Pyroptosis as a candidate therapeutic target for Alzheimer's disease.

Pyroptosis is a form of cell death mediated by inflammasomes and gasdermins, and the relevance of pyroptosis to neurodegenerative diseases is currently receiving increasing attention. Alzheimer's disease (AD) is a chronic progressive neurodegenerative disease that is closely associated with neuroinflammation. Its main pathological features include ß-amyloid (Aß) deposition, Tau protein hyperphosphorylation and neuronal loss. Aß, tau-induced microglia pyroptosis and polarization leading to neuroinflammation play an important role in the pathogenesis of AD. Studying the pathogenesis and treatment of AD based on cellular pyroptosis has become a new direction in AD research. In this paper, we review the research progress of pyroptosis and will focus on the pathogenic roles of pyroptosis in AD and the role of targeted inhibition of inflammasome-dependent pyroptosis in AD treatment. These results deepen our understanding of the pathogenesis of AD and provide ideas for the development of new drugs based on the regulation of pyroptosis in AD patients.

[Determination of the in vitro antiviral activity of an engineered M1GS ribozyme that targets to the core gene of hepatitis C virus].

OBJECTIVE: Hepatitis C virus (HCV) is one of the major pathogens that lead to viral hepatitis. At present, Interferon treatment in combination with ribavirin is the first line clinical therapeutic approach. However, the responses are usually poor and the viral infection reoccurs. Therefore, exploring new antiviral agents and therapies is under urgent needs. METHODS: The sequence and structure of the core coding region of HCV genome were analyzed through the two computer software, DNAMAN and RNA Structure. The cytosine 52 nt downstream of the AUG initiation triplet was identified as the optimal target cleavage site. Based on the flanking sequence of this assumed cleavage site, a guide sequence (GS) was designed and covalently linked to the 3 prime terminus of the M1 RNA, which is catalytic subunit of the RNase P derived from Escherichia coli using PCR. We named this new targeting ribozyme M1GS-HCV/C52 and it antiviral activities were analyzed in cultured cells. RESULTS: In the in vitro cleavage assay, M1GS-HCV/C52 ribozyme could effectively cleave the HCV target RNA into two fragments at the specific cleavage site. Moreover, comparing to the blank control, this engineered M1GS ribozyme could reduce the core protein expression of more than 80% in the HCV-infected host cell and lead to a 1500-fold reduction of HCV RNA copies in the culture supernatant. An another M1GS ribozyme, M1GS-HCV/C52*, which has the same guide sequence but does not contain a 24nt-long bridge sequence, did not exhibit apparent inhibition for the expression of HCV core gene and viral proliferation in our paralleled assay. CONCLUSION: We successfully constructed an M1GS ribozyme showing affective and specific cleavage of target viral RNA. Further results showed that the engineering ribozyme had notably antiviral activity in cultured cells, thus provided a new promising approach for clinical anti-HCV therapeutic strategy.

[Construction of an engineered M1GS-HCV/C141 ribozyme and determination of its antiviral activity in vitro].

Hepatitis C virus (HCV), one of the major pathogens of viral hepatitis, causes significant hazards in humans. Interferon treatment in combination with ribavirin is used as the first line clinical treatment for HCV infection. However, good response to this treatment has only been observed in few patients and repeated recurrence has also been reported frequently. Therefore, new antiviral agents and therapies are in urgent demand. Here, we report a newly constructed Escherichia coli RNase P based M1GS ribozyme that can specifically and efficiently target the core gene of HCV. The guide sequence (GS) of this M1IGS was designed according to the sequence of the core coding region of HCV genome. The GS was then covalently linked to the 3' terminus of M1 RNA, the catalytic subunit of RNase P from Escherichia coli. The specification of this sequence-specific ribozyme, M1GS, was then examined using an in vitro cleavage assay. The cytotoxicity and its activity in inhibition of HCV gene expression and viral proliferation were further studied in vivo. Our results show that the reconstructed M1GS ribozyme displayed obvious catalytic activity in cleaving target mRNAs fragment in vitro. Notable reduction in the expression of HCV core protein and a 1 000-fold reduction in viral growth were also observed in cultured HCV infected Huh7.5.1 cells expressing the functional M1GS ribozyme. This study demonstrated a direct evidence for the antiviral activity of the customized M1GS-HCV/C141 ribozyme, and thus provided a promising new strategy for clinical treatment of HCV infection.