Human Blood Vessels Research Articles

Two-photon 3D printed fiber-optic Fabry–Perot probe for triaxial contact force detection of guidewire tips

The demand for real-time feedback and miniaturization of sensing elements is a crucial issue in the treating vascular diseases with minimally invasive interventions. Here, Fabry–Perot microcavities fabricated via direct laser writing using a two-photon polymerization technique on fiber tips are proposed, designed, simulated, and experimentally demonstrated as a miniature triaxial force sensor for monitoring real-time interactions between the tip of a guidewire and human blood vessels and tissues during minimally invasive surgeries. The sensor contains four fiber tip-based Fabry–Perot cavities, which can be seamlessly integrated into medical guidewires and achieves three-axis force decoupling through symmetrically arranged flexible structures. The results showed that the proposed sensor achieved a cross-sectional diameter of 890 μm and a high sensitivity of about 85.16 nm/N within a range of 0 to 0.5 N with a resolution of hundreds of micro-Newtons. The proposed triaxial force sensor exhibits high resolution, good biocompatibility, and electromagnetic compatibility, which can be utilized as an efficient monitoring tool integrated into minimally invasive surgical intervention devices for biomedical applications.

Perioperative Outcomes: Polycarbonate Polyurethane Artificial Blood Vessel Versus Polyester Artificial Blood Vessel.

The objective of this study was to compare the perioperative performance of the novel large-diameter composite polycarbonate polyurethane graft and the polyester graft. In this study, we retrospectively analyzed 14 patients with thoracic aortic prosthesis replacement from 2016 to 2021. The preoperative, intraoperative, and postoperative data of the 2 groups were assessed in detail. We defined the patients with polyester grafts as the control group and the patients with polycarbonate polyurethane grafts as the experimental group. The total operation time of the experimental group was significantly shorter than that of the control group, which were 159.29±38.13 minutes and 252.57±64.40 minutes, respectively (p<0.001). The length of time from aortic opening to the end of operation in the experimental group was significantly shorter than that in the control group, which were 70.43±8.08 minutes and 124.71±37.59 minutes, respectively (p<0.001). The mean total drainage of pleural fluid was lower in the experimental group than in the control group (383.43±139.68 mL vs. 828.00±457.27 mL; p<0.05). The mean postoperative in-hospital time was shorter in the experimental group than in the control group (6.71±0.75 days vs. 9.43±2.82 days; p<0.05). This study provides preliminary evidence that the novel artificial blood vessel has good mechanical properties, histocompatibility, hemocompatibility, and anti-seepage function in the human body. A multicenter randomized controlled trial is needed for further validation. The novel hybrid polycarbonate polyurethane (PCU)/polyester three-layered large-diameter artificial blood vessel simulates the internal, middle, and external layers of the human blood vessels. The inner and outer layer are made of PCU, and the middle reinforcing layer is woven by polyester. Because of the three-layered structure, this artificial blood vessel has excellent anti-seepage and anti-infection functions. the inner and outer layers of the blood vessel made of PCU let this artificial blood vessel has excellent blood compatibility, outstanding biocompatibility, high endothelialization rate, and 100% patency. By comparing the perioperative outcomes with the polyester artificial blood vessel, we find it has good mechanical properties, histocompatibility, hemocompatibility and anti-seepage function in the human body.

Simulation and Experimental Study on Heat Transfer Performance of Bionic Structure-Based Battery Liquid Cooling Plate

This study presents a bionic structure-based liquid cooling plate designed to address the heat generation characteristics of prismatic lithium-ion batteries. The size of the lithium-ion battery is 148 mm × 26 mm × 97 mm, the positive pole size is 20 mm × 20 mm × 3 mm, and the negative pole size is 22 mm × 20 mm × 3 mm. Experimental testing of the Li-ion battery’s heat generation model parameters, in conjunction with bionic structure and micro-channel features, has led to the development of this innovative cooling system. The traditional bionic liquid cooling plate’s structure is often singular; however, the flow path of the liquid cooling plate designed in this paper is based on the combination of the distribution of human blood vessel branches and the structure of insect wing veins. The external dimension of the liquid cooling plate is 152 mm × 100 mm × 6 mm (length × width × height). Utilizing numerical simulation and thermodynamic principles, we analyzed the heat transfer efficacy of the bionic liquid cooling module for power batteries. Specifically, we investigated the impact of varying coolant flow rates and the contact radius between flow channels on the thermal performance of the bionic battery modules. Our findings indicate that a liquid flow rate of 0.6 m/s achieves a stable maximum surface temperature and temperature differential across the bionic battery liquid cooling module, with a relatively low overall system power consumption, suggesting room for further enhancement of heat transfer performance. By augmenting the contact radius between flow channels, we observed an initial increase in the maximum surface temperature, temperature differential, and inlet–outlet pressure differential at a flow rate of 0.2 m/s. However, at flow rates equal to or exceeding 0.4 m/s, these parameters stabilized across different design Scenarios. Notably, the pump power consumption remained consistent across various scenarios and flow rates. This study’s outcomes offer valuable insights for the development of liquid-cooled battery thermal management systems that are energy-efficient and offer superior heat transfer capabilities.

Spatial attention U-Net model with Harris hawks optimization for retinal blood vessel and optic disc segmentation in fundus images.

The state of the human eye's blood vessels is a crucial aspect in the diagnosis of ophthalmological illnesses. For many computer-aided diagnostic systems, precise retinal vessel segmentation is an essential job. However, it remains a difficult task due to the intricate vascular system of the eye. Although many different vascular segmentation techniques have already been presented, additional study is still required to address the problem of inadequate segmentation of thin and tiny vessels. In this work, we introduce the Spatial Attention U-Net (SAU-Net) modelwith harris hawks' optimization (HHO), a lightweight network that can be applied as a data augmentation technique to improve the efficiency of the existingannotated samples without the need of thousands of training instances for Retinal Blood Vessel and Optic Disc Segmentation. The SAU-Net-HHO implementation uses a spatially inferred attention map multiplied by the input feature map for adaptive feature enhancement. U-Net convolutional blocks have been replaced with structured dropout blocks in the proposed network to prevent overfitting. Data from both vascular extraction (DRIVE) and structured analysis of the retina (STARE) are used to evaluate SAU-Net-HHO performance. The results show that the proposed SAU-Net-HHO performs well on both datasets. Analysing the obtained results, an average of 98.5% accuracy and Specificity 96.7% was achieved for DRIVE dataset and 97.8% accuracy and specificity 94.5% for STARE dataset. The proposed method yields numerical results with average values that are on par with those of state-of-the-art methods. Visual inspection has revealed that the suggested method can segment thin and tiny vessels with greater accuracy than previous methods. It also demonstrates its potential for real-life clinical application.

Generation of human iPSC-derived 3D bile duct within liver organoid by incorporating human iPSC-derived blood vessel

In fetal development, tissue interaction such as the interplay between blood vessel (BV) and epithelial tissue is crucial for organogenesis. Here we recapitulate the spatial arrangement between liver epithelial tissue and the portal vein to observe the formation of intrahepatic bile ducts (BDs) from human induced pluripotent stem cells (hiPSC). We co-culture hiPSC-liver progenitors on the artificial BV consisting of immature smooth muscle cells and endothelial cells, both derived from hiPSCs. After 3 weeks, liver progenitors within hiPSC-BV-incorporated liver organoids (BVLO) differentiate to cholangiocytes and acquire epithelial characteristics, including intercellular junctions, microvilli on the apical membrane, and secretory functions. Furthermore, liver surface transplanted-BVLO temporarily attenuates cholestatic injury symptoms. Single cell RNA sequence analysis suggests that BD interact with the BV in BVLO through TGFβ and Notch pathways. Knocking out JAG1 in hiPSC-BV significantly attenuates bile duct formation, highlighting BVLO potential as a model for Alagille syndrome, a congenital biliary disease. Overall, we develop a novel 3D co-culture method that successfully establishes functional human BDs by emulating liver epithelial-BV interaction.

Modelling therapeutic responses to statins using iPSC-derived human blood vessel organoids

Modelling therapeutic responses to statins using iPSC-derived human blood vessel organoids

Physics-informed deep generative learning for quantitative assessment of the retina

Disruption of retinal vasculature is linked to various diseases, including diabetic retinopathy and macular degeneration, leading to vision loss. We present here a novel algorithmic approach that generates highly realistic digital models of human retinal blood vessels, based on established biophysical principles, including fully-connected arterial and venous trees with a single inlet and outlet. This approach, using physics-informed generative adversarial networks (PI-GAN), enables the segmentation and reconstruction of blood vessel networks with no human input and which out-performs human labelling. Segmentation of DRIVE and STARE retina photograph datasets provided near state-of-the-art vessel segmentation, with training on only a small (n = 100) simulated dataset. Our findings highlight the potential of PI-GAN for accurate retinal vasculature characterization, with implications for improving early disease detection, monitoring disease progression, and improving patient care.

Intelligent skin-removal photoacoustic computed tomography for human based on deep learning.

Photoacoustic computed tomography (PACT) has centimeter-level imaging ability and can be used to detect the human body. However, strong photoacoustic signals from skin cover deep tissue information, hindering the frontal display and analysis of photoacoustic images of deep regions of interest. Therefore, we propose a 2.5 D deep learning model based on feature pyramid structure and single-type skin annotation to extract the skin region, and design a mask generation algorithm to remove skin automatically. PACT imaging experiments on the human periphery blood vessel verified the correctness our proposed skin-removal method. Compared with previous studies, our method exhibits high robustness to the uneven illumination, irregular skin boundary, and reconstruction artifacts in the images, and the reconstruction errors of PACT images decreased by 20% ~ 90% with a 1.65 dB improvement in the signal-to-noise ratio at the same time. This study may provide a promising way for high-definition PACT imaging of deep tissues.

Precision improvement of robotic bioprinting via vision-based tool path compensation

Robotic 3D bioprinting is a rapidly advancing technology with applications in organ fabrication, tissue restoration, and pharmaceutical testing. While the stepwise generation of organs characterizes bioprinting, challenges such as non-linear material behavior, layer shifting, and trajectory tracking are common in freeform reversible embedding of suspended hydrogels (FRESH) bioprinting, leading to imperfections in complex organ construction. To overcome these limitations, we propose a computer vision-based strategy to identify discrepancies between printed filaments and the reference robot path. Employing error compensation techniques, we generate an adjusted reference path, enhancing robotic 3D bioprinting by adapting the robot path based on vision system data. Experimental assessments confirm the reliability and agility of our vision-based robotic 3D bioprinting approach, showcasing precision in fabricating human blood vessel segments through case studies. Significantly, it minimizes the printing layer width disparity to just 0.15 mm compared to the 0.6 mm in traditional methods, and it decreases the average error for curved filaments to 7.0 mm2 from the previous 12.7 mm2 in conventional printing. While these results underscore the significant potential of our innovation in creating precise biomimetic constructs, further investigation is necessary to tackle challenges such as accurately distinguishing closely stacked layers using a vision system, especially under varying lighting conditions. These limitations, coupled with issues of computational complexity and scalability in larger-scale bioprinting, emphasize the importance of enhancing the reliability of the vision-based approach across various conditions. Nonetheless, our innovation demonstrates substantial promise in creating precise biomimetic constructs and paves the way for future advancements in vision-guided robotic bioprinting, including the integration of multi-material printing techniques to enhance versatility.

Integrated transcriptomics of human blood vessels defines a spatially controlled niche for early mesenchymal progenitor cells

Human blood vessel walls show concentric layers, with the outermost tunica adventitia harboring mesenchymal progenitor cells. These progenitor cells maintain vessel homeostasis and provide a robust cell source for cell-based therapies. However, human adventitial stem cell niche has not been studied in detail. Here, using spatial and single-cell transcriptomics, we characterized the phenotype, potential, and microanatomic distribution of human perivascular progenitors. Initially, spatial transcriptomics identified heterogeneity between perivascular layers of arteries and veins and delineated the tunica adventitia into inner and outer layers. From this spatial atlas, we inferred a hierarchy of mesenchymal progenitors dictated by a more primitive cell with a high surface expression of CD201 (PROCR). When isolated from humans and mice, CD201Low expression typified a mesodermal committed subset with higher osteogenesis and less proliferation than CD201High cells, with a downstream effect on canonical Wnt signaling through DACT2. CD201Low cells also displayed high translational potential for bone tissue generation.

P-790 Engineering Vascularized Human Endometrial Organoids for In Vivo Tissue Regeneration and Repair Applications

Abstract Study question Is it possible to construct a vascularized endometrial organoid in vitro using endometrial epithelial organoids, endometrial stromal cells, and HUVECs? And its application value? Summary answer We have successfully engineered a vascularized endometrial organoid and demonstrated its remarkable ability to repair damaged endometrium. ScRNA-sequencing revealed intricate regulatory relationships among the cells. What is known already In vivo, endometrial epithelial organoids (EEOs) have been proven effective in repairing damaged endometrium. In vitro, when co-cultured with endometrial stromal cells (ESCs) in matrigel, EEOs self-assemble into endometrial assembloids that accurately replicate the native tissue’s characteristics. Endothelial cells play a critical regulatory role in various physiological processes across different tissues, such as lipid metabolism in hepatocytes, neurogenesis within the brain, and the menstrual cycle regulation in uterine endometrium. By leveraging organ-on-a-chip technology using HUVECs (commonly utilized endothelial cells), it is possible to construct functional and complex organoids with vascularization, including liver buds, brain organoids, and pancreatic islets. Study design, size, duration Different ratios of Fibrin and Matrigel were explored to optimize the hydrogel conditions. The composite medium was optimized with ExM and ECM. Cellular interactions were identified through cell-specific staining. Addition of reproductive hormones was performed to determine if the complexes exhibited hormone-responsive behavior. Transplantation of the organoid complexes into mice with endometrial injury was conducted to assess their repair capacity. Single-cell RNA sequencing was employed to identify cell clusters and analyze intercellular interactions. Participants/materials, setting, methods EEOs, ESCs, and HUVECs self-assemble into HEO complexes. EEOs and ESCs self-assemble into EO complexes as controls. Immunofluorescence and immunohistochemical analysis are conducted to detect cell-specific markers. PBS, Matrigel, EO and HEO complexes are transplanted into mice with endometrial injury. JC-1 staining and transmission electron microscopy are used to verify mitochondrial functionality. Electrical resistance measured by EVOM2, HUVEC tubule formation and sprouting assays are performed to investigate the formation of vascular networks within the complexes. Main results and the role of chance Under dynamic flow conditions of ExM and ECM at a ratio of 5:5, HEO complexes and EO complexes were self-assembled in a fibrin-matrigel hydrogel. The HEO complexes exhibited a capillary network-like structure, intricate cellular interactions, and a transcriptome profile similar to that of the in vivo endometrium. Moreover, HEO complexes responded to sex hormones, facilitating endometrial regeneration and improving the reproductive capacity of mice with endometrial injury. The subcutaneous transplantation of HEO complexes in mice revealed the perfusion of mouse blood within the human blood vessel network in the grafts, highlighting the participation of HUVECs in the vascular formation of the transplanted grafts. ScRNA sequencing analysis of HEO complexes demonstrated a notable rise in the proportion of proliferative subclusters of endometrial epithelial cells and stromal cells compared to EO complexes, especially under estrogen culture conditions. Additionally, HUVECs enhanced the mitochondrial functionality of endometrial cells and remodeled the extracellular matrix. Cell communication analysis revealed that endometrial epithelial and stromal cells enhance the formation of vascular networks in HUVECs within the HEO complexes through WNT7A and WNT5A signaling pathways. Limitations, reasons for caution Due to the time constraints of the study, we did not observe the birth rate of offspring mice following endometrial repair. ScRNA sequencing also uncovered that HUVECs promote ribosomal functionality in endometrial cells within HEO complexes, but further validation of this finding is necessary. Wider implications of the findings The implantation of HEO complexes derived from woman EEOs, ESCs, and HUVECs into the endometrium holds potential for “endometrial re-engineering” in the therapeutic management of Asherman’s syndrome or thin endometrium. Trial registration number not applicable

Zwitterionic modification: A strategy to enhance the mechanical properties, lubricity and hemo- and biocompatibility of silicone poly(carbonate urethane urea)

Incorporating zwitterions into the blood-contacting materials has been demon-strated an effective and convenient strategy to minimize protein adsorption and platelet deposition, but is frequently detrimental to the mechanical properties. Herein a feeding 29.0 mol% sulfobetaine (SB) siloxane poly(carbonate urethane urea) (SSiPCUU) was synthesized and evaluated. Although the equilibrium water uptake ratio was increased to 1.20% markedly depressing the hydrolytic degradation resistance and mechanical properties after the zwitterionic modification, its maximum tensile stress and tear strength in the wet state still kept the highest among all the tested samples because the urea groups created therefrom gave rise to the formation of bifurcating hydrogen bonds making a significant contribution to the mechanical properties alongside the unique ion clusters formed from pendant SB species. As a consequence of zwitterionic incorporation, it exhibited an extremely low friction coefficient indicating an excellent lubricity in a wet environment without any post-treatment. Accordingly, both the nonspecific protein adsorption and platelet adhesion were evidently decreased. Moreover, it also depicted a good transparency. The high lubrication performance is desirable for lessening the damage to human blood vessels and a good transparency is favorable to the visualization of the flow of liquid in the catheter. These results illustrated the great potential of the zwitterionic SSiPCUU used in the preparation of balloon catheters, artificial blood vessels, stent coverings and other blood-contacting medical implants and devices.

Vascular smooth muscle cells exhibit elevated hypoxia-inducible Factor-1α expression in human blood vessel organoids, influencing osteogenic performance

Considering the importance of alternative methodologies to animal experimentation, we propose an organoid-based biological model for in vitro blood vessel generation, achieved through co-culturing endothelial and vascular smooth muscle cells (VSMCs). Initially, the organoids underwent comprehensive characterization, revealing VSMCs (α-SMA + cells) at the periphery and endothelial cells (CD31+ cells) at the core. Additionally, ephrin B2 and ephrin B4, genes implicated in arterial and venous formation respectively, were used to validate the obtained organoid. Moreover, the data indicates exclusive HIF-1α expression in VSMCs, identified through various methodologies. Subsequently, we tested the hypothesis that the generated blood vessels have the capacity to modulate the osteogenic phenotype, demonstrating the ability of HIF-1α to promote osteogenic signals, primarily by influencing Runx2 expression. Overall, this study underscores that the methodology employed to create blood vessel organoids establishes an experimental framework capable of producing a 3D culture model of both venous and arterial endothelial tissues. This model effectively guides morphogenesis from mesenchymal stem cells through paracrine signaling, ultimately leading to an osteogenic acquisition phenotype, with the dynamic involvement of HIF-1α.

Anatomy of blood microcirculation in the pig epicardial ganglionated nerve plexus

Embolization of coronary arteries and their terminal arterioles causes ischemia of all tissues distributed within a cardiac wall including the intrinsic cardiac ganglionated nerve plexus (ICGP). The disturbed blood supply to the ICGP causes chronic sympathetic activation with succeeding atrial and ventricular arrhythmias. This study analyses the anatomy of microcirculation of epicardial nerves and ganglia using the hearts of 11 domestic pigs. Our findings demonstrate that thicker epicardial nerves are normally supplied with blood via 12 epineural arterioles penetrating the endoneurium regularly along a nerve, and forming an endoneurial capillary network, which drains the blood into the myocardial blood flow. The mean diameter of intraneural capillaries was 7.2 ± 0.2 µm, while the diameters of arterioles were 25.8 ± 0.7 μm and involved 45 endothelial cells accompanied by circular smooth muscle cells. Usually, two or three arterioles with a mean diameter of 28.9 ± 1.7 μm supplied blood to any epicardial ganglion, in which arterioles proceeded into a network of capillaries with a mean diameter of 6.9 ± 0.3 μm. Both the epicardial nerves and the ganglia distributed near the porta venarum of the heart had tiny arterioles that anastomosed blood vessels from the right and the left coronary arteries. The density of blood vessels in the epicardial nerves was significantly lesser compared with the ganglia. Our electron microscopic observations provided evidence that blood vessels of the pig epicardial nerves and ganglia may be considered as either arterioles or capillaries that have quantitative and qualitative differences comparing to the corresponding blood vessels in humans and, therefore, a pig should not be considered as an animal model of the first choice for further heart functional studies seeking to improve the treatment of cardiac arrhythmias via trans-coronary cardiac neuroablation. Structured abstractThis study details the anatomy of microcirculation of epicardial nerves and ganglia, from which intracardiac nerves and bundles of nerve fibers extend into all layers of the atrial and ventricular walls in the most popular animal model of experimental cardiology and cardiac surgery - the domestic pig. Our findings provided evidence that blood vessels of the pig epicardial nerves and ganglia may be considered as either arterioles or capillaries that have quantitative and qualitative differences comparing to the corresponding blood vessels in humans and, therefore, a pig should not be considered as an animal model of the first choice for further heart functional studies seeking to improve the treatment of cardiac arrhythmias via trans-coronary cardiac neuroablation.

Myocardin related transcription factor and galectin-3 drive lipid accumulation in human blood vessels

ObjectiveDiabetes and hypertension are important risk factors for vascular disease, including atherosclerosis. A driving factor in this process is lipid accumulation in smooth muscle cells of the vascular wall. The glucose- and mechano-sensitive transcriptional coactivator, myocardin-related transcription factor A (MRTF-A/MKL1) can promote lipid accumulation in cultured human smooth muscle cells and contribute to the formation of smooth muscle-derived foam cells. The purpose of this study was to determine if intact human blood vessels ex vivo can be used to evaluate lipid accumulation in the vascular wall, and if this process is dependent on MRTF and/or galectin-3/LGALS3. Galectin-3 is an early marker of smooth muscle transdifferentiation and a potential mediator for foam cell formation and atherosclerosis. Approach and resultsHuman mammary arteries and saphenous veins were exposed to altered cholesterol and glucose levels in an organ culture model. Accumulation of lipids, quantified by Oil Red O, was increased by cholesterol loading and elevated glucose concentrations. Pharmacological inhibition of MRTF with CCG-203971 decreased lipid accumulation, whereas adenoviral-mediated overexpression of MRTF-A had the opposite effect. Cholesterol-induced expression of galectin-3 was decreased after inhibition of MRTF. Importantly, pharmacological inhibition of galectin-3 with GB1107 reduced lipid accumulation in the vascular wall after cholesterol loading. ConclusionEx vivo organ culture of human arteries and veins can be used to evaluate lipid accumulation in the intact vascular wall, as well as adenoviral transduction and pharmacological inhibition. Although MRTF and galectin-3 may have beneficial, anti-inflammatory effects under certain circumstances, our results, which demonstrate a significant decrease in lipid accumulation, support further evaluation of MRTF- and galectin-3-inhibitors for therapeutic intervention against atherosclerotic vascular disease.

Novel Cardiovascular Stent Based on Hibiscus-Aestivation-Inspired Auxetic Unit Cell

Conventional stents have some limitations, such as dogboning and foreshortening, that can lead to issues like in-stent restenosis and thrombosis. Negative Poisson's ratio stents, called auxetic stents, are known as a solution to overcome these challenges due to their unique deformation mechanism. Auxetic stents are scale-independent, and their behavior depends solely on their geometry. In this study, a novel auxetic unit cell inspired by aestivation mechanism of the Hibiscus flower is designed, developed, and implemented in plane, and a tube to achieve a novel NPR cardiovascular stent. The stent structure is fabricated using two methods, including a novel 7-axis laser cut method capable of producing stents the same size as human blood vessels from an SS 316 L tube, and fused deposition modelling 3D printing at a scale 20 times larger than the metallic sample using PLA filaments. Novel laser cut effectively overcame some challenges in laser cutting stents, including HAZ and thermal shocks. SEM images are taken from the laser cut sample, and the manufacturing method's accuracy and surface quality are investigated. Fabricated metallic and polymeric stent samples proposed negative Poisson's ratio equal to 0.89 with an average of 4.38 and 14.8% errors, respectively, compared with finite element analysis. Finally, the structure's stress, strain energy distribution pattern, and unit cell distribution have been examined. Furthermore, the stent thickness parameter, drug release patch application, and stent implementation process are also investigated using FEM method. Proposed geometry in stent application showed solutions to conventional positive Poisson's ratio stent challenges.

Role of NaV1.7 in postganglionic sympathetic nerve function in human and guinea-pig arteries.

NaV1.7 plays a crucial role in inducing and conducting action potentials in pain-transducing sensory nociceptor fibres, suggesting that NaV1.7 blockers could be effective non-opioid analgesics. While SCN9A is expressed in both sensory and autonomic neurons, its functional role in the autonomic system remains less established. Our single neuron rt-PCR analysis revealed that 82% of sympathetic neurons isolated from guinea-pig stellate ganglia expressed NaV1.7 mRNA, with NaV1.3 being the only other tetrodotoxin-sensitive channel expressed in approximately 50% of neurons. We investigated the role of NaV1.7 in conducting action potentials in postganglionic sympathetic nerves and in the sympathetic adrenergic contractions of blood vessels using selective NaV1.7 inhibitors. Two highly selective NaV1.7 blockers, GNE8493 and PF05089771, significantly inhibited postganglionic compound action potentials by approximately 70% (P<0.01), with residual activity being blocked by the NaV1.3 inhibitor, ICA121431. Electrical field stimulation (EFS) induced rapid contractions in guinea-pig isolated aorta, pulmonary arteries, and human isolated pulmonary arteries via stimulation of intrinsic nerves, which were inhibited by prazosin or the NaV1 blocker tetrodotoxin. Our results demonstrated that blocking NaV1.7 with GNE8493, PF05089771, or ST2262 abolished or strongly inhibited sympathetic adrenergic responses in guinea-pigs and human vascular smooth muscle. These findings support the hypothesis that pharmacologically inhibiting NaV1.7 could potentially reduce sympathetic and parasympathetic function in specific vascular beds and airways. KEY POINTS: 82% of sympathetic neurons isolated from the stellate ganglion predominantly express NaV1.7 mRNA. NaV1.7 blockers inhibit action potential conduction in postganglionic sympathetic nerves. NaV1.7 blockade substantially inhibits sympathetic nerve-mediated adrenergic contractions in human and guinea-pig blood vessels. Pharmacologically blocking NaV1.7 profoundly affects sympathetic and parasympathetic responses in addition to sensory fibres, prompting exploration into the broader physiological consequences of NaV1.7 mutations on autonomic nerve activity.

Deletion of Sigmar1 leads to increased arterial stiffness and altered mitochondrial respiration resulting in vascular dysfunction.

Sigmar1 is a ubiquitously expressed, multifunctional protein known for its cardioprotective roles in cardiovascular diseases. While accumulating evidence indicate a critical role of Sigmar1 in cardiac biology, its physiological function in the vasculature remains unknown. In this study, we characterized the expression of Sigmar1 in the vascular wall and assessed its physiological function in the vascular system using global Sigmar1 knockout (Sigmar1-/-) mice. We determined the expression of Sigmar1 in the vascular tissue using immunostaining and biochemical experiments in both human and mouse blood vessels. Deletion of Sigmar1 globally in mice (Sigmar1-/-) led to blood vessel wall reorganizations characterized by nuclei disarray of vascular smooth muscle cells, altered organizations of elastic lamina, and higher collagen fibers deposition in and around the arteries compared to wildtype littermate controls (Wt). Vascular function was assessed in mice using non-invasive time-transit method of aortic stiffness measurement and flow-mediated dilation (FMD) of the left femoral artery. Sigmar1-/- mice showed a notable increase in arterial stiffness in the abdominal aorta and failed to increase the vessel diameter in response to reactive-hyperemia compared to Wt. This was consistent with reduced plasma and tissue nitric-oxide bioavailability (NOx) and decreased phosphorylation of endothelial nitric oxide synthase (eNOS) in the aorta of Sigmar1-/- mice. Ultrastructural analysis by transmission electron microscopy (TEM) of aorta sections showed accumulation of elongated shaped mitochondria in both vascular smooth muscle and endothelial cells of Sigmar1-/- mice. In accordance, decreased mitochondrial respirometry parameters were found in ex-vivo aortic rings from Sigmar1 deficient mice compared to Wt controls. These data indicate a potential role of Sigmar1 in maintaining vascular homeostasis.

Blood vessel organoids generated by base editing and harboring single nucleotide variation in Notch3 effectively recapitulate CADASIL-related pathogenesis.

Human blood vessel organoids (hBVOs) offer a promising platform for investigating vascular diseases and identifying therapeutic targets. In this study, we focused on in vitro modeling and therapeutic target finding of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most common form of hereditary stroke disorder caused by mutations in the NOTCH3 gene. Despite the identification of these mutations, the underlying pathological mechanism is elusive, and effective therapeutic approaches are lacking. CADASIL primarily affects the blood vessels in the brain, leading to ischemic strokes, migraines, and dementia. By employing CRISPR/Cas9 base-editing technology, we generated human induced pluripotent stem cells (hiPSCs) carrying Notch3 mutations. These mutant hiPSCs were differentiated into hBVOs. The NOTCH3 mutated hBVOs exhibited CADASIL-like pathology, characterized by a reduced vessel diameter and degeneration of mural cells. Furthermore, we observed an accumulation of Notch3 extracellular domain (Notch3ECD), increased apoptosis, and cytoskeletal alterations in the NOTCH3 mutant hBVOs. Notably, treatment with ROCK inhibitors partially restored the disconnection between endothelial cells and mural cells in the mutant hBVOs. These findings shed light on the pathogenesis of CADASIL and highlight the potential of hBVOs for studying and developing therapeutic interventions for this debilitating human vascular disorder.

Oxygenation heterogeneity facilitates spatiotemporal flow pattern visualization inside human blood vessels using photoacoustic computed tomography

Hemodynamics can be explored through various biomedical imaging techniques. However, observing transient spatiotemporal variations in the saturation of oxygen (sO2) within human blood vessels proves challenging with conventional methods. In this study, we employed photoacoustic computed tomography (PACT) to reconstruct the evolving spatiotemporal patterns in a human vein. Through analysis of the multi-wavelength photoacoustic (PA) spectrum, we illustrated the dynamic distribution within blood vessels. Additionally, we computationally rendered the dynamic process of venous blood flowing into the major vein and entering a branching vessel. Notably, we successfully recovered, in real time, the parabolic wavefront profile of laminar flow inside a deep vein in vivo—a first-time achievement. While the study is preliminary, the demonstrated capability of dynamic sO2 imaging holds promise for new applications in biology and medicine.