Abstract
Purpose :
Glycosaminoglycans (GAGs) are linear polysaccharide chains covalently bounded to core proteins, which form proteoglycans (PGs). Their synthesis is performed by a wide number of genes. PGs are essential in the control of multiple biological processes but also in pathological development of eye infectious diseases. Both Gram-positive and Gram-negative bacteria are capable of producing membrane vesicles (MVs), which typically range from 25 to 350 nm in diameter. MVs cargo contains proteins, virulence factors, nucleic acids and other metabolites. Therefore, bacterial MVs are able to mediate host invasion during an infectious process. In this work, we analyse if MVs in contact with human corneal epithelium cell (HCE) cultures would produce changes in the expression of PGs
Methods :
MVs were isolated and purified from bacterial cultures of Staphylococcus epidermidis and Pseudomonas aeruginosa by filtration and ultracentrifugation techniques. Once obtained, they were added to HCE cultures. Afterwards, the variation in the transcription levels of the genes encoding PGs was analysed by means of RT-qPCR
Results :
The expression levels of 95 genes that encode PG and GAG chains were studied. S. epidermidis MVs addition altered the expression of 7 genes, being 4 overexpressed and 3 underexpressed. However, the addition of P. aeruginosa vesicles to HCE resulted in the alteration of the transcription of 24 genes, 15 overexpressed and 9 underexpressed
Conclusions :
Contact of MVs with HCE cells has proven to have an effect on the transcription of genes involved in the synthesis of PGs and GAGs, essential molecules in vesicle function. P. aeruginosa is a commonly known pathogen whose vesicles are capable of producing alterations in 25% of PG and GAG genes. In the case of S. epidermidis, considered a commensal microorganism but also responsible for infectious diseases, its vesicles also cause modifications of the expression in 7% of genes. Both S. epidermidis and P. aeruginosa vesicles produce mainly an overexpression of those genes related to the modification of GAGs, while those involved in the synthesis of core proteins are mostly underexpressed
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.