Notch Signaling Regulates Circulating T Helper 22 Cells in Patients with Chronic Hepatitis C

Fibrosis and Hepatocarcinogenesis: Role of Gene-Environment Interactions in Liver Disease Progression

The liver is a complex organ that performs vital functions in the body. Despite its extraordinary regenerative capacity compared to other organs, exposure to chemical, infectious, metabolic and immunologic insults and toxins renders the liver vulnerable to inflammation, degeneration and fibrosis. Abnormal wound healing response mediated by aberrant signaling pathways causes chronic activation of hepatic stellate cells (HSCs) and excessive accumulation of extracellular matrix (ECM), leading to hepatic fibrosis and cirrhosis. Fibrosis plays a key role in liver carcinogenesis. Once thought to be irreversible, recent clinical studies show that hepatic fibrosis can be reversed, even in the advanced stage. Experimental evidence shows that removal of the insult or injury can inactivate HSCs and reduce the inflammatory response, eventually leading to activation of fibrolysis and degradation of ECM. Thus, it is critical to understand the role of gene-environment interactions in the context of liver fibrosis progression and regression in order to identify specific therapeutic targets for optimized treatment to induce fibrosis regression, prevent HCC development and, ultimately, improve the clinical outcome.

The metabolomics analysis of cecal contents elucidates significant metabolites involved in the therapeutic effects of total flavonoids derived from Sonchus arvensis L. in male C57BL/6 mice with ulcerative colitis

Ulcerative colitis (UC), an inflammatory disease affecting the colon and rectal mucosa, is characterized by chronic and heterogeneous behavior of unknown origin. The primary cause of UC is chronic inflammation, which is closely linked to the development of colorectal cancer. Sonchus arvensis L. (SAL), a plant consumed worldwide for its nutritional and medicinal properties, holds significance in this context. In this study, we employed the total flavone in SAL as a treatment for male C57BL/6 mice with UC. The cecal contents metabolic profile of C57BL/6 mice in different groups, including UC (group ML; n = 5), UC treated with aspirin (group AN; n = 5), UC treated with the total flavone in SAL (group FE; n = 5), and healthy male C57BL/6 mice (group CL; n = 5), was examined using UHPLC-Triple-TOF-MS. Through the identification of variations in key metabolites associated with UC and the exploration of their underlying biological mechanisms, our understanding of the pathological processes underlying this condition has been enhanced. This study identified a total of seventy-three metabolites that have a significant impact on UC. Notably, the composition of total flavone in SAL, a medication used for UC treatment, differs from that of aspirin due to the presence of four distinct metabolites (13,14-Dihydro-15-keto-PGE2, Prostaglandin I2 (PGI2), (20R,22R)-20,22-dihydroxycholesterol, and PS (18:1(9Z)/0:0)). These metabolites possess unique characteristics that set them apart. Moreover, the study identified a total of eleven pathways that were significantly enriched in mice with UC, including Aminoacyl-tRNA biosynthesis, Valine, leucine and isoleucine biosynthesis, Linoleic acid metabolism, PPAR signaling pathway, mTOR signaling pathway, Valine, leucine and isoleucine degradation, Lysine degradation, VEGF signaling pathway, Melanogenesis, Endocrine and other factor-regulated calcium reabsorption, and Cocaine addiction. These findings contribute to a better understanding of the metabolic variations in UC following total flavonoids of SAL therapy and provide valuable insights for the treatment of UC.Keywords: Ulcerative colitis; Total flavonoids of Sonchus arvensis L.; Key metabolites; Metabonomics; Cecal contents of male C57BL/6 mice.

IL-22-producing CD3 + CD8- T cells increase in immune clearance stage of chronic HBV infection and correlate with the response of Peg-interferon treatment

Interleukin (IL)-22 regulates host defense. This study investigated the predominant IL-22-producing cell subsets under HBV associated immune stages. We found circulating IL-22-producing CD3 + CD8- T cells were significantly increased in immune active (IA) stage than those in immunotolerant stage, inactive carrier and healthy controls (HCs). The plasma IL-22 level was higher in IA and HBeAg-negative CHB compared to HCs. Importantly, CD3 + CD8- T cells were identified as the predominant source of plasma IL-22 production. Up-regulated IL-22-producing CD3 + CD8- T cells obviously correlated with the grade of intrahepatic inflammation. The proportions of IL-22-producing CD3 + CD8- T cells were significantly down-regulated after 48 weeks of Peg-interferon treatment, and the differences were of great significance in patients with normalize ALT levels at 48 weeks, rather than those with elevated ALT levels. In conclusion, IL-22 might play a proinflammatory function in. chronic HBV infected patients with active inflammation and Peg-interferon treatment could attenuate the degree of liver inflammation through down-regulating IL-22-producing CD3 + CD8- T cells.

Regulation of Notch Signaling Pathway to Innate Lymphoid Cells in Patients with Acute Myocardial Infarction

The Notch signaling pathway is an important regulator in fate decisions and immune responses of innate lymphoid cells (ILCs). However, the function of Notch signaling in ILCs in acute coronary syndrome is still not fully elucidated. Thirty-one unstable angina pectoris (UAP) patients, 21 acute myocardial infarction (AMI) patients, and 20 controls were included in this study. Peripheral blood mononuclear cells (PBMCs) were isolated. The mRNA expression levels of Notch receptors and ligands were measured by real-time PCR, while ILC subsets were measured by flow cytometry. Lin^- cells were purified and stimulated with γ-secretase inhibitor (GSI). ILC subsets, transcription factors, and secreted cytokines were assessed. Notch receptor and ligand mRNA levels were elevated in PBMCs and peripheral lin^- cells from AMI patients. There was no significant difference in total lin^-CD45⁺CD161⁺CD127⁺ ILC frequency among three groups. The CRTH2^-CD117^- ILC1 subset was down-regulated, while the CRTH2⁺ ILC2 subset was up-regulated in AMI patients. The CRTH2^-CD117⁺ ILC3 subpopulation was comparable among the three groups. ILC1% was negatively correlated with Notch1 and Notch2 in AMI patients. Inhibition of Notch signaling pathway by GSI induced elevations in ILC1 frequency, T-bet mRNA expression, and interferon-γ secretion and reduced ILC2 frequency, GATA3 mRNA levels, and interleukin-5/interleukin-13 production by lin^- cells from AMI patients. The current data indicated that activation of Notch signaling pathway might contribute to ILC1-to-ILC2 shift in peripheral blood in AMI patients.

Current Knowledge of Th22 Cell and IL-22 Functions in Infectious Diseases

T helper 22 (Th22) cells, a newly defined CD4+ T-cell lineage, are characterized by their distinct cytokine profile, which primarily consists of IL-13, IL-22 and TNF-α. Th22 cells express a wide spectrum of chemokine receptors, such as CCR4, CCR6 and CCR10. The main effector molecule secreted by Th22 cells is IL-22, a member of the IL-10 family, which acts by binding to IL-22R and triggering a complex downstream signaling system. Th22 cells and IL-22 have been found to play variable roles in human immunity. In preventing the progression of infections such as HIV and influenza, Th22/IL-22 exhibited protective anti-inflammatory characteristics, and their deleterious proinflammatory activities have been demonstrated to exacerbate other illnesses, including hepatitis B and Helicobacter pylori infection. Herein, we review the current understanding of Th22 cells, including their definition, differentiation and mechanisms, and the effect of Th22/IL-22 on human infectious diseases. According to studies on Th22 cells, Th22/IL-22 may be a promising therapeutic target and an effective treatment strategy for various infections.

Role of Th22 Cells in Human Viral Diseases

Naive CD4⁺ T cells can differentiate into different cell subsets after receiving antigen stimulation, which secrete corresponding characteristic cytokines and thereby exert biological effects in various diseases. Th22 cells, a novel subset of CD4⁺ T cells, are different from Th1, Th2, Th17, and Treg cell subsets, which have been discovered in recent years. They can express CCR4, CCR6, and CCR10 molecules and secrete IL-22, IL-13, and TNF-α. They are not able to secrete IL-17, IL-4, and interferon-γ (IFN-γ). IL-22 is considered as a major effector molecule of Th22 cells whose functions and mechanisms of regulating cell differentiation have been constantly improved. In this review, we provide an overview of the origin, differentiation of Th22 cells. Moreover, we also describe the interrelationships between Th22 cells and Th17, Th1, and Th2 cells. Additionally, the role of Th22 cells were discussed in human diseases with virus infection, which will provide novel insight for the prevention and treatment of viral infection in human.

When Viruses Cross Developmental Pathways

Aberrant regulation of developmental pathways plays a key role in tumorigenesis. Tumor cells differ from normal cells in their sustained proliferation, replicative immortality, resistance to cell death and growth inhibition, angiogenesis, and metastatic behavior. Often they acquire these features as a consequence of dysregulated Hedgehog, Notch, or WNT signaling pathways. Human tumor viruses affect the cancer cell hallmarks by encoding oncogenic proteins, and/or by modifying the microenvironment, as well as by conveying genomic instability to accelerate cancer development. In addition, viral immune evasion mechanisms may compromise developmental pathways to accelerate tumor growth. Viruses achieve this by influencing both coding and non-coding gene regulatory pathways. Elucidating how oncogenic viruses intersect with and modulate developmental pathways is crucial to understanding viral tumorigenesis. Many currently available antiviral therapies target viral lytic cycle replication but with low efficacy and severe side effects. A greater understanding of the cross-signaling between oncogenic viruses and developmental pathways will improve the efficacy of next-generation inhibitors and pave the way to more targeted antiviral therapies.

The Notch Pathway: A Link Between COVID-19 Pathophysiology and Its Cardiovascular Complications

COVID-19 is associated with a large number of cardiovascular sequelae, including dysrhythmias, myocardial injury, myocarditis and thrombosis. The Notch pathway is one likely culprit leading to these complications due to its direct role in viral entry, inflammation and coagulation processes, all shown to be key parts of COVID-19 pathogenesis. This review highlights links between the pathophysiology of SARS-CoV2 and the Notch signaling pathway that serve as primary drivers of the cardiovascular complications seen in COVID-19 patients.

Notch Signaling Regulation in HCC: From Hepatitis Virus to Non-Coding RNAs

The Notch family includes evolutionary conserved genes that encode for single-pass transmembrane receptors involved in stem cell maintenance, development and cell fate determination of many cell lineages. Upon activation by different ligands, and depending on the cell type, Notch signaling plays pleomorphic roles in hepatocellular carcinoma (HCC) affecting neoplastic growth, invasion capability and stem like properties. A specific knowledge of the deregulated expression of each Notch receptor and ligand, coupled with resultant phenotypic changes, is still lacking in HCC. Therefore, while interfering with Notch signaling might represent a promising therapeutic approach, the complexity of Notch/ligands interactions and the variable consequences of their modulations raises concerns when performed in undefined molecular background. The gamma-secretase inhibitors (GSIs), representing the most utilized approach for Notch inhibition in clinical trials, are characterized by important adverse effects due to the non-specific nature of GSIs themselves and to the lack of molecular criteria guiding patient selection. In this review, we briefly summarize the mechanisms involved in Notch pathway activation in HCC supporting the development of alternatives to the γ-secretase pan-inhibitor for HCC therapy.

The NOTCH-HES-1 axis is involved in promoting Th22 cell differentiation

BACKGROUND

NOTCH signaling has been shown to play a role in the production of interleukin-22 (IL-22) by CD4+ T cells. Multiple T-helper (Th) cell populations secrete IL-22. Th22 (CD4+IL22+IFNγ-IL17A-) cells are a subgroup of CD4+ effector T cells that primarily generate IL-22. The regulatory mechanisms of the NOTCH signaling pathway involved in differentiation of the Th22 cell subset have not been completely elucidated. This study aimed to further explore the involvement of NOTCH signaling in Th22 differentiation.

METHODS

In vitro combination of IL-6, IL-23, and tumor necrosis factor-α (TNF-α) treatment with naïve CD4+ T cells established the Th22 cell induced model. NOTCH signaling was activated by jagged-1 and inhibited by (2S)-N-[(3,5-difluorophenyl) acetyl]-L-alanyl-2-phenyl]glycine 1,1-dimethylethyl ester (DAPT). HES-1 siRNA and HES-1 vector were employed to knock down and induce overexpression of HES-1 to investigate the effect of NOTCH signaling on the differentiation of CD4+T cells into Th22 cells.

RESULTS

We observed that the proportion of Th22 cells, along with Hes-1, Ahr, and Il-22 mRNA and protein expression, was increased by both jagged-1 and overexpression of HES-1. On the other hand, after the combined cytokine treatment of cells, and exposure to jagged-1 and DAPT or HES-1 siRNA, there was a decrease in the Th22 cell proportion, mRNA and protein expression of HES-1, AHR, and IL-22.

CONCLUSIONS

Our study demonstrates that HES-1 enhancement in AHR and IL-22 up-regulation of NOTCH signaling can promote the skewing of naïve CD4+T cells toward Th22 cells. Also, the results of our study show that HES-1 is a crucial factor in Th22 cell differentiation.

The expression of Th9 and Th22 cells in rats with cerebral palsy after hUC-MSC transplantation

BACKGROUND

This study aimed to investigate the expression of Th9 and Th22 cells in rats with cerebral palsy (CP) after human umbilical cord-derived mesenchymal stem cell (hUC-MSC) transplantation.

METHODS

First, hUC-MSCs were isolated from fresh umbilical cords and identified. Rats were divided into the normal group, CP group, and hUC-MSC transplantation group. The Morris water maze and balance beam tests were performed to evaluate the neurobehavioral ability of the rats. The levels of TNF-α, IL-6, IL-9, and IL-22 in rat brain tissues were detected by ELISA. Th9 and Th22 proportions in brain tissues were detected by flow cytometric analysis. The mRNA levels of IL-9, IL-22, PU.1, and AHR in brain tissues were determined by qRT-PCR.

RESULTS

hUC-MSC transplantation enhanced the neurobehavioral ability of CP rats. Furthermore, Th9 and Th22 proportions were decreased in brain tissues from CP rats after hUC-MSC transplantation. The levels of proinflammatory cytokines (TNF-α and IL-6), Th9-related IL-9 and PU.1, and Th22-related IL-22 and AHR were markedly higher in brain tissues from CP rats than in brain tissues from control rats, but their levels were significantly decreased after hUC-MSC transplantation.

CONCLUSION

Our data indicate that Th9 and Th22 proportions are decreased in CP rats after hUC-MSC transplantation.

Notch signaling pathway regulates T cell dysfunction in septic patients

Sepsis disrupts innate and adaptive immune response, and immune disorders may also impact clinical course of sepsis. Notch signaling pathway plays a vital role in T cell modulation and differentiation. The aim of current study was to investigate the immunoregulatory function of Notch signaling pathway to T cells in patients with sepsis and septic shock. Twenty-seven sepsis patients, twenty-five septic shock patients, and twenty-one normal controls (NCs) were enrolled. Notch receptors mRNA levels were semi-quantified by real-time PCR. The absolute numbers of CD3⁺, CD4⁺, and CD8⁺ T cells were measured by flow cytometry. Key transcriptional factors of CD4⁺ T cells, cytotoxic molecules in CD8⁺ T cells, and cytotoxicity of CD8⁺ T cells were investigated. The regulatory activities of Notch signaling inhibition by γ-secretase inhibitor (GSI) on purified CD4⁺ and CD8⁺ T cells from sepsis and septic shock patients were also assessed. Notch1 mRNA relative level was significantly elevated in sepsis and septic shock patients when compared with NCs. CD4⁺ and CD8⁺ T cells were dysfunctional in sepsis and septic shock, which presented as decreased cell accounts, down-regulation of Th1/Th17 transcriptional factors and cytotoxic molecules (perforin, granzyme B, and FasL), and reduced cytotoxicity of CD8⁺ T cells. Notch signaling inhibition by GSI increased Th1 and Th17 differentiation of CD4⁺ T cells. Moreover, GSI stimulation not only promoted perforin, granzyme B, and FasL mRNA expression in CD8⁺ T cells, but also elevated CD8⁺ T cell-induced target cell death and IFN-γ/TNF-α production in sepsis and septic shock. The current data suggest that Notch signaling pathway contributes to T cell dysfunction and limited immune response in sepsis.

Notch signaling suppresses CD14+ monocytes cells activity in patients with chronic hepatitis C

Hepatitis C virus (HCV) infection always leads to chronic hepatitis via dysregulation of host immunity. Notch signaling also modulates the response of monocytes/macrophages. Thus, we aimed to investigate the regulatory role of Notch signaling to CD14⁺ monocytes. Forty patients with chronic hepatitis C and twenty normal controls (NC) were enrolled. CD14⁺ monocytes and CD4⁺ T cells were purified from peripheral bloods. Notch receptors' mRNA expression in CD14⁺ monocytes was semi-quantified by real-time PCR. Cytokine production by CD14⁺ monocytes in response to γ-secretase inhibitor (GSI) was investigated by ELISA. GSI-induced CD14⁺ monocytes activity to HCV clearance in Huh7.5 cells and to CD4⁺ T cell differentiation was also assessed in direct and indirect contact co-culture system. Notch1 mRNA relative level was approximately 10-fold elevated in CD14⁺ monocytes from chronic hepatitis C patients when compared with NC. GSI stimulation resulted in enhanced cytokines production by CD14⁺ monocytes from chronic hepatitis C patients. GSI-stimulated CD14⁺ monocytes from chronic hepatitis C patients induced suppression of HCV RNA replication in both direct and indirect contact co-culture system of CD14⁺ monocytes and HCVcc-infected Huh7.5 cells, and this process was accompanied by elevation of interferon-γ production but not increased target cell death. Moreover, GSI stimulation also enhanced CD14⁺ monocytes-induced Th1 and Th17 cells activation, and this process required direct cell-to-cell contact. Effective antiviral therapy down-regulated Notch1 mRNA expression and promoted cytokine production by CD14⁺ monocytes from chronic hepatitis C. Current data revealed an important immunoregulatory property of Notch signaling to CD14⁺ monocytes in chronic HCV infection.

Transcription Factor MafB Suppresses Type I Interferon Production by CD14+ Monocytes in Patients With Chronic Hepatitis C

Transcription factor MafB regulates differentiation and activity of monocytes/macrophage and is associated with the development of atherosclerosis and cancers. However, the role of MafB in modulation of CD14⁺ monocytes in chronic viral hepatitis was not fully elucidated. Thus, the aim of current study was to investigate the immunoregulatory function of MafB to type I interferon (IFN) secretion by CD14⁺ monocytes and its contribution to pathogenesis of chronic hepatitis C virus (HCV) infection. A total of 29 chronic hepatitis C patients and 21 healthy individuals were enrolled. Serum IFN-α1 and IFN-β was measured by ELISA, while MafB mRNA and protein expression were assessed by real-time PCR and Western blot. MafB siRNA or MafB expression plasmid was transfected into purified CD14⁺ monocytes to suppress or increase MafB expression. The function of MafB siRNA transfected CD14⁺ monocytes to HCV in cell culture (HCVcc)-infected Huh7.5 cells or CD4⁺ T cells was also investigated in direct and indirect contact co-culture system. Serum IFN-α1 and IFN-β was robustly reduced in chronic hepatitis C patients. By contrast, MafB was notably elevated in chronic hepatitis C patients and negatively correlated with serum IFN-α1. Overexpression of MafB reduced the IFN-α1 production by CD14⁺ monocytes from healthy individuals. However, MafB inhibition elevated IFN-α1 secretion by CD14⁺ monocytes and interferon regulatory factor 3 phosphorylation in chronic hepatitis C. MafB inhibition also promoted CD14⁺ monocytes-induced viral clearance in HCVcc-infected Huh7.5 cells by up-regulation of IFN-α1 and IFN-β without increasingly destroying hepatocytes, however, did not affect CD14⁺ monocytes-induced CD4⁺ T cells differentiation in chronic hepatitis C patients. The current data revealed that overexpression of MafB in chronic hepatitis C patients might suppress type I IFN production by CD14⁺ monocytes, leading to the viral persistence. MafB might be a potential therapeutic target for treatment of chronic hepatitis C.

Elevated Notch1 enhances interleukin-22 production by CD4+ T cells via aryl hydrocarbon receptor in patients with lung adenocarcinoma

Notch signaling induced interleukin (IL)-22 secretion by CD4+ T cells via retinoid-related orphan nuclear receptor γt (RORγt) or aryl hydrocarbon receptor (AhR). Previous studies have demonstrated that Notch-AhR-IL-22 axis took part in the pathogenesis of chronic viral infection, however, its role in cancer has not been fully elucidated. Thus, the aim of current study was to investigate the involvement of Notch-AhR-IL-22 axis in the pathogenesis of lung adenocarcinoma. A total of 37 late-stage lung adenocarcinoma patients and 17 healthy individuals were enrolled. CD4+ T cells were purified from peripheral bloods and bronchoalveolar lavage fluids (BALF), and were stimulated with γ-secretase inhibitor (GSI). mRNA corresponding to Notch receptors and transcriptional factors were measured by real-time PCR. IL-22 concentration was investigated by ELISA. The bioactivity (including cellular proliferation, cell cycle, apoptosis, and invasion) of lung adenocarcinoma cell line A549 was also assessed in response to recombinant IL-22 stimulation in vitro. Notch1 mRNA expression was significantly elevated in CD4+ T cells purified from peripheral bloods and tumor site BALF in lung adenocarcinoma patients. IL-22 expression and RORγt/AhR mRNA in BALF was also remarkably increased in tumor site. Inhibition of Notch signaling by GSI did not affect cellular proliferation, but reduced IL-22 production in CD4+ T cells from BALF, along with down-regulation of AhR, but not RORγt. Moreover, IL-22 stimulation promoted A549 cells invasion. The current data indicated that elevated Notch1 induced higher IL-22 secretion by CD4+ T cells in lung adenocarcinoma patients, and Notch-AhR-IL-22 axis took part in the pathogenesis of lung adenocarcinoma.