bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of BACH1 expression by hemin improves cardiac function and revascularisation in a mouse model of myocardial infarction
Authors: Slater S , Alvino V , Avolio E , Katare R , Madeddu P 
Published: November 2023

Abstract
Therapies to induce mature neovascularization formation and moderate oxidative stress after myocardial infarction (MI) are urgently needed. The BACH1 transcription factor is known as a repressor of genes involved in the antioxidant response (1). We have demonstrated BACH1 can regulate neovascularization through modulation of pro-angiogenic genes, particularly angiopoietin-1 (2).
We hypothesise expression of BACH1 after MI contributes to suppression of genes which promote reparative angiogenesis. We propose treatment with hemin (a therapeutic compound known to degrade BACH1) will prevent BACH1 repression of target genes, leading to increased expression of proangiogenic factors and increased neovascularisation and cardiac repair in a mouse MI model.
MI was induced in 8-week old C57/Bl6 male mice by permanent ligation of the left anterior descending coronary artery, n=10-14. Expression of Bach1 and the antioxidant Hmox1 in heart tissue was determined by Western blot at day 3 and 10 post MI, whilst a second group were randomized to receive vehicle, 12.5, 25 or 50mg/kg hemin intraperitoneally every 3 days until 28 days post-MI. On day 28, following echocardiography, mice were euthanised and ventricular tissue collected for histological analysis. Data was analysed by 2-way ANOVA with post-test multiple comparisons.
Compared to sham mice, Bach1 expression significantly increased at both day 3 and 10 post MI (P&lt;0.0001 and P&lt;0.01 respectively). Bach1 expression at day 10 was significantly lower compared to day 3, suggesting a transient effect (P&lt;0.01). Hmox1 expression was significantly decreased at both timepoints (both P&lt;0.001 vs. sham) suggesting in the initial period after MI the antioxidant and angiogenic responses are suboptimal. Treatment of mice with 25mg/kg hemin for 28 days post MI caused significant increases in capillary and arteriole density in the peri-infarct zone (P&lt;0.0002 and P&lt;0.0008 vs. vehicle respectively). There was no effect on capillary or arteriole density in the remote zone. In vehicle-treated mice there was thinning of the left ventricular end-diastolic anterior wall thickness (LVAW) corresponding to the infarct area. Interestingly, a significant increase in the thickness of the LVAW was observed after 25mg/kg hemin treatment (P&lt;0.0001 vs. vehicle), whilst LV internal diameter significantly decreased (P&lt;0.0001 vs. vehicle). Ejection fraction (P&lt;0.0001), fractional shortening (P&lt;0.0009) and stroke volume (P&lt;0.0001) all significantly increased in mice treated with hemin compared to vehicle.
Treatment of mice with 25mg/kg hemin for 28 days post MI was sufficient to induce significantly increased capillary and arteriole density in the peri-infarct region. We also observed hemin exerted benefits on volumetric and contractility indexes. This data suggests hemin has potential to be used therapeutically post MI to improve revascularisation and cardiac function.
Paracrine cardioprotective signaling by red blood cells through hypoxia-mediated activation of soluble guanylate cyclase and release of cyclic guanosine monophosphate
Authors: Yang J N , Sundqvist M , Zheng X , Jiao T , Collado A , Mahdi A , Tengbom J , Mergia E , Zhou Z , Carlstrom M , Akaike T , Cortese-Krott M , Weitzberg E , Lundberg J O , Pernow J 
Published: November 2023

Abstract

Background
Red blood cells (RBCs) are known to regulate cardiovascular function under hypoxic conditions and to mediate cardioprotection via nitric oxide (NO)-like bioactivity. However, the molecular signalling behind this effect and the identity of any mediator released by the RBCs remain unknown. Previous studies revealed that NO activates soluble guanylate cyclase (sGC) and increases formation of the second messenger cyclic guanosine monophosphate (cGMP) in RBCs. The functional role of this signalling in RBCs during hypoxia/ischemia is still unclear.

Aim
To determine the functional role of the NO-sGC-cGMP signalling pathway in RBCs during hypoxia and myocardial ischemia.

Method
RBCs collected from wild-type and sGC knockout mice were exposed to 1% hypoxia or normoxia for 1 h. The RBCs or the extracellular supernatant were then administered to isolated Langendorff-perfused mouse hearts subjected to 40 min global ischemia and 60 min reperfusion. Afterwards, left ventricular developed pressure and infarct size were determined. Additional groups of mice and patients with mild hypertension were given oral nitrate (10mM in their drinking water) before the collection of RBCs to further increase NO signalling.

Result
Administration of RBCs or the extracellular supernatant collected from wild-type mouse RBCs exposed to hypoxia to isolated hearts subjected to ischemia-reperfusion improved post-ischemic cardiac function and reduced infarct size (Fig. 1A and B). By contrast, supernatant collected from hypoxic RBCs of sGC knockout mice failed to induce cardioprotection (Fig. 1C). The cardioprotection induced by hypoxic RBCs of wild-type mice was blocked by MK571, an inhibitor of cyclic nucleotide transport (Fig. 1D). Hypoxia increased extracellular export of hate cGMP from mouse RBCs (Fig. 1E), and exogenous cGMP resulted in similar cardioprotection induced by the supernatant. The cardioprotective effect of RBCs was blocked by an inhibitor of cardiac cGMP-dependent protein kinase G (PKG) (Fig. 1F) and was associated with increased cardiac PKG-dependent phosphorylation of vasodilator-stimulated phosphoprotein. Oral administration of nitrate to mice for 4 weeks to increase NO bioactivity further enhanced the cardioprotective effect of hypoxic RBCs. RBCs collected from patients randomized to a 5-week nitrate-rich diet induced cardioprotection in the isolated rat heart via an effect dependent on sGC activation in the RBCs (Fig 2).

Conclusion
RBCs generate and export cGMP as a physiological response to hypoxia mediating cardioprotection via a paracrine effect. This effect can be further augmented by a simple dietary intervention with nitrate suggesting preventive and therapeutic opportunities in ischemic heart disease.Figure 1Figure 2
Mitochondrial succinate transport as a novel therapeutic target for cardiac ischemia/reperfusion injury
Authors: Prag H A , Abe J , Pala L , Schanz S , Caldwell S T , Murphy M P , Hartley R C , Krieg T 
Published: November 2023

Abstract

Background
The accumulation of the mitochondrial metabolite succinate during ischemia and its rapid oxidation by succinate dehydrogenase (SDH) upon reperfusion drives ischemia/reperfusion injury (IRI) in myocardial infarction. Succinate oxidation leads to the production of reactive oxygen species (ROS) by reverse electron transport (RET) at mitochondrial complex I, orchestrating a cascade of events leading to cardiomyocyte death. Modulating succinate metabolism, such as SDH inhibition, is a promising therapeutic strategy. During ischemia, the mitochondria produced succinate is transported into the cytosol, enabling the accumulation of a large succinate pool. On reperfusion, the succinate is transported back into mitochondria and oxidised by SDH, thus we hypothesised that targeting succinate mitochondrial transport could be a novel therapeutic target to prevent cardiac IRI.

Purpose
To assess the role of succinate mitochondrial transport as a novel therapeutic target to prevent cardiac IRI.

Methods
Isolated heart mitochondria were used to assess mitochondrial respiration by Oroboros, RET-ROS production by Amplex Red and butylmalonate delivery. Cultured H9C2 myoblasts and isolated primary adult cardiomyocytes from C57BL/6J mice were used to assess butylmalonate uptake and delivery from esters, as well as their impact on succinate accumulation and oxidation in vitro. LAD ligation and reperfusion in C57BL/6J mice was used as an in vivo MI model. Metabolite levels were measured by LC-MS/MS.

Results
Butylmalonate, an inhibitor of the mitochondrial dicarboxylate carrier (DIC), blocks succinate-dependent respiration and RET-ROS production in isolated mitochondria. However, butylmalonate entry into cells was inefficient and does not impact infarct size after IRI in vivo. We developed novel butylmalonate esters to improve butylmalonate delivery to cardiomyocytes in vivo. We found that diacetoxymethyl butylmalonate (DAB) effectively delivered butylmalonate and could prevent succinate accumulation and oxidation in vitro. DAB could also prevent succinate-mediated respiration and RET-ROS at lower concentrations than butylmalonate alone. Finally, DAB reduced acute infarct size in vivo when administered at reperfusion.

Conclusions
Blocking succinate transport back into mitochondria at reperfusion prevents the damage in IRI by preventing the oxidation of succinate by SDH and downstream RET-ROS production. Therefore, targeting the mitochondrial transport of succinate may be a promising novel strategy in preventing cardiac IRI.
The prolyl-hydroxylase inhibitior Roxadustat upregulates HIF-1alpha and is associated with improved cardiac repair after myocardial infarction in mice
Authors: Staggl S , Messner M , Ghadge S K , Maurer T , Wimmer A , Seiringer H , Poelzl G , Bauer A , Zaruba M M 
Published: November 2023

Abstract

Introduction
Activation of the CXCL12/CXCR4-axis is known to aid myocardial repair by attraction of reparative CXCR4+ cells through ischemia triggered hypoxia-inducible factor-1α (HIF-1α) activation of CXCL12 (1). To prolongate upregulation of CXCL12 we aimed to stabilize HIF-1α by administration of Roxadustat, the only prolyl hydroxylase inhibitor (PHI) clinically approved by the EMA with the purpose to augment myocardial remodelling and improve LV function.

Methods
To analyse the effects of HIF-1α mediated CXCL12 upregulation in vivo (BM & heart), optimal doses (50mg/kg i.p., every 72h) of the PHI Roxadusat (FG-4592) were administered to Bl6/J mice. CXCL12 and CXCR4 expression was analysed in-vitro in human umbilical vascular endothelial cells (HUVEC) after administration of FG-4592 (20µM to 1000µM) at different time points (1 to 24 hrs). Western Blots were performed and effects on HIF-1α -signalling were quantified by densitometry. We induced MI in BL6/J mice at the age of 8-10 weeks by LAD-ligation. Two groups (n=10) were treated with Roxadustat or saline for 28 days before assessment of cardiac function by echocardiography and evaluation by histology. Two other groups of n=5 mice were treated with Roxadustat or saline for one week and analysed regarding apoptotic-index by automated cell count in DAPI & Tunel stained sections.

Results
We were able to show a significant upregulation of HIF-1α after exposure of 50-500 μM Roxadustat for 4-24 hours in-vitro (HUVEC) and in-vivo (murine BL6/J hearts). Moreover, administration of 500 µM Roxadustat induced marked activation of CXCR4 and CXCL12, respectively. Infarct size (19.07%±7.86 vs. 24.14%±12,05; n= 10/8; p = 0.297), as well as LV-wall thickness in the infarcted myocardium (788.27µm±240.10 vs. 651.40µm±231.47; n=10/8; p = 0.240) revealed no significant differences 28 days after MI. Automated cell counting in the borderzone revealed a lowered apoptotic-index of Roxadustat treated animals (3.7%±1.1 vs. 6.3%±2.3; p = 0.071). Echocardiographic analyses showed a significantly preserved ejection fraction (EF) (46.1%±6.0 vs. 30.5%±9.3; n=10/9; p&lt;0.001), reduced diastolic (4.18±0.32 vs. 4.77±0.40; p=0.002) and systolic (3.23±0.31 vs. 3.95±0.43; p&lt;0.001) LV diameters in Roxadustat treated mice 28 days after MI compared to saline treated controls.

Conclusion
The clinically approved PHI Roxadustat revealed increased expression of HIF-1α associated with upregulation of CXCR4 and CXCL12. Administration of Roxadustat after MI revealed attenuated infarct remodelling and functional improvement showing its potential in ischemic heart disease.
The clinically active PARP inhibitor olaparib ameliorates doxorubicin-induced cardiotoxicity in both in vitro and in vivo model
Authors: Chen D , Croft A , Haw T J , Kelly C , Leong A , Sverdlov A , Ngo D 
Published: November 2023

Abstract

Introduction
Inhibition of poly (ADP-ribose) polymerase (PARP) has been shown to be cardioprotective in acute and chronic myocardial injury. Additionally, PARP inhibitor, Olaparib, is a clinically effective anti-cancer agent. Activation of PARP pathway has been suggested to be involved in cardiotoxicity arising from Doxorubicin (DOX, one of the most used anticancer drugs). It is thus, entirely possible that PARP inhibition could be a novel pathway to prevent DOX-induced cardiotoxicity (DIC).

Purpose
To determine the cardioprotective effects of Olaparib in preventing DOX-induced cardiotoxicity in in vitro and in vivo models.

Methods
In vitro: Human cardiomyocytes (HCMs) were treated with DOX at 1uM (EC50) +/- various doses (15.6nM, 1uM, 80uM, 100uM and 150uM) of Olaparib at 72hrs. Cell viability was assessed via CellTiter-Glo®. The mRNA expressions of treated HCMs were performed by qPCR. In vivo: Female C57BL/6 mice (6-8 weeks old) were administered: A) DOX at 5mg/kg/week for 6 weeks via IP injections, B) vehicle of 0.9% saline and 5% DMSO in PBS, C) Olaparib at 50mg/kg was administered 3 times/week, D) Olaparib at 50mg/kg was administered 3 times/week, followed by DOX treatments. Cardiac function was assessed by echocardiography at baseline and end of 6 weeks’ treatment.

Results
For the in vitro model, Doxorubicin induced marked reduction in HCMs cell viability. Concomitant Olaparib treatment at higher doses (80uM, 100uM, 150uM) significantly preserved DOX-induced cell viability after 72 hours of treatment. Molecular analysis in HCMs showed DOX-induced upregulation of mRNA gene expressions for apoptosis: Casp3, DNA damage: BBC3, and cardiac remodelling: TGF-β; all of which were reversed by Olaparib. In vivo: we found significant reduction of left ventricular function and increased ventricular wall thickness in DOX treated group after 6 weeks’ treatment compare to baseline [LVEF%: 52.4±1.3 vs.56.5±2.0, P=0.02; FS%:16.7±1.4 vs. 20.1±1.3, P=0.03; Total Wall thickness (mm):2.1±0.1 vs. 1.9±0.1, P&lt;0.05]; whereas the mice pre-treated with Olaparib in combination with DOX showed preservation of cardiac functions between endpoint and baseline.

Conclusion
Olaparib protected HCMs against DIC and improved cardiac function in DIC mice model. Our findings indicate that Olaparib could provide cardioprotection in DOX-induced cardiotoxicity.
The effect of cardiosphere-derived cell extracellular vesicles embedded in cardiac matrix hydrogel on cardiac remodeling in a porcine model of ischemic cardiomyopathy
Authors: Casado Mayo L , Canadilla V , Aguirre Acosta A , Gomez-Cid L , Sanz R , Ocampo A , Crisostomo V , Fernandez-Santos M E , Gonzalez Mansilla A , Bermejo J , Fernandez-Aviles F , Grigorian L 
Published: November 2023

Abstract

Background
Numerous preclinical studies have confirmed that stem cell-derived extracellular vesicles (EVs) can prevent from negative cardiac remodeling after an ischemic injury, reduce the scar and preserve heart function. It is believed that by increasing the engraftment of the therapeutic product at the target site may bust its efficacy. The use of bioengineering materials such as hydrogels as delivery scaffolds for intramyocardial EVs administration may constitute a minimally invasive therapeutic strategy that improves the efficacy of EVs by increasing their permanence in the tissue.

Objective
To evaluate the therapeutic efficacy of a new regenerative product constituted by the combination of EVs secreted by cardiosphere-derived cell (CDC-EVs) embedded in a hydrogel-based scaffold made from decellularized cardiac matrix (HDM).

Methods
Twelve pigs (50% females) with induced ischemic cardiomyopathy were randomly assigned to receive: phosphate-buffer saline (PBS) as control group (n=4), CDC-EVs alone (n=4) and combination of CDC-EVs and HDM (EV-HDM, n=4). Treatment was administered via percutaneous intramyocardial injection in the scar border zone 1-month after myocardial infarction with NOGA system. Animals were followed-up another month and sacrificed. Hearts were excised for histological analysis performed according to the cardiac area: scar (anterior wall), scar border zone and remote zone (inferior wall). Functional evaluation was performed with cardiac magnetic resonance imaging immediately before- and 1-month after treatment.

Results
Cardiomyocytes size was significantly lower in EV-HDM group compared to control PBS both at scar border (4660± 2088 vs. 5254±2294 pixels; p=0.02) and remote areas (3381±1259 vs. 4237±1256 pixels; p&lt;0.001), while no changes were observed in CDC-EV alone group compared to controls. Interstitial fibrosis was significantly lower in EV-HDM group compared to PBS controls both at scar epicardial side (34% vs. 44%; p=0.01) and remote areas (16% vs. 20%; p&lt;0.01), similarly to CDC-EV vs. PBS (34% at the scar; p&lt;0.01 and 17% at the remote zone; p=0.01). While left ventricular ejection fraction (LVEF) tended to decrease in PBS group from 36% to 32%, it showed an opposite trend in CDC-EV (from 35 % to 38%) and EV-HDM (from 31% to 37%).

Conclusion
The combined product of EV-HDM reduce cardiac fibrosis and hypertrophy, favorably affecting the remodeling process and may thus increase LVEF in ischemic heart disease. The results of our study fail to clearly demonstrate the superiority of EV-HDM over CDC-EVs alone, although it may exist.
TCF21 gene and cardiovascular events in a coronary population
Authors: Sa D , Mendonca M I , Santos M , Temtem M , Sousa F , Henriques E , Borges S , Freitas S , Rodrigues M , Guerra G , Drumond A , Sousa A C , Palma Dos Reis R 
Published: November 2023

Abstract

Background
Recent research showed that TCF21 expression in precursor cells that migrate into the disease lesions contributes to the fibrous cap, stabilizing the lesions and preventing heart attacks. Targeted deletion of the transcription factor encoded by the TCF21 was associated with vascular smooth muscle cell disruption impairing the fibrous cap structure, increasing cardiovascular(CV) disease risk. Its association with CV events is unknown.

Purpose
Analyze the TCF21 rs12190287 variant G&gt;C evaluating its association with atherosclerosis severity and the appearance of cardiovascular (CV) events.

Methods
We performed a prospective study with 1,716 coronary artery disease (CAD) patients (mean age 53.3±7.8 years). TCF21 rs12190287 G&gt;C was genotyped by TaqMan genotyping assay (Applied Biosystems) in all patients. The severity of CAD was graded according to the number of obstructed coronary arteries with at least 70% narrowed lumen. Chi-squared tests were used to determine differences in CAD severity by genotype. We performed a first multivariate logistic regression analysis to assess the independent risk variables associated with CAD severity. After that, we presented a second multivariate Cox regression to evaluate independent variables related to CV events. Kaplan Meier estimated the survival curves.

Results
48.0% of the CC genotype carriers were associated with more than two obstructed coronary arteries compared to the GG wild genotype, which was associated with only 9.2% (p=0.002). Multivariate analysis (logistic regression) showed that the CC genotype had a high risk of CAD severity (OR=2.95; p=0.001) than GG. After Cox regression analysis, which takes into account the time to the first event, the CC genotype remained in the equation with an HR of 1.38; 95%CI 1.02-1.88; p=0.040. The survival events free at ten years is 49.1% in the CAD patients with the GG genotype, then drops to 39.6 % with the CC risk genotype.

Conclusion
This work shows that the GG wild genotype protects against CAD severity. In contrast, the CC genotype is associated with an increased risk of CAD severity. The patients with this allelic variant had a worse survival event free. Future research with the implementation of epigenetic and genetic therapeutics targeted to deleterious genes will allow the eradication of coronary heart disease worldwide.
Diastolic dysfunction is associated with cardiac small vessel disease in ovariectomized females but not in males
Authors: Cornuault L , Grouthier V , Rouault P , Bourguignon C , Foussard N , Chapouly C , Gadeau A P , Couffinhal T , Renault M A 
Published: November 2023

Abstract

Introduction
Coronary microvascular disease has been proposed to be responsible for heart failure with preserved ejection fraction (HFpEF) about 10 years ago. However, to date the role and phenotype of the coronary microvasculature has still been poorly considered and investigated in animal models of HFpEF.

Objective
To characterize the phenotype of the coronary microvasculature in male and female mice with diastolic dysfunction.

Method
We assessed cardiac function and characterized the coronary microvasculature in two mouse models of HFpEF: mice fed with a high fat diet (HFD) + L-NAME regimen and Leptin receptor deficient (Leprdb/db) mice. Notably, our study was done in males, females and ovariectomized (OVX) female mice in order to search for possible sexual dimorphisms.

Results
Upon a HFD + L-NAME regimen, both males and OVX females but not non OVX females develop diastolic dysfunction attested by an increased end diastolic pressure. In Leprdb/db mice, both Male and non OVX female mice develop diastolic dysfunction. Notably female mice have reduced estradiol and progesterone level mice mimicking ovariectomy.
We found that both OVX and non OVX females but not males display increased endothelial activation attested by increased ICAM1 expression, endothelium leakage attested by increased Fibrinogen and IgG extravasation and decreased arteriole diameter suggesting vasoconstriction. The same results were found in Leprdb/db mice.
Conclusion: Diastolic dysfunction is not always associated with cardiac small vessel disease since Leprdb/db males and C57BL/6J males fed with a high fat diet (HFD) + L-NAME regimen develop diastolic dysfunction in the absence of endothelial dysfunction. Also endothelial dysfunction may not be sufficient to induce diastolic dysfunction since non OVX female mice fed with a high fat diet (HFD) + L-NAME regimen display endothelial dysfunction while they do not develop diastolic dysfunction.