Nano-selenium Antagonizes Apoptosis Of As Broiler Cardiomyocytes Through ATF6-DR5 Signaling Pathway Soy Sauce Production

Broiler ascites syndrome（AS）is one of the main diseases affecting the development of the broiler breeding industry,which seriously restricts the economic benefits of broiler production in my country.Nano selenium is a special selenium supplement with good properties such as antioxidant and antibacterial and has great development potential in medical applications.In this study,based on the ATF6-DR5signaling pathway,we explored the effect of nano-selenium on the apoptosis of AS broiler myocytes and provided a reference for clinical prevention and treatment of broiler ascites.In this study,nano-selenium was prepared by the ascorbic acid reduction method,chitosan was used to modify the surface of selenium particles,and the prepared chitosan nano-selenium colloidal solution was used for subsequent experiments.200μmol/L hydrogen peroxide was used to replicate the apoptosis model of broiler cardiomyocytes in vitro.The experiment was divided into 4 groups:blank group（Con）,selenium group（1μmol/L Se）,selenium+hydrogen peroxide test group（Se+H₂O₂）,and Hydrogen peroxide building block（H₂O₂）.The effect of nano-selenium on cell viability was determined by the CCK-8 method,the intracellular ROS content was determined to detect the ability of nano-selenium to scavenge reactive oxygen species,and the effect of nano-selenium on hydrogen peroxide-induced apoptosis was detected by flow cytometry.Forty-eight 1-day-old AA broilers were reared in the in vivo experiment.After one week of adaptive feeding,they were randomly divided into 4 groups with 12 chickens in each group,namely the blank group（Con）,saline model group（5 mg/L Y）,and selenium group（1 mg/kg Se）,selenium+salt group（Se+Y）,were fed for 28 d.Serum was taken to measure AST,CK,LDH biochemical indexes and GSH-Px,MDA,SOD,CAT,and T-AOC antioxidant indexes,broiler ventricle was taken to calculate ascites index,part of broiler myocardium tissue was taken for fixation,H.E staining,real-time fluorescence quantitative PCR The m RNA and protein expression levels of CHOP,caspase 3,caspase9,GRP78,caspase12,ATF-6,Bax and Bcl-2 were detected by western blotting.The test results showed that the colloidal solution of chitosan nano-selenium（CS-Se NPs）with an average particle size of 117.3 nm and a concentration of 22.1 mmol/L was prepared by the chemical method,and its Zeta potential was+60.5 m V,and it had good stability.In the in vitro experiments,compared with the H₂O₂ group,the ROS content in the Se+H₂O₂group and the Se group was significantly reduced（P<0.01）.Compared with the H₂O₂ group,the apoptosis rate of the Se+H₂O₂ group was significantly lower（P<0.05）.In the in vivo experiment,compared with the Con group,the RV/TV value of the Y group was extremely significantly higher than that of the Con group（P<0.01）,and the RV/TV value of the Se+Y group was significantly different from that of the Con group（P<0.01）.0.05).Compared with group Y,the contents of AST,CK,and LDH in group Y were significantly higher than those in group Se+Y.Compared with the Y group,the GSH-Px,CAT,and T-AOC of the Se+Y group were significantly increased（P<0.05）.Compared with the Y group,the MDA content of the Se+Y group was significantly decreased（P<0.01）.Compared with the Y group,the m RNA expression levels of ATF-6,Bax,GRP-78,CHOP,caspase3,and caspase9 in the Se+Y group were significantly decreased（P<0.05）,and the m RNA expression level of Bcl-2 was significantly increased（P<0.05）.P<0.05).Compared with the Y group,the protein expressions of ATF-6,GRP-78,CHOP,caspase12,caspase 3,caspase 9,and Bax in the Se+Y group were significantly decreased（P<0.05）,and the protein expression of Bcl-2 was significantly increased（P<0.05）.It can be seen from the test results that nano-selenium（1μmol/L）could scavenge ROS generated by hydrogen peroxide（200μmol/L）-induced oxidative stress in chicken cardiomyocytes,and at the same time alleviate the apoptosis of chicken cardiomyocytes.Nano-selenium can reduce the myocardial injury-related enzyme indexes（AST,CK,LDH）of broiler chickens,relieve myocardial injury,and also activate the antioxidant enzyme system（SOD,GSH-Px,CAT）of heart tissue,reduce MDA,and make the T-AOC ability restored in the heart tissue.Nano-selenium can down-regulate the expression of ATF-6,GRP-78,CHOP,and caspase12 genes and proteins in endoplasmic reticulum stress-related signaling pathways,inhibit the expression of downstream related caspase 3,caspase 9,and Bax genes and proteins,and improve downstream anti-inflammatory effects.Apoptotic Bcl-2 gene and protein expression levels,thereby maintaining endoplasmic reticulum homeostasis and alleviating cardiomyocyte apoptosis.It can be seen that nano-selenium can play a protective effect on damaged myocardium in the model of broiler ascites induced by high sodium saltwater by regulating the ATF6-DR5 signaling pathway.