Identification of the SHREK Family of Proteins as Broad-Spectrum Host Antiviral Factors

Mucins and mucin-like molecules are highly glycosylated, high-molecular-weight cell surface proteins that possess a semi-rigid and highly extended extracellular domain. P-selectin glycoprotein ligand-1 (PSGL-1), a mucin-like glycoprotein, has recently been found to restrict HIV-1 infectivity through virion incorporation that sterically hinders virus particle attachment to target cells. Here, we report the identification of a family of antiviral cellular proteins, named the Surface-Hinged, Rigidly-Extended Killer (SHREK) family of virion inactivators (PSGL-1, CD43, TIM-1, CD34, PODXL1, PODXL2, CD164, MUC1, MUC4, and TMEM123) that share similar structural characteristics with PSGL-1. We demonstrate that SHREK proteins block HIV-1 infectivity by inhibiting virus particle attachment to target cells. In addition, we demonstrate that SHREK proteins are broad-spectrum host antiviral factors that block the infection of diverse viruses such as influenza A. Furthermore, we demonstrate that a subset of SHREKs also blocks the infectivity of a hybrid alphavirus-SARS-CoV-2 (Ha-CoV-2) pseudovirus. These results suggest that SHREK proteins may be a part of host innate immunity against enveloped viruses.     

Venlafaxine alters microvascular perfusion, [I]-beta-CIT binding and BDI scores in flushing postmenopausal women

Background

Although 70% of postmenopausal women suffer from hot flashes the pathophysiology is poorly understood. The serotonin and noradrenaline reuptake inhibitor (SNRI) venlafaxine provides relief of flushing although the mechanism is unknown and could involve a central effect and/or a peripheral effect. Using single photon emission computed tomography (SPECT) we studied the central serotonin transporter (SERT) in vivo using [¹²³I]-beta-carbomethoxy-3-β-(4-iodophenyl)tropane (beta-CIT) and, as previous studies have shown that reactivity of the skin blood vessels is enhanced in those who flush, we examined cutaneous microvascular perfusion.

Methods

Cutaneous microvascular perfusion was assessed in 31 postmenopausal women, with flushing, using laser Doppler imaging with iontophoresis (LDI + ION), before and after 8 weeks of treatment with venlafaxine. A sub-group of 14 of these women also had SPECT imaging at both time points to evaluate the availability of SERT in the brain. Flush frequency and score was recorded, and Beck Depression Inventory (BDI) II scores were assessed before and after treatment.

Results

Following treatment with venlafaxine, there was a significant reduction in the [¹²³I]-beta-CIT binding ratio, BDI scores, flushing and endothelial dependent perfusion response. [¹²³I]-Beta-CIT reduction was associated with BDI reduction (r² = 0.54; F = 8.8; p = 0.004), but not flushing reduction or perfusion reduction.

Conclusions

Venlafaxine resulted in a decrease in BDI II scores with an associated reduction in [¹²³I]-beta-CIT binding in a group of non-depressed women. It also improved flush frequency and severity which may be as a result of decreases seen in enhanced cutaneous microvascular perfusion.     

Neuroimaging in dementia

Over the last few years, advances in neuroimaging have generated biomarkers, which increase diagnostic certainty, provide valuable information about prognosis, and suggest a particular pathology underlying the clinical dementia syndrome. We aim to review the evidence for use of already established imaging modalities, along with selected techniques that have a great potential to guide clinical decisions in the future. We discuss structural, functional and molecular imaging, focusing on the most common dementias: Alzheimer's disease, fronto-temporal dementia, dementia with Lewy bodies and vascular dementia. Finally, we stress the importance of conducting research using representative cohorts and in a naturalistic set up, in order to build a strong evidence base for translating imaging methods for a National Health Service. If we assess a broad range of patients referred to memory clinic with a variety of imaging modalities, we will make a step towards accumulating robust evidence and ultimately closing the gap between the dramatic advances in neurosciences and meaningful clinical applications for the maximum benefit of our patients.     

记忆合金支架捆绑碘-125粒子治疗食管癌的临床应用

目的:探讨附有碘-125粒子的医用记忆合金食管支架置入对晚期食管恶性狭窄的疗效．方法:45例晚期食管癌按患者是否愿意接受碘-125粒子支架而将其分为A、B两组,A组为普通自膨式支架,B组为附有碘-125粒子的自膨式食管支架进行治疗．术后随访并发症及生存期．结果:45例患者支架全部顺利置放,支架置入成功率100％,患者吞咽困难均得到明显缓解． A组患者生存时间90-300 d,平均171±56 d．B 组患者生存时间120-450 d,平均316±116 d．两者比较有统计学意义(t=-3．385,P<0．05)．两组均未出现严重并发症．结论:附有碘-125粒子的自膨式食管支架能明显缓解吞咽困难症状,明显提高患者生活质量及生存期,且无严重并发症发生．     

Tracing Leukemia Stem Cells and Their Influence on Clinical Course of Adult Acute Myeloid Leukemia

BackgroundAcute myeloid leukemia (AML) evolves from neoplastic transformation of stem cell disease termed “leukemia stem cells” (LSCs). An unsatisfactory response to AML therapy is determined by the presence of minimal residual disease (MRD). The predominance of LSCs might anticipate sustained MRD results. The present study aimed to demonstrate the effect of LSCs on MRD at induction days 14 and 28 on overall survival (OS) and disease-free survival (DFS) and to compare LSC expression with MRD status.Patients and MethodsA total of 84 patients with de novo adult AML underwent testing using LSC panels for CD38/CD123/CD34/CD45 and CD90/CD133/CD45/CD33 and different regular MRD panels.ResultsAt day 14 after induction, the high expression of CD123 and CD133 had adverse effects on both OS and DFS (P = .004 and P ≤ .001 and P ≤ .001 and P ≤ .001, respectively). Greater expression of CD34⁺/CD38⁻/CD123⁺ resulted in unfavorable OS and DFS (P ≤ .001 for both). Both CD34⁺/CD38⁻/CD123⁺ and CD34⁻/CD38⁺/CD123⁺ expression at day 14 after induction had an adverse effect on DFS only (P < .001 and P = .029, respectively). On multivariate analysis, CD133 expression and MRD status were independent prognostic parameters (hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.2-4.4; P = .015; and HR, 2.9; 95% CI, 1.0-7.9; P = .041). At day 28 after induction, MRD and increased CD123⁺/CD34⁻, CD34⁺/CD38⁻/CD123⁺, CD133⁺/CD33⁻ expression were associated with inferior OS (P = .016, P = .0035, P = .0.002, and P = .002, respectively). MRD and high expression of CD34⁺CD123⁺, CD133⁺/CD33⁻, CD34⁺/CD38⁻/CD123⁺ were associated with inferior DFS (P < .001, P = .002, P < .001, P < .001, respectively). On multivariate analysis, only CD133⁺/CD33⁻ expression was the independent prognostic factor (HR, 3.1; 95% CI, 1.5-6.7; P = .003).ConclusionsEstimation of LSC expression is a sensitive indicator of the response to therapy in adult patients with AML and might be a better prognosticator than the findings from regular MRD panels.     

合成成骨生长肽对人骨髓间充质干细胞成骨转化的促进

背景：成骨生长肽在体内外细胞培养中具有明显的促成骨活性,这种促成骨作用的分子机制还不清楚,现已通过人工方法成功制备了合成成骨生长肽。 目的：探讨合成成骨生长肽对体外培养的人骨髓间充质干细胞向成骨方向分化的作用。 设计、时间及地点：基因和蛋白水平的细胞学体外观察,于2006-07/2007-12在福建省医学科学研究所基因工程实验室及复旦大学附属中山医院中心实验室完成。 材料：骨髓标本来源于福建省立医院骨一科收治的男性髂骨植骨患者,合成成骨生长肽由中国科学院上海生命科学研究院生物化学与细胞生物学研究所崔大敷教授惠赠,ERK1/2抑制剂U0126为美国CST公司产品。 方法：密度梯度离心法体外分离培养人骨髓间充质干细胞,单纯矿化液组加入由10 mmol/Lβ-甘油磷酸钠、50 mg/L L-抗坏血酸组成的矿化液;10-7,10-9,10-11 mol/L合成成骨生长肽组分别加入对应浓度的合成成骨生长肽,再加入矿化液;常规培养组加入含体积分数为0.1胎牛血清的低糖DMEM。 主要观察指标：倒置显微镜观察细胞形态变化,RT-PCR法和免疫组织化学染色检测成骨标志物的表达,Western-blot法分析合成成骨生长肽对ERK1/2信号通路的影响,观察U0126对合成成骨生长肽作用的干预。 结果：加入合成成骨生长肽后,骨髓间充质干细胞体积增大,突起增多,呈多角形,胞浆含有较多颗粒状物质,出现致密细胞结节。合成成骨生长肽在mRNA和蛋白水平均能促进成骨标志物碱性磷酸酶、Ⅰ型胶原、骨钙素的表达,定量分析结果显示10-9 mol/L合成成骨生长肽促成骨作用最强。加入合成成骨生长肽后能够引起ERK1/2信号通路的持续性激活,经U0126预处理后几乎完全阻断了合成成骨生长肽对骨髓间充质干细胞的促成骨作用。 结论：合成成骨生长肽可明显促进人骨髓间充质干细胞向成骨方向的转化,在10-9 mol/L浓度下促成骨能力最强,其促成骨作用可能是通过激活MAPK家族ERK1/2途径实现的。     

基因干扰机制及其在细胞信号转导中的应用

基因干扰是一种新兴的基因阻断技术,是外源和内源性双链RNA在细胞内使特异性序列的基因表达受抑。基因干扰技术能高效特异的阻断基因的表达,可以确定复杂的信号传导途径中不同基因的上下游关系,是研究信号转导通路的有力工具。基因干扰技术可有效抑制目的基因表达mRNA以及蛋白质产物,其可以简便、特异、高效、稳定地下调目的基因的表达,亦可在不影响其他物质的情况下,剔除目的基因。基因干扰技术比以前用于基因功能研究和应用的各种方法更优秀,但基因干扰技术对于哺乳动物细胞株的转染效率低;哺乳动物细胞中对双链RNA或小干扰RNA的导入会产生拮抗作用等方面亦有待改进。将有效且具高度安全性的小干扰RNA用于医疗,前景令人期待。