Interleukin-6 as an independent predictor of future cardiovascular events in high-risk Japanese patients: comparison with C-reactive protein

Inflammation is associated with the development of atherosclerotic vascular lesions and some inflammatory parameters are used as cardiovascular (CV) risk markers. The present study was designed to assess the predictive power of interleukin (IL)-6 for future CV events. In 121 Japanese patients with multiple CV risk factors and/or disease, serum concentrations of IL-6 and high sensitive C-reactive protein (hs-CRP) were measured. During follow-up periods (mean, 2.9 years) after the baseline assessment, 50 patients newly experienced CV events such as stroke/transient ischemic attack (n=10), heart failure hospitalization (n=6), acute coronary syndrome (n=7), and revascularization for coronary artery disease (n=15) and peripheral arterial disease (n=12). The serum level of IL-6, but not hs-CRP, was significantly higher in patients who had CV events than in event-free subjects (3.9±2.6 and 3.0±2.2 pg/mL, P=0.04). When the patients were divided into three groups by tertiles of basal levels of IL-6 (<1.85, 1.85-3.77, and ≥3.77 pg/mL), cumulative event-free rates by the Kaplan-Meier method were decreased according to the increase in basal IL-6 levels (65%, 50%, and 19% in the lowest, middle, and highest tertiles of IL-6, respectively; log-rank test, P=0.002). By univariate Cox regression analysis, previous CV disease, creatinine clearance, and serum IL-6 levels were significantly associated with CV events during follow-up. Among these possible predictors, the highest tertile of IL-6 was only an independent determinant for the morbidity in the multivariate analysis (hazard ratio 2.80 vs. lowest tertile, P=0.006). These findings indicate that IL-6 is a powerful independent predictor of future CV events in high-risk Japanese patients, suggesting its predictive value is superior to that of hs-CRP.     

Ultrafine cellulose fibers produced by Asaia bogorensis, an acetic acid bacterium

The ability to synthesize cellulose by Asaia bogorensis, a member of the acetic acid bacteria, was studied in two substrains, AJ and JCM. Although both strains have identical 16S rDNA sequence, only the AJ strain formed a solid pellicle at the air-liquid interface in static culture medium, and we analyzed this pellicle using a variety of techniques. In the presence of cellulase, glucose and cellobiose were released from the pellicle suggesting that it is made of cellulose. Field emission electron microscopy allowed the visualization of a 3D knitted structure with ultrafine microfibrils (approximately 5-20 nm in width) in cellulose from A. bogorensis compared with the 40-100 nm wide microfibrils observed in cellulose isolated from Gluconacetobacter xylinus, suggesting differences in the mechanism of cellulose biosynthesis or organization of cellulose synthesizing sites in these two related bacterial species. Identifying these differences will lead to a better understanding of cellulose biosynthesis in bacteria.     

Donepezil, anti-Alzheimer's disease drug, prevents cardiac rupture during acute phase of myocardial infarction in mice

Background

We have previously demonstrated that the chronic intervention in the cholinergic system by donepezil, an acetylcholinesterase inhibitor, plays a beneficial role in suppressing long-term cardiac remodeling after myocardial infarction (MI). In comparison with such a chronic effect, however, the acute effect of donepezil during an acute phase of MI remains unclear. Noticing recent findings of a cholinergic mechanism for anti-inflammatory actions, we tested the hypothesis that donepezil attenuates an acute inflammatory tissue injury following MI.

Methods and Results

In isolated and activated macrophages, donepezil significantly reduced intra- and extracellular matrix metalloproteinase-9 (MMP-9). In mice with MI, despite the comparable values of heart rate and blood pressure, the donepezil-treated group showed a significantly lower incidence of cardiac rupture than the untreated group during the acute phase of MI. Immunohistochemistry revealed that MMP-9 was localized at the infarct area where a large number of inflammatory cells including macrophages infiltrated, and the expression and the enzymatic activity of MMP-9 at the left ventricular infarct area was significantly reduced in the donepezil-treated group.

Conclusion

The present study suggests that donepezil inhibits the MMP-9-related acute inflammatory tissue injury in the infarcted myocardium, thereby reduces the risk of left ventricular free wall rupture during the acute phase of MI.     

Pdx1 and Ngn3 overexpression enhances pancreatic differentiation of mouse ES cell-derived endoderm population

In order to define the molecular mechanisms regulating the specification and differentiation of pancreatic β-islet cells, we investigated the effect of upregulating Pdx1 and Ngn3 during the differentiation of the β-islet-like cells from murine embryonic stem (ES) cell-derived activin induced-endoderm. Induced overexpression of Pdx1 resulted in a significant upregulation of insulin (Ins1 and Ins2), and other pancreas-related genes. To enhance the developmental progression from the pancreatic bud to the formation of the endocrine lineages, we induced the overexpression express of Ngn3 together with Pdx1. This combination dramatically increased the level and timing of maximal Ins1 mRNA expression to approximately 100% of that found in the βTC6 insulinoma cell line. Insulin protein and C-peptide expression was confirmed by immunohistochemistry staining. These inductive effects were restricted to c-kit(+) endoderm enriched EB-derived populations suggesting that Pdx1/Ngn3 functions after the specification of pancreatic endoderm. Although insulin secretion was stimulated by various insulin secretagogues, these cells had only limited glucose response. Microarray analysis was used to evaluate the expression of a broad spectrum of pancreatic endocrine cell-related genes as well as genes associated with glucose responses. Taken together, these findings demonstrate the utility of manipulating Pdx1 and Ngn3 expression in a stage-specific manner as an important new strategy for the efficient generation of functionally immature insulin-producing β-islet cells from ES cells.     

Molecular dissection of a medicinal herb with anti-tumor activity by oligonucleotide microarray

It is difficult to understand precisely the physiological actions of herbs because they contain a complex array of constituent molecules. In the present study we used DNA microarray data for 12600 genes to examine the anti-proliferative activity of the herb Coptidis rhizoma and eight constituent molecules against eight human pancreatic cancer cell lines. We identified 27 genes showing strong correlation with the 50% inhibitory dose (ID50) of C. rhizoma after 72-h exposure. Hierarchical cluster analysis with correlation coefficients between expression levels of these 27 C. rhizoma-related genes and the ID50 of each constituent molecule classified these test molecules into two clusters, one consisting of C. rhizoma and berberine and the other consisting of the remaining seven molecules. Our results suggest that one molecule, berberine, can account for the majority of the anti-proliferative activity of C. rhizoma and that DNA microarray analyses can be used to improve our understanding of the actions of an intact herb.     

Selfing and inbreeding depression in seeds and seedlings of Neobalanocarpus heimii (Dipterocarpaceae)

We evaluated the degree of selfing and inbreeding depression at the seed and seedling stages of a threatened tropical canopy tree, Neobalanocarpus heimii, using microsatellite markers. Selection resulted in an overall decrease in the level of surviving selfed progeny from seeds to established seedlings, indicating inbreeding depression during seedling establishment. Mean seed mass of selfed progeny was lower than that of outcrossed progeny. Since the smaller seeds suffered a fitness disadvantage at germination in N. heimii, the reduced seed mass of selfed progeny would be one of the determinants of the observed inbreeding depression during seedling establishment. High selfing rates in some mother trees could be attributed to low local densities of reproductive individuals, thus maintenance of a sufficiently high density of mature N. heimii should facilitate regeneration and conservation of the species.     

Transgenic rats overexpressing the human MrgX3 gene show cataracts and an abnormal skin phenotype

The human MrgX3 gene, belonging to the mrgs/SNSRs (mas related genes/sensory neuron specific receptors) family, was overexpressed in transgenic rats using the actin promoter. Two animal lines showed cataracts with liquification/degeneration and swelling of the lens fiber cells. The transient epidermal desquamation was observed in line with higher gene expression. Histopathology of the transgenic rats showed acanthosis and focal parakeratosis. In the epidermis, there was an increase in cellular keratin 14, keratin 10, and loricrin, as well as PGP 9.5 in innervating nerve fibers. These phenotypes accompanied an increase in the number of proliferating cells. These results suggest that overexpression of the human MrgX3 gene causes a disturbance of the normal cell-differentiation process.     

Involvement of RhoA-mediated Ca2+ sensitization in antigen-induced bronchial smooth muscle hyperresponsiveness in mice

Background

It has recently been suggested that RhoA plays an important role in the enhancement of the Ca²⁺ sensitization of smooth muscle contraction. In the present study, a participation of RhoA-mediated Ca²⁺ sensitization in the augmented bronchial smooth muscle (BSM) contraction in a murine model of allergic asthma was examined.

Methods

Ovalbumin (OA)-sensitized BALB/c mice were repeatedly challenged with aerosolized OA and sacrificed 24 hours after the last antigen challenge. The contractility and RhoA protein expression of BSMs were measured by organ-bath technique and immunoblotting, respectively.

Results

Repeated OA challenge to sensitized mice caused a BSM hyperresponsiveness to acetylcholine (ACh), but not to high K⁺-depolarization. In α-toxin-permeabilized BSMs, ACh induced a Ca²⁺ sensitization of contraction, which is sensitive to Clostridium botulinum C3 exoenzyme, indicating that RhoA is implicated in this Ca²⁺ sensitization. Interestingly, the ACh-induced, RhoA-mediated Ca²⁺ sensitization was significantly augmented in permeabilized BSMs of OA-challenged mice. Moreover, protein expression of RhoA was significantly increased in the hyperresponsive BSMs.

Conclusion

These findings suggest that the augmentation of Ca²⁺ sensitizing effect, probably via an up-regulation of RhoA protein, might be involved in the enhanced BSM contraction in antigen-induced airway hyperresponsiveness.