Diabetic Vascular Disease Research Articles

Cerebral Embolic Protection by Geographic Region

Transcatheter aortic valve replacement (TAVR) is an established treatment option for many patients with severe symptomatic aortic stenosis; however, debris dislodged during the procedure can cause embolic stroke. The Sentinel cerebral embolic protection (CEP) device is approved for capture and removal of embolic material during TAVR but its efficacy has been debated. To explore regional differences in the association of CEP utilization with stroke outcomes in patients undergoing TAVR. This post hoc analysis of a prospective, postmarket, randomized clinical trial evaluating TAVR performed with or without the CEP took place at 51 hospitals in the US, Europe, and Australia from February 2020 to January 2022. Patients with symptomatic aortic stenosis treated with transfemoral TAVR were included. Randomization was stratified according to center, operative risk, and intended TAVR valve type. Patients were excluded if the left common carotid or brachiocephalic artery had greater than 70% stenosis or if the anatomy precluded placement of the CEP device. Data for this post hoc study were analyzed from August to October 2024. TAVR with or without CEP. The primary end point was the rate of all stroke events at hospital discharge or 72 hours post-TAVR, whichever came first. Neurological examinations were performed at baseline and postprocedure to identify stroke, disabling stroke, and other neurological outcomes. The Stroke Protection With Sentinel During Transcatheter Aortic Valve Replacement (PROTECTED TAVR) trial enrolled and randomized 3000 patients (1803 [60.1%] male; mean [SD] age, 78.9 [7.8] years): 1833 in the US cohort (TAVR alone: 919, TAVR with CEP: 914) and 1167 patients in the outside the US (OUS) cohort (TAVR alone: 580, TAVR with CEP: 587). Patients in the US cohort were younger, more predominantly male, had a lower prevalence of atrial fibrillation, and had a higher prevalence of bicuspid aortic valve, diabetes, and peripheral vascular disease compared with the OUS cohort. In the main trial, the incidence of stroke within 72 hours after TAVR or before discharge did not differ significantly between the CEP group and the control group, and there was no interaction by geographic region. In this post hoc analysis, patients treated with CEP in the US cohort exhibited a 50% relative risk reduction for overall stroke and a 73% relative risk reduction for disabling stroke compared to TAVR alone; a treatment effect on stroke risk reduction was not observed in the OUS cohort. The PROTECTED TAVR trial could not show that the use of CEP had a significant effect on the incidence of periprocedural stroke during TAVR. Although there was no significant interaction by geographic region, this exploratory post hoc analysis suggests a trend toward greater stroke reduction in the US cohort but not in the OUS cohort. These findings are hypothesis generating, and further research is needed to determine if regional differences in patient characteristics or procedural practices affect CEP efficacy. ClinicalTrials.gov Identifier: NCT04149535.

Molecular Mechanisms of Methylglyoxal in Diabetes-related Macrovascular Complications

Diabetes mellitus (DM) is a chronic endocrine and metabolic disease indicated by the presence of hyperglycemia. It has been known that hyperglycemia and oxidative stress are the main culprit of all DM complications, including macrovascular complications. As a byproduct of lipid, protein, and carbohydrate metabolism, methylglyoxal (MGO) is a highly reactive substance which plays a positive signaling role in helping cells regain redox balance under oxidative stress circumstances. DM-related problems lead to an excess of mitochondrial superoxide in the heart and big and small vascular endothelial cells. Elevated intracellular reactive oxygen species induce impaired angiogenesis in reaction to ischemia, trigger several proinflammatory pathways, and result in enduring epigenetic modifications that propel the continuous expression of proinflammatory genes even after glucose levels return to normal. Over time, the significance of the extremely quick advanced glycation end-products (AGE) production caused by the extremely reactive MGO has been clarified. It is now evident that MGO causes vascular tissue to react maladaptively. Glyoxalase 1 (GLO1) is the primary enzyme in an organism's enzymatic glyoxalase defense mechanism, which converts MGO to D-lactate in order to counteract the harmful effects of MGO. Understanding the role of the MGO–GLO1 pathway in the etiology of vascular disease in diabetes has advanced significantly. Therefore, it can be summarized that vascular damage are linked to diabetes. The AGE precursor MGO are important in determining the connection between diabetes and vascular damage. MGO and AGEs play a role in several phases of the development of diabetes complications. MGO and AGEs may be useful therapeutic targets for diabetes's macrovascular problems.KEYWORDS: hyperglycemia, AGE, methylglyoxal, glyoxalase, D-lactate, gluthatione, oxidative stress.

Long non-coding RNA PANDA promotes endothelial senescence and oxidative damage through the interaction with NRF2

Abstract Background Accumulation of reactive oxygen species and inflammation are major features of diabetic vasculopathy, yet the underlying mechanisms remain elusive. LncRNAs are emerging as important players in the pathogenesis of cardiovascular disease. PANDA, a newly identified lncRNA, is a key regulator of cellular senescence, apoptosis and oxidative stress. Purpose To investigate the role and molecular mechanism of PANDA in diabetic vascular disease. Methods RNAseq was performed to aorta specimen from diabetic and no diabetic patients as well to HAECs exposed to 5 mM and 25 mM concentrations (Normal -NG- and High -HG-, respectively). PANDA depletion in HG-treated HAECs was obtained by siRNA transfection while a scrambled siRNA wass used as a negative control. RNAseq and network perturbation analysis (NPA) of treated HAECs unveiled transcriptional changes upon PANDA depletion. Expression of PANDA was assessed by real time PCR. PANDA RNA-IP was performed to check its binding to relevant transcriptional factor (such as NRF2) as well Ch-IP was performed to check the NRF2 binding on oxidative gene promoters. Cellular localization of NRF2 was investigated by Immunofluorescence. Beta-galactosidase and superoxide staining was used to detect endothelial senescence and ROS formation; while, migration and tube formation were employed to evaluate angiogenic properties of HAECs. Results PANDA expression was significantly increased in diabetic human aorta as well in HG-treated HAECs (Figure1 A-B). Transcriptomic analysis revealed dysregulation of several genes upon PANDA silencing with the antioxidant gene heme oxygenase-1 (HMOX1) as the top-ranking transcript in HG cells (Figure1 C-D). Western blot analysis reveals the restored level of HMOX1 and TFRC1 upon PANDA depletion (Figure1 E-G). NPA analysis showed a strong involvement of PANDA in senescence, DNA damage, NRF2 signaling, hypoxic stress response and proliferation. In HG, NFR2 is downregulated while PANDA silencing restores its level (Figure1 I-J). We found that in HG condition PANDA binds the transcription factor NRF2 and blocks its nuclear translocation thus impeding its binding on HMOX1 and TFRC promoters (Figure1 K-M). Silencing of PANDA in HG-treated HAECs reduced genes and cellular features of senescence (Figure2 A-B), restored the expression of anti-apoptotic genes and decreases caspase 3 activity (Figure2 C-D), improved endothelial migration and tube formation (Figure2 E and G), and reduced ROS formation (Figure2 F). Conclusions In hyperglycemia PANDA upregulation drives endothelial senescence while impairing angiogenic properties. On the other hand, PANDA depletion in HG-treated HAECs rescues maladaptive transcriptional changes through the release of NRF2 that in turn translocate into the nucleus enhancing the expression of the antioxidant gene HMOX1. The results indicate PANDA as a putative novel molecular target in the setting of diabetic vascular disease (Figure2 H).

Redefining the role of autophagy in diabetic vascular diseases

Redefining the role of autophagy in diabetic vascular diseases

Luteolin Protects against Vascular Calcification by Modulating SIRT1/CXCR4 Signaling Pathway and Promoting Autophagy.

Vascular calcification (VC) is a common pathological manifestation of atherosclerosis, hypertension, diabetes vascular disease, vascular injury, chronic kidney disease and aging, which is mainly manifested as increased stiffness of the vascular wall. Oxidative stress and autophagy dysfunction are key factors in the pathogenesis of vascular calcification, but the specific mechanisms and the therapeutic strategy of vascular calcification have not been clarified. In the present study, Sirtuin 1 (SIRT1) was screened as the therapeutic targets for vascular calcification by the bioinformatics. SIRT1 is a nicotinamide adenine dinucleotide, which plays an important role in inhibiting oxidative stress and promoting autophagy. Luteolin(LUT), a kind of natural tetrahydroxyl flavonoid, exists in many plants and has many pharmacological effects such as anti-oxidation and anti-apoptosis. We have reported that luteolin has certain anti-osteoporosis effects in the previous study, and it is accepted that the development of vascular calcification is similar to bone formation, indicating that luteolin may also resist vascular calcification. And luteolin is known to activate SIRT1 to some extent. Moreover, the molecular docking analysis predicted that SIRT1 could bind directly to luteolin. Therefore, the purpose of this study was to investigate the potential role of luteolin in inhibiting oxidative stress and promoting autophagy during vascular calcification via modulating SIRT1 expression. The results showed that luteolin significantly improved vascular calcification induced by a high-fat diet (HFD) and vitamin D3 in rats in vivo. In addition, luteolin significantly repressed the formation of mineralized nodules and ALP activity in H2O2-treated A7r5 cells. Luteolin reduced the level of MDA, LDH and ROS generation, inhibited the protein expression of cleaved caspase-3, cleaved caspase-9, β-catenin and BMP-2 in the aortic tissue of the rat and rat smooth muscle cells (A7r5) treated with hydrogen peroxide. At the same time, luteolin could promote the expression of autophagy related proteins. Moreover, luteolin also produced effects to increase the protein expression levels of SIRT1 more than 2 times both in vivo and in vitro. In terms of mechanism, luteolin attenuated vascular calcification by inhibiting oxidative stress and improving autophagy level, via modulating SIRT1 / CXCR4 signaling pathway. In conclusion, this experiment for the first time revealed that LUT protected against VC via modulating SIRT1 / CXCR4 signaling pathway to promote autophagy and inhibit vascular calcification and may be developed as a new therapeutic agent for vascular calcification and atherosclerosis.

Altered RBC deformability in diabetes: clinical characteristics and RBC pathophysiology

BackgroundReduced red blood cell deformability (RBCD) is associated with diabetic vascular complications, but early pathophysiological RBC changes and predictive demographic and clinical factors in populations with diabetes are unclear. An understanding of early diabetes-specific RBC changes associated with impaired RBCD is essential in investigating mechanisms that predispose to diabetic vascular complications.MethodsWe conducted an outpatient cross-sectional study of participants in a well-controlled diabetes cohort (N81) and nondiabetic controls (N78) at the National Institutes of Health. First, between-group differences in RBCD measures were assessed with shear stress-gradient ektacytometry. Differences in structural RBC parameters were assessed using osmotic gradient ektacytometry and NaCl osmotic fragility. Functional RBC changes were assessed using hemoglobin-oxygen dissociation: p50.ResultsAll shear-stress gradient RBCD measures were significantly altered in the diabetes cohort vs. nondiabetic controls, even after adjustment for confounding covariates (p < 0.001). Adjusted for diabetes-status and demographic factors, significant predictors of reduced RBCD included older age, Black race, male gender, hyperglycemia, and vascular complications (all p < 0.05). Reduced RBCD was also associated with aberrant osmotic-gradient parameters, with a left-shift on osmotic gradient profile indicative of dehydrated RBCs in diabetes. A structure-function relationship was observed with reduced RBCD associated with reduced osmotic fragility (P < 0.001) and increased hemoglobin-oxygen dissociation (P < 0.01).ConclusionsFindings suggest impaired RBCD incurs similar demographic and clinical risk factors as diabetic vascular disease, with early pathophysiological RBC changes indicative of disordered RBC hydration in diabetes. Findings provide strong evidence for disordered oxygen release as a functional consequence of reduced RBCD.Clinical trial number: NCT00071526.

Effect of MSC-derived EVs induced by AGEs on energy metabolism in vascular endothelial cells

IntroductionAdvanced glycation end products (AGEs) play a critical role in the development of vascular diseases in diabetes. While stem cell therapies often involve exposure to AGEs, the impact of this environment on extracellular vesicles (EVs) and endothelial cell metabolism remains unclear. MethodsHuman umbilical cord mesenchymal stem cells (MSC) were treated with either 0 ng/mL or 100 ng/mL AGEs in a serum-free medium for 48 hours, after which MSC-EVs were isolated. The EVs were characterized for morphology, particle size, and protein markers of MSC-EVs, and performed miRNA sequencing to identify differentially expressed miRNAs. MSC-EVs were co-cultured with HUVEC cells to assess effects on cell viability, metabolic activity, oxidative stress, and antioxidant capacity. Tube formation and glucose transporter protein analyses were conducted to evaluate the angiogenic ability and glucose metabolism capacity. ResultsMSC-EVs ranged from 30 to 150 nm, consistenting with exosomal properties. AGEs treatment reduced MSC viability but had minimal effect on EV morphology and protein markers. miRNAs sequencing showed downregulation of hsa-miR-223-3p, hsa-miR-126-3p_R-1, with upregulation of hsa-miR-574-5p, implicating changes in glycolytic and oxidative phosphorylation pathways. MSC-EVs treated with AGEs decreased HUVEC viability (P<0.05), pH (P<0.05), ATP metabolism (P<0.05), glucose metabolism (P<0.05), while enhancing glycolysis processes, including glycolytic activity, capacity, and reserve (P<0.05). This likely resulted from impaired mitochondrial function, including reduced ATP production, maximal respiration, basal respiration, and spare respiratory capacity (P<0.05), or increased ROS (P<0.05) and G6PD activity (P<0.05). Additionally, AGEs reduced GLUT1, GLUT3, GLUT4, and SCO2 expression (P<0.05), along with angiogenic capacity (P<0.05) in HUVEC cells. ConclusionExposure to AGEs diminishes the therapeutic potential of MSC-derived EVs by disrupting energy metabolism and promoting metabolic reprogramming in endothelial cells. These findings suggest that adjusting the dosage or frequency of MSC-EVs may enhance their efficacy for treating diabetes-related vascular conditions. Further research is warranted to evaluate AGEs' broader impact on various cell types and metabolic pathways for improved exosome-based therapies.

Neuroma morphology: A macroscopic classification system.

Neuromas come in different shapes and sizes; yet the correlation between neuroma morphology and symptomatology is unknown. Therefore, we aim to investigate macroscopic traits of excised human neuromas and assess the validity of a morphological classification system and its potential clinical implications. End-neuroma specimens were collected from prospectively enrolled patients undergoing symptomatic neuroma surgery. Protocolized images of the specimens were obtained intraoperatively. Pain data (Numeric rating scale, 0-10) were prospectively collected during preoperative interview, patient demographic and comorbidity factors were collected from chart review. A morphological classification is proposed, and the inter-rater reliability (IRR) was assessed. Distribution of neuroma morphology with patient factors, was described. Forty-five terminal neuroma specimens from 27 patients were included. Residual limb patients comprised 93% of the population, of which 2 were upper (8.0%) and 23 (92.0%) were lower extremity residual limb patients. The proposed morphological classification, consisting of three groups (bulbous, fusiform, atypical), demonstrated a strong IRR (Cohen's kappa = 0.8). Atypical neuromas demonstrated higher preoperative pain, compared with bulbous and fusiform. Atypical morphology was more prevalent in patients with diabetes and peripheral vascular disease. A validated morphological classification of neuroma is introduced. These findings may assist surgeons and researchers with better understanding of symptomatic neuroma development and their clinical implications. The potential relationship of neuroma morphology with the vascular and metabolic microenvironment requires further investigation.

Automated Analysis Of Diabetic Vasculopathy Using Semantic Segmentation Of Thermal Images Of Peroneal Vessel

Introduction: Diabetic vascular disease is one of most serious health problems in diabetic patients, it causes the development of severe complications including delayed wound healing and increased susceptibility to infections. Methods: To provide accurate and are non-invasive diagnosis, current work emphasizes on Diabetic Vasculopathy (DV) that is analysed with thermoregulation images through Semantic Segmentation (SS). A novel methodology was adapted, combining thermoregulation imaging with SS using the U-Net++ model to investigate temperature distributions at the skin level. This work introduces a novel method that utilizes MobileNetV2 as the encoder for fast Feature Extraction (FE). Results: The results from the suggested model, achieves a segmentation accuracy of 95%, which is significantly more compared to that of DeepLabV3+ and PSPNet models. A mean and Intersection over Union (IoU) of 85% and 87% was reported by the suggested frameworks throughout the training and validation phases. Conclusion: Classifying normal and abnormal regions can be done via the outcomes, as it offers the great visibility in the thermal image for clinicians by detecting the non-thermal regions

A Knitted and MXenzyme-Integrated Dressing for Geriatrics Diagnosis and Ulcer Healing.

Integrated diagnostic and therapeutic dressings are desirable to relieve diabetic patients who often suffer from diabetic foot ulcers (DFUs) and peripheral vascular diseases (PVDs). However, it is highly difficult to monitor the pulse waves with fidelity under wet environments and connect the waveforms to diseases through a small strain sensor. Additionally, immobilizing MXenzyme to regulate spatially heterogeneous levels of reactive oxygen species (ROS) and applying active intervention to enhance ulcer healing on a single structure remain a complex task. To address these issues, we designed a multiscale wearable dressing comprising a knitted all-textile sensing array for quantitatively investigating the pulse wave toward PVD diagnosis. MXenzyme was loaded onto the dressing to provide multiple enzyme mimics for anti-inflammatory activities and deliver electrical stimulation to promote wound growth. In mice, we demonstrate that high and uniform expression of the vascular endothelial growth factor (VEGF) is observed only in the group undergoing dual mediation with electrical stimulation and MXenzyme. This observation indicates that the engineered wound dressing has the capability to accelerate healing in DFU. In human patient evaluations, the engineered dressing distinguishes vascular compliance and pulse period, enabling the diagnosis of arteriosclerosis and return blockage, two typical PVDs. The designed and engineered multiscale dressing achieves the purpose of integrating diagnostic peripheral vessel health monitoring and ulcer healing therapeutics for satisfying the practical clinical requirements of geriatric patients.

Potentially avoidable hospitalizations and associated factors among older people in French Guiana using the French National Health Data System.

Knowing the prevalence of potentially avoidable hospitalizations (PAHs) and the factors associated with them is essential if preventive action is to be taken. Studies on PAHs mainly concern adults, and very few have been carried out in South America. To the best of our knowledge, there has been no study on PAHs in French Guiana, particularly among older adults. This case-control study aimed to estimate the prevalence of PAHs in the Guianese population aged over 65 and to analyze their associated factors. We used the 2017-2019 data from the French National Health Service database (Système National des Données de Santé). The patients were age- and sex-matched 1 : 3 with controls without any PAH in 2019. Factors associated with PAHs were investigated through two conditional logistic regression models [one including the Charlson comorbidity index (CCI) and one including each comorbidity of the CCI], with calculation of the adjusted odds ratio (aOR) and 95% confidence interval (CI). The PAH incidence was 17.4 per 1000 inhabitants. PAHs represented 6.6% of all hospitalizations (45.6% related to congestive heart failure or hypertension). A higher CCI was associated with PAHs [aOR 2.2 (95% CI: 1.6, 3.0) and aOR 4.8 (95% CI: 2.4, 9.9) for 1-2 and ≥3 comorbidities, respectively, versus 0], as was immigrant health insurance status [aOR 2.3 (95% CI: 1.3, 4.2)]. Connective tissue disease, chronic pulmonary disease, congestive heart failure, diabetes, and peripheral vascular disease were comorbidities associated with an increased risk of PAHs. While the prevention of PAHs among immigrants is probably beyond the reach of the Guianese authorities, primary care and a public health policy geared toward prevention should be put in place for the French Guianese population suffering from cardiovascular disease in order to reduce PAHs.

Perivascular Adipose Tissue and Perivascular Adipose Tissue-Derived Extracellular Vesicles: New Insights in Vascular Disease.

Perivascular adipose tissue (PVAT) is a special deposit of fat tissue surrounding the vasculature. Previous studies suggest that PVAT modulates the vasculature function in physiological conditions and is implicated in the pathogenesis of vascular diseases. Understanding how PVAT influences vasculature function and vascular disease progression is important. Extracellular vesicles (EVs) are novel mediators of intercellular communication. EVs encapsulate molecular cargo such as proteins, lipids, and nucleic acids. EVs can influence cellular functions by transferring the carried bioactive molecules. Emerging evidence indicates that PVAT-derived EVs play an important role in vascular functions under health and disease conditions. This review will focus on the roles of PVAT and PVAT-EVs in obesity, diabetic, and metabolic syndrome-related vascular diseases, offering novel insights into therapeutic targets for vascular diseases.

A Review of Experimental Studies on Natural Chalcone-Based Therapeutic Targeting of Genes and Signaling Pathways in Type 2 Diabetes Complications.

Diabetes mellitus type 2 (T2DM) is a common chronic condition that presents as unsettled hyperglycemia (HG) and results from insulin resistance (IR) and β-cell dysfunction. T2DM is marked by an increased risk of microvascular and macrovascular complications, all of which can be the cause of increasing mortality. Diabetic nephropathy (DNE), neuropathy (DNU), and retinopathy (DR) are the most common complications of diabetic microangiopathy, while diabetic cardiomyopathy (DCM) and peripheral vascular diseases are the major diabetic macroangiopathy complications. Chalcones (CHs) are in the flavonoid family and are commonly found in certain plant species as intermediate metabolites in the biosynthesis of flavonoids and their derivatives. Natural CHs with different substituents exert diverse therapeutic activities, including antidiabetic ones. However, the therapeutic mechanisms of natural CHs through influencing genes and/or signaling pathways in T2DM complications remain unknown. Therefore, this review summarizes the existing results from experimental models which highlight the mechanisms of natural CHs as therapeutic agents for T2DM complications.

297 Exploring Risk Factors for Acute Kidney Injury in Patients Undergoing Cardiac Surgery

Abstract Aim Acute Kidney Injury (AKI) is an important complication following cardiac surgery that has been associated with adverse outcomes. The aim of this work was to investigate the incidence and risk factors for AKI in patients undergoing cardiac surgery at our centre. Method This is a retrospective analysis of 1441 patients who underwent elective or urgent (but not emergency) cardiovascular surgery with use of cardiopulmonary bypass over a 1-year period. Our exclusion criteria were heart transplant, single CABG, congenital repairs or patients on dialysis or renal transplant pre-operatively. Data analysis was performed in R studio. Results The mean age of the patients was 67.7 years. Mean creatinine from a 7-day period before surgery was 90µmol/L compared with the mean peak post operative creatinine of 127 µmol/L (95% CI 33-42, p-value &amp;lt;0.05). As defined by the KDIGO AKI stages, 27% developed an AKI stage 1, 11% developed AKI stage 2 and 1% AKI stage 3. The following variables correlated strongly (P-value &amp;lt;0.001) with post-operative risk of AKI: The comorbidities of diabetes, smoking, and peripheral vascular disease; pre-operative medications: diuretics, calcium channel blockers and SGLT-2 inhibitors and receiving FFP or RBC transfusion postoperatively. Conclusions AKI is a common complication following cardiac surgery. Having an insight into the risk factors for AKI allows an opportunity for intervention preoperatively and can also highlight patients that may require extra vigilance in the perioperative period to reduce its incidence, which may lead to an improvement in outcomes following surgery.

1141 Mortality and Re-Amputation Rates Following Below Knee Amputation: A Systematic Review and Meta-Analysis

Abstract Aim Below knee amputation (BKA) is undertaken in patients with diabetes or peripheral vascular disease, when limb sparing medical optimisation or vascular interventions are no longer feasible. Mortality and proximal re-amputation rates are poorly defined in the literature. We sought to perform a systematic review to examine mortality and reputation rates across the current literature. Method A systematic search was performed of the MEDLINE (via Pubmed), EMBASE, Cochrane and clinicaltrials.gov databases from inception to August 25th, 2022. Articles were screened by two independent reviewers with conflicts reserved by a third party. Inclusion criteria were all non-traumatic causes of lower limb amputation. Outcomes of interest included Mortality and occurrence of more proximal amputation. Results Studies from 12 countries encompassing a total of 41832 patients were included for analysis. Study dates ranged from 1987 to 2019. Of the total patient number, 38577 (92.2%) were from the USA, with 2599 (6.2%) from Europe and 656 (1.6%) remainder. The mean age at BKA was 70.46 years (Range 62-86). Weighted mortality was 37% (Range 4%-29%) at 1 year, 58% (Range 12% - 60%) at 2 years, 65% (range 19% - 81%) at 5 years and 84% (Range 71-96%) at 10 years. Five studies reported re-amputation rate at any time point (13% Range 1.16- 22%). Conclusions Mortality following BKA is still poor, even in contemporary studies. The few large multicentre studies are US based and in military veteran populations. More robust UK focused studies are needed to accurately inform clinical decision making for patients and clinicians.

Effectiveness of a Glyceryl Trinitrate (GTN) Patch in Preventing Amputation, Improving Pain Control and Reducing the Size of Tissue Loss for a Patient With Critical Limb-Threatening Ischaemia (CLTI).

Background Foot ulcer is a common complication of poorly controlled diabetes and peripheral vascular disease (PVD). The current standard of treatment for diabetic foot ulcers includes the management of underlying risk factors, wound debridement, use of antibiotics for infection, off-loading with cast, and revascularisation surgery. The glyceryl trinitrate (GTN) patch is currently off-licence in treating PVD or diabetic foot ulcers. This study aims to evaluate the effectiveness of the GTN patch in preventing amputation, improving pain control, and reducing the size of tissue loss (ulcer/gangrene) or localised ischaemic area. Method This is a pilot study of 30 patients who were started on the GTN patchfrom February 2020 to October 2021. Inclusion criteria were patients who have critical limb-threatening ischaemia (CLTI) and with no viable options or are at high risk for revascularisation, both endovascular and open surgery. Patients who were on a GTN patch for less than six weeks at the time of data collection or had unclear outcomes were excluded. The outcomes were retrospectively collected on prevention of amputation, improvement in pain control, and reduction in tissue loss (the size of ulcer/gangrene) or localised ischaemic area with the use of a GTN patch. The binomial test was used to compare the observed outcome of the GTN patch and the expected outcome, which was assumed to be 50% in this study. Results Ninety-three per cent (93%) of the patients who had GTN patches successfully avoided amputation (p<0.0001). Eighty-four per cent (84%) of patients reported better pain control (p=0.0022) and improvement in the size of ulcer/gangrene/localised ischaemic areas (p=0.0005). Conclusion The GTN patch is effective in preventing amputation, improving pain control, and reducing the size of ulcer/gangrene/localised ischaemic areas in patients who have end-stage CLTI and no viable options or who are at high risk for revascularisation surgery.

Long non-coding RNA PANDA drives diabetic vascular dysfunction by promoting endothelial senescence and oxidative damage

Abstract Funding Acknowledgements None. Background ROS and inflammation are major features of diabetic vasculopathy, yet the underlying mechanisms remain elusive. Long non-coding RNAs (lncRNAs) are emerging as important players in the pathogenesis of cardiovascular disease. Recent work has shown that PANDA, a newly identified lncRNA, is a key regulator of cellular senescence and apoptosis. Purpose To elucidate the role and molecular mechanism of lncRNA PANDA in diabetic vascular disease. Methods Human aortic endothelial cells (HAECs) were exposed to normal (NG, 5 mmol/L) and high glucose concentrations (HG, 25 mmol/L). PANDA depletion in HG-treated HAECs was obtained by siRNA transfection. Expression of PANDA was assessed by real time PCR. RNAs sequencing (RNA-seq) and bioinformatic analysis (network perturbation amplitude, NPA) were leveraged to unveil transcriptional changes upon PANDA depletion. PANDA RNA immuno-precipitation (RIP) was performed to check its binding to relevant transcriptional factor. Western Blots was used to investigate on NRF2 protein and its products. Beta-galactosidase staining was used to detect endothelial senescence while, migration and tube formation were employed to evaluate angiogenic properties of HAECs. ROS production and NRF2 localization were investigated by fluorescence staining. The ex vivo effect of PANDA siRNA on endothelial function was assessed in aortic rings from diabetic mice. Results PANDA expression was significantly increased in HAECs exposed to HG as compared to NG. Transcriptomic analysis revealed dysregulation of several genes upon PANDA silencing with the antioxidant gene heme oxygenase-1 as the top-ranking transcript in HG-treated cells (Fig). NPA analysis showed a strong involvement of PANDA in senescence, DNA damage, NRF2 signaling, hypoxic stress response and proliferation. Under HG conditions PANDA perturbed the pathway of the transcription factor NRF2, thus inhibiting the expression of NRF2-dependent pro-survival and anti-aging gene. Indeed, silencing of PANDA in HG-treated HAECs reduced the apotosis and senescence (Figure 1). PANDA depletion in HG improved endothelial migration and tube formation, while ROS production was reduced. In HG, there was an increasing of PANDA-NRF2 binding (Fig). Interesting, in HG NRF2 was more present in the cytosol, while PANDA siRNA allowed its translocation into the where it can promote the transcription of HMOX1. Of interest, PANDA levels were increased in aortas from diabetic mice while depletion of PANDA rescued endothelial dysfunction (Figure 2). Conclusions The hyperglycemia induced the upregulation of PANDA driving endothelial senescence and impairing angiogenic properties. PANDA depletion in HG-treated HAECs rescued maladaptive transcriptional changes enhancing NRF2 pathway. Of note, targeting PANDA in the diabetic vasculature was able to rescue endothelial dysfunction. These results indicate PANDA as a novel molecular target in the setting of diabetic vascular disease.

Nanozymes for the Therapeutic Treatment of Diabetic Foot Ulcers.

Diabetic foot ulcers (DFU) are chronic, refractory wounds caused by diabetic neuropathy, vascular disease, and bacterial infection, and have become one of the most serious and persistent complications of diabetes mellitus because of their high incidence and difficulty in healing. Its malignancy results from a complex microenvironment that includes a series of unfriendly physiological states secondary to hyperglycemia, such as recurrent infections, excessive oxidative stress, persistent inflammation, and ischemia and hypoxia. However, current common clinical treatments, such as antibiotic therapy, insulin therapy, surgical debridement, and conventional wound dressings all have drawbacks, and suboptimal outcomes exacerbate the financial and physical burdens of diabetic patients. Therefore, development of new, effective and affordable treatments for DFU represents a top priority to improve the quality of life of diabetic patients. In recent years, nanozymes-based diabetic wound therapy systems have been attracting extensive interest by integrating the unique advantages of nanomaterials and natural enzymes. Compared with natural enzymes, nanozymes possess more stable catalytic activity, lower production cost and greater maneuverability. Remarkably, many nanozymes possess multienzyme activities that can cascade multiple enzyme-catalyzed reactions simultaneously throughout the recovery process of DFU. Additionally, their favorable photothermal-acoustic properties can be exploited for further enhancement of the therapeutic effects. In this review we first describe the characteristic pathological microenvironment of DFU, then discuss the therapeutic mechanisms and applications of nanozymes in DFU healing, and finally, highlight the challenges and perspectives of nanozyme development for DFU treatment.

Abstract 3028: Diabetic Complication Ischemia Triggers Muscle Mass And Muscle Weight Loss By Reducing Mesenchymal Progenitor Cells Population Proliferation

Introduction: Mesenchymal progenitor cells (MPCs), such as myoblasts and fibroadipogenic progenitors (FAPs), and their communications with each other and with immune and vascular cells are responsible for muscle maintenance and regeneration. We hypothesize that in diabetes, loss of muscle mass after induction of hind limb ischemia is mediated by reduction in myoblast proliferation, thereby impairing muscle regeneration. Methods: Ischemic injury was induced in male diabetic (Akita) and littermate Wild Type (WT) mice via unilateral femoral artery ligation (FAL). Gastrocnemius muscle was collected at baseline, 3 and 7 days after surgery for single-cell RNA sequencing (scRNA seq). We identified the different cell populations in clusters, determined differentially-expressed genes, utilized Reactome Pathway Analysis and analyzed the cell cycle progression status and cell-cell interactions. Results: scRNA seq analysis of diabetic mice muscle, but not WT muscle, showed a reduction in MPCs, myoblasts and fibroadipogenic progenitors (FAPs) at 3 days post-FAL vs. baseline. FAPs were identified as two distinct subclusters; FAPs/Lum+ (associated with cell cycle regulation) and FAPs/Prg4+ (associated with extracellular matrix remodeling). We observed a lack of pathways involved in cell cycle progression in myoblasts at 3 days post- FAL in diabetic vs. WT muscle. At day 7 post-FAL, we observed an increased number of cell cycle pathways vs. day 3 post-FAL in diabetic muscle, implying a delayed response in the myoblasts. Cell cycle progression analysis revealed fewer diabetic myoblasts in S/G2M phase, with lower expression of proliferation markers (Mki67, Top2a, Mcm6 and Pcna), but no significant differences were observed in FAP/Lum+ cells. Cell-cell interaction analysis at day 3 post-FAL revealed fewer FAP-myoblast interactions in diabetic muscle, while interactions between either FAPs/myoblasts and myeloid cells were higher. Conclusion: These findings suggest that understanding the network of inter-cellular communications among MPCs, immune and vascular cells, and their roles in reduced myoblast proliferation after ischemia, is critical to identify new therapies to stimulate regeneration in diabetes and peripheral vascular disease.

Puerarin mitigated LPS-ATP or HG-primed endothelial cells damage and diabetes-associated cardiovascular disease via ROS-NLRP3 signalling.

The occurrence and development of diabetic vascular diseases are closely linked to inflammation-induced endothelial dysfunction. Puerarin (Pue), the primary component of Pueraria lobata, possesses potent anti-inflammatory properties. However, its vasoprotective role remains elusive. Therefore, we investigated whether Pue can effectively protect against vascular damage induced by diabetes. In the study, Pue ameliorated lipopolysaccharide-adenosine triphosphate (LPS-ATP) or HG-primed cytotoxicity and apoptosis, while inhibited reactive oxygen species (ROS)-mediated NLR family pyrin domain containing 3 (NLRP3) inflammasome in HUVECs, as evidenced by significantly decreased ROS level, NOX4, Caspase-1 activity and expression of NLRP3, GSDMD, cleaved caspase-1, IL-1β and IL-18. Meanwhile, ROS inducer CoCI2 efficiently weakened the effects of Pue against LPS-ATP-primed pyroptosis. In addition, NLRP3 knockdown notably enhanced Pue's ability to suppress pyroptosis in LPS-ATP-primed HUVECs, whereas overexpression of NLRP3 reversed the inhibitory effects of Pue. Furthermore, Pue inhibited the expression of ROS and NLRP3 inflammasome-associated proteins on the aorta in type 2 diabetes mellitus rats. Our findings indicated that Pue might ameliorate LPS-ATP or HG-primed damage in HUVECs by inactivating the ROS-NLRP3 signalling pathway.