PM2.5 and water-soluble components induce airway fibrosis through TGF-ß1/Smad3 signaling pathway in asthmatic rats.

Epidemiological studies have suggested that fine particulate matter (PM2.5) and asthma have been independently associated with pulmonary fibrosis but rarely studied together. Furthermore, it is unknown whether airway fibrosis in asthma is more attributable to water-soluble ions of PM2.5. Our current study was to explore the potential mechanism of PM2.5 and water-soluble components on airway fibrosis in ovalbumin (OVA)-sensitized asthmatic rats. Rats were intratracheally instilled with PM2.5 and water-soluble components every 3 days for 4 times or 8 times. Histopathological examination demonstrated that lung inflammatory and airway fibrosis were induced after PM2.5 and water-soluble components exposure. Meanwhile, PM2.5, in particular water-soluble extracts, increased expression of collagen 1 (COL-1), connective tissue growth factor (CTGF), interleukin-6 (IL-6), transforming growth factor-ß1 (TGF-ß1), Smad family member 3 (Smad3), and p-Smad3, whereas decreased secretion of heme oxygenase-1 (HO-1). However, pretreating asthmatic rats with SB432542, the inhibitor of TGF-ß1, and SIS3 HCl, the antagonist of Smad3, both reversed the activation of airway fibrosis induced by water-soluble extracts. Therefore, TGF-ß1/Smad3 signaling pathway may be responsible for the pathological process of airway fibrosis in asthmatic rats following PM2.5 and water-soluble components exposure.

Modulating oxidative stress counteracts specific antigen-induced regulatory T-cell apoptosis in mice.

Treg are known to have a central role in orchestrating immune responses, but less is known about the destiny of Treg after being activated by specific Ags. This study aimed to investigate the role of superoxide dismutase, an active molecule in the regulation of oxidative stress in the body, in the prevention of Treg apoptosis induced by specific Ags. Ag-specific Tregs were isolated from the DO11.10 mouse intestine. A food allergy mouse model was developed with ovalbumin as the specific Ag and here, we observed that exposure to specific Ag induced Treg apoptosis through converting the precursor of TGF-ß to its mature form inside the Tregs. Oxidative stress was induced in Tregs upon exposure to specific Ags, in which Smad3 bound the latency-associated peptide to induce its degradation, converting the TGF-ß precursor to its mature form, TGF-ß. Suppressing oxidative stress in Tregs alleviated the specific Ag-induced Treg apoptosis in in vitro experiments and suppressed experimental food allergy by preventing the specific Ag-induced Treg apoptosis in the intestine. In conclusion, exposure to specific Ags induces Treg apoptosis and it can be prevented by upregulating superoxide dismutase or suppressing reactive oxidative species in Tregs.

Tumor-associated macrophages promote pancreatic ductal adenocarcinoma progression by inducing epithelial-to-mesenchymal transition.

In this study, we investigated the role of tumor-associated macrophages (TAMs) in the progression of pancreatic ductal adenocarcinoma (PDAC). PDAC patients with higher levels of CD68+ TAMs exhibited shorter overall survival. In Transwell assays, PDAC cells incubated with TAMs or conditioned media from TAM cells (TAM-CM) showed higher migration and invasion rates than controls. PET/CT scan analysis of orthotopic PDAC model mice revealed greater primary tumor growth and liver metastasis in the TAM-CM treatment group than the controls. H&E staining of liver tissues showed significantly higher numbers of metastatic nodules in the TAM-CM treatment group. Heat inactivation of TAM-CM significantly reduced Transwell migration by PDAC cells, suggesting the involvement of one or more secreted proteins in PDAC progression. Transcriptome sequencing analysis of PDAC cells treated with TAM-CM revealed significant enrichment of transforming growth factor-ß (TGF-ß) signaling pathway genes. Western blot and qRT-PCR analysis showed that TAM-CM enhanced PDAC migration cells by inducing epithelial-to-mesenchymal transition through the TGF-ß-Smad2/3/4-Snail signaling axis. The pro-tumorigenic effects of TAMs or TAM-CM were abolished by TGF-ß signaling pathway inhibitors and neutralizing TGF-ß antibody. These results demonstrate that TAMs promote PDAC progression through the TGF-ß signaling pathway.

Cysteinyl leukotriene D4 (LTD4) promotes airway epithelial cell inflammation and remodelling.

OBJECTIVE: Cysteinyl leukotrienes (CysLTs), a group of inflammatory lipid mediators, are found elevated in obese-asthmatic patients. Leukotriene D4 (LTD4), a representative CysLT, is implicated in promoting lung inflammation and remodelling in allergic asthma, but its role in non-allergic asthma, especially in obese-asthmatic patients, is not known. Here, using primary human small airway epithelial cells (SAECs) we have investigated the mechanism of LTD4-induced inflammation and remodelling and assessed high proneness of obese mice to develop asthma upon challenge with allergen ovalbumin (OVA). METHODS: Primary human small airway epithelial cells (SAECs) were stimulated with different concentrations of LTD4 for different time intervals and various inflammatory markers were measured through cytokine array, membrane-based ELISA and Western blotting. An air-liquid interface (ALI) model of SAECs was used to study the effects of LTD4-induced remodelling in SAECs using Western blotting, H&E staining and PAS staining. Further, OVA-based murine model was used to examine the propensity of high-fat diet (HFD)-fed obese mice to develop asthma symptoms by studying the infiltration of inflammatory cells (assessed by bronchioalveolar lavage (BAL) cytology) and airway remodelling (assessed by histopathology) upon allergen exposure. RESULTS: The human primary small airway epithelial cells (SAECs) treated with LTD4 showed significant alterations in the levels of inflammatory markers such as GM-CSF, TNF-α, IL-1ß, EGF and eotaxin in dose- and time-dependent manner. Further, LTD4 enhanced the activation of inflammasomes as evidenced by increased levels of NALP3, cleaved caspase-1 and IL-1ß. LTD4 also enhanced inflammation by increasing the expression of COX-2 in SAECs. The airway remodelling markers Vimentin and Muc5AC were found elevated in ALI culture of SAECs when stimulated with LTD4, as it also increased TGF-ß levels and activation of Smad2/3 phosphorylation in SAECs. Last, sensitization and challenge of HFD-fed obese mice with OVA showed increased infiltration of inflammatory cells in BAL and enhanced levels of remodeling phenotypes like loss of cilia, mucus cell metaplasia and collagen deposition in mice lung tissues. CONCLUSION: The results suggest that LTD4 could induce inflammatory response in human airway epithelial cell by activating NALP3 inflammasome. LTD4 could further promote airway epithelial cells' remodelling through TGF-ß/smad2/3-mediated pathway. Our in vivo results suggested that obesity predisposed the OVA challenged mice to develop lung inflammation and remodelling akin to asthma-like phenotypes during obesity.

The Interplay between Transcriptional Factors and MicroRNAs as an Important Factor for Th17/Treg Balance in RA Patients.

MicroRNAs regulate gene expression of transcriptional factors, which influence Th17/Treg (regulatory T cells) balance, establishing the molecular mechanism of genetic and epigenetic regulation of Treg and Th17 cells is crucial for understanding rheumatoid arthritis (RA) pathogenesis. The study goal was to understand the potential impact of the selected microRNAs expression profiles on Treg/Th17 cells frequency, RA phenotype, the expression profile of selected microRNAs, and their correlation with the expression profiles of selected transcriptional factors: SOCS1, SMAD3, SMAD4, STAT3, STAT5 in RA; we used osteoarthritis (OA) and healthy controls (HCs) as controls. The study was conducted on 14 RA and 11 OA patients, and 15 HCs. Treg/Th17 frequency was established by flow cytometry. Gene expression analysis was estimated by qPCR. We noticed correlations in RA Th17 cells between miR-26 and SMAD3, STAT3, SOCS1; and miR-155 and STAT3-and in RA Treg cells between miR-26 and SOCS1; miR-31, -155 and SMAD3; and miR-155 and SMAD4. In RA Tregs, we found a negative correlation between miR-26, -126 and STAT5a. The expression level of miR-31 in Th17 cells from RA patients with DAS28 ≤ 5.1 is higher and that for miR-24 is greater in Tregs from patients with DAS28 > 5.1. MiR-146a in Tregs is higher in rheumatoid factor (RF) positive RA patients.

Dichotomous role of TGF-ß controls inducible regulatory T-cell fate in allergic airway disease through Smad3 and TGF-ß-activated kinase 1.

BACKGROUND: Inducible CD4+CD25+ regulatory T (iTreg) cells can become pathogenic effector cells, enhancing lung allergic responses. OBJECTIVE: We aimed to define the underlying cellular and molecular pathways activated by TGF-ß, which determine the suppressor or enhancing activities of iTreg cells. METHODS: Sensitized wild-type and CD8-deficient (CD8-/-) mice were challenged with allergen. Isolated CD4+CD25- T cells were activated by using anti-CD3/anti-CD28. To generate suppressor iTreg cells, cells were then differentiated in the presence of TGF-ß, whereas IL-17-producing effector T cells were additionally exposed to IL-6. After TGF-ß, Smad3 and TGF-ß-activated kinase 1 (TAK1) kinase levels were monitored. The consequences of inhibiting either kinase were determined in vitro and after transfer into CD8-/- recipients. Quantitative PCR and chromatin immunoprecipitation were used to monitor gene expression and histone modifications at the retinoic acid-related orphan receptor γt (Rorγt) locus. RESULTS: In wild-type mice, iTreg cells suppressed lung allergic responses linked to Smad3-dependent forkhead box P3 (Foxp3) expression and IL-10 production. In the presence of IL-6, iTreg cells converted to TH17 cells, mediating a neutrophil-dependent enhancement of lung allergic responses in CD8-/- mice. Conversion was regulated by TAK1. Inhibition or silencing of TAK1 prevented expression of Rorγt and TH17 differentiation through histone modifications of Rorγt; Foxp3 expression and iTreg cell-mediated suppression remained intact. In the same cell, TGF-ß induced coexpression of Smad3 and TAK1 proteins; in the presence of IL-6, expression of Smad3 and Foxp3 but not TAK1 decreased. CONCLUSION: TGF-ß regulates iTreg cell outcomes through 2 distinct signal transduction pathways: one Smad3 dependent and the other TAK1 dependent. The balance of these pathways has important implications in TH17-mediated autoimmune diseases and neutrophil-dependent asthma.

Berberine Attenuates Cigarette Smoke Extract-induced Airway Inflammation in Mice: Involvement of TGF-ß1/Smads Signaling Pathway.

Although several studies confirmed that berberine may attenuate airway inflammation in mice with chronic obstructive pulmonary disease (COPD), its underlying mechanisms were not clear until now. We aimed to establish an experiment mouse model for COPD and to investigate the effects of berberine on airway inflammation and its possible mechanism in COPD model mice induced by cigarette smoke extract (CSE). Twenty SPF C57BL/6 mice were randomly divided into PBS control group, COPD model group, low-dose berberine group and high-dose berberine group, 5 mice in each group. The neutrophils and macrophages were examined by Wright's staining. The levels of inflammatory cytokines TNF-α and IL-6 in bronchoalveolar lavage fluid (BALF) were determined by enzyme-linked immunosorbent assay. The expression levels of TGF-ß1, Smad2 and Smad3 mRNA and proteins in lung tissues were respectively detected by quantitative real-time polymerase chain reaction and Western blotting. It was found that CSE increased the number of inflammation cells in BALF, elevated lung inflammation scores, and enhanced the TGF-ß1/Smads signaling activity in mice. High-dose berberine restrained the alterations in the COPD mice induced by CSE. It was concluded that high-dose berberine ameliorated CSE-induced airway inflammation in COPD mice. TGF-ß1/Smads signaling pathway might be involved in the mechanism. These findings suggested a therapeutic potential of high-dose berberine on the CSE-induced airway inflammation.

Methyl helicterilate ameliorates alcohol-induced hepatic fibrosis by modulating TGF-ß1/Smads pathway and mitochondria-dependent pathway.

This study aimed to investigate the effect and underlying mechanism of Methyl helicterilate from Helicteres angustifolia (MHHA) on alcohol-induced hepatic fibrosis. The results showed that MHHA treatment markedly alleviated alcohol-induced liver injury and notably reduced collagen deposition in liver tissue. It significantly enhanced the activity of alcohol dehydrogenase and aldehyde dehydrogenase. Moreover, MHHA treatment markedly decreased the content of inflammatory cytokines, alleviated collagen accumulation, and inhibited the expression of TGF-ß1 and Smad2/3 in liver tissue. The experiments in cells showed that MHHA significantly inhibited HSC activation by blocking TGF-ß1/Smads signaling pathway. Additionally, it notably induced HSC apoptosis by modulating the mitochondria-dependent pathway. The present study demonstrates that MHHA treatment significantly ameliorates alcoholic hepatic fibrosis and the underlying mechanism may be ascribed to the inhibition of the TGF-ß1/Smads pathway and regulation of the mitochondria-mediated apoptotic pathway.

Paeonol alleviates CCl4-induced liver fibrosis through suppression of hepatic stellate cells activation via inhibiting the TGF-ß/Smad3 signaling.

Objective: Paeonol is a natural phenolic component isolated from the root bark of peony with multiple pharmacological activities. We investigated the anti-fibrotic effect and underlying mechanism of paeonol. Methods: Twenty-four male C57BL/6J mice were divided into 4 groups (n = 6 in each group), injected with CCl4 to induce liver fibrosis and administrated with paeonol according to the regimen. The serum activity of ALT and AST, and H&E staining were to assess liver injury. Sirius and Masson staining, and hydroxyproline content were to evaluate the degree of liver fibrosis. TNF-α, IL-6, TGF-ß, MDA, GSH-PX, SOD, and CAT were detected to reflect inflammation and oxidative stress. RT-qPCR and Western blot analysis to assess the activation of HSCs and TGF-ß/Smad3 signaling. Results: Paeonol ameliorated liver injury and liver fibrosis, reflected by the decrease of ALT, AST, less lesion in H&E staining, mitigated fibrosis in Sirius and Masson staining, lessened content of hydroxyproline. Paeonol attenuated the level of IL-6 and TNF-α, and elevated the activity of GSH-PX, SOD, and CAT with reducing the level of MDA. The expression of col 1a, α-SMA, vimentin, and desmin were down-regulated and TGF-ß/Smad3 signaling pathway was inhibited. Conclusion: These data demonstrated that paeonol could alleviate CCl4-induced liver fibrosis through suppression of hepatic stellate cells activation via inhibiting the TGF-ß/Smad3 signaling.

MicroRNA-216a promotes M1 macrophages polarization and atherosclerosis progression by activating telomerase via the Smad3/NF-κB pathway.

Macrophages exhibit heterogeneity and plasticity and imbalance between pro-inflammatory and anti-inflammatory macrophages plays a critical role in atherosclerosis progression. Telomerase reverse transcriptase (TERT) in macrophages can be activated by nuclear factor-kappa B (NF-κB), but the regulation of telomerase activation on macrophages polarization remains unknown. We previously identified microRNA-216a (miR-216a) to promote inflammation through directly targeting the Smad3/NF-κB pathway. The present study aimed to assess whether miR-216a can regulate telomerase activity and promote macrophages polarization during atherosclerosis progression. The results verified that TERT was highly expressed in macrophages of human carotid atherosclerotic plaques. miR-216a was found to promote telomerase activation in macrophages by 4.5-fold (P = 0.002) through the Smad3/NF-κB pathway. miR-216a also induced macrophages senescence characterized by senescence-associated-ß-galactosidase activity and p53 and p16 expression. TERT overexpression promoted the transformation of M2 to M1 while this conversion was suppressed once TERT was inhibited, and the related inflammatory factors and lipid uptake ability of M1 cells were also increased by TERT. In the carotid atherosclerotic plaques from miR-216a-treated apolipoprotein E-/- mice, the numbers of M1 macrophages were increased whereas M2 cells reduced, accompanying with inhibited Smad3 expression and upregulated inflammatory markers and TERT activity. Furthermore, plasma miR-216a level was specifically higher in patients with vulnerable mixed plaques (n = 181) than those with calcified plaques (n = 73) and controls (n = 264). In summary, our findings first revealed a new molecular mechanism of macrophage polarization involving telomerase activation induced by miR-216a through the Smad3/NF-κB signaling, which might serve as a potential therapeutic target for atherosclerosis progression.

Adoptive Transfers of CD4+CD25+ Tregs Raise Foxp3 Expression and Alleviate Mouse Enteritis.

CD4+CD25+Foxp3+ Tregs control the immune response and maintain immune homeostasis. This study examined whether Tregs can affect mouse enteritis and the Foxp3 (Forkhead transcription factor) transcriptional pathway. Mouse CD4+CD25+ Treg cells were labelled using CFSE (5,6-carboxyfluorescein diacetate succinimidyl ester) and transferred to enteritis model mice. The mice were randomly divided into an enteritis group, a Treg-infusion group, a Treg-inhibiting group, and a control group. Histopathology, ELISA, flow cytometry, western blot, immunohistochemistry, and immunofluorescence were performed. Our results demonstrated that CD4+CD25+ Tregs were successfully transferred. The disease activity index (DAI) scores in the Tregs-infusion group were lower than those of the enteritis and Tregs-inhibiting groups. The number of goblet cells and inflammatory cells was reduced, and the levels of IL-1ß, TNF-α, NO, and PGE2 were significantly decreased in the Tregs-infusion group compared to those in the enteritis group (p<0.05). The number of CD4+CD25+Foxp3+ Tregs and CD4+IL-17A+ Th17 cells in the mesenteric lymph nodes differed significantly from the enteritis and Tregs-inhibiting groups (p<0.05). There were more Foxp3+ Tregs and Smad3 and NFAT2 infiltrated into the duodenum after adoptive transfer of CD4+CD25+ Tregs, which was a significant difference relative to the enteritis group (p<0.05). This study demonstrated that adoptive transfer of CD4+CD25+ Tregs can decrease mouse enteritis. Foxp3 expression may be improved through the Smad3 and NFAT2 signalling pathways.

Enhanced Cancer Immunotherapy with Smad3-Silenced NK-92 Cells.

Natural killer (NK) cells, early effectors in anticancer immunity, are paralyzed by TGFß1, an immunosuppressive cytokine produced by cancer cells. Development and activity of NK cells are largely inhibited in the Smad3-dependent tumor microenvironment. Here, we used genetic engineering to generate a stable SMAD3-silencing human NK cell line, NK-92-S3KD, whose cancer-killing activity and cytokine production were significantly enhanced under TGFß1-rich condition compared with the parental cell line. Interestingly, we identified that the IFNG gene is a direct E4BP4 target gene. Thus, silencing of SMAD3 allows upregulation of E4BP4 that subsequently promoting interferon-γ (IFNγ) production in the NK-92-S3KD cells. More importantly, NK-92-S3KD immunotherapy increases the production of not only IFNγ, but also granzyme B and perforin in tumors; therefore, inhibiting cancer progression in two xenograft mouse models with human hepatoma (HepG2) and melanoma (A375). Thus, the NK-92-S3KD cell line may be useful for the clinical immunotherapy of cancer. Cancer Immunol Res; 6(8); 965-77. ©2018 AACR.

Epigallocatechin gallate improves airway inflammation through TGF­ß1 signaling pathway in asthmatic mice.

The present study aimed to investigate the effect of epigallocatechin gallate (EGCG) on airway inflammation in mice with bronchial asthma, and the regulatory mechanism of transforming growth factor (TGF)­ß1 signaling pathway, so as to provide theoretical basis for research and development of a novel drug for clinical treatment. Mouse models of bronchial asthma were established and injected with dexamethasone and EGCG via the caudal vein. 7 days later, bronchoalveolar tissue was collected for hematoxylin and eosin staining. Determination of airway resistance (AWR) and lung function in mice was detected. Serum was separated for cytometric bead array to detect the changes in inflammatory factors. Bronchoalveolar lavage fluid was collected for eosinophil and neutrophil counts. Fresh blood was obtained for flow cytometry to determine the percentages of Th17 and Treg cells. Bronchovesicular tissue was utilized for western blot assay and reverse transcription­quantitative polymerase chain reaction to determine the proteins and transcription factors in the TGF­ß1 pathway. EGCG 20 mg/kg significantly reduced asthmatic symptoms, lung inflammatory cell infiltration, and the inflammatory factor levels of interleukin (IL)­2, IL­6 and tumor necrosis factor (TNF)­α. In addition, it increased the levels of inflammatory factors, including IL­10, diminished the percentage of Th17 cells, increased the percentage of Treg cells, and decreased the expression of TGF­ß1 and phosphorylated (p)­Smad2/3 expression. Following the inhibition of the TGF­ß1 receptor, the anti­inflammatory effect of EGCG disappeared, and the expression of TGF­ß1 and p­Smad2/3 increased. EGCG attenuated airway inflammation in asthmatic mice, decreased the percentage of Th17 cells and increased the percentage of Treg cells. The anti­inflammatory effect of EGCG is achieved via the TGF­ß1 signaling pathway.

TGF-ß1/Smad2/3/Foxp3 signaling is required for chronic stress-induced immune suppression.

Depending on the duration and severity, psychological tension and physical stress can enhance or suppress the immune system in both humans and animals. Although it has been established that chronic stress exerts a significant suppressive effect on immune function, the mechanisms by which affects immune responses remain elusive. By employing an in vivo murine system, we revealed that TGF-ß1/Smad2/3/Foxp3 axis was remarkably activated following chronic stress. Furthermore, TLR9 and p38 MAPK played a critical role in the activation of TGF-ß1/Smad2/3/Foxp3 signaling cascade. Moreover, inhibition of TGF-ß1/Smad2/3/Foxp3 or p38 significantly attenuated chronic stress-induced lymphocyte apoptosis and apoptosis-related proteins, as well as the differentiation of T regulatory cells in spleen. Interestingly, disequilibrium of pro-inflammatory and anti-inflammatory cytokines balance caused by chronic stress was also rescued by blocking TGF-ß1/Smad2/3/Foxp3 axis. These findings yield insight into a novel mechanism by which chronic stress modulates immune functions and identifies new targets for the development of novel anti-immune suppressant medications.

[Reprogrammed M1 macrophages with inhibited STAT3, STAT6 and/or SMAD3 extends lifespan of mice with experimental carcinoma].

Objective. Reprogramming of M1 macrophage phenotype with inhibited M2 phenotype transcription factors, such as STAT3, STAT6 and SMAD and assess their impact on the development of Ehrlich carcinoma (EC) in vitro and in vivo. Methods. Tumor growth in vitro was initiated by addition of EC cells in RPMI-1640 culture medium and in vivo by intraperitoneal of EC cell injection into mice. Results. It was found that M1-STAT3/6- SMAD3 macrophages have a pronounced anti-tumor effect in vitro, and in vivo, which was greater than anti-tumor effects of M1, M1-STAT 3/6, M1-SMAD3 macrophages and cisplatin. Conclusion. M1 macrophages with inhibited STAT3, STAT6 and/or SMAD3 effectively restrict tumor growth. The findings justify the development of new anti-tumor cell therapy technology.

Beyond disease susceptibility-Leveraging genome-wide association studies for new insights into complex disease biology.

Genetic studies in complex diseases have been highly successful, but have also been largely one-dimensional: predominantly focusing on the genetic contribution to disease susceptibility. While this is undoubtedly important-indeed it is a pre-requisite for understanding the mechanisms underlying disease development-there are many other important aspects of disease biology that have received comparatively little attention. In this review, I will discuss how existing genetic data can be leveraged to provide new insights into other aspects of disease biology, why such insights could change the way we think about complex disease, and how this could provide opportunities for better therapies and/or facilitate personalised medicine. To do this, I will use the example of Crohn's disease-a chronic form of inflammatory bowel disease that has been one of the main success stories in complex disease genetics. Indeed, thanks to genetic studies, we now have a much more detailed understanding of the processes involved in Crohn's disease development, but still know relatively little about what determines the subsequent disease course (prognosis) and why this differs so considerably between individuals. I will discuss how we came to realise that genetic variation plays an important role in determining disease prognosis and how this has changed the way we think about Crohn's disease genetics. This will illustrate how phenotypic data can be used to leverage new insights from genetic data and will provide a broadly applicable framework that could yield new insights into the biology of multiple diseases.

Mechanism of chimeric vaccine stimulation of indoleamine 2,3-dioxygenase biosynthesis in human dendritic cells is independent of TGF-ß signaling.

Cholera toxin B subunit fusion to autoantigens such as proinsulin (CTB-INS) down regulate dendritic cell (DC) activation and stimulate synthesis of DC immunosuppressive cytokines. Recent studies of CTB-INS induction of immune tolerance in human DCs indicate that increased biosynthesis of indoleamine 2,3-dioxygenase (IDO1) may play an important role in CTB-INS vaccine suppression of DC activation. Studies in murine models suggest a role for transforming growth factor beta (TGF-ß) in the stimulation of IDO1 biosynthesis, for the induction of tolerance in DCs. Here, we investigated the contribution of TGF-ß superfamily proteins to CTB-INS induction of IDO1 biosynthesis in human monocyte-derived DCs (moDCs). We show that CTB-INS upregulates the level of TGF-ß1, activin-A and the TGF-ß activator, integrin αvß8 in human DCs. However, inhibition of endogenous TGF-ß, activin-A or addition of biologically active TGF-ß1, and activin-A, did not inhibit or stimulate IDO1 biosynthesis in human DCs treated with CTB-INS. While inhibition with the kinase inhibitor, RepSox, blocked SMAD2/3 phosphorylation and diminished IDO1 biosynthesis in a concentration dependent manner. Specific blocking of the TGF-ß type 1 kinase receptor with SB-431542 did not arrest IDO1 biosynthesis, suggesting the involvement of a different kinase pathway other than TGF-ß type 1 receptor kinase in CTB-INS induction of IDO1 in human moDCs. Together, our experimental findings identify additional immunoregulatory proteins induced by the CTB-INS fusion protein, suggesting CTB-INS may utilize multiple mechanisms in the induction of tolerance in human moDCs.

Polydatin alleviated radiation-induced lung injury through activation of Sirt3 and inhibition of epithelial-mesenchymal transition.

Radiation-induced lung injury (RILI) is one of the most common and fatal complications of thoracic radiotherapy. It is characterized with two main features including early radiation pneumonitis and fibrosis in later phase. This study was to investigate the potential radioprotective effects of polydatin (PD), which was shown to exert anti-inflammation and anti-oxidative capacities in other diseases. In this study, we demonstrated that PD-mitigated acute inflammation and late fibrosis caused by irradiation. PD treatment inhibited TGF-ß1-Smad3 signalling pathway and epithelial-mesenchymal transition. Moreover, radiation-induced imbalance of Th1/Th2 was also alleviated by PD treatment. Besides its free radical scavenging capacity, PD induced a huge increase of Sirt3 in culture cells and lung tissues. The level of Nrf2 and PGC1α in lung tissues was also elevated. In conclusion, our data showed that PD attenuated radiation-induced lung injury through inhibiting epithelial-mesenchymal transition and increased the expression of Sirt3, suggesting PD as a novel potential radioprotector for RILI.

Ash1l and lnc-Smad3 coordinate Smad3 locus accessibility to modulate iTreg polarization and T cell autoimmunity.

Regulatory T (Treg) cells are important for the maintenance of immune homoeostasis and prevention of autoimmune diseases. Epigenetic modifications have been reported to modulate autoimmunity by altering Treg cell fate. Here we show that the H3K4 methyltransferase Ash1l facilitates TGF-ß-induced Treg cell polarization in vitro and protects mice from T cell-mediated colitis in vivo. Ash1l upregulates Smad3 expression by directly targeting Smad3 promoter to increase local H3K4 trimethylation. Furthermore, we identify an lncRNA, namely lnc-Smad3, which interacts with the histone deacetylase HDAC1 and silences Smad3 transcription. After TGF-ß stimulation, activated Smad3 suppresses lnc-Smad3 transcription, thereby recovering the Smad3 promoter accessibility to Ash1l. By revealing the opposite regulatory functions of Ash1l and lnc-Smad3 in Smad3 expression, our data provide insights for the epigenetic control of Treg cell fate to potentially aid in the development of therapeutic intervention for autoimmune diseases.

The emerging role of interleukin-37 in cardiovascular diseases.

INTRODUCTION: Interleukin (IL)-37 is a newly identified member of the IL-1 family, and shows a growing role in a variety of diseases. This review aims at summarizing and discussing the role of IL-37 in cardiovascular diseases. METHODS: Data for this review were identified by searches of MEDLINE, Embase, and PubMed using appropriate search terms. RESULTS: IL-37 is a newly identified cytokine belonging to the IL-1 family and is expressed in inflammatory immune cells and several parenchymal cells. It has potent anti-inflammatory and immunosuppressive properties, with two mechanisms underlying this function. IL-37 is produced as a precursor and then cleaved into mature form in the cytoplasm by caspase-1, translocating to nucleus and suppressing the transcription of several pro-inflammatory genes by binding SMAD-3. Besides, IL-37 can be secreted extracellularly, and binds to IL-18Ra chain and recruits Toll/IL-1R (TIR)-8 for transducing anti-inflammatory signaling. IL-37 is upregulated in an inducible manner and negatively regulates signaling mediated by TLR agonists and pro-inflammatory cytokines. The cytokine has been shown to inhibit both innate and adaptive immunological responses, exert antitumor effects, and act as a prognostic marker in a variety of autoimmune diseases. CONCLUSIONS: Recent studies have suggested that IL-37 plays a role in cardiovascular diseases. In this review, we provide an overview of the cytokine biology, discuss recent advances made in unraveling its cardio-protective effects, and suggest guidelines for future research.