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Bone morphogenetic protein 4 inhibits insulin secretion from rodent beta cells through regulation of calbindin1 expression and reduced voltage-dependent calcium currents

Christensen, Gitte L.; Jacobsen, Maria L. B.; Wendt, Anna LU ; Mollet, Ines LU ; Friberg, Josefine; Frederiksen, Klaus S.; Meyer, Michael; Bruun, Christine; Eliasson, Lena LU and Billestrup, Nils (2015) In Diabetologia 58(6). p.1282-1290
Abstract
Aims/hypothesis Type 2 diabetes is characterised by progressive loss of pancreatic beta cell mass and function. Therefore, it is of therapeutic interest to identify factors with the potential to improve beta cell proliferation and insulin secretion. Bone morphogenetic protein 4 (BMP4) expression is increased in diabetic animals and BMP4 reduces glucose-stimulated insulin secretion (GSIS). Here, we investigate the molecular mechanism behind this inhibition. Methods BMP4-mediated inhibition of GSIS was investigated in detail using single cell electrophysiological measurements and live cell Ca2+ imaging. BMP4-mediated gene expression changes were investigated by microarray profiling, quantitative PCR and western blotting. Results Prolonged... (More)
Aims/hypothesis Type 2 diabetes is characterised by progressive loss of pancreatic beta cell mass and function. Therefore, it is of therapeutic interest to identify factors with the potential to improve beta cell proliferation and insulin secretion. Bone morphogenetic protein 4 (BMP4) expression is increased in diabetic animals and BMP4 reduces glucose-stimulated insulin secretion (GSIS). Here, we investigate the molecular mechanism behind this inhibition. Methods BMP4-mediated inhibition of GSIS was investigated in detail using single cell electrophysiological measurements and live cell Ca2+ imaging. BMP4-mediated gene expression changes were investigated by microarray profiling, quantitative PCR and western blotting. Results Prolonged exposure to BMP4 reduced GSIS from rodent pancreatic islets. This inhibition was associated with decreased exocytosis due to a reduced Ca2+ current through voltage-dependent Ca2+ channels. To identify proteins involved in the inhibition of GSIS, we investigated global gene expression changes induced by BMP4 in neonatal rat pancreatic islets. Expression of the Ca2+-binding protein calbindin1 was significantly induced by BMP4. Overexpression of calbindin1 in primary islet cells reduced GSIS, and the effect of BMP4 on GSIS was lost in islets from calbindin1 (Calb1) knockout mice. Conclusions/interpretation We found BMP4 treatment to markedly inhibit GSIS from rodent pancreatic islets in a calbindin1-dependent manner. Calbindin1 is suggested to mediate the effect of BMP4 by buffering Ca2+ and decreasing Ca2+ channel activity, resulting in diminished insulin exocytosis. Both BMP4 and calbindin1 are potential pharmacological targets for the treatment of beta cell dysfunction. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Beta cells, BMP4, Calb1, Calbindin1, Diabetes, Exocytosis, Insulin, secretion
in
Diabetologia
volume
58
issue
6
pages
1282 - 1290
publisher
Springer Verlag
external identifiers
  • wos:000353893000018
  • scopus:84937764635
ISSN
1432-0428
DOI
10.1007/s00125-015-3568-x
language
English
LU publication?
yes
id
2b0440a1-7bb4-4ddc-adeb-0e5a318b32bb (old id 7425041)
date added to LUP
2015-07-03 07:06:06
date last changed
2017-11-12 03:04:31
@article{2b0440a1-7bb4-4ddc-adeb-0e5a318b32bb,
  abstract     = {Aims/hypothesis Type 2 diabetes is characterised by progressive loss of pancreatic beta cell mass and function. Therefore, it is of therapeutic interest to identify factors with the potential to improve beta cell proliferation and insulin secretion. Bone morphogenetic protein 4 (BMP4) expression is increased in diabetic animals and BMP4 reduces glucose-stimulated insulin secretion (GSIS). Here, we investigate the molecular mechanism behind this inhibition. Methods BMP4-mediated inhibition of GSIS was investigated in detail using single cell electrophysiological measurements and live cell Ca2+ imaging. BMP4-mediated gene expression changes were investigated by microarray profiling, quantitative PCR and western blotting. Results Prolonged exposure to BMP4 reduced GSIS from rodent pancreatic islets. This inhibition was associated with decreased exocytosis due to a reduced Ca2+ current through voltage-dependent Ca2+ channels. To identify proteins involved in the inhibition of GSIS, we investigated global gene expression changes induced by BMP4 in neonatal rat pancreatic islets. Expression of the Ca2+-binding protein calbindin1 was significantly induced by BMP4. Overexpression of calbindin1 in primary islet cells reduced GSIS, and the effect of BMP4 on GSIS was lost in islets from calbindin1 (Calb1) knockout mice. Conclusions/interpretation We found BMP4 treatment to markedly inhibit GSIS from rodent pancreatic islets in a calbindin1-dependent manner. Calbindin1 is suggested to mediate the effect of BMP4 by buffering Ca2+ and decreasing Ca2+ channel activity, resulting in diminished insulin exocytosis. Both BMP4 and calbindin1 are potential pharmacological targets for the treatment of beta cell dysfunction.},
  author       = {Christensen, Gitte L. and Jacobsen, Maria L. B. and Wendt, Anna and Mollet, Ines and Friberg, Josefine and Frederiksen, Klaus S. and Meyer, Michael and Bruun, Christine and Eliasson, Lena and Billestrup, Nils},
  issn         = {1432-0428},
  keyword      = {Beta cells,BMP4,Calb1,Calbindin1,Diabetes,Exocytosis,Insulin,secretion},
  language     = {eng},
  number       = {6},
  pages        = {1282--1290},
  publisher    = {Springer Verlag},
  series       = {Diabetologia},
  title        = {Bone morphogenetic protein 4 inhibits insulin secretion from rodent beta cells through regulation of calbindin1 expression and reduced voltage-dependent calcium currents},
  url          = {http://dx.doi.org/10.1007/s00125-015-3568-x},
  volume       = {58},
  year         = {2015},
}