Analysis Of Similarities And Differences At Transcriptional Level In Four Tissues Between Young And Old Pigs

Aging as a complex biological process,and its development process will seriously affect the function of cardiac muscle,skeletal muscle,liver and brain tissue,and even cause age-related diseases of these tissues.The microRNAs,lncRNAs and circRNAs have been found to be closely related to aging in mammals.As the regulatory mechanisms of competitive endogenous RNAs closely related to these RNA,they may also play an important role in the aging process.Up to now,few studies have studied the changes of transcriptional level related to aging in cardiac muscle,skeletal muscle,liver and brain tissues,including mRNA,lncRNA,microRNA and circRNA,and the co-expression characteristics of aging-related competitive endogenous RNA.Pig not only have similar metabolic functions,cardiovascular systems,proportional organs size,but also highly similar to humans in genetics,especially metabolic similarity of genetic determinations.They have been used as biomedical models to study human related diseases.Therefore,based on RNA-seq and bioinformatics analysis,we used the 180-days and 8-years Yana pigs to ananlyze the similarities and differences at transcriptional level in porcine cardiac muscle,skeletal muscle,liver and brain tissue between young and old pigs.The main results were shown as following:(1)In porcine cardiac muscle tissue,26 mRNA,4 lncRNA,22 miRNA and 26 circRNA were found differentially expressed with age.Compared with young cardiac muscle tissue,the up-regulated genes in old cardiac muscle tissue were related to structural proteins,triglyceride catabolic metabolic,and oxygen transport etc,and the down-regulated genes in old cardiac muscle tissue were related to the structural molecule,gene transcription and calcium binding capacity etc.(2)In porcine skeletal muscle tissue,81 mRNA,5 lncRNAs,79 miRNA and 62 circRNA were found differentially expressed with age.Compared with young skeletal muscle,the up-regulated genes in old skeletal muscle were related to immune response,cell differentiation,metabolic process,glucose transport,and apoptotic process etc,and the down-regulated genes in old skeletal muscle were related to structural proteins,DNA binding,neuron development and smoothened binding etc.(3)In porcine liver tissue,273 mRNA,19 lncRNA,26 miRNA and 103 circRNA were found differentially expressed with age.Compared with young liver tissue,the up-regulated genes in old liver tissue were related to immune response,regulating cell differentiation,stress response,and storage of lipids etc,and the down-regulated genes in old liver tissue were related to diphosphatase activity,regulation of signaling pathway,and metabolic process etc.(4)In porcine brain tissue,714 mRNA,38 lncRNAs,41 miRNA were found differentially expressed with age.Compared with young brain tissue,the up-regulated genes in old brain tissue were related to reproductive process,immune response,locomotion and metabolic process etc,and the down-regulated genes in old brain tissue were related to neurologic function,stress response,signaling pathway and immune response etc.(5)In the ceRNA co-expression networks of cardiac muscle tissue,there are 9 miRNA and 4 circRNA,age-related genes,including 11 co-expression relationships.In the ceRNA co-expression networks of skeletal muscle tissue,there are 26 miRNA and 17 circRNA,age-related genes,including 69 co-expression relationships.In the ceRNA co-expression networks of liver tissue,there are 5 miRNA and 13 circRNA,age-related genes,including 13 co-expression relationships.In the ceRNA co-expression networks of brain tissue,there are 11 miRNA and 54 circRNA,age-related genes,including 62 co-expression relationships.(6)The majority of mRNA,lncRNA and miRNA in porcine cardiac maucle,skeletal muscle,liver and brain tissues were co-expressed in young and old individuals,while only a small proportion of circRNA were co-expressed in young and old individuals.In addition,there were significant differences in the number and biological functions of age-related genes in these tissues.In this study,we analyzed the similarities and differences at the transcriptional level in cardiac muscle,skeletal muscle,liver and brain tissue between young and old pigs,it contribute to better understanding the aging related changes at transcriptional level in these tissues.In addition,the results can also provide references for the studies of the genetic resources protection of Yanan pig and the molecular regulation mechanism related to aging of human tissues.