Hao Wang

BACKGROUND: The innate immune system plays a pivotal role in orchestrating the response to myocardial infarction (MI), with monocytes and macrophages acting as central mediators of tissue injury and repair. Following MI, a dynamic sequence of inflammatory, anti-inflammatory, and reparative phases unfolds over the course of several days. While timely resolution of inflammation and initiation of reparative programs are critical for favorable cardiac remodeling and improved long-term outcomes, the mechanisms by which recruited monocyte-derived macrophages are instructed within the postinfarct niche to adopt a reparative phenotype remain incompletely understood. METHODS: Human peripheral blood mononuclear cells were isolated from individuals with and without MI for single-cell RNA sequencing analysis. The murine cardiac monocyte-derived macrophage behaviors after MI were characterized by genetic lineage tracing, lineage tracing plus bone marrow transplantation, metabolite profiling, and cell phenotyping approaches. The role of macrophage CCND1 (cyclin D1) in MI-induced adverse remodeling was investigated using macrophage-specific Ccnd1 knockout mice. Epigenetic experiments were conducted to study the mechanisms underlying metabolic reprogramming and macrophage phenotypic transition. The therapeutic efficacy of lentivirus-targeting macrophage CCND1 and its downstream regulator PDK4 (pyruvate dehydrogenase kinase 4) were assessed in vivo using an MI mouse model. RESULTS: We found that CCND1 levels in peripheral blood mononuclear cells, monocytes, and cardiac macrophages from patients with MI were significantly decreased. Both macrophage-specific and monocyte-derived macrophage–specific deletion of CCND1 worsened MI-induced cardiac dysfunction and adverse remodeling, driven by amplified inflammatory responses. Mechanistically, CCND1 directly interacted with PDK4 and facilitated its ubiquitination by recruiting RPL11 (ribosomal protein L11) and mouse double minute 2. Through this axis, CCND1 suppressed PDK4-driven PDH (pyruvate dehydrogenase) phosphorylation, enhanced glucose oxidation, and shifted macrophages toward an anti-inflammatory phenotype. Targeted overexpression of the CCND1-PDK4 binding motif or knockdown of PDK4 in macrophages improved cardiac function and mitigated adverse remodeling after MI, independent of the canonical cell cycle–regulatory role of CCND1. CONCLUSIONS: Our findings identify the CCND1-PDK4 axis as a key regulator of macrophage functional reprogramming toward a reparative phenotype after MI, highlighting it as a potential therapeutic target in postinfarction remodeling.

The adult mammalian heart exhibits a severely limited regenerative capacity, making myocardial injury a major clinical challenge. Enhancing cardiomyocyte proliferation has emerged as a promising strategy for cardiac repair and regeneration. In this study, we identify aldolase C (ALDOC), a key glycolytic enzyme, whose expression progressively declines during postnatal heart development but is reactivated following neonatal myocardial injury. Cardiomyocyte-specific knockdown of ALDOC impairs cardiomyocyte proliferation and inhibits heart regeneration in neonatal mice after apical resection. Conversely, AAV9-mediated ALDOC overexpression markedly enhances cardiac regeneration and functional recovery in adult mice following myocardial infarction. Mechanistically, ALDOC interacts with RNA-binding motif protein 39 (RBM39) and inhibits TRIM25-mediated ubiquitination and degradation of RBM39, thereby activating PI3K/AKT signaling and promoting cardiomyocyte proliferation. In conclusion, ALDOC is a critical regulator of heart regeneration through the RBM39/PI3K/AKT pathway, and targeted activation of ALDOC or RBM39 represents a potential therapeutic strategy for myocardial injury.

Background: Abdominal aortic aneurysm (AAA) is a clinical life‐threatening issue. No pharmacological treatments are currently approved for the prevention and treatment of AAA. Therefore, identifying novel biomarkers and therapeutic targets is crucial for improving AAA management and outcomes. Methods: To identify plasma proteins with potential causal effects on AAA, we integrated genetic evidence from proteome‐wide Mendelian randomization, genetic correlation, and colocalization analysis. The role of identified proteins in AAA was further explored through the phenome‐wide association study and mediation analysis. Multiomics data analysis, including bulk RNA sequencing, single‐cell/single‐nucleus RNA sequencing, and spatial transcriptomics, was employed to characterize the expression patterns of these proteins. Experimental validation was performed using an AAA model in apolipoprotein E‐deficient mice infused with angiotensin II. Druggability analysis was conducted to identify drug candidates, which were tested in preclinical mouse models. Results: CALB2 (calbindin 2) was identified as having a causal effect on AAA and may influence the progression of AAA through the regulation of lipid metabolism. Multiomics analysis revealed that CALB2 is predominantly expressed in the mesothelial cells of adipose tissues. Inhibition of CALB2 in an AAA mouse model alleviated AAA progression. Druggability analysis identified lenalidomide and genistein as potential therapeutic candidates, and experiments confirmed their efficacy in preventing AAA development. Conclusions: This study identifies CALB2 as being associated with an increased risk of AAA and suggests that i might be a novel biomarker and therapeutic molecule for AAA management. Lenalidomide and genistein hold promising potential as treatments for patients with AAA.

NOD-like receptor (NLR) family proteins are implicated in various cardiovascular diseases. However, the precise role of NLRC5, the largest member of this family, in myocardial infarction (MI) remains poorly understood. This study reveals that NLRC5 is upregulated in the hearts of both patients with MI and MI mice. Silencing NLRC5 in cardiomyocytes impairs cardiac repair and functional recovery, while its overexpression enhances these processes. Furthermore, NLRC5 promotes autophagy in cardiomyocytes, and its protective effects are diminished upon autophagy inhibition. Mechanistically, NLRC5 interacts with CAVIN1, facilitating its degradation and subsequent downregulation of CAV1, which in turn increases the expression of the ATG12-ATG5 complex to stimulate autophagy. Conversely, CAV1 overexpression partially suppresses autophagy and attenuates the improvements in cardiac function observed in NLRC5-overexpressing MI hearts. This study highlights the critical regulatory role of NLRC5 in modulating cardiomyocyte autophagy flux, suggesting that NLRC5 activation may represent a promising therapeutic strategy for MI.

Background: The regenerative capacity of the adult mammalian hearts is limited. Numerous studies have explored mechanisms of adult cardiomyocyte cell‐cycle withdrawal. This translational study evaluated the effects and underlying mechanism of rhCHK1 (recombinant human checkpoint kinase 1) on the survival and proliferation of cardiomyocyte and myocardial repair after ischemia/reperfusion injury in swine. Methods and Results: Intramyocardial injection of rhCHK1 protein (1 mg/kg) encapsulated in hydrogel stimulated cardiomyocyte proliferation and reduced cardiac inflammation response at 3 days after ischemia/reperfusion injury, improved cardiac function and attenuated ventricular remodeling, and reduced the infarct area at 28 days after ischemia/reperfusion injury. Mechanistically, multiomics sequencing analysis demonstrated enrichment of glycolysis and mTOR (mammalian target of rapamycin) pathways after rhCHK1 treatment. Co‐Immunoprecipitation (Co‐IP) experiments and protein docking prediction showed that CHK1 (checkpoint kinase 1) directly bound to and activated the Serine 37 (S37) and Tyrosine 105 (Y105) sites of PKM2 (pyruvate kinase isoform M2) to promote metabolic reprogramming. We further constructed plasmids that knocked out different CHK1 and PKM2 amino acid domains and transfected them into Human Embryonic Kidney 293T (HEK293T) cells for CO‐IP experiments. Results showed that the 1–265 domain of CHK1 directly binds to the 157–400 amino acids of PKM2. Furthermore, hiPSC‐CM (human iPS cell‐derived cardiomyocyte) in vitro and in vivo experiments both demonstrated that CHK1 stimulated cardiomyocytes renewal and cardiac repair by activating PKM2 C‐domain‐mediated cardiac metabolic reprogramming. Conclusions: This study demonstrates that the 1–265 amino acid domain of CHK1 binds to the 157–400 domain of PKM2 and activates PKM2‐mediated metabolic reprogramming to promote cardiomyocyte proliferation and myocardial repair after ischemia/reperfusion injury in adult pigs.

Neonatal mice achieve complete cardiac repair through endogenous myocardial regeneration after apical resection (AR), but this capacity is rapidly lost 7 days after birth. As an upstream inhibitor of cyclin-dependent kinase 4/6- (CDK4/6-) mediated cell cycle activity, p16^INK4a is widely involved in regulating tumor and senescence. Given that p16^INK4a had a significant negative regulation on cell proliferation, targeting cardiomyocytes (CMs) to inhibit p16^INK4a seems to be a promising attempt at myocardial regeneration therapy. The p16^INK4a expression was upregulated during perimyocardial regeneration time. Knockdown of p16^INK4a stimulated CM proliferation, while p16^INK4a overexpression had the opposite effect. In addition, p16^INK4a knockdown prolonged the proliferation time window of newborn myocardium. And p16^INK4a overexpression inhibited cell cycle activity and deteriorated myocardial regeneration after AR. The quantitative proteomic analysis showed that p16^INK4a knockdown mediated the cell cycle progression and intervened in energy metabolism homeostasis. Mechanistically, overexpression of p16^INK4a causes abnormal accumulation of reactive oxygen species (ROS) to induce autophagy, while scavenging ROS with N-acetylcysteine can alleviate autophagy and regulate p16^INK4a, CDK4/6, and CyclinD1 in a covering manner. And the effect of inhibiting the proliferation of p16^INK4a-activated CMs was significantly blocked by the CDK4/6 inhibitor Palbociclib. In summary, p16^INK4a regulated CM proliferation progression through CDK4/6 and ROS-related autophagy to jointly affect myocardial regeneration repair. Our study revealed that p16^INK4a might be a potential therapeutic target for myocardial regeneration after injury.

Research on the regenerative capacity of the neonatal heart could open new avenues for the treatment of myocardial infarction (MI). However, the mechanism of cardiac regeneration remains unclear. In the present study, we constructed a mouse model of heart regeneration and then performed transcriptomic and proteomic analyses on them. Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and Gene Set Enrichment Analysis (GSEA) of differentially expressed genes (DEGs) were conducted. Western blot (WB) and qPCR analyses were used to validate the hub genes expression. As a result, gene expression at the mRNA level and protein level is not the same. We identified 3186 DEGs and 42 differentially expressed proteins (DEPs). Through functional analysis of DEGs and DEPs, we speculate that biological processes such as ubiquitination, cell cycle, and oxygen metabolism are involved in heart regeneration. Integrated transcriptomic and proteomic analysis identified 19 hub genes and Ankrd1, Gpx3, and Trim72 were screened out as potential regulators of cardiac regeneration through further expression verification. In conclusion, we combined transcriptomic and proteomic analyses to characterize the molecular features during heart regeneration in neonatal mice. Finally, Ankrd1, Gpx3, and Trim72 were identified as potential targets for heart regeneration therapy.