Adipokines in dental pulp: Physiological,pathological, and potential therapeutic roles

BackgroundHundreds of adipokines have been identified, and their extensive range of endocrine functions—regulating distant organs such as oral tissues—and local autocrine/paracrine roles have been studied. In dentistry, however, adipokines are poorly known proteins in the dental pulp; few of them have been studied despite their large number. This study reviews recent advances in the investigation of dental-pulp adipokines, with an emphasis on their roles in inflammatory processes and their potential therapeutic applications.HighlightsThe most recently identified adipokines in dental pulp include leptin, adiponectin, resistin, ghrelin, oncostatin, chemerin, and visfatin. They have numerous physiological and pathological functions in the pulp tissue: they are closely related to pulp inflammatory mechanisms and actively participate in cell differentiation, mineralization, angiogenesis, and immune-system modulation.ConclusionAdipokines have potential clinical applications in regenerative endodontics and as biomarkers or targets for the pharmacological management of inflammatory and degenerative processes in dental pulp. A promising direction for the development of new therapies may be the use of agonists/antagonists to modulate the expression of the most studied adipokines.     

Toll-like receptor 4 ligand can differentially modulate the release of cytokines by human platelets

Blood platelets link the processes of haemostasis and inflammation. This study examined the immunomodulatory factors released by platelets after Toll-Like Receptor 4 (TLR4) engagement on their surfaces. Monoclonal anti-human FcγRII Ab (IV.3)-treated human platelets were cultured with TLR4 ligands in the presence or absence of blocking monoclonal antibody to human TLR4. The release of sCD62p, epidermal growth factor (EGF), transforming growth factor β (TGFβ), interleukin (IL)-8, platelet activating factor 4 (PAF4), platelet-derived growth factor, α, β polypeptide (PDGF-AB), Angiogenin, RANTES (regulated upon activation, normal T-cell expressed, and presumably secreted) and sCD40L were measured by specific enzyme-linked immunosorbent assay. TLR4 ligand [ Escherichia coli lipopolysaccharide (LPS)] bound platelet TLR4, which differentially modulates the release of cytokines by platelets. It was noted that (i) sCD62p, IL-8, EGF and TGFβ release were each independent of platelet activation after TLR4 engagement; (ii) RANTES, Angiogenin and PDGF-AB concentration were weaker in platelet supernatant after TLR4 engagement; (iii) sCD40L and PAF4 are present in large concentration in the releaseate of platelets stimulated by TLR4 ligand. The effects of LPS from E. coli on the modulation of secretory factors were attenuated by preincubation of platelets with an anti-TLR4 monoclonal antibody, consistent with the immunomodulation being specifically mediated by the TLR4 receptor. We propose that platelets adapt the subsequent responses, with polarized cytokine secretion, after TLR4 involvement.     

脂多糖作用下血管内皮钙黏蛋白经网格蛋白和微囊介导胞吞后的亚细胞分布差异

目的 研究脂多糖(LPS)作用下血管内皮钙黏蛋白(VE-Cad)经不同的胞吞途径进入细胞后对VE-Cad亚细胞分布和细胞通透性的影响.方法 体外培养人血管内皮细胞株CRL-2922,观察LPS(10μg/ml)作用后不同时间点VE-Cad与Rab11(循环内颗粒标记物)及溶酶体相关膜蛋白2(LAMP2,晚期内颗粒/溶酶体标记物)的免疫共沉淀情况,网格蛋白胞吞抑制剂和微囊抑制剂对VE-Cad与Rab 11和LAMP2免疫共沉淀的影响,以及单层细胞通透性的变化.结果 LPS作用后1h,VE-Cad与Rab 11的免疫共沉淀明显增高(P＜0.05),随后逐渐降低;VE-Cad与LAMP2的免疫共沉淀在LPS作用后呈时间依赖性地增高(P＜0.05).网格蛋白胞吞抑制剂氯丙嗪(CPZ)可显著抑制LPS作用后VE-Cad与Rab 11免疫共沉淀的增高(P＜0.05),而微囊抑制剂非律平无此作用;微囊抑制剂非律平可显著抑制LPS作用后VE-Cad与LAMP2免疫共沉淀的增高(P＜0.05),而网格蛋白胞吞抑制剂无此作用.网格蛋白胞吞抑制剂可减轻LPS作用后1h单层细胞通透性的增高,而微囊抑制剂可减轻LPS作用后4h单层细胞通透性的增高(P＜0.05).结论 在LPS作用下VE-Cad分别经网格蛋白或微囊介导的胞吞进入细胞,分布于循环内颗粒或溶酶体中,从而导致不同程度的血管通透性增高.     

The Characteristics and Function of Bacterial Lipopolysaccharides and Their Endotoxic Potential in Humans

Cross-talk between enteral microbiota and human host is essential for the development and maintenance of the human gastrointestinal and systemic immune systems. The presence of lipopolysaccharides (LPS) lysed from the cell membrane of Gram-negative bacteria in the gut lumen is thought to promote the development of a balanced gut immune response whilst the entry of the same LPS into systemic circulation may lead to a deleterious pro-inflammatory systemic immune response.

Recent data suggest that chronically low levels of circulating LPS may be associated with the development of metabolic diseases such as insulin resistance, type 2 diabetes, atherosclerosis and cardiovascular disease. This review focuses on the cross-talk between enteral commensal bacteria and the human immune system via LPS. We explain the structural characterisation of the LPS molecule and its function in the bacteria. We then examine how LPS is recognised by various elements of the human immune system and the signalling pathways that are activated by the structure of the LPS molecule and the effect of various concentrations. Further, we discuss the sequelae of this signalling in the gut-associated and systemic immune systems i.e. the neutralisation of LPS and the development of tolerance to LPS.     

细菌脂多糖对选择性激光熔化技术制作的钴铬钼合金腐蚀行为的影响

目的 研究不同浓度细菌脂多糖（Lipopolysaccharides,LPS）对选择性激光熔化技术（Selective laser melting,SLM）制作的钴铬钼合金腐蚀行为的影响。方法 分别以SLM法及铸造法各制作12个钴铬钼合金试件,根据在腐蚀电解液中LPS浓度（0、0.15、15、150 μg/mL）不同分为4组,每组3个试件。采用电化学阻抗谱、动电位极化测试法分析2组合金试件在不同浓度脂多糖（LPS）中的腐蚀行为。结果 在单纯人工唾液中,SLM合金和铸造合金的腐蚀参数无统计学上的差异（P> 0.05）。当LPS浓度为150 μg/mL时,SLM合金和铸造合金的电阻（R_p）均显著下降且自腐蚀电流密度（I_corr）显著增大,但SLM合金的R_p值大于铸造合金且I_corr值较小（P< 0.05）。结论 LPS对SLM法和铸造法制作的钴铬钼合金的腐蚀行为均有不利影响,但对SLM法制作的合金的腐蚀影响小于铸造法制得的合金。     

健肝灵胶囊对小鼠免疫性肝炎的影响

目的研究健肝灵胶囊对小鼠免疫性肝损伤的影响.方法小鼠iv卡介苗(BCG)5×106个菌/只,10d后再iv脂多糖(LPS)7.5 μg/只,造成免疫性肝炎模型.结果健肝灵胶囊能明显降低免疫性肝炎模型小鼠血清丙氨酸转氨酶(ALT),并能显著减轻肝炎小鼠的肝指数和脾指数.结论健肝灵胶囊对小鼠免疫性肝损伤有保护作用.     

Effect of pH-Regulation on the Capture of Lipopolysaccharides from E. coli EH100 by Four-Antennary Oligoglycines in Aqueous Medium

Bacterial lipopolysaccharides (LPS) are designated as endotoxins, because they cause fever and a wide range of pathologies in humans. It is important to develop effective methodologies to detect trace quantities of LPS in aqueous systems. The present study develops a fine-tuning procedure for the entrapment of trace quantities of LPS from E. coli EH100. The capture agents are self-assemblies (tectomers) formed by synthetic four-antennary oligoglycine (C-(CH₂-NH-Gly₇)₄, T4). Based on previously performed investigations of bulk and adsorption-layer properties of aqueous solutions containing T4 and LPS, the optimal conditions for the entrapment interactions are further fine-tuned by the pH regulation of aqueous systems. A combined investigation protocol is developed, including dynamic light scattering, profile analysis tensiometry, microscopic thin-liquid-film techniques, and transmission electron microscopy. The key results are: (1) two types of complexes between T4 and LPS are generated—amphiphilic species and “sandwich-like” hydrophilic entities; the complexes are smaller at lower pH, and larger at higher pH; (2) an optimum range of pH values is established within which the whole quantity of the LPS is entrapped by the tectomers, namely pH = 5.04–6.30. The obtained data substantiate the notion that T4 may be used for an effective capture and the removal of traces of endotoxins in aqueous systems.     

还原型烟酰胺腺嘌呤二核苷酸磷酸氧化酶在脂多糖诱导的小鼠急性心肌损伤组织中的表达及意义

目的探讨还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶的非吞噬细胞氧化酶(Nox)家族在脂多糖(LPS)诱导的小鼠急性心肌损伤组织中的表达及意义。方法选取8~10周龄无特定病原体C57/BL6雄性小鼠30只,随机分为对照组和LPS组,每组15只。LPS组小鼠通过腹腔注射大剂量LPS(10 mg/kg)诱导急性心肌损伤模型,对照组腹腔注射等量生理盐水,观察6 h后取材,逆转录-聚合酶链反应(RT-PCR)检测Nox、B细胞淋巴瘤/白血病蛋白-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、半胱氨酸天门冬氨酸特异性蛋白酶3(Caspase 3)基因表达,Western blotting检测Nox 2、Nox 4、Bax、Bcl-2和Caspase 3蛋白表达,免疫组织化学法检测4羟基壬烯醛(4-HNE)表达,末端脱氧核糖核酸转移酶(Td T)介导的脱氧尿苷三磷酸(dUTP)切口末端标记技术(TUNEL)法检测心肌组织细胞凋亡,比较两组结果差异。使用SPSS 13.0统计软件对数据进行分析,两组比较采用t检验。结果相比对照组,LPS组小鼠心肌Nox 2、Nox 4、Bax基因和蛋白以及Caspase 3蛋白表达水平明显升高,Bcl-2基因和蛋白表达水平明显降低,差异具有统计学意义(P0.05)。免疫组织化学检测结果表明相比对照组,LPS组心肌组织4-HNE表达明显增加,差异具有统计学意义(P0.05)。TUNEL检测结果表明相比对照组,LPS组心肌组织心肌凋亡细胞明显增加,差异具有统计学意义(P0.05)。结论 NADPH氧化酶通过调控氧化应激和细胞凋亡参与急性心肌损伤的发生发展。     

高浓度富氢生理盐水对脂多糖诱导大鼠急性肺损伤的作用

［摘要］ 目的探讨高浓度富氢生理盐水对腹腔注射脂多糖诱导急性肺损伤的影响。 方法选取60只清洁级SD雄性大鼠,随机分为空白组、高浓度富氢生理盐水组、脂多糖组、脂多糖+高浓度富氢生理盐水组各15只。脂多糖组、脂多糖+富氢生理盐水组腹腔内注射脂多糖10 mg/kg制备大鼠脓毒症模型。富氢生理盐水组、脂多糖+富氢生理盐水组治疗组在术后即刻、3 h、6 h、12 h、18 h,以5 mL/kg高浓度富氢生理盐水腹腔注射。空白组、脂多糖组给予等量生理盐水腹腔注射。取支气管肺泡灌洗液检测中性粒细胞计数,取肺组织检测丙二醛(malondialdehyde,MDA)含量及超氧化物歧化酶（superoxide dismutase,SOD）、过氧化氢酶（catalase,CAT）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）活性,Western blot检测肺组织中核因子E-2-相关因子2（nuclear factor erythroid-2-related factor-2,Nrf2）和血红素加氧酶1（hemeoxygenase-1,HO-1）的表达,比较组间差异。 结果与脂多糖组比较,脂多糖+富氢生理盐水组大鼠7 d平均生存时间延长（P＜0.05）;与空白组比较,脂多糖组中性粒细胞计数、MDA含量均明显升高,SOD、CAT、GSH-Px活性均下降（P＜0.05）,肺组织中Nrf2和HO-1的蛋白表达上升（P＜0.05）;与脂多糖组比较,脂多糖+富氢生理盐水组中性粒细胞计数、MDA含量均减少,SOD、CAT、GSH-Px活性以及Nrf2和HO-1的蛋白表达均明显增加（P＜0.05）。 结论高浓度富氢生理盐水可延长脂多糖所致脓毒症大鼠平均生存时间,减少肺部炎症细胞、氧化应激,可能通过Nrf2/HO-1通路控制急性肺损伤。     

Human gingival fibroblasts release high‐mobility group box‐1 protein through active and passive pathways

Introduction:  The nuclear protein high‐mobility group box‐1 (HMGB1) acts as a late mediator of inflammation when secreted in the extracellular milieu. In this study, we examined the effect of lipopolysaccharides from periodontal pathogens and apoptotic and necrotic cell death on HMGB1 production in human gingival fibroblasts (HGF). Methods:  HGF from healthy periodontal tissue were cultured and stimulated with lipopolysaccharides (LPS) from Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Escherichia coli. We also initiated apoptotic and necrotic cell deaths in HGF. The HMGB1 released in the supernatants from stimulated or dying cells was measured. Immunocytochemical staining against HMGB1 was performed in LPS‐stimulated HGF. Results:  A significantly higher amount of HMGB1 was detected from necrotic and apoptotic HGF. LPS from A. actinomycetemcomitans, P. gingivalis, and E. coli significantly induced the production of HMGB1 in a time‐dependent manner. After 6 h of LPS stimulation, HMGB1 was present in the cytoplasm of cells whereas its location was mainly nuclear after 24 h. Conclusions:  LPS from two major periodontal pathogens, A. actinomycetemcomitans and P. gingivalis, induced HMGB1 secretion from HGF. Apoptotic and necrotic cell deaths resulted in the enhancement of HMGB1. Our results suggest that HGF can be a source of HMGB1 by both active secretion and passive release, and that HMGB1 from HGF may contribute to periodontal tissue destruction.