Abstract
Purpose::
The specific goal with the present study is to find markers useful for detection of certain porcine retinal cell types- and structures. The overall aim of our studies is to intervene or halt the progress of retinal degenerative diseases process by i) replacing lost neurons through cell grafting, using immature cells, i.e. stem/progenitor cells or ii) by protecting dying neurons via delivery of survival factors using cell grafting and/or nanotechnology. We have chosen to work with the pig retina, due to its many similarities with the human retina.
Methods::
Domestic adult female pigs of the Danish Landrace breed were utilized. We have used mono-and polyclonal antibodies and fluorescence immunocytochemistry. At least three to up to fifteen specimens were used per antibody examined. Each staining was evaluated with respect to specificity and sensitivity in identification of the individual cell types- and structures. Briefly, in order to phenotypically characterize grafted cells, double-fluorescent immunostainings with markers specific for the grafted cells (e.g carrying the reporter gene green fluorescent protein (GFP)) in combination with various retinal cell type- and structure markers are mostly used. In our work to develop a model of acute retinal ischemia we use single immunostainings for quantifying degeneration of certain retinal cell types. Also in analysis of neuroprotective treatments in the model, cell survival is studied by using single immunostainings.
Results::
Overall, all antibodies examined rendered a specific and stable staining, with little or no variation between specimens. The following cell type markers will be presented; NeuN (ganglion cells, displaced amacrines), parvalbumin (amacrine cells), bFGF (amacrine- and displaced amacrine cells, Müller cells), PKC (bipolar cells), calbindin (horizontal cells), recoverin (cones and rods), transducin (cones), Rho4d2 (rods), GFAP (Müller cells and astrocytes) and vimentin (Müller cells and astrocytes). For visualising synaptic layers synaptobrevin and calbindin were used. In addition, the marker ROM1 for photoreceptor outer segments was found to be expressed. The RPE was detected by using antibodies against cytokeratin and RPE65.
Conclusions::
Thus, here we present a range of cell type- and structure markers for the adult porcine retina. To our knowledge, some of these markers are here presented for the first time for the pig retina, i.e NeuN, parvalbumin, synaptobrevin and ROM1.
Keywords: ischemia • neuroprotection • immunohistochemistry