Abstract
Abstract: :
Purpose: The process of lens fiber cell differentiation requires multiple cell signaling pathways, including a FGF signaling cascade. While this cascade results in a permanent alteration in gene expression, not all transcription factors involved in this process are yet known. However, one transcription factor family known to be regulated by FGF is the Ets family. This family of transcription factors has a characteristic winged helix–turn–helix binding domain that is conserved throughout all of its members. A specific member, Ets2, has been shown previously in our lab to be expressed in the lens transition zone as epithelial cells commit to become lens fiber cells. Methods: In order to explore the global expression of the Ets family, RNA was extracted and purified from adult Swiss–Webster and 16dpc whole lens as well as from isolated adult lens epithelia and lens fiber cells. Expression levels in these samples were then assessed through Q–RT–PCR. Those family members that displayed a high expression level were further studied using immunohistochemistry. Results: The expression pattern of 25 Ets family members was explored in the lens using Q–RT–PCR. However, only 6 members displayed significant levels of expression. In the adult whole lens, ERM and TEL were expressed at the highest levels. When contrasting the lens epithelia to the lens fiber cells, ERM, TEL, ER81, ELK4, and Ets2 were found to be expressed in high levels in the epithelia, while only ERM was expressed significantly in the fiber cells. Lastly, in the 16dpc murine whole lens, high expression of ERM, ER81, TEL, ELK4, and Ets2 was detected. Those Ets family members exhibiting high expression levels were selected to be further studied using IHC. Preliminary IHC results show consistency with Q–RT–PCR findings. Conclusions: Specific Ets family members, such as Ets2, ERM, ER81, TEL, and ELK4 are expressed at high levels in murine lens tissue. Therefore, through possible interactions with the FGF pathway, Ets family members may play an important role in the process of lens fiber cell differentiation.
Keywords: transcription factors • gene/expression