Antioxidants inhibit advanced glycosylation end-product-induced apoptosis by downregulation of miR-223 in human adipose tissue-derived stem cells.
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ABSTRACT:
SUBMITTER: Wang Z
PROVIDER: S-EPMC4786853 | biostudies-other | 2016 Mar
REPOSITORIES: biostudies-other
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Project description:AimsOur objective was to investigate the association of common variants in the coding region of advanced glycosylation end-product specific receptor (RAGE) and the prognosis of heart failure (HF).Methods and resultsA total of 3394 HF patients were continuously enrolled from January 2009 to August 2018 with a median follow-up of 20.4 months. Additionally, 2861 healthy subjects also participated in the study. By sequencing these two groups, we identified a common functional missense variant rs2070600 in the coding region of RAGE, which showed a significant association with the prognosis of HF [hazard ratio = 0.53, 95%, confidence interval (CI) = 0.30-0.94, P = 0.03], but no association with the risk of HF (odds ratio = 0.52, 95%, CI = 0.66-1.04, P = 0.106). A series of functional assays revealed that rs2070600-A, but not -G allele, suppressed the expression of RAGE protein by facilitating the binding of miR-125a-3p. Furthermore, the RAGE messenger RNA levels of human peripheral blood lymphocytes were reduced in subjects with the rs2070600-AA genotype compared with subjects with the rs2070600-GG or -AG genotypes. Additionally, our Western blot results from human heart tissue showed increased RAGE expression in HF samples compared with that in healthy donors.ConclusionsOur results demonstrate that the common missense variant rs2070600-A allele is associated with a reduced risk of cardiovascular death and cardiac transplantation by facilitating the binding of miR-125a-3p.
| S-EPMC7755010 | biostudies-literature
Project description:Advanced glycosylation end product-specific receptor (AGER) signaling has been implicated in atherosclerosis. The aim of this study was to evaluate whether a common genetic variation in the AGER gene is associated with cardiovascular (CV) death. We included 1304 older men who were genotyped for rs1035798:C>T, which is a single nucleotide polymorphism (SNP) mapped to the third intron of AGER. Cox proportional hazard analysis was used to estimate the association of rs1035798:C>T with CV death. In addition we analyzed total RNA extracted from carotid atherosclerosis biopsies of 18 patients that did or did not have recent symptoms of cerebral embolization by quantitative real-time reverse transcription PCR (qRT-PCR). The minor T-allele of rs1035798:C>T was found to be associated with CV death under dominant (HR = 1.43, 95% CI: 1.01-2.02, P = 0.04) and recessive (HR = 2.05, 95% CI: 1.11-3.81, P = 0.02) models of inheritance even after adjustment for traditional cardiovascular risk factors. No association was found between rs1035798:C>T and non-CV death. qRT-PCR results suggested that median relative expression of AGER isoform 1 and isoform 6 transcripts were approximately 6- (P = 0.01) and 2-fold (P = 0.02) greater, respectively, within carotid biopsies of symptomatic compared to asymptomatic patients. These data suggest that the minor (T) allele of rs1035798:C>T represents an independent susceptibility factor for CV death. The expression of AGER isoforms is different in atheroma from patients with recent symptoms. Further studies are needed to investigate if rs1035798:C>T influences the alternative splicing of AGER.
| S-EPMC4520603 | biostudies-literature
Project description:Diabetes mellitus is frequently accompanied by chronic complications like delayed wound healing, which is consider to be attributed to the accumulation of advanced glycosylation end product (AGE). However, the impacts of AGE on epidermal stem cells (ESCs) are largely unknown. This study aims to address the influence and mechanism of AGE on ESCs. ESCs isolated from rats were cultured in AGE-modified bovine serum albumin and transfected with small interfering RNA to knock down AGE-specific receptor (AGER). Expression of stem cell markers integrin β1 (ITGB1) and keratin 19 (KRT19), cell viability, apoptosis and reactive oxygen species (ROS) were examined. Wnt pathway-related factors Wnt family member 1 (WNT1), WNT3A, β-catenin, v-myc avian myelocytomatosis viral oncogene homolog (MYC), cyclin D1 (CCND1) and matrix metallopeptidase 7 (MMP7) were quantified. The interaction between forkhead box O1 (FOXO1) and β-catenin was assessed by co-immunoprecipitation. Results indicated that AGE down-regulated ITGB1 and KRT19 expression, suppressed ESC viability and promoted apoptosis, and ROS level (P < 0.01), implying decreased capacities of ESCs. AGE also promoted AGER and FOXO1, while AGER knockdown had the opposite effects. Moreover, AGER knockdown elevated the level of WNT1, WNT3A, MYC, CCND1 and MMP7 that were suppressed by AGE (P < 0.01). Immunoprecipitation analysis showed that FOXO1 could compete with lymphoid enhancer binding factor 1 to interact with β-catenin, which might help to elucidate the mechanism of AGE repressing ESCs. This study helps to understand the mechanism of accumulated AGE in affecting ESC capacities, and provides potential therapeutic targets to meliorate diabetic wound healing.
| S-EPMC5209507 | biostudies-literature
Project description:BACKGROUND: Both apoptosis and caspase-3 activity in adipose tissue-derived stem cells play an important role in the therapeutic process of diabetes patients. The purpose of this study was to investigate the effect of advanced glycation end products-human serum albumin (AGE-HSA) on apoptosis in human adipose tissue-derived stem cells (ADSCs) and to characterize the signal transduction pathways activated by AGEs that are involved in apoptosis regulation. RESULTS: AGE-HSA promoted apoptosis and caspase-3 activity in ADSCs. However, the effects of AGE-HSA were significantly attenuated by an inhibitor of p38 MAPK, but not by inhibitors of JNK MAPK or ERK MAPK. AGE-HSA also upregulated the expression of RAGE. Silencing of the RAGE gene inhibited AGE-HSA-induced apoptosis, and activation and expression of phosphorylated p38 MAPK. CONCLUSIONS: These results suggest that AGE-HSA promote the apoptosis of ADSCs in vitro via a RAGE-dependent p38 MAPK pathway.
| S-EPMC4429817 | biostudies-other
Project description:Advanced glycation end products (AGEs) are a heterogeneous group of molecules that emerge from the condensation of sugars and proteins through the Maillard reaction. Despite a significant number of studies showing strong associations between AGEs and the pathologies of aging-related illnesses, it has been a challenge to establish AGEs as causal agents primarily due to the lack of tools in reversing AGE modifications at the molecular level. Herein, we show that MnmC, an enzyme involved in a bacterial tRNA-modification pathway, is capable of reversing the AGEs carboxyethyl-lysine (CEL) and carboxymethyl-lysine (CML) back to their native lysine structure. Combining structural homology analysis, site-directed mutagenesis, and protein domain dissection studies, we generated a variant of MnmC with improved catalytic properties against CEL in its free amino acid form. We show that this enzyme variant is also active on a CEL-modified peptidomimetic and an AGE-containing peptide that has been established as an authentic ligand of the receptor for AGEs (RAGE). Our data demonstrate that MnmC variants are promising lead catalysts toward the development of AGE-reversal tools and a better understanding of AGE biology.
| S-EPMC6768434 | biostudies-literature
Project description:BackgroundAdvanced glycation end products (AGEs) promote adverse health effects and may contribute to the multi-system functional decline observed in aging. Diet is a major source of AGEs, and foods high in protein may increase circulating AGE concentrations. However, epidemiological evidence that high-protein diets increase AGEs is lacking.ObjectivesWe examined whether dietary protein intake was associated with serum concentrations of the major AGE carboxymethyl-lysine (CML) and the soluble receptor for AGEs (sRAGE) in 2439 participants from the Health, Aging, and Body Composition study (mean age, 73.6 ± 2.9 y; 52% female; 37% black).MethodsCML and sRAGE were measured by ELISA, and the CML/sRAGE ratio was calculated. Protein intake was estimated using an interviewer-administered FFQ and categorized based on current recommendations for older adults: <0.8 g/kg/d (n = 1077), 0.8 to <1.2 g/kg/d (n = 922), and ≥1.2 g/kg/d (n = 440). Associations between protein intake and AGE-RAGE biomarkers were examined using linear regression models adjusted for demographics, height, lifestyle behaviors, prevalent disease, cognitive function, inflammation, and other dietary factors.ResultsCML concentrations were higher in individuals with higher total protein intake (adjusted least squares mean ± SE: <0.8 g/kg/d, 829 ± 17 ng/ml; 0.8 to <1.2 g/kg/d, 860 ± 15 ng/ml; ≥1.2 g/kg/d, 919 ± 23 ng/ml; P for trend = 0.001), as were sRAGE concentrations (<0.8 g/kg/d, 1412 ± 34 pg/ml; 0.8 to <1.2 g/kg/d, 1479 ± 31 pg/ml; ≥1.2 g/kg/d, 1574 ± 47 pg/ml; P for trend < 0.0001). Every 0.1 g/kg/d increment in total protein intake was associated with a 13.3 ± 3.0 ng/ml increment in CML and a 22.1 ± 6.0 pg/ml increment in sRAGE (P < 0.0001 for both). Higher CML and sRAGE concentrations were also associated with higher intakes of both animal and vegetable protein (all P values ≤ 0.01). There were no significant associations with the CML/sRAGE ratio.ConclusionsHigher dietary protein intake was associated with higher CML and sRAGE concentrations in older adults; however, the CML/sRAGE ratio remained similar across groups.
| S-EPMC7727487 | biostudies-literature
Project description:Nonenzymatic protein glycation results in the formation of advanced glycation end products (AGEs) that are implicated in the pathology of diabetes, chronic inflammation, Alzheimer's disease, and cancer. AGEs mediate their effects primarily through a receptor-dependent pathway in which AGEs bind to a specific cell surface associated receptor, the Receptor for AGEs (RAGE). N(?)-carboxy-methyl-lysine (CML) and N(?)-carboxy-ethyl-lysine (CEL), constitute two of the major AGE structures found in tissue and blood plasma, and are physiological ligands of RAGE. The solution structure of a CEL-containing peptide-RAGE V domain complex reveals that the carboxyethyl moiety fits inside a positively charged cavity of the V domain. Peptide backbone atoms make specific contacts with the V domain. The geometry of the bound CEL peptide is compatible with many CML (CEL)-modified sites found in plasma proteins. The structure explains how such patterned ligands as CML (CEL)-proteins bind to RAGE and contribute to RAGE signaling.
| S-EPMC3150472 | biostudies-literature
Project description:Background: The osteogenic differentiation of vascular smooth muscle cell (VSMCs) is important for the development of vascular calcification (VC), particularly in diabetes. Exosomes derived from Mesenchymal Stromal Cells (MSCs) are effective against cardiovascular diseases, yet their role in VC remains unclear. Advanced glycation end products (AGEs) inhibit bone marrow stromal cell osteogenesis by targeting osteogenesis-associated genes. Thus, we investigated the role of exosomes derived from MSCs pretreated with AGEs-BSA in VC and its potential mechanisms. Methods: Primary VSMCs and MSCs were isolated from the aorta and bone marrow of Sprague-Dawley rats, respectively. VSMCs were cultured with AGEs-BSA to induce osteogenic differentiation. Exosomes were harvested from MSCs by ultracentrifugation. MSCs and VSMCs were cocultured in Transwells, and exosomes were added to VSMC culture medium to assess their effects on osteogenic differentiation. Double luciferase reporter assay was applied to confirm that miR-146a directly targets the 3' UTR of the thioredoxin-interacting protein (TXNIP) gene. Results: Pretreatment of VSMCs with AGEs-BSA increased the expression of thioredoxin-interacting protein (TXNIP) by inhibiting that of miR-146a, resulting in enhanced ROS production and VSMC calcification. By contrast, the expression of miR-146a in MSCs was increased by AGEs-BSA treatment. Thus, miR-146a was transferred from AGEs-BSA-pretreated or miR-146a-transfected MSCs to VSMCs via exosomes. After coculture with miR-146a-containing exosomes, the AGEs-BSA-mediated increase in VSMC calcification was diminished, accompanied by decreased TXNIP expression and ROS production. Furthermore, TXNIP overexpression counteracted the anti-calcification effects of MSC-derived miR-146a-containing exosomes. In addition, TXNIP was identified as a target gene of miR-146a, and the results of double luciferase reporter assay confirmed that TXNIP was the direct target gene of miR-146a. Conclusions: Exosomes secreted by MSCs pretreated with AGEs-BSA contained a high level of miR-146a, which was transferred to VSMCs and inhibited AGEs-BSA-induced calcification in a TXNIP-dependent manner. Thus, miR-146a-containing exosomes may be a potential therapeutic target for VC.
| S-EPMC6160580 | biostudies-literature
Project description:Ticks are notorious hematophagous ectoparasites and vectors of many deadly pathogens. As an effective vector, ticks must break the strong barrier provided by the skin of their host during feeding, and their saliva contains a complex mixture of bioactive molecules that paralyze host defenses. The receptor for advanced glycation end products (RAGE) mediates immune cell activation at inflammatory sites and is constitutively and highly expressed in skin. Here, we demonstrate that longistatin secreted with saliva of the tick Haemaphysalis longicornis binds RAGE and modulates the host immune response. Similar to other RAGE ligands, longistatin specifically bound the RAGE V domain, and stimulated cultured HUVECs adhered to a longistatin-coated surface; this binding was dramatically inhibited by soluble RAGE or RAGE siRNA. Treatment of HUVECs with longistatin prior to stimulation substantially attenuated cellular oxidative stress and prevented NF-?B translocation, thereby reducing adhesion molecule and cytokine production. Recombinant longistatin inhibited RAGE-mediated migration of mouse peritoneal resident cells (mPRCs) and ameliorated inflammation in mouse footpad edema and pneumonia models. Importantly, tick bite upregulated RAGE ligands in skin, and endogenous longistatin attenuated RAGE-mediated inflammation during tick feeding. Our results suggest that longistatin is a RAGE antagonist that suppresses tick bite-associated inflammation, allowing successful blood-meal acquisition from hosts.
| S-EPMC4191044 | biostudies-literature
Project description:Polycystic ovary syndrome (PCOS) is a chronic metabolic disease that is associated with obesity and adipose tissue dysfunction. This study aimed to explore the roles of Dicer (an enzyme that processes primary microRNAs) and microRNAs in PCOS. Protein levels were detected by western blotting, and mRNA and microRNA levels were detected by RT-PCR. Dicer-deficient pre-adipocytes were established by lentiviral transfection, and an miR-223 mimic and miR-223 inhibitor were used to overexpress and inhibit miR-223, respectively. 3T3-L1 cells were induced to differentiate into mature adipocytes by IBMX, insulin, and dexamethasone. The degree of differentiation was determined by oil red O staining. An insulin resistance model was established by exposing mature adipocytes to excessive glucose and insulin. The protein levels of Dicer and Ago2 in adipose tissues of PCOS patients were significantly lower than those in control females. A Dicer-deficient 3T3-L1 cell model was successfully established, whose proliferation was inhibited significantly. Insulin-resistant mature adipocytes expressed significantly less Dicer protein than control cells. The differentiation of Dicer-deficient 3T3-L1 cells and their expression of miR-223 and marker genes associated with adipose differentiation were reduced significantly. Furthermore, 3T3-L1 cells showed a weaker ability to develop into mature adipocytes when miR-223 expression was inhibited. An miR-223 mimic was used to recover the differentiation block induced by Dicer deficiency. This rescued the expression of genes associated with adipose differentiation, although the differentiation block was not efficiently rescued. It is concluded that insulin resistance may contribute to the decreased levels of Dicer protein in adipose tissue of PCOS patients. This suggests that dysfunction of Dicer plays a significant role in obesity of PCOS patients. miR-223 is a key factor in Dicer-regulated adipose differentiation, and other microRNAs may be involved in the process.
| S-EPMC6885226 | biostudies-literature