Endothelial Cells Of Blood Vessels Research Articles

Contributing factors to endothelial dysfunction in individuals with spinal cord injuries

Background: Patients with spinal cord injuries (SCIs) are at a greater risk for the development of cardiovascular diseases (CVDs) than able-bodied individuals due to high risks of endothelial dysfunction. Summary: For instance, patients with SCIs lose autonomic control of the heart and vasculature, which results in severe fluctuations in blood pressure. These oscillations between hypotension and hypertension have been shown to damage blood vessel endothelial cells and may contribute to the development of atherosclerosis. Furthermore, the loss of skeletal muscle control results in skeletal muscle atrophy and inward remodeling of the conduit arteries. It has been shown that blood vessels in the legs are chronically exposed to high shear, while the aorta experiences chronically low shear. These alterations to shear forces may adversely impact endothelial vasodilatory capacity and promote inflammatory signaling and leukocyte adherence. Additionally, microvascular endothelial vasodilatory capacity is impaired in patients with an SCI, and this may precede changes in conduit artery endothelial function. Finally, due to immobility and a loss of skeletal muscle mass, patients with SCIs have a higher risk of metabolic disorders, inflammation, and oxidative stress. Key Messages: Collectively, these factors may impair endothelium-dependent vasodilatory capacity, promote leukocyte adhesion and infiltration, promote the peroxidation of lipids, and ultimately support the development of atherosclerosis. Therefore, future interventions to prevent CVDs in patients with SCIs should focus on the management of endothelial health to prevent endothelial dysfunction and atherosclerosis.

Abstract 2995: The ectopic expression of miR-380-5p interferes with the aggressive traits of diffuse malignant peritoneal mesothelima cells

Abstract Telomerase activity (TA) and the alternative lengthening of telomere (ALT) pathway are two telomere maintenance mechanisms (TMM) yet identified in human cancers. Although the activation of either TMM seems to be equivalent in supporting tumor cell immortalization (a hallmark of cancer), the contribution of TA and ALT to tumor progression and aggressiveness may be different. Mounting evidence suggests that cancer cell aggressiveness could be associated with a TA↔ALT shift that would allow the acquisition of distinct aggressive traits. We previously showed that an ALT-like phenotype emerged in diffuse malignant peritoneal mesothelioma (DMPM) cells upon miR-380-5p-dependent inhibition of TA (Cimino-Reale G, et al. J Hematol Oncol. 2017). To analyze the transcriptomic changes associated with the emergence of such a phenotype, gene expression profiling was carried out. Results showed that 3331 genes were differentially expressed (FDR<0.05, adjusted for multiple hypothesis testing) in miR-380-5p- vs. preNeg-transfected DMPM cells, out of which 1673 genes were up-regulated and 1658 genes down-regulated. To get biological meaning about the molecular events occurring upon miR-380-5p reconstitution, Gene Set Enrichment Analysis was performed. Results showed a positive enrichment of 188 gene sets, restricted for an FDR < 0.05, out of which signatures related to DNA replication, DNA recombination and telomere maintenance via recombination were present. Conversely, only 1 gene set (GO: positive regulation of blood vessel endothelial cell migration) was negatively enriched at significant level. Notably, among the leading edge genes, PTGS2, which encodes for cyclooxygenase-2 (COX-2) and represents a predicted target of miR-380-5p (miRWalk), was the most significantly down-regulated gene (FDR< 0.000001; log(fold-change): -2.15). Notably, a complete abrogation of PTGS2 expression levels and COX-2 protein amounts was observed in miR-380-5p- compared to preNeg-transfected cells upon validation by qRT-PCR and western blotting, respectively. This evidence was paralleled by reduced amounts of phospho-FAK (focal adhesion kinase) and impaired migrating/invading capabilities of cells ectopically expressing miR-380-5p. Moreover, a reduction of Vimentin and a slight increase in P-Cadherin protein levels were also observed in cells ectopically expressing miR-380-5p, likely indicating the occurrence of a reverse-EMT program. Finally, a pronounced increase in the sensitivity to Cisplatin and Doxorubicin was also appreciable in miR-380-5p- vs. preNeg-transfected cells, suggesting that miRNA-mediated induction of a reverse-EMT may, at least in part, contribute to improve the response of DMPM cells to chemotherapeutic drugs. Citation Format: Stefano Percio, Lorenzo Di Pietro, Eisa Naghshineh, Marcello Deraco, Nadia Zaffaroni, Marco Folini. The ectopic expression of miR-380-5p interferes with the aggressive traits of diffuse malignant peritoneal mesothelima cells [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 2995.

THBS1 promotes angiogenesis and accelerates ESCC malignant progression by the HIF-1/VEGF signaling pathway.

Previously, we demonstrated that the expression of THBS1 is increased in esophageal squamous cell carcinoma (ESCC) tissues and is correlated with lymph node metastasis and poor prognosis, indicating that THBS1 might be a candidate oncogene in ESCC. In this study, we future studied the specific role of THBS1 in ESCC and its molecular mechanism. Silencing THBS1 expression resulted in inhibition of cell migration and cell invasion of ESCC cells, the decrease of colony formation and proliferation. Tube formation of human umbilical vein endothelial cells (HUVECs) in vitro was decreased when cultured with conditioned medium from THBS1-silenced cells. The expression of CD31, a marker for blood vessel endothelial cells, was decreased in tumor tissues derived from THBS1-silenced tumors in vivo. Silencing THBS1 leaded the decreased of hypoxia-inducible factor-1α (HIF-1α), HIF-1β, and VEGFA protein. The expression of p-ERK and p-AKT were declined in HUVECs following incubation with conditioned medium from THBS1-silenced ESCC cells compared conditioned medium from control cells. Furthermore, the treatment with bevacizumab boosted the decrease of the p-ERK and p-AKT levels in HUVECs incubated with the conditioned medium from THBS1-silenced ESCC cells. THBS1 silencing combined with bevacizumab blocked VEGF, inhibited to the tube formation, colony formation and migration of HUVECs, which were superior to that of bevacizumab alone. We presumed that THBS1 can enhance HIF-1/VEGF signaling and subsequently induce angiogenesis by activating the AKT and ERK pathways in HUVECs, resulting in bevacizumab resistance. THBS1 would be a potential target in tumor antiangiogenesis therapies.

Neddylation suppression by a macrophage membrane-coated nanoparticle promotes dual immunomodulatory repair of diabetic wounds

Oxidative stress, infection, and vasculopathy caused by hyperglycemia are the main barriers for the rapid repair of foot ulcers in patients with diabetes mellitus (DM). In recent times, the discovery of neddylation, a new type of post-translational modification, has been found to regulate various crucial biological processes including cell metabolism and the cell cycle. Nevertheless, its capacity to control the healing of wounds in diabetic patients remains unknown. This study shows that MLN49224, a compound that inhibits neddylation at low concentrations, enhances the healing of diabetic wounds by inhibiting the polarization of M1 macrophages and reducing the secretion of inflammatory factors. Moreover, it concurrently stimulates the growth, movement, and formation of blood vessel endothelial cells, leading to expedited healing of wounds in individuals with diabetes. The drug is loaded into biomimetic macrophage-membrane-coated PLGA nanoparticles (M-NPs/MLN4924). The membrane of macrophages shields nanoparticles from being eliminated in the reticuloendothelial system and counteracts the proinflammatory cytokines to alleviate inflammation in the surrounding area. The extended discharge of MLN4924 from M-NPs/MLN4924 stimulates the growth of endothelial cells and the formation of tubes, along with the polarization of macrophages towards the anti-inflammatory M2 phenotype. By loading M-NPs/MLN4924 into a hydrogel, the final formulation is able to meaningfully repair a diabetic wound, suggesting that M-NPs/MLN4924 is a promising engineered nanoplatform for tissue engineering.

Hypoxia-inducible factors: details create a picture. Part II. HIF-2

This review presents current information on the role of hypoxia-inducible factor-2 (HIF-2) under conditions of physiological tissue hypoxia and pathological hypoxic conditions. The structural and functional features of HIF-2 subunits (HIF-2α and HIF-β) and methods of their regulation under conditions of normoxia and hypoxia are described. The spectrum of cells expressing HIF-2α is quite diverse: endothelial cells of blood vessels, kidney fibroblasts, hepatocytes, interstitial cells (telocytes) of the pancreas, epithelial cells lining the intestinal mucosa, type II alveolocytes, glial cells, derivatives of neural crest cells (chromaffinocytes of the adrenal gland). HIF-2α -dependent transcriptional effects are highly locus specific and occur only under certain circumstances. Regulation of HIF-2α translation can be accomplished by two classes of regulatory molecules (RNA-binding proteins and mR-NAs) by altering the rate of translation due to binding to the 3' or 5' untranslated region of mRNA (3' or 5' UTR) of specific targets. HIF-2α activity is regulated primarily at the post-translational level by various signaling mechanisms at the level of mRNA expression, mRNA translation, protein stability, and transcriptional activity. Under normoxia, the canonical regulation of HIF-2α activity is determined by oxygen-dependent mechanisms, and under hypoxia conditions - by non-canonical (oxygen-independent) mechanisms, through phosphorylation, SUMOlyated, acetylation, methylation, etc., causing positive and negative effects. It has been established that HIF influences signaling pathways affecting embryonic development, metabolism, inflammation and the physiology of functional systems, and also works in long-term responses to chronic hypoxia, during which it regulates angiogenesis, glucose, iron, lipid metabolism, cell cycle, metastasis and other processes. Studying changes in the intracellular content of HIF-2α and the transcriptional activity of HIF-2 will allow us to develop effective methods for correcting various diseases accompanied by systemic and local oxygen deficiency.

Simple design for membrane-free microphysiological systems to model the blood-tissue barriers

Microphysiological systems (MPS) incorporate physiologically relevant microanatomy, mechanics, and cells to mimic tissue function. Reproducible and standardized in vitro models of tissue barriers, such as the blood-tissue interface (BTI), are critical for next-generation MPS applications in research and industry. Many models of the BTI are limited by the need for semipermeable membranes, use of homogenous cell populations, or 2D culture. These factors limit the relevant endothelial-epithelial contact and 3D transport, which would best mimic the BTI. Current models are also difficult to assemble, requiring precise alignment and layering of components. The work reported herein details the engineering of a BTI-on-a-chip (BTI Chip) that addresses current disadvantages by demonstrating a single layer, membrane-free design. Laminar flow profiles, photocurable hydrogel scaffolds, and human cell lines were used to construct a BTI Chip that juxtaposes an endothelium in direct contact with a 3D engineered tissue. A biomaterial composite, gelatin methacryloyl and 8-arm polyethylene glycol thiol, was used for in situ fabrication of a tissue structure within a Y-shaped microfluidic device. To produce the BTI, a laminar flow profile was achieved by flowing a photocurable precursor solution alongside phosphate buffered saline. Immediately after stopping flow, the scaffold underwent polymerization through a rapid exposure to UV light (<300 mJ/cm2). After scaffold formation, blood vessel endothelial cells were introduced and allowed to adhere directly to the 3D tissue scaffold, without barriers or phase guides. Fabrication of the BTI Chip was demonstrated in both an epithelial tissue model and blood-brain barrier (BBB) model. In the epithelial model, scaffolds were seeded with human dermal fibroblasts. For the BBB models, scaffolds were seeded with the immortalized glial cell line, SVGP12. The BTI Chip microanatomy was analyzed post facto by immunohistochemistry, showing the uniform production of a patent endothelium juxtaposed with a 3D engineered tissue. Fluorescent tracer molecules were used to characterize the permeability of the BTI Chip. The BTI Chips were challenged with an efflux pump inhibitor, cyclosporine A, to assess physiological function and endothelial cell activation. Operation of physiologically relevant BTI Chips and a novel means for high-throughput MPS generation was demonstrated, enabling future development for drug candidate screening and fundamental biological investigations.

Charting the genetic architecture of Alzheimer’s disease across APOE*4 and sex

AbstractBackgroundAPOE*4 status and sex (and their interaction) are among the strongest risk factors for late‐onset Alzheimer’s disease (AD). We thus sought to perform large‐scale, stratified genome‐wide association study (GWAS) of AD to chart the role of common genetic variation in AD sexual dimorphism and heterogeneity of APOE*4‐related AD risk.MethodThe study overview and GWAS models are shown in Figure.1A. SNP‐array AD GWAS datasets primarily composing the ADGC, together with whole‐genome sequencing (WGS) from ADSP (NG00067.v7), provided case‐control diagnoses for phase‐1. The UK Biobank provided subjects with ICD codes and family history of AD status for phase‐2. Subjects were of European ancestry. Linear mixed model regressions were performed (LMM‐BOLT v.2.3.4) on AD outcome measures, adjusting for sex, APOE*4/APOE*2 dosage, genetic principal components, and array/batch/center. GWAS hits (P&lt;5e‐*8) were evaluated for interactions effects (meta‐regression for phase1+2 meta‐analyses) and assessed in functional follow‐up analyses. The effect of stratification on genetic risk scores (GRS) predictive performance on AD risk was also evaluated.ResultStratified AD GWAS identified 28 loci/variants, including 5 known lead variants in known AD loci, 6 novel independent variants in known AD loci, and 17 novel loci (Figure.1B). 13 out of 17 novel loci showed varying degrees of functional support, with 4 also showing evidence for QTL colocalization (Figure.2). Many implicated genes showed prior support or effects relevant to AD: MARCHF10 was recently implicated as a risk gene for all‐cause dementia; EMP2 is a regulator of cell membrane composition, cell‐matrix adhesion, and blood vessel endothelial cell migration; SLIT2 binds APP, and EYA4 and TBC1D9 have respectively been implicated in brain tau deposition and MAPT haplotype‐stratified GWAS. Nonetheless, most novel hits were low/uncommon frequency variants and QTL colocalization evidence was limited. Further, there appeared to be no predictive benefit for stratified GRS analyses (Figure.3).ConclusionWe identified novel loci/variants differentially associated with AD risk across APOE*4 and/or sex. Yet, we inferred relatively limited evidence for stratified effects (propensity for low frequency hits and no benefit for stratified GRS). Overall, our findings contribute to our understanding of the genetic etiology of AD, which in turn contributes to advance personalized genetic medicine.

Primary pericardial angiosarcoma with pleural metastasis: an unusual clinical presentation

Abstract Introduction/Objective Primary pericardial angiosarcoma is an uncommon, aggressive cardiac neoplasm that arises from the endothelial cells of blood vessels. It typically affects middle-aged men and has a poor prognosis due to early metastasis. Unfortunately, there are currently no established guidelines or effective treatments for this rare malignancy. The purpose of this case study is to emphasize the significance of recognizing the unspecific presentations of pericardial angiosarcoma and ensuring timely diagnosis and appropriate treatment. Methods/Case Report A 56-year-old male presented with recurrent pericardial effusion and exudative pleural effusion. The radiologic studies showed a thickened pericardium with right-sided pericardial effusion and a large right- sided pleural effusion. Resected partial pericardium and parietal pleura showed the presence of epithelioid to spindled cells that formed solid sheets and vascular structures filled with numerous red blood cells. The tumor cells were cytologically malignant, with angulated shapes and hyperchromatic nuclei, and showed extensive invasion into the surrounding connective tissue. Mitotic figures were variably visualized, and there was abundant hemorrhage. Immunohistochemical analysis of the lesional cells showed positivity for ERG, CD31, Factor VIII, and retention of Methylthioadenosine phosphorylase (MTAP) and BRCA1-associated protein 1 (BAP1), while they were negative for WT1, calretinin, claudin-4, and p40. Based on the morphology and immunoprofile, a diagnosis of high grade angiosarcoma was rendered, and the patient underwent chemotherapy. The overall survival of the patient was 8 months to date. Results (if a Case Study enter NA) NA Conclusion Prompt diagnosis of pericardial angiosarcoma is crucial, as nonspecific symptoms may lead to misdiagnosis, such as in this case where the patient was initially diagnosed with pericarditis. Video-assisted thoracic surgery and histologic analysis are necessary to reach a correct diagnosis, which ensures appropriate treatment, as a delayed diagnosis can worsen the prognosis and even lead to death.

Release of miR-29 Target Laminin C2 Improves Skin Repair

miRNAs are small noncoding RNAs that regulate mRNA targets in a cell-specific manner. miR-29 is expressed in murine and human skin, where it may regulate functions in skin repair. Cutaneous wound healing model in miR-29a/b1 gene knockout mice was used to identify miR-29 targets in the wound matrix, where angiogenesis and maturation of provisional granulation tissue was enhanced in response to genetic deletion of miR-29. Consistently, antisense-mediated inhibition of miR-29 promoted angiogenesis invitro by autocrine and paracrine mechanisms. These processes are likely mediated by miR-29 target mRNAs released upon removal of miR-29 to improve cell-matrix adhesion. One of these, laminin (Lam)-c2 (also known as laminin γ2), was strongly up-regulated during skin repair in the wound matrix of knockout mice. Unexpectedly, Lamc2 was deposited in the basal membrane of endothelial cells in blood vessels forming in the granulation tissue of knockout mice. New blood vessels showed punctate interactions between Lamc2 and integrin α6 (Itga6) along the length of the proto-vessels, suggesting that greater levels of Lamc2 may contribute to the adhesion of endothelial cells, thus assisting angiogenesis within the wound. These findings may be of translational relevance, as LAMC2 was deposited at the leading edge in human wounds, where it formed a basal membrane for endothelial cells and assisted neovascularization. These results suggest a link between LAMC2, improved angiogenesis, and re-epithelialization.

Angiopoietin-2 blockade suppresses growth of liver metastases from pancreatic neuroendocrine tumors by promoting T cell recruitment.

Improving the management of metastasis in pancreatic neuroendocrine tumors (PanNETs) is critical, as nearly half of patients with PanNETs present with liver metastases, and this accounts for the majority of patient mortality. We identified angiopoietin-2 (ANGPT2) as one of the most upregulated angiogenic factors in RNA-Seq data from human PanNET liver metastases and found that higher ANGPT2 expression correlated with poor survival rates. Immunohistochemical staining revealed that ANGPT2 was localized to the endothelial cells of blood vessels in PanNET liver metastases. We observed an association between the upregulation of endothelial ANGPT2 and liver metastatic progression in both patients and transgenic mouse models of PanNETs. In human and mouse PanNET liver metastases, ANGPT2 upregulation coincided with poor T cell infiltration, indicative of an immunosuppressive tumor microenvironment. Notably, both pharmacologic inhibition and genetic deletion of ANGPT2 in PanNET mouse models slowed the growth of PanNET liver metastases. Furthermore, pharmacologic inhibition of ANGPT2 promoted T cell infiltration and activation in liver metastases, improving the survival of mice with metastatic PanNETs. These changes were accompanied by reduced plasma leakage and improved vascular integrity in metastases. Together, these findings suggest that ANGPT2 blockade may be an effective strategy for promoting T cell infiltration and immunostimulatory reprogramming to reduce the growth of liver metastases in PanNETs.

Vedolizumab Efficacy Is Associated With Decreased Intracolonic Dendritic Cells, Not Memory T Cells.

Vedolizumab, an antibody blocking integrin α4β7, is a safe and effective therapy for Crohn's disease and ulcerative colitis. Blocking α4β7 from binding its cognate addressin MAdCAM-1 on intestinal blood vessel endothelial cells prevents T cells from migrating to the gut mucosa in animal models. However, data supporting this mechanism of action in humans is limited. We conducted a cross-sectional case-control study to evaluate the effect of vedolizumab on intestinal immune cell populations while avoiding the confounding effect of resolving inflammation on the cellularity of the colonic mucosa in treatment-responsive patients. Colon biopsies from 65 case subjects receiving vedolizumab were matched with biopsies from 65 control individuals, similar in disease type, medications, anatomic location, and inflammation. Biopsies were analyzed by flow cytometry and full messenger RNA transcriptome sequencing of sorted T cells. No difference was seen between vedolizumab recipients and control individuals in the quantity of any antigen-experienced T lymphocyte subset or in the quality of the transcriptome in any experienced T cell subset. Fewer naïve colonic B and T cells were seen in vedolizumab recipients than control individuals, regardless of response. However, the most striking finding was a marked reduction in CD1c+ (BDCA1+) dendritic cells exclusively in vedolizumab-responsive patients. In blood, these dendritic cells ubiquitously express high levels of α4β7, which is rapidly downregulated upon vedolizumab exposure. The clinical effects of vedolizumab reveal integrin α4β7-dependent dendritic cell migration to the intestinal mucosa to be central to inflammatory bowel disease pathogenesis.

Стрес і гіпертензія за умов війни та COVID-19

Common mechanisms of the development of the body’s stress response under the conditions of war and the COVID-19 pandemic relate to its acute and chronic course, post-traumatic stress disorder, the role of the hypothalamus-pituitaryadrenal gland, the sympathetic nervous system, and the renin-angiotensin-aldosterone system, and deficiency of α-1- antitrypsin. The development of stress-induced hypertensive changes is characterized by the activity of enzymes independent of the angiotensin-converting enzyme pathway of the renin-angiotensin system, expression of miRNA, damage to the endothelial cells of blood vessels, changes in the content of neutrophils and lymphocytes, and the soluble receptor for glycosylation end products. The considered stress-induced hypertensive changes under the conditions of the COVID-19 pandemic relate to chronic hyperinflammation, emotional response, effects of catecholamines, chymase activity, redox imbalance, DNA damage, endoplasmic reticulum stress. The interaction between ACE/ACE2 and miRNA may increase the probability of SARS-CoV-2 infection in patients with hypertension. A factor in the severity of COVID-19 is considered to be clinical depression and low immunity, and the possibility of a negative effect of antidepressants is highlighted. A more aggressive course of COVID-19 in hypertensive patients is associated with low levels of nitric oxide (NO). Stress-induced hypertensive changes under the conditions of war are associated with adaptation disorders, increased randomness of heart rate changes, post-traumatic stress disorder, the development of hypertension partly of psychological origin against the background of changes in the central nervous system, immunity, and the polymorphism of the ACEI/D gene as an indicator of endurance.

Mammary hemangiosarcoma: report of histopathological examination

Hemangiosarcoma (HSA) is a common form of neoplasm in dogs, characterized by the malignant growth of endothelial cells in blood vessels. This neoplasm is highly aggressive and often shows metastatic behavior, with tropism for well-vascularized tissues and characterized by fragile capillaries, leading to hemorrhagic conditions, causing the death of most affected animals, as well as causing a series of hematological abnormalities. Diagnosis can be made by cytology and confirmed by histopathological examination. Treatment is comprised of surgical removal of the affected nodule or organ, accompanied by chemotherapy protocols. A histopathological examination was carried out on a cutaneous tumor in the mammary area of a seven-year-old Dachshund bitch, which was diagnosed as a hemangiosarcoma. The aim of this paper is to report a case of canine mammary hemangiosarcoma and to show the importance of histopathological examination in routine veterinary medicine diagnoses.

Clinical value of serum miR-1-3p as a potential circulating biomarker for abdominal aortic aneurysm

Background Although abdominal aortic aneurysm (AAA) is associated with life-threatening complications, there are still limited reliable biomarkers for diagnostic purpose. MicroRNAs (miRNAs) have been proposed as the potential diagnostic and risk stratification markers of AAA patients, and we aim to evaluate the serum level of miR-1-3p and its diagnostic value in AAA. Methods This study included 200 AAA patients and 200 controls. Demographic data and clinical information were collected from the subjects’ medical records. Individual image analyses of AAA morphology were determined based on computed tomography angiography (CTA). The levels of serum miRNA expression were detected by quantitative real-time PCR. Bioinformatics tools were used to identify the target genes of miR-1-3p and their potential biological functions were further enriched. Results Serum miR-1-3p levels in the AAA group were significantly lower when compared with those in the control group in overall and subgroup comparisons. It was negatively related to WBC, CRP, maximal aneurysm diameter, area, and volume in AAA patients. Circulating miR-1-3p levels could significantly discriminate between AAA patients and healthy individuals with an area under the curve (AUC) of 0.672 (95% CI = 0.619-0.724, p < 0.001), a sensitivity of 84.5% and a specificity of 45.5%. Serum miR-1-3p was associated with a reduced risk of AAA even after adjustment for possible risk factors (OR = 0.440 per unit increase, 95% CI = 0.301-0.643, p < 0.001). And low levels of serum miR-1-3p could significantly elevate the risk of AAA in both univariate and multivariate logistic regression analyses with ORs of 4.076 and 4.136, respectively (all p < 0.001). Further GO enrichment analysis revealed that miR-1-3p was mainly involved in negative regulation of apoptotic process, sprouting angiogenesis, angiogenesis, positive regulation of blood vessel endothelial cell migration, positive regulation of cell proliferation, regulation of cell shape, etc. Conclusions MiR-1-3p can be used as a promising circulating biomarker in the development of AAA, and it may participate in multiple biological processes to play a crucial role in AAA pathogenesis.

Unique miRNome and transcriptome profiles underlie microvascular heterogeneity in mouse kidney.

Endothelial cells in blood vessels in the kidney exert different functions depending on the (micro)vascular bed they are located in. The present study aimed to investigate microRNA and mRNA transcription patterns that underlie these differences. We zoomed in on microvascular compartments in the mouse renal cortex by laser microdissecting the microvessels prior to small RNA- and RNA-sequencing analyses. By these means, we characterized microRNA and mRNA transcription profiles of arterioles, glomeruli, peritubular capillaries, and postcapillary venules. Quantitative RT-PCR, in situ hybridization, and immunohistochemistry were used to validate sequencing results. Unique microRNA and mRNA transcription profiles were found in all microvascular compartments, with dedicated marker microRNAs and mRNAs showing enriched transcription in a single microvascular compartment. In situ hybridization validated the localization of microRNAs mmu-miR-140-3p in arterioles, mmu-miR-322-3p in glomeruli, and mmu-miR-451a in postcapillary venules. Immunohistochemical staining showed that von Willebrand factor protein was mainly expressed in arterioles and postcapillary venules, whereas GABRB1 expression was enriched in glomeruli, and IGF1 was enriched in postcapillary venules. More than 550 compartment-specific microRNA-mRNA interaction pairs were identified that carry functional implications for microvascular behavior. In conclusion, our study identified unique microRNA and mRNA transcription patterns in microvascular compartments of the mouse kidney cortex that underlie microvascular heterogeneity. These patterns provide important molecular information for future studies into differential microvascular engagement in health and disease.NEW & NOTEWORTHY Renal endothelial cells display a high level of heterogeneity depending on the (micro)vascular bed they reside in. The molecular basis contributing to these differences is poorly understood yet of high importance to increase understanding of microvascular engagement in the kidney in health and disease. This report describes m(icro)RNA expression profiles of microvascular beds in the mouse renal cortex and uncovers microvascular compartment-specific m(icro)RNAs and miRNA-mRNA pairs, thereby revealing important molecular mechanisms underlying renal microvascular heterogeneity.

TRPM7 Mediates BSCB Disruption After Spinal Cord Injury by Regulating the mTOR/JMJD3 Axis in Rats.

After spinal cord injury (SCI), secondary injuries including blood cells infiltration followed by the production of inflammatory mediators are led by blood-spinal cord barrier (BSCB) breakdown. Therefore, preventing BSCB damage could alleviate the secondary injury progresses after SCI. Recently, we reported that transient receptor potential melastatin 7 channel (TRPM7) expression is increased in vascular endothelial cells after injury and thereby mediates BSCB disruption. However, the mechanism by which TRPM7 regulates BSCB disruption has not been examined yet. In current research, we show that TRPM7 mediates BSCB disruption via mammalian target of rapamycin (mTOR) pathway after SCI in rats. After contusion injury at T9 level of spinal cord, mTOR pathway was activated in the endothelial cells of blood vessels and TRPM7 was involved in the activation of mTOR pathway. BSCB disruption, MMP-2/9 activation, and blood cell infiltration after injury were alleviated by rapamycin, a mTOR signaling inhibitor. Rapamycin also conserved the level of tight junction proteins, which were decreased after SCI. Furthermore, mTOR pathway regulated the expression and activation of histone H3K27 demethylase JMJD3, known as a key epigenetic regulator mediating BSCB damage after SCI. In addition, rapamycin inhibited JMJD3 expression, the loss of tight junction molecules, and MMP-2/9 expression in bEnd.3, a brain endothelial cell line, after oxygen-glucose deprivation/reoxygenation. Thus, our results suggest that TRPM7 contributes to the BSCB disruption by regulating JMJD3 expression through the mTOR pathway after SCI.

Abstract B001: Calcitonin receptor-like receptor agonists induce p44/42 MAPK phosphorylation in VEGF-A-stimulated human blood endothelial cells after bevacizumab treatment

Abstract Introduction. Clear cell renal cell carcinoma (ccRCC) is a highly vascularized and clinically aggressive cancer. In the UK, there are around 9000 diagnoses and 3000 deaths annually. Targeted therapies that inhibit angiogenic regulators, such as bevacizumab (monoclonal antibody which inhibits vascular endothelial growth factor A, VEGF-A), have limited efficacy due to drug resistance. Expression of calcitonin receptor-like receptor (CLR) is upregulated in ccRCC and correlates with disease outcome. The expression of adrenomedullin (AM), peptide agonist of CLR and angiogenic factor, is upregulated in ccRCC. We hypothesized that the CLR signaling axis acts as an alternative pathway that enables resistance to drugs targeting the VEGF-A pathway in ccRCC. In the present study, we aimed to determine whether this signaling axis remains active in VEGF-A-stimulated and bevacizumab-treated human endothelial cells. Methods. Primary human dermal blood vessel endothelial cells (HDBEC; PromoCell) were characterized by immunofluorescence utilizing pan-endothelial (cluster of differentiation 31 and 144, CD31 and CD144, and von Willebrand factor, vWF) and lymphatic-specific (lymphatic vessel endothelial hyaluronan receptor 1, LYVE-1, and prospero homeobox 1, PROX1) markers and confocal microscopy. The activities of CLR agonists (AM; intermedin, IMD; calcitonin gene-related peptide, CGRP; 10−12 - 10−6 M at 10 min) and VEGF-A (50 ng/ml over 30-minute time course) were measured by analyzing phosphorylation of p44/42 mitogen-activated protein kinases (MAPK) using immunoblotting. HDBEC were pre-treated with bevacizumab or human IgG1 at 250 ng/ml and then stimulated with individual CLR agonists at 10−6 M for 10 minutes. Experiments were repeated at least three times. Data were analyzed using Shapiro-Wilk normality, unpaired statistics and appropriate multiple comparisons tests utilizing GraphPad Prism and p&amp;lt;0.05 interpreted as significant. Results. HDBEC were a pure population. AM, IMD and CGRP induced p44/42 MAPK phosphorylation at 10−6 M (p&amp;lt;0.05). For all three CLR agonists and VEGF-A, p44/42 MAPK phosphorylation peaked after 10 minutes of incubation (p&amp;lt;0.05). Bevacizumab treatment at 250 ng/ml was sufficient to inhibit VEGF-A-induced p44/42 MAPK phosphorylation (p&amp;lt;0.05). AM, IMD and CGRP were all able to induce phosphorylation of p44/42 MAPK after bevacizumab treatment (p&amp;lt;0.01). Conclusions. The findings that CLR agonists induce p44/42 MAPK phosphorylation in VEGF-A-stimulated HDBEC after bevacizumab treatment support our hypothesis. This work provides a foundation for investigating the role of the CLR signaling axis in mechanisms of ccRCC resistance to drugs targeting the VEGF-A pathway. Citation Format: Matthew A. Morfitt, John Greenman, Anthony Maraveyas, Leonid L. Nikitenko. Calcitonin receptor-like receptor agonists induce p44/42 MAPK phosphorylation in VEGF-A-stimulated human blood endothelial cells after bevacizumab treatment [abstract]. In: Proceedings of the AACR Special Conference: Advances in Kidney Cancer Research; 2023 Jun 24-27; Austin, Texas. Philadelphia (PA): AACR; Cancer Res 2023;83(16 Suppl):Abstract nr B001.

Multiple post-radiation angiosarcoma of the breast: rare clinical case

This article describes the rare clinical case of multiple radiation-induced angiosarcoma of the breast. Angiosarcoma is a rare, aggressive tumor originating from the endothelial cells of blood vessels that can affect internal organs, but the most common localization is the skin. The frequency of angiosarcoma development in the mammary gland is less than 1% of all malignant tumors of this localization. There are primary and radiation-induced (secondary) angiosarcomas. The reason for describing this clinical case is the rarity of this pathology, relatively little experience in the diagnosis and treatment of radiation-induced angiosarcoma both in our country and abroad.

#3145 ASSOCIATION OF ENDOTHELIAL NITRIC OXIDE SYNTHASE GENE POLYMORPHISM WITH ENDOTHELIAL DYSFUNCTION IN DIABETIC NEPHROPATHY AMONG AZERBAIJANIS

Abstract Background and Aims Vascular endothelial dysfunction resulting from impaired nitric oxide synthase (NOS) activity in the endothelial cells of blood vessels has been suggested as playing an important role in the pathogenesis of Diabetic nephropathy (DN). It regulates endothelial function and maintains endothelial-dependent vasodilation in multiple organs, including the kidney. The study was carried out to investigate the association of T-786C single nucleotide polymorphisms with the flow mediated dilation (FMD) in DN among type 2 diabetic subjects. Method 90 patients (45 male and 45 female) with diabetic nephropathy were recruited from Nephrology and Endocrinology departments of the Azerbaijan Medical University hospital. As a control group the results were compared with the findings in 100 healthy Azerbaijani individuals (50 males and 50 females). The study was approved by ethics committee and informed consent was obtained from all patients in written form. Brachial endothelial function was determined by brachial artery vasodilator response or brachial FMD in the dominant arm according to previously validated techniques. T786C polymorphism was detected using polymerase chain reaction-restriction fragment length polymorphism analysis. Results The results showed significant differences between DN group and control group regarding the genotype and allele distributions of the T786C single nucleotide polymorphisms. The CC genotype was significantly more frequent in diabetics nephropathy patients than in control group (42% vs. 8%, p = 0.01). FMD in allele homozygote T786C(TT), T786C(CC) and heterozygote T786C(CT) were respectively 13.5 ±0.16%, 12.3±0.19%,13.9 ±0,28%. In the study groups, Azerbaijani patients showed dominance of the C allele and a mutant homozygous genotype CC of the T786C gene of eNOS. Subjects with the 786C(CC) (n = 48) showed significantly reduced FMD with those with T786C (TT) (n = 7) (p = 0.021) and T786C (CT) (n = 35) (p = 0.023), whereas there was no significant difference in endothelial-independent vasodilation between these groups. Although subjects with homozygote T786C(TT), did not show significantly reduced levels of FMD. Who were carriers of the T786C allele demonstrated markedly reduced levels of FMD compared with noncarriers (p = 0.019). Conclusion The data suggest that in diabetic nephropathy, the eNOS T786C allele may be involved in endothelial dysfunction. Azerbaijani patients showed dominance of the C allele and a mutant homozygous genotype CC of the T786C gene of eNOS.

Ultrasound features of splenic hemangiosarcoma in dogs: Review

Ultrasonography is a diagnostic imaging method widely used in veterinary medicine, thus allowing for the evaluation of various organs in real time. Abdominal ultrasonography is fundamental to evaluate abdominal organs, such as the spleen, which has important functions in the body of animals and is predisposed to various pathological processes, including neoplastic ones. The most common splenic neoplasm is hemangiosarcoma, which is a tumor originating from endothelial cells of blood vessels, highly malignant and metastatic, which occurs more frequently in dogs with an average age of 9 to 12 years, and the most predisposed breeds are German Shepherds, Golden Retrievers, Labrador Retrievers and Schnauzers. The etiology of hemangiosarcoma in dogs remains uncertain and clinical signs are generally nonspecific, varying according to the site of origin of the primary tumor, the presence or absence of metastases and spontaneous rupture of the tumor. The diagnosis of this condition is made through the patient’s history and clinical signs, physical examination and complementary tests, thus allowing for an accurate assessment of the stage of the patient's disease. Abdominal ultrasound is important to detect splenic hemangiosarcoma, which is identified by its complex and heterogeneous echogenicity, consisting of anechogenic, hypoechogenic and hyperechogenic areas, caused by hemorrhage, necrosis and fibrotic or calcified tissue, and is often accompanied by peritoneal fluid. In addition, the ultrasound assists in directing the treatment and consequently improves the patient's quality of life. However, the definitive diagnosis can only be obtained through histopathological analysis of samples collected by ultrasound-guided biopsy or after splenectomy. Usually, the prognosis for hemangiosarcoma is poor. The objective of this work is to describe the sonographic features found in splenic hemangiosarcomas in dogs.