Phillip A. Sharp

Bio: Phillip A. Sharp is an academic researcher from Massachusetts Institute of Technology. The author has contributed to research in topics: RNA & RNA splicing. The author has an hindex of 172, co-authored 614 publications receiving 117126 citations. Previous affiliations of Phillip A. Sharp include McGovern Institute for Brain Research & Medical Research Council.

Inhibition of the facilitative sugar transporters (GLUTs) by tea extracts and catechins.

Abstract: Tea polyphenolics have been suggested to possess blood glucose lowering properties by inhibiting sugar transporters in the small intestine and improving insulin sensitivity In this report, we studied the effects of teas and tea catechins on the small intestinal sugar transporters, SGLT1 and GLUTs (GLUT1, 2 and 5) Green tea extract (GT), oolong tea extract (OT), and black tea extract (BT) inhibited glucose uptake into the intestinal Caco-2 cells with GT being the most potent inhibitor (IC50 : 0077 mg/mL), followed by OT (IC50 : 0136 mg/mL) and BT (IC50 : 056 mg/mL) GT and OT inhibition of glucose uptake was partial non-competitive, with an inhibitor constant (Ki ) = 00317 and 00571 mg/mL, respectively, whereas BT was pure non-competitive, Ki = 036 mg/mL Oocytes injected to express small intestinal GLUTs were inhibited by teas, but SGLT1 was not Furthermore, catechins present in teas were the predominant inhibitor of glucose uptake into Caco-2 cells, and gallated catechins the most potent: CG > ECG > EGCG ≥ GCG when compared to the non-gallated catechins (C, EC, GC, and EGC) In Caco-2 cells, individual tea catechins reduced the SGLT1 gene, but not protein expression levels In contrast, GLUT2 gene and protein expression levels were reduced after 2 hours exposure to catechins but increased after 24 hours These in vitro studies suggest teas containing catechins may be useful dietary supplements capable of blunting postprandial glycaemia in humans, including those with or at risk to Type 2 diabetes mellitus

Alternative RNA splicing in the endothelium mediated in part by Rbfox2 regulates the arterial response to low flow.

Abstract: Low and disturbed blood flow drives the progression of arterial diseases including atherosclerosis and aneurysms. The endothelial response to flow and its interactions with recruited platelets and leukocytes determine disease progression. Here, we report widespread changes in alternative splicing of pre-mRNA in the flow-activated murine arterial endothelium in vivo. Alternative splicing was suppressed by depletion of platelets and macrophages recruited to the arterial endothelium under low and disturbed flow. Binding motifs for the Rbfox-family are enriched adjacent to many of the regulated exons. Endothelial deletion of Rbfox2, the only family member expressed in arterial endothelium, suppresses a subset of the changes in transcription and RNA splicing induced by low flow. Our data reveal an alternative splicing program activated by Rbfox2 in the endothelium on recruitment of platelets and macrophages and demonstrate its relevance in transcriptional responses during flow-driven vascular inflammation.

Crispr mediated in vivo modeling and genetic screening of tumor growth and metastasis

Abstract: The present invention relates to in vivo methods for modeling tumor formation and/or tumor evolution comprising the use of eukaryotic cells in which one or more genetic target locus has been altered by the CRISPR/Cas system, and which cells are transplanted in non-human eukaryote as a model system for tumor formation and tumor evolution. In particular in vivo genetic screening methods for identifying genes involved in tumorigenesis and metastasis are disclosed. The invention further relates to kits and components for practicing the methods, as well as materials obtainable by the methods, in particular tumor and metastasis samples and cells or cell lines derived therefrom. The invention also relates to diagnostic and therapeutic methods derived from the information obtained in the modeling methods.

Single-cell variability guided by microRNAs

Abstract: A single zygote with a defined DNA sequence gives rise to all the varied cells of the mammalian body. This variety of cell fates may arise in part from cell-to-cell variability in the gene expression programs of embryonic stem cells (ESCs). Three recent studies have taken different approaches to characterizing this variability in gene expression in stem cells ( 1 – 3 ). These results suggest that microRNAs (miRNAs) could play an important role in controlling and generating this variability.

Measurement of suppressor transfer RNA activity

Abstract: Transfer RNA (tRNA) suppression of nonsense mutations in prokaryotic systems has been widely used to study the structure and function of different prokaryotic genes. Through genetic engineering techniques, it is now possible to introduce suppressor (Su+) tRNA molecules into mammalian cells. A quantitative assay of the suppressor tRNA activity in these mammalian cells is described; it is based on the amount of tRNA-mediated readthrough of a terminating codon in the influenza virus NS1 gene after the cells are infected with virus. Suppressor activity in L cells continuously expressing Su+ (tRNAtyr) was 3.5 percent and that in CV-1 cells infected with an SV40- Su+ (tRNAtyr) recombinant was 22.5 percent.

Initial sequencing and analysis of the human genome.

Abstract: The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

A rapid alkaline extraction procedure for screening recombinant plasmid DNA

Abstract: A procedure for extracting plasmid DNA from bacterial cells is described. The method is simple enough to permit the analysis by gel electrophoresis of 100 or more clones per day yet yields plasmid DNA which is pure enough to be digestible by restriction enzymes. The principle of the method is selective alkaline denaturation of high molecular weight chromosomal DNA while covalently closed circular DNA remains double-stranded. Adequate pH control is accomplished without using a pH meter. Upon neutralization, chromosomal DNA renatures to form an insoluble clot, leaving plasmid DNA in the supernatant. Large and small plasmid DNAs have been extracted by this method.