Activation of Toll-like receptor 2 increases macrophage resistance to HIV-1 infection

Patients infected with HIV-1, the etiological agent of AIDS, have increased intestinal permeability, which allows for the passage of microbial products, including Toll-like receptor (TLR) ligands, into circulation. The exposure of HIV-1-infected cells to certain TLR agonists affects viral replication, but studies associating viral production with the activation of TLR2 in HIV-1-infected cells are rare and controversial. Here, we report that the TLR2 ligands Zymosan and Pam3CSK4 potently inhibit HIV-1 replication in acutely infected monocyte-derived macrophages and the exposure to TLR2 ligands prior to infection renders macrophages refractory to HIV-1 production. Macrophage treatment with Pam3CSK4 did not change the cellular expression of the HIV-1 entry receptors CD4 and CCR5. Both TLR2 ligands increased the macrophage production of β-chemokines and IL-10, and the blockage of these soluble factors prevented the inhibitory effect of TLR2 activation on HIV-1 replication. Our findings show that the direct engagement of TLR2 in HIV-1-infected macrophages increase cellular resistance to HIV-1 infection, and that controlling HIV-1 replication with agonists for TLR2 might have implications for the development of antiretroviral therapies.     

Sulglycotide ameliorates inflammation in lipopolysaccharide-stimulated mouse macrophage cells by blocking the NF-κB signaling pathway

Abstract

Objective: Several studies demonstrated that sulglycotide has anti-inflammatory and anti-cancer effects. However, the effect of sulglycotide is limited to gastric mucosal tissues and cells and underlying molecular mechanisms are not clear. This study estimated the effect of sulglycotide on lipopolysaccharide (LPS)-induced inflammatory responses in the macrophage cell line, RAW 264.7 and elucidated the molecular mechanisms.

Materials and methods: The inhibitory effect of sulglysotide on LPS-induced oxidative stress and inflammatory reactions were determined by Immunofluorescence staining, ELISA, Western blotting and RT-PCR.

Results: Our results show that sulglycotide has the ability to inhibit inflammatory mediators and cytokine production as well as reactive oxygen species (ROS) generation. This effect can be the result from regulating the activation of nuclear factor-kappa B (NF-κB) through blocking mitogen-activated protein kinase (MAPK) intracellular signaling pathways.

Conclusions: These results indicate that sulglycotide could be an anti-inflammatory and anti-oxidative compound that may be a useful candidate for treatment of inflammatory diseases.     

Can non-selective beta-blockers prevent hepatocellular carcinoma in patients with cirrhosis?

Hepatocellular carcinoma is the main liver-related cause of death in patients with compensated cirrhosis. The early phases are asymptomatic and the prognosis is poor, which makes prevention essential. We propose that non-selective beta-blockers decrease the incidence and growth of hepatocellular carcinoma via a reduction of the inflammatory load from the gut to the liver and inhibition of angiogenesis.     

细菌脂多糖对人根尖牙乳头干细胞自噬作用研究

目的　研究细菌脂多糖（lipopolysaccharide,LPS）对人根尖牙乳头干细胞（stem cells from apical palilla,SCAP）自噬的作用及影响,以探讨年轻恒牙根尖周炎损伤与修复的分子机制。方法　原代分离培养人SCAP,采用不同质量浓度（0.05、0.5、5 μg/mL）的细菌LPS处理SCAP记为LPS处理组,未加入细菌LPS的记为对照组。Western blot检测各组自噬相关基因5（autophagy related gene 5,Atg5）及自噬调节蛋白P62的表达情况,透射电子显微镜观察细菌LPS对SCAP自噬泡形态及数量的影响,数据采用SPSS18.0软件进行统计学分析。结果　原代培养的人SCAP表达间充质干细胞表面标志物CD73、CD90、CD105,不表达造血干细胞表面标记物CD45,体外诱导培养具有成骨向分化潜能。Western blot结果显示,各组间Atg5和P62的表达总的比较差异具有统计学意义（F值分别为118.227、74.144,P < 0.05）。Atg5的表达随处理组细菌LPS质量浓度的增大而升高,其中0.05 μg/mL LPS处理组Atg5相对表达量低于对照组,5 μg/mL LPS处理组Atg5相对表达量高于对照组,差异均具有统计学意义（均P < 0.05）。与对照组相比,0.5、5 μg/mL LPS处理组P62的表达降低,其中5 μg/mL LPS组P62相对表达量最低,差异均有统计学意义（均P < 0.05）。透射电子显微镜观察发现,与对照组相比,LPS处理组自噬泡数量显著增加。结论　细菌LPS能够促进人SCAP自噬的发生,提示在炎性环境下自噬可能对人SCAP生物学性能的调控发挥重要作用。     

染料木素通过TIPE 2负性调控Akt活性促进脂多糖活化的巨噬细胞凋亡

目的探究染料木素(genistein,GEN)对脂多糖(lipopolysaccharide,LPS)活化的RAW264.7细胞凋亡的影响及其可能的药理学作用机制。方法GEN预孵育RAW264.7细胞或慢病毒介导的肿瘤坏死因子α诱导蛋白8样分子2(tumor necrosis factor-α-induced protein 8-like 2,TIPE 2)过表达细胞2 h,再与LPS共孵育24 h,采用CCK 8试剂盒检测细胞活力,Annexin V-FITC/PI试剂盒检测细胞凋亡水平,qRT-PCR检测TNF-α、IL-6、caspase-8、caspase-3和TIPE 2 mRNA,Western blot检测iNOS、COX-2、caspase-8、caspase-3、TIPE 2、Akt和p-Akt蛋白表达。结果LPS促进RAW264.7细胞TNF-α、IL-6、iNOS、COX-2合成;GEN抑制LPS活化的RAW264.7细胞活力,凋亡细胞增多,并上调caspase-8、caspase-3、TIPE 2 mRNA及蛋白表达;TIPE 2过表达上调活化RAW264.7细胞caspase-8、caspase-3 mRNA及蛋白表达,减少Akt磷酸化,且与GEN具有协同作用。结论GEN可能通过上调TIPE 2抑制Akt活性,激活外源性凋亡途径,促进LPS活化的RAW264.7细胞凋亡。     

24-hour pattern of circulating prolactin and growth hormone levels and submaxillary lymph node immune responses in growing male rats subjected to social isolation

To assess the effect of social isolation of growing rats on 24-h rhythmicity of circulating prolactin and growth hormone (GH) levels and submaxillary lymph node immune responses, male Wistar rats were either individually caged or kept in groups (4–5 animals per cage) for 30 d starting on d 35 of life. Plasma prolactin and GH levels, and submaxillary lymph node lymphocyte subset populations, interferon (IFN)-γ release and mitogenic responses to concanavalin A (Con A) and lipopolysaccharide (LPS) were determined at six time intervals during the 24 h span. Social isolation brought about changes in mean values and 24-h pattern of plasma prolactin and GH levels and lymph node immune responses. After isolation, prolactin and GH mean values decreased, and lymph node T, B, non T-non B, CD8⁺, and CD4⁺-CD8⁺ cells augmented, whereas lymph node CD4⁺/CD8⁺ ratio, IFN-γ release and mitogenic responses decreased. Social isolation resulted in disruption of 24 h rhythmicity of every immune parameter tested. CD4⁺/CD8⁺ ratio, IFN-γ release and Concanavalin A (Con A) and lipopolysaccharide (LPS) responses correlated significantly with plasma prolactin or GH levels while T/B ratio correlated with plasma prolactin levels only. B, non T-non B, and CD4⁺-CD8⁺ cells correlated negatively with plasma prolactin. Modifications in mean value and 24-h rhythmicity of plasma prolactin and GH levels are presumably involved in the effect of social isolation on immune responsiveness.     

脂多糖对肺动脉内皮细胞Ⅰ型Na+/H+交换器表达的影响

目的 :探讨脂多糖 （ LPS）对培养的牛肺动脉内皮细胞 （ PAEC） 型 Na+ /H+交换器 （ NHE-1）表达的影响及其与内皮细胞死亡的关系。方法 :体外培养牛 PAEC,MTT比色检测细胞存活率 ,并提取总 RNA,应用反转录聚合酶链式反应 （ RT-PCR）及 DNA电泳技术 ,以 NHE-1与β-actin电泳条带光密度值之比 （ e/c）作数据分析 ,以其比值反映 NHE-1m RNA的表达程度。应用 Fluo3 /Amy荧光探针标记 ,激光共聚焦观察细胞内钙离子的浓度。结果 :在L PS（ 0 .0 1～ 1.0 μg/ml）作用 48h后 ,MTT比色吸光度值分别为 0 .3 5± 0 .0 7,0 .3 1± 0 .0 7,0 .2 6± 0 .0 4,低于对照组 0 .44± 0 .0 6（ P<0 .0 1）。e/c分别为 0 .43± 0 .11,0 .83± 0 .14 ,1.2 2± 0 .19,高于对照组 0 .2 8± 0 .0 8（ P<0 .0 1,n=4）。激光共聚焦结果显示 L PS引起细胞内钙离子增多 ,呈剂量依赖型。结论 :LPS可以引起肺动脉内皮细胞NHE-1表达增加 ,抑制细胞增殖 ,导致细胞死亡 ,钙离子可能参与 NHE-1的激活及表达。