Increased expression and levels of human β defensins (hBD2 and hBD4) in adults with dental caries

Abstract

Introduction: Defensins are small anti-microbial peptides produced by epithelial cells. These peptides have a broad range of actions against microorganisms, including Gram-positive and Gram-negative bacteria.Human defensins are classifi ed into two subfamilies, the α-, and β- defensins, which differ in their distribution of disulphide bonds between the six conserved cysteine residues. Defensins are found in salivaand others compartments of the body. Human β defensins 2 (hBD2), beta defensins 4 (hBD4) and alpha defensins 4 (hNP4) in saliva may contributes to vulnerability or resistance to caries. This study aimed to determine a possible correlation between caries and levels of defensins measuring the expression in gingival tissue and concentrations in saliva samples.Methods: Oral examinations were performed on 100 adults of both genders (18-30 years old), and unstimulated whole saliva was collected for immunoassays of the three peptides and for the salivary pH, buffercapacity, protein, and peroxidase activity. mRNA levels of defensins in gingival sample were assessed by semi-quantitative RT-PCR technique.Results: The median salivary levels of hBD2 and hBD4 were 1.88 μg/ml and 0.86 μg/ml respectively for the caries-free group (n=44) and 7.26 μ/ml (hBD2) and 4.25 μg/ml (hBD4) for all subjects with evidenceof caries (n=56). There was no difference in the levels of hNP4, salivary pH, and proteins between groups, however the peroxidase activity and buffer capacity (interval 6.0-5.0) were reduced in caries group. Transcriptional levels of hBD2 and hBD4 did correlate with caries experience, the mRNA expression of hBD2 and hBD4 were signifi cantly higher in patients with caries than in patients with no-caries (p < 0.01).Conclusion: We conclude that high salivary levels and expression of beta defensins, low peroxidase activity and buffer capacity may represent a biological response of oral tissue to caries. Our observation couldlead to new ways to prevent caries and a new tool for caries risk assessment.

The Levels of the Human-β-Defensin-2 and LL-37 in the Sputum of Children with Cystic Fibrosis: A Case–control Study and Literature Review

“…In other studies, researchers assessed the content of AMPs in saliva. Ghosh et al, 2007, andBarrera et al, 2013, showed that the concentration of hBD-2 in healthy people ranges from 9.5 (1.2-21) μg/l, but in BAL is 0.04 (0-0.049) μg/g. Although, fluctuations in the content of hBD-2 in saliva and BAL are not synchronized [33], [34].…”

“…Ghosh et al, 2007, andBarrera et al, 2013, showed that the concentration of hBD-2 in healthy people ranges from 9.5 (1.2-21) μg/l, but in BAL is 0.04 (0-0.049) μg/g. Although, fluctuations in the content of hBD-2 in saliva and BAL are not synchronized [33], [34]. According to Kozubska et al, 2020, a median concentration of hBD-2 in the saliva of healthy children is 621 pg/mL and ranges from undetectable to 7.20 ng/mL.…”

Salivary Proteins and Effects on Dental Caries: Review

“…İnsan beta-defensin-2 (HBD-2), beta defensin-4 (hBD-4) ve alfa defensin-4 (Hnp-4) proteininin tükürükteki varlığı çürüğe karşı bir direnç sağlamaktadır. 38 …”

Beta-defensins-2 expressions in gingival epithelium cells after probiotic Lactobacillus reuteri induction

“…In the optimal conditions, antimicrobial activities of defensins work at low concentration of 1-10mg /mL. 3 Human beta-defensins (hBDs) are widely expressed in tissues of the oral cavity, including gingival epithelium, salivary glands, saliva and salivary duct. These peptides are involved in defense against bacteria that colonizes in the oral cavity.…”

“…Human beta-defensins have broad antimicrobial activity against oral microorganisms, such as Streptococcus mutans, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans. 3 Changes in lifestyle and diet can affect the composition and amount of the normal flora in someone's oral cavity. Several factors causing the occurrence of dental caries are physical factors, biological factors, environmental factors, habits, and life style.…”