Growth factors are playing an important role in healing and regeneration of retina. They are group of proteins that stimulate the growth of specific tissues including retina. They promote cellular differentiation and cell division, and they occur in a wide range of organisms including human. Several proteins are used therapeutically. To find out more about the role of growth factors in the area of retina tissue engineering we have studied the comparison of these specific protein interactions.

Referring to the Regeneration Gene Database [1] there are 21 protein coding genes that have influence on retina regeneration. Consequently a systems biology study has run. Actually a PPI network got created by STRING App of Cytoscape software. This network has 21 nodes and 37 edges. In order to study the biological process of each protein, a GO analysis was performed.

According to GO analysis, 4 proteins have the most influence in retina regeneration: SHH, IGF1, STAT3 and ASCL1. These proteins have the highest degree in the PPI network. By the study of biological process of mentioned proteins, the role of each one in Retina regeneration has clarified. SHH (Sonic hedgehog) is a protein, which is functional in embryo formation. Hedgehog pathway also plays an important role as a modulator of retina regeneration [3]. Insulin-like growth factor (IGF1) has an impact on growth promoting activity. IGF1 is a key molecule that induces RGC apoptosis or RGC survival and regeneration in the retina during the early stage of optic nerve injury [4]. Furthermore, Muller glia cells are kind of cells in retina which support neurons like other glia cells. The role of STAT3 in regeneration process is providing maximum number proliferation of Muller glia cells in retina damage [5]. Also, ASCL1 is an important regulatory factor in retina regeneration. It needed to be there to help and convert dormant Muller glia to retinal progenitors that are able to divide [6].

by performing a degree centrality analysis mentioned four proteins have the most impact on retina regeneration. For the tissue engineering of retina, logically it is important to consider SHH, IGF1, STAT3 and ASCL1 for the tissue fabrication.