Vascular Inflammatory Diseases Research Articles

TNF-α elicits phenotypic and functional alterations of vascular smooth muscle cells by miR-155-5p–dependent down-regulation of cGMP-dependent kinase 1

cGMP-dependent protein kinase 1 (PKG1) plays an important role in nitric oxide (NO)/cGMP-mediated maintenance of vascular smooth muscle cell (VSMC) phenotype and vasorelaxation. Inflammatory cytokines, including tumor necrosis factor-α (TNFα), have long been understood to mediate several inflammatory vascular diseases. However, the underlying mechanism of TNFα-dependent inflammatory vascular disease is unclear. Here, we found that TNFα treatment decreased PKG1 expression in cultured VSMCs, which correlated with NF-κB-dependent biogenesis of miR-155-5p that targeted the 3'-UTR of PKG1 mRNA. TNFα induced VSMC phenotypic switching from a contractile to a synthetic state through the down-regulation of VSMC marker genes, suppression of actin polymerization, alteration of cell morphology, and elevation of cell proliferation and migration. All of these events were blocked by treatment with an inhibitor of miR-155-5p or PKG1, whereas transfection with miR-155-5p mimic or PKG1 siRNA promoted phenotypic modulation, similar to the response to TNFα. In addition, TNFα-induced miR-155-5p inhibited the vasorelaxant response of de-endothelialized mouse aortic vessels to 8-Br-cGMP by suppressing phosphorylation of myosin phosphatase and myosin light chain, both of which are downstream signal modulators of PKG1. Moreover, TNFα-induced VSMC phenotypic alteration and vasodilatory dysfunction were blocked by NF-κB inhibition. These results suggest that TNFα impairs NO/cGMP-mediated maintenance of the VSMC contractile phenotype and vascular relaxation by down-regulating PKG1 through NF-κB-dependent biogenesis of miR-155-5p. Thus, the NF-κB/miR-155-5p/PKG1 axis may be crucial in the pathogenesis of inflammatory vascular diseases, such as atherosclerotic intimal hyperplasia and preeclamptic hypertension.

Pharmacological inhibition of MALT1 protease activity suppresses endothelial activation via enhancing MCPIP1 expression

Mucosa associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is not only an intracellular signaling scaffold protein but also a paracaspase that plays a key role in the signal transduction and cellular activation of lymphocytes and macrophages. However, its role in endothelial cells remains unknown. Here we report that pharmacological inhibition of MALT1 protease activity strongly suppresses endothelial activation via enhancing MCPIP1 expression. Treatment with MALT1 protease inhibitors selectively inhibited TNFα-induced VCAM-1 expression in HUVECs and LPS-induced VCAM-1 expression in mice. In addition, Inhibition of MALT1 protease activity also significantly inhibited TNFα-induced adhesion of THP-1 monocytic cells to HUVECs. To explore the mechanisms, MALT1 inhibitors does not affect the activation of NF-κB signaling pathway in HUVEC. However, they can stabilize MCPIP1 protein and significantly enhance MCPIP1 protein level in endothelial cells. These results suggest that MALT1 paracaspase also targets MCPIP1 and degrade MCPIP1 protein in endothelial cells similar as it does in immune cells. Taken together, the study suggest inhibition of MALT1 protease activity may represent a new strategy for prevention/therapy of vascular inflammatory diseases such as atherosclerosis.

Interferon-γ induces biphasic changes in caldesmon localization as well as adherens junction organization and expression in HUVECs

Endothelial barrier dysfunction leads to increased endothelial permeability and is an early step in the development of vascular inflammatory diseases such as atherosclerosis. Interferon-γ (IFN-γ), a proinflammatory cytokine, is known to cause increased endothelial permeability. However, the mechanisms by which IFN-γ disrupts the endothelial barrier have not been clarified. This study aimed to investigate how IFN-γ impairs the endothelial barrier integrity by specifically examining the roles of caldesmon, adherens junctions (AJs) and p38 mitogen-activated protein (MAP) kinase in IFN-γ-induced endothelial barrier dysfunction. IFN-γ exhibited a biphasic effect on caldesmon localization and both the structural organization and protein expression of AJs. In the early phase (4-8 h), IFN-γ induced the formation of peripheral caldesmon bands and discontinuous AJs, while AJ protein expression was unchanged. Interestingly, IFN-γ also stimulated caldesmon phosphorylation, resulting in actin dissociation from caldesmon at 8 h. Conversely, changes seen in the late phase (16–24 h) included cytoplasmic caldesmon dispersal, AJ linearization and junctional area reduction, which were associated with reduced membrane, cytoskeletal and total AJ protein expression. In addition, IFN-γ enhanced myosin binding to caldesmon at 12 h and persisted up to 24 h. Furthermore, inhibition of p38 MAP kinase by SB203580 did not reverse either the early or late phase changes observed. These data suggest that IFN-γ may activate signaling molecules other than p38 MAP kinase. In conclusion, our findings enhance the current understanding of how IFN-γ disrupts endothelial barrier function and reveal potential therapeutic targets, such as caldesmon and AJs, for the treatment of IFN-γ-associated vascular inflammatory diseases.

Role of dihydroartemisinin in regulating prostaglandin E2 synthesis cascade and inflammation in endothelial cells.

Endothelial cells (ECs) are crucial in maintaining vascular homeostasis. Endothelial dysfunction was involved in many cardiovascular diseases (CVDs). Recently, antimalarial medicine artemisinin and its derivatives including dihydroartemisinin (DHA) were found to be beneficial in some diseases including CVDs. Prostaglandin (PG) E2 is a known inflammatory mediator and plays important roles in cardiovascular system. This study was to investigate the role of DHA in regulating cyclooxygenase (COX)/PGE synthase (PGES)/PGE2 cascade and inflammation in ECs. After DHA treatment, the mRNA and protein levels of COX-2 were strikingly upregulated in time- and dose-dependent manners. In contrast, COX-1 was significantly downregulated. As expected, inhibition of COX-1 or COX-2 further reduced PGE2 production after DHA treatment. Moreover, DHA enhanced microsomal PGE2 synthase (mPGES)-2 and moderately modulated cytosolic PGE2 synthase (cPGES) with no effect on mPGES-1 expression. Importantly, DHA significantly reduced PGE2 levels in line with the upregulation of 15-hydroxyprostaglandin dehydrogenase (15-PGDH, a key enzyme for prostaglandin degradation). Lastly, we observed that DHA not only reduced the PGE2 levels in tumor necrosis factor-α (TNF-α)-treated ECs but also blunted the upregulation of inflammatory cytokines of interleukin (IL)-6 and IL-1β induced by TNF-α or PGE2. These findings demonstrated an important role of DHA in regulating PGE2 synthesis cascade and inflammation in ECs, suggesting a potential of DHA for the treatment of inflammatory vascular diseases.

Isolation, Synthesis, and Antisepsis Effects of a C-Methylcoumarinochromone Isolated from Abronia nana Cell Culture.

Only a few isoflavones have been isolated from plants of the genus Abronia. The biological properties of compounds isolated from Abronia species have not been well established, and their antisepsis effects have not been reported yet. In the present study, a new C-methylcoumarinochromone, was isolated from Abronia nana suspension cultures. Its structure was deduced as 9,11-dihydroxy-10-methylcoumarinochromone (boeravinone Y, 1) by spectroscopic data analysis and verified by chemical synthesis. The potential inhibitory effects of 1 against high mobility group box 1 (HMGB1)-mediated septic responses were investigated. Results showed that 1 effectively inhibited lipopolysaccharide-induced release of HMGB1 and suppressed HMGB1-mediated septic responses, in terms of reduction of hyperpermeability, leukocyte adhesion and migration, and cell adhesion molecule expression. In addition, 1 increased the phagocytic activity of macrophages and exhibited bacterial clearance effects in the peritoneal fluid and blood of mice with cecal ligation and puncture-induced sepsis. Collectively, these results suggested that 1 might have potential therapeutic activity against various severe vascular inflammatory diseases via inhibition of the HMGB1 signaling pathway.

Abstract 654: Isoleukotoxin Promotes Autophagy and Reduces Vascular Cell Adhesion Molecule-1 Expression in Endothelial Cells

Rapamycin is a widely used autophagy inducer and has been shown to suppress development of atherosclerosis in animal models. However, the side effect is severe including hyperlipidemia. We identified isoleukotoxin, a metabolite of linoleic acid, as an autophagy inducer and hypothesized that it can be used to reduce inflammation of endothelial cells. To test this hypothesis we treated human umbilical vein endothelial cells (HUVECs) with tumor necrosis factor α (TNFα) along with isoleukotoxin. Rapamycin was used as a positive control to induce autophagy. Isoleukotoxin promotes autophagic flux in HUVECs as well as rapamycin. Isoleukotoxin does not inhibit activity of mammalian target of rapamycin complex, while it inhibits activity of the downstream kinase, S6K. Isoleukotoxin modulates TNFα-induced cell adhesion molecules expression in HUVECs with a similar pattern as rapamycin. In this pattern, only vascular cell adhesion molecule-1 (VCAM-1) expression is reduced but not intercellular cell adhesion molecule-1 (ICAM-1). More interestingly, time-course analysis shows that VCAM-1 expression is only reduced after 20 hours treatment, which is different from that of inhibitors of VCAM-1 transcription such as SB202190. By qPCR we confirmed that isoleukotoxin does not inhibit VCAM-1 transcription. To determine whether isoleukotoxin reduces VCAM-1 expression by inhibiting S6K-mediated protein translation, we compared the effect of isoleukotoxin with S6K siRNA. S6K siRNA reduces expression of VCAM-1 slightly and also ICAM-1, which is different from that of isoleukotoxin. After excluding the regulation of transcription and translation, we hypothesize that isoleukotoxin reduces VCAM-1 expression by promoting VCAM-1 degradation via autophagy. This hypothesis is supported by blocking of autophagy and endocytosis. Blocking of autophagy by Atg5 siRNA enhances VCAM-1 expression, suggesting that VCAM-1 may be degraded by autophagy. Blocking of endocytosis by dynasore blocks the effect of isoleukotoxin on VCAM-1 expression, suggesting that VCAM-1 is degraded after endocytosis. Here we propose that isoleukotoxin is an anti-inflammation and a potential therapeutic molecule for inflammatory vascular diseases such as atherosclerosis.

Effects of indomethacin on erythrocyte nitric oxide metabolism and erythrocyte deformability

Increased erythrocyte filtration index (decreased erythrocyte deformability; ED) was observed in patients with Behcet disease. When patients with Behcet took indomethacin, decreased values of erythrocyte acetylcholinesterase enzyme activity were obtained. An inverse association between nitric oxide (NO) efflux from erythrocytes and ED values was verified in blood samples of patients with vascular inflammatory diseases. The aim of this in vitro study was to verify the effect of indomethacin on ED, NO efflux, nitrite nitrate, peroxynitrite and nitroso- glutathione (GSNO) in the presence of protein tyrosine kinase (PTK Syk), protein tyrosine phosphatase (PTP), adenylyl cyclase (AC) and phosphatidylinositol 3 kinase (PI3K) enzyme inhibitors respectively Syk inhibitor, calpeptin, MDL and wortmannin (WORT). Blood samples from ten healthy donors were divided and aliquots were performed in absence (control aliquot) and presence of indomethacin or indomethacin plus each one of the inhibitors. Further ED and NO efflux and its metabolites were evaluated by the usual methodology. A significant increase in ED values was noted in the presence of indomethacin plus WORT. No significant differences where verified in NO efflux from erythrocytes in all blood aliquots. Significantly increase in GSNO concentration in the presence of indomethacin plus calpeptin, MDL or Wort were observed. Nitrate and peroxynitrite concentrations increased or decreased significantly respectively in all aliquots in relation to the control one. The nitrite levels increased in the aliquots with indomethacin and indomethacin plus MDL, or indomethacin plus Syk. In conclusion indomethacin act as antioxidant decreasing peroxynitrite, not changing NO efflux values and increasing nitrate levels independent of band 3 phosphorylation degree or cyclic adenosine monophosphate (cAMP) concentration. Indomethacin mobilizes nitrite and GSNO in dependant of band 3 phosphorylation degree and cAMP. Indomethacin did not change erythrocyte deformability, unless in combination with wortmannin which increased it.

IL-19 and Other IL-20 Family Member Cytokines in Vascular Inflammatory Diseases.

Cardiovascular disease remains a major medical and socioeconomic burden in developed and developing countries and will increase with an aging and increasingly sedentary society. Many vascular diseases and atherosclerotic vascular disease, in particular, are essentially inflammatory disorders, involving multiple cell types. Communication between these cells is initiated and sustained by a complex network of cytokines and their receptors. The interleukin (IL)-20 family members, IL-19, IL-20, IL-22, and IL-24, initiate, sustain, and drive the progression of vascular disease. They are important in vascular disease as they facilitate a bidirectional cross-talk between resident vascular cells with immune cells. These cytokines are grouped into the same family based on shared common receptor subunits and signaling pathways. This communication is varied and can result in exacerbation, attenuation, and even repair of the vasculature. We will briefly review what is known about IL-20, IL-22, and IL-24 in cardiovascular biology. Because IL-19 is the most studied member of this family in terms of its role in vascular pathophysiological processes, the major emphasis of this review will focus on the expression and atheroprotective roles of IL-19 in vascular inflammatory disease.

Anthocyanin-Rich Extract from Red Chinese Cabbage Alleviates Vascular Inflammation in Endothelial Cells and Apo E−/− Mice

Anthocyanins, the most prevalent flavonoids in red/purple fruits and vegetables, are known to improve immune responses and reduce chronic disease risks. In this study, the anti-inflammatory activities of an anthocyanin-rich extract from red Chinese cabbage (ArCC) were shown based on its inhibitory effects in cultured endothelial cells and hyperlipidemic apolipoprotein E-deficient mice. ArCC treatment suppressed monocyte adhesion to tumor necrosis factor-α-stimulated endothelial cells. This was validated by ArCC’s ability to downregulate the expression and transcription of endothelial adhesion molecules, determined by immunoblot and luciferase promoter assays, respectively. The regulation of adhesion molecules was accompanied by transcriptional inhibition of nuclear factor-κB, which restricted cytoplasmic localization as shown by immunocytochemistry. Administration of ArCC (150 or 300 mg/kg/day) inhibited aortic inflammation in hyperlipidemic apolipoprotein E-deficient mice, as shown by in vivo imaging. Immunohistochemistry and plasma analysis showed that the aortas from these mice exhibited markedly lower leukocyte infiltration, reduced plaque formation, and lower concentrations of blood inflammatory cytokines than those observed in the control mice. The results suggest that the consumption of anthocyanin-rich red Chinese cabbage is closely correlated with lowering the risk of vascular inflammatory diseases.

Oridonin inhibits vascular inflammation by blocking NF-κB and MAPK activation

Oridonin, an active diterpenoid compound isolated from the plant Rabdosia Rrubescens, has various pharmacological activities, including antioxidant, anti-tumor capacities and anti-inflammation. In the present study, we explore the role of oridonin in regulating endothelial inflammation and its underlying mechanism. Endothelial cell-monocyte interaction was detected by Leukocyte-endothelium Adhesion Assay. The protein expression was measured by Western blot. NF-κB p65 translocation was measured by immunofluorescence. Acute lung inflammation model was used to evaluate leukocyte infiltration in vivo. The endothelial-leukocyte adhesion and the leukocyte transmigration were profoundly reduced by oridonin. Oridonin dramatically inhibited the expression of TNF-α-induced endothelial adhesion molecules (intercellular adhesion molecule-1 (ICAM-1); vascular cell adhesion molecule-1 (VCAM-1) and E-selectin) and the pro-inflammatory cytokine (IL-6, IL-8 and monocyte chemoattractant protein-1(MCP-1)). Oridonin suppressed the penetration of the leukocyte in the acute lung injury mice model. Furthermore, Oridonin also suppressed the TNF-α-activated MAPK and Nuclear factor kappa B (NF-κB) activation. Our results suggest that oridonin has the anti-inflammatory properties in endothelial cells, at least in part, through the suppression of MAPK and NF-κB activation, which may have a potential therapeutic use for inflammatory vascular diseases.

Endothelial Cdc42 deficiency impairs endothelial regeneration and vascular repair after inflammatory vascular injury

BackgroundEndothelial cell (EC) regeneration is essential for inflammation resolution and vascular integrity recovery after inflammatory vascular injury. Cdc42 is a central regulator of cell survival and vessel formation in EC development. However, it is unknown that whether Cdc42 could be a regulating role of EC repair following the inflammatory injury in the lung. The study sought to test the hypothesis that Cdc42 is required for endothelial regeneration and vascular integrity recovery after LPS-induced inflammatory injury.Methods and resultsThe role of Cdc42 for the regulation of pulmonary vascular endothelial repair was tested in vitro and in vivo. In LPS-induced acute lung injury (ALI) mouse models, knockout of the Cdc42 gene in ECs increased inflammatory cell infiltration and pulmonary vascular leakage and inhibited vascular EC proliferation, which eventually resulted in more severe inflammatory lung injury. In addition, siRNA-mediated knockdown of Cdc42 protein on ECs disrupted cell proliferation and migration and tube formation, which are necessary processes for recovery after inflammatory vascular injury, resulting in inflammatory vascular injury recovery defects.ConclusionWe found that Cdc42 deficiency impairs EC function and regeneration, which are crucial in the post-inflammatory vascular injury repair process. These findings indicate that Cdc42 is a potential target for novel treatments designed to facilitate endothelial regeneration and vascular repair in inflammatory pulmonary vascular diseases, such as ALI/ARDS.

Clinical and imaging features and etiologic diagnosis value in patients with cavernous sinus lesion presenting with ophthalmoplegia

Objective: To classify different causes of cavernous sinus lesion in patients with ophthalmoplegia and analyze their clinical and imaging features. Methods: We confirmed the etiological diagnosis of 137 hospitalized ophthalmoplegia patients with cavernous sinus lesion retrospectively from January 2005 to January 2014 in the Department of Neurology of Beijing Tongren Hospital.The diagnosis was made according to clinical feature, laboratory test, imaging studies and pathology.The clinical data of these patients were analyzed and compared among different groups. Results: Fifty-one cases (37.2%) were confirmed as inflammatory diseases of cavernous sinus, which were the most common cause in 137 patients.Early stage pain (OR 5.591, 95%CI 1.703-18.401) and involvement of oculomotor nerve (OR 4.902, 95%CI 1.015-24.630) were independently associated with inflammatory diseases.Forty-three cases (31.3%) were confirmed to have tumor, which was the second cause of cavernous sinus lesions, and meningioma was the most common tumor.The second branch of trigeminal nerve involvement was independently correlated (OR 1.017, 95%CI 1.005-1.071) with tumor.The percentage of male (OR 3.506, 95%CI 1.362-8.765) was significantly higher in 28 cases (20.4%) with cavernous sinus vascular lesions.Cavernous sinus infectious diseases were seen in 15 cases (10.9%), and fungal infection was the most common, mostly secondary to sinus infection. Conclusions: The common causes of cavernous sinus lesion include cavernous sinus inflammatory diseases, neoplastic diseases, vascular diseases and infectious diseases, and inflammatory diseases is the most commonly seen cause in this group of patients.Obvious facial sensory disturbances and the second branch of trigeminal nerve involvement are independent associated with tumor.The early course of pain and involvement of oculomotor nerve are associated with inflammatory diseases.Optimization of MRI examination method can better identify the cavernous sinus lesions.

Endothelial nitric oxide synthase modulates Toll-like receptor 4-mediated IL-6 production and permeability via nitric oxide-independent signaling.

Endothelial dysfunction, characterized by changes in eNOS, is a common finding in chronic inflammatory vascular diseases. These states are associated with increased infectious complications. We hypothesized that alterations in eNOS would enhance the response to LPS-mediated TLR4 inflammation. Human microvascular endothelial cells were treated with sepiapterin or N-nitro-L-arginine methylester (L-NAME) to alter endogenous NO production, and small interfering RNA to knockdown eNOS. Alterations of endogenous NO by sepiapterin, and L-NAME provided no significant changes to LPS inflammation. In contrast, eNOS knockdown greatly enhanced endothelial IL-6 production and permeability in response to LPS. Knockdown of eNOS enhanced LPS-induced p38. Inhibition of p38 with SB203580 prevented IL-6 production, without altering permeability. Knockdown of p38 impaired NF-κB activation. Physical interaction between p38 and eNOS was demonstrated by immunoprecipitation, suggesting a novel, NO-independent mechanism for eNOS regulation of TLR4. In correlation, biopsy samples in patients with systemic lupus erythematous showed reduced eNOS expression with associated elevations in TLR4 and p38, suggesting an in vivo link. Thus, reduced expression of eNOS, as seen in chronic inflammatory disease, was associated with enhanced TLR4 signaling through p38. This may enhance the response to infection in patients with chronic inflammatory conditions.-Stark, R. J., Koch, S. R., Choi, H., Mace, E. H., Dikalov, S. I., Sherwood, E. R., Lamb, F. S. Endothelial nitric oxide synthase modulates Toll-like receptor 4-mediated IL-6 production and permeability via nitric oxide-independent signaling.

Selenoprotein S Attenuates Tumor Necrosis Factor-α-Induced Dysfunction in Endothelial Cells.

Endothelial dysfunction, partly induced by inflammatory mediators, is known to initiate and promote several cardiovascular diseases. Selenoprotein S (SelS) has been identified in endothelial cells and is associated with inflammation; however, its function in inflammation-induced endothelial dysfunction has not been described. We first demonstrated that the upregulation of SelS enhances the levels of nitric oxide and endothelial nitric oxide synthase in tumor necrosis factor- (TNF-) α-treated human umbilical vein endothelial cells (HUVECs). The levels of TNF-α-induced endothelin-1 and reactive oxygen species are also reduced by the upregulation of SelS. Furthermore, SelS overexpression blocks the TNF-α-induced adhesion of THP-1 cells to HUVECs and inhibits the increase in intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. Moreover, SelS overexpression regulates TNF-α-induced inflammatory factors including interleukin-1β, interleukin-6, interleukin-8, and monocyte chemotactic protein-1 and attenuates the TNF-α-induced activation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways. Conversely, the knockdown of SelS with siRNA results in an enhancement of TNF-α-induced injury in HUVECs. These findings suggest that SelS protects endothelial cells against TNF-α-induced dysfunction by inhibiting the activation of p38 MAPK and NF-κB pathways and implicates it as a possible modulator of vascular inflammatory diseases.

Inflammation-regulated mRNA stability and the progression of vascular inflammatory diseases.

Cardiovascular disease remains a major medical and socioeconomic burden in developed and developing societies, and will increase with an aging and increasingly sedentary society. Vascular disease and atherosclerotic vascular syndromes are essentially inflammatory disorders, and transcriptional and post-transcriptional processes play essential roles in the ability of resident vascular and inflammatory cells to adapt to environmental stimuli. The regulation of mRNA translocation, stability, and translation are key processes of post-transcriptional regulation that permit these cells to rapidly respond to inflammatory stimuli. For the most part, these processes are controlled by elements in the 3'-UTR of labile, proinflammatory transcripts. Since proinflammatory transcripts almost exclusively contain AU-rich elements (AREs), this represents a tightly regulated and specific mechanism for initiation and maintenance of the proinflammatory phenotype. RNA-binding proteins (RBPs) recognize cis elements in 3'-UTR, and regulate each of these processes, but there is little literature exploring the concept that RBPs themselves can be directly regulated by inflammatory stimuli. Conceptually, inflammation-responsive RBPs represent an attractive target of rational therapies to combat vascular inflammatory syndromes. Herein we briefly describe the cellular and molecular etiology of atherosclerosis, and summarize our current understanding of RBPs and their specific roles in regulation of inflammatory mRNA stability. We also detail RBPs as targets of current anti-inflammatory modalities and how this may translate into better treatment for vascular inflammatory diseases.

The Role of Gap Junction-Mediated Endothelial Cell-Cell Interaction in the Crosstalk between Inflammation and Blood Coagulation.

Endothelial cells (ECs) play a pivotal role in the crosstalk between blood coagulation and inflammation. Endothelial cellular dysfunction underlies the development of vascular inflammatory diseases. Recent studies have revealed that aberrant gap junctions (GJs) and connexin (Cx) hemichannels participate in the progression of cardiovascular diseases such as cardiac infarction, hypertension and atherosclerosis. ECs can communicate with adjacent ECs, vascular smooth muscle cells, leukocytes and platelets via GJs and Cx channels. ECs dynamically regulate the expression of numerous Cxs, as well as GJ functionality, in the context of inflammation. Alterations to either result in various side effects across a wide range of vascular functions. Here, we review the roles of endothelial GJs and Cx channels in vascular inflammation, blood coagulation and leukocyte adhesion. In addition, we discuss the relevant molecular mechanisms that endothelial GJs and Cx channels regulate, both the endothelial functions and mechanical properties of ECs. A better understanding of these processes promises the possibility of pharmacological treatments for vascular pathogenesis.

Regulation of endothelial intracellular adenosine via adenosine kinase epigenetically modulates vascular inflammation

The molecular mechanisms underlying vascular inflammation and associated inflammatory vascular diseases are not well defined. Here we show that endothelial intracellular adenosine and its key regulator adenosine kinase (ADK) play important roles in vascular inflammation. Pro-inflammatory stimuli lead to endothelial inflammation by increasing endothelial ADK expression, reducing the level of intracellular adenosine in endothelial cells, and activating the transmethylation pathway through increasing the association of ADK with S-adenosylhomocysteine (SAH) hydrolase (SAHH). Increasing intracellular adenosine by genetic ADK knockdown or exogenous adenosine reduces activation of the transmethylation pathway and attenuates the endothelial inflammatory response. In addition, loss of endothelial ADK in mice leads to reduced atherosclerosis and affords protection against ischemia/reperfusion injury of the cerebral cortex. Taken together, these results demonstrate that intracellular adenosine, which is controlled by the key molecular regulator ADK, influences endothelial inflammation and vascular inflammatory diseases.

Antiseptic effects of dabrafenib on TGFBIp-induced septic responses

Transforming growth factor-β-induced protein (TGFBIp), an extracellular protein, is expressed on several cell types in response to TGF-β stimulation. Human umbilical vein endothelial cell (HUVEC)-derived TGFBIp functions as a mediator of sepsis. Screening of bioactive compound libraries is an effective approach for repositioning FDA-approved drugs or discovering new treatments for human diseases (drug repositioning). Dabrafenib (DAB), a B-Raf inhibitor, was initially used for treating metastatic melanoma. The present study determined whether DAB modulated TGFBIp-mediated septic responses in HUVECs and in mice. Antiseptic functions of DAB were examined by measuring permeability, leukocyte adhesion and migration, and proinflammatory protein activation in TGFBIp-stimulated HUVECs and mice. In addition, beneficial effects of DAB on survival rate were examined using a mouse model of sepsis. We found that DAB inhibited TGFBIp-induced vascular barrier disruption, cell adhesion molecule (CAM) expression, and neutrophil adhesion/transendothelial migration toward human endothelial cells. DAB also suppressed TGFBIp-induced hyperpermeability and leukocyte migration in vivo. These results suggest that DAB exerts anti-inflammatory effects by inhibiting hyperpermeability, CAM expression, and leukocyte adhesion and migration, indicating its utility for treating vascular inflammatory diseases.

Chapter 7 - Neuropathology of cerebrovascular diseases

The chapter describes the epidemiology of cerebrovascular diseases, anatomy of the cerebral blood vessels, pathophysiology of ischemia, hypoxia, hypoxemia, anemic hypoxia, histotoxic hypoxia, carbon monoxide damage, hyperoxid brain damage and decompression sickness, and selective cell and regional vulnerability; diseases of the blood vessels including atherosclerosis, hypertensive angiopathy, small vessel disease, inflammatory vascular diseases, cerebral amyloid angiopathies, CADASIL, CARASIL and other diseases that can lead to cerebrovascular occlusion; intracranial and intraspinal aneurysms and vascular malformations; hematologic disorders that can cause cerebral infarct or hemorrhage; brain ischemic damage; and spontaneous intracranial bleeding. Within ischemic brain damage, focal cerebral ischemia, hemorrhagic infarct, brain edema, penumbra, global cerebral ischemia, venous thrombosis, lacunas and lacunar state, status cribosus, granular atrophy of the cerebral cortex, hippocampal sclerosis, vascular leukoencephalopathy Binswanger type and multi-infarct encephalopathy are discussed in detail. Cognitive impairment of vascular origin deserves an individual section.

Suppressive Effects of Sulforaphane on TGFBIp-mediated Sepsis

Sulforaphane (SFN) is produced when the enzyme myrosinase transforms glucoraphanin upon damage to the plant such as from chewing and effective in preventing carcinogenesis, diabetes, and inflammatory responses. Transforming growth factor β-induced protein (TGFBIp) is an extracellular matrix protein whose expression in several cell types is greatly increased by TGF-β. TGFBIp is released by human umbilical vein endothelial cells (HUVECs) and functions as a mediator of experimental sepsis. We hypothesized that SFN could reduce TGFBIp-mediated severe inflammatory responses in human endothelial cells and mice. Here, we investigated the anti-septic effects and underlying mechanisms of SFN against TGFBIp-mediated septic responses. SFN effectively inhibited lipopolysaccharide-induced release of TGFBIp and suppressed TGFBIp-mediated septic responses. In addition, SFN suppressed cecal ligation and puncture (CLP)-induced sepsis lethality and pulmonary injury. In conclusion, SFN suppressed TGFBIp-mediated and CLP-induced septic responses. Therefore, SFN could be a potential therapeutic agent for treatment of various severe vascular inflammatory diseases via inhibition of the TGFBIp signaling pathway.