Porphyromonas gingivalis LPS and Actinomyces naeslundii Conditioned Medium Enhance the Release of a Low Molecular Weight, Transcriptionally Active, Fragment of Glycogen Synthase-3 Kinase in IMR-32 Cell Line.
J Alzheimers Dis Rep
; 8(1): 1055-1067, 2024.
Article
em En
| MEDLINE
| ID: mdl-39114545
ABSTRACT
Background:
Glycogen synthase-3 kinase (GSK3) is one of the major contributors of tau hyperphosphorylation linked to neurofibrillary tangles in Alzheimer's disease (AD).Objective:
To determine a mechanism of GSK-3ß activation by two periodontal bacteria consistently confirmed in AD autopsied brains.Methods:
Porphyromonas gingivalis FDC381 and Actinomyces naeslundii ATCC10301 conditioned media were collected. IMR-32 cells were challenged for 48âh with the conditioned media alongside P. gingivalis (ATCC33277) ultrapurified lipopolysaccharide (LPS) designated Pg.LPS under established cell culture conditions either alone or combined. Gene expression and protein analyses for GSK-3ß were carried out.Results:
qPCR demonstrated that GSK-3ß gene was overexpressed in IMR-32 cells treated with Pg.LPS with a 2.09-fold change (pâ=â0.0005), while A. naeslundii treated cells demonstrated 1.41-fold change (pâ=â0.004). Western blotting of the cells challenged with Pg.LPS (pâ=â0.01) and A. naeslundii conditioned medium (pâ=â0.001) demonstrated the 37 kDa band for each treatment with variable intensity across the medium control. Immunohistochemistry with the GSK-3ß of the IMR-32 cells challenged with Pg.LPS and A. naeslundii alone demonstrated cytoplasmic and nuclear localization.Conclusions:
Exposure to various bacterial factors upregulated the gene expression of GSK-3ß. Western blotting for GSK-3ß confirmed the presence of the cleaved fragment by Pg.LPS (37âkDa band pâ=â0.01) and A. naeslundii conditioned medium (37âkDa band pâ=â0.001). Immunostaining demonstrated both cytoplasmic and nuclear localization of GSK-3ß. Therefore, Pg.LPS and an unknown factor from the A. naeslundii conditioned medium mediated GSK-3ß activation via its transcriptionally active, cleaved, fragment. These virulence factors in the body appear to be detrimental to brain health.
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Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article