Blood Vascular Endothelial Cells Research Articles

A new model of portal vein thrombosis in rats with cirrhosis induced by partial portal vein ligation plus carbon tetrachloride and intervened with rivaroxaban

Background and aimsPortal vein thrombosis (PVT) is a common complication of liver cirrhosis that can aggravate portal hypertension. However, there are features of both PVT and cirrhosis that are not recapitulated in most current animal models. In this study, we aimed to establish a stable animal model of PVT and cirrhosis, intervene with anticoagulant, and explore the related mechanism.MethodsFirst, 49 male SD rats received partial portal vein ligation (PPVL), and 44 survival rats were divided into 6 groups: PPVL control group; 4-week, 6 -week, 8-week, and 10-week model group; and the rivaroxaban (RIVA)-treated group. The rats were intoxicated with or without carbon tetrachloride (CCl4) for 4–10 weeks. Seven normal rats were used as the normal controls. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and parameters for blood coagulation were all assayed with kits. Liver inflammation, collagen deposition and hydroxyproline (Hyp) levels were also measured. The extrahepatic macro-PVT was observed via portal vein HE staining, etc. The intrahepatic microthrombi was stained via fibrin immunohistochemistry. The portal blood flow velocity (PBFV) and diameter were detected via color Doppler ultrasound. Vascular endothelial injury was evaluated by von Willebrand Factor (vWF) immunofluorescence. Fibrinolytic activity was estimated by western blot analysis of fibrin and plasminogen activator inhibitor-1 (PAI-1).ResultsAfter PPVL surgery and 10 weeks of CCl4 intoxication, a rat model that exhibited characteristics of both cirrhosis and extra and intrahepatic thrombi was established. In cirrhotic rats with PVT, the PBFV decreased, both factors of pro- and anti-coagulation decreased, but with relative hypercoagulable state, vascular endothelial injured, and fibrinolytic activity decreased. RIVA-treated rats had improved coagulation function, increased PBFV and attenuated thrombi. This effect was related to the improvements in endothelial injury and fibrinolytic activity.ConclusionsA new rat model of PVT with cirrhosis was established through partial portal vein ligation plus CCl4 intoxication, with the characteristics of macrothrombi at portal veins and microthrombi in hepatic sinusoids, as well as liver cirrhosis. Rivaroxaban could attenuate PVT in cirrhosis in the model rats. The underlying mechanisms of PVT formation in the rat model and pharmacological action of rivaroxaban are related to the regulation of portal blood flow, coagulant factors, and vascular endothelial cell function.

Development of a Mouse Experimental System for the In Vivo Characterization of Bioengineered Adipose-Derived Stromal Cells.

Human adipose-derived stromal cells (ADSCs) are an important resource for cell-based therapies. However, the dynamics of ADSCs after transplantation and their mechanisms of action in recipients remain unclear. Herein, we generated genetically engineered mouse ADSCs to clarify their biodistribution and post-transplantation status and to analyze their role in recipient mesenchymal tissue modeling. Immortalized ADSCs (iADSCs) retained ADSC characteristics such as stromal marker gene expression and differentiation potential. iADSCs expressing a fluorescent reporter gene were seeded into biocompatible nonwoven fabric sheets and transplanted into the dorsal subcutaneous region of neonatal mice. Transplanted donor ADSCs were distributed as CD90-positive stromal cells on the sheets and survived 1 month after transplantation. Although accumulation of T lymphocytes or macrophages inside the sheet was not observed with or without donor cells, earlier migration and accumulation of recipient blood vascular endothelial cells (ECs) inside the sheet was observed in the presence of donor cells. Thus, our mouse model can help in studying the interplay between donor ADSCs and recipient cells over a 1-month period. This system may be of value for assessing and screening bioengineered ADSCs in vivo for optimal cell-based therapies.

Abstract 2569: VEGFA gene expression is associated with cell proliferation, less immune cell infiltration, and worse survival, but better response to chemotherapy and immunotherapy

Abstract Introduction: Vascular endothelial growth factor-A (VEGFA) is a well-known factor that induces angiogenesis, one of the hallmarks of cancer, which generates new blood vessels in the tumor microenvironment (TME) and provides conduit for cancer to metastasize. Interestingly, an anti-VEGFA drug (Avastin) failed to show benefit in clinical trials for breast cancer (BC). In this study we investigated the clinical relevance of VEGFA gene expression in BC. Methods: A total of 7336 BC patients from eight independent cohorts, TCGA (n= 1073), METABRIC (n= 1903), SCAN-B (GSE96058, n= 3069), GSE20194 (n=278), GSE34138 (n=178), GSE163882 (n=222), GSE25066 (n=508), and ISPY2 (GSE173839, n= 105) were analyzed. These cohorts were divided into high and low VEGFA gene expression groups using the median. Results: High VEGFA expression in BC was associated with worse overall survival in SCAN-B cohort which was validated in METABRIC cohort with overall, disease-specific, and disease-free survival (all p<0.02). VEGFA expression was higher in Triple Negative BC (TNBC) but was lower in BC with lymph node metastasis. High VEGFA BC was associated with significantly high intratumoral heterogeneity, homologous recombination defect, silent and non-silent mutations, and SNV neoantigens in TCGA, and was also associated with higher cell proliferation, evidenced by higher Nottingham histological grade, higher Ki67 gene expression, and enrichment of all the Hallmark cell proliferation-related gene sets: Mitotic spindle, G2M Checkpoint, E2F Targets, MYC Targets v1 and v2, and mTorC1 signaling, consistently, in SCAN-B, METABRIC, and TCGA cohorts. Reflecting its enhanced growth, high VEGFA expression was associated with less infiltration of fibroblasts and adipocytes (all p<0.05). Surprisingly, VEGFA expression did not enrich angiogenesis gene set in any of the cohorts, nor was related with infiltrations of blood or lymphatic vascular endothelial cells, besides pericytes. But high VEGFA BC was associated with significantly less infiltrations of anti-cancer immune cells; CD8, CD4, and dendritic cells were all significantly less, and T helper type 1 cells and regulatory T cells were significantly higher consistently in SCAN-B, METABRIC, and TCGA cohorts. VEGFA expression was significantly higher in BC that achieved pathological complete response after Anthracycline and Taxane based neoadjuvant therapy in both ER+/HER2- and TNBC subtypes in the GSE25066 cohort, and after immunotherapy in ER+/HER2- subtype, but not TNBC, in the ISPY2 clinical trial cohort. This was not validated in GSE20194, GSE34138, GSE163882 cohorts. Conclusion: Our research indicates that high VEGFA BC is associated with high cell proliferation, less immune cell infiltration, and worse survival, but better response to Anthracycline and Taxane based chemotherapy, and immunotherapy. Citation Format: Pia Sharma, Kohei Chida, Kenichi Hakamada, Kazuaki Takabe. VEGFA gene expression is associated with cell proliferation, less immune cell infiltration, and worse survival, but better response to chemotherapy and immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2569.

Characterization of Vascular Niche in Systemic Sclerosis by Spatial Proteomics.

Systemic sclerosis (SSc) is a connective tissue disease that can serve as a model to study vascular changes in response to inflammation, autoimmunity, and fibrotic remodeling. Although microvascular changes are the earliest histopathologic manifestation of SSc, the vascular pathophysiology remains poorly understood. We applied spatial proteomic approaches to deconvolute the heterogeneity of vascular cells at the single-cell level in situ and characterize cellular alterations of the vascular niches of patients with SSc. Skin biopsies of patients with SSc and control individuals were analyzed by imaging mass cytometry, yielding a total of 90 755 cells including 2987 endothelial cells and 4096 immune cells. We identified 7 different subpopulations of blood vascular endothelial cells (VECs), 2 subpopulations of lymphatic endothelial cells, and 3 subpopulations of pericytes. A novel population of CD34+;αSMA+ (α-smooth muscle actin);CD31+ VECs was more common in SSc, whereas endothelial precursor cells were decreased. Co-detection by indexing and tyramide signal amplification confirmed these findings. The microenvironment of CD34+;αSMA+;CD31+ VECs was enriched for immune cells and myofibroblasts, and CD34+;αSMA+;CD31+ VECs expressed markers of endothelial-to-mesenchymal transition. The density of CD34+;αSMA+;CD31+ VECs was associated with clinical progression of fibrosis in SSc. Using spatial proteomics, we unraveled the heterogeneity of vascular cells in control individuals and patients with SSc. We identified CD34+;αSMA+;CD31+ VECs as a novel endothelial cell population that is increased in patients with SSc, expresses markers for endothelial-to-mesenchymal transition, and is located in close proximity to immune cells and myofibroblasts. CD34+;αSMA+;CD31+ VEC counts were associated with clinical outcomes of progressive fibrotic remodeling, thus providing a novel cellular correlate for the crosstalk of vasculopathy and fibrosis.

Analysis of extracellular vesicle microRNA profiles reveals distinct blood and lymphatic endothelial cell origins

AbstractExtracellular vesicles (EVs) are crucial mediators of cell‐to‐cell communication in physiological and pathological conditions. Specifically, EVs released from the vasculature into blood were found to be quantitatively and qualitatively different in diseases compared to healthy states. However, our understanding of EVs derived from the lymphatic system is still scarce. In this study, we compared the mRNA and microRNA (miRNA) expression in blood vascular (BEC) and lymphatic (LEC) endothelial cells. After characterization of the EVs by fluorescence‐triggered flow cytometry, nanoparticle tracking analysis and cryo‐transmission electron microscopy (cryo‐TEM) we utilized small RNA‐sequencing to characterize miRNA signatures in the EVs and identify cell‐type specific miRNAs in BEC and LEC. We found miRNAs specifically enriched in BEC and LEC on the cellular as well as the extracellular vesicle level. Our data provide a solid basis for further functional in vitro and in vivo studies addressing the role of EVs in the blood and lymphatic vasculature.

Lymphatic Endothelial-to-Myofibroblast Transition: A Potential New Mechanism Underlying Skin Fibrosis in Systemic Sclerosis.

At present, only a few reports have addressed the possible contribution of the lymphatic vascular system to the pathogenesis of systemic sclerosis (SSc). Based on the evidence that blood vascular endothelial cells can undertake the endothelial-to-myofibroblast transition (EndMT) contributing to SSc-related skin fibrosis, we herein investigated whether the lymphatic endothelium might represent an additional source of profibrotic myofibroblasts through a lymphatic EndMT (Ly-EndMT) process. Skin sections from patients with SSc and healthy donors were immunostained for the lymphatic endothelial cell-specific marker lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) in combination with α-smooth muscle actin (α-SMA) as the main marker of myofibroblasts. Commercial human adult dermal lymphatic microvascular endothelial cells (HdLy-MVECs) were challenged with recombinant human transforming growth factor-β1 (TGFβ1) or serum from SSc patients and healthy donors. The expression of lymphatic endothelial cell/myofibroblast markers was measured by quantitative real-time PCR, Western blotting and immunofluorescence. Collagen gel contraction assay was performed to assess myofibroblast-like cell contractile ability. Lymphatic endothelial cells in intermediate stages of the Ly-EndMT process (i.e., coexpressing LYVE-1 and α-SMA) were found exclusively in the fibrotic skin of SSc patients. The culturing of HdLy-MVECs with SSc serum or profibrotic TGFβ1 led to the acquisition of a myofibroblast-like morphofunctional phenotype, as well as the downregulation of lymphatic endothelial cell-specific markers and the parallel upregulation of myofibroblast markers. In SSc, the Ly-EndMT might represent a previously overlooked pathogenetic process bridging peripheral microlymphatic dysfunction and skin fibrosis development.

Impact of Hemostasis on the Lymphatic System in Development and Disease.

Lymphatic vessels form a systemic network that maintains interstitial fluid homeostasis and regulates immune responses and is strictly separated from the circulatory system. During embryonic development, lymphatic endothelial cells originate from blood vascular endothelial cells in the cardinal veins and form lymph sacs. Platelets are critical for separating lymph sacs from the cardinal veins through interactions between CLEC-2 (C-type lectin-like receptor-2) and PDPN (podoplanin) in lymphatic endothelial cells. Therefore, deficiencies of these genes cause blood-filled lymphatic vessels, leading to abnormal lymphatic vessel maturation. The junction between the thoracic duct and the subclavian vein has valves and forms physiological thrombi dependent on CLEC-2/PDPN signaling to prevent blood backflow into the thoracic duct. In addition, platelets regulate lymphangiogenesis and maintain blood/lymphatic separation in pathological conditions, such as wound healing and inflammatory diseases. More recently, it was reported that the entire hemostatic system is involved in lymphangiogenesis. Thus, the hemostatic system plays a crucial role in the establishment, maintenance, and rearrangement of lymphatic networks and contributes to body fluid homeostasis, which suggests that the hemostatic system is a potential target for treating lymphatic disorders. This review comprehensively summarizes the role of the hemostatic system in lymphangiogenesis and lymphatic vessel function and discusses challenges and future perspectives.

Blockade of VEGFR3 signaling leads to functional impairment of dural lymphatic vessels without affecting autoimmune neuroinflammation.

The recent discovery of lymphatic vessels (LVs) in the dura mater, the outermost layer of meninges around the central nervous system (CNS), has opened a possibility for the development of alternative therapeutics for CNS disorders. The vascular endothelial growth factor C (VEGF-C)/VEGF receptor 3 (VEGFR3) signaling pathway is essential for the development and maintenance of dural LVs. However, its significance in mediating dural lymphatic function in CNS autoimmunity is unclear. We show that inhibition of the VEGF-C/VEGFR3 signaling pathway using a monoclonal VEGFR3-blocking antibody, a soluble VEGF-C/D trap, or deletion of the Vegfr3 gene in adult lymphatic endothelium causes notable regression and functional impairment of dural LVs but has no effect on the development of CNS autoimmunity in mice. During autoimmune neuroinflammation, the dura mater was only minimally affected, and neuroinflammation-induced helper T (TH) cell recruitment, activation, and polarization were significantly less pronounced in the dura mater than in the CNS. In support of this notion, during autoimmune neuroinflammation, blood vascular endothelial cells in the cranial and spinal dura expressed lower levels of cell adhesion molecules and chemokines, and antigen-presenting cells (i.e., macrophages and dendritic cells) had lower expression of chemokines, MHC class II-associated molecules, and costimulatory molecules than their counterparts in the brain and spinal cord, respectively. The significantly weaker TH cell responses in the dura mater may explain why dural LVs do not contribute directly to CNS autoimmunity.

The blood vasculature instructs lymphatic patterning in a SOX7‐dependent manner

Despite a growing catalog of secreted factors critical for lymphatic network assembly, little is known about the mechanisms that modulate the expression level of these molecular cues in blood vascular endothelial cells (BECs). Here, we show that a BEC‐specific transcription factor, SOX7, plays a crucial role in a non‐cell‐autonomous manner by modulating the transcription of angiocrine signals to pattern lymphatic vessels. While SOX7 is not expressed in lymphatic endothelial cells (LECs), the conditional loss of SOX7 function in mouse embryos causes a dysmorphic dermal lymphatic phenotype. We identify novel distant regulatory regions in mice and humans that contribute to directly repressing the transcription of a major lymphangiogenic growth factor (Vegfc) in a SOX7‐dependent manner. Further, we show that SOX7 directly binds HEY1, a canonical repressor of the Notch pathway, suggesting that transcriptional repression may also be modulated by the recruitment of this protein partner at Vegfc genomic regulatory regions. Our work unveils a role for SOX7 in modulating downstream signaling events crucial for lymphatic patterning, at least in part via the transcriptional repression of VEGFC levels in the blood vascular endothelium.

TGF-β signaling in lymphatic vascular vessel formation and maintenance.

Transforming growth factor (TGF)-β and its family members, including bone morphogenetic proteins (BMPs), nodal proteins, and activins, are implicated in the development and maintenance of various organs. Here, we review its role in the lymphatic vascular system (the secondary vascular system in vertebrates), which plays a crucial role in various physiological and pathological processes, participating in the maintenance of the normal tissue fluid balance, immune cell trafficking, and fatty acid absorption in the gut. The lymphatic system is associated with pathogenesis in multiple diseases, including lymphedema, inflammatory diseases, and tumor metastasis. Lymphatic vessels are composed of lymphatic endothelial cells, which differentiate from blood vascular endothelial cells (BECs). Although TGF-β family signaling is essential for maintaining blood vessel function, little is known about the role of TGF-β in lymphatic homeostasis. Recently, we reported that endothelial-specific depletion of TGF-β signaling affects lymphatic function. These reports suggest that TGF-β signaling in lymphatic endothelial cells maintains the structure of lymphatic vessels and lymphatic homeostasis, and promotes tumor lymphatic metastasis. Suppression of TGF-β signaling in lymphatic endothelial cells may therefore be effective in inhibiting cancer metastasis. We highlight recent advances in understanding the roles of TGF-β signaling in the formation and maintenance of the lymphatic system.

Features of Lipid Metabolism Disorders in Primary Biliary Cholangitis.

Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune liver disease that mostly affects women. A progressive disorder in the processes of bile secretion and enterohepatic bile salts circulation in patients with PBC already in its early stages, leading to an insufficient release of bile acids into the bowel and their entry into the systemic circulation. Insufficient bile acids released into the duodenum contributes to the development of malabsorption, energy malnutrition, and slowly progressive weight loss. The pathophysiological mechanisms of weight loss and its slow progression are associated with the deterioration of the fat emulsification processes and with the reduced absorption of hydrolyzed products, such as fatty acids and monoglycerides, with steatorrhea in patients with PBC, as well as in those with gut dysbiosis. Just in the early stages of the disease, this results in accelerated fatty acid β-oxidation that is aimed at compensating for progressive energy malnutrition. The entry of bile acids into the systemic circulation in PBC is accompanied by dyslipidemia. The mechanism of hyperlipidemia in patients with PBC differs from that in other conditions because along with an increase in total cholesterol (TC), there are elevated high-density lipoprotein levels and the appearance of unusual lipoprotein X (Lp-X). The appearance of Lp-X is most likely to be the body's protective reaction to inactivate the detergent effect of bile acids on the membrane structures of blood corpuscles and vascular endothelial cells. It is bile acids, rather than TC levels, that correlate with the content of Lp-X and determine its formation. Concomitant hypercholesterolemia in patients with PBC is also aimed at neutralizing the detergent effect of bile acids that have entered the systemic circulation and is most likely a compensatory reaction of the body. "Anomalous" hypercholesterolemia in PBC can serve as a model system for the search and development of new methods for the treatment of dyslipidemia since it occurs without an increase in the incidence of cardiovascular events.

Improved prediction and characterization of blood-brain barrier penetrating peptides using estimated propensity scores of dipeptides.

The blood-brain barrier (BBB) is the primary barrier with a highly selective semipermeable border between blood vascular endothelial cells and the central nervous system. Since BBB can prevent drugs circulating in the blood from crossing into the interstitial fluid of the brain where neurons reside, many researchers are working hard on developing drug delivery systems to penetrate the BBB which currently poses a challenge. Thus, blood-brain barrier penetrating peptides (B3PPs) are an alternative neurotherapeutic for brain-related disorder since they can facilitate drug delivery into the brain. In the meanwhile, developing computational methods that are effective for both the identification and characterization of B3PPs in a cost-effective manner plays an important role for basic reach and in the pharmaceutical industry. Even though few computational methods for B3PP identification have been developed, their performance might fail in terms of generalization ability and interpretability. In this study, a novel and efficient scoring card method-based predictor (termed SCMB3PP) is presented for improving B3PP identification and characterization. To overcome the limitation of black-box computational approaches, the SCMB3PP predictor can automatically estimate amino acid and dipeptide propensities to be B3PPs. Both cross-validation and independent tests indicate that SCMB3PP can achieve impressive performance and outperform various popular machine learning-based methods and the existing methods on multiple independent test datasets. Furthermore, SCMB3PP-derived amino acid propensities were utilized to identify informative biophysical and biochemical properties for characterizing B3PPs. Finally, an online user-friendly web server ( http://pmlabstack.pythonanywhere.com/SCMB3PP ) is established to identify novel and potential B3PP cost-effectively. This novel computational approach is anticipated to facilitate the large-scale identification of high potential B3PP candidates for follow-up experimental validation.

131 Mediators of capillary-to-venule conversion in psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by epidermal hyperplasia and hyperkeratosis, immune cell infiltration and vascular remodeling. Despite the emerging recognition of vascular normalization as a novel strategy in managing psoriasis, an in-depth delineation of the remodeled dermal vasculature has been missing. In the present study, we exploited 5’ single-cell RNA-sequencing (scRNA-seq) to investigate the transcriptomic alterations in different subpopulations of blood vascular and lymphatic endothelial cells (ECs) directly isolated from psoriatic and healthy human skin. Individual subtypes of ECs underwent specific molecular repatterning associated with cell adhesion and extracellular matrix organization. Blood capillaries, in particular, showed upregulation of the melanoma cell adhesion molecule (MCAM) as well as its binding partners and adopted post-capillary venule-like characteristics during chronic inflammation that are more permissive to leukocyte transmigration. We also identified psoriasis-specific interactions between cis-regulatory enhancers and promoters for each EC subtype, revealing the dysregulated gene regulatory networks in psoriasis. Together, our results provide new insights into the specific transcriptional responses and epigenetic signatures of ECs lining different vessel compartments in chronic skin inflammation.

Mediators of Capillary-to-Venule Conversion in the Chronic Inflammatory Skin Disease Psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by epidermal hyperplasia and hyperkeratosis, immune cell infiltration and vascular remodeling. Despite the emerging recognition of vascular normalization as a potential strategy for managing psoriasis, an in-depth delineation of the remodeled dermal vasculature has been missing. In this study, we exploited 5' single-cell RNA sequencing to investigate the transcriptomic alterations in different subpopulations of blood vascular and lymphatic endothelial cells directly isolated from psoriatic and healthy human skin. Individual subtypes of endothelial cells underwent specific molecular repatterning associated with cell adhesion and extracellular matrix organization. Blood capillaries, in particular, showed upregulation of the melanoma cell adhesion molecule as well as its binding partners and adopted postcapillary venule‒like characteristics during chronic inflammation that are more permissive to leukocyte transmigration. We also identified psoriasis-specific interactions between cis-regulatory enhancers and promoters for each endothelial cell subtype, revealing the dysregulated gene regulatory networks in psoriasis. Together, our results provide more insights into the specific transcriptional responses and epigenetic signatures of endothelial cells lining different vessel compartments in chronic skin inflammation.

Sostdc1 Secreted from Cutaneous Lymphatic Vessels Acts as a Paracrine Factor for Hair Follicle Growth.

In our previous study, we found that lymphatic vessels stimulate hair follicle growth through paracrine effects on dermal papilla cells. However, the paracrine factors secreted from cutaneous lymphatic vessels that can activate dermal papilla cells are still unknown. In this study, we investigated whether lymphatic endothelial cells might secrete paracrine factors that activate dermal papilla cells in vitro. We found that Sostdc1 was more expressed in lymphatic endothelial cells compared with blood vascular endothelial cells. In addition, Sostdc1 expression levels were significantly increased during the anagen phase in the back skin of C57BL/6J mice, as compared to the telogen phase. We also observed that incubation of dermal papilla cells with 200 ng/mL Sostdc1 for 72 h induced the expression levels of Lef-1, a downstream target of Wnt signaling. Taken together, our results reveal that Sostdc1, a BMP antagonist, secreted from cutaneous lymphatic vessels, may act as a paracrine factor for hair follicle growth.

Novel Blood Vascular Endothelial Subtype-Specific Markers in Human Skin Unearthed by Single-Cell Transcriptomic Profiling

Ample evidence pinpoints the phenotypic diversity of blood vessels (BVs) and site-specific functions of their lining endothelial cells (ECs). We harnessed single-cell RNA sequencing (scRNA-seq) to dissect the molecular heterogeneity of blood vascular endothelial cells (BECs) in healthy adult human skin and identified six different subpopulations, signifying arterioles, post-arterial capillaries, pre-venular capillaries, post-capillary venules, venules and collecting venules. Individual BEC subtypes exhibited distinctive transcriptomic landscapes associated with diverse biological pathways. These functionally distinct dermal BV segments were characterized by their unique compositions of conventional and novel markers (e.g., arteriole marker GJA5; arteriole capillary markers ASS1 and S100A4; pre-venular capillary markers SOX17 and PLAUR; venular markers EGR2 and LRG1), many of which have been implicated in vascular remodeling upon inflammatory responses. Immunofluorescence staining of human skin sections and whole-mount skin blocks confirmed the discrete expression of these markers along the blood vascular tree in situ, further corroborating BEC heterogeneity in human skin. Overall, our study molecularly refines individual BV compartments, whilst the identification of novel subtype-specific signatures provides more insights for future studies dissecting the responses of distinct vessel segments under pathological conditions.

Circulating Microparticles in the Pathogenesis and Early Anticoagulation of Thrombosis in COVID-19 With Kidney Injury.

As more is learned about the pathophysiological mechanisms of COVID-19, systemic thrombosis has been recognized as being associated with more severe clinical manifestations, mortality and sequelae. As many as 40% of patients admitted to the hospital due to COVID-19 have acute kidney injury, with coagulation abnormalities the main cause of impaired function. However, the mechanism of renal thrombosis and the process leading to kidney injury are unclear. Microparticles (MPs) are membrane bubbles released in response to activation, injury or apoptosis of cells. The phosphatidylserine (PS) exposed on the surface of MPs provides binding sites for endogenous and exogenous FXase complexes and prothrombin complexes, thus providing a platform for the coagulation cascade reaction and facilitating clot formation. In the context of COVID-19 infection, viral attack leads immune cells to release cytokines that damage circulating blood cells and vascular endothelial cells, resulting in increased MPs levels. Therefore, MPs can be used as a risk factor to predict renal microthrombosis and kidney injury. In this paper, we have summarized the latest data on the pathophysiological mechanism and treatment of renal thrombosis caused by MPs in COVID-19, revealing that the coagulation abnormality caused by MP and PS storms is a universal progression that aggravates the mortality and sequelae of COVID-19 and potentially other pandemic diseases. This paper also describes the risk factors affecting renal thrombosis in COVID-19 from the perspective of the Virchow’s triad: blood hypercoagulability, vascular endothelial injury, and decreased blood flow velocity. In summary, given the serious consequences of thrombosis, current guidelines and clinical studies suggest that early prophylactic anticoagulant therapy reduces mortality and improves clinical outcomes. Early anticoagulation, through inhibition of PS-mediated coagulopathy, allows maintenance of unobstructed blood circulation and oxygen delivery thereby facilitating the removal of inflammatory factors, viruses, MPs, and dead or damaged cells, and expediting patient rehabilitation.

Expression of CD44 (NKI-P1) in oral squamous cell carcinoma associated vascular endothelial cells: A relationship to tumor angiogenesis

BackgroundOral squamous cell carcinoma is characterized by high degree of local invasion with metastasis as well as characteristic angiogenic features. Angiogenesis is a critical step in the growth and metastasis of tumors. Cluster of differentiation 44 (CD44) is a cell surface glycoprotein which is widely expressed in both physiological and pathological conditions. AimThe study was designed to assess the expression of CD44 (NKI-P1) in oral squamous cell carcinoma associated endothelial cells and to correlate this expression with matrix metalloprpteinase-9 (MMP-9) and transforming growth factor-beta (TGF- β) expression immunohistochemically. Materials and methodsOne hundred fourteen archival oral squamous cell carcinoma cases were used in this study. Immunohistochemistry was performed for CD44 (NKI-P1), Ki-67, cluster of differentiation 31(CD31), podoplanin (D2-40), MMP-9 and TGF- β. Microvessel density was also determined morphologically. Results: CD44 was expressed in (CD31+/ Podoplanin –) blood vascular endothelial cells in a strong cytoplasmic fashion. In addition, the extracellular matrix proteins (MMP-9 and TGF-β were expressed in oral squamous cell carcinoma stroma which was enriched with CD44 + blood vessels. The mean numbers of microvessel density in connective tissue beneath normal epithelium and different grades of oral squamous cell carcinoma stroma were 5.8, 22.1, 22.4 and 23.5, respectively with the P-value < 0.05, where a significant statistical difference between microvessel density in the connective tissue beneath normal epithelia and stroma of all grades of oral squamous cell carcinoma was found. Conclusion: CD44 (NKI-P1) is considered a potential marker of oral squamous cell carcinoma angiogenesis and it can be used as a valuable biomarker of tumor invasion and as a therapeutic target for anti-angiogenic therapies.

The choice of negative control antisense oligonucleotides dramatically impacts downstream analysis depending on the cellular background

BackgroundThe lymphatic and the blood vasculature are closely related systems that collaborate to ensure the organism’s physiological function. Despite their common developmental origin, they present distinct functional fates in adulthood that rely on robust lineage-specific regulatory programs. The recent technological boost in sequencing approaches unveiled long noncoding RNAs (lncRNAs) as prominent regulatory players of various gene expression levels in a cell-type-specific manner.ResultsTo investigate the potential roles of lncRNAs in vascular biology, we performed antisense oligonucleotide (ASO) knockdowns of lncRNA candidates specifically expressed either in human lymphatic or blood vascular endothelial cells (LECs or BECs) followed by Cap Analysis of Gene Expression (CAGE-Seq). Here, we describe the quality control steps adopted in our analysis pipeline before determining the knockdown effects of three ASOs per lncRNA target on the LEC or BEC transcriptomes. In this regard, we especially observed that the choice of negative control ASOs can dramatically impact the conclusions drawn from the analysis depending on the cellular background.ConclusionIn conclusion, the comparison of negative control ASO effects on the targeted cell type transcriptomes highlights the essential need to select a proper control set of multiple negative control ASO based on the investigated cell types.

Association of Serum Magnesium Levels With Risk of Intracranial Aneurysm

ObjectiveMagnesium has been implicated in regulating blood pressure and vascular endothelial cell function, but its role in the pathophysiology of intracranial aneurysm is not known. Here we performed a Mendelian randomization analysis to investigate the association between serum magnesium concentration and risk of intracranial aneurysm.MethodsFive single-nucleotide polymorphisms strongly associated with serum magnesium concentrations in a genome-wide association study in 23,829 individuals of European ancestry were used as genetic instruments. Genetic association estimates for intracranial aneurysm were obtained from a genome-wide association study in 79,429 individuals (7,495 cases and 71,934 controls). The inverse variance weighted method was used in the primary analyses to obtain the causal estimates.ResultsHigher genetically predicted serum magnesium concentrations were associated with lower risk of intracranial aneurysm. The odds ratios per 0.1 mmol/L increment in genetically predicted serum magnesium concentrations were 0.66 (95% confidence interval [CI] 0.49–0.91) for intracranial aneurysm (unruptured and ruptured combined), 0.57 (95% CI 0.30–1.06) for unruptured intracranial aneurysm, and 0.67 (95% CI 0.48–0.92) for aneurysmal subarachnoid hemorrhage.ConclusionThis study provides evidence to support that increased serum magnesium concentrations reduce the risk of intracranial aneurysm and associated hemorrhage.