OBJECTIVE: To investigate the optimal time window for observation of catheter-induced valve injury that mimics calcified aortic valve disease in mice. METHODS: A catheter was inserted into the right common carotid artery of 8-week-old C57BL6 mice under ultrasound guidance, and aortic valve injury was induced using the guide wire.At 4, 8 and 16 weeks after modeling, the mice were subjected to ultrasound measurement of the heart short axial shortening rate, aortic valve peak velocity and aortic valve orifice area.Grain-Eosin staining was used to observe the changes in the thickness of the aortic valve, and calcium deposition in the aortic valve was assessed using Alizarin red staining.Immunofluorescence assay was performed to detect the expression of alkaline phosphatase (ALP) in the aortic valve. RESULTS: At 4, 8 and 16 weeks after modeling, valve thickness (P=0.002), calcium deposition (P < 0.0001) and the expression of osteogenic protein ALP (P=0.0016) were significantly increased, but their increments were comparable at the 3 time points of observation. CONCLUSION In mouse models of calcific aortic valve disease induced by catheter valve injury, 4 weeks after the injury appears to be the optimal time window for observation of pathophysiological changes in the aortic valves to avoid further increase of the death rate of the mice over time.
Animals ; Mice ; Aortic Valve/metabolism* ; Calcium/metabolism* ; Mice, Inbred C57BL ; Aortic Valve Stenosis/metabolism* ; Catheters ; Osteogenesis ; Cells, Cultured

BACKGROUND AND OBJECTIVES: To compare the pattern of myocardial fibrosis in various valvular heart diseases (VHD), the morphometric data of the myocardial tissue and serum biochemical markers of myocardial fibrosis were analyzed in patients with aortic stenosis (AS), aortic regurgitation (AR) and mitral regurgitation (MR). SUBJECTS AND METHODS: Blood samples were obtained from 21 patients with AS, 23 with AR and 29 with MR. The serum levels of aminoterminal propeptide, of type I/III procollagen (PINP/PIIINP), and fibronectin were measured to estimate the synthesis of the extracelluar matrix. The carboxy-terminal telopeptide collagen type I (CITP), matrix metalloproteinase-1 (MMP-1, collagenase) and the tissue inhibitor, metalloproteinase-1 (TIMP-1), were also measured to estimate the collagen degradation and metabolism activities. The left ventricular mass (LVM) was calculated by echocardiography. Of the patients, myocardial tissue was obtained during surgery in 11 with AS, 8 with AR and 13 with MR;the collagen volume fraction (CVF) was calculated using picrosirius red staining. RESULTS: The LVM was significantly larger in the AS and AR groups compared to the MR group (p<0.001), and the CVF also showed significant differences (13+/-3% in AS, 10+/-3% in AR, and 6+/-3% in MR, p<0.001). The fibronectin level was significantly elevated in the AS and AR groups than the MR group (p<0.001), whereas the CITP and MMP-1 levels were significantly higher in the MR group (p<0.05). The PINP/PIIINP showed no significant difference between the groups (p>0.05), and the biochemical markers were no different between the AS and AR groups (p>0.05). Fibronectin was the only parameter showing a positive correlation with both the CVF (r=0.388, p=0.01) and the left ventricular mass (r=0.278, p=0.02). CONCLUSION: Different mechanisms for the matrix synthesis and degradation were present for the maintenance of myocardial fibrosis and hypertrophy according to the type of VHD, and fibronectin, a major non-collagenous extracelluar matrix, was proved to be an important factor associated with cardiac hypertrophy and myocardial fibrosis.
Aortic Valve Insufficiency ; Aortic Valve Stenosis ; Biomarkers ; Cardiomegaly ; Collagen ; Collagen Type I ; Echocardiography ; Fibronectins ; Fibrosis* ; Heart Valve Diseases* ; Humans ; Hypertrophy ; Matrix Metalloproteinase 1 ; Metabolism ; Mitral Valve Insufficiency ; Procollagen

OBJECTIVETo establish a mouse model of abdominal aorta stenosis and analyze the alterations in the arterial wall response to high and low shear stress.

METHODSTwenty mouse were randomized equally into 4 groups, including 3 test groups (1, 7 and 14 day groups) with surgically induced stenosis of the abdominal aorta, and a sham-operated group without stenosis. The hemodynamics and the internal diameter of the blood vessel were measured by color Doppler flow imaging. The wall shear stress was calculated by Poiseiulle hydrodynamics formula (τ(m)=η×4×V(m)/D). Pathological examination and immunohistochemistry were performed to observe the arterial morphological changes and the endothelial vascular cell adhesion molecule-1 (VCAM-1) expression. The intimal-media thickness of the aorta was measured and endothelial VCAM-1 expression analyzed quantitatively.

RESULTSRegions of low and high flow shear stress were created upstream from the stenosis and within the stenosis, respectively. Compared with the sham-operated group, the mice with aorta stenosis showed gradually increased vascular intimal-media thickness and VCAM-1 expression intensity in the upstream aorta, but not within the regions of the stenosis.

CONCLUSIONVascular remodeling may occur shortly after exposure to low shear stress, which plays a significant role in initiation and progression of the pathological process of atherosclerosis mediated by VCAM-1, whereas high shear stress may exert an anti-atherosclerotic effect.

Animals ; Aorta, Abdominal ; metabolism ; pathology ; physiopathology ; Aortic Valve Stenosis ; physiopathology ; Atherosclerosis ; physiopathology ; Constriction ; Hemodynamics ; Male ; Mice ; Shear Strength ; physiology ; Stress, Mechanical ; Vascular Cell Adhesion Molecule-1 ; metabolism

Aortic valve calcification is a common disease in the elderly, but its cellular and molecular mechanisms are not clear. In order to verify the hypothesis that Wnt/β-catenin signaling pathway is involved in the process of calcification of aortic valve, porcine aortic valve interstitial cells (VICs) were isolated, cultured and stimulated with oxidized low density lipoprotein (ox-LDL) for 48 h to induce the differentiation of VICs into osteoblast-like cells. The key proteins and genes of Wnt/β-catenin signaling pathway, such as glycogen synthase kinase 3β (GSK-3β) and β-catenin, were detected by using Western blotting and real-time polymerase chain reaction (PCR). The results showed that the VICs managed to differentiate into osteoblast-like cells after the stimulation with ox-LDL and the levels of proteins and genes of GSK-3β and β-catenin were increased significantly in VICs after stimulation for 48 h (P<0.05). It is suggested that Wnt/β-catenin signaling pathway may play a key role in the differentiation of VICs into osteoblast-like cells and make great contribution to aortic valve calcification.
Alkaline Phosphatase ; genetics ; metabolism ; Animals ; Aortic Valve ; metabolism ; pathology ; Aortic Valve Stenosis ; Blotting, Western ; Bone Morphogenetic Protein 2 ; genetics ; metabolism ; Calcinosis ; Cell Differentiation ; drug effects ; genetics ; Cells, Cultured ; Gene Expression ; drug effects ; Glycogen Synthase Kinase 3 ; genetics ; metabolism ; Lipoproteins, LDL ; pharmacology ; Osteoblasts ; drug effects ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Swine ; Wnt Signaling Pathway ; genetics ; physiology ; beta Catenin ; genetics ; metabolism

BACKGROUND/AIMS: Underlying cardiac pathology and atrial fibrillation (AF) affect the molecular remodeling of ion channels in the atria. Changes in the expression of these molecules have not been demonstrated in Korean patients with mitral valvular heart disease. Thus, the purpose of this study was to analyze ion channel expression in patients with chronic AF and mitral valvular heart disease. METHODS: A total of 17 patients (eight males and nine females; mean age, 57 +/- 14 years [range, 19 to 77]) undergoing open-heart surgery were included in the study. Twelve patients (seven with coronary artery disease and five with aortic valvular disease) had sinus rhythm, and five patients (all with mitral valvular disease) had chronic, permanent AF. A piece of right atrial appendage tissue (0.5 g) was obtained during surgery. RT-PCR was used to evaluate the expression of L-type Ca2+ channels, ryanodine receptor (RyR2), sarcoplasmic reticular Ca2+-ATPase (SERCA2), gene encoding the rapid component of the delayed rectifier Ikr (HERG), gene encoding calcium-independent transient outward current I(to1) (Kv4.3), gene encoding the ultrarapid component of the delayed rectifier Iku (Kv1.5), K+ channel-interacting protein 2 (KChIP2), hyperpolarization-activated cation channel 2 associated with the pacemaker current If (HCN2), and gene encoding Na+ channel (SCN5A). RESULTS: Reduced L-type Ca2+ channel, RyR2, SERCA2, Kv1.5, and KChIP2 expression and borderline increased HCN2 expression were observed in the patients with AF and mitral valvular heart disease. Left atrial diameter was negatively correlated with RyR2 and KChIP2 expression. Fractional area shortening of the left atrium was positively correlated with RyR2 and KChIP2 expression. CONCLUSIONS: Alterations in ion channel expression and the anatomical substrate may favor the initiation and maintenance of AF in patients with mitral valvular heart disease.
Adult ; Aged ; Aortic Valve Stenosis/metabolism ; Atrial Fibrillation/*metabolism ; Calcium/metabolism ; Chronic Disease ; Coronary Artery Disease/metabolism ; Female ; Heart Valve Diseases/*metabolism ; Humans ; Ion Channels/*genetics ; Male ; Middle Aged ; *Mitral Valve ; Potassium Channels/genetics ; Ryanodine Receptor Calcium Release Channel/genetics ; Sodium Channels/genetics

With the population aging and declining incidence of rheumatic heart disease, calcific aortic valve disease (CAVD) has become the most frequent valve disease and the common cause of aortic valve replacement. Patients with CAVD need to cope with a deteriorating quality of life and valve replacement is the only effective clinical option for the patients. Therefore, early pharmacotherapy is of great significance in prevention or slow-down of the progression of CAVD. For years CAVD was considered to be a passive wear and tear process of valves, but now it is recognized as an active and multi-factorial process. Histopathologic studies have revealed that inflammation, disorder of calcium and phosphorus metabolism and dyslipidemia are involved in the process of CAVD. Clinical trials of CAVD pharmacotherapy have been carried out based on those histopathologic studies. Statin, renin-angiotensin inhibitors and anti-osteoporosis drug are well studied in recent years. This article reviews the recent research progress of the pharmacotherapy for CAVD.
Angiotensin Receptor Antagonists ; therapeutic use ; Angiotensin-Converting Enzyme Inhibitors ; therapeutic use ; Aortic Valve ; pathology ; Aortic Valve Stenosis ; complications ; drug therapy ; etiology ; Calcinosis ; complications ; drug therapy ; etiology ; Calcium Metabolism Disorders ; complications ; Disease Progression ; Dyslipidemias ; complications ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; therapeutic use ; Inflammation ; complications ; Phosphorus Metabolism Disorders ; complications ; Quality of Life

OBJECTIVETo observe the effects of Xiongshao Capsule (XSC) on blood vessel collagenase gene expression in experimental rabbits with arterial restenosis, and to probe its mechanisms for preventing restenosis.

METHODSRestenosis rabbit model was established by injuring endothelium of abdominal aorta by balloon dilation and feeding with high fatty diet for 6 weeks. Eighty rabbits were randomly allocated into 8 groups, Group A, normal rabbit for control; Group B, rabbit with simple injured arterial endothelium; Group C, model rabbits at different times after modeling (3 days for Group C1, 2 weeks for Group C2, and 6 weeks for Group C3); Group D, model rabbit treated with Probucol for 6 weeks; Group E and F, model rabbit treated with small and large dose of XSC respectively. The effect of XSC on collagenase gene expression during the course of restenosis was observed adopting RT-PCR method and computer image analyzer, and its mechanisms in preventing RS were probed by combined analyzing the change of collagen and patho-morphological examination.

RESULTSCompensatory dilation of lumens appeared at the end of the 2nd week; while 6 weeks after modeling, the diameters of lumens obviously diminished with an apparently increased proliferation index. The cell proliferation inhibiting effect in Group D and F was significant. The total amount of collagen increased and reached the peak at the 2nd week but without conspicuous accumulation on intima, which increased gradually and reached its peak at the 6th week. In Group D-F, especially in Group F, the amount of collagen in vascular wall (intima, media and externa) was lesser than that in Groups C. MMP-1 mRNA showed weak expression in Group A and Group C1-C3; significant difference only existed in comparing Group F with C3 (P < 0.05).

CONCLUSIONXSC could markedly increase the MMP-1 mRNA expression in injured portion of vessels, suggesting that its action in preventing RS might be related with the up-regulating of MMP-1 mRNA expression, increasing collagen degradation and reducing collagen deposition in vascular wall.

Animals ; Aorta, Abdominal ; drug effects ; metabolism ; pathology ; Aortic Valve Stenosis ; enzymology ; etiology ; prevention & control ; Capsules ; Catheterization ; adverse effects ; Drugs, Chinese Herbal ; pharmacology ; Endothelium, Vascular ; drug effects ; metabolism ; pathology ; Female ; Gene Expression Regulation, Enzymologic ; drug effects ; Male ; Matrix Metalloproteinase 1 ; genetics ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Rabbits ; Random Allocation ; Reverse Transcriptase Polymerase Chain Reaction