Hepatitis B, Chronic ; immunology ; Humans ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; immunology

Immune thrombocytopenia (ITP) is a common acquired autoimmune hematological disorders. Platelet autoantibodies lead to the decrease of platelet production and (or) increase of its destruction. The latest researches showed that the abnormal tryptophan metabolism mediated by indoleamine-2, 3-dioxygenase(IDO) is related with the pathogenesis of ITP. The patients with ITP show less expression of IDO, reduction of Treg cells and increase of autoreactive T cells and autoantibodies. CTLA-4-Ig can improve the expression of IDO in the patients with ITP, which also can inhibit the proliferation and activation of self-reactive T cells. Thus, clarifying the abnormal tryptophan metabolism mediated by IDO may provide a new idea for improving the understand of the pathogenesis and treatment of ITP. This review focuses on reasearch progress of the tryptophan metabolism mediated by IDO and ITP.
Autoantibodies ; Blood Platelets ; Humans ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; Thrombocytopenia ; Thrombopoiesis ; Tryptophan

Cell Adhesion ; Cell Movement ; Cell Proliferation ; Hep G2 Cells ; Humans ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; genetics ; Transfection

Alkaptonuria ; diagnosis ; genetics ; therapy ; Homogentisate 1,2-Dioxygenase ; genetics ; Humans ; Infant ; Male

In the process of animal fat deposition, the proliferation and differentiation of pre-adipocytes and the change of lipid droplet content in adipocytes are regulated by a series of transcription factors and signal pathways. Although researchers have conducted in-depth studies on the transcriptional regulation mechanisms of adipogenesis, there are relatively few reports on post-transcriptional modification on mRNA levels. The modification of mRNA m⁶A regulated by methyltransferase, demethylase and methylation reading protein is a dynamic and reversible process, which is closely related to fat deposition in animals. Fat mass and obesity associated proteins (FTO) act as RNA demethylases that affect the expression of modified genes and play a key role in fat deposition. This article summarized the mechanism of FTO-mediated demethylation of mRNA m⁶A in the process of animal fat deposition, suggesting that FTO may become a target for effective treatment of obesity. Moreover, this review summarized the development of FTO inhibitors in recent years.
Adipocytes ; Adipogenesis/genetics* ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics* ; Animals ; Obesity/genetics* ; RNA, Messenger/genetics*

Obesity-associated protein (FTO) is an important m6A demethylase that regulates RNA methylation modification and can promote the proliferation of acute myeloid leukemia(AML) cells. FTO regulates the methylation level of AML through multiple cellular signaling pathways such as FTO/RARA/ASB2, FTO/m6A/CEBPA, and PDGFRB/ERK, and participates in the occurrence, development, treatment and prognosis of AML. At present, studies have found that a variety of inhibitors targeting FTO have shown good anti-leukemia effects, and the study of FTO will provide new ideas for the treatment of AML. This review focus on the mechanism of action of FTO in AML and the research progress of FTO inhibitors in AML.
Humans ; Methylation ; Leukemia, Myeloid, Acute/genetics* ; Prognosis ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism*

Recent studies have unequivocally established the link between FTO and obesity. FTO was biochemically shown to belong to the AlkB-like family DNA/RNA demethylase. However, FTO differs from other AlkB members in that it has unique substrate specificity and contains an extended C-terminus with unknown functions. Insight into the substrate selection mechanism and a functional clue to the C-terminus of FTO were gained from recent structural and biochemical studies. These data would be valuable to design FTO-specific inhibitors that can be potentially translated into therapeutic agents for treatment of obesity or obesity-related diseases.
AlkB Homolog 1, Histone H2a Dioxygenase ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO ; Amino Acid Motifs ; Animals ; Catalytic Domain ; DNA ; metabolism ; DNA Repair Enzymes ; metabolism ; Humans ; Methylation ; Obesity ; genetics ; Proteins ; chemical synthesis ; classification ; genetics ; RNA ; metabolism ; Substrate Specificity

Collagen is the major matrix protein in dermis and consists of proline and lysine, which are hydroxylated by prolyl hydroxylase (PH) and lysyl hydroxylase (LH) with cofactors such as vitamin C, oxygen, iron (Fe2+), ketoglutarate and silicon. The collagen degradation is regulated by matrix metalloproteinase-1 (MMP-1), of which is the major collagen-degrading proteinase whereas tissue inhibitors of metalloproteinase-1 (TIMP-1) bind to MMP-1 thereby inhibiting MMP-1 activity. In this study, we investigated the effects of vitamin C, silicon and iron on mRNA, protein expressions of PH, LH, MMP-1 and TIMP-1. The physiological concentrations of vitamin C (0-100 micrometer), silicon (0-50 micrometer) and iron (Fe2+:0-50 micrometer) were treated to human dermal fibroblast cells (HS27 cells) for 3 or 5days. The expression level of mRNA and protein was increased in not only PH but also LH when cells were incubated with vitamin C. A similar increase in LH mRNA or protein expression occurred when cells were incubated with silicon. Our results suggest that treatment of vitamin C and silicon increased mRNA and protein expression of PH and LH in human dermal fibroblast.
Ascorbic Acid ; Collagen ; Dermis ; Fibroblasts ; Humans ; Hydrogen-Ion Concentration ; Iron ; Lysine ; Matrix Metalloproteinase 1 ; Oxygen ; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase ; Procollagen-Proline Dioxygenase ; Proline ; RNA, Messenger ; Silicon ; Tissue Inhibitor of Metalloproteinase-1 ; Vitamins

Alkaptonuria is a rare metabolic disease in which homogentisic acid cannot be metabolized due to a lack of the enzyme homogentisic acid oxidase. The disease often manifests itself in childhood by darkening of the urine upon standing. The disease leads to such serious consequences as ochronosis of cartilage and connective tissues with arthritis. It is expected that treatment with ascorbic acid and a dietary restriction of protein may decrease the late and serious consequences by diminishing the serum concentration of the metabolite benzoquinone acetic acid. A thirteen month-old girl was recently diagnosed with alkaptonuria by urine organic acid analysis. She excreted pinkish urine on a diaper and as time went by the urine color changed to a light brown. In laboratory findings, urine examination and culture results were normal. But urine organic acid analysis detected abnormal findings a prominent and massive elevation of homogentisic acid. The other physical findings were normal. This is the first case diagnosed in Korea.
Acetic Acid ; Alkaptonuria* ; Arthritis ; Ascorbic Acid ; Cartilage ; Connective Tissue ; Female ; Homogentisate 1,2-Dioxygenase ; Homogentisic Acid ; Humans ; Korea* ; Metabolic Diseases ; Ochronosis

Munn et al. made a scientific observation of major biological importance. For the first time they showed that in the mammal the fetus does survive an immune attack mounted by the mother, and that the mechanism responsible for the survival depends on the fetus and placenta 'actively' defending itself from attack by maternal T cells by means of an enzyme indoleamine 2,3-dioxygenase (EC 1.13.11.42) dependent localised depletion of L-tryptophan. These findings raise critical questions for disease and its prevention during human pregnancy. Specifically, the role of this mechanism (discovered in mouse) in the human, and the extent to which defective activation of this process is responsible for major clinical diseases are unknown. Therefore some key facts about this enzyme expressed in the human placenta have been studied in order to test whether Munn et al.'s findings in mouse are met for human pregnancy. This short review attempts to describe our experimental work on human placental indoleamine 2,3-dioxygenase.
Animals ; Fetus ; Humans ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; Mammals ; Mice ; Mothers ; Placenta ; Pre-Eclampsia ; Pregnancy ; T-Lymphocytes ; Tryptophan