IL-6 induces hepatic inflammation and collagen synthesis in vivo.

IL-6 regulates the synthesis of a broad spectrum of acute phase proteins in the liver. Also, it is involved in the pathogenesis of many fibrogenic diseases. To study the inflammatory effects of IL-6 on the liver in vivo, human rIL-6, produced in Escherichia coli, was injected intraperitoneally into rats (25 micrograms/100 g body weight). The major fraction of injected IL-6 was accumulated in the liver within 40 min, and the number of platelets was increased during 72 h after injection. After 5 weeks of injection, the levels of serum glutamine pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) were not changed, but they were significantly elevated at 13 weeks of treatment. Meanwhile, serum albumin levels were slightly decreased compared with those of controls. The same phenomena were observed in carbon tetrachloride-treated rats. Collagen synthesis was increased in the liver tissues and in the culture supernatants of hepatic lipocytes isolated from the rats treated with IL-6 for 13 weeks. Histological analysis correlated well with biochemical analysis. At 5 weeks of treatment, only mild pathological changes were observed, but severe hepatocyte necrosis and the accumulation of fibres in necrotic area were developed in the liver of IL-6-treated rats after 13 weeks of treatment, confirming that hepatic inflammation and fibrosis were developed. IL-6 activities in the sera and in the culture supernatants of lipocytes from IL-6-treated rats were elevated compared with those in controls. These biochemical and pathological data indicate that IL-6 can induce hepatic inflammation, and it has important roles in the pathogenesis of fibrosis and diseases of the liver in vivo. In addition, these results will provide useful information for the clinical trials of IL-6.     

Psoriatic inflammation causes hepatic inflammation with concomitant dysregulation in hepatic metabolism via IL-17A/IL-17 receptor signaling in a murine model

Psoriatic inflammation has been shown to be associated with cardiovascular dysfunction and systemic inflammation. Recently, psoriasis has also been linked to hepatic disorders, however underlying mechanism connecting the two are unknown. IL-17A being a central pro-inflammatory cytokine in the pathogenesis of psoriasis may be involved in hepatic inflammation through its receptor and downward signaling; however so far no study has investigated IL-17A related signaling in the liver during psoriasis in a murine model. Therefore, this study explored psoriasis-induced hepatic inflammation and concurrent metabolic changes. Mice were applied topically imiquimod (IMQ) to develop psoriatic inflammation. Additionally mice were also treated either with IL-17A or anti-IL17A antibody to explore the role of IL-17 related signaling in liver. Mice were then assessed for hepatic inflammation through assessment of inflammatory/oxidative stress markers (IL-17RC, NFκB, IL-6, MCP-1, IL-1β, GM-CSF, ICAM-1, iNOS, lipid peroxides and myeloperoxidase activity) as well as hepatic injury (alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase) and protein/lipid metabolic biomarkers (total proteins, albumin, total bilirubin, triglycerides, HDL cholesterol, and total cholesterol). IMQ treatment led to hepatic inflammation as evidenced by increased pro-inflammatory cytokines and oxidative stress with concomitant dysregulation in hepatic protein/lipid metabolism. Treatment with IL-17A further aggravated, whereas treatment with anti-IL17A antibody ameliorated IMQ-induced changes in hepatic injury/inflammation and protein/lipid metabolism. Our study shows for the first time that psoriatic inflammation leads to hepatic inflammation which results in dysregulated protein/lipid metabolism through IL-17RC/NFκB signaling. This could result in increased risk of cardiovascular dysfunction in patients with psoriasis.     

IL-6 and soluble IL-6 receptors (sIL-6R and sgp130) in human pleural effusions: massive IL-6 production independently of underlying diseases

IL-6, soluble IL-6 receptor (sIL-6R) and soluble gp130 (sgp130) levels were measured in sera and pleural effusions from 42 patients with metastatic carcinoma, non-Hodgkin's lymphoma, tuberculosis, cardiac failure and miscellaneous diseases. Pleural IL-6 levels measured by ELISA were very high in all patient groups (mean 34.8 ± 15.3 ng/ml) without significant difference according to diseases. IL-6 was shown to be biologically active in a proliferative assay. Serum IL-6 levels were low (0.049 ± 0.014 ng/ml) and did not correlate with pleural fluid levels. Pleural IL-6 levels correlated with the number of polymorphonuclear cells in pleural fluid (P< 0.03). Pleural sIL-6R levels (76 ± 8 ng/ml) were always lower than serum levels (196 ± 12 ng/ml; P< 0.0001) but correlated with them (P< 0.01). Pleural sIL-6R and albumin levels correlated (P< 0.01), suggesting a transudation of sIL-6R from the serum. Pleural sgp130 levels (10.9 ± 1.0 ng/ml) were lower than serum levels (24.6 ± 2.8 ng/ml; P< 0.002). After gel filtration of pleural fluid, the bulk of IL-6 (>90%) was recovered in a 15 000–30 000 fraction, corresponding to the expected mol. wt of free IL-6. These results suggest a production and a sequestration of IL-6 in the pleural cavity in all studied conditions.     

铁缺乏孕妇外周血单个核细胞IL-2、IL-6分泌水平研究

目的探讨铁缺乏及不同补铁浓度对孕妇外周血单个核细胞（PBMC）IL-2、IL-6分泌水平的影响,为临床补铁提供理论依据。方法孕妇血肝素抗凝,分离PBMC。给予LPS或PHA刺激后,用酶联免疫吸附法（ELISA）检测不同铁浓度环境下健康及铁缺乏孕妇PBMC的IL-2、IL-6分泌水平。结果体外试验表明：给予LPS或PHA刺激后,铁缺乏患者PBMC的IL-2分泌水平低于健康孕妇平均水平,IL-6高于健康孕妇平均水平;不同补铁浓度对IL-2分泌水平无影响,但IL-6分泌水平有所提高。结论孕期应该注重含铁食物的摄入,平衡膳食,预防因铁营养缺乏而导致的免疫功能下降;铁缺乏孕妇适量补铁有利于提高IL-6的分泌水平,促进机体造血功能的改善与恢复。     

小鼠白细胞介素6的cDNA克隆及其在昆虫细胞中的表达

本文采用ＲＴ－ＰＣＲ技术从ＬＰＳ刺激后的小鼠腹腔巨噬细胞，扩增小鼠ＩＬ－６ｃＤＮＡ，并克隆构建ｐＧＥＭ－３Ｚｆ（＋）ＩＬ－６质粒，继将小鼠所得ｃＤＮＡ克隆到ｐＶＬ１３９２载体上，利用杆状病毒ＡｃＮＰＶ表达系统在Ｓｆ９中进行瞬间表达，用ＩＬ－６依赖细胞株ＭＨ６０·ＢＳＦ２检测其表达活性，结果表明，感染后４８ｈ后就具有明显ＩＬ－６表达，由此可见，利用该系统可成功地表达小鼠ＩＬ－６基因。     

Injury,dysbiosis, and filaggrin deficiency drive skin inflammation through keratinocyte IL-1α release

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Subacute exposure to bisphenol F diglycidyl-ether induces chronic dermatitis characterized by psoriasis-like skin inflammation in mice

Bisphenol F diglycidyl ether (BFDGE) is widely used in the synthesis process of plastic products. While exposure to bisphenol A diglycidyl ether (BADGE), which has a similar structure to BFDGE and which is used for the same purpose, has been reported to cause health risks, there is still little information on BFDGE. Because it is estimated that the industrial workers are exposed to large amounts of BFDGE, the health risks associated with BFDGE exposure need to be clarified. We investigated the toxicity of cutaneous exposure to BFDGE using an in vitro evaluation system and a mouse exposure model. The tumorigenic potential of BFDGE was confirmed by the Bhas 42 cell transformation assay, which showed that BFDGE has both promoter and initiator activity, in vitro. A single dermal application of BFDGE was associated with minor contact hypersensitivity symptoms. In contrast, repeated dermal exposure to BFDGE for 2 weeks induced persistent acute inflammation with features similar to inflammation in human psoriasis. This is the first report evaluating the toxicity of BFDGE in animals, and we showed that BFDGE carries a health risk of inducing skin dermatitis similar to that in human psoriasis in an exposure period-dependent manner.     

Soluble interleukin-6 receptor is elevated during influenza A virus infection and mediates the IL-6 and IL-32 inflammatory cytokine burst

Influenza A virus (IAV) infection is a major worldwide public health problem. However, the factors involved in mediating the inflammatory response to this infection and their relationships remain poorly understood. Here, we show that IAV infection stimulates the expression of the soluble IL-6 receptor (sIL-6R), a multifunctional protein involved in IL-6 signaling. Interestingly, sIL-6R expression upregulated the levels of its own ligand, IL-6 and those of the pro-inflammatory cytokine IL-32. shRNA-mediated knockdown of sIL-6R suppressed IL-6 and IL-32, indicating that this regulation is dependent on sIL-6R during IAV infection. Furthermore, our results demonstrate that IL-32 participates in a negative feedback loop that inhibits sIL-6R while upregulating IL-6 expression during IAV infection. Therefore, we show that sIL-6R is a critical cellular factor involved in the acute inflammatory response to viral infection.     

Pathogenic function of IL-1 beta in psoriasiform skin lesions of flaky skin (fsn/fsn) mice

IL-1 acts on many cells as an inflammatory mediator. Its two forms, IL-1α and IL-1β, are regulated differentially within hyperproliferative inflammatory skin conditions, such as psoriasis. While IL-1α is down-regulated within psoriatic lesions, the levels of IL-1β are increased. However, some investigators have described an inactive form of IL-1β in psoriasis, while others have detected increased IL-1β activity within these lesions. Thus, its in vivo role remains unclear. We have assessed expression and function of IL-1β within psoriasiform skin lesions of the spontaneous mouse mutation flaky skin (fsn/fsn). It was found that IL-1β was increased by 357% within psoriasiform lesions of fsn/fsn mice compared with their wild-type or heterozygous (+/?) littermates (P < 0·00001). When the IL-1β function was inhibited by i.p. injection with a neutralizing MoAb, no effects were seen in +/? mice. In contrast, psoriasiform features in fsn/fsn mice were alleviated dramatically, as demonstrated by a 40% decrease of the epidermal thickness and a diminished number of intra-epidermal microabscesses. In addition, infiltrating epidermal CD4⁺ and CD8⁺ T cells were decreased by 68% and 81%, respectively (P < 0·05), and epidermal Langerhans cells also were reduced by 36% (P < 0·005). In contrast, mast cells were not affected, suggesting differential responses of various cutaneous cell types. Our results demonstrate an important in vivo role of IL-1β for the generation of hyperproliferative inflammatory skin lesions in the fsn/fsn model.     

Chronic mucocutaneous candidiasis. I. Altered antigen-stimulated IL-2, IL-4, IL-6 and interferon-gamma (IFN-γ) production

Patients with chronic mucocutaneous candidiasis (CMC) present with persistent infections with the opportunistic yeast Candida. Impaired cell-mediated responses to Candida have been documented in CMC patients, but the defect remains poorly understood. The importance of Th1 cytokines in resistance and Th2 in susceptibility to Candida infections has recently been demonstrated in murine models. In our studies we evaluated production of IL-2 and IFN-γ (markers of Th1 type responses) as well as IL-4 and IL-6 (Th2 type markers) following stimulation with two kinds of Candida antigens (CAgs), polysaccharide antigens, tetanus toxoid and pokeweed mitogen. Our results demonstrate that CMC patients have impaired cytokine production upon in vitro stimulation with CAgs resulting in low or absent IL-2, increased IL-6 and either absent or increased IFN-γ production. Cytokine production following stimulation by other antigens was unaltered. The overall cytokine-producing capacity assessed through mitogen stimulation was also intact. Addition of IFN-α or IFN-γ to culture in an attempt to modify cytokine production did not have significant effects. Levels of soluble IL-6 receptors were not increased and could not account for increased IL-6 production. Our studies support the hypothesis that Candida antigens trigger a predominantly Th2 instead of a Th1 cytokine response in patients with CMC.     

肝细胞特异性Sirt1缺失加重小鼠肝脏炎性反应

目的探究沉默信息调节因子1 (Sirt1)基因的缺失对小鼠肝脏炎性反应的影响及其作用机制。方法每周记录在高脂喂养下的野生型C57BL/6J雄性小鼠和肝脏特异性Sirt1敲除(Sirt1-LKO)雄性小鼠的体质量,用Western blot和q-PCR检测炎性因子的表达;给小鼠腹腔注射20 mg/kg LPS,用生存曲线来反映小鼠对炎性反应的敏感性。结果与对照组WT小鼠相比,Sirt1-LKO小鼠表现为体质量明显减轻(P<0.05)。另外,生存曲线KaplaneMeier图显示Sirt1-LKO小鼠对LPS刺激呈现低敏感性(P<0.05)。Sirt1-LKO小鼠原代肝细胞中NF-κB蛋白水平增高(P<0.05),及NF-κB下游靶基因炎性因子Tnfα和IL6明显上调(P<0.05)。结论肝细胞特异性Sirt1缺失加重肝脏炎性反应。     

Ovalicin attenuates atopic dermatitis symptoms by inhibiting IL-31 signaling and intracellular calcium influx

Atopic dermatitis (AD) is a common skin disorder difficult to be treated with medication. This study investigated the potential of ovalicin extracted from Cordyceps militaris for the treatment of AD using in vitro and in vivo models. We found that, in canine macrophage cell line DH82, lipopolysaccharide (LPS) upregulated the expression of genes associated with inflammation and pruritic responses through activating calcium and interleukin-31 (IL-31) signaling, and the upregulation could be suppressed by ovalicin, with an effect significantly stronger than dexamethasone. Ovalicin also reduced the expression of IL-31 downstream genes, including JAK2 (Janus kinase 2), TRPV1 (transient receptor potential vanilloid receptor-1), and HRH2 (histamine receptor H2). Ovalicin significantly alleviated the allergic symptoms in the AD mouse model. Histologically, the number of macrophages and mast cells infiltrated in the dermis was significantly reduced by ovalicin treatment. In the skin tissue of AD mice, reduction of IL-31 receptor was observed in the ovalicin treated group compared to the group without ovalicin treatment. To our knowledge, this is the first study to elucidate the anti-atopic mechanism of ovalicin, which could be an alternative to steroidal drugs commonly used for AD treatment.     

IL-25 in allergic inflammation

IL-25, also known as IL-17E, is a member of the IL-17 cytokine family mostly produced by epithelial cells and innate immune cells. After binding to the IL-17RB/IL-17RA complex, IL-25 induces downstream signaling responses in epithelial cells and type 2 lymphocytes, which initiates, propagates, and sustains type 2 immunity. The function of IL-25 in allergic diseases such as asthma has been well established, and now also is extended to diseases such as inflammatory bowel disease and cancer. This review summarizes the literature on IL-25 and discusses the unsolved questions. Our knowledge on IL-25 will pave the pathway for targeting this cytokine in inflammatory diseases.     

人IL-31基因克隆、表达及在皮肤炎症中的作用

目的 克隆人IL-31基因,构建原核表达载体,并诱导其在大肠杆菌中表达,研究hIL-31蛋白与皮肤炎症的关系.方法 采用RT-PCR克隆人IL-31基因,将其克隆到原核表达载体pET28a( ),并通过IPTG诱导目的基因在大肠杆菌中表达,用该目的蛋白刺激人表皮角质细胞HaCaT,RT-PCR检测趋化因子MIP-3β、TARC及TCA-3(I-309)mRNA的表达;小鼠皮内注射该目的蛋白,观察局部炎症表现,皮肤标本HE染色观察皮肤炎性特征,采血进行白细胞计数及分类,ELISA法检测血清IL-1βIL-6和TNF-α水平,流式细胞仪分析胸腺及脾脏T细胞亚群.结果 成功获得495bp的人IL-31基因,原核表达质粒构建正确,IPTG诱导目的基因在大肠杆菌中大量表达;该目的蛋白可刺激HaCaT表达趋化因子MIP-3β、TARC、I-309;小鼠皮肤注射部位有脱毛,HE染色可见炎性细胞浸润,外周血白细胞总数增加,中性粒细胞比例增高,血清IL-1β、IL-6和TNF-α水平增高,脾脏CD4 T细胞百分比增高,CD8 T细胞百分比减少.结论 人IL-31基因克隆及原核表达已获成功,hIL-31蛋白可刺激HaCaT细胞表达MIP-3β、TARC、I-309,诱导小鼠皮肤炎症反应.     

Role of IL-6 in spinal cord injury in a mouse model

In recent years, various studies have been conducted toward the goal of achieving regeneration of the central nervous system using neural stem cells. However, various complex factors are involved in the regulation of neural stem cell differentiation, and many unresolved questions remain. It has been reported that after spinal cord injury, the intrinsic neural stem cells do not differentiate into neurons but, rather, into astrocytes, resulting in the formation of glial scars. Based on reports that the expression of interleukin (IL)-6 and the IL-6 receptor (IL-6R) is sharply increased in the acute stages after spinal cord injury and that IL-6 may serve as a factor strongly inducing the differentiation of neural stem cells into astrocytes, we examined the effects of an antibody to IL-6R in cases of spinal cord injury and found that the antibody suppressed secondary injury (caused by inflammatory reactions) and glial scar formation, facilitating functional recovery. This article presents the data from this investigation and discusses the relationship between IL-6 signals and spinal cord injury.