the treatment of NSCLC brain metastases. But the efficacy of this combination therapy is not satisfactory due to the blood-brain barrier (BBB). Therefore, it is urgent to develop a drug delivery system to enhance the synergistic therapeutic effects of small molecule-targeted drug and chemo-drug for the treatment of NSCLC brain metastases. Methods: T7 peptide installed and osimertinib (AZD9291) loaded intracellular glutathione (GSH) responsive doxorubicin prodrug self-assembly nanocarriers (T7-DSNPs/9291) have been developed as a targeted co-delivery system to enhance the combined therapeutic effect on brain metastases from NSCLC. In vitro cell experiments, including intracellular uptake assay, in vitro BBB transportation, and MTT assay were used to demonstrate the efficacy of T7-DSNPs/9291 in NSCLC brain metastasis in vitro. Real-time fluorescence imaging analysis, magnetic resonance imaging analysis, and Kaplan-Meier survival curves were used to study the effect of T7-DSNPs/9291 on an animal model in vivo. Results: T7-DSNPs/9291 could significantly enhance BBB penetration of AZD9291 and doxorubicin via transferrin receptor-mediated transcytosis. Moreover, T7-DSNPs/9291 showed significant anti-NSCLC brain metastasis effect and prolonged median survival of an intracranial NSCLC brain metastasis animal model. Conclusion: T7-DSNPs/9291 is a potential drug delivery system for the combined therapy of brain metastasis from NSCLC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Portadores de Fármacos/administração & dosagem , Neoplasias Pulmonares/patologia , Acrilamidas/administração & dosagem , Compostos de Anilina/administração & dosagem , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Barreira Hematoencefálica/efeitos dos fármacos , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/secundário , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Colágeno Tipo IV/química , Doxorrubicina/administração & dosagem , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Camundongos Endogâmicos BALB C , Nanoestruturas/administração & dosagem , Nanoestruturas/química , Fragmentos de Peptídeos/química , Pró-Fármacos/administração & dosagem , Pró-Fármacos/química , Receptores da Transferrina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Nature ; 584(7820): 291-297, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32728216

RESUMO

The majority of therapies that target individual proteins rely on specific activity-modulating interactions with the target protein-for example, enzyme inhibition or ligand blocking. However, several major classes of therapeutically relevant proteins have unknown or inaccessible activity profiles and so cannot be targeted by such strategies. Protein-degradation platforms such as proteolysis-targeting chimaeras (PROTACs)1,2 and others (for example, dTAGs3, Trim-Away4, chaperone-mediated autophagy targeting5 and SNIPERs6) have been developed for proteins that are typically difficult to target; however, these methods involve the manipulation of intracellular protein degradation machinery and are therefore fundamentally limited to proteins that contain cytosolic domains to which ligands can bind and recruit the requisite cellular components. Extracellular and membrane-associated proteins-the products of 40% of all protein-encoding genes7-are key agents in cancer, ageing-related diseases and autoimmune disorders8, and so a general strategy to selectively degrade these proteins has the potential to improve human health. Here we establish the targeted degradation of extracellular and membrane-associated proteins using conjugates that bind both a cell-surface lysosome-shuttling receptor and the extracellular domain of a target protein. These initial lysosome-targeting chimaeras, which we term LYTACs, consist of a small molecule or antibody fused to chemically synthesized glycopeptide ligands that are agonists of the cation-independent mannose-6-phosphate receptor (CI-M6PR). We use LYTACs to develop a CRISPR interference screen that reveals the biochemical pathway for CI-M6PR-mediated cargo internalization in cell lines, and uncover the exocyst complex as a previously unidentified-but essential-component of this pathway. We demonstrate the scope of this platform through the degradation of therapeutically relevant proteins, including apolipoprotein E4, epidermal growth factor receptor, CD71 and programmed death-ligand 1. Our results establish a modular strategy for directing secreted and membrane proteins for lysosomal degradation, with broad implications for biochemical research and for therapeutics.


Assuntos
Espaço Extracelular/metabolismo , Lisossomos/metabolismo , Proteínas de Membrana/metabolismo , Proteólise , Proteínas Recombinantes de Fusão/metabolismo , Animais , Anticorpos/química , Anticorpos/metabolismo , Antígenos CD/metabolismo , Apolipoproteína E4/metabolismo , Antígeno B7-H1/metabolismo , Sistemas CRISPR-Cas , Linhagem Celular , Receptores ErbB/metabolismo , Feminino , Glicopeptídeos/síntese química , Glicopeptídeos/metabolismo , Humanos , Ligantes , Proteínas de Membrana/química , Camundongos , Domínios Proteicos , Transporte Proteico , Receptor IGF Tipo 2/metabolismo , Receptores da Transferrina/metabolismo , Proteínas Recombinantes de Fusão/síntese química , Proteínas Recombinantes de Fusão/química , Solubilidade , Especificidade por Substrato
8.
PLoS Pathog ; 16(7): e1008682, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32730327

RESUMO

Porcine epidemic diarrhea virus (PEDV) mainly infects the intestinal epithelial cells of newborn piglets causing acute, severe atrophic enteritis. The underlying mechanisms of PEDV infection and the reasons why newborn piglets are more susceptible than older pigs remain incompletely understood. Iron deficiency is common in newborn piglets. Here we found that high levels of transferrin receptor 1 (TfR1) distributed in the apical tissue of the intestinal villi of newborns, and intracellular iron levels influence the susceptibility of newborn piglets to PEDV. We show that iron deficiency induced by deferoxamine (DFO, an iron chelating agent) promotes PEDV infection while iron accumulation induced by ferric ammonium citrate (FAC, an iron supplement) impairs PEDV infection in vitro and in vivo. Besides, PEDV infection was inhibited by occluding TfR1 with antibodies or decreasing TfR1 expression. Additionally, PEDV infection was increased in PEDV-resistant Caco-2 and HEK 293T cells over-expressed porcine TfR1. Mechanistically, the PEDV S1 protein interacts with the extracellular region of TfR1 during PEDV entry, promotes TfR1 re-localization and clustering, then activates TfR1 tyrosine phosphorylation mediated by Src kinase, and heightens the internalization of TfR1, thereby promoting PEDV entry. Taken together, these data suggest that the higher expression of TfR1 in the apical tissue of the intestinal villi caused by iron deficiency, accounts for newborn piglets being acutely susceptible to PEDV.


Assuntos
Infecções por Coronavirus/veterinária , Suscetibilidade a Doenças/metabolismo , Mucosa Intestinal/metabolismo , Vírus da Diarreia Epidêmica Suína , Receptores da Transferrina/metabolismo , Doenças dos Suínos/metabolismo , Animais , Animais Recém-Nascidos , Suscetibilidade a Doenças/virologia , Ferro/deficiência , Suínos , Doenças dos Suínos/virologia
9.
PLoS Biol ; 18(7): e3000778, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32678845

RESUMO

The evolution of transformed cancer cells into metastatic tumors is, in part, driven by altered intracellular signaling downstream of receptor tyrosine kinases (RTKs). The surface levels and activity of RTKs are governed mainly through clathrin-mediated endocytosis (CME), endosomal recycling, or degradation. In turn, oncogenic signaling downstream of RTKs can reciprocally regulate endocytic trafficking by creating feedback loops in cells to enhance tumor progression. We previously showed that FCH/F-BAR and Double SH3 Domain-Containing Protein (FCHSD2) has a cancer-cell specific function in regulating CME in non-small-cell lung cancer (NSCLC) cells. Here, we report that FCHSD2 loss impacts recycling of the RTKs, epidermal growth factor receptor (EGFR) and proto-oncogene c-Met (MET), and shunts their trafficking into late endosomes and lysosomal degradation. Notably, FCHSD2 depletion results in the nuclear translocation of active extracellular signal-regulated kinase 1 and 2 (ERK1/2), leading to enhanced transcription and up-regulation of EGFR and MET. The small GTPase, Ras-related protein Rab-7A (Rab7), is essential for the FCHSD2 depletion-induced effects. Correspondingly, FCHSD2 loss correlates to higher tumor grades of NSCLC. Clinically, NSCLC patients expressing high FCHSD2 exhibit elevated survival, whereas patients with high Rab7 expression display decreased survival rates. Our study provides new insight into the molecular nexus for crosstalk between oncogenic signaling and RTK trafficking that controls cancer progression.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Transporte/metabolismo , Endocitose , Neoplasias Pulmonares/patologia , Sistema de Sinalização das MAP Quinases , Proteínas de Membrana/metabolismo , Oncogenes , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Linhagem Celular Tumoral , Progressão da Doença , Endossomos/metabolismo , Receptores ErbB/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pulmonares/enzimologia , Transporte Proteico , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptores da Transferrina/metabolismo , Regulação para Cima , Proteínas rab de Ligação ao GTP/metabolismo
10.
Nat Commun ; 11(1): 2807, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32533074

RESUMO

The nuclear receptor binding SET domain protein 1 (NSD1) is recurrently mutated in human cancers including acute leukemia. We show that NSD1 knockdown alters erythroid clonogenic growth of human CD34+ hematopoietic cells. Ablation of Nsd1 in the hematopoietic system of mice induces a transplantable erythroleukemia. In vitro differentiation of Nsd1-/- erythroblasts is majorly impaired despite abundant expression of GATA1, the transcriptional master regulator of erythropoiesis, and associated with an impaired activation of GATA1-induced targets. Retroviral expression of wildtype NSD1, but not a catalytically-inactive NSD1N1918Q SET-domain mutant induces terminal maturation of Nsd1-/- erythroblasts. Despite similar GATA1 protein levels, exogenous NSD1 but not NSDN1918Q significantly increases the occupancy of GATA1 at target genes and their expression. Notably, exogenous NSD1 reduces the association of GATA1 with the co-repressor SKI, and knockdown of SKI induces differentiation of Nsd1-/- erythroblasts. Collectively, we identify the NSD1 methyltransferase as a regulator of GATA1-controlled erythroid differentiation and leukemogenesis.


Assuntos
Diferenciação Celular , Células Eritroides/metabolismo , Células Eritroides/patologia , Fator de Transcrição GATA1/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Leucemia Eritroblástica Aguda/metabolismo , Leucemia Eritroblástica Aguda/patologia , Adulto , Animais , Antígenos CD/metabolismo , Antígenos CD34/metabolismo , Linhagem Celular Tumoral , Linhagem da Célula , Cromatina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Eritroblastos/metabolismo , Fator de Transcrição GATA1/genética , Regulação Leucêmica da Expressão Gênica , Técnicas de Silenciamento de Genes , Hematopoese , Histona-Lisina N-Metiltransferase/genética , Humanos , Estimativa de Kaplan-Meier , Leucemia Eritroblástica Aguda/genética , Masculino , Camundongos , Ligação Proteica , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores da Transferrina/metabolismo
11.
Nat Cell Biol ; 22(8): 927-933, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32541877

RESUMO

Coat proteins have a central role in vesicular transport by binding to cargoes for their sorting into intracellular pathways. Cargo recognition is mediated by components of the coat complex known as adaptor proteins1-3. We previously showed that Arf-GAP with coil-coil, ANK repeat and PH domain-containing protein 1 (ACAP1) functions as an adaptor for a clathrin coat complex that has a function in endocytic recycling4-6. Here, we show that the protein kinase Akt acts as a co-adaptor in this complex, and is needed in conjunction with ACAP1 to bind to cargo proteins to promote their recycling. In addition to advancing the understanding of endocytic recycling, we uncover a fundamentally different function in which a kinase acts, as Akt in this case is an effector rather than a regulator in a cellular event.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Clatrina/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células HEK293 , Células HeLa , Humanos , Integrinas/metabolismo , Ligação Proteica , Receptores da Transferrina/metabolismo
12.
Exp Hematol ; 86: 53-66.e1, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32450207

RESUMO

Red blood cells are generated daily to replenish dying cells and maintain erythrocyte homeostasis. Erythropoiesis is driven by erythropoietin and supported by specialized red pulp macrophages that facilitate enucleation. Here we show that the leukocyte-specific tyrosine phosphatase CD45 is downregulated in late erythroid development, yet it regulates the CD71+TER119+ progenitor pool, which includes the Pro E, Ery A, and Ery B populations. The CD71+TER119+ progenitors are a major splenic population in neonates required for extramedullary erythropoiesis, to meet the high demand for red blood cells during growth. This population decreases as the mice mature, but this was not the case in CD45-deficient mice, which maintained a high level of these progenitors in the spleen into adulthood. Despite these increased erythroid progenitors, CD45-deficient mice had normal numbers of mature red blood cells. This was attributed to the increased proliferation of the Pro E and Ery A populations and the increased apoptosis of the CD71+TER119+ population, as well as an increased turnover of circulating red blood cells. The expansion of the CD71+TER119+ population in the absence of CD45 was attributed to increased numbers of red pulp macrophages producing erythropoietin in the spleen. Thus, CD45 regulates extramedullary erythropoiesis in the spleen.


Assuntos
Antígenos CD/metabolismo , Células Precursoras Eritroides/metabolismo , Eritropoese , Hematopoese Extramedular , Antígenos Comuns de Leucócito/metabolismo , Receptores da Transferrina/metabolismo , Animais , Antígenos CD/genética , Células Precursoras Eritroides/citologia , Antígenos Comuns de Leucócito/genética , Camundongos , Camundongos Knockout , Receptores da Transferrina/genética , Baço/citologia , Baço/metabolismo
13.
Mol Immunol ; 121: 1-6, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32135400

RESUMO

The transglutaminase 2 (TG2) is one of the enigmatic enzymes with important functional diversity. It plays an important role in several pathologies such as celiac disease (CD). In patients with active CD, the abnormal retrotranscytosis of IgA/gliadin complexes is mediated by Transferrin Receptor 1 (TfR1). This triad association takes also place in IgA nephropathy (IgA-N). IgA-N is characterized by the formation of nephrotoxic complexes of IgA1 and soluble CD89 (sCD89). These complexes are abnormally deposited in the kidney. Using a humanized mouse model of IgA-N (α1KI-CD89Tg), we showed that IgA1-sCD89 complexes engender mesangial cell activation and proliferation with TfR1 and TG2 up-regulation, associated with IgA-N features. This TG2-TfR1 interaction enhances mesangial IgA1 deposition promoting inflammation. Humanized α1KI-CD89Tg mice deficient for TG2 show a decrease in TfR1 expression in kidney leading to reduced IgA1-sCD89 deposits and an improvement in IgA-N features. Moreover, TG2 is active and overexpressed in the intestine of IgA-N mice and gliadin participates to this renal pathology. In kidney as in intestine, the TG2 has a crucial role in the cooperation between TfR1-IgA and a central role in the pathogenic amplification.


Assuntos
Antígenos CD/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Gliadina/imunologia , Glomerulonefrite por IGA/imunologia , Imunoglobulina A/metabolismo , Receptores da Transferrina/metabolismo , Transglutaminases/metabolismo , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Doença Celíaca/imunologia , Doença Celíaca/patologia , Modelos Animais de Doenças , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/imunologia , Gliadina/metabolismo , Humanos , Imunoglobulina A/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Células Mesangiais/imunologia , Células Mesangiais/patologia , Camundongos , Camundongos Transgênicos , Receptores Fc/genética , Receptores Fc/imunologia , Receptores Fc/metabolismo , Receptores da Transferrina/imunologia , Transglutaminases/genética , Transglutaminases/imunologia , Regulação para Cima/imunologia
14.
Mol Cell Biochem ; 468(1-2): 121-128, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32185675

RESUMO

Hepcidin is the master regulator of systemic iron homeostasis and its dysregulation is observed in several chronic liver diseases. Unlike the extracellular iron-sensing mechanisms, the intracellular iron-sensing mechanisms in the hepatocytes that lead to hepcidin induction and secretion are incompletely understood. Here, we aimed to understand the direct role of intracellular iron-loading on hepcidin mRNA and peptide secretion using our previously characterised recombinant HepG2 cells that over-express the cell-surface iron-importer protein transferrin receptor-1. Gene expression of hepcidin (HAMP) was determined by real-time PCR. Intracellular iron levels and secreted hepcidin peptide levels were measured by ferrozine assay and immunoassay, respectively. These measurements were compared in the recombinant and wild-type HepG2 cells under basal conditions at 30 min, 2 h, 4 h and 24 h. Data showed that in the recombinant cells, intracellular iron content was higher than wild-type cells at 30 min (3.1-fold, p < 0.01), 2 h (4.6-fold, p < 0.01), 4 h (4.6-fold, p < 0.01) and 24 h (1.9-fold, p < 0.01). Hepcidin (HAMP) mRNA expression was higher than wild-type cells at 30 min (5.9-fold; p = 0.05) and 24 h (6.1-fold; p < 0.03), but at 4 h, the expression was lower than that in wild-type cells (p < 0.05). However, hepcidin secretion levels in the recombinant cells were similar to those in wild-type cells at all time-points, except at 4 h, when the level was lower than wild-type cells (p < 0.01). High intracellular iron in recombinant HepG2 cells did not proportionally increase hepcidin peptide secretion. This suggests a limited role of elevated intracellular iron in hepcidin secretion.


Assuntos
Antígenos CD/metabolismo , Hepatócitos/metabolismo , Hepcidinas/metabolismo , Ferro/metabolismo , Receptores da Transferrina/metabolismo , Antígenos CD/genética , Expressão Gênica/genética , Células Hep G2 , Hepcidinas/genética , Homeostase/genética , Humanos , Receptores da Transferrina/genética , Proteínas Recombinantes
15.
Life Sci ; 250: 117573, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32209423

RESUMO

Chronic intermittent hypoxia (CIH) is a consequence of obstructive sleep apnea (OSA), which increases reactive oxygen species (ROS) generation, resulting in oxidative damage and neurocognitive impairment. This study was designed to determine whether abnormal iron metabolism occurs in the brain under conditions of CIH and whether Huperzine A (HuA) could improve abnormal iron metabolism and neurological damage. The mouse model of CIH was established by reducing the percentage of inspired O2 (FiO2) from 21% to 9% 20 times/h for 8 h/day, and Huperzine A (HuA, 0.1 mg/kg, i.p.) was administered during CIH exposure for 21 days. HuA significantly improved cognitive impairment and neuronal damage in the hippocampus of CIH mice via increasing the ratio of Bcl-2/Bax and inhibiting caspase-3 cleavage. HuA considerably decreased ROS levels by downregulating the high levels of NADPH oxidase (NOX 2, NOX 4) mediated by CIH. There was an overload of iron, which was characterized by high levels of ferritin (FTL and FTH) and transferrin receptor 1 (TfR1) and low levels of ferroportin 1 (FPN1) in the hippocampus of CIH mice. Decreased levels of TfR1 and FTL proteins observed in HuA treated CIH group, could reduce iron overload in hippocampus. HuA increased PSD 95 protein expression, CREB activation and BDNF protein expression to protect against synaptic plasticity impairment induced by CIH. HuA acts as an effective iron chelator to attenuate apoptosis, oxidative stress and synaptic plasticity mediated by CIH.


Assuntos
Alcaloides/uso terapêutico , Transtornos Cognitivos/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Hipóxia/patologia , Sobrecarga de Ferro/tratamento farmacológico , Sesquiterpenos/uso terapêutico , Animais , Apoptose , Comportamento Animal , Caspase 3/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Modelos Animais de Doenças , Ferritinas/metabolismo , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Plasticidade Neuronal , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo , Oxigênio/metabolismo , Espécies Reativas de Oxigênio , Receptores da Transferrina/metabolismo
16.
PLoS Negl Trop Dis ; 14(2): e0007991, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32023254

RESUMO

BACKGROUND: During infections involving intracellular pathogens, iron performs a double-edged function by providing the pathogen with nutrients, but also boosts the host's antimicrobial arsenal. Although the role of iron has been described in visceral leishmaniasis, information regarding its status in the dermal sequel, Post Kala-azar Dermal Leishmaniasis (PKDL) remains limited. Accordingly, this study aimed to establish the status of iron within monocytes/macrophages of PKDL cases. METHODOLOGY/PRINCIPAL FINDINGS: The intramonocytic labile iron pool (LIP), status of CD163 (hemoglobin-haptoglobin scavenging receptor) and CD71 (transferrin receptor, Tfr) were evaluated within CD14+ monocytes by flow cytometry, and soluble CD163 by ELISA. At the lesional sites, Fe3+ status was evaluated by Prussian blue staining, parasite load by qPCR, while the mRNA expression of Tfr (TfR1/CD71), CD163, divalent metal transporter-1 (DMT-1), Lipocalin-2 (Lcn-2), Heme-oxygenase-1 (HO-1), Ferritin, Natural resistance-associated macrophage protein (NRAMP-1) and Ferroportin (Fpn-1) was evaluated by droplet digital PCR. Circulating monocytes demonstrated elevated levels of CD71, CD163 and soluble CD163, which corroborated with an enhanced lesional mRNA expression of TfR, CD163, DMT1 and Lcn-2. Additionally, the LIP was raised along with an elevated mRNA expression of ferritin and HO-1, as also iron exporters NRAMP-1 and Fpn-1. CONCLUSIONS/SIGNIFICANCE: In monocytes/macrophages of PKDL cases, enhancement of the iron influx gateways (TfR, CD163, DMT-1 and Lcn-2) possibly accounted for the enhanced LIP. However, enhancement of the iron exporters (NRAMP-1 and Fpn-1) defied the classical Ferritinlow/Ferroportinhigh phenotype of alternatively activated macrophages. The creation of such a pro-parasitic environment suggests incorporation of chemotherapeutic strategies wherein the availability of iron to the parasite can be restricted.


Assuntos
Ferro/metabolismo , Leishmaniose Cutânea/metabolismo , Adolescente , Adulto , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/genética , Antígenos de Diferenciação Mielomonocítica/metabolismo , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Feminino , Humanos , Índia , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/fisiologia , Leishmaniose Cutânea/parasitologia , Lipocalina-2/genética , Lipocalina-2/metabolismo , Macrófagos/metabolismo , Masculino , Monócitos/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo , Adulto Jovem
17.
Arch Biochem Biophys ; 682: 108302, 2020 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-32057758

RESUMO

There is currently no effective treatment for neurological impairment caused by traumatic brain injury (TBI). It has been reported that excessive iron production in the brain may be a key factor in neurological impairment. In the present study, we investigated the effects of minocycline, a semi-synthetic tetracycline antibiotic, against TBI-induced neurological impairment and explored its underlying mechanism. Neurological impairment was assessed by foot-fault test, cylinder test, wire hang test, and Morris water maze. Nissl staining was performed to evaluate cell viability in the brain. The iron concentrations in cerebrospinal fluid (CSF), serum, and brain tissues were examined. The Fe2+- and Fe3+- chelating activity of minocycline was measured. Finally, the expression levels of important iron metabolism proteins ferritin, transferrin receptor 1 (TfR1), divalent metal transporter 1 (DMT1), ferroportin 1 (FPN1), and hepcidin in the hippocampus and cortex were measured by Western blot analysis. The results indicate that minocycline significantly attenuated the neurological impairment caused by TBI and increased neuronal viability. Minocycline showed a Fe2+- and Fe3+- chelating activity in vitro and reduced the iron concentration in CSF and brain tissues (cortex and hippocampus). Minocycline also inhibited the overexpression of ferritin and TfR1, but did not affect the expression of DMT1. Minocycline restored the expression of FPN1 by decreasing the expression of hepcidin. In conclusion, minocycline may attenuate neurological impairment caused by TBI and regulate iron metabolism.


Assuntos
Lesões Encefálicas Traumáticas/tratamento farmacológico , Ferro/metabolismo , Minociclina/uso terapêutico , Doenças do Sistema Nervoso/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Encéfalo/metabolismo , Lesões Encefálicas Traumáticas/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Córtex Cerebral/metabolismo , Quelantes/farmacologia , Modelos Animais de Doenças , Ferritinas/metabolismo , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto , Doenças do Sistema Nervoso/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores da Transferrina/metabolismo , Tetraciclina/farmacologia
18.
Sci Rep ; 10(1): 2725, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-32066785

RESUMO

Superparamagnetic iron oxide nanoparticles (SPIONs) have been investigated for wide variety of applications. Their unique properties render them highly applicable as MRI contrast agents, in magnetic hyperthermia or targeted drug delivery. SPIONs surface properties affect a whole array of parameters such as: solubility, toxicity, stability, biodistribution etc. Therefore, progress in the field of SPIONs surface functionalization is crucial for further development of therapeutic or diagnostic agents. In this study, SPIONs were synthesized by thermal decomposition of iron (III) acetylacetonate Fe(acac)3 and functionalized with dihexadecyl phosphate (DHP) via phase transfer. Bioactivity of the SPION-DHP was assessed on SW1353 and TCam-2 cancer derived cell lines. The following test were conducted: cytotoxicity and proliferation assay, reactive oxygen species (ROS) assay, SPIONs uptake (via Iron Staining and ICP-MS), expression analysis of the following genes: alkaline phosphatase (ALPL); ferritin light chain (FTL); serine/threonine protein phosphatase 2A (PP2A); protein tyrosine phosphatase non-receptor type 11 (PTPN11); transferrin receptor 1 (TFRC) via RT-qPCR. SPION-DHP nanoparticles were successfully obtained and did not reveal significant cytotoxicity in the range of tested concentrations. ROS generation was elevated, however not correlated with the concentrations. Gene expression profile was slightly altered only in SW1353 cells.


Assuntos
Condrócitos/efeitos dos fármacos , Compostos Férricos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Nanopartículas de Magnetita/química , Organofosfatos/química , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Apoferritinas/genética , Apoferritinas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Condrócitos/citologia , Condrócitos/metabolismo , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Compostos Férricos/química , Humanos , Hidroxibutiratos/química , Pentanonas/química , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo , Succímero/química
19.
J Biol Chem ; 295(8): 2227-2238, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31932305

RESUMO

The transferrin receptor (TfR) of the bloodstream form (BSF) of Trypanosoma brucei is a heterodimer comprising glycosylphosphatidylinositol (GPI)-anchored expression site-associated gene 6 (ESAG6 or E6) and soluble ESAG7. Mature E6 has five N-glycans, consisting of three oligomannose and two unprocessed paucimannose structures. Its GPI anchor is modified by the addition of 4-6 α-galactose residues. TfR binds tomato lectin (TL), specific for N-acetyllactosamine (LacNAc) repeats, and previous studies have shown transport-dependent increases in E6 size consistent with post-glycan processing in the endoplasmic reticulum. Using pulse-chase radiolabeling, peptide-N-glycosidase F treatment, lectin pulldowns, and exoglycosidase treatment, we have now investigated TfR N-glycan and GPI processing. E6 increased ∼5 kDa during maturation, becoming reactive with both TL and Erythrina cristagalli lectin (ECL, terminal LacNAc), indicating synthesis of poly-LacNAc on paucimannose N-glycans. This processing was lost after exoglycosidase treatment and after RNAi-based silencing of TbSTT3A, the oligosaccharyltransferase that transfers paucimannose structures to nascent secretory polypeptides. These results contradict previous structural studies. Minor GPI processing was also observed, consistent with α-galactose addition. However, increasing the spacing between E6 protein and the GPI ω-site (aa 4-7) resulted in extensive post-translational processing of the GPI anchor to a form that was TL/ECL-reactive, suggesting the addition of LacNAc structures, confirmed by identical assays with BiPNHP, a non-N-glycosylated GPI-anchored reporter. We conclude that BSF trypanosomes can modify GPIs by generating structures reminiscent of those present in insect-stage trypanosomes and that steric constraints, not stage-specific expression of glycosyltransferases, regulate GPI processing.


Assuntos
Glicosilfosfatidilinositóis/química , Glicosilfosfatidilinositóis/metabolismo , Trypanosoma brucei brucei/metabolismo , Glicosídeos/metabolismo , Glicosilação , Lectinas/metabolismo , Polissacarídeos/química , Polissacarídeos/metabolismo , Proteínas de Protozoários/metabolismo , Receptores da Transferrina/metabolismo , Especificidade por Substrato
20.
PLoS One ; 15(1): e0226298, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31895934

RESUMO

LZTFL1 participates in immune synapse formation, ciliogenesis, and the localization of ciliary proteins, and knockout of LZTFL1 induces abnormal distribution of heterotetrameric adaptor protein complex-1 (AP-1) in the Lztfl1-knockout mouse photoreceptor cells, suggesting that LZTFL1 is involved in intracellular transport. Here, we demonstrate that in vitro LZTFL1 directly binds to AP-1 and AP-2 and coimmunoprecipitates AP-1 and AP-2 from cell lysates. DxxFxxLxxxR motif of LZTFL1 is essential for these bindings, suggesting LZTFL1 has roles in AP-1 and AP-2-mediated protein trafficking. Since AP-1 and AP-2 are known to be involved in transferrin receptor 1 (TfR1) trafficking, the effect of LZTFL1 on TfR1 recycling was analyzed. TfR1, AP-1 and LZTFL1 from cell lysates could be coimmunoprecipitated. However, pull-down results indicate there is no direct interaction between TfR1 and LZTFL1, suggesting that LZTFL1 interaction with TfR1 is indirect through AP-1. We report the colocalization of LZTFL1 and AP-1, AP-1 and TfR1 as well as LZTFL1 and TfR1 in the perinuclear region (PNR) and the cytoplasm, suggesting a potential complex between LZTFL1, AP-1 and TfR1. The results from the disruption of adaptin recruitment with brefeldin A treatment suggested ADP-ribosylation factor-dependent localization of LZFL1 and AP-1 in the PNR. Knockdown of AP-1 reduces the level of LZTFL1 in the PNR, suggesting that AP-1 plays a role in LZTFL1 trafficking. Knockout of LZTFL1 reduces the cell surface level and the rate of internalization of TfR1, leading to a decrease of transferrin uptake, efflux, and internalization. However, knockout of LZTFL1 did not affect the cell surface levels of epidermal growth factor receptor and cation-independent mannose 6-phosphate receptor, indicating that LZTFL1 specifically regulates the cell surface level of TfR1. These data support a novel role of LZTFL1 in regulating the cell surface TfR1 level by interacting with AP-1 and AP-2.


Assuntos
Complexo 1 de Proteínas Adaptadoras/metabolismo , Complexo 2 de Proteínas Adaptadoras/metabolismo , Antígenos CD/metabolismo , Membrana Celular/metabolismo , Receptores da Transferrina/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/fisiologia , Complexo 1 de Proteínas Adaptadoras/genética , Complexo 2 de Proteínas Adaptadoras/genética , Animais , Antígenos CD/genética , Movimento Celular , Endocitose , Células HeLa , Humanos , Camundongos Knockout , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico , Receptores da Transferrina/genética , Fatores de Transcrição/genética
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