RESUMEN
The aim of this study was to examine the possible association of vitamin D deficiency with diabetic retinopathy in 75 young Japanese type 1 diabetic patients. A multivariate regression analysis, duration of diabetes and vitamin D deficiency were independent determinants of diabetic retinopathy.
Asunto(s)
25-Hidroxivitamina D 2/sangre , Glucemia/metabolismo , Diabetes Mellitus Tipo 1/complicaciones , Retinopatía Diabética/etiología , Hemoglobina Glucada/metabolismo , Medición de Riesgo , Deficiencia de Vitamina D/etiología , Adulto , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/epidemiología , Retinopatía Diabética/sangre , Retinopatía Diabética/epidemiología , Femenino , Humanos , Incidencia , Japón/epidemiología , Masculino , Factores de Riesgo , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/epidemiologíaRESUMEN
Catechins in green tea display anti-cancer and anti-angiogenesis activities. We previously found that some catechins, such as epigallocatechin-3-O-gallate (EGCG), inhibit the activities of eukaryotic DNA polymerases (pols) (Y. Mizushina et al.: Structural analysis of catechin derivatives as mammalian DNA polymerase inhibitors. Biochem Biophys Res Commun 333, 101-109 (2005)). In this study, we discuss the effects of chemical modifications of catechin and epicatechin that enhance their anti-cancer and anti-angiogenic activities based on pol inhibition. Catechins conjugated with fatty acid (3-O-acylcatechins) are stronger inhibitors of mammalian pol than epicatechins conjugated with fatty acid (3-O-acylepicatechins). Moreover, 3-O-acylcatechins are more potent inhibitors of cultured cell growth both of the human colon carcinoma cell line (HCT116 cells) and human umbilical vein endothelial cell (HUVEC) line, as well as angiogenesis by comparison with 3-O-acylepicatechins. Catechin conjugated with stearic acid ((2R,3S)-3',4',5,7-tetrahydroxyflavan-3-yl octadecanoate; C-C18) was the strongest inhibitor in replicative pol alpha and repair-related pol beta, as well as the cultured cell growth and angiogenesis assays in the compounds tested. C-C18 also suppressed HUVEC tube formation on reconstituted basement membrane suggesting that it affected not only pols but also signal transduction pathways in HUVECs. These data indicate that the acylated catechins target both pols and angiogenesis as anti-cancer agents. Moreover, the results suggest that acylation of catechin is an effective chemical modification to improve the anti-cancer activity of catechin.