Decreased Amino Acid Transporter LAT2 Is the Main Determinant of Impaired Protein Utilization During Aging  

作　　者：Rui Song Guang Li Liang Zhao Lili Qiu Xiyu Qin Xiaoxu Zhang Xiaoxue Liu Jun Zhou Mengxiao Hu Liwei Zhang Jiaqi Su Xinjuan Liu Xiaoyu Wang 

机构地区：[1]Department of Nutrition and Health,China Agricultural University,Beijing 100083,China [2]Department of Gastroenterology,Beijing Chao-yang Hospital,Capital Medical University,Beijing 100069,China [3]Department of Health Sciences and Technology,ETH Zurich,Zürich CH-8092,Switzerland

出　　处：《Engineering》2024年第11期88-98,共11页工程（英文）

基　　金：funded by the National Key Research and Development Program of China(2023YFF1104502);the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2022QNRC001).

摘　　要：As the global demographic shifts toward an aging population,understanding the efficiency of protein uti-lization in older adults becomes crucial.Our study explores the intricate relationship between protein intake and aging,with a focus on precision nutrition for older people.Through a meta-analysis,we con-firm a decline in protein-utilization capacity in older individuals and examine the different contributions of plant and animal protein.In experiments involving mice of different ages,older mice exhibited decreases in the biological utilization of four proteins(casein,beef protein,soy protein,and gluten),par-ticularly casein.In subsequent research,casein was studied as a key protein.A decline in gastric digestion function was observed through peptidomics and the examination of pepsin levels using casein.Nevertheless,this decline did not significantly affect the overall protein digestion during the aging pro-cess.The combined application of targeted amino acid metabolomics identified abnormal absorption of amino acids as the underlying cause of decreased protein utilization during aging,particularly emphasiz-ing a reduction in branched-chain amino acids(BCAAs)in older mice.Delving deeper into the proteomics of the intestinal protein digestion and absorption pathway,a reduction of over 60%in large neutral amino acid transporter 2(LAT2)protein expression was observed in both older humans and aged mice.The reduction in LAT2 protein was found to be a key factor influencing the diminished BCAA availability.Overall,our study establishes the significance of amino acid absorption through LAT2 in protein utiliza-tion during aging and offers a new theoretical foundation for improving protein utilization in the older adults.

关 键 词：AGING Protein utilization PEPTIDE Amino acid Large neutral amino acid transporter 2 

分 类 号：R339.38[医药卫生—人体生理学]