Effect of simulated microgravity on porphyromonas gingivalis strain ATCC33277 growth and gene expression

Background: P. gingivalis is the prime aetiological bacteria of initiation and progression of periodontal disease. It is also the risk factor of many system diseases, such as cardiovascular disease, diabetes and pulmonary infection. This study is aiming to demonstrate the effects of stimulated microgravity on p. gingivalis ATCC33277. Methods: We performed the rotary cell culture system (RCCS) to stimulate the microgravity effectively and analyzed the transcriptional adaptation and the changes of growth and genes expression profile by high-throughput RNA sequencing (RNA-Seq). Results: We found the SMG condition can enhance the bacterium growth, and 61 genes were differentially expressed in SMG conditions compared to that of NG condition among all the genes of P. g ATCC33277 by global gene expression analysis. These genes were involved in a wide range of biological processes and biological pathways, including modulation of DNA replication, recombination, and repair; energy metabolism; two-component system; one carbon pool by folate; microbial metabolism in diverse environments. Under the SMG 9 genes were up-regulated. Simultaneously 52 were down-regulated. Conclusion: Our study demonstrated changes in global gene expression under SMG condition. The DEGs were linked to 666 gene ontology (GO) terms. These findings provide a foundation for future studies on genetic and molecular mechanisms associated with oral bacteria changes on SMG condition, and may provide better safeguard for the astronaunts.