Differential regulation of CIDEA and CIDEC expression by insulin via Akt1/2- and JNK2-dependent pathways in human adipocytes
| Autor: | Minoru Ito, Koji Murakami, Tomohiro Ide, Michiaki Nagasawa, Yunike Akasaka, Naoki Omae |
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| Rok vydání: | 2011 |
| Předmět: |
Chlorpropamide
phosphatidylinositol 3-kinase Pyridines medicine.medical_treatment Down-Regulation DNA Fragmentation QD415-436 Biology Biochemistry Wortmannin Phosphatidylinositol 3-Kinases chemistry.chemical_compound Endocrinology Downregulation and upregulation Lipid droplet Adipocytes medicine Humans Insulin Mitogen-Activated Protein Kinase 9 Gene Silencing Obesity Phosphorylation RNA Small Interfering Furans Protein Kinase Inhibitors Protein kinase B Research Articles c-Jun N-terminal kinase PI3K/AKT/mTOR pathway Phosphoinositide-3 Kinase Inhibitors lipid droplet formation Kinase apoptosis Proteins Cell Biology small interfering RNA Up-Regulation Pyrimidines Gene Expression Regulation chemistry cell death-inducing DNA fragmentation factor-α-like effector Cancer research Female Signal transduction Apoptosis Regulatory Proteins Proto-Oncogene Proteins c-akt Signal Transduction |
| Zdroj: | Journal of Lipid Research, Vol 52, Iss 8, Pp 1450-1460 (2011) |
| ISSN: | 0022-2275 |
| Popis: | Both insulin and the cell death-inducing DNA fragmentation factor-α-like effector (CIDE) family play important roles in apoptosis and lipid droplet formation. Previously, we reported that CIDEA and CIDEC are differentially regulated by insulin and contribute separately to insulin-induced anti-apoptosis and lipid droplet formation in human adipocytes. However, the upstream signals of CIDE proteins remain unclear. Here, we investigated the signaling molecules involved in insulin regulation of CIDEA and CIDEC expression. The phosphatidylinositol 3-kinase (PI3K) inhibitors wortmannin and PI-103 blocked both insulin-induced downregulation of CIDEA and upregulation of CIDEC. The Akt inhibitor API-2 and the c-Jun N-terminal kinase (JNK) inhibitor SP600125 selectively inhibited insulin regulation of CIDEA and CIDEC expression, respectively, whereas the MAPK/ERK kinase inhibitor U0126 and the p38 inhibitor SB203580 did not. Small interfering RNA-mediated depletion of Akt1/2 prevented insulin-induced downregulation of CIDEA and inhibition of apoptosis. Depletion of JNK2, but not JNK1, inhibited insulin-induced upregulation of CIDEC and lipid droplet enlargement. Furthermore, insulin increased both Akt and JNK phosphorylation, which was abrogated by the PI3K inhibitors. These results suggest that insulin regulates CIDEA and CIDEC expression via PI3K, and it regulates expression of each protein via Akt1/2- and JNK2-dependent pathways, respectively, in human adipocytes. |
| Databáze: | OpenAIRE |
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