TY - JOUR
T1 - Calreticulin transacetylase catalyzed modification of the TNF-α mediated pathway in the human peripheral blood mononuclear cells by polyphenolic acetates
AU - Singh, Usha
AU - Kumar, Ajit
AU - Sinha, Rajesh
AU - Manral, Sushma
AU - Arora, Shvetambri
AU - Ram, Sant
AU - Mishra, Rakesh K.
AU - Gupta, Prachi
AU - Bansal, Surendra K.
AU - Prasad, Ashok K.
AU - Biswal, Shyam
AU - Parmar, Virinder S.
AU - Raj, Hanumantharao G.
PY - 2010/5
Y1 - 2010/5
N2 - Polyphenols, coumarin (1,2-benzopyrone) and chromone (1,4-benzopyrone), are naturally occurring constituent of variety of plant species. They have attracted immense interest because of their diverse pharmacological activities. Not much was known about biological activities of acetyl derivative (polyphenolic acetates) of parent polyphenols. In previous investigations, we have conclusively established calreticulin transacetylase catalyzed activation of endothelial nitric oxide synthase (eNOS) by polyphenolic acetates. In the present work, calreticulin transacetylase of human peripheral blood mononuclear cells was characterized with respect to specificity for various polyphenolic acetates and its role in the activation of TNF-α induced nitric oxide synthase (iNOS). Peripheral blood mononuclear cells incubated with a model polyphenolic acetate, 7,8-diacetoxy-4-methylcoumarin (DAMC), along with l-arginine caused activation of NOS. The incubation of peripheral blood mononuclear cells with TNF-α and DAMC resulted in increased production of NO as compared to TNF-α alone. This increased NO production was attenuated by l-Nω-nitro-l-arginine methyl ester (l-NAME), a well known non-specific inhibitor of NOS, and 1400W (N-[3-(aminomethyl) benzyl] acetamidine), a specific inhibitor of human iNOS. These results substantiate the CRTAase catalyzed activation of iNOS. Further, expression of NOS isoforms by semi-quantitative PCR and real-time RT-PCR confirms the preponderance of iNOS in TNF-α treated peripheral blood mononuclear cells over the untreated one. It was also observed that polyphenolic acetates inhibit TNF-α mediated release of IL-6 from peripheral blood mononuclear cells.
AB - Polyphenols, coumarin (1,2-benzopyrone) and chromone (1,4-benzopyrone), are naturally occurring constituent of variety of plant species. They have attracted immense interest because of their diverse pharmacological activities. Not much was known about biological activities of acetyl derivative (polyphenolic acetates) of parent polyphenols. In previous investigations, we have conclusively established calreticulin transacetylase catalyzed activation of endothelial nitric oxide synthase (eNOS) by polyphenolic acetates. In the present work, calreticulin transacetylase of human peripheral blood mononuclear cells was characterized with respect to specificity for various polyphenolic acetates and its role in the activation of TNF-α induced nitric oxide synthase (iNOS). Peripheral blood mononuclear cells incubated with a model polyphenolic acetate, 7,8-diacetoxy-4-methylcoumarin (DAMC), along with l-arginine caused activation of NOS. The incubation of peripheral blood mononuclear cells with TNF-α and DAMC resulted in increased production of NO as compared to TNF-α alone. This increased NO production was attenuated by l-Nω-nitro-l-arginine methyl ester (l-NAME), a well known non-specific inhibitor of NOS, and 1400W (N-[3-(aminomethyl) benzyl] acetamidine), a specific inhibitor of human iNOS. These results substantiate the CRTAase catalyzed activation of iNOS. Further, expression of NOS isoforms by semi-quantitative PCR and real-time RT-PCR confirms the preponderance of iNOS in TNF-α treated peripheral blood mononuclear cells over the untreated one. It was also observed that polyphenolic acetates inhibit TNF-α mediated release of IL-6 from peripheral blood mononuclear cells.
KW - Calreticulin transacetylase
KW - IL-6
KW - Nitric oxide synthase
KW - Peripheral blood mononuclear cells
KW - TNF-α
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U2 - 10.1016/j.cbi.2010.02.025
DO - 10.1016/j.cbi.2010.02.025
M3 - Article
C2 - 20188080
AN - SCOPUS:77952302967
SN - 0009-2797
VL - 185
SP - 263
EP - 270
JO - Chemico-Biological Interactions
JF - Chemico-Biological Interactions
IS - 3
ER -