Salivary protein polymorphisms and risk of dental caries: a systematic review

Abstract Dental caries is an oral pathology associated with both lifestyle and genetic factors. The caries process can be influenced by salivary composition, which includes ions and proteins. Studies have described associations between salivary protein polymorphisms and dental caries experience, while others have shown no association with salivary proteins genetic variability. The aim of this study is to assess the influence of salivary protein polymorphisms on the risk of dental caries by means of a systematic review of the current literature. An electronic search was performed in PubMed, Scopus, and Virtual Health Library. The following search terms were used: “dental caries susceptibility,” “dental caries,” “polymorphism, genetics,” “saliva,” “proteins,” and “peptides.” Related MeSH headings and free terms were included. The inclusion criteria comprised clinical investigations of subjects with and without caries. After application of these eligibility criteria, the selected articles were qualified by assessing their methodological quality. Initially, 338 articles were identified from the electronic databases after exclusion of duplicates. Exclusion criteria eliminated 322 articles, and 16 remained for evaluation. Eleven articles found a consistent association between salivary protein polymorphisms and risk of dental caries, for proteins related to antimicrobial activity (beta defensin 1 and lysozyme-like protein), pH control (carbonic anhydrase VI), and bacterial colonization/adhesion (lactotransferrin, mucin, and proline-rich protein Db). This systematic review demonstrated an association between genetic polymorphisms and risk of dental caries for most of the salivary proteins.

5-Bromo-2’-deoxyuridine induces visible morphological alteration in the DNA puffs of the anterior salivary gland region of Bradysia hygida (Diptera, Sciaridae)

5-Bromo-2’-deoxyuridine (BrdUrd) has long been known to interfere with cell differentiation. We found that treatment ofBradysia hygida larvae with BrdUrd during DNA puff anlage formation in the polytene chromosomes of the salivary gland S1 region noticeably affects anlage morphology. However, it does not affect subsequent metamorphosis to the adult stage. The chromatin of the chromosomal sites that would normally form DNA puffs remains very compact and DNA puff expansion does not occur with administration of 4 to 8 mM BrdUrd. Injection of BrdUrd at different ages provoked a gradient of compaction of the DNA puff chromatin, leading to the formation of very small to almost normal puffs. By immunodetection, we show that the analogue is preferentially incorporated into the DNA puff anlages. When BrdUrd is injected in a mixture with thymidine, it is not incorporated into the DNA, and normal DNA puffs form. Therefore, incorporation of this analogue into the amplified DNA seems to be the cause of this extreme compaction. Autoradiographic experiments and silver grains counting showed that this treatment decreases the efficiency of RNA synthesis at DNA puff anlages.

Association of salivary proteins with dental caries in a Colombian population

La saliva tiene un importante papel en el mantenimiento de las condiciones normales de los tejidos orales. La variabilidad en la composición salival determina su característica protectoracontra la caries dental. Conocer el contenido molecular de la saliva en humanos es importante para el entendimiento de sus propiedades biológicas. El objetivo de este trabajo fue reconocer la composición proteica de la saliva completa de sujetoscon caries activa (AC), historia de caries (HC) y libres de caries (H); en una población colombiana por medio del patrón electroforético y su correlación con el diagnóstico clínico. Cientocuarenta y cinco pacientes mayores de 18 años de edad fueron clasificados en los grupos de estudio por examinación clínica, las muestras de saliva fueron recolectadas, las determinacionesde proteína total fueron hechas por el método Bradford; la saliva individual fue separada por SDS-PAGE y relacionadas con el índice COP. Los geles fueron analizados por el software Quantity One® 1-D (BIO-RAD). No se encontraron diferencias estadísticamente significativas entre las concentraciones de proteína total y la experiencia o no de caries dental. La cantidad de proteína total fue mayor en mujeres que en hombres (p= 0.0028); y con respecto a la enfermedad fue mayor en mujeres con HC y AC. Las proteínas salivares comunes entre los individuos fueron de 101, 77, 62, 55, 44, 22 y 13 kDa. Se encontró asociación entre la proteína salival de 17 kDa y la AC enhombres. Conclusiones: Las proteínas presentes en la muestra de saliva completa son muy similares en los tres grupos de estudio, excepto por la proteína de 17 kDa la cual puede ser unmarcador de riesgo de caries dental.