Yih-Jer Wu

Increase of Vitamin E Content in LDL and Reduction of Atherosclerosis in Cholesterol-Fed Rabbits by a Water-Soluble Antioxidant-Rich Fraction of Salvia miltiorrhiza

Antioxidants that prevent LDL from oxidation may reduce atherosclerosis. Salvia miltiorrhiza Bunge is a Chinese herb widely used for the treatment of atherosclerosis-related disorders. Salvianolic acid B (Sal B), a water-soluble polyphenolic antioxidant isolated from the roots of this plant, was found to scavenge 1,1-diphenyl-2-picrylhydrazyl radicals and inhibit LDL oxidation more effectively than probucol. In order to evaluate the antiatherogenic potential, New Zealand White rabbits were fed for 12 weeks a normal diet, a high cholesterol diet, a high cholesterol diet containing 1% probucol, or a high cholesterol diet containing a 5% water-soluble extract of S miltiorrhiza (SM). Both SM and probucol feeding reduced plasma cholesterol. LDLs from the SM-treated group were more resistant to Cu2+-induced oxidation and contained more vitamin E (21.7+/-2.1 mmol/micromol LDL cholesterol) than did LDLs from the high cholesterol diet group (9.6+/-1.8 nmnol/micromol LDL cholesterol) (P<.005). Endothelial damage, determined at week 6, was reduced by 53% in the SM group (P<.01). SM treatment reduced the atherosclerotic area in the abdominal aorta by 56% (P<.005) and cholesterol deposition in the thoracic aorta by 50% (P<.005). The severity of atherosclerosis in the SM group was significantly reduced after adjustment by using cholesterol exposure as an index of the cholesterol-lowering effect. This study concludes that the reduction of atherosclerosis by SM relies not only on its cholesterol-lowering effect but more heavily on its antioxidant potential to prevent endothelial damage and inhibit LDL oxidative modification in hypercholesterolemic animals.

Reduced expression of endothelial connexin37 and connexin40 in hyperlipidemic mice: recovery of connexin37 after 7-day simvastatin treatment.

Objective—We sought to clarify the response of endothelial connexins to hyperlipidemia and lipid-lowering therapy. Methods and Results—Aortic endothelial gap junctions were analyzed by en face immunoconfocal microscopy and electron microscopy in C57BL/6 mice subjected to the following regimens: (1) normal chow (NC) for 3 months (3 mo), (2) NC for 9 mo, (3) NC for 3 mo, followed by a cholesterol-enriched diet (CED) for 6 mo, (4) NC for 3 mo and CED for 6 mo, with simvastatin in the final week, and (5) (in apoprotein E [apoE]-deficient mice) NC and examined at 3 mo and 7 to 9 mo. In wild-type mice, connexin37 (Cx37) and Cx40 were markedly downregulated in the CED-fed animals compared with those fed NC (CED vs 9-mo NC, 77% reduction in Cx37 and 65% reduction in Cx40; both P <0.01). After simvastatin treatment, Cx40 remained depressed, but Cx37 recovered to 94% of the level found in non–cholesterol-fed animals (P <0.01). Electron microscopy demonstrated that gap junctions were smaller in animals fed the CED compared with those given simvastatin and with controls fed NC (P <0.01). Endothelial connexins were rare in the atherosclerotic plaques of apoE-deficient mice. Conclusions—Mouse aortic endothelial gap junctions and connexins are downregulated during long-term hyperlipidemia. Short-term treatment with simvastatin leads to recovery of Cx37 expression but not Cx40 expression.

Pericardial and thoracic peri-aortic adipose tissues contribute to systemic inflammation and calcified coronary atherosclerosis independent of body fat composition, anthropometric measures and traditional cardiovascular risks

BACKGROUND Coronary atherosclerosis has traditionally been proposed to be associated with several cardiovascular risk factors and anthropometric measures. However, clinical data regarding the independent value of visceral adipose tissue in addition to such traditional predictors remains obscure. MATERIALS AND METHODS We subsequently studied 719 subjects (age: 48.1±8.3 years, 25% females) who underwent multidetector computed tomography (MDCT) for coronary calcium score (CCS) quantification. Baseline demographic data and anthropometric measures were taken with simultaneous body fat composition estimated. Visceral adipose tissue of pericardial and thoracic peri-aortic fat was quantified by MDCT using TeraRecon Aquarius workstation (San Mateo, CA). Traditional cardiovascular risk stratification was calculated by metabolic (NCEP ATP III) and Framingham (FRS) scores and high-sensitivity CRP (Hs-CRP) was taken to represent systemic inflammation. The independent value of visceral adipose tissue to systemic inflammation and CCS was assessed by utilizing multivariable regression analysis. RESULTS Of all subjects enrolled in this study, the mean values for pericardial and peri-aortic adipose tissue were 74.23±27.51 and 7.23±3.69ml, respectively. Higher visceral fat quartile groups were associated with graded increase of risks for cardiovascular diseases. Both adipose burdens strongly correlated with anthropometric measures including waist circumference, body weight and body mass index (all p<0.001). In addition, both visceral amount correlates well with ATP and FRS scores, all lipid profiles and systemic inflammation marker in terms of Hs-CRP (all p<0.001). After adjustment for baseline variables, both visceral fat were independently related to Hs-CRP levels (all p<0.05), but only pericardial fat exerted independent role in coronary calcium deposit. CONCLUSION Both visceral adipose tissues strongly correlated with systemic inflammation beyond traditional cardiovascular risks and anthropometric measures, though only pericardial fat exerted independent role in coronary calcium deposit. Our data suggested that visceral adipose tissue may thus contribute to systemic inflammation and play an independent role in the pathogenesis of atherosclerosis.

Epicardial adipose tissue relating to anthropometrics, metabolic derangements and fatty liver disease independently contributes to serum high-sensitivity C-reactive protein beyond body fat composition: a study validated with computed tomography.

BACKGROUND Epicardial adipose tissue (EAT) measured by echocardiography has been proposed to be associated with metabolic syndrome and increased cardiovascular risks. However, its independent association with fatty liver disease and systemic inflammation beyond clinical variables and body fat remains less well known. METHODS The relationships between EAT and various factors of metabolic derangement were retrospectively examined in consecutive 359 asymptomatic subjects (mean age, 51.6 years; 31% women) who participated in a cardiovascular health survey. Echocardiography-derived regional EAT thickness from parasternal long-axis and short-axis views was quantified. A subset of data from 178 randomly chosen participants were validated using 16-slice multidetector computed tomography. Body fat composition was evaluated using bioelectrical impedance from foot-to-foot measurements. RESULTS Increased EAT was associated with increased waist circumference, body weight, and body mass index (all P values for trend = .005). Graded increases in serum fasting glucose, insulin resistance, and alanine transaminase levels were observed across higher EAT tertiles as well as a graded decrease of high-density lipoprotein (all P values for trend <.05). The areas under the receiver operating characteristic curves for identifying metabolic syndrome and fatty liver disease were 0.8 and 0.77, with odds ratio estimated at 3.65 and 2.63, respectively. In a multivariate model, EAT remained independently associated with higher high-sensitivity C-reactive protein and fatty liver disease. CONCLUSIONS These data suggested that echocardiography-based epicardial fat measurement can be clinically feasible and was related to several metabolic abnormalities and independently associated fatty liver disease. In addition, EAT amount may contribute to systemic inflammation beyond traditional cardiovascular risks and body fat composition.

Reduction of connexin43 in human endothelial progenitor cells impairs the angiogenic potential

Our previous work showed that arsenic trioxide down-regulated Cx43 and attenuated the angiogenic potential of human late endothelial progenitor cells (EPC). However, the relation between Cx43 and angiogenic activity of the EPC remained unclear. In the study, human late EPC were treated with siRNA specific to Cx43 (Cx43siRNA). The expression profiles as well as activity of the treated cells were examined. In parallel, the angiogenic potential of human EPC treated with Cx43siRNA was evaluated using murine hind limb ischemic model. The results showed that, in the EPC treated with Cx43siRNA, the activity of migration, proliferation, and angiogenic potential were attenuated, accompanied by reduction in vascular endothelial growth factor (VEGF) expression. In hind limb ischemia mice, EPC treated with Cx43siRNA lost the therapeutic angiogenic potential. VEGF supplementation partially recovered the activity impaired by Cx43 down-regulation. In conclusion, reduced Cx43 expression per se in the EPC causes decreased expression of VEGF and impaired angiogenic potential of the cells. Prevention of Cx43 reduction is a potential target to maintain the angiogenic potential of the EPC.

Diabetes Reduces Aortic Endothelial Gap Junctions in ApoE-deficient Mice: Simvastatin Exacerbates the Reduction

We examined the endothelial gap junctions in diabetic hyperlipidemic mice. Male apolipoprotein E (apoE)-deficient mice were made diabetic by streptozotocin. Three weeks later, the animals were treated with simvastatin for 2 weeks. The expression of aortic gap junctions in the non-diabetic (n=10), untreated diabetic (n=10), and simvastatin-treated diabetic animals (n=6) was analyzed. There was a >4-fold increase in serum cholesterol level and >50% increase in plaque areas in the diabetic mice, regardless of simvastatin treatment. Western blotting of aortae showed reduced expression of connexin37 (Cx37) and Cx40 in the diabetic mice, which were further decreased in the simvastatin-treated diabetic mice. Immunoconfocal microscopy showed that endothelial gap junctions made of Cx37 and Cx40 were both reduced in the untreated diabetic mice compared with the non-diabetic mice (decrease: Cx37, 41%; Cx40, 42%; both p<0.01). The reduction was greater in the simvastatin-treated mice (decrease in treated diabetic vs non-diabetic: Cx37, 61%; Cx40, 79%; both p<0.01; decrease in treated diabetic vs untreated diabetic: Cx37, 34%; Cx40, 63%; both p<0.01). Cx37 and Cx40 were decreased in the endothelium of plaque surface. Cx43 appeared in the medial layer and inner layer of the intima. All three connexins were rarely expressed in monocytes/macrophages inside the plaques. In conclusion, in apoE-deficient mice, streptozotocin-induced diabetes is associated with downregulation of endothelial Cx37 and Cx40 gap junctions. Short-term treatment with simvastatin exacerbates the downregulation.

Nonviral gene therapy targeting cardiovascular system.

The goal of gene therapy is either to introduce a therapeutic gene into or replace a defective gene in an individuals cells and tissues. Gene therapy has been urged as a potential method to induce therapeutic angiogenesis in ischemic myocardium and peripheral tissues after extensive investigation in recent preclinical and clinical studies. A successful gene therapy mainly relies on the development of the gene delivery vector. Developments in viral and nonviral vector technology including cell-based gene transfer will further improve transgene delivery and expression efficiency. Nonviral approaches as alternative gene delivery vehicles to viral vectors have received significant attention. Recently, a simple and safe approach of gene delivery into target cells using naked DNA has been improved by combining several techniques. Among the physical approaches, ultrasonic microbubble gene delivery, with its high safety profile, low costs, and repeatable applicability, can increase the permeability of cell membrane to macromolecules such as plasmid DNA by its bioeffects and can provide as a feasible tool in gene delivery. On the other hand, among the promising areas for gene therapy in acquired diseases, ischemic cardiovascular diseases have been widely studied. As a result, gene therapy using advanced technology may play an important role in this regard. The aims of this review focus on understanding the cellular and in vivo barriers in gene transfer and provide an overview of currently used chemical vectors and physical tools that are applied in nonviral cardiovascular gene transfer.

Sequential endovascular coil embolization for a traumatic cervical vertebral AV fistula

An arteriovenous (AV) fistula involving the cervical vertebral artery is rare. Iatrogenic injury from percutaneous puncture and penetrating wounds are the most common causes. Symptoms include tinnitus and the presence of a pulsatile mass with a thrill. Conservative treatment with coil embolization and preservation of the vertebral artery is an alternative to surgical intervention. We report a patient who developed an AV fistula involving the vertebral artery and internal jugular vein following surgical repair of a stab wound to the neck. The sequential endovascular coil embolism was performed with subsequent successful occlusion of fistula. No neurological deficit developed during or after intervention. This approach appears to be a safe method in the treatment of vertebral AV fistula.Catheter Cardiovasc Interv 2003;60:267–269. ©2003 Wiley‐Liss, Inc.

Relation of Carotid Artery Diameter With Cardiac Geometry and Mechanics in Heart Failure With Preserved Ejection Fraction

Background Central artery dilation and remodeling are associated with higher heart failure and cardiovascular risks. However, data regarding carotid artery diameter from hypertension to heart failure have remained elusive. We sought to investigate this issue by examining the association between carotid artery diameter and surrogates of ventricular dysfunction. Methods and Results Two hundred thirteen consecutive patients including 49 with heart failure and preserved ejection fraction (HFpEF), 116 with hypertension, and an additional 48 healthy participants underwent comprehensive echocardiography and tissue Doppler imaging. Ultrasonography of the common carotid arteries was performed for measurement of intima‐media thickness and diameter (CCAD). Cardiac mechanics, including LV twist, were assessed by novel speckle‐tracking software. A substantial graded enlargement of CCAD was observed across all 3 groups (6.8±0.6, 7.7±0.73, and 8.7±0.95 mm for normal, hypertension, and HFpEF groups, respectively; ANOVA P<0.001) and correlated with serum brain natriuretic peptide level (R2=0.31, P<0.001). Multivariable models showed that CCAD was associated with increased LV mass, LV mass‐to‐volume ratio (β‐coefficient=10.9 and 0.11, both P<0.001), reduced LV longitudinal and radial strain (β‐coeffficient=0.81 and −3.1, both P<0.05), and twist (β‐coefficient=−0.84, P<0.05). CCAD set at 8.07 mm as a cut‐off had a 77.6% sensitivity, 82.3% specificity, and area under the receiver operating characteristic curves (AUROC) of 0.86 (95% CI 0.80 to 0.92) in discriminating HFpEF. In addition, CCAD superimposed on myocardial deformation significantly expanded AUROC (for longitudinal strain, from 0.84 to 0.90, P of ΔAUROC=0.02) in heart failure discrimination models. Conclusions Increased carotid artery diameter is associated with worse LV geometry, higher brain natriuretic peptide level, and reduced contractile mechanics in individuals with HFpEF.

The normal limits, subclinical significance, related metabolic derangements and distinct biological effects of body site-specific adiposity in relatively healthy population.

Background The accumulation of visceral adipose tissue that occurs with normal aging is associated with increased cardiovascular risks. However, the clinical significance, biological effects, and related cardiometabolic derangements of body-site specific adiposity in a relatively healthy population have not been well characterized. Materials and Methods In this cross-sectional study, we consecutively enrolled 608 asymptomatic subjects (mean age: 47.3 years, 27% female) from 2050 subjects undergoing an annual health survey in Taiwan. We measured pericardial (PCF) and thoracic peri-aortic (TAT) adipose tissue volumes by 16-slice multi-detector computed tomography (MDCT) (Aquarius 3D Workstation, TeraRecon, San Mateo, CA, USA) and related these to clinical characteristics, body fat composition (Tanita 305 Corporation, Tokyo, Japan), coronary calcium score (CCS), serum insulin, high-sensitivity C-reactive protein (Hs-CRP) level and circulating leukocytes count. Metabolic risk was scored by Adult Treatment Panel III guidelines. Results TAT, PCF, and total body fat composition all increased with aging and higher metabolic scores (all p<0.05). Only TAT, however, was associated with higher circulating leukocyte counts (ß-coef.:0.24, p<0.05), serum insulin (ß-coef.:0.17, p<0.05) and high sensitivity C-reactive protein (ß-coef.:0.24, p<0.05). These relationships persisted after adjustment in multivariable models (all p<0.05). A TAT volume of 8.29 ml yielded the largest area under the receiver operating characteristic curve (AUROC: 0.79, 95%CI: 0.74–0.83) to identify metabolic syndrome. TAT but not PCF correlated with higher coronary calcium score after adjustment for clinical variables (all p<0.05). Conclusion In our study, we observe that age-related body-site specific accumulation of adipose tissue may have distinct biological effects. Compared to other adiposity measures, peri-aortic adiposity is more tightly associated with cardiometabolic risk profiles and subclinical atherosclerosis in a relatively healthy population.