S-allyl cysteine in combination with clotrimazole downregulates Fas induced apoptotic events in erythrocytes of mice exposed to lead

• Published in: Biochimica et biophysica acta Vol. 1820; no. 1; pp. 9 - 23
• Main Authors: Mandal, Samir, Mukherjee, Sudip, Chowdhury, Kaustav Dutta, Sarkar, Avik, Basu, Kankana, Paul, Soumosish, Karmakar, Debasish, Chatterjee, Mahasweta, Biswas, Tuli, Sadhukhan, Gobinda Chandra, Sen, Gargi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 2012
• Subjects: Animals; Apoptosis; ceramides; Clotrimazole; Clotrimazole - pharmacology; confocal microscopy; Cysteine - analogs & derivatives; Cysteine - pharmacology; death; diallyl disulfide; Down-Regulation - drug effects; Erythrocyte; erythrocytes; Erythrocytes - drug effects; Erythrocytes - metabolism; Erythrocytes - pathology; fas Receptor - metabolism; Female; flow cytometry; gels; immunoblotting; Lead; Lead - toxicity; Lead Poisoning - blood; Lead Poisoning - pathology; longevity; Mass Spectrometry; Mice; Mice, Inbred BALB C; oxidative stress; plasma membrane; potassium; Reactive Oxygen Species; S allyl cysteine; scanning electron microscopy; Signal Transduction; therapeutics; toxicity; NADPH; Pb 2; Reactive oxygen species; PS; CLT; CDNB; SH group; FACS; K; BSA; FITC; TBA; NADH; DADS; LDL; Lead; OH; S allyl cysteine; NADP; GSH; SGOT; PBS; DTNB; aSMase; RBCs; GST; TBARS; DMTU; GPx; NAD; H 2O 2; Erythrocyte; WBCs; SAC; DISC; ROS; DMSA; FCS; DAS; Prx2; MiADMSA; SGPT; HNE; HPF; Clotrimazole; Apoptosis
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2011.09.019

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).
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.
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
+
.
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.
► Erythrocyte death during Pb
2
+
exposure is characterized by PS externalization at the outer membrane leaflet. ► Erythrocyte death is triggered by oxidative stress and K
+ loss. ► The death signaling pathway include redistribution of Fas to lipid rafts and Fas aggregation. ► Combination therapy (S-allyl cysteine and clotrimazole) inhibited ROS generation and K
+ loss. ► Combination therapy initiated apoptosis inhibiting events in a better way than monotherapy.