Objective: Interaction of c-Kit and its ligand stem cell factor (SCF) is necessary for appropriate development and survival of interstitial cells of Cajal (ICC) in the intestine. Blockade of c-Kit will cause ICC loss in vivo. Stem cell leukemia (SCL) gene acts as a positive regulator of upstream transcription of c-Kit expression. This study aimed to explore whether the restoration of c-Kit expression promoted by SCL gene transfer could rescue ICC in vivo.
Materials and methods: A modified ICC-loss mouse model was created by continual administration of anti-c-Kit antibody (ACK2) to obtain a steady status of ICC loss, and a recombinant adenovirus vector containing SCL gene (Ad-SCL) was designed to rescue ICC in these mice. Western blot analysis and immunofluorescence labeling assays were performed to analyze the SCL and c-Kit expression in vitro and in vivo. The distribution and configuration of ICC were observed with immunohistochemistry and electromicroscope.
Results: Western blot analysis and immunofluorescence labeling assays showed that SCL gene was successfully delivered to cultured HeLa and ICC cells in vitro. Moreover, significantly increased c-Kit expression could be detected in the colon of Ad-SCL-infected ICC-loss mice. Furthermore, rescue of the ICC network and ICC with typical ultrastructural features could be detected in Ad-SCL-infected ICC-loss mice at day 37.
Conclusions: Ad-SCL was able to enhance c-Kit expression, reactivate the c-Kit/SCF pathway, and rescue ICC in ICC-loss mice. Since loss and defects of ICC are associated with many human gut motility disorders, Ad-SCL may be of potential use in gene therapy of these patients.