Gastric supply manipulation to modulate ghrelin production and enhance vascularization to the cardia: proof of the concept in a porcine model.

Introduction. Selective embolization of the left-gastric artery (LGA) reduces levels of ghrelin and achieves significant short-term weight loss. However, embolization of the LGA would prevent the performance of bariatric procedures because the high-risk leakage area (gastroesophageal junction [GEJ]) would be devascularized. Aim. To assess an alternative vascular approach to the modulation of ghrelin levels and generate a blood flow manipulation, consequently increasing the vascular supply to the GEJ. Materials and methods. A total of 6 pigs underwent a laparoscopic clipping of the left gastroepiploic artery. Preoperative and postoperative CT angiographies were performed. Ghrelin levels were assessed perioperatively and then once per week for 3 weeks. Reactive oxygen species (ROS; expressed as ROS/mg of dry weight [DW]), mitochondria respiratory rate, and capillary lactates were assessed before and 1 hour after clipping (T0 and T1) and after 3 weeks of survival (T2), on seromuscular biopsies. A celiac trunk angiography was performed at 3 weeks. Results. Mean (±standard deviation) ghrelin levels were significantly reduced 1 hour after clipping (1902 ± 307.8 pg/mL vs 1084 ± 680.0; P = .04) and at 3 weeks (954.5 ± 473.2 pg/mL; P = .01). Mean ROS levels were statistically significantly decreased at the cardia at T2 when compared with T0 (0.018 ± 0.006 mg/DW vs 0.02957 ± 0.0096 mg/DW; P = .01) and T1 (0.0376 ± 0.008mg/DW; P = .007). Capillary lactates were significantly decreased after 3 weeks, and the mitochondria respiratory rate remained constant over time at the cardia and pylorus, showing significant regional differences. Conclusions. Manipulation of the gastric flow targeting the gastroepiploic arcade induces ghrelin reduction. An endovascular approach is currently under evaluation.

Pkd1 Regulates Lymphatic Vascular Morphogenesis during Development.

Lymphatic vessels arise during development through sprouting of precursor cells from veins, which is regulated by known signaling and transcriptional mechanisms. The ongoing elaboration of vessels to form a network is less well understood. This involves cell polarization, coordinated migration, adhesion, mixing, regression, and shape rearrangements. We identified a zebrafish mutant, lymphatic and cardiac defects 1 (lyc1), with reduced lymphatic vessel development. A mutation in polycystic kidney disease 1a was responsible for the phenotype. PKD1 is the most frequently mutated gene in autosomal dominant polycystic kidney disease (ADPKD). Initial lymphatic precursor sprouting is normal in lyc1 mutants, but ongoing migration fails. Loss of Pkd1 in mice has no effect on precursor sprouting but leads to failed morphogenesis of the subcutaneous lymphatic network. Individual lymphatic endothelial cells display defective polarity, elongation, and adherens junctions. This work identifies a highly selective and unexpected role for Pkd1 in lymphatic vessel morphogenesis during development.

Targeting B-cell lymphomas with inhibitors of the MALT1 paracaspase.

The paracaspase MALT1 is an Arg-specific protease that cleaves multiple substrates to promote lymphocyte proliferation and survival. The catalytic activity of MALT1 is normally tightly regulated by antigen receptor triggering, which promotes MALT1 activation by its inducible monoubiquitination-dependent dimerization. Constitutive MALT1 activity is a hallmark of specific subsets of B-cell lymphomas, which are characterized by chromosomal translocations or point mutations that activate MALT1 or its upstream regulators. Recent findings suggest that such lymphomas may be sensitive to treatment with MALT1 inhibitors. Here we review recent progress in the understanding of MALT1 function and regulation, and the development of small molecule MALT1 inhibitors for therapeutic applications.

Targeting burn prevention in the paediatric population : a prospective study of children's burns in the Lausanne area.

QUESTION UNDER STUDY: Domestic accidents are an important problem in paediatric medicine. This study was designed to gain a better understanding of burn mechanisms and target prevention. METHODS: Children treated for burn lesions in the Department of Paediatric Surgery between August 2004 and August 2005 were included in this prospective study. The burn mechanisms, the children's ages and the circumstances in which children were burned as well as their home environment variables were analyzed. RESULTS: The current study included eighty-nine patients, aged between 2 months and 15 years. Seventy-eight percent were less than 5 years old. More than half were boys. Hot liquid scalding was the most frequent mechanism. There does not seem to be an increased risk in the immigrant population or in low economic status families. In most cases, an adult person was present at time of injury. CONCLUSIONS: If we were to describe the highest "at risk" candidate for a burn in our region, it would be a boy aged 15 months to 5 years who is burned by a cup of hot liquid on his hand, at home, around mealtime, in the presence of one or both parents. Reduced attention in the safe domestic setting is probably responsible.

Vascular dysfunction in children conceived by assisted reproductive technologies: underlying mechanisms and future implications.

Epidemiological studies in humans have demonstrated a relationship between pathological events during fetal development and increased cardiovascular risk later in life and have led to the so called "Fetal programming of cardiovascular disease hypothesis". The recent observation of generalised vascular dysfunction in young apparently healthy children conceived by assisted reproductive technologies (ART) provides a novel and potentially very important example of this hypothesis. This review summarises recent data in ART children demonstrating premature subclinical atherosclerosis in the systemic circulation and pulmonary vascular dysfunction predisposing to exaggerated hypoxia-induced pulmonary hypertension. These problems appear to be related to the ART procedure per se. Studies in ART mice demonstrating premature vascular aging and arterial hypertension further demonstrate the potential of ART to increase cardiovascular risk and have allowed to unravel epigenetic alterations of the eNOS gene as an underpinning mechanism. The roughly 25% shortening of the life span in ART mice challenged with a western style high-fat-diet demonstrates the potential importance of these alterations for the long-term outcome. Given the young age of the ART population, data on cardiovascular endpoints will not be available before 20 to 30 years from now. However, already now cohort studies of the ART population are needed to early detect cardiovascular alterations with the aim to prevent or at least optimally treat cardiovascular complications. Finally, a debate needs to be engaged on the future of ART and the consequences of its exponential growth for public health.

Targeting intratumoral B cells with rituximab in addition to CHOP in angioimmunoblastic T-cell lymphoma. A clinicobiological study of the GELA.

Background In angioimmunoblastic T-cell lymphoma, symptoms linked to B-lymphocyte activation are common, and variable numbers of CD20(+) large B-blasts, often infected by Epstein-Barr virus, are found in tumor tissues. We postulated that the disruption of putative B-T interactions and/or depletion of the Epstein-Barr virus reservoir by an anti-CD20 monoclonal antibody (rituximab) could improve the clinical outcome produced by conventional chemotherapy. DESIGN AND METHODS: Twenty-five newly diagnosed patients were treated, in a phase II study, with eight cycles of rituximab + chemotherapy (R-CHOP21). Tumor infiltration, B-blasts and Epstein-Barr virus status in tumor tissue and peripheral blood were fully characterized at diagnosis and were correlated with clinical outcome. RESULTS: A complete response rate of 44% (95% CI, 24% to 65%) was observed. With a median follow-up of 24 months, the 2-year progression-free survival rate was 42% (95% CI, 22% to 61%) and overall survival rate was 62% (95% CI, 40% to 78%). The presence of Epstein-Barr virus DNA in peripheral blood mononuclear cells (14/21 patients) correlated with Epstein-Barr virus score in lymph nodes (P<0.004) and the detection of circulating tumor cells (P=0.0019). Despite peripheral Epstein-Barr virus clearance after treatment, the viral load at diagnosis (>100 copy/μg DNA) was associated with shorter progression-free survival (P=0.06). Conclusions We report here the results of the first clinical trial targeting both the neoplastic T cells and the microenvironment-associated CD20(+) B lymphocytes in angioimmunoblastic T-cell lymphoma, showing no clear benefit of adding rituximab to conventional chemotherapy. A strong relationship, not previously described, between circulating Epstein-Barr virus and circulating tumor cells is highlighted.

Endogenous cannabinoid receptor CB1 activation promotes vascular smooth-muscle cell proliferation and neointima formation.

Percutaneous transluminal angioplasty is frequently used in patients with severe arterial narrowing due to atherosclerosis. However, it induces severe arterial injury and an inflammatory response leading to restenosis. Here, we studied a potential activation of the endocannabinoid system and the effect of FA amide hydrolase (FAAH) deficiency, the major enzyme responsible for endocannabinoid anandamide degradation, in arterial injury. We performed carotid balloon injury in atherosclerosis-prone apoE knockout (apoE(-/-)) and apoE(-/-)FAAH(-/-) mice. Anandamide levels were systemically elevated in apoE(-/-) mice after balloon injury. ApoE(-/-)FAAH(-/-) mice had significantly higher baseline anandamide levels and enhanced neointima formation compared with apoE(-/-) controls. The latter effect was inhibited by treatment with CB1 antagonist AM281. Similarly, apoE(-/-) mice treated with AM281 had reduced neointimal areas, reduced lesional vascular smooth-muscle cell (SMC) content, and proliferating cell counts. The lesional macrophage content was unchanged. In vitro proliferation rates were significantly reduced in CB1(-/-) SMCs or when treating apoE(-/-) or apoE(-/-)FAAH(-/-) SMCs with AM281. Macrophage in vitro adhesion and migration were marginally affected by CB1 deficiency. Reendothelialization was not inhibited by treatment with AM281. In conclusion, endogenous CB1 activation contributes to vascular SMC proliferation and neointima formation in response to arterial injury.

Interhemispheric distribution of Alzheimer disease and vascular pathology in brain aging

BACKGROUND AND PURPOSE: Most of the neuropathological studies in brain aging were based on the assumption of a symmetrical right-left hemisphere distribution of both Alzheimer disease and vascular pathology. To explore the impact of asymmetrical lesion formation on cognition, we performed a clinicopathological analysis of 153 cases with mixed pathology except macroinfarcts. METHODS: Cognitive status was assessed prospectively using the Clinical Dementia Rating scale; neuropathological evaluation included assessment of Braak neurofibrillary tangle and Ass deposition staging, microvascular pathology, and lacunes. The right-left hemisphere differences in neuropathological scores were evaluated using the Wilcoxon signed rank test. The relationship between the interhemispheric distribution of lesions and Clinical Dementia Rating scores was assessed using ordered logistic regression. RESULTS: Unlike Braak neurofibrillary tangle and Ass deposition staging, vascular scores were significantly higher in the left hemisphere for all Clinical Dementia Rating scores. A negative relationship was found between Braak neurofibrillary tangle, but not Ass staging, and vascular scores in cases with moderate to severe dementia. In both hemispheres, Braak neurofibrillary tangle staging was the main determinant of cognitive decline followed by vascular scores and Ass deposition staging. The concomitant predominance of Alzheimer disease and vascular pathology in the right hemisphere was associated with significantly higher Clinical Dementia Rating scores. CONCLUSIONS: Our data show that the cognitive impact of Alzheimer disease and vascular lesions in mixed cases may be assessed unilaterally without major information loss. However, interhemispheric differences and, in particular, increased vascular and Alzheimer disease burden in the right hemisphere may increase the risk for dementia in this group.

Specific targeting of pro-death NMDA receptor signals with differing reliance on the NR2B PDZ ligand.

NMDA receptors (NMDARs) mediate ischemic brain damage, for which interactions between the C termini of NR2 subunits and PDZ domain proteins within the NMDAR signaling complex (NSC) are emerging therapeutic targets. However, expression of NMDARs in a non-neuronal context, lacking many NSC components, can still induce cell death. Moreover, it is unclear whether targeting the NSC will impair NMDAR-dependent prosurvival and plasticity signaling. We show that the NMDAR can promote death signaling independently of the NR2 PDZ ligand, when expressed in non-neuronal cells lacking PSD-95 and neuronal nitric oxide synthase (nNOS), key PDZ proteins that mediate neuronal NMDAR excitotoxicity. However, in a non-neuronal context, the NMDAR promotes cell death solely via c-Jun N-terminal protein kinase (JNK), whereas NMDAR-dependent cortical neuronal death is promoted by both JNK and p38. NMDAR-dependent pro-death signaling via p38 relies on neuronal context, although death signaling by JNK, triggered by mitochondrial reactive oxygen species production, does not. NMDAR-dependent p38 activation in neurons is triggered by submembranous Ca(2+), and is disrupted by NOS inhibitors and also a peptide mimicking the NR2B PDZ ligand (TAT-NR2B9c). TAT-NR2B9c reduced excitotoxic neuronal death and p38-mediated ischemic damage, without impairing an NMDAR-dependent plasticity model or prosurvival signaling to CREB or Akt. TAT-NR2B9c did not inhibit JNK activation, and synergized with JNK inhibitors to ameliorate severe excitotoxic neuronal loss in vitro and ischemic cortical damage in vivo. Thus, NMDAR-activated signals comprise pro-death pathways with differing requirements for PDZ protein interactions. These signals are amenable to selective inhibition, while sparing synaptic plasticity and prosurvival signaling.

Targeting the undruggable: immunotherapy meets personalized oncology in the genomic era.

Owing to recent advances in genomic technologies, personalized oncology is poised to fundamentally alter cancer therapy. In this paradigm, the mutational and transcriptional profiles of tumors are assessed, and personalized treatments are designed based on the specific molecular abnormalities relevant to each patient's cancer. To date, such approaches have yielded impressive clinical responses in some patients. However, a major limitation of this strategy has also been revealed: the vast majority of tumor mutations are not targetable by current pharmacological approaches. Immunotherapy offers a promising alternative to exploit tumor mutations as targets for clinical intervention. Mutated proteins can give rise to novel antigens (called neoantigens) that are recognized with high specificity by patient T cells. Indeed, neoantigen-specific T cells have been shown to underlie clinical responses to many standard treatments and immunotherapeutic interventions. Moreover, studies in mouse models targeting neoantigens, and early results from clinical trials, have established proof of concept for personalized immunotherapies targeting next-generation sequencing identified neoantigens. Here, we review basic immunological principles related to T-cell recognition of neoantigens, and we examine recent studies that use genomic data to design personalized immunotherapies. We discuss the opportunities and challenges that lie ahead on the road to improving patient outcomes by incorporating immunotherapy into the paradigm of personalized oncology.

Expression and function of endothelin and its receptors in vascular adventitial fibroblasts

Objective: The adventitia has been recognized to play important roles in vascular oxidative stress, remodelling and contraction. We recently demonstrated that adventitial fibroblasts are able to express endothelin-1 (ET-1) in response to angiotensin II (ANG II). However, the mechanisms by which ANG II induces ET-1 expression are unknown. It is also unclear whether the ET-1 receptors are expressed in the adventitia. We therefore examined the role of oxidative stress in the regulation of ET-1. We also investigated the expression of both the ETA and ETB receptors and the roles of these two types of receptors in collagen synthesis and ET-1 clearance in adventitial fibroblasts. Methods and Results: Adventitial fibroblasts were isolated and cultured from the thoracic mouse aorta. Cells were treated with ANG II (lOOnM), ET-1 (lOpM), NADPH oxidase inhibitor apocynin (lOOfiM), the superoxide anion scavenger tempol (lOOfiM), the ANG II receptor antagonists (100[aM), losartan (AT| receptor) and PD 1233 19 (AT2 receptor), the ET-1 receptor antagonists (lOOuM), BQ123 (ETA receptor) and BQ788 (ETB receptor), and the ETB receptor agonist (lOOnM) Sarafotoxin 6C. ET-1 peptide levels were determined by ELISA, while ETA ,ETB and collagen levels were determined by Western blot. ANG II increased ET-1 peptide levels in a time-dependent manner reaching significance when incubated for 24 hours. NAD(P)H oxidase inhibitor, apocynin, as well as the superoxide scanverger, tempol, significantly reduced ANG Il-induced ET-1 peptide levels while over-expression of SOD1 (endogenous antioxidant enzyme) significantly decreased ANG Il-induced collagen I expression, therefore implicating reactive oxygen species in the mediation of ET-1. ANG II increased ETA receptor protein as well as collagen in a similar fashion, reaching significance after 4, 6, and 24 hours treatment. ANG II induced collagen was reduced while in the presence of the ETA receptor antagonist suggesting the role of the ETa receptor in the regulation of the extracellular matrix. ANG II treatment also increased ETB receptor protein levels in a time-dependent manner. ANG II treatment in the presence of the ETB receptor antagonist significantly increased ET-1 peptide levels. On another hand, the ETB receptor agonist, Sarafotoxin 6C, significantly decreased ET-1 peptide levels. These data implicate the role of the ETb receptor in the clearance of the ET-1 peptide. Conclusion: ANG II-induced increases of ET-1 peptide appears to be mediated by reactive oxygen species derived from NAD(P)H oxidase. Both the ETA and ETB receptors are expressed in adventitial fibroblasts. The ETA receptor subtype mediates collagen I expression, while the ETB receptor may play a protective role through increasing the clearance of the ET- 1 peptide.

Mechanisms of endothelin-1 induced reactive oxygen species production in vascular adventitial fibroblasts

With the relationship between endothelin-1 (ET-1) stimulation and reactive oxygen species (ROS) production unknown in adventitial fibroblasts, I examined the ROS response to ET-1 and angiotensin (Ang II). ET-1 -induced ROS peaked following 4 hrs of ET-1 stimulation and was inhibited by an ETA receptor antagonist (BQ 123, 1 uM) an extracellular signal-regulated kinase (ERK) 1/2 inhibitor (PD98059, 10 uM), and by both a specific, apocynin (10 uM), and non-specific, diphenyleneiodonium (10 uM), NAD(P)H oxidase inhibitor. NOX2 knockout fibroblasts did not produce an ET-1 induced change in ROS levels. Ang II treatment increased ROS levels in a biphasic manner, with the second peak occurring 6 hrs following stimulation. The secondary phase of Ang II induced ROS was inhibited by an ATi receptor antagonist, Losartan (100 uM) and BQ 123. In conclusion, ET-1 induces ROS production primarily through an ETA-ERKl/2 NOX2 pathway, additionally, Ang II-induced ROS production also involves an ETa pathway.

The roles of ERK1/2 and PI3K in abnormal vascular functions in angiotensin II-infused hypertensive rats

Background: Ang II plays a major role in cardiovascular regulation. Recently, it has become apparent that vascular superoxide anion may play an important role in hypertension development. Treatment with antisense NAD(P)H oxidase or SOD decreased BP in Ang II-infused rats. Wang et al recently reported mice which lack one of the subunits of NAD(P)H oxidase developed hypertension at a much lower extent when compared to the wild type animals infused with Ang II, indicating that superoxide anion contributes to elevation in BP in the Ang II-infused hypertensive model. In the Ang II-infused hypertensive model, altered reactivity of blood vessels is often associated with the elevation of systolic blood pressure. We have observed abnormal tension development and impaired endothelium-dependent relaxation in the isolated aorta of Ang II-infused and DOCA-salt hypertensive rats. Recently, several other cellular signal molecules, including ERK1I2 and PI3K, have been determined to play important roles in the regulation of smooth muscle contraction and relaxation. ERKl/2 and PI3K pathways are also reported to contribute to Ang II induced cell growth, hypertrophy, remodeling and contraction. Moreover, these signaling pathways have shown ROS-sensitive properties. Therefore, the aim of the present study is to investigate the roles of ERKl12 and PI3K in vascular oxidative stress, spontaneous tone and impaired endothelium relaxation in Ang II-infused hypertensive model. Hypothesis: We hypothesize that the activation of ERKl12 and PI3K are elevated in response to an Ang II infusion for 6 days. The elevated activation of phospho-ERKl/2 and PI3K mediated the increased level of vascular superoxide anion, the abnormal vascular contraction and impaired endothelium-dependent vascular relaxation in Ang II-infused hypertensive rats. Methods: Vascular superoxide anion level is measured by lucigenin chemiluminescence. Spontaneous tone and ACh-induced endothelium-dependent relaxation was measured by isometric tension recording in organ chamber. The activity of ERK pathway will be measured by its Western blot of phosphorylation of ERK. PI3K activity was evaluated indirectly by Western blot of the phosphorylation of PDKl, a downstream protein of PI3K signaling pathway. The role of each pathway was also addressed via comparing the responses to the specific inhibitors. Results: Superoxide anion was markedly increased in the isolated thoracic aorta from Ang II-infused rats. There was spontaneous tone developed in rings from Ang II-induced hypertensive but not sham-operated normotensive rats. ACh-induced endothelium-dependent relaxation function is impaired in Ang II-infused hypertensive rats. Superoxide dismutase and NAD(P)H oxidase inhibitor, apocynin, inhibited the abnormal spontaneous tone and ameliorated impaired endothelium-dependent relaxation. The expression of phopho-ERKII2 was enhanced in Ang II-infused rats, indicating the activity of ERK1I2 could be increased. MEK1I2 inhibitors, PD98059 and U126, but not their inactive analogues, SB203580 and U124, significantly reduced the vascular superoxide anion in aortas from Ang II-infused rats. The MEK1I2 inhibitors reduced the spontaneous tone and improved the impaired endothelium-dependent relaxation in aorta of hypertension. These findings supported the role of ERKII2 signaling pathway in vascular oxidative stress, spontaneous tone and impaired endothelium-dependent relaxation in Ang II-infused hypertensive rats. The amount of phospho-PDK, a downstream protein of PI3K was increased in Ang II rats indicating the activity of PI3K activity was elevated. Strikingly, PI3K significantly inhibited the increase of superoxide anion level, abnormal spontaneous tone and restored endothelium-dependent relaxation in Ang II-infused hypertensive rats. These findings indicated the important role of PI3K in Ang II-infused hypertensive rats. Conclusion: ERKII2 and PI3K signaling pathways are sustained activated in Ang II-infused hypertensive rats. The activated ERKII2 and PI3K mediate the increase of vascular superoxide anion level, vascular abnormal spontaneous tone and impaired endothelium-dependent relaxation.

The association between blood pressure and vascular characteristics in children

Hypertension is thought to exist in up to five percent of children. A select number of studies have investigated the role elevated blood pressure plays in pediatric atherosclerotic progression. However these studies contain significant methodological flaws and fail to recognize important confounding factors. Therefore, the influence of elevated blood pressure on arterial health in children remains to be clearly understood. The purpose of this study was to investigate the association between blood pressure (BP) and arterial thickness and stiffuess in children. Common carotid artery (CCA) intima-media thickness (IMT) and distensibility (Dist), as well as systemic pulse wave velocity (PWV) were measured in 21 elevated blood pressure (EBP; BP ~ 95th percentile) and 83 normal blood pressure (NBP; BP < 90th percentile) children 11-14 years of age. Both EBP and NBP groups demonstrated BP within the normal clinical range, but EBP showed significantly elevated BP as compared to the NBP group. Independent t-tests failed to show significant differences between the EBP and NBP groups for CCA IMT (0.43 ± 0.05 mm and 0.42 ± 0.06 mm, respectively) and Dist (0.0058 ± 0.0024 mmHg-1 and 0.0064 ± 0.0019 mmHil respectively). In contrast, a significantly elevated PWV (p