Effect Of Trehalose On Oxidative Damage And Oligomerization Of α-Synuclein In Mouse Striatum Induced By Manganese

Objective: Manganese(Mn)is one of the many trace elements necessary for the human body.The active group or cofactor formation of many enzymes in the body requires the participation of manganese,and the activator of some enzymes is also manganese.Manganese plays an important role in many metabolic processes in the body,and cell function and regulation and maintenance of the body’s biochemistry are also inseparable from the metal ion of manganese.However,excessive exposure to manganese can also cause manganese poisoning,that is,manganese damages the nervous system,showing symptoms similar to Parkinson’s(PD).In real life,the main source of manganese poisoning is occupational exposure,such as the exposure of smelting and manganese alloy industry.Manganese may also increase the level of manganese in the air due to the application of fuel additives(MMT),which leads to a wider range of non-occupational manganese.Exposed.Manganese homeostasis is essential for maintaining health and preventing neurotoxicity.Therefore,it is important to study the exact molecular mechanism of manganese poisoning.The current research focuses on the following aspects: calcium homeostasis,dopamine(DA)depletion,endoplasmic reticulum stress,mitochondrial dysfunction,and promotion of apoptosis,but the specific mechanism is still unclear.Recent studies have also shown that manganese interferes with the correct folding of neurodegenerative disease-specific proteins including prion proteins,α-Synuclein(α-Syn)and Huntingtin(Htt),This may further lead to the occurrence of neuroinflammation.α-Syn is a 140-amino acid soluble protein that is expressed in the presynaptic and nucleus of the central nervous system.It exists as a monomer under normal conditions and is unfolded.When it encounters external stimuli such as oxidative stress,Metal ions,etc.)can cause oxidative damage to α-Syn and its own oligomerization.The aggregation of α-Syn oligomers is toxic,can inhibit mitochondrial respiration,damage the mitochondrial complex enzyme system and membrane potential,and can cause cells Apoptosis.Trehalose is a non-reducing disaccharide that exists in organisms from bacteria to plants.It has the ability to resist oxidative stress and it also plays a role in neuroprotection,especially in Parkinson’s disease and Huntington’s dance.In animal models of various neurodegenerative diseases,such as neuropathy,recent studies have shown that trehalose is not only a chemical partner of biological macromolecules,but also an autophagy inducer that activates autophagy.In neurodegenerative diseases,the protein’s misfolding is reduced,the structure of the protein is stabilized,and autophagy is activated,thereby enhancing the degradation of proteins with a tendency to aggregate,and finally protecting the neurodegenerative diseases,and autophagy disorders It is also a common feature in many neurodegenerative diseases.We speculate that trehalose may have antioxidative stress,molecular chaperones,and induce m TOR-independent autophagy,so trehalose may affect the oxidative damage and oligomerization of α-Syn induced by manganese.In order to confirm the above speculations,we use experimental animal mice to establish a model of manganese poisoning and observe the effect of trehalose on manganese-induced α-Syn oxidative damage and its oligomerization.The practical significance of this study is not only for manganese poisoning and other heavy metal poisoning.The prevention and treatment provided the corresponding theoretical basis,and also provided a new idea for the treatment of neurodegenerative diseases.Methods: In this study,50 wild-type mice(C57),half male and half female,were divided into 5 groups,10 in each group,male and female cage,and the following experiments were carried out.The first group was the control group,the mice drank the special sterilized water at will;the second group was the manganese stained group,injected with 200μmol/kg Mn Cl2 intraperitoneally,the mice drank the special sterilized water at will;the third group was the trehalose control group,the mice drank the 4%(w/v)trehalose solution prepared by the special sterilized water for mice at will;the fourth group was the intervention group of 2% trehalose,injected with 200μmol/kg intraperitoneally Mn Cl2,mice were randomly drinking 2%(w/v)trehalose solution prepared from special sterilized water for mice;the fifth group was 4% trehalose intervention group,injected with 200μmol/kg Mn Cl2,mice were randomly drinking 4%(w/v)trehalose solution prepared from special sterilized water for mice.The injection volume is 5ml/kg,5 days a week,continuous exposure for 6 weeks,and the body weight of the mice is measured every week.After the experiment,decapitate as soon as possible and quickly craniotomy to take out the complete brain.After peeling the cortex,take Mice striatum,using atomic absorption spectrophotometry to detect manganese content in brain striatum;flow cytometry was used to detect striatum nerve cell apoptosis rate,ROS level,autophagy incidence;using multifunctional microplate reader Detect the levels of SOD and MDA in the striatum and the content of α-Syn sulfhydryl and carbonyl groups;use Western blotting to detect the expression of α-Syn monomers,oligomers and autophagy-related proteins;use transmission electron microscopy to examine the striatum neurons The formation of autophagosomes,etc.Results: Compared with the control group,the manganese content and apoptotic rate in the brain striatum of the 200μmol/kg manganese-stained mice were increased.These results suggest that the mouse subacute manganese exposure model was successfully established;The ROS and MDA in the 200μmol/kg manganese-treated group were increased while the SOD was decreased,but the opposite was found in the 4% trehalose intervention group.The difference was statistically significant.4% trehalose intervention could effectively alleviate 200μmol/kg manganese exposure The increase of α-Syn carbonyl level,the decrease of α-Syn thiol group and the increase of expression of α-Syn monomers and oligomers in the group were statistically significant;Compared with the control group,200μmol/kg staining The amount of autophagic vesicles and the expression of Beclin 1,LC3II/LC3 I protein in manganese group increased,and the expression of p62 protein decreased,the trend was statistically significant.Compared with the 200μmol/kg manganese-treated group,autophagy in the trehalose intervention group The amount of vesicles and the expression of LC3II/LC3 I protein increased,and the expression of Beclin 1 and p62 proteins decreased,and the difference was statistically significant.Conclusion: 1.Trehalose can alleviate the manganese-induced oxidative damage ofα-Syn,thereby alleviating the neurotoxicity of manganese.2.Trehalose alleviates manganese-induced α-Syn oligomerization by up-regulating autophagy,thereby alleviating the neurotoxicity of manganese.