Artery Endothelial Cells Research Articles

Berberine ameliorates coronary artery endothelial cell injury in Kawasaki disease through complement and coagulation cascades

To explore the role of berberine (BBR) in ameliorating coronary endothelial cell injury in Kawasaki disease (KD) by regulating the complement and coagulation cascade. Human coronary artery endothelial cells (HCAEC) were divided into a healthy control group, a KD group, and a BBR treatment group (n=3 for each group). The healthy control group and KD group were supplemented with 15% serum from healthy children and KD patients, respectively, while the BBR treatment group received 15% serum from KD patients followed by the addition of 20 mmol/L BBR. Differential protein expression was analyzed and identified using isobaric tags for relative and absolute quantitation technology and liquid chromatography-tandem mass spectrometry, followed by GO functional enrichment analysis and KEGG signaling pathway enrichment analysis of the differential proteins. Western blot was used to detect differential protein expression. A total of 518 differential proteins were identified between the KD group and the healthy control group (300 upregulated proteins and 218 downregulated proteins). A total of 422 differential proteins were identified between the BBR treatment group and the KD group (221 upregulated proteins and 201 downregulated proteins). Bioinformatics analysis showed that compared to the healthy control group, the differential proteins in the KD group were enriched in the complement and coagulation cascade and ribosome biogenesis in eukaryotes. Compared to the KD group, the differential proteins in the BBR treatment group were also enriched in the complement and coagulation cascade and ribosome biogenesis in eukaryotes. Western blot results indicated that compared to the healthy control group, the expression of complement C1q subcomponent subunit C (C1QC), kininogen-1 (KNG1), complement C1s subcomponent (C1S), and C4b-binding protein alpha chain (C4BPA) was increased in the KD group (P<0.05). Compared to the KD group, the expression of KNG1, C1S, C1QC, and C4BPA was decreased in the BBR treatment group (P<0.05). The complement and coagulation cascade may be involved in the regulation of BBR treatment for coronary injury in KD, and C1QC, KNG1, C1S, and C4BPA may serve as biomarkers for this treatment.

Differential substrate specificity of ERK, JNK, and p38 MAP kinases toward Connexin 43.

Phosphorylation of connexin 43 (Cx43) is an important regulatory mechanism of gap junction (GJ) function. Cx43 is modified by several kinases on over 15 sites within its ∼140 amino acid-long C-terminus (CT). Phosphorylation of Cx43CT on S255, S262, S279, and S282 by ERK has been widely documented in several cell lines, by many investigators. Phosphorylation of these sites by JNK and p38, on the other hand, is not well-established. Indeed, ERK is a kinase activated by growth factors and is upregulated in diseases, such as cancer. JNK and p38, however, have a largely tumor-suppressive function due to their stress-activated and apoptotic role. We investigated substrate specificity of all three MAPKs toward Cx43CT, first by using purified proteins, and then in two cell lines (MDCK - non-cancerous, epithelial cells and porcine PAECs - pulmonary artery endothelial cells). Cx43 phosphorylation was monitored through gel-shift assays on an SDS-PAGE, immunodetection with phospho-Cx43 antibodies, and LC-MS/MS phosphoproteomic analyses. Our results demonstrate that p38 and JNK specificity differ from each other and from ERK. JNK has a strong preference for S255, S262, and S279, while p38 readily phosphorylates S262, S279, and S282. While we confirmed that ERK can phosphorylate all four serines (255, 262, 279, and 282), we also identified T290 as a novel ERK phosphorylation site. In addition, we assessed Cx43 GJ function upon activation or inhibition of each MAPK in PAECs. This work underscores the importance of delineating the effects of ERK, JNK, and p38 signaling on Cx43 and GJ function.

NSD2 mediated H3K36me2 promotes pulmonary arterial hypertension by recruiting FOLR1 and metabolism reprogramming.

Pulmonary artery hypertension (PAH) is characterized by a cancer-like metabolic shift towards aerobic glycolysis. Nuclear Receptor Binding SET Domain Protein 2 (NSD2), a histone methyltransferase, has been implicated in PAH, yet its precise role remains unclear. In this study, we induced PAH in C57BL/6 mice using monocrotaline (MCT) and observed increased FOLR1 expression in PAH tissues, which was suppressed by NSD2 knockdown. Silencing NSD2 or FOLR1 inhibited the proliferation and migration of pulmonary artery endothelial cells (PAECs) and alleviated PAH phenotypes, right ventricular dysfunction, and pulmonary artery remodeling. Mechanistically, NSD2 knockdown prevented nuclear translocation of FOLR1 and its interaction with H3K36me2. Metabolic analysis revealed that NSD2 or FOLR1 knockdown reversed the increased oxygen consumption rate, extracellular acidification rate, glucose consumption, lactate production, and G6PD activity in MCT-treated PAECs. Furthermore, NSD2 or FOLR1 silencing decreased the expression of key glycolytic genes (HK2, TIGAR, and G6PD) by suppressing their promoter activity and weakening the interaction between FOLR1/H3K36me2 and these gene promoters. Our findings suggest that NSD2-mediated H3K36me2 recruits FOLR1 to promote PAH, and FOLR1 acts as a transcriptional factor to upregulate glycolytic gene expression in PAECs.

Endothelial cell (EC)-specific CTGF/CCN2 Expression Increases EC Reprogramming and Atherosclerosis.

Arterial endothelial cells (ECs) reside in a complex biomechanical environment. ECs sense and respond to wall shear stress. Low and oscillatory wall shear stress is characteristic of disturbed flow and commonly found at arterial bifurcations and around atherosclerotic plaques. Disturbed flow is pro-inflammatory to ECs. Arteries also stiffen with aging and/or the onset of vascular disease. ECs sense and respond to stiffening in a pro-fibrotic manner. Thus, flow and stiffening disturbances elicit EC responses that promote pathologic arterial remodeling. However, the pathways elicited by ECs under pathologic stiffening and disturbed flow are not well understood. The objective of this work was to discover and test the modifiability of key pathways in ECs. To do this we used the partial carotid ligation model to impose disturbed flow onto the precociously stiffened fibulin-5 knockout (Fbln5-/-) mouse carotid arteries. Biomechanical testing demonstrated that Fbln5-/- arteries under disturbed flow approximate the stiffness ratio of diseased human arteries, and the ECs in these Fbln5-/- arteries underwent rapid reprogramming via endothelial to mesenchymal transition (EndMT). Under atherogenic conditions, disturbed flow Fbln5-/- arteries developed more vulnerable plaques than the wild type (WT) mouse arteries. Connective tissue growth factor/cellular communication network factor 2 (Ctgf/Ccn2) was upregulated in vivo in ECs with aging, with stiffening in the Fbln5-/- arteries, and increased again by disturbed flow under stiffened conditions, supporting CTGF as a key biomarker for flow and stiffening. This was validated by immunohistochemistry, which demonstrated increased CTGF deposition in areas of disturbed flow in patient carotid endarterectomy and peripheral artery disease (PAD) specimens. Finally, to test the role of CTGF in regulating and combining these processes, we created an EC-specific Ctgf knockout (Ctgfecko). We identified that carotid arteries under disturbed flow and atherogenic conditions in male Ctgfecko, but not female, mice had decreased plaque area compared to WT control mice. We then tested the Ctgf expression in the carotid endothelium exposed to disturbed or stable flow in WT and Fbln5-/- mice. Here we found that under disturbed flow male mice had greater Ctgf expression than female mice. This work demonstrates that stiffened + disturbed flow conditions drive EC reprogramming, that CTGF is increased by these conditions, and that this increase is more prominent in male carotid arteries. Future exploration of sex-based differences in these fibrotic pathways are warranted to develop targeted therapeutics to limit pathologic arterial remodeling under pathologically stiffened + disturbed flow environments.

The Role of Intravenous Selexipag in Managing PAH and Bridging Gaps in Oral Treatment: A Narrative Review.

Pulmonary arterial hypertension (PAH) is a rare and potentially fatal condition characterized by progressive increases in blood pressure in the arteries of the lungs. Oral selexipag, approved by the Food and Drug Administration (FDA) in 2015 for the treatment of PAH, targets prostacyclin receptors on pulmonary arterial vascular smooth muscle and endothelial cells to improve blood flow through the lungs and reduce pulmonary vascular resistance. Oral selexipag is effective, but may be discontinued due to factors like side effects, emergency conditions, or inability to take oral medication, potentially leading to severe adverse events, such as rebound pulmonary hypertension and right heart failure. To address treatment interruptions, intravenous (IV) selexipag was introduced as an alternative for patients who are temporarily unable to take oral medications. IV selexipag bypasses hepatic metabolism, requiring a 12.5% higher dose compared to the oral form to achieve similar therapeutic effects. It is administered via IV infusion twice daily over 80minutes, typically for short-term use. However, caution is needed when prescribing selexipag to patients with hepatic or renal issues, and it is contraindicated with strong CYP2C8 inhibitors. A Phase III clinical trial confirmed that switching between oral and IV selexipag was safe, with comparable efficacy and tolerability, though it was limited by small sample size and short duration. Given the risks of treatment interruption and the complexity of managing PAH, this review provides essential insights into the practical use of IV selexipag as a bridging therapy. Furthermore, it calls for larger clinical trials to refine dosing strategies, explore long-term outcomes, and identify patient populations most likely to benefit from IV selexipag.

Paracetamol metabolism by endothelial cells - Potential mechanism underlying intravenous paracetamol-induced hypotension.

It was shown previously that a metabolite of acetaminophen (APAP), N-acetyl-p-benzoquinone imine (NAPQI), is a potent vasodilator, which could underlie the hypotension observed when APAP is administered intravenously. However, it is unknown whether APAP metabolism to NAPQI is possible in the vasculature. In this study, we examine the hypothesis that APAP is metabolized by cytochrome P450 enzymes within the endothelium, which may be accelerated in critically ill patients by the presence of elevated myeloperoxidase (MPO). Exposure of human coronary artery endothelial cells (HCAECs) to APAP resulted in the formation of protein-bound APAP adducts. Proteomic analysis of HCAECs exposed to APAP showed upregulation of CYP20A1, together with proteins involved in the pentose phosphate pathway and maintaining redox homeostasis. Proteomic analyses of mesenteric arteries from rats administered intravenous APAP are consistent with a key role of the vascular wall in APAP metabolism, with similar proteomic pathway changes identified in HCAECs. These changes occurred over a short timeframe and were not seen in the corresponding proteomic analyses of liver tissue. Intracellular thiols were depleted in HCAECs upon APAP treatment, which was partially attenuated by ketoconazole, consistent with the involvement of cytochrome P450 enzymes in the metabolism of APAP to a thiol-reactive metabolite such as NAPQI. Evidence was also obtained for the metabolism of APAP to a thiol-reactive intermediate by MPO in the absence of chloride ions, consistent with NAPQI formation. Taken together, these data provide a putative mechanism to explain the presentation of hypotension in critically ill patients following IV APAP administration.

Hypoxia Combined With Interleukin-17 Regulates Hypoxia-Inducible Factor-1α/Endothelial Nitric Oxide Synthase Expression in Pulmonary Artery Endothelial Cells.

The pathogenesis of chronic thromboembolic pulmonary hypertension may be multifactorial and requires further studies. We explored alterations in pulmonary artery endothelial cells under the hypoxic and elevated interleukin-17 conditions that are commonly present in patients with chronic thromboembolic pulmonary hypertension. We measured the serum interleukin-17 levels in 10 chronic thromboembolic pulmonary hypertension patients and 10 healthy control persons. The expressions and localisations of hypoxia-inducible factor-1α and endothelial nitric oxide synthase were detected in tissues. The levels of hypoxia-inducible factor-1α, endothelial nitric oxide synthase, nitric oxide, and reactive oxygen species in cultured pulmonary artery endothelial cells were examined under hypoxia and/or interleukin-17 treatment. The serum interleukin-17 level was increased in chronic thromboembolic pulmonary hypertension patients. Hypoxia-inducible factor-1α was increased, and endothelial nitric oxide synthase was decreased in chronic thromboembolic pulmonary hypertension pulmonary vascular tissue. After receiving the hypoxia combined with interleukin-17 treatment, pulmonary artery endothelial cells showed increased levels of hypoxia-inducible factor-1α and phospho-endothelial nitric oxide synthase (Thr495) (p = 0.001 and 0.063, respectively) and a decreased level of endothelial nitric oxide synthase (p < 0.001). In addition, the nitric oxide level was significantly decreased (p = 0.001), whereas the reactive oxygen species level was insignificantly increased in pulmonary artery endothelial cells. Chronic thromboembolic pulmonary hypertension patients might experience increased inflammation and hypoxia due to dysregulation of the hypoxia-inducible factor-1α/endothelial nitric synthase pathway in pulmonary artery endothelial cells under inflammation and hypoxia, contributing to the pathogenesis of chronic thromboembolic pulmonary hypertension.

Pulmonary Artery Endothelial Cells from Patients with Pulmonary Arterial Hypertension Exhibit Heterogeneous Responses to Their Mechanical Microenvironment

Pulmonary Artery Endothelial Cells from Patients with Pulmonary Arterial Hypertension Exhibit Heterogeneous Responses to Their Mechanical Microenvironment

Adequate post-ischemic reperfusion of the mouse brain requires endothelial NFAT5

Severity and outcome of strokes following cerebral hypoperfusion are significantly influenced by stress responses of the blood vessels. In this context, brain endothelial cells (BEC) regulate inflammation, angiogenesis and the vascular resistance to rapidly restore perfusion. Despite the relevance of these responses for infarct volume and tissue recovery, their transcriptional control in BEC is not well characterized. We revealed that oxygen and nutrient-deprived BEC activate nuclear factor of activated T-cells 5 (NFAT5)—a transcription factor that adjusts the cellular transcriptome to cope with environmental stressors. We hypothesized that NFAT5 controls the expression of genes regulating the response of BEC in the ischemic brain. The functional relevance of NFAT5 was assessed in mice, allowing the conditional EC-specific knock-out of Nfat5 (Nfat5(EC)−/−). Cerebral ischemia was induced by transient middle cerebral artery occlusion (MCAO) followed reperfusion up to 28 days. While loss of endothelial Nfat5 did not evoke any phenotypic abnormalities in mice under control conditions, infarct volumes, neurological deficits and the degree of brain atrophy were significantly pronounced following MCAO as compared to control animals (Nfat5fl/fl). In contrast, MCAO-induced edema formation, inflammatory processes and angiogenesis were not altered in Nfat5(EC)−/− mice. RNAseq analyses of cultured BEC suggested that loss of NFAT5 impairs the expression of Kcnj2 encoding a potassium channel that may affect reperfusion. In fact, lower levels of KCNJ2 were detected in arterial endothelial cells of Nfat5(EC)−/− versus Nfat5fl/fl mice. Laser speckle contrast imaging of the brain revealed an impaired perfusion recovery in Nfat5(EC)−/− versus Nfat5fl/fl mice after MCAO.Collectively, NFAT5 in arterial BEC is required for an adequate reperfusion response after brain ischemia that is presumably dependent on the maintenance of Kcnj2 expression. Consequently, impairment of the protective role of endothelial NFAT5 results in enlarged infarct sizes and more severe functional deficits of brain functions.

Anandamide Inhibits Vascular Smooth Muscle Migration, Endothelial Adhesion Protein Expression and Monocyte Adhesion of Human Coronary Artery Cells

Endocannabinoids have been shown to play a complex role in the pathophysiology of a number of cardiovascular disorders. In the present study, the effects of the two major endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) were investigated in human coronary artery smooth muscle cells (HCASMC) and human coronary artery endothelial cells (HCAEC) with regard to potential atheroprotective and anti-inflammatory effects. In HCASMC, AEA showed an inhibitory effect on platelet-derived growth factor-induced migration, but not proliferation, independent of major cannabinoid-activatable receptors (CB1, CB2, TRPV1), while 2-AG left both responses unaffected. In HCAEC, AEA at concentrations of 6 and 10 µM significantly inhibited the interleukin (IL)-1β- and lipopolysaccharide (LPS)-stimulated expression of vascular cell adhesion molecule-1 (VCAM-1) and LPS-induced intercellular adhesion molecule-1 (ICAM-1), again independently of the abovementioned receptors. Corresponding effects were observed to a lesser extent in the presence of 2-AG, in most cases not significantly. The detection of activated phosphoproteins as well as experiments with inhibitors of corresponding signaling pathways suggest that AEA interferes with IL-1β-induced VCAM-1 expression via inhibition of protein kinase B/Akt and Src kinase activation and attenuates LPS-induced VCAM-1 and ICAM-1 expression via inhibition of signal transducer and activator of transcription 3 (STAT3) phosphorylation. As expected, AEA also led to a significant inhibition of monocyte adhesion to IL-1β- and LPS-stimulated HCAEC, with siRNA experiments confirming the functional role of VCAM-1 and ICAM-1 in this assay. 2-AG showed a comparatively weaker but, in the case of LPS stimulation, still significant inhibition of adhesion. In summary, the results emphasize the potential of AEA as a protective regulator of atherosclerotic and inflammation-related changes in HCASMC and HCAEC and encourage further corresponding preclinical studies with this endocannabinoid.

Mineralocorticoid receptor antagonism prevents coronary microvascular dysfunction in intermittent hypoxia independent of blood pressure.

Obstructive sleep apnea (OSA), characterized by intermittent hypoxia (IH), and is associated with increased cardiovascular mortality that may not be reduced by standard therapies. Inappropriate activation of the renin-angiotensin-aldosterone system occurs in IH, and mineralocorticoid receptor (MR) blockade has been shown to improve vascular outcomes in cardiovascular disease. Thus, we hypothesized that MR inhibition prevents coronary and renal vascular dysfunction in mice exposed to chronic IH. Human and mouse coronary vascular cells and male C57BL/6J mice were exposed to IH or room air (RA) for 12 hours/day for 3 days (in vitro) and 6 weeks with or without treatments with spironolactone (SPL) or hydrochlorothiazide (HTZ). In vitro studies demonstrated that IH increased MR gene expression in human and mouse coronary artery endothelial and smooth muscle cells. Exposure to IH in mice increased blood pressure, reduced coronary flow velocity reserve (CFVR), and attenuated endothelium-dependent dilation and enhanced vasoconstrictor responsiveness in coronary, but not renal arteries. Importantly, SPL treatment prevented altered coronary vascular function independent of blood pressure as normalization of BP with HTZ did not improve CFVR or coronary vasomotor function. These data demonstrate that chronic IH, which mimics the hypoxia-reoxygenation cycles of moderate-to-severe OSA, increases coronary vascular MR expression in vitro. It also selectively promotes coronary vascular dysfunction in mice. Importantly, this dysfunction is sensitive to MR antagonism by SPL, independent of blood pressure. These findings suggest that MR blockade could serve as an adjuvant therapy to improve long-term cardiovascular outcomes in patients with OSA.

Exploring Bone Morphogenetic Protein-2 and -4 mRNA Expression and Their Receptor Assessment in a Dynamic In Vitro Model of Vascular Calcification.

Vascular calcification (VC) is a dynamic, tightly regulated process driven by cellular activity and resembling the mechanisms of bone formation, with specific molecules playing pivotal roles in its progression. We aimed to investigate the involvement of the bone morphogenic proteins (BMP-2, BMP-4, BMPR-1a/1b, and BMPR-2) system in this process. Our study used an advanced in vitro model that simulates the biological environment of the vascular wall, assessing the ability of a phosphate mixture to induce the osteoblastic switch in human coronary artery smooth muscle cells (HCASMCs). HCASMCs were grown in mono- and co-culture with human coronary artery endothelial cells (HCAECs) in a double-flow bioreactor (LiveBox2 and IVTech), allowing static and dynamic conditions through a peristaltic pump. The VC was stimulated by incubation in a calcifying medium for 7 days. A BMP system Real-Time PCR was performed at the end of each experiment. In monocultures, BMP-2 expression increased in calcified HCASMCs in static (p = 0.01) and dynamic conditions. BMP-4 and the biological receptors were expressed in all the experimental settings, increasing mainly in dynamic flow conditions. In co-cultures, we observed a marked increase in BMP-2 and BMP-4, BMPR-1a (p = 0.04 and p = 0.01, respectively), and BMPR-2 (p = 0.001) in the calcifying setting mostly in dynamic conditions. The increase in BMP-2/4 in co-culture suggests that these genes might promote the switch towards an osteogenic-like phenotype, data also supported by the rise of both BMPR-1a and BMPR-2. Thus, our findings provide insights into the mechanisms by which dynamic co-culture modulates the BMP system activation in an environment mimicking in vivo VC's cellular and mechanical characteristics.

BATF alleviates ox-LDL-induced HCAEC injury by regulating SIRT1 expression in coronary heart disease.

Coronary heart disease (CHD) represents a significant global health concern, arising from an intricate interplay between genetic predisposition and environmental influences, with a pivotal involvement of oxidized low-density lipoprotein (ox-LDL) in the pathophysiology of it. We aimed to elucidate the synergistic dynamics of B cell activating transcription factor (BATF) and Sirtuin 1 (SIRT1) in cell injury caused by ox-LDL, reveal potential therapeutic strategies for CHD. The GSE42148 dataset was used to analyze Differentially expressed genes (DEGs) to construct a gene co-expression network. Then bioinformatics analysis was performed on key modules to select the BATF gene. In vitro experiments were conducted to investigate the protective impact of BATF against human coronary artery endothelial cells (HCAEC) injury induced by ox-LDL. Further investigations probed the synergistic impact of BATF and SIRT1 modulation on cellular apoptosis and damage in the presence of ox-LDL. BATF was significantly down-regulated in the CHD sample of the GSE42148 dataset. In vitro assays have proven that BATF alleviates ox-LDL-induced HCAEC injury. Notably, BATF emerged as a pivotal regulator of SIRT1 expression post ox-LDL exposure. Subsequent experiments underscored the interplay between BATF and SIRT1 in mitigating ox-LDL-induced apoptosis and Lactate Dehydrogenase (LDH) activity elevation, highlighting their collaborative role in cellular protection. The research findings suggested a prospective protective function of BATF in HCAEC injury induced by ox-LDL, likely through the mediation of SIRT1 regulation. These results could offer fresh perspectives on the etiology of CHD and possible treatment avenues.

Unfolded protein response modulates the effects of GHRH antagonists in experimental models of in vivo and in vitro lung injury

ABSTRACT The development of efficient targeted therapies to ameliorate endothelial disorders is of the utmost need, as evident by the devastating outcomes of the recent pandemic. Recent findings suggest that unfolded protein response (UPR) modulates barrier function. In the current study, we reveal that the aforementioned highly conservative mechanism is involved in the protective effects of growth hormone-releasing hormone antagonists (GHRHAnt) in lung injury, both in vivo and in vitro. In bovine pulmonary artery endothelial cells, UPR suppression counteracted the protective effects of GHRHAnt in lipopolysaccharide (LPS)–induced endothelial hyperpermeability. In mouse lungs, UPR activation enhanced the beneficial effects of GHRHAnt against LPS-induced acute lung injury. Our observations – which are focused on lung endothelial cells and tissues – enhance our knowledge on the mechanisms mediating the barrier function and contribute to the development of novel therapies toward sepsis, direct and indirect lung injury. The effects of UPR modulation on the effects of GHRHAnt in other tissues are unknown, and they are the subject of future investigations.

Alk1/Endoglin signaling restricts vein cell size increases in response to hemodynamic cues

Hemodynamic cues are thought to control blood vessel hierarchy through a shear stress set point, where flow increases lead to blood vessel diameter expansion, while decreases in blood flow cause blood vessel narrowing. Aberrations in blood vessel diameter control can cause congenital arteriovenous malformations (AVMs). We show in zebrafish embryos that while arteries behave according to the shear stress set point model, veins do not. This behavior is dependent on distinct arterial and venous endothelial cell (EC) shapes and sizes. We show that arterial ECs enlarge more strongly when experiencing higher flow, as compared to vein cells. Through the generation of chimeric embryos, we discover that this behavior of vein cells depends on the bone morphogenetic protein (BMP) pathway components Endoglin and Alk1. Endoglin (eng) or alk1 (acvrl1) mutant vein cells enlarge when in normal hemodynamic environments, while we do not observe a phenotype in either acvrl1 or eng mutant ECs in arteries. We further show that an increase in vein diameters initiates AVMs in eng mutants, secondarily leading to higher flow to arteries. These enlarge in response to higher flow through increasing arterial EC sizes, fueling the AVM. This study thus reveals a mechanism through which BMP signaling limits vein EC size increases in response to flow and provides a framework for our understanding of how a small number of mutant vein cells via flow-mediated secondary effects on wildtype arterial ECs can precipitate larger AVMs in disease conditions, such as hereditary hemorrhagic telangiectasia (HHT).

Post-transcriptional regulation of IFI16 promotes inflammatory endothelial pathophenotypes observed in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a progressive disease driven by endothelial cell inflammation and dysfunction, resulting in the pathological remodeling of the pulmonary vasculature. Innate immune activation has been linked to PAH development; however, the regulation, propagation, and reversibility of the induction of inflammation in PAH is poorly understood. Here, we demonstrate a role for interferon inducible protein 16 (IFI16), an innate immune sensor, as a modulator of endothelial inflammation in pulmonary hypertension, utilizing human pulmonary artery endothelial cells (PAECs). Inflammatory stimulus of PAECs with IL-1b up-regulates IFI16 expression, inducing proinflammatory cytokine up-regulation and cellular apoptosis. IFI16 mRNA stability is regulated by post-transcriptional m6A modification, mediated by Wilms' tumor 1-associated protein (WTAP), a structural stabilizer of the methyltransferase complex, via regulation of m6A methylation of IFI16. Additionally, m6A levels are increased in the peripheral blood mononuclear cells of PAH patients compared to control, indicating that quantifying this epigenetic change in patients may hold potential as a biomarker for disease identification. In summary, our study demonstrates IFI16 mediates inflammatory endothelial pathophenotypes seen in pulmonary arterial hypertension.

Protein Kinase C-β Inhibition and Survival Signaling after Simulated Cardioplegic Ischemia/Reperfusion in Non-Diabetic and Diabetic Human Coronary Arterial Endothelial Cells.

Cardioplegic ischemia/reperfusion (I/R) injury poses substantial challenges during postoperative recovery, with diabetic patients particularly susceptible to adverse events. Using a model entailing the subjection of human coronary artery endothelial cells (HCAECs) to simulated cardioplegic I/R, we investigated the potential of protein kinase c β (PKC-β) inhibition to augment cellular survival in this context. HCAECs were isolated from harvested coronary arteries of diabetic (D) and nondiabetic (C) patients (N = 4 per group). HCAECs were either cultured in normoxic conditions without drug (D and C), subjected to hypoxia/reoxygenation alone (DH and CH), or subjected to hypoxia/reoxygenation and the PKC-β inhibitor LY333531 (DHT and CHT). Molecular signaling was assessed using immunoblotting. Simulated I/R decreased anti-apoptotic phosphorylated protein kinase b (p-Akt, p = 0.04) and p-Akt:Akt ratio (p = 0.004) in CH versus C, with PKC-β inhibition restoring expression in CHT (p ≤ 0.04). Treatment also increased p-Akt:Akt ratio in DHT versus D (p = 0.03). Anti-apoptotic inducible nitric oxide synthase increased in CHT versus CH (p = 0.003), and pro-apoptotic phosphor-FOXO:FOXO ratio decreased in CHT versus CH (p = 0.001). I/R elevated Bcl-2-associated agonist of cell death (BAD) in CH versus C (p = 0.01), but PKC-β inhibition increased anti-apoptotic p-BAD (p = 0.001) and p-BAD:BAD ratio (p = 0.03) in CHT. I/R also increased cleaved PARP (p < 0.001) and cleaved caspase 3 (p < 0.001) in DH versus D, both of which were reversed by treatment (p < 0.001 for DHT versus DH). PKC-β inhibitor treatment increased pro-survival signaling and decreased pro-apoptotic signaling in nondiabetic and diabetic HCAECs subjected to simulated I/R, with mechanistic differences observed between these cohorts.

Arterial endothelial deletion of hereditary hemorrhagic telangiectasia 2/ Alk1 causes epistaxis and cerebral microhemorrhage with aberrant arteries and defective smooth muscle coverage.

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant vascular disorder with manifestations including severe nose bleeding and microhemorrhage in brains. Despite being the second most common inherited bleeding disorder, the pathophysiological mechanism underlying HHT-associated hemorrhage is poorly understood. HHT pathogenesis is thought to follow a Knudsonian two-hit model, requiring a second somatic mutation for lesion formation. Mutations in activin receptor-like kinase 1 ( ALK1 ) gene cause HHT type 2. We hypothesize that somatic mutation of Alk1 in arterial endothelial cells (AECs) leads to arterial defects and hemorrhage. Here, we mutated Alk1 in AECs in postnatal mice using Bmx(PAC)-Cre ERT2 and found that somatic arterial endothelial mutation of Alk1 was sufficient to induce spontaneous epistaxis and multifocal cerebral microhemorrhage. This bleeding occurred in the presence of tortuous and enlarged blood vessels, loss of arterial molecular marker Efnb2 , disorganization of vascular smooth muscle, and impaired vasoregulation. Our data suggest that arterial endothelial deletion of Alk1 leading to reduced arterial identity and disrupted vascular smooth muscle cell coverage is a plausible molecular mechanism for HHT-associated severe epistaxis. This work provides the first evidence that somatic Alk1 mutation in AECs can cause hemorrhagic vascular lesions, offering a novel preclinical model critically needed for studying HHT-associated epistaxis, and delineating an arterial mechanism to HHT pathophysiology.

LncRNA H19 Promotes Angiogenesis in Mouse Pulmonary Artery Endothelial Cells by Regulating the HIF-1α/VEGF Signaling Pathway.

Persistent pulmonary hypertension of the newborn (PPHN) is a syndrome of acute respiratory failure characterized by systemic hypoxemia and elevated pulmonary arterial pressure, which leads to pathological changes in pulmonary vascular remodeling and endothelial cell function. Long non-coding RNA (lncRNA) H19 has been shown to be involved in the regulation of arterial endothelial cell function, but its regulatory role in PPHN is not fully understood. In the present study, mouse pulmonary artery endothelial cells (MPAECs) were cultured in a hypoxic conditions. Subsequently, the regulatory function of lncRNA H19 on MPAECs was explored by constructing adenoviruses knocking down and overexpressing lncRNA H19. The results revealed that the hypoxic conditions could induce the proliferation and migration of MPAECs, as well as the high expression of lncRNA H19 in MPAECs. Knockdown of lncRNA H19 expression in MPAECs reversed hypoxic environment-induced functional changes in endothelial cells, whereas overexpression of lncRNA H19 further enhanced the proliferation and migration of MPAECs. In addition, lncRNA H19 upregulated the hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) pathway through sponge of miNA-20a-5p, which in turn promoted changes in endothelial cell function. LncRNA H19 may interfere with vascular remodeling in hypoxia-induced pulmonary hypertension by upregulating the expression of HIF-1α and VEGF in vascular endothelial cells.

Panax notoginseng Saponins Improve Angiogenesis in Coronary Heart Disease Based on the microRNA 200a Methylation Pathway.

Improving angiogenesis in the ischemic myocardium is a therapeutic strategy for preventing, reducing, and repairing myocardial injury of coronary artery disease (CAD). Panax notoginseng saponins (PNS) have been widely used in the clinical treatment of cardiovascular diseases, demonstrating excellent efficacy, and can potentially improve angiogenesis in the ischemic myocardium. However, the effects of PNS on angiogenesis and its underlying mechanism of action remain unclear. In this study, we aimed to evaluate the role of PNS in improving angiogenesis after myocardial infarction (MI) and explain the mechanism of PNS in improving angiogenesis in CAD from an epigenetic perspective. The MI rat model was established by ligating the left anterior descending coronary artery permanently. The in vitro model comprised hypoxic human coronary artery endothelial cells (HCEACs). The mice and cells were then treated with PNS. Blood tests, histomorphology, polymerase chain reaction, enzyme-linked immunosorbent assay, Western blotting, and MassARRAY targeted methylation detection analyses were conducted in vivo and in vitro to investigate the potential mechanisms of PNS. Oral PNS significantly improved myocardial injury and activated angiogenesis in MI rats. DNA methylation analysis in vitro revealed that PNS decreased the hypermethylation of microRNA 200a (miR200a). PNS improved angiogenesis in hypoxic human coronary artery endothelial cells (HCEACs) by regulating the vascular endothelial growth factor (VEGF) pathway. Our research shows that PNS can improve angiogenesis in rats with MI and hypoxic HCEACs and affect the level of miR200a promoter methylation and miR200a and VEGF molecular pathways.