Characterization of methyl-beta-cyclodextrin toxicity in NGF-differentiated PC12 cell death.
Cyclodextrins (CDs) are used to deliver hydrophobic molecules in aqueous environments. Methyl-beta-cyclodextrin (MbetaCD), a member of this family of molecules, has been proposed to be a good carrier to deliver fatty acids to cells in culture. This report focuses on studying the in vitro effects of MbetaCD on nerve growth factor-differentiated PC12 (NGFDPC12) cells, a tissue culture model to study neuronal survival and differentiation. The main findings are: (1) NGFDPC12 cells have normal viability when exposed to 0.12% MbetaCD but showed a significant loss in cell viability at higher concentrations; (2) NGFDPC12 cells exposed to 0.25% MbetaCD exhibit nuclear condensation, blebbing and apoptotic bodies, and whole cell lysates exhibited an increase in caspase-3-like activity and high levels of Bax and Bcl-X(L) protein expression compared to control. Cultures treated with 0.25% MbetaCD also showed cleavage of normal 21-kDa Bax protein into a 18-kDa fragment. (3) Experiments using 0.12% MbetaCD to deliver oleic acid did not affect cell viability, in contrast NGFDPC12 cultures in which 0.25% MbetaCD concentration is used exhibited similar loss of cell viability as observed with 0.25% MbetaCD alone. Treating these cultures with caspase-3 inhibitor z-VAD-fmk did not protect the cells from MbetaCD toxic effects. (4) Immortalized Schwann cells (iSC) exposed to MbetaCD 0.12% did not show loss of cell viability while 0.25% MbetaCD triggered a significant toxicity but with a different dose and time course dynamic than NGFDPC12 cells. Thus, NGFDPC12 or iSC cell cultures exposed to 0.12% MbetaCD exhibits normal viability while higher concentrations increase in cell death and apoptosis.
Ulloth
Joel E
JE
Center for Health Disparities and Molecular Medicine, Loma Linda University, School of Medicine, Loma Linda, CA 92350, USA.
Almaguel
Frankis G
FG
Padilla
Amelia
A
Bu
Liming
L
Liu
Jo-Wen
JW
De Leon
Marino
M
D000818:Animals; D000963:Antimetabolites; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D001973:Bromodeoxyuridine; D053143:Caspase 2 / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D002470:Cell Survival / Q000187:drug effects; D005434:Flow Cytometry; D019254:Genes, bcl-2 / Q000187:drug effects; D020287:In Situ Nick-End Labeling; D020932:Nerve Growth Factor / Q000235:genetics*; D019301:Oleic Acid / Q000633:toxicity; D016716:PC12 Cells; D051381:Rats; D012583:Schwann Cells / Q000187:drug effects; D047392:beta-Cyclodextrins / Q000633:toxicity*
D000963:Antimetabolites; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D019301:Oleic Acid; D020932:Nerve Growth Factor; D053143:Caspase 2; D053148:Caspase 3; D053179:Caspase 7; D001973:Bromodeoxyuridine