Protective Effects of Interleukin-37 Expression against Acetaminophen-Induced Hepatotoxicity in Mice.

Aim: Interleukin (IL)-37 is a new anti-inflammatory cytokine of the IL-1 family. This study aimed to determine the effects of IL-37 on acetaminophen (APAP)-induced liver injury. Materials and Methods: IL-37 plasmids were injected into mice via a tail vein hydrodynamics-based gene delivery. Results: Our results showed that IL-37 pretreatment significantly decreased serum alanine aminotransferase and aspartate aminotransferase levels, hepatic myeloperoxidase activity, and attenuated the histological liver damage. Compared to the APAP group, IL-37 administration decreased Kupffer cells numbers in the liver of APAP-induced hepatotoxicity in mice. Furthermore, IL-37 pretreatment reduced the expression of proinflammatory cytokines including tumor necrosis factor-α, IL-6, IL-17, and nuclear factor-κB (NF-κB) in APAP-induced mice. Conclusion: These results demonstrate that delivery of IL-37 plasmid can ameliorate APAP-induced liver injury by reducing proinflammatory cytokines production and preventing the activation of the NF-κB signaling pathway. IL-37 may be a promising candidate against APAP-induced liver injury.

Interleukin-39 exacerbates concanavalin A-induced liver injury.

BACKGROUND: Interleukin (IL)-39 is a novel member of IL-12 family and has been reported to play a pro-inflammatory role in lupus-like mice, but its function in concanavalin A (ConA)-induced liver injury is currently unclear. MATERIALS AND METHODS: In this study, we investigated the effects of IL-39 expression in a mouse model of ConA induced-hepatitis. We first showed that delivery of plasmid DNA encoding mouse IL-39 using the hydrodynamic tail vein injection method increased IL-39 mRNA and protein levels in the liver. We then administrated mice with IL-39 plasmid before ConA injection and measured serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, inflammatory infiltration, and hepatocyte necrosis in the liver. Additionally, we further explored the potential mechanism of IL-39 in ConA-induced liver injury by measuring several inflammatory mediators. RESULTS: We found that ectopic IL-39 expression promoted the ConA-induced increase in serum ALT and AST levels, inflammatory infiltration, and hepatocyte necrosis in the liver. We also observed that IL-39 plasmid administration significantly increased serum and liver interferon-γ, tumor necrosis factor-α, and IL-17A levels, but did not affect serum and liver IL-10 levels in ConA-induced hepatitis. CONCLUSION: Our results suggest that IL-39 can exacerbate ConA-induced hepatitis and may be a therapeutic target in inflammatory liver disease.

Protective effect of interleukin-36 receptor antagonist on liver injury induced by concanavalin A in mice.

OBJECTIVES: Interleukin-36 receptor antagonist (IL-36Ra) is a new member of the IL-1 family that exhibits anti-inflammatory activity in a variety of inflammatory and immune diseases. Our purpose was to determine the effect of IL-36Ra on liver injury in a mouse hepatitis model induced by concanavalin A (ConA). MATERIALS AND METHODS: Mice were treated with IL-36Ra DNA or pcDNA3.1 control plasmid using a hydrodynamic gene delivery approach. RESULTS: Our data reveal that treatment with IL-36Ra decreased liver inflammation and serum level of aminotransferases. Furthermore, IL-36Ra reduced ConA-induced pro-inflammatory cytokines (interferon-γ, tumor necrosis factor-α, and IL-17A) production when compared to control plasmid. CONCLUSION: Our results demonstrated that IL-36Ra is a critical protector against ConA-induced liver injury.

Interleukin-35 expression protects against cigarette smoke-induced lung inflammation in mice.

Cigarette smoke (CS) is a very important cause of pulmonary inflammatory diseases. Interleukin (IL)-35 is a novel anti-inflammatory cytokine but its role in CS-mediated lung inflammation remains unclear. In the present study, we examined the effect of IL-35 expression on CS-induced lung inflammation in mice. A plasmid DNA expressing IL-35 was injected into mice via a hydrodynamic-based gene delivery that were subsequently exposed to CS three times a day for 5 days. We found that IL-35 expression inhibited pulmonary inflammatory infiltration, lung tissue lesions, mucus secretion, and myeloperoxidase activity in CS-treated mice. Moreover, IL-35 expression decreased the production of IL-1ß, tumor necrosis factor-α, IL-6, and IL-17, but increased the level of IL-10 in bronchoalveolar lavage fluids and lung tissues from CS-challenged mice. These results suggest that in vivo expression of IL-35 can protect against CS-induced lung inflammation and may be a therapeutic target in CS-related pulmonary diseases.

IL-38 alleviates concanavalin A-induced liver injury in mice.

Interleukin (IL)-38 is a poorly characterized cytokine of the IL-1 family with anti-inflammatory activity. The role of IL-38 in liver injury remains unknown. We have investigated the potential effect of hydrodynamic-based gene delivery to express human IL-38 in mice with concanavalin A (Con A)-induced liver injury. Transfer of plasmid DNA encoding IL-38 significantly reduced hepatic toxicity and serum levels of aspartate aminotransferase and alanine aminotransferase compared with administration of a control plasmid. Moreover, IL-38 expression dramatically reduced serum levels of several pro-inflammatory cytokines, such as tumor necrosis factor-α, interferon-γ, IL-6, IL-17, and IL-22, but not levels of the anti-inflammatory cytokine IL-10. These results suggest that in vivo expression of human IL-38 in mice has hepatoprotective effects against Con A-induced liver injury by inhibition of inflammatory cytokine production.

Lentivirus expressing soluble ST2 alleviates bleomycin-induced pulmonary fibrosis in mice.

It has been shown that the expression of ST2, a receptor of interleukin (IL)-33, is elevated in the lungs of idiopathic pulmonary fibrosis patients and bleomycin-induced mouse models, however its contribution to the development of pulmonary fibrosis has yet to be tested. In the present study, we treated mice by intranasal instillation of lentivirus expressing soluble ST2 and evaluated lung inflammation and fibrosis in the bleomycin-induced pulmonary fibrosis mouse model. We found that ST2 lentivirus treatment significantly improved survival rate and reduced weight loss compared with controls treated with empty lentivirus. Furthermore, ST2 treatment profoundly attenuated the pulmonary inflammatory cell infiltration and fibrotic changes. Finally, ST2 treatment markedly lowered the levels of IL-4, IL-6, IL-13, IL-33, monocyte chemoattractant protein-1, and transforming growth factor-ß1, whereas it increased the levels of interferon-γ in bronchoalveolar lavage fluid. The results indicate that ST2 might prevent bleomycin-induced pulmonary fibrosis possibly through downregulating proinflammatory and profibrotic mediators. This study suggests that lentivirus expressing soluble ST2 might represent an effective therapeutic approach in the treatment of pulmonary fibrotic diseases.

Adenovirus-mediated interleukin-35 gene transfer suppresses allergic airway inflammation in a murine model of asthma.

OBJECTIVE AND DESIGN: Asthma is thought to result from the generation of T helper type 2 (Th2) responses, leading to bronchial inflammation. Interleukin (IL)-35 is a recently described member of IL-12 cytokine family that plays a critical role in influencing Th cell differentiation and inflammatory processes. The aim of this study was to examine the effect of adenovirus expressing IL-35 (AdIL-35) on allergic airway hyperresponsiveness (AHR) and inflammation in a mouse model of asthma. METHODS: BALB/c mice were subjected to an established model of allergic airway disease. AdIL-35 was administered intranasally and the effect of IL-35 on Th2 responses, pulmonary inflammation, goblet cell metaplasia, and AHR were assessed. RESULTS: Transfer of AdIL-35 significantly reduced the severity of AHR and numbers of inflammatory cells and levels of IL-4, IL-5, IL-13, and IL-17 in bronchoalveolar lavage fluid, compared with administration of a control virus. Moreover, AdIL-35 elevated the numbers of CD4+CD25+Foxp3+ regulatory T cells in the lungs. Histological analysis showed that AdIL-35 inhibited allergic lung tissue inflammation and mucus hypersecretion. CONCLUSION: These results demonstrate that adenovirus-mediated delivery of interleukin-35 gene can mitigate allergic airway inflammation in experimental asthma and suggest that IL-35 may offer a novel therapeutic approach to treat allergic asthma.

High-level expression and one-step purification of a soluble recombinant human interleukin-37b in Escherichia coli.

Interleukin (IL)-37 is a novel member of the IL-1 cytokine family. However, as a result of lacking efficient method to generate relatively large quantity of IL-37, little is known of its functions in man. In the present study, the recombinant human IL-37b containing a C-hexahistidine tag was expressed in Escherichia coli (E. coli). The expression level of IL-37b in E. coli was very high after induction with IPTG. Furthermore, IL-37b protein was largely found in the soluble fraction. The expressed protein was readily purified by one-step immobilized metal-ion affinity chromatography using Ni(2+)-nitrilotriacetic acid agarose. The purified IL-37b appeared as a single band on SDS-PAGE and the purity was more than 97%. The yield was 90mg IL-37b from 1l of bacterial culture. Western blotting and N-terminal sequencing confirmed the identity of the purified protein. The purified IL-37b inhibited significantly the release of tumor necrosis factor-α and IL-1ß in lipopolysaccharide-activated THP-1 cells. Thus, this method provides an efficient way to obtain an active IL-37 with high yield and high purity.