Proinflammatory protein CARD9 is essential for infiltration of monocytic fibroblast precursors and cardiac fibrosis caused by Angiotensin II infusion

Background

Angiotensin II (Ang II)–induced cardiac remodeling with the underlying mechanisms involving inflammation and fibrosis has been well documented. Cytosolic adaptor caspase recruitment domain 9 (CARD9) has been implicated in the innate immune response. We aimed to examine the role of CARD9 in inflammation and cardiac fibrosis induced by Ang II.

Methods

Two-month-old CARD9-deficient (CARD9^−/−) and wild-type (WT) male mice were infused with Ang II (1,500 ng/kg/min) or saline for 7 days. Heart sections were stained with hematoxylin and eosin and Masson trichrome and examined by immunohistochemistry; and activity and protein levels were measured in macrophages obtained from mice.

Results

WT mice with Ang II infusion showed a marked increase in CARD9⁺ macrophages in the heart, but CARD9^−/− mice showed significantly suppressed macrophage infiltration and expression of proinflammatory cytokines, including interleukin-1β (IL-1β) and connective tissue growth factor (CTGF). Importantly, Ang II–induced cardiac fibrosis (extracellular matrix and collagen I deposition) was diminished in CARD9^−/− hearts, as was the expression of transforming growth factor-β (TGF-β) and level of myofibroblasts positive for α-smooth muscle actin (α-SMA). Furthermore, Ang II activation of nuclear factor-κB (NF-κB), JNK and p38 mitogen-activated protein kinases (MAPKs) in WT macrophages was reduced in CARD9^−/− macrophages.

Conclusion

CARD9 plays an important role in regulating cardiac inflammation and fibrosis in response to elevated Ang II.

Characterization of short-lived electrophilic metabolites of the anticancer agent laromustine (VNP40101M)

Laromustine (VNP40101M; 1,2-bis(methylsulfonyl)-1-(2-chloroethyl)-2-(methylamino) carbonylhydrazine) is a novel sulfonylhydrazine alkylating agent. Phase 1 metabolism of laromustine was reported recently and showed that laromustine undergoes rearrangement, dehalogenation, and hydrolysis at physiological pH to form active moieties. (1) A mechanism for the rearrangement was proposed on the basis of fragmentation ions. (1) (,) (2) In this article, we report the phase II conjugates of VNP40101M and VNP4090CE which were formed after incubation of VNP40101M or VNP4090CE with pooled human liver microsomes (HLM) and cofactors nicotinamide adenine dinucleotide phosphate (NADPH), glutathione (GSH), N-acetylecysteine (NAC), and cysteine (CYS). Eight novel phase II conjugates (M-1 to M-8) were identified and characterized by hydrogen-deuterium exchange (H-D), stable isotope ((13)C-labeled VNP40101M), and MS(n) experiments. M-4 and M-5 were further confirmed by nuclear magnetic resonance spectroscopy (NMR). The short-lived CH(3)SO(2)CH(2)CH(2)-, methylformamide and CH(3)SO(2)NHN═CHCH(2)- moieties were generated from VNP40101M. The reactive intermediates CH(3)SO(2)CH(2)CH(2)- and methylformamide formed conjugates with GSH, CYS, and NAC. The CH(3)SO(2)NHN═CHCH(2)- moiety formed conjugates with GSH and NAC. M-2, M-4, and M-6 were only detected from the incubation of VNP40101M because VNP4090CE does not contain a methylformamide group. All other conjugates were formed by both VNP40101M and VNP4090CE. The in vitro studies found that VNP40101M and VNP4090CE undergo activation in human liver microsomes. The results from this study showed that laromustine produces several reactive intermediates that may play a role in the toxicities seen in the clinical trials.

Expressing acid-sensing ion channel 3 in the brain alters acid-evoked currents and impairs fear conditioning

Previous studies on mice with a disruption of the gene encoding acid-sensing ion channel 1a (ASIC1a) suggest that ASIC1a is required for normal fear behavior. To investigate the effects of altering the subunit composition of brain ASICs on behavior, we developed transgenic mice expressing ASIC3 via the pan-neuronal synapsin I promoter. These mice express ASIC3 in the brain, where the endogenous ASIC3 protein is not detected. We found that in ASIC3 transgenic mice, ASIC3 co-immunoprecipitated with the endogenous ASIC1a protein and distributed in the same subcellular brain fractions as ASIC1a. In addition, ASIC3 significantly increased the rate of desensitization of acid-evoked currents in cultured cortical neurons. Importantly, ASIC3 reduced Pavlovian fear conditioning to both context and auditory cues. These observations suggest that ASIC3 can heteromultimerize with ASIC1a in the brain and alter the biophysical properties of the endogenous channel complex. Moreover, these data suggest that ASIC subunit composition and channel desensitization may be critical determinants for ASIC-dependent behavior.

Influence of rare-earth ions on SiO₂-Na₂O-RE₂O₃ glass structure

Praseodymium and europium sodium silicate glasses of nominal composition (SiO(2))(0.70 - x)(Na(2)O)(0.30)(RE(2)O(3))(x), where RE is the rare earth and 0 ≤ x ≤ 0.10, were studied by neutron and high-energy x-ray scattering and classical molecular dynamics simulations. The observation of a significant x-ray intensity in doped as compared to un-doped glasses is indicative of RE-RE correlations at a distance of ∼ 3.7-3.9 Å, much shorter than would be expected for a homogeneous distribution, suggesting that clustering of the rare-earth cations occurs in both these glass systems at low concentrations. Above x = 0.075 (nominal), minimal changes in this region indicate that the RE atoms are incorporated much more randomly into the glass structure. The molecular dynamics simulations suggest that the rare-earth ions enter the sodium-rich regions in the sodium silicate glasses and act as modifiers. A cluster analysis performed on the model systems indicates that the tendency for clustering is higher in praseodymium-containing glasses than in the europium glasses.

Optimization of iron oxide nanoparticle detection using ultrashort echo time pulse sequences: comparison of T1, T2*, and synergistic T1- T2* contrast mechanisms

Iron oxide nanoparticles (IONPs) are used in various MRI applications as negative contrast agents. A major challenge is to distinguish regions of signal void due to IONPs from those due to low signal tissues or susceptibility artifacts. To overcome this limitation, several positive contrast strategies have been proposed. Relying on IONP T(1) shortening effects to generate positive contrast is a particularly appealing strategy because it should provide additional specificity when associated with the usual negative contrast from effective transverse relaxation time (T(2)*) effects. In this article, ultrashort echo time imaging is shown to be a powerful technique which can take full advantage of both contrast mechanisms. Methods of comparing T(1) and T(2)* contrast efficiency are described and general rules that allow optimizing IONP detection sensitivity are derived. Contrary to conventional wisdom, optimizing T(1) contrast is often a good strategy for imaging IONPs. Under certain conditions, subtraction of a later echo signal from the ultrashort echo time signal not only improves IONP specificity by providing long T(2)* background suppression but also increases detection sensitivity, as it enables a synergistic combination of usually antagonist T(1) and T(2)* contrasts. In vitro experiments support our theory, and a molecular imaging application is demonstrated using tumor-targeted IONPs in vivo.

Nuclear accumulation of glioma-associated oncogene 2 protein and enhanced expression of forkhead-box transcription factor M1 protein in human hepatocellular carcinoma

The hedgehog (Hh) signaling pathway has been reported to be crucial in human carcinogenesis and tumor progression. Glioma-associated oncogenes (Gli), are zinc finger transcription factors which mediate the transcriptional response to Hh signaling. To explore the role of Gli in the development and progression of hepatocellular carcinoma (HCC), we investigated the expression of Gli2 and FoxM1 (forkhead-box transcription factor M1) which is one of the Gli downstream target genes modulating cell cycle progression in 91 specimens of human HCCs with immunohistochemistry. These immunostaining results were compared with various clinicopathologic parameters. Immunoreactivity of Gli2 and FoxM1 was observed respectively in 84.6% (77/91) and 80.2% (73/91) cases of HCC tumor tissues, and this was considerably higher than expression in the peritumoral tissues. Distribution of Gli2 and FoxM1 proteins in tumor cells was nuclear with or without cytoplasmic staining, or cytoplasmic alone. Statistically, increased nuclear immunopositivity of Gli2 protein correlated significantly with poorer tumor differentiation (P<0.05), as well as with portal vein tumor thrombosis (P<0.05). In addition, overexpression of FoxM1 protein was significantly associated with increased tumor grade (P<0.01) and advanced tumor stage (P<0.05). Moreover, there was a significant association between the expressions of Gli2 and FoxM1 proteins in HCC (r=0.464, P=0.000). This is consistent with the concept that in human HCC, the Hh signaling pathway is involved in the differentiation and proliferation of tumor cells, in part through inducing nuclear accumulation of Gli2 protein and subsequent upregulation of FoxM1 protein.

Phylogeography and conservation genetics of Lake Qinghai scaleless carp Gymnocypris przewalskii

The objective of this study was to examine the spatial genetic relationships of the Lake Qinghai scaleless carp Gymnocypris przewalskii within the Lake Qinghai system, determining whether genetic evidence supports the current taxonomy of Gymnocypris przewalskii przewalskii and Gymnocypris przewalskii ganzihonensis and whether Gymnocypris przewalskii przewalskii are returning to their natal rivers to spawn. Comparison of mitochondrial (control region) variation (42 haplotypes in 203 fish) of G. przewalskii with the postulated ancestral species found in the Yellow River, Gymnocypris eckloni (10 haplotypes in 23 fish), indicated no haplotype sharing, but incomplete lineage sorting. Consistent with the sub-species status, an AMOVA indicated that the Ganzi River population was significantly different from all other river populations (F(ST) = 0·1671, P < 0·001). No genetic structure was found among the other rivers in the Lake Qinghai catchment. An AMOVA of amplified fragment length polymorphism (AFLP) loci, however, revealed significant genetic differences between most spawning populations (F(ST) = 0·0721, P < 0·001). Both mitochondrial and AFLP data found significant differences among G. p. przewalskii, G. p. ganzihonensis and G. eckloni (F(ST) values of 0·1959 and 0·1431, respectively, P < 0·001). Consistent with the incomplete lineage sorting, Structure analysis of AFLP loci showed evidence of five clusters. One cluster is shared among all sample locations, one is unique to G. p. ganzihonensis and G. eckloni, and the others are mostly found in G. p. przewalskii. Genetic evidence therefore supports the current taxonomy, including the sub-species status of G. p. ganzihonensis, and is consistent with natal homing of most Lake Qinghai populations. These findings have significant implications for the conservation and management of this unique and threatened species. The evidence suggests that G. p. przewalskii should be treated as a single population for conservation purposes. Exchangeability of the populations, however, should not be used to promote homogenization of fish spawning in the different rivers. As some degree of genetic divergence was detected in this study, it is recommended that the spawning groups be treated as separate management units.

Role of Rac1-dependent NADPH oxidase in the growth of pancreatic cancer

K-ras mutations occur in as high as 95% of patients with pancreatic cancer. K-ras activates Rac1-dependent NADPH oxidase, a key source of superoxide. Superoxide plays an important role in pancreatic cancer cell proliferation and scavenging or decreasing the levels of superoxide inhibits pancreatic cancer cell growth both in vitro and in vivo. DNA microarray analysis and RT-PCR has demonstrated that Rac1 is also upregulated in pancreatic cancer. The aim of this study was to determine if inhibiting Rac1 would alter pancreatic tumor cell behavior. Human pancreatic cancer cells with mutant K-ras (MIA PaCa-2), wild-type K-ras (BxPC-3), and the immortal H6c7 cell line (pancreatic ductal epithelium) expressing K-ras oncogene (H6c7eR-KrasT) that is tumorigenic, were infected with a dominant/negative Rac1 construct (AdN17Rac1). In cells with mutant K-ras, AdN17Rac1 decreased rac activity, decreased superoxide levels, and inhibited in vitro growth. However in the BxPC-3 cell line, AdN17Rac1 did not change rac activity, superoxide levels, or in vitro cell growth. Additionally, AdN17Rac1 decreased superoxide levels and inhibited in vitro growth in the KrasT tumorigenic cell line, but had no effect in the immortalized H6c7 cell line. In human pancreatic tumor xenografts, intratumoral injections of AdN17Rac1 inhibited tumor growth. These results suggest that activation of Rac1-dependent superoxide generation leads to pancreatic cancer cell proliferation. In pancreatic cancer inhibition of Rac1 may be a potential therapeutic target.

Neuronal apoptosis in the developing cerebellum

The following study analysed apoptosis in proliferative cells and migrating neurons of the developing cerebellum. The external granular layer, Purkinje cell layer and internal granular layer in the developing mouse cerebellar cortex were analysed by active caspase-3 immunohistochemistry, Hoechst 33258 staining and Western blot analysis. Immunocytochemistry results indicated that the peak of apoptosis appeared at postnatal days P8, P5 and P9 in the external granular layer, Purkinje cell layer and internal granular layer, respectively. Subsequently, in each region, the rate of apoptosis decreased with increasing age. In contrast, Western blot results demonstrated the highest expression of activated caspase-3 in the cerebellum at P5, followed by a subsequent decline and disappearance of expression by P14. Activated caspase-8 was expressed maximally at P10, and subsequently disappeared by P30. The results of this study suggest that the key period of neuronal apoptosis in the cerebellar cortex is between P0 and P14, indicating that this developmental period could be susceptible to treatment for congenital neurodegenerative diseases.

Relationship between response to risperidone, plasma concentrations of risperidone and CYP3A4 polymorphisms in schizophrenia patients

In this study, we examined the relationships between plasma concentrations of risperidone and 9-hydroxyrisperidone and polymorphisms of CYP3A4. All 130 schizophrenia patients (45 men, 85 women, age 15-60 years) who met DSM-IV criteria were given risperidone for 8 weeks. Clinical efficacy was determined using the Positive and Negative Syndrome Scale (PANSS). CYP3A4*1G was found to be associated with the change in total PANSS scores (Kruskal-Wallis test, P = 0.021), which was not significant on adjusting for multiple testing. Our study has, for the first time, conducted a genetic association study of the CYP3A4 gene with risperidone response. Further studies on larger groups and on the effects of the longer term risperidone treatment are needed to confirm these results.

A survey of bone mineral density of healthy Han adults in China

A recent survey of bone mineral density (BMD) in China recruited 7,042 healthy Han Chinese aged 20 years and older. The mean BMDs were different in gender, age, and region; the proportions of men and women older than 50 years with a high risk of osteoporosis were estimated as 10.4% and 31.2%, respectively

INTRODUCTION

A survey of BMD was completed during 2002-2006 in China. By three-stage sampling, a total of 7,042 healthy Han Chinese aged 20 years and older were recruited in ten cities: 2,694 subjects from Beijing, Tianjin, Haerbin, Lanzhou, and Yantai of northern China and 4,348 from Shanghai, Changsha, Chengdu, Haikou, and Foshan of southern China.

METHODS

Two dual X-ray absorptiometry (DXA) systems (Hologic and Lunar) were used with parallel measurements of the European spine phantoms in each center. The mean BMDs in age groups older than 50 and the peak bone mineral density (pBMD) at femoral neck and that at greater trochanter were higher for men than women, and the pBMDs for northern China were higher than those for southern China, ranging from 1% to 4%.

DISCUSSION AND CONCLUSION

This work has provided two useful references for the first time: one is the estimation of the proportion and number of individuals older than 50 years with a high risk of osteoporosis, 10.4% and 12.5 million men, 31.2% and 37.2 million women, which is important for health care planning and marketing projections, and another is the conversion equations for cross-calibration among different types of DXA instruments frequently used in China.

Tanshinone IIA pretreatment protects myocardium against ischaemia/reperfusion injury through the phosphatidylinositol 3-kinase/Akt-dependent pathway in diabetic rats

AIM

Diabetes Mellitus (DM) is widely acknowledged to increase the risk of cardiovascular death, which warrants the use of aggressive primary prevention strategies. The aim of the present study was to investigate the pretreatment effects of tanshinone IIA (TSN), a traditional Chinese medicine, on myocardial infarct size, apoptosis, inflammation and cardiac functional recovery in diabetic rats subjected to myocardial ischaemia/reperfusion (I/R).

METHODS

Streptozocin (STZ) induced diabetic rats (n = 80) were randomized to receive TSN, TSN plus wortmannin [a phosphatidylinositol 3-kinase (PI3K) inhibitor] or saline. They were exposed to a 30-min ischaemia by ligation of the left coronary artery except for the sham group. Haemodynamics, infarct size and myocardial apoptosis were examined 3 h after reperfusion. The effects of TSN on Akt and NF-kappaB phosphorylation and the expression of tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in cardiac tissues were examined.

RESULTS

Our results revealed that TSN administration significantly reduced myocardial infarct size (0.252 +/- 0.038 vs. 0.327 +/- 0.027, p < 0.05), improved left ventricular ejection fraction (LVEF) (0.774 +/- 0.058 vs. 0.716 +/- 0.054, p < 0.05), decreased myocardial apoptotic death (0.114 +/- 0.026 vs. 0.191 +/- 0.023, p < 0.05) compared with I/R group. Western blot analysis showed that TSN treatment enhanced Akt phosphorylation and inhibited NF-kappaB phosphorylation in cardiac tissues. Moreover, pretreatment with wortmannin abolished the beneficial effects of TSN: a reduction of infarct size, a decrease in LVEF, inhibition of myocardial apoptosis and Akt phosphorylation, enhancement of NF-kappaB phosphorylation and an increase of cytokine production including TNF-alpha and IL-6 after I/R injury in diabetic rats.

CONCLUSIONS

This study indicates that TSN pretreatment reduces infarct size and improves cardiac dysfunction after I/R injury in diabetic rats. This was accompanied with decreased cardiac apoptosis and inflammation. The possible mechanism responsible for the effects of TSN is associated with the PI3K/Akt-dependent pathway.

High dielectric loss in graphite-coated Ti nanocapsules

Graphite-coated Ti nanocapsules, with Ti nanoparticles as core and onion-like graphite layers as shell, have been prepared by a modified arc-discharge method in ethanol atmosphere, and characterized by means of X-ray diffraction, transmission electron microscopy and Raman spectroscopy. The dielectric properties of the graphite-coated Ti nanocapsules have been investigated in the 2-18 GHz range. An equivalent circuit model was used to interpret the non-linear dielectric resonance behavior of the graphite-coated Ti nanocapsules. The high dielectric loss is mainly attributed to conductance loss and dipole-relaxation loss in the graphite-coated Ti nanocapsules. The graphite-coated Ti nanocapsules exhibit promising properties for application as a new type of shield or absorbent of electromagnetic waves.

Palmitic acid and docosahexaenoic acid opposingly regulate the expression of insulin-degrading enzyme in neurons

Previous results show that treatment with saturated fatty acids, such as palmitic acid (PA), induces the pathology of Alzheimer's disease (AD), while treatment with polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), protects against AD pathology. However, the pharmacological mechanism underlying these opposite effects of fatty acids on AD is not well understood. Here, we show that PA treatment significantly reduced the expression of insulin-degrading enzyme (IDE), an important protease responsible for the degradation of amyloid-beta (A beta) in neural cells, while incubation with DHA up-regulated IDE levels in primary hippocampal neurons. Moreover, pre-incubation with PA attenuated the DHA-induced IDE expression. Taken together, these results suggest the opposite effects of saturated fatty acids and polyunsaturated fatty acids on the expression of IDE, indicating a novel mechanism underlying the pharmacological function of fatty acids in AD intervention.

Numerical Modelling of Geomechanical Response of Sandy-Shale Formation in Oil Sands Reservoir During Steam Injection

Abstract

In this study, we conducted numerical simulations of steam injection into a horizontal well. A sandy-shale layer with thickness of 1 metre is located 2 metre above a horizontal injection well. The numerical simulations intend to study the variations of the stress state and the permeability in the sandy-shale layer during steam injection, and to provide useful effective stress paths for laboratory experiments to follow when testing material properties of the sandy-shale. A self-developed coupled geomechanics and thermal multi-phase flow simulator was employed to conduct the simulation cases. A strain-induced permeability model was used to describe the anisotropic permeability change of the sandy-shale caused by steam injection. The simulation results demonstrate that the permeability of 5 and 50 md for the sandy-shale in two simulation cases is sufficient to allow pore pressure dissipation to occur, therefore, preventing tensile or shear failure of sandy-shale as a result of high thermal-induced pore pressure. The stress paths within the sandy-shale are approaching the failure envelope as steam injection goes on indicating simultaneous influence of the temperature and the pore pressure on the stress state change.

Introduction

Sandy-shale formations of several metres in thickness frequently exist in oil sands deposit. Their material properties, sedimentary characteristics and distribution in a steam-assisted gravity drainage (SAGD) reservoir are important factors that determine SAGD performance and strategies of positioning horizontal well-pairs. It has been confirmed that sandy-shale formations are usually very sandy and discontinuous; therefore, they are expected to be permeable to varying degrees during SAGD operations. This is completely different from the interbedded shales that have extremely low permeability and can be considered as impermeable.

Analysis of stress state change and anisotropic permeability variation in the sandy-shale requires conducting coupled simulation of geomechanics and thermal reservoir flow. Numerical modelling of the coupled processes is historically carried out in the areas of geomechanics modelling and the reservoir simulation. Gutierrez and Lewis(1) extend Biot's theory to multi-phase fluid flow in deformable porous media. Based on their formulation, they conclude that the coupling between the geomechanics and the multi-phase flow occurs simultaneously. Thus, fully coupled system equations of deformations, multi-phase flow and heat transfer should be solved simultaneously.