Cardiac Mesenchymal Cells Research Articles

Slow H2S-Releasing Donors and 3D Printable Arrays Cellular Models in Osteo-Differentiation of Mesenchymal Stem Cells for Personalized Therapies.

The effects of the hydrogen sulfide (H2S) slow-releasing donor, named GSGa, a glutathione-conjugate water-soluble garlic extract, on human mesenchymal stem cells (hMSCs) in both bidimensional (2D) and three-dimensional (3D) cultures were investigated, demonstrating increased expression of the antioxidant enzyme HO-1 and decreased expression of the pro-inflammatory cytokine interleukin-6 (IL-6). The administration of the H2S donor can therefore increase the expression of antioxidant enzymes, which may have potential therapeutic applications in osteoarthritis (OA). Moreover, GSGa was able to promote the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), but not of cardiac mesenchymal stem cells (cMSCs) in a 2D culture system. This result highlights the varying sensitivity of hMSCs to the H2S donor GSGa, suggesting that the induction of osteogenic differentiation in stem cells by chemical factors is dependent on the tissue of origin. Additionally, a 3D-printable mesenchymal stem cells-bone matrix array (MSCBM), designed to closely mimic the stiffness of bone tissue, was developed to serve as a versatile tool for evaluating the effects of drugs and stem cells on bone repair in chronic diseases, such as OA. We demonstrated that the osteogenic differentiation process in cMSCs can be induced just by simulating bone stiffness in a 3D system. The expression of osteocalcin, RUNX2, and antioxidant enzymes was also assessed after treating MSCs with GSGa and/or increasing the stiffness of the culture environment. The printability of the array may enable better customization of the cavities, enabling an accurate replication of real bone defects. This could optimize the BM array to mimic bone defects not only in terms of stiffness, but also in terms of shape. This culture system may enable a rapid screening of antioxidant and anti-inflammatory compounds, facilitating a more personalized approach to regenerative therapy.

Differentiation, Metabolism, and Cardioprotective Secretory Functions of Human Cardiac Stromal Cells from Ischemic and Endocarditis Patients.

This study investigates the characteristics of cardiac mesenchymal stem cell-like cells (CMSCLCs) isolated from the right atrial appendage of human donors with ischemia and a young patient with endocarditis (NE-CMSCLCs). Typical CMSCLCs from ischemic heart patients were derived from coronary artery bypass grafting procedures and compared against bone marrow mesenchymal stromal cells (BM-MSCs). NE-CMSCLCs had a normal immunophenotype, but exhibited enhanced osteogenic differentiation potential, rapid proliferation, reduced senescence, reduced glycolysis, and lower reactive oxygen species generation after oxidative stress compared with typical ischemic CMSCLCs. These differences suggest a unique functional status of NE-CMSCLCs, influenced by the donor health condition. Despite large variances in their paracrine secretome, NE-CMSCLCs retained therapeutic potential, as indicated by their ability to protect hypoxia/reoxygenation-injured human cardiomyocytes, albeit less effectively than typical CMSCLCs. This research describes a unique cell phenotype and underscores the importance of donor health status in the therapeutic efficacy of autologous cardiac cell therapy.

Podoplanin Positive Cell-derived Extracellular Vesicles Contribute to Cardiac Amyloidosis After Myocardial Infarction.

Amyloidosis is a major long-term complication of chronic disease; however, whether it represents one of the complications of post-myocardial infarction (MI) is yet to be fully understood. Using wild-type and knocked-out MI mouse models and characterizing in vitro the exosomal communication between bone marrow-derived macrophages and activated mesenchymal stromal cells (MSC) isolated after MI, we investigated the mechanism behind Serum Amyloid A 3 (SAA3) protein overproduction in injured hearts. Here, we show that amyloidosis occurs after MI and that amyloid fibers are composed of macrophage-derived SAA3 monomers. SAA3 overproduction in macrophages is triggered by exosomal communication from a subset of activated MSC, which, in response to MI, acquire the expression of a platelet aggregation-inducing type I transmembrane glycoprotein named Podoplanin (PDPN). Cardiac MSC PDPN+ communicate with and activate macrophages through their extracellular vesicles or exosomes. Specifically, MSC PDPN+ derived exosomes (MSC PDPN+ Exosomes) are enriched in SAA3 and exosomal SAA3 protein engages with Toll-like receptor 2 (TRL2) on macrophages, triggering an overproduction and impaired clearance of SAA3 proteins, resulting in aggregation of SAA3 monomers as rigid amyloid deposits in the extracellular space. The onset of amyloid fibers deposition alongside extra-cellular-matrix (ECM) proteins in the ischemic heart exacerbates the rigidity and stiffness of the scar, hindering the contractility of viable myocardium and overall impairing organ function. Using SAA3 and TLR2 deficient mouse models, we show that SAA3 delivered by MSC PDPN+ exosomes promotes post-MI amyloidosis. Inhibition of SAA3 aggregation via administration of a retro-inverso D-peptide, specifically designed to bind SAA3 monomers, prevents the deposition of SAA3 amyloid fibrils, positively modulates the scar formation, and improves heart function post-MI. Overall, our findings provide mechanistic insights into post-MI amyloidosis and suggest that SAA3 may be an attractive target for effective scar reversal after ischemic injury and a potential target in multiple diseases characterized by a similar pattern of inflammation and amyloid deposition. What is known? Accumulation of rigid amyloid structures in the left ventricular wall impairs ventricle contractility.After myocardial infarction cardiac Mesenchymal Stromal Cells (MSC) acquire Podoplanin (PDPN) to better interact with immune cells.Amyloid structures can accumulate in the heart after chronic inflammatory conditions. What information does this article contribute? Whether accumulation of cumbersome amyloid structures in the ischemic scar impairs left ventricle contractility, and scar reversal after myocardial infarction (MI) has never been investigated.The pathophysiological relevance of PDPN acquirement by MSC and the functional role of their secreted exosomes in the context of post-MI cardiac remodeling has not been investigated.Amyloid structures are present in the scar after ischemia and are composed of macrophage-derived Serum Amyloid A (SAA) 3 monomers, although mechanisms of SAA3 overproduction is not established. Here, we report that amyloidosis, a secondary phenomenon of an already preexisting and prolonged chronic inflammatory condition, occurs after MI and that amyloid structures are composed of macrophage-derived SAA3 monomers. Frequently studied cardiac amyloidosis are caused by aggregation of immunoglobulin light chains, transthyretin, fibrinogen, and apolipoprotein in a healthy heart as a consequence of systemic chronic inflammation leading to congestive heart failure with various types of arrhythmias and tissue stiffness. Although chronic MI is considered a systemic inflammatory condition, studies regarding the possible accumulation of amyloidogenic proteins after MI and the mechanisms involved in that process are yet to be reported. Here, we show that SAA3 overproduction in macrophages is triggered in a Toll-like Receptor 2 (TLR2)-p38MAP Kinase-dependent manner by exosomal communication from a subset of activated MSC, which, in response to MI, express a platelet aggregation-inducing type I transmembrane glycoprotein named Podoplanin. We provide the full mechanism of this phenomenon in murine models and confirm SAA3 amyloidosis in failing human heart samples. Moreover, we developed a retro-inverso D-peptide therapeutic approach, "DRI-R5S," specifically designed to bind SAA3 monomers and prevent post-MI aggregation and deposition of SAA3 amyloid fibrils without interfering with the innate immune response.

Neonatal Cardiac Mesenchymal Stromal Cells Promote Recovery of Infarcted Myocardium through CD44 Mediated FoxP3+ T-Regulatory Cells after Vascular Infusion

Intravenous infusion has been used as the method of cell delivery in many preclinical studies as well as in some early clinical trials. Among its advantages are broad distribution, ability to handle a large-volume infusion, and ease of access. Progenitor cells used in cell-based therapy act through their secretomes, rather than their ability to differentiate into lineage-specific cell type. Since not all progenitor cells have similar secretome potency, the innate abilities of the secretome of cells used in clinical trials will obviously dictate their effectiveness. We previously found that cardiac neonatal mesenchymal stromal cells (nMSCs) are more effective in repairing the infarcted myocardium compared to adult mesenchymal stromal cells (aMSCs) due to their robust secretome (Sharma et al Circulation Research 120:816–834, 2017). In this study, we explored the efficacy of intravenous (IV) delivery of nMSCs for myocardial recovery. Six-week-old male Brown Norway rats underwent acute MI by ligation of the left anterior descending artery, followed by IV infusion of cell dose 5 × 106 nMSCs/rat body weight (kg) or saline on days 0 and 5. We found that cardiac parameters in the rodent ischemia model improved 1 month after nMSCs infusion, and the result is comparable with the intramyocardial injection of nMSCs. Tracking the infused cells in target organ revealed that their movement after IV delivery was mediated by the cell surface receptor CD44. Systemic injection of nMSCs stimulated immunomodulatory responses specifically by increasing FoxP3+ T-regulatory cell influenced anti-inflammatory macrophages (M2) in heart. These data demonstrate that nMSCs promote immunogenic tolerance via CD44-driven T-reg/M2 stimulation that helps nMSCs for longer viability in the injured myocardium for better functional recovery. Our data also demonstrate a rationale for a clinical trial of IV infusion of nMSCs to promote cardiac function improvement in the ischemic patients.Graphical

Cardiomyocyte-stromal cell interplay modulates the pathogenesis of arrhythmogenic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Transnational Research Projects on Cardiovascular Diseases Background Arrhythmogenic Cardiomyopathy (ACM) is an inherited heart disorder characterized by a high incidence of sudden death at young age. Mutations linked to ACM occur primarily in desmosomal genes (e.g. PKP2) [1]. Different cell types individually contribute to set the ACM phenotype with either functional abnormalities (cardiomyocytes; CM) [2]; or fibro-fatty substitution (cardiac mesenchymal stromal cells; cMSC) [3]. The relative contribution of the different cell type derangements to determine disease evolution and electrical instability is still unclear. Purpose We hypothesize that the use of a multicellular cardiac system, modelling the functional interaction between CM and cMSC, will allow the understanding of the relative contribution of the different cell types to the ACM phenotypes. Methods Primary cMSC (carrier of the PKP2 mutation c.2013delC) have been collected from a right ventricle biopsy sample; control cMSC obtained from a biobank. iPSC reprogrammed from the same ACM patient and the isogenic line in which the PKP2 mutation was corrected [4] were used. Cardiac cocultures (cc) were assembled by combining 85% iPSC-CM and 15% primary cMSC (as in Figure 1A), either mutated or control, in different combination (as in Figure 1B). Fibro-fatty accumulation have been evaluated by immunofluorescence analysis. Movies of contracting clusters have been collected and analysed by the MUSCLEMOTION tool [5]. Cell-cell communication was studied in silico by InterCellar analysis [6] on the single culture transcriptomes. The assessment of the paracrine interactions was performed on the cc secretome by Olink technology. Results Immunofluorescence analysis highlighted that ACM cc (cc 4) accumulate more lipids and collagen than healthy control (HC) ones (cc 1). Since intermediate fibro-fatty levels were observed in ‘mixed cc’ (cc 2 and 3), we conclude that ACM iPSC-CM are able to influence fibro-adipo-commitment of cMSC. Contraction studies showed a high propensity for cc monolayers which include ACM iPSC-CM (cc3 and cc4) to display arrhythmic events. An increase in the percentage of arrhythmic events was triggered when the ACM cMSC were replacing HC cMSC, indicating that ACM cMSC can affect iPSC-CM rhythm. The most abundant ligand-receptor couplets regarded cell-cell adhesion, cell-matrix coupling, cell differentiation and inflammation. Differential abundance between the four cc was observed mainly for secreted factors involved in cardiac fibrosis, inflammation, adipogenesis / lipid metabolism and heart failure. In particular, DLK-1, secreted only by HC CM, is validated as novel inhibitor of ACM fibro-adipose differentiation. Conclusion Overall, our novel simple multicellular ACM cell model can recapitulate different phenotypes of ACM and contributed to understand the relative contribution of the different cell types to ACM features (e.g. fibro-adipose replacement, contractile defects and proarrhythmic events).

Stem cell exosomes in the pathophysiology of cardiovascular diseases

This study focused on the current state of the therapeutic potential of extracellular vesicles, which depends on the methods of their isolation and composition and the characteristics of the vesicular and nonvesicular components. Myocardial damage, particularly as a result of acute myocardial infarction, leads to irreversible death of cardiomyocytes and sarcomeres and ultimately to heart failure. The adult heart has limited regenerative capacity; therefore, stimulation of endogenous repair and regenerative potentials using cell therapy has potential. Moreover, the benefit from the injection of stem cells and progenitor cells into the damaged myocardium is mediated by the factors they secrete. In particular, exosomes, nanosized secreted extracellular vesicles of endosomal origin, have become key signaling organelles in intercellular communication and are currently considered key regenerative components of the secretome of stem and progenitor cells. Exosomes released from cardiac embryonic and mesenchymal stem cells, resident stem and progenitor cells (including a specific subgroup of cardiosphere cells), induced pluripotent stem cells, and cardiomyocytes isolated from these cells have cardioprotective, immunomodulatory, and reparative abilities. The use of exosomes in the targeted transport of drugs in lipid-like nanocontainers and extracellular vesicles is another promising area. Because artificial drug carriers, including liposomes and lipid-based nanoparticles, are limited by potential toxicity, immunogenicity, and inability to target specific organs, exosomes hold good promise as potential drug carriers. Compounds can be transported both inside exosomes and on their surface. Secreted extracellular vesicles, particularly exosomes, can be considered a key functional component of the secretome of stem cells and cardiogenic progenitor cells (mesenchymal stem cells, endogenous cardiac progenitor cells, cardiospheres, bone marrow embryonic stem cells, and bone marrow induced pluripotent stem cells). They have demonstrated therapeutic efficacy in preclinical models in the study of cardiovascular pathology.

Early Impairment of Paracrine and Phenotypic Features in Resident Cardiac Mesenchymal Stromal Cells after Thoracic Radiotherapy.

Radiotherapy-induced cardiac toxicity and consequent diseases still represent potential severe late complications for many cancer survivors who undergo therapeutic thoracic irradiation. We aimed to assess the phenotypic and paracrine features of resident cardiac mesenchymal stromal cells (CMSCs) at early follow-up after the end of thoracic irradiation of the heart as an early sign and/or mechanism of cardiac toxicity anticipating late organ dysfunction. Resident CMSCs were isolated from a rat model of fractionated thoracic irradiation with accurate and clinically relevant heart dosimetry that developed delayed dose-dependent cardiac dysfunction after 1 year. Cells were isolated 6 and 12 weeks after the end of radiotherapy and fully characterized at the transcriptional, paracrine, and functional levels. CMSCs displayed several altered features in a dose- and time-dependent trend, with the most impaired characteristics observed in those exposed in situ to the highest radiation dose with time. In particular, altered features included impaired cell migration and 3D growth and a and significant association of transcriptomic data with GO terms related to altered cytokine and growth factor signaling. Indeed, the altered paracrine profile of CMSCs derived from the group at the highest dose at the 12-week follow-up gave significantly reduced angiogenic support to endothelial cells and polarized macrophages toward a pro-inflammatory profile. Data collected in a clinically relevant rat model of heart irradiation simulating thoracic radiotherapy suggest that early paracrine and transcriptional alterations of the cardiac stroma may represent a dose- and time-dependent biological substrate for the delayed cardiac dysfunction phenotype observed in vivo.

Transplantation of induced pluripotent stem cells-derived cardiomyocytes combined with modified Taohong Siwu decoction improved heart repair after myocardial infarction

ObjectiveThis study aimed to study whether modified Taohong Siwu decoction (MTHSWD) combined with human induced pluripotent stem cells-derived cardiomyocytes (iPS-CMs) transplantation can promote cardiac function in myocardial infarction (MI) nude mouse model and explore its possible mechanism. MethodsThe MI mouse model was established by the ligation of left anterior descending coronary artery. After 4 weeks of gavage of MTHSWD combined with iPS-CMs transplantation, the changes in heart function of mice were examined by echocardiography. The histological changes were observed by Masson's trichrome staining. The survival and differentiation of transplanted cells were detected by double immunofluorescence staining of human nuclear antigen (HNA) and cardiac troponin T (cTnT). The number of c-kit-positive cells in the infarct area were evaluated by immunofluorescent staining. The levels of stromal cell-derived factor 1 (SDF-1), stem cell factor (SCF), vascular endothelial growth factor (VEGF) and basic fibroblast growth factor in infarcted myocardium tissues were detected by ELISA. ResultsMTHSWD combined with iPS-CMs transplantation can improve the heart function of MI mice, reduce the infarct size and collagen deposition in infarct area. By immunofluorescence double-label detection of HNA and cTnT, it was found that MTHSWD combined with iPS-CMs transplantation can improve the survival and maturation of iPS-CMs. In addition, MTHSWD combined with iPS-CMs transplantation can activate more endogenous c-kit positive cardiac mesenchymal cells, and significantly increase the content of SDF-1, SCF and VEGF in myocardial tissues. ConclusionsThe combination of MTHSWD with iPS-CMs transplantation promoted cardiac function of nude mice with MI by improving the survival and maturation of iPS-CMs in the infarct area, activating the endogenous c-kit positive cardiac mesenchymal cells, and increasing paracrine.

Review of electrospun microtube array membrane (MTAM)-a novel new class of hollow fiber for encapsulated cell therapy (ECT) in clinical applications.

Encapsulated cell therapy (ECT) shows significant potential for treating neurodegenerative disorders including Alzheimer's and Parkinson's, which currently lack curative medicines and must be managed symptomatically. This novel technique encapsulates functional cells with a semi-permeable membrane, providing protection while enabling critical nutrients and therapeutic substances to pass through. Traditional ECT procedures, on the other hand, pose difficulties in terms of cell survival and retrieval. We introduce the Microtube Array Membrane (MTAM), a revolutionary technology that solves these constraints, in this comprehensive overview. Microtube Array Membrane has distinct microstructures that improve encapsulated cells' long-term viability by combining the advantages of macro and micron scales. Importantly, the MTAM platform improves biosafety by allowing the entire encapsulated unit to be retrieved in the event of an adverse reaction. Our findings show that MTAM-based ECT has a great potential in a variety of illness situations. For cancer treatment, hybridoma cells secreting anti-CEACAM 6 antibodies inhibit triple-negative breast cancer cell lines for an extended period of time. In animal brain models of Alzheimer's disease, hybridoma cells secreting anti-pTau antibodies successfully reduce pTau buildup, accompanied by improvements in memory performance. In mouse models, MTAM-encapsulated primary cardiac mesenchymal stem cells dramatically improve overall survival and heart function. These findings illustrate the efficacy and adaptability of MTAM-based ECT in addressing major issues such as immunological isolation, cell viability, and patient safety. We provide new possibilities for the treatment of neurodegenerative illnesses and other conditions by combining the potential of ECT with MTAM. Continued research and development in this subject has a lot of promise for developing cell therapy and giving hope to people suffering from chronic diseases.

The role of charme in the phenotype and function of resident cardiac mesenchymal stromal cells

Abstract Background Charme is a murine long non-coding RNA with specific expression in striated muscles, presenting a human orthologue with 45% identity. Its depletion leads to incomplete muscle differentiation. Charme-/- mice display an altered cardiac phenotype with increased wall thickness and reduced chamber dimensions due to myocyte hyperplasia. Left ventricular dilatation and reduced fractional shortening are detected in aged Charme-/- mice. Embryonic myocardial architecture reveals aberrant compaction and ventricular hypotrabeculation, resembling some congenital cardiomyopathies. Cardiac mesenchymal stromal cells (CMSCs) play key roles in tissue homeostasis and pathophysiology, by maintaining the extracellular matrix and by paracrine action on all myocardial cells. Purpose To elucidate the phenotype, paracrine function, and myofibroblast differentiation capacity of resident CMSCs in the Charme-/- mouse model. Methods CMSCs were isolated from 5-week-old wild-type (WT) and Charme-/- mice by explant culture, pooling at least 4 different hearts per culture. Results Charme-/- CMSCs showed increased features of primitive phenotypes, such as enhanced spontaneous spheroid growth (123,6±11,9 vs 51,0±6,4 spheroids/well; N=8, p<0,0001) and clonogenesis efficiency (2,7±0,5-fold; N=7, p<0,05) compared to WT cells. Charme-/- CMSCs also showed increased migration ability (Charme-/-: 68,5±2,7% vs WT: 80,2±0,7% wound area; N=2). Flow cytometry identified a reduced proportion of lin-/Sca1+/CD90+ primitive mesenchymal cells in Charme-/- versus WT CMSCs (7,4±1,6% vs 56,9±6,5%; N=6, p<0,05). Western blot analysis on Charme-/- whole cardiac tissue showed reduced collagen I and collagen I/III protein ratio compared to WT hearts (0,17±0,03 vs 0,85±0,10 normalized OD; N=4, p<0,005). Stimulation with TGFb-1 resulted in lower expression of fibroblast activation markers compared to WT CMSCs, as assessed by immunofluorescence staining for aSMA (0,49±0,05 vs 0,76±0,10 mean fluorescence intensity; N=6-12, p<0,05) and collagen I/III mRNA expression ratio (1,3±0,1 vs 2,2±0,4 2^-DCt; N=3, p<0,01). The secretome of Charme-/- CMSCs revealed a general depletion in many cardioprotective cytokines, included in the KEGG term "PI3K-Akt signalling pathway" (FDR<0,0005) and classified in Gene Ontology categories of myoblast differentiation and fusion (GO:1901739, GO:1901741, GO:0045663, GO:0045661; FDR<0,05). In line with this, the secretome of TGFb1-stimulated Charme-/- CMSCs was less effective in sustaining cardiomyocyte survival versus the WT CMSC secretome (1,70±0,03 vs 1,90±0,04 normalized OD at 48h; N=5, p<0,005). Conclusions Charme-/- CMSCs show a less mature phenotype associated to reduced collagen I presence in situ, reduced activation and differentiation upon stimulation, and impaired cardioprotective paracrine functions, suggesting a key role of Charme in the physiology of the cardiac stroma, possibly mediating in part the altered cardiac phenotype of Charme-/- mice.

Stromal cell models of arrhythmogenic cardiomyopathy

Abstract Background Arrhythmogenic cardiomyopathy (ACM) is an inherited heart disease mainly associated with mutations in genes encoding cardiac desmosomes, most frequently Plakophilin-2 (PKP2). Primary cardiac mesenchymal stromal cells (CMSCs) were shown to contribute to the aberrant ACM cardiac remodeling based on their ability to differentiate into adipocytes and myofibroblasts, thus representing a useful in vitro model for the disease. The limitations associated with access to biopsies and finite passages in culture have been overcome by the advancement of stem cell technology, especially human induced pluripotent stem cells (hiPSCs) and their ability to differentiate towards cardiac stromal population. Specifically, CMSCs from hiPSCs provide a virtually unlimited cell sources that are genetically identical to patient cells of origin. Purpose The study compares hiPSC-derived stromal cells (hiPSC-D) and primary stromal cells (PRs), to explore the feasibility to use iPSC-D as an alternative in vitro model to study ACM. Methods PRs were isolated from ACM patients and healthy donors (HC). hiPSCs from a PKP2 mutated ACM patient (c.2013delC) and a sex/aged matched HC were used to produce iPSC-D. Flow cytometry analysis and specific differentiation induction (osteogenic, chondrogenic, adipogenic and pro-fibrotic) were performed to confirm mesenchymal lineage and multipotency. qRT-PCR and western blot analysis were performed to evaluate the expression of desmosomes, both gene and protein levels. Illumina transcriptomic profiling of both PRs and iPSC-D were compared and enriched pathways were identified by GSEA. Results Both PR and iPSC-D cells expressed mesenchymal surface markers and were able to differentiate towards osteogenic, chondrogenic, adipogenic and myofibroblast lineages. Desmosomal genes and proteins were expressed by both populations, showing a general trend toward lower expression of desmosomal markers in ACM compared to HC cells. Overall, higher expression of desmosomes was observed in iPSC-D stromal cells compared to their primary counterparts, independently on the genotype. As occurs for PRs, ACM iPSC-D exhibited an increased propensity to accumulate lipid droplets and collagen compared to HC cells. Moreover, both cell populations shared a highly similar transcriptomic profile, showing a significant linear correlation (R=0.85). Interestingly, PRs were enriched for genes associated with the immune response and differentiation processes, hinting to the hypothesis that an inflammatory stimulus received from the cardiac tissue might activate the innate immunity and drive the cell differentiation fates in the PRs. Conclusion(s) Both PR and iPSC-D cardiac stromal cells obtained from ACM patients can be used to model the disease, where the choice for the most suitable cell populations can be determined by the experimental strategy and/or the availability of human primary material.

Small extracellular vesicles from failing heart accelerate tumour growth

Abstract Background Heart failure (HF) is associated with an increased incidence of cancer independently of shared risk factors. The mechanism behind this link is not entirely clear. Purpose We aimed to test the hypothesis that cardiac extracellular vesicles (cEVs) contribute to the link between HF and cancer. In addition, we aimed to determine if heart failure (HF) therapy will reduce the tumour-promoting effects of HF. Methods We used a mouse model of heterotopic lung cancer tumours and post-myocardial infarction (MI) HF. To determine the role of cEVs in tumour growth, we focused on cardiac mesenchymal stromal cells (cMSCs). First, we isolated cMSCs from mice hearts 10d after MI or sham MI and purified cMSC-EVs from the conditioned medium using size exclusion chromatography. Then, we analyzed cMSC-EV characteristics, cargo, and neoplastic effects on lung cancer cells. We also used cMSC-EV transfer to assess EV biodistribution and its effect on tumour growth. Next, we tested the effects of EV depletion on tumour growth. Finally, we used spironolactone to determine if HF therapy would attenuate the harmful interaction between HF and cancer. Results Mice with HF developed larger lung tumours than sham-MI mice during 28 days of follow-up. Failing hearts, particularly cMSCs, produced twice more EVs with neoplastic properties than non-failing hearts (Fig-A). Proteomics analysis revealed unique protein profiles of cMSC-EVs from failing hearts (Fig-B). cMSC-EVs from the failing hearts harbored higher quantities of tumour-promoting cytokines such as periostin, osteopontin, vascular endothelial growth factor, interleukin-6 and tumour necrosis factor-alpha; and tumorigenic microRNAs (miR) such as miR-221 and mir-21. Transfer of labeled cMSC-EVs from the failing heart into the systemic circulation of tumour-bearing mice targeted tumour cells and accelerated tumour growth (Fig-C). Moreover, EV depletion reduced the tumour-promoting effects of HF, and adoptive transfer of cMSC-EVs from failing hearts accelerated tumour growth in mice during systemic EV depletion (Fig-D). Finally, we used spironolactone to determine if HF therapy would inhibit the tumour trophic effects of HF. Spironolactone attenuated LV dilatation and improved global longitudinal strain following MI. Subsequently, spironolactone treatment reduced the number of EVs secreted by cMSCs from failing hearts by 26% and reduced the accelerated tumour growth after MI and HF (Fig E). Notably, spironolactone treatment did not reduce the volume of the tumours in sham-MI mice, indicating that the anti-tumour effects of spironolactone were related to its effects on the faling heart. Conclusions Our results provide new insight into the link between heart failure and cancer. We show, for the first time, that cardiac extracellular vesicles promote tumour growth independently of other secreted factors. Moreover, heart failure therapy reduces the tumour-promoting effects of heart failure.

Transcriptome and methylome analyses of stromal cells from ACM patients reveal the additional role of alterations in mitochondrial homeostasis and chromatin organization in disease pathogenesis

Abstract Background Arrhythmogenic cardiomyopathy (ACM) is a rare genetic disorder of the heart, characterized by ventricular arrhythmias and contractile dysfunctions, which can cause sudden cardiac death and heart failure. Typically, the hallmarks of ACM ventricular myocardium are cardiomyocyte death, inflammation and fibro-adipose replacement, resulting in electrical and mechanical abnormalities of the tissue. Cardiac mesenchymal stromal cells (CMSC) participate to disease pathogenesis by differentiating towards adipocytes and myofibroblasts. Some altered pathways in ACM are known, but many pathogenetic molecular mechanisms are yet to be discovered. Purpose Our work aims to contribute to a comprehensive understanding of the pathogenic mechanism occurring in ACM, focusing on the molecular pathways underlying stromal cell involvement, through the functional validation of gene expression and epigenetic profile of ACM-CMSC. Methods We conducted total RNA transcriptome and DNA methylome analyses in ACM- and healthy control (HC)- CMSC to identify pathways differentially regulated in the two groups. We performed category enrichment and gene network analyses and we built transcript functional networks. To validate our findings, we measured the protein levels coded by selected genes differentially expressed by Western Blot analysis and we evaluated the relative pathways, such as mitochondria homeostasis, proliferation rate and epithelial-to-mesenchymal transition (EMT) through cytofluorimetric analyses. Results By transcriptomic analysis we found 529 genes differentially expressed; in particular, 327 genes were more expressed and 202 less expressed in ACM- vs HC-CMSC. Among those with the highest logFC and the lowest p value, we identified COX7C (implicated in mitochondrial respiration), S100A11 (involved in EMT) and CCND2 (one of the promoters of the cell cycle), whose protein expression was validated. Through the enrichment and gene network analysis we identified some pathways differentially regulated in ACM vs. HC. Some of these are known to be altered in ACM hearts, as matrix homeostasis and cell junction arrangement. Other pathways have never been associated to ACM, such as mitochondrial functioning and chromatin organization. By the DNA-methylation investigation, we identified 74 differentially methylated nucleotides and most of them were located on the mitochondrial genome. We also found that ACM-CMSC exhibited a greater number of mitochondria and a greater amount of mitochondrial reactive oxygen species than HC. Furthermore, ACM-CMSC showed a higher proliferation rate and a more pronounced EMT, compared to controls. Conclusions ACM-CMSC -omics revealed some new altered molecular pathways, not yet explored, which are relevant in the pathogenesis of the disease and may constitute novel targets for specific therapeutic approaches.

Cardiomyocyte - stromal cells interplay as a novel platform for mechanistic insights in arrhythmogenic cardiomyopathy

Abstract Background Arrhythmogenic Cardiomyopathy (ACM) is an inherited heart disorder characterized by a high incidence of sudden death at young age. Mutations linked to ACM occur primarily in desmosomal genes (e.g. PKP2) [1]. Different cell types individually contribute to set the ACM phenotype with either functional abnormalities (cardiomyocytes; CM) [2]; or fibro-fatty substitution (cardiac mesenchymal stromal cells; CMSC) [3]; these two cell types interact and show a reciprocal influence [4]. The relative contribution of the different cell type derangements to determine disease evolution and electrical instability is still unclear. Purpose Based on this evidence, we hypothesize that the use of a multicellular cardiac system, modelling the functional interaction between CM and CMSC, will allow the understanding of the relative contribution of the different cell types to the ACM phenotypes. Methods Primary stromal cells (carrier of the PKP2 mutation c.2013delC) have been collected from a right ventricle biopsy sample; control stromal cells obtained from a biobank. iPSC reprogrammed from the same ACM patient and the isogenic line in which the PKP2 mutation c.2013delC was corrected [5] were used. Cardiac cocultures (cc) were assembled by combining 85% iPSC-CM and 15% primary CMSC, either mutated or control, in different combination (as in Table 1). Movies of contracting clusters have been collected and analysed by the MUSCLEMOTION tool [6]. Fibro-fatty accumulation have been evaluated by immunofluorescence analysis by confocal microscopy. Results Immunofluorescence analysis highlighted that ACM cc (cc 4) accumulate more lipids and collagen than healthy control (HC) ones (cc 3). Since intermediate fibro-fatty levels were observed in ‘mixed cc’ (cc 1 and 4), we conclude that ACM iPSC-CM are able to influence fibro-adipo-commitment of CMSC. Contraction studies showed a high propensity for cc monolayers which include ACM iPSC-CM (cc1 and cc2) to display arrhythmic events. An increase in the percentage of arrhythmic events was triggered when the ACM CMSC were replacing HC CMSC, indicating that ACM CMSC can affect iPSC-CM rhythm. Conclusion Overall, our data confirm the importance of the cardiomyocytes and stromal cells interplay during ACM pathogenesis. Furthermore, our novel advanced ACM cell model can recapitulate different phenotypes of ACM and offers a unique opportunity for validating pharmacological therapies to modulate ACM-related characteristics (e.g. fibro-adipose replacement, contractile defects and proarrhythmic events).

Abstract 16391: Pro-Neoplastic Properties of Small Extracellular Vesicles From Failing Hearts

Background: Heart diseases are associated with an increased incidence of cancer independently of shared risk factors. The mechanism beyond this link is complex, unclear and limits our ability to develop effective therapies. We aimed to test the hypothesis that small cardiac extracellular vesicles (sEVs) contribute to the link between HF and cancer. Methods & Results: We used mouse models of heterotopic and orthotopic lung cancer and post-myocardial infarction (MI) heart failure (HF). sEVs were isolated by size exclusion chromatography. To determine the role of cardiac EVs in tumor growth, we focused on sEVs from cardiac mesenchymal stromal cells (cMSCs). cMSCs after MI secreted twice more sEVs, characterized with a unique proteome, compared with cMSCs from sham-MI ( Fig 1A ). cMSC-sEVs from post-MI HF harbored more tumor-promoting cytokines and microRNA (miR), such as periostin, osteopontin, IL-6, TNFα, galectin-3, and miR's 221 and 21. The pro-neoplastic effects of cMSC-sEVs on cancer cells were depended on cancer type, with a marked increase in proliferation and migration of lung and colon cancer cells but only a modest increase with more malignant triple-negative breast and melanoma cancer cells. Next, we inoculated lung cancer cells into mice and found that post-MI HF accelerated tumor growth. Furthermore, adoptive transfer of cMSC-sEVs from failing hearts accelerated tumor growth with and without systemic EV depletion ( Fig 1B ). Finally, we found that spironolactone mitigated the neoplastic effects of HF, attenuated tumor growth ( Fig 1C ), and reduced the number of cMSC-sEVs by 26%. Conclusions: We show, for the first time, that cardiac extracellular vesicles from post-MI failing heart harbor pro-neoplastic properties and promote tumor growth independently of other secreted factors. Spironolactone reduces the number of cardiac extracellular vesicles and the pro-neoplastic effects of post-MI heart failure.

Urokinase-Type Plasminogen Activator Receptor Regulates Prosurvival and Angiogenic Properties of Cardiac Mesenchymal Stromal Cells.

One of the largest challenges to the implementation of cardiac cell therapy is identifying selective reparative targets to enhance stem/progenitor cell therapeutic efficacy. In this work, we hypothesized that such a target could be an urokinase-type plasminogen activator receptor (uPAR)-a glycosyl-phosphatidyl-inositol-anchored membrane protein, interacting with urokinase. uPAR is able to form complexes with various transmembrane proteins such as integrins, activating intracellular signaling pathway and thus regulating multiple cell functions. We focused on studying the CD117+ population of cardiac mesenchymal progenitor cells (MPCs), expressing uPAR on their surface. It was found that the number of CD117+ MPCs in the heart of the uPAR-/- mice is lower, as well as their ability to proliferate in vitro compared with cells from wild-type animals. Knockdown of uPAR in CD117+ MPCs of wild-type animals was accompanied by a decrease in survival rate and Akt signaling pathway activity and by an increase in the level of caspase activity in these cells. That suggests the role of uPAR in supporting cell survival. After intramyocardial transplantation of uPAR(-) MPCs, reduced cell retention and angiogenesis stimulation were observed in mice with myocardial infarction model compared to uPAR(+) cells transplantation. Taken together, the present results appear to prove a novel mechanism of uPAR action in maintaining the survival and angiogenic properties of CD117+ MPCs. These results emphasize the importance of the uPAR as a potential pharmacological target for the regulation of reparative properties of myocardial mesenchymal progenitor cells.

Patient-specific primary and pluripotent stem cell-derived stromal cells recapitulate key aspects of arrhythmogenic cardiomyopathy

Primary cardiac mesenchymal stromal cells (C-MSCs) can promote the aberrant remodeling of cardiac tissue that characterizes arrhythmogenic cardiomyopathy (ACM) by differentiating into adipocytes and myofibroblasts. These cells’ limitations, including restricted access to primary material and its manipulation have been overcome by the advancement of human induced pluripotent stem cells (hiPSCs), and their ability to differentiate towards the cardiac stromal population. C-MSCs derived from hiPSCs make it possible to work with virtually unlimited numbers of cells that are genetically identical to the cells of origin. We performed in vitro experiments on primary stromal cells (Primary) and hiPSC-derived stromal cells (hiPSC-D) to compare them as tools to model ACM. Both Primary and hiPSC-D cells expressed mesenchymal surface markers and possessed typical MSC differentiation potentials. hiPSC-D expressed desmosomal genes and proteins and shared a similar transcriptomic profile with Primary cells. Furthermore, ACM hiPSC-D exhibited higher propensity to accumulate lipid droplets and collagen compared to healthy control cells, similar to their primary counterparts. Therefore, both Primary and hiPSC-D cardiac stromal cells obtained from ACM patients can be used to model aspects of the disease. The choice of the most suitable model will depend on experimental needs and on the availability of human source samples.

Interplay between BMP2 and Notch signaling in endothelial-mesenchymal transition: implications for cardiac fibrosis.

The endothelial-to-mesenchymal transition (EndoMT) is a crucial process in cardiovascular development and disorders. Cardiac fibrosis, characterized by excessive collagen deposition, occurs in heart failure, leading to the organ remodeling. Embryonic signaling pathways such as bone morphogenetic protein 2 (BMP2) and Notch are involved in its regulation. However, the interplay between these pathways in EndoMT remains unclear. This study investigates the downstream targets of Notch and BMP2 and their effect on EndoMT markers in cardiac mesenchymal cells (CMCs) and human umbilical vein endothelial cells (HUVECs). We transduced cell cultures with vectors carrying intracellular domain of NOTCH1 (NICD) and/or BMP2 and evaluated gene expression and activation of EndoMT markers. The results suggest that the Notch and BMP2 signaling pathways have common downstream targets that regulate EndoMT. The activation of BMP2 and Notch is highly dependent on cell type, and co-cultivation of CMCs and HUVECs produced opposing cellular responses to target gene expression and α-smooth muscle actin (α-SMA) synthesis. The balance between Notch and BMP2 signaling determines the outcome of EndoMT and fibrosis in the heart. The study's findings highlight the need for further research to understand the interaction between Notch and BMP2 in the heart and develop new therapeutic strategies for treating cardiac fibrosis.

Store-Operated Ca2+ Entry as a Putative Target of Flecainide for the Treatment of Arrhythmogenic Cardiomyopathy.

Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder that may lead patients to sudden cell death through the occurrence of ventricular arrhythmias. ACM is characterised by the progressive substitution of cardiomyocytes with fibrofatty scar tissue that predisposes the heart to life-threatening arrhythmic events. Cardiac mesenchymal stromal cells (C-MSCs) contribute to the ACM by differentiating into fibroblasts and adipocytes, thereby supporting aberrant remodelling of the cardiac structure. Flecainide is an Ic antiarrhythmic drug that can be administered in combination with β-adrenergic blockers to treat ACM due to its ability to target both Nav1.5 and type 2 ryanodine receptors (RyR2). However, a recent study showed that flecainide may also prevent fibro-adipogenic differentiation by inhibiting store-operated Ca2+ entry (SOCE) and thereby suppressing spontaneous Ca2+ oscillations in C-MSCs isolated from human ACM patients (ACM C-hMSCs). Herein, we briefly survey ACM pathogenesis and therapies and then recapitulate the main molecular mechanisms targeted by flecainide to mitigate arrhythmic events, including Nav1.5 and RyR2. Subsequently, we describe the role of spontaneous Ca2+ oscillations in determining MSC fate. Next, we discuss recent work showing that spontaneous Ca2+ oscillations in ACM C-hMSCs are accelerated to stimulate their fibro-adipogenic differentiation. Finally, we describe the evidence that flecainide suppresses spontaneous Ca2+ oscillations and fibro-adipogenic differentiation in ACM C-hMSCs by inhibiting constitutive SOCE.

A Review of Therapeutic Strategies against Cardiac Fibrosis: From Classical Pharmacology to Novel Molecular, Epigenetic, and Biotechnological Approaches.

Cardiovascular diseases are the first cause of death worldwide, with a heavy social and economic impact. They include a wide range of pathological conditions, among which cardiac fibrosis represents a common pathogenetic hallmark. The fibrotic process is driven by cardiac mesenchymal stromal cells, namely fibroblasts, which become activated, proliferate, and differentiate into myofibroblasts in response to several stimuli, in the end secreting extracellular matrix proteins, and mediating cardiac tissue remodelling and stiffening. A specific therapy for the exclusive treatment of cardiac fibrosis is still lacking. Given the growing quest for reducing the burden of cardiovascular diseases, there is increasing interest in the search for new effective anti-fibrotic therapies. In this review, we will briefly summarize the limited pharmacological therapies known to act, at least in part, against cardiac fibrosis. Then we will present novel potential active molecules, molecular targets, and biotechnological approaches emerged in the last decade, as possible future therapeutic strategies for cardiac fibrosis, with a specific focus on targeting fibroblast activation and function.