RÉSUMÉ
Iron metabolism plays an important role in insulin resistance, and the triglyceride-glucose (TyG) index has been proposed in recent years as a more accessible and cost-effective marker for insulin resistance. This study aims to evaluate the association between iron metabolism markers, including ferritin (FER), transferrin (TRF), and transferrin receptor (TFR), and the TyG index. A total of 6524 Chinese individuals aged between 18 and 75 years were included in this study. Multivariable linear models were used to investigate the association between FER, TRF, and TFR levels, and the TyG index. Further subgroup analyses stratified by age and sex were also performed. There was a positive association between FER and TRF levels and the TyG index in all 3 multivariable linear regression models, regardless of stratification by sex and age. Additionally, TFR was positively associated with the TyG index among females and those aged ≥45 years, but not among males and those aged <45 years. Our findings reveal a positive association between FER and TRF levels and the TyG index in a Chinese population, while the association between TFR levels and the TyG index showed different patterns depending on age and gender.
Sujet(s)
Marqueurs biologiques , Glycémie , Ferritines , Fer , Enquêtes nutritionnelles , Récepteurs à la transferrine , Transferrine , Triglycéride , Humains , Mâle , Femelle , Adulte d'âge moyen , Adulte , Chine , Études transversales , Triglycéride/sang , Récepteurs à la transferrine/sang , Ferritines/sang , Sujet âgé , Marqueurs biologiques/sang , Transferrine/analyse , Transferrine/métabolisme , Fer/sang , Fer/métabolisme , Adolescent , Glycémie/analyse , Glycémie/métabolisme , Jeune adulte , InsulinorésistanceRÉSUMÉ
The lack of specific biological materials and biomarkers limits our knowledge of the mechanisms underlying intrauterine regulation of iron supply to the fetus. Determining the meconium content of proteins commonly used in the laboratory to assess the transport, storage, and distribution of iron in the body may elucidate their roles in fetal development. Ferritin, transferrin, haptoglobin, ceruloplasmin, lactoferrin, myeloperoxidase (MPO), neutrophil gelatinase-associated lipocalin (NGAL), and calprotectin were determined by ELISA in meconium samples obtained from 122 neonates. There were strong correlations between the meconium concentrations of haptoglobin, transferrin, and NGAL (p < 0.05). Meconium concentrations of ferritin were several-fold higher than the concentrations of the other proteins, with the exception of calprotectin whose concentration was approximately three-fold higher than that of ferritin. Meconium ceruloplasmin concentration significantly correlated with the concentrations of MPO, NGAL, lactoferrin, and calprotectin. Correlations between the meconium concentrations of haptoglobin, transferrin, and NGAL may reflect their collaborative involvement in the storage and transport of iron in the intrauterine environment in line with their recognized biological properties. High meconium concentrations of ferritin may provide information about the demand for iron and its utilization by the fetus. The associations between ceruloplasmin and neutrophil proteins may indicate the involvement of ceruloplasmin in the regulation of neutrophil activity in the intrauterine environment.
Sujet(s)
Céruloplasmine , Haptoglobines , Fer , Lipocaline-2 , Méconium , Humains , Fer/métabolisme , Méconium/métabolisme , Nouveau-né , Céruloplasmine/métabolisme , Femelle , Haptoglobines/métabolisme , Lipocaline-2/métabolisme , Transferrine/métabolisme , Transferrine/analyse , Ferritines/métabolisme , Complexe antigénique L1 leucocytaire/métabolisme , Lactoferrine/métabolisme , Lactoferrine/analyse , Mâle , Myeloperoxidase/métabolisme , Marqueurs biologiques/métabolisme , AdulteRÉSUMÉ
BACKGROUND: The aim of this study was to explore the causal relationship between different serum iron statuses (ferritin, transferrin, transferrin saturation, and serum iron) and the occurrence of estrogen receptor (ER)-positive or ER-negative breast cancer. METHODS: The summary data on serum iron status exposure were gathered from the IEU OpenGWAS Project, the UK Biobank, and other databases. Concurrently, the summary data for ER+ and ER- breast cancer are sourced from the Breast Cancer Association Consortium (BCAC). By examining the causal link between iron status and breast cancer, we deployed five distinct Mendelian randomization (MR) algorithms, namely MR-Egger, inverse variance weighted (IVW), weighted median, simple mode, and MR-PRESSO. To assess heterogeneity and horizontal pleiotropy, Cochran's Q and MR-Egger algorithms were applied, respectively. RESULTS: Elevated ferritin levels are associated with an increased risk of ER-negative breast cancer (OR(IVW) = 1.042, 95% CI (1.005, 1.081), p = 0.025; OR (weighted median) = 1.050, 95% CI (1.001, 1.102), p = 0.046; and OR (MR-PRESSO) = 1.042, 95% CI (1.005, 1.081), p = 0.039). Conversely, an increase in the serum iron level is linked to a reduced risk of ER-negative breast cancer (OR (IVW) = 0.791, 95% CI (0.649, 0.962), p = 0.019; and OR (MR-PRESSO) = 0.791, 95% CI (0.649, 0.962), p = 0.028). However, there is no evidence of a causal relationship between transferrin, transferrin saturation, and ER-negative breast cancer. For ER-positive breast cancer, none of the four different iron statuses demonstrated a causal relationship. CONCLUSIONS: Ferritin is positively correlated with ER-negative breast cancer, while serum iron is negatively associated with ER-negative breast cancer. However, there is no causal relationship between the four iron statuses and ER-positive breast cancer.
Sujet(s)
Tumeurs du sein , Ferritines , Fer , Analyse de randomisation mendélienne , Récepteurs des oestrogènes , Humains , Tumeurs du sein/sang , Tumeurs du sein/génétique , Ferritines/sang , Femelle , Fer/sang , Récepteurs des oestrogènes/métabolisme , Récepteurs des oestrogènes/génétique , Transferrine/analyse , Transferrine/métabolisme , Facteurs de risqueRÉSUMÉ
Alzheimer's disease (AD) and Frontotemporal lobar degeneration (FTLD) represent the most common forms of neurodegenerative dementias with a highly phenotypic variability. Herein, we investigated the role of genetic variants related to the immune system and inflammation as genetic modulators in AD and related dementias. In patients with sporadic AD/FTLD (n = 300) and GRN/C9orf72 mutation carriers (n = 80), we performed a targeted sequencing of 50 genes belonging to the immune system and inflammation, selected based on their high expression in brain regions and low tolerance to genetic variation. The linear regression analyses revealed two genetic variants: (i) the rs1049296 in the transferrin (TF) gene, shown to be significantly associated with age at onset in the sporadic AD group, anticipating the disease onset of 4 years for each SNP allele with respect to the wild-type allele, and (ii) the rs7550295 in the calsyntenin-1 (CLSTN1) gene, which was significantly associated with age at onset in the C9orf72 group, delaying the disease onset of 17 years in patients carrying the SNP allele. In conclusion, our data support the role of genetic variants in iron metabolism (TF) and in the modulation of the calcium signalling/axonal anterograde transport of vesicles (CLSTN1) as genetic modulators in AD and FTLD due to C9orf72 expansions.
Sujet(s)
Âge de début , Maladie d'Alzheimer , Protéine C9orf72 , Dégénérescence lobaire frontotemporale , Humains , Maladie d'Alzheimer/génétique , Protéine C9orf72/génétique , Dégénérescence lobaire frontotemporale/génétique , Femelle , Mâle , Sujet âgé , Adulte d'âge moyen , Expansion de séquence répétée de l'ADN/génétique , Sujet âgé de 80 ans ou plus , Polymorphisme de nucléotide simple , Transferrine/génétique , Transferrine/métabolisme , Prédisposition génétique à une maladie , Variation génétiqueRÉSUMÉ
INTRODUCTION: Worldwide, almost 1.2 million people drive under the influence of alcohol. However, early identification of alcohol use disorder (AUD) in subjects driving under the influence (DUI) of alcohol is seldom achieved. AIM: The aim of our retrospective study is to investigate the presence of AUD in a population of DUI subjects who had their driving license suspended, and if they were following a specific rehabilitation program. METHODS AND RESULTS: 750 subjects were retrospectively enrolled from 2018 to 2021. DSM-V to assess AUD was used. Forty-eight (6.4%) subjects presented a diagnosis of AUD, after one month they showed a statistically significant reduction of carbohydrate-deficient transferrin (CDT) (p<0.0001); however, none were following a program for the treatment of AUD. CONCLUSIONS: This outpatient setting may be considered a place of primary and secondary prevention where DUI subjects with a diagnosis of AUD may be entrusted to a Centre in order to follow rehabilitation treatment.
Sujet(s)
Alcoolisme , Conduite avec facultés affaiblies , Humains , Études rétrospectives , Italie/épidémiologie , Mâle , Femelle , Alcoolisme/épidémiologie , Adulte , Adulte d'âge moyen , Conduite avec facultés affaiblies/statistiques et données numériques , Patients en consultation externe , Transferrine/analyse , Transferrine/métabolisme , Transferrine/analogues et dérivés , Diagnostic précoce , Sujet âgé , Conduite automobileRÉSUMÉ
With rapid increases in incidence, diverse subtypes, and complicated etiologies, kidney disease remains a global public health problem. Iron, as an essential trace element, has pleiotropic effects on renal function and the progression of kidney diseases. A two-sample Mendelian randomization (MR) analysis was implemented to determine the potential causal effects between systemic iron status on different kidney diseases. Systemic iron status was represented by four iron-related biomarkers: serum iron, ferritin, transferrin saturation (TfSat), and total iron binding capacity (TIBC). For systemic iron status, 163,511, 246,139, 131,471, and 135,430 individuals were included in the genome-wide association study (GWAS) of serum iron, ferritin, TfSat, and TIBC, respectively. For kidney diseases, 653,143 individuals (15,658 cases and 637,485 controls), 657,076 individuals (8160 cases and 648,916 controls), and 659,320 individuals (10,404 cases and 648,916 controls) were included for immunoglobulin A nephropathy (IgAN), acute kidney disease (AKD), and chronic kidney disease (CKD), respectively. Our MR results showed that increased serum iron [odds ratio (OR): 1.10; 95% confidence interval (95% CI): 1.04, 1.16; p < 0.0042], ferritin (OR: 1.30; 95% CI: 1.14, 1.48; p < 0.0042), and TfSat (OR: 1.07; 95% CI: 1.04, 1.11; p < 0.0042)] and decreased TIBC (OR: 0.92; 95% CI: 0.88, 0.97; p < 0.0042) were associated with elevated IgAN risk. However, no significant associations were found between systemic iron status and AKD or CKD. In our MR study, the genetic evidence supports elevated systemic iron status as a causal effect on IgAN, which suggests a potential protective effect of iron chelation on IgAN patients.
Sujet(s)
Ferritines , Étude d'association pangénomique , Fer , Analyse de randomisation mendélienne , Humains , Fer/sang , Ferritines/sang , Marqueurs biologiques/sang , Insuffisance rénale chronique/sang , Insuffisance rénale chronique/génétique , Transferrine/analyse , Transferrine/métabolisme , Facteurs de risque , Maladies du rein/sang , Maladies du rein/génétique , Glomérulonéphrite à dépôts d'IgA/sang , Glomérulonéphrite à dépôts d'IgA/génétique , Mâle , Polymorphisme de nucléotide simple , FemelleRÉSUMÉ
Transferrin (TRF), recognized as a glycoprotein clinical biomarker and therapeutic target, has its concentration applicable for disease diagnosis and treatment monitoring. Consequently, this study developed boronic acid affinity magnetic surface molecularly imprinted polymers (B-MMIPs) with pH-responsitivity as the "capture probe" for TRF, which have high affinity similar to antibodies, with a dissociation constant of (3.82 ± 0.24) × 10-8 M, showing 7 times of reusability. The self-copolymerized imprinted layer synthesized with dopamine (DA) and 3-Aminophenylboronic acid (APBA) as double monomers avoided nonspecific binding sites and produced excellent adsorption properties. Taking the gold nanostar (AuNS) with a branch tip "hot spot" structure as the core, the silver-coated AuNS functionalized with the biorecognition element 4-mercaptophenylboronic acid (MPBA) was employed as a surface-enhanced Raman scattering (SERS) nanotag (AuNS@Ag-MPBA) to label TRF, thereby constructing a double boronic acid affinity "sandwich" SERS biosensor (B-MMIPs-TRF-SERS nanotag) for the highly sensitive detection of TRF. The SERS biosensor exhibited a detection limit for TRF of 0.004 ng/mL, and its application to spiked serum samples confirmed its reliability and feasibility, demonstrating significant potential for clinical TRF detection. Moreover, the SERS biosensor designed in this study offers advantages in stability, detection speed (40 min), and cost efficiency. The portable Raman instrument for SERS detection fulfills the requirements for point-of-care testing.
Sujet(s)
Techniques de biocapteur , Acides boroniques , Or , Analyse spectrale Raman , Acides boroniques/composition chimique , Techniques de biocapteur/méthodes , Or/composition chimique , Humains , Analyse spectrale Raman/méthodes , Argent/composition chimique , Nanoparticules métalliques/composition chimique , Limite de détection , Transferrine/analyse , Transferrine/composition chimique , Empreinte moléculaire , Polymères à empreintes moléculaires/composition chimique , Glycoprotéines/sang , Glycoprotéines/composition chimique , Matériaux biomimétiques/composition chimique , Dopamine/sang , Dopamine/analyse , ThiolsRÉSUMÉ
BACKGROUND: Our objective is to develop a predictive model utilizing the ferritin and transferrin ratio (FTR) and clinical factors to forecast overall survival (OS) in breast cancer (BC) patients. METHODS: We conducted a retrospective analysis of clinical data from 2858 BC patients diagnosed between 2013 and 2021. Subsequently, the cohort of 2858 BC patients underwent random assignment into distinct subsets: a training cohort comprising 2002 patients and a validation cohort comprising 856 patients, maintaining a proportional ratio of 7:3. Employing multivariable Cox regression analysis within the training cohort, we derived a prognostic nomogram. The predictive performance was assessed using calibration curves, C-index, and decision curve analysis. RESULTS: The final prognostic model included the TNM stage, subtype, hemoglobin levels, and the ferritin-transferrin ratio. The nomogram achieved a C-index of .794 (95% CI: .777-.810). The nomogram demonstrated superior predictive accuracy for OS at 3, 5, and 7 years for BC, with area under the time-dependent curves of .812, .782, and .773, respectively. These values notably outperformed those of the conventional TNM stage. Decision curve analysis reaffirmed the greater net benefit of our nomogram compared to the TNM stage. These findings were subsequently validated in the independent validation cohort. CONCLUSION: The FTR-based prognostic model may predict a patient's OS better than the TNM stage in a clinical setting. The nomogram can provide an early, affordable, and reliable tool for survival prediction, as well as aid clinicians in treatment option-making and prognosis evaluation. However, further multi-center prospective trials are required to confirm the reliability of the existing nomogram.
BackgroundOur objective is to develop a predictive model utilizing the ferritin and transferrin ratio (FTR) and clinical factors to forecast overall survival (OS) in breast cancer (BC) patients.MethodsWe conducted a retrospective analysis of clinical data from 2858 BC patients diagnosed between 2013 and 2021. Subsequently, the cohort of 2858 BC patients underwent random assignment into distinct subsets: a training cohort comprising 2002 patients and a validation cohort comprising 856 patients, maintaining a proportional ratio of 7:3. Employing multivariable Cox regression analysis within the training cohort, we derived a prognostic nomogram. The predictive performance was assessed using calibration curves, C-index, and decision curve analysis.ResultsThe final prognostic model included the TNM stage, subtype, hemoglobin levels, and the ferritin-transferrin ratio. The nomogram achieved a C-index of .794 (95% CI: .777-.810). The nomogram demonstrated superior predictive accuracy for OS at 3, 5, and 7 years for BC, with area under the time-dependent curves of .812, .782, and .773, respectively. These values notably outperformed those of the conventional TNM stage. Decision curve analysis reaffirmed the greater net benefit of our nomogram compared to the TNM stage. These findings were subsequently validated in the independent validation cohort.ConclusionThe FTR-based prognostic model may predict a patient's OS better than the TNM stage in a clinical setting. The nomogram can provide an early, affordable, and reliable tool for survival prediction, as well as aid clinicians in treatment option-making and prognosis evaluation. However, further multi-center prospective trials are required to confirm the reliability of the existing nomogram.
Sujet(s)
Tumeurs du sein , Ferritines , Nomogrammes , Transferrine , Humains , Tumeurs du sein/mortalité , Tumeurs du sein/anatomopathologie , Tumeurs du sein/sang , Femelle , Ferritines/sang , Transferrine/analyse , Transferrine/métabolisme , Adulte d'âge moyen , Études rétrospectives , Pronostic , Adulte , Sujet âgé , Stadification tumoraleRÉSUMÉ
Breast cancer (BC) remains a significant health concern for women globally, prompting the relentless pursuit of novel therapeutic modalities. As a traditional Chinese medicine, Boswellia carterii has been extensively used to treat various cancers, such as BC. However, the anti-BC effect and underlying mechanism of Boswellia carterii remain largely unclear. The aim of this study is to explore the therapeutic effect of Boswellia carterii n-hexane extract (BCHE) against BC as well as its underlying mechanism. The present study showed that BCHE significantly suppressed the viability of human BC cells. Moreover, BCHE exhibited potent anti-BC activity in vivo with no significant toxic effects. Additionally, BCHE induced ferroptosis via increased Transferrin expression and the intracellular accumulation of Fe2+, as well as decreased glutathione peroxidase 4 (GPX4) expression and the upregulation of reactive oxygen species (ROS)-induced lipid peroxidation in BC cells. In vivo experimental results also demonstrated that BCHE effectively induced ferroptosis through GPX4 downregulation and Transferrin upregulation in tumor-bearing mice. Overall, BCHE inhibited the growth of BC cells by inducing ferroptosis mediated by modulating the iron accumulation pathway and the lipid peroxidation pathway. Therefore, BCHE could serve as a potential ferroptosis-targeting drug for treating BC.
Sujet(s)
Boswellia , Tumeurs du sein , Ferroptose , Phospholipid hydroperoxide glutathione peroxidase , Extraits de plantes , Transferrine , Ferroptose/effets des médicaments et des substances chimiques , Phospholipid hydroperoxide glutathione peroxidase/métabolisme , Humains , Tumeurs du sein/traitement médicamenteux , Tumeurs du sein/métabolisme , Tumeurs du sein/anatomopathologie , Femelle , Animaux , Transferrine/métabolisme , Souris , Extraits de plantes/pharmacologie , Extraits de plantes/composition chimique , Lignée cellulaire tumorale , Boswellia/composition chimique , Espèces réactives de l'oxygène/métabolisme , Tests d'activité antitumorale sur modèle de xénogreffe , Prolifération cellulaire/effets des médicaments et des substances chimiques , Hexanes/composition chimique , Régulation négative/effets des médicaments et des substances chimiques , Peroxydation lipidique/effets des médicaments et des substances chimiques , Régulation positive/effets des médicaments et des substances chimiques , Régulation de l'expression des gènes tumoraux/effets des médicaments et des substances chimiques , Souris nude , Souris de lignée BALB CRÉSUMÉ
Importance: The prevalence of iron deficiency varies widely according to how it is defined. Objective: To compare the prevalence of iron deficiency among women using 3 different definitions. Design, Setting, and Participants: The cross-sectional Hemochromatosis and Iron Overload Screening Study (HEIRS; 2000-2006) evaluated the prevalence, determinants, and outcomes of hemochromatosis and other iron-related disorders. Multiethnic, primary care-based screening (2001-2003) was performed at 5 field centers (4 in the US and 1 in Canada). Volunteer women aged 25 years and older were recruited at primary care venues associated with the field centers. Data were analyzed from June to December 2023. Main Outcomes and Measures: Measures included transferrin saturation, serum ferritin level, and self-reported age, pregnancy, and race and ethnicity. Three iron deficiency definitions were studied: (1) combined transferrin saturation less than 10% and serum ferritin less than 15 ng/mL (HEIRS), (2) serum ferritin less than 15 ng/mL (World Health Organization [WHO]), and (3) serum ferritin less than 25 ng/mL (a threshold for iron-deficient erythropoiesis [IDE]). Results: Among 62â¯685 women (mean [SD] age, 49.58 [14.27] years), 1957 women (3.12%) had iron deficiency according to the HEIRS definition, 4659 women (7.43%) had iron deficiency according to the WHO definition, and 9611 women (15.33%) had iron deficiency according to the IDE definition. Among 40â¯381 women aged 25 to 54 years, 1801 women (4.46%) had iron deficiency according to HEIRS, 4267 women (10.57%) had iron deficiency according to WHO, and 8573 women (21.23%) had iron deficiency according to IDE. Prevalence rates of iron deficiency among 2039 women aged 25 to 44 years who reported pregnancy were 5.44% (111 women) according to HEIRS, 18.05% (368 women) according to WHO, and 36.10% (736 women) according to IDE. Iron deficiency prevalence by the 3 respective definitions increased significantly in each racial and ethnic group and was significantly higher among Black and Hispanic participants than Asian and White participants. The relative iron deficiency prevalence among the 62â¯685 women increased 2.4-fold (95% CI, 2.3-2.5; P < .001) using the WHO definition and increased 4.9-fold (95% CI, 4.7-5.2; P < .001) using the IDE definition. Conclusions and Relevance: Three definitions of iron deficiency were associated with significantly different prevalence of iron deficiency in women, regardless of self-reported age, pregnancy, or race and ethnicity. Using higher serum ferritin thresholds to define iron deficiency could lead to diagnosis and treatment of more women with iron deficiency and greater reduction of related morbidity.
Sujet(s)
Anémie par carence en fer , Ferritines , Humains , Femelle , Prévalence , Canada/épidémiologie , Adulte , Études transversales , Adulte d'âge moyen , États-Unis/épidémiologie , Anémie par carence en fer/épidémiologie , Anémie par carence en fer/sang , Anémie par carence en fer/diagnostic , Ferritines/sang , Transferrine/analyse , Transferrine/métabolisme , Grossesse , Carences en fer , Sujet âgéRÉSUMÉ
Physiological or pathophysiological changes lead to posttranslational changes in the sialic acid content of human serum transferrin (hTf), an essential mediator of iron transport in the human body, resulting in a significantly increased concentration of desialylated hTf. The intrinsic fluorescence quenching upon binding of iron to hTf was successfully modeled using the binding polynomial for two iron-binding sites, allowing measurements in a high-throughput format. Removal of sialic acid residues resulted in a 3-fold increase in iron binding affinity for both sites of hTf at pH 7.4. The pH-dependence of iron binding showed significant differences in equilibrium constants, resulting in a 10-fold increase in binding affinity for desialylated hTf at pH 5.9. The changes in hTf sialylation apparently result in tuning of the stability of the conformational state, which in turn contributes to the stability of the diferric hTf. The observed differences in the conditional thermodynamic equilibrium constants suggest that the desialylated protein has a higher preference for diferric hTf over monoferric hTf species down to pH 6.5, which may also influence the interaction with transferrin receptors that preferentially bind to diferric hTf. The results suggest a link between changes in hTf glycan structure and alterations in iron binding equilibrium associated with tissue acidosis.
Sujet(s)
Liaison aux protéines , Transferrine , Transferrine/métabolisme , Transferrine/composition chimique , Humains , Concentration en ions d'hydrogène , Fer/métabolisme , Fer/composition chimique , Acide N-acétyl-neuraminique/composition chimique , Acide N-acétyl-neuraminique/métabolisme , Composés du fer III/composition chimique , Composés du fer III/métabolisme , Sites de fixation , ThermodynamiqueRÉSUMÉ
Transferrin (TRF), a glycoprotein involved in cellular iron uptake, is a potential target for the diagnosis and treatment of several diseases and cancers. Therefore, the identification and isolation of TRF is clinically important. In this work, we prepared magnetic molecularly imprinted polymers (EMIP) based on metal chelation using norepinephrine and 3-aminophenylboronic acid as functional monomers. The obtained EMIP shows excellent recognition of TRF with the adsorption capacity of 94.2 mg/g and imprinting factor of 3.50. In addition, EMIP was characterized by high specificity, good adsorption performance and stability, and was successfully used for the analysis of TRF in human serum. The present study provides a reliable scheme for targeted epitope imprinting of polymers with metal chelating and dual-functional monomers, showing great potential for biosample analysis.
Sujet(s)
Acides boroniques , Polymères à empreintes moléculaires , Transferrine , Transferrine/composition chimique , Transferrine/isolement et purification , Humains , Adsorption , Polymères à empreintes moléculaires/composition chimique , Acides boroniques/composition chimique , Empreinte moléculaire , Épitopes/composition chimique , Polymères/composition chimique , Chromatographie en phase liquide à haute performance/méthodesRÉSUMÉ
The bloodstream form of Trypanosoma brucei expresses large poly-N-acetyllactosamine (pNAL) chains on complex N-glycans of a subset of glycoproteins. It has been hypothesised that pNAL may be required for receptor-mediated endocytosis. African trypanosomes contain a unique family of glycosyltransferases, the GT67 family. Two of these, TbGT10 and TbGT8, have been shown to be involved in pNAL biosynthesis in bloodstream form Trypanosoma brucei, raising the possibility that deleting both enzymes simultaneously might abolish pNAL biosynthesis and provide clues to pNAL function and/or essentiality. In this paper, we describe the creation of a TbGT10 null mutant containing a single TbGT8 allele that can be excised upon the addition of rapamycin and, from that, a TbGT10 and TbGT8 double null mutant. These mutants were analysed by lectin blotting, glycopeptide methylation linkage analysis and flow cytometry. The data show that the mutants are defective, but not abrogated, in pNAL synthesis, suggesting that other GT67 family members can compensate to some degree for loss of TbGT10 and TbGT8. Despite there being residual pNAL synthesis in these mutants, certain glycoproteins appear to be particularly affected. These include the lysosomal CBP1B serine carboxypeptidase, cell surface ESAG2 and the ESAG6 subunit of the essential parasite transferrin receptor (TfR). The pNAL deficient TfR in the mutants continued to function normally with respect to protein stability, transferrin binding, receptor mediated endocytosis of transferrin and subcellular localisation. Further the pNAL deficient mutants were as viable as wild type parasites in vitro and in in vivo mouse infection experiments. Although we were able to reproduce the inhibition of transferrin uptake with high concentrations of pNAL structural analogues (N-acetylchito-oligosaccharides), this effect disappeared at lower concentrations that still inhibited tomato lectin uptake, i.e., at concentrations able to outcompete lectin-pNAL binding. Based on these findings, we recommend revision of the pNAL-dependent receptor mediated endocytosis hypothesis.
Sujet(s)
Endocytose , Glycosyltransferase , Transferrine , Trypanosoma brucei brucei , Trypanosoma brucei brucei/métabolisme , Trypanosoma brucei brucei/génétique , Animaux , Endocytose/physiologie , Souris , Transferrine/métabolisme , Glycosyltransferase/métabolisme , Glycosyltransferase/génétique , Maladie du sommeil/parasitologie , Maladie du sommeil/métabolisme , Mutation , Protéines de protozoaire/métabolisme , Protéines de protozoaire/génétique , Récepteurs à la transferrine/métabolisme , Récepteurs à la transferrine/génétique , PolyosidesRÉSUMÉ
INTRODUCTION: The role of iron homeostasis has become increasingly recognized as a key factor in determining a prognosis of patients with heart failure (HF). Disruptions in iron balance, encompassing deficiency and overload, can affect patient prognosis, and therefore, significantly impact treatment and management strategies. OBJECTIVES: The study investigated possible associations between iron homeostasis-related indicators and longterm mortality as well as firstadmission mortality in individuals with HF. PATIENTS AND METHODS: Data on 3483 HF patients from the MIMICIV database were retrospectively analyzed. The relationship between iron homeostasis-related indicators (ferritin, serum iron, transferrin, and total iron binding capacity [TIBC]) and the first-admission and long-term mortality of HF patients was discerned utilizing the Cox proportional hazards model and the Kaplan-Meier survival analysis. Additionally, the predictive capability of these indicators for patient prognosis was assessed using the receiver operating characteristic curve. RESULTS: Fourth quartile levels of ferritin and serum iron were obviously associated with poor longterm outcomes in HF patients. Conversely, fourth quartile levels of transferrin and TIBC served as protective factors and were associated with a lower mortality. Additionally, iron homeostasis indicators exhibited a certain predictive value for both longterm mortality and firstadmission mortality in HF patients. CONCLUSIONS: This study underscores a significant association between iron homeostasis indicators and the prognosis of HF patients, providing valuable insights into risk stratification and clinical decisionmaking for this population. Future studies should focus on dynamic fluctuations in iron homeostasis and explore interventions to improve the prognosis of HF patients.
Sujet(s)
Ferritines , Défaillance cardiaque , Homéostasie , Fer , Humains , Défaillance cardiaque/mortalité , Défaillance cardiaque/sang , Femelle , Mâle , Études rétrospectives , Pronostic , Fer/sang , Fer/métabolisme , Adulte d'âge moyen , Sujet âgé , Ferritines/sang , Transferrine/métabolisme , Transferrine/analyseRÉSUMÉ
Antibodies that can selectively remove rogue proteins in the brain are an obvious choice to treat neurodegenerative disorders (NDs), but after decades of efforts, only two antibodies to treat Alzheimer's disease are approved, dozens are in the testing phase, and one was withdrawn, and the other halted, likely due to efficacy issues. However, these outcomes should have been evident since these antibodies cannot enter the brain sufficiently due to the blood-brain barrier (BBB) protectant. However, all products can be rejuvenated by binding them with transferrin, preferably as smaller fragments. This model can be tested quickly and at a low cost and should be applied to bapineuzumab, solanezumab, crenezumab, gantenerumab, aducanumab, lecanemab, donanemab, cinpanemab, and gantenerumab, and their fragments. This paper demonstrates that conjugating with transferrin does not alter the binding to brain proteins such as amyloid-ß (Aß) and α-synuclein. We also present a selection of conjugate designs that will allow cleavage upon entering the brain to prevent their exocytosis while keeping the fragments connected to enable optimal binding to proteins. The identified products can be readily tested and returned to patients with the lowest regulatory cost and delays. These engineered antibodies can be manufactured by recombinant engineering, preferably by mRNA technology, as a more affordable solution to meet the dire need to treat neurodegenerative disorders effectively.
Sujet(s)
Maladies neurodégénératives , Ingénierie des protéines , Humains , Maladies neurodégénératives/traitement médicamenteux , Maladies neurodégénératives/métabolisme , Ingénierie des protéines/méthodes , Transferrine/métabolisme , Barrière hémato-encéphalique/métabolisme , Barrière hémato-encéphalique/effets des médicaments et des substances chimiques , Peptides bêta-amyloïdes/métabolisme , Peptides bêta-amyloïdes/immunologie , Anticorps monoclonaux/usage thérapeutique , Anticorps monoclonaux/pharmacologie , Animaux , alpha-Synucléine/immunologie , alpha-Synucléine/métabolisme , Maladie d'Alzheimer/traitement médicamenteux , Maladie d'Alzheimer/métabolisme , Encéphale/métabolisme , Encéphale/anatomopathologieRÉSUMÉ
INTRODUCTION: Iron metabolism disorders and anemia are one of the main complications of end-stage renal disease that may affect the evaluation process for kidney transplantation. The study aimed to assess the iron metabolism in hemodialysis patients in relation to waiting list status. STUDY METHOD: The study included 5068 hemodialysis patients, including those on the active waiting list (N = 449) and those who were not eligible for the waitlist (N = 4619). Demographic and biochemical data, Charlson's comorbidity index, duration of hemodialysis therapy and, respectively, hemoglobin, ferritin, and transferrin saturation levels were compared in both groups of patients. RESULTS: Patients on the active waiting list were significantly younger -53.2 vs 67.2 years (P < .001), with a lower Charlson comorbidity index score: 3.33 vs 4.42 (P < .001). The duration of hemodialysis therapy was similar: 66.0 vs 63.2 months (P = .416), the incidence of anemia according to World Health Organization (90.6%, vs 91.2%) and KDIGO (72.4% vs 70.4%). The degree of anemia correction in terms of hemoglobin concentration and transferrin saturation was comparable in both groups and amounted to an average of 10.9 g/dL (P = .349) for hemoglobin concentration and 32.7% vs 33.4% (P = .513) for transferrin saturation. However, there was a statistically significant difference in ferritin concentration: 554 ug/L vs 733 ug/L (P = .001). CONCLUSIONS: Patients on the active list have significantly lower ferritin levels despite similar duration of hemodialysis treatment and comparable hemoglobin values. This may be due to lower inflammation, and less frequent blood transfusions, and lead to a lower risk of immunization and an increased chance of potential kidney transplantation.
Sujet(s)
Anémie , Fer , Défaillance rénale chronique , Transplantation rénale , Dialyse rénale , Listes d'attente , Humains , Transplantation rénale/effets indésirables , Adulte d'âge moyen , Femelle , Mâle , Anémie/sang , Anémie/étiologie , Sujet âgé , Défaillance rénale chronique/thérapie , Défaillance rénale chronique/chirurgie , Défaillance rénale chronique/complications , Fer/sang , Ferritines/sang , Hémoglobines/métabolisme , Hémoglobines/analyse , Transferrine/analyse , Transferrine/métabolisme , AdulteRÉSUMÉ
Recently, different alternative regulated cell death (RCD) pathways, viz., necroptosis, pyroptosis, ferroptosis, cuproptosis etc., have been explored as important targets for the development of cancer medications in recent years, as these can change the immunogenicity of the tumor microenvironment (TME) and will finally lead to the inhibition of cancer progression and metastasis. Here, we report the development of transferrin immobilized graphene oxide (Tfn@GOAPTES) nanocomposite as a therapeutic strategy toward cancer cell killing. The electrostatic immobilization of Tfn on the GOAPTES surface was confirmed by different spectroscopy and microscopy techniques. The Tfn immobilization was found to be â¼74 ± 4%, whereas the stability of the protein on the GO surface suggested a robust nature of the nanocomposite. The MTT assay suggested that Tfn@GOAPTES exhibited cytotoxicity toward HeLa cells via increased lipid peroxidation and DNA damage. Western blot studies resulted in decreased expression of acetylation on lysine 40 of α-tubulin and increased expression of LC3a/b for Tfn@GOAPTES treated HeLa cells, suggesting autophagy to be the main cause of the cell death mechanism. Overall, we predict that the present approach can be used as a therapeutic strategy for cancer cell killing via selective induction of a high concentration of intracellular iron.
Sujet(s)
Antinéoplasiques , Tests de criblage d'agents antitumoraux , Graphite , Nanocomposites , Transferrine , Graphite/composition chimique , Graphite/pharmacologie , Humains , Nanocomposites/composition chimique , Transferrine/composition chimique , Transferrine/pharmacologie , Antinéoplasiques/pharmacologie , Antinéoplasiques/composition chimique , Cellules HeLa , Taille de particule , Test de matériaux , Matériaux biocompatibles/composition chimique , Matériaux biocompatibles/pharmacologie , Fer/composition chimique , Fer/métabolisme , Survie cellulaire/effets des médicaments et des substances chimiques , Prolifération cellulaire/effets des médicaments et des substances chimiquesRÉSUMÉ
Vesicular transport is essential for delivering cargo to intracellular destinations. Evi5 is a Rab11-GTPase-activating protein involved in endosome recycling. In humans, Evi5 is a high-risk locus for multiple sclerosis, a debilitating disease that also presents with excess iron in the CNS. In insects, the prothoracic gland (PG) requires entry of extracellular iron to synthesize steroidogenic enzyme cofactors. The mechanism of peripheral iron uptake in insect cells remains controversial. We show that Evi5-depletion in the Drosophila PG affected vesicle morphology and density, blocked endosome recycling and impaired trafficking of transferrin-1, thus disrupting heme synthesis due to reduced cellular iron concentrations. We show that ferritin delivers iron to the PG as well, and interacts physically with Evi5. Further, ferritin-injection rescued developmental delays associated with Evi5-depletion. To summarize, our findings show that Evi5 is critical for intracellular iron trafficking via transferrin-1 and ferritin, and implicate altered iron homeostasis in the etiology of multiple sclerosis.
Sujet(s)
Protéines de Drosophila , Drosophila melanogaster , Ferritines , Protéines d'activation de la GTPase , Fer , Transferrine , Animaux , Drosophila melanogaster/métabolisme , Drosophila melanogaster/génétique , Protéines de Drosophila/métabolisme , Protéines de Drosophila/génétique , Endosomes/métabolisme , Ferritines/métabolisme , Ferritines/génétique , Fer/métabolisme , Transport des protéines , Transferrine/métabolisme , Protéines d'activation de la GTPase/génétique , Protéines d'activation de la GTPase/métabolismeRÉSUMÉ
BACKGROUND AND AIMS: Both iron overload and iron deficiency have been associated with cardiovascular diseases in observational studies. Previous Mendelian Randomization (MR) studies discovered a protective effect of higher iron status on coronary atrial disease, while a neutral effect on all-cause heart failure. Using two-sample MR, we evaluated how genetically predicted systemic iron status affects the risk of non-ischemic cardiomyopathy and different phenotypes. METHODS AND RESULTS: Two-sample MR analyses were performed to estimate the causal effect of four biomarkers of systemic iron status on diagnosed cardiomyopathy and its subtypes in 242,607 participants from the FinnGen research project. The level of transferrin saturation was significantly associated with an increased risk of cardiomyopathy (OR, 1.17; 95% CI, 1.13-1.38) when using nine separately selected genetic instruments. An increase in genetically determined serum iron (odds ratio [OR] per standard deviation [SD], 1.25; 95% confidence interval [CI], 1.13-1.38) and ferritin (OR, 1.49; 95% CI, 1.02-2.18) were associated with an increased risk of cardiomyopathy. Total iron binding capacity, a marker of reduced iron status, was inversely linked with cardiomyopathy (OR, 0.80; 95% CI, 0.65-0.98). The risk effect of iron status was more evident in hypertrophic cardiomyopathy and related heart failure. CONCLUSIONS: These analyses support the causal effect of increased systemic iron status on a higher risk of non-ischemic cardiomyopathy. A screening test for cardiomyopathy should be considered in patients with evidence of iron overload. Future study is needed for exploring the mechanism of these causal variants on cardiomyopathy.