Temporal Transcriptome Analysis Suggests Modulation of Key Pathways and Hub Genes in a Mice Model of Multi-Drug Resistant (MDR) Pseudomonas aeruginosa Endophthalmitis

Abstract

Purpose

Increasing incidence of multidrug-resistant Pseudomonas aeruginosa (MDR-PA) causing endophthalmitis challenges our ability to manage this vision-threatening condition. In this study, temporal dynamics of immune response in a mouse model of MDR-PA endophthalmitis was investigated by whole transcriptome analysis.

Methods

C57BL/6 mice were infected with MDR-PA and antibiotic susceptible (S-PA) clinical strains and disease severity were monitored at 6 and 24-h postinfection (p.i), following which eyeballs were enucleated. Microarray analysis was performed using SuperPrint G3 Mouse Gene Expression v2 chip and the differential gene expression analysis was performed with limma package in R (v4.0.0.)/Bioconductor (v3.11).

Results

Histopathological analysis revealed a significant difference in retinal architecture and vitreous infiltrates at 6 and 24 h. In comparison to S-PA, MDR-PA revealed altered expression of 923 genes at 6 h and 2220 genes at 24 h. Further, 23 and 76% of these altered genes and its downstream interacting proteins showed time-specific expression (6 and 24 h respectively), indicating their association with disease progression. At 24 hours, MDR-PA induced endophthalmitis showed aberrant immune response with the enrichment inflammasome signalling, dysregulated ubiquitination, complement cascade, MMPs NF-κβ and IL-1 signalling.

Conclusion

The rapid development of transcriptional differences between the two-time points reveals that distinct genes contribute to disease severity. The results from this study highlighted a link between innate and adaptive immune responses and provided novel insights in the pathogenesis of MDR-PA endophthalmitis by extending the number of molecular determinants and functional pathways that underpin host-associated damage.

Keywords:

• Pseudomonas aeruginosa
• endophthalmitis
• multi-drug resistance
• transcriptomics
• murine model

Acknowledgements

The authors thank Mr Sreedhar Rao Boyenpally, Ophthalmic Pathology LVPEI, for providing cryosections of retina and Prof. R Srivatsan, IBAB, Bangalore for verifying the microarray data.

Ethical approval

The animal study was reviewed and approved by the Institutional Animal Ethics Committee (IAEC), Sipra Labs, Hyderabad, India (SLL-PCT-IAEC/20-21/B) dated 08/20/2020.

Author contributions

Conceptualization: JJ and PN, Methodology: PN, Software: PN. Validation: PN and JJ. Resources: JJ. Writing—original draft preparation: PN. Writing—review and editing: JJ. Project administration: JJ. Funding acquisition: JJ.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Raw data were generated at Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute. Derived data supporting the findings of this study are available from the corresponding author Dr. Joveeta on request.

Additional information

Funding

This work was supported by the Hyderabad Eye Research Foundation (HERF) and DBT-grant (BT/PR32404/MED/30/2136/2019). We thank the ICMR SRF extramural fellowship for the funding support to PN (OMI-fellowship/10/2020-ECD-I).