Plasma concentrations of a novel, adipose-specific protein, adiponectin, in type 2 diabetic patients

Adiponectin is a novel, adipose-specific protein abundantly present in the circulation, and it has antiatherogenic properties. We analyzed the plasma adiponectin concentrations in age- and body mass index (BMI)-matched nondiabetic and type 2 diabetic subjects with and without coronary artery disease (CAD). Plasma levels of adiponectin in the diabetic subjects without CAD were lower than those in nondiabetic subjects (6.6+/-0.4 versus 7.9+/-0.5 microg/mL in men, 7.6+/-0.7 versus 11.7+/-1.0 microg/mL in women; P<0.001). The plasma adiponectin concentrations of diabetic patients with CAD were lower than those of diabetic patients without CAD (4.0+/-0.4 versus 6.6+/-0.4 microg/mL, P<0.001 in men; 6.3+/-0.8 versus 7.6+/-0. 7 microg/mL in women). In contrast, plasma levels of leptin did not differ between diabetic patients with and without CAD. The presence of microangiopathy did not affect the plasma adiponectin levels in diabetic patients. Significant, univariate, inverse correlations were observed between adiponectin levels and fasting plasma insulin (r=-0.18, P<0.01) and glucose (r=-0.26, P<0.001) levels. In multivariate analysis, plasma insulin did not independently affect the plasma adiponectin levels. BMI, serum triglyceride concentration, and the presence of diabetes or CAD remained significantly related to plasma adiponectin concentrations. Weight reduction significantly elevated plasma adiponectin levels in the diabetic subjects as well as the nondiabetic subjects. These results suggest that the decreased plasma adiponectin concentrations in diabetes may be an indicator of macroangiopathy.

Novel modulator for endothelial adhesion molecules: adipocyte-derived plasma protein adiponectin

BACKGROUND

Among the many adipocyte-derived endocrine factors, we recently found an adipocyte-specific secretory protein, adiponectin, which was decreased in obesity. Although obesity is associated with increased cardiovascular mortality and morbidity, the molecular basis for the link between obesity and vascular disease has not been fully clarified. The present study investigated whether adiponectin could modulate endothelial function and relate to coronary disease.

METHODS AND RESULTS

For the in vitro study, human aortic endothelial cells (HAECs) were preincubated for 18 hours with the indicated amount of adiponectin, then exposed to tumor necrosis factor-alpha (TNF-alpha) (10 U/mL) or vehicle for the times indicated. The adhesion of human monocytic cell line THP-1 cells to HAECs was determined by adhesion assay. The surface expression of vascular cell adhesion molecule-1 (VCAM-1), endothelial-leukocyte adhesion molecule-1 (E-selectin), and intracellular adhesion molecule-1 (ICAM-1) was measured by cell ELISA. Physiological concentrations of adiponectin dose-dependently inhibited TNF-alpha-induced THP-1 adhesion and expression of VCAM-1, E-selectin, and ICAM-1 on HAECs. For the in vivo study, the concentrations of adiponectin in human plasma were determined by a sandwich ELISA system that we recently developed. Plasma adiponectin concentrations were significantly lower in patients with coronary artery disease than those in age- and body mass index-adjusted control subjects.

CONCLUSIONS

These observations suggest that adiponectin modulates endothelial inflammatory response and that the measurement of plasma adiponectin levels may be helpful in assessment of CAD risk.

Adiponectin, an adipocyte-derived plasma protein, inhibits endothelial NF-kappaB signaling through a cAMP-dependent pathway

BACKGROUND

Among the many adipocyte-derived endocrine factors, we found an adipocyte-derived plasma protein, adiponectin, that was decreased in obesity. We recently demonstrated that adiponectin inhibited tumor necrosis factor-alpha (TNF-alpha)-induced expression of endothelial adhesion molecules and that plasma adiponectin level was reduced in patients with coronary artery disease (CIRCULATION: 1999;100:2473-2476). However, the intracellular signal by which adiponectin suppressed adhesion molecule expression was not elucidated. The present study investigated the mechanism of modulation for endothelial function by adiponectin.

METHODS AND RESULTS

The interaction between adiponectin and human aortic endothelial cells (HAECs) was estimated by cell ELISA using biotinylated adiponectin. HAECs were preincubated for 18 hours with 50 microg/mL of adiponectin, then exposed to TNF-alpha (10 U/mL) or vehicle for the times indicated. NF-kappaB-DNA binding activity was determined by electrophoretic mobility shift assays. TNF-alpha-inducible phosphorylation signals were detected by immunoblotting. Adiponectin specifically bound to HAECs in a saturable manner and inhibited TNF-alpha-induced mRNA expression of monocyte adhesion molecules without affecting the interaction between TNF-alpha and its receptors. Adiponectin suppressed TNF-alpha-induced IkappaB-alpha phosphorylation and subsequent NF-kappaB activation without affecting other TNF-alpha-mediated phosphorylation signals, including Jun N-terminal kinase, p38 kinase, and Akt kinase. This inhibitory effect of adiponectin is accompanied by cAMP accumulation and is blocked by either adenylate cyclase inhibitor or protein kinase A (PKA) inhibitor.

CONCLUSIONS

These observations raise the possibility that adiponectin, which is naturally present in the blood stream, modulates the inflammatory response of endothelial cells through cross talk between cAMP-PKA and NF-kappaB signaling pathways.

Efficient in vivo manipulation of mouse genomic sequences at the zygote stage

We describe a transgenic mouse line carrying the cre transgene under the control of the adenovirus EIIa promoter that targets expression of the Cre recombinase to the early mouse embryo. To assess the ability of this recombinase to excise loxP-flanked DNA sequences at early stages of development, we bred EIIa-cre transgenic mice to two different mouse lines carrying loxP-flanked target sequences: (i) a strain with a single gene-targeted neomycin resistance gene flanked by 1oxP sites and (ii) a transgenic line carrying multiple transgene copies with internal loxP sites. Mating either of these loxP-carrying mouse lines to EIIa-cre mice resulted in first generation progeny in which the loxP-flanked sequences had been efficiently deleted from all tissues tested, including the germ cells. Interbreeding of these first generation progeny resulted in efficient germ-line transmission of the deletion to subsequent generations. These results demonstrate a method by which loxP-flanked DNA sequences can be efficiently deleted in the early mouse embryo. Potential applications of this approach are discussed, including reduction of multicopy transgene loci to produce single-copy transgenic lines and introduction of a variety of subtle mutations into the line.

Adipocyte-derived plasma protein, adiponectin, suppresses lipid accumulation and class A scavenger receptor expression in human monocyte-derived macrophages

BACKGROUND

Excessive lipid accumulation in macrophages plays an important role in the development of atherosclerosis. Recently, we discovered an adipocyte-specific plasma protein, adiponectin, that is decreased in patients with coronary artery disease. We previously demonstrated that adiponectin acts as a modulator for proinflammatory stimuli and inhibits monocyte adhesion to endothelial cells. The present study investigated the effects of adiponectin on lipid accumulation in human monocyte-derived macrophages.

METHODS AND RESULTS

Human monocytes were differentiated into macrophages by incubation in human type AB serum for 7 days, and the effects of adiponectin were investigated at different time intervals. Treatment with physiological concentrations of adiponectin reduced intracellular cholesteryl ester content, as determined using the enzymatic, fluorometric method. The adiponectin-treated macrophages contained fewer lipid droplets stained by oil red O. Adiponectin suppressed the expression of the class A macrophage scavenger receptor (MSR) at both mRNA and protein levels by Northern and immunoblot analyses, respectively, without affecting the expression of CD36, which was quantified by flow cytometry. Adiponectin reduced the class A MSR promoter activity, as measured by luciferase reporter assay. Adiponectin treatment dose-dependently decreased class A MSR ligand binding and uptake activities. The mRNA level of lipoprotein lipase as a marker of macrophage differentiation was decreased by adiponectin treatment, but that of apolipoprotein E was not altered. Adiponectin was detected around macrophages in the human injured aorta by immunohistochemistry.

CONCLUSIONS

The adipocyte-derived plasma protein adiponectin suppressed macrophage-to-foam cell transformation, suggesting that adiponectin may act as a modulator for macrophage-to-foam cell transformation.

Generalized-ensemble algorithms for molecular simulations of biopolymers

In complex systems with many degrees of freedom such as peptides and proteins, there exists a huge number of local-minimum-energy states. Conventional simulations in the canonical ensemble are of little use, because they tend to get trapped in states of these energy local minima. A simulation in generalized ensemble performs a random walk in potential energy space and can overcome this difficulty. From only one simulation run, one can obtain canonical-ensemble averages of physical quantities as functions of temperature by the single-histogram and/or multiple-histogram reweighting techniques. In this article we review uses of the generalized-ensemble algorithms in biomolecular systems. Three well-known methods, namely, multicanonical algorithm, simulated tempering, and replica-exchange method, are described first. Both Monte Carlo and molecular dynamics versions of the algorithms are given. We then present three new generalized-ensemble algorithms that combine the merits of the above methods. The effectiveness of the methods for molecular simulations in the protein folding problem is tested with short peptide systems.

An adipocyte-derived plasma protein, adiponectin, adheres to injured vascular walls

Adipose tissue secretes a variety of proteins into the bloodstream. We have previously reported a novel cDNA, apM1 (adipose most abundant gene transcript 1), which is specifically and abundantly expressed in adipose tissue [1]. Primary structure analysis predicted that the apM1 gene product possesses significant homology to collagens VIII, X and complement factor C1q, and we named it adiponectin. In the current study, we analyzed characteristics of adiponectin in vitro and in vivo. Adiponectin protein was proved to be secreted into the medium when the cDNA was transfected to COS cells. Anti-adiponectin cross-reactivities were abundantly detected in the human plasma. In solid-phase binding assays, adiponectin specifically bound to collagen types I, III and V, which are present in vascular intima. Immunohistochemical analysis revealed that adiponectin was detected in the walls of the catheter-injured vessels but not in the intact vascular walls. These data suggest that adiponectin is a plasma protein produced by adipose tissue and accumulates in vascular walls when the endothelial barrier is injured.

Allergic Rhinitis and its Impact on Asthma (ARIA): achievements in 10 years and future needs

Allergic rhinitis (AR) and asthma represent global health problems for all age groups. Asthma and rhinitis frequently coexist in the same subjects. Allergic Rhinitis and its Impact on Asthma (ARIA) was initiated during a World Health Organization workshop in 1999 (published in 2001). ARIA has reclassified AR as mild/moderate-severe and intermittent/persistent. This classification closely reflects patients' needs and underlines the close relationship between rhinitis and asthma. Patients, clinicians, and other health care professionals are confronted with various treatment choices for the management of AR. This contributes to considerable variation in clinical practice, and worldwide, patients, clinicians, and other health care professionals are faced with uncertainty about the relative merits and downsides of the various treatment options. In its 2010 Revision, ARIA developed clinical practice guidelines for the management of AR and asthma comorbidities based on the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) system. ARIA is disseminated and implemented in more than 50 countries of the world. Ten years after the publication of the ARIA World Health Organization workshop report, it is important to make a summary of its achievements and identify the still unmet clinical, research, and implementation needs to strengthen the 2011 European Union Priority on allergy and asthma in children.

Chronic lithium treatment increases the expression of brain-derived neurotrophic factor in the rat brain

RATIONALE

Lithium is the most widely prescribed mood stabilizer, but the precise mechanism of lithium is unresolved.

OBJECTIVE

We examine the effects of the administration of therapeutically relevant concentrations of lithium on the expression of brain-derived neurotrophic factor (BDNF) and its receptor, Trk B, as well as glia-derived neurotrophic factor (GDNF) and its receptors, RET and GDNFR-alpha, in the rat brain. In addition, we also examined the effect of another well-prescribed mood stabilizer, valproate, on the expression of BDNF and GDNF.

METHODS

Rats were kept on a 0.2% lithium carbonate-containing diet for 1, 7, 14, or 28 days or treated with valproate (400 mg/kg per day i.p.) for 1 or 14 days. After the brains were rapidly removed, the levels of BDNF, GDNF, and their receptors were measured by ELISA or western blot analysis.

RESULTS

Chronic lithium treatment for 14 and 28 days significantly increased the expression of BDNF in the hippocampus and temporal cortex. In addition, chronic lithium treatment for 14 days significantly increased the expression of BDNF in the frontal cortex. In contrast, acute or chronic dietary lithium treatment did not alter GDNF expression in these brain regions. In addition, acute or chronic lithium treatments did not change the levels of Trk B, RET, or GDNFR-alpha immunoreactivity. As well as lithium, repeated administration of valproate also increased the expression of BDNF in the frontal cortex and hippocampus.

CONCLUSIONS

Our results suggest that the chronic administration of mood stabilizers may produce a neurotrophic effect mediated by the upregulation of BDNF in the rat brain.

Effects of chitin and its derivatives on the proliferation and cytokine production of fibroblasts in vitro

The effects of chitin and its derivatives on the proliferation of fibroblasts and on the production of cytokines were examined in vitro. Chitin and its derivatives showed almost no acceleratory effect on the proliferation of cultured fibroblasts. On the contrary, high-concentration 500 micrograms ml-1) D-glucosamine cultures supplemented with or without a 10% fetal calf serum (FCS) supplementation showed a significant (P < 0.05) reduction in the rate of proliferation of L929 fibroblast cells relative to control. High-concentration chitosan cultures supplemented with 10% FCS showed a significant (P < 0.05) reduction in the rate of L929 fibroblast proliferation. However, the inhibition of cell proliferation by high concentrations of chitosan did not show in cultures without FCS. Interleukin-8 (IL-8) was induced in the supernatants of rat primary cultured dermal fibroblasts stimulated with chitin and its derivatives. Chitin and its derivatives did not stimulate the production of IL-6 by mouse dermal primary cultured fibroblasts. IL-1 alpha, IL-1 beta and tumour necrosis factor-alpha were not detected in the fibroblast supernatants. These observations support the notion that cell proliferation is accelerated indirectly by chitin and its derivatives when these materials are used in vivo. In vivo findings of a angiogenesis and migration of neutrophils may be due to persistent release of IL-8 from fibroblasts.

Oxidative stress by tumor-derived macrophages suppresses the expression of CD3 zeta chain of T-cell receptor complex and antigen-specific T-cell responses

One of the important mechanisms of immunosuppression in the tumor-bearing status has been attributed to the down-modulation of the CD3 zeta chain and its associated signaling molecules in T cells. Thus, the mechanism of the disappearance of CD3 zeta was investigated in tumor-bearing mice (TBM). The decrease of CD3 zeta was observed both in the cell lysate and intact cells. Direct interaction of T cells with macrophages from TBM (TBM-macrophages) induced the decrease of CD3 zeta, and depletion of macrophages rapidly restored the CD3 zeta expression. We found that treatment of such macrophages with N-acetylcysteine, known as antioxidant compound, prevented the decrease of CD3 zeta. Consistent with this result, the addition of oxidative reagents such as hydrogen peroxide and diamide induced the decrease of CD3 zeta expression in T cells. Consequently, the loss of CD3 zeta resulted in suppression of the antigen-specific T-cell response. These results demonstrate that oxidative stress by macrophages in tumor-bearing status induces abnormality of the T-cell receptor complex by cell interactions with T cells. Therefore, our findings suggest that oxidative stress contributes to the regulation of the expression and function of the T-cell receptor complex.

New Monte Carlo algorithms for protein folding

Over the past three decades, a number of powerful simulation algorithms have been introduced to the protein folding problem. For many years, the emphasis has been placed on how to both overcome the multiple minima problem and find the conformation with the global minimum potential energy. Since the new view of the protein folding mechanism (based on the free energy landscape of the protein system) arose in the past few years, however, it is now of interest to obtain a global knowledge of the phase space, including the intermediate and denatured states of proteins. Monte Carlo methods have proved especially valuable for these purposes. As well as new, powerful optimization techniques, novel algorithms that can sample much a wider phase space than conventional methods have been established.

A phase II trial of gefitinib as first-line therapy for advanced non-small cell lung cancer with epidermal growth factor receptor mutations

Retrospective analysis has shown that activating mutations in exons 18-21 of the epidermal growth factor receptor (EGFR) gene are a predictor of response to gefitinib. We conducted a phase II trial to evaluate the efficacy and safety of gefitinib as first-line therapy for advanced non-small cell lung cancer (NSCLC) with EGFR mutations. Patients with stage IIIB or IV chemotherapy-naïve NSCLC with EGFR mutation were treated with 250 mg gefitinib daily. For mutational analysis, DNA was extracted from paraffin-embedded tissues and EGFR mutations were analysed by direct sequence of PCR products. Twenty (24%) of the 82 patients analysed had EGFR mutations (deletions in or near E746-A750, n=16; L858R, n=4). Sixteen patients were enrolled and treated with gefitinib. Twelve patients had objective response and response rate was 75% (95% CI, 48-93%). After a median follow-up of 12.7 months (range, 3.1-16.8 months), 10 patients demonstrated disease progression, with median progression-free survival of 8.9 months (95% CI, 6.7-11.1 months). The median overall survival time has not yet been reached. Most of the toxicities were mild. This study showed that gefitinib is very active and well tolerated as first-line therapy for advanced NSCLC with EGFR mutations.

Production of adiponectin, an anti-inflammatory protein, in mesenteric adipose tissue in Crohn's disease

BACKGROUND AND AIMS

A characteristic feature of Crohn's disease (CD) is mesenteric adipose tissue hypertrophy. Mesenteric adipocytes or specific proteins secreted by them may play a role in the pathogenesis of CD. We recently identified adiponectin as an adipocyte specific protein with anti-inflammatory properties. Here we report on expression of adiponectin in mesenteric adipose tissue of CD patients.

METHODS AND RESULTS

Mesenteric adipose tissue specimens were obtained from patients with CD (n = 22), ulcerative colitis (UC) (n = 8) and, for controls, colon carcinoma patients (n = 28) who underwent intestinal resection. Adiponectin concentrations were determined by enzyme linked immunosorbent assay, and adiponectin mRNA levels were determined by real time quantitative reverse transcription-polymerase chain reaction. Tissue concentrations and release of adiponectin were significantly increased in hypertrophied mesenteric adipose tissue of CD patients compared with normal mesenteric adipose tissue of CD patients (p = 0.002, p = 0.040, respectively), UC patients (p = 0.002, p = 0.003), and controls (p<0.0001, p<0.0001). Adiponectin mRNA levels were significantly higher in hypertrophied mesenteric adipose tissue of CD patients than in paired normal mesenteric adipose tissue from the same subjects (p = 0.024). Adiponectin concentrations in hypertrophied mesenteric adipose tissue of CD patients with an internal fistula were significantly lower than those of CD patients without an internal fistula (p = 0.003).

CONCLUSIONS

Our results suggest that adipocytes in hypertrophied mesenteric adipose tissue produce and secrete significant amounts of adiponectin, which could be involved in the regulation of intestinal inflammation associated with CD.

Demonstration of diastolic and presystolic Purkinje potentials as critical potentials in a macroreentry circuit of verapamil-sensitive idiopathic left ventricular tachycardia

OBJECTIVES

The purpose of this study was to determine the relation of diastolic and presystolic potentials recorded during verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) to reentry circuit.

BACKGROUND

Successful ablation of verapamil-sensitive ILVT at the zone of slow conduction from which the diastolic potential is recorded has been reported. However, the relationship between the diastolic potential and the reentrant circuit remains a matter of debate.

METHODS

Radiofrequency (RF) ablation was performed in 20 patients with verapamil-sensitive ILVT. After identifying the ventricular tachycardia (VT) exit site, we searched for the mid-diastolic potential (P1) during VT. Entrainment followed by RF current application was performed. If the mid-diastolic potential could not be detected, RF current was applied at the VT exit site showing the earliest ventricular activation with a single fused presystolic Purkinje potential (P2).

RESULTS

In 15 of 20 patients, both P1 and P2 were recorded during VT from midseptal region. Entrainment pacing captured P1 orthodromically and reset the VT. The interval from stimulus to P1 was prolonged as the pacing rate was increased. Radiofrequency ablation was successfully performed at this site in all 15 patients. After successful ablation, P1 appeared after the QRS complex during sinus rhythm with the identical sequence to that during VT. In the remaining five patients, the diastolic potential could not be detected, and a single fused P2 was recorded only at the VT exit site. Successful ablation was performed at this site in all five patients.

CONCLUSIONS

This study demonstrates that P1 and P2 are critical potentials in a circuit of verapamil-sensitive ILVT and suggests the presence of a macroreentry circuit involving the normal Purkinje system and the abnormal Purkinje tissue with decremental property and verapamil-sensitivity.

MACVIA-ARIA Sentinel NetworK for allergic rhinitis (MASK-rhinitis): the new generation guideline implementation

Several unmet needs have been identified in allergic rhinitis: identification of the time of onset of the pollen season, optimal control of rhinitis and comorbidities, patient stratification, multidisciplinary team for integrated care pathways, innovation in clinical trials and, above all, patient empowerment. MASK-rhinitis (MACVIA-ARIA Sentinel NetworK for allergic rhinitis) is a simple system centred around the patient which was devised to fill many of these gaps using Information and Communications Technology (ICT) tools and a clinical decision support system (CDSS) based on the most widely used guideline in allergic rhinitis and its asthma comorbidity (ARIA 2015 revision). It is one of the implementation systems of Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA). Three tools are used for the electronic monitoring of allergic diseases: a cell phone-based daily visual analogue scale (VAS) assessment of disease control, CARAT (Control of Allergic Rhinitis and Asthma Test) and e-Allergy screening (premedical system of early diagnosis of allergy and asthma based on online tools). These tools are combined with a clinical decision support system (CDSS) and are available in many languages. An e-CRF and an e-learning tool complete MASK. MASK is flexible and other tools can be added. It appears to be an advanced, global and integrated ICT answer for many unmet needs in allergic diseases which will improve policies and standards.

Enantioseparation of selected chiral sulfoxides using polysaccharide-type chiral stationary phases and polar organic, polar aqueous-organic and normal-phase eluents

HPLC enantioseparation of selected chiral sulfoxides was studied using cellulose and amylose phenylcarbamate derivatives as chiral stationary phases (CSPs). The contributions of various functional groups of a chiral analyte as well as the polysaccharide derivatives in the analyte retention and chiral recognition were evaluated. A very high enantioseparation factor exceeding 110 was observed in the enantioseparation of 2-(benzylsulfinyl)benzamide (BSBA) on cellulose tris(3,5-dichlorophenylcarbamate) (CDCPC) CSP by using 2-propanol as a mobile phase. The enantiomer elution order was opposite on cellulose and amylose phenylcarbamates. For the polysaccharide-type CSPs, pure alcohols such as methanol, ethanol and 2-propanol represent a valuable alternative to more common alcohol-hydrocarbon and reversed-phase eluents.

Identification of ISC1 (YER019w) as inositol phosphosphingolipid phospholipase C in Saccharomyces cerevisiae

Sphingolipids have emerged as novel bioactive mediators in eukaryotic cells including yeast. It has been proposed that sphingomyelin (SM) hydrolysis and the concomitant generation of ceramide are involved in various stress responses in mammalian cells. The yeast Saccharomyces cerevisiae has inositol phosphosphingolipids (IPS) instead of SM and glycolipids, and synthesis of IPS is indispensable to its growth. Although the genes responsible for the synthesis of IPS have been identified, the gene(s) for the degradation of IPS has not been reported. Here we show that ISC1 (YER019w), which has homology to bacterial neutral sphingomyelinase (SMase), encodes IPS phospholipase C (IPS-PLC). First, we observed that overexpression of ISC1 greatly increased neutral SMase activity, and this activity was dependent on the presence of phosphatidylserine. Cells deleted in ISC1 demonstrated negligible neutral SMase activity. Because yeast cells have IPS instead of SM, we investigated whether IPS are the physiologic substrates of this enzyme. Lysates of ISC1-overexpressing cells demonstrated very high PLC activities on IPS. Deletion of ISC1 eliminated endogenous IPS-PLC activities. Labeling yeast cells with [(3)H]dihydrosphingosine showed that IPS were increased in the deletion mutant cells. This study identifies the first enzyme involved in catabolism of complex sphingolipids in S. cerevisiae.