Inhibition of the antigen-induced activation of rodent mast cells by putative Janus kinase 3 inhibitors WHI-P131 and WHI-P154 in a Janus kinase 3-independent manner.
We analyzed the effects of the Janus kinase 3 (Jak3)-specific inhibitor WHI-P131 (4-(4'-hydroxyphenyl)-amino-6,7-dimethoxyquinazoline) and the Jak3/Syk inhibitor WHI-P154 (4-(3'-bromo-4'-hydroxyphenyl)-amino-6,7-dimethoxyquinazoline) on the antigen-induced activation of mast cells. In the rat mast cell line RBL-2H3, both WHI-P131 and WHI-P154 inhibited the antigen-induced degranulation and phosphorylation of p44/42 mitogen-activated protein kinase (MAPK), p38 MAPK and c-Jun N-terminal kinase (JNK). The phosphorylation of Gab2, Akt and Vav was also inhibited by WHI-P131 and WHI-P154, indicating that these inhibitors suppress the activation of phosphatidylinositol 3-kinase (PI3K). In bone marrow-derived mast cells (BMMCs) from Jak3-deficient (Jak3-/-) mice, degranulation and activation of MAPKs were induced by the antigen in almost the same extent as in BMMCs from wild-type mice. In addition, the antigen-induced degranulation and activation of MAPKs were inhibited by WHI-P131 and WHI-P154 in both groups of BMMCs, indicating that these compounds inhibit a certain step except for Jak3. The antigen-induced increase in the activity of Fyn, a probable tyrosine kinase of Gab2, was also inhibited by WHI-P131 and WHI-P154 in RBL-2H3 cells. In BMMCs from Jak3-/- mice, the antigen stimulation induced tyrosine phosphorylation of Fyn, which was inhibited by WHI-P131, as well as in BMMCs from wild-type mice and in RBL-2H3 cells. These findings suggest that Jak3 does not play a significant role in the antigen-induced degranulation and phosphorylation of MAPKs, and that WHI-P131 and WHI-P154 inhibit the PI3K pathway by preventing the antigen-induced activation of Fyn, thus inhibiting the antigen-induced degranulation and phosphorylation of MAPKs in mast cells.
Linwong
Watchara
W
Laboratory of Pathophysiological Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
Hirasawa
Noriyasu
N
Aoyama
Suzue
S
Hamada
Hirofumi
H
Saito
Takashi
T
Ohuchi
Kazuo
K
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism; D015550:Cell Degranulation / Q000187:drug effects; D045744:Cell Line, Tumor; D004140:Dinitrophenols / Q000494:pharmacology; D006596:Hexosaminidases / Q000378:metabolism; D007073:Immunoglobulin E / Q000494:pharmacology; D053616:Janus Kinase 3; D008407:Mast Cells / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000172:deficiency / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D051076:Proto-Oncogene Proteins c-fyn; D051567:Proto-Oncogene Proteins c-vav; D011799:Quinazolines / Q000494:pharmacology*; D051381:Rats; D012709:Serum Albumin / Q000494:pharmacology; D019061:src-Family Kinases / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D004140:Dinitrophenols; D006596:Hexosaminidases; D007073:Immunoglobulin E; D053616:Janus Kinase 3; D020928:Mitogen-Activated Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D051076:Proto-Oncogene Proteins c-fyn; D051567:Proto-Oncogene Proteins c-vav; D011799:Quinazolines; D012709:Serum Albumin; D019061:src-Family Kinases; C490893:Gab2 protein, rat; C507936:Jak3 protein, rat; C496619:Vav1 protein, mouse; C496620:Vav1 protein, rat; C116180:WHI P131; C113888:WHI P154; C058064:dinitrophenyl-human serum albumin conjugate; C494960:Fyn protein, mouse; C494961:Fyn protein, rat; C507933:JAK3 protein, human; C507935:Jak3 protein, mouse; C494920:Akt1 protein, rat