Prevalence of Human Papillomavirus (HPV)-16 in Different Dental Infections in the Lebanese Population.

BACKGROUND: Dental infections, which are the main cause of tooth loss, are known to be caused by bacteria. However, recent research suggests that other organisms, such as viruses, may also play a role. In this study, we aim to detect the presence of human papillomavirus (HPV)-16 and assess its prevalence in tissues infected with various dental infections, including aggressive and chronic periodontitis, pericoronitis, and periapical infection, as well as healthy gingival tissues, saliva, and gingival crevicular fluid, for comparison. METHODS: A cross-sectional study including 124 adult healthy patients presenting with dental infections requiring dental extractions were conducted to assess the prevalence of HPV-16 in saliva, infected, and healthy tissues using quantitative polymerase chain reaction (PCR) tests. Samples were collected and a categorical scale was used for the prevalence. Statistical analyses were performed using Chi-square for the prevalence of HPV-16. RESULTS: Among the HPV-16-positive PCR cases, the prevalence of HPV-16 was highest in periapical infection tissues as compared to chronic periodontitis, aggressive periodontitis, pericoronitis, and control tissues. CONCLUSION: The prevalence of HPV-16 in periapical infection samples was the highest among the studied dental infection samples. Thus, a primary conclusion can be drawn about the presence of an association between HPV-16 and the occurrence of periapical infection.

Functional and splicing defect analysis of 23 ACVRL1 mutations in a cohort of patients affected by Hereditary Hemorrhagic Telangiectasia.

Hereditary Hemorrhagic Telangiectasia syndrome (HHT) or Rendu-Osler-Weber (ROW) syndrome is an autosomal dominant vascular disorder. Two most common forms of HHT, HHT1 and HHT2, have been linked to mutations in the endoglin (ENG) and activin receptor-like kinase 1 (ACVRL1or ALK1) genes respectively. This work was designed to examine the pathogenicity of 23 nucleotide variations in ACVRL1 gene detected in more than 400 patients. Among them, 14 missense mutations and one intronic variant were novels, and 8 missense mutations were previously identified with questionable implication in HHT2. The functionality of missense mutations was analyzed in response to BMP9 (specific ligand of ALK1), the maturation of the protein products and their localization were analyzed by western blot and fluorescence microscopy. The splicing impairment of the intronic and of two missense mutations was examined by minigene assay. Functional analysis showed that 18 out of 22 missense mutations were defective. Splicing analysis revealed that one missense mutation (c.733A>G, p.Ile245Val) affects the splicing of the harboring exon 6. Similarly, the intronic mutation outside the consensus splicing sites (c.1048+5G>A in intron 7) was seen pathogenic by splicing study. Both mutations induce a frame shift creating a premature stop codon likely resulting in mRNA degradation by NMD surveillance mechanism. Our results confirm the haploinsufficiency model proposed for HHT2. The affected allele of ACVRL1 induces mRNA degradation or the synthesis of a protein lacking the receptor activity. Furthermore, our data demonstrate that functional and splicing analyses together, represent two robust diagnostic tools to be used by geneticists confronted with novel or conflicted ACVRL1 mutations.