To study the biological function of the N-glycosylation modification of prion proteins (PrP), various eukaryotic expression vectors for the mutants with N-glycosylation modification of human PrP had been constructed and expressed. With site-direct mutation technique, human PRNP gene was mutated and the obtained mutants were subcloned into eukaryotic expressing plasmid pcDNA3.1 and transiently expressed in Hela cervical adenocarcinoma cell. The expression products of the mutated PrP were identified with Western blotting assay and the PNGase digestion assay. Several mutants with specific glycosylation modification were identified from the expressed products by Western blot, including two mutants with one glycosylation site mutated and one without any mutation at glycosylation sites. The expressed products were digested with PNGase F. The wild type proteins and those with one of glycosylation sites mutated were digested, resulting in their molecular weights reduced, while the molecular weights of products with mutations at both glycosylation sites were not changed. The mutant of wild type human PRNP gene at N-glycosylation modification sites and six modified mutants with mono- or non-N-glycosylation had been obtained successfully in the study. Moreover, the modified PrP with mono- and non-N-glycosylation were able to be expressed transitantly in Hela cells, which could be a useful means for studying prions.
Escherichia coli ; genetics ; metabolism ; Glycation End Products, Advanced ; biosynthesis ; genetics ; Glycosylation ; HeLa Cells ; Humans ; Mutagenesis, Site-Directed ; Mutant Proteins ; biosynthesis ; genetics ; Prions ; biosynthesis ; genetics ; Transfection

The present study was designed to evaluate the therapeutic potential of bioactive compounds from chloroform extract of the leaves of Hylocereus undatus in the formation of advanced glycation end products (AGEs) in vitro. Bioactivity-guided fractionation of chloroform extract from Hylocereus undatus afforded two novel 12-ursen-type triterpenes, 3β, 16α, 23-trihydroxy-urs-12- en-28-oic acid (1) and 3β, 6β, 19α, 22α-tetrahydroxy-urs-12-en-28-oic acid (2), as well as four known triterpenes 2α, 3β, 23-tetrahydroxy-urs-11-en-28-oic acid (3), 3β-acetoxy-28-hydroxyolean-12-ene (4), 3β, 16α-dihidroxyolean-12-ene (5) and 3β-acetoxy-olean-12-ene (6). Our results revealed that triterpenes 1-3 were able to inhibit the formation of AGEs in all tested assays. The data indicated that the triterpenes had inhibitory activity at the múltiple stages of glycation and that there might be a high potential for decreasing protein oxidation and protein glycation that can enhance glycative stress in diabetic complications.
Cactaceae ; chemistry ; Glycation End Products, Advanced ; chemistry ; Glycosylation ; drug effects ; Molecular Structure ; Plant Extracts ; chemistry ; isolation & purification ; pharmacology ; Plant Leaves ; chemistry ; Triterpenes ; chemistry ; isolation & purification ; pharmacology

Humans ; Lung Neoplasms ; metabolism ; Receptor for Advanced Glycation End Products ; metabolism

This study was aimed to investigate the effect of advanced glycosylation end products (AGE) on the proliferation of K562 and K562/A02 cells, the effect of tetrandrine (Tet) on proliferation of K562 and K562/A02 cells induced by AGE, and their mechanisms. The effects of AGE on proliferation of K562 and K562/A02 cells and Tet on the proliferation of AGE-induced K562 and K562/A02 cells were assayed by CCK8 kit, the apoptosis rate and the expression of receptor of advanced glycosylation end products (RAGE) in K562 and K562/A02 cells were determined by flow cytometry, the expression of RAGE mRNA was detected by semi-quantitative RT-PCR. The results showed that AGE could promote the proliferation of K562 and K562/A02 cells in a concentration-dependent manner, the cell proliferation was enhanced with time increasing in 0 - 48 h, and was higher than control group after 72 h. AGE up-regulated the RAGE mRNA and protein expressions of K562 and K562/A02 cells in a concentration-dependent manner. Treatment of Tet combined with AGE for 48 h could inhibit the proliferation of K562 and K562/A02 cells promoted by AGE in a concentration-dependent manner, which probably by inducing cell apoptosis, however, there was no obvious effect in the up-regulating expression of RAGE mRNA and protein induced by AGE. It is concluded that AGE can promote the proliferation of K562 and K562/A02 cells, which is probably induced by up-regulating the expression of RAGE mRNA and protein. Tet can inhibit the proliferation of K562 and K562/A02 cells induced by AGE, and the mechanism may be not closely associated with changes of the up-regulating expression of RAGE mRNA and protein induced by AGE.
Apoptosis ; drug effects ; Benzylisoquinolines ; pharmacology ; Cell Proliferation ; drug effects ; Gene Expression Regulation, Leukemic ; Glycation End Products, Advanced ; pharmacology ; Humans ; K562 Cells ; Receptor for Advanced Glycation End Products ; metabolism

OBJECTIVEThis study aims to detect microRNA-17(mir-17) expression on the osteogenic differentiation of advanced glycation end products (AGEs)-stimulated hunman periodontal ligament stem cells (HPDLSCs) and to analyze the influence of these cells on this process.

METHODSHPDLSCs were isolated using limited dilution technique. After osteogenic differentiation occurred, different time points of mir-17 expression in the experimental groups were detected by real time polymerase chain reaction (PCR). The mir-17 overexpression and inhibition were evaluated using cell transfection technique. Differences in gene expressions were detected by real time PCR; differences in protein expressions were analyzed by Western blot.

RESULTSThe mir-17 expression was reduced after osteogenic differentiation occurred at 3, 7, and 14 d compared with that in the control group (P < 0.05). The expression levels of bone sialoprotein (BSP), Runt-related transcription factor-2 (Runx-2)and alkaline phosphatase (ALP) in the experimental groups were lower than those in the mimic control group when mir-17 expression increased. In addition, the protein expression levels of Runx-2 in the experimental groups were lower than those in the control group. The expression levels of BSP, Runx-2 and ALP in the experimental groups were higher than those in the inhibitor control group when mir-17 expression decreased. Likewise, the protein expression levels of Runx-2 in the experimental groups were higher than those in the control group.

CONCLUSIONAGEs inhibit the osteogenic differentiation of HPDLSCs by affecting mir-17 expression.

Atherosclerosis ; pathology ; C-Reactive Protein ; metabolism ; Dendritic Cells ; metabolism ; Glycation End Products, Advanced ; metabolism ; Humans ; Inflammation

OBJECTIVE: To investigate the correlation between soluble receptor for advanced glycation end products (sRAGE) level in the follicular fluid and ovarian responsiveness in non-PCOS patients undergoing controlled ovarian hyperstimulation. METHODS: Ninety non-PCOS patients underwent IVF/ICSI using a short-acting long protocol for ovarian stimulation with a GnRH agonist. For each patient, the level of sRAGE in the follicular fluid was measured by enzyme linked immunosorbent assay (ELISA), and the data including the clinical baseline state, hormone level, number of oocytes obtained and the fertilization rate were collected. RESULTS: Follicular fluid sRAGE level showed significant negative correlations with basal FSH level (=0.0036) and Gn dose ( < 0.0001) and positive correlations with AFC ( < 0.0001), number of oocytes obtained ( < 0.0001), and the fertilization rate (=0.0047). Follicular fluid sRAGE level was positively correlated with the number of oocytes obtained, and was significantly higher in cases with oocytes obtained above the target number (> 15) than in cases with oocytes obtained within the range of the target numbers (7-15) and below the target number (< 7) ( < 0.0001 and =0.0012, respectively). CONCLUSIONS Follicular fluid sRAGE level can reflect ovarian reserve function in non-PCOS patients, the number of oocytes obtained and the fertilization rate, and can thus predict ovarian responsiveness during controlled hyperstimulation in nonPCOS patients.
Female ; Fertilization in Vitro ; Follicular Fluid ; Humans ; Ovarian Hyperstimulation Syndrome ; Receptor for Advanced Glycation End Products

The number of patients with diabetic foot ulcer (DFU) has increased progressively year by year. Refractory DFU has brought great burden to the country and individuals. How to accelerate the healing of DFU has become the main emphasis of research. However currently, the mechanism of its refractory healing is not fully elucidated, and the correlation between the various mechanisms are not high. Therefore, its clinical standardization, and precise clinical diagnosis and treatment still face several challenges. Based on the progress of clinical research and basic research at home and abroad, this paper reviewed the specific mechanisms that lead to refractory DFU, with the focus on chronic inflammation, bacteria biofilm formation, high oxidative stress, growth factor inhibition, impaired microcirculation, and accumulation of advanced glycation end products.
Humans ; Diabetic Foot/metabolism* ; Wound Healing ; Glycation End Products, Advanced/metabolism* ; Diabetes Mellitus

This review reflects upon our own as well as other investigators' studies on the role of receptor for advanced glycation end-products (RAGE), bringing up the latest information on RAGE in physiology and pathology of the nervous system. Over the last ten years, major progress has been made in uncovering many of RAGE-ligand interactions and signaling pathways in nervous tissue; however, the translation of these discoveries into clinical practice has not come to fruition yet. This is likely, in part to be the result of our incomplete understanding of this crucial signaling pathway. Clinical trials examining the therapeutic efficacy of blocking RAGE-external ligand interactions by genetically engineered soluble RAGE or an endogenous RAGE antagonist, has not stood up to its promise; however, other trials with different blocking agents are being considered with hope for therapeutic success in diseases of the nervous system.
Humans ; Ligands ; Nervous System Diseases ; Receptor for Advanced Glycation End Products/metabolism* ; Signal Transduction/physiology*

No abstract available.
Glycosylation End Products, Advanced