Increased β-catenin accumulation and nuclear translocation are associated with concentric hypertrophy in cardiomyocytes

Defective Wnt/β-Catenin signaling, activated under various pathological conditions, can result in cardiac and vascular abnormalities. In the present study, the possible role of β-catenin over expression during cardiac hypertrophy was investigated. Ten samples from hearts of human patients with acute infarction, and granulation tissue from 20 patients and 10 from normal ones were collected in order to investigate roles of β-catenin in cardiac hypertrophy. H9c2 cardiomyoblast cells and Wistar rat primary neonatal cardiomyocytes were overexpressed with β-catenin. Expression levels of β-catenin protein were increased in human acute infarction tissues and rat hypertension heart tissues. Overexpression of this transcription factor induced actin filament formation and increased hypertrophic marker protein levels via MAPK pathway. In addition, β-catenin overexpression also resulted in increased elevation of NFATc3 and p-GATA4. Therefore, acute infarction resulted in β-catenin overexpression mediated hypertrophy in cardiomyocytes regulated through MAPK pathway.

Lumbrokinase from earthworm extract ameliorates second-hand smoke-induced cardiac fibrosis

Exposure to tobacco smoke has epidemiologically been linked to the occurrence of cardiovascular disease among nonsmokers but the associated molecular events are not well elucidated yet. When Sprague Dawley rats were exposed to second-hand tobacco cigarette smoke twice a day for a 30 days period at an exposure rate of 10 cigarettes/30 min, they showed adverse effects including reduced left ventricle weight, increased cardiac damages, deteriorated cardiac features, and cardiac fibrosis. Exposure to second-hand smoking (SHS) increased the molecular markers of cardiac fibrosis such as urokinase plasminogen activator and matrix metallopeptidases. The modulations in the protein levels were led by the activation of extracellular signal-regulated kinases (ERK1/2), the transcription factor-specificity protein 1 (SP1), and the fibrogenic master switch-connective for epithelial-mesenchymal transition tissue growth factor there by indicating their effective role in SHS-induced myocardial infraction. Dilong, an edible earthworm extract used in Chinese medicine and its bioactive fibrinolytic enzyme product-lumbrokinase, when administered in rats, restricted the SHS exposure induced cardiac fibrosis and provided cardio-protection. The results show that lumbrokinase and dilong administration can efficiently prevent epidemiological incidence of cardiac disease among SHS-exposed nonsmokers.

Status of trace elements in patients with idiopathic dilated cardiomyopathy in central Taiwan

BACKGROUND

Sporadic cases of dilated cardiomyopathy (DCM) are often seen in central Taiwan. Though trace elements may play a role in the pathogenesis of idiopathic DCM, there are no reports concerning study of Taiwan's population in relation to trace elements in patients with DCM.

METHODS

Serum selenium, zinc, copper and iron concentrations and blood glutathione peroxidase (GPX) activity were measured in 32 patients with DCM (24 males, 8 females; mean age, 44 +/- 14 years) and 31 age-matched normal volunteers (16 males, 15 females; mean age, 38 +/- 12 years).

RESULTS

The average serum selenium concentration of 27.6 +/- 8.4 micrograms/l found in the DCM group was significantly lower than the average concentration of 47.2 +/- 14.7 micrograms/l in the normal group. Blood GPX activity was also significantly lower in the DCM group than in the normal group. Serum selenium concentration correlated well with blood GPX activity in the studied subjects. Serum copper and iron concentrations were significantly higher in the DCM group than in the normal group. There was no difference in serum zinc concentration between the two groups.

CONCLUSIONS

Deficiency of serum selenium in association with a low blood GPX activity, and high serum copper and iron concentrations, are found in patients with idiopathic DCM in central Taiwan.

The prognostic value of ambulatory blood pressure monitoring in untreated mild-to-moderate hypertensive patients: correlation with echocardiography

BACKGROUND

Target organ damage by hypertension should be related to the daily duration of blood pressure elevation.

METHODS

Thirty-six previously untreated patients with mild to moderate hypertension were examined by 2-D, M-mode, Doppler echocardiography and with 24-hour ambulatory blood pressure monitoring. The resulting parameters were compared with those of normotensive subjects. Elevated BP values during the waking hours (> 125/85 mmHg) and sleeping hours (> 115/80 mmHg) were used to calculate the total percentage of abnormal BP values (load) in each patients.

RESULTS

In patients with hypertension, left atrial index and left ventricular mass index were significantly greater than those of normotensive subjects (21 +/- 4 vs 18 +/- 3 mm/m2, p < 0.05; 127 +/- 25 vs 94 +/- 19 gm/m2, p < 0.01). Doppler measurement of diastolic filling velocity was significantly different between the two groups, with an early LV filling velocity lower (38 +/- 11 vs 45 +/- 10 cm/sec, p < 0.05) and a late LV filling velocity higher (50 +/- 9 vs 45 +/- 12 cm/sec, p < 0.05) in the hypertensives. Casual systolic and diastolic BP values did not correlate with cardiac structural and functional variables. There were significantly inverse correlations between both sleeping diastolic blood pressure and sleeping DBP load and fractional shortening (r = -0.39, p < 0.05; r = -0.43, p < 0.01, respectively).

CONCLUSIONS

These data showed that the majority of patients with hypertension have either cardiac structural or functional abnormalities, or both. High nocturnal diastolic blood pressure and DBP load may have a more determinant effect on systolic function in mild to moderate hypertensive patients.