Hepatic expression profiles in retroviral infection: relevance to drug hypersensitivity risk

Biotransformation mechanism of Vibrio diabolicus to sulfamethoxazole at transcriptional level

Sulfamethoxazole (SMX) has attracted much attention due to its high probability of detection in the environment. Marine bacteria Vibrio diabolicus strain L2-2 has been proven to be able to transform SMX. In this study, the potential resistance and biotransformation mechanism of strain L2-2 to SMX, and key genes responses to SMX at environmental concentrations were researched. KEGG pathways were enriched by down-regulated genes including degradation of L-Leucine, L-Isoleucine, and fatty acid metabolism. Resistance mechanism could be concluded as the enhancement of membrane transport, antioxidation, response regulator, repair proteins, and ribosome protection. Biotransformation genes might involve in arylamine N-acetyltransferases (nat), cytochrome c553 (cyc-553) and acyl-CoA synthetase (acs). At the environmental concentration of SMX (0.1-10 μg/L), nat was not be activated, which meant the acetylation of SMX might not occur in the environment; however, cyc-553 was up-regulated under SMX stress of 1 μg/L, which indicated the hydroxylation of SMX could occur in the environment. Besides, the membrane transport and antioxidation of strain L2-2 could be activated under SMX stress of 10 μg/L. The results provided a better understanding of resistance and biotransformation of bacteria to SMX and would support related researches about the impacts of environmental antibiotics.

A tunable pair electrochemical strategy for the synthesis of new benzenesulfonamide derivatives

A green, facile and tunable pair electrochemical process was developed for the synthesis of new benzenesulfonamide derivatives by using reductive controlled potential electrolysis of dinitrobenzene (DNB) in the presence of arylsulfinic acids (ASAs). In addition to the usual features associated with paired electrochemical methods, eg high energy efficient, this method has a tunable characteristic, so that, by adjusting the potential, different products can be synthesized. By applying the potential of -0.4 V vs. Ag/AgCl, N-hydroxy-N-(4-nitrophenyl)benzenesulfonamide derivatives are selectively formed, while, by applying the potential of -1.1 V vs. Ag/AgCl, the final products are N-(4-amino-3-(phenylsulfonyl)phenyl) benzenesulfonamide derivatives. This work beautifully shows the potential applications of the electrochemistry as a powerful tool for the synthesis of organic compounds.

Hepatic expression profiles in retroviral infection: relevance to drug hypersensitivity risk

HIV‐infected patients show a markedly increased risk of delayed hypersensitivity (HS) reactions to potentiated sulfonamide antibiotics (trimethoprim/sulfamethoxazole or TMP/SMX). Some studies have suggested altered SMX biotransformation in HIV infection, but hepatic biotransformation pathways have not been evaluated directly. Systemic lupus erythematosus (SLE) is another chronic inflammatory disease with a higher incidence of sulfonamide HS, but it is unclear whether retroviral infection and SLE share risk factors for drug HS. We hypothesized that retroviral infection would lead to dysregulation of hepatic pathways of SMX biotransformation, as well as pathway alterations in common with SLE that could contribute to drug HS risk. We characterized hepatic expression profiles and enzymatic activities in an SIV‐infected macaque model of retroviral infection, and found no evidence for dysregulation of sulfonamide drug biotransformation pathways. Specifically, NAT1,NAT2,CYP2C8,CYP2C9,CYB5R3,MARC1/2, and glutathione‐related genes (GCLC,GCLM,GSS,GSTM1, and GSTP1) were not differentially expressed in drug naïve SIVmac239‐infected male macaques compared to age‐matched controls, and activities for SMX N‐acetylation and SMX hydroxylamine reduction were not different. However, multiple genes that are reportedly over‐expressed in SLE patients were also up‐regulated in retroviral infection, to include enhanced immunoproteasomal processing and presentation of antigens as well as up‐regulation of gene clusters that may be permissive to autoimmunity. These findings support the hypothesis that pathways downstream from drug biotransformation may be primarily important in drug HS risk in HIV infection.