Identification of Hypoxia Induced Metabolism Associated Genes in Pulmonary Hypertension

MicroRNA-210 mediates hypoxia-induced pulmonary hypertension by targeting mitochondrial bioenergetics and mtROS flux

AIM

Chronic hypoxia is a common cause of pulmonary hypertension (PH). We test the hypothesis that microRNA-210 (miR-210) mediates hypoxia-induced PH by targeting mitochondrial metabolism and increasing reactive oxygen species (mtROS) production in the lungs.

METHODS

Adult wildtype (WT) or miR-210 knockout (KO) mice were exposed to hypoxia (10.5% O2) or normoxia for 4 weeks. We measured miR-210 levels, right ventricular systolic pressure (RVSP), and histological changes in heart and lung tissues. Mitochondrial bioenergetics and mtROS production were assessed in isolated lung mitochondria.

RESULTS

Hypoxia increased right ventricular wall thickness and pulmonary vessel wall muscularization in WT, but not miR-210 KO mice. No sex differences were observed. In male mice, hypoxia increased miR-210 levels in the lung and RVSP, which were abrogated by miR-210 deficiency. Hypoxia upregulated mitochondrial oxygen consumption rate and mtROS flux, which were negated in miR-210 KO animals. In addition, chronic hypoxia increased macrophage accumulation in lungs of WT, but not miR-210 KO mice. Moreover, miR-210 overexpression in lungs of WT animals recapitulated the effects of hypoxia and increased mitochondrial oxygen consumption rate, mtROS flux, right ventricular wall thickness, pulmonary vessel wall muscularization and RVSP. MitoQ revoked the effects of miR-210 on lung mitochondrial bioenergetics, right ventricular and pulmonary vessel remodeling and RVSP.

CONCLUSION

Our findings with loss-of-function and gain-of-function approaches provide explicit evidence that miR-210 mediates hypoxia-induced PH by upregulating mitochondrial bioenergetics and mtROS production in a murine model, revealing new insights into the mechanisms and therapeutic targets for treatment of PH.

Insights into the Role of Glutathione Peroxidase 3 in Non-Neoplastic Diseases

Reactive oxygen species (ROSs) are byproducts of normal cellular metabolism and play pivotal roles in various physiological processes. Disruptions in the balance between ROS levels and the body's antioxidant defenses can lead to the development of numerous diseases. Glutathione peroxidase 3 (GPX3), a key component of the body's antioxidant system, is an oxidoreductase enzyme. GPX3 mitigates oxidative damage by catalyzing the conversion of hydrogen peroxide into water. Beyond its antioxidant function, GPX3 is vital in regulating metabolism, modulating cell growth, inducing apoptosis and facilitating signal transduction. It also serves as a significant tumor suppressor in various cancers. Recent studies have revealed aberrant expression of GPX3 in several non-neoplastic diseases, associating it with multiple pathological processes. This review synthesizes the current understanding of GPX3 expression and regulation, highlighting its extensive roles in noncancerous diseases. Additionally, this paper evaluates the potential of GPX3 as a diagnostic biomarker and explores emerging therapeutic strategies targeting this enzyme, offering potential avenues for future clinical treatment of non-neoplastic conditions.

Exploring the Potential Mechanisms of Guanxinshutong Capsules in Treating Pathological Cardiac Hypertrophy based on Network Pharmacology, Computer-Aided Drug Design, and Animal Experiments

Cardiovascular diseases (CVDs) are significant causes of morbidity and mortality worldwide, and pathological cardiac hypertrophy (PCH) is an essential predictor of many heart diseases. Guanxinshutong capsule (GXST) is a Chinese patent medicine widely used in the clinical treatment of CVD, In our previous research, we identified 111 compounds of GXST. In order to reveal the potential molecular mechanisms by which GXST treats PCH, this study employed network pharmacology methods to screen for the active ingredients of GXST in treating PCH and predicted the potential targets. The results identified 26 active ingredients of GXST and 110 potential targets for PCH. Through a protein-protein interaction (PPI) network, gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, we confirmed AKT1, MAPK1, and MAPK3 as the core proteins in GXST treatment of PCH, thus establishing the PI3K/AKT and MAPK signaling pathways as the significant mechanisms of GXST in treating PCH. The results of molecular docking (MD) demonstrate that flavonoid naringenin and diterpenoid tanshinone iia have the highest binding affinity with the core protein. Before performing molecular dynamics simulations (MDSs), the geometric structure of naringenin and tanshinone iia was optimized using density functional theory (DFT) at the B97-3c level, and RESP2 atomic charge calculations were carried out at the B3LYP-D3(BJ)/def2-TZVP level. Further MDS results demonstrated that in the human body environment, the complex of naringenin and tanshinone iii with core proteins exhibited high stability, flexibility, and low binding free energy. Additionally, naringenin and tanshinone iia showed favorable absorption, distribution, metabolism, excretion, and toxicity (ADMET) characteristics and passed the drug similarity (DS) assessment. Ultrasound cardiograms and cardiac morphometric measurements in animal experiments demonstrate that GXST can improve the PCH induced by isoproterenol (ISO). Protein immunoblotting results indicate that GXST increases the expression of P-eNOS and eNOS by activating the PI3K/AKT signaling pathway and the MAPK signaling pathway, further elucidating the mechanism of action of GXST in treating PCH. This study contributes to the elucidation of the key ingredients and molecular mechanisms of GXST in treating PCH.

Matrine alleviates hypoxia-induced inflammation and pulmonary vascular remodelling via RPS5/NF-κB signalling pathway

Hypoxia-induced vasoconstriction and vascular remodelling are the main pathological features of hypoxic pulmonary arterial hypertension (HPAH), and inflammation is participated in the occurrence of pulmonary vascular remodelling (PVR). Matrine is an alkaloid with the effects of anti-inflammation, antifibrosis and antitumour. But, few studies have explored the role of matrine in regulating PVR, and the related mechanisms are still unknown. In this study, we found that hypoxia-induced pulmonary artery smooth muscle cells (PASMCs) proliferation and inhibited its apoptosis, reduced the expression of ribosomal protein s5 and activated the nuclear factor kappa-B (NF-κB) signalling. Matrine, sildenafil and NF-κB inhibitor Bay 11-7082 could reverse these changes and impel the cell cycle in phase S retardation, and reduced the expression of p50, p65, proliferating cell nuclear antigen (PCNA), Bcl-2. In addition, matrine could lower right ventricular systolic pressure and mean pulmonary artery pressure of rats, α-smooth muscle actin and PCNA expression in pulmonary artery media, the levels of tumor necrosis factor-α and interleuki-1β, thus improved hypoxia-induced PVR. This study indicated that matrine could alleviate inflammation and improve PVR through reversing the imbalance of proliferation and apoptosis of PASMCs, thus it had a therapeutic effect on HPAH.

Role of macrophages in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a severe cardiopulmonary vascular disease characterized by progressive pulmonary artery pressure elevation, increased pulmonary vascular resistance and ultimately right heart failure. Studies have demonstrated the involvement of multiple immune cells in the development of PAH in patients with PAH and in experimental PAH. Among them, macrophages, as the predominant inflammatory cells infiltrating around PAH lesions, play a crucial role in exacerbating pulmonary vascular remodeling in PAH. Macrophages are generally polarized into (classic) M1 and (alternative) M2 phenotypes, they accelerate the process of PAH by secreting various chemokines and growth factors (CX3CR1, PDGF). In this review we summarize the mechanisms of immune cell action in PAH, as well as the key factors that regulate the polarization of macrophages in different directions and their functional changes after polarization. We also summarize the effects of different microenvironments on macrophages in PAH. The insight into the interactions between macrophages and other cells, chemokines and growth factors may provide important clues for the development of new, safe and effective immune-targeted therapies for PAH.

Metabolic reprogramming: A novel metabolic model for pulmonary hypertension

Pulmonary arterial hypertension, or PAH, is a condition that is characterized by pulmonary artery pressures above 20 mmHg (at rest). In the treatment of PAH, the pulmonary vascular system is regulated to ensure a diastolic and contraction balance; nevertheless, this treatment does not prevent or reverse pulmonary vascular remodeling and still causes pulmonary hypertension to progress. According to Warburg, the link between metabolism and proliferation in PAH is similar to that of cancer, with a common aerobic glycolytic phenotype. By activating HIF, aerobic glycolysis is enhanced and cell proliferation is triggered. Aside from glutamine metabolism, the Randle cycle is also present in PAH. Enhanced glutamine metabolism replenishes carbon intermediates used by glycolysis and provides energy to over-proliferating and anti-apoptotic pulmonary vascular cells. By activating the Randle cycle, aerobic oxidation is enhanced, ATP is increased, and myocardial injury is reduced. PAH is predisposed by epigenetic dysregulation of DNA methylation, histone acetylation, and microRNA. This article discusses the abnormal metabolism of PAH and how metabolic therapy can be used to combat remodeling.

The role of prolactin/vasoinhibins in cardiovascular diseases

Prolactin (PRL) is a polypeptide hormone that is mainly synthesized and secreted by the lactotroph cells of the pituitary. There are two main isoforms of PRL: 23-kDa PRL (named full-length PRL) and vasoinhibins (including 5.6-18 kDa fragments). Both act as circulating hormones and cytokines to stimulate or inhibit vascular formation at different stages and neovascularization, including endothelial cell proliferation and migration, protease production, and apoptosis. However, their effects on vascular function and cardiovascular diseases are different or even contrary. In addition to the structure, secretion regulation, and signal transduction of PRL/vasoinhibins, this review focuses on the pathological mechanism and clinical significance of PRL/vasoinhibins in cardiovascular diseases.

Regulatory T Cell-Related Gene Indicators in Pulmonary Hypertension

Objective: Regulatory T cells (Tregs) are critical immune modulators to maintain immune homeostasis and limit pulmonary hypertension (PH). This study was aimed to identify Treg-related genes (TRGs) in PH.

Methods: The gene expression profile from lungs of PH patients was retrieved from the Gene Expression Omnibus (GEO) database. The abundance of Tregs was estimated by the xCell algorithm, the correlation of which with differentially expressed genes (DEGs) was performed. DEGs with a |Pearson correlation coefficient| >0.4 were identified as TRGs. Functional annotation and the protein–protein interaction (PPI) network were analyzed. A gene signature for 25 hub TRGs (TRGscore) was generated by a single sample scoring method to determine its accuracy to distinguish PH from control subjects. TRGs were validated in datasets of transcriptional profiling of PH cohorts and in lung tissues of experimental PH mice.

Results: A total of 819 DEGs were identified in lungs of 58 PAH patients compared to that of 25 control subjects of dataset GSE117261. In total, 165 of all these DEGs were correlated with the abundance of Tregs and identified as TRGs, with 90 upregulated genes and 75 downregulated genes compared to that of control subjects. The upregulated TRGs were enriched in negative regulation of multiple pathways, such as cAMP-mediated signaling and I-kappaB kinase/NF-kappaB signaling, and regulated by multiple genes encoding transcriptional factors including HIF1A. Furthermore, 25 hub genes categorized into three clusters out of 165 TRGs were derived, and we identified 27 potential drugs targeting 10 hub TRGs. The TRGscore based on 25 hub TRGs was higher in PH patients and could distinguish PH from control subjects (all AUC >0.7). Among them, 10 genes including NCF2, MNDA/Ifi211, HCK, FGR, CSF3R, AQP9, S100A8, G6PD/G6pdx, PGD, and TXNRD1 were significantly reduced in lungs of severe PH patients of dataset GSE24988 as well as in lungs of hypoxic PH mice compared to corresponding controls.

Conclusion: Our finding will shed some light on the Treg-associated therapeutic targets in the progression of PH and emphasize on TRGscore as a novel indicator for PH.

Predicting potential biomarkers and immune infiltration characteristics in heart failure

BACKGROUND

Studies have demonstrated that immune cell activation and their infiltration in the myocardium can have adverse effects on the heart, contributing to the pathogenesis of heart failure (HF). The purpose of this study is used by bioinformatics analysis to determine the potential diagnostic markers of heart failure and establish an applicable model to predict the association between heart failure and immune cell infiltration.

METHODS

Firstly, gene expression profiles of dilated heart disease GSE3585 and GSE120895 were obtained in Gene Expression Omnibus (GEO) database. This study then selected differentially expressed genes (DEGs) in 54 patients with HF and 13 healthy controls. In this study, biomarkers were identified using Least Absolute Shrinkage and Selector Operation (LASSO) and Support Vector Machine-Recursive Feature Elimination (SVM-RFE). Additionally, we evaluated the prognostic discrimination performance by the receiver operating characteristic (ROC) curve. Cell type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) was used for analyzing immune cell infiltration in HF tissues. Lastly, immune biomarkers were correlated with each other.

RESULT

After 24 DEGs were analyzed using a combinatorial model of LASSO regression and SVM-RFE analysis, four key genes were obtained, namely NSG1, NPPB, PHLDA1, and SERPINE2.The area under the curve (AUC) of these four genes were greater than 0.8. Subsequently, using CIBERPORT, we also found that compared with normal people, the proportion of M1 macrophages and activated mast cells in heart failure tissues decreased. In addition, correlation analysis showed that NPPB, PHLDA1 and SERPINE2 were associated with immune cell infiltration.

CONCLUSION

NSG1, NPPB, PHLDA1 and SERPINE2 were identified as potential biomarkers of heart failure. It reveals the comprehensive role of relevant central genes in immune infiltration, which provides a new research idea for the treatment and early detection in heart failure.

L-Carnitine Alleviates the Myocardial Infarction and Left Ventricular Remodeling through Bax/Bcl-2 Signal Pathway

Purpose

L-carnitine (LC) is considered to have good therapeutic potential for myocardial infarction (MI), but its mechanism has not been clarified. The aim of the study is to elucidate the cardioprotective effects of LC in mice following MI and related mechanisms.

Methods

ICR mice were treated with LC for 2 weeks after induction of MI with ligation of left anterior descending artery. Electrocardiographic (ECG) recording and echocardiography were used to evaluate cardiac function. H&E staining, TTC staining, and Masson staining were performed for morphological analysis and cardiac fibrosis. ELISA and immunofluorescence were utilized to detect biomarkers and inflammatory mediators. The key proteins in the Bax/Bcl-2 signaling pathway were also examined by Western blot.

Results

Both echocardiography and histological measurement showed an improvement in cardiac function and morphology. Biomarkers such as LDH, NT-proBNP, cTnT, and AST, as well as the inflammatory cytokines IL-1β, IL-6, and TNF-α, were decreased in plasma of mice receiving LC treatment after myocardial injury. In addition, the expression of α-SMA as well as the key proteins in the Bax/Bcl-2 signaling pathway in cardiac myocardium were much lower in mice with LC treatment compared to those without after MI.

Conclusions

Our data suggest that LC can effectively ameliorate left ventricular (LV) remodeling after MI, and its beneficial effects on myocardial function and remodeling may be attributable at least in part to anti-inflammatory and inhibition of the Bax/Bcl-2 apoptotic signaling pathway.

The Role of Glutamine and Glutaminase in Pulmonary Hypertension

Pulmonary hypertension (PH) refers to a clinical and pathophysiological syndrome in which pulmonary vascular resistance and pulmonary arterial pressure are increased due to structural or functional changes in pulmonary vasculature caused by a variety of etiologies and different pathogenic mechanisms. It is followed by the development of right heart failure and even death. In recent years, most studies have found that PH and cancer shared a complex common pathological metabolic disturbance, such as the shift from oxidative phosphorylation to glycolysis. During the shifting process, there is an upregulation of glutamine decomposition driven by glutaminase. However, the relationship between PH and glutamine hydrolysis, especially by glutaminase is yet unclear. This review aims to explore the special linking among glutamine hydrolysis, glutaminase and PH, so as to provide theoretical basis for clinical precision treatment in PH.

Animal models of pulmonary hypertension due to left heart disease

Pulmonary hypertension due to left heart disease (PH‐LHD) is regarded as the most prevalent form of pulmonary hypertension (PH). Indeed, PH is an independent risk factor and predicts adverse prognosis for patients with left heart disease (LHD). Clinically, there are no drugs or treatments that directly address PH‐LHD, and treatment of LHD alone will not also ameliorate PH. To target the underlying physiopathological alterations of PH‐LHD and to develop novel therapeutic approaches for this population, animal models that simulate the pathophysiology of PH‐LHD are required. There are several available models for PH‐LHD that have been successfully employed in rodents or large animals by artificially provoking an elevated pressure load on the left heart, which by transduction elicits an escalated pressure in pulmonary artery. In addition, metabolic derangement combined with aortic banding or vascular endothelial growth factor receptor antagonist is also currently applied to reproduce the phenotype of PH‐LHD. As of today, none of the animal models exactly recapitulates the condition of patients with PH‐LHD. Nevertheless, the selection of an appropriate animal model is essential in basic and translational studies of PH‐LHD. Therefore, this review will summarize the characteristics of each PH‐LHD animal model and discuss the advantages and limitations of the different models.