HINT1 (Histidine Triad Nucleotide-Binding Protein 1) Attenuates Cardiac Hypertrophy Via Suppressing HOXA5 (Homeobox A5) Expression

The Role of the MAPK Signaling Pathway in Cardiovascular Disease: Pathophysiological Mechanisms and Clinical Therapy

Cardiovascular disease (CVD) is a serious global health issue with high mortality rates worldwide. Despite the numerous advancements in the study of CVD pathogenesis in recent years, further summarization and elaboration of specific molecular pathways are required. An extensive body of research has been conducted to elucidate the association between the MAPK signaling pathway, which is present in all eukaryotic organisms, and the pathogenesis of cardiovascular disease. This review aims to provide a comprehensive summary of the research conducted on MAPK and CVD over the past five years. The primary focus is on four specific diseases: heart failure, atherosclerosis, myocardial ischemia-reperfusion injury, and cardiac hypertrophy. The review will also address the pathophysiological mechanisms of MAPK in cardiovascular diseases, with the objective of proposing novel clinical treatment strategies for CVD.

TRIM26 exacerbates pathological cardiac hypertrophy by activating TAK1

Pathological myocardial hypertrophy can induce heart failure with high mortality, it is necessary to explore its pathogenesis. Tripartite motif-containing 26 (TRIM26) belongs to the multidomain E3 ubiquitin ligase family. We observed increased expression of TRIM26 in the myocardium of C57BL/6 mice subjected to transverse aortic constriction (TAC) surgery and neonatal rat cardiomyocytes (NRCMs) treated with phenylephrine (PE). To evaluate the role of TRIM26 in pathological cardiac hypertrophy, we generated Trim26 global knockout mice and Trim26 overexpression adenoviruses. Mice with Trim26 deletion showed alleviated cardiomyocyte enlargement, inflammation, fibrosis, and cardiac dysfunction after TAC surgery. In PE-treated NRCMs, Trim26 overexpression promoted cardiomyocyte enlargement and inflammation, while Trim26 knockdown had the opposite effects. RNA sequencing and molecular biology methodologies were performed to identify targets conducive to TRIM26 function. The results showed that TRIM26 activated the transforming growth factor-beta activated kinase 1 (TAK1)-c-Jun N-terminal kinase/p38 signaling pathway in response to hypertrophic stress. Moreover, inhibition of TAK1 activation can reverse the promotion effect of TRIM26 overexpression on cardiomyocyte hypertrophy induced by PE stimulation in vitro. Our study demonstrated that TRIM26 plays an active role in pathological cardiac hypertrophy, and the TRIM26-TAK1 pathway may represent a therapeutic target for treating pathological cardiac hypertrophy and heart failure.

ANK Deficiency-Mediated Cytosolic Citrate Accumulation Promotes Aortic Aneurysm

BACKGROUND

Disturbed metabolism and transport of citrate play significant roles in various pathologies. However, vascular citrate regulation and its potential role in aortic aneurysm (AA) development remain poorly understood.

METHODS

Untargeted metabolomics by mass spectrometry was applied to identify upregulated metabolites of the tricarboxylic acid cycle in AA tissues of mice. To investigate the role of citrate and its transporter ANK (progressive ankylosis protein) in AA development, vascular smooth muscle cell (VSMC)-specific Ank-knockout mice were used in both Ang II (angiotensin II)- and CaPO4-induced AA models.

RESULTS

Citrate was abnormally increased in both human and murine aneurysmal tissues, which was associated with downregulation of ANK, a citrate membrane transporter, in VSMCs. The knockout of Ank in VSMCs promoted AA formation in both Ang II- and CaPO4-induced AA models, while its overexpression inhibited the development of aneurysms. Mechanistically, ANK deficiency in VSMCs caused abnormal cytosolic accumulation of citrate, which was cleaved into acetyl coenzyme A and thus intensified histone acetylation at H3K23, H3K27, and H4K5. Cleavage under target and tagmentation analysis further identified that ANK deficiency-induced histone acetylation activated the transcription of inflammatory genes in VSMCs and thus promoted a citrate-related proinflammatory VSMC phenotype during aneurysm diseases. Accordingly, suppressing citrate cleavage to acetyl coenzyme A downregulated inflammatory gene expression in VSMCs and restricted ANK deficiency-aggravated AA formation.

CONCLUSIONS

Our studies define the pathogenic role of ANK deficiency-induced cytosolic citrate accumulation in AA pathogenesis and an undescribed citrate-related proinflammatory VSMC phenotype. Targeting ANK-mediated citrate transport may emerge as a novel diagnostic and therapeutic strategy in AA.

Epigenetic Study of Cohort of Monozygotic Twins With Hypertrophic Cardiomyopathy Due to MYBPC3 (Cardiac Myosin-Binding Protein C)

BACKGROUND

Hypertrophic cardiomyopathy is an autosomal dominant cardiac disease. The mechanisms that determine its variable expressivity are poorly understood. Epigenetics could play a crucial role in bridging the gap between genotype and phenotype by orchestrating the interplay between the environment and the genome regulation. In this study we aimed to establish a possible correlation between the peripheral blood DNA methylation patterns and left ventricular hypertrophy severity in patients with hypertrophic cardiomyopathy, evaluating the potential impact of lifestyle variables and providing a biological context to the observed changes.

METHODS AND RESULTS

Methylation data were obtained from peripheral blood samples (Infinium MethylationEPIC BeadChip arrays). We employed multiple pair-matched models to extract genomic positions whose methylation correlates with the degree of left ventricular hypertrophy in 3 monozygotic twin pairs carrying the same founder pathogenic variant (MYBPC3 p.Gly263Ter). This model enables the isolation of the environmental influence, beyond age, on DNA methylation changes by removing the genetic background. Our results revealed a more anxious personality among more severely affected individuals. We identified 56 differentially methylated positions that exhibited moderate, proportional changes in methylation associated with left ventricular hypertrophy. These differentially methylated positions were enriched in regions regulated by repressor histone marks and tended to cluster at genes involved in left ventricular hypertrophy development, such as HOXA5, TRPC3, UCN3, or PLSCR2, suggesting that changes in peripheral blood may reflect myocardial alterations.

CONCLUSIONS

We present a unique pair-matched model, based on 3 monozygotic twin pairs carrying the same founder pathogenic variant and different phenotypes. This study provides further evidence of the pivotal role of epigenetics in hypertrophic cardiomyopathy variable expressivity.

Rectifying METTL4-Mediated N6-Methyladenine Excess in Mitochondrial DNA Alleviates Heart Failure

BACKGROUND

Myocardial mitochondrial dysfunction underpins the pathogenesis of heart failure (HF), yet therapeutic options to restore myocardial mitochondrial function are scarce. Epigenetic modifications of mitochondrial DNA (mtDNA), such as methylation, play a pivotal role in modulating mitochondrial homeostasis. However, their involvement in HF remains unclear.

METHODS

Experimental HF models were established through continuous angiotensin II and phenylephrine (AngII/PE) infusion or prolonged myocardial ischemia/reperfusion injury. The landscape of N6-methyladenine (6mA) methylation within failing cardiomyocyte mtDNA was characterized using high-resolution mass spectrometry and methylated DNA immunoprecipitation sequencing. A tamoxifen-inducible cardiomyocyte-specific Mettl4 knockout mouse model and adeno-associated virus vectors designed for cardiomyocyte-targeted manipulation of METTL4 (methyltransferase-like protein 4) expression were used to ascertain the role of mtDNA 6mA and its methyltransferase METTL4 in HF.

RESULTS

METTL4 was predominantly localized within adult cardiomyocyte mitochondria. 6mA modifications were significantly more abundant in mtDNA than in nuclear DNA. Postnatal cardiomyocyte maturation presented with a reduction in 6mA levels within mtDNA, coinciding with a decrease in METTL4 expression. However, an increase in both mtDNA 6mA level and METTL4 expression was observed in failing adult cardiomyocytes, suggesting a shift toward a neonatal-like state. METTL4 preferentially targeted mtDNA promoter regions, which resulted in interference with transcription initiation complex assembly, mtDNA transcriptional stalling, and ultimately mitochondrial dysfunction. Amplifying cardiomyocyte mtDNA 6mA through METTL4 overexpression led to spontaneous mitochondrial dysfunction and HF phenotypes. The transcription factor p53 was identified as a direct regulator of METTL4 transcription in response to HF-provoking stress, thereby revealing a stress-responsive mechanism that controls METTL4 expression and mtDNA 6mA. Cardiomyocyte-specific deletion of the Mettl4 gene eliminated mtDNA 6mA excess, preserved mitochondrial function, and mitigated the development of HF upon continuous infusion of AngII/PE. In addition, specific silencing of METTL4 in cardiomyocytes restored mitochondrial function and offered therapeutic relief in mice with preexisting HF, irrespective of whether the condition was induced by AngII/PE infusion or myocardial ischemia/reperfusion injury.

CONCLUSIONS

Our findings identify a pivotal role of cardiomyocyte mtDNA 6mA and the corresponding methyltransferase, METTL4, in the pathogenesis of mitochondrial dysfunction and HF. Targeted suppression of METTL4 to rectify mtDNA 6mA excess emerges as a promising strategy for developing mitochondria-focused HF interventions.

Dissecting the dynamic cellular transcriptional atlas of adult teleost testis development throughout the annual reproductive cycle

Teleost testis development during the annual cycle involves dramatic changes in cellular compositions and molecular events. In this study, the testicular cells derived from adult black rockfish at distinct stages - regressed, regenerating and differentiating - were meticulously dissected via single-cell transcriptome sequencing. A continuous developmental trajectory of spermatogenic cells, from spermatogonia to spermatids, was delineated, elucidating the molecular events involved in spermatogenesis. Subsequently, the dynamic regulation of gene expression associated with spermatogonia proliferation and differentiation was observed across spermatogonia subgroups and developmental stages. A bioenergetic transition from glycolysis to mitochondrial respiration of spermatogonia during the annual developmental cycle was demonstrated, and a deeper level of heterogeneity and molecular characteristics was revealed by re-clustering analysis. Additionally, the developmental trajectory of Sertoli cells was delineated, alongside the divergence of Leydig cells and macrophages. Moreover, the interaction network between testicular micro-environment somatic cells and spermatogenic cells was established. Overall, our study provides detailed information on both germ and somatic cells within teleost testes during the annual reproductive cycle, which lays the foundation for spermatogenesis regulation and germplasm preservation of endangered species.

Leukocyte Ig-like receptor B4 (Lilrb4a) alleviates cardiac dysfunction and isoproterenol-induced arrhythmogenic remodeling associated with cardiac fibrosis and inflammation

BACKGROUND

Heart failure is usually accompanied by activation of the sympathetic nerve, and excessive activation of the sympathetic nerve promotes cardiac remodeling and cardiac dysfunction. In the isoproterenol (ISO)-induced animal model, it is often accompanied by myocardial hypertrophy, fibrosis, and inflammation. Leukocyte immunoglobulin-like receptor B4a (Lilrb4a), an immunosuppressive regulatory receptor, plays a vital role in cardiovascular disease. However, the effect of Lilrb4a on ventricular arrhythmia in an ISO-induced mouse model remains unclear.

OBJECTIVE

The purpose of this study was to explore the role and molecular mechanism of Lilrb4a in ISO-induced arrhythmogenic remodeling.

METHODS

Lilrb4a knockout mice and Lilrb4a overexpression mice were infused with ISO (15 mg/kg per 24 hours, 4 weeks). Echocardiography and histology evaluations of myocardial hypertrophy and cardiac structural remodeling were conducted. Surface electrocardiography and electrophysiologic examination were used to evaluate cardiac electrical remodeling and susceptibility to ventricular arrhythmias. Quantitative reverse transcriptase-polymerase chain reaction analysis and Western blotting were used to detect the expression levels of ion channel proteins and signal pathway proteins.

RESULTS

The results discovered that ISO induced cardiac hypertrophy, fibrosis, and inflammation and led to electrical remodeling and the occurrence of ventricular arrhythmias. Lilrb4a alleviated cardiac structural and electrical remodeling and protected against the occurrence of ventricular arrhythmias in ISO-induced mice by gain-of-function or loss-of-function approaches. The mechanism is that Lilrb4a inhibited NF-κB signaling and MAPK signaling activation mediated by transforming growth factor kinase 1.

CONCLUSION

Lilrb4a alleviates cardiac dysfunction and ISO-induced arrhythmogenic remodeling associated with cardiac fibrosis and inflammation through the regulation of NF-κB signaling and MAPK signaling activation.

Regulatory T Cells in Pathological Cardiac Hypertrophy: Mechanisms and Therapeutic Potential

BACKGROUND

Pathological cardiac hypertrophy is linked to immune-inflammatory injury, and regulatory T cells (Tregs) play a crucial role in suppressing immune-inflammatory responses. However, the precise role of Tregs in pathological cardiac hypertrophy remains unclear.

OBJECTIVE

To summarize the current knowledge on the role and mechanisms of Tregs in pathological cardiac hypertrophy and explore their perspectives and challenges as a new therapeutic approach.

RESULTS

Treg cells may play an important protective role in pressure overload (hypertension, aortic stenosis), myocardial infarction, metabolic disorders (diabetes, obesity), acute myocarditis, cardiomyopathy (hypertrophic cardiomyopathy, storage diseases), and chronic obstructive pulmonary disease-related pathological cardiac hypertrophy. Although some challenges remain, the safety and efficacy of Treg-based therapies have been confirmed in some clinical trials, and engineered antigen-specific Treg cells may have better clinical application prospects due to stronger immunosuppressive function and stability.

CONCLUSION

Targeting the immune-inflammatory response via Treg-based therapies might provide a promising and novel future approach to the prevention and treatment of pathological cardiac hypertrophy.

The m7G Methyltransferase Mettl1 Drives Cardiac Hypertrophy by Regulating SRSF9-Mediated Splicing of NFATc4

Cardiac hypertrophy is a key factor driving heart failure (HF), yet its pathogenesis remains incompletely elucidated. Mettl1-catalyzed RNA N7-methylguanosine (m7G) modification has been implicated in ischemic cardiac injury and fibrosis. This study aims to elucidate the role of Mettl1 and the mechanism underlying non-ischemic cardiac hypertrophy and HF. It is found that Mettl1 is upregulated in human failing hearts and hypertrophic murine hearts following transverse aortic constriction (TAC) and Angiotensin II (Ang II) infusion. YY1 acts as a transcriptional factor for Mettl1 during cardiac hypertrophy. Mettl1 knockout alleviates cardiac hypertrophy and dysfunction upon pressure overload from TAC or Ang II stimulation. Conversely, cardiac-specific overexpression of Mettl1 results in cardiac remodeling. Mechanically, Mettl1 increases SRSF9 expression by inducing m7G modification of SRSF9 mRNA, facilitating alternative splicing and stabilization of NFATc4, thereby promoting cardiac hypertrophy. Moreover, the knockdown of SRSF9 protects against TAC- or Mettl1-induced cardiac hypertrophic phenotypes in vivo and in vitro. The study identifies Mettl1 as a crucial regulator of cardiac hypertrophy, providing a novel therapeutic target for HF.

Construction of a Near-Infrared Fluorescent Probe for Dynamic Monitoring and Early Diagnosis of Heart Failure

Cardiac hypertrophy characterized by abnormal cardiomyocyte viscosity is a typical sign of heart failure (HF) with vital importance for early diagnosis. However, current biochemical and imaging diagnostic methods are unable to detect this subclinical manifestation. In this work, we developed a series of NIR-I fluorescence probes for detecting myocardial viscosity based on the pyridazinone scaffold. The probes showed weak fluorescence due to free intramolecular rotation under low-viscosity conditions, while they displayed strong fluorescence with limited intramolecular rotation in response to a high-viscosity environment. Among them, CarVis2 exhibited higher stability and photobleaching resistance than commercial dyes. Its specific response to viscosity was not influenced by the pH and biological species. Furthermore, CarVis2 showed rapid and accurate responses to the viscosity of isoproterenol (ISO)-treated H9C2 cardiomyocytes with good biocompatibility. More importantly, CarVis2 demonstrated excellent sensitivity in monitoring myocardial viscosity variation in HF mice in vivo, potentially enabling earlier noninvasive identification of myocardial abnormalities compared to traditional clinical imaging and biomarkers. These findings revealed that CarVis2 can serve as a powerful tool to monitor myocardial viscosity, providing the potential to advance insights into a pathophysiological mechanism and offering a new reference strategy for early visual diagnosis of HF.

S-Nitrosylation of Septin2 Exacerbates Aortic Aneurysm and Dissection by Coupling the TIAM1-RAC1 Axis in Macrophages

BACKGROUND

S-Nitrosylation (SNO), a prototypic redox-based posttranslational modification, is involved in cardiovascular disease. Aortic aneurysm and dissection are high-risk cardiovascular diseases without an effective cure. The aim of this study was to determine the role of SNO of Septin2 in macrophages in aortic aneurysm and dissection.

METHODS

Biotin-switch assay combined with liquid chromatography-tandem mass spectrometry was performed to identify the S-nitrosylated proteins in aortic tissue from both patients undergoing surgery for aortic dissection and Apoe-/- mice infused with angiotensin II. Angiotensin II-induced aortic aneurysm model and β-aminopropionitrile-induced aortic aneurysm and dissection model were used to determine the role of SNO of Septin2 (SNO-Septin2) in aortic aneurysm and dissection development. RNA-sequencing analysis was performed to recapitulate possible changes in the transcriptome profile of SNO-Septin2 in macrophages in aortic aneurysm and dissection. Liquid chromatography-tandem mass spectrometry and coimmunoprecipitation were used to uncover the TIAM1-RAC1 (Ras-related C3 botulinum toxin substrate 1) axis as the downstream target of SNO-Septin2. Both R-Ketorolac and NSC23766 treatments were used to inhibit the TIAM1-RAC1 axis.

RESULTS

Septin2 was identified S-nitrosylated at cysteine 111 (Cys111) in both aortic tissue from patients undergoing surgery for aortic dissection and Apoe-/- mice infused with Angiotensin II. SNO-Septin2 was demonstrated driving the development of aortic aneurysm and dissection. By RNA-sequencing, SNO-Septin2 in macrophages was demonstrated to exacerbate vascular inflammation and extracellular matrix degradation in aortic aneurysm. Next, TIAM1 (T lymphoma invasion and metastasis-inducing protein 1) was identified as a SNO-Septin2 target protein. Mechanistically, compared with unmodified Septin2, SNO-Septin2 reduced its interaction with TIAM1 and activated the TIAM1-RAC1 axis and consequent nuclear factor-κB signaling pathway, resulting in stronger inflammation and extracellular matrix degradation mediated by macrophages. Consistently, both R-Ketorolac and NSC23766 treatments protected against aortic aneurysm and dissection by inhibiting the TIAM1-RAC1 axis.

CONCLUSIONS

SNO-Septin2 drives aortic aneurysm and dissection through coupling the TIAM1-RAC1 axis in macrophages and activating the nuclear factor-κB signaling pathway-dependent inflammation and extracellular matrix degradation. Pharmacological blockade of RAC1 by R-Ketorolac or NSC23766 may therefore represent a potential treatment against aortic aneurysm and dissection.

Involvement of E3 ubiquitin ligase NEDD4-mediated YY1 ubiquitination in alleviating idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic and lethal lung disease characterized by progressive lung scarring. This study aims to elucidate the role of the E3 ubiquitin ligase NEDD4 in the ubiquitination of YY1 and its subsequent impact on TAB1 transcription, revealing a possible molecular mechanism in the development of IPF. Through bioinformatics analysis and both in vitro and in vivo experiments, we observed differential expression levels of NEDD4 and YY1 between normal and IPF samples, identifying NEDD4 as an upstream E3 ubiquitin ligase of YY1. Furthermore, binding sites for the transcription factor YY1 on the promoter region of TAB1 were discovered, indicating a direct interaction. In vitro experiments using HEPF cells showed that NEDD4 mediates the ubiquitination and degradation of YY1, leading to suppressed TAB1 transcription, thereby inhibiting cell proliferation and fibrogenesis. These findings were corroborated by in vivo experiments in an IPF mouse model, where the ubiquitination pathway facilitated by NEDD4 attenuated IPF progression through the downregulation of YY1 and TAB1 transcription. These results suggest that NEDD4 plays a crucial role in the development of IPF by modulating YY1 ubiquitination and TAB1 transcription, providing new insights into potential therapeutic targets for treating IPF.

Role of Vasoactive Hormone-Induced Signal Transduction in Cardiac Hypertrophy and Heart Failure

Heart failure is the common concluding pathway for a majority of cardiovascular diseases and is associated with cardiac dysfunction. Since heart failure is invariably preceded by adaptive or maladaptive cardiac hypertrophy, several biochemical mechanisms have been proposed to explain the development of cardiac hypertrophy and progression to heart failure. One of these includes the activation of different neuroendocrine systems for elevating the circulating levels of different vasoactive hormones such as catecholamines, angiotensin II, vasopressin, serotonin and endothelins. All these hormones are released in the circulation and stimulate different signal transduction systems by acting on their respective receptors on the cell membrane to promote protein synthesis in cardiomyocytes and induce cardiac hypertrophy. The elevated levels of these vasoactive hormones induce hemodynamic overload, increase ventricular wall tension, increase protein synthesis and the occurrence of cardiac remodeling. In addition, there occurs an increase in proinflammatory cytokines and collagen synthesis for the induction of myocardial fibrosis and the transition of adaptive to maladaptive hypertrophy. The prolonged exposure of the hypertrophied heart to these vasoactive hormones has been reported to result in the oxidation of catecholamines and serotonin via monoamine oxidase as well as the activation of NADPH oxidase via angiotensin II and endothelins to promote oxidative stress. The development of oxidative stress produces subcellular defects, Ca2+-handling abnormalities, mitochondrial Ca2+-overload and cardiac dysfunction by activating different proteases and depressing cardiac gene expression, in addition to destabilizing the extracellular matrix upon activating some metalloproteinases. These observations support the view that elevated levels of various vasoactive hormones, by producing hemodynamic overload and activating their respective receptor-mediated signal transduction mechanisms, induce cardiac hypertrophy. Furthermore, the occurrence of oxidative stress due to the prolonged exposure of the hypertrophied heart to these hormones plays a critical role in the progression of heart failure.

Deficiency of Transcription Factor Sp1 Contributes to Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the most prevalent monogenic heart disorder. However, the pathogenesis of HCM, especially its nongenetic mechanisms, remains largely unclear. Transcription factors are known to be involved in various biological processes including cell growth. We hypothesized that SP1 (specificity protein 1), the first purified TF in mammals, plays a role in the cardiomyocyte growth and cardiac hypertrophy of HCM.

METHODS

Cardiac-specific conditional knockout of Sp1 mice were constructed to investigate the role of SP1 in the heart. The echocardiography, histochemical experiment, and transmission electron microscope were performed to analyze the cardiac phenotypes of cardiac-specific conditional knockout of Sp1 mice. RNA sequencing, chromatin immunoprecipitation sequencing, and adeno-associated virus experiments in vivo were performed to explore the downstream molecules of SP1. To examine the therapeutic effect of SP1 on HCM, an SP1 overexpression vector was constructed and injected into the mutant allele of Myh6 R404Q/+ (Myh6 c. 1211C>T) HCM mice. The human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from a patient with HCM were used to detect the potential therapeutic effects of SP1 in human HCM.

RESULTS

The cardiac-specific conditional knockout of Sp1 mice developed a typical HCM phenotype, displaying overt myocardial hypertrophy, interstitial fibrosis, and disordered myofilament. In addition, Sp1 knockdown dramatically increased the cell area of hiPSC-CMs and caused intracellular myofibrillar disorganization, which was similar to the hypertrophic cardiomyocytes of HCM. Mechanistically, Tuft1 was identified as the key target gene of SP1. The hypertrophic phenotypes induced by Sp1 knockdown in both hiPSC-CMs and mice could be rescued by TUFT1 (tuftelin 1) overexpression. Furthermore, SP1 overexpression suppressed the development of HCM in the mutant allele of Myh6 R404Q/+ mice and also reversed the hypertrophic phenotype of HCM hiPSC-CMs.

CONCLUSIONS

Our study demonstrates that SP1 deficiency leads to HCM. SP1 overexpression exhibits significant therapeutic effects on both HCM mice and HCM hiPSC-CMs, suggesting that SP1 could be a potential intervention target for HCM.

Deciphering the emerging landscape of HOX genes in cardiovascular biology, atherosclerosis and beyond (Review)

Atherosclerosis, a dominant driving force underlying multiple cardiovascular events, is an intertwined and chronic inflammatory disease characterized by lipid deposition in the arterial wall, which leads to diverse cardiovascular problems. Despite unprecedented advances in understanding the pathogenesis of atherosclerosis and the substantial decline in cardiovascular mortality, atherosclerotic cardiovascular disease remains a global public health issue. Understanding the molecular landscape of atherosclerosis is imperative in the field of molecular cardiology. Recently, compelling evidence has shown that an important family of homeobox (HOX) genes endows causality in orchestrating the interplay between various cardiovascular biological processes and atherosclerosis. Despite seemingly scratching the surface, such insight into the realization of biology promises to yield extraordinary breakthroughs in ameliorating atherosclerosis. Primarily recapitulated herein are the contributions of HOX in atherosclerosis, including diverse cardiovascular biology, knowledge gaps, remaining challenges and future directions. A snapshot of other cardiovascular biological processes was also provided, including cardiac/vascular development, cardiomyocyte pyroptosis/apoptosis, cardiac fibroblast proliferation and cardiac hypertrophy, which are responsible for cardiovascular disorders. Further in‑depth investigation of HOX promises to provide a potential yet challenging landscape, albeit largely undetermined to date, for partially pinpointing the molecular mechanisms of atherosclerosis. A plethora of new targeted therapies may ultimately emerge against atherosclerosis, which is rapidly underway. However, translational undertakings are crucially important but increasingly challenging and remain an ongoing and monumental conundrum in the field.

Optimized new Shengmai powder ameliorates myocardial fibrosis in rats with heart failure by inhibition of the MAPK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Optimized New Shengmai Powder (ONSMP) is a traditional Chinese medicine (TCM) formula for heart failure treatment. MAPK signaling pathway is the key driver of myocardial fibrosis in heart failure. However, the mechanism of ONSMP on myocardial fibrosis and MAPK signaling pathway remains unclear.

AIM OF THE STUDY

To evaluate the effect of ONSMP against myocardial fibrosis in heart failure and the underlying mechanisms.

MATERIALS AND METHODS

Firstly, UHPLC-Q-Exactive-MS/MS was used to identify the active components in ONSMP. Secondly, a rat model of heart failure was established by ligating the left anterior descending branch of the coronary artery. After four weeks of intragastric administration of ONSMP, we used various classic tests, including echocardiography, exhaustive swimming, cardiopulmonary coefficient, heart failure markers, and cardiac pathological section, to assess the prescription's anti-myocardial fibrosis in heart failure properties. AGEs, Ang Ⅱ, VEGF, CTGF, and TGFβ levels in rat serum were quantified using ELISA. The positive expression of p-ERK1/2 and p-JNK1/2 of rat myocardium was determined immunohistochemical. The protein and mRNA levels of genes involved in the MAPK signaling pathway and myocardial fibrosis were measured using western blotting or real-time PCR.

RESULTS

The main components of ONSMP that regulate the MAPK signaling pathway are isorhamnetin, kaempferol, quercetin, and tanshinone ⅡA. ONSMP ameliorated cardiac function and exercise tolerance and reduced cardiopulmonary coefficient, heart failure marker levels, and myocardial fibrosis in the heart failure rats. In addition, ONSMP diminished the serum MAPK pathway activator levels, positive expression level of p-ERK1/2 and p-JNK1/2, protein and mRNA levels of components of the MAPK signaling pathway in the myocardial tissue of heart failure rat, indicating that it inhibits MAPK signaling pathway.

CONCLUSIONS

ONSMP delayed heart failure by inhibiting myocardial fibrosis via the MAPK signaling pathway.

Upregulation of mitochondrial telomerase reverse transcriptase mediates the preventive effect of physical exercise on pathological cardiac hypertrophy via improving mitochondrial function and inhibiting oxidative stress

Physical exercise is a non-pharmacological intervention that helps prevent pathological cardiac hypertrophy. However, the underlying molecular mechanisms remain unclear. Telomerase reverse transcriptase (TERT) has non-telomeric functions such as protection against mitochondrial dysfunction and oxidative stress, and its myocardial expression is upregulated by physical exercise. Here, we found that physical exercise caused myocardial upregulation of mitochondrial TERT and sustenance during transverse aortic constriction (TAC)-induced cardiac hypertrophy. Overexpression of mitochondrial-targeted TERT (mito-TERT) via adeno-associated virus serotype 9 carrying the TERT-coding sequence fused with N-terminal mitochondrial-targeting sequence improved cardiac function and attenuated cardiac hypertrophy. Mechanistically, mito-TERT ameliorated mitochondrial dysfunction and oxidative stress, which were associated with improving the activity and subunit composition of complex I. Remarkably, the telomerase activator TA-65 also exhibited an antihypertrophic effect. Collectively, our results reveal a significant role for mito-TERT in mediating the antihypertrophic effect of physical exercise and demonstrate that TERT is a potential drug target for treating cardiac hypertrophy.

Extracellular vesicles in cardiovascular diseases: From pathophysiology to diagnosis and therapy

Extracellular vesicles (EVs), encompassing exosomes, microvesicles (MVs), and apoptotic bodies (ABs), are cell-derived heterogeneous nanoparticles with a pivotal role in intercellular communication. EVs are enclosed by a lipid-bilayer membrane to escape enzymatic degradation. EVs contain various functional molecules (e.g., nucleic acids, proteins, lipids and metabolites) which can be transferred from donor cells to recipient cells. EVs provide many advantages including accessibility, modifiability and easy storage, stability, biocompatibility, heterogeneity and they readily penetrate through biological barriers, making EVs ideal and promising candidates for diagnosis/prognosis biomarkers and therapeutic tools. Recently, EVs were implicated in both physiological and pathophysiological settings of cardiovascular system through regulation of cell-cell communication. Numerous studies have reported a role for EVs in the pathophysiological progression of cardiovascular diseases (CVDs) and have evaluated the utility of EVs for the diagnosis/prognosis and therapeutics of CVDs. In this review, we summarize the biology of EVs, evaluate the perceived biological function of EVs in different CVDs along with a consideration of recent progress for the application of EVs in diagnosis/prognosis and therapies of CVDs.

Ergothioneine suppresses hepatic stellate cell activation via promoting Foxa3-dependent potentiation of the Hint1/Smad7 cascade and improves CCl4-induced liver fibrosis in mice

Ergothioneine (EGT) is a bioactive compound derived from certain edible mushrooms. The activation of hepatic stellate cells (HSCs) is critically involved in the etiology of liver fibrosis (LF). Here, we report that in LX-2 HSCs, EGT upregulates the expression of Hint1 and Smad7 and suppresses their activation provoked by TGFβ1. The EGT-triggered inhibition of HSC activation is abolished by knocking down the expression of Hint1. Overexpression of Hint1 increases Smad7 and represses TGFβ1-provoked activation of LX-2 HSCs. In silico predictions unveiled that in the promoter region of the human Hint1 gene, there are two conserved cis-acting elements that have the potential to interact with the transcription factor Foxa3 termed hFBS1 and hFBS2, respectively. The knockdown of Foxa3 obviously declined Hint1 expression at both mRNA and protein levels. Transfection of Foxa3 or EGT treatment increased the activity of the luciferase reporter driven by the Hint1 promoter in an hFBS2-dependent manner. The knockdown of Foxa3 eliminated EGT-mediated upregulation of Hint1 promoter activity. Additionally, EGT triggered the nuclear translocation of Foxa3 without obviously affecting its expression level. Molecular docking analysis showed that EGT has the potential to directly interact with the Foxa3 protein. Moreover, Foxa3 played a critical role in EGT-mediated hepatoprotection. EGT modulated the Foxa3/Hint1/Smad7 signaling in mouse primary HSCs and inhibited their activation. The gavage of EGT considerably relieved CCl4-induced LF in mice. Our data provide new insights into the anti-LF activity of EGT. Mechanistically, EGT triggers the nuclear translocation of Foxa3 in HSCs, which promotes Hint1 transcription and subsequently elevates Smad7.

Transmembrane protein 117 knockdown protects against angiotensin-II-induced cardiac hypertrophy

Mitochondrial dysfunction plays a critical role in the pathogenesis of pathological cardiac hypertrophy. Transmembrane protein 117 modulate mitochondrial membrane potential that may be involved in the regulation of oxidative stress and mitochondrial function. However, its role in the development of angiotensin II (Ang-II)-induced cardiac hypertrophy is unclear. Cardiac-specific TMEM117-knockout and control mice were subjected to cardiac hypertrophy induced by Ang-II infusion. Small-interfering RNAs against TMEM117 or adenovirus-based plasmids encoding TMEM117 were delivered into left ventricles of mice or incubated with neonatal murine ventricular myocytes (NMVMs) before Ang-II stimulation. We found that TMEM117 was upregulated in hypertrophic hearts and cardiomyocytes and TMEM117 deficiency attenuated Ang-II-induced cardiac hypertrophy in vivo. Consistently, the in vitro data demonstrated that Ang-II-induced cardiomyocyte hypertrophy significantly alleviated by TMEM117 knockdown. Conversely, overexpression of TMEM117 exacerbated cardiac hypertrophy and dysfunction. An Ang II-induced increase in cardiac (cardiomyocyte) oxidative stress was alleviated by cardiac-specific knockout (knockdown) of TMEM117 and was worsened by TMEM117 supplementation (overexpression). In addition, TMEM117 knockout decreased endoplasmic reticulum stress induced by Ang-II, which was reversed by TMEM117 supplementation. Furthermore, TMEM117 deficiency mitigated mitochondrial injury in hypertrophic hearts and cardiomyocyte, which was abolished by TMEM117 supplementation (overexpression). Taken together, these findings suggest that upregulation of TMEM117 contributes to the development of cardiac hypertrophy and the downregulation of TMEM117 may be a new therapeutic strategy for the prevention and treatment of cardiac hypertrophy.

PHB2 ameliorates Doxorubicin-induced cardiomyopathy through interaction with NDUFV2 and restoration of mitochondrial complex I function

BACKGROUND

Doxorubicin (DOX) is among the most widely employed antitumor agents, although its clinical applications have been largely hindered by severe cardiotoxicity. Earlier studies described an essential role of mitochondrial injury in the pathogenesis of DOX cardiomyopathy. PHB2 (Prohibitin 2) is perceived as an essential regulator for mitochondrial dynamics and oxidative phosphorylation (OXPHOS) although its involvement in DOX cardiomyopathy remains elusive.

METHODS

To decipher the possible role of PHB2 in DOX cardiomyopathy, tamoxifen-induced cardiac-specific PHB2 conditional knockout mice were generated and subjected to DOX challenge. Cardiac function and mitochondrial profiles were examined. Screening of downstream mediators of PHB2 was performed using proteomic profiling and bioinformatic analysis, and was further verified using co-immunoprecipitation and pulldown assays.

RESULTS

Our data revealed significantly downregulated PHB2 expression in DOX-challenged mouse hearts. PHB2CKO mice were more susceptible to DOX cardiotoxicity compared with PHB2flox/flox mice, as evidenced by more pronounced cardiac atrophy, interstitial fibrosis and decrease in left ventricular ejection fraction and fractional shortening. Mechanistically, PHB2 deficiency resulted in the impairment of mitochondrial bioenergetics and oxidative phosphorylation in DOX cardiotoxicity. Proteomic profiling and interactome analyses revealed that PHB2 interacted with NDUFV2 (NADH-ubiquinone oxidoreductase core subunit V2), a key subunit of mitochondrial respiratory Complex I to mediate regulatory property of PHB2 on mitochondrial metabolism. PHB2 governed the expression of NDUFV2 by promoting its stabilization, while PHB2 deficiency significantly downregulated NDUFV2 in DOX-challenged hearts. Cardiac overexpression of PHB2 alleviated mitochondrial defects in DOX cardiomyopathy both in vivo and in vitro.

CONCLUSIONS

Our study defined a novel role for PHB2 in mitochondrial dynamics and energetic metabolism through interacting with NDUFV2 in DOX-challenged hearts. Forced overexpression of PHB2 may be considered a promising therapeutic approach for patients with DOX cardiomyopathy.

Mitochondrial GSNOR Alleviates Cardiac Dysfunction via ANT1 Denitrosylation

BACKGROUND

The cardiac-protective role of GSNOR (S-nitrosoglutathione reductase) in the cytoplasm, as a denitrosylase enzyme of S-nitrosylation, has been reported in cardiac remodeling, but whether GSNOR is localized in other organelles and exerts novel effects remains unknown. We aimed to elucidate the effects of mitochondrial GSNOR, a novel subcellular localization of GSNOR, on cardiac remodeling and heart failure (HF).

METHODS

GSNOR subcellular localization was observed by cellular fractionation assay, immunofluorescent staining, and colloidal gold particle staining. Overexpression of GSNOR in mitochondria was achieved by mitochondria-targeting sequence-directed adeno-associated virus 9. Cardiac-specific knockout of GSNOR mice was used to examine the role of GSNOR in HF. S-nitrosylation sites of ANT1 (adenine nucleotide translocase 1) were identified using biotin-switch and liquid chromatography-tandem mass spectrometry.

RESULTS

GSNOR expression was suppressed in cardiac tissues of patients with HF. Consistently, cardiac-specific knockout mice showed aggravated pathological remodeling induced by transverse aortic constriction. We found that GSNOR is also localized in mitochondria. In the angiotensin II-induced hypertrophic cardiomyocytes, mitochondrial GSNOR levels significantly decreased along with mitochondrial functional impairment. Restoration of mitochondrial GSNOR levels in cardiac-specific knockout mice significantly improved mitochondrial function and cardiac performance in transverse aortic constriction-induced HF mice. Mechanistically, we identified ANT1 as a direct target of GSNOR. A decrease in mitochondrial GSNOR under HF leads to an elevation of S-nitrosylation ANT1 at cysteine 160 (C160). In accordance with these findings, overexpression of either mitochondrial GSNOR or ANT1 C160A, non-nitrosylated mutant, significantly improved mitochondrial function, maintained the mitochondrial membrane potential, and upregulated mitophagy.

CONCLUSIONS

We identified a novel species of GSNOR localized in mitochondria and found mitochondrial GSNOR plays an essential role in maintaining mitochondrial homeostasis through ANT1 denitrosylation, which provides a potential novel therapeutic target for HF.

Dexmedetomidine alleviates propofol-induced pyroptosis of hippocampal neurons through NLRP3 inflammasome pathway

Propofol is neurotoxic to trigger neuronal pyroptosis and dexmedetomidine possesses the ability to suppress proptosis. This study expounded on the protective functions of dexmedetomidine on propofol-induced pyroptosis of primary hippocampal neurons via NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome pathway. At first, primary hippocampal neurons underwent separation and identification and were treated with different concentrations of propofol (1, 10, and 100 μM). The toxicity of propofol in the neurons was evaluated. Prior to propofol treatment, the neurons were treated with different concentrations of dexmedetomidine (0.01, 0.1, 1, 5, and 10 μM). The viability of neurons with different treatments was detected. The mRNA expressions of homeobox A5 (HOXA5) and NLRP3 were identified. The protein levels of intracellular HOXA5, NLRP3, the N-terminal fragment of gasdermin D (GSDMD-N), and cleaved-caspase-1 and the concentrations of interleukin (IL)-1β and IL-18 were examined. Subsequently, the binding of HOXA5 to the NLRP3 promoter was detected. Joint experiments were conducted with pcDNA3.1-HOXA5 or pcDNA3.1-NLRP3 in dexmedetomidine-treated neurons. Dexmedetomidine pretreatment attenuated propofol-induced pyroptosis of hippocampal neurons, increased cell viability, and repressed NLRP3, GSDMD-N, and cleaved-caspase-1 protein levels and IL-1β and IL-18 concentrations. Dexmedetomidine pretreatment inhibited intracellular HOXA5 expression, and HOXA5 bound to the NLRP3 promoter region to promote NLRP3 expression. Overexpressing HOXA5 or NLRP3 reversed anti-pyroptosis role of dexmedetomidine pretreatment in hippocampal neurons. Dexmedetomidine pretreatment suppressed NLRP3 expression by downregulating HOXA5 expression, inhibiting propofol-induced pyroptosis in primary hippocampal neurons.

Homeobox A9 is a novel mediator of vascular smooth muscle cell phenotypic switching and proliferation by regulating methyl-CpG binding protein 2

Aberrant proliferation and phenotypic switching of vascular smooth muscle cells (VSMCs) are considered to be the main pathological processes of atherosclerotic plaque formation. Methyl-CpG binding protein 2 (MECP2) affects cell differentiation via modulating VSMC-specific gene expression and acts as a driver for the development of atherosclerosis (AS). Here, we aimed to elucidate (Rafieian-Kopaei et al., 2014 [1]) the role of homeobox A9 (HOXA9) on aberrant VSMCs upon injury or AS, and (Rana et al., 2021 [2]) whether HOXA9-mediated VSMC injury was associated with MECP2. Adeno-associated virus serotype 8-mediated knockdown of HOXA9 rescued aortic pathological injury of apolipoprotein E-deficient (ApoE^-/-) mice fed a high-fat diet (HFD), characterized by the reduction of lipid accumulation and foam cell formation. Further in vitro evidence suggested that proliferation and migration of primary mouse VSMCs (mVSMCs) stimulated by oxidized low-density lipoprotein (ox-LDL) were inhibited after HOXA9 silencing. In addition, HOXA9 silencing blocked VSMC phenotypic switching from contractile to a pathological synthetic state. HOXA9 overexpression caused opposite alterations in ox-LDL-stimulated mVSMCs. Mechanistically, MECP2 was transcriptionally activated by HOXA9. Forced expression of MECP2 impaired the anti-proliferation, anti-migration, and phenotypic switching abilities of HOXA9 silencing in VSMCs upon ox-LDL stimulation. Collectively, our findings reveal that the role of HOXA9 in pathological vascular remodeling may attribute to transcriptional regulation of MECP2.

Nuclear Receptor NR1D1 Regulates Abdominal Aortic Aneurysm Development by Targeting the Mitochondrial Tricarboxylic Acid Cycle Enzyme Aconitase-2

BACKGROUND

Metabolic disorder increases the risk of abdominal aortic aneurysm (AAA). NRs (nuclear receptors) have been increasingly recognized as important regulators of cell metabolism. However, the role of NRs in AAA development remains largely unknown.

METHODS

We analyzed the expression profile of the NR superfamily in AAA tissues and identified NR1D1 (NR subfamily 1 group D member 1) as the most highly upregulated NR in AAA tissues. To examine the role of NR1D1 in AAA formation, we used vascular smooth muscle cell (VSMC)-specific, endothelial cell-specific, and myeloid cell-specific conditional Nr1d1 knockout mice in both AngII (angiotensin II)- and CaPO4-induced AAA models.

RESULTS

Nr1d1 gene expression exhibited the highest fold change among all 49 NRs in AAA tissues, and NR1D1 protein was upregulated in both human and murine VSMCs from AAA tissues. The knockout of Nr1d1 in VSMCs but not endothelial cells and myeloid cells inhibited AAA formation in both AngII- and CaPO4-induced AAA models. Mechanistic studies identified ACO2 (aconitase-2), a key enzyme of the mitochondrial tricarboxylic acid cycle, as a direct target trans-repressed by NR1D1 that mediated the regulatory effects of NR1D1 on mitochondrial metabolism. NR1D1 deficiency restored the ACO2 dysregulation and mitochondrial dysfunction at the early stage of AngII infusion before AAA formation. Supplementation with αKG (α-ketoglutarate, a downstream metabolite of ACO2) was beneficial in preventing and treating AAA in mice in a manner that required NR1D1 in VSMCs.

CONCLUSIONS

Our data define a previously unrecognized role of nuclear receptor NR1D1 in AAA pathogenesis and an undescribed NR1D1-ACO2 axis involved in regulating mitochondrial metabolism in VSMCs. It is important that our findings suggest αKG supplementation as an effective therapeutic approach for AAA treatment.

Actin-Binding Proteins in Cardiac Hypertrophy

The heart reacts to a large number of pathological stimuli through cardiac hypertrophy, which finally can lead to heart failure. However, the molecular mechanisms of cardiac hypertrophy remain elusive. Actin participates in the formation of highly differentiated myofibrils under the regulation of actin-binding proteins (ABPs), which provides a structural basis for the contractile function and morphological change in cardiomyocytes. Previous studies have shown that the functional abnormality of ABPs can contribute to cardiac hypertrophy. Here, we review the function of various actin-binding proteins associated with the development of cardiac hypertrophy, which provides more references for the prevention and treatment of cardiomyopathy.

Aerobic Exercise Prevents Arterial Stiffness and Attenuates Hyperexcitation of Sympathetic Nerves in Perivascular Adipose Tissue of Mice after Transverse Aortic Constriction

We aimed to investigate the efficacy of exercise on preventing arterial stiffness and the potential role of sympathetic nerves within perivascular adipose tissue (PVAT) in pressure-overload-induced heart failure (HF) mice. Eight-week-old male mice were subjected to sham operation (SHAM), transverse aortic constriction-sedentary (TAC-SE), and transverse aortic constriction-exercise (TAC-EX) groups. Six weeks of aerobic exercise training was performed using a treadmill. Arterial stiffness was determined by measuring the elastic modulus. The elastic and collagen fibers of the aorta and sympathetic nerve distribution in PVAT were observed. Circulating noradrenaline (NE), expressions of β3-adrenergic receptor (β3-AR), and adiponectin in PVAT were quantified. During the recovery of cardiac function by aerobic exercise, thoracic aortic collagen elastic modulus (CEM) and collagen fibers were significantly decreased (p < 0.05, TAC-SE vs. TAC-EX), and elastin elastic modulus (EEM) was significantly increased (p < 0.05, TAC-SE vs. TAC-EX). Circulating NE and sympathetic nerve distribution in PVAT were significantly decreased (p < 0.05, TAC-SE vs. TAC-EX). The expression of β3-AR was significantly reduced (p < 0.05, TAC-SE vs. TAC-EX), and adiponectin was significantly increased (p < 0.05, TAC-SE vs. TAC-EX) in PVAT. Regular aerobic exercise can effectively prevent arterial stiffness and extracellular matrix (ECM) remodeling in the developmental course of HF, during which sympathetic innervation and adiponectin within PVAT might be strongly implicated.

A novel mutation in HINT1 gene causes autosomal recessive axonal neuropathy with neuromyotonia, effective treatment with carbamazepine and review of the literature

INTRODUCTION

Autosomal recessive axonal neuropathy with neuromyotonia (ARAN-NM) is a rare disease entity linked to mutations in the histidine triad nucleotide binding protein 1 (HINT1) gene. The diagnosis and treatment of ARAN-NM are challenging. There have been few reports of ARAN-NM in East Asia.

METHODS

A 15-year-old Chinese ARAN-NM patient developed muscle weakness, cramps and atrophy in the lower limbs at the age of 12. Electromyography (EMG) showed motor axonal degeneration and neuromyotonic discharges. Whole exome sequencing was performed. Bioinformatic methods and computational 3D structure modeling were used to analyze the identified variant. According to literature review, carbamazepine was prescribed to the patient.

RESULTS

Genetic tests identified a homozygous mutation c.356G > T (p.R119L) in the HINT1 gene, which has never been reported before according to HGMD database. Several bioinformatic approaches predicted the variant was damaging. Computational 3D modeling indicated the variant changed the structure of HINT1 protein. Notably, we demonstrated the positive effects of carbamazepine in treating muscle stiffness and cramps of ARAN-NM.

DISCUSSION

22 variants have been reported in the HINT1 gene, and we identified a novel c.356G > T (p.R119L) variant. Our study expands the genetic spectrum of ARAN-NM. Moreover, large clinical trials are required to further demonstrate the role of carbamazepine in ARAN-NM.

RNA sequencing reveals novel LncRNA/mRNAs co-expression network associated with puerarin-mediated inhibition of cardiac hypertrophy in mice

Background

Evidence has demonstrated that puerarin is a potential medicine for the treatment of cardiac hypertrophy. However, the precise underlying molecular mechanisms of the protective effect of puerarin are still unclear. Here, we aimed to explore the regulatory mechanisms of lncRNAs/mRNAs co-expression network in a cardiac hypertrophy mouse model after puerarin treatment.

Methods

A mouse model of cardiac hypertrophy was established by transverse aortic constriction (TAC). The echocardiography, tissue staining and western blot were used to examine the protective effect of puerarin. Then RNA sequencing (RNA-seq) was carried out to analyze systematically mRNAs and lncRNAs expression. The target lncRNA were confirmed using qRT-PCR. Moreover, a coding/non-coding gene co-expression network were established to find the interaction of lncRNA and mRNAs. The biological process, cellular component, molecular function and pathways of different expression mRNAs targeted by lncRNA were explored using Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis.

Results

Puerarin exhibited an obvious inhibitory effect in cardiac hypertrophy in TAC model. RNA-seq analysis was performed to investigate the lncRNAs and mRNAs expression patterns of cardiomyocytes in sham and TAC groups treated with or without puerarin. RNA-seq identified that TAC downregulated four lncRNAs, which could be revised by puerarin treatment (|log2 Fold change| > 2 and FDR < 0.05). Among them, expression alterations of lncRNA Airn (antisense of Igf2r non-protein coding RNA) was confirmed by qRT-PCR. Pearson's correlation coefficients of co-expression levels suggested that there was an interactive relationship between Airn and 2,387 mRNAs (r > 0.95 or r < -0.95). Those co-expressed mRNAs were enriched in some important biological processes such as translational initiation, cell proliferation, insulin-like growth factor binding and poly(A) RNA binding. KEGG analyses suggested that those Airn-interacted mRNAs were enriched in endocytosis, signaling pathways regulating pluripotency of stem cells and the Jak-STAT pathway.

Conclusion

Puerarin may exert beneficial effects on cardiac hypertrophy through regulating the lncRNAs/mRNAs co-expression network.

Bone morphogenetic protein 10 alleviates doxorubicin-induced cardiac injury via signal transducer and activator of transcription 3 signaling pathway

Doxorubicin (DOX) has limited antitumor applications owing to its association with life-threatening cardiac injury. Oxidative damage and cardiac apoptosis are crucial in DOX-induced cardiac injury. Bone morphogenetic protein 10 (BMP10) is predominantly distributed in the heart and acts as a cardioprotective factor that preserves cardiac function. However, the role of BMP10 in DOX-induced cardiac injury has not yet been explored. The current study aimed to examine the function and mechanism of action of BMP10 in DOX-induced cardiac injury. An adeno-associated viral system was used for the overexpression or silencing of cardiac-specific BMP10, and subsequently, a single dose of DOX was intraperitoneally injected to induce cardiac injury. Results showed that DOX exposure decreased BMP10 expression in the heart. Cardiac-specific overexpression of BMP10 alleviated the oxidative stress and apoptosis and improved cardiac function. Conversely, cardiac-specific silencing of BMP10 aggravated the redox disorder and apoptosis and worsened the cardiac dysfunction caused by DOX. Exogenous BMP10 supplementation amelioratesd the DOX-induced cardiac contractile dysfunction. Mechanistically, we found that phosphorylation of signal transducer and activator of transcription 3 (STAT3) is reduced in DOX-induced cardiotoxicity, and, BMP10 activated impaired STAT3 via a non-canonical pathway. BMP10 lost its cardioprotective function in cardiomyocyte-specific STAT3 knockout (STAT3-cKO) mice. Based on our findings, we suggested that BMP10 is a potential therapeutic agent against DOX-induced cardiac injury and that the cardioprotective effects of BMP10 are dependent on the activation of STAT3.

Role and Mechanism of PKC-δ for Cardiovascular Disease: Current Status and Perspective

Protein kinase C (PKC) is a protein kinase with important cellular functions. PKC-δ, a member of the novel PKC subfamily, has been well-documented over the years. Activation of PKC-δ plays an important regulatory role in myocardial ischemia/reperfusion (IRI) injury and myocardial fibrosis, and its activity and expression levels can regulate pathological cardiovascular diseases such as atherosclerosis, hypertension, cardiac hypertrophy, and heart failure. This article aims to review the structure and function of PKC-δ, summarize the current research regarding its activation mechanism and its role in cardiovascular disease, and provide novel insight into further research on the role of PKC-δ in cardiovascular diseases.

S-nitrosylation of Hsp90 promotes cardiac hypertrophy in mice through GSK3β signaling

Cardiac hypertrophy, as one of the major predisposing factors for chronic heart failure, lacks effective interventions. Exploring the pathogenesis of cardiac hypertrophy will reveal potential therapeutic targets. S-nitrosylation is a kind of posttranslational modification that occurs at active cysteines of proteins to mediate various cellular processes. We here identified heat shock protein 90 (Hsp90) as a highly S-nitrosylated target in the hearts of rodents with hypertrophy, and the role of Hsp90 in cardiac hypertrophy remains undefined. The S-nitrosylation of Hsp90 (SNO-Hsp90) levels were elevated in angiotensin II (Ang II)- or phenylephrine (PE)-treated neonatal rat cardiomyocytes (NRCMs) in vitro as well as in cardiomyocytes isolated from mice subjected to transverse aortic constriction (TAC) in vivo. We demonstrated that the elevated SNO-Hsp90 levels were mediated by decreased S-nitrosoglutathione reductase (GSNOR) expression during cardiac hypertrophy, and delivery of GSNOR adeno-associated virus expression vectors (AAV9-GSNOR) decreased the SNO-Hsp90 levels to attenuate cardiac hypertrophy. Mass spectrometry analysis revealed that cysteine 589 (Cys589) might be the S-nitrosylation site of Hsp90. Delivery of the mutated AAV9-Hsp90-C589A inhibited SNO-Hsp90 levels and attenuated cardiac hypertrophy. We further revealed that SNO-Hsp90 led to increased interaction of glycogen synthase kinase 3β (GSK3β) and Hsp90, leading to elevated GSK3β phosphorylation and decreased eIF2Bε phosphorylation, thereby aggravating cardiac hypertrophy. Application of GSK3β inhibitor TWS119 abolished the protective effect of Hsp90-C589A mutation in Ang II-treated NRCMs. In conclusion, this study demonstrates a critical role of SNO-Hsp90 in cardiac hypertrophy, which may be of a therapeutic target for cardiac hypertrophy treatment.