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Sehgal A, Steenhorst JJ, Mclennan DI, Merkus D, Ivy D, McNamara PJ. The Left Heart, Systemic Circulation, and Bronchopulmonary Dysplasia: Relevance to Pathophysiology and Therapeutics. J Pediatr 2020; 225:13-22.e2. [PMID: 32553872 DOI: 10.1016/j.jpeds.2020.06.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/06/2020] [Accepted: 06/09/2020] [Indexed: 12/25/2022]
Affiliation(s)
- Arvind Sehgal
- Monash Children's Hospital, Monash University, Melbourne, Australia; Department of Pediatrics, Monash University, Melbourne, Australia.
| | - Jarno J Steenhorst
- Department of Cardiology, Erasmus MC, Rotterdam, the Netherlands; Department of Pediatrics, Erasmus MC, Rotterdam, the Netherlands
| | - Daniel I Mclennan
- Department of Pediatrics, University of Iowa Children's Hospital, Dr, Iowa City, IA; Internal Medicine, University of Iowa Children's Hospital, Dr, Iowa City, IA
| | - Daphne Merkus
- Department of Cardiology, Erasmus MC, Rotterdam, the Netherlands; Department of Pediatrics, Erasmus MC, Rotterdam, the Netherlands; Institut für Chirurgische Forschung, Klinikum Universität München, Ludwig Maximillian Universität München, München, Germany
| | - Dunbar Ivy
- Pediatric Cardiology, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO
| | - Patrick J McNamara
- Department of Pediatrics, University of Iowa Children's Hospital, Dr, Iowa City, IA; Internal Medicine, University of Iowa Children's Hospital, Dr, Iowa City, IA
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Kitagawa MG, Reynolds JO, Durgan D, Rodney G, Karmouty‐Quintana H, Bryan R, Pandit LM. Twik-2 -/- mouse demonstrates pulmonary vascular heterogeneity in intracellular pathways for vasocontractility. Physiol Rep 2019; 7:e13950. [PMID: 30632293 PMCID: PMC6328926 DOI: 10.14814/phy2.13950] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/06/2018] [Accepted: 11/15/2018] [Indexed: 11/24/2022] Open
Abstract
We have previously shown Twik-2-/- mice develop pulmonary hypertension and vascular remodeling. We hypothesized that distal pulmonary arteries (D-PAs) of the Twik-2-/- mice are hypercontractile under physiological venous conditions due to altered electrophysiologic properties between the conduit and resistance vessels in the pulmonary vascular bed. We measured resting membrane potential and intracellular calcium through Fura-2 in freshly digested pulmonary artery smooth muscles (PASMCs) from both the right main (RM-PA) and D-PA (distal) regions of pulmonary artery from WT and Twik-2-/- mice. Whole segments of RM-PAs and D-PAs from 20 to 24-week-old wildtype (WT) and Twik-2-/- mice were also pressurized between two glass micropipettes and bathed in buffer with either arterial or venous conditions. Abluminally-applied phenylephrine (PE) and U46619 were added to the buffer at log increments and vessel diameter was measured. All values were expressed as averages with ±SEM. Vasoconstrictor responses did not differ between WT and Twik-2-/- RM-PAs under arterial conditions. Under venous conditions, Twik-2-/- RM-PAs showed an increased sensitivity to PE with a lower EC50 (P = 0.02). Under venous conditions, Twik-2-/- D-PAs showed an increase maximal vasoconstrictor response to both phenylephrine and U46619 compared to the WT mice (P < 0.05). Isolated PASMCs from Twik-2 -/- D-PA were depolarized and had higher intracellular calcium levels compared to PASMCs from RM-PA of both WT and Twik-2-/- mice. These studies suggest that hypercontractile responses and electrophysiologic properties unique to the anatomic location of the D-PAs may contribute to pulmonary hypertensive vasculopathy.
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Affiliation(s)
| | | | | | | | | | | | - Lavannya M. Pandit
- Baylor College of MedicineHoustonTexas
- Michael E.DeBakey Veterans Affairs Medical CenterHoustonTexas
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North K, Bisen S, Dopico AM, Bukiya AN. Tyrosine 450 in the Voltage- and Calcium-Gated Potassium Channel of Large Conductance Channel Pore-Forming (slo1) Subunit Mediates Cholesterol Protection against Alcohol-Induced Constriction of Cerebral Arteries. J Pharmacol Exp Ther 2018; 367:234-244. [PMID: 30115756 DOI: 10.1124/jpet.118.250514] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/15/2018] [Indexed: 12/29/2022] Open
Abstract
Alcohol (ethanol) at physiologically relevant concentrations (<100 mM) constricts cerebral arteries via inhibition of voltage- and calcium-gated potassium channels of large conductance (BK) located in vascular smooth muscle (VSM). These channels consist of channel-forming slo1 (cbv1, KCNMA1) and accessory beta1 (KCNMB1) subunits. An increase in VSM cholesterol (CLR) via either dietary CLR intake or in vitro CLR enrichment was shown to protect against endothelium-independent, alcohol-induced constriction of cerebral arteries. The molecular mechanism(s) of this protection remains unknown. Here, we demonstrate that CLR enrichment of de-endothelialized middle cerebral arteries (MCAs) of rat increased CLR content in the VSM in a concentration-dependent manner. CLR enrichment blunted MCA constriction evoked by 18-75 mM but not by 100 mM alcohol. MCA enrichment with coprostanol (COPR) also blunted vasoconstriction by 50 mM alcohol, despite the fact that COPR and CLR differ in their ability to modify several major physical properties of the bilayer. CLR protection against 50 but not 100 mM alcohol was also observed in C57BL/6 and KCNMB1 knockout (KO) mice. Permeabilization of KCNMA1 KO MCAs with Y450Fcbv1 totally ablated CLR, but not COPR protection against vasoconstriction by 50 mM alcohol. Thus, CLR and alcohol interact at the level of the BK channel slo1 subunit, with Y450 being critical for CLR protection against alcohol-induced vasoconstriction. We document for the first time a functional competition between CLR and alcohol in regulating cerebral artery diameter and a critical role of a single amino acid within the BK channel pore-forming subunit in controlling CLR-alcohol interaction at the organ level.
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Affiliation(s)
- Kelsey North
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Shivantika Bisen
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Alex M Dopico
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Anna N Bukiya
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
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Farías JG, Herrera EA, Carrasco-Pozo C, Sotomayor-Zárate R, Cruz G, Morales P, Castillo RL. Pharmacological models and approaches for pathophysiological conditions associated with hypoxia and oxidative stress. Pharmacol Ther 2015; 158:1-23. [PMID: 26617218 DOI: 10.1016/j.pharmthera.2015.11.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hypoxia is the failure of oxygenation at the tissue level, where the reduced oxygen delivered is not enough to satisfy tissue demands. Metabolic depression is the physiological adaptation associated with reduced oxygen consumption, which evidently does not cause any harm to organs that are exposed to acute and short hypoxic insults. Oxidative stress (OS) refers to the imbalance between the generation of reactive oxygen species (ROS) and the ability of endogenous antioxidant systems to scavenge ROS, where ROS overwhelms the antioxidant capacity. Oxidative stress plays a crucial role in the pathogenesis of diseases related to hypoxia during intrauterine development and postnatal life. Thus, excessive ROS are implicated in the irreversible damage to cell membranes, DNA, and other cellular structures by oxidizing lipids, proteins, and nucleic acids. Here, we describe several pathophysiological conditions and in vivo and ex vivo models developed for the study of hypoxic and oxidative stress injury. We reviewed existing literature on the responses to hypoxia and oxidative stress of the cardiovascular, renal, reproductive, and central nervous systems, and discussed paradigms of chronic and intermittent hypobaric hypoxia. This systematic review is a critical analysis of the advantages in the application of some experimental strategies and their contributions leading to novel pharmacological therapies.
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Affiliation(s)
- Jorge G Farías
- Facultad de Ingeniería y Ciencias, Departamento de Ingeniería Química, Universidad de la Frontera, Casilla 54-D, Temuco, Chile
| | - Emilio A Herrera
- Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Chile; International Center for Andean Studies (INCAS), Universidad de Chile, Chile
| | | | - Ramón Sotomayor-Zárate
- Centro de Neurobiología y Plasticidad Cerebral (CNPC), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Chile
| | - Gonzalo Cruz
- Centro de Neurobiología y Plasticidad Cerebral (CNPC), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Chile
| | - Paola Morales
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile, Chile
| | - Rodrigo L Castillo
- Programa de Fisiopatología, ICBM, Facultad de Medicina, Universidad de Chile, Chile.
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Fernández JA, Bankhead P, Zhou H, McGeown JG, Curtis TM. Automated detection and measurement of isolated retinal arterioles by a combination of edge enhancement and cost analysis. PLoS One 2014; 9:e91791. [PMID: 24626349 PMCID: PMC3953588 DOI: 10.1371/journal.pone.0091791] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 02/13/2014] [Indexed: 02/04/2023] Open
Abstract
Pressure myography studies have played a crucial role in our understanding of vascular physiology and pathophysiology. Such studies depend upon the reliable measurement of changes in the diameter of isolated vessel segments over time. Although several software packages are available to carry out such measurements on small arteries and veins, no such software exists to study smaller vessels (<50 µm in diameter). We provide here a new, freely available open-source algorithm, MyoTracker, to measure and track changes in the diameter of small isolated retinal arterioles. The program has been developed as an ImageJ plug-in and uses a combination of cost analysis and edge enhancement to detect the vessel walls. In tests performed on a dataset of 102 images, automatic measurements were found to be comparable to those of manual ones. The program was also able to track both fast and slow constrictions and dilations during intraluminal pressure changes and following application of several drugs. Variability in automated measurements during analysis of videos and processing times were also investigated and are reported. MyoTracker is a new software to assist during pressure myography experiments on small isolated retinal arterioles. It provides fast and accurate measurements with low levels of noise and works with both individual images and videos. Although the program was developed to work with small arterioles, it is also capable of tracking the walls of other types of microvessels, including venules and capillaries. It also works well with larger arteries, and therefore may provide an alternative to other packages developed for larger vessels when its features are considered advantageous.
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Affiliation(s)
- José A. Fernández
- Centre for Experimental Medicine, The Queen’s University of Belfast, Belfast, United Kingdom
- * E-mail:
| | - Peter Bankhead
- Centre for Cancer Research and Cell Biology, The Queen’s University of Belfast, Belfast, United Kingdom
| | - Huiyu Zhou
- School of Electronics, Electrical Engineering and Computer Science, The Queen’s University of Belfast, Belfast, United Kingdom
| | - J. Graham McGeown
- Centre for Experimental Medicine, The Queen’s University of Belfast, Belfast, United Kingdom
| | - Tim M. Curtis
- Centre for Experimental Medicine, The Queen’s University of Belfast, Belfast, United Kingdom
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Oláh O, Tóth-Szűki V, Temesvári P, Bari F, Domoki F. Delayed neurovascular dysfunction is alleviated by hydrogen in asphyxiated newborn pigs. Neonatology 2013; 104:79-86. [PMID: 23859876 DOI: 10.1159/000348445] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 01/28/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND The neurovascular unit encompasses the functional interactions of cerebrovascular and brain parenchymal cells necessary for the metabolic homeostasis of neurons. Previous studies indicated marked but only transient (1-4 h) reactive oxygen species-dependent neurovascular dysfunction in newborn pigs after severe hypoxic/ischemic (H/I) stress contributing to the neuronal injury after birth asphyxia. OBJECTIVES Our major purpose was to determine if neurovascular dysfunction would also occur later, at 24 h after a milder H/I stress. We also tested if the putative hydroxyl radical scavenger hydrogen (H2) exerted neurovascular protection. METHODS Anesthetized, ventilated piglets were assigned to three groups of 9 animals: time control, asphyxia/reventilation with air, and asphyxia/reventilation with air +2.1% H2 for 4 h. Asphyxia was induced by suspending ventilation for 8 min. Cerebrovascular reactivity (CR) of pial arterioles was determined using closed cranial window/intravital microscopy 24 h after asphyxia to the endothelium-dependent cerebrovascular stimulus hypercapnia, the neuronal function-dependent stimulus N-methyl-D-aspartate (NMDA), norepinephrine, and sodium nitroprusside. The brains were subjected to histopathology. RESULTS Hemodynamic parameters, blood gases, and core temperature did not differ significantly among the experimental groups. In the early reventilation period, the recovery of electroencephalographic activity was significantly better in H2-treated animals. Asphyxia/reventilation severely attenuated CR to hypercapnia and NMDA; however, reactivity to norepinephrine and sodium nitroprusside were unaltered. H2 fully or partially preserved CR to hypercapnia or NMDA, respectively. Histopathology revealed modest neuroprotection afforded by H2. CONCLUSIONS Severe stimulus-selective delayed neurovascular dysfunction develops and persists even after mild H/I stress. H2 alleviates this delayed neurovascular dysfunction that can contribute to its neuroprotective effect.
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Affiliation(s)
- Orsolya Oláh
- Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary. olah.orsolya @ med.u-szeged.hu
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