Efficacy of stem cell in improvement of left ventricular function in acute myocardial infarction--MI3 Trial

Mid- to long-term efficacy and safety of stem cell therapy for acute myocardial infarction: a systematic review and meta-analysis

BACKGROUND

This comprehensive systematic review and meta-analysis investigated the mid- to long-term efficacy and safety of stem cell therapy in patients with acute myocardial infarction (AMI).

METHODS

The study encompassed 79 randomized controlled trials with 7103 patients, rendering it the most up-to-date and extensive analysis in this field. This study specifically focused on the impact of stem cell therapy on left ventricular ejection fraction (LVEF), major adverse cardiac events (MACE), and infarct size.

RESULTS

Stem cell therapy significantly improved LVEF at 6, 12, 24, and 36 months post-transplantation compared to control values, indicating its potential for long-term cardiac function enhancement. A trend toward reduced MACE occurrence was observed in the intervention groups, suggesting the potential of stem cell therapy to lower the risk of cardiovascular death, reinfarction, and stroke. Significant LVEF improvements were associated with long cell culture durations exceeding 1 week, particularly when combined with high injected cell quantities (at least 108 cells). No significant reduction in infarct size was observed.

CONCLUSIONS

This review highlights the potential of stem cell therapy as a promising therapeutic approach for patients with AMI, offering sustained LVEF improvement and a potential reduction in MACE risk. However, further research is required to optimize cell culture techniques, determine the optimal timing and dosage, and investigate procedural variations to maximize the efficacy and safety of stem cell therapy in this context.

Isolation of Swine Bone Marrow Lin-/CD45-/CD133 + Cells and Cardio-protective Effects of its Exosomes

BACKGROUND

The identification in murine bone marrow (BM) of CD133 + /Lin-/CD45- cells, possessing several features of pluripotent stem cells, encouraged us to investigate if similar population of cells could be also isolated from the swine BM. Heart failure is the terminal stage of many cardiovascular diseases, and its key pathological basis is cardiac fibrosis (CF). Research showed that stem cell derived exosomes may play a critical role in cardiac fibrosis. The effect of exosomes (Exos) on CF has remained unclear.

OBJECTIVE

To establish an isolation and amplification method of CD133 + /Lin-/CD45- cells from newbron swine BM in vitro, explore an highly efficient method to enrich swine bone marrow derived CD133 + /Lin-/CD45- cells and probe into their biological characteristics further. Furher more, to extract exosomes from it and explore its effect on CF.

METHODS

The mononuclear cells isolated from swine bone marrow by red blood cell (RBC) lysing buffer were coated by adding FcR blocking solution and coupled with CD133 antibody immunomagnetic beads, obtaining CD133 + cell group via Magnetic Activated Cell Sorting (MACS). In steps, the CD133 + /Lin-/CD45- cells were collected by fluorescence-activated cell sorting (FACS) labeled with CD133, Lin and CD45 antibodies, which were cultured and amplified in vitro. The biological features of CD133 + /Lin-/CD45- cells were studied in different aspects, including morphological trait observed with inverted microscope, ultrastructural characteristics observed under transmission electron microscope, expression of pluripotent markersidentified by immunofluorescent staining and Alkaline phosphatase staining. The Exos were extracted using a sequential centrifugation approach and its effects on CF were analyzed in Angiotensin II (Ang-II) induced-cardiac fibrosis in vivo. Rats in each group were treated for 4 weeks, and 2D echocardiography was adopted to evaluate the heart function. The degree of cardiac fibrosis was assessed by Hematoxylin-Eosin (HE) and Masson's trichrome staining.

RESULTS

The CD133 + /Lin-/CD45- cells accounted for about 0.2%-0.5% of the total mononuclear cells isolated from swine bone marrow. The combination of MACS and FACS to extract CD133 + /Lin-/CD45- cells could improved efficiency and reduced cell apoptosis. The CD133 + /Lin-/CD45- cells featured typical traits of pluripotent stem cells, the nucleus is large, mainly composed of euchromatin, with less cytoplasm and larger nucleoplasmic ratio, which expressed pluripotent markers (SSEA-1, Oct-4, Nanog and Sox-2) and alkaline phosphatase staining was positive.Animal experiment indicated that the cardiac injury related indexes (BNP、cTnI、CK-MB and TNF-α), the expression of key gene Smad3 and the degree of cardiac fibrosis in Exo treatment group were significantly reduced compared with the control group. 4 weeks after the treatment, cardiac ejection fraction (EF) value in the model group showed a remarkable decrease, indicating the induction of HF model. While Exo elevated the EF values, demonstrating cardio-protective effects.

CONCLUSION

The CD133 + /Lin-/CD45- cells derived from swine bone marrow were successfully isolated and amplified, laying a good foundation for further research on this promising therapeutic cell. The Exos may be a promising potential treatment strategy for CF.

Stem Cell Therapy for the Treatment of Myocardial Infarction: How Far Are We Now?

Myocardial infarction is one of the leading causes of death worldwide. Poor functional recovery of the myocardium is noticed after an event of myocardial infarction. Researchers and clinicians around the world have been engaged to regenerate the damaged human heart for a long time. Stem cell therapy is an exciting newer therapy to treat cardiovascular diseases.

Various types of stem cells have been used to revive the damaged myocardium after myocardial infarction, and they have overall demonstrated safety and moderate efficacy. The specific mechanisms by which these cells help in improving cardiac function are still not completely known. There is growing evidence that intracoronary bone marrow cell transplantation in patients with myocardial infarction beneficially affects the remodeling of the damaged myocardium.

Our systematic review article aims to assess the effects and the future of stem cell therapy in patients with myocardial Infarction. We searched articles in PubMed, ScienceDirect, and Google Scholar. Thirty-one studies that included 2171 patients in total were analyzed. Most of these studies showed stem cell therapy is safe and well tolerated in patients, and modest improvements are seen in left ventricular functions with no major adverse effects. However, some studies showed no positive and clinically significant outcomes. So, more high-quality studies on a larger scale are required to support and confirm its efficacy in remodeling damaged myocardium after myocardial infarction. We should also perform studies to determine the timing of cell delivery that is best suited for stem cell therapy.

Stem Cell Therapy for Acute Myocardial Infarctions: A Systematic Review

Each year 790,000 people in the United States suffer from a myocardial infarction. This results in the permanent loss of cardiomyocytes and an irreversible loss of cardiac function. Current therapies lower mortality rates, but do not address the core pathology, which opens a pathway to step-wise heart failure. Utilizing stem cells to regenerate the dead tissue is a potential method to reverse these devastating effects. Several clinical trials have already demonstrated the safety of stem cell therapy. In this review, we highlight clinical trials, which have utilized various stem cell lineages, and discuss areas for future research.

Therapeutic Use of Stem Cells for Myocardial Infarction

Myocardial infarction is a leading cause of morbidity and mortality worldwide. Although medical and surgical treatments can significantly improve patient outcomes, no treatment currently available is able to generate new contractile tissue or reverse ischemic myocardium. Driven by the recent/novel understanding that regenerative processes do exist in the myocardium—tissue previously thought not to possess regenerative properties—the use of stem cells has emerged as a promising therapeutic approach with high expectations. The literature describes the use of cells from various sources, categorizing them as either embryonic, induced pluripotent, or adult/tissue stem cells (mesenchymal, hematopoietic, skeletal myoblasts, cardiac stem cells). Many publications show the successful use of these cells to regenerate damaged myocardium in both animal and human models; however, more studies are needed to directly compare cells of various origins in efforts to draw conclusions on the ideal source. Although numerous challenges exist in this developing area of research and clinical practice, prospects are encouraging. The following aims to provide a concise review outlining the different types of stem cells used in patients after myocardial infarction.

Regenerative abilities of mesenchymal stem cells through mitochondrial transfer

The past decade has witnessed an upsurge in studies demonstrating mitochondrial transfer as one of the emerging mechanisms through which mesenchymal stem cells (MSCs) can regenerate and repair damaged cells or tissues. It has been found to play a critical role in healing several diseases related to brain injury, cardiac myopathies, muscle sepsis, lung disorders and acute respiratory disorders. Several studies have shown that various mechanisms are involved in mitochondrial transfer that includes tunnel tube formation, micro vesicle formation, gap junctions, cell fusion and others modes of transfer. Few studies have investigated the mechanisms that contribute to mitochondrial transfer, primarily comprising of signaling pathways involved in tunnel tube formation that facilitates tunnel tube formation for movement of mitochondria from one cell to another. Various stress signals such as release of damaged mitochondria, mtDNA and mitochondrial products along with elevated reactive oxygen species levels trigger the transfer of mitochondria from MSCs to recipient cells. However, extensive cell signaling pathways that lead to mitochondrial transfer from healthy cells are still under investigation and the changes that contribute to restoration of mitochondrial bioenergetics in recipient cells remain largely elusive. In this review, we have discussed the phenomenon of mitochondrial transfer from MSCs to neighboring stressed cells, and how this aids in cellular repair and regeneration of different organs such as lung, heart, eye, brain and kidney. The potential scope of mitochondrial transfer in providing novel therapeutic strategies for treatment of various pathophysiological conditions has also been discussed.

Evaluating KIND1 human embryonic stem cell-derived pancreatic progenitors to ameliorate streptozotocin-induced diabetes in mice

Background & objectives:

Diabetes is a global disease burden. Various stem cell types are being explored to serve as an alternative source of islets. This study was conducted to evaluate the ability of in-house developed human embryonic stem (hES) cells-derived pancreatic progenitors to ameliorate diabetic symptoms in mice.

Methods:

Pancreatic progenitors were packed in macro-capsules and transplanted into six male Swiss mice and four mice were taken as controls. Thirty days post-transplantation, diabetes was induced by streptozotocin treatment. Mice were then followed up for >100 days and body weight and blood glucose levels were regularly monitored.

Results:

Control mice lost weight, maintained high glucose levels and did not survive beyond 40 days, whereas transplanted group maintained body weight and four of the six mice had lowered blood glucose levels. About five-fold increase was observed in human C-peptide levels in the recipients of progenitor transplants as compared to diabetic control.

Interpretation & conclusions:

The beneficial effect of transplanted cells was not long-lasting. Further studies are required to critically evaluate and compare the potential of endogenous pluripotent stem cells and hES cells-derived progenitors before moving from bench to the bedside.