支气管平滑肌细胞中MK2 和MK3 过表达对细胞因子分泌的调节作用

目的:研究支气管平滑肌细胞中丝裂原活化蛋白激酶2/3(MK2/3)的过表达对细胞因子分泌的调节作用。方法:将野生型MK2和MK3腺病毒转染至人支气管平滑肌细胞中,Western blot实验检测MK2和MK3蛋白表达水平,确定转染腺病毒的最佳感染系数,检测热休克蛋白HSP27的磷酸化水平以及MK2和MK3过表达对MAPK和核因子(NF)-κB信号通路的影响。ELISA检测支气管平滑肌细胞分泌细胞因子的情况。结果:野生型MK2和MK3腺病毒转染至支气管平滑肌细胞的最佳感染系数为40,在支气管平滑肌细胞内有活性。MK2通过p38MAPK信号通路促进IL-6的分泌,抑制正常T细胞表达及趋化因子配体5(CCL5)的分泌,MK3通过NF-κB信号通路抑制RANTES/CCL5的分泌。结论:本研究揭示了MK2和MK3在支气管平滑肌细胞中通过不同的信号通路调节细胞因子的分泌,通过靶向MKs可调节支气管气道炎症反应。     

高脂饮食上调兔子血管内膜与血清炎性因子表达

目的:分析高脂饮食致肥胖或动脉粥样硬化兔子血管内膜白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)水平变化。方法:12只健康新西兰大白兔,分为普通饮食组(OD组)和高脂饮食组(HFD组)。依据动脉粥样硬化造模方法,高脂饮食喂养兔8周后,获取兔子血液或颈动脉组织。检测血细胞相关参数和血液生化参数及动脉内膜的厚度,同时用ELISA检测IL-1β和TNF-α水平,Western Blot法检测血管内膜IL-1β和TNF-α蛋白的表达。比较分析两组各检测参数的差异。结果:两组兔子外周血细胞检测项目无统计学差异(P>0.05)。HFD组脂质检测指标甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)和载脂蛋白B(ApoB)均显著高于OD组(P<0.05,P<0.01),而高密度脂蛋白胆固醇(HDL-C)则显著低于OD组(P<0.05)。其它血液生化项目在两组间的水平无显著差异(P>0.05)。ELISA检测OD组血浆IL-1β和TNF-α的水平显著低于HFD组(P<0.05)。以高脂饮食喂养健康兔子发现HFD组兔血管内膜的厚度明显高于OD组(P<0.05),且血管内膜炎性因子IL-1β和TNF-α蛋白表达具有同样的趋势。结论:以高脂饮食喂养健康兔子发现动脉粥样硬化模型兔子炎性因子IL-1β和TNF-α在血液中和血管内膜均有表达增高,或可与动脉粥样硬化相关。     

The Importance of Early Recognition,Timely Management,and the Role of Healthcare Providers in Multisystem Inflammatory Syndrome in Children

In April 2020, a pediatric report of an unusual inflammatory illness associated with coronavirus disease 2019 (COVID-19) led to similar cases in Europe and North America, which was referred to as multisystem inflammatory syndrome in children (MIS-C). Herein, we describe the case of a 12-year-old boy who had a history of polymerase chain reaction-confirmed COVID-19 and developed MIS-C approximately three weeks after an initial diagnosis of COVID-19. High fever with abdominal pain mimicking appendicitis was the initial manifestation of MIS-C, which could have been easily missed if the patient''s history of COVID-19 was ignored. Intravenous immunoglobulin was administered twice, 24 hours apart, five days after the onset of MIS-C, and the patient fully recovered without any obvious sequelae. Early recognition by disease awareness and prompt management are the keys to saving the lives of children affected by MIS-C.     

Activation of apoptosis by Salmonella pathogenicity island-1 effectors through both intrinsic and extrinsic pathways in Salmonella-infected macrophages

BackgroundSalmonella enterica serovar Typhimurium, a non-typhoidal food-borne pathogen, causes acute enterocolitis, bacteremia, extraintestinal focal infections in humans. Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2) contribute to invading into host cellular cytosol, residing in Salmonella-containing vacuoles for intracellular survival, and inducing cellular apoptosis. This study aimed to better understand the mechanism underlying apoptosis in Salmonella-infected macrophages.MethodsS. Typhimurium SL1344 was used to evaluate extrinsic and intrinsic apoptosis pathways in THP-1 monocyte-derived macrophages in response to Salmonella infection.ResultsActivated caspase-3-induced apoptosis pathways, including extrinsic (caspase-8-mediated) and intrinsic (caspase-9-mediated) pathways, in Salmonella-infected macrophages were verified. THP-1 cells with dysfunction of TLR-4 and TLR-5 and Salmonella SPI-1 and SPI-2 mutants were constructed to identify the roles of the genes associated with programmed cell death in the macrophages. Caspase-3 activation in THP-1 macrophages was induced by Salmonella through TLR-4 and TLR-5 signaling pathways. We also identified that SPI-1 structure protein PrgH and effectors SipB and SipD, but not SPI-2 structure protein SsaV, could induce apoptosis via caspase-3 activation and reduce the secretion of inflammation marker TNF-α in the Salmonella-infected cells. The two effectors also reduced the translocation of the p65 subunit of NF-κB into the nucleus and the expression of TNF-α, and then inflammation was diminished.ConclusionNon-typhoid Salmonella induced apoptosis of macrophages and thereby reduced inflammatory cytokine production through the expression of SPI-1. This mechanism in host–pathogen interaction may explain why Salmonella usually manifests as occult bacteremia with less systemic inflammatory response syndrome in the bloodstream infection of children.     

Primary gastrointestinal T-cell lymphomas: concepts and diagnostic insights

The gastrointestinal tract represents the most common site of extranodal non-Hodgkin lymphoma. Malignant lymphomas represent up to 4% of all malignant neoplasms of the GI tract. Overall, lymphomas of B-cell lineage predominate. T-cell lymphomas are uncommon and account for 6% of all GI tract lymphomas. Intestinal T-cell lymphomas comprise a heterogeneous group of lymphoproliferative neoplasms with distinct morphologic, immunophenotypic, and genetic features. Based on the recently revised 2017 WHO classification, intestinal T-cell lymphomas are categorized into four distinct entities: Enteropathy-associated T-cell lymphoma (EATL), monomorphic epitheliotropic intestinal T-cell lymphoma (METL), intestinal T-cell lymphoma, not otherwise specified (ITCL, NOS) and indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. Herein, we aim to create awareness of these uncommon neoplasms with emphasis on key diagnostic points.     

Studying host genetic background effects on multimorbidity of intestinal cancer development,type 2 diabetes and obesity in response to oral bacterial infection and high‐fat diet using the collaborative cross (CC) lines

BackgroundMultimorbidity of intestinal cancer (IC), type 2 diabetes (T2D) and obesity is a complex set of diseases, affected by environmental and genetic risk factors. High‐fat diet (HFD) and oral bacterial infection play important roles in the etiology of these diseases through inflammation and various biological mechanisms.MethodsTo study the complexity of this multimorbidity, we used the collaborative cross (CC) mouse genetics reference population. We aimed to study the multimorbidity of IC, T2D, and obesity using CC lines, measuring their responses to HFD and oral bacterial infection. The study used 63 mice of both sexes generated from two CC lines (IL557 and IL711). For 12 weeks, experimental mice were maintained on specific dietary regimes combined with co‐infection with oral bacteria Porphyromonas gingivalis and Fusobacterium nucleatum, while control groups were not infected. Body weight (BW) and results of a intraperitoneal glucose tolerance test (IPGTT) were recorded at the end of 12 weeks, after which length and size of the intestines were assessed for polyp counts.ResultsPolyp counts ranged between 2 and 10 per CC line. The combination of HFD and infection significantly reduced (P < .01) the colon polyp size of IL557 females to 2.5 cm², compared to the other groups. Comparing BW gain, IL557 males on HFD gained 18 g, while the females gained 10 g under the same conditions and showed the highest area under curve (AUC) values of 40 000‐45 000 (min mg/dL) in the IPGTT.ConclusionThe results show that mice from different genetic backgrounds respond differently to a high fat diet and oral infection in terms of polyp development and glucose tolerance, and this effect is gender related.     

豚鼠胆囊胆固醇结石形成过程中肠道传输功能下降的细胞及分子机制探讨

目的探讨豚鼠胆囊胆固醇结石形成过程中肠道传输功能下降的细胞和分子机制及其与胆石形成的关系。方法健康雄性豚鼠40只,4周龄,体质量120～125g。将其随机分为实验组与对照组,每组20只。实验组给予致石饲料（胆固醇含量2%）,对照组给予正常颗粒饲料。8周造模结束后,用逆转录聚合酶链反应（RT-PCR）检测小肠组织中c-kit及scf的mRNA的表达情况,利用末端回肠全层铺片免疫荧光化学染色及激光共聚焦显微镜观察各组Cajal样间质细胞（ICCs）数量的变化。结果 RT-PCR结果显示,与对照组相比,实验组豚鼠小肠c-kit（0.316±0.056vs0.912±0.103;t=6.582,P〈0.01）和scf（0.499±0.012 vs 0.899±0.124;t=6.163,P〈0.01）的mRNA水平的表达量下降;对照组豚鼠回肠ICCs平均阳性面积为（56.24±2.68）%,实验组为（22.26±1.14）%,较对照组明显降低（t=15.256,P〈0.01）。结论饮食诱导的豚鼠胆囊胆固醇结石形成过程中,小肠c-kit和scf基因mRNA表达水平下降,ICCs数量明显减少。c-kit/scf通路抑制可能参与胆囊胆固醇结石的形成过程中肠道传输功能下降的发生。     

支气管哮喘患儿诱导痰中炎性细胞类型及炎症相关细胞因子的临床价值研究

目的探讨支气管哮喘患儿诱导痰中炎性细胞类型及炎症相关细胞因子的临床价值。方法选取支气管哮喘患儿54例(研究组)作为研究对象,根据哮喘发作期严重程度将研究组分为轻度哮喘组、中度哮喘组和重度哮喘组。另选取性别和年龄相当的支气管肺炎(不合并哮喘)患儿42例作为对照组,检测对照组和研究组治疗前、后诱导痰中炎性细胞类型、T淋巴细胞免疫球蛋白黏蛋白-3(Tim-3)mRNA,以及白细胞介素(IL)-2、IL-4、IL-10、IL-13、干扰素-γ(IFN-γ)等炎症相关细胞因子水平,分析诱导痰中炎症细胞类型以及炎症相关细胞因子在儿童支气管哮喘临床诊断中的价值。结果治疗前,研究组诱导痰中嗜酸性粒细胞百分比、淋巴细胞百分比、Tim-3 mRNA、IL-4、IL-13、IFN-γ及IFN-γ/IL-10水平均高于对照组,差异有统计学意义(P<0.05);IL-2、IL-10及辅助性T细胞(Th)1/Th2水平均低于对照组,差异有统计学意义(P<0.05)。中度哮喘组和重度哮喘组患儿嗜酸性粒细胞百分比、中性粒细胞百分比、淋巴细胞百分比、Tim-3 mRNA、IL-4、IL-13、IFN-γ及IFN-γ/IL-10水平高于轻度哮喘组、对照组患儿,差异有统计学意义(P<0.05);IL-2、IL-10及Th1/Th2低于轻度哮喘组、对照组患儿,差异有统计学意义(P<0.05)。Logistic回归分析结果显示,嗜酸性粒细胞比例、Tim-3 mRNA、IFN-γ、IL-10、IFN-γ/IL-10及Th1/Th2为儿童支气管哮喘的独立影响因素。受试者工作特征(ROC)曲线分析结果显示,嗜酸性粒细胞百分比、Tim-3 mRNA、IFN-γ、IFN-γ/IL-10及Th1/Th2对儿童支气管哮喘及支气管肺炎(不合并哮喘)具有一定的鉴别作用。结论支气管哮喘患儿诱导痰中嗜酸性粒细胞百分比、Tim-3 mRNA、IFN-γ、IFN-γ/IL-10及Th1/Th2的表达异常有助于疾病的病情监测、疗效评估以及与儿童支气管肺炎(不合并哮喘)的鉴别诊断。