Contraction Of Smooth Muscle Cells Research Articles

Diacylglycerol Kinase is a Keystone Regulator of Signaling Relevant to the Pathophysiology of Asthma.

Signal transduction by G protein-coupled receptors (GPCRs), receptor tyrosine kinases (RTKs) and immunoreceptors converge at the activation of phospholipase C (PLC) for the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). This is a point for second-messenger bifurcation where DAG via protein kinase C (PKC) and IP3 via calcium activate distinct protein targets and regulate cellular functions. IP3 signaling is regulated by multiple calcium influx and efflux proteins involved in calcium homeostasis. A family of lipid kinases belonging to DAG kinases (DGK) converts DAG to phosphatidic acid (PA), negatively regulating DAG signaling and pathophysiological functions. PA through a series of biochemical reactions is recycled to produce new molecules of PIP2. Therefore, DGKs act as a central switch in terminating DAG signaling and resynthesis of membrane phospholipids precursor. Interestingly, calcium and PKC regulate the activation of a and z isoforms of DGK that are predominantly expressed in airway and immune cells. Thus, DGK forms a feedback and feedforward control point and plays a crucial role in fine-tuning phospholipid stoichiometry, signaling, and functions. In this review, we discuss the previously underappreciated complex, and intriguing DAG/DGK-driven mechanisms in regulating cellular functions associated with asthma such as contraction and proliferation of airway smooth muscle (ASM) cells, and inflammatory activation of immune cells. We highlight the benefits of manipulating DGK activity in mitigating salient features of asthma pathophysiology and shed light on DGK as a molecule of interest for heterogeneous diseases such as asthma.

Characterization of Ano1 expressing cells in the mouse corpus cavernosum

Background/objectives: Highly coordinated contraction and relaxation of smooth muscle cells (SMCs) is critical to penile function. The Ca2+-activated Cl− channel, Anoctamin-1 (Ano1) plays a role in this as antagonists of this channel inhibit contractile, electrical and intracellular Ca2+ activity. mRNA encoding Ano1 is highly expressed in whole rabbit corpus cavernosum (CC). Despite its significant contribution to erectile function, the specific cell type that expresses Ano1 has not been determined, with previous studies relying on morphological identification of cells alone. Atypical SMCs (ASMCs) expressing platelet derived growth factor receptor-a (PDGFRa; Pdgfra), myosin heavy chain ( Myh11) and Ano1 have been observed in the renal pelvis where they are thought to drive the activity in adjacent SMCs (Grainger et al. 2020; PMID: 32415739). Therefore, the objective of this study is to identify the cell type that expresses Ano1 in the CC. Methods: Cells were isolated from the CC of mice selectively expressing eGFP in PDGFRa+ cells (PDGFRa+-eGFP mice) and SMCs ( Myh11-eGFP mice). Cell suspensions were sorted using fluorescence activated cell sorting (FACS) and evaluated for expression of cell specific markers ( Pdgfra and Myh11) by qPCR. Enriched PDGFRa+ cells and SMCs were examined with ddPCR to determine the expression of Ano1. Protein expression was evaluated using immunofluorescent labeling of frozen CC sections with an antibody targeting Ano1. Results: FACS sorted Myh11-eGFP+ cells expressed Myh11 and Pdgfra. Sorting of PDGFRa-eGFP+ cells revealed two subpopulations, bright and dim. Examination of these two PDGFRa-eGFP+ subpopulations revealed that while both expressed similar levels of Pdgfra, the dim population also expressed Myh11 suggesting that these cells may be similar to ASMCs of the renal pelvis. ddPCR revealed that the PDGFRa-eGFP+ dim population had higher gene copy numbers of Ano1 compared to Myh11-eGFP+ cells. Immunofluorescent labeling of CC sections revealed that Ano1 protein was present in a subpopulation of PDGFRa+ cells. Conclusion: The data presented in this study demonstrates that Ano1 is expressed in mouse CC PDGFRa-eGFP+ dim populations that also express Pdgfra and Myh11; this is similar to ASMCs in the renal pelvis. Future directions include examining the relationship of PDGFRa-eGFP+ dim cells to SMCs and nerve terminals in the CC and to determine if these cells are also present in human CC. This cell population could represent a novel target for the treatment of erectile dysfunction in patients who do not respond to phosphodiesterase inhibitors. Funding: AUA Research Scholar Award to KIH, NIH DK129528 to CAC, NIH P20GM130459 for imaging and molecular cores. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Unraveling the complexity of vascular tone regulation: a multiscale computational approach to integrating chemo-mechano-biological pathways with cardiovascular biomechanics.

Vascular tone regulation is a crucial aspect of cardiovascular physiology, with significant implications for overall cardiovascular health. However, the precise physiological mechanisms governing smooth muscle cell contraction and relaxation remain uncertain. The complexity of vascular tone regulation stems from its multiscale and multifactorial nature, involving global hemodynamics, local flow conditions, tissue mechanics, and biochemical pathways. Bridging this knowledge gap and translating it into clinical practice presents a challenge. In this paper, a computational model is presented to integrate chemo-mechano-biological pathways with cardiovascular biomechanics, aiming to unravel the intricacies of vascular tone regulation. The computational framework combines an algebraic description of global hemodynamics with detailed finite element analyses at the scale of vascular segments for describing their passive and active mechanical response, as well as the molecular transport problem linked with chemo-biological pathways triggered by wall shear stresses. Their coupling is accounted for by considering a two-way interaction. Specifically, the focus is on the role of nitric oxide-related molecular pathways, which play a critical role in modulating smooth muscle contraction and relaxation to maintain vascular tone. The computational framework is employed to examine the interplay between localized alterations in the biomechanical response of a specific vessel segment-such as those induced by calcifications or endothelial dysfunction-and the broader global hemodynamic conditions-both under basal and altered states. The proposed approach aims to advance our understanding of vascular tone regulation and its impact on cardiovascular health. By incorporating chemo-mechano-biological mechanisms into in silico models, this study allows us to investigate cardiovascular responses to multifactorial stimuli and incorporate the role of adaptive homeostasis in computational biomechanics frameworks.

Investigation of the impact of bromodomain inhibition on cytoskeleton stability and contraction

BackgroundInjury to contractile organs such as the heart, vasculature, urinary bladder and gut can stimulate a pathological response that results in loss of normal contractility. PDGF and TGFβ are among the most well studied initiators of the injury response and have been shown to induce aberrant contraction in mechanically active cells of hollow organs including smooth muscle cells (SMC) and fibroblasts. However, the mechanisms driving contractile alterations downstream of PDGF and TGFβ in SMC and fibroblasts are incompletely understood, limiting therapeutic interventions.MethodsTo identify potential molecular targets, we have leveraged the analysis of publicly available data, comparing transcriptomic changes in mechanically active cells stimulated with PDGF and TGFβ. Additional Analysis of publicly available data sets were performed on SMC and fibroblasts treated in the presence or absence of the MYC inhibitor JQ1. Validation of in silico findings were performed with qPCR, immunoblots, and collagen gel contraction assays measure the effect of JQ1 on cytoskeleton associated genes, proteins and contractility in mechanically active cells. Likelihood ratio test and FDR adjusted p-values were used to determine significant differentially expressed genes. Student ttest were used to calculate statistical significance of qPCR and contractility analyses.ResultsComparing PDGF and TGFβ stimulated SMC and fibroblasts identified a shared molecular profile regulated by MYC and members of the AP-1 transcription factor complex. Additional in silico analysis revealed a unique set of cytoskeleton-associated genes that were sensitive to MYC inhibition with JQ1. In vitro validation demonstrated JQ1 was also able to attenuate TGFβ and PDGF induced changes to the cytoskeleton and contraction of smooth muscle cells and fibroblasts in vitro.ConclusionsThese findings identify MYC as a key driver of aberrant cytoskeletal and contractile changes in fibroblasts and SMC, and suggest that JQ1 could be used to restore normal contractile function in hollow organs.

Banxia Xiexin decoction promotes gastric lymphatic pumping by regulating lymphatic smooth muscle cell contraction and energy metabolism in a stress-induced gastric ulceration rat model

Ethnopharmacological relevanceThe traditional Chinese medicine (TCM) formula Banxia Xiexin decoction (BXD) has definite therapeutic effect in treating stress-induced gastric ulceration (SIGU) and many other gastrointestinal diseases, but its effect on gastric lymphatic pumping (GLP) remains unclear. Aim of the studyElucidating the role of GLP in SIGU and BXD treatment, and exploring the molecular mechanisms of GLP regulation. Materials and methodsIn vivo GLP imaging were performed on SIGU rat model, and the lymphatic dynamic parameters were evaluated. Gastric antrum tissues and serum were collected for macroscopic, histopathological and ulcerative parameters analysis. Gastric lymphatic vessel (GLV) tissues were collected for RNA-Seq assays. Differentially expressed genes (DEGs) were screened from RNA-Seq result and submitted for transcriptomic analysis. Key DEGs and their derivative proteins were measured by qRT-PCR and WB. ResultsGLP was significantly suppressed in SIGU rats. BXD could recover GLP, ameliorate stomach lymphostasis, and alleviate the ulcerative damage. Transcriptome analysis of GLV showed the top up-DEGs were concentrated in smooth muscle contraction signaling pathway, while the top the down-DEGs were concentrated in energy metabolism pathways especially fatty acid degradation pathway, which indicated BXD can promote lymphatic smooth muscle contraction, regulate energy metabolism, and reduce fatty acid degradation. The most possible target of these mechanisms was the lymphatic smooth muscle cells (LSMCs) which drove the GLP. This speculation was further validated by the qRT-PCR and WB assessments for the level of key genes and proteins. ConclusionsBy activating the smooth muscle contraction signaling pathway, restoring energy supply, modulating energy metabolism program and reducing fatty acid degradation, BXD effectively recovered GLP, mitigated the accumulation of inflammatory cytokines and metabolic wastes in the stomach, which importantly contributes to its efficacy in treating SIGU.

Phosphorylated CPI-17 and MLC2 as Biomarkers of Coronary Artery Spasm-Induced Sudden Cardiac Death.

Coronary artery spasm (CAS) plays an important role in the pathogeneses of various ischemic heart diseases and has gradually become a common cause of life-threatening arrhythmia. The specific molecular mechanism of CAS has not been fully elucidated, nor are there any specific diagnostic markers for the condition. Therefore, this study aimed to examine the specific molecular mechanism underlying CAS, and screen for potential diagnostic markers. To this end, we successfully constructed a rat CAS model and achieved in vitro culture of a human coronary-artery smooth-muscle cell (hCASMC) contraction model. Possible molecular mechanisms by which protein kinase C (PKC) regulated CAS through the C kinase-potentiated protein phosphatase 1 inhibitor of 17 kDa (CPI-17)/myosin II regulatory light chain (MLC2) pathway were studied in vivo and in vitro to screen for potential molecular markers of CAS. We performed hematoxylin and eosin staining, myocardial zymogram, and transmission electron microscopy to determine myocardial and coronary artery injury in CAS rats. Then, using immunohistochemical staining, immunofluorescence staining, and Western blotting, we further demonstrated a potential molecular mechanism by which PKC regulated CAS via the CPI-17/MLC2 pathway. The results showed that membrane translocation of PKCα occurred in the coronary arteries of CAS rats. CPI-17/MLC2 signaling was observably activated in coronary arteries undergoing CAS. In addition, in vitro treatment of hCASMCs with angiotensin II (Ang II) increased PKCα membrane translocation while consistently activating CPI-17/MLC2 signaling. Conversely, GF-109203X and calphostin C, specific inhibitors of PKC, inactivated CPI-17/MLC2 signaling. We also collected the coronary artery tissues from deceased subjects suspected to have died of CAS and measured their levels of phosphorylated CPI-17 (p-CPI-17) and MLC2 (p-MLC2). Immunohistochemical staining was positive for p-CPI-17 and p-MLC2 in the tissues of these subjects. These findings suggest that PKCα induced CAS through the CPI-17/MLC2 pathway; therefore, p-CPI-17 and p-MLC2 could be used as potential markers for CAS. Our data provide novel evidence that therapeutic strategies against PKC or CPI-17/MLC2 signaling might be promising in the treatment of CAS.

Effect of subchronic use of unsymmetrical dimethylhydrazine on contractile activity of isolated lymphatic vessels

Introduction. Unsymmetric dimethylhydrazine (UDMH, heptyl) is widely used as a rocket fuel. Heptyl belongs to especially dangerous substances (hazard class I). UDMH with chronic intragastric administration has a cardiotropic effect, which served as the basis for studying its effect on the contractile activity of lymphatic vessels, since they are part of the vascular system. In addition, lymphatic vessels are considered as objects similar in terms of parameters of phase contractile activity with the heart and having a certain commonality of regulatory mechanisms of cardiomyocytes and smooth muscle cells of lymphangions.
 Materials and methods. The toxic effect of UDMH was evaluated on a model of isolated rat lymphatic vessels with subchronic intragastric administration of heptyl for 28 days at doses of 0.02; 0.2; and 2 mg/kg.
 Results. The use of UDMH in all studied doses led to a decrease in the contractile activity of lymphatic vessels, which manifested itself in the suppression of the frequency and amplitude of contractions and, as a consequence, the integral indicator – minute productivity. At the same time, the tonic voltage increased dose-dependent. When assessing the state of the endothelium of lymphatic vessels using acetylcholine, a decrease (inversion) of the response of lymphangions to the vasodilator was revealed.
 Limitations of the study. The study was performed on male white rats and does not take into account gender differences in the effect of NDMG on lymphatic vessels. 
 Conclusion. As a result of the study, it was found that UDMH in doses of 0.02; 0.2; and 2 mg/kg causes inhibition of the pumping function of lymphatic vessels, due to a violation of the processes of both excitation and contraction in smooth muscle cells of lymphangions.

Regulatory Effect of Spray-Dried Lactiplantibacillus plantarum K79 on the Activation of Vasodilatory Factors and Inflammatory Responses.

The reduction of nitric oxide (NO) bioavailability in the endothelium induces endothelial dysfunction, contributing to the development of hypertension. Although Lactobacillus consumption decreases blood pressure, intracellular signaling pathways related to hypertension have not been well elucidated. Thus, this study examined the effect of spray-dried Lactiplantibacillus plantarum K79 (LpK79) on NO production, intracellular signaling pathways, and inflammatory responses related to vascular function and hypertension. NO production was assessed in human umbilical vein endothelial cells (HUVECs) treated with LpK79. Endothelial NO synthase (eNOS) and intracellular signaling molecules were determined using Western blot analysis. LpK79 dose-dependently increased NO production and activated eNOS via the phosphoinositide 3-kinase/Akt signaling pathway HUVECs. Moreover, LpK79 mitigated the activation of crucial factors pivotal for vascular contraction in smooth muscle cells, such as phospholipase Cγ, myosin phosphatase target subunit 1, and Rho-associated kinase 2. When HUVECs were treated with LpL79 in the presence of Escherichia coli lipopolysaccharide (LPS), LpK79 effectively suppressed mRNA and protein expression of pro-inflammatory mediators induced by E. coli LPS. These results suggest that LpK79 provided a beneficial effect on the regulation of vascular endothelial function.

317 A 3D printed device for electrophysiological measurement of myometrial smooth muscle cell contractions in vitro

317 A 3D printed device for electrophysiological measurement of myometrial smooth muscle cell contractions in vitro

Preparation of the microcapsules of Atractylodes chinensis volatile oil and its effect on gastric smooth muscle cell contraction

Abstract Atractylodes chinensis volatile oil (ACVO) microcapsules were prepared with chitosan as parietal material. The optimal conditions for encapsulation were investigated by the Response Surface Method (RSM). ACVO microcapsules were characterized by scanning electron microscopy (SEM), particle size analyzer and Fourier Transform infrared spectroscopy (FTIR), respectively. In vitro release properties of ACVO microcapsules were investigated at pH 1.5 and 7.4, respectively. The effects of ACVO microcapsules on the length of rat gastric smooth muscle cells (GSMC), mRNA and protein expression of calmodulin (CaM) and myosin light chain kinase (MLCK) were investigated. Results showed that under optimal conditions, encapsulation efficiency (EE) was 82.19 %. ACVO microcapsules were spherical with a particle size of 1100 nm. ACVO microcapsules had a good release profile at pH 1.5, and the cumulative release within 72 h reached 85.32 %. Cell experiments showed that ACVO microcapsules (0.02, 0.04 μg/mL) had no effect on cell activity, while induced GSMC to contract, and improved the mRNA, protein expressions of CaM and MLCK in GSMC.

Calponin 1 inhibits agonist-induced ERK activation and decreases calcium sensitization in vascular smooth muscle.

Smooth muscle cell (SMC) contraction and vascular tone are modulated by phosphorylation and multiple modifications of the thick filament, and thin filament regulation of SMC contraction has been reported to involve extracellular regulated kinase (ERK). Previous studies in ferrets suggest that the actin-binding protein, calponin 1 (CNN1), acts as a scaffold linking protein kinase C (PKC), Raf, MEK and ERK, promoting PKC-dependent ERK activation. To gain further insight into this function of CNN1 in ERK activation and the regulation of SMC contractility in mice, we generated a novel Calponin 1 knockout mouse (Cnn1 KO) by a single base substitution in an intronic CArG box that preferentially abolishes expression of CNN1 in vascular SMCs. Using this new Cnn1 KO mouse, we show that ablation of CNN1 has two effects, depending on the cytosolic free calcium level: (1) in the presence of elevated intracellular calcium caused by agonist stimulation, Cnn1 KO mice display a reduced amplitude of stress and stiffness but an increase in agonist-induced ERK activation; and (2) during intracellular calcium depletion, in the presence of an agonist, Cnn1 KO mice exhibit increased duration of SM tone maintenance. Together, these results suggest that CNN1 plays an important and complex modulatory role in SMC contractile tone amplitude and maintenance.

Spiritual Meaning Impacts Psychological Distress and Control of Mean Arterial Pressure in Hypertension Patients

Hypertension is a disease that can cause various complications and is made worse by psychological distress, where cases are increasing at the Bangkalan Community Health Center. This research aims to analyze the correlation between spiritual meaning in regulating psychological distress and mean arterial pressure (MAP) in hypertension patients. This research method is correlation analytic with a cross-sectional approach with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guideline. population of 76 patients and a sample of 62 taken using simple random sampling. The independent variable is spiritual meaning, measured using the Daily Spiritual Experience Scale (DSES). Meanwhile, the dependent variable is distress, measured by the Kessler Psychological Distress Scale and the mean arterial pressure (MAP) value. The collected data was then subjected to statistical tests using Spearman ranks with an alpha value of 0.05. The research results show a relationship between spiritual meaning and psychological distress with a p-value of 0.016 < 0.05 and a correlation coefficient of -0.305. Spirituality is also significantly related to the mean arterial pressure (MAP) value with p value 0.005 < 0.05, and the correlation coefficient is -0.351. Spirituality has an impact on reducing psychological distress, affecting the function of the Hypothalamus Pituitary Adrenal (HPA) Axis and Sympathetic Adrenal Medullary (SAM) Axis. The SAM Axis will balance the secretion of norepinephrine (NE) and epinephrine (E), which affects the balance of contraction of smooth cardiac muscle cells, vasoconstriction and vasodilation, heart rate, and normalizes sodium levels so that it can control blood pressure in hypertensive patients.

Indicators of uterine contractile activity in highly productive sows using supraphysiological doses of oxytocin

The use of large doses of oxytocin to sows in the early postpartum period is indicated to normalize lactogenesis, increase immune proteins in colostrum and transitional milk, prevent postpartum complications, and increase the viability of the offspring. However, the effect of these doses of myotropic drug on the contractile activity of the uterus is not shown. The aim of the work was to study the contractile function of the uterus of highly productive sows in the early postpartum period and the peculiarities of its reaction to supraphysiological doses of oxytocin. Scientific and production experience was carried out on the basis of a large pig breeding complex. The object of the study was highly productive sows 16 hours after the completion of normal labor. The hormonal drug oxytocin was administered intra-muscularly to animals at a supraphysiological dose of 75 units. Hysterograms of uterine contractions were recorded by internal hysterography before and immediately after administration of the myotropic drug, as well as one hour after injection. On hysterograms, spontaneous contractile activity of the uterus in highly productive sows was characterized by regular, short-term contractions of the optimal amplitude. Activation of the contractile function of the myometrium occurs 5-7 minutes after injection of the drug. After administration of oxytocin, an increase in the amplitude of contraction of uterine smooth muscle cells was noted by 39.17% (p<0.05), while a longer period of contractions was recorded by 31.64%. The frequency of uterine contractions increased 2.0 times (p<0.01). The contract index was significantly 3.66 times (p<0.05) higher than that in relation to the initial level. After 1 hour after oxytocin administration, an increase in the contraction period by 5.42% was noted, with a decrease in amplitude by 37.87% (p<0.01) and the number of contractions by 49.91% (p<0.01), the contractional index decreased by 3.05 times (p<0.01) relative to the previous level. In relation to the initial level, the contract index was 20.0% higher. At the same time, an increase in the duration of contractions by 38.78% and a decrease in their amplitude by 13.53% were noted. Consequently, oxytocin at a dose of 75 ME not violate the contractile ability of the myometrium. The response of the smooth muscle cells of the uterus to the supraphysiological dose of oxytocin is maximally manifested in the first hour after the administration of the myotropic drug.

Interleukin 31 receptor α promotes smooth muscle cell contraction and airway hyperresponsiveness in asthma

Asthma is a chronic inflammatory airway disease characterized by airway hyperresponsiveness (AHR), inflammation, and goblet cell hyperplasia. Multiple cytokines, including IFNγ, IL-4, and IL-13 are associated with asthma; however, the mechanisms underlying the effects of these cytokines remain unclear. Here, we report a significant increase in the expression of IL-31RA, but not its cognate ligand IL-31, in mouse models of allergic asthma. In support of this, IFNγ, IL-4, and IL-13 upregulated IL-31RA but not IL-31 in both human and mice primary airway smooth muscle cells (ASMC) isolated from the airways of murine and human lungs. Importantly, the loss of IL-31RA attenuated AHR but had no effect on inflammation and goblet cell hyperplasia in mice challenged with allergens or treated with IL-13 or IFNγ. We show that IL-31RA functions as a positive regulator of muscarinic acetylcholine receptor 3 expression, augmenting calcium levels and myosin light chain phosphorylation in human and murine ASMC. These findings identify a role for IL-31RA in AHR that is distinct from airway inflammation and goblet cell hyperplasia in asthma.

PDE4 Phosphodiesterases in Cardiovascular Diseases: Key Pathophysiological Players and Potential Therapeutic Targets

3′,5′-cyclic adenosine monophosphate (cAMP) is a second messenger critically involved in the control of a myriad of processes with significant implications for vascular and cardiac cell function. The temporal and spatial compartmentalization of cAMP is governed by the activity of phosphodiesterases (PDEs), a superfamily of enzymes responsible for the hydrolysis of cyclic nucleotides. Through the fine-tuning of cAMP signaling, PDE4 enzymes could play an important role in cardiac hypertrophy and arrhythmogenesis, while it decisively influences vascular homeostasis through the control of vascular smooth muscle cell proliferation, migration, differentiation and contraction, as well as regulating endothelial permeability, angiogenesis, monocyte/macrophage activation and cardiomyocyte function. This review summarizes the current knowledge and recent advances in understanding the contribution of the PDE4 subfamily to cardiovascular function and underscores the intricate challenges associated with targeting PDE4 enzymes as a therapeutic strategy for the management of cardiovascular diseases.

The Process of Plaque Rupture: The Role of Vasa Vasorum and Medial Smooth Muscle Contraction Monitored by the Cardio-Ankle Vascular Index

A warning sign for impending cardiovascular events is not fully established. In the process of plaque rupture, the formation of vulnerable plaque is important, and oxidized cholesterols play an important role in its progression. Furthermore, the significance of vasa vasorum penetrating the medial smooth muscle layer and being rich in atheromatous lesions should be noted. The cardio-ankle vascular index (CAVI) is a new arterial stiffness index of the arterial tree from the origin of the aorta to the ankle. The CAVI reflects functional stiffness, in addition to structural stiffness. The rapid rise in the CAVI means medial smooth muscle cell contraction and strangling vasa vasorum. A rapid rise in the CAVI in people after a big earthquake, following a high frequency of cardiovascular events has been reported. There are several cases that showed a rapid rise in the CAVI a few weeks or months before suffering cardiovascular events. To explain these sequences of events, we proposed a hypothesis: a rapid rise in the CAVI means medial smooth muscle contraction, strangling vasa vasorum, leading to ischemia and the necrosis of vulnerable plaque, and then the plaque ruptures. In individuals having a high CAVI, further rapid rise in the CAVI might be a warning sign for impending cardiovascular events. In such cases, treatments to decrease the CAVI better be taken soon.

Dexrazoxane does not mitigate early vascular toxicity induced by doxorubicin in mice.

Apart from cardiotoxicity, the chemotherapeutic agent doxorubicin (DOX) provokes acute and long-term vascular toxicity. Dexrazoxane (DEXRA) is an effective drug for treatment of DOX-induced cardiotoxicity, yet it remains currently unknown whether DEXRA prevents vascular toxicity associated with DOX. Accordingly, the present study aimed to evaluate the protective potential of DEXRA against DOX-related vascular toxicity in a previously-established in vivo and ex vivo model of vascular dysfunction induced by 16 hour (h) DOX exposure. Vascular function was evaluated in the thoracic aorta in organ baths, 16h after administration of DOX (4 mg/kg) or DOX with DEXRA (40 mg/kg) to male C57BL6/J mice. In parallel, vascular reactivity was evaluated after ex vivo incubation (16h) of murine aortic segments with DOX (1 μM) or DOX with DEXRA (10 μM). In both in vivo and ex vivo experiments, DOX impaired acetylcholine-stimulated endothelium-dependent vasodilation. In the ex vivo setting, DOX additionally attenuated phenylephrine-elicited vascular smooth muscle cell (VSMC) contraction. Importantly, DEXRA failed to prevent DOX-induced endothelial dysfunction and hypocontraction. Furthermore, RT-qPCR and Western blotting showed that DOX decreased the protein levels of topoisomerase-IIβ (TOP-IIβ), a key target of DEXRA, in the heart, but not in the aorta. Additionally, the effect of N-acetylcysteine (NAC, 10 μM), a reactive oxygen species (ROS) scavenger, was evaluated ex vivo. NAC did not prevent DOX-induced impairment of acetylcholine-stimulated vasodilation. In conclusion, our results show that DEXRA fails to prevent vascular toxicity resulting from 16h DOX treatment. This may relate to DOX provoking vascular toxicity in a ROS- and TOP-IIβ-independent way, at least in the evaluated acute setting. However, it is important to mention that these findings only apply to the acute (16h) treatment period, and further research is warranted to delineate the therapeutic potential of DEXRA against vascular toxicity associated with longer-term repetitive DOX dosing.

Role of protein kinase D1 in vasoconstriction and haemodynamics in rats

AimsProtein kinase D (PKD), once considered an effector of protein kinase C (PKC), now plays many pathophysiological roles in various tissues. However, little is known about role of PKD in vascular function. We investigated the role of PKD in contraction of rat aorta and human aortic smooth muscle cells (HASMCs) and in haemodynamics in rats. Methods and resultsIsometric tension of rat aortic was measured to examine norepinephrine-induced contraction in the presence of PKD, PKC and Rho-kinase inhibitors. Phosphorylation of PKD1, myosin targeting subunit-1 (MYPT1), myosin light chain (MLC), CPI-17 and heat-shock protein 27 (HSP27), and actin polymerization were measured in the aorta. Phosphorylation of MYPT1 and MLC was also measured in HASMCs knocked down with specific siRNAs of PKD 1, 2 and 3. Intracellular calcium concentrations and cell shortening were measured in HASMCs.Norepinephrine-induced aortic contraction was accompanied by increased phosphorylation of PKD1, MYPT1 and MLC and actin polymerization, all of which were attenuated with PKD inhibitor CRT0066101. PKD1 phosphorylation was not inhibited by PKC inhibitor, chelerythrine or Rho kinase inhibitor, fasudil. In HASMCs, the phosphorylation of MYPT1 and MLC was attenuated by PKD1, but not PKD2, 3 knockdown. In HASMCs, CRT0066101 inhibited norepinephrine-induced cell shortening without affecting calcium concentration. Administration of CRT0066101 decreased systemic vascular resistance and blood pressure without affecting cardiac output in rats. ConclusionsPKD1 may play roles in aorta contraction and haemodynamics via phosphorylation of MYPT1 and actin polymerization in a calcium-independent manner.

PKD1 participates in the processing of aortic dissection via regulating vascular smooth muscle cell contraction and MAPK signaling

PKD1 participates in the processing of aortic dissection via regulating vascular smooth muscle cell contraction and MAPK signaling

Abstract P3104: Sex Differences In Vasodilation In Embryonic Coronary Arteries

Sex differences exist in circulatory system and the onset of cardiovascular diseases. These differences have been thought to be due to the vasoprotective effects of estrogen. However, there are also sex differences at the early stages of life, such as the survival rate of extremely preterm infants. The mechanisms in which those sex differences are formed at first remain to be elucidated. Therefore, we analyzed the mechanism of sex differences using fetal mouse hearts. In this study, embryonic day 17.5 mice were used to understand sex differences in cardiovascular system just before they are born. First, for morpho-functional analysis of coronary arteries, hearts were removed from embryonic day 17.5 mice, and angiography was performed using nano-particle ink. The ink was injected from the aorta at a constant pressure to visualize the morphology of coronary arteries. We found a significant sex difference in coronary artery diameters. Male coronary arteries were larger under physiological conditions, on the other hand, female coronary arteries were more dilated in the presence of the NO-donor NOC7 and the ROCK inhibitor Y27632. In addition, the same tendency was observed in sections of mouse hearts at embryonic day 17.5. These findings suggest that female’s coronary arteries are more contractile than males. Next, embryonic day 17.5 mouse hearts were dissociated, then sorted with FACS to obtain endothelial cells for bulk RNA-seq and single-cell RNA-seq. Cells were clustered based on the expression of 8 sex-differential genes to identify the sex of each cell. In line with the result of coronary visualization, Gene Set Enrichment Analysis showed the gene set of smooth muscle cell contraction was upregulated in males. Furthermore, cell-cell communication analysis showed that male endothelin signals were modestly stronger in endothelial cells and smooth muscle cells. These data support our previous observation that male left coronary arteries have a larger diameter but are less reactive to vasodilators, because they may have greater contractile function. In conclusion, this study suggests that functional and morphological sex differences already exist at embryonic day 17.5.