Dataset Information

Gene expression profiles of Chlamydophila pneumoniae during the developmental cycle and iron depletion-mediated persistence.

ABSTRACT: The obligate intracellular, gram-negative bacterium Chlamydophila pneumoniae (Cpn) has impact as a human pathogen. Little is known about changes in the Cpn transcriptome during its biphasic developmental cycle (the acute infection) and persistence. The latter stage has been linked to chronic diseases. To analyze Cpn CWL029 gene expression, we designed a pathogen-specific oligo microarray and optimized the extraction method for pathogen RNA. Throughout the acute infection, ratio expression profiles for each gene were generated using 48 h post infection as a reference. Based on these profiles, significantly expressed genes were separated into 12 expression clusters using self-organizing map clustering and manual sorting into the "early", "mid", "late", and "tardy" cluster classes. The latter two were differentiated because the "tardy" class showed steadily increasing expression at the end of the cycle. The transcriptome of the Cpn elementary body (EB) and published EB proteomics data were compared to the cluster profile of the acute infection. We found an intriguing association between "late" genes and genes coding for EB proteins, whereas "tardy" genes were mainly associated with genes coding for EB mRNA. It has been published that iron depletion leads to Cpn persistence. We compared the gene expression profiles during iron depletion-mediated persistence with the expression clusters of the acute infection. This led to the finding that establishment of iron depletion-mediated persistence is more likely a mid-cycle arrest in development rather than a completely distinct gene expression pattern. Here, we describe the Cpn transcriptome during the acute infection, differentiating "late" genes, which correlate to EB proteins, and "tardy" genes, which lead to EB mRNA. Expression profiles during iron mediated-persistence led us to propose the hypothesis that the transcriptomic "clock" is arrested during acute mid-cycle.

SUBMITTER: Maurer AP

PROVIDER: S-EPMC1894823 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The obligate intracellular, gram-negative bacterium, Chlamydophila pneumoniae (Cpn), has impact as an acute and chronic disease-causing pathogen. Little is known about changes in the Cpn transcriptome during its biphasic developmental cycle (the acute infection) and persistence stages that are linked to chronic diseases. To analyze Cpn CWL029 gene expression, we designed a pathogen-specific oligo microarray and optimized the extraction method for pathogen RNA. Throughout the acute infection, ratio expression profiles for each gene were generated using 48 hours post infection as a reference. Based on these profiles, significantly expressed genes were separated into 12 expression clusters using SOM clustering and manually into the ‘early’, ‘mid’, ‘late’ and ‘tardy’ cluster classes. The latter two were differentiated because the ‘tardy’ class showed steadily increasing expression at the end of the cycle. The transcriptome of the Cpn elementary body (EB) and published EB proteomics data were compared to the cluster profile of the acute infection. We found an intriguing association between ‘late’ genes and genes coding for EB proteins, whereas ‘tardy’ genes were mainly associated with genes coding for EB mRNA. It has been published that iron depletion leads to Cpn persistence. We compared the gene expression profiles during iron depletion-mediated persistence with the expression clusters of the acute infection. This led to the finding that establishment of iron depletion-mediated persistence is more likely a mid-cycle arrest in development rather than a completely distinct gene expression pattern. Taken together, here we describe the Cpn transcriptome during the acute infection with ‘late’ genes correlating to EB proteins and ‘tardy’ genes to EB mRNA. Expression profiles during iron mediated-persistence led us to propose the hypothesis that the transcriptomic ‘clock’ is arrested during acute mid-cycle. Keywords: time course, iron, persistence, Chlamydia, Chlamydophila, pneumoniae, recovery, pathogen, life cycle, developmental cycle

Project description:Background & aimsGastric dysfunction in the elderly may cause reduced food intake, frailty, and increased mortality. The pacemaker and neuromodulator cells interstitial cells of Cajal (ICC) decline with age in humans, and their loss contributes to gastric dysfunction in progeric klotho mice hypomorphic for the anti-aging Klotho protein. The mechanisms of ICC depletion remain unclear. Klotho attenuates Wnt (wingless-type MMTV integration site) signaling. Here, we examined whether unopposed Wnt signaling could underlie aging-associated ICC loss by up-regulating transformation related protein TRP53 in ICC stem cells (ICC-SC).MethodsMice aged 1-107 weeks, klotho mice, APCΔ468 mice with overactive Wnt signaling, mouse ICC-SC, and human gastric smooth muscles were studied by RNA sequencing, reverse transcription-polymerase chain reaction, immunoblots, immunofluorescence, histochemistry, flow cytometry, and methyltetrazolium, ethynyl/bromodeoxyuridine incorporation, and ex-vivo gastric compliance assays. Cells were manipulated pharmacologically and by gene overexpression and RNA interference.ResultsThe klotho and aged mice showed similar ICC loss and impaired gastric compliance. ICC-SC decline preceded ICC depletion. Canonical Wnt signaling and TRP53 increased in gastric muscles of klotho and aged mice and middle-aged humans. Overstimulated canonical Wnt signaling increased DNA damage response and TRP53 and reduced ICC-SC self-renewal and gastric ICC. TRP53 induction persistently inhibited G1/S and G2/M cell cycle phase transitions without activating apoptosis, autophagy, cellular quiescence, or canonical markers/mediators of senescence. G1/S block reflected increased cyclin-dependent kinase inhibitor 1B and reduced cyclin D1 from reduced extracellular signal-regulated kinase activity.ConclusionsIncreased Wnt signaling causes age-related ICC loss by up-regulating TRP53, which induces persistent ICC-SC cell cycle arrest without up-regulating canonical senescence markers.

Dataset Information

Gene expression profiles of Chlamydophila pneumoniae during the developmental cycle and iron depletion-mediated persistence.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets