OBJECTIVE: To investigate the molecular mechanisms underlying the beneficial effect of electroacupuncture (EA) in experimental models of Alzheimer's disease (AD) in vivo. METHODS: Senescence-accelerated mouse prone 8 (SAMP8) mice were used as AD models and received EA at Yingxiang (LI 20, bilateral) and Yintang (GV 29) points for 20 days. For certain experiments, SAMP8 mice were injected intravenously with human fibrin (2 mg). The Morris water maze test was used to assess cognitive and memory abilities. The changes of tight junctions of blood-brain barrier (BBB) in mice were observed by transmission electron microscope. The expressions of fibrin, amyloid- β (Aβ), and ionized calcium-binding adapter molecule 1 (IBa-1) in mouse hippocampus (CA1/CA3) were detected by reverse transcription-quantitative polymerase chain reaction (qRT-PCR), Western blot or immunohistochemical staining. The expression of fibrin in mouse plasma was detected by enzyme-linked immunosorbent assay. The expressions of tight junction proteins zonula occludens-1 and claudin-5 in hippocampus were detected by qRT-PCR and immunofluorescence staining. Apoptosis of hippocampal neurons was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. RESULTS: Fibrin was time-dependently deposited in the hippocampus of SAMP8 mice and this was inhibited by EA treatment (P<0.05 or P<0.01). Furthermore, EA treatment suppressed the accumulation of Aβ in the hippocampus of SAMP8 mice (P<0.01), which was reversed by fibrin injection (P<0.05 or P<0.01). EA improved SAMP8 mice cognitive impairment and BBB permeability (P<0.05 or P<0.01). Moreover, EA decreased reactive oxygen species levels and neuroinflammation in the hippocampus of SAMP8 mice, which was reversed by fibrin injection (P<0.05 or P<0.01). Mechanistically, EA inhibited the promoting effect of fibrin on the high mobility group box protein 1 (HMGB1)/toll-like receptor 4 (TLR4) and receptor for advanced glycation end products (RAGE)/nicotinamide adenine dinucleotide phosphate (NADPH) signaling pathways (P<0.01). CONCLUSION EA may potentially improve cognitive impairment in AD via inhibition of fibrin/A β deposition and deactivation of the HMGB1/TLR4 and RAGE/NADPH signaling pathways.
Mice ; Humans ; Animals ; NADP/metabolism* ; Toll-Like Receptor 4 ; HMGB1 Protein/metabolism* ; Receptor for Advanced Glycation End Products/metabolism* ; Blood-Brain Barrier/metabolism* ; Neuroinflammatory Diseases ; Electroacupuncture ; Alzheimer Disease/therapy* ; Hippocampus/metabolism* ; Amyloid beta-Peptides/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*

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

Objective To investigate the effects of simvastatin on diabetic neuropathic pain and systematic inflammation in diabetic rats and explore their molecular mechanisms.Methods Totally 24 rats were equally randomized into the normal+vehicle(NV)group,diabetic+vehicle(DV)group,and diabetic+simvastatin(DS)group using the random number table.Streptozotocin(STZ)was used to establish the rat models of diabetes.Blood glucose,body mass,paw withdrawal mechanical threshold(PWMT),and paw withdrawal thermal latency(PWTL)in each group were observed on days 7,14,21,and 28 after STZ injection.On day 28 after STZ injection,rats were sacrificed,and the lumbar spinal dorsal horn and serum were collected.Western blotting was used to detect the expression of receptor for advanced glycation end products(RAGE)and the phosphorylation levels of protein kinase B(AKT),extracellular signal-regulated kinase(ERK),p38,and c-Jun N-terminal kinase(JNK)in the spinal dorsal horn of rats in each group.Enzyme-linked immunosorbent assay was performed to determine the serum concentrations of oxidized low density lipoprotein(ox-LDL)and interleukin-1β(IL-1β).Results On days 14,21 and 28 after STZ injection,the PWMT in DV group were(8.6 ± 0.8),(7.1 ± 1.6),and(7.8 ± 0.8)g respectively,which were significantly lower than (12.0 ± 0.9)(=8.482, =0.000),(11.6 ± 1.5)(=11.309, =0.000),and(11.7 ± 1.5)g(=9.801, =0.000)in NV group.The PWMT in DS group on days 21 and 28 were(9.4 ± 1.4)(=5.780, =0.000)and(9.7 ± 0.9)g(=4.775, =0.003),respectively,which were significantly improved comparing with those of DV group.On days 7,14,21,and 28,there were no significant differences in PWTL among these three groups (all <0.05).The expression of RAGE in the spinal dorsal horn of DV group was significantly higher than those of NV group(=6.299, =0.000)and DS group(=2.891, =0.025).The phosphorylation level of AKT in the spinal dorsal horn of DV group was significantly higher than those of NV group(=8.915,=0.000)and DS group(=4.103,=0.003).The phosphorylation levels of ERK( =8.313,=0.000),p38( =2.965, =0.022),and JNK(=7.459, =0.000)in the spinal dorsal horn of DV group were significantly higher than those of NV group;the phosphorylation level of JNK in the spinal dorsal horn of DS group was significant lower than that of DV group(=3.866, =0.004);however,there were no significant differences in the phosphorylation levels of ERK(=1.987,=0.122)and p38(=1.260,=0.375)in the spinal dorsal horn between DS group and DV group.The serum concentrations of ox-LDL and IL-1β in DV group were(41.86 ± 13.40)ng/ml and(108.16 ± 25.88)pg/ml,respectively,which were significantly higher than those in NV group [(24.66 ± 7.87)ng/ml(=3.606,=0.003)and(49.32 ± 28.35)pg/ml(=5.079,=0.000)] and DS group [(18.81 ± 5.62)ng/ml (=4.833, =0.000)and(32.73 ± 11.73)pg/ml(=6.510, =0.000)].Conclusions Simvastatin can relieve the mechanical allodynia of diabetic rats possibly by inhibiting the activation of RAGE/AKT and the phosphorylation of JNK in the spinal dorsal horn.Simvastatin can also decrease the serum concentrations of ox-LDL and IL-1β in diabetic rats,which may contribute to the relief of systematic inflammation.
Animals ; Diabetes Mellitus, Experimental ; complications ; Hyperalgesia ; Inflammation ; drug therapy ; Interleukin-1beta ; blood ; Lipoproteins, LDL ; blood ; Neuralgia ; drug therapy ; Proto-Oncogene Proteins c-akt ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptor for Advanced Glycation End Products ; metabolism ; Simvastatin ; pharmacology

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

The aim of this study was to investigate the effects of high-advanced glycation end products (AGEs) diet on diabetic vascular complications. The Streptozocin (STZ)-induced diabetic mice were fed with high-AGEs diet. Diabetic characteristics, indicators of renal and cardiovascular functions, and pathohistology of pancreas, heart and renal were evaluated. AGEs/RAGE/ROS pathway parameters were determined. During the experiments, the diabetic mice exhibited typical characteristics including weight loss, polydipsia, polyphagia, polyuria, high-blood glucose, and low-serum insulin levels. However, high-AGEs diet effectively aggravated these diabetic characteristics. It also increased the 24-h urine protein levels, serum levels of urea nitrogen, creatinine, c-reactive protein (CRP), low density lipoprotein (LDL), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in the diabetic mice. High-AGEs diet deteriorated the histology of pancreas, heart, and kidneys, and caused structural alterations of endothelial cells, mesangial cells and podocytes in renal cortex. Eventually, high-AGEs diet contributed to the high-AGE levels in serum and kidneys, high-levels of reactive oxygen species (ROS) and low-levels of superoxide dismutase (SOD) in serum, heart, and kidneys. It also upregulated RAGE mRNA and protein expression in heart and kidneys. Our results showed that high-AGEs diet deteriorated vascular complications in the diabetic mice. The activation of AGEs/RAGE/ROS pathway may be involved in the pathogenesis of vascular complications in diabetes.
Animals ; Diabetes Mellitus, Experimental ; complications ; metabolism ; Diabetic Angiopathies ; genetics ; metabolism ; Diet ; adverse effects ; Glycation End Products, Advanced ; metabolism ; Humans ; Interleukin-6 ; metabolism ; Kidney ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Oxidative Stress ; Pancreas ; metabolism ; Reactive Oxygen Species ; metabolism ; Receptor for Advanced Glycation End Products ; genetics ; metabolism ; Superoxide Dismutase ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

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

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

This study investigated the effect of advanced glycation end products (AGEs) on differentiation of naïve CD4(+) T cells and the role of the receptor of AGEs (RAGE) and peroxisome proliferator-activated receptors (PPARs) activity in the process in order to gain insight into the mechanism of immunological disorders in diabetes. AGEs were prepared by the reaction of bovine serum albumin (BSA) with glucose. Human naïve CD4(+) T cells, enriched from blood of healthy adult volunteers with negative selection assay, were cultured in vitro and treated with various agents including AGEs, BSA, high glucose, PGJ2 and PD68235 for indicated time. In short hairpin (sh) RNA knock-down experiment, naïve CD4(+) T cells were transduced with media containing shRNA-lentivirus generated from lentiviral packaging cell line, Lent-X(TM) 293 T cells. Surface and intracellular cytokine stainings were used for examination of CD4(+) T cell phenotypes, and real-time PCR and Western blotting for detection of transcription factor mRNA and protein expression, respectively. The suppressive function of regulatory T (Treg) cells was determined by a [(3)H]-thymidine incorporation assay. The results showed that AGEs induced higher pro-inflammatory Th1/Th17 cells differentiated from naïve CD4(+) T cells than the controls, whereas did not affect anti-inflammatory Treg cells. However, AGEs eliminated suppressive function of Treg cells. In addition, AGEs increased RAGE mRNA expression in naïve CD4(+) T cells, and RAGE knock-down by shRNA eliminated the effect of AGEs on the differentiation of CD4(+) T cells and the reduction of suppressive function of Treg cells. Furthermore, AGEs inhibited the mRNA expression of PPARγ, not PPARα PPARγ agonist, PGJ2, inhibited the effect of AGEs on naïve CD4(+) T cell differentiation and reversed the AGE-reduced suppressive function of Treg cells; on the other hand, PPARγ antagonist, PD68235, attenuated the blocking effect of RAGE shRNA on the role of AGEs. It was concluded that AGEs may promote CD4(+) T cells development toward pro-inflammatory state, which is associated with increased RAGE mRNA expression and reduced PPARγ activity.
Adult ; Animals ; Blotting, Western ; CD4-Positive T-Lymphocytes ; drug effects ; metabolism ; Cattle ; Cell Differentiation ; drug effects ; Cells, Cultured ; Glucose ; pharmacology ; Glycation End Products, Advanced ; pharmacology ; HEK293 Cells ; Humans ; Interferon-gamma ; metabolism ; Interleukin-17 ; metabolism ; PPAR gamma ; agonists ; genetics ; metabolism ; Prostaglandin D2 ; analogs & derivatives ; pharmacology ; RNA Interference ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Serum Albumin, Bovine ; pharmacology ; T-Lymphocytes, Regulatory ; drug effects ; metabolism ; Th1 Cells ; drug effects ; metabolism ; Th17 Cells ; drug effects ; metabolism

Accumulation of amyloid-beta peptides (Aβ) results in amyloid burden in normal aging brain. Clearance of this peptide from the brain occurs via active transport at the interfaces separating the central nervous system (CNS) from the peripheral circulation. The present study was to investigate the change of Aβ transporters expression at the choroid plexus (CP) in normal aging. Morphological modifications of CP were observed by transmission electron microscope. Real-time RT-PCR was used to measure mRNA expressions of Aβ(42) and its transporters, which include low density lipoprotein receptor-related protein-1 and 2 (LRP-1 and -2), P-glycoprotein (P-gp) and the receptor for advanced glycation end-products (RAGE), at the CP epithelium in rats at ages of 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33 and 36 months. At the same time, the mRNA expressions of oxidative stress-related proteins were also measured. The results showed that a striking deterioration of the CP epithelial cells and increased Aβ(42) mRNA expression were observed in aged rats, and there was a decrease in the transcription of the Aβ efflux transporters, LRP-1 and P-gp, no change in RAGE mRNA expression and an increase in LRP-2, the CP epithelium Aβ influx transporter. Heme oxygenase-1 (HO-1) and caspase-3 expressions at the CP epithelium increased with age at the mRNA level. These results suggest the efficacy of the CP in clearing of Aβ deceases in normal aging, which results in the increase of brain Aβ accumulation. And excess Aβ interferes with oxidative phosphorylation, leads to oxidative stress and morphological structural changes. This in turn induces further pathological cascades of toxicity, inflammation and neurodegeneration process.
ATP Binding Cassette Transporter, Sub-Family B ; metabolism ; Aging ; Amyloid beta-Peptides ; metabolism ; Animals ; Caspase 3 ; metabolism ; Choroid Plexus ; physiology ; Heme Oxygenase (Decyclizing) ; metabolism ; LDL-Receptor Related Proteins ; metabolism ; Oxidative Stress ; Peptide Fragments ; metabolism ; Rats ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; metabolism