Platelet-derived microvesicles induce calcium oscillations and promote VSMC migration via TRPV4

TRPV4 Promotes Vascular Calcification by Directly Associating With and Activating β-Catenin

BACKGROUND

Vascular calcification contributes to increased cardiovascular morbidity and mortality in patients with chronic kidney disease, diabetes, and atherosclerosis. Currently, there are no effective therapeutic strategies to prevent or reverse vascular calcification. TRPV4 (transient receptor potential channel V4), a key Ca2+-permeable channel, plays an important role in various diseases. However, the role and mechanism of TRPV4 in vascular calcification have not yet been elucidated.

METHODS

The effects of TRPV4 on vascular calcification were explored in vitro and in vivo. TRPV4 interactome assessment and molecular docking were performed to investigate the mechanism and specific therapeutic strategy for vascular calcification.

RESULTS

TRPV4 was substantially upregulated in high inorganic phosphate-induced calcified vascular smooth muscle cells (SMCs) and calcified aortas from cholecalciferol (vitamin D3)-overloaded mice. TRPV4 overexpression increased the expression of the osteochondrogenic markers Runx2 (runt-related transcription factor 2), Msx2 (Msh homeobox 2), and Sox9 (SRY-box transcription factor 9) and exacerbated high inorganic phosphate-induced vascular SMC calcification in a Ca2+ influx-dependent manner. In contrast, TRPV4 deficiency or inactivation significantly inhibited vascular SMC calcification under high inorganic phosphate conditions. Moreover, compared with that in control littermates, SMC-specific TRPV4 deficiency in mice alleviated vitamin D3-induced and 5/6 nephrectomy-induced vascular calcification. Mechanistically, TRPV4 interacted with β-catenin and activated β-catenin/TCF (T-cell factor) transcriptional activity via Ca2+/ASK1 (apoptosis signal regulating kinase 1)/p38 signaling. β-Catenin knockdown abolished the effects of TRPV4 overexpression on vascular SMC calcification. TRPV4/β-catenin interaction is pivotal for maintaining TRPV4/Ca2+-induced ASK1/p38/β-catenin activation. Hesperidin, a natural product found in citrus fruits, effectively disrupted TRPV4/β-catenin interaction, thereby inhibiting ASK1/p38/β-catenin activity and preventing vascular calcification.

CONCLUSIONS

Our study identified TRPV4 as a new pathogenic factor for vascular calcification that directly associates with and activates β-catenin. Blocking the TRPV4/β-catenin interaction through hesperidin suppressed the progression of vascular calcification and may be an effective precision strategy to address vascular calcification.

Phenotypic switch of vascular smooth muscle cells in COVID-19: Role of cholesterol, calcium, and phosphate

Although the novel coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily manifests as severe respiratory distress, its impact on the cardiovascular system is also notable. Studies reveal that COVID-19 patients often suffer from certain vascular diseases, partly attributed to increased proliferation or altered phenotype of vascular smooth muscle cells (VSMCs). Although the association between COVID-19 and VSMCs is recognized, the precise mechanism underlying SARS-CoV-2's influence on VSMC phenotype remains largely under-reviewed. In this context, while there is a consistent body of literature dissecting the effect of COVID-19 on the cardiovascular system, few reports delve into the potential role of VSMC switching in the pathophysiology associated with COVID-19 and the molecular mechanisms involved therein. This review dissects and critiques the link between COVID-19 and VSMCs, with particular attention to pathways involving cholesterol, calcium, and phosphate. These pathways underpin the interaction between the virus and VSMCs. Such interaction promotes VSMC proliferation, and eventually potentiates vascular calcification as well as worsens prognosis in patients with COVID-19.

Plasma Phenylacetylglutamine Levels and Prognosis of Ischemic Stroke: A Multicenter Prospective Study Based on the CATIS Trial

BACKGROUND

Phenylacetylglutamine is implicated in platelet clotting and thrombosis, but its prognostic value in ischemic stroke remains unclear. We aimed to explore the associations of plasma phenylacetylglutamine levels with adverse outcomes after ischemic stroke in a multicenter prognostic cohort study.

METHODS

Our multicenter prognostic cohort study included 3564 Chinese patients with ischemic stroke from the CATIS (China Antihypertensive Trial in Acute Ischemic Stroke). All patients were followed up at 3 months after ischemic stroke onset. The primary outcome was the composite outcome of death or major disability (modified Rankin Scale score, 3-6) at 3 months after ischemic stroke.

RESULTS

During 3 months of follow-up, 877 participants experienced the primary outcome. After multivariate adjustment, each 500 ng/mL increase of phenylacetylglutamine was associated with a 7% (P=0.012), 6% (P=0.016), and 6% (P=0.028) increased risk of the primary outcome, major disability, and death, respectively. The odds ratios or hazard ratios in the highest versus the lowest quartile of plasma phenylacetylglutamine were 1.62 ([95% CI, 1.18-2.23]; Ptrend=0.001) for the primary outcome, 1.62 ([95% CI, 1.16-2.24]; Ptrend=0.001) for major disability, and 2.59 ([95% CI, 1.19-5.60]; Ptrend=0.025) for death, respectively. There was a significantly worse shift in the distribution of modified Rankin Scale score at 3 months with higher phenylacetylglutamine quartiles (Ptrend=0.003). Multiple-adjusted spline regression model showed a linear relationship between phenylacetylglutamine and primary outcome (P value for linearity<0.001). The addition of plasma phenylacetylglutamine to conventional risk factors significantly improved the risk reclassification for the primary outcome (net reclassification improvement, 19.34%; P<0.001; integrated discrimination improvement, 0.23%; P=0.019).

CONCLUSIONS

Elevated plasma phenylacetylglutamine levels at baseline were associated with increased risks of adverse clinical outcomes at 3 months after ischemic stroke, suggesting that phenylacetylglutamine may be a promising prognostic biomarker for ischemic stroke. Further studies are needed to investigate whether phenylacetylglutamine is a stroke-specific biomarker.

Altered dynamics of calcium fluxes and mitochondrial metabolism in platelet activation-related disease and aging

Understanding the mechanisms controlling platelet function is crucial for exploring potential therapeutic targets related to atherothrombotic pathologies and primary hemostasis disorders. Our research, which focuses on the role of platelet mitochondria and Ca2+ fluxes in platelet activation, the formation of the procoagulant phenotype, and thrombosis, has significant implications for the development of new therapeutic strategies. Traditionally, Ca2+-dependent cellular signaling has been recognized as a determinant process throughout the platelet activation, controlled primarily by store-operated Ca2+ entry and the PLC-PKC signaling pathway. However, despite the accumulated knowledge of these regulatory mechanisms, the effectiveness of therapy based on various commonly used antiplatelet drugs (such as acetylsalicylic acid and clopidogrel, among others) has faced challenges due to bleeding risks and reduced efficacy associated with the phenomenon of high platelet reactivity. Recent evidence suggests that platelet mitochondria could play a fundamental role in these aspects through Ca2+-dependent mechanisms linked to apoptosis and forming a procoagulant phenotype. In this context, the present review describes the latest advances regarding the role of platelet mitochondria and Ca2+ fluxes in platelet activation, the formation of the procoagulant phenotype, and thrombosis.

The Multifaceted Functions of TRPV4 and Calcium Oscillations in Tissue Repair

The transient receptor potential vanilloid 4 (TRPV4) specifically functions as a mechanosensitive ion channel and is responsible for conveying changes in physical stimuli such as mechanical stress, osmotic pressure, and temperature. TRPV4 enables the entry of cation ions, particularly calcium ions, into the cell. Activation of TRPV4 channels initiates calcium oscillations, which trigger intracellular signaling pathways involved in a plethora of cellular processes, including tissue repair. Widely expressed throughout the body, TRPV4 can be activated by a wide array of physicochemical stimuli, thus contributing to sensory and physiological functions in multiple organs. This review focuses on how TRPV4 senses environmental cues and thereby initiates and maintains calcium oscillations, critical for responses to organ injury, tissue repair, and fibrosis. We provide a summary of TRPV4-induced calcium oscillations in distinct organ systems, along with the upstream and downstream signaling pathways involved. In addition, we delineate current animal and disease models supporting TRPV4 research and shed light on potential therapeutic targets for modulating TRPV4-induced calcium oscillation to promote tissue repair while reducing tissue fibrosis.

Resolvin E1/ChemR23 Protects Against Hypertension and Vascular Remodeling in Angiotensin II-Induced Hypertensive Mice

BACKGROUND

Inflammation plays a critical role in the development of hypertension and vascular remodeling. Resolvin E1 (RvE1), as one of the specialized proresolving lipid mediators, promotes inflammation resolution by binding with a G protein-coupled receptor, ChemR23 (chemerin receptor 23). However, whether RvE1/ChemR23 regulates hypertension and vascular remodeling is unknown.

METHODS

Hypertension in mice was induced by Ang II (angiotensin II) infusion (750 ng/kg per minute), and RvE1 (2 µg/kg per day) was administered through intraperitoneal injection. Loss of ChemR23 was achieved by mice receiving intravenous injection of adeno-associated virus 9-encoding shRNA against ChemR23.

RESULTS

Aortic ChemR23 expression was increased in Ang II-induced hypertensive mice and that ChemR23 was mainly expressed on vascular smooth muscle cells (VSMCs). RvE1 lowered blood pressure, reduced aortic media thickness, attenuated aortic fibrosis, and mitigated VSMC phenotypic transformation and proliferation in hypertensive mice, which were all reversed by the knockdown of ChemR23. Moreover, RvE1 reduced the aortic infiltration of macrophages and T cells, which was also reversed by ChemR23 knockdown. RvE1 inhibited Ccl5 expression in VSMCs via the AMPKα (AMP-activated protein kinase α)/Nrf2 (nuclear factor E2-related factor 2)/canonical NF-κB (nuclear factor κB) pathway, thereby reducing the infiltration of macrophages and T cells. The AMPKα/Nrf2 pathway also mediated the effects of RvE1 on VSMC phenotypic transformation and proliferation. In patients with hypertension, the serum levels of RvE1 and other eicosapentaenoic acid-derived metabolites were significantly decreased.

CONCLUSIONS

RvE1/ChemR23 ameliorated hypertension and vascular remodeling by activating AMPKα/Nrf2 signaling, which mediated immune cell infiltration by inhibiting the canonical NF-κB/Ccl5 pathway, and regulated VSMC proliferation and phenotypic transformation. RvE1/ChemR23 may be a potential therapeutic target for hypertension.

Platelet-derived microvesicles induce intracellular calcium mobilization in human platelets

Platelet-derived microvesicles (PMVs) represent a significant proportion of microvesicles in circulation and have been linked to various pathophysiological complications. Recent research suggests that PMVs carry significant amounts of cargo that can affect cellular functions by influencing calcium oscillations in target cells. As calcium is involved in multiple cellular processes, including hemostasis and thrombosis, this study aimed to investigate the impact of PMVs on platelet calcium mobilization. The study found that PMVs increase platelet intracellular calcium levels via both intracellular storage and extracellular space in a dose-dependent manner. The study highlighted the critical role of the dense tubular system, acidic vacuoles, mitochondrial stores, and store-operated calcium entry (SOCE) in PMV-mediated calcium release in human platelets. Moreover, the study revealed that PMV-induced calcium rise in platelets does not occur via sarcoendoplasmic reticulum calcium ATPase, and extracellular calcium addition further increases the calcium level in platelets, demonstrating the involvement of SOCE. These findings provide insights into the platelet stimulation signaling mechanisms and contributes to our understanding of platelet and cell behavior when exposed to PMV-rich environments.

Mechanosensing and Mechanosignal Transduction in Atherosclerosis

PURPOSE OF REVIEW

This review aims to summarize the latest findings on mechanosensing in atherosclerosis, elucidating the molecular mechanisms, cellular players, and potential therapeutic targets.

RECENT FINDINGS

Atherosclerosis, a chronic inflammatory disease characterized by the buildup of lipid-laden plaque within arterial walls, is a major contributor to cardiovascular disease-related mortality and morbidity. Interestingly, atherosclerosis predominantly occurs in arterial areas with curves and branches. In these regions, endothelial cells encounter irregular blood flow with distinctive low-intensity fluctuating shear stress. On the other hand, straight sections of arteries, subjected to a consistent flow and related high-intensity, one-way shear stress, are relatively safeguarded against atherosclerosis due to shear-dependent, disease-preventing endothelial cell reactions. In recent years, researchers have been investigating the role of mechanosensing in the development and progression of atherosclerosis. At the core of mechanosensing is the ability of various cells to sense and respond to biomechanical forces in their environment. In the context of atherosclerosis, endothelial cells, smooth muscle cells, and immune cells are subjected to various mechanical or physical stimuli, including shear stress, cyclic strain, and matrix stiffness. These mechanical cues play a crucial role in regulating cellular behavior and contribute to the pathophysiology of atherosclerosis. Accumulating evidence suggests that various mechanical or physical cues play a critical role in the development and promotion of atherosclerosis.

MPs-ACT, an Assay to Evaluate the Procoagulant Activity of Microparticles

The procoagulant effect of microparticles (MPs) contributes to hypercoagulability-induced thrombosis. We provide preliminary findings of the MPs-Activated Clotting Time (MPs-ACT) assay to determine the procoagulant activity of MPs. MPs-rich plasma was obtained and recalcified. Changes in plasma viscoelasticity were evaluated and the time to the peak viscoelastic changes was defined as the MPs-ACT. MPs concentration was measured by flow cytometry. Coagulation products produced during plasma clotting were identified by fibrin and fibrinopeptide A. MPs were prepared in vitro and added to standard plasma to simulate pathological samples. In addition, reproducibility and sensitivity were evaluated. We confirmed the linear relationship between MPs-ACT and MP concentrations. Dynamic changes in fibrin production were depicted. We simulated the correlation between MPs-ACT and standard plasma containing MPs prepared in vitro. The reproducibility of high-value and low-value samples was 6.0% and 10.8%, respectively. MPs-ACT sensitively detected hypercoagulable samples from patients with pre-eclampsia, hip fractures, and lung tumors. MPs-ACT largely reflects the procoagulant effect of MPs. MPs-ACT sensitively and rapidly detects hypercoagulability with MPs-rich plasma. It may be promising for the diagnosis of hypercoagulable states induced by MPs.

Mechanism of Hypoxia-Mediated Smooth Muscle Cell Proliferation Leading to Vascular Remodeling

Vascular remodeling refers to changes in the size, contraction, distribution, and flow rate of blood vessels and even changes in vascular function. Vascular remodeling can cause cardiovascular and cerebrovascular diseases. It can also lead to other systemic diseases, such as pulmonary hypertension, pulmonary atherosclerosis, chronic obstructive pulmonary disease, stroke, and ascites of broilers. Hypoxia is one of the main causes of vascular remodeling. Prolonged hypoxia or intermittent hypoxia can lead to loss of lung ventilation, causing respiratory depression, irregular respiratory rhythms, and central respiratory failure. Animals that are unable to adapt to the highland environment are also prone to sustained constriction of the small pulmonary arteries, increased resistance to pulmonary circulation, and impaired blood circulation, leading to pulmonary hypertension and right heart failure if they live in a highland environment for long periods of time. However, limited studies have been found on the relationship between hypoxia and vascular remodeling. Therefore, this review will explore the relationship between hypoxia and vascular remodeling from the aspects of endoplasmic reticulum stress, mitochondrial dysfunction, abnormal calcium channel, disordered cellular metabolism, abnormal expression of miRNA, and other factors. This will help to understand the detailed mechanism of hypoxia-mediated smooth muscle cell proliferation and vascular remodeling for the better treatment and management of diseases due to vascular remodeling.

Sex Differences in Arteriovenous Fistula Failure: Insights from Bioinformatics Analysis

(1) Background: Arteriovenous fistulas (AVFs) are the preferred access for hemodialysis. Unfortunately, about 60% of patients, especially female patients, fail to receive normal dialysis within one year after surgery because of AVF failure. However, the underlying mechanisms caused by sex differences in AVF failure remain unclear. (2) Methods: We performed analysis of DEGs and functional analysis with the dataset GSE119296 to reveal the biology underlying AVF failure. Immune responses were calculated using CIBERSORT. A protein-protein interaction network and hub gene were constructed using STRING and stepwise identification of potential drugs was performed online. (3) Results: Functional analysis showed that extracellular matrix reprogramming and PI3K-AKT pathway enrichment were significant in both male and female patients. COL1A1 was the hub gene in male patients, whereas CDK1 was the hub gene in female patients. Immune responses including γδ-T cells and mast cells are activated in female patients while no significant differences were noted in the male group. (4) Conclusions: In this study, we used a series of mature and recognized bioinformatic strategies to determine the following items: (1) Reveal the pathogenesis of AVF failure through HUB genes and signaling pathways between the different sexes. (2) Determine the relationship between sex differences in AVF failure and immune abnormalities. (3) Search for relevant sex-specific drugs targeting AVF failure.

Prognostic value of plasma phenylalanine and gut microbiota-derived metabolite phenylacetylglutamine in coronary in-stent restenosis

Objective

This study was designed to explore the predictive value of plasma phenylalanine (Phe) and gut microbiota-derived metabolite phenylacetylglutamine (PAGln) in coronary in-stent restenosis (ISR).

Methods

Patients with coronary ISR, in-stent hyperplasia (ISH), and in-stent patency (ISP) were retrospectively enrolled in this study. Multivariable logistic regression analyses were used to identify independent risk factors of ISR. The predictive value of plasma Phe and PAGln levels was evaluated by receiver operating characteristic (ROC) curve analysis. The areas under the ROC curve (AUCs) were compared using the Z-test. The correlation between PAGln and clinical characteristics were examined using Spearman's correlation analysis.

Results

Seventy-two patients (mean age, 64.74 ± 9.47 years) were divided into three groups according to coronary stent patency: ISR (n = 28), ISH (n = 11), and ISP (n = 33) groups. The plasma levels of Phe and PAGln were significantly higher in the ISR group than in the ISP group. PAGln was positively associated with the erythrocyte sedimentation rate, homocysteine, SYNTAX score, triglyceride to high-density lipoprotein ratio, Phe, and microbiota-related intermediate metabolite phenylacetic acid (PA). In the ISR group, with the aggravation of restenosis, PAGln levels were also elevated. In multivariate regression analyses, Phe, PAGln and SYNTAX score were independent predictors of coronary ISR (all P < 0.05). In the ROC curve analyses, both Phe [AUC = 0.732; 95% confidence interval (CI), 0.606–0.858; P = 0.002] and PAGln (AUC = 0.861; 95% CI, 0.766–0.957; P < 0.001) had good discrimination performance in predicting coronary ISR, and the predictive power of PAGln was significantly better (P = 0.031).

Conclusion

Plasma Phe and PAGln are valuable indices for predicting coronary ISR, and gut microbes may be a promising intervention target to prevent ISR progression.

Extracellular Vesicles as Drivers of Immunoinflammation in Atherothrombosis

Atherosclerotic cardiovascular disease is the leading cause of morbidity and mortality all over the world. Extracellular vesicles (EVs), small lipid-bilayer membrane vesicles released by most cellular types, exert pivotal and multifaceted roles in physiology and disease. Emerging evidence emphasizes the importance of EVs in intercellular communication processes with key effects on cell survival, endothelial homeostasis, inflammation, neoangiogenesis, and thrombosis. This review focuses on EVs as effective signaling molecules able to both derail vascular homeostasis and induce vascular dysfunction, inflammation, plaque progression, and thrombus formation as well as drive anti-inflammation, vascular repair, and atheroprotection. We provide a comprehensive and updated summary of the role of EVs in the development or regression of atherosclerotic lesions, highlighting the link between thrombosis and inflammation. Importantly, we also critically describe their potential clinical use as disease biomarkers or therapeutic agents in atherothrombosis.

Study on Extraction and Antioxidant Activity of Flavonoids from Hemerocallis fulva (Daylily) Leaves

Hemerocallis fulva is a medical and edible plant. In this study, we optimized the ultrasound-assisted extraction (UAE) process of extracting flavonoids from Hemerocallis fulva leaves by single-factor experiments and response surface methodology (RSM). The optimum extraction conditions generating the maximal total flavonoids content was as follows: 70.6% ethanol concentration; 43.9:1 mL/g solvent to sample ratio; 61.7 °C extraction temperature. Under the optimized extraction conditions, the total flavonoid content (TFC) in eight Hemerocallis fulva varieties were determined, and H. fulva (L.) L. var. kwanso Regel had the highest TFC. The cytotoxicity of the extract was studied using the Cell Counting Kit-8 (CCK-8 assay). When the concentration was less than 1.25 mg/mL, the extract had no significant cytotoxicity to HaCaT cells. The antioxidant activity was measured via chemical antioxidant activity methods in vitro and via cellular antioxidant activity methods. The results indicated that the extract had a strong ABTS and •OH radical scavenging activity. Additionally, the extract had an excellent protective effect against H2O2-induced oxidative damage at a concentration of 1.25 mg/mL, which could effectively reduce the level of ROS to 106.681 ± 9.733% (p < 0.001), compared with the 163.995 ± 6.308% of the H2O2 group. We identified five flavonoids in the extracts using high-performance liquid chromatography (HPLC). Infrared spectroscopy indicated that the extract contained the structure of flavonoids. The results showed that the extract of Hemerocallis fulva leaves had excellent biocompatibility and antioxidant activity, and could be used as a cheap and potential source of antioxidants in the food, cosmetics, and medicine industries.

Role of Transient Receptor Potential Vanilloid 4 in Vascular Function

Transient receptor potential vanilloid 4 (TRPV4) channels are widely expressed in systemic tissues and can be activated by many stimuli. TRPV4, a Ca²⁺-permeable cation channel, plays an important role in the vasculature and is implicated in the regulation of cardiovascular homeostasis processes such as blood pressure, vascular remodeling, and pulmonary hypertension and edema. Within the vasculature, TRPV4 channels are expressed in smooth muscle cells, endothelial cells, and perivascular nerves. The activation of endothelial TRPV4 contributes to vasodilation involving nitric oxide, prostacyclin, and endothelial-derived hyperpolarizing factor pathways. TRPV4 activation also can directly cause vascular smooth muscle cell hyperpolarization and vasodilation. In addition, TRPV4 activation can evoke constriction in some specific vascular beds or under some pathological conditions. TRPV4 participates in the control of vascular permeability and vascular damage, particularly in the lung capillary endothelial barrier and lung injury. It also participates in vascular remodeling regulation mainly by controlling vasculogenesis and arteriogenesis. This review examines the role of TRPV4 in vascular function, particularly in vascular dilation and constriction, vascular permeability, vascular remodeling, and vascular damage, along with possible mechanisms, and discusses the possibility of targeting TRPV4 for therapy.