scholarly journals Comparison of Repeated Doses of C-kit-Positive Cardiac Cells versus a Single Equivalent Combined Dose in a Murine Model of Chronic Ischemic Cardiomyopathy

2021 ◽  
Vol 22 (6) ◽  
pp. 3145
Author(s):  
Qianhong Li ◽  
Yiru Guo ◽  
Yibing Nong ◽  
Alex Tomlin ◽  
Anna Gumpert ◽  
...  

Using a murine model of chronic ischemic cardiomyopathy caused by an old myocardial infarction (MI), we have previously found that three doses of 1 × 106 c-kit positive cardiac cells (CPCs) are more effective than a single dose of 1 × 106 cells. The goal of this study was to determine whether the beneficial effects of three doses of CPCs (1 × 106 cells each) can be fully replicated by a single combined dose of 3 × 106 CPCs. Mice underwent a 60-min coronary occlusion; after 90 days of reperfusion, they received three echo-guided intraventricular infusions at 5-week intervals: (1) vehicle × 3; (2) one combined dose of CPCs (3 × 106) and vehicle × 2; or (3) three doses of CPCs (1 × 106 each). In the combined-dose group, left ventricular ejection fraction (LVEF) improved after the 1st CPC infusion, but not after the 2nd and 3rd (vehicle) infusions. In contrast, in the multiple-dose group, LVEF increased after each CPC infusion; at the final echo, LVEF averaged 35.2 ± 0.6% (p < 0.001 vs. the vehicle group, 27.3 ± 0.2%). At the end of the study, the total cumulative change in EF from pretreatment values was numerically greater in the multiple-dose group (6.6 ± 0.6%) than in the combined-dose group (4.8 ± 0.8%), although the difference was not statistically significant (p = 0.08). Hemodynamic studies showed that several parameters of LV function in the multiple-dose group were numerically greater than in the combined-dose group (p = 0.08 for the difference in LVEF). Compared with vehicle, cardiomyocyte cross-sectional area was reduced only in the multiple-dose group (−32.7%, 182.6 ± 15.1 µm2 vs. 271.5 ± 27.2 µm2, p < 0.05, in the risk region and −28.5%, 148.5 ± 12.1 µm2 vs. 207.6 ± 20.5 µm2, p < 0.05, in the noninfarcted region). LV weight/body weight ratio and LV weight/tibia length ratios were significantly reduced in both cell treated groups vs. the vehicle group, indicating the attenuation of LV hypertrophy; however, the lung weight/body weight ratio was significantly reduced only in the multiple-dose group, suggesting decreased pulmonary congestion. Taken together, these results indicate that in mice with chronic ischemic cardiomyopathy, the beneficial effects of three doses of CPCs on LV function and hypertrophy cannot be fully replicated with a single dose, notwithstanding the fact that the total number of cells delivered with one or three doses is the same. Thus, it is the multiplicity of doses, and not the total number of cells, that accounts for the superiority of the repeated-dose paradigm. This study supports the idea that the efficacy of cell therapy in heart failure can be augmented by repeated administrations.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Qianhong Li ◽  
Ning Chen ◽  
Li Luo ◽  
Qinghui Ou ◽  
Wei Xie ◽  
...  

Background: We have previously shown in rats that the beneficial effects of c-kit + CSCs on LV function and remodeling post-myocardial infarction persist for at least 1 year after CSC administration. However, in that study the retention of transplanted Y-chromosome + cells in the risk region (RR) of female rat hearts at 1 year was low (<10% of total nuclei) and not sufficient to account for the functional improvement, suggesting that other mechanisms must be at work. Methods and Results: To address this issue, rats received intracoronary vehicle or 1x10 6 syngeneic CSCs 4 h after a 90-min coronary occlusion; 11 months later, BrdU treatment was given for 1 month. CSCs, which are c-kit + /CD45 − , were distinguished from c-kit + hematopoietic stem cells/mast cells, which are CD45 + . At 1 year after CSC administration, the total number of c-kit + or c-kit + /BrdU + cells in the heart (the sum of c-kit + /CD45 − and c-kit + /CD45 + cells) did not differ between CSC and control groups (Figs. H and I). However, CSC transplantation resulted in increased numbers of CSCs (c-kit + /CD45 − cells) in the RR (i.e., the infarct zone plus border zone)(47.6±7.0% of total c-kit + cells vs. 27.9±4.1% in vehicle group; n=5, P <0.05; Fig. J). Among CSCs (c-kit + /CD45 − cells), the fraction that was newly formed (c-kit + /CD45 − /BrdU + ) was dramatically increased in the RR of the CSC group (+ 2.6-fold vs. vehicle group; n=4, P <0.05; Fig. M), indicating increased CSC proliferation and turnover. Conclusions: These data reveal, for the first time, that a single intracoronary infusion of CSCs is followed by an increase in both the proliferation and the total number of c-kit + CSCs in the myocardium that persists, surprisingly, for at least 1 year after cell delivery. Since transplanted cells do not differentiate into adult myocytes, these data suggest that the long-term salubrious effects of CSCs on cardiac function are mediated by sustained activation of the CSC pool in the heart.


Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 683-684
Author(s):  
Jorge P van Kats ◽  
David W Silversides ◽  
Timothy L Reudelhuber

33 Cardiac angiotensin II (Ang II), either derived from the circulation or locally synthesized, is often suggested to be involved in the structural adaptations occurring in the heart in hypertension and following myocardial infarction. However, it is debated whether the proven beneficial effects of renin-angiotensin system blockade in these pathologies are related to an inhibition of the direct cardiac actions of the peptide. The objective of the present study was to investigate which of the effects of cardiac Ang II are due to direct stimulation of cardiac cells by Ang II. To test for cardiac specific functions of Ang II, transgenic mice were developed that express an Ang II-releasing fusion protein (J Biol Chem 1997;272:12994-99) exclusively in cardiomyocytes. Blood pressure, heart rate, cardiac and plasma Ang II content, Ang II receptor binding and organ morphology were monitored in transgenic (TG) and non-transgenic littermate mice (control). Cardiac Ang II levels in TG mice were 20-40 fold higher than in hearts of control mice (15±3 pg/100 mg ww). In 3 independent founder lines of TG mice, plasma Ang II concentration was not altered as compared to control (119±20 vs. 127±20 pg/mL). The heart weight to body weight ratio in TG mice (4.0±0.1 mg/g) was not different from controls (3.8±0.1 mg/g), neither was systolic pressure (137±4 and 138±7 mm Hg respectively) or heart rate (618±13 and 662±15 bpm respectively). Microscopic inspection of TG hearts did not reveal any differences with control regarding size and number of cardiomyocytes and organization of extracellular matrix proteins. TG mice had not become less sensitive for Ang II signaling since Ang II receptor number was not altered in TG mice (Bmax = 23±3 fmol/mg protein) as compared to control (22±2 fmol/mg protein). Our data show that very high Ang II levels in hearts of TG mice do not lead to myocardial enlargement or affect cardiovascular physiology. We conclude that elevated Ang II in the heart has no direct effects on cardiac cells and we hypothesize that effects of cardiac Ang II become apparent upon altered hemodynamic loading.


2010 ◽  
Vol 299 (5) ◽  
pp. H1348-H1356 ◽  
Author(s):  
Craig A. Emter ◽  
Christopher P. Baines

Cardiac hypertrophy in response to hypertension or myocardial infarction is a pathological indicator associated with heart failure (HF). A central component of the remodeling process is the loss of cardiomyocytes via cell death pathways regulated by the mitochondrion. Recent evidence has indicated that exercise training can attenuate or reverse pathological remodeling, creating a physiological phenotype. The purpose of this study was to examine left ventricular (LV) function, remodeling, and cardiomyocyte mitochondrial function in aortic-banded (AB) sedentary (HFSED; n = 6), AB exercise-trained (HFTR, n = 5), and control sedentary ( n = 5) male Yucatan miniature swine. LV hypertrophy was present in both AB groups before the start of training, as indicated by increases in LV end-diastolic volume, LV end-systolic volume (LVESV), and LV end-systolic dimension (LVESD). Exercise training (15 wk) prevented further increases in LVESV and LVESD ( P < 0.05). The heart weight-to-body weight ratio, LV + septum-to-body weight ratio, LV + septum-to-right ventricle ratio, and cardiomyocyte cross-sectional area were increased in both AB groups postmortem regardless of training status. Preservation of LV function after exercise training, as indicated by the maintenance of fractional shortening, ejection fraction, and mean wall shortening and increased stroke volume, was associated with an attenuation of the increased LV fibrosis (23%) and collagen (36%) observed in HFSED animals. LV mitochondrial dysfunction, as measured by Ca2+-induced mitochondrial permeability transition, was increased in HFSED ( P < 0.05) but not HFTR animals. In conclusion, low-intensity interval exercise training preserved LV function as exemplified by an attenuation of fibrosis, maintenance of a positive inotropic state, and inhibition of mitochondrial dysfunction, providing further evidence of the therapeutic potential of exercise in a clinical setting.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
M A Siraj ◽  
A Momen ◽  
D Zarrin Khat ◽  
M Husain

Abstract Background Glucagon-like peptide-1 (GLP-1), its metabolites and related drugs have demonstrated cardioprotective benefits in several animal models of cardiovascular disease (CVD) and select clinical trials. Indeed, large cardiovascular outcome trials (CVOT) of GLP-1 analogs showed significant reductions in major adverse cardiovascular events (MACE). However, smaller studies in patients with heart failure (HF) (e.g. FIGHT), and secondary analyses of some CVOT (e.g. LEADER), have suggested that the cardiovascular benefits of GLP-1 analogs may be muted in select patients. Speculating on how this may be due to undesirable increases in heart rate caused by activation of sinoatrial GLP-1 receptors (Glp1r), we have explored the Glp1r-independent cardioprotective actions of GLP-1(28–36), a neutral endopeptidase (NEP)-derived metabolite of GLP-1. We have shown that the cardioprotective effects of GLP-1(28–36) are mediated by mitochondrial trifunctional protein-α (MTPα)-dependent metabolic shift from fatty acid- to glucose oxidation in coronary vascular cells. As metabolic perturbations are believed to contribute to the pathophysiology of HF, we hypothesized that treatment with GLP-1(28–36) may have beneficial effects on this condition. Purpose To evaluate if treatment with GLP-1(28–36) can prevent onset of HF and/or reverse established HF in a post-MI mouse model. Methods and results Permanent LAD ligation was performed in 10–12wk old male C57BL/6J wild-type mice (wt). Immediately post-MI, mice were assigned to receive either GLP-1(28–36) or scrambled peptide [Scram(28–36)] at 18.5nmol/kg/d (N=30/group) subcutaneously (s.c.) via osmotic mini-pumps for 4wk. Although, treatment with GLP-1(28–36) did not improve post-MI survival, triphenyltetrazolium chloride (TTC)-stained hearts 28d post-MI reveal smaller infarct size in GLP-1(28–36)- vs. Scram(28–36)-treated mice (35.3±1.9% vs. 41.2±1.7%, N=12–15/group, P<0.05). Echocardiography at 28d post-MI showed improved LVEF in mice treated with GLP-1(2–36) (30.1±2.3% vs. 24.2±3.7%, N=12–15/group, P<0.05). Similarly, treatment with GLP-1(28–36) reduced heart/body weight ratio (7.9±0.3 vs. 8.8±0.4 mg/g, N=12–15/group, P<0.05). Next, we tested if GLP-1(28–36) might reverse ischemic HF in this model. After permanent LAD ligation of 10–12wk old male wt mice, only those with echocardiography-defined LVEF between 20–35% at 28d post-MI were randomized to treatment with GLP-1(28–36) or Scram(28–36) [18.5nmol/kg/d (N=15/group)] via s.c. mini-pumps for 4wk. Echocardiography at 56d post-MI (i.e. 28d post-treatment start) revealed that GLP-1(28–36) preserved LV function with no deterioration in LVEF vs. Scram(28–36)-treated controls [−3.1±4.9% vs. −22.8±4%, relative change, N=15/group, P<0.001]. Conclusion In a post-MI mouse model of HF, treatment with GLP-1(28–36) prevents progression to HF, and preserves LV function after the development of established HF. Acknowledgement/Funding This study was funded by a Fellowship from Ted Rogers Centre for Heart Research and a Project Grant from Heart and Stroke Foundation, Canada


Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  

Inbreeding is reduced and genetic diversity enhanced when a small isolated inbred population is crossed to another unrelated population. Crossing can have beneficial or harmful effects on fitness, but beneficial effects predominate, and the risks of harmful ones (outbreeding depression) can be predicted and avoided. For crosses with a low risk of outbreeding depression, there are large and consistent benefits on fitness that persist across generations in outbreeding species. Benefits are greater in species that naturally outbreed than those that inbreed, and increase with the difference in inbreeding coefficient between crossed and inbred populations in mothers and zygotes. However, benefits are similar across invertebrates, vertebrates and plants. There are also important benefits for evolutionary potential of crossing between populations.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Riva ◽  
A Camporeale ◽  
F Sturla ◽  
S Pica ◽  
L Tondi ◽  
...  

Abstract Background Ischemic cardiomyopathy (ICM) is often associated with negative LV remodelling after myocardial infarction, sometimes resulting in impaired LV function and dilation (iDCM). 4D Flow CMR has been recently exploited to assess intracardiac hemodynamic changes in presence of LV remodelling. Purpose To quantify 4D Flow intracardiac kinetic energy (KE) and viscous energy loss (EL) and investigate their relation with LV dysfunction and remodelling. Methods Patients with prior anterior myocardial infarction underwent a CMR study with 4D Flow sequences acquisition; they were divided into ICM (n=10) and iDCM (n=10, EDV&gt;208 ml and EF&lt;40%). 10 controls were used for comparison. LV was semi-automatically segmented using short axis CMR stacks and co-registered with 4D Flow. Global KE and EL were computed over the cardiac cycle. NT-proBNP measurements were correlated with average and peak values, during systole and diastole. Results Both LV volume and EF significantly differ (P&lt;0.0001) between iDCM (EDV=294±56 ml, EF=24±8%), ICM (EDV=181±32 ml, EF=34±6%) and controls (EDV=124±29 ml, EF=72±5%). If compared to controls, both ICM and iDCM showed significantly lower KE (P≤0.0008); though lower than controls, EL was higher in iDCM than ICM. Within the iDCM subgroup, diastolic mean KE and peak EL reported good inverse correlation with NT-proBNP (r=−0.75 and r=−0.69, respectively). EL indexed (ELI) to average KE during systole was higher in the entire ischemic group as compared to controls (ELI(ischemic) = 0.17 vs. ELI(controls) = 0.10, P=0.0054). Conclusions 4D Flow analyses effectively mapped post-ischemic LV energetic changes, highlighting the disproportionate intraventricular EL relative to produced KE; preliminary good correlation between LV energetic changes and NT-proBNP will deserve further investigation in order to contribute to early detection of heart failure. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Italian Ministry of Health


Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 41
Author(s):  
Nouf Aljobaily ◽  
Michael J. Viereckl ◽  
David S. Hydock ◽  
Hend Aljobaily ◽  
Tsung-Yen Wu ◽  
...  

Background: Treatment with the chemotherapy drug doxorubicin (DOX) may lead to toxicities that affect non-cancer cells including the liver. Supplementing the diet with creatine (Cr) has been suggested as a potential intervention to minimize DOX-induced side effects, but its effect in alleviating DOX-induced hepatoxicity is currently unknown. Therefore, we aimed to examine the effects of Cr supplementation on DOX-induced liver damage. Methods: Male Sprague-Dawley rats were fed a diet supplemented with 2% Cr for four weeks, 4% Cr for one week followed by 2% Cr for three more weeks, or control diet for four weeks. Animals then received either a bolus i.p. injection of DOX (15 mg/kg) or saline as a placebo. Animals were then sacrificed five days-post injection and markers of hepatoxicity were analyzed using the liver-to-body weight ratio, aspartate transaminase (AST)-to- alanine aminotransferase (ALT) ratio, alkaline phosphatase (ALP), lipemia, and T-Bilirubin. In addition, hematoxylin and eosin (H&E) staining, Picro-Sirius Red staining, and immunofluorescence staining for CD45, 8-OHdG, and β-galactosidase were performed to evaluate liver morphology, fibrosis, inflammation, oxidative stress, and cellular senescence, respectively. The mRNA levels for biomarkers of liver fibrosis, inflammation, oxidative stress, and senescence-related genes were measured in liver tissues. Chromosomal stability was evaluated using global DNA methylation ELISA. Results: The ALT/AST ratio and liver to body weight ratio tended to increase in the DOX group, and Cr supplementation tended to attenuate this increase. Furthermore, elevated levels of liver fibrosis, inflammation, oxidative stress, and senescence were observed with DOX treatment, and Cr supplementation prior to DOX treatment ameliorated this hepatoxicity. Moreover, DOX treatment resulted in chromosomal instability (i.e., altered DNA methylation profile), and Cr supplementation showed a tendency to restore chromosomal stability with DOX treatment. Conclusion: The data suggest that Cr protected against DOX-induced hepatotoxicity by attenuating fibrosis, inflammation, oxidative stress, and senescence.


Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 743
Author(s):  
Chao Yu Hsu ◽  
Yi Sheng Lin ◽  
Wei Chun Weng ◽  
Lauren Panny ◽  
Hsiang Lai Chen ◽  
...  

The inflammatory process is proposed to be one of the factors to benign prostatic enlargement (BPH), and this is the first study examining the anti-inflammatory ability of phloretin in treating rats with testosterone-induced BPH. BPH would be induced by testosterone (10 mg/kg/day testosterone subcutaneously for 28 days), and the other groups of rats were treated with phloretin 50 mg/kg/day or 100 mg/kg/day orally (phr50 or phr100 group) after induction. Prostate weight and prostate weight to body weight ratio were significantly reduced in the Phr100 group. Reduced dihydrotestosterone without interfering with 5α-reductase was observed in the phr100 group. In inflammatory proteins, reduced IL-6, IL-8, IL-17, NF-κB, and COX-2 were seen in the phr100 group. In reactive oxygen species, malondialdehyde was reduced, and superoxide dismutase and glutathione peroxidase were elevated in the phr100 group. In apoptotic assessment, elevated cleaved caspase-3 was observed in rats of the phr100 group. Enhanced pro-apoptotic Bax and reduced anti-apoptotic Bc1-2 could be seen in the phr100 group. In histological stains, markedly decreased glandular hyperplasia and proliferative cell nuclear antigen were observed with reduced expression in the phr100 group. Meanwhile, positive cells of terminal deoxynucleotidyl transferase dUTP nick end labeling were increased in the phr100 group. In conclusion, the treatment of phloretin 100 mg/kg/day could ameliorate testosterone-induced BPH.


2021 ◽  
Vol 22 (4) ◽  
pp. 1824
Author(s):  
Matthias Mietsch ◽  
Rabea Hinkel

With cardiovascular diseases affecting millions of patients, new treatment strategies are urgently needed. The use of stem cell based approaches has been investigated during the last decades and promising effects have been achieved. However, the beneficial effect of stem cells has been found to being partly due to paracrine functions by alterations of their microenvironment and so an interesting field of research, the “stem- less” approaches has emerged over the last years using or altering the microenvironment, for example, via deletion of senescent cells, application of micro RNAs or by modifying the cellular energy metabolism via targeting mitochondria. Using autologous muscle-derived mitochondria for transplantations into the affected tissues has resulted in promising reports of improvements of cardiac functions in vitro and in vivo. However, since the targeted treatment group represents mainly elderly or otherwise sick patients, it is unclear whether and to what extent autologous mitochondria would exert their beneficial effects in these cases. Stem cells might represent better sources for mitochondria and could enhance the effect of mitochondrial transplantations. Therefore in this review we aim to provide an overview on aging effects of stem cells and mitochondria which might be important for mitochondrial transplantation and to give an overview on the current state in this field together with considerations worthwhile for further investigations.


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