ABSTRACT
AIM:To evaluate the effect of mycoplasma on the rRNA composition of mature ribosomes in human cell lines.METHODS:We isolated ribosome nascent-chain complex ( RNC) from multiple mycoplasma-positive-negative human cell lines.RNC-RNA was acquired from each cell line through RNA extraction, followed by agarose gel separation, fluorescent visualization and gray-scale value measurements on the rRNA bands.Western blot analysis was performed to in-vestigate the MAPK pathway alterations.RESULTS:In various human cell lines derived from different tissues, we found that as compared with mycoplasma-negative cells, mycoplasma-positive cells showed aberrant RNC-rRNA band patterns, featured by the decreases in 28S and 18S eukaryotic rRNAs and the increases in 16S and other unknown prokaryotic rRNAs.When cultured without ciprofloxacin, mycoplasma-negative HBE cells acquired mycoplasma contamination as ob-served with such characteristic abnormal rRNA bands.The ciprofloxacin treatment was able to recover the RNC-rRNA bands of the mycoplasma-contaminated cells to the normal pattern.The results of Western blot analysis on total and phos-phorylated proteins indicated that p38 pathway was significantly deactivated in mycoplasma-infected A549 cells, while ERK1/2 pathway was not significantly altered.CONCLUSION:Mycoplasma contamination severely alters the RNC-rRNA composition via p38 MAPK pathway, thus seriously impacting on the host cell translational behaviors.