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The chymase, mouse mast cell protease 4, constitutes the major chymotrypsin-like activity in peritoneum and ear tissue. A role for mouse mast cell protease 4 in thrombin regulation and fibronectin turnover.

Tchougounova E, Pejler G, Abrink M - J. Exp. Med. (2003)

Bottom Line: However, mMCP-4 inactivation resulted in complete loss of chymotryptic activity in the peritoneum and in ear tissue, indicating that mMCP-4 is the main source of stored chymotrypsin-like protease activity at these sites.The mMCP-4 cells showed markedly impaired ability to perform inactivating cleavages of thrombin, indicating a role for mMCP-4 in regulating the extravascular coagulation system.Further, a role for mMCP-4 in connective tissue remodeling was suggested by the inability of mMCP-4 peritoneal cells to process endogenous fibronectin.

View Article: PubMed Central - PubMed

Affiliation: Swedish University of Agricultural Sciences, Department of Molecular Biosciences, The Biomedical Center, Box 575, 751 23 Uppsala, Sweden.

ABSTRACT
To gain insight into the biological role of mast cell chymase we have generated a mouse strain with a targeted deletion in the gene for mast cell protease 4 (mMCP-4), the mouse chymase that has the closest relationship to the human chymase in terms of tissue localization and functional properties. The inactivation of mMCP-4 did not affect the storage of other mast cell proteases and did not affect the number of mast cells or the mast cell morphology. However, mMCP-4 inactivation resulted in complete loss of chymotryptic activity in the peritoneum and in ear tissue, indicating that mMCP-4 is the main source of stored chymotrypsin-like protease activity at these sites. The mMCP-4 cells showed markedly impaired ability to perform inactivating cleavages of thrombin, indicating a role for mMCP-4 in regulating the extravascular coagulation system. Further, a role for mMCP-4 in connective tissue remodeling was suggested by the inability of mMCP-4 peritoneal cells to process endogenous fibronectin.

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Effect of the mMCP-4 targeting on MC morphology and ability to degranulate. Peritoneal cells were recovered from mMCP-4+/+ mice and from −/− or +/− littermates. Cytospin slides were prepared from unstimulated cells or after the cells had been subjected to stimulation with either calcium ionophore A23187 (2 μM) or anti-IgE antibody (4 μg/ml) for 30 min. Slides were stained May-Grünwald/Giemsa.
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fig3: Effect of the mMCP-4 targeting on MC morphology and ability to degranulate. Peritoneal cells were recovered from mMCP-4+/+ mice and from −/− or +/− littermates. Cytospin slides were prepared from unstimulated cells or after the cells had been subjected to stimulation with either calcium ionophore A23187 (2 μM) or anti-IgE antibody (4 μg/ml) for 30 min. Slides were stained May-Grünwald/Giemsa.

Mentions: The inactivation of the mMCP-4 gene did not affect the number of MCs being present in the peritoneum, with ∼2–3% of the cells in both wt and mMCP-4−/− animals being identified as MCs by staining with May-Grünwald/Giemsa. Moreover, the mMCP-4 inactivation did not lead to any noticeable effects on MC size or apparent morphology (Fig. 3) . We also investigated if the mMCP-4−/− MCs responded normally to MC-degranulating agents. Results displayed in Fig. 3 show that treatment of both wt and mMCP-4−/− MCs with either the calcium ionophore A23187 or anti-IgE antibody resulted in MC degranulation.


The chymase, mouse mast cell protease 4, constitutes the major chymotrypsin-like activity in peritoneum and ear tissue. A role for mouse mast cell protease 4 in thrombin regulation and fibronectin turnover.

Tchougounova E, Pejler G, Abrink M - J. Exp. Med. (2003)

Effect of the mMCP-4 targeting on MC morphology and ability to degranulate. Peritoneal cells were recovered from mMCP-4+/+ mice and from −/− or +/− littermates. Cytospin slides were prepared from unstimulated cells or after the cells had been subjected to stimulation with either calcium ionophore A23187 (2 μM) or anti-IgE antibody (4 μg/ml) for 30 min. Slides were stained May-Grünwald/Giemsa.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2194091&req=5

fig3: Effect of the mMCP-4 targeting on MC morphology and ability to degranulate. Peritoneal cells were recovered from mMCP-4+/+ mice and from −/− or +/− littermates. Cytospin slides were prepared from unstimulated cells or after the cells had been subjected to stimulation with either calcium ionophore A23187 (2 μM) or anti-IgE antibody (4 μg/ml) for 30 min. Slides were stained May-Grünwald/Giemsa.
Mentions: The inactivation of the mMCP-4 gene did not affect the number of MCs being present in the peritoneum, with ∼2–3% of the cells in both wt and mMCP-4−/− animals being identified as MCs by staining with May-Grünwald/Giemsa. Moreover, the mMCP-4 inactivation did not lead to any noticeable effects on MC size or apparent morphology (Fig. 3) . We also investigated if the mMCP-4−/− MCs responded normally to MC-degranulating agents. Results displayed in Fig. 3 show that treatment of both wt and mMCP-4−/− MCs with either the calcium ionophore A23187 or anti-IgE antibody resulted in MC degranulation.

Bottom Line: However, mMCP-4 inactivation resulted in complete loss of chymotryptic activity in the peritoneum and in ear tissue, indicating that mMCP-4 is the main source of stored chymotrypsin-like protease activity at these sites.The mMCP-4 cells showed markedly impaired ability to perform inactivating cleavages of thrombin, indicating a role for mMCP-4 in regulating the extravascular coagulation system.Further, a role for mMCP-4 in connective tissue remodeling was suggested by the inability of mMCP-4 peritoneal cells to process endogenous fibronectin.

View Article: PubMed Central - PubMed

Affiliation: Swedish University of Agricultural Sciences, Department of Molecular Biosciences, The Biomedical Center, Box 575, 751 23 Uppsala, Sweden.

ABSTRACT
To gain insight into the biological role of mast cell chymase we have generated a mouse strain with a targeted deletion in the gene for mast cell protease 4 (mMCP-4), the mouse chymase that has the closest relationship to the human chymase in terms of tissue localization and functional properties. The inactivation of mMCP-4 did not affect the storage of other mast cell proteases and did not affect the number of mast cells or the mast cell morphology. However, mMCP-4 inactivation resulted in complete loss of chymotryptic activity in the peritoneum and in ear tissue, indicating that mMCP-4 is the main source of stored chymotrypsin-like protease activity at these sites. The mMCP-4 cells showed markedly impaired ability to perform inactivating cleavages of thrombin, indicating a role for mMCP-4 in regulating the extravascular coagulation system. Further, a role for mMCP-4 in connective tissue remodeling was suggested by the inability of mMCP-4 peritoneal cells to process endogenous fibronectin.

Show MeSH
Related in: MedlinePlus