Joanna Orchel

Immunolocalization and Expression of Kallistatin and Tissue Kallikrein in Human Inflammatory Bowel Disease

The distribution of tissue kallikrein (TK) and its plasma inhibitor, kallistatin in plasma and intestinal tissue, was studied in patients with active ulcerative colitis (UC) and Crohns disease (CD). TK was localized to goblet cells and kallistatin to epithelial cells of normal human intestine. Both proteins are visualized in macrophages inside granulomas in CD as well as in plasmocytes in both CD and UC. Intestinal tissue kallikrein (ITK) and kallistatin are significantly decreased in inflamed intestine compared to noninflammatory controls. TK mRNA is significantly decreased in intestinal biopsy samples from active UC patients compared with inactive patients or controls. Immunoreactive TK is present in plasma in very low concentrations in patients and did not differ in normal subjects. Plasma kallistatin was significantly decreased in patients with active disease compared to normal controls. Our data suggest that release of TK during inflammation plays a role in inflammatory bowel disease.

Aldehydic lipid peroxidation products in human brain astrocytomas

Among mediators of oxidative stress, highly reactive secondary aldehydic lipid peroxidation products can initiate the processes of spontaneous mutagenesis and carcinogenesis and can also act as a growth-regulating factors and signaling molecules. We explored whether these aldehydes and histone H3 mRNA levels could serve as biomarkers of malignancy and predictive factor in human brain astrocytomas. Histone H3 mRNA, a biomarker of cellular proliferation, was analyzed by QRT-PCR (TaqMan). Aldehydic lipid peroxidation products were determined as their dinitrophenylhydrazone derivatives in specimens obtained from 26 adult patients with brain astrocytomas. RP-HPLC with diode array detector and MSMS spectrometer were used for the analysis. H3 mRNA, 2-hydroxyhexanal, and 4-hydroxynonenal levels were higher in high-grade astrocytomas compared to low-grade astrocytomas and showed negative correlation with survival. Higher levels of 2-hydroxyhexanal and 4-hydroxynonenal, and lower levels of n-hexanal were associated with poorer patient prognosis. Our data suggest that tissue concentrations of aldehydic lipid peroxidation products can assist grading and predicting the clinical outcome in patients with astrocytic brain tumors. Possibly, this parameter will enhance optimal selection of patients for individualized treatment protocols, tailored to unique biochemical and molecular profile of the tumor.

The Influence of Chain Microstructure of Biodegradable Copolyesters Obtained with Low-Toxic Zirconium Initiator to In Vitro Biocompatibility

Because of the wide use of biodegradable materials in tissue engineering, it is necessary to obtain biocompatible polymers with different mechanical and physical properties as well as degradation ratio. Novel co- and terpolymers of various composition and chain microstructure have been developed and applied for cell culture. The aim of this study was to evaluate the adhesion and proliferation of human chondrocytes to four biodegradable copolymers: lactide-coglycolide, lactide-co-ε-caprolactone, lactide-co-trimethylene carbonate, glycolide-co-ε-caprolactone, and one terpolymer glycolide-colactide-co-ε-caprolactone synthesized with the use of zirconium acetylacetonate as a nontoxic initiator. Chain microstructure of the copolymers was analyzed by means of 1H and 13C NMR spectroscopy and surface properties by AFM technique. Cell adhesion and proliferation were determined by CyQUANT Cell Proliferation Assay Kit. After 4 h the chondrocyte adhesion on the surface of studied materials was comparable to standard TCPS. Cell proliferation occurred on all the substrates; however, among the studied polymers poly(L-lactide-coglycolide) 85 : 15 that characterized the most blocky structure best supported cell growth. Chondrocytes retained the cell membrane integrity evaluated by the LDH release assay. As can be summarized from the results of the study, all the studied polymers are well tolerated by the cells that make them appropriate for human chondrocytes growth.

Evaluation of Melanogenesis in A-375 Cells in the Presence of DMSO and Analysis of Pyrolytic Profile of Isolated Melanin

The increase of a skin malignant melanoma (melanoma malignum) incidence in the world has been observed in recent years. The tumour, especially in advanced stadium with metastases, is highly resistant to conventional treatment. One of the strategies is to modulate melanogenesis using chemical compounds. In this study, the processes of differentiation and melanogenesis induced by dimethylsulfoxide (DMSO) in human melanoma cells (A-375) were investigated. Natural melanin isolated from A-375 melanoma cell line treated with 0.3% DMSO was analyzed by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) method. The products derived from pheomelanin have not been stated in the pyrolytic profile of analyzed melanin. Within all products derived from eumelanins, 1,2-benzenediol has been predominated. It has been shown that in the melanoma cells stimulated with 0.3% and 1% DMSO, the increase of transcriptional activity of the tyrosinase gene took place. It was accompanied by the rise of tyrosinase activity and an accumulation of melanin in the cells. The better knowledge about the structure of melanins can contribute to establish the uniform criteria of malignant melanoma morbidity risk.

Evaluation of melanogenesis in A-375 melanoma cells treated with 5,7-dimethoxycoumarin and valproic acid

Malignant melanoma (melanoma malignum) is one of the most dangerous types of tumor. It is very difficult to cure. In recent years, a lot of attention has been given to chemoprevention. This method uses natural and synthetic compounds to interfere with and inhibit the process of carcinogenesis. In this study, a new treatment strategy was proposed consisting of a combination of 5,7-dimethoxycoumarin (DMC), an activator of melanogenesis, and valproic acid (VPA), a well-known drug that is one of the histone deacetylase inhibitors (HDACis). In conjunction with 1 mM VPA, all of the tested concentrations of DMC (10–150 μM) significantly decreased the proliferation of A-375 cells. VPA and DMC also induced the synthesis of melanin and the formation of dendrite and star-shaped cells. Tyrosinase gene expression and tyrosinase activity significantly increased in response to VPA treatment. Pyrolysis with gas chromatography and mass spectrometry (Py-GC/MS) was used to investigate the structure of the isolated melanin. This showed that the quantitative and qualitative components of melanin degradation products are dependent on the type of applied melanogenesis inductor. Products derived from eumelanin were detected in the pyrolytic profile of melanin isolated from A-375 cells stimulated with DMC. Thermal degradation of melanin isolated from melanoma cells after exposure to VPA or a mixture of VPA and DMC revealed the additional presence of products derived from pheomelanin.