Maria Kazakova

Synthesis and in vitro activity of platinum(II) complexes of two fluorenylspirohydantoins against a human tumour cell line

This paper presents a method for synthesis and cytotoxicity of new platinum(II) complexes of (9′-fluorene)-spiro-5-hydantoin (L1) and (9′-fluorene)-spiro-5-(2-thiohydantoin) (L2). The new obtained complexes were studied by elemental analysis: ultraviolet–visible, attenuated total reflection Fourier transform infrared (ATR-FTIR), and 1H- and 13C-NMR for Pt(II) compounds and additionally Raman spectroscopy for free ligands. Based on the experimental data, the most probable structure of the complexes is suggested. In the present study, we have examined cytotoxic activity of (9′-fluorene)-spiro-5-hydantoin (L1) and (9′-fluorene)-spiro-5-(2-thiohydantoin) (L2) and their Pt(II) complexes on the retinoblastoma cell line WERI-Rb-1.

YKL-40 and cytokines - a New Diagnostic Constellation in Rheumatoid Arthritis?

Abstract Background: Rheumatoid arthritis (RA) causes chronic inflammation and alteration of articular tissue and joints. The pathogenesis of the disease remains unclear although it is known that proinflammatory cytokines play a major role in its induction. YKL-40 is a chitinase-like glycoprotein produced by activated macrophages, neutrophils, arthritic chondrocytes and cancer cells. It has been shown that YKL-40 is implicated in tissue remodeling, angiogenesis and inflammation. Aim: to investigate serum and synovial YKL-40 levels in relation to IL-1β, TNF-α, and IL-6 in RA patients. Materials and methods: Serum and synovial concentrations of YKL-40, TNF-α, IL- 6, and IL-1β were determined by ELISA in 39 patients (mean age 53.18 ± 16.54 yrs) with active RA. Results: Serum YKL-40 levels were increased in all patients. The highest levels were found in synovial fluid (P<0.01). Our study showed a strong association between serum and synovial levels of YKL-40 and serum TNF-α and IL-1 β (P<0.05). Conclusion: This is the first study finding a significant correlation between serum TNF-α and IL-1β and YKL-40 in active RA. We suggest that these molecules together might play a dominant role in the pathogenesis and disease activity and could possibly serve as a new diagnostic constellation in rheumatoid arthritis.

Correlation between protein YKL-40 and ultrasonographic findings in active knee osteoarthritis

The aim of our study was to analyze the level of the glycoprotein YKL-40 in patients with active knee osteoarthritis (OA) and to search possible correlations with local inflammation and ultrasound (US) findings. MATERIAL AND METHODS A prospective study with fifty consecutive patients with active knee OA (diagnosed based on the American College of Rheumatology criteria for OA with radiographic confirmation) was performed. Concentrations of YKL-40 in serum and synovial fluid were measured by ELISA. US examinations - Gray scale (GS) US and Power Doppler (PD) US - of the knee was performed according to international guidelines. The suprapatellar, medial and lateral parapatellar recesses were scanned in each knee to evaluate synovial hypertrophy and vascularization. RESULTS Forty women (mean age 61.50±11.33 years old) and 10 men (aged 68.50±6.60 years old) were enrolled. We found that the synovial level of the glycoprotein (237.80±104.08 ng/ml) was significantly higher compared to the serum concentration (112.83±60.61 ng/ml, p<0.001). The serum concentration in OA patients was higher comparing with age-matched healthy controls (84.19±11.39 ng/ml) (p<0.05). A statistically significant association between YKL- 40 in synovial fluid and serum levels was shown. We determined a moderately positive linear relationship between the synovial level of the glycoprotein and the serum concentration. No association between the levels of inflammatory markers - erythrocyte sedimentation rate and C-reactive protein - and YKL-40 concentrations was detected. Our study revealed a strong relationship between YKL-40 in synovial fluid and GS US and feeble with PD US. YKL-40 correlated with inflammatory activity in knee joints and neovascularization detected by US. CONCLUSIONS YKL-40 is involved in the pathogenesis of OA synovitis. Evaluation of YKL-40 levels in parallel with US might provide more sensitive and reliable information for the diagnosis and understanding of OA.

LAMP-1 gene is overexpressed in high grade glioma

High‐grade gliomas (HGG) are the most frequent brain tumors in adults. Glioblastoma multiforme (GBM) is their most aggressive form resistant to therapy. It was shown that inhibition of autophagy reduced GBM development and autophagy interfering agents are regarded as a new strategy to fight glioma cells. The lysosome‐associated membrane proteins (LAMPs) display differential expression particularly in cancer. There are few data on their expression and especially on their molecular profile. The aim of the present study is to investigate the expression of LAMP‐1 and LAMP‐2 genes and proteins in HGG. Newly diagnosed patients with HGG and healthy controls were examined by immunohistochemistry and qPCR for both protein and mRNA levels of LAMP‐1 and LAMP‐2. The transcriptional activity of LAMP‐1 in HGG was significantly higher compared to normal brain and to LAMP‐2. The two glycoproteins were detected in the cytosol of tumor cells with varying intensity, LAMP‐1 showing again enhanced expression. In conclusion, novel data on LAMP‐1 overexpression in HGG are presented suggesting involvement of this gene and protein in cell adhesion and tumor progression. These findings might help the elucidation of the complex biological role of the multifunctional LAMPs proteins and to predict novel therapeutic targets in lysosomes.

YKL‐40: The Search for New Biomarkers in Rheumatoid Arthritis

There is a need for biomarkers to detect early joint inflammation and destruction of cartilage in different types of arthritis. YKL‐40, a 39 kDa heparin‐ and chitin‐binding secreted glycoprotein (also known as human cartilage gp39), has been recently discovered. Its exact biological function is still unclear. Specific receptors for YKL‐40 have not been identified yet. The clinical significance of YKL‐40 as a biomarker is discussed in different aspects. High level of YKL‐40 is found in various human i`nflammatory and neoplastic diseases. We present a review highlighting the information available on YKL‐40 and its significance in inflammatory joint diseases, like rheumatoid arthritis (RA). We also report original personal data on the topic concerning YKL‐40 levels in serum and synovial fluid of patients with RA in comparison with ultrasonographic parameters and cytokine levels. The findings suggest that YKL‐40 might be implicated in the pathogenesis of the disease and could indicate the level of joint inflammation.

A comparative study of LAMPs and YKL-40 tissue expression in glial tumors.

ABSTRACT INTRODUCTION: YKL-40 is a glycoprotein believed potentially to be a marker of various pathological processes. High levels of YKL-40 have been found in cancer and chronic infl ammatory diseases. The function of the glycoprotein is not completely known yet. A possible involvement in angiogenesis and tumor aggressiveness is supposed. Lysosome-associated membrane glycoproteins (LAMP) 1 and 2 are highly conserved proteins with still undefi ned biological functions. There is evidence that they are implicated in autophagy, angiogenesis and tissue remodeling. AIM: The aim of the present study was to investigate the potential relationship between the tissue expression of YKL-40, LAMP-1 and LAMP-2 in glial tumors. MATERIAL AND METHODS: LAMPs and YKL-40 expression was determined by immunohistochemistry in 36 glial tumors. A morphometric analysis of the intensity of tissue expression was performed with the Quick-photo Micro 2.3. system. Area (μm), perimeter (μm), and expression level (%) of the three glycoproteins were calculated. RESULTS: LAMPs were found on cell membranes of glial and endothelial cells, while YKL-40 was detected in the cytoplasm of these cells. Intensive immunohistochemical reaction was present in tumor cells. LAMP-2 showed a more intensive staining compared to LAMP-1. CONCLUSION: We present the fi rst comparative study of YKL-40 and LAMPs in astroglial tumors. The relationship between the expression of the three glycoconjugates indicates a possible participation in the processes of angiogenesis and tissue remodeling during tumor development РЕЗЮМЕ ВВЕДЕНИЕ: YKL-40 представляет собой гликопротеин, который считается потенциальным маркером при патологических процессах. Высокие уровни YKL-40 установлены при ряде опухолевых и хронических заболеваний. Несмотря на то, что конкретные функции гликопротеина все еще неизвестны, предполагается его участие в ангиогенезисе и в опухолевой агрессивности. Лизосомно-ассоциированные мембранные протеины (LAMPs) 1 и 2 представляют высоко консервативные белки с дискутабильными функциями. Имеются доказательства об их участии в процессах как аутофагия, ангиогенезис и тканевое ремоделирование. ЦЕЛЬ: Исследовать потенциальную связь между тканевой эспрессией YKL-40, LAMP-1 и LAMP-2 при глиальных опухолях. МАТЕРИАЛ И МЕТОДЫ: Экспрессия LAMPs и YKL-40 детектирована через иммуногистохимический анализ в 36 глиальных опухолях. Проведены морфометрическое исследование и анализ тканевой экспрессии YKL-40 с помощью компьютерной системы Quick-patho Micro 2.3. Вычислены площадь (μm2), периметр (μm) и экспрессия (%) трех гликопротеинов. РЕЗУЛЬТАТЫ: Лизосомные белки позитивируются на клеточную мембрану глиальных и эндотелиальных клеток, в то время как YKL- 40 локализован в их цитоплазме. Интенсивная иммуногистохимическая реактивность наблюдается в опухолевых клетках. При LAMP-2 отчитывается более демонстративная экспрессия по сравнению с LAMP-1. ЗАКЛЮЧЕНИЕ: Впервые представлены данные о сравнительном иммуногистохимическом исследовании YKL-40, LAMP-1 и LAMP-2 при глиальных опухолях. Сходство между экспрессией трех белков предполагает их участие в процессах ангиогенезиса и в процессах тканевого ремоделирования во время опухолевого развития.

YKL-40 IN HEALTHY SUBJECTS

ABSTRACT YKL-40 is a plasma protein, belonging to the chitinase protein family, but has no chitinase activity. It is expressed and secreted by macrophages, chondrocytes, activated neutrophils, differentiated monocytes, vascular smooth muscle cell and cancer cells. The objective of the present study was to determine serum YKL-40 levels in healthy subjects and to develop a valid reproducible enzyme-linked immunosorbent assay. Serum YKL-40 concentrations were determined by a two-site, sandwich-type, enzyme-linked immunosorbent assay (ELISA) in 10 healthy female volunteers aged 18–50. Our investigation show a mean value 41,11 (20–59) ng/ml of serum YKL-40 in healthy women. We determined that the correlation between protein level and age is feeble, but positive. Our study is the first in Bulgaria to measure serum YKL-40 level in healthy subjects. Elucidation of YKL-40 functions in normal and pathologic processes is an important objective offuture analyses.