Kae-Woei Liang

Berberine inhibits platelet-derived growth factor-induced growth and migration partly through an AMPK-dependent pathway in vascular smooth muscle cells

Platelet-derived growth factor (PDGF) is released from vascular smooth muscle cells (VSMCs), endothelial cells, or macrophages after percutaneous coronary intervention and is related with neointimal proliferation and restenosis. Berberine is a well-known component of the Chinese herb medicine Huanglian (Coptis chinensis), and is capable of inhibiting growth and endogenous PDGF synthesis in VSMCs after in vitro mechanical injury. We analyzed the effects of berberine on VSMC growth, migration, and signaling events after exogenous PDGF stimulation in vitro in order to mimic a post-angioplasty PDGF shedding condition. Pretreatment of VSMCs with berberine inhibited PDGF-induced proliferation. Berberine significantly suppressed PDGF-stimulated Cyclin D1/D3 and Cyclin-dependent kinase (Cdk) gene expression. Moreover, berberine increased the activity of AMP-activated protein kinase (AMPK), which led to phosphorylation activation of p53 and increased protein levels of the Cdk inhibitor p21(Cip1). Compound C, an AMPK inhibitor, partly but significantly attenuated berberine-elicited growth inhibition. In addition, stimulation of VSMCs with PDGF led to a transient increase in GTP-bound, active form of Ras, Cdc42 and Rac1, as well as VSMC migration. However, pretreatment with berberine significantly inhibited PDGF-induced Ras, Cdc42 and Rac1 activation and cell migration. Co-treatment with farnesyl pyrophosphate and geranylgeranyl pyrophosphate drastically reversed berberine-mediated anti-proliferative and migratory effects in VSMCs. Based on these findings, we conclude that berberine inhibited PDGF-induced VSMC growth via activation of AMPK/p53/p21(Cip1) signaling while inactivating Ras/Rac1/Cyclin D/Cdks and suppressing PDGF-stimulated migration via inhibition of Rac1 and Cdc42. These observations offer a molecular explanation for the anti-proliferative and anti-migratory properties of berberine.

Decreased ratio of high-molecular-weight to total adiponectin is associated with angiographic coronary atherosclerosis severity but not restenosis.

BACKGROUND Adiponectin is thought to protect against atherosclerosis and its expression is decreased in metabolic syndrome and diabetes mellitus. Adiponectin has a high-molecular-weight (HMW) multimer structure in the blood. We determined whether circulating HMW adiponectin, total adiponectin, or their ratio predicts baseline angiographic coronary artery disease (CAD) severity and restenosis after percutaneous coronary intervention (PCI). METHODS Patients with stable angina pectoris who underwent PCI for a de novo lesion and had angiographic follow-up at our hospital were retrospectively enrolled. The study patients were grouped as moderate (N=68) or severe (N=63) coronary atherosclerosis by the baseline median Gensini severity score (moderate<22, severe> or =22). RESULTS Univariate analysis showed that subjects in the severe CAD group had a lower HMW/total adiponectin ratio (0.32+/-0.19 vs. 0.37+/-0.16, p=0.024) while the absolute value of HMW adiponectin (2.17+/-2.05 vs. 2.27+/-2.07 microg/ml, p=0.389) and total adiponectin (5.97+/-3.12 vs. 5.76+/-2.91 microg/ml, p=0.807) were similar between the severe and moderate CAD groups. In a multivariate binary logistic regression model, a higher serum HMW/total adiponectin ratio (odds ratio 0.058, p=0.018) was negatively, while hypercholesterolemia (OR 2.475, p=0.029) was positively associated with coronary atherosclerosis disease severity. In terms of restenosis after PCI (mean follow-up at 12+/-13 months), HMW adiponectin, total adiponectin and their ratio were similar between restenotic (N=91) and non-restenotic groups (N=40). CONCLUSIONS A decreased ratio of circulating HMW adiponectin to total adiponectin is associated with angiographic disease severity but not restenosis in CAD patients undergoing PCI.

MRI Measured Epicardial Adipose Tissue Thickness at the Right AV Groove Differentiates Inflammatory Status in Obese Men With Metabolic Syndrome

Epicardial adipose tissue (EAT) is a metabolically active visceral fat, which secretes inflammatory cytokines and adipokines. In this study, our aim was to examine which measurements of EAT thickness by magnetic resonance imaging (MRI) could best help differentiate inflammatory status, classified by levels of high‐sensitivity C‐reactive protein (hs‐CRP), in obese men with metabolic syndrome (MetS). We prospectively enrolled 32 men with central obesity (waist circumference ≥90 cm) and at least two other MetS criteria. MRI examinations for measurements of EAT, subcutaneous fat, and abdominal visceral fat as well as recordings of anthropometric parameters and tests for serum inflammatory cytokines and adipokines were conducted. Subjects with MetS (N = 32) were divided into three subgroups: (i) low inflammatory status (hs‐CRP < 0.3 mg/dl, N = 8), (ii) intermediate inflammatory status (hs‐CRP 0.1–0.3 mg/dl, N = 15), and (iii) high inflammatory status (hs‐CRP >0.3 mg/dl, N = 9). EAT thickness at the right atrioventricular (AV) groove showed a significant linear trend among the three subgroups of MetS (P for trend = 0.004). High inflammatory status MetS subgroup had a significantly thicker right AV groove EAT than did the low inflammatory status MetS subgroup (19.3 ± 3.1 vs. 14.4 ± 3.3 mm, P = 0.015). In binary logistic regression analysis, right AV groove EAT thickness was an independent predictor for differentiating inflammatory status in MetS while abdominal visceral fat area and insulin‐resistance index were not. In conclusion, MRI measured EAT thickness at the right AV groove could be a useful marker for differentiating the inflammatory status in obese men with MetS.

Role of JNK and c-Jun signaling pathway in regulation of human serum paraoxonase 1 gene transcription by berberine in human HepG2 cells.

Human serum paraoxonase 1 (PON1), an arylesterase, is associated with high-density lipoprotein (HDL) and can inhibit the oxidative modification of low-density lipoprotein (LDL), implying that PON1 may prevent atherosclerosis. Berberine, a botanical alkaloid, lowers the cholesterol level in serum and is thought to display cardioprotective properties. However, the effect of berberine on PON1 gene expression remains unclear. Thus, we evaluated how berberine regulates PON1 gene expression. In human hepatoma HepG2 and Huh7 cells, the PON1 protein levels were increased by berberine in a dose- and time-dependent manner. Data from real time PCR analysis indicated that berberine could up-regulate PON1 expression at the transcriptional level. Additionally, treating HepG2 cells with berberine increased the levels of phosphorylated JNK and its downstream target c-Jun. The PON1 upstream region contained a consensus binding site for AP1, and the electrophoretic mobility shift assay and chromatin immunoprecipitation analysis indicated that the AP1 factors, especially c-Jun, bind to the upstream sequence of the PON1 promoter upon berberine treatment. Moreover, pretreatment with SP600125 (JNK inhibitor) or curcumin (AP-1 inhibitor) markedly attenuated the berberine-induced PON1 promoter activity and protein expression. This is the first study to suggest that JNK/c-Jun signalling pathway plays a crucial role in berberine-regulated PON1 transcription in human hepatoma cells. The induction of PON1 by berberine elucidates a potential mechanism through which berberine may protect against atherosclerosis.

Leptin to adiponectin ratio as a useful predictor for cardiac syndrome X.

Objective: The role of adipokines in the development of cardiac syndrome X (CSX) remains unknown. Methods: Fifty-nine CSX subjects were retrospectively enrolled from our catheterization databank. Another 54 subjects with valvular heart disease or arrhythmia served as controls. Adipokines were measured by ELISA tests. Results: The CSX had lower circulating adiponectin but higher leptin and higher leptin/adiponectin ratio (×1000) (3.78 ± 4.96 vs. 2.14 ± 5.67, p < 0.001) than those of the controls. In a multivariate analysis, a higher leptin/adiponectin ratio was a predictor of CSX, while insulin-resistance index was not. Conclusions: Adipokines may be implicated in the pathogenesis of CSX.

Persistent elevation of paraoxonase-1 specific enzyme activity after weight reduction in obese non-diabetic men with metabolic syndrome

BACKGROUND Paraoxonase-1 (PON1) is an esterase associated with the high-density lipoprotein (HDL) in serum. To date, there have been few reports about circulating PON1 protein concentration and specific activity in subjects with metabolic syndrome (MetS). More importantly, it is unknown whether weight loss could alter PON1 protein expression or specific activity in obese non-diabetic men with MetS. METHODS We prospectively enrolled a total of 40 obese non-diabetic men with MetS. Among them, 22 subjects finished the 3-month course of weight loss program and complied for longer follow-ups post-weight loss at the 3rd, 12th, and 18th month from the beginning of the program. Twenty-six healthy volunteers served as controls. Serum circulating PON1 concentration was measured by an enzyme linked immunosorbent kit (ELISA) and PON1 activity was measured by an automated PON1 activity assay. RESULTS Obese non-diabetic men with MetS (n=40) had a higher PON1 protein concentration (31.0 ± 11.3 vs. 24.8 ± 9.7 μg/ml, p=0.025) but lower specific enzyme activity (7.5 ± 4.0 vs. 11.2 ± 7.2 mU/μg, p=0.023) than those of the controls. Multivariate regression analysis of baseline PON1 specific activity revealed that adiponectin was a significant positive predictor (p=0.044) while monocyte chemotactic protein-1 (MCP-1) was a negative predictor (p=0.031). After a 3-month weight loss program, obese MetS men (n=22) had a significant weight reduction (95.8 ± 9.0 to 86.3 ± 10.4 kg, with a 9.9 ± 5.4% decrease, p<0.001). PON1 protein decreased significantly after weight loss and kept declining through the 3rd month till the 18th month follow-up. PON1 specific enzyme activity (baseline 7.5 ± 2.6 mU/μg) increased significantly after weight loss and kept increasing through the 12th month till the 18th month follow-ups (11.8 ± 6.4 mU/μg, p=0.001 vs. baseline). CONCLUSIONS Weight loss by a 3-month diet and exercise program time-sequentially increased PON1 specific enzyme activity in obese non-diabetic men with MetS.

The use and clinical outcomes of rotablation in challenging cases in the drug-eluting stent era

Background: Rotational atherectomy (RA) has been advocated in the bare metal stent (BMS) era but is underused now due to technique demands and nonsuperior outcomes. The aim of this study was to evaluate the procedural and clinical outcomes of patients with very complex, severely calcified coronary lesions treated by RA and drug‐eluting stents (DESs) in our current percutaneous coronary intervention (PCI) practice in a region where RA use has been limited by lack of insurance reimbursement. Methods: From March 2004 to November 2010, all consecutive patients who required RA treatment for severely calcified de novo lesions of native coronary arteries followed by DES implantation were queried from the cath lab database and recruited. Their clinical and angiographic characteristics at the index PCI were analyzed and completed by a thorough review of the medical charts. Results: A total of 67 consecutive patients with 71 very complex, heavily calcified coronary lesions treated with RA plus DES were recruited. Of these patients, 64% presented with acute coronary syndrome, 9.0% with cardiogenic shock, 43.3% with chronic renal failure, and 50.7% with diabetes. Multiple‐vessel diseases were found in 92.5% of our patients, and the average coronary artery calcification (CAC) score was 3.6 ± 1.4. Of the coronary lesions, 26.7% were either balloon‐uncrossable or balloon‐undilatable. The angiographic success rate was 100% with one non‐Q myocardial infarction. Five patients (7.5%) died in hospital, all initially presenting with extensive myocardial infarction and/or cardiogenic shock. The out‐of‐hospital major adverse cardiac event was 17.9% at the mean follow‐up of 23.2 months (range: 5–86), primarily due to high target‐lesion revascularization and target‐vessel revascularization rates of 10.4% and 10.4%, respectively. Only one (1.5%) probable subacute stent thrombosis was observed in the follow‐up. Conclusion: RA with DES implantation in very complex, heavily calcified coronary lesions can achieve very low complication and low out‐of‐hospital major adverse cardiac event rates even in high‐risk patients despite use limited by lack of insurance reimbursement. The study results convince us to sustain and even broaden the use of this novel, but underused, device in the DES era.

Comprehensive MDCT Evaluation of Patients With Pulmonary Hypertension: Diagnosing Underlying Causes With the Updated Dana Point 2008 Classification

OBJECTIVE Pulmonary hypertension is a challenge for imagers and clinicians, with a variety of possible underlying causes, each with its own specific treatment. Although the diagnosis is based on physiologic measurements, ECG-gated MDCT can play a vital role in elucidating underlying cardiac, vascular, and pulmonary causes. CONCLUSION A revised system for pulmonary hypertension, the Dana Point classification, can provide a template for review of the myriad causes of this complex condition.

Brain-derived neurotrophic factor not associated with metabolic syndrome but inversely correlated with vascular cell adhesion molecule-1 in men without diabetes.

BACKGROUND Excessive visceral fat with unbalanced adipokines is a critical pathogenic factor of metabolic syndrome (MetS), which is associated with disorders of the central nervous system and cardiovascular disease. Because brain-derived neurotrophic factor (BDNF) plays an important role in neurons, we examined the relationship of BDNF to MetS, adipose tissue and biomarkers in men. METHODS Thirty-four non-diabetic men with MetS and another 24 age-matched men without MetS were enrolled. In addition to fasting blood samples, the area of adipose tissue at the waist was assessed by magnetic resonance imaging (MRI). RESULTS There was no significant difference in serum BDNF concentrations between men with or without MetS (40.9±8.0 vs. 43.2±6.1 ng/ml, P=0.235). However, the serum concentration of soluble vascular cell adhesion molecule-1 (VCAM-1) was higher in the subjects with a lower BDNF level (737±230 vs. 628±115 ng/ml, P=0.025). An inverse correlation between VCAM-1 and BDNF was observed (r=-0.391, P=0.002). After adjusting for visceral adipose tissue, VCAM-1 was found to be independently associated with BDNF [95% confidence interval (-0.025, -0.005), P=0.004]. CONCLUSION These data show no difference in serum BDNF levels between the men with MetS and controls. However, serum BDNF was inversely correlated with serum VCAM-1 in men without diabetes.

Transcatheter Therapy of Lutembacher Syndrome

Lutembacher syndrome is a combination of congenital atrial septal defect (ASD) and acquired mitral stenosis (MS). The combination of these 2 diseases has hemodynamic influences on each other and the degree of MS may be underestimated. Traditionally, Lutembacher syndrome is corrected by surgical treatment. Nowadays, these 2 diseases are amenable to transcatheter treatment without the need for surgery. Here, we describe a 28-year-old female with Lutembacher syndrome who benefited from combined transcatheter therapy of balloon valvuloplasty for MS and device closure for ASD with an Amplatzer septal occluder.