Activation of cannabinoid receptor CB2 regulates LPS-induced pro-inflammatory cytokine production and osteoclastogenic gene expression in human periodontal ligament cells

Background and Objective: It has been found that human periodontal ligament (hPDL) cells express cannabinoid receptor CB2. However, the functional importance of CB2 in hPDL cells exposed to bacterial endotoxins is not known. Here we investigate if the inflammation promoter lipopolysaccharide (LPS) affects CB2 expression and if activation of CB2 regulates LPS-induced pro-inflammatory cytokine production and osteoclastogenic gene expression in hPDL cells. Methods: The hPDL cells were obtained from extracted teeth of periodontally healthy subjects. CB2 expression in hPDL cells exposed to LPS was deter- mined by quantitative real-time PCR analysis. Then, the cells were incubated with or without CB2-specific agonist HU-308 before further stimulation with LPS. In some experiments, the cells were pre-treated with CB2-specific antagonist SR144528. The production of pro-inflammatory cytokines interleukin-1 beta (IL- 1β), interleukin-6 (IL-6) and tumor necrosis factoralpha (TNF-α) was assessed by enzyme-linked immunosorbent assay (ELISA). The mRNA expression of osteoclastogenic genes osteoprotegerin (OPG) and receptor activator of NF-κB ligand (RANKL) was examined using quantitative real-time PCR analysis. Results: CB2 expression in hPDL cells was markedly enhanced by LPS. HU-308 significantly suppressed the production of IL-1β, IL-6 and TNF-α exposed to LPS, whereas SR144528 attenuated this effect. The OPG/RANKL ratio decreased when exposed to LPS, furthermore increased significantly with the addition of HU-308 and finally decreased markedly after pretreatment with SR144528. Conclusion: Our study demonstrated that activation of CB2 had anti-inflammatory and anti-resorptive effects on LPS-stimulated hPDL cells. These findings suggest that activation of CB2 might be an effective therapeutic strategy for the treatment of inflammation and alveolar bone resorption in periodontitis.

IL-31与特应性皮炎的相关性研究进展

白细胞介素31（interleukin31,IL-31）是一种新近发现的细胞因子,属于IL-6家族,主要表达于激活的Th2细胞,其功能受体为IL-31受体与制瘤素M受体（oncostatin M receptor,OSMR）结合组成的异源二聚体复合物。研究发现,过度表达IL-31的转基因小鼠都会出现严重的瘙痒、脱毛以及皮肤炎性细胞浸润,类似于人类特应性皮炎（atopic dermatitis,AD）患者的病理学、血清学改变;同时还发现,IL-31与特应性皮炎患者的表皮淋巴细胞抗原阳性（CLA＋）皮肤归巢T细胞有关,

P2X7r antagonist suppressed hepatic stellate cells activation through NLPR3 inflammasome signaling

P2X7 receptor （P2X7r） is important in inflammation and fibrosis. The aim of the present study was to investigate the effect of P2X7r inhibition, using a specific inhibitor （A438079） to prevent the development of liver fibrosis on human hepatic stellate cells, LX-2. The supernatant from lipopolysaccharide （LPS）-stimulated RAW 264.7 mouse macrophages was supplemented to LX-2 cells for 24 h. LX-2 cells were primed with LPS for 4 h and subsequently stimulated for 30 rain with 3 mmol · L^-1 of adenosine 5＇-triphosphate （ATP）. A438079 （ 10 μmol · L^-1） was supplemented to LX-2 cells 10 rain prior to ATP. Directly treated with LPS on LX-2 cells, mRNA ex- pressions of IL-1β, IL-18 and IL-6 were increased, as well as P2X7r. And caspase-1, ASC and NLRP3 mRNA ex- pressions were increased with LPS stimulation. LPS stimulation also increased oL-SMA and collagen I mRNA expres- sions. Interestingly treatment of LX-2 cells with mediums from LPS-primed RAW 264.7 mouse macrophages exhibi- ted greater increase of mRNA expressions of above genes than those in LX-2 directly treated with LPS. Pretreatment of directly or indirectly LPS-stimulated LX-2 cells with A438079 both suppressed IL-1β mRNA expression. In addi- tion treatment of LPS-primed LX-2 cells with 3 mM ATP induced the significant increase of IL-1β, IL-6, caspase- 1, pannexin-1, α-SMA and collagen I mRNA expression, the increasing of oL-SMA protein expression and cleavage of IL-1β. These events were significantly suppressed by pretreatment with P2X7r antagonist A438079. P2XTr blockade also significantly reduced the protein expression of oL-SMA. Our results suggest that the involvement of the P2X7r-NLRP3 inflammasome pathway in the secretion of IL-1β from extracellular ATP/LPS-stimulated human he- patic stellate cells. This study demonstrated that repression of the P2XTr represents a novel potential therapeutic ap- proach to control liver fibrosis.

Effect of docosahexaenoic acid on interleukin-2 receptor signaling pathway in lipid rafts

Recent studies have shown that polyunsaturated fatty acids (PUFA) regulated the func-tions of membrane receptors in T cells and suppressed T cell -mediated immune responses. But the molecular mechanisms of immune regulation are not yet elucidated. Lipid rafts are plasma membrane microdomains, in which many receptors localized. The purpose of this study was to investigate the effect of DHA on IL-2R signaling pathway in lipid rafts. We isolated lipid rafts by discontinuous sucrose density gradient ultracentrifugation, and found that DHA could change the composition of lipid rafts and alter the distribution of key molecules of IL-2R signaling pathway, which transferred from lipid rafts to detergent-soluble membrane fractions. These results revealed that DHA treatment increased the proportion of polyunsaturated fatty acids especially n?3 polyunsaturated fatty acids in lipid rafts and changed the lipid environment of membrane microdomains in T cells. Compared with controls, DHA changed the localization of IL-2R, STAT5a and STAT5b in lipid rafts and suppressed the expression of JAK1, JAK3 and tyrosine phosphotyrosine in soluble membrane fractions. Summarily, this study con-cluded the effects of DHA on IL-2R signaling pathway in lipid rafts and explained the regulation of PUFAs in T cell-mediated immune responses.

Promising xenograft animal model recapitulating the features of human pancreatic cancer

BACKGROUND Multiple sites of metastasis and desmoplastic reactions in the stroma are key features of human pancreatic cancer(PC).There are currently no simple and reliable animal models that can mimic these features for accurate disease modeling.AIM To create a new xenograft animal model that can faithfully recapitulate the features of human PC.METHODS Interleukin 2 receptor subunit gamma(IL2RG)gene knockout Syrian hamster was created and characterized.A panel of human PC cell lines were transplanted into IL2RG knockout Syrian hamsters and severe immune-deficient mice subcutaneously or orthotopically.Tumor growth,local invasion,remote organ metastasis,histopathology,and molecular alterations of tumor cells and stroma were compared over time.RESULTS The Syrian hamster with IL2RG gene knockout(named ZZU001)demonstrated an immune-deficient phenotype and function.ZZU001 hamsters faithfully recapitulated most features of human PC,in particular,they developed metastasis at multiple sites.PC tissues derived from ZZU001 hamsters displayed desmoplastic reactions in the stroma and epithelial to mesenchymal transition phenotypes,whereas PC tissues derived from immune-deficient mice did not present such features.CONCLUSION ZZU001 hamsters engrafted with human PC cells are a superior animal model compared to immune-deficient mice.ZZU001 hamsters can be a valuable animal model for better understanding the molecular mechanism of tumorigenesis and metastasis and the evaluation of new drugs targeting human PC.

The IL13α 2R paves the way for anti-glioma nanotherapy

Glioblastoma(GBM)is one of the most aggressive(grade IV)gliomas characterized by a high rate of recurrence,resistance to therapy and a grim survival prognosis.The long-awaited improvement in GBM patients'survival rates essentially depends on advances in the development of new therapeutic approaches.Recent preclinical studies show that nanoscale materials could greatly contribute to the improvement of diagnosis and management of brain cancers.In the current review,we will discuss how specific features of glioma pathobiology can be employed for designing efficient targeting approaches.Moreover,we willsummarize the main evidence for the potential of the IL-13R alpha 2 receptor(IL13α2R)targeting in GBM early diagnosis and experimental therapy.

Signal for IL-2 internalization located in the endocellular domain of IL-2R γsubunit only

Interleukin-2(IL-2) is an important immunoregulatory factor. After the interaction between IL-2 and its receptor, intracellular signal molecules were activated and pro-oncogenes, e.g. c-Myc, c-Fos, c-Jun and Bcl-2 were induced, then cells stimulated with IL-2 would proliferate or differentiate. During these processes, IL-2 were internalized. The internalization of IL-2 mediated by IL-2R decreases the number of IL-2R on cell membranes, and makes extracellular IL-2 enter cells and degrade. It will down-regulate IL-2 biological activities. In order to identify the IL-2R subunit responsible for IL-2 internalization, chimeric IL-2Rs which consisted of different endocellular domains and extracellular domains from various IL-2R subunits were constructed. After they were transfected into L929 cell line, the IL-2 internalization was detected. Results showed that intracellular domains from IL-2R α and β subunits could not mediate IL-2 internalization alone; the signal for IL-2 internalization was located only in the endocellular domain of IL-2R γ subunit. Furthermore, IL-2 internalization extent would be affected by affinity between IL-2 and IL-2R.

PAFR/Stat3 axis maintains the symbiotic ecosystem between tumor and stroma to facilitate tumor malignancy

Stroma surrounding the tumor cells plays crucial roles for tumor progression.However,little is known about the factors that maintain the symbiosis between stroma and tumor cells.In this study,we found that the transcriptional regulator-signal transducer and activator of transcription 3(Stat3)was frequently activated in cancer-associated fibroblasts(CAFs),which was a potent facilitator of tumor malignancy,and formed forward feedback loop with platelet-activating factor receptor(PAFR)both in CAFs and tumor cells.Importantly,PAFR/Stat3 axis connected intercellular signaling crosstalk between CAFs and cancer cells and drove mutual transcriptional programming of these two types of cells.Two central Stat3-related cytokine signaling molecules-interleukin 6(IL-6)and IL-11 played the critical role in the process of PAFR/Stat3 axis-mediated communication between tumor and CAFs.Pharmacological inhibition of PAFR and Stat3 activities effectively reduced tumor progression using CAFs/tumor co-culture xenograft model.Our study reveals that PAFR/Stat3 axis enhances the interaction between tumor and its associated stroma and suggests that targeting this axis can be an effective therapeutic strategy against tumor malignancy.

白细胞介素4受体Q576R基因多态性与支气管哮喘的相关性

目的 探讨白细胞介素4受体(inlerleukin- 4 receptor,IL- 4 R)基因Q5 76 R多态性与儿童支气管哮喘的相关性。方法 用聚合酶链反应-限制性片段长度多态性分析方法检测94例哮喘儿童和6 8名正常对照儿童IL - 4 R Q5 76 R的多态性,并进行χ2 检验。结果 IL - 4 R杂合突变基因型Q5 76 R、突变等位基因R5 76的分布频率在哮喘儿童及正常对照儿童中差异有统计学意义(P<0 .0 5 )。结论 IL - 4 R突变等位基因R5 76可能是儿童易感哮喘的一个候选基因。