Characterization of SHARPIN knockout Syrian hamsters developed using CRISPR/Cas9 system.

BACKGROUND

SHARPIN (SHANK-associated RH domain interactor) is a component of the linear ubiquitination complex that regulates the NF-κB signaling pathway. To better understand the function of SHARPIN, we sought to establish a novel genetically engineered Syrian hamster with SHARPIN disruption using the CRISPR/Cas9 system.

METHODS

A single-guide ribonucleic acid targeting exon 1 of SHARPIN gene was designed and constructed. The zygotes generated by cytoplasmic injection of the Cas9/gRNA ribonucleoprotein were transferred into pseudopregnant hamsters. Neonatal mutants were identified by genotyping. SHARPIN protein expression was detected using Western blotting assay. Splenic, mesenteric lymph nodes (MLNs), and thymic weights were measured, and organ coefficients were calculated. Histopathological examination of the spleen, liver, lung, small intestine, and esophagus was performed independently by a pathologist. The expression of lymphocytic markers and cytokines was evaluated using reverse transcriptase-quantitative polymerase chain reaction.

RESULTS

All the offspring harbored germline-transmitted SHARPIN mutations. Compared with wild-type hamsters, SHARPIN protein was undetectable in SHARPIN-/- hamsters. Spleen enlargement and splenic coefficient elevation were spotted in SHARPIN-/- hamsters, with the descent of MLNs and thymuses. Further, eosinophil infiltration and structural alteration in spleens, livers, lungs, small intestines, and esophagi were obvious after the deletion of SHARPIN. Notably, the expression of CD94 and CD22 was downregulated in the spleens of knockout (KO) animals. Nonetheless, the expression of CCR3, CCL11, Il4, and Il13 was upregulated in the esophagi. The expression of NF-κB and phosphorylation of NF-κB and IκB protein significantly diminished in SHARPIN-/- animals.

CONCLUSIONS

A novel SHARPIN KO hamster was successfully established using the CRISPR/Cas9 system. Abnormal development of secondary lymphoid organs and eosinophil infiltration in multiple organs reveal its potential in delineating SHARPIN function and chronic inflammation.