Protein Corona Sensor Array Nanosystem for Detection of Coronary Artery Disease

Coronary artery disease (CAD) is the most common type of heart disease and represents the leading cause of death in both men and women worldwide. Early detection of CAD is crucial for decreasing mortality, prolonging survival, and improving patient quality of life. Herein, a non-invasive is described, nanoparticle-based diagnostic technology which takes advantages of proteomic changes in the nano-bio interface for CAD detection. Nanoparticles (NPs) exposed to biological fluids adsorb on their surface a layer of proteins, the "protein corona" (PC). Pathological changes that alter the plasma proteome can directly result in changes in the PC. By forming disease-specific PCs on six NPs with varying physicochemical properties, a PC-based sensor array is developed for detection of CAD using specific PC pattern recognition. While the PC of a single NP may not provide the required specificity, it is reasoned that multivariate PCs across NPs with different surface chemistries, can provide the desirable information to selectively discriminate the condition under investigation. The results suggest that such an approach can detect CAD with an accuracy of 92.84%, a sensitivity of 87.5%, and a specificity of 82.5%. These new findings demonstrate the potential of PC-based sensor array detection systems for clinical use.

Dietary and supplemental intake of vitamins C and E is associated with altered DNA methylation in an epigenome-wide association study meta-analysis

BACKGROUND

Dietary intake of antioxidants such as vitamins C and E protect against oxidative stress, and may also be associated with altered DNA methylation patterns.

METHODS

We meta-analysed epigenome-wide association study (EWAS) results from 11,866 participants across eight population-based cohorts to evaluate the association between self-reported dietary and supplemental intake of vitamins C and E with DNA methylation. EWAS were adjusted for age, sex, BMI, caloric intake, blood cell type proportion, smoking status, alcohol consumption, and technical covariates. Significant results of the meta-analysis were subsequently evaluated in gene set enrichment analysis (GSEA) and expression quantitative trait methylation (eQTM) analysis.

RESULTS

In meta-analysis, methylation at 4,656 CpG sites was significantly associated with vitamin C intake at FDR ≤ 0.05. The most significant CpG sites associated with vitamin C (at FDR ≤ 0.01) were enriched for pathways associated with systems development and cell signalling in GSEA, and were associated with downstream expression of genes enriched in the immune response in eQTM analysis. Furthermore, methylation at 160 CpG sites was significantly associated with vitamin E intake at FDR ≤ 0.05, but GSEA and eQTM analysis of the top most significant CpG sites associated with vitamin E did not identify significant enrichment of any biological pathways investigated.

CONCLUSIONS

We identified significant associations of many CpG sites with vitamin C and E intake, and our results suggest that vitamin C intake may be associated with systems development and the immune response.

Epigenome-wide DNA methylation association study of circulating IgE levels identifies novel targets for asthma

BACKGROUND

Identifying novel epigenetic signatures associated with serum immunoglobulin E (IgE) may improve our understanding of molecular mechanisms underlying asthma and IgE-mediated diseases.

METHODS

We performed an epigenome-wide association study using whole blood from Framingham Heart Study (FHS; n = 3,471, 46% females) participants and validated results using the Childhood Asthma Management Program (CAMP; n = 674, 39% females) and the Genetic Epidemiology of Asthma in Costa Rica Study (CRA; n = 787, 41% females). Using the closest gene to each IgE-associated CpG, we highlighted biologically plausible pathways underlying IgE regulation and analyzed the transcription patterns linked to IgE-associated CpGs (expression quantitative trait methylation loci; eQTMs). Using prior UK Biobank summary data from genome-wide association studies of asthma and allergy, we performed Mendelian randomization (MR) for causal inference testing using the IgE-associated CpGs from FHS with methylation quantitative trait loci (mQTLs) as instrumental variables.

FINDINGS

We identified 490 statistically significant differentially methylated CpGs associated with IgE in FHS, of which 193 (39.3%) replicated in CAMP and CRA (FDR < 0.05). Gene ontology analysis revealed enrichment in pathways related to transcription factor binding, asthma, and other immunological processes. eQTM analysis identified 124 cis-eQTMs for 106 expressed genes (FDR < 0.05). MR in combination with drug-target analysis revealed CTSB and USP20 as putatively causal regulators of IgE levels (Bonferroni adjusted P < 7.94E-04) that can be explored as potential therapeutic targets.

INTERPRETATION

By integrating eQTM and MR analyses in general and clinical asthma populations, our findings provide a deeper understanding of the multidimensional inter-relations of DNA methylation, gene expression, and IgE levels.

FUNDING

US NIH/NHLBI grants: P01HL132825, K99HL159234. N01-HC-25195 and HHSN268201500001I.

Neurological and Psychiatric Manifestations of Long COVID-19 and Their [18F]FDG PET Findings: A Review

For more than two years, lingering sequalae of COVID-19 have been extensively investigated. Approximately 10% of individuals infected by COVID-19 have been found to experience long-term symptoms termed "long COVID-19". The neurological and psychiatric manifestations of long COVID-19 are of particular concern. While pathogenesis remains unclear, emerging imaging studies have begun to better elucidate certain pathological manifestation. Of specific interest is imaging with [18F]FDG PET which directly reflects cellular glycolysis often linked to metabolic and inflammatory processes. Seeking to understand the molecular basis of neurological features of long COVID-19, this review encompasses the most recent [18F]FDG PET literature in this area.

Integrative Mendelian randomization reveals the soluble receptor for advanced glycation end products as protective in relation to rheumatoid arthritis

Rheumatoid arthritis (RA) is a risk factor for atherosclerotic cardiovascular diseases (CVD). Given the critical roles of the immune system and inflammatory signals in the pathogenesis of CVD, we hypothesized that interrogation of CVD-related proteins using integrative genomics might provide new insights into the pathophysiology of RA. We utilized two-sample Mendelian randomization (MR) for causal inference between circulating protein levels and RA by incorporating genetic variants, followed by colocalization to characterize the causal associations. Genetic variants from three sources were obtained: those associated with 71 CVD-related proteins measured in nearly 7000 Framingham Heart Study participants, a published genome-wide association study (GWAS) of RA (19 234 cases, 61 565 controls), and GWAS of rheumatoid factor (RF) levels from the UK Biobank (n = 30 565). We identified the soluble receptor for advanced glycation end products (sRAGE), a critical inflammatory pathway protein, as putatively causal and protective for both RA (odds ratio per 1-standard deviation increment in inverse-rank normalized sRAGE level = 0.364; 95% confidence interval 0.342-0.385; P = 6.40 × 10-241) and RF levels (β [change in RF level per sRAGE increment] = - 1.318; SE = 0.434; P = 0.002). Using an integrative genomic approach, we highlight the AGER/RAGE axis as a putatively causal and promising therapeutic target for RA.

Transcriptome-wide association study of circulating IgE levels identifies novel targets for asthma and allergic diseases

Measurement of circulating immunoglobulin E (IgE) concentration is helpful for diagnosing and treating asthma and allergic diseases. Identifying gene expression signatures associated with IgE might elucidate novel pathways for IgE regulation. To this end, we performed a discovery transcriptome-wide association study to identify differentially expressed genes associated with circulating IgE levels in whole-blood derived RNA from 5,345 participants in the Framingham Heart Study across 17,873 mRNA gene-level transcripts. We identified 216 significant transcripts at a false discovery rate <0.05. We conducted replication using the meta-analysis of two independent external studies: the Childhood Asthma Management Program (n=610) and the Genetic Epidemiology of Asthma in Costa Rica Study (n=326); we then reversed the discovery and replication cohorts, which revealed 59 significant genes that replicated in both directions. Gene ontology analysis revealed that many of these genes were implicated in immune function pathways, including defense response, inflammatory response, and cytokine production. Mendelian randomization (MR) analysis revealed four genes (CLC, CCDC21, S100A13, and GCNT1) as putatively causal (p<0.05) regulators of IgE levels. GCNT1 (beta=1.5, p=0.01)-which is a top result in the MR analysis of expression in relation to asthma and allergic diseases-plays a role in regulating T helper type 1 cell homing, lymphocyte trafficking, and B cell differentiation. Our findings build upon prior knowledge of IgE regulation and provide a deeper understanding of underlying molecular mechanisms. The IgE-associated genes that we identified-particularly those implicated in MR analysis-can be explored as promising therapeutic targets for asthma and IgE-related diseases.

Cardiovascular disease protein biomarkers are associated with kidney function: The Framingham Heart Study

Background

Biomarkers common to chronic kidney disease (CKD) and cardiovascular disease (CVD) may reflect early impairments underlying both diseases.

Methods

We evaluated associations of 71 CVD-related plasma proteins measured in 2,873 Framingham Heart Study (FHS) Offspring cohort participants with cross-sectional continuous eGFR and with longitudinal change in eGFR from baseline to follow-up (ΔeGFR). We also evaluated the associations of the 71 CVD proteins with the following dichotomous secondary outcomes: prevalent CKD stage ≥3 (cross-sectional), new-onset CKD stage ≥3 (longitudinal), and rapid decline in eGFR (longitudinal). Proteins significantly associated with eGFR and ΔeGFR were subsequently validated in 3,951 FHS Third Generation cohort participants and were tested using Mendelian randomization (MR) analysis to infer putatively causal relations between plasma protein biomarkers and kidney function.

Results

In cross-sectional analysis, 37 protein biomarkers were significantly associated with eGFR at FDR<0.05 in the FHS Offspring cohort and 20 of these validated in the FHS Third Generation cohort at p<0.05/37. In longitudinal analysis, 27 protein biomarkers were significantly associated with ΔeGFR at FDR<0.05 and 12 of these were validated in the FHS Third Generation cohort at p<0.05/27. Additionally, 35 protein biomarkers were significantly associated with prevalent CKD, five were significantly associated with new-onset CKD, and 17 were significantly associated with rapid decline in eGFR. MR suggested putatively causal relations of melanoma cell adhesion molecule (MCAM; -0.011±0.003 mL/min/1.73m², p = 5.11E-5) and epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1; -0.006±0.002 mL/min/1.73m², p = 0.0001) concentration with eGFR.

Discussion/conclusions

Eight protein biomarkers were consistently associated with eGFR in cross-sectional and longitudinal analysis in both cohorts and may capture early kidney impairment; others were implicated in association and causal inference analyses. A subset of CVD protein biomarkers may contribute causally to the pathogenesis of kidney impairment and should be studied as targets for CKD treatment and early prevention.

An Integrative Genomic Strategy Identifies sRAGE as a Causal and Protective Biomarker of Lung Function

BACKGROUND

There are few clinically useful circulating biomarkers of lung function and lung disease. We hypothesized that genome-wide association studies (GWAS) of circulating proteins in conjunction with GWAS of pulmonary traits represents a clinically relevant approach to identifying causal proteins and therapeutically useful insights into mechanisms related to lung function and disease.

STUDY QUESTION

Can an integrative genomic strategy using GWAS of plasma soluble receptor for advanced glycation end-products (sRAGE) levels in conjunction with GWAS of lung function traits identify putatively causal relations of sRAGE to lung function?

STUDY DESIGN AND METHODS

Plasma sRAGE levels were measured in 6,861 Framingham Heart Study participants and GWAS of sRAGE was conducted to identify protein quantitative trait loci (pQTL), including cis-pQTL variants at the sRAGE protein-coding gene locus (AGER). We integrated sRAGE pQTL variants with variants from GWAS of lung traits. Colocalization of sRAGE pQTL variants with lung trait GWAS variants was conducted, and Mendelian randomization was performed using sRAGE cis-pQTL variants to infer causality of sRAGE for pulmonary traits. Cross-sectional and longitudinal protein-trait association analyses were conducted for sRAGE in relation to lung traits.

RESULTS

Colocalization identified shared genetic signals for sRAGE with lung traits. Mendelian randomization analyses suggested protective causal relations of sRAGE to several pulmonary traits. Protein-trait association analyses demonstrated higher sRAGE levels to be cross-sectionally and longitudinally associated with preserved lung function.

INTERPRETATION

sRAGE is produced by type I alveolar cells, and it acts as a decoy receptor to block the inflammatory cascade. Our integrative genomics approach provides evidence for sRAGE as a causal and protective biomarker of lung function, and the pattern of associations is suggestive of a protective role of sRAGE against restrictive lung physiology. We speculate that targeting the AGER/sRAGE axis may be therapeutically beneficial for the treatment and prevention of inflammation-related lung disease.

A genomic approach identifies sRAGE as a putatively causal protein for asthma

BACKGROUND

Asthma is a complex respiratory condition caused by environmental and genetic factors. Although lower concentrations of the anti-inflammatory protein sRAGE have been associated with asthma in humans and mouse models, it is uncertain whether sRAGE plays a causal role in asthma.

OBJECTIVE

We designed a two-stage study of sRAGE in relation to asthma with i) association analysis in FHS participants and ii) causal inference testing using MR.

METHODS

We measured plasma levels of sRAGE and performed cross-sectional analysis to examine the association between plasma sRAGE concentration and asthma status in 6,546 FHS participants. We then used sRAGE pQTLs derived from a GWAS of plasma sRAGE levels in ∼7,000 FHS participants with UK Biobank asthma GWAS in MR to consider sRAGE as a putatively causal protein for asthma. We also performed replication MR using an externally-derived sRAGE pQTL from the INTERVAL study. Last, we conducted colocalization using cis-pQTL variants at the AGER locus with variants from the UK Biobank asthma GWAS.

RESULTS

Association analysis revealed that each 1 SD increment in sRAGE concentration was associated with a 14% lower odds of asthma in FHS participants (95% CI 0.76-0.96). MR identified sRAGE as putatively causal for and protective against asthma based on self-reported (OR [per 1 SE increment in inverse rank-normalized sRAGE]=0.97, 95% CI 0.95-0.99; p=0.005) and doctor-diagnosed asthma (OR=0.97, 95% CI 0.95-0.99; p=0.011).

CONCLUSION

Through this genomic approach, we identified sRAGE as a putatively causal, biologically important, and protective protein in relation to asthma. Functional studies in cell/animal models are needed to confirm our findings.

Targeted delivery of protein arginine deiminase-4 inhibitors to limit arterial intimal NETosis and preserve endothelial integrity

AIMS

Recent evidence suggests that 'vulnerable plaques', which have received intense attention as underlying mechanism of acute coronary syndromes over the decades, actually rarely rupture and cause clinical events. Superficial plaque erosion has emerged as a growing cause of residual thrombotic complications of atherosclerosis in an era of increased preventive measures including lipid lowering, antihypertensive therapy, and smoking cessation. The mechanisms of plaque erosion remain poorly understood, and we currently lack validated effective diagnostics or therapeutics for superficial erosion. Eroded plaques have a rich extracellular matrix, an intact fibrous cap, sparse lipid, and few mononuclear cells, but do harbour neutrophil extracellular traps (NETs). We recently reported that NETs amplify and propagate the endothelial damage at the site of arterial lesions that recapitulate superficial erosion in mice. We showed that genetic loss of protein arginine deiminase (PAD)-4 function inhibited NETosis and preserved endothelial integrity. The current study used systemic administration of targeted nanoparticles to deliver an agent that limits NETs formation to probe mechanisms of and demonstrate a novel therapeutic approach to plaque erosion that limits endothelial damage.

METHODS AND RESULTS

We developed Collagen IV-targeted nanoparticles (Col IV NP) to deliver PAD4 inhibitors selectively to regions of endothelial cell sloughing and collagen IV-rich basement membrane exposure. We assessed the binding capability of the targeting ligand in vitro and evaluated Col IV NP targeting to areas of denuded endothelium in vivo in a mouse preparation that recapitulates features of superficial erosion. Delivery of the PAD4 inhibitor GSK484 reduced NET accumulation at sites of intimal injury and preserved endothelial continuity.

CONCLUSIONS

NPs directed to Col IV show selective uptake and delivery of their payload to experimentally eroded regions, illustrating their translational potential. Our results further support the role of PAD4 and NETs in superficial erosion.

Effects of Glucagon-Like Peptide-1 Analogue and Fibroblast Growth Factor 21 Combination on the Atherosclerosis-Related Process in a Type 2 Diabetes Mouse Model

BACKGROUND

Glucagon-like peptide-1 (GLP-1) analogues regulate glucose homeostasis and have anti-inflammatory properties, but cause gastrointestinal side effects. The fibroblast growth factor 21 (FGF21) is a hormonal regulator of lipid and glucose metabolism that has poor pharmacokinetic properties, including a short half-life. To overcome these limitations, we investigated the effect of a low-dose combination of a GLP-1 analogue and FGF21 on atherosclerosis-related molecular pathways.

METHODS

C57BL/6J mice were fed a high-fat diet for 30 weeks followed by an atherogenic diet for 10 weeks and were divided into four groups: control (saline), liraglutide (0.3 mg/kg/day), FGF21 (5 mg/kg/day), and low-dose combination treatment with liraglutide (0.1 mg/kg/day) and FGF21 (2.5 mg/kg/day) (n=6/group) for 6 weeks. The effects of each treatment on various atherogenesisrelated pathways were assessed.

RESULTS

Liraglutide, FGF21, and their low-dose combination significantly reduced atheromatous plaque in aorta, decreased weight, glucose, and leptin levels, and increased adiponectin levels. The combination treatment upregulated the hepatic uncoupling protein-1 (UCP1) and Akt1 mRNAs compared with controls. Matric mentalloproteinase-9 (MMP-9), monocyte chemoattractant protein-1 (MCP-1), and intercellular adhesion molecule-1 (ICAM-1) were downregulated and phosphorylated Akt (p-Akt) and phosphorylated extracellular signal-regulated kinase (p-ERK) were upregulated in liver of the liraglutide-alone and combination-treatment groups. The combination therapy also significantly decreased the proliferation of vascular smooth muscle cells. Caspase-3 was increased, whereas MMP-9, ICAM-1, p-Akt, and p-ERK1/2 were downregulated in the liraglutide-alone and combination-treatment groups.

CONCLUSION

Administration of a low-dose GLP-1 analogue and FGF21 combination exerts beneficial effects on critical pathways related to atherosclerosis, suggesting the synergism of the two compounds.

Analysis of the Human Plasma Proteome Using Multi-Nanoparticle Protein Corona for Detection of Alzheimer's Disease

As the population affected by Alzheimer's disease (AD) grows, so does the need for a noninvasive and accurate diagnostic tool. Current research reveals that AD pathogenesis begins as early as decades before clinical symptoms. The unique properties of nanoparticles (NPs) may be exploited to develop noninvasive diagnostics for early detection of AD. After exposure of NPs to biological fluids, the NP surface is altered by an unbiased but selective and reproducible adsorption of biomolecules commonly referred to as the biomolecular corona or protein corona (PC). The discovery that the plasma proteome may be differentially altered during health and disease leads to the concept of disease-specific PCs. Herein, the disease-specific PCs formed around NPs in a multi-NPs platform are employed to successfully identify subtle changes in plasma protein patterns and detect AD (>92% specificity and ≈100% sensitivity). Similar discrimination power is achieved using banked plasma samples from a cohort of patients several years prior to their diagnosis with AD. With the nanoplatform's analytic ability to analyze pathological proteomic changes into a disease-specific identifier, this promising, noninvasive technology with implications for early detection and intervention could benefit not only patients with AD but other diseases as well.

Effect of Fibroblast Growth Factor 21 on the Development of Atheromatous Plaque and Lipid Metabolic Profiles in an Atherosclerosis-Prone Mouse Model

Fibroblast growth factor 21 (FGF21) is a hormonal regulator of lipid and glucose metabolism. We aimed to investigate the effect of an FGF21 analogue (LY2405319) on the development of atherosclerosis and its associated parameters. ApoE^−/− mice were fed an atherogenic diet for 14 weeks and were randomly assigned to control (saline) or FGF21 (0.1 mg/kg) treatment group (n = 10/group) for 5 weeks. Plaque size in the aortic arch/valve areas and cardiovascular risk markers were evaluated in blood and tissues. The effects of FGF21 on various atherogenesis-related pathways were also assessed. Atherosclerotic plaque areas in the aortic arch/valve were significantly smaller in the FGF21 group than in controls after treatment. FGF21 significantly decreased body weight and glucose concentrations, and increased circulating adiponectin levels. FGF21 treatment alleviated insulin resistance and decreased circulating concentrations of triglycerides, which were significantly correlated with plaque size. FGF21 treatment reduced lipid droplets in the liver and decreased fat cell size and inflammatory cell infiltration in the abdominal visceral fat compared with the control group. The monocyte chemoattractant protein-1 levels were decreased and β-hydroxybutyrate levels were increased by FGF21 treatment. Uncoupling protein 1 expression in subcutaneous fat was greater and fat cell size in brown fat was smaller in the FGF21 group compared with controls. Administration of FGF21 showed anti-atherosclerotic effects in atherosclerosis-prone mice and exerted beneficial effects on critical atherosclerosis pathways. Improvements in inflammation and insulin resistance seem to be mechanisms involved in the mitigation of atherosclerosis by FGF21 therapy.

Biomedical applications of mRNA nanomedicine

As an attractive alternative to plasmid DNA, messenger RNA (mRNA) has recently emerged as a promising class of nucleic acid therapeutics for biomedical applications. Advances in addressing the inherent shortcomings of mRNA and in the development of nanoparticle-based delivery systems have prompted the development and clinical translation of mRNA-based medicines. In this review, we discuss the chemical modification strategies of mRNA to improve its stability, minimize immune responses, and enhance translational efficacy. We also highlight recent progress in nanoparticle-based mRNA delivery. Considerable attention is given to the increasingly widespread applications of mRNA nanomedicine in the biomedical fields of vaccination, protein-replacement therapy, gene editing, and cellular reprogramming and engineering.

Restoration of tumour-growth suppression in vivo via systemic nanoparticle-mediated delivery of PTEN mRNA

PTEN is a well-characterized tumour-suppressor gene that is lost or mutated in about half of metastatic castration-resistant prostate cancers and in many other human cancers. The restoration of functional PTEN as a treatment for prostate cancer has however proven difficult. Here, we show that PTEN mRNA can be reintroduced into PTEN-null prostate cancer cells in vitro and in vivo via its encapsulation in polymer-lipid hybrid nanoparticles coated with a poly(ethylene glycol) shell. The nanoparticles are stable in serum, elicit low toxicity, enable high PTEN mRNA transfection in prostate cancer cells, and lead to significant inhibition of tumour growth when delivered systemically in multiple mouse models of prostate cancer. We also show that the restoration of PTEN function in PTEN-null prostate cancer cells inhibits the PI3K-AKT pathway and enhances apoptosis. Our findings provide proof-of-principle evidence of the restoration of mRNA-based tumour suppression in vivo.

Effects of Lobeglitazone, a New Thiazolidinedione, on Osteoblastogenesis and Bone Mineral Density in Mice

BACKGROUND

Bone strength is impaired in patients with type 2 diabetes mellitus despite an increase in bone mineral density (BMD). Thiazolidinedione (TZD), a peroxisome proliferator activated receptor γ agonist, promotes adipogenesis, and suppresses osteoblastogenesis. Therefore, its use is associated with an increased risk of fracture. The aim of this study was to examine the in vitro and in vivo effects of lobeglitazone, a new TZD, on bone.

METHODS

MC3T3E1 and C3H10T1/2 cells were cultured in osteogenic medium and exposed to lobeglitazone (0.1 or 1 μM), rosiglitazone (0.4 μM), or pioglitazone (1 μM) for 10 to 14 days. Alkaline phosphatase (ALP) activity, Alizarin red staining, and osteoblast marker gene expression were analyzed. For in vivo experiments, 6-month-old C57BL/6 mice were treated with vehicle, one of two doses of lobeglitazone, rosiglitazone, or pioglitazone. BMD was assessed using a PIXImus2 instrument at the baseline and after 12 weeks of treatment.

RESULTS

As expected, in vitro experiments showed that ALP activity was suppressed and the mRNA expression of osteoblast marker genes RUNX2 (runt-related transcription factor 2) and osteocalcin was significantly attenuated after rosiglitazone treatment. By contrast, lobeglitazone at either dose did not inhibit these variables. Rosiglitazone-treated mice showed significantly accelerated bone loss for the whole bone and femur, but BMD did not differ significantly between the lobeglitazone-treated and vehicle-treated mice.

CONCLUSION

These findings suggest that lobeglitazone has no detrimental effects on osteoblast biology and might not induce side effects in the skeletal system.

Attenuation of carotid neointimal formation after direct delivery of a recombinant adenovirus expressing glucagon-like peptide-1 in diabetic rats

AIMS

Enhancement of glucagon-like peptide-1 (GLP-1) reduces glucose levels and preserves pancreatic β-cell function, but its effect against restenosis is unknown.

METHODS AND RESULTS

We investigated the effect of subcutaneous injection of exenatide or local delivery of a recombinant adenovirus expressing GLP-1 (rAd-GLP-1) into carotid artery, in reducing the occurrence of restenosis following balloon injury. As a control, we inserted β-galactosidase cDNA in the same vector (rAd-βGAL). Otsuka Long-Evans Tokushima rats were assigned to three groups (n = 12 each): (1) normal saline plus rAd-βGAL delivery (NS + rAd-βGAL), (2) exenatide plus rAd-βGAL delivery (Exenatide + rAd-βGAL), and (3) normal saline plus rAd-GLP-1 delivery (NS + rAd-GLP-1). Normal saline or exenatide were administered subcutaneously from 1 week before to 2 weeks after carotid injury. After 3 weeks, the NS + rAd-βGAL group showed the highest intima-media ratio (IMR; 3.73 ± 0.90), the exenatide + rAd-βGAL treatment was the next highest (2.80 ± 0.51), and NS + rAd-GLP-1 treatment showed the lowest IMR (1.58 ± 0.48, P < 0.05 vs. others). The proliferation and migration of vascular smooth muscle cells and monocyte adhesion were decreased significantly after rAd-GLP-1 treatment, showing the same overall patterns as the IMR. In injured vessels, the apoptosis was greater and MMP2 expression was less in the NS + rAd-GLP-1 than in the exenatide or rAd-βGAL groups. In vitro expressions of matrix metalloproteinases-2 and monocyte chemoattractant protein-1 and nuclear factor-kappa-B-p65 translocation were decreased more in the NS + rAd-GLP-1 group than in the other two groups (all P < 0.05).

CONCLUSION

Direct GLP-1 overexpression showed better protection against restenosis after balloon injury via suppression of vascular smooth muscle cell migration, increased apoptosis, and decreased inflammatory processes than systemic exenatide treatment. This has potential therapeutic implications for treating macrovascular complications in diabetes.

SREBP1c-CRY1 signalling represses hepatic glucose production by promoting FOXO1 degradation during refeeding

SREBP1c is a key lipogenic transcription factor activated by insulin in the postprandial state. Although SREBP1c appears to be involved in suppression of hepatic gluconeogenesis, the molecular mechanism is not thoroughly understood. Here we show that CRY1 is activated by insulin-induced SREBP1c and decreases hepatic gluconeogenesis through FOXO1 degradation, at least, at specific circadian time points. SREBP1c^−/− and CRY1^−/− mice show higher blood glucose than wild-type (WT) mice in pyruvate tolerance tests, accompanied with enhanced expression of PEPCK and G6Pase genes. CRY1 promotes degradation of nuclear FOXO1 by promoting its binding to the ubiquitin E3 ligase MDM2. Although SREBP1c fails to upregulate CRY1 expression in db/db mice, overexpression of CRY1 attenuates hyperglycaemia through reduction of hepatic FOXO1 protein and gluconeogenic gene expression. These data suggest that insulin-activated SREBP1c downregulates gluconeogenesis through CRY1-mediated FOXO1 degradation and that dysregulation of hepatic SREBP1c-CRY1 signalling may contribute to hyperglycaemia in diabetic animals.

The clock protein Cry regulates hepatic glucose metabolism. Here the authors show that SREBP1c, activated by insulin signalling after feeding, directly regulates Cry transcription at specific circadian time points, and that Cry represses hepatic glucose production by promoting proteasomal degradation of Foxo1.

Usefulness of high-sensitivity troponin I for the monitoring of subclinical acute cellular rejection after cardiac transplantation

BACKGROUND

There are conflicting data about the role of cardiac troponin I (cTnI) as determined by means of conventional methods for the prediction of acute rejection after heart transplantation (HT). The purpose of this study was to evaluate whether cTnI as measured by means of the early prototype high-sensitivity assay (hs-cTnI) can predict acute rejection episode after HT compared with grade of rejection in endomyocardial biopsy (EMB).

METHODS

This was a single-center cross-sectional study evaluating cTnI levels with the use of both hs-cTnI and current less sensitive conventional cTnI (conv-cTnI) assays measured at the time of EMB after HT. We calculated an index ratio of observed cTnI to expected mean cTnI for each individual patient defined as the mean cTnI measurements at EMB 60 days after HT.

RESULTS

A total of 252 biopsies from 47 patients were included in this study. In the multivariable mixed model analysis in relation to the presence of acute rejection 60 days after HT, hs-cTnI level was significantly related to the presence of rejection (P = .010). The hs-cTnI ratio index was significantly higher at the time of rejection (median, 1.37; interquartile range [IQR], 1.23-2.88) compared with those without rejection (median, 0.90; IQR, 0.51-1.16; P < .001). In receiver operating characteristic curve analysis, an hs-cTnI ratio index of ≥1.17 could predict the acute rejection with a sensitivity of 82.4% and a specificity of 77.1%.

CONCLUSIONS

An increased hs-cTnI ratio index was significantly related to rejection episodes. Serial monitoring of hs-cTnI and comparing it with the values without rejection might be useful for the detection of acute rejection after HT.

Mental Health Medication Use Correlates with Poor Outcome After Femoroacetabular Impingement Surgery in a Military Population

BACKGROUND

Femoroacetabular impingement is a common cause of hip pain in young adults. Several preoperative risk factors for poor outcomes with surgery have been identified; however, to our knowledge, no study has attempted to determine the effect of psychiatric comorbidity on outcomes with femoroacetabular impingement surgery.

METHODS

A retrospective review was performed on active-duty patients at one institution undergoing surgery for femoroacetabular impingement over five years. Medical records were reviewed for demographic characteristics, radiographic data, and history of mental health medication use. Return-to-duty status was considered the primary outcome measure. Outcome scores obtained included modified Harris hip scores, Single Assessment Numeric Evaluation scores, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, patient satisfaction, and Veterans RAND-12 scores. Patients taking mental health medication were compared with those who were not with regard to return to duty and validated patient-reported outcome measures.

RESULTS

Ninety-three patients (mean age, 32.2 years) were available for follow-up at a mean duration of 3.6 years. Of the seventeen patients discharged from service postoperatively, twelve (71%) were taking mental health medications. One-third (twenty-five) of seventy-six patients who returned to duty were taking mental health medication and this difference was significant (p < 0.006). Patients taking mental health medication had significantly poorer modified Harris hip scores (p < 0.02), WOMAC scores (p < 0.0008), and Veterans RAND-12 mental scores (p < 0.001). Antidepressant, antipsychotic, and multiple mental health medication use were all predictive of medical discharge due to hip pain.

CONCLUSIONS

Psychiatric comorbidities are an important risk factor in active-duty military personnel undergoing surgery for femoroacetabular impingement. Mental health medication use is associated with poorer outcome scores and can significantly lower the possibility of returning to active-duty status.

Anti-diabetic efficacy of KICG1338, a novel glycogen synthase kinase-3β inhibitor, and its molecular characterization in animal models of type 2 diabetes and insulin resistance

Selective inhibition of glycogen synthase kinase-3 (GSK3) has been targeted as a novel therapeutic strategy for diabetes mellitus. We investigated the anti-diabetic efficacy and molecular mechanisms of KICG1338 (2-(4-fluoro-phenyl)-3H-imidazo[4,5-b]pyridine-7-carboxylic acid(4-methyl-pyridin-3-yl)-amide), a GSK3β inhibitor, in three animal models: Otsuka Long-Evans Tokushima Fatty (OLETF) rats, leptin receptors-deficient db/db mice, and diet-induced obese (DIO) mice. Biochemical parameters including glucose tolerance tests and gene expressions associated with glucose metabolism were investigated. Glucose excursion decreased significantly by KICG1338-treated OLETF rats, accompanied by increase in insulin receptor substrate-1 and glucose transporter (GLUT)-4 expressions in muscle and decreased GLUT-2 expression in liver. Glucose-lowering effects were similarly observed in KICG1338-treated db/db and DIO mice. KICG1338 treatment increased adiponectin levels and decreased TNF-α levels. KICG1338 therapy also led to greater β-cell preservation and less hepatic fat infiltration with decreased expressions of genes involved in inflammation and endoplasmic reticulum stress. These data demonstrate anti-diabetic efficacy of KICG1338, a novel GSK3β inhibitor.

Gender differences in clinical and angiographic findings of patients with Takayasu arteritis

OBJECTIVES

Because Takayasu arteritis (TA) predominantly affects females, few data regarding gender differences have been reported. The aim of the present study is to describe clinical features and angiographic findings of patients with TA according to gender.

METHODS

According to the 1990 American College of Rheumatology criteria, 294 patients were diagnosed with TA between September 1994 and April 2014 at a single tertiary hospital. We reviewed clinical, laboratory, and radiologic data at the time of diagnosis.

RESULTS

Among the 294 patients studied, 257 (87.4%) were female (male:female ratio=1:6.9). Female patients had a higher tendency to exhibit blood pressure differences between arms (p=0.595) and a weak pulse at the brachial artery (p=0.063). In male patients, we observed higher serum creatinine levels (p=0.038) and hypertension more frequently (p=0.061) than in females. Females exhibited more common lesions in the thoracic aorta and its branches, while males had more frequent lesions in the abdominal aorta and its branches. An analysis of angiographic classification according to the International TA Conference in Tokyo 1994 classification revealed that male patients had a higher incidence of type IV and females showed a higher incidence of types I, IIa, and IIb.

CONCLUSIONS

Female patients with TA have more frequent involvement of the thoracic aorta and its branches, whereas involvement of the abdominal aorta and its branches is more common in males. Considering these gender-specific differences, adjustment of diagnostic criteria for TA according to gender may be necessary.

Ring finger protein20 regulates hepatic lipid metabolism through protein kinase A-dependent sterol regulatory element binding protein1c degradation

Sterol regulatory element binding protein1c (SREBP1c) is a key transcription factor for de novo lipogenesis during the postprandial state. During nutritional deprivation, hepatic SREBP1c is rapidly suppressed by fasting signals to prevent lipogenic pathways. However, the molecular mechanisms that control SREBP1c turnover in response to fasting status are not thoroughly understood. To elucidate which factors are involved in the inactivation of SREBP1c, we attempted to identify SREBP1c-interacting proteins by mass spectrometry analysis. Since we observed that ring finger protein20 (RNF20) ubiquitin ligase was identified as one of SREBP1c-interacting proteins, we hypothesized that fasting signaling would promote SREBP1c degradation in an RNF20-dependent manner. In this work, we demonstrate that RNF20 physically interacts with SREBP1c, leading to degradation of SREBP1c via ubiquitination. In accordance with these findings, RNF20 represses the transcriptional activity of SREBP1c and turns off the expression of lipogenic genes that are targets of SREBP1c. In contrast, knockdown of RNF20 stimulates the expression of SREBP1c and lipogenic genes and induces lipogenic activity in primary hepatocytes. Furthermore, activation of protein kinase A (PKA) with glucagon or forskolin enhances the expression of RNF20 and potentiates the ubiquitination of SREBP1c via RNF20. In wild-type and db/db mice, adenoviral overexpression of RNF20 markedly suppresses FASN promoter activity and reduces the level of hepatic triglycerides, accompanied by a decrease in the hepatic lipogenic program. Here, we reveal that RNF20-induced SREBP1c ubiquitination down-regulates hepatic lipogenic activity upon PKA activation.

CONCLUSION

RNF20 acts as a negative regulator of hepatic fatty acid metabolism through degradation of SREBP1c upon PKA activation. Knowledge regarding this process enhances our understanding of how SREBP1c is able to turn off hepatic lipid metabolism during nutritional deprivation.

Evaluation of Anti-SE Bacteriophage as Feed Additives to Prevent Salmonella enteritidis (SE) in Broiler

This experiment was conducted to evaluate anti-Salmonella enteritidis (anti-SE) bacteriophage as feed additives to prevent Salmonella enteritidis in broilers. The experimental diets were formulated for 2 phases feeding trial, and 3 different levels (0.05, 0.1 and 0.2%) of anti-SE bacteriophage were supplemented in basal diet. The basal diet was regarded as the control treatment. A total of 320 1-d-old male broilers (Ross 308) were allotted by randomized complete block (RCB) design in 8 replicates with 10 chicks per pen. All birds were raised on rice hull bedding in ambient controlled environment and free access to feed and water. There were no significant differences in body weight gain, feed intake and feed conversion ratio (FCR) at terminal period among treatments (p>0.05). Relative weights of liver, spleen, abdominal fat and tissue muscle of breast obtained from each anti-SE bacteriophage treatment were similar to control, with a slightly higher value in anti-SE bacteriophage 0.2%. In addition, a numerical difference of glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT) and LDL cholesterol level was observed in the 0.2% anti-SE bacteriophage application even though blood profiles were not significantly affected by supplemented levels of anti-SE bacteriophage (p>0.05). In the result of a 14 d record after Salmonella enteritidis challenge of 160 birds from 4 previous treatments, mortality was linearly decreased with increasing anti-SE bacteriophage level (p<0.05), and Salmonella enteritidis concentration in the cecum was decreased with increasing levels of anti-SE bacteriophage (p<0.05). Based on the results of this study, it is considered that supplementation of 0.2% anti-SE bacteriophage may not cause any negative effect on growth, meat production, and it reduces mortality after Salmonella enteritidis challenge. These results imply to a possible use of anti-SE bacteriophage as an alternative feed additive instead of antibiotics in broilers diet.

Technical note: Mice produced by intracytoplasmic sperm injection using a modified conventional method

A piezo-driven pipette that includes a small amount of mercury to enhance efficiency is widely used for mouse intracytoplasmic sperm injection (ICSI). Unfortunately, the use of toxic mercury is not permitted in hospital facilities and alternatives to mercury that enhance performance of the device do not work as well in the mouse. We have eliminated mercury toxicity and obtained acceptable ICSI efficiency using a modified conventional method. With this technique, oocyte survival, fertilization (number of 2-cell) and blastocyst rates were 77/126 (61.1%), 65/77 (84.4%), and 45/65 (69.2%), respectively. Eleven live pups were born from the transfer of thirty-two 2- to 4-cell embryos to 2 surrogate mothers. This conventional method is efficient, simple, and does not need the assistance of piezo-driven devices.

Diagnostic yield of fluoroscopy-guided biopsy for infectious spondylitis

BACKGROUND AND PURPOSE

CT is currently the method of choice for guiding biopsy of lesions of the spine. However, in our hospital, fluoroscopy-guided percutaneous biopsy has been preferred for several years because of equipment availability and easy craniocaudal angulation. The aim of this study was to evaluate the efficacy of fluoroscopy-guided percutaneous biopsy in a clinical setting for diagnosing infectious spondylitis.

MATERIALS AND METHODS

A retrospective study was performed to evaluate 170 fluoroscopy-guided percutaneous biopsies in 140 patients (male/female = 70:70; mean age, 65.1 years; range, 16-89 years) in a clinical setting who were suspected of having infectious spondylitis between July 2003 and March 2010. Diagnosis was based on pathologic confirmation by tissue or culture from biopsy. The percentage of adequate specimens for diagnosis, histopathologic diagnosis for infectious spondylitis, and positive cultures for causative organisms were evaluated by retrospective review of medical records.

RESULTS

Adequate specimens for diagnosis were obtained in 165 of 170 cases (97.1%). The diagnosis of infectious spondylitis resulted in 134 of 170 cases confirmed through histopathology or clinical outcome (78.8%). In 51 of 134 cases (38.1%), the causative organism was confirmed by specimens from percutaneous bone biopsy. There were no biopsy-related major complications. The most common organism isolated was Mycobacterium tuberculosis (24 cases), followed by Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus viridans.

CONCLUSIONS

Fluoroscopy-guided percutaneous biopsy is as accurate and effective as CT-guided biopsy for diagnosing infectious spondylitis.

G6PD up-regulation promotes pancreatic beta-cell dysfunction

Increased reactive oxygen species (ROS) induce pancreatic β-cell dysfunction during progressive type 2 diabetes. Glucose-6-phosphate dehydrogenase (G6PD) is a reduced nicotinamide adenine dinucleotide phosphate-producing enzyme that plays a key role in cellular reduction/oxidation regulation. We have investigated whether variations in G6PD contribute to β-cell dysfunction through regulation of ROS accumulation and β-cell gene expression. When the level of G6PD expression in pancreatic islets was examined in several diabetic animal models, such as db/db mice and OLEFT rats, G6PD expression was evidently up-regulated in pancreatic islets in diabetic animals. To investigate the effect of G6PD on β-cell dysfunction, we assessed the levels of cellular ROS, glucose-stimulated insulin secretion and β-cell apoptosis in G6PD-overexpressing pancreatic β-cells. In INS-1 cells, G6PD overexpression augmented ROS accumulation associated with increased expression of prooxidative enzymes, such as inducible nitric oxide synthase and reduced nicotinamide adenine dinucleotide phosphate oxidase. G6PD up-regulation also caused decrease in glucose-stimulated insulin secretion in INS-1 cells and primary pancreatic islets. Moreover, elevated G6PD expression led to β-cell apoptosis, concomitant with the increase in proapoptotic gene expression. On the contrary, suppression of G6PD with small interference RNA attenuated palmitate-induced β-cell apoptosis. Together, these data suggest that up-regulation of G6PD in pancreatic β-cells would induce β-cell dysregulation through ROS accumulation in the development of type 2 diabetes.

A newly identified CG301269 improves lipid and glucose metabolism without body weight gain through activation of peroxisome proliferator-activated receptor alpha and gamma

OBJECTIVE

Peroxisome proliferator-activated receptor (PPAR)-α/γ dual agonists have been developed to alleviate metabolic disorders. However, several PPARα/γ dual agonists are accompanied with unwanted side effects, including body weight gain, edema, and tissue failure. This study investigated the effects of a novel PPARα/γ dual agonist, CG301269, on metabolic disorders both in vitro and in vivo.

RESEARCH DESIGN AND METHODS

Function of CG301269 as a PPARα/γ dual agonist was assessed in vitro by luciferase reporter assay, mammalian one-hybrid assay, and analyses of PPAR target genes. In vitro profiles on fatty acid oxidation and inflammatory responses were acquired by fatty acid oxidation assay and quantitative (q)RT-PCR of proinflammatory genes. In vivo effect of CG301269 was examined in db/db mice. Total body weight and various tissue weights were measured, and hepatic lipid profiles were analyzed. Systemic glucose and insulin tolerance were measured, and the in vivo effect of CG301269 on metabolic genes and proinflammatory genes was examined by qRT-PCR.

RESULTS

CG301269 selectively stimulated the transcriptional activities of PPARα and PPARγ. CG301269 enhanced fatty acid oxidation in vitro and ameliorated insulin resistance and hyperlipidemia in vivo. In db/db mice, CG301269 reduced inflammatory responses and fatty liver, without body weight gain.

CONCLUSIONS

We demonstrate that CG301269 exhibits beneficial effects on glucose and lipid metabolism by simultaneous activation of both PPARα and PPARγ. Our data suggest that CG301269 would be a potential lead compound against obesity and related metabolic disorders.

Inhibitory effect of LXR activation on cell proliferation and cell cycle progression through lipogenic activity

Liver X receptor (LXR), a sterol-activated nuclear hormone receptor, has been implicated in cholesterol and fatty acid homeostasis via regulation of reverse cholesterol transport and de novo fatty acid synthesis. LXR is also involved in immune responses, including anti-inflammatory action and T cell proliferation. In this study, we demonstrated that activated LXR suppresses cell cycle progression and proliferation in certain cell types. Stimulation of LXR with synthetic ligand T0901317 or GW3965 inhibited cell growth rate and arrested the cell cycle at the G1/S boundary in several cells, such as RWPE1, THP1, SNU16, LNCaP, and HepG2. However, LXR ligands did not exhibit antiproliferative activity in PC3, HEK293, or HeLa cells. Interestingly, activated LXR-mediated cell cycle arrest is closely correlated with the lipogenic gene expression and triacylglyceride accumulation. In accordance with these findings, suppression of FAS via small-interference RNA (siRNA) partially alleviated the antiproliferative effect of LXR activation in RWPE1 cells. Together, these data suggest that LXR activation with its ligands inhibits cell proliferation and induces G1/S arrest through elevated lipogenic activity, thus proposing a novel effect of activated LXR on cell cycle regulation.

A nonthiazolidinedione peroxisome proliferator-activated receptor α/γ dual agonist CG301360 alleviates insulin resistance and lipid dysregulation in db/db mice

Activation of peroxisome proliferator-activated receptors (PPARs) have been implicated in the treatment of metabolic disorders with different mechanisms; PPARα agonists promote fatty acid oxidation and reduce hyperlipidemia, whereas PPARγ agonists regulate lipid redistribution from visceral fat to subcutaneous fat and enhance insulin sensitivity. To achieve combined benefits from activated PPARs on lipid metabolism and insulin sensitivity, a number of PPARα/γ dual agonists have been developed. However, several adverse effects such as weight gain and organ failure of PPARα/γ dual agonists have been reported. By use of virtual ligand screening, we identified and characterized a novel PPARα/γ dual agonist, (R)-1-(4-(2-(5-methyl-2-p-tolyloxazol-4-yl)ethoxy)benzyl)piperidine-2-carboxylic acid (CG301360), exhibiting the improvement in insulin sensitivity and lipid metabolism. CG301360 selectively stimulated transcriptional activities of PPARα and PPARγ and induced expression of their target genes in a PPARα- and PPARγ-dependent manner. In cultured cells, CG301360 enhanced fatty acid oxidation and glucose uptake and it reduced pro-inflammatory gene expression. In db/db mice, CG301360 also restored insulin sensitivity and lipid homeostasis. Collectively, these data suggest that CG301360 would be a novel PPARα/γ agonist, which might be a potential lead compound to develop against insulin resistance and hyperlipidemia.

Therapeutic trial of fluoroscopic interlaminar epidural steroid injection for axial low back pain: effectiveness and outcome predictors

BACKGROUND AND PURPOSE

An ESI for managing LBP is one of the most commonly performed interventions. The purpose of this observational study was to assess the effect of a therapeutic trial of a fluoroscopic interlaminar ESI for axial LBP and to analyze the outcome predictors.

MATERIALS AND METHODS

All patients who received an interlaminar ESI for axial LBP at our facility in 2007 and 2008 were included. Initial short-term follow-up was done at <1 month after ESI. ESI was considered effective if patients had a reduction of >50% in their pain scores. In July 2009, telephone interviews were conducted by using formatted questions including the NASS patient-satisfaction index. The symptom-free interval was computed by the Kaplan-Meier method. Outcome predictors such as age, sex, duration of LBP, and MR imaging findings were statistically analyzed by the Mann-Whitney U and the Fisher exact tests.

RESULTS

Eighty-one patients (male/female = 16:65; mean age, 49.9 years; range, 17-77 years) were included in the study. The interlaminar ESI was effective in 63 of the 81 patients (77.8%) at initial short-term follow-up. For the 63 patients in whom ESI was effective, the median symptom-free interval was 154 days (95% CI, 96-212 days). Among 68 patients for whom telephone interviews were possible, 44 patients (64.7%) replied positively to the NASS patient satisfaction index (NASS patient-satisfaction index, 1 or 2). There were no significant outcome predictors.

CONCLUSIONS

The therapeutic trial of a fluoroscopic interlaminar ESI was effective for axial LBP without significant outcome predictors.

Adiponectin represses colon cancer cell proliferation via AdipoR1- and -R2-mediated AMPK activation

In obesity, dysregulation of adipocytokines is involved in several pathological conditions including diabetes and certain cancers. As a member of the adipocytokines, adiponectin plays crucial roles in whole-body energy homeostasis. Recently, it has been reported that the level of plasma adiponectin is reduced in several types of cancer patients. However, it is largely unknown whether and how adiponectin affects colon cancer cell growth. Here, we show that adiponectin suppresses the proliferation of colon cancer cells including HCT116, HT29, and LoVo. In colon cancer cells, adiponectin attenuated cell cycle progression at the G(1)/S boundary and concurrently increased expression of cyclin-dependent kinase inhibitors such as p21 and p27. Adiponectin stimulated AMP-activated protein kinase (AMPK) phosphorylation whereas inhibition of AMPK activity blunted the effect of adiponectin on the proliferation of colon cancer cells. Furthermore, knockdown of adiponectin receptors such as AdipoR1 and AdipoR2 relieved the suppressive effect of adiponectin on the growth of colon cancer cells. In addition, adiponectin repressed the expression of sterol regulatory element binding protein-1c, which is a key lipogenic transcription factor associated with colon cancers. These results suggest that adiponectin could inhibit the growth of colon cancer cells through stimulating AMPK activity.

Liver X receptor ligands suppress ubiquitination and degradation of LXRalpha by displacing BARD1/BRCA1

Liver X receptor (LXR) is a ligand-activated transcription factor that plays important roles in cholesterol and lipid homeostasis. However, ligand-induced posttranslational modification of LXR is largely unknown. Here, we show that ligand-free LXRalpha is rapidly degraded by ubiquitination. Without ligand, LXRalpha interacts with an ubiquitin E3-ligase protein complex containing breast and ovarian cancer susceptibility 1 (BRCA1)-associated RING domain 1 (BARD1). Interestingly, LXR ligand represses ubiquitination and degradation of LXRalpha, and the interaction between LXRalpha and BARD1 is inhibited by LXR ligand. Consistently, T0901317, a synthetic LXR ligand, increased the level of LXRalpha protein in liver. Moreover, overexpression of BARD1/BRCA1 promoted the ubiquitination of LXRalpha and reduced the recruitment of LXRalpha to the target gene promoters, whereas BARD1 knockdown reversed such effects. Taken together, these data suggest that LXR ligand prevents LXRalpha from ubiquitination and degradation by detaching BARD1/BRCA1, which might be critical for the early step of transcriptional activation of ligand-stimulated LXRalpha through a stable binding of LXRalpha to the promoters of target genes.

Adiponectin increases fatty acid oxidation in skeletal muscle cells by sequential activation of AMP-activated protein kinase, p38 mitogen-activated protein kinase, and peroxisome proliferator-activated receptor alpha

Adiponectin has recently received a great deal of attention due to its beneficial effects on insulin resistance and metabolic disorders. One of the mechanisms through which adiponectin exerts such effects involves an increase in fatty acid oxidation in muscle and liver. In the present study, we demonstrate that 5'-AMP-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase (MAPK) are involved in the activation of peroxisome proliferator-activated receptor (PPAR)alpha by adiponectin in muscle cells. Adiponectin increases the transcriptional activity of PPARalpha and the expression of its target genes, including ACO, CPT1, and FABP3 in C2C12 myotubes. These effects were suppressed by the overexpression of a dominant-negative form of AMPK. Moreover, chemical inhibitors of AMPK and p38 MAPK potently repressed fatty acid oxidation and the induction of PPARalpha target gene expression by adiponectin. Interestingly, araA, an AMPK inhibitor, prevented the activation of p38 MAPK, whereas SB203580, a p38 MAPK inhibitor, did not affect AMPK activation, suggesting that p38 MAPK is a downstream signaling factor of AMPK. Taken together, these results suggest that adiponectin stimulates fatty acid oxidation in muscle cells by the sequential activation of AMPK, p38 MAPK, and PPARalpha.

Mass spectrometric identification of K210 essential for rat malonyl-CoA decarboxylase catalysis

Proteomic technology provides useful tools to detect protein modification sites in vivo and in vitro. In this work, we applied proteomics to identify an essential amino acid residue involved in Malonyl-CoA Decarboxylase (MCD) catalysis. A reaction with acetic anhydride and MCD, under mild conditions without acetyl CoA as a substrate, resulted in the acetylation of six lysyl residues, K210, K58, K167, K316, K388, and K444. When acetyl CoA was added to the reaction, K210 was protected from acetylation, indicating a potential role for this residue in catalysis. In addition, K210 was the only lysyl residue, out of six, that was not endogenously acetylated. Because K210, K308, and K388 are conserved across species, they were site-specifically mutated to methionine which is size-wise similar to lysine but not protonated. The K308M and K388M MCD mutants retained 60% of their enzyme activities, whereas the K210M mutant was completely inactive. These results strongly suggest that K210 is an essential residue in rat MCD catalysis and is a likely proton donor to the alpha carbon of malonyl-CoA. Therapeutic inhibition of MCD may be a viable approach to treating various clinical pathologies associated with defective fatty acid metabolism.

Placenta hominis protects osteoporosis in ovariectomized rats

In China, Japan, and Korea, placenta hominis extracts (PHEs) are used clinically for the treatment of osteoporosis. The anti-osteoporotic effect of PHEs was studied. The trabecular bone area and thickness in OVX rats decreased by 50% from those in sham-operated rats; these decreases were completely inhibited by administration of PHEs for 7 weeks. Osteoclast numbers and the osteoblast surface were enhanced in OVX rats, but PHEs had no effect on these phenomena. Serum phosphorus and alkaline phosphatase in OVX rats increased compared to those in sham-operated rats, but the increases were not affected by the administration of PHEs. Thyroxine (T4) level was stimulated in OVX rats. The extracts inhibited the T4 level in the OVX rats. These results strongly suggest that PHEs be effective in preventing the development of bone loss induced by OVX in rats.

Carbon monoxide and nitric oxide protect against tumor necrosis factor-alpha-induced apoptosis in osteoblasts: HO-1 is necessary to mediate the protection

BACKGROUND

Carbon monoxide (CO) and nitric oxide (NO) each have unique roles for various inflammatory states, including inflammatory bone resorption. Although it is known that NO can induce the expression of the cytoprotective enzyme HO-1, there is no information as to whether the protective effect of CO requires NO production or whether CO must induce the expression of HO-1 to exert its functional effects.

METHODS

Murine osteoblast cells, MC3T3E1 osteoblasts, were cultured for CO and NO-associated HO-1 experiments and were transfected with pcDNA 3, pcDNA 3-HO-1, control siRNA or HO-1 siRNA using Nucleofector. For cell death measurement, MTT and annexin V assays were used. We performed Western blotting to check the expressions of HO-1 and iNOs and measured the HO-1 enzyme activity. We also measured the amounts of nitrite and nitrate using Griess reagents.

RESULTS

The increased expression of HO-1 is required for the protective effect of NO and a single treatment of CO can increase the expression of HO-1, and this is also important for the protective effect of CO in MC3T3E1 osteoblasts. CO as well as NO attenuates the TNF-alpha-induced apoptosis in osteoblasts. The anti-apoptotic effect of CO or NO is not mediated by cGMP, and CO has no effect on the release of NO. The inhibition of HO-1 with using the HO-1 inhibitor ZnPP or HO-1 siRNA resulted in a striking increase of apoptosis in the CO/TNF-alpha-treated cells. Furthermore, HO-1 overexpression showed resistance against the TNF-alpha-induced cytotoxicity in the MC3T3E1 osteoblasts.

CONCLUSIONS

There is a need for HO-1 expression to mediate the protection provided by exogenous CO or NO in osteoblasts.

Yuk-Hap-Tang induces apoptosis by intervening mn-SOD in human cervical carcinoma HeLa cells

Yuk-Hap-Tang (YHT) induces cell death in human cervical carcinoma HeLa cells. Caspase-3, -6 and -9 were markedly activated in HeLa cells treated with YHT. The preferred substrate for caspase-3 cysteine protease, PARP, was cleaved to its 85-kDa cleavage product. YHT increased the amount of the anti-apoptotic protein, Bcl-2, and the pro-apoptotic protein, Bax. Although p53 has been reported to accumulate in cancer cells in response to anticancer agents, the p53 expression level was not changed in HeLa cells treated with YHT. Manganese (Mn)-TBAP, a mitochondria-specific SOD mimetic agent and NAC/GSH (N-acetyl cysteine/ reduced glutathione) reduced the YHT-induced cytotoxicity and decreased the number of the YHT-induced apoptotic cells. Furthermore, YHT reduced the expression of Mn-SOD protein and its activity in HeLa cells. The data demonstrate that YHT induces the apoptosis of human cervical carcinoma HeLa cells by intervening Mn-SOD.

Membrane fusion correlates with surface charge in exocytic vesicles

Stimulation of gastric parietal cells results in exocytic recruitment of the proton pump (H(+),K(+)-ATPase) from a pool of intracellular membranes (tubulovesicles) to the apical plasma membrane. We have previously reconstituted a step in this process, the homotypic fusion of tubulovesicles, and shown that they also fuse with liposomes in a protein-dependent manner [Duman, J. G., Singh, G., Lee, G. Y., Machen, T. E., and Forte, J. G. (2002) Traffic 3, 203-17]. Further, the lipid composition of the liposomes affects their ability to undergo fusion with tubulovesicles. In the present study, we investigated the lipid requirements for tubulovesicular membrane fusion using a fluorescent probe relaxation assay as well as transfer of protein between tubulovesicles and liposomes of defined composition. Initially, we tested the ability of tubulovesicles to undergo fusion with a panel of synthetic phosphatidylcholine-based liposomes containing a variety of common membrane lipids of various shapes and charges. We found that anionic lipids such as phosphatidylserine, phosphatidic acid, and phosphoinositides were best able to enhance tubulovesicle-liposome fusion and that they did it in a dose-dependent, apparently saturable manner. Next, we altered the lipid compositions of actual tubulovesicles and observed that addition of anionic lipids was able to enhance tubulovesicle-tubulovesicle fusion in vitro; thus, we hypothesized that the charge imparted by the lipids, per se, was responsible for the enhancement of membrane fusion. Accordingly, addition of negative charges to one of two pools of tubulovesicles in a fusion assay using anionic detergents increased membrane fusion; whereas, addition of positively charged cationic detergent decreased membrane fusion and could be used to back-titrate the anionic effects. Surprisingly, when both pools of fusing membranes were loaded with anionic detergents, fusion was markedly increased. The ability of anionic charges to enhance fusion was diminished as the ionic strength of the fusion medium was increased, suggesting that the mechanism of fusion enhancement depends on the surface charge of the membranes. Finally, the fusion reaction was highly dependent on temperature, and anionic charge appears to lower the activation energy of the fusion reaction. Taken together, these data suggest that (1) tubulovesicular fusion is enhanced by an increase in membrane surface negative charge associated with a lower activation energy and (2) neutralization or reversal of the surface charge prevents tubulovesicular fusion.

Peroxisomal-proliferator-activated receptor alpha activates transcription of the rat hepatic malonyl-CoA decarboxylase gene: a key regulation of malonyl-CoA level

MCD (malonyl-CoA decarboxylase), which catalyses decarboxylation of malonyl-CoA, is known to play an important role in the regulation of malonyl-CoA concentration. Recently, it has been observed that the expression of MCD is significantly decreased in the hearts of the PPARalpha (peroxisome-proliferator-activated receptor alpha) (-/-) mice, where the rate of fatty-acid oxidation is decreased by the increased malonyl-CoA level [Campbell, Kozak, Wagner, Altarejos, Dyck, Belke, Severson, Kelly and Lopaschuk (2002) J. Biol. Chem. 277, 4098-4103]. This suggests that MCD may be transcriptionally regulated by PPARalpha. To investigate whether PPARalpha is truly responsible for transcriptional regulation of the rat MCD gene, transient reporter assay was performed in CV-1 cells. The promoter activity was increased by 17-fold in CV-1 cells co-transfected with PPARalpha/retinoid X receptor alpha expression plasmid. In sequence analysis of the promoter region, three putative PPREs (PPAR response elements) were identified, and promoter deletion analysis showed that PPRE2 and PPRE3 were functional. Electrophoretic mobility-shift assays revealed that PPARalpha/retinoid X receptor alpha heterodimer indeed bound to the two PPREs, and the binding specificity of PPARalpha on PPRE was also confirmed by experiments with mutated oligonucleotides. These results indicate that the elements behaved as a responsive site to PPARalpha activation. MCD mRNA levels in WY14643-treated rat hepatoma cells as well as in the liver of fenofibrate-fed Otsuka Long-Evans Tokushima fatty rats were also found to be increased, suggesting that PPARalpha can activate the rat hepatic MCD transcription by binding to the PPREs in the promoter. We propose that MCD performs an important role in understanding the regulatory mechanism between activated PPARalpha and fatty-acid oxidation by altering the malonyl-CoA concentration.

Metalloprotease-specific poly(ethylene glycol) methyl ether-peptide-doxorubicin conjugate for targeting anticancer drug delivery based on angiogenesis

This article proposes a novel cancer-targeting drug-delivery system based on angiogenesis, in which the enzymatic activity of type IV collagenases is used to cleave the inactive drug conjugate, thereby activating drug fragments. In this study, the amount and distribution of metalloprotease (MMP)-2 and MMP-9 secreted from Lewis lung carcinoma (LCC) cells and the formation of blood vessels were evaluated by gelatin zymography, in situ film zymography and immunostaining. LLC cells secreted MMP-2 and MMP-9, thereby distributing large amounts of MMPs around a solid tumor. The newly developed blood vessels were also found in a solid LLC tumor. The anticancer drug conjugate (mPEG-GPLGV-DOX) was synthesized by conjugating doxorubicin with Gly-Pro-Leu-Gly-Val (GPLGV) peptide and poly(ethylene glycol) methyl ether (mPEG). GPLGV pentapeptide was used as a substrate for MMP-2 and MMP-9, where the cleavage of Gly-Val bond by MMP was expected. In addition, mPEG was grafted to peptide-doxorubicin conjugate to increase the circulation time in the body and to reduce the cytotoxicity of the anticancer drug. The mPEG-GPLGV-DOX conjugate formed a micelle structure in aqueous solution, with a critical micelle concentration (CMC) of about 0.25 mg/ml and a diameter of 73.1 +/- 12.7 nm at 1 mg/ml. In an in vivo experiment, mPEG-GPLGV-DOX showed 20% chemotherapeutic activity compared with free doxorubicin. Although a 50 mg/kg dose of mPEG-GPLGV-DOX showed similar therapeutic effects to a 10 mg/kg dose of doxorubicin, the life span of mice in the conjugate group was significantly increased. Therefore, an efficient anticancer drug-delivery system could be created by increasing therapeutic efficiency and decreasing drug-toxicity by optimizing the degradation rate of the peptide link by MMP and circulation time in the body.

Radiosurgery for vestibular schwannomas: preliminary results of the Adelaide experience

We present the preliminary results of our experience with Linear Accelerator (LINAC) radiosurgery for unilateral vestibular schwannomas. The treatment outcomes of 42 patients with a minimum follow-up of 12 months are reported. An excellent rate of tumour control was achieved with a relatively low complication rate. The current results compare favourably with other reported studies in the literature.

Genomic organization and characterization of the promoter of rat malonyl-CoA decarboxylase gene

Malonyl-CoA decarboxylase (MCD) catalyzes the decarboxylation of malonyl-CoA, an elongating agent for fatty acid synthesis and also known as a fuel-sensing mediator. In order to elucidate the genome organization, we isolated a 2020 bp rat MCD cDNA from rat brain cDNA library and isolated the corresponding rat genomic clones from the rat genomic PAC library. Sequencing and comparison of these clones showed that the MCD genome consists of five exons and four introns spanning approximately 17 kb. The proximal upstream region is GC-rich, lacks a TATA box, and contains a variety of putative transcriptional regulatory elements within 2 kb. A major transcriptional initiation site was identified by a primer extension at a site 157 nucleotides upstream of the translational initiation site. To investigate the transcriptional regulation of MCD, a series of 5'-deletion constructs of the 5'-flanking region were generated and cloned upstream from the luciferase reporter gene. By comparing promoter activity in CV-1 cells, we suggest that an area of -15 bp 5' from the first exon acted as a basal promoter for MCD and that there are positive cis-regulatory elements in the region from -55 to -325 bp and negative regulator elements in the region -1380 to -2240 bp.

Rat Malonyl-CoA Decarboxylase; Cloning, Expression in E. coli and its Biochemical Characterization

Malonyl-CoA decarboxylase (E.C.4.1.1.9) catalyzes the conversion of malonyl-CoA to acetyl-CoA. Although the metabolic role of this enzyme has not been fully defined, it has been reported that its deficiency is associated with mild mental retardation, seizures, hypotonia, cadiomyopathy, developmental delay, vomiting, hypoglycemia, metabolic acidosis, and malonic aciduria. Here, we isolated a cDNA clone for malonyl CoA decarboxylase from a rat brain cDNA library, expressed it in E. coli, and characterized its biochemical properties. The full-length cDNA contained a single open-reading frame that encoded 491 amino acid residues with a calculated molecular weight of 54, 762 Da. Its deduced amino acid sequence revealed a 65.6% identity to that from the goose uropigial gland. The sequence of the first 38 amino acids represents a putative mitochondrial targeting sequence, and the last 3 amino acid sequences (SKL) represent peroxisomal targeting ones. The expression of malonyl CoA decarboxylase was observed over a wide range of tissues as a single transcript of 2.0 kb in size. The recombinant protein that was expressed in E. coli was used to characterize the biochemical properties, which showed a typical Michaelis-Menten substrate saturation pattern. The Km and Vmax were calculated to be 68 microM and 42.6 micromol/min/mg, respectively.

Spinocerebellar ataxia type 6 and episodic ataxia type 2 in a Korean family

Spinocerebellar ataxia type 6 (SCA6), episodic ataxia type 2 (EA2) and familial hemiplegic migraine (FHM) have been known as allelic disorders, which are caused by the alteration of the alpha1A voltage-dependent calcium channel subunit. Expansions of the CAG repeat in the CACNA1A gene on the short arm of the chromosome 19 induce SCA6, and point mutations in the same gene are responsible for EA2 and FHM. In recent studies, both SCA6 and EA2 have been concurrently found in families with 26 CAG repeats without previously reported point mutations either in coding sequences or in intron-exon junctions. We describe a Korean family with CAG26 repeats in the CACNA1A gene. Some of the affected family members had progressive ataxia typical of SCA6 whereas others had episodic vertigo responsive to acetazolamide typical of EA2. Our family support that SCA6 and EA2 are allelic disorders with a high phenotypic variability.