Meta-analysis of short- and long-term efficacy of mononuclear cell transplantation in patients with myocardial infarction

Preventive Effect of Bone Marrow Mononuclear Cell Transplantation on Acute Myocardial Infarction-Induced Heart Failure: A Meta-analysis of Randomized Controlled Trials

PURPOSE

Heart failure (HF) is a major complication of acute myocardial infarction (AMI). Transplantation of bone marrow mononuclear cells (BM-MNC) in the setting of AMI has been proposed as a means for myocardial tissue regeneration. Several trials have explored the outcomes of these cells on surrogate end points such as left ventricular ejection fraction (LVEF) in patients with AMI. However, the data regarding the clinical efficacy are infrequent. Here, we performed a meta-analysis investigating the effect of BM-MNCs injection on the rate of hospitalization for HF in the long-term follow-up period.

METHODS

PubMed, Scopus, and Cochrane databases were queried with various combinations of keywords through May 2, 2022. A random-effects meta-analysis was performed to calculate risk ratio (RR) and 95% confidence interval (CI) of hospitalization for HF, all-cause mortality, and stroke rate. Subgroup analyses for hospitalization based on time and cell dose were performed.

RESULTS

A total of 2150 patients with AMI across 22 trials were included for quantitative synthesis. At long-term follow-up, AMI patients treated with an intracoronary injection of BM-MNCs were less likely to be hospitalized for heart failure compared to the control group receiving standard treatment (RR = 0.54, 95% CI = [0.37; 0.78], p = 0.002). There was no association between BM-MNC therapy and all-cause mortality (RR = 0.69, 95% CI = [0.47; 1.01], p = 0.05) and stroke (RR = 1.12, 95% CI= [0.24; 5.21], p = 0.85).

CONCLUSION

Autologous injection of BM-MNC in the setting of AMI may be associated with decreased risk of hospitalization of heart failure in the long term. However, its effect on all-cause mortality and stroke rate is questionable.

New treatment methods for myocardial infarction

For a long time, cardiovascular clinicians have focused their research on coronary atherosclerotic cardiovascular disease and acute myocardial infarction due to their high morbidity, high mortality, high disability rate, and limited treatment options. Despite the continuous optimization of the therapeutic methods and pharmacological therapies for myocardial ischemia-reperfusion, the incidence rate of heart failure continues to increase year by year. This situation is speculated to be caused by the current therapies, such as reperfusion therapy after ischemic injury, drugs, rehabilitation, and other traditional treatments, that do not directly target the infarcted myocardium. Consequently, these therapies cannot fundamentally solve the problems of myocardial pathological remodeling and the reduction of cardiac function after myocardial infarction, allowing for the progression of heart failure after myocardial infarction. Coupled with the decline in mortality caused by acute myocardial infarction in recent years, this combination leads to an increase in the incidence of heart failure. As a new promising therapy rising at the beginning of the twenty-first century, cardiac regenerative medicine provides a new choice and hope for the recovery of cardiac function and the prevention and treatment of heart failure after myocardial infarction. In the past two decades, regeneration engineering researchers have explored and summarized the elements, such as cells, scaffolds, and cytokines, required for myocardial regeneration from all aspects and various levels day and night, paving the way for our later scholars to carry out relevant research and also putting forward the current problems and directions for us. Here, we describe the advantages and challenges of cardiac tissue engineering, a contemporary innovative therapy after myocardial infarction, to provide a reference for clinical treatment.

Comparing the effect of bone marrow mono-nuclear cells with mesenchymal stem cells after acute myocardial infarction on improvement of left ventricular function: a meta-analysis of clinical trials

BACKGROUND

The effect of transplantation of bone-marrow mononuclear cells (BM-MNCs) and mesenchymal stem cells (MSCs) on ejection fraction (LVEF) has been studied in patients with acute myocardial infarction (AMI) in clinical trials. This raises the question that which type of cell may help improve LVEF better in AMI patients. No meta-analysis of clinical trials has yet addressed this question.

METHODS

Electronic databases were searched thoroughly to find eligible trials on the effects of transplantation of BM-MNCs and MSCs in patients with AMI. The primary outcome was improvement in LVEF. Data were synthesized using random-effects meta-analysis. For maximizing the credibility of subgroup analysis, we used the instrument for assessing the Credibility of Effect Modification of Analyses (ICEMAN) for meta-analyses.

RESULTS

A total of 36 trials (26 on BM-MNCs and 10 on MSCs) with 2489 patients (1466 were transplanted [1241 with BM-MNCs and 225 with MSCs] and 1023 as controls) were included. Both types of cells showed significant improvements in ejection fraction in short-term follow-up (BM-MNCs: WMD = 2.13%, 95% CI = 1.23 to 3.04, p < 0.001; MSCs: WMD = 3.71%, 95% CI = 2.32 to 5.09, p < 0.001), and according to ICEMAN criteria, MSCs are more effective. For selected population of patients who received stem cell transplantation in early course after AMI (less than 11 days), this effect was even more pronounced (BM-MNC: WMD = 3.07%, 95% CI = 1.97 to 4.17, p < 0.001, I² = 40.7%; MSCs: WMD = 5.65%, 95% CI = 3.47 to 7.84, p < 0.001, I² = 84.6%).

CONCLUSION

Our results showed that transplantation of MSCs after AMI might increase LVEF more than BM-MNCs; also, based on ICEMAN, there was likely effect modification between subgroups although uncertainty still remained.

Autophagy stimulation delayed biological aging and decreased cardiac differentiation in rabbit mesenchymal stem cells

Introduction: Cardiovascular disease (CVD) is a type of disease that affects the function of cardiac-vascular tissues. This study aimed to consider the possible effects of autophagy, as an intrinsic catabolic pathway of cells, on the differentiation and aging process of mesenchymal stem cells (MSCs).

Methods: In this study, bone marrow-derived MSCs were obtained from rabbit bone marrow aspirates. The stemness feature was confirmed by using flow cytometry analysis Cells at passage three were treated with 50 μM Metformin and 15μM hydroxychloroquine (HCQ) for 72 hours. The intracellular accumulation of autophagolysosomes was imaged using LysoTracker staining. Protein levels of autophagy (LC3II/I ratio), aging (Klotho, PARP-1, and Sirt-1) effectors, and cardiomyocyte-like phenotype (α-actinin) were studied by western blotting.

Results: Based on our findings, flow cytometry analysis showed that the obtained cells expressed CD44 and CD133 strongly, and CD31 and CD34 dimly, showing a typical characteristic of MSCs. Our data confirmed an increased LC3II/I ratio in the metformin-received group compared to the untreated and HCQ-treated cells (P < 0.05). Besides, we showed that the incubation of rabbit MSCs with HCQ increased cellular aging by induction of PARP-1 while Metformin increased rejuvenating factor Sirt-1 comparing with the normal group (P < 0.05). Western blotting data showed that the autophagy stimulation response in rabbit MSCs postponed the biological aging and decreased the differentiation potential to the cardiac cells by diminishing α-actinin comparing with control cells (P < 0.05).

Conclusion: In summary, for the informants in this study, it could be noted that autophagy inhibition/stimulation could alter rabbit MSCs aging and differentiation capacity.