CCL2-mediated endothelial injury drives cardiac dysfunction in long COVID.

Evidence linking the endothelium to cardiac injury in long coronavirus disease (COVID) is well documented, but the underlying mechanisms remain unknown. Here we show that cytokines released by endothelial cells (ECs) contribute to long-COVID-associated cardiac dysfunction. Using thrombotic vascular tissues from patients with long COVID and induced pluripotent stem cell-derived ECs (iPSC-ECs), we modeled endotheliitis and observed similar dysfunction and cytokine upregulation, notably CCL2. Cardiac organoids comprising iPSC-ECs and iPSC-derived cardiomyocytes showed cardiac dysfunction after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure, driven by CCL2. Profiling of chromatin accessibility and gene expression at a single-cell resolution linked CCL2 to 'phenotype switching' and cardiac dysfunction, validated by high-throughput proteomics. Disease modeling of cardiac organoids and exposure of human ACE2 transgenic mice to SARS-CoV-2 spike proteins revealed that CCL2-induced oxidative stress promoted post-translational modification of cardiac proteins, leading to cardiac dysfunction. These findings suggest that EC-released cytokines contribute to cardiac dysfunction in long COVID, highlighting the importance of early vascular health monitoring in patients with long COVID.

A Novel Stem Cell Model to Study Preeclampsia Endothelial Dysfunction.

Preeclampsia is a common pregnancy complication affecting 5% to 7% of all pregnancies worldwide annually. While the pathogenesis is not fully understood, maternal endothelium dysfunction is thought to be a central component to preeclampsia development. Studies to dissect maternal endothelial dysfunction, particularly on a patient-specific basis, are hampered by limited access to systemic primary endothelial cells (ECs). The objective of this study was to establish a replenishable, patient-specific in vitro EC model to allow robust mechanistic studies to dissect endothelial dysfunction in preeclampsia. Induced pluripotent stem cells (iPSCs) from three women with a history of normotensive pregnancies were differentiated into ECs. The established ECs were exposed to pooled sera from normotensive pregnancies, preeclamptic pregnancies, normotensive postpartum for non-pregnant comparison and controls. Endothelial functions including nitric oxide (NO) release, cell migration, tube formation and viability were evaluated. Levels of NO release were significantly lower after incubation with preeclamptic sera compared to the fetal bovine serum (FBS) control, and normotensive and non-pregnant (postpartum) sera treatments were also lower than FBS but higher than preeclamptic sera treatments. Tube formation and cell migration were also impaired with preeclamptic sera compared to FBS controls. Cell viabilities remained unaffected by any sera treatment. Consistent outcomes were obtained across all three patient-specific lines treated with the same pooled sera. Establishment of patient-derived iPSC-ECs treated with pregnancy sera serves as a novel model to explore the interplay between individual maternal endothelial health and circulating factors that lead to endothelial dysfunction in preeclampsia.

Generation of two iPSC lines from dilated cardiomyopathy patients with pathogenic variants in the SCN5A gene.

Dilated cardiomyopathy (DCM) is a disorder of cardiac ventricular dilation and contractile dysfunction that often progresses to heart failure. Multiple genes have been associated with DCM, including SCN5A which has been linked to 2 % of all DCM cases. Peripheral mononuclear blood cells from DCM patients with SCN5A variants (c.2440C>T and c.665G>A) were utilized to generate two human induced pluripotent stem cell (iPSC) lines. Both lines exhibited typical iPSC morphology, expressed pluripotency markers, normal karyotypes, and trilineage differentiation capabilities. These lines offer valuable resources for investigating the mechanism of SCN5A-associated DCM, facilitating studies of ion channel protein involvement in the disease.

Cardiovascular Toxicity in Cancer Therapy: Protecting the Heart while Combating Cancer.

PURPOSE OF REVIEW: This review explores the cardiovascular toxicity associated with cancer therapies, emphasizing the significance of the growing field of cardio-oncology. It aims to elucidate the mechanisms of cardiotoxicity due to radiotherapy, chemotherapy, and targeted therapies, and to discuss the advancements in human induced pluripotent stem cell technology (hiPSC) for predictive disease modeling. RECENT FINDINGS: Recent studies have identified several chemotherapeutic agents, including anthracyclines and kinase inhibitors, that significantly increase cardiovascular risks. Advances in hiPSC technology have enabled the differentiation of these cells into cardiovascular lineages, facilitating more accurate modeling of drug-induced cardiotoxicity. Moreover, integrating hiPSCs into clinical trials holds promise for personalized cardiotoxicity assessments, potentially enhancing patient-specific therapeutic strategies. Cardio-oncology bridges oncology and cardiology to mitigate the cardiovascular side-effects of cancer treatments. Despite advancements in predictive models using hiPSCs, challenges persist in accurately replicating adult heart tissue and ensuring reproducibility. Ongoing research is essential for developing personalized therapies that balance effective cancer treatment with minimal cardiovascular harm.

Single-cell analysis identifies conserved features of immune dysfunction in simulated microgravity and spaceflight.

Microgravity is associated with immunological dysfunction, though the mechanisms are poorly understood. Here, using single-cell analysis of human peripheral blood mononuclear cells (PBMCs) exposed to short term (25 hours) simulated microgravity, we characterize altered genes and pathways at basal and stimulated states with a Toll-like Receptor-7/8 agonist. We validate single-cell analysis by RNA sequencing and super-resolution microscopy, and against data from the Inspiration-4 (I4) mission, JAXA (Cell-Free Epigenome) mission, Twins study, and spleens from mice on the International Space Station. Overall, microgravity alters specific pathways for optimal immunity, including the cytoskeleton, interferon signaling, pyroptosis, temperature-shock, innate inflammation (e.g., Coronavirus pathogenesis pathway and IL-6 signaling), nuclear receptors, and sirtuin signaling. Microgravity directs monocyte inflammatory parameters, and impairs T cell and NK cell functionality. Using machine learning, we identify numerous compounds linking microgravity to immune cell transcription, and demonstrate that the flavonol, quercetin, can reverse most abnormal pathways. These results define immune cell alterations in microgravity, and provide opportunities for countermeasures to maintain normal immunity in space.

Generation of two iPSC lines from vascular Ehlers-Danlos Syndrome (vEDS) patients carrying a missense mutation in COL3A1 gene.

Vascular Ehlers-Danlos Syndrome (vEDS) is an inherited connective tissue disorder caused by COL3A1 gene, mutations that encodes type III collagen, a crucial component of blood vessels. vEDS can be life-threatening as these patients can have severe internal bleeding due to arterial rupture. Here, we generated induced pluripotent stem cell (iPSC) lines from two vEDS patients carrying a missense mutation in the COL3A1 (c.226A > G, p.Asn76Asp) gene. These lines exhibited typical iPSC characteristics including morphology, expression of pluripotency markers, and could differentiate to all three germ layer. These iPSC lines can serve as valuable tools for elucidating the pathophysiology underlying vEDS.

Generation of induced pluripotent stem cell line from a patient suffering from arterial calcification due to deficiency of CD73 (ACDC).

Arterial calcification due to deficiency of CD73 (ACDC) is an adult onset, rare genetic vascular disorder signified by calcium deposition in lower extremity arteries and joints of hands and feet. Mutations in NT5E gene has been shown to be responsible for the inactivation of enzyme CD73 causing calcium buildup. Here, we report a iPSC line generated from a patient showing signs of ACDC and carrying a missense mutation in NT5E (c.1126A→G,p.T376A) gene. This iPSC line shows normal morphology, pluripotency, karyotype, and capability to differentiate into three germ layers, making it useful for disease modeling and investigating pathological mechanisms of ACDC.

Statins improve endothelial function via suppression of epigenetic-driven EndMT.

The pleiotropic benefits of statins in cardiovascular diseases that are independent of their lipid-lowering effects have been well documented, but the underlying mechanisms remain elusive. Here we show that simvastatin significantly improves human induced pluripotent stem cell-derived endothelial cell functions in both baseline and diabetic conditions by reducing chromatin accessibility at transcriptional enhanced associate domain elements and ultimately at endothelial-to-mesenchymal transition (EndMT)-regulating genes in a yes-associated protein (YAP)-dependent manner. Inhibition of geranylgeranyltransferase (GGTase) I, a mevalonate pathway intermediate, repressed YAP nuclear translocation and YAP activity via RhoA signaling antagonism. We further identified a previously undescribed SOX9 enhancer downstream of statin-YAP signaling that promotes the EndMT process. Thus, inhibition of any component of the GGTase-RhoA-YAP-SRY box transcription factor 9 (SOX9) signaling axis was shown to rescue EndMT-associated endothelial dysfunction both in vitro and in vivo, especially under diabetic conditions. Overall, our study reveals an epigenetic modulatory role for simvastatin in repressing EndMT to confer protection against endothelial dysfunction.

Cardiovascular Toxicities Associated with Tyrosine Kinase Inhibitors.

PURPOSE OF REVIEW: To provide a detailed overview of cardiovascular adverse events associated with the use of tyrosine kinase inhibitors across different tumor types. RECENT FINDINGS: Despite an undeniable survival advantage of tyrosine kinase inhibitors (TKIs) in patients with hematologic or solid malignancies, the accompanying off-target cardiovascular adverse events can be life-threatening. In patients with B cell malignancies, the use of Bruton tyrosine kinase inhibitors has been associated with atrial and ventricular arrhythmias, as well as hypertension. Cardiovascular toxic profiles are heterogeneous among the several approved breakpoint cluster region (BCR)-ABL TKIS. Notably, imatinib might be cardioprotective. Vascular endothelial growth factor TKIs, constituting the central axis in the treatment of several solid tumors, including renal cell carcinoma and hepatocellular carcinoma, have strongly been associated with hypertension and arterial ischemic events. Epidermal growth factor TKIs as therapy for advanced non-small cell lung cancer (NSCLC) have been reported to be infrequently associated with heart failure and QT prolongation. While tyrosine kinase inhibitors have been demonstrated to increase overall survival across different types of cancers, special consideration should be given to cardiovascular toxicities. High-risk patients can be identified by undergoing a comprehensive workup at baseline.

Biodegradable external wrapping promotes favorable adaptation in an ovine vein graft model.

Vein grafts, the most commonly used conduits in multi-vessel coronary artery bypass grafting surgery, have high intermediate- and long-term failure rates. The abrupt and marked increase in hemodynamic loads on the vein graft is a known contributor to failure. Recent computational modeling suggests that veins can more successfully adapt to an increase in mechanical load if the rate of loading is gradual. Applying an external wrap or support at the time of surgery is one way to reduce the transmural load, and this approach has improved performance relative to an unsupported vein graft in several animal studies. Yet, a clinical trial in humans has shown benefits and drawbacks, and mechanisms by which an external wrap affects vein graft adaptation remain unknown. This study aims to elucidate such mechanisms using a multimodal experimental and computational data collection pipeline. We quantify morphometry using magnetic resonance imaging, mechanics using biaxial testing, hemodynamics using computational fluid dynamics, structure using histology, and transcriptional changes using bulk RNA-sequencing in an ovine carotid-jugular interposition vein graft model, without and with an external biodegradable wrap that allows loads to increase gradually. We show that a biodegradable external wrap promotes luminal uniformity, physiological wall shear stress, and a consistent vein graft phenotype, namely, it prevents over-distension, over-thickening, intimal hyperplasia, and inflammation, and it preserves mechanotransduction. These mechanobiological insights into vein graft adaptation in the presence of an external support can inform computational growth and remodeling models of external support and facilitate design and manufacturing of next-generation external wrapping devices. STATEMENT OF SIGNIFICANCE: External mechanical support is emerging as a promising technology to prevent vein graft failure following coronary bypass graft surgery. While variants of this technology are currently under investigation in clinical trials, the fundamental mechanisms of adaptation remain poorly understood. We employ an ovine carotid-jugular interposition vein graft model, with and without an external biodegradable wrap to provide mechanical support, and probe vein graft adaptation using a multimodal experimental and computational data collection pipeline. We quantify morphometry using magnetic resonance imaging, mechanics using biaxial testing, fluid flow using computational fluid dynamics, vascular composition and structure using histology, and transcriptional changes using bulk RNA sequencing. We show that the wrap mitigates vein graft failure by promoting multiple adaptive mechanisms (across biological scales).

HMOX1 Genetic Polymorphisms Display Ancestral Diversity and May Be Linked to Hypertensive Disorders in Pregnancy.

Racial disparity exists for hypertensive disorders in pregnancy (HDP), which leads to disparate morbidity and mortality worldwide. The enzyme heme oxygenase-1 (HO-1) is encoded by HMOX1, which has genetic polymorphisms in its regulatory region that impact its expression and activity and have been associated with various diseases. However, studies of these genetic variants in HDP have been limited. The objective of this study was to examine HMOX1 as a potential genetic contributor of ancestral disparity seen in HDP. First, the 1000 Genomes Project (1 KG) phase 3 was utilized to compare the frequencies of alleles, genotypes, and estimated haplotypes of guanidine thymidine repeats (GTn; containing rs3074372) and A/T SNP (rs2071746) among females from five ancestral populations (Africa, the Americas, Europe, East Asia, and South Asia, N = 1271). Then, using genomic DNA from women with a history of HDP, we explored the possibility of HMOX1 variants predisposing women to HDP (N = 178) compared with an equivalent ancestral group from 1 KG (N = 263). Both HMOX1 variants were distributed differently across ancestries, with African women having a distinct distribution and an overall higher prevalence of the variants previously associated with lower HO-1 expression. The two HMOX1 variants display linkage disequilibrium in all but the African group, and within EUR cohort, LL and AA individuals have a higher prevalence in HDP. HMOX1 variants demonstrate ancestral differences that may contribute to racial disparity in HDP. Understanding maternal genetic contribution to HDP will help improve prediction and facilitate personalized approaches to care for HDP.

Cannabinoid receptor 1 antagonist genistein attenuates marijuana-induced vascular inflammation.

Epidemiological studies reveal that marijuana increases the risk of cardiovascular disease (CVD); however, little is known about the mechanism. Δ9-tetrahydrocannabinol (Δ9-THC), the psychoactive component of marijuana, binds to cannabinoid receptor 1 (CB1/CNR1) in the vasculature and is implicated in CVD. A UK Biobank analysis found that cannabis was an risk factor for CVD. We found that marijuana smoking activated inflammatory cytokines implicated in CVD. In silico virtual screening identified genistein, a soybean isoflavone, as a putative CB1 antagonist. Human-induced pluripotent stem cell-derived endothelial cells were used to model Δ9-THC-induced inflammation and oxidative stress via NF-κB signaling. Knockdown of the CB1 receptor with siRNA, CRISPR interference, and genistein attenuated the effects of Δ9-THC. In mice, genistein blocked Δ9-THC-induced endothelial dysfunction in wire myograph, reduced atherosclerotic plaque, and had minimal penetration of the central nervous system. Genistein is a CB1 antagonist that attenuates Δ9-THC-induced atherosclerosis.

An evidence appraisal of heart organoids in a dish and commensurability to human heart development in vivo.

Stem-cell derived in vitro cardiac models have provided profound insights into mechanisms in cardiac development and disease. Efficient differentiation of specific cardiac cell types from human pluripotent stem cells using a three-step Wnt signaling modulation has been one of the major discoveries that has enabled personalized cardiovascular disease modeling approaches. Generation of cardiac cell types follow key development stages during embryogenesis, they intuitively are excellent models to study cardiac tissue patterning in primitive cardiac structures. Here, we provide a brief overview of protocols that have laid the foundation for derivation of stem-cell derived three-dimensional cardiac models. Further this article highlights features and utility of the models to distinguish the advantages and trade-offs in modeling embryonic development and disease processes. Finally, we discuss the challenges in improving robustness in the current models and utilizing developmental principles to bring higher physiological relevance. In vitro human cardiac models are complimentary tools that allow mechanistic interrogation in a reductionist way. The unique advantage of utilizing patient specific stem cells and continued improvements in generating reliable organoid mimics of the heart will boost predictive power of these tools in basic and translational research.

G3bp1 - microRNA-1 axis regulates cardiomyocyte hypertrophy.

Adaptation of gene expression is one of the most fundamental response of cardiomyocytes to hypertrophic stimuli. G3bp1, an RNA binding protein with site-specific endoribonuclease activity regulates the processing of pre-miR-1 stem-loop, and thus levels of cardiomyocyte -enriched mature miR-1. Here, we examine the role of G3bp1 in regulating gene expression in quiescent cardiomyocytes and those undergoing growth-factor induced hypertrophy. Further, we determine if these changes are facilitated through G3bp1-mediated regulation of miR-1 in these cardiomyocytes. Using isolated cardiomyocytes with knockdown of endogenous G3bp1, we performed high throughput RNA sequencing to determine the change in cardiac transcriptome. Then, using gain and loss of function approach for both, G3bp1 and miR-1, alone or in combination we examine the G3bp1-miR-1 signaling in regulating gene expression and Endothelin (ET-1) -induced cardiomyocyte hypertrophy. We show that knockdown of endogenous G3bp1 results in inhibition of genes involved in calcium handling, cardiac muscle contraction, action potential and sarcomeric structure. In addition, there is inhibition of genes that contribute to hypertrophic and dilated cardiomyopathy development. Conversely, an increase is seen in genes that negatively regulate the Hippo signaling, like Rassf1 and Arrdc3, along with inflammatory genes of TGF-ß and TNF pathways. Knockdown of G3bp1 restricts ET-1 induced cardiomyocyte hypertrophy. Interestingly, concurrent silencing of G3bp1 and miR-1 rescues the change in gene expression and inhibition of hypertrophy seen with knockdown of G3bp1 alone. Similarly, expression of exogenous G3bp1 reverses the miR-1 induced inhibition of gene expression. Intriguingly, expression of Gfp tagged G3bp1 results in perinuclear accumulations of G3bp1-Gfp, resembling Stress Granules. Based on our results, we conclude that G3bp1 through its regulation of mature miR-1 levels plays a critical role in regulating the expression of essential cardiac-enriched genes and those involved in development of cardiomyocyte hypertrophy.

Preoperative Computed Tomography Angiography Reveals Leaflet-Specific Calcification and Excursion Patterns in Aortic Stenosis.

BACKGROUND: Computed tomography-based evaluation of aortic stenosis (AS) by calcium scoring does not consider interleaflet differences in leaflet characteristics. Here, we sought to examine the functional implications of these differences. METHODS: We retrospectively reviewed the computed tomography angiograms of 200 male patients with degenerative calcific AS undergoing transcatheter aortic valve replacement and 20 male patients with normal aortic valves. We compared the computed tomography angiography (CTA)-derived aortic valve leaflet calcification load (AVLCCTA), appearance, and systolic leaflet excursion (LEsys) of individual leaflets. We performed computer simulations of normal valves to investigate how interleaflet differences in LEsys affect aortic valve area. We used linear regression to identify predictors of leaflet-specific calcification in patients with AS. RESULTS: In patients with AS, the noncoronary cusp (NCC) carried the greatest AVLCCTA (365.9 [237.3-595.4] Agatston unit), compared to the left coronary cusp (LCC, 278.5 [169.2-478.8] Agatston unit) and the right coronary cusp (RCC, 240.6 [137.3-439.0] Agatston unit; both P<0.001). However, LCC conferred the least LEsys (42.8° [38.8°-49.0°]) compared to NCC (44.8° [41.1°-49.78°], P=0.001) and RCC (47.7° [42.0°-52.3°], P<0.001) and was more often characterized as predominantly thickened (23.5%) compared to NCC (12.5%) and RCC (16.5%). Computer simulations of normal valves revealed greater reductions in aortic valve area following closures of NCC (-32.2 [-38.4 to -25.8]%) and RCC (-35.7 [-40.2 to -32.9]%) than LCC (-24.5 [-28.5 to -18.3]%; both P<0.001). By linear regression, the AVLCCTA of NCC and RCC, but not LCC, predicted LEsys (both P<0.001) in patients with AS. Both ostial occlusion and ostial height of the right coronary artery predicted AVLCCTA, RCC (P=0.005 and P=0.001). CONCLUSIONS: In male patients, the AVLCCTA of NCC and RCC contribute more to AS than that of LCC. LCC's propensity for noncalcific leaflet thickening and worse LEsys, however, should not be underestimated when using calcium scores to assess AS severity.