Structure-toxicity analysis of type-2 alkenes:: In vitro neurotoxicity

被引:70
作者
LoPachin, Richard M.
Barber, David S.
Geohagen, Brian C.
Gavin, Terrence
He, Deke
Das, Soma
机构
[1] Albert Einstein Coll Med, Montefiore Med Ctr, Dept Anesthesiol, Bronx, NY 10467 USA
[2] Univ Florida, Ctr Environm & Human Toxicol, Gainesville, FL 32611 USA
[3] Iona Coll, Dept Chem, New Rochelle, NY 10804 USA
关键词
distal axonopathy; acrolein; acrylamide; adduct formation; neurodegeneration; synapse;
D O I
10.1093/toxsci/kfl127
中图分类号
R99 [毒物学(毒理学)];
学科分类号
100405 ;
摘要
Acrylamide (ACR) is a conjugated type-2 alkene that produces synaptic toxicity presumably by sulthydryl adduction. The alpha,beta-unsaturated carbonyl of ACR is a soft electrophile and, therefore, adduction of nucleophilic thiol groups could occur through a conjugate (Michael) addition reaction. To address the mechanism of thiol adduct formation and corresponding neurotoxicological importance, we defined structure-toxicity relationships among a series of conjugated type-2 alkenes (1 mu M-10mM), which included acrolein and methylvinyl ketone. Results show that exposure of rat striatal synaptosomes to these chemicals produced parallel, concentration-dependent neurotoxic effects that were correlated to loss of free sulfhydryl groups. Although differences in relative potency were evident, all conjugated analogs tested were equiefficacious with respect to maximal neurotoxicity achieved. In contrast, nonconjugated alkene or aldehyde congeners did not cause synaptosomal dysfunction or sulfhydryl loss. Acrolein and other alpha,beta-unsaturated carbonyls are bifunctional (electrophilic reactivity at the G-1 and C-3 positions) and could produce in vitro neurotoxicity by forming protein cross-links rather than thiol monoadducts. Inummoblot analysis detected slower migrating, presumably derivatized, synaptosomal proteins only at very high acrolein concentrations (>= 25mM). Exposure of synaptosomes to high concentrations of ACR (1M), N-ethylmaleimide (10mM), and methyl vinyl ketone (MVK) (100mM) did not alter the gel migration of synaptosomal proteins. Furthermore, hydralazine (1mM), which blocks the formation of protein cross-links, did not affect in vitro acrolein neurotoxicity. Thus, type-2-conjugated alkenes produced synaptosomal toxicity that was linked to a loss of thiol content. This is consistent with our hypothesis that the mechanism of ACR neurotoxicity involves formation of Michael adducts with protein sulfhydryl groups.
引用
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页码:136 / 146
页数:11
相关论文
共 45 条
[21]  
KEMP DS, 1980, ORGANIC CHEM, P650
[22]   THE ROLE OF MITOCHONDRIAL GLUTATHIONE AND CELLULAR PROTEIN SULFHYDRYLS IN FORMALDEHYDE TOXICITY IN GLUTATHIONE-DEPLETED RAT HEPATOCYTES [J].
KU, RH ;
BILLINGS, RE .
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1986, 247 (01) :183-189
[23]   1,N2-deoxyguanosine adducts of acrolein, crotonaldehyde, and trans-4-hydroxynonenal cross-link to peptides via Schiff base linkage [J].
Kurtz, AJ ;
Lloyd, RS .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2003, 278 (08) :5970-5976
[24]   THE SENSITIVITIES OF CREATINE AND ADENYLATE KINASES TO THE NEUROTOXINS ACRYLAMIDE AND METHYL NORMAL-BUTYL KETONE [J].
LAPIN, EP ;
WEISSBARTH, S ;
MAKER, HS ;
LEHRER, GM .
ENVIRONMENTAL RESEARCH, 1982, 28 (01) :21-31
[25]   Acrylamide neuropathy III. Spatiotemporal characteristics of nerve cell damage in forebrain [J].
Lehning, EJ ;
Balaban, CD ;
Ross, JF ;
LoPachin, RM .
NEUROTOXICOLOGY, 2003, 24 (01) :125-136
[26]   Acrylamide inhibits dopamine uptake in rat striatal synaptic vesicles [J].
LoPachin, RM ;
Barber, DS ;
He, DK ;
Das, S .
TOXICOLOGICAL SCIENCES, 2006, 89 (01) :224-234
[27]   Protein adduct formation as a molecular mechanism in neurotoxicity [J].
LoPachin, RM ;
DeCaprio, AP .
TOXICOLOGICAL SCIENCES, 2005, 86 (02) :214-225
[28]   2,5-hexanedione-induced changes in the monomeric neurofilament protein content of rat spinal cord fractions [J].
LoPachin, RM ;
He, D ;
Reid, ML ;
Opanashuk, LA .
TOXICOLOGY AND APPLIED PHARMACOLOGY, 2004, 198 (01) :61-73
[29]   In vivo and in vitro effects of acrylamide on synaptosomal neurotransmitter uptake and release [J].
LoPachin, RM ;
Schwarcz, AI ;
Gaughan, CL ;
Mansukhani, S ;
Das, S .
NEUROTOXICOLOGY, 2004, 25 (03) :349-363
[30]   Acrylamide axonopathy revisited [J].
LoPachin, RM ;
Balaban, CD ;
Ross, JF .
TOXICOLOGY AND APPLIED PHARMACOLOGY, 2003, 188 (03) :135-153