OBJECTIVETo study FANCA protein expression in Fanconi anemia patient's (FA) cells and explore its function.

METHODSFANCA protein expression was analyzed in 3 lymphoblast cell lines derived from 3 cases of type A FA (FA-A) patients using Western blot. Nucleus and cytoplasm localization of FANCA protein was analyzed in one case of FA-A which contained a truncated FANCA (exon 5 deletion). The FANCA mutant was constructed from the same patient and its interaction with FANCG was evaluated by mammalian two-hybrid (M2H) assay.

RESULTSFANCA protein was not detected in the 3 FA-A patients by rabbit anti-human MoAb, but a truncated FANCA protein was detected in 1 of them by mouse anti-human MoAb. The truncated FANCA could not transport from cytoplasm into nucleus. The disease-associated FANCA mutant was defective in binding to FANCG in M2H system.

CONCLUSIONSFANCA proteins are defective in the 3 FA-A patients. Disfunction of disease-associated FANCA mutant proved to be the pathogenic mutations in FANCA gene. Exon 5 of FANCA gene was involved in the interaction between FANCA and FANCG.

Cell Line ; Child ; Exons ; Fanconi Anemia ; genetics ; metabolism ; Fanconi Anemia Complementation Group A Protein ; genetics ; metabolism ; Humans ; Lymphocytes ; metabolism ; Male ; Mutation

Anemia of chronic disease (ACD), complicated by various chronic inflammatory diseases, is the second most prevalent type of anemia after iron deficiency anemia in the world. ACD significantly reduces the life quality of patients with chronic diseases, and represents an independent poor prognostic factor in certain chronic diseases. A large body of studies has demonstrated that most of anemia is related to abnormal iron metabolism. In the past decade, hepcidin, as a key factor in regulating iron metabolism, has attracted enormous attention due to its important role in the pathogenesis of ACD. This article reviews the research progress on the role and underlying regulatory mechanisms of hepcidin in ACD. We also discuss the potential of hepcidin as an effective therapeutic target for ACD treatment, in order to provide a new maneuver for improving the quality of ACD patients' life.
Anemia ; Anemia, Iron-Deficiency/pathology* ; Chronic Disease ; Hepcidins ; Humans ; Iron/metabolism*

Iron deficiency is the most common cause of anemia worldwide. The goal of therapy for iron deficiency anemia (IDA) is to supply sufficient iron to repair the hemoglobin deficit and replenish storage iron, combined with correction of underlying conditions. The majority of patients with IDA respond well to oral or parenteral iron replacement therapy if appropriately prescribed, but some rare cases of IDA refractory to both oral and parenteral iron replacement therapy due to in-born error of iron metabolism have been reported previously. We report here a mysterious case of IDA refractory to both oral and parenteral iron therapy and even to red cell transfusions. A 21-year-old male patient was admitted to our hospital due to general weakness and dizziness. His hemogram, iron profiles and bone marrow study showed the findings compatible with IDA. We could not find any conditions that cause acute or chronic blood loss, or any evidence of in-born error of iron metabolism. In spite of adequate iron relplacement therapy via both oral and parenteral routes, and even with red cell transfusions, his hemogram and iron profiles were not improved.
Anemia ; Anemia, Iron-Deficiency* ; Bone Marrow ; Dizziness ; Humans ; Iron* ; Male ; Metabolism ; Young Adult

OBJECTIVETo screen the FANCA gene mutation and explore the FANCA protein function in Fanconi anemia (FA) patients.

METHODSFANCA protein expression and its interaction with FANCF were analyzed using Western blot and immunoprecipitation in 3 cases of FA-A. Genomic DNA was used for MLPA analysis followed by sequencing.

RESULTSFANCA protein was undetectable and FANCA and FANCF protein interaction was impaired in these 3 cases of FA-A. Each case of FA-A contained biallelic pathogenic mutations in FANCA gene.

CONCLUSIONSNo functional FANCA protein was found in these 3 cases of FA-A, and intragenic deletion, frame shift and splice site mutation were the major pathogenic mutations found in FANCA gene.

Cell Line ; DNA Mutational Analysis ; Fanconi Anemia ; genetics ; metabolism ; Fanconi Anemia Complementation Group A Protein ; genetics ; metabolism ; Humans ; Mutation

Fanconi anemia (FA) is an autosomal or X-linked recessive disorder characterized by chromosomal instability, bone marrow failure, cancer susceptibility, and a profound sensitivity to agents that produce DNA interstrand cross-link (ICL). To date, 15 genes have been identified that, when mutated, result in FA or an FA-like syndrome. It is believed that cellular resistance to DNA interstrand cross-linking agents requires all 15 FA or FA-like proteins. Here, we review our current understanding of how these FA proteins participate in ICL repair and discuss the molecular mechanisms that regulate the FA pathway to maintain genome stability.
DNA Damage ; DNA Repair ; Exodeoxyribonucleases ; genetics ; metabolism ; Fanconi Anemia ; genetics ; metabolism ; pathology ; Fanconi Anemia Complementation Group N Protein ; Fanconi Anemia Complementation Group Proteins ; genetics ; metabolism ; Humans ; Nuclear Proteins ; genetics ; metabolism ; Recombinases ; genetics ; metabolism ; Tumor Suppressor Proteins ; genetics ; metabolism ; Ubiquitination

Anemia of chronic disease is normocytic and normochromic. One of the mechanisms is misbalance of iron metabolism. Hepcidin, a kind of protein secreted by liver is considered to be the hormone regulating iron metabolism. It binds to ferroportin and induces the latter one's internalization. Thus, iron transportation from iron storage cells to serum is reduced. Cytokines are elevated in chronic disease. They stimulate hepcidin expression in liver through JAK2/STAT3 pathway. As a result, iron absorption and reabsorption is blocked, which leads to the misbalance of iron metabolism in anemia of chronic disease. In this article, the hepcidin and its relation to iron metabolism and anemia in chronic disease are reviewed.
Anemia ; metabolism ; Antimicrobial Cationic Peptides ; metabolism ; Chronic Disease ; Hepcidins ; Humans ; Iron ; metabolism

We experienced a case of pyridoxine refractory hereditary sideroblastic anemia (HSA) in a 4 year-old girl and; therefore, conducted a study of her family. She was admitted to hospital for anemia, which was uncorrected by iron treatment. The peripheral blood smears showed hypochromic microcytic anemia. The results of the biochemical study indicated serum iron of 80 microgram/dL, TIBC of 275 microgram/dL and serum ferritin of 67ng/dL. The bone marrow smears showed 80% cellularity, with mild dyserythropoiesis. Many ringed sideroblasts, 45% of normoblasts and an increased amount of hemosiderin particles were observed with iron staining. Despite high-dose pyridoxine therapy, the anemia was not corrected. In the peripheral blood and iron studies conducted on her family members, the mother, maternal aunt and aunt's son showed microcytic hypochromic anemia and normal iron metabolism. Her mother's brother had died of acute myeloid leukemia that had transformed from myelodysplastic syndrome. From a search of the Korean literature, this is the first reported case of HSA with pedigree.
Anemia ; Anemia, Hypochromic ; Anemia, Sideroblastic* ; Bone Marrow ; Child, Preschool ; Erythroblasts ; Female ; Ferritins ; Hemosiderin ; Humans ; Iron ; Leukemia, Myeloid, Acute ; Metabolism ; Mothers ; Myelodysplastic Syndromes ; Pedigree ; Pyridoxine ; Siblings

The objective of this study was to explore the differences between refractory anemia with ringed sideroblast (RARS) and RARS associated with marked thrombocytosis (RARS-T) in the clinical, biological features and prognosis. The morphological changes of cells were observed by bone marrow smear and biopsy. Immunologic phenotype was analyzed by flow cytometry, and chromosome was examined by conventional chromosomal analysis. JAK2 V617F and MPL W515L mutations were screened by allele-specific polymerase chain reaction (AS-PCR) and sequence analysis. The results showed that this case was clinically diagnosed as RARS with thrombophilia, the level of serum potassium was positively related with platelet counts. When platelets increased, the clusters of atypical giant platelets and megakaryocytes were observed in peripheral blood and bone marrow examined by bone marrow smear and bone marrow biopsy respectively, JAK2 V617F and MPL W515L mutations were negative. It is concluded that RARS may transform into RARS-T accompanied with megakaryocyte proliferation, large atypical platelets and negative JAK2 V617F. Preventing thrombophilia and monitoring relative gene mutations are necessary when atypical giant platelets and fluctuant platelet counts occurred in process of RARS with tendency to RARS-T.
Aged ; Anemia, Refractory ; diagnosis ; metabolism ; pathology ; Anemia, Sideroblastic ; diagnosis ; pathology ; Blood Platelets ; pathology ; Female ; Humans ; Platelet Count ; Thrombocytosis ; pathology

The discovery of neuroglobin (Ngb), a brain- or neuron-specific member of the hemoglobin family, has revolutionized our understanding of brain oxygen metabolism. Currently, how Ngb plays such a role remains far from clear. Here, we report a novel mechanism by which Ngb might facilitate neuronal oxygenation upon hypoxia or anemia. We found that Ngb was present in, co-localized to, and co-migrated with mitochondria in the cell body and neurites of neurons. Hypoxia induced a sudden and prominent migration of Ngb towards the cytoplasmic membrane (CM) or cell surface in living neurons, and this was accompanied by the mitochondria. In vivo, hypotonic and anemic hypoxia induced a reversible Ngb migration toward the CM in cerebral cortical neurons in rat brains but did not alter the expression level of Ngb or its cytoplasm/mitochondria ratio. Knock-down of Ngb by RNA interference significantly diminished respiratory succinate dehydrogenase (SDH) and ATPase activity in neuronal N2a cells. Over-expression of Ngb enhanced SDH activity in N2a cells upon hypoxia. Mutation of Ngb at its oxygen-binding site (His⁶⁴) significantly increased SDH activity and reduced ATPase activity in N2a cells. Taken together, Ngb was physically and functionally linked to mitochondria. In response to an insufficient oxygen supply, Ngb migrated towards the source of oxygen to facilitate neuronal oxygenation. This novel mechanism of neuronal respiration provides new insights into the understanding and treatment of neurological diseases such as stroke and Alzheimer's disease and diseases that cause hypoxia in the brain such as anemia.
Rats ; Animals ; Neuroglobin/metabolism* ; Globins/metabolism* ; Nerve Tissue Proteins/metabolism* ; Neurons/metabolism* ; Hypoxia/metabolism* ; Brain/metabolism* ; Oxygen ; Anemia/metabolism* ; Adenosine Triphosphatases/metabolism*

OBJECTIVE: To explore the improvement effect of CXC chemokine receptor 4 (Cxcr4) gene-modified bone marrow mesenchymal stem cell (BMSC)-derived exosomes on aplastic anemia (AA), and make a preliminary exploration of the mechanism. METHODS: Mouse BMSCs were isolated and cultured, then infected by recombinant lentivirus carrying Cxcr4 gene. The expression of green fluorescence was observed through fluorescence microscope, the expression of Cxcr4 mRNA was detected by real-time fluorescence quantitative PCR, and the BMSC-derived exosomes modified with Cxcr4 gene were extracted. Mouse models of AA were constructed, and control group, model group (AA), AA+BMSC group, AA+NC-BMSC group, AA+Cxcr4-BMSC group were set up. Except control group and model group, the other three groups of mice were injected 400 μl exosomes from different sources via the tail vein, after 2 weeks, the routine blood indices and the number of bone marrow nucleated cells were detected, the pathological changes of bone marrow were observed by HE staining, and the expression level of Treg cells was detected by flow cytometry. RESULTS: Mouse BMSCs were successfully isolated, and BMSCs with high expression of Cxcr4 and their exosomes were obtained. Compared with the control group, the number of red blood cell (RBC), white blood cell (WBC), and platelet (PLT), the hemoglobin (Hb) content and proportion of Treg cells in the peripheral blood of mice in the model group significantly decreased (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01). The proliferation level of nucleated cells was low, and the medullary cavity was filled with a large number of fat cells. Compared with the model group, the number of RBC, WBC, PLT, the Hb content and proportion of Treg cells in the peripheral blood of mice in the AA+BMSC group, AA+NC-BMSC group, and AA+Cxcr4-BMSC group significantly increased (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01), and pathological changes of bone marrow were improved. In addition, the number of RBC, WBC, PLT, the Hb content and proportion of Treg cells in the peripheral blood of mice in the AA+Cxcr4-BMSC group were significantly higher than those in the AA+BMSC group (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01). CONCLUSION Injection of Cxcr4 gene-modified BMSC-derived exosomes has a certain improvement effect on AA mice, and the mechanism may be related to an increase of the proportion of Treg cells.
Anemia, Aplastic/metabolism* ; Animals ; Bone Marrow Cells ; Exosomes/metabolism* ; Humans ; Mesenchymal Stem Cells ; Mice ; Receptors, CXCR4