• The Korean Journal of Physiology and Pharmacology
• /
• v.18 no.1
• /
• pp.1-14
• /
• 2014

During long standing hyperglycaemic state in diabetes mellitus, glucose forms covalent adducts with the plasma proteins through a non-enzymatic process known as glycation. Protein glycation and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic complications like retinopathy, nephropathy, neuropathy, cardiomyopathy along with some other diseases such as rheumatoid arthritis, osteoporosis and aging. Glycation of proteins interferes with their normal functions by disrupting molecular conformation, altering enzymatic activity, and interfering with receptor functioning. AGEs form intra- and extracellular cross linking not only with proteins, but with some other endogenous key molecules including lipids and nucleic acids to contribute in the development of diabetic complications. Recent studies suggest that AGEs interact with plasma membrane localized receptors for AGEs (RAGE) to alter intracellular signaling, gene expression, release of pro-inflammatory molecules and free radicals. The present review discusses the glycation of plasma proteins such as albumin, fibrinogen, globulins and collagen to form different types of AGEs. Furthermore, the role of AGEs in the pathogenesis of diabetic complications including retinopathy, cataract, neuropathy, nephropathy and cardiomyopathy is also discussed.

• Journal of Ginseng Research
• /
• v.39 no.2
• /
• pp.116-124
• /
• 2015

Background: Ginseng, the root of Panax ginseng (PG), is used widely as a herbal medicine to prevent and treat various diseases. Panax ginseng has pharmacological effects on neurodegenerative diseases such as Alzheimer's disease (AD). The present study evaluated the neuroprotective effects of PG and its possible neuroprotective mechanisms in advanced glycation end product (AGE)-induced AD in a rat model. Methods: Advanced glycation end products were injected bilaterally into the CA3 region of the rats' brains. The Morris water maze test and step-down type passive avoidance test were performed to evaluate their memory and cognitive abilities. The oxidation indexes in the hippocampus were detected. Immunohistochemistry was conducted to visualize the receptors for advanced glycation end products (RAGEs) and nuclear factor-kappa-light-chain-enhancer of activated B cell (NF-${\kappa}B$). Results: Behavioral results showed that PG (1 g/kg, 0.5 g/kg, and 0.25 g/kg) significantly shortened the escape latency, remarkably increased the number of crossing times, significantly decreased the number of errors, and prolonged the latency in rats with AGE-induced AD. Panax ginseng also significantly reduced the malondialdehyde level, increased the glutathione content, and increased superoxide dismutase activity in the hippocampus. Panax ginseng significantly decreased the expression of RAGE and NF-${\kappa}B$. The blockade of anti-RAGE antibody could significantly reduce AGE-induced impairments and regulate these expressions. Conclusion: Our results demonstrated that PG significantly inhibits AGE-induced memory impairment and attenuates Alzheimer-like pathophysiological changes. These neuroprotective effects of PG may be associated with the RAGE/NF-${\kappa}B$ pathway. Our results provided the experimental basis for applying PG in preventing and treating AD.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.47 no.6
• /
• pp.445-453
• /
• 2021

Objectives: Periodontitis is the most common chronic disease that causes tooth loss and is related to systemic diseases such as cardiovascular disease and diabetes. An objective indicator of the current activity of periodontitis is necessary. Soluble forms of the receptor for advanced glycation end products (sRAGE) are markers that reflect the status of inflammatory diseases. In this study, the relationship between sRAGE and periodontitis was analyzed to determine whether it can be used to diagnose the current state of periodontitis. Patients and Methods: Eighty-four patients without any systemic diseases were diagnosed with periodontitis using three classifications of periodontitis. Demographics and oral examination data such as plaque index (PI), bleeding on probing (BOP) index, and probing pocket depth (PPD) were analyzed according to each classification. In addition, correlation and partial correlation between sRAGE and the values indicating periodontitis were analyzed. Results: In each classification, the level of sRAGE tended to decrease if periodontitis was present or severe, but this change was not statistically significant. sRAGE and periodontitis-related variables exhibited a weak correlation, among which the BOP index showed a relatively strong negative correlation (ρ=-0.20). Based on this, on analyzing the correlation between the BOP index and sRAGE in the group with more severe periodontitis (PPD≥5 mm group, severe group of AAP/CDC [American Academy of Periodontology/Centers for Disease Control and Prevention], periodontitis group of López), the correlation further increased (ρ=-0.23, -0.40, -0.50). Partial correlation analysis of the sRAGE and BOP index showed a stronger negative correlation (ρ=-0.36, -0.55, -0.45). Conclusion: sRAGE demonstrated a tendency to decrease upon increased severity of periodontitis according to the classifications used. Above all, the correlation with the BOP index, which reflects the current state of periodontitis, was higher in the group with severe periodontitis. This indicates that the current status of periodontitis can be diagnosed through sRAGE.

• Journal of Ginseng Research
• /
• v.37 no.2
• /
• pp.187-193
• /
• 2013

The effect of Korean red ginseng (KRG) on diabetic renal damage was investigated using streptozotocin (STZ)-induced diabetic rats. The diabetic rats showed loss of body weight gain, and increases in kidney weight and urine volume, whereas the oral administration of KRG at a dose of 100 or 250 mg/kg of body weight per day for 28 d prevented these diabetes-induced physiological abnormalities. Among the kidney function parameters, elevated plasma levels of urea nitrogen and creatinine in diabetic control rats tended to be lowered in KRG-treated rats. In addition, administration of KRG at a dose of 100 mg/kg body weight in the diabetic rats showed significant decreases in serum glucose and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), implying that KRG might prevent the pathogenesis of diabetic complications caused by impaired glucose metabolism and oxidative stress. KRG also significantly reduced advanced glycation end product (AGE) formation and secretion from kidney of diabetic rats. Furthermore, KRG decreased the levels of N-(carboxymethyl) lysine and expression of AGE receptor. KRG also reduced the overexpression of cyclooxygenase-2 and inducible nitric oxide synthase in the kidney via deactivation of nuclear factor-kappa B. We also found that KRG prevented STZ-induced destruction of glomerular structure and significantly suppressed high glucose-induced fibronectin production. Taken together, KRG ameliorates abnormalities associated with diabetic nephropathy through suppression of inflammatory pathways activated by TNF-${\alpha}$ and AGEs. These findings indicate that KRG has a beneficial effect on pathological conditions associated with diabetic nephropathy.

• Korean Journal of Pharmacognosy
• /
• v.37 no.2 s.145
• /
• pp.103-109
• /
• 2006

Advanced glycation end products (AGEs) formation plays an important role in the progression of diabetic complications. To develop effective herbal formulations with suppression of diabetic nephropathy, a common complication in diabetic patients, we evaluated inhibitory activities of KIOM-79, a new herbal prescription, on the formation of AGEs using in vitro and in vivo model systems. Effects of KIOM-79 on the expression of AGEs, RAGEs (receptor for Advanced glycation end products), type IV collagen and renal $TGF-{\beta}1$ mRNA was also examined in streptozotocon (STZ)-induced diabetic rats. STZ-induced diabetic rats were treated orally with KIOM-79 (250 and $500\;kg^{-1}$ once a day for 13 weeks). In vitro system KIOM-79 suppressed the formation of AGEs $(18.12\;{\mu}g/ml)$. In STZ-induced diabetic rats showing accumulation of AGE and RAGE, pathological examination revealed that KIOM-79 prevented AGE and RAGE deposition in the kidney. In STZ induced diabetic rats, the expansion of mesangial matrix and the glomerular tufts seemed to be larger than those in normal rats. Howεver, after administration with KIOM-79, mesangial metrix and glomerular volume were decreased, and overexpression of type IV collagen was also decreased. Overexpression of renal $TGF-{\beta}1$ mRNA was inhibited significantly. These results suggest that the KIOM-79 might be an effective herbal prescription to prevent or alleviate the progression of diabetic nephropathy.

• Journal of Industrial and Engineering Chemistry
• /
• v.67
• /
• pp.284-292
• /
• 2018

Receptor for advanced glycation end-products (RAGE) is overexpressed in various cancer cells. In this study, a RAGE-binding peptide (RBP) was conjugated to polyethylenimine (25 kDa, PEI). RBP-conjugated PEI (PEI-RBP) was characterized as a dual-functional reagent, a RAGE-mediated gene carrier and an anti-angiogenic reagent. As a gene carrier, PEI-RBP had higher transfection efficiency to the C6 glioblastoma cells than PEI. As an anti-angiogenic reagent, the pEmpty/PEI-RBP complex reduced RAGE expression on the surface of the C6 glioblastoma cells. Also, the complex reduced the VEGF expression and tube formation of endothelial cells. Therefore, PEI-RBP may be useful for development of glioblastoma therapy.

• The Journal of Korean Medicine
• /
• v.29 no.4
• /
• pp.133-145
• /
• 2008

Objectives: The aim of present study was to investigate recovery effects of Hirudo, which has been used clinically in diabetes therapy. Methods: We established three groups: normal, control, Hirudo, and assigned 6 rats to each group. The normal group was not treated by any process and fed by normal saline. The control & Hirudo groups were administered streptozotocin (STZ) to induce diabetes. Hirudo extract was orally administered to the Hirudo group for 10 days. After 8 weeks, the rats were sacrificed and their body weight, 24hrs urinary protein excretion, glucose, albumin, BUN, creatinine, total-cholesterol, LDL-cholesterol, triglyceride in blood, and level of glycation end-product (AGE) and transforming growth factor (TGF-${\beta}1$) in serum were measured. Morphological profiles and morphometric studies of the kidney cortex, renal transforming growth factor (TGF-${\beta}1$) expression, and renal receptor for advanced glycation end-products (RAGE) expression were studied. Results: The following results were obtained. The protein amount in urine per 24hrs of the Hirudo-treated group as compared to the control group was significantly reduced. The BUN and creatinine level in serum of the Hirudo-treated group as compared to the control group was significantly inhibited. The construction change in kidney of the Hirudo-treated group as compared to the control group was significantly inhibited. The factor of the Hirudo-treated group as compared to the control group was significantly inhibited, which induced the construction change in kidney. Conclusions: The above results suggest that Hirudo partially improved the function of the kidney.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.45 no.2
• /
• pp.151-159
• /
• 2019

Ergothioneine has been known as an excellent antioxidant and a cellular protector against oxidative damage in vivo. In the present study, ergothioneine was demonstrated to possess antioxidant and anti-glycation activities. The radical scavenging activity of ergothioneine enhanced the viability of human dermal fibroblasts (HDFs) exposed to ultraviolet (UV) light. The UVA irradiation increased the proportion of senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) positive cells in comparison with the normal control group. The treatment of UVA-irradiated HDFs with ergothioneine decreased the level of SA-b-gal (by approximately 45% at an ergothioneine concentration of $400{\mu}M$) compared with the UVA-irradiated HDFs. We also found that ergothioneine inhibited production of glyceraldehyde-derived advanced glycation endproducts (AGEs) in a concentration-dependent manner. The ergothioneine educed carboxymethyl-lysine (CML) expression in comparison to the glyoxal treatment. In addition, in the Western blot analysis, treatment of glyoxal-stimulated HDFs with ergothioneine resulted in a dose-dependent decrease in the expression level of the receptor for AGE (RAGE). These results suggest that ergothioneine may have potent anti-aging effects and could be used as a cosmetic material against cellular accumulation of AGEs.

• Biodesign
• /
• v.5 no.3
• /
• pp.122-125
• /
• 2017

Receptor for advanced glycation end products (RAGE) is one of the single transmembrane domain containing receptors and causes various inflammatory diseases including diabetes and atherosclerosis. RAGE extracellular domain has three consecutive IgG-like domains (V-C₁-C₂ domain) which interact with various soluble ligands including heparan sulfate or HMGB1. Studies have shown that each ligand induces different oligomeric forms of RAGE which results in a ligand-specific signal transduction. The structure of mouse RAGE bound to heparan sulfate has been previously determined but the electron density map of heparan sulfate was too ambiguous that the exact position of heparin sulfate could not be defined. Furthermore, the complex structure of human RAGE and heparin sulfate still remains elusive. Therefore, to determine the structure, human RAGE was overexpressed using bacterial expression system and crystallized using the sitting drop method in the condition of 0.1 M sodium acetate trihydrate pH 4.6, 8 % (w/v) polyethylene glycol 4,000 at 290 K. The crystal diffracted to 3.6 Å resolution and the space group is C121 with unit cell parameters a= 206.04 Å, b= 68.64 Å, c= 98.73 Å, α= 90.00°, β= 90.62°, γ= 90.00°.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.7
• /
• pp.2725-2729
• /
• 2015

Background: Transitional cell carcinoma (TCC) and prostate cancer are the most frequent cancers in the male genitourinary tract. Measurement of biological biomarkers may facilitate clinical monitoring and aid early diagnosis of TCC. The aim of the present investigation was to detect the mRNA levels of S100A12 and RAGE (receptor for advanced glycation end products) in patients suffering from bladder TCC. Materials and Methods: To explore the involvement of S100A12 and RAGE genes, total RNA was harvested from cancer tissues and samples obtained from normal non-tumorized urothelium of the same patients. Quantitative PCR (qPCR) was subsequently employed to determine the mRNA levels of S100A12 and RAGE. Results: The results showed that mRNA expression of S100A12 and RAGE was significantly up-regulated in the cancer tissue. Conclusions: According to the results presented in the current study, mRNA expression of S100A12 and RAGE might be as a useful biomarker for TCC. Therefore, this ligand-receptor axis possibly plays important roles in the development of TCC and may serve either as an early diagnostic marker or as a key factor in monitoring of response to treatment. More research is required concerning inhibition of the S100A12-RAGE axis in different cancer models.