Jeon, Ryoung‐Hoon

Abstract Cardiopoiesis-primed human stem cells exert sustained benefit in treating heart failure despite limited retention following myocardial delivery. To assess potential paracrine contribution, the secretome of cardiopoiesis conditioned versus naïve human mesenchymal stromal cells was decoded by directed proteomics augmented with machine learning and systems interrogation. Cardiopoiesis doubled cellular protein output generating a distinct secretome that segregated the conditioned state. Altering the expression of 1035 secreted proteins, cardiopoiesis reshaped the secretome across functional classes. The resolved differential cardiopoietic secretome was enriched in mesoderm development and cardiac progenitor signaling processes, yielding a cardiovasculogenic profile bolstered by upregulated cardiogenic proteins. In tandem, cardiopoiesis enhanced the secretion of immunomodulatory proteins associated with cytokine signaling, leukocyte migration, and chemotaxis. Network analysis integrated the differential secretome within an interactome of 1745 molecules featuring prioritized regenerative processes. Secretome contribution to the repair signature of cardiopoietic cell-treated infarcted hearts was assessed in a murine coronary ligation model. Intramyocardial delivery of cardiopoietic cells improved the performance of failing hearts, with undirected proteomics revealing 50 myocardial proteins responsive to cell therapy. Pathway analysis linked the secretome to cardiac proteome remodeling, pinpointing 17 cardiopoiesis-upregulated secretome proteins directly upstream of 44% of the cell therapy-responsive cardiac proteome. Knockout, in silico, of this 22-protein secretome-dependent myocardial ensemble eliminated indices of the repair signature. Accordingly, in vivo, cell therapy rendered the secretome-dependent myocardial proteome of an infarcted heart indiscernible from healthy counterparts. Thus, the secretagogue effect of cardiopoiesis transforms the human stem cell secretome, endows regenerative competency, and upregulates candidate paracrine effectors of cell therapy-mediated molecular restitution.

Abstract Glycolysis is essential for the classical activation of macrophages (M1), but how glycolytic pathway metabolites engage in this process remains to be elucidated. Glycolysis culminates in the production of pyruvate, which can be transported into the mitochondria by the mitochondrial pyruvate carrier (MPC) followed by conversion to citrate and utilization in the TCA cycle. Alternatively, pyruvate can be metabolized to lactate under aerobic conditions, which had been considered to be the dominant route in the setting of classical macrophage activation. However, based on studies that used UK5099 as a MPC inhibitor and showed reduction in key inflammatory cytokines, the mitochondrial route has been considered to be of significance for M1 activation as well. Herein, using a genetic depletion model, we found that MPC is dispensable for metabolic reprogramming and the activation of M1. In addition, MPC depletion in myeloid cells has no impact on inflammatory responses and macrophage polarization toward M1 phenotype in the endotoxemia mice model. While UK5099 reaches maximal MPC inhibitory capacity at approximately 2–5µM, higher concentrations are required to inhibit inflammatory cytokine production in M1 and this is independent of MPC expression. Taken together, this study found MPC-mediated metabolism is dispensable for the classical activation of macrophages, and UK5099 inhibits inflammatory responses in M1 macrophages due to effects other than MPC inhibition.

Abstract Glycolysis is essential for the classical activation of macrophages (M1), but how glycolytic pathway metabolites engage in this process remains to be elucidated. Glycolysis culminates in the production of pyruvate, which can be transported into the mitochondria by the mitochondrial pyruvate carrier (MPC) followed by conversion to citrate and utilization in the TCA cycle. Alternatively, pyruvate can be metabolized to lactate under aerobic conditions, which had been considered to be the dominant route in the setting of classical macrophage activation. However, based on studies that used UK5099 as a MPC inhibitor and showed reduction in key inflammatory cytokines, the mitochondrial route has been considered to be of significance for M1 activation as well. Herein, using a genetic depletion model, we found that MPC is dispensable for metabolic reprogramming and the activation of M1. While UK5099 reaches maximal MPC inhibitory capacity at approximately 2–5µM, higher concentrations are required to inhibit inflammatory cytokine production in M1 and this is independent of MPC expression. Apart from MPC inhibition, UK5099 at high doses impairs glutamate oxidation, mitochondrial membrane potential and HIF-1α stabilization. Taken together, UK5099 inhibits inflammatory responses in M1 macrophages due to effects other than MPC inhibition.

Abstract Stem cell paracrine activity is implicated in cardiac repair. Linkage between secretome functionality and therapeutic outcome was here interrogated by systems analytics of biobanked human cardiopoietic cells, a regenerative biologic in advanced clinical trials. Protein chip array identified 155 proteins differentially secreted by cardiopoietic cells with clinical benefit, expanded into a 520 node network, collectively revealing inherent vasculogenic properties along with cardiac and smooth muscle differentiation and development. Next generation RNA sequencing, refined by pathway analysis, pinpointed miR-146 dependent regulation upstream of the decoded secretome. Intracellular and extracellular integration unmasked commonality across cardio-vasculogenic processes. Mirroring the secretome pattern, infarcted hearts benefiting from cardiopoietic cell therapy restored the disease proteome engaging cardiovascular system functions. The cardiopoietic cell secretome thus confers a therapeutic molecular imprint on recipient hearts, with response informed by predictive systems profiling.

Sarcolemmal α2 adrenoceptors (α2-AR), represented by α2A, α2B and α2C isoforms, can safeguard cardiac muscle under sympathoadrenergic surge by governing Ca2+ handling and contractility of cardiomyocytes. Cardiomyocyte-specific targeting of α2-AR would provide cardiac muscle-delimited stress control and enhance the efficacy of cardiac malfunction treatments. However, little is known about the specific contribution of the α2-AR subtypes in modulating cardiomyocyte functions. Herein, we analyzed the expression profile of α2A, α2B and α2C subtypes in mouse ventricle and conducted electrophysiological antagonist assay evaluating the contribution of these isoforms to the suppression of L-type Ca2+ current (ICaL). Patch-clamp electro-pharmacological studies revealed that the α2-agonist-induced suppression of ICaL involves mainly the α2C, to a lesser extent the α2B, and not the α2A isoforms. RT-qPCR evaluation revealed the presence of adra2b and adra2c (α2B and α2C isoform genes, respectively), but was unable to identify the expression of adra2a (α2A isoform gene) in the mouse left ventricle. Immunoblotting confirmed the presence only of the α2B and the α2C proteins in this tissue. The identified α2-AR isoform-linked regulation of ICaL in the mouse ventricle provides an important molecular substrate for the cardioprotective targeting.

Abstract To optimize the regenerative proficiency of stem cells, a cardiopoietic protein-based cocktail consisting of multiple growth factors has been developed and advanced into clinical trials for treatment of ischemic heart failure. Streamlining the inductors of cardiopoiesis would address the resource intensive nature of the current stem cell enhancement protocol. To this end, the microencapsulated-modified-mRNA (M3RNA) technique was here applied to introduce early cardiogenic genes into human adipose-derived mesenchymal stem cells (AMSCs). A single mesodermal transcription factor, Brachyury, was sufficient to trigger high expression of cardiopoietic markers, Nkx2.5 and Mef2c. Engineered cardiopoietic stem cells (eCP) featured a transcriptome profile distinct from pre-engineered AMSCs. In vitro, eCP demonstrated protective antioxidant capacity with enhanced superoxide dismutase expression and activity; a vasculogenic secretome driving angiogenic tube formation; and macrophage polarizing immunomodulatory properties. In vivo, in a murine model of myocardial infarction, intramyocardial delivery of eCP (600 000 cells per heart) improved cardiac performance and protected against decompensated heart failure. Thus, heart repair competent stem cells, armed with antioxidant, vasculogenic, and immunomodulatory traits, are here engineered through a protein-independent single gene manipulation, expanding the available regenerative toolkit.

Diabetes is a metabolic disease which affects not only glucose metabolism but also lipid and protein metabolism. It encompasses two major types: type 1 and 2 diabetes. Despite the different etiologies of type 1 and 2 diabetes mellitus (T1DM and T2DM, respectively), the defining features of the two forms are insulin deficiency and resistance, respectively. Stem cell therapy is an efficient method for the treatment of diabetes, which can be achieved by differentiating pancreatic β-like cells. The consistent generation of glucose-responsive insulin releasing cells remains challenging. In this review article, we present basic concepts of pancreatic organogenesis, which intermittently provides a basis for engineering differentiation procedures, mainly based on the use of small molecules. Small molecules are more auspicious than any other growth factors, as they have unique, valuable properties like cell-permeability, as well as a nonimmunogenic nature; furthermore, they offer immense benefits in terms of generating efficient functional beta-like cells. We also summarize advances in the generation of stem cell-derived pancreatic cell lineages, especially endocrine β-like cells or islet organoids. The successful induction of stem cells depends on the quantity and quality of available stem cells and the efficient use of small molecules.