YKL-40, also known as human cartilage glycoprotein 39, is a member of the "mammalian chitinase-like proteins" family without chitinase activity. Increased serum concentrations are associated with inflammatory processes and several types of cancer. In this study, we evaluated YKL-40 levels in serum and synovial fluid of patients with rheumatoid arthritis in comparison with the ultrasonographic findings. YKL-40 levels were measured by enzyme-linked immunosorbent assay in 25 patients with active rheumatoid arthritis and in 40 healthy subjects. B mode and power Doppler were performed to determine synovial thickening and vascularization. Serum YKL-40 level in patients was significantly higher than the concentration in healthy controls (P < 0.01). In patients with rheumatoid arthritis, the level of the glycoprotein in synovial fluid was remarkably elevated compared to the serum level (P = 0.003). The B mode and power Doppler scores correlated to YKL-40 in serum and synovial fluid (P = 0.07). Serum YKL-40 levels were related positively to serum markers of inflammation such as C-reactive protein (P = 0.004) and erythrocyte sedimentation rate (P = 0.003). This study is the first to demonstrate a relationship between YKL-40 levels and ultrasonographic examinations in Bulgarian patients with rheumatoid arthritis. The findings suggest that YKL-40 might be implicated in the pathogenesis of the disease and could indicate the level of joint inflammation.

Neurodegenerative diseases comprise a large number of disorders with high impact on human health. Neurodegenerative processes are caused by various etiological factors and differ in their clinical presentation. Neuroinflammation is widely discussed as both a cause and a consequence in the manifestation of these disorders. The interplay between the two entities is considered as a major contributor to the ongoing disease progression. An attentive search and implementation of new and reliable markers specific for the processes of inflammation and degeneration is still needed. YKL-40 is a secreted glycoprotein produced by activated glial cells during neuroinflammation. Neuron-specific enolase (NSE), expressed mainly by neuronal cells, is a long-standing marker for neuronal damage. The aim of this review is to summarize, clarify, and evaluate the potential significance and relationship between YKL-40 and NSE as biomarkers in the monitoring and prognosis of a set of neurological diseases, such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and multiple sclerosis. YKL-40 appears to be a more reliable biomarker in neurological diseases than NSE. The more prominent expression pattern of YKL-40 could be explained with the more obvious involvement of glial cells in pathological processes accompanying each neurodegenerative disease, whereas reduced NSE levels are likely related to low metabolic activity and increased death of neurons.

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.

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There is a need of biomarkers to detect early joint inflammation and destruction of cartilage in different types of arthritis. YKL-40, a 39 kD heparin-and chitin-binding secreted glycoprotein (also known as cartilage gp39), was 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 was found in various human diseases associated with inflammatory and neoplastic processes. The review highlights the information available about YKL-40 and its significance in inflammatory joint diseases. We suggest that this glycoprotein might have a promising value as a novel biomarker and could provide additional evidence for inflammation activity in different types of arthritis.

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.

This work describes a method for synthesis, as well as in vitro antiproliferative and antibacterial investigation of 3-methyl-9'-fluorenespiro-5-hydantoin. The structure of the substituted fluorenylspirohydantoin derivative was verified by UV-Vis, FT-IR, Raman, 1 H NMR and 13 C NMR spectroscopy, and by using a combination of 2D NMR experiments, which included 1 H-1 H COSY, HMQC and HMBC sequences. The geometry of the compound was optimized by the B3LYP density functional with 6-31G(d) basis set and the 1 H and 13 C NMR spectra were predicted with the HF/6-31G(d) calculations at the optimized geometry. The anticancer activity of the 3-methyl-9'-fluorenespiro-5-hydantoin was determined in suspension cell lines originating from tumors in humans (WERI-Rb-1). The cytotoxic effect was evaluated by WST-assay (Roche Applied Science). The antimicrobial effect of the compound against Gram-negative, Gram-positive bacteria and the yeast Candida albicans was investigated.

Almost all transcribed human genes undergo alternative RNA splicing, which increases the diversity of the coding and non-coding cellular landscape. The resultant gene products might have distinctly different and, in some cases, even opposite functions. Therefore, the abnormal regulation of alternative splicing plays a crucial role in malignant transformation, development, and progression, a fact supported by the distinct splicing profiles identified in both healthy and tumor cells. Drug resistance, resulting in treatment failure, still remains a major challenge for current cancer therapy. Furthermore, tumor cells often take advantage of aberrant RNA splicing to overcome the toxicity of the administered chemotherapeutic agents. Thus, deciphering the alternative RNA splicing variants in tumor cells would provide opportunities for designing novel therapeutics combating cancer more efficiently. In the present review, we provide a comprehensive outline of the recent findings in alternative splicing in the most common neoplasms, including lung, breast, prostate, head and neck, glioma, colon, and blood malignancies. Molecular mechanisms developed by cancer cells to promote oncogenesis as well as to evade anticancer drug treatment and the subsequent chemotherapy failure are also discussed. Taken together, these findings offer novel opportunities for future studies and the development of targeted therapy for cancer-specific splicing variants.