可调控Cathepsin K表达的miR-155、miR-29吸附海绵circELN的筛选及功能研究

The degeneration and accumulation of elastic fibers is the characteristic features of photoaged skin and the basic pathological and physiological changes of solar related skin diseases. Abroad researchers and our recent studies have not only confirmed the important role of Cathepsins in photoaged skin, but also verified that Cathepsin K is the major protease to degrade elastic fibers. Moreover, we recently have demonstrated that the expression of this enzyme was regulated via the MAPK/AP-1 pathway. Our recent studies also found that circELN is involved in skin photoaging and possibly regulating the expression of Cathepsin K. The circELN is a class of newly discovered non-coding circular RNA with regulatory function, and showed much more applied prospect as it resistant to nucleases more than the linear non-coding RNA such as miRNAs and IncRNAs. In this study, some technologies, eg. qRT-PCR，Fluorescent tracer and DLR will be performed to screen for the most specific and high efficient miR-155 and miR-29 sponge circELN that can silence miR-155 and miR-29 in order to regulate Cathepsin K via MAPK pathway from our previously discovered several circELNs that related to degrading of elastic fiber of photoaged skin. This study has important theoretical and applicable significance, because the results can not only elucidate the mechanism of skin photoaging and provide new tools for the future researches, but also benefit for developing the small molecules for the prevention and treatment of photoaging and solar related skin diseases.

弹性纤维的变性堆积是光老化及相关皮肤病的病理基础。国外及我们的前期研究证实Cathepsins在光老化中的作用，还证实Cathepsin K是降解弹性纤维的主要蛋白酶且其表达受MAPK/AP-1通路调控。我们最近又发现circELN参与调控Cathepsin K，而circELN是新近发现的一种具有调控功能、比miRNA和IncRNA更耐核酸酶水解、更具应用前景的非编码环状RNA。本研究拟采用qRT-PCR、荧光示踪、DLR等方法从我们前期发现的与光老化相关的circELN中筛选出一种能作为miR-155、miR-29吸附海绵，可以稳定高效地通过MAPK/AP-1信号通路调控Cathepsin K的表达，从而影响弹性纤维降解的circELN。本研究不仅可进一步揭示光老化的机制，且可为光老化的研究提供新方法，并能据此开发小分子药物用于光老化及相关皮肤病的预防和治疗，具有重要的理论和应用价值。

光老化是皮肤外源性衰老的过程，其中主要的变化是胶原的减少。环状RNA(circRNA)是新近发现的一种具有调控功能的非编码RNA，其在光老化及光相关疾病进展中的作用与机制备受关注。我们的研究初步发现circCOL3A1-859267与miRNA-29c有结合位点，下调circCOL3A1-859267表达水平后I型胶原蛋白mRNA和蛋白水平显著下降，上调circCOL3A1-859267表达水平能明显对抗慢性UVA照射HDFs所导致的I型胶原蛋白减少，表明circCOL3A1-859267与光老化胶原表达密切相关。本研究有助于揭示circRNA参与调控光老化的分子机制，并为皮肤光老化及光老化相关皮肤病的治疗和干预提供新的靶点和思路。