Hb New York,preliminary results concerning the hematologic characteristics and the effects on thalassemia

Molecular Biology Reports - The hematological phenotype and genotype analysis of hemoglobin New York (Hb New York) combined with α or β thalassemia has been rarely reported, and whether...     

蛋白质纯化虚拟仿真课程的教学设计

目的 蛋白质纯化是医学与生物学实验教学课程中的一个重要内容，本文通过设计新的蛋白质纯化虚拟仿真教学内容，开发虚拟仿真教学系统，希望学生能够更有效率地掌握蛋白质纯化技术的要点，提升教学质量。方法 利用3D虚拟仿真技术，构建虚拟仿真实验室。结合线下教学经验，确定虚拟仿真教学中需要体现的教学内容、教学重点、核心仪器的特色、评分指标、考核方式、操作体验等。结果 本文基于3D虚拟仿真技术构建了蛋白质纯化虚拟仿真实验室，和传统教学相比，虚拟仿真教学可以提高教学效率，节省教学成本和场地占用；教学设计和虚拟仿真教学系统融合了教学、练习和考核模块，根据以往的教学经验优化了评分体系，保证学生更加有效、严谨地掌握技术细节；涵盖了全新的教学内容——荧光检测联用的分子排阻层析，添加了蛋白质层析的常用案例，保证了内容的新颖与实用；完全再现了现实实验室中仪器设备的搭建模式，实现虚拟学习与实际操作的无缝衔接。结论 蛋白质纯化虚拟仿真教学系统由虚及实，由点及面，把控细节，保证学生动手能力和探索能力的提高，学以致用，并且拥有传统教学模式不可比拟的优势。     

Rational Design of a Fibroblast Growth Factor 21-Based Clinical Candidate,LY2405319

Fibroblast growth factor 21 is a novel hormonal regulator with the potential to treat a broad variety of metabolic abnormalities, such as type 2 diabetes, obesity, hepatic steatosis, and cardiovascular disease. Human recombinant wild type FGF21 (FGF21) has been shown to ameliorate metabolic disorders in rodents and non-human primates. However, development of FGF21 as a drug is challenging and requires re-engineering of its amino acid sequence to improve protein expression and formulation stability. Here we report the design and characterization of a novel FGF21 variant, LY2405319. To enable the development of a potential drug product with a once-daily dosing profile, in a preserved, multi-use formulation, an additional disulfide bond was introduced in FGF21 through Leu118Cys and Ala134Cys mutations. FGF21 was further optimized by deleting the four N-terminal amino acids, His-Pro-Ile-Pro (HPIP), which was subject to proteolytic cleavage. In addition, to eliminate an O-linked glycosylation site in yeast a Ser167Ala mutation was introduced, thus allowing large-scale, homogenous protein production in Pichia pastoris. Altogether re-engineering of FGF21 led to significant improvements in its biopharmaceutical properties. The impact of these changes was assessed in a panel of in vitro and in vivo assays, which confirmed that biological properties of LY2405319 were essentially identical to FGF21. Specifically, subcutaneous administration of LY2405319 in ob/ob and diet-induced obese (DIO) mice over 7–14 days resulted in a 25–50% lowering of plasma glucose coupled with a 10–30% reduction in body weight. Thus, LY2405319 exhibited all the biopharmaceutical and biological properties required for initiation of a clinical program designed to test the hypothesis that administration of exogenous FGF21 would result in effects on disease-related metabolic parameters in humans.     

Theoretical Insights into Catalytic Mechanism of Protein Arginine Methyltransferase 1

Protein arginine methyltransferase 1 (PRMT1), the major arginine asymmetric dimethylation enzyme in mammals, is emerging as a potential drug target for cancer and cardiovascular disease. Understanding the catalytic mechanism of PRMT1 will facilitate inhibitor design. However, detailed mechanisms of the methyl transfer process and substrate deprotonation of PRMT1 remain unclear. In this study, we present a theoretical study on PRMT1 catalyzed arginine dimethylation by employing molecular dynamics (MD) simulation and quantum mechanics/molecular mechanics (QM/MM) calculation. Ternary complex models, composed of PRMT1, peptide substrate, and S-adenosyl-methionine (AdoMet) as cofactor, were constructed and verified by 30-ns MD simulation. The snapshots selected from the MD trajectory were applied for the QM/MM calculation. The typical S_N2-favored transition states of the first and second methyl transfers were identified from the potential energy profile. Deprotonation of substrate arginine occurs immediately after methyl transfer, and the carboxylate group of E144 acts as proton acceptor. Furthermore, natural bond orbital analysis and electrostatic potential calculation showed that E144 facilitates the charge redistribution during the reaction and reduces the energy barrier. In this study, we propose the detailed mechanism of PRMT1-catalyzed asymmetric dimethylation, which increases insight on the small-molecule effectors design, and enables further investigations into the physiological function of this family.     

Nuclear factor-κB-dependent epithelial to mesenchymal transition induced by HIF-1α activation in pancreatic cancer cells under hypoxic conditions

Background

Epithelial to mesenchymal transition (EMT) induced by hypoxia is one of the critical causes of treatment failure in different types of human cancers. NF-κB is closely involved in the progression of EMT. Compared with HIF-1α, the correlation between NF-κB and EMT during hypoxia has been less studied, and although the phenomenon was observed in the past, the molecular mechanisms involved remained unclear.

Methodology/Principal Findings

Here, we report that hypoxia or overexpression of hypoxia-inducible factor-1α (HIF-1α) promotes EMT in pancreatic cancer cells. On molecular or pharmacologic inhibition of NF-κB, hypoxic cells regained expression of E-cadherin, lost expression of N-cadherin, and attenuated their highly invasive and drug-resistant phenotype. Introducing a pcDNA3.0/HIF-1α into pancreatic cancer cells under normoxic conditions heightened NF-κB activity, phenocopying EMT effects produced by hypoxia. Conversely, inhibiting the heightened NF-κB activity in this setting attenuated the EMT phenotype.

Conclusions/Significance

These results suggest that hypoxia or overexpression of HIF-1α induces the EMT that is largely dependent on NF-κB in pancreatic cancer cells.     

ATF2与ATF3在结直肠癌中表达及临床病理意义

目的：观察结直肠癌组织中活化转录因子2（ATF2）和活化转录因子3（ATF3）的表达并分析其表达的临床病理意义。方法：收集结直肠癌病例,明确其病理诊断并收集临床资料,应用免疫组织化学SP法检测活化转录因子2和活化转录因子3蛋白的表达。结果：ATF2在癌旁肠组织、腺瘤、腺癌组的阳性表达率分别为38%,32%,64%,差异有统计学意义,其中癌旁肠组织、腺瘤分别与腺癌有显著性差异。ATF3在癌旁肠组织、腺瘤、腺癌组的阳性表达率分别为56%,44%,52%,差异无统计学意义。ATF2表达与浸润肠壁深度,淋巴结转移有关,而与肿块大小、部位、分化程度无关。ATF3表达与肿块直径、浸润肠壁深度,而与淋巴结转移、部位、分化程度无关。结论：ATF2与结直肠癌反生和发展有关,而ATF3与结直肠癌的恶性演进有关。     

Evidence of a Monoaminergic-Cholinergic Imbalance Related to Visual Hallucinations in Lewy Body Dementia

Senile dementia of Lewy body type is characterized clinically by a relatively acute onset of fluctuating memory loss and confusion, frequently accompanied by visual hallucinations. Neurochemical analyses of temporal cortex has revealed a distinction between hallucinating and nonhallucinating patients in both cholinergic and monaminergic transmitter activities. In contrast with the cholinergic enzyme choline acetyltransferase, which was more extensively reduced in hallucinating individuals, serotonergic S2 receptor binding and both dopamine and serotonin metabolites were significantly decreased in nonhallucinating cases. These results suggest that an imbalance between monaminergic and cholinergic transmitters is involved in hallucinogenesis in the human brain.