Chlamydia Manipulates Infected Cells' Powerhouse to Thrive

Scientists have identified a mechanism with whichChlamydia trachomatiscontrols the mitochondria, thereby preventing the cell from triggering programmed cell death.

In a previous study, the investigative team showed that chlamydia disables the tumor suppressor protein p53 in infected cells and initiates the DNA repair process. When p53 is blocked, the bacteria prevent the cell from knocking itself out, thereby gaining time for replication.

For the current study published inJournal ofCell Biology, the investigators took a closer look at the mitochondria, which play a crucial role in energy supply and programmed cell death. Lead investigator Thomas Rudel said he sees strong evidence that chances in the architecture and dynamics are closely related to the cells’ general metabolic processes.

The investigators examined microRNAs (miRNAs) using high-throughput sequencing to study in-depth how a chlamydia infection impacts the miRNA expression of the infected cell. Most interestingly, the results of the study showed that there was an increased production of miR-30c-5p microRNA. According to the authors, bacteria benefit from high concentrations of these tiny RNA molecules.

“They cause the tumor suppressor protein to be downregulated permanently,” Rudel said.

When miR-30c are blocked, it causes issues for chlamydia because the cell increases its production of the protein Drp1, which fragments the mitochondria in cells under stress. When the concentration increases, so do the stress-related mitochondrial division rates, increasing the infected cell’s chance of survival.

Chlamydial growth is significantly inhibited by fragmented mitochondria that supply less energy and starve the pathogens.

Chlamydia is the most common sexually transmitted disease worldwide. Depending on age, up to 10% of the global population is estimated to be infected with the bacteria. When left untreated, the infection can cause blockage in the fallopian tubes that can result in tubal pregnancy or infertility.