Resveratrol activates endogenous cardiac stem cells and improves myocardial regeneration following acute myocardial infarction

Natural small molecules synergize mesenchymal stem cells for injury repair in vital organs: a comprehensive review

Mesenchymal stem cells (MSCs) therapy is a highly researched treatment that has the potential to promote immunomodulation and anti-inflammatory, anti-apoptotic, and antimicrobial activities. It is thought that it can enhance internal organ function, reverse tissue remodeling, and achieve significant organ repair and regeneration. However, the limited infusion, survival, and engraftment of transplanted MSCs diminish the effectiveness of MSCs-based therapy. Consequently, various preconditioning methods have emerged as strategies for enhancing the therapeutic effects of MSCs and achieving better clinical outcomes. In particular, the use of natural small molecule compounds (NSMs) as a pretreatment strategy is discussed in this narrative review, with a focus on their roles in regulating MSCs for injury repair in vital internal organs. Additionally, the discussion focuses on the future directions and challenges of transforming mesenchymal stem cell research into clinical applications.

Effects of resveratrol on HIF-1α/VEGF pathway and apoptosis in vitrified duck ovary transplantation

Preservation of ovarian tissues is an effective way to ensure genetic diversity of susceptible natural bird populations that are in danger of extinction. We examined whether the addition of the plant phenol resveratrol to vitrification solutions ameliorates the damaging effects of tissue hypoxia and reperfusion injury when the tissues are transplanted. Duck ovary tissues were frozen in the presence of varying concentrations of resveratrol in cryopreservation solutions and then transplanted under the renal capsules of 2-day-old Shelducks. Samples of the transplanted tissues were examined on days 3- and 9- post transplantation for activation of hypoxia-, antioxidant- and apoptosis-related gene expression and apoptosis. Resveratrol significantly increased expression of VEGF, HIF-1α, Nrf2, CAT and Bcl-2 mRNA and decreased BAX and Caspase-3 mRNA and reduced numbers of TUNEL-positive cells after vitrification and heterotopic ovarian transplantation. Resveratrol improved the antioxidant capacity, reduced apoptosis and activated the HIF-1α/VEGF pathway to promote angiogenesis 3- and 9-days following transplantation. These results indicated that the addition of resveratrol to vitrification solutions intended for long-term cryopreservation of ovary tissues improves survival in storage and the grafts following transplantation. This study provides a theoretical basis for the successful transplantation of avian ovarian tissue after vitrification.

The Transport and Uptake of Resveratrol Mediated via Glucose Transporter 1 and Its Antioxidant Effect in Caco-2 Cells

Resveratrol has anti-inflammatory, anti-cancer, and anti-aging pharmacological activities. There is currently a gap in academic research regarding the uptake, transport, and reduction of H₂O₂-induced oxidative damage of resveratrol in the Caco-2 cell model. This study investigated the role of resveratrol in the uptake, transport, and alleviation of H₂O₂-induced oxidative damage in Caco-2 cells. In the Caco-2 cell transport model, it was observed that the uptake and transport of resveratrol (10, 20, 40, and 80 μM) were time dependent and concentration dependent. Different temperatures (37 °C vs. 4 °C) could significantly affect the uptake and transportation of resveratrol. The apical to basolateral transport of resveratrol was markedly reduced by STF-31, a GLUT1 inhibitor, and siRNA intervention. Furthermore, resveratrol pretreatment (80 μM) improves the viability of Caco-2 cells induced by H₂O₂. In a cellular metabolite analysis combined with ultra-high performance liquid chromatography-tandem mass spectrometry, 21 metabolites were identified as differentials. These differential metabolites belong to the urea cycle, arginine and proline metabolism, glycine and serine metabolism, ammonia recycling, aspartate metabolism, glutathione metabolism, and other metabolic pathways. The transport, uptake, and metabolism of resveratrol suggest that oral resveratrol could prevent intestinal diseases caused by oxidative stress.

Novel insights into the angiogenic function of JMJD2B in diabetic hind limb ischemia: involvement of activating Wnt/β-catenin pathway

Critical limb ischemia (CLI) is a major health problem, in which diabetes is a risk factor. Lysine Demethylase 4B (JMJD2B) is a histone demethylase. Diabetic CLI model was established in mice by streptozotocin injection and femoral artery ligation. Reduced expression of JMJD2B in lower limb muscles was observed in CLI mice with or without diabetes, accompanied by impaired blood perfusion and mobility. Adenovirus-mediated JMJD2B overexpression improved blood perfusion and angiogenesis as indicated by the alternation in CD31, α-SMA, and VEGFA expression in the lower limb of diabetic mice with CLI. In vitro, JMJD2B expression and the proliferation and tube formation ability were inhibited by high glucose and ischemic conditions in HMEC-1 cells. Overexpressed-JMJD2B contributed to angiogenesis by promoting cell proliferation, migration, and tube formation of HMEC-1 cells, as well as increasing VEGFA and SDF-1 expression. Mechanism study indicated that JMJD2B overexpression activated the Wnt/β-catenin pathway by promoting β-catenin nuclear translocation and the expression. This might lead to stimulated angiogenesis, as demonstrated by the Wnt/β-catenin inhibitor XAV-939. Overall, our study revealed that JMJD2B was down-regulated in CLI mice with diabetes and JMJD2B overexpression promoted angiogenesis probably via the activation of Wnt/β-catenin pathway.

Ursolic Acid Ameliorates the Injury of H9c2 Cells Caused by Hypoxia and Reoxygenation Through Mediating CXCL2/NF-κB Pathway

Ursolic acid (UA) has been reported to possess several biological benefits, such as anti-cancer, anti-inflammation, antibacterial, and neuroprotective functions. This study detects the function and molecular mechanism of UA in H9c2 cells under hypoxia and reoxygenation (H/R) conditions.Under H/R stimulation, the effects of UA on H9c2 cells were examined using ELISA and western blot assays. The Comparative Toxicogenomics Database was employed to analyze the target molecule of UA. Small interfering RNA was used to knock down CXCL2 expression, further exploring the function of CXCL2 in H/R-induced H9c2 cells. The genes related to the nuclear factor-kappa B (NF-κB) pathway were assessed using western blot analysis.Significant effects of UA on H/R-induced H9c2 cell damage were observed, accompanied by reduced inflammation and oxidative stress injury. Additionally, the increased level of CXCL2 in H/R-induced H9c2 cells was reduced after UA stimulation. Moreover, CXCL2 knockdown strengthened the beneficial effect of UA on H/R-induced H9c2 cells. HY-18739, an activator of the NF-κB pathway, can increase CXCL2 expression. Moreover, the increased levels of p-P65 NF-κB and p-IκBα in H/R-induced H9c2 cells were remarkably attenuated by UA treatment.In summary, the results indicated that UA may alleviate the damage of H9c2 cells by targeting the CXCL2/NF-κB pathway under H/R conditions.

Microbial dynamics in industrial-scale wine fermentation employing Hanseniaspora uvarum β-glucosidase-producer strain

The use of non-Saccharomyces yeast strains in winemaking is becoming a common trend. In fact, consumers are demanding new and healthier styles of wine. On the other hand, these strains are a challenge for the starting process due to winery-resident strains, especially with regard to industrial-scale fermentations. Current assay focuses on the scale-up of the laboratorial inoculum inside the winery environment to ferment 15,000 and 25,000 L of Vitis labrusca Bordô must, using a Hanseniaspora uvarum β-glucosidase-producer strain as starter culture. This scale-up could confirm the viability of using non-Saccharomyces yeast, as it presented promising results on a laboratory scale. The non-Saccharomyces strain was selected in a previous study since it proved to increase resveratrol concentration in lab scale winemaking. The yeast diversity was followed by the plate culturing method. Species identification and strain typing were determined by ITS-RFLP and PCR-fingerprinting, respectively. Physical and chemical analyses and resveratrol quantification were performed in the elaborated wines.

Notoginsenoside R1 relieves the myocardial infarction via activating the JAK2/STAT3 signaling pathway in vivo and in vitro

Myocardial infarction (MI), caused by continuous ischemia and hypoxia of the coronary artery, is one of the major causes of human mortality. This study aimed to investigate the role of notoginsenoside R1 (NGR1) in MI therapy. In vitro and in vivo models of MI were established by hypoxia/reoxygenation (H/R)-treatment of H9C2 cells and through the ligation of the left anterior descending coronary artery of rats, respectively. CCK-8 and EdU assays were performed to measure cell viability and proliferation, respectively. Flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were performed to determine the apoptotic rate of cells. Western blot was used to determine protein expression. The MI area was analyzed by 2,3,5-triphenyltetrazolium chloride (TTC) staining. NGR1 promoted viability and proliferation, and inhibited the apoptotic rate of H/R-treated H9C2 cells. In addition, NGR1 downregulated the protein expression of caspase-3 and Bax, and upregulated Bcl-2 expression in H/R-treated H9C2 cells. The JAK2/STAT3 signaling pathway was activated following NGR1 treatment in vivo and in vitro, and inhibition of the JAK2/STAT3 signaling pathway reversed the effects of NGR1 on H/R-treated H9C2 cells. Finally, NGR1 reduced the area of MI. NGR1 relieved MI in vivo and in vitro by activating the JAK2/STAT3 signaling pathway.

Potential of natural products in the treatment of myocardial infarction: focus on molecular mechanisms

Although conventional drugs are widely used in the prevention and treatment of cardiovascular disease (CVD), they are being used less frequently due to concerns about possible side effects over the long term. There has been a renewed research interest in medicinal plant products, and their role in protecting the cardiovascular system and treating CVD, which are now being considered as potential alternatives to modern drugs. The most important mechanism causing damage to the myocardium after heart attack and reperfusion, is increased levels of free radicals and oxidative stress. Therefore, treatment approaches often focus on reducing free radicals or enhancing antioxidant defense mechanism. It has been previously reported that bioactive natural products can protect the heart muscle in myocardial infarction (MI). Since these compounds are readily available in fruits and vegetables, they could prevent the risk of MI if they are consumed daily. Although the benefits of a healthy diet are well known, many scientific studies have focused on whether pure natural compounds can prevent and treat MI. In this review we summarize the effects of curcumin, resveratrol, quercitin, berberine, and tanshinone on MI and CVD, and focus on their proposed molecular mechanisms of action.

A Comprehensive Analysis of the Efficacy of Resveratrol in Atherosclerotic Cardiovascular Disease, Myocardial Infarction and Heart Failure

Atherosclerosis, myocardial infarction (MI) and heart failure (HF) are the main causes of mortality and morbidity around the globe. New therapies are needed to better manage ischemic heart disease and HF as existing strategies are not curative. Resveratrol is a stilbene polyphenolic compound with favorable biological effects that counter chronic diseases. Current evidence suggests that resveratrol is cardioprotective in animal models of atherosclerosis, ischemic heart disease, and HF. Though clinical studies for resveratrol have been promising, evidence remains inadequate to introduce it to the clinical setting. In this narrative review, we have comprehensively discussed the relevant compelling evidence regarding the efficacy of resveratrol as a new therapeutic agent for the management of atherosclerosis, MI and HF.

The roles of signaling pathways in cardiac regeneration

In recent years, knowledge of cardiac regeneration mechanisms has dramatically expanded. Regeneration can replace lost parts of organs, common among animal species. The heart is commonly considered an organ with terminal development, which has no reparability potential during post-natal life; however, some intrinsic regeneration capacity has been reported for cardiac muscle, which opens novel avenues in cardiovascular disease treatment. Different endogenous mechanisms were studied for cardiac repairing and regeneration in recent decades. Survival, proliferation, inflammation, angiogenesis, cell-cell communication, cardiomyogenesis, and anti-aging pathways are the most important mechanisms that have been studied in this regard. Several in vitro and animal model studies focused on proliferation induction for cardiac regeneration reported promising results. These studies have mainly focused on promoting proliferation signaling pathways and demonstrated various signaling pathways such as Wnt, PI3K/Akt, IGF-1, TGF-β, Hippo, and VEGF signaling cardiac regeneration. Therefore, in this review, we intended to discuss the connection between different critical signaling pathways in cardiac repair and regeneration.

The Potential Properties of Natural Compounds in Cardiac Stem Cell Activation: Their Role in Myocardial Regeneration

Cardiovascular diseases (CVDs), which include congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, and many other cardiac disorders, cause about 30% of deaths globally; representing one of the main health problems worldwide. Among CVDs, ischemic heart diseases (IHDs) are one of the major causes of morbidity and mortality in the world. The onset of IHDs is essentially due to an unbalance between the metabolic demands of the myocardium and its supply of oxygen and nutrients, coupled with a low regenerative capacity of the heart, which leads to great cardiomyocyte (CM) loss; promoting heart failure (HF) and myocardial infarction (MI). To date, the first strategy recommended to avoid IHDs is prevention in order to reduce the underlying risk factors. In the management of IHDs, traditional therapeutic options are widely used to improve symptoms, attenuate adverse cardiac remodeling, and reduce early mortality rate. However, there are no available treatments that aim to improve cardiac performance by replacing the irreversible damaged cardiomyocytes (CMs). Currently, heart transplantation is the only treatment being carried out for irreversibly damaged CMs. Hence, the discovery of new therapeutic options seems to be necessary. Interestingly, recent experimental evidence suggests that regenerative stem cell medicine could be a useful therapeutic approach to counteract cardiac damage and promote tissue regeneration. To this end, researchers are tasked with answering one main question: how can myocardial regeneration be stimulated? In this regard, natural compounds from plant extracts seem to play a particularly promising role. The present review will summarize the recent advances in our knowledge of stem cell therapy in the management of CVDs; focusing on the main properties and potential mechanisms of natural compounds in stimulating and activating stem cells for myocardial regeneration.

Stem Cell Metabolism: Powering Cell-Based Therapeutics

Cell-based therapeutics for cardiac repair have been extensively used during the last decade. Preclinical studies have demonstrated the effectiveness of adoptively transferred stem cells for enhancement of cardiac function. Nevertheless, several cell-based clinical trials have provided largely underwhelming outcomes. A major limitation is the lack of survival in the harsh cardiac milieu as only less than 1% donated cells survive. Recent efforts have focused on enhancing cell-based therapeutics and understanding the biology of stem cells and their response to environmental changes. Stem cell metabolism has recently emerged as a critical determinant of cellular processes and is uniquely adapted to support proliferation, stemness, and commitment. Metabolic signaling pathways are remarkably sensitive to different environmental signals with a profound effect on cell survival after adoptive transfer. Stem cells mainly generate energy through glycolysis while maintaining low oxidative phosphorylation (OxPhos), providing metabolites for biosynthesis of macromolecules. During commitment, there is a shift in cellular metabolism, which alters cell function. Reprogramming stem cell metabolism may represent an attractive strategy to enhance stem cell therapy for cardiac repair. This review summarizes the current literature on how metabolism drives stem cell function and how this knowledge can be applied to improve cell-based therapeutics for cardiac repair.

MicroRNA-363-3p serves as a diagnostic biomarker of acute myocardial infarction and regulates vascular endothelial injury by targeting KLF2

Background

Acute myocardial infarction (AMI) is a serious cardiovascular disease. This study aimed to investigate the diagnostic value of microRNA-363-3p (miR-363-3p) in AMI patients and explore the effects of miR-363-3p on vascular endothelial injury in an AMI rat model.

Methods

The Expression of miR-363-3p was measured by quantitative real-time PCR. A receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of miR-363-3p in AMI patients. The biomarkers of endothelial injury were estimated using enzyme-linked immunosorbent assays, and the correlation of miR-363-3p with these markers was assessed. AMI rat model was constructed using coronary artery ligation, and the effects of miR-363-3p on endothelial injury and endothelial cell proliferation were analyzed.

Results

Serum expression of miR-363-3p was upregulated in the AMI patients compared with healthy controls. The increased serum miR-363-3p serves a candidate diagnostic biomarker of AMI. The correlation analysis indicated that serum miR-363-3p expression was positively correlated with the concentration of endothelial injury biomarkers in AMI patients. Furthermore, the increased endothelial injury biomarkers in AMI rats were all inhibited by the knockdown of miR-363-3p, and the cell proliferation of human umbilical vein endothelial cells was obviously enhanced by the reduction of miR-363-3p. The prediction results shown that Kruppel-like factor 2 (KLF2) is a target of miR-363-3p, and their interaction was proved using a luciferase reporter assay.

Conclusions

Collectively, overexpression of miR-363-3p acts as a diagnostic biomarker for patients with AMI, and the downregulation of miR-363-3p improves AMI-associated endothelial injury by targeting KLF2, which indicated that miR-363-3p has a potential to develop the treatment of AMI.

Resveratrol inhibits adipocyte differentiation and cellular senescence of human bone marrow stromal stem cells

Bone marrow adipose tissue (BMAT) is a unique adipose depot originating from bone marrow stromal stem cells (BMSCs) and regulates bone homeostasis and energy metabolism. An increased BMAT volume is observed in several conditions e.g. obesity, type 2 diabetes, osteoporosis and is known to be associated with bone fragility and increased risk for fracture. Therapeutic approaches to decrease the accumulation of BMAT are clinically relevant. In a screening experiment of natural compounds, we identified Resveratrol (RSV), a plant-derived antioxidant mediating biological effects via sirtuin- related mechanisms, to exert significant effects of BMAT formation. Thus, we examined in details the effects RSV on adipocytic and osteoblastic differentiation of tolermerized human BMSCs (hBMSC-TERT). RSV (1.0 μM) enhanced osteoblastic differentiation and inhibited adipocytic differentiation of hBMSC-TERT when compared with control and Sirtinol (Sirtuin inhibitor). Global gene expression profiling and western blot analysis revealed activation of a number of signaling pathways including focal adhesion kinase (FAK). Pharmacological inhibition of FAK using (PF-573228) and AKT inhibitor (LY-294002) (5μM), diminished RSV-induced osteoblast differentiation. In addition, RSV reduced the levels of senescence-associated secretory phenotype (SASP), gene markers associated with senescence (P53, P16, and P21), intracellular ROS levels and increased gene expression of enzymes protecting cells from oxidative damage (HMOX1 and SOD3). In vitro treatment of primary hBMSCs from aged patients characterized with high adipocytic and low osteoblastic differentiation ability with RSV, significantly enhanced osteoblast and decreased adipocyte formation when compared to hBMSCs from young donors. RSV targets hBMSCs and inhibits adipogenic differentiation and senescence-associated phenotype and thus a potential agent for treating conditions of increased BMAT formation.

Collagen biomaterial for the treatment of myocardial infarction: an update on cardiac tissue engineering and myocardial regeneration

Myocardial infarction (MI) remains one of the leading cause of mortality over the world. However, current treatments are more palliative than curative, which only stall the progression of the disease, but not reverse the disease. While stem cells or bioactive molecules therapy is promising, the limited survival and engraftment of bioactive agent due to a hostile environment is a bottleneck for MI treatment. In order to maximize the utility of stem cells and bioactive molecules for myocardial repair and regeneration, various types of biomaterials have been developed. Among them, collagen-based biomaterial is widely utilized for cardiac tissue engineering and regeneration due to its optimal physical and chemical properties. In this review, we summarize the properties of collagen-based biomaterial. Then, we discuss collagen-based biomaterial currently being applied to treat MI alone, or together with stem cells and/or bioactive molecules. Finally, the delivery system of collagen-based biomaterial will also be discussed.

Changes of Metabolic Phenotype of Cardiac Progenitor Cells During Differentiation: Neutral Effect of Stimulation of AMP-Activated Protein Kinase

Cardiac progenitor cells (CPCs) in the adult mammalian heart, as well as exogenous CPCs injected at the border zone of infarcted tissue, display very low differentiation rate into cardiac myocytes and marginal repair capacity in the injured heart. Emerging evidence supports an obligatory metabolic shift from glycolysis to oxidative phosphorylation (OXPHOS) during stem cells differentiation, suggesting that pharmacological modulation of metabolism may improve CPC differentiation and, potentially, healing properties. In this study, we investigated the metabolic transition underlying CPC differentiation toward cardiac myocytes. In addition, we tested whether activators of adenosine monophosphate-activated protein kinase (AMPK), known to promote mitochondrial biogenesis in other cell types would also improve CPC differentiation. Stem cell antigen 1 (Sca1⁺) CPCs were isolated from adult mouse hearts and their phenotype compared with more mature neonatal rat cardiac myocytes (NRCMs). Under normoxia, glucose consumption and lactate release were significantly higher in CPCs than in NRCMs. Both parameters were increased in hypoxia together with increased abundance of Glut1 (glucose transporter), of the monocarboxylic transporter Mct4 (lactate efflux mediator) and of Pfkfb3 (key regulator of glycolytic rate). CPC proliferation was critically dependent on glucose and glutamine availability in the media. Oxygen consumption analysis indicates that, compared with NRCMs, CPCs exhibited lower basal and maximal respirations with lower Tomm20 protein expression and mitochondrial DNA content. This CPC metabolic phenotype profoundly changed upon in vitro differentiation, with a decrease of glucose consumption and lactate release together with increased abundance of Tnnt2, Pgc-1α, Tomm20, and mitochondrial DNA content. Proliferative CPCs express both alpha1 and -2 catalytic subunits of AMPK that is activated by A769662. However, A769662 or resveratrol (an activator of Pgc-1α and AMPK) did not promote either mitochondrial biogenesis or CPC maturation during their differentiation. We conclude that although CPC differentiation is accompanied with an increase of mitochondrial oxidative metabolism, this is not potentiated by activation of AMPK in these cells.

Resveratrol Activates Autophagy via the AKT/mTOR Signaling Pathway to Improve Cognitive Dysfunction in Rats With Chronic Cerebral Hypoperfusion

Chronic cerebral hypoperfusion (CCH) is a main cause of vascular dementia and is also an etiological factor of neurological diseases and mental disorders. However, few treatments are available for CCH, and new medications are needed. In the present study, we employed a rat model of CCH that was based on bilateral common carotid artery occlusion and investigated the therapeutic effects of resveratrol and its detailed mechanism of action. We evaluated neurological deficit scores and performed the Morris water maze test, hematoxylin and eosin staining, TUNEL staining, enzyme-linked immunosorbent assays, and Western blot. Resveratrol reduced neurological deficit scores in CCH rats and reduced pathological damage in the frontal cortex and hippocampus. Resveratrol activated autophagy and inhibited the expression of AKT/mechanistic target of rapamycin (mTOR) signaling pathway-related proteins. Treatment with a phosphoinositide-3 kinase inhibitor reversed the protective effect of resveratrol. These findings suggest that resveratrol improves cognitive function in a rat model of CCH and reduces oxidative stress-induced neuronal damage in the frontal cortex and hippocampus by activating autophagy and inhibiting neuronal apoptosis. These effects may be regulated by the AKT/mTOR signaling pathway.

Bone-derived Nestin-positive mesenchymal stem cells improve cardiac function via recruiting cardiac endothelial cells after myocardial infarction

BACKGROUND

Bone-derived mesenchymal stem cell (BMSC) transplantation has been reported to be effective for the treatment of ischemic heart disease, but whether BMSCs are the optimal cell type remains under debate. Increasing numbers of studies have shown that Nestin, an intermediate filament protein, is a potential marker for MSCs, which raises the question of whether Nestin⁺ cells in BMSCs may play a more crucial role in myocardial repair.

METHODS

Nestin⁺ cells were isolated using flow cytometry by gating for CD45^- Ter119^- CD31^- cells from the compact bone of Nestin-GFP transgenic mice, expressing GFP driven by the Nestin promoter. Colony-forming and proliferative curve assays were conducted to determine the proliferative capacity of these cells, while qRT-PCR was used to analyze the mRNA levels of relative chemokines and growth factors. Cardiac endothelial cell (CEC) recruitment was assessed via a transwell assay. Moreover, permanent ligation of the left anterior descending (LAD) coronary artery was performed to establish an acute myocardial infarction (AMI) mouse model. After cell transplantation, conventional echocardiography was conducted 1 and 4 weeks post-MI, and hearts were harvested for hematoxylin-and-eosin (HE) staining and immunofluorescence staining 1 week post-MI. Further evaluation of paracrine factor levels and administration of a neutralizing antibody (TIMP-1, TIMP-2, and CXCL12) or a CXCR4 antagonist (AMD3100) in MI hearts were performed to elucidate the mechanism involved in the chemotactic effect of Nestin⁺ BMSCs in vivo.

RESULTS

Compared with Nestin^- BMSCs, a greater proliferative capacity of Nestin⁺ BMSCs was observed, which further exhibited moderately high expression of chemokines instead of growth factors. More CEC recruitment in the Nestin⁺ BMSC-cocultured group was observed in vitro, while this effect was obviously abolished after treatment with neutralizing antibodies against TIMP-1, TIMP-2, or CXCL12, and more importantly, blocking the CXCL12/CXCR4 axis with a AMD3100 significantly reduced the chemotactic effect of Nestin⁺ BMSCs. After transplantation into mice exposed to myocardial infarction (MI), Nestin⁺ BMSC-treated mice showed significantly improved survival and left ventricular function compared with Nestin^- BMSC-treated mice. Moreover, endogenous CECs were markedly increased, and chemokine levels were significantly higher, in the infarcted border zone with Nestin⁺ BMSC treatment. Meanwhile, neutralization of each TIMP-1, TIMP-2, or CXCL12 in vivo could reduce the left ventricular function at 1 and 4 weeks post-MI; importantly, the combined use of these three neutralizing antibodies could make a higher significance on cardiac function. Finally, blocking the CXCL12/CXCR4 axis with AMD3100 significantly reduced the left ventricular function and greatly inhibited Nestin⁺ BMSC-induced CEC chemotaxis in vivo.

CONCLUSIONS

These results suggest that Nestin⁺ BMSC transplantation can improve cardiac function in an AMI model by recruiting resident CECs to the infarcted border region via the CXCL12/CXCR4 chemokine pathway. And we demonstrated that Nestin⁺BMSC-secreted TIMP-1/2 enhances CXCL12(SDF1α)/CXCR4 axis-driven migration of endogenous Sca-1⁺ endothelial cells in ischemic heart post-AMI. Taken together, our results show that Nestin is a useful marker for the identification of functional BMSCs and indicate that Nestin⁺ BMSCs could be a better therapeutic candidate for cardiac repair.

Potential Non-neoplastic Applications for Polyphenols in Stem Cell Utilization

While polyphenols may have important effects on pluripotential stem cells that make them noteworthy as potential antineoplastic agents, their action on stem cells may portend other health benefits, such as treatments for cardiovascular and neurocognitive disorders. Resveratrol, the beststudied polyphenol, has been found to enable stem cells to differentiate into cardiomyocytes, neurons, osteocytes, and pancreatic beta cells, as well as facilitating augmentation of stem cell populations and protecting them from toxic injury. Curcumin protects mesenchymal stem cells from toxicity, and prevents them from facilitating chondrocytic hypertrophy. Quercetin enabled osteocytic and pancreatic beta cell differentiation, and protected neuronal stem cells from injury. Epigallocatechin gallate prevented damage to osteocyte precursors and averted differentiation into undesirable adipocytes. Genistein facilitated osteogenesis while preventing adipogenesis. Several other polyphenols, daidzein, caffeic and chlorogenic acid, kaempferol, and piceatannol, protect stems cells from reactive oxygen species and foster stem cells differentiation away from adipocytic and toward osteocytic lineages. Further research should better elucidate the pharmacokinetic profiles of each polyphenol, explore novel delivery systems, and expand investigation beyond rodent models to additional species.

Resveratrol counteracts bone loss via mitofilin-mediated osteogenic improvement of mesenchymal stem cells in senescence-accelerated mice

Rational: Senescence of mesenchymal stem cells (MSCs) and the related functional decline of osteogenesis have emerged as the critical pathogenesis of osteoporosis in aging. Resveratrol (RESV), a small molecular compound that safely mimics the effects of dietary restriction, has been well documented to extend lifespan in lower organisms and improve health in aging rodents. However, whether RESV promotes function of senescent stem cells in alleviating age-related phenotypes remains largely unknown. Here, we intend to investigate whether RESV counteracts senescence-associated bone loss via osteogenic improvement of MSCs and the underlying mechanism.

Methods: MSCs derived from bone marrow (BMMSCs) and the bone-specific, senescence-accelerated, osteoblastogenesis/osteogenesis-defective mice (the SAMP6 strain) were used as experimental models. In vivo application of RESV was performed at 100 mg/kg intraperitoneally once every other day for 2 months, and in vitro application of RESV was performed at 10 μM. Bone mass, bone formation rates and osteogenic differentiation of BMMSCs were primarily evaluated. Metabolic statuses of BMMSCs and the mitochondrial activity, transcription and morphology were also examined. Mitofilin expression was assessed at both mRNA and protein levels, and short hairpin RNA (shRNA)-based gene knockdown was applied for mechanistic experiments.

Results: Chronic intermittent application of RESV enhances bone formation and counteracts accelerated bone loss, with RESV improving osteogenic differentiation of senescent BMMSCs. Furthermore, in rescuing osteogenic decline under BMMSC senescence, RESV restores cellular metabolism through mitochondrial functional recovery via facilitating mitochondrial autonomous gene transcription. Molecularly, in alleviating senescence-associated mitochondrial disorders of BMMSCs, particularly the mitochondrial morphological alterations, RESV upregulates Mitofilin, also known as inner membrane protein of mitochondria (Immt) or Mic60, which is the core component of the mitochondrial contact site and cristae organizing system (MICOS). Moreover, Mitofilin is revealed to be indispensable for mitochondrial homeostasis and osteogenesis of BMMSCs, and that insufficiency of Mitofilin leads to BMMSC senescence and bone loss. More importantly, Mitofilin mediates resveratrol-induced mitochondrial and osteogenic improvements of BMMSCs in senescence.

Conclusion: Our findings uncover osteogenic functional improvements of senescent MSCs as critical impacts in anti-osteoporotic practice of RESV, and unravel Mitofilin as a novel mechanism mediating RESV promotion on mitochondrial function in stem cell senescence.

The current status and future of cardiac stem/progenitor cell therapy for congenital heart defects from diabetic pregnancy

Pregestational maternal diabetes induces congenital heart defects (CHDs). Cardiac dysfunction after palliative surgical procedures contributes to the high mortality of CHD patients. Autologous or allogeneic stem cell therapies are effective for improving cardiac function in animal models and clinical trials. c-kit+ cardiac progenitor cells (CPCs), the most recognized CPCs, have the following basic properties of stem cells: self-renewal, multicellular clone formation, and differentiation into multiple cardiac lineages. However, there is ongoing debate regarding whether c-kit+ CPCs can give rise to sufficient cardiomyocytes. A new hypothesis to address the beneficial effect of c-kit+ CPCs is that these cells stimulate endogenous cardiac cells through a paracrine function in producing a robust secretome and exosomes. The values of other cardiac CPCs, including Sca1+ CPCs and cardiosphere-derived cells, are beginning to be revealed. These cells may be better choices than c-kit+ CPCs for generating cardiomyocytes. Adult mesenchymal stem cells are considered immune-incompetent and effective for improving cardiac function. Autologous CPC therapy may be limited by the observation that maternal diabetes adversely affects the biological function of embryonic stem cells and CPCs. Future studies should focus on determining the mechanistic action of these cells, identifying new CPC markers, selecting highly effective CPCs, and engineering cell-free products.

Resveratrol pretreatment enhanced homing of SDF-1α-preconditioned bone marrow-derived mesenchymal stem cells in a rat model of liver cirrhosis

Stromal cell-derived factor-1α (SDF-1α) has been known to implicate in homing of MSCs, and resveratrol has been reported to have a positive influence on SDF-1 level in the site of injury. In this study, a combined strategy was applied to evaluate bone marrow-derived MSCs (BMSCs) homing to the rat model of liver cirrhosis induced by common bile duct ligation (CBDL): (1) pretreatment delivery of resveratrol into the cirrhotic liver, and (2) transplantation of ex vivo BMSC preconditioning with SDF-1α. BMSCs were preconditioned with 10 ng/µL SDF-1α for 1 h and then labeled with the CM-Dil. Cirrhosis was induced by CBDL. Animals received intraperitoneal injection of resveratrol for 7 days, started on day 28 of CBDL post-operative. On day 36 post-operative, 1 × 10⁶ of SDF-1α-preconditioned BMSCs was injected via caudal vein. Animals were sacrificed at 72 h post-cell transplantation. Immunofluorescence and flow cytometry assessments showed that the BMSC+SDF+RV group had an increased rate of homing into the liver, but it had a decreased rate of homing into the lung and spleen, as compared with the other groups (P < 0.05). The BMSC+SDF+RV group showed high protein expression of SIRT1, but low protein expression of p53 in the liver (P < 0.05 vs other groups). CXCR4 and matrix metalloproteinase (MMP)-9 highly expressed in SDF-1α-preconditioned BMSCs in vitro, and that AKTs and CXCL12 expressed in injured liver undergoing resveratrol injection. Our findings suggest that reseveratrol pretreatment prior to SDF-1α preconditioning could be a promising strategy for designing cell-based therapies for liver cirrhosis.

Endothelial and cardiac progenitor cells for cardiovascular repair: A controversial paradigm in cell therapy

Stem cells have the potential to differentiate into cardiovascular cell lineages and to stimulate tissue regeneration in a paracrine/autocrine manner; thus, they have been extensively studied as candidate cell sources for cardiovascular regeneration. Several preclinical and clinical studies addressing the therapeutic potential of endothelial progenitor cells (EPCs) and cardiac progenitor cells (CPCs) in cardiovascular diseases have been performed. For instance, autologous EPC transplantation and EPC mobilization through pharmacological agents contributed to vascular repair and neovascularization in different animal models of limb ischemia and myocardial infarction. Also, CPC administration and in situ stimulation of resident CPCs have been shown to improve myocardial survival and function in experimental models of ischemic heart disease. However, clinical studies using EPC- and CPC-based therapeutic approaches have produced mixed results. In this regard, intracoronary, intra-myocardial or intramuscular injection of either bone marrow-derived or peripheral blood progenitor cells has improved pathological features of tissue ischemia in humans, despite modest or no clinical benefit has been observed in most cases. Also, the intriguing scientific background surrounding the potential clinical applications of EPC capture stenting is still waiting for a confirmatory proof. Moreover, clinical findings on the efficacy of CPC-based cell therapy in heart diseases are still very preliminary and based on small-size studies. Despite promising evidence, widespread clinical application of both EPCs and CPCs remains delayed due to several unresolved issues. The present review provides a summary of the different applications of EPCs and CPCs for cardiovascular cell therapy and underlies their advantages and limitations.