Effects of increased tissue oxygen tension on dermal aging

组织氧张力增加对真皮老化的影响

基本信息

批准号：
23700827
负责人：
KAWADA Shigeo
金额：
$ 2.75万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Young Scientists (B)
财政年份：
2011
资助国家：
日本
起止时间：
2011 至 2012
项目状态：
已结题

项目摘要

The aim of this study was to investigate whether increased dermal oxygen tension attenuates ultraviolet (UV)-B-induced dermal angiogenesis and wrinkle formation.In experiment 1, the backs of the mice were exposed to UVB three times per week for a5-wk. To increase dermal oxygen tension, the mice were exposed to hyperoxia (90% oxygen) for 2 h immediately after each UVB irradiation. This experiment cleared that such acute UVB exposure results in wrinkle formation associated with increased cutaneousangiogenesis. However, hyperoxic exposure immediately after UVB exposure attenuates these phenomena.In experiment 2, we investigated the effects of hyperoxia on dermal aging induced by higher doses and longer periods of UVB irradiation. The backs of the mice were exposed to UVB three times per week for a 10-wk. Hyperoxic conditions could suppress increases in hypoxia-inducible factor (HIF)-1α levels, a key molecule for angiogenesis. However, UVB-induced wrinkle formation and angiogenesis were not attenuated. Activities of matrix metalloproteinases (MMP)-2 and MMP-9, which are key molecules in wrinkle formation, increased with higher-dose and longer-term UVB irradiation regardless of exposure to hyperoxic conditions. In experiment 1, MMP-2 and MMP-9 activities did not increase. These results suggest that suppression of increases in HIF-1α levels alone is insufficient to suppress wrinkle formation caused by higher doses and longer periods of UVB irradiation. Moreover, MMP-2 and MMP-9 might not play a critical role in either wrinkle formation or angiogenesis during the early stage of acute UVB-induced wrinkle formation.

这项研究的目的是研究增加的皮肤氧张力会减弱紫外线（UV）B诱导的皮肤血管生成和包裹形成。在实验1中，小鼠的背部每周暴露于UVB 3次，每周3次。为了增加皮肤氧张力，在每次UVB辐射后立即将小鼠暴露于高氧（90％氧）中2小时。该实验清除了这种急性UVB暴露会导致与皮肤疗法增加有关的包裹形成。然而，在UVB暴露后立即暴露于这些现象。在实验2中，我们研究了高剂量较高剂量和更长的UVB辐照时期高氧对皮肤衰老的影响。小鼠的背部每周三次暴露于UVB，10周。高氧条件可以抑制缺氧诱导的因子（HIF）-1α水平的增加，这是血管生成的关键分子。但是，UVB诱导的包裹形成和血管生成并未减弱。基质金属蛋白酶（MMP）-2和MMP-9的活性，它们是包裹形成中的关键分子，随着暴露于高氧状况如何，随着较高剂量和长期的UVB辐射而增加。在实验1中，MMP-2和MMP-9活性没有增加。这些结果表明，仅抑制HIF-1α水平的升高不足以抑制由较高剂量和更长的UVB辐射引起的包裹形成。此外，在急性UVB诱导的包裹形成的早期，MMP-2和MMP-9可能在包裹形成或血管生成中起关键作用。