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Showing 3 results for Lectin
L-Fucose as a terminal sugar in cellular glycoconjugates of colonic carcinoma
Arab Mr, Arab F, Karimi M, Shahraki Mr, Sargazei Gh,
Volume 66, Issue 7 (10-2008)
Abstract

Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 !mso]> ject classid="clsid:38481807-CA0E-42D2-BF39-B33AF135CC4D" id=ieooui> Background: Glycoconjugates are a class of cell surface glycoproteins, the terminal sugars of which are important indicators of neoplasia and the aberrant biological behavior of cancer cells. Lectins are a class of plant or animal glycoproteins that specifically bind to the terminal sugars of glycoconjugates. The aim of the present study is to identify the presence of L-fucose in cell surface glycoconjugates and extracellular matrix glycoconjugates of cancer cells of different grades of colonic adenocarcinoma.
Methods: Paraffin blocks of colonic adenocarcinoma tissue from 30 patients were collected from the Pathology Department of Khatam Al Anbia Hospital in Zahedan, Iran. Sections, 5-7μm thick, were prepared and stained using hematoxylin and eosin. Sections were graded histopathologically and then stained using the lectin Ulex europaeus agglutinin (UEA, 10μm/mL), which binds specifically to L-fucose, and Alcian blue (pH=2.5). Sections were graded blindly according to lectin staining intensity on a scale of 0-3. Collected data were analyzed using Kruskall-Wallis and Mann Whitney nonparametric tests with SPSS.
Results: Our results show that there is a significant difference in the staining intensity for L-fucose between tumoral cells of different grades of colon carcinoma (p<0.001). Results show that the degree of UEA lectin binding to cancer cells is lower in the cytoplasm and nucleus and higher in the extracellular matrix in tumors, with the degree increasing with histopathological grade. Furthermore, staining intensity differs in different portions of cancer cells.
Conclusions: The increased staining intensity of L-fucose in the extracellular matrix of colon carcinoma is a reflection of the aberrant protein glycosylation pathway in neoplasia.


Reactive oxygen species generation as marker of platelet activation in PRP derived platelet concentrates during storage: brief report
Amin Shahbaz Ghasabeh , Mehran Ghasemzadeh , Ehteramolsadat Hosseini ,
Volume 74, Issue 9 (12-2016)
Abstract

Background: Platelet storage is complicated by deleterious changes that cause progressive structural and functional damages, so-called platelet storage lesion (PSL). PSL is commonly manifested by augmented platelet activation which is also associated with the increased levels of reactive oxygen species (ROS). Whether ROS generation increases during the storage of platelet concentrates and whether it will be correlated with P-selectin expression as a valid marker of platelet activation was investigated in this study.

Methods: In our experimental study, six PRP-platelet concentrates were randomly obtained from Iranian Blood Transfusion Organization (IBTO). All the platelet products met the standard quality assessment based on AABB guidelines. Washed platelets were subjected to flow cytometry analysis for the evaluation of P-selectin expression and intracellular ROS production using DHR 123 in day 0, 1, 3 and 5 after storage. Statistical data were analyzed by Kruskal-Wallis test with Dunn’s multiple comparison test. For correlations, linear regression analysis was applied. P values of less than 0.05 were considered to be significant.

Results: Platelets ROS generation significantly increased from day 0 to day 5 of storage (P= 0.0002). This observed gradual increase was also directly correlated with the increasing levels of P-selectin expression during platelet storage (r= 0.72, P= 0.0001).

Conclusion: Our study showed significant increases in ROS generation during the storage of platelet concentrates correlated with the increments of P-selectin expression as an important marker of platelet activation. This finding suggests that the analysis of ROS generation can also be considered a marker of platelet activation during storage. However, whether ROS generation first induces platelet activation or platelet activation during storage triggers ROS generation is still remain to be determined.

Review of NKG2D function and its related ligands: review article
Davoud Farajzadeh , Parisa Jalali ,
Volume 76, Issue 5 (8-2018)
Abstract
The natural killer group 2D (NKG2D) is a transmembrane protein and a member of the CD94/NKG2 family of C-type lectin-like receptors. NKG2D is encoded by the KLRK1 gene, which is located in the NK-gene complex (NKC) placed on chromosomes 6 and 12 in mice and humans, respectively. NKG2D forms a homodimer structure and binds through ectodomains with its related ligands. Each of its monomers consists of two β-sheets, two α-helices, and four disulfide bands and also contains a β-strand that distinguishes it from other C-type lectin-like receptors. NKG2D ligands are homologs of major histocompatibility complex (MHC) class I molecules in mice and humans. MHC class I chain-related protein A (MICA) and B (MICB) and human cytomegalovirus UL16-binding proteins (ULBP1-6) are recognized by the human NKG2D. In Natural Killer (NK) cells, NKG2D-mediated cytotoxicity can be elicited via two different systems by signaling from immunoreceptor tyrosine-based activation motifs in DAP12 or via a Syk-independent pathway activated by DAP10. Therefore, NKG2D is an activating immunoreceptor which was first recognized on NK cells but subsequently found on γδT cells, CD8+ αβT cells, and macrophages. NKG2D-ligand diversity may facilitate the detection of the presence of a broad range of viruses and may provide protection against rapidly evolving cancers. NKG2D ligand recognition induces and/or improves immune responses to cancer cells. NK cells recognize a wide range of stressed cells. The activation of NKG2D receptor can lead to the lysis of the target cell and the production of various cytokines and chemokines depending on the nature of the stimulation as a result of NK and myeloid-mediated innate immunity and as well as T γδ and CD8+ mediated-adaptive immune system. However, inappropriate expression of NKG2D ligands could cause autoimmune diseases in healthy cells, including rheumatoid arthritis, colitis, celiac disease, multiple sclerosis, alopecia areata, type 1 diabetes, and chronic obstructive pulmonary disease. Therefore, a precise understanding of the structure and function of NKG2D receptor and its interaction with various ligands may lead to the development of strategies to treat autoimmune diseases. Hence, the purpose of this review is to examine the detailed studies on the function of NKG2D receptor and their related ligands.

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