Daily Cardiology Research Analysis
Mechanistic and translational advances dominate today’s cardiology literature: two studies uncover druggable regulated cell death pathways in myocardial injury (cuproptosis via LRP6–ALKBH5–FDX1 and ferroptosis via CTSL–PDIA4) with therapeutic benefit in preclinical models, including pigs. A complementary platform rapidly generates functional vascular organoids from iPSCs, enabling in vivo revascularization and disease modeling.
Summary
Mechanistic and translational advances dominate today’s cardiology literature: two studies uncover druggable regulated cell death pathways in myocardial injury (cuproptosis via LRP6–ALKBH5–FDX1 and ferroptosis via CTSL–PDIA4) with therapeutic benefit in preclinical models, including pigs. A complementary platform rapidly generates functional vascular organoids from iPSCs, enabling in vivo revascularization and disease modeling.
Research Themes
- Regulated cardiomyocyte death pathways (cuproptosis and ferroptosis) as therapeutic targets after myocardial infarction
- Translational biomaterials for targeted drug delivery and cardiac repair
- Rapid vascular organoid platforms for cardiovascular modeling and regenerative therapy
Selected Articles
1. Janus hydrogels delivering low-density lipoprotein receptor-related protein 6 inhibitor enhance myocardial repair via m6A-dependent cuproptosis in bama pigs.
This translational study identifies LRP6 as a central driver of copper-induced cuproptosis in infarcted myocardium via an ALKBH5–m6A–FDX1 axis and copper influx. Delivery of an LRP6 inhibitor (C7Og) using an adhesive Janus hydrogel myocardial patch reduced infarct size and improved cardiac function in rats and Bama miniature pigs.
Impact: It uncovers a druggable mechanism of cardiomyocyte death after MI and demonstrates efficacy in a large-animal model, a key translational milestone.
Clinical Implications: LRP6 inhibition and hydrogel-based localized delivery may evolve into a therapeutic strategy to limit infarct expansion and improve remodeling post-MI, pending human safety and efficacy studies.
Key Findings
- MI elevated myocardial copper and activated nuclear LRP6, which interacted with ALKBH5 to suppress m6A modification of FDX1, promoting cuproptosis.
- Chrysin-7-O-glucuronide (C7Og) was identified as a potent LRP6 inhibitor that mitigated cuproptosis without compromising cardiac protective effects.
- A benzalkonium chloride–modified tannic acid Janus hydrogel enhanced adhesion and delivery; C7Og myocardial patches reduced infarct size and improved function in rat and Bama miniature pig models.
Methodological Strengths
- Mechanistic dissection of the LRP6–ALKBH5–FDX1 axis with targeted inhibition and functional readouts
- Demonstration of efficacy in both small (rat) and large (Bama miniature pig) animal MI models using an engineered biomaterial delivery system
Limitations
- Preclinical models only; no human safety, pharmacokinetics, or long-term outcomes reported
- Potential off-target effects of C7Og and immune responses to the hydrogel were not fully characterized
Future Directions: First-in-human dose-escalation studies of localized LRP6 inhibition, biodistribution and durability testing, and head-to-head comparisons with standard post-MI therapies.
Copper overload induces a unique form of cell death called cuproptosis via mitochondrial ROS accumulation. Following myocardial infarction (MI), copper ion levels rise significantly in infarcted tissue. Cardiomyocytes, highly sensitive to copper, respond through activation and nuclear translocation of LRP6, which interacts with ALKBH5 to suppress m6A modification of ferredoxin 1 (FDX1), thereby exacerbating copper toxicity. LRP6 also facilitates copper influx, further promoting cuproptosis. High-throughput screening identified chrysin-7-O-glucuronide (C7Og) as a potent LRP6 inhibitor that mitigates cuproptosis without compromising cardiac protective effects. Moreover, a Janus hydrogel enhanced with benzalkonium chloride-modified tannic acid improves tissue adhesion and glucose delivery. A myocardial patch integrating C7Og within this hydrogel significantly reduced infarct size and improved cardiac function in both rat and Bama miniature pig models, highlighting strong translational potential for MI therapy. STATEMENT OF SIGNIFICANCE: This study uncovers a mechanism of copper-induced cell death, termed cuproptosis, in myocardial infarction (MI). It identifies low-density lipoprotein receptor-related protein 6 (LRP6) as a key regulator of copper influx and cuproptosis, revealing a potential target for mitigating copper toxicity in cardiac tissue. Chrysin-7-O-glucuronide (C7Og), a potent LRP6 inhibitor, offers a promising strategy to prevent LRP6-mediated cell death while preserving its protective role in cardiac function. Encapsulating C7Og in a Janus hydrogel enhances its delivery and adhesion, demonstrating significant efficacy in reducing myocardial damage and improving cardiac function in rat and Bama miniature pig models. This work offers new insights into copper homeostasis and presents a potential therapeutic approach for MI treatment.
2. Rapid generation of functional vascular organoids via simultaneous transcription factor activation of endothelial and mural lineages.
The authors establish a 5-day, ECM-free protocol to generate functional vascular organoids from iPSCs by orthogonal activation of ETV2 and NKX3.1, with tunable endothelial phenotypes. These organoids engrafted, formed perfused vessels, and enhanced revascularization in vivo, providing a versatile platform for cardiovascular modeling and regenerative applications.
Impact: It delivers a generalizable, rapid method to co-differentiate and assemble endothelial and mural compartments, validated by in vivo perfusion and therapeutic revascularization.
Clinical Implications: While preclinical, the platform enables scalable vascular grafts and disease modeling (e.g., atherosclerosis, PAH), accelerating translational testing of pro- or anti-angiogenic therapies.
Key Findings
- Orthogonal activation of ETV2 and NKX3.1 via Dox or modRNA produces functional vascular organoids from iPSCs in 5 days without ECM embedding.
- Single-cell RNA-seq revealed vascular heterogeneity; temporal TF regulation modulated arterial and angiogenic endothelial phenotypes.
- In vivo, organoids engrafted, formed perfused vasculature, and enhanced revascularization in hind limb ischemia and supported pancreatic islet transplantation.
Methodological Strengths
- Robust, rapid differentiation using orthogonal TF activation (Dox-inducible and modRNA) with ECM-independent assembly
- In vivo validation of perfusion and therapeutic revascularization; single-cell transcriptomic characterization
Limitations
- Use of immunodeficient mice and short-term assessments; durability and maturation in large-animal or human settings remain unknown
- Safety endpoints (e.g., ectopic growth, tumorigenicity, arrhythmogenic risk when combined with cardiac tissues) not detailed
Future Directions: Scale-up under GMP, long-term functional integration studies, disease-specific modeling (e.g., diabetic vasculopathy), and large-animal testing toward clinical translation.
Vascular organoids (VOs) are valuable tools for studying vascular development, disease, and regenerative medicine. However, controlling endothelial and mural compartments independently remains challenging. Here, we present a streamlined method to generate VOs from induced pluripotent stem cells (iPSCs) via orthogonal activation of the transcription factors (TFs) ETV2 and NKX3.1 using Dox-inducible or modRNA systems. This approach enables efficient co-differentiation of endothelial cells (iECs) and mural cells (iMCs), producing functional 3D VOs in 5 days without ECM embedding. VOs matured further upon ECM exposure, forming larger, structured vessels. Single-cell RNA sequencing revealed vascular heterogeneity, and temporal regulation of TF expression allowed modulation of arterial and angiogenic iEC phenotypes. In vivo, VOs engrafted into immunodeficient mice, formed perfused vasculature, and promoted revascularization in models of hind limb ischemia and pancreatic islet transplantation. These findings establish a rapid and versatile VO platform with broad potential for vascular modeling, disease studies, and regenerative cell therapy.
3. Antimicrobial peptide CRAMP/LL-37 mediates ferroptosis resistance in cardiomyocytes by inhibiting cathepsin L.
CRAMP/LL-37 protects cardiomyocytes from ferroptosis by inhibiting cathepsin L and preserving PDIA4, with evidence across in vitro systems and a mouse MI model. Enhancing CRAMP signaling or delivering CRAMP peptides reduced myocardial injury and improved function.
Impact: It delineates a tractable ferroptosis control axis (CRAMP–CTSL–PDIA4) in cardiomyocytes and demonstrates therapeutic rescue using an endogenous peptide.
Clinical Implications: CRAMP/LL-37-based interventions could complement reperfusion by limiting ferroptotic injury post-MI; formulation, dosing, and safety will require translational studies.
Key Findings
- CRAMP levels decreased in infarcted myocardium and in cardiomyocytes exposed to ferroptosis inducers.
- CRAMP overexpression or LL-37 pretreatment mitigated ferroptosis, whereas CRAMP knockdown exacerbated cell death.
- CRAMP antagonized cathepsin L activity; elevated CTSL reduced PDIA4, while PDIA4 overexpression inhibited CTSL-induced ferroptosis and its knockdown abrogated CRAMP protection.
- In vivo CRAMP overexpression or peptide administration reduced myocardial injury and improved cardiac function in mouse MI.
Methodological Strengths
- Integrated in vitro gain- and loss-of-function with in vivo mouse MI validation
- Mechanistic mapping of a CTSL–PDIA4 axis downstream of CRAMP with functional rescue by peptide therapy
Limitations
- Lack of human tissue or clinical data; dosing, delivery route, and off-target effects of LL-37 not explored
- Temporal window and durability of anti-ferroptotic protection after MI require further study
Future Directions: Validate the CRAMP–CTSL–PDIA4 axis in human cardiomyocytes/biopsies, optimize peptide delivery, and test efficacy and safety in large-animal MI models.
Ferroptosis is an important cause of cardiomyocyte loss and cardiac dysfunction. Cathelicidin-related antimicrobial peptide (CRAMP) is an endogenous polypeptide that regulates oxidative stress in the body and is involved in ferroptosis. However, its specific role and mechanism in ferroptosis are unclear. To analyze the role of CRAMP in ferroptosis, we first analyzed its expression in infarcted myocardial tissues, and verified its role in ferroptosis in vitro through overexpression and knock-down techniques. The activity and expression of cathepsin L (CTSL) and its effect on ferroptosis were analyzed to verify whether CTSL participated in ferroptosis as a downstream of CRAMP. Protein disulfide isomerase family A member 4 (PDIA4) was screened as an interacting protein of CTSL by using the database, and the role of PDIA4 in ferroptosis was analyzed by gene knockdown and overexpression. Finally, the regulatory mechanism of CRAMP in ferroptosis was verified in vivo by mouse myocardial infarction model. CRAMP levels were reduced in both infarcted cardiac tissues and cardiomyocytes exposed to ferroptosis inducers. The overexpression of CRAMP or pretreatment of LL-37 alleviated cardiomyocyte ferroptosis, whereas CRAMP knockdown exacerbated cell death. Under ferroptotic stress, the expression of CTSL was elevated. CRAMP inhibited ferroptosis by antagonizing the CTSL activity. Abnormal increase in CTSL activity and levels caused PDIA4 to decrease. Overexpression of PDIA4 inhibited ferroptosis induced by CTSL, while knocking down PDIA4 counteracted the protection of CRAMP. In vivo, both CRAMP overexpression and administration of CRAMP peptide significantly ameliorated myocardial injury and improved cardiac function. CRAMP increases PDIA4 levels by inhibiting the activity of CTSL and antagonizes ferroptosis in cardiomyocytes. Targeting CRAMP offers innovative therapeutic strategies and insights for the prevention and management of myocardial injury.