Abstract 382: Kidney-Heart Connection: One Kidney Nephrectomy Results in Cardiac Fibrosis and Differential Ventricular Gene Profiles in the Absence of Heart Failure

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Fernando L Martin ◽  
Brenda K Huntley ◽  
Gerald E Harders ◽  
John C Burnett

Background: Decreased renal function is associated with increased cardiovascular morbidity and mortality by mechanisms that remain unclear. We hypothesized that even mild renal insufficiency produced by unilateral nephrectomy results in changes in ventricular structure and gene expression in the absence of hypertension or volume overload underscoring a kidney-heart connection in the control of myocardial structure. Methods: Cardiorenal function and structure were assessed in Wistar rats [sham (S; n=10) and unilateral nephrectomized (UNX; n=9)] 4 weeks after UNX. GFR was determined by inulin clearance and renal blood flow (RBF) by PAH. Blood was obtained for BNP, PRA, and aldosterone. Hearts and kidneys were harvested for histological analysis. Cardiac function was assessed by echo. Genome-wide microarray analysis was performed on left ventricular myocardium (Affymetrix GeneChip® Rat Genome 230 2.0). Results: Glomerular hypertrophy was observed in UNX (S:1±0.04, Nx:1.6±0.1 u3x106, p<0.001). GFR tended to decrease with a reduction in RBF (S:8±1, Nx:5±1 ml/min, p<0.005). Sodium and water excretions were not different between groups with no activation of PRA, aldosterone or BNP. LVEF and LV end-systolic and end-diastolic diameters were normal. Blood pressure (BP) was not different between groups. Importantly, Picrosirius Red staining in the ventricular myocardium of UNX compared to S revealed greater fibrosis (S:2.4±0.1, Nx:4.2±0.4 %, p<0.001). Further, microarray analysis of ventricular myocardium revealed that 278 genes significantly changed with UNX (1.5 fold, P<0.05) compared to S in genes related to cell growth, bone remodeling and muscle contraction (Z value>2). Conclusion: We conclude that even mild renal insufficiency produced by unilateral nephrectomy initiates myocardial gene responses and fibrosis independent of alterations in the circulating RAAS, BNP, BP, volume overload or systolic dysfunction. These studies support a kidney - heart connection in early renal dysfunction resulting in molecular ventricular remodeling and fibrosis. These studies in experimental mild renal dysfunction produced by removal of one kidney reveal a renal mediated mechanism for myocardial remodeling.

2021 ◽  
Vol 9 (B) ◽  
pp. 1677-1680
Author(s):  
Rahmat Budi Kuswiyanto ◽  
Putria Apandi ◽  
Dany Hilmanto ◽  
Muhammad Hasan Bashari ◽  
Sri Endah Rahayuningsih

Background: Brain natriuretic peptide is a cardiac hormone secreted from the left ventricular myocardium due to ventricular expansion and volume overload. A recent study shows that small VSD will have risk of ventricular dysfunction in adulthood. Another complications such as endocarditis, congestive heart failure, aortic regurgitation, arrhythmia also we should be aware. Evaluations of the plasma B-type natriuretic peptide level (NT pro BNP) are currently being considered as methods to identify the possible presence of ventricular dilation in small VSD. Objective: To evaluate the change in plasma B-type natriuretic peptide after transcatheter closure of VSD. Methods: A pretest-posttest design was conducted on VSD patients before and after transcatheter closure. Plasma B-type natriuretic peptide level were measured before and 30 days after the transcatheter closure of VSD. Result: A total of 32 peri membranous VSD patients were included in this study with 62.5 % female patients (n=20) and 37.5 % male patients (n=12). A significant decrease was observed in the median NT pro BNP level when the level before closure of 1.08 (0.74 – 3.47) ng/ml was compared to the level after closure of 0.91 (0.68 – 2.07) ng/ml (p<0.05). Conclusion: Significant decreases in NT pro BNP level are seen in small VSD patients 30 days after transcatheter closure. Patients with small peri membranous VSD are generally considered to need occlusion for their childhood defect.  


2007 ◽  
Vol 292 (5) ◽  
pp. H2324-H2332 ◽  
Author(s):  
Dirk W. Donker ◽  
Jos G. Maessen ◽  
Fons Verheyen ◽  
Frans C. Ramaekers ◽  
Roel L. H. M. G. Spätjens ◽  
...  

It is poorly understood how mechanical stimuli influence in vivo myocardial remodeling during chronic hemodynamic overload. Combined quantitation of ventricular mechanics and expression of key proteins involved in mechanotransduction can improve fundamental understanding. Adult anesthetized dogs ( n = 20) were studied at sinus rhythm (SR) and 0, 3, 10, and 35 days of complete atrioventricular block (AVB). Serial left ventricular (LV) myofiber mechanics were measured. Repeated LV biopsies were analyzed for mRNA and/or protein expression of β1D-integrin, melusin, Akt, GSK3β, muscle LIM protein (MLP), four-and-a-half LIM protein 2 (fhl2), desmin, and calpain. Upon AVB, increased ejection strain (0.29 ± 0.01 vs. 0.13 ± 0.02, SR) and end-diastolic stress (4.8 ± 1.1 vs. 2.7 ± 0.4 kPa) dominated mechanical changes. Brain natriuretic peptide plasma levels were correspondingly high (33 ± 4 vs. 19 ± 1 pg/ml, SR). β1D-Integrin protein expression increased chronically after AVB. Melusin was temporarily overexpressed (+33 ± 9%, 3 days AVB vs. SR), followed by elevated ratios of phosphorylated (P)-Akt to Akt and P-GSK3β to GSK3β (+26 ± 6% and +30 ± 8% at 10 days AVB vs. SR). These changes corresponded to peak hypertrophic growth at 3 to 10 days. MLP increased gradually to maxima at chronic AVB (+36 ± 7%). In contrast, fhl2 (−22 ± 3%, 3 days) and desmin (−30 ± 9%, 10 days AVB) transiently declined but recovered at chronic AVB. Calpain protein expression remained unaltered. In conclusion, volume overload after AVB causes a transient compromise of cytoskeletal integrity based, at least partly, on transcriptional downregulation. Subsequent cytoskeletal reorganization coincides with the upregulation of melusin, P-Akt, P-GSK3β, and MLP, indicating a strong drive to compensated hypertrophy.


2012 ◽  
Vol 302 (2) ◽  
pp. R292-R299 ◽  
Author(s):  
Fernando L. Martin ◽  
Paul M. McKie ◽  
Alessandro Cataliotti ◽  
S. Jeson Sangaralingham ◽  
Josef Korinek ◽  
...  

Impaired renal function with loss of nephron number in chronic renal disease (CKD) is associated with increased cardiovascular morbidity and mortality. However, the structural and functional cardiac response to early and mild reduction in renal mass is poorly defined. We hypothesized that mild renal impairment produced by unilateral nephrectomy (UNX) would result in early cardiac fibrosis and impaired diastolic function, which would progress to a more global left ventricular (LV) dysfunction. Cardiorenal function and structure were assessed in rats at 4 and 16 wk following UNX or sham operation (Sham); ( n = 10 per group). At 4 wk, blood pressure (BP), aldosterone, glomerular filtration rate (GFR), proteinuria, and plasma B-type natriuretic peptide (BNP) were not altered by UNX, representing a model of mild early CKD. However, UNX was associated with significantly greater LV myocardial fibrosis compared with Sham. Importantly, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining revealed increased apoptosis in the LV myocardium. Further, diastolic dysfunction, assessed by strain echocardiography, but with preserved LVEF, was observed. Changes in genes related to the TGF-β and apoptosis pathways in the LV myocardium were also observed. At 16 wk post-UNX, we observed persistent LV fibrosis and impairment in LV diastolic function. In addition, LV mass significantly increased, as did LVEDd, while there was a reduction in LVEF. Aldosterone, BNP, and proteinuria were increased, while GFR was decreased. The myocardial, structural, and functional alterations were associated with persistent changes in the TGF-β pathway and even more widespread changes in the LV apoptotic pathway. These studies demonstrate that mild renal insufficiency in the rat results in early cardiac fibrosis and impaired diastolic function, which progresses to more global LV remodeling and dysfunction. Thus, these studies importantly advance the concept of a kidney-heart connection in the control of myocardial structure and function.


2021 ◽  
Vol 34 (3) ◽  
pp. 299-299
Author(s):  
Yu Feng ◽  
Man-li Zhou ◽  
Jian-zhang Wang ◽  
Jia-qi Zhang ◽  
Shu-le Qian ◽  
...  

Abstract Background To investigate the effects of telmisartan on the protein profiles of the left ventricular myocardium in spontaneously hypertensive rats (SHR). Methods Sixteen SHR were randomly divided into control and telmisartan treatment groups. Rats were treated with sterile water (10 ml/kg) or telmisartan (4.33 mg/kg) by gavage for 12 weeks. Wistar-Kyoto (WKY) rats treated with sterile water (10 ml/kg) as controls. At the end of 12 weeks of control or telmisartan treatment, rats were sacrificed, and hearts were collected for protein preparations, isotope labeling, and mass spectrometric analysis. Results In total, there were 23 differentially expressed proteins in the left ventricular myocardium between control and telmisartan treatment groups in SHR. Compared with the telmisartan group, the upregulated proteins in the SHR were dual-specificity mitogen-activated protein kinase kinase 3-like, transgelin, and haptoglobin subtype 2. The downregulated proteins in the SHR were as follows: von Willebrand factor (fragment), kininogen 1, small ribonucleoprotein-related protein, fibrinogen beta chain, protein mass 3 (fragment), proteasome 26s, heat shock protein 27-related protein 1, tenascin X, fibronectin subtype 2, transferrin receptor protein, platelets 1, cathepsin L1, complement factor B, isoform CRA_b, fibrinogen isomer, immunoglobulin heavy chain (γ polypeptide), and α 1 antiprotease. Conclusions Telmisartan differentially regulates myocardial protein expression in hypertensive rats including heat shock protein 27, fibrinogen, fibronectin, proteasome 26s and transgelin, as well as proteins in biochemical, metabolic, and signal transduction pathways. These changes in protein expression may contribute to the antihypertrophic effects of telmisartan in hypertension.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yankun Lyu ◽  
Vipin K. Verma ◽  
Younjee Lee ◽  
Iosif Taleb ◽  
Rachit Badolia ◽  
...  

AbstractIt is well established that the aging heart progressively remodels towards a senescent phenotype, but alterations of cellular microstructure and their differences to chronic heart failure (HF) associated remodeling remain ill-defined. Here, we show that the transverse tubular system (t-system) and proteins underlying excitation-contraction coupling in cardiomyocytes are characteristically remodeled with age. We shed light on mechanisms of this remodeling and identified similarities and differences to chronic HF. Using left ventricular myocardium from donors and HF patients with ages between 19 and 75 years, we established a library of 3D reconstructions of the t-system as well as ryanodine receptor (RyR) and junctophilin 2 (JPH2) clusters. Aging was characterized by t-system alterations and sarcolemmal dissociation of RyR clusters. This remodeling was less pronounced than in HF and accompanied by major alterations of JPH2 arrangement. Our study indicates that targeting sarcolemmal association of JPH2 might ameliorate age-associated deficiencies of heart function.


2021 ◽  
Vol 8 (2) ◽  
pp. 9
Author(s):  
Nina C. Wunderlich ◽  
Siew Yen Ho ◽  
Nir Flint ◽  
Robert J. Siegel

The morphological changes that occur in myxomatous mitral valve disease (MMVD) involve various components, ultimately leading to the impairment of mitral valve (MV) function. In this context, intrinsic mitral annular abnormalities are increasingly recognized, such as a mitral annular disjunction (MAD), a specific anatomical abnormality whereby there is a distinct separation between the mitral annulus and the left atrial wall and the basal portion of the posterolateral left ventricular myocardium. In recent years, several studies have suggested that MAD contributes to myxomatous degeneration of the mitral leaflets, and there is growing evidence that MAD is associated with ventricular arrhythmias and sudden cardiac death. In this review, the morphological characteristics of MAD and imaging tools for diagnosis will be described, and the clinical and functional aspects of the coincidence of MAD and myxomatous MVP will be discussed.


2014 ◽  
Vol 112 (11) ◽  
pp. 951-959 ◽  
Author(s):  
Morten Eriksen ◽  
Arnfinn Ilebekk ◽  
Alessandro Cataliotti ◽  
Cathrine Rein Carlson ◽  
Torstein Lyberg ◽  
...  

SummaryBradykinin (BK) receptor-2 (B2R) and β2-adrenergic receptor (β2AR) have been shown to form heterodimers in vitro. However, in vivo proofs of the functional effects of B2R-β2AR heterodimerisation are missing. Both BK and adrenergic stimulation are known inducers of tPA release. Our goal was to demonstrate the existence of B2R-β2AR heterodimerisation in myocardium and to define its functional effect on cardiac release of tPA in vivo. We further investigated the effects of a non-selective β-blocker on this receptor interplay. To investigate functional effects of B2R-β2AR heterodimerisation (i. e. BK transactivation of β2AR) in vivo, we induced serial electrical stimulation of cardiac sympathetic nerves (SS) in normal pigs that underwent concomitant BK infusion. Both SS and BK alone induced increases in cardiac tPA release. Importantly, despite B2R desensitisation, simultaneous BK infusion and SS (BK+SS) was characterised by 2.3 ± 0.3-fold enhanced tPA release compared to SS alone. When β-blockade (propranolol) was introduced prior to BK+SS, tPA release was inhibited. A persistent B2R-β2AR heterodimer was confirmed in BK-stimulated and nonstimulated left ventricular myocardium by immunoprecipitation studies and under non-reducing gel conditions. All together, these results strongly suggest BK transactivation of β2AR leading to enhanced β2AR-mediated release of tPA. Importantly, non-selective β-blockade inhibits both SS-induced release of tPA and the functional effects of B2R-β2AR heterodimerisation in vivo, which may have important clinical implications.


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