bluuebunny/crossref_metadata_2025_split huggingface dataset:
TRPV4 and TRPC1 Channels Mediate Hemodynamic Stress‐Induced Exacerbation of Pulmonary Hypertension
Authors: Sham James S.K. , Eldridge Lindsey , Paudel Omkar , Moldobaeva Aigul , Wagner Elizabeth 
Published: November 2023

Pulmonary hypertension (PH) is a pathological condition associated with a wide spectrum of diseases with diverse etiologies. It is characterized by progressive pulmonary vascular remodeling, sustained vasoconstriction and enhanced vasoreactivity, resulting in elevated pulmonary vascular resistance and right heart failure. Recent studies suggest that increased hemodynamic stress/stretch in pulmonary vasculature plays important roles in vascular remodeling during the development of PH. However, the mechano‐transduction mechanism for hemodynamic stress in PH is unclear. Previous studies showed that several transient receptor potential (TRP) channels are mechanosensitive in different cell types. In particular, TRPV4, an osmo/mechanosensitive channel, is highly expressed in pulmonary endothelial and arterial smooth muscle cells (PASMCs). We have previously demonstrated that TRPV4 expression is upregulated in PASMCs during PH, and deletion of trpv4 gene delayed and suppressed PH development. Moreover, TRPV4 may form heterotetrameric channels with the store‐operated TRPC1, which is known to play crucial roles in PASMC proliferation and vascular remodeling. In this study, we sought to test the hypothesis that TRPV4 and TRPC1 are important components for mediating the signal of hemodynamic stress in vascular cells during PH. To test this hypothesis, left pulmonary arteries ligation (LPAL) was performed in WT, trpv4−/− and trpc1−/− mice to augment hemodynamic stress in pulmonary vasculature. After one week of recovery, LPAL and sham‐operated mice were exposed to normoxia, chronic hypoxia (CH, 3 week 10% O2), or treated with weekly injections of Sugen‐5416 (20 mg/kg) and exposed to CH for 4 weeks. LPAL had no significant effect on the right ventricular systolic pressure (RVSP) and right ventricular mass index (RVMI, RV/(LV+S)) in normoxic mice, suggesting that the increase in pulmonary blood flow in the right lung is well compensated under control conditions. By contrast, the increase in RVSP and RVMI induced by CH exposure or sugen/hypoxia treatment were significantly enhanced in the LPAL‐operated WT mice compared to the sham‐control, indicating that the increased hemodynamic stress exacerbates PH. More importantly, the PH and RV hypertrophy caused by CH were significantly attenuated in the sham‐operated trpv4−/− and trpc1−/− mice, and LPAL in both types of knockout mice did not caused further increase in RVSP and RVMI. These results, hence, support our hypothesis that TRPV4 and TRPC1 channels play an essential role in mediating the hemodynamic stress‐induced alterations in vascular properties during PH; and they may be considered as novel targets for comprehensive treatment of PH.Support or Funding InformationThis work is supported in part by NIH grant HL075134
Three‐dimensional Characterization of Occlusive Lesions in Pulmonary Arterial Hypertension
Authors: Francis Christopher Michael , Oshima Kaori , Baghaei Neelufar , Jeon Dayoung , Labat Sydney , Oka Masahiko , Stevens Troy 
Published: November 2023

Pulmonary arterial hypertension (PAH) includes a vasculopathy of fixed occlusive lesions in small pulmonary arteries. Evaluation of vascular lesions in PAH has relied on two‐dimensional histological preparations and morphological grading methodologies to evaluate lesion incidence and severity. However, this approach fails to acknowledge the structure of vascular lesions in situ and is inherently prone to investigator bias, leading to controversy regarding the hemodynamic impact of occlusive lesions in PAH and the possible misidentification of lesions within the lung vasculature. Therefore, we developed a semi‐automated, three‐dimensional approach to the analysis of composite serial histological sections to examine the geometry of vascular lesions in PAH. Given that recent studies of vascular morphology in PAH demonstrate that the progression of occlusive lesions has both temporal and spatial components, we tested the hypothesis that occlusive lesions within pulmonary arteries in PAH vary in composition and severity along the length of vessel segments. Using Sugen/hypoxia treated PAH rats, we found that lesion composition and severity was a complex function of vessel length, where von Willebrand factor‐positive endothelium and luminal occlusion surrounding plexiform lesion sites formed a highly variable continuum. These results suggest that the contribution of occlusive lesions to the pathophysiology of PAH may be misrepresented, and underscore the necessity of an unbiased approach to the anatomical characterization of the vasculopathy of PAH.Support or Funding InformationSupported by NIH HL66299 and HL60024.
Pulmonary artery input impedance reflects histological changes in the pulmonary artery in Sugen/Hypoxia pulmonary hypertension model
Authors: Nishikawa Takuya , Saku Keita , Kishi Takuya , Tsutsui Hiroyuki , Sunagawa Kenji 
Published: November 2023

BackgroundPulmonary hypertension (PH) is characterized by elevated pulmonary arterial pressure resulting from pulmonary vasoconstriction and remodeling, and leads to end‐stage right heart failure. Although pulmonary arterial resistance (R) has been a standard measure to characterize the mechanical properties of pulmonary arterial system, arterial input impedance (Z) provides far more detailed dynamic as well as static mechanical characteristics of pulmonary artery. We hypothesized that Z reflects histological changes in the pulmonary artery in PH.MethodIn Sprague‐Dawley rats, we induced PH by an injection of SU5416 (20 mg/kg) and 3 weeks exposure to 10% oxygen. We conducted acute experiments under anesthesia at 0, 1, 3 and 8 (n=7 each) weeks after SU5416 injection. We measured pulmonary artery flow (F) and pressure (P) under irregular pacing. We Fourier transformed both F and P to derive Z and fitted the 2‐element Windkessel model to Z to estimated R and elastance (E). After the hemodynamic measurements, we harvested the lung. In histology, we measured the pulmonary arterial cross sectional area within the external elastic lamina (AEEL) and that within the internal elastic lamina (AIEL) and indexed the loss of luminal area by LLA=(AELL‐AILL)/AELL.ResultPH progressively increased mean P (Baseline: 18.8 ± 1.0, 1W: 26.0 ± 3.1, 3W: 45.6 ± 5.4, 8W: 63.9 ± 13.4 mmHg, p<0.01), whereas F remained unchanged (Baseline: 34.7 ± 5.9, 1W: 36.9 ± 7.4, 3W: 32.5 ± 4.5, 8W: 31.8 ± 8.7 ml/min, n.s.). This is translated into the progressive increases in Z without changing its dynamic properties (Fig. 1). Estimated R (Baseline: 17.4±3.9, 1W: 29.7±8.6, 3W: 55.7±9.0, 8W: 70.2±18.2 mmHg/ml/sec, p<0.01) and E (Baseline: 267±48, 1W: 424±101, 3W: 619±213, 8W: 709±239 mmHg/ml, p<0.01) (Fig. 2) increased, while the resultant time constant (R/E) remained unaltered. LLA of arteries with the outer diameter (OD) of <50μm (LLA50) increased with the progression of PH and reached more than 50% (Baseline: 0.18±0.01, 1W: 0.29±0.02, 3W: 0.43±0.06, 8W: 0.52±0.03, p<0.01). In contrast, LLA of artery with 50<OD<100 μm (LLA100) also increased with the progression of PH, but remained less than 30% (Baseline: 0.12±0.02, 1W: 0.20±0.03, 3W: 0.24±0.04, 8W: 0.27±0.03, p<0.01) (Fig. 2).ConclusionPH progressively increases R, E, LLA50 and LLA100 indicating arterial wall thickening and loss of luminal area. Taken together, in PH, we conjecture that increases in LLA50 contribute to increase R, whereas those in LLA100 may not contribute much to increase R. Increases in LLA100 at least in part contribute to increase E. Thus, Z closely couples with pulmonary arterial histology and may serve as a new tool to assess the disease progression in PH patients.
PHD2 Deficiency Induces Obliterative Vascular Remodeling and Severe PAH through Nitrative Stress and Caveolin‐1 Downregulation
Authors: Dai Zhiyu , Zhu Maggie M. , Zhao You‐Yang 
Published: November 2023

BackgroundPulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary vascular resistance and progressive vascular remodeling. Our recent study for the first time demonstrated that loss of hypoxia inducible factor (HIF) prolyl‐4 hydroxylase 2 (PHD2) in endothelial cells and bone marrow cells in mice induces severe PAH with obliterative pulmonary vascular remodeling and plexiform‐like lesions recapitulating clinical PAH. Increased oxidative/nitrative stress is a hall marker of clinical PAH and Caveolin‐1 (Cav1) is an important regulator of oxidative/nitrative stress and the pathogenesis of clinical PAH. It is unclear whether Cav1 deficiency and nitrative stress are involved in the pathogenesis of severe PAH in this mouse model.MethodsMice with Tie2Cre‐mediated disruption of Egln1 (encoding PHD2) (Egln1 CKO), Egln1 and Hif2a (EH2 DKO), and mice with Egln1 disruption and Cav1 transgene (expressing Cav1 in endothelial cells) (Egln1 CKO/Tg) were generated. Western blotting and immunostaining were performed to quantify nitration stress and Cav1 expression. MnTMPyP (a superoxide scavenger) and Tempol (a radical scavenger) were administrated to Egln1 CKO mice. Right ventricular systolic pressure (RVSP) and RV/(LV+S) ratio, indicator of RV hypertrophy, were measured. Pulmonary vascular remodeling were assessed by histological examination. Echocardiography was used to measure RV and PA function.ResultsNitrotyrosine was markedly increased in Egln1 CKO mouse lungs and normalized in EH2 DKO mouse lungs. Both MnTMPyP and Tempol treatment inhibited RVSP increase and RV hypertrophy, and decreased medial thickness and muscularization of distal pulmonary arterials in Egln1 CKO mice. Mechanistically, endothelial Cav1 expression was decreased in Egln1 CKO mouse lungs and normalized in EH2 DKO mice. Restored Cav1 expression in Egln1 CKO/Tg mice inhibited RVSP and RV hypertrophy and resulted in normalization of RV and PA function and pulmonary vascular remodeling. Both pharmacological and genetic approaches promoted survival of Egln1 CKO mice.ConclusionThese data show that loss of endothelial PHD2 suppresses Cav1 expression in a HIF‐2α dependent manner. Decrease of Cav1 expression and resultant activation of nitrative stress contribute to the severe vascular remodeling and PAH in Egln1 CKO mice. Thus, targeting nitrative stress and restoring Cav1 expression are potentially effective approaches for treatment of PAH.Support or Funding InformationNIH grants R01HL123957, R01HL125350, R01HL133951, and P01HL077806 (Project 3) to Y.Y.Z, AHA postdoctoral fellowship grant 15POST25700124 to Z.D.
Effects of inhibition of MAPK14 and PDE4 signaling pathways on β‐aminopropionitrile fumarate‐induced thoracic aortic aneurysm and dissection in rats
Authors: WANG JIUN‐JR , Yang Yu‐Chun , Wu Nan‐Chun 
Published: November 2023

ObjectivesThoracic aortic aneurysm (TAA) is a virulent and clinical silent disease. The overall mortality rate of a rupture or dissection of TAA could be above 90% in 30 days. TAA grows slowly, and 95% of people have no symptoms prior to its rupture or dissection. To date, treatment strategy for TAA has been limited by elective surgery, being put on observation with treatments of b‐blocking agents or endovascular stent‐graft therapy, while any surgery carries risks and the protective efficacy of b‐blockers or endovascular therapy is inconclusive. β‐aminopropionitrile fumarate (BAPN) is a potent irreversible inhibitor of lysyl oxidase, an enzyme initiating the crosslink formations between collagens and elastin, and mediating extracellular matrix remodeling. Using BAPN, we developed a rat model of TAA that leads to consistent aortic dissections. Genechip analysis of TAA tissues revealed highly upregulated mitogen‐activated protein kinases (MAPKs) and phosphodiesterases (PDEs) expressions. In this study, we aimed to examine efficacy of MAPK and/or PDE inhibition against the progression of TAA and its fateful consequence, dissections.MethodsThis study was conducted in 4 week old Sprague‐Dawley male rats, divided in two groups, sham and BAPN‐treated. The latter was further divided into 4 subgroups; they were treated intraperitoneally with p38 MAPK inhibitor (SB203580, 2 mg/kg, i.p.), PDE4D2 inhibitor (ibudilast, 5 mg/kg), SB203580+ ibudilast and equal amount of saline, respectively. We measured the body weight, food and water consumption daily, noninvasive tail‐cuff pressure every other day, and invasive ventricular pressure‐volume and aortic pressure and flow at 4 weeks. Aortic tissues were subjected to histological, transmission electron microscopic, protein and gene expression analysis.ResultsThere were no major differences in body weight, food and water consumption among different groups. BAPN did not appear to affect ventricular function, but increased reflected waves and reduced aortic compliance. Fig. 1 showed that smooth muscle cells disintegrated and elastin and collagen fragmented en masse after 4 weeks' BAPN treatment. Either p38 MAPK or PDE4D2 inhibitor treatment attenuated structural deterioration, whereas treatment with both inhibitors exhibited synergetic protective advantages. MMP‐2, MMP‐9, COX‐2 and TGF‐β1 protein expression and NF‐κB and CAMK II gene expression were reduced by SB203580 or ibudilast, and most significantly by combined treatment.ConclusionMAPKs and PDEs may play an important role in the progression of vascular degeneration of TAA. Inhibitions of both p38 MAPK and PDE4D2 attenuated MMP‐2, MMP‐9, COX‐2 and TGF‐β1 protein and NF‐κB and CAMK II gene expressions and protected vascular structures.Support or Funding InformationSupported by the Ministry of Science and Technology of Taiwan to Dr. Jiun‐Jr Wang (105‐2320‐B‐030 ‐008)
Involvement of inhibitor kappa B kinase 2 (IKK2) in the regulation of vascular tone
Authors: Youngin Kwon , Soo‐Kyoung Choi , Seonhee Byeon , Young‐Ho Lee 
Published: November 2023

Inhibitor kappa B kinase 2 (IKK2) plays an essential role in the activation of nuclear factor kappa B (NF‐kB). Recently, it has been suggested that IKK2 acts as a myosin light chain kinase (MLCK) and contributes to vasoconstriction in mouse aorta. However, the underlying mechanisms are still unknown. Therefore, we investigated whether IKK2 acts as a MLCK or regulates the activity of myosin light chain phosphatase (MLCP). We used 12‐week old Sprague Dawley rats and measured vessel diameter of mesenteric artery using pressure myograph. SC‐514 (IKK2 inhibitor, 50 μM) induced relaxation in the mesenteric arteries pre‐contracted with 70 mM high K+ solution or U‐46619 (thromboxane analogue, 5 μM). The relaxation induced by SC‐514 was increased in the arteries pre‐contracted with U‐46619 compared to those with 70 mM high K+ solution. In the absence of intracellular Ca2+, U‐46619 still induced contraction, which was decreased by SC‐514. Furthermore, U‐46619‐induced contraction was decreased by SC‐514 in the presence of MLCK inhibitor ML‐7 (10 μM). We demonstrated that IKK2 is involved in the vascular contraction and contributes to regulation of MLCP.Support or Funding InformationThis work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science, ICT & Future Planning) (No. 2016R1C1B1006504).
U46619‐induced contraction is impaired by COX activity in coronary arteries from renal hypertensive rats
Authors: de Paula Tiago Dal‐Cin , Grando Marcella Daruge , Bendhack Lusiane Maria 
Published: November 2023

IntroductionThe coronary vascular bed is responsible for the proper myocardial blood supply and cardiac work. The vascular endothelium controls the vascular tone by the production and/or release of relaxing factors and contractile factors. In cardiovascular diseases like hypertension this balance can be impaired with increased prostanoids production like thromboxane derived from COX and TP receptors activation. Therefore, this work aimed to evaluate the contraction induced by the TP receptors agonist tromboxane analogue (U46619) in renal hypertensive (2K‐1C) and normotensive (2K) coronary arteries. The procedures were approved by the Ethics Committee: USP‐2015.1.441.60.7.MethodsHypertension was induced by surgery in rats. After six weeks, the rats were killed, the heart was removed and placed in ice cold Krebs solution to isolate the septal coronary arteries. The vessels were mounted in microvessels myograph and stimulated with 120 mM KCl and concentration‐effect curves were performed to 5‐hydroxytryptamine (5‐HT, 10 nM–100 μM) following the relaxation to acetylcholine (10 μM). In addition, concentration‐effect curves were constructed to U46619 (10 nM–10 μM) in the absence (Control) or in the presence of COX inhibitor (Indomethacin, 10 μM), selective COX inhibitors of COX‐1 (SC560, 10 μM) and COX‐2 (SC236, 10 μM). The coronary arteries were collected and frozen at −80° C to measure COX‐1 and COX‐2 expression. Data were analyzed by student's t test and one way ANOVA with Dunnet's post‐test (P<0.05).ResultsThe coronary diameter (2K: 337.4 ± 29.9 vs 2K‐1C: 260.4 ± 27.6 μm), the contraction induced by KCl (2K: 4.28 ± 0.65 vs 2K‐1C: 2.98 ± 0.58 mN) and the acetylcholine‐induced relaxation (2K: 77.5 ± 6.5% vs 2K‐1C: 68.2 ± 14.0%) were not different. COX‐1 expression was not different between 2K and 2K‐1C rats (P=0.054). However, COX‐2 expression was higher in 2K‐1C than in 2K (P=0.02). Contraction‐induced by U46619 presented similar pD2 values in 2K (6.83 ± 0.17, n=5) and 2K‐1C (6.52 ± 0.10, n=6) but the maximum effect (ME) was lower in 2K‐1C (87.5 ± 17.0%) than in 2K (149.8 ± 13.1%). All the COX inhibitors used did not change the pD2 and ME in 2K coronary arteries. However, indomethacin increased the ME in 2K‐1C to 162.9 ± 16.9%, n=4 and SC560 increased the pD2 (7.33 ± 0.20, n=5).ConclusionOur results indicate that the contractile response induced by U46619 is impaired in 2K‐1C coronary arteries due to the production of relaxant factor derived from COX activity.Support or Funding InformationFinancial Support: CAPES, CNPq, FAPESP
Heparin Receptor Transmembrane Protein 184A (TMEM184A) Regulates Zebrafish Angiogenesis
Authors: Farwell Sara Lynn N , Reylander Kimberly G , Iovine M Kathryn , Lowe‐Krentz Linda J 
Published: November 2023

Angiogenesis is the formation of new vasculature from existing vasculature and occurs normally during embryonic development, wound healing, and inflammation. Angiogenesis is tightly controlled by several regulators. Disruption of the balance between positive and negative regulators can result in pathological angiogenesis. Abnormal angiogenesis is implicated in several serious diseases, including cardiovascular disease, stroke, diabetes, cancers, and many others. Heparin and/or heparan sulfates (HS) play an important role during in angiogenesis by interacting with both proangiogenic and inhibitory factors. For example, heparin/HS has been shown to act as a scaffold between the major proangiogenic regulator vascular endothelial growth factor (VEGF) and its receptor (VEGFR2). We recently identified transmembrane protein 184A (TMEM184A) as the heparin receptor in vascular endothelial and smooth muscle cells. In vitro, TMEM184A specifically interacts with heparin/HS to mediate anti‐inflammatory and anti‐proliferative growth factor signaling in vascular cells. To examine the expression and function of the heparin receptor TMEM184A in vivo, we employed the zebrafish regenerating fin. We used the Tg(fli1:eGFP) transgenic line to easily visualize vascular regeneration. Immunofluorescence data show that TMEM184A is expressed specifically in endothelial cells in ontogenic and regenerating vasculature. TMEM184A colocalizes with GFP (the endothelial cells) in both arteries and veins in ontogenic fin rays, and TMEM184A expression matches the regenerating pattern of GFP over several days after amputation. In regenerating fins injected with heparin, we observe abnormal vascular regeneration characterized by incomplete vessels and a reduction in total and vascular regeneration length within 24 hours after injection. Remarkably, transient knockdown (≤ 24 hours) of TMEM184A using morpholino‐mediated strategies in regenerating fins results in a significant increase in endothelial cells in highly disorganized vasculature. These data are directly comparable to what we have reported in vitro. Our studies indicate that the heparin receptor TMEM184A plays a regulatory role during angiogenesis. It is important to continue to elucidate the mechanism(s) behind the function of TMEM184A and determine its potential for therapeutic targeting in pathological angiogenesis. Additionally, information detailing its function in vivo could be used to improve current heparin‐based therapies used in the prevention and control of cardiovascular disease and stroke.Support or Funding InformationThis work was supported by NIH grant HL536104 to LLK.
Acrolein‐Induced Epigenetic Modification of Histone 3 in Rat Vascular Smooth Muscle Cells
Authors: Esmaeili Mahsa , Philips Mathew Omana , Ranganna Kasturi , Joseph Mathew , Yousefipour Zivar 
Published: November 2023

ObjectiveEnvironmental pollutants can exacerbate disease conditions by affecting chromatin structure and ultimately regulating gene expression. Acetylation of histone lysine has been reported to contribute to gene expression while the methylation results in gene inactivation. Acrolein, an environmental pollutant and a major component of cigarette smoke, has been implicated in cardiovascular toxicity and several neurological disorders such as Alzheimer's disease. N‐acetyl cysteine (NAC), a precursor of glutathione transferase, has been reported to prevent acrolein toxicity in cell culture. The goal of the present study was to investigate the effects of acrolein on modification of histone 3, lysine 9 residue (H3K9) in rat's vascular smooth muscle cells (VSMCs) in the present and absent of NAC.Design and methodVSMCs were treated with 2 and 3 μg/ml of acrolein for 1, 6 and 24 hours in the present or absent of 0.2 mM NAC. At the end of the treatment, MTS essay was used to check cells viability. Western blot analysis was used to determine changes in H3K9 tri‐methylation and acetylation. Additionally, immunofluorescence staining was used to analysis cellular localization of H3K9 acetylation and methylation.ResultsCells treated with 2 and 3 μg/ml of acrolein exhibited the highest toxicity at 6 hours incubation. Acrolein exposed VSMC displayed induction of histone H3K9 acetylation for all concentrations and time periods. The most significant induction of acetylation (30% at 2 μg/ml] and 46% [3 μg/ml]) and tri‐methylation (37% [2 μg/ml] & 65% [3 μg/ml]) occurred at 6 hours incubation. Co‐treated VSMCs with acrolein and N‐acetyl cysteine reduced H3K9 acetylation (100% for both 2 and 3 μg/ml), and tri‐methylation (115% & 125% for 2 and 3 μg/ml respectively). Immunofluorescence staining further confirmed changes in acetylation and tri‐methylation in acrolein treated VSCMs with or without NAC.ConclusionsBased on our data we are concluding that effect of acrolein on VSCMs is partially due to alterations of H3K9 methylation and acetylation which can be prevented with addition of 0.2 mM NAC.Support or Funding InformationNIH SC3GM103746‐03