Vascular stiffness mechanoactivates YAP/TAZ-dependent glutaminolysis to drive pulmonary hypertension

Fluid Shear Stress-Regulated Vascular Remodeling: Past, Present, and Future

The vascular system remodels throughout life to ensure adequate perfusion of tissues as they grow, regress, or change metabolic activity. Angiogenesis, the sprouting of new blood vessels to expand the capillary network, versus regression, in which endothelial cells die or migrate away to remove unneeded capillaries, controls capillary density. In addition, upstream arteries adjust their diameters to optimize blood flow to downstream vascular beds, which is controlled primarily by vascular endothelial cells sensing fluid shear stress (FSS) from blood flow. Changes in capillary density and small artery tone lead to changes in the resistance of the vascular bed, which leads to changes in flow through the arteries that feed these small vessels. The resultant decreases or increases in FSS through these vessels then stimulate their inward or outward remodeling, respectively. This review summarizes our knowledge of endothelial FSS-dependent vascular remodeling, offering insights into potential therapeutic interventions. We first provide a historical overview, then discuss the concept of set point and mechanisms of low-FSS-mediated and high-FSS-mediated inward and outward remodeling. We then cover in vivo animal models, molecular mechanisms, and clinical implications. Understanding the mechanisms underlying physiological endothelial FSS-mediated vascular remodeling and their failure due to mutations or chronic inflammatory and metabolic stresses may lead to new therapeutic strategies to prevent or treat vascular diseases.

Therapeutic targets for pulmonary arterial hypertension: insights into the emerging landscape

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive, life-threatening disease driven by vascular remodeling, right ventricular (RV) dysfunction, and metabolic and inflammatory dysregulation. Current therapies primarily target vasodilation to relieve symptoms but do not reverse disease progression. The recent approval of sotatercept, which modulates BMP/TGF-β signaling, marks a shift toward anti-remodeling therapies. Building on this, recent preclinical advances have identified promising therapeutic targets and potentially disease-modifying treatments.

AREAS COVERED

This review synthesizes the evolving preclinical landscape of emerging PAH therapeutic targets and drugs, highlighting innovative approaches aimed at addressing the underlying mechanisms of disease progression. Additionally, we discuss novel therapeutic strategies under development.

EXPERT OPINION

Recent advances in PAH research have identified novel therapeutic targets beyond vasodilators, including modulation of BMP/TGF-β signaling, metabolic programs, epigenetics, cancer-related signaling, the extracellular matrix, and immune pathways, among others. Sotatercept represents a significant advance in therapies that go beyond vasodilation, and long-term safety, efficacy, and durability are being assessed. Future treatment strategies will focus on precision approaches, noninvasive technologies, and regenerative biology to improve outcomes and reverse vascular remodeling.

Female Fibroblast Activation Is Estrogen-Mediated in Sex-Specific 3D-Bioprinted Pulmonary Artery Adventitia Models

Pulmonary arterial hypertension (PAH) is a form of pulmonary vascular disease characterized by scarring of the small blood vessels that results in reduced blood flow and increased blood pressure in the lungs. Over time, this increase in blood pressure causes damage to the heart. Idiopathic (IPAH) impacts male and female patients differently, with female patients showing a higher disease susceptibility (4:1 female-to-male ratio) but experiencing longer survival rates postdiagnosis compared to male patients. This complex sex dimorphism is known as the estrogen paradox. Prior studies suggest that estrogen signaling may be pathologic in the pulmonary vasculature and protective in the heart, yet the mechanisms underlying these sex differences in IPAH remain unclear. Many previous studies of PAH relied on male cells or cells of undisclosed origin for in vitro modeling. Here, we present a dynamic, three-dimensional (3D)-bioprinted model incorporating cells and circulating sex hormones from female patients to specifically study how female patients respond to changes in microenvironmental stiffness and sex hormone signaling on the cellular level. Poly(ethylene glycol)-α methacrylate (PEGαMA)-based hydrogels containing female human pulmonary artery adventitia fibroblasts (hPAAFs) from IPAH or control donors were 3D bioprinted to mimic pulmonary artery adventitia. These biomaterials were initially soft, like healthy blood vessels, and then stiffened using light to mimic vessel scarring in PAH. These 3D-bioprinted models showed that stiffening the microenvironment around female IPAH hPAAFs led to hPAAF activation. On both the protein and gene-expression levels, cellular activation markers significantly increased in stiffened samples and were highest in IPAH patient-derived cells. Treatment with a selective estrogen receptor modulator, which is currently in clinical trials for IPAH treatment, reduced the expression of hPAAF activation markers, demonstrating that hPAAF activation is one pathologic response mediated by estrogen signaling in the vasculature. These results showed the utility of sex-specific, 3D-bioprinted pulmonary artery adventitia models for preclinical drug discovery and validation.

Endothelial cell metabolism in cardiovascular physiology and disease

Endothelial cells are multifunctional cells that form the inner layer of blood vessels and have a crucial role in vasoreactivity, angiogenesis, immunomodulation, nutrient uptake and coagulation. Endothelial cells have unique metabolism and are metabolically heterogeneous. The microenvironment and metabolism of endothelial cells contribute to endothelial cell heterogeneity and metabolic specialization. Endothelial cell dysfunction is an early event in the development of several cardiovascular diseases and has been shown, at least to some extent, to be driven by metabolic changes preceding the manifestation of clinical symptoms. Diabetes mellitus, hypertension, obesity and chronic kidney disease are all risk factors for cardiovascular disease. Changes in endothelial cell metabolism induced by these cardiometabolic stressors accelerate the accumulation of dysfunctional endothelial cells in tissues and the development of cardiovascular disease. In this Review, we discuss the diversity of metabolic programmes that control endothelial cell function in the cardiovascular system and how these metabolic programmes are perturbed in different cardiovascular diseases in a disease-specific manner. Finally, we discuss the potential and challenges of targeting endothelial cell metabolism for the treatment of cardiovascular diseases.

Emerging biomaterials and bio-nano interfaces in pulmonary hypertension therapy: transformative strategies for personalized treatment

Pulmonary hypertension (PH) is still an aggressive and progressive illness with vascular remodeling and right heart failure despite the therapeutic advances made in the recent past. Biomaterials offer an attractive route to break the current therapeutic paradigms by inducing vascular repair, facilitating drug targeting, and allowing dynamic regeneration of tissue. This review taking an integrated approach investigates the revolutionary role played by novel biomaterials and bio-nano interfaces in PH treatment. We classify and evaluate several classes of biomaterial platforms including natural polymers, scaffolds based on synthetic polymers, extracellular vesicles (EVs), and stimulus-responsive systems with an emphasis on both underlying mechanisms and clinical relevance. We further address the progress made in artificial intelligence (AI)-based biomaterials and in integrating multi-omics tools to provide patient-tailored therapy. We finally touch on the ongoing limitations and enumerate future directions required to take forward biomaterial-based therapies towards clinical reality.

GLS1-Mediated Redundancy in Glutamate Accelerates Arterial Calcification via Activating NMDAR/Ca2+/β-Catenin Pathway

Arterial calcification is a powerful predictor of both the events and mortality associated with cardiovascular diseases in chronic kidney disease (CKD) patients. GLS1 (glutaminase 1), a rate-limiting enzyme catalyzing the conversion of glutamine to glutamate, is disordered in various cardiovascular diseases. However, the potential interplay between GLS1-mediated glutamate production and arterial calcification remains poorly understood. Here, LC-MS/MS analysis of CKD patients' samples shows an abnormally elevated activity of GLS1, reflected by the increased glutamate/glutamine ratio. Moreover, GLS1 activity is positively correlated with arterial calcification progression, and its expression is upregulated in calcified arteries. Treatment with GLS1 inhibitors or knockdown of GLS1 alleviates osteogenic reprogramming. In contrast, glutamate administration boosts the development of arterial calcification. Mechanistically, GLS1 redundancy-regulated glutamate superfluity stimulates the activation of N-methyl-d-aspartate receptors (NMDAR), leading to Ca2+ influx and extracellular regulated protein kinases (ERK) phosphorylation, followed by the nuclear translocation of β-Catenin and acceleration of osteogenic reprogramming of vascular smooth muscle cells (VSMCs) in further. This research defines GLS1 as a key contributor to arterial calcification. Glutamate, a major product of GLS1-mediated glutamine metabolism, exerts a deleterious effect on arterial calcification by activating NMDAR and subsequently triggering Ca2+ influx, which in turn exacerbates β-Catenin-regulated osteogenic reprogramming in VSMCs.

Associations of Metabolites Related Salt Sensitivity of Blood Pressure and Essential Hypertension in Chinese Population: The EpiSS Study

BACKGROUND

Salt sensitivity of blood pressure (SSBP) is an important risk factor for essential hypertension and cardiovascular diseases, and its metabolic mechanisms remain poorly understood. This study aimed to identify SSBP-associated metabolic biomarkers and investigate their potential mediating role in the SSBP-hypertension pathophysiology.

METHODS

Based on the Systematic Epidemiological Study of Salt Sensitivity (EpiSS) conducted in 2014-2016, we performed a case-control study involving 54 matched pairs of participants classified as salt-sensitive or salt-resistant with targeted metabolomics detected. Multivariable logistic regression analyses were conducted to assess the metabolites associations with SSBP and hypertension. The diagnostic performance of the model was evaluated using the receiver operating characteristic curve (ROC) analysis yielded an area under the curve (AUC) value, sensitivity, and specificity. Furthermore, the potential mediating effects of targeted metabolites on the relationship between SSBP and essential hypertension were explored.

RESULTS

Three metabolites demonstrated significant SSBP associations: L-Glutamine (OR = 0.998; 95% CI: 0.997, 0.999), PC (16:1/14:0) (OR = 1.039; 95% CI: 1.003, 1.077), and ChE (22:4) (OR = 1.115; 95% CI: 1.002, 1.240). Among them, L-Glutamine demonstrated the highest diagnostic efficiency for SSBP (AUC = 0.766; 95% CI: 0.677, 0.855). The combined model of the three metabolites slightly improved diagnostic efficiency (AUC = 0.788; 95% CI: 0.703, 0.874). L-Glutamine and Cer (d18:0/24:1) were identified as potential protective factors against essential hypertension (p < 0.05). Mediation analyses further indicated that L-Glutamine partially mediated the relationship between SSBP and essential hypertension, demonstrating a suppressive effect.

CONCLUSIONS

This study identified L-Glutamine as both a diagnostic biomarker for SSBP and a metabolic modulator attenuating hypertension risk, providing insights for early SSBP screening and the pathways governing SSBP progression to overt hypertension.

Inhibition of glutaminase 1 reduces M1 macrophage polarization to protect against monocrotaline-induced pulmonary arterial hypertension

(1) BACKGROUND: Metabolic abnormalities and immune inflammation are key elements within pathogenesis of pulmonary arterial hypertension (PAH). And in PAH patients, aberrant glutamine metabolism has been observed; however, the function of glutaminase 1 (GLS1) in macrophage is still unknown. So we aims to investigate GLS1's impact upon macrophages in PAH. (2) METHODS: We firstly constructed an monocrotaline (MCT)-induced PAH rat model. Briefly, the PAH rats were treated with the GLS1 inhibitor BPTES, and various index were evaluated, including hemodynamics, right ventricular function, pulmonary vascular remodeling, macrophage markers, and glutamine metabolism. After that, we polarized bone marrow-derived macrophages (BMDMs) into M1 phenotype and then subjected to BPTES intervention. Finally, we assessed macrophage phenotype, inflammatory markers, and glutamine metabolism indicators, along with the impact of BMDM supernatant on the behavior of pulmonary arterial smooth muscle cells (PASMCs). (3) RESULTS: GLS1 was significantly upregulated in both PAH patients and rats. Treatment with the GLS1 inhibitor BPTES markedly improved pulmonary arterial pressure, right ventricular function, and pulmonary vascular remodeling in PAH rats, while inhibiting M1 macrophage polarization, NLRP3 activation, and the release of pro-inflammatory cytokines. This, in turn, alleviated the proliferation and migration of PASMCs induced by inflammatory stimuli. (4) CONCLUSION: We propose that targeting GLS1 to reduce M1 macrophage polarization and inflammatory responses may represent a promising therapeutic approach for PAH.

The Role of Hydrogen Sulfide in the Regulation of the Pulmonary Vasculature in Health and Disease

The gasotransmitter hydrogen sulfide (H2S; also termed sulfide) generally acts as a vasodilator in the systemic vasculature but causes a paradoxical constriction of pulmonary arteries (PAs). In light of evidence that a fall in the partial pressure in oxygen (pO2) increases cellular sulfide levels, it was proposed that a rise in sulfide in pulmonary artery smooth muscle cells (PASMCs) is responsible for hypoxic pulmonary vasoconstriction, the contraction of PAs which develops rapidly in lung regions undergoing alveolar hypoxia. In contrast, pulmonary hypertension (PH), a sustained elevation of pulmonary artery pressure (PAP) which can develop in the presence of a diverse array of pathological stimuli, including chronic hypoxia, is associated with a decrease in the expression of sulfide -producing enzymes in PASMCs and a corresponding fall in sulfide production by the lung. Evidence that PAP in animal models of PH can be lowered by administration of exogenous sulfide has led to an interest in using sulfide-donating agents for treating this condition in humans. Notably, intracellular H2S exists in equilibrium with other sulfur-containing species such as polysulfides and persulfides, and it is these reactive sulfur species which are thought to mediate most of its effects on cells through persulfidation of cysteine thiols on proteins, leading to changes in function in a manner similar to thiol oxidation by reactive oxygen species. This review sets out what is currently known about the mechanisms by which H2S and related sulfur species exert their actions on pulmonary vascular tone, both acutely and chronically, and discusses the potential of sulfide-releasing drugs as treatments for the different types of PH which arise in humans.

The role of lactate metabolism and lactylation in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a complex and progressive disease characterized by elevated pulmonary artery pressure and vascular remodeling. Recent studies have underscored the pivotal role of metabolic dysregulation and epigenetic modifications in the pathogenesis of PAH. Lactate, a byproduct of glycolysis, is now recognized as a key molecule that links cellular metabolism with activity regulation. Recent findings indicate that, in addition to altered glycolytic activity and dysregulated. Lactate homeostasis and lactylation-a novel epigenetic modification-also play a significant role in the development of PAH. This review synthesizes current knowledge regarding the relationship between altered glycolytic activity and PAH, with a particular focus on the cumulative effects of lactate in pulmonary vascular cells. Furthermore, lactylation, an emerging epigenetic modification, is discussed in the context of PAH. By elucidating the complex interplay between lactate metabolism and lactylation in PAH, this review aims to provide insights into potential therapeutic targets. Understanding these metabolic pathways may lead to innovative strategies for managing PAH and improving patient outcomes. Future research should focus on the underlying mechanisms through which lactylation influences the pathophysiology of PAH, thereby aiding in the development of targeted interventions.

The (un)known crosstalk between metabolism and mechanotransduction: Implications for metabolic syndrome (MetS)-associated neurological complications

Metabolic syndrome (MetS) has been associated with disruptions in tissue mechanical homeostasis and inflammatory and metabolic derangements. However, the direct correlation between metabolic alterations and changes in tissue stiffness, and whether they could play a role as upstream initiators of disease pathology remains to be investigated. This emerging concept has yet to be put into clinical practice as many questions concerning the interplay between extracellular matrix mechanical properties and regulation of metabolic pathways remain unsolved. This review will highlight key foundational studies examining mutual regulation of cell metabolism and mechanotransduction, and opening questions lying ahead for better understanding MetS pathophysiology.

The Role of Yes-Associated Protein in Inflammatory Diseases and Cancer

Yes-associated protein (YAP) plays a central role in the Hippo pathway, primarily governing cell proliferation, differentiation, and apoptosis. Its significance extends to tumorigenesis and inflammatory conditions, impacting disease initiation and progression. Given the increasing relevance of YAP in inflammatory disorders and cancer, this study aims to elucidate its pathological regulatory functions in these contexts. Specifically, we aim to investigate the involvement and molecular mechanisms of YAP in various inflammatory diseases and cancers. We particularly focus on how YAP activation, whether through Hippo-dependent or independent pathways, triggers the release of inflammation and inflammatory mediators in respiratory, cardiovascular, and digestive inflammatory conditions. In cancer, YAP not only promotes tumor cell proliferation and differentiation but also modulates the tumor immune microenvironment, thereby fostering tumor metastasis and progression. Additionally, we provide an overview of current YAP-targeted therapies. By emphasizing YAP's role in inflammatory diseases and cancer, this study aims to enhance our understanding of the protein's pivotal involvement in disease processes, elucidate the intricate pathological mechanisms of related diseases, and contribute to future drug development strategies targeting YAP.

Matrix stiffness regulates nucleus pulposus cell glycolysis by MRTF-A-dependent mechanotransduction

Increased matrix stiffness of nucleus pulposus (NP) tissue is a main feature of intervertebral disc degeneration (IVDD) and affects various functions of nucleus pulposus cells (NPCs). Glycolysis is the main energy source for NPC survival, but the effects and underlying mechanisms of increased extracellular matrix (ECM) stiffness on NPC glycolysis remain unknown. In this study, hydrogels with different stiffness were established to mimic the mechanical environment of NPCs. Notably, increased matrix stiffness in degenerated NP tissues from IVDD patients was accompanied with impaired glycolysis, and NPCs cultured on rigid substrates exhibited a reduction in glycolysis. Meanwhile, RNA sequencing analysis showed altered cytoskeleton-related gene expression in NPCs on rigid substrates. Myocardin-related transcription factor A (MRTF-A) is a transcriptional coactivator in mechanotransduction mainly responding to cytoskeleton remodeling, which was activated and translocated to the nucleus under rigid substrate and was upregulated during IVDD progression. Furthermore, gas chromatography-mass spectrometry (GC-MS) analysis revealed that MRTF-A overexpression reduced NPC glycolytic metabolite abundance and identified a correlation with AMPK pathway. Mechanistically, rigid substrates and MRTF-A overexpression inhibited Kidins220 expression and AMPK phosphorylation in NPCs, whereas MRTF-A inhibition, treated with the MRTF-A inhibitor CCG, partially rescued NP tissue degeneration and glycolytic enzyme expression. Our data demonstrate that MRTF-A is a critical regulator that responds to increased matrix stiffness in IVDD, and MRTF-A activation reduces NPC glycolysis by down-regulating Kidins220 and inhibiting AMPK phosphorylation.

Croix CM, Stolz DB, Lee JY, Cheng MH, Zhang M, Detmer S, Guzman E, Manan RS, Saggar R, Haley KJ, Waxman AB, Okawa S, Schwantes-An TH, Pauciulo MW, Wang B, Webb A, Chauvet C, Anderson DG, Nichols WC, Desai AA, Lafyatis R, Nouraie SM, Wu H, McDonald JG, Cheng S, Bahar I, Bertero T, Benza RL, Jain M, Chan SY. Lysosomal dysfunction and inflammatory sterol metabolism in pulmonary arterial hypertension

Vascular inflammation regulates endothelial pathophenotypes, particularly in pulmonary arterial hypertension (PAH). Dysregulated lysosomal activity and cholesterol metabolism activate pathogenic inflammation, but their relevance to PAH is unclear. Nuclear receptor coactivator 7 (NCOA7) deficiency in endothelium produced an oxysterol and bile acid signature through lysosomal dysregulation, promoting endothelial pathophenotypes. This oxysterol signature overlapped with a plasma metabolite signature associated with human PAH mortality. Mice deficient for endothelial Ncoa7 or exposed to an inflammatory bile acid developed worsened PAH. Genetic predisposition to NCOA7 deficiency was driven by single-nucleotide polymorphism rs11154337, which alters endothelial immunoactivation and is associated with human PAH mortality. An NCOA7-activating agent reversed endothelial immunoactivation and rodent PAH. Thus, we established a genetic and metabolic paradigm that links lysosomal biology and oxysterol processes to endothelial inflammation and PAH.

Mechano-dependent sorbitol accumulation supports biomolecular condensate

Condensed droplets of protein regulate many cellular functions, yet the physiological conditions regulating their formation remain largely unexplored. Increasing our understanding of these mechanisms is paramount, as failure to control condensate formation and dynamics can lead to many diseases. Here, we provide evidence that matrix stiffening promotes biomolecular condensation in vivo. We demonstrate that the extracellular matrix links mechanical cues with the control of glucose metabolism to sorbitol. In turn, sorbitol acts as a natural crowding agent to promote biomolecular condensation. Using in silico simulations and in vitro assays, we establish that variations in the physiological range of sorbitol concentrations, but not glucose concentrations, are sufficient to regulate biomolecular condensates. Accordingly, pharmacological and genetic manipulation of intracellular sorbitol concentration modulates biomolecular condensates in breast cancer-a mechano-dependent disease. We propose that sorbitol is a mechanosensitive metabolite enabling protein condensation to control mechano-regulated cellular functions.

Female fibroblast activation is estrogen-mediated in sex-specific 3D-bioprinted pulmonary artery adventitia models

Pulmonary arterial hypertension (PAH) impacts male and female patients in different ways. Female patients exhibit a greater susceptibility to disease (4:1 female-to-male ratio) but live longer after diagnosis than male patients. This complex sexual dimorphism is known as the estrogen paradox. Prior studies suggest that estrogen signaling may be pathologic in the pulmonary vasculature and protective in the heart, yet the mechanisms underlying these sex-differences in PAH remain unclear. PAH is a form of a pulmonary vascular disease that results in scarring of the small blood vessels, leading to impaired blood flow and increased blood pressure. Over time, this increase in blood pressure causes damage to the heart. Many previous studies of PAH relied on male cells or cells of undisclosed origin for in vitro modeling. Here we present a dynamic, 3D-bioprinted model that incorporates cells and circulating sex hormones from female patients to specifically study how female patients respond to changes in microenvironmental stiffness and sex hormone signaling. Poly(ethylene glycol)-alpha methacrylate (PEGαMA)-based hydrogels containing female human pulmonary artery adventitia fibroblasts (hPAAFs) from idiopathic PAH (IPAH) or control donors were 3D bioprinted to mimic pulmonary artery adventitia. These biomaterials were initially soft, like healthy blood vessels, and then stiffened using light to mimic vessel scarring in PAH. These 3D-bioprinted models showed that stiffening the microenvironment around female IPAH hPAAFs led to hPAAF activation. On both the protein and gene-expression levels, cellular activation markers significantly increased in stiffened samples and were highest in IPAH patient-derived cells. Treatment with a selective estrogen receptor modulator reduced expression hPAAF activation markers, demonstrating that hPAAF activation is a one pathologic response mediated by estrogen signaling in the vasculature, validating that drugs currently in clinical trials could be evaluated in sex-specific 3D-bioprinted pulmonary artery adventitia models.

Glutamine metabolism is systemically different between primary and induced pluripotent stem cell-derived brain microvascular endothelial cells

Human primary (hpBMEC) and induced pluripotent stem cell (iPSC)-derived brain microvascular endothelial-like cells (hiBMEC) are interchangeably used in blood-brain barrier models to study neurological diseases and drug delivery. Both hpBMEC and hiBMEC use glutamine as a source of carbon and nitrogen to produce metabolites and build proteins essential to cell function and communication. We used metabolomic, transcriptomic, and computational methods to examine how hpBMEC and hiBMEC metabolize glutamine, which may impact their utility in modeling the blood-brain barrier. We found that glutamine metabolism was systemically different between the two cell types. hpBMEC had a higher metabolic rate and produced more glutamate and GABA, while hiBMEC rerouted glutamine to produce more glutathione, fatty acids, and asparagine. Higher glutathione production in hiBMEC correlated with higher oxidative stress compared to hpBMEC. α-ketoglutarate (α-KG) supplementation increased glutamate secretion from hiBMEC to match that of hpBMEC; however, α-KG also decreased hiBMEC glycolytic rate. These fundamental metabolic differences between BMEC types may impact in vitro blood-brain barrier model function, particularly communication between BMEC and surrounding cells, and emphasize the importance of evaluating the metabolic impacts of iPSC-derived cells in disease models.

Positive feedback between arginine methylation of YAP and methionine transporter SLC43A2 drives anticancer drug resistance

Yes-associated protein (YAP) activation confers resistance to chemotherapy and targeted therapy. Methionine participates in cellular processes by converting to methyl donor for the methylation of DNA, RNA and protein. However, it remains unclear whether methionine affects drug resistance by influencing YAP activity. In this study, we report that methionine deprivation remarkably suppresses the transcriptional activity of YAP-TEAD in cancer cells. Methionine promotes PRMT1-catalyzed asymmetric dimethylation at R124 of YAP (YAP R124me2a). Mimicking of YAP methylation abolishes the reduction effect of methionine-restricted diet on YAP-induced drug resistance. YAP activates the transcription of SLC43A2, the methionine transporter, to increase methionine uptake in cancer cells. Knockdown of SLC43A2 decreases the level of YAP R124me2a. BCH, the inhibitor of SLC43A2, sensitizes tumors to anticancer drugs. Thus, our results unravel the positive feedback between YAP R124 methylation and SLC43A2 that contributes to anticancer drug resistance. Disrupting this positive feedback could be a potential strategy for cancer therapy.

Exploring Novel Therapeutics for Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by progressive obliteration of pulmonary arteries. Dysregulated bone morphogenetic protein (BMP) signaling pathway contributes to the development of PAH, and pulmonary vasodilators including endothelin receptor antagonists, phosphodiesterase 5 inhibitors, prostaglandins and soluble guanylate cyclase stimulators, dramatically improve the long-term prognosis. However, there still exist refractory patients who require continuous catecholamine support or lung transplantation, and the development of new treatment strategies targeting molecular mechanisms of PAH is highly anticipated. Sotatercept, a first-in-class activin signaling inhibitor, has recently been approved for the treatment of PAH, and it targets and restores an imbalance in activin-growth differentiation factor and BMP pathway signaling. In addition, treatment strategies targeting peroxisome proliferator-activated receptor-γ signaling, inflammatory and immune systems, DNA damage response and cellular senescence, and growth factor receptors including vascular endothelial growth factor and platelet-derived growth factor receptors, are being devised. In this review, we briefly summarize the recent advances in basic research paving the way for the development of more effective treatments for PAH and their potential in clinical therapeutic applications.

The Masquelet technique triggers the formation of a network involving LncRNA, circRNA, miRNA, and mRNA during bone repair

BACKGROUND

The ceRNA network, which is competitive endogenous RNA, uncovers a fresh mechanism of RNA interaction and holds significant importance in diverse biological processes. The aim of this study is to investigate the molecular process of induced membrane (IM) formation in bone defects using the Masquelet's induced membrane technique (MIMT), in order to offer novel insights and a theoretical foundation for enhancing the treatment of bone defects with MIMT.

METHODS

In this work, we identified differentially expressed mRNAs (DEGs), lncRNAs (DELs), circRNAs (DECs), and miRNAs (DEMs). To explore the primary functions of the shared DEGs, we utilized Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Next, predictions were made for lncRNA-miRNA and miRNA-mRNA interactions, and the Cytoscape software was utilized to construct the regulatory network for ceRNA.

RESULTS

By integrating GO and KEGG enrichment analysis, a total of 385 differentially expressed genes (DEGs) were discovered in the samples from the MIMT-treated group. Additionally, after re-annotating the probes and intersecting two sets of differently expressed miRNAs, 1304 differentially expressed lncRNAs (DELs) and 23 differentially expressed circRNAs (DECs) were identified. Furthermore, 13 differentially expressed miRNAs (DEMs) were obtained. Moreover, utilizing the anticipated objectives of DEMs, we acquired 1203 pairs of lncRNA-miRNA-mRNA interactors (comprising 24 lncRNAs, 10 miRNAs, and 115 mRNAs) and 250 pairs of circRNA-miRNA-mRNA interactions (comprising 7 circRNAs, 9 miRNAs, and 115 mRNAs). CEBPA, DGAT2, CDKN1A, PLIN2, and CIDEC were identified as the five hub proteins in the PPI network. LncRNA/circRNA-hsa-miR-671-5p could potentially regulate the primary central protein, CEBPA.

CONCLUSIONS

In this study, we described the potential regulatory mechanism of the MIMT in treating bone defects. We proposed a new lncRNA-miRNA-mRNA ceRNA network that could help further explore the molecular mechanisms of bone repair.

YAP/TAZ as mechanobiological signaling pathway in cardiovascular physiological regulation and pathogenesis

Cardiovascular diseases (CVDs) persistently rank as a leading cause of premature death and illness worldwide. The Hippo signaling pathway, known for its highly conserved nature and integral role in regulating organ size, tissue homeostasis, and stem cell function, has been identified as a critical factor in the pathogenesis of CVDs. Recent findings underscore the significance of the Yes-associated protein (YAP) and the Transcriptional Coactivator with PDZ-binding motif (TAZ), collectively referred to as YAP/TAZ. These proteins play pivotal roles as downstream components of the Hippo pathway, in the regulation of cardiovascular development and homeostasis. YAP/TAZ can regulate various cellular processes such as cell proliferation, migration, differentiation, and apoptosis through their interactions with transcription factors, particularly those within the transcriptional enhancer associate domain (TEAD) family. The aim of this review is to provide a comprehensive overview of the current understanding of YAP/TAZ signaling in cardiovascular physiology and pathogenesis. We analyze the regulatory mechanisms of YAP/TAZ activation, explore their downstream effectors, and examine their association across numerous cardiovascular disorders, including myocardial hypertrophy, myocardial infarction, pulmonary hypertension, myocardial ischemia-reperfusion injury, atherosclerosis, angiogenesis, restenosis, and cardiac fibrosis. Furthermore, we investigate the potential therapeutic implications of targeting the YAP/TAZ pathway for the treatment of CVDs. Through this comprehensive review, our aim is to elucidate the current understanding of YAP/TAZ signaling in cardiovascular biology and underscore its potential implications for the diagnosis and therapeutic intervention of CVDs.

Ferroptosis-Mediated Inflammation Promotes Pulmonary Hypertension

BACKGROUND

Mitochondrial dysfunction, characterized by impaired lipid metabolism and heightened reactive oxygen species generation, results in lipid peroxidation and ferroptosis. Ferroptosis is an inflammatory mode of cell death that promotes complement activation and macrophage recruitment. In pulmonary arterial hypertension (PAH), pulmonary arterial endothelial cells exhibit cellular phenotypes that promote ferroptosis. Moreover, there is ectopic complement deposition and inflammatory macrophage accumulation in the pulmonary vasculature. However, the effects of ferroptosis inhibition on these pathogenic mechanisms and the cellular landscape of the pulmonary vasculature are incompletely defined.

METHODS

Multiomics and physiological analyses evaluated how ferroptosis inhibition-modulated preclinical PAH. The impact of adeno-associated virus 1-mediated expression of the proferroptotic protein ACSL (acyl-CoA synthetase long-chain family member) 4 on PAH was determined, and a genetic association study in humans further probed the relationship between ferroptosis and pulmonary hypertension.

RESULTS

Ferrostatin-1, a small-molecule ferroptosis inhibitor, mitigated PAH severity in monocrotaline rats. RNA-sequencing and proteomics analyses demonstrated ferroptosis was associated with PAH severity. RNA-sequencing, proteomics, and confocal microscopy revealed complement activation and proinflammatory cytokines/chemokines were suppressed by ferrostatin-1. In addition, ferrostatin-1 combatted changes in endothelial, smooth muscle, and interstitial macrophage abundance and gene activation patterns as revealed by deconvolution RNA-sequencing. Ferroptotic pulmonary arterial endothelial cell damage-associated molecular patterns restructured the transcriptomic signature and mitochondrial morphology, promoted the proliferation of pulmonary artery smooth muscle cells, and created a proinflammatory phenotype in monocytes in vitro. Adeno-associated virus 1-Acsl4 induced an inflammatory PAH phenotype in rats. Finally, single-nucleotide polymorphisms in 6 ferroptosis genes identified a potential link between ferroptosis and pulmonary hypertension severity in the Vanderbilt BioVU repository.

CONCLUSIONS

Ferroptosis promotes PAH through metabolic and inflammatory mechanisms in the pulmonary vasculature.

Precision Cut Lung Slices: Emerging Tools for Preclinical and Translational Lung Research. An Official American Thoracic Society Workshop Report

The urgent need for effective treatments for acute and chronic lung diseases underscores the significance of developing innovative preclinical human research tools. The 2023 ATS Workshop on Precision Cut Lung Slices (PCLS) brought together 35 experts to discuss and address the role of human tissue-derived PCLS as a unique tool for target and drug discovery and validation in pulmonary medicine. With increasing interest and usage, along with advancements in methods and technology, there is a growing need for consensus on PCLS methodology and readouts. The current document recommends standard reporting criteria and emphasizes the requirement for careful collection and integration of clinical metadata. We further discuss current clinically relevant readouts that can be applied to PCLS and highlight recent developments and future steps for implementing novel technologies for PCLS modeling and analysis. The collection and correlation of clinical metadata and multiomic analysis will further advent the integration of this preclinical platform into patient endotyping and the development of tailored therapies for lung disease patients.

Metabolic Responses to Redox Stress in Vascular Cells

Significance: Redox stress underlies numerous vascular disease mechanisms. Metabolic adaptability is essential for vascular cells to preserve energy and redox homeostasis. Recent Advances: Single-cell technologies and multiomic studies demonstrate significant metabolic heterogeneity among vascular cells in health and disease. Increasing evidence shows that reductive or oxidative stress can induce metabolic reprogramming of vascular cells. A recent example is intracellular L-2-hydroxyglutarate accumulation in response to hypoxic reductive stress, which attenuates the glucose flux through glycolysis and mitochondrial respiration in pulmonary vascular cells and provides protection against further reductive stress. Critical Issues: Regulation of cellular redox homeostasis is highly compartmentalized and complex. Vascular cells rely on multiple metabolic pathways, but the precise connectivity among these pathways and their regulatory mechanisms is only partially defined. There is also a critical need to understand better the cross-regulatory mechanisms between the redox system and metabolic pathways as perturbations in either systems or their cross talk can be detrimental. Future Directions: Future studies are needed to define further how multiple metabolic pathways are wired in vascular cells individually and as a network of closely intertwined processes given that a perturbation in one metabolic compartment often affects others. There also needs to be a comprehensive understanding of how different types of redox perturbations are sensed by and regulate different cellular metabolic pathways with specific attention to subcellular compartmentalization. Lastly, integration of dynamic changes occurring in multiple metabolic pathways and their cross talk with the redox system is an important goal in this multiomics era. Antioxid. Redox Signal. 41,793-817.

RUNX2 is stabilised by TAZ and drives pulmonary artery calcification and lung vascular remodelling in pulmonary hypertension due to left heart disease

BACKGROUND

Calcification is common in chronic vascular disease, yet its role in pulmonary hypertension due to left heart disease is unknown. Here, we probed for the role of runt-related transcription factor-2 (RUNX2), a master transcription factor in osteogenesis, and its regulation by the HIPPO pathway transcriptional coactivator with PDZ-binding motif (TAZ) in the osteogenic reprogramming of pulmonary artery smooth muscle cells and vascular calcification in patients with pulmonary hypertension due to left heart disease. We similarly examined its role using an established rat model of pulmonary hypertension due to left heart disease induced by supracoronary aortic banding.

METHODS

Pulmonary artery samples were collected from patients and rats with pulmonary hypertension due to left heart disease. Genome-wide RNA sequencing was performed, and pulmonary artery calcification assessed. Osteogenic signalling via TAZ and RUNX2 was delineated by protein biochemistry. In vivo, the therapeutic potential of RUNX2 or TAZ inhibition by CADD522 or verteporfin was tested in the rat model.

RESULTS

Gene ontology term analysis identified significant enrichment in ossification and osteoblast differentiation genes, including RUNX2, in pulmonary arteries of patients and lungs of rats with pulmonary hypertension due to left heart disease. Pulmonary artery calcification was evident in both patients and rats. Both TAZ and RUNX2 were upregulated and activated in pulmonary artery smooth muscle cells of patients and rats. Co-immunoprecipitation revealed a direct interaction of RUNX2 with TAZ in pulmonary artery smooth muscle cells. TAZ inhibition or knockdown decreased RUNX2 abundance due to accelerated RUNX2 protein degradation rather than reduced de novo synthesis. Inhibition of either TAZ or RUNX2 attenuated pulmonary artery calcification, distal lung vascular remodelling and pulmonary hypertension development in the rat model.

CONCLUSION

Pulmonary hypertension due to left heart disease is associated with pulmonary artery calcification that is driven by TAZ-dependent stabilisation of RUNX2, causing osteogenic reprogramming of pulmonary artery smooth muscle cells. The TAZ-RUNX2 axis may present a therapeutic target in pulmonary hypertension due to left heart disease.

Selenium supplementation elevated SELENBP1 to inhibit fibroblast activation in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening disease induced by abnormal activation of pulmonary adventitial fibroblasts (PAFs) in the early stage. The association between selenium deficiency and PAH is not yet fully understood. In this study, we found that the serum selenium content of PAH patients was significantly lower than that of healthy volunteers in two independent cohorts. Moreover, PAH patients with lower selenium levels may present poorer prognosis. Prophylactic selenium supplementation could effectively improve hemodynamics and pulmonary vascular remodeling in monocrotaline-induced pulmonary hypertension rat models. Mechanistically, selenium supplementation restored the level of selenium binding protein 1 (SELENBP1) which could exert an antagonistic effect on PAF activation. The rescue assay further proved that selenium supplementation worked in a SELENBP1-dependent manner. These findings demonstrated that selenium deficiency is an important risk factor in PAH, and the selenium-SELENBP1 axis represents a promising target for PAH prevention.

Insights into Metabolic Reprogramming in Tumor Evolution and Therapy

Background: Cancer remains a global health challenge, characterized not just by uncontrolled cell proliferation but also by the complex metabolic reprogramming that underlies its development and progression. Objectives: This review delves into the intricate relationship between cancer and its metabolic alterations, drawing an innovative comparison with the cosmological concepts of dark matter and dark energy to highlight the pivotal yet often overlooked role of metabolic reprogramming in tumor evolution. Methods: It scrutinizes the Warburg effect and other metabolic adaptations, such as shifts in lipid synthesis, amino acid turnover, and mitochondrial function, driven by mutations in key regulatory genes. Results: This review emphasizes the significance of targeting these metabolic pathways for therapeutic intervention, outlining the potential to disrupt cancer's energy supply and signaling mechanisms. It calls for an interdisciplinary research approach to fully understand and exploit the intricacies of cancer metabolism, pointing toward metabolic reprogramming as a promising frontier for developing more effective cancer treatments. Conclusion: By equating cancer's metabolic complexity with the enigmatic nature of dark matter and energy, this review underscores the critical need for innovative strategies in oncology, highlighting the importance of unveiling and targeting the "dark energy" within cancer cells to revolutionize future therapy and research.

Viewing Pulmonary Arterial Hypertension Pathogenesis and Opportunities for Disease-Modifying Therapy Through the Lens of Biomass

Fibroproliferative remodeling of distal pulmonary arterioles is a cornerstone characteristic of pulmonary arterial hypertension (PAH). Data from contemporary quantitative imaging suggest that anabolic synthesis of macromolecular substrate, defined here as biomass, is the proximate event that causes vascular remodeling via pathogenic changes to DNA, collagen, cytoskeleton, and lipid membranes. Modifying biomass is achievable but requires tilting the balance in favor of endogenous degradation over synthetic pathways in order to advance the first-ever disease-modifying PAH pharmacotherapy. Viewing PAH pathobiology through the lens of biomass represents an opportunity to decipher novel determinants of disease inception and inform interventions that induce reverse remodeling.

Disrupting YAP1-mediated glutamine metabolism induces synthetic lethality alongside ODC1 inhibition in osteosarcoma

PURPOSE

Osteosarcoma, a highly malignant primary bone tumor primarily affecting adolescents, frequently develops resistance to initial chemotherapy, leading to metastasis and limited treatment options. Our study aims to uncover novel therapeutic targets for metastatic and recurrent osteosarcoma.

METHODS

In this study, we proved the potential of modulating the YAP1-regulated glutamine metabolic pathway to augment the response of OS to DFMO. We initially employed single-cell transcriptomic data to gauge the activation level of polyamine metabolism in MTAP-deleted OS patients. This was further substantiated by transcriptome sequencing data from recurrent and non-recurrent patient tissues, confirming the activation of polyamine metabolism in progressive OS. Through high-throughput drug screening, we pinpointed CIL56, a YAP1 inhibitor, as a promising candidate for a combined therapeutic strategy with DFMO. In vivo, we utilized PDX and CDX models to validate the therapeutic efficacy of this drug combination. In vitro, we conducted western blot analysis, qPCR analysis, immunofluorescence staining, and PuMA experiments to monitor alterations in molecular expression, distribution, and tumor metastasis capability. We employed CCK-8 and colony formation assays to assess the proliferative capacity of cells in the experimental group. We used flow cytometry and reactive oxygen probes to observe changes in ROS and glutamine metabolism within the cells. Finally, we applied RNA-seq in tandem with metabolomics to identify metabolic alterations in OS cells treated with a DFMO and CIL56 combination. This enabled us to intervene and validate the role of the YAP1-mediated glutamine metabolic pathway in DFMO resistance.

RESULTS

Through single-cell RNA-seq data analysis, we pinpointed a subset of late-stage OS cells with significantly upregulated polyamine metabolism. This upregulation was further substantiated by transcriptomic profiling of recurrent and non-recurrent OS tissues. High-throughput drug screening revealed a promising combination strategy involving DFMO and CIL56. DFMO treatment curbs the phosphorylation of YAP1 protein in OS cells, promoting nuclear entry and initiating the YAP1-mediated glutamine metabolic pathway. This reduces intracellular ROS levels, countering DFMO's anticancer effect. The therapeutic efficacy of DFMO can be amplified both in vivo and in vitro by combining it with the YAP1 inhibitor CIL56 or the glutaminase inhibitor CB-839. This underscores the significant potential of targeting the YAP1-mediated glutamine metabolic pathway to enhance efficacy of DFMO.

CONCLUSION

Our findings elucidate YAP1-mediated glutamine metabolism as a crucial bypass mechanism against DFMO, following the inhibition of polyamine metabolism. Our study provides valuable insights into the potential role of DFMO in an "One-two Punch" therapy of metastatic and recurrent osteosarcoma.

Effect of dapagliflozin on pulmonary vascular remodeling in rats with chronic hypoxic pulmonary arterial hypertension

OBJECTIVE

To investigate the effects of sodium-glucose co-transporter 2 inhibitor dapagliflozin on pulmonary vascular remodeling in a rat model of chronic hypoxic pulmonary arterial hypertension.

METHODS

Eighteen female Sprague-Dawley rats were divided into three groups: control (CON), chronic hypoxia (HYP), and chronic hypoxia + dapagliflozin. The HYP and dapagliflozin groups were subjected to hypoxia and received saline or dapagliflozin. The CON group was normoxic and received saline. Body weight and fasting blood glucose were measured, and after 21 days, lung and heart tissues were analyzed for pulmonary artery reconstruction and right ventricular hypertrophy. Western blotting assessed Bax and Bcl-2 protein levels.

RESULTS

Chronic hypoxia increased pulmonary artery wall thickness and lung fibrosis and caused right ventricular hypertrophy. Dapagliflozin reduced these changes, decreasing artery wall thickness, fibrosis, and hypertrophy while increasing the Bax/Bcl-2 ratio.

CONCLUSION

Dapagliflozin alleviates chronic hypoxia-induced pulmonary artery wall thickening and lung tissue fibrosis in rats, potentially through proapoptotic effects.

YAP/TAZ Signaling in the Pathobiology of Pulmonary Fibrosis

Pulmonary fibrosis (PF) is a severe, irreversible lung disease characterized by progressive scarring, with idiopathic pulmonary fibrosis (IPF) being the most prevalent form. IPF's pathogenesis involves repetitive lung epithelial injury leading to fibroblast activation and excessive extracellular matrix (ECM) deposition. The prognosis for IPF is poor, with limited therapeutic options like nintedanib and pirfenidone offering only modest benefits. Emerging research highlights the dysregulation of the yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) signaling pathway as a critical factor in PF. YAP and TAZ, components of the Hippo pathway, play significant roles in cell proliferation, differentiation, and fibrosis by modulating gene expression through interactions with TEA domain (TEAD) transcription factors. The aberrant activation of YAP/TAZ in lung tissue promotes fibroblast activation and ECM accumulation. Targeting the YAP/TAZ pathway offers a promising therapeutic avenue. Preclinical studies have identified potential treatments, such as trigonelline, dopamine receptor D1 (DRD1) agonists, and statins, which inhibit YAP/TAZ activity and demonstrate antifibrotic effects. These findings underscore the importance of YAP/TAZ in PF pathogenesis and the potential of novel therapies aimed at this pathway, suggesting a new direction for improving IPF treatment outcomes. Further research is needed to validate these approaches and translate them into clinical practice.

Skeletal Muscle SIRT3 Deficiency Contributes to Pulmonary Vascular Remodeling in Pulmonary Hypertension Due to Heart Failure With Preserved Ejection Fraction

BACKGROUND

Pulmonary hypertension (PH) is a major complication linked to adverse outcomes in heart failure with preserved ejection fraction (HFpEF), yet no specific therapies exist for PH associated with HFpEF (PH-HFpEF). We have recently reported on the role of skeletal muscle SIRT3 (sirtuin-3) in modulation of PH-HFpEF, suggesting a novel endocrine signaling pathway for skeletal muscle modulation of pulmonary vascular remodeling.

METHODS

Using skeletal muscle-specific Sirt3 knockout mice (Sirt3skm-/-) and mass spectrometry-based comparative secretome analysis, we attempted to define the processes by which skeletal muscle SIRT3 defects affect pulmonary vascular health in PH-HFpEF.

RESULTS

Sirt3skm-/- mice exhibited reduced pulmonary vascular density accompanied by pulmonary vascular proliferative remodeling and elevated pulmonary pressures. Comparative analysis of secretome by mass spectrometry revealed elevated secretion levels of LOXL2 (lysyl oxidase homolog 2) in SIRT3-deficient skeletal muscle cells. Elevated circulation and protein expression levels of LOXL2 were also observed in plasma and skeletal muscle of Sirt3skm-/- mice, a rat model of PH-HFpEF, and humans with PH-HFpEF. In addition, expression levels of CNPY2 (canopy fibroblast growth factor signaling regulator 2), a known proliferative and angiogenic factor, were increased in pulmonary artery endothelial cells and pulmonary artery smooth muscle cells of Sirt3skm-/- mice and animal models of PH-HFpEF. CNPY2 levels were also higher in pulmonary artery smooth muscle cells of subjects with obesity compared with nonobese subjects. Moreover, treatment with recombinant LOXL2 protein promoted pulmonary artery endothelial cell migration/proliferation and pulmonary artery smooth muscle cell proliferation through regulation of CNPY2-p53 signaling. Last, skeletal muscle-specific Loxl2 deletion decreased pulmonary artery endothelial cell and pulmonary artery smooth muscle cell expression of CNPY2 and improved pulmonary pressures in mice with high-fat diet-induced PH-HFpEF.

CONCLUSIONS

This study demonstrates a systemic pathogenic impact of skeletal muscle SIRT3 deficiency in remote pulmonary vascular remodeling and PH-HFpEF. This study suggests a new endocrine signaling axis that links skeletal muscle health and SIRT3 deficiency to remote CNPY2 regulation in the pulmonary vasculature through myokine LOXL2. Our data also identify skeletal muscle SIRT3, myokine LOXL2, and CNPY2 as potential targets for the treatment of PH-HFpEF.

Essential Roles of PIEZO1 in Mammalian Cardiovascular System: From Development to Diseases

Mechanical force is the basis of cardiovascular development, homeostasis, and diseases. The perception and response of mechanical force by the cardiovascular system are crucial. However, the molecular mechanisms mediating mechanotransduction in the cardiovascular system are not yet understood. PIEZO1, a novel transmembrane mechanosensitive cation channel known for its regulation of touch sensation, has been found to be widely expressed in the mammalian cardiovascular system. In this review, we elucidate the role and mechanism of PIEZO1 as a mechanical sensor in cardiovascular development, homeostasis, and disease processes, including embryo survival, angiogenesis, cardiac development repair, vascular inflammation, lymphangiogenesis, blood pressure regulation, cardiac hypertrophy, cardiac fibrosis, ventricular remodeling, and heart failure. We further summarize chemical molecules targeting PIEZO1 for potential translational applications. Finally, we address the controversies surrounding emergent concepts and challenges in future applications.

Cellular metabolism changes in atherosclerosis and the impact of comorbidities

Cell activation and nutrient dysregulation are common consequences of atherosclerosis and its preceding risk factors, such as hypertension, dyslipidemia, and diabetes. These diseases may also impact cellular metabolism and consequently cell function, and the other way around, altered cellular metabolism can impact disease development and progression through altered cell function. Understanding the contribution of altered cellular metabolism to atherosclerosis and how cellular metabolism may be altered by co-morbidities and atherosclerosis risk factors could support the development of novel strategies to lower the risk of CVD. Therefore, we briefly review disease pathogenesis and the principles of cell metabolic pathways, before detailing changes in cellular metabolism in the context of atherosclerosis and comorbidities. In the hypoxic, inflammatory and hyperlipidemic milieu of the atherosclerotic plaque riddled with oxidative stress, metabolism shifts to increase anaerobic glycolysis, the pentose-phosphate pathway and amino acid use. We elaborate on metabolic changes for macrophages, neutrophils, vascular endothelial cells, vascular smooth muscle cells and lymphocytes in the context of atherosclerosis and its co-morbidities hypertension, dyslipidemia, and diabetes. Since causal relationships of specific key genes in a metabolic pathway can be cell type-specific and comorbidity-dependent, the impact of cell-specific metabolic changes must be thoroughly explored in vivo, with a focus on also systemic effects. When cell-specific treatments become feasible, this information will be crucial for determining the best metabolic intervention to improve atherosclerosis and its interplay with co-morbidities.

A comprehensive map of proteoglycan expression and deposition in the pulmonary arterial wall in health and pulmonary hypertension

Changes in the extracellular matrix of pulmonary arteries (PAs) are a key aspect of vascular remodeling in pulmonary hypertension (PH). Yet, our understanding of the alterations affecting the proteoglycan (PG) family remains limited. We sought to investigate the expression and spatial distribution of major vascular PGs in PAs from healthy individuals and various PH groups (chronic obstructive pulmonary disease: PH-COPD, pulmonary fibrosis: PH-PF, idiopathic: IPAH). PG regulation, deposition, and synthesis were notably heightened in IPAH, followed by PH-PF, with minor alterations in PH-COPD. Single-cell analysis unveiled cell-type and disease-specific PG regulation. Agrin expression, a basement membrane PG, was increased in IPAH, with PA endothelial cells (PAECs) identified as a major source. PA smooth muscle cells (PASMCs) mainly produced large-PGs, aggrecan and versican, and small-leucine-like proteoglycan (SLRP) biglycan, whereas the major PGs produced by adventitial fibroblasts were SLRP decorin and lumican. In IPAH and PF-PH, the neointima-forming PASMC population increased the expression of all investigated large-PGs and SLRPs, except fibroblast-predominant decorin (DCN). Expression of lumican, versican, and biglycan also positively correlated with collagen 1α1/1α2 expression in PASMCs in patients with IPAH and PH-PF. We demonstrated that transforming growth factor-beta (TGF-β) regulates versican and biglycan expression, indicating their contribution to vessel fibrosis in IPAH and PF-PH. We furthermore show that certain circulating PG levels display a disease-dependent pattern, with increased decorin and lumican across all patient groups, while versican was elevated in PH-COPD and IPAH and biglycan reduced in IPAH. These findings suggest unique compartment-specific PG regulation in different forms of PH, indicating distinct pathological processes.NEW & NOTEWORTHY Idiopathic pulmonary arterial hypertension (IPAH) pulmonary arteries (PAs) displayed the greatest proteoglycan (PG) changes, with PH associated with pulmonary fibrosis (PH-PF) and PH associated with chronic obstructive pulmonary disease (PH-COPD) following. Agrin, an endothelial cell-specific PG, was solely upregulated in IPAH. Among all cells, neo-intima-forming smooth muscle cells (SMCs) displayed the most significant PG increase. Increased levels of circulating decorin, lumican, and versican, mainly derived from SMCs, and adventitial fibroblasts, may serve as systemic indicators of pulmonary remodeling, reflecting perivascular fibrosis and neointima formation.

Tape-assisted fabrication method for constructing PDMS membrane-containing culture devices with cyclic radial stretching stimulation

Advanced in vitro culture systems have emerged as alternatives to animal testing and traditional cell culture methods in biomedical research. Polydimethylsiloxane (PDMS) is frequently used in creating sophisticated culture devices owing to its elastomeric properties, which allow mechanical stretching to simulate physiological movements in cell experiments. We introduce a straightforward method that uses three types of commercial tape-generic, magic and masking-to fabricate PDMS membranes with microscale thicknesses (47.2 µm for generic, 58.1 µm for magic and 89.37 µm for masking) in these devices. These membranes are shaped as the bases of culture wells and can perform cyclic radial movements controlled via a vacuum system. In experiments with A549 cells under three mechanical stimulation conditions, we analysed transcriptional regulators responsive to external mechanical stimuli. Results indicated increased nuclear yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) activity in both confluent and densely packed cells under cyclically mechanical strains (Pearson's coefficient (PC) of 0.59 in confluent and 0.24 in dense cells) compared with static (PC = 0.47 in confluent and 0.13 in dense) and stretched conditions (PC = 0.55 in confluent and 0.20 in dense). This technique offers laboratories without microfabrication capabilities a viable option for exploring cellular behaviour under dynamic mechanical stimulation using PDMS membrane-equipped devices.

PDZ-Binding Kinase, a Novel Regulator of Vascular Remodeling in Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is high blood pressure in the lungs that originates from structural changes in small resistance arteries. A defining feature of PAH is the inappropriate remodeling of pulmonary arteries (PA) leading to right ventricle failure and death. Although treatment of PAH has improved, the long-term prognosis for patients remains poor, and more effective targets are needed.

METHODS

Gene expression was analyzed by microarray, RNA sequencing, quantitative polymerase chain reaction, Western blotting, and immunostaining of lung and isolated PA in multiple mouse and rat models of pulmonary hypertension (PH) and human PAH. PH was assessed by digital ultrasound, hemodynamic measurements, and morphometry.

RESULTS

Microarray analysis of the transcriptome of hypertensive rat PA identified a novel candidate, PBK (PDZ-binding kinase), that was upregulated in multiple models and species including humans. PBK is a serine/threonine kinase with important roles in cell proliferation that is minimally expressed in normal tissues but significantly increased in highly proliferative tissues. PBK was robustly upregulated in the medial layer of PA, where it overlaps with markers of smooth muscle cells. Gain-of-function approaches show that active forms of PBK increase PA smooth muscle cell proliferation, whereas silencing PBK, dominant negative PBK, and pharmacological inhibitors of PBK all reduce proliferation. Pharmacological inhibitors of PBK were effective in PH reversal strategies in both mouse and rat models, providing translational significance. In a complementary genetic approach, PBK was knocked out in rats using CRISPR/Cas9 editing, and loss of PBK prevented the development of PH. We found that PBK bound to PRC1 (protein regulator of cytokinesis 1) in PA smooth muscle cells and that multiple genes involved in cytokinesis were upregulated in experimental models of PH and human PAH. Active PBK increased PRC1 phosphorylation and supported cytokinesis in PA smooth muscle cells, whereas silencing or dominant negative PBK reduced cytokinesis and the number of cells in the G2/M phase of the cell cycle.

CONCLUSIONS

PBK is a newly described target for PAH that is upregulated in proliferating PA smooth muscle cells, where it contributes to proliferation through changes in cytokinesis and cell cycle dynamics to promote medial thickening, fibrosis, increased PA resistance, elevated right ventricular systolic pressure, right ventricular remodeling, and PH.

Glutaminolysis is a Potential Therapeutic Target for Kidney Diseases

Metabolic reprogramming contributes to the progression and prognosis of various kidney diseases. Glutamine is the most abundant free amino acid in the body and participates in more metabolic processes than other amino acids. Altered glutamine metabolism is a prominent feature in different kidney diseases. Glutaminolysis converts glutamine into the TCA cycle metabolite, alpha-ketoglutarate, via a cascade of enzymatic reactions. This metabolic pathway plays pivotal roles in inflammation, maladaptive repair, cell survival and proliferation, redox homeostasis, and immune regulation. Given the crucial role of glutaminolysis in bioenergetics and anaplerotic fluxes in kidney pathogenesis, studies on this cascade could provide a better understanding of kidney diseases, thus inspiring the development of potential methods for targeted therapy. Emerging evidence has shown that targeting glutaminolysis is a promising therapeutic strategy for ameliorating kidney disease. In this narrative review, equation including keywords related to glutamine, glutaminolysis and kidney are subjected to an exhaustive search on Pubmed database, we identified all relevant articles published before 1 April, 2024. Afterwards, we summarize the regulation of glutaminolysis in major kidney diseases and its underlying molecular mechanisms. Furthermore, we highlight therapeutic strategies targeting glutaminolysis and their potential clinical applications.

Dietary intake and glutamine-serine metabolism control pathologic vascular stiffness

Perivascular collagen deposition by activated fibroblasts promotes vascular stiffening and drives cardiovascular diseases such as pulmonary hypertension (PH). Whether and how vascular fibroblasts rewire their metabolism to sustain collagen biosynthesis remains unknown. Here, we found that inflammation, hypoxia, and mechanical stress converge on activating the transcriptional coactivators YAP and TAZ (WWTR1) in pulmonary arterial adventitial fibroblasts (PAAFs). Consequently, YAP and TAZ drive glutamine and serine catabolism to sustain proline and glycine anabolism and promote collagen biosynthesis. Pharmacologic or dietary intervention on proline and glycine anabolic demand decreases vascular stiffening and improves cardiovascular function in PH rodent models. By identifying the limiting metabolic pathways for vascular collagen biosynthesis, our findings provide guidance for incorporating metabolic and dietary interventions for treating cardiopulmonary vascular disease.

A review on decoding the roles of YAP/TAZ signaling pathway in cardiovascular diseases: Bridging molecular mechanisms to therapeutic insights

Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) serve as transcriptional co-activators that dynamically shuttle between the cytoplasm and nucleus, resulting in either the suppression or enhancement of their downstream gene expression. Recent emerging evidence demonstrates that YAP/TAZ is strongly implicated in the pathophysiological processes that contribute to cardiovascular diseases (CVDs). In the cardiovascular system, YAP/TAZ is involved in the orchestration of a range of biological processes such as oxidative stress, inflammation, proliferation, and autophagy. Furthermore, YAP/TAZ has been revealed to be closely associated with the initiation and development of various cardiovascular diseases, including atherosclerosis, pulmonary hypertension, myocardial fibrosis, cardiac hypertrophy, and cardiomyopathy. In this review, we delve into recent studies surrounding YAP and TAZ, along with delineating their roles in contributing to the pathogenesis of CVDs with a link to various physiological processes in the cardiovascular system. Additionally, we highlight the current potential drugs targeting YAP/TAZ for CVDs therapy and discuss their challenges for translational application. Overall, this review may offer novel insights for understanding and treating cardiovascular disorders.

Unveiling the metabolic landscape of pulmonary hypertension: insights from metabolomics

Pulmonary hypertension (PH) is regarded as cardiovascular disease with an extremely poor prognosis, primarily due to irreversible vascular remodeling. Despite decades of research progress, the absence of definitive curative therapies remains a critical challenge, leading to high mortality rates. Recent studies have shown that serious metabolic disorders generally exist in PH animal models and patients of PH, which may be the cause or results of the disease. It is imperative for future research to identify critical biomarkers of metabolic dysfunction in PH pathophysiology and to uncover metabolic targets that could enhance diagnostic and therapeutic strategies. Metabolomics offers a powerful tool for the comprehensive qualitative and quantitative analysis of metabolites within specific organisms or cells. On the basis of the findings of the metabolomics research on PH, this review summarizes the latest research progress on metabolic pathways involved in processes such as amino acid metabolism, carbohydrate metabolism, lipid metabolism, and nucleotide metabolism in the context of PH.

Recent advances of mechanosensitive genes in vascular endothelial cells for the formation and treatment of atherosclerosis

Atherosclerotic cardiovascular disease and its complications are a high-incidence disease worldwide. Numerous studies have shown that blood flow shear has a huge impact on the function of vascular endothelial cells, and it plays an important role in gene regulation of pro-inflammatory, pro-thrombotic, pro-oxidative stress, and cell permeability. Many important endothelial cell mechanosensitive genes have been discovered, including KLK10, CCN gene family, NRP2, YAP, TAZ, HIF-1α, NF-κB, FOS, JUN, TFEB, KLF2/KLF4, NRF2, and ID1. Some of them have been intensively studied, whereas the relevant regulatory mechanism of other genes remains unclear. Focusing on these mechanosensitive genes will provide new strategies for therapeutic intervention in atherosclerotic vascular disease. Thus, this article reviews the mechanosensitive genes affecting vascular endothelial cells, including classical pathways and some newly screened genes, and summarizes the latest research progress on their roles in the pathogenesis of atherosclerosis to reveal effective therapeutic targets of drugs and provide new insights for anti-atherosclerosis.

The interplay between hippo signaling and mitochondrial metabolism: Implications for cellular homeostasis and disease

Mitochondria are the membrane-bound organelles producing energy for cellular metabolic processes. They orchestrate diverse cell signaling cascades regulating cellular homeostasis. This functional versatility may be attributed to their ability to regulate mitochondrial dynamics, biogenesis, and apoptosis. The Hippo pathway, a conserved signaling pathway, regulates various cellular processes, including mitochondrial functions. Through its effectors YAP and TAZ, the Hippo pathway regulates transcription factors and creates a seriatim process that mediates cellular metabolism, mitochondrial dynamics, and survival. Mitochondrial dynamics also potentially regulates Hippo signaling activation, indicating a bidirectional relationship between the two. This review outlines the interplay between the Hippo signaling components and the multifaceted role of mitochondria in cellular homeostasis under physiological and pathological conditions.

Extracellular matrix stiffness as an energy metabolism regulator drives osteogenic differentiation in mesenchymal stem cells

The biophysical factors of biomaterials such as their stiffness regulate stem cell differentiation. Energy metabolism has been revealed an essential role in stem cell lineage commitment. However, whether and how extracellular matrix (ECM) stiffness regulates energy metabolism to determine stem cell differentiation is less known. Here, the study reveals that stiff ECM promotes glycolysis, oxidative phosphorylation, and enhances antioxidant defense system during osteogenic differentiation in MSCs. Stiff ECM increases mitochondrial fusion by enhancing mitofusin 1 and 2 expression and inhibiting the dynamin-related protein 1 activity, which contributes to osteogenesis. Yes-associated protein (YAP) impacts glycolysis, glutamine metabolism, mitochondrial dynamics, and mitochondrial biosynthesis to regulate stiffness-mediated osteogenic differentiation. Furthermore, glycolysis in turn regulates YAP activity through the cytoskeletal tension-mediated deformation of nuclei. Overall, our findings suggest that YAP is an important mechanotransducer to integrate ECM mechanical cues and energy metabolic signaling to affect the fate of MSCs. This offers valuable guidance to improve the scaffold design for bone tissue engineering constructs.

Neutrophil extracellular traps promote proliferation of pulmonary smooth muscle cells mediated by CCDC25 in pulmonary arterial hypertension

BACKGROUND

Previous studies have indicated that neutrophil extracellular traps (NETs) play a pivotal role in pathogenesis of pulmonary arterial hypertension (PAH). However, the specific mechanism underlying the impact of NETs on pulmonary artery smooth muscle cells (PASMCs) has not been determined. The objective of this study was to elucidate underlying mechanisms through which NETs contribute to progression of PAH.

METHODS

Bioinformatics analysis was employed in this study to screen for potential molecules and mechanisms associated with occurrence and development of PAH. These findings were subsequently validated in human samples, coiled-coil domain containing 25 (CCDC25) knockdown PASMCs, as well as monocrotaline-induced PAH rat model.

RESULTS

NETs promoted proliferation of PASMCs, thereby facilitating pathogenesis of PAH. This phenomenon was mediated by the activation of transmembrane receptor CCDC25 on PASMCs, which subsequently activated ILK/β-parvin/RAC1 pathway. Consequently, cytoskeletal remodeling and phenotypic transformation occur in PASMCs. Furthermore, the level of NETs could serve as an indicator of PAH severity and as potential therapeutic target for alleviating PAH.

CONCLUSION

This study elucidated the involvement of NETs in pathogenesis of PAH through their influence on the function of PASMCs, thereby highlighting their potential as promising targets for the evaluation and treatment of PAH.

Inactivation of Malic Enzyme 1 in Endothelial Cells Alleviates Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a progressive cardiopulmonary disease with a high mortality rate. Although growing evidence has revealed the importance of dysregulated energetic metabolism in the pathogenesis of PH, the underlying cellular and molecular mechanisms are not fully understood. In this study, we focused on ME1 (malic enzyme 1), a key enzyme linking glycolysis to the tricarboxylic acid cycle. We aimed to determine the role and mechanistic action of ME1 in PH.

METHODS

Global and endothelial-specific ME1 knockout mice were used to investigate the role of ME1 in hypoxia- and SU5416/hypoxia (SuHx)-induced PH. Small hairpin RNA and ME1 enzymatic inhibitor (ME1*) were used to study the mechanism of ME1 in pulmonary artery endothelial cells. Downstream key metabolic pathways and mediators of ME1 were identified by metabolomics analysis in vivo and ME1-mediated energetic alterations were examined by Seahorse metabolic analysis in vitro. The pharmacological effect of ME1* on PH treatment was evaluated in PH animal models induced by SuHx.

RESULTS

We found that ME1 protein level and enzymatic activity were highly elevated in lung tissues of patients and mice with PH, primarily in vascular endothelial cells. Global knockout of ME1 protected mice from developing hypoxia- or SuHx-induced PH. Endothelial-specific ME1 deletion similarly attenuated pulmonary vascular remodeling and PH development in mice, suggesting a critical role of endothelial ME1 in PH. Mechanistic studies revealed that ME1 inhibition promoted downstream adenosine production and activated A2AR-mediated adenosine signaling, which leads to an increase in nitric oxide generation and a decrease in proinflammatory molecule expression in endothelial cells. ME1 inhibition activated adenosine production in an ATP-dependent manner through regulating malate-aspartate NADH (nicotinamide adenine dinucleotide plus hydrogen) shuttle and thereby balancing oxidative phosphorylation and glycolysis. Pharmacological inactivation of ME1 attenuated the progression of PH in both preventive and therapeutic settings by promoting adenosine production in vivo.

CONCLUSIONS

Our findings indicate that ME1 upregulation in endothelial cells plays a causative role in PH development by negatively regulating adenosine production and subsequently dysregulating endothelial functions. Our findings also suggest that ME1 may represent as a novel pharmacological target for upregulating protective adenosine signaling in PH therapy.

GRK2-YAP signaling is implicated in pulmonary arterial hypertension development

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterized by excessive proliferation of small pulmonary arterial vascular smooth muscle cells (PASMCs), endothelial dysfunction, and extracellular matrix remodeling. G protein-coupled receptor kinase 2 (GRK2) plays an important role in the maintenance of vascular tone and blood flow. However, the role of GRK2 in the pathogenesis of PAH is unknown.

METHODS

GRK2 levels were detected in lung tissues from healthy people and PAH patients. C57BL/6 mice, vascular smooth muscle cell-specific Grk2 -knockout mice ( Grk2ΔSM22 ), and littermate controls ( Grk2flox/flox ) were grouped into control and hypoxia mice ( n  = 8). Pulmonary hypertension (PH) was induced by exposure to chronic hypoxia (10%) combined with injection of the SU5416 (cHx/SU). The expression levels of GRK2 and Yes-associated protein (YAP) in pulmonary arteries and PASMCs were detected by Western blotting and immunofluorescence staining. The mRNA expression levels of Grk2 and Yes-associated protein ( YAP ) in PASMCs were quantified with real-time polymerase chain reaction (RT-PCR). Wound-healing assay, 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, and 5-Ethynyl-2'-deoxyuridine (EdU) staining were performed to evaluate the proliferation and migration of PASMCs. Meanwhile, the interaction among proteins was detected by immunoprecipitation assays.

RESULTS

The expression levels of GRK2 were upregulated in the pulmonary arteries of patients with PAH and the lungs of PH mice. Moreover, cHx/SU-induced PH was attenuated in Grk2ΔSM22 mice compared with littermate controls. The amelioration of PH in Grk2ΔSM22 mice was accompanied by reduced pulmonary vascular remodeling. In vitro study further confirmed that GRK2 knock-down significantly altered hypoxia-induced PASMCs proliferation and migration, whereas this effect was severely intensified by overexpression of GRK2 . We also identified that GRK2 promoted YAP expression and nuclear translocation in PASMCs, resulting in excessive PASMCs proliferation and migration. Furthermore, GRK2 is stabilized by inhibiting phosphorylating GRK2 on Tyr86 and subsequently activating ubiquitylation under hypoxic conditions.

CONCLUSION

Our findings suggest that GRK2 plays a critical role in the pathogenesis of PAH, via regulating YAP expression and nuclear translocation. Therefore, GRK2 serves as a novel therapeutic target for PAH treatment.

TSPAN8+ myofibroblastic cancer-associated fibroblasts promote chemoresistance in patients with breast cancer

Cancer-associated fibroblasts (CAFs) are abundant stromal cells in the tumor microenvironment that promote cancer progression and relapse. However, the heterogeneity and regulatory roles of CAFs underlying chemoresistance remain largely unclear. Here, we performed a single-cell analysis using high-dimensional flow cytometry analysis and identified a distinct senescence-like tetraspanin-8 (TSPAN8)+ myofibroblastic CAF (myCAF) subset, which is correlated with therapeutic resistance and poor survival in multiple cohorts of patients with breast cancer (BC). TSPAN8+ myCAFs potentiate the stemness of the surrounding BC cells through secretion of senescence-associated secretory phenotype (SASP)-related factors IL-6 and IL-8 to counteract chemotherapy. NAD-dependent protein deacetylase sirtuin 6 (SIRT6) reduction was responsible for the senescence-like phenotype and tumor-promoting role of TSPAN8+ myCAFs. Mechanistically, TSPAN8 promoted the phosphorylation of ubiquitin E3 ligase retinoblastoma binding protein 6 (RBBP6) at Ser772 by recruiting MAPK11, thereby inducing SIRT6 protein destruction. In turn, SIRT6 down-regulation up-regulated GLS1 and PYCR1, which caused TSPAN8+ myCAFs to secrete aspartate and proline, and therefore proved a nutritional niche to support BC outgrowth. By demonstrating that TSPAN8+SIRT6low myCAFs were tightly associated with unfavorable disease outcomes, we proposed that the combined regimen of anti-TSPAN8 antibody and SIRT6 activator MDL-800 is a promising approach to overcome chemoresistance. These findings highlight that senescence contributes to CAF heterogeneity and chemoresistance and suggest that targeting TSPAN8+ myCAFs is a promising approach to circumvent chemoresistance.