Regenerative medicine is the field concerned with the repair and restoration of the integrity of damaged human tissues as well as whole organs.Since the inception of the field several decades ago,regenerative medicine...Regenerative medicine is the field concerned with the repair and restoration of the integrity of damaged human tissues as well as whole organs.Since the inception of the field several decades ago,regenerative medicine therapies,namely stem cells,have received significant attention in preclinical studies and clinical trials.Apart from their known potential for differentiation into the various body cells,stem cells enhance the organ's intrinsic regenerative capacity by altering its environment,whether by exogenous injection or introducing their products that modulate endogenous stem cell function and fate for the sake of regeneration.Recently,research in cardiology has highlighted the evidence for the existence of cardiac stem and progenitor cells(CSCs/CPCs).The global burden of cardiovascular diseases’morbidity and mortality has demanded an in-depth understanding of the biology of CSCs/CPCs aiming at improving the outcome for an innovative therapeutic strategy.This review will discuss the nature of each of the CSCs/CPCs,their environment,their interplay with other cells,and their metabolism.In addition,important issues are tackled concerning the potency of CSCs/CPCs in relation to their secretome for mediating the ability to influence other cells.Moreover,the review will throw the light on the clinical trials and the preclinical studies using CSCs/CPCs and combined therapy for cardiac regeneration.Finally,the novel role of nanotechnology in cardiac regeneration will be explored.展开更多
The emergence of cardiac stem cell therapy can be traced to late 2001, when studies in small animal models of myocardial infarction suggested that stem cells could engraft, proliferate, and regenerate myo-cardium. Sub...The emergence of cardiac stem cell therapy can be traced to late 2001, when studies in small animal models of myocardial infarction suggested that stem cells could engraft, proliferate, and regenerate myo-cardium. Subsequent animal laboratory studies showed improved cardiac function, perfusion and survival compared to controls (Figure 1). Within two years, the first clinical trials of stem cell therapy began to appear, and we now have several trials of intracoronary infusion of bone marrow cells with more than one year follow-up. Although this clinical therapy has proven to be safe, the magnitude of improvement in objective measures like ejection fraction has been modest, and the therapy has not entered clinical practice. In the absence of a large prospective randomized trial, the field has moved back to the laboratory. This manuscript aims to provide clinicians with a broad overview of this complex field by briefly reviewing the existing status of clinical myocardial regeneration therapy, then describing selected examples from the laboratory research approaches that may provide a platform for new and potentially increasingly effective clinical strategies.展开更多
Cardiovascular diseases represent the world’s leading cause of death. In thisheterogeneous group of diseases, ischemic cardiomyopathies are the mostdevastating and prevalent, estimated to cause 17.9 million deaths pe...Cardiovascular diseases represent the world’s leading cause of death. In thisheterogeneous group of diseases, ischemic cardiomyopathies are the mostdevastating and prevalent, estimated to cause 17.9 million deaths per year.Despite all biomedical efforts, there are no effective treatments that can replacethe myocytes lost during an ischemic event or progression of the disease to heartfailure. In this context, cell therapy is an emerging therapeutic alternative to treatcardiovascular diseases by cell administration, aimed at cardiac regeneration andrepair. In this review, we will cover more than 30 years of cell therapy in cardiology,presenting the main milestones and drawbacks in the field and signalingfuture challenges and perspectives. The outcomes of cardiac cell therapies arediscussed in three distinct aspects: The search for remuscularization byreplacement of lost cells by exogenous adult cells, the endogenous stem cell era,which pursued the isolation of a progenitor with the ability to induce heart repair,and the utilization of pluripotent stem cells as a rich and reliable source ofcardiomyocytes. Acellular therapies using cell derivatives, such as microvesiclesand exosomes, are presented as a promising cell-free therapeutic alternative.展开更多
Hypoxia is beneficial for the differentiation of stem cells transplanted for myocardial injury,but mechanisms underlying this benefit remain unsolved. Here, we report the impact of hypoxia-induced Jagged1 expression i...Hypoxia is beneficial for the differentiation of stem cells transplanted for myocardial injury,but mechanisms underlying this benefit remain unsolved. Here, we report the impact of hypoxia-induced Jagged1 expression in cardiomyocytes(CMs) for driving the differentiation of cardiac stem cells(CSCs).Forced hypoxia-inducible factor 1α(HIF-1α) expression and physical hypoxia(5% O_2) treatment could induce Jagged1 expression in neonatal rat CMs. Pharmacological inhibition of HIF-1α by YC-1 attenuated hypoxia-promoted Jagged1 expression in CMs. An ERK inhibitor(PD98059), but not inhibitors of JNK(SP600125), Notch(DAPT), NF-κB(PTDC), JAK(AG490), or STAT3(Stattic) suppressed hypoxiainduced Jagged1 protein expression in CMs. c-Kit^+ CSCs isolated from neonatal rat hearts using a magnetic-activated cell sorting method expressed GATA4, SM22α or vWF, but not Nkx2.5 and cTnI.Moreover, 87.3% of freshly isolated CSCs displayed Notch1 receptor expression. Direct co-culture of CMs with BrdU-labeled CSCs enhanced CSCs differentiation, as evidenced by an increased number of BrdU^+/Nkx2.5^+ cells, while intermittent hypoxia for 21 days promoted co-culture-triggered differentiation of CSCs into CM-like cells. Notably, YC-1 and DAPT attenuated hypoxia-induced differentiation.Our results suggest that hypoxia induces Jagged1 expression in CMs primarily through ERK signaling,and facilitates early cardiac lineage differentiation of CSCs in CM/CSC co-cultures via HIF-1α/Jagged1/Notch signaling.展开更多
Over the last years, stem cell therapy has emerged asan inspiring alternative to restore cardiac function after myocardial infarction. A large body of evidence has been obtained in this field but there is no conclusiv...Over the last years, stem cell therapy has emerged asan inspiring alternative to restore cardiac function after myocardial infarction. A large body of evidence has been obtained in this field but there is no conclusive data on the efficacy of these treatments. Preclinical studies and early reports in humans have been encouraging and have fostered a rapid clinical translation, but positive results have not been uniformly observed and when present, they have been modest. Several types of stem cells, manufacturing methods and delivery routes have been tested in different clinical settings but direct comparison between them is challenging and hinders further research. Despite enormous achievements, major barriers have been found and many fundamental issues remain to be resolved. A better knowledge of the molecular mechanisms implicated in cardiac development and myocardial regeneration is critically needed to overcome some of these hurdles. Genetic and pharmacological priming together with the discovery of new sources of cells have led to a "second generation" of cell products that holds an encouraging promise in cardiovascular regenerative medicine. In this report, we review recent advances in this field focusing on the new types of stem cells that are currently being tested in human beings and on the novel strategies employed to boost cell performance in order to improve cardiac function and outcomes after myocardial infarction.展开更多
Causative mutations and variants associated with cardiac diseases have been found in genes encoding cardiac ion channels, accessory proteins, cytoskeletal components, junctional proteins, and signaling molecules. In m...Causative mutations and variants associated with cardiac diseases have been found in genes encoding cardiac ion channels, accessory proteins, cytoskeletal components, junctional proteins, and signaling molecules. In most cases the functional evaluation of the genetic alterationhas been carried out by expressing the mutated proteins in in-vitro heterologous systems. While these studies have provided a wealth of functional details that have greatly enhanced the understanding of the pathological mechanisms, it has always been clear that heterologous expression of the mutant protein bears the intrinsic limitation of the lack of a proper intracellular environment and the lack of pathological remodeling. The results obtained from the application of the next generation sequencing technique to patients suffering from cardiac diseases have identified several loci, mostly in non-coding DNA regions, which still await functional analysis. The isolation and culture of human embryonic stem cells has initially provided a constant source of cells from which cardiomyocytes(CMs) can be obtained by differentiation. Furthermore, the possibility to reprogram cellular fate to a pluripotent state, has opened this process to the study of genetic diseases. Thus induced pluripotent stem cells(i PSCs) represent a completely new cellular model that overcomes the limitations of heterologous studies. Importantly, due to the possibility to keep spontaneously beating CMs in culture for several months, during which they show a certain degree of maturation/aging, this approach will also provide a system in which to address the effect of long-term expression of the mutated proteins or any other DNA mutation, in terms of electrophysiological remodeling. Moreover, since i PSC preserve the entire patients' genetic context, the system will help the physicians in identifying the most appropriate pharmacological intervention to correct the functional alteration. This article summarizes the current knowledge of cardiac genetic diseases modelled with i PSC.展开更多
BACKGROUND： Numerous studies have shown that magnetic resonance imaging （MRI） can detect survival and migration of super paramagnetic iron oxide-labeled stem cells in models of focal cerebral infarction. OBJECTIVE...BACKGROUND： Numerous studies have shown that magnetic resonance imaging （MRI） can detect survival and migration of super paramagnetic iron oxide-labeled stem cells in models of focal cerebral infarction. OBJECTIVE： To observe distribution of bone marrow mesenchymal stem cells （BMSCs） in a rat model of global brain ischemia following cardiac arrest and resuscitation, and to investigate the feasibility of tracing iron oxide-labeled BMSCs using non-invasive MRI. DESIGN, TIME AND SETTING： The randomized, controlled, molecular imaging study was performed at the Linbaixin Medical Research Center, Second Affiliated Hospital, Sun Yat-sen University, and the Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, China from October 2006 to February 2009. MATERIALS： A total of 40 clean, Sprague Dawley rats, aged 6 weeks and of either gender, were supplied by the Experimental Animal Center, Sun Yat-sen University, China, for isolation of BMSCs. Feridex （iron oxide）, Gyroscan Inetra 1.5T MRI system, and cardiopulmonary resuscitation device were used in this study. METHODS： A total of 30 healthy, male Sprague Dawiey rats, aged 6 months, were used to induce ventricular fibrillation using alternating current. After 8 minutes, the rats underwent 6-minute chest compression and mechanical ventilation, followed by electric defibrillation, to establish rat models of global brain ischemia due to cardiac arrest and resuscitation. A total of 24 successful models were randomly assigned to Feridex-labeled and non-labeled groups （n = 12 for each group）. At 2 hours after resuscitation, 5 ×10^8 Feridex-labeled BMSCs, with protamine sulfate as a carrier, and 5 ×10^6 non-labeled BMSCs were respectively transplanted into both groups of rats through the right carotid artery （cells were harvested in 1 mL phosphate buffered saline）. MAIN OUTCOME MEASURES： Feridex-labeled BMSCs were observed by Prussian blue staining and electron microscopy. Signal intensity, celluar viability, and proliferative capacity of BMSCs were measured using MRI, Trypan blue test, and M-IT assay, respectively. Distribution of transplanted cells was observed in rats utilizing MRI and Prussian blue staining prior to and 1, 3, 7, and 14 days after transplantation. RESULTS： Prussian blue staining displayed many blue granules in the Feridex-labeled BMSCs. High density of iron granules was observed in the cytoplasm under electron microscopy. According to MRI results, and compared with the non-labeled group, the signal intensity was decreased in the Feridex-labeled group （P 〈 0.05）. The decrease was most significant in the 50 pg/mL Feridex-labeled group （P 〈 0.01）. There were no significant differences in celluar viability and proliferation of BMSCs between the Feridex-labeled and non-labeled groups after 1 week （P 〉 0.05）. Low-signal lesions were detected in the rat hippocampus and temporal cortex at 3 days after transplantation. The low-signal lesions were still detectable at 14 days, and positively stained cells were observed in the hippocampus and temporal cortex using Prussian blue staining. There were no significant differences in signal intensity in the non-labeled group. CONCLUSION： BMSC transplantation traversed the blood-brain barrier and distributed into vulnerable zones in a rat model of cardiac arrest-induced global brain ischemia. MRI provided a non-invasive method to in vivo dynamically and spatially trace Feridex-labeled BMSCs after transplantation.展开更多
AIM:To study the expression of embryonal markers by fetal cardiac mesenchymal stem cells(fC-MSC)and their differentiation into cells of all the germ layers. METHODS:Ten independent cultures of rat fCMSC were set up fr...AIM:To study the expression of embryonal markers by fetal cardiac mesenchymal stem cells(fC-MSC)and their differentiation into cells of all the germ layers. METHODS:Ten independent cultures of rat fCMSC were set up from cells derived from individual or pooled fetal hearts and studies given below were carried out at passages 3,6,15 and 21.The phenotypic markers CD29,CD31,CD34,CD45,CD73,CD90, CD105,CD166 and HLA-DR were analyzed by flow cytometry.The expression of embryonal markers Oct-4, Nanog,Sox-2,SSEA-1,SSEA-3,SSEA-4,TRA-1-60 and TRA 1-81 were studied by immunocytochemistry.The fC-MSC treated with specific induction medium were evaluated for their differentiation into(1)adipocytes and osteocytes(mesodermal cells)by Oil Red O and Alizarin Red staining,respectively,as well as by expression of lipoprotein lipase,PPARγ2 genes in adipocytes and osteopontin and RUNX2 genes in osteocytes by reverse-transcription polymerase chain reaction(RT- PCR);(2)neuronal(ectodermal)cells by expression of neuronal Filament-160 and Glial Fibrillar Acidic Protein by RT-PCR and immunocytochemistry;and(3)hepa- tocytic(endodermal)cells by expression of albumin by RT-PCR and immunocytochemistry,glycogen deposits by Periodic Acid Schiff staining and excretion of urea into the culture supernatant. RESULTS:The fC-MSC expressed CD29,CD73,CD90, CD105,CD166 but lacked expression of CD31,CD34, CD45 and HLA-DR.They expressed embryonal markers,viz.Oct-4,Nanog,Sox-2,SSEA-1,SSEA-3,SSEA-4, TRA-1-81 but not TRA-1-60.On treatment with specific induction media,they differentiated into adipocytes and osteocytes,neuronal cells and hepatocytic cells. CONCLUSION:Our results together suggest that fCMSC are primitive stem cell types with a high degree of plasticity and,in addition to their suitability for cardiovascular regenerative therapy,they may have a wide spectrum of therapeutic applications in regenerative medicine.展开更多
Objectives To investigate the anti-apoptotic effects of mesenchymal stem cells （MSCs） on hypoxic injured cardiac myocytes in vitro. Methods MSCs were isolated from bone marrow of Sprague-Dawley （SD） rats, and card...Objectives To investigate the anti-apoptotic effects of mesenchymal stem cells （MSCs） on hypoxic injured cardiac myocytes in vitro. Methods MSCs were isolated from bone marrow of Sprague-Dawley （SD） rats, and cardiac myocytes from neonatal rats. The rat cardiac myocytes were co-cultured with MSCs or MSC-conditioned media in anoxia （95% N2 ±5% CO2） for 72 hours. Cell apoptosis was measured by Hoechst 33258 staining. The expression of Bcl-2 and Bax in cardiac myocytes was tested by Western Blot. Results The apoptotic rate was 51.6% ± 2.4% when cardiac myocytes were cultured in continuous hypoxia and was significantly decreased when cardiac myocytes were cocultured with MSCs or MSC-conditioned media （ 15.1% ± 5.4% and 24. 0% ± 4.2% respectively, P 〈 0. 001 ）. The decreased expression of Bax in the cardiac myocytes was greatly related to the decreasing of apoptosis, but there was no difference in Bcl-2 expression among these groups. Conclusions Co-cultured MSCs showed significant anti-apoptotic effects on cardiac myocytes in continuous hypoxia. The mechanism may be the interact of cell to cell and paracrine of cytokines which effected the expression of Bax in the cardiac myocytes.展开更多
Despite optimal interventional and medical therapy, ischemic heart disease is still an important cause of morbidity and mortality worldwide. Although not included in standard of care rehabilitation, stem cell therapy(...Despite optimal interventional and medical therapy, ischemic heart disease is still an important cause of morbidity and mortality worldwide. Although not included in standard of care rehabilitation, stem cell therapy(SCT) could be a solution for prompting cardiac regeneration. Multiple studies have been published from the beginning of SCT until now, but overall no unanimous conclusion could be drawn in part due to the lack of appropriate endpoints. In order to appreciate the impact of SCT, multiple markers from different categories should be considered: Structural, biological, functional, physiological, but also major adverse cardiac events or quality of life. Imaging end-points are among the most used-especially left ventricle ejection fraction(LVEF) measured through different methods. Other imaging parameters are infarct size, myocardial viability and perfusion. The impact of SCT on all of the aforementioned end-points is controversial and debatable. 2 D-echocardiography is widely exploited, but new approaches such as tissue Doppler, strain/strain rate or 3 D-echocardiography are more accurate, especially since the latter one is comparable with the MRI gold standard estimation of LVEF. Apart from the objective parameters, there are also patient-centered evaluations to reveal the benefits of SCT, such as quality of life and performance status, the most valuable from the patient point of view. Emerging parameters investigating molecular pathways such as non-coding RNAs or inflammation cytokines have a high potential as prognostic factors. Due to the disadvantages of current techniques, new imaging methods with labelled cells tracked along their lifetime seem promising, but until now only pre-clinical trials have been conducted in humans. Overall, SCT is characterized by high heterogeneity not only in preparation, administration and type of cells, but also in quantification of therapy effects.展开更多
It has been researched that myocardial infarction(MI)has drastically affected patients all over the world.The current guidelines of the medical treatments including PTCA or CABG just improve the condition and reduce d...It has been researched that myocardial infarction(MI)has drastically affected patients all over the world.The current guidelines of the medical treatments including PTCA or CABG just improve the condition and reduce damage to an extent.In the new studies and recent updates on myocardial stem cells,it has been researched that myocardial stem cells have regenerative capacity.Stem cell therapy used in cardiac disease management shows a promising and novel approach for cardiac tissues,cardiac muscle repair,and regeneration.Furthermore,it’s been observed that the stem cell-derived paracrine factors help in regulating and remodeling the coronary artery inflammation and cardiac tissue generation in the MI region.Here,we highlight recent findings and discuss how they use stem cell therapy during MI and heart disease.展开更多
It has been a decade since the monumental discovery of resident stem cells in the mammalian heart, and the following studies witnessed the continuous turnover of cardiomyocytes and vascular cells, maintaining the home...It has been a decade since the monumental discovery of resident stem cells in the mammalian heart, and the following studies witnessed the continuous turnover of cardiomyocytes and vascular cells, maintaining the homeostasis of the organ. Recently, the autologous administration of c-kit-positive cardiac stem cells in patients with ischemic heart failure has led to an incredible outcome; the left ventricular ejection fraction of the celltreated group improved from 30% at the baseline to 38% after one year and to 42% after two years of cell injection. The potential underlying mechanisms, before and after cell infusion, are explored and discussed in this article. Some of them are related to the intrinsic property of the resident stem cells, such as direct differentiation, paracrine action, and immunomodulatory function, whereas others involve environmental factors, leading to cellular reverse remodeling and to the natural selection of "juvenile" cells. It has now been demonstrated that cardiac stem cells for therapeutic purposes can be prepared from tiny biopsied specimens of the failing heart as well as from frozen tissues, which may remarkably expand the repertoire of the strategy against various cardiovascular disorders, including non-ischemic cardiomyopathy and congenital heart diseases. Further translational investigations are needed to explore these possibilities.展开更多
Cardiovascular diseases(CVDs) continue to represent the number one cause of death and disability in industrialized countries. The most severe form of CVD is acute myocardial infarction(AMI), a devastating disease asso...Cardiovascular diseases(CVDs) continue to represent the number one cause of death and disability in industrialized countries. The most severe form of CVD is acute myocardial infarction(AMI), a devastating disease associated with high mortality and disability. In a substantial proportion of patients who survive AMI, loss of functional cardiomyocytes as a result of ischaemic injury leads to ventricular failure, resulting in significant alteration to quality of life and increased mortality. Therefore, many attempts have been made in recent years to identify new tools for the regeneration of functional cardiomyocytes. Regenerative therapy currently represents the ultimate goal for restoring the function of damaged myocardium by stimulating the regeneration of the infarcted tissue or by providing cellsthat can generate new myocardial tissue to replace the damaged tissue. Stem cells(SCs) have been proposed as a viable therapy option in these cases. However, despite the great enthusiasm at the beginning of the SC era, justified by promising initial results, this therapy has failed to demonstrate a significant benefit in large clinical trials. One interesting finding of SC studies is that exosomes released by mesenchymal SCs(MSCs) are able to enhance the viability of cardiomyocytes after ischaemia/reperfusion injury, suggesting that the beneficial effects of MSCs in the recovery of functional myocardium could be related to their capacity to secrete exosomes. Ten years ago, it was discovered that exosomes have the unique property of transferring miRNA between cells, acting as miRNA nanocarriers. Therefore, exosomebased therapy has recently been proposed as an emerging tool for cardiac regeneration as an alternative to SC therapy in the post-infarction period. This review aims to discuss the emerging role of exosomes in developing innovative therapies for cardiac regeneration as well as their potential role as candidate biomarkers or for developing new diagnostic tools.展开更多
AIM: To facilitate engineering of suitable biomaterials to meet the challenges associated with myocardial infarction. METHODS: Poly (glycerol sebacate)/collagen (PGS/ collagen) core/shell fibers were fabricated by cor...AIM: To facilitate engineering of suitable biomaterials to meet the challenges associated with myocardial infarction. METHODS: Poly (glycerol sebacate)/collagen (PGS/ collagen) core/shell fibers were fabricated by core/ shell electrospinning technique, with core as PGS and shell as collagen polymer; and the scaffolds were characterized by scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), contact angle and tensile testing for cardiac tissue engineering. Collagen nanofibers were also fabricated by electrospinning for comparison with core/shell fibers. Studies on cell-scaffold interaction were carriedout using cardiac cells and mesenchymal stem cells (MSCs) co-culture system with cardiac cells and MSCs separately serving as positive and negative controls respectively. The co-culture system was characterized for cell proliferation and differentiation of MSCs into cardiomyogenic lineage in the co-culture environment using dual immunocytochemistry. The co-culture cells were stained with cardiac specific marker proteins like actinin and troponin and MSC specific marker protein CD 105 for proving the cardiogenic differentiation of MSCs. Further the morphology of cells was analyzed using SEM.RESULTS: PGS/collagen core/shell fibers, core is PGS polymer having an elastic modulus related to that of cardiac fibers and shell as collagen, providing natural environment for cellular activities like cell adhesion, proliferation and differentiation. SEM micrographs of electrospun fibrous scaffolds revealed porous, beadless, uniform fibers with a fiber diameter in the range of 380 ± 77 nm and 1192 ± 277 nm for collagen fibers and PGS/collagen core/shell fibers respectively. The obtained PGS/collagen core/shell fibrous scaffolds were hydrophilic having a water contact angle of 17.9 ± 4.6° compared to collagen nanofibers which had a contact angle value of 30 ± 3.2°. The PGS/collagen core/shell fibers had mechanical properties comparable to that of native heart muscle with a young's modulus of 4.24 ± 0.7 MPa, while that of collagen nanofibers was comparatively higher around 30.11 ± 1.68 MPa. FTIR spectrum was performed to confirm the functional groups present in the electrospun scaffolds. Amide Ⅰ and amide Ⅱ of collagen were detected at 1638.95 cm -1 and 1551.64 cm -1 in the electrospun collagen fibers and at 1646.22 cm -1 and 1540.73 cm -1 for PGS/collagen core/shell fibers respectively. Cell culture studies performed using MSCs and cardiac cells co-culture environment, indicated that the cellproliferation significantly increased on PGS/collagen core/shell scaffolds compared to collagen fibers and the cardiac marker proteins actinin and troponin were expressed more on PGS/collagen core/shell scaffolds compared to collagen fibers alone. Dual immunofluorescent staining was performed to further confirm the cardiogenic differentiation of MSCs by employing MSC specific marker protein, CD 105 and cardiac specific marker protein, actinin. SEM observations of cardiac cells showed normal morphology on PGS/collagen fibers and providing adequate tensile strength for the regeneration of myocardial infarction. CONCLUSION: Combination of PGS/collagen fibers and cardiac cells/MSCs co-culture system providing natural microenvironments to improve cell survival and differentiation, could bring cardiac tissue engineering to clinical application.展开更多
Objectives To explore the possibility to induce mesenchymal stem cells from human fetal livers （FMSCs） to differentiate along cardiac lineage and the way to obtain high rate of differentiation. Methods Cells from pa...Objectives To explore the possibility to induce mesenchymal stem cells from human fetal livers （FMSCs） to differentiate along cardiac lineage and the way to obtain high rate of differentiation. Methods Cells from passage 6-9 were plated at the density of 1.5 × 10^4/cm^2 and were treated with the combination of 5-azacytine（5-aza）, retinoitic acid（RA） and Dimethylsulfoxide （DMSO） in different doses when near confluence. 24 hours later, the treatment was removed by changing into normal medium without inducers. Different culture conditions were tried, including temperature, oxygen content and medium. Results When FMSCs were treated with highdose combination （ 5-aza 50 μM ＋RA 10-1 μM ＋ DMSO 1%） and modified combination（5-aza 50 μM ＋RA 10-3 μM ＋ DMSO 0.8 %） in cardiac differentiation medium （CDM）, at 37℃ and 20% 02, the cardiac differentiation was induced. When near confluence, cells became round and tended to gather together to form ball-like structures. 3 weeks after treatment, the cells were harvested and stained with anti-desmin and cardiac troponin I antibodies, and about 40% of the cells were positively stained. No beating cells observed during observation. Conclusions FMSCs cardiac have lineage the potential to differentiate along , and the stimulus for the cardiac differentiation is different from those for MSCs from different species.展开更多
Recent studies suggest that whole bone marrow (WBM) derived stem cells may facilitate recovery following myocardial infarction. However, the sub-population of WBM responsible for recovery remains uncertain. By adjusti...Recent studies suggest that whole bone marrow (WBM) derived stem cells may facilitate recovery following myocardial infarction. However, the sub-population of WBM responsible for recovery remains uncertain. By adjusting the abundance of CD34+LinNeg cells in human bone marrow we examined the relative significance of hematopoietic stem cells (HSC) in the recovery of cardiac function in a murine model of induced myocardial infarction. Enrichment of HSC by ~100-fold in WBM transplanted into mice significantly increased recovery of heart function and reduced scar size compared to transplantation of WBM depleted in HSC by ~10-fold (P P < 0.01 respectively). Peri-infarct capillary density was significantly increased in recipients of HSC-enriched samples (P < 0.01) or WBM samples (P < 0.01) compared to controls. These results strongly suggest?a critical role for HSC in the effective treatment of myocardial infarction with human bone marrow, and imply that enrichment of HSC may markedly benefit the clinical application of WBM treatments.展开更多
Objective：To investigate the effect of MCP-1 on mesenchymal stem cells（MSCs） homing to injured myocardium in a rat myocardial infarction（MI） model. Methods：Rat myocardial infarction model was established by perm...Objective：To investigate the effect of MCP-1 on mesenchymal stem cells（MSCs） homing to injured myocardium in a rat myocardial infarction（MI） model. Methods：Rat myocardial infarction model was established by permanent left anterior descending branch ligation. Mesenchymal stem cells from donor rats were cultured in IMDM and labeled with BrdU. The Rats were divided into two groups. Monocyte chemotactic protein I（MCP-1） expression were measured by in situ hybridization and immunohistochemistry in the sham operated or infarcted hearts at 1, 2, 4, 7, 14 and 28 days post operation in MCP-1 detection group. The rats were injected with MCP-1, anti-MCP-1 antibody or saline 4 days after myocardial infarction in intervention group. Then, a total of 5 × 10^6 cells in 2.5 ml of PBS were injected through the tail vein. The number of the labeled MSCs in the infarcted hearts was counted 3 days post injection. Cardiac function and blood vessel density were assessed 28 days post injection. Results：Self-generating MCP-1 expression was increased at the first day, peaked at the 7^th day and decreased thereafter post MI and remained unchanged in sham operated hearts. The MSCs enrichment in the host hearts were more abundant in the MI groups than that in the non-MI group（P= 0.000）, the MSCs enrichment in the host hearts were more abundant in the MCP-1 injected group than that in the anti-MCP-1 antibody and saline injected groups （P = 0.000）. Cardiac function was improved more in MCP-1 injected group than anti-MCP-1 antibody and saline injected groups（P= 0.000）. Neovascularization in MCP-1 injected group significantly increased compared with that of other groups（P = 0.000）. Conclusion： Myocardial MCP-1 expression was increased only in the early phase post MI. MCP-1 may enhance MSCs homing to the injured heart and improve cardiac function by promoting neovascularization.展开更多
基金Science and Technology Development Fund,No.28932Cardiovascular Research,Education,Prevention Foundation,CVREP-Dr.Wael Al Mahmeed Grant.
文摘Regenerative medicine is the field concerned with the repair and restoration of the integrity of damaged human tissues as well as whole organs.Since the inception of the field several decades ago,regenerative medicine therapies,namely stem cells,have received significant attention in preclinical studies and clinical trials.Apart from their known potential for differentiation into the various body cells,stem cells enhance the organ's intrinsic regenerative capacity by altering its environment,whether by exogenous injection or introducing their products that modulate endogenous stem cell function and fate for the sake of regeneration.Recently,research in cardiology has highlighted the evidence for the existence of cardiac stem and progenitor cells(CSCs/CPCs).The global burden of cardiovascular diseases’morbidity and mortality has demanded an in-depth understanding of the biology of CSCs/CPCs aiming at improving the outcome for an innovative therapeutic strategy.This review will discuss the nature of each of the CSCs/CPCs,their environment,their interplay with other cells,and their metabolism.In addition,important issues are tackled concerning the potency of CSCs/CPCs in relation to their secretome for mediating the ability to influence other cells.Moreover,the review will throw the light on the clinical trials and the preclinical studies using CSCs/CPCs and combined therapy for cardiac regeneration.Finally,the novel role of nanotechnology in cardiac regeneration will be explored.
文摘The emergence of cardiac stem cell therapy can be traced to late 2001, when studies in small animal models of myocardial infarction suggested that stem cells could engraft, proliferate, and regenerate myo-cardium. Subsequent animal laboratory studies showed improved cardiac function, perfusion and survival compared to controls (Figure 1). Within two years, the first clinical trials of stem cell therapy began to appear, and we now have several trials of intracoronary infusion of bone marrow cells with more than one year follow-up. Although this clinical therapy has proven to be safe, the magnitude of improvement in objective measures like ejection fraction has been modest, and the therapy has not entered clinical practice. In the absence of a large prospective randomized trial, the field has moved back to the laboratory. This manuscript aims to provide clinicians with a broad overview of this complex field by briefly reviewing the existing status of clinical myocardial regeneration therapy, then describing selected examples from the laboratory research approaches that may provide a platform for new and potentially increasingly effective clinical strategies.
基金Rio de Janeiro State Research Foundation,No.252042,No.250671 and No.241703.
文摘Cardiovascular diseases represent the world’s leading cause of death. In thisheterogeneous group of diseases, ischemic cardiomyopathies are the mostdevastating and prevalent, estimated to cause 17.9 million deaths per year.Despite all biomedical efforts, there are no effective treatments that can replacethe myocytes lost during an ischemic event or progression of the disease to heartfailure. In this context, cell therapy is an emerging therapeutic alternative to treatcardiovascular diseases by cell administration, aimed at cardiac regeneration andrepair. In this review, we will cover more than 30 years of cell therapy in cardiology,presenting the main milestones and drawbacks in the field and signalingfuture challenges and perspectives. The outcomes of cardiac cell therapies arediscussed in three distinct aspects: The search for remuscularization byreplacement of lost cells by exogenous adult cells, the endogenous stem cell era,which pursued the isolation of a progenitor with the ability to induce heart repair,and the utilization of pluripotent stem cells as a rich and reliable source ofcardiomyocytes. Acellular therapies using cell derivatives, such as microvesiclesand exosomes, are presented as a promising cell-free therapeutic alternative.
基金supported by grants from the National Natural Science Foundation of China (Grant Nos.81170121,81460042,81541004 and 81670254)Science and Technology Project of Guangdong Province (2016A020214016)+1 种基金YangFan Plan of Guangdong Province (4YF16007G)Excellent Graduate Student Training Program of Guangdong Medical University (YS2014013)
文摘Hypoxia is beneficial for the differentiation of stem cells transplanted for myocardial injury,but mechanisms underlying this benefit remain unsolved. Here, we report the impact of hypoxia-induced Jagged1 expression in cardiomyocytes(CMs) for driving the differentiation of cardiac stem cells(CSCs).Forced hypoxia-inducible factor 1α(HIF-1α) expression and physical hypoxia(5% O_2) treatment could induce Jagged1 expression in neonatal rat CMs. Pharmacological inhibition of HIF-1α by YC-1 attenuated hypoxia-promoted Jagged1 expression in CMs. An ERK inhibitor(PD98059), but not inhibitors of JNK(SP600125), Notch(DAPT), NF-κB(PTDC), JAK(AG490), or STAT3(Stattic) suppressed hypoxiainduced Jagged1 protein expression in CMs. c-Kit^+ CSCs isolated from neonatal rat hearts using a magnetic-activated cell sorting method expressed GATA4, SM22α or vWF, but not Nkx2.5 and cTnI.Moreover, 87.3% of freshly isolated CSCs displayed Notch1 receptor expression. Direct co-culture of CMs with BrdU-labeled CSCs enhanced CSCs differentiation, as evidenced by an increased number of BrdU^+/Nkx2.5^+ cells, while intermittent hypoxia for 21 days promoted co-culture-triggered differentiation of CSCs into CM-like cells. Notably, YC-1 and DAPT attenuated hypoxia-induced differentiation.Our results suggest that hypoxia induces Jagged1 expression in CMs primarily through ERK signaling,and facilitates early cardiac lineage differentiation of CSCs in CM/CSC co-cultures via HIF-1α/Jagged1/Notch signaling.
文摘Over the last years, stem cell therapy has emerged asan inspiring alternative to restore cardiac function after myocardial infarction. A large body of evidence has been obtained in this field but there is no conclusive data on the efficacy of these treatments. Preclinical studies and early reports in humans have been encouraging and have fostered a rapid clinical translation, but positive results have not been uniformly observed and when present, they have been modest. Several types of stem cells, manufacturing methods and delivery routes have been tested in different clinical settings but direct comparison between them is challenging and hinders further research. Despite enormous achievements, major barriers have been found and many fundamental issues remain to be resolved. A better knowledge of the molecular mechanisms implicated in cardiac development and myocardial regeneration is critically needed to overcome some of these hurdles. Genetic and pharmacological priming together with the discovery of new sources of cells have led to a "second generation" of cell products that holds an encouraging promise in cardiovascular regenerative medicine. In this report, we review recent advances in this field focusing on the new types of stem cells that are currently being tested in human beings and on the novel strategies employed to boost cell performance in order to improve cardiac function and outcomes after myocardial infarction.
文摘Causative mutations and variants associated with cardiac diseases have been found in genes encoding cardiac ion channels, accessory proteins, cytoskeletal components, junctional proteins, and signaling molecules. In most cases the functional evaluation of the genetic alterationhas been carried out by expressing the mutated proteins in in-vitro heterologous systems. While these studies have provided a wealth of functional details that have greatly enhanced the understanding of the pathological mechanisms, it has always been clear that heterologous expression of the mutant protein bears the intrinsic limitation of the lack of a proper intracellular environment and the lack of pathological remodeling. The results obtained from the application of the next generation sequencing technique to patients suffering from cardiac diseases have identified several loci, mostly in non-coding DNA regions, which still await functional analysis. The isolation and culture of human embryonic stem cells has initially provided a constant source of cells from which cardiomyocytes(CMs) can be obtained by differentiation. Furthermore, the possibility to reprogram cellular fate to a pluripotent state, has opened this process to the study of genetic diseases. Thus induced pluripotent stem cells(i PSCs) represent a completely new cellular model that overcomes the limitations of heterologous studies. Importantly, due to the possibility to keep spontaneously beating CMs in culture for several months, during which they show a certain degree of maturation/aging, this approach will also provide a system in which to address the effect of long-term expression of the mutated proteins or any other DNA mutation, in terms of electrophysiological remodeling. Moreover, since i PSC preserve the entire patients' genetic context, the system will help the physicians in identifying the most appropriate pharmacological intervention to correct the functional alteration. This article summarizes the current knowledge of cardiac genetic diseases modelled with i PSC.
基金the National Natural Science Foundation of China,No.30801081, 30870691,30700303the New Teacher Foundation of Doctor Center of Ministry of Education of China,No. 200805581179
文摘BACKGROUND： Numerous studies have shown that magnetic resonance imaging （MRI） can detect survival and migration of super paramagnetic iron oxide-labeled stem cells in models of focal cerebral infarction. OBJECTIVE： To observe distribution of bone marrow mesenchymal stem cells （BMSCs） in a rat model of global brain ischemia following cardiac arrest and resuscitation, and to investigate the feasibility of tracing iron oxide-labeled BMSCs using non-invasive MRI. DESIGN, TIME AND SETTING： The randomized, controlled, molecular imaging study was performed at the Linbaixin Medical Research Center, Second Affiliated Hospital, Sun Yat-sen University, and the Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, China from October 2006 to February 2009. MATERIALS： A total of 40 clean, Sprague Dawley rats, aged 6 weeks and of either gender, were supplied by the Experimental Animal Center, Sun Yat-sen University, China, for isolation of BMSCs. Feridex （iron oxide）, Gyroscan Inetra 1.5T MRI system, and cardiopulmonary resuscitation device were used in this study. METHODS： A total of 30 healthy, male Sprague Dawiey rats, aged 6 months, were used to induce ventricular fibrillation using alternating current. After 8 minutes, the rats underwent 6-minute chest compression and mechanical ventilation, followed by electric defibrillation, to establish rat models of global brain ischemia due to cardiac arrest and resuscitation. A total of 24 successful models were randomly assigned to Feridex-labeled and non-labeled groups （n = 12 for each group）. At 2 hours after resuscitation, 5 ×10^8 Feridex-labeled BMSCs, with protamine sulfate as a carrier, and 5 ×10^6 non-labeled BMSCs were respectively transplanted into both groups of rats through the right carotid artery （cells were harvested in 1 mL phosphate buffered saline）. MAIN OUTCOME MEASURES： Feridex-labeled BMSCs were observed by Prussian blue staining and electron microscopy. Signal intensity, celluar viability, and proliferative capacity of BMSCs were measured using MRI, Trypan blue test, and M-IT assay, respectively. Distribution of transplanted cells was observed in rats utilizing MRI and Prussian blue staining prior to and 1, 3, 7, and 14 days after transplantation. RESULTS： Prussian blue staining displayed many blue granules in the Feridex-labeled BMSCs. High density of iron granules was observed in the cytoplasm under electron microscopy. According to MRI results, and compared with the non-labeled group, the signal intensity was decreased in the Feridex-labeled group （P 〈 0.05）. The decrease was most significant in the 50 pg/mL Feridex-labeled group （P 〈 0.01）. There were no significant differences in celluar viability and proliferation of BMSCs between the Feridex-labeled and non-labeled groups after 1 week （P 〉 0.05）. Low-signal lesions were detected in the rat hippocampus and temporal cortex at 3 days after transplantation. The low-signal lesions were still detectable at 14 days, and positively stained cells were observed in the hippocampus and temporal cortex using Prussian blue staining. There were no significant differences in signal intensity in the non-labeled group. CONCLUSION： BMSC transplantation traversed the blood-brain barrier and distributed into vulnerable zones in a rat model of cardiac arrest-induced global brain ischemia. MRI provided a non-invasive method to in vivo dynamically and spatially trace Feridex-labeled BMSCs after transplantation.
基金Supported by Department of Biotechnology,Government of India,BT/PR6519/MED/14/826/2005,to Dr.Nityanand S
文摘AIM:To study the expression of embryonal markers by fetal cardiac mesenchymal stem cells(fC-MSC)and their differentiation into cells of all the germ layers. METHODS:Ten independent cultures of rat fCMSC were set up from cells derived from individual or pooled fetal hearts and studies given below were carried out at passages 3,6,15 and 21.The phenotypic markers CD29,CD31,CD34,CD45,CD73,CD90, CD105,CD166 and HLA-DR were analyzed by flow cytometry.The expression of embryonal markers Oct-4, Nanog,Sox-2,SSEA-1,SSEA-3,SSEA-4,TRA-1-60 and TRA 1-81 were studied by immunocytochemistry.The fC-MSC treated with specific induction medium were evaluated for their differentiation into(1)adipocytes and osteocytes(mesodermal cells)by Oil Red O and Alizarin Red staining,respectively,as well as by expression of lipoprotein lipase,PPARγ2 genes in adipocytes and osteopontin and RUNX2 genes in osteocytes by reverse-transcription polymerase chain reaction(RT- PCR);(2)neuronal(ectodermal)cells by expression of neuronal Filament-160 and Glial Fibrillar Acidic Protein by RT-PCR and immunocytochemistry;and(3)hepa- tocytic(endodermal)cells by expression of albumin by RT-PCR and immunocytochemistry,glycogen deposits by Periodic Acid Schiff staining and excretion of urea into the culture supernatant. RESULTS:The fC-MSC expressed CD29,CD73,CD90, CD105,CD166 but lacked expression of CD31,CD34, CD45 and HLA-DR.They expressed embryonal markers,viz.Oct-4,Nanog,Sox-2,SSEA-1,SSEA-3,SSEA-4, TRA-1-81 but not TRA-1-60.On treatment with specific induction media,they differentiated into adipocytes and osteocytes,neuronal cells and hepatocytic cells. CONCLUSION:Our results together suggest that fCMSC are primitive stem cell types with a high degree of plasticity and,in addition to their suitability for cardiovascular regenerative therapy,they may have a wide spectrum of therapeutic applications in regenerative medicine.
文摘Objectives To investigate the anti-apoptotic effects of mesenchymal stem cells （MSCs） on hypoxic injured cardiac myocytes in vitro. Methods MSCs were isolated from bone marrow of Sprague-Dawley （SD） rats, and cardiac myocytes from neonatal rats. The rat cardiac myocytes were co-cultured with MSCs or MSC-conditioned media in anoxia （95% N2 ±5% CO2） for 72 hours. Cell apoptosis was measured by Hoechst 33258 staining. The expression of Bcl-2 and Bax in cardiac myocytes was tested by Western Blot. Results The apoptotic rate was 51.6% ± 2.4% when cardiac myocytes were cultured in continuous hypoxia and was significantly decreased when cardiac myocytes were cocultured with MSCs or MSC-conditioned media （ 15.1% ± 5.4% and 24. 0% ± 4.2% respectively, P 〈 0. 001 ）. The decreased expression of Bax in the cardiac myocytes was greatly related to the decreasing of apoptosis, but there was no difference in Bcl-2 expression among these groups. Conclusions Co-cultured MSCs showed significant anti-apoptotic effects on cardiac myocytes in continuous hypoxia. The mechanism may be the interact of cell to cell and paracrine of cytokines which effected the expression of Bax in the cardiac myocytes.
文摘Despite optimal interventional and medical therapy, ischemic heart disease is still an important cause of morbidity and mortality worldwide. Although not included in standard of care rehabilitation, stem cell therapy(SCT) could be a solution for prompting cardiac regeneration. Multiple studies have been published from the beginning of SCT until now, but overall no unanimous conclusion could be drawn in part due to the lack of appropriate endpoints. In order to appreciate the impact of SCT, multiple markers from different categories should be considered: Structural, biological, functional, physiological, but also major adverse cardiac events or quality of life. Imaging end-points are among the most used-especially left ventricle ejection fraction(LVEF) measured through different methods. Other imaging parameters are infarct size, myocardial viability and perfusion. The impact of SCT on all of the aforementioned end-points is controversial and debatable. 2 D-echocardiography is widely exploited, but new approaches such as tissue Doppler, strain/strain rate or 3 D-echocardiography are more accurate, especially since the latter one is comparable with the MRI gold standard estimation of LVEF. Apart from the objective parameters, there are also patient-centered evaluations to reveal the benefits of SCT, such as quality of life and performance status, the most valuable from the patient point of view. Emerging parameters investigating molecular pathways such as non-coding RNAs or inflammation cytokines have a high potential as prognostic factors. Due to the disadvantages of current techniques, new imaging methods with labelled cells tracked along their lifetime seem promising, but until now only pre-clinical trials have been conducted in humans. Overall, SCT is characterized by high heterogeneity not only in preparation, administration and type of cells, but also in quantification of therapy effects.
文摘It has been researched that myocardial infarction(MI)has drastically affected patients all over the world.The current guidelines of the medical treatments including PTCA or CABG just improve the condition and reduce damage to an extent.In the new studies and recent updates on myocardial stem cells,it has been researched that myocardial stem cells have regenerative capacity.Stem cell therapy used in cardiac disease management shows a promising and novel approach for cardiac tissues,cardiac muscle repair,and regeneration.Furthermore,it’s been observed that the stem cell-derived paracrine factors help in regulating and remodeling the coronary artery inflammation and cardiac tissue generation in the MI region.Here,we highlight recent findings and discuss how they use stem cell therapy during MI and heart disease.
基金The Japan Society for the Promotion of Science Grant-in-Aid for Scientific Research(C),No.25461118
文摘It has been a decade since the monumental discovery of resident stem cells in the mammalian heart, and the following studies witnessed the continuous turnover of cardiomyocytes and vascular cells, maintaining the homeostasis of the organ. Recently, the autologous administration of c-kit-positive cardiac stem cells in patients with ischemic heart failure has led to an incredible outcome; the left ventricular ejection fraction of the celltreated group improved from 30% at the baseline to 38% after one year and to 42% after two years of cell injection. The potential underlying mechanisms, before and after cell infusion, are explored and discussed in this article. Some of them are related to the intrinsic property of the resident stem cells, such as direct differentiation, paracrine action, and immunomodulatory function, whereas others involve environmental factors, leading to cellular reverse remodeling and to the natural selection of "juvenile" cells. It has now been demonstrated that cardiac stem cells for therapeutic purposes can be prepared from tiny biopsied specimens of the failing heart as well as from frozen tissues, which may remarkably expand the repertoire of the strategy against various cardiovascular disorders, including non-ischemic cardiomyopathy and congenital heart diseases. Further translational investigations are needed to explore these possibilities.
基金Supported by Research grant,No.103544/2016-PLaqueIMAGE,contract No.26/01.09.2016financed by the Romanian Ministry of European Funds,the Romanian Government and the European Union
文摘Cardiovascular diseases(CVDs) continue to represent the number one cause of death and disability in industrialized countries. The most severe form of CVD is acute myocardial infarction(AMI), a devastating disease associated with high mortality and disability. In a substantial proportion of patients who survive AMI, loss of functional cardiomyocytes as a result of ischaemic injury leads to ventricular failure, resulting in significant alteration to quality of life and increased mortality. Therefore, many attempts have been made in recent years to identify new tools for the regeneration of functional cardiomyocytes. Regenerative therapy currently represents the ultimate goal for restoring the function of damaged myocardium by stimulating the regeneration of the infarcted tissue or by providing cellsthat can generate new myocardial tissue to replace the damaged tissue. Stem cells(SCs) have been proposed as a viable therapy option in these cases. However, despite the great enthusiasm at the beginning of the SC era, justified by promising initial results, this therapy has failed to demonstrate a significant benefit in large clinical trials. One interesting finding of SC studies is that exosomes released by mesenchymal SCs(MSCs) are able to enhance the viability of cardiomyocytes after ischaemia/reperfusion injury, suggesting that the beneficial effects of MSCs in the recovery of functional myocardium could be related to their capacity to secrete exosomes. Ten years ago, it was discovered that exosomes have the unique property of transferring miRNA between cells, acting as miRNA nanocarriers. Therefore, exosomebased therapy has recently been proposed as an emerging tool for cardiac regeneration as an alternative to SC therapy in the post-infarction period. This review aims to discuss the emerging role of exosomes in developing innovative therapies for cardiac regeneration as well as their potential role as candidate biomarkers or for developing new diagnostic tools.
基金Supported by NRF-Technion, No. R-398-001-065-592Ministry of Education, No. R-265-000-318-112NUSNNI, National University of Singapore
文摘AIM: To facilitate engineering of suitable biomaterials to meet the challenges associated with myocardial infarction. METHODS: Poly (glycerol sebacate)/collagen (PGS/ collagen) core/shell fibers were fabricated by core/ shell electrospinning technique, with core as PGS and shell as collagen polymer; and the scaffolds were characterized by scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), contact angle and tensile testing for cardiac tissue engineering. Collagen nanofibers were also fabricated by electrospinning for comparison with core/shell fibers. Studies on cell-scaffold interaction were carriedout using cardiac cells and mesenchymal stem cells (MSCs) co-culture system with cardiac cells and MSCs separately serving as positive and negative controls respectively. The co-culture system was characterized for cell proliferation and differentiation of MSCs into cardiomyogenic lineage in the co-culture environment using dual immunocytochemistry. The co-culture cells were stained with cardiac specific marker proteins like actinin and troponin and MSC specific marker protein CD 105 for proving the cardiogenic differentiation of MSCs. Further the morphology of cells was analyzed using SEM.RESULTS: PGS/collagen core/shell fibers, core is PGS polymer having an elastic modulus related to that of cardiac fibers and shell as collagen, providing natural environment for cellular activities like cell adhesion, proliferation and differentiation. SEM micrographs of electrospun fibrous scaffolds revealed porous, beadless, uniform fibers with a fiber diameter in the range of 380 ± 77 nm and 1192 ± 277 nm for collagen fibers and PGS/collagen core/shell fibers respectively. The obtained PGS/collagen core/shell fibrous scaffolds were hydrophilic having a water contact angle of 17.9 ± 4.6° compared to collagen nanofibers which had a contact angle value of 30 ± 3.2°. The PGS/collagen core/shell fibers had mechanical properties comparable to that of native heart muscle with a young's modulus of 4.24 ± 0.7 MPa, while that of collagen nanofibers was comparatively higher around 30.11 ± 1.68 MPa. FTIR spectrum was performed to confirm the functional groups present in the electrospun scaffolds. Amide Ⅰ and amide Ⅱ of collagen were detected at 1638.95 cm -1 and 1551.64 cm -1 in the electrospun collagen fibers and at 1646.22 cm -1 and 1540.73 cm -1 for PGS/collagen core/shell fibers respectively. Cell culture studies performed using MSCs and cardiac cells co-culture environment, indicated that the cellproliferation significantly increased on PGS/collagen core/shell scaffolds compared to collagen fibers and the cardiac marker proteins actinin and troponin were expressed more on PGS/collagen core/shell scaffolds compared to collagen fibers alone. Dual immunofluorescent staining was performed to further confirm the cardiogenic differentiation of MSCs by employing MSC specific marker protein, CD 105 and cardiac specific marker protein, actinin. SEM observations of cardiac cells showed normal morphology on PGS/collagen fibers and providing adequate tensile strength for the regeneration of myocardial infarction. CONCLUSION: Combination of PGS/collagen fibers and cardiac cells/MSCs co-culture system providing natural microenvironments to improve cell survival and differentiation, could bring cardiac tissue engineering to clinical application.
文摘Objectives To explore the possibility to induce mesenchymal stem cells from human fetal livers （FMSCs） to differentiate along cardiac lineage and the way to obtain high rate of differentiation. Methods Cells from passage 6-9 were plated at the density of 1.5 × 10^4/cm^2 and were treated with the combination of 5-azacytine（5-aza）, retinoitic acid（RA） and Dimethylsulfoxide （DMSO） in different doses when near confluence. 24 hours later, the treatment was removed by changing into normal medium without inducers. Different culture conditions were tried, including temperature, oxygen content and medium. Results When FMSCs were treated with highdose combination （ 5-aza 50 μM ＋RA 10-1 μM ＋ DMSO 1%） and modified combination（5-aza 50 μM ＋RA 10-3 μM ＋ DMSO 0.8 %） in cardiac differentiation medium （CDM）, at 37℃ and 20% 02, the cardiac differentiation was induced. When near confluence, cells became round and tended to gather together to form ball-like structures. 3 weeks after treatment, the cells were harvested and stained with anti-desmin and cardiac troponin I antibodies, and about 40% of the cells were positively stained. No beating cells observed during observation. Conclusions FMSCs cardiac have lineage the potential to differentiate along , and the stimulus for the cardiac differentiation is different from those for MSCs from different species.
文摘Recent studies suggest that whole bone marrow (WBM) derived stem cells may facilitate recovery following myocardial infarction. However, the sub-population of WBM responsible for recovery remains uncertain. By adjusting the abundance of CD34+LinNeg cells in human bone marrow we examined the relative significance of hematopoietic stem cells (HSC) in the recovery of cardiac function in a murine model of induced myocardial infarction. Enrichment of HSC by ~100-fold in WBM transplanted into mice significantly increased recovery of heart function and reduced scar size compared to transplantation of WBM depleted in HSC by ~10-fold (P P < 0.01 respectively). Peri-infarct capillary density was significantly increased in recipients of HSC-enriched samples (P < 0.01) or WBM samples (P < 0.01) compared to controls. These results strongly suggest?a critical role for HSC in the effective treatment of myocardial infarction with human bone marrow, and imply that enrichment of HSC may markedly benefit the clinical application of WBM treatments.
文摘Objective：To investigate the effect of MCP-1 on mesenchymal stem cells（MSCs） homing to injured myocardium in a rat myocardial infarction（MI） model. Methods：Rat myocardial infarction model was established by permanent left anterior descending branch ligation. Mesenchymal stem cells from donor rats were cultured in IMDM and labeled with BrdU. The Rats were divided into two groups. Monocyte chemotactic protein I（MCP-1） expression were measured by in situ hybridization and immunohistochemistry in the sham operated or infarcted hearts at 1, 2, 4, 7, 14 and 28 days post operation in MCP-1 detection group. The rats were injected with MCP-1, anti-MCP-1 antibody or saline 4 days after myocardial infarction in intervention group. Then, a total of 5 × 10^6 cells in 2.5 ml of PBS were injected through the tail vein. The number of the labeled MSCs in the infarcted hearts was counted 3 days post injection. Cardiac function and blood vessel density were assessed 28 days post injection. Results：Self-generating MCP-1 expression was increased at the first day, peaked at the 7^th day and decreased thereafter post MI and remained unchanged in sham operated hearts. The MSCs enrichment in the host hearts were more abundant in the MI groups than that in the non-MI group（P= 0.000）, the MSCs enrichment in the host hearts were more abundant in the MCP-1 injected group than that in the anti-MCP-1 antibody and saline injected groups （P = 0.000）. Cardiac function was improved more in MCP-1 injected group than anti-MCP-1 antibody and saline injected groups（P= 0.000）. Neovascularization in MCP-1 injected group significantly increased compared with that of other groups（P = 0.000）. Conclusion： Myocardial MCP-1 expression was increased only in the early phase post MI. MCP-1 may enhance MSCs homing to the injured heart and improve cardiac function by promoting neovascularization.
