bluuebunny/crossref_metadata_2025 huggingface dataset:
Absence of Smooth Muscle Actin-Positive Pericyte Coverage of Tumor Vessels Correlates with Hematogenous Metastasis and Prognosis of Colorectal Cancer Patients
Authors: Yonenaga Yoshikuni , Mori Akira , Onodera Hisashi , Yasuda Seiichi , Oe Hideaki , Fujimoto Akihisa , Tachibana Tsuyoshi , Imamura Masayuki
Published: August 2005

Objectives: Immature microvessels, which are not covered by pericytes, are irregular and leaky. We hypothesized that tumor cells can penetrate immature microvessels more easily than mature microvessels. In this study, we investigated the maturation of angiogenesis by the immunohistochemical staining of colorectal cancer specimens and determined the correlation between the microvessel count or the maturity of microvessels and clinicopathological variables. Methods: Ninety-two surgical specimens from our department were used. Double immunostaining of endothelial cells with anti-CD34 antibody and pericytes with anti-α-smooth muscle actin antibody was performed. The microvessel density (MVD) and microvessel pericyte coverage index (MPI) as an index of microvessel maturation were evaluated. Results: The MVD showed a significant positive correlation with tumor size, depth of invasion and Dukes’ stage. The MPI showed a significant positive correlation with the histological differentiation of the tumor tissues and distant metastasis at the time of operation. The high MVD group (≧26.0, n = 50) tended to have a poorer prognosis than the low MVD group (<26.0, n = 42) (p = 0.097). Next, the 50 patients in the high MVD group were classified into two subgroups of high MPI (≧78.1%, n = 25) and low MPI (<78.1%, n = 25). MPI showed a significant negative correlation with hematogenous metastasis, and the low MPI group demonstrated a significantly poorer survival than the high MPI group (p = 0.040). Conclusions: These findings demonstrate that immature neovascularization was observed in poorly differentiated tumors and was correlated with metastasis, resulting in a poorer prognosis. Taken together, not only microvessel density but also vascular maturation were crucial factors for colorectal cancer patients.
Prognostic Significance of Endogenous Adhesion/Growth-Regulatory Lectins in Lung Cancer
Authors: Szöke Tamas , Kayser Klaus , Baumhäkel Jan-Dirk , Trojan Imre , Furak Jozsef , Tiszlavicz Laszlo , Horvath Akos , Szluha Kornelia , Gabius Hans-Joachim , Andre Sabine
Published: August 2005

Objective: To determine the expression of endogenous adhesion/growth-regulatory lectins and their binding sites using labeled tissue lectins as well as the binding profile of hyaluronic acid as an approach to define new prognostic markers. Methods: Sections of paraffin-embedded histological material of 481 lungs from lung tumor patients following radical lung excision processed by a routine immunohistochemical method (avidin-biotin labeling, DAB chromogen). Specific antibodies against galectins-1 and -3 and the heparin-binding lectin were tested. Staining by labeled galectins and hyaluronic acid was similarly visualized by a routine protocol. After semiquantitative assessment of staining, the results were compared with the pT and pN stages and the histological type. Survival was calculated by univariate and multivariate methods. Results: Binding of galectin-1 and its expression tended to increase, whereas the parameters for galectin-3 decreased in advanced pT and pN stages at a statistically significant level. The number of positive cases was considerably smaller among the cases with small cell lung cancer than in the group with non-small-cell lung cancer, among which adenocarcinomas figured prominently with the exception of galectin-1 expression. Kaplan-Meier computations revealed that the survival rate of patients with galectin-3-binding or galectin-1-expressing tumors was significantly poorer than that of the negative cases. In the multivariate calculations of survival lymph node metastases (p < 0.0001), histological type (p = 0.003), galectin-3-binding capacity (p = 0.01), galectin-3 expression (p = 0.03) and pT status (p = 0.003) proved to be independent prognostic factors, not correlated with the pN stage. Conclusion: The expression and the capacity to bind the adhesion/growth regulatory galectin-3 is defined as an unfavorable prognostic factor not correlated with the pTN stage.
Renal Protective Effects of the Renin-Angiotensin-Aldosterone System Blockade: From Evidence-Based Approach to Perspectives
Authors: Tylicki Leszek , Larczynski Wojciech , Rutkowski Bolesław
Published: August 2005

The renin-angiotensin-aldosterone system (RAAS) blockade is currently the best-documented treatment strategy to delay the progression of chronic nephropathies. Angiotensin-converting enzyme inhibitors (CEIs) or angiotensin II type 1 receptor antagonists (ARBs) should be used in every normotensive and hypertensive patient with chronic proteinuric nephropathy of both diabetic and non-diabetic origin. The therapy should be initiated as early as possible, bearing in mind that the renoprotection is more effective if used before overt proteinuria or a reduction in kidney function is present. The therapy should be offered to all patients, regardless of renal function, as well as to subjects with severely impaired glomerular filtration. CEIs and ARBs should be administered in therapeutic doses as high as possible to achieve maximal possible proteinuria reduction and systemic blood pressure target <130/80 mm Hg, and 125/75 mm Hg in those subjects with renal insufficiency who present with proteinuria above 1 g/24 h. The combined therapy with the concomitant use of CEIs and ARBs should be offered to all patients with proteinuric non-diabetic chronic nephropathies who do not achieve full and persistent remission of proteinuria with CEI or ARB alone. The article reviews an evidence-based approach on the use of RAAS-inhibiting agents in kidney diseases, considers treatment strategies in different clinical situations and discusses some perspectives related to the implementation of the RAAS blockade in renal protection.
Association between the Catechol O-Methyltransferase Val108/158Met Polymorphism and Alexithymia
Authors: Ham Byung-Joo , Lee Min-Soo , Lee Young-Mee , Kim Meyoung-Kon , Choi Myoung-Jin , Oh Kang-Seob , Jung Han Yong , Lyoo In Kyoon , Choi Ihn-Geun
Published: August 2005

It has been suggested that the characteristics of alexithymia result from deficits in frontal lobe functioning, and the prefrontal cortex is particularly dependent on the catechol O-methyltransferase (COMT) pathway. We investigated the relationship between COMT Val108/158Met, serotonin transporter coding sequence (5-HT transporter gene-linked polymorphic region; 5-HTTLPR) polymorphisms, and alexithymia.The study sample comprised 109 students at the Korea University. All participants were tested using the 20-item Toronto Alexithymia Scale (TAS-20). They were genotyped for COMT Val108/158Met and 5-HTTLPR polymorphisms. Genotyping was analyzed using polymerase chain reaction. Subjects with Val/Val genotype had significantly higher TAS-20 scores than those with Met/Met or Met/Val genotypes. However, there was no significant relationship between the 5-HTTLPR genotype and TAS-20 scores. This indicates a possible association between the COMT Val108/158Met gene polymorphism and alexithymia.
Serotonin Receptor 2A Gene Polymorphism (–1438A/G) and Short-Term Treatment Response to Citalopram
Authors: Choi Myoung-Jin , Kang Rhee-Hun , Ham Byung-Joo , Jeong Han-Yong , Lee Min-Soo
Published: August 2005

The 5-HTR2A gene is a candidate gene for influencing the clinical response to antidepressant treatment. The purpose of this study was to determine the relationship between the –1438A/G polymorphism in the 5-HTR2A gene and the response to citalopram in a Korean population with major depressive disorder (MDD). Citalopram was administered for 4 weeks to the 71 patients who completed this study. We found significant differences in genotype, allele, and carrier distribution between the normal group and MDD patients (genotypes: χ2 = 6.473, d.f. = 2, p = 0.039; alleles: χ2 = 5.589, d.f. = 1, p = 0.018; OR = 0.618, 95% CI = 0.414–0.922; allele carriers: χ2 = 5.383, d.f. = 1, p = 0.020; OR = 0.473, 95% CI = 0.249–0.879). The frequency of the –1438G allele was much higher in MDD patients than in the normal group (allele carriers: χ2 = 5.383, d.f. = 1, p = 0.020; OR = 0.473, 95% CI = 0.249–0.879). There were also significant differences in response to citalopram according to the –1438A/G variation of 5-HTR2A in MDD patients. The group of remitters carried a higher frequency of the GG allele than of the AA and AG alleles. More of nonremitters carried the A allele than were without it (genotype: χ2 = 8.016, p = 0.018; allele carrier: χ2 = 4.512, p = 0.034; OR = 0.324, 95% CI = 0.112–0.936). The response to citalopram differed with the –1438A/G polymorphism genotype and allele carriers. The –1438G/–1438G genotype appeared to be associated with a better response to citalopram, with especially the G allele being related to core depressive symptoms and psychic anxiety improvement (p<0.05). These results suggest that the G allele of the –1438A/G polymorphism in the 5-HTR2A gene is associated with MDD, and that patients with –1438G/–1438G have a better response to citalopram treatment than patients with –1438A/–1438A or –1438A/–1438G.
Importance of Databases in Experimental and Clinical Allergology
Authors: Mari Adriano
Published: August 2005

Information technology (IT) is leading us to reconsider some of the approaches we have been using in both basic research and clinical work in allergology. Resources mainly coming from the advent of the Internet are further amplified by the parallel development of other new tools, such as molecular biology and nanotechnology. These three powerful tools are now available and are cross-linked to a certain degree to express their power when applied to biomedical fields. Bioinformatics applied to allergy simplifies our way of handling an increasing wealth of knowledge. This review assesses the current status of allergen databases that are mainly dedicated to sequence homology collection for computational purposes. Whether or not they integrate features that are now typical of IT in other biomedical fields is analyzed as well. The results of these analyses are discussed with a view to the critical need of integrating biochemical data with clinical, epidemiological information and how this goal can be reached by the use of proteomic microarrays for IgE detection. Future directions for a more comprehensive use of allergen databases are proposed.
Expression of c-Ets1 Protein in Normal Human Placenta
Authors: Takai Noriyuki , Ueda Tami , Narahara Hisashi , Miyakawa Isao
Published: August 2005

Background: The proto-oncogene product c-Ets1 is a transcriptional factor that controls the expression of a number of genes involved in extracellular matrix remodeling such as stromelysin-1 (matrix metalloproteinase-3; MMP-3), collagenase-1, and urokinase-type plasminogen activator (u-PA). To elucidate the involvement of c-Ets1 in the invasive pathway of the trophoblasts, we analyzed c-Ets1 protein expression in placentas by fluorescent immunohistochemistry and Western blot analysis. Methods: We analyzed serial frozen sections for c-Ets1 protein expression of the chorionic villi and cell column in the first trimester and the basal plate of placenta and amniotic membranes in the third trimester by fluorescent immunohistochemistry. Moreover, we examined the expression of c-Ets1 in the first and the third trimester by Western blot analysis. Results: In the first trimester, c-Ets1 was strongly expressed in the cytoplasm of cytotrophoblasts. Moreover, the cell column that invaded the endometrium had the strongest expression of c-Ets1. In the third trimester, c-Ets1 was detected in both cytoplasm and nucleus of the invading trophoblasts in the basal plate. Furthermore, c-Ets1 was expressed in both cytoplasm and nucleus of the trophoblasts in amniotic membrane. Western blotting revealed that c-Ets1 expressions in the first trimester were stronger than those in the third trimester. Conclusion: Our results demonstrate that c-Ets1 expression in normal human placenta correlates to the invasive behavior of the trophoblasts, probably by activating the transcription of matrix-degrading MMPs, including MMP-3, collagenase-1, and u-PA.
Association of Expression of Receptor for Advanced Glycation End Products and Invasive Activity of Oral Squamous Cell Carcinoma
Authors: Bhawal Ujjal K. , Ozaki Yoshie , Nishimura Masahiro , Sugiyama Masaru , Sasahira Tomonori , Nomura Yuji , Sato Fuyuki , Fujimoto Katsumi , Sasaki Nobuyuki , Ikeda Masa-Aki , Tsuji Koichiro , Kuniyasu Hiroki , Kato Yukio
Published: August 2005

Objectives: The receptor for advanced glycation end products (RAGE) is a newly recognized factor regulating cancer cell invasion and metastasis. Nevertheless, the involvement of RAGE in the development and progression of oral squamous cell carcinomas has not been elucidated. This study investigated the expression of RAGE in ten oral squamous cell carcinoma cell lines including primary and metastatic cell lines and its association with invasion and metastasis. Methods: Reverse transcriptase-polymerase chain reaction, antisense phosphorothioate (S)-oligodeoxynucleotide assay, preparation of antibody, immunohistochemical staining, immunoblot analysis, migration assay, in vitro invasion assay, and wound-healing assay were used. Results: RAGE protein expression of metastatic cancer cells treated with RAGE antisense S-oligodeoxynucleotide was significantly reduced compared to that of sense S-oligodeoxynucleotide-treated cells. The migration assay showed that invasive activity was significantly reduced in metastatic cancer cells treated with RAGE antisense S-oligodeoxynucleotide. Similarly, during invasion assays, numbers of invading cells were also reduced with the addition of RAGE antisense S-oligodeoxynucleotide-treated cells. A wound-healing assay showed that only a few RAGE antisense S-oligodeoxynucleotide-treated cancer cells migrated into the scraped area, whereas sense S-oligodeoxynucleotide-treated cells showed many budding nests in the scraped area of the metastatic cell lines. Immunohistochemically, oral squamous cell carcinoma cells in the tumour mesenchymal border were often immunopositive, whereas basal cells in the normal mucosa were scarcely positive. Conclusions: These results suggest that RAGE expression appears to be closely associated with the invasiveness of oral squamous cell carcinoma and represents a promising candidate for assessing the future therapeutic potential in treating patients with oral carcinoma.
Kidney Transplantation and Gender Disparity
Authors: Jindal Rahul M. , Ryan John J. , Sajjad Imran , Murthy Madhukiran H. , Baines Lyndsay S.
Published: August 2005

Gender inequity in access to hemodialysis and kidney transplantation has created a public health crisis in the US. Women have a lower chance of receiving hemodialysis and kidney transplant than men, but they constitute the majority of living kidney donors. Research has shown that economic factors such as greater income of men may encourage females to be donors; while gender-bias on part of physicians or institutions, lack of social support networks and differences in health-seeking behaviors compared to men are cited as reasons for this imbalance. We suggest various strategies to improve participation of women in the transplant process by education; raising awareness by publishing gender-specific data for dialysis and transplant centers; education and workshops to eliminate gender-bias within institutions and health-care providers and establishment of gender-specific support groups. Transplant teams that are more sensitive to the social complexities of women’s lives may lead to increased understanding of the effects of renal disease and indicate measures that need to be in place in order to address this gender disparity in the treatment of renal failure. Research needs to be done to elucidate the underlying medical, societal or psychological processes that lead to gender bias in the field of kidney transplantation.
Release of Interleukin-6 and Its Soluble Receptors by Activated Peripheral Blood Monocytes Is Elevated in Hypocholesterolemic Hemodialysis Patients
Authors: Tsirpanlis George , Chatzipanagiotou Stylianos , Boufidou Fotini , Kordinas Vasileios , Alevyzaki Fotini , Zoga Margarita , Kyritsis Ilias , Ioannou Dimitris , Fatourou Alexandra , Nicolaou Chrysoula
Published: August 2005

Background: A reverse association between cholesterol level and cardiovascular disease mortality is observed in hemodialysis (HD) patients; this paradoxical relationship may be explained by the coexistence of inflammation. Interleukin-6 (IL-6) is a central regulator of inflammation; its action is augmented by the soluble IL-6 receptor (sIL-6R) and inhibited by the soluble gp130 (sgp130). In order to investigate the potential association of inflammation with cholesterol levels in the HD population, release of soluble IL-6 components by peripheral blood mononuclear cells (PBMCs) was measured in two groups of HD patients with distinctly different lipid profile and in a control group. Methods: Twenty-two HD patients with low serum cholesterol (range 85–171 mg/dl), 23 HD patients with high cholesterol (189–342 mg/dl) and 21 normolipidemic non-renal failure subjects were enrolled in the study. IL-6, sIL-6R and sgp130 were measured by ELISA in the serum and in the supernatant collected from cell cultures of activated or resting PBMCs isolated from all three groups. Results: Serum IL-6 and sgp130 level was higher while sIL-6R was lower in both groups of HD patients compared to the control group. The ex-vivo release of the IL-6 and sgp130 by unstimulated PBMCs did not differ significantly between the three groups but that of the sIL-6R was higher in non-renal failure than in hypercholesterolemic HD subjects. Production of sIL-6R by stimulated PBMCs was higher in low-cholesterol HD patients (p < 0.001) and the same was valid for the sgp130 release (p = 0.034). Release of IL-6 by activated PBMCs was higher in the low-cholesterol compared to the high-cholesterol HD patients group (p = 0.011 for post hoc test). Major serum lipid fractions were inversely correlated to IL-6 and sIL-6R production from stimulated PBMCs in HD but not in non-renal failure subjects. Finally, release of the sgp130 by PBMCs was significantly reduced in 13 hypertriglyceridemic – and hypercholesterolemic – HD patients. Conclusion: Production of soluble components of a crucial pro-inflammatory and potentially atherogenic cytokine, namely the IL-6, by stimulated PBMCs appears to be inversely correlated with the serum cholesterol levels in HD patients.
Endothelial Cell Activation by IL-1β in the Presence of Fibrinogen Requires αVβ3
Authors: Sahni Abha , Sahni Sanjeev K. , Francis Charles W.
Published: August 2005

Objective—The purpose of this study was to investigate the receptor requirements for enhanced IL-1β–induced secretion of nitric oxide (NO) by endothelial cells (ECs) in the presence of fibrinogen.

Methods and Results—ECs were exposed to IL-1β with or without fibrinogen and NO was measured as nitrite. NO production by EC exposed to fibrinogen (0.3±0.1 μmol/L) was comparable concentration to control (0.2±0.1 μmol/L), but IL-1β significantly increased NO production (0.8±0.1 μmol/L), and the combination of both fibrinogen and IL-1β resulted in a further increase to 2.2±0.2 μmol/L (P<0.002). 7E3 or LM609, antibodies to αvβ3, inhibited NO production stimulated by fibrinogen-bound IL-1β to 0.2±0.1 μmol/L (P<0.001) or 0.2±0.03 μmol/L (P<0.0001), respectively. These levels were comparable to control and significantly less than with IL-1β (P<0.002). EC or fibroblasts exposed to both fibrinogen and IL-1β, but not vitronectin and IL-1β, demonstrated positive Western blotting for αVβ3after immunopurification with anti- IL-1R, indicating specific association between αvβ3and IL-1R. Dual immunofluorescence also revealed colocalization of αvβ3and IL-1R only when the cells were exposed to both fibrinogen and IL-1β.

Conclusion—The enhanced NO production by ECs in the presence of fibrinogen-bound IL-1β requires the coordinated effects of colocalized αVβ3and IL-1R.
Rho/Rho-Kinase Pathway Contributes to C-Reactive Protein–Induced Plasminogen Activator Inhibitor-1 Expression in Endothelial Cells
Authors: Nakakuki Tetsuya , Ito Masaaki , Iwasaki Hitoshi , Kureishi Yasuko , Okamoto Ryuji , Moriki Nobuyuki , Kongo Mariko , Kato Shinya , Yamada Norikazu , Isaka Naoki , Nakano Takeshi
Published: August 2005

Objective—Rho/Rho-kinase pathway plays pivotal roles in cardiovascular diseases including arteriosclerosis and hypertension. Recently it has become evident that C-reactive protein (CRP), a powerful marker for cardiovascular events, has direct proatherothrombotic effects on vascular cells. However, its molecular mechanism has not been fully investigated. We examined the involvement of Rho/Rho-kinase signaling in CRP-induced plasminogen activator inhibitor-1 (PAI-1) expression in bovine aortic endothelial cells (BAECs).

Methods and Results—PAI-1 expression was determined by Western blotting. RhoA activation was determined by an affinity pull-down assay using Rho-binding fragment of rhotekin. NF-κB activity was determined using the luciferase reporter gene. Incubation of BAECs with human recombinant CRP (≥25 μg/mL) induced a significant increase in PAI-1 expression. Stimulation of BAECs with CRP significantly increased RhoA activation. Pretreatment with TAT-C3 (a membrane-permeable RhoA inhibitor) and Y-27632 (Rho-kinase inhibitor) significantly inhibited CRP-induced PAI-1 expression. NF-κB activity was markedly enhanced by CRP and pretreatment with Y-27632 inhibited its activation. Parthenolide, SN50, and BAY 11-7082 (NF-κB inhibitors) significantly blocked CRP-mediated PAI-1 expression.

Conclusions—These data suggested that CRP activates Rho/Rho-kinase signaling, which in turn activates NF-κB activity, resulting in PAI-1 expression in BAEC. These observations provide evidence for the possible involvement of Rho/Rho-kinase signaling in CRP-induced atherothrombogenesis.
Mechanisms of Endothelial Differentiation in Embryonic Vasculogenesis
Authors: Ferguson J.E. , Kelley Rusty W. , Patterson Cam
Published: August 2005

The formation of new blood vessels in the adult organism not only contributes to the progression of diseases such as cancer and diabetic retinopathy but also can be promoted in therapeutic approaches to various ischemic pathologies. Because many of the signals important to blood vessel development during embryogenesis are recapitulated during adult blood vessel formation, much work has been performed to better-understand the molecular control of endothelial differentiation in the developing embryo. In this review, we describe the current understanding of where endothelial differentiation from pluripotent progenitor cells occurs during development, how this process is controlled at the molecular level, and what model systems can be used to investigate the earliest steps of blood vessel formation.
Expression of the Pregnane X Receptor in Mice Antagonizes the Cholic Acid–Mediated Changes in Plasma Lipoprotein Profile
Authors: Masson David , Lagrost Laurent , Athias Anne , Gambert Philippe , Brimer-Cline Cynthia , Lan Lubin , Schuetz John D. , Schuetz Erin G. , Assem Mahfoud
Published: August 2005

Objective—Modification of lipoprotein metabolism by bile acids has been mainly explained by activation of the farnesyl X receptor (FXR). The aim of the present study was to determine the relative contribution of the pregnane X receptor (PXR), another bile acid–activated nuclear receptor to changes in plasma lipoprotein profile.

Methods and Results—Wild-type mice, Pxr-deficient mice, and Pxr-null mice expressing human PXR (Pxr-null SXR-Tg mice) were fed a cholic acid–containing diet, and consequences on plasma lipoprotein profiles and target gene expression were assessed. Cholic acid produced significant decreases in high-density lipoprotein (HDL) cholesterol, plasma apolipoprotein (apo)A-I and hepatic apoA-I mRNA in wild-type mice. Interestingly, the effect of cholic acid was significantly more pronounced in Pxr-deficient mice, indicating that PXR contributes to the weakening of the effect of bile acids on lipoprotein metabolism. Reciprocally, changes in HDL/apoA-I profiles were abolished in Pxr-null SXR-Tg mice in which PXR-responsive genes, particularly those involved in bile acid detoxification were readily activated after cholic acid treatment.

Conclusion—PXR expression in mice antagonizes the cholic acid–mediated downregulation of plasma HDL cholesterol and apoA-I, and magnification of PXR/SXR-mediated changes may constitute a new mean to counteract the effects of bile acids on plasma lipoproteins.
C-Reactive Protein Decreases Tissue Plasminogen Activator Activity in Human Aortic Endothelial Cells
Authors: Singh Uma , Devaraj Sridevi , Jialal Ishwarlal
Published: August 2005

Objective—

C-reactive protein (CRP) can promote atherothrombosis by decreasing endothelial nitric oxide synthase and prostacyclin, and by stimulating both plasminogen activator inhibitor-1 in endothelial cells and tissue factor in mononuclear cells. Plasminogen activator-1, a marker of fibrinolysis, is the primary inhibitor of tissue plasminogen activator (tPA). Thus, we tested the effect of CRP on tPA in human aortic endothelial cells.

Methods and Results—

Incubation of human aortic endothelial cells with CRP (≥12.5 μg/mL) significantly decreased tPA antigen and activity. Adenyl cyclase inhibitors, an endothelin receptor antagonist, superoxide dismutase, and a nitric oxide donor failed to reverse the effect of CRP on tPA. CRP increased interleukin (IL)-1β and tumor necrosis factor (TNF)-α. Neutralization of both IL-1β and TNFα reversed the inhibition of tPA by CRP. Furthermore, in volunteers that have high CRP levels, euglobulin clot lysis time was significantly increased compared with those that have low CRP levels, providing further evidence that high CRP levels are associated with a procoagulant state.

Conclusions—

CRP inhibits tPA activity via generation of proinflammatory cytokines (IL-1β and TNFα). This study provides additional novel data that CRP is a procoagulant and has implications for atherothrombosis.
Impact of Treatment With Protease Inhibitors on Aortic Stiffness in Adult Patients With Human Immunodeficiency Virus Infection
Authors: Schillaci Giuseppe , De Socio Giuseppe V.L. , Pirro Matteo , Savarese Gianluca , Mannarino Massimo R. , Baldelli Franco , Stagni Giuliano , Mannarino Elmo
Published: August 2005

Background—

The role of antiretroviral therapy in acceleration of atherosclerosis in patients with human immunodeficiency virus (HIV) infection is controversial. We hypothesized that aortic stiffness, an early marker of arteriosclerosis, may be increased in HIV patients treated with protease inhibitors.

Methods and Results—

In 32 HIV-infected patients treated with protease inhibitors and 32 age-, sex-, and blood pressure–matched HIV-uninfected control subjects, we obtained aortic pulse wave velocity and central aortic pressure waveform, from which aortic augmentation was calculated. HIV patients had a higher aortic pulse wave velocity (7.6±1.1 versus 6.8±1.2 m×s
−1
,
P
=0.015) and aortic augmentation (6.8±5 versus 4.6±4 mm Hg,
P
=0.037) than control subjects. Age and HIV infection (both
P
<0.05) independently predicted aortic pulse wave velocity when a consistent number of cardiovascular risk factors was simultaneously controlled for. The cumulative duration of treatment was a predictor of aortic pulse wave velocity, each 5 years of treatment duration being independently related to a 1.35 m×s
−1
increase in pulse wave velocity.

Conclusions—

Aortic stiffness is increased in HIV-positive individuals receiving antiretroviral therapy including a protease inhibitor. Pulse wave velocity increases with longer exposure to protease inhibitors. We hypothesize that arteriosclerosis is a side effect of antiretroviral treatment including a protease inhibitor.
α-Lipoic Acid–Induced Heme Oxygenase-1 Expression Is Mediated by Nuclear Factor Erythroid 2-Related Factor 2 and p38 Mitogen-Activated Protein Kinase in Human Monocytic Cells
Authors: Ogborne Richard M. , Rushworth Stuart A. , O’Connell Maria A.
Published: August 2005

Objective—Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme catabolism, plays a protective role in the vascular system. HO-1 induction inhibits cytokine production in macrophages. Antioxidants induce HO-1 expression in various cell types. α-lipoic acid (ALA), a thiol-containing dietary antioxidant, exhibits protective effects in vascular disease and induces anti-inflammatory effects in monocytes. This study examined the effects of ALA on HO-1 expression in human monocytic cells.

Methods and Results—ALA time and dose-dependently induced HO-1 mRNA expression in THP-1 cells, with peak expression at 4 hours and returning to baseline by 24 hours. This correlated with an increase in HO-1 protein expression. ALA stimulated translocation of the transcription factor nuclear factor-erythroid 2–related factor 2 (Nrf2) into the nucleus and binding to a human HO-1 antioxidant response element (ARE) by 30 minutes. A dominant-negative Nrf2 inhibitor reduced ALA-induced HO-1 mRNA expression by 66%. Pretreatment with SB203580, a p38 mitogen-activated protein kinase inhibitor, reduced ALA-induced HO-1 mRNA expression by 75% and inhibited ALA-induced Nrf2 binding to the HO-1 ARE.

Conclusions—These results demonstrate that ALA induces HO-1 expression in THP-1 monocytic cells via Nrf2 and p38. Further studies are required to investigate whether the protective effects of ALA in monocytes are mediated by HO-1.
A Paracrine Loop Between Adipocytes and Macrophages Aggravates Inflammatory Changes
Authors: Suganami Takayoshi , Nishida Junko , Ogawa Yoshihiro
Published: August 2005

Objective—

Weight gain is associated with infiltration of fat by macrophages, suggesting that they are an important source of inflammation in obese adipose tissue. Here we developed an in vitro coculture system composed of adipocytes and macrophages and examined the molecular mechanism whereby these cells communicate.

Methods and Results—

Coculture of differentiated 3T3-L1 adipocytes and macrophage cell line RAW264 results in the marked upregulation of proinflammatory cytokines, such as tumor necrosis factor α (TNF-α), and the downregulation of the antiinflammatory cytokine adiponectin. Such inflammatory changes are induced by the coculture without direct contact, suggesting the role of soluble factors. A neutralizing antibody to TNF-α, which occurs mostly in macrophages, inhibits the inflammatory changes in 3T3-L1, suggesting that TNF-α is a major macrophage-derived mediator of inflammation in adipocytes. Conversely, free fatty acids (FFAs) may be important adipocyte-derived mediators of inflammation in macrophages, because the production of TNF-α in RAW264 is markedly increased by palmitate, a major FFA released from 3T3-L1. The inflammatory changes in the coculture are augmented by use of either hypertrophied 3T3-L1 or adipose stromal vascular fraction obtained from obese
ob/ob
mice.

Conclusions—

We postulate that a paracrine loop involving FFAs and TNF-α between adipocytes and macrophages establishes a vicious cycle that aggravates inflammatory changes in the adipose tissue.
Tissue-Specific Hemostasis in Mice
Authors: Mackman Nigel
Published: August 2005

Blood coagulation is essential to maintain hemostasis in organisms with a vascular network. Formation of a fibrin-rich clot at a site of vessel injury is a highly complex process that is orchestrated by the coagulation protease cascade. This cascade is regulated by 3 major anticoagulant pathways. Removal of a clot is mediated by the fibrinolytic system. Defects in the regulation of clot formation lead to either hemorrhage or thrombosis. Tissue factor, the primary cellular initiator of blood coagulation, is a transmembrane receptor that is expressed in a tissue-specific manner. The 3 major anticoagulants are tissue factor pathway inhibitor, antithrombin, and protein C, the latter requiring a transmembrane receptor called thrombomodulin for its activation. Tissue factor pathway inhibitor and thrombomodulin are expressed by endothelial cells in a tissue-specific manner, whereas antithrombin and protein C circulate in the plasma. Fibrinolysis requires the activation of plasminogen to plasmin, which is mediated by tissue-type plasminogen activator and urokinase-type plasminogen activator. Interestingly, tissue-type plasminogen activator is expressed by a subset of endothelial cells of discrete size and location. These observations, together with the phenotypes of mice that have defects in the procoagulant, anticoagulant, and fibrinolytic pathways, indicate that hemostasis is regulated in a tissue-specific manner.
Regulation of Vein Graft Hyperplasia by Survivin, an Inhibitor of Apoptosis Protein
Authors: Wang Grace J. , Sui Xin Xin , Simosa Hector F. , Jain Mukesh K. , Altieri Dario C. , Conte Michael S.
Published: August 2005

Objective—

Survivin (SVV) is an inhibitor of apoptosis protein (IAP) that is upregulated in cancer and has recently been implicated in vascular injury. We sought to investigate the role of SVV in vein graft hyperplasia.

Methods and Results—

Adenoviral constructs expressing a dominant-negative (AdT34A) and wild-type (AdWT) SVV were used. Proliferation and apoptosis were assayed on endothelial cells (ECs) and smooth muscle cells (SMCs) from human saphenous vein. A rabbit carotid interposition vein graft model (N=31) was used, with adventitial gene transfer of SVV constructs. In vitro, overexpression of SVV was associated with protection from cytokine-induced apoptosis in ECs and SMCs; conversely, AdT34A directly induced apoptosis in these cells. SMC proliferation was increased by AdWT infection, whereas AdT34A reduced proliferation; both effects were serum-dependent. Expression of platelet-derived growth factor (PDGF) in SMCs was regulated by functional SVV expression in analogous fashion. In vivo, proliferation and apoptosis (7 days), as well as wall thickness (30 days), were modified by adenoviral-mediated SVV expression. Adventitial angiogenesis was regulated by the SVV-expressing constructs in a fashion parallel to wall thickness changes.

Conclusions—

SVV is a critical regulator of multiple processes, including proliferation, apoptosis, and angiogenesis, that determine the remodeling response of vein grafts following arterialization.
Ethnic Differences in Arterial Responses and Inflammatory Markers in Afro-Caribbean and Caucasian Subjects
Authors: Kalra Lalit , Rambaran Curtis , Chowienczyk Philip , Goss David , Hambleton Ian , Ritter James , Shah Ajay , Wilks Rainford , Forrester Terrence
Published: August 2005

Objective—

Small vessel disease is more common in Afro-Caribbeans than Caucasians. We investigated underlying differences in metabolic, inflammatory, and vascular responses that may predispose Afro-Caribbeans to small vessel pathology.

Methods and Results—

Seventy-eight Afro-Caribbeans aged 35–75 years, with no vascular disease or medications, were compared with 82 matched Caucasians for metabolic variables, fasting insulin, interleukin 6, tumor necrosis factor (TNF) α, and cytoplasmic repressor protein levels. Carotid intima media thickness (CIMT) was measured ultrasonographically. Small vessel function was assessed by measuring the absolute change from baseline in the reflectance index (RI) of the digital volume pulse during IV infusion of albuterol (5 μg/min, ΔRI
ALB
) and glyceryl tri nitrate (5 μg/min, ΔRI
GTN
). Large artery elasticity was measured as the stiffness index (SI) and derived from the time to pulse wave reflection adjusted for subject height. Afro-Caribbeans had significantly higher diastolic blood pressure (80.3 versus 77.6 mm Hg;
P
=0.033), fasting insulin (14.0 versus 10.6 μU/mL;
P
=0.026), TNF-α (6.7 versus 4.3; pg/mL;
P
=0.001), and interleukin 6 (2.3 versus 1.5 pg/mL;
P
=0.036) levels compared with Caucasians. CIMT was greater (0.81±0.20 versus 0.75±0.18 mm;
P
=0.02) and small vessel reactivity attenuated (mean ΔRI
ALB
6.8±8.0% versus 12.3±8.%;
P
<0.0001) in Afro-Caribbeans, but their large artery elasticity (mean index of large artery stiffness 9.9 versus 9.7 m/s;
P
=0.48) was comparable with Caucasians. CIMT was independently associated with an index of large artery stiffness (β=0.03;
P
=0.002) in Caucasians but not in Afro-Caribbeans. There were independent relationships among Afro-Caribbean ethnicity, TNF-α, and insulin levels.

Conclusions—

Selective impairment of small artery function may contribute to excess small vessel disease in Afro-Caribbeans.
The Use of Achilles Tendon Sonography to Distinguish Familial Hypercholesterolemia from Other Genetic Dyslipidemias
Authors: Junyent Mireia , Gilabert Rosa , Zambón Daniel , Núñez Isabel , Vela María , Civeira Fernando , Pocoví Miguel , Ros Emilio
Published: August 2005

Objective—

Achilles tendon (AT) xanthomas, specific for familial hypercholesterolemia (FH), may be clinically undetectable. We assessed the usefulness of AT sonography in the diagnosis of FH.

Methods and Results—

Sonographic AT characteristics were evaluated in 127 subjects with FH (81 genetically ascertained), 84 familial combined hyperlipidemia, 79 polygenic hypercholesterolemia, and 88 normolipidemic controls. Abnormal echostructure (sonographic xanthoma) was noted only in FH. AT thickness was higher (
P
<0.001) in FH men and women compared with all of the other groups and, in FH mutation carriers but not in others, correlated positively with low-density lipoprotein cholesterol (
r
=0.345;
P
<0.001) and negatively with high-density lipoprotein cholesterol (
r
=−0.265,
P
=0.015). Thickness thresholds for the diagnosis of FH with specificity >80%, as were derived from receiver operating curves, were 5.3 and 5.7 mm in men < and >45 years, and 4.8 and 4.9 mm in women < and >50 years, respectively. In FH mutation carriers, sonographic findings increased the clinical diagnosis of xanthomas from 35 (43%) to 55 (68%). Using thresholds in validation sets of 70 genetically identified FH and 54 dyslipidemic non-FH correctly classified 80% and 88%, respectively.

Conclusion—

Sonographic AT characteristics are normal in non-FH dyslipidemias. Identification of suspected FH by ultrasound using sex- and age-specific AT thickness thresholds is recommended.
Proteomic and Metabolomic Analyses of Atherosclerotic Vessels From Apolipoprotein E-Deficient Mice Reveal Alterations in Inflammation, Oxidative Stress, and Energy Metabolism
Authors: Mayr Manuel , Chung Yuen-Li , Mayr Ursula , Yin Xiaoke , Ly Lucy , Troy Helen , Fredericks Salim , Hu Yanhua , Griffiths John R. , Xu Qingbo
Published: August 2005

Objective—

Proteomics and metabolomics are emerging technologies to study molecular mechanisms of diseases. We applied these techniques to identify protein and metabolite changes in vessels of apolipoprotein E
−/−
mice on normal chow diet.

Methods and Results—

Using 2-dimensional gel electrophoresis and mass spectrometry, we identified 79 protein species that were altered during various stages of atherogenesis. Immunoglobulin deposition, redox imbalance, and impaired energy metabolism preceded lesion formation in apolipoprotein E
−/−
mice. Oxidative stress in the vasculature was reflected by the oxidation status of 1-Cys peroxiredoxin and correlated to the extent of lesion formation in 12-month-old apolipoprotein E
−/−
mice. Nuclear magnetic resonance spectroscopy revealed a decline in alanine and a depletion of the adenosine nucleotide pool in vessels of 10-week-old apolipoprotein E
−/−
mice. Attenuation of lesion formation was associated with alterations of NADPH generating malic enzyme, which provides reducing equivalents for lipid synthesis and glutathione recycling, and successful replenishment of the vascular energy pool.

Conclusion—

Our study provides the most comprehensive dataset of protein and metabolite changes during atherogenesis published so far and highlights potential associations of immune-inflammatory responses, oxidative stress, and energy metabolism.
Does Elevated Plasma Fibrinogen Increase the Risk of Coronary Heart Disease?
Authors: Smith George Davey , Harbord Roger , Milton Julie , Ebrahim Shah , Sterne Jonathan A.C.
Published: August 2005

Objective—

The purpose of this study was to assess whether a genetic variant associated with higher fibrinogen levels is associated with increased coronary heart disease (CHD) risk, as a test of the causal influence of fibrinogen on CHD.

Methods and Results—

We performed a meta-analysis of case-control and prospective studies of the G-455→A and C-148→T β-fibrinogen promoter region variants, in relation to CHD risk. The 19 studies found included 12,393 cases and 21,649 controls. Fibrinogen levels were robustly related to the genetic variants (mean increase per allele, 0.117 g/L; 95% CI, 0.091–0.142 g/L). However, the genetic variants were unrelated to CHD risk (odds ratio per allele, 0.976; 95% CI, 0.916–1.040). The predicted causal odds ratio for a 1 g/L higher plasma fibrinogen level, given the genetic variant–fibrinogen and genetic variant–CHD associations, was 0.81 (95% CI, 0.46–1.40).

Conclusions—

Although imprecise, the predicted causal effect of fibrinogen on CHD is clearly different from the odds ratio of 1.8 (95% CI, 1.6–2.0) for an increase of 1 g/L derived from a meta-analysis of observational studies. This evidence suggests that lowering the fibrinogen level may not, in itself, reduce CHD risk.
Intermittent Hypoxia Induces Hyperlipidemia in Lean Mice
Authors: Li Jianguo , Thorne Laura N. , Punjabi Naresh M. , Sun Cheuk-Kwan , Schwartz Alan R. , Smith Philip L. , Marino Rafael L. , Rodriguez Annabelle , Hubbard Walter C. , O’Donnell Christopher P. , Polotsky Vsevolod Y.
Published: August 2005

Obstructive sleep apnea, a syndrome leading to recurrent intermittent hypoxia (IH), has been associated previously with hypercholesterolemia, independent of underlying obesity. We examined the effects of experimentally induced IH on serum lipid levels and pathways of lipid metabolism in the absence and presence of obesity. Lean C57BL/6J mice and leptin-deficient obese C57BL/6J-
Lep
ob
mice were exposed to IH for five days to determine changes in serum lipid profile, liver lipid content, and expression of key hepatic genes of lipid metabolism. In lean mice, exposure to IH increased fasting serum levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, phospholipids (PLs), and triglycerides (TGs), as well as liver TG content. These changes were not observed in obese mice, which had hyperlipidemia and fatty liver at baseline. In lean mice, IH increased sterol regulatory element binding protein 1 (SREBP-1) levels in the liver, increased mRNA and protein levels of stearoyl–coenzyme A desaturase 1 (SCD-1), an important gene of TG and PL biosynthesis controlled by SREBP-1, and increased monounsaturated fatty acid content in serum, which indicated augmented SCD-1 activity. In addition, in lean mice, IH decreased protein levels of scavenger receptor B1, regulating uptake of cholesterol esters and HDL by the liver. We conclude that exposure to IH for five days increases serum cholesterol and PL levels, upregulates pathways of TG and PL biosynthesis, and inhibits pathways of cholesterol uptake in the liver in the lean state but does not exacerbate the pre-existing hyperlipidemia and metabolic disturbances in leptin-deficient obesity.
Enhanced Functional Gap Junction Neoformation by Protein Kinase A–Dependent and Epac-Dependent Signals Downstream of cAMP in Cardiac Myocytes
Authors: Somekawa Satoshi , Fukuhara Shigetomo , Nakaoka Yoshikazu , Fujita Hisakazu , Saito Yoshihiko , Mochizuki Naoki
Published: August 2005

Gap junctions (GJs) constituted by neighboring cardiac myocytes are essential for gating ions and small molecules to coordinate cardiac contractions. cAMP is suggested to be a potent stimulus for enhancement of GJ function. However, it remains elusive how cAMP potentiates the GJ of cardiomyocytes. Here we demonstrated that the gating function of GJ is enhanced by the protein kinase A (PKA)–dependent signal, and that the accumulation of connexin43 (Cx43), the most abundant Cx in myocytes, is enhanced by an exchange protein directly activated by cAMP (Epac) (Rap1 activator)–dependent signal. The gating function of GJs was analyzed by microinjected dye transfer method. The accumulation of Cx43 was analyzed by quantitative immunostaining. Using the PKA-specific activator
N
6
-benzoyladenosine-3′,5′-cyclic monophosphate (6Bnz) and Epac-specific activator 8-(4-chlorophenylthio)-2′-
O
-methyladenosine-3′,5′-cyclic monophosphate (8CPT), we could delineate the two important downstream signals of cAMP for enhanced GJ neoformation. Whereas 6Bnz potentiated gating function of GJs with slight accumulation of Cx43 at cell–cell contacts, 8CPT remarkably enhanced the accumulation of Cx43 with a slight effect on gating. We further noticed that adherens junctions (AJs) were maturated by 8CPT, as marked by increased neural-cadherin immunostaining. Because AJ formation precedes the GJ formation, AJ formation accelerated by Epac-Rap1 signal may result in enhanced GJ formation. The involvement of Epac-Rap1 signal in GJ neoformation was further confirmed by evidence that inactivation of Rap1 by overexpression of Rap1GAP1b perturbed the accumulation of Cx43 at cell–cell contacts. Collectively, PKA and Epac cooperatively enhance functional GJ neoformation in cardiomyocytes.
Loss of Pentameric Symmetry in C-Reactive Protein Induces Interleukin-8 Secretion Through Peroxynitrite Signaling in Human Neutrophils
Authors: Khreiss Tarek , József Levente , Potempa Lawrence A. , Filep János G.
Published: August 2005

Plasma levels of C-reactive protein (CRP), nitrotyrosine, and interleukin-8 (IL-8) are known predictors of acute cardiovascular events. Peroxynitrite (ONOO
−
) may function as an intracellular signal for the production of IL-8; however, it is not known whether CRP regulates these events. Emerging evidence suggests that some bioactivities of CRP are expressed only when the pentameric structure of CRP is lost, resulting in formation of monomeric or modified CRP (mCRP). We studied the impact of human native CRP and bioengineered mCRP that cannot rearrange into the pentameric structure on ONOO
−
formation and ONOO
−
-mediated IL-8 gene expression in human leukocytes. Incubation of human whole blood or isolated neutrophils with mCRP (0.1 to 100 μg/mL) for 4 hours increased IL-8 gene expression and secretion that was blocked ≈70% by the NO synthase inhibitor
N
ω-nitro-
l
-arginine methyl ester (L-NAME). In neutrophils, mCRP simultaneously increased superoxide production and endothelial nitric oxide synthase-mediated NO formation, leading to enhanced ONOO
−
formation, and consequently activation of nuclear factor-κB and activator protein-1. Native CRP had no detectable effect at 4 hours, whereas it enhanced IL-8 release after a 24-hour incubation that was blocked by L-NAME. An anti-CD16 antibody, but not an anti-CD32 antibody, produced 60% to 70% reductions in mCRP-stimulated NO formation and IL-8 release (both
P
<0.05). These results suggest that loss of the pentameric symmetry in CRP, resulting in formation of mCRP, leads to IL-8 release from human neutrophils via peroxynitrite-mediated activation of nuclear factor-κB and activator protein-1.