Proteomic profiling of early degenerative retina of RCS rats

AIM： To identify the underlying cellular and molecular changes in retinitis pigmentosa （RP）. METHODS： Label-free quantification-based proteomics analysis, with its advantages of being more economic and consisting of simpler procedures, has been used with increasing frequency in modern biological research. Dystrophic RCS rats, the first laboratory animal model for the study of RP, possess a similar pathological course as human beings with the diseases. Thus, we employed a comparative proteomics analysis approach for in-depth proteome profiling of retinas from dystrophic RCS rats and non-dystrophic congenic controls through Linear Trap Quadrupole - orbitrap MS/MS, to identify the significant differentially expressed proteins （DEPs）. Bioinformatics analyses, including Gene ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway annotation and upstream regulatory analysis, were then performed on these retina proteins. Finally, a Western blotting experiment was carried out to verify the difference in the abundance of transcript factor E2F1. RESULTS： In this study, we identified a total of 2375 protein groups from the retinal protein samples of RCS rats and non-dystrophic congenic controls. Four hundred thirty-four significantly DEPs were selected by Student＇s t-test. Based on the results of the bioinformatics analysis, we identified mitochondrial dysfunction and transcription factor E2F1 as the key initiation factors in early retinal degenerative process. CONCLUSION： We showed that the mitochondrial dysfunction and the transcription factor E2F1 substantially contribute to the disease etiology of RP. The results provide a new potential therapeutic approach for this retinal degenerative disease.

Effects of Lycii Fructus and Salviae Miltiorrhizae on the Syndrome of Deficiency with Blood Stasis in RCS(rdy-/-, p-/-) Rats with Retinitis Pigmentosa: An Intervention Study

Objective To investigate the effects of Lycii Fructus(LF,Gou Qi Zi,枸杞子)and Salviae Miltiorrhizae Radix Ex Rhizoma(SM,Dan Shen,丹参)on the syndrome of deficiency with blood stasis in the RCS(rdy-/-,p-/-)rats with retinitis pigmentosa(RP).Methods A total of 32 RCS(rdy-/-,p-/-)rats were divided into 4 groups(equal amounts of female and male rats in each group):model group treated with 0.9%normal saline,LF group treated with LF formula granules,SM group treated with SM formula granules,and LF and SM(L·S)group treated with LF and SM formula granules.Eight RCS(rdy+/+,p+/+)rats(4 males and 4 females)were treated with 0.9%normal saline to serve as blank group.The contents of E2,PG,P-Selectin,plasma viscosity,whole blood relative index of the high shear rate and fibrinogen content in plasma,and the content of cAMP and cGMP in retinal homogenate were detected.The retina was evaluated by hematoxylin-eosin staining.Results The contents of E2,PG,P-Selectin,plasma viscosity,whole blood relative index of the high shear rate,and fibrinogen content in the plasma of L·S group significantly differed from those of model group(P<0.01),but were similar to those of blank group.The contents of cAMP and cGMP in the retinal homogenate of L·S group significantly differed from those in model group(P<0.01)but were similar to those in blank group(P>0.05).Conclusions LF and SM can effectively treat retinitis pigmentosa by ameliorating the syndrome of deficiency with blood stasis.

AB011.A collagen-alginate-based cell-encapsulation intraocular implant for retinal disease therapy

Encapsulated-cell therapy (ECT) is an attractive approach for continuously delivering freshly synthesized therapeutics to treat sight-threatening posterior eye diseases, circumventing repeated invasive intravitreal injections and improving local drug availability clinically. Composite collagen-alginate (CAC) scaffold in ECT contains an interpenetrating network that integrates the physical and biological merits of its constituents, including biocompatibility, mild gelling properties and availability. An injectable CAC system that supported the growth of HEK293 cells with sustainable glial-derived neurotrophic factor (GDNF) delivery has been developed. Continuous GDNF delivery was detected in culture and in healthy rat eyes for at least 14 days. The gels were well tolerated with no host tissue attachment and contained living cell colonies. Most importantly, gel implantation in dystrophic Royal College of Surgeons rat eyes for 28 days retained photoreceptors while those gels containing higher initial cell number yielded better photoreceptor rescue effect. This rescue effect is clinically relevant as photoreceptor death is a common pathology in many retinal diseases. Moreover, since cells including autologous cells can be genetically engineered to secrete various therapeutic agents, CAC gel offers a flexible system design and is a potential treatment option for other chronic neurodegenerative diseases.