Trimetazidine attenuates Ischemia/Reperfusion-Induced myocardial ferroptosis by modulating the Sirt3/Nrf2-GSH system and reducing Oxidative/Nitrative stress.

Ferroptosis is a newly defined mode of cellular demise. The increasing investigation supports that ferroptosis is a crucial factor in the complex mechanisms of myocardial ischemia-reperfusion (I/R) injury. Hence, targeting ferroptosis is a novel strategy for treating myocardial injury. Although evidence suggests that trimetazidine (TMZ) is potentially efficacious against myocardial injury, the exact mechanism of this efficacy is yet to be fully elucidated. This study aimed to determine whether TMZ can act as a ferroptosis resistor and affect I/R-mediated myocardial injury. To this end, researchers have constructed in vitro and in vivo models of I/R using H9C2 cardiomyocytes, primary cardiomyocytes, and SD rats. Here, I/R mediated the onset of ferroptosis in vitro and in vivo, as reflected by excessive iron aggregation, GSH depletion, and the increase in lipid peroxidation. TMZ largely reversed this alteration and attenuated cardiomyocyte injury. Mechanistically, we found that TMZ upregulated the expression of Sirt3. Therefore, we used si-Sirt3 and 3-TYP to interfere with Sirt3 action in vitro and in vivo, respectively. Both si-Sirt3 and 3-TYP partly mitigated the inhibitory effect of TMZ on I/R-mediated ferroptosis and upregulated the expression of Nrf2 and its downstream target, GPX4-SLC7A11. These results indicate that TMZ attenuates I/R-mediated ferroptosis by activating the Sirt3-Nrf2/GPX4/SLC7A11 signaling pathway. Our study offers insights into the mechanism underlying the cardioprotective benefits of TMZ and establishes a groundwork for expanding its potential applications.

Comprehensive macro and micro views on immune cells in ischemic heart disease.

Ischemic heart disease (IHD) is a prevalent cardiovascular condition that remains the primary cause of death due to its adverse ventricular remodelling and pathological changes in end-stage heart failure. As a complex pathologic condition, it involves intricate regulatory processes at the cellular and molecular levels. The immune system and cardiovascular system are closely interconnected, with immune cells playing a crucial role in maintaining cardiac health and influencing disease progression. Consequently, alterations in the cardiac microenvironment are influenced and controlled by various immune cells, such as macrophages, neutrophils, dendritic cells, eosinophils, and T-lymphocytes, along with the cytokines they produce. Furthermore, studies have revealed that Gata6+ pericardial cavity macrophages play a key role in regulating immune cell migration and subsequent myocardial tissue repair post IHD onset. This review outlines the role of immune cells in orchestrating inflammatory responses and facilitating myocardial repair following IHD, considering both macro and micro views. It also discusses innovative immune cell-based therapeutic strategies, offering new insights for further research on the pathophysiology of ischemic heart disease and immune cell-targeted therapy for IHD.

Corosolic acid attenuates cardiac ischemia/reperfusion injury through the PHB2/PINK1/parkin/mitophagy pathway.

Despite advances in treatment, myocardial infarction remains the leading cause of heart failure and death worldwide, and the restoration of coronary blood flow can also cause heart damage. In this study, we found that corosolic acid (CA), also known as plant insulin, significantly protects the heart from ischemia-reperfusion (I/R) injury. In addition, CA can inhibit oxidative stress and improve mitochondrial structure and function in cardiomyocytes. Subsequently, our study demonstrated that CA improved the expression of the mitophagy-related proteins Prohibitin 2 (PHB2), PTEN-induced putative kinase protein-1 (PINK1), and Parkin. Meanwhile, through molecular docking, we found an excellent binding between CA and PHB2 protein. Finally, the knockdown of PHB2 eliminated the protective effect of CA on hypoxia-reoxygenation in cardiomyocytes. Taken together, our study reveals that CA increases mitophagy in cardiomyocytes via the PHB2/PINK1/Parkin signaling pathway, inhibits oxidative stress response, and maintains mitochondrial function, thereby improving cardiac function after I/R.

Multi-omics analysis of Populus simonii × P. nigra leaves under Hyphantria cunea stress.

Poplar is an important greening and timber tree species in China, which has great economic and ecological values. However, the spread of Hyphantria cunea has become increasingly serious in recent years, resulting in huge economic loss of poplar production. Exploring the molecular mechanism of poplar reponse to H. cunea stress has significant implications for future development of new insect-resistant poplar varieties using genetic engineering technology. In this study, a total of 1039 differentially expressed genes (DEGs), 106 differentially expressed proteins (DEPs) and 212 differentially expressed metabolites (DEMs) were screened from Populus simonii × P. nigra leaves under H. cunea stress by transcriptome, proteomics and metabolomics analysis, respectively. GO and KEGG analysis showed that the DEGs and DEPs are associated with endopeptidase inhibitor activity, stress response, α-linolenic acid metabolism, phenylpropanoid biosynthesis and metabolic pathways, cysteine and methionine metabolism pathways and MAKP signaling pathway. Metabolomics analysis showed the most of DEMs were lipids and lipid molecules, and the pathways associated with transcriptome mainly include plant hormone signal transduction, α-linolenic acid metabolic pathway, amino sugar and nucleotide sugar metabolism, and phenylpropanoid biosynthesis. In particular, multi-omics analysis showed that several pathways such as α-linolenic acid metabolic, phenylpropanoid biosynthesis and metabolic pathway and cysteine and methionine metabolic pathway were significantly enriched in the three omics, which may play an important role in the resistance to pests in poplar.

PagbHLH35 Enhances Salt Tolerance through Improving ROS Scavenging in Transgenic Poplar.

The bHLH transcription factor family plays crucial roles in plant growth and development and their responses to adversity. In this study, a highly salt-induced bHLH gene, PagbHLH35 (Potri.018G141600), was identified from Populus alba × P. glandullosa (84K poplar). PagbHLH35 contains a highly conserved bHLH domain within the region of 52-114 amino acids. A subcellular localization result confirmed its nuclear localization. A yeast two-hybrid assay indicated PagbHLH35 lacks transcriptional activation activity, while a yeast one-hybrid assay indicated it could specifically bind to G-box and E-box elements. The expression of PagbHLH35 reached its peak at 12 h and 36 h time points under salt stress in the leaves and roots, respectively. A total of three positive transgenic poplar lines overexpressing PagbHLH35 were generated via Agrobacterium-mediated leaf disk transformation. Under NaCl stress, the transgenic poplars exhibited significantly enhanced morphological and physiological advantages such as higher POD activity, SOD activity, chlorophyll content, and proline content, and lower dehydration rate, MDA content and hydrogen peroxide (H2O2) content, compared to wild-type (WT) plants. In addition, histological staining showed that there was lower ROS accumulation in the transgenic poplars under salt stress. Moreover, the relative expression levels of several antioxidant genes in the transgenic poplars were significantly higher than those in the WT. All the results indicate that PagbHLH35 can improve salt tolerance by enhancing ROS scavenging in transgenic poplars.

Risk factors and outcomes associated with systolic dysfunction following traumatic brain injury.

Systolic dysfunction has been observed following isolated moderate-severe traumatic brain injury (Ims-TBI). However, early risk factors for the development of systolic dysfunction after Ims-TBI and their impact on the prognosis of patients with Ims-TBI have not been thoroughly investigated. A prospective observational study among patients aged 16 to 65 years without cardiac comorbidities who sustained Ims-TBI (Glasgow Coma Scale [GCS] score ≤12) was conducted. Systolic dysfunction was defined as left ventricular ejection fraction <50% or apparent regional wall motion abnormality assessed by transthoracic echocardiography within 24 hours after admission. The primary endpoint was the incidence of systolic dysfunction after Ims-TBI. The secondary endpoint was survival on discharge. Clinical data and outcomes were assessed within 24 hours after admission or during hospitalization. About 23 of 123 patients (18.7%) developed systolic dysfunction after Ims-TBI. Higher admission heart rate (odds ratios [ORs]: 1.05, 95% confidence interval [CI]: 1.02-1.08; P = .002), lower admission GCS score (OR: 0.77, 95% CI: 0.61-0.96; P = .022), and higher admission serum high-sensitivity cardiac troponin T (Hs-cTnT) (OR: 1.14, 95% CI: 1.06-1.22; P < .001) were independently associated with systolic dysfunction among patients with Ims-TBI. A combination of heart rate, GCS score, and serum Hs-cTnT level on admission improved the predictive performance for systolic dysfunction (area under curve = 0.85). Duration of mechanical ventilation, intensive care unit length of stay, and in-hospital mortality of patients with systolic dysfunction was higher than that of patients with normal systolic function (P < .05). Lower GCS (OR: 0.66, 95% CI: 0.45-0.82; P = .001), lower admission oxygen saturation (OR: 0.82, 95% CI: 0.69-0.98; P = .025), and the development of systolic dysfunction (OR: 4.85, 95% CI: 1.36-17.22; P = .015) were independent risk factors for in-hospital mortality in patients with Ims-TBI. Heart rate, GCS, and serum Hs-cTnT level on admission were independent early risk factors for systolic dysfunction in patients with Ims-TBI. The combination of these 3 parameters can better predict the occurrence of systolic dysfunction.

Physiological and molecular mechanism of Populus pseudo-cathayana × Populus deltoides response to Hyphantria cunea.

Populus pseudo-cathayana × Populus deltoides is a crucial artificial forest tree species in Northeast China. The presence of the fall webworm (Hyphantria cunea) poses a significant threat to these poplar trees, causing substantial economic and ecological damage. This study conducted an insect-feeding experiment with fall webworm on P. pseudo-cathayana × P. deltoides, examining poplar's physiological indicators, transcriptome, and metabolome under different lengths of feeding times. Results revealed significant differences in phenylalanine ammonia-lyase activity, total phenolic content, and flavonoids at different feeding durations. Transcriptomic analysis identified numerous differentially expressed genes, including AP2/ERF, MYB, and WRKY transcription factor families exhibiting the highest expression variations. Differential metabolite analysis highlighted flavonoids and phenolic acid compounds of poplar's leaves as the most abundant in our insect-feeding experiment. Enrichment analysis revealed significant enrichment in the plant hormone signal transduction and flavonoid biosynthetic pathways. The contents of jasmonic acid and jasmonoyl-L-isoleucine increased with prolonged fall webworm feeding. Furthermore, the accumulation of dihydrokaempferol, catechin, kaempferol, and naringenin in the flavonoid biosynthesis pathway varied significantly among different samples, suggesting their crucial role in response to pest infestation. These findings provide novel insights into how poplar responds to fall webworm infestation.

CatLet score and clinical CatLet score as predictors of long-term outcomes in patients with acute myocardial infarction presenting later than 12 hours from symptom onset.

BACKGROUND: Our recently developed Coronary Artery Tree description and Lesion EvaluaTion (CatLet) angiographic scoring system is unique in its description of the variability in the coronary anatomy, the degree of stenosis of a diseased coronary artery, and its subtended myocardial territory, and can be utilized to predict clinical outcomes for patients with acute myocardial infarction (AMI) presenting ≤12 h after symptom onset. The current study aimed to assess whether the Clinical CatLet score (CCS), as compared with CatLet score (CS), better predicted clinical outcomes for AMI patients presenting >12 h after symptom onset. METHODS: CS was calculated in 1018 consecutive AMI patients enrolled in a retrospective registry. CCS was calculated by multiplying CS by the ACEF I score (age, creatinine, and left ventricular ejection fraction). Primary endpoint was major adverse cardiac events (MACEs) at 4-year-follow-up, a composite of cardiac death, myocardial infarction, and ischemia-driven revascularization. RESULTS: Over a 4-year follow-up period, both scores were independent predictors of clinical outcomes after adjustment for a broad spectrum of risk factors. Areas-under-the-curve (AUCs) for CS and CCS were 0.72(0.68-0.75) and 0.75(0.71-0.78) for MACEs; 0.68(0.63-0.73) and 0.78(0.74-0.83) for all-cause death; 0.73(0.68-0.79) and 0.83(0.79-0.88) for cardiac death; and 0.69(0.64-0.73) and 0.75(0.7-0.79) for myocardial infarction; and 0.66(0.61-0.7) and 0.63(0.58-0.68) for revascularization, respectively. CCS performed better than CS in terms of the above-mentioned outcome predictions, as confirmed by the net reclassification and integrated discrimination indices. CONCLUSIONS: CCS was better than CS to be able to risk-stratify long-term outcomes in AMI patients presenting >12 h after symptom onset. These findings have indicated that both anatomic and clinical variables should be considered in decision-making on management of patients with AMI presenting later.

Transcription Factor McHB7 Improves Ice Plant Drought Tolerance through ABA Signaling Pathway.

As global climate change continues, drought episodes have become increasingly frequent. Studying plant stress tolerance is urgently needed to ensure food security. The common ice plant is one of the model halophyte plants for plant stress biology research. This study aimed to investigate the functions of a newly discovered transcription factor, Homeobox 7 (HB7), from the ice plant in response to drought stress. An efficient Agrobacterium-mediated transformation method was established in the ice plant, where ectopic McHB7 expression may be sustained for four weeks. The McHB7 overexpression (OE) plants displayed drought tolerance, and the activities of redox enzymes and chlorophyll content in the OE plants were higher than the wild type. Quantitative proteomics revealed 1910 and 495 proteins significantly changed in the OE leaves compared to the wild type under the control and drought conditions, respectively. Most increased proteins were involved in the tricarboxylic acid cycle, photosynthesis, glycolysis, pyruvate metabolism, and oxidative phosphorylation pathways. Some were found to participate in abscisic acid signaling or response. Furthermore, the abscisic acid levels increased in the OE compared with the wild type. McHB7 was revealed to bind to the promoter motifs of Early Responsive to Dehydration genes and abscisic acid-responsive genes, and protein-protein interaction analysis revealed candidate proteins responsive to stresses and hormones (e.g., abscisic acid). To conclude, McHB7 may contribute to enhance plant drought tolerance through abscisic acid signaling.

Exosomes based strategies for cardiovascular diseases: Opportunities and challenges.

Exosomes, as nanoscale extracellular vesicles (EVs), are secreted by all types of cells to facilitate intercellular communication in living organisms. After being taken up by neighboring or distant cells, exosomes can alter the expression levels of target genes in recipient cells and thereby affect their pathophysiological outcomes depending on payloads encapsulated therein. The functions and mechanisms of exosomes in cardiovascular diseases have attracted much attention in recent years and are thought to have cardioprotective and regenerative potential. This review summarizes the biogenesis and molecular contents of exosomes and details the roles played by exosomes released from various cells in the progression and recovery of cardiovascular disease. The review also discusses the current status of traditional exosomes in cardiovascular tissue engineering and regenerative medicine, pointing out several limitations in their application. It emphasizes that some of the existing emerging industrial or bioengineering technologies are promising to compensate for these shortcomings, and the combined application of exosomes and biomaterials provides an opportunity for mutual enhancement of their performance. The integration of exosome-based cell-free diagnostic and therapeutic options will contribute to the further development of cardiovascular regenerative medicine.

Overexpression of the PtrNF-YA6 gene inhibits secondary cell wall thickening in poplar.

The NF-Y gene family in plants plays a crucial role in numerous biological processes, encompassing hormone response, stress response, as well as growth and development. In this study, we first used bioinformatics techniques to identify members of the NF-YA family that may function in wood formation. We then used molecular biology techniques to investigate the role and molecular mechanism of PtrNF-YA6 in secondary cell wall (SCW) formation in Populus trichocarpa. We found that PtrNF-YA6 protein was localized in the nucleus and had no transcriptional activating activity. Overexpression of PtrNF-YA6 had an inhibitory effect on plant growth and development and significantly suppressed hemicellulose synthesis and SCW thickening in transgenic plants. Yeast one-hybrid and ChIP-PCR assays revealed that PtrNF-YA6 directly regulated the expression of hemicellulose synthesis genes (PtrGT47A-1, PtrGT8C, PtrGT8F, PtrGT43B, PtrGT47C, PtrGT8A and PtrGT8B). In conclusion, PtrNF-YA6 can inhibit plant hemicellulose synthesis and SCW thickening by regulating the expression of downstream SCW formation-related target genes.

Methylation of microRNA genes and its effect on secondary xylem development of stem in poplar.

MicroRNAs (miRNAs) and DNA methylation are both vital regulators of gene expression. DNA methylation can affect the transcription of miRNAs, just like coding genes, through methylating the CpG islands in the gene regions of miRNAs. Although previous studies have shown that DNA methylation and miRNAs can each be involved in the process of wood formation, the relationship between the two has been relatively little studied in plant wood formation. Studies have shown that the second internode (IN2) (from top to bottom) of 3-month-old poplar trees can represent the primary stage of poplar stem development and IN8 can represent the secondary stage. There were also significant differences in DNA methylation patterns and miRNA expression patterns obtained from PS and SS. In this study, we first interactively analyzed methylation and miRNA sequencing data to identify 43 differentially expressed miRNAs regulated by differential methylation from the primary stage and secondary stage, which were found to be involved in multiple biological processes related to wood formation by enrichment analysis. In addition, six miRNA/target gene modules were finally identified as potentially involved in secondary xylem development of poplar stems through degradome sequencing and functional analysis. In conclusion, this study provides important reference information on the mechanism of interaction between different regulatory pathways of wood formation.

Epigenetic age acceleration and risk of aortic valve stenosis: a bidirectional Mendelian randomization study.

BACKGROUND: Aortic valve stenosis (AVS) is the most prevalent cardiac valve lesion in developed countries, and pathogenesis is closely related to aging. DNA methylation-based epigenetic clock is now recognized as highly accurate predictor of the aging process and associated health outcomes. This study aimed to explore the causal relationship between epigenetic clock and AVS by conducting a bidirectional Mendelian randomization (MR) analysis. METHODS: Summary genome-wide association study statistics of epigenetic clocks (HannumAge, HorvathAge, PhenoAge, and GrimAge) and AVS were obtained and assessed for significant instrumental variables from Edinburgh DataShare (n = 34,710) and FinnGen biobank (cases = 9870 and controls = 402,311). The causal association between epigenetic clock and AVS was evaluated using inverse variance weighted (IVW), weighted median (WM), and MR-Egger methods. Multiple analyses (heterogeneity analysis, pleiotropy analysis, and sensitivity analysis) were performed for quality control assessment. RESULTS: The MR analysis showed that the epigenetic age acceleration of HorvathAge and PhenoAge was associated with an increased risk of AVS (HorvathAge: OR = 1.043, P = 0.016 by IVW, OR = 1.058, P = 0.018 by WM; PhenoAge: OR = 1.058, P = 0.005 by IVW, OR = 1.053, P = 0.039 by WM). Quality control assessment proved our findings were reliable and robust. However, there was a lack of evidence supporting a causal link from AVS to epigenetic aging. CONCLUSION: The present MR analysis unveiled a causal association between epigenetic clocks, especially HorvathAge and PhenoAge, with AVS. Further research is required to elucidate the underlying mechanisms and develop strategies for potential interventions.

Elevated uric acid/albumin ratio as a predictor of poor coronary collateral circulation development in patients with non-ST segment elevation myocardial infarction.

BACKGROUND: Uric acid/albumin ratio (UAR) is a novel composite biomarker with superior predictive value for cardiovascular disease. OBJECTIVE: To investigate the relationship between UAR and coronary collateral circulation (CCC) in patients with non-ST segment elevation myocardial infarction (NSTEMI). METHODS: A total of 205 NSTEMI patients who underwent coronary arteriography with at least one major coronary stenosis, 95% were included. Patients were divided into two groups according to CCC development: poorly-developed CCC group (Rentrop 0-1) and well-developed CCC (Rentrop 2-3). Univariate analysis and logistic regression analysis were utilized to investigate the factors influencing adverse CCC formation in NSTEMI patients. The receiver operating characteristic (ROC) curve was plotted to evaluate the predictive value of UAR, C-reactive protein (CRP), uric acid, and albumin for patients with poorly developed CCC, and the area under the curve (AUC) was compared. RESULTS: The UAR values of NSTEMI patients were significantly higher in the poorly developed CCC group than those in the well-developed CCC group (10.19 [8.80-11.74] vs. 7.79 [6.28-9.55], p < .001). In the multiple logistic regression tests, UAR (odds ratio [OR]: 1.365, 95% confidence interval [CI]: 1.195-1.560, p < .001), CRP (OR: 1.149, 95% CI: 1.072-1.231, p < .001), and diabetes (OR: 2.924, 95% CI: 1.444-5.920, p = .003) were independent predictors of poorly developed CCC. The ROC curve analysis showed that the optimal cut-off value of UAR was 8.78 in predicting poorly developed CCC with a sensitivity of 76.8% and specificity of 62.4%, with the AUC of 0.737 (95% Cl: 0.668-0.805, p < .001). CONCLUSION: Elevated UAR may be an independent and effective biomarker for predicting poorly-developed CCC development in NSTEMI patients.

Developing and Validating a Simple Risk Score for Patients with Acute Myocardial Infarction.

INTRODUCTION: Mortality from acute myocardial infarction (AMI) remains substantial. The current study is aimed at developing a novel simple risk score for AMI. METHODS: The Coronary Artery Tree description and Lesion EvaluaTion (CatLet) extended validation trial (ChiCTR2000033730) and the CatLet validation trial (ChiCTR-POC-17013536), both being registered with chictr.org, served as the derivation and validation datasets, respectively. Both datasets included 1,018 and 308 patients, respectively. They all suffered from AMI and underwent percutaneous intervention (PCI). The endpoint was 4-year all-cause death. Lasso regression analysis was used for covariate selection and coefficient estimation. RESULTS: Of 26 candidate predictor variables, the four strongest predictors for 4-year mortality were included in this novel risk score with an acronym of BACEF (serum alBumin, Age, serum Creatinine, and LVEF). This score was well calibrated and yielded an AUC (95% CI) statistics of 0.84 (0.80-0.87) in internal validation, 0.89 (0.83-0.95) in internal-external (temporal) validation, and 0.83 (0.77-0.89) in external validation. Notably, it outperformed the ACEF, ACEF II, GRACE scores with respect to 4-year mortality prediction. CONCLUSION: A simple risk score for 4-year mortality risk stratification was developed, extensively validated, and calibrated in patients with AMI. This novel BACEF score may be a useful risk stratification tool for patients with AMI.

Comprehensive view of macrophage autophagy and its application in cardiovascular diseases.

Cardiovascular diseases (CVDs) are the primary drivers of the growing public health epidemic and the leading cause of premature mortality and economic burden worldwide. With decades of research, CVDs have been proven to be associated with the dysregulation of the inflammatory response, with macrophages playing imperative roles in influencing the prognosis of CVDs. Autophagy is a conserved pathway that maintains cellular functions. Emerging evidence has revealed an intrinsic connection between autophagy and macrophage functions. This review focuses on the role and underlying mechanisms of autophagy-mediated regulation of macrophage plasticity in polarization, inflammasome activation, cytokine secretion, metabolism, phagocytosis, and the number of macrophages. In addition, autophagy has been shown to connect macrophages and heart cells. It is attributed to specific substrate degradation or signalling pathway activation by autophagy-related proteins. Referring to the latest reports, applications targeting macrophage autophagy have been discussed in CVDs, such as atherosclerosis, myocardial infarction, heart failure, and myocarditis. This review describes a novel approach for future CVD therapies.

CXCR4-overexpressed exosomes from cardiosphere-derived cells attenuate myocardial ischemia/reperfusion injury by transferring miRNA to macrophages and regulating macrophage polarization.

Cardiosphere-derived cells (CDCs) are emerging as ideal candidates for managing cardiac inflammation, albeit with some limitations. Recent literatures have indicated that exosomes secreted by CDCs with C-X-C motif chemokine receptor 4 (CXCR4) overexpression can promote cardiac function after myocardial infarction and there have been some reports of miRNAs involved in ischemia/reperfusion (I/R) therapy. Therefore, we are interested in the role of CXCR4-overexpressed CDC-derived exosomes in delivering specific miRNA after myocardial I/R injury. In this research, we first constructed CDC-derived exosomes that overexpressed CXCR4 and miR-27a-5p, miR-182, or miR-101a. Then, we co-cultured the engineered exosomes with RAW264.7 cells and injected them intravenously into myocardial I/R model mice. In vitro, results showed that proinflammatory cytokines levels in the culture supernatant were decreased and the expression of M2 phenotypic markers were increased. Administration of engineered exosomes improved cardiac function, reduced infarct size, alleviated macrophage infiltration, and regulated M2 macrophage polarization after myocardial I/R, suggesting their implications in cardiac injury repair.

Cucurbitacin B protects against myocardial ischemia-reperfusion injury through activating JAK2/STAT3 signaling pathway.

Cucurbitacin B, a tetracyclic triterpenoid compound extracted from various plants, has been proven to exert a vital role in various diseases. However, the effect of cucurbitacin B on myocardial infarction (MI) and ischemia-reperfusion (I/R) injury is still relatively unclear. The main purpose of the present study was to investigate the effect of cucurbitacin B on cell apoptosis and oxidative damage after myocardial I/R injury in vitro and in vivo and elucidate the molecular mechanisms underlying its role. The 56-day-old adult mice and 1-day-old neonatal mice cardiomyocytes were used to construct I/R or oxygen-glucose deprivation/reoxygenation (OGD/R) injury models. The oxidative injury, western blot and TUNEL assay were performed to evaluate cardiomyocyte damage in the present study. In vitro， we confirmed that cucurbitacin B could attenuate LDH release, oxidative stress and cell apoptosis in cardiomyocytes exposed to OGD/R. Besides, we confirmed in an adult I/R mouse model that cucurbitacin B can improve cardiac repair and block cell apoptosis in the acute phase (24 h) post-myocardial I/R injury, as well as promote long-term cardiac function and fiber scar area after 28 days of I/R. Mechanically, we clarify that cucurbitacin B exerts cardiomyocyte protective effects through activating the JAK2/STAT3 signaling pathway. In conclusion, our study elucidates for the first time the protective role of cucurbitacin B in cardiac I/R injury, which provides a novel perspective for better prevention of I/R injury through the JAK2/STAT3 signaling pathway.

Unraveling the Guardians of Growth: A Comprehensive Analysis of the Aux/IAA and ARF Gene Families in Populus simonii.

The auxin/indole-3-acetic acid (Aux/IAA) and auxin response factor (ARF) genes are two crucial gene families in the plant auxin signaling pathway. Nonetheless, there is limited knowledge regarding the Aux/IAA and ARF gene families in Populus simonii. In this study, we first identified 33 putative PsIAAs and 35 PsARFs in the Populus simonii genome. Analysis of chromosomal location showed that the PsIAAs and PsARFs were distributed unevenly across 17 chromosomes, with the greatest abundance observed on chromosomes 2. Furthermore, based on the homology of PsIAAs and PsARFs, two phylogenetic trees were constructed, classifying 33 PsIAAs and 35 PsARFs into three subgroups each. Five pairs of PsIAA genes were identified as the outcome of tandem duplication, but no tandem repeat gene pairs were found in the PsARF family. The expression profiling of PsIAAs and PsARFs revealed that several genes exhibited upregulation in different tissues and under various stress conditions, indicating their potential key roles in plant development and stress responses. The variance in expression patterns of specific PsIAAs and PsARFs was corroborated through RT-qPCR analysis. Most importantly, we instituted that the PsIAA7 gene, functioning as a central hub, exhibits interactions with numerous Aux/IAA and ARF proteins. Furthermore, subcellular localization findings indicate that PsIAA7 functions as a protein localized within the nucleus. To conclude, the in-depth analysis provided in this study will contribute significantly to advancing our knowledge of the roles played by PsIAA and PsARF families in both the development of P. simonii tissue and its responses to stress. The insights gained will serve as a valuable asset for further inquiries into the biological functions of these gene families.