hrvatski

Utjecaj hidrokortizona na ekspresiju galektina-1 u staničnoj liniji ljudskih monocitnih stanica THP-1

Galectins are a family of lectins, with a high affinity for β -galactoside structures of glycoconjugates. Although the exact role of galectins is not yet fully clarified, their participation in the control of homeostasis, by modulating cell growth, regulating the cell cycle as well as by the induction or inhibition of apoptosis is confirmed. Galectin-1 was first in the galectin family to be discovered. Galectin-1 participates in the modulation of the immune response including homeostasis, T cell survival, inflammation and allergies, host-pathogen interactions but it also partakes in the development of cancer and its resistance towards the immune system. Steroidal anti-inflammatory drugs, a subgroup of substances with imunomodulatory effects, are often used in treating various diseases. They modulate signaling pathways and activity of transcription factors involved in the regulation of galectin-1 expression. Because of the frequent therapeutic application of glucocorticoids, we investigated the effects of a synthetic glucocorticoid hydrocortisone, applied in different therapeutic ranges, on the expression of galectin-1 in non-differentiated cells of human monocytic THP-1 cell-line during 72 hours of cultivation. Because hydrocortisone is not soluble in water, it was necessary to dissolve it in DMSO and thus, examine the solvent’ s effect on cell culture. Viable cells and the cell count were assessed with trypan blue exclusion dye and metabolic activity with MTS test. Both of the tests proved that DMSO has no effect on cells. The same methods were used to substantiate that hydrocortisone in concentrations 0, 1 µ M, 1 µ M, 5 µ M i 10 µ M has no cytotoxic effect on cells. After Western blotting the cell homogenates, a method of enhanced chemiluminescence was conducted to visualize actin and galectin-1 bands on the autoradiographic film. Actin is the constitutive cellular protein whose expression does not change under the influence of different chemical substances. The results of densitometric analysis of the bands are expressed as the relative surface of galectin-1/actin bands of the treated sample in relation to the relative surface galectin-1/actin bands of the control sample. Statistical analysis of the results showed that hydrocortisone in concentrations of 0.1 μ M, 1 μ M, 5 μ M and 10 μ M inhibits the expression of galectin-1 in THP-1 cells, and the percentage of inhibition increases with time of cell exposure to the hydrocortisone. The results obtained in this study represent a step in better understanding the effects of hydrocortisone as well as clarifying the mechanism of regulation of galectin-1 expression in the immune cells.

hidrokortizon; upala; galektin-1

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