TMT Quantitative Proteomics Analysis Reveals the Effects of Transport Stress on Iron Metabolism in the Liver of Chicken

Abnormal iron metabolism can cause oxidative stress in broilers, and transport stress (TS) may potentially influence iron metabolism. However, the mechanisms by which TS affects iron metabolism are unclear. This study used quantitative proteome analysis based on tandem mass tag (TMT) to investigate the effects of TS on liver iron metabolism in broilers. Broilers (n = 24) reared under the same conditions were selected randomly into the transported group for 4 h (T2) and non-transported group (T1). Results showed that the serum iron level and total iron-binding capacity of broilers in the T2 were significantly higher than those in the T1 (p < 0.05). The liver iron content of broilers in the T2 (0.498 ± 0.058 mg·gprot−1) was significantly higher than that in the T1 (0.357 ± 0.035 mg·gprot−1), and the iron-stained sections showed that TS caused the enrichment of iron in the liver. We identified 1139 differentially expressed proteins (DEPs). Twelve DEPs associated with iron metabolism were identified, of which eight were up-regulated, and four were down-regulated in T2 compared with T1. Prediction of the protein interaction network for DEPs showed that FTH1, IREB2, and HEPH play vital roles in this network. The results provide new insights into the effects of TS on broilers’ liver iron metabolism.

An Experimental Model for Iron Deficiency Anemia in Sows and Offspring Induced by Blood Removal during Gestation

Anemia is a common condition in sow herds. We aimed to study the effects of severe iron deficiency during gestation on sow and piglet health outcomes with an experimental model for blood-removal-induced iron deficiency anemia. In total, 18 multiparous sows (8 in trial I and 10 in trial II) were allocated to either a blood removal group or a control group. Hematologic parameters were monitored at regular intervals and the tissue iron concentrations were measured for the sows and newborn piglets after farrowing. In trial I, the mean liver iron content was reduced to 46.7 µg/g in the blood removal sows compared to 252.6 µg/g in the controls (p < 0.001). In trial II, sows in the blood removal group had lower iron content in the liver (147.8 µg/g), kidney (46.3 µg/g) and spleen (326.5 µg/g) compared to the control sows (323.2 µg/g, 81.3 µg/g and 728.9 µg/g, respectively; p = 0.009, 0.016, 0.01, respectively). In trial I, piglets from sows in the blood removal group had significantly decreased hematocrit (Hct), red blood cells (RBC) and a tendency for reduced hemoglobin (Hb) compared to the control piglets. We established a blood removal model that resulted in mild- to severe degrees of sow anemia and reduced tissue iron stores at farrowing.

FC 075POST-MORTEM HEPATIC AND BONE MARROW IRON CONTENT IN HEMODIALYSIS PATIENTS: A PROSPECTIVE COHORT STUDY

Background and Aims Studies using T2 MRI liver scans among Hemodialysis (HD) patients raised concern about the presence of iron overload in this population, regularly treated with intravenous (IV) iron. Histological evidence of tissue iron overload is scarce, since the majority of studies were performed in pre-erythropoiesis- stimulating agents (ESA’s) era, when blood transfusions were common. Primary objective: to quantify iron in the liver and bone marrow by biochemical and histological analysis, in adult CKD stage 5-HD. Secondary objectives: To explore association of clinical, laboratorial parameters, IV iron therapy and iron stores. Method After approval of local Ethical committee and informed consent from families, liver biopsy and bone marrow aspirate were obtained in the first 24h post-mortem from 21 chronic HD patients with anemia or under anemia treatment who died in Hospital Fernando Fonseca. Exclusion criteria: blood transfusion in the previous 2 weeks, acute or chronic liver disease, HIV infection, known hematologic or oncologic disease. Clinical, laboratorial and anemia therapy data were retrieved from hospital registry and outpatient HD centers. Biochemical liver iron content (LIC) was quantified by atomic absorption spectrophotometry. Histological semi-quantitative grading of iron storage was made in the liver and bone marrow using Scheuer’s and Gale’s criteria of grading Perls’ stain, respectively. Results Of 21 patients included, 10 (47,6%) were male, median (IQR) age 76.0 (67.5-85.5) years old, 18 (85.7%) white, 3 (14.3%) black, dialysis vintage was 47.0 (12.5-104.0) months. Charlson Comorbidity index was 10.0 (7.5-11.0), 7 (33%) patients had diabetes, and 11 (52.4%) used an arteriovenous fistula as vascular access. The cause of death was infection (n=9, 42.9%), cardiovascular (N=6, 28.6%), HD withdrawal (n=2, 9.5%) and unknown =3 (14.3%). Median (IQR) hemoglobin was 9.8 (8.5-11.4) g/dl and 11 (52.3%) patients had hemoglobin &lt;10 g/dl. Ferritin was 494.0 (136.0-850.5) ng/ml and TSAT 19.9 % (13.3-26.0). 19 (90.5%) patients were receiving IV iron therapy. Median (IQR) IV iron administered in the previous 6 and 12 months before death was 800 (300-1250) mg and 1500 (650-2175) mg, respectively. All patients were on ESA therapy, median (IQR) dose 5000 (3000-9000) UI/week and erythropoietin resistance index was 9.6 (4.2-16.6). Median (IQR) liver iron content determined by atomic absorption was 42.5 (22.9-69.7) µmol/g. 9 patients (42.9%) had normal LIC (&lt;36 μmol/g), while the remainder had mild to moderate overload. Median (IQR) Scheuer grade was 2 (1-3) and 13 (62%) of liver biopsies had increased (Scheuer grade &gt; 1) iron deposition at histology. Median (IQR) grade of Perls staining in the bone marrow was 3 (3-4) and 9 (45%) had increased (Gale’s grade &gt;3) iron content in the bone marrow. Iron semi-quantitative scores in liver and bone marrow had strong positive correlation (r=0.71, p&lt;0.001). There was a strong positive correlation between LIC and ferritin (r=0.86, p &lt; 0.001) and also TSAT (r=0.56, n=16, p=0.02). Hemoglobin was negatively associated with LIC (r= -0.46, p=0.04), and with iron content in the bone marrow (p=0.04). LIC did not associate with ESA dose, C-reactive protein, dialysis vintage or other clinical parameters. There was no statistically significant association between the dose of IV iron administered in the previous 6 and 12 months with LIC, ferritin,TSAT or iron scores in bone marrow and liver. Conclusion In these HD patients, there was biochemical and histological evidence of iron accumulation in liver and bone marrow. Ferritin and TSAT showed strong correlation with iron deposits, but none was found with the dose of IV iron administered. In this study, anemia severity was associated with higher degree of iron storage both in the liver and bone marrow, suggesting a multilevel blocking mechanism of iron’s utilization.

Iron kinetics following treatment with sucroferric oxyhydroxide or ferric citrate in healthy rats and models of anaemia, iron overload or inflammation

Background The iron-based phosphate binders, sucroferric oxyhydroxide (SFOH) and ferric citrate (FC), effectively lower serum phosphorus in clinical studies, but gastrointestinal iron absorption from these agents appears to differ. We compared iron uptake and tissue accumulation during treatment with SFOH or FC using experimental rat models. Methods Iron uptake was evaluated during an 8-h period following oral administration of SFOH, FC, ferrous sulphate (oral iron supplement) or control (methylcellulose vehicle) in rat models of anaemia, iron overload and inflammation. A 13-week study evaluated the effects of SFOH and FC on iron accumulation in different organs. Results In the pharmacokinetic experiments, there was a minimal increase in serum iron with SFOH versus control during the 8-h post-treatment period in the iron overload and inflammation rat models, whereas a moderate increase was observed in the anaemia model. Significantly greater increases (P &lt; 0.05) in serum iron were observed with FC versus SFOH in the rat models of anaemia and inflammation. In the 13-week iron accumulation study, total liver iron content was significantly higher in rats receiving FC versus SFOH (P &lt; 0.01), whereas liver iron content did not differ between rats in the SFOH and control groups. Conclusions Iron uptake was higher from FC versus SFOH following a single dose in anaemia, iron overload and inflammation rat models and 13 weeks of treatment in normal rats. These observations likely relate to different physicochemical properties of SFOH and FC and suggest distinct mechanisms of iron absorption from these two phosphate binders.

GSTM1 and Liver Iron Content in Children with Sickle Cell Anemia and Iron Overload

Chronic blood transfusions in patients with sickle cell anemia (SCA) cause iron overload, which occurs with a degree of interpatient variability in serum ferritin and liver iron content (LIC). Reasons for this variability are unclear and may be influenced by genes that regulate iron metabolism. We evaluated the association of the copy number of the glutathione S-transferase M1 (GSTM1) gene and degree of iron overload among patients with SCA. We compared LIC in 38 children with SCA and ≥12 lifetime erythrocyte transfusions stratified by GSTM1 genotype. Baseline LIC was measured using magnetic resonance imaging (MRI), R2*MRI within 3 months prior to, and again after, starting iron unloading therapy. After controlling for weight-corrected transfusion burden (mL/kg) and splenectomy, mean pre-chelation LIC (mg/g dry liver dry weight) was similar in all groups: GSTM1 wild-type (WT) (11.45, SD±6.8), heterozygous (8.2, SD±4.52), and homozygous GSTM1 deletion (GSTM1-null; 7.8, SD±6.9, p = 0.09). However, after >12 months of chelation, GSTM1-null genotype subjects had the least decrease in LIC compared to non-null genotype subjects (mean LIC change for GSTM1-null = 0.1 (SD±3.3); versus −0.3 (SD±3.0) and −1.9 (SD±4.9) mg/g liver dry weight for heterozygous and WT, respectively, p = 0.047). GSTM1 homozygous deletion may prevent effective chelation in children with SCA and iron overload.

Association between Different Animal Protein Sources and Liver Status in Obese Subjects with Non-Alcoholic Fatty Liver Disease: Fatty Liver in Obesity (FLiO) Study

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome. Obesity and unhealthy dietary habits are described as risk factors for NAFLD. The aim of this study was to investigate the association between the consumption of different animal protein sources and hepatic status in NAFLD adults. A total of 112 overweight/obese participants with NAFLD from Fatty Liver in Obesity (FLiO) study were evaluated at baseline. Diet, body composition, and biochemical variables were evaluated. Hepatic status was also assessed by Magnetic Resonance Imaging, ultrasonography, and elastography. Red meat consumption showed a positive relationship with liver iron content (r = 0.224; p = 0.021) and ferritin concentration (r = 0.196; p = 0.037). Processed meat consumption exhibited a positive association with liver iron content (r = 0.308; p = 0.001), which was also found in the quantile regression (β = 0.079; p = 0.028). Fish consumption was related with lower concentration of ferritin (r = −0.200; p = 0.034). This association was further evidenced in the regression model (β = −0.720; p = 0.033). These findings suggest that the consumption of different animal protein sources differentially impact on liver status in obese subjects with NAFLD, showing fish consumption as a healthier alternative for towards NAFLD features.