Pain and Myocardial Ischemia: the Role of Sympathetic Activation

Author(s):  
V. Thämer ◽  
A. Deussen ◽  
J. D. Schipke ◽  
T. Tölle ◽  
Gerd Heusch
2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
W Zuo ◽  
R Tian ◽  
Q Chen ◽  
L Wang ◽  
Q Gu ◽  
...  

Abstract Background Myocardial ischemia-reperfusion injury (MIRI) is one of the leading causes of human death. Nod-like receptor protein-3 (NLRP3) inflammasome signaling pathway involved in the pathogenesis of MIRI. However, the upstream regulating mechanisms of NLRP3 at molecular level remains unknown. Purpose This study investigated the role of microRNA330-5p (miR-330-5p) in NLRP3 inflammasome-mediated MIRI and the associated mechanism. Methods Mice underwent 45 min occlusion of the left anterior descending coronary artery followed by different times of reperfusion. Myocardial miR-330-5p expression was examined by quantitative polymerase chain reaction (PCR), and miR-330-5p antagomir and agomir were used to regulate miR-330-5p expression. To evaluate the role of miR-330-5p in MIRI, Evans Blue (EB)/2, 3, 5-triphenyltetrazolium chloride (TTC) staining, echocardiography, and immunoblotting were used to assess infarct volume, cardiac function, and NLRP3 inflammasome activation, respectively. Further, in vitro myocardial ischemia-reperfusion model was established in cardiomyocytes (H9C2 cell line). A luciferase binding assay was used to examine whether miR-330-5p directly bound to T-cell immunoglobulin domain and mucin domain-containing molecule-3 (TIM3). Finally, the role of miR-330-5p/TIM3 axis in regulating apoptosis and NLRP3 inflammasome formation were evaluated using flow cytometry assay and immunofluorescence staining. Results Compared to the model group, inhibiting miR-330-5p significantly aggravated MIRI resulting in increased infarct volume (58.09±6.39% vs. 37.82±8.86%, P<0.01) and more severe cardiac dysfunction (left ventricular ejection fraction [LVEF] 12.77%±6.07% vs. 27.44%±4.47%, P<0.01; left ventricular end-diastolic volume [LVEDV] 147.18±25.82 vs. 101.31±33.20, P<0.05; left ventricular end-systolic volume [LVESV] 129.11±30.17 vs. 74.29±28.54, P<0.05). Moreover, inhibiting miR-330-5p significantly increased the levels of NLRP3 inflammasome related proteins including caspase-1 (0.80±0.083 vs. 0.60±0.062, P<0.05), interleukin (IL)-1β (0.87±0.053 vs. 0.79±0.083, P<0.05), IL-18 (0.52±0.063 vs. 0.49±0.098, P<0.05) and tissue necrosis factor (TNF)-α (1.47±0.17 vs. 1.03±0.11, P<0.05). Furthermore, TIM3 was confirmed as a potential target of miR-330-5p. As predicted, suppression of TIM3 by small interfering RNA (siRNA) ameliorated the anti-miR-330-5p-mediated apoptosis of cardiomyocytes and activation of NLRP3 inflammasome signaling pathway (Figure 1). Conclusion Overall, our study indicated that miR-330-5p/TIM3 axis involved in the regulating mechanism of NLRP3 inflammasome-mediated myocardial ischemia-reperfusion injury. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): National Natural Science Foundation of China Grants


2011 ◽  
Vol 300 (5) ◽  
pp. H1781-H1787 ◽  
Author(s):  
Sachin S. Kandlikar ◽  
Gregory D. Fink

Excess sympathetic nervous system activity (SNA) is linked to human essential and experimental hypertension. To test whether sympathetic activation is associated with a model of deoxycorticosterone acetate (DOCA)-salt hypertension featuring two kidneys and a moderate elevation of blood pressure, we measured whole body norepinephrine (NE) spillover as an index of global SNA. Studies were conducted in chronically catheterized male Sprague-Dawley rats drinking water containing 1% NaCl and 0.2% KCl. After a 7-day surgical recovery and a 3-day control period, a DOCA pellet (50 mg/kg) was implanted subcutaneously in one group of rats (DOCA), while the other group underwent sham implantation (Sham). NE spillover was measured on control day 2 and days 7 and 14 after DOCA administration or sham implantation. During the control period, mean arterial pressure (MAP) was similar in Sham and DOCA rats. MAP was significantly increased in the DOCA group compared with the Sham group after DOCA administration ( day 14: Sham = 109 ± 5.3, DOCA = 128 ± 3.6 mmHg). However, plasma NE concentration, clearance, and spillover were not different in the two groups at any time. To determine whether selective sympathetic activation to the kidneys contributes to hypertension development, additional studies were performed in renal denervated (RDX) and sham-denervated (Sham-DX) rats. MAP, measured by radiotelemetry, was similar in both groups during the control and DOCA treatment periods. In conclusion, global SNA is not increased during the development of mild DOCA-salt hypertension, and fully intact renal nerves are not essential for hypertension development in this model.


1985 ◽  
Vol 7 ◽  
pp. S13-S18 ◽  
Author(s):  
Gerd Heusch ◽  
Andreas Deussen ◽  
Jochen Schipke ◽  
Holger Vogelsang ◽  
Vera Hoffmann ◽  
...  

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