Impact of genetic variation in SORCS1 on memory retention

Objective

We previously reported that genetic variants in SORCS1 increase the risk of AD, that over-expression of SorCS1 reduces γ-secretase activity and Aβ levels, and that SorCS1 suppression increases γ-secretase processing of APP and Aβ levels. We now explored the effect of variation in SORCS1 on memory.

Methods

We explored associations between SORCS1-SNPs and memory retention in the NIA-LOAD case control dataset (162 cases,670 controls) and a cohort of Caribbean Hispanics (549 cases,544 controls) using single marker and haplotype analyses.

Results

Three SNPs in intron 1, were associated with memory retention in the NIA-LOAD dataset or the Caribbean Hispanic dataset (rs10884402(A allele:β = −0.15,p = 0.008), rs7078098(C allele:β = 0.18,p = 0.007) and rs950809(C allele:β = 0.17,p = 0.008)) and all three SNPs were significant in a meta-analysis of both datasets (0.002ConclusionsVariation in intron 1 in SORCS1 is associated with memory changes in AD.     

Health facility characteristics and their relationship to coverage of PMTCT of HIV services across four African countries: the PEARL study

Background

Health facility characteristics associated with effective prevention of mother-to-child transmission of HIV (PMTCT) coverage in sub-Saharan are poorly understood.

Methodology/Principal Findings

We conducted surveys in health facilities with active PMTCT services in Cameroon, Cote d''Ivoire, South Africa, and Zambia. Data was compiled via direct observation and exit interviews. We constructed composite scores to describe provision of PMTCT services across seven topical areas: antenatal quality, PMTCT quality, supplies available, patient satisfaction, patient understanding of medication, and infrastructure quality. Pearson correlations and Generalized Estimating Equations (GEE) to account for clustering of facilities within countries were used to evaluate the relationship between the composite scores, total time of visit and select individual variables with PMTCT coverage among women delivering.Between July 2008 and May 2009, we collected data from 32 facilities; 78% were managed by the government health system. An opt-out approach for HIV testing was used in 100% of facilities in Zambia, 63% in Cameroon, and none in Côte d''Ivoire or South Africa. Using Pearson correlations, PMTCT coverage (median of 55%, (IQR: 33–68) was correlated with PMTCT quality score (rho = 0.51; p = 0.003); infrastructure quality score (rho = 0.43; p = 0.017); time spent at clinic (rho = 0.47; p = 0.013); patient understanding of medications score (rho = 0.51; p = 0.006); and patient satisfaction quality score (rho = 0.38; p = 0.031). PMTCT coverage was marginally correlated with the antenatal quality score (rho = 0.304; p = 0.091). Using GEE adjustment for clustering, the, antenatal quality score became more strongly associated with PMTCT coverage (p<0.001) and the PMTCT quality score and patient understanding of medications remained marginally significant.

Conclusions/Results

We observed a positive relationship between an antenatal quality score and PMTCT coverage but did not identify a consistent set of variables that predicted PMTCT coverage.     

Linking oviposition site choice to offspring fitness in Aedes aegypti: consequences for targeted larval control of dengue vectors

Background

Current Aedes aegypti larval control methods are often insufficient for preventing dengue epidemics. To improve control efficiency and cost-effectiveness, some advocate eliminating or treating only highly productive containers. The population-level outcome of this strategy, however, will depend on details of Ae. aegypti oviposition behavior.

Methodology/Principal Findings

We simultaneously monitored female oviposition and juvenile development in 80 experimental containers located across 20 houses in Iquitos, Peru, to test the hypothesis that Ae. aegypti oviposit preferentially in sites with the greatest potential for maximizing offspring fitness. Females consistently laid more eggs in large vs. small containers (β = 9.18, p<0.001), and in unmanaged vs. manually filled containers (β = 5.33, p<0.001). Using microsatellites to track the development of immature Ae. aegypti, we found a negative correlation between oviposition preference and pupation probability (β = −3.37, p<0.001). Body size of emerging adults was also negatively associated with the preferred oviposition site characteristics of large size (females: β = −0.19, p<0.001; males: β = −0.11, p = 0.002) and non-management (females: β = −0.17, p<0.001; males: β = −0.11, p<0.001). Inside a semi-field enclosure, we simulated a container elimination campaign targeting the most productive oviposition sites. Compared to the two post-intervention trials, egg batches were more clumped during the first pre-intervention trial (β = −0.17, P<0.001), but not the second (β = 0.01, p = 0.900). Overall, when preferred containers were unavailable, the probability that any given container received eggs increased (β = 1.36, p<0.001).

Conclusions/Significance

Ae. aegypti oviposition site choice can contribute to population regulation by limiting the production and size of adults. Targeted larval control strategies may unintentionally lead to dispersion of eggs among suitable, but previously unoccupied or under-utilized containers. We recommend integrating targeted larval control measures with other strategies that leverage selective oviposition behavior, such as luring ovipositing females to gravid traps or egg sinks.     

Zinc-alpha 2-glycoprotein gene expression in adipose tissue is related with insulin resistance and lipolytic genes in morbidly obese patients

Objective

Zinc-α₂ glycoprotein (ZAG) stimulates lipid loss by adipocytes and may be involved in the regulation of adipose tissue metabolism. However, to date no studies have been made in the most extreme of obesity. The aims of this study are to analyze ZAG expression levels in adipose tissue from morbidly obese patients, and their relationship with lipogenic and lipolytic genes and with insulin resistance (IR).

Methods

mRNA expression levels of PPARγ, IRS-1, IRS-2, lipogenic and lipolytic genes and ZAG were quantified in visceral (VAT) and subcutaneous adipose tissue (SAT) of 25 nondiabetic morbidly obese patients, 11 with low IR and 14 with high IR. Plasma ZAG was also analyzed.

Results

The morbidly obese patients with low IR had a higher VAT ZAG expression as compared with the patients with high IR (p = 0.023). In the patients with low IR, the VAT ZAG expression was greater than that in SAT (p = 0.009). ZAG expression correlated between SAT and VAT (r = 0.709, p<0.001). VAT ZAG expression was mainly predicted by insulin, HOMA-IR, plasma adiponectin and expression of adiponectin and ACSS2. SAT ZAG expression was only predicted by expression of ATGL.

Conclusions

ZAG could be involved in modulating lipid metabolism in adipose tissue and is associated with insulin resistance. These findings suggest that ZAG may be a useful target in obesity and related disorders, such as diabetes.     

FcγRIIIa expression on monocytes in rheumatoid arthritis: role in immune-complex stimulated TNF production and non-response to methotrexate therapy

Objective

The expression of FcγRIIIa/CD16 may render monocytes targets for activation by IgG-containing immune complexes (IC). We investigated whether FcγRIIIa/CD16 was upregulated in rheumatoid arthritis (RA), associated with TNF production in response to IC-stimulation, and if this predicted response to methotrexate therapy.

Methods

FcγRIIIa/CD16 expression on CD14^low and CD14⁺⁺ monocytes was measured by flow cytometry in healthy controls and RA patients (early and long-standing disease). Intracellular TNF-staining was carried out after in vitro LPS or heat-aggregated immunoglobulin (HAG) activation. FcγRIIIa/CD16 expression pre- and post-steroid/methotrexate treatment was examined.

Results

Increased FcγRIIIa/CD16 expression on CD14⁺⁺ monocytes in long-standing RA patients compared to controls was demonstrated (p = 0.002) with intermediate levels in early-RA patients. HAG-induced TNF-production in RA patients was correlated with the percentage of CD14⁺⁺ monocytes expressing FcγRIIIa/CD16 (p<0.001). The percentage of CD14⁺⁺ monocytes expressing FcγRIIIa/CD16 at baseline in early DMARD-naïve RA patients was negatively correlated with DAS28-ESR improvement 14-weeks post-methotrexate therapy (p = 0.003) and was significantly increased in EULAR non-responders compared to moderate (p = 0.01) or good responders (p = 0.003). FcγRIIIa/CD16 expression was not correlated with age, presence of systemic inflammation or autoantibody titers.

Conclusion

Increased FcγRIIIa/CD16 expression on CD14⁺⁺ monocytes in RA may result in a cell that has increased responsiveness to IC-stimulation. This monocyte subset may contribute to non-response to methotrexate therapy.     

Differential combination of cytokine and interferon- γ +874 T/A polymorphisms determines disease severity in pulmonary tuberculosis

Background

Mycobacterium tuberculosis infects nearly 1/3 of the world population and this reservoir forms the largest pool from which new cases arise. Among the cytokines, IFN-γ is a key determinant in protection against tuberculosis. Single nucleotide polymorphisms (SNPs) in IFN-γ gene (+874 T/A) which determine TT high (^hi), AA low (^lo) and TA intermediate (^int) responder phenotypes have shown variable associations with tuberculosis disease outcome in different ethnic populations. The objective of the current study was to analyze IFN-γ gene combinations with other IFN-γ regulating cytokine genes (IL-10, TNF –α, IL-6) to see the effect of gene- combinations on disease severity outcome in pulmonary tuberculosis.

Methods and Findings

Study groups comprised of pulmonary TB patients stratified according to lung tissue involvement into mild (Pmd = 74) or advance (Pad = 23) lung disease and compared with healthy controls (TBNA = 166). Genotype analysis was carried out using amplification refractory mutation system-PCR (ARMS-PCR). IFN-γ gene (+874 T/A) functional SNP combinations in TNFα (−308 G/A), IL-10 (−1082 A/G) and IL-6 (−174 G/C) were analyzed. Single gene analysis (Pearson χ²) showed a dominant association of IFN-γ TT ^hi genotype (p = 0.001) and T allele (p = 0.001) with mild disease. IFN-γ ^lo -IL-10 ^lo genotype combination was associated with advanced disease (p = 0.002). IFN-γ ^hi –IL-6 ^hi combination was associated with mild disease (p = 0.0005) while IFN-γ ^lo –IL-6 ^int was associated with protection against both forms of pulmonary disease (p = 0.002).

Conclusion

Our results show that a limited number of IFN-γ gene combinations with other cytokine functional SNPs determine the outcome of disease severity in tuberculosis.     

Bile acid sequestration reduces plasma glucose levels in db/db mice by increasing its metabolic clearance rate

Aims/Hypothesis

Bile acid sequestrants (BAS) reduce plasma glucose levels in type II diabetics and in murine models of diabetes but the mechanism herein is unknown. We hypothesized that sequestrant-induced changes in hepatic glucose metabolism would underlie reduced plasma glucose levels. Therefore, in vivo glucose metabolism was assessed in db/db mice on and off BAS using tracer methodology.

Methods

Lean and diabetic db/db mice were treated with 2% (wt/wt in diet) Colesevelam HCl (BAS) for 2 weeks. Parameters of in vivo glucose metabolism were assessed by infusing [U-¹³C]-glucose, [2-¹³C]-glycerol, [1-²H]-galactose and paracetamol for 6 hours, followed by mass isotopologue distribution analysis, and related to metabolic parameters as well as gene expression patterns.

Results

Compared to lean mice, db/db mice displayed an almost 3-fold lower metabolic clearance rate of glucose (p = 0.0001), a ∼300% increased glucokinase flux (p = 0.001) and a ∼200% increased total hepatic glucose production rate (p = 0.0002). BAS treatment increased glucose metabolic clearance rate by ∼37% but had no effects on glucokinase flux nor total hepatic or endogenous glucose production. Strikingly, BAS-treated db/db mice displayed reduced long-chain acylcarnitine content in skeletal muscle (p = 0.0317) but not in liver (p = 0.189). Unexpectedly, BAS treatment increased hepatic FGF21 mRNA expression 2-fold in lean mice (p = 0.030) and 3-fold in db/db mice (p = 0.002).

Conclusions/Interpretation

BAS induced plasma glucose lowering in db/db mice by increasing metabolic clearance rate of glucose in peripheral tissues, which coincided with decreased skeletal muscle long-chain acylcarnitine content.     

Effects of Insulin Therapy on Myocardial Lipid Content and Cardiac Geometry in Patients with Type-2 Diabetes Mellitus

Aims/Hypothesis

Recent evidence suggests a link between myocardial steatosis and diabetic cardiomyopathy. Insulin, as a lipogenic and growth-promoting hormone, might stimulate intramyocardial lipid (MYCL) deposition and hypertrophy. Therefore, the aim of the present study was to investigate the short-term effects of insulin therapy (IT) on myocardial lipid content and morphology in patients with T2DM.

Methods

Eighteen patients with T2DM were recruited (age 56±2 years; HbA1c: 10.5±0.4%). In 10 patients with insufficient glucose control under oral medication IT was initiated due to secondary failure of oral glucose lowering therapy (IT-group), while 8 individuals did not require additional insulin substitution (OT-group). In order to assess MYCL and intrahepatic lipid (IHLC) content as well as cardiac geometry and function magnetic resonance spectroscopy (MRS) and imaging (MRI) examinations were performed at baseline (IT and OT) and 10 days after initiation of IT. Follow up measurements took place 181±49 days after IT.

Results

Interestingly, basal MYCLs were 50% lower in IT- compared to OT-group (0.41±0.12 vs. 0.80±0.11% of water signal; p = 0.034). After 10 days of IT, an acute 80%-rise in MYCL (p = 0.008) was observed, while IHLC did not change. Likewise, myocardial mass (+13%; p = 0.004), wall thickness in end-diastole (+13%; p = 0.030) and concentricity, an index of cardiac remodeling, increased (+28%; p = 0.026). In the long-term MYCL returned to baseline, while IHCL significantly decreased (−31%; p = 0.000). No acute changes in systolic left ventricular function were observed.

Conclusions/Interpretation

The initiation of IT in patients with T2DM was followed by an acute rise in MYCL concentration and myocardial mass.     

The sodium iodide symporter (NIS) and potential regulators in normal, benign and malignant human breast tissue

Introduction

The presence, relevance and regulation of the Sodium Iodide Symporter (NIS) in human mammary tissue remains poorly understood. This study aimed to quantify relative expression of NIS and putative regulators in human breast tissue, with relationships observed further investigated in vitro.

Methods

Human breast tissue specimens (malignant n = 75, normal n = 15, fibroadenoma n = 10) were analysed by RQ-PCR targeting NIS, receptors for retinoic acid (RARα, RARβ), oestrogen (ERα), thyroid hormones (THRα, THRβ), and also phosphoinositide-3-kinase (PI3K). Breast cancer cells were treated with Retinoic acid (ATRA), Estradiol and Thyroxine individually and in combination followed by analysis of changes in NIS expression.

Results

The lowest levels of NIS were detected in normal tissue (Mean(SEM) 0.70(0.12) Log₁₀ Relative Quantity (RQ)) with significantly higher levels observed in fibroadenoma (1.69(0.21) Log₁₀RQ, p<0.005) and malignant breast tissue (1.18(0.07) Log₁₀RQ, p<0.05). Significant positive correlations were observed between human NIS and ERα (r = 0.22, p<0.05) and RARα (r = 0.29, p<0.005), with the strongest relationship observed between NIS and RARβ (r = 0.38, p<0.0001). An inverse relationship between NIS and PI3K expression was also observed (r = −0.21, p<0.05). In vitro, ATRA, Estradiol and Thyroxine individually stimulated significant increases in NIS expression (range 6–16 fold), while ATRA and Thyroxine combined caused the greatest increase (range 16–26 fold).

Conclusion

Although NIS expression is significantly higher in malignant compared to normal breast tissue, the highest level was detected in fibroadenoma. The data presented supports a role for retinoic acid and estradiol in mammary NIS regulation in vivo, and also highlights potential thyroidal regulation of mammary NIS mediated by thyroid hormones.     

Cigarette smoke extract (CSE) delays NOD2 expression and affects NOD2/RIPK2 interactions in intestinal epithelial cells

Background

Genetic and environmental factors influence susceptibility to Crohn''s disease (CD): NOD2 is the strongest individual genetic determinant and smoking the best-characterised environmental factor. Carriage of NOD2 mutations predispose to small-intestinal, stricturing CD, a phenotype also associated with smoking. We hypothesised that cigarette smoke extract (CSE) altered NOD2 expression and function in intestinal epithelial cells.

Methods and Findings

Intestinal epithelial cell-lines (SW480, HT29, HCT116) were stimulated with CSE and nicotine (to mimic smoking) ±TNFα (to mimic inflammation). NOD2 expression was measured by qRT-PCR and western blotting; NOD2-RIPK2 interactions by co-immunoprecipitation (CoIP); nuclear NFκB-p65 by ELISA; NFκB activity by luciferase reporter assays and chemokines (CCL20, IL8) in culture supernatants by ELISA. In SW480 and HT29 cells the TNFα-induced NOD2 expression at 4 hours was reduced by CSE (p = 0.0226), a response that was dose-dependent (p = 0.003) and time-dependent (p = 0.0004). Similar effects of CSE on NOD2 expression were seen in cultured ileal biopsies from healthy individuals. In SW480 cells CSE reduced TNFα-induced NFκB-p65 translocation at 15 minutes post-stimulation, upstream of NOD2. Levels of the NOD2-RIPK2 complex were no different at 8 hours post-stimulation with combinations of CSE, nicotine and TNFα, but at 18 hours it was increased in cells stimulated with TNFα+CSE but decreased with TNFα alone (p = 0.0330); CSE reduced TNFα-induced NFκB activity (p = 0.0014) at the same time-point. At 24 hours, basal CCL20 and IL8 (p<0.001 for both) and TNFα-induced CCL20 (p = 0.0330) production were decreased by CSE. CSE also reduced NOD2 expression, CCL20 and IL8 production seen with MDP-stimulation of SW480 cells pre-treated with combinations of TNFα and CSE.

Conclusions

CSE delayed TNFα-induced NOD2 mRNA expression and was associated with abnormal NOD2/RIPK2 interaction, reduced NFκB activity and decreased chemokine production. These effects may be involved in the pathogenesis of small-intestinal CD and may have wider implications for the effects of smoking in NOD2-mediated responses.     

Effect of genetic variation in STXBP5 and STX2 on von Willebrand factor and bleeding phenotype in type 1 von Willebrand disease patients

Background

In type 1 von Willebrand Disease (VWD) patients, von Willebrand Factor (VWF) levels and bleeding symptoms are highly variable. Recently, the association between genetic variations in STXBP5 and STX2 with VWF levels has been discovered in the general population. We assessed the relationship between genetic variations in STXBP5 and STX2, VWF levels, and bleeding phenotype in type 1 VWD patients.

Methods

In 158 patients diagnosed with type 1 VWD according to the current ISTH guidelines, we genotyped three tagging-SNPs in STXBP5 and STX2 and analyzed their relationship with VWF:Ag levels and the severity of the bleeding phenotype, as assessed by the Tosetto bleeding score.

Results

In STX2, rs7978987 was significantly associated with VWF:Ag levels (bèta-coefficient (β) = −0.04 IU/mL per allele, [95%CI −0.07;−0.001], p = 0.04) and VWF:CB activity (β = −0.12 IU/mL per allele, [95%CI −0.17;−0.06], p<0.0001). For rs1039084 in STXBP5 a similar trend with VWF:Ag levels was observed: (β = −0.03 IU/mL per allele [95% CI −0.06;0.003], p = 0.07). In women, homozygous carriers of the minor alleles of both SNPs in STXBP5 had a significantly higher bleeding score than homozygous carriers of the major alleles. (Rs1039084 p = 0.01 and rs9399599 p = 0.02).

Conclusions

Genetic variation in STX2 is associated with VWF:Ag levels in patients diagnosed with type 1 VWD. In addition, genetic variation in STXBP5 is associated with bleeding phenotype in female VWD patients. Our findings may partly explain the variable VWF levels and bleeding phenotype in type 1 VWD patients.     

Urinary podocyte-associated mRNA profile in various stages of diabetic nephropathy

Background

Podocyte injury and subsequent excretion in urine play a crucial role in the pathogenesis and progression of diabetic nephropathy (DN). Quantification of messenger RNA (mRNA) expression in urinary sediment by real-time PCR is emerging as a noninvasive method of screening DN-associated biomarkers. We hypothesized that the urinary mRNA profile of podocyte-associated molecules may provide important clinical insight into the different stages of diabetic nephropathy.

Methods

DN patients (N = 51) and healthy controls (N = 13) were enrolled in this study. DN patients were divided into a normoalbuminuria group (UAE<30 mg/g, n = 17), a microalbuminuria group (UAE 30∼300 mg/g, n = 15), and a macroalbuminuria group (UAE>300 mg/g, n = 19), according to their urinary albumin excretion (UAE). Relative mRNA abundance of synaptopodin, podocalyxin, CD2-AP, α-actin4, and podocin were quantified, and correlations between target mRNAs and clinical parameters were examined.

Results

The urinary mRNA levels of all genes studied were significantly higher in the DN group compared with controls (p<0.05), and mRNA levels increased with DN progression. Urinary mRNA levels of all target genes positively correlated with both UAE and BUN. The expression of podocalyxin, CD2-AP, α-actin4, and podocin mRNA correlated with serum creatinine (r = 0.457, p = 0.001; r = 0.329, p = 0.01; r = 0.286, p = 0.021; r = 0.357, p = 0.006, respectively). Furthermore, podocalyxin mRNA was found to negatively correlate with eGFR (r = −0.349, p = 0.01).

Conclusion

The urinary mRNA profiles of synaptopodin, podocalyxin, CD2-AP, α-actin4, and podocin were found to increase with the progression of DN, which suggested that quantification of podocyte-associated molecules will be useful biomarkers of DN.     

Absence of birth-weight lowering effect of ADCY5 and near CCNL, but association of impaired glucose-insulin homeostasis with ADCY5 in Asian Indians

Background

A feature of the Asian Indian phenotype is low birth weight with increased adult type 2 diabetes risk. Most populations show consistent associations between low birth weight and adult type 2 diabetes. Recently, two birth weight-lowering loci on chromosome 3 (near CCNL1 and ADCY5) were identified in a genome-wide association study, the latter of which is also a type 2 diabetes locus. We therefore tested the impact of these genetic variants on birth weight and adult glucose/insulin homeostasis in a large Indian birth cohort.

Methodology/Principal Findings

Adults (n = 2,151) enrolled in a birth cohort (established 1969-73) were genotyped for rs900400 (near CCNL1) and rs9883204 (ADCY5). Associations were tested for birth weight, anthropometry from infancy to adulthood, and type 2 diabetes related glycemic traits. The average birth weight in this population was 2.79±0.47 kg and was not associated with genetic variation in CCNL1 (p = 0.87) or ADCY5 (p = 0.54). Allele frequencies for the ‘birth weight-lowering’ variants were similar compared with Western populations. There were no significant associations with growth or adult weight. However, the ‘birth weight-lowering’ variant of ADCY5 was associated with modest increase in fasting glucose (β 0.041, p = 0.027), 2-hours glucose (β 0.127, p = 0.019), and reduced insulinogenic index (β -0.106, p = 0.050) and 2-hour insulin (β -0.058, p = 0.010).

Conclusions

The low birth weight in Asian Indians is not even partly explained by genetic variants near CCNL1 and ADCY5 which implies that non-genetic factors may predominate. However, the ‘birth-weight-lowering’ variant of ADCY5 was associated with elevated glucose and decreased insulin response in early adulthood which argues for a common genetic cause of low birth weight and risk of type 2 diabetes.     

Soluble beta-amyloid precursor protein is related to disease progression in amyotrophic lateral sclerosis

Background

Biomarkers of disease progression in amyotrophic lateral sclerosis (ALS) could support the identification of beneficial drugs in clinical trials. We aimed to test whether soluble fragments of beta-amyloid precursor protein (sAPPα and sAPPß) correlated with clinical subtypes of ALS and were of prognostic value.

Methodology/Principal Findings

In a cross-sectional study including patients with ALS (N = 68) with clinical follow-up data over 6 months, Parkinson''s disease (PD, N = 20), and age-matched controls (N = 40), cerebrospinal fluid (CSF) levels of sAPPα a, sAPPß and neurofilaments (NfH^SMI35) were measured by multiplex assay, Progranulin by ELISA. CSF sAPPα and sAPPß levels were lower in ALS with a rapidly-progressive disease course (p = 0.03, and p = 0.02) and with longer disease duration (p = 0.01 and p = 0.01, respectively). CSF NfH^SMI35 was elevated in ALS compared to PD and controls, with highest concentrations found in patients with rapid disease progression (p<0.01). High CSF NfH^SMI3 was linked to low CSF sAPPα and sAPPß (p = 0.001, and p = 0.007, respectively). The ratios CSF NfH^SMI35/CSF sAPPα,-ß were elevated in patients with fast progression of disease (p = 0.002 each). CSF Progranulin decreased with ongoing disease (p = 0.04).

Conclusions

This study provides new CSF candidate markers associated with progression of disease in ALS. The data suggest that a deficiency of cellular neuroprotective mechanisms (decrease of sAPP) is linked to progressive neuro-axonal damage (increase of NfH^SMI35) and to progression of disease.     

Augmented atherogenesis in LDL receptor deficient mice lacking both macrophage ABCA1 and ApoE

Aim

ABCA1 protects against atherosclerosis by facilitating cholesterol efflux from macrophage foam cells in the arterial wall to extracellular apolipoprotein (apo) A-I. In contrast to apoA-I, apoE is secreted by macrophages and can, like apoA-I, induce ABCA1-mediated cholesterol efflux. Yet, the combined effect of macrophage ABCA1 and apoE on lesion development is unexplored.

Methods and Results

LDL receptor knockout (KO) mice were transplanted with bone marrow from ABCA1/apoE double KO (dKO) mice, their respective single KO''s, and wild-type (WT) controls and were challenged with a high-fat/high-cholesterol diet for 9 weeks. In vitro cholesterol efflux experiments showed no differences between ABCA1 KO and dKO macrophages. The serum non-HDL/HDL ratio in dKO transplanted mice was 1.7-fold and 2.4-fold (p<0.01) increased compared to WT and ABCA1 KO transplanted mice, respectively. The atherosclerotic lesion area in dKO transplanted animals (650±94×10³ µm²), however, was 1.9-fold (p<0.01) and 1.6-fold (p<0.01) increased compared to single knockouts (ABCA1 KO: 341±20×10³ µm²; apoE KO: 402±78×10³ µm², respectively) and 3.1-fold increased (p<0.001) compared to WT (211±20×10³ µm²). When normalized for serum cholesterol exposure, macrophage ABCA1 and apoE independently protected against atherosclerotic lesion development (p<0.001). Moreover, hepatic expression levels of TNFα and IL-6 were highly induced in dKO transplanted animals (3.0-fold; p<0.05, and 4.3-fold; p<0.001, respectively). In agreement, serum IL-6 levels were also enhanced in ABCA1 KO transplanted mice (p<0.05) and even further enhanced in dKO transplanted animals (3.1-fold as compared to ABCA1 KO transplanted animals; p<0.05).

Conclusions

Combined deletion of macrophage ABCA1 and apoE results in a defect in cholesterol efflux and, compared to ABCA1 KO transplanted mice, elevated serum total cholesterol levels. Importantly, these mice also suffer from enhanced systemic and hepatic inflammation, together resulting in the observed augmented atherosclerotic lesion development.     

Reduced expression of transcription factor AP-2α is associated with gastric adenocarcinoma prognosis

Background

This study aims to investigate the expression and prognostic significance of activator protein 2α (AP-2α) in gastric adenocarcinoma.

Methodology/Principal Findings

AP-2α expression was analyzed using real-time quantitative PCR (RT-qPCR), western blotting, and immunohistochemical staining methods on tissue samples from a consecutive series of 481 gastric adenocarcinoma patients who underwent resections between 2003 and 2006. The relationship between AP-2α expression, clinicopathological factors, and patient survival was investigated. RT- qPCR results showed that the expression of AP-2α mRNA was reduced in tumor tissue samples, compared with expression in matched adjacent non-tumor tissue samples (P = 0.009); this finding was confirmed by western blotting analysis (P = 0.012). Immunohistochemical staining data indicated that AP-2α expression was significantly decreased in 196 of 481 (40.7%) gastric adenocarcinoma cases; reduced AP-2α expression was also observed in patients with poorly differentiated tumors (P = 0.001) and total gastric carcinomas (P = 0.002), as well as in patients who underwent palliative tumor resection (P = 0.004). Additionally, reduced expression of AP-2α was more commonly observed in tumors that were staged as T4a/b (P = 0.018), N3 (P = 0.006), and M1 (P = 0.008). Kaplan-Meier survival curves revealed that reduced expression of AP-2α was associated with poor prognosis in gastric adenocarcinoma patients (P<0.001). Multivariate Cox analysis identified AP-2α expression as an independent prognostic factor for overall survival (HR = 1.512, 95% CI = 1.127–2.029, P = 0.006).

Conclusions/Significance

Our data suggest that AP-2α plays an important role in tumor progression and that reduced AP-2α expression independently predicts an unfavorable prognosis in gastric adenocarcinoma patients.     

Tumor site immune markers associated with risk for subsequent basal cell carcinomas

Background

Basal cell carcinoma (BCC) tumors are the most common skin cancer and are highly immunogenic.

Objective

The goal of this study was to assess how immune-cell related gene expression in an initial BCC tumor biopsy was related to the appearance of subsequent BCC tumors.

Materials and Methods

Levels of mRNA for CD3ε (a T-cell receptor marker), CD25 (the alpha chain of the interleukin (IL)-2 receptor expressed on activated T-cells and B-cells), CD68 (a marker for monocytes/macrophages), the cell surface glycoprotein intercellular adhesion molecule-1 (ICAM-1), the cytokine interferon-γ (IFN-γ) and the anti-inflammatory cytokine IL-10 were measured in BCC tumor biopsies from 138 patients using real-time PCR.

Results

The median follow-up was 26.6 months, and 61% of subjects were free of new BCCs two years post-initial biopsy. Patients with low CD3ε CD25, CD68, and ICAM-1 mRNA levels had significantly shorter times before new tumors were detected (p = 0.03, p = 0.02, p = 0.003, and p = 0.08, respectively). Furthermore, older age diminished the association of mRNA levels with the appearance of subsequent tumors.

Conclusions

Our results show that levels of CD3ε, CD25, CD68, and ICAM-1 mRNA in BCC biopsies may predict risk for new BCC tumors.     

Right heart structural changes are independently associated with exercise capacity in non-severe COPD

Background

Pulmonary hypertension (PH) occurs frequently and results in functional limitation in advanced COPD. Data regarding the functional consequence of PH in less severe COPD are limited. Whether echocardiographic evidence of right sided heart pathology is associated with functional outcomes in patients with non-severe COPD is unknown.

Methods

We evaluated pulmonary function, six minute walk distance, and echocardiography in 74 consecutive patients with non-severe COPD. We performed multivariable linear regression to evaluate the association between right heart echocardiographic parameters and six minute walk distance adjusting for lung function, age, sex, race, and BMI.

Main Results

The mean six minute walk distance was 324±106 meters. All subjects had preserved left ventricular (LV) systolic function (LV ejection fraction 62.3%±6.1%). 54.1% had evidence of some degree of diastolic dysfunction. 17.6% of subjects had evidence of right ventricular enlargement and 36.5% had right atrial enlargement. In univariate analysis RV wall thickness (β = −68.6; p = 0.002), log right atrial area (β = −297.9; p = 0.004), LV mass index (β = −1.3; p = 0.03), E/E'' ratio (β = −5.5; p = 0.02), and degree of diastolic dysfunction (β = −42.8; p = 0.006) were associated with six minute walk distance. After adjustment for co-variables, the associations between right atrial area (log right atrial area β = −349.8; p = 0.003) and right ventricular wall thickness (β = −43.8; p = 0.04) with lower six minute walk distance remained significant independent of forced expiratory volume in one second (FEV1). LV mass index, E/E'' ratio, and degree of diastolic dysfunction were not independent predictors of six minute walk distance.

Conclusion

In patients with non-severe COPD right sided cardiac structural changes are associated with lower six minute walk distance independent of lung function. These findings may indicate that echocardiographic evidence of pulmonary hypertension is present in patients with non-severe COPD and has important functional consequences.