In October 5th, 2018, the research work of Prof. Jun Wang's group was published online in Nature Communications entitled Targeting of NLRP3 Inflammasome with Gene Editing for the Amelioration of Inflammatory Diseases. The correspondence author is Prof. Jun Wang, who is the dean of School of Biomedical Science and Engineering in Guangzhou International Campus. The co-first authors are Dr. Congfei Xu and Dr. Zidong Lu, and the first affiliation is South China University of Technology. The research work was supported by the National Key R&D Program of China (2017YFA0205600), the Program for Guangdong Introducing Innovative and Enterpreneurial Teams (2017ZT07S054), the National Natural Science Foundation of China etc.
CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/ CRISPR-associated protein 9), is a microbial adaptive immune system that uses RNA-guided nucleases to cleave foreign genetic elements. In the CRISPR-Cas system derived from Streptococcus pyogenes, the Cas9 nuclease cuts specific DNA targets (immediately precede a 5′-NGG PAM) with gRNA recognition, and facilitates efficient genome engineering by non-homologous end joining (NHEJ) or homologous recombination (HR). Up to now, CRISPR/Cas9-based gene therapies have been tested in clinical trials for a variety of single /multiple gene-mutated diseases, tumors, and viral infectious diseases. More than 20 CRISPR/Cas9-related clinical trials are underway. However, how to efficiently deliver CRISPR/Cas9 into target cells in vivo for gene editing is still an urgent problem to be solved.
Prof. Jun Wang’s group developed a delivery system named as cationic lipid-assisted polymeric nanoparticles (CLAN), which is based on the FDA-approved polymer PEG-PLA or PEG-PLGA and assisted by cationic lipid BHEM-Chol. In their previous work, they have successfully delivered small interfering RNA, RNA aptamer and hepatitis B virus CpG into tumor cells, cardiomyocytes, macrophages or plasmacytoid dendritic cells with CLAN. However, CRISPR/Cas9 is quite different from other nucleic acid therapeutics and the properties of nanoparticles significantly impact the efficiency of drug delivery. Therefore, Jun’s group created a library of CLAN with different surface zeta potential and PEG density. They screened CLANs both in vitro and in vivo and selected a preferable CLAN for delivering Cas9 mRNA and NLRP3-targeting gRNA into macrophages, which effectively inhibited the activation of NLRP3 inflammasome in mice and mitigated LPS-induced septic shock, monosodium urate crystals (MSU)-induced peritonitis and high fat diet (HFD)-induced T2D by disrupting NLRP3 in macrophages.
Their work provided a good strategy for delivery of CRISPR/Cas9 into macrophages and treatment of multiple inflammatory diseases. In addition, they are working on follow-up improvements to CLAN for delivering CLAN into more kinds of cells in vivo.
