Histamine Articles 5

© 2012

Distribution and properties of human intestinal diamine oxidase and its relevance for the histamine catabolism

         (Bieganski, Kusche et al. 1983) Download

High activities of diamine oxidase (EC 1.4.3.6) were measured in the intestinal tract of human subjects and of several mammalian species. The enzyme was localized in the mucosa and was distributed primarily in the cytoplasm; the only exception being the guinea-pig where it was located in the particulate fraction. Despite its instability the enzyme from human colonic mucosa was purified 80-fold. During the purification a soluble monoamine oxidase (EC 1.4.3.4) was separated from diamine oxidase. The pH optima of diamine oxidase for putrescine and histamine were 6.6-7.0 and 6.4-6.6, respectively. Short-chain aliphatic diamines were deaminated with the highest reaction velocity, but histamine and N tau-methylhistamine were also excellent substrates. The Km for putrescine was 8.3 x 10(-5) M, for histamine 1.9 x 10(-5) M and for N tau-methylhistamine 9.7 x 10(-5) M. Typical substrates of monoamine oxidase were not deaminated by the enzyme. Aminoguanidine strongly inhibited human intestinal diamine oxidase (IC50 = 1.1 x 10(-8) M). Because of its properties the intestinal diamine oxidase is considered to play a protective role against histamine in diseases such as ischaemic bowel syndrome, mesenteric infarction and ulcerative colitis.

Severity of ulcerative colitis is associated with a polymorphism at diamine oxidase gene but not at histamine N-methyltransferase gene

            (Garcia-Martin, Mendoza et al. 2006) Download

AIM: To analyse the role of two common polymorphisms in genes coding for histamine metabolising enzymes as it relates to the risk to develop ulcerative colitis (UC) and the clinical course of these patients. METHODS: A cohort of 229 unrelated patients with UC recruited from a single centre and 261 healthy volunteers were analysed for the presence of Thr105Ile and His645Asp amino acid substitutions at histamine N-methyltransferase (HNMT) and diamine oxidase (ABP1) enzymes, respectively, by amplification-restriction procedures. All patients were phenotyped and followed up for at least 2 years (mean time 11 years). RESULTS: There were no significant differences in the distribution of ABP1 alleles between ulcerative colitis patients and healthy individuals [OR (95% CI) for variant alleles=1.22 (0.91-1.61)]. However, mutated ABP1 alleles were present with higher frequency among the 58 patients that required immunosuppressive drugs [OR (95 % CI) for carriers of mutated alleles 2.41 (1.21-4.83; P=0.006)], with a significant gene-dose effect (P=0.0038). In agreement with the predominant role of ABP1 versus HNMT on local histamine metabolism in human bowel, the frequencies for carriers of HNMT genotypes or mutated alleles were similar among patients, regardless clinical evolution, and control individuals. CONCLUSION: The His645Asp polymorphism of the histamine metabolising enzyme ABP1 is related to severity of ulcerative colitis.

Histamine and histamine intolerance

            (Maintz and Novak 2007) Download

Histamine intolerance results from a disequilibrium of accumulated histamine and the capacity for histamine degradation. Histamine is a biogenic amine that occurs to various degrees in many foods. In healthy persons, dietary histamine can be rapidly detoxified by amine oxidases, whereas persons with low amine oxidase activity are at risk of histamine toxicity. Diamine oxidase (DAO) is the main enzyme for the metabolism of ingested histamine. It has been proposed that DAO, when functioning as a secretory protein, may be responsible for scavenging extracellular histamine after mediator release. Conversely, histamine N-methyltransferase, the other important enzyme inactivating histamine, is a cytosolic protein that can convert histamine only in the intracellular space of cells. An impaired histamine degradation based on reduced DAO activity and the resulting histamine excess may cause numerous symptoms mimicking an allergic reaction. The ingestion of histamine-rich food or of alcohol or drugs that release histamine or block DAO may provoke diarrhea, headache, rhinoconjunctival symptoms, asthma, hypotension, arrhythmia, urticaria, pruritus, flushing, and other conditions in patients with histamine intolerance. Symptoms can be reduced by a histamine-free diet or be eliminated by antihistamines. However, because of the multifaceted nature of the symptoms, the existence of histamine intolerance has been underestimated, and further studies based on double-blind, placebo-controlled provocations are needed. In patients in whom the abovementioned symptoms are triggered by the corresponding substances and who have a negative diagnosis of allergy or internal disorders, histamine intolerance should be considered as an underlying pathomechanism.


Structure and inhibition of human diamine oxidase

         (McGrath, Hilmer et al. 2009) Download

Humans have three functioning genes that encode copper-containing amine oxidases. The product of the AOC1 gene is a so-called diamine oxidase (hDAO), named for its substrate preference for diamines, particularly histamine. hDAO has been cloned and expressed in insect cells and the structure of the native enzyme determined by X-ray crystallography to a resolution of 1.8 A. The homodimeric structure has the archetypal amine oxidase fold. Two active sites, one in each subunit, are characterized by the presence of a copper ion and a topaquinone residue formed by the post-translational modification of a tyrosine. Although hDAO shares 37.9% sequence identity with another human copper amine oxidase, semicarbazide sensitive amine oxidase or vascular adhesion protein-1, its substrate binding pocket and entry channel are distinctly different in accord with the different substrate specificities. The structures of two inhibitor complexes of hDAO, berenil and pentamidine, have been refined to resolutions of 2.1 and 2.2 A, respectively. They bind noncovalently in the active-site channel. The inhibitor binding suggests that an aspartic acid residue, conserved in all diamine oxidases but absent from other amine oxidases, is responsible for the diamine specificity by interacting with the second amino group of preferred diamine substrates.

Polymorphisms of two histamine-metabolizing enzymes genes and childhood allergic asthma: a case control study

            (Szczepankiewicz, Breborowicz et al. 2010) Download

BACKGROUND: Histamine-metabolizing enzymes (N-methyltransferase and amiloride binding protein 1) are responsible for histamine degradation, a biogenic amine involved in allergic inflammation. Genetic variants of HNMT and ABP1 genes were found to be associated with altered enzyme activity. We hypothesized that alleles leading to decreased enzyme activity and, therefore, decreased inactivation of histamine may be responsible for altered susceptibility to asthma. METHODS: The aim of this study was to analyze polymorphisms within the HNMT and ABP1 genes in the group of 149 asthmatic children and in the group of 156 healthy children. The genetic analysis involved four polymorphisms of the HNMT gene: rs2071048 (-1637T/C), rs11569723 (-411C/T), rs1801105 (Thr105Ile = 314C/T) and rs1050891 (1097A/T) and rs1049793 (His645Asp) polymorphism for ABP1 gene. Genotyping was performed with use of PCR-RFLP. Statistical analysis was performed using Statistica software; linkage disequilibrium analysis was done with use of Haploview software. RESULTS: We found an association of TT genotype and T allele of Thr105Ile polymorphism of HNMT gene with asthma. For other polymorphisms for HNMT and ABP1 genes, we have not observed relationship with asthma although the statistical power for some SNPs might not have been sufficient to detect an association. In linkage disequilibrium analysis, moderate linkage was found between -1637C/T and -411C/T polymorphisms of HNMT gene. However, no significant differences in haplotype frequencies were found between the group of the patients and the control group. CONCLUSIONS: Our results indicate modifying influence of histamine N-methyltransferase functional polymorphism on the risk of asthma. The other HNMT polymorphisms and ABP1 functional polymorphism seem unlikely to affect the risk of asthma.

Knock-out of the histidine decarboxylase gene modifies the repertoire of natural autoantibodies

         (Quintana, Buzas et al. 2004) Download

Natural antibodies (NA) are antibodies produced in the absence of known immunization with specific antigens. NA are found in the blood of healthy humans and mice. Histamine influences many aspects of the immune response, including antibody production. However, the role of histamine in the generation of NA has not yet been studied. In this work, we used an ELISA assay to characterize the self-antigen binding repertoires of NA in wild type (WT) mice and in histidine decarboxylase knock-out (HDC-KO) mice, unable to synthesize histamine. We now report that HDC-KO and WT mice differed in the patterns of autoreactivity of their IgM and IgG NA. The NA in HDC-KO sera manifested a larger repertoire of IgM autoantibodies than did the WT sera. The self-antigens bound by IgM from HDC-KO mice included structural proteins, enzymes associated with cellular metabolism, double-stranded and single-stranded DNA, and tissue-specific antigens like insulin. There were relatively fewer differences in the NA repertoire of IgG autoantibodies of the mice: notably, the HDC-KO sera reacted with glutamic acid decarboxylase (GAD), an antigen associated with autoimmune diabetes. These results demonstrate that endogenous histamine can influence the self-reactivity of the NA repertoire.

Green tea epigallocatechin-3-gallate is an inhibitor of mammalian histidine decarboxylase

            (Rodriguez-Caso, Rodriguez-Agudo et al. 2003) Download

(-)-epigallocatechin-3-gallate, an antiproliferative and antiangiogenic component of green tea, has been reported to inhibit dopa decarboxylase. In this report,we show that this compound also inhibits histidine decarboxylase, the enzymic activity responsible for histamine biosynthesis. This inhibition was proved by a double approach, activity measurements and UV-Vis spectra of enzyme-bound pyridoxal-5'-phosphate. At 0.1 mM (-)-epi-gallocatechin-3-gallate, histidine decarboxylase activity was inhibited by more than 60% and the typical spectrum of the internal aldimine form shifted to a stable major maximum at 345 nm, suggesting that the compound causes a stable change in the structure of the holoenzyme. Since histamine release is one of the primary events in many inflammatory responses, a new potential application of (-)-epigallocatechin-3-gallate in prevention or treatment of inflammatory processes is suggested by these data.

Analysis of antibody reactivity against cysteine sulfinic acid decarboxylase, a pyridoxal phosphate-dependent enzyme, in endocrine autoimmune disease

         (Skoldberg, Rorsman et al. 2004) Download

The structurally related group II pyridoxal phosphate (PLP)-dependent amino acid decarboxylases glutamic acid decarboxylase (GAD), aromatic L-amino acid decarboxylase (AADC), and histidine decarboxylase (HDC) are known autoantigens in endocrine disorders. We report, for the first time, the prevalence of serum autoantibody reactivity against cysteine sulfinic acid decarboxylase (CSAD), an enzyme that shares 50% amino acid identity with the 65- and 67-kDa isoforms of GAD (GAD-65 and GAD-67), in endocrine autoimmune disease. Three of 83 patients (3.6%) with autoimmune polyendocrine syndrome type 1 (APS1) were anti-CSAD positive in a radioimmunoprecipitation assay. Anti-CSAD antibodies cross-reacted with GAD-65, and the anti-CSAD-positive sera were also reactive with AADC and HDC. The low frequency of anti-CSAD reactivity is in striking contrast to the prevalence of antibodies against GAD-65, AADC, and HDC in APS1 patients, suggesting that different mechanisms control the immunological tolerance toward CSAD and the other group II decarboxylases. Moreover, CSAD may be a useful mold for the construction of recombinant chimerical antigens in attempts to map conformational epitopes on other group II PLP-dependent amino acid decarboxylases.




References

Bieganski, T., J. Kusche, et al. (1983). "Distribution and properties of human intestinal diamine oxidase and its relevance for the histamine catabolism." Biochim Biophys Acta 756(2): 196-203.

Garcia-Martin, E., J. L. Mendoza, et al. (2006). "Severity of ulcerative colitis is associated with a polymorphism at diamine oxidase gene but not at histamine N-methyltransferase gene." World J Gastroenterol 12(4): 615-20.

Maintz, L. and N. Novak (2007). "Histamine and histamine intolerance." Am J Clin Nutr 85(5): 1185-96.

McGrath, A. P., K. M. Hilmer, et al. (2009). "Structure and inhibition of human diamine oxidase." Biochemistry 48(41): 9810-22.

Quintana, F. J., E. Buzas, et al. (2004). "Knock-out of the histidine decarboxylase gene modifies the repertoire of natural autoantibodies." J Autoimmun 22(4): 297-305.

Rodriguez-Caso, C., D. Rodriguez-Agudo, et al. (2003). "Green tea epigallocatechin-3-gallate is an inhibitor of mammalian histidine decarboxylase." Cell Mol Life Sci 60(8): 1760-3.

Skoldberg, F., F. Rorsman, et al. (2004). "Analysis of antibody reactivity against cysteine sulfinic acid decarboxylase, a pyridoxal phosphate-dependent enzyme, in endocrine autoimmune disease." J Clin Endocrinol Metab 89(4): 1636-40.

Szczepankiewicz, A., A. Breborowicz, et al. (2010). "Polymorphisms of two histamine-metabolizing enzymes genes and childhood allergic asthma: a case control study." Clin Mol Allergy 8: 14.