Involvement of CD44 in mast cell proliferation during terminal differentiation.
By using the recently established culture system that reproduces the terminal differentiation process of connective tissue-type mast cells, we found significant transcriptional induction of CD44. As CD44 is a primary receptor for hyaluronan (HA), which is one of the major extracellular matrix components, we investigated the role of CD44 in cutaneous mast cells. When co-cultured with fibroblasts, mouse bone marrow-derived cultured mast cells (BMMCs) were found to form clusters in an HA-dependent manner. As compared with BMMCs derived from the wild-type mice, those from the CD44(-/-) mice exhibited impaired growth during the co-cultured period. Furthermore, in the peritoneal cavities and ear tissues, mature mast cells were fewer in number in the CD44(-/-) mice than in the wild-type mice. We investigated roles of CD44 in mast cell proliferation by reconstituting BMMCs into the tissues of mast cell-deficient, Kit(W)/Kit(W-v) mice, and found that the number of metachromatic cells upon acidic toluidine blue staining in the tissues transplanted with CD44(-/-) BMMCs was not significantly changed for 10 weeks, whereas that in the tissues transplanted with the CD44(+/+) BMMCs was significantly increased. These results suggest that CD44 plays a crucial role in the regulation of the cutaneous mast cell number.
Takano
Hirotsugu
H
Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.
Nakazawa
Shunsuke
S
Shirata
Naritoshi
N
Tamba
Shigero
S
Furuta
Kazuyuki
K
Tsuchiya
Sohken
S
Morimoto
Kazushi
K
Itano
Naoki
N
Irie
Atsushi
A
Ichikawa
Atsushi
A
Kimata
Koji
K
Nakayama
Kazuhisa
K
Sugimoto
Yukihiko
Y
Tanaka
Satoshi
S
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000502:physiology; D016026:Bone Marrow Transplantation; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D003433:Crosses, Genetic; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D055879:Gene Knock-In Techniques; D018960:Hyaluronan Receptors / Q000235:genetics / Q000502:physiology*; D008297:Male; D008407:Mast Cells / Q000166:cytology* / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D012867:Skin / Q000166:cytology
D018960:Hyaluronan Receptors