New treatment strategy for severe heart failure: combination of ventricular assist device and regenerative therapy

Prognosis of Patients With Heart Failure Receiving Autologous Myoblast Patches - Comparison of Single-Arm Trial Data to Registry Data

BACKGROUND

Clinical studies in regenerative medicine remain insufficient in Japan due to ethical concerns regarding the control group and a lack of statistical methodology to evaluate efficacy in a small treatment group. This study evaluated the efficacy of autologous myoblast patch (AMP) treatment for heart failure using restricted mean survival time (RMST) analysis by comparing data from a small single-arm trial to epidemiological data from a registry.

METHODS AND RESULTS

The clinical trial arm included 55 patients with advanced ischemic cardiomyopathy who received an AMP between 2010 and 2020. The registry-based control group comprised 937 participants with severely impaired left ventricular function who were hospitalized for heart failure during the study period. Due to the limited number of patients, RMST analysis was used to compare survival between the 2 groups. Cox regression analyses revealed non-significant differences in survival between the groups at 3, 3.5, and 4 years. In contrast, RMST analyses revealed significant differences in survival at 3 years (P=0.008) and 3.5 (P=0.024) years, but not at 4 years.

CONCLUSIONS

This small single-arm trial using RMST analyses was able to detect the efficacy of AMP transplantation for advanced heart failure (compared with a registry-based control group), with better survival until 3.5 years. This approach may be useful for efficacy analyses in regenerative medicine, where traditional clinical trials are difficult.

2,5-Dimethylcelecoxib attenuates cardiac fibrosis caused by cryoinjury-induced myocardial infarction by suppressing the fibroblast-to-myofibroblast transformation via inhibition of the TGF-β signaling pathway

We previously reported that 2,5-dimethylcelecoxib (DM-C), a derivative of celecoxib, lacks cyclooxygenase-2 inhibitory effects and suppresses cardiac remodeling by activating glycogen synthase kinase-3 (GSK-3). However, it remains unclear whether DM-C attenuates fibroblast-to-myofibroblast transformation (FMT), which plays a key role in cardiac fibrosis. Therefore, we evaluated the effect of DM-C on FMT using a cryoinjury-induced myocardial infarction (CMI) mouse model. We found that DM-C attenuated the deterioration of left ventricular ejection fraction after CMI by decreasing cardiac fibrosis. Analysis of the expression level of α-smooth muscle actin (α-SMA), a marker for myofibroblasts, indicated that DM-C decreased FMT at the cardiac injury site. To investigate the mechanism by which DM-C attenuated FMT, fibroblasts obtained from the heart were stimulated with TGF-β to induce FMT, and the effect of DM-C was analyzed. DM-C suppressed the expression of α-SMA and the phosphorylation levels of Smad 2/3 and GSK-3, indicating that DM-C suppressed α-SMA expression by inhibiting the transforming growth factor (TGF)-β signaling pathway via activation of GSK-3. DM-C decreased the expression of collagen, connective tissue growth factor (CTGF) and Snail, which are also known to accelerate cardiac fibrosis. These results suggested that DM-C attenuated cardiac fibrosis by suppressing FMT at the injured site after CMI by inhibiting the TGF-β signaling pathway via activation of GSK-3. Thus, DM-C has potential against cardiac disease as a novel anti-fibrotic agent.

Strategies for immune regulation in iPS cell-based cardiac regenerative medicine

Cardiac regenerative therapy is expected to be a promising therapeutic option for the treatment of severe cardiovascular diseases. Artificial tissues or organoids made from cardiovascular cell lineages differentiated from human induced pluripotent stem cells (iPSCs) are expected to regenerate the damaged heart. Even though immune rejection rarely occurs when iPSC-derived graft and the recipient have the same HLA type, in some cases, such as tissue transplantation onto hearts, the HLA matching would not be sufficient to fully control immune rejection. The present review introduces recent immunomodulatory strategies in iPSC-based transplantation therapies other than MHC matching including the induction of immune tolerance through iPSC-derived antigen-presenting cells, simultaneous transplantation of syngeneic mesenchymal stem cells, and using the universal donor cells such as gene editing-based HLA modulation in iPSCs to regulate T cell compatibility. In addition, we present future perspectives for proper adjustment of immunosuppression therapy after iPSC-derived tissue/organoid-based cardiac regenerative therapies by identifying biomarkers monitoring immune rejection.