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Thymic stromal lymphopoietin presents in two distinct isoforms: short-form (sfTSLP) and long-form (lfTSLP). lfTSLP promotes inflammation, whereas sfTSLP inhibits inflammation, in allergic asthma. However, little is known about the regulation of lfTSLP and sfTSLP during allergic attack in the asthma airway epithelium. Here, we report that small ubiquitin-like modifier (SUMOylation) was enhanced in house dust mite-induced allergic asthma airway epithelium. Inhibition of SUMOylation significantly alleviated airway T-helper cell type 2 inflammation and lfTSLP expression. Mechanistically, chromobox 4 (CBX4), a SUMOylation E3 ligase, enhanced lfTSLP mRNA translation, but not sfTSLP, through the RNA-binding protein muscle excess (MEX)-3B. MEX-3B promoted lfTSLP translation by binding the lfTSLP mRNA through its K homology domains. Furthermore, CBX4 regulated MEX-3B transcription in human bronchial epithelial cells through enhancing SUMOylation concentrations of the transcription factor TFII-I. In conclusion, we demonstrate an important mechanism whereby CBX4 promotes MEX-3B transcription through enhancing TFII-I SUMOylation and MEX-3B enhances the expression of lfTSLP through binding to the lfTSLP mRNA and promoting its translation. Our findings uncover a novel target of CBX4 for therapeutic agents for lfTSLP-mediated asthma.

Background: Thymic stromal lymphopoietin (TSLP) is present in two distinct isoforms, short-form (sfTSLP) and long-form (lfTSLP). lfTSLP promotes inflammation while sfTSLP inhibits inflammation in allergic asthma. However, little is known about the regulation of lfTSLP and sfTSLP during allergic attack in asthma airway epithelium. Methods and Results: Here, we report that SUMOylation was enhanced in HDM-induced allergic asthma airway epithelium. Inhibition of SUMOylation significantly alleviated airway Th2 inflammation and lfTSLP expression. Mechanistically, CBX4, a SUMOylation E3 ligase, enhanced lfTSLP, but not sfTSLP, mRNA translation through the RNA binding protein, MEX-3B. MEX-3B promoted lfTSLP translation through binding of its KH domains to the lfTSLP mRNA. Furthermore, CBX4 regulated MEX-3B transcription in HBE through enhancing SUMOylation levels of the transcription factor, TFII-I. Conclusion: We demonstrate an important mechanism whereby CBX4 promotes MEX-3B transcription through enhancing TFII-I SUMOylation, and MEX-3B enhances the expression of lfTSLP through binding to the lfTSLP mRNA and promoting its translation. Our findings uncover a novel target of CBX4 for therapeutic agents to lfTSLP-mediated asthma.

Background Up-regulation of aerobic glycolysis has been reported as a characterization of asthma and facilitates airway inflammation. We has been previously reported that short isoform thymic stromal lymphopoietin (sTSLP) could reduce inflammation in asthmatic airway epithelial cells. Here we wanted to investigate whether the inhibition of sTSLP on asthma is related to aerobic glycolysis. Methods Asthmatic model was established in challenging Male BALB/c mice and 16-HBE (human bronchial epithelial) cell line with house dust mite (HDM). Indicators of glycolysis were assessed to measure whether involve in sTSLP regulating airway epithelial cells inflammation in asthmatic model in vivo and in vitro. Results sTSLP decreased inflammation of asthmatic airway and aerobic glycolysis in mice. HDM or long isoform thymic stromal lymphopoietin (lTSLP) promoted HIF-1α expression and aerobic glycolysis by miR-223 to target and inhibit VHL (von Hippel-Lindau) expression 16-HBE. Inhibition of aerobic glycolysis restrained HDM- and lTSLP-induced inflammatory cytokines production. sTSLP along had almost no potential to alter aerobic glycolysis of 16-HBE. But sTSLP decreased LDHA (lactate dehydrogenase A) and LD (Lactic acid) levels in BALF, and HIF-1α and LDHA protein levels in airway epithelial cells of asthma mice model. lTSLP and sTSLP both induced formation of TSLPR and IL-7R receptor complex, and lTSLP obviously facilitated phosphorylation of JAK1, JAK2 and STAT5, while sTSLP induced a little phosphorylation of JAK1 and STAT5. Conclusion We identified a novel mechanism that lTSLP could promote inflammatory cytokines production by miR-223/VHL/HIF-1α pathway to upregulate aerobic glycolysis in airway epithelial cells in asthma. This pathway is suppressed by sTSLP through occupying binding site of lTSLP in TSLPR and IL-7R receptor complex.

Supplemental figures of "Blockade of ��-catenin SUMOylation attenuates house dust mite-induced airway epithelial barrier dysfunction,"

Supplemental figures of "Blockade of β-catenin SUMOylation attenuates house dust mite-induced airway epithelial barrier dysfunction,"

Epithelial barrier dysfunction is involved in the pathogenesis of asthma. Previous studies show that SUMOylation can regulate epithelial junction molecule localization. However, the role of SUMOylation in epithelial barrier dysfunction in asthma remains unclear. This study found that inhibition of SUMOylation attenuates house dust mite (HDM)-induced epithelial barrier dysfunction. The SUMOylation levels of junction molecules were determined by co-immunoprecipitation (CO-IP) and proximity ligation assay (PLA). HDM treatment significantly enhanced SUMOylation levels of β-catenin, while no effect was seen on ZO-1, Occludin, and E-cadherin SUMOylation levels. Inhibition of β-catenin SUMOylation through 2-D08 treatment or SUMOylation modification site mutant (K233A) promoted its membrane localization and repressed Wnt/β-catenin signaling. Further, we identified that CBX4, an E3 ligase, mediated SUMOylation of β-catenin. Knockdown of CBX4 promoted β-catenin membrane localization and improved epithelial barrier function. In vivo analysis showed that AAV6-shCBX4-mediated knockdown of CBX4 attenuated HDM-induced allergic airway inflammation and epithelial barrier dysfunction. The findings showed that inhibiting β-catenin SUMOylation by targeting CBX4 mitigated HDM-induced epithelial barrier dysfunction in asthma.

Avasimibe (Ava) is an acetyl-CoA acetyltransferase 1 (ACAT1) specific inhibitor and an established medicine for atherosclerosis, owing to its excellent and safe anti-inflammation effects in humans. However, its efficacy in asthma has not yet been reported. We first administered varying concentrations of avasimibe to house dust mite (HDM)-induced asthmatic mice; results showed that 20 mg/kg avasimibe most significantly reduced IL-4 and IL-5 production in bronchoalveolar lavage fluid (BALF) and total IgE in serum, and the avasimibe treatment also exhibited lower mucus secretion, decreased goblet and basal cells but increased ciliated cells compared to the HDM group. And the redistribution of adherens junction (AJ) proteins induced by HDM was far more less upon avasimibe administration. However, avasimibe did not reduce the cholesterol ester ratio in lung tissues or intracellular cholesterol ester, which is avasimibe’s main effect. Further analysis confirmed that avasimibe impaired epithelial basal cell proliferation independent of regulating cholesterol metabolism and we analyzed datasets using the Gene Expression Omnibus (GEO) database and then found that the KRT5 gene (basal cell marker) expression is correlated with the β-catenin gene. Moreover, we found that β-catenin localized in cytomembrane upon avasimibe treatment. Avasimibe also reduced β-catenin phosphorylation in the cytoplasm and inactivated the Wnt/β-catenin signaling pathway induced by HDMs, thereby alleviating the airway epithelial barrier disruption. Taken together, these findings indicated that avasimibe has potential as a new therapeutic option for allergic asthma.

RationaleThymic stromal lymphopoietin (TSLP) is present in two distinct isoforms, short-form (sfTSLP) and long-form (lfTSLP). lfTSLP promotes inflammation while sfTSLP inhibits inflammation in allergic asthma. However, little is known about the regulation of lfTSLP and sfTSLP during allergic attack in asthma airway epithelium.Methods and ResultsHere, we report that SUMOylation was enhanced in HDM-induced allergic asthma airway epithelium. Inhibition of SUMOylation significantly alleviated airway Th2 inflammation and lfTSLP expression. Mechanistically, CBX4, a SUMOylation E3 ligase, enhanced lfTSLP, but not sfTSLP, mRNA translation through the RNA binding protein, MEX-3B. MEX-3B promoted lfTSLP translation through binding of its KH domains to the lfTSLP mRNA. Furthermore, CBX4 regulated MEX-3B transcription in HBE through enhancing SUMOylation levels of the transcription factor, TFII-I.ConclusionWe demonstrate an important mechanism whereby CBX4 promotes MEX-3B transcription through enhancing TFII-I SUMOylation, and MEX-3B enhances the expression of lfTSLP through binding to the lfTSLP mRNA and promoting its translation. Our findings uncover a novel target of CBX4 for therapeutic agents to lfTSLP-mediated asthma.

Background: Asthma is a complex and heterogeneous disease. Autophagy, process of self-protection in cells, is an intracellular process when cells are being attacked by certain stress. Our team focused upon the disruption of airways epithelial barrier in asthma, and we interested in whether autophagy played a key role in asthma. Methods: 400U HDM was used to treat HBECs and established asthmatic mice model. Western blotting, RT-PCR and immunofluorescence were mainly used to detect autophagy process in vivo and in vitro. One way ANOVA and Mann Whitney test were used for statistic. Results: After treated with HDM, expression of LC3ab increased in vivo and in vitro. Using Rapamycin, 3-MA and Chloroquine to treat HBECs, then we surprisingly found that HDM disrupts epithelial barrier through incomplete autophagy. To find out the connection between asthma and autophagy, we chose known autophagy related genes to determine the association between autophagy and disruption of airway epithelial barrier. Atg5 and atg12 were chosen because these two genes varied upon the time dependent manner. Knocked down the expression of atg5 or atg12 by siRNA, the expression of TSLP, which can induce the disruption of airway epithelial barrier, remarkably reduced. Conclusions: These results demonstrated that HDM induced inflammatory in airway epithelium through autophagy, and then knocked down autophagy related genes alleviated the inflammatory in HBECs.

Background: Up-regulation of aerobic glycolysis has been reported as a characterization of asthma and facilitates airway inflammation. Thymic stromal lymphopoietin (TSLP) has been previously reported to have dual immunoregulatory roles due to long and short isoform (lTSLP and sTSLP) in asthma. However, their role in aerobic glycolysis in asthma airway epithelial was poorly defined. Methods: Asthmatic model was established in challenging Male BALB/c mice and 16-HBE (human bronchial epithelial) cell line with house dust mite (HDM). Indicators of glycolysis were assessed to measure whether involve in lTSLP and sTSLP regulating airway epithelial inflammation in asthmatic model in vivo and in vitro. Results: lTSLP promoted the enhancement of aerobic glycolysis as well as HDM in 16-HBE. HIF-1α was increased significantly in 16-HBE growing with lTSLP which suppressed VHL expression by promoting miR-223 expression. Inhibition of aerobic glycolysis restrained HDM- and lTSLP-induced inflammatory cytokines production. sTSLP had almost no potential to alter aerobic glycolysis of 16-HBE alone but might have prevented effects of lTSLP in 16-HBE, decreased LDH and LD in BALF, and HIF-1α and LDHA in airway epithelial of asthma mouse model. lTSLP and sTSLP both induced formation of TSLPR and IL-7R receptor complex, and lTSLP obviously facilitated phosphorylation of JAK1, JAK2 and STAT5, while sTSLP induced a little phosphorylation of JAK1 and STAT5. Conclusion: We identified a novel mechanism that lTSLP could promote inflammatory cytokines production by miR-223/VHL/HIF-1α pathway to upregulate aerobic glycolysis in airway epithelial in asthma. This pathway is suppressed by sTSLP through occupying binding site of lTSLP in TSLPR and IL-7R receptor complex. Funding Statement: This study was supported by the National Natural Science Foundation of China (81700034， 81670026, 81470228，81770033, 81500023), Natural Science Foundation of Guangdong Province (2017A030310106, 2015A030313236, 2017A030313849), the Precision Medicine Research of The National Key Research and Development Plan of China (2016YFC0905803), and China Postdoctoral Science Foundation (2017M620377, 2018T110885). Declaration of Interests: The authors declare that they have no conflicts of interest. Ethics Approval Statement: The asthmatic models experiment were approved by the Animal Subjects Committee of South Medical University.

MicroRNA-181b (miR-181b) has been well noted with anti-inflammatory properties in several pathological conditions. It has also been suggested to be downregulated in patients with asthma. In this study, we explored the function of miR-181b in airway remodeling in asthmatic mice and the molecular mechanism. A mouse model with asthma was induced by ovalbumin (OVA) challenge, and miR-181b was found to be downregulated in lung tissues in the OVA-challenged mice. Overexpression of miR-181b was introduced in mice, after which the respiratory resistance, inflammatory infiltration, mucus production, and epithelial-mesenchymal transition (EMT) and fibrosis in mouse airway tissues were decreased. The integrated bioinformatics analysis suggested long non-coding RNA (lncRNA) TUG1 as a sponge for miR-181b. miR-181 directly targeted high mobility group box 1 (HMGB1) mRNA. HMGB1 was suggested to enhance activation of the nuclear factor kappa B (NF-κB) signaling. Further upregulation of lncRNA TUG1 blocked the protective functions of miR-181b in asthmatic mice. To conclude, this study evidenced that lncRNA TUG1 reinforces HMGB1 expression through sequestering microRNA-181b, which activates the NF-κB signaling pathway and promotes airway remodeling in asthmatic mice. This study may provide novel ideas in asthma management.

Sea cucumbers belong to the Class Holothuroidea of marine invertebrates. They are commercially valuable and prized as a food and folk medicine in Asia. Nutritionally, sea cucumbers have an impressive profile of valuable nutrients such as vitamins, minerals and amino acids. A number of unique biological and pharmacological activities/properties, including anticancer, anticoagulant/antithrombotic, antimicrobial, antioxidant, antihyperlipidemic, antihyperglycemic, anti-inflammatory, antihypertension and radioprotective, have been ascribed to various compounds isolated from sea cucumbers. The therapeutic properties and medicinal benefits of sea cucumbers can be linked to the presence of a wide array of bioactives, especially triterpene glycosides, acid mucopolysaccharide, sphingoid bases, glycolipids, fucosylated chondroitin sulfate, polysaccharides, phospholipids, cerebrosides, phosphatidylcholines, and other extracts and hydrolysates. This review highlights the valuable bioactive components as well as the multiple therapeutic properties of sea cucumbers with a view to exploring their potential uses as functional foods and a natural source of new multifunctional drugs.