Disease relevance of AOAH

• These data indicate that AOAH activity increases in leukocytes associated with inflammation induced by gram-negative bacteria and provide additional evidence of its potential involvement in the defense against the effects of bacterial endotoxin [1].
• 0. By using Escherichia coli infection of the bovine mammary gland as a model of localized gram-negative bacterial disease and associated tissue inflammation, AOAH activity per leukocyte increased [1].

High impact information on AOAH

• Human acyloxyacyl hydrolase (AOAH) is a leukocyte enzyme that hydrolyzes acyloxyacyl bonds in the lipid A region of bacterial lipopolysaccharide (LPS), thereby detoxifying the LPS [2].
• The demonstration that AOAH has phospholipase, lysophospholipase, diacylglycerol lipase, and acyltransferase activities in vitro suggests that the enzyme may have roles in addition to LPS deacylation (detoxification) in phagocytic cells [2].
• While AOAH preferentially removes palmitate or stearate from the sn-1 position of phospholipid and diacylglycerol substrates that have unsaturated acyl chains in the sn-2 position, it is able to cleave both palmitates from sn-1,2-dipalmitoylphosphatidylcholine and sn-1,2-dipalmitoylglycerol [2].
• AOAH also catalyzes acyl transfer from LPS and phosphatidylethanolamine to acceptor lipids; approximately equal amounts of laurate and myristate are transferred from LPS to monooleoylglyceryl ether, forming acyloleoylglyceryl ether [2].
• Because both AOAH and soluble CD14 respond to LPS, we tested for gene-gene interaction [3].

Biological context of AOAH

• OBJECTIVE: We hypothesized that variants in AOAH are associated with asthma and related phenotypes [3].
• There was no difference in AOAH expression levels by AOAH genotype for any of the markers [3].
• RESULTS: Significant effects were observed for all 4 phenotypes and AOAH markers in 3 distinct regions (promoter, introns 1-6, and the intron 12/exon 13 boundary/intron 13 region) by means of single-marker and haplotype analyses, with the strongest evidence for a 2-single-nucleotide-polymorphism haplotype and log[tIgE] (P = .006) [3].
• BACKGROUND: The gene encoding acyloxyacyl hydroxylase (AOAH), an enzyme that hydrolyzes secondary fatty acyl chains of LPS, is localized on chromosome 7p14-p12, where evidence for linkage to total IgE (tIgE) concentrations and asthma has been previously reported [3].

Anatomical context of AOAH

• AOAH is a leukocyte enzyme that selectively removes the secondary (acyloxyacyl-linked) fatty acyl chains from the lipid A region of bacterial lipopolysaccharides (endotoxins), thereby detoxifying the molecules [4].
• The molecular cloning and eukaryotic cell expression of the complementary DNA for human neutrophil acyloxyacyl hydrolase (AOAH) are described [4].
• Acyloxyacyl hydrolase (AOAH), an enzyme that removes the secondary acyl chains of gram-negative bacterial lipid A (endotoxin), has been identified previously in human neutrophils and mouse macrophages [1].

Associations of AOAH with chemical compounds

• The recombinant enzyme, like native AOAH, hydrolyzes secondary acyl chains from more than one position on the lipopolysaccharide backbone [4].
• The AOAH was positively correlated with vitamin C (r = 0.92, p < 0.01) and total phenolic (r = 0.97, p < 0.01) but was negatively correlated with beta-carotene (r = -0.73, p = 0.03) [5].
• A ferric reducing antioxidant power assay was used to estimate both AOAH and AOAL from methanol and dichloromethane extracts, respectively [5].

Other interactions of AOAH

• These up-regulated genes were ADP/ATP translocase (AAT2), Na(+)/K(+) ATPase, acyloxyacyl hydrolase (AOAH), and platelet-derived growth factor (PDFG-A) [6].

Analytical, diagnostic and therapeutic context of AOAH

• Chromosomal localization of the acyloxyacyl hydrolase (AOAH) gene to 7p14-p12 using fluorescence in situ hybridization [7].
• Real-time PCR was used to assess whether AOAH cDNA expression differed with AOAH genotype [3].

References