Advanced Glycation End Products and Diabetes Mellitus: Mechanisms and Perspectives

Integrated approach to reducing polypharmacy in older people: exploring the role of oxidative stress and antioxidant potential therapy

Increased life expectancy, attributed to improved access to healthcare and drug development, has led to an increase in multimorbidity, a key contributor to polypharmacy. Polypharmacy is characterised by its association with a variety of adverse events in the older persons. The mechanisms involved in the development of age-related chronic diseases are largely unknown; however, altered redox homeostasis due to ageing is one of the main theories. In this context, the present review explores the development and interaction between different age-related diseases, mainly linked by oxidative stress. In addition, drug interactions in the treatment of various diseases are described, emphasising that the holistic management of older people and their pathologies should prevail over the individual treatment of each condition.

Deciphering the inhibitory mechanisms of betanin and phyllocactin from Hylocereus polyrhizus peel on protein glycation, with insights into their application in bread

Protein glycation closely intertwines with the pathogenesis of various diseases, sparking a growing interest in exploring natural antiglycation agents. Herein, high-purity betacyanins (betanin and phyllocactin) derived from Hylocereus polyrhizus peel were studied for their antiglycation potential using an in vitro bovine serum albumin (BSA)-glucose model. Notably, betacyanins outperformed aminoguanidine, a recognized antiglycation agent, in inhibiting glycation product formation across different stages, especially advanced glycation end-products (AGEs). Interestingly, phyllocactin displayed stronger antiglycation activity than betanin. Subsequent mechanistic studies employing molecular docking analysis and fluorescence quenching assay unveiled that betacyanins interact with BSA endothermically and spontaneously, with hydrophobic forces playing a dominant role. Remarkably, phyllocactin demonstrated higher binding affinity and stability to BSA than betanin. Furthermore, the incorporation of betacyanins into bread dose-dependently suppressed AGEs formation during baking and shows promise for inhibiting in vivo glycation process post-consumption. Overall, this study highlights the substantial potential of betacyanins as natural antiglycation agents.

Insight into the Effect of Methylglyoxal on the Conformation, Function, and Aggregation Propensity of α-Synuclein

It is well-known that people suffering from hyperglycemia have a higher propensity to develop Parkinson's disease (PD). One of the most plausible mechanisms linking these two pathologies is the glycation of neuronal proteins and the pathological consequences of it. α-Synuclein, a key component in PD, can be glycated at its fifteen lysine. In fact, the end products of this process have been detected on aggregated α-synuclein isolated from in vivo. However, the consequences of glycation are not entirely clear, which are of crucial importance to understand the mechanism underlying the connection between diabetes and PD. To better clarify this, we have here examined how methylglyoxal (the most important carbonyl compound found in the cytoplasm) affects the conformation and aggregation propensity of α-synuclein, as well as its ability to cluster and fuse synaptic-like vesicles. The obtained data prove that methylglyoxal induces the Lys-Lys crosslinking through the formation of MOLD. However, this does not have a remarkable effect on the averaged conformational ensemble of α-synuclein, although it completely depletes its native propensity to form soluble oligomers and insoluble amyloid fibrils. Moreover, methylglyoxal has a disrupting effect on the ability of α-synuclein to bind, cluster and fusion synaptic-like vesicles.

Novel Properties of Old Propranolol-Assessment of Antiglycation Activity through In Vitro and In Silico Approaches

Hypertension has earned the "silent killer" nickname since it may lead to a number of comorbidities, including diabetes and cardiovascular diseases. Oxidative stress and protein glycation play vital roles in the pathogenesis of hypertension. Several studies have shown that they profoundly account for vascular dysfunction, endothelial damage, and disruption of blood pressure regulatory mechanisms. Of particular note are advanced glycation end products (AGEs). AGEs alter vascular tissues' functional and mechanical properties by binding to receptors for advanced glycation end products (RAGE), stimulating inflammation and free radical-mediated pathways. Propranolol, a nonselective beta-adrenergic receptor antagonist, is one of the most commonly used drugs to treat hypertension and cardiovascular diseases. Our study is the first to analyze propranolol's effects on protein glycoxidation through in vitro and in silico approaches. Bovine serum albumin (BSA) was utilized to evaluate glycoxidation inhibition by propranolol. Propranolol (1 mM) and BSA (0.09 mM) were incubated with different glycating (0.5 M glucose, fructose, and galactose for 6 days and 2.5 mM glyoxal and methylglyoxal for 12 h) or oxidizing agents (chloramine T for 1 h). Biomarkers of protein glycation (Amadori products (APs), β-amyloid (βA), and advanced glycation end products (AGEs)), protein glycoxidation (dityrosine (DT), kynurenine (KYN), and N-formylkynurenine (NFK)), protein oxidation (protein carbonyls (PCs), and advanced oxidation protein products (AOPPs)) were measured by means of colorimetric and fluorimetric methods. The scavenging of reactive oxygen species (hydrogen peroxide, hydroxyl radical, and nitric oxide) and the antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl radical and ferrous ion chelating (FIC) assays)) of propranolol were also evaluated. Additionally, in silico docking was performed to showcase propranolol's interaction with BSA, glycosides, and AGE/RAGE pathway proteins. The products of protein glycation (↓APs, ↓βA, ↓AGEs), glycoxidation (↓DT, ↓KYN, ↓NFK), and oxidation (↓PCs, ↓AOPPs) prominently decreased in the BSA samples with both glycating/oxidizing factors and propranolol. The antiglycoxidant properties of propranolol were similar to those of aminoguanidine, a known protein oxidation inhibitor, and captopril, which is an established antioxidant. Propranolol showed a potent antioxidant activity in the FIC and H2O2 scavenging assays, comparable to aminoguanidine and captopril. In silico analysis indicated propranolol's antiglycative properties during its interaction with BSA, glycosidases, and AGE/RAGE pathway proteins. Our results confirm that propranolol may decrease protein oxidation and glycoxidation in vitro. Additional studies on human and animal models are vital for in vivo verification of propranolol's antiglycation activity, as this discovery might hold the key to the prevention of diabetic complications among cardiology-burdened patients.

Activation and modulation of the AGEs-RAGE axis: Implications for inflammatory pathologies and therapeutic interventions - A review

Chronic inflammation is a common foundation for the development of many non-communicable diseases, particularly diabetes, atherosclerosis, and tumors. The activation of the axis involving Advanced Glycation End products (AGEs) and their receptor RAGE is a key promotive factor in the chronic inflammation process, influencing the pathological progression of these diseases. The accumulation of AGEs in the body results from an increase in glycation reactions and oxidative stress, especially pronounced in individuals with diabetes. By binding to RAGE, AGEs activate signaling pathways such as NF-κB, promoting the release of inflammatory factors, exacerbating cell damage and inflammation, and further advancing the formation of atherosclerotic plaques and tumor development. This review will delve into the molecular mechanisms by which the AGEs-RAGE axis activates chronic inflammation in the aforementioned diseases, as well as strategies to inhibit the AGEs-RAGE axis, aiming to slow or halt the progression of chronic inflammation and related diseases. This includes the development of AGEs inhibitors, RAGE antagonists, and interventions targeting upstream and downstream signaling pathways. Additionally, the early detection of AGEs levels and RAGE expression as biomarkers provides new avenues for the prevention and treatment of diabetes, atherosclerosis, and tumors.

Lactate drives epithelial-mesenchymal transition in diabetic kidney disease via the H3K14la/KLF5 pathway

High levels of urinary lactate are an increased risk of progression in patients with diabetic kidney disease (DKD). However, it is still unveiled how lactate drive DKD. Epithelial-mesenchymal transition (EMT), which is characterized by the loss of epithelial cells polarity and cell-cell adhesion, and the acquisition of mesenchymal-like phenotypes, is widely recognized a critical contributor to DKD. Here, we found a switch from oxidative phosphorylation (OXPHOS) toward glycolysis in AGEs-induced renal tubular epithelial cells, thus leading to elevated levels of renal lactic acid. We demonstrated that reducing the lactate levels markedly delayed EMT progression and improved renal tubular fibrosis in DKD. Mechanically, we observed lactate increased the levels of histone H3 lysine 14 lactylation (H3K14la) in DKD. ChIP-seq & RNA-seq results showed histone lactylation contributed to EMT process by facilitating KLF5 expression. Moreover, KLF5 recognized the promotor of cdh1 and inhibited its transcription, which accelerated EMT of DKD. Additionally, nephro-specific knockdown and pharmacological inhibition of KLF5 diminished EMT development and attenuated DKD fibrosis. Thus, our study provides better understanding of epigenetic regulation of DKD pathogenesis, and new therapeutic strategy for DKD by disruption of the lactate-drived H3K14la/KLF5 pathway.

Dynamic changes in key factors of the blood-brain barrier in early diabetic mice

Chronic hyperglycemia can result in damage to the hippocampus and dysfunction of the blood-brain barrier (BBB), potentially leading to neurological disorders. This study examined the histological structure of the hippocampus and the expression of critical genes associated with the BBB at 2 early stage time points in a streptozotocin-induced diabetes mellitus (DM) mouse model. Routine histology revealed vascular congestion and dilation of Virchow-Robin spaces in the hippocampal CA1 region of the DM group. Neuronal alterations included rounding and swelling and reduction in Nissl bodies and increased apoptosis. Compared to the control group, TJP1 mRNA expression in the DM group was significantly lower (P < .05 or P < .01), while mRNA levels of JAM3, TJP3, CLDN5, CLDN3, and OCLN initially increased and then decreased. At 7, 14, and 21 days, mRNA levels of the receptor for advanced glycation end products (AGER) were greater in the DM group than in the control group (P < .05 or P < .01). These findings indicate that early-stage diabetes may cause structural and functional impairments in hippocampal CA1 in mice. These abnormalities may parallel alterations in the expression of key BBB tight junction molecules and elevated AGER expression in early DM patients.

Human Periodontal Ligament Stem Cells (hPDLSCs) Spontaneously Differentiate into Myofibroblasts to Repair Diabetic Wounds

Advanced glycation end product (AGE) accumulation due to diabetes causes vascular and neurological lesions, delaying healing. The use of stem cells could overcome these problems. Although many studies have shown the potential beneficial effects of stem cell therapies in the treatment of chronic and refractory skin ulcers, their delivery methods are still under investigation. Human periodontal ligament stem cells (hPDLSCs) can spontaneously differentiate into myofibroblasts in specific cultures; therefore, they have the potential to effectively treat diabetic wounds and may also have applications in the field of medical cosmetics. The myofibroblastic differentiation ability of hPDLSCs in the presence of AGEs was evaluated by the expression of α-SMA and COL1A1 using RT-qPCR and WB technology. Wound healing in diabetic mice, induced by streptozotocin (STZ) and assessed using H&E staining, Masson staining, and immunohistochemical (IHC) and immunofluorescence (IF) staining, was used to validate the effects of hPDLSCs. In the wound tissues, the expression of α-SMA, COL1A1, CD31, CD206, iNOS, and vimentin was detected. The findings indicated that in H-DMEM, the expression of COL1A1 exhibited a significant decrease, while α-SMA demonstrated an increase in P7 cells, ignoring the damage from AGEs (p < 0.05). In an STZ-induced diabetic C57BL/6J mice whole-skin defect model, the healing rate of the hPDLSCs treatment group was significantly higher than that in the models (on the 7th day, the rate was 65.247% vs. 48.938%, p < 0.05). hPDLSCs have been shown to spontaneously differentiate into myofibroblasts in H-DMEM and resist damage from AGEs in both in vivo and in vitro models, suggesting their potential in the field of cosmetic dermatology.

Plant foods, healthy plant-based diets, and type 2 diabetes: a review of the evidence

Type 2 diabetes (T2D) is a metabolic chronic disease in which insulin resistance and insufficient insulin production lead to elevated blood glucose levels. The prevalence of T2D is growing worldwide, mainly due to obesity and the adoption of Western diets. Replacing animal foods with healthy plant foods is associated with a lower risk of T2D in prospective studies. In randomized controlled trials, the consumption of healthy plant foods in place of animal foods led to cardiometabolic improvements in patients with T2D or who were at high risk of the disease. Dietary patterns that limit or exclude animal foods and focus on healthy plant foods (eg, fruits, vegetables, whole grains, nuts, legumes), known as healthy, plant-based diets, are consistently associated with a lower risk of T2D in cohort studies. The aim of this review is to examine the differential effects of plant foods and animal foods on T2D risk and to describe the existing literature about the role of healthy, plant-based diets, particularly healthy vegan diets, in T2D prevention and management. The evidence from cohort studies and randomized controlled trials will be reported, in addition to the potential biological mechanisms that seem to be involved.

Ge-Gen-Qin-Lian decoction alleviates the symptoms of type 2 diabetes mellitus with inflammatory bowel disease via regulating the AGE-RAGE pathway

BACKGROUND

This study aimed to explore the mechanism of Ge-Gen-Qin-Lian decoction (GGQLD) in the alleviation of symptoms of type 2 diabetes mellitus (T2DM) with inflammatory bowel disease (IBD) by network pharmacology and experimental validation.

METHODS

The active components and targets of GGQLD were identified from the TCMSP database. The potential therapeutic targets of T2DM and IBD were identified from the GEO database and 4 online disease target databases. The PPI network and KEGG/GO analyses were performed with the common targets among GGQLD, T2DM and IBD. Molecular docking was carried out between the core compounds and hub targets. To verify the above results, UHPLC-MS technology was used to identify the chemical compounds in GGQLD, and a T2DM with IBD rat model was used to explore the mechanism by which GGQLD treats T2DM with IBD.

RESULTS

Totally, 70 potential therapeutic targets were identified among GGQLD, T2DM and IBD. Ten hub genes were selected from the PPI network. KEGG analysis revealed that GGQLD is tightly involved in the AGE-RAGE signaling pathway. Berberine, baicalein, wogonin, and quercitrin are the main active compounds of GGQLD. Animal experiments showed that GGQLD could decrease blood glucose and alleviate intestinal inflammation. Notably, the concentrations of AGEs, the expression of RAGE, c-JUN and NF-κB and the expression of inflammatory cytokines were decreased by GGQLD.

CONCLUSIONS

Our study initially demonstrated that GGQLD has favorable anti-hyperglycemic and anti-intestinal inflammation effects in a T2DM with IBD rat model, and the AGE-RAGE pathway plays a vital role in this process.

Prediction models for amputation after diabetic foot: systematic review and critical appraisal

BACKGROUND

Numerous studies have developed or validated prediction models aimed at estimating the likelihood of amputation in diabetic foot (DF) patients. However, the quality and applicability of these models in clinical practice and future research remain uncertain. This study conducts a systematic review and assessment of the risk of bias and applicability of amputation prediction models among individuals with DF.

METHODS

A comprehensive search was conducted across multiple databases, including PubMed, Web of Science, EBSCO CINAHL Plus, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, Chinese Biomedical Literature Database (CBM), and Weipu (VIP) from their inception to December 24, 2023. Two investigators independently screened the literature and extracted data using the checklist for critical appraisal and data extraction for systematic reviews of prediction modeling studies. The Prediction Model Risk of Bias Assessment Tool (PROBAST) checklist was employed to evaluate both the risk of bias and applicability.

RESULTS

A total of 20 studies were included in this analysis, comprising 17 development studies and three validation studies, encompassing 20 prediction models and 11 classification systems. The incidence of amputation in patients with DF ranged from 5.9 to 58.5%. Machine learning-based methods were employed in more than half of the studies. The reported area under the curve (AUC) varied from 0.560 to 0.939. Independent predictors consistently identified by multivariate models included age, gender, HbA1c, hemoglobin, white blood cell count, low-density lipoprotein cholesterol, diabetes duration, and Wagner's Classification. All studies were found to exhibit a high risk of bias, primarily attributed to inadequate handling of outcome events and missing data, lack of model performance assessment, and overfitting.

CONCLUSIONS

The assessment using PROBAST revealed a notable risk of bias in the existing prediction models for amputation in patients with DF. It is imperative for future studies to concentrate on enhancing the robustness of current prediction models or constructing new models with stringent methodologies.

Current Prognostic Biomarkers for Abdominal Aortic Aneurysm: A Comprehensive Scoping Review of the Literature

Abdominal aortic aneurysm (AAA) is a progressive dilatation of the aorta that can lead to aortic rupture. The pathophysiology of the disease is not well characterized but is known to be caused by the general breakdown of the extracellular matrix within the aortic wall. In this comprehensive literature review, all current research on proteins that have been investigated for their potential prognostic capabilities in patients with AAA was included. A total of 45 proteins were found to be potential prognostic biomarkers for AAA, predicting incidence of AAA, AAA rupture, AAA growth, endoleak, and post-surgical mortality. The 45 proteins fell into the following seven general categories based on their primary function: (1) cardiovascular health, (2) hemostasis, (3) transport proteins, (4) inflammation and immunity, (5) kidney function, (6) cellular structure, (7) and hormones and growth factors. This is the most up-to-date literature review on current prognostic markers for AAA and their functions. This review outlines the wide pathophysiological processes that are implicated in AAA disease progression.

Improvement of Theaflavins on Glucose and Lipid Metabolism in Diabetes Mellitus

In diabetes mellitus, disordered glucose and lipid metabolisms precipitate diverse complications, including nonalcoholic fatty liver disease, contributing to a rising global mortality rate. Theaflavins (TFs) can improve disorders of glycolipid metabolism in diabetic patients and reduce various types of damage, including glucotoxicity, lipotoxicity, and other associated secondary adverse effects. TFs exert effects to lower blood glucose and lipids levels, partly by regulating digestive enzyme activities, activation of OATP-MCT pathway and increasing secretion of incretins such as GIP. By the Ca2+-CaMKK ꞵ-AMPK and PI3K-AKT pathway, TFs promote glucose utilization and inhibit endogenous glucose production. Along with the regulation of energy metabolism by AMPK-SIRT1 pathway, TFs enhance fatty acids oxidation and reduce de novo lipogenesis. As such, the administration of TFs holds significant promise for both the prevention and amelioration of diabetes mellitus.

Bajitianwan formula extract ameliorates bone loss induced by iron overload via activating RAGE/PI3K/AKT pathway based on network pharmacology and transcriptomic analysis

Osteoporosis (OP) is closely related to iron overload. Bajitianwan (BJTW) is a traditional Chinese medicine formulation used for treating senile diseases such as dementia and osteoporosis. Modern pharmacological researches have found that BJTW has beneficial effect on bone loss and memory impairment in aging rats. This paper aimed to explore the role and mechanism of BJTW in ameliorating iron overload-induced bone loss. Furthermore, BJTW effectively improved the bone micro-structure of the femur in mice, and altered bone metabolism biomarkers alkaline phosphatase (ALP) and osteocalcin (OCN) in serum, as well as oxidative indexes superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) glutathione (GSH) and malondialdehyde (MDA) in liver. As for network pharmacology, 73 components collected from BJTW regulated 99 common targets merged in the BJTW and OP. The results of RNA-seq indicated that there were 418 potential targets in BJTW low dose group (BJTW-L) and 347 potential targets in BJTW high dose group (BJTW-H). Intriguingly, both PI3K-AKT signaling pathway and the AGEs-RAGE signaling pathway were contained in the KEGG pathways enrichment results of network pharmacology and transcriptomics, which were considered as the potential mechanism. Additionally, we verified that BJTW regulated the expression of related proteins in RAGE/PI3K-AKT pathways in MC3T3-E1 cells. In summary, BJTW has potent effect on protecting against iron overload-induced OP, and its mechanism may be related to the activation of the RAGE/PI3K-AKT signaling pathways.

Direct and acute effects of advanced glycation end products on proteostasis in isolated mouse skeletal muscle

Advanced glycation end products (AGEs) have been implicated in several skeletal muscle dysfunctions. However, whether the adverse effects of AGEs on skeletal muscle are because of their direct action on the skeletal muscle tissue is unclear. Therefore, this study aimed to investigate the direct and acute effects of AGEs on skeletal muscle using an isolated mouse skeletal muscle to eliminate several confounders derived from other organs. The results showed that the incubation of isolated mouse skeletal muscle with AGEs (1 mg/mL) for 2-6 h suppressed protein synthesis and the mechanistic target of rapamycin signaling pathway. Furthermore, AGEs showed potential inhibitory effects on protein degradation pathways, including autophagy and the ubiquitin-proteasome system. Additionally, AGEs stimulated endoplasmic reticulum (ER) stress by modulating the activating transcription factor 6, PKR-like ER kinase, C/EBP homologous protein, and altered inflammatory cytokine expression. AGEs also stimulated receptor for AGEs (RAGE)-associated signaling molecules, including mitogen-activated protein kinases. These findings suggest that AGEs have direct and acute effect on skeletal muscle and disturb proteostasis by modulating intracellular pathways such as RAGE signaling, protein synthesis, proteolysis, ER stress, and inflammatory cytokines.

Oxymatrine attenuates sepsis-induced inflammation and organ injury via inhibition of HMGB1/RAGE/NF-κB signaling pathway

Sepsis is a life-threatening organ dysfunction that endangers patient lives and is caused by an imbalance in the host defense against infection. Sepsis continues to be a significant cause of morbidity and mortality in critically sick patients. Oxymatrine (OMT), a quinolizidine alkaloid derived from the traditional Chinese herb Sophora flavescens Aiton, has been shown to have anti-inflammatory effects on a number of inflammatory illnesses according to research. In this study, we aimed to evaluate the therapeutic effects of OMT on sepsis and explore the underlying mechanisms. We differentiated THP-1 cells into THP-1 macrophages and studied the anti-inflammatory mechanism of OMT in a lipopolysaccharide (LPS)-induced THP-1 macrophage sepsis model. Activation of the receptor for advanced glycation end products (RAGE), as well as NF-κB, was assessed by Western blot analysis and immunofluorescence staining. ELISA was used to measure the levels of inflammatory factors. We found that OMT significantly inhibited HMGB1-mediated RAGE/NF-κB activation and downstream inflammatory cytokine production in response to LPS stimulation. Finally, an in vivo experiment was performed on septic mice to further study the effect of OMT on injured organs. The animal experiments showed that OMT significantly inhibited HMGB1-mediated RAGE/NF-κB activation, protected against the inflammatory response and organ injury induced by CLP, and prolonged the survival rate of septic mice. Herein, we provide evidence that OMT exerts a significant therapeutic effect on sepsis by inhibiting the HMGB1/RAGE/NF-κB signaling pathway.

Treatment of peritoneal fibrosis: Therapeutic prospects of bioactive Agents from Astragalus membranaceus

Peritoneal dialysis is one of the renal replacement treatments for patients with end-stage renal disease. Peritoneal dialysis-related peritoneal fibrosis is a pathological change in peritoneal tissue of peritoneal dialysis patients with progressive, non-suppurative inflammation accompanied by fibrous tissue hyperplasia, resulting in damage to the original structure and function, leading to peritoneal function failure. Currently, there is no specific drug in the clinic. Therefore, it is necessary to find a drug with good effects and few adverse reactions. Astragalus membranaceus (AMS) is the dried root of the Astragalus membranaceus (Fisch.) Bge. AMS and its active ingredients play a significant role in anti-inflammation, anti-fibrosis, regulation of immune function and regulation of blood pressure. Studies have shown that it can alleviate peritoneal fibrosis by reducing inflammatory response, inhibiting oxidative stress, degrading extracellular matrix deposition, regulating apoptosis, and regulating Transforming Growth Factor-β. The author summarized the relationship between AMS and its active ingredients by referring to relevant literature at home and abroad, in order to provide some theoretical basis for further clinical research.

Association of Glutathione Peroxidase 3 (GPx3) and miR-196a with Carbohydrate Metabolism Disorders in the Elderly

The escalating prevalence of carbohydrate metabolism disorders (CMDs) prompts the need for early diagnosis and effective markers for their prediction. Hyperglycemia, the primary indicator of CMDs including prediabetes and type 2 diabetes mellitus (T2DM), leads to overproduction of reactive oxygen species (ROS) and oxidative stress (OxS). This condition, resulting from chronic hyperglycemia and insufficient antioxidant defense, causes damage to biomolecules, triggering diabetes complications. Additionally, aging itself can serve as a source of OxS due to the weakening of antioxidant defense mechanisms. Notably, previous research indicates that miR-196a, by downregulating glutathione peroxidase 3 (GPx3), contributes to insulin resistance (IR). Additionally, a GPx3 decrease is observed in overweight/obese and insulin-resistant individuals and in the elderly population. This study investigates plasma GPx3 levels and miR-196a expression as potential CMD risk indicators. We used ELISA to measure GPx3 and qRT-PCR for miR-196a expression, supplemented by multivariate linear regression and receiver operating characteristic (ROC) analysis. Our findings included a significant GPx3 reduction in the CMD patients (n = 126), especially in the T2DM patients (n = 51), and a decreasing trend in the prediabetes group (n = 37). miR-196a expression, although higher in the CMD and T2DM groups than in the controls, was not statistically significant, potentially due to the small sample size. In the individuals with CMD, GPx3 levels exhibited a negative correlation with the mass of adipose tissue, muscle, and total body water, while miR-196a positively correlated with fat mass. In the CMD group, the analysis revealed a weak negative correlation between glucose and GPx3 levels. ROC analysis indicated a 5.2-fold increased CMD risk with GPx3 below 419.501 ng/mL. Logistic regression suggested that each 100 ng/mL GPx3 increase corresponded to a roughly 20% lower CMD risk (OR = 0.998; 95% CI: 0.996-0.999; p = 0.031). These results support the potential of GPx3 as a biomarker for CMD, particularly in T2DM, and the lack of a significant decline in GPx3 levels in prediabetic individuals suggests that it may not serve reliably as an early indicator of CMDs, warranting further large-scale validation.

Metformin attenuates lung ischemia-reperfusion injury and necroptosis through AMPK pathway in type 2 diabetic recipient rats

BACKGROUND

Diabetes mellitus (DM) can aggravate lung ischemia-reperfusion (I/R) injury and is a significant risk factor for recipient mortality after lung transplantation. Metformin protects against I/R injury in a variety of organs. However, the effect of metformin on diabetic lung I/R injury remains unclear. Therefore, this study aimed to observe the effect and mechanism of metformin on lung I/R injury following lung transplantation in type 2 diabetic rats.

METHODS

Sprague-Dawley rats were randomly divided into the following six groups: the control + sham group (CS group), the control + I/R group (CIR group), the DM + sham group (DS group), the DM + I/R group (DIR group), the DM + I/R + metformin group (DIRM group) and the DM + I/R + metformin + Compound C group (DIRMC group). Control and diabetic rats underwent the sham operation or left lung transplantation operation. Lung function, alveolar capillary permeability, inflammatory response, oxidative stress, necroptosis and the p-AMPK/AMPK ratio were determined after 24 h of reperfusion.

RESULTS

Compared with the CIR group, the DIR group exhibited decreased lung function, increased alveolar capillary permeability, inflammatory responses, oxidative stress and necroptosis, but decreased the p-AMPK/AMPK ratio. Metformin improved the function of lung grafts, decreased alveolar capillary permeability, inflammatory responses, oxidative stress and necroptosis, and increased the p-AMPK/AMPK ratio. In contrast, the protective effects of metformin were abrogated by Compound C.

CONCLUSIONS

Metformin attenuates lung I/R injury and necroptosis through AMPK pathway in type 2 diabetic lung transplant recipient rats.

Modulatory effects of rutin and vitamin A on hyperglycemia induced glycation, oxidative stress and inflammation in high-fat-fructose diet animal model

In the current study we investigated the impact of combination of rutin and vitamin A on glycated products, the glyoxalase system, oxidative markers, and inflammation in animals fed a high-fat high-fructose (HFFD) diet. Thirty rats were randomly divided into six groups (n = 5). The treatments, metformin (120 mg/kg), rutin (100 mg/kg), vitamin A (43 IU/kg), and a combination of rutin (100 mg/kg) and vitamin A (43 IU/kg) were given to relevant groups of rats along with high-fructose high-fat diet for 42 days. HbA1c, D-lactate, Glyoxylase-1, Hexokinase 2, malondialdehyde (MDA), glutathione peroxidase (GPx), catalase (CAT), nuclear transcription factor-B (NF-κB), interleukin-6 (IL-6), interleukin-8 (IL-8) and histological examinations were performed after 42 days. The docking simulations were conducted using Auto Dock package. The combined effects of rutin and vitamin A in treated rats significantly (p < 0.001) reduced HbA1c, hexokinase 2, and D-lactate levels while preventing cellular damage. The combination dramatically (p < 0.001) decreased MDA, CAT, and GPx in treated rats and decreased the expression of inflammatory cytokines such as IL-6 andIL-8, as well as the transcription factor NF-κB. The molecular docking investigations revealed that rutin had a strong affinity for several important biomolecules, including as NF-κB, Catalase, MDA, IL-6, hexokinase 2, and GPx. The results propose beneficial impact of rutin and vitamin A as a convincing treatment strategy to treat AGE-related disorders, such as diabetes, autism, alzheimer's, atherosclerosis.

Exploring the mechanism of Jinlida granules against type 2 diabetes mellitus by an integrative pharmacology strategy

Jinlida granule (JLD) is a Traditional Chinese Medicine (TCM) formula used for the treatment of type 2 diabetes mellitus (T2DM). However, the mechanism of JLD treatment for T2DM is not fully revealed. In this study, we explored the mechanism of JLD against T2DM by an integrative pharmacology strategy. Active components and corresponding targets were retrieved from Traditional Chinese Medicine System Pharmacology (TCMSP), SwissADME and Bioinformatics Analysis Tool for Molecular Mechanisms of Traditional Chinese Medicine Database (BATMAN-TCM) database. T2DM-related targets were obtained from Drugbank and Genecards databases. The protein-protein interaction (PPI) network was constructed and analyzed with STRING (Search Toll for the Retrieval of Interacting Genes/proteins) and Cytoscape to get the key targets. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) enrichment analyses were performed with the Database for Annotation, Visualization and Integrated Discovery (DAVID). Lastly, the binding capacities and reliability between potential active components and the targets were verified with molecular docking and molecular dynamics simulation. In total, 185 active components and 337 targets of JLD were obtained. 317 targets overlapped with T2DM-related targets. RAC-alpha serine/threonine-protein kinase (AKT1), tumor necrosis factor (TNF), interleukin-6 (IL-6), cellular tumor antigen p53 (TP53), prostaglandin G/H synthase 2 (PTGS2), Caspase-3 (CASP3) and signal transducer and activator of transcription 3 (STAT3) were identified as seven key targets by the topological analysis of the PPI network. GO and KEGG enrichment analyses showed that the effects were primarily associated with gene expression, signal transduction, apoptosis and inflammation. The pathways were mainly enriched in PI3K-AKT signaling pathway and AGE-RAGE signaling pathway in diabetic complications. Molecular docking and molecular dynamics simulation verified the good binding affinity between the key components and targets. The predicted results may provide a theoretical basis for drug screening of JLD and a new insight for the therapeutic effect of JLD on T2DM.

A Prospective Study on the Outcome After Mass Closure of Post-laparotomy Wound Dehiscence in a Tertiary Care Hospital, Tamil Nadu, India

Introduction The ideal abdominal wound closure provides strength and a barrier to infection. The major cause of morbidity following any laparotomy is abdominal wound dehiscence. For prompt patient recovery and outcome factors influencing wound healing following mass closure of post-laparotomy, wound dehiscence patients are evaluated in this present study. The aim of the study was to evaluate the outcome and various complications following mass closure of post-laparotomy wound dehiscence. Materials and methods A prospective study was conducted among 50 patients admitted to the Department of General Surgery, Tamil Nadu, India, with wound dehiscence following emergency and elective laparotomy surgeries managed with mass closure during the study period from 2021 to 2022. The chi-square test and Fischer's exact test were done. Results Mass closure of post-laparotomy wound dehiscence was more common among males (74%, n=37) and less common in the age group 20-30 years (12%, n=6). Prolonged bleeding time and clotting time post-surgery were associated with the type of surgery with a significant p-value of 0.007 and 0.001, respectively, by Fischer's exact test. The presence of urine albumin was also associated with the type of surgery with a significant p-value of 0.02. Surgical site infection (postoperative complication) was associated with the type of surgery and operating time with a significant p-value of 0.004 and 0.03, respectively. Conclusion Abdominal wound dehiscence is a serious and challenging postoperative complication that necessitates immediate intervention. Strict postoperative care places emphasis on reducing the risk of wound infection and other factors related to wound dehiscence.

Mechanisms of inhibition of advanced glycation end-products (AGEs) and α-glucosidase by Heliotropium bacciferum: Spectroscopic and molecular docking analysis

Diabetes mellitus is characterized by hyperglycemia that makes insulin more prone to glycation and form advanced glycation end products (AGEs). Here, we report the effect of glyoxal (GO) on the formation of AGEs using human insulin as model protein and their structural modifications. The present investigation also reports the anti-AGE potential of Heliotropium bacciferum (Leaf) extracts. The phytochemical analysis of H. bacciferum revealed that free phenolic extract contains higher amount of total phenolic (3901.58 ± 17.06 mg GAE/100 g) and total flavonoid content (30.41 ± 0.32 mg QE/100 g) when compared to bound phenolic extract. Naringin and caffeic acid were identified as the major phenolic ingredients by UPLC-PAD method. Furthermore, bound phenolics extract showed significantly higher DPPH and superoxide radicals scavenging activity (IC50 17.53 ± 0.36 μg/mL and 0.306 ± 0.038 mg/ mL, respectively) (p ≤ 0.05). Besides, the bound phenolics extract also showed significant (p ≤ 0.05) chelating power (IC50 0.063) compared to free phenolic extract. In addition, bound phenolic extract could efficiently trap GO under physiological conditions. Spectroscopic investigation of GO-modified insulin illustrated changes in the tertiary structure of insulin and formation of AGEs. On the other hand, no significant alteration in secondary structure was observed by far UV-CD measurement. Furthermore, H. bacciferum extract inhibited α-glucosidase activity and AGEs formation implicated in diabetes. Molecular docking analysis depicted that GO bind with human insulin in both chains and forms a stable complex with TYR A: 14, LEU A:13, ASN B:3, SER A:12 amino acid residues with binding energy of - 2.53 kcal/mol. However, caffeic acid binds to ASN A:18 and GLU A:17 residues of insulin with lower binding energy of -4.67 kcal/mol, suggesting its higher affinity towards human insulin compared to GO. Our finding showed promising activity of H. bacciferum against AGEs and its complications. The major phenolics like caffeic acid, naringin and their derivatives could be exploited for the drug development for management of AGEs in diabetes.

Methods to predict heart failure in diabetes patients

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is one of the leading causes of cardiovascular disease and powerful predictor for new-onset heart failure (HF).

AREAS COVERED

We focus on the relevant literature covering evidence of risk stratification based on imaging predictors and circulating biomarkers to optimize approaches to preventing HF in DM patients.

EXPERT OPINION

Multiple diagnostic algorithms based on echocardiographic parameters of cardiac remodeling including global longitudinal strain/strain rate are likely to be promising approach to justify individuals at higher risk of incident HF. Signature of cardiometabolic status may justify HF risk among T2DM individuals with low levels of natriuretic peptides, which preserve their significance in HF with clinical presentation. However, diagnostic and predictive values of conventional guideline-directed biomarker HF strategy may be non-optimal in patients with obesity and T2DM. Alternative biomarkers affecting cardiac fibrosis, inflammation, myopathy, and adipose tissue dysfunction are plausible tools for improving accuracy natriuretic peptides among T2DM patients at higher HF risk. In summary, risk identification and management of the patients with T2DM with established HF require conventional biomarkers monitoring, while the role of alternative biomarker approach among patients with multiple CV and metabolic risk factors appears to be plausible tool for improving clinical outcomes.

Ex Vivo Immune Function and Modulatory Effects of Calcitriol in Dogs with Naturally Occurring Diabetes Mellitus

Human patients with type 1 diabetes mellitus (T1DM) are susceptible to several long-term complications that are related to glycemic control and immune dysregulation. Immune function remains relatively unexplored in dogs with naturally occurring diabetes mellitus (NODM). Calcitriol improves various aspects of immune function in a variety of species, but its effect in diabetic dogs remains unexplored. Therefore, the objectives of this study were to (i) evaluate immune function in dogs with NODM and determine if differences exist based on the level of clinical control and (ii) assess the immunomodulatory effects of calcitriol. Twenty diabetic dogs (clinically controlled, n = ten, not controlled, n = ten) and 20 non-diabetic, healthy control dogs were included in this prospective, case-control study. Whole blood was incubated with calcitriol (10-7 M) or negative control, after which the samples were divided for phagocytosis and leukocyte cytokine response experiments. The phagocytosis of opsonized Escherichia coli (E. coli) was evaluated with flow cytometry. The samples for leukocyte cytokine response evaluations were stimulated with lipopolysaccharide (LPS), lipoteichoic acid (LTA), or phosphate buffer solution (PBS; negative control), and tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8, and IL-10 were measured in supernatant using a canine-specific multiplex bead-based assay. The leukocytes from diabetic dogs produced higher concentrations of IL-10 (p = 0.01), IL-6 (p < 0.0001), and IL-8 (p < 0.0001) than the control dogs while controlling for the intervention and stimulant. Calcitriol decreased the supernatant concentrations of TNF-α (p < 0.001) and IL-8 (p = 0.04) with concomitant increases in IL-6 (p = 0.005). Diabetic dogs had a lower percentage of leukocytes undergoing phagocytosis (p < 0.0001) but a higher number of bacteria phagocytized per cell (p = 0.001) when compared to the control dogs. Calcitriol had no effect on phagocytic capacity. Lastly, the status of clinical control in diabetic dogs did not yield differences in immune function. These results support that dogs with NODM exhibit immune dysregulation and warrant additional investigation.

A. officinarum Hance - P. cablin (Blanco) Benth drug pair improves oxidative stress, intracellular Ca2+ concentrations and apoptosis by inhibiting the AGE/RAGE axis to ameliorate diabetic gastroparesis: In vitro and in vivo studies

ETHNOPHARMACOLOGICAL RELEVANCE

Alpinia officinarum Hance is a perennial natural medicine herbivorous plant, has been used in the management of treat stomach pain and diabetes, it is abundantly cultivated in Qiongzhong, Baisha and other places. P. cablin (Blanco) Benth, one of the most important traditional Chinese plants, which plays functions in antioxidant and gastrointestinal regulation, has been extensively planted in Hainan, Guangdong and other regions.

AIM OF THE STUDY

In this study, we investigated the role and underlying molecular mechanism of AP on diabetic gastroparesis (DGP) in vitro and in vivo.

MATERIALS AND METHODS

In this study, using ultra-high performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS) to identify active compounds in A. officinarum Hance-P. cablin (Blanco) Benth drug pair (AP). Molecular docking were utilized to explore the potential mechanism of AP treatment of DGP. In in vitro assays, gastric smooth muscle cells (GSMCs) were treated with 35 mM glucose to promote apoptosis and construct the DGP model, which was treated with different concentrations of AP. Furthermore, transfection technology was used to overexpress RAGE in GSMCs and elucidate the underlying mechanisms of alleviation of DGP by AP.

RESULTS

Using UPLC-MS/MS analysis, nine components of AP were identified. We found that AP effectively blocked the increase in apoptosis, oxidative stress, and intracellular Ca2+ concentrations. For in vivo experiments, mice were fed with a high-fat irregular diet to construct DGP model, and AP was co-administered via oral gavage daily to prevent the development of DGP. Compared with DGP mice, AP significantly decreased fasting blood glucose levels and increased gastric emptying levels. Consistent with in vitro experiments, AP also considerably decreased the increase in oxidative stress in DGP mice. Mechanistically, AP alleviates apoptosis and DGP by decreasing oxidative stress and intracellular Ca2+ concentrations via the inhibition of the AGE/RAGE axis.

CONCLUSIONS

Collectively, this study has established that AP can improve DGP, and the mechanism may be related to the inhibition the AGE/RAGE axis to mitigate apoptosis and DGP. To summarize, this study provides a novel supplementary strategy for DGP treatment.

Revolutionizing Diabetic Foot Ulcer Care: The Senotherapeutic Approach

Diabetic foot ulcers (DFUs) are a prevalent and profoundly debilitating complication that afflicts individuals with diabetes mellitus (DM). These ulcers are associated with substantial morbidity, recurrence rates, disability, and mortality, imposing substantial economic, psychological, and medical burdens. Timely detection and intervention can mitigate the morbidity and disparities linked to DFU. Nevertheless, current therapeutic approaches for DFU continue to grapple with multifaceted limitations. A growing body of evidence emphasizes the crucial role of cellular senescence in the pathogenesis of chronic wounds. Interventions that try to delay cellular senescence, eliminate senescent cells (SnCs), or suppress the senescence-associated secretory phenotype (SASP) have shown promise for helping chronic wounds to heal. In this context, targeting cellular senescence emerges as a novel therapeutic strategy for DFU. In this comprehensive review, we look at the pathology and treatment of DFU in a systematic way. We also explain the growing importance of investigating SnCs in DFU and highlight the great potential of senotherapeutics that target SnCs in DFU treatment. The development of efficacious and safe senotherapeutics represents a pioneering therapeutic approach aimed at enhancing the quality of life for individuals affected by DFU.

Oxidative Stress: A Culprit in the Progression of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the principal culprit behind chronic kidney disease (CKD), ultimately developing end-stage renal disease (ESRD) and necessitating costly dialysis or kidney transplantation. The limited therapeutic efficiency among individuals with DKD is a result of our finite understanding of its pathogenesis. DKD is the result of complex interactions between various factors. Oxidative stress is a fundamental factor that can establish a link between hyperglycemia and the vascular complications frequently encountered in diabetes, particularly DKD. It is crucial to recognize the essential and integral role of oxidative stress in the development of diabetic vascular complications, particularly DKD. Hyperglycemia is the primary culprit that can trigger an upsurge in the production of reactive oxygen species (ROS), ultimately sparking oxidative stress. The main endogenous sources of ROS include mitochondrial ROS production, NADPH oxidases (Nox), uncoupled endothelial nitric oxide synthase (eNOS), xanthine oxidase (XO), cytochrome P450 (CYP450), and lipoxygenase. Under persistent high glucose levels, immune cells, the complement system, advanced glycation end products (AGEs), protein kinase C (PKC), polyol pathway, and the hexosamine pathway are activated. Consequently, the oxidant-antioxidant balance within the body is disrupted, which triggers a series of reactions in various downstream pathways, including phosphoinositide 3-kinase/protein kinase B (PI3K/Akt), transforming growth factor beta/p38-mitogen-activated protein kinase (TGF-β/p38-MAPK), nuclear factor kappa B (NF-κB), adenosine monophosphate-activated protein kinase (AMPK), and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling. The disease might persist even if strict glucose control is achieved, which can be attributed to epigenetic modifications. The treatment of DKD remains an unresolved issue. Therefore, reducing ROS is an intriguing therapeutic target. The clinical trials have shown that bardoxolone methyl, a nuclear factor erythroid 2-related factor 2 (Nrf2) activator, blood glucose-lowering drugs, such as sodium-glucose cotransporter 2 inhibitors, and glucagon-like peptide-1 receptor agonists can effectively slow down the progression of DKD by reducing oxidative stress. Other antioxidants, including vitamins, lipoic acid, Nox inhibitors, epigenetic regulators, and complement inhibitors, present a promising therapeutic option for the treatment of DKD. In this review, we conduct a thorough assessment of both preclinical studies and current findings from clinical studies that focus on targeted interventions aimed at manipulating these pathways. We aim to provide a comprehensive overview of the current state of research in this area and identify key areas for future exploration.

The Effect of Diabetic Retinopathy and Blood Glucose Regulation on Corneal Biomechanical Parameters

PURPOSE

The aim of this study was to evaluate the effects of different stages of diabetic retinopathy (DR) and metabolic control of blood glucose levels on corneal biomechanical parameters.

METHODS

Diabetic patients were categorized into three groups: no DR group, nonproliferative DR (NPDR) group, and proliferative DR (PDR) group. Of the 141 eyes examined, 40 belonged to the control group, 34 to no DR group, 34 to NPDR group, and 33 to PDR group. Using an Ocular Response Analyzer to measure corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated IOP (IOPcc). IOP was assessed using a Tono-Pen, while central corneal thickness (CCT) was determined using an ultrasonic pachymeter. HbA1c levels were also recorded. We conducted comparisons among these groups across biomechanical parameters and IOP (tonopen), and CCT, while also investigating the impact of HbA1c levels on these parameters.

RESULTS

Among any groups show a statistically significant difference in CCT, IOP (tonopen), CH, CRF, IOPg, and IOPcc. In diabetic patients, CRF, CTT, and IOPg values were significantly higher in those with HbA1c levels ≥ 7 mg/dl than in those with HbA1c levels < 7 mg/dl (p = 0.009, p = 0.013, p = 0.038), respectively, while there was no statistically significant difference in IOPcc, CH, and IOP (tonopen). Linear regression analysis showed that CH was positively associated with CCT (p < 0.001) and negatively associated with IOPcc (p < 0.001), while CRF was positively associated with CCT (p < 0.001), HbA1c (p < 0.05), and negatively associated with diagnosis of DR (p < 0.05).

CONCLUSION

This study underscores the influence of metabolic control, as reflected by HbA1c levels, on corneal biomechanical parameters in diabetic patients, emphasizing the importance of monitoring and managing glycemic control in this population.

Investigation of the Dysfunction Caused by High Glucose, Advanced Glycation End Products, and Interleukin-1 Beta and the Effects of Therapeutic Agents on the Microphysiological Artery Model

Diabetes mellitus (DM) has substantial global implications and contributes to vascular inflammation and the onset of atherosclerotic cardiovascular diseases. However, translating the findings from animal models to humans has inherent limitations, necessitating a novel platform. Therefore, herein, an arterial model is established using a microphysiological system. This model successfully replicates the stratified characteristics of human arteries by integrating collagen, endothelial cells (ECs), and vascular smooth muscle cells (VSMCs). Perfusion via a peristaltic pump shows dynamic characteristics distinct from those of static culture models. High glucose, advanced glycation end products (AGEs), and interleukin-1 beta are employed to stimulate diabetic conditions, resulting in notable cellular changes and different levels of cytokines and nitric oxide. Additionally, the interactions between the disease models and oxidized low-density lipoproteins (LDL) are examined. Finally, the potential therapeutic effects of metformin, atorvastatin, and diphenyleneiodonium are investigated. Metformin and diphenyleneiodonium mitigate high-glucose- and AGE-associated pathological changes, whereas atorvastatin affects only the morphology of ECs. Altogether, the arterial model represents a pivotal advancement, offering a robust and insightful platform for investigating cardiovascular diseases and their corresponding drug development.

The association between diabetes mellitus and musculoskeletal disorders: a systematic review and meta-analysis

Background

Despite the fact that DM patients are living longer, research on the prevalence of MSDs and other related illnesses is still lacking compared to that of other comorbidities. This study systematically reviewed and meta-analyzed cohort studies to determine the association between diabetes mellitus (DM) and musculoskeletal disorders (MSDs).

Methods

A comprehensive search of international databases, including Medline (PubMed), Web of Science, Scopus, and Embase, was conducted up to June 2023 to identify relevant studies investigating the association between MSDs and DM.

Results

The meta-analysis included ten cohort studies with a total of 308,445 participants. The pooled risk ratio (RR) estimate for the association between MSDs and DM was 1.03 (95% CI 1.00-1.06). Based on subgroup analysis, the association between longer duration (more than 7), European, below the age of 70, and female patients was higher than the others.

Conclusion

In conclusion, the results of this meta-analysis suggest that there may be an association between MSDs and diabetes in people with diabetes. These findings add to the existing knowledge on this topic and highlight the importance of recognition and management of MSDs in people with DM. There is a need for further research to investigate the underlying mechanisms and to develop targeted interventions for the prevention and management of MSDs in this population.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=381787, identifier CRD42022381787.

N-acetyl-L-hydroxyproline - A potent skin anti-ageing active preventing advanced glycation end-product formation in vitro and ex vivo

OBJECTIVE

Advanced glycation end-products (AGEs) represent a large group of compounds generated by a non-enzymatic reaction between reducing sugars and amino groups. The formation and accumulation of AGEs in the skin lead to protein crosslinking, dermal stiffening and yellowing, which ultimately contribute to cutaneous ageing. Amino acids have been described to exhibit anti-glycation effects. The objective of this study was to understand the inhibitory role of the amino acid derivative N-acetyl-L-hydroxyproline (NAHP) as an anti-glycation active for human skin.

METHODS

A cell-free assay investigating the inhibition of glycation of serum albumin by NAHP was used to determine the capability of NAHP to decrease AGE formation. Also, by assessing the amount of the AGE N-(carboxymethyl)lysine (CML) the anti-glycation abilities of NAHP were investigated utilizing dot blot analysis. The improvement of cell-matrix interaction by NAHP was determined in vitro using a glycated fibroblast-populated collagen lattice (FPCL) dermis model. In skin biopsies, AGE autofluorescence was determined after treatment with NAHP and/or glucose ex vivo.

RESULTS

NAHP significantly and dose-dependently inhibited levels of AGEs, which were induced by the glycation of a protein solution. This decrease could be visualized by showing that the brownish appearance as well as the AGE-specific fluorescence of glucose-treated samples were reduced after the application of increasing amounts of NAHP. Also, CML formation was dose-dependently inhibited by NAHP. In FPCLs, the contractile capacity of fibroblasts was significantly disturbed after glycation. This could be prevented by the addition of NAHP. Compared to glyoxal-treated samples, the co-application of NAHP significantly decreased the diameter as well as the weight of glycated FPCLs. Ex vivo application of glucose to skin explants showed a higher AGE fluorescence signal compared to control explants. Co-treatment with NAHP and glucose decreased the level of AGE fluorescence in comparison to glucose-treated explants.

CONCLUSION

These data provide clear evidence that under glycation stress conditions treatment with NAHP inhibited AGE formation in vitro and ex vivo and prevented the loss of cellular contractile forces in a glycated dermis model. Thus, NAHP obviously provides a beneficial treatment option to counteract AGE-related changes in human skin such as dermal stiffening and yellowish skin appearance.

Dendropanoxide Attenuates High Glucose-induced Oxidative Damage in NRK-52E Cells via AKT/mTOR Signaling Pathway

Hyperglycemia is a potent risk factor for the development and progression of diabetes-induced nephropathy. Dendropanoxide (DPx) is a natural compound isolated from Dendropanax morbifera (Araliaceae) that exerts various biological effects. However, the role of DPx in hyperglycemia-induced renal tubular cell injury remains unclear. The present study explored the protective mechanism of DPx on high glucose (HG)-induced cytotoxicity in kidney tubular epithelial NRK-52E cells. The cells were cultured with normal glucose (5.6 mM), HG (30 mM), HG + metformin (10 µM), or HG + DPx (10 µM) for 48 h, and cell cycle and apoptosis were analyzed. Malondialdehyde (MDA), advanced glycation end products (AGEs), and reactive oxygen species (ROS) were measured. Protein-based nephrotoxicity biomarkers were measured in both the culture media and cell lysates. MDA and AGEs were significantly increased in NRK-52E cells cultured with HG, and these levels were markedly reduced by pretreatment with DPx or metformin. DPx significantly reduced the levels of kidney injury molecule-1 (KIM-1), pyruvate kinase M2 (PKM2), selenium-binding protein 1 (SBP1), or neutrophil gelatinase-associated lipocalin (NGAL) in NRK-52E cells cultured under HG conditions. Furthermore, treatment with DPx significantly increased antioxidant enzyme activity. DPx protects against HG-induced renal tubular cell damage, which may be mediated by its ability to inhibit oxidative stress through the protein kinase B/mammalian target of the rapamycin (AKT/mTOR) signaling pathway. These findings suggest that DPx can be used as a new drug for the treatment of high glucose-induced diabetic nephropathy.

Regulation of the AGEs-induced inflammatory response in human periodontal ligament cells via the AMPK/NF-κB/ NLRP3 signaling pathway

The heightened prevalence and accelerated progression of periodontitis in individuals with diabetes is primarily attributed to inflammatory responses in human periodontal ligament cells (HPDLCs). This study is aimed at delineating the regulatory mechanism of nucleotide-binding oligomerization domain-like receptors (NLRs) in mediating inflammation incited by muramyl dipeptide (MDP) in HPDLCs, under the influence of advanced glycation end products (AGEs), metabolic by-products associated with diabetes. We performed RNA-seq in HPDLCs induced by AGEs treatment and delineated activation markers for the receptor of AGEs (RAGE). It showed that advanced glycation end products modulate inflammatory responses in HPDLCs by activating NLRP1 and NLRP3 inflammasomes, which are further regulated through the NF-κB signaling pathway. Furthermore, AGEs synergize with NOD2, NLRP1, and NLRP3 inflammasomes to augment MDP-induced inflammation significantly.

Behavioral and transcriptional effects of repeated electroconvulsive seizures in the neonatal MK-801-treated rat model of schizophrenia

RATIONALE

Electroconvulsive therapy (ECT) is an effective treatment modality for schizophrenia. However, its antipsychotic-like mechanism remains unclear.

OBJECTIVES

To gain insight into the antipsychotic-like actions of ECT, this study investigated how repeated treatments of electroconvulsive seizure (ECS), an animal model for ECT, affect the behavioral and transcriptomic profile of a neurodevelopmental animal model of schizophrenia.

METHODS

Two injections of MK-801 or saline were administered to rats on postnatal day 7 (PN7), and either repeated ECS treatments (E10X) or sham shock was conducted daily from PN50 to PN59. Ultimately, the rats were divided into vehicle/sham (V/S), MK-801/sham (M/S), vehicle/ECS (V/E), and MK-801/ECS (M/E) groups. On PN59, prepulse inhibition and locomotor activity were tested. Prefrontal cortex transcriptomes were analyzed with mRNA sequencing and network and pathway analyses, and quantitative real-time polymerase chain reaction (qPCR) analyses were subsequently conducted.

RESULTS

Prepulse inhibition deficit was induced by MK-801 and normalized by E10X. In M/S vs. M/E model, Egr1, Mmp9, and S100a6 were identified as center genes, and interleukin-17 (IL-17), nuclear factor kappa B (NF-κB), and tumor necrosis factor (TNF) signaling pathways were identified as the three most relevant pathways. In the V/E vs. V/S model, mitophagy, NF-κB, and receptor for advanced glycation end products (RAGE) pathways were identified. qPCR analyses demonstrated that Igfbp6, Btf3, Cox6a2, and H2az1 were downregulated in M/S and upregulated in M/E.

CONCLUSIONS

E10X reverses the behavioral changes induced by MK-801 and produces transcriptional changes in inflammatory, insulin, and mitophagy pathways, which provide mechanistic insight into the antipsychotic-like mechanism of ECT.

The analgesic effects of insulin and its disorders in streptozotocin-induced short-term diabetes

Evidence suggests that insulin resistance plays an important role in developing diabetes complications. The association between insulin resistance and pain perception is less well understood. This study aimed to investigate the effects of peripheral insulin deficiency on pain pathways in the brain. Diabetes was induced in 60 male rats with streptozotocin (STZ). Insulin was injected into the left ventricle of the brain by intracerebroventricular (ICV) injection, then pain was induced by subcutaneous injection of 2.5% formalin. Samples were collected at 4 weeks after STZ injection. Dopamine (DA), serotonin, reactive oxygen species (ROS), and mitochondrial glutathione (mGSH) were measured by ELISA, and gene factors were assessed by RT-qPCR. In diabetic rats, the levels of DA, serotonin, and mGSH decreased in the nuclei of the thalamus, raphe magnus, and periaqueductal gray, and the levels of ROS increased. In addition, the levels of expression of the neuron-specific enolase and receptor for advanced glycation end genes increased, but the expression of glial fibrillary acidic protein expression was reduced. These results support the findings that insulin has an analgesic effect in non-diabetic rats, as demonstrated by the formalin test. ICV injection of insulin reduces pain sensation, but this was not observed in diabetic rats, which may be due to cell damage ameliorated by insulin.

Research progress of the effective active ingredients of Astragalus mongholicus in the treatment of diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is one of the most prevalent consequences of diabetes, with a high incidence and disability rate. The DPN's pathogenesis is extremely complex and yet to be fully understood. Persistent high glucose metabolism, nerve growth factor deficiency, microvascular disease, oxidative stress, peripheral nerve cell apoptosis, immune factors, and other factors have been implicated in the pathogenesis of DPN. Astragalus mongholicus is a commonly used plant used to treat DPN in clinical settings. Its rich chemical components mainly include Astragalus polysaccharide, Astragalus saponins, Astragalus flavones, etc., which play a vital role in the treatment of DPN. This review aimed to summarize the pathogenesis of DPN and the studies on the mechanism of the effective components of Astragalus mongholicus in treating DPN. This is of great significance for the effective use of Chinese herbal medicine and the promotion of its status and influence on the world.

Empagliflozin ameliorates vascular calcification in diabetic mice through inhibiting Bhlhe40-dependent NLRP3 inflammasome activation

Type 2 diabetes mellitus (T2DM) patients exhibit greater susceptibility to vascular calcification (VC), which has a higher risk of death and disability. However, there is no specific drug for VC therapy. NLRP3 inflammasome activation as a hallmark event of medial calcification leads to arterial stiffness, causing vasoconstrictive dysfunction in T2DM. Empagliflozin (EMPA), a sodium-glucose co-transporter 2 inhibitor (SGLT2i), restrains hyperglycemia with definite cardiovascular benefits. Given the anti-inflammatory activity of EMPA, herein we investigated whether EMPA protected against VC in the aorta of T2DM mice by inhibiting NLRP3 inflammasome activation. Since db/db mice receiving a normal diet developed VC at the age of about 20 weeks, we administered EMPA (5, 10, 20 mg·kg-1·d-1, i.g) to 8 week-old db/db mice for 12 weeks. We showed that EMPA intervention dose-dependently ameliorated the calcium deposition, accompanied by reduced expression of RUNX2 and BMP2 proteins in the aortas. We found that EMPA (10 mg·kg-1·d-1 for 6 weeks) also protected against VC in vitamin D3-overloaded mice, suggesting the protective effects independent of metabolism. We showed that EMPA (10 mg·kg-1·d-1) inhibited the abnormal activation of NLRP3 inflammasome in aortic smooth muscle layer of db/db mice. Knockout (KO) of NLRP3 significantly alleviated VC in STZ-induced diabetic mice. The protective effects of EMPA were verified in high glucose (HG)-treated mouse aortic smooth muscle cells (MOVASs). In HG-treated NLRP3 KO MOVASs, EMPA (1 μM) did not cause further improvement. Bioinformatics and Western blot analysis revealed that EMPA significantly increased the expression levels of basic helix-loop-helix family transcription factor e40 (Bhlhe40) in HG-treated MOVASs, which served as a negative transcription factor directly binding to the promotor of Nlrp3. We conclude that EMPA ameliorates VC by inhibiting Bhlhe40-dpendent NLRP3 inflammasome activation. These results might provide potential significance for EMPA in VC therapy of T2DM patients.

Skin Autofluorescence as a Potential Adjunctive Marker for Cardiovascular Risk Assessment in Type 2 Diabetes: A Systematic Review

Diabetes mellitus (DM), due to its long-term hyperglycemia, leads to the accumulation of advanced glycation end-products (AGEs), especially in the vessel walls. Skin autofluorescence (SAF) is a non-invasive tool that measures AGEs. DM patients have a rich dietary source in AGEs, associated with high oxidative stress and long-term inflammation. AGEs represent a cardiovascular (CV) risk factor, and they are linked with CV events. Our objective was to assess whether SAF predicts future CV events (CVE) by examining its association with other CV risk factors in patients with type 2 DM (T2DM). Additionally, we assessed the strengths and limitations of SAF as a predictive tool for CVE. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology, we conducted a systematic review with CRD42024507397 protocol, focused on AGEs, T2DM, SAF, and CV risk. We identified seven studies from 2014 to 2024 that predominantly used the AGE Reader Diagnostic Optic tool. The collective number of patients involved is 8934, with an average age of 63. So, SAF is a valuable, non-invasive marker for evaluating CV risk in T2DM patients. It stands out as a CV risk factor associated independently with CVE. SAF levels are influenced by prolonged hyperglycemia, lifestyle, aging, and other chronic diseases such as depression, and it can be used as a predictive tool for CVE.

Redox Regulation of Immunometabolism in Microglia Underpinning Diabetic Retinopathy

Diabetic retinopathy (DR) is the leading cause of visual impairment and blindness among the working-age population. Microglia, resident immune cells in the retina, are recognized as crucial drivers in the DR process. Microglia activation is a tightly regulated immunometabolic process. In the early stages of DR, the M1 phenotype commonly shifts from oxidative phosphorylation to aerobic glycolysis for energy production. Emerging evidence suggests that microglia in DR not only engage specific metabolic pathways but also rearrange their oxidation-reduction (redox) system. This redox adaptation supports metabolic reprogramming and offers potential therapeutic strategies using antioxidants. Here, we provide an overview of recent insights into the involvement of reactive oxygen species and the distinct roles played by key cellular antioxidant pathways, including the NADPH oxidase 2 system, which promotes glycolysis via enhanced glucose transporter 4 translocation to the cell membrane through the AKT/mTOR pathway, as well as the involvement of the thioredoxin and nuclear factor E2-related factor 2 antioxidant systems, which maintain microglia in an anti-inflammatory state. Therefore, we highlight the potential for targeting the modulation of microglial redox metabolism to offer new concepts for DR treatment.

The RAGE Axis: A Relevant Inflammatory Hub in Human Diseases

In 1992, a transcendental report suggested that the receptor of advanced glycation end-products (RAGE) functions as a cell surface receptor for a wide and diverse group of compounds, commonly referred to as advanced glycation end-products (AGEs), resulting from the non-enzymatic glycation of lipids and proteins in response to hyperglycemia. The interaction of these compounds with RAGE represents an essential element in triggering the cellular response to proteins or lipids that become glycated. Although initially demonstrated for diabetes complications, a growing body of evidence clearly supports RAGE's role in human diseases. Moreover, the recognizing capacities of this receptor have been extended to a plethora of structurally diverse ligands. As a result, it has been acknowledged as a pattern recognition receptor (PRR) and functionally categorized as the RAGE axis. The ligation to RAGE leads the initiation of a complex signaling cascade and thus triggering crucial cellular events in the pathophysiology of many human diseases. In the present review, we intend to summarize basic features of the RAGE axis biology as well as its contribution to some relevant human diseases such as metabolic diseases, neurodegenerative, cardiovascular, autoimmune, and chronic airways diseases, and cancer as a result of exposure to AGEs, as well as many other ligands.

Molecular mechanisms of metabolic dysregulation in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM), one of the most serious complications of diabetes mellitus, has become recognized as a cardiometabolic disease. In normoxic conditions, the majority of the ATP production (>95%) required for heart beating comes from mitochondrial oxidative phosphorylation of fatty acids (FAs) and glucose, with the remaining portion coming from a variety of sources, including fructose, lactate, ketone bodies (KB) and branched chain amino acids (BCAA). Increased FA intake and decreased utilization of glucose and lactic acid were observed in the diabetic hearts of animal models and diabetic patients. Moreover, the polyol pathway is activated, and fructose metabolism is enhanced. The use of ketones as energy sources in human diabetic hearts also increases significantly. Furthermore, elevated BCAA levels and impaired BCAA metabolism were observed in the hearts of diabetic mice and patients. The shift in energy substrate preference in diabetic hearts results in increased oxygen consumption and impaired oxidative phosphorylation, leading to diabetic cardiomyopathy. However, the precise mechanisms by which impaired myocardial metabolic alterations result in diabetes mellitus cardiac disease are not fully understood. Therefore, this review focuses on the molecular mechanisms involved in alterations of myocardial energy metabolism. It not only adds more molecular targets for the diagnosis and treatment, but also provides an experimental foundation for screening novel therapeutic agents for diabetic cardiomyopathy.

(+)-Catechin mitigates impairment in insulin secretion and beta cell damage in methylglyoxal-induced pancreatic beta cells

BACKGROUND

The formation of advanced glycation end products (AGEs) is the central process contributing to diabetic complications in diabetic individuals with sustained and inconsistent hyperglycemia. Methylglyoxal, a reactive carbonyl species, is found to be a major precursor of AGEs, and its levels are elevated in diabetic conditions. Dysfunction of pancreatic beta cells and impairment in insulin secretion are the hallmarks of diabetic progression. Exposure to methylglyoxal-induced AGEs alters the function and maintenance of pancreatic beta cells. Hence, trapping methylglyoxal could be an ideal approach to alleviate AGE formation and its influence on beta cell proliferation and insulin secretion, thereby curbing the progression of diabetes to its complications.

METHODS AND RESULTS

In the present study, we have explored the mechanism of action of (+)-Catechin against methylglyoxal-induced disruption in pancreatic beta cells via molecular biology techniques, mainly western blot. Methylglyoxal treatment decreased insulin synthesis (41.5%) via downregulating the glucose-stimulated insulin secretion pathway (GSIS). This was restored upon co-treatment with (+)-Catechin (29.9%) in methylglyoxal-induced Beta-TC-6 cells. Also, methylglyoxal treatment affected the autocrine function of insulin by disrupting the IRS1/PI3k/Akt pathway. Methylglyoxal treatment suppresses Pdx-1 and Maf A levels, which are responsible for beta cell maintenance and cell proliferation. (+)-Catechin could significantly augment the levels of these transcription factors.

CONCLUSION

This is the first study to examine the impact of a natural compound on methylglyoxal with the insulin-mediated autocrine and paracrine activities of pancreatic beta cells. The results indicate that (+)-Catechin exerts a protective effect against methylglyoxal exposure in pancreatic beta cells and can be considered a potential anti-glycation agent in further investigations on ameliorating diabetic complications.

A systematic review of astragaloside IV effects on animal models of diabetes mellitus and its complications

Context

Diabetes mellitus (DM) is one of the fastest-growing diseases worldwide; however, its pathogenesis remains unclear. Complications seriously affect the quality of life of patients in the later stages of diabetes, ultimately leading to suffering. Natural small molecules are an important source of antidiabetic agents.

Objective

Astragaloside IV (AS-IV) is an active ingredient of Astragalus mongholicus (Fisch.) Bunge. We reviewed the efficacy and mechanism of action of AS-IV in animal and cellular models of diabetes and the mechanism of action of AS-IV on diabetic complications in animal and cellular models. We also summarized the safety of AS-IV and provided ideas and rationales for its future clinical application.

Methods

Articles on the intervention in DM and its complications using AS-IV, such as those published in SCIENCE, PubMed, Springer, ACS, SCOPUS, and CNKI from the establishment of the database to February 2022, were reviewed. The following points were systematically summarized: dose/concentration, route of administration, potential mechanisms, and efficacy of AS-IV in animal models of DM and its complications.

Results

AS-IV has shown therapeutic effects in animal models of DM, such as alleviating gestational diabetes, delaying diabetic nephropathy, preventing myocardial cell apoptosis, and inhibiting vascular endothelial dysfunction; however, the potential effects of AS-IV on DM should be investigated.

Conclusion

AS-IV is a potential drug for the treatment of diabetes and its complications, including diabetic vascular disease, cardiomyopathy, retinopathy, peripheral neuropathy, and nephropathy. In addition, preclinical toxicity studies indicate that it appears to be safe, but the safe human dose limit is yet to be determined, and formal assessments of adverse drug reactions among humans need to be further investigated. However, additional formulations or structural modifications are required to improve the pharmacokinetic parameters and facilitate the clinical use of AS-IV.

Potential application of Nardostachyos Radix et Rhizoma-Rhubarb for the treatment of diabetic kidney disease based on network pharmacology and cell culture experimental verification

BACKGROUND

Diabetic kidney disease (DKD) is one of the serious complications of diabetes mellitus, and the existing treatments cannot meet the needs of today's patients. Traditional Chinese medicine has been validated for its efficacy in DKD after many years of clinical application. However, the specific mechanism by which it works is still unclear. Elucidating the molecular mechanism of the Nardostachyos Radix et Rhizoma-rhubarb drug pair (NRDP) for the treatment of DKD will provide a new way of thinking for the research and development of new drugs.

AIM

To investigate the mechanism of the NRDP in DKD by network pharmacology combined with molecular docking, and then verify the initial findings by in vitro experiments.

METHODS

The Traditional Chinese Medicine Systems Pharmacology (TCMSP) database was used to screen active ingredient targets of NRDP. Targets for DKD were obtained based on the Genecards, OMIM, and TTD databases. The VENNY 2.1 database was used to obtain DKD and NRDP intersection targets and their Venn diagram, and Cytoscape 3.9.0 was used to build a "drug-component-target-disease" network. The String database was used to construct protein interaction networks. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and Gene Ontology analysis were performed based on the DAVID database. After selecting the targets and the active ingredients, Autodock software was used to perform molecular docking. In experimental validation using renal tubular epithelial cells (TCMK-1), we used the Cell Counting Kit-8 assay to detect the effect of NRDP on cell viability, with glucose solution used to mimic a hyperglycemic environment. Flow cytometry was used to detect the cell cycle progression and apoptosis. Western blot was used to detect the protein expression of STAT3, p-STAT3, BAX, BCL-2, Caspase9, and Caspase3.

RESULTS

A total of 10 active ingredients and 85 targets with 111 disease-related signaling pathways were obtained for NRDP. Enrichment analysis of KEGG pathways was performed to determine advanced glycation end products (AGEs)-receptor for AGEs (RAGE) signaling as the core pathway. Molecular docking showed good binding between each active ingredient and its core targets. In vitro experiments showed that NRDP inhibited the viability of TCMK-1 cells, blocked cell cycle progression in the G0/G1 phase, and reduced apoptosis in a concentration-dependent manner. Based on the results of Western blot analysis, NRDP differentially downregulated p-STAT3, BAX, Caspase3, and Caspase9 protein levels (P < 0.01 or P < 0.05). In addition, BAX/BCL-2 and p-STAT3/STAT3 ratios were reduced, while BCL-2 and STAT3 protein expression was upregulated (P < 0.01).

CONCLUSION

NRDP may upregulate BCL-2 and STAT3 protein expression, and downregulate BAX, Caspase3, and Caspase9 protein expression, thus activating the AGE-RAGE signaling pathway, inhibiting the vitality of TCMK-1 cells, reducing their apoptosis. and arresting them in the G0/G1 phase to protect them from damage by high glucose.

TGF-β Signaling Pathways in the Development of Diabetic Retinopathy

Diabetic retinopathy (DR), a prevalent complication of diabetes mellitus affecting a significant portion of the global population, has long been viewed primarily as a microvascular disorder. However, emerging evidence suggests that it should be redefined as a neurovascular disease with multifaceted pathogenesis rooted in oxidative stress and advanced glycation end products. The transforming growth factor-β (TGF-β) signaling family has emerged as a major contributor to DR pathogenesis due to its pivotal role in retinal vascular homeostasis, endothelial cell barrier function, and pericyte differentiation. However, the precise roles of TGF-β signaling in DR remain incompletely understood, with conflicting reports on its impact in different stages of the disease. Additionally, the BMP subfamily within the TGF-β superfamily introduces further complexity, with BMPs exhibiting both pro- and anti-angiogenic properties. Furthermore, TGF-β signaling extends beyond the vascular realm, encompassing immune regulation, neuronal survival, and maintenance. The intricate interactions between TGF-β and reactive oxygen species (ROS), non-coding RNAs, and inflammatory mediators have been implicated in the pathogenesis of DR. This review delves into the complex web of signaling pathways orchestrated by the TGF-β superfamily and their involvement in DR. A comprehensive understanding of these pathways may hold the key to developing targeted therapies to halt or mitigate the progression of DR and its devastating consequences.

A Narrative Review of Diabetic Macroangiopathy: From Molecular Mechanism to Therapeutic Approaches

Diabetic macroangiopathy, a prevalent and severe complication of diabetes mellitus, significantly contributes to the increased morbidity and mortality rates among affected individuals. This complex disorder involves multifaceted molecular mechanisms that lead to the dysfunction and damage of large blood vessels, including atherosclerosis (AS) and peripheral arterial disease. Understanding the intricate pathways underlying the development and progression of diabetic macroangiopathy is crucial for the development of effective therapeutic interventions. This review aims to shed light on the molecular mechanism implicated in the pathogenesis of diabetic macroangiopathy. We delve into the intricate interplay of chronic inflammation, oxidative stress, endothelial dysfunction, and dysregulated angiogenesis, all of which contribute to the vascular complications observed in this disorder. By exploring the molecular mechanism involved in the disease we provide insight into potential therapeutic targets and strategies. Moreover, we discuss the current therapeutic approaches used for treating diabetic macroangiopathy, including glycemic control, lipid-lowering agents, and vascular interventions.

Salivary and crevicular fluid proinflammatory cytokines and advanced glycation end products in patients with different glycemic levels undergoing fixed orthodontic treatment

OBJECTIVE

To examine whether patients with different blood glycemic levels undergoing fixed orthodontic therapy demonstrate changes in the biochemical profiles of crevicular fluid and salivary advanced glycation end products (AGEs) and proinflammatory cytokine levels in comparison with nondiabetic healthy subjects.

MATERIALS AND METHODS

Prediabetic subjects, subjects with type 2 diabetes mellitus (T2DM), and subjects without a diabetes mellitus diagnosis undergoing fixed orthodontic therapy with MBT prescription brackets (0.022-inch brackets and 0.019 × 0.025-inch stainless steel archwires) were included in the study. The following clinical periodontal parameters were evaluated: (1) plaque score (PS), (2) probing depth (PD), (3) bleeding on probing (BOP), and (4) clinical attachment loss. Crevicular fluid and saliva specimens were collected during regular orthodontic visits. Salivary and crevicular fluid tumor necrosis factor alpha, interleukin-6, ghrelin, resistin, AGEs, and receptor activator of nuclear factor κΒ ligand were evaluated using a human magnetic Luminex multiplex assay.

RESULTS

BOP scores were significantly higher among T2DM subjects (19.2%) than among nondiabetic subjects (11.2%) and prediabetic subjects (15.9%). Comparable values were demonstrated by all three study groups regarding PD scores and PSs. T2DM subjects demonstrated higher scores for gingival crevicular fluid (GCF) chemokines than nondiabetic and prediabetic subjects. A statistically significant difference was found in the levels of AGEs and resistin among the three study groups. The scores revealed for the levels of GCF resistin and AGEs versus periodontal BOP demonstrated a significant positive association by the Pearson correlation test.

CONCLUSIONS

T2DM patients demonstrated significantly higher levels of GCF resistin and AGEs during fixed orthodontic therapy. Chronic hyperglycemic patients undergoing orthodontic therapy demonstrated a proinflammatory response.

P75NTR regulates autophagy through the YAP-mTOR pathway to increase the proliferation of interfollicular epidermal cells and promote wound healing in diabetic mice

Wound healing is delayed in diabetic patients. Increased autophagy and dysfunction of interfollicular epidermal (IFE) cells are closely associated with delayed healing of diabetic wounds. Autophagy plays an important role in all stages of wound healing, but its role in diabetic wound healing and the underlying molecular mechanisms are not clear. Here, we found that diabetic mice had delayed wound healing and increased autophagy in wounds compared with normal mice and that chloroquine, an inhibitor of autophagy, decreased the level of autophagy, improved the function of IFE cells, and accelerated wound healing in diabetic mice. Treatment of IFE cells with advanced glycosylation end products (AGEs) resulted in increased microtubule-associated protein chain (LC3) expression and decreased prostacyclin-62 (P62) expression, indicating increased autophagy in AGE-treated IFE cells. Moreover, P75NTR reduced autophagy in IFE cells in the presence of AGEs and significantly increased the proliferation of IFE cells. In addition, P75NTR participated in regulating autophagy in IFE cells and in wounds in diabetic mice through the YAP-mTOR signalling pathway, which increased the functional activity of the cells and the healing rate of wounds in diabetic mice. Thus, our study suggests that P75NTR protects IFE cells against AGEs by affecting autophagy and accelerating wound healing in diabetic mice, providing a basis for understanding the role of autophagy in diabetic wound healing.

Potential inhibitory effect of Auricularia auricula polysaccharide on advanced glycation end-products (AGEs)

In this study, a novel polysaccharide, AAP-2S, was extracted from Auricularia auricula, and the anti-glycosylation effect of AAP-2S and its underlying mechanisms were investigated using an in vitro BSA-fructose model and a cellular model. The results demonstrated the inhibiting formation of advanced glycation end products (AGEs) in vitro by AAP-2S. Concurrently, it attenuated oxidative damage to proteins in the model, preserved protein sulfhydryl groups from oxidation, reduced protein carbonylation, prevented structural alterations in proteins, and decreased the formation of β-crosslinked structures. Furthermore, AAP-2S demonstrated metal-chelating capabilities. GC-MS/MS-based metabolomics were employed to analyze changes in metabolic profiles induced by AAP-2S in a CML-induced HK-2 cell model. Mechanistic investigations revealed that AAP-2S could mitigate glycosylation and ameliorate cell fibrosis by modulating the RAGE/TGF-β/NOX4 pathway. This study provides a foundational framework for further exploration of Auricularia auricular polysaccharide as a natural anti-AGEs agent, paving the way for its potential development and application as a food additive.