A key mutation in magnesium chelatase I subunit leads to a chlorophyll-deficient mutant of tea (Camellia sinensis).

Tea (Camellia sinensis) is a highly important beverage crop renowned for its unique flavour and health benefits. Chlorotic mutants of tea, known worldwide for their umami taste and economic value, have gained global popularity. However, the genetic basis of this chlorosis trait remains unclear. In this study, we identified a major-effect quantitative trait locus (QTL), qChl-3, responsible for the chlorosis trait in tea leaves, linked to a non-synonymous polymorphism (G1199A) in the magnesium chelatase I subunit (CsCHLI). Homozygous CsCHLIA plants exhibited an albino phenotype due to defects in magnesium protoporphyrin IX and chlorophylls in the leaves. Biochemical assays revealed that CsCHLI mutations did not affect subcellular localization or interactions with CsCHLIG and CsCHLD. However, combining CsCHLIA with CsCHLIG significantly reduced ATPase activity. RNA-seq analysis tentatively indicated that CsCHLI inhibited photosynthesis and enhanced photoinhibition, which in turn promoted protein degradation and increased the amino acid levels in chlorotic leaves. RT-qPCR and enzyme activity assays confirmed the crucial role of asparagine synthetase and arginase in asparagine and arginine accumulation, with levels increasing over 90-fold in chlorotic leaves. Therefore, this study provides insights into the genetic mechanism underlying tea chlorosis and the relationship between chlorophyll biosynthesis and amino acid metabolism.

Diagnosis of iron-deficient states.

The diagnosis of iron deficiency anemia is typically straightforward, especially when classic biochemical and hematological changes are present in a subject at risk. It can be challenging in the presence of diseases or when it is due to inherited defects of iron metabolism. The identification of iron deficiency prior to anemia development is also difficult. New hematological parameters such as reticulocyte Hb content have expanded the classic ones such as MCV, MCH and MCHC. A variety of hematology analyzers now provide novel parameters to assess cellular hypochromia and microcytosis in both reticulocytes and mature red blood cells. The repertoire of biochemical markers has also been expanded, with iron, transferrin and ferritin being supplemented by circulating transferrin receptor and hepcidin. Molecular identification of functional variants of key iron metabolism determinants has provided explanations for the heritability of some iron metabolism biomarkers. Genetic defects in some of these molecules are responsible for hereditary microcytic anemias, also called atypical microcytic anemias. In this review, we examine the most significant hematological and biochemical markers for iron metabolism, as well as relevant genetic polymorphisms and defects affecting iron handling.

Correlates of anaemia in pregnant urban South Indian women: a possible role of dietary intake of nutrients that inhibit iron absorption.

OBJECTIVE: To identify correlates of anaemia during the first trimester of pregnancy among 366 urban South Indian pregnant women. DESIGN: Cross-sectional study evaluating demographic, socio-economic, anthropometric and dietary intake data on haematological outcomes. SETTING: A government maternity health-care centre catering predominantly to the needs of pregnant women from the lower socio-economic strata of urban Bangalore. SUBJECTS: Pregnant women (n 366) aged ≥18 and ≤40 years, who registered for antenatal screening at ≤14 weeks of gestation. RESULTS: Mean age was 22·6 (sd 3·4) years, mean BMI was 20·4 (sd 3·3) kg/m2 and 236 (64·5 %) of the pregnant women were primiparous. The prevalence of anaemia (Hb <11·0 g/dl) was 30·3 % and of microcytic anaemia (anaemia with mean corpuscular volume <80 fl) 20·2 %. Mean dietary intakes of energy, Ca, Fe and folate were well below the Indian RDA. In multivariable log-binomial regression analysis, anaemia was independently associated with high dietary intakes of Ca (relative risk; 95 % CI: 1·79; 1·16, 2·76) and P (1·96; 1·31, 2·96) and high intake of meat, fish and poultry (1·94; 1·29, 2·91). CONCLUSIONS: Low dietary intake of multiple micronutrients, but higher intakes of nutrients that inhibit Fe absorption such as Ca and P, may help explain high rates of maternal anaemia in India.

[Effects of different doses of iron supplement on function of mitochondrial respiration of liver during exercise-induced hypochromic rats].

OBJECTIVE: To investigate the effects of iron supplement on function of mitochondrial respiratory of liver during exercise-induced hypochromic rats. METHOD: Forty healthy male Wistar rats were randomized into 5 groups (n = 8): static control (C), exercise-training (T), training with supplementation of small dose iron (S + T), training with supplementation of middle dose iron (M + T) and training with supplementation of large dose iron (L + T). Training performed incremental exercise for 8 weeks, 6 days/week, iron supplementation from the fifth week. Liver were prepared immediately after exhaustive running. Liver mitochondria were extracted by differential centrifugation. Spectrophotometric analysis was used to evaluate activities of electron transport chain complex (C) I-IV in liver mitochondria. RESULTS: (1) C I, CII and CIV activities in T group were increased significantly (P < 0.05, P < 0.01), CI - C IV activities in S + T, M + T and L + T groups were increased significantly (P < 0.05, P < 0.01) compared with those in C group. (2) CII activity in S + T group was increased remarkably (P < 0.05); CIII and CIV activities in M + T group were increased remarkably (P < 0.01); CI - CIV activities in L+ T group were increased remarkably (P < 0.05, P < 0.01) compared with those in T group. CONCLUSION: Large load exercise training composite iron supplementation can improve function of mitochondrial respiration of liver and the aerobic capacity. From the athletic ability , the middle dose iron supplementation is better during large load exercise training.

Erythropoietin-driven signaling ameliorates the survival defect of DMT1-mutant erythroid progenitors and erythroblasts.

BACKGROUND: Hypochromic microcytic anemia associated with ineffective erythropoiesis caused by recessive mutations in divalent metal transporter 1 (DMT1) can be improved with high-dose erythropoietin supplementation. The aim of this study was to characterize and compare erythropoiesis in samples from a DMT1-mutant patient before and after treatment with erythropoietin, as well as in a mouse model with a DMT1 mutation, the mk/mk mice. DESIGN AND METHODS: Colony assays were used to compare the in vitro growth of pre-treatment and post-treatment erythroid progenitors in a DMT1-mutant patient. To enable a comparison with human data, high doses of erythropoietin were administered to mk/mk mice. The apoptotic status of erythroblasts, the expression of anti-apoptotic proteins, and the key components of the bone marrow-hepcidin axis were evaluated. RESULTS: Erythropoietin therapy in vivo or the addition of a broad-spectrum caspase inhibitor in vitro significantly improved the growth of human DMT1-mutant erythroid progenitors. A decreased number of apoptotic erythroblasts was detected in the patient's bone marrow after erythropoietin treatment. In mk/mk mice, erythropoietin administration increased activation of signal transducer and activator of transcription 5 (STAT5) and reduced apoptosis in bone marrow and spleen erythroblasts. mk/mk mice propagated on the 129S6/SvEvTac background resembled DMT1-mutant patients in having increased plasma iron but differed by having functional iron deficiency after erythropoietin administration. Co-regulation of hepcidin and growth differentiation factor 15 (GDF15) levels was observed in mk/mk mice but not in the patient. CONCLUSIONS: Erythropoietin inhibits apoptosis of DMT1-mutant erythroid progenitors and differentiating erythroblasts. Ineffective erythropoiesis associated with defective erythroid iron utilization due to DMT1 mutations has specific biological and clinical features.

Allogeneic blood transfusion decreases with postoperative autotransfusion in hip and knee arthroplasty.

OBJECTIVES: We aimed to evaluate the effectiveness of postoperative autotransfusion method on prevention of the need of allogeneic blood transfusion in hip and knee arthroplasty. METHODS: Seventy-four patients who underwent 77 hip and knee arthroplasty operations were randomized into control and study groups, and evaluated prospectively. In the knee group (39 patients; 30 females, 9 males; mean age 66.6 years), cemented, cruciate retaining, and bicompartmental arthroplasty was performed under tourniquet control; whereas in the hip group (35 patients; 24 females, 11 males; mean age 59.3 years) cementless arthroplasty with posterolateral approach was performed. None of the patients received preoperative and intraoperative allogeneic blood transfusion. The collected blood in the surgical area was transfused with autotransfusion system to the patients in the study groups at the end of the fourth hour postoperatively. The mean amounts of autotransfused blood in hip and knee groups were 413 mL and 480 mL, respectively. Allogeneic blood transfusion was applied to the patients with hemoglobin level below 8 g/dL, hematocrit level below 25%, and clinical symptoms of anemia. RESULTS: Preoperative and postoperative hemoglobin-hematocrit levels did not differ significantly between study and control groups. Allogeneic blood transfusion was applied to one patient (5%) in study and 8 patients (38%) in control groups during knee arthroplasty (p=0.01); whereas 9 patients (53%) in study and 15 patients (79%) in control groups received allogeneic blood transfusion during hip arthroplasty (p=0.044). The amount of allogeneic blood transfusion in study groups was significantly lower than that in control groups (p=0.008 for knee arthroplasty, p=0.048 for hip arthroplasty). CONCLUSION: The need and amount of allogeneic transfusion were reduced with postoperative autotransfusion in both knee and hip arthroplasty groups with greater extent in knee arthroplasty.

Myelodysplasia and anemia of chronic disease in human tumor necrosis factor-alpha transgenic mice.

TNF-alpha is a pleitropic cytokine that expresses both pro- and anti-inflammatory activity and transgenic mice expressing human tumor necrosis factor-alpha (TNF-alpha) exhibit a progressive polyarthritis that models rheumatoid arthritis (RA). One of the common comorbidities of RA is anemia of chronic disease (ACD). The purpose of these experiments was to study the changes in the bone marrow and peripheral blood that accompany polyarthritis in TNF-alpha transgenic mice in an effort to better understand the pathogenesis of myelodysplasia and ACD. Polychromatic cytometry, hematology and serum cytokine analysis were used to study the pathogenesis of ACD in human TNF-alpha transgenic mice. Our hematological evaluation revealed a mild, compensated, microcytic hypochromic anemia, and monocytosis. In the bone marrow, we observed alterations in cell kinetics, decreased relative expression of transferrin receptor and increased apoptosis and cell death in several late precursor cell populations. Although significant levels of human TNF-alpha were found in the serum, neither change in serum murine erythropoietin nor any significant difference observed in serum levels of murine IL-beta, IL-5, IL-6, IL-10, IL-12(p70), IL-17, TNF-alpha, IFNgamma, GM-CSF, MIP-1alphaJE, MCP-5 was observed. Tg197 mice develop a compensated, microcytic, hypochromic anemia, and a functional iron deficiency by 9 weeks of age. Changes in peripheral blood are reflected in alterations in cell kinetics, transferrin receptor expression and markedly increased apoptosis and cell death in the bone marrow indicating that TNF-alpha may contribute to myelodysplasia in ACD. Moreover, since human TNF-alpha can interact only with murine TNFR1, our data suggest that TNFR1 may play an important role in the development of ACD.

Erythropoietin, iron metabolism, and red blood cell production.

Erythropoietin (EPO) plays a central role in the regulation of red blood cell (RBC) production. Since iron is an essential element for erythropoiesis and hemoglobin (Hb) synthesis, its importance is heightened in patients treated with epoetin alfa. Stimulation of erythropoiesis following the administration of epoetin alfa is associated with several changes in iron metabolism; indeed, plasma ferritin levels fall as a result of increased utilization of iron by the expanding erythroid marrow. The administration of epoetin alfa can therefore lead to a state of relative iron deficiency. Thus, iron supplementation is essential to maximize the effect of epoetin alfa-induced erythropoiesis.

No evidence of mitochondrial abnormality in skeletal muscle of patients with iron-deficient anaemia.

OBJECTIVES: Patients with iron deficiency anaemia complain of decreased exercise capacity. We asked whether this is due to defective oxidative ATP synthesis in skeletal muscle as a consequence of reduced blood oxygen content and/or intrinsic mitochondrial abnormalities. DESIGN: We used 31P magnetic resonance spectroscopy to examine skeletal muscle bioenergetics in iron-deficient patients and in age- and sex-matched controls. SETTING: The patients were recruited from the primary care population. SUBJECTS: We studied seven symptomatic female iron-deficient patients (aged 32-70 years) with haemoglobin (Hb) concentration, [Hb], 8.0 g dl-1. Six had menorrhagia, the cause in the seventh patient remained undiagnosed. Results were compared with those of 8 healthy female controls (aged 25-48 years) with mean [Hb] 13.7 g dl-1. RESULTS: The right calf muscle was by studied 31P magnetic resonance spectroscopy in a 1.9 T super-conducting magnet. We measured the intracellular concentrations of phosphocreatine (PCr), inorganic phosphate (Pi), adenosine triphosphate (ATP) and the intracellular pH at rest, during plantar flexion exercise and during recovery from exercise. Exercise duration was reduced in the patients, yet end-exercise PCr/(PCr+Pi) was higher and adenosine diphosphate (ADP) lower than in controls. After exercise, initial PCr recovery was slowed but this was probably because of the lower cytosolic ADP concentration. CONCLUSIONS: Mitochondrial ATP synthesis was not limited by oxygen supply or an intrinsic mitochondrial defect. Therefore, the reduced exercise capacity seen in iron deficiency could be due to central causes and not to skeletal muscle metabolic abnormalities.

Cause and cure for iron deficiency in toddlers.

Iron deficiency is the commonest cause of anaemia in Britain. Maureen B Duggan asks: How does toddler iron deficiency aris? How is it reliably diagnosed? And how can it be prevented in the community? Is iron supplementation of foods, especially of breast milk substitutes and follow-on formulae important in communities at risk?

[The prevention of congenital developmental anomalies in rats]. / Profilaktika vrozhdennykh anomalii razvitiia u krys.

Preventive administration of Eleutherococcus XXX extract during prenatal and pre-embryonic periods of development prevents embryotoxic effect of subsequent treatment of pregnant rats with ethanol and sodium salicylate. Eleutherococcus abolishes embryotoxic and teratogenic effects of ethanol manifested against the background of experimental syndrome of iron deficit in pregnant females. Mechanism of its antiteratogenic action is probably based on stimulation of cell detoxification mechanisms, increase in energy potential of cells, as well as on stabilization of structural and functional state of cell membranes.

Structure of dietary pectin, iron bioavailability and hemoglobin repletion in anemic rats.

The effects of the degree of esterification (DE) and the molecular weight (MW) of pectins on iron bioavailability were investigated in anemic rats. The pectins prepared differed (in DE and MW, respectively) as follows: P-A (73%, 860,000), P-B (75%, 89,000), P-C (22%, 1,260,000) and P-D (24%, 114,000). Rats were fed an iron-deficient diet (8 mg Fe/kg diet) for 14 d. The anemic rats were then fed a ferrous sulfate-supplemented basal diet (47 mg Fe/kg diet) or the basal diet containing one of the pectins (80 g/kg diet) for 10 d. None of the pectins used caused any significant reduction in the bioavailability of ferrous sulfate. Addition of pectin P-B to the diet resulted in significantly greater iron repletion. Compared with control rats fed with ad libitum access or pair-fed, rats fed P-B showed higher (P < 0.05) hemoglobin regeneration efficiency, hematocrit, serum iron concentration, and transferrin saturation, and lower unsaturated iron-binding capacity and total iron-binding capacity. Pectins P-A and P-D also slightly improved the hematological indices compared with P-C and control. The observed effects were dependent on the physicochemical properties of each pectin as determined by its MW and DE.

Effect of iron deficiency on small intestinal permeability in infants and young children.

Small intestinal absorptive function can be disturbed in iron deficiency. We examined the permeability behavior of the small intestinal mucosa toward lactulose and rhamnose in 26 otherwise healthy children with iron deficiency. Their (mean +/- SD) age was 21 +/- 8.6 months; hemoglobin 7.9 +/- 0.9 g/dl, mean corpuscular volume (MCV) 60.1 +/- 3.4 fl, serum iron 2.72 +/- 0.66 mumol/L, serum ferritin 7.3 +/- 1.6 micrograms/L. After an isotonic oral load of both sugars, their 5-h urinary excretion was measured by gas-liquid chromatography/mass spectrometry. The ratio of the percentage of urinary recovery of the sugars [lactulose/rhamnose (%)] was determined as the permeability index. The tests were repeated in the same subjects after 3 months of iron supplementation, and achievement of an iron sufficient state. In the iron-deficient state, the permeability index was significantly higher than the standard normal value (0.15 +/- 0.05 versus less than 0.07; p less than 0.01), but was not different from normal when the children had attained a normal iron status. The major factor for the alteration of the permeability index in the children with iron deficiency was a significantly lower urinary recovery of rhamnose (which passes the small intestinal epithelium by a transcellular route); the recovery of lactulose (which passes through a paracellular route) was not affected by iron deficiency. Our study indicates that iron deficiency in infants and young children can alter permeability characteristics of the small intestinal mucosa. Iron status should therefore be considered when interpreting permeability tests in the young.

[Iron deficiency in hospitalized infants: study of the incidence of the nutritional factor]. / La carence martiale chez le nourrisson hospitalisé: étude de l'incidence du facteur nutritionnel.

We report an investigation on the iron status of 209 hospitalized 3-month--2-year-old infants over a 6-month period. Hematological parameters and infant feeding practice were determined: a total of 105 infants (50.2%) were found to be iron-depleted, with (24.8%) or without (25.4%) anemia. The mode of lactation appeared to be the main determining factor in iron deficiency, as shown by the fact that during the first months, breast feeding and consumption of an iron-fortified milk formula were 50% less frequent and of shorter duration in infants with iron deficiency than in normal infants. Incorrect diet was also more frequent in iron-deficient infants. It is concluded that iron deficiency in infants could be prevented by better informing mothers in order to encourage breast-feeding and develop the use of an iron-fortified milk formula until the infant reaches the age of one year.

Inhibitory effect of dietary iron deficiency on the induction of putative preneoplastic foci in rat liver initiated with diethylnitrosamine and promoted by phenobarbital.

The effects of dietary iron deficiency on induction of putative preneoplastic, gamma-glutamyltransferase (GGT)-positive hepatocyte focal lesions in the liver of rats treated with diethylnitrosamine (DEN) followed by phenobarbital (PB) were investigated. Male Fischer 344 rats of 4 weeks old were placed on an iron deficient (ID) diet containing less than 5 p.p.m. of iron or an iron supplemented (IS) diet containing 180 p.p.m. of iron throughout experimental period of 12 weeks. Both groups of rats were administered 200 mg kg-1 body weight of DEN by a single intraperitoneal injection at Week 4 followed by PB mixed into each diet at a concentration of 0.05% from Week 6 to the final sacrifice at Week 12 when induction of GGT-positive foci was quantitatively analysed. On the ID and IS diets, respective numbers of GGT-positive foci were 6.3 and 14.2 cm-2. The sizes of foci were not altered by the iron content of the diet. The present results indicate that iron plays a role in the development of preneoplastic foci in the livers of rats initiated with DEN and promoted by PB especially in the initiation phase.

Altered metabolic response of iron-deficient women during graded, maximal exercise.

Metabolic responses during a standardized, progressive, maximal work capacity test on a cycle ergometer were studied in 11 women, mean age 28 (SEM 2) years, at admission to the study, after their body iron stores were depleted by diet, phlebotomy and menstruation for about 80 days and after iron repletion by diet for about 100 days, including daily iron supplementation (0.9 mmol iron as ferrous sulfate) for the last 14 days of repletion. Iron depletion was characterized by a decline (P less than 0.05) in hemoglobin, ferritin and body iron balance. Iron repletion, including supplementation, increased (P less than 0.05) hemoglobin, ferritin and iron balance. No changes were observed in cardiovascular and ventilatory responses or peak oxygen uptake. Iron depletion was associated with a reduced (P less than 0.05) rate of oxygen utilization, total oxygen uptake and aerobic energy expenditure, and elevated (P less than 0.05) peak respiratory exchange ratio and post-exercise concentration of lactate. Reduction of body iron stores without overt anemia affects exercise metabolism by reducing total aerobic energy production and increasing glycolytic metabolism.

[Effect of green tea on iron absorption in elderly patients with iron deficiency anemia].

The effect of green tea on iron absorption from tablets containing sodium ferrous citrate was investigated in four elderly patients with iron deficiency anemia and in eleven normal elderly subjects. In both groups, the serum iron level reached a maximum value from 2 to 4 hours after taking iron tablets and returned to the baseline value after 24 hours. No inhibitory effect of green tea on iron absorption was recognized.

Iron nutrition in childhood: the interplay of genes, development and environment.

The state of a child's iron nutrition depends on his genetic endowment, the stage of development he has reached and the environment in which he lives. Genetic disorders lead more commonly to iron overload than to deficiency. Generally interplay between genes and environment is apparently of little importance when considering iron deficiency; are we missing something? The greatest demands for iron are at the time of most rapid growth, i.e. during infancy and puberty, but during early infancy body stores can meet the demand without a need for dietary iron. Oxygen, diet and microbes are the important environmental factors related to iron nutrition. The relationship of oxygen toxicity to iron nutrition in the newborn has received only fleeting study, the availability of iron from many foods is unclear; the clinical significance of iron overload and deficiency in the evolution of an infection is also unclear despite a wealth of in vitro observation. I am not convinced that the bottle fed baby should receive iron in his diet during the first 4-6 months of life. Thereafter, while the concept of universal unselective supplementation causes some uneasiness there are considerable epidemiological arguments for fortification of food with iron.

Studies on the role of iron in zinc toxicity in chicks.

The interaction of dietary iron and zinc was studied in chicks. Zinc was found to be more toxic in iron-deficient animals than iron-supplemented animals as measured by hemoglobin concentrations and growth. Analyses of the kidney and liver for iron and zinc were carried out. As the level of iron was increased from 0-1000 ppm supplementation, the concentration of liver zinc increased. The organ levels of iron were decreased as the dietary zinc levels were increased from 0-5000 ppm. Radioisotope studies using 65Zn revealed that the iron content of the diet did not affect absorption of zinc. Administration of the isotope, either in an intestinal segment or intravenously, resulted in more zinc being taken up by the liver in the iron supplemented animals. This was especially noted when the ratio of the isotope in liver to that in the blood was compared. Gel chromatography of kidney and liver homogenates revealed that iron deficiency resulted in less zinc being eluted in a volume characteristic of metallothionein compared to homogenates of organs from iron supplemented animals. The results indicate that iron-supplemented animals have a greater capacity for sequestering zinc on metallothionein than do iron-deficient animals. Conversely, iron-deficient chicks were more susceptible to the effects of zinc toxicity than are iron-adequate chicks.

Studies on the role of iron in the reversal of cadmium toxicity in chicks.

Studies were conducted to determine the effect of dietary iron (Fe) levels ranging from a deficiency to an excess on the toxicity of cadmium (Cd) in chicks. In Fe-deficient animals, cadmium was found to be more toxic than in Fe supplemented animals as measured by growth. The liver Cd burdens were increased significantly in the presence of dietary Fe supplementation, and there was a significant Cd-Fe interaction in the Cd concentration of the kidney, indicating that iron deficiency increased the concentration of Cd in the kidneys of those chicks receiving this element. Cd tended to reduce the Fe concentration in both the liver and kidney. The absorption of Cd as measured by the amount of 109Cd that disappeared from an isolated duodenal segment in one h was not affected by the Fe content of the diet, but the amount of isotope appearing in the liver compared to the amount present in the blood was increased in the Fe supplemented chicks. Separation of the Cd binding ligands by column chromatography revealed that more of the Cd in the liver, but not the kidney, was associated with ligands which eluted in a column volume that contained metallothionein in those chicks receiving Fe than in the livers from Fe deficient animals. The inverse relationship between the amount of Cd bound to the metallothionein containing fraction and toxicity may be related causally.