Histone methyltransferase MLL4 protects against pressure overload-induced heart failure via a THBS4-mediated protection in ER stress.

Pressure overload-induced pathological cardiac hypertrophy eventually leads to heart failure (HF). Unfortunately, lack of effective targeted therapies for HF remains a challenge in clinical management. Mixed-lineage leukemia 4 (MLL4) is a member of the SET family of histone methyltransferase enzymes, which possesses histone H3 lysine 4 (H3K4)-specific methyltransferase activity. However, whether and how MLL4 regulates cardiac function is not reported in adult HF. Here we report that MLL4 is required for endoplasmic reticulum (ER) stress homeostasis of cardiomyocytes and protective against pressure overload-induced cardiac hypertrophy and HF. We observed that MLL4 is increased in the heart tissue of HF mouse model and HF patients. The cardiomyocyte-specific deletion of Mll4 (Mll4-cKO) in mice leads to aggravated ER stress and cardiac dysfunction following pressure overloading. MLL4 knockdown neonatal rat cardiomyocytes (NRCMs) also display accelerated decompensated ER stress and hypertrophy induced by phenylephrine (PE). The combined analysis of Cleavage Under Targets and Tagmentation sequencing (CUT&Tag-seq) and RNA sequencing (RNA-seq) data reveals that, silencing of Mll4 alters the chromatin landscape for H3K4me1 modification and gene expression patterns in NRCMs. Interestingly, the deficiency of MLL4 results in a marked reduction of H3K4me1 and H3K27ac occupations on Thrombospondin-4 (Thbs4) gene loci, as well as Thbs4 gene expression. Mechanistically, MLL4 acts as a transcriptional activator of Thbs4 through mono-methylation of H3K4 and further regulates THBS4-dependent ER stress response, ultimately plays a role in HF. Our study indicates that pharmacologically targeting MLL4 and ER stress might be a valid therapeutic approach to protect against cardiac hypertrophy and HF.

dCas9-Based PDGFR-ß Activation ADSCs Accelerate Wound Healing in Diabetic Mice through Angiogenesis and ECM Remodeling.

The chronic wound represents a serious disease characterized by a failure to heal damaged skin and surrounding soft tissue. Mesenchymal stem cells (MSCs) derived from adipose tissue (ADSCs) are a promising therapeutic strategy, but their heterogeneity may result in varying or insufficient therapeutic capabilities. In this study, we discovered that all ADSCs populations expressed platelet-derived growth factor receptor ß (PDGFR-ß), while the expression level decreased dynamically with passages. Thus, using a CRISPRa-based system, we endogenously overexpressed PDGFR-ß in ADSCs. Moreover, a series of in vivo and in vitro experiments were conducted to determine the functional changes in PDGFR-ß activation ADSCs (AC-ADSCs) and to investigate the underlying mechanisms. With the activation of PDGFR-ß, AC-ADSCs exhibited enhanced migration, survival, and paracrine capacity relative to control ADSCs (CON-ADSCs). In addition, the secretion components of AC-ADSCs contained more pro-angiogenic factors and extracellular matrix-associated molecules, which promoted the function of endothelial cells (ECs) in vitro. Additionally, in in vivo transplantation experiments, the AC-ADSCs transplantation group demonstrated improved wound healing rates, stronger collagen deposition, and angiogenesis. Consequently, our findings revealed that PDGFR-ß overexpression enhanced the migration, survival, and paracrine capacity of ADSCs and improved therapeutic effects after transplantation to diabetic mice.

[Histone methylation and diabetic cardiomyopathy].

Histone methylation is one of the key post-translational modifications that plays a critical role in various heart diseases, including diabetic cardiomyopathy. A great deal of evidence has shown that histone methylation is closely related to hyperglycemia, insulin resistance, lipid and advanced glycation end products deposition, inflammatory and oxidative stress, endoplasmic reticulum stress and cell apoptosis, and these pathological factors play an important role in the pathogenesis of diabetic cardiomyopathy. In order to provide a novel theoretical basis and potential targets for the treatment of diabetic cardiomyopathy from the perspective of epigenetics, this review discussed and elucidated the association between histone methylation and the pathogenesis of diabetic cardiomyopathy in details.

A novel protein CMTM1-v5 specifically induced human lymphoma cells apoptosis in vitro and in vivo.

Lymphoma is among the top 10 leading causes of cancer-related morbidity around the world in males, but currently, there is a lack of effective treatment strategies for this disease. Recently, we identified an alternatively spliced protein isoform, CMTM1-v5, which is significantly associated with tumor development and could serve as a potential therapeutic drug for lymphoma. Here, we showed that the overexpression of CMTM1-v5 in Raji cells or the addition of the CMTM1-v5 polypeptide to the cell culture medium induced apoptosis in vitro. During the in vivo experiments, most of the fluorescent CMTM1-v5 polypeptide converged within the tumor cells in Raji xenografts 24 h after treatment, and the injection of the polypeptide into the tail vein significantly extended survival in mice bearing Raji tumor cells. Mechanistically, the interaction between CMTM1-v5 and CAML (calcium-modulating cyclophilin ligand) negatively regulated the Ca2+ response in the ER, inducing the activation of caspases and the release of cytochrome c in mitochondria and resulting in cell apoptosis. Thus, our study provides a proof-to-concept that supports the use of CMTM1-v5 to treat lymphoma.

[Research progress of histone 3 methyltransferase MLL4].

Mixed linked leukemia 4 (MLL4) is a specific methyltransferase of histone 3 position lysine 4 (H3K4). It is also one of the important members of COMPASS/Set1-like protein complex. Both MLL4 protein itself and its mediated H3K4 methylation modification can cause changes in chromatin structure and function, thus regulating gene transcription and expression. With the studies of MLL4 protein in recent years, the roles of MLL4 gene, MLL4 protein and protein complex in the development of tissues and organs, tumor diseases and other physiological and pathophysiological processes have been gradually revealed. In this paper, the research progress of MLL4 gene, MLL4 protein characteristics, biological function and its effect on disease were reviewed, in order to further understand the effect of histone methyltransferase on gene expression regulation, as well as its non-enzyme dependent function. This paper may provide new ideas for the prevention, diagnosis and treatment of related diseases.

Identification of potential crucial gene network related to seasonal allergic rhinitis using microarray data.

The aim of this study was to reveal a potential key gene network associated with seasonal allergic rhinitis (SAR). The microarray data GSE50101 downloaded from Gene Expression Omnibus were used to screen differentially expressed genes (DEGs) between SAR patients and healthy controls. Then, functional enrichment analysis was conducted using Database for Annotation, Visualization, and Integrated Discovery. Afterwards, the protein-protein interactions (PPIs) of DEGs were obtained from STRING, and the PPI network was constructed. In addition, the PPI network module was analyzed. In total, 98 up-regulated and 63 down-regulated DEGs were identified from the SAR samples, comparing the healthy controls. The up-regulated DEGs were mainly enriched in the Gene Ontology terms about cell death (e.g., DUSP1 and JUN) and pathways related to immune (e.g., FOS and JUN). The down-regulated DEGs were mainly enriched in regulation of transcription (e.g., CEBPD and SCML1). In the PPI network, a set of genes was predicted to interact with each other, such as FOS, JUN, and CEBPD. Furthermore, genes in the network module (e.g., FOS, JUN and CEBPD) was mainly enriched in regulation of transcription, and pathways about immune, such as mitogen-activated protein kinase signaling pathway, B cell receptor signaling pathway, and toll-like receptor signaling pathway. Several genes related to immunity and regulation of transcription, such as FOS, JUN, and CEBPD, may play crucial roles during the process of SAR through the interactions with each other.

Assessment of the Anti-anginal Effect of Tetramethylpyrazine Using Vasopressin-Induced Angina Model Rats.

Intravenous tetramethylpyrazine has been widely used in China as a complementary and/or alternative medicine to treat patients with ischemic heart disease. We assessed the anti-anginal effect of tetramethylpyrazine (10 mg/kg, intravenously (i.v.), n=6) in comparison with that of its vehicle, saline (1 mL/kg, i.v., n=6), using vasopressin-induced angina model rats. First, Donryu rats were anesthetized with pentobarbital sodium (60 mg/kg, intraperitoneally (i.p.)), and the surface lead I electrocardiogram was continuously monitored. Administration of vasopressin (0.5 IU/kg, i.v.) to the rats depressed the S-wave level of the electrocardiogram, indicating the onset of subendocardial ischemia. However, pretreatment with tetramethylpyrazine suppressed the vasopressin-induced depression of the S-wave level, which was not observed following pretreatment with its vehicle alone (saline), suggesting that tetramethylpyrazine ameliorated the vasopressin-induced subendocardial ischemia in vivo. These results may provide experimental evidence for the empirically known clinical efficacy of tetramethylpyrazine against ischemic heart disease, and could provide clues to better understanding its in vivo mechanism of action.

Comparison of anti-anginal effect of cilnidipine with those of nicardipine and nifedipine in the vasopressin-induced angina model of rats.

We assessed the anti-anginal effects of cilnidipine in comparison with those of nicardipine and nifedipine (1 and 10 µg/kg, n = 6 for each drug) or vehicle (n = 6) by using the vasopressin-induced angina model of rats. The administration of vasopressin (0.5 IU/kg, i.v.) to the rats depressed the S-wave level of the electrocardiogram reflecting the presence of subendocardial ischemia, whereas it significantly increased the mean blood pressure, resulting in the decrease of the heart rate and the prolongation of the PR interval possibly through a reflex-mediated increase in vagal tone. Cilnidipine suppressed the vasopressin-induced depression of the S-wave level in a dose-related manner, which was not observed by nicardipine or nifedipine. In addition, the low dose of cilnidipine hardly affected the vasopressin-induced pressor response, but it attenuated the negative dromotropic effect, suggesting N-type Ca2+ channel inhibition by cilnidipine might have suppressed the parasympathetic nerve activity in vivo like those reported in the sympathetic nerve. Thus, cilnidipine may become a useful strategy for inhibiting coronary vasospasm-induced anginal attack.

A protocol of histone modification-based mechanistic study of acupuncture in patients with stable angina pectoris.

BACKGROUND: Angina pectoris (Angina) is a medical condition related to myocardial ischemia. Although acupuncture has been widely accepted as a clinical approach for angina, there is no sufficient evidence of its effectiveness against this syndrome, and its mechanisms have not yet been well elucidated. We develop this protocol to confirm the clinical efficacy of electro-acupuncture on stable angina pectoris by needling on acupoint Neiguan (PC6). Furthermore, we employ high-throughput sequencing technology to investigate the gene expression profiling and determine involvement of histone modifications in the regulation of genes after electro-acupuncture treatment. METHODS/DESIGN: A randomized, controlled, double-blinded (assessor and patients) trial will be carried out. Sixty participants will be randomly assigned to two acupuncture treatment groups and one control group in a 1:1:1 ratio. Participants in acupuncture groups will receive 12 sessions of electro-acupuncture treatment across 4 weeks, followed by a 12-week randomization period. The acupuncture groups are divided into Neiguan (PC6) on Pericardium Meridian of Hand-jueyin or a non-acupoint. The primary clinical measure of effect is the frequency of angina attacks between these groups for four weeks after randomization. RNAs are extracted from peripheral neutrophils collected from all participants on day 0, day 30, and week 16, and are processed to RNA-Seq. We then investigate profiles of histone modifications by ChIP-Seq, for H3 Lysine 4 (H3K4me) and acetylation of H3 Lysine 27 (H3K27ac), in the presence or absence of acupuncture treatment. DISCUSSION: This study determines the efficacy and mechanisms of electro-acupuncture on stable angina pectoris. We focus on effectiveness of acupuncture on alleviating symptoms of myocardial ischemia and the gene regulation and the chromatin remodeling marks, including H3K4me1, H3K4me2, and H3K27ac, which could be key factors for regulating gene expressions caused by electro-acupuncture treatment at Neiguan. This is the first genome-wide study of electro-acupuncture treatment in angina patients, and will provide valuable information for future studies in the fields of acupuncture and its underlying mechanisms. Fourteen patients have been recruited since recruitment opened in November of 2012. This study is scheduled to end in November of 2014. TRIALS REGISTRATION: ChiCTR-TRC-12002668.

Beneficial and Adverse Effects of Electro-acupuncture Assessed in the Canine Chronic Atrio-ventricular Block Model Having Severe Hypertension and Chronic Heart Failure.

Regarding the effects of electro-acupuncture for severe hypertension, we assessed its acute cardiovascular consequences with 4 subjects of the chronic atrioventricular block dogs having severe hypertension and chronic heart failure. The electro-acupuncture consisting of 2 mA at 2 Hz frequency was carried out for 30 min at Renying (ST-9) and Taichong (LR-3) every other day. Seven sessions were performed within 2 weeks. In the 1st and 7th sessions, the animals were anesthetized with pentobarbital to analyze the effects of the electro-acupuncture on cardiovascular variables. No significant change was detected in any of the basal control values of the cardiohemodynamic or electrophysiological variables between the 1st and 7th sessions. During the 1st session, electo-acupuncture produced a peak increase in mean blood pressure by 8.7% at 35 min (p < 0.05), whereas during the 7th session the peak increase was 6.5% at 35 min (p = 0.06). There was no significant change in the cardiac output, total peripheral resistance, a product of the heart rate and systolic blood pressure (= double product) reflecting myocardial oxygen consumption, QRS width or QT interval during the electrical stimulation in the 1st or 7th session. The results suggest that electroacupuncture may not exert lethal adverse effect except the vasopressor response, but that it can decrease the treatment-induced sympathetic response including vasopressor reaction and tachycardia. Since electro-acupuncture may have some potential to induce hypertensive crisis at the beginning, clinicians have to pay attention on its use for patients with hypertension.

Common parameters of acupuncture for the treatment of hypertension used in animal models.

Hypertension is associated with at least 7.6 million annual deaths worldwide. While pharmacotherapy may provide good control for blood pressure, it sometimes induces adverse effects. Meanwhile, acupuncture has been used for the treatment of cardiovascular diseases, such as hypertension, coronary artery disease, and stroke, but its mechanisms of actions remain poorly understood. The efficacy of acupuncture depends on multiple constituent elements including acupoints, manipulation skills, and implementation programs, which are termed as acupuncture prescription. This review summarized the previous information of experimental use of acupuncture on animals including species, hypertension models, acupoints selection, acupoint location, stimulation protocols, and evaluation of effectiveness to provide useful guidance for researchers when performing acupuncture in animal experiments.

Genome-wide analyses reveal the extent of opportunistic STAT5 binding that does not yield transcriptional activation of neighboring genes.

Signal Transducers and Activators of Transcription (STAT) 5A/B regulate cytokine-inducible genes upon binding to GAS motifs. It is not known what percentage of genes with GAS motifs bind to and are regulated by STAT5. Moreover, it is not clear whether genome-wide STAT5 binding is modulated by its concentration. To clarify these issues we established genome-wide STAT5 binding upon growth hormone (GH) stimulation of wild-type (WT) mouse embryonic fibroblasts (MEFs) and MEFs overexpressing STAT5A more than 20-fold. Upon GH stimulation, 23 827 and 111 939 STAT5A binding sites were detected in WT and STAT5A overexpressing MEFs, respectively. 13 278 and 71 561 peaks contained at least one GAS motif. 1586 and 8613 binding sites were located within 2.5 kb of promoter sequences, respectively. Stringent filtering revealed 78 genes in which the promoter/upstream region (-10 kb to +0.5 kb) was recognized by STAT5 both in WT and STAT5 overexpressing MEFs and 347 genes that bound STAT5 only in overexpressing cells. Genome-wide expression analyses identified that the majority of STAT5-bound genes was not under GH control. Up to 40% of STAT5-bound genes were not expressed. For the first time we demonstrate the magnitude of opportunistic genomic STAT5 binding that does not translate into transcriptional activation of neighboring genes.

Acupuncture promotes white adipose tissue browning by inducing UCP1 expression on DIO mice.

BACKGROUND: To study the influence of acupuncture and its possible mechanism on white adipose tissue of high fat diet-induced obese. METHODS: Four-week-old C57BL/6 J mice were randomly divided into a normal diet group and a high-fat diet (HFD) group. After 8 weeks, the HFD mice were randomly divided into Electro-acupuncture (EA) group and control group. Mice in the EA group were electro-acupunctured, under physical restraint, on Zusanli (ST36) and Neiting (ST44) acupoints, while the mice in the control group were under physical restraint only. Body weight and food intake were monitored, and serum leptin, cholesterol and triglyceride levels were measured by using biochemistrical methods. The effect of EA on white adipose tissues (WAT) was assessed by qPCR, immunoblotting, immunohistochemistry (IHC), immunoprecipitation and cold endurance experiment. RESULTS: The WAT/body weight ratio decreased (P < 0.05) in the EA group, albeit no significant difference on food consumption between EA and control groups. The difference in the darkness of Epi-WAT between EA and control groups could be distinguished visually. HE staining indicated that the EA mice had an increased number of UCP1-immunoreactive paucilocular adipocytes in their WAT. The expressions of brown adipose tissue (BAT) markers, including UCP1, COX4il and Nrtf1 were increased in the WAT of EA mice, acetylation of Pparγ was decreased by electro-acupuncture. CONCLUSION: EA can remodel WAT to BAT through inducing UCP1 expression, and this may be one of the mechanisms by which acupuncture affects weight loss.

Electro-acupuncture at Neiguan pretreatment alters genome-wide gene expressions and protects rat myocardium against ischemia-reperfusion.

This study investigated genome-wide gene expressions and the cardioprotective effects of electro-acupuncture pretreatment at the PC6 Neiguan acupoint on myocardial ischemia reperfusion (I/R) injury. Male SD rats were randomly divided into four groups: sham operation (SO), I/R, electro-acupuncture at the PC6 Neiguan acupoint pretreatment (EA) and electro-acupuncture at non-acupoint pretreatment (NA). Compared with the I/R group, the survival rate of the EA group was significantly increased, the arrhythmia score, infarction area, serum concentrations of CK, LDH and CK-Mb and plasma level of cTnT were significantly decreased. RNA-seq results showed that 725 genes were up-regulated and 861 genes were down-regulated under I/R conditions compared to the SO group; both EA and NA reversed some of these gene expression levels (592 in EA and 238 in NA group). KEGG pathway analysis indicated that these genes were involved in multiple pathways, including ECM, MAPK signaling, apoptosis, cytokine and leukocyte pathways. In addition, some pathways were uniquely regulated by EA, but not NA pretreatment, such as oxidative stress, cardiac muscle contraction, gap junction, vascular smooth muscle contraction, hypertrophic, NOD-like receptor, and P53 and B-cell receptor pathways. This study was first to reveal the gene expression signatures of acute myocardial I/R injury and electro-acupuncture pretreatment in rats.

The liver-specific tumor suppressor STAT5 controls expression of the reactive oxygen species-generating enzyme NOX4 and the proapoptotic proteins PUMA and BIM in mice.

UNLABELLED: Loss of signal transducer and activator of transcription 5 (STAT5) from liver tissue results in steatosis and enhanced cell proliferation. This study demonstrates that liver-specific Stat5-null mice develop severe hepatic steatosis as well as hepatocellular carcinomas at 17 months of age, even in the absence of chemical insults. To understand STAT5's role as a tumor suppressor, we identified and investigated new STAT5 target genes. Expression of Nox4, the gene encoding the reactive oxygen species (ROS)-generating enzyme NOX4, was induced by growth hormone through STAT5. In addition, the genes encoding the proapoptotic proteins PUMA and BIM were induced by growth hormone through STAT5, which bound to GAS motifs in the promoter regions of all three genes. We further show that STAT5-induced activation of Puma and Bim was dependent on NOX4. Treatment of mice with transforming growth factor-ß, an inducer of apoptosis, resulted in cleaved caspase-3 in control but not in liver-specific Stat5-null mice. This study demonstrates for the first time that cytokines through STAT5 regulate the expression of the ROS-generating enzyme NOX4 and key proapoptotic proteins. CONCLUSION: STAT5 harnesses several distinct signaling pathways in the liver and thereby functions as a tumor suppressor. Besides suppressing the activation of STAT3, STAT5 induces the expression of proapoptotic genes and the production of ROS.

[Anti-depressive effect of acupuncture on selective serotonin reuptake inhibitors].

OBJECTIVE: To evaluate anti-depressive effects of acupuncture on selective serotonin reuptake inhibitors (SSRIs). METHODS: Totally 60 patients with depression were randomly assigned to the control group (30 cases) and the treatment group (30 cases). All patients took one kind of SSRIs. Those in the treatment group were additionally treated by acupuncture. All were treated for 6 weeks. Patients' efficacies were evaluated with Hamilton Depression Scale (HAMD), Self-rating Depression Scale (SDS), and Eisenberg antidepressant side effects scale (Asberg). RESULTS: Compared with the control group after 6 weeks of treatment, the cured-markedly effective rate was improved by 33.4% in the treatment group (P < 0.05). The HAMD was lower in the treatment group. The tendency of interaction of sleep disorder factor and anxiety/somatization factor was different between at the end of 1-week treatment and at the end of 6-week treatment in the treatment group (P < 0.05). The SDS score decreased at the end of 6-week treatment in the treatment group. The reduction rate was elevated by 19.23% (P < 0.05). By the end of 6-week treatment, the average score of Asberg decreased by 3.77 score in average in the treatment group, while it decreased by 0.07 score in average in the control group (P < 0.05). CONCLUSION: Acupuncture could effectively improve anti-depressive effects of SSRIs and reduce their adverse reactions.

Regulation of the JAK/STAT signaling pathway: The promising targets for cardiovascular disease.

Individuals have known that Janus kinase (JAK) signal transducer and activator of transcription (STAT) signaling pathway was involved in the growth of the cell, cell differentiation courses advancement, immune cellular survival, as well as hematopoietic system advancement. Researches in the animal models have already uncovered a JAK/STAT regulatory function in myocardial ischemia-reperfusion injury (MIRI), acute myocardial infarction (MI), hypertension, myocarditis, heart failure, angiogenesis and fibrosis. Evidences originating in these studies indicate a therapeutic JAK/STAT function in cardiovascular diseases (CVDs). In this retrospection, various JAK/STAT functions in the normal and ill hearts were described. Moreover, the latest figures about JAK/STAT were summarized under the background of CVDs. Finally, we discussed the clinical transformation prospects and technical limitations of JAK/STAT as the potential therapeutic targets for CVDs. This collection of evidences has essential meanings for the clinical application of JAK/STAT as medicinal agents for CVDs. In this retrospection, various JAK/STAT functions in the normal and ill hearts were described. Moreover, the latest figures about JAK/STAT were summarized under the background of CVDs. Finally, we discussed the clinical transformation prospects and toxicity of JAK/STAT inhibitors as potential therapeutic targets for CVDs. This collection of evidences has essential meanings for the clinical application of JAK/STAT as medicinal agents for CVDs.

Evaluation of time-dependent phenotypes of myocardial ischemia-reperfusion in mice.

BACKGROUND: A mouse model of myocardial ischemia-reperfusion (I/R) is widely used to study myocardial ischemia-reperfusion injury (I/RI). However, few studies focus on the direct comparison of the extent of pathological events resulting from variant durations of ischemia and reperfusion process. METHODS: A mouse model of I/RI was established by ligation and perfusion of the left anterior descending coronary artery (LAD), and the dynamic changes were recorded by electrocardiogram at different stages of I/R. Subsequently, reperfusion duration was used as a variable to directly compare the phenotypes of different myocardial injury degrees induced by 3 h, 6 h and 24 h reperfusion from myocardial infarct size, myocardial apoptosis, myocardial enzyme, and inflammatory cytokine levels. RESULTS: All mice subjected to myocardial I/R surgery showed obvious myocardial infarction, extensive myocardial apoptosis, dynamic changes in serum myocardial enzyme and inflammatory cytokines, at least for the first 24 h of reperfusion. The infarct size and apoptosis rates gradually increased with the extension of reperfusion time. The peaks of serum myocardial enzyme and inflammatory cytokines occurred at 6 h and 3 h of reperfusion, respectively. We also established I/R mice models with 30 and 60 mins of ischemia. After 21 days of remodeling, longer periods of ischemia increased the degree of fibrosis and reduced cardiac function. CONCLUSIONS: In summary, we conclude that reperfusion durations of 3 h, 6 h, and 24 h induces different injury phenotypes in ischemia-reperfusion mouse model. At the same time, the ischemia duration before reperfusion also affects the degree of cardiac remodeling.

Human Adipose-Derived Mesenchymal Stem Cell-Based Microspheres Ameliorate Atherosclerosis Progression In Vitro.

Atherosclerosis (AS) is a chronic inflammatory disease associated with lipid deposition, which could be converted into acute clinical events by thrombosis or plaque rupture. Adipose-derived mesenchymal stem cell (ADSC)-encapsulated repair units could be an effective cure for the treatment of AS patients. In this study, we encapsulate human adipose-derived mesenchymal stem cells (hADSCs) in collagen microspheres to fabricate stem cell repair units. Besides, we show that encapsulation in collagen microspheres and cultured in vitro for 14 days maintain the viability and stemness of hADSCs. Moreover, we generate AS progression model and niche in vitro by combining hyperlipemia serum of AS patients with AS cell models. We further systematically demonstrate that hADSC-based microspheres could ameliorate AS progression by inhibiting oxidative stress injury, cell apoptosis, endothelial dysfunction, inflammation, and lipid accumulation. In addition, we perform transcriptomic analysis and functional studies to demonstrate how hADSCs (three dimensional cultured in microspheres) respond to AS niche compared with healthy microenvironment. These findings reveal a role for ADSC-based microspheres in the treatment of AS and provide new ideas for stem cell therapy in cardiovascular disease. The results may have implications for improving the efficiency of hADSC therapies by illuminating the mechanisms of hADSCs exposed in special pathological niche.

Loss of Histone Methyltransferase KMT2D Attenuates Angiogenesis in the Ischemic Heart by Inhibiting the Transcriptional Activation of VEGF-A.

Angiogenesis occurred after myocardial infarction (MI) protects heart failure (HF). The aim of our study was to explore function of histone methyltransferase KMT2D (MLL4, mixed-lineage leukemia 4) in angiogenesis post-MI. Western blotting showed that KMT2D protein expression was elevated in MI mouse myocardial. Cardiomyocyte-specific Kmt2d-knockout (Kmt2d-cKO) mice were generated, and echocardiography and immunofluorescence staining detected significantly attenuated cardiac function and insufficient angiogenesis following MI in Kmt2d-cKO mice. Cross-talk assay suggested that Kmt2d-KO H9c2-derived conditioned medium attenuates EA.hy926 EC function. ELISA further identified that VEGF-A released from Kmt2d-KO H9c2 was significantly reduced. CUT&Tag and RT-qPCR revealed that KMT2D deficiency reduced Vegf-a mRNA expression and enrichment of H3K4me1 on the Vegf-a promoter. Moreover, KMT2D silencing in ECs also suppressed endothelial function. Our study indicates that KMT2D depletion in both cardiomyocytes and ECs attenuates angiogenesis and that loss of KMT2D exacerbates heart failure after MI in mice.