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Rac1 regulates pancreatic islet morphogenesis.

Greiner, Thomas LU ; Kesavan, Gokul LU ; Ståhlberg, Anders and Semb, Henrik LU (2009) In BMC Developmental Biology 9:2.
Abstract
BACKGROUND: Pancreatic islets of Langerhans originate from endocrine progenitors within the pancreatic ductal epithelium. Concomitant with differentiation of these progenitors into hormone-producing cells such cells delaminate, aggregate and migrate away from the ductal epithelium. The cellular and molecular mechanisms regulating islet cell delamination and cell migration are poorly understood. Extensive biochemical and cell biological studies using cultured cells demonstrated that Rac1, a member of the Rho family of small GTPases, acts as a key regulator of cell migration. RESULTS: To address the functional role of Rac1 in islet morphogenesis, we generated transgenic mice expressing dominant negative Rac1 under regulation of the Rat... (More)
BACKGROUND: Pancreatic islets of Langerhans originate from endocrine progenitors within the pancreatic ductal epithelium. Concomitant with differentiation of these progenitors into hormone-producing cells such cells delaminate, aggregate and migrate away from the ductal epithelium. The cellular and molecular mechanisms regulating islet cell delamination and cell migration are poorly understood. Extensive biochemical and cell biological studies using cultured cells demonstrated that Rac1, a member of the Rho family of small GTPases, acts as a key regulator of cell migration. RESULTS: To address the functional role of Rac1 in islet morphogenesis, we generated transgenic mice expressing dominant negative Rac1 under regulation of the Rat Insulin Promoter. Blocking Rac1 function in beta cells inhibited their migration away from the ductal epithelium in vivo. Consistently, transgenic islet cell spreading was compromised in vitro. We also show that the EGF-receptor ligand betacellulin induced actin remodelling and cell spreading in wild-type islets, but not in transgenic islets. Finally, we demonstrate that cell-cell contact E-cadherin increased as a consequence of blocking Rac1 activity. CONCLUSION: Our data support a model where Rac1 signalling controls islet cell migration by modulating E-cadherin-mediated cell-cell adhesion. Furthermore, in vitro experiments show that betacellulin stimulated islet cell spreading and actin remodelling is compromised in transgenic islets, suggesting that betacellulin may act as a regulator of Rac1 activity and islet migration in vivo. Our results further emphasize Rac1 as a key regulator of cell migration and cell adhesion during tissue and organ morphogenesis. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
BMC Developmental Biology
volume
9:2
publisher
BioMed Central
external identifiers
  • wos:000263052400001
  • pmid:19126201
  • scopus:59649089873
ISSN
1471-213X
DOI
10.1186/1471-213X-9-2
language
English
LU publication?
yes
id
ec5438ae-4e3f-4b93-b01f-86e9d0545faa (old id 1289902)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/19126201?dopt=Abstract
date added to LUP
2009-02-03 10:20:21
date last changed
2017-08-27 05:52:46
@article{ec5438ae-4e3f-4b93-b01f-86e9d0545faa,
  abstract     = {BACKGROUND: Pancreatic islets of Langerhans originate from endocrine progenitors within the pancreatic ductal epithelium. Concomitant with differentiation of these progenitors into hormone-producing cells such cells delaminate, aggregate and migrate away from the ductal epithelium. The cellular and molecular mechanisms regulating islet cell delamination and cell migration are poorly understood. Extensive biochemical and cell biological studies using cultured cells demonstrated that Rac1, a member of the Rho family of small GTPases, acts as a key regulator of cell migration. RESULTS: To address the functional role of Rac1 in islet morphogenesis, we generated transgenic mice expressing dominant negative Rac1 under regulation of the Rat Insulin Promoter. Blocking Rac1 function in beta cells inhibited their migration away from the ductal epithelium in vivo. Consistently, transgenic islet cell spreading was compromised in vitro. We also show that the EGF-receptor ligand betacellulin induced actin remodelling and cell spreading in wild-type islets, but not in transgenic islets. Finally, we demonstrate that cell-cell contact E-cadherin increased as a consequence of blocking Rac1 activity. CONCLUSION: Our data support a model where Rac1 signalling controls islet cell migration by modulating E-cadherin-mediated cell-cell adhesion. Furthermore, in vitro experiments show that betacellulin stimulated islet cell spreading and actin remodelling is compromised in transgenic islets, suggesting that betacellulin may act as a regulator of Rac1 activity and islet migration in vivo. Our results further emphasize Rac1 as a key regulator of cell migration and cell adhesion during tissue and organ morphogenesis.},
  author       = {Greiner, Thomas and Kesavan, Gokul and Ståhlberg, Anders and Semb, Henrik},
  issn         = {1471-213X},
  language     = {eng},
  month        = {01},
  publisher    = {BioMed Central},
  series       = {BMC Developmental Biology},
  title        = {Rac1 regulates pancreatic islet morphogenesis.},
  url          = {http://dx.doi.org/10.1186/1471-213X-9-2},
  volume       = {9:2},
  year         = {2009},
}