CELASTROL FAMILY HSP90 INHIBITORS IMPROVE MITOCHONDRIAL FUNCTION IN A CARDIAC ISCHEMIA/REPERFUSION IN VITRO MODEL

2020 ◽  
Vol 36 (10) ◽  
pp. S8
Author(s):  
H. Aceros ◽  
K. Khalil ◽  
M. Borie ◽  
M. Tanase ◽  
S. Der Sarkissian ◽  
...  
Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Johannes A Pille ◽  
Michele M Salzman ◽  
Anna A Sonju ◽  
Felicia P Lotze ◽  
Josephine E Hees ◽  
...  

Introduction: In a pig model of myocardial infarction (MI), intracoronary delivered Poloxamer (P) 188 significantly reduces ischemia/reperfusion (IR) injury when given immediately upon reperfusion, with improved mitochondrial function as a predominant effect. As mitochondria are heavily damaged during IR, a direct effect of P188 on mitochondria may lead to better therapy options during reperfusion. To show not only a similar reduction of IR injury by P188 in the brain, but also a direct P188 effect on mitochondria, we established an in-vitro model of IR that consists of damaging isolated rat brain mitochondria with hydrogen peroxide (H 2 O 2 ), one component of ischemia, then applying P188, and analyzing mitochondrial function. Methods: Male Sprague-Dawley rat brains were removed, and the mitochondria isolated by differential centrifugation and Percoll gradients, then kept on ice to slow their bioenergetics prior to any experimental treatments. Mitochondria were exposed to 200 μM H 2 O 2 for 10 min at room temperature with slight agitation; controls received no H 2 O 2 . Samples were then diluted ½ with buffer ± P188 (250 μM after dilution) to simulate reperfusion and treatment, and kept at room temperature for 10 further minutes. ATP synthesis was measured in a luminometer using a luciferase enzymatic assay. Oxygen consumption was measured by closed cell respirometry with an oxygen meter. In both assays, Complex I and Complex II were examined; Complex I substrates glutamate and malate, Complex II substrate succinate plus the Complex I inhibitor rotenone. Statistics: Data are expressed as mean ± SEM. One-Way ANOVA, SNK-Test; Kruskal-Wallis-Test; α=0.05, * vs control. Results: In both Complex I and II, mitochondrial function was significantly impaired by H 2 O 2 , with ATP synthesis affected more at Complex I and oxygen consumption affected more at Complex II. Addition of P188 did not provide any significant improvement in mitochondrial function. Conclusions: Although P188 significantly reduced IR injury when given during reperfusion in a pig model of MI, it does not appear to provide direct protection to mitochondria in this in-vitro model. Whether the exposure to H 2 O 2 causes the appropriate injury for P188 to become effective remains to be elucidated.


2011 ◽  
Vol 165 (2) ◽  
pp. 281-282
Author(s):  
B.J. DuBray ◽  
K.D. Conzen ◽  
G.A. Upadhya ◽  
P. Balachandran ◽  
J. Jia ◽  
...  

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
O Horvath ◽  
L Deres ◽  
K Ordog ◽  
K Bruszt ◽  
B Sumegi ◽  
...  

Abstract Introduction The deterioration of mitochondrial quality control greatly contributes to the hypertension induced cardiac remodeling and progression of heart failure. Our previous in vitro results demonstrated the mitochondrial protective effect of antioxidant BGP-15 compound in the presence of cellular stress. Purpose In our recent study we investigated the effect of BGP-15 on cardiac remodeling in spontaneously hypertensive rats (SHR) with manifested heart failure and on mitochondrial dynamics and function in cell culture model. Methods 15-month-old male SHR received 25 mg/kg/day BGP-15 (SHR-B) or placebo (SHR-C) for 18 weeks. Age matched Wistar rats (WKY) were used as normotensive control. The heart function was monitored by echocardiography. Histological preparations were made from cardiac tissue. Neonatal rat cardiomyocytes (NRCMs) were used as in vitro model. 150 μM H2O2 stress and 50 μM BGP-15 treatment was applied. Mitochondrial network was stained with MitoTracker Red. Mitochondrial membrane potential was detected using JC-1 dye, while mitochondrial function was monitored by the Agilent Seahorse XFp, Cell Mito Stress Test. In both model the cellular levels of mitochondrial dynamics proteins were measured in Western blot. To study the ultrastructure we used electron microscopy in our in vivo and in vitro model. Results Left ventricular (LV) mass and LV wall thickness were increased significantly in SHR-C group compared to the initial values (p<0.05). These parameters were decreased considerably in the SHR-B group. Ejection fraction (EF%) decreased in both SHR group although this downturn was minimal because of the treatment. Chronic high blood pressure caused higher collagen deposition in SHR-C rats that was significantly diminished in the SHR-B group. Regarding the mitochondrial function decrease in the levels of fusion proteins OPA1 and MFN2 was observed in the SHR-C group. These differences were significantly reduced by BGP-15 treatment (p<0.05). Mitigation of the level of fission protein DRP1 was however reduced by BGP-15 (p<0.05). In our cellular model, we observed that the H2O2-induced mitochondrial fragmentation was decreased by BGP-15 treatment (p<0.05). BGP-15 treatment prevented mitochondrial membrane potential fall in H2O2 stress (p<0.05). There was no significant difference in basal respiration among groups by monitoring the mitochondrial function. The maximal respiration capacity and ATP production were significantly higher in the BGP-15 treated group in comparison to the stressed group (p<0.05). Conclusion BGP-15 treatment has beneficial effects on mitochondrial dynamics and structure by promoting fusion processes. It also supports the maintenance of mitochondrial function through the preservation of the mitochondrial structure. The mitigation of remodeling processes and the preserved EF in the treated group are results at least partly of the comprehensible effects of BGP-15 on mitochondrial structure and function. Acknowledgement/Funding GINOP-2.3.2-15-2016-00049; GINOP-2.3.2-15-2016-00048; GINOP-2.3.3-15-2016-00025


2003 ◽  
Vol 69 (4) ◽  
pp. 2087-2093 ◽  
Author(s):  
S. R. Bailey ◽  
M.-L. Baillon ◽  
A. N. Rycroft ◽  
P. A. Harris ◽  
J. Elliott

ABSTRACT Acute laminitis has been associated with the overgrowth of gram-positive bacteria within the equine hindgut, causing the release of factor(s) leading to ischemia-reperfusion of the digits. The products of fermentation which trigger acute laminitis are, as yet, unknown; however, vasoactive amines are possible candidates. The objectives of this study were to use an in vitro model of carbohydrate overload to study the change in populations of cecal streptococci and lactobacilli and to establish whether certain species of these bacteria were capable of producing vasoactive amines from amino acids. Cecal contents from 10 horses were divided into aliquots and incubated anaerobically with either corn starch or inulin (fructan; both at 1 g/100 ml). Samples were taken at 6-h intervals over a 24-h period for enumeration of streptococci, lactobacilli, and gram-negative anaerobes by a dilution method onto standard selective growth media. The effects of the antibiotic virginiamycin (1 mg/100 ml) and calcium hydrogen phosphate (CaHPO4; 0.3 g/100 ml) were also examined. Fermentation of excess carbohydrate was associated with increases in numbers of streptococci and lactobacilli (2- to 3.5-log unit increases; inhibited by virginiamycin) but numbers of gram-negative anaerobes were not significantly affected. A screening agar technique followed by 16S rRNA gene sequence analysis enabled the identification of 26 different bacterial strains capable of producing one or more vasoactive amines. These included members of the species Streptococcus bovis and five different Lactobacillus spp. These data suggest that certain bacteria, whose overgrowth is associated with carbohydrate fermentation, are capable of producing vasoactive amines which may play a role in the pathogenesis of acute laminitis.


Sign in / Sign up

Export Citation Format

Share Document