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An Electroporation Method to Transform Rickettsia spp. with a Fluorescent Protein-Expressing Shuttle Vector in Tick Cell Lines
Published on: October 11, 2022
Potential roles for regulatory oxygenases in rickettsial pathogenesis
Sanjeev K Sahni1, Elena Rydkina, Abha Sahni
1Hematology-Oncology Unit, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA. sanjeev_sahni@urmc.rochester.edu
Annals of the New York Academy of Sciences
|February 17, 2006
Summary
Spotted fever rickettsiae infections increase cyclooxygenase-2 (COX-2) and heme oxygenase-1 (HO-1) expression in endothelial cells. This response impacts vascular integrity and offers insights into rickettsial disease pathogenesis.
Area of Science:
- Vascular biology
- Infectious diseases
- Oxidative stress
Background:
- Oxidative stress and cellular defenses are implicated in vasculopathic rickettsioses.
- Rickettsia rickettsii infection induces heme oxygenase-1 (HO-1) in endothelial cells.
- HO-1 is crucial for vascular integrity and regulates the cyclooxygenase (COX) system.
Purpose of the Study:
- To investigate the expression of COX and HO isozymes during in vitro infection of endothelial cells (EC) with spotted fever group Rickettsia species.
- To understand the role of these enzymes in the pathogenesis of rickettsial diseases.
Main Methods:
- In vitro infection of endothelial cells with Rickettsia rickettsii and Rickettsia conorii.
- Quantitative mRNA expression analysis (RT-PCR) for COX-1 and COX-2.
- Western blot analysis for protein expression.
- Enzyme-linked immunosorbent assay (ELISA) for secreted products.
Main Results:
- Significant increase in COX-2 mRNA and protein expression in R. rickettsii and R. conorii infected EC.
- COX-1 expression remained unaffected.
- Enhanced secretion of 6-keto PGF(1alpha) and PGE(2).
- Increased expression of ferritin, a downstream product of HO-1, following infection.
Conclusions:
- Rickettsia infection upregulates COX-2 and HO-1 pathways in endothelial cells.
- These enzymatic responses are critical for host-pathogen interactions in rickettsioses.
- Further research into host cell regulation of these pathways is needed to elucidate rickettsial disease pathogenesis.
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