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Ischemic heart disease is a leading cause of death in the world. Formation of new blood vessels is fundamental to cardiac reperfusion and repair after myocardial infarction (MI), and therapeutic promotion of angiogenesis, therefore, has emerged as a promising strategy for treating ischemic heart diseases. However, the therapeutic efficacy is small and transient in most of pro-angiogenic therapy. Here, we characterize unexpectedly prominent vessel aberrancy, albeit a robust angiogenesis, in MI-associated cardiac tissue by 3-dementional light sheet fluorescence imaging. Our single-cell transcriptome analysis of mouse MI tissues with Cdh5-Cre ; Rosa-LSL-tdTomato -mediated endothelial lineage tracing identifies a robust EC plasticity to acquire mesenchymal gene signature in MI-associated ECs, peaked at 1 week and partially retained at 4 and 8 weeks after MI. Moreover, cardiac ECs undergo transcriptional activation to drive mesenchymal phenotypes including over-proliferation, migration and increased permeability, which lead to vessel abnormality after exposure to in vitro ischemic microenvironment. Furthermore, our single-cell and bulk RNA-seq analysis uncovers a PDGF/NF-κB/HIF-1α axis that induces Snail expression and mesenchymal phenotypes in ECs under hypoxia, culminating in aberrant vascularization. Notably, EC-specific knockout of PDGFR-β abrogates mesenchymal gene expression in ECs, attenuates vascular abnormalities in the infarcted tissue, and improves cardiac repair after MI. Interestingly, our single-nuclei analysis uncovers that genetic ablation of PDGFR-β in ECs temporally reprograms cardiomyocyte metabolism and enhances myocyte survival and proliferation. Pharmacological PDGFR inhibition or nanoparticle-based targeted PDGFR-β siRNA delivery normalizes vasculature and improves cardiac function recovery after MI. These findings illustrate a mechanism controlling aberrant neovascularization after ischemia, and suggest that targeting PDGF/Snail-mediated endothelial plasticity may offer exciting opportunities for normalizing vasculature and treating ischemic heart disease.

Myocardial infarction (MI) is a leading cause of death worldwide, largely because efficient interventions to restore cardiac function after MI are currently lacking. Here, we characterize vascular aberrancies induced by MI, and propose to target acquired endothelial cell (EC) changes to normalize vessels and promote cardiac repair after MI. Single-cell transcriptome analyses of MI-associated ECs indicates that ECs acquire mesenchymal gene signature that result in phenotypic and functional changes and lead to vessel abnormalities. We identify a PDGF/NF-κB/HIF-1α axis that induces Snail expression and mesenchymal phenotypes in ECs under hypoxia, altogether causing aberrant vascularization. EC-specific knockout of PDGFR-β, pharmacological PDGFR inhibition or nanoparticle-based targeted PDGFR-β siRNA delivery in mice attenuates vascular abnormalities in the infarcted tissue and improves cardiac repair after MI. These findings illustrate a mechanism controlling aberrant neovascularization after ischemia, and suggest that targeting PDGF/Snail-mediated endothelial plasticity may offer opportunities for normalizing vasculature and treating ischemic heart diseases.

Defective or insufficient bone repair and regeneration are common in patients as a result of major trauma or severe disease. Cell therapy with periosteal mesenchymal progenitors, which can be limited in severe injury, serves as a promising approach; however, its efficacy is limited due to a repair-hostile ischemic tissue microenvironment after traumatic fracture. Here we report that plasminogen (Plg), a factor that is upregulated in these environments, is critical for fracture healing. Plg knockout mice had impaired trabecular and cortical bone structure and exhibited delayed and incomplete fracture healing. Interestingly, Plg deficiency greatly reduced the thickness of expanded periosteum, suggesting a role of Plg in periosteal mesenchymal progenitor-mediated bone repair. In culture, Plg increased cell proliferation and migration in periosteal mesenchymal progenitors and inhibited cell death under ischemic conditions. Mechanistically, we revealed that Plg cleaved and activated Cyr61 to regulate periosteal progenitor function. Thus, our study uncovers a cellular mechanism underlying fracture healing, by which Plg activates Cyr61 to promote periosteal progenitor proliferation, survival, and migration and improves bone repair after fracture. Targeting Plg may offer a rational and effective therapeutic opportunity for improving fracture healing. © 2021 American Society for Bone and Mineral Research (ASBMR).

Stem cell transplantation has emerged as a promising strategy in regenerative medicine. However, the poor survival and persistence of the transplanted cells, including mesenchymal stem cells (MSCs), in the hostile ischemic microenvironments represents a major therapeutic barrier. Here we report that plasminogen (Plg) stimulated MSC functions and promoted MSC survival during tissue repair after ischemia. Genetic Plg ablation abolished MSC survival, migration, and proliferation in mouse ischemic limbs, and abrogated MSC-mediated blood reperfusion, neovascularization, and tissue repair after ischemia, suggesting a critical role for Plg in MSC-mediated tissue repair. Furthermore, multiplex cytokine array analysis identified that Plg cleaved and activated cysteine-rich protein 61 (Cyr61), an ECM-associated growth factor, to stimulate MSC survival and migration. Overexpression with truncated Cyr61 in MSCs rescued blood reperfusion after hind limb ischemia in Plg-deficient mice. Finally, Plg-mediated Cyr61 cleavage promoted endothelial cell migration and neovascularization in vitro and in vivo. Our study reveals that Plg promotes MSC survival, persistence, and paracrine effects and improves postischemic neovascularization and tissue repair through Cyr61 cleavage and activation. Thus, targeting Plg/Cyr61 may offer exciting therapeutic opportunities for strengthening MSC therapy in ischemic diseases., Plasminogen promotes mesenchymal stem cell function and improves post-ischemic neovascularization and tissue repair through cysteine-rich protein 61 activation.

Background Coronary atherosclerotic heart disease (CHD) is the most common cardiovascular disease and has become a leading cause of death globally. Various molecular typing methods are available for the diagnosis and treatment of tumors. However, molecular typing results are not routinely used for CHD. Methods and Results Aiming to uncover the underlying molecular features of different types of CHD, we screened the differentially expressed genes (DEGs) associated with CHD based on the Gene Expression Omnibus (GEO) data and expanded those with the NCBI‐gene and OMIM databases to finally obtain 2021 DEGs. The weighted gene co‐expression analysis (WGCNA) was performed on the candidate genes, and six distinctive WGCNA modules were identified, two of which were associated with CHD. Moreover, DEGs were mined as key genes for co‐expression based on the module network relationship. Furthermore, the differentially expressed miRNAs in CHD and interactions in the database were mined in the GEO data set to build a multifactor regulatory network of key genes for co‐expression. Based on the network, the CHD samples were further classified into five clusters and we defined FTH1, HCAR3, RGS2, S100A9, and TYROBP as the top genes of the five subgroups. Finally, the mRNA levels of FTH1, S100A9, and TYROBP were found to be significantly increased, while the expression of HCAR3 was decreased in the blood of CHD patients. We did not detect measurable levels of RGS2. Conclusion The screened core clusters of genes may be a target for the diagnosis and treatment of CHD as a molecular typing module., WGCNA was performed on CHD‐related datasets downloaded from online datebases to screened out DEGs and a multi‐factor regulatory network of key genes for co‐expression. Based on the aforementioned network, the CHD samples were further classified into 5 clusters and we defined FTH1, HCAR3, RGS2, S100A9 and TYROBP as individually top genes of 5 subgroups.

Background: Cyclophilin A (CyPA) plays an important role in the progression of atherosclerosis. Additionally, it has been reported that lysosomal function is markedly impaired in atherosclerosis induced by oxidized low-density lipoprotein (ox-LDL). As the CyPA degradation pathway remains to be elucidated, we aimed to uncover the role of lysosomes and ox-LDL in the degradation of CyPA. Methods: We exploited RNA interference (RNAi) in combination with either the lysosomal inhibitor chloroquine (CQ) or the proteasomal inhibitor MG-132 to examine CyPA turnover. We also investigated the role of ox-LDL in lysosomal function and the CyPA degradation pathway and determined whether CyPA interacts with the selective autophagy adaptor p62. Results: CQ markedly reversed the CyPA downregulation induced by RNAi and increased intracellular levels of LC3 and p62. MG-132 significantly suppressed polyubiquitinated protein degradation but did not inhibit RNAi-induced CyPA downregulation. Additionally, neither CQ nor MG-132 influenced the gene-silencing efficiency of CyPA siRNA. Moreover, ox-LDL induced cytosolic accumulation of p62 was inconsistent with increased expression of LC3-II. Meanwhile, ox-LDL inhibited RNAi-induced downregulation of CyPA. Immunofluorescence indicated colocalization of endogenous CyPA with ubiquitin and with p62 in response to CQ treatment, and co-immunoprecipitation analysis confirmed interaction between CyPA and p62. Conclusion: CyPA is degraded by a lysosome-dependent pathway that may involve p62-mediated selective autophagy. Furthermore, ox-LDL modulates the degradation of CyPA via its inhibitory role in lysosomes, contributing to increased expression of CyPA in atherosclerotic plaques.

Objective: To investigate the significance of hemoglobin A1c (HbA1c) in cardiovascular and metabolic risk stratification among diabetes and non-diabetes in southern Chinese. Methods: Indigenous adults (aged more than or equal to 35 years) without known diabetes were enrolled in the cross-sectional survey. According to oral glucose tolerance test (OGTT), participants were categorized into OGTT-negative group and OGTT-positive group. Cardiovascular and metabolic risk profile was compared between different HbA1c levels (≥ 6.5% vs. < 6.5%) in each group. Results: The prevalence of OGTT-diagnosed diabetes was 6.45% (422/6540). In OGTT-negative group, subjects with HbA1c ≥ 6.5% were older, had higher prevalence of coronary heart disease, current smoking, hypertension, obesity and abdominal obesity. They also had higher body weight, waist–hip ratio, body mass index, glucose levels (fasting plasma glucose, 2-hour plasma glucose and HbA1c), and lipid levels (total cholesterol and low density lipoprotein cholesterol). In OGTT-positive group, patients with HbA1c ≥ 6.5% identified less cardiovascular and metabolic risk file than that in OGTT-negative group. Conclusions: Subjects with HbA1c ≥ 6.5% have more unfavorable cardiovascular and metabolic risk profile than those with HbA1c < 6.5%, especially in OGTT-negative population. More attention should be paid to this subgroup in clinical practice.

Objectives Yes-associated protein (YAP) has been reported to regulate cell proliferation and differentiation. We aimed to characterize the role of YAP in angiotensin II (Ang II)-induced hypertensive vascular remodelling (HVR) and vascular smooth muscle cells (VSMCs) phenotypic modulation and to explore the underlying mechanisms. Materials and methods An HVR rat model was established by continuous Ang II infusion for 2 weeks. Western blotting, qRT-PCR, and confocal microscopy were conducted to assess YAP expression. YAP-shRNA interfering plasmid and adenovirus were constructed to knock down YAP. We used cell proliferation and migration assays, accompanied by pathway inhibitors, to evaluate the biological function and underlying mechanisms. Results Ang II upregulated YAP expression in the media of carotid artery; however, in vivo YAP silencing significantly mitigated HVR, independent of the blood pressure level. Ang II upregulated YAP expression and promoted YAP nuclear accumulation in a dose- and time-dependent manner in rat VSMCs. YAP knockdown ameliorated Ang II-induced VSMCs phenotypic modulation. The regulation of YAP by Ang II could be blocked by pretreatment with angiotensin receptor type 1 antagonist losartan or F-actin depolymerizing agent latrunculin B but not the AT2R antagonist PD 123319. Disrupting the YAP-TEA domain (TEAD) interaction with verteporfin inhibited Ang II-induced VSMCs phenotypic modulation. Conclusions Yes-associated protein mediated angiotensin II-induced VSMCs phenotypic modulation and vascular remodelling. YAP is a potential therapeutic target for HVR beyond blood pressure control.