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Elizabethkingia miricola is a multidrug-resistant pathogen that can cause life-threatening infections in immunocompromised humans and outbreaks in amphibians. However, the specific virulence factors of this microorganism have not been described. In this study, we identified the polysaccharide biosynthesis protein-encoding gene capD, which is located in the conserved region of the Wzy-dependent capsule synthesis gene cluster in the E. miricola strain FL160902, and investigated its role in the pathogenesis of E. miricola. Our results revealed that the capD deletion strain (ΔcapD) lost its typical encapsulated structure, with a 45% reduction in cell wall thickness. CapD affects wza expression in the capsule polysaccharide synthesis pathway. Furthermore, the survival rates were significantly reduced in ΔcapD in response to complement-mediated killing, desiccation stress, and macrophage phagocytosis, whereas biofilm formation, surface hydrophobicity, and adherence to both endothelial and epithelial cells were increased. Additionally, the deletion of capD sharply attenuated the virulence of E. miricola in a frog infection model. Complementation of the capD gene restored the biological properties and virulence to wild-type levels. Overall, these findings suggest that CapD contributes to polysaccharide synthesis and plays a crucial role in the pathogenesis of E. miricola. [ABSTRACT FROM AUTHOR]

Fuchs Endothelial Corneal Dystrophy (FECD) is an aging disorder characterized by expedited loss of corneal endothelial cells (CEnCs) and heightened DNA damage compared to normal CEnCs. We previously established that ultraviolet-A (UVA) light causes DNA damage and leads to FECD phenotype in a non-genetic mouse model. Here, we demonstrate that acute treatment with chemical stressor, menadione, or physiological stressors, UVA, and catechol estrogen (4-OHE2), results in an early and increased activation of ATM-mediated DNA damage response in FECD compared to normal CEnCs. Acute stress with UVA and 4OHE2 causes (i) greater cell-cycle arrest and DNA repair in G2/M phase, and (ii) greater cytoprotective senescence in NQO1−/− compared to NQO1+/+ cells, which was reversed upon ATM inhibition. Chronic stress with UVA and 4OHE2 results in ATM-driven cell-cycle arrest in G0/G1 phase, reduced DNA repair, and cytotoxic senescence, due to sustained damage. Likewise, UVA-induced cell-cycle reentry, gamma-H2AX foci, and senescence-associated heterochromatin were reduced in Atm-null mice. Remarkably, inhibiting ATM activation with KU-55933 restored DNA repair in G2/M phase and attenuated senescence in chronic cellular model of FECD lacking NQO1. This study provides insights into understanding the pivotal role of ATM in regulating cell-cycle, DNA repair, and senescence, in oxidative-stress disorders like FECD. Inhibition of ATM in corneal endothelial cells restores DNA repair in G2/M phase of the cell cycle and attenuates senescence under chronic stress in FECD. [ABSTRACT FROM AUTHOR]

Research on keloid is limited by the lack of proper in vitro and animal model reflecting in vivo status. Based on heterogeneity of keloid and important role of endothelial cells in its pathogenesis, a novel 3D in vitro keloid spheroid prepared with keloid fibroblasts and endothelial cells was evaluated in this study. Commercial cell lines of keloid fibroblasts and endothelial cells were used at various cellular ratios to generate keloid spheroids to determine the optimal condition. Keloid spheroids from three keloid patients were also made and their usefulness as in vitro models, including their responses to drugs, were assessed. Spheroids with higher endothelial cell proportions exhibited increased viability and propagation ability. Patient-derived keloid spheroids showed heterogeneity which might reflect individual clinical conditions. The optimal ratio of fibroblasts to endothelial cells was determined to be 4:1 for keloid spheroids based on gene expression and viability analyses. Patient-derived keloid spheroid showed better keloidal changes in genetic expressions than 2D monolayer culture. Spheroids exhibited varied responses and resistance to each drug used for keloids, depending on the cell type used. 3D keloid spheroids might provide an effective in vitro model for investigating disease pathogenesis and appropriate treatment modalities for future precision medicine. 3D keloid spheroid model combining fibroblasts and endothelial cells demonstrated enhanced viability and reflected patient heterogeneity, offering a promising platform for studying keloid pathogenesis and advancing precision medicine. [ABSTRACT FROM AUTHOR]

Background: Intravascular papillary endothelial hyperplasia (Masson tumor) is a rare, benign vascular tumor characterized by the proliferation of endothelial cells within blood vessels. While it typically affects the skin and subcutaneous tissues, it can occasionally appear in unusual locations. Case presentation: We report a rare case of Masson tumor located in the right atrial appendage of a healthy individual. This case was complicated by atrial wall rupture and subsequent cardiac tamponade. The tumor was successfully resected under cardiopulmonary bypass. Conclusion: This case highlights a rare occurrence of Masson tumor in the heart, emphasizing the importance of prompt surgical intervention to prevent life-threatening complications such as cardiac tamponade. [ABSTRACT FROM AUTHOR]

Sterile inflammation occurs in various chronic diseases due to many nonmicrobe factors. Examples include endometrial hyperplasia (EH), endometriosis, endometrial cancer, and breast cancer, which are all sterile inflammation diseases induced by estrogen imbalances. However, how estrogen‐induced sterile inflammation regulates EH remains unclear. Here, a single‐cell RNA‐Seq is used to show that SHP2 upregulation in endometrial endothelial cells promotes their inflammatory activation and subsequent transendothelial macrophage migration. Independent of the initial estrogen stimulation, IL1β and TNFα from macrophages then create a feedforward loop that enhances endothelial cell activation and IGF1 secretion. This endothelial cell–macrophage interaction sustains sterile endometrial inflammation and facilitates epithelial cell proliferation, even after estradiol withdrawal. The bulk RNA‐Seq results and phosphoproteomic analysis show that endothelial SHP2 mechanistically enhances RIPK1 activity by dephosphorylating RIPK1Tyr380. This event activates downstream activator protein 1 (AP‐1) and instigates the inflammation response. Furthermore, targeting SHP2 using SHP099 (an allosteric inhibitor) or endothelial‐specific SHP2 deletion alleviates endothelial cell activation, macrophage infiltration, and EH progression in mice. Collectively, the findings demonstrate that SHP2 mediates the transition of endothelial activation from estradiol‐driven acute inflammation to macrophage‐amplified chronic inflammation. Targeting sterile inflammation mediated by endothelial cell activation is a promising strategy for nonhormonal intervention in estrogen‐related diseases. [ABSTRACT FROM AUTHOR]

The lack of representative in vitro models recapitulating human tendon (patho)physiology is among the major factors hindering consistent progress in the knowledge‐based development of adequate therapies for tendinopathy.Here, an organotypic 3D tendon‐on‐chip model is designed that allows studying the spatiotemporal dynamics of its cellular and molecular mechanisms.Combining the synergistic effects of a bioactive hydrogel matrix with the biophysical cues of magnetic microfibers directly aligned on the microfluidic chip, it is possible to recreate the anisotropic architecture, cell patterns, and phenotype of tendon intrinsic (core) compartment. When incorporated with vascular‐like vessels emulating the interface between its intrinsic‐extrinsic compartments, crosstalk with endothelial cells are found to drive stromal tenocytes toward a reparative profile. This platform is further used to study adaptive immune cell responses at the onset of tissue inflammation, focusing on interactions between tendon compartment tenocytes and circulating T cells.The proinflammatory signature resulting from this intra/inter‐cellular communication induces the recruitment of T cells into the inflamed core compartment and confirms the involvement of this cellular crosstalk in positive feedback loops leading to the amplification of tendon inflammation.Overall, the developed 3D tendon‐on‐chip provides a powerful new tool enabling mechanistic studies on the pathogenesis of tendinopathy as well as for assessing new therapies. [ABSTRACT FROM AUTHOR]

Piezo1 is a mechanically activated cation channel that converts mechanical force into diverse physiological processes. Owing to its large protein size of more than 2,500 amino acids and complex 38-transmembrane helix topology, how Piezo1 is post-translationally modified for regulating its in vivo mechanotransduction functions remains largely unexplored. Here, we show that PKA activation potentiates the mechanosensitivity and slows the inactivation kinetics of mouse Piezo1 and identify the major phosphorylation site, serine-1612 (S1612), that also responds to PKC activation and shear stress. Mutating S1612 abolishes PKA and PKC regulation of Piezo1 activities. Primary endothelial cells derived from the Piezo1-S1612A knockin mice lost PKA- and PKC-dependent phosphorylation and functional potentiation of Piezo1. The mutant mice show activity-dependent elevation of blood pressure and compromised exercise endurance, resembling endothelial-specific Piezo1 knockout mice. Taken together, we identify the major PKA and PKC phosphorylation site in Piezo1 and demonstrate its contribution to Piezo1-mediated physiological functions. [Display omitted] • Potentiation of Piezo1 channel activities by PKA- and PKC-mediated phosphorylation • Identification of S1612 in Piezo1 as the major PKA and PKC phosphorylation site • Endothelial Piezo1 is regulated by PKA and PKC phosphorylation at S1612 • S1612A knockin mice show alterations of blood pressure and exercise performance Zhang et al. discovered a conserved phosphorylation site, serine-1612, in Piezo1 that mediates PKA- and PKC-dependent phosphorylation and potentiation of the mechanically activated channel activities. Serine-1612 phosphorylation of endothelial Piezo1 regulates Piezo1-mediated in vivo mechanotransduction functions in controlling blood pressure homeostasis and exercise performance. [ABSTRACT FROM AUTHOR]

C-terminal Src kinase (Csk) targets Src family kinases (SFKs) and thereby inactivates them. We have previously shown that Csk binds to phosphorylated tyrosine 685 of VE-cadherin, an adhesion molecule of major importance for the regulation of endothelial junctions. This tyrosine residue is an SFK target, and its mutation (VE-cadherin-Y685F) inhibits the induction of vascular permeability in various inflammation models. Nevertheless, surprisingly, it increases leukocyte extravasation. Here, we investigated whether endothelial Csk is involved in these effects. We found that the deficiency of Csk in endothelial cells augments SFK activation and the phosphorylation of VE-cadherin-Y685 but had no net effect on vascular leak formation. In contrast, the lack of endothelial Csk enhanced leukocyte adhesion and transmigration in vitro and in vivo. Furthermore, the silencing of Csk increased tyrosine phosphorylation of the SFK substrate cortactin. Importantly, the effects of Csk silencing on the increase in SFK activation, cortactin phosphorylation, and neutrophil diapedesis were all dependent on Y685 of VE-cadherin. Deletion of cortactin, in turn, erased the supporting effect of Csk silencing on leukocyte transmigration. We have previously shown that leukocyte transmigration is regulated by endothelial cortactin in an ICAM-1-dependent manner. In line with this, blocking of ICAM-1 erased the supporting effect of Csk silencing on leukocyte transmigration. Collectively, our results establish a negative feedback loop that depends on the phosphorylation of VE-cadherin-Y685, which recruits Csk, which in turn dampens the activation of SFK and cortactin and thereby the clustering of ICAM-1 and the extravasation of neutrophils. [ABSTRACT FROM AUTHOR]

Background and aims: Dysfunction of endothelial cells represents a crucial aspect in the pathogenesis of atherosclerosis. The aim of this study was to explore the protective effects of alisol A on vascular endothelial cells and its possible mechanisms. Methods: An atherosclerosis model was established by feeding ApoE-/- mice with high-fat chow. Alisol A (150 mg/kg/d) or atorvastatin (15 mg/kg/d) was administered, and the levels of blood lipids were evaluated. The effect of the drugs on atherosclerotic plaques was observed by staining the aorta with Sudan IV. In vitro experiments were conducted using human aortic endothelial cells (HAECs) to assess the effects of alisol A on cell proliferation, migration, tubulation, secretion, and cellular integrity by CCK-8 assay, wound healing assay, angiogenesis assay, NO secretion, and release of LDH. Transcriptomics and molecular docking were used to explore the mechanism of plaque inhibition and stabilization by alisol A. Results: Alisol A significantly reduced the aortic plaque area in ApoE−/− mice fed with high-fat chow. In vitro , alisol A had a protective effect on HAECs, which was reflected in the inhibition of vascular endothelial cell proliferation, promotion of NO secretion by vascular endothelial cells, inhibition of vascular endothelial cell migration and angiogenesis, and the maintenance of cell membrane integrity. Therefore, alisol A inhibited and stabilized atherosclerotic plaques and slowed down the process of atherosclerosis. Transcriptomics studies showed 4,086 differentially expressed genes (DEGs) in vascular endothelial cells after alisol A treatment. Enrichment analysis indicated that many genes involved in TNF signaling pathway were differentially expressed, and inflammatory genes were suppressed. The molecular docking results verified the hypothesis that alisol A has a low binding energy after docking with TNF target, and TNF could be a potential target of alisol A. Conclusion: Alisol A produced protection on vascular endothelial cells, achieving inhibition and stabilization of atherosclerotic plaques. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pulmonary hypertension, characterized by vascular remodeling, currently lacks curative therapeutic options. The dysfunction of pulmonary artery endothelial cells plays a pivotal role in the initiation and progression of pulmonary hypertension (PH). ErbB3 (human epidermal growth factor receptor 3), also recognized as HER3, is a member of the ErbB family of receptor tyrosine kinases. METHODS: Microarray, immunofluorescence, and Western blotting analyses were conducted to investigate the pathological role of ErbB3. Blood samples were collected for biomarker examination from healthy donors or patients with hypoxic PH. The pathological functions of ErbB3 were further validated in rodents subjected to chronic hypoxia- and Sugen-induced PH, with or without adeno-associated virus-mediated ErbB3 overexpression, systemic deletion, or endothelial cell-specific ErbB3 knockdown. Primary human pulmonary artery endothelial cells and pulmonary artery smooth muscle cells were used to elucidate the underlying mechanisms. RESULTS: ErbB3 exhibited significant upregulation in the serum, lungs, distal pulmonary arteries, and pulmonary artery endothelial cells isolated from patients with PH compared with those from healthy donors. ErbB3 overexpression stimulated hypoxia-induced endothelial cell proliferation, exacerbated pulmonary artery remodeling, elevated systolic pressure in the right ventricle, and promoted right ventricular hypertrophy in murine models of PH. Conversely, systemic deletion or endothelial cell-specific knockout of ErbB3 yielded opposite effects. Coimmunoprecipitation and proteomic analysis identified YB-1 (Y-box binding protein 1) as a downstream target of ErbB3. ErbB3 induced nuclear translocation of YB-1 and subsequently promoted hypoxia-inducible factor 1/2α transcription. A positive loop involving ErbB3-periostin-hypoxia-inducible factor 1/2α was identified to mediate the progressive development of this disease. MM-121, a human anti-ErbB3 monoclonal antibody, exhibited both preventive and therapeutic effects against hypoxia-induced PH. CONCLUSIONS: Our study reveals, for the first time, that ErbB3 serves as a novel biomarker and a promising target for the treatment of PH. [ABSTRACT FROM AUTHOR]

Many withered leaves or flowers spontaneously curl and transform from flattened structures into tubular constructs upon dehydration. Inspired by this phenomenon, an innovative strategy is developed to design stimuli‐responsive scaffolds that are capable of programmable transformation from flattened 2D constructs into various curled 3D tissue‐mimicking structures. Specifically, Janus‐structured scaffolds consisting of a passive layer of polycaprolactone and an active, triggered‐transforming layer of methacrylate gelatin/alginate hydrogel are 3D‐printed, which replicate the asymmetrical structure of leaves and enabled on‐demand transformation into desired curvatures and shapes through mimicking the regulation mechanism of leaves curling behavior by mesophyll matrix stiffness and vein patterns. Particularly for vascular reconstruction, multi‐step transformation scaffolds capable of primary 2D‐to‐3D transformation into tubular constructs induced by dehydration, and secondary transformation to adapt to the local intravascular geometry in vivo, are successfully developed. In addition, the oriented polycaprolactone layer of the printed scaffold can enable the adhesion, proliferation, and orientation of endothelial cells, thus demonstrating a novel strategy for the design of tissue‐engineered blood vessels. In general, this study provides an innovative design strategy for programmable biomaterials capable of shape morphing and adaptation in physiological conditions, thereby opening up a new avenue for the design of intelligent biomaterials in regenerative medicine. [ABSTRACT FROM AUTHOR]

The maintenance of corneal transparency and normal vision is dependent on preservation of epithelial and endothelial cell layer homeostases. Different types of corneal injury can induce swelling and losses in transparency. Fuchs endothelial corneal dystrophy (FECD) is one type of injury that is commonly treated with rho‐associated coiled–coil‐containing protein kinase (ROCK) inhibitors. While their clinical benefit is apparent, certain aspects of their mechanism of action require clarification. Specifically, although topical eye drops containing ROCK inhibitors have been employed to treat corneal endothelial dysfunction–associated corneal edema, it remains unclear whether interactions between both corneal epithelial and endothelial cell contribute to mitigating clinical signs that compromise normal vision. To address this question, we first review the intricate ROCK signaling pathways and their role in modulating a variety of functions that are related to the maintenance of corneal transparency and normal vision. We also review the results of ongoing clinical trials employing current FDA‐approved ROCK inhibitors, highlighting the prominent role of Y‐27632 in the treatment of a variety of ocular conditions, particularly FECD, and its promising results in reversing losses in normal vision through facilitating cell proliferation and suppressing apoptosis. This review shows that the ROCK inhibitor clinical benefit is affected by their interactions between the epithelium and the endothelium. This realization makes it likely that ROCK inhibitors will be approved for use in a clinical setting to treat FECD. [ABSTRACT FROM AUTHOR]

ABSTRACT Kaposi sarcoma is a human herpesvirus 8–associated angio‐proliferative tumor arising from lymphatic endothelial cells. Four clinical subtypes are known: classic, epidemic, endemic, and iatrogenic. The development of Kaposi sarcoma and lymphedema may be interlinked, where each condition could potentially support the progression of the other. Post‐mastectomy lymphedema is a commonly recognized complication following radical mastectomy. Angiosarcoma is the most frequently reported neoplasm in such a situation. We present a 72‐year‐old female who developed Kaposi sarcoma on the same side of mastectomy 9 years following her initial diagnosis and treatment for cancer breast. The diagnosis of Kaposi sarcoma was based on the histopathologic findings and was confirmed with immunohistochemical staining for human herpes virus 8 and D2‐40. Lymphedema may be associated with local immune suppression manifested in the form of defective cell–mediated immunity and antigen‐presenting cell migration defect which may facilitate development of neoplasms. It is important to differentiate Kaposi sarcoma from other vascular tumors which may have a much worse prognosis. Patients with lymphedema should receive appropriate management and undergo long‐term follow‐up for early detection of any potential malignancies. [ABSTRACT FROM AUTHOR]

Background: Cell therapy has emerged as a revolutionary tool to repair damaged tissues by restoration of an adequate vasculature. Dental Pulp stem cells (DPSC), due to their easy biological access, ex vivo properties, and ability to support angiogenesis have been largely explored in regenerative medicine. Methods: Here, we tested the capability of Dental Pulp Stem Cell-Conditioned medium (DPSC-CM), produced in normoxic (DPSC-CM Normox) or hypoxic (DPSC-CM Hypox) conditions, to support angiogenesis via their soluble factors. CMs were characterized by a secretome protein array, then used for in vivo and in vitro experiments. In in vivo experiments, DPSC-CMs were associated to an Ultimatrix sponge and injected in nude mice. After excision, Ultimatrix were assayed by immunohistochemistry, electron microscopy and flow cytometry, to evaluate the presence of endothelial, stromal, and immune cells. For in vitro procedures, DPSC-CMs were used on human umbilical-vein endothelial cells (HUVECs), to test their effects on cell adhesion, migration, tube formation, and on their capability to recruit human CD14+ monocytes. Results: We found that DPSC-CM Hypox exert stronger pro-angiogenic activities, compared with DPSC-CM Normox, by increasing the frequency of CD31+ endothelial cells, the number of vessels and hemoglobin content in the Ultimatrix sponges. We observed that Utimatrix sponges associated with DPSC-CM Hypox or DPSC-CM Normox shared similar capability to recruit CD45− stromal cells, CD45+ leukocytes, F4/80+ macrophages, CD80+ M1-macrophages and CD206+ M2-macropages. We also observed that DPSC-CM Hypox and DPSC-CM Normox have similar capabilities to support HUVEC adhesion, migration, induction of a pro-angiogenic gene signature and the generation of capillary-like structures, together with the ability to recruit human CD14+ monocytes. Conclusions: Our results provide evidence that DPSCs-CM, produced under hypoxic conditions, can be proposed as a tool able to support angiogenesis via macrophage polarization, suggesting its use to overcome the issues and restrictions associated with the use of staminal cells. [ABSTRACT FROM AUTHOR]

Neuroblastoma (NB) is the most common solid extracranial neoplasm found in children and is derived from primitive sympathoadrenal neural precursor. The disease accounts for 15% of all cancer deaths in children. The mortality rate is high in patients presenting with a metastatic tumour even with extensive treatments. This signifies the need for further research towards the development of new additional therapies that can combat not only tumour growth but metastasis, especially amongst the high-risk groups. During metastasis, primary tumour cells become migratory and travel towards a capillary within the tumour. They then degrade the matrix surrounding the pericytes and endothelial cells traversing the endothelial barrier twice to establish a secondary. This led to the hypothesis that modulation of the endothelial cell junctional stability could have an influence on tumour metastasis. To test this hypothesis, agents that modulate endothelial permeability on NB cell line migration and invasion were assessed in vitro in a tissue culture model. The cAMP agonist and its antagonists were found to have no obvious effect on both SK-N-BE2C and SK-N-AS migration, invasion and proliferation. Next, NB cells were cocultured with HDMEC cells and live cell imaging was used to assess the effect of an Epac agonist on trans-endothelial cell migration of NB cells. Epac1 agonist remarkably reduced the trans-endothelial migration of both SK-N-BE2C and SK-N-AS cells. These results demonstrate that an Epac1 agonist may perhaps serve as an adjuvant to currently existing therapies for the high-risk NB patients. [ABSTRACT FROM AUTHOR]

Endothelial cells (ECs) not only form passive blood conduits but actively contribute to nutrient transport and organ homeostasis. The role of ECs in glucose homeostasis is, however, poorly understood. Here, we show that, in skeletal muscle, endothelial glucose transporter 1 (Glut1 /Slc2a1) controls glucose uptake via vascular metabolic control of muscle-resident macrophages without affecting transendothelial glucose transport. Lowering endothelial Glut1 via genetic depletion (Glut1 ΔEC) or upon a short-term high-fat diet increased angiocrine osteopontin (OPN/ Spp1) secretion. This promoted resident muscle macrophage activation and proliferation, which impaired muscle insulin sensitivity. Consequently, co-deleting Spp1 from ECs prevented macrophage accumulation and improved insulin sensitivity in Glut1 ΔEC mice. Mechanistically, Glut1- dependent endothelial glucose metabolic rewiring increased OPN in a serine metabolism-dependent fashion. Our data illustrate how the glycolytic endothelium creates a microenvironment that controls resident muscle macrophage phenotype and function and directly links resident muscle macrophages to the maintenance of muscle glucose homeostasis. [Display omitted] • EC-specific loss of Glut1 impairs insulin sensitivity in skeletal muscle • Angiocrine OPN controls resident macrophage phenotype and function • Resident macrophage accumulation and activation impair muscle insulin sensitivity • Endothelial glucose metabolic control of OPN is serine dependent Zhang et al. found that endothelial GLUT1 regulates muscle insulin sensitivity independently of transendothelial glucose transport. Lowering endothelial GLUT1 through genetic deletion or upon a short-term high-fat diet rewires endothelial glucose metabolism, thereby increasing angiocrine OPN secretion. This promotes resident macrophage accumulation and activation, which leads to muscle insulin resistance. [ABSTRACT FROM AUTHOR]

Introduction: Mitochondrial dysfunction and oxidative stress play important roles in diabetic retinal vascular injuries. Honokiol (HKL) is a small-molecule polyphenol that exhibits antioxidant effects and has a beneficial effect in diabetes. This study aimed to explore the potential ability of HKL to ameliorate vascular injury in diabetic retinopathy (DR) and its possible mechanisms of action. Methods: The effect of HKL was evaluated in vascular injury in an in vivo type 2 diabetic (db/db) mouse model. In vitro , retinal microvascular endothelial cells were treated with high glucose (HG) to simulate the pathological diabetic environment. Cell viability, expression of apoptosis-related proteins, cellular reactive oxygen species, mitochondrial membrane potential, and morphological changes in the mitochondria were examined. Results: The diabetic mice exhibited severe retinal vascular damage, including vascular leakage in vivo and capillary endothelial cell apoptosis in vitro. HKL reversed the retinal vascular leakage in the diabetic mice. In vitro , HKL improved retinal capillary endothelial cell viability, decreased apoptosis, and reversed the HG-induced increased cellular oxidative stress and mitochondrial fragmentation. The sirtuin 3 (SIRT3) inhibitor 3-TYP blocked all the in vivo and in vitro protective effects of HKL against diabetic retinal vascular leakage and capillary endothelium and eliminated the decrease in oxidative stress levels and reduction of mitochondrial fragmentation. Discussion: In conclusion, these findings suggest that HKL inhibits vascular injury in DR, which was likely achieved through SIRT3-mediated mitochondrial fusion. This study provides a potential new strategy for the treatment of DR. [ABSTRACT FROM AUTHOR]

The endothelial cells of the blood circulation are exposed to hemodynamic forces, such as cyclic strain, hydrostatic forces, and shear stress caused by the blood fluid's frictional force. Endothelial cells perceive mechanical forces via mechanosensors and thus elicit physiological reactions such as alterations in vessel width. The mechanosensors considered comprise ion channels, structures linked to the plasma membrane, cytoskeletal spectrin scaffold, mechanoreceptors, and junctional proteins. This review focuses on endothelial mechanosensors and how they alter the vascular functions of endothelial cells. The current state of knowledge on the dysregulation of endothelial mechanosensitivity in disease is briefly presented. The interplay in mechanical perception between endothelial cells and vascular smooth muscle cells is briefly outlined. Finally, future research avenues are highlighted, which are necessary to overcome existing limitations. [ABSTRACT FROM AUTHOR]

Objective To investigate effects of oxidized low density lipoprotein/β2 glycoprotein- I/anti- β2 glycoprotein-I antibody (oxLDL/β2GPI/aβ2GPI) complex on the proliferation, migration and angiogenesis of vascular endothelial cells and its mechanism. Methods Human umbilical vein endothelial cells (HUVEC) were cultured to logarithmic growth phase and grouped into the control group (normal culture), the oxLDL group (50 mg/L oxLDL), the oxLDL/ β2GPI/aβ2GPI group (50 mg/L oxLDL/100 mg/L β2GPI/100 mg/L aβ2GPI) and the VEGF group (100 µg/L VEGF). The gene expressions of VEGF, vascular endothelial cadherin (VE-cadherin), matrix metalloproteinase (MMP)-2 and MMP9 were detected by real-time quantitative fluorescent PCR (qPCR). Cell counting kit-8 (CCK-8) method was employed to detect cell proliferation. Cell migration and invasion were determined by scratch healing test and Transwell assay. Matrigel tube formation assay was used to observe the angiogenesis of HUVEC. The relative protein expression of TLR4, MyD88 and NF-κB were examined by Western blot assay. Results Compared with the control group, the proliferation activity of cells at 48 h of treatment was increased in the oxLDL/β2GPI/aβ2GPI group (P＜0.05). Moreover, compared with the control group, cell migration and angiogenesis were increased in the oxLDL/β2GP I/aβ2GP I group, and the mRNA levels of VEGF, VE-cadherin, MMP-2 and MMP-9 were elevated (P＜0.05). Compared with the control group, levels of TLR4 and MyD88 were elevated in the oxLDL/β2GPI/aβ2GPI complex group (P＜0.05), as well as levels of p-NF-κB p65/NF-κB p65 (P＜0.05). Conclusion oxLDL/β2GP I/aβ2GP I complex may promote the proliferation, migration and tube formation of vascular endothelial cells by regulating TLR4/MyD88/NF-κB signaling pathway. [ABSTRACT FROM AUTHOR]

The article discusses a case of a 34-year-old man with antiphospholipid syndrome (APS) who developed multiple subcutaneous nodules known as reactive angioendotheliomatosis (RAE). The patient had a history of pulmonary embolism and APS, with contrast-enhanced computed tomography revealing numerous subcutaneous nodules in his trunk and thighs. The histopathological features of the nodules were consistent with RAE, characterized by endothelial cell proliferation and fibrin thrombi within capillary-sized vessels. This case highlights the importance of considering RAE in patients with APS, even when skin changes are not present, and emphasizes the need for appropriate diagnostic tests and monitoring techniques. [Extracted from the article]

Endothelial progenitor cells (EPCs) are stem cells that can repair injured blood vessels through neovascularisation. This is achieved through secretion of growth factors and endothelial maturation. EPC numbers and function have been studied to determine their diagnostic, prognostic and therapeutic potential in many ischaemic diseases such as stroke. However their activation homing and migration is not definitively understood in stroke patients. In this study, we profiled the non-stroke control group recruited into the Dunhill Medical Trust Endothelial Progenitor Cell Study. Demographic, clinical and plasma levels of angiogenic regulators of participants were analysed to determine if there was any correlation with EPC numbers, subtypes and function. Participants with diabetes had significantly supressed EPC numbers (CD45-CD34 + CD133 + KDR+) and CD34 + KDR + and KDR + EPC subtypes. Male participants had significantly lower EPC numbers compared to female participants and the proliferative capacity of endothelial colony forming cells significantly decreased with increasing participant age. Pro-angiogenic proteins such as granulocyte colony-stimulating factor and stromal cell-derived factor were positively correlated with both undifferentiated and endothelial-committed EPC subtype numbers (CD133+, KDR+, CD34 + CD133+, CD34 + KDR+), whereas anti-angiogenic proteins such as thrombospondin-1 showed a negative correlation with undifferentiated EPC subtypes (CD133+, CD34 + CD133+) but a positive correlation with endothelial-committed EPC subtype numbers (KDR+, CD34 + KDR+). These results show that EPC numbers and subtypes are affected by many factors and larger studies which can analyse and deconvolute the interactions between comorbidities, plasma biomarker levels and EPC are needed. [ABSTRACT FROM AUTHOR]

Placental‐derived stromal‐like cells (PLX‐PAD) have been shown to facilitate muscle tissue recovery after injury and stimulate angiogenesis. This work assesses the impact of PLX‐PAD cells on the vascularization and maturation of engineered skeletal muscle tissue. Specifically, their effects in direct co‐culture with endothelial cells, pericytes, and myoblasts seeded within microporous 3D scaffolds are characterized. Additionally, the impact of hypoxic PLX‐PAD cell‐conditioned medium (CM) on vascularization and muscle differentiation of engineered tissue is monitored. Co‐culture of PLX‐PAD with myocytes stimulated myocyte differentiation while PLX‐PAD CM promoted the formation of vascular networks. Implantation of a multi‐culture system of vascularized human skeletal muscle tissue and PLX‐PAD into a rectus abdominal defect in nude mice promoted myocyte differentiation, host vessel penetration, and tissue integration. These findings indicate the ability of placenta‐derived cells to induce the formation of vascularized engineered muscle constructs with potential therapeutic applications. [ABSTRACT FROM AUTHOR]

Objective: Neovascularization has been extensively studied because of its significant role in both physiological processes and diseases. The significance of vascular microfluidic platforms lies in its essential role in recreating an in vitro environment capable of supporting cellular and tissue systems through the process of neovascularization. Biomechanical properties in a tissue engineered system use fluid flow and transport properties to recapitulate physiological systems. This enables mimicry of organ systems which can further personalized and regenerative medicine. Thus, fluid hemodynamics can be used to study these flow patterns and create a system that mimics real physiological pathways and processes. The establishment of stable flow pathways encourages endothelial cells (ECs) ECs to undergo neovascularization. Specifically, the shear stress applied in capillary beds generates the increased proliferation and differentiation of ECs to build larger microcirculatory beds. Mathematical Framework: Here, we describe a mathematical model that uses branching patterns and vessel morphology to predict hemodynamic parameters in capillary beds. Results: A retinal capillary bed is used as one‐use case of our model to show how the mathematical framework can be used to determine hemodynamic parameters for any microfluidic system. Conclusion: In doing so, this tool can be altered to be used to supplement emerging research areas in neovascularization. [ABSTRACT FROM AUTHOR]

Purpose: Highly complex tumor microenvironment makes hepatocellular carcinoma (HCC) as one of the most malignant tumors worldwide. The role of cellular senescence in HCC has been gradually recognized. The present study aimed to comprehensively elucidate the senescence-related features of HCC in single-cell and spatial dimension. Methods: Single-cell RNA sequencing (scRNA-Seq) data was used to clarify the heterogeneity of senescence-related genes (SRGs) among multiple cell types within HCC. Spatial transcriptome RNA sequencing (stRNA-Seq) data was used for depicting SRGs features in spatial dimension. A prognostic model based on SRGs was constructed by using of bulk sequencing (bulk-Seq) data of HCC. The cell-cell interaction of senescent endothelial cells (ECs) in tumor microenvironment was analyzed. Then, the role of senescent ECs was verified through in vitro and in vivo experiments. Results: The level of senescence demonstrated substantial heterogeneity among different cell types within tumor microenvironment of HCC, where ECs exhibited the most prominent senescent phenotype. Senescent ECs activated specific regulatory pathways through communicating with other cell types, with a potential impact on tumor progression. Spatial analysis revealed senescent ECs mainly located in the core region of HCC. The interaction of senescent ECs and immune cells implicated their role in tumor progression and immunotherapeutic response. In addition, CDKN2A was identified as an independent risk factor for HCC prognosis by constructing a prognostic model. Patients with high risk displayed an even worse outcome. The experimental verification indicated senescence of ECs determined by CDKN2A exhibited a secretory phenotype. Furthermore, senescent ECs with CDKN2A overexpression promote the proliferation and migration of HCC. Conclusion: The present study recognizes the critical effect of senescent ECs defined by CDKN2A in the promotion of tumor progression, which sheds new light on the investigation of ECs senescence in HCC. [ABSTRACT FROM AUTHOR]

Myocardial infarction (MI) is a critical global health issue and a leading cause of heart failure. Indeed, while neonatal mammals can regenerate cardiac tissue mainly through cardiomyocyte proliferation, this ability is lost shortly after birth, resulting in the adult heart's inability to regenerate after injury effectively. In adult mammals, the adverse cardiac remodelling, which compensates for the loss of cardiac cells, impairs cardiac function due to the non-contractile nature of fibrotic tissue. Moreover, the neovascularisation after MI is inadequate to restore blood flow to the infarcted myocardium. This review aims to synthesise the most recent insights into the molecular and cellular players involved in endogenous myocardial and vascular regeneration, facilitating the identification of mechanisms that could be targeted to trigger cardiac regeneration, reduce fibrosis, and improve functional recovery post-MI. Reprogramming adult cardiomyocytes to regain their proliferative potential, along with the modulation of target cells responsible for neovascularisation, represents promising therapeutic strategies. An updated overview of endogenous mechanisms that regulate both myocardial and coronary vasculature regeneration—including stem and progenitor cells, growth factors, cell cycle regulators, and key signalling pathways—could help identify new critical intervention points for therapeutic applications. [ABSTRACT FROM AUTHOR]

Neointimal hyperplasia is the main cause of vascular graft failure in the medium term. NFκB is a key mediator of inflammation that is activated during neointimal hyperplasia following endothelial injury. However, the molecular mechanisms involved in NFκB activation are poorly understood. NFκB may be activated through canonical (transient) and non-canonical (persistent) pathways. NFκB-inducing kinase (NIK, MAP3K14) is the upstream kinase of the non-canonical pathway. We have now explored the impact of NIK deficiency on neointimal hyperplasia following guidewire-induced endothelial cell injury and on local inflammation by comparing NIK activity–deficient alymphoplasia mice (NIKaly/aly) with control wild-type (NIK+/+) mice. Guidewire-induced endothelial cell injury caused neointimal hyperplasia and luminal stenosis and upregulated the local expression of NIK and the NFκB target chemokines monocyte chemoattractant protein-1 (MCP-1/CCL2) and chemokine ligand 5 (RANTES/CCL5). Immunohistochemistry disclosed the infiltration of the media and intima by F4/80 positive macrophages. The intima/media ratio and percentage of stenosis were milder in the NIKaly/aly than in the NIK+/+ mice. Additionally, the gene expression for MCP-1 and RANTES was lower and F4/80+ cell infiltration was milder in the NIKaly/aly than in the NIK+/+ mice. Finally, circulating MCP-1 levels were lower in the NIKaly/aly than in the NIK+/+ mice, reflecting milder systemic inflammation. In conclusion, NIK is a driver of vascular wall inflammation and stenosis following guidewire-induced endothelial cell injury. NIK targeting may be a novel therapeutic approach to limit arterial stenosis following endothelial cell injury. [ABSTRACT FROM AUTHOR]

Calciprotein particles (CPPs) are essential circulating scavengers of excessive Ca2+ and PO43− ions, representing a vehicle that removes them from the human body and precludes extraskeletal calcification. Having been internalised by endothelial cells (ECs), CPPs induce their dysfunction, which is accompanied by a remarkable molecular reconfiguration, although little is known about this process's extracellular signatures. Here, we applied ultra-high performance liquid chromatography-tandem mass spectrometry to perform a secretome-wide profiling of the cell culture supernatant from primary human coronary artery ECs (HCAECs) and internal thoracic artery ECs (HITAECs) treated with primary CPPs (CPP-P), secondary CPPs (CPP-S), magnesiprotein particles (MPPs), or Ca2+/Mg2+-free Dulbecco's phosphate-buffered saline (DPBS) for 24 h. Incubation with CPP-P/CPP-S significantly altered the profiles of secreted proteins, delineating physiological and pathological endothelial secretomes. Neither pathway enrichment analysis nor the interrogation of protein–protein interactions detected extracellular matrix- and basement membrane-related molecular terms in the protein datasets from CPP-P/CPP-S-treated ECs. Both proteomic profiling and enzyme-linked immunosorbent assay identified an increased level of protectin (CD59) and reduced levels of osteonectin (SPARC), perlecan (HSPG2), and fibronectin (FN1) in the cell culture supernatant upon CPP-P/CPP-S treatment. Elevated soluble CD59 and decreased release of basement membrane components might be considered as potential signs of dysfunctional endothelium. [ABSTRACT FROM AUTHOR]

Pulmonary artery endothelial cells (PAECs) are a major contributor to hypoxic pulmonary hypertension (PH) due to the possible roles of reactive oxygen species (ROS). However, the molecular mechanisms and functional roles of ROS in PAECs are not well established. In this study, we first used Amplex UltraRed reagent to assess hydrogen peroxide (H2O2) generation. The result indicated that hypoxic exposure resulted in a significant increase in Amplex UltraRed-derived fluorescence (i.e., H2O2 production) in human PAECs. To complement this result, we employed lucigenin as a probe to detect superoxide (O2−) production. Our assays showed that hypoxia largely increased O2− production. Hypoxia also enhanced H2O2 production in the mitochondria from PAECs. Using the genetically encoded H2O2 sensor HyPer, we further revealed the hypoxic ROS production in PAECs, which was fully blocked by the mitochondrial inhibitor rotenone or myxothiazol. Interestingly, hypoxia caused an increase in the migration of PAECs, determined by scratch wound assay. In contrast, nicotine, a major cigarette or e-cigarette component, had no effect. Moreover, hypoxia and nicotine co-exposure further increased migration. Transfection of lentiviral shRNAs specific for the mitochondrial Rieske iron–sulfur protein (RISP), which knocked down its expression and associated ROS generation, inhibited the hypoxic migration of PAECs. Hypoxia largely increased the proliferation of PAECs, determined using Ki67 staining and direct cell number accounting. Similarly, nicotine caused a large increase in proliferation. Moreover, hypoxia/nicotine co-exposure elicited a further increase in cell proliferation. RISP knockdown inhibited the proliferation of PAECs following hypoxia, nicotine exposure, and hypoxia/nicotine co-exposure. Taken together, our data demonstrate that hypoxia increases RISP-mediated mitochondrial ROS production, migration, and proliferation in human PAECs; nicotine has no effect on migration, increases proliferation, and promotes hypoxic proliferation; the effects of nicotine are largely mediated by RISP-dependent mitochondrial ROS signaling. Conceivably, PAECs may contribute to PH via the RISP-mediated mitochondrial ROS. [ABSTRACT FROM AUTHOR]

Preeclampsia (preE) is a hypertensive disorder in pregnancies. It is the third leading cause of mortality among pregnant women and fetuses worldwide, and there is much we have yet to learn about its pathophysiology. One complication includes cerebral edema, which causes a breach of the blood–brain barrier (BBB). Urinary marinobufagenin (MBG) is elevated in a preE rat model prior to developing hypertension and proteinuria. We investigated what effect MBG has on the endothelial cell permeability of the BBB. Human brain microvascular endothelial cells (HBMECs) were utilized to examine the permeability caused by MBG. The phosphorylation of ERK1/2, Jnk, p38, and Src was evaluated after the treatment with MBG. Apoptosis was evaluated by examining caspase 3/7. MBG ≥ 1 nM inhibited the proliferation of HBMECs by 46–50%. MBG induced monolayer permeability, causing a decrease in the phosphorylation of ERK1/2 and the activated phosphorylation of Jnk, p38, and Src. MBG increased the caspase 3/7 expression, indicating the activation of apoptosis. Apoptotic signaling or the disruption of endothelia tight junction proteins was not observed when using the p38 inhibitor as a pretreatment in MBG-treated cells. The MBG-induced enhancement of the HBMEC monolayer permeability occurs by the downregulation of ERK1/2, the activation of Jnk, p38, Src, and apoptosis, resulting in the cleavage of tight junction proteins, and are attenuated by p38 inhibition. [ABSTRACT FROM AUTHOR]

Acute Respiratory Distress Syndrome (ARDS) is a severe lung condition with a high mortality rate for which there are no effective therapeutics. The failure of the alveolar–capillary barrier, composed of lung endothelial (EC) and alveolar epithelial (AEC) cells, is a critical factor leading to excessive inflammation and edema characteristic of acute lung injury (ALI) pathophysiology. Phosphodiesterases (PDE) are enzymes well-recognized for their roles in regulating endothelial permeability and inflammation. Although PDE inhibitors are used as therapeutics for inflammatory diseases like COPD (chronic obstructive pulmonary disease), their efficacy in treating ARDS has not yet been established. In this study, we investigated the effects of ensifentrine, an FDA-approved novel dual PDE 3/4 inhibitor, on lung endothelial and epithelial dysfunction caused by methicillin-resistant S. aureus (MRSA), a pathogen involved in bacterial ARDS. Human primary lung endothelial cells and alveolar epithelial cell lines (A549 and immortalized AEC) were treated with heat-killed MRSA, and their responses were assessed in the presence or absence of ensifentrine. Ensifentrine given either pre- or post-exposure attenuated MRSA-induced increased lung endothelial permeability. VE-cadherin junctions, which serve to stabilize the EC barrier, were disrupted by MRSA; however, ensifentrine effectively prevented this disruption. Pre-treatment with ensifentrine protected against MRSA-induced EC pro-inflammatory signaling by inhibiting the expression of VCAM-1, ICAM-1, and by reducing the IL-6 and IL-8 release. In AEC, MRSA caused the upregulation of ICAM-1, the activation of NF-kB, and the production of IL-8, all of which were inhibited by ensifentrine. These results indicate that the dual inhibition of phosphodiesterases 3 and 4 by ensifentrine is barrier protective and attenuates MRSA-induced inflammation in both lung endothelial and epithelial cells. The PDE3/4 inhibitor ensifentrine may represent a promising novel strategy for the treatment of MRSA-induced ARDS. [ABSTRACT FROM AUTHOR]

Simple Summary: STING agonists face challenges in breast cancer treatment due to their lower accumulation in tumors and rapid clearance from the body, resulting in a short duration of therapeutic effect. Novel phase-transitional liposomes loaded with STING agonists have been developed to overcome these limitations and are specifically designed for low-intensity focused ultrasound (LIFU)-assisted molecular imaging and precise treatment of breast cancer. With the assistance of LIFU, iRGD-modified liposomes (a targeting peptide) undergo a phase transition into microbubbles, leading to enhanced ultrasound molecular imaging of tumors and facilitating breast cancer immunotherapy by releasing STING agonists from the ultrasound-targeted liposomes. Background: Pharmacologically targeting the STING pathway offers a novel approach to cancer immunotherapy. However, small-molecule STING agonists face challenges such as poor tumor accumulation, rapid clearance, and short-lived effects within the tumor microenvironment, thus limiting their therapeutic potential. To address the challenges of poor specificity and inadequate targeting of STING in breast cancer treatment, herein, we report the design and development of a targeted liposomal delivery system modified with the tumor-targeting peptide iRGD (iRGD-STING-PFP@liposomes). With LIFU irradiation, the liposomal system exploits acoustic cavitation, where gas nuclei form and collapse within the hydrophobic region of the liposome lipid bilayer (transient pore formation), which leads to significantly enhanced drug release. Methods: Transmission electron microscopy (TEM) was used to investigate the physicochemical properties of the targeted liposomes. Encapsulation efficiency and in vitro release were assessed using the dialysis bag method, while the effects of iRGD on liposome targeting were evaluated through laser confocal microscopy. The CCK-8 assay was used to investigate the toxicity and cell growth effects of this system on 4T1 breast cancer cells and HUVEC vascular endothelial cells. A subcutaneous breast cancer tumor model was established to evaluate the tumor-killing effects and therapeutic mechanism of the newly developed liposomes. Results: The liposome carrier exhibited a regular morphology, with a particle size of 232.16 ± 19.82 nm, as indicated by dynamic light scattering (DLS), and demonstrated low toxicity to both HUVEC and 4T1 cells. With an encapsulation efficiency of 41.82 ± 5.67%, the carrier exhibited a slow release pattern in vitro after STING loading. Targeting results indicated that iRGD modification enhanced the system's ability to target 4T1 cells. The iRGD-STING-PFP@liposomes group demonstrated significant tumor growth inhibition in the subcutaneous breast cancer mouse model with effective activation of the immune system, resulting in the highest populations of matured dendritic cells (71.2 ± 5.4%), increased presentation of tumor-related antigens, promoted CD8+ T cell infiltration at the tumor site, and enhanced NK cell activity. Conclusions: The iRGD-STING-PFP@liposomes targeted drug delivery system effectively targets breast cancer cells, providing a new strategy for breast cancer immunotherapy. These findings indicate that iRGD-STING-PFP@liposomes could successfully deliver STING agonists to tumor tissue, trigger the innate immune response, and may serve as a potential platform for targeted immunotherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Radiotherapy remains a central pillar in the therapy of solid tumors, including lung cancer. However, the clinically applied radiation dose to a lung tumor is limited by the radiation-sensitivity of the surrounding normal tissue such as the lungs and heart. Ionizing irradiation causes reactive oxygen species (ROS)-induced chronic vascular inflammation, which can result in fatal irradiation-induced lung diseases such as pneumonitis and fibrosis. In this study, we demonstrate that cannabidiol (CBD), the non-psychogenic component of cannabis, mediates anti-inflammatory and anti-oxidative effects that protect the microvasculature of the lung against radiation-induced damage using in vitro and in vivo murine models. CBD therefore has the potential to improve the clinical outcome of radiotherapy by reducing normal tissue toxicity in the lung. Objective: Radiotherapy, which is commonly used for the local control of thoracic cancers, also induces chronic inflammatory responses in the microvasculature of surrounding normal tissues such as the lung and heart that contribute to fatal radiation-induced lung diseases (RILDs) such as pneumonitis and fibrosis. In this study, we investigated the potential of cannabidiol (CBD) to attenuate the irradiation damage to the vasculature. Methods: We investigated the ability of CBD to protect a murine endothelial cell (EC) line (H5V) and primary lung ECs isolated from C57BL/6 mice from irradiation-induced damage in vitro and lung ECs (luECs) in vivo, by measuring the induction of oxidative stress, DNA damage, apoptosis (in vitro), and induction of inflammatory and pro-angiogenic markers (in vivo). Results: We demonstrated that a non-lethal dose of CBD reduces the irradiation-induced oxidative stress and early apoptosis of lung ECs by upregulating the expression of the cytoprotective mediator heme-oxygenase-1 (HO-1). The radiation-induced increased expression of inflammatory (ICAM-2, MCAM) and pro-angiogenic (VE-cadherin, Endoglin) markers was significantly reduced by a continuous daily treatment of C57BL/6 mice with CBD (i.p. 20 mg/kg body weight), 2 weeks before and 2 weeks after a partial irradiation of the lung (less than 20% of the lung volume) with 16 Gy. Conclusions: CBD has the potential to improve the clinical outcome of radiotherapy by reducing toxic side effects on the microvasculature of the lung. [ABSTRACT FROM AUTHOR]

Type three secretion system (TTSS)-competent Pseudomonas aeruginosa expressing soluble promiscuous cyclase, exoenzyme Y (ExoY), generates cyclic nucleotides in pulmonary microvascular endothelial cells (PMVECs). Within cells, cyclic nucleotide signals are highly compartmentalized, but these second messengers are also released into the extracellular space. Although agonist stimulation of endogenous adenylyl cyclase (AC) or the presence of ExoY increases cyclic nucleotides, the proportion of the signal that is in the intracellular versus extracellular compartments is unresolved. Furthermore, it is unclear whether P. aeruginosa primary infection or treatment with sterile media supernatants derived from a primary infection alters beta-adrenergic agonist-induced elevations in cAMP in PMVECs. Herein, we determine that PMVECs release cAMP into the extracellular space constitutively, following beta-adrenergic stimulation of endogenous AC, and following infection with P. aeruginosa expressing ExoY. Surprisingly, in PMVECs, only a small proportion of cGMP is detected within the cell at baseline or following P. aeruginosa ExoY infection with a larger proportion of total cGMP being detected extracellularly. Thus, the ability of lung endothelium to generate cyclic nucleotides may be underestimated by examining intracellular cyclic nucleotides alone, since a large portion is delivered into the extracellular compartment. In addition, P. aeruginosa infection or treatment with sterile media supernatants from a primary infection suppresses the beta-adrenergic cAMP response, which is further attenuated by the expression of functional ExoY. These findings reveal an overabundance of extracellular cyclic nucleotides following infection with ExoY expressing TTSS-competent P. aeruginosa. NEW & NOTEWORTHY:P. aeruginosa exoenzyme Y (ExoY) infection increases cyclic nucleotides intracellularly, but an overabundance of cAMP and cGMP is also detected in the extracellular space and reveals a greater capacity of pulmonary endothelial cells to generate cAMP and cGMP. P. aeruginosa infection or treatment with sterile media supernatants derived from a primary infection suppresses the β-adrenergic-induced cAMP response in pulmonary endothelial cells, which is exacerbated by the expression of functional ExoY. [ABSTRACT FROM AUTHOR]

Objective: Porphyromonas gingivalis (P. gingivalis), one of the major periodontopathogens, is associated with the progression and exacerbation of atherosclerosis. In this study, we aimed to investigate whether the gastrin-releasing peptide receptor antagonist, RC-3095, could attenuate P. gingivalis LPS-induced inflammatory responses in endothelial cells and macrophages, as well as atherosclerosis in an ApoE−/− mouse model treated with P. gingivalis LPS. Methods: The effect of RC-3095 on P. gingivalis LPS-induced endothelial inflammation was examined using HUVECs and rat aortic endothelium. THP-1 cells were polarized into M1 macrophages by exposure to P. gingivalis LPS, with or without RC-3095. The effect of RC-3095 on atherosclerosis progression was assessed in high-fat-fed male ApoE−/− mice through injections of P. gingivalis LPS, RC-3095, or a combination of both. Results: RC-3095 significantly reduced P. gingivalis LPS-induced leukocyte adhesion to endothelial cells and aortic endothelium by suppressing NF-κB-dependent expressions of ICAM-1 and VCAM-1. In addition, RC-3095 inhibited the P. gingivalis LPS-induced polarization of M1 macrophages by blocking the MAPK and NF-κB signaling pathways. Moreover, RC-3095 decreased the area of atherosclerotic lesions in ApoE–/– mice, which was accelerated by P. gingivalis LPS injection, and lowered the expressions of ICAM-1 and VCAM-1 in the aortic tissue of mice with atherosclerosis. Conclusions: RC-3095 can alleviate P. gingivalis LPS-induced endothelial inflammation, macrophage polarization, and atherosclerosis progression, suggesting its potential as a therapeutic approach for periodontal pathogen-associated atherosclerosis. [ABSTRACT FROM AUTHOR]

T‐cell‐mediated therapeutic strategies are the most potent effectors of cancer immunotherapy. However, an essential barrier to this therapy in solid tumors is disrupting the anti‐cancer immune response, cancer‐immunity cycle, T‐cell priming, trafficking and T‐cell cytotoxic capacity. Thus, reinforcing the anti‐cancer immune response is needed to improve the effectiveness of T‐cell‐mediated therapy. Tumor‐associated protease ADAM10, endothelial cells (ECs) and cytotoxic CD8+ T cells engage in complex communication via adhesion, transmigration and chemotactic mechanisms to facilitate an anti‐cancer immune response. The precise impact of ADAM10 on the intricate mechanisms underlying these interactions remains unclear. This paper broadly explores how ADAM10, through different routes, influences the efficacy of T‐cell‐mediated therapy. ADAM10 cleaves CD8+ T‐cell‐targeting genes and impacts their expression and specificity. In addition, ADAM10 mediates the interactions of adhesion molecules with T cells and influences CD8+ T‐cell activity and trafficking. Thus, understanding the role of ADAM10 in these events may lead to innovative strategies for advancing T‐cell‐mediated therapies. [ABSTRACT FROM AUTHOR]

Cold atmospheric plasma (CAP) is an emerging technology that can generate various reactive oxygen and nitrogen species (RONS) at room temperature and shows promising applications for skin wound healing. The effects of plasma‐treated medium (PTM) promoting cell proliferation have been verified, but the biological mechanisms involved are not well known. This study aims to assess the proliferation effect and mechanism induced by PTM on human keratinocyte cells (HaCaT) and human umbilical vein endothelial cells (HUVEC) in vitro. The results showed that the concentrations of H2O2 and NO2− inside PTM increased in a time‐dependent manner as the atmospheric pressure plasma jet (APPJ) treatment time was prolonged. The biological outcomes were determined by cell counting kit, wound healing assay, flow cytometry, enzyme‐linked immunosorbent assay (ELISA), and western blot analysis. The cell viability and motility assays indicated that appropriate plasma conditions of short treatment time (15s‐, 30s‐ and 45s‐PTM) could promote cell proliferation, while long treatment time would inhibit cell proliferation (60s‐PTM). With an appropriate time of PTM treatment, the secretion of vascular endothelial growth factor‐α (VEGF‐α) and transforming growth factor alpha (TGF‐α) was promoted and the extracellular signal‐regulated kinase/serine‐threonine protein kinase pathways were activated, which induced HaCaT and HUVEC cell proliferation eventually. These behaviors of cells were mainly related to the enhancement of intracellular reactive oxygen species levels. These findings established a theoretical foundation for potential clinical applications of PTM in wound healing. [ABSTRACT FROM AUTHOR]

Chronic allograft dysfunction (CAD) poses a significant challenge in kidney transplantation, with renal vascular endothelial‐to‐mesenchymal transition (EndMT) playing a vital role. While renal vascular EndMT has been verified as an important contributing factor to renal allograft interstitial fibrosis/tubular atrophy in CAD patients, its underlying mechanisms remain obscure. Currently, Src activation is closely linked to organ fibrosis development. Single‐cell transcriptomic analysis in clinical patients revealed that Src is a potential pivotal mediator in CAD progression. Our findings revealed a significant upregulation of Src which closely associated with EndMT in CAD patients, allogeneic kidney transplanted rats and endothelial cells lines. In vivo, Src inhibition remarkably alleviate EndMT and renal allograft interstitial fibrosis in allogeneic kidney transplanted rats. It also had a similar antifibrotic effect in two endothelial cell lines. Mechanistically, the knockout of Src resulted in an augmented AMBRA1‐mediated mitophagy in endothelial cells. We demonstrate that Src knockdown upregulates AMBRA1 level and activates mitophagy by stabilizing Parkin's ubiquitination levels and mitochondrial translocation. Subsequent experiments demonstrated that the knockdown of the Parkin gene inhibited mitophagy in endothelial cells, leading to increased production of Interleukin‐6, thereby inducing EndMT. Consequently, our study underscores Src as a critical mediator of renal vascular EndMT and allograft interstitial fibrosis, exerting its impact through the regulation of AMBRA1/Parkin‐mediated mitophagy. [ABSTRACT FROM AUTHOR]

Background: Abnormal sphingolipid metabolism (SM) is closely linked to the incidence of cancers. However, the role of SM in pancreatic cancer (PC) remains unclear. This study aims to explore the significance of SM in the prognosis, immune microenvironment, and treatment of PC. Methods: Single-cell and bulk transcriptome data of PC were acquired via TCGA and GEO databases. SM-related genes (SMRGs) were obtained via MSigDB database. Consensus clustering was utilized to construct SM-related molecular subtypes. LASSO and Cox regression were utilized to build SM-related prognostic signature. ESTIMATE and CIBERSORT algorithms were employed to assess the tumour immune microenvironment. OncoPredict package was used to predict drug sensitivity. CCK-8, scratch, and transwell experiments were performed to analyze the function of ANKRD22 in PC cell line PANC-1 and BxPC-3. Results: A total of 153 SMRGs were acquired, of which 48 were linked to PC patients' prognosis. Two SM-related subtypes (SMRGcluster A and B) were identified in PC. SMRGcluster A had a poorer outcome and more active SM process compared to SMRGcluster B. Immune analysis revealed that SMRGcluster B had higher immune and stromal scores and CD8 + T cell abundance, while SMRGcluster A had a higher tumour purity score and M0 macrophages and activated dendritic cell abundance. PC with SMRGcluster B was more susceptible to gemcitabine, paclitaxel, and oxaliplatin. Then SM-related prognostic model (including ANLN, ANKRD22, and DKK1) was built, which had a very good predictive performance. Single-cell analysis revealed that in PC microenvironment, macrophages, epithelial cells, and endothelial cells had relatively higher SM activity. ANKRD22, DKK1, and ANLN have relatively higher expression levels in epithelial cells. Cell subpopulations with high expression of ANKRD22, DKK1, and ANLN had more active SM activity. In vitro experiments showed that ANKRD22 knockdown can inhibit the proliferation, migration, and invasion of PC cells. Conclusion: This study revealed the important significance of SM in PC and identified SM-associated molecular subtypes and prognostic model, which provided novel perspectives on the stratification, prognostic prediction, and precision treatment of PC patients. [ABSTRACT FROM AUTHOR]

The prevalence of coronary heart disease (CHD) has increased significantly with the aging population worldwide. It is unclear whether ferroptosis occurs during CHD. Hence, we aimed to investigate the potential mechanisms associated with ferroptosis in CHD. Bioinformatics was used to characterize differentially expressed genes (DEGs) in CHD-related datasets (GSE21610 and GSE66360). There were 76 and 689 DEGs in the GSE21610 and GSE66360, respectively, and they predominantly associated with immune and inflammatory responses. DDX3Y, EIF1AY, KDM5D, RPS4Y1, SGK1, USP9Y, and NSG1 were intersecting DEGs of GSE21610 and GSE66360. Their expression pattern in circulating endothelial cells (ECs) derived from healthy individuals and CHD patients are consistent with the results of bioinformatics analysis, especially SGK1. In vitro , SGK1 knockdown alleviated the Erastin-induced downregulation of SLC7A11, GPX4, GSH, and GSSG, as well as the upregulation of lipid peroxidation, Fe accumulation, and mitochondrial damage in mouse aortic ECs (MAECs). Notably, SGK1 may interact with NEDD4L according to the String database. Moreover, SGK1 promoted NEDD4L and p-P65 expression in MAECs. Interestingly, the effect of SGK1 knockdown on ferroptosis in MAECs was rescued by overexpression of NEDD4L or PMA (NF-κB pathway activator). In vivo , SGK1 knockdown facilitated the recovery of body weight, blood lipids, and aortic tissue structure in CHD animal models. Furthermore, SGK1 knockdown alleviated Fe accumulation in the aorta and inactivated the NEDD4L-NF-κB pathway. In conclusion, SGK1 contributes to EC ferroptosis by regulating the NEDD4L-NF-κB pathway. SGK1 could be recognized as a therapeutic target related to ferroptosis in CHD. [Display omitted] • SGK1 is aberrantly high-expressed in CHD-derived circulating endothelial cells. • SGK1 contributes to endothelial cell ferroptosis in coronary heart disease. • SGK1 interacts with NEDD4L, and facilitates the expression of NEDD4L. • NEDD4L and NF-κB pathway are downstream of SGK1-mediated ferroptosis. [ABSTRACT FROM AUTHOR]

5-Fluorouracil (5-FU) is a first-line treatment for colorectal cancer, but side effects such as severe diarrhea are common in clinical use and have been linked to its induction of normal cell senescence. Chloramphenicol (CAP) is an antibiotic commonly used to treat typhoid or anaerobic infections, but its senescence-related aspects have not been thoroughly investigated. Here, we used 5-FU to induce senescence in human umbilical vein endothelial cells (HUVECs) and investigated the relationship between CAP and cellular senescence at the cellular level. In a model of cellular senescence induced by 5-FU treatment, we discovered that CAP treatment reversed the rise in the percentage of senescence-associated galactosidase (SA-β-gal)-positive cells and decreased the expression of senescence-associated proteins (p16), senescence-associated genes (p21), and senescence-associated secretory phenotypes (SASPs: IL-6, TNF-α). In addition, CAP subsequently restored the autophagic process inhibited by 5-FU and upregulated the levels of autophagy-related proteins. Mechanistically, we found that CAP restored autophagic flux by inhibiting the mTOR pathway, which in turn alleviated FU-induced cellular senescence. Our findings suggest that CAP may help prevent cellular senescence and restore autophagy, opening up new possibilities and approaches for the clinical management of colorectal cancer. [ABSTRACT FROM AUTHOR]

Type 2 diabetes mellitus (T2DM) is associated with a heightened risk of cardiovascular and renal complications. While glycemic control remains essential, newer therapeutic options, such as SGLT2 inhibitors, offer additional benefits beyond glucose reduction. This review delves into the mechanisms underlying the cardio-renal protective effects of SGLT2 inhibitors. By inducing relative hypoglycemia, these agents promote ketogenesis, optimize myocardial energy metabolism, and reduce lipotoxicity. Additionally, SGLT2 inhibitors exert renoprotective actions by enhancing renal perfusion, attenuating inflammation, and improving iron metabolism. These pleiotropic effects, including modulation of blood pressure, reduction of uric acid, and improved endothelial function, collectively contribute to the cardiovascular and renal benefits observed with SGLT2 inhibitor therapy. This review will provide clinicians with essential knowledge, understanding, and a clear recollection of this pharmacological group's mechanism of action. [ABSTRACT FROM AUTHOR]

Suppression of Tumorigenicity 2 (ST2) is a member of the interleukin-1 receptor/ Toll-like receptor superfamily, and its specific ligand is Interleukin-33 (IL-33). IL-33/ ST2 signaling has been implicated in numerous inflammatory and allergic diseases, as well as in promoting malignant behavior of tumor cells and angiogenesis. However, the precise role of ST2 in gastric cancer angiogenesis remains incompletely elucidated. We observed a significant correlation between high expression of ST2 in gastric cancer tissues and poor prognosis, along with various clinicopathological features. In vitro experiments demonstrated that the IL-33/ ST2 axis activates the PI3K/AKT/NF-κB signaling pathway through TRAF6, thereby promoting VEGFA-mediated tumor angiogenesis; meanwhile sST2 acts as a decoy receptor to regulate the IL-33/ST2L axis. Consistent findings were also observed in subcutaneous xenograft tumor models in nude mice. Furthermore, we investigated the molecular mechanism by which IL-33 promotes ST2L expression in GC cells via upregulation of transcription factors YY1 and GATA2 through intracellular signaling pathways. [ABSTRACT FROM AUTHOR]

Excessive extracellular matrix deposition and increased intrahepatic angiogenesis are prominent features of cirrhosis. β-arrestin2 is thought to be involved in the pathological processes of various fibrotic diseases. This study aimed to investigate the role and possible mechanism of β-arrestin2 in the angiogenesis of cirrhosis. Firstly, β-arrestin2 expression in liver tissues of cirrhotic patients was detected, and the correlation between β-arrestin2 and α-SMA, CD-31, PDGF, and VEGF indexes was analyzed. Then, after liver cirrhosis induced by CCL 4 in Arrb2-KO mice (β-arrestin2 coding gene), liver histopathological changes were observed, and the expressions of α-SMA, CD-31, PDGF, VEGF, and VEGFR2 were detected. Finally, VEGF-A was used to treat human liver sinusoidal endothelial cells (LSECs) to simulate pathological conditions. After transfection with si-ARRB2, the cell activity, MDA and GSH-PX activities, cell invasion, angiogenesis, and the expressions of α-SMA, CD-31, and VEGF/VEGFR2 pathway were detected. Results showed that β-arrestin2 expression in the liver increased significantly during cirrhosis and was positively correlated with angiogenesis. In vivo , Arrb2-KO significantly inhibited fibrosis and angiogenesis in cirrhotic mice, and decreased the expressions of α-SMA, CD31, PDGF, VEGF, and VEGFR2. Studies using LSECs in vitro showed that after intervention of ARRB2, the activity of LSECs and the number of invasions and tubule formations were significantly reduced. Similarly, after transfection with si-ARRB2, the expressions of α-SMA, CD31, PDGF, VEGF, and VEGFR2 in LSECs were significantly decreased. Collectively, β-arrestin2 aggravated cirrhosis by promoting the angiogenesis of LSECs. Blocking β-arrestin2 may be an important target against angiogenesis and fibrosis in cirrhosis. [Display omitted] • β-arrestin2 expression was increased in cirrhosis and correlated with angiogenesis. • Knockout Arrb2 inhibited the progression of liver cirrhosis, reduce angiogenesis. • ARRB2 intervention inhibited the proliferation, invasion and angiogenesis of LSECs. • β-arrestin2 (Arrb2) promoted LSECs angiogenesis through the VEGF/VEGFR2 pathway. [ABSTRACT FROM AUTHOR]

Purpose: To explore the expression of matrix metalloproteinase-3 (MMP-3) in the aqueous humor of patients with Posner-Schlossman syndrome (PSS), and the association between MMP-3 and PSS. Methods: Peripheral blood and aqueous humor were routinely collected from 29 patients with PSS (PSS group) and 30 patients with age-related-cataract (ARC) (control group). The content of MMP-3 in serum and aqueous humor was measured by immunoturbidimetry. The correlation between MMP-3 and ophthalmic examination results were verified by Spearman's correlation analysis. Results: The MMP-3 level in the aqueous humor of the PSS group was (25.86 ± 13.4)ng/ml, significantly higher than that in the control group (3.9 ± 2.7)ng/ml(p < 0.001), while there was no significant difference in serum MMP-3 level between the two groups (p = 0.125). The endothelial cell density (ECD) in the aqueous humor of the PSS group was (2078 ± 440) cell/mm2, intraocular pressure (IOP) in the aqueous humor of the PSS group was (33 ± 12) mmHg. The correlation analysis of aqueous humor MMP-3 and various ophthalmic examination results showed that aqueous humor MMP-3 had a moderate correlation with IOP and the difference in ECD between the affected eye and the fellow eye. Conclusions: MMP-3 level is elevated in the aqueous humor of PSS patients, and it may play an important role in the pathogenesis of PSS. [ABSTRACT FROM AUTHOR]

Purpose: To uncover the possible effects of zerumbone on the viability, motility, and angiogenesis of human retinal microvascular endothelial cells and to clarify the mechanism. Methods: 5-Ethynyl-2′-deoxyuridine assays were conducted to confirm the effects of zerumbone on the viability of human retinal microvascular endothelial cells. Wound healing, tube formation, and immunoblot assays were conducted to confirm the role of zerumbone in human retinal microvascular endothelial cell motility and angiogenesis, and regulation on vascular endothelial growth factor expression. ELISA was performed to confirm its effects on vascular endothelial growth factor secretion. Colivelin was used to activate the STAT3. Results: We revealed that zerumbone suppressed the viability of human retinal microvascular endothelial cells. Zerumbone restrained the motility and angiogenesis of human retinal microvascular endothelial cells via targeting STAT3 and regulating the expression and secretion of vascular endothelial growth factor in vitro. Zerumbone treatment suppressed the angiogenesis, whereas Colivelin treatment reversed the suppression of angiogenesis caused by zerumbone. Conclusion: Zerumbone restrained the viability, motility and angiogenesis of human retinal microvascular endothelial cells by inhibiting vascular endothelial growth factor expression. [ABSTRACT FROM AUTHOR]

Introduction: Our aim was to evaluate the visual and refractive outcomes of iris-fixated phakic toric intraocular lenses (IOLs) for visual rehabilitation in eyes with stable corneal ectasia. Methods: We conducted a study looking at the clinical outcomes of iris-fixated toric IOLs (Artisan) in 33 eyes of 27 patients diagnosed with mild-to-moderate corneal ectasia at a single center (Queen Victoria Hospital, East Grinstead, UK). The main outcome measures were functional improvement [accuracy of post-operative spherical equivalent (SE), astigmatic correction, topographic parameters, uncorrected and corrected distance visual acuity (UCVA, CDVA)] and safety of the procedure: endothelial cell count and intra- and post-operative complications. Results: Eighteen males and nine females of mean age 38.85 were included in the study with a mean follow-up of 18 months. All patients had ectasia due to keratoconus except one with post-refractive laser ectasia. Twelve patients had crosslinking, eight had intracorneal rings, and eight had previous keratoplasties. Mean pre-operative logMAR UCVA was 0.75 ± 0.35 improving to 0.02 ± 0.17 (p = 0.000). Mean pre-operative logMAR CDVA was 0.16 ± 0.17 improving to 0.02 ± 0.17 (p = 0.000). Mean pre-operative (SE) was − 3.5 ± 3.9 improving to − 2.75 ± 1.39 (p = 0.000) with up to 36–42 months of follow-up. The mean value of endothelial cell density in the overall sample was 2252.54 ± 473.24 cells/mm2 pre-operatively and 2126.75 ± 365.21 cells/mm2 at 24–36 months of follow-up visit. Two patients have intra-operative hyphemia secondary to iris prolapse. Conclusions: Implantation of iris-fixated phakic toric IOLs has shown high efficacy and safety in patients with mild-to-moderate astigmatism in corneal ectasia. [ABSTRACT FROM AUTHOR]

Astragali Radix (AR), a common traditional Chinese medicinal herb, exhibits protective effects on diabetic nephropathy (DN) in extensive researches. Aticles focusing on AR in PubMed were collected and reviewed in order to summarize the latest pharmacological effects on DN. The action mechanisms for protectiving effects of AR were associated with regulation of anti-fibrosis, anti-inflammation, anti-oxidative stress, anti-podocyte apoptosis, restoration of mitochondrial function, restoration of endothelial function in diabetes nephropathy experimental models. Consequently, AR hold promise as potential novel therapeutics for the treatment of DN. [ABSTRACT FROM AUTHOR]

Introduction/objectives: JAK/STAT signaling inhibition exerts therapeutic effects on angiogenesis in rheumatoid arthritis (RA). However, whether the inhibitory effect differs among JAK inhibitors because of differing selectivity is unknown. Therefore, we compared the inhibitory effects of tofacitinib, baricitinib, peficitinib, upadacitinib, and filgotinib on angiogenesis. Method: RA-derived fibroblast-like synoviocytes (RA-FLS) were seeded on type I collagen gel, and human umbilical vein endothelial cells (HUVECs) were directly added. The control and aforementioned JAK inhibitors were added to the medium, followed by stimulation with interleukin (IL)-6 and soluble IL-6 receptor (sIL-6R). Each JAK inhibitor's concentration was determined based on estimated blood concentrations. The vascular endothelial growth factor (VEGF) concentration was evaluated with an enzyme-linked immunosorbent assay using the medium from the first exchange. A migration assay was performed, and HUVEC migration was evaluated using CD31 fluorescence immunostaining. Results: Hematoxylin–eosin staining showed that compared with the non-JAKi treatment group, the JAKi treatment group markedly degenerated in the sub-lining and deep lining, with decreased lymphocyte infiltration and neovascularization [Rooney's score subscale, non-JAKi vs JAKi (median, 6.5 vs 2.5, p = 0.005)]. In vitro, IL-6 and sIL-6R administration increased VEGF production from RA-FLS and promoted neovascularization in HUVECs, and JAK-inhibitor administration, which decreased VEGF production from RA-FLS and suppressed HUVEC migration, inhibited neovascularization in RA-FLS and HUVEC co-cultures. Conclusions: The JAK inhibitors suppressed IL-6-induced angiogenesis via decreased VEGF production and HUVEC migration in RA-FLS and HUVEC co-cultures. No significant differences were observed among the JAK inhibitors, whose anti-angiogenic effect may be an important mechanism for RA treatment. Key Points • JAK inhibitors inhibit angiogenesis in RA by reducing VEGF production from RA-derived fibroblast-like synoviocytes. • Our study provides new insights into RA treatment by elucidating the anti-angiogenic effect of JAK inhibitors. [ABSTRACT FROM AUTHOR]

The underlying mechanisms and clinical impact of portal microthrombosis in severe COVID-19 are unknown. Intrapulmonary vascular dilation (IPVD)-related hypoxia has been described in severe liver diseases. We hypothesised that portal microthrombosis is associated with IPVD and fatal respiratory failure in COVID-19. Ninety-three patients who died from COVID-19 were analysed for portal microvascular damage (histology), IPVD (histology and chest-computed tomography, CT), and hypoxemia (arterial blood gas). Seventeen patients who died from COVID-19-unrelated pneumonia served as controls. Vascular lesions and microthrombi were phenotyped for endothelial (vWF) and pericyte (αSMA/PDGFR-β) markers, tissue factor (TF), viral spike protein and nucleoprotein (SP, NP), fibrinogen, and platelets (CD41a). Viral particles in vascular cells were assessed by transmission electron microscopy. Cultured pericytes were infected with SARS-CoV-2 to measure TF expression and tubulisation of human pulmonary microvascular endothelial cells was assessed upon vWF treatment. IPVD was present in 16/66 patients with COVID-19, with available liver and lung histology, and was associated with younger age (62 vs. 78 years-old), longer illness (25 vs. 14 days), worsening hypoxemia (PaO 2 /FiO 2 from 209 to 89), and an increased requirement for ventilatory support (63% vs. 22%) compared to COVID-19/Non-IPVD. IPVD, absent in controls, was confirmed by chest CT. COVID-19/IPVD liver histology showed portal microthrombosis in >82.5% of portal areas, with a thicker wall of αSMA/PDGFR-β+/SP+/NP+ pericytes compared with COVID-19/Non-IPVD. Thrombosed portal venules correlated with αSMA+ area, whereas infected SP+/NP+ pericytes expressed TF. SARS-CoV-2 viral particles were observed in portal pericytes. In vitro SARS-CoV-2 infection of pericytes upregulated TF and induced endothelial cells to overexpress vWF, which expanded human pulmonary microvascular endothelial cell tubules. SARS-CoV-2 infection of liver pericytes elicits a local procoagulant response associated with extensive portal microthrombosis, IPVD and worsening respiratory failure in fatal COVID-19. Vascular involvement of the liver represents a serious complication of COVID-19 infection that must be considered in the work-up of patients with long-lasting and progressively worsening respiratory failure, as it may associate with the development of intrapulmonary vascular dilations. This clinical picture is associated with a procoagulant phenotype of portal venule pericytes, which is induced by SARS-CoV-2 infection of pericytes. Both observations provide a model that may apply, at least in part, to other vascular disorders of the liver, featuring obliterative portal venopathy, similarly characterised at the clinical level by development of hypoxemia and at the histological level by phlebosclerosis and reduced calibre of the portal vein branches in the absence of cirrhosis. Moreover, our findings shed light on an overlooked player in the pathophysiology of thrombosis, i.e. pericytes, which may present a novel therapeutic target. [Display omitted] • Portal vein microthrombosis is associated with IPVD in fatal COVID-19-related hypoxia. • In thrombosed portal venules, pericytes are preponderantly infected by SARS-CoV-2. • Pericytes embedding the thrombosed portal vein radicles overexpress tissue factor. • SARS-CoV-2 induces infected pericytes to overexpress tissue factor. • Infected pericytes kindle endothelial cells to overexpress von Willebrand factor. [ABSTRACT FROM AUTHOR]

Under normal circumstances, high-density lipoprotein (HDL) is considered to have cardiovascular protective effects, but the impact of oxidized HDL (ox-HDL) on vascular endothelial function remains poorly understood. Mitochondrial function is closely related to endothelial function, and hydrogen sulfide (H₂S) is a gas with endothelial protective properties. The novel hydrogen sulfide donor AP39 can target mitochondria to release H₂S, but the combined effects of ox-HDL and AP39 on vascular endothelium are not well studied. We established a cell model of ox-HDL-induced endothelial cell damage and mitochondrial dysfunction using human umbilical vein endothelial cells (HUVECs) and conducted AP39 pretreatment. The experiments confirmed the functional damage and mitochondrial dysfunction in HUVECs caused by ox-HDL. Additionally, to further explore the role of SIRT1 in AS, we analyzed SIRT1 expression in AS carotid artery tissue. This included the analysis of differentially expressed genes from AS-related datasets, presented through volcano plots and heatmaps, with enrichment analysis of downregulated genes in KEGG pathways and GO functions. Furthermore, we evaluated the differences in SIRT1 expression in coronary arteries with varying degrees of stenosis and in early and late-stage AS carotid artery tissues, and analyzed data from SIRT1 knockout mouse models. The experimental results indicate that AP39 effectively alleviated ox-HDL-induced endothelial cell damage and mitochondrial dysfunction by upregulating SIRT1 expression. MTT and CCK-8 assays showed that ox-HDL treatment led to decreased cell viability and proliferation in HUVECs, reduced eNOS expression, and significantly increased levels of ICAM-1, IL-6, and TNF-α, along with enhanced monocyte adhesion. These findings reveal the damaging effects of ox-HDL on HUVECs. Transcriptomic data indicated that while SIRT1 expression did not significantly differ in coronary arteries with varying degrees of stenosis, it was notably downregulated in AS carotid artery tissues, especially in late-stage AS tissues. KEGG pathway enrichment analysis revealed that SIRT1 downregulated genes were associated with processes such as vascular smooth muscle contraction, while GO analysis showed that these downregulated genes were involved in muscle system processes and muscle contraction functions, further confirming SIRT1's critical role in AS pathology. In transcriptomic data from the SIRT1 knockout mouse model, elevated levels of inflammation-related proteins IL-6 and TNF-α were observed after SIRT1 knockout, along with decreased expression of the chaperone protein PGC-1α. The expression of mitochondrial-related functional proteins Nrf2 and PGC-1α was positively correlated with SIRT1 expression, while inflammation-related proteins ICAM-1, IL-6, IL-20, and TNF-α were negatively correlated with SIRT1 expression. We further discovered that ox-HDL triggered mitochondrial dysfunction, as evidenced by reduced expression of Mfn2, Nrf2, PGC1-α, UCP-1, and SIRT1, corroborating the results from the previous database analysis. Additionally, mitochondrial dysfunction was characterized by decreased mitochondrial membrane potential (MMP), increased mitochondrial ROS levels, and reduced ATP content, further impacting cellular energy metabolism and respiratory function. Subsequent experimental results showed that the addition of AP39 mitigated these adverse effects, as evidenced by decreased levels of ICAM-1, IL-6, and TNF-α, increased eNOS expression, reduced monocyte adhesion, increased mitochondrial H₂S content, and upregulated expression of SIRT1 protein associated with mitochondrial function, reduced ROS levels, and increased ATP content. Furthermore, validation experiments using the SIRT1 inhibitor EX527 confirmed that AP39 alleviated ox-HDL-induced endothelial cell damage and mitochondrial dysfunction by upregulating SIRT1 expression. Ox-HDL can induce damage and mitochondrial dysfunction in HUVECs, while AP39 inhibits ox-HDL-induced endothelial cell damage and mitochondrial dysfunction by upregulating SIRT1. • Mechanism Insight: Elucidates ox-HDL's harmful effects on endothelial cells, focusing on SIRT1 downregulation and mitochondrial dysfunction. • Mitochondrial Targeting : AP39, a mitochondria-targeted hydrogen sulfide donor, mitigates ox-HDL-induced damage by upregulating SIRT1. • Cellular and Molecular Impact: AP39 improves cell survival, reduces pro-inflammatory markers, and decreases monocyte adhesion in endothelial cells. • Mitochondrial Function Preservation: AP39 enhances mitochondrial membrane potential, reduces ROS, and increases ATP content, maintaining mitochondrial function. • Therapeutic Potential : Suggests AP39 as a therapy for atherosclerosis by targeting mitochondrial dysfunction and endothelial injury caused by ox-HDL. [ABSTRACT FROM AUTHOR]