Identification of ORM1, vWF, SPARC, and PPBP as immune-related proteins involved in immune thrombocytopenia by quantitative LC-MS/MS.

BACKGROUND: Immune thrombocytopenia (ITP) is a common autoimmune disease characterized by loss of immune tolerance to platelet autoantigens leading to excessive destruction and insufficient production of platelets. METHOD: Quantitative liquid chromatography tandem mass spectrometry (LC-MS/MS) was performed to detect the differentially expressed proteins in bone marrow samples from active ITP patients and normal controls. RESULT: Our bioinformatic analysis identified two upregulated proteins (ORM1 and vWF) and two downregulated proteins (PPBP and SPARC) related to immune function. The four proteins were all found to be related to the tumor necrosis factor (TNF) -α signalling pathway and involved in the pathogenesis of ITP in KEGG pathway analysis. CONCLUSION: Bioinformatics analysis identified differentially expressed proteins in bone marrow that are involved in the TNF-α signalling pathway and are related to the activation of immune function in ITP patients. These findings could provide new ideas for research on the loss of immune tolerance in ITP patients.

Gene mutations in the PI3K/Akt signaling pathway were related to immune thrombocytopenia pathogenesis.

BACKGROUND: Immune thrombocytopenic (ITP) is an autoimmune bleeding disease with genetic susceptibility. Twenty newly diagnosed active primary ITP patients who had not been treated with glucocorticosteroids, immune globulin or immunosuppressants prior to sampling were enrolled in this study. Bone marrow blood mononuclear cells were used for whole exome sequencing to further elucidation the variant genes of ITP. METHODS: High-molecular-weight genomic DNA was extracted from freshly frozen bone marrow blood mononuclear cells from 20 active ITP patients. Next, the samples were subjected to molecular genetic analysis by whole-exome sequencing, and the results were confirmed by Sanger sequencing. The signaling pathways and cellular processes associated with the mutated genes were identified with gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. RESULTS: The results showed that there were 3998 missense mutations involving 2269 genes in more than 10 individuals. Unique genetic variants including phosphatase and tensin homolog, insulin receptor, and coagulation factor C homology were the most associated with the pathogenesis of ITP. Functional analysis revealed these mutation genes mainly affect Phosphatidylinositol 3 kinase/serine/threonine kinase B signaling pathways (signal transduction) and platelet activation (immune system). CONCLUSION: Our finding further demonstrates the functional connections between these variant genes and ITP. Although the substantial mechanism and the impact of genetic variation are required further investigation, the application of next generation sequencing in ITP in this paper is a valuable method to reveal the genetic susceptibility.

High-throughput DNA methylation analysis in ITP confirms NOTCH1 hypermethylation through the Th1 and Th2 cell differentiation pathways.

BACKGROUND: Immune thrombocytopenia (ITP) is a prevalent autoimmune disease with a complex aetiology where DNA methylation changes are becoming triggers. METHOD: To investigate novel abnormally methylated genes in the pathogenesis of ITP, we performed a high-throughput methylation analysis on 21 ITP patients and 9 normal control samples. We analysed the extent of key methylated genes and their downstream cytokines through Luminex assay or qRT-PCR. Then, bone marrow mononuclear cells were extracted from ITP patients, and decitabine (demethylation drug) was added to the culture medium of cultured cells. qRT-PCR and ELISA were used to detect whether decitabine could effectively affect target genes and related cytokines. RESULTS: Through the STRING and Metascape databases, hypermethylated NOTCH1 can be identified and can influence ITP by regulating many downstream cytokines through Th1 and Th2 cell differentiation pathways. Compared with those in the normal control group, the expression levels of NOTCH1 and its downstream Th2 cytokines (IL-4, IL-10, and GATA3) were significantly decreased and those of Th1 cytokines (IFN-γ, IL-12, and TNF-α) were significantly increased in the ITP group. Decitabine exerts its demethylation effect, so the expression of NOTCH1 and its related cytokines in the ITP group treated with 100 nM decitabine were significantly reversed. CONCLUSIONS: Our results suggest that the pathogenesis of ITP may exert its influence on epigenetics through alteration of DNA methylation at regulatory regions of the target NOTCH1 gene in the Th1 and Th2 cell differentiation pathways. At the same time, decitabine may achieve a therapeutic effect on ITP by demethylation.

Quantitative LC-MS/MS uncovers the regulatory role of autophagy in immune thrombocytopenia.

BACKGROUND: Immune thrombocytopenia (ITP) is an autoimmune haemorrhagic disease whose pathogenesis is associated with bone marrow megakaryocyte maturation disorder and destruction of the haematopoietic stem cell microenvironment. METHODS: In this study, we report the qualitative and quantitative profiles of the ITP proteome. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was conducted to elucidate the protein profiles of clinical bone marrow mononuclear cell (BMMC) samples from ITP patients and healthy donors (controls). Gene Ontology (GO) and Kyoto Encyclopaedia Genes and Genome (KEGG) pathway analyses were performed to annotate the differentially expressed proteins. A protein-protein interaction (PPI) network was constructed with the BLAST online database. Target proteins associated with autophagy were quantitatively identified by parallel reaction monitoring (PRM) analysis. RESULTS: Our approaches showed that the differentially expressed autophagy-related proteins, namely, HSPA8, PARK7, YWHAH, ITGB3 and CSF1R, were changed the most. The protein expression of CSF1R in ITP patients was higher than that in controls, while other autophagy-related proteins were expressed at lower levels in ITP patients than in controls. CONCLUSION: Bioinformatics analysis indicated that disruption of the autophagy pathway is a potential pathological mechanism of ITP. These results can provide a new direction for exploring the molecular mechanism of ITP.

Significant reductions in apoptosis-related proteins (HSPA6, HSPA8, ITGB3, YWHAH, and PRDX6) are involved in immune thrombocytopenia.

To investigate differences in the expression of plasma proteins in immune thrombocytopenia (ITP) and normal control groups, bone marrow samples were collected from 20 active ITP patients and 20 healthy controls. Quantitative proteomics analysis based on mass spectrometry was used to measure the protein levels and understand the protein networks. We found differentially expressed proteins in ITP patients and healthy controls. Parallel reaction monitoring (PRM), a targeted proteome quantification technique, was used to quantitatively confirm the identified target proteins and verify the proteomics data. In this study, a total of 829 proteins were identified, and the fold-change cut-off was set at 1.5 (patients vs controls); a total of 26 proteins were upregulated, and 69 proteins were downregulated. The bioinformatics analysis indicated that some differentially expressed proteins were associated with apoptosis. KEGG enrichment analysis showed that the apoptosis-related proteins were closely related to the PI3K-Akt signalling pathway. PRM demonstrated that apoptosis-related proteins were significantly decreased in ITP patients, which further confirmed the important effect of apoptosis on ITP pathogenesis. We hypothesised that apoptosis may be closely related to ITP pathogenesis through the PI3K-Akt signalling pathway.

Abnormal expression of autophagy-related proteins in immune thrombocytopenia.

Autophagy is a highly conserved protein degradation pathway that is essential for affecting some autoimmune diseases. Immune thrombocytopenia (ITP) is a common autoimmune disorder, and the complex dysregulation of cellular immunity has been observed; however, the relationship between autophagy-related proteins and immune responses in ITP remains unclear. Using real-time quantitative polymerase chain reaction (RT-PCR), the mRNA expression levels of Beclin-1, SQSTM1/p62 and LC3 were measured in the peripheral blood mononuclear cells (PBMCs) of 20 newly diagnosed patients with active ITP, 16 ITP patients in remission and 21 healthy volunteers. The stained Beclin-1 and SQSTM1/p62 proteins were also observed in the bone marrow of active ITP patients and normal controls by immunofluorescence. SQSTM1/p62 mRNA expression in PBMCs in newly diagnosed patients was significantly decreased. At the same time, Beclin-1 mRNA was increased significantly. During the remission stages, the levels of these autophagy-related proteins were comparable with those observed in healthy controls. Taken together, these results suggest that the aberrant expression of autophagy-related proteins might be involved in the pathogenesis of ITP. Further study of the autophagy pathway may provide a new strategy and direction for the treatment of ITP.

Immunomodulatory cytokine interleukin-35 and immune thrombocytopaenia.

Considerable attention has been paid to interleukin (IL)-35 because of its immunosuppressive effects in a variety of autoimmune diseases. IL-35, a recently identified cytokine of the IL-12 family, is a negative regulatory factor secreted by IL-35-inducible regulatory T cells (iTr35 cells) and the recently reported regulatory B cells (Breg cells). Four biological effects of IL-35 have been discovered in vitro and in vivo: (i) suppression of T cell proliferation; (ii) conversion of naive T cells into iTr35 cells; (iii) downregulation of type 17 helper T (Th17) cells; and (iv) conversion of Breg cells into a Breg subset that produces IL-35 and IL-10. IL-35 plays an important role in a variety of autoimmune diseases, such as rheumatoid arthritis, allergic asthma and systemic lupus erythematosus. Primary immune thrombocytopaenia (ITP), which is characterized by isolated thrombocytopaenia and mild mucocutaneous to life-threatening bleeding, is an autoimmune disease with complex dysregulation of the immune system. Both antibody-mediated and/or T cell-mediated platelet destruction are key processes. In addition, impairment of T cells and cytokine imbalances have now been recognized to be important. This review summarizes the immunomodulatory effects of IL-35 and its role in the pathogenesis of ITP as mediated by T and B cells.

Mucin mutations and aberrant expression are associated with the pathogenesis of immune thrombocytopenia.

PURPOSE: Primary immune thrombocytopenia (ITP) is an acquired autoimmune disease of unknown aetiology. In this study, we aimed to identify the mutations and aberrant expression of mucins associated with ITP pathogenesis. METHODS: First, we investigated the DNA mutation profile of bone marrow samples from patients with ITP (n = 20) by using next-generation sequencing (NGS). In addition, MUC3A, MUC5B and MUC6 were mutated in all patients with ITP. ELISA (enzyme-linked immunoassay) was used to measure MUC3A, MUC5B and MUC6 levels in the plasma of bone marrow fluid mononuclear cells (BMMCs) and peripheral blood mononuclear cells (PBMCs). Real-time quantitative PCR was used to study the mRNA expression levels of MUC3A, MUC5B and MUC6 in BMMCs and PBMCs. RESULTS: The results indicated that there were 3998 missense mutations involving 2269 genes in more than 10 individuals. MUC3A levels were not significantly different among the three groups, whereas MUC5B and MUC6 expression were significantly down-regulated in patients with ITP compared with healthy controls. In addition, serum MUC5B and MUC6 levels were significantly higher in patients with ITP in clinical remission than in patients with active ITP. CONCLUSIONS: Taken together, these results suggest that genetic alterations and the aberrant serum expression of mucins might be involved in the pathogenesis of ITP.

Reduced IL-35 in patients with immune thrombocytopenia.

: The occurrence and development of primary immune thrombocytopenia is closely related to autoimmune imbalanced. Thus, we conducted the current study to investigate the modulation of IL-35, a newly identified immunological self-tolerance factor on immune thrombocytopenic purpura (ITP). We were enrolled peripheral blood in 21 adult healthy volunteers, 21 active primary ITP patients and 16 ITP patients in remission. In the same period, bone marrow plasma was drawn from active primary ITP patients and 16 bone marrow donors. Enzyme-linked immunoassay was used to measure IL-35 levels in bone marrow mononuclear cells and peripheral blood mononuclear cells. Real-time quantitative PCR was used to study the mRNA expression levels of p35, Epstein-Barr virus-induced gene 3 in bone marrow mononuclear cells and peripheral blood mononuclear cells. Compared with the normal group, IL-35 levels of in ITP patients were decreased significantly. IL-35 level in bone marrow plasma was decreased more significantly than that in peripheral blood plasma at the same stage. The results showed that plasma IL-35 levels were significantly decreased in patients with active ITP compared with those of control individuals, and IL-35 levels in bone marrow plasma were decreased more significantly compared with those at the same stage. The pathogenesis of ITP is associated with decreased IL-35 levels. Further studies are needed to expand sample content and explore more in-depth investigate a possible role of IL-35 in the pathogenesis and course of ITP.

Rapamycin induces megakaryocytic differentiation through increasing autophagy in Dami cells.

: Autophagy is a conserved cellular process that involves the degradation of cytoplasmic components in eukaryotic cells. However, the correlation between autophagy and megakaryocyte development is unclear. This study aims to explore the role of autophagy in megakaryocyte differentiation. To test our hypothesis, we used the Dami cell line in-vitro experiments. Rapamycin and Bafilomycin A1 were used to stimulate Dami cells. CD41 expression and apoptosis were analysed by flow cytometry. Autophagy-related proteins were detected by Western blotting. 12-O-Tetradecanoylphorbol 13-acetate-treated Dami cells can simulate endomitosis of megakaryocytes in vitro. Rapamycin-induced autophagic cell death was verified by LC3-II conversion upregulation. Meanwhile, Bafilomycin A1 blocked endomitosis and autophagy of Dami cells. Our results provide evidence that autophagy is involved in megakaryocyte endomitosis and platelet development. Rapamycin inhibited cell viability and induced multiple cellular events, including apoptosis, autophagic cell death, and megakaryocytic differentiation, in human Dami cells. Upregulated autophagy triggered by rapamycin can promote the differentiation of Dami cells, while endomitosis is accompanied by enhanced autophagy.

DNA methylation plays an important role in immune thrombocytopenia.

DNA methylation is the covalent addition of a methyl group to a DNA base, typically the cytosine of cytosine-phosphate-guanosine (CpG) dinucleotides. It is catalysed by methyltransferase enzymes using an S-adenosyl methionine donor, which is a heritable, stable and reversible DNA modification. Aberrant DNA methylation can influence gene expression without changing nucleotide sequences, inducing occurrence and development in autoimmune diseases, such as systemic lupus erythematosus and immune thrombocytopenia. Immune thrombocytopenia is an autoimmune disease characterised by bleeding and thrombocytopenia of peripheral blood, a normal or increased number of megakaryocytes and a maturation disorder. Recently, it was proven that aberrant DNA methylation is associated with the aetiology of immune thrombocytopenia. The defective methylation induces overexpression of methylation-related genes, such as CD70 and FOXP3, which can take part in autoreactive immune responses, and ultimately accelerated the progression of immune thrombocytopenia. Targeting the DNA methylation can be used as a new treatment for immune thrombocytopenia. As a demethylated drug, decitabine promotes megakaryocyte maturation and platelet release under the action of tumour necrosis factor-related apoptosis inducing ligand (TRAIL) promoter. This review highlights recent evidence on the role of DNA methylation in immune thrombocytopenia by describing the relationship between DNA methylation and immune thrombocytopenia, and the DNA methylation-related genes. Identifying and regulating abnormal DNA methylation provides new ideas for the diagnosis and treatment of immune thrombocytopenia.

Research Progress on Artemisinin and Its Derivatives against Hematological Malignancies.

Although current therapeutic methods against hematological malignancies are effective in the early stage, they usually lose their effectiveness because of the development of drug resistances. Seeking new drugs with significant therapeutic effects is one of the current research hotspots. Artemisinin, an extract from the plant Artemisia annua Linne, and its derivatives have excellent antimalarial effects in clinical applications as well as excellent safety. Recent studies have documented that artemisinin and its derivatives (ARTs) also have significant effects against multiple types of tumours, including hematological malignancies. This review focuses on the latest research achievements of ARTs in the treatment of hematological malignancies as well as its mechanisms and future applications. The mechanisms of ARTs against different types of hematological malignancies mainly include cell cycle arrest, induction autophagy and apoptosis, inhibition of angiogenesis, production of reactive oxygen species, and induction of differentiation. Additionally, the review also summarizes the anticancer effects of ARTs in many drug-resistant hematological malignancies and its synergistic effects with other drugs.

Blockade of T-cell immunoglobulin and mucin domain-containing molecule 3 aggravates T-helper cell 1 polarization in immune thrombocytopenia.

: An increased T-helper cell (Th) 1/Th2 ratio in the peripheral blood has been proposed to correlate with the disease activity of immune thrombocytopenia (ITP). T-cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) is a Th1-associated cell surface molecule that regulates Th1 responses and promotes tolerance. Consequently, we aimed to determine whether the regulation of TIM-3 expression is likely to be a promising therapeutic approach for ITP. In the present study, we investigated the immunomodulatory activities of TIM-3 in human peripheral blood mononuclear cell (PBMC) cultures. Levels of interferon-gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-4, IL-5, IL-2, and IL-10 were determined in PBMCs from 11 ITP patients and 10 healthy patients after TIM-3 antibody administration for 48 h. The proliferation of PBMCs was examined by cell counting kit-8 assay. Flow cytometry was used to observe apoptosis by staining cells with annexin V-fluorescein isothiocyanate/propidine iodide. PBMCs from ITP patients secreted higher amounts of IFN-γ than those from control patients but paradoxically expressed lower levels of TIM-3. Depletion of TIM-3 in PBMCs in vitro using a TIM-3 antibody enhanced IFN-γ secretion, directly demonstrating that TIM-3 expression on human T cells regulates proliferation and IFN-γ secretion. Failure to upregulate the T-cell expression of TIM-3 may represent a novel intrinsic defect that contributes to the pathogenesis of ITP.

Megakaryocytic dysfunction in immune thrombocytopenia is linked to autophagy.

Immune thrombocytopenic purpura (ITP) is a multifactorial autoimmune disease characterized by both increased platelet destruction and/or reduced platelet production. Even though they are detected in ≤ 50% of ITP patients, auto-antibodies play a pivotal role in the pathogenesis of ITP. Recent experimental and clinical observations have revealed abnormal autophagy in ITP patients. Autophagy is a catabolic process responsible for the elimination and recycling of cytoplasmic constituents, such as organelles and macromolecules, in eukaryotic cells. Additionally, it triggers cell death or promotes cell survival following various forms of stress, and maintains the microenvironment and stemness of haematopoietic stem cells. The role of autophagy in megakaryopoiesis, thrombopoiesis, and platelet function is slowly being uncovered. The abnormal autophagy in ITP patients may be caused by deletion of autophagy-related genes such as ATG7 and abnormal signalling due to overexpression of mTOR. These changes are thought to affect markers of haematopoietic stem cells, such as CD41 and CD61, and differentiation of megakaryocytes, ultimately decreasing the function and quantity of platelets and leading to the onset of ITP. This review highlights recent evidence on the essential role played by autophagy in megakaryopoiesis, megakaryocyte differentiation, thrombopoiesis, and platelet production. It also discusses the potential of targeting the autophagy pathway as a novel therapeutic approach against ITP.

Targeting autophagy as a potential therapeutic approach for immune thrombocytopenia therapy.

Autophagy involves the sequestration and lysosomal degradation of various cytoplasmic structures, including damaged organelles and invading microorganisms. Autophagy is not only an essential cell-intrinsic mechanism for protecting against internal and external stress conditions but is also key in the cellular response against microbes, in antigen processing for major histocompatibility complex (MHC) presentation, and in lymphocyte development, survival, and proliferation. In recent years, perturbations in autophagy have been implicated in a number of diseases, including autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS). Immune thrombocytopenia (ITP) is a multifactorial disease characterized by autoimmune responses to self-platelet membrane proteins. Recently, our unpublished original data demonstrated aberrant expression of molecules in the autophagy pathway in ITP patients compared with controls, and we found a close correlation between the pathogenesis of ITP and the autophagy pathway. The potential of targeting the autophagy pathway in ITP as a novel therapeutic approach has been discussed.

Decreased expression of IL-33 in immune thrombocytopenia.

PURPOSE: Interleukin-33 (IL-33) is an IL-1 family cytokine which signals via its ST2 receptor and is involved in several autoimmune diseases by regulating T cell immune responses. This study aims to measure the expression of soluble ST2 (sST2) and IL-33 in active immune thrombocytopenia (ITP) and during remission. METHODS: Thirty-two ITP patients with active disease and 20 patients in remission were studied. IL-33 and sST2 were measured in plasma using ELISA and compared with 27 age- and sex-matched healthy controls. Real-time quantitative PCR was used to determine IL-33 and sST2 mRNA expressions. RESULTS: The IL-33 level in plasma was significantly down-regulated in the patients with active ITP (P<0.01). The sST2 level was up-regulated (P<0.01) in the patients with active ITP compared with ITP in remission and the normal controls. No significant changes were detected between the patients with ITP in remission and the normal controls. We detected an obvious up-regulation of sST2 mRNA levels but no change in IL-33 mRNA expression. There was no correlation observed between IL-33 or sST2 expression and the platelet count of the patients with active ITP. The plasma and mRNA level ratios of sST2/IL-33 were up-regulated in the active disease patients (P<0.01). However, no difference was detected between the ITP patients with remission disease and healthy controls. CONCLUSIONS: The values of sST2 and IL-33 observed in patients with ITP correlated with disease activity. Considering the role of IL-33 in regulating T cell immunity, studies on IL-33 and sST2 in ITP would further improve our understanding of the pathogenesis of ITP.

Altered expression of T cell Immunoglobulin-Mucin (Tim) molecules in peripheral blood mononuclear cells in aplastic anemia.

To evaluate the balance between T-cell immunoglobulin and mucin domain (Tim) molecules(Tim)-1 and Tim-3 in patients with aplastic anemia (AA), plasma IFN-γ and IL-4 levels were measured in patients with active AA (n = 41), AA in remission (n = 29) and in healthy subjects (n = 40) by enzyme linked immunosorbent assay (ELISA). Using real-time quantitative polymerase chain reaction (RT-PCR), the mRNA expression of IFN-γ, IL-4, Tim-1 and Tim-3 were studied in all subjects. The results showed that the expression of Tim-3 in newly diagnosed patients was significantly deceased, compared with the controls. Meanwhile, Tim-1 mRNA expression in the active AA group was not significantly reduced, which resulted in a declined ratio of Tim-3/Tim-1 in patients with active disease. During the remission stages, the levels of these transcription factors were comparable with those observed in the healthy controls. These findings are the first data on the expression of the Tim-1 and Tim-3 molecules in AA. The reduced levels of Tim-3/Tim-1 in PBMCs during the active stages of disease suggest that they may play a possible role in the pathogenesis and course of AA.

[JAK2V617F mutation and TNF-α expression in myeloproliferative neoplasms and their correlation].

This study was aimed to explore the JAK2V617F mutation and TNF-α expression in patients with myeloproliferative neoplasm (MPN), and the relation between them so as to provide theoretical basis for clinical practice and target therapy. Sixty-two confirmed BCR-ABL-negative MPN patients and 15 healthy adults were enrolled in this study. The peripheral blood mononuclear cells of the patients and healthy controls were divided into two parts, one part was used to extract DNA, the other one was used to extract mRNA and reverse-transcribe into cDNA. Real-time fluorescent quantitative PCR was used to detect JAK2V617F mutation proportion and the expression level of TNF-α. The results showed that the positive rate of JAK2V617F mutation in MPN patients was 64.52% (40/62) , including 54.28% in essential thrombocythemia (ET) patients (19/35), 94.74% in polycythemia vera (PV) patients (18/19) and 37.50% in myelofibrosis (MF) (3/8) patients. Mutation proportions of JAK2V617F in ET, PV and MF patients were 0.838 ± 0.419, 4.417 ± 0.658, 2.746 ± 2.009 respectively. The expression of TNF-α in ET, PV and MF patients were higher than that in healthy controls: 1.7, 7.0, 8.2-fold (P < 0.05) respectively. In addition, TNF-α expression was correlated with JAK2V617F allele burden (Pearson r = 0.610,R(2) = 0.372,P = 0.005). It is concluded that TNF-α plays an important role in the pathogenesis of MPN, the TNF-α expression increases and is different in ET,PV and MF patients,which correlates with JAK2V617F allele burden.

Reduced tumour necrosis factor receptor superfamily 13C inversely correlated with tumour necrosis factor superfamily 13B in patients with immune thrombocytopenia.

To investigate the expression of tumour necrosis factor superfamily 13B (TNFSF13B) receptors in immune thrombocytopenia (ITP) and their correlation with disease activity, we investigated the protein and mRNA levels of TNFSF13B, tumour necrosis factor receptor superfamily 13C (TNFRSF13C), TNFRSF13B and TNFRSF17 by flow cytometry, enzyme-linked immunosorbent assay and real time quantitative polymerase chain reaction. All CD19(+) B lymphocytes expressed TNFRSF13C by flow cytometry, but the mean fluorescence intensity (MFI) was decreased in patients with active disease compared to patients in remission and healthy controls, while no significant difference of TNFRSF13C mRNA was found between ITP patients and controls. The mRNA and plasma TNFSF13B were elevated in active ITP patients, and TNFRSF13C MFI level was inversely correlated with plasma TNFSF13B in active patients. In vitro assays showed that TNFRSF13C MFI was decreased after long exposure to TNFSF13B. No significant difference for TNFRSF13B or TNFRSF17 was found between ITP patients and controls. In conclusion, TNFRSF13C expression is reduced on CD19(+) cells in active ITP patients. This down-regulation occurs through a post-transcriptional mechanism and could be a consequence of chronic increase of TNFSF13B.

Imbalanced expression of human Tim-1 and Tim-3 in peripheral blood mononuclear cells from immune thrombocytopenia patients.

BACKGROUND: The T-cell immunoglobulin and mucin domain-(Tim)-1 molecule and Tim-3 are mainly expressed on activated T helper (Th) 2 and Th1 cells, respectively, and have been implicated in the pathogenesis of some autoimmune diseases. Immune thrombocytopenia (ITP) is a common autoimmune disorder, and the complex dysregulation of cellular immunity has been observed; however, the relationship between Tims and excessive immune responses in ITP remains unclear. METHODS: Using real-time quantitative polymerase chain reaction (RT-PCR), the mRNA expression levels of Tim-1, Tim-3, T-box transcription factor (T-bet) and GATA binding protein 3 (GATA-3) were measured in the peripheral blood mononuclear cells (PBMCs) of 45 newly diagnosed patients with active ITP, 34 ITP patients in remission and 31 healthy volunteers. RESULTS: Tim-3 mRNA expression in PBMCs in newly diagnosed patients was significantly decreased. At the same time, Tim-1 mRNA was not significantly declined, which resulted in a decreased ratio of Tim-3 to Tim-1 in ITP patients with active disease. During the remission stages, the levels of these transcription factors were comparable with those observed in healthy controls. CONCLUSIONS: The reduced levels of Tim-3/Tim-1 in PBMCs during active stages of the disease suggest a possible role in the pathogenesis and course of ITP. Regulating the balance of Tim-1 and Tim-3 in ITP patients could also be a therapeutic approach against ITP.