Impact of DEFB1 gene regulatory polymorphisms on hBD-1 salivary concentration.
OBJECTIVE
Human β-defensin 1 (hBD-1) is an antimicrobial peptide involved in epithelial defence of various tissues, also present in the saliva. Individual genetic variations within the DEFB1 gene, encoding for hBD-1, could influence gene expression and protein production.


METHODS
Three DEFB1 polymorphisms at 5' untranslated region (UTR), -52G > A (rs1799946), -44C > G (rs1800972) and -20G > A (rs11362), and two polymorphisms at DEFB1 3' UTR, c*5G > A (rs1047031) and c*87A > G (rs1800971), were analysed by direct sequencing and correlated with hDB-1 salivary concentration (tested with enzyme-linked immunosorbent assay (ELISA)) in 40 healthy subjects.


RESULTS
Significant associations were found between individuals presenting different DEFB1 polymorphisms at positions -52 and -44 of the gene and hBD-1 salivary concentrations: -52 G/G carriers had higher levels of protein than G/A and A/A; -44C/G subjects showed a higher protein concentration than homozygous wild-type C/C. For the -20G > A, c*5G > A and c*87A > G polymorphisms, no statistically significant differences were found. Combined haplotype analysis confirmed the results obtained considering the single-nucleotide polymorphisms (SNPs) singularly.


CONCLUSIONS
Polymorphisms in the DEFB1 gene influence hBD-1 production and, therefore, could modify the innate immune system responses and, consequently, the oral health.
Institute for Maternal and Child Health, IRCCS 'Burlo Garofolo', Trieste, Italy.
Vania
V
Polesello
Institute for Maternal and Child Health, IRCCS 'Burlo Garofolo', Trieste, Italy.
Luisa
L
Zupin
Division of Oral Medicine and Pathology, Dental Science Department, University of Trieste, Trieste, Italy.
Roberto
R
Di Lenarda
Division of Oral Medicine and Pathology, Dental Science Department, University of Trieste, Trieste, Italy.
Matteo
M
Biasotto
Division of Oral Medicine and Pathology, Dental Science Department, University of Trieste, Trieste, Italy.
Giulia
G
Ottaviani
Division of Oral Medicine and Pathology, Dental Science Department, University of Trieste, Trieste, Italy.
Margherita
M
Gobbo
Division of Oral Medicine and Pathology, Dental Science Department, University of Trieste, Trieste, Italy.
Luca
L
Cecco
Institute for Maternal and Child Health, IRCCS 'Burlo Garofolo', Trieste, Italy.
Giulia
G
Alberi
Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy.
Gabriele
G
Pozzato
Institute for Maternal and Child Health, IRCCS 'Burlo Garofolo', Trieste, Italy; Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy.
Sergio
S
Crovella
Institute for Maternal and Child Health, IRCCS 'Burlo Garofolo', Trieste, Italy. Electronic address: ludovica.segat@burlo.trieste.it.
Ludovica
L
Segat
D000328:Adult; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D064368:Healthy Volunteers; D006801:Humans; D007558:Italy; D008297:Male; D020641:Polymorphism, Single Nucleotide; D012463:Saliva / Q000737:chemistry*; D023083:beta-Defensins / Q000235:genetics*
C406407:DEFB1 protein, human; D023083:beta-Defensins
Antimicrobial peptide; DEFB1; SNP; Saliva