Advanced glycation end products (AGE) and diabetes: cause, effect, or both?

Role of advanced glycation end products in diabetic vascular injury: molecular mechanisms and therapeutic perspectives

BACKGROUND

In diabetic metabolic disorders, advanced glycation end products (AGEs) contribute significantly to the development of cardiovascular diseases (CVD).

AIMS

This comprehensive review aims to elucidate the molecular mechanisms underlying AGE-mediated vascular injury.

CONCLUSIONS

We discuss the formation and accumulation of AGEs, their interactions with cellular receptors, and the subsequent activation of signaling pathways leading to oxidative stress, inflammation, endothelial dysfunction, smooth muscle cell proliferation, extracellular matrix remodeling, and impaired angiogenesis. Moreover, we explore potential therapeutic strategies targeting AGEs and related pathways for CVD prevention and treatment in diabetic metabolic disorders. Finally, we address current challenges and future directions in the field, emphasizing the importance of understanding the molecular links between AGEs and vascular injury to improve patient outcomes.

Stem cells as a regenerative medicine approach in treatment of microvascular diabetic complications

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by high blood glucose and is associated with high morbidity and mortality among the diabetic population. Uncontrolled chronic hyperglycaemia causes increased formation and accumulation of different oxidative and nitrosative stress markers, resulting in microvascular and macrovascular complications, which might seriously affect the quality of a patient's life. Conventional treatment strategies are confined to controlling blood glucose by regulating the insulin level and are not involved in attenuating the life-threatening complications of diabetes mellitus. Thus, there is an unmet need to develop a viable treatment strategy that could target the multi-etiological factors involved in the pathogenesis of diabetic complications. Stem cell therapy, a regenerative medicine approach, has been investigated in diabetic complications owing to their unique characteristic features of self-renewal, multilineage differentiation and regeneration potential. The present review is focused on potential therapeutic applications of stem cells in the treatment of microvascular diabetic complications such as nephropathy, retinopathy, and polyneuropathy.

Keeping an eye on the nutrition: The importance of nutrition management on cardiometabolic risk factors in cirrhotic patients

Chronic liver diseases, especially cirrhosis, are associated with significant morbidity and mortality. Besides predisposing to chronic liver disease per se, diabetes, hypertension, and dyslipidemia worsen the prognosis of patients with cirrhosis induced by other causes. There is no standard of care in the management of these factors in patients with cirrhosis. Also, in particular, it is not known whether nutritional interventions in the modification of cardiometabolic factors can improve the course of cirrhosis or not. This narrative review aimed to investigate the clinical significance of diabetes, hypertension, and dyslipidemia and appropriate nutritional interventions in cirrhotic patients. A comprehensive literature search of the published data was performed in regard to the association of cirrhosis with cardiometabolic factors and the management of cirrhosis and its complications. There is limited evidence on the association of cirrhosis with cardiometabolic risk factors. Cirrhotic cardiometabolic abnormalities are associated with an increased risk of complications, such that the coexistence of diabetes, hypertension, and dyslipidemia increases the risk of clinical decompensation in cirrhosis. Dietary management of cirrhotic patients with risk factors such as diabetes, hypertension, or dyslipidemia does not seem to be considerably different from non-cirrhotic patients.

Flavonols as a Potential Pharmacological Intervention for Alleviating Cognitive Decline in Diabetes: Evidence from Preclinical Studies

Diabetes mellitus is a complex metabolic disease associated with reduced synaptic plasticity, atrophy of the hippocampus, and cognitive decline. Cognitive impairment results from several pathological mechanisms, including increased levels of advanced glycation end products (AGEs) and their receptors, prolonged oxidative stress and impaired activity of endogenous mechanisms of antioxidant defense, neuroinflammation driven by the nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB), decreased expression of brain-derived neurotrophic factor (BDNF), and disturbance of signaling pathways involved in neuronal survival and cognitive functioning. There is increasing evidence that dietary interventions can reduce the risk of various diabetic complications. In this context, flavonols, a highly abundant class of flavonoids in the human diet, are appreciated as a potential pharmacological intervention against cognitive decline in diabetes. In preclinical studies, flavonols have shown neuroprotective, antioxidative, anti-inflammatory, and memory-enhancing properties based on their ability to regulate glucose levels, attenuate oxidative stress and inflammation, promote the expression of neurotrophic factors, and regulate signaling pathways. The present review gives an overview of the molecular mechanisms involved in diabetes-induced cognitive dysfunctions and the results of preclinical studies showing that flavonols have the ability to alleviate cognitive impairment. Although the results from animal studies are promising, clinical and epidemiological studies are still needed to advance our knowledge on the potential of flavonols to improve cognitive decline in diabetic patients.

Anti-protein glycation and free-radical scavenging properties of Sri Lankan antidiabetic medicinal plant Salacia reticulata l. (Kothala Himbutu)

BACKGROUND

Decoctions of the root and stem of the medicinal plant Salacia reticulata is an indigenous remedy for diabetics and its complications in Sri Lanka. In diabetics, the formation of advanced glycation end products (AGEs) leads to many pathologies. Nevertheless, the anti-protein-glycation property of this plant is poorly documented. This study reports the anti-protein-glycation and radical scavenging potential of various plant parts of S. reticulata.

METHODS

Hot water extracts (2g dried powder/50 ml) of root, stem, leaf, twigs, and fruits at various concentrations (15.6 to 500.0 µg/ml) were subjected to anti-glycation and glycation reversing assays in vitro. 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was used for free radical scavenging property.

RESULTS

Various plant parts of S. reticulata showed anti-protein-glycation and free-radical scavenging activities. IC50 for the anti-glycation activity of root, stem, leaf, twigs, and fruit extracts were 11.92 ± 1.14, 35.18 ± 2.79, 113.3 ± 1.91, 149.59 ± 1.06, and 1120.37 ± 229.48 µg/ml respectively. IC50 of Rutin was 21.88 ± 2.82 µg/ml. EC50 of the root, stem, twigs, and leaf extracts for glycation reversing was 102.09 ± 6.23, 116.99 ± 5.82, 154.45 ± 5.79, and 278.78 ± 14.19 µg/ml respectively. The EC50 values for the radical scavenging activity of leaf, stem, and roots were 26.4±4.7, 9.0±1.2, and 9.1±1.3 respectively. Root had significantly (p<0.05) high activity for all the parameters tested.

CONCLUSION

Salacia reticulata possess anti-glycation, glycation-reversing, and free radical scavenging activities. Other than root and stem, the leaves and twigs too may be a useful source for anti-diabetic bioactive molecules.

Effects of different doses of exercise in adjunct to diet-induced weight loss on the AGE-RAGE axis in patients with short standing type 2 diabetes: Secondary analysis of the DOSE-EX multi-arm, parallel-group, randomised trial

AIMS/HYPOTHESIS

These secondary analyses aimed to investigate the effects of different volumes of exercise in adjunct to diet-induced weight loss and standard care on advanced glycation end-products (AGEs) and receptor for AGE (RAGE). We hypothesized that exercise in adjunct to a diet-induced weight loss would dose-dependently increase the soluble decoy receptor for AGE (sRAGE) more than diet-induced weight loss and standard care alone. Secondarily, we expected changes in sRAGE to be associated with improved glycaemic control and inversely associated with low-grade inflammation.

METHODS

The DOSE-EX study was a 16-week parallel-group, 4-arm, single-centre, assessor-blinded, randomised, controlled trial (NCT03769883). We included persons living with T2D, duration ≤7 years, BMI >27 kg/m2 and <40 kg/m2, without severe diabetic complications. Participants were randomised (1:1:1:1) to either 1) standard care as control (CON), 2) standard care + diet (DCON), 3) standard care + diet + moderate exercise dose (MED) or 4) standard care + diet + high exercise dose (HED). Standard care included algorithm-guided pharmacological treatment. The diet intervention aimed at 25% reduced energy intake. The supervised exercise sessions included two aerobic sessions + one combined (aerobic and resistance training) session per week for the MED group, and four aerobic sessions + two combined sessions per week for the HED group. Primary outcome was the change in sRAGE from baseline to 16-week follow-up. Secondary outcomes encompassed changes in advanced glycation endproducts (AGE), glycaemic control and markers of low-grade inflammation.

RESULTS

A total of 80 participants (CON: n = 20, DCON: n = 19, MED: n = 20, HED: n = 21) were included in this secondary analysis. The mean age was 58.3 years (SD 9.9), 53% males, and median T2D duration was 4.1 years (IQR 2.0-5.5). No change in sRAGE was observed in any of the groups from baseline to follow-up (p > 0.05).

CONCLUSION/INTERPRETATION

A 16-week intervention with either three or six exercise sessions per week in adjunct to diet-induced weight loss did not change the levels of sRAGE in persons living with well-regulated, short standing T2D.

Advances and Perspectives in Relation to the Molecular Basis of Diabetic Retinopathy-A Review

Diabetes mellitus (DM) is a growing problem nowadays, and diabetic retinopathy (DR) is its predominant complication. Currently, DR diagnosis primarily relies on fundoscopic examination; however, novel biomarkers may facilitate that process and make it widely available. In this current review, we delve into the intricate roles of various factors and mechanisms in DR development, progression, prediction, and their association with therapeutic approaches linked to the underlying pathogenic pathways. Specifically, we focus on advanced glycation end products, vascular endothelial growth factor (VEGF), asymmetric dimethylarginine, endothelin-1, and the epigenetic regulation mediated by microRNAs (miRNAs) in the context of DR.

Effect of diet low in advanced glycation end products on appetite, body composition, and brown adipose tissue markers in patients with coronary artery disease treated with angioplasty: A randomized controlled trial

Background

Recent changes in dietary habits have resulted in increased intake of advanced glycation end products (AGEs), which are known to have a predominant contribution to the pathogenesis and complications of coronary artery disease (CAD). AGEs are also thought to induce weight gain by affecting appetite, energy expenditure, and brown adipose tissue (BAT). Here, we investigated whether the restriction of dietary AGEs could affect appetite, body composition, anthropometric indices, and BAT-derived markers in CAD patients treated with angioplasty.

Materials and Methods

Forty-two stented CAD patients were randomly allocated into two groups that received either a low-AGEs or a control diet for 12 weeks. At baseline and postintervention, fasting blood samples were analyzed for total AGEs, nesfatin-1, and BAT-derived markers (fibroblast growth factor 21 and neuregulin 4). Subjective appetite ratings and body composition were evaluated using the Visual Analog Scale (VAS) and bioelectric impedance analysis. Anthropometric indices, including fat mass index (FMI), abdominal volume index (AVI), and body adiposity index (BAI), were calculated through the relevant formula.

Results

Restricting dietary AGEs for 12 weeks could cause a significant reduction in weight, FMI, AVI, and BAI (P < 0.05) compared to the comparison group. In addition, VAS data analyses indicated a significant decrease in the sense of hunger and prospective food intake (P < 0.05) in the intervention group compared to the comparison group. No significant difference was seen in the measured biochemical markers between the two groups.

Conclusion

This study indicated that the low-AGEs diet could decrease appetite, weight, and anthropometric indices in stented CAD patients.

The Cellular and Protein Arms of Coagulation in Diabetes: Established and Potential Targets for the Reduction of Thrombotic Risk

Diabetes is a metabolic condition with a rising global prevalence and is characterised by abnormally high blood glucose levels. Cardiovascular disease (CVD) accounts for the majority of deaths in diabetes and, despite improvements in therapy, mortality and hospitalisations in this cohort remain disproportionally higher compared to individuals with normal glucose metabolism. One mechanism for increased CVD risk is enhanced thrombosis potential, due to altered function of the cellular and acellular arms of coagulation. Different mechanisms have been identified that mediate disordered blood clot formation and breakdown in diabetes, including dysglycaemia, insulin resistance, and metabolic co-morbidities. Collectively, these induce platelet/endothelial dysfunction and impair the fibrinolytic process, thus creating a prothrombotic milieu. Despite these abnormalities, current antithrombotic therapies are largely similar in diabetes compared to those without this condition, which explains the high proportion of patients experiencing treatment failure while also displaying an increased risk of bleeding events. In this narrative review, we aimed to summarise the physiological functioning of haemostasis followed by the pathological effects of diabetes mellitus on platelets and the fibrin network. Moreover, we carefully reviewed the literature to describe the current and future therapeutic targets to lower the thrombosis risk and improve vascular outcomes in diabetes.

Extraction Methods, Properties, Functions, and Interactions with Other Nutrients of Lotus Procyanidins: A Review

Lotus procyanidins, natural polyphenolic compounds isolated from the lotus plant family, are widely recognized as potent antioxidants that scavenge free radicals in the human body and exhibit various pharmacological effects, such as anti-inflammatory, anticancer, antiobesity, and hypoglycemic. With promising applications in food and healthcare, lotus procyanidins have attracted extensive attention in recent years. This review provides a comprehensive summary of current research on lotus procyanidins, including extraction methods, properties, functions, and interactions with other nutrient components. Furthermore, this review offers an outlook on future research directions, providing ideas and references for the exploitation and utilization of lotus.

Staphylococcus aureus Adaptation to the Skin in Health and Persistent/Recurrent Infections

Staphylococcus aureus is a microorganism with an incredible capability to adapt to different niches within the human body. Approximately between 20 and 30% of the population is permanently but asymptomatically colonized with S. aureus in the nose, and another 30% may carry S. aureus intermittently. It has been established that nasal colonization is a risk factor for infection in other body sites, including mild to severe skin and soft tissue infections. The skin has distinct features that make it a hostile niche for many bacteria, therefore acting as a strong barrier against invading microorganisms. Healthy skin is desiccated; it has a low pH at the surface; the upper layer is constantly shed to remove attached bacteria; and several host antimicrobial peptides are produced. However, S. aureus is able to overcome these defenses and colonize this microenvironment. Moreover, this bacterium can very efficiently adapt to the stressors present in the skin under pathological conditions, as it occurs in patients with atopic dermatitis or suffering chronic wounds associated with diabetes. The focus of this manuscript is to revise the current knowledge concerning how S. aureus adapts to such diverse skin conditions causing persistent and recurrent infections.

AGEs induce high expression of Dll4 via endoplasmic reticulum stress PERK signaling-mediated internal ribosomal entry site mechanism in macrophages

Background and aim

Advanced glycation end products (AGEs)- exposed macrophages was characterized by Delta-like ligand 4 (Dll4) high expressed and has been shown to participate in diabetes-related atherosclerosis. This study was aimed to investigate the translational regulatory mechanism of Dll4 high expression in macrophages exposed to AGEs.

Methods

Human Dll4 5' untranslated region (5'UTR) sequence was cloned and inserted into a bicistronic reporter plasmid. Human THP-1 macrophages transfected with the bicistronic reporter plasmids were exposed to AGEs. Dual-luciferase assay was used to detect internal ribosome entry site (IRES) activity contained in Dll4 5'UTR. Small interference RNA transfection was used to knock-down specific gene expression. Localization of protein was analyzed.

Results

AGEs exposure significantly induced IRES activity in Dll4 5' UTR in human macrophages. Internal potential promoter and ribosome read-through mechanisms were excluded. Inhibition of endoplasmic reticulum stress and specific silencing of protein kinase R-like endoplasmic reticulum kinase (PERK)/eukaryotic initiation factor 2α (eIF2α) signaling pathway activation reduced IRES activity in Dll4 5' UTR in human macrophages. Dll4 5' UTR IRES activity was also inhibited by targeted silencing of heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1). Moreover, specific inhibition of PERK/eIF2α signaling pathway led to deactivation of hnRNPA1, resulting to reduction of AGEs- induced Dll4 5' UTR IRES activity in human macrophages.

Conclusions

AGEs induced Dll4 5' UTR IRES activity in human macrophages which was dependent on endoplasmic reticulum stress PERK/eIF2α signaling pathway. hnRNPA1 acted the role as an ITAF was also indispensable for AGEs-induced Dll4 5'UTR IRES activity in human macrophages.

AGEs and RAGE: metabolic and molecular signatures of the glycation-inflammation axis in malignant or metastatic cancers

From attributing mutations to cancers with the advent of cutting-edge genetic technology in recent decades, to re-searching the age-old theory of intrinsic metabolic shift of cancers (Warburg's glycolysis), the quest for a precise panacea for mainly the metastatic cancers, remains incessant. This review delineates the advanced glycation end product (AGE)-receptor for AGE (RAGE) pathway driven intricate oncogenic cues, budding from the metabolic (glycolytic) reliance of tumour cells, branching into metastatic emergence of malignancies. Strong AGE-RAGE concomitance in metastasis, chemo-resistance and cancer resurgence adversely incite disease progression and patient mortality. At the conjunction of metabolic and metastatic shift of cancers, are the "glycolytically" generated AGEs and AGE-activated RAGE, instigating aberrant molecular pathways, culminating in aggressive malignancies. AGEs as by-products of metabolic insurgence, modify the metabolome, epigenome and microbiome, besides coercing the inter-, intra- and extra-cellular micro-milieu conducive for oncogenic events like epithelial-mesenchymal transition (EMT). AGE-RAGE synergistically elicit ATP surge for surplus energy, autophagy for apoptotic evasion and chemo-resistance, insulin-like growth factor 1 (IGF-1) for meta-inflammation and angiogenesis, high mobility group box-1 (HMGB1) for immune tolerance, S100 proteins for metastasis, and p53 protein attenuation for tumour suppression. AGEs are pronouncedly reported in invasive forms of breast, prostate, colon and pancreatic cancers, higher in patients with cancer than healthy counterparts, and higher in advanced stage than localized phase. Hence, the investigation of person-specific presence of AGEs, soluble RAGE and AGE-activated RAGE can be advocated as impending bio-markers for diagnostic, prognostic and therapeutic purposes, to predict cancer risk in patients with diabetes, obesity, metabolic syndrome as well as general population, to monitor prognosis and metastasis in patients with cancer, and to reckon complications in cancer survivors. Furthermore, clinical reports of exogenous (dietary) and endogenous (internally formed) AGEs in cancer patients, and contemporary clinical trials involving AGE-RAGE axis in cancer are underlined with theranostic implications.

Protective effect of heat-processed Gynostemma pentaphyllum on high fat diet-induced glucose metabolic disorders mice

Glucose metabolic disorders (GMD) can promote insulin resistance (IR) and diabetes, and damage liver and kidney. Gynostemma pentaphyllum is commonly used in the clinical treatment of diabetes, but the research on its main active constituents and GMD has not been reported yet. This study explores the therapeutic potential of gypenosides of heat-processed Gynostemma pentaphyllum (HGyp) on high-fat diet-induced GMD in mice. HGyp was administered at different doses for 12 weeks. The investigation encompassed an array of parameters, including body weight, blood lipids, blood glucose, and liver tissue components. Metabolomic and network analyses were conducted to uncover potential targets and pathways associated with HGyp treatment. The results revealed that HGyp alleviated GMD by reducing body weight, blood glucose, and improving blood lipids levels, while increasing liver glycogen and antioxidant enzyme levels. Additionally, HGyp exhibited protective effects on liver and kidney health by reducing tissue damage. Fourteen blood components were detected by LC-MS. Metabolomic and network analyses indicated the potential engagement of the AGE-RAGE signaling pathway in the therapeutic effects of HGyp.Furthermore, Western blot and ELISA assays confirmed that HGyp upregulated GLO1 and GLUT4 while down-regulating AGEs and RAGE expression in liver tissue. In light of these findings, HGyp demonstrates promise as a potential therapeutic candidate for combating GMD, warranting further exploration in the development of therapeutic strategies or functional products.

Mechanism of the antidiabetic action of Nigella sativa and Thymoquinone: a review

Introduction

Long used in traditional medicine, Nigella sativa (NS; Ranunculaceae) has shown significant efficacy as an adjuvant therapy for diabetes mellitus (DM) management by improving glucose tolerance, decreasing hepatic gluconeogenesis, normalizing blood sugar and lipid imbalance, and stimulating insulin secretion from pancreatic cells. In this review, the pharmacological and pharmacokinetic properties of NS as a herbal diabetes medication are examined in depth, demonstrating how it counteracts oxidative stress and the onset and progression of DM.

Methods

This literature review drew on databases such as Google Scholar and PubMed and various gray literature sources using search terms like the etiology of diabetes, conventional versus herbal therapy, subclinical pharmacology, pharmacokinetics, physiology, behavior, and clinical outcomes.

Results

The efficiency and safety of NS in diabetes, notably its thymoquinone (TQ) rich volatile oil, have drawn great attention from researchers in recent years; the specific therapeutic dose has eluded determination so far. TQ has anti-diabetic, anti-inflammatory, antioxidant, and immunomodulatory properties but has not proved druggable. DM's intimate link with oxidative stress, makes NS therapy relevant since it is a potent antioxidant that energizes the cell's endogenous arsenal of antioxidant enzymes. NS attenuates insulin resistance, enhances insulin signaling, suppresses cyclooxygenase-2, upregulates insulin-like growth factor-1, and prevents endothelial dysfunction in DM.

Conclusion

The interaction of NS with mainstream drugs, gut microbiota, and probiotics opens new possibilities for innovative therapies. Despite its strong potential to treat DM, NS and TQ must be examined in more inclusive clinical studies targeting underrepresented patient populations.

Glucagon-like peptide 1 (GLP-1) receptor agonists in experimental Alzheimer's disease models: a systematic review and meta-analysis of preclinical studies

Alzheimer's disease (AD) is a degenerative disease of the nervous system. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs), a drug used to treat type 2 diabetes, have been shown to have neuroprotective effects. This systematic review and meta-analysis evaluated the effects and potential mechanisms of GLP-1 RAs in AD animal models. 26 studies were included by searching relevant studies from seven databases according to a predefined search strategy and inclusion criteria. Methodological quality was assessed using SYRCLE's risk of bias tool, and statistical analysis was performed using ReviewManger 5.3. The results showed that, in terms of behavioral tests, GLP-1 RAs could improve the learning and memory abilities of AD rodents; in terms of pathology, GLP-1 RAs could reduce Aβ deposition and phosphorylated tau levels in the brains of AD rodents. The therapeutic potential of GLP-1 RAs in AD involves a range of mechanisms that work synergistically to enhance the alleviation of various pathological manifestations associated with the condition. A total of five clinical trials were retrieved from ClinicalTrials.gov. More large-scale and high-quality preclinical trials should be conducted to more accurately assess the therapeutic effects of GLP-1 RAs on AD.

The Synergistic Influence of Polyflavonoids from Citrus aurantifolia on Diabetes Treatment and Their Modulation of the PI3K/AKT/FOXO1 Signaling Pathways: Molecular Docking Analyses and In Vivo Investigations

This study was aimed at probing the modulatory influence of polyflavonoids extracted from Citrus aurantifolia, lemon peel extract (LPE-polyflavonoids), on attenuating diabetes mellitus (DM) and its complications. HPLC investigations of the LPE exhibited the incidence of five flavonoids, including diosmin, biochanin A, hesperidin, quercetin, and hesperetin. The in silico impact on ligand-phosphatidylinositol 3-kinase (PI3K) interaction was investigated in terms of polyflavonoid class to explore the non-covalent intakes and binding affinity to the known protein active site. The drug likeness properties and pharmacokinetic parameters of the LPE-polyflavonoids were investigated to assess their bioavailability in relation to Myricetin as a control. Remarkably, the molecular docking studies demonstrated a prominent affinity score of all these agents together with PI3K, implying the potency of the extract to orchestrate PI3K, which is the predominant signal for lessening the level of blood glucose. To verify these findings, in vivo studies were conducted, utilizing diabetic male albino rats treated with LPE-polyflavonoids and other groups treated with hesperidin and diosmin as single flavonoids. Our findings demonstrated that the LPE-polyflavonoids significantly ameliorated the levels of glucose, insulin, glycogen, liver function, carbohydrate metabolizing enzymes, G6Pd, and AGEs compared to the diabetic rats and those exposed to hesperidin and diosmin. Furthermore, the LPE-polyflavonoids regulated the TBARS, GSH, CAT, TNF-α, IL-1β, IL-6, and AFP levels in the pancreatic and hepatic tissues, suggesting their antioxidant and anti-inflammatory properties. In addition, the pancreatic and hepatic GLUT4 and GLUT2 were noticeably increased in addition to the pancreatic p-AKT in the rats administered with the LPE-polyflavonoids compared to the other diabetic rats. Remarkably, the administration of LPE-polyflavonoids upregulated the expression of the pancreatic and hepatic PI3K, AMPK, and FOXO1 genes, emphasizing the efficiency of the LPE in orchestrating all the signaling pathways necessitated to reduce the diabetes mellitus. Notably, the histopathological examinations of the pancreatic and hepatic tissues corroborated the biochemical results. Altogether, our findings accentuated the potential therapeutic role of LPE-polyflavonoids in controlling diabetes mellitus.

Bone Mineral Density Evaluation Among Type 2 Diabetic Patients in Rural Haryana, India: An Analytical Cross-Sectional Study

Background and objective Diabetes is one of the most prevalent diseases globally, affecting almost all organ systems. The relationship between type 2 diabetes mellitus (T2DM) and bone mineral density (BMD) has been a matter of controversy, and data from developing countries in this regard is highly scarce. Early detection of low BMD in diabetic patients will help prevent further bone loss and risk of fragility fracture. In this study, we aimed to assess the effect of T2DM on BMD among the rural population of Haryana, India. Materials and methods This was a cross-sectional study involving 850 patients between 25 and 60 years of age, including 425 diabetic and 425 non-diabetic subjects (as controls). Calcaneus BMD was measured by using quantitative ultrasound (QUS), and the data were compared against matched parameters in both groups. Results The mean age of diabetics was 42.21 ± 10.5 years and that of non-diabetics was 42.18 ± 10.4 years. The mean BMI was 27.8 ± 4.17 kg/m2 in diabetics and 21.6 ± 3.32 kg/m2 in the non-diabetic control group. BMD values significantly differed between the groups: -4.3 ± 1.23 vs. -2.6 ± 0.34 in diabetics and non-diabetics, respectively (p=0.002). Conclusion A significant difference in BMD was observed between the diabetic and non-diabetic groups. Based on our findings, We recommend that all type 2 diabetics be screened for osteoporosis so that this silent bone loss can be detected in the early phase itself and appropriate preventive measures can be promptly initiated.

The hidden players: Shedding light on the significance of post-translational modifications and miRNAs in Alzheimer's disease development

Alzheimer's disease (AD) is the most prevalent, expensive, lethal, and burdening neurodegenerative disease of this century. The initial stages of this disease are characterized by a reduced ability to encode and store new memories. Subsequent cognitive and behavioral deterioration occurs during the later stages. Abnormal cleavage of amyloid precursor protein (APP) resulting in amyloid-beta (Aβ) accumulation along with hyperphosphorylation of tau protein are the two characteristic hallmarks of AD. Recently, several post-translational modifications (PTMs) have been identified on both Aβ as well as tau proteins. However, a complete understanding of how different PTMs influence the structure and function of proteins in both healthy and diseased conditions is still lacking. It has been speculated that these PTMs might play vital roles in the progression of AD. In addition, several short non-coding microRNA (miRNA) sequences have been found to be deregulated in the peripheral blood of Alzheimer patients. The miRNAs are single-stranded RNAs that control gene expression by causing mRNA degradation, deadenylation, or translational repression and have been implicated in the regulation of several neuronal and glial activities. The lack of comprehensive understanding regarding disease mechanisms, biomarkers, and therapeutic targets greatly hampers the development of effective strategies for early diagnosis and the identification of viable therapeutic targets. Moreover, existing treatment options for managing the disease have proven to be ineffective and provide only temporary relief. Therefore, understanding the role of miRNAs and PTMs in AD can provide valuable insights into disease mechanisms, aid in the identification of biomarkers, facilitate the discovery of novel therapeutic targets, and inspire innovative treatments for this challenging condition.

Organosulfurs, S-allyl cysteine and N-acetyl cysteine sequester di-carbonyls and reduces carbonyl stress in HT22 cells

Diabetes, characterized by high blood glucose level, is a progressive metabolic disease that leads to serious health complications. One of the major pathological consequences associated with diabetes is the accumulation of highly reactive carbonyl compounds called advanced glycation end products (AGEs). Most of the AGEs are dicarbonyls and have the potential to covalently modify proteins especially at the lysine residues in a non-enzymatic fashion (a process termed as glycation) resulting in the functional impairment and/or toxic gain in function. Therefore, non-toxic small molecules that can inhibit glycation are of interest for the therapeutic intervention of diabetes. In the present communication, we have investigated the effect of organosulfurs (S-allyl cysteine, SAC and N-acetyl cysteine, NAC) that are major principal components of Allium sativa against the glycation of different proteins. We discovered that both SAC and NAC are potent anti-glycating agents. We also found that both SAC and NAC reduce ROS level and inhibit apoptosis caused by protein glycation.

Alpha cell receptor for advanced glycation end products associate with glucagon expression in type 1 diabetes

Hypoglycemia in type 1 diabetes associates with changes in the pancreatic islet α cells, where the receptor for advanced glycation end products (RAGE) is highly expressed. This study compared islet RAGE expression in donors without diabetes, those at risk of, and those with type 1 diabetes. Laser-dissected islets were subject to RNA bioinformatics and adjacent pancreatic tissue were assessed by confocal microscopy. We found that islets from type 1 diabetes donors had differential expression of the RAGE gene (AGER) and its correlated genes, based on glucagon expression. Random forest machine learning revealed that AGER was the most important predictor for islet glucagon levels. Conversely, a generalized linear model identified that glucagon expression could be predicted by expression of RAGE signaling molecules, its ligands and enzymes that create or clear RAGE ligands. Confocal imaging co-localized RAGE, its ligands and signaling molecules to the α cells. Half of the type 1 diabetes cohort comprised of adolescents and a patient with history of hypoglycemia-all showed an inverse relationship between glucagon and RAGE. These data confirm an association between glucagon and islet RAGE, its ligands and signaling pathways in type 1 diabetes, which warrants functional investigation into a role for RAGE in hypoglycemia.

Nanopore Sequencing of RAGE Gene Polymorphisms and Their Association with Type 2 Diabetes

The receptor for advanced glycation end products (RAGE) is a transmembrane protein that interacts with its ligands, advanced glycation end products (AGEs). AGEs are elevated in diabetes and diabetic complications, leading to increased oxidative stress and activation of pro-inflammatory pathways facilitated by AGE-RAGE signaling. Polymorphisms in the RAGE gene can potentially affect AGE-RAGE interaction and its downstream signaling, which plays a crucial role in the progression of diabetes and its complications. In this study, we used nanopore sequencing for genotyping of RAGE polymorphism and identified a maximum number of 33 polymorphisms, including two previously unreported novel mutations in a cohort of healthy, type 2 diabetics without nephropathy and type 2 diabetics with nephropathy in order to identify associations. Two novel RAGE polymorphisms in the intron 8 and 3'UTR region at genomic locations 32181834 and 32181132, respectively, were detected with a low frequency. For four previously reported polymorphisms, cross-validation by PCR-RFLP showed 99.75% concordance with nanopore sequencing. Analysis of genotype distribution and allele frequencies revealed that five single nucleotide polymorphisms, i.e., rs1800625, rs3131300, rs3134940, rs2070600, and rs9391855, were associated with an increased risk for type 2 diabetes.

Role of neuroinflammation in neurodegeneration development

Studies in neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and Amyotrophic lateral sclerosis, Huntington's disease, and so on, have suggested that inflammation is not only a result of neurodegeneration but also a crucial player in this process. Protein aggregates which are very common pathological phenomenon in neurodegeneration can induce neuroinflammation which further aggravates protein aggregation and neurodegeneration. Actually, inflammation even happens earlier than protein aggregation. Neuroinflammation induced by genetic variations in CNS cells or by peripheral immune cells may induce protein deposition in some susceptible population. Numerous signaling pathways and a range of CNS cells have been suggested to be involved in the pathogenesis of neurodegeneration, although they are still far from being completely understood. Due to the limited success of traditional treatment methods, blocking or enhancing inflammatory signaling pathways involved in neurodegeneration are considered to be promising strategies for the therapy of neurodegenerative diseases, and many of them have got exciting results in animal models or clinical trials. Some of them, although very few, have been approved by FDA for clinical usage. Here we comprehensively review the factors affecting neuroinflammation and the major inflammatory signaling pathways involved in the pathogenicity of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Amyotrophic lateral sclerosis. We also summarize the current strategies, both in animal models and in the clinic, for the treatment of neurodegenerative diseases.

Continuous low serum levels of advanced glycation end products and low risk of cardiovascular disease in patients with poorly controlled type 2 diabetes

BACKGROUND

Type 2 diabetes is associated with an increased risk of developing cardiovascular events. Previous studies have reported that advanced glycation end products (AGEs) were related to cardiovascular events in type 2 diabetes. However, data on associations between long-term AGEs and cardiovascular events in type 2 diabetes are lacking. This study aimed to determine whether a long-time shift in the levels of serum AGEs is associated with cardiovascular events in patients with poorly controlled type 2 diabetes.

METHODS

Two-time serum methyl-glyoxal-hydroimidazoline (MG-H1) levels were measured in 138 patients with type 2 diabetes whose mean glycated hemoglobin level was 10.1%. We categorized patients whose serum MG-H1 levels were < 2.8 µg/mL at both times as the continuous low MG-H1 group. The primary endpoints of this study were combined cardiovascular events, which were defined as heart disease, peripheral arterial disease, stroke, and all-cause death. Hazard ratios (HRs) for combined cardiovascular events with 95% confidence intervals (CIs) were calculated using the Cox proportional hazard models to compare the outcomes between the continuous low MG-H1 group and others.

RESULTS

The continuous low MG-H1 group was associated with a significantly lower risk than others in combined cardiovascular events after adjusting for possible confounders (HR: 0.50; 95% CI, 0.28-0.87; P = 0.02). Furthermore, the same relationship was observed in patients without a history of cardiovascular events.

CONCLUSIONS

Continuous low serum MG-H1 levels are associated with a low frequency of diabetes-related complications in patients with poorly controlled type 2 diabetes.

Association between Diabetic Peripheral Neuropathy as Measured Using a Point-of-Care Sural Nerve Conduction Device and Urinary Albumin Excretion in Patients with Type 2 Diabetes

BACKGROUND

It is not well known whether diabetic peripheral neuropathy diagnosed using a non-invasive point-of-care nerve conduction device called DPN-Check^® is associated with diabetic nephropathy. Thus, we aimed to evaluate the association of diabetic peripheral neuropathy with urinary albumin excretion in patients with type 2 diabetes using DPN-Check^®.

METHODS

This retrospective observational study included 323 Japanese patients with type 2 diabetes. The urinary albumin-to-creatinine ratio in a spot urine sample was defined as urinary albumin excretion. Multiple linear regression analysis was used to determine the association of DPN-Check^®-determined diabetic peripheral neuropathy with urinary albumin excretion.

RESULTS

Patients with DPN-Check^®-determined diabetic peripheral neuropathy had significantly higher urinary albumin excretion than those without, while there was no difference in urinary albumin excretion between patients with and without diabetic peripheral neuropathy determined by simplified diagnostic criteria. In the multivariate model, the DPN-Check^® determined that diabetic peripheral neuropathy was significantly associated with urinary albumin excretion even after adjustment for covariates (standardized β, 0.123; p = 0.012).

CONCLUSIONS

Our study found a significant association between diabetic peripheral neuropathy diagnosed using DPN-Check^® and urinary albumin excretion in patients with type 2 diabetes.

Metformin inhibits methylglyoxal-induced retinal pigment epithelial cell death and retinopathy via AMPK-dependent mechanisms: Reversing mitochondrial dysfunction and upregulating glyoxalase 1

Diabetic retinopathy (DR) is a major cause of blindness in adult, and the accumulation of advanced glycation end products (AGEs) is a major pathologic event in DR. Methylglyoxal (MGO), a highly reactive dicarbonyl compound, is a precursor of AGEs. Although the therapeutic potential of metformin for retinopathy disorders has recently been elucidated, possibly through AMPK activation, it remains unknown how metformin directly affects the MGO-induced stress response in retinal pigment epithelial cells. Therefore, in this study, we compared the effects of metformin and the AMPK activator A769662 on MGO-induced DR in mice, as well as evaluated cytotoxicity, mitochondrial dynamic changes and dysfunction in ARPE-19 cells. We found MGO can induce mitochondrial ROS production and mitochondrial membrane potential loss, but reduce cytosolic ROS level in ARPE-19 cells. Although these effects of MGO can be reversed by both metformin and A769662, we demonstrated that reduction of mitochondrial ROS production rather than restoration of cytosolic ROS level contributes to cell protective effects of metformin and A769662. Moreover, MGO inhibits AMPK activity, reduces LC3II accumulation, and suppresses protein and gene expressions of MFN1, PGC-1α and TFAM, leading to mitochondrial fission, inhibition of mitochondrial biogenesis and autophagy. In contrast, these events of MGO were reversed by metformin in an AMPK-dependent manner as evidenced by the effects of compound C and AMPK silencing. In addition, we observed an AMPK-dependent upregulation of glyoxalase 1, a ubiquitous cellular enzyme that participates in the detoxification of MGO. In intravitreal drug-treated mice, we found that AMPK activators can reverse the MGO-induced cotton wool spots, macular edema and retinal damage. Functional, histological and optical coherence tomography analysis support the protective actions of both agents against MGO-elicited retinal damage. Metformin and A769662 via AMPK activation exert a strong protection against MGO-induced retinal pigment epithelial cell death and retinopathy. Therefore, metformin and AMPK activator can be therapeutic agents for DR.

Global Impacts of Western Diet and Its Effects on Metabolism and Health: A Narrative Review

The Western diet is a modern dietary pattern characterized by high intakes of pre-packaged foods, refined grains, red meat, processed meat, high-sugar drinks, candy, sweets, fried foods, conventionally raised animal products, high-fat dairy products, and high-fructose products. The present review aims to describe the effect of the Western pattern diet on the metabolism, inflammation, and antioxidant status; the impact on gut microbiota and mitochondrial fitness; the effect of on cardiovascular health, mental health, and cancer; and the sanitary cost of the Western diet. To achieve this goal, a consensus critical review was conducted using primary sources, such as scientific articles, and secondary sources, including bibliographic indexes, databases, and web pages. Scopus, Embase, Science Direct, Sports Discuss, ResearchGate, and the Web of Science were used to complete the assignment. MeSH-compliant keywords such "Western diet", "inflammation", "metabolic health", "metabolic fitness", "heart disease", "cancer", "oxidative stress", "mental health", and "metabolism" were used. The following exclusion criteria were applied: (i) studies with inappropriate or irrelevant topics, not germane to the review's primary focus; (ii) Ph.D. dissertations, proceedings of conferences, and unpublished studies. This information will allow for a better comprehension of this nutritional behavior and its effect on an individual's metabolism and health, as well as the impact on national sanitary systems. Finally, practical applications derived from this information are made.

AGER1 deficiency-triggered ferroptosis drives fibrosis progression in nonalcoholic steatohepatitis with type 2 diabetes mellitus

Hyperglycemia is an independent risk factor for the rapid progression of nonalcoholic steatohepatitis (NASH) to liver fibrosis with an incompletely defined mechanism. Ferroptosis is a novel form of programmed cell death that has been identified as a pathogenic mechanism in various diseases. However, the role of ferroptosis in the development of liver fibrosis in NASH with type 2 diabetes mellitus (T2DM) is unclear. Here, we observed the histopathological features of the progression of NASH to liver fibrosis as well as hepatocyte epithelial-mesenchymal transition (EMT) in a mouse model of NASH with T2DM and high-glucose-cultured steatotic human normal liver (LO2) cells. The distinctive features of ferroptosis, including iron overload, decreased antioxidant capacity, the accumulation of reactive oxygen species, and elevated lipid peroxidation products, were confirmed in vivo and in vitro. Liver fibrosis and hepatocyte EMT were markedly alleviated after treatment with the ferroptosis inhibitor ferrostatin-1. Furthermore, a decrease in the gene and protein levels of AGE receptor 1 (AGER1) was detected in the transition from NASH to liver fibrosis. Overexpression of AGER1 dramatically reversed hepatocyte EMT in high-glucose-cultured steatotic LO2 cells, whereas the knockdown of AGER1 had the opposite effect. The mechanisms underlying the phenotype appear to be associated with the inhibitory effects of AGER1 on ferroptosis, which is dependent on the regulation of sirtuin 4. Finally, in vivo adeno-associated virus-mediated AGER1 overexpression effectively relieved liver fibrosis in a murine model. Collectively, these findings suggest that ferroptosis participates in the pathogenesis of liver fibrosis in NASH with T2DM by promoting hepatocyte EMT. AGER1 could reverse hepatocyte EMT to ameliorate liver fibrosis by inhibiting ferroptosis. The results also suggest that AGER1 may be a potential therapeutic target for the treatment of liver fibrosis in patients with NASH with T2DM. Chronic hyperglycemia is associated with increased advanced glycation end products, resulting in the downregulation of AGER1. AGER1 deficiency downregulates Sirt4, which disturbs key regulators of ferroptosis (TFR-1, FTH, GPX4, and SLC7A11). These lead to increased iron uptake, decreasing the antioxidative capacity and enhanced lipid ROS production, ultimately leading to ferroptosis, which further promotes hepatocyte epithelial-mesenchymal transition and fibrosis progression in NASH with T2DM.

Endothelial Glycocalyx Preservation-Impact of Nutrition and Lifestyle

The endothelial glycocalyx (eGC) is a dynamic hair-like layer expressed on the apical surface of endothelial cells throughout the vascular system. This layer serves as an endothelial cell gatekeeper by controlling the permeability and adhesion properties of endothelial cells, as well as by controlling vascular resistance through the mediation of vasodilation. Pathogenic destruction of the eGC could be linked to impaired vascular function, as well as several acute and chronic cardiovascular conditions. Defining the precise functions and mechanisms of the eGC is perhaps the limiting factor of the missing link in finding novel treatments for lifestyle-related diseases such as atherosclerosis, type 2 diabetes, hypertension, and metabolic syndrome. However, the relationship between diet, lifestyle, and the preservation of the eGC is an unexplored territory. This article provides an overview of the eGC's importance for health and disease and describes perspectives of nutritional therapy for the prevention of the eGC's pathogenic destruction. It is concluded that vitamin D and omega-3 fatty acid supplementation, as well as healthy dietary patterns such as the Mediterranean diet and the time management of eating, might show promise for preserving eGC health and, thus, the health of the cardiovascular system.

Akt2 deficiency alleviates oxidative stress in the heart and liver via up-regulating SIRT6 during high-fat diet-induced obesity

The present study aims to investigate the role of AKT2 in the pathogenesis of hepatic and cardiac lipotoxicity induced by lipid overload-induced obesity and identify its downstream targets. WT and Akt2 KO mice were fed either normal diet, or high-fat diet (HFD) to induce obesity model in vivo. Human hepatic cell line (L02 cells) and neonatal rat cardiomyocytes (NRCMs) were used as in vitro models. We observed that during HFD-induced obesity, Akt2 loss-of-function mitigated lipid accumulation and oxidative stress in the liver and heart tissue. Mechanistically, down-regulation of Akt2 promotes SIRT6 expression in L02 cells and NRCMs, the latter deacetylates SOD2, which promotes SOD2 activity and therefore alleviates oxidative stress-induced injury of hepatocytes and cardiomyocytes. Furthermore, we also proved that AKT2 inhibitor protects hepatocytes and cardiomyocytes from HFD-induced oxidative stress. Therefore, our work prove that AKT2 plays an important role in the regulation of obesity-induced lipid metabolic disorder in the liver and heart. Our study also indicates AKT2 inhibitor as a potential therapy for obesity-induced hepatic and cardiac injury.

The Role of Natural Antioxidant Products That Optimize Redox Status in the Prevention and Management of Type 2 Diabetes

The worldwide prevalence of type 2 diabetes (T2D) and prediabetes is rapidly increasing, particularly in children, adolescents, and young adults. Oxidative stress (OxS) has emerged as a likely initiating factor in T2D. Natural antioxidant products may act to slow or prevent T2D by multiple mechanisms, i.e., (1) reducing mitochondrial oxidative stress, (2) preventing the damaging effects of lipid peroxidation, and (3) acting as essential cofactors for antioxidant enzymes. Natural antioxidant products should also be evaluated in the context of the complex physiological processes that modulate T2D-OxS such as glycemic control, postprandial OxS, the polyol pathway, high-calorie, high-fat diets, exercise, and sleep. Minimizing processes that induce chronic damaging OxS and maximizing the intake of natural antioxidant products may provide a means of preventing or slowing T2D progression. This "optimal redox" (OptRedox) approach also provides a framework in which to discuss the potential benefits of natural antioxidant products such as vitamin E, vitamin C, beta-carotene, selenium, and manganese. Although there is a consensus that early effective intervention is critical for preventing or reversing T2D progression, most research has focused on adults. It is critical, therefore, that future research include pediatric populations.

Age at diagnosis, diabetes duration and the risk of cardiovascular disease in patients with diabetes mellitus: a cross-sectional study

Background

The purpose of the study was to evaluate characteristics and risk of cardiovascular disease (CVD) according to age at diagnosis and disease duration among adults with diabetes mellitus (DM).

Methods

The association between age at diagnosis, diabetes duration and CVD were examined in 1,765 patients with DM. High risk of estimated ten-year atherosclerotic cardiovascular disease (ASCVD) was performed by the Prediction for ASCVD Risk in China (China-PAR) project. Data were compared with analysis of variance and χ2 test, respectively. Multiple logistic regression was used to determine the risk factors of CVD.

Results

The mean age at diagnosis (± standard deviation) was 52.91 ± 10.25 years and diabetes duration was 8.06 ± 5.66 years. Subjects were divided into early-onset DM group (≤43 years), late-onset DM group (44 to 59 years), elderly-onset DM group (≥60 years) according to age at diagnosis. Diabetes duration was classified by 5 years. Both early-onset and longest diabetes duration (>15 years) had prominent hyperglycaemia. Diabetes duration was associated with the risk of ischemic stroke (odds ratio (OR), 1.091) and coronary artery disease (OR, 1.080). Early-onset group (OR, 2.323), and late-onset group (OR, 5.199), and hypertension (OR, 2.729) were associated with the risk of ischemic stroke. Late-onset group (OR, 5.001), disease duration (OR, 1.080), and hypertension (OR, 2.015) and hyperlipidemia (OR, 1.527) might increase the risk of coronary artery disease. Aged over 65 (OR, 10.192), central obesity (OR, 1.992), hypertension (OR, 18.816), cardiovascular drugs (OR, 5.184), antihypertensive drugs (OR, 2.780), and participants with disease duration >15 years (OR, 1.976) were associated with the high risk of estimated ten-year ASCVD in participants with DM.

Conclusion

Age at diagnosis, diabetes duration, hypertension and hyperlipidemia were independent risks of CVD. Longest (>15 years) diabetes duration increased the high risk of ten-year ASCVD prediction among Chinese patients with DM. It's urgent to emphasize the importance of age at diagnosis and diabetes duration to improve primary complication of diabetes.

The relationship between dietary patterns and ophthalmic disease

PURPOSE OF REVIEW

There is a rising interest in the impact of diet on the pathogenesis of common ophthalmic conditions. The purpose of this review is to summarize the potential preventive and therapeutic power of dietary interventions described in recent basic science and epidemiological literature.

RECENT FINDINGS

Basic science investigations have elucidated a variety of mechanisms by which diet may impact ophthalmic disease, particularly through its action on chronic oxidative stress, inflammation and macular pigmentation. Epidemiologic investigations have shown the real-world influence of diet on the incidence and progression of a number of ophthalmic diseases, particularly cataract, age-related macular degeneration (AMD) and diabetic retinopathy. A large observational cohort study found a 20% reduction in the incidence of cataract among vegetarians compared with nonvegetarians. Two recent systematic reviews found that higher adherence to Mediterranean dietary patterns was associated with a decreased risk of progression of AMD to later stages. Finally, large meta-analyses found that patients following plant-based and Mediterranean diets had significant reductions of mean haemoglobin A1c scores and incidence of diabetic retinopathy as compared with controls.

SUMMARY

There is a significant and growing body of evidence that Mediterranean diet and plant-based diets - those that maximize fruits, vegetables, legumes, whole grains and nuts; and that minimize animal products and processed foods - help prevent vision loss from cataract, AMD and diabetic retinopathy. These diets may hold benefits for other ophthalmic conditions, as well. Nevertheless, there is a need for further randomized, controlled and longitudinal studies in this area.

Anti-Glucotoxicity Effect of Phytoconstituents via Inhibiting MGO-AGEs Formation and Breaking MGO-AGEs

The therapeutic benefits of phytochemicals in the treatment of various illnesses and disorders are well documented. They show significant promise for the discovery and creation of novel medications for treating a variety of human diseases. Numerous phytoconstituents have shown antibiotic, antioxidant, and wound-healing effects in the conventional system. Traditional medicines based on alkaloids, phenolics, tannins, saponins, terpenes, steroids, flavonoids, glycosides, and phytosterols have been in use for a long time and are crucial as alternative treatments. These phytochemical elements are crucial for scavenging free radicals, capturing reactive carbonyl species, changing protein glycation sites, inactivating carbohydrate hydrolases, fighting pathological conditions, and accelerating the healing of wounds. In this review, 221 research papers have been reviewed. This research sought to provide an update on the types and methods of formation of methylglyoxal-advanced glycation end products (MGO-AGEs) and molecular pathways induced by AGEs during the progression of the chronic complications of diabetes and associated diseases as well as to discuss the role of phytoconstituents in MGO scavenging and AGEs breaking. The development and commercialization of functional foods using these natural compounds can provide potential health benefits.

Glucose transporter 4: Insulin response mastermind, glycolysis catalyst and treatment direction for cancer progression

The glucose transporter family (GLUT) consists of fourteen members. It is responsible for glucose homeostasis and glucose transport from the extracellular space to the cell cytoplasm to further cascade catalysis. GLUT proteins are encoded by the solute carrier family 2 (SLC2) genes and are members of the major facilitator superfamily of membrane transporters. Moreover, different GLUTs also have their transporter kinetics and distribution, so each GLUT member has its uniqueness and importance to play essential roles in human physiology. Evidence from many studies in the field of diabetes showed that GLUT4 travels between the plasma membrane and intracellular vesicles (GLUT4-storage vesicles, GSVs) and that the PI3K/Akt pathway regulates this activity in an insulin-dependent manner or by the AMPK pathway in response to muscle contraction. Moreover, some published results also pointed out that GLUT4 mediates insulin-dependent glucose uptake. Thus, dysfunction of GLUT4 can induce insulin resistance, metabolic reprogramming in diverse chronic diseases, inflammation, and cancer. In addition to the relationship between GLUT4 and insulin response, recent studies also referred to the potential upstream transcription factors that can bind to the promoter region of GLUT4 to regulating downstream signals. Combined all of the evidence, we conclude that GLUT4 has shown valuable unknown functions and is of clinical significance in cancers, which deserves our in-depth discussion and design compounds by structure basis to achieve therapeutic effects. Thus, we intend to write up a most updated review manuscript to include the most recent and critical research findings elucidating how and why GLUT4 plays an essential role in carcinogenesis, which may have broad interests and impacts on this field.

Phytochemical profile and antioxidant capacity, α-amylase and α-glucosidase inhibitory activities of Oxalis pes-caprae extracts in alloxan-induced diabetic mice

Diabetes and its complications are closely correlated with chronic hyperglycemia, causing severe oxidative stress and leading to glycation reaction with formation of advanced glycation end products. However, medicinal plants are still a source of inspiration for the discovery of new treatments of several diseases, including diabetes. The present study was aimed to evaluate the antioxidant and antidiabetic properties of Oxalis pes-caprae flowers extract in alloxan-induced diabetic mice. The phytochemical and antioxidant activities of both aqueous and methanolic extracts were assessed by in-vitro testing such as free radical scavenging assays (DPPH and ABTS⁺), ferrous ions (Fe²⁺) chelating activity and reducing power assay. Additionally, the detection of Amadori products and advanced glycation end products was used to determine the antiglycation potential. α-glucosidase and α-amylase inhibitory assessment was employed to determine the antidiabetic effect, while alloxan-induced diabetic mice were used to measure the in-vivo activities of antioxidants and carbohydrates enzymes. The effect of the methanolic extract on body weight and blood glucose level of extract-treated diabetic mice were also investigated. Among the tested extract, the methanolic extract was the richest in phenolic compounds which is directly related with their remarkable antioxidant, enzyme inhibitory and antiglycation activity. The oral administration of the two doses of Oxalis pes-caprae flowers (150 mg/kg and 250 mg/kg) daily for 3 weeks resulted in hypoglycemic effect compared to the reference drug, glibenclamide (10 mg/kg). Furthermore, the extract was shown to significantly increase the activities of antioxidants and glycolysis enzymes in the liver, kidney and spleen of diabetic mice, compared to diabetic control group. Therefore, Oxalis pes-caprae extract effectively exhibited hypoglycemic and antidiabetic effects as indicated by in-vitro and in-vivo studies, confirming the protective effects on hyperglycemia and oxidative damage.

Rutin impedes human low-density lipoprotein from non-enzymatic glycation: A mechanistic insight against diabetes-related disorders

Glycation of human low-density protein (LDL) has an essential contribution to cardiovascular diseases. Natural compounds like rutin have been extensively studied in preventing glycation-induced oxidative stress. This study examined rutin's anti-glycation potential with glycated LDL utilizing spectroscopic and in silico methods. Glycated LDL treated with rutin, showed around 80 % inhibition in advanced glycation end-product production. Carbonyl content and lipid peroxidation like assays were used to establish the development of oxidative stress. Rutin was seen to lower the generation of oxidative stress in a dose-dependent manner. Using thioflavin t-test and electron microscopy, rutin was suggested to restore the structural disturbances in glycated LDL. Moreover, CD spectroscopy suggested reinstation of secondary structure of glycated LDL treated with rutin. Mechanistic insights between rutin and LDL were observed through spectroscopic measures. Molecular docking study confirmed the LDL-rutin binding with a binding energy of -10.0 kcal/mol. The rutin-LDL complex was revealed to be highly stable by molecular dynamics simulation, with RMSD, RMSF, Rg, SASA, and the secondary structure of LDL remaining essentially unchanged during the simulation period. Our study suggests that rutin possesses strong anti-glycating properties, which can be useful in therapeutics, as glycated LDL has an important role in atherosclerotic cardiovascular diseases.

Advanced glycation end products induce skeletal muscle atrophy and insulin resistance via activating ROS-mediated ER stress PERK/FOXO1 signaling

Skeletal muscle atrophy is often found in patients with type 2 diabetes mellitus (T2DM), which is characterized by insulin resistance. As the largest tissue in the body, skeletal muscle plays important roles in insulin resistance. Advanced glycation end products (AGEs) are a type of toxic metabolite that are representative of multiple pathophysiological changes associated with T2DM. Mice were exposed to AGEs. Forkhead box O1 (FOXO1) was silenced by using a constructed viral vector carrying siRNA. Skeletal muscle atrophy was evaluated by using hematoxylin-eosin (H&E), oil red O, myosin skeletal heavy chain (MHC), and laminin immunofluorescent stains. Reactive oxygen species (ROS) generation was assessed by using the dihydroethidium (DHE) stain. Western blotting was used to evaluate protein expression and phosphorylation. Insulin resistance was monitored via the insulin tolerance test and the glucose infusion rate (GIR). Mice exposed to AGEs showed insulin resistance, which was evidenced by reduced insulin tolerance and GIR. H&E and MHC immunofluorescent stains suggested reduced cross-sectional muscle fiber area. Laminin immunofluorescent and oil red O stains indicated increased intramuscular fibrosis and lipid deposits, respectively. Exposure to AGEs induced ROS generation, increased phosphorylation of protein kinase RNA-like endoplasmic reticulum kinase (PERK) and FOXO1, facilitated FOXO1 nuclear translocation, and elevated expression of muscle atrophy F-box (MAFbx) in gastrocnemius muscle. foxo1 silencing significantly suppressed skeletal muscle atrophy and insulin resistance without affecting ROS production. AGEs exacerbated skeletal muscle atrophy and insulin resistance by activating the PERK/FOXO1 signaling pathway in skeletal muscle.NEW & NOTEWORTHY In this study, we proposed a molecular mechanism underlying the skeletal muscle atrophy-associated insulin resistance in type 2 diabetes mellitus (T2DM). Our investigation suggests that exposure to AGEs, which are characteristic metabolites of T2DM pathology, induces the activation of reactive oxygen species (ROS)-mediated endoplasmic reticulum (ER) stress, leading to the upregulation of the protein kinase RNA-like ER kinase (PERK)/forkhead box O1 (FOXO1)/muscle atrophy F-box pathway and subsequent skeletal muscle atrophy, ultimately resulting in insulin resistance.

The Effect on Inflammation of Adherence to the Mediterranean Diet in Polycystic Ovary Syndrome

PURPOSE OF REVIEW

Polycystic ovary syndrome (PCOS), which is common in women of reproductive age worldwide, is a syndrome that reduces the lifelong quality of life and poses a significant risk for various diseases. PCOS is a combination of symptoms of hyperandrogenism, oligo-anovulation, and polycystic ovarian morphology (PCOM). In PCOS, which is characterized by chronic low-grade inflammation, some inflammatory cytokines are increased. This review aimed to explain possible mechanisms of inflammation in PCOS and the effects of Mediterranean diet components on reducing this inflammation.

RECENT FINDINGS

Although the exact mechanisms of inflammation in PCOS are not yet fully known, it is stated that it is mediated by obesity, insulin resistance, and high androgen concentration. This inflammatory state negatively impacts the risk of future health problems and the quality of life of PCOS. Therefore, strategies to reduce inflammation are thought to be important. Dietary adjustments have important effects in reducing this inflammation and preventing disease. At this point, the Mediterranean diet, which has been proven to have a protective effect against many diseases, draws attention. Among the components of the Mediterranean diet, especially omega-3, antioxidants and dietary fiber may contribute to the reduction of inflammation through different mechanisms. PCOS is characterized by chronic low-grade inflammation, which increases women's risk of health problems, both now and in the future. Reducing inflammation is therefore extremely important, and it can be achieved with adherence to the Mediterranean diet. Inflammation pathways and the effect of the components of the Mediterranean diet in PCOS. AGE, advanced glycation end products; NF-κB, nuclear factor kappa-B. Obesity, insulin resistance, and hyperandrogenism may cause inflammation in PCOS through different mechanisms. Antioxidants, omega-3, and dietary fiber, which are the main components of the Mediterranean diet, may be effective in reducing this inflammation in PCOS. (Created with BioRender.com).

Sulfathiazole treats type 2 diabetes by restoring metabolism through activating CYP19A1

Globally, diabetes mellitus has been a major epidemic bringing metabolic and endocrine disorders. Currently, 1 in 11 adults suffers from diabetes mellitus, among the patients >90% contract type 2 diabetes mellitus (T2DM). Therefore, it is urgent to develop new drugs that effectively prevent and treat type 2 diabetes through new targets. With high-throughput screening, we found that sulfathiazole decreased the blood glucose and improved glucose metabolism in T2DM mice. Notably, we discovered that sulfathiazole treated T2DM by activating CYP19A1 protein to synthesize estrogen. Collectively, sulfathiazole along with CYP19A1 target bring new promise for the better therapy of T2DM.

In vitro glycation of a tissue-engineered wound healing model to mimic diabetic ulcers

Diabetic foot ulcers are a major complication of diabetes that occurs following minor trauma. Diabetes-induced hyperglycemia is a leading factor inducing ulcer formation and manifests notably through the accumulation of advanced glycation end-products (AGEs) such as N-carboxymethyl-lysin. AGEs have a negative impact on angiogenesis, innervation, and reepithelialization causing minor wounds to evolve into chronic ulcers which increases the risks of lower limb amputation. However, the impact of AGEs on wound healing is difficult to model (both in vitro on cells, and in vivo in animals) because it involves a long-term toxic effect. We have developed a tissue-engineered wound healing model made of human keratinocytes, fibroblasts, and endothelial cells cultured in a collagen sponge biomaterial. To mimic the deleterious effects induced by glycation on skin wound healing, the model was treated with 300 µM of glyoxal for 15 days to promote AGEs formation. Glyoxal treatment induced carboxymethyl-lysin accumulation and delayed wound closure in the skin mimicking diabetic ulcers. Moreover, this effect was reversed by the addition of aminoguanidine, an inhibitor of AGEs formation. This in vitro diabetic wound healing model could be a great tool for the screening of new molecules to improve the treatment of diabetic ulcers by preventing glycation.

High glucose leads to redistribution of the proteasomal system

The impact of high glucose on the cellular redox state, causing both induction of antioxidative systems and also enhanced protein oxidation is discussed for a long time. It is established that elevated glucose levels are disrupting the cellular proteostasis and influencing the proteasomal system. However, it is still unresolved whether this is due to a reaction of the cellular proteasomal system towards the high glucose or whether this is a secondary reaction to inflammatory stimuli. Therefore, we used a dermal fibroblast cell line exposed to high glucose in order to reveal whether a response of the proteasomal system takes place. We investigated the α4 and the inducible iβ5 subunits of the 20S proteasome, as well as the Rpn1-subunit of the 19S proteasomal regulator complex, measured activity of the 20S, 20S1, and 26S proteasome and detected as well changes in expression as a redistribution into the nucleus. Interestingly, while the activity of the proteasomal forms rather decreased under high glucose treatment; higher expression levels of components of the proteasomal system and higher concentrations of protein-bound 3-nitrotyrosine and Nrf2 (nuclear factor [erythroid-derived 2]-like 2) were detected. However, no change in the cytosol-nucleus distribution could be detected for most of the quantified parameters. We concluded that high glucose alone, without additional inflammatory stimuli, provokes a regulatory response on the ubiquitin-proteasomal system.

Association between type II diabetes mellitus and 90-day mortality in a large multicenter prospectively collected cohort. A FROG ICU post-hoc study

PURPOSE

Factors associated with adverse outcomes in ICU patients with type II (T2DM) are poorly defined. The main goal of this study is to determine the impact of pre-existing T2DM on 90-day mortality post ICU admission.

MATERIAL

Post-hoc analysis from the FROG-ICU cohort. All patients admitted to ICU who were ventilated and/or treated by a vasoactive agent for >24 h were included. Association between T2DM and 90-day mortality was analyzed in unmatched, and populations matched by propensity score (PS) method to balance confounders recorded before ICU admission. Analysis was performed in non-imputed and imputed datasets.

RESULTS

2002 patients were included, and 16% had a history of T2DM. The latter were at inclusion more severely ill (SAPSII score 51(39-67) vs 48(35-61), p < 0.0001; Charlson score 2(1-3) vs 0(0-2), p < 0.0001). In the unmatched cohort, T2DM patients had a higher 90-day risk of death compared to no-DM patients (HR 1.35(1.1-1.65)). The 90-day risk of death was not significantly different T2DM and no T2DM patients after PS matching (HR: 0.81 (0.56-1.18). Results were similar with the analysis performed on imputed datasets (pooled HR: 0.95 (0.69-1.30)).

CONCLUSIONS

In the present study, T2DM was not associated with 90-day mortality post ICU admission.

Potential roles of ellagic acid on metabolic variables in diabetes mellitus: A systematic review

Diabetes mellitus is a widespread endocrine disorder globally. Due to its antioxidant and anti-inflammatory properties, ellagic acid has the potential to improve the metabolic effects of chronic non-communicable diseases. This systematic review summarizes current evidence about the potential effects of ellagic acid on metabolic variables in diabetes mellitus. A comprehensive systematic literature search was conducted in databases such as PubMed, Scopus, EMBASE, ProQuest and Google Scholar from inception until March 2022. All animal studies and clinical trials were eligible for inclusion. Studies using in vitro models or published in a non-English language were excluded. Of 1320 articles, 23 were selected for assessment, including 21 animal studies and two randomized controlled trial studies. Following ellagic acid administration, findings reported improvement in FBS, HbA1c, insulin (20, 8 and 12 studies, respectively), TG, TC, HDL-C (13, 10 and 5 studies, respectively), MDA, GSH, CAT, SOD (11, 6, 3 and 4 studies, respectively), and TNF-α and IL-6 (6 and 3 studies, respectively). In conclusion, ellagic acid may improve glycaemic indicators, dyslipidaemia, oxidative stress and inflammation in diabetes mellitus. However, further clinical trials are needed to explore the mechanisms more precisely and to observe the applied consequences.

Exercise Restores Hypothalamic Health in Obesity by Reshaping the Inflammatory Network

Obesity and overnutrition induce inflammation, leptin-, and insulin resistance in the hypothalamus. The mediobasal hypothalamus responds to exercise enabling critical adaptions at molecular and cellular level that positively impact local inflammation. This review discusses the positive effect of exercise on obesity-induced hypothalamic dysfunction, highlighting the mechanistic aspects related to the anti-inflammatory effects of exercise. In HFD-fed animals, both acute and chronic moderate-intensity exercise mitigate microgliosis and lower inflammation in the arcuate nucleus (ARC). Notably, this associates with restored leptin sensitivity and lower food intake. Exercise-induced cytokines IL-6 and IL-10 mediate part of these positive effect on the ARC in obese animals. The reduction of obesity-associated pro-inflammatory mediators (e.g., FFAs, TNFα, resistin, and AGEs), and the improvement in the gut-brain axis represent alternative paths through which regular exercise can mitigate hypothalamic inflammation. These findings suggest that the regular practice of exercise can restore a proper functionality in the hypothalamus in obesity. Further analysis investigating the crosstalk muscle-hypothalamus would help toward a deeper comprehension of the subject.

Glycation of LDL: AGEs, impact on lipoprotein function, and involvement in atherosclerosis

Atherosclerosis is a complex disease, and there are many factors that influence its development and the course of the disease. A deep understanding of the pathological mechanisms underlying atherogenesis is needed to develop optimal therapeutic strategies and treatments. In this review, we have focused on low density lipoproteins. According to multiple studies, their atherogenic properties are associated with multiple modifications of lipid particles. One of these modifications is Glycation. We considered aspects related to the formation of modified particles, as well as the influence of modification on their functioning. We paid special attention to atherogenicity and the role of glycated low-density lipoprotein (LDL) in atherosclerosis.

The Association between the Level of Advanced Glycation End Products and Objective Skin Quality Parameters

Advanced glycation end products (AGEs) represent an endogenously produced or exogenously derived group of compounds derived from nonenzymatic glycation. Recent experimental studies are suggesting that AGEs could play an important role in the skin's quality and its aging process. Hence, the aim of this study was to clinically evaluate the AGEs and skin quality parameters across different age groups in the general population. The study included 237 participants. Melanin, erythema, hydration, friction and transepidermal water loss (TEWL) were evaluated using noninvasive probes, while AGEs were evaluated using a skin autofluorescence reader. There was a significant positive correlation between AGEs and the amount of melanin (p < 0.001), erythema (p < 0.001) and TEWL (p < 0.001), while there was a significant negative correlation between AGEs and hydration (p < 0.001) and friction (p < 0.001). After dividing the sample into three groups depending on their age, in all three groups, there was a significant positive correlation between AGEs and the melanin count (p < 0.001) and TEWL (p < 0.001), while there was a significant negative correlation between AGEs and skin hydration (p < 0.001). Multiple linear regression analysis showed that the level of AGEs as a dependent variable retained a significant association with age (p < 0.001), melanin (p < 0.001), erythema (p = 0.005) and TEWL (p < 0.001) as positive predictors. Moreover, AGEs retained a significant association with skin hydration (p < 0.001) and friction (p = 0.017) as negative predictors. These outcomes imply that AGEs could be linked with the complex physiology of the skin and its aging process.

Advanced Glycation End-Products and Their Effects on Gut Health

Dietary advanced glycation end-products (AGEs) are a heterogeneous group of compounds formed when reducing sugars are heated with proteins, amino acids, or lipids at high temperatures for a prolonged period. The presence and accumulation of AGEs in numerous cell types and tissues are known to be prevalent in the pathology of many diseases. Modern diets, which contain a high proportion of processed foods and therefore a high level of AGE, cause deleterious effects leading to a multitude of unregulated intracellular and extracellular signalling and inflammatory pathways. Currently, many studies focus on investigating the chemical and structural aspects of AGEs and how they affect the metabolism and the cardiovascular and renal systems. Studies have also shown that AGEs affect the digestive system. However, there is no complete picture of the implication of AGEs in this area. The gastrointestinal tract is not only the first and principal site for the digestion and absorption of dietary AGEs but also one of the most susceptible organs to AGEs, which may exert many local and systemic effects. In this review, we summarise the current evidence of the association between a high-AGE diet and poor health outcomes, with a special focus on the relationship between dietary AGEs and alterations in the gastrointestinal structure, modifications in enteric neurons, and microbiota reshaping.

Endothelial senescence in vascular diseases: current understanding and future opportunities in senotherapeutics

Senescence compromises the essential role that the endothelium plays in maintaining vascular homeostasis, so promoting endothelial dysfunction and the development of age-related vascular diseases. Their biological and clinical significance calls for strategies for identifying and therapeutically targeting senescent endothelial cells. While senescence and endothelial dysfunction have been studied extensively, distinguishing what is distinctly endothelial senescence remains a barrier to overcome for an effective approach to addressing it. Here, we review the mechanisms underlying endothelial senescence and the evidence for its clinical importance. Furthermore, we discuss the current state and the limitations in the approaches for the detection and therapeutic intervention of target cells, suggesting potential directions for future research.

Cathepsin D Attenuates the Proliferation of Vascular Smooth Muscle Cells Induced by the AGE/RAGE Pathway by Suppressing the ERK Signal

BACKGROUND

In this study, we aimed to clarify the role and mechanism by which Cathepsin D (CTSD) mediates the advanced glycation end products (AGEs)-induced proliferation of vascular smooth muscle cells (VSMCs).

METHODS

We conducted a Western blotting assay and co-immunoprecipitation assay to detect the expression of target proteins and the interaction between different proteins. Cell Counting Kit-8 (CCK-8) assay and 5- ethynyl-2'-deoxyuridine (EdU) were used to evaluate the proliferation.

RESULTS

AGEs significantly promoted phenotypic switching and proliferation of VSMCs in a concentration-dependent manner. This effect of AGEs was accompanied by inhibition of CTSD. Both the proliferation of VSMCs and inhibition of CTSD induced by AGEs could be attenuated by the specific inhibitor of the receptor for advanced glycation end products (RAGE), FPS-ZM1. Overexpression of CTSD significantly alleviated these effects of AGEs on VSMCs. The mechanism of CTSD action in VSMCs was also explored. Overexpression of CTSD reduced the activation of p-ERK caused by AGEs. By contrast, the knockdown of CTSD, elicited using a plasmid containing short hairpin RNA (shRNA) against CTSD, further increased the activation of p-ERK compared to AGEs alone. Additionally, co-immunoprecipitation studies revealed an endogenous interaction between CTSD, a protease, and p-ERK, its potential substrate.

CONCLUSION

It has been demonstrated that CTSD downregulates the level of phosphorylated ERK by degrading its target, and this interaction plays a critical role in the proliferation of VSMCs induced by the AGE/RAGE axis. These results provide a novel insight into the prevention and treatment of vascular complications in diabetes.