title: Role of Src Family Kinases in Regulation of Intestinal Epithelial Homeostasis.
abstract: Proper regulation of epithelial cell turnover is important for the structural integrity and homeostasis of various tissues, including the intestine. Here we show that ablation of Csk, a negative regulator of Src family kinases (SFKs), specifically in intestinal epithelial cells (IECs) resulted in the development of hyperplasia throughout the intestinal epithelium of mice. Such conditional ablation of Csk also increased the proliferative activity and turnover of IECs, disturbed the differentiation of Paneth and goblet cells, reduced the number of intestinal stem cells, and attenuated the expression of Wnt target genes in the intestine. Moreover, the tyrosine phosphorylation of focal adhesion kinase (FAK) and the activities of both Rac and Yes-associated protein (YAP) were increased in intestinal crypts or organoids of the mutant mice, whereas inhibition of Rac or YAP activity rescued the mutant phenotypes. Our results thus suggest that SFKs promote the proliferation of IECs in intestinal crypts through activation of Rac or YAP and that they thereby contribute to the proper regulation of IEC turnover and intestinal homeostasis.
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.|Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Imada
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan ymurata@med.kobe-u.ac.jp matozaki@med.kobe-u.ac.jp.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Murata
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Takenori
authors.initials: T
authors.lastname: Kotani
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Hatano
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Sun
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Tasuku
authors.initials: T
authors.lastname: Konno
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Jung-Ha
authors.initials: JH
authors.lastname: Park
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Kitamura
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ohdan
authors.affiliation: Division of Molecular and Cellular Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan ymurata@med.kobe-u.ac.jp matozaki@med.kobe-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Matozaki