The Effect Of Shadoo Depletion By Knockout On Prion Replication And Pathopoiesis

Prion diseases also called Ttransmissible spongiform encephalopathies is a fatal,neurodegenerative disease.Normal prion protein PrP^Cexist in the healthy animals,asPrP^Sc, which is thought to be converted from PrP^C,in the diseased animals.We have found a new membrane protein named Shadoo protein in genedatabase by comparative genomics, which comprises the third PrP^C-like proteinidentified thus far in higher mammals. Sprn, the gene sequence of Shadoo protein isalways conservative from fish to mammal. Indeed, scrutiny of Shadoo’s biochemicalproperties in uninfected cells has revealed overlaps with the properties of PrP^C. Inrodent models of prion disease there are reduced levels of Shadoo in infected tissues,defining a form of cross-regulation between full-length Shadoo holoprotein andPrP^Sc. Some study found that from PrP^Cto PrP^Sctransfrom need a "pi" protein as abridge. We assumed that Shadoo is pi,and have established the Shadoo proteinknockout mice. We have inoculated with mouse-adapted22L and RML scrapie toresearch the effect of Shadoo protein knochout on Prion replication and pathopoiesis.The study were composed by two parts：1. The construct and identify of Shadookonckout mice lines.1) Establishment of Sprn-/+mice.2) Screening Sprn^-/-mice byPCR.3) Identify Sprn^-/-mice by Western Blot.4) Identify Sprn^-/-mice byimmunohistochemical.2. The pathogenesis of Sprn^-/-mice inoculated withmouse-adapted22L and RML scrapie.1) Sprn^-/-mice and wild type mice inoculatedwith mouse-adapted22L and RML scrapie.2) Regular feeding,record the clinicalsymptoms and body weight change.3) Detection the brain pathological lesions inwild-type mice and Sprn^-/-mice.4) Detection the PrP^Scdepositions in brain andspleen of wild-tpye mice and Sprn^-/-mice.5) Detection exuberant reactiveastrogiliosis in brain of wild-type mice and Sprn^-/-mice.6) Compare with thesurvival time and the survival rate of wild-type mice and Sprn^-/-mice afterinoculated with22L and RML scraoie.In conclusion,1) This study has successfully established Sprn^-/-mice line, andsuccessfully inheritance to the next generation according to Mendelian.2) It has the same trend of body weight of wild-tpye mice and Sprn^-/-mice, but the body weightof Sprn^-/-mice is higher than wild-tpye mice.3) There is no significant differences inthe brain pathological lesions of wild-type mice and Sprn^-/-mice.4) There is nosignificant differences in astrogliosis of wild-type mice and Sprn^-/-mice.5) ThePrP^Scdeposition in the brain and spleen of Sprn^-/-mice is more significantly thanwild-type mice.6) Shadoo depletion did not change the survival time and thesurvival rate of Sprn^-/-mice after inoculated with22L and RML scrapie.