Regulation of vasculogenesis and angiogenesis by EphB/ephrin-B2 signaling between endothelial cells and surrounding mesenchymal cells

Although the cellular and molecular mechanisms governing angiogenesis are only beginning to be understood, signaling through endothelial-restricted receptors, particularly receptor tyrosine kinases, has been shown to play a pivotal role in these events. Recent reports show that EphB receptor tyrosine kinases and their transmembrane-type ephrin-B2 ligands play essential roles in the embryonic vasculature. These studies suggest that cell-to-cell repellent effects due to bidirectional EphB/ephrin-B2 signaling may be crucial for vascular development, similar to the mechanism described for neuronal development. To test this hypothesis, we disrupted the precise expression pattern of EphB/ephrin-B2 in vivo by generating transgenic (CAGp-ephrin-B2 Tg) mice that express ephrin-B2 under the control of a ubiquitous and constitutive promoter, CMV enhancer-beta-actin promoter-beta-globin splicing acceptor (CAG). These mice displayed an abnormal segmental arrangement of intersomitic vessels, while such anomalies were not observed in Tie-2p-ephrin-B2 Tg mice in which ephrin-B2 was overexpressed in only vascular endothelial cells (ECs). This finding suggests that non-ECs expressing ephrin-B2 alter the migration of ECs expressing EphB receptors into the intersomitic region where ephrin-B2 expression is normally absent. CAGp-ephrin-B2 Tg mice show sudden death at neonatal stages from aortic dissecting aneurysms due to defective recruitment of vascular smooth muscle cells to the ascending aorta. EphB/ephrin-B2 signaling between endothelial cells and surrounding mesenchymal cells plays an essential role in vasculogenesis, angiogenesis, and vessel maturation.     

Movements of truncated kinesin fragments with a short or an artificial flexible neck

To investigate the role of the neck domain of kinesin, we used optical trapping nanometry to perform high-resolution measurements of the movements and forces produced by recombinant kinesin fragments in which the neck domains were shortened or replaced by an artificial random coil. Truncated kinesin fragments (K351) that contain a motor domain consisting of ≈340 aa and a short neck domain consisting of ≈11 aa showed fast movement (800 nm/s) and 8-nm steps. Such behavior was similar to that of recombinant fragments containing the full-length neck domain (K411) and to that of native kinesin. Kinesin fragments lacking the short neck domain (K340), however, showed very slow movement (<50 nm/s), as previously reported. Joining an artificial 11-aa sequence that was expected to form a flexible random chain to the motor domain (K340–chain) produced normal fast (≈700 nm/s) and stepwise movement. The results suggest that the neck domain does not act as a rigid lever arm to magnify the structural change at the catalytic domain as has been believed for myosin, but it does act as a flexible joint to guarantee the mobility of the motor domain.     

The role and therapeutic targeting of IL-6 in rheumatoid arthritis

Introduction: Rheumatoid arthritis (RA) is an autoimmune chronic disease with joint and systemic inflammation and it has been found that interleukin-6 (IL-6) plays a key role in RA. Indeed, various clinical studies have proved that the first-in-class IL-6 inhibitor, tocilizumab, a humanized anti-IL-6 receptor monoclonal antibody, showed outstanding efficacy in RA.

Areas covered: We review here the role of IL-6 in the inflammatory conditions and how IL-6 contributes to pathogenesis of RA, what induces IL-6 and how IL-6 expression is regulated. Furthermore, clinical studies of tocilizumab for RA are summarized,

Expert commentary: We review and discuss the prospects for future applications of IL-6 targeting therapy and new therapeutic strategies targeting IL-6. Finally, we discuss relevant issues with regard to the clinical management of IL-6 blockade in RA.     

First molecular detection and characterization of Hepatozoon and Sarcocystis spp. in field mice and voles from Japan

Sarcocystis and Hepatozoon species are protozoan parasites that are frequently detected in domestic and wild animals. Rodents are considered common intermediate and paratenic hosts for several Sarcocystis and Hepatozoon species. Here, blood DNA samples from a total of six rodents, including one Myodes rutilus, one Myodes rufocanus, and four Apodemus speciosus, collected from Hokkaido, Japan, were shown by conventional PCR of the 18S ribosomal RNA (rRNA) gene to contain Sarcocystis and Hepatozoon DNA. Sequencing of the DNA detected one Sarcocystis sp. in the M. rufocanus sample and two different Hepatozoon spp. in the M. rutilus and A. speciosus samples. Phylogenetic analysis showed that the detected Sarcocystis sp. sequence grouped with GenBank Sarcocystis sequences from rodents, snakes, and raccoons from Japan and China. The 18S rRNA partial gene sequences of both detected Hepatozoon spp. clustered with GenBank Hepatozoon sequences from snakes, geckos and voles in Europe, Africa, and Asia. This study provides evidence that wild rodents have a role in the maintenance of Sarcocystis and Hepatozoon species on the island of Hokkaido.

     

Leptin upregulation in advanced multiple system atrophy with hypocholesterolemia and unexpected fat accumulation

Advanced multiple system atrophy (MSA) patients exhibit malnutrition with hypocholesterolemia and hypoalbuminemia, similar to patients with other neurodegenerative disorders, but also display unexpected fat accumulation. To understand this paradox, we herein examined the relationship between fat accumulation, measured by triceps skinfold thickness (TSF), and plasma leptin in 29 MSA patients at three clinical stages: activities of daily living (ADL) 1: ambulatory with/without wheelchair; ADL2: bedridden/communicable; and ADL3: bedridden/non-communicable. TSF and leptin were higher while cholesterol and albumin were lower in advanced stage ADL3 than in ADL1 or ADL2. Although a correlation was observed between leptin and TSF, a stepwise regression analysis identified the first significant positive predictor of leptin as the duration of autonomic symptoms (p < 0.005) rather than TSF. Leptin/TSF strongly correlated with the duration of autonomic symptoms (p < 0.001). These results implicate leptin resistance through autonomic dysfunction in the paradoxical fat accumulation observed in patients with advanced MSA, but not to be seen in the cholesterol metabolism.     

Effect of oral immunotherapy in children with milk allergy: The ORIMA study

BackgroundThis study was aimed at evaluating the efficacy and safety of oral immunotherapy (OIT) in children with severe cow's milk allergy.MethodsThe subjects comprised 28 children (aged 3–12 years) with allergic symptoms that were induced by ≤ 10 mL of cow's milk in an oral food challenge test (OFC). The subjects were randomly allocated to the treatment group (n = 14) and control group (n = 14); the former received rush immunotherapy for 2 weeks, followed by a gradual increase of cow's milk volume to 100 mL for 1 year, and the latter completely eliminated cow's milk for 1 year. Both groups underwent an OFC with 100 mL of cow's milk after 1 year.ResultsThe treatment group had significantly higher rates of a negative OFC [7/14 (50%) vs. 0/14 (0%), p < 0.01] compared with the control group. The cow's milk-specific IgE level significantly decreased in the treatment group (p < 0.01) but not in the control group (p = 0.63). During the study period, adrenaline was required in 6/14 patients (43%) of the treatment group and in 0/14 patients (0%) of the control group. Long follow-up data were available at the 2-year point after the study for 8 in the treatment group and 7 (87.5%) of these continued to ingest milk (>100 mL).ConclusionsThe effect of immunotherapy was 50%, but the incidence of adverse events was not low. Further studies focusing on safety is necessary to standardize OIT for cow's milk allergy.     

High blood pressure worsens age-related increases in arterial stiffness evaluated by pulse wave velocity in subjects with lifestyle-related diseases

Objective:   Arterial stiffness is a risk factor for cardiovascular diseases, and is altered by age and blood pressure. Lifestyle-related diseases are also major risk factors for cardiovascular events and influence arterial stiffness. The goal of this study was to clarify the clinical influence of aging on pulse wave velocity in patients with hypertension, diabetes and/or dyslipidemia.
Methods:   Eight hundred and forty-seven outpatients (480 males, 367 females, mean age 61.5 years) at the Division of Geriatric Medicine and Hypertension in Osaka University Hospital who had lifestyle-related diseases such as hypertension ( n  = 720), diabetes ( n  = 228) and dyslipidemia ( n  = 613) were enrolled. We evaluated arterial stiffness as measured by carotid-femoral pulse wave velocity.
Results:   After age and systolic blood pressure adjustment, pulse wave velocity was higher in hypertensive patients ( P  = 0.0048), but not in patients with diabetes or dyslipidemia. By single linear regression analysis, pulse wave velocity and age were positively correlated in patients with ( r  = 0.359, P  < 0.0001) and without ( r  = 0.377, P  < 0.0001) hypertension, and the regression coefficients of these two groups were similar. Moreover, these variables were positively correlated with pulse wave velocity in hypertensive patients receiving medication ( r  = 0.324, P  < 0.0001) and without medication ( r  = 0.425, P  < 0.0001), and the regression coefficient with medication (0.033) was lower than that without medication (0.045).
Conclusion   These data suggest that the presence of hypertension worsened the age-related increase in arterial stiffness in patients with lifestyle-related diseases.     

Medication-taking behavior in hypertensive patients with a single-tablet,fixed-dose combination in Japan

Non-persistence rate (defined as not remaining on treatment) in patients taking a renin angiotensin system inhibitor plus calcium channel blocker was studied in three integrated 12-weeks surveys by matching separate drug combination therapy (CT) and fixed-dose combination (FDC). We also investigated medication adherence measured by proportion of days covered by using a claims database. The non-persistence rate was significantly lower in FDC than CT (p?=?0.0074). In the database study, the medication adherence was higher in FDC than CT for 3, 6, and 12 months (all p?<?0.001). In conclusion, use of single-tablet FDC antihypertensive therapy was associated with better medication-taking behavior.     

Fluorescence analysis of biochemical constituents identifies atherosclerotic plaque with a thin fibrous cap

Vulnerable plaque generally contains a thin fibrous cap, lipid pools, and reduced internal plaque collagen. Arterial fluorescence analysis can differentiate atherosclerotic lesions from normal arteries; however, the contribution of the lipid core to atherosclerotic arterial fluorescence remains controversial. This study aimed to identify lipid core fluorophores and to differentiate the lipid core from normal artery and atheroma. The helium-cadmium laser-induced fluorescence spectra of cadaveric arteries and known chemical constituents were recorded. Lipid core fluorescence spectra exhibited marked red shifts and broadening compared with the fluorescence spectra of normal tissue and atheroma. Similar fluorescence spectra were obtained for lipid core and oxidized low density lipoprotein, for atheroma and collagen, and for normal artery and elastin. A classification based on collagen, elastin, and oxidized low density lipoprotein spectral decomposition could discriminate the lipid core (n=29), normal artery (n=74), atheroma (n=73), and preatheroma (n=10) with 86% accuracy. Fibrous cap thickness was correlated with the spectral collagen content index (r=0.65, P<0.0001), especially at a thickness of <200 microm. We conclude that a classification algorithm based on chemical spectral decomposition can accurately classify the fluorescence spectra of normal artery, atheroma, and lipid core and may be useful in identifying vulnerable atheroma in vivo.