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Overexpression of Akt (protein kinase B) confers protection against apoptosis and prevents formation of ceramide in response to pro-apoptotic stimuli.
J Neurosci Res. 1999 Sep 15; 57(6):884-93.JN

Abstract

An immortalized dorsal root ganglion cell line F-11 exhibits many properties of spinal cord neurons and undergoes apoptosis in response to growth factor withdrawal and the exogenous addition of inhibitors of phosphatidylinositol-3-kinase (PI3K). To elucidate the mechanism of apoptosis we generated F-11 clones which overexpressed either the p110 subunit of PI3K, a constitutively active form of protein kinase B/Akt (Myristoylated Akt), or a dominant-negative form (c-Akt). The first two constructs were protective against apoptosis induced by PI3K inhibitors such as wortmannin and LY294002. Caspase-3 (CPP32) levels peaked at 4 hr to 6 hr in response to pro-apoptotic drugs, and this increase was attenuated by 50% in F-11 with constitutively active Akt. The Akt protection was confirmed by DNA fragmentation studies. Both neo-transfected and the c-Akt dominant-negative transfected F-11 cells showed increased ceramide formation (twofold) in response to staurosporine, wortmannin, or LY294002; whereas cells with a constitutively active Akt (Myr-Akt) showed no increase in ceramide when treated with staurosporine, wortmannin, or LY294002. Ceramide was a more potent activator of CPP32 and an inducer of apoptosis when added as the native form (hydroxy- or nonhydroxy-), rather than the more water-soluble C(2)-ceramide. Overexpression of PI3K (p110) and Akt protected cells against ceramide-induced apoptosis, suggesting that Ceramide action is upstream of Akt in these cells and suggesting that Akt might be a target for inhibition by ceramide. Both staurosporine and C(2)-ceramide activated the Jun kinase (JNK) cascade and C(2)-ceramide increased caspase-3 (CPP32) activity in cells expressing wild-type c-Jun, but not dominant-negative (TAM-67) c-Jun. We suggest that this pathway is also involved in apoptosis, consistent with the idea that ceramide has multiple kinase and kinase-modulating targets in the apoptotic pathway of neurons. J. Neurosci. Sci. 57:884-893, 1999.

Authors+Show Affiliations

Department of Pediatrics and Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

10467260

Citation

Goswami, R, et al. "Overexpression of Akt (protein Kinase B) Confers Protection Against Apoptosis and Prevents Formation of Ceramide in Response to Pro-apoptotic Stimuli." Journal of Neuroscience Research, vol. 57, no. 6, 1999, pp. 884-93.
Goswami R, Kilkus J, Dawson SA, et al. Overexpression of Akt (protein kinase B) confers protection against apoptosis and prevents formation of ceramide in response to pro-apoptotic stimuli. J Neurosci Res. 1999;57(6):884-93.
Goswami, R., Kilkus, J., Dawson, S. A., & Dawson, G. (1999). Overexpression of Akt (protein kinase B) confers protection against apoptosis and prevents formation of ceramide in response to pro-apoptotic stimuli. Journal of Neuroscience Research, 57(6), 884-93.
Goswami R, et al. Overexpression of Akt (protein Kinase B) Confers Protection Against Apoptosis and Prevents Formation of Ceramide in Response to Pro-apoptotic Stimuli. J Neurosci Res. 1999 Sep 15;57(6):884-93. PubMed PMID: 10467260.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Overexpression of Akt (protein kinase B) confers protection against apoptosis and prevents formation of ceramide in response to pro-apoptotic stimuli. AU - Goswami,R, AU - Kilkus,J, AU - Dawson,S A, AU - Dawson,G, PY - 1999/9/1/pubmed PY - 1999/9/1/medline PY - 1999/9/1/entrez SP - 884 EP - 93 JF - Journal of neuroscience research JO - J Neurosci Res VL - 57 IS - 6 N2 - An immortalized dorsal root ganglion cell line F-11 exhibits many properties of spinal cord neurons and undergoes apoptosis in response to growth factor withdrawal and the exogenous addition of inhibitors of phosphatidylinositol-3-kinase (PI3K). To elucidate the mechanism of apoptosis we generated F-11 clones which overexpressed either the p110 subunit of PI3K, a constitutively active form of protein kinase B/Akt (Myristoylated Akt), or a dominant-negative form (c-Akt). The first two constructs were protective against apoptosis induced by PI3K inhibitors such as wortmannin and LY294002. Caspase-3 (CPP32) levels peaked at 4 hr to 6 hr in response to pro-apoptotic drugs, and this increase was attenuated by 50% in F-11 with constitutively active Akt. The Akt protection was confirmed by DNA fragmentation studies. Both neo-transfected and the c-Akt dominant-negative transfected F-11 cells showed increased ceramide formation (twofold) in response to staurosporine, wortmannin, or LY294002; whereas cells with a constitutively active Akt (Myr-Akt) showed no increase in ceramide when treated with staurosporine, wortmannin, or LY294002. Ceramide was a more potent activator of CPP32 and an inducer of apoptosis when added as the native form (hydroxy- or nonhydroxy-), rather than the more water-soluble C(2)-ceramide. Overexpression of PI3K (p110) and Akt protected cells against ceramide-induced apoptosis, suggesting that Ceramide action is upstream of Akt in these cells and suggesting that Akt might be a target for inhibition by ceramide. Both staurosporine and C(2)-ceramide activated the Jun kinase (JNK) cascade and C(2)-ceramide increased caspase-3 (CPP32) activity in cells expressing wild-type c-Jun, but not dominant-negative (TAM-67) c-Jun. We suggest that this pathway is also involved in apoptosis, consistent with the idea that ceramide has multiple kinase and kinase-modulating targets in the apoptotic pathway of neurons. J. Neurosci. Sci. 57:884-893, 1999. SN - 0360-4012 UR - https://www.unboundmedicine.com/medline/citation/10467260/Overexpression_of_Akt__protein_kinase_B__confers_protection_against_apoptosis_and_prevents_formation_of_ceramide_in_response_to_pro_apoptotic_stimuli_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0360-4012&date=1999&volume=57&issue=6&spage=884 DB - PRIME DP - Unbound Medicine ER -