Several Tissue And Serum Metabonomics Reveal The Mechanism Of Low Temperature Adaptation In Tree Shrews (Tupaia Belangeri)

To explore the adaptation mechanism of tree shrews to low temperature.In the present paper,the environmental temperature was used as the influence factor to study the influence of the external environmental temperature on the energy metabolism of the Tree shrew.In our study,Tupaia belangeri was selected as the research object.Due to its rapid reproduction rate,small size and easy reproduction,T.belangeri is considered as a new experimental animal model,which is widely used in biomedical and medical research.In this study,tree shrews from Dali(high altitude and low temperature)and Mengla(low altitude and high temperature)were collected and untargeted metabolomics analysis was performed using gas chromatography–mass spectrometer(GS–MS)combined detection technology.The differential metabolites in serum and liver were compared to explore the response of the differential metabolites in serum and liver to the external environment.In addition,this study collected adipose tissue from tree shrews under laboratory cold acclimation conditions and normal temperature control conditions,and used liquid chromatography–mass spectrometer(LC–MS)to conduct untargeted metabolomics analysis.The metabolites of adipose tissue at different temperatures were compared.Finally,how the environmental temperature affects the different tissues and organs of the tree shrew is discussed,so as to further study the low temperature adaptation mechanism of the tree shrew,in order to provide a basic theoretical basis for the study of the transcriptome,proteome and intestinal microflora of the tree shrew under low temperature environment.(1)Comparison of metabolites in serum and liver of Tree shrews from different elevationsTo explore the effects of different altitudes on changes of different metabolites and metabolic pathways the sera and livers of T.belangeri,12 and 8 T.belangeri from Dali(high–altitude)and Mengla(low–altitude)were collected.The metabolites were analyzed by using the non-targeted metabonomics gas chromatography–mass spectrometry(GC–MS).The results showed that there were 37 different metabolites in serum of the high-altitude population compared to the low-altitude population,among which 33 were up-regulated(citric acid,glucose,cholesterol,et al.)and 4 were down-regulated(N-acetylpropionic acid,lauric acid,4-hdroxybutyric acid,et al.).There were 18 metabolites showing significant difference in the high-altitude population compared to the low-altitude population,among which 10 were up-regulated(malic acid,ribose,glucose,et al.)and 8 were down-regulated(glutamine,glycolic acid,octadecanoic acid,et al.).Compared with the serum metabolic pathways at low-altitude,there were 76 metabolic pathways with significantly different activity scores in high-altitude population,among which 69 were up-regulated and 7 were down-regulated.There were 75 metabolic pathways with significantly different activity scores in the high-altitude population compared with the low-altitude population,among which 44 were up-regulated and 31 were down-regulated.All of the above results suggest that T.belangeri would adjust the metabolites of different metabolic pathways(including tricarboxylic acid cycle,glycolysis,lipid metabolism and amino acid metabolism)in different tissues to adapt to different environments,and serum is more sensitive to environmental changes than the liver.(2)Comparison of different metabolites in adipose tissue of tree shrew under cold acclimationIn order to investigate the changes of different metabolites of white adipose tissue(WAT)and brown adipose tissue(BAT)in T.belangeri under cold acclimation,WAT and BAT were collected between control and cold acclimation group acclimated for 28 days in the present study,which were analyzed using non-targeted metabolome(liquid chromatography–mass spectrometer,LC–MS)detection technology.The results showed that 7 different metabolites were significantly up–regulated of WAT in cold acclimation group compared with that of control group;there were 25 different metabolites in BAT,among which 23 were up–regulated and 2 were down–regulated significantly,which were mainly involved in pathways of tricarboxylic acid cycle,lipid metabolism,amino acid metabolism and glucose metabolism.All of the above results indicated that T.belangeri could use different metabolites in different tissues to resist lower temperature and improve survival rate.In conclusion,T.belangeri are susceptible to the influence of the temperature of the external environment,compared with the relatively high temperature environment conditions,the serum,liver and adipose tissue metabolites relative content were changed,the metabolism of sugar,lipid metabolism,amino acid metabolism and the tricarboxylic acid cycle in the middle of the product changes significantly,intermediate metabolites involved in the metabolic pathways of activity changes significantly.It can be seen that tree shrews can regulate the metabolites of different tissues and organs and the metabolic pathways involved in the metabolites to adapt to different external environments.Moreover,their serum is more sensitive to environmental temperature changes than liver,and BAT is more sensitive to environmental temperature changes than WAT.