Diabetic Retinopathy (DR) is a leading cause of preventable blindness, and it is important to accurately detect it as early as possible, as well as to measure the severity to provide early clinical indicators. Fundus image assessment in the manual mode is subjective and labor-intensive, and is hard to scale, which has encouraged automated approaches. Current deep learning methods are usually based on either convolutional neural networks (CNNs) or transformer-based ones, focusing on local lesion features or global retina context separately. In addition, relational dependencies among lesions that are clinically significant in the case of severity development are under-modeled. This paper introduces a relational, hybrid deep learning model that integrates convolutional, transformer-based, and graph attention models to classify binary and multiclass DR. A ResNet-Graph Attention Network (ResNet-GAT) is introduced to explicitly model spatial relational dependencies among regional feature descriptors and iscompared with independent stand-alone ResNet-50 and Swin Transformer models. Also, a hybrid ResNet-Swin Transformer model combines fine-grained lesion representations and hierarchical global context. Experiments with the APTOS 2019 data show that the hybrid model has an accuracy of 98.09% with a Quadratic Weighted Kappa (QWK) of 0.9618 when used to classify binary, and 94.89% with a QWK of 0.9726 when used to classify five classes of severity. Robustness is proven by cross-dataset inference on IDRiD. The interpretability analysis performed through Grad-CAM shows that the predictions are made based on clinically significant areas, such as microaneurysms, hemorrhages, and exudates. It is demonstrated that performance and interpretability are enhanced by a combination of local, global, and relational representations in automated screening of DR.
PURPOSE:To quantify changes in retinal tissue oxygen saturation (StO₂) during systemic hypoxia assessed with ocular oximetry in healthy subjects. METHODS:Twenty healthy volunteers were studied in a prospective, single-site study. Retinal tissue StO₂ was measured at the optic nerve head (ONH) and the peripapillary retina using the Zilia Ocular device at baseline, during breathing of 12% oxygen in 88% nitrogen for 30 min (hypoxia), and after reoxygenation with ambient air for 30 min (recovery). Retinal blood flow was assessed with Laser Speckle Flowgraphy (mean blur rate, MBR), and capillary blood gas parameters were obtained from the arterialized earlobe. RESULTS:Gas breathing significantly reduced arterial oxygen saturation (SaO₂; from 97.1 ± 0.9% to 89.6 ± 2.5%, p < 0.001) and partial pressure of oxygen (pO₂; from 89.2 ± 6.6 mmHg to 56.4 ± 5.1 mmHg, p < 0.001) indicative of systemic hypoxia. StO₂ decreased significantly at both measurement sites during hypoxia (ONH: -6.3 ± 3.8%, p < 0.001; retina: -11.7 ± 13.4%, p < 0.001) and recovered following reoxygenation. Retinal blood flow indices (mean tissue MBR, mean area MBR, mean vessel MBR) increased significantly during hypoxia (all p < 0.01) and returned to baseline during recovery. CONCLUSION:Ocular oximetry with the Zilia Ocular detected consistent and reversible changes in retinal tissue oximetry during controlled systemic hypoxia. These findings, together with the expected compensatory increase in retinal blood flow, support the validity of the Zilia Ocular as a tool for non-invasive assessment of retinal tissue oxygenation and encourage its further evaluation as a potential biomarker in diseases characterized by altered retinal oxygen metabolism.
Blood coagulation is a complex physiological process governed by both biochemical and biomechanical mechanisms. While smoking, diabetes, and aging are established risk factors for thrombotic disorders, their combined interplay on shear-dependent coagulation behaviour remains poorly understood. This study investigates the effects of applied shear stress, smoking, diabetes, and age on blood coagulation using oscillatory rheometry to evaluate patient-specific haemostatic responses. Platelet-rich plasma (PRP) obtained from 30 volunteers representing healthy, smoker, and type 2 diabetic cohorts was analysed at 37 °C using an Anton Paar rheometer. Amplitude sweep experiments first established a linear viscoelastic region between 1 and 10 Pa, and subsequent rheological measurements were performed within a conservative stress range of 1-4 Pa. Time-to-gel point (TGP) was determined using the frequency-independent loss tangent criterion based on the Chambon-Winter gelation theory. Rheological findings were validated through conventional clotting time (CT) and prothrombin time (PT) measurements, while clot microstructure and platelet activation were further examined using field-emission scanning electron microscopy (FESEM) and fluorescence microscopy. A priori power analysis confirmed that the study was adequately powered to detect the observed intergroup differences. TGP decreased with increasing applied shear stress, demonstrating accelerated clot formation under higher mechanical loading. Compared with healthy controls, smokers and individuals with type 2 diabetes consistently exhibited shorter TGP, CT, and PT values, indicating enhanced coagulation potential. Older participants also demonstrated reduced TGP relative to younger healthy individuals, suggesting an age-related increase in procoagulant behaviour. FESEM revealed denser fibrin networks with reduced pore size at higher shear stresses, whereas fluorescence microscopy demonstrated increased CD62P expression, confirming progressive shear-induced platelet activation. These findings demonstrate that rheologically determined TGP is sensitive to both mechanical loading and underlying health status and, when complemented by structural and biological analyses, provides a quantitative marker for assessing patient-specific haemostatic function and thrombotic risk.
BACKGROUND/AIM:Assessment of foot microcirculation is increasingly implemented into clinical practice to assess vascular status and wound-healing potential in patients with vascular disease when conventional assessment techniques provide limited or unreliable information. Transcutaneous oxygen pressure (TcPO2) and laser speckle contrast imaging (LSCI) are techniques used to assess microcirculation in the foot. However, foot temperature is currently not considered during TcPO2 and LSCI measurements, despite substantial variation between patients and across measurements. Determining its influence is therefore crucial to ensure measurement reliability and reproducibility in clinical practice. This study aimed to determine the influence of foot temperature on TcPO2 and LSCI measurements. METHOD:Physiological foot temperatures ranging from 25 °C to 35 °C were simulated in 30 healthy participants using cold and warm water immersion. Subsequently, plantar LSCI perfusion and skin temperature measurements were obtained, together with dorsal TcPO2 and skin temperature measurements around the electrodes. RESULTS:TcPO2 and LSCI mean perfusion values differed significantly between foot temperatures of 25 °C and 35 °C, with higher temperatures yielding higher values for both techniques. Despite these clear differences, interindividual variability was seen and no consistent relation was observed between temperature changes and corresponding TcPO2 values. LSCI perfusion followed an exponential relation with foot temperature, but prediction intervals were wide. CONCLUSION:Foot temperature following water immersion significantly influences TcPO2 and LSCI measurements, although temperature responses vary between individuals. For TcPO2, this effect remained present despite local electrode heating, indicating that surrounding foot temperature continues to affect measurements. Clinicians should therefore consider foot temperature when interpreting TcPO2 and LSCI measurements.
OBJECTIVE:Juvenile idiopathic arthritis (JIA) is the most common chronic inflammatory rheumatic disease in children. This study aimed to evaluate nailfold videocapillaroscopy (NVC) findings in children with JIA, compare NVC findings across JIA subtypes, and assess their relationship with disease activity. METHODS:This prospective cross-sectional study included patients diagnosed with JIA according to the International League of Associations for Rheumatology (ILAR) classification criteria who attended routine outpatient clinic visits between October 2025 and December 2025. NVC following the EULAR microcirculation protocol. NVC parameters were compared across JIA subtypes and against age-matched healthy reference data. RESULTS:The study included 104 patients (51.9% male), of whom 84 (80.8%) had a nonspecific pattern. None of the patients demonstrated a scleroderma pattern. Reduced capillary density was observed in 60.6% of the patients. Tortuous and crossing capillaries were present in all patients, while giant capillaries were not detected. Abnormal shapes, dilated capillaries, and microhaemorrhages were observed in 44.2%, 32.7%, and 25% of patients, respectively. Dilated capillaries were nominally more common in RF-negative polyarticular JIA (p = 0.045), though not after correction for multiple comparisons (q = 0.096). In comparisons with age-specific reference values, patients with JIA were found to have lower capillary density (p < 0.001), arterial (p < 0.001), venous (p < 0.001), and loop diameters (p < 0.001), capillary length (p = 0.003). No statistically significant correlations were observed between NVC parameters and disease duration or disease activity scores (p > 0.05). CONCLUSION:This study demonstrated significant microvascular differences in the NVC of children with JIA. However, largely similar NVC findings across JIA subtypes suggest subtype-specific differences are limited.
PURPOSE:To evaluate retinochoroidal microvascular changes and their association with biochemical parameters in children with obesity. METHODS:This cross-sectional study included 100 children aged 6-15 years (50 obese, 50 normal weight). Retinal parameters superficial and deep capillary plexuses (SCP, DCP), choriocapillaris (CC), foveal avascular zone (FAZ), ganglion cell layer (GCL), and retinal nerve fiber layer (RNFL) were assessed using OCT and OCTA. Biochemical measures, including HDL, LDL, triglycerides, glucose, insulin, and blood pressure, were recorded. Associations between vascular density and biochemical variables were analyzed using regression analysis. RESULTS:Obese children showed a significantly smaller FAZ area than controls (262.11 ± 60.33 μm2 vs 316.47 ± 67.09 μm2, p < 0.001). RNFL thickness was significantly reduced in the central region (9.35 ± 5.51 μm vs 11.25 ± 4.65 μm, p = 0.041). GCL thickness was significantly lower in the temporal (81.55 ± 10.07 μm vs 87.42 ± 9.81 μm, p = 0.022) and inferior regions (85.73 ± 13.29 μm vs 92.69 ± 10.06 μm, p = 0.028). No significant differences were observed in SCP, DCP, or CC vessel densities. Foveal SCP and DCP vessel densities were negatively associated with systolic blood pressure and positively associated with HDL cholesterol. CONCLUSIONS:Childhood obesity is associated with FAZ reduction and thinning of retinal neural layers. Retinal microvascular findings may reflect the influence of vascular and metabolic risk factors in pediatric obesity.
Wet age-related macular degeneration (wAMD) is a leading cause of irreversible vision loss characterized by pathological choroidal neovascularization (CNV). While anti-VEGF therapies are the standard of care, limitations such as treatment resistance and side effects necessitate novel therapeutic agents. This study evaluates the therapeutic efficacy and mechanism of EV30, a novel pterostilbene derivative, in suppressing CNV. EV30 was synthesized based on the pterostilbene template. In vitro, the effects of EV30 on human umbilical vein endothelial cells (HUVECs) proliferation, migration, and tube formation were assessed using Cell Counting Kit-8 (CCK-8), scratch wound, and tube formation assays, respectively. Mechanistic pathways were investigated via Western blotting and RT-qPCR. In vivo, a laser-induced CNV mouse model was treated with intravitreal EV30. Efficacy was evaluated utilizing fundus photography, fluorescein angiography (FFA), optical coherence tomography (OCT), and choroidal flat mounts (IB4 staining). Finally, biosafety was assessed through histology (H&E), electroretinography (ERG), and blood analysis. EV30 demonstrated potent anti-angiogenic properties in vitro, significantly inhibiting HUVEC proliferation, migration, and tube formation in a dose- and time-dependent manner. EV30 reduced vascular endothelial growth factor A (VEGFA) expression and modulated the phosphorylation status of proteins associated with the mTOR/NF-κB/p38 MAPK signaling pathway. In the laser-induced CNV model, EV30 effectively reduced lesion area and vascular leakage comparable to bevacizumab. Furthermore, ERG analysis revealed that EV30 partially preserved retinal electrophysiological function, as indicated by improved scotopic a-wave amplitudes, suggesting functional protection of the retina in the CNV model. EV30 exerted anti-angiogenic effects and was associated with modulation of mTOR/NF-κB/p38 MAPK signaling activity. Together, these findings suggest that EV30 represents a potential therapeutic candidate for CNV by suppressing pathological angiogenesis and modulating inflammation-associated signaling pathways.
Exercise generates transient systemic redox and hemodynamic signals that influence oxygen delivery, vascular tone, and metabolic adaptation in both health and disease. Red blood cells (RBCs) are increasingly recognized as regulated redox-responsive cells rather than passive oxygen carriers. This narrative review integrates mechanistic and translational evidence linking RBC deformability, microvascular transit, and perfusion matching to exercise-induced reactive oxygen and nitrogen species (RONS), hemodynamic shear, hemoglobin redox cycling, antioxidant buffering, and nitric oxide (NO)-related signaling. RBC redox architecture, supported by glutathione and thioredoxin systems maintained by pentose phosphate pathway-derived nicotinamide adenine dinucleotide phosphate (NADPH), limits membrane lipid and protein damage during recurrent oxidative oscillations and restrains hemoglobin auto-oxidation. Exercise-induced changes in red blood cell nitric oxide synthase (RBC-NOS) activity, S-nitrosylation chemistry, nitrite reduction, and adenosine triphosphate (ATP)-mediated purinergic signaling may further influence NO bioavailability and downstream endothelial responses. However, severe, prolonged, unaccustomed, or insufficiently recovered oxidative stress may shift these adaptive responses toward methemoglobin accumulation, band-3 aggregation, vesiculation, phosphatidylserine-positive erythrocyte clearance, hemolysis, and impaired microvascular regulation. We therefore propose an intensity-duration-recovery framework in which moderate, transient, and adequately recovered redox/shear pulses support RBC deformability and microvascular adaptation, whereas prolonged or repeatedly performed high-intensity exercise may exceed erythrocyte buffering capacity and promote hemolytic injury or premature erythrocyte clearance. Because RBC redox dysfunction overlaps with cardiometabolic, vascular, hematological, and exercise-intolerance-related disease settings, standardized RBC-contained redox biomarkers may help improve the interpretation of exercise responses and support phenotype-aware exercise prescription.
AIMS:Heparin, a widely used anticoagulant in acute care, is known to interact with and modulate the endothelial glycocalyx (EG). This interference becomes particularly relevant in conditions such as sepsis, where microvascular dysfunction and endothelial degradation contribute substantially to organ failure. However, the immediate effects of heparin on microcirculatory parameters in humans remains insufficiently characterized. This study investigates the acute effects of heparin on microcirculation and EG integrity in-vivo using darkfield microscopic imaging. METHOD:This pre-postinterventional study includes 34 patients (mean age 11.8 ± 10.2 years; 53% female) who underwent cardiac catheterisation receiving a standardized heparin bolus. Before and 15 min after administration of heparin we measured sublingual microcirculation and EG using the GlycoCheck® (Version 5.2) system with Sidestream Dark Field (SDF) imaging. Red blood cell flow (RBC Flow), perfused microvessel density (PVD), capillary blood volume (CBV), and perfused boundary region (PBR), a surrogate for glycocalyx integrity, were assessed. RESULTS:Heparin administration was associated with a significant increase in PBR, indicating EG degradation and a concomitant reduction in PVD, while RBC Flow and CBV remained unchanged. These effects persisted after adjustment for systemic hemodynamic and respiratory changes and were independent of baseline hemoglobin, hematocrit and blood glucose levels. CONCLUSION:These findings provide insights into the short-term effects of heparin on EG integrity and microcirculation and highlight potential for unintended microvascular effects of heparin. Further studies are warranted to investigate drug-induced microvascular alterations and their long-term clinical consequences. CLINICAL TRIAL REGISTRATION:German Clinical Trials Register, DRKS00035631 https://www.drks.de/drks_web/.
In recent years, retinal vascular calibre has emerged as an important non-invasive biomarker of microvascular health, widely used in ophthalmology for the detection and monitoring of various ocular diseases and has attracted growing interest in the study of various systemic diseases. However, significant methodological questions remain regarding the precise number of vessels to include in the calculation, as well as the agreement between the two most widely used formulas for estimating the retinal vascular calibre: the Parr-Hubbard formula and the Knudtson formula. The aim of this study is to provide evidence regarding these issues by analysing the agreement between both formulas and evaluating the influence of the number of vessels included in the calculation of retinal vascular calibre: central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and the arteriovenous ratio (AVR). Bland-Altman analysis, the interclass correlation coefficient (ICC), and the Pearson coefficient were used to analyse the accuracy and reliability of the measurements for different number of vessels. The results indicate that the agreement between both formulas improves as the number of analysed vessels decreases. Reducing the number of vessels analysed affects the accuracy of the CRAE and CRVE parameters calculated with both formulas. In contrast, the AVR calculated using the Parr-Hubbard formula remains more stable, even though the reproduction coefficient (RPC) and limits of agreement (LOA) values increase as the number of analysed vessels decreases. Therefore, using six or five vessels is recommended; if fewer are analysed, diagnostic decisions should be supported by additional tests and indicators.
We noninvasively visualized the upper dermal microvasculature of 31 patients after hematopoietic cell transplantation (HCT) by reflectance confocal videomicroscopy. The microvessel diameter and number and diameter of adherent and rolling leukocytes for patients after HCT were similar to historically published values in healthy subjects. We also observed "paused" leukocytes i.e. leukocytes that temporarily stop, coinciding with the simultaneous stopping of the rest of the blood flow. The number and diameter of paused leukocytes, and the duration of leukocyte being paused for patients after HCT were also similar to historically published values in healthy subjects. However, we observed more blood vessels per imaging field of view (500 × 500 μm2) in the skin of patients after HCT than healthy subjects (a median of 3 versus 2). The number of blood vessels in a field of view was not correlated with the number of adherent and rolling leukocytes. Vessel size (flow width) had a meaningful correlation with the diameter, but not number, of paused leukocytes. Paused leukocyte diameter had no correlation with the duration of pausing. Reflectance confocal videomicroscopy enables characterization of intact upper dermal microvasculature of patients with extremely altered immune system.
Skin microvascular reactivity tests for the lower extremity apply stimuli such as ankle occlusion (post-occlusive reactive hyperemia, PORH), local heating (LH), or the vasoactive drug methyl nicotinate (MN). AIM:Evaluate microvascular reactivity in dorsal foot skin comparing PORH, LH and MN stimuli. METHOD:Thirty healthy participants 20-65 years of age were enrolled in a protocol using pointwise and imaging optical techniques for perfusion and oxygen saturation. Mean values and between-subjects coefficient of variation (CV) for perfusion and oxygen saturation were compared. RESULTS:The PORH, LH and MN stimuli caused significant increases in oxygen saturation and perfusion from baseline values (p < 0.001). The oxygen saturation was higher during LH than during PORH (pointwise technique; mean 88.8% vs 79.7%; p < 0.001) and higher during MN than during PORH (imaging; 86.7% vs 77.2%; p < 0.001). Perfusion was higher during LH than during PORH (pointwise; 1.60%RBC × mm/s vs 0.53%RBC × mm/s; p < 0.001) and higher during MN than during PORH (imaging; 1.04%RBC × mm/s vs 0.54%RBC × mm/s; p < 0.001). The CV for oxygen saturation was 2.8% vs 6.3% (pointwise; LH and PORH) and 7.4% vs 6.0% (imaging; MN and PORH). Corresponding values for perfusion were >30%. CONCLUSION:The responses in oxygen saturation and perfusion were higher during MN and LH stimuli than for PORH. A few outliers were observed after MN with a slower and lower response. Microcirculatory oxygen saturation has a lower between-subjects variation than perfusion (CV 3-7% vs >30%) during PORH, LH and MN stimuli.
INTRODUCTION:Ischemia-reperfusion (I/R) injury induces microvascular obstruction (MVO). The endothelial glycocalyx (eGC) is crucial for maintaining microvascular homeostasis. Fucoidan (FCD), a heparan sulfate mimetic, may protect the eGC. This study investigated whether FCD preserves the eGC and attenuates MVO following myocardial I/R. METHODS:Isolated rat hearts were perfused using a Langendorff apparatus and allocated to four groups: Sham (S), perfused with Krebs-Henseleit (KH) solution for 80 min; Sham + FCD (S + F), with FCD added during the final 40 min; I/R, consisting of 10 min perfusion, 30 min global no-flow ischemia, and 40 min reperfusion; and I/R + FCD (I/R + F), treated as I/R with FCD administered throughout reperfusion. RESULTS:FCD administration during reperfusion significantly reduced MVO compared with I/R alone. Transmission electron microscopy revealed preservation of the eGC in the I/R + F group. Pericapillary edema was significantly decreased with FCD treatment. Additionally, nitrite levels were significantly higher in the I/R + F group during both early and late reperfusion. CONCLUSION:FCD attenuates MVO after myocardial I/R injury by preserving the eGC, reducing pericapillary edema, and restoring nitric oxide bioavailability.
Aim To investigate the association between retinal microcirculation and cardiac function using optical coherence tomography angiography (OCTA). Methods In this cross-sectional study, 78 participants who underwent both OCTA and transthoracic echocardiography were included. OCTA was used to quantify vessel density (VD) and perfusion density (PD) in the optic disc region. Cardiac function parameters, including left ventricular ejection fraction (EF), mitral valve E wave (MV-E), and A wave (MV-A), were obtained via echocardiography. Correlation analyses and univariate and multivariable linear regression models were applied to evaluate associations between retinal microvascular metrics and cardiac function. Results Retinal VD and PD in all regions showed significant positive correlations with EF, indicating that better cardiac systolic function is associated with higher microvascular density and perfusion. MV-E, reflecting early diastolic function, was also positively correlated with inner and whole retinal VD and PD, whereas MV-A showed no significant association. Multivariable regression confirmed that EF and MV-E were independent positive determinants of whole VD and PD, while cerebrovascular disease was independently associated with reduced retinal microcirculation. Age demonstrated a negative association with VD. Conclusion Retinal microcirculation is closely linked to both systolic and diastolic cardiac function. OCTA-derived parameters, particularly VD and PD, may provide a non-invasive and quantitative approach for assessing systemic cardiovascular status and hold potential may serve as potential indicators of cardiovascular dysfunction.
Diabetic silent myocardial ischemia (DSMI) represents a clinically underappreciated yet life-threatening cardiovascular complication in which impaired myocardial perfusion occurs without recognisable symptoms. Two converging pathological axes underlie this phenotype: coronary microvascular dysfunction and neurocardiac signalling disruption. Chronic hyperglycaemia drives oxidative stress, advanced glycation end-product (AGE) accumulation, and mitochondrial dysfunction in endothelial and smooth-muscle cells, collectively impairing nitric oxide (NO) bioavailability, coronary flow reserve, and capillary integrity. Simultaneously, diabetic peripheral and autonomic neuropathy attenuates nociceptive transmission and disrupts neurovascular coupling, blunting the perception of ischaemic pain. At the molecular level, dysregulated insulin receptor (INSR), angiotensin II type 1 receptor (AT1R), toll-like receptor 4 (TLR4), AMP-activated protein kinase (AMPK), and transient receptor potential (TRP) channel signalling converge to perpetuate endothelial injury, vascular inflammation, and neural dysfunction. Critically, emerging evidence implicates mitochondrial reactive oxygen species (mtROS) overproduction, impaired mitochondrial biogenesis, and altered mitochondrial dynamics as shared mechanistic nodes linking both axes. This review synthesises current mechanistic knowledge within a novel unified framework, proposes candidate biomarkers including urinary 8-OHdG, NT-proBNP, heart rate variability indices, and coronary flow reserve by cardiac PET/CMR and identifies actionable therapeutic targets, including mitochondria-directed antioxidants (MitoQ, SS-31), SGLT2 inhibitors, GLP-1 receptor agonists, TLR4 antagonists, and TRPV1 modulators. Testable mechanistic hypotheses and directions for future translational research are proposed to accelerate early diagnosis and disease-modifying intervention in high-risk diabetic patients.
PURPOSE:Type 2 diabetes (T2D) and arterial hypertension are major cardiovascular risk factors, with endothelial dysfunction being a central pathological mechanism. This study investigated the concurrent T2D and arterial hypertension on plasma levels of endothelial glycocalyx components and inflammatory/vasoprotective markers. METHODS:In this cross sectional study, we assessed 68 individuals (44 female and 24 male) aged 41-69 years. Thirty-one individuals had T2D and thirty-seven had concurrent T2D and arterial hypertension. Anthropometry parameters and biomarkers profile were evaluated. Plasma syndecan-1, syndecan-4, hyaluronic acid, NFκB p65, and sirtuin 1 were measured using ELISA assay. RESULTS:Our findings revealed that individuals with coexisting hypertension and T2D exhibited significantly elevated hyaluronic acid (p = 0.013), syndecan-4 (p = 0.028), and NFκB p65 (p = 0.002), and markedly reduced sirtuin 1 (p = 0.007), compared to T2D-only participants. Effect size analysis showed moderate effect magnitudes for hyaluronic acid (Ƞ2p = 0.10), syndecan-4 (Ƞ2p = 0.10), NFκB p65 (Ƞ2p = 0.14), and sirtuin 1 (Ƞ2p = 0.11). In unadjusted analyses, sirtuin 1 was inversely correlated with hyaluronic acid (rho = -0.259; p = 0.033), syndecan-4 (rho = -0.307; p = 0.011), and NFκB p65 (rho = -0.276; p = 0.023), whereas hyaluronic acid was positively correlated with syndecan-4 (rho = 0.359; p = 0.003). After adjustment for diabetes duration, the associations of hyaluronic acid with syndecan-4 and of sirtuin 1 with NFκB p65 remained significant, whereas the correlations of sirtuin 1 with hyaluronic acid and syndecan-4 were no longer significant. CONCLUSION:Our results suggest that the coexistence of T2D and arterial hypertension is associated with unfavorable vascular biomarker profile, characterized by glycocalyx injury, greater inflammatory activation, and reduced vasoprotective signaling.
BACKGROUND AND AIMS:HDL biogenesis is mainly determined by intestinal and hepatic ABCA1. Inhibiting miR-10b increases macrophage ABCA1 but does not affect intestinal/hepatic ABCA1 or plasma HDL cholesterol in ApoE-/- mice. Given that miR-10a and miR-10b (with similar seed sequences) are comparably expressed in intestine/liver, we hypothesize they redundantly regulate intestinal/hepatic ABCA1 and HDL biogenesis. METHODS:Primary mouse enterocytes and hepatocytes were treated with antagonist miR-10a, antagonist miR-10b, or their combination, followed by systemic inhibition studies in ApoE-/- and C57BL/6 J mice. ABCA1 expression (qPCR/Western blot) and cholesterol efflux to ApoA-I/HDL were measured. Additionally, atherosclerotic lesions and HDL biogenesis in mice were assessed; ApoE-/- mice were further tested for intestinal barrier (intestinal permeability) and systemic inflammation (gut microbiota, inflammatory responses). RESULTS:Combined, not individual, miR-10a/b inhibition upregulated ABCA1 and increased cholesterol efflux in primary mouse enterocytes. Consistently, in ApoE-/- and wild-type C57BL/6J mice, combined miR-10 inhibition upregulated intestinal ABCA1, promoted HDL biogenesis, enhanced cholesterol efflux, and ultimately exerted anti-atherosclerotic effects. Concurrently, this dual inhibition reduced intestinal cholesterol accumulation, reshaped gut microbiota, and restored intestinal barrier integrity. Specifically, 16S rRNA sequencing shows that miR-10 inhibition decreased Proteobacteria (phylum level), while it increased Bacteroidetes (phylum level) and enriched Bifidobacterium and Lactobacillus (genus level). These effects collectively suppress systemic inflammation and exert anti-atherosclerotic effects in ApoE-/- mice. Additionally, miR-10 inhibition alleviated systemic inflammation in ApoE-/- mice by suppressing TLR4/NLRP3 inflammasome activation, with this suppression further verified in vitro. CONCLUSIONS:Inhibition of miR-10 attenuates atherosclerosis through enhanced intestinal ABCA1-mediated cholesterol efflux and barrier integrity, paralleling a favorable shift in gut microbiota composition particularly the enrichment of Bifidobacterium and Lactobacillus. This coordinated intestinal improvement reduces systemic inflammation and ultimately suppresses TLR4/NLRP3 inflammasome activation.
High-intensity interval exercise (HIIE) improves cardiorespiratory fitness through cardiac and skeletal muscle adaptations; however, the relationship between microvascular function and local skeletal muscle oxygenation during HIIE is unclear. Near-infrared spectroscopy at the vastus lateralis (∆ from baseline) was used to assess microvascular function pre- and post-HIIE and oxygenation throughout HIIE (n = 22 enrolled; n = 19 reported with complete oxygenation data, 27 ± 6 yrs., 42% female). HIIE consisted of twelve, 1-min intervals at 85% of peak power output while microvascular function was assessed using vascular occlusion-reperfusion. During HIIE, despite no change in the deoxygenation time constant tau (τ) (all p > 0.059), deoxygenation magnitude progressively increased at intervals 6 and 8 (both p < 0.011) and was greater at interval 11 compared to 1 (-49 ± 13 vs. -41 ± 19%, p = 0.033). Similarly, there was no change in the reoxygenation τ (all p > 0.753) while reoxygenation magnitude was immediately attenuated from interval 2 compared to 1 (-14 ± 18 vs. -6 ± 12%, p = 0.007) and was less at both intervals 6 and 11 compared to 1 (both p < 0.004). Microvascular function assessed as the 2-min hypersaturation area under the curve (AUC) was lower 15 min post- and 2 h post-HIIE compared to pre-exercise (both p ≤ 0.025), while the 10 s saturation upslope remained unchanged when controlling for the occlusion nadir (p = 0.212). The 2-min AUC (ρ = 0.659, p = 0.003) and 10 s upslope (r = 0.481, p = 0.043) correlated with peak cardiorespiratory fitness but were not related to reoxygenation outcomes (all p ≥ 0.113). These findings describe the acute oxygenation environment of HIIE while suggesting that sustained microvascular vasodilation may be lower post-HIIE.
Objectives This study aimed to establish a human iPSC-derived model of Moyamoya disease (MMD) by generating RNF213-knockdown vascular organoids to capture key disease-relevant vascular features. Methods RNF213-knockdown iPSC lines were established using lentiviral shRNA and selected with puromycin. Knockdown efficiency was validated by qRT-PCR and Western blot. Vascular organoids were differentiated from the engineered iPSCs using the STEMdiff™ Blood Vessel Organoid Kit according to the manufacturer's protocol. Organoids were analyzed by immunofluorescence for vascular markers (CD31, COL4A1, PDGFR-β, α-SMA) and transcriptomic profiling was performed using DRUG-seq. Results Three distinct RNF213-knockdown iPSC clones were successfully generated, exhibiting varying knockdown efficiencies. qPCR analysis demonstrated RNF213 mRNA reductions of approximately 22% (V1), 70% (V2), and 88% (V3), with corresponding decreases in protein levels confirmed by Western blot. Although V2 and V3 clones displayed more substantial molecular knockdown, organoids derived from the V1 clone manifested the most severe phenotypic abnormalities, characterized by disrupted CD31+ endothelial networks and Collagen IV+ basement membranes. Transcriptomic profiling identified 1543 differentially expressed genes, with enrichment analysis revealing significant dysregulation of angiogenesis-related pathways. This included marked upregulation of pro-angiogenic factors (CCL5, EREG) and downregulation of inhibitory factors (TNMD), effectively recapitulating key molecular features of Moyamoya disease. Conclusion We developed a novel human vascular organoid model with RNF-213 deficiency that captures key features of MMD vasculopathy, providing a valuable platform for mechanistic studies and drug screening.
The carotid body (CB) serves as the primary peripheral arterial chemoreceptor in mammals and plays a key role in the regulation of blood pressure by sensing changes in arterial blood gas levels and influencing sympathetic nerve activity. It is one of the most highly vascularized organs, with blood vessels occupying approximately 25% of its volume. Although hypertensive conditions are known to induce CB structural plasticity, detailed morphometric analysis of its vasculature remains limited. We performed a quantitative stereological study to assess microvascular remodeling in the CB of spontaneously hypertensive rats (SHR) compared to normotensive Wistar rats (NWR). High-resolution electron microscopy was used to visualize the vascular architecture of the hypertensive CB, and stereological techniques were applied to estimate the total length of its capillary network and the cross-sectional area of one capillary. We found that the total capillary length in the CB of SHR (10.66 ± 0.60 mm) is twice the one in NWR (5.36 ± 0.36 mm). Conversely, the average capillary cross-sectional area was significantly reduced in SHR (20.6 ± 1.14 μm2) versus NWR controls (57.80 ± 1.23 μm2), indicating a denser capillary network in the hypertensive CB. Our findings demonstrate pronounced microvascular remodeling in the hypertensive CB of rats, characterized by an elongated capillary network. Such changes reflect a hypervascular state that may facilitate enhanced chemoreflex sensitivity. This study provides quantitative evidence supporting the role of CB vasculature in hypertensive pathophysiology and highlights its potential as a target for therapeutic modulation.
