Related Experiment Video
Updated: May 16, 2025
Use of Animal Model of Sepsis to Evaluate Novel Herbal Therapies
Published on: April 11, 2012
GTS-21 alleviates sepsis-induced atrial fibrillation susceptibility by modulating macrophage polarization and
Jiabao Zhou1, Keke Wu1, Yingxu Ma1
1Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, PR China; Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, Hunan 410011, PR China; Cardiovascular Disease Research Center of Hunan Province, Changsha, Hunan 410011, PR China; Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, Hunan 410011, PR China.
Objective:
Sepsis-induced atrial fibrillation (AF) is driven by systemic inflammation and macrophage-mediated atrial remodeling, with proinflammatory M1 macrophages playing a key role. This study investigates whether GTS-21, an α7nAChR agonist, can reduce AF susceptibility by promoting macrophage polarization towards the anti-inflammatory M2 phenotype.
Methods:
A mouse model of lipopolysaccharide (LPS) (10 mg/kg)-induced sepsis was used to explore the relationship between atrial inflammation and AF. GTS-21 (20 mg/kg) was administered to assess its impact on 48-h survival and AF incidence. Cardiac function was evaluated using echocardiography. Markers of myocardial injury, including CK-MB, LDH, and cTnI, were measured. Macrophage polarization and atrial inflammation were assessed using immunofluorescence, flow cytometry, RT-qPCR, and western blotting. Oxidative stress and mitochondrial function were evaluated using reactive oxygen species (ROS) measurements, electron microscopy, and mitochondrial protein expression analysis. Calcium dynamics were studied using western blotting and confocal microscopy.
Results:
In LPS-induced septic mice, GTS-21 improved 48-h survival rates and reduced the induction rate and duration of AF (P < 0.05). Echocardiography showed a preserved left ventricular ejection fraction and enhanced diastolic function. Mechanistically, it promoted M2 macrophage polarization, inhibited the NF-κB P65/NLRP3/C-caspase 1 pathway to reduce IL-1β release, and alleviated oxidative stress. Additionally, mitochondrial structure was restored by reversing fission and promoting fusion, while calcium-handling proteins (NCX-1, RYR2, and SERCA2a) were regulated to prevent intracellular calcium overload, reducing AF susceptibility.
Conclusion:
GTS-21 mitigated atrial inflammation and reduced the incidence of AF in mice with sepsis by regulating macrophage polarization, reducing oxidative stress, and preserving mitochondrial and calcium dynamics in cardiomyocytes. These findings highlight the therapeutic potential of GTS-21 in treating sepsis-induced AF.
