A Study On The Effects Of Chiroric Acid On Hypoxia Adaptation And Immune Function Of Perioheral Blood Mononuclear Cell In Yak

The Qinghai-Tibet Plateau,known as the"roof of the World",is one of the harshest living environments in which are inhabited by humans and animals.Yak（Bos Grunniens）is a kind of wild cattle species on the Qinghai-Tibet Plateau and mainly distributed in the area above 3500 meters.Yak has good adaptability to the hypoxic environment.Chicoric acid belongs to caffeic acid,which is one of the most abundant phenolic compounds in echinacea,and it is also one of the significant characteristic components and important immune active ingredients.Intense investigations have demonstrated multiple regulatory functions of chicoric acid,including immune enhancement,anti-inflammatory,anti-nociceptive,and anti-angiogenic.Moreover,it also serves as a potent HIV integrase inhibitor and prevents free radicals-mediated degradation of collagen.Thus,via vitro and in vivo,the aim of this study was to analyze potential influences of chicoric acid on adaptation to hypoxia and immune function of PBMC in Datong Yak.Results gleaned from this study will provide valuable information about prevention of plateau sick and hypoxia-related diseases.Besides,it also provides theoretical basis for the development,application and promotion of cichoric acid in livestock feed.The main results obtained in this study are as follows:1.Chicoric acid elevated hypoxia adaptation of growing yak.The results show that chicoric acid significantly improved the levels of RBC,HGB,and WBC（P<0.05）.Moreover,it significantly increases TP and HDL-C contents in serum（P<0.05）;the supplement of chicoric acid（150,200 mg/d）greatly decreased the content of TG（P<0.05）.With treating chicoric acid,T-AOC and GSH-Px were obviously increased（P<0.05）,whereas MDA was decreased（P<0.05）.In serum,many hypoxia-inducible factors,such as HIF-2α,EPO,ROS,Fe³⁺,and Tf,are all significantly decreased（P<0.05）.The myocardial mitochondrial parameters including mtDNA,UCP2,PGC1-α,NRF1 and mitochondrial complexes were altered remarkably.Overall,chicoric acid has shown a positive effect on the adaptive ability of yak in high altitude.2.The effects of feeding cichoric acid on blood biochemical parameters,antioxidant capacity and immune function of perinatal grazing yak.The results showed that the levels of BUN,MDA,and the activity of GOT in serum form CA group were significantly lower than those in control group（P<0.05）.Conversely,the levels of GLU and ALP in serum,activitise of GSH-Px,SOD and T-AOC in treatment were significantly higher as compare with control group（P<0.05）.Our observations suggested that the dietary supplement of cichoric acid（150mg/d）could improve the antioxidant capacity and immune function of yak in perinatal period.Additionally,no significant side-effect of hepatorenal function was detected.3.Using RNA-seq technology,in yak PBMC 6807 differentially expressed genes were identified between CA treatment and the control.3788 genes were significantly up-regulated and 3019 genes were significantly down-regulated,meanwhile KEGG pathway enrichment analysis also shows that cell proliferation,immune and hypoxia adaptation and mitochondrial function signaling pathways are highly enriched.The expression of Yak PBMC proliferation-associated gene（CCNF,CCND1,and CDK4）were significantly promoted,whereas anti-proliferation-associated gene（TP53 and CDKN1A）were inhibited;inflammatory factors including IL-2,IL-6,AIF2,and CD97 mRNA expression were significantly up-regulated,the transcriptions of HIF1α,VEGF,CPT2,GPX4 were significantly up-regulated whereas GPLD1 expressed genes was significantly down-regulated.4.The results came from the CCK8,flow cytometry and EdU technologies have shown that the cichoric acid promoted proliferation of PBMC by combining the Con A and exhibited dose-dependent effect,with best inducing effect at 60μg/mL.Synchronously,the cichoric acid promoted the transformation from G0/G1 phase to S phase and G2/M phase by binding to Con A in yak PBMC,indicating that CA can promote PBMC proliferation during mitosis S,and accelerate the synthesis of PBMC DNA,and increase the expression of PCNA,CDK4and Bcl-2.In turn,it inhibits the expression and transcription of TP53 and decreases the expression of Bax and Caspase-3,suggesting that CA may regulate the immune function of yak through promoting PBMC proliferation and inhibiting apoptosis.In summary,CA can effectively promote nutritional metabolism,enhance hypoxia adaptationl of yak and improve immune function.These findings will be valuable for the treatment and prevention of altitude sickness as well as other hypoxia-related diseases.Furthermore,this research is of great significance for the development of health food and medical treatment based on CA.