Glucan-like synthetic oligosaccharides: iterative synthesis of linear oligo-beta-(1,3)-glucans and immunostimulatory effects

Small reducing and linear oligo-beta-(1,3)-glucans, which are able to act as phytoallexin elicitors or as immunostimulating agents in anticancer therapy, were synthesized according to an iterative strategy that involved a unique key monosaccharidic donor. To avoid anomeric mixtures, the reducing entity of the target oligomers was first locked with benzyl alcohol and further selective deprotection of the 3-OH with DDQ afforded the desired building block as an acceptor. The latter was then used in a second cycle of glycosylation/deprotection to afford the desired disaccharide, and successive reiterations of this process provided the desired oligomers. Unusual conformational behaviors were observed by standard NMR sequences and supported by NOESY studies. Finally, removal of protecting groups afforded free tri-, tetra-, and pentaglucosides in good overall yields. Two oligosaccharides representing linear laminaritetraose and laminaripentaose were compared to the recently described beta-(1,3)-glucan phycarine. Following an intraperitoneal injection, the influx of monocytes and granulocytes into the blood and macrophages into the peritoneal cavity was comparable to that caused by phycarine. Similarly, both oligosaccharides stimulated phagocytic activity of granulocytes and macrophages. Using ELISA, we also demonstrated a significant stimulation of secretion of IL-1beta. Together these results suggest that the synthetic oligosaccharides have similar stimulatory effects as natural beta-(1,3)-glucans.     

Characterization of Arabidopsis thaliana mutant ror-1 (roscovitine-resistant) and its utilization in understanding of the role of cytokinin N-glucosylation pathway in plants

Cytokinin analogue roscovitine exhibits a strong inhibitory effect on cytokinin N-glucosylation, one of the most important pathways of cytokinin inactivation in plants. Roscovitine-resistant mutant. (ror-1) was isolated using T-DNA tagged lines of Arabidopsis thaliana (L.) Heynh in order to find a gene putatively involved in cytokinin N-glucosylation. The amount of cytokinin N-glucosides of trans-zeatin- and isopentenyladenine-type was elevated by 20% in ror-1 mutant compared to WT. The cytokinin oxidase/dehydrogenase activity exhibited a mild elevation in ror-1 compared to WT in basal media. Additionally, ror-1 plants showed slightly enhanced resistance to exogenously supplied aromatic cytokinins (benzyladenine). Incubation with exogenous cytokinin (5 μM BA for 24 h) resulted in significant up-regulation of ROR-1 gene expression in ror-1 mutant. In silico analysis showed that ROR-1 gene encoded for a protein consisting of GRAM (Glycosyltransferases Rab-like GTPase activators and Myotubularins) and C2 domains. Here, we report on the role of ROR-1 gene in metabolism of bioactive cytokinins in the plants.     

Changes of collagen metabolism predict the left ventricular remodeling after myocardial infarction

Objectives: To analyze the predictive value of cardiac collagen metabolism “in vivo" in patients with myocardial infarction (MI) treated with percutaneous coronary intervention (PCI). Design: Forty-five patients (age 66 ± 8.27) underwent biochemical analysis for cardiac collagen metabolism (groups A, B and C); 30 patients with their first MI were treated with successful PCI (group A; n = 30), group B (n = 5) were MI patients with unsuccessful PCI. Group C were patients without MI (n = 10), they underwent elective diagnostic coronary angiography only. The collagen metabolism was analyzed in acute and subacute MI phases by using serum blood markers: the carboxy-terminal propeptide of type I procollagen (PICP), amino-terminal propeptide of type III procollagen (PIIINP) and carboxy-terminal telopeptide of type I collagen (ICTP). Furthermore, the ejection fraction (EF) and left ventricular end-diastolic volume maximal changes in the course of 6 months were measured by echocardiography. Results: A significant increase of both PICP and PIIINP on day 4 following MI was detected. Furthermore, PICP and PIIINP level assessed on the 30th day was significantly higher in the PCI unsuccessful group versus successful group. PICP level on day 4 above 110 ug/l and PIIINP level above 4 ug/l was significantly often found in the subgroup of patients with the EF improvement less than 10% or worsening and with significant left ventricular dilatation during 6 months follow-up. Cardiac catheterization itself does not affect collagen metabolism. Conclusion: We concluded that collagen metabolism markers enable to study in vivo the MI healing and to predict left ventricular functional and volume changes.     

Orthogonal factor coefficient development of subcutaneous adipose tissue topography (SAT-Top) in girls and boys

The new optical device Lipometer allows noninvasive, quick, and safe determination of the thickness of subcutaneous adipose tissue (SAT) layers (in mm) at any site of the human body. The specification of 15 evenly distributed body sites enables the precise measurement of subcutaneous body fat distribution, so-called subcutaneous adipose tissue topography (SAT-Top). SAT-Top was measured in 980 children aged 7-19 years. In this paper we describe the degree to which SAT-Top body sites are intercorrelated. We consider whether a meaningful reduction of data is possible using factor analysis, which factors can be extracted, and how SAT-Top data of children can be added to a factor value plot, depicting the essential results of age-dependent subcutaneous fat development. SAT layers situated on the same body area provide correlation coefficients up to +r = 0.91. Two factors are extracted: factor 1, containing all upper body sites (from neck to hip); and factor 2, consisting of all leg body sites. When all 980 children are divided into three age groups in a factor value plot, the first age group (7-11 years) shows almost equal SAT-Top development in boys and girls. Afterwards, for the consecutive age groups 2 (11-15 years) and 3 (15-19 years), the age-dependent subcutaneous fat development of boys and girls progresses into nearly orthogonal directions.     

Glucan and resveratrol complex--possible synergistic effects on immune system

BACKGROUND: Recent data showing that glucan elicited defense responses in grapevine and induced protection via induction of resveratrol production led us to evaluate the possible synergetic effects of glucan and resveratrol complex on immune reactions. METHODS: We measured phagocytosis using HEMA particles, expression of cell surface markers via fl ow cytometry, expression of cytokines using ELISA, recovery after fluorouracil-induced leucopenia and effects on gene expression via RT-PCR. RESULTS: Our results showed that both glucan and resveratrol complex stimulated phagocytosis of blood leukocytes, caused increase in surface expression of CD(+) splenocytes and showed higher restoration of spleen recovery after experimentally induced leucopenia. In all these cases, strong synergetic effects were observed. When we measured the effects of these substances on expression level of NF-kappaB2, Cdc42 and Bcl-2 in breast cancer cells, upregulation of Cdc42 expression was evident only using both immunomodulators in combination. CONCLUSIONS: In conclusion, our data suggest significant synergy in stimulation of immune reactions and support further studies of these natural immunomodulators.