Related Experiment Videos
Expression of mast-cell-specific proteases in tissues of mice studied by in situ hybridization
Abstract:
The protease mRNA expression phenotype of individual mast cells was studied by in situ hybridization. Mouse mast cell protease (MMCP)-2 mRNA was expressed by mast cells located in the mucosa of the stomach of WB(-)+/+ and (WB x C57BL/6)F1(-)+/+ (hereafter WBB6F1(-)+/+) mice but not by mast cells in the same tissue of C57BL/ 6(-)+/+ mice. Even in the stomach of WBB6F1(-)+/+ mice, mast cells located in the muscularis propria did not express MMCP-2 mRNA. The mRNAs of MMCP-4 and mouse mast cell carboxypeptidase A were not expressed by mast cells in the stomach mucosa of untreated WBB6F1(-)+/+ mice but were expressed after the infection of Strongyloides venezuelensis. We examined whether MMCP-2 mRNA expression varied by changing environments of mast cells. Cultured mast cells of WBB6F1(-)+/+ mice that expressed MMCP-2 mRNA were transplanted into the stomach wall of genetically mast-cell-deficient WBB6F1(-)W/Wv mice. Mast cells that appeared in the mucosa expressed the MMCP-2 mRNA, but mast cells that appeared in the muscularis propria did not, indicating the adaptation of cultured mast cells into a new environment. In contrast to cultured mast cells, peritoneal mast cells of WBB6F1(-)+/+ mice that expressed MMCP-2 mRNA as well did not adapt to the muscularis propria of WBB6F(1)-W/Wv mice. The MMCP-2 mRNA remained to be expressed after the settlement in either the mucosa or the muscularis propria. Furthermore, the peritoneal mast cells did not change the MMCP-4 and MMCP-6 mRNA expression phenotype after the settlement in either the mucosa or the muscularis propria of WBB6F(1)-W/Wv mice. The present result indicated that both intracellular factors such as strain specificity and source of mast cells and extracellular factors such as tissue specificity and helminth infection influenced the protease expression phenotypes.
Insights
Mast cell protease (MMCP) expression depends on both the mast cell
Area of Science:
- Immunology
- Cell Biology
- Gastroenterology
Background:
- Mast cells are immune cells involved in various physiological and pathological processes.
- The expression of mast cell proteases (MMCPs) is a key characteristic of mast cell phenotypes.
- Understanding factors influencing MMCP expression is crucial for comprehending mast cell function in different tissues and conditions.
Purpose of the Study:
- To investigate the regulation of mouse mast cell protease (MMCP)-2 mRNA expression in different mouse strains and tissue environments.
- To determine the influence of helminth infection on MMCP expression in stomach mast cells.
- To examine the adaptability of mast cells from different sources to new tissue microenvironments.
Main Methods:
- In situ hybridization was used to detect protease mRNA expression in individual mast cells.
- Experiments involved different mouse strains (WB, C57BL/6, WBB6F1, WBB6F1 W/Wv).
- Mast cells were transplanted from culture or peritoneal cavity into recipient mice, and protease mRNA expression was analyzed in various tissue locations (mucosa, muscularis propria).
Main Results:
- MMCP-2 mRNA expression in stomach mast cells varied significantly between mouse strains and was restricted to the mucosa.
- MMCP-4 and carboxypeptidase A mRNA were induced in stomach mucosa mast cells following helminth infection (Strongyloides venezuelensis).
- Cultured mast cells adapted their MMCP-2 expression based on location (mucosa vs. muscularis propria), while peritoneal mast cells did not alter their protease expression phenotype in new environments.
Conclusions:
- Mast cell protease expression phenotypes are influenced by a combination of intrinsic factors (strain, source) and extrinsic factors (tissue microenvironment, helminth infection).
- Tissue-specific adaptation of mast cell protease expression is evident for cultured mast cells but not for peritoneal mast cells.
- These findings highlight the plasticity and complexity of mast cell differentiation and function.