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Generation and analysis of serine protease inhibitor kazal type 3-cre driver mice
Kazuya Sakata1, Masaki Ohmuraya, Kimi Araki
1Institute of Resource Development and Analysis, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan.
Abstract:
Serine protease inhibitor Kazal type 1 (SPINK1; mouse homologue Spink3) was initially discovered as a trypsin-specific inhibitor in the pancreas. However, previous studies have suggested that SPINK1/Spink3 is expressed in a wide range of normal tissues and tumors, although precise characterization of its gene expression has not been described in adulthood. To further analyze Spink3 expression, we generated two mouse lines in which either lacZ or Cre recombinase genes were inserted into the Spink3 locus by Cre-loxP technology. In Spink3(lacZ) mice, β-galactosidase activity was found in acinar cells of the pancreas and kidney, as well as epithelial cells of the bronchus in the lung, but not in the gastrointestinal tract or liver. Spink3(cre) knock-in mice were crossed with Rosa26 reporter (R26R) mice to monitor Spink3 promoter activity. In Spink3(cre);R26R mice, β-galactosidase activity was found in acinar cells of the pancreas, kidney, lung, and a small proportion of cells in the gastrointestinal tract and liver. These data suggest that Spink3 is widely expressed in endoderm-derived tissues, and that Spink3(cre) knock-in mice are a useful tool for establishment of a conditional knockout mice to analyze Spink3 function not only in normal tissues, but also in tumors that express SPINK1/Spink3.
Insights
Serine protease inhibitor Kazal type 1 (SPINK1) and its mouse homologue Spink3 show broad expression in adult endoderm-derived tissues. Spink3-reporter mice are valuable tools for studying SPINK1/Spink3 functions in health and disease.
Area of Science:
- Biochemistry
- Genetics
- Molecular Biology
Background:
- Serine protease inhibitor Kazal type 1 (SPINK1) is a trypsin-specific inhibitor initially found in the pancreas.
- Previous studies indicated SPINK1/Spink3 expression in various normal tissues and tumors, but detailed adult gene expression patterns were lacking.
Purpose of the Study:
- To precisely characterize the gene expression of Spink3 in adult mice.
- To develop Spink3-reporter mouse models for functional studies.
Main Methods:
- Generation of Spink3(lacZ) and Spink3(cre) knock-in mouse lines using Cre-loxP technology.
- Analysis of β-galactosidase activity in Spink3(lacZ) mice to determine Spink3 expression sites.
- Crossing Spink3(cre) mice with Rosa26 reporter (R26R) mice to visualize Spink3 promoter activity.
Main Results:
- Spink3 expression was detected in pancreatic acinar cells, kidney, and lung bronchus epithelial cells in Spink3(lacZ) mice.
- Spink3 promoter activity was observed in pancreatic acinar cells, kidney, lung, and scattered cells in the gastrointestinal tract and liver of Spink3(cre);R26R mice.
- These findings indicate widespread Spink3 expression in endoderm-derived tissues.
Conclusions:
- Spink3 is broadly expressed across multiple endoderm-derived tissues in adult mice.
- The generated Spink3(cre) knock-in mice serve as a valuable tool for creating conditional knockout models.
- These models will facilitate the analysis of Spink3 function in both normal physiological conditions and tumor development.
