Advanced glycation endproducts and bone quality: practical implications for people with type 2 diabetes.

PURPOSE OF REVIEW: Individuals with type 2 diabetes (T2D) are at increased risk of fracture, often despite normal bone density. This observation suggests deficits in bone quality in the setting of abnormal glucose homeostasis. The goal of this article is to review recent developments in our understanding of how advanced glycation end products (AGEs) are incorporated into the skeleton with resultant deleterious effects on bone health and structural integrity in patients with T2D. RECENT FINDINGS: The adverse effects of skeletal AGE accumulation on bone remodeling and the ability of the bone to deform and absorb energy prior to fracture have been demonstrated both at the bench as well as in small human studies; however, questions remain as to how these findings might be better explored in large, population-based investigations. SUMMARY: Hyperglycemia drives systemic, circulating AGE formation with subsequent accumulation in the bone tissue. In those with T2D, studies suggest that AGEs diminish fracture resistance, though larger clinical studies are needed to better define the direct role of longstanding AGE accumulation on bone strength in humans as well as to motivate potential interventions to reverse or disrupt skeletal AGE deposition with the goal of fracture prevention.

AGEs promote calcification of HASMCs by mediating Pi3k/AKT-GSK3ß signaling.

This study aimed to investigate the effects of advanced glycation end products (AGEs) on the calcification of human arterial smooth muscle cells (HASMCs) and to explore whether AGEs can promote the calcification of HASMCs by activating the phosphoinositide 3-kinase (PI3K)/AKT-glycogen synthase kinase 3 beta (GSK3-ß) axis. Cultured HASMCs were divided into five groups: blank control group, dimethyl sulfoxide (vehicle) group, AGEs group, LY294002 (AKT inhibitor) group, and TWS119 (GSK3-ß inhibitor) group. Cells were pretreated with either vehicle, LY294002, or TWS119 for 2 hours followed by incubation with AGEs (25 µg/mL) for 5 days, and the expression levels of proteins in each group were analyzed by western blotting. AGE treatment promoted HASMC calcification, which coincided with increased expression of p-AKT and p-GSK3-ß (serine 9). Also, AGEs upregulated the expression of osteoprotegerin and bone morphogenetic protein, and these effects were suppressed by LY294002 but enhanced by TWS119. In conclusion, AGEs promote calcification of HASMCs, and this effect is ameliorated by inhibition of AKT activity but potentiated by inhibition of GSK3-ß activity. Hence, AGEs trigger HASMC calcification by regulating PI3K/AKT-GSK3-ß signaling.

Serum biomarkers, skin autofluorescence and other methods. Which parameter better illustrates the relationship between advanced glycation end products and arterial stiffness in the general population?

Stiffening of large arteries, clinically manifesting as increased aortic pulse wave velocity (PWV), is an inevitable outcome of aging. Among other mechanisms, impaired glucose metabolism plays an important role, leading to the deposition of advanced glycation end products (AGEs). This process is counterbalanced by the circulating soluble receptor for AGEs (sRAGE). We investigated the association between arterial stiffness on one side and multiple circulating biomarkers and the degree of skin deposition of AGEs on the other. In a cross-sectional design, 867 participants based on a general population sample (Czech post-MONICA studies) were examined. PWV was measured by SphygmoCor device (AtCor Medical Ltd.), while skin AGEs were measured using a dedicated autofluorescence method (AGE Reader mu®). To quantify the circulating status of AGEs, carboxymethyl lysine (CML) and sRAGE concentrations were assessed by ELISA, along with conventional glucose metabolism indicators. When analyzing the whole sample using multiple linear or logistic regression models and after adjustment for potential covariates, a significant association with PWV was found for fasting glycemia, HbA1c, sRAGE, skin AGEs, and the skin AGE-to-sRAGE ratio. Among these parameters, stepwise models identified the strongest association for the skin AGEs and AGE-to-sRAGE ratio, and this was also true when diabetic subjects were excluded. In contrast, neither CML nor its ratio relative to sRAGE showed any association with arterial stiffness. In conclusion, skin AGEs along with their ratio relative to sRAGE were closely associated with arterial stiffness and is a better indicator of the current status of deposited AGEs than other relevant factors.

[Towards Understanding the Pathophysiological Significance of Cytokine Trapping Mediated by Advanced Glycation End Products].

Advanced glycation end products (AGEs) are non-enzymatically formed from sugars or their metabolites with biomolecules. These molecules are formed in vivo, and the formation of AGEs on functional biomolecules was demonstrated to alter their properties. In addition, AGEs were reported to elicit inflammatory reactions by stimulating their endogenous receptors. However, the relationship between AGEs and these phenomena remains unclear. To understand the pathophysiological roles of AGEs, we investigated their action mechanisms at the molecular level. In this study, we found that AGEs can directly interact with tumor necrosis factor-like weak inducer of apoptosis (TWEAK), the cytokine that controls tumor necrosis factor-α (TNF-α)-stimulated inflammatory reactions. This interaction inhibited the action of TWEAK and subsequently increased TNF-α-induced proinflammatory cytokine expression. This raised the possibility that AGEs trap other cytokines and alter their activities. We named this hypothesis "AGE-mediated cytokine trapping". To assess this hypothesis, we next examined the mechanism of AGE-TWEAK interaction. The pull-down assay using the deletion mutant revealed that a relatively large region of TWEAK functions in the interaction with AGEs, suggesting that it is difficult to explore other cytokines capable of interacting with AGEs using TWEAK sequence similarity. Therefore, to find novel AGE-cytokine interactions, we performed comprehensive screening using a protein array and found several candidates. To generalize "AGE-mediated cytokine trapping", detailed studies using these candidates are now in progress.

RAGE against the stress: Mitochondrial suppression in hypometabolic hearts.

The wood frog (Rana sylvatica) can tolerate full body freezing in winter. As a protective response, wood frogs dehydrate their cells and accumulate large quantities of glucose as an intracellular cryoprotectant. Freezing causes ischemia since blood delivery to organs is interrupted. Fascinatingly, wood frogs can tolerate dehydration, extreme hyperglycemia, and anoxia independently of freezing. In response to low oxygen levels, wood frogs strategically reduce their metabolic rates and allocate the finite amount of intracellular fuel available to pro-survival processes while reducing or interrupting all others. In this study, the involvement of advanced glycation end products (AGEs) and the high mobility group box 1 (HMGB1) protein in activating RAGE (AGE receptor) were investigated. The results show that freezing, anoxia and dehydration induced the expression of total HMGB1 and its acetylation in the heart. RAGE levels were induced in response to all stress conditions, which resulted in differential regulation of the ETS1 transcription factor. While the nuclear localization of total ETS1 was not affected, the DNA binding activity of total and its active form increased in response to freezing and dehydration but not in response to anoxia. Current results indicate that ETS1 acts as a transcriptional activator for peroxiredoxin 1 in response to freezing but acts as a transcriptional repressor of several nuclear-encoded mitochondrial genes in response to all stresses. Altogether, current results show that the HMGB1/RAGE axis may activate ETS1 and that this activation could result in both transcriptional activation and/or repression in a stress-dependent manner.

Advanced glycation end products reduce macrophage-mediated killing of Staphylococcus aureus by ARL8 upregulation and inhibition of autolysosome formation.

Staphylococcus aureus, a pathogen most frequently found in diabetic foot ulcer infection, was recently suggested as an intracellular pathogen. Autophagy in professional phagocytes like macrophages allows selective destruction of intracellular pathogens, and its dysfunction can increase the survival of internalized pathogens, causing infections to worsen and spread. Previous works have shown that S. aureus infections in diabetes appeared more severe and invasive, and coincided with the suppressed autophagy in dermal tissues of diabetic rat, but the exact mechanisms are unclear. Here, we demonstrated that accumulation of advanced glycation end products (AGEs) contributed to the diminished autophagy-mediated clearance of S. aureus in the macrophages differentiated from PMA-treated human monocytic cell line THP-1. Importantly, infected macrophages showed increased S. aureus containing autophagosome, but the subsequent fusion of S. aureus containing autophagosome and lysosome was suppressed in AGEs-pretreated cells, suggesting AGEs blocked the autophagic flux and enabled S. aureus survival and escape. At the molecular level, elevated lysosomal ARL8 expression in AGEs-treated macrophages was required for AGEs-mediated inhibition of autophagosome-lysosome fusion. Silencing ARL8 in AGEs-treated macrophages restored autophagic flux and increased S. aureus clearance. Our results therefore demonstrate a new mechanism, in which AGEs accelerate S. aureus immune evasion in macrophages by ARL8-dependent suppression of autophagosome-lysosome fusion and bactericidal capability.

Advanced Glycation End Products and Receptor (RAGE) Promote Wound Healing of Human Corneal Epithelial Cells.

Purpose: We used a human corneal epithelial cell (HCE) line to determine the involvement of the advanced glycation end products (AGEs) / receptor for AGEs (RAGE) couple in corneal epithelium wound healing. Methods: After wounding, HCE cells were exposed to two major RAGE ligands (HMGB1 and AGEs), and wound healing was evaluated using the in vitro scratch assay. Following wound healing, the HCE cells were used to study the influence of the RAGE ligands on HCE proliferation, invasion, and migration. Activation of the nuclear factor (NF)-κB signaling pathway by the AGEs/RAGE couple was tested using a luciferase reporter assay. Functional transcriptional regulation by this pathway was confirmed by quantification of expression of the connexin 43 target gene. For each experiment, specific RAGE involvement was confirmed by small interfering RNA treatments. Results: AGEs treatment at a dose of 100 µg/mL significantly improved the wound healing process in a RAGE-dependent manner by promoting cell migration, whereas HMGB1 had no effect. No significant influence of the AGEs/RAGE couple was observed on cell proliferation and invasion. However, this treatment induced an early activation of the NF-κB pathway and positively regulated the expression of the target gene, connexin 43, at both the mRNA and protein levels. Conclusions: Our results demonstrate that the RAGE pathway is activated by AGEs treatment and is involved in the promotion of corneal epithelial wound healing. This positive action is observed only during the early stages of wound healing, as illustrated by the quick activation of the NF-κB pathway and induction of connexin 43 expression.

[The role of carbonyl stress in the development of diabetic complications]. / A karbonilstressz szerepe a diabetes szövodményeinek kialakulásában.

The relationship between the potentially developing complications of the 451 million people affected by diabetes and hyperglycaemia can be based on the enhanced generation of advanced glycation endproducts and the more intensive oxidative and carbonyl stress. Advanced glycation endproducts generated partly due to carbonyl stress play an important role in the pathogenesis of diabetic complications such as elevated arterial thickness, vascular permeability, enhanced angiogenesis or the more rigid vessels induced nephropathy, neuropathy, retinopathy. Furthermore, the elevated thrombocyte aggregation, the reduced fibrinolysis induced elevated coagulation, and the atherosclerosis or the mitochondrial dysfunction are important as well. The most potent target of both the non-oxidative and oxidative generation of advanced glycation endproducts can be the scavenging of α,ß-unsaturated aldehydes. Although, aminoguanidine, the prototype of scavenger molecules, showed protection in different animal models, it failed in the human clinical studies. Finally, the clinical studies were terminated almost 20 years ago. The endogen dipeptide L-carnosine was also expected to mitigate the complications due to carbonyl stress. However, its clinical significance was limited by the serum carnosinases and by the consequent low serum stability and bioavailability. The carnosinase resistance of the molecule can be achieved by the change of the carboxyl group of the molecule to hydroxyl group. At the same time, the biosafety and the carbonyl stress scavenging activity of the molecule could be preserved. Although clinical studies could not be performed in the last six months, on the basis of the in vitro and in vivo results, carnosinole seems to be a promising compound to mitigate and prevent the diabetic complications. Thus it is worth to the attention of the clinicians. Orv Hetil. 2019; 160(40): 1567-1573.

Advanced Glycation End-Products Can Activate or Block Bitter Taste Receptors.

Bitter taste receptors (T2Rs) are expressed in several tissues of the body and are involved in a variety of roles apart from bitter taste perception. Advanced glycation end-products (AGEs) are produced by glycation of amino acids in proteins. There are varying sources of AGEs, including dietary food products, as well as endogenous reactions within our body. Whether these AGEs are T2R ligands remains to be characterized. In this study, we selected two AGEs, namely, glyoxal-derived lysine dimer (GOLD) and carboxymethyllysine (CML), based on their predicted interaction with the well-studied T2R4, and its physiochemical properties. Results showed predicted binding affinities (Kd) for GOLD and CML towards T2R4 in the nM and µM range, respectively. Calcium mobilization assays showed that GOLD inhibited quinine activation of T2R4 with IC50 10.52 ± 4.7 µM, whilst CML was less effective with IC50 32.62 ± 9.5 µM. To characterize whether this antagonism was specific to quinine activated T2R4 or applicable to other T2Rs, we selected T2R14 and T2R20, which are expressed at significant levels in different human tissues. A similar effect of GOLD was observed with T2R14; and in contrast, GOLD and CML activated T2R20 with an EC50 of 79.35 ± 29.16 µM and 65.31 ± 17.79 µM, respectively. In this study, we identified AGEs as novel T2R ligands that caused either activation or inhibition of different T2Rs.

Identification of a novel advanced glycation end product derived from lactaldehyde.

Advanced glycation end products (AGEs) are implicated in the development of diabetic complications via the receptor for AGEs (RAGE). We have reported that the 3-hydroxypyridinium (3HP)-containing AGEs derived from α-hydroxyaldehydes physically interact with RAGE and show cytotoxicity. Lactaldehyde (LA) is formed from a reaction between threonine and myeloperoxidase, but no LA-derived AGEs have been characterized. Here, we identify the structure and physiological effects of an AGE derived from LA. We isolated a novel 3HP derivative, 2-acetamido-6-(3-hydroxy-5-methyl-pyridin-1-ium-1-yl)hexanoate, named as N-acetyl-LAPL (lactaldehyde-derived pyridinium-type lysine adduct), from a mixture of LA with Nα-acetyl-L-lysine. LAPL was also detected in the LA-modified protein. LAPL elicited toxicity in PC12 neuronal cells, but the effect was suppressed by the soluble form of RAGE as a decoy receptor. Moreover, surface plasmon resonance-based analysis revealed that LAPL specifically binds to recombinant RAGE. These results indicate that LA generates an AGE containing the 3HP moiety and contributes to RAGE-dependent cytotoxicity. Abbreviations: AGEs: advanced glycation end products; RAGE: receptor for advanced glycation end products; 3HP: 3-hydroxypyridinium; LA: lactaldehyde; LAPL: lactaldehyde-derived pyridinium-type lysine adduct; BSA: bovine serum albumin; GLAP: glyceraldehyde-derived pyridinium; MPO: myeloperoxidase; HFBA: heptafluorobutyric acid; TFA: trifluoroacetic acid; HPLC: high performance liquid chromatography; LC-ESI-QTOF-MS: liquid chromatography-electrospray ionization-quadrupole time-of-flight-mass spectrometry; NMR: nuclear magnetic resonance; LA-BSA: lactaldehyde-modified bovine serum albumin; PBS: phosphate buffered saline, GST, glutathione S-transferase; SPR: surface plasmon resonance; OP-lysine: 2-ammonio-6-(3-oxidopyridinium-1-yl)hexanoate; GLO1: glyoxalase 1; MG, methylglyoxal.

Targeting chronic innate inflammatory pathways, the main road to prevention of osteoarthritis progression.

Osteoarthritis (OA) is a chronic joint disease characterized by cartilage degradation, osteophyte formation, subchondral bone sclerosis, and synovitis. Systemic factors such as obesity and the components of the metabolic syndrome seem to contribute to its progression. Breakdown of cartilage ensues from an altered balance between mechanical overload and its absorption by this tissue. There is in this context a status of persistent local inflammation by means of the chronic activation of innate immunity. A broad variety of danger-associated molecular patterns inside OA joint are able to activate pattern recognition receptors, mainly TLR (toll-like receptor) 2 and 4, which are overexpressed in the OA cartilage. Chronic activation of innate immune responses in chondrocytes results in a robust production of pro-inflammatory cytokines and chemokines, as well as of tissue-destructive enzymes, downstream of NF-κB and MAPK (mitogen activated protein kinase) dependent pathways. Besides, the toxic effects of an excess of glucose and/or fatty acids, which share the same pro-inflammatory intracellular signalling pathways, may add fuel to the fire. Not only high concentrations of glucose can render cells prone to inflammation, but also AGEs (advanced glycation end products) are integrated into the TLR signalling network through their own innate immune receptors. Considering these mechanisms, we argue for the control of both primary inflammation and proteolytic catabolism as a preventive strategy in OA, instead of focusing treatment on the enhancement of anabolic responses. Even though this approach would not return to normal already degraded cartilage, it nonetheless might avoid damage extension to the surrounding tissue.

Impact of advanced glycation end products (AGEs) signaling in coronary artery disease.

Coronary artery disease remains the leading cause of mortality in adult diabetic population with however, a high predominance also in non-diabetic subjects. In search of common molecular mechanisms and metabolic by-products with potential pathogenic role, increased advanced glycation end products (AGEs) present a critical biomarker for CAD development in both cases. Interaction of AGEs with their transmembrane cell receptor, RAGE in endothelial and smooth muscle cells as well as in platelets, activates intracellular signaling that leads to endothelial injury, modulation of vascular smooth muscle cell function and altered platelet activity. Furthermore, tissue accumulation of AGEs affects current treatment approaches being involved in stent restenosis. The present review provides an update of AGE-induced molecular mechanisms involved in CAD pathophysiology while it discusses emerging therapeutic interventions targeting AGE reduction and AGE-RAGE signaling with beneficial clinical outcome.

Zafirlukast attenuates advanced glycation end-products (AGEs)-induced degradation of articular extracellular matrix (ECM).

Zafirlukast, a leukotriene receptor antagonist, has been shown to exert a wide range of effects including anti-asthmatic, anti-inflammatory and oral anti-bacterial. Osteoarthritis is one of the most prevalent age-related public health burdens in the modern world. In the present study, we applied zafirlukast in the treatment of human primary chondrocytes and found that it exerts potent anti-osteoarthritic effects. Zafirlukast inhibited AGEs-induced degradation of the articular extracellular matrix by suppressing expression of MMPs, ADAMTS, NOX-4, generation of ROS, and activation of NF-κB via the IκBα/JNK/AP-1 pathway through targeted inhibition of CysLTR1. These findings suggest that zafirlukast possesses a protective effect against AGEs- induced damage and dysfunction in human chondrocytes.

Data Linking Diabetes Mellitus and Atrial Fibrillation-How Strong Is the Evidence? From Epidemiology and Pathophysiology to Therapeutic Implications.

According to estimates, around 5% of the world population has hazel eyes. And there are about as many people with diabetes mellitus (DM). Red hair occurs naturally in up to 2% of the human population. And about as many people are estimated to have atrial fibrillation (AF). If a hazel eyed person with red hair does not surprise us, should a diabetic patient with AF? Accumulating epidemiologic data suggest, however, that the DM-AF association may be more than a simple coincidence. But, how strong is this evidence? Experimental studies bring evidence for a DM-induced atrial proarrhythmic remodelling. But how relevant are these data for the clinical setting? In this review, we aim to provide a critical analysis of the existing clinical and experimental, epidemiologic, and mechanistic data that bridge DM and AF, we emphasize a number of questions that remain to be answered, and we identify hotspots for future research. The therapeutic implications of the DM-AF coexistence are also discussed, with a focus on rhythm control and on conventional and DM-specific upstream therapies for AF management.

[The research progress of relationship between advanced glycation end products and diabetic keratopathy].

Diabetic keratopathy is a common ocular complication of patients with a long-term history of diabetes and it will have a negative effect on the visual quality and function. A study reported that the incidence of diabetic keratopathy in diabetic patients ranged from 47% to 64%, but the precise underlying pathogenesis remains unclear. There is evidence that advanced glycation end products contribute substantially to the onset and progress of various diabetic complications and it is a key factor for the mechanism of the hyperglycemic memory. This review focuses primarily on the present research state and prospect of advanced glycation end products and their role in the pathological changes of the cornea. (Chin J Ophthalmol, 2018, 54: 475-480).

Gene-disease associations identify a connectome with shared molecular pathways in human cholangiopathies.

Cholangiopathies are a diverse group of progressive diseases whose primary cell targets are cholangiocytes. To identify shared pathogenesis and molecular connectivity among the three main human cholangiopathies (biliary atresia [BA], primary biliary cholangitis [PBC], and primary sclerosing cholangitis [PSC]), we built a comprehensive platform of published data on gene variants, gene expression, and functional studies and applied network-based analytics in the search for shared molecular circuits. Mining the data platform with largest connected component and interactome analyses, we validated previously reported associations and identified essential and hub genes. In addition to disease-specific modules, we found a substantial overlap of disease neighborhoods and uncovered a group of 34 core genes that are enriched for immune processes and abnormal intestine/hepatobiliary mouse phenotypes. Within this core, we identified a gene subcore containing signal transduction and activator of transcription 3, interleukin-6, tumor necrosis factor, and forkhead box P3 prominently placed in a regulatory connectome of genes related to cellular immunity and fibrosis. We also found substantial gene enrichment in the advanced glycation endproduct/receptor for advanced glycation endproducts (RAGE) pathway and showed that RAGE activation induced cholangiocyte proliferation. Conclusion: Human cholangiopathies share pathways enriched by immunity genes and a molecular connectome that links different pathogenic features of BA, PBC, and PSC. (Hepatology 2018;67:676-689).

Polycystic ovarian syndrome-associated cardiovascular complications: An overview of the association between the biochemical markers and potential strategies for their prevention and elimination.

Polycystic ovarian syndrome (PCOS) is associated with multiple cardiovascular risk factors (CVRF) including endothelial dysfunction (ED) and presence of metabolic syndrome (MS). The probable reason suggested for elevated CVRF in PCOS is oxidative stress (OS), which is an integral factor in cardiometabolic complications (CMC) seen in PCOS women. The interrelated mechanisms by which CVRF instigate clinical manifestation plays a crucial role in identification of a strategy to treat different comorbidities in PCOS. The existing treatment for PCOS mostly focuses on management of individual disorders, however, therapeutic strategies or novel targets to address cardiovascular complications in PCOS deserve extensive analysis.

Advanced glycation end products attenuate the function of tumor necrosis factor-like weak inducer of apoptosis to regulate the inflammatory response.

Advanced glycation end products (AGEs) are formed from the non-enzymatic glycation reaction of reducing sugars or their metabolites with the free amino groups of several biomolecules and are known to play pathophysiological roles in various inflammatory diseases. In an earlier study, it was suggested that tumor necrosis factor-like weak inducer of apoptosis (TWEAK) has a unique role to regulate the tumor necrosis factor α (TNFα)-induced inflammatory response. In this study, we investigated the effect of the AGEs-TWEAK interaction on proinflammatory signaling responses in endothelial cells and the influence of AGEs on the cellular function of TWEAK in the inflammatory process. The effect of AGEs on the TWEAK/TNFα-induced gene expression of interleukin-8 (IL-8) was determined by real-time RT-PCR in endothelial-like EA.hy.926 cells. The pull-down assay was performed using recombinant His-tagged TWEAK and AGEs. The NF-κB activation was analyzed by Western blotting with canonical and non-canonical pathway-specific antibodies. AGEs dose-dependently inhibited TWEAK-induced IL-8 gene expression, whereas AGEs themselves had almost no effect on IL-8 expression. AGEs were found to bind directly to TWEAK in the pull-down assay. TNFα-induced IL-8 production and canonical NF-κB activation were suppressed by TWEAK pretreatment, whereas TWEAK-induced non-canonical NF-κB activation was enhanced by pretreatment. These effects induced by TWEAK pretreatment were abolished by the co-addition of AGEs. Our findings suggest that AGEs attenuate the function of TWEAK to regulate the TNFα-induced inflammatory responses, which provide important clues for understanding the significance of the AGEs-TWEAK interaction in inflammatory processes.

Role of moesin, Src, and ROS in advanced glycation end product-induced vascular endothelial dysfunction.

The disruption of endothelial integrity and the occurrence of angiogenesis in response to AGEs contribute greatly to micro- and macrovascular complications associated with DM. Among human dermal, brain, and retinal vascular ECs, activation of ERM, moesin, by phosphorylation of Thr-558 is involved in AGE-induced hyperpermeability and angiogenesis via the Rho and ROCK (Rho/ROCK) and p38 pathways. Src also plays an important role in AGE-induced endothelial barrier dysfunction by phosphorylating moesin, VE-cadherin, and FAK. Furthermore, recent studies have demonstrated that ROS serve as a key mediator of the AGE-induced endothelial response. ROS inhibition would greatly benefit ECs. This review focuses on the role of moesin in microvascular permeability and angiogenesis, and on the involvement of Src and ROS in endothelial barrier disruption.

Aging ovary and the role for advanced glycation end products.

OBJECTIVE: The hypothalamic gonadotropin-releasing hormone pulse generator, the pituitary gonadotropes, the ovaries, and the uterus play a crucial role in female fertility. A decline in reproductive performance represents a complex interplay of actions at all levels of the hypothalamic-pituitary-ovarian axis. Recently, in the field of female reproductive aging attention is drawn to the carbonyl stress theory. Advanced glycation end products (AGEs) contribute directly to protein damage, induce a chain of oxidative stress (OS) reactions, and increase inflammatory reactions. Here, we highlight some of the mechanisms underlying glycation damage in the ovary. METHODS: Searches of electronic databases were performed. Articles relevant to possible role of OS, AGEs, and receptor for AGE (RAGE) in aging ovary were summarized in this interpretive literature review. RESULTS: Follicular microenvironment undergoes an increase in OS with aging. Data support the role of OS in ovulatory dysfunction because AGEs are well-recognized mediators of increased OS. RAGE and AGE-modified proteins with activated nuclear factor-kappa B are expressed in human ovarian tissue. It was suggested that accumulation of AGEs products at the level of the ovarian follicle might trigger early ovarian aging or could be responsible for reduced glucose uptake by granulosa cells, potentially altering follicular growth. Moreover, impaired methylglyoxal detoxification causing relevant damage to the ovarian proteome might be one of the mechanisms underlying reproductive aging. CONCLUSIONS: Further investigation of the role for the AGE-RAGE axis in the ovarian follicular environment is needed, and results could relate to assisted reproduction technology outcomes and new measures of ovarian reserve.