Advanced glycation end products: sparking the development of diabetic vascular injury

Metabolic remodelling in atrial fibrillation: manifestations, mechanisms and clinical implications

Atrial fibrillation (AF) is a continually growing health-care burden that often presents together with metabolic disorders, including diabetes mellitus and obesity. Current treatments often fall short of preventing AF and its adverse outcomes. Accumulating evidence suggests that metabolic disturbances can promote the development of AF through structural and electrophysiological remodelling, but the underlying mechanisms that predispose an individual to AF are aetiology-dependent, thus emphasizing the need for tailored therapeutic strategies to treat AF that target an individual's metabolic profile. AF itself can induce changes in glucose, lipid and ketone metabolism, mitochondrial function and myofibrillar energetics (as part of a process referred to as 'metabolic remodelling'), which can all contribute to atrial dysfunction. In this Review, we discuss our current understanding of AF in the setting of metabolic disorders, as well as changes in atrial metabolism that are relevant to the development of AF. We also describe the potential of available and emerging treatment strategies to target metabolic remodelling in the setting of AF and highlight key questions and challenges that need to be addressed to improve outcomes in these patients.

Role of advanced glycation end-products in age-associated kidney dysfunction in naturally aging mice

AIMS

Advanced glycation end-products (AGEs) are implicated in the age-related decline of renal function, exacerbated by conditions, such as hyperglycemia and oxidative stress. The accumulation of AGEs in the kidneys contributes to the progressive decline in renal function observed with aging. However, the precise role and mechanisms of AGEs in the age-related decline of renal function remain unclear. In this study, we investigated the impact and potential mechanisms of AGEs on aging kidneys in naturally aging mice.

MATERIALS AND METHODS

Male C57BL/6 mice were divided into three groups: 6-, 57-, and 107-week-old. First, the 6- and 107-week-old mice were euthanized. The remaining mice were divided into young (6 weeks) and old (57 weeks) groups. The 57-week-old mice were orally administered aminoguanidine (100 mg/kg/day), an AGEs inhibitor, or vehicle for 13 weeks, resulting in a final age of 70 weeks. The serum and kidney tissues were collected for biochemical measurement, histological examination, immunohistochemistry staining, and immunoblotting analysis.

KEY FINDINGS

Our findings revealed a notable accumulation of AGEs in both serum and kidney tissue specimens and renal dysfunction in naturally aging mice. Aminoguanidine not only reversed AGEs accumulation but also ameliorated renal dysfunction. Additionally, aminoguanidine attenuated the upregulation of fibrosis markers (phosphorylated p38/α-SMA and C/EBP homologous protein, CHOP), senescence markers (p53 and p21), and oxidative stress marker (4-HNE) in the aging kidneys.

SIGNIFICANCE

These findings underscore the critical role of AGEs in age-related renal dysfunction and highlight the therapeutic potential of aminoguanidine in mitigating fibrosis and senescence, offering prospective avenues for combating age-associated renal ailments.

DJ-1: Potential target for treatment of myocardial ischemia-reperfusion injury

Ischemic heart disease (IHD) is a significant global health concern, resulting in high rates of mortality and disability among patients. Although coronary blood flow reperfusion is a key treatment for IHD, it often leads to acute myocardial ischemia-reperfusion injury (IRI). Current intervention strategies have limitations in providing adequate protection for the ischemic myocardium. DJ-1, originally known as a Parkinson's disease related protein, is a highly conserved cytoprotective protein. It is involved in enhancing mitochondrial function, scavenging reactive oxygen species (ROS), regulating autophagy, inhibiting apoptosis, modulating anaerobic metabolism, and exerting anti-inflammatory effects. DJ-1 is also required for protective strategies, such as ischemic preconditioning, ischemic postconditioning, remote ischemic preconditioning and pharmacological conditioning. Therefore, DJ-1 emerges as a potential target for the treatment of myocardial IRI. Our comprehensive review delves into its protective mechanisms in myocardial IRI and the structural foundations underlying its functions.

Adipose-derived stem cells apoptosis rejuvenate radiation-impaired skin in mice via remodeling and rearranging dermal collagens matrix

BACKGROUND

Chronic radiation dermatitis (CRD) is a late consequence of radiation with high incidence in patients receiving radiotherapy. Conventional therapies often yield unsatisfactory results. Therefore, this study aimed to explore the therapeutic potential and mechanism of adipose-derived stem cells (ADSCs) for CRD, paving the way for novel regenerative therapies in clinical practice.

METHODS

Clinical CRD skin biopsies were analyzed to character the pathological changes of CRD skin and guided the animal modeling scheme. Subsequently, an in vivo analysisusing mouse CRD models was conducted to explore their effects of ADSCs on CRD, monitoring therapeutic impact for up to 8 weeks. Transcriptome sequencing and histologic sections analysis were performed to explore the potential therapeutic mechanism of ADSCs. Following observing extensive apoptosis of transplanted ADSCs, the therapeutic effect of ADSCs were compared with those of apoptosis-inhibited ADSCs. Multiphoton imaging and analysis of collagen morphologic features were employed to explain how translated ADSCs promote collagen remodeling at the microscopic level based on the contrast of morphology of collagen fibers.

RESULTS

Following injection into CRD-afflicted skin, ADSCs therapy effectively mitigated symptoms of CRD, including acanthosis of the epidermis, fibrosis, and irregular collagen deposition, consistent with the possible therapeutic mechanism suggested by transcriptome sequencing. Notably, in vivo tracking revealed a significant reduction in ADSCs number due to extensive apoptosis. Inhibiting apoptosis in ADSCs partially tempered their therapeutic effects. Mechanically, analysis of collagen morphologic features indicated that translated ADSCs might promote dermal extracellular matrix remodeling through enlarging, lengthening, crimping, and evening collagen, counteracting the atrophy and rupture caused by irradiation.

CONCLUSIONS

This study demonstrated that ADSCs underwent substantial apoptosis upon local skin transplantation, and paradoxically, this apoptosis is essential for their efficacy in promoting the regeneration of late radiation-impaired skin. Mechanically, transplanted ADSCs could promote the remodeling and rearrangement of radiation-damaged dermal collagen matrix.

The role of nonmyocardial cells in the development of diabetic cardiomyopathy and the protective effects of FGF21: a current understanding

Diabetic cardiomyopathy (DCM) represents a unique myocardial disease originating from diabetic metabolic disturbances that is characterized by myocardial fibrosis and diastolic dysfunction. While recent research regarding the pathogenesis and treatment of DCM has focused primarily on myocardial cells, nonmyocardial cells-including fibroblasts, vascular smooth muscle cells (VSMCs), endothelial cells (ECs), and immune cells-also contribute significantly to the pathogenesis of DCM. Among various therapeutic targets, fibroblast growth factor 21 (FGF21) has been identified as a promising agent because of its cardioprotective effects that extend to nonmyocardial cells. In this review, we aim to elucidate the role of nonmyocardial cells in DCM and underscore the potential of FGF21 as a therapeutic strategy for these cells.

Aldehydes alter TGF-β signaling and induce obesity and cancer

Obesity and fatty liver diseases-metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH)-affect over one-third of the global population and are exacerbated in individuals with reduced functional aldehyde dehydrogenase 2 (ALDH2), observed in approximately 560 million people. Current treatment to prevent disease progression to cancer remains inadequate, requiring innovative approaches. We observe that Aldh2-/- and Aldh2-/-Sptbn1+/- mice develop phenotypes of human metabolic syndrome (MetS) and MASH with accumulation of endogenous aldehydes such as 4-hydroxynonenal (4-HNE). Mechanistic studies demonstrate aberrant transforming growth factor β (TGF-β) signaling through 4-HNE modification of the SMAD3 adaptor SPTBN1 (β2-spectrin) to pro-fibrotic and pro-oncogenic phenotypes, which is restored to normal SMAD3 signaling by targeting SPTBN1 with small interfering RNA (siRNA). Significantly, therapeutic inhibition of SPTBN1 blocks MASH and fibrosis in a human model and, additionally, improves glucose handling in Aldh2-/- and Aldh2-/-Sptbn1+/- mice. This study identifies SPTBN1 as a critical regulator of the functional phenotype of toxic aldehyde-induced MASH and a potential therapeutic target.

Clinical Evaluation of AMNIODERM+® Wound Dressing Containing Non-Viable Human Amniotic Membrane: Retrospective-Perspective Clinical Trial

Chronic wounds result from the body's inability to heal, causing pain, pathogen entry, limited treatment options, and societal burden. Diabetic foot ulcers are particularly challenging, often leading to severe complications like leg amputation. A clinical study tested AMNIODERM+®, a new device with a lyophilized human amniotic membrane (HAM), on chronic diabetic foot ulcers. Participants had diabetic neuropathic or neuroischemic leg wounds (2-16 cm2) unhealed by 20% after six weeks of standard care. This study showed significant wound healing improvements with AMNIODERM+®. The median wound size reduction after 12 weeks was 95.5%, far exceeding the null hypothesis of 20% change. Additionally, 65% of patients achieved complete ulceration healing, surpassing the 50% efficacy requirement. The median time to full closure was 11.4 weeks, with the proportion of completely healed patients rising progressively, reaching 55% by week 11. These findings, from the clinical trial "Freeze-dried amniotic membrane in the treatment of nonhealing wounds", suggest AMNIODERM+® as a promising future treatment for chronic diabetic foot ulcers. The published results were obtained as part of a clinical trial entitled "Freeze-dried amniotic membrane in the treatment of nonhealing wounds: a single-arm, retrospectively-perspective clinical trial", EUDAMED Nr. CIV-SK-22-10-041146.

Role of Receptor for Advanced Glycation End-Products in Endometrial Cancer: A Review

Endometrial cancer (EC) is the most common gynecological malignancy. EC is associated with metabolic disorders that may promote non-enzymatic glycation and activate the receptor for advanced glycation end-products (RAGE) signaling pathways. Thus, we assumed that RAGE and its ligands may contribute to EC. Of particular interest is the interaction between diaphanous-related formin 1 (Diaph1) and RAGE during the progression of human cancers. Diaph1 is engaged in the proper organization of actin cytoskeletal dynamics, which is crucial in cancer invasion, metastasis, angiogenesis, and axonogenesis. However, the detailed molecular role of RAGE in EC remains uncertain. In this review, we discuss epigenetic factors that may play a key role in the RAGE-dependent endometrial pathology. We propose that DNA methylation may regulate the activity of the RAGE pathway in the uterus. The accumulation of negative external factors, such as hyperglycemia, inflammation, and oxidative stress, may interfere with the DNA methylation process. Therefore, further research should take into account the role of epigenetic mechanisms in EC progression.

Glucose-Dependent Insulinotropic Polypeptide Inhibits AGE-Induced NADPH Oxidase-Derived Oxidative Stress Generation and Foam Cell Formation in Macrophages Partly via AMPK Activation

Glucose-dependent insulinotropic polypeptide (GIP) of the incretin group has been shown to exert pleiotropic actions. There is growing evidence that advanced glycation end products (AGEs), senescent macromolecules formed at an accelerated rate under chronic hyperglycemic conditions, play a role in the pathogenesis of atherosclerotic cardiovascular disease in diabetes. However, whether and how GIP could inhibit the AGE-induced foam cell formation of macrophages, an initial step of atherosclerosis remains to be elucidated. In this study, we address these issues. We found that AGEs increased oxidized low-density-lipoprotein uptake into reactive oxygen species (ROS) generation and Cdk5 and CD36 gene expressions in human U937 macrophages, all of which were significantly blocked by [D-Ala2]GIP(1-42) or an inhibitor of NADPH oxidase activity. An inhibitor of AMP-activated protein kinase (AMPK) attenuated all of the beneficial effects of [D-Ala2]GIP(1-42) on AGE-exposed U937 macrophages, whereas an activator of AMPK mimicked the effects of [D-Ala2]GIP(1-42) on foam cell formation, ROS generation, and Cdk5 and CD36 gene expressions in macrophages. The present study suggests that [D-Ala2]GIP(1-42) could inhibit the AGE-RAGE-induced, NADPH oxidase-derived oxidative stress generation in U937 macrophages via AMPK activation and subsequently suppress macrophage foam cell formation by reducing the Cdk5-CD36 pathway.

The role of SLC7A11 in diabetic wound healing: novel insights and new therapeutic strategies

Diabetic wounds are a severe complication of diabetes, characterized by persistent, non-healing ulcers due to disrupted wound-healing mechanisms in a hyperglycemic environment. Key factors in the pathogenesis of these chronic wounds include unresolved inflammation and antioxidant defense imbalances. The cystine/glutamate antiporter SLC7A11 (xCT) is crucial for cystine import, glutathione production, and antioxidant protection, positioning it as a vital regulator of diabetic wound healing. Recent studies underscore the role of SLC7A11 in modulating immune responses and oxidative stress in diabetic wounds. Moreover, SLC7A11 influences critical processes such as insulin secretion and the mTOR signaling pathway, both of which are implicated in delayed wound healing. This review explores the mechanisms regulating SLC7A11 and its impact on immune response, antioxidant defenses, insulin secretion, and mTOR pathways in diabetic wounds. Additionally, we highlight the current advancements in targeting SLC7A11 for treating related diseases and conceptualize its potential applications and value in diabetic wound treatment strategies, along with the challenges encountered in this context.

Dietary glycation compounds - implications for human health

The term "glycation compounds" comprises a wide range of structurally diverse compounds that are formed endogenously and in food via the Maillard reaction, a chemical reaction between reducing sugars and amino acids. Glycation compounds produced endogenously are considered to contribute to a range of diseases. This has led to the hypothesis that glycation compounds present in food may also cause adverse effects and thus pose a nutritional risk to human health. In this work, the Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG) summarized data on formation, occurrence, exposure and toxicity of glycation compounds (Part A) and systematically assessed potential associations between dietary intake of defined glycation compounds and disease, including allergy, diabetes, cardiovascular and renal disease, gut/gastrotoxicity, brain/cognitive impairment and cancer (Part B). A systematic search in Pubmed (Medline), Scopus and Web of Science using a combination of keywords defining individual glycation compounds and relevant disease patterns linked to the subject area of food, nutrition and diet retrieved 253 original publications relevant to the research question. Of these, only 192 were found to comply with previously defined quality criteria and were thus considered suitable to assess potential health risks of dietary glycation compounds. For each adverse health effect considered in this assessment, however, only limited numbers of human, animal and in vitro studies were identified. While studies in humans were often limited due to small cohort size, short study duration, and confounders, experimental studies in animals that allow for controlled exposure to individual glycation compounds provided some evidence for impaired glucose tolerance, insulin resistance, cardiovascular effects and renal injury in response to oral exposure to dicarbonyl compounds, albeit at dose levels by far exceeding estimated human exposures. The overall database was generally inconsistent or inconclusive. Based on this systematic review, the SKLM concludes that there is at present no convincing evidence for a causal association between dietary intake of glycation compounds and adverse health effects.

Terpenes in the management of chronic kidney disease

Chronic kidney disease (CKD) is a chronic and progressive systemic condition that characterizes irreversible alterations in the kidneys' function and structure over an extended period, spanning months to years. CKD is the one of the major causes of mortality worldwide. However, very limited treatment options are available in the market for management of the CKD. Diabetes and hypertension are the key risk factors for the progression of CKD. It is majorly characterised by glomerulosclerosis, tubular atrophy, and interstitial fibrosis. Plants are considered safe and effective in treating various chronic conditions. A diverse group of phytoconstituents, including polyphenols, flavonoids, alkaloids, tannins, saponins, and terpenes, have found significant benefits in managing chronic ailments. Terpenes constitute a diverse group of plant compounds with various therapeutic benefits. Evidence-based pharmacological studies underscore the crucial role played by terpenes in preventing and managing CKD. These substances demonstrate the capacity to hinder detrimental pathways, such as oxidative stress, inflammation and fibrosis, thereby demonstrating benefit in renal dysfunction. This review offers a comprehensive overview of the roles and positive attributes of commonly occurring terpenes in managing the causes and risk factors of CKD and the associated conditions.

Diabetes is not a negative prognostic factor for 30-days mortality after surgery for acute type A aortic dissection

Background

The correlation between diabetes and aortic dissection is not fully understood yet, although in literature many studies have suggested that there may be an association between the two conditions. The purpose of this study is to evaluate whether diabetes represents a short- and long-term risk factor for mortality from type A acute aortic dissection.

Materials and methods

A total of 340 patients with the diagnosis of type A acute aortic dissection underwent aortic surgery between January 2002 and March 2023. The sample was divided into 2 cohorts according to the presence of diabetes (n = 34) or not (n = 306).

Results

The mean age was 66 (±12.4) years and 60.9% were male. The primary endpoint was 30-day mortality. Hospital mortality was 12 (35.3%) for the diabetes group and 70 (22.9%) for nondiabetes group (P = 0.098). Overall survival at 10 years was 48.3% [95% confidence interval (CI): 41.6-54.7%], while the 10-year survival for people with diabetes was 29.5% (95% CI: 13.2-47.9%) and for nondiabetes group 50.6% (95% CI: 43.4-57.3%) (Log-rank, P = 0.024).

Conclusion

Diabetes was not found to be a risk factor associated with 30-day mortality in patients undergoing surgery for type A acute aortic dissection. It was a risk factor for long-term survival, but this may be related to diabetes complications.

Reciprocal effect on lateral diffusion of receptor for advanced glycation endproducts and toll-like receptor 4 in the HEK293 cell membrane

Receptor for advanced glycation endproducts (RAGE) and toll-like receptor 4 (TLR4) are pattern-recognition receptors that bind to molecular patterns associated with pathogens, stress, and cellular damage. Diffusion plays an important role in receptor functionality in the cell membrane. However, there has been no prior investigation of the reciprocal effect of RAGE and TLR4 diffusion properties in the presence and absence of each receptor. This study reports how RAGE and TLR4 affect the mobility of each other in the human embryonic kidney (HEK) 293 cell membrane. Diffusion properties were measured using single-particle tracking (SPT) with quantum dots (QDs) that are selectively attached to RAGE or TLR4. The Brownian diffusion coefficients of RAGE and TLR4 are affected by the presence of the other receptor, leading to similar diffusion coefficients when both receptors coexist in the cell. When TLR4 is present, the average Brownian diffusion coefficient of RAGE increases by 40%, while the presence of RAGE decreases the average Brownian diffusion coefficient of TLR4 by 32%. Diffusion in confined membrane domains is not altered by the presence of the other receptor. The mobility of the cell membrane lipid remains constant whether one or both receptors are present. Overall, this work shows that the presence of each receptor can affect a subset of diffusion properties of the other receptor without affecting the mobility of the membrane.

Skin autofluorescence, a measure for accumulation of advanced glycation end products, positively associates with blood neutrophil and monocyte counts in the general population, and particularly in men with prediabetes

BACKGROUND AND AIMS

Previous studies have shown that skin autofluorescence (SAF), measured with an advanced glycation end product (AGE) reader, estimates the accumulation of AGEs in tissues. SAF is predictive of incident type 2 diabetes, cardiovascular disease (CVD), and CV mortality in the general population. Studies in diabetic mice have shown that activation of the receptor for AGEs in hematopoietic progenitor cells increases blood neutrophils and monocytes, impairing atherosclerosis regression. We asked whether SAF is associated with blood neutrophil and monocyte counts in the general population, and whether this was moderated by prediabetes, diabetes, and sex.

METHODS

We examined the associations between SAF and blood neutrophil/monocyte counts in participants of the Lifelines cohort (n = 58,923: n = 24,382 men, and n = 34,541 women), a prospective population-based cohort from the North of the Netherlands, employing multivariable regression analyses.

RESULTS

SAF positively associated with blood neutrophil and monocyte counts in the whole cohort. The positive association between SAF and monocyte, but not neutrophil, counts was moderated by prediabetes and diabetes. Positive associations between SAF and blood neutrophil and monocyte counts were moderated by male sex. Moreover, three-way interaction analyses revealed that the positive associations between SAF and neutrophil and monocyte counts were moderated by prediabetes, but not diabetes, in male sex.

CONCLUSIONS

SAF is positively associated with blood neutrophil and monocyte counts in the general population, especially in men with prediabetes. This may contribute to the increased CV risk in men with prediabetes.

Endothelial dysfunction: molecular mechanisms and clinical implications

Cardiovascular disease (CVD) and its complications are a leading cause of death worldwide. Endothelial dysfunction plays a crucial role in the initiation and progression of CVD, serving as a pivotal factor in the pathogenesis of cardiovascular, metabolic, and other related diseases. The regulation of endothelial dysfunction is influenced by various risk factors and intricate signaling pathways, which vary depending on the specific disease context. Despite numerous research efforts aimed at elucidating the mechanisms underlying endothelial dysfunction, the precise molecular pathways involved remain incompletely understood. This review elucidates recent research findings on the pathophysiological mechanisms involved in endothelial dysfunction, including nitric oxide availability, oxidative stress, and inflammation-mediated pathways. We also discuss the impact of endothelial dysfunction on various pathological conditions, including atherosclerosis, heart failure, diabetes, hypertension, chronic kidney disease, and neurodegenerative diseases. Furthermore, we summarize the traditional and novel potential biomarkers of endothelial dysfunction as well as pharmacological and nonpharmacological therapeutic strategies for endothelial protection and treatment for CVD and related complications. Consequently, this review is to improve understanding of emerging biomarkers and therapeutic approaches aimed at reducing the risk of developing CVD and associated complications, as well as mitigating endothelial dysfunction.

New Glycotoxin Inhibitor from Sesuvium sesuvioides Mitigates Symptoms of Insulin Resistance and Diabetes by Suppressing AGE-RAGE Axis in Skeletal Muscle

The current study intended to investigate the role of new natural compounds derived from the Sesuvium sesuvioides plant in mitigating symptoms of diabetes and insulin resistance in the diabetic mice model. Anti-advanced glycation activity, insulin, and adiponectin were quantified by enzyme-linked immunosorbent assay (ELISA). Glucose uptake was performed using enzymatic fluorescence assay, and glycogen synthesis was measured using PAS staining. Gene and protein expression was assessed using real time PCR (RT-PCR), and immunoblotting and fluorescent microscopy, respectively. The new flavonoid glycoside eupalitin 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside 1 isolated from S. sesuvioides exhibited anti-AGE activity by reducing human glycated albumin in liver cells. In a diabetic mouse model treated with compound 1, we observed improved glucose tolerance, increased adiponectin levels, and decreased insulin resistance. We also observed alleviated AGEs induced reduction in glucose uptake and restored glycogen synthesis in the compound 1-treated diabetic mice muscles. Exploring the molecular mechanism of action in skeletal muscle tissue of diabetic mice, we found that 1 reduced AGE-induced reactive oxygen species and the inflammatory gene in the muscle of diabetic mice. Additionally, 1 exhibited these effects by reducing the gene and protein expression of receptor for advanced glycation end products (RAGE) and inhibiting protein kinase C (PKC) delta activation. This further led us to demonstrate that compound 1 reduced serine phosphorylation of IRS-1, thereby restoring insulin sensitivity. We conclude that a new flavonoid glycoside from S. sesuvioides could be a therapeutic target for the treatment of symptoms of insulin resistance and diabetes.

Receptor for advanced glycation end products polymorphisms in coronary artery ectasia

BACKGROUND

Although the implication of receptor of advanced glycation endproducts (RAGE) has been reported in coronary artery disease, its roles in coronary artery ectasia (CAE) have remained undetermined. Furthermore, the effect of RAGE polymorfisms were not well-defined in scope of soluble RAGE (sRAGE) levels. Thus, we aimed to investigate the influence of the functional polymorphisms of RAGE -374T > A (rs1800624) and G82S (rs2070600) in CAE development.

METHODS

This prospective observational study was conducted in 2 groups selected of 2452 patients who underwent elective coronary angiography (CAG) for evaluation after positive noninvasive heart tests. Group-I included 98 patients with non-obstructive coronary artery disease and CAE, and Group-II (control) included 100 patients with normal coronary arteries. SNPs were genotyped by real-time PCR using Taqman® genotyping assay. Serum sRAGE and soluble lectin-like oxidized receptor-1 (sOLR1) were assayed by ELISA and serum lipids were measured enzymatically.

RESULTS

The frequencies of the RAGE -374A allele and -374AA genotype were significantly higher in CAE patients compared to controls (p < 0.001). sRAGE levels were not different between study groups, while sOLR1 levels were elevated in CAE (p = 0.004). In controls without systemic disease, -374A allele was associated with low sRAGE levels (p < 0.05), but this association was not significant in controls with HT. Similarly, sRAGE levels of CAE patients with both HT and T2DM were higher than those no systemic disease (p = 0.02). The -374A allele was also associated with younger patient age and higher platelet count in the CAE group in both total and subgroup analyses. In the correlation analyses, the -374A allele was also negatively correlated with age and positively correlated with Plt in all of these CAE groups. In the total CAE group, sRAGE levels also showed a positive correlation with age and a negative correlation with HDL-cholesterol levels. On the other hand, a negative correlation was observed between sRAGE and Plt in the total, hypertensive and no systemic disease control subgroups. Multivariate logistic regression analysis confirmed that the -374A allele (p < 0.001), hyperlipidemia (p < 0.05), and high sOLR1 level (p < 0.05) are risk factors for CAE. ROC curve analysis shows that RAGE -374A allele has AUC of 0.713 (sensitivity: 83.7 %, specificity: 59.0 %), which is higher than HLD (sensitivity: 59.2 %, specificity: 69.0 %), HT (sensitivity: 62.4 %, specificity: 61.1 %) and high sOLR1 level (≥0.67 ng/ml)) (sensitivity: 59.8 %, specificity: 58.5 %).

CONCLUSION

Beside the demonstration of the relationship between -374A allele and increased risk of CAE for the first time, our results indicate that antihypertensive and antidiabetic treatment in CAE patients causes an increase in sRAGE levels. The lack of an association between the expected -374A allele and low sRAGE levels in total CAE group was attributed to the high proportion of hypertensive patients and hence to antihypertensive treatment. Moreover, the RAGE -374A allele is associated with younger age at CAE and higher Plt, suggesting that -374A may also be associated with platelet activation, which plays a role in the pathogenesis of CAE. However, our data need to be confirmed in a large study for definitive conclusions.

Lindera obtusiloba Blume Alleviates Non-Alcoholic Fatty Liver Disease Promoted by Nε-(carboxymethyl)lysine

Non-alcoholic fatty liver disease (NAFLD) is a major issue because it is closely associated with metabolic diseases. Advanced glycation end products (AGEs) are implicated as risk factors for steatosis during NAFLD progression. AGEs influence NAFLD progression through a receptor-independent pathway involving AGE cross-link formation and a receptor-dependent pathway that binds to receptors like receptors for advanced glycation end products (RAGE). The objectives of this study are to examine the effect of Lindera obtusiloba Blume (LO) on NAFLD promoted by Nε-(carboxymethyl)lysine (CML), one of the most common dietary AGEs. The anti-glycation effects of LO were evaluated by inhibiting the AGEs formation and AGEs-collagen cross-links breaking. The efficacy of LO against NAFLD promoted by CML was assessed using both in vitro and in vivo models. NAFLD was induced in mice by feeding a high-fat diet and orally administering CML over a period of 12 weeks, and the effects of LO on lipid metabolism and its regulatory mechanisms were investigated. LO showed the effect of inhibited AGEs formation and breakage, and collagen cross-linking. Fed a high-fat diet with administered CML by gavage, LO administration resulted in a reduction in body weight, fat mass, serum triglycerides, total cholesterol, and low-density lipoprotein cholesterol levels. LO reduced hepatic CML accumulation and RAGE expression in mice fed a high-fat diet and orally administered CML. LO alleviated hepatic steatosis accompanied by lipid accumulation and histological damage by suppressing the expression of sterol regulatory element-binding protein 1c, carbohydrate response element binding protein, fatty acid synthase, stearoyl-CoA desaturase1, tumor necrosis factor-α, and interleukin-1β. LO alleviated the MAPK/NF-κB expression by attenuating CML and RAGE expression. Taken together, our results demonstrate that LO alleviates the progression of NAFLD by lowering the levels of AGEs by downregulating CML/RAGE expression.

Diabetes and Heart Failure: A Literature Review, Reflection and Outlook

Heart failure (HF) is a complex clinical syndrome caused by structural or functional dysfunction of the ventricular filling or blood supply. Diabetes mellitus (DM) is an independent predictor of mortality for HF. The increase in prevalence, co-morbidity and hospitalization rates of both DM and HF has further fueled the possibility of overlapping disease pathology between the two. For decades, antidiabetic drugs that are known to definitively increase the risk of HF are the thiazolidinediones (TZDs) and saxagliptin in the dipeptidyl peptidase-4 (DPP-4) inhibitor, and insulin, which causes sodium and water retention, and whether metformin is effective or safe for HF is not clear. Notably, sodium-glucose transporter 2 (SGLT2) inhibitors and partial glucagon-like peptide-1 receptor agonists (GLP-1 RA) all achieved positive results for HF endpoints, with SGLT2 inhibitors in particular significantly reducing the composite endpoint of cardiovascular mortality and hospitalization for heart failure (HHF). Further understanding of the mutual pathophysiological mechanisms between HF and DM may facilitate the detection of novel therapeutic targets to improve the clinical outcome. This review focuses on the association between HF and DM, emphasizing the efficacy and safety of antidiabetic drugs and HF treatment. In addition, recent therapeutic advances in HF and the important mechanisms by which SGLT2 inhibitors/mineralocorticoid receptor antagonist (MRA)/vericiguat contribute to the benefits of HF are summarized.

Association between glycated albumin and sudden death in patients undergoing hemodialysis

BACKGROUND

The frequency of sudden death and its risk factors in patients undergoing hemodialysis are unknown. This study was performed to examine the association between glycated albumin (GA) and sudden death in Japanese patients undergoing hemodialysis.

METHODS

In total, 260 patients undergoing hemodialysis aged ≥18 years were retrospectively followed for a mean of 4.6 years. The patients' serum GA levels were divided into tertiles, and the patients' sex, age, albumin level, C-reactive protein (CRP) level, and cardiothoracic ratio (CTR) were selected as adjustment factors. A logistic regression model was used to calculate the odds ratio (OR) for the occurrence of sudden death by GA level.

RESULTS

Ninety-one patients died during follow-up. Of the 91 deaths, 23 (25.2%) were defined as sudden deaths. Compared with non-sudden death cases, sudden death cases were significantly younger (p = 0.002) and had a higher proportion of men (p = 0.03), a higher proportion of diabetes (p = 0.008), and higher GA levels (p = 0.023). Compared with patients with the lowest GA levels (<15.2%), those with the highest GA levels (≥18.5%) had a sex- and age-adjusted OR for sudden death of 5.40 [95% confidence interval (CI): 1.35-21.85]. After adjusting for the albumin level, CRP level, and CTR in addition to sex and age, the OR for sudden death of patients with the highest GA levels increased to 6.80 (95%CI: 1.64-28.08); the relationship did not change.

CONCLUSION

Serum GA levels were significantly associated with sudden death in patients undergoing hemodialysis.

Glucoselysine, a unique advanced glycation end-product of the polyol pathway and its association with vascular complications in type 2 diabetes

Glucoselysine (GL) is an unique advanced glycation end-product derived from fructose. The main source of fructose in vivo is the polyol pathway, and an increase in its activity leads to diabetic complications. Here, we aimed to demonstrate that GL can serve as an indicator of the polyol pathway activity. Additionally, we propose a novel approach for detecting GL in peripheral blood samples using liquid chromatography-tandem mass spectrometry and evaluate its clinical usefulness. We successfully circumvent interference from fructoselysine, which shares the same molecular weight as GL, by performing ultrafiltration and hydrolysis without reduction, successfully generating adequate peaks for quantification in serum. Furthermore, using immortalized aldose reductase KO mouse Schwann cells, we demonstrate that GL reflects the downstream activity of the polyol pathway and that GL produced intracellularly is released into the extracellular space. Clinical studies reveal that GL levels in patients with type 2 diabetes are significantly higher than those in healthy participants, while Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)ornithine (MG-H1) levels are significantly lower. Both GL and MG-H1 show higher values among patients with vascular complications; however, GL varies more markedly than MG-H1 as well as hemoglobin A1c, fasting plasma glucose, and estimated glomerular filtration rate. Furthermore, GL remains consistently stable under various existing drug treatments for type 2 diabetes, whereas MG-H1 is impacted. To the best of our knowledge, we provide important insights in predicting diabetic complications caused by enhanced polyol pathway activity via assessment of GL levels in peripheral blood samples from patients.

Delivery technologies for therapeutic targeting of fibronectin in autoimmunity and fibrosis applications

Fibronectin (FN) is a critical component of the extracellular matrix (ECM) contributing to various physiological processes, including tissue repair and immune response regulation. FN regulates various cellular functions such as adhesion, proliferation, migration, differentiation, and cytokine release. Alterations in FN expression, deposition, and molecular structure can profoundly impact its interaction with other ECM proteins, growth factors, cells, and associated signaling pathways, thus influencing the progress of diseases such as fibrosis and autoimmune disorders. Therefore, developing therapeutics that directly target FN or its interaction with cells and other ECM components can be an intriguing approach to address autoimmune and fibrosis pathogenesis.

Microvascular burden and long-term risk of stroke and dementia in type 2 diabetes mellitus

OBJECTIVE

To examine the associations between microvascular disease (MVD) and risk of stroke, dementia, and their major subtypes among individuals with type 2 diabetes mellitus (T2DM).

METHODS

We included 26,173 participants with T2DM from the UK Biobank who had no known stroke or dementia at baseline. MVD burden was reflected by the presence of retinopathy, peripheral neuropathy, and chronic kidney disease. Cox regression models were used to estimate hazard ratios (HRs) and 95 % confidential intervals (CIs) of stroke and dementia associated with overall MVD burden and individual MVD.

RESULTS

During a median follow-up of 11.5 years, 1103 incident stroke (964 ischemic and 269 hemorrhagic stroke) and 813 incident dementia (312 Alzheimer's disease and 304 vascular dementia) cases were identified. The risk of stroke, dementia, and their major subtypes all increased with an increasing number of MVD (all P-trend <0.001). The adjusted HRs (95 % CIs) comparing three with no MVD were 5.03 (3.16, 8.02) for all stroke, 4.57 (2.75, 7.59) for ischemic stroke, and 6.60 (2.65, 16.43) for hemorrhagic stroke. The corresponding estimates were 4.28 (2.33, 7.86) for all-cause dementia, 6.96 (3.02, 16.01) for Alzheimer's disease, and 3.81 (1.40, 10.42) for vascular dementia. Among the three MVD, chronic kidney disease showed the strongest associations with both stroke subtypes, while peripheral neuropathy was most strongly associated with both dementia subtypes.

CONCLUSIONS

Risk of stroke, dementia, and their major subtypes increased with an increasing number of MVD. The associations of individual MVD with stroke and dementia varied substantially by types of MVD.

Melatonin at repeated doses alleviates hyperglycemia-exacerbated cerebral ischemia-reperfusion injury at 72 h via anti-inflammation and anti-apoptosis

Objective

We aimed to investigate how hyperglycemia would exacerbate cerebral ischemia-reperfusion injury (CIRI) in a rat model of type 1 diabetes mellitus (T1DM) and explore the beneficial effects of multiple doses of melatonin in T1DM induced CIRI.

Method

The T1DM rat model was induced with streptozocin, and melatonin (10 mg/kg) was injected at 0.5 h before ischemia as well as at 24 and 48 h after reperfusion.

Results

When compared to normoglycemic (NG) rats, T1DM rats had hyperglycemia with weight loss before CIRI. Despite comparable degrees of ischemia and initial reperfusion, T1DM rats tended to have greater weight loss and had worse neurological deficits and larger infarct volume than NG rats up to 72 h after CIRI. Persistent activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway but not of apoptosis or calpains was a crucial factor in T1DM-mediated exacerbation of CIRI at 72 h. Despite lacking effects on baseline hyperglycemia, ischemia and initial reperfusion, melatonin at multiple doses lessened post-CIRI weight loss, neurological deficits and infarct volume in T1DM rats at 72 h. when compared to vehicle-treated T1DM rats with CIRI. Beneficial effects of melatonin treatment included decreased activation of NF-κB pathway, apoptosis and calpains, leading to reduced expression of inducible nitric oxide synthase and enhanced neuronal density.

Conclusion

Melatonin at multiple doses can alleviate T1DM-mediated exacerbation of CIRI at 72 h through anti-inflammation and anti-apoptosis.

Effects of protein glycation and protective mechanisms against glycative stress

Glycation is a posttranslational modification of proteins that contributes to the vast array of biological information that can be conveyed via a singular proteome. Understanding the role of advanced glycation end-products (AGEs) in human health and pathophysiology can be difficult, as the physiological effects of AGEs have been associated with multiple biological processes and disease state development, including acute myocardial ischemia-reperfusion injury, heart failure, and atherosclerosis, as well as tumor cell migration. The critical role of the glyoxalase system in the detoxification of methylglyoxal and other AGEs has been well established. Recently, evidence has emerged that DJ-1 displays antiglycative activity and may contribute to another mechanism of protection against protein glycation outside of the glyoxalase system. Identification of potential substrates of DJ-1 and determination of the pathways in which DJ-1 operates, is needed to fully understand the role of this protein in modulating biological homeostasis and the development of disease.

Proteomic analysis of diabetic retinopathy identifies potential plasma-protein biomarkers for diagnosis and prognosis

OBJECTIVES

To identify molecular pathways and prognostic- and diagnostic plasma-protein biomarkers for diabetic retinopathy at various stages.

METHODS

This exploratory, cross-sectional proteomics study involved plasma from 68 adults, including 15 healthy controls and 53 diabetes patients for various stages of diabetic retinopathy: non-diabetic retinopathy, non-proliferative diabetic retinopathy, proliferative diabetic retinopathy and diabetic macular edema. Plasma was incubated with peptide library beads and eluted proteins were tryptic digested, analyzed by liquid chromatography-tandem mass-spectrometry followed by bioinformatics.

RESULTS

In the 68 samples, 248 of the 731 identified plasma-proteins were present in all samples. Analysis of variance showed differential expression of 58 proteins across the five disease subgroups. Protein-Protein Interaction network (STRING) showed enrichment of various pathways during the diabetic stages. In addition, stage-specific driver proteins were detected for early and advanced diabetic retinopathy. Hierarchical clustering showed distinct protein profiles according to disease severity and disease type.

CONCLUSIONS

Molecular pathways in the cholesterol metabolism, complement system, and coagulation cascade were enriched in patients at various stages of diabetic retinopathy. The peroxisome proliferator-activated receptor signaling pathway and systemic lupus erythematosus pathways were enriched in early diabetic retinopathy. Stage-specific proteins for early - and advanced diabetic retinopathy as determined herein could be 'key' players in driving disease development and potential 'target' proteins for future therapies. For type 1 and 2 diabetes mellitus, the proteomic profiles were especially distinct during the early disease stage. Validation studies should aim to clarify the role of the detected molecular pathways, potential biomarkers, and potential 'target' proteins for future therapies in diabetic retinopathy.

Longitudinal plasma proteomic analysis of 1117 hospitalized patients with COVID-19 identifies features associated with severity and outcomes

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is characterized by highly heterogeneous manifestations ranging from asymptomatic cases to death for still incompletely understood reasons. As part of the IMmunoPhenotyping Assessment in a COVID-19 Cohort study, we mapped the plasma proteomes of 1117 hospitalized patients with COVID-19 from 15 hospitals across the United States. Up to six samples were collected within ~28 days of hospitalization resulting in one of the largest COVID-19 plasma proteomics cohorts with 2934 samples. Using perchloric acid to deplete the most abundant plasma proteins allowed for detecting 2910 proteins. Our findings show that increased levels of neutrophil extracellular trap and heart damage markers are associated with fatal outcomes. Our analysis also identified prognostic biomarkers for worsening severity and death. Our comprehensive longitudinal plasma proteomics study, involving 1117 participants and 2934 samples, allowed for testing the generalizability of the findings of many previous COVID-19 plasma proteomics studies using much smaller cohorts.

Identification of Yellow Advanced Glycation End Products in Human Skin

Skin yellowness is a hallmark of dull or unhealthy skin, particularly among Asians. Previous research has indicated a link between skin glycation and skin yellowness. However, the specific glycated chemicals contributing to yellowish skin appearance have not been identified yet. Using HPLC-PDA-HRMS coupled with native and artificially glycated human epidermal explant skin, we identified intensely yellow colored glycated chromophores "(1R, 8aR) and (1S, 8aR)-4-(2-furyl)-7-[(2-furyl)-methylidene]-2-hydroxy-2H,7H,8AH-pyrano-[2,3-B]-pyran-3-one" (abbreviated as AGEY) from human skin samples for the first time. The abundance of AGEY was strongly correlated with skin yellowness in the multiple skin explant tissues. We further confirmed the presence of AGEY in cultured human keratinocytes and 3D reconstructed human epidermal (RHE) models. Additionally, we demonstrated that a combination of four cosmetic compounds with anti-glycation properties can inhibit the formation of AGEY and reduce yellowness in the RHE models. In conclusion, we have identified specific advanced glycation end products with an intense yellow color, namely AGEY, in human skin tissues for the first time. The series of study results highlighted the significant contribution of AGEY to the yellow appearance of the skin. Furthermore, we have identified a potential cosmetic solution to mitigate AGEY formation, leading to a reduction in yellowness in the in vitro RHE models.

Retinoid Synthesis Regulation by Retinal Cells in Health and Disease

Vision starts in retinal photoreceptors when specialized proteins (opsins) sense photons via their covalently bonded vitamin A derivative 11cis retinaldehyde (11cis-RAL). The reaction of non-enzymatic aldehydes with amino groups lacks specificity, and the reaction products may trigger cell damage. However, the reduced synthesis of 11cis-RAL results in photoreceptor demise and suggests the need for careful control over 11cis-RAL handling by retinal cells. This perspective focuses on retinoid(s) synthesis, their control in the adult retina, and their role during retina development. It also explores the potential importance of 9cis vitamin A derivatives in regulating retinoid synthesis and their impact on photoreceptor development and survival. Additionally, recent advancements suggesting the pivotal nature of retinoid synthesis regulation for cone cell viability are discussed.

Comprehensive characterization of protein modifications using mass spectrometry and dry blood spots

PURPOSE

The main objective of this study is to characterize and analyze modified peptides in DBS samples. This includes deciphering their specific PTMs and understanding their potential impact on the population or disease cohort under study.

EXPERIMENTAL DESIGN

Using mass spectrometry-based proteomic approaches, we performed a comprehensive analysis of DBS samples. Our focus was on the identification and quantification of modified peptides. We also took advantage of recent advances in DBS mass spectrometry to ensure accurate detection and quantification.

RESULTS

A comprehensive analysis identified 972 modified peptides in DBS samples. Of these, a subset of 211 peptides was consistently present in all samples, highlighting their potential biological importance and relevance. This indicates a diverse spectrum of PTMs in the proteome of DBS samples.

CONCLUSIONS AND CLINICAL RELEVANCE

Integration of mass spectrometry and proteomics has revealed a broad spectrum of modified peptides in DBS samples and highlighted their importance in biological processes and disease progression. Accurate detection of these PTMs may be critical for risk stratification and disease management. This study improves the understanding of molecular mechanisms underlying biological processes and disease development, providing important insights for clinical applications.

Chronic hyperglycemia and intracranial meningiomas

Meningiomas are among the most common primary tumors of the central nervous system. Previous research into the meningioma histological appearance, genetic markers, transcriptome and epigenetic landscape has revealed that benign meningiomas significantly differ in their glucose metabolism compared to aggressive lesions. However, a correlation between the systemic glucose metabolism and the metabolism of the tumor hasn't yet been found. We hypothesized that chronic levels of glycaemia (approximated with glycated hemoglobin (HbA1c)) are different in patients with aggressive and benign meningiomas. The study encompassed 71 patients with de novo intracranial meningiomas, operated on in three European hospitals, two in Croatia and one in Spain. Our results show that patients with WHO grade 2 meningiomas had significantly higher HbA1c values compared to patients with grade 1 lesions (P = 0.0290). We also found a significant number of patients (19/71; 26.7%) being hyperglycemic, harboring all the risks that such a condition entails. Finally, we found a significant correlation between our patients' age and their preoperative HbA1c levels (P = 0.0008, ρ(rho) = 0.388), suggesting that older meningioma patients are at a higher risk of having their glycaemia severely dysregulated. These findings are especially important considering the current routine and wide-spread use of corticosteroids as anti-edematous treatment. Further research in this area could lead to better understanding of meningiomas and have immediate clinical impact.

Khachatryan L, Mohammadian-Hafshejani A. Investigating the association between diabetes and carpal tunnel syndrome: A systematic review and meta-analysis approach

INTRODUCTION

In recent years, several studies have reported on the relationship between diabetes and carpal tunnel syndrome (CTS). However, due to their contradictory results, a systematic review and meta-analysis were conducted to investigate this subject.

METHODS

This study is a systematic review and meta-analysis of studies published in ISI Web of Science, Scopus, PubMed, Cochrane, Google Scholar, and Embase databases. Heterogeneity in the studies included in the meta-analysis was evaluated using statistical tests such as the Chi-square test, I2, and forest plots. Publication bias was assessed using Begg's and Egger's tests.

RESULTS

This investigation analyzed data from 42 studies conducted between 1985 and 2022, with a total of 3,377,816 participants. The meta-analysis demonstrated that the odds ratio (OR) of CTS in participants with a history of diabetes compared to those without was 1.90 (95% CI: 1.64-2.21; P-value < 0.001). Given that publication bias was observed in this study (Begg's test P-value = 0.01), the modified OR was calculated with consideration of missed studies, which was 1.68 (95% CI: 1.45-1.94; P-value < 0.001).

CONCLUSION

The results of this study suggest that diabetic patients have 90% higher odds of developing CTS compared to non-diabetic individuals, which is statistically significant.

Non-coronary peripheral arterial complications in people with type 2 diabetes: a Swedish retrospective cohort study

Background

Few studies have explored long-term trends and risk factors for peripheral arterial complications in type 2 diabetes compared to the general population. Our research focuses on identifying optimal risk factors, their significance, risk associated with multifactorial risk factor control, and trends for these complications in diabetic patients versus general controls.

Methods

This study included persons with type 2 diabetes mellitus entered into the Swedish National Diabetes Register 2001-2019 and controls matched for age-, sex- and county of residence. Outcomes comprised of extracranial large artery disease, aortic aneurysm, aortic dissection, lower extremity arterial disease and diabetes foot disease. Standardized incidence rates and Cox regression were used for analyses.

Findings

The study comprises 655,250 persons with type 2 diabetes mellitus; average age 64.2; 43.8% women. Among persons with type 2 diabetes mellitus, the incidence rates per 100,000 person years for each non-coronary peripheral arterial complication event changed between 2001 and 2019 as follows: extracranial large artery disease 170.0-84.9; aortic aneurysm 40.6-69.2; aortic dissection 9.3 to 5.6; lower extremity artery disease from 338.8 to 190.8; and diabetic foot disease from 309.8 to 226.8. Baseline hemoglobin A1c (HbA1c), systolic blood pressure (SBP), smoking status and lipid levels were independently associated with all outcomes in the type 2 diabetes mellitus cohort. Within the cohort with type 2 diabetes mellitus, the risk for extracranial large artery disease and lower extremity artery disease increased in a stepwise fashion for each risk factor not within target. Excess risk for non-coronary peripheral arterial complications in the entire cohort for persons with type 2 diabetes mellitus, compared to matched controls, were as follows: extracranial large artery disease adjusted hazard ratio (HR) 1.69 (95% confidence interval (CI), 1.65-1.73), aortic aneurysm HR 0.89 (95% CI, 0.87-0.92), aortic dissection HR 0.51 (95% CI, 0.46-0.57) and lower extremity artery disease HR 2.59 (95% CI, 2.55-2.64).

Interpretation

The incidence of non-coronary peripheral arterial complications has declined significantly among persons with type 2 diabetes mellitus, with the exception of aortic aneurysm. HbA1c, smoking and blood pressure demonstrated greatest relative contribution for outcomes and lower levels of cardiometabolic risk factors are associated with reduced relative risk of outcomes.

Funding

Swedish Governmental and the County support of research and education of doctors, the Swedish Heart-Lung Foundation and Åke-Wibergs grant.

The interplay of collagen, macrophages, and microcalcification in atherosclerotic plaque cap rupture mechanics

The rupture of an atherosclerotic plaque cap overlying a lipid pool and/or necrotic core can lead to thrombotic cardiovascular events. In essence, the rupture of the plaque cap is a mechanical event, which occurs when the local stress exceeds the local tissue strength. However, due to inter- and intra-cap heterogeneity, the resulting ultimate cap strength varies, causing proper assessment of the plaque at risk of rupture to be lacking. Important players involved in tissue strength include the load-bearing collagenous matrix, macrophages, as major promoters of extracellular matrix degradation, and microcalcifications, deposits that can exacerbate local stress, increasing tissue propensity for rupture. This review summarizes the role of these components individually in tissue mechanics, along with the interplay between them. We argue that to be able to improve risk assessment, a better understanding of the effect of these individual components, as well as their reciprocal relationships on cap mechanics, is required. Finally, we discuss potential future steps, including a holistic multidisciplinary approach, multifactorial 3D in vitro model systems, and advancements in imaging techniques. The obtained knowledge will ultimately serve as input to help diagnose, prevent, and treat atherosclerotic cap rupture.

Exercise in Diabetic Nephropathy: Protective Effects and Molecular Mechanism

Diabetic nephropathy (DN) is a serious complication of diabetes, and its progression is influenced by factors like oxidative stress, inflammation, cell death, and fibrosis. Compared to drug treatment, exercise offers a cost-effective and low-risk approach to slowing down DN progression. Through multiple ways and mechanisms, exercise helps to control blood sugar and blood pressure and reduce serum creatinine and albuminuria, thereby alleviating kidney damage. This review explores the beneficial effects of exercise on DN improvement and highlights its potential mechanisms for ameliorating DN. In-depth understanding of the role and mechanism of exercise in improving DN would pave the way for formulating safe and effective exercise programs for the treatment and prevention of DN.

Endothelial β-catenin upregulation and Y142 phosphorylation drive diabetic angiogenesis via upregulating KDR/HDAC9

BACKGROUND

Diabetic angiogenesis is closely associated with disabilities and death caused by diabetic microvascular complications. Advanced glycation end products (AGEs) are abnormally accumulated in diabetic patients and are a key pathogenic factor for diabetic angiogenesis. The present study focuses on understanding the mechanisms underlying diabetic angiogenesis and identifying therapeutic targets based on these mechanisms.

METHODS

In this study, AGE-induced angiogenesis serves as a model to investigate the mechanisms underlying diabetic angiogensis. Mouse aortic rings, matrigel plugs, and HUVECs or 293T cells were employed as research objects to explore this pathological process by using transcriptomics, gene promoter reporter assays, virtual screening and so on.

RESULTS

Here, we found that AGEs activated Wnt/β-catenin signaling pathway and enhanced the β-catenin protein level by affecting the expression of β-catenin degradation-related genes, such as FZDs (Frizzled receptors), LRPs (LDL Receptor Related Proteins), and AXIN1. AGEs could also mediate β-catenin Y142 phosphorylation through VEGFR1 isoform5. These dual effects of AGEs elevated the nuclear translocation of β-catenin and sequentially induced the expression of KDR (Kinase Insert Domain Receptor) and HDAC9 (Histone Deacetylase 9) by POU5F1 and NANOG, respectively, thus mediating angiogenesis. Finally, through virtual screening, Bioymifi, an inhibitor that blocks VEGFR1 isoform5-β-catenin complex interaction and alleviates AGE-induced angiogenesis, was identified.

CONCLUSION

Collectively, this study offers insight into the pathophysiological functions of β-catenin in diabetic angiogenesis.

L-shaped association between the GA/HbA1c ratio and all-cause mortality in U.S. adults with NAFLD: a cross-sectional study from the NHANES 1999-2004

OBJECTIVE

It is currently unclear whether there is a relationship between the ratio of glycated albumin to hemoglobin A1c (GA/HbA1c) and mortality in individuals diagnosed with nonalcoholic fatty liver disease (NAFLD). The primary objective of the study was to investigate the relationship between the GA/HbA1c ratio and all-cause mortality in adults with NAFLD in the U.S.

METHODS

The investigation included a total of 5,295 individuals aged ≥ 18 years who were diagnosed with NAFLD, these individuals were selected from the National Health and Nutrition Examination Survey conducted between 1999 and 2004. To evaluate the outcomes of death, the researchers relied on National Death Index (NDI) records up to December 31, 2019. To better understand the nonlinear relationship between the GA/HbA1c ratio and mortality among individuals with NAFLD, this study employed both subgroup and sensitivity analyses. Furthermore, Cox proportional hazards models and two-part Cox proportional hazards model were utilized.

RESULTS

The study included a total of 5,295 adult patients with NAFLD in the U.S. During a median follow-up period of 16.9 years, there were 1,471 recorded deaths, including 419 cardiovascular deaths. After accounting for various factors, a higher GA/HbA1c ratio exhibited a positive and nonlinear association with an increased risk of all-cause mortality in patients with NAFLD. Furthermore, the study revealed an L-shaped relationship between the GA/HbA1c ratio and all-cause mortality, with the inflection point occurring at a GA/HbA1c ratio of 2.21. When the GA/HbA1c ratio exceeded 2.21, each 1-unit increase in the ratio was associated with a 33% increase in the adjusted hazard ratio (HR 1.33; 95% CI 1.14, 1.60) for all-cause mortality.

CONCLUSIONS

A nonlinear correlation between the ratio of GA to HbA1c and all-cause mortality was observed in U.S. adults with NAFLD. In addition, an elevated GA/HbA1c ratio was linked to an increased risk of all-cause mortality in these patients.

Protective Factors and the Pathogenesis of Complications in Diabetes

Chronic complications of diabetes are due to myriad disorders of numerous metabolic pathways that are responsible for most of the morbidity and mortality associated with the disease. Traditionally, diabetes complications are divided into those of microvascular and macrovascular origin. We suggest revising this antiquated classification into diabetes complications of vascular, parenchymal, and hybrid (both vascular and parenchymal) tissue origin, since the profile of diabetes complications ranges from those involving only vascular tissues to those involving mostly parenchymal organs. A major paradigm shift has occurred in recent years regarding the pathogenesis of diabetes complications, in which the focus has shifted from studies on risks to those on the interplay between risk and protective factors. While risk factors are clearly important for the development of chronic complications in diabetes, recent studies have established that protective factors are equally significant in modulating the development and severity of diabetes complications. These protective responses may help explain the differential severity of complications, and even the lack of pathologies, in some tissues. Nevertheless, despite the growing number of studies on this field, comprehensive reviews on protective factors and their mechanisms of action are not available. This review thus focused on the clinical, biochemical, and molecular mechanisms that support the idea of endogenous protective factors, and their roles in the initiation and progression of chronic complications in diabetes. In addition, this review also aimed to identify the main needs of this field for future studies.

Skin Autofluorescence and Clinical Outcomes in Patients with Coronary Artery Disease

AIM

This study aimed to investigate whether skin autofluorescence (SAF) is associated with clinical outcomes in patients with coronary artery disease. Advanced glycation end products (AGE) play a crucial role in atherosclerosis. Accumulation of AGE can be measured non-invasively by SAF.

METHODS

We performed a single-center prospective study of 896 patients with coronary artery disease treated with percutaneous coronary intervention (PCI) between January 2014 and December 2015. SAF was measured before the PCI procedure. The primary endpoint was patient-oriented composite endpoints (POCE) defined as a composite of all-cause death, any myocardial infarction, any stroke, and any revascularization.

RESULTS

Patients were significantly older and suffered higher rates of chronic kidney disease (CKD) in the high SAF group. A higher SAF was associated with an increased risk for POCE (HR 1.43; 95% CI 1.19-1.71, p＜0.001) that was mainly driven by any coronary revascularization (HR 1.33; 95% CI 1.08-1.65, p=0.01) including target lesion revascularization (HR 1.41; 95% CI 1.02-1.94, p=0.04). The higher SAF group also experienced worse outcomes in stroke (HR 2.08; 95% CI 1.38-3.15, p=0.001). Multivariate analyses indicated that SAF was an independent predictor of POCE (HR 1.36; 95% CI 1.13-1.63, p=0.001).

CONCLUSIONS

SAF as a measure of AGE deposition is independently associated with cardiovascular events amongst patients with coronary artery disease treated with PCI. SAF also predicts the incidence of restenosis and stroke.

The NMR signature of maltose-based glycation in full-length proteins

Reducing sugars can spontaneously react with free amines in protein side chains leading to posttranslational modifications (PTMs) called glycation. In contrast to glycosylation, glycation is a non-enzymatic modification with consequences on the overall charge, solubility, aggregation susceptibility and functionality of a protein. Glycation is a critical quality attribute of therapeutic monoclonal antibodies. In addition to glucose, also disaccharides like maltose can form glycation products. We present here a detailed NMR analysis of the Amadori product formed between proteins and maltose. For better comparison, data collection was done under denaturing conditions using 7 M urea-d4 in D2O. The here presented correlation patterns serve as a signature and can be used to identify maltose-based glycation in any protein that can be denatured. In addition to the model protein BSA, which can be readily glycated, we present data of the biotherapeutic abatacept containing maltose in its formulation buffer. With this contribution, we demonstrate that NMR spectroscopy is an independent method for detecting maltose-based glycation, that is suited for cross-validation with other methods.

Accumulation of advanced glycation end products in skin and increased vascular ageing in the general population: the Malmö Offspring Study

OBJECTIVES

Advanced glycation end product (AGE) is an established risk marker for diabetic vascular disease, and associated with the degree of diabetes complications, renal failure, and atherosclerosis in middle-aged and older individuals. The relationship between AGEs and aortic stiffness has not been thoroughly examined in the younger general population. We aimed to evaluate the association between AGEs and aortic stiffness in the general population of young and middle-aged adults.

METHODS

We analysed cross-sectionally 2518 participants from a Swedish population-based cohort, the Malmö Offspring Study (mean age 41.8 ± 14.5 years, 52.2%). Advanced glycation end-products (AGEs) were measured by a well validated, noninvasive method using skin autofluorescence with AGE-Reader. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (PWV) and augmentation index (Aix) was calibrated to a standard heart rate of 75 bpm at the arteria radialis using SphygmoCor. Multivariable linear regression was performed stratified by age to analyse the association between skin AGE and aortic stiffness.

RESULTS

Increased levels of AGEs were significantly associated with higher direct measurements of aortic stiffness (vascular ageing) in younger individuals (PWV β 0.55 m/s, P  < 0.001) after adjustment for traditional cardiometabolic risk factors, however, not in older individuals (PWV β 0.23 m/s, P  = 0.10). Indirect vascular ageing was also significantly associated with higher levels of AGEs in both younger (Aix β 7.78, P  < 0.001) and older individuals (Aix β 3.69, P  < 0.001).

CONCLUSION

Higher levels of skin autofluorescence-AGEs are positively associated with increased vascular ageing in younger adults from the general population, independent of cardiometabolic risk factors.

Uterine Collagen Cross-Linking: Biology, Role in Disorders, and Therapeutic Implications

Collagen is an essential constituent of the uterine extracellular matrix that provides biomechanical strength, resilience, structural integrity, and the tensile properties necessary for the normal functioning of the uterus. Cross-linking is a fundamental step in collagen biosynthesis and is critical for its normal biophysical properties. This step occurs enzymatically via lysyl oxidase (LOX) or non-enzymatically with the production of advanced glycation end-products (AGEs). Cross-links found in uterine tissue include the reducible dehydro-dihydroxylysinonorleucine (deH-DHLNL), dehydro-hydroxylysinonorleucine (deH-HLNL), and histidinohydroxymerodesmosine (HHMD); and the non-reducible pyridinoline (PYD), deoxy-pyridinoline (DPD); and a trace of pentosidine (PEN). Collagen cross-links are instrumental for uterine tissue integrity and the continuation of a healthy pregnancy. Decreased cervical cross-link density is observed in preterm birth, whereas increased tissue stiffness caused by increased cross-link density is a pathogenic feature of uterine fibroids. AGEs disrupt embryo development, decidualization, implantation, and trophoblast invasion. Uterine collagen cross-linking regulators include steroid hormones, such as progesterone and estrogen, prostaglandins, proteoglycans, metalloproteinases, lysyl oxidases, nitric oxide, nicotine, and vitamin D. Thus, uterine collagen cross-linking presents an opportunity to design therapeutic targets and warrants further investigation in common uterine disorders, such as uterine fibroids, cervical insufficiency, preterm birth, dystocia, endometriosis, and adenomyosis.

Metabolic memory: mechanisms and diseases

Metabolic diseases and their complications impose health and economic burdens worldwide. Evidence from past experimental studies and clinical trials suggests our body may have the ability to remember the past metabolic environment, such as hyperglycemia or hyperlipidemia, thus leading to chronic inflammatory disorders and other diseases even after the elimination of these metabolic environments. The long-term effects of that aberrant metabolism on the body have been summarized as metabolic memory and are found to assume a crucial role in states of health and disease. Multiple molecular mechanisms collectively participate in metabolic memory management, resulting in different cellular alterations as well as tissue and organ dysfunctions, culminating in disease progression and even affecting offspring. The elucidation and expansion of the concept of metabolic memory provides more comprehensive insight into pathogenic mechanisms underlying metabolic diseases and complications and promises to be a new target in disease detection and management. Here, we retrace the history of relevant research on metabolic memory and summarize its salient characteristics. We provide a detailed discussion of the mechanisms by which metabolic memory may be involved in disease development at molecular, cellular, and organ levels, with emphasis on the impact of epigenetic modulations. Finally, we present some of the pivotal findings arguing in favor of targeting metabolic memory to develop therapeutic strategies for metabolic diseases and provide the latest reflections on the consequences of metabolic memory as well as their implications for human health and diseases.

Wound microenvironment self-adaptive all-in-one hydrogel for rapid healing of the diabetic wound

The natural healing of diabetic wounds is collectively impeded by multiple factors, including hyperglycemia, angiogenesis disorders, acute oxidative stress, and prolonged inflammation. Although considerable effort has been devoted to solving these problems, the treatment of diabetic wounds remains a major clinical obstacle. In light of this, we developed an innovative wound microenvironment self-adaptive hydrogel to promote the healing of diabetic wounds. The hydrogel was constructed by the crosslinking of 3-aminobenzeneboronic acid (PBA)-modified gelatin (Gel) and polyvinyl alcohol (PVA) by borate ester bonds, which showed high responsiveness to glucose. Meanwhile, the liposomes that encapsulated metformin, L-arginine, and L(+)-ascorbic acid were incorporated into the hydrogel framework. The hydrogel@lipo composite demonstrated shape adaptability, glucose responsiveness, and all-in-one capability, thereby effectively improving the intricate microenvironment of diabetic wounds. In vitro and in vivo experiments demonstrated the ability of hydrogel@lipo to mitigate oxidative stress, enhance angiogenesis, and attenuate inflammatory responses. Consequently, the hydrogel@lipo could accelerate diabetic wound healing (within two weeks). The cumulative findings strongly suggest the potential of hydrogel@lipo as a highly promising therapeutic dressing for advancing diabetic wound recovery.

Molecular Assessment of Methylglyoxal-Induced Toxicity and Therapeutic Approaches in Various Diseases: Exploring the Interplay with the Glyoxalase System

This comprehensive exploration delves into the intricate interplay of methylglyoxal (MG) and glyoxalase 1 (GLO I) in various physiological and pathological contexts. The linchpin of the narrative revolves around the role of these small molecules in age-related issues, diabetes, obesity, cardiovascular diseases, and neurodegenerative disorders. Methylglyoxal, a reactive dicarbonyl metabolite, takes center stage, becoming a principal player in the development of AGEs and contributing to cell and tissue dysfunction. The dual facets of GLO I-activation and inhibition-unfold as potential therapeutic avenues. Activators, spanning synthetic drugs like candesartan to natural compounds like polyphenols and isothiocyanates, aim to restore GLO I function. These molecular enhancers showcase promising outcomes in conditions such as diabetic retinopathy, kidney disease, and beyond. On the contrary, GLO I inhibitors emerge as crucial players in cancer treatment, offering new possibilities in diseases associated with inflammation and multidrug resistance. The symphony of small molecules, from GLO I activators to inhibitors, presents a nuanced understanding of MG regulation. From natural compounds to synthetic drugs, each element contributes to a molecular orchestra, promising novel interventions and personalized approaches in the pursuit of health and wellbeing. The abstract concludes with an emphasis on the necessity of rigorous clinical trials to validate these findings and acknowledges the importance of individual variability in the complex landscape of health.

Emerging and multifaceted potential contributions of polyphenols in the management of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is recognized as a serious public health concern with a considerable impact on human life, long-term health expenditures, and substantial health losses. In this context, the use of dietary polyphenols to prevent and manage T2DM is widely documented. These dietary compounds exert their beneficial effects through several actions, including the protection of pancreatic islet β-cell, the antioxidant capacities of these molecules, their effects on insulin secretion and actions, the regulation of intestinal microbiota, and their contribution to ameliorate diabetic complications, particularly those of vascular origin. In the present review, we intend to highlight these multifaceted actions and the molecular mechanisms by which these plant-derived secondary metabolites exert their beneficial effects on type 2 diabetes patients.

Classical and Innovative Evidence for Therapeutic Strategies in Retinal Dysfunctions

The human retina is a complex anatomical structure that has no regenerative capacity. The pathogenesis of most retinopathies can be attributed to inflammation, with the activation of the inflammasome protein platform, and to the impact of oxidative stress on the regulation of apoptosis and autophagy/mitophagy in retinal cells. In recent years, new therapeutic approaches to treat retinopathies have been investigated. Experimental data suggest that the secretome of mesenchymal cells could reduce oxidative stress, autophagy, and the apoptosis of retinal cells, and in turn, the secretome of the latter could induce changes in mesenchymal cells. Other studies have evidenced that noncoding (nc)RNAs might be new targets for retinopathy treatment and novel disease biomarkers since a correlation has been found between ncRNA levels and retinopathies. A new field to explore is the interaction observed between the ocular and intestinal microbiota; indeed, recent findings have shown that the alteration of gut microbiota seems to be linked to ocular diseases, suggesting a gut-eye axis. To explore new therapeutical strategies for retinopathies, it is important to use proper models that can mimic the complexity of the retina. In this context, retinal organoids represent a good model for the study of the pathophysiology of the retina.

Non-enzymatic glycation and diabetic kidney disease

Chronic diabetes leads to various complications including diabetic kidney disease (DKD). DKD is a major microvascular complication and the leading cause of morbidity and mortality in diabetic patients. Varying degrees of proteinuria and reduced glomerular filtration rate are the cardinal clinical manifestations of DKD that eventually progress into end-stage renal disease. Histopathologically, DKD is characterized by renal hypertrophy, mesangial expansion, podocyte injury, glomerulosclerosis, and tubulointerstitial fibrosis, ultimately leading to renal replacement therapy. Amongst the many mechanisms, hyperglycemia contributes to the pathogenesis of DKD via a mechanism known as non-enzymatic glycation (NEG). NEG is the irreversible conjugation of reducing sugars onto a free amino group of proteins by a series of events, resulting in the formation of initial Schiff's base and an Amadori product and to a variety of advanced glycation end products (AGEs). AGEs interact with cognate receptors and evoke aberrant signaling cascades that execute adverse events such as oxidative stress, inflammation, phenotypic switch, complement activation, and cell death in different kidney cells. Elevated levels of AGEs and their receptors were associated with clinical and morphological manifestations of DKD. In this chapter, we discussed the mechanism of AGEs accumulation, AGEs-induced cellular and molecular events in the kidney and their impact on the pathogenesis of DKD. We have also reflected upon the possible options to curtail the AGEs accumulation and approaches to prevent AGEs mediated adverse renal outcomes.