Cell biology and pathology of liver sinusoidal endothelial cells

Growing evidence revealed that liver sinusoidal endothelial cells (SEC) play several important roles in physiology and pathology of the liver. It has been well understood that their structural characteristics, such as the membrane sieve and lack of basement membrane, facilitate direct contact of soluble and insoluble serum substances with hepatic parenchymal cells, resulting in enhancement of hepatic metabolic activity. In addition, SEC is now regarded as a member of the scavenger endothelial cells, which have potential to eliminate a variety of macromolecules from the blood circulation by receptor-mediated endocytosis. It is reported that molecules preferentially eliminated by SEC are denatured or modified proteins such as advanced glycation end products, extracellular matrix components including hyaluronic acid, and some lipoproteins. The nature of the scavenger receptors corresponding to these molecules remains to be clarified. Recently, it was noted that SEC has an antigen-presenting function similar to dendritic cells. Taken together, it is suggested that SEC, cooperating with Kupffer cells and hepatic dendritic cells, may partake of immunoregulatory functions in the liver. SEC also plays a pivotal role in the pathological process of ischemia-reperfusion injury following liver surgery and liver transplantation. Thus, it is of importance to elucidate the mechanisms of apoptosis and proliferation of SEC. Recent results on the regulation of growth and apoptotic signaling of SEC are discussed.     

Expression profiles and functional implications of p53-like transcription factors in thymic epithelial cell subtypes

In this study, we investigated the localization and functional significance of p53 tumor suppressor-like molecules, p63 and p73, in human thymic epithelial cells (TECs). Immunohistochemical studies showed particular distribution profiles of p63 and p73 in thymic epithelium, in which cortical TECs preferentially expressed p63 in their nuclei whereas subcapsular and medullary TECs expressed both p63 and p73 in their nuclei. The wide distribution of p63 in TECs was further suggested by studies using TECs of primary culture. In vitro studies using two human TEC lines demonstrated that p63 was capable of up-regulating intercellular adhesion molecule-1 (ICAM-1) and enhancing the production of IL-6 and IL-8. Moreover, in vitro studies also indicated that p73, but not p63, had the capacity to induce granulocyte macrophage colony stimulating factor (GM-CSF) and granulocyte colony stimulating factor (G-CSF) in the TEC lines. These findings suggest that p63 would regulate the cell adhesive property through ICAM-1/LFA-1 interaction and the production of IL-6 and IL-8, probably in all TEC subtypes. p73 in subcapslar and medullary TECs was suggested to play a role in the regulation of the production of GM-CSF and G-CSF, which might stimulate other stromal cells such as dendritic cells, macrophages and endothelial cells around these regions.     

The basophil activation test in wasp venom allergy: sensitivity, specificity and monitoring specific immunotherapy

BACKGROUND: As in vitro diagnosis of wasp venom sensitization by specific serum IgE has a sensitivity of only 60-80%, additional in vitro tests are desirable. Basophil activation is associated with the expression of CD63 and its measurement has been proposed as a novel in vitro test for immediate-type allergy. Furthermore, to date, no in vitro test exists to monitor successful specific immunotherapy (SIT) with wasp venom. Therefore, the potentially harmful sting challenge is still recommended. OBJECTIVE: We compared the CD63-based basophil activation test (BAT) in the diagnosis of wasp venom allergy with skin tests and measurement of specific IgE. Furthermore, we investigated whether BAT can predict the outcome of the sting challenge in patients on SIT. METHODS: Fifty patients with a systemic reaction caused by a wasp sting and 20 controls were studied. Intracutaneous tests were performed with wasp and bee venom in the suspected allergics. Specific IgE was determined by the CAP-FEIA method and basophil activation by flow cytometry upon double staining with anti-IgE/anti-CD63 mAb. Twenty-five patients were sting challenged 6 months after starting SIT and the BAT was repeated before challenge. RESULTS: Sensitivity of the intracutaneous tests, specific IgE and BAT was 100, 76, and 92%, respectively. Specificity of specific IgE and the BAT was 85 and 80%, respectively. The cut-off for a positive BAT was 15% CD63+ basophils. There was a positive correlation between IgE reactivity to wasp venom and the number of CD63+ basophils (r = 0.65). Although no patient had a systemic reaction upon sting challenge, in most subjects basophil activation did not decrease when compared with the BAT before SIT. CONCLUSIONS: Quantitation of basophil activation by CD63 expression is a valuable new in vitro method for diagnosis of allergy to hymenopteran venoms. The CD63-based BAT is a helpful tool for the complementation of routine diagnostic tests such as specific IgE as it increases sensitivity of in vitro detection of sensitization. However, this in vitro method does not offer an alternative to the sting challenge in monitoring successful SIT.     

Differential expression of microRNAs miR-21, miR-31, miR-203, miR-125a-5p and miR-125b and proteins PTEN and p63 in verrucous carcinoma of the head and neck

Odar K, Bo?tjan?i? E, Gale N, Glava? D & Zidar N
(2012) Histopathology  61, 257–265 Differential expression of microRNAs miR‐21, miR‐31, miR‐203, miR‐125a‐5p and miR‐125b and proteins PTEN and p63 in verrucous carcinoma of the head and neck Aims: To investigate the expression of microRNAs miR‐21, miR‐31, miR‐203, miR‐125a‐5p and miR‐125b and proteins phosphatase and tensin homologue (PTEN) and p63 in verrucous carcinoma (VC) of the head and neck. Methods and results: Thirty cases of VC, 50 cases of conventional squamous cell carcinoma (SCC) and 30 samples of normal epithelium of the head and neck were included. Real‐time polymerase chain reaction and immunohistochemistry were used to analyse the expression of microRNAs and proteins, respectively. In comparison to normal epithelium, miR‐21 was overexpressed in both VC and SCC and miR‐31 was overexpressed in VC and in well‐ and moderately differentiated SCC. Levels of miR‐203 were elevated in VC but unaltered or reduced in SCC, and levels of miR‐125a‐5p and miR‐125b were reduced in VC but unaltered in SCC. PTEN was down‐regulated in both VC and SCC, whereas p63 was down‐regulated in VC but up‐regulated in SCC. Differential expression of p63 in VC correlated inversely with the expression of miR‐21 and miR‐203. Conclusions: Differences between VC, SCC and normal epithelium in expression profiles of investigated molecules indicate their association with the pathogenesis and clinicopathological characteristics of VC. Our results suggest that some microRNAs and proteins, particularly miR‐125b, miR‐203 and p63, might be useful in the diagnosis of VC.     

Basophil activation test: Mechanisms and considerations for use in clinical trials and clinical practice

The basophil activation test (BAT) is a functional assay that measures the degree of degranulation following stimulation with allergen or controls by flow cytometry. It correlates directly with histamine release. From the dose-response curve resulting from BAT in allergic patients, basophil reactivity (%CD63⁺ basophils) and basophil sensitivity (EC₅₀ or similar) are the main outcomes of the test. BAT takes into account all characteristics of IgE and allergen and thus can be more specific than sensitization tests in the diagnosis of allergic disease. BAT reduces the need for in vivo procedures, such as intradermal tests and allergen challenges, which can cause allergic reactions of unpredictable severity. As it closely reflects the patients' phenotype in most cases, it may be used to support the diagnosis of food, venom and drug allergies and chronic urticaria, to monitor the natural resolution of food allergies and to predict and monitor clinical the response to immunomodulatory treatments, such as allergen-specific immunotherapy and biologicals. Clinical application of BAT requires analytical validation, clinical validation, standardization of procedures and quality assurance to ensure reproducibility and reliability of results. Currently, efforts are ongoing to establish a platform that could be used by laboratories in Europe and in the USA for quality assurance and certification.     

Ki-67、p63、bcl-2蛋白在葡萄胎妊娠与水肿性流产中的诊断价值

目的:研究Bcl-2、p63和Ki-67蛋白在鉴别完全性葡萄胎(CHM)、部分性葡萄胎(PHM)、水肿性流产(HA)中的应用价值。方法:收集山东大学齐鲁医院病理科2012年1月至2018年6月的妊娠早期葡萄胎(HM)与水肿性流产样本共139例。对以上病例样本重新阅片,同时结合p57免疫组化染色,筛选出CHM 55例,PHM 29例,HA 40例。对筛选出的样本行Bcl-2、p63、Ki-67免疫组化染色。结果:Ki-67用于鉴别HA与PHM的敏感度、特异性、阳性预测值(PPV)、阴性预测值(NPV)分别为82.5%、72.4%、80.5%和75.0%;p63用于鉴别HA与PHM的敏感度、特异性、PPV、NPV分别为95.0%、79.3%、86.4%和92.0%;p63联合Ki-67用于鉴别HA与PHM的敏感度、特异性、PPV、NPV分别为95.0%、79.3%、86.4%和92.0%。p63联合Ki-67用于鉴别HA与PHM的受试者工作特征(ROC)曲线下面积(0.934)显著高于p63(0.898),差异有统计学意义(P<0.05)。结论:Ki-67与p63用于鉴别PHM与HA具有一定的应用价值,联合使用Ki-67与p63鉴别PHM与HA比单独使用两者的准确性更高。     

Surface roughness mediates its effects on osteoblasts via protein kinase A and phospholipase A2

Earlier studies have shown that implant surface roughness influences osteoblast proliferation, differentiation, matrix synthesis and local factor production. Moreover, the responsiveness of osteoblasts to systemic hormones, such as 1,25-(OH)₂D₃, at the implant surface is also influenced by surface roughness and this effect is mediated by changes in prostaglandins. At present, it is not known which signaling pathways are involved in mediating cell response to surface roughness and how 1,25-(OH)₂D₃ treatment alters the activation of these pathways. This paper reviews a series of studies that have addressed this question. MG63 osteoblast-like cells were cultured on commercially pure titanium (cpTi) surfaces of two different roughnesses (R_a 0.54 and 4.92 μm) in the presence of control media or media containing 1,25-(OH)₂D₃ or 1,25-(OH)₂D₃ plus H8 (a protein kinase A inhibitor) or quinacrine (a phospholipase A₂ inhibitor). At harvest, the effect of these treatments on cell number and alkaline phosphatase specific activity was measured. Compared to cultures grown on the smooth surface, cell number was reduced on the rough surface. 1,25-(OH)₂D₃ inhibited cell number on both surfaces and inhibition of protein kinase A in the presence of 1,25-(OH)₂D₃ restored cell number to that seen in the control cultures. Inhibition of phospholipase A₂ in the presence of 1,25-(OH)₂D₃ caused a further reduction in cell number on the smooth surface, and partially reversed the inhibitory effects of 1,25-(OH)₂D₃ on the rough surface. Alkaline phosphatase specific activity was increased in cultures grown on the rough surface compared with those grown on the smooth surface; 1,25-(OH)₂D₃ treatment increased enzyme specific activity on both surfaces. Cultures treated with H8 and 1,25-(OH)₂D₃ displayed enzyme specific activity that approximated that seen in control cultures. Inhibition of phospholipase A₂ also inhibited the 1,25-(OH)₂D₃-dependent effect on the smooth surface, but on the rough surface there was an inhibition of the 1,25-(OH)₂D₃ effect as well as a partial inhibition of the surface roughness-dependent effect. The results indicate that surface roughness and 1,25-(OH)₂D₃ mediate their effects through phospholipase A₂, which catalyzes one of the rate-limiting steps in prostaglandin E₂ production. Further downstream, prostaglandin E₂ activates protein kinase A.     

ADULT综合征与Tp63基因突变

ADULT综合征是一种外胚层发育异常疾病,属常染色体显性遗传,临床表现为四肢发育畸形、神经性皮炎改变(包括指/趾剥脱性皮炎)、皮肤干燥、乳腺和乳头发育不全或缺失、缺指(趾)畸形和并指症、指(趾)甲发育异常、泪管闭锁、少汗、牙齿发育不全等症状,该病由Tp63基因错义突变所引起.Tp63基因主要在各种上皮组织的发育、分化和形态发生过程中起作用,对于胚胎形成过程的外胚层发育具有重要的意义.研究发现ADULT综合征与Tp63基因外显子3'、4、6、8的核苷酸发生错义突变相关.Tp63基因的突变位点不同导致临床表现存在差异,即使突变位点相同,患者的临床表现还存在地域、种族和个体差异.本文就ADULT综合征的临床表现与Tpi3基因突变的关系进行综述.