ABSTRACT
Biological agents including anti-tumor necrosis factor (anti-TNF; adalimumab, infliximab, etanercept) and anti-interleukin-12/13 (IL12/23; ustekinumab) are essential for treatment of patients with severe psoriasis. However, a significant proportion of the patients do not respond to a specific treatment. Pharmacogenetics might be a way to predict treatment response. Using a candidate gene approach, 62 mainly functional single-nucleotide polymorphisms (SNPs) in 44 different genes were evaluated in 478 Danish patients with psoriasis undergoing 376 series of anti-TNF treatment and 230 series of ustekinumab treatment. Associations between genetic variants and treatment outcomes (drug survival and Psoriasis Area Severity Index reduction) were assessed using logistic regression analyses (crude and adjusted for gender, age, psoriatic arthritis and previous treatment). After correction for multiple testing controlling the false discovery rate, six SNPs (IL1B (rs1143623, rs1143627), LY96 (rs11465996), TLR2 (rs11938228, rs4696480) and TLR9 (rs352139)) were associated with response to anti-TNF treatment and 4 SNPs (IL1B (rs1143623, rs1143627), TIRAP (rs8177374) and TLR5 (rs5744174)) were associated with response to ustekinumab treatment (q<0.20). The results suggest that genetic variants related to increased IL-1ß levels may be unfavorable when treating psoriasis with either anti-TNF or ustekinumab, whereas genetic variants related to high interferon-γ levels may be favorable when treating psoriasis with ustekinumab.
Subject(s)
Pharmacogenetics/methods , Psoriasis/drug therapy , Psoriasis/genetics , Adalimumab/administration & dosage , Adalimumab/adverse effects , Adult , Denmark , Etanercept/administration & dosage , Etanercept/adverse effects , Female , Humans , Infliximab/administration & dosage , Infliximab/adverse effects , Interleukin-1beta/genetics , Lymphocyte Antigen 96/genetics , Male , Membrane Glycoproteins/genetics , Middle Aged , Polymorphism, Single Nucleotide , Psoriasis/epidemiology , Psoriasis/pathology , Receptors, Interleukin-1/genetics , Toll-Like Receptor 2/genetics , Toll-Like Receptor 9/genetics , Treatment Outcome , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Ustekinumab/administration & dosage , Ustekinumab/adverse effectsABSTRACT
Oxazolidinone antibiotics inhibit bacterial protein synthesis by interacting with the large ribosomal subunit. The structure and exact location of the oxazolidinone binding site remain obscure, as does the manner in which these drugs inhibit translation. To investigate the drug-ribosome interaction, we selected Escherichia coli oxazolidinone-resistant mutants, which contained a randomly mutagenized plasmid-borne rRNA operon. The same mutation, G2032 to A, was identified in the 23S rRNA genes of several independent resistant isolates. Engineering of this mutation by site-directed mutagenesis in the wild-type rRNA operon produced an oxazolidinone resistance phenotype, establishing that the G2032A substitution was the determinant of resistance. Engineered U and C substitutions at G2032, as well as a G2447-to-U mutation, also conferred resistance to oxazolidinone. All the characterized resistance mutations were clustered in the vicinity of the central loop of domain V of 23S rRNA, suggesting that this rRNA region plays a major role in the interaction of the drug with the ribosome. Although the central loop of domain V is an essential integral component of the ribosomal peptidyl transferase, oxazolidinones do not inhibit peptide bond formation, and thus these drugs presumably interfere with another activity associated with the peptidyl transferase center.
Subject(s)
Acetamides/pharmacology , Anti-Bacterial Agents/pharmacology , Escherichia coli/genetics , Oxazolidinones/pharmacology , RNA, Bacterial/genetics , RNA, Ribosomal, 23S/genetics , Acetamides/chemistry , Acetamides/metabolism , Amino Acid Substitution , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Base Sequence , Binding Sites , Catalysis , Catalytic Domain , Drug Resistance, Microbial , Escherichia coli/drug effects , Escherichia coli/isolation & purification , Genes, Bacterial , Genetic Engineering , Linezolid , Molecular Sequence Data , Molecular Structure , Mutagenesis , Nucleic Acid Conformation , Oxazolidinones/chemistry , Oxazolidinones/metabolism , Peptidyl Transferases/metabolism , RNA, Bacterial/chemistry , RNA, Ribosomal, 23S/chemistry , RibosomesABSTRACT
A possible role of low pH in secretory vesicles for processing and secretion in the neurohypophysis was investigated. Subcellular fractionation of guinea-pig neural lobes revealed that a proton present in the membranes from this tissue could not be ascribed to secretory vesicles. However, a proton pump was found in coated microvesicles. Secretory vesicles isolated from rats and guinea pigs were stable under conditions known to lyse secretory vesicles from the adrenal medulla owing to the generation of a proton gradient. These results suggest that the internal pH of secretory vesicles from the neurohypophysis is closer to neutral than is the pH in chromaffin secretory vesicles. Processing of a neurophysin-glycopeptide intermediate from the biosynthesis of vasopressin in intact secretory vesicles incubated in vitro was activated by the addition of NH4Cl, known to increase the intravesicular pH. This activation of neurohormone processing was also apparent in isolated nerve endings incubated in the presence of NH4Cl, suggesting that NH4Cl can also be used to increase the intravesicular pH in intact nerve endings. However, NH4Cl did not affect the secretion of neurohormones, indicating that a low intravesicular pH is not important for exocytosis in the neurohypophysis. Our results indicate that a low pH generated during processing by mechanisms other than ATP-dependent proton transport may inhibit the processing enzymes, thereby preventing extensive breakdown of neurohormone precursors.
