Flavan-3-ols, flavonoids, anthocyanidins and triterpenoids induces TIE2 phosphorylation -a candidate target for the vascular protective effects.

Vascular system is essential for the body to maintain health. Dysregulated vascular system leads to cardiovascular diseases and are observed in ischaemic stroke, Alzheimer's disease, amyotrophic lateral sclerosis, and diabetes. TIE2 is a tyrosine kinase receptor expressed on vascular endothelial cells and contributes to the maintenance of a vascular system. In this paper, we screened for natural products with an activity to induce phosphorylation of TIE2, which will be beneficial for protection of a vascular system. Employing HeLa cells expressing TIE2, flavan-3-ols, flavonoids, anthocyanidins and triterpenoids were identified as active compounds that induce TIE2 phosphorylation. Several of the identified compounds are previously reported to protect endothelial cells from inflammation. Thus, the result provided TIE2 as the candidate receptor protein of those compounds for the protective effect of endothelial cells and the identified compounds will be a good candidate for maintenance of a vascular system.

Generation and maintenance of acentric stable double minutes from chromosome arms in inter-species hybrid cells.

BACKGROUND: Extrachromosomal acentric double minutes (DMs) contribute to human malignancy by carrying amplified oncogenes. Recent cancer genomics revealed that the pulverization of defined chromosome arms (chromothripsis) may generate DMs, however, nobody had actually generated DMs from chromosome arm in culture. Human chromosomes are lost in human-rodent hybrid cells. RESULTS: We found that human acentric DMs with amplified c-myc were stable in human-rodent hybrid cells, although the degree of stability depended on the specific rodent cell type. Based on this finding, stable human-rodent hybrids were efficiently generated by tagging human DMs with a plasmid with drug-resistance gene. After cell fusion, human chromosomes were specifically pulverised and lost. Consistent with chromothripsis, pulverization of human chromosome arms was accompanied by the incorporation into micronuclei. Such micronucleus showed different replication timing from the main nucleus. Surprisingly, we found that the hybrid cells retained not only the original DMs, but also new DMs without plasmid-tag and c-myc, but with human Alu. These DMs were devoid of telomeres and centromeres, and were stable in culture for more than 3 months. Microarray analysis showed that the new DMs were generated from several human chromosomal regions containing genes advantageous for cellular growth. Such regions were completely different from the original DMs. CONCLUSIONS: The inter-species hybrid mimics the chromothripsis in culture. This is the first report that experimentally demonstrates the generation of multiple stable acentric DMs from the chromosome arm.