| With the continuous expansion of the aging population,the huge aging population will cause many economic,medical and family problems,which will have a serious impact on the entire economic and social development.Aging is an inevitable law of the life process,and aging-related diseases along with the aging process have become a major problem in the current society.Sarcopenia is a disease caused by pathological degenerative changes in muscles during aging.It is one of the common diseases in the elderly.The incidence rate is gradually increasing with age.Nutrition intervention,especially protein nutrition enhancement,is one of the important measures to prevent and treat senile sarcopenia.Based on the establishment of an aging animal model of sarcopenia,this study carried out nutritional interventions on experimental animals with sarcopenia through different types of animal and plant single proteins and their mixed proteins,and detected and analyzed various physiological and biochemical indicators related to sarcopenia.The effect of protein nutrition on the efficacy of sarcopenia intervention and the ability to repair muscle wasting damage,and further explored the effect of protein nutrition intervention on skeletal muscle cell proliferation and differentiation,apoptosis,autophagy,and protein degradation signal pathway related gene expression regulation.The mechanism of skeletal muscle growth,maintaining and slowing down the course of sarcopenia.At the same time,it has clarified the differences in the efficacy of different protein nutrition interventions in reducing and treating sarcopenia;explored the rational protein model of protein nutrition intervention to improve sarcopenia and the internal mechanism of protein nutrition support.The main findings are as follows:(1)A 13-month-old C57BL/6 naturally aging mouse was used to establish a sarcopenia model.Through identification of the weight,muscle weight,muscle strength,muscle function,blood indicators,and gene expression of the aging mice,it was determined that the established animal model conforms to the The criteria for sarcopenia.The results showed that there was a significant difference in body weight between the elderly group and the young group(p=0.015),and there was a very significant difference in the ratio of quadriceps to body weight between the two groups(p=0.004);the grip strength of the old and young rats(p= 0.012).There is a significant difference in motor function(the number of times the spindle fatigue meter falls)(p=0.002);the blood test results show that the amount of hemoglobin(HGB),hematocrit(HCT)and the number of red blood cells in old and young rats are extremely different Significant(p<0.01);blood biochemistry and ELISA results show that compared with young mice,the superoxide dismutase(SOD),glutathione peroxidase(GPX)and lipid peroxidation products(MDA)There are significant differences in levels(p<0.05);the levels of serum total protein(TP)and serum albumin(ALB)in old mice are extremely significantly lower than those in young mice(p=0.007;p=0.003),while aspartate aminotransferase(AST)is extremely significant It is higher than that of young mice(p=0.002);the level of inflammatory factors in old mice is extremely significantly higher than that of young mice(IL-6,IL-10,TNF-α: p<0.01;TGF-β: p<0.001);gene expression Circumstances,the expression of the genes Atrogin-1(p=0.001),IGF-1(p=0.001),GDF-8(p=0.007),and PAX7(p=0.001)related to sarcopenia were extremely high between the two groups.Significant difference,protein degradation regulation gene Mu RF-1,Myo D performance is extremely significant difference(p<0.001).In summary,all levels of indicators such as muscle mass,muscle power,muscle strength,physiology and biochemistry,and gene expression indicate that the animal model established in this study meets the criteria for judging sarcopenia of aging and can be used in this nutritional intervention study.(2)Protein nutrition intervention experiment,the experimental animals were divided into 4 groups,and they were given milk protein,soy protein,and double protein(milk protein: soy protein nitrogen content = 1:1)for 8 weeks of nutrition intervention experiment,and set physiological Saline control group.After protein intervention,measure muscle mass,muscle strength,muscle power,body redox state and inflammatory reaction levels,plasma biochemical indicators,and muscle tissue production and cell proliferation and differentiation.Apoptosis,autophagy,protein synthesis and degradation-related gene expression regulation changes,to explore the effect evaluation and difference of protein nutrition intervention on senile sarcopenia nutrition intervention,and the internal mechanism of protein intervention to improve sarcopenia.The results showed that there was no significant difference in body ratio between the intervention group and the control group before and after the nutrition intervention(p>0.05),indicating that the protein nutrition intervention had no effect on the weight of the mice;after four weeks of nutrition intervention,there were extremely significant differences in grip strength among the four groups(p=0.008),indicating that protein intake has a positive effect on the muscle function of sarcopenia within a certain period of time.The blood test results showed that compared with the control group,after protein intervention,lymphocytes(LYM),monocytes(MON),platelets(PLT),platelet packed volume(PCT)were reduced,and the risk of infection,chronic disease,and blood disease was reduced Among them,the double protein group has the most significant effect;the results of blood biochemistry and ELISA show that the SOD(p<0.01)and GPX(p<0.001)enzyme activities of the experimental group and the control group are significantly different,and the MDA content of the experimental group is extremely low In the control group(p<0.001),and the experimental group has the best double protein effect,which is significantly different from the whey protein group and the soy protein group,indicating that protein nutrition intervention has a positive regulatory effect on the redox level of elderly rats.The contents of TP,ALB and AST in the experimental group were significantly different from those in the control group(p<0.001),and protein nutrition intervention had a positive effect on liver function.Inflammatory factor indicators showed that inflammatory factors and anti-inflammatory factors were significantly reduced after protein intervention(IL-6,TGF-β,TNF-α:p<0.01;IL-10: p<0.001),indicating that protein nutrition is effective The inflammatory response in the elderly has a down-regulating effect;the histopathological HE staining results show that the number of fat particles in the control group is significantly higher than that in the experimental group,the degree of fat infiltration is higher,the number of nuclei is less,the number of muscle fibers is lower than the other three groups,and the number of incomplete cells is more;Gene expression level QPCR results,genes related to cell synthesis m TOR,PI3 K,Akt,wntl,wnt3 a,the expressions were significantly up-regulated(p<0.001);and cell apoptosis,Autophagy and protein degradation related genes IL-6,P53,Cys C,TNF-α,NF-κB,LC3-I,LC3-II,FOXO1,Mu RF-1,MAFbx were all significantly down-regulated(p<0.001),and the double protein group has the most significant effect.Through this study,a comprehensive evaluation of the effect of protein nutrition intervention on the nutritional improvement of senile sarcopenia,the effectiveness of support and maintenance of skeletal muscle,and the difference in the efficacy of different protein types,and further explained the effect of protein nutrition intervention on senile sarcopenia Play the active mechanism of action,provide scientific diet and nutritional solutions for the prevention and treatment of sarcopenia in the elderly to provide theoretical support. |
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