Deletion of protein kinase Cδ in mice modulates stability of inflammatory genes and protects against cytokine-stimulated beta cell death in vitro and in vivo

Aims/hypothesis Proinflammatory cytokines contribute to beta cell destruction in type 1 diabetes, but the mechanisms are incompletely understood. The aim of the current study was to address the role of the protein kinase C (PKC) isoform PKCδ, a diverse regulator of cell death, in cytokine-stimulated...

Full description

Saved in:
Bibliographic Details
Published in:Diabetologia 2011-02, Vol.54 (2), p.380-389
Main Authors: Cantley, J, Boslem, E, Laybutt, D. R, Cordery, D. V, Pearson, G, Carpenter, L, Leitges, M, Biden, T. J
Format: Article
Language:English
Subjects:
Animals
Apoptosis - drug effects
Apoptosis - genetics
Beta cell
Biological and medical sciences
Blotting, Western
cytokines
Cytokines - pharmacology
Diabetes. Impaired glucose tolerance
Endocrine pancreas. Apud cells (diseases)
Endocrinopathies
Etiopathogenesis. Screening. Investigations. Target tissue resistance
Human Physiology
In Vitro Techniques
insulin-dependent diabetes mellitus
Insulin-Secreting Cells - cytology
Insulin-Secreting Cells - drug effects
Insulin-Secreting Cells - metabolism
Interferon-gamma - pharmacology
Interleukin-1beta - pharmacology
Internal Medicine
islets of Langerhans
Islets of Langerhans - cytology
Isoenzymes - genetics
Isoenzymes - metabolism
Medical sciences
Medicine
Medicine & Public Health
Metabolic Diseases
Mice
Mice, Knockout
mRNA stabilisation
NOS2
Phosphorylation - drug effects
Polymerase Chain Reaction
protein kinase C
Protein Kinase C-delta - genetics
Protein Kinase C-delta - metabolism
streptozotocin
Toll-like receptor
Tumor Necrosis Factor-alpha - pharmacology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Aims/hypothesis Proinflammatory cytokines contribute to beta cell destruction in type 1 diabetes, but the mechanisms are incompletely understood. The aim of the current study was to address the role of the protein kinase C (PKC) isoform PKCδ, a diverse regulator of cell death, in cytokine-stimulated apoptosis in primary beta cells. Methods Islets isolated from wild-type or Prkcd ⁻/⁻ mice were treated with IL-1β, TNF-α and IFNγ and assayed for apoptosis, nitric oxide (NO) generation and insulin secretion. Activation of signalling pathways, apoptosis and endoplasmic reticulum (ER) stress were determined by immunoblotting. Stabilisation of mRNA transcripts was measured by RT-PCR following transcriptional arrest. Mice were injected with multiple low doses of streptozotocin (MLD-STZ) and fasting blood glucose monitored. Results Deletion of Prkcd inhibited apoptosis and NO generation in islets stimulated ex vivo with cytokines. It also delayed the onset of hyperglycaemia in MLD-STZ-treated mice. Activation of ERK, p38, JNK, AKT1, the ER stress markers DDIT3 and phospho-EIF2α and the intrinsic apoptotic markers BCL2 and MCL1 was not different between genotypes. However, deletion of Prkcd destabilised mRNA transcripts for Nos2, and for multiple components of the toll-like receptor 2 (TLR2) signalling complex, which resulted in disrupted TLR2 signalling. Conclusions/interpretation Loss of PKCδ partially protects against hyperglycaemia in the MLD-STZ model in vivo, and against cytokine-mediated apoptosis in vitro. This is accompanied by reduced NO generation and destabilisation of Nos2 and components of the TLR2 signalling pathway. The results highlight a mechanism for regulating proinflammatory gene expression in beta cells independently of transcription.
ISSN:0012-186X
1432-0428
DOI:10.1007/s00125-010-1962-y