Apoptosis in HEp-2 cells infected with Ureaplasma diversum
Aline Teixeira Amorim1, Lucas Miranda Marques2,3, Angelita Maria Oliveira Gusmão Santos4
1Instituto Multidisciplinar em Saúde, Núcleo de Tecnologia em Saúde, Universidade Federal da Bahia, Vitória da Conquista, Brazil. aline.amorim@usp.br.
Background:
Bacterial pathogens have many strategies for infecting and persisting in host cells. Adhesion, invasion and intracellular life are important features in the biology of mollicutes. The intracellular location of Ureaplasma diversum may trigger disturbances in the host cell. This includes activation or inhibition of pro and anti-apoptotic factors, which facilitate the development of host damage. The aim of the present study was to associate U. diversum infection in HEp-2 cells and apoptosis induction. Cells were infected for 72hs with four U. diversum clinical isolates and an ATCC strain. The U. diversum invasion was analyzed by Confocal Laser Scanning Microscopy and gentamicin invasion assay. The apoptosis was evaluated using pro-apoptotic and anti-apoptotic gene expression, and FITC Annexin V/Dead Cell Apoptosis Kit.
Results:
The number of internalized ureaplasma in HEp-2 cells increased significantly throughout the infection. The flow cytometry analysis with fluorochromes to detect membrane depolarization and gene expression for caspase 2, 3 and 9 increased in infected cells after 24 hours. However, after 72 hours a considerable decrease of apoptotic cells was observed.
Conclusions:
The data suggests that apoptosis may be initially induced by some isolates in association with HEp-2 cells, but over time, there was no evidence of apoptosis in the presence of ureaplasma and HEp-2 cells. The initial increase and then decrease in apoptosis could be related to bacterial pathogen-associated molecular pattern (PAMPS). Moreover, the isolates of U. diversum presented differences in the studied parameters for apoptosis. It was also observed that the amount of microorganisms was not proportional to the induction of apoptosis in HEp-2 cells.
Insights
Ureaplasma diversum initially induces apoptosis in HEp-2 cells, but this effect diminishes over time, suggesting complex interactions between the bacteria and host cells. Different isolates showed varied impacts on apoptosis.
Area of Science:
- Microbiology
- Cell Biology
- Immunology
Background:
- Mollicutes like Ureaplasma diversum invade and persist within host cells.
- Intracellular U. diversum can disrupt host cell balance by altering apoptotic factors, leading to host damage.
- This study investigates the link between U. diversum infection and apoptosis induction in HEp-2 cells.
Purpose of the Study:
- To determine the association between Ureaplasma diversum infection and apoptosis in HEp-2 cells.
- To analyze the invasion capabilities of U. diversum clinical isolates and an ATCC strain.
- To evaluate the induction of apoptosis by U. diversum infection.
Main Methods:
- Infection of HEp-2 cells with U. diversum isolates for 72 hours.
- Analysis of U. diversum invasion using Confocal Laser Scanning Microscopy and gentamicin assay.
- Apoptosis evaluation via gene expression of apoptotic factors and FITC Annexin V/Dead Cell Apoptosis Kit.
Main Results:
- Significant increase in internalized Ureaplasma diversum within HEp-2 cells over time.
- Upregulation of pro-apoptotic genes (caspase 2, 3, 9) and membrane depolarization observed at 24 hours post-infection.
- A notable decrease in apoptotic cells occurred by 72 hours post-infection.
Conclusions:
- Ureaplasma diversum initially induces apoptosis in HEp-2 cells, but this effect is transient.
- The dynamic apoptosis response may involve bacterial pathogen-associated molecular patterns (PAMPs).
- Isolates of U. diversum exhibited varying effects on apoptosis, and bacterial load did not directly correlate with apoptosis induction.
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