tailieunhanh - Báo cáo khoa học: The propagation of hamster-adapted scrapie PrPSc can be enhanced by reduced pyridine nucleotide in vitro

Transmissible spongiform encephalopathies (TSEs), or prion diseases, are fatal neurodegenerative disorders caused by an infectious agent termed a prion, which can convert normal cellular prion protein (PrP C ) into a patho-logically misfolded isoform (PrP Sc ). Taking advantage of protein misfolding cyclic amplification (PMCA), a series of experiments was conducted to investigate the possible influences of pyridine nucleotides on the propaga- | The propagation of hamster-adapted scrapie PrPSc can be enhanced by reduced pyridine nucleotide in vitro Song Shi Chen-Fang Dong Chan Tian Rui-Min Zhou Kun Xu Bao-Yun Zhang Chen Gao Jun Han and Xiao-Ping Dong State Key Laboratory for Infectious Disease Prevention and Control National institute for ViralDisease Controland Prevention Beijing China Keywords PMCA prion propagation pyridine nucleotide transmissible spongiform encephalopathies Correspondence . Dong State Key Laboratory for Infectious Disease Prevention and Control National institute for ViralDisease Control and Prevention Chinese Center for Disease Controland Prevention Ying-Xin Rd 100 Beijing 100052 China Fax 86 10 63532053 Tel 86 10 83534616 E-mail dongxp238@ Received 16 September 2008 revised 15 November 2008 accepted 22 December 2008 doi Transmissible spongiform encephalopathies TSEs or prion diseases are fatal neurodegenerative disorders caused by an infectious agent termed a prion which can convert normal cellular prion protein PrPC into a pathologically misfolded isoform PrPSc . Taking advantage of protein misfolding cyclic amplification PMCA a series of experiments was conducted to investigate the possible influences of pyridine nucleotides on the propagation activities of hamster-adapted scrapie agents 263K and 139A in vitro using normal hamster brain homogenates and recombinant hamster PrP as the substrates. The results showed that PrPSc from both scrapie agent 263K- and 139A-infected brains propagated more efficiently in PMCA with the addition of reduced NADPH showing an obvious dose-dependent enhancement. Reduced NADH also prompted PrPSc propagation whereas NADP NAD and vitamin C failed. Moreover following incubation with NADPH recombinant hamster PrP could be efficiently converted into the proteinase K-resistant form when exposed to the trace of PrPSc from infected hamsters. Our data provide evidence that the reduced pyridine nucleotide plays an .