Doctoral dissertation

Dissertation: Calcium signaling can be used to assess maturity of human retinal pigment epithelium cells

Retinal pigment epithelial cells located in the back of the eyes are the ones, which nourish visual cells. Retinal pigment epithelial cells are implicated in a number of diseases, such as age-related macular degeneration, that lead to blindness. In her doctoral thesis, Amna Abu Khamidakh developed live-cell calcium imaging-based methods to assess the retinal pigment epithelium functions to gain new insights useful for biomedical applications such as in vitro drug testing or transplantation therapies.

Retinal degenerative disorders are the major reasons for irreversible blindness in elderly people in industrialized world. Because degeneration of a single layer of retinal pigment epithelial cells is mostly responsible for the diseases, scientists consider transplantation therapies, as well as targeting these cells with novel medications, as effective treatment approaches. The retinal pigment epithelial cells intended for transplantation and drug testing have been successfully generated in vitro from stem cells.

“The cells that we generate in vitro for biomedical applications not only have to look like the cells we need, but they have to behave like healthy retinal pigment epithelium. We chose to assess the cellular behavior by looking at waves of calcium ions in our retinal pigment epithelial cell cultures,” Amna says.

Calcium is a small ion that controls vital cellular processes throughout cell life. Its concentration alters rapidly in living cells in response to various stimuli. The aim of the thesis was to investigate how calcium signaling changes in retinal pigment epithelium when cells are going through different challenges: maturation, wounding or an external mechanical stimulation.

“Retinal pigment epithelial cells are constantly “talking” to each other via calcium signaling. What we found was really interesting: the type of conversation between the cells changes as the cells grow older, or if the cells are wounded, or touched with a pipette. These conversations can be recorded from living cells using the calcium imaging technique. We believe that, in the future, the analysis of the calcium-based intercellular communication can be used as a test to figure out whether the cells are ready for a transplantation or whether they feel good after a drug application,” Amna explains. 

The doctoral dissertation of M.Sc Amna Abu Khamidakh in the field of Biomedical sciences and engineering titled Assessment of Ca2+ Dynamics in Human Retinal Pigment Epithelial Cell Cultures will be publicly examined in the Faculty of Medicine and Health Technology at Tampere University at 12.00 on Friday, 7 June 2019, at F115 of the Arvo Building, Arvo Ylpön katu 34, Tampere. The Opponent will be Senior research fellow Sofija Andjelic from Ljubljana University Medical Centre, Slovenia. The Custos will be Professor Jari Hyttinen from Tampere University, Faculty of Medicine and Health Technology, Finland.

The dissertation is available online at the