BackgroundMyocardial ischemia injury is one of the leading causes of death and disability worldwide. Cardiac fibroblasts (CFs) have central roles in modulating cardiac function under pathophysiological conditions. Activating transcription factor 3 (ATF3) plays a self-protective role in counteracting CF dysfunction. However, the precise function of CF-specific ATF3 during myocardial infarction (MI) injury/repair remains incompletely understood. The aim of this study was to determine whether CF-specific ATF3 affected cardiac repair after MI.

MethodsFifteen male C57BL/6 wild-type mice were performed with MI operation to observe the expression of ATF3 at 0, 0.5, 1.0, 3.0, and 7.0 days postoperation. Model for MI was constructed in ATF3TGfl/flCol1a2-Cre+ (CF-specific ATF3 overexpression group, n = 5) and ATF3TGfl/flCol1a2-Cre- male mice (without CF-specific ATF3 overexpression group, n = 5). In addition, five mice of ATF3TGfl/flCol1a2-Cre+ and ATF3TGfl/flCol1a2-Cre- were subjected to sham MI operation. Heart function was detected by ultrasound and left ventricular remodeling was observed by Masson staining (myocardial fibrosis area was detected by blue collagen deposition area) at the 28 day after MI surgery in ATF3TGfl/flCol1a2-Cre+ and ATF3TGfl/flCol1a2-Cre- mice received sham or MI operation. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect cell proliferation/cell cycle-related gene expression in cardiac tissue. BrdU staining was used to detect fibroblast proliferation.

ResultsAfter establishment of an MI model, we found that ATF3 proteins were increased in the heart of mice after MI surgery and dominantly expressed in CFs. Genetic overexpression of ATF3 in CFs (ATF3TGfl/flCol1a2-Cre+ group) resulted in an improvement in the heart function as indicated by increased cardiac ejection fraction (41.0% vs. 30.5%, t = 8.610, P = 0.001) and increased fractional shortening (26.8% vs. 18.1%, t = 7.173, P = 0.002), which was accompanied by a decrease in cardiac scar area (23.1% vs. 11.0%, t = 8.610, P = 0.001). qRT-PCR analysis of CFs isolated from ATF3TGfl/flCol1a2-Cre+ and ATF3TGfl/flCol1a2-Cre- ischemic hearts revealed a distinct transcriptional profile in ATF3-overexpressing CFs, displaying pro-proliferation properties. BrdU-positive cells significantly increased in ATF3-overexpressing CFs than control CFs under angiotensin II stimuli (11.5% vs. 6.8%, t = 31.599, P = 0.001) or serum stimuli (31.6% vs. 20.1%, t = 31.599, P = 0.001). The 5(6)-carboxyfluorescein N-hydroxysuccinimidyl ester assay showed that the cell numbers of the P2 and P3 generations were higher in the ATF3-overexpressing CFs at 24 h (P2: 91.6% vs. 71.8%, t = 8.465, P = 0.015) and 48 h (P3: 81.6% vs. 51.1%, t = 9.029, P = 0.012) after serum stimulation. Notably, ATF3 overexpression-induced CF proliferation was clearly increased in the heart after MI injury.

ConclusionsWe identify that CF-specific ATF3 might contribute to be MI repair through upregulating the expression of cell cycle/proliferation-related genes and enhancing cell proliferation.

Activating Transcription Factor 3 ; physiology ; Animals ; Disease Models, Animal ; Fibroblasts ; physiology ; Fibrosis ; Male ; Mice ; Mice, Inbred C57BL ; Myocardial Infarction ; Myocardium ; Ventricular Remodeling

To investigate changes in the angiotensin converting enzyme 2 (ACE2) and angiotensin (1-7) [Ang (1-7)] and to explore the role of ACE2-Ang (1-7)-Mas receptor axis in hypertension with heart failure with preserved ejection fraction (HFPEF).
 Methods: A total of 70 patients with primary hypertension and preserved left ventricular ejection fraction (LVEF>50%) were recruited and patients were divided into a hypertension group (HBP) and a heart failure with preserved ejection fraction group (HFpEF) according to the diagnostic criteria of HFpEF. Thirty-five healthy participants were selected randomly as a control group. Enzyme linked immunosorbent assays (ELISA) method was used to detect concentration of Ang (1-7), ACE2, angiotensin II (Ang II), brain natriuretic peptide (BNP) in plasma. Male Sprague- Dawley (SD) rats was randomly divided into 2 groups: An HFpEF group (n=16) and a sham group (n=8). Rats (n=8) in the AAC group were given Ang (1-7) [0.5 mg/(kg.d), intraperitoneally] for 6 weeks, and the rest were given equal dose normal saline. Then all the rats were killed, and the hearts were taken out for hematoxylineosin (HE) staining. The protein expressions of angiotensin converting enzyme (ACE), ACE2, and Mas receptor were detected by Western blot.
 Results: The BNP and Ang II were significantly increased in the HBP group and the HFpEF group compared with the control group (P<0.01). There were not significantly different in levels of ACE2 and Ang (1-7) between the HBP group and control group (P>0.05), whereas those levels were significantly increased in the HFpEF group compared with the HBP group and control group (P<0.01). HE staining showed obvious hypertrophy of myocardial cell in the AAC group compared with the sham group. Hypertrophy of myocardial cell in the AAC+Ang (1-7) group was significantly higher than that in the AAC group. Expressions of ACE, ACE2, and Mas receptor proteins were significantly higher in the AAC group than those in the sham group (P<0.05), while the expressions of ACE2 and Mas receptor proteins in the AAC+Ang (1-7) group were significantly higher than those in the AAC group (P<0.05). There was no significant difference in the ACE protein expression between groups (P>0.05).
 Conclusion: ACE2 and Ang (1-7) are important predictive factors for the severity of heart failure and myocardial remodeling of HFpEF with hypertension; ACE2-Ang (1-7)-Mas receptor axis may play a protective role in preventing myocardial remodeling in HFpEF with hypertension.
Angiotensin I ; physiology ; Angiotensin II ; Animals ; Atrial Remodeling ; physiology ; Case-Control Studies ; Enzyme-Linked Immunosorbent Assay ; Heart Failure ; metabolism ; physiopathology ; Humans ; Hypertension ; metabolism ; physiopathology ; Male ; Peptide Fragments ; physiology ; Peptidyl-Dipeptidase A ; physiology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; physiology ; Stroke Volume ; Ventricular Function, Left ; physiology ; Ventricular Remodeling ; physiology

BACKGROUND: A biomarker that is of great interest in relation to adverse cardiovascular events is soluble ST2 (sST2), a member of the interleukin family. Considering that metabolic syndrome (MetS) is accompanied by a proinflammatory state, we aimed to assess the relationship between sST2 and left ventricular (LV) structure and function in patients with MetS. METHODS: A multicentric, cross-sectional study was conducted on180 MetS subjects with normal LV ejection fraction as determined by echocardiography. LV hypertrophy (LVH) was defined as an LV mass index greater than the gender-specific upper limit of normal as determined by echocardiography. LV diastolic dysfunction (DD) was assessed by pulse-wave and tissue Doppler imaging. sST2 was measured by using a quantitative monoclonal ELISA assay. RESULTS: LV mass index (β=0.337, P<0.001, linear regression) was independently associated with sST2 concentrations. Increased sST2 was associated with an increased likelihood of LVH [Exp (B)=2.20, P=0.048, logistic regression] and increased systolic blood pressure [Exp (B)=1.02, P=0.05, logistic regression]. Comparing mean sST2 concentrations (adjusted for age, body mass index, gender) between different LV remodeling patterns, we found the greatest sST2 level in the group with concentric hypertrophy. There were no differences in sST2 concentration between groups with and without LV DD. CONCLUSIONS: Increased sST2 concentration in patients with MetS was associated with a greater likelihood of exhibiting LVH. Our results suggest that inflammation could be one of the principal triggering mechanisms for LV remodeling in MetS.
Adult ; Age Factors ; Aged ; Area Under Curve ; Blood Pressure ; Body Mass Index ; Cross-Sectional Studies ; Echocardiography, Doppler ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Hypertrophy, Left Ventricular/diagnostic imaging ; Interleukin-1 Receptor-Like 1 Protein/*analysis ; Linear Models ; Logistic Models ; Male ; Metabolic Syndrome X/metabolism/*physiopathology ; Middle Aged ; ROC Curve ; Sex Factors ; Ventricular Function, Left/*physiology ; Ventricular Remodeling/physiology

BACKGROUNDThe primary cause of ischemic heart failure (HF) is myocardial infarction (MI) resulting in left ventricle (LV) wall motion abnormality secondary to ventricular remodeling. A prospective, nonrandomized study conducted in China was designed to assess safety and efficacy of the percutaneous ventricular restoration therapy using Parachute device (CardioKinetix, Inc., CA, USA) in ischemic HF patients as a result of LV remodeling after anterior wall MI.

METHODSThirty-one patients with New York Heart Association (NYHA) Class II, III ischemic HF, ejection fraction between 15% and 40%, and dilated akinetic or dyskinetic anterior-apical wall without the need to be revascularized were enrolled from seven sites in China from October to December 2014. The Parachute device was implanted through femoral artery. All patients received low-dose aspirin and anticoagulation with warfarin for at least 12 months postdevice implantation. The primary end-point was the assessment of efficacy as measured by the reduction in LV end-systolic volume index (LVESVI) against baseline LVESVI at 3 months postdevice implantation, determined by the echocardiography and measured by echocardiography core laboratory. Quality of life was assessed using EQ-5D and visual analog scale (VAS). For quantitative data comparison, paired t-test (normality data) and signed-rank test (abnormality data) were used; application of signed-rank test was for the ranked data comparison.

RESULTSA change in LVESVI as measured by echocardiography from the preimplant baseline to 3-month postdevice implantation revealed a statistically significant reduction from 77.5 ± 20.0 ml/m2 to 53.1 ± 17.0 ml/m2 (P < 0.0001). The trial met its primary end-point. Of the 31 patients, the procedural success was 96.8%. Overall, NYHA HF class assessment results showed an improvement of more than half a class at 3 months (P < 0.001). Quality of life assessed by the VAS value increased 11.5 points (P < 0.01), demonstrating improvement at 3 months.

CONCLUSIONThe favorable outcomes observed in the high-risk patients provide reassuring safety and efficacy data to support adoption of this technology as a therapeutic option for ischemic HF patients.

TRIAL REGISTRATIONClinicalTrials.gov, NCT02240940; https://clinicaltrials.gov/ct2/show/NCT02240940.

Aged ; China ; Female ; Heart Failure ; physiopathology ; surgery ; Heart Ventricles ; physiopathology ; surgery ; Humans ; Male ; Middle Aged ; Prospective Studies ; Prosthesis Implantation ; adverse effects ; methods ; Stroke Volume ; physiology ; Treatment Outcome ; Ventricular Remodeling ; physiology

OBJECTIVE: To explore the role of calpain in pulmonary vascular remodeling in hypoxia-induced pulmonary hypertension and the underlying mechanisms.
 METHODS: Sprague-Dawley rats were randomly divided into the hypoxia group and the normoxia control group. Right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) were monitored by a method with right external jugular vein cannula. Right ventricular hypertrophy index was presented as the ratio of right ventricular weight to left ventricular weight (left ventricle plus septum weight). Levels of calpain-1, -2 and -4 mRNA in pulmonary artery were determined by real-time PCR. Levels of calpain-1, -2 and -4 protein were determined by Western blot. Primary rat pulmonary arterial smooth muscle cells (PASMCs) were divided into 4 groups: a normoxia control group, a normoxia+MDL28170 group, a hypoxia group and a hypoxia+MDL28170 group. Cell proliferation was detected by MTS and flow cytometry. Levels of Ki-67 and proliferating cell nuclear antigen (PCNA) mRNA were determined by real-time PCR.
 RESULTS: RVSP, mPAP and right ventricular remodeling index were significantly elevated in the hypoxia group compared to those in the normoxia group. In the hypoxia group, pulmonary vascular remodeling was significantly developed, accompanied by up-regulation of calpain-1, -2 and -4. MDL28170 significantly inhibited hypoxia-induced proliferation of PASMCs concomitant with the suppression of Ki-67 and PCNA mRNA expression.
 CONCLUSION Calpain mediates vascular remodeling via promoting proliferation of PASMCs in hypoxia-induced pulmonary hypertension.
Animals ; Calpain ; genetics ; physiology ; Cell Proliferation ; Dipeptides ; physiology ; Hypertension, Pulmonary ; chemically induced ; genetics ; physiopathology ; Hypertrophy, Right Ventricular ; Hypoxia ; Ki-67 Antigen ; drug effects ; Myocytes, Smooth Muscle ; physiology ; Proliferating Cell Nuclear Antigen ; drug effects ; Pulmonary Artery ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Up-Regulation ; Vascular Remodeling ; genetics ; physiology

OBJECTIVE: Post-contrast T1 values are closely related to the degree of myocardial extracellular space expansion. We determined the relationship between post-contrast T1 values and left ventricular (LV) diastolic function, LV remodeling, and neurohormonal activation in patients with dilated cardiomyopathy (DCM). MATERIALS AND METHODS: Fifty-nine patients with DCM (mean age, 55 +/- 15 years; 41 males and 18 females) who underwent both 1.5T magnetic resonance imaging and echocardiography were enrolled. The post-contrast 10-minute T1 value was generated from inversion time scout images obtained using the Look-Locker inversion recovery sequence and a curve-fitting algorithm. The T1 sample volume was obtained from three interventricular septal points, and the mean T1 value was used for analysis. The N-Terminal pro-B-type natriuretic peptide (NT-proBNP) level was measured in 40 patients. RESULTS: The mean LV ejection fraction was 24 +/- 9% and the post-T1 value was 254.5 +/- 46.4 ms. The post-contrast T1 value was significantly correlated with systolic longitudinal septal velocity (s'), peak late diastolic velocity of the mitral annulus (a'), the diastolic elastance index (Ed, [E/e']/stroke volume), LV mass/volume ratio, LV end-diastolic wall stress, and LV end-systolic wall stress. In a multivariate analysis without NT-proBNP, T1 values were independently correlated with Ed (beta = -0.351, p = 0.016) and the LV mass/volume ratio (beta = 0.495, p = 0.001). When NT-proBNP was used in the analysis, NT-proBNP was independently correlated with the T1 values (beta = -0.339, p = 0.017). CONCLUSION: Post-contrast T1 is closely related to LV remodeling, diastolic function, and neurohormonal activation in patients with DCM.
Adult ; Aged ; Algorithms ; Blood Pressure ; Cardiomyopathy, Dilated/*diagnosis/radiography ; Echocardiography ; Extracellular Space/physiology/*radiography ; Female ; Heart Ventricles/physiopathology/radiography ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Multivariate Analysis ; Natriuretic Peptide, Brain/analysis ; Peptide Fragments/analysis ; *Ventricular Remodeling

This study was aimed to establish an experimental mouse model of combined transgenic inhibition of both multifunctional Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and inward rectifier potassium current (Ik1), and to observe whether the specific inhibition of both CaMKII and Ik1 can bring about any effects on cardiac remodeling. Mice were divided into 4 groups: wild type (WT), CaMKII inhibited (AC3-I), Ik1 inhibited (Kir2.1-AAA) and combined inhibition of both CaMKII and Ik1 (AC3-I+Kir2.1-AAA). Mice in each group received electrocardiogram (ECG) and echocardiography examination. ECG in the condition of isoproterenol (ISO) injection was also checked. The whole cell patch clamp technique was used to measure Ik1 and the transient outward potassium current (Ito) from enzymatically isolated myocytes of left ventricle. In the condition of basal status, no significant changes of heart rate, PR interval and QRS interval were observed. No mouse showed ventricular arrhythmias in all of the 4 groups. After ISO injection, each group presented no significant ventricular arrhythmias either. The indexes measured by M-mode (motion-mode) and two-dimensional echocardiography had no significant differences among the four groups. Ik1 in AC3-I group was significantly higher than those in other three groups (P < 0.01) because of the results brought about by CaMKII inhibition. Among the latter three groups, both Kir2.1-AAA group and AC3-I+Kir2.1-AAA group had a significant reduced Ik1 compared with that of WT group, which was due to the Ik1 inhibition (P < 0.01). Ito in AC3-I group was higher than that of the other three groups (P < 0.01), but there were no significant differences in Ito among WT, Kir2.1-AAA and AC3-I+Kir2.1-AAA groups. Thus, combined transgenic myocardial CaMKII and Ik1 inhibition eliminated the up-regulation of Ik1 in CaMKII inhibited mice, and had no effects on cardiac remodeling including heart structure and function as well as arrhythmias at the basic and ISO conditions. The results of this study may provide a basis for the further investigation of combined inhibition of CaMKII and Ik1 in pathogenic cardiac remodeling.
Animals ; Arrhythmias, Cardiac ; Brugada Syndrome ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; physiology ; Cardiac Conduction System Disease ; Disease Models, Animal ; Electrocardiography ; Heart ; physiology ; Heart Conduction System ; abnormalities ; Heart Ventricles ; Isoproterenol ; Mice ; Mice, Transgenic ; Patch-Clamp Techniques ; Potassium Channels, Inwardly Rectifying ; physiology ; Up-Regulation ; Ventricular Remodeling

BACKGROUNDHepatocyte growth factor (HGF) inhibits the development of pulmonary artery hypertension (PAH) by reducing pulmonary artery pressure and right ventricle (RV) hypertrophy. However, whether HGF can prevent RV remodeling via inhibiting apoptosis in RV cardiomyocytes and decreasing neurohormonal activation remains unknown.

METHODSThe PAH and subsequent RV remodeling in rats were induced by subcutaneous injection of monocrotaline (MCT). The PAH rats were transfected with adenovirus carrying HGF (Ad-HGF) via intratracheal instillation. Three weeks after transfection, the hemodynamics indexes were measured, serum levels for angiotonin II (ANG II) and brain natriuretic peptide (BNP) were determined by ELISA. Histological analysis was used to assess the RV hypertrophy and fibrosis. The cardiomyocyte apoptosis in RV was assayed by TUNEL staining. The mRNA expression of BNP, angiotensin-converting enzyme (ACE), Bax and Bcl-2 in RV was determined by reverse transcriptase polymerase chain reaction (RT-PCR), the protein expression of transforming growth factor (TGF)-β1 and tumor necrosis factor (TNF)-α in RV was determined by Western blotting.

RESULTSHGF treatment significantly decreased the mean PAH, RV systolic pressure, serum ANG II and BNP levels. HGF treatment also significantly decreased the RV hypertrophy, collagen deposition, and the number of apoptotic cardiomyocytes. Moreover, HGF treatmemt significantly decreased the expression of BNP, ACE, Bax, TGF-β1, and TNF-α, while it significantly increased the expression of Bcl-2.

CONCLUSIONSGene transfer of HGF decreases MCT-induced PAH and improves RV remodeling. This effect is mediated not only by improving the hemodynamics but also by decreasing neurohormonal activation and inhibiting cardiomyocytes apoptosis. HGF gene treatment may be an effective strategy for improving RV remodeling in MCT-induced PAH.

Animals ; Apoptosis ; genetics ; physiology ; Hepatocyte Growth Factor ; genetics ; physiology ; therapeutic use ; Humans ; Hypertension, Pulmonary ; metabolism ; therapy ; Male ; Rats ; Rats, Sprague-Dawley ; Ventricular Remodeling ; genetics ; physiology

PURPOSE: Coronary flow reserve (CFR) in the non-infarcted myocardium is often impaired following acute myocardial infarction (AMI). However, the clinical significance of CFR in the non-infarcted myocardium is not fully understood. The objective of the present study was to assess whether a relationship exists between CFR and left ventricular remodeling following AMI. MATERIALS AND METHODS: We enrolled 18 consecutive patients undergoing coronary intervention. Heart function was analyzed using real-time myocardial contrast echocardiography at one week and six months after coronary angioplasty. Ten subjects were enrolled as the control group and were examined using the same method at the same time to assess CFR. Cardiac troponin I (cTnI) levels were routinely analyzed to estimate peak concentration. RESULTS: CFR was 1.55+/-0.11 in the infarcted zone and 2.05+/-0.31 in the remote zone (p<0.01) at one week following AMI. According to CFR values in the remote zone, all patients were divided into two groups: Group I (CFR <2.05) and Group II (CFR >2.05). The levels of cTnI were higher in Group I compared to Group II on admission (36.40 vs. 21.38, p<0.05). Furthermore, left ventricular end diastolic volume was higher in Group I compared to Group II at six months following coronary angioplasty. CONCLUSION: Microvascular dysfunction is commonly observed in the remote myocardium. The CFR value accurately predicts adverse ventricular remodeling following AMI.
Aged ; Coronary Angiography ; Coronary Circulation/physiology ; Female ; Humans ; Male ; Middle Aged ; Myocardial Infarction/*physiopathology/radiography ; Myocardium/*pathology ; Ventricular Remodeling/*physiology

PURPOSE: Coronary flow reserve (CFR) in the non-infarcted myocardium is often impaired following acute myocardial infarction (AMI). However, the clinical significance of CFR in the non-infarcted myocardium is not fully understood. The objective of the present study was to assess whether a relationship exists between CFR and left ventricular remodeling following AMI. MATERIALS AND METHODS: We enrolled 18 consecutive patients undergoing coronary intervention. Heart function was analyzed using real-time myocardial contrast echocardiography at one week and six months after coronary angioplasty. Ten subjects were enrolled as the control group and were examined using the same method at the same time to assess CFR. Cardiac troponin I (cTnI) levels were routinely analyzed to estimate peak concentration. RESULTS: CFR was 1.55+/-0.11 in the infarcted zone and 2.05+/-0.31 in the remote zone (p<0.01) at one week following AMI. According to CFR values in the remote zone, all patients were divided into two groups: Group I (CFR <2.05) and Group II (CFR >2.05). The levels of cTnI were higher in Group I compared to Group II on admission (36.40 vs. 21.38, p<0.05). Furthermore, left ventricular end diastolic volume was higher in Group I compared to Group II at six months following coronary angioplasty. CONCLUSION: Microvascular dysfunction is commonly observed in the remote myocardium. The CFR value accurately predicts adverse ventricular remodeling following AMI.
Aged ; Coronary Angiography ; Coronary Circulation/physiology ; Female ; Humans ; Male ; Middle Aged ; Myocardial Infarction/*physiopathology/radiography ; Myocardium/*pathology ; Ventricular Remodeling/*physiology