A Food-Derived Dietary Supplement Containing a Low Dose of Iron Improved Markers of Iron Status Among Nonanemic Iron-Deficient Women

Objective: Iron deficiency is the most common nutrient deficiency in the world. While deficiency can often be resolved through dietary supplementation with iron, adverse events are common and frequently preclude compliance. The objective of this study was to determine whether a food-derived dietary supplement containing a low dose of iron and nutrients that increase iron absorption could resolve iron deficiency with fewer adverse events than reported at higher doses.

Methods: A pilot clinical trial (NCT02683369) was conducted among premenopausal women with nonanemic iron deficiency that was verified by blood screening. Participants consumed a dietary supplement (Blood Builder®/Iron Response®) once daily for 8 weeks containing 26 mg of iron, vitamin C, folate, and other food-derived nutrients. Primary outcomes were markers of iron status (serum ferritin, hemoglobin, soluble transferrin receptor, total body iron stores) and secondary outcomes were self-reported fatigue and energy. All outcomes were assessed at baseline and 8 weeks. Adverse events were monitored with questionnaires, daily diaries, and contact with a physician. Dependent samples t test and Wilcoxon signed-rank test were used to analyze outcomes.

Results: Twenty-three participants enrolled in the study. Iron deficiency was resolved in the sample (mean serum ferritin: baseline = 13.9 μg/L, 8 weeks = 21.1 μg/L, p < 0.001). All other markers of iron status, fatigue, and energy also improved during the study (p < 0.04). No adverse events were reported. Conclusions: While larger and controlled studies are needed to confirm these findings, a food-derived dietary supplement with a low dose of iron and absorption-enhancing nutrients resolved iron deficiency and improved all other markers of iron status without any adverse events.     

电针“委中”穴对腰多裂肌损伤大鼠铁代谢的调节

目的观察多时间点大鼠多裂肌损伤后铁代谢相关蛋白的变化规律,探讨不同干预时间条件下电针"委中"穴对多裂肌损伤性腰痛的治疗作用。方法 SD大鼠按随机数字表法分为正常组、模型组、电针组,每组30只,各组再分为1 d、2 d、3 d、5 d、7 d 5个亚组,每个亚组6只。采用注射0.5%布比卡因(bupivacaine, BPVC)的方法造模,电针组电针双侧"委中"穴(1次/d),正常组、模型组不进行电针干预。分别于治疗的1 d、2 d、3 d、5 d、7 d取材。采用HE染色观察造模前后多裂肌形态变化;采用生化法检测多裂肌组织总铁含量变化;采用Western blot法检测铁蛋白重链(ferritin heavy chain1, FTH1)含量;采用Real-time PCR法检测多裂肌膜蛋白转铁蛋白受体1(transferrin receptor 1, Tfr1)、二价金属转运蛋白1(divalent metal transporter 1, DMT1)mRNA的表达。结果 HE染色结果显示,模型组相较于正常组可见肌纤维断裂、坏死并伴有炎性细胞浸润;与同时间点模型组相比,电针组受损肌纤维可见明显改善。生化法检测结果显示,与同时间点正常组相比,模型组、电针组总铁含量升高(P<0.01);Western blot、Real-time PCR检测结果提示模型组FTH1蛋白表达低于正常组(P<0.05或P<0.01),而Tfr1与DMT1 mRNA表达均高于正常组(P<0.05或P<0.01);与同时间点模型组相比,电针1 d、2 d、3 d、5 d组FTH1蛋白表达升高(P<0.05或P<0.01),而电针2 d、3 d、5 d、7 d组Tfr1 m RNA和电针1 d、2 d、3 d、5 d组DMT1 mRNA表达均降低(P<0.05或P<0.01);各模型组间比较发现,模型2 d组FTH1蛋白表达最低(P<0.05),而模型2 d、3 d组Tfr1 mRNA表达较高(P<0.05),模型3 d组DMT1 mRNA表达最高(P<0.05);各电针组比较结果显示,FTH1蛋白在电针2 d组最高(P<0.05),电针3 d、5 d、7 d组Tfr1 mRNA表达较低(P<0.05),电针3 d组DMT1 mRNA表达较高(P<0.05)。结论在BPVC致多裂肌损伤模型中,局部受损多裂肌发生铁代谢紊乱,且在急性损伤期较典型。电针"委中"穴能促进损伤多裂肌的修复,其机制可能与调节多裂肌铁代谢、减轻组织过氧化损伤相关,并且在电针持续干预3 d后显著促进对铁代谢紊乱水平的调节。     

Transferrin is not involved in initial uptake process of iron in rat duodenal mucosa

The role of transferrin in iron absorption by the duodenal mucosa in rats with iron deficiency and controls was evaluated immunohistochemically. Ferric iron was administered to each rat using a metallic gastric tube. Transferrin was stained by an immunoperoxidase method and iron with Prussian blue in the same duodenal sections and observed by light microscopy. The localization of transferrin differed from that of ferric iron both in rats with iron deficiency and in controls. In iron-deficient rats, transferrin was weakly stained after iron administration but was strongly stained after saline administration. In contrast, in controls, transferrin was weakly stained after saline administration but was strongly stained after iron administration. By electron microscopy, x-ray energy spectrometric analysis of the transferrin-positive areas showed no iron peak. In iron-deficient rats, accumulation of electron-dense transferrinnegative microgranules was observed in some of the duodenal columnar epithelium. X-ray energy spectrometric analysis of this area revealed iron, indicating iron absorption. These results suggest that mucosal transferrin does not act as a shuttle protein in iron absorption via the rat duodenal columnar epithelium, and the function of this protein may be to inform the absorptive cells of the iron status of the body as observed in other organs.     

Soluble transferrin receptor in Aboriginal children with a high prevalence of iron deficiency and infection

OBJECTIVES: Aboriginal children in tropical Australia have a high prevalence of both iron deficiency and acute infections, making it difficult to differentiate their relative contributions to anaemia. The aims of this study were to compare soluble transferrin receptor with ferritin in iron deficiency anaemia (IDA), and to examine how best to distinguish the effect of iron deficiency from infection on anaemia. METHODS: We conducted a prospective study of 228 admissions to Royal Darwin Hospital in children from 6 to 60 months of age. Transferrin receptor concentrations were measured by a particle-enhanced immunoturbidimetric assay and ferritin by a microparticle enzyme immunoassay. RESULTS: On multiple regression, the best explanatory variables for haemoglobin differences (r2=33.7%, P<0.001) were mean corpuscular volume (MCV), red cell distribution width (RDW) and C-reactive protein (CRP); whereas transferrin receptor and ferritin were not significant (P>0.4). Using > or =2 abnormal indices (MCV, RDW, blood film)+haemoglobin <110 g/l as the reference standard for IDA, transferrin receptor produced a higher area under the curve on receiver operating characteristic curve analysis than ferritin (0.79 vs. 0.64, P<0.001) or the transferrin receptor-ferritin index (0.77). On logistic regression, the effect of acute infection (CRP) on haemoglobin was significant (P<0.001) at cut-offs of 105 and 110 g/l, but not at 100 g/l when only iron deficiency indicators (MCV, RDW, blood film) were significant. CONCLUSIONS: Transferrin receptor does not significantly improve the diagnosis of anaemia (iron deficiency vs. infection) over full blood count and CRP, but in settings with a high burden of infectious diseases and iron deficiency, it is a more reliable adjunctive measure of iron status than ferritin.     

脊髓内移植间充质干细胞的转铁蛋白受体显像

目的 探索放射性核素显像活体追踪移植干细胞的可能性.方法 用放射性受体分析定量测定体外培养人间充质干细胞(hMSCs)的转铁蛋白受体表达.兔脊髓内移植人间充质干细胞,蛛网膜下腔注入 131Ⅰ标记铁胞和转铁蛋白后不同时间,用伽玛相机采集图像.感兴趣区(ROI)技术对图像进行半定量分析.磷屏放射自显影验证活体显像.结果 hMSCs高表达转铁蛋白受体(10,770/细胞),并且对铁饱和转铁蛋白具有高亲和力(KD=0.982nmol/L).实验组动物在注射显像剂后16和24h观察到了移植区放射性浓聚灶,而以PBS作为移植物和以 131Ⅰ标记的血清白蛋白作为显像剂的2个对照组均呈阴性显像,ROI分析显示实验组与对照组之间具有显著的统计学差别(P＜0.05).磷屏放射自显影证实了间充质干细胞移植部位能够特异结合铁饱和转铁蛋白.结论 应用核素显像活体示踪移植干细胞具有可行性,经过进一步改进,有望为干细胞移植治疗提供无创的监测手段.     

Ferristatin II Efficiently Inhibits SARS-CoV-2 Replication in Vero Cells

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to have a significant impact on global public health. Multiple mechanisms for SARS-CoV-2 cell entry have been described; however, the role of transferrin receptor 1 (TfR1) in SARS-CoV-2 infection has received little attention. We used ferristatin II to induce the degradation of TfR1 on the surface of Vero cells and to study the consequences of such treatment on the viability of the cells and the replication of SARS-CoV-2. We demonstrated that ferristatin II is non-toxic for Vero cells in concentrations up to 400 µM. According to confocal microscopy data, the distribution of the labeled transferrin and receptor-binding domain (RBD) of Spike protein is significantly affected by the 18h pretreatment with 100 µM ferristatin II in culture medium. The uptake of RBD protein is nearly fully inhibited by ferristatin II treatment, although this protein remains bound on the cell surface. The findings were well confirmed by the significant inhibition of the SARS-CoV-2 infection of Vero cells by ferristatin II with IC₅₀ values of 27 µM (for Wuhan D614G virus) and 40 µM (for Delta virus). A significant reduction in the infectious titer of the Omicron SARS-CoV-2 variant was noted at a ferristatin II concentration as low as 6.25 µM. We hypothesize that ferristatin II blocks the TfR1-mediated SARS-CoV-2 host cell entry; however, further studies are needed to elucidate the full mechanisms of this virus inhibition, including the effect of ferristatin II on other SARS-CoV-2 receptors, such as ACE2, Neuropilin-1 and CD147. The inhibition of viral entry by targeting the receptor on the host cells, rather than the viral mutation-prone protein, is a promising COVID-19 therapeutic strategy.     

危重病人GH与TF变化的临床意义

目的：探讨生长激素（GH）和血清转铁蛋白（TF）对危重病人营养代谢的影响。方法：根据APACHE-Ⅱ评分标准,对不同病情（普通A组、危重B组、极危重C组）患者测定血清转铁蛋白及生长激素值,并对B组和C组的患者在疾病恢复期进行复查。结果：C组患者血清转铁蛋白水平低于B组,B组患者低于A组。B组病人的生长激素水平明显高于A组,C组病人与另两组差异均无显著性。进入恢复期后,患者血清转铁蛋白水平明显上升,而生长激素水平无明显下降。结论：急性危重症患者大多存在急性能量-蛋白质营养不良,并引起内分泌紊乱。血清转铁蛋白水平可反映患者营养状况及患者病情危重程度。     

The relationship between measurement of in vivo brain glutamate and markers of iron metabolism: A proton magnetic resonance spectroscopy study in healthy adults

Fundamental human studies which address associations between glutamate and iron metabolism are needed. Basic research reports associations between glutamate and iron metabolism. Human studies report sex differences in iron metabolism and glutamate concentrations, which suggest that these relationships may differ by sex. We hypothesised associations would be apparent between in vivo glutamate and peripheral markers of iron metabolism, and these associations would differ by sex. To test this, we recruited 40 healthy adults (20 men, 20 women) and measured (a) standard clinical biomarker concentrations for iron metabolism and (b) an in vivo proxy for glutamate concentration, glutamate with glutamine in relation to total creatine containing metabolites using proton magnetic resonance spectroscopy studies with a two‐dimensional chemical shift imaging slice, with voxels located in bilateral dorsolateral prefrontal cortices, anterior cingulate cortices and frontal white matter. Only the female group reported significant associations between peripheral markers of iron metabolism and Glx:tCr concentration: (a) right dorsolateral prefrontal cortex Glx:tCr associated positively with serum transferrin (r = .60, p = .006) and negatively with transferrin saturation (r = ?.62, p = .004) and (b) right frontal white matter Glx:tCr associated negatively with iron concentration (r = ?.59, p = .008) and transferrin saturation (r = ?.65, p = .002). Our results support associations between iron metabolism and our proxy for in vivo glutamate concentration (Glx:tCr). These associations were limited to women, suggesting a stronger regulatory control between iron and glutamate metabolism. These associations support additional fundamental research into the molecular mechanisms of this regulatory control.