A Computational Model Predicting Disruption of Blood Vessel Development

Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis) and remodeling (angiogenesis) come from a variety of biological pathways linked to endothelial cell (EC) behavior, extracellular matrix (ECM) remodeling and the local generation of chemokines and growth factors. Simulating these interactions at a systems level requires sufficient biological detail about the relevant molecular pathways and associated cellular behaviors, and tractable computational models that offset mathematical and biological complexity. Here, we describe a novel multicellular agent-based model of vasculogenesis using the CompuCell3D (http://www.compucell3d.org/) modeling environment supplemented with semi-automatic knowledgebase creation. The model incorporates vascular endothelial growth factor signals, pro- and anti-angiogenic inflammatory chemokine signals, and the plasminogen activating system of enzymes and proteases linked to ECM interactions, to simulate nascent EC organization, growth and remodeling. The model was shown to recapitulate stereotypical capillary plexus formation and structural emergence of non-coded cellular behaviors, such as a heterologous bridging phenomenon linking endothelial tip cells together during formation of polygonal endothelial cords. Molecular targets in the computational model were mapped to signatures of vascular disruption derived from in vitro chemical profiling using the EPA''s ToxCast high-throughput screening (HTS) dataset. Simulating the HTS data with the cell-agent based model of vascular development predicted adverse effects of a reference anti-angiogenic thalidomide analog, 5HPP-33, on in vitro angiogenesis with respect to both concentration-response and morphological consequences. These findings support the utility of cell agent-based models for simulating a morphogenetic series of events and for the first time demonstrate the applicability of these models for predictive toxicology.     

铅锌镉联合染毒及营养干预对大鼠血液系统的影响研究

目的：了解铅锌镉联合染毒对大鼠血液系统的影响及营养干预对其损伤的修复作用。方法：选择SPF级初断乳Wistar大鼠72只,随机分为对照组、染毒组和干预组,分别采用生理盐水、铅锌镉联合染毒液及染毒后以营养干预液灌胃28天和56天之后,检测其血液系统中五元素和血细胞的指标。结果：染毒组较对照组大鼠血铜、血锌含量高,血钙含量低于对照组,差异均有统计学意义（P〈0．05）;染毒组血铜含量高于干预组,血钙含量低于干预组,差异均有统计学意义（P〈0．05）;干预组红细胞（RBC）计数、血红蛋白（Hb）、血细胞比容（HCT）均高于染毒组,差异均有统计学意义（P〈0．05）;对照组白细胞（WBC）计数高于染毒组、干预组,差异均有统计学意义（P〈0．05）。结论：铅镉对大鼠血铜、血钙、血锌水平有影响;综合营养干预对重金属元素造成的血液系统损伤有明显的拮抗作用,对血液系统有一定的保护及修复作用。     

Resistance to Diet-Induced Obesity and Associated Metabolic Perturbations in Haploinsufficient Monocarboxylate Transporter 1 Mice

The monocarboxylate transporter 1 (MCT1 or SLC16A1) is a carrier of short-chain fatty acids, ketone bodies, and lactate in several tissues. Genetically modified C57BL/6J mice were produced by targeted disruption of the mct1 gene in order to understand the role of this transporter in energy homeostasis. Null mutation was embryonically lethal, but MCT1 ^+/− mice developed normally. However, when fed high fat diet (HFD), MCT1 ^+/− mice displayed resistance to development of diet-induced obesity (24.8% lower body weight after 16 weeks of HFD), as well as less insulin resistance and no hepatic steatosis as compared to littermate MCT1 ^+/+ mice used as controls. Body composition analysis revealed that reduced weight gain in MCT1 ^+/− mice was due to decreased fat accumulation (50.0% less after 9 months of HFD) notably in liver and white adipose tissue. This phenotype was associated with reduced food intake under HFD (12.3% less over 10 weeks) and decreased intestinal energy absorption (9.6% higher stool energy content). Indirect calorimetry measurements showed ∼ 15% increase in O₂ consumption and CO₂ production during the resting phase, without any changes in physical activity. Determination of plasma concentrations for various metabolites and hormones did not reveal significant changes in lactate and ketone bodies levels between the two genotypes, but both insulin and leptin levels, which were elevated in MCT1 ^+/+ mice when fed HFD, were reduced in MCT1 ^+/− mice under HFD. Interestingly, the enhancement in expression of several genes involved in lipid metabolism in the liver of MCT1 ^+/+ mice under high fat diet was prevented in the liver of MCT1 ^+/− mice under the same diet, thus likely contributing to the observed phenotype. These findings uncover the critical role of MCT1 in the regulation of energy balance when animals are exposed to an obesogenic diet.     

Modification of reactive oxygen species scavenging capacity of chloroplasts through plastid transformation

Reactive oxygen species (ROS), including superoxide anions, hydrogen peroxide and hydroxyl radicals are generated through normal biochemical processes, but their production is increased by abiotic stresses. The prospects for enhancing ROS scavenging, and hence stress tolerance, by direct gene expression in a vulnerable cell compartment, the chloroplast, have been explored in tobacco. Several plastid transformants were generated which contained either a Nicotiana mitochondrial superoxide dismutase (MnSOD) or an Escherichia coli glutathione reductase (gor) gene. MnSOD lines had a three-fold increase in MnSOD activity, but interestingly a five to nine-fold increase in total chloroplast SOD activity. Gor transgenic lines had up to 6 times higher GR activity and up to 8 times total glutathione levels compared to wild type tobacco. Photosynthetic capacity of transplastomic plants, as measured by chlorophyll content and variable fluorescence of PSII was equivalent to non-transformed plants. The response of these transplastomic lines to several applied stresses was examined. In a number of cases improved stress tolerance was observed. Examples include enhanced methyl viologen (Paraquat)-induced oxidative stress tolerance in Mn-superoxidase dismutase over-expressing plants, improved heavy metal tolerance in glutathione reductase expressing lines, and improved tolerance to UV-B radiation in both sets of plants.     

Rapid synthesis of VX-745: p38 MAP kinase inhibition in Werner syndrome cells

The p38 mitogen-activated protein kinase inhibitor VX-745 is prepared rapidly and efficiently in a four-step sequence using a combination of conductive heating and microwave-mediated steps. Its inhibitory activity was confirmed in hTERT immortalized HCA2 and WS dermal fibroblasts at 0.5-1.0 microM concentration by ELISA and immunoblot assay, and displays excellent kinase selectivity over the related stress-activated kinase JNK.     

Microwave-assisted synthesis of 5-aminopyrazol-4-yl ketones and the p38(MAPK) inhibitor RO3201195 for study in Werner syndrome cells

5-Aminopyrazol-4-yl ketones are prepared rapidly and efficiently using microwave dielectric heating from beta-ketonitriles by treatment with N,N'-diphenylformamidine followed by heterocyclocondensation by irradiation with a hydrazine. The inhibitory activity of RO3201195 prepared by this methodology was confirmed in hTERT-immortalized HCA2 and WS dermal fibroblasts at 200nM concentration, both by ELISA and immunoblot assay, and displays excellent kinase selectivity for p38alpha MAPK over the related stress-activated kinase JNK.     

Dopamine receptor genetic polymorphisms and body composition in undernourished pastoralists: An exploration of nutrition indices among nomadic and recently settled Ariaal men of northern Kenya

Background  

Minor alleles of the human dopamine receptor polymorphisms, DRD2/TaqI A and DRD4/48 bp, are related to decreased functioning and/or numbers of their respective receptors and have been shown to be correlated with body mass, height and food craving. In addition, the 7R minor allele of the DRD4 gene is at a higher frequency in nomadic compared to sedentary populations. Here we examine polymorphisms in the DRD2 and DRD4 genes with respect to body mass index (BMI) and height among men in two populations of Ariaal pastoralists, one recently settled (n = 87) and the other still nomadic (n = 65). The Ariaal live in northern Kenya, are chronically undernourished and are divided socially among age-sets.