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

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*

OBJECTIVETo investigate the accumulation of advanced glycation end products (AGEs) and expression of receptor for AGEs (RAGE) in streptozocin (STZ)-induced diabetic nephropathy in rats, and the role of antioxidants on the AGEs-RAGE signaling.

METHODSDiabetic rats were induced by once intraperitoneal injection of STZ at the dose of 60 mg/kg, and randomly divided into the DN group (n=12, treated with normal saline by intraperitoneal injection, once daily), the extract of Ginkgo biloba (EGb) group (n=14, treated with EGb 300 mg/kg by oral administration, once every other day), and the alpha-lipoic acid (ALA) group (n=12, treated with ALA at the dose of 35 mg/kg by intraperitoneal injection, once every other day). Rats of the normal control group (n=10) were given vehicle citrate buffer at the dose of 60 mg/kg. Rats were sacrificed at the 12th week and the 20th week of this study. The four groups were compared in terms of body weight, blood glucose, renal function, 24-h urine protein. Renal pathological changes were observed by PAS staining. Oxidative stress indices were detected using spectrophotometry. The concentrations of AGEs were measured using fluoro spectrophotometry, and the expressions of RAGE were detected by Real-time PCR and Western blot.

RESULTSCompared with the normal control group, the 24-h urine protein quantitation was higher and the glomerular filtration rate increased in rats at the 12th week and the 20th week. The pathological tissue staining showed dilated glomerular mesangium, proliferated glomerular matrix, vacuolar degeneration of the renal tubular epithelium. Malonaldehyde (MDA) levels and 8-hydroxide radical guanine deoxyriboside (8-OHdG) levels increased, and catalase (CAT) and reduced glutathione hormone (GSH) levels decreased. The AGEs contents in serum and renal tissue homogenate increased. The expressions of RAGE mRNA and protein increased in the DN group at the 12th and the 20th week. The 24-h urine protein quantitation was reduced in the EGb group and the ALA group, with alleviated pathological changes, lowered MDA and 8-OHdG levels, increased CAT and GSH levels, decreased AGEs contents, and down-regulated RAGE expressions.

CONCLUSIONSAGEs contents increased and RAGE expression up-regulated in the circulation and local renal tissues in DN rats. EGb and ALA could inhibit AGEs production and down-regulate RAGE expressions by reducing oxidative stress, thus further improving the renal tissue structure and renal functions of DN rats. It had better application prospect in treatment and prevention of DN.

Animals ; Antioxidants ; pharmacology ; Diabetes Mellitus, Experimental ; metabolism ; Diabetic Nephropathies ; metabolism ; Ginkgo biloba ; Glycation End Products, Advanced ; metabolism ; Kidney ; metabolism ; Male ; Rats ; Rats, Wistar ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; metabolism ; Thioctic Acid ; pharmacology

OBJECTIVETo investigate the effects of advanced glycosylation end products (AGEs) modified bovine serum albumin (AGE-BSA) on the expression of reactive oxygen species (ROS) and monocyte chemoattractant protein-1 (MCP-1) in human renal mesangial cells (HRMCs).

METHODSHRMCs were cultured in vitro with medium containing different doses of AGE-BSA or BSA (50,100, 200, 400 mg/L) for 48 hours, or with AGE-BSA (200 mg/L) for different times (12, 24, 48, 72 h). Immunocytochemistry assay was used to estimate the protein level of RAGE. The ROS in cells were measured by flow cytometry and the mRNA expression of MCP-1 were analyzed by semi-quantiative reverse transcription-polymerase chain reaction (RT-PCR) after treatment with AGE-BSA or BSA.

RESULTSThe protein level of RAGE was upregulated in the HRMCs with AGE-BSA. The expression of ROS and MCP-1 significantly enhanced by incubation of AGE-BSA in a time- and dose-dependent manner. The effects of AGE-BSA-induced up-regulation of ROS and MCP-1 level was significantly blocked by neutralizing antibodies to RAGE, while the expression of ROS and MCP-1 stood nearly unchanged after cultured with huamn IgG.

CONCLUSIONThe expression of ROS and MCP-1 in HRMCs is induced by AGE-BSA through RAGE, which may have potential effects in the pathgenic mechanism of diabetic nephropathy.

Cells, Cultured ; Chemokine CCL2 ; metabolism ; Glycation End Products, Advanced ; pharmacology ; Humans ; Mesangial Cells ; drug effects ; metabolism ; Oxidative Stress ; drug effects ; Reactive Oxygen Species ; metabolism ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; metabolism ; Serum Albumin, Bovine ; pharmacology

OBJECTIVETo study the expression of the receptor for advanced glycation end products (RAGE) and the inhibitory effect of advanced glycation end products (AGEs) on testosterone production in rat Leydig cells.

METHODSRat Leydig cells were primarily cultured and the expression of RAGE in the Leydig cells was detected by RT-PCR and immunofluorescence staining. The Leydig cells were treated with AGEs at the concentrations of 25, 50, 100 and 200 microg/ml, respectively, and the testosterone content was determined by ELISA.

RESULTSRT-PCR and immunofluorescence staining exhibited the expression of RAGE in the rat Leydig cells. AGEs remarkably suppressed hCG-induced testosterone production in the Leydig cells in a concentration-dependent manner in the 50, 100 and 200 microg/ml groups as compared with the control (P < 0.01).

CONCLUSIONRAGE exists in rat Leydig cells and AGEs can significantly inhibit the secretion of testosterone in primarily cultured rat Leydig cells.

Animals ; Cells, Cultured ; Enzyme-Linked Immunosorbent Assay ; Glycation End Products, Advanced ; pharmacology ; Leydig Cells ; metabolism ; radiation effects ; Male ; Rats ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction ; Testosterone ; biosynthesis

OBJECTIVETo investigate lipopolysaccharide (LPS)-induced changes of cytoskeletal filamentous actin in primary isolated pulmonary microvascular endothelial cells (PMVECs) from wild-type and RAGE knock-out mouse.

METHODSThe lungs of wild-type and RAGE knock-out mice were digested with collagenase type I to obtain endothelial cells purified by anti-CD31-coupled magnetic beads. The PMVEC identified by factor VIII labeling were stimulated with LPS at different concentrations and the changes of filamentous actin were observed by confocal microscopy.

RESULTSThe cultured primary cells showed typical endothelial cell phenotype as examined with factor VIII labeling. LPS stimulation caused rearrangement of the cytoskeletal filament F-actin in wild-type mouse PMVECs with stress fiber formation, but such changes were not obvious in RAGE knock-out mouse PMVECs.

CONCLUSIONMouse PMVECs of a high purity can be obtained by immune magnetic beads. RAGE is involved in LPS-induced destruction of mouse PMVEC cytoskeletons.

Actins ; metabolism ; Animals ; Cells, Cultured ; Cytoskeleton ; metabolism ; Endothelial Cells ; cytology ; Lipopolysaccharides ; Lung ; cytology ; Mice ; Mice, Knockout ; Microvessels ; cytology ; Phenotype ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; genetics ; metabolism

To investigate the potential molecular markers and drug-compound-target mechanism of Mahuang Shengma Decoction(MHSM) in the intervention of acute lung injury(ALI) by network pharmacology and experimental verification. Databases such as TCMSP, TCMIO, and STITCH were used to predict the possible targets of MHSM components and OMIM and Gene Cards were employed to obtain ALI targets. The common differentially expressed genes(DEGs) were therefore obtained. The network diagram of DEGs of MHSM intervention in ALI was constructed by Cytoscape 3. 8. 0, followed by Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses of target genes. The ALI model was induced by abdominal injection of lipopolysaccharide(LPS) in mice. Bronchoalveolar lavage fluid(BALF) was collected for the detection of inflammatory factors. Pathological sectioning and RT-PCR experiments were performed to verify the therapeutic efficacy of MHSM on ALI. A total of 494 common targets of MHSM and ALI were obtained. Among the top 20 key active compounds of MHSM, 14 from Ephedrae Herba were found to be reacted with pivotal genes of ALI [such as tumor necrosis factor(TNF), tumor protein 53(TP53), interleukin 6(IL6), Toll-like receptor 4(TLR4), and nuclear factor-κB(NF-κB)/p65(RELA)], causing an uncontrolled inflammatory response with activated cascade amplification. Pathway analysis revealed that the mechanism of MHSM in the treatment of ALI mainly involved AGE-RAGE, cancer pathways, PI3 K-AKT signaling pathway, and NF-κB signaling pathway. The findings demonstrated that MHSM could dwindle the content of s RAGE, IL-6, and TNF-α in the BALF of ALI mice, relieve the infiltration of inflammatory cells in the lungs, inhibit alveolar wall thickening, reduce the acute inflammation-induced pulmonary congestion and hemorrhage, and counteract transcriptional activities of Ager-RAGE and NF-κB p65. MHSM could also synergically act on the target DEGs of ALI and alleviate pulmonary pathological injury and inflammatory response, which might be achieved by inhibiting the expression of the key gene Ager-RAGE in RAGE/NF-κB signaling pathway and downstream signal NF-κB p65.
Acute Lung Injury/genetics* ; Animals ; Drugs, Chinese Herbal/pharmacology* ; Lipopolysaccharides ; Lung/metabolism* ; Mice ; NF-kappa B/metabolism* ; Network Pharmacology ; Receptor for Advanced Glycation End Products/metabolism* ; Signal Transduction

OBJECTIVETo investigate the influence of high mobility group box-1 protein (HMGB1) on apoptosis of peritoneal macrophages in mice and its receptor mechanism.

METHODSThe peritoneal macrophages were isolated from female BALB/c mice and divided into 4 groups according to different stimuli: i. e, HMGB1 group (with treatment of 10 microg/ml HMGB1 for 24 hours), HMGB1 and anti-receptor advanced glycation end products (RAGE) antibody group (with treatment of 5 microg/ml anti-RAGE antibody for 2 hours followed by HMGB1 stimulation), Recombinant mouse RAGE/Fc chimera (rmRAGE/Fc) and HMGB1 group (10 microg/ml of rmRAGE/Fc and 10 microg/ml HMGB1 were pre-mixed for 2 hours, then the peritoneal macrophages were treated with the mixture), control group (with treatment of phosphate buffer). Expression of RAGE on the surface of macrophages, and the apoptotic rate of the cells were determined by flow cytometry. Laser scanning confocal microscopy was used to observe the apoptosis of the cells.

RESULTSThe percentage of macrophages with positive RAGE expression in HMGB1 group [(54 +/- 12%)] was markedly increased compared to the controls [(13 +/- 5)%, P < 0.01], and fluorescence density of RAGE expression was also significantly different between two groups (126 +/- 10 vs 34 +/- 8, P < 0.01). The occurrence of apoptosis in HMGB1 and rmRAGE/Fc group, as well as in HMGB1 plus anti-RAGE group were much higher than that in control group, and the number of macrophages with apoptosis and necrosis at late stage was obviously increased in HMGB1 group. The apoptic rate in HMGB1 group was (39.5 +/- 2.3)%, which was significantly higher than those in HMGB1 and rmRAGE/Fc group (17.3 +/- 3.6)%, and HMGB1 and anti RAGE group (14.8 +/- 4.8)%, (P < 0.01), which were significantly higher than those in control groups (5.4 +/- 2.3)%, (P < 0.01).

CONCLUSIONRAGE is one of the major receptor to induce apoptosis of macrophages, and the up-regulation of its expression is induced by HMGB1.

Animals ; Apoptosis ; Female ; Gene Expression Regulation ; HMGB1 Protein ; pharmacology ; Macrophages, Peritoneal ; cytology ; metabolism ; Mice ; Mice, Inbred BALB C ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; metabolism

OBJECTIVETo construct eukaryotic expression vectors for HA-tagged receptor for advanced glycation end products (RAGE) mutants.

METHODSSite-directed mutagenesis was applied to wild-type RAGE gene cloned in the pcDNA3 vector with HA tag to obtain the mutants pcDNA3-HA-RAGE(S391A), pcDNA3-HA-RAGE(S399A), pcDNA3-HA-RAGE(S400A), and pcDNA3-HA-RAGE(T401A). After identification by sequencing, the mutants were transfected into HEK293 cells, and the expression of these mutants were detected by Western blotting using anti-HA antibody.

RESULTSThe HA-tagged RAGE mutants constructed were verified successfully by sequencing, and highly expressed in HEK293 cells.

CONCLUSIONThe success in constructing HA-tagged RAGE mutants, which are highly expressed in eukaryotic cells, may facilitate the functional study of RAGE in cell signal transduction.

Cell Line ; Cloning, Molecular ; Eukaryotic Cells ; metabolism ; Genetic Vectors ; genetics ; Humans ; Mutagenesis, Site-Directed ; Mutation ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; biosynthesis ; genetics