The Effect of Endothelial Cells on UVB‐induced DNA Damage and Transformation of Keratinocytes In 3D Polycaprolactone Scaffold Co‐culture System

Abstract

Nitric oxide ( ) plays an important role in the regulation of redox balance in keratinocytes post-UVB exposure. Since endothelial cells releases for a prolonged time post-UVB, we determined whether human umbilical vein endothelial cells (HUVEC) could have an effect on UVB-induced DNA damage and transformation of their adjacent keratinocytes (HaCaT) using a 3D cell co-culturing system. Our data show that the levels of DNA breaks and/or cyclobutane pyrimidine dimer (CPD) along with γH2AX are higher in the co-cultured than in the mono-cultured keratinocytes post-UVB. The level in the co-cultured cells is increased approximately 3-fold more than in mono-cultured HaCaT cells within 1-hour post-UVB but then is reduced quickly in co-cultured HaCaT cells comparing to mono-cultured cells from 6 to 24 h post-UVB. However, the peroxynitrite (ONOO ) level is higher in the co-cultured than in the mono-cultured HaCaT cells in whole period post-UVB. Furthermore, while expression level of inducible nitric oxide synthase (iNOS) is increased, the ratio of coupled/uncoupled eNOS is reduced in co-cultured HaCaT cells compared to mono-cultured HaCaT cells. Finally, the co-cultured cells have a significantly increased transformation efficiency after repeating UVB exposure compared to mono-culture HaCaT cells. Our results suggest that endothelial cells could enhance /ONOO imbalance and promote transformation of adjacent keratinocytes.

s-HBEGF/SIRT1 circuit-dictated crosstalk between vascular endothelial cells and keratinocytes mediates sorafenib-induced hand–foot skin reaction that can be reversed by nicotinamide

“…For instance, ultraviolet radiation B (UVB) could induce vascular endothelial cells to secrete nitric oxide (NO) which promotes the DNA damage and the genetic transformation of their adjacent keratinocytes. 23 In this study, we unravel the mechanism of sorafenib-induced HFSR by revealing the crosstalk between vascular endothelial cells and keratinocytes wherein s-HBEGF released from vascular endothelial cells stabilizes sirtuin 1 (SIRT1), an essential keratinization inducer in keratinocytes, and ultimately gives rise to HFSR. Based on such mechanistic insights, we further demonstrate HBEGF neutralization antibody and classic SIRT1 inhibitor nicotinamide could reverse sorafenib-induced HFSR, hence providing potentially promising therapeutic strategies for the treatment of this toxicity.…”