Dihydrolipoic but not alpha-lipoic acid affects susceptibility of eukaryotic cells to bacterial invasion

• Published in: Biochemical and biophysical research communications 2015-05, Vol.460 (3), p.697-702
• Main Authors: Bozhokina, Ekaterina, Khaitlina, Sofia, Gamaley, Irina
• Format: Article
• Language: English
• Subjects: Antioxidants; Bacterial invasion; Base Sequence; beta Catenin - metabolism; Cadherins - metabolism; Cell Line, Tumor; Dihydrolipoic acid; DNA Primers; Escherichia coli; Escherichia coli - pathogenicity; Eukaryotic Cells - microbiology; Humans; Real-Time Polymerase Chain Reaction; Serratia; Serratia - pathogenicity; Serratia grimesii; Thioctic Acid - analogs & derivatives; Thioctic Acid - pharmacology; α-Lipoic acid
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2015.03.092

Sensitivity of eukaryotic cells to facultative pathogens can depend on physiological state of host cells. Previously we have shown that pretreatment of HeLa cells with N-acetylcysteine (NAC) makes the cells 2–3-fold more sensitive to invasion by the wild-type Serratia grimesii and recombinant Escherichia coli expressing gene of actin-specific metalloprotease grimelysin [1]. To evaluate the impact of chemically different antioxidants, in the present work we studied the effects of α-Lipoic acid (LA) and dihydrolipoic acid (DHLA) on efficiency of S. grimesii and recombinant E. coli expressing grimelysin gene to penetrate into HeLa and CaCo cells. Similarly to the effect of NAC, pretreatment of HeLa and CaCo cells with 0.6 or 1.25 mM DHLA increased the entry of grimelysin producing bacteria by a factor of 2.5 and 3 for the wild-type S. grimesii and recombinant E. coli, respectively. In contrast, pretreatment of the cells with 0.6 or 1.25 mM LA did not affect the bacteria uptake. The increased invasion of HeLa and CaCo cells correlated with the enhanced expression of E-cadherin and β-catenin genes, whereas expression of these genes in the LA-treated cells was not changed. Comparison of these results suggests that it is sulfhydryl group of DHLA that promotes efficient modification of cell properties assisting bacterial uptake. We assume that the NAC- and DHLA-induced stimulation of the E-cadherin-catenin pathway contributes to the increased internalization of the grimelysin producing bacteria within transformed cells. •Impact of antioxidants on invasion of Serratia grimesii into eukaryotic cells was studied.•α-Lipoic acid did not change penetration of S. grimesii and recombinant Escherichia coli.•Dihydrolipoic acid increased penetration of HeLa and CaCo cell by a factor of 2–3.•The higher invasion correlated with enhanced expression of E-cadherin and β-catenin.•The higher invasion correlated with increased amount of E-cadherin.