Contrasting associations of polymorphisms in FcγRIIa and DC-SIGN with the clinical presentation of dengue infection in a Mexican population

Dengue virus (DENV) causes a spectrum of illness from asymptomatic infection, to a mild febrile illness, to occasional more severe complications including hemorrhage and shock. Dengue is endemic in the state of Morelos, Mexico. Two single nucleotide polymorphisms (SNPs), rs1801274 of FcγRIIa and rs4804803 of DC-SIGN, have been associated with protection from or susceptibility to severe dengue infection. Both of these polymorphisms are located in genes for receptors with important roles in dengue pathogenesis, and their relationship with the clinical presentation of dengue infection in Mexican populations is unknown. In this study, real-time PCR was used to characterize the distribution of rs1801274 and rs4804803 in subjects with asymptomatic dengue infection (n = 145), uncomplicated dengue (n = 67), and severe dengue (n = 36) in Morelos. In contrast with previous studies, the histidine (A) variant of rs1801274 was associated with more mild infection: carrying the histidine allele (either homozygous or heterozygous) was associated with protection from symptomatic infection compared with asymptomatic (OR 0.51, p = 0.038). Histidine homozygotes were also less likely to present severe dengue (OR 0.34, p = 0.05). Logistic regression models confirm this association (OR 0.48, p = 0.04) and also indicate that the G allele of rs4804803 is associated with symptomatic dengue (OR 2.3, p = 0.08), after accounting for other biological factors including history of infection. This variant was rare in this study population, with a frequency of 5.4%. These findings reflect the complexity of influences on the development of severe dengue infection. The inclusion of asymptomatic infections and adjusted case definitions likely do not explain the entire disparity with previous findings. Interactions with other polymorphisms may explain why the association of rs1801274 is reversed in this population compared to others. This study demonstrates the importance of genetic association studies in multiple genetically distinct populations.     

Emerging biotherapies for Sjögren's syndrome

Importance of the field: Sjögren's syndrome (SS) is an autoimmune epithelitis. This exocrinopathy is frequently associated with extraglandular complications, and the patients are at risk of developing B cell lymphoma. Given the lack of disease-modifying drugs, and the fact that SS is a quintessential B-cell mediated disease, attention has recently been focused on biotherapies.

Areas covered in this review: Despite negative grounds, TNF-α antagonists have been tested in the disease, and proven not be efficient. However, B-cell depleting therapy using anti-CD20 antibodies such as rituximab, which is a chimeric mAb, has shown promise in the field, while anti-CD22 mAb seems to be less active.

What the reader will gain: New treatments against the B-cell activating factor of the TNF family are about to be tested, or replaced by receptor immunoglobulin decay protein.

Take home message: B-cell depleting therapies seem promising in SS, but no data are, thus far, available on treatments targeting B-cell activating factor of the TNF family.     

Scintillation proximity assay in lead discovery

Background: Scintillation proximity assay (SPA) is a homogeneous scintillant bead-based platform for the measurement of biological processes and plays an important role in the identification of active chemical entities in drug discovery. Objective: The design and development of solid-phase SPA approaches are examined and compared with alternative non-radiometric fluorescence-based technologies. Methods: This review provides background on the principle of SPA and its application to biomolecular interactions from a variety of biological sources. Conclusion: The SPA approach is well suited to the demands of commercial high volume automation and assay miniaturization for target-based high-throughput screening campaigns on synthetic and natural product libraries as well as for benchtop characterization and confirmation studies. In the near future, innovations in the way SPA and fluorescence-based screening strategies are multiplexed will improve our comprehensive understanding of cellular system biology and dramatically advance the lead discovery process for the treatment of complex target-related disorders.     

Induction of apoptosis by heat and γ-radiation in a human lymphoid cell line; role of mitochondrial changes and caspase activation

Purpose: The aim of the study was to investigate the molecular mechanisms involved in apoptosis of human promyelocytic cells (HL60) induced by hyperthermia and to compare this to radiation-induced apoptosis as a reference model.

Materials and methods: Apoptosis of HL60 cells was induced by heat-treatment (43°C during 1?h) or by γ-radiation (8?Gy) and followed at increasing time periods after treatment with Annexin V binding to phosphatidylserine (PS). The transition of the mitochondrial membrane potential (Δψ_m) was estimated by the extent of mitochondrial JC-1 uptake. Bcl-2 and Bax protein expression levels were monitored using fluorescent-labelled antibodies. Caspase activation was studied using a fluorochrome-labelled pan-caspase inhibitor (FLICA), which also allowed one to study the kinetics of the apoptotic cascade.

Results: After heat-treatment or irradiation of HL60 cells, a decreased Δψ_m as well as PS membrane expression were detectable after 8?h. Bcl-2 and Bax protein expression levels were decreased and increased, respectively, 1?h after heat-treatment or irradiation. The apoptotic rate of HL60 cells, as measured by the FLICA binding, was faster with heat-treatment as compared to γ-irradiation. Addition of a pan-caspase inhibitor prevented PS externalization after heat-treatment but not after irradiation. The presence of a pan-caspase inhibitor did not influence the decrease of Δψ_m both after heat-treatment and γ-irradiation. However, the addition of the specific caspase-2 inhibitor zVDVAD-fmk prevented the mitochondrial breakdown after heat-treatment. Inhibition of caspase-2 had no effect on the γ-irradiation induced apoptosis.

Conclusion: These results suggest that the commitment to apoptosis in HL60 cells after heat-treatment is started by mitochondrial membrane transition involving the Bcl-2 family members and is mainly executed in a caspase-dependent pathway. The results suggest that caspase-2 plays a key role in the heat-induced apoptosis.     

Inhibition of Notch signalling has ability to alter the proximal and distal TCR signalling events in human CD3+ αβ T-cells

The Notch signalling pathway is an important regulator of T cell function and is known to regulate the effector functions of T cells driven by T cell receptor (TCR). However, the mechanism integrating these pathways in human CD3⁺ αβ T cells is not well understood. The present study was carried out to investigate how Notch and TCR driven signalling are synchronized in human αβ T cells. Differential expression of Notch receptors, ligands, and target genes is observed on human αβ T cells which are upregulated on stimulation with α-CD3/CD28 mAb. Inhibition of Notch signalling by GSI-X inhibited the activation of T cells and affected proximal T cell signalling by regulating CD3-ζ chain expression. Inhibition of Notch signalling decreased the protein expression of CD3-ζ chain and induced expression of E3 ubiquitin ligase (GRAIL) in human αβ T cells. Apart from affecting proximal TCR signalling, Notch signalling also regulated the distal TCR signalling events. In the absence of Notch signalling, α-CD3/CD28 mAb induced activation and IFN-γ production by αβ T cells was down-modulated. The absence of Notch signalling in human αβ T cells inhibited proliferative responses despite strong signalling through TCR and IL-2 receptor. This study shows how Notch signalling cooperates with TCR signalling by regulating CD3-ζ chain expression to support proliferation and activation of human αβ T cells.     

熊去氧胆酸联合非诺贝特治疗PBC患者血清TGF-β、IFN-γ和IL-10水平变化*

目的 探讨熊去氧胆酸(UDCA)联合非诺贝特治疗原发性胆汁性胆管炎(PBC)患者血清转化生长因子-β(TGF-β)、γ-干扰素(IFN-γ)和白介素-10(IL-10)水平的变化。方法 2016年12月～2018年12月我科诊治PBC患者48例,随机将患者分为观察组(n=24)和对照组(n=24)。给予对照组患者UDCA治疗半年,给予观察组UDCA联合非诺贝特口服治疗半年。采用ELISA法检测血清TGF-β、IFN-γ和IL-10水平。使用FibroTouch行肝脏硬度测定(liver stiffness measurement, LSM)。结果 在治疗观察结束时,观察组血清谷丙转氨酶水平为(51.4±23.7)U/L,显著低于对照组【(74.9±21.2)U/L,P<0.05】,谷草转氨酶为(59.5±32.3)U/L,显著低于对照组【(81.3±35.8)U/L,P<0.05】,谷氨酰转肽酶水平为(95.7±31.8)U/L,显著低于对照组【(127.3±50.7)U/L,P<0.05】;观察组血清IFN-γ水平为(57.4±21.3)pg/mL,显著高于对照组【(39.7±23.7)pg/mL,P<0.05】,而血清TGF-β水平为(14.3±4.8)pg/mL,显著低于对照组【(23.6±3.5)pg/mL,P<0.05】;观察组血清免疫球蛋M(IgM)为(2.3±0.4)g/L,显著低于对照组【(3.1±0.9)g/L,P<0.05】, IgG水平为(11.3±1.8)g/L,显著低于对照组【(15.5±1.3)g/L,P<0.05】,IgA水平为(2.7±0.6)g/L,显著低于对照组【(3.5±0.2)g/L,P<0.05】;观察组患者LSM为(10.8±6.5)kPa,与对照组的(9.7±7.7)kPa比,无统计学差异(P>0.05)。结论 熊去氧胆酸联合非诺贝特联合治疗PBC患者可以明显改善血生化指标,可能与抑制了免疫球蛋白水平和提高了血清IFN-γ水平有关,其治疗的远期疗效还有待于观察。     

闪式提取法提取五味子醇溶性有效成分的工艺研究

目的：优化闪式提取法提取五味子醇溶性有效成分的最佳工艺。方法以五味子乙素含量为考察指标,通过单因素考察试验,首先确定影响因素的显著性及影响范围,采用正交实验设计方法,优化闪式提取五味子醇溶性有效成分的最佳工艺。结果最佳工艺条件：10倍量浓度为80％乙醇浸泡4 h,闪式提取100 s。结论闪式提取法是一种高效、快速、简单的提取方法,适合醇溶性有效成分的提取。     

PPARγ在子宫内膜异位症中的作用研究进展

现有的研究已阐明激活PPARγ具有抑制炎症反应、抗血管生成等作用,而炎症反应和血管生成均参与了子宫内膜异位症的发生发展,并且PPARγ在正常子宫内膜组织及异位子宫内膜组织均有表达。PPARγ在子宫内膜异位症中的作用受到越来越多的关注,该文就PPARγ在子宫内膜异位症中的意义作一综述。