Document Detail


Bcl-2 and caspase-3 are major regulators in Agaricus blazei-induced human leukemic U937 cell apoptosis through dephoshorylation of Akt.
MedLine Citation:
PMID:  17666799     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Agaricus blazei is a medicinal mushroom that possesses antimetastatic, antitumor, antimutagenic, and immunostimulating effects. However, the molecular mechanisms involved in A. blazei-mediated apoptosis remain unclear. In the present study, to elucidate the role of the Bcl-2 in A. blazei-mediated apoptosis, U937 cells were transfected with either empty vector (U937/vec) or vector containing cDNA encoding full-length Bcl-2 (U937/Bcl-2). As compared with U937/vec, U937/Bcl-2 cells exhibited a 4-fold greater expression of Bcl-2. Treatment of U937/vec with 1.0-4.0 mg/ml of A. blazei extract (ABE) for 24 h resulted in a significant induction of morphologic features indicative of apoptosis. In contrast, U937/Bcl-2 exposed to the same ABE treatment only exhibited a slight induction of apoptotic features. ABE-induced apoptosis was accompanied by downregulation of antiapoptotic proteins such as X-linked inhibitor of apoptosis protein (XIAP), inhibitor of apoptosis protein (cIAP)-2 and Bcl-2, activation of caspase-3, and cleavage of poly(ADP-ribose)polymerase (PARP). Ectopic expression of Bcl-2 was associated with significantly induced expression of antiapoptotic proteins, such as cIAP-2 and Bcl-2, but not XIAP. Ectopic expression of Bcl-2 also reduced caspase-3 activation and PARP cleavage in ABE treated U937 cells. Furthermore, treatment with the caspase-3 inhibitor z-DEVD-fmk was sufficient to restore cell viability following ABE treatment. This increase in viability was ascribed to downregulation of caspase-3 and blockage of PARP and PLC-gamma cleavage. ABE also triggered the downregulation of Akt, and combined treatment with LY294002 (an inhibitor of Akt) significantly decreased cell viability. The results indicated that major regulators of ABE-induced apoptosis in human leukemic U937 cells are Bcl-2 and caspase-3, which are associated with dephosphorylation of the Akt signal pathway.
Authors:
Cheng-Yun Jin; Dong-Oh Moon; Yung Hyun Choi; Jae-Dong Lee; Gi-Young Kim
Related Documents :
9811849 - Caspase-3 controls both cytoplasmic and nuclear events associated with fas-mediated apo...
10753639 - Resistance to apoptosis is correlated with the reduced caspase-3 activation and enhance...
19956899 - Apoptosis induction of human leukemia cells by streptomyces sp. sy-103 metabolites thro...
9651349 - Induction of a caspase-3-like activity by calcium in normal cytosolic extracts triggers...
8696339 - Cleavage of huntingtin by apopain, a proapoptotic cysteine protease, is modulated by th...
15163549 - Apoptotic injury in cultured human hepatocytes induced by hmg-coa reductase inhibitors.
9170099 - The effects of interferon-gamma on the central nervous system.
9651179 - Induction, duration, and resolution of airway goblet cell hyperplasia in a murine model...
20732069 - Immunotoxicology and allergy: opportunities for in vitro analysis.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Biological & pharmaceutical bulletin     Volume:  30     ISSN:  0918-6158     ISO Abbreviation:  Biol. Pharm. Bull.     Publication Date:  2007 Aug 
Date Detail:
Created Date:  2007-08-01     Completed Date:  2007-09-21     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  9311984     Medline TA:  Biol Pharm Bull     Country:  Japan    
Other Details:
Languages:  eng     Pagination:  1432-7     Citation Subset:  IM    
Affiliation:
Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 614-052, Republic of Korea.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Agaricus / chemistry*
Apoptosis / drug effects*
Caspase 3 / antagonists & inhibitors,  metabolism,  physiology*
Caspases / metabolism
Cell Survival / drug effects
Electrophoresis, Polyacrylamide Gel
Enzyme Activation / drug effects
Flow Cytometry
Fluorescent Dyes
Humans
Indicators and Reagents
Indoles
Oligopeptides / pharmacology
Oncogene Protein v-akt / metabolism,  physiology*
Phosphorylation
Proto-Oncogene Proteins c-bcl-2 / physiology*
U937 Cells
Chemical
Reg. No./Substance:
0/Fluorescent Dyes; 0/Indicators and Reagents; 0/Indoles; 0/Oligopeptides; 0/Proto-Oncogene Proteins c-bcl-2; 0/benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; 47165-04-8/DAPI; EC 2.7.11.1/Oncogene Protein v-akt; EC 3.4.22.-/Caspase 3; EC 3.4.22.-/Caspases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Protective effects of Cuscutae semen against dimethylnitrosamine-induced acute liver injury in Sprag...
Next Document:  Sinomenine, an antirheumatic alkaloid, ameliorates clinical signs of disease in the Lewis rat model ...