Assessing the Effectiveness of a Community-based Livestock Insurance Program

Financial mechanisms to mitigate the costs of negative human-carnivore interactions are frequently promoted to support human coexistence with carnivores. Yet, evidence to support their performance in different settings is scarce. We evaluated a community-based livestock insurance program implemented as part of a broader snow leopard conservation effort in the Tost Tosonbumba Nature Reserve, South Gobi, Mongolia. We assessed program efficiency and effectiveness for snow leopard conservation using a results-based evaluation approach. Data sources included program records from 2009 to 2018, as well as surveys conducted in 2016 and 2017, which allowed us to compare key indicators across communities that participated in the insurance program and control communities. Program coverage and number of livestock insured rapidly increased over the years to reach 65% of households and close to 11,000 livestock. Participants expressed satisfaction with the program and their contributions increased over time, with an increasing proportion (reaching 64% in 2018) originating from participant premiums, suggesting strong community ownership of the program. Participants were less likely to report the intention to kill a snow leopard and reported fewer livestock losses than respondents from control communities, suggesting increased engagement in conservation efforts. These results together suggest that the insurance program achieved its expected objectives, although it is challenging to disentangle the contributions of each individual conservation intervention implemented in intervention communities. However, in the first three years of the program, snow leopard mortalities continued to be reported suggesting that additional interventions were needed to reach impact in terms of reducing retaliatory killings of large carnivores.

Autologous Adipose Tissue-Derived Mesenchymal Stem Cells Introduced by Biliary Stents or Local Immersion in Porcine Bile Duct Anastomoses

Biliary complications (strictures and leaks) represent major limitations in living donor liver transplantation. Mesenchymal stem cells (MSCs) are a promising modality to prevent biliary complications because of immunosuppressive and angiogenic properties. Our goal was to evaluate the safety of adipose-derived MSC delivery to biliary anastomoses in a porcine model. Secondary objectives were defining the optimal method of delivery (intraluminal versus extraluminal) and to investigate MSC engraftment, angiogenesis, and fibrosis. Pigs were divided into 3 groups. Animals underwent adipose collection, MSC isolation, and expansion. Two weeks later, animals underwent bile duct transection, reanastomosis, and stent insertion. Group 1 received plastic stents wrapped in unseeded Vicryl mesh. Group 2 received stents wrapped in MSC-seeded mesh. Group 3 received unwrapped stents with the anastomosis immersed in an MSC suspension. Animals were killed 1 month after stent insertion when cholangiograms and biliary tissue were obtained. Serum was collected for liver biochemistries. Tissue was used for hematoxylin-eosin and trichrome staining and immunohistochemistry for MSC markers (CD44 and CD34) and for a marker of neoangiogenesis (CD31). There were no intraoperative complications. One pig died on postoperative day 3 due to acute cholangitis. All others recovered without complications. Cholangiography demonstrated no biliary leaks and minimal luminal narrowing. Surviving animals exhibited no symptoms, abnormal liver biochemistries, or clinically significant biliary stricturing. Group 3 showed significantly greater CD44 and CD34 staining, indicating MSC engraftment. Fibrosis was reduced at the anastomotic site in group 3 based on trichrome stain. CD31 staining of group 3 was more pronounced, supporting enhanced neoangiogenesis. In conclusion, adipose-derived MSCs were safely applied to biliary anastomoses. MSCs were locally engrafted within the bile duct and may have beneficial effects in terms of fibrosis and angiogenesis.

Venous thromboembolism in IBD: Increased risk for women in CD?

Although coagulation disturbances have been described in inflammatory bowel disease (IBD), it remains unclear how common venous thromboembolism (VTE) is in IBD, and what factors influence VTE frequency. We evaluated VTE in Crohn's disease (CD) and ulcerative colitis (UC) at LSUHSC-S, a southern US medical center with an approximately equal White: African-American (AA) (1.12:1) patient base. This retrospective study evaluated VTE as a co-morbidity in IBD as a function of age, gender and race based on ICD-10 coding (2011-2015.) Results. Of 276 IBD diagnostic records, 213 were for CD (77.17%) and 63 for UC (22.8%). 52% of the CD patients were white, 42% were AA, and 6% were other. 42% of CD patients were male, with 58% were female. 6.1% (13 patients) of the 213 CD patients had a VTE. Of these 13 CD patients, 9 had active disease and 4 were in remission. 9 of 13 were female and 4 were male, with 5 white patients and 4 A A patients. 63 patients were diagnosed with UC, 3.38-fold fewer cases than CD. 25 UC patients were white, 25 were AA and 13 were in other ethnic groups. Of 63 UC cases, 2 UC patients had a VTE, both with active disease. At our institution, VTE appears to be 3x more frequently associated with CD than UC and was more common in white female patients. The recognition of VTE risk in CD, particularly in women, may be an important observation which may guide therapy and limit potentially life-threatening consequences.

Potential therapeutic roles of stem cells in ischemia-reperfusion injury

Ischemia-reperfusion injury (I/RI), produced by an initial interruption of organ blood flow and its subsequent restoration, contributes significantly to the pathophysiologies of stroke, myocardial infarction, renal I/RI, intestinal I/RI and liver I/RI, which are major causes of disability (including transplant failure) and even mortality. While the restoration of blood flow is required to restore oxygen and nutrient requirements, reperfusion often triggers local and systemic inflammatory responses and subsequently elevate the ischemic insult where the duration of ischemia determines the magnitude of I/RI damage. I/RI increases vascular leakage, changes transcriptional and cell death programs, drives leukocyte entrapment and inflammation and oxidative stress in tissues. Therapeutic approaches which reduce complications associated with I/RI are desperately needed to address the clinical and economic burden created by I/RI. Stem cells (SC) represent ubiquitous and uncommitted cell populations with the ability to self-renew and differentiate into one or more developmental 'fates'. Like immune cells, stem cells can home to and penetrate I/R-injured tissues, where they can differentiate into target tissues and induce trophic paracrine signaling which suppress injury and maintain tissue functions perturbed by ischemia-reperfusion. This review article summarizes the present use and possible protective mechanisms underlying stem cell protection in diverse forms of ischemia-reperfusion.

Hydrogen sulfide: Therapeutic or injurious in ischemic stroke?

Hydrogen sulfide (H2S) has been identified as a vasodilatory, neuromodulatory, and anti-inflammatory gasotransmitter with antioxidant properties. Studies focused in cardiac tissue suggest H2S functions as a protective agent; however in the central nervous system (CNS) the effects of H2S during states of stress or injury, such as stroke, remain controversial. Currently, the application of H2S donors and modulators in stroke depends on the type of H2S donor and the timing of the therapy.

Livestock depredation by large carnivores in the South Gobi, Mongolia

Context Livestock depredation is a major conservation challenge around the world, causing considerable economical losses to pastoral communities and often result in retaliatory killing. In Mongolia, livestock depredation rates are thought to be increasing due to changes in pastoral practices and the transformation of wild habitats into pasture lands. Few studies have examined the interactions between humans and carnivores and even fewer have considered how recent changes in pastoral practices may affect depredation rates. Aim This study aimed to assess the influence of herding practices on self-reported livestock losses to snow leopards and wolves in two communities in South Gobi, Mongolia. Methods In total, 144 herder households were interviewed and an information-theoretic approach was used to analyse the factors influencing self-reported livestock losses to snow leopards and wolves. Key results The majority of self-reported losses to both snow leopards and wolves occurred when herds were left unattended in the pastures. The economic loss associated with livestock losses to snow leopards and wolves amounted to an average loss of US$825 per herder and year. The number of livestock owned by a household and the frequency of shifting campsite had the strongest influence on livestock losses to snow leopards and wolves. Other determinants of livestock losses included frequency of visiting the soum (county) centre. Implications On the basis of the findings, we make recommendations for mitigating the conflict with large carnivores, with focus on guiding future herding practices.

Corrigendum to: Livestock depredation by large carnivores in the South Gobi, Mongolia

Context Livestock depredation is a major conservation challenge around the world, causing considerable economical losses to pastoral communities and often result in retaliatory killing. In Mongolia, livestock depredation rates are thought to be increasing due to changes in pastoral practices and the transformation of wild habitats into pasture lands. Few studies have examined the interactions between humans and carnivores and even fewer have considered how recent changes in pastoral practices may affect depredation rates. Aim This study aimed to assess the influence of herding practices on self-reported livestock losses to snow leopards and wolves in two communities in South Gobi, Mongolia. Methods In total, 144 herder households were interviewed and an information-theoretic approach was used to analyse the factors influencing self-reported livestock losses to snow leopards and wolves. Key results The majority of self-reported losses to both snow leopards and wolves occurred when herds were left unattended in the pastures. The economic loss associated with livestock losses to snow leopards and wolves amounted to an average loss of US$825 per herder and year. The number of livestock owned by a household and the frequency of shifting campsite had the strongest influence on livestock losses to snow leopards and wolves. Other determinants of livestock losses included frequency of visiting the soum (county) centre. Implications On the basis of the findings, we make recommendations for mitigating the conflict with large carnivores, with focus on guiding future herding practices.

Patterns of Snow Leopard Site Use in an Increasingly Human-Dominated Landscape

Human population growth and concomitant increases in demand for natural resources pose threats to many wildlife populations. The landscapes used by the endangered snow leopard (Panthera uncia) and their prey is increasingly subject to major changes in land use. We aimed to assess the influence of 1) key human activities, as indicated by the presence of mining and livestock herding, and 2) the presence of a key prey species, the blue sheep (Pseudois nayaur), on probability of snow leopard site use across the landscape. In Gansu Province, China, we conducted sign surveys in 49 grid cells, each of 16 km² in size, within a larger area of 3392 km². We analysed the data using likelihood-based habitat occupancy models that explicitly account for imperfect detection and spatial auto-correlation between survey transect segments. The model-averaged estimate of snow leopard occupancy was high [0.75 (SE 0.10)], but only marginally higher than the naïve estimate (0.67). Snow leopard segment-level probability of detection, given occupancy on a 500 m spatial replicate, was also high [0.68 (SE 0.08)]. Prey presence was the main determinant of snow leopard site use, while human disturbances, in the form of mining and herding, had low predictive power. These findings suggest that snow leopards continue to use areas very close to such disturbances, as long as there is sufficient prey. Improved knowledge about the effect of human activity on large carnivores, which require large areas and intact prey populations, is urgently needed for conservation planning at the local and global levels. We highlight a number of methodological considerations that should guide the design of such research.

Blood circulating microparticle species in relapsing-remitting and secondary progressive multiple sclerosis. A case-control, cross sectional study with conventional MRI and advanced iron content imaging outcomes

BACKGROUND

Although multiple sclerosis (MS) is thought to represent an excessive and inappropriate immune response to several central nervous system (CNS) autoantigens, increasing evidence also suggests that MS may also be a neurovascular inflammatory disease, characterized by endothelial activation and shedding of cell membrane microdomains known as 'microparticles' into the circulation.

OBJECTIVE

To investigate the relationships between these endothelial biomarkers and MS.

METHODS

We examined the relative abundance of CD31(+)/PECAM-1, CD51(+)CD61(+) (αV-β3) and CD54(+) (ICAM-1) bearing microparticles in sera of healthy individuals, patients with relapsing-remitting MS, and secondary-progressive MS. We also investigated the correlation among circulating levels of different microparticle species in MS with conventional MRI (T2- and T1-lesion volumes and brain atrophy), as well as novel MR modalities [assessment of iron content on susceptibility-weighted imaging (SWI)-filtered phase].

RESULTS

Differences in circulating microparticle levels were found among MS groups, and several microparticle species (CD31(+)/CD51(+)/CD61(+)/CD54(+)) were found to correlate with conventional MRI and SWI features of MS.

CONCLUSION

These results indicate that circulating microparticles' profiles in MS may support mechanistic roles for microvascular stress and injury which is an underlying contributor not only to MS initiation and progression, but also to pro-inflammatory responses.

IL-1β reduces tonic contraction of mesenteric lymphatic muscle cells, with the involvement of cycloxygenase-2 and prostaglandin E2

BACKGROUND AND PURPOSE

The lymphatic system maintains tissue homeostasis by unidirectional lymph flow, maintained by tonic and phasic contractions within subunits, 'lymphangions'. Here we have studied the effects of the inflammatory cytokine IL-1β on tonic contraction of rat mesenteric lymphatic muscle cells (RMLMC).

EXPERIMENTAL APPROACH

We measured IL-1β in colon-conditioned media (CM) from acute (AC-CM, dextran sodium sulfate) and chronic (CC-CM, T-cell transfer) colitis-induced mice and corresponding controls (Con-AC/CC-CM). We examined tonic contractility of RMLMC in response to CM, the cytokines h-IL-1β or h-TNF-α (5, 10, 20 ng·mL(-1) ), with or without COX inhibitors [TFAP (10(-5)  M), diclofenac (0.2 × 10(-5)  M)], PGE2 (10(-5)  M)], IL-1-receptor antagonist, Anakinra (5 μg·mL(-1) ), or a selective prostanoid EP4 receptor antagonist, GW627368X (10(-6) and 10(-7)  M).

KEY RESULTS

Tonic contractility of RMLMC was reduced by AC- and CC-CM compared with corresponding control culture media, Con-AC/CC-CM. IL-1β or TNF-α was not found in Con-AC/CC-CM, but detected in AC- and CC-CM. h-IL-1β concentration-dependently decreased RMLMC contractility, whereas h-TNF-α showed no effect. Anakinra blocked h-IL-1β-induced RMLMC relaxation, and with AC-CM, restored contractility to RMLMC. IL-1β increased COX-2 protein and PGE2 production in RMLMC.. PGE2 induced relaxations in RMLMC, comparable to h-IL-1β. Conversely, COX-2 and EP4 receptor inhibition reversed relaxation induced by IL-1β.

CONCLUSIONS AND IMPLICATIONS

The IL-1β-induced decrease in RMLMC tonic contraction was COX-2 dependent, and mediated by PGE2 . In experimental colitis, IL-1β and tonic lymphatic contractility were causally related, as this cytokine was critical for the relaxation induced by AC-CM and pharmacological blockade of IL-1β restored tonic contraction.

Number and location of drainage catheter side holes: in vitro evaluation

AIM

To evaluate the influence of number and location of catheter shaft side holes regarding drainage efficiency in an in vitro model.

MATERIALS AND METHODS

Three different drainage catheter models were constructed: open-ended model with no side holes (one catheter), unilateral side hole model (six catheters with one to six unilateral side holes), and bilateral side hole model (six catheters with one to six bilateral side holes). Catheters were inserted into a drainage output-measuring device with a constant-pressure reservoir of water. The volume of water evacuated by each of the catheters at 10-second intervals was measured. A total of five trials were performed for each catheter. Data were analysed using one-way analysis of variance.

RESULTS

The open-ended catheter had a mean drainage volume comparable to the unilateral model catheters with three, four, and five side holes. Unilateral model catheters had significant drainage volume increases up to three side holes; unilateral model catheters with more than three side holes had no significant improvement in drainage volume. All bilateral model catheters had significantly higher mean drainage volumes than their unilateral counterparts. There was no significant difference between the mean drainage volume with one, two, or three pairs of bilateral side holes. Further, there was no drainage improvement by adding additional bilateral side holes.

CONCLUSION

The present in vitro study suggests that beyond a critical side hole number threshold, adding more distal side holes does not improve catheter drainage efficiency. These results may be used to enhance catheter design towards improving their drainage efficiency.

TGF-β1-induced EMT promotes targeted migration of breast cancer cells through the lymphatic system by the activation of CCR7/CCL21-mediated chemotaxis

Tumor cells frequently disseminate through the lymphatic system during metastatic spread of breast cancer and many other types of cancer. Yet it is not clear how tumor cells make their way into the lymphatic system and how they choose between lymphatic and blood vessels for migration. Here we report that mammary tumor cells undergoing epithelial–mesenchymal transition (EMT) in response to transforming growth factor-β (TGF-β1) become activated for targeted migration through the lymphatic system, similar to dendritic cells (DCs) during inflammation. EMT cells preferentially migrated toward lymphatic vessels compared with blood vessels, both in vivo and in 3D cultures. A mechanism of this targeted migration was traced to the capacity of TGF-β1 to promote CCR7/CCL21-mediated crosstalk between tumor cells and lymphatic endothelial cells. On one hand, TGF-β1 promoted CCR7 expression in EMT cells through p38 MAP kinase-mediated activation of the JunB transcription factor. Blockade of CCR7, or treatment with a p38 MAP kinase inhibitor, reduced lymphatic dissemination of EMT cells in syngeneic mice. On the other hand, TGF-β1 promoted CCL21 expression in lymphatic endothelial cells. CCL21 acted in a paracrine fashion to mediate chemotactic migration of EMT cells toward lymphatic endothelial cells. The results identify TGF-β1-induced EMT as a mechanism, which activates tumor cells for targeted, DC-like migration through the lymphatic system. Furthermore, it suggests that p38 MAP kinase inhibition may be a useful strategy to inhibit EMT and lymphogenic spread of tumor cells.

Lymphatic dysregulation in intestinal inflammation: new insights into inflammatory bowel disease pathomechanisms

Alterations in the intestinal lymphatic network are well-established features of human and experimental inflammatory bowel disease (IBD). Such lymphangiogenic expansion might enhance classic intestinal lymphatic transport, eliminating excess accumulations of fluid, inflammatory cells and mediators, and could therefore be interpreted as an 'adaptive' response to acute and chronic inflammatory processes. However, whether these new lymphatic vessels are functional, unregulated or immature (and what factors may promote 'maturation' of these vessels) is currently an area under intense investigation. It is still controversial whether impaired lymphatic function in IBD is a direct consequence of the intestinal inflammation, or a preceding lymphangitis-like event. Current research has uncovered novel regulatory factors as well as new roles for familiar signaling pathways, which appear to be linked to inflammation-induced lymphatic alterations. The current review summarizes mechanisms amplifying lymphatic dysregulation and remodeling in intestinal inflammation at the organ, cell and molecular levels and discusses the influence of lymphangiogenesis and intestinal lymphatic transport function as they relate to IBD pathophysiology.

Abstract 333: Chemokine and Autophagy-Related Genes in Novel In Vivo and In Vitro Models for Viral Myocarditis

Picornavirus infection is one of leading causes of myocarditis in humans. Theiler's murine encephalomyelitis virus (TMEV) belongs to the genus Cardiovirus , the family Picornaviridae . While TMEV has been used as a mouse model for multiple sclerosis (MS), TMEV can also cause myocarditis in mice. We found that the susceptibilities of mouse strains to myocarditis differed from susceptibilities to the MS model. In the heart, we detected viral replication and inflammation. However, it is unclear whether virus itself or immune cells damaged the heart. To clarify the role of direct virus infection in myocarditis we used the cardiomyocyte cell line, HL-1, which retains a differentiated cardiomyocyte phenotype and contractile activity. We infected HL-1 with TMEV and monitored cytopathic effect (CPE) and cell viability. At 8 hours post infection (hpi), HL-1 cells developed CPE with decreased contractile activities, while cell death was not obvious. We detected 54% and 93% of cell death at 12 and 24 hpi, respectively, while no cell death was observed in mock-infection. We conducted microarray analyses to compare mRNA expression patterns between TMEV and mock-infected groups, using an Affymetrix GeneChip Mouse 1.0 ST Array. Principal component analysis (PCA) for microarray data clearly separated TMEV- and mock-infected groups (PC1 proportion of variance, 59%). TMEV infection induced high expression of several interferon-associated and chemokine genes, particularly Cxcl10/IP-10 . Cxcl10 is a potent chemoattractant for activated T cells and NK cells, and its potential roles have been associated with immune cells in other myocarditis models. Our current results demonstrated that virus infection alone could induce Cxcl10 in cardiomyocytes without immune cells. We also found upregulation of autophagy-related 12 gene ( Atg12 ). In general, autophagy can contribute to eradication of intracellular pathogens including viruses. However, since induction of autophagy by picornavirus has been shown to enhance virus replication, autophagy may also play a detrimental role in TMEV-induced myocarditis. Our novel in viv o and in vitro models of myocarditis are powerful tools to dissect the role of viral and immune pathogenesis of the heart, complementing each other.

PAR-2 triggers placenta-derived protease-induced altered VE-cadherin reorganization at endothelial junctions in preeclampsia

PAR-2 is a G-protein coupled protease receptor whose activation in endothelial cells (ECs) is associated with increased solute permeability. VE-cadherin is an endothelial-specific junction protein, which exhibits a disorganized distribution at cell junction during inflammation and is a useful indicator of endothelial barrier dysfunction. In the present study, we tested the hypothesis that PAR-2 activation mediates placenta-derived chymotrypsin-like protease (CLP)-induced endothelial junction disturbance and permeability in preeclampsia (PE). PAR-2 and VE-cadherin were examined by immunofluorescent staining. Specific CLP induced PAR-2 activation and altered VE-cadherin distribution was assessed following depletion of protease chymotrypsin in the placental conditioned medium and after PAR-2 siRNA. VE-cadherin assembly was determined by treating cells with protease chymotrypsin and/or the specific PAR-2 agonist SLIGKV-NH2. Our results showed: 1) placental conditioned medium not only disturbed VE-cadherin distribution at cell junctions but also activated PAR-2 in ECs; 2) PAR-2 siRNA blocked the placental conditioned medium induced PAR-2 upregulation and disorganization of VE-cadherin at cell junctions; 3) PAR-2 agonist induced PAR-2 activation and VE-cadherin reorganization were dose-dependent; and 4) PAR-2 agonist could stimulate ERK1/2 activation. These results strongly suggest that proteases produced by the placenta elicit endothelial barrier dysfunction via a PAR-2 signaling regulatory mechanism in PE.

Gastrointestinal lymphatics in health and disease

Lymphatics perform essential transport and immune regulatory functions to maintain homeostasis in the gastrointestinal (GI) system. Although blood and lymphatic vessels function as parallel and integrated systems, our understanding of lymphatic structure, regulation and functioning lags far behind that of the blood vascular system. This chapter reviews lymphatic flow, differences in lymphangiogenic and hemangiogenic factors, lymphatic fate determinants and structural features, and examines how altered molecular signaling influences lymphatic function in organs of the GI system. Innate errors in lymphatic development frequently disturb GI functioning and physiology. Expansion of lymphatics, a prominent feature of GI inflammation, may also play an important role in tissue restitution following injury. Destruction or dysregulation of lymphatics, following injury, surgery or chronic inflammation also exacerbates GI disease activity. Understanding the physiological roles played by GI lymphatics is essential to elucidating their underlying contributions to forms of congenital and acquired forms of GI pathology, and will provide novel approaches for therapy.

Differential cytokine responses in human and mouse lymphatic endothelial cells to cytokines in vitro

BACKGROUND

Inflammatory cytokines dysregulate microvascular function, yet how cytokines affect lymphatic endothelial cells (LEC) are unclear.

METHODS AND RESULTS

We examined effects of TNF-α, IL-1 beta, and IFN-gamma on LEC proliferation, endothelial cell adhesion molecule (ECAM) expression, capillary formation, and barrier changes in murine (SV-LEC) and human LECs (HMEC-1a).

RESULTS

All cytokines induced ICAM-1, VCAM-1, MAdCAM-1, and E-selectin in SV-LECs; TNF-α, IL-1 beta; and IFN-gamma induced ECAMs (but not MAdCAM-1) in HMEC-1a. IL-1 beta increased, while IFN-gamma and TNF-α reduced SV-LEC proliferation. While TNF-α induced, IFN-gamma decreased, and IL-1 beta did not show any effect on HMEC-1a proliferation. TNF-α, IL-1 beta, and IFN-gamma each reduced capillary formation in SV-LEC and in HMEC-1a. TNF-α and IL-1 beta reduced barrier in SV-LEC and HMEC-1a; IFN-gamma did not affect SV-LEC barrier, but enhanced HMEC-1a barrier. Inflammatory cytokines alter LEC growth, activation and barrier function in vitro and may disturb lymphatic clearance increasing tissue edema in vivo.

CONCLUSION

Therapies that maintain or restore lymphatic function (including cytokines blockade), may represent important strategies for limiting inflammation.

The fungicide ciclopirox inhibits lymphatic endothelial cell tube formation by suppressing VEGFR-3-mediated ERK signaling pathway

Ciclopirox olamine (CPX), an off-patent antifungal agent used to treat mycoses of skin and nails, has recently been demonstrated to be a potential anticancer agent. However, the underlying mechanism is not well understood. Here for the first time we show that CPX inhibited lymphangiogenesis in an in vitro model (tube formation). This effect was in part associated with inhibition of vascular endothelial growth factor receptor 3 (VEGFR-3) expression, as overexpression of VEGFR-3 conferred partial resistance to CPX inhibitory effect on tube formation in lymphatic endothelial cells (LECs), whereas downregulation of VEGFR-3 mimicked the effect of CPX, blocking the tube formation. Further study revealed that CPX did not alter mRNA level, but inhibited protein synthesis and promoted protein degradation of VEGFR-3. In addition, we found that CPX inhibited phosphorylation of the extracellular signal-related kinase 1/2 (ERK1/2), a downstream effector of VEGFR-3. Overexpression of VEGFR-3 attenuated CPX inhibition of ERK1/2 phosphorylation, whereas downregulation of VEGFR-3 inhibited extracellular signal-related kinase 1/2 (ERK1/2) phosphorylation in LECs. Ectopic expression of constitutively active mitogen -activated protein kinase kinase 1 (MKK1) resulted in activation of ERK1/2, and partially prevented CPX inhibition of LEC tube formation. The results suggest that CPX inhibits LEC tube formation at least in part through inhibiting VEGFR-3-mediated ERK signaling pathway.

Alterations in serum MMP-8, MMP-9, IL-12p40 and IL-23 in multiple sclerosis patients treated with interferon-β1b

Background: Interferon-β1b (IFN-β1b), an effective treatment for multiple sclerosis (MS), lessens disease severity in MS patients. However, the mechanisms of its immunoregulatory and anti-inflammatory effects in MS remain only partially understood. Matrix metalloproteinases (MMP) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are involved in blood brain barrier disruption and formation of MS lesions. Th1/Th17 cytokines e.g. interleukins IL-12p40, IL-17, and IL-23, are associated with MS disease activity and are significant players in pathogenesis of MS.

Objective: During a 1-year prospective study, we serially measured serum MMP-8, MMP-9, TIMP-1, IL-12p40, IL-17, and IL-23 in 24 patients with relapsing—remitting MS. We compared the results to clinical course and to brain magnetic resonance imaging. IFN-β1b decreased serum MMP-8 and MMP-9 (not TIMP-1).

Results: The sustained treatment with IFN-β1b attenuated the pro-inflammatory environment by significantly reducing the serum IL-12p40, IL-23, and showed a trend for decreasing IL-17. Decreased serum MMP-8, MMP-9, IL-12 and IL-23 levels were correlated with a decrease in the number of contrast-enhanced T2-weighted lesions.

Conclusion: Early treatment of MS with IFN-β1b may stabilize clinical disease by attenuating levels of inflammatory cytokines and MMPs. Serial measurement of inflammatory mediators may serve as sensitive markers to gauge therapeutic responses to IFN-β1b during the first year of treatment.

Blockage of angiotensin II type 1 receptor regulates TNF-alpha-induced MAdCAM-1 expression via inhibition of NF-kappaB translocation to the nucleus and ameliorates colitis

Mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1) is an important target in the treatment of inflammatory bowel disease (IBD). Recently, treatment of IBD with an antibody to alpha4beta7-integrin, a ligand for MAdCAM-1, has been an intense focus of research. Our aim was to clarify the mechanism by which MAdCAM-1 is regulated via angiotensin II type 1 receptor (AT1R), and to verify if AT1R might be a novel target for IBD treatment. The role of AT1R in the expression of MAdCAM-1 in SVEC (a murine high endothelial venule cell) and MJC-1 (a mouse colonic endothelial cell) was examined following cytokine stimulation. We further evaluated the effect of AT1R on the pathogenesis of immune-mediated colitis using AT1R-deficient (AT1R-/-) mice and a selective AT1R blocker. AT1R blocker significantly suppressed MAdCAM-1 expression induced by TNF-alpha, but did not inhibit phosphorylation of p38 MAPK or of IkappaB that modulate MAdCAM-1 expression. However, NF-kappaB translocation into the nucleus was inhibited by these treatments. In a murine colitis model induced by dextran sulfate sodium, the degree of colitis, judged by body weight loss, histological damage, and the disease activity index, was much milder in AT1R-/- than in wild-type mice. The expression of MAdCAM-1 was also significantly lower in AT1R-/- than in wild-type mice. These results suggest that AT1R regulates the expression of MAdCAM-1 under colonic inflammatory conditions through regulation of the translocation of NF-kappaB into the nucleus. Furthermore, inhibition of AT1R ameliorates colitis in a mouse colitis model. Therefore, AT1R might be one of new therapeutic target of IBD via regulation of MAdCAM-1.

Granzyme-b is involved in mediating post-ischemic neuronal death during focal cerebral ischemia in rat model

Although peripheral immune cells infiltrate ischemic infarct tissue and elicit immune injury, the role of Cytotoxic T Lymphocytes (CTLs) and the toxins they release in mediating neuronal death is not well understood. Granzyme-b (Gra-b), a serine protease found in the cytoplasmic granules of CTLs and natural killer cells, plays an important role in inducing target cell death by activating several caspases and by initiating caspase-independent pathways that contribute to target cell death. To determine if CTLs and Gra-b are involved in post-ischemic cerebral cell death; we investigated the role of CD8(+) CTLs and Gra-b in ischemic rat brain infarct after transient middle cerebral artery occlusion (tMCAO) and in sham-operated animals. We observed that CTLs infiltrate the ischemic infarct within 1 h of reperfusion. There was a significant increase in Gra-b levels in the ischemic region starting from 1 h until 3 day which correlated with increased levels of chemokines (IP-10/CXCL10, IL-2) and TNF-alpha. Co-immunoprecipitation experiments show that Gra-b interacts with Bid, PARP, and caspase-3 in ischemic samples. Immunofluorescence analysis of Gra-b and TUNEL showed that Gra-b is present both in apoptotic and necrotic cells. Triple immunostaining further confirmed that the Gra-b positive degenerating cells were neurons. CTLs in close spatial proximity to degenerating neurons, increased levels of Gra-b, localization in neurons positive for TUNEL, and interaction with other pro-apoptotic proteins indicate that Gra-b and CTLs play a significant role in neuronal death following cerebral ischemia in the rat brain after tMCAO. Based on the above findings we support our hypothesis that Gra-b secreted from activated CTLs might be involved in aggravating post-ischemic damage by mediating neuronal death.

Three-body dynamics in single ionization of atomic hydrogen by 75 keV proton impact

Doubly differential cross sections for single ionization of atomic hydrogen by 75 keV proton impact have been measured and calculated as a function of the projectile scattering angle and energy loss. This pure three-body collision system represents a fundamental test case for the study of the reaction dynamics in few-body systems. A comparison between theory and experiment reveals that three-body dynamics is important at all scattering angles and that an accurate description of the role of the projectile-target-nucleus interaction remains a major challenge to theory.

Interferon (IFN)-ß1a and IFN-ß1b Block IFN-?-Induced Disintegration of Endothelial Junction Integrity and Barrier

Recent clinical trials indicate the efficacy of interferon (IFN)-beta 1b in reducing relapse rate in relapsing-remitting multiple sclerosis (MS), whereas a surge of IFN-gamma precedes and provokes acute relapses. Disruption of the cerebral endothelial barrier and transendothelial migration of inflammatory cell migration into the brain play a significant role in pathogenesis of MS and may be driven by this surge in IFN-gamma. However, the molecular mechanisms underlying the beneficial effects of IFN-beta 1b against the deleterious effects of IFN-gamma on the barrier formed by the junctional proteins remain to be characterized. The authors investigated the effects of IFN-beta 1b, IFN-beta 1a, and IFN-gamma on the integrity of two endothelial junctional proteins, occludin and vascular endothelial-cadherin (VE-cadherin). Human umbilical vein endothelial cell (HUVEC) layers were treated with IFN-beta 1b, IFN-beta 1a, IFN-gamma, IFN-beta 1b plus IFN-gamma, or IFN-beta 1a plus IFN-gamma. IFN-beta 1b, IFN-beta 1a, and IFN-gamma effects on occludin and VE-cadherin integrity and electrical resistance were assessed by Western blotting and immunofluorescence. IFN-gamma significantly reduced occludin expression and produced gaps in endothelial monolayers. VE-cadherin expression was decreased to a lesser extent in endothelial cells exposed to IFN-gamma. IFN-beta 1b significantly attenuated the IFN-gamma-induced decrease in occludin and VE-cadherin expression. The protective effects of IFN-beta 1a on IFN-gamma-treated endothelial cells were similar to those of IFN-beta 1b. IFN-gamma also significantly reduced endothelial monolayer electrical resistance; this effect was blocked by either IFN-beta 1a or IFN-beta 1b. IFN-beta 1a and IFN-beta 1b effectively prevent the IFN-gamma-induced disintegration of the endothelial tight junctions and sustain barrier against the effects of IFN-gamma. The protective effects of IFN-beta on occludin and VE-cadherin stability appear to represent molecular mechanisms for the therapeutic effects of the IFN-beta on blood brain barrier in MS.

Effects of ammonium tetrathiomolybdate, an oncolytic/angiolytic drug on the viability and proliferation of endothelial and tumor cells

OBJECTIVE

This study examines the target specificity of tetrathiomolybdate (ATM), an anti-angiogenic, anti-tumor agent against the viability / proliferation of arterial, venous, capillary endothelial and tumor cells.

MATERIALS AND METHODS

Cells were seeded at 10 or 100% density (to measure viability / proliferation respectively) in medium +/- 0-250 uM ATM. Viability and proliferation were measured by metabolic labeling-colorimetry. One-way ANOVA + Bonferroni testing examined base metabolism; Dunnett's testing was used for viability/proliferation.

RESULTS

Venous proliferation showed high ATM sensitivity (50% reduction ~ > or =5 uM ATM, p<0.01), capillary proliferation was inhibited > or =10 uM (p<0.05). Arterial endothelium were less sensitive to ATM, (50% inhibition ~ > or = 20 uM, p<0.01). YPEN-1 were inhibited >50 uM ATM. Capillary viability was inhibited > or =20 microM ATM (p<0.01); venous, arterial and tumor viability show less ATM sensitivity.

CONCLUSIONS

Our data suggest that venous and capillary endothelial proliferation are important targets in ATM therapy, but that other vascular segments and tumor cells may be less influenced.

Contractility of placental vascular smooth muscle cells in response to stimuli produced by the placenta: roles of ACE vs. non-ACE and AT1 vs. AT2 in placental vessel cells

Our previously published work has shown that non-ACE angiotensin II (Ang II) generating system is dominate in the placenta and may play a critical role in regulation of placental vascular contractile function. In the present study, using a collagen gel contraction assay we further studied contractility of placental vascular smooth muscle cells (VSMCs) in response to factors produced by preeclamptic (PE) placentas. Placental VSMCs/type-1 collagen gels were incubated with PE placental conditioned medium in the presence or absence of inhibitors or receptor blockers. Captopril (an ACE inhibitor), chymostatin (a non-ACE chymase inhibitor), losartan (an AT1 receptor blocker) and PD123,319 (an AT2 receptor blocker) were used to study the specific ACE vs. non-ACE and AT1 vs. AT2 effects on placental VSMC contractility, respectively. Our results showed that chymostatin, but not captopril, and PD123,319, but not losartan, significantly attenuated placental VSMC/collagen gel contraction, p<0.01, respectively. The inhibitory effects of chymostatin and PD123,319 were dose-dependent. Our results suggest that chymase, a non-ACE Ang II generating enzyme, may contribute significantly to Ang II generated in the placenta vascular tissue and that the AT2 receptor may play an important role in the regulation of Ang II induced contractility of placental VSMCs. These results provide new insights into Ang II generation and Ang II receptor regulation of vessel contractile function in the placental vasculature. These results also suggest the potential role of increased chymase activity and altered AT2 receptor function in placental related pregnancy disorders such as preeclampsia and IUGR.

Increased Chymotrypsin-like Protease (chymase) Expression and Activity in Placentas from Women with Preeclampsia

Placenta-derived chymotrypsin-like protease (CLP/chymase) promotes endothelial P-selectin and E-selectin expression, which may be responsible for the increased neutrophil/endothelial interactions in preeclampsia (PE). However, little is known about this protease expression and production in human placenta. This study was undertaken to determine the distribution and gene expression of CLP in human placenta. Human placental tissues were obtained immediately after delivery from normal and PE pregnancies. We examined (1) CLP/chymase immunoactivity by immunohistochemical staining of villous tissue sections; (2) trophoblast mRNA and protein expression for chymase by RT-PCR and Western blot analysis; (3) chymase cDNA sequencing in isolated trophoblast cells (TCs); and (4) release of CLP by placental villous tissue cultured under 2% and 20% O(2). We found (1) CLP expression is mainly localized in the epithelial layer of syncytiotrophoblasts; (2) both mRNA and protein expression are significantly (p<0.05) upregulated in TCs isolated from PE vs. normal placentas; (3) TC chymase cDNA sequence and the deduced amino acid sequence are 100% identical to that reported for the human heart; and (4) villous tissue releases more chymotrypsin when cultured with 2% O(2). We conclude that (1) the DNA and protein sequence for chymase in placental trophoblast cells are the same as those reported in the human heart; (2) CLP/chymase expression is upregulated in TCs during PE; and (3) lowered oxygen condition promotes CLP release by placental TCs. Since chymase is a potent non-ACE angiotensin II producing enzyme, our data suggest that if placenta-derived CLP/chymase is released into the maternal circulation, it may contribute to the cardiovascular complications associated with PE.

Homogeneity of mesothelial cells with lymphatic endothelium: expression of lymphatic endothelial markers by mesothelial cells

BACKGROUND

Mesothelial cell monolayers cover the serous cavities and internal organs, and provide a protective low-friction interface between apposed organs and tissues. The mesothelium also regulates inflammation, fluid and cell exchange, and tissue repair in these compartments and possibly tumor metastasis. In the present study, a stable pleural mesothelial cell line (MIM) was isolated and characterized, and the expression of several lymphatic specific markers by these cells examined.

METHODS AND RESULTS

MIM were isolated from mice stably expressing a temperature-sensitive SV40 large T antigen ('Immortomouse', strain: H-2K(b)-tsA58). These cells were compared with lymphatic endothelial cells (LEC) derived from the mesenteric adventitia of the Immortomouse. MIM and LEC expression of lymphatic-specific markers (Flt-4, LYVE-1, and Prox-1) was examined, and the tight junction protein (ZO-1) was studied by immunofluorescence and immunoblotting in these cells.

RESULTS

LYVE-1, Prox-1, and Flt-4 were detected in both MIM and LEC, with Prox-1 and LYVE-1 more strongly expressed on LEC than MIM. Conversely, Flt-4 was more densely expressed on MIM than on LEC. Spatially, ZO-1 was prominent at MIM junctions, but was less well organized in LEC.

CONCLUSION

MIM and LEC share several characteristic markers usually associated with lymphatic endothelium. MIM might be useful for studying the biology and pathology of mesothelial cells in vitro and help in the development of therapies for mesothelial-related diseases, such as mesothelioma and pleural effusion.

Ifenprodil treatment is associated with a down-regulation of brain aquaporin 4 following cardiac arrest in rats

OBJECTIVES

Ifenprodil, a NMDA receptor polyamine site antagonist, reduces experimental cardiac arrest (CA)-elicited brain edema, which is associated with an up-regulation of aquaporin 4 (AQP4), a brain water-selective channel. However, the interacting roles of NMDA receptors and AQP4 in CA-elicited brain edema are unknown. The objective of this study was to test our hypothesis that ifenprodil treatment is associated with a down-regulation of brain AQP4.

METHODS

Twenty-five rats were assigned to normal controls (group 1, n = 6) or subjected to eight minutes of asphyxial CA treated with placebo (group 2, n = 9) or ifenprodil (group 3, n = 10). Ifenprodil at 10 mg/kg or normal saline of equal volume was given intraperitoneally, 5 minutes before CA. The density of AQP4 protein and actin bands was scanned and expressed as the ratios of the optical density of AQP4 relative to that of actin. The ANOVA analysis was used to compare the group differences.

RESULTS

The ratios of the optical density of AQP4 to that of actin were 0.88 +/- 0.06 in group 1, 1.11 +/- 0.08 in group 2 (p < 0.05 vs. group 1), and 0.78 +/- 0.04 in group 3 (p < 0.01 vs. group 2; NS vs. group 1).

CONCLUSION

Ifenprodil given before CA is associated with a downregulation of brain AQP4 in rats.

Isolation and Characterization of A Novel Mouse Lymphatic Endothelial Cell Line: SV-LEC

BACKGROUND

The lymphatic system regulates interstitial fluid and protein balance and modulates immune responses by regulating leukocyte and antigen traffic to lymph nodes. The present article describes a stable mouse lymphatic endothelial cell line from mesenteric adventitial tissue (SV-LEC) which is distinct from blood aortic (AEC) and venous (VEC) endothelial cells, based on expression of several lymphatic markers (e.g., Prox-1, LYVE-1, Flt-4). SV-LEC also expresses MAdCAM-1 in response to TNF-alpha, an effect seen in VEC, but not AEC.

METHODS AND RESULTS

Lymphatic endothelial cells (SV-LEC) were isolated from mesenteric adventitia from mice expressing temperature-sensitive SV40 large T ('Immortomouse', H-2K(b)tsA58) selected with hypoxia culture in D-valine-substituted MEM supplemented with VEGFC in a low oxygen atmosphere (0% O2, 5% CO2, and 95% N2) with 5 mM thioglycolate. Expression of lymphatic-specific markers (Flt-4, LYVE-1, Prox-1) and the tight junction proteins (ZO-1) were examined by RT-PCR, immunoblotting, and fluorescent microscopy. MAdCAM-1 (a high endothelial venular marker) expression was also examined in response to TNF-alpha IL-1beta and IFN-gamma.

RESULTS

Message for Flt-4 and LYVE-1 was detected on SV-LEC. Immunoblotting for LYVE-1 and Prox-1 showed strong expression on SV-LEC and VEC, but not AEC. Occludin expression was seen in all cell types, junctional ZO-1 was detected at SV-LEC and VEC junctions, not AEC.

CONCLUSION

SV-LEC expresses several lymphatic endothelial markers, some of which are shared with VEC, but not AEC, and may represent a useful system for modeling lymphatic function in vitro.

N-methyl-d-aspartate receptor activation in human cerebral endothelium promotes intracellular oxidant stress

Cerebral endothelial cells in the rat, pig, and, most recently, human have been shown to express several types of receptors specific for glutamate. High levels of glutamate disrupt the cerebral endothelial barrier via activation of N-methyl-d-aspartate (NMDA) receptors. We have previously suggested that this glutamate-induced barrier dysfunction was oxidant dependent. Here, we provide evidence that human cerebral endothelial cells respond to glutamate by generating an intracellular oxidant stress via NMDA receptor activation. Cerebral endothelial cells loaded with the oxidant-sensitive probe dihydrorhodamine were used to measure intracellular reactive oxygen species (ROS) formation in response to glutamate receptor agonists, antagonists, and second message blockers. Glutamate (1 mM) significantly increased ROS formation compared with sham controls (30 min). This ROS response was significantly reduced by 1) MK-801, a noncompetitive NMDA receptor antagonist; 2) 8-( N, N-diethylamino)- n-octyl-3,4,5-trimethoxybenzoate, an intracellular Ca2+antagonist; 3) LaCl3, an extracellular Ca2+channel blocker; 4) diphenyleiodonium, a heme-ferryl-containing protein inhibitor; 5) itraconazole, a cytochrome P-450 3A4 inhibitor; and 6) cyclosporine A, which prevents mitochondrial membrane pore transition required for mitochondrial-dependent ROS generation. Our results suggest that the cerebral endothelial barrier dysfunction seen in response to glutamate is Ca2+dependent and may require several intracellular signaling events mediated by oxidants derived from reduced nicotinamide adenine dinucleotide oxidase, cytochrome P-450, and the mitochondria.

MAdCAM-1 expression and regulation in murine colonic endothelial cells in vitro

BACKGROUND

Although the mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is associated with the etiology of inflammatory bowel diseases, few studies have directly examined MAdCAM-1 using microvascular endothelium derived from the colon. This study measured the expression of MAdCAM-1 in a novel colon endothelial line MJC-1, as well as MAdCAM-1 regulation and function in vitro.

METHODS

We cloned microvascular endothelial cells from primary colon cultures using ImmortoMice mice (whose cells express a temperature-sensitive SV40 large T antigen, H-2Kb-tsA58 mice). Expression of MAdCAM-1 after stimulation with cytokines [tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, or interferon (IFN)-gamma] was determined by Western blotting. Signal paths regulating MAdCAM-1 expression were examined using pharmacological blockers before cytokines. We also examined lymphocyte adhesion using lymphocytes that constitutively express alpha4beta7 integrin.

RESULTS

TNF-alpha induced MAdCAM-1 in a dose-dependent manner by 24 hours. MAdCAM-1 induction was protein kinase C, tyrosine kinase, p38 mitogen activated protein kinase, and nuclear-factor kappa-B/poly adenosine diphosphate ribose polymerase dependent. Lymphocyte adhesion was increased 2.6-fold after TNF-alpha stimulation and was inhibited by anti-MAdCAM-1 antibody before treatment (P < 0.05 control versus TNF-alpha).

CONCLUSIONS

In vitro, MAdCAM-1 can be induced on colon endothelial cells by TNF-alpha stimulation and may represent a useful model to study microvascular injury in the large intestine.

Cell column chromatography: a new research tool to quantify cerebral cell volume changes following chemically-induced anoxia/re-oxygenation

OBJECTIVE

The roles of individual types of cerebral cells in contributing to brain edema are undefined. The objective of this study was to determine the role of cerebral cell-column chromatography in quantifying cell volumes of individual cerebral cell lines, under chemically-induced anoxia/re-oxygenation (A/R).

METHODS

Cerebral endothelial cells (4 experiments) or type II astrocytes (4 experiments) were cultured to confluence on microcarrier beads. A chromatographic cell-column of 1.5 cm height was filled with non-treated cell-covered beads. The column was perfused at 1 ml/min with a balanced perfusate for one hour (Baseline). The perfusate was then switched to that containing 5 mM thioglycolic acid for one hour (Anoxia). Then the column was perfused with the normal perfusate for another two hours (Re-oxygenation). The total free space in the column, reversely reflecting cell volumes, was determined by averaged transit time (TTa) of a non-permeable flow tracer blue dextran. Decreased TTa means that cells swell, and vice versa.

RESULTS

TTa in endothelial cell columns increased with a peak at 60 minutes of re-oxygenation. TTa in astrocyte columns decreased with a nadir at 30 minutes of re-oxygenation.

CONCLUSION

Cell column chromatography can be used to determine the cerebral cell volume changes following chemically-induced anoxia/re-oxygenation.

Matrix metalloproteinases are not involved in early brain edema formation after cardiac arrest in rats

INTRODUCTION

Resuscitation from cardiac arrest (CA) often results in a poor neurological outcome possibly due to an incomplete understanding of the pathophysiology of brain injury following CA-induced global cerebral ischemia. Brain edema is an important manifestation after CA and is associated with significant morbidity and mortality. The matrix metalloproteinases (MMPs) contribute to brain edema formation following focal cerebral ischemia. The objective of this study was to investigate the role of an MMP inhibitor, GM6001, in CA-elicited brain edema.

METHODS

Eighteen rats were subjected to normothermic (37.5 +/- 0.5 degrees C) CA induced by eight minutes of asphyxiation and assigned to a CA-control group (CA), an alcohol-placebo group (CA + ETOH), or a GM6001-treated group (CA + GM6001). GM6001 in 100% alcohol or a vehicle was given i.v. before CA to achieve a whole blood concentration of 10 microM. Animals were resuscitated with CPR, ventilation and epinephrine. Brain edema was determined by brain wet-to-dry weight ratio at one hour after resuscitation.

FINDINGS

Brain wet-to-dry weight ratio was 4.86 +/- 0.09 in CA, 4.76 +/- 0.12 in CA + ETOH (p = 0.30 vs. CA), and 4.72 +/- 0.03 in CA + GM6001 (p = 0.17 vs. CA and 0.42 vs. CA + ETOH).

INTERPRETATION

MMPs are not involved in brain edema formation one hour following CA.

Glutamate causes a loss in human cerebral endothelial barrier integrity through activation of NMDA receptor

l-Glutamate is a major excitatory neurotransmitter that binds ionotropic and metabotropic glutamate receptors. Cerebral endothelial cells from many species have been shown to express several forms of glutamate receptors; however, human cerebral endothelial cells have not been shown to express either the N-methyl-D-aspartate (NMDA) receptor message or protein. This study provides evidence that human cerebral endothelial cells express the message and protein for NMDA receptors. Human cerebral endothelial cell monolayer electrical resistance changes in response to glutamate receptor agonists, antagonists, and second message blockers were tested. RT-PCR and Western blot analysis were used to demonstrate the presence of the NMDA receptor. Glutamate and NMDA (1 mM) caused a significant decrease in electrical resistance compared with sham control at 2 h postexposure; this response could be blocked significantly by MK-801 (an NMDA antagonist), 8-(N,N-diethylamino)-n-octyl-3,4,5-trimethyoxybenzoate (an intracellular Ca2+ antagonist), and N-acetyl-L-cystein (an antioxidant). Trans(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid, a metabotropic receptor agonist (1 mM), did not significantly decrease electrical resistance. Our results are consistent with a model where glutamate, at excitotoxic levels, may lead to a breakdown in the blood brain barrier via activation of NMDA receptors.

Human neuroepithelial cells express NMDA receptors

L-glutamate, an excitatory neurotransmitter, binds to both ionotropic and metabotropic glutamate receptors. In certain parts of the brain the BBB contains two normally impermeable barriers: 1) cerebral endothelial barrier and 2) cerebral epithelial barrier. Human cerebral endothelial cells express NMDA receptors; however, to date, human cerebral epithelial cells (neuroepithelial cells) have not been shown to express NMDA receptor message or protein. In this study, human hypothalamic sections were examined for NMDA receptors (NMDAR) expression via immunohistochemistry and murine neuroepithelial cell line (V1) were examined for NMDAR via RT-PCR and Western analysis. We found that human cerebral epithelium express protein and cultured mouse neuroepithelial cells express both mRNA and protein for the NMDA receptor. These findings may have important consequences for neuroepithelial responses during excitotoxicity and in disease.

Protease chymotrypsin mediates the endothelial expression of P- and E-selectin, but not ICAM and VCAM, induced by placental trophoblasts from pre-eclamptic pregnancies

OBJECTIVES

Soluble endothelial-cell adhesion molecules (ICAM, VCAM and PECAM) are markers of endothelial activation, and are elevated in the maternal circulation during pregnancy and even further increased in pregnancies complicated by pre-eclampsia (PE). To identify possible sources of endothelial activators during pregnancy, we addressed whether factors released from placental trophoblast cells (TCs) activate endothelial cells (ECs) to enhance adhesion molecule expression on ECs. We also examined whether proteases released by placental cells induce the endothelial cell surface molecule expression in PE.

METHODS

Confluent ECs were co-cultured with placental TCs derived from normal (n=9) or PE (n=8) pregnancies or with placental conditioned media (CM) derived from PE placental cultures (n=7). ICAM, VCAM, P-selectin and E-selectin were quantified using an enzyme-linked immunosorbent assay (ELISA). The protease inhibitors alpha(2)-macroglobulin (alpha(2)M), thrombin inhibitor (TI) and chymotrypsin inhibitor (CI) were tested in the co-culture system. mRNAs for ICAM, VCAM, P-selectin and E-selectin were determined by RNase protection assay (RPA). NF-kappaB activity in ECs was also determined.

RESULTS

(1) ICAM and VCAM expression was significantly increased on ECs co-cultured with both normal-TCs and PE-TCs, compared to control ECs (P<0.01). ICAM and VCAM expression in ECs co-cultured with normal-TCs did not differ from ECs co-cultured with PE-TCs. (2) E-selectin expression was increased on ECs co-cultured with normal-TCs (P<0.05) and further increased in ECs co-cultured with PE-TCs (P<0.01). (3) P-selectin expression was increased on ECs co-cultured with PE-TCs, but not ECs co-cultured with normal-TCs compared to control ECs (P<0.05). (4) alpha(2)M and TI did not alter the ICAM, VCAM, P-selectin and E-selectin expression on ECs induced by PE-CM. (5) CI blocked the upregulation of P-selectin and E-selectin (P<0.05), but not ICAM and VCAM expression, in ECs cultured with PE-CM. (6) Changes in mRNA for ICAM, VCAM, P-selectin and E-selectin paralleled the increases in protein expression on ECs cultured with PE-CM. (7) NF-kappaB activity was also increased in cells challenged with PE-CM.

CONCLUSIONS

(1) Factor(s) released from both normal-TCs and PE-TCs promote ICAM and VCAM expression on ECs. (2) Factor(s) released from PE-TCs significantly increase EC P-selectin and E-selectin expression. (3) CI blocks the upregulation of P-selectin and E-selectin on ECs induced by factors released from PE placental cells, suggesting that chymotrypsin is responsible for the increased endothelial expression of P-selectin and E-selectin in pre-eclampsia.

The protective effect of rebamipide on paracellular permeability of rat gastric epithelial cells

BACKGROUND

Barrier function in gastric epithelial cells is essential for the gastric defence mechanism against acid back-diffusion into the mucosal layer. Our previous study indicated that trans-epithelial resistance (TER) of rat gastric epithelial cells was rapidly increased when the cells were exposed to acid. This response to acid was diminished by indometacin.

AIM

Evaluate the effects of a mucoprotective agent, rebamipide, on the nonsteroidal anti-inflammatory drug (NSAID)-induced increase of gastric epithelial permeability.

METHODS

Rat gastric epithelial cells were plated on tissue culture inserts. Cells were exposed to a NSAID (indometacin, 10-7 M). Trans-epithelial permeability was measured by TER and diffusion rate of 14C-mannitol. The effect of rebamipide was evaluated by measuring TER. Endogenous prostaglandin E2 (PGE2) production in culture medium was also measured.

RESULTS

Indometacin gradually and significantly decreased TER and increased 14C-manitol permeability. Rebamipide reversed the indometacin-induced changes in epithelial permeability and induced PGE2 synthesis. This induction was blocked by either indometacin or a Cyclooxygenase (COX)-2 specific inhibitor.

CONCLUSIONS

COX inhibitors such as indometacin inhibit regulation of epithelial permeability by reducing PGE2. COX-1 has an important role in the gastric defense mechanism. Rebamipide suppressed an indometacin-induced increase in gastric epithelial permeability by increasing PGE2 levels in a COX-2 dependent manner.

Expression of junctional proteins in human platelets

Platelets play a major role in thrombosis and hemostasis by binding the sub-endothelial matrix at sites of injury, but also participate in vascular pathologies such as atherosclerosis. Recently, junctional proteins like PECAM-I and JAM-family members have been recovered from platelets, therefore we examined what other junctional molecules may be present in platelets. We observed immunoreactivity for APC (147 kD), beta-catenin (92 kD), E-cadherin (120 and 84 kD) and occludin (70-85 kD) by western blotting. Additionally, beta-catenin, pan-reactive cadherins, E-cadherin and occludin were seen to partition with the triton insoluble cytoskeleton in platelets. These proteins were also found in a megakaryocyte (platelet precursor) line, MEG-01. Our data suggest that conventional junctional molecules are expressed in platelets and could possibly participate in aggregation, clot formation and wound healing.

TNF-alpha -induced endothelial cell adhesion molecule expression is cytochrome P-450 monooxygenase dependent

It is strongly suspected that cytokine-induced gene expression in inflammation is oxidant mediated; however, the intracellular sources of signaling oxidants remain controversial. In inflammatory bowel disease (IBD) proinflammatory cytokines, such as TNF-alpha, trigger gene expression of endothelial adhesion molecules including mucosal addressin cell adhesion molecule-1 (MAdCAM-1). MAdCAM-1 plays an essential role in gut inflammation by governing the infiltration of leukocytes into the intestine. Several groups suggest that endothelial-derived reduced NADP (NADPH) oxidase produces signaling oxidants that control the expression of adhesion molecules (E-selectin, ICAM-1, VCAM-1). In addition to NADPH oxidase, cytochrome P-450 (CYP450) monooxygenases have also been shown to trigger cytokine responses. We found that in high endothelial venular cells (SVEC4-10), multiple inhibitors of CYP450 monooxygenases (SKF-525a, ketoconazole, troleandomycin, itraconazole) attenuated TNF-alpha induction of MAdCAM-1, whereas NADPH oxidase inhibition (PR-39) did not. Conversely, E-selectin, ICAM-1, and VCAM-1 induction requires both NADPH oxidase and CYP450-derived oxidants. We show here that MAdCAM-1 induction may depend exclusively on CYP450-derived oxidants, suggesting that CYP450 blockers might represent a possible novel therapeutic treatment for human IBD.

Extracellular matrix, junctional integrity and matrix metalloproteinase interactions in endothelial permeability regulation

Vascular endothelial permeability is maintained by the regulated apposition of adherens and tight junctional proteins whose organization is controlled by several pharmacological and physiological mediators. Endothelial permeability changes are associated with: (1) the spatial redistribution of surface cadherins and occludin, (2) stabilization of focal adhesive bonds and (3) the progressive activation of matrix metalloproteinases (MMPs). In response to peroxide, histamine and EDTA, endothelial cells sequester VE-cadherin and alter its cytoskeletal binding. Simultaneously, these mediators enhance focal adhesion to the substratum. Oxidants, cytokines and pharmacological mediators also trigger the activation of matrix metalloproteinases (MMPs) in a cytoskeleton and tyrosine phosphorylation dependent manner to degrade occludin, a well-characterized tight junction element. These related in vitro phenomena appear to co-operate during inflammation, to increase endothelial permeability, structurally stabilize cells while also remodelling cell junctions and substratum.