Inactivation of Notch signaling reverses the Th17/Treg imbalance in cells from patients with immune thrombocytopenia

Cellular and molecular mechanisms of Notch signal in pulmonary microvascular endothelial cells after acute lung injury

This study focused on the effect and mechanism of Notch signal on pulmonary microvascular endothelial cells (PMVECs) following acute lung injury. PMVECs were cultured in vitro and randomly divided into eight groups. Grouping was based on whether cells were co-cultured with T cells (splenic CD4+T cells were isolated using MACS microbeads) and the level of Notch expression: Normal group and Normal+T cells group, Model group and Model+T cells group, Notch low-expression group and Notch low-expression+T cells group, and Notch overexpression group and Notch overexpression+T cells group. Except for the Normal group and Normal+T cells group, all other groups were treated with 500 μL lipopolysaccharide (1 μg/mL). The expression of VE-cadherin and Zo-1 protein in the Model group (with or without T cells) was lower than that in the normal group (with or without T cells), their expression in the Notch low-expression group (with or without T cells) was significantly increased, and their expression in the Notch overexpression group (with or without T cells) was significantly decreased. Compared with the normal+T cells group, the number of Treg cells in the Notch low-expression+T cells group decreased significantly (P<0.01). The number of Th17 cells in the Notch overexpression+T cells group was higher than that in the Model+T cells group (P<0.01), while the number of Treg cells decreased (P<0.01). Our results demonstrated that activated Notch signal can down-regulate the expression of the tight junction proteins VE-Cadherin and Zo-1 in PMVECs and affect Th17/Treg immune imbalance. Autophagy was discovered to be involved in this process.

Immunomodulatory functions of microorganisms in tissue regenerative healing

External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a crucial regulatory role in this process. This review summarises our current understanding of microorganism-immune system interactions, with a focus on how these interactions impact the renewal and repair ability of tissues, including skin, bone, gut, liver, and nerves. This review concludes with a discussion of the mechanisms by which microbes act on various types of immune cells to affect tissue regeneration, offers potential strategies for using microbial therapies to enhance the regenerative repair function of tissues, and suggest novel therapeutic approaches for regenerative medicine. STATEMENT OF SIGNIFICANCE: Microbiological communities have crucial impacts on human health and illness by participating in energy collection and storage and performing various metabolic processes. External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a critical regulatory role in this process. This study reviews the important correlation between microorganisms and the immune system and investigates the mechanism of various microorganism that participate in the regeneration and repair of tissues and organs by modulating immune system.

Significance of NotchScore and JAG1 in predicting prognosis and immune response of low-grade glioma

Introduction

Low-grade glioma (LGG) is a prevalent malignant tumor in the intracranial region. Despite the advancements in treatment methods for this malignancy over the past decade, significant challenges still persist in the form of drug resistance and tumor recurrence. The Notch signaling pathway plays essential roles in many physiological processes as well as in cancer development. However, the significance of the pathway and family genes in LGG are poorly understood.

Methods

We conducted gene expression profiling analysis using the TCGA dataset to investigate the gene set associated with the Notch signaling pathway. we have proposed a metric called "NotchScore" that quantifies the strength of the Notch signaling pathway and enables us to assess its significance in predicting prognosis and immune response in LGG. We downregulated JAG1 in low-grade gliomas to assess its influence on the proliferation and migration of these tumors. Ultimately, we determined the impact of the transcription factor VDR on the transcription of PDL1 through chip-seq data analysis.

Results

Our findings indicate that tumors with a higher NotchScore, exhibit poorer prognosis, potentially due to their ability to evade the anti-tumor effects of immune cells by expressing immune checkpoints. Among the genes involved in the Notch signaling pathway, JAG1 has emerged as the most representative in terms of capturing the characteristics of both NotchScore and Notch pathways. The experimental results demonstrate that silencing JAG1 yielded a significant decrease in tumor cell proliferation in LGG cell lines. Our study revealed mechanisms by which tumors evade the immune system through the modulation of PDL1 transcription levels via the PI3K-Akt signaling pathway. Additionally, JAG1 potentially influences PDL1 in LGG by regulating the PI3K-Akt signaling pathway and the expression of the transcription factor VDR.

Discussion

These findings contribute to our understanding of immune evasion by tumors in LGG. The insights gained from this research may have implications for the development of therapeutic interventions for LGG.

Resveratrol inhibits AhR/Notch axis and reverses Th17/Treg imbalance in purpura by activating Foxp3

Background

Resveratrol has been reported to reverse the imbalance of T helper 17/regulatory T (Th17/Treg) by inhibiting the aryl hydrocarbon receptor pathway to treat immune thrombocytopenia. However, the regulation mechanism of the Notch signaling pathway by resveratrol has not been reported in purpura. This study is aimed to explore the mechanism of resveratrol ultrafine nanoemulsion (Res-mNE) in immune thrombocytopenia.

Methods

The immune thrombocytopenia mouse model was constructed to explore the effect of RES-mNE on immune thrombocytopenia. Cluster of differentiation 4 (CD4+) T cells were isolated and treated with different medications. CD4+ T cells were induced to differentiate into Th17 cells and Treg cells. Flow cytometry was used to detect the proportion of Th17 cells and Treg cells. The secretion was measured by the enzyme-linked immunosorbent assay (ELISA). Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and western blot were used to detect the mRNA and protein levels.

Results

Th17 cells, IL-17A and IL-22 increased in the immune thrombocytopenia mouse model, and the Treg cells and IL-10 decreased. Res-mNE promoted Treg cell differentiation and IL-10 secretion in CD4+ T cells while inhibiting Th17 cell differentiation and IL-17A and IL-22 levels. The AhR activator 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) reversed the effect of Res-mNE. Notch inhibitors reduced the ratio of Th17/Treg differentiation. Res-mNE activated the expression of Foxp3 by mediating AhR/Notch signaling to reverse the imbalance of Th17/Treg differentiation in immune thrombocytopenia.

Conclusion

Taken together, our findings demonstrated that RES-mNE inhibited the AhR/Notch axis and reversed Th17/Treg imbalance by activating Foxp3.

Regulatory factors involved in Th17/Treg cell balance of immune thrombocytopenia

Immune thrombocytopenia is a common heterogeneous autoimmune disease that is characterized by decreasing peripheral blood platelet counts and increasing risk of bleeding. Studies have shown that an imbalance between T helper 17 (Th17) and Regulatory T (Treg) cells differentiated from CD4+T-cells is a key factor influencing the development and pathogenesis of immune thrombocytopenia. Th17 cells promote the development of chronic inflammatory disorders and induce autoimmune diseases, whereas Treg cells regulate immune homeostasis and prevent autoimmune diseases. Several regulators affecting the production and maintenance of these cells are also essential for proper regulation of Th17/Treg balance; these regulatory factors include cell surface proteins, miRNAs, and cytokine signaling. In this review, we focus on the function and role of balance between Th17 and Treg cells in immune thrombocytopenia, the regulatory factors, and therapeutic goals of this balance in immune thrombocytopenia.

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.

Astragaloside Ⅳ alleviates ulcerative colitis by regulating the balance of Th17/Treg cells

BACKGROUND

Restoring immune homeostasis by targeting the Th17/Treg response is a potentially valuable therapeutic strategy for ulcerative colitis (UC). Astragaloside IV (AS-Ⅳ) is a phytochemical naturally occurring in Astragalus membranaceus that has good anti-inflammatory, anti-oxidant and anti-stress properties. However, the effects of AS-IV on the homeostasis of Th17/Treg cells in colitis mice remains unknown.

PURPOSE

To investigate the protective effects and potential immunomodulatory mechanisms of AS-IV on UC.

METHODS

This study was constructed for DSS-induced acute colitis and recurrent colitis, with AS-IV administered prophylactically and therapeutically, respectively. The balance of Th17/Treg cells was analyzed by flow cytometry, their specific nuclear transcription factors were detected by RT-PCR as well as their secreted inflammatory cytokines were detected by ELISA and RT-PCR. Notch signaling-related proteins were detected by RT-PCR and Western blotting. Oxidative stress indicators were measured by biochemical technology.

RESULTS

In this study, AS-IV treatment not only effectively prevented and alleviated the clinical symptoms of DSS-induced colitis mice, including weight loss, DAI soaring, colon length shortening and colon weight gain, but also significantly improved ulcer formation, inflammatory cell infiltration and index, and regulated the expression of inflammatory cytokines in colon tissues. Importantly, the efficacy of high-dose AS-IV (100 mg/kg/day) in mice with recurrent colitis in this study was comparable to that of 5-ASA. AS-IV early administration was able to reshape the homeostasis of Th17/Treg cells in mice with acute colitis; meanwhile, AS-IV inhibited Th17 cell responses and promoted Treg cell responses in mice with recurrent colitis. Moreover, AS-IV not only inhibited the activation of Notch signaling pathway in colitis mice, but also prevented and ameliorated DSS-induced oxidative stress injury.

CONCLUSION

In conclusion, AS-IV effectively prevented and alleviated UC by reshaping Th17/Treg cell homeostasis and anti-oxidative stress.

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.

Role of IL-10 and IL-22 cytokines in patients with primary immune thrombocytopenia and their clinical significance

BACKGROUND

Immune thrombocytopenia purpura (ITP) is an autoimmune disease that leads to accelerated platelet clearance. The objective of this study was to examine the clinical role of cytokines in ITP patients and to correlate them with disease stages.

MATERIALS AND METHODS

A total of 110 ITP patients were enrolled, including 55 with active ITP, 55 with remission ITP, and 55 with healthy controls. The enzyme-linked immunosorbent assay technique was used to examine IL-10 and IL-22 serum levels in all subjects. Real-time quantitative PCR was used to assess the mRNA expression of IL-10 and IL-22 in PBMC. The clinical significance of both cytokines was assessed using ROC analysis.

RESULTS

IL-10 serum levels in active ITP patients were significantly lower than in control and remission ITP subjects (p < 0.05). IL-22 serum levels were elevated in active ITP patients compared to the control and remission group (p < 0.05). mRNA expressions of IL-10 and IL-22 in active ITP patients were also having a significant difference from than control and remission ITP group (p < 0.05). ROC analysis showed that IL-10 and IL-22 can differentiate the ITP patients from controls. A positive correlation between serum IL-10 and PBMC IL-10 with statistical significance was observed. Similarly, the serum IL-22 and PBMC IL-22 were correlated positively with statistical significance.

CONCLUSION

IL-10 and IL-22 seem to predict the clinical course of ITP, as a significant imbalance of these cytokines was detected in active ITP patients.

Intrauterine administration of peripheral blood mononuclear cells (PBMCs) improves embryo implantation in mice by regulating local Treg/Th17 cell balance

Immune imbalance of Treg/Th17 cells may contribute to recurrent implantation failure (RIF) during in vitro fertilization and embryo transfer (IVF-ET). In this study, we sought to determine the effect of intrauterine administration of mouse PBMCs prior to embryo implantation on endometrial receptivity and embryo implantation, and examine the underlying mechanism of Treg/Th17 cell balance following intrauterine administration of PBMCs. Pregnant mice were randomly divided into three groups: control group, embryo implantation dysfunction (EID) group, and EID with PBMCs group, and the number of embryo implantation sites was recorded during early pregnancy (Pd7.5). The balance of Treg/Th17 cells in the peripheral blood, spleen, and local implantation sites was detected during the peri-implantation period (Pd4.0) and early pregnancy (Pd7.5). The EID group demonstrated a significant decrease in the number of embryo implantation sites, while the EID with PBMCs group demonstrated higher number of embryo implantation sites compared to the EID group. The balance of Treg/Th17 cells in the peripheral blood and spleen tissues was not significantly different between the aforementioned groups. However, the local uterine ratio of the Treg/Th17 cells increased in the EID with PBMCs group compared to that in the EID group. Collectively, we found that intrauterine administration of PBMCs prior to embryo implantation effectively promotes embryo implantation rates. This may be attributed to the improvement in the local immune balance of Treg and Th17 cells compared with the overall immune balance.

TGF-β-induced CD4+ FoxP3+ regulatory T cell-derived extracellular vesicles modulate Notch1 signaling through miR-449a and prevent collagen-induced arthritis in a murine model

CD4⁺FOXP3⁺ Treg cells are central to the maintenance of self-tolerance and can be defective in autoimmunity. In autoimmune rheumatic diseases, dysfunctional self-tolerance, is to a large extent, caused by insufficient Treg-cell activity. Although nTregs have therapeutic effects in vivo, their relative scarcity and slow rate of in vitro expansion hinder the application of nTreg therapy. It was previously reported that EVs contribute significantly to the suppressive function of FOXP3⁺ Treg cells. Considering that the stability and plasticity of nTregs remain major challenges in vivo, we established EVs derived from in vitro TGF-β-induced Treg cells (iTreg-EVs) and assessed their functions in a murine model of autoimmune arthritis. The results demonstrated that iTreg-EVs preferentially homed to the pathological joint and efficiently prevented the imbalance in Th17/Treg cells in arthritic mice. Furthermore, we found that miR-449a-5p mediated Notch1 expression modulation and that miR-449a-5p knockdown abolished the effects of iTreg-EVs on effector T cells and regulatory T cells in vitro and in vivo. Taken together, our results show that iTreg-EVs control the inflammatory responses of recipient T cells through miR-449a-5p-dependent modulation of Notch1 and ameliorate the development and severity of arthritis, which may provide a potential cell-free strategy based on manipulating iTreg-EVs to prevent autoimmune arthritis.

Decreasing lncRNA PVT1 causes Treg/Th17 imbalance via NOTCH signaling in immune thrombocytopenia

Objectives: Immune thrombocytopenia (ITP) is an autoimmune disease. T helper cell 17 (Th17) cells are increased in peripheral blood of ITP patients. NOTCH signaling is involved in Th17 cell differentiation and function. Besides, lncRNA Plasmacytoma variant translocation 1 (PVT1) was decreased in experimental autoimmune encephalomyelitis, and overexpressing PVT1 inhibited Th17 cell differentiation. Here, we aimed to investigate the effect of lncRNA PVT1 on ITP and its related mechanism.Methods: The number of Th17 cells and Treg cells was carried out using flow cytometry. PVT1 levels were detected by quantitative real-time PCR. Interleukin-17 (IL-17) levels and transforming growth factor-β (TGF-β) levels were detected by enzyme-linked immunosorbent assay. Protein levels of retinoid acid-related orphan receptor γ t (RORγt), forkhead box P3 (Foxp3), and NOTCH1 were carried out by western blot. NOTCH1 ubiquitylation was detected by ubiquitination assay.Results: PVT1 was down-regulated and Th17 cells were up-regulated in ITP patients. Overexpression of PVT1 decreased the number of Th17 cells, and also decreased the levels of IL-17, RORγt, and NOTCH1. Besides, PVT1 could bind to NOTCH1 and mediated NOTCH1 degradation by increasing its ubiquitination. Additionally, excessive expression of PVT1 could increase the levels of PVT1, reduce the amount of Th17 cells, as well as the levels of IL-17, RORγt, and NOTCH1, while co-overexpressing NOTCH1 reversed the results.Conclusion: PVT1 was down-regulated in ITP patients. Overexpressing PVT1 might reduce Th17 cell differentiation by down-regulating NOTCH1, and further alleviated the development of ITP.

Regulation of Th1/Th2 and Th17/Treg by pDC/mDC imbalance in primary immune thrombocytopenia

This study investigates the regulatory effect of plasmacytoid dendritic cells (pDC)/myeloid dendritic cells (mDC) imbalance on balance of Th1/Th2 and Th17/Treg in primary immune thrombocytopenia (ITP). A total of 30 untreated ITP patients and 20 healthy controls were recruited. Compared with healthy control, the pDC proportion of ITP patients was significantly reduced (P = 0.004), while the mDC proportion was not significantly changed (P = 0.681), resulting in a decrease in the pDC/mDC ratio (P = 0.001). Additionally, compared with controls, serum levels of interleukin (IL)-6, IL-12, and IL-23 were increased in ITP patients (P < 0.001), and mRNA levels of IL-12p40, IL-12p35, and IL-23p19 were also increased (P =0.014, P = 0.043, P < 0.001). Compared with the healthy control, the proportion of Th1 and Th17 cells in ITP patients increased (P = 0.001, P = 0.031). Serum levels of interferon gamma (IFN-γ) and IL-17 in ITP patients also increased (P = 0.025, P = 0.005). Furthermore, T-bet and RORγt mRNA levels were increased in peripheral blood of ITP patients (P = 0.018, P < 0.001). Correspondingly, the proportion of Th2 and Treg cells decreased (P = 0.007, P < 0.001), along with a decrease in serum IL-4 and transforming growth factor beta (TGF-β) (P = 0.028, P = 0.042), and an increase in GATA-3 mRNA (P < 0.001). However, there was no significant difference in Foxp3 mRNA levels (P = 0.587). Pearson correlation analysis showed that the proportion of total dendritic cells (DCs) was positively correlated with IL-12 (r = 0.526, P = 0.003) and IL-23 (r = 0.501, P = 0.005) in ITP patients. Th1/Th2 ratio, IFN-γ, and IL-12 levels were negatively correlated with platelet counts (r = -0.494, P = 0.009; r = -0.415, P = 0.028; r = -0.492, P = 0.032). However, IL-23 was positively correlated with IL-17 (r = 0.489, P = 0.006) and negatively correlated with platelet count (r = -0.564, P = 0.001). The ratio of IL-6 and Th17 cells was negatively correlated with platelet count (r = -0.443, P = 0.014; r = -0.471, P = 0.011). The imbalance of pDC/mDC and the increase of IL-6, IL-12, and IL-23 lead to the increased differentiation of CD4+ T cells into Th1 and Th17 cells, which might be the important mechanisms underlying the imbalance of Th1/Th2 and Th17/Treg in ITP patients.

Predicting bleeding risk in a Chinese immune thrombocytopenia (ITP) population: development and assessment of a new predictive nomogram

The aim of this study was to develop a model that could be used to forecast the bleeding risk of ITP based on proinflammatory and anti-inflammatory factors. One hundred ITP patients were recruited to build a new predictive nomogram, another eighty-eight ITP patients were enrolled as validation cohort, and data were collected from January 2016 to January 2019. Four demographic characteristics and fifteen clinical characteristics were taken into account. Eleven cytokines (IFN-γ, IL-1, IL-4, IL-6, IL-8, IL-10, IL-17A, IL-22, IL-23, TNF-α and TGF-β) were used to study and the levels of them were detected by using a cytometric bead array (CBA) human inflammation kit. The least absolute shrinkage and selection operator regression model was used to optimize feature selection. Multivariate logistic regression analysis was applied to build a new predictive nomogram based on the results of the least absolute shrinkage and selection operator regress ion model. The application of C-index, ROC curve, calibration plot, and decision curve analyses were used to assess the discrimination, calibration, and clinical practicability of the predictive model. Bootstrapping validation was used for testing and verifying the predictive model. After feature selection, cytokines IL-1, IL-6, IL-8, IL-23 and TGF-β were excluded, cytokines IFN-γ, IL-4, IL-10, IL-17A, IL-22, TGF-β, the count of PLT and the length of time of ITP were used as predictive factors in the predictive nomogram. The model showed good discrimination with a C-index of 0.82 (95% confidence interval 0.73376-0.90 624) in training cohortn and 0.89 (95% CI 0.868, 0.902) in validation cohort, an AUC of 0.795 in training cohort, 0.94 in validation cohort and good calibration. A high C-index value of 0.66 was reached in the interval validation assessment. Decision curve analysis showed that the bleeding risk nomogram was clinically useful when intervention was decided at the possibility threshold of 16-84%. The bleeding risk model based on IFN-γ, IL-4, IL-10, IL-17A, IL-22, TGF-β, the count of PLT and the length of time of ITP could be conveniently used to predict the bleeding risk of ITP.

The Role of Th17/Treg Axis in the Traditional Chinese Medicine Intervention on Immune-Mediated Inflammatory Diseases: A Systematic Review

The Th17/Treg axis plays a crucial role in immune-mediated inflammatory diseases (IMID) and might represent an interesting drug target of treatment strategy for these diseases. Accumulating evidence suggests a role for traditional Chinese medicine (TCM) in the modulation of Th17/Treg axis, but a comprehensive overview which summarizes this field hitherto is lacked. This paper performs a systematic literature review of the regulatory effects of TCM on the imbalance of Th17/Treg axis and its potential mechanisms. In addition, the frequency analysis and network pharmacology for the collected TCM herbs from clinical trial data were performed. The studies reported the changes in the ratio of Th17 and/or Treg cells as well as their transcription factor and related cytokines were included. Frequency analysis of composition of the 39 assessed TCM prescriptions showed that Astragalus membranaceus var.mongholicus (5.20%), Glycyrrhiza uralensis (3.67%), Paeonia obovate (3.06%), Salvia digitaloides (3.06%), and Angelica sinensis (2.75%) were the top five herbal components, which were closely associated to the treatment of IMID. Network pharmacology showed that six target proteins (transforming growth factor (TGF)-beta receptor type-1, TGF-beta receptor type-2, retineic-acid-receptor-related orphan nuclear receptor gamma (ROR-gamma), TGFB2, IL-17 and IL-2, respectively) might be involved in the regulatory effects of TCM on Th17/Treg axis. Moreover, there were nine active ingredients (including Oxymatrine, Baicalin, Triptolide, Paeoniflorin, Sinomenine, Celastrol, Emodin, Diosgenin and Chlorogenic acid) originating from TCM reported to have an immunological regulation effect on the Th17/Treg axis. The highlight of this systematic review is to reveal the pharmacological basis of TCM treating IMID and is helpful for supporting future pharmacologic-driven studies. Further research elucidates the immune-modulating mechanisms on Th17/Treg axis by TCM might provide a broader insight for the treatment of IMID.

miR-106b-5p induces immune imbalance of Treg/Th17 in immune thrombocytopenic purpura through NR4A3/Foxp3 pathway

BACKGROUND

Immune imbalance of regulatory T cells (Treg)/T helper 17 cells (Th17) contributes to the development of immune thrombocytopenic purpura (ITP). The dysregulation of miRNAs is important in the development of ITP. However, the role of miR-106b-5p in Treg/Th17 imbalance remains unknown in ITP.

MATERIALS AND METHODS

Peripheral blood was collected from patients with ITP and healthy controls, and CD4 + T cells were further isolated. miR-106b-5p, nuclear receptor subfamily 4 group A member 3 (NR4A3), forkhead box protein 3 (Foxp3), IL-17A, and TGF-β expressions were detected by qRT-PCR, western blot, or ELISA. The effect of miR-106b-5p on NR4A3 was detected by dual-luciferase reporter gene assay.

RESULTS

Compared with healthy controls, miR-106b-5p was elevated in peripheral blood of patients with ITP, and NR4A3 expression was decreased. sh-NR4A3 significantly decreased Foxp3 and TGF-β expressions, indicating that NR4A3 may regulate Treg differentiation via Foxp3. Additionally, NR4A3 was identified to be a target of miR-106b-5p, and miR-106b-5p was able to negatively modulate NR4A3 expression. Moreover, we found miR-106b-5p induced immune imbalance of Treg/Th17 through NR4A3. In vivo experiments revealed that silencing miR-106b-5p promoted Treg differentiation and increased the number of platelets, suggesting the relief of ITP.

CONCLUSION

miR-106b-5p regulated immune imbalance of Treg/Th17 in ITP through the NR4A3/Foxp3 pathway.

Protein Kinase C Theta Inhibition Attenuates Lipopolysaccharide-Induced Acute Lung Injury through Notch Signaling Pathway via Suppressing Th17 Cell Response in Mice

Acute lung injury (ALI)/acute respiratory distress syndrome is characterized by increased pulmonary inflammation, where T helper 17 (Th17) cells play an important regulatory role. Notch signaling critically regulates Th17 differentiation and is known to be linked with proximal T cell by protein kinase C theta (PKCθ). We hypothesized that PKCθ inhibition could attenuate ALI by suppressing Th17 response via the Notch signaling pathway. Male C57BL/6 mice were treated with phosphate-buffered saline (PBS), lipopolysaccharide (LPS), LPS and N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT, a Notch signaling inhibitor), or LPS and PKCθ inhibitor (PI), and the bronchoalveolar lavage fluid (BALF), blood, and lung tissues were harvested at 48 h after the LPS challenge. CD4⁺ T cells were treated with DAPT or PI and harvested after 72 h. PKCθ inhibition markedly attenuated pathological changes and decreased the wet to dry weight ratio of the mouse lungs. The total cell and neutrophil counts, tumor necrosis factor-α (TNF- α) in BALF, myeloperoxidase activity in lung tissue, and the leukocyte count in whole blood were markedly reduced by PKCθ inhibition. The concentration of interleukin (IL)-17 and IL-22 in BALF, and the percentage of CD4⁺IL-17A⁺ T cells in the lungs were significantly downregulated by PKCθ inhibition. A similar trend was observed for the expression of retinoic acid-related orphan receptor gamma t and IL-23 receptor after PKCθ inhibition accompanied with inactivation of the Notch signaling pathway in vivo and in vitro. Collectively, these data demonstrated that PKCθ inhibition protects against LPS-induced ALI by suppressing the differentiation and pathogenicity of Th17, at least partially, through a Notch-dependent mechanism.

LncRNA GAS5 inhibits Th17 differentiation and alleviates immune thrombocytopenia via promoting the ubiquitination of STAT3

BACKGROUND

The increased differentiation of T helper 17 cells (Th17) accelerates the development of immune thrombocytopenia (ITP), which is a common autoimmune disease with limited therapeutic methods. Recent studies have revealed that long non-coding RNAs (lncRNAs) play a critical role in autoimmune diseases, thus this study aims to investigate the effect of lncRNA GAS5 on the differentiation of Th17 cells in ITP.

METHODS

The expression of GAS5 in peripheral blood mononuclear cells (PBMCs) of ITP patients and spleen tissues of ITP mice was measured by qRT-PCR. The percentage of Th17 cells in CD4⁺ cells was measured by flow cytometry. The combination between GAS5 and STAT3 was confirmed by RNA pull-down assay and RNA Binding Protein Immunoprecipitation (RIP). The ubiquitination of STAT3 was detected by ubiquitination assay and the interaction between STAT3 and TRAF6 was measured by Co-Immunoprecipitation (Co-IP). Finally, the effect of GAS5 on Th17 differentiation was investigated in vitro and in vivo using lentivirus (lenti)-GAS5.

RESULTS

GAS5 expression was downregulated both in PBMCs of ITP patients and spleen tissues of ITP mice. Overexpression of GAS5 suppressed Th17 differentiation while had no effect on Treg differentiation in naïve CD4⁺ cells. RNA pull-down and RNA immunoprecipitation assays confirmed the interaction between GAS5 and STAT3. Further studies showed GAS5 accelerated the degradation of STAT3 via promoting TRAF6-mediated ubiquitination. Overexpressing GAS5 suppressed Th17 differentiation in vitro and alleviated ITP in vivo via reducing STAT3.

CONCLUSION

LncRNA GAS5 inhibited Th17 differentiation through promoting the TRAF6-mediated ubiquitination of STAT3, thus relieving ITP.

The Role of Classical and Novel Forms of Vitamin D in the Pathogenesis and Progression of Nonmelanoma Skin Cancers

Nonmelanoma skin cancers including basal and squamous cell carcinomas (SCC and BCC) represent a significant clinical problem due to their relatively high incidence, imposing an economic burden to healthcare systems around the world. It is accepted that ultraviolet radiation (UVR: λ = 290-400 nm) plays a crucial role in the initiation and promotion of BCC and SCC with UVB (λ = 290-320 nm) having a central role in this process. On the other hand, UVB is required for vitamin D3 (D3) production in the skin, which supplies >90% of the body's requirement for this prohormone. Prolonged exposure to UVB can also generate tachysterol and lumisterol. Vitamin D3 itself and its canonical (1,25(OH)2D3) and noncanonical (CYP11A1-intitated) D3 hydroxyderivatives show photoprotective functions in the skin. These include regulation of keratinocyte proliferation and differentiation, induction of anti-oxidative responses, inhibition of DNA damage and induction of DNA repair mechanisms, and anti-inflammatory activities. Studies in animals have demonstrated that D3 hydroxyderivatives can attenuate UVB or chemically induced epidermal cancerogenesis and inhibit growth of SCC and BCC. Genomic and non-genomic mechanisms of action have been suggested. In addition, vitamin D3 itself inhibits hedgehog signaling pathways which have been implicated in many cancers. Silencing of the vitamin D receptor leads to increased propensity to develop UVB or chemically induced epidermal cancers. Other targets for vitamin D compounds include 1,25D3-MARRS, retinoic orphan receptors α and γ, aryl hydrocarbon receptor, and Wnt signaling. Most recently, photoprotective effects of lumisterol hydroxyderivatives have been identified. Clinical trials demonstrated a beneficial role of vitamin D compounds in the treatment of actinic keratosis. In summary, recent advances in vitamin D biology and pharmacology open new exciting opportunities in chemoprevention and treatment of skin cancers.

Inhibiting the Notch signaling pathway suppresses Th17-associated airway hyperresponsiveness in obese asthmatic mice

Notch signaling is crucial for the regulation of asthma and obesity. The interleukin (IL)-17-expressing CD4⁺ T cell (Th17 cell) response and airway hyperresponsiveness (AHR) are critical features of both asthma and obesity. We previously demonstrated that inhibiting the Notch signaling pathway alleviates the Th17 response in a mouse model of asthma. However, obese asthmatic individuals show increased Th17 responses and AHR, with the underlying mechanism not currently understood. We aimed to assess the function of Notch signaling in obese mice with asthma and to determine the impact of a γ-secretase inhibitor (GSI), which inhibits the Notch signaling pathway, on the regulation of the Th17 response and AHR. C57BL/6 mice were administered ovalbumin (OVA) to induce asthma, while a high-fat diet (HFD) was used to induce mouse diet-induced obesity (DIO). GSI was then administered intranasally for 7 days in DIO-OVA-induced mice. The results showed increased Notch1 and hes family bHLH transcription factor 1 (Hes1) mRNA levels and Notch receptor intracellular domain (NICD) protein levels in obese asthmatic mice. Furthermore, these mice showed an increased proportion of Th17 cells, serum IL-17A, IL-6, and IL-1β levels, mucin 5AC (MUC5AC) mRNA level, retinoic acid-related orphan receptor-γt (RORγt) mRNA and protein levels, and increased AHR severity. Interestingly, GSI treatment resulted in reduced Notch1 and Hes1 mRNA and NICD protein levels in DIO-OVA-induced mice, with a decreased Th17 cell proportion and IL-17A quantity and alleviated AHR. These data strongly indicate that the Notch pathway is critical in obese asthmatic mice. In addition, inhibiting the Notch pathway ameliorates AHR and the Th17 response in obese mice with asthma.

A new NOTCH3 damaging variant in a thrombocytopenia family of Miao ethnic group

BACKGROUND

Pediatric inherited thrombocytopenia, also known as a deficiency of platelets in children, is caused by genetic factors and it is hard to obtain an effective treatment. Thus, it is necessary to identify the possible genetic variants that are responsible for thrombocytopenia.

METHODS

Whole exome sequencing was used to detect genetic variants in two members of a thrombocytopenia family of Miao ethnic group. Multiple in silico analyses were performed to evaluate the effects of the novel missense variants.

RESULTS

Finally, a novel variant (chr19: g.15170364G>A) in the NOTCH3 gene was found, as confirmed with Sanger sequencing, which could result in a R1694Q substitution in the protein. This variant was consistently suggested to be damaging by sift (Sorting Tolerant From Intolerant; http://sift.jcvi.org), polyphen (Polymorphism Phenotyping, version 2.0; http://genetics.bwh.harvard.edu/pph2) and mutationtaster (http://www.mutationtaster.org) software. By building the 3D model of the key region of NOTCH3 protein and performing the structure simulation, we found that (i) this variant affected the 3D structure model with a root-mean-square deviation = 0.46 between wild-type and mutant type; (ii) this variant caused the protein to reduce the solvent accessible surface area by 421 Å² ; and (iii) compared to the wild-type protein, the mutant protein had two less amino acids to maintain protein stability.

CONCLUSIONS

A novel damaging variant in the NOTCH3 gene was identified in a thrombocytopenia family with respect to decreasing the stability of NOTCH3, which may help with the prognosis and therapy of inherited thrombocytopenia.

Tangeretin attenuates lipopolysaccharide-induced acute lung injury through Notch signaling pathway via suppressing Th17 cell response in mice

Tangeretin, a polymethoxylated flavonoid is abundant in citrus fruits, which has been reported to inhibit inflammation by inhibiting NF-κB activation and proinflammatory cytokines. Notch blockage inhibits Th17 cells response that are involved in the development of acute lung injury (ALI). This study investigated the protective effects of tangeretin on LPS-induced ALI in mice. Male C57BL/6 mice were treated with phosphate-buffered saline (PBS), lipopolysaccharide (LPS), LPS and tangeretin, or LPS and N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT, a Notch signaling inhibitor), which were harvested at 48 h after challenged by LPS. CD4⁺ T cells were treated with tangeretin or DAPT and harvested after 72 h. Tangeretin notably attenuated pathological changes and decreased the wet to dry weight ratio of the mouse lungs. The total cell and neutrophil counts, tumor necrosis factor (TNF)-α in bronchoalveolar lavage fluid (BALF), myeloperoxidase activity of lung tissue were markedly reduced by tangeretin. The percentage of CD4+IL-17 + T cells in the lungs and the concentration of interleukin (IL)-17 and IL-22 in BALF were significantly down-regulated by tangeretin. As with the positive control (DAPT), tangeretin inhibited the activity of the Notch signaling pathway accompanied with the down-regulation of acid-related orphan receptor gamma t and IL-23 receptor expression. This study demonstrated that tangeretin protects against LPS-induced ALI by suppressing Th17 response at least partially, through a Notch-dependent mechanism.

Transcriptome analysis of fowl adenovirus serotype 4 infection in chickens

Fowl adenovirus serotype 4 (FAdV-4) is a causative agent of inclusion body hepatitis and hydropericardium–hepatitis syndrome. These diseases cause considerable economic losses in the global poultry industry and are significant stressors for infected chickens. However, the molecular mechanisms of FAdV-4 pathogenesis are poorly understood. In the present study, we identified differentially expressed genes from the livers of FAdV-4-infected chickens using RNA-seq at 7, 14 and 21 days after FAdV-4 infection. We identified 2395 differentially expressed genes at the three time points. These genes were enriched in variety of biological processes and pathways including PPAR and Notch signaling, cytokine–cytokine receptor interactions and Toll-like receptor signaling pathways. The transcriptional data were validated by quantitative real-time PCR. Our results will assist in the understanding of the molecular pathogenesis of FAdV-4 infection and for developing novel antiviral therapies.

Activation of the Notch signaling pathway disturbs the CD4+/CD8+, Th17/Treg balance in rats with experimental autoimmune uveitis

OBJECTIVE AND DESIGN

The present study aimed to investigate the relationship between the disturbed balance of CD4⁺/CD8⁺, Th17/Treg and the activation of the Notch signaling pathway in experimental autoimmune uveitis (EAU).

METHODS

An EAU rat model was induced in Lewis rats, and pathology analysis was performed by hematoxylin and eosin (H&E) staining. CD4⁺, CD8⁺, Th17, and Treg levels in spleen, lymph nodes and eye tissues were determined by flow cytometry. Meanwhile, the expression of Notch1, DLL4, IL-10, and IL-17 was determined by quantitative polymerase chain reaction (Q-PCR) and enzyme-linked immunosorbent assay (ELISA). In addition, the inhibitory effect of N-(N-(3,5-difluorophenacetyl-L-alanyl))-S-phenylglycine t-butyl ester (DAPT) on Th17 differentiation by Notch signaling in vitro was further investigated using T lymphocytes from EAU rats on day 12 post-immunization by flow cytometry.

RESULTS

The pathological results showed that inflammatory cell infiltration occurred in ocular tissues in EAU rats. The CD4⁺/CD8⁺ and Th17/Treg ratios in EAU rats were apparently higher than those in normal control individuals. Q-PCR and ELISA analyses indicated the expression of Notch1, DLL4, IL-10, and IL-17 in EAU rats gradually increased on day 6 after immunization, peaked on day 12, and then gradually decreased. The dynamic trends in Notch1 and DLL4 expression in EAU rats were identical to those of CD4⁺/CD8⁺ and Th17/Treg levels. DAPT can significantly inhibit the activation of Notch signaling, decrease Th17 cell differentiation, and attenuate the level of the Th17 cell lineage, contributing to the balance of the Th17/Treg ratio.

CONCLUSION

The activation of the Notch signaling pathway can regulate Th17 and Treg cell differentiation, disrupt the CD4⁺/CD8⁺ and Th17/Treg balance, and aggravate the severity of EAU; inactivation of the Notch signaling pathway contributes to the CD4⁺/CD8⁺ and Th17/Treg balance in EAU rats. Our findings highlighted that the dynamic change in the CD4⁺/CD8⁺ and Th17/Treg ratio was consistent with the expression trend of Notch signaling in EAU rats, suggesting that Notch signaling may be a potentially important therapeutic target in clinical practice.

The potential therapeutic benefit of resveratrol on Th17/Treg imbalance in immune thrombocytopenic purpura

BACKGROUND

Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by the restrained production of new platelets and the persistent reduction of existing platelets. An imbalance between Th17 and Treg cells is associated with a decrease in platelets. However, few therapeutic strategies aim to modulate this imbalance between Th17 and Treg cells in ITP.

METHODS

ITP patients and healthy controls were enrolled in this study. Quantitative real-time PCR (qRT-PCR) and Western blotting were performed to measure the expression of the aryl hydrocarbon receptor (AhR), cytochrome P450 family 1 member A1 (CYP1A1), RAR-related orphan receptor gamma t (ROR-γt) and forkhead-box P3 (Foxp3). ELISA was employed to measure the secretion of IL-17A, IL-22 and IL-10. Flow cytometry was used to assess the proportion of Th17 and Treg cells. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to measure cell viability.

RESULTS

The proportion of Th17 cells and the secretion of the pro-inflammatory cytokines IL-17A and IL-22 were both elevated, whereas the proportion of Treg cells and the production of the anti-inflammatory cytokine IL-10 were both reduced in ITP patients compared to healthy controls. The ratio of Th17/Treg cells and the expression of IL-17A and IL-22 displayed a positive correlation with the severity of ITP. Low and moderate concentrations of resveratrol did not affect the viability of CD4⁺ T cells from ITP patients but repressed Th17 differentiation and promoted Treg differentiation. Moreover, resveratrol could markedly downregulate the production of IL-17A and IL-22 and upregulate the secretion of IL-10 in CD4⁺ T cells in a time- and concentration-dependent manner. Mechanistic studies revealed that resveratrol exerted its beneficial function mainly through suppressing the AhR pathway, which led to the impaired expression of ROR-γt and reduced secretion of IL-17A and IL-22, as well as enhanced expression of Foxp3 and augmented secretion of IL-10. The induction of AhR by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in CD4⁺ T cells led to a Th17/Treg imbalance and the upregulation of IL-17A and IL-22, an effect that could be reversed by resveratrol treatment.

CONCLUSION

This study revealed that resveratrol reversed the Th17/Treg imbalance by a mechanism involving the suppression of the AhR pathway. Since ITP is characterized by a Th17/Treg imbalance, resveratrol might be beneficial for the treatment of this condition.

Notch signaling pathway regulates CD4+CD25+CD127dim/- regulatory T cells and T helper 17 cells function in gastric cancer patients

Regulatory T cells (Tregs) and T helper 17 (Th17) cells contribute to cancer progression and prognosis. However, regulatory factors associated with Tregs-Th17 balance were not completely understood. We previously demonstrated an immune-modulatory capacity by Notch signaling inactivation to reverse Tregs-Th17 disequilibrium in chronic hepatitis C. Thus, the aim of current study was to assess the role of Notch signaling in modulation Tregs and Th17 cells function in gastric cancer (GC) patients. A total of 51 GC patients and 18 normal controls (NCs) were enrolled. Notch1 and Notch2 mRNA expressions were semiquantified by real-time polymerase chain reaction. Tregs/Th17 percentages, transcriptional factors, and cytokines production were investigated in response to the stimulation of Notch signaling inhibitor DAPT. Both Notch1 and Notch2 mRNA expressions were elevated in GC tissues and peripheral bloods in GC patients. CD4⁺CD25⁺CD127^dim/- Tregs and Th17 cells percentage was also elevated in GC patients compared with in NCs. DAPT treatment did not affect frequency of either circulating Tregs or Th17 cells, however, reduced FoxP3/RORγt mRNA expression and interleukin (IL)-35/IL-17 production in purified CD4⁺ T cells from GC patients. Moreover, blockade of Notch signaling also inhibited the suppressive function of purified CD4⁺CD25⁺CD127^dim/- Tregs from GC patients, which presented as elevation of cellular proliferation and IL-35 secretion. The current data further provided mechanism underlying Tregs-Th17 balance in GC patients. The link between Notch signaling and Th cells might lead to a new therapeutic target for GC patients.

Distinct notch signaling expression patterns between nucleoside and nucleotide analogues treatment for hepatitis B virus infection

Nucleos(t)ide analogues therapies are currently approved for the treatment of chronic hepatitis B virus (HBV) infection, which effectively suppress HBV replication and correlate with the anti-HBV-specific immune response. Notch signaling serves pleiotropic roles in the immune system that also contribute to virus-specific immunity. In this study, we assessed Notch signal-related gene expression after administrating nucleoside or nucleotide analogues to HBV-replicating cells and clinical liver tissues. We found distinct Notch signaling expression patterns under nucleos(t)ide analogues therapies, with high expression for nucleotide analogues (adefovir pivoxil or tenofovir disoproxil fumarate) and low expression for nucleoside analogues (lamivudine or entecavir) in the presence of HBV infection. Furthermore, activation of mammalian target of rapamycin (mTOR)-Akt (Ser473) phosphorylation was also observed after nucleotide analogue treatment. In conclusion, nucleoside and nucleotide analogues displayed different patterns of Notch signaling activity under HBV infection, and the induction of mTORC2-Akt (Ser473) phosphorylation may contribute to nucleotide analogues-mediated Notch signaling activation.

Clinical, endoscopic, and histologic characteristics of lymphocytic esophagitis: a systematic review

OBJECTIVE

Lymphocytic esophagitis (LyE) is a novel, yet poorly described, clinicopathologic entity. The aim of this systematic review was to characterize the demographic, clinical, endoscopic, and histologic features of LyE in observational studies of adult and pediatric patients.

DESIGN

We searched the Embase, MEDLINE, and SCOPUS databases for relevant studies in 2018. Two authors reviewed and extracted data from studies that met the inclusion and exclusion criteria.

RESULTS

We identified 20 studies for analysis of demographic, clinical, and endoscopic features of LyE. The mean age ranged from 9 to 67 years. When pooled, there were 231 (52.7%) patients with LyE that were female. The most common presenting symptom was dysphagia reported in 191 (48.8%) patients. On endoscopy, most patients with LyE tended to have abnormal findings (69.0%), which included erosive esophagitis, multiple esophageal rings, linear furrows, and narrow-caliber esophagus. In the 31 studies used to assess the histologic definition, the cut-off number of intraepithelial lymphocytes (IELs) was reported in 16 (51.6%) studies, peripapillary IEL specification in 18 (58.1%) studies, and presence of spongiosis in 6 (19.4%) studies.

CONCLUSION

We identified a spectrum of demographic, clinical, and endoscopic findings characteristic of patients with LyE. A consensus on the diagnostic criteria of LyE is required.

NOTCH2/NOTCH3/DLL3/MAML1/ADAM17 signaling network is associated with ovarian cancer

Notch signaling is well-known for its role in regulating cell self-renewal and differentiation. Within the cancer research field, it has been identified that dysregulated Notch signaling is involved directly with various types of cancer. Although Notch signaling is generally considered as oncogenic, it sometimes acts as a tumor suppressor, highlighting the complexity of the role of Notch in cancer. A number of studies have associated Notch signaling components with ovarian cancer, but the underlying molecular mechanisms are not well-elucidated. In the present study, the roles of main components of Notch signaling in ovarian cancer were systematically analyzed through large data portals, including Prediction of Clinical Outcomes from Genomic Profiles, Gene Expression across Normal and Tumor tissue, CSIOVDB, Broad Institute Cancer Cell Line Encyclopedia and cBioPortal. Upregulated expression of proteins in the Notch signaling pathway components in ovarian cancer was identified to be generally associated with poor overall and disease-free survival time, and more advanced cancer stages. In addition, Notch components were enriched in ovarian cancer tissues and cell lines. These results led to a proposed neurogenic locus notch homolog protein (NOTCH)2/NOTCH3/Delta-like protein 3/Mastermind-like protein 1/a disintegrin and metalloproteinase domain-containing protein 17 network. Anticancer drugs, developed to target this network, may have high specificity in treating Notch-associated ovarian cancer.

Aberrant expression of microRNA in CD4+ cells contributes to Th17/Treg imbalance in primary immune thrombocytopenia

INTRODUCTION

Imbalance of T helper 17 (Th17) cells and regulatory T (Treg) cells occurs in primary immune thrombocytopenia (ITP), but the mechanism remains unclear. We investigated whether expression of microRNAs (miRNAs) related to helper T or Treg cells regulate the Th17/Treg ratio in CD4⁺ T cells.

MATERIALS AND METHODS

Peripheral blood was obtained from 52 active ITP patients and 56 healthy controls. We detected miRNA expression using RT-PCR with stem-loop primers and U6 as control.Th17 and Treg percentages were analyzed by flow cytometry. CD4⁺ cells were transfected with miRNA (miR-99a, miR-182-5p, miR-183-5p) mimics or inhibitors to investigate their function.

RESULTS

miR-99a expression in CD4⁺ cells in ITP patients was lower than in controls, while expression of miR-182-5p and miR-183-5p were higher in ITP patients. Moreover, Treg percentage correlated positively with miR-99a expression in ITP patients. We found no significant correlation between Th17 percentage and miR-182-5p or miR-183-5p expression. miR-183-5p expression correlated negatively with platelet count, while we found no significant difference between platelet count and miR-99a or miR-182-5p. miR-183-5p expression in CD4⁺ T cells from severe patients was significantly higher than in those from non-severe patients. Furthermore, down-regulating miR-183-5p expression repressed Th17 differentiation, while up-regulating miR-99a increased Tregs detected in CD4⁺ cells from ITP patients. In addition, up-regulated miR-99a repressed mTOR and p-mTOR expression.

CONCLUSIONS

miR-99a, miR-182-5p, and miR-183-5p expression levels in CD4⁺ cells were abnormal in ITP patients. Aberrant expression of miRNAs may contribute to the Th17/Treg imbalance in ITP patients and may represent a novel therapeutic target.

Indirubin modulates CD4+ T-cell homeostasis via PD1/PTEN/AKT signalling pathway in immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disease characterized by an immune mediated decrease in platelet number. Disturbance of CD4⁺ T-cell homeostasis with simultaneous decrease of CD4⁺ CD25⁺ Foxp3⁺ regulatory T cells (Tregs) as well as unrestricted proliferation and activation of peripheral CD4⁺ effector T cells underpin the pathophysiology of ITP. Indirubin is an active ingredient of a traditional Chinese herb called Indigofera tinctoria L. which is clinically used for the treatment of ITP patients. Whether indirubin targets the Tregs/effector T cell-axis to restore platelet number is unknown. In our in vitro studies, Indirubin could significantly enhance the number and function of Tregs and meanwhile dampen the activation of effector T cells in a dose-dependent manner. Indirubin was observed to restore the expression of programmed cell-death 1 (PD1) and phosphatase and tensin homolog (PTEN) on the CD4⁺ T cells of ITP patients, leading to the subsequent attenuation of the AKT/mTOR pathway. Furthermore, these observations were recapitulated in an active murine model of ITP with a prominent platelet response. Thus, our results identified a potentially novel mechanism of the therapeutic action of indirubin in the treatment of ITP through regulating the homeostasis of CD4⁺ T cells in a PD1/PTEN/AKT signalling pathway.

CCR6 defines a subset of activated memory T cells of Th17 potential in immune thrombocytopenia

Current researches have determined the significance of C-C chemokine receptor (CCR)6 expression as either a marker of T helper cells (Th) or an effector and regulator of T cell function. However, the roles of CCR6 in the pathogenesis of immune thrombocytopenia (ITP) are unclear. In this study, we aimed to investigate the phenotype and functional characteristics of circulating CCR6⁺ T cells in blood from chronic ITP patients and healthy controls. We found that the frequency of CCR6⁺ CD4⁺ cells was higher in ITP patients than in healthy controls. Anti-CD3/anti-CD28 stimulation induced rapid expansion of CCR6⁺ CD4⁺ cells in ITP patients. CCR6⁺ CD4⁺ cells had a phenotype of activated cells and predominantly expressed CD45RO. Forkhead box protein P3 (FoxP3) and CD25-positive cells were exclusively detected within the CCR6⁺ CD4⁺ cells. In ITP patients, CCR6⁺ regulatory T cells (T_reg ) were decreased and positively correlated with platelet counts and transforming growth factor (TGF)-β plasma levels. In contrast to CCR6^- counterparts, CCR6⁺ CD4⁺ cells produced higher levels of interleukin (IL)-17A. The frequency of CCR6⁺ Th17 was higher in ITP patients and positively correlated with IL-17A levels in supernatant. Most importantly, CCR6⁺ CD4⁺ cell subpopulations, but not CCR6^- CD4⁺ , were closely correlated to treatment response of ITP patients. These findings suggest that circulating CCR6⁺ CD4⁺ cells in ITP patients have characteristics of activated memory Th17 phenotype and could be used to monitor disease activity and treatment response.

Notch1 Signaling Regulates the Th17/Treg Immune Imbalance in Patients with Psoriasis Vulgaris

Purpose

To evaluate the regulating effect of Notch1 signaling on Th17/Treg immune imbalance in psoriasis vulgaris (PV).

Materials and Methods

Notch1, Hes-1, RORγt, Foxp3, IL-17, and IL-10 mRNA expression, as well as Th17 and Treg cell percentages in peripheral CD4⁺ T cells, were detected by real-time quantitative RT-PCR and flow cytometry, and serum concentrations of IL-17 and IL-10 were detected by ELISA in 36 PV patients and 32 healthy controls. Additionally, CD4⁺ T cells from 12 PV patients were treated with γ-secretase inhibitor DAPT, and the above indexes were measured.

Results

PV patients presented distinct Th17/Treg immune imbalance and highly expressed Notch1 and Hes-1 mRNA levels, which were positively correlated with psoriasis area and severity index (PASI) and the ratios of Th17/Treg and RORγt/Foxp3. DAPT treatment resulted in the obvious downregulation of Th17 cell percentage in cocultured CD4⁺ T cells, RORγt and IL-17 mRNA levels, and IL-17 concentration in cell-free supernatant from cocultured CD4⁺ T cells of PV patients in a dose-dependent manner, while there was no significant influence on Treg cell percentage, Foxp3, and IL-10 expression, therefore leading to the recovery of Th17/Treg immune imbalance.

Conclusion

Notch1 signaling may contribute to the pathogenesis of PV by regulating Th17/Treg immune imbalance.

Circulating level of Th17 cells is associated with sensitivity to glucocorticoids in patients with immune thrombocytopenia

Glucocorticoids are a widely recognized first-line therapy for immune thrombocytopenia (ITP). However, some patients are unresponsive to glucocorticoid therapy for reasons that remain unclear. Accumulating evidence suggests that CD4⁺ T-cell abnormalities play a crucial role in the development of ITP. In the present study, we investigated peripheral blood CD4⁺ T cells, Th17-associated cytokines, and the mRNA expression level of Th17 transcription factor-RORγt-in patients with newly-diagnosed ITP before glucocorticoid therapy. The study involved 27 newly-diagnosed patients. Th17-cell levels in the peripheral blood of newly-diagnosed ITP patients were associated with responsiveness to glucocorticoid therapy. Newly-diagnosed ITP patients who were not sensitive to glucocorticoid treatment were found to have lower levels of Th17 cells. Quantifying Th17 cells may allow physicians to predict prognosis of glucocorticoid treatment and stratify therapy for those with ITP. This strategy may provide a new approach to the treatment of glucocorticoid-insensitive patients.

Neuropathy correlated with imbalanced Foxp3/IL-17 in bone marrow microenvironment of patients with acute myeloid leukemia

Bone marrow (BM) neural tissues are important components of bone marrow microenvironment and play important roles in normal hematopoiesis. Neuropathy of BM can cause immunological alteration in hematopoietic microenvironment. It also can induce the impairment of normal hematopoiesis and promote the development of hematologic diseases. In the present study, we determined the expression levels and clinical significances of nerve-related molecules [nestin, tyrosine hydroxylase (TH), Glial Fibrillary Acidic protein (GFAP) and S100B] and T helper-related molecules (IL-17, Foxp3) in BM of AML patients and controls by immunohistochemical analysis and RT-PCR. Our results showed that the positive rates and expression levels of nestin, TH, GFAP and IL-17 were significantly decreased while Foxp3 and the ratio of Foxp3/IL-17 were statistically elevated in BM of AML patients. We found that there were significantly positive correlations between nestin with TH and IL-17 in BM of AML patients. We also observed significantly negative correlations between nestin with TH and Foxp3/IL-17 ratio. Moreover, the expression of nestin was positively correlated with the overall survival of AML patients. Our study suggests that neuropathy together with imbalanced T helper immunology in bone marrow might play important roles in AML.

Interleukin-35 Modulates the Imbalance Between Regulatory T Cells and T Helper 17 Cells in Enterovirus 71-Induced Hand, Foot, and Mouth Disease

Interleukin (IL)-35 modulates the imbalance between regulatory T cells (Tregs) and T helper (Th) 17 cells, which played vital roles in the pathogenesis of autoimmune and infectious diseases. However, the role of Tregs/Th17 cell imbalance and the regulatory functions of IL-35 have remained largely unknown in enterovirus 71 (EV71)-induced hand, foot, and mouth disease (HFMD). In this study, a total of 47 HFMD patients (30 with mild HFMD and 17 with severe HFMD) and 13 healthy individuals were enrolled. The frequencies of CD4⁺CD25⁺CD127^dim/- Tregs and CD4⁺IL-17⁺ Th17 cells, as well as IL-35 expression levels, were measured. Cellular proliferation and cytokine production was also determined in purified Tregs following recombinant IL-35 stimulation. An imbalance between Tregs and Th17 cells was observed in children with severe HFMD, which manifested as a reduction in the Tregs population and an elevation in the Th17 population. Serum IL-35 concentrations were also decreased in case of severe HFMD, which correlated with the Tregs:Th17 cell ratios. Recombinant IL-35 stimulation increased the proportion of Tregs, but downregulated that of Th17 cells. Treatment with IL-35 enhanced Tregs suppressive function and IL-35 and IL-10 expression, but reduced IL-22 secretion in both healthy individuals and those with severe HFMD. The Tregs:Th17 cell ratio was increased in the convalescent patients, however, a significant reduction in serum IL-35 was not observed. Our findings indicated that EV71 infection shifted the Tregs:Th17 cell ratio through IL-35 by downregulating inhibitory cytokine production and reducing the cell-to-cell contact inhibition of effector T cells. Regulation of IL-35 as it relates to the Tregs/Th17 balance may play a critical role in the pathogenesis of EV71-associated HFMD.

Down-regulation of Notch signaling pathway reverses the Th1/Th2 imbalance in tuberculosis patients

Th1/Th2 imbalance to Th2 is of significance in the peripheral immune responses in Tuberculosis (TB) development. However, the mechanisms for Th1/Th2 imbalance are still not well determined. Notch signaling pathway is involved in the peripheral T cell activation and effector cell differentiation. However, whether it affects Th1/Th2 imbalance in TB patients is still not known. Here, we used γ-secretase inhibitor (DAPT) to treat the peripheral blood mononuclear cells (PBMCs) from healthy people or individuals with latent or active TB infection in vitro, respectively. Then, the Th1/Th2 ratios were determined by flow cytometry, and cytokines of IFN-γ, IL-4, IL-10 in the culture supernatant were measured by CBA method. The Notch signal pathway associated proteins Hes1, GATA3 and T-bet were quantitated by real-time PCR or immunoblotting. Our results showed that DAPT effectively inhibited the protein level of Hes1. In TB patients, the Th2 ratio increased in the PBMCs, alone with the high expression of GATA3 and IL-4, resulting in the high ratios of Th2/Th1 and GATA3/T-bet in TB patients. However, Th2 cells ratio decreased after blocking the Notch signaling pathway by DAPT and the Th2/Th1 ratio in TB patients were DAPT dose-dependent, accompanied by the decrease of IL-4 and GATA3. But, its influence on Th1 ratio and Th1 related T-bet and IFN-γ levels were not significant. In conclusion, our results suggest that blocking Notch signaling by DAPT could inhibit Th2 responses and restore Th1/Th2 imbalance in TB patients.

Effects of PM2.5 exposure on the Notch signaling pathway and immune imbalance in chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) is associated with T lymphocytes subset (Th1/Th2, Th17/Treg) imbalance. Notch signaling pathway plays a key role in the development of the adaptive immunity. The immune disorder induced by fine particulate matter (PM2.5) is related to COPD. The aim of this study was to investigate the mechanism by which PM2.5 influences the Notch signaling pathway leading to worsening immune disorder and accelerating COPD development. A COPD mouse model was established by cigarette smoke exposure. PM2.5 exposure was performed by aerosol inhalation. γ-secretase inhibitor (GSI) was given using intraperitoneal injection. Splenic T lymphocytes were purified using a density gradient centrifugation method. CD4⁺ T lymphocyte subsets (Th1/Th2, Th17/Treg) were detected using flow cytometry. mRNA and proteins of Notch1/2/3/4, Hes1/5, and Hey1 were detected using RT-PCR and Western blot. Serum INF-γ, IL-4, IL-17 and IL-10 concentrations were measured using ELISA. The results showed that in COPD mice Th1% and Th17%, Th1/Th2 and Th17/Treg were increased, and the levels of mRNA and protein in Notch1/2/3/4, Hes1/5, and Hey1 and serum INF-γ and IL-17 concentrations were significantly increased, and Th2%, Treg%, and serum IL-4 and IL-10 concentrations were significantly decreased. COPD Mice have Th1- and Th17-mediated immune disorder, and the Notch signaling pathway is in an overactivated state. PM2.5 promotes the overactivation of the Notch signaling pathway and aggravates the immune disorder of COPD. GSI can partially inhibit the activation of the Notch signaling pathway and alleviate the immune disorder under basal state and the immune disorder of COPD caused by PM2.5. This result suggests that PM2.5 is involved in the immune disorder of mice with COPD by affecting the Notch signaling pathway and that PM2.5 aggravates COPD.

Interleukin-35: a Potential Therapeutic Agent for Autoimmune Diseases

Autoimmune diseases contain a large number of pathologies characterized by various factors that contribute to a breakdown in self-tolerance. Cytokine-mediated immunity plays an essential role in the pathogenesis of varieties of autoimmune diseases. Recent studies reveal that interleukin-35 (IL-35), a newly identified cytokine of IL-12 family, is implicated in the pathogenesis of autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), etc. In this review, we will discuss the biological features of IL-35 and summarize recent advances in the role of IL-35 in the development and pathogenesis of autoimmune diseases; the discoveries gained from these findings might translate into future therapies for these diseases.

[Quantity of Treg cells and Th17 cells in spleen of primary immune thrombocytopenic purpura patients]

Objective: To observe the quantity of Treg cells and Th17 cells in spleen of adult primary immune thrombocytopenic purpura (ITP) patients. Methods: 43 ITP cases with splenectomy treatment were enrolled from December 2008 to June 2016 at Union Hospital of Fujian Medical University, including 20 males and 23 females with a median age of 36 (18-76) years. The controls were thirty patients who underwent splenectomy because of pancreatic diseases or splenic impairment, including 21 males and 9 females with a median age of 47 (21-69) years. The quantity and ratio of Treg cells and Th17 cells were examined by immunohistochemistry between ITP patients and controls. Results: ①The quantity of Treg cells in ITP were less than controls[ (11.3±4.7) /mm(2) vs (59.0±15.0) /mm(2), t=-22.894, P<0.001], but Th17 cells were more than controls[ (235.2±69.4) /mm(2) vs (181.1±23.7) /mm(2), t=13.768, P<0.001]. So the ratio of Treg/Th17 in ITP was lower than controls (0.048±0.027 vs 0.328±0.086, t=19.522, P<0.001) . ② The quantity of Treg cells in cases without response after splenectomy were less than cases with response[ (9.5±5.0) /mm(2) vs (11.6±4.7) /mm(2), t=2.723, P=0.010], and there is no statistical differences between the two groups about the quantity of Th17 cells and the ratio of Treg/Th17 cells[ (232.3±80.8) /mm(2) vs (239.6±66.9) /mm(2), t=1.108, P=0.277; 0.040±0.024 vs 0.053±0.027, t=0.540, P=0.592]. Conclusions: There is a significant difference about the quantity of Treg cells and Th17 cells in spleen between ITP patients and healthy controls, and they are relevant to the response after splenectomy.

Notch Signaling Modulates the Balance of Regulatory T Cells and T Helper 17 Cells in Patients with Chronic Hepatitis C

The imbalance of regulatory T cells (Tregs) and T helper 17 (Th17) cells contributes to the persistent hepatitis C virus (HCV) infection. However, modulatory factors associated with Tregs-Th17 balance were not fully elucidated. A recent study demonstrated an immunoregulatory strategy by inactivation of Notch signaling to reverse the disequilibrium of Tregs-Th17 cells in immune thrombocytopenia. Thus, the aim of this study was to assess the effect of Notch signaling in regulating the functions of Tregs and Th17 cells in chronic hepatitis C. A total of 46 patients with chronic hepatitis C and 17 normal controls (NCs) were enrolled. mRNA expressions of Notch1 and Notch2 were semiquantified by real-time reserve polymerase chain reaction. Percentages of Tregs-Th17, levels of key transcriptional factors, and cytokine productions were measured in response to treatment by DAPT, a γ-secretase inhibitor to suppress Notch signaling. We found that Notch1 and Notch2 mRNAs were significantly elevated in peripheral blood mononuclear cells from chronic hepatitis C patients compared with those from NCs. DAPT treatment reduced Th17 response by downregulation of RORγt expression and interleukin (IL)-17/IL-22 secretion. Tregs proportion, FoxP3 expression, and IL-10 production did not change significantly with DAPT treatment in chronic hepatitis C; however, blockage of Notch signaling inhibited the suppressive function of Tregs. Moreover, effective anti-HCV therapy not only reduced Notch1 and Notch2 expression but also decreased Tregs and Th17 proportions. The current data provided a novel mechanism underlying the modulation of Treg-Th17 balance. The link between Notch signaling and Th cells might lead to a new intervention for breaking immunotolerance of chronic HCV infection.

The Functional Stability of FOXP3 and RORγt in Treg and Th17 and Their Therapeutic Applications

The balance of CD4⁺CD25⁺FOXP3⁺ regulatory T cells (Tregs) and effector T cells plays a key role in maintaining immune homeostasis, while the imbalance of them is related to many inflammatory diseases in both human and mice. Here we discuss about the plasticity of Tregs and Th17 cells, and the related human diseases resulted from the imbalance of them. Further, we will focus on the mechanisms regulating the plasticity between Tregs and Th17 cells and the potential therapeutic strategies by targeting regulators of the expression and activity of FOXP3 and RORγt or regulators of Treg/Th17 balance in autoimmune diseases, allergy, infection, and cancer.

Laboratory Investigation web focus on China

The vast growth of China's publishing output is a reflection of the increasing strength of Chinese science. The editors of Laboratory Investigation (LI) present a collection of papers that showcases research by authors from institutions across China, highlighting the significant contributions of Chinese scientists to the journal.

Notch signalling suppresses regulatory T-cell function in murine experimental autoimmune uveitis

Autoimmune uveitis is an intraocular inflammatory disorder in developed countries. Understanding the mechanisms underlying the development and modulation of immune reaction in uveitic eyes is critical for designing therapeutic interventions. Here we investigated the role of Notch signalling in regulatory T-cell (Treg cell) function during experimental autoimmune uveitis (EAU). Using the Foxp3-GFP reporter mouse strain, the significance of Notch signalling for the function of infiltrating Treg cells was characterized in an EAU model. We found that infiltrating Treg cells substantially expressed Notch-1, Notch-2, JAG1 and DLL1 in uveitic eyes. Activation of Notch signalling, represented by expression of HES1 and HES5, was enhanced in infiltrating Treg cells. Treatment with JAG1 and DLL1 down-regulated Foxp3 expression and immunosuppressive activity of isolated infiltrating Treg cells in vitro, whereas neutralizing antibodies against JAG1 and DLL1 diminished Notch ligand-mediated negative effects on Treg cells. To investigate the significance of Notch signalling for Treg cell function in vivo, lentivirus-derived Notch short hairpin RNAs were transduced into in vitro expanded Treg cells before adoptive transfer of Treg cells into EAU mice. Transfer of Notch-1-deficient Treg cells remarkably reduced pro-inflammatory cytokine production and inflammatory cell infiltration in uveitic eyes. Taken together, Notch signalling negatively modulates the immunosuppressive function of infiltrating Treg cells in mouse EAU.

The osteoimmunology of alveolar bone loss

The mineralized structure of bone undergoes constant remodeling by the balanced actions of bone-producing osteoblasts and bone-resorbing osteoclasts (OCLs). Physiologic bone remodeling occurs in response to the body's need to respond to changes in electrolyte levels, or mechanical forces on bone. There are many pathological conditions, however, that cause an imbalance between bone production and resorption due to excessive OCL action that results in net bone loss. Situations involving chronic or acute inflammation are often associated with net bone loss, and research into understanding the mechanisms regulating this bone loss has led to the development of the field of osteoimmunology. It is now evident that the skeletal and immune systems are functionally linked and share common cells and signaling molecules. This review discusses the signaling system of immune cells and cytokines regulating aberrant OCL differentiation and activity. The role of these cells and cytokines in the bone loss occurring in periodontal disease (PD) (chronic inflammation) and orthodontic tooth movement (OTM) (acute inflammation) is then described. The review finishes with an exploration of the emerging role of Notch signaling in the development of the immune cells and OCLs that are involved in osteoimmunological bone loss and the research into Notch signaling in OTM and PD.

Correlation between microRNA-21 and expression of Th17 and Treg cells in microenvironment of rats with hepatocellular carcinoma

OBJECTIVE

To study the correlation between miR-21 and Treg/Th17 ratio in the microenvironment of rats with hepatocellular carcinoma.

METHODS

Diethylnitrosamine was used to build the hepatocellular carcinoma model of rats; the content of Treg cells and Th17 cells and the expression of miR-21 in the peripheral blood of rats with hepatocellular carcinoma were detected. The statistical analysis was performed on the correlation between miR-21 expression and Treg/Th17 ratio.

RESULTS

Hepatocellular carcinoma model of rats was successfully constructed. The proportion of Th17 cells among all CD4(+)T cells in the peripheral blood of rats with hepatocellular carcinoma was 5.319%, which was higher than the control group; while the proportion of Treg cells was 9.472%, which was higher than the control group. Treg/Th17 ratio in the model group was 1.781, compared with 1.478 in the control group. The expression of miR-21 was increased in the peripheral blood of rats with hepatocellular carcinoma and it showed a positive correlation with the ratio of Treg/Th17.

CONCLUSIONS

There is a positive correlation between the expression level of miR-21 and the ratio of Treg/Th17.

Biomarkers for immune thrombocytopenia

Immune thrombocytopenia is an autoimmune disease with abnormal biomarkers. Immune thrombocytopenia pathogenesis is a complicated process in which the patient’s immune system is activated by platelet autoantigens resulting in immune mediated platelet destruction or suppression of platelet production. The autoantibodies produced by autoreactive B cells against self antigens are considered to play a crucial role. In addition, biomarkers such as transforming growth factor-beta1,Toll-like receptors,T helper 1 andT helper 2 cytokine bias, Notch signaling and abnormal biomarker in megakaryocyte maturation are involved in the pathogenesis of this disease. With the genomewide association study on immune thrombocytopenia, more biomarkers will be founded in the future. They may provides a theoretical basis for the mechanism and treatment of immune thrombocytopenia.