Sphingosine 1-phosphate promotes mesenchymal stem cell-mediated cardioprotection against myocardial infarction via ERK1/2-MMP-9 and Akt signaling axis

1-Phosphate receptor agonists: A promising therapeutic avenue for ischemia-reperfusion injury management

Ischemia-reperfusion injury (IRI) - a complex pathological condition occurring when blood supply is abruptly restored to ischemic tissues, leading to further tissue damage - poses a significant clinical challenge. Sphingosine-1-phosphate receptors (S1PRs), a specialized set of G-protein-coupled receptors comprising five subtypes (S1PR1 to S1PR5), are prominently present in various cell membranes, including those of lymphocytes, cardiac myocytes, and endothelial cells. Increasing evidence highlights the potential of targeting S1PRs for IRI therapeutic intervention. Notably, preconditioning and postconditioning strategies involving S1PR agonists like FTY720 have demonstrated efficacy in mitigating IRI. As the synthesis of a diverse array of S1PR agonists continues, with FTY720 being a prime example, the body of experimental evidence advocating for their role in IRI treatment is expanding. Despite this progress, comprehensive reviews delineating the therapeutic landscape of S1PR agonists in IRI remain limited. This review aspires to meticulously elucidate the protective roles and mechanisms of S1PR agonists in preventing and managing IRI affecting various organs, including the heart, kidney, liver, lungs, intestines, and brain, to foster novel pharmacological approaches in clinical settings.

The dual role of mesenchymal stem cells in apoptosis regulation

Mesenchymal stem cells (MSCs) are widely distributed pluripotent stem cells with powerful immunomodulatory capacity. MSCs transplantation therapy (MSCT) is widely used in the fields of tissue regeneration and repair, and treatment of inflammatory diseases. Apoptosis is an important way for tissues to maintain cell renewal, but it also plays an important role in various diseases. And many studies have shown that MSCs improves the diseases by regulating cell apoptosis. The regulation of MSCs on apoptosis is double-sided. On the one hand, MSCs significantly inhibit the apoptosis of diseased cells. On the other hand, MSCs also promote the apoptosis of tumor cells and excessive immune cells. Furthermore, MSCs regulate apoptosis through multiple molecules and pathways, including three classical apoptotic signaling pathways and other pathways. In this review, we summarize the current evidence on the regulation of apoptosis by MSCs.

TET2 mutation as prototypic clonal hematopoiesis lesion

Loss of function TET2 mutation (TET2MT) is one of the most frequently observed lesions in clonal hematopoiesis (CH). TET2 a member TET-dioxygenase family of enzymes that along with TET1 and TET3, progressively oxidize 5-methyl cytosine (mC) resulting in regulated demethylation of promoter, enhancer and silencer elements of the genome. This process is critical for efficient transcription that determine cell lineage fate, proliferation and survival and the maintenance of the genomic fidelity with aging of the organism. Partial or complete loss-of-function TET2 mutations create regional and contextual DNA hypermethylation leading to gene silencing or activation that result in skewed myeloid differentiation and clonal expansion. In addition to myeloid skewing, loss of TET2 creates differentiation block and provides proliferative advantage to hematopoietic stem and progenitor cells (HSPCs). TET2MT is a prototypical lesion in CH, since the mutant clones dominate during stress hematopoiesis and often associates with evolution of myeloid malignancies. TET2MT clones has unique privilege to create and persist in pro-inflammatory milieu. Despite extensive knowledge regarding biochemical mechanisms underlying distorted myeloid differentiation, and enhanced self-replication of TET2MT HSPC, the mechanistic link of various pathogenesis associated with TET2 loss in CHIP is less understood. Here we review the recent development in TET2 biology and its probable mechanistic link in CH with aging and inflammation. We also explored the therapeutic strategies of targeting TET2MT associated CHIP and the utility of targeting TET2 in normal hematopoiesis and somatic cell reprograming. We explore the biochemical mechanisms and candidate therapies that emerged in last decade of research.

Reversal of cholestatic liver disease by the inhibition of sphingosine 1-phosphate receptor 2 signaling

Aims

The objective of this study is to examine the impact of inhibiting Sphingosine 1-phosphate receptor 2 (S1PR2) on liver inflammation, fibrogenesis, and changes of gut microbiome in the context of cholestasis-induced conditions.

Methods

The cholestatic liver injury model was developed by common bile duct ligation (CBDL). Sprague-Dawley rats were randomly allocated to three groups, sham operation, CBDL group and JTE-013 treated CBDL group. Biochemical and histological assessments were conducted to investigate the influence of S1PR2 on the modulation of fibrogenic factors and inflammatory infiltration. We conducted an analysis of the fecal microbiome by using 16S rRNA sequencing. Serum bile acid composition was evaluated through the utilization of liquid chromatography-mass spectrometry techniques.

Results

In the BDL rat model, the study findings revealed a significant increase in serum levels of conjugated bile acids, accompanied by an overexpression of S1PR2. Treatment with the specific inhibitor of S1PR2, known as JTE-013, resulted in a range of specific effects on the BDL rats. These effects included the improvement of liver function, reduction of liver inflammation, inhibition of hepatocyte apoptosis, and suppression of NETosis. These effects are likely mediated through the TCA/S1PR2/NOX2/NLRP3 pathway. Furthermore, the administration of JTE-013 resulted in an augmentation of the diversity of the bacterial community's diversity, facilitating the proliferation of advantageous species while concurrently inhibiting the prevalence of detrimental bacteria.

Conclusions

The results of our study suggest that the administration of JTE-013 may have a beneficial effect in alleviating cholestatic liver disease and restoring the balance of intestinal flora.

Lagopsis supina ameliorates myocardial ischemia injury by regulating angiogenesis, thrombosis, inflammation, and energy metabolism through VEGF, ROS and HMGB1 signaling pathways in rats

BACKGROUND

Lagopsis supina (Steph. ex. Willd.) Ikonn.-Gal. is an important traditional Chinese medicine used to treat various ailments. However, its impact on myocardial ischemia (MI) injury remains unknown.

PURPOSE

This research aimed to reveal the therapeutic effect, potential mechanism, and metabolomics of L. supina against MI injury in rats.

METHODS

The therapeutic effects of the ethanolic extract of L. supina (LS) and its four fractions (LSA∼D) on a left anterior descending (LAD) artery occlusion-induced MI model rat were explored. The pharmacodynamics including myocardial infraction area, myocardial tissue pathology and apoptosis, and serum biochemical parameters (CK, CK-MB, CTn-T, SOD, ET-1, NO, eNOS, VEGF, TXB2, 6-keto-PGF1α, TNF-α, IL-6, and CRP) were evaluated. The 24 related protein expressions were detected using western blotting assay. Simultaneously, the qualitative and quantitative analyses of microporous adsorption resin with 30% (LSC) and 60% (LSD) aqueous ethanol fractions were performed using UHPLC-MS and HPLC. Moreover, the serum metabolomics analysis of rats was profiled using UHPLC-MS.

RESULTS

LS exerted remarkable alleviating effect on MI in rats. Importantly, LSC and LSD, two effective fractions of LS, significantly reduced myocardial infraction area, alleviated myocardial tissue pathology and apoptosis, regulated serum biochemical parameters. Furthermore, LSC and LSD markedly up-regulated the levels of VEGF-A, VEGFR-2, PKC, Bcl-2, Nrf2, HO-1, and thrombin, as well as prominently down-regulated the protein expression of Notch 1, p-PI3K, p-PI3K/PI3K, p-Akt, p-Akt/Akt, Bax, cleaved-caspase-3, cleaved-caspase-3/caspase-3, vWF, p-Erk, p-Erk/Erk, HMGB1, p-p38, p-p38/p38, p-p65, and p-p65/p65. A total of 26 candidate biomarkers were significantly regulated by LSC and LSD and they are mainly involved in amino acid metabolism, glycerophospholipid metabolism, and sphingolipid metabolism. Finally, phenylethanols and flavonoids may be major bio-constituents of LSC and LSD against MI.

CONCLUSIONS

This work, for the first time, demonstrated that L. supina had a significant therapeutic effect on MI in rats. Additionally, LSC and LSD, two bio-fractions from L. supina, exerted their potential to ameliorate MI injury by promoting angiogenesis, inhibiting thrombosis, blocking inflammation, and facilitating energy metabolism through promotion of VEGF pathway, as well as suppression of ROS and HMGB1 pathways in rats. These findings suggest that LSC and LSD hold promise as potential therapeutic agents for MI injury in clinical application.

Sphingosine-1-phosphate Treatment Improves Cryopreservation Efficiency in Human Mesenchymal Stem Cells

The actin cytoskeleton plays a crucial role not only in maintaining cell shape and viability but also in homing/engraftment properties of mesenchymal stem cells (MSCs), a valuable source of cell therapy. Therefore, during the cryopreservation process of MSCs, protecting the actin cytoskeleton from the freezing/thawing stress is critical in maintaining their functionality and therapeutic potential. In this study, the safety and cryoprotective potential of sphingosine-1-phosphate (S1P), which has a stabilizing effect on actin cytoskeleton, on dental pulp-derived MSCs (DP-MSCs) was investigated. Our results demonstrated that S1P treatment did not adversely affect viability and stemness of DP-MSCs. Furthermore, S1P pretreatment enhanced cell viability and proliferation properties of post-freeze/thaw DP-MSCs, protecting them against damage to the actin cytoskeleton and adhesion ability as well. These findings suggest that a new cryopreservation method using S1P pretreatment can enhance the overall quality of cryopreserved MSCs by stabilizing the actin cytoskeleton and making them more suitable for various applications in regenerative medicine and cell therapy.

Sphingolipid Levels and Signaling via Resveratrol and Antioxidant Actions in Cardiometabolic Risk and Disease

Resveratrol (RSV) is a phenolic compound with strong antioxidant activity, which is generally associated with the beneficial effects of wine on human health. All resveratrol-mediated benefits exerted on different systems and pathophysiological conditions are possible through resveratrol's interactions with different biological targets, along with its involvement in several key cellular pathways affecting cardiometabolic (CM) health. With regard to its role in oxidative stress, RSV exerts its antioxidant activity not only as a free radical scavenger but also by increasing the activity of antioxidant enzymes and regulating redox genes, nitric oxide bioavailability and mitochondrial function. Moreover, several studies have demonstrated that some RSV effects are mediated by changes in sphingolipids, a class of biolipids involved in a number of cellular functions (e.g., apoptosis, cell proliferation, oxidative stress and inflammation) that have attracted interest as emerging critical determinants of CM risk and disease. Accordingly, this review aimed to discuss the available data regarding the effects of RSV on sphingolipid metabolism and signaling in CM risk and disease, focusing on oxidative stress/inflammatory-related aspects, and the clinical implications of this relationship.

Sphingosine-1-Phosphate Signaling in Cardiovascular Diseases

Sphingosine-1-phosphate (S1P) is an important sphingolipid molecule involved in regulating cardiovascular functions in physiological and pathological conditions by binding and activating the three G protein-coupled receptors (S1PR1, S1PR2, and S1PR3) expressed in endothelial and smooth muscle cells, as well as cardiomyocytes and fibroblasts. It exerts its actions through various downstream signaling pathways mediating cell proliferation, migration, differentiation, and apoptosis. S1P is essential for the development of the cardiovascular system, and abnormal S1P content in the circulation is involved in the pathogenesis of cardiovascular disorders. This article reviews the effects of S1P on cardiovascular function and signaling mechanisms in different cell types in the heart and blood vessels under diseased conditions. Finally, we look forward to more clinical findings with approved S1PR modulators and the development of S1P-based therapies for cardiovascular diseases.

Sphingosine-1-phosphate receptor 2 plays a dual role depending on the stage of cell differentiation in renal epithelial cells

Epithelial renal cells have the ability to adopt different cellular phenotypes through epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET). These processes are increasingly recognized as important repair factors following acute renal tubular injury. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid with impact on proliferation, growth, migration, and differentiation which has significant implication in various diseases including cancer and kidney fibrosis. Here we demonstrated that S1P can exert by activating S1P receptor 2 (S1PR2) different functions depending on the stage of cell differentiation. We observed that the differences in the migratory profile of Madin-Darby canine kidney (MDCK) cells depend both on their stage of cell differentiation and the activity of S1PR2, a receptor that can either promote or inhibit the migratory process. Meanwhile in non-differentiated cells S1PR2 activation avoids migration, it is essential on fully differentiated cells. This is the first time that an antagonist effect of S1PR2 was reported for the same cell type. Moreover, in fully differentiated cells, S1PR2 activation is crucial for the progression of EMT - characterized by adherent junctions disassembly, β-catenin and SNAI2 nuclear translocation and vimentin expression- and depends on ERK 1/2 activation and nuclear translocation. These findings provide a new perspective about the different S1PR2 functions depending on the stage of cell differentiation that can be critical to the modulation of renal epithelial cell plasticity, potentially paving the way for innovative research with pathophysiologic relevance.

Clonorchis sinensis infection induces hepatobiliary injury via disturbing sphingolipid metabolism and activating sphingosine 1-phosphate receptor 2

Clonorchis sinensis (C. sinensis) infection induces severe hepatobiliary injuries, which can cause inflammation, periductal fibrosis, and even cholangiocarcinoma. Sphingolipid metabolic pathways responsible for the generation of sphingosine-1-phosphate (S1P) and its receptor S1P receptors (S1PRs) have been implicated in many liver-related diseases. However, the role of S1PRs in C. sinensis-mediated biliary epithelial cells (BECs) proliferation and hepatobiliary injury has not been elucidated. In the present study, we found that C. sinensis infection resulted in alteration of bioactive lipids and sphingolipid metabolic pathways in mice liver. Furthermore, S1PR2 was predominantly activated among these S1PRs in BECs both in vivo and in vitro. Using JTE-013, a specific antagonist of S1PR2, we found that the hepatobiliary pathological injuries, inflammation, bile duct hyperplasia, and periductal fibrosis can be significantly inhibited in C. sinensis-infected mice. In addition, both C. sinensis excretory-secretory products (CsESPs)- and S1P-induced activation of AKT and ERK1/2 were inhibited by JTE-013 in BECs. Therefore, the sphingolipid metabolism pathway and S1PR2 play an important role, and may serve as potential therapeutic targets in hepatobiliary injury caused by C. sinensis-infection.

Sphingosine-1-phosphate improves outcome of no-reflow acute myocardial infarction via sphingosine-1-phosphate receptor 1

AIMS

Therapeutic options targeting post-ischaemic cardiac remodelling are sparse. The bioactive sphingolipid sphingosine-1-phosphate (S1P) reduces ischaemia/reperfusion injury. However, its impact on post-ischaemic remodelling independently of its infarct size (IS)-reducing effect is yet unknown and was addressed in this study.

METHODS AND RESULTS

Acute myocardial infarction (AMI) in mice was induced by permanent ligation of the left anterior descending artery (LAD). C57Bl6 were treated with the S1P lyase inhibitor 4-deoxypyridoxine (DOP) starting 7 days prior to AMI to increase endogenous S1P concentrations. Cardiac function and myocardial healing were assessed by cardiovascular magnetic resonance imaging (cMRI), murine echocardiography, histomorphology, and gene expression analysis. DOP effects were investigated in cardiomyocyte-specific S1P receptor 1 deficient (S1PR1 Cardio Cre+) and Cre- control mice and S1P concentrations measured by LC-MS/MS. IS and cardiac function did not differ between control and DOP-treated groups on day one after LAD-ligation despite fourfold increase in plasma S1P. In contrast, cardiac function was clearly improved and myocardial scar size reduced, respectively, on Day 21 in DOP-treated mice. The latter also exhibited smaller cardiomyocyte size and reduced embryonic gene expression. The benefit of DOP treatment was abolished in S1PR1 Cardio Cre+.

CONCLUSIONS

S1P improves cardiac function and myocardial healing post AMI independently of initial infarct size and accomplishes this via the cardiomyocyte S1PR1. Hence, in addition to its beneficial effects on I/R injury, S1PR1 may be a promising target in post-infarction myocardial remodelling as adjunctive therapy to revascularization as well as in patients not eligible for standard interventional procedures.

Characterizing human mesenchymal stromal cells' immune-modulatory potency using targeted lipidomic profiling of sphingolipids

Cell therapies are expected to increase over the next decade owing to increasing demand for clinical applications. Mesenchymal stromal cells (MSCs) have been explored to treat a number of diseases, with some successes in early clinical trials. Despite early successes, poor MSC characterization results in lessened therapeutic capacity once in vivo. Here, we characterized MSCs derived from bone marrow (BM), adipose tissue and umbilical cord tissue for sphingolipids (SLs), a class of bioactive lipids, using liquid chromatography/tandem mass spectrometry. We found that ceramide levels differed based on the donor's sex in BM-MSCs. We detected fatty acyl chain variants in MSCs from all three sources. Linear discriminant analysis revealed that MSCs separated based on tissue source. Principal component analysis showed that interferon-γ-primed and unstimulated MSCs separated according to their SL signature. Lastly, we detected higher ceramide levels in low indoleamine 2,3-dioxygenase MSCs, indicating that sphingomyelinase or ceramidase enzymatic activity may be involved in their immune potency.

Emerging Trends in Mesenchymal Stem Cells Applications for Cardiac Regenerative Therapy: Current Status and Advances

Irreversible myocardium infarction is one of the leading causes of cardiovascular disease (CVD) related death and its quantum is expected to grow in coming years. Pharmacological intervention has been at the forefront to ameliorate injury-related morbidity and mortality. However, its outcomes are highly skewed. As an alternative, stem cell-based tissue engineering/regenerative medicine has been explored quite extensively to regenerate the damaged myocardium. The therapeutic modality that has been most widely studied both preclinically and clinically is based on adult multipotent mesenchymal stem cells (MSC) delivered to the injured heart. However, there is debate over the mechanistic therapeutic role of MSC in generating functional beating cardiomyocytes. This review intends to emphasize the role and use of MSC in cardiac regenerative therapy (CRT). We have elucidated in detail, the various aspects related to the history and progress of MSC use in cardiac tissue engineering and its multiple strategies to drive cardiomyogenesis. We have further discussed with a focus on the various therapeutic mechanism uncovered in recent times that has a significant role in ameliorating heart-related problems. We reviewed recent and advanced technologies using MSC to develop/create tissue construct for use in cardiac regenerative therapy. Finally, we have provided the latest update on the usage of MSC in clinical trials and discussed the outcome of such studies in realizing the full potential of MSC use in clinical management of cardiac injury as a cellular therapy module.

Pharmacological Approaches to Limit Ischemic and Reperfusion Injuries of the Heart. Analysis of Experimental and Clinical Data on P2Y12 Receptor Antagonists

High mortality among people with acute myocardial infarction is one of the most urgent problems of modern cardiology. And in recent years, much attention has been paid to the search for pharmacological approaches to prevent heart damage. In this review, we tried to analyze data on the effect of P2Y₁₂ receptor antagonists on the ischemia/reperfusion tolerance of the heart.

Ischemic and reperfusion injuries of the heart underlie the pathogenesis of acute myocardial infarction (AMI) and sudden cardiac death. The mortality rate is still high and is 5–7% in patients with ST-segment elevation myocardial infarction. The review is devoted to pharmacological approaches to limitation of ischemic and reperfusion injuries of the heart. The article analyzes experimental evidence and the clinical data on the effects of P2Y₁₂ receptor antagonists on the heart’s tolerance to ischemia/reperfusion in animals with coronary artery occlusion and reperfusion and also in patients with AMI. Chronic administration of ticagrelor prevented adverse remodeling of the heart. There is evidence that sphingosine-1-phosphate is the molecule that mediates the infarct-reducing effect of P2Y₁₂ receptor antagonists. It was discussed a role of adenosine in the cardioprotective effect of ticagrelor.

Role of Signaling Pathways during Cardiomyocyte Differentiation of Mesenchymal Stem Cells

Multipotent stem cells, including mesenchymal stem cells (MSCs), represent a promising source to be used by regenerative medicine. They are capable of performing myogenic, chondrogenic, osteogenic and adipogenic differentiation. Also, MSCs are characterized by the expression of multiple surface antigens, but none of them appears to be particularly expressed on MSCs. Moreover, the prospect of monitoring and controlling MSC differentiation is a scientifically crucial regulatory and clinical requirement. Different transcription factors and signaling pathways are involved in cardiomyocyte differentiation. Due to the paucity of studies exclusively focused on cardiomyocyte differentiation of MSCs, present study aims at describing the roles of various signaling pathways (FGF, TGF, Wnt, Notch, etc.) in cardiomyocytes differentiation of MSCs. Understanding the signaling pathways that control the commitment and differentiation of cardiomyocyte cells not only will expand our basic understanding of molecular mechanisms of heart development, but also will enable us to develop therapeutic means of intervention in cardiovascular diseases.

Hopes and Hurdles of Employing Mesenchymal Stromal Cells in the Treatment of Cardiac Fibrosis

Excessive cardiac fibrosis plays a crucial role in almost all types of heart disease. Generally, cardiac fibrosis is a scarring process triggered in response to stress, injury, or aging and is characterized by the accumulation of activated myofibroblasts that deposit high levels of extracellular matrix proteins in the myocardium. While it is beneficial for cardiac repair in the short term, it can also result in pathological remodeling, tissue stiffening, and cardiac dysfunction, contributing to the progression of heart failure, arrhythmia, and sudden cardiac death. Despite its high prevalence, there is a lack of effective and safe therapies that specifically target myofibroblasts to inhibit or even reverse pathological cardiac fibrosis. In the past few decades, cell therapy has been under continuous evaluation as a potential treatment strategy, and several studies have shown that transplantation of mesenchymal stromal cells (MSCs) can reduce cardiac fibrosis and improve heart function. Mechanistically, it is believed that the heart benefits from MSC therapy by stimulating innate anti-fibrotic and regenerative reactions. The mechanisms of action include paracrine signaling and cell-to-cell interactions. In this review, we provide an overview of the anti-fibrotic properties of MSCs and approaches to enhance them and discuss future directions of MSCs for the treatment of cardiac fibrosis.

Regenerative Medicine for the Treatment of Ischemic Heart Disease; Status and Future Perspectives

Cardiovascular disease is now the leading cause of adult death in the world. According to new estimates from the World Health Organization, myocardial infarction (MI) is responsible for four out of every five deaths due to cardiovascular disease. Conventional treatments of MI are taking aspirin and nitroglycerin as intermediate treatments and injecting antithrombotic agents within the first 3 h after MI. Coronary artery bypass grafting and percutaneous coronary intervention are the most common long term treatments. Since none of these interventions will fully regenerate the infarcted myocardium, there is value in pursuing more innovative therapeutic approaches. Regenerative medicine is an innovative interdisciplinary method for rebuilding, replacing, or repairing the missed part of different organs in the body, as similar as possible to the primary structure. In recent years, regenerative medicine has been widely utilized as a treatment for ischemic heart disease (one of the most fatal factors around the world) to repair the lost part of the heart by using stem cells. Here, the development of mesenchymal stem cells causes a breakthrough in the treatment of different cardiovascular diseases. They are easily obtainable from different sources, and expanded and enriched easily, with no need for immunosuppressing agents before transplantation, and fewer possibilities of genetic abnormality accompany them through multiple passages. The production of new cardiomyocytes can result from the transplantation of different types of stem cells. Accordingly, due to its remarkable benefits, stem cell therapy has received attention in recent years as it provides a drug-free and surgical treatment for patients and encourages a more safe and feasible cardiac repair. Although different clinical trials have reported on the promising benefits of stem cell therapy, there is still uncertainty about its mechanism of action. It is important to conduct different preclinical and clinical studies to explore the exact mechanism of action of the cells. After reviewing the pathophysiology of MI, this study addresses the role of tissue regeneration using various materials, including different types of stem cells. It proves some appropriate data about the importance of ethical problems, which leads to future perspectives on this scientific method.

Mesenchymal Stem Cells Therapies on Fibrotic Heart Diseases

Stem cell therapy is a promising alternative approach to heart diseases. The most prevalent source of multipotent stem cells, usually called somatic or adult stem cells (mesenchymal stromal/stem cells, MSCs) used in clinical trials is bone marrow (BM-MSCs), adipose tissue (AT-MSCs), umbilical cord (UC-MSCs) and placenta. Therapeutic use of MSCs in cardiovascular diseases is based on the benefits in reducing cardiac fibrosis and inflammation that compose the cardiac remodeling responsible for the maintenance of normal function, something which may end up causing progressive and irreversible dysfunction. Many factors lead to cardiac fibrosis and failure, and an effective therapy is lacking to reverse or attenuate this condition. Different approaches have been shown to be promising in surpassing the poor survival of transplanted cells in cardiac tissue to provide cardioprotection and prevent cardiac remodeling. This review includes the description of pre-clinical and clinical investigation of the therapeutic potential of MSCs in improving ventricular dysfunction consequent to diverse cardiac diseases.

ELABELA ameliorates hypoxic/ischemic-induced bone mesenchymal stem cell apoptosis via alleviation of mitochondrial dysfunction and activation of PI3K/AKT and ERK1/2 pathways

Background

Mesenchymal stem cells (MSCs) have exerted their brilliant potential to promote heart repair following myocardial infarction. However, low survival rate of MSCs after transplantation due to harsh conditions with hypoxic and ischemic stress limits their therapeutic efficiency in treating cardiac dysfunction. ELABELA (ELA) serves as a peptide hormone which has been proved to facilitate cell growth, survival, and pluripotency in human embryonic stem cells. Although ELA works as an endogenous ligand of a G protein-coupled receptor APJ (Apelin receptor, APLNR), whether APJ is an essential signal for the function of ELA remains elusive. The effect of ELA on apoptosis of MSCs is still vague.

Objective

We studied the role of ELABELA (ELA) treatment on the anti-apoptosis of MSCs in hypoxic/ischemic (H/I) conditions which mimic the impaired myocardial microenvironment and explored the possible mechanisms in vitro.

Methods

MSCs were obtained from donated rats weighing between 80~120 g. MSCs were exposed to serum-free and hypoxic (1% O₂) environments for 24 h, which mimics hypoxic/ischemic damage in vivo, using serum-containing normoxic conditions (20% O₂) as a negative control. MSCs that were exposed to H/I injury with ELA processing were treated by 5 μM of ELA. Cell viability and apoptosis of MSCs were evaluated by CCK8 and flow cytometry, respectively. Mitochondrial function of MSCs was also assessed according to mitochondrial membrane potential (MMP) and ATP content. The protein expression of key kinases of the PI3K/AKT and ERK1/2 signaling pathways involving t-AKT, p-AKT, t-ERK1/2, and p-ERK1/2, as well as apoptosis-related protein expression of Bcl-2, Bax, and cleaved Caspase 3, were monitored by Western blot.

Results

We found that ELA treatment of H/I-induced MSCs improved overall cell viability, enhanced Bcl/Bax expression, and decreased Caspase 3 activity. ELA inhibited H/I-induced mitochondrial dysfunction by increasing ATP concentration and suppressing the loss of mitochondrial transmembrane potential. However, this anti-apoptotic property of ELA was restrained in APJ-silenced MSCs. Additionally, ELA treatment induced the phosphorylation of AKT and ERK, while the blockade of PI3K/AKT and ERK1/2 pathways with respective inhibitors, LY294002 and U0126, suppressed the action of ELA.

Conclusion

ELA positively affected on the survival of MSCs and exhibited anti-apoptotic characteristics when exposed to hypoxic/ischemic condition in vitro. Also, the function of ELA was correlated with the APJ receptor, reduced mitochondrial damage, and activation of the PI3K/AKT and ERK1/2 signal axes.

The role of sphingosine 1-phosphate and its receptors in cardiovascular diseases

There are many different types of cardiovascular diseases, which impose a huge economic burden due to their extremely high mortality rates, so it is necessary to explore the underlying mechanisms to achieve better supportive and curative care outcomes. Sphingosine 1‐phosphate (S1P) is a bioactive lipid mediator with paracrine and autocrine activities that acts through its cell surface S1P receptors (S1PRs) and intracellular signals. In the circulatory system, S1P is indispensable for both normal and disease conditions; however, there are very different views on its diverse roles, and its specific relevance to cardiovascular pathogenesis remains elusive. Here, we review the synthesis, release and functions of S1P, specifically detail the roles of S1P and S1PRs in some common cardiovascular diseases, and then address several controversial points, finally, we focus on the development of S1P‐based therapeutic approaches in cardiovascular diseases, such as the selective S1PR1 modulator amiselimod (MT‐1303) and the non‐selective S1PR1 and S1PR3 agonist fingolimod, which may provide valuable insights into potential therapeutic strategies for cardiovascular diseases.

The role of molecular mechanism of Ten-Eleven Translocation2 (TET2) family proteins in pathogenesis of cardiovascular diseases (CVDs)

Cardiovascular disease (CVD) is one of the most common diseases worldwide. The underlying pathogenesis of the disease has not yet been determined, but many factors have been identified. Tet methylcytosine dioxygenase 2 (TET2) is one of the epigenetic factors involved in regulating many genes. Therefore, based on the studies shown, this factor plays an important role in preventing the occurrence of CVD. TET2 has been shown to increase angiogenesis by expressing Robo4. It also increases the activity of Matrix metalloproteinases (MMPs) and stimulates the secretion of Vascular endothelial growth factor angiogenesis. On the other hand, it has been shown that TET2 regulates the expression of several genes and the development of the heart during the embryonic period due to its oxygenating role. TET2 has been shown to regulates the expression of the genes such as Ying Yang1 (YY1), Sox9b, Inhbaa and many other genes that ultimately lead to the differentiation of cardiomyocytes. On the other hand, it has been shown that some Long non coding RNA and MicroRNAs reduce TET2 expression and CVD. Finally, it is concluded that inducing TET2 expression can be a good therapeutic strategy to prevent or improve CVD.

Novel Insights into the Role of HDL-Associated Sphingosine-1-Phosphate in Cardiometabolic Diseases

Sphingolipids are key signaling molecules involved in the regulation of cell physiology. These species are found in tissues and in circulation. Although they only constitute a small fraction in lipid composition of circulating lipoproteins, their concentration in plasma and distribution among plasma lipoproteins appears distorted under adverse cardiometabolic conditions such as diabetes mellitus. Sphingosine-1-phosphate (S1P), one of their main representatives, is involved in regulating cardiomyocyte homeostasis in different models of experimental cardiomyopathy. Cardiomyopathy is a common complication of diabetes mellitus and represents a main risk factor for heart failure. Notably, plasma concentration of S1P, particularly high-density lipoprotein (HDL)-bound S1P, may be decreased in patients with diabetes mellitus, and hence, inversely related to cardiac alterations. Despite this, little attention has been given to the circulating levels of either total S1P or HDL-bound S1P as potential biomarkers of diabetic cardiomyopathy. Thus, this review will focus on the potential role of HDL-bound S1P as a circulating biomarker in the diagnosis of main cardiometabolic complications frequently associated with systemic metabolic syndromes with impaired insulin signaling. Given the bioactive nature of these molecules, we also evaluated its potential of HDL-bound S1P-raising strategies for the treatment of cardiometabolic disease.

Anti-fibrotic mechanisms of exogenously-expanded mesenchymal stromal cells for fibrotic diseases

Most chronic diseases involving inflammation have a fibrotic component that involves remodeling and excess accumulation of extracellular matrix components. Left unchecked, fibrosis leads to organ failure and death. Mesenchymal stromal cells (MSCs) are emerging as a potent cell-based therapy for a wide spectrum of fibrotic conditions due to their immunomodulatory, anti-inflammatory and anti-fibrotic properties. This review provides an overview of known mechanisms by which MSCs mediate their anti-fibrotic actions and in relation to animal models of pulmonary, liver, renal and cardiac fibrosis. Recent MSC clinical trials results in liver, lung, skin, kidney and hearts are discussed and next steps for future MSC-based therapies including pre-activated or genetically-modified cells, or extracellular vesicles are also considered.

Lipid mediators of insulin signaling in diabetic kidney disease

Diabetic kidney disease (DKD) affects ∼40% of patients with diabetes and is associated with high mortality rates. Among different cellular targets in DKD, podocytes, highly specialized epithelial cells of the glomerular filtration barrier, are injured in the early stages of DKD. Both clinical and experimental data support the role of preserved insulin signaling as a major contributor to podocyte function and survival. However, little is known about the key modulators of podocyte insulin signaling. This review summarizes the novel knowledge that intracellular lipids such as cholesterol and sphingolipids are major determinants of podocyte insulin signaling. In particular, the implications of these lipids on DKD development, progression, and treatment will be addressed.

Haemin pre-treatment augments the cardiac protection of mesenchymal stem cells by inhibiting mitochondrial fission and improving survival

The cardiac protection of mesenchymal stem cell (MSC) transplantation for myocardial infarction (MI) is largely hampered by low cell survival. Haem oxygenase 1 (HO‐1) plays a critical role in regulation of cell survival under many stress conditions. This study aimed to investigate whether pre‐treatment with haemin, a potent HO‐1 inducer, would promote the survival of MSCs under serum deprivation and hypoxia (SD/H) and enhance the cardioprotective effects of MSCs in MI. Bone marrow (BM)‐MSCs were pretreated with or without haemin and then exposed to SD/H. The mitochondrial morphology of MSCs was determined by MitoTracker staining. BM‐MSCs and haemin‐pretreated BM‐MSCs were transplanted into the peri‐infarct region in MI mice. SD/H induced mitochondrial fragmentation, as shown by increased mitochondrial fission and apoptosis of BM‐MSCs. Pre‐treatment with haemin greatly inhibited SD/H‐induced mitochondrial fragmentation and apoptosis of BM‐MSCs. These effects were partially abrogated by knocking down HO‐1. At 4 weeks after transplantation, compared with BM‐MSCs, haemin‐pretreated BM‐MSCs had greatly improved the heart function of mice with MI. These cardioprotective effects were associated with increased cell survival, decreased cardiomyocytes apoptosis and enhanced angiogenesis. Collectively, our study identifies haemin as a regulator of MSC survival and suggests a novel strategy for improving MSC‐based therapy for MI.

Mitomycin C modulates intracellular matrix metalloproteinase-9 expression and affects corneal fibroblast migration

Mitomycin C (MMC) is often used to prevent postoperative corneal haze and subconjunctival fibrosis in ocular surgery. It also affects the motility and viability of the residual ocular cells, including corneal stromal cells. Extracellular matrix metalloproteinase-9 (MMP-9) contributes to the promotion of cell movement in macrophage and cancer cells, but the intracellular role of MMP-9 remained unclear. Herein, we illustrated the novel role of intracellular MMP-9 in MMC-suppressed cell migration using isolated human corneal fibroblasts (HCFs). In HCFs, MMC enhanced intracellular MMP-9 at transcriptional and protein levels. Using co-immunoprecipitation analysis, we confirmed that MMC enhanced the association between intracellular MMP-9 and inactive FAK/paxillin (PXN) complexes, i.e. PXN without phospho-tyrosine 118 (pY118) and FAK without phospho-tyrosine 397 (pY397). To verify the role of intracellular MMP-9 in migration, its gene was directly isolated from HCFs and highly expressed in HCFs by a lentivirus-based pseudovirus system with encephalomyocarditis virus (EMCV)-driven enhanced green fluorescent protein (GFP) as the MMP-9-IG-versus IG-expressing cells. Compared with the IG-expressing cells, higher intracellular MMP-9 expression in the MMP-9-IG-expressing HCFs proliferated and migrated more slowly. Phosphorylation of FAK at Y397 and PXN at both Y31 and Y118 were significantly less in the MMP-9-IG-expressing HCFs. These suggested that MMC-upregulated intracellular MMP-9 clutched inactive FAK/PXN complexes at focal adhesion sites to form a new "inactive" trimer, prohibited FAK/PXN complexes phosphorylation and retarded corneal fibroblast migration.

The Antithrombotic Function of Sphingosine-1-Phosphate on Human Adipose-Stem-Cell-Recellularized Tissue Engineered Vascular Graft In Vitro

Adipose stem cells (ASCs) show potential in the recellularization of tissue engineerined vascular grafts (TEVGs). However, whether sphingosine-1-phosphate (S1P) could further enhance the adhesion, proliferation, and antithrombosis of ASCs on decellularized vascular scaffolds is unknown. This study investigated the effect of S1P on the recellularization of TEVGs with ASCs. Human ASCs were derived from lipoaspirate. Scaffolds were derived from human umbilical arteries (HUAs) with treatment of 0.1% sodium dodecyl sulfate (SDS) for 48 h (decellularized HUAs; DHUAs). The adhesion, proliferation, and antithrombotic functions (kinetic clotting time and platelet adhesion) of ASCs on DHUAs with S1P or without S1P were evaluated. The histology and DNA examination revealed a preserved structure and the elimination of the nuclear component more than 95% in HUAs after decellularizaiton. Human ASCs (hASCs) showed CD29(+), CD73(+), CD90(+), CD105(+), CD31(-), CD34(-), CD44(-), HLA-DR(-), and CD146(-) while S1P-treated ASCs showed marker shifting to CD31(+). In contrast to human umbilical vein endothelial cells (HUVECs), S1P didn't significantly increase proliferation of ASCs on DHUAs. However, the kinetic clotting test revealed prolonged blood clotting in S1P-treated ASC-recellularized DHUAs. S1P also decreased platelet adhesion on ASC-recellularized DHUAs. In addition, S1P treatment increased the syndecan-1 expression of ASCs. TEVG reconstituted with S1P and ASC-recellularized DHUAs showed an antithrombotic effect in vitro. The preliminary results showed that ASCs could adhere to DHUAs and S1P could increase the antithrombotic effect on ASC-recellularized DHUAs. The antithrombotic effect is related to ASCs exhibiting an endothelial-cell-like function and preventing of syndecan-1 shedding. A future animal study is warranted to prove this novel method.

Exosome Treatment Enhances Anti-Inflammatory M2 Macrophages and Reduces Inflammation-Induced Pyroptosis in Doxorubicin-Induced Cardiomyopathy

Doxorubicin (Dox) is an effective antineoplastic agent used to treat cancers, but its use is limited as Dox induces adverse cardiotoxic effects. Dox-induced cardiotoxicity (DIC) can lead to heart failure and death. There is no study that investigates whether embryonic stem cell-derived exosomes (ES-Exos) in DIC can attenuate inflammation-induced pyroptosis, pro-inflammatory M1 macrophages, inflammatory cell signaling, and adverse cardiac remodeling. For this purpose, we transplanted ES-Exos and compared with ES-cells (ESCs) to examine pyroptosis, inflammation, cell signaling, adverse cardiac remodeling, and their influence on DIC induced cardiac dysfunction. Therefore, we used C57BL/6J mice ages 10 ± 2 weeks and divided them into four groups (n = 6–8/group): Control, Dox, Dox + ESCs, and Dox + ES-Exos. Our data shows that the Dox treatment significantly increased expression of inflammasome markers (TLR4 and NLRP3), pyroptotic markers (caspase-1, IL1-β, and IL-18), cell signaling proteins (MyD88, p-P38, and p-JNK), pro-inflammatory M1 macrophages, and TNF-α cytokine. This increased pyroptosis, inflammation, and cell signaling proteins were inhibited with ES-Exos or ESCs. Moreover, ES-Exos or ESCs increased M2 macrophages and anti-inflammatory cytokine, IL-10. Additionally, ES-Exos or ESCs treatment inhibited significantly cytoplasmic vacuolization, myofibril loss, hypertrophy, and improved heart function. In conclusion, for the first time we demonstrated that Dox-induced pyroptosis and cardiac remodeling are ameliorated by ES-Exos or ESCs.

Network Pharmacology-Based Prediction and Verification of the Targets and Mechanism for Panax Notoginseng Saponins against Coronary Heart Disease

Coronary heart disease (CHD) is the worldwide leading cause for cardiovascular death. Panax notoginseng saponin (PNS), which is the main bioactive compound of panax notoginseng, has been generally accepted to exert a remarkable effect on CHD for a long time. However, to reveal the underlying treatment target and corresponding mechanism of PNS against CHD is still a substantial challenge. In this work, the targets and mechanism of PNS against CHD were successfully achieved by pharmacology-based prediction and experimental verification. 36 common targets were screened out through integrating the gene expression profile of CHD and the chemical-protein data of PNS. Then, two key nodes were further selected for verification by experiment after analyzing GO function, KEGG pathway, coexpression, and topology analysis. Results showed that PNS has protected the human umbilical vein endothelial cells from H₂O₂-induced oxidative stress by inhibiting early cell apoptosis via upregulating VEGFA mRNA expression. Therefore, our research has successfully pointed out one treatment target and apoptotic inhibition caused by PNS with method of integrating bioinformatics prediction and experimental verification, which has partially explained the pharmacological mechanism of PNS against CHD.

Dual Effects of Chinese Herbal Medicines on Angiogenesis in Cancer and Ischemic Stroke Treatments: Role of HIF-1 Network

Hypoxia-inducible factor-1 (HIF-1)–induced angiogenesis has been involved in numerous pathological conditions, and it may be harmful or beneficial depending on the types of diseases. Exploration on angiogenesis has sparked hopes in providing novel therapeutic approaches on multiple diseases with high mortality rates, such as cancer and ischemic stroke. The HIF-1 pathway is considered to be a major regulator of angiogenesis. HIF-1 seems to be involved in the vascular formation process by synergistic correlations with other proangiogenic factors in cancer and cerebrovascular disease. The regulation of HIF-1–dependent angiogenesis is related to the modulation of HIF-1 bioactivity by regulating HIF-1α transcription or protein translation, HIF-1α DNA binding, HIF-1α and HIF-1α dimerization, and HIF-1 degradation. Traditional Chinese herbal medicines have a long history of clinical use in both cancer and stroke treatments in Asia. Growing evidence has demonstrated potential proangiogenic benefits of Chinese herbal medicines in ischemic stroke, whereas tumor angiogenesis could be inhibited by the active components in Chinese herbal medicines. The objective of this review is to provide comprehensive insight on the effects of Chinese herbal medicines on angiogenesis by regulating HIF-1 pathways in both cancer and ischemic stroke.

Mesenchymal Stromal Cell Homing: Mechanisms and Strategies for Improvement

Mesenchymal stromal cells (MSCs) have been widely investigated for their therapeutic potential in regenerative medicine, owing to their ability to home damaged tissue and serve as a reservoir of growth factors and regenerative molecules. As such, clinical applications of MSCs are reliant on these cells successfully migrating to the desired tissue following their administration. Unfortunately, MSC homing is inefficient, with only a small percentage of cells reaching the target tissue following systemic administration. This attrition represents a major bottleneck in realizing the full therapeutic potential of MSC-based therapies. Accordingly, a variety of strategies have been employed in the hope of improving this process. Here, we review the molecular mechanisms underlying MSC homing, based on a multistep model involving (1) initial tethering by selectins, (2) activation by cytokines, (3) arrest by integrins, (4) diapedesis or transmigration using matrix remodelers, and (5) extravascular migration toward chemokine gradients. We then review the various strategies that have been investigated for improving MSC homing, including genetic modification, cell surface engineering, in vitro priming of MSCs, and in particular, ultrasound techniques, which have recently gained significant interest. Contextualizing these strategies within the multistep homing model emphasizes that our ability to optimize this process hinges on our understanding of its molecular mechanisms. Moving forward, it is only with a combined effort of basic biology and translational work that the potential of MSC-based therapies can be realized.