Myocardial infarction (MI) remains a major global health challenge, with endothelial cell function playing a crucial role in its progression. Advances in single-cell RNA sequencing (scRNA-seq) have enhanced our understanding of MI pathogenesis. This study aims to identify key genes within endothelial cells using scRNA-seq data and validate them through microarray data and in vivo models elucidate their role in the progression of MI. ScRNA-seq and microarray datasets relevant to MI were obtained from the GEO database. The Seurat package was used for data pre-processing and marker gene identification. Endothelial cell subpopulations were characterised using the hdWGCNA package, while intercellular interactions with fibroblasts were assessed using CellChat. Key genes were identified using comprehensive bioinformatics techniques such as scCODE, FindMarkers and protein-protein interaction (PPI) analysis, with validation from microarray data and in vivo experiments (WB, qPCR, immunofluorescence) in the model of MI. The analysis via scRNA-seq revealed 16 distinct cell clusters encompassing 7 unique cell types. Endothelial cells were categorized into 8 subpopulations by hdWGCNA; notably, Endothelial Cells-2 exhibited significant interactions with fibroblasts mediated by PDGF, PROS, and GAS signaling pathways. Integration of hdWGCNA, scCODE and FindMarkers, 10 key genes were identified, which were subsequently refined to DBP, NR1D1, and TEF following PPI analysis. These genes demonstrated marked downregulation the progression of MI, as confirmed by subsequent in vivo experiments. This study highlights the crucial roles of DBP, NR1D1, and TEF in MI development, providing a basis for future research on endothelial cell function in cardiovascular disease.

Diabetic cardiomyopathy (DbCM) is recognised as a key mediator and determinant of heart failure (HF), particularly HF with preserved ejection fraction (HFpEF). Improved understanding of mechanisms underlying transition from early-stage DbCM to HFpEF will inform innovative evidence-based treatment approaches, which are urgently required to alleviate increasing disease burden. This study aimed to determine whether inhibition of neprilysin activity by Sacubitril/Valsartan in both experimental and clinical DbCM attenuates adverse remodelling through promotion of cardioprotective signalling.

Sacubitril/Valsartan effectively reduced plasma neprilysin activity in both diabetic patients with pre-clinical HFpEF from the PARABLE trial (baseline (Val n = 25; Sac/Val n = 35) and 3 months after treatment (Val n = 21/25; Sac/Val n = 33/35)) and DbCM (high-fat diet and streptozotocin) mice. Plasma neprilysin activity at baseline was correlated with worsening cardiac performance at 18 months indicated by left atrial stiffness index in patients (n = 44/60), whilst diastolic dysfunction and pathological remodelling in DbCM mice were improved by Sacubitril/Valsartan, but not Valsartan. snRNA-sequencing showed that progressive experimental DbCM is characterised by chronic low-grade inflammation, reflected by increased infiltration of pro-inflammatory monocytes (Ccr2+ Ly6chi) and reduction in MHC-II macrophages, which was prevented by Sacubitril/Valsartan. Informatics analysis implicated IRF7 as a central mediator of Sacubitril/Valsartan-induced immunomodulation in DbCM, whilst treatment of M2-like pro-repair macrophages with the neprilysin inhibitor, LBQ657 and Valsartan suppressed glucose-induced IRF7 expression and paracrine activation of cardiac fibroblast differentiation in vitro.

Immune cells are significantly involved in DbCM progression, impacting myocardial homeostasis and HF progression. Neprilysin inhibition by Sacubitril/Valsartan improved adverse cardiac remodelling in experimental DbCM through direct regulation of inflammation, highlighting immunomodulation as a novel mechanism underlying established its cardioprotective actions.

Macrophages are a cell type that are known to play dynamic roles in acute and progressive pathology. They are highly attuned to their microenvironments throughout maturation, tailoring their functional responses according to the specific tissues in which they reside and their developmental origin. Cardiac macrophages (cMacs) have emerged as focal points of interest for their interactions with the unique electrical and mechanical stimuli of the heart, as well as for their role in maintaining cardiac homeostasis. Through an in-depth analysis of their origin, lineage, and functional significance, this review aims to shed light on cMacs' distinct contributions to both normal physiological maintenance as well as disease progression. Central to our discussion is the comparison of cMac characteristics between mouse and human models, highlighting current challenges and proposing novel experimental tools for deciphering cMac function within the intricate human cardiac microenvironments based on current murine studies. Our review offers valuable insights for identifying novel therapeutic targets and interventions tailored to the distinct roles of these immune cells in cardiovascular diseases (CVDs).

Aging is associated with the accumulation of senescent cells, which are triggered by tissue injury response and often escape clearance by the immune system. The specific traits and diversity of these cells in aged tissues, along with their effects on the tissue microenvironment, remain largely unexplored. Despite the advances in single-cell and spatial omics technologies to understand complex tissue architecture, senescent cell populations are often neglected in general analysis pipelines due to their scarcity and the technical bias in current omics toolkits. Here we used the physical properties of tissue to enrich the age-associated fibrotic niche and subjected them to single-cell RNA sequencing and single-nuclei ATAC sequencing (ATAC-seq) analysis and named this method fibrotic niche enrichment sequencing (FiNi-seq). Fibrotic niche of the tissue was selectively enriched based on its resistance to enzymatic digestion, enabling quasi-spatial analysis. We profiled young and old livers of male mice using FiNi-seq, discovered Wif1- and Smoc1-producing mesenchymal cell populations showing senescent phenotypes, and investigated the early immune responses within this fibrotic niche. Finally, FiNi-ATAC-seq revealed age-associated epigenetic changes enriched in fibrotic niche cells. Thus, our quasi-spatial, single-cell profiling method allows the detailed analysis of initial aging microenvironments, providing potential therapeutic targets for aging prevention.

Matrix-derived biophysical cues are known to regulate the activation of fibroblasts and their subsequent transdifferentiation into myofibroblasts1-6, but whether modulation of these signals can suppress fibrosis in intact tissues remains unclear, particularly in the cardiovascular system7-10. Here we demonstrate across multiple scales that inhibition of matrix mechanosensing in persistently activated cardiac fibroblasts potentiates-in concert with soluble regulators of the TGFβ pathway-a robust transcriptomic, morphological and metabolic shift towards quiescence. By conducting a meta-analysis of public human and mouse single-cell sequencing datasets, we identify the focal-adhesion-associated tyrosine kinase SRC as a fibroblast-enriched mechanosensor that can be targeted selectively in stromal cells to mimic the effects of matrix softening in vivo. Pharmacological inhibition of SRC by saracatinib, coupled with TGFβ suppression, induces synergistic repression of key profibrotic gene programs in fibroblasts, characterized by a marked inhibition of the MRTF-SRF pathway, which is not seen after treatment with either drug alone. Importantly, the dual treatment alleviates contractile dysfunction in fibrotic engineered heart tissues and in a mouse model of heart failure. Our findings point to joint inhibition of SRC-mediated stromal mechanosensing and TGFβ signalling as a potential mechanotherapeutic strategy for treating cardiovascular fibrosis.

Cardiac fibroblasts (CF) are key players after myocardial infarction (MI), but their signaling is only incompletely understood. Here we report a first secretome atlas of CF in control (cCF) and post-MI mouse hearts (miCF), combining a rapid cell isolation technique with SILAC and click chemistry. In CF, numerous paracrine factors involved in immune homeostasis are identified. Comparing secretome, transcriptome (SLAMseq), and cellular proteome disclose protein turnover. In miCF at day 5 post-MI, significantly upregulated proteins include SLIT2, FN1, and CRLF1 in mouse and human samples. Comparing the miCF secretome at days 3 and 5 post-MI reveals the dynamic nature of protein secretion. Specific in-vivo labeling of miCF proteins via biotin ligase TurboID using the POSTN promotor mirrors the in-vitro data. In summary, we identify numerous paracrine factors specifically secreted from CF in mice and humans. This secretome atlas may lead to new biomarkers and/or therapeutic targets for the activated CF.

Despite recent advances in pre-clinical research on cardiac remodeling following myocardial infarction (MI), the precise molecular pathways remain poorly understood and effective therapies for heart failure are still delayed in development. Aged animal models may more accurately reflect the clinical scenario, as aging alters the cellular identities and impedes cardiac repair. In this manuscript, we investigated the expression profile of mouse cardiac fibroblasts following myocardial infarction, using both young and aged animals to enhance the translational significance. The initial studies aimed to identify fibroblast changes common to both young and old animals. Additionally, a group of young animals that underwent mesenchymal stem cells (MSC) therapy after MI surgery was included to help identify the molecular changes amenable to therapeutic modulation. The analysis uncovered Glioma- Pathogenesis Related Protein 1 (GLIPR1) activation during the post-MI maturation phase in a subset of myofibroblasts, localized to the infarct zone in young subjects and widespread throughout the ventricle in aged animals. Further investigations indicated that the inflammatory environment post-MI induced the upregulation of GLIPR1, which in turn promoted increased TIMP3 expression. These findings provide valuable insights for future research aimed at exploring the therapeutic potential of targeting GLIPR1 to reduce cardiac fibrosis post-MI.

Cardiac macrophages (CMs) are the most abundant immune cell type in the heart. They are critical for maintaining cardiac homeostasis and in the orchestration of immune responses to ischemic and non-ischemic cardiomyopathies. Their functions are highly heterogeneous and regulated by their tissue microenvironment. CMs have high plasticity, which allows them to perform various functions in the myocardium to bring about homeostasis within the cardiovascular system (CVS). CMs also play critical roles in coronary development and angiogenesis, tissue repair and remodeling, cardiac conduction and in the clearance of necrotic and apoptotic cells. However, there is a paucity of studies on the biology of cardiac macrophages in both steady state and disease, especially, in humans. In this review, we discuss the multifaceted roles of CMs in the heart, focusing on their ontogeny, homeostatic functions and immunological responses during inflammation and reparative processes post-injury. We highlight the heterogeneity of CMs in their ontogeny, phenotypes and functions as well as their roles in the pathogenesis of pathological conditions such as myocarditis, myocardial fibrosis and heart failure. Understanding the unique characteristics of cardiac macrophages in the cardiac milieu is critical for the development of macrophage-specific therapeutic interventions to alleviate the global burden of cardiovascular disease (CVD). Therefore, future studies should focus on further improving the understanding of the biology of cardiac macrophages to harness their potential as therapeutic targets for cardiovascular disorders.

Doxorubicin-induced cardiotoxicity (DIC) poses a significant challenge in cancer treatment. This study investigated the role of SLAMF7 in DIC, particularly in macrophage-mediated inflammation. Using SLAMF7 knockout mice, we found that SLAMF7 deficiency exacerbates DIC and amplifies inflammatory responses. Mechanistically, SLAMF7 interacts with TNF receptor-associated factor 6 to attenuate nuclear factor κB signaling, reducing oxidative stress and proinflammatory cytokines. Notably, administering recombinant SLAMF7 protein effectively mitigated DIC. These findings underscore the critical role of SLAMF7 in protecting against DIC, positioning it as a promising therapeutic target.

Single-cell RNA sequencing (scRNA-seq) is a rapidly developing and useful technique for elucidating biological mechanisms and characterizing individual cells. Tens of millions of patients worldwide suffer from heart injuries and other types of heart disease. Neonatal mammalian hearts and certain adult vertebrate species, such as zebrafish, can fully regenerate after myocardial injury. However, the adult mammalian heart is unable to regenerate the damaged myocardium. scRNA-seq provides many new insights into pathological and normal hearts and facilitates our understanding of cellular responses to cardiac injury and repair at different stages, which may provide critical clues for effective therapies for adult heart regeneration. In this review, we summarize the application of scRNA-seq in heart development and regeneration and describe how important molecular mechanisms can be harnessed to promote heart regeneration.

Both exercise and cancer can cause adipose tissue shrinkage. However, only cancer-associated weight loss, namely cachexia, is characterized by profound adipose inflammation and fibrosis. Here, we identified tumor-secreted macrophage migration inhibitory factor (MIF) as a major driver that skews the differentiation of adipose stem and progenitor cells (ASPCs) toward a pro-inflammatory and pro-fibrogenic direction, with reduced adipogenic capacity in cancer cachexia. By contrast, circulating MIF is moderately reduced after exercise. Mechanistically, atypical chemokine receptor 3 (ACKR3) in ASPCs serves as the predominant MIF receptor mediating its pathological effects. Inhibition of MIF by gene ablation in tumor cells or pharmacological blockade, as well as ASPC-specific Ackr3 deficiency, markedly alleviates tumor-induced cachexia. These findings unveil MIF-ACKR3 signaling as a critical link between tumors and cachectic manifestations, providing a promising therapeutic target for cancer cachexia.

Post-injury remodeling is a complex process involving temporal specific cellular interactions in the injured tissue where the resident fibroblasts play multiple roles. Here, we performed single-cell and spatial transcriptome analysis in human and mouse infarcted hearts to dissect the molecular basis of these interactions. We identified a unique fibroblast subset with high CD248 expression, strongly associated with extracellular matrix remodeling. Genetic Cd248 deletion in fibroblasts mitigated cardiac fibrosis and dysfunction following ischemia/reperfusion. Mechanistically, CD248 stabilizes type I transforming growth factor beta receptor and thus upregulates fibroblast ACKR3 expression, leading to enhanced T cell retention. This CD248-mediated fibroblast-T cell interaction is required to sustain fibroblast activation and scar expansion. Disrupting this interaction using monoclonal antibody or chimeric antigen receptor T cell reduces T cell infiltration and consequently ameliorates cardiac fibrosis and dysfunction. Our findings reveal a CD248+ fibroblast subpopulation as a key regulator of immune-fibroblast cross-talk and a potential therapy to treat tissue fibrosis.

Excessive cardiac fibrosis is a key cause of heart failure and adverse ventricular remodeling after myocardial infarction. The abnormally activated fibroblasts after scar maturation are the chief culprit. Single-cell RNA sequencing of mouse cardiac interstitial cells after myocardial infarction depicts a late-activated fibroblast subpopulation F-Act and initially identifies its characteristic antigen CD248, which is also verified in human hearts. On this basis, we develop a CD248-targeted biotin-binding immune receptor T cell therapy against F-Act to correct cardiac repair disorders. In our study, the precise removal of F-Act after the scar matured effectively inhibits fibrotic expansion in the peri-infarct zone and improves cardiac function. This therapy provides an idea for the treatment of cardiac fibrosis and also promotes the application of engineered T cells to non-tumor diseases.

This study investigated Hippo signaling pathway-related biomarkers in acute myocardial infarction (AMI). First, differentially expressed genes (DEGs) between AMI patients and controls were identified. Consensus clustering then classified AMI subtypes, followed by subtype-specific DEG screening. Candidate genes were derived from intersecting initial DEGs with subtype-associated DEGs. Three machine-learning algorithms prioritized five biomarkers (NAMPT, CXCL1, CREM, GIMAP6, and GIMAP7), validated through multi-dataset analyses and cellular expression profiling. qRT-PCR and Western blot confirmed differential expression patterns between AMI and controls across experimental models. Notably, NAMPT, CXCL1, and GIMAP6 exhibited cell-type-specific expression in endothelial cells and macrophages. We further predicted 179 potential therapeutic agents targeting these biomarkers. Niclosamide and eugenol were observed to mitigate hypoxia-induced injury in neonatal mouse ventricular cardiomyocytes. In vivo experiments demonstrated upregulated NAMPT/CXCL1 and downregulated GIMAP6/GIMAP7 in AMI myocardial tissues, with significant NAMPT protein elevation. These biomarkers show clinical diagnostic potential and provide mechanistic insights into AMI pathogenesis.

Cardiac amyloidosis is a secondary phenomenon of an already pre-existing chronic condition. Whether cardiac amyloidosis represents one of the complications post myocardial infarction (MI) has yet to be fully understood. Here, we show that amyloidosis occurs after MI and that amyloid fibers are composed of macrophage-derived serum amyloid A 3 (SAA3) monomers. SAA3 overproduction in macrophages is triggered by exosomal communication from cardiac stromal cells (CSCs), which, in response to MI, activate the expression of a platelet aggregation-inducing type I transmembrane glycoprotein, Podoplanin (PDPN). CSCPDPN+-derived small extracellular vesicles (sEVs) are enriched in SAA3, and exosomal SAA3 engages with macrophage by Toll-like receptor 2, triggering overproduction with consequent impaired clearance and aggregation of SAA3 monomers into rigid fibers. SAA3 amyloid deposits reduce cardiac contractility and increase scar stiffness. Inhibition of SAA3 aggregation by retro-inverso D-peptide, specifically designed to bind SAA3 monomers, prevents the deposition of SAA3 amyloid fibrils and improves heart function post MI.

Single-cell omics technologies have transformed our investigation of genomic, transcriptomic, and proteomic landscapes at the individual cell level. In particular, the application of single-cell RNA sequencing has unveiled the complex transcriptional variations inherent in cardiac cells, offering valuable perspectives into their dynamics. This review focuses on the integration of single-cell omics with induced pluripotent stem cells (iPSCs) in the context of cardiovascular research, offering a unique avenue to deepen our understanding of cardiac biology. By synthesizing insights from various single-cell technologies, we aim to elucidate the molecular intricacies of heart health and diseases. Beyond current methodologies, we explore the potential of emerging paradigms such as single-cell/spatial omics, delving into their capacity to reveal the spatial organization of cellular components within cardiac tissues. Furthermore, we anticipate their transformative role in shaping the future of cardiovascular research. This review aims to contribute to the advancement of knowledge in the field, offering a comprehensive perspective on the synergistic potential of transcriptomic analyses, iPSC applications, and the evolving frontier of spatial omics.

Many researchers nowadays choose multi-omics techniques for myocardial infarction studies. However, there's yet to be a review article integrating myocardial infarction multi-omics. Hence, this study adopts the popular bibliometrics. Based on its principles, we use software like R Studio, Vosviewer, Citespace, and SciMAT to analyze literature data of myocardial infarction omics research (1991-2022) from Web of Science. By extracting key information and calculating weights, we conduct analyses from 4 aspects: Collaboration Network Analysis, Co-word Analysis, Citing and Cited Journal Analysis, and Co-citation and Clustering Analysis, aiming to understand the field's cooperation, research topic evolution, and knowledge flow. The results show that myocardial infarction omics research is still in its early stage with limited international cooperation. In terms of knowledge flow, there's no significant difference within the discipline, but non-biomedical disciplines have joined, indicating an interdisciplinary integration trend. In the overall research field, genomics remains the main topic with many breakthroughs identifying susceptibility sites. Meanwhile, other omics fields like lipidomics and proteomics are also progressing, clarifying the pathogenesis. The cooperation details in this article enable researchers to connect with others, facilitating their research. The evolution trend of subject terms helps them set goals and directions, quickly grasp the development context, and read relevant literature. Journal analysis offers submission suggestions, and the analysis of research base and frontier provides references for the research's future development.

Heart failure with preserved ejection fraction (HFpEF) is a major health concern. Pathological stimuli and interactions between cardiac fibroblasts (CFs) and other cell types may lead to cardiac fibrosis and diastolic dysfunction, which are hallmarks of HFpEF. Interstitial and perivascular cardiac fibrosis correlates with poor prognosis in HFpEF; however, mechanisms of fibrosis remain poorly elucidated, and targeted therapies are lacking. Cardiac reprogramming is a promising therapeutic approach for myocardial infarction that facilitates cardiac regeneration and antifibrosis action through Mef2c/Gata4/Tbx5/Hand2 (MGTH) overexpression in resident CFs. However, the efficacy of this approach on HFpEF is yet to be established.

Herein, we examined the effects of cardiac reprogramming in HFpEF using Tcf21iCre/Tomato/MGTH2A transgenic mice, which expressed both MGTH and reporter expression in CFs for cardiac reprogramming and lineage tracing upon tamoxifen administration. To establish HFpEF model mice, we used a combination of a high-fat diet and nitric oxide synthase inhibition. Bulk RNA-sequencing, single-cell RNA-sequencing, and spatial transcriptomics were conducted to determine fibrotic mechanisms and the efficacy of cardiac reprogramming in HFpEF. We generated new tamoxifen-inducible transgenic mice overexpressing each reprogramming factor in CFs to investigate the effect of single factors. Last, we analyzed the effect of reprogramming factors in human CFs.

Cardiac reprogramming with MGTH overexpression improved diastolic dysfunction, cardiac hypertrophy, fibrosis, inflammation, and capillary loss in HFpEF. Cardiac reprogramming converted approximately 1% of resident CFs into induced cardiomyocytes. Bulk RNA-seq indicated that MGTH overexpression upregulated genes related to heart contraction and suppressed the fetal gene program (Nppa and Nppb) and proinflammatory and fibrotic signatures. Single-cell RNA-sequencing and spatial transcriptomics revealed that multiple CF clusters upregulated fibrotic genes to induce diffuse interstitial fibrosis, whereas distinct CF clusters generated focal perivascular fibrosis in HFpEF. MGTH overexpression reversed these profibrotic changes. Among 4 reprogramming factors, only Gata4 overexpression in CFs reduced fibrosis and improved diastolic dysfunction in HFpEF by suppressing CF activation without generating new induced cardiomyocytes. Gata4 overexpression also suppressed profibrotic signatures in human CFs.

Overexpressing Gata4 in CFs may be a promising therapeutic approach for HFpEF by suppressing fibrosis and improving diastolic dysfunction.

Cardiovascular fibrosis is a common pathological process that contributes to the development and progression of various cardiovascular diseases. Despite being widely believed to be an irreversible and relentless process, preclinical models and clinical trials have shown that cardiovascular fibrosis is an extremely dynamic process. Additionally, as part of the innate immune system, macrophages are heterogeneous cells that are pivotal in tissue regeneration and fibrosis. They participate in fibroblast activation, extracellular matrix remodelling, and the regression of fibrosis. Although we have made some advances in understanding macrophages in cardiovascular fibrosis, a gap still remains between their identification and conversion into effective treatments. Moreover, the traditional M1-M2 paradigm faces many challenges because it does not sufficiently clarify macrophage diversity and their functions. Exploring novel macrophage-based therapies is urgent for cardiovascular fibrosis treatment. Single-cell techniques have shed light on identifying novel subpopulations that differ in function and molecular signature under steady-state and pathological conditions. In this review, we outline the developmental origins of macrophages, which underlie their functions; and recent technology development in the single-cell era. In addition, we describe the markers and mediators of the newly defined macrophage subpopulations and the molecular mechanisms involved to elucidate potential approaches for targeting macrophages in cardiovascular fibrosis.

Dilated cardiomyopathy (DCM) is characterized by immune cell infiltration and can readily progress to heart failure (HF). In the study, differential expression analysis, enrichment analysis, and protein-protein interaction (PPI) network analysis were performed on DCM with HF-related datasets. The CytoHubba was used to identify hub genes. Diagnostic biomarkers were obtained by validating their expression and diagnostic value in another external dataset, and a diagnostic model was constructed. Finally, single-sample gene set enrichment analysis (ssGSEA) was used to predict immune cell infiltration in cardiac samples. The associations between diagnostic biomarkers and immune cells were investigated. The NetworkAnalyst and miRDB databases were used to predict transcription factors and microRNAs, followed by establishing regulatory networks. The DSigDB database was used to predict drug candidates. Subsequently, a mouse model of DCM with HF was used to validate the expression levels of these genes. The present study revealed that differentially expressed genes were enriched in the extracellular matrix organization, cardiac muscle hypertrophy, and other immune-related biological processes. OMD and THBS4 were finally identified, and the nomogram has satisfactory prediction and strong calibration ability. In addition, the two diagnostic biomarkers exhibited significant associations with multiple immune infiltrating cells. Finally, two TFs, 65 microRNAs, and 10 drug candidates were obtained. In animal experiments, two diagnostic biomarkers showed expression trends consistent with the results of bioinformatic analysis. OMD and THBS4 have been identified as hub immune-related diagnostic biomarkers for DCM with HF. Our research provides novel insights into the diagnosis and treatment of the disease.

Type A aortic dissection (TAAD) is a life-threatening condition characterized by complex pathophysiology, in which macrophages play a critical but not yet fully understood role. This study focused on the role of endothelial cells with elevated expression of ACKR1 (atypical chemokine receptor 1) and their interaction with proinflammatory macrophages in TAAD development.

Single-cell transcriptomic analysis of human aortic tissues was used to identify cellular heterogeneity in TAAD. Clinical and animal studies evaluated the relationship between ACKR1 expression and TAAD severity. Gain- and loss-of-function experiments, involving modulation of ACKR1 expression in ECs, investigated its role in macrophage regulation. Molecular docking and in vitro/in vivo studies identified and tested potential drugs targeting ACKR1.

TAAD tissues exhibited increased ECs with high ACKR1 expression and proinflammatory macrophages. High ACKR1 levels were strongly associated with TAAD severity. Knockdown of ACKR1 suppressed the NF-κB (nuclear factor-κB) signaling pathway and SPP1 (secreted phosphoprotein 1) expression, reducing macrophage migration and polarization, thereby inhibiting TAAD progression. Conversely, overexpression of ACKR1 exacerbated TAAD. Amikacin, identified as an ACKR1 targeted drug, regulated macrophage behavior via the ACKR1/NF-κB/SPP1 pathway, attenuating TAAD progression and improving survival in mice.

This study reveals how endothelial cells exhibiting high ACKR1 expression modulate macrophage migration and proinflammatory polarization through the ACKR1/NF-κB/SPP1 signaling pathway, a crucial mechanism in TAAD progression. Targeting ACKR1 through both functional and pharmacological approaches effectively suppressed TAAD progression and extended survival in TAAD mice, offering promising new intervention strategies for clinical evaluation.

Single-cell technology (SCT), which enables the examination of the fundamental units comprising biological organs, tissues, and cells, has emerged as a powerful tool, particularly in the field of biology, with a profound impact on stem cell research. This innovative technology opens new pathways for acquiring cell-specific data and gaining insights into the molecular pathways governing organ function and biology. SCT is not only frequently used to explore rare and diverse cell types, including stem cells, but it also unveils the intricacies of cellular diversity and dynamics. This perspective, crucial for advancing stem cell research, facilitates non-invasive analyses of molecular dynamics and cellular functions over time. Despite numerous investigations into potential stem cell therapies for genetic disorders, degenerative conditions, and severe injuries, the number of approved stem cell-based treatments remains limited. This limitation is attributed to the various heterogeneities present among stem cell sources, hindering their widespread clinical utilization. Furthermore, stem cell research is intimately connected with cutting-edge technologies, such as microfluidic organoids, CRISPR technology, and cell/tissue engineering. Each strategy developed to overcome the constraints of stem cell research has the potential to significantly impact advanced stem cell therapies. Drawing on the advantages and progress achieved through SCT-based approaches, this study aims to provide an overview of the advancements and concepts associated with the utilization of SCT in stem cell research and its related fields.

Mechanical stress and pathological signaling trigger the activation of fibroblasts to myofibroblasts, which impacts extracellular matrix composition, disrupts normal wound healing, and can generate deleterious fibrosis. Myocardial fibrosis independently promotes cardiac arrhythmias, sudden cardiac arrest, and contributes to the severity of heart failure. Fibrosis can also alter cell-to-cell communication and increase myocardial stiffness which eventually may lead to lusitropic and inotropic cardiac dysfunction. Human induced pluripotent stem cell derived cardiac fibroblasts (hiPSC-CFs) have the potential to enhance clinical relevance in precision disease modeling by facilitating the study of patient-specific phenotypes. However, it is unclear whether hiPSC-CFs can be activated to become myofibroblasts akin to primary cells, and the key signaling mechanisms in this process remain unidentified.

We aim to explore the notable changes in fibroblast phenotype upon passage-mediated activation of hiPSC-CFs with increased mitochondrial metabolism, like primary cardiac fibroblasts.

We activated the hiPSC-CFs with serial passaging from passage 0 to 3 (P0 to P3) and treatment of P0 with TGFβ1.

Passage-mediated activation of hiPSC-CFs was associated with a gradual induction of genes to initiate the activation of these cells to myofibroblasts, including collagen, periostin, fibronectin, and collagen fiber processing enzymes with concomitant downregulation of cellular proliferation markers. Most importantly, canonical TGFβ1 and Hippo signaling component genes including TAZ were influenced by passaging hiPSC-CFs. Seahorse assay revealed that passaging and TGFβ1 treatment increased mitochondrial respiration, consistent with fibroblast activation requiring increased energy production, whereas treatment with the glutaminolysis inhibitor BPTES completely attenuated this process.

Our study highlights that the hiPSC-CF passaging enhanced fibroblast activation, activated fibrotic signaling pathways, and enhanced mitochondrial metabolism approximating what has been reported in primary cardiac fibroblasts. Thus, hiPSC-CFs may provide an accurate in vitro preclinical model for the cardiac fibrotic condition, which may facilitate the identification of putative anti-fibrotic therapies, including patient-specific approaches.

The immune system plays a crucial role in the development of kidney diseases. Chronic kidney disease (CKD) can lead to various complications, potentially affecting multiple systems throughout the body. Currently, the description of the immune system in human CKD is not comprehensive enough. Constructing a CKD kidney atlas using single-cell RNA sequencing (scRNA-seq) can provide deeper insights into the composition and functional changes of immune cells in CKD, facilitating the discovery of new therapeutic targets.

We processed and integrated scRNA-seq datasets from healthy and CKD kidneys from three independent cohorts using the same approach (including 42 normal samples and 23 chronic kidney disease samples). Subsequently, we conducted gene enrichment and intercellular communication analysis to construct an immune cell atlas of the kidneys in CKD patients.

We identified nine major kidney cell clusters. Further clustering analysis of different immune cell clusters revealed that, compared to normal kidneys, CKD patients' kidneys had decreased CD16+ NK cells while CD4+ naive helper T cells and CCR7+ DC increased. Partial activation of the WNT signaling pathway was observed in T cells and NK cells of CKD patients, while some metabolism-related genes were inhibited. Myeloid cell subgroups also exhibited abnormal signaling pathway alterations. Additionally, we discovered a unique population of SPP1 macrophages in CKD, which are recruited by chemokines released from aPT and aTAL cell subpopulations. These SPP1 macrophages may promote cellular fibrosis through the signaling of SPP1, FN1, and various receptors.

We established a human CKD kidney immune cell atlas and identified SPP1 macrophages as a unique cell type in CKD. The interaction between SPP1 macrophages and damaged cells may serve as a potential therapeutic target for treating CKD in the future.

Fibrosis is defined by the excessive accumulation of extracellular matrix (ECM) and constitutes a central pathophysiological process that underlies tissue dysfunction, across organs, in multiple chronic diseases and during aging. Myocardial fibrosis is a key contributor to dysfunction and failure in numerous diseases of the heart and is a strong predictor of poor clinical outcome and mortality. The excess structural and matricellular ECM proteins deposited by cardiac fibroblasts, is found between cardiomyocytes (interstitial fibrosis), in focal areas where cardiomyocytes have died (replacement fibrosis), and around vessels (perivascular fibrosis). Although myocardial fibrosis has important clinical prognostic value, access to cardiac tissue biopsies for histological evaluation is limited. Despite challenges with sensitivity and specificity, cardiac magnetic resonance imaging (CMR) is the most applicable diagnostic tool in the clinic, and the scientific community is currently actively searching for blood biomarkers reflecting myocardial fibrosis, to complement the imaging techniques. The lack of mechanistic insights into specific pro- and anti-fibrotic molecular pathways has hampered the development of effective treatments to prevent or reverse myocardial fibrosis. Development and implementation of anti-fibrotic therapies is expected to improve patient outcomes and is an urgent medical need. Here, we discuss the importance of the ECM in the heart, the central role of fibrosis in heart disease, and mechanistic pathways likely to impact clinical practice with regards to diagnostics of myocardial fibrosis, risk stratification of patients, and anti-fibrotic therapy.

Inflammation, fibrosis and metabolic stress critically promote heart failure with preserved ejection fraction (HFpEF). Exposure to high-fat diet and nitric oxide synthase inhibitor N[w]-nitro-l-arginine methyl ester (L-NAME) recapitulate features of HFpEF in mice. To identify disease-specific traits during adverse remodeling, we profiled interstitial cells in early murine HFpEF using single-cell RNAseq (scRNAseq). Diastolic dysfunction and perivascular fibrosis were accompanied by an activation of cardiac fibroblast and macrophage subsets. Integration of fibroblasts from HFpEF with two murine models for heart failure with reduced ejection fraction (HFrEF) identified a catalog of conserved fibroblast phenotypes across mouse models. Moreover, HFpEF-specific characteristics included induced metabolic, hypoxic and inflammatory transcription factors and pathways, including enhanced expression of Angiopoietin-like 4 (Angptl4) next to basement membrane compounds, such as collagen IV (Col4a1). Fibroblast activation was further dissected into transcriptional and compositional shifts and thereby highly responsive cell states for each HF model were identified. In contrast to HFrEF, where myofibroblast and matrifibrocyte activation were crucial features, we found that these cell states played a subsidiary role in early HFpEF. These disease-specific fibroblast signatures were corroborated in human myocardial bulk transcriptomes. Furthermore, we identified a potential cross-talk between macrophages and fibroblasts via SPP1 and TNFɑ with estimated fibroblast target genes including Col4a1 and Angptl4. Treatment with recombinant ANGPTL4 ameliorated the murine HFpEF phenotype and diastolic dysfunction by reducing collagen IV deposition from fibroblasts in vivo and in vitro. In line, ANGPTL4, was elevated in plasma samples of HFpEF patients and particularly high levels associated with a preserved global-longitudinal strain. Taken together, our study provides a comprehensive characterization of molecular fibroblast activation patterns in murine HFpEF, as well as the identification of Angiopoietin-like 4 as central mechanistic regulator with protective effects.

The co-occurrence of heart failure (HF) and cancer represents a complex and multifaceted medical challenge. Patients with prevalent cardiovascular disease (CVD), particularly HF, exhibit an increased risk of cancer development, raising questions about the intricate interplay between these two prevalent conditions. This review aims to explore the evolving landscape of cancer development in patients with HF, shedding light on potential mechanisms, risk factors, and clinical implications.

Epidemiological data suggests higher cancer incidences and higher cancer mortality in HF patients, which are potentially more common in patients with HF with preserved ejection fraction due to related comorbidities. Moreover, recent preclinical data identified novel pathways and mediators including the protein SerpinA3 as potential drivers of cancer progression in HF patients, suggesting HF as an individual risk factor for cancer development. The review emphasizes preliminary evidence supporting cancer development in patients with HF, which offers several important clinical interventions such as cancer screening in HF patients, prevention addressing both HF and cancer, and molecular targets to treat cancer. However, there is need for more detailed understanding of molecular and cellular cross-talk between cancer and HF which can be derived from prospective assessments of cancer-related outcomes in CV trials and preclinical research of molecular mechanisms.

Increasing scRNA-seq data in cardiovascular research have substantially improved our knowledge on the development of the cardiovascular system and the mechanisms underlying cardiovascular diseases. However, the single-cell transcriptome datasets were dispersed in literature and no resource for cardiovascular systems and diseases. Here, we constructed an organized resource CardioAtlas, which provides comprehensive analysis results for > 1,929,000 cells in 27 human data sets and > 1,088,000 cells in 39 mouse data sets. Through large-scale literature retrieval and manual annotation, we constructed 12 and 15 scRNA-seq reference atlas for common human and mouse cardiovascular systems and diseases, covering 43 and 39 cell types. In particular, CardioAtlas provides five analytic modules, including cell-type prediction, identification of marker genes, functional enrichment analysis, identification of cell-type-specific transcription regulons, and cell-cell communication analysis. In addition, users can upload scRNA-seq data for personalized analysis. CardioAtlas is available at http://bio-bigdata.hrbmu.edu.cn/CardioAtlas . CardioAtlas provides the first comprehensive and well-crafted reference atlas of cardiovascular systems and diseases and describes in detail previously unrecognized cell populations across a large number of humans and mice.

The sinoatrial node regulates the heart rate throughout life. Failure of this primary pacemaker results in life-threatening, slow heart rhythm. Despite its critical function, the cellular and molecular composition of the human sinoatrial node is not resolved. Particularly, no cell surface marker to identify and isolate sinoatrial node pacemaker cells has been reported. Here we use single-nuclei/cell RNA sequencing of fetal and human pluripotent stem cell-derived sinoatrial node cells to reveal that they consist of three subtypes of pacemaker cells: Core Pacemaker, Sinus Venosus, and Transitional Cells. Our study identifies a host of sinoatrial node pacemaker markers including MYH11, BMP4, and the cell surface antigen CD34. We demonstrate that sorting for CD34+ cells from stem cell differentiation cultures enriches for sinoatrial node cells exhibiting a functional pacemaker phenotype. This sinoatrial node pacemaker cell surface marker is highly valuable for stem cell-based disease modeling, drug discovery, cell replacement therapies, and the targeted delivery of therapeutics to sinoatrial node cells in vivo using antibody-drug conjugates.

Epithelial and immune cells have long been appreciated for their contribution to the early immune response after injury; however, much less is known about the role of mesenchymal cells. Using single-nuclei RNA sequencing, we defined changes in gene expression associated with inflammation 1 day after wounding in mouse skin. Compared with those in keratinocytes and myeloid cells, we detected enriched expression of proinflammatory genes in fibroblasts associated with deeper layers of the skin. In particular, SCA1+ fibroblasts were enriched for numerous chemokines, including CCL2, CCL7, and IL-33, compared with SCA1- fibroblasts. Genetic deletion of Ccl2 in fibroblasts resulted in fewer wound-bed macrophages and monocytes during injury-induced inflammation, with reduced revascularization and re-epithelialization during the proliferation phase of healing. These findings highlight the important contribution of fibroblast-derived factors to injury-induced inflammation and the impact of immune cell dysregulation on subsequent tissue repair.

Macrophages are pleiotropic and diverse cells that populate all tissues of the body. Besides tissue-specific resident macrophages such as alveolar macrophages, Kupffer cells, and microglia, multiple organs harbor at least two subtypes of other resident macrophages at steady state. During certain circumstances, like tissue insult, additional subtypes of macrophages are recruited to the tissue from the monocyte pool. Previously, a recruited macrophage population marked by expression of Spp1, Cd9, Gpnmb, Fabp5, and Trem2, has been described in several models of organ injury and cancer, and has been linked to fibrosis in mice and humans. Here, we show that Notch2 blockade, given systemically or locally, leads to an increase in this putative pro-fibrotic macrophage in the lung and that this macrophage state can only be adopted by monocytically derived cells and not resident alveolar macrophages. Using a bleomycin and COVID-19 model of lung injury and fibrosis, we find that the expansion of these macrophages before lung injury does not promote fibrosis but rather appears to ameliorate it. This suggests that these damage-associated macrophages are not, by themselves, drivers of fibrosis in the lung.