Trials and tribulations of cell therapy for heart failure: an update on ongoing trials

Interpenetrating network hydrogel-loaded embryonic stem cell-derived endocardial cells improves cardiac function after myocardial infarction

BACKGROUND

With an in-depth understanding of cardiac cell differentiation, cell therapy derived from stem cells has shown promising therapeutic effects in the treatment of myocardial infarction (MI). Although many types of cardiac or noncardiac cells have been found to play protective roles in MI, the specific role of endocardial cells (ECCs) in MI has not been reported.

METHODS

The current study was designed to determine whether human embryonic stem cell (hESC)-derived endocardial cells (hESC-ECCs) could be protective against MI. We first developed a cell delivery system by constructing a photosensitive interpenetrating network hydrogel consisting of gelatin methacryloyl (GelMA) and silk fibroin methacryloyl (SilMA). The sorted hESC-ECCs were loaded into the delivery system and then injected into the pericardium cavity of the MI rats.

RESULTS

These results show that the cell delivery system has good biocompatibility. Moreover, the delivered endocardial cells improved cardiac function and delayed capillary atrophy after MI. Further mechanistic analysis revealed that hESC-ECCs protect the mitochondria of cardiomyocytes from damage under oxidative stress and potentially promote the angiogenesis of cardiac endothelial cells.

CONCLUSION

Our results demonstrated that hESC-ECCs have the potential to serve as a cell therapy strategy for MI treatment by maintaining cardiomyocyte survival and facilitating angiogenesis.

Progress and challenges in developing allogeneic cell therapies

The new era of cell therapeutics has started with autologous products to avoid immune rejection. However, therapeutics derived from allogeneic cells could be scaled and made available for a much larger patient population if immune rejection could reliably be overcome. In this review, we outline gene engineering concepts aimed at generating immune-evasive cells. First, we summarize the current state of allogeneic immune cell therapies, and second, we compile the still limited data for allogeneic cell replacement therapies. We emphasize the advances in this fast-developing field and provide an optimistic outlook for future allogeneic cell therapies.

Allogeneic mesenchymal stem cell therapy with laromestrocel in mild Alzheimer's disease: a randomized controlled phase 2a trial

Alzheimer's disease (AD) is characterized by progressive cognitive decline, severe brain atrophy and neuroinflammation. We conducted a randomized, double-blind, placebo-controlled, parallel-group phase 2a clinical trial that tested the safety and efficacy of laromestrocel, a bone-marrow-derived, allogeneic mesenchymal stem-cell therapy, in slowing AD clinical progression, atrophy and neuroinflammation. Participants across ten centers in the United States were randomly assigned 1:1:1:1 to four infusion groups: group 1 (placebo; four monthly infusions, n = 12); group 2 (25 million cells, one infusion followed by three monthly infusions of placebo, n = 13); group 3 (25 million cells; four monthly doses, n = 13); and group 4 (100 million cells; four monthly doses, n = 11). The study met its primary end point of safety; the rate of treatment-emergent serious adverse events within 4 weeks of any infusion was similar in all four groups: group 1, 0% (95% CI 0-26.5%); group 2, 7.7% (95% CI 0.2-36%); group 3, 7.7% (95% CI 0.2-36%) and group 4, 9.1% (95% CI 0.2-41.3%). Additionally, there were no reported infusion-related reactions, hypersensitivities or amyloid-related imaging abnormalities. Laromestrocel improved clinical assessments at 39 weeks compared to placebo, as measured by a composite AD score (secondary end point was met: group 2 versus placebo change: 0.38; 95% CI -0.06-0.82), Montreal cognitive assessment and the Alzheimer's Disease Cooperative Study Activities of Daily Living. At 39 weeks, Laromestrocel slowed the decline of whole brain volume compared to placebo (n = 10) by 48.4% for all treatment groups combined (groups 2-4: P = 0.005; n = 32) and left hippocampal volume by 61.9% (groups 2-4, P = 0.021; n = 32), and reduced neuroinflammation as measured by diffusion tensor imaging. The change in bilateral hippocampal atrophy correlated with the change in mini-mental state exam scores (R = 0.41, P = 0.0075) in all study patients (N = 42). Collectively these results support safety of single and multiple doses of laromestrocel treatment for mild AD and provide indications of efficacy in combating decline of brain volume and potentially cognitive function. Larger-scale clinical trials of laromestrocel in AD are warranted. ClinicalTrials.gov registration: NCT05233774 .

Bone Marrow Niche in Cardiometabolic Disease: Mechanisms and Therapeutic Potential

Cardiovascular and cardiometabolic diseases are leading causes of morbidity and mortality worldwide, driven in part by chronic inflammation. Emerging research suggests that the bone marrow microenvironment, or marrow niche, plays a critical role in both immune system regulation and disease progression. The bone marrow niche is essential for maintaining hematopoietic stem cells (HSCs) and orchestrating hematopoiesis. Under normal conditions, this niche ensures a return to immune homeostasis after acute stress. However, in the setting of inflammatory conditions such as those seen in cardiometabolic diseases, it becomes dysregulated, leading to enhanced myelopoiesis and immune activation. This review explores the reciprocal relationship between the bone marrow niche and cardiometabolic diseases, highlighting how alterations in the niche contribute to disease development and progression. The niche regulates HSCs through complex interactions with stromal cells, endothelial cells, and signaling molecules. However, in the setting of chronic diseases such as hypertension, atherosclerosis, and diabetes, inflammatory signals disrupt the balance between HSC self-renewal and differentiation, promoting the excessive production of proinflammatory myeloid cells that exacerbate the disease. Key mechanisms discussed include the effects of hyperlipidemia, hyperglycemia, and sympathetic nervous system activation on HSC proliferation and differentiation. Furthermore, the review emphasizes the role of epigenetic modifications and metabolic reprogramming in creating trained immunity, a phenomenon whereby HSCs acquire long-term proinflammatory characteristics that sustain disease states. Finally, we explore therapeutic strategies aimed at targeting the bone marrow niche to mitigate chronic inflammation and its sequelae. Novel interventions that modulate hematopoiesis and restore niche homeostasis hold promise for the treatment of cardiometabolic diseases. By interrupting the vicious cycle of inflammation and marrow dysregulation, such therapies may offer new avenues for reducing cardiovascular risk and improving patient outcomes.