Inhibitory Effect Of NAC On Cadmium-caused Toxic Damage And Abnormal Immune Function In Chicken Peritoneal Macrophages

Cadmium(Cd)is a heavy metal that can harm human and animal health.The accumulation of cadmium in the body can cause damage to immune cells.N-Acetyl-L-cysteine(NAC)is a potential heavy metal poisoning inhibitor and inflammatory regulator,which can antagonize the cytotoxicity caused by heavy metals and play an active role in disease treatment and immune regulation.Chicken peritoneal macrophages are an important part of the immune system of chickens.They play a role in antigen presentation and immune response in the occurrence and treatment of chicken diseases.At present,there are few researches on the effect of cadmium and its prevention and treatment on chicken peritoneal macrophages.Therefore,this study established two cell models of cadmium-induced and NAC plus cadmium-induced damage to chicken peritoneal macrophages in order to explore the effect of cadmium on chicken peritoneal macrophages toxicity and the effect of cadmium on immune function,as well as the regulatory effect and mechanism of NAC on the damage of chicken peritoneal macrophages caused by cadmium.In this experiment,Isa brown male laying hens were used as the research object.We isolated,purified and identified peritoneal macrophages,and then added different concentrations of Cd Cl2(20 or 50 μmol·L-1)to the peritoneal macrophages to establish the cadmium-induced damage model,by observing the morphological changes of chicken peritoneal macrophages,detecting the rate of apoptosis,ROS production,mitochondrial membrane potential level and intracellular cadmium accumulation content.It can detect cadmium-damage to macrophages.It can detect the phagocytic activity of macrophages and the expression of pro-inflammatory cytokines(IL-1β,IL-6 and TNF-α)to evaluate the effect of cadmium on the immune function of macrophages.In addition,this experiment explored the regulatory effect and possible mechanism of NAC on the toxic damage and abnormal immunity of cadmium-infected macrophages by pre-adding 500 μmol·L-1 NAC to cadmium-infected macrophages.The results showed:(1)Cadmium can cause time-concentration-related toxic damage to chicken peritoneal macrophages and HD-11 cells.Cadmium-infected chicken peritoneal macrophages showed obvious morphological shrinkage,reduced pseudopodia,and ultrastructural disorders.And it can increase apoptosis rate(P<0.05),excessive production of cellular ROS(P<0.05),and mitochondria membrane potential dropped significantly(P<0.05).(2)Cadmium-infected significantly inhibited the phagocytic activity of chicken peritoneal macrophages(P<0.05),and promoted the expression of pro-inflammatory cytokine genes such as IL-1β,IL-6 and TNF-α in inactivated macrophages and lipopolysaccharide(LPS)activated macrophages(P<0.05).(3)NAC pretreatment can significantly inhibit the accumulation of Cd2+in peritoneal macrophages of cadmium-infected chickens,and reduce the apoptosis,ROS accumulation and mitochondrial damage of chicken peritoneal macrophages caused by cadmium-infected(P<0.05).(4)NAC pretreatment can significantly increase the phagocytic activity of peritoneal macrophages in cadmium-infected chickens(P<0.05),and inhibit the expression of pro-inflammatory cytokine genes such as IL-1β,IL-6 and TNF-α in inactivated macrophages and lipopolysaccharide(LPS)activated macrophages.(P<0.05).In conclusion,Cadmium can cause time-concentration-related toxic damage to chicken peritoneal macrophages and inhibit the immune response of macrophages.Inhibitory effect of NAC on Cadmium-caused toxic damage and abnormal immune function in chicken peritoneal macrophages.This conclusion may be related to its inhibition of cadmium-induced overproduction of ROS,pro-inflammatory response and Cd2+ accumulation in macrophages.It can provide a theoretical basis for the prevention and drug treatment of poultry cadmium poisoning.