Shin Yi Jang

Vascular endothelial growth factor-induced angiogenic gene therapy in patients with peripheral artery disease

This phase 1 clinical trial tested the safety of intramuscular gene transfer by using naked plasmid DNA encoding the gene for VEGF, and analyzed the potential therapeutic benefits in patients with severe peripheral arterial disease (PAD). This study was an open-labeled, dose- escalating, single-center trial on nine male patients with severe debilitating PAD who had not responded to conventional therapy. Seven had Buergers disease and two had arteriosclerosis obliterans. Plasmid DNA (pCK) containing human VEGF165 was given by eight intramuscular injections in and around the area in need of new blood vessels. The study evaluated three escalating total doses (2, 4, and 8 mg of pCK- VEGF165), with half of each total dose given four weeks apart. The follow-up duration was nine months. The gene injections were well tolerated without significant side effects or laboratory abnormalities related to gene transfer. Three patients showed transient edema in their extremities. Ischemic pain of the affected limb was relieved or improved markedly in six of seven patients. Ischemic ulcers healed or improved in four of six patients. The mean ankle-brachial index (ABI) improved significantly. Six of nine patients showed an increase in collateral vessels around the injection sites demonstrated by digital subtraction angiography. However, there was no relationship between the degree of ABI improvement and the dose given. Mean plasma levels of VEGF did not increase significantly. In conclusion, intramuscular injections of pCK- VEGF165 can be performed safely to induce therapeutic angiogenesis in patients with severe PAD.

Mutations in DDX58, which Encodes RIG-I, Cause Atypical Singleton-Merten Syndrome

Singleton-Merten syndrome (SMS) is an autosomal-dominant multi-system disorder characterized by dental dysplasia, aortic calcification, skeletal abnormalities, glaucoma, psoriasis, and other conditions. Despite an apparent autosomal-dominant pattern of inheritance, the genetic background of SMS and information about its phenotypic heterogeneity remain unknown. Recently, we found a family affected by glaucoma, aortic calcification, and skeletal abnormalities. Unlike subjects with classic SMS, affected individuals showed normal dentition, suggesting atypical SMS. To identify genetic causes of the disease, we performed exome sequencing in this family and identified a variant (c.1118A>C [p.Glu373Ala]) of DDX58, whose protein product is also known as RIG-I. Further analysis of DDX58 in 100 individuals with congenital glaucoma identified another variant (c.803G>T [p.Cys268Phe]) in a family who harbored neither dental anomalies nor aortic calcification but who suffered from glaucoma and skeletal abnormalities. Cys268 and Glu373 residues of DDX58 belong to ATP-binding motifs I and II, respectively, and these residues are predicted to be located closer to the ADP and RNA molecules than other nonpathogenic missense variants by protein structure analysis. Functional assays revealed that DDX58 alterations confer constitutive activation and thus lead to increased interferon (IFN) activity and IFN-stimulated gene expression. In addition, when we transduced primary human trabecular meshwork cells with c.803G>T (p.Cys268Phe) and c.1118A>C (p.Glu373Ala) mutants, cytopathic effects and a significant decrease in cell number were observed. Taken together, our results demonstrate that DDX58 mutations cause atypical SMS manifesting with variable expression of glaucoma, aortic calcification, and skeletal abnormalities without dental anomalies.

Cardiovascular manifestations of Takayasu arteritis and their relationship to the disease activity: analysis of 204 Korean patients at a single center.

Takayasus arteritis (TA) is primary vasculitis. Cardiac involvements in TA is due to the consequences of the vascular lesions as well as the primary pathology of the heart. The disease activity of TA is known to influence the prognosis of TA. We hypothesized that the cardiovascular involvement of TA is related to the disease activity. We evaluated the cardiovascular manifestations of TA, and we assessed their relation to the disease activity of TA. Two hundred four patients were diagnosed with TA from September, 1994 to March, 2009 according to the diagnostic criteria of the 1990 American College of Rheumatology. Their clinical features and the laboratory, angiographic and echocardiographic findings were retrospectively reviewed. The group with active disease activity was defined as satisfying one of the following criteria: i) an elevated ESR or CRP level, ii) thickened arterial wall with mural enhancement on CT or MR angiography, and iii) carotidynia at the time of the initial diagnosis. One hundred thirty nine patients (69.2%) were classified as the active group. The cardiovascular signs and symptoms were not generally different between the active and inactive groups. The active TA patients had more frequent involvement of the ascending aorta and the aortic arch and its main branches than did the inactive group. The active group showed a higher incidence of significant aortic valve regurgitation and pulmonary hypertension, and a higher level of NT-proBNP. These findings suggest that disease activity plays an important role for the cardiovascular manifestations of TA. The TA patients with higher activity have more cardiovascular morbidity compared to the TA patients with low disease activity.

A comparison of the Ghent and revised Ghent nosologies for the diagnosis of Marfan syndrome in an adult Korean population.

Recently, a revised Ghent nosology has been established for the diagnosis of Marfan syndrome (MFS) that puts more weight on the aortic root aneurysm and ectopia lentis. We compared the application of the Ghent and revised Ghent nosologies in adult Korean patients for whom there is suspicion of MFS. From January 1995 to June 2010, we enrolled 106 patients older than 20 years for whom there was suspicion of MFS, and who had undergone genetic analysis of the fibrillin‐1 gene (FBN1). Of 106 patients, 86 patients (81%) fulfilled the criteria of the Ghent nosology, and 84 patients (79%) met the criteria of the revised Ghent nosology. The two patients who met the Ghent nosology criteria, but not the criteria of the revised Ghent nosology were diagnosed with Loeys–Dietz syndrome and MASS phenotype. The level of agreement between both nosologies was very high (κ = 0.94, 95% confidence interval: 0.86 to 1.0). Marfan‐like syndromes were diagnosed in 30% (6/20 patients) with negative Ghent and revised Ghent criteria and no FBN1 mutations. These results suggest that adult Korean patients who fulfill the old Ghent criteria almost all fulfill the new criteria for the diagnosis of MFS.

Early growth response factor-1 is associated with intraluminal thrombus formation in human abdominal aortic aneurysm.

OBJECTIVES The goal of this study was to investigate the expression of early growth response-1 (Egr-1), a vascular pathogenic transcription factor, and its potential relationship with tissue factor (TF), a key player during the thrombus formation in the abdominal aortic aneurysm (AAA) wall. BACKGROUND Although intraluminal thrombus is a common finding in human AAA, the molecular mechanism of the thrombus formation has not been studied. METHODS During the elective AAA repair, specimens were taken from the thrombus-covered and thrombus-free portions of the aneurysmal wall in each of 16 patients with AAA and analyzed to assess the differential expression of Egr-1 and TF. The proinflammatory and prothrombogenic activities of Egr-1 in vasculature were evaluated in vitro and in vivo by overexpressing it using adenovirus. RESULTS The expression of both Egr-1 and TF was significantly increased in the thrombus-covered wall compared with the thrombus-free wall, in which their up-regulation in the thrombus-covered wall was strongly correlated with each other (p < 0.005, r = 0.717). Adenoviral overexpression of Egr-1 in human vascular smooth muscle and endothelial cells was found to up-regulate the expression of TF and inflammation-related genes. Moreover, Egr-1 overexpression in endothelial cells increased their adhesiveness to monocytes and also substantially promoted the intravascular thrombus formation in vivo, as shown in the inferior vena cava ligation experiment of the rat. CONCLUSIONS The present study demonstrates the differential up-regulation of Egr-1 in the thrombus-covered wall of human AAA and also suggests its possible contribution to the thrombogenic and inflammatory pathogenesis in human AAA.

Cardioprotective effects of rhamnetin in H9c2 cardiomyoblast cells under H2O2-induced apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE Many studies have emphasized that flavonoids, found in various fruits, vegetables, and seeds, as well as tea and red wine, have potential health-promoting and disease-preventing effects. Rhamnetin is a flavonoid that exhibits antioxidant capabilities. However, little is known about its effect on cardiac myocytes under oxidative stress and the underlying mechanisms. MATERIALS AND METHODS H9c2 cardiomyoblast cells were subjected to H2O2, to study the protective effect of rhamnetin on cell viability, apoptosis, and ROS production. Signaling proteins related to apoptosis, survival, and redox were analyzed by Western blot. Furthermore, the mRNA expressions of SIRTs were tested by real time-polymerase chain reaction (PCR). RESULTS We investigated the protective effects of rhamnetin against H₂O₂-induced apoptosis in H9c2 cardiomyoblasts. Rhamnetin protected cells against H₂O₂-induced cell death without any cytotoxicity, as determined by the XTT assay, LDH assay, TUNEL assay, Hoechst 33342 assay, and Western blot analysis of apoptosis-related proteins. Rhamnetin also enhanced the expression of catalase and Mn-SOD, thereby inhibiting production of intracellular ROS. Furthermore, rhamnetin recovered the H₂O₂-induced decrease in phosphorylation of Akt/GSK-3β and MAPKs (ERK1/2, p38 MAPK, and JNK) and pretreatment with their inhibitors, attenuating the rhamnetin-induced cytoprotective effect. Further studies with real time-PCR and a sirtuin inhibitor showed that cardioprotection by rhamnetin occurred through induction of SIRT3 and SIRT4. CONCLUSIONS Taken together, these results suggest that rhamnetin may have novel therapeutic potential to protect the heart from ischemia-related injury.

Fragmented QRS complex in adult patients with Ebstein anomaly and its association with arrhythmic risk and the severity of the anomaly.

Background—Fragmented QRS complex (fQRS) on 12-lead ECG, a marker of myocardial scar, is a predictor of arrhythmic events in patients with ischemic and nonischemic cardiomyopathy. We investigated whether the presence of fQRS is associated with the severity of the anomaly and with increased arrhythmic events in adult patients with Ebstein anomaly (EA). Methods and Results—In 51 consecutive adult patients with EA (median age, 37 years; 18 males), the severity index of EA calculated from echocardiographic data and clinical arrhythmic events were analyzed. The extent of fQRS in each patient was measured by counting the number of ECG leads showing fQRS. There were 35 (68.6%) patients with fQRS (fQRS group) and 16 (31.4%) patients without fQRS (non-fQRS group). fQRS was observed more frequently in the inferior (n=26) and precordial (n=25) leads versus the lateral leads (n=5). The patients in the fQRS group had a worse functional class, greater cardiothoracic ratios, more severe tricuspid regurgitation, larger atrialized right ventricular areas, higher EA severity scores, and more frequent arrhythmic events compared with those in the non-fQRS group. The atrialized right ventricular area showed a positive correlation with the fQRS extent (r=0.51; P<0.001). In multivariable Cox regression models, the presence of fQRS was independently associated with arrhythmic events (P=0.036). Conclusions—Fragmented QRS on 12-lead ECG was associated with larger atrialized right ventricular area and an increased risk of arrhythmic events in adult patients with EA.

Routine Screening for Abdominal Aortic Aneurysm during Clinical Transthoracic Echocardiography in a Korean Population

Background: An abdominal aortic aneurysm (AAA) is potentially fatal when ruptured. Whereas the transthoracic echocardiography (TTE) protocol does not routinely include examination of the infrarenal abdominal aorta, the protocol is performed quickly and easily for AAA screening. Aim: The aim of this study was to evaluate the clinical utility of the protocol for AAA screening during TTE in a Korean population referred for clinical TTE. Methods: All of the patients who were scheduled for TTE were enrolled in the study. At the end of TTE protocol, the abdominal aorta was evaluated at the level below the renal artery origin. Results: A total of 6,267 patients were screened, and the abdominal aortas were visualized in 79% (4,939 patients) of patients screened. AAA was diagnosed in 27 patients, 23 of whom were male. The mean age of AAA patients was 66.5 years old, and 81% of AAA patients were over 60 years old. The presence of AAA was associated with male gender and older age, as well as with hypertension and smoking. Of the 27 patients, 11 patients (0.2% of the study population) did not have a history of AAA screening and were newly diagnosed by TTE. Conclusions: Screening of AAA during TTE is easy and feasible. Even though the prevalence of AAA in patients is very low, detection of asymptomatic AAA may save lives. Therefore, opportunistic examination of the abdominal aorta during routine TTE, which involves little time and cost, would appear to be effective, at least in patients over 60 years of age, especially in men. (Echocardiography 2010;27:1182‐1187)

Presence of simple renal cysts is associated with increased risk of aortic dissection: a common manifestation of connective tissue degeneration?

Objective Aortic dissection is a multifactorial disease whose primary pathology is connective tissue degeneration of the aortas medial layer. It was hypothesised that the presence of renal cysts, another possible manifestation of connective tissue weakness, would be associated with increased risk of aortic dissection. Methods The incidence of simple renal cysts on CT angiography in 518 patients with aortic dissection (AD group) and 1366 healthy subjects (control group) who underwent CT for routine health screening was compared. To reduce the effects of selection bias and confounding variables, data were adjusted by propensity score matching. Results The prevalence of simple renal cysts was 37.8% in the AD group and 22.0% in the control group, a statistically significant difference (p<0.0001). The prevalence of renal cysts was even greater in patients with the following characteristics: intramural haematoma, type B dissection, normal blood pressure or advanced age. In the 311 matched cohorts after propensity score matching, the prevalence of simple renal cysts was still significantly higher in the AD group than in the control group (33.8% vs 25.7%, p=0.023). Multivariate analysis confirmed that the presence of renal cysts (OR 1.49, p=0.0245) could be a marker of having a common underlying mechanism with aortic dissection. Conclusion Patients with aortic dissection have an increased burden of renal cysts compared with healthy controls. This finding suggests that the connective tissue weakness that predisposes patients to renal cysts may be associated with aortic dissection.

Determinants of brachial-ankle pulse wave velocity and carotid-femoral pulse wave velocity in healthy Koreans.

The aim of this study was to determine the normal value of brachial-ankle pulse wave velocity (baPWV) and carotid-femoral pulse wave velocity (cfPWV) according to age group, gender, and the presence of cardiovascular risk factors in healthy Koreans, and to investigate the association between PWV and risk factors such as prehypertension, dyslipidemia, smoking, and obesity. We measured an arterial stiffness in 110 normal subjects who were 20 to 69 yr-old with no evidence of cardiovascular disease, cerebrovascular accident or diabetes mellitus. The mean values of baPWV and cfPWV were 12.6 (±2.27) m/sec (13.1±1.85 in men, 12.1±2.51 in women; P=0.019) and 8.70 (±1.99) m/sec (9.34±2.13 in men, 8.15±1.69 in women; P=0.001), respectively. The distribution of baPWV (P<0.001) and cfPWV (P=0.006) by age group and gender showed an increase in the mean value with age. Men had higher baPWV and cfPWV than women (P<0.001). There was a difference in baPWV and cfPWV by age group on prehypertension, dyslipidemia, current smoking, or obesity (P<0.001). In multiple linear regression, age and prehypertension were highly associated with baPWV and cfPWV after adjustment for confounding factors (P<0.001). The present study showed that baPWV and cfPWV are associated with age, gender, and prehypertension in healthy Koreans. Graphical Abstract