Ins1 gene up-regulated in a beta-cell line derived from Ins2 knockout mice.
The authors have derived a new beta-cell line (betaIns2(-/-lacZ)) from Ins2-/- mice that carry the lacZ reporter gene under control of the Ins2 promoter. betaIns2(-/-lacZ) cells stained positively using anti-insulin antibody, expressed beta-cell-specific genes encoding the transcription factor PDX-1, glucokinase, and Glut-2, retained glucose-responsiveness for insulin secretion, and expressed the lacZ gene. Analysis of Ins1 expression by reverse transcriptase-polymerase chain reaction (RT-PCR) showed that Ins1 transcripts were significantly raised to compensate for the lack of Ins2 transcripts in betaIns2(-/-lacZ) cells, as compared to those found in betaTC1 cells expressing both Ins1/Ins2. Thus, transcriptional up-regulation of the remaining functional insulin gene in Ins2-/- mice could potentially contribute to the beta-cell adaptation exhibited by these mutants, in addition to the increase in beta-cell mass that we previously reported. We have also shown that lacZ expression, as analyzed by determining beta-galactosidase activity, was up-regulated by incubating betaIns2(-/-lacZ) cells with GLP-1 and/or IBMX, 2 known stimulators of insulin gene expression. These cells thus represent a new tool for testing of molecules capable of stimulating Ins2 promoter activity.
Department of Genetics, Development and Molecular Pathology, Institut Cochin, INSERM, CNRS, Université René Descartes, Paris, France.
Loïc
L
Leroux
Béatrice
B
Durel
Valérie
V
Autier
Louise
L
Deltour
Danielle
D
Bucchini
Jacques
J
Jami
Rajiv L
RL
Joshi
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003433:Crosses, Genetic; D017931:DNA Primers; D005947:Glucose / Q000494:pharmacology; D007150:Immunohistochemistry; D007328:Insulin / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D007333:Insulin Resistance / Q000235:genetics*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics
D017931:DNA Primers; D007328:Insulin; D001616:beta-Galactosidase; D005947:Glucose