Angiotensin II Directly Increases Endothelial Calcium and Nitric Oxide in Kidney and Brain Microvessels In Vivo With Reduced Efficacy in Hypertension.

BACKGROUND: The vasoconstrictor effects of angiotensin II via type 1 angiotensin II receptors in vascular smooth muscle cells are well established, but the direct effects of angiotensin II on vascular endothelial cells (VECs) in vivo and the mechanisms how VECs may mitigate angiotensin II-mediated vasoconstriction are not fully understood. The present study aimed to explore the molecular mechanisms and pathophysiological relevance of the direct actions of angiotensin II on VECs in kidney and brain microvessels in vivo. METHODS AND RESULTS: Changes in VEC intracellular calcium ([Ca2+]i) and nitric oxide (NO) production were visualized by intravital multiphoton microscopy of cadherin 5-Salsa6f mice or the endothelial uptake of NO-sensitive dye 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate, respectively. Kidney fibrosis by unilateral ureteral obstruction and Ready-to-use adeno-associated virus expressing Mouse Renin 1 gene (Ren1-AAV) hypertension were used as disease models. Acute systemic angiotensin II injections triggered >4-fold increases in VEC [Ca2+]i in brain and kidney resistance arterioles and capillaries that were blocked by pretreatment with the type 1 angiotensin II receptor inhibitor losartan, but not by the type 2 angiotensin II receptor inhibitor PD123319. VEC responded to acute angiotensin II by increased NO production as indicated by >1.5-fold increase in 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate fluorescence intensity. In mice with kidney fibrosis or hypertension, the angiotensin II-induced VEC [Ca2+]i and NO responses were significantly reduced, which was associated with more robust vasoconstrictions, VEC shedding, and microthrombi formation. CONCLUSIONS: The present study directly visualized angiotensin II-induced increases in VEC [Ca2+]i and NO production that serve to counterbalance agonist-induced vasoconstriction and maintain residual organ blood flow. These direct and endothelium-specific angiotensin II effects were blunted in disease conditions and linked to endothelial dysfunction and the development of vascular pathologies.

IGSF3 is a homophilic cell adhesion molecule that drives lung metastasis of melanoma by promoting adhesion to vascular endothelium.

The immunoglobulin superfamily (IgSF) is one of the largest families of cell-surface molecules involved in various cell-cell interactions, including cancer-stromal interactions. In this study, we undertook a comprehensive RT-PCR-based screening for IgSF molecules that promote experimental lung metastasis in mice. By comparing the expression of 325 genes encoding cell-surface IgSF molecules between mouse melanoma B16 cells and its highly metastatic subline, B16F10 cells, we found that expression of the immunoglobulin superfamily member 3 gene (Igsf3) was significantly enhanced in B16F10 cells than in B16 cells. Knockdown of Igsf3 in B16F10 cells significantly reduced lung metastasis following intravenous injection into C57BL/6 mice. IGSF3 promoted adhesion of B16F10 cells to vascular endothelial cells and functioned as a homophilic cell adhesion molecule between B16F10 cells and vascular endothelial cells. Notably, the knockdown of IGSF3 in either B16F10 cells or vascular endothelial cells suppressed the transendothelial migration of B16F10 cells. Moreover, IGSF3 knockdown suppressed the extravasation of B16F10 cells into the lungs after intravenous injection. These results suggest that IGSF3 promotes the metastatic potential of B16F10 cells in the lungs by facilitating their adhesion to vascular endothelial cells.

Multifaceted roles of Meg3 in cellular senescence and atherosclerosis.

BACKGROUND AND AIMS: Long noncoding RNAs are involved in the pathogenesis of atherosclerosis. As long noncoding RNAs maternally expressed gene 3 (Meg3) prevents cellular senescence of hepatic vascular endothelium and obesity-induced insulin resistance, we decided to examine its role in cellular senescence and atherosclerosis. METHODS AND RESULTS: By analyzing our data and human and mouse data from the Gene Expression Omnibus database, we found that Meg3 expression was reduced in humans and mice with cardiovascular disease, indicating its potential role in atherosclerosis. In Ldlr-/- mice fed a Western diet for 12 weeks, Meg3 silencing by chemically modified antisense oligonucleotides attenuated the formation of atherosclerotic lesions by 34.9% and 20.1% in male and female mice, respectively, revealed by en-face Oil Red O staining, which did not correlate with changes in plasma lipid profiles. Real-time quantitative PCR analysis of cellular senescence markers p21 and p16 revealed that Meg3 deficiency aggravates hepatic cellular senescence but not cellular senescence at aortic roots. Human Meg3 transgenic mice were generated to examine the role of Meg3 gain-of-function in the development of atherosclerosis induced by PCSK9 overexpression. Meg3 overexpression promotes atherosclerotic lesion formation by 29.2% in Meg3 knock-in mice independent of its effects on lipid profiles. Meg3 overexpression inhibits hepatic cellular senescence, while it promotes aortic cellular senescence likely by impairing mitochondrial function and delaying cell cycle progression. CONCLUSIONS: Our data demonstrate that Meg3 promotes the formation of atherosclerotic lesions independent of its effects on plasma lipid profiles. In addition, Meg3 regulates cellular senescence in a tissue-specific manner during atherosclerosis. Thus, we demonstrated that Meg3 has multifaceted roles in cellular senescence and atherosclerosis.

Sleep disorders and cardiovascular risk: Focusing on sleep fragmentation.

In this comment, we explored the link between sleep fragmentation and the cardiovascular risk, considering various sleep disorders and methodologies for assessing sleep fragmentation.

Friction injury of the central vein caused by catheter for hemodialysis: an in vitro study.

Vascular injury such as central venous stenosis (CVS) is a common complication in hemodialysis patients with central venous catheters (CVCs), yet the impact of the microstructure and partial physic characteristics of catheter surface on the chronic injury of central vein has not been elucidated. In this study, the microscopic morphology of tips and bodies of six different brands of polyurethane CVCs was observed and their roughness was assessed. Subsequently, an in vitro model was established to measure the coefficients of friction (COF) between CVCs (tips and bodies) and the vena cava intima of Japanese rabbits under the same condition in a linear reciprocating mode, and changes in the intima of vessels after friction were observed. The study found that there was a significant variation in surface roughness among different brands of CVCs (tips P < 0.001, bodies P = 0.02), and the COF was positively correlated with the catheter surface roughness (tips P = 0.005, R = 0.945, bodies P = 0.01, R = 0.909). Besides, the endovascular roughness increased after friction. These findings suggest that the high roughness surface of CVCs may cause chronic mechanical friction injury to the central venous intima, which is one of the potential factors leading to CVS or occlusion. This provides a breakthrough for reducing complications, improving patient prognosis, and advancing catheter surface lubrication technology.

Zinc-Dependent Histone Deacetylases in Lung Endothelial Pathobiology.

A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and, as such, provides a semi-selective barrier between the blood and the interstitial space. Compromise of the lung EC barrier due to inflammatory or toxic events may result in pulmonary edema, which is a cardinal feature of acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS). The EC functions are controlled, at least in part, via epigenetic mechanisms mediated by histone deacetylases (HDACs). Zinc-dependent HDACs represent the largest group of HDACs and are activated by Zn2+. Members of this HDAC group are involved in epigenetic regulation primarily by modifying the structure of chromatin upon removal of acetyl groups from histones. In addition, they can deacetylate many non-histone histone proteins, including those located in extranuclear compartments. Recently, the therapeutic potential of inhibiting zinc-dependent HDACs for EC barrier preservation has gained momentum. However, the role of specific HDAC subtypes in EC barrier regulation remains largely unknown. This review aims to provide an update on the role of zinc-dependent HDACs in endothelial dysfunction and its related diseases. We will broadly focus on biological contributions, signaling pathways and transcriptional roles of HDACs in endothelial pathobiology associated mainly with lung diseases, and we will discuss the potential of their inhibitors for lung injury prevention.

Unveiling HPV's hidden link: Cardiovascular diseases and the viral intrigue.

Cardiovascular diseases (CVD) remain a major global health challenge, with an escalating impact on mortality despite advancements in managing conventional risk factors. This review investigates the intricate relationship between human papillomavirus (HPV) and CVD, shedding light on a novel aspect of cardiovascular health. Despite significant progress in understanding and managing traditional CVD risk factors, a substantial proportion of CVD cases lack these conventional markers. Recent research has unveiled HPV, a prevalent sexually transmitted infection, as a potential unconventional risk factor for CVD. This review delves into the underlying mechanisms linking HPV to CVD pathogenesis. HPV's influence on vascular endothelium and induction of systemic inflammation are key contributors. Additionally, HPV disrupts host lipid metabolism, further exacerbating the development of atherosclerosis. The link between HPV and CAD is not merely correlative; it encompasses a complex interplay of virological, immunological, and metabolic factors. Understanding the connection between HPV and CVD holds transformative potential. Insights from this review not only underscore the significance of considering HPV as a crucial risk factor but also advocate for targeted HPV screening and vaccination strategies to mitigate CVD risks. This multidisciplinary exploration bridges the gap between infectious diseases and cardiovascular health, emphasizing the need for a comprehensive approach to combating the global burden of cardiovascular disease. Further research and clinical guidelines in this realm are essential to harness the full scope of preventive and therapeutic interventions, ultimately shaping a healthier cardiovascular landscape.

Shear Stress and the AMP-Activated Protein Kinase Independently Protect the Vascular Endothelium from Palmitate Lipotoxicity.

Saturated free fatty acids are thought to play a critical role in metabolic disorders associated with obesity, insulin resistance, type 2 diabetes (T2D), and their vascular complications via effects on the vascular endothelium. The most abundant saturated free fatty acid, palmitate, exerts lipotoxic effects on the vascular endothelium, eventually leading to cell death. Shear stress activates the endothelial AMP-activated protein kinase (AMPK), a cellular energy sensor, and protects endothelial cells from lipotoxicity, however their relationship is uncertain. Here, we used isoform-specific shRNA-mediated silencing of AMPK to explore its involvement in the long-term protection of macrovascular human umbilical vein endothelial cells (HUVECs) against palmitate lipotoxicity and to relate it to the effects of shear stress. We demonstrated that it is the α1 catalytic subunit of AMPK that is critical for HUVEC protection under static conditions, whereas AMPK-α2 autocompensated a substantial loss of AMPK-α1, but failed to protect the cells from palmitate. Shear stress equally protected the wild type HUVECs and those lacking either α1, or α2, or both AMPK-α isoforms; however, the protective effect of AMPK reappeared after returning to static conditions. Moreover, in human adipose microvascular endothelial cells isolated from obese diabetic individuals, shear stress was a strong protector from palmitate lipotoxicity, thus highlighting the importance of circulation that is often obstructed in obesity/T2D. Altogether, these results indicate that AMPK is important for vascular endothelial cell protection against lipotoxicity in the static environment, however it may be dispensable for persistent and more effective protection exerted by shear stress.

The Role of the Receptor Activator of Nuclear Factor Kappa-B Ligand/Osteoprotegerin Ratio in Vascular Diseases: A Therapeutic Approach.

Cardiovascular and bone diseases contribute independently to mortality and global health. The exact mechanisms involved in the pathophysiology shared between bone and vascular diseases are not well defined. Endothelial cells and osteoblasts communicate during osteogenesis, thus establishing a connection between angiogenesis and osteogenesis. One shared mechanism may involve osteoprotegerin (OPG) and its ligand Receptor Activator of NF-κB Ligand (RANKL). The RANKL/OPG ratio is an important modulator for the skeletal, immunological, and vascular systems. OPG levels are elevated due to either osteogenic causes or inflammatory responses in the vasculature. The data obtained from clinical and in vitro studies support the role of the RANKL/OPG ratio as a potential marker for the progression of endothelial damage. Therefore, determining the therapeutic approaches for the targeting RANKL/OPG ratio and evaluating its usage as a biomarker in cardiovascular and bone pathophysiology are needed. By integrating the protective and disease-causing role of OPG with its ligand, this review outlines the role of the RANKL/OPG ratio at the molecular level. We also consider targeted therapeutic approaches.

Macro- and microscopic changes in veins with short-term central venous catheters: an observational autopsy study.

BACKGROUND: Centrally inserted central catheters (CICCs) are indispensable in modern healthcare, but unfortunately, come with complications. Catheter-related thrombosis is a well-known complication reported to occur in 5-30% of patients with CICC. There is a paucity of studies that report the incidence of catheter-related thrombosis after the introduction of real-time ultrasound insertion guidance as clinical practice. This study aimed to demonstrate any pathological macro- or microscopic changes in the vein wall associated with CICCs. METHODS: The study was approved by the Swedish Ethical Review Authority and was conducted at a large university hospital. The study included 12 patients with a short-term CICC who were subject to autopsies. Vessels with inserted catheters were macroscopically and microscopically examined. RESULTS: In total, seven female and five male patients with a median age of 70 (interquartile range 63-76) were included. With one exception, all patients received routine thromboprophylaxis throughout the period with CICC. Most inserted CICCs were 9.5 French (54%) and were inserted in the internal jugular vein (92%). The median time with CICC was seven days (interquartile range 1.8-20). At autopsy, thrombi were observed in all cases (100%), macroscopically and microscopically, attached to the distal portion of the CICC and/or the adjacent vessel wall. Inflammatory changes in the vessel walls were seen in all cases, and varying degrees of fibrosis were demonstrated in eight cases (67%). CONCLUSIONS: This autopsy study demonstrated that catheter-related thrombus formation with adjacent inflammatory and fibrotic vessel wall thickening was very common, despite a limited period of catheter use. The consequences of these findings are important, as thrombi may cause pulmonary embolism and possibly lead to catheter-related infections, and since inflammatory and fibrotic vessel wall thickening may evolve into chronic venous stenosis. Furthermore, the findings are a cause of concern, as CICCs are indispensable in modern healthcare and complications may be masked by the general disease that was the indication for CICC insertion.

COVID-19-related posterior reversible encephalopathy syndrome: insights from a clinical case.

In the present case report, a 50-year-old female presented with hemiparesis and blurred vision and was subsequently diagnosed with posterior reversible encephalopathy syndrome (PRES) associated with coronavirus disease 2019 (COVID-19). Magnetic resonance imaging revealed cortico-subcortical edema with hyperintensities bilaterally in the frontoparietal and bi-occipital regions. Although PRES is a neurotoxic disorder that typically affects white matter of the brain and often is associated with hypertension, renal failure, and autoimmune disorders, recent studies have suggested that COVID-19 increases the risk of PRES. This case report presents a unique instance of COVID-19-related PRES. Unlike most previously reported cases occurring during the acute phase of severe COVID-19, our patient experienced PRES during the recovery phase with mild initial symptoms, such as fatigue and mild fever. The article discusses the pathophysiology of PRES, the potential mechanisms by which COVID-19 leads to PRES, and the treatment and outcome of the patient.

Biomarkers determining treatment interval of diabetic macular edema after initial resolution by anti-vascular endothelial growth factor.

PURPOSE: To identify predictive factors that help determine the interval of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection after the initial resolution of diabetic macular edema (DME). METHODS: This retrospective case-control study enrolled treatment-naïve DME patients who had achieved DME resolution after intravitreal anti-VEGF injections. Patients were classified into the recurrence and no-recurrence groups, depending on the development of recurrent DME after deferring intravitreal anti-VEGF injection. The demographics and clinical features, including optical coherence tomography findings, were compared between the two groups. RESULTS: We enrolled 105 eyes. Sixty eyes (57.1%) belonged to the no-recurrence group, and 45 (42.9%), belonged to the recurrence group. The severity of diabetic retinopathy at baseline was related to early DME recurrence (P = 0.009). At the treatment deferring point, the non-recurrence group had both thinner central subfield thickness (289.5 ± 27.2 µm vs. 307.0 ± 38.2 µm, P = 0.011) and thinner central retinal thickness (214.9 ± 41.4 µm vs. 231.8 ± 41.2 µm, P = 0.043) compared to the recurrence group. Intraretinal cyst was observed in 34 eyes (56.7%) in the no-recurrence group and 42 eyes (93.3%) in the recurrence group at the deferring point (P < 0.001). CONCLUSION: A low risk of early DME recurrence is anticipated in the eyes with foveal thinning and no intraretinal cyst when anti-VEGF injection is deferred. These predictive biomarkers can be useful for patient monitoring and determining treatment strategies for DME patients.

Evaluación de la disfunción del endotelio para el pronóstico de riesgo cardiovascular / Evaluation of endothelial dysfunction for cardiovascular risk prediction i: en

Introducción: Las enfermedades cardiovasculares constituyen la primera causa de muerte en el mundo, por lo que la identificación y modificación de los factores de riesgo asociados a ellas constituyen estrategias priorizadas por la Organización Mundial de la Salud. Contar con un modelo de predicción del riesgo cardiovascular enriquecido con la evaluación de la disfunción endotelial influiría positivamente en estas metas. Objetivos: Identificar la presencia de disfunción endotelial en pacientes con enfermedades cardiovasculares o sin estas y determinar la asociación entre ambas. Métodos: Se realizó un estudio observacional y descriptivo, de serie de casos, en el Centro de Cardiología y Cirugía Cardiovascular del Hospital Provincial Docente Clínico-Quirúrgico Saturnino Lora de Santiago de Cuba, desde enero del 2022 hasta igual mes del 2023, donde se analizaron como variables los factores de riesgo cardiovascular tradicionales y los biomarcadores de disfunción endotelial. Secundariamente, se llevó a cabo un estudio analítico de casos y controles en el cual se aplicó la regresión logística binaria multivariada. Resultados: Se confirmó la presencia de disfunción endotelial asociada a la aparición de las enfermedades cardiovasculares, lo que se evaluó a través del índice de vasodilatación, mediado por el flujo de la arteria braquial y las concentraciones plasmáticas de fibrinógeno. Conclusiones: Las características epidemiológicas y clínicas de los pacientes con enfermedades cardiovasculares o sin estas no difirieron de lo registrado en la literatura especializada acerca de la base de identificación de los factores de riesgo tradicionales.

Introduction: Cardiovascular diseases constitute the first death cause worldwide, reason why the identification and modification of associated risk factors constitute prioritized strategies by the World Health Organization. To have a prediction model of cardiovascular risk enriched with the evaluation of the endothelial dysfunction would influence positively in these goals. Objectives: To identify the presence of endothelial dysfunction in patients with or without cardiovascular diseases and to determine the association between them. Methods: An observational and descriptive cases series study was carried out in the Cardiology and Cardiovascular Surgery Center at Saturnino Lora Teaching Clinical Surgical Provincial Hospital in Santiago de Cuba, from January, 2022 to the same month, 2023, where the traditional cardiovascular risk factors and endothelial dysfunction biomarkers were analyzed as variables. Secondarily, an analytic case-control study was carried out in which multivariate binary logistic regression was applied. Results: The presence of endothelial dysfunction associated with the onset of cardiovascular diseases was confirmed, what was evaluated through the vasodilatation index, mediated by the brachial artery flow and the fibrinogen plasmatic concentrations. Conclusions: The clinical and epidemiological pattern of patients with or without cardiovascular diseases did not differ from that reported in the specialized literature on the base of the identification of traditional risk factors.

Sodium Selenite Ameliorates Silver Nanoparticles Induced Vascular Endothelial Cytotoxic Injury by Antioxidative Properties and Suppressing Inflammation Through Activating the Nrf2 Signaling Pathway.

Silver nanoparticles (AgNP) are the dominant nanomaterials in commercial products and the medical field, but the widespread occurrence of AgNP has become a global threat to human health. Growing studies indicate that AgNP exposure can induce vascular endothelial toxicity by excessive oxidative stress and inflammation, which is closely related to cardiovascular disease (CVD), but the potential intrinsic mechanism remains poorly elucidated. Thus, it has been crucial to control the toxicological effects of AgNP in order to improve their safety and increase the outcome of their applications.Multiple researches have demonstrated that sodium selenite (Se) possesses the capability to counteract the toxicity of AgNP, but the functional role of Se in AgNP-induced CVD is largely unexplored. The aim of this study was to explore the potential protective effect of Se on AgNP-induced vascular endothelial lesion and elucidate the underlying mechanisms. An in vivo model of toxicity in animals was established by the instillation of 200 µL of AgNP into the trachea of rats both with (0.2 mg/kg/day) and without Se treated. In vitro experiments, human umbilical vein endothelial cells (HUVECs) were incubated with AgNP (0.3 µg/mL ) and Se for a duration of 24 h. Utilizing transmission electron microscopy, we observed that the internalization of AgNP-induced endothelial cells was desquamated from the internal elastic lamina, the endoplasmic reticulum was dilated, and the medullary vesicle formed. Se treatment reduced the levels of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), inhibited the release of pro-inflammatory cytokines (specifically tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6), improved endothelial cell permeability, integrity, and dysfunction, and prevented damage to the aortic endothelium caused by AgNP. Importantly, we found that Se showed the capacity against AgNP with biological functions in guiding the intracellular reactive oxygen species (ROS) scavenging and meanwhile exhibiting anti-inflammation effects. Se supplementation decreased the intracellular ROS release and suppressed NOD-like receptor protein 3 (NLRP3) and nuclear factor kappa-B (NF-κB) mediated inflammation within AgNP-intoxicated rats and HUVECs. The anti-oxidant stress and anti-inflammatory effects of Se were at least partly dependent on nuclear factor erythroid 2-related factor 2 (Nrf2). Overall, our results indicated that the protectiveness of Se against AgNP-induced vascular endothelial toxicity injury was at least attributed to the inhibition of oxidative ROS and pro-inflammatory NF-κB/NLRP3 inflammasome by activating the Nrf2 and antioxidant enzyme (HO-1) signal pathway.

Nuciferine induces autophagy to relieve vascular cell adhesion molecule 1 activation via repressing the Akt/mTOR/AP1 signal pathway in the vascular endothelium.

Pro-inflammatory factor-associated vascular cell adhesion molecule 1 (VCAM1) activation initiates cardiovascular events. This study aimed to explore the protective role of nuciferine on TNFα-induced VCAM1 activation. Nuciferine was administrated to both high-fat diet (HFD)-fed mice and the TNFα-exposed human vascular endothelial cell line. VCAM1 expression and further potential mechanism(s) were explored. Our data revealed that nuciferine intervention alleviated VCAM1 activation in response to both high-fat diet and TNFα exposure, and this protective effect was closely associated with autophagy activation since inhibiting autophagy by either genetic or pharmaceutical approaches blocked the beneficial role of nuciferine. Mechanistical studies revealed that Akt/mTOR inhibition, rather than AMPK, SIRT1, and p38 signal pathways, contributed to nuciferine-activated autophagy, which further ameliorated TNFα-induced VCAM1 via repressing AP1 activation, independent of transcriptional regulation by IRF1, p65, SP1, and GATA6. Collectively, our data uncovered a novel biological function for nuciferine in protecting VCAM1 activation, implying its potential application in improving cardiovascular events.

Understanding yellow fever-associated myocardial injury: an autopsy study.

BACKGROUND: Yellow fever (YF) is a viral hemorrhagic fever, endemic in parts of South America and Africa. There is scarce evidence about the pathogenesis of the myocardial injury. The objective of this study is to evaluate the cardiac pathology in fatal cases of YF. METHODS: This retrospective autopsy study included cases from the São Paulo (Brazil) epidemic of 2017-2019. We reviewed medical records and performed cardiac tissue histopathological evaluation, electron microscopy, immunohistochemical assays, RT-qPCR for YF virus (YFV)-RNA, and proteomics analysis on inflammatory and endothelial biomarkers. FINDINGS: Seventy-three confirmed YF cases with a median age of 48 (34-60) years were included. We observed myocardial fibrosis in 68 (93.2%) patients; cardiomyocyte hypertrophy in 68 (93.2%); endothelial alterations in 67 (91.8%); fiber necrosis in 50 (68.5%); viral myocarditis in 9 (12.3%); and secondary myocarditis in 5 (6.8%). Four out of five patients with 17DD vaccine-associated viscerotropic disease presented with myocarditis. The cardiac conduction system showed edema, hemorrhages and endothelial fibrinoid necrosis. Immunohistochemistry detected CD68-positive inflammatory interstitial cells and YFV antigens in endothelial and inflammatory cells. YFV-RNA was detected positive in 95.7% of the cardiac samples. The proteomics analysis demonstrated that YF patients had higher levels of multiple inflammatory and endothelial biomarkers in comparison to cardiovascular controls, and higher levels of interferon gamma-induced protein 10 (IP-10) in comparison to sepsis (p = 0.01) and cardiovascular controls (p < 0.001) in Dunn test. INTERPRETATION: Myocardial injury is frequent in severe YF, due to multifactorial mechanisms, including direct YFV-mediated damage, endothelial cell injury, and inflammatory response, with a possible prominent role for IP-10. FUNDING: This study was funded by Fundação de Amparo à Pesquisa do Estado de São Paulo, Bill and Melinda Gates Foundation, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.

Comparative analysis of co-culture and monoculture models in simulating diabetic neurovascular dysfunction: insights into diabetic retinopathy.

Background: Interaction between retinal vascular endothelial cells and neurons plays a critical role in the pathogenesis of diabetic retinopathy (DR). This study aims to compare an in vitro model over a monoculture model to simulate the neurovascular coupling under the hyperglycemic microenvironment of diabetes. Methods: Rat retinal vascular endothelial cells (RRMECs) and ganglion cells (RGCs) were seeded mono- or co-cultured in a normal (NG, 5.5 mM) and high (HG, 75 mM) glucose concentrations culture medium. Cell viability was detected by the cell counting kit-8 (CCK-8) assay. The ability of migration and lumen formation of RRMECs were determined by scratch wound, transwell migration, and lumen formation assays. The apoptosis index of cells was calculated and detected by propidium iodide (PI)/Hoechst staining. Quantitative and morphological analysis of RGCs was performed through the labeling of RGCs by brain-specific homeobox/POU domain protein 3A (BRN3A) and anti-beta-III tubulin (TUJ1). The gene and protein expression levels of occludin (OCLN) and zonula occludens-1 (ZO-1) were evaluated by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Results: The viability, migration, and lumen formation abilities of RRMECs in the HG group significantly increased (P<0.05) in both mono- and co-culture models. Migration and lumen formation abilities of RRMECs in the co-culture with HG were lower than that in the monoculture group (P<0.05). The viability of RGCs cells with HG significantly decreased in both mono- and co-culture models (Pmono<0.001, Pco<0.001), the apoptosis index of RGCs in the co-culture with HG was higher than that in the monoculture (P=0.010). The protein and gene expression of OCLN, and ZO-1 in RRMECs significantly decreased with HG culture medium in both culture models (P<0.05). In the HG group, the protein and gene expression level of the ZO-1 and OCLN of RRMECs significantly decreased in the co-culture model than that in the monoculture model (P<0.05). Conclusion: Compared with mono cell culture, the established co-culture in vitro system for diabetic neurovascular dysfunction can better stimulate the micro-environment of the retinal neurovascular unit.

Abnormal generation of IL-17A represses tumor infiltration of stem-like exhausted CD8+ T cells to demote the antitumor immunity.

BACKGROUND: Variated anti-cancer therapies are combined with immune checkpoint blockades (ICBs) for improving ICB therapeutic efficacy. Occurrence of tissue damage is common that triggers multiple inflammatory cytokine generation. Gastrointestinal organs are the commonly affected. We investigated the impact of acute colitis on tumor infiltration of antigen-specific CD8+ cytotoxic T lymphocytes (CTLs) for controlling tumor growth and responding to antibody against PD-1 (anti-PD-1). METHODS: Several tumor cell lines were inoculated into syngeneic mice subcutaneously or intra-hepatically. When tumor mass formed, activated CTLs were intravenously transferred into the tumor-bearing mice, that were given the drinking water containing 2% dextran sulfate sodium (DSS) for acute colitis induction. Tumor growth, infiltration of two exhausted CTL subsets, and the CTL interaction with tumor vascular endothelium were examined. RESULTS: Acute colitis dampened CTL-mediated antitumor effects, correlating with IL-17A elevation in the inflamed intestine. In the tumor bed, stem-like exhausted CTLs, which were defined as PD-1+Slamf6+Tim3-, expressed higher IL-17A receptor heterodimers and lower leukocyte function-associated antigen-1 (LFA-1) than terminally exhausted CTLs did, that were defined as PD-1+Slamf6-Tim3+. IL-17A stimulation reduced LFA-1 surface expression on stem-like exhausted CTLs and the counterpart ICAM-1 (intracellular adhesion molecule-1) on tumor vascular endothelium. IL-17A stimulation suppressed the extravasation across tumor vascular endothelium and self-renewal of stem-like, not the terminally exhausted CTLs. Administration of anti-IL-17A neutralizing antibody to the colitis mice restored the CTL tumor infiltration and enhanced anti-PD-1 treatment efficacy against tumors. In 33 hepatocellular carcinoma patients being treated with anti-PD-1 plus antibody against vascular endothelial growth factor, disease progression of 15 patients, that exhibited serum IL-17A increase 24 h post-therapy as compared to pre-therapy level, was poorer than that of 18 patients that exhibited serum IL-17A no-increase. CONCLUSIONS: Abnormal generation of IL-17A mainly repressed tumor infiltration of stem-like exhausted CTLs. ICB-based immunotherapeutic efficacy could be upgraded with administration of anti-IL-17A, when treatment-related IL-17A elevation occurred due to tissue damage, such as acute colitis.

Bone marrow-derived mononuclear cells ameliorate neurological function in chronic cerebral infarction model mice via improvement of cerebral blood flow.

BACKGROUND AIMS: Stroke is a frequently observed neurological disorder that might lead to permanent and severe disability. Recently, various regenerative therapies have been developed, some of which have already been applied clinically. However, their outcomes have not been fully satisfactory. In particular, the development of regenerative therapies for chronic ischemic stroke is greatly needed. Herein intracerebral administration of bone marrow-derived mononuclear cells (BM-MNCs) was assessed as a potential treatment for chronic ischemic stroke using a severe combined immunodeficiency mouse model characterized by minimal vascular variation unrelated to immunodeficiency. METHODS: A reproducible model of permanent middle cerebral artery occlusion was prepared, and intracerebral BM-MNC transplantation was performed 14 days after stroke induction in the infarcted brain. RESULTS: Sensorimotor behavioral function and cerebral blood flow were significantly improved upon treatment with BM-MNCs compared to control medium injection. The transplanted cells exhibited characteristics of the vascular endothelium and microglia/macrophages. Significant angiogenesis and suppression of astrogliosis and microgliosis were observed in the affected brain. Messenger RNA expression analysis showed significant increases in anti-inflammatory cytokines, A2 astrocyte/anti-inflammatory microglia markers and vascular endothelial markers such as vascular endothelial growth factor and significant decreases in pro-inflammatory cytokines and A1 astrocyte/pro-inflammatory microglia markers following BM-MNC transplantation. CONCLUSIONS: These results suggest that intracerebral administration of BM-MNCs should be considered an effective cell therapy for chronic stroke.

Alkaloids as Vasodilator Agents: A Review.

The pathophysiology of hypertension is often associated with endothelial dysfunction and the impairment of endothelium-dependent vasodilation mechanisms, as well as alterations in vascular smooth muscle (VSM) tone. Natural products, particularly alkaloids, have received increased attention in the search for new vasodilator agents. This review aims to summarize the noteworthy results from ex-vivo and in-vitro studies that explored the vasodilatory effects of some selected alkaloids (Berberine, Sinomenine, (S)-Reticuline, Neferine, Nuciferine, Villocarine A, 8-Oxo-9-Dihydromakonakine, Harmaline, Harman, and Capsaicin) and the underlying mechanisms implicated. The results obtained from the literature revealed that these selected alkaloids exhibited vasodilation in various vascular models, including mesenteric, carotid, and coronary arteries, thoracic aorta, and cultured HUCECs and VSMCs. Furthermore, most of these alkaloids induced vasodilation through endothelium- dependent and endothelium-independent mechanisms, which were primarily mediated by activating eNOS/NO/sGC/cGMP pathway, opening various potassium (K+) channels, or modulating calcium (Ca2+) channels. Additionally, several alkaloids exerted vasodilatory effects through multiple mechanism pathways. Moreover, different alkaloids demonstrated the ability to protect endothelial function by reducing oxidative stress, endoplasmic reticulum and inflammation. In conclusion, this class of secondary metabolites holds interesting therapeutic potential in the prevention and treatment of cardiovascular diseases (CVD), particularly hypertension.