Heme Oxygenase-1 May Affect Cell Signalling via Modulation of Ganglioside Composition.

Heme oxygenase 1 (Hmox1), a ubiquitous enzyme degrading heme to carbon monoxide, iron, and biliverdin, is one of the cytoprotective enzymes induced in response to a variety of stimuli, including cellular oxidative stress. Gangliosides, sialic acid-containing glycosphingolipids expressed in all cells, are involved in cell recognition, signalling, and membrane stabilization. Their expression is often altered under many pathological and physiological conditions including cell death, proliferation, and differentiation.

Glycosphingolipid profile of the apical pole of human placental capillaries: the relevancy of the observed data to Fabry disease.

A series of six full-term placentas and umbilical cords were examined using the in situ detection of globotriaosylceramide (Gb3Cer), GM1 ganglioside (GM1), GM3 ganglioside (GM3), cholesterol and caveolin 1. Immunohistochemical study showed uniform distinct staining of the apical membrane of villous capillary endothelial cells for Gb3Cer, GM1, GM3 and cholesterol. There was also a strong signal for caveolin 1.

Photodynamic therapy of nonmelanoma skin cancer with topical hypericum perforatum extract--a pilot study.

Hypericin, the photoactive compound of Hypericum perforatum, is probably the most powerful photosensitizer found in nature. This compound has shown high potency in the photodynamic treatment of tumor cells. However, there is only limited knowledge regarding the photodynamic effect of hypericin on nonmelanoma skin cancer cells.

Preformed STAT3 transducer complexes in human HepG2 cells and rat hepatocytes.

Interleukin 6 (IL-6) is a pleiotropic cytokine that mediates a variety of functions, including induction of the acute-phase response in hepatocytes. IL-6 initiates its action by binding to its cell surface receptor, followed by activation of Janus kinases and tyrosine phosphorylation of the signal transducer and transcription factor (STAT) 3. Although it has been suggested that cholesterol- and sphingolipid-enriched membrane domains, called lipid rafts, and caveolin are involved in this process, their roles in the earliest stages of IL-6-mediated signaling are far from being understood.

Estrogen-induced cholestasis results in a dramatic increase of b-series gangliosides in the rat liver.

Hepatic ganglioside composition was investigated in normal and cholestatic Wistar rats. Cholestasis was induced by 17alpha-ethinylestradiol (EE; 5 mg/kg body weight s.c.

Changes in GM1 ganglioside content and localization in cholestatic rat liver.

(Glyco)sphingolipids (GSL) are believed to protect the cell against harmful environmental factors by increasing the rigidity of plasma membrane. Marked decrease of membrane fluidity in cholestatic hepatocytes was described but the role of GSL therein has not been investigated so far. In this study, localization in hepatocytes of a representative of GSL, the GM1 ganglioside, was compared between of rats with cholestasis induced by 17alpha-ethinylestradiol (EE) and vehicle propanediol treated or untreated animals.

Exogenous administration of gangliosides inhibits Fc epsilon RI-mediated mast cell degranulation by decreasing the activity of phospholipase C gamma.

Gangliosides released from tumor cells, as well as administered exogenously, suppress the immune responses by largely unknown mechanisms. We show here that a pretreatment of rat basophilic leukemia cells with isolated brain gangliosides inhibited the release of preformed secretory mediators from cells activated via FcepsilonRI but not Thy-1 glycoprotein. Exogenously administered gangliosides also affected the cell-substrate adhesion and the levels of polymeric filamentous actin in Ag-activated cells.