MAIN METHODS: Mice deficient in both dystrophin and ASC (encoded by Pycard [PYD And CARD Domain Containing]) were generated. The impact of ASC deficiency on muscular dystrophy of mdx mice were assessed by measurements of serum cytokines, Western blot, real-time PCR and histopathological staining.
KEY FINDINGS: The pro-inflammatory cytokines such as TNF-α, IL-6, KC/GRO and IL-10 were markedly increased in the sera of 8-week-old mdx mice compared to WT. Western blotting showed that P2X7, caspase-1, ASC and IL-18 were upregulated. Disruption of ASC and dystrophin expression in the mdx/ASC-/- mice was verified by Western blot analysis. Histopathological analysis did not find significant alterations in the muscular dystrophy phenotype in mdx/ASC-/- mice as compared to mdx mice.
SIGNIFICANCE: Taken together, our results show that disruption of the central adaptor ASC of the inflammasome is insufficient to alleviate muscular dystrophy phenotype in mdx mice.
METHODS: rPkMSP-119 protein was heterologously expressed using Expresso® Solubility and Expression Screening System and competent E. cloni® 10G cells according to protocol. Three rounds of biopanning were performed on purified rPkMSP-119 to identify binding peptides towards rPkMSP-119 using Ph.D.™-12 random phage display library. Binding sites of the identified peptides to PkMSP-119 were in silico predicted using the CABS-dock web server.
RESULTS: Four phage peptide variants that bound to PkMSP-119 were identified after three rounds of biopanning, namely Pkd1, Pkd2, Pkd3 and Pkd4. The sequences of both Pkd1 and Pkd2 consist of a large number of histidine residues. Pkd1 showed positive binding signal with 6.1× vs. BSA control. Docking results showed that Pkd1 and Pkd2 were ideal binding peptides for PkMSP-119 .
CONCLUSION: We identified two novel binding peptides of PkMSP-119 , Pkd1 (HFPFHHHKLRAH) and Pkd2 (HPMHMLHKRQHG), through phage display. They provide a valuable starting point for the development of novel therapeutics.