S-allyl cysteine in combination with clotrimazole downregulates Fas induced apoptotic events in erythrocytes of mice exposed to lead.
BACKGROUND
Chronic lead (Pb(2+)) exposure leads to the reduced lifespan of erythrocytes. Oxidative stress and K(+) loss accelerate Fas translocation into lipid raft microdomains inducing Fas mediated death signaling in these erythrocytes. Pathophysiological-based therapeutic strategies to combat against erythrocyte death were evaluated using garlic-derived organosulfur compounds like diallyl disulfide (DADS), S allyl cysteine (SAC) and imidazole based Gardos channel inhibitor clotrimazole (CLT).


METHODS
Morphological alterations in erythrocytes were evaluated using scanning electron microscopy. Events associated with erythrocyte death were evaluated using radio labeled probes, flow cytometry and activity gel assay. Mass spectrometry was used for detection of GSH-4-hydroxy-trans-2-nonenal (HNE) adducts. Fas redistribution into the lipid rafts was studied using immunoblotting technique and confocal microscopy.


RESULTS
Combination of SAC and CLT was better than DADS and CLT combination and monotherapy with these agents in prolonging the survival of erythrocytes during chronic Pb(2+) exposure. Combination therapy with SAC and CLT prevented redistribution of Fas into the lipid rafts of the plasma membrane and downregulated Fas-dependent death events in erythrocytes of mice exposed to Pb(2+).


CONCLUSIONS
Ceramide generation was a critical component of Fas receptor-induced apoptosis, since inhibition of acid sphingomyelinase (aSMase) interfered with Fas-induced apoptosis during Pb(2+) exposure. Combination therapy with SAC and CLT downregulated apoptotic events in erythrocytes by antagonizing oxidative stress and Gardos channel that led to suppression of ceramide-initiated Fas aggregation in lipid rafts. Hence, combination therapy with SAC and CLT may be a potential therapeutic option for enhancing the lifespan of erythrocytes during Pb(2+) toxicity.
Indian Institute of Chemical Biology, Kolkata, India.
Samir
S
Mandal
Sudip
S
Mukherjee
Kaustav Dutta
KD
Chowdhury
Avik
A
Sarkar
Kankana
K
Basu
Soumosish
S
Paul
Debasish
D
Karmakar
Mahasweta
M
Chatterjee
Tuli
T
Biswas
Gobinda Chandra
GC
Sadhukhan
Gargi
G
Sen
D000818:Animals; D017209:Apoptosis; D003022:Clotrimazole / Q000494:pharmacology*; D003545:Cysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005260:Female; D007854:Lead / Q000633:toxicity; D007855:Lead Poisoning / Q000097:blood* / Q000473:pathology; D013058:Mass Spectrometry; D051379:Mice; D008807:Mice, Inbred BALB C; D017382:Reactive Oxygen Species; D015398:Signal Transduction; D019014:fas Receptor / Q000378:metabolism*
D017382:Reactive Oxygen Species; D019014:fas Receptor; D007854:Lead; C065299:S-allylcysteine; D003022:Clotrimazole; D003545:Cysteine