Abstract
Purpose :
MANF was first discovered in the conditional medium of a rat type-1 astrocyte cell line VMCL1 (the ventral mesencephalic cell line 1) as a factor that promotes the survival of cultured embrayonic dopaminergic neurons. It also significantly reduces the infarction in the ischemic cortex in a rat model of stroke and promotes the survival of cultured heart muscle cells. We have shown that recombinant human MANF protects photoreceptors and retinal ganglion cells. The present work examines the temporal and spatial expression patterns of endogenous MANF in rodent retina.
Methods :
For immunoblotting, retinas of different age groups of Sprague Dawley rats were dissected, snap frozen on dry ice, and stored at -80°C. Retinas were homogenized and total protein was electrophoresed on SDS PAGE gel, transferred to nitrocellular membranes, and then probed with anti-MANF antibodies. For immunostaining, and in situ hybridization, eyes were collected, cryosectioned (12 μm). Sections were stained with anti-MANF antibodies. In situ hybridization was carried out using an RNAscope fluorescent kit with custom probe targeting MANF.
Results :
: The expression of MANF was significant from postnatal day (PD) 1 through PD16, and decline to a lower level at P25-P60. Strong immunostaining of MANF was found in Müller cells, and retinal ganglion cells (RGCs). In situ hybridization detected strong signals from RGCs and cells in the inner nuclear layer. No MANF expression was found in the outer nuclear layer.
Conclusions :
: Endogenous MANF expression was strong in the first two weeks of retinal postnatal development, and then maintains at a lower level. In situ hybridization and immunostaining localize MANF expression in cells in the inner nuclear layer and retinal ganglion cells.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.