Analysis of differentially expressed mRNA in gingival tissue of hypertensive rats with or without periodontitis based on next-generation sequencing

Objective To employ next-generation sequencing (NGS) to analyze differentially expressed mRNAs in the gingival tissue of hypertensive rats with or without periodontitis to provide a theoretical basis for the prevention and treatment of hypertension with periodontitis. Methods After obtaining approval from the Animal Experiment Ethics Committee, a hypertensive rat model was established by administering high-salt feed containing 8%（w/w） NaCl, and a periodontitis rat model was established by ligating the first molar of the mandibular region using 3-0 sterile silk thread. Rat models of the normal control (N), hypertension (H), and hypertension with periodontitis (PH) groups were established. The blood pressure, heart rate, alveolar bone resorption, and number of osteoclasts in the alveolar bone were measured, before harvesting the gingival tissues from the three groups for NGS to analyze the expression of significantly different genes. Gene ontology (GO) enrichment analysis was performed for all significantly differentially expressed genes between the H and PH groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed. Key genes were screened by protein-protein interaction (PPI) networks, and the key gene expression in each group was verified using immunohistochemistry (IHC). The expression of key genes in the systemic circulation of each group was analyzed using enzyme-linked immunosorbent assay (ELISA). Results At the end of the experiment (11th week), the blood pressure was higher in both the H and PH groups than that in the N group (PPPP