Prof. Volker Enzmann
Dept. of Ophthalmology
University of Berne
Phone: +41 31 632 89 35
Fax: +41 31 632 48 82
Activties and Research Interests
Age-related macular degeneration (AMD) is the leading cause of visual impairment in the elderly in industrialized nations. Several approaches aim to replace damaged retinal tissue including the retinal pigment epithelium (RPE), unfortunately mostly unsuccessful. Therefore, adult stem cells came in the research focus to achieve this goal. Neural stem cells (NSC) differentiate into neuronal or glial cell types but show also the potential to turn into a range of unrelated cell types. Our aim is to optimize this process to the point that the SC can be used to repair damaged RPE morphologically and functionally in vivo.
To accomplish this goal, we will examine the differentiation time course long the RPE lineage using different culture systems including coculture, growth factor and RPE-conditioned supernatant treatment. We will investigate not only the kinetics of marker expression and functional activity in vitro but also test the ability to replace damaged RPE in the NaIO3 model of retinal degeneration. The ultimate goal of our research is the use of pre-committed SC as a therapeutic tool for patients with dry AMD.
Furthermore, endogenous regeneration in the mammalian retina is very limited. In contrast, zebrafish can regenerate damaged retina quite successfully via activation and differentiation of their Müller cells. Similar activation happens in mice but the system lacks the following differentiation into photoreceptors. Therefore, we are interested to investigate similarities and difference in a common model of pharmacologically induced retinal degeneration and actively modulate this processes towards effective regeneration.
- Tappeiner C, Balmer J, Iglicki M, Schuerch K, Jazwinska A, Enzmann V, Tschopp M. Characteristics of rod regeneration in a novel zebrafish retinal degeneration model using N-methyl-N-nitrosourea (MNU). PLOSone 2013; 8(8):e71064.
- Zulliger R, Lecaudé S, Eigeldinger-Berthou S, Wolf-Schnurrbusch UE, Enzmann V. Caspase-3-independent photoreceptor degeneration by N-methyl-N-nitrosourea (MNU) induces morphological and functional changes in the mouse retina. Graefes Arch Clin Exp Ophthalmol. 2011; 249(6):859-69.
- Franco LM, Zulliger R, Wolf-Schnurrbusch UE, Katagiri Y, Kaplan HJ, Wolf S, Enzmann V. Decreased visual function after patchy loss of retinal pigment epithelium induced by low-dose sodium iodate. Invest Ophthalmol Vis Sci. 2009; 50(8):4004-10.
- Enzmann V, Yolcu E, Kaplan HJ, Ildstad ST. Stem cells as tools in regenerative therapy for retinal degeneration. Arch Ophthalmol. 2009;127(4):563-71.
- Li Y, Atmaca-Sonmez P, Schanie CL, Ildstad ST, Kaplan HJ, Enzmann V. Endogenous bone marrow derived cells express retinal pigment epithelium cell markers and migrate to focal areas of RPE damage. Invest Ophthalmol Vis Sci. 2007; 48(9):4321-7.
- Atmaca-Sonmez P, Li Y, Yamauchi Y, Schanie CL, Ildstad ST, Kaplan HJ, Enzmann V. Systemically transferred hematopoietic stem cells home to the subretinal space and express RPE-65 in a mouse model of retinal pigment epithelium damage. Exp Eye Res. 2006; 83(5):1295-302.
- Li Y, Reca RG, Atmaca-Sonmez P, Ratajczak MZ, Ildstad ST, Kaplan HJ, EnzmannV. Retinal pigment epithelium damage enhances expression of chemoattractants and migration of bone marrow-derived stem cells. Invest Ophthalmol Vis Sci. 2006; 47(4):1646-52.
- Enzmann V, Row BW, Yamauchi Y, Kheirandish L, Gozal D, Kaplan HJ, McCall MA. Behavioral and anatomical abnormalities in a sodium iodate-induced model of retinal pigment epithelium degeneration. Exp Eye Res. 2006; 82(3):441-8.
- Enzmann V, Howard RM, Yamauchi Y, Whittemore SR, Kaplan HJ. Enhanced induction of RPE lineage markers in pluripotent neural stem cells engrafted into the adult rat subretinal space. Invest Ophthalmol Vis Sci. 2003; 44(12):5417-22.