Disease relevance of DEFB103A

• The solution structures of the human beta-defensins lead to a better understanding of the potent bactericidal activity of HBD3 against Staphylococcus aureus [1].
• Synthetic hBD-3 exhibits a strong antimicrobial activity against gram-negative and gram-positive bacteria and fungi, including Burkholderia cepacia [2].
• AIM: To examine human beta-defensin-3 (hBD-3) expression in inflamed gastric mucosal tissues or MKN45 gastric cancer cells with or without H pylori infection for better understanding the innate immune response to H pylori [3].
• CONCLUSION: Our results suggest that like hBD-2, hBD-3 may be involved in the pathophysiology of H pylori-induced gastritis [3].
• In cases of leukoplakia, a strong signal of hBD-3 mRNA was observed in the granular layer [4].

Psychiatry related information on DEFB103A

• CONCLUSION: These findings widen our knowledge of the functional spectrum of APs and demonstrate that HBD-3 is a multifunctional AP with the ability to link host defense mechanisms and inflammation with tissue-remodeling processes in articular cartilage [5].

High impact information on DEFB103A

• We found that sterile wounding of human skin induced epidermal expression of the antimicrobial (poly)peptides human beta-defensin-3, neutrophil gelatinase-associated lipocalin, and secretory leukocyte protease inhibitor through activation of the epidermal growth factor receptor [6].
• PCP-A1, a defensin-like Brassica pollen coat protein that binds the S locus glycoprotein, is the product of gametophytic gene expression [7].
• Unexpectedly, all differently folded hBD3 species exhibited similar antimicrobial activity against Escherichia coli, whereas a wide range of chemotactic activities was observed with these analogs for monocytes and cells transfected by the chemokine receptor CCR6 [8].
• Our findings demonstrate that disulfide bonding in hBD3, although required for binding and activation of receptors for chemotaxis, is fully dispensable for its antimicrobial function, thus shedding light on the mechanisms of action for human beta-defensins and the design of novel peptide antibiotics [8].
• Furthermore, whereas substitution of all Cys residues by alpha-aminobutyric acid completely abolished the chemotactic activity of hBD3, the bactericidal activity remained unaffected in the absence of any disulfide bridge [8].

Chemical compound and disease context of DEFB103A

• Tumor necrosis factor alpha and contact with bacteria were found to induce hBD-3 mRNA expression. hBD-3 therefore might be important in the innate epithelial defense of infections by various microorganisms seen in skin and lung, such as cystic fibrosis [9].

Biological context of DEFB103A

• These findings demonstrate that HDs act at multiple steps in the HSV life cycle and support the development of defensins or defensin-like peptides as microbicides [10].
• Here we report the identification of a third human beta-defensin, called human beta-defensin 3 (hBD-3; cDNA sequence, Genbank accession no. AF295370), based on bioinformatics and functional genomic analysis [2].
• The purpose of this study was to investigate the expression of human beta-defensins (hBD), especially of the recently discovered hBD-3, in oral tissues by reverse-transcription polymerase chain reaction (RT-PCR) [11].
• The induced expression of hBD-3 was mediated by transactivation of the epidermal growth factor receptor [12].
• Application of the recombinant HBD-3 protein to cultured chondrocytes and cartilage discs resulted in increased production of cartilage-degrading matrix metalloproteinases and in down-regulation of their endogenous regulators, tissue inhibitors of metalloproteinases 1 and 2 [5].

Anatomical context of DEFB103A

• In addition, hBD-3 activates monocytes and elicits ion channel activity in biomembranes, specifically in oocytes of Xenopus laevis [2].
• Oral keratinocytes, but not fibroblasts, contained transcripts for all beta-defensins, suggesting that the novel hBD-3 is also produced in the epithelial compartment of oral tissues [11].
• Human beta-defensin-3 induction in H pylori-infected gastric mucosal tissues [3].
• Localization of human beta-defensin 3 mRNA in normal oral epithelium, leukoplakia, and lichen planus: an in situ hybridization study [4].
• Human beta-defensin 3 (hBD-3), an antimicrobial peptide, is produced by various epithelial and some nonepithelial tissues. hBD-3 mRNA is widely expressed in oral tissues, including oral epithelium and the salivary glands [4].

Associations of DEFB103A with chemical compounds

• HBD3 bound both gB and heparan sulfate, but hBD1 and hBD2 bound neither [10].
• In contrast, an LD(90) of hBD-3 more than doubled calcein release from cells yet did not result in more than 24% of total release, showing that neither peptide caused gross membrane damage [13].
• Pretreatment of C. albicans cells with sodium azide resulted in significantly decreased ATP release and susceptibility of cells to hBD-2 and hBD-3 [13].
• In our experimental conditions, L-isoleucine, described to stimulate beta-defensin in bovine epithelial cells, did not exert any effect either on hBD-2 and hBD-3 transcripts or MIP-3alpha protein [14].
• In this report we demonstrate that HBD-2 and HBD-3 are susceptible to degradation and inactivation by the cysteine proteases cathepsins B, L, and S [15].

Regulatory relationships of DEFB103A

• In in vitro cultures of primary endometrial epithelial cells, HBD3 mRNA expression is upregulated by treatment with inflammatory molecules including IL-1 beta+TNF alpha, IFN gamma and phorbol ester [16].

Other interactions of DEFB103A

• All three techniques are in agreement, suggesting that HBD-3 is a dimer, while HBD-1 and HBD-2 are monomeric [1].
• Both HBD1 and HBD3 form well defined structures with backbone root mean square deviations of 0.451 and 0.616 A, respectively [1].
• Analysis of the NMR data and structures led us to suggest that HBD3 forms a symmetrical dimer through strand beta2 of the beta-sheet [1].
• Among the bacteria tested in this study, F. nucleatum was highly susceptible to hBD3 and LL37, and S. mutans was highly susceptible to hBD3 [17].
• Inhibition was greater against CXCR4-tropic than against the CCR5-tropic HIV-1 isolates. hBD-2 and hBD-3 induced an irreversible effect on virion infectivity, with electron microscopy confirming binding of hBDs to viral particles [18].

Analytical, diagnostic and therapeutic context of DEFB103A

• Following UVA1 phototherapy, hBD-1 mRNA decreased in lesional, but not in unaffected skin. hBD-3 mRNA levels significantly decreased after UVA1 in lesional skin, whereas an increase of hBD-3 was observed in unaffected skin [19].
• METHODS: We used reverse transcription-polymerase chain reactions and immunohistochemistry to examine hBD-3 expression in inflamed gastric mucosal tissues or MKN45 gastric cancer cells with or without H pylori [3].
• METHODS: Healthy and OA cartilage were assessed for HBD-3 expression by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry [5].
• Enzyme-linked immunosorbent assay experiments were used to study the effects of HBD-3 in cultured articular chondrocytes and in healthy and OA cartilage discs [5].
• Molecular cloning and biochemical analyses of antimicrobial peptides in cell culture supernatants revealed keratinocytes and airway epithelial cells as cellular sources of hBD-3 [9].

References