[Liposome-mediated gene transfer into retina].
OBJECTIVE
To evaluate the efficiency of liposome mediated gene transfer to retina, the time of gene expression in retinal cells, retinal damage caused by liposome and the possibility of using liposome mediated gene transfer to retina for treating fundus diseases.


METHODS
The ratio of cationic liposome to green fluorescein protein (GFP) expression plasmid for high efficacy of transfection was tested in vitro. Then optimal liposome-plasmid mixture was injected into the subretinal space of Sprague-Dawley (SD) or Royal college of surgeon (RCS) rats. The GFP expression was observed by using fluorescence microscopy, and morphological changes were examined by using paraffin embedded sections, HE staining and transmission electron microscopy.


RESULTS
The GFP expression in retinal cells was observed lasting more than 4 weeks. However, upon 4 weeks of transfection the swelling and degeneration in outer segment of photoreceptors could be observed. The aggravated degeneration with disappearance of outer segments, only one layer of photoreceptor nucleus surviving, apoptotic inner granular layer cells and neovascularization were observed 8 weeks after transfection. But no inflammatory cells were observed. Three of 5 RCS rats that received plasmid pCNTF (ciliary neurotrophic factor) delivery at 4 weeks old showed more surviving nuclei of photoreceptors after 3 to 5 weeks of transfection.


CONCLUSIONS
Liposome is able to deliver genes to retinal cells with efficacy, and the expression of therapeutic gene such as CNTF in retinal cells can rescue photoreceptors from degeneration. But liposome used here is to some extent harmful to photoreceptors.
Wang
Feng
F
Central Experimental Laboratory, The First People's Hospital of Shanghai, Shanghai 200080, China.
Xia
Xin
X
Hu
Honghui
H
Li
Ling
L
Tian
Yuhua
Y
Chen
Xiafang
X
Huang
Qian
Q
D000818:Animals; D020934:Ciliary Neurotrophic Factor / Q000235:genetics / Q000378:metabolism; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins; D008081:Liposomes; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D010957:Plasmids / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure
D020934:Ciliary Neurotrophic Factor; D008081:Liposomes; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins