Phases of decompensation during acute ischemia demonstrated in an ex vivo porcine bladder model

Abstract Increased level of C-reactive protein (CRP) is a risk factor for cardiovascular diseases, including myocardial infarction and hypertension. Here, we analyzed the effects of CRP overexpression on cardiac susceptibility to ischemia/reperfusion (I/R) injury in adult spontaneously hypertensive rats (SHR) expressing human CRP transgene (SHR-CRP). Using an in vivo model of coronary artery occlusion, we found that transgenic expression of CRP predisposed SHR-CRP to repeated and prolonged ventricular tachyarrhythmias. Excessive ischemic arrhythmias in SHR-CRP led to a significant reduction in infarct size (IS) compared with SHR. The proarrhythmic phenotype in SHR-CRP was associated with altered heart and plasma eicosanoids, myocardial composition of fatty acids (FAs) in phospholipids, and autonomic nervous system imbalance before ischemia. To explain unexpected IS-limiting effect in SHR-CRP, we performed metabolomic analysis of plasma before and after ischemia. We also determined cardiac ischemic tolerance in hearts subjected to remote ischemic perconditioning (RIPer) and in hearts ex vivo. Acute ischemia in SHR-CRP markedly increased plasma levels of multiple potent cardioprotective molecules that could reduce IS at reperfusion. RIPer provided IS-limiting effect in SHR that was comparable with myocardial infarction observed in naïve SHR-CRP. In hearts ex vivo, IS did not differ between the strains, suggesting that extra-cardiac factors play a crucial role in protection. Our study shows that transgenic expression of human CRP predisposes SHR-CRP to excess ischemic ventricular tachyarrhythmias associated with a drop of pump function that triggers myocardial salvage against lethal I/R injury likely mediated by protective substances released to blood from hypoxic organs and tissue at reperfusion.

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Potential vascular mechanisms in an ex vivo functional pig bladder model

Neurourology and Urodynamics ◽

10.1002/nau.23710 ◽

2018 ◽

Vol 37 (8) ◽

pp. 2425-2433 ◽

Cited By ~ 2

Author(s):

Uzoma A. Anele ◽

Paul H. Ratz ◽

Andrew F. Colhoun ◽

Sydney Roberts ◽

Ryan Musselman ◽

...

Keyword(s):

Ex Vivo ◽

Bladder Model

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An ex vivo bladder model with detrusor smooth muscle removed to analyse biologically active mediators released from the suburothelium

The Journal of Physiology ◽

10.1113/jp276924 ◽

2018 ◽

Vol 597 (6) ◽

pp. 1467-1485 ◽

Cited By ~ 5

Author(s):

Leonie Durnin ◽

Benjamin Kwok ◽

Priya Kukadia ◽

Roisin McAvera ◽

Robert D. Corrigan ◽

...

Keyword(s):

Smooth Muscle ◽

Ex Vivo ◽

Biologically Active ◽

Detrusor Smooth Muscle ◽

Bladder Model

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A Decentralized (Ex Vivo) Murine Bladder Model with the Detrusor Muscle Removed for Direct Access to the Suburothelium during Bladder Filling

Journal of Visualized Experiments ◽

10.3791/60344 ◽

2019 ◽

Author(s):

Leonie Durnin ◽

Robert D. Corrigan ◽

Kenton M. Sanders ◽

Violeta N. Mutafova-Yambolieva

Keyword(s):

Ex Vivo ◽

Direct Access ◽

Detrusor Muscle ◽

Bladder Filling ◽

Bladder Model

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BOTULINUM TOXIN ATTENUATES SENSORY AFFERENT NERVE FIRING IN AN EX VIVO MOUSE BLADDER MODEL

The Journal of Urology ◽

10.1016/s0022-5347(09)60237-8 ◽

2009 ◽

Vol 181 (4S) ◽

pp. 82-83 ◽

Cited By ~ 1

Author(s):

Valerie M Collins ◽

Christopher R Chapple ◽

Neil G McKay ◽

Donna J Sellers ◽

David Grundy

Keyword(s):

Botulinum Toxin ◽

Ex Vivo ◽

Afferent Nerve ◽

Bladder Model

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Melatonin Prevents Early but Not Delayed Ventricular Fibrillation in the Experimental Porcine Model of Acute Ischemia

International Journal of Molecular Sciences ◽

10.3390/ijms22010328 ◽

2020 ◽

Vol 22 (1) ◽

pp. 328

Author(s):

Alena S. Tsvetkova ◽

Olesya G. Bernikova ◽

Natalya J. Mikhaleva ◽

Darya S. Khramova ◽

Alexey O. Ovechkin ◽

...

Keyword(s):

Myocardial Infarction ◽

Ventricular Fibrillation ◽

Porcine Model ◽

Ex Vivo ◽

Interventricular Septum ◽

Left Ventricular ◽

Acute Ischemia ◽

Dispersion Of Repolarization ◽

Intramyocardial Electrograms ◽

Antiarrhythmic Effects

Antiarrhythmic effects of melatonin have been demonstrated ex vivo and in rodent models, but its action in a clinically relevant large mammalian model remains largely unknown. Objectives of the present study were to evaluate electrophysiological and antiarrhythmic effects of melatonin in a porcine model of acute myocardial infarction. Myocardial ischemia was induced by 40-min coronary occlusion in 25 anesthetized pigs. After ischemia onset, 12 animals received melatonin (4 mg/kg). 48 intramyocardial electrograms were recorded from left ventricular wall and interventricular septum (IVS). In each lead, activation time (AT) and repolarization time (RT) were determined. During ischemia, ATs and dispersion of repolarization (DOR = RTmax − RTmin) increased reaching maximal values by 3–5 and 20–25 min, respectively. Ventricular fibrillation (VF) incidence demonstrated no relations to redox state markers and was associated with increased DOR and delayed ATs (specifically, in an IVS base, an area adjacent to the ischemic zone) (p = 0.031). Melatonin prevented AT increase in the IVS base, (p < 0.001) precluding development of early VF (1–5 min, p = 0.016). VF occurrence in the delayed phase (17–40 min) where DOR was maximal was not modified by melatonin. Thus, melatonin-related enhancement of activation prevented development of early VF in the myocardial infarction model.

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Impaired mitochondrial function in chronically ischemic human heart

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00991.2012 ◽

2013 ◽

Vol 304 (11) ◽

pp. H1407-H1414 ◽

Cited By ~ 18

Author(s):

Nis Stride ◽

Steen Larsen ◽

Martin Hey-Mogensen ◽

Christina N. Hansen ◽

Clara Prats ◽

...

Keyword(s):

Ischemic Preconditioning ◽

Mitochondrial Function ◽

Mitochondrial Respiration ◽

Human Heart ◽

Ex Vivo ◽

Ischemic Myocardium ◽

Acute Ischemia ◽

Ros Production ◽

Respiratory Capacity ◽

Mitochondrial Respiratory

Chronic ischemic heart disease is associated with myocardial hypoperfusion. The resulting hypoxia potentially inflicts damage upon the mitochondria, leading to a compromised energetic state. Furthermore, ischemic damage may cause excessive production of reactive oxygen species (ROS), producing mitochondrial damage, hereby reinforcing a vicious circle. Ischemic preconditioning has been proven protective in acute ischemia, but the subject of chronic ischemic preconditioning has not been explored in humans. We hypothesized that mitochondrial respiratory capacity would be diminished in chronic ischemic regions of human myocardium but that these mitochondria would be more resistant to ex vivo ischemia and, second, that ROS generation would be higher in ischemic myocardium. The aim of this study was to test mitochondrial respiratory capacity during hyperoxia and hypoxia, to investigate ROS production, and finally to assess myocardial antioxidant levels. Mitochondrial respiration in biopsies from ischemic and nonischemic regions from the left ventricle of the same heart was compared in nine human subjects. Maximal oxidative phosphorylation capacity in fresh muscle fibers was lower in ischemic compared with nonischemic myocardium ( P < 0.05), but the degree of coupling (respiratory control ratio) did not differ ( P > 0.05). The presence of ex vivo hypoxia did not reveal any chronic ischemic preconditioning of the ischemic myocardial regions ( P > 0.05). ROS production was higher in ischemic myocardium ( P < 0.05), and the levels of antioxidant protein expression was lower. Diminished mitochondrial respiration capacity and excessive ROS production demonstrate an impaired mitochondrial function in ischemic human heart muscle. No chronic ischemic preconditioning effect was found.

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MP09-15 VALIDATION OF EX-VIVO MURINE BLADDER MODEL TO TEST RHOGDI-BASED BLADDER GENE THERAPIES FOR BENIGN AND MALIGNANT BLADDER PATHOLOGIES

The Journal of Urology ◽

10.1016/j.juro.2018.02.341 ◽

2018 ◽

Vol 199 (4S) ◽

Author(s):

Gregory Joice ◽

James Bell ◽

Justin La Favor ◽

Takahiro Yoshida ◽

Gonzalo Torga ◽

...

Keyword(s):

Ex Vivo ◽

Gene Therapies ◽

Bladder Model

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126 ATTENUATION OF SENSORY AFFERENT NERVE FIRING BY BREFELDIN-A IN AN EX VIVO MOUSE BLADDER MODEL

European Urology Supplements ◽

10.1016/s1569-9056(10)60131-5 ◽

2010 ◽

Vol 9 (2) ◽

pp. 72

Author(s):

V.M. Collins ◽

C.R. Chappie ◽

N.G. Mc Kay ◽

D.J. Sellers ◽

D. Grundy

Keyword(s):

Ex Vivo ◽

Brefeldin A ◽

Afferent Nerve ◽

Bladder Model

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Optimization of the current self-assembled urinary bladder model: Organ-specific stroma and smooth muscle inclusion

Canadian Urological Association Journal ◽

10.5489/cuaj.2953 ◽

2015 ◽

Vol 9 (9-10) ◽

pp. 599 ◽

Cited By ~ 6

Author(s):

Hazem Orabi ◽

Alexandre Rousseau ◽

Véronique Laterreur ◽

Stéphane Bolduc

Keyword(s):

Smooth Muscle ◽

Urinary Bladder ◽

Smooth Muscle Cells ◽

Stromal Cells ◽

Ex Vivo ◽

Muscle Cells ◽

Dermal Fibroblasts ◽

Surgical Reconstruction ◽

Organ Specific ◽

Bladder Model

Introduction: Due to the complications associated with the use of non-native biomaterials and the lack of local tissues, bioengineered tissues are required for surgical reconstruction of complex urinary tract diseases, including those of the urinary bladder. The selfassembly method of matrix formation using autologous stromal cells obviates the need for exogenous biomaterials. We aimed at creating novel ex-vivo multilayer urinary tissue from a single bladder biopsy.Methods: After isolating urothelial, bladder stromal and smooth muscle cells from bladder biopsies, we produced 2 models of urinary equivalents: (1) the original one with dermal fibroblasts and (2) the new one with bladder stromal cells. Dermal fibroblasts and bladder stromal cells were stimulated to form an extracellular matrix, followed by sequential seeding of smooth muscle cells and urothelial cells. Stratification and cellular differentiation were assessed by histology, immunostaining and electron microscopy. Barrier function was checked with the permeability test. Biomechanical properties were assessed with uniaxinal tensile strength, elastic modulus, and failure strain.Results: Both urinary equivalents could be handled easily and did not contract. Stratified epithelium, intact basement membrane, fused matrix, and prominent muscle layer were detected in both urinary equivalents. Bladder stromal cell-based constructs had terminally differentiated urothelium and more elasticity than dermal fibroblasts-based equivalents. Permeation studies showed that both equivalents were comparable to native tissues.Conclusions: Organ-specific stromal cells produced urinary tissues with more terminally differentiated urothelium and better biomechanical characteristics than non-specific stromal cells. Smooth muscle cells could be incorporated into the selfassembled tissues effectively. This multi-layer tissue can be used as a urethral graft or as a bladder model for disease modelling and pharmacotherapeutic testing.

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