Intramyocardial Injected Human Umbilical Cord-Derived Mesenchymal Stem Cells (Hucmscs ) Contribute to the Recovery of Cardiac Function and the Migration of CD4+ T Cells into the Infarcted Heart via CCL5/CCR5 Signaling

Background: Human umbilical cord-derived mesenchymal stem cells (HucMSCs) have been recognized as a promising cell for treating myocardial infarction (MI). Inflammatory response post MI is critical in determining the cardiac function and subsequent adverse left ventricular remodeling. However, the local inflammatory effect of HucMSCs after intramyocardial injection in murine remains unclear. Methods: HucMSCs were cultured and transplanted into the mice after MI surgery. Cardiac function, angiogenesis, fibrosis and hypertrophy, and immune cells infiltration were evaluated between MI-N.S and MI-HucMSC groups. We detected the expression of inflammatory cytokines and their effects on CD4+ T cells migration. Results: HucMSCs treatment can significantly improve the cardiac function and some cells can survive at least 28 days after MI. Intramyocardial administration of HucMSCs also improved angiogenesis and alleviated cardiac fibrosis and hypertrophy. Moreover, we found the much higher numbers of CD4+ T cells and CD4+FoxP3+ regulatory T cells in the heart with HucMSC than that with N.S treatment on day 7 post MI. In addition, the protein level of C-C Motif Chemokine Ligand 5 (CCL5) greatly increased in the HucMSCs treated heart compared to the control. In vitro, HucMSCs inhibited CD4+ T cells migration and addition of CCL5 antibody or C-C Motif Chemokine receptor 5 (CCR5) antagonist significantly reversed this effect. Conclusion: These findings indicated that HucMSCs contributed to cardiac functional recovery and attenuated cardiac remodeling post MI. Intramyocardial injection of HucMSCs upregulated the CD4+FoxP3+ regulatory T cells and contributed to the migration of CD4+ T cells into the injured heart via CCL5/CCR5 pathway.

Tanshinone ⅡA Enhances the Therapeutic Efficacy of Mesenchymal Stem Cells Derived Exosomes in Myocardial Ischemia/reperfusion Injury via Up-regulating miR-223-5p

Background: Myocardial ischemia-reperfusion (I/R) injury is a serious obstacle for patients with coronary heart disease to benefit from post-ischemic reflow. After myocardial I/R injury, CCR2+-resident macrophages are rapidly activated and participate in the subsequent inflammatory response, whereas CCR2--resident macrophages play a major role in attenuating cardiac inflammation and promoting tissue repair. Mesenchymal stem cells (MSCs) have gradually become attractive candidates that aid in understanding the pathogenesis and progression of cardiovascular diseases. The low immunogenicity and low carcinogenicity of stem cell-derived exosomes offer advantage in treating myocardial injuries. In this study, we investigated whether MSC-derived exosomes pretreated with tanshinone IIA (TSA) could exhibit stronger cardioprotective function in an I/R rat model and explored its underlying mechanism. Methods: We investigated the effect of TSA-MSCexo on myocardial I/R injury in vivo. The overexpression of CCR2 in the rat heart was used to determine the regulatory role of CCR2 in I/R injury. High-throughput sequencing of MSCexo and TSA-MSCexo to screen differential genes to explore the mechanism of TSA-MSCexo's cardioprotective effect. Results: Compared with MSCexo, an intramyocardial injection of TSA-MSCexo was found to be more effective in rats in improving cardiac function, limiting the infarct size, inhibiting CCR2 activation, reducing monocyte infiltration and promoting angiogenesis in the heart after myocardial I/R. Moreover, CCR2 had a regulatory effect on monocyte infiltration and angiogenesis after I/R. Bioinformatics analysis and miRNA sequencing of MSCexo and TSA-MSCexo revealed miR-223-5p an effective candidate mediator for TSA-MSCexo to exert its cardioprotective function and CCR2 as the downstream target. Conclusion: In summary, our findings indicated that miR-223-5p packaged in TSA-MSCexo inhibited CCR2 activation to reduce monocyte infiltration and enhanced angiogenesis to alleviate myocardial I/R injury in rats. Thus, the development of an alternative therapy of TSA combined with stem cell-derived exosomes provides an effective strategy for the clinical therapies of ischemic cardiomyopathy.

Cardiac Repair With Echocardiography-Guided Multiple Percutaneous Left Ventricular Intramyocardial Injection of hiPSC-CMs After Myocardial Infarction

Objective: We investigated the potency of cardiac repair based on echocardiography-guided multiple percutaneous left ventricular intramyocardial injection of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) after myocardial infarction (MI).Methods: Mice with surgically induced MI were randomly divided into three groups (n = 8 in each group) and subjected to echocardiography-guided percutaneous left ventricular infarcted border injection of hiPSC-CMs (single dose; 10 μl 3 × 105 cells) or repeated injections of hiPSC-CMs at post-MI weeks 1 and 2 (multiple doses). The sham group of animals underwent all surgical procedures necessary for MI induction except for ligation. Then 4 weeks after MI, heart function was measured with transthoracic echocardiography. Engraftment was evaluated through the detection of human-specific cardiac troponin T. Infarct size and collagen volume were calculated with Sirius Red/Fast Green staining. Angiogenesis was evaluated with isolectin B4 staining. Cardiac remodeling was evaluated from the cardiomyocyte minimal fiber diameter in the infarcted border zone. Apoptosis was detected via TdT-mediated dUTP Nick-End Labeling (TUNEL) staining in cardiomyocytes from the infarcted border zone.Results: No mice died after echocardiography-guided percutaneous left ventricular intramyocardial injection. hiPSC-CMs were about nine-fold higher in the multiple-dose group at week 4 compared to the single-dose group. Multiple-dose transplantation was associated with significant improvement in left ventricular function, infarct size, angiogenesis, cardiac remodeling, and cardiomyocyte apoptosis.Conclusion: Echocardiography-guided multiple percutaneous left ventricular intramyocardial injection is a feasible, satisfactory, repeatable, relatively less invasive, and effective method of delivering cell therapy. The delivery of hiPSC-CMs indicates a novel therapy for MI.

Intramyocardial injection of human adipose-derived stem cells ameliorates cognitive deficit by regulating oxidative stress–mediated hippocampal damage after myocardial infarction

Cognitive impairment is a serious side effect of post-myocardial infarction (MI) course. We have recently demonstrated that human adipose-derived stem cells (hADSCs) ameliorated myocardial injury after MI by attenuating reactive oxygen species (ROS) levels. Here, we studied whether the beneficial effects of intramyocardial hADSC transplantation can extend to the brain and how they may attenuate cognitive dysfunction via modulating ROS after MI. After coronary ligation, male Wistar rats were randomized via an intramyocardial route to receive either vehicle, hADSC transplantation (1 × 106 cells), or the combination of hADSCs and 3-Morpholinosydnonimine (SIN-1, a peroxynitrite donor). Whether hADSCs migrated into the hippocampus was assessed by using human-specific primers in qPCR reactions. Passive avoidance test was used to assess cognitive performance. Postinfarction was associated with increased oxidative stress in the myocardium, circulation, and hippocampus. This was coupled with decreased numbers of dendritic spines as well as a significant downregulation of synaptic plasticity consisting of synaptophysin and PSD95. Step-through latency during passive avoidance test was impaired in vehicle-treated rats after MI. Intramyocardial hADSC injection exerted therapeutic benefits in improving cardiac function and cognitive impairment. None of hADSCs was detected in rat’s hippocampus at the 3rd day after intramyocardial injection. The beneficial effects of hADSCs on MI-induced histological and cognitive changes were abolished after adding SIN-1. MI-induced ROS attacked the hippocampus to induce neurodegeneration, resulting in cognitive deficit. The remotely intramyocardial administration of hADSCs has the capacity of improved synaptic neuroplasticity in the hippocampus mediated by ROS, not the cell engraftment, after MI. Key messages Human adipose-derived stem cells (hADSCs) ameliorated injury after myocardial infarction by attenuating reactive oxygen species (ROS) levels. Intramyocardial administration of hADSCs remotely exerted therapeutic benefits in improving cognitive impairment after myocardial infarction. The improved synaptic neuroplasticity in the hippocampus was mediated by hADSC-inhibiting ROS, not by the stem cell engraftment.

Early activation of the cardiac CX3CL1/CX3CR1 axis delays β-adrenergic-induced heart failure

We recently highlighted a novel potential protective paracrine role of cardiac myeloid CD11b/c cells improving resistance of adult hypertrophied cardiomyocytes to oxidative stress and potentially delaying evolution towards heart failure (HF) in response to early β-adrenergic stimulation. Here we characterized macrophages (Mφ) in hearts early infused with isoproterenol as compared to control and failing hearts and evaluated the role of upregulated CX3CL1 in cardiac remodeling. Flow cytometry, immunohistology and Mφ-depletion experiments evidenced a transient increase in Mφ number in isoproterenol-infused hearts, proportional to early concentric hypertrophy (ECH) remodeling and limiting HF. Combining transcriptomic and secretomic approaches we characterized Mφ-enriched CD45+ cells from ECH hearts as CX3CL1- and TNFα-secreting cells. In-vivo experiments, using intramyocardial injection in ECH hearts of either Cx3cl1 or Cx3cr1 siRNA, or Cx3cr1−/− knockout mice, identified the CX3CL1/CX3CR1 axis as a protective pathway delaying transition to HF. In-vitro results showed that CX3CL1 not only enhanced ECH Mφ proliferation and expansion but also supported adult cardiomyocyte hypertrophy via a synergistic action with TNFα. Our data underscore the in-vivo transient protective role of the CX3CL1/CX3CR1 axis in ECH remodeling and suggest the participation of CX3CL1-secreting Mφ and their crosstalk with CX3CR1-expressing cardiomyocytes to delay HF.

Abstract MP206: Cortical Bone Derived Stem Cells Modulate The Adaptive Immune Response Post-MI

Background: The inflammatory response mounted following myocardial infarction (MI) is closely coupled to myocardial wound healing processes such as angiogenesis, fibroblast maturation, and cardiomyocyte survival. A consortium of pro-reparative Tregs occupy the myocardium during ischemic injury and are essential in modulating cardiac homeostasis. However, Treg exposure to chronic, ischemic microenvironments compromises Tregs’ pro-reparative signatures and induces pathogenic remodeling of Tregs, compromising cardiac wound healing. Cortical Bone Derived Stem Cells (CBSCs) have superior engraftment capabilities compared to other stem cell types and can modulate the post-MI inflammatory response by establishing anti-inflammatory paracrine signaling dominance and the expansion of CD45+ leukocytes and CD4+ T cells residence in the MI heart. Therefore, we hypothesized CBSC cell therapy can modulate the recruitment and phenotype of Treg residence in the MI heart to permit their enhanced cardiogenic properties. Methods and Results: Animals that received intramyocardial injection of CBSCs along the infarct border zone of the permanently ligated LAD possessed smaller infarct sizes and improved cardiac function, that paralleled pro-reparative, TNFRII+ Treg expansion and repressed pathogenic TNFRI+, Treg residence 1- and 8- weeks post-MI compared to Mesenchymal Stem Cells (MSCs) or vehicle (PBS) treated animals. Similar TNFRI/II Treg dynamics were also observed in the spleen. Diphtheria toxin (DTR) mediated Treg ablation and S1P1 agonist administration, in the presence of CBSC therapy, reverted pro-reparative Treg expansion and solicited infarct size expansion and compromised cardiac function. The exposure of CBSC paracrine secretome to naïve CD4+ T cell cultures induces pro-reparative TNFRII+ Treg expansion. Paracrine profiling of CBSC secretome identifies Osteoprotegerin (OPG) enrichment and OPG depletion, via siRNA and lentivirus, compromises T cell survival signaling and pro-reparative, TNFRII+ Treg establishment both in vitro and in the MI heart. Conclusions: CBSCs can modulate the induction and preservation of pro-reparative TNFRII+ Tregs in the MI heart to solicit cardiac repair during acute and chronic ischemic injury.

Near Complete Repair After Myocardial Infarction in Adult Mice by Altering the Inflammatory Response With Intramyocardial Injection of α-Gal Nanoparticles

Background: Neonatal mice, but not older mice, can regenerate their hearts after myocardial-infarction (MI), a process mediated by pro-reparative macrophages. α-Gal nanoparticles applied to skin wounds in adult-mice bind the anti-Gal antibody, activate the complement cascade and generate complement chemotactic peptides that recruit pro-reparative macrophages which are further activated by these nanoparticles. The recruited macrophages decrease wound healing time by ~50%, restore the normal skin structure and prevent fibrosis and scar formation in mice.Objectives: The objective of this study is to determine if α-gal nanoparticles injected into the reperfused myocardium after MI in adult-mice can induce myocardial repair that restores normal structure, similar to that observed in skin injuries.Methods and Results: MI was induced by occluding the mid-portion of the left anterior descending (LAD) coronary artery for 30 min. Immediately following reperfusion, each mouse received two 10 μl injections of 100 μg α-gal nanoparticles in saline into the LAD territory (n = 20), or saline for controls (n = 10). Myocardial infarct size was measured by planimetry following Trichrome staining and macrophage recruitment by hematoxylin-eosin staining. Left ventricular (LV) function was measured by echocardiography. Control mice displayed peak macrophage infiltration at 4-days, whereas treated mice had a delayed peak macrophage infiltration at 7-days. At 28-days, control mice demonstrated large transmural infarcts with extensive scar formation and poor contractile function. In contrast, mice treated with α-gal nanoparticles demonstrated after 28-days a marked reduction in infarct size (~10-fold smaller), restoration of normal myocardium structure and contractile function.Conclusions: Intramyocardial injection of α-gal nanoparticles post-MI in anti-Gal producing adult-mice results in near complete repair of the infarcted territory, with restoration of normal LV structure and contractile function. The mechanism responsible for this benefit likely involves alteration of the usual inflammatory response post-MI, as previously observed with regeneration of injured hearts in adult zebrafish, salamanders and neonatal mice.

Electrophysiological engineering of heart-derived cells with calcium-dependent potassium channels improves cell therapy efficacy for cardioprotection

We have shown that calcium-activated potassium (KCa)-channels regulate fundamental progenitor-cell functions, including proliferation, but their contribution to cell-therapy effectiveness is unknown. Here, we test the participation of KCa-channels in human heart explant-derived cell (EDC) physiology and therapeutic potential. TRAM34-sensitive KCa3.1-channels, encoded by the KCNN4 gene, are exclusively expressed in therapeutically bioactive EDC subfractions and maintain a strongly polarized resting potential; whereas therapeutically inert EDCs lack KCa3.1 channels and exhibit depolarized resting potentials. Somatic gene transfer of KCNN4 results in membrane hyperpolarization and increases intracellular [Ca2+], which boosts cell-proliferation and the production of pro-healing cytokines/nanoparticles. Intramyocardial injection of EDCs after KCNN4-gene overexpression markedly increases the salutary effects of EDCs on cardiac function, viable myocardium and peri-infarct neovascularization in a well-established murine model of ischemic cardiomyopathy. Thus, electrophysiological engineering provides a potentially valuable strategy to improve the therapeutic value of progenitor cells for cardioprotection and possibly other indications.

Myocardial fibrosis reversion via rhACE2-electrospun fibrous patch for ventricular remodeling prevention

Myocardial fibrosis and ventricular remodeling were the key pathology factors causing undesirable consequence after myocardial infarction. However, an efficient therapeutic method remains unclear, partly due to difficulty in continuously preventing neurohormonal overactivation and potential disadvantages of cell therapy for clinical practice. In this study, a rhACE2-electrospun fibrous patch with sustained releasing of rhACE2 to shape an induction transformation niche in situ was introduced, through micro-sol electrospinning technologies. A durable releasing pattern of rhACE2 encapsulated in hyaluronic acid (HA)—poly(L-lactic acid) (PLLA) core-shell structure was observed. By multiple in vitro studies, the rhACE2 patch demonstrated effectiveness in reducing cardiomyocytes apoptosis under hypoxia stress and inhibiting cardiac fibroblasts proliferation, which gave evidence for its in vivo efficacy. For striking mice myocardial infarction experiments, a successful prevention of adverse ventricular remodeling has been demonstrated, reflecting by improved ejection fraction, normal ventricle structure and less fibrosis. The rhACE2 patch niche showed clear superiority in long term function and structure preservation after ischemia compared with intramyocardial injection. Thus, the micro-sol electrospun rhACE2 fibrous patch niche was proved to be efficient, cost-effective and easy-to-use in preventing ventricular adverse remodeling.

Intramyocardial Injection of Human Adipose-Derived Stem Cells Ameliorates Cognitive Deficit By Regulating Oxidative Stress-Mediated Hippocampal Damage After Myocardial Infarction

Cognitive impairment is a serious side effect of post-myocardial infarction (MI) course. We have recently demonstrated that human adipose-derived stem cells (hADSCs) ameliorated myocardial injury after MI by attenuating reactive oxygen species (ROS) levels. Here, we studied whether the beneficial effects of intramyocardial hADSC transplantation can extend to the brain and how they may attenuate cognitive dysfunction via modulating ROS after MI. After coronary ligation, male Wistar rats were randomized via an intramyocardial route to receive either vehicle, hADSC transplantation (1x106 cells), or the combination of hADSCs and 3-Morpholinosydnonimine (SIN-1, a peroxynitrite donor). Whether hADSCs migrated into the hippocampus was assessed by using human-specific primers in qPCR reactions. Passive avoidance test was used to assess cognitive performance. Postinfarction was associated with increased oxidative stress in myocardium, circulation and hippocampus. This was coupled with decreased numbers of dendritic spines as well as a significant downregulation of synaptic plasticity consisting of synaptophysin and PSD95. Step through latency during passive avoidance test was impaired in vehicle-treated rats after MI. Intramyocardial hADSC injection exerted therapeutic benefits in improving cardiac function and cognitive impairment. None of hADSCs were detected in rat’s hippocampus at the 3th day after intramyocardial injection. The beneficial effects of hADSCs on MI-induced histological and cognitive changes were abolished after adding SIN-1. MI-induced ROS attacked the hippocampus to induce neurodegeneration, resulting in cognitive deficit. The remotely intramyocardial administration of hADSCs, has the capacity of improved synaptic neuroplasticity in hippocampus mediated by ROS, not the cell engraftment, after MI.