bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of postmenopausal osteoporosis on aortic valve stenosis in an animal model
Authors: Billig H , Schmitt J , Singer L , Schildberg F , Goody P R , Vogel W , Perner S , Nickenig G , Zimmer S
Published: November 2023

Background

Aortic valve stenosis (AVS) is the most prevalent heart valve disease worldwide and mainly affects the elderly. In observational clinical studies, postmenopausal osteoporosis, which affects 30 % of all women, is associated with increased aortic valve calcification and stenosis. However, there are no pathomechanistic investigations that link these diseases.

In this study, we analyzed the impact of postmenopausal osteoporosis in ovariectomized C57BL6/J mice on the occurrence and progression of wire injury-induced aortic valve stenosis.

Methods

To induce postmenopausal osteoporosis, we performed bilateral ovariectomy (OVX) or sham operation in C57BL6/J mice. Successful OVX was confirmed by measuring the uterine weight. To distinguish the impact of estrogen deprivation from osteoporosis effects, 100 µg of the bisphosphonate zoledronic acid (ZA) or vehicle were applied i.p. weekly. Bone density was assessed through histological and µCT-analysis of the distal femur.

14 days after ovariectomy, AVS (or sham-procedure) was induced through a standardized, echocardiography-controlled injury of the aortic valve with a spring wire. Primary endpoint was the increase of peak velocity 2, 4 and 6 weeks after AVS-procedure. 8 weeks after OVX, mice were sacrificed and organs were harvested for further analysis (Fig. 1A).

Results

Bone mineral density and relative bone volume was significantly reduced 8 weeks after OVX. ZA led to a significant increase in bone mineral density, trabecular thickness and relative bone volume in comparison to the sham/vehicle and OVX/vehicle-groups (Fig. 1B-C).

AVS was successfully induced, as shown by a significant increase in peak velocity (PV; Fig. 2A-B) 2, 4 and 6 weeks after wire injury.

PV and mean pressure gradient (MPG) showed no difference between OVX- or Sham-operated mice (Fig. 2A). ZA did not significantly affect PV or MPG after AVS-procedure (Fig. 2B). Histological analysis revealed significantly greater cusp area in mice with AVS, but no difference for OVX- or ZA-groups (Fig. 2C). Picrosirius red staining showed a significantly decreased relative and absolute collagen content in aortic valves derived from mice with AVS, but no difference between OVX- or ZA-groups was detectable. Immature/degraded collagen was increased in mice with AVS.

Conclusion

Estrogen depletion and reduction in bone mineral density did affect AVS development in C57BL6/J mice. Application of ZA was effective in preventing bone loss, but did not change AVS-severity.

Further histological analysis of the aortic valves could reveal potential differences in cardiovascular osteoclast- and immune cell-infiltration.Figure 1Figure 2
Optimal pixel signal intensity threshold for the assessment of endocardial left-ventricular scar by 3D dark blood MRI compared to bipolar voltage electro-anatomical mapping
Authors: Kaya Y S , Stoks J , Gommers S , Holtackers R J , Duijsings R , Vernooy K , Volders P , Ter Bekke R
Published: November 2023

Background

Late gadolinium enhancement (LGE) MRI is considered the standard for noninvasive assessment of 3D scar architecture. Intraprocedural integration of 3D scar models improve the outcome of catheter ablation for ventricular tachycardia (VT). A pixel signal intensity (PSI) cut-off of 40 to 60% has been widely used for conventional bright-blood LGE MRI. Novel 3D MRI acquisitions with dark-blood (DB) nulling with higher spatial resolution and superior detection of (subendocardial) scar patterns are increasingly available, but the optimal pixel signal intensity (PSI) value remains unknown.

Purpose

To compare the accuracy of the 3D DB MRI-derived endocardial scar reconstructions at three different PSI cut-offs with endocardial electro-anatomical contact mapping in patients with scar-related VT.

Methods

Preprocedural 3D DB LGE MRIs were retrospectively compared to high-density endocardial left-ventricular (LV) bipolar voltage mapping (cut-off 0.5-1.5mV) obtained during endocardial mapping at sinus rhythm using the ADAS3D software. The LV scar models were aligned using the mitral valve, left ventricular apex and aorta cusps. Points with a Euclidean node-to-node distance of ≥10 mm were excluded. Variable upper PSI thresholds were set at 50%, 60% and 70%; the lower threshold at two-thirds of the upper limit. The 10% LV layer from the 3D MRI was used. The pairs of points were checked for agreement for scar or healthy (%). The Pearson correlation was used to analyze the agreement between core scar, border zone and healthy tissue area (in %) at three thresholds.

Results

Ten patients (90% male, mean age 65±11 year, 8 ischemic/2 nonischemic, LV ejection fraction 41±6%) were analyzed. A mean of 2024 (range 385-6810) pairs were analyzed per patient at three PSI thresholds. A correct correlation for scar or healthy was present in 67%, 69% and 69% for the upper PSI thresholds of 50%, 60% and 70% respectively. The optimal match was obtained for an upper PSI cutoff value of 70%, for healthy (r2=0.57; P=0.01), border zone (r2=0.73; P=0.01), 50% for core (r2=0.09; P=0.39). Using a 60% PSI cutoff the scar core % increased significantly compared to the 70% cutoff (12.8 ±13.8 versus 4.9±7.3, P=0.001).

Conclusion

The optimal depiction of the boundary between healthy and border zone scar by 3D DB MRI is best depicted at an upper PSI threshold of 70%.
The role of cellular senescence in aortic dissection
Authors: Nakao E , Aoki H , Hashimoto Y , Majima R , Hori-Hayashi M , Ito S , Ohno-Urabe S , Furusho A , Nishida N , Hirakata S , Fukumoto Y
Published: November 2023

Background

Aortic dissection (AD) is a catastrophic disease with high mortality. Survived patients frequently suffer from serious complications due to progressive destruction of the aortic walls. Recently we have reported that cell proliferation precedes the inflammatory response which is important in AD development and progression. Since cell proliferation promotes cellular senescence that can induce inflammatory response through SASP (senescence-associated secretary phenotype), we hypothesized that cellular senescence plays a critical role in AD pathogenesis.

Purpose

To investigate if cellular senescence contributes to AD pathogenesis in a mouse AD model.

Methods and Results

A mouse AD model was created by continuous infusion of beta-aminopropionitrile and angiotensin II (BAPN+AngII), where AD occurs to most of the mice in 14 days. BAPN+AngII challenge resulted in the appearance of senescent cells in the aortic walls before AD onset, which persisted for 14 days. Senescent cells, as demonstrated by the expression of senescence-associated beta-galactosidase, were evident in multiple types including endothelial cells, medial smooth muscle cells, adventitial macrophages and fibroblasts. Rapamycin, an inhibitor of mTOR pathway, suppressed the cell proliferation, the cellular senescence, and the development and progression of AD. To examine the role of cellular senescence in AD pathogenesis, ABT263, which is a senolytic drug that eliminates senescent cells, was administered orally to AD model mice. ABT263 treatment reduced the expression of the senescence markers. In the ABT263-treated group, the AD mortality was significantly decreased compared to that in vehicle-treated group (35% vs 67%, P < 0.05 by log-rank test). The severity of AD, as assessed by the lesion length, was also attenuated in ABT263 group (24.6 ± 1.8 mm vs 33.2 ± 3.1 mm, P < 0.05). Transcriptome analysis revealed that ABT263 treatment suppressed the aortic immune and inflammatory response induced by BAPN+AngII. Quantitative RT-PCR of aortic tissue confirmed that ABT263 treatment prevented the induction of p21, interleukin-6, several chemokines and M1 macrophage marker (CD80). ABT263 treatment suppressed CD80 expression also in cultured macrophages.

Conclusions

These results indicated that cell proliferation and senescence via mTOR pathway are critically involved in AD pathogenesis. Cellular senescence contributes to the inflammatory response including M1 differentiation of macrophages, and to the severity and the mortality in AD. Cellular senescence could be a new therapeutic target for AD.
Gamma-delta T cells: their atherogenic actions and therapeutic potential in atherosclerosis
Authors: Kyaw T , Kanellakis P , Brassington K , Cao A , Toh B H , Bobik A
Published: November 2023

Introduction

Atherosclerosis, a chronic inflammatory disease of the arteries, is a major contributor to ischemic attacks in the heart. Immune cells are studied in atherosclerosis and recognized as important players in plaque instability; however, multipotent γδ-T cells are rarely studied. Here, we aim to investigate their role in chronic arterial inflammation and the therapeutic potential of targeting them in preventing plaque instability.

Methods

Depletion and repletion strategies were adopted to examine the critical role of bone marrow derived γδ-T cells in atherosclerosis. Their direct atherogenicity mediated by interferon- γ (IFN-γ) and perforin (pfp) was investigated in mixed chimeric mice with specific protein deficiency restricted to bone marrow derived γδ-T cells. Anti -mouse TCR γ/δ antibody was employed to examine the master regulatory role of γδ-T cells in plaque stability. Mice with established atherosclerosis were treated with small molecule CXCR3-antagonist, AMG487 to retard γδ-T cell-modulated plaque instability.

Results

We confirmed that bone marrow derived γδ-T cells promote atherosclerosis and plaque stability. They directly contribute to lesion inflammation and cell death via IFN-γ and pfp leading to expanding vulnerable plaques. In addition, γδ-T cells express innate activating receptors, NKG2D and DNAM-1, for their activation in lesion and activated γδ-T cells recruited proinflammatory and cytotoxic immune cells via chemoattractants Rantes and MIP-1α, suggesting their pivotal roles in lesion progression. AMG487 treatment inhibited γδ-T cells and other immune cells and reduced atherosclerotic lesions with stable plaque characteristics - less cytotoxicity, more vascular smooth cells and thicker caps.

Conclusion

We have shown that bone marrow-derived CD27-positive γδ-T cells are most important immune cells in atherosclerosis. They contribute lesion cytotoxicity and inflammation by direct effector functions and influencing other atherogenic cells, and targeting them with AMG487 may be beneficial to reduce generation of vulnerable plaques and subsequent rupture so that it can significantly reduce MI.
Development of a human in vitro model of bone marrow vascular niche on a chip to study CD34+ hematopoietic stem/progenitor cells function in diabetes
Authors: Campanile M , Persico G , Casciaro F , Noto G , Sambado L , Bettinelli L , Stefani P M , Sambataro M , Giorgio M , Cerutti C , Spinetti G
Published: November 2023

Background/Introduction

Protective bone marrow (BM) CD34+ hematopoietic stem/progenitor cells (HSPCs) are released in the bloodstream after cardiomacrovascular (CV) tissue damage such as myocardial infarction1. Diabetes, an high risk condition to develop CV diseases, results in BM damage2-4 and detrimental pro-apoptotic and pro-oxidant shifts in BM-derived CD34+HSPCs5,6. Being able to classify and study the mechanisms of CD34+HSPC-vascular cell interaction would be a great step forward in the CV research field. However, nowadays there is no available primary human cell-based in vitro model to study the BM vascular niche.

Purpose

We aim to develop a human-based in vitro model to reproduce the BM vascular niche that allows the analysis of molecular mechanisms involved in CD34+HSPC function. This model will be relevant to identify molecular targets beyond hypoglycemic treatment and potentiate personalized medicine applications for diabetic complications.

Method

Human endothelial cells and pericytes were isolated from femoral head of patient who underwent hip replacement or from ad hoc BM aspirate by magnetic bead separation and characterized by immunofluorescence staining and flow cytometry. A culture of endothelial and pericytic cells to replicate the BM vascular niche was developed on a chip. CD34+HSPC subpopulation alteration in diabetes was preliminarily evaluated through single cell sequencing analysis (scRNAseq) on CD34+HSPC cells isolated from BM of patients with or without diabetes (N=1).

Results

We successfully set up a new method to efficiently isolate autologous BM endothelial cells and pericytes derived from patients (N=3). The cells expressing typically endothelial (CD31, ZO-1, and VE-cadherin) and pericytic (CD146, CD140b) markers were cultured in a 2D chip model. ScRNAseq reveals 15 clusters of CD34+HSPCs and important differences between the non-diabetic and diabetic samples. In particular, cluster 2 is highly represented in the non-diabetic and completely disappears in the diabetic sample, while on the contrary cluster 9 is over-represented in the diabetic compared to the non-diabetic sample. Interestingly, though the trajectory analysis cluster 2 shows the highest probability of turning into cluster 9. Through Ingenuity Canonical Pathways analysis we identified the anti-oxidant pathway as the most affected in diabetes-derived CD34+HSPCs.

Conclusions

In vitro human vascular niche model could be the gold standard to study BM cell crosstalk. In our interest, cluster 2 completely disappears in diabetes-derived CD34+HSPCs, potentially representing the CV-protective CD34+HSPC fractions more prone to be mobilized. Developing of our in vitro model would be useful to validate this hypothesis.Figure 1:scRNAseq cluster UMAPFigure 2:Endothelial cells IF staining
Circulating long noncoding RNAs and risk of ischemic stroke or death in the elderly: insights from the VITA study
Authors: Lapikova-Bryhinska T , Ministrini S , Kraler S , Puspitasari Y M , Mohammed S , Costantino S , Riederer P , Fischer P , Hinterberger M , Paneni F , Luscher T , Grunblatt E , Akhmedov A , Camici G
Published: November 2023

Introduction

Long non-coding RNAs (lncRNAs) represent a superfamily of non-protein coding transcripts that regulate a variety of cellular processes and functions in health and disease. While our (patho-)physiological understanding of lncRNAs constantly evolves, their potential as cardiovascular biomarkers to predict adverse outcomes in the elderly remains poorly understood.

Method

A total of 361 healthy individuals aged 75, prospectively recruited in the Vienna Transdanube Aging (VITA) cohort, were included in the present analysis. A semi biased lncRNA screening strategy was employed: "Aging", ‘’stroke", "cardiac", "inflammation", and "neurodegenerative" served as keywords. The primary endpoint was a composite outcome of death and ischemic stroke. Death was assessed over a 14-year follow-up from public registries, and ischemic stroke was evaluated over a 90-month follow-up involving magnetic resonance imaging (MRI) based assessment. Expression of lncRNAs wasassessed using qRT-PCR (TaqMan Assays) with preamplification reaction, using 18S for normalization.

Results

The initial screening retrieved 24 lncRNAs, of which 6 showed a solid amplification signal. Over a median follow-up of 14 years, the incidence of the primary endpoint was 62.6%, with 53.5% deaths, 3.3% brain infarcts, and 12.7% lacunar strokes (which were studied during the 7.5 years).

H19 predicted the incidence of the primary endpoint (HR 1.675, 95% C.I. 1.076-2.607, p= 0.023), which was mainly driven by its strong association with mortality, independent of potential confounders (adjusted HR 1.789, 95% C.I. 1.083-2.955, p= 0.023). In contrast, NKILA was found to predict the incidence of lacunar stroke beyond established risk factors (adjusted HR 0.259, 95% C.I. 0.087-0.768, p= 0.015) but was unexpectedly not associated with mortality risk.

Conclusion

In a prospective cohort of healthy elderly subjects, high levels of lncRNA H19 are associated with a high mortality risk, while low levels of lncRNA NKILA predict an increased risk of lacunar stroke.
Epigenetic regulation of PCSK9 expression by statins
Authors: Duddu S , Chakrabarti R , Sharma P , Tiwari A , Shukla P C
Published: November 2023

Background

Statins are lipid-lowering drugs widely used to reduce the risk of cardiovascular diseases. Although they inhibit HMG-CoA, statins are known to induce the expression of PCSK9, a key regulator of plasma LDL-cholesterol. However, the underlying epigenetic mechanisms remain unknown.

Objective

This study aimed at investigating the histone modification-mediate epigenetic regulation of PCSK9 and the underlying mechanisms during statin treatment.

Methods

Using immunoblotting, qPCR, and immunofluorescence techniques we assessed various histone modifications and expression levels of PCSK9 and other cholesterol-regulating candidates upon statin treatment. Further, 4-6 weeks old C57BL/6 mice were subjected to high-fat diet in combination with atorvastatin for 10 weeks. We then performed ChIP-qPCR to evaluate the fold enrichment of targeted histone marks at the gene promoter regions of PCSK9 and SREBP.

Results

Atorvastatin and cholesterol-treated HepG2 cells were reported to have an increased transcript and protein expression of PCSK9. Further, screening of different histone methylation and acetylation marks under atorvastatin treatment revealed significant enrichment in the levels of the activating H3K4me3 and H3K9ac marks. ChIP-qPCR analysis suggested significantly higher enrichment of H3K4me3 and H3K9ac at the gene promoter region of PCSK9 and SREBP2 (Figure 1&2). In vitro pharmacological intervention against these histone modifications not only significantly lowered their activation but also attenuated statin-induced PCSK9 expression.

Conclusion

Together, these findings suggest that statins modulate the expression of PCSK9 by regulating H3K4me3 and H3K9ac levels at the PCSK9 gene promoter. Inhibition of these activating histone modifications repressed statin-dependent PCSK9 expression. Thus, targeting chromatin remodeling may help negate the adverse effects of statin treatment, primarily of increasing PCSK9 during hypercholesterolemia.
Inhibition of farnesylation of Ras-GTPases ameliorates inflammation-induced loss of endothelial barrier integrity and leukocyte transmigration
Authors: Guenduez D , Hamm C , Aslam M
Published: November 2023

Background and Aims

The family of small GTPases (Rho- and Ras-GTPases) is known to regulate endothelial cytoskeleton dynamics and hence barrier integrity. The role of Rho GTPases (RhoA and Rac1) in endothelial barrier integrity is well characterized; however, little is known about the role of Ras-GTPases. The activity of small GTPases is regulated by several mechanisms, including post-translational prenylation (farnesylation or geranylgeranylation). The Ras-GTPases are preferentially post-translationally farnesylated by farnesyl transferases (FTs). The aim of the present study was to investigate whether inhibition of farnesylation of Ras-GTPases protects loss of endothelial barrier integrity induced by inflammatory mediators.

Methods and Results

Treatment of human primary endothelial cells (ECs; HUVEC and lung microvascular ECs) with pharmacological inhibitor of farnesyl transferases (FTIs), LB42708 (LB) and tipifarnib, stabilized basal endothelial barrier function (albumin-flux) and abrogated thrombin-induced hyperpermeability in a concentration- and time-dependent manner reaching maximum at a concentration of 2 mmol/L after 12 h of incubation. These concentrations of the FTIs reduced farnesylation of all the Ras isoforms but not the geranylgeranylation of Rho GTPases. Likewise, LB abrogated the TNFa-induced leucocyte transendothelial migration (Trans-well assay). Interestingly, FTIs treatment caused an enhanced translocation of VE-cadherin to cell-cell junctions (confocal microscopy) without exerting any effect on the actin cytoskeleton or endothelial contractile machinery; mainly regulated by Rho GTPases. The Ca2+-switch experiments demonstrated an inhibition of VE-cadherin internalization. These data were reproduced by lentiviral-mediated stable over-expression of the prenylation-dead mutants of Ras isoforms but not RhoA or Rac1.

Conclusion

The novel data of the present study demonstrate that FTIs protect endothelial barrier function against inflammatory mediator-induced endothelial hyperpermeability. We propose that FTIs are novel drug candidates for the treatment of edematous conditions (such as lung edema) where endothelial barrier integrity is compromised.
Kallstatin/Serpina3c improves hyperlipidemia induced by high-fat diet via regulating glycolipid metabolism in adipose tissue
Authors: Guo J , Ji Z , Ma G , Yao Y
Published: November 2023

Background

Hyperlipidemia is an independent risk factor for cardiovascular diseases. Studies showed that the plasma Kallstatin (KS) in obese patients was reduced, and the decreased KS in obese patients with type 2 diabetes was increased after weight loss. The mouse homologous gene of human KS is Serpina3c, and the relationship between KS/Serpina3c and hyperlipidemia and its regulatory mechanism are unclear.

Purpose

To explore whether KS/Serpina3c improves hyperlipidemia and specific mechanisms.

Methods

The serum KS level of Chinese hyperlipidemia population was detected by ELISA. Serpina3c knockout mice (Serpina3c KO) were constructed based on the strategy of Cre/loxP recombination system. The adipocyte-specific Serpina3c knockout adeno-associated virus (AAV8-shSerpina3c) and control (AAV8-shNC) were constructed, and the adipocyte-specific Serpina3c overexpression adeno-associated virus (AAV8-Serpina3c) were constructed. The 8-week-old C57BL/6J mice were injected with AAV8-shSerpina3c or AAV8-shNC in situ into the inguinal adipose tissue (iWAT). Serpina3c KO mice were injected with AAV8-Serpina3c or AAV8-shNC in situ into the iWAT. The mice model of hyperlipidemia was established by feeding high-fat diet (HFD) for 16 weeks. The fat content of mice was observed with 7.0T magnetic resonance imaging (MRI)system. The serum triglyceride, total cholesterol, LDL and HDL were detected with the kit. Serpina3c KD, Serpina3c OV or control 3T3-L1 adipocytes were stimulated by PA for RNA-seq.

Results

(1) The serum KS decreased in hyperlipidemic people in China. (2) The 7.0T MRI system displayed bigger fat in the Serpina3c KO mice and AAV8-shSerpina3c mice. (4) The serum results showed higher lipids in Serpina3c KO and AAV8-shSerpina3c mice. (5) Oil red O staining showed increased lipid deposition in liver, muscle and heart. (6) The RNA-seq results revealed that the HIF1α and glycolysis pathways of Serpina3c KD adipocyte increased, while the fatty acid metabolic pathway decreased. The results of primary adipocytes verified the increase of glycolysis and decreased β oxidation. (7) And the fatty acid uptake in liver, heart and muscle tissue of Serpina3c KO mice and AAV8-shSerpina3c mice increased, and the β oxidation decreased.

Conclusions

The expression and secretion of KS/Serpina3c decreased in HFD adipose, which promotes glycolysis and inhibits fatty acids β oxidation of adipocytes. On the one hand, the decrease of Serpina3c activates glycolysis and increases the production of glycerol 3-phosphate by activating HIF1α. On the other hand, CPT1 was inhibited by increased HIF1α, impeding the activated fatty acid (Fatty-acyl-CoA) in the cytoplasm entering the mitochondria through CPT1. Glycerol 3-phosphate and fatty acyl CoA accumulated in the cytoplasm of adipocyte synthesize triglycerides through the diglyceride pathway, aggravating hyperlipidemia induced by HFD.Schematic diagram
Dapagliflozin decreases atherosclerotic plaque instability via regulating macrophage pyroptosis
Authors: Xu L , Dai Y , Qian J , Ge J
Published: November 2023

Background

Vulnerable plaques are characterized by infiltration of inflammatory cells, playing a key role in the progression of acute coronary events. It’s important to clarify the inflammatory mechanism of unstable plaque formation. Several clinical trials have demonstrated that dapagliflozin could reduce major adverse cardiac events in whether diabetic or non-diabetic patients. However, the underlying cardioprotective mechanism of dapagliflozin remains unclear. This study was aimed to investigate the role of dapagliflozin in regulating macrophage pyroptosis and vulnerable plaque formation.

Methods

20 ApoE-/- mice (control) were fed with high fat diet while another 20 ApoE-/- mice were challenged with high fat diet plus dapagliflozin for 12 weeks. The extent and instability of atherosclerotic plaque was determined by oil-red staining, HE staining, immunofluorescence staining and electron microscopy. Changes in subsets of immune cells were evaluated by flow cytometry. Plasma cytokines were assessed by ELISA. Microarray analysis was applied to detect gene expressions while Western blot and real-time PCR was used to assess gene expression levels.

Results

Morphology studies revealed that dapagliflozin could inhibit plaque formation and reduce instability in ApoE-/- mice. FACS data showed that dapagliflozin could decrease CD11b+Ly6Chigh M1 macrophages differentiation and inhibit foam cells formation in ApoE-/- mice. Microarray analysis and in vitro studies exhibited that dapagliflozin could induce the down regulation of NLRP3, caspase-1, IL-1β, IL-18 and MMP-7/10/12/14 to retard macrophage pyroptosis and foam cell formation.

Conclusions

We have characterized a novel role for dapagliflozin in modulating atherosclerotic lesion development and progression. We envision that this study may provide several potential therapeutic targets for treatment of acute coronary syndromes.
ZAP (Zero-Fluoro - ALARA Procedures) EP: A UK Tertiary Centre Safety and Efficiency Evaluation
Authors: Makris N , Kotsialou Z , Elbanhawy N , Ariyaratnam J , Chalil S , Gall S , Chu G , Arujuna A
Published: November 2023

Background

3D mapping facilitates zero-fluoro (ZF) and as-low-as-reasonably-achievable (ALARA) procedures which allows for minimizing exposure to harmful radiation and maximizing lead-free time in the EP lab.

Objective

Safety, efficiency, radiation time and dose exposure was assessed in a consecutive unselected supraventricular tachycardias (SVT) cohort.

Methods

Retrospective and prospective analysis comparing procedure time, complications and radiation dose and time between ZAP (ZF, ALARA) and non-ALARA cases was performed between January 2021 to August 2022. Radiation exposure was expressed as dose-area product (DAP). We included AVNRTs, accessory pathway (AP) ablations and EP studies.

Results

A total of consecutive 279 patients were included, of which 116 were ZAP (40 were ZF cases) and 163 non-ALARA. Median age was 52.5 for ZAP and 47.5 for non-ALARA patients. In specific, 131 AVNRT ablations (50 ZAP, 81 non-ALARA), 45 AP ablations (23 ZAP, 22 non-ALARA) and 103 EP studies (43 ZAP, 60 non-ALARA) were included. A comparative analysis of DAP between ZAP and non-ALARA cohort in both AVNRT ablations and EP studies demonstrated statistical significance with corresponding values of 3.15±4.4 vs. 6.04±7.5 Gy.cm2 (p=0.001) and 1.94±1.8 vs. 3.78±3.9 Gy.cm2 (p=0.024) (Figure 1). Significantly shorter fluoroscopy duration was also noted 6.07±6 vs. 12.44±7.5 min (p<0.001; AVNRT) and 4.23±4.2 vs. 6.16±4.1 min (p=0.01; EPS). For AP ablations there was a trend in favour of ZAP but not significant difference (DAP: 8.52±7.7 vs. 10.65±9 Gy.cm2, p=0.43; fluoroscopy duration: 12.12±8.7 vs. 15.9±8.3 min, p=0.33) (Figure 1). This might be attributed to the relatively smaller number of AP cases. Complication rates and procedure time were not different between ZAP and non-ALARA cases.

Conclusion

Lower fluoroscopy time with reduced radiation exposure is seen in ZAP cases compared to non-ALARA procedures for AVNRT ablations and EP studies. Future ICE navigation in complex cases may further reduce fluoroscopy need.Figure 1
Colchicine prevents accelerated atherosclerosis development in TET2-mutant clonal hematopoiesis
Authors: Zuriaga M A , Yu Z , Matesanz N , Truong B , Asensio-Lopez M C , Uddin M M , Nakao T , Niroula A , Zorita V , Moro R , Ebert B L , Honigberg M , Pacual-Figal D , Natarajan P , Fuster J J
Published: November 2023

Background

Somatic mutations in the TET2 gene that lead to clonal hematopoiesis are associated with accelerated atherosclerosis development in mice and a higher risk of atherosclerotic cardiovascular disease events in humans. Mechanistically, these observations have been linked to exacerbated vascular inflammation.

Purpose

Here, we sought to evaluate whether colchicine, a widely available and inexpensive anti-inflammatory drug, prevents the accelerated atherosclerosis associated with TET2-mutant clonal hematopoiesis.

Methods

In mice, we mimicked TET2-mutant clonal hematopoiesis using a competitive bone marrow transplantation approach in atherosclerosis prone Ldlr/- mice. We generated hematopoietic chimeras carrying initially 10% Tet2-/- hematopoietic cells, which were fed a high-cholesterol diet and treated with colchicine or placebo. Atherosclerosis development was evaluated histologically. In humans, we analyzed whole exome sequencing data and electronic medical records from 50,291 participants in a hospital-based cohort to examine the potential modifying effect of colchicine prescription on the association between clonal hematopoiesis and myocardial infarction.

Results

Colchicine prevented the development of accelerated atherosclerosis in the mouse model of TET2-mutant clonal hematopoiesis, without affecting serum cholesterol levels or the expansion of TET2-deficient hematopoietic cells. In humans, consistent with experimental findings, patients who were prescribed colchicine had attenuated associations between TET2-mutant clonal hematopoiesis and myocardial infarction (ORno colchicine [95% CI]: 1.18 [0.93-1.48]; ORcolchicine [95% CI]: 0.78 [0.45-1.35]; Pinteraction=0.03). This interaction was not observed for carriers of other clonal hematopoiesis-related mutations, such as those affecting DNMT3A or ASXL1.

Conclusions

Our results highlight the potential value of colchicine as a targeted preventive care strategy to mitigate the higher cardiovascular risk of carriers of somatic TET2 mutations in blood cells. These observations set the basis for the development of clinical trials that evaluate the efficacy of precision medicine approaches tailored to the effects of specific somatic mutations linked to clonal hematopoiesis.
The senolytic agent Dasatinib reduces fat accumulation in the heart and bone marrow of type 2 diabetic, obese mice and adipogenesis of human bone marrow pericytes
Authors: Gu Y , Alvino V V , Avolio E , Morelli M B , Thomas A C , Herman A , Miller P J , Sullivan N P T , Madeddu P
Published: November 2023

Background

Inflammaging, a chronic inflammatory state associated with aging and obesity, participates in the pathogenesis of cardiovascular disease and type 2 diabetes (T2D). Adipocyte accumulation in bone marrow (BM) may contribute to this phenomenon. Senolytic drugs, like Dasatinib, reportedly eliminate senescent preadipocytes. However, the effects of Dasatinib on fat deposits in the heart and BM remain unknown.

Purposes

This study aimed to identify the cellular source of adipocytes in human BM and determine whether treatment with Dasatinib reverses adiposity and improves cardiovascular function in T2D obese mice.

Methods and results

Human CD34neg CD45neg CD146pos pericytes (hBM-PCs) were sorted from BM mesenchymal stem cells (hBM-MSCs) by immunomagnetic beads. HBM-PCs showed a higher propensity to differentiate into Oil red O positive (pos) adipocytes after 21 days of stimulation in a pro-adipogenic medium (P=0.0299 vs. hBMSCs (hBM-MSCs except for hBM-PCs)). Dasatinib treatment reduced the number of viable cells (P=0.0034 vs. Vehicle (DMSO)) and the rate of adipocyte differentiation (P= 0.0179 vs. Vehicle). In a randomized blind study, Dasatinib (5 mg/kg) or vehicle (10% DMSO+90% PEG-300) was given by oral gavage to T2D, obese 21-week-old male BKS.Cg-+Leprdb/+Leprdb/OlaHsd (Db/Db) mice. Groups of animals were sacrificed at 1 or 4 weeks. Dasatinib reduced the Oil red O pos cells in the heart (P= 0.001 and 0.045) and BM (P= 0.018 and 0.0253) at both time points. Senescence marker p16INK4a expression and plasma adipokines levels were similar between the two groups at one week. With long-term treatment, the expression of senescence marker p16INK4a was significantly reduced in the murine hearts (P=0.035) and BM (P=0.068), whereas adipokines levels were similar. In vitro treatment of murine BM-MSCs with Dasatinib reduced the expression of p21Waf1/Cip1 (P= 0.030). VisualSonics 3D echocardiography showed similar diastolic and systolic function in Dasatinib- or Vehicle-treated mice: stroke volume (P= 0.494); ejection fraction (P= 0.701); fractional shorten (P= 0.807); and cardiac output (P= 0.437).

Conclusion

Pericytes are the primary source of adipocytes in human BM. The senolytic agent Dasatinib reduces pericyte commitment to adipogenesis. The senolytic agent prevented fat accumulation and cell senescence in the BM and heart of T2D mice. However, more prolonged treatment may be necessary for the reduced adiposity to translate into improvements in heart function.
Dapagliflozin downregulates G protein-coupled receptor Kinase-2 and upregulates regulator of g protein signaling-4 in adrenals to exert sympatholysis in heart failure
Authors: Lymperopoulos A , Del Calvo G , Baggio Lopez T , Carbone A , Borges J , Suster M , Maning J , Iacobellis G , Goldberger J
Published: November 2023

Dapagliﬂozin is a sodium-glucose co-transporter (SGLT)-2 inhibitor with beneficial cardiovascular effects independent of its anti-diabetic actions. Among these is sympatholysis, i.e., norepinephrine (NE) lowering which is beneficial in chronic human heart failure (HF). Adrenal G protein-coupled receptor kinase (GRK)-2 upregulation is a major driver of circulating catecholamine (CA) elevation and sympathetic nervous system (SNS) hyperactivity in HF due to dysregulation of adrenal sympatho-inhibitory α2-adrenergic receptors (ARs) [1]. On the other hand, we recently reported that signaling by neuronal free fatty acid receptor (FFAR)-3, which stimulates NE release from sympathetic neurons, is blocked by Regulator of G protein Signaling (RGS)-4 [2,3]. We hypothesized herein that dapagliﬂozin may lower SNS hyperactivity in the adrenal gland by improving α2AR, and antagonizing FFAR3 signaling in adrenal chromafﬁn cells. We used the rat pheochromocytoma PC12 cell line expressing human α2A-AR, as well as freshly isolated adrenal glands from rats treated with dapagliﬂozin in vivo. Dapagliﬂozin treatment for 7 consecutive days (20 mg/kg/d in drinking water) led to a signiﬁcant reduction in blood circulating NE levels (217+67 pg/ml, n=6), compared to control, vehicle-treated rats (363+77 pg/ml, n=6, p<.05), suggesting reduced SNS activity. This was accompanied by reduced GRK2 and tyrosine hydroxylase (TH) mRNA and protein levels in dapagliﬂozin-treated rat adrenals vs. vehicle-treated animal-derived glands. In contrast, RGS4 mRNA levels were increased in dapagliflozin-treated adrenals. Adrenal α2AR density was higher in dapagliﬂozin- vs. vehicle-treated rats (51.3+7.3 vs. 26.1+8.1 fmol/mg of protein, respectively; n=12 glands from 6 animals per group, p<.05). These results (i.e., GRK2 & TH downregulation with RGS4 upregulation) were completely recapitulated in PC12 cells in culture, treated with 5 microM dapagliﬂozin (or vehicle) for 24 hours. Importantly, α2AR-dependent G protein-mediated signaling towards inhibition of CA secretion was markedly enhanced, whereas FFAR3-dependent phospholipase C/calcium signaling was reduced, at 24 hrs post-dapagliﬂozin treatment of PC12 cells. GRK2 overexpression partially reversed dapagliflozin`s effect on cholinergic-induced CA secretion. In conclusion, dapagliﬂozin exerts a sympatholytic action in the adrenal medulla via a) downregulation of TH, which reduces CA biosynthesis, and GRK2, which reduces α2AR desensitization; and b) upregulation of RGS4 to block FFAR3-stimulated CA secretion (Figure).Figure
Effective cardiac mRNA delivery using lipid nanoparticles
Authors: Labonia M C I , Estape Senti M , Van Der Kraak P H , Brans M A D , Deshantri A K , Dokter I , Schiffelers R M , Sluijter J P G , Vader P
Published: November 2023

Background/Introduction

Heart failure is a global health burden for which there is no curative treatment available that aims to recover the impaired cardiac function.(1) Messenger RNA (mRNA) has emerged as a promising tool for protein replacement therapy. Endogenous mechanisms that enable repairing the heart can potentially be triggered by cardiac messenger RNA (mRNA) delivery.(2,3) Furthermore, the mRNA molecule can be modified in its secondary structure in order to reduce its immunogenicity and susceptibility to degradation by RNases. Clinical application of modified mRNA (modRNA) is challenged by the lack of effective and safe delivery systems. Lipid nanoparticles (LNPs) represent a well characterized class of mRNA delivery systems, which were recently approved for clinical usage in mRNA-based covid-19 vaccines.

Purpose

We compared cardiac delivery efficiency between different mRNA-LNPs formulations and naked mRNA in citrate buffer upon intramyocardial administration in mice. Furthermore, we aimed to identify cardiac cell types that were targeted. Finally, we assessed whether LNP administration induces a local immunogenic response.

Methods

Different LNP formulations were tested in vitro and in vivo for luciferase or GFP – encoding modRNA delivery. In vitro, LNP mediated modRNA delivery was assessed in human endothelial cells (HMEC-1), induced pluripotent stem cell-derived cardiomyocytes (iPS-CMs) and induced pluripotent stem cell -derived fibroblasts (iPS-FBs). In vivo, mice undergoing open chest heart surgery under general anaesthesia were intramyocardially injected with 2.5μg modRNA in LNPs or in citrate buffer. In order to quantify tissue distribution of mRNA delivery levels, luciferase expression was measured in various organs 24h after administration. Moreover, to identify cellular uptake specificity, histology was performed on mice treated with GFP modRNA.

Results

mRNA-LNPs outperformed naked mRNA upon intramyocardial administration in mice (figure 1 a, d-i). Although LNPs were mainly in the injection site in the left ventricular wall (Figure 1 b), the liver showed to be the main mRNA-LNP target organ(figure 1 a,b). mRNA-LNPs showed targeting of epicardial and interstitial cardiac cells (figure 1c). Among the tested C12-200 LNP formulations, no differences in in vivo delivery efficiency were observed (Figure 1 a, d). Most importantly, variations on the ionizable lipid LNP component determined the LNP local immune response.

Conclusion(s)

We present a proof of concept of a promising strategy for delivering mRNA to the heart by using LNPs as delivery systems, which proved to be more efficient than the current state of the art (mRNA in citrate buffer). LNP optimization to better target the heart could introduce a novel approach to achieve cardiac tissue repair.
Changes in study enrollment of patients with non-ischemic cardiomyopathy receiving an ICD for primary prevention: Insights from the APPRAISE ATP study
Authors: Mont L , Daubert J , Zareba W , Kutyifa V , Ando K , Wold N , Yong P , Schuger C
Published: November 2023

Introduction

The DANISH study called into question the effectiveness of the ICD in patients (pts) with non-ischemic cardiomyopathy (NIC) and resulted in a downgrade in ESC guidelines from Class I to Class IIA. The effect of these findings on implantation of ICDs in NIC pts in clinical studies has not been well established.

Methods

Two clinical studies were analyzed before and after the publication of DANISH: MADIT-RIT (2009-2012) and APPRAISE ATP (2017-present). These two studies enrolled globally and implanted ICDs in pts with primary prevention (PP) indications. The proportion of pts with NIC were analyzed between the two studies, both globally and by region: North America (NA) and European Union (EU). In addition, the APPRAISE ATP study was divided into halves to determine if any changes were observed whilst the study was in progress. Continuous variables were analyzed with a t-test and categorical variables were analyzed with a Chi-square test. Due to small numbers, implanted pts outside NA and the EU were not entered into the analysis.

Results

Demographics for the NIC subgroups are shown in the table below [MADIT-RIT (n=284) and APPRAISE ATP (n=1084)]. When compared to MADIT-RIT, pts in APPRAISE ATP were significantly older, had a higher mean LVEF, and greater prevalence of AF and diabetes. Globally, the proportion of pts with NIC who received ICDs was unchanged between the current APPRAISE ATP study and MADIT-RIT 10 years previously (38.1% vs 39.3%, p=0.91). When analyzed by geography, there was no change in North America (38.0% vs 41.6%, p=0.27). In Europe, however, there was a drop in enrollment of NIC ICD pts from 38.6% in MADIT-RIT to 29.1% in APPRAISE ATP. This decline was 24.6% in relative terms and approached, but did not achieve, statistical significance (p=0.074).

Implant rates in NIC ICD pts were stable overall when comparing the first half of APPRAISE ATP to its second half. Rates were also stable across both halves in NA and while implant rates of NIC ICD pts appeared to rebound in the second half in the EU, that late increase was not statistically significant.

Conclusions

The results of the DANISH study appear to have had a limited global impact on enrollment of NIC pts requiring implant of a PP ICD into the APPRAISE ICD clinical study. Whilst there was no change in North America before and after DANISH, there is a signal in the data that investigators in the EU may have restricted implants initially but eventually relaxed as time progressed. Further investigation is needed to confirm whether physicians in general practice have altered their referral patterns.
Poor glycemic control is associated with the prevalence of left atrial low-voltage areas in patients with atrial fibrillation ablation
Authors: Matsuda Y , Masuda M , Uematsu H , Sugino A , Ooka H , Kudo S , Fujii S , Asai M , Iida O , Okamoto S , Ishihara T , Nanto K , Tsujimura T , Hata Y , Mano T
Published: November 2023

Background

Although glycemic control before atrial fibrillation (AF) ablation is associated with AF recurrence after the procedure, the mechanism has not been fully clarified. Left atrial low-voltage areas (LVAs) were known to be correlated with atrial scarring and AF recurrence after ablation, and a preliminary study showed that the past history of diabetes mellitus (DM) was an independent predictor of LVAs. However, the association between LVAs and glycemic control before ablation has not been elucidated.

Purpose

The purpose of this study was to investigate the association between glycemic control before AF ablation and the prevalence of LVAs in patients with AF ablation.

Methods

The study design was a single center, retrospective observational study. Between December 2014 and December 2018, 782 (age, 68 ± 10 years; female, 262 [34%]; persistent AF, 414 [53%]) consecutive patients who underwent initial AF ablation were included. Glycated hemoglobin A1c (HbA1c) levels were measured before the procedure, and HbA1c ≥ 7% was set as the cut-off value of poor glycemic control in patients with DM. The definition of LVAs was sites with a left atrial bipolar amplitude < 0.5 mV covering as ≥ 5 cm². Rhythm outcome after the procedure was followed for 24 months.

Results

Of 782 patients, 162 (21%) patients had LVAs, and 135 (17%) patients had past history of DM. LVAs were found more frequently in patients with poor glycemic control (Figure 1). On multivariate analysis, DM with HbA1c ≥7% was an independent predictor of LVAs (odds ratio, 3.6; 95% confidence interval: 1.8–7.0; p < 0.001). In patients with LVAs, freedom from AF recurrence during the study periods tended to be lower in patients who had DM with HbA1c ≥7% than in those with non-DM (40.3% versus 51.6%, p = 0.06) (Figure 2).

Conclusions

In patients with AF ablation, LVAs were found more frequently in patients with poor glycemic control. In particular, DM with HbA1c ≥7% was an independent predictor of LVAs.Prevalence of LVAs and glycemic controlAF recurrence and glycemic control
Appropriate selection of substrate ablation in patients with persistent atrial fibrillation using an on-day assessment of baseline rhythm and trigger origin
Authors: Matsunaga Y , Egami Y , Ukita K , Yasumoto K , Okamoto N , Yano M , Tanaka N , Masuda M , Watanabe T , Inoue K , Sunaga A , Hikoso S , Sakata Y , Nishino M , Tanouchi J
Published: November 2023

Background

It has not been fully elucidated which patients with persistent atrial fibrillation (PerAF) should undergo substrate ablation.

Purpose

To identify the appropriate patients with PerAF who required an additional substrate ablation plus pulmonary vein isolation (PVI) using an on-day assessment of the baseline rhythm during the procedure and origin of the AF trigger.

Methods

This study was a post hoc sub-analysis of the EARNEST-PVI (Effect of Extensive Ablation on Recurrence in Patients with Persistent AF Treated with Pulmonary Vein Isolation) trial, which was a prospective, multicenter, randomized, open-label trial, comparing the PVI-alone and PVI-plus arms. The patients were divided into 2 groups according to the baseline rhythm and origin of the AF trigger. AF trigger was induced before catheter ablation using isoproterenol infusion (maximum dose of 0.4 μg/kg/min). Proven pulmonary vein (PV) triggers were defined as reproducible AF triggers from only the PVs. Group A consisted of patients with sinus rhythm at the baseline or proven PV triggers. Proven PV triggers were defined as reproducible AF triggers from only the PVs. Group B consisted of the remaining patients, who were AF at baseline and had non-proven PV triggers. The arrhythmia-free survival after a 3-month blanking period was assessed.

Results

Among the group A patients (n=327, Figure 1), the arrhythmia-free survival did not significantly differ between the PVI-alone and PVI-plus arms (p=0.276, HR 1.22, 95% CI: 0.85-1.76) (Figure 2, upper panel). Among the group B patients (n-166, Figure 1), who had AF at baseline and non-PV triggers, the arrhythmia-free survival was significantly lower in the PVI-alone than PVI-plus arm (p=0.032, HR 1.68, 95% CI: 1.04-2.70) (Figure 2 lower panel).

Conclusion

The on-day assessment of the baseline rhythm and trigger origin could distinguish patients who benefited from an additional ablation plus PVI. With an additional ablation plus PVI, the patients with sinus rhythm at baseline or who had proven PV triggers did not receive any benefit, whereas those with AF at baseline and no proven PV triggers received a benefit.Figure 1Figure 2