Relationship between oral and gut microbes / 华西口腔医学杂志

Oral cavity and gut are important parts of the human digestive tract. The structure and pathogenesis of oral and gut microbial communities have been extensively investigated. The interaction and pathogenic effects of oral and gut microbiota have also been widely explored. This review aimed to integrate data from literature and discuss the structures and functions of microbial communities in the oral cavity and gut. The mutual colonization and pathogenesis of oral and gut microbes and the relationship between these phenomena and involved systemic diseases are also described.

Application of saliva in disease diagnosis / 华西口腔医学杂志

Saliva is secreted by salivary glands and performs a variety of functions, including mouth cleaning and protection, antibacterial activity, and digestion. With the rapid progress in salivaomics, saliva became recognized as a potential pool of biological markers. Being a non-invasive and safe source, saliva is a potential substitute for blood in diagnosis and prognosis of diseases. This review summarizes the latest advancement in saliva-related studies and presents the potential value of saliva in early diagnosis of oral diseases, such as dental caries, periodontal disease, cancer, diabetes, and other systemic disorders. Saliva biomarkers can reveal changes ranging from changes in biochemical index, DNA, RNA, and proteins to the diversification of microbiota structure. By integrating recent data, this paper discusses the clinical significance and application prospect of saliva in early diagnosis of diseases and in translational and precision medicine.

Progress on space oral medicine research under microgravity environment / 华西口腔医学杂志

As an interdisciplinary of stomatology and space medicine, space oral medicine focuses mainly on oral diseases happened under space environment. With the manned space technology stepping into the new era, space oral medicine has been put under the spotlight. This article will review the historical events on this subject, summarize the newly progress especially on craniomaxillofacial bone, tooth-derived stem cell and oral microbiology researches and still put forward future prospect.

Cloning, expression, and purification of c-di-AMP metabolism-related genes from Porphyromonas gingivalis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To clone, express, and purify cyclic diadenosine monophosphate (c-di-AMP) metabolism-related genes from Porphyromonas gingivalis (P. gingivalis) ATCC33277.</p><p><b>METHODS</b>Polymerase chain reaction (PCR) from the genome of P. gingivalis ATCC33277 amplified, the coding regions of pgn0523, pgn1187, and pgn2003 genes. The amplified DNA fragments were ligated with a prokaryotic expression vector pET28a to construct the recombinant expression plasmids pET-pgn0523, pET-pgn1187, and pET-pgn2003. These recombinant plasmids were transformed into Escherichia coli (E. coli) BL21 (DE3) competent cells. The expression of recombinant proteins was induced by isopropyl-β-D-thiogalactoside and detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Proteins were purified using a Ni²⁺ matrix column, and their concentrations were determined by a BCA Protein Quantitative Kit.</p><p><b>RESULTS</b>The c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 were amplified successfully with the correct molecular size. The recombinant expression vectors were constructed by ligating enzyme-digested PCR products and pET28a vector, and verified by PCR and sequencing. After induction and purification, recombinant proteins were expressed successfully and obtained with the correct molecular size (19.5 x 10³, 39.9 x 10³, 66.0 x 10³). The final protein concentrations were 0.708, 0.523, and 0.861 mg · mL⁻¹ after dialysis.</p><p><b>CONCLUSION</b>The c-di-AMP metabolism-related genes from P. gingivalis ATCC33277 are cloned successfully, and their coding products are expressed correctly in E. coli. High-purity proteins are finally obtained. The cloning and purification of these important proteins will help us to further investigate the physiological function and regulatory mechanism of c-di-AMP signaling system in P. gingivalis.</p>