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1.
MAbs ; 14(1): 2057269, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35388745

RESUMO

Glioblastoma (GBM) is a common and aggressive brain cancer that accounts for 60% of adult brain tumors. Anti-angiogenesis therapy is an attractive option due to the high vasculature density of GBM. However, the best-known anti-angiogenic therapeutics, bevacizumab, and aflibercept, have failed to show significant benefits in GBM patients. One of the reasons is the limited brain penetration of antibody-based therapies due to existence of the blood-brain barrier (BBB), which is further strengthened by the blood vessel normalization effects induced by anti-angiogenic therapies. To investigate if increased drug concentration in the brain by transferrin receptor (TfR)-mediated delivery across the BBB can enhance efficacy of anti-angiogenic antibody therapies, we first identified an antibody that binds to the apical domain of the mouse TfR and does not compete with the natural ligand transferrin (Tf) binding to TfR. Then, we engineered two bispecific antibodies fusing a vascular endothelial growth factor (VEGF)-Trap with the TfR-targeting antibody. Characterization of the two bispecific formats using multiple in vitro assays, which include endocytosis, cell surface and whole-cell TfR levels, human umbilical vein endothelial cell growth inhibition, and binding affinity, demonstrated that the VEGF-Trap fused with a monovalent αTfR (VEGF-Trap/moAb4) has desirable endocytosis without the induction of TfR degradation. Peripherally administered VEGF-Trap/moAb4 improved the brain concentration of VEGF-Trap by more than 10-fold in mice. The distribution of VEGF-Trap/moAb4 was validated to be in the brain parenchyma, indicating the molecule was not trapped inside the vasculature. Moreover, improved VEGF-Trap brain distribution significantly inhibited the angiogenesis of U-87 MG GBM tumors in a mouse model.


Assuntos
Anticorpos Biespecíficos , Glioblastoma , Inibidores da Angiogênese/farmacologia , Animais , Anticorpos Biespecíficos/metabolismo , Glioblastoma/metabolismo , Humanos , Camundongos , Receptores da Transferrina , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Recombinantes de Fusão , Transferrina/metabolismo , Fator A de Crescimento do Endotélio Vascular
2.
Langmuir ; 38(18): 5603-5616, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35446569

RESUMO

Nanoparticle-based delivery of therapeutics to the brain has had limited clinical impact due to challenges crossing the blood-brain barrier (BBB). Certain cells, such as monocytes, possess the ability to migrate across the BBB, making them attractive candidates for cell-based brain delivery strategies. In this work, we explore nanoparticle design parameters that impact both monocyte association and monocyte-mediated BBB transport. We use electrohydrodynamic jetting to prepare nanoparticles of varying sizes, compositions, and elasticity to address their impact on uptake by THP-1 monocytes and permeation across the BBB. An in vitro human BBB model is developed using human cerebral microvascular endothelial cells (hCMEC/D3) for the assessment of migration. We compare monocyte uptake of both polymeric and synthetic protein nanoparticles (SPNPs) of various sizes, as well as their effect on cell migration. SPNPs (human serum albumin/HSA or human transferrin/TF) are shown to promote increased monocyte-mediated transport across the BBB over polymeric nanoparticles. TF SPNPs (200 nm) associate readily, with an average uptake of 138 particles/cell. Nanoparticle loading is shown to influence the migration of THP-1 monocytes. The migration of monocytes loaded with 200 nm TF and 200 nm HSA SPNPs was 2.3-fold and 2.1-fold higher than that of an untreated control. RNA-seq analysis after TF SPNP treatment suggests that the upregulation of several migration genes may be implicated in increased monocyte migration (ex. integrin subunits α M and α L). Integrin ß 2 chain combines with either integrin subunit α M chain or integrin subunit α L chain to form macrophage antigen 1 and lymphocyte function-associated antigen 1 integrins. Both products play a pivotal role in the transendothelial migration cascade. Our findings highlight the potential of SPNPs as drug and/or gene delivery platforms for monocyte-mediated BBB transport, especially where conventional polymer nanoparticles are ineffective or otherwise not desirable.


Assuntos
Monócitos , Nanopartículas , Células Endoteliais/metabolismo , Humanos , Integrinas/metabolismo , Migração Transendotelial e Transepitelial , Transferrina/metabolismo
3.
PLoS One ; 17(3): e0264523, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35245324

RESUMO

BACKGROUND: Iron metabolism is crucial to maintain optimal physiological homeostasis of every organism and any alteration of the iron concentration (i.e. deficit or excess) can have adverse consequences. Transferrins are glycoproteins that play important role in iron transportation and have been widely characterized in vertebrates and insects, but poorly studied in blood-feeding mosquitoes. RESULTS: We characterized a 2102 bp long transcript AcTrf1a with complete CDS of 1872bp, and 226bp UTR region, encoding putative transferrin homolog protein from mosquito An. culicifacies. A detailed in silico analysis predicts AcTrf1a encodes 624 amino acid (aa) long polypeptide that carries transferrin domain. AcTrf1a also showed a putative N-linked glycosylation site, a characteristic feature of most of the mammalian transferrins and certain non-blood feeding insects. Structure modelling prediction confirms the presence of an iron-binding site at the N-terminal lobe of the transferrin. Our spatial and temporal expression analysis under altered pathophysiological conditions showed that AcTrf1a is abundantly expressed in the fat-body, ovary, and its response is significantly altered (enhanced) after blood meal uptake, and exogenous bacterial challenge. Additionally, non-heme iron supplementation of FeCl3 at 1 mM concentration not only augmented the AcTrf1a transcript expression in fat-body but also enhanced the reproductive fecundity of gravid adult female mosquitoes. RNAi-mediated knockdown of AcTrf1a causes a significant reduction in fecundity, confirming the important role of transferrin in oocyte maturation. CONCLUSION: All together our results advocate that detailed characterization of newly identified AcTrf1a transcript may help to select it as a unique target to impair the mosquito reproductive outcome.


Assuntos
Anopheles , Transferrina , Animais , Anopheles/fisiologia , Feminino , Insetos/metabolismo , Ferro/metabolismo , Mamíferos/metabolismo , Transferrina/metabolismo , Transferrinas/metabolismo
4.
J Investig Med ; 70(4): 934-938, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35292508

RESUMO

Iron metabolism is tightly linked to infectious and inflammatory signals through hepcidin synthesis. To date, iron homeostasis during SARS-CoV-2 infection has not yet been described. The aim of this study is to characterize the hepcidin and erythroid regulators (growth differentiation factor 15 (GDF-15) and erythroferrone (ERFE)) by measuring concentrations in plasma in context of COVID-19 disease.We performed a single-center observational study of patients with COVID-19 to evaluate concentrations of main regulatory proteins involved in iron homeostasis, namely: hepcidin, ERFE and GDF-15. SARS-CoV-2 infection (COVID-19+) was defined by a positive RT-PCR. Sixteen patients with COVID-19+ were gender-matched and age-matched to 16 patients with a sepsis unrelated to SARS-CoV-2 (COVID-19-) and were compared with non-parametric statistic test.Clinical and hematological parameters, plasma iron, transferrin, transferrin saturation, ferritin, soluble transferrin receptor and C reactive protein were not statistically different between both groups. Median plasma hepcidin concentrations were higher in the COVID-19+ group (44.1 (IQR 16.55-70.48) vs 14.2 (IQR 5.95-18.98) nmol/L, p=0.003), while median ERFE and GDF-15 concentrations were lower in the COVID-19+ group (0.16 (IQR 0.01-0.73) vs 0.89 (IQR 0.19-3.82) ng/mL, p=0.035; 2003 (IQR 1355-2447) vs 4713 (IQR 2082-7774) pg/mL, p=0015), respectively) compared with the COVID-19- group.This is the first study reporting lower ERFE and GDF-15 median concentrations in patients with COVID-19+ compared with patients with COVID-19-, associated with an increased median concentration of hepcidin in the COVID-19+ group compared with COVID19- group.


Assuntos
COVID-19 , Hepcidinas , COVID-19/metabolismo , Fator 15 de Diferenciação de Crescimento , Hepcidinas/metabolismo , Humanos , Ferro/metabolismo , SARS-CoV-2 , Transferrina/metabolismo
5.
Nat Commun ; 13(1): 1586, 2022 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-35332118

RESUMO

Post-translational modifications diversify protein functions and dynamically coordinate their signalling networks, influencing most aspects of cell physiology. Nevertheless, their genetic regulation or influence on complex traits is not fully understood. Here, we compare the genetic regulation of the same PTM of two proteins - glycosylation of transferrin and immunoglobulin G (IgG). By performing genome-wide association analysis of transferrin glycosylation, we identify 10 significantly associated loci, 9 of which were not reported previously. Comparing these with IgG glycosylation-associated genes, we note protein-specific associations with genes encoding glycosylation enzymes (transferrin - MGAT5, ST3GAL4, B3GAT1; IgG - MGAT3, ST6GAL1), as well as shared associations (FUT6, FUT8). Colocalisation analyses of the latter suggest that different causal variants in the FUT genes regulate fucosylation of the two proteins. Glycosylation of these proteins is thus genetically regulated by both shared and protein-specific mechanisms.


Assuntos
Estudo de Associação Genômica Ampla , Transferrina , Glicosilação , Imunoglobulina G/metabolismo , Processamento de Proteína Pós-Traducional , Transferrina/genética , Transferrina/metabolismo
6.
Molecules ; 27(6)2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35335148

RESUMO

In healthy individuals, virtually all blood plasma iron is bound by transferrin. However, in several diseases and clinical conditions, hazardous non-transferrin-bound iron (NTBI) species occur. NTBI represents a potentially toxic iron form, being a direct cause of oxidative stress in the circulating compartment and tissue iron loading. The accumulation of these species can cause cellular damage in several organs, namely, the liver, spleen, and heart. Despite its pathophysiological relevance, the chemical nature of NTBI remains elusive. This has precluded its use as a clinical biochemical marker and the development of targeted therapies. Herein, we make a critical assessment of the current knowledge of NTBI speciation. The currently accepted hypotheses suggest that NTBI is mostly iron bound to citric acid and iron bound to serum albumin, but the chemistry of this system remains fuzzy. We explore the complex chemistry of iron complexation by citric acid and its implications towards NTBI reactivity. Further, the ability of albumin to bind iron is revised and the role of protein post-translational modifications on iron binding is discussed. The characterization of the NTBI species structure may be the starting point for the development of a standardized analytical assay, the better understanding of these species' reactivity or the identification of NTBI uptake mechanisms by different cell types, and finally, to the development of new therapies.


Assuntos
Sobrecarga de Ferro , Transferrina , Transporte Biológico , Humanos , Ferro/química , Sobrecarga de Ferro/metabolismo , Fígado/metabolismo , Transferrina/metabolismo
7.
Sci Rep ; 12(1): 2721, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35177695

RESUMO

Inflammatory states are associated with anemia of chronic disease and acute infection. Hepcidin, a regulator of iron metabolism, is involved in iron pathophysiology during inflammation. We investigated biochemical characteristics in children with anemia from different causes. Four patient groups (n = 38; mean age: 12.44 ± 4.35 years) were studied: (1) inflammatory bowel disease (IBD, 10 patients); (2) iron deficiency anemia (IDA, 12); (3) celiac disease (CD, 8); (4) acute infection (AI, 8). Laboratory measurements were evaluated at diagnosis: blood count, serum iron, transferrin, ferritin, vitamin B12, folic acid, CRP, erythropoietin, hepcidin and soluble transferrin receptor (sTfR). IDA patients had the lowest Hgb (6.9 ± 1.7 g/dL), MCV (63.2 ± 7.2 fL), iron (16.8 ± 13.5 µg/dL), ferritin (4.5 ± 4.5 ng/mL) and hepcidin (3.1 ± 0.8 ng/mL) values, and the highest transferrin and sTfR values. AI patients had the highest ferritin (156.2 ± 124.5 ng/mL), CRP (144.6 ± 94 mg/L) and hepcidin (74.67 ± 12.3 ng/ml) values. Overall, hepcidin levels correlated with CRP and with ferritin (r = 0.83 and 0.85, respectively). Elucidating specific etiology-related biochemical profiles in pediatric patients with anemia from different causes using a combination of laboratory biomarkers, including hepcidin, can help physicians treat the anemia.


Assuntos
Anemia/sangue , Anemia/diagnóstico , Adolescente , Anemia/complicações , Anemia Ferropriva/sangue , Anemia Ferropriva/complicações , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Doença Celíaca/sangue , Doença Celíaca/complicações , Criança , Eritropoetina/sangue , Feminino , Ferritinas/sangue , Ácido Fólico/sangue , Hemoglobinas/metabolismo , Hepcidinas/metabolismo , Humanos , Infecções/sangue , Infecções/complicações , Doenças Inflamatórias Intestinais/sangue , Doenças Inflamatórias Intestinais/complicações , Ferro/análise , Ferro/sangue , Masculino , Receptores da Transferrina/sangue , Transferrina/metabolismo , Vitamina B 12/sangue
8.
Int J Mol Sci ; 23(3)2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35163840

RESUMO

Pathogenic TMPRSS6 variants impairing matriptase-2 function result in inappropriately high hepcidin levels relative to body iron status, leading to iron refractory iron deficiency anemia (IRIDA). As diagnosing IRIDA can be challenging due to its genotypical and phenotypical heterogeneity, we assessed the transferrin saturation (TSAT)/hepcidin ratio to distinguish IRIDA from multi-causal iron deficiency anemia (IDA). We included 20 IRIDA patients from a registry for rare inherited iron disorders and then enrolled 39 controls with IDA due to other causes. Plasma hepcidin-25 levels were measured by standardized isotope dilution mass spectrometry. IDA controls had not received iron therapy in the last 3 months and C-reactive protein levels were <10.0 mg/L. IRIDA patients had significantly lower TSAT/hepcidin ratios compared to IDA controls, median 0.6%/nM (interquartile range, IQR, 0.4-1.1%/nM) and 16.7%/nM (IQR, 12.0-24.0%/nM), respectively. The area under the curve for the TSAT/hepcidin ratio was 1.000 with 100% sensitivity and specificity (95% confidence intervals 84-100% and 91-100%, respectively) at an optimal cut-off point of 5.6%/nM. The TSAT/hepcidin ratio shows excellent performance in discriminating IRIDA from TMPRSS6-unrelated IDA early in the diagnostic work-up of IDA provided that recent iron therapy and moderate-to-severe inflammation are absent. These observations warrant further exploration in a broader IDA population.


Assuntos
Anemia Ferropriva/sangue , Hepcidinas/sangue , Proteínas de Membrana/genética , Serina Endopeptidases/genética , Transferrina/metabolismo , Adolescente , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/genética , Área Sob a Curva , Proteína C-Reativa/metabolismo , Criança , Humanos , Masculino , Sensibilidade e Especificidade , Adulto Jovem
9.
Int J Mol Sci ; 23(3)2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35163558

RESUMO

A subpopulation of neurons is less vulnerable against iron-induced oxidative stress and neurodegeneration. A key feature of these neurons is a special extracellular matrix composition that forms a perineuronal net (PN). The PN has a high affinity to iron, which suggests an adapted iron sequestration and metabolism of the ensheathed neurons. Highly active, fast-firing neurons-which are often ensheathed by a PN-have a particular high metabolic demand, and therefore may have a higher need in iron. We hypothesize that PN-ensheathed neurons have a higher intracellular iron concentration and increased levels of iron proteins. Thus, analyses of cellular and regional iron and the iron proteins transferrin (Tf), Tf receptor 1 (TfR), ferritin H/L (FtH/FtL), metal transport protein 1 (MTP1 aka ferroportin), and divalent metal transporter 1 (DMT1) were performed on Wistar rats in the parietal cortex (PC), subiculum (SUB), red nucleus (RN), and substantia nigra (SNpr/SNpc). Neurons with a PN (PN+) have higher iron concentrations than neurons without a PN: PC 0.69 mM vs. 0.51 mM, SUB 0.84 mM vs. 0.69 mM, SN 0.71 mM vs. 0.63 mM (SNpr)/0.45 mM (SNpc). Intracellular Tf, TfR and MTP1 contents of PN+ neurons were consistently increased. The iron concentration of the PN itself is not increased. We also determined the percentage of PN+ neurons: PC 4%, SUB 5%, SNpr 45%, RN 86%. We conclude that PN+ neurons constitute a subpopulation of resilient pacemaker neurons characterized by a bustling iron metabolism and outstanding iron handling capabilities. These properties could contribute to the low vulnerability of PN+ neurons against iron-induced oxidative stress and degeneration.


Assuntos
Proteínas de Ligação ao Ferro/metabolismo , Ferro/metabolismo , Nervos Periféricos/metabolismo , Animais , Apoferritinas/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Metabolismo Energético , Regulação da Expressão Gênica , Masculino , Ratos , Ratos Wistar , Receptores da Transferrina/metabolismo , Transferrina/metabolismo
10.
Infect Dis (Lond) ; 54(6): 403-409, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35057702

RESUMO

BACKGROUND: Virtually all living organisms, including microbes and humans, depend on iron to survive and grow. During an infection, the plasma level of iron and several iron-related proteins change substantially. We hypothesized that iron and iron-related proteins could predict short- and long-term outcomes in community-acquired pneumonia. METHODS: Blood samples from a prospective cohort of 267 in-patients with community-acquired pneumonia were analysed for hepcidin, ferritin, iron, transferrin, transferrin saturation, and soluble transferrin receptor at admission and 6-weeks post-discharge. Adverse short-term outcome was defined as admission to intensive care unit or death within 30 days, and long-term outcome was assessed as 5-year overall mortality. Logistic regression, Kaplan Meier survival curves, and Cox regression models with cut-offs at median for the potential biomarkers were used for statistical evaluation. RESULTS: Low admission levels of hepcidin predicted 5-year overall mortality, independently of age, sex, comorbid conditions, and anaemia. Low levels of ferritin at admission as well as low levels of iron and transferrin saturation and high levels of soluble transferrin receptor at the 6-week follow-up were predictors of 5-year overall mortality in univariable, but not in multivariable analyses. Neither of these potential biomarkers predicted adverse short-term outcomes. CONCLUSIONS: In hospitalized patients with community-acquired pneumonia, low levels of hepcidin at admission predicted 5-year overall mortality, but not short-term adverse outcome.


Assuntos
Infecções Comunitárias Adquiridas , Pneumonia , Assistência ao Convalescente , Biomarcadores , Ferritinas , Hepcidinas/metabolismo , Humanos , Ferro/metabolismo , Alta do Paciente , Estudos Prospectivos , Receptores da Transferrina , Transferrina/análise , Transferrina/metabolismo
11.
Sci Rep ; 12(1): 1297, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35079042

RESUMO

Δ9-tetrahydrocannabinol (Δ9-THC) is known for its antitumor activity and palliative effects. However, its unfavorable physicochemical and biopharmaceutical properties, including low bioavailability, psychotropic side effects and resistance mechanisms associated to dosing make mandatory the development of successful drug delivery systems. In this work, transferring (Tf) surface-modified Δ9-THC-loaded poly(lactide-co-glycolic) nanoparticles (Tf-THC-PLGA NPs) were proposed and evaluated as novel THC-based anticancer therapy. Furthermore, in order to assess the interaction of both the nanocarrier and the loaded drug with cancer cells, a double-fluorescent strategy was applied, including the chemical conjugation of a dye to the nanoparticle polymer along with the encapsulation of either a lipophilic or a hydrophilic dye. Tf-THC PLGA NPs exerted a cell viability decreased down to 17% vs. 88% of plain nanoparticles, while their internalization was significantly slower than plain nanoparticles. Uptake studies in the presence of inhibitors indicated that the nanoparticles were internalized through cholesterol-associated and clathrin-mediated mechanisms. Overall, Tf-modification of PLGA NPs showed to be a highly promising approach for Δ9-THC-based antitumor therapies, potentially maximizing the amount of drug released in a sustained manner at the surface of cells bearing cannabinoid receptors.


Assuntos
Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Neoplasias do Colo/metabolismo , Dronabinol/metabolismo , Dronabinol/farmacologia , Liberação Controlada de Fármacos , Nanopartículas/química , Receptores de Canabinoides/metabolismo , Células CACO-2 , Cápsulas , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/patologia , Humanos , Ligantes , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Receptores da Transferrina/metabolismo , Transferrina/química , Transferrina/metabolismo
12.
Cell Mol Life Sci ; 79(1): 62, 2022 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-35001155

RESUMO

Availability of iron is a key factor in the survival and multiplication of Mycobacterium tuberculosis (M.tb) within host macrophage phagosomes. Despite host cell iron regulatory machineries attempts to deny supply of this essential micronutrient, intraphagosomal M.tb continues to access extracellular iron. In the current study, we report that intracellular M.tb exploits mammalian secreted Glyceraldehyde 3-phosphate dehydrogenase (sGAPDH) for the delivery of host iron carrier proteins lactoferrin (Lf) and transferrin (Tf). Studying the trafficking of iron carriers in infected cells we observed that sGAPDH along with the iron carrier proteins are preferentially internalized into infected cells and trafficked to M.tb containing phagosomes where they are internalized by resident mycobacteria resulting in iron delivery. Collectively our findings provide a new mechanism of iron acquisition by M.tb involving the hijack of host sGAPDH. This may contribute to its successful pathogenesis and provide an option for targeted therapeutic intervention.


Assuntos
Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Ferro/metabolismo , Lactoferrina/metabolismo , Mycobacterium tuberculosis/metabolismo , Transferrina/metabolismo , Animais , Transporte Biológico/fisiologia , Linhagem Celular Tumoral , Humanos , Células L , Camundongos , Camundongos Endogâmicos C57BL , Fagossomos/metabolismo , Células THP-1 , Tuberculose/patologia
13.
Int J Mol Sci ; 23(2)2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-35054798

RESUMO

Despite some progress, the overall survival of patients with glioblastoma (GBM) remains extremely poor. In this context, there is a pressing need to develop innovative therapy strategies for GBM, namely those based on nanomedicine approaches. Towards this goal, we have focused on nanoparticles (AuNP-SP and AuNP-SPTyr8) with a small gold core (ca. 4 nm), carrying DOTA chelators and substance P (SP) peptides. These new SP-containing AuNPs were characterized by a variety of analytical techniques, including TEM and DLS measurements and UV-vis and CD spectroscopy, which proved their high in vitro stability and poor tendency to interact with plasma proteins. Their labeling with diagnostic and therapeutic radionuclides was efficiently performed by DOTA complexation with the trivalent radiometals 67Ga and 177Lu or by electrophilic radioiodination with 125I of the tyrosyl residue in AuNP-SPTyr8. Cellular studies of the resulting radiolabeled AuNPs in NKR1-positive GBM cells (U87, T98G and U373) have shown that the presence of the SP peptides has a crucial and positive impact on their internalization by the tumor cells. Consistently, 177Lu-AuNP-SPTyr8 showed more pronounced radiobiological effects in U373 cells when compared with the non-targeted congener 177Lu-AuNP-TDOTA, as assessed by cell viability and clonogenic assays and corroborated by Monte Carlo microdosimetry simulations.


Assuntos
Glioblastoma/tratamento farmacológico , Ouro/química , Nanopartículas Metálicas/química , Modelos Biológicos , Peptídeos/síntese química , Compostos Radiofarmacêuticos/química , Substância P/síntese química , Linhagem Celular Tumoral , Endocitose , Humanos , Peptídeos/química , Albumina Sérica/metabolismo , Espectrofotometria Ultravioleta , Substância P/química , Transferrina/metabolismo
14.
J Am Coll Cardiol ; 79(4): 341-351, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35086656

RESUMO

BACKGROUND: Guidelines on heart failure (HF) define iron deficiency (ID) as a serum ferritin <100 ng/mL or, when 100-299 ng/mL, a transferrin saturation (TSAT) <20%. Inflammation (common in HF) may hinder interpretation of serum ferritin. OBJECTIVES: This study sought to investigate how different definitions of ID affect its prevalence and relationship to prognosis in ambulatory patients with chronic HF. METHODS: Prevalence, relationship with patients' characteristics, and outcomes of various ID definitions were evaluated among patients with HF referred to a regional clinic (Hull LifeLab) from 2001 to 2019. RESULTS: Of 4,422 patients with HF (median age 75 years [range: 68-82 years], 60% men, 32% with reduced left ventricular ejection fraction), 46% had TSAT <20%, 48% had serum iron ≤13 µmol/L, 57% had serum ferritin <100 ng/mL, and 68% fulfilled current guideline criteria for ID, of whom 35% had a TSAT >20%. Irrespective of definition, ID was more common in women and those with more severe symptoms, anemia, or preserved ejection fraction. TSAT <20% and serum iron ≤13 µmol/L, but not guideline criteria, were associated with higher 5-year mortality (HR: 1.27; 95% CI: 1.14-1.43; P < 0.001; and HR: 1.37; 95% CI: 1.22-1.54; P < 0.001, respectively). Serum ferritin <100 ng/mL tended to be associated with lower mortality (HR: 0.91; 95% CI: 0.81-1.01; P = 0.09). CONCLUSIONS: Different definitions of ID provide discordant results for prevalence and prognosis. Definitions lacking specificity may attenuate the benefits of intravenous iron observed in trials while definitions lacking sensitivity may exclude patients who should receive intravenous iron. Prespecified subgroup analyses of ongoing randomized trials should address this issue.


Assuntos
Insuficiência Cardíaca/complicações , /epidemiologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Doença Crônica , Estudos de Coortes , Feminino , Ferritinas/sangue , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/mortalidade , Humanos , Ferro/sangue , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Prevalência , Prognóstico , Sensibilidade e Especificidade , Volume Sistólico , Transferrina/metabolismo
15.
Basic Clin Pharmacol Toxicol ; 130(1): 182-190, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34591374

RESUMO

BACKGROUND: The aim of this study was to evaluate the quantitative relation between common clinical chemical analyses and ethanol use, measured by a combination of the two alcohol markers phosphatidylethanol (PEth) and carbohydrate-deficient transferrin (CDT). METHODS: Results of PEth and CDT in whole blood and serum, respectively, were included, together with information on 10 different commonly measured clinical chemical analytes, as well as age and sex. PEth was analysed by UPC2 -MS/MS and CDT was measured by capillary electrophoresis. RESULTS: Samples from 4873 patients were included. The strongest relation to alcohol consumption as measured by PEth, when correcting for age and sex, was found for HDL-C (standardized ß = 0.472, p < 0.001), AST (standardized ß = 0.372, p < 0.001), ferritin (standardized ß = 0.332, p < 0.001) and GGT (standardized ß = 0.325, p < 0.001). The relation to PEth was weak for total cholesterol, TG and ALP. No relation was found for Hb and LDL-C. CONCLUSIONS: When using PEth as a marker for alcohol consumption, this study demonstrated the quantitative relation to commonly used test as AST or GGT, but also an important relation to ferritin or HDL-C. In clinical practice, elevated levels of these clinical chemical analytes should initiate further work-up on possibly harmful alcohol use.


Assuntos
Consumo de Bebidas Alcoólicas/sangue , Glicerofosfolipídeos/sangue , Transferrina/análogos & derivados , Adulto , Consumo de Bebidas Alcoólicas/metabolismo , Aspartato Aminotransferases/sangue , Biomarcadores/sangue , HDL-Colesterol/sangue , Feminino , Ferritinas/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem , Transferrina/metabolismo , gama-Glutamiltransferase/sangue
16.
Cancer Epidemiol Biomarkers Prev ; 31(1): 230-235, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34649958

RESUMO

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) has become a major contributor to the rising incidence of hepatocellular carcinoma (HCC) in the United States and other developed countries. Iron, an essential metal primarily stored in hepatocytes, may play a role in the development of NAFLD-related HCC. Epidemiologic data on iron overload without hemochromatosis in relation to HCC are sparse. This study aimed to examine the associations between serum biomarkers of iron and the risk of HCC in patients with NAFLD. METHODS: We identified 18,569 patients with NAFLD using the University of Pittsburgh Medical Center electronic health records from 2004 through 2018. After an average 4.34 years of follow-up, 244 patients developed HCC. Cox proportional hazard regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) of HCC incidence associated with elevated levels of iron biomarkers with adjustment for age, sex, race, body mass index, history of diabetes, and tobacco smoking. RESULTS: The HRs (95% CIs) of HCC for clinically defined elevation of serum iron and transferrin saturation were 2.91 (1.34-6.30) and 2.02 (1.22-3.32), respectively, compared with their respective normal range. No statistically significant association was observed for total iron-binding capacity or serum ferritin with HCC risk. CONCLUSIONS: Elevated levels of serum iron and transferrin saturation were significantly associated with increased risk of HCC among patients with NAFLD without hemochromatosis or other major underlying causes of chronic liver diseases. IMPACT: Clinical surveillance of serum iron level may be a potential strategy to identify patients with NAFLD who are at high risk for HCC.


Assuntos
Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/sangue , Ferro/sangue , Neoplasias Hepáticas/sangue , Hepatopatia Gordurosa não Alcoólica/sangue , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pennsylvania , Estudos Retrospectivos , Risco , Transferrina/metabolismo
18.
Int Urol Nephrol ; 54(5): 1145-1153, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34510284

RESUMO

PURPOSE: Iron is usually administered in hemodialysis patients by parenteral route, as oral absorption is poor due to high hepcidin levels. However, administrations of intravenous iron and iron overload are associated with high oxidative stress and systemic inflammation that can affect patient survival. With this study, we evaluated an alternative type of oral iron for the treatment of anemia in hemodialysis patients. The formulation consists in ferric pyrophosphate covered by phospholipids plus sucrose ester of fatty acid matrix, named sucrosomial iron, whose absorption is not influenced by hepcidin. METHODS: Twenty-four (24) patients undergoing chronic hemodialysis switched iron supplementation from intravenous (ferric gluconate 62.5 mg weekly) to oral (sucrosomial iron, 90 mg weekly in 3 administrations of 30 mg) route for 3 months. Classical anemia, iron metabolism, inflammation and nutritional biomarkers were monitored, as well as biomarkers of oxidative stress, such as protein-bound di-tyrosines, protein carbonylation, advanced oxidation protein products and protein thiols. RESULTS: Over the 3 months, hemoglobin values remained stable, as the values of hematocrit and mean corpuscular volume. In parallel, other anemia parameters dropped, including ferritin, transferrin saturation and serum iron. On the other side, nutritional biomarkers, such as total proteins and transferrin, increased significantly during the time frame. We also observed a significant decrease in white blood cells as well as a non-significant reduction in C-reactive protein and some oxidative stress biomarkers, such as protein carbonyls and di-tyrosines. CONCLUSION: Our study demonstrates that a therapy with sucrosomial iron in hemodialysis patients is safe and can maintain stable hemoglobin levels in a three-month period with a possible beneficial effect on oxidative stress parameters. However, the reduction of ferritin and transferrin saturation suggests that a weekly dosage of 90 mg is not sufficient in hemodialysis patients in the long time to maintain hemoglobin.


Assuntos
Anemia , Eritropoetina , Anemia/etiologia , Biomarcadores/metabolismo , Compostos Férricos , Ferritinas , Hemoglobinas/metabolismo , Hepcidinas , Humanos , Inflamação/etiologia , Ferro/metabolismo , Estresse Oxidativo , Diálise Renal/efeitos adversos , Transferrina/metabolismo
19.
J Neurochem ; 160(3): 356-375, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34837396

RESUMO

Neurodegeneration with brain iron accumulation (NBIA) is a clinically and genetically heterogeneous group of neurodegenerative diseases characterized by the abnormal accumulation of brain iron and the progressive degeneration of the nervous system. One of the recently identified subtypes of NBIA is ß-propeller protein-associated neurodegeneration (BPAN). BPAN is caused by de novo mutations in the WDR45/WIPI4 (WD repeat domain 45) gene. WDR45 is one of the four mammalian homologs of yeast Atg18, a regulator of autophagy. WDR45 deficiency in BPAN patients and animal models may result in defects in autophagic flux. However, how WDR45 deficiency leads to brain iron overload remains unclear. To elucidate the role of WDR45, we generated a WDR45-knockout (KO) SH-SY5Y neuroblastoma cell line using CRISPR-Cas9-mediated genome editing. Using these cells, we demonstrated that the non-TF (transferrin)-bound iron pathway dominantly mediated the accumulation of iron. Moreover, the loss of WDR45 led to defects in ferritinophagy, a form of autophagy that degrades the iron storage protein ferritin. We showed that impaired ferritinophagy contributes to iron accumulation in WDR45-KO cells. Iron accumulation was also detected in the mitochondria, which was accompanied by impaired mitochondrial respiration, elevated reactive oxygen species, and increased cell death. Thus, our study links WDR45 to specific iron acquisition pathways and ferritinophagy. Cover Image for this issue: https://doi.org/10.1111/jnc.15388.


Assuntos
Autofagia/genética , Proteínas de Transporte/genética , Sobrecarga de Ferro/genética , Doenças Neurodegenerativas/genética , Química Encefálica/genética , Morte Celular , Linhagem Celular , Técnicas de Inativação de Genes , Humanos , Ferro/metabolismo , Sobrecarga de Ferro/metabolismo , Mitocôndrias/metabolismo , Doenças Neurodegenerativas/metabolismo , Espécies Reativas de Oxigênio , Transferrina/metabolismo
20.
Arterioscler Thromb Vasc Biol ; 42(1): e10-e26, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34732055

RESUMO

OBJECTIVE: Maturation of megakaryocytes culminates with extensive membrane rearrangements necessary for proplatelet formation. Mechanisms required for proplatelet extension and origin of membranes are still poorly understood. GTPase Rab5 (Ras-related protein in brain 5) regulates endocytic uptake and homotypic fusion of early endosomes and regulates phosphatidylinositol 3-monophosphate production important for binding of effector proteins during early-to-late endosomal/lysosomal maturation. Approach and Results: To investigate the role of Rab5 in megakaryocytes, we expressed GFP (green fluorescent protein)-coupled Rab5 wild type and its point mutants Q79L (active) and N133L (inactive) in primary murine fetal liver-derived megakaryocytes. Active Rab5 Q79L induced the formation of enlarged early endosomes, while inactive Rab5 N133L caused endosomal fragmentation. Consistently, an increased amount of transferrin internalization in Rab5 Q79L was impaired in Rab5 N133L expressing megakaryocytes, when compared with GFP or Rab5 wild type. Moreover, trafficking of GPIbß (glycoprotein Ib subunit beta), a subunit of major megakaryocytes receptor and membrane marker, was found to be mediated by Rab5 activity. While GPIbß was mostly present along the plasma membrane, and within cytoplasmic vesicles in Rab5 wild type megakaryocytes, it accumulated in the majority of Rab5 Q79L enlarged endosomes. Conversely, Rab5 N133L caused mostly GPIbß plasma membrane retention. Furthermore, Rab5 Q79L expression increased incorporation of the membrane dye (PKH26), indicating higher membrane content. Finally, while Rab5 Q79L increased proplatelet production, inactive Rab5 N133L strongly inhibited it and was coupled with a decrease in late endosomes/lysosomes. Localization of GPIbß in enlarged endosomes was phosphatidylinositol 3-monophosphate dependent. CONCLUSIONS: Taken together, our results demonstrate that Rab5-dependent endocytosis plays an important role in megakaryocytes receptor trafficking, membrane formation, and thrombopoiesis.


Assuntos
Plaquetas/enzimologia , Endocitose , Endossomos/enzimologia , Megacariócitos/enzimologia , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Trombopoese , Proteínas rab5 de Ligação ao GTP/metabolismo , Animais , Células Cultivadas , Feminino , Masculino , Camundongos Endogâmicos C57BL , Complexo Glicoproteico GPIb-IX de Plaquetas/genética , Mutação Puntual , Transporte Proteico , Transferrina/metabolismo , Proteínas rab5 de Ligação ao GTP/genética
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