1
|
Perpetuini D, Filippini C, Zito M, Cardone D, Merla A. Altered Microcirculation in Alzheimer’s Disease Assessed by Machine Learning Applied to Functional Thermal Imaging Data. Bioengineering (Basel) 2022; 9:bioengineering9100492. [PMID: 36290459 PMCID: PMC9598647 DOI: 10.3390/bioengineering9100492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/12/2022] [Accepted: 09/16/2022] [Indexed: 11/24/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by progressive memory failures accompanied by microcirculation alterations. Particularly, impaired endothelial microvascular responsiveness and altered flow motion patterns have been observed in AD patients. Of note, the endothelium influences the vascular tone and also the small superficial blood vessels, which can be evaluated through infrared thermography (IRT). The advantage of IRT with respect to other techniques relies on its contactless features and its capability to preserve spatial information of the peripheral microcirculation. The aim of the study is to investigate peripheral microcirculation impairments in AD patients with respect to age-matched healthy controls (HCs) at resting state, through IRT and machine learning (ML) approaches. Particularly, several classifiers were tested, employing as regressors the power of the nose tip temperature time course in different physiological frequency bands. Among the ML classifiers tested, the Decision Tree Classifier (DTC) delivered the best cross-validated accuracy (accuracy = 82%) when discriminating between AD and HCs. The results further demonstrate the alteration of microvascular patterns in AD in the early stages of the pathology, and the capability of IRT to assess vascular impairments. These findings could be exploited in clinical practice, fostering the employment of IRT as a support for the early diagnosis of AD.
Collapse
Affiliation(s)
- David Perpetuini
- Department of Neuroscience and Imaging, University “G. D’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy
- Correspondence: ; Tel.: +39-0871-3556954
| | - Chiara Filippini
- Department of Neuroscience and Imaging, University “G. D’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy
| | - Michele Zito
- Department of Medicine and Science of Ageing, University “G. D’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy
| | - Daniela Cardone
- Department of Engineering and Geology, University “G. D’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy
| | - Arcangelo Merla
- Department of Engineering and Geology, University “G. D’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy
- Next2U s.r.l., 65127 Pescara, Italy
| |
Collapse
|
2
|
Abstract
Potassium homeostasis affects cardiac rhythm and contractility, along with vascular reactivity and vascular smooth muscle proliferation. This chapter will focus on potassium dynamics during and after cardiac surgery involving cardioplegic arrest and cardiopulmonary bypass (CPB). Hyperkalemic, hypothermic solutions are frequently used to induce cardioplegic arrest and protect the heart during cardiac surgery involving CPB. Common consequences of hyperkalemic cardioplegic arrest and reperfusion include microvascular dysfunction involving several organ systems and myocardial dysfunction. Immediately after CPB, blood potassium levels often drop precipitously due to a variety of factors, including CPB -induced electrolyte depletion and frequent, long-term administration of insulin during and after surgery. Meanwhile, some patients with pre-existing kidney dysfunction may experience postoperative hyperkalemia following cardioplegia. Any degree of postoperative hyper/hypokalemia significantly elevates the risk of cardiac arrythmias and subsequent myocardial failure. Therefore, proper management of blood potassium levels during and after cardioplegia/CPB is crucial for optimizing patient outcomes following cardiac surgery.
Collapse
|
3
|
Jiang HL, Kim YK, Cho KH, Jang YC, Choi YJ, Chung JH, Cho CS. Roles of spheroid formation of hepatocytes in liver tissue engineering. Int J Stem Cells 2014; 3:69-73. [PMID: 24855543 DOI: 10.15283/ijsc.2010.3.2.69] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2010] [Indexed: 01/15/2023] Open
Abstract
The liver plays an important role in a broad spectrum of physiological functions and detoxifies endogenous and exogenous substances. The liver failure is associated with a high risk of mortality because it is one of important organs in our body. Various bioartificial liver (BAL) systems have been used for clinical trials as a bridge for liver transplantations in patients with liver failure. Long term and stable liver-specific functions of hepatocytes in the development of BAL support systems should be considered. Spheroid formation of hepatocytes enhances liver-specific functions. In this review, hepatocyte spheroid formation methods such as galactose density, topology of extracellular matrix, micro-molding technique, hanging-drop culture, non-adhesive surface, positive charged surface, spinner culture, rocked technique, medium component, external forces, coculture system and polymeric nanospheres are explained for enhancing liver-specific functions.
Collapse
Affiliation(s)
- Hu-Lin Jiang
- College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - You-Kyoung Kim
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| | - Ki-Hyun Cho
- Department of Plastic and Reconstructive Surgery, Hangang Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Young-Chul Jang
- Department of Plastic and Reconstructive Surgery, Hangang Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Yun-Jaie Choi
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| | - Jong-Hoon Chung
- Department of Biosystem Engineering and Biomaterial Sciences, Seoul National University, Seoul, Korea
| | - Chong-Su Cho
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| |
Collapse
|
4
|
Dobson GP, Faggian G, Onorati F, Vinten-Johansen J. Hyperkalemic cardioplegia for adult and pediatric surgery: end of an era? Front Physiol 2013; 4:228. [PMID: 24009586 PMCID: PMC3755226 DOI: 10.3389/fphys.2013.00228] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 08/05/2013] [Indexed: 12/16/2022] Open
Abstract
Despite surgical proficiency and innovation driving low mortality rates in cardiac surgery, the disease severity, comorbidity rate, and operative procedural difficulty have increased. Today's cardiac surgery patient is older, has a "sicker" heart and often presents with multiple comorbidities; a scenario that was relatively rare 20 years ago. The global challenge has been to find new ways to make surgery safer for the patient and more predictable for the surgeon. A confounding factor that may influence clinical outcome is high K(+) cardioplegia. For over 40 years, potassium depolarization has been linked to transmembrane ionic imbalances, arrhythmias and conduction disturbances, vasoconstriction, coronary spasm, contractile stunning, and low output syndrome. Other than inducing rapid electrochemical arrest, high K(+) cardioplegia offers little or no inherent protection to adult or pediatric patients. This review provides a brief history of high K(+) cardioplegia, five areas of increasing concern with prolonged membrane K(+) depolarization, and the basic science and clinical data underpinning a new normokalemic, "polarizing" cardioplegia comprising adenosine and lidocaine (AL) with magnesium (Mg(2+)) (ALM™). We argue that improved cardioprotection, better outcomes, faster recoveries and lower healthcare costs are achievable and, despite the early predictions from the stent industry and cardiology, the "cath lab" may not be the place where the new wave of high-risk morbid patients are best served.
Collapse
Affiliation(s)
- Geoffrey P. Dobson
- Department of Physiology and Pharmacology, Heart and Trauma Research Laboratory, James Cook UniversityTownsville, QLD, Australia
| | - Giuseppe Faggian
- Division of Cardiac Surgery, University of Verona Medical SchoolVerona, Italy
| | - Francesco Onorati
- Division of Cardiac Surgery, University of Verona Medical SchoolVerona, Italy
| | - Jakob Vinten-Johansen
- Cardiothoracic Research Laboratory of Emory University Hospital Midtown, Carlyle Fraser Heart CenterAtlanta, GA, USA
| |
Collapse
|
5
|
Bonaventura D, de Lima RG, da Silva RS, Bendhack LM. NO donors-relaxation is impaired in aorta from hypertensive rats due to a reduced involvement of K(+) channels and sarcoplasmic reticulum Ca(2+)-ATPase. Life Sci 2011; 89:595-602. [PMID: 21839096 DOI: 10.1016/j.lfs.2011.07.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 07/05/2011] [Accepted: 07/19/2011] [Indexed: 10/17/2022]
Abstract
AIMS To examine the vasodilatation induce by the NO donors, [Ru(terpy)(bdq)NO](3+) (TERPY) and sodium nitroprusside (SNP), and to compare their effects in aortic rings from hypertensive 2K-1C and normotensive 2K rats. MAIN METHODS Vascular reactivity was performed in aortic rings pre-contracted with phenylephrine (Phe 100nM). We have analyzed the maximal relaxation (Emax) and potency (pD(2)) of NO donors. KEY FINDINGS Potency of SNP was greater than TERPY in both arterial groups. The vasodilatation induced by TERPY was greater in 2K than in 2K-1C, and it was inhibited by sGC inhibitor ODQ in 2K and in 2K-1C aortic rings. ODQ did not alter the efficacy to SNP, but it reduced its potency in 2K and 2K-1C. The blockade of K(+) channels reduced the potency of TERPY only in aortic rings of 2K. On the other hand, the potency of SNP was reduced in both 2K and 2K-1C. The combination of ODQ and TEA reduced the relaxation induced by TERPY and SNP in 2K and reduced the efficacy to SNP in 2K-1C aortic rings but it had no additional effect on the TERPY relaxation in 2K-1C aortas. The production of cGMP induced by TERPY was greater than that produced by SNP, which was similarly increased in 2K and 2K-1C. Sarcoplasmic reticulum Ca-ATPase inhibition only impaired the relaxation induced by SNP in 2K aortic rings. SIGNIFICANCE Taken together, our results provide evidences that in this model of hypertension, impaired K(+) channels activation by TERPY and SERCA activation by SNP may contribute to decreased vasodilatation.
Collapse
Affiliation(s)
- Daniella Bonaventura
- Depto. de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Brazil.
| | | | | | | |
Collapse
|
6
|
Vaithianathan T, Narayanan D, Asuncion-Chin MT, Jeyakumar LH, Liu J, Fleischer S, Jaggar JH, Dopico AM. Subtype identification and functional characterization of ryanodine receptors in rat cerebral artery myocytes. Am J Physiol Cell Physiol 2010; 299:C264-78. [PMID: 20445169 PMCID: PMC2928634 DOI: 10.1152/ajpcell.00318.2009] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 05/04/2010] [Indexed: 11/22/2022]
Abstract
Ryanodine receptors (RyRs) regulate contractility in resistance-size cerebral artery smooth muscle, yet their molecular identity, subcellular location, and phenotype in this tissue remain unknown. Following rat resistance-size cerebral artery myocyte sarcoplasmic reticulum (SR) purification and incorporation into POPE-POPS-POPC (5:3:2; wt/wt) bilayers, unitary conductances of 110 +/- 8, 334 +/- 15, and 441 +/- 27 pS in symmetric 300 mM Cs(+) were usually detected. The most frequent (34/40 bilayers) conductance (334 pS) decreased to
Collapse
Affiliation(s)
- Thirumalini Vaithianathan
- Department Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Lee EJ, Chan EWL, Yousaf MN. Spatio-Temporal Control of Cell Coculture Interactions on Surfaces. Chembiochem 2009; 10:1648-53. [DOI: 10.1002/cbic.200900277] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
8
|
Hannachi IE, Yamato M, Okano T. Cell sheet technology and cell patterning for biofabrication. Biofabrication 2009; 1:022002. [DOI: 10.1088/1758-5082/1/2/022002] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
9
|
Kidambi S, Lee I. Primary Neuron/Astrocyte Co-Culture on Polyelectrolyte Multilayer Films: A Template for Studying Astrocyte-Mediated Oxidative Stress in Neurons. ADVANCED FUNCTIONAL MATERIALS 2008; 18:294-301. [PMID: 25400537 PMCID: PMC4229016 DOI: 10.1002/adfm.200601237] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We engineered patterned co-cultures of primary neurons and astrocytes on polyelectrolyte multilayer (PEM) films without the aid of adhesive proteins/ligands to study the oxidative stress mediated by astrocytes on neuronal cells. A number of studies have explored engineering co-culture of neurons and astrocytes predominantly using cell lines rather than primary cells owing to the difficulties involved in attaching primary cells onto synthetic surfaces. To our knowledge this is the first demonstration of patterned co-culture of primary neurons and astrocytes for studying neuronal metabolism. In our study, we used synthetic polymers, namely poly(diallyldimethylammoniumchloride) (PDAC) and sulfonated poly(styrene) (SPS) as the polycation and polyanion, respectively, to build the multilayers. Primary neurons attached and spread preferentially on SPS surfaces, while primary astrocytes attached to both SPS and PDAC surfaces. SPS patterns were formed on PEM surfaces, either by microcontact printing SPS onto PDAC surfaces or vice-versa, to obtain patterns of primary neurons and patterned co-cultures of primary neurons and astrocytes. We further used the patterned co-culture system to study the neuronal response to elevated levels of free fatty acids as compared to the response in separated monoculture by measuring the level of reactive oxygen species (ROS; a widely accepted marker of oxidative stress). The elevation in the ROS levels was observed to occur earlier in the patterned co-culture system than in the separated monoculture system. The results suggest that this technique may provide a useful tool for engineering neuronal co-culture systems, that may more accurately capture neuronal function and metabolism, and thus could be used to obtain valuable insights into neuronal cell function and perhaps even the pathogenesis of neurodegenerative diseases.
Collapse
|
10
|
Kidambi S, Sheng L, Yarmush ML, Toner M, Lee I, Chan C. Patterned co-culture of primary hepatocytes and fibroblasts using polyelectrolyte multilayer templates. Macromol Biosci 2007; 7:344-53. [PMID: 17370273 DOI: 10.1002/mabi.200600205] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This paper describes the formation of patterned cell co-cultures using the layer-by-layer deposition of synthetic ionic polymers and without the aid of adhesive proteins/ligands such as collagen or fibronectin. In this study, we used synthetic polymers, namely poly(diallyldimethylammonium chloride) (PDAC) and sulfonated polystyrene (SPS) as the polycation and polyanion, respectively, to build the multilayer films. We formed SPS patterns on polyelectrolyte multilayer (PEM) surfaces either by microcontact printing PDAC onto SPS surfaces or vice-versa. To create patterned co-cultures on PEMs, we capitalize on the preferential attachment and spreading of primary hepatocytes on SPS as opposed to PDAC surfaces. In contrast, fibroblasts readily attached to both PDAC and SPS surfaces, and as a result, we were able to obtain patterned co-cultures of fibroblast and primary hepatocytes on synthetic PEM surfaces. We characterized the morphology and hepatic-specific functions of the patterned cell co-cultures with microscopy and biochemical assays. Our results suggest an alternative approach to fabricating controlled co-cultures with specified cell-cell and cell-surface interactions; this approach provides flexibility in designing cell-specific surfaces for tissue engineering applications.
Collapse
Affiliation(s)
- Srivatsan Kidambi
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824, USA
| | | | | | | | | | | |
Collapse
|
11
|
Haga JH, Li YSJ, Chien S. Molecular basis of the effects of mechanical stretch on vascular smooth muscle cells. J Biomech 2007; 40:947-60. [PMID: 16867303 DOI: 10.1016/j.jbiomech.2006.04.011] [Citation(s) in RCA: 221] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2005] [Accepted: 04/23/2006] [Indexed: 10/24/2022]
Abstract
The pulsatile nature of blood pressure and flow creates hemodynamic stimuli in the forms of cyclic stretch and shear stress, which exert continuous influences on the constituents of the blood vessel wall. Vascular smooth muscle cells (VSMCs) use multiple sensing mechanisms to detect the mechanical stimulus resulting from pulsatile stretch and transduce it into intracellular signals that lead to modulations of gene expression and cellular functions, e.g., proliferation, apoptosis, migration, and remodeling. The cytoskeleton provides a structural framework for the VSMC to transmit mechanical forces between its luminal, abluminal, and junctional surfaces, as well as its interior, including the focal adhesion sites, the cytoplasm, and the nucleus. VSMCs also respond differently to the surrounding structural environment, e.g., two-dimensional versus three-dimensional matrix. In vitro studies have been conducted on cultured VSMCs on deformable substrates to elucidate the molecular mechanisms by which the cells convert mechanical inputs into biochemical events, eventually leading to functional responses. The knowledge gained from research on mechanotransduction in vitro, in conjunction with verifications under in vivo conditions, will advance our understanding of the physiological and pathological processes involved in vascular remodeling and adaptation in health and disease.
Collapse
Affiliation(s)
- Jason H Haga
- Department of Bioengineering and Medicine, Whitaker Institute of Biomedical Engineering, University of California, San Diego, La Jolla, CA 92093-0412, USA
| | | | | |
Collapse
|
12
|
Zhang Q, Cao C, Mangano M, Zhang Z, Silldorff EP, Lee-Kwon W, Payne K, Pallone TL. Descending vasa recta endothelium is an electrical syncytium. Am J Physiol Regul Integr Comp Physiol 2006; 291:R1688-99. [PMID: 16840652 DOI: 10.1152/ajpregu.00261.2006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined gap junction coupling of descending vasa recta (DVR). DVR endothelial cells or pericytes were depolarized to record the associated capacitance transients. Virtually all endothelia and some pericytes exhibited prolonged transients lasting 10-30 ms. Carbenoxolone (100 microM) and 18beta-glycyrrhetinic acid (18betaGRA; 100 microM) markedly shortened the endothelial transients. Carbenoxolone and heptanol (2 mM) reduced the pericyte capacitance transients when they were prolonged. Lucifer yellow (LY; 2 mM) was dialyzed into the cytoplasm of endothelial cells and pericytes. LY spread diffusely along the endothelial monolayer, whereas in most pericytes, it was confined to a single cell. In some pericytes, complex patterns of LY spreading were observed. DVR cells were depolarized by voltage clamp as fluorescence of bis(1,3-dibarbituric acid)-trimethine oxanol [DiBAC(4)(3)] was monitored approximately 200 microm away. A 40-mV endothelial depolarization was accompanied by a 26.1 +/- 5.5-mV change in DiBAC(4)(3) fluorescence. DiBAC(4)(3) fluorescence did not change after 18betaGRA or when pericytes were depolarized. Similarly, propagated cytoplasmic Ca(2+) responses arising from mechanical perturbation of the DVR wall were attenuated by 18betaGRA or heptanol. Connexin (Cx) immunostaining showed predominant linear Cx40 and Cx43 in endothelia, whereas Cx37 stained smooth muscle actin-positive pericytes. We conclude that the DVR endothelium is an electrical syncytium and that gap junction coupling in DVR pericytes exists but is less pronounced.
Collapse
Affiliation(s)
- Qingli Zhang
- Division of Nephrology N3W143, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD 21201, USA
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Zhang HS, Xiao JH, Cao EH, Qin JF. Homocysteine inhibits store-mediated calcium entry in human endothelial cells: evidence for involvement of membrane potential and actin cytoskeleton. Mol Cell Biochem 2005; 269:37-47. [PMID: 15786715 DOI: 10.1007/s11010-005-3168-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The role of homocysteine for store-operated calcium influx was investigated in human umbilical cord endothelial cell line. Homocysteine significantly decreased thapsigargin-evoked Ca2+ entry, membrane hyperpolarization and actin polymerization. GSH and DTT prevented homocysteine-induced inhibition of thapsigargin-evoked Ca2+ entry, membrane hyperpolarization and actin polymerization; while GSSG had the opposite effect. Homocysteine blocked large conductance Ca2+-activated K+ (BK(Ca)) channels in a concentration-dependent manner and related to the redox status of the endothelial cells. BK(Ca) channels opener NS1619 reversed thapsigargin-evoked Ca2+ entry, membrane hyperpolarization and actin polymerization; BK(Ca) channels inhibitor iberiotoxin had the opposite effect. The findings suggest that homocysteine is involved in store-regulated Ca2+ entry through membrane potential-dependent and actin cytoskeleton-dependent mechanisms, redox status of homocysteine and BK(Ca) channels may play a regulatory role in it.
Collapse
Affiliation(s)
- Hong-Sheng Zhang
- Center for System Biology, Institute of Biophysics, Acadenia Sinica, Chaoyang District, Beijing, PR China
| | | | | | | |
Collapse
|
14
|
Liang W, Buluc M, van Breemen C, Wang X. Vectorial Ca2+ release via ryanodine receptors contributes to Ca2+ extrusion from freshly isolated rabbit aortic endothelial cells. Cell Calcium 2005; 36:431-43. [PMID: 15451626 DOI: 10.1016/j.ceca.2004.04.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2004] [Revised: 04/06/2004] [Accepted: 04/07/2004] [Indexed: 11/19/2022]
Abstract
In this study, we identified ryanodine receptors (RyRs) as a component of a cytosolic Ca(2+) removal pathway in freshly isolated rabbit aortic endothelial cells. In an earlier article, we reported that the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) and Na(+)/Ca(2+) exchanger (NCX) function in series to extrude cytosolic Ca(2+) to the extracellular space. Here we employed caffeine and ryanodine as modulators of RyR and showed that they act as the linkage between SERCA and NCX in removing Ca(2+) from the cytoplasm. Our data indicate that both 15 mM caffeine and 1 microM ryanodine facilitated Ca(2+) extrusion by activating RyRs while 100 microM ryanodine had the opposite effect by blocking RyRs. A further attempt to investigate RyR pharmacology revealed that in the absence of extracellular Ca(2+), ryanodine at 1 microM, but not 100 microM, stimulated Ca(2+) loss from the endoplasmic reticulum (ER). Blockade of RyR had no effect on the Ca(2+) removal rate when NCX had been previously blocked. In addition, the localization of RyR was determined using confocal microscopy of BODIPY TR-X fluorescent staining. Taken together, our findings suggest that in freshly isolated endothelial cells Ca(2+) is removed in part by transport through SERCA, RyR, and eventually NCX, and that RyR and NCX are in close functional proximity near the plasma membrane. After blockade of this component, Ca(2+) extrusion could be further inhibited by carboxyeosin, indicating a parallel contribution by the plasmalemmal Ca(2+)-ATPase (PMCA).
Collapse
Affiliation(s)
- Willmann Liang
- Department of Pharmacology and Therapeutics, The James Hogg iCAPTURE Centre for Cardiovascular and Pulmonary Research, St. Paul's Hospital, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada
| | | | | | | |
Collapse
|
15
|
Abstract
The spatial arrangement of individual cell types can now be routinely controlled using soft-lithography-based micropatterning of complementary cell-adhesive and cell-resistant patterns. However, the application of these tools in tissue engineering to recreate tissue complexity in vitro has been hampered by the challenge of finding noncytotoxic procedures for converting complementary cell-resistant regions that define the arrangement of the first cell type into cell-adhesive regions to allow for the attachment of other cell types. A polyelectrolyte assembly approach is presented here for the first time, which allows for this noncytotoxic conversion and, thus, micropatterning of two different cell types, for example, endothelial cells and fibroblasts, on biodegradable substrates. The flexibility of this approach is further demonstrated by inducing organized capillary formation by endothelial cells on micropatterned lines followed by subsequent assembly of fibroblasts.
Collapse
Affiliation(s)
- Carlos C Co
- Department of Chemical and Materials Engineering, University of Cincinnati, 497 Rhodes Hall, Cincinnati, OH 45221, USA
| | | | | |
Collapse
|
16
|
Li PL, Lee HC, Nelson MT, Meininger GA, Van Breemen C. Novel Ca2+ signalling mechanisms in vascular myocytes: symposium overview. ACTA ACUST UNITED AC 2004; 179:339-52. [PMID: 14656371 DOI: 10.1046/j.0001-6772.2003.01216.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This commentary presents the proceedings of the symposium sponsored by Cardiovascular Section of American Physiological Society in San Diego, CA on 12 April 2003. The major focus of this symposium was on the actions and physiological relevance of several novel Ca2+ signalling mechanisms in vascular smooth muscle (VSM) cells. Five important topics were presented in this symposium including the discovery and roles of cyclic ADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP) in mediating Ca2+ release, Ca2+ sparks and activation of plasma membrane KCa channels in VSM cells, the role of cADPR-mediated activation of ryanodine receptors in the control of vascular tone, the role of [Ca2+]i in mechanotransduction in the arterioles, and interactions of mitochondrial Ca2+ release and SR Ca2+ mobilization. The purpose of this symposium was to promote discussions and exchange of ideas between scientists with interests in Ca2+ signalling mechanisms and those with interests in vascular physiology and pharmacology. The cross-fertilization of ideas is expected to greatly advance our understanding of the physiological and pharmacological relevance of these new Ca2+ signalling mechanisms.
Collapse
Affiliation(s)
- P-L Li
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | | | | | | | | |
Collapse
|
17
|
Jones RD, English KM, Pugh PJ, Morice AH, Jones TH, Channer KS. Pulmonary vasodilatory action of testosterone: evidence of a calcium antagonistic action. J Cardiovasc Pharmacol 2002; 39:814-23. [PMID: 12021575 DOI: 10.1097/00005344-200206000-00006] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Recent evidence supports a beneficial effect of testosterone on the cardiovascular system. Testosterone acts as a coronary vasodilator and reduces myocardial ischemia in men with coronary heart disease. The aim of the current study was to determine whether testosterone has a similar vasodilatory action in the pulmonary circulation and to characterize the underlying mechanism of action. The vasodilatory action of testosterone was studied in pulmonary arteries (n = 132, mean internal diameter = 344 +/- 8 microm) isolated from male rats (n = 48, mass = 396 +/- 7 g) mounted in a small vessel wire myograph and loaded to a tension equivalent to 17.5 mm Hg. Micromolar concentrations of testosterone induced dilatation in pulmonary arteries preconstricted with prostaglandin F2alpha (100 microM) within seconds of application. Dilatation to testosterone was similar in vessels treated with N-gamma-nitro-l-arginine methyl ester (l-NAME) (10 microM) or vehicle (5 microl distilled water), -38.2 +/- 2.9%, and -38.1 +/- 3.4%, respectively, and in vessels treated with indomethacin (10 microM), flutamide (10 microM), or vehicle (5 microl ethanol), -35.5 +/- 2.8%, -43.2 +/- 3.6%, and -35.7 +/- 4.6%, respectively (all p > 0.05). Maximal dilatation to testosterone occurred following preconstriction with agents that activated voltage-gated calcium channels such as prostaglandin F2alpha (-34.6 +/- 5.0%), BAY K8644 (-32.9 +/- 8.7), or potassium chloride (-26.7 +/- 1.5%), compared with calcium-independent protein kinase C activation by phorbol dibutyrate (-14.7 +/- 1.6%) or capacitative calcium entry via thapsigargin (-5.1 +/- 0.9%). This study demonstrates that testosterone induces pulmonary dilatation via a mechanism that is independent of the classic androgen receptor and also of the release of nitric oxide or dilator prostaglandins. The data support a calcium antagonistic action for testosterone in the pulmonary circulation, primarily against voltage-gated calcium channels.
Collapse
Affiliation(s)
- Richard D Jones
- Academic Unit of Endocrinology, Division of Genomic Medicine, The University of Sheffield, UK.
| | | | | | | | | | | |
Collapse
|
18
|
Walia M, Sormaz L, Samson SE, Lee RM, Grover AK. Effects of hydrogen peroxide on pig coronary artery endothelium. Eur J Pharmacol 2000; 400:249-53. [PMID: 10988341 DOI: 10.1016/s0014-2999(00)00393-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peroxides and other reactive oxygen species damage arteries during ischemia-reperfusion. Here, we report on the effects of H(2)O(2) on contractility of pig coronary artery. We either treated 3-mm coronary artery rings with 0 to 0.5 mM H(2)O(2) in organ baths or we perfused the arteries with H(2)O(2) and then cut them into rings. In each instance, we monitored the force of contraction of 3-mm rings in H(2)O(2)-free solution with 30 mM KCl and then we determined the A23187 induced endothelium dependent relaxation as a percent of this contraction. Treatment with H(2)O(2) in the organ bath caused a decrease in the contraction but it did not affect the percent relaxation. Treating arteries with H(2)O(2) by luminal perfusion did not affect the contraction but it decreased the percent relaxation. Perfusion alone decreased the amount of endothelium remaining in the arteries and perfusing with H(2)O(2) decreased it further. The percent relaxation with A23187 correlated well with the endothelium remaining in the arteries. We propose that H(2)O(2) and shear stress can cause a loss of endothelium and that endothelium can also protect the underlying smooth muscle against luminal H(2)O(2).
Collapse
Affiliation(s)
- M Walia
- Department of Medicine, McMaster University, Hamilton, L8N3Z5., Ontario, Canada
| | | | | | | | | |
Collapse
|
19
|
Grover AK, Hui J, Samson SE. Catalase activity in coronary artery endothelium protects smooth muscle against peroxide damage. Eur J Pharmacol 2000; 387:87-91. [PMID: 10633165 DOI: 10.1016/s0014-2999(99)00795-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Cyclopiazonic acid contracts pig coronary artery de-endothelialized rings, and pretreating the rings with hydrogen peroxide (H(2)O(2)) inhibits this contraction (IC(50)=0.097+/-0.013 mM). We used the cyclopiazonic acid contraction to test the novel hypothesis that endothelium can protect underlying smooth muscle against luminal H(2)O(2). We perfused the arteries with Krebs' solution containing 0. 3 or 1 mM H(2)O(2), removing endothelium from the arteries either before or after the perfusion. We then cut rings from them to monitor their contraction to 10 microM cyclopiazonic acid in a H(2)O(2)-free solution. The inhibition of the cyclopiazonic acid contraction by perfusion with H(2)O(2) was significantly less when endothelium was removed after the perfusion than when it was removed before it. The specific activity of catalase in post-nuclear supernatants from freshly isolated endothelium (14.1+/-2.7 micromol/min/mg protein) was 17+/-3-fold greater than in those from smooth muscle (0.83+/-0.22 micromol/min/mg protein). Thus endothelium contained high catalase activity and protected the underlying smooth muscle against luminal peroxide.
Collapse
MESH Headings
- Animals
- Catalase/metabolism
- Coronary Vessels/drug effects
- Coronary Vessels/enzymology
- Coronary Vessels/physiology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/enzymology
- Endothelium, Vascular/physiology
- Enzyme Inhibitors/pharmacology
- Hydrogen Peroxide/toxicity
- In Vitro Techniques
- Indoles/pharmacology
- Muscle Contraction/drug effects
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/physiology
- Oxidants/toxicity
- Perfusion
- Swine
Collapse
Affiliation(s)
- A K Grover
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
| | | | | |
Collapse
|
20
|
Bhatia SN, Balis UJ, Yarmush ML, Toner M. Effect of cell-cell interactions in preservation of cellular phenotype: cocultivation of hepatocytes and nonparenchymal cells. FASEB J 1999; 13:1883-900. [PMID: 10544172 DOI: 10.1096/fasebj.13.14.1883] [Citation(s) in RCA: 732] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Heterotypic cell interaction between parenchymal cells and nonparenchymal neighbors has been reported to modulate cell growth, migration, and/or differentiation. In both the developing and adult liver, cell-cell interactions are imperative for coordinated organ function. In vitro, cocultivation of hepatocytes and nonparenchymal cells has been used to preserve and modulate the hepatocyte phenotype. We summarize previous studies in this area as well as recent advances in microfabrication that have allowed for more precise control over cell-cell interactions through 'cellular patterning' or 'micropatterning'. Although the precise mechanisms by which nonparenchymal cells modulate the hepatocyte phenotype remain unelucidated, some new insights on the modes of cell signaling, the extent of cell-cell interaction, and the ratio of cell populations are noted. Proposed clinical applications of hepatocyte cocultures, typically extracorporeal bioartificial liver support systems, are reviewed in the context of these new findings. Continued advances in microfabrication and cell culture will allow further study of the role of cell communication in physiological and pathophysiological processes as well as in the development of functional tissue constructs for medical applications.
Collapse
Affiliation(s)
- S N Bhatia
- Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
| | | | | | | |
Collapse
|