Proteomic analysis and microRNA expression profiling of plasma-derived exosomes in primary immune thrombocytopenia

Exosome-Mediated Lectin Pathway and Resistin-MIF-AA Metabolism Axis Drive Immune Dysfunction in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by reduced platelet levels and heightened susceptibility to bleeding resulting from augmented autologous platelet destruction and diminished thrombopoiesis. Although antibody-mediated autoimmune reactions are widely recognized as primary factors, the precise etiological agents that trigger ITP remain unidentified. The pathogenesis of ITP remains unclear owing to the absence of comprehensive high-throughput data, except for the belated emergence of autoreactive antibodies. In this study, using flow cytometry (FCM), proteomics, and single-cell RNA sequencing of samples from patients with ITP, it is shown that exosome-mediated lectin complement pathway is involved in the pathogenesis of ITP, which triggers and enlarges the complement activation cascade without effective regulation because of downregulated CD55. The activated complement system enhances the immune response and resistin and further Macrophage Migration Inhibitory Factor (MIF) triggers several proinflammatory signaling pathways, which contribute to the survival of hyperactivated immune cells and dysfunctional arachidonic acid (AA) metabolism. The resistin and MIF are also identified as potential contributors to resistance to glucocorticoid therapy. Taken together, the findings indicate that the lectin pathway of the complement system, resistin, MIF, and AA metabolism may serve as promising targets for ITP treatment, offering novel perspectives on potential therapeutic interventions.

MicroRNA-199a-5p may be a diagnostic biomarker of primary ITP

There is no diagnostic test for primary immune thrombocytopenia (ITP). Certain microRNAs have shown to have diagnostic potential in ITP. We validated 12 microRNAs identified from two previous studies to find a diagnostic biomarker. The study included two ITP cohorts (n = 61) and healthy controls (n = 28). The first ITP cohort involved 24 patients from the Prolong study, patients with newly diagnosed/persistent ITP (<1 year) treated with corticosteroids ± IVIG but relapsed/failed to respond. The second cohort comprised 37 patients from ITP biobank, Østfold Hospital, Norway, patients had different disease stages and therapies. Twelve microRNAs were measured: miR-199a-5p, miR-33a-5p, miR-195-5p, miR-130a-3p, miR-144-3p, miR-146a-5p, miR-222-3p, miR-374b-5p, miR-486-5p, miR-1341-5p, miR-766-3p and miR-409-3p. miR-199a-5p, miR-33a-5p, miR-374b-5p, miR-146a-5p and miR-409-3p were expressed differentially in the entire ITP cohort compared to controls; of those only miR-199a-5p showed good discriminative ability between ITP and controls with area under the curve (AUC) of 0.718 (95% CI: 0.599-0.836). In the Prolong cohort (ITP < 1 year), miR-199a-5p and miR-374b-5p showed very good discriminative ability between ITP and controls with AUC of 0.824 (0.708-0.940) and 0.806 (0.688-0.924) respectively. This study confirmed that miR-199a-5p has good discriminative ability between primary ITP and healthy controls, thus may be a diagnostic biomarker of ITP.

Autoimmune effector mechanisms associated with a defective immunosuppressive axis in immune thrombocytopenia (ITP)

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by an isolated thrombocytopenia and variable phenotype as some patients suffer no bleeding whilst others have bleeding from mild to severe, which may be fatal. This variability probably reflects the disease's complex pathophysiology; a dysregulated hyperreactive immune effector cell response involving the entire adaptive immune system (e.g. B and T cell subsets) that leads to platelet and megakaryocyte (MK) destruction. It appears that these effector responses are due to a breakdown in immune tolerance, and this is characterized by defects in several immunosuppressive cell types. These include defective T regulatory cells (Tregs), B regulatory cells (Bregs) and Myeloid-derived suppressor cells (MDSC), all of which are all intimately associated with antigen presenting cells (APC) such as dendritic cells (DC). The loss of this immunosuppressive axis allows for the activation of unchecked autoreactive T cells and B cells, leading to the development of autoantibodies and cytotoxic T cells (CTL), which can directly destroy platelets in the periphery and inhibit MK platelet production in the bone marrow (BM). This review will focus on the effector cell mechanisms in ITP and highlight the defective immunosuppressive axis that appears responsible for this platelet-specific immune hyperreactivity.

Regulatory role of ceRNA network in B lymphocytes of patients with immune thrombocytopenia

OBJECTIVE

High-throughput sequencing was used to screen expressing differences of miRNA, lncRNA, and mRNA in CD19+ B peripheral blood samples of newly diagnosed immune thrombocytopenia (ITP) patients and healthy controls. The study aimed to explore the regulatory role of ceRNA network in the pathogenesis of dysfunctional CD19 + B lymphocytes of ITP patients.

METHODS

CD19+ B lymphocytes were isolated from peripheral blood samples of ITP patients and their healthy counterparts. High-throughput sequencing was used to screen for the expression of miRNA, lncRNA, and mRNA of ITP patients and healthy controls, which were analysed by the ceRNA network. Moreover, qPCR was used to verify the differential expression of miRNA, lncRNA, and mRNA in ITP patients and healthy controls. The correlation between differentially expressed miRNA, lncRNA, mRNA, and B lymphocyte subsets was also analysed.

RESULTS

The CD19+ B lymphocytes of 4 newly diagnosed ITP patients and 4 healthy controls were sequenced and analysed. There were 65 differentially expressed lncRNA and 149 mRNA forming a ceRNA network showed that 12 lncRNA and 136 differentially expressed mRNA were closely associated. Similarly, miR-144-3p, miR-374c-3p, and miR-451a were highly expressed in ITP patients, as confirmed by qPCR, which was consistent with the high-throughput sequence results. LOC102724852 and CCL20 were highly expressed in ITP patients, while LOC105378901, LOC112268311, ALAS2, and TBC1D3F were not as compared to healthy controls, which was consistent with the high-throughput sequence results. In addition, the expression of miR-374c-3p, LOC112268311, LOC105378901, and CXCL3 were correlated with the percentage of B lymphocyte subsets.

CONCLUSIONS

The ceRNA network of miRNA, lncRNA, and mRNA in peripheral CD19 + B lymphocytes plays an essential role in the pathogenesis of ITP.

Expression pattern of miR-16-2-3p and its prognostic values on pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is a debilitating illness that easily occurs in adolescents. microRNAs (miRNAs) are potential biomarkers for multiple diseases. This paper was to elaborate on the expression of miR-16-2-3p in childhood ALL and its clinical values on ALL diagnosis and prognosis. First, serum miR-16-2-3p expression in ALL children and healthy volunteers was measured using RT-qPCR. Next, diagnostic potential and prognostic values of miR-16-2-3p on ALL were analyzed through receiver operating characteristic (ROC) curve, Kaplan-Meier survival curve, and multivariate Cox regression analysis, respectively. No significant difference was observed in the clinical baseline data between ALL patients and healthy children. ALL patients showed downregulated serum miR-16-2-3p (0.65 ± 0.27) (p < .01), whose area under the ROC curve was 0.837 with a cut-off value of 0.745 (67.92% sensitivity, 96.94% specificity). ALL patients with higher miR-16-2-3p expression had higher survival rates than those with lower miR-16-2-3p expression. Low miR-16-2-3p expression predicted poor prognosis of ALL patients. After adjusting LDH and lymphomyelocyte proportion (p = 0.003, HR = 0.003, 95%CI = 0.000-0.145), miR-16-2-3p was recognized as an independent prognostic factor for ALL patient survival. Briefly, low serum miR-16-2-3p expression in ALL children could aid ALL diagnosis and predict poor prognosis.

The potential role of serum extracellular vesicle derived small RNAs in AML research as non-invasive biomarker

BACKGROUND

Extracellular vesicles (EV) are cell-derived vesicles released by all cells in health and disease. Accordingly, EVs are also released by cells in acute myeloid leukemia (AML), a hematologic malignancy characterized by uncontrolled growth of immature myeloid cells, and these EVs likely carry markers and molecular cargo reflecting the malignant transformation occurring in diseased cells. Monitoring antileukemic or proleukemic processes during disease development and treatment is essential. Therefore, EVs and EV-derived microRNA (miRNA) from AML samples were explored as biomarkers to distinguish disease-related patterns ex vivo or in vivo.

METHODOLOGY

EVs were purified from serum of healthy (H) volunteers and AML patients by immunoaffinity. EV surface protein profiles were analyzed by multiplex bead-based flow cytometry (MBFCM) and total RNA was isolated from EVs prior to miRNA profiling via small RNA sequencing.

RESULTS

MBFCM revealed different surface protein patterns in H versus AML EVs. miRNA analysis showed individual as well as highly dysregulated patterns in H and AML samples.

CONCLUSIONS

In this study, we provide a proof-of-concept for the discriminative potential of EV derived miRNA profiles as biomarkers in H versus AML samples.

Scoping Review on Epigenetic Mechanisms in Primary Immune Thrombocytopenia

Immune Thrombocytopenia (ITP) is an autoimmune blood disorder that involves multiple pathways responsible for the homeostasis of the immune system. Numerous pieces of literature have proposed the potential of immune-related genes as diagnostic and prognostic biomarkers, which mostly implicate the role of B cells and T cells in the pathogenesis of ITP. However, a more in-depth understanding is required of how these immune-related genes are regulated. Thus, this scoping review aims to collate evidence and further elucidate each possible epigenetics mechanism in the regulation of immunological pathways pertinent to the pathogenesis of ITP. This encompasses DNA methylation, histone modification, and non-coding RNA. A total of 41 studies were scrutinized to further clarify how each of the epigenetics mechanisms is related to the pathogenesis of ITP. Identifying epigenetics mechanisms will provide a new paradigm that may assist in the diagnosis and treatment of immune thrombocytopenia.

A bibliometric analysis of primary immune thrombocytopenia from 2011 to 2021

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia. This bibliometric analysis was applied to identify the characteristics of global scientific output, the hotspots, and frontiers of ITP over the past 10 years. We retrieved publications from 2011 to 2021 from the Web of Science Core Collection (WoSCC). Bibliometrix package, VOSviewer, and Citespace were used to analyse and visualize the trend, distribution, and hotspots of research on ITP. Altogether, there were 2084 papers, written by 9080 authors from 410 organizations in 70 countries/regions, published in 456 journals with 37 160 co-cited references. In the last decades, the most productive journal was British Journal of Haematology, China was the most productive country. and the most cited journal was Blood. Shandong University was the most productive institution in the field of ITP. NEUNERT C, 2011, BLOOD, CHENG G, 2011, LANCET, and PATEL VL, 2012, BLOOD were the top three most cited documents. "Thrombopoietin receptor agonist", "regulatory T cell" and "sialic acid" were three hotspots of the last decade. And "immature platelet fraction", "Th17", and "fostamatinib" would be research frontiers in the feature. The present study provided a novel insight for future research directions and scientific decision-making.

[Expression of miR-106b-5p in children with primary immune thrombocytopenia and its correlation with T cells]

OBJECTIVES

To study the expression level of plasma miR-106b-5p in primary immune thrombocytopenia (ITP) and its correlation with the levels of T helper 17 cell (Th17) and regulatory T cell (Treg) and the Th17/Treg ratio.

METHODS

A total of 79 children with ITP (ITP group) and 40 healthy children (control group) were selected as subjects. According to the treatment response, the 79 children with ITP were divided into three groups: complete response (n=40), partial response (n=18), and non-response (n=21). Quantitative real-time PCR was used to measure the expression level of miR-106b-5p. Flow cytometry was used to measure the frequencies of Th17 and Treg, and the Th17/Treg ratio was calculated. The correlation of the expression level of plasma miR-106b-5p with the frequencies of Th17 and Treg and the Th17/Treg ratio was analyzed.

RESULTS

Compared with the control group, the ITP group had significantly higher levels of miR-106b-5p, Th17, and Th17/Treg ratio (P<0.05) and a significantly lower level of Treg (P<0.05). After treatment, the ITP group had significant reductions in the levels of miR-106b-5p, Th17, and Th17/Treg ratio (P<0.05) and a significant increase in the level of Treg (P<0.05). Compared with the partial response and non-response groups, the complete response group had significantly lower levels of miR-106b-5p, Th17, and Th17/Treg ratio (P<0.05) and a significantly higher level of Treg (P<0.05). The correlation analysis showed that in the children with ITP, the expression level of plasma miR-106b-5p was positively correlated with the Th17 level and the Th17/Treg ratio (r=0.730 and 0.816 respectively; P<0.001) and was negatively correlated with the Treg level (r=-0.774, P<0.001).

CONCLUSIONS

A higher expression level of miR-106b-5p and Th17/Treg imbalance may be observed in children with ITP. The measurement of miR-106b-5p, Th17, Treg, and Th17/Treg ratio during treatment may be useful to the evaluation of treatment outcome in children with ITP.

The Extensive Regulation of MicroRNA in Immune Thrombocytopenia

MicroRNA (miRNA) is a small, single-stranded, non-coding RNA molecule that plays a variety of key roles in different biological processes through post-transcriptional regulation of gene expression. MiRNA has been proved to be a variety of cellular processes involved in development, differentiation, signal transduction, and is an important regulator of immune and autoimmune diseases. Therefore, it may act as potent modulators of the immune system and play an important role in the development of several autoimmune diseases. Immune thrombocytopenia (ITP) is an autoimmune systemic disease characterized by a low platelet count. Several studies suggest that like other autoimmune disorders, miRNAs are deeply involved in the pathogenesis of ITP, interacting with the function of innate and adaptive immune responses. In this review, we discuss emerging knowledge about the function of miRNAs in ITP and describe miRNAs in terms of their role in the immune system and autoimmune response. These findings suggest that miRNA may be a useful therapeutic target for ITP by regulating the immune system. In the future, we need to have a more comprehensive understanding of miRNAs and how they regulate the immune system of patients with ITP.

Dysregulated miR-222-3p in plasma exosomes of preeclampsia patients and its In vitro effect on HTR8/SVneo extravillous trophoblast cells by targeting STMN1

OBJECTIVE

To investigate the diagnostic efficiency of miR-222-3p in plasma exosomes (Exos) and plasma for preeclampsia (PE) and the effect of miR-222-3p targeting STMN1 in PE.

METHODS

MiR-222-3p levels in total plasma and plasma Exos were detected in PE patients and healthy controls. A bioinformatics database and dual-luciferase reporter assay were employed to verify the targeting relationship between miR-222-3p and STMN1. Trophoblast HTR-8/Svneo cells were transfected with miR-222-3p inhibitors with/without STMN1 shRNA, followed by MTT, wound healing and Transwell invasion assays. The mRNA and protein expressions were measured by qRT‒PCR and Western blotting, respectively.

RESULTS

MiR-222-3p levels in total plasma and plasma Exos were higher in PE patients than in healthy controls, particularly in severe PE patients. In addition, miR-222-3p levels in total plasma and plasma Exos from PE patients were positively correlated with diastolic and systolic blood pressure. The area under the curve (AUC) of miR-222-3p in total plasma for PE diagnostic efficiency was 0.798, with a sensitivity of 76.67% and specificity of 71.93%, while the AUC of miR-222-3p in plasma Exos was 0.708 (sensitivity: 61.67%; specificity: 78.95%). In vitro, miR-222-3p targeted STMN1 in HTR-8/Svneo cells. Low miR-222-3p expression reversed the inhibitory effect of STMN1 shRNA on the proliferation, invasion and migration of HTR/SVneo cells.

CONCLUSION

PE patients had increased miR-222-3p expression in total plasma and plasma Exos, which both have high diagnostic efficiency for PE. MiR-222-3p can target STMN1 to promote the proliferation, invasion and migration of HTR-8/Svneo cells and is a potential therapeutic target of PE.

Platelets in ITP: Victims in Charge of Their Own Fate?

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder. The pathophysiological mechanisms leading to low platelet levels in ITP have not been resolved, but at least involve autoantibody-dependent and/or cytotoxic T cell mediated platelet clearance and impaired megakaryopoiesis. In addition, T cell imbalances involving T regulatory cells (Tregs) also appear to play an important role. Intriguingly, over the past years it has become evident that platelets not only mediate hemostasis, but are able to modulate inflammatory and immunological processes upon activation. Platelets, therefore, might play an immuno-modulatory role in the pathogenesis and pathophysiology of ITP. In this respect, we propose several possible pathways in which platelets themselves may participate in the immune response in ITP. First, we will elaborate on how platelets might directly promote inflammation or stimulate immune responses in ITP. Second, we will discuss two ways in which platelet microparticles (PMPs) might contribute to the disrupted immune balance and impaired thrombopoiesis by megakaryocytes in ITP. Importantly, from these insights, new starting points for further research and for the design of potential future therapies for ITP can be envisioned.