LncRNA NRON Regulates Adipogenesis Through The Autophagy Pathway In The Chicken

The long non-coding RNA NRON(NRNA repressor of the nuclear factor of activated T cells)is an inhibitor of nuclear factor NFAT(nuclear factor of activated T cells).Recent studies have found that NRON and NFAT are related to the development of myocardium and skeletal muscle,and to the differentiation of adipocytes as well.In addition,the activation of NFAT protein activity depends on calcium/calmodulin-dependent phosphatase and calcineurin(Cn)pathways,and calcineurin is involved in the regulation of NFAT dephosphorylation,affecting NRON and NFAT through the formation of RNA-protein complex.This calcium signaling pathway can regulate the formation of lysosomes,affect the autophagosome to perform the degradation function.Thus,the long non-coding RNA NRON may regulate adipogenesis in broilers through the autophagy pathway.In the current study,the Northeast Agricultural University High and Low fat broiler lines(NEAUHLF)were used,broiler tissues and preadipocytes were used,and basic molecular biology experiments(Real-time RT-PCR,Western Blot,cell culture,PCR-RFLP technology,etc.)were performed.The relationship between NRON and adipogenesis of broiler chickens was preliminarily discussed.The main findings were as follows:(1)Based on the results of whole genome resequencing of NEAUHLF chickens,multiple SNP sites were detected and verified on the NRON gene.RFLP genotyping and association analyses of SNPs in NRON gene revealed that NRON was significantly associated with the heart weight(P < 0.05).(2)The gene expression patterns of different tissues in seven-weeks-old chickens were detected.Between the high and low fat chickens,it was found that the expression of NRON gene in the heart,glandular and muscular stomachs,and pectoral muscles was significantly different(P<0.01).In addition,in the abdominal adipose tissues,expression levels of NRON and NFAT were significantly different,at 1,4,and 7 weeks of age(P<0.05).(3)The expression patterns of NRON and NFAT were detected in primary preadipocytes and immortalized preadipocyte lines.It was found that NRON expression in immortalized preadipocytes was not significantly different,but with the differentiation of preadipocytes,NRON and NFAT transcription levels gradually increased.The expression of NRON in primary preadipocytes was consistent with that of PPARγ.(4)In oleic acid-induced differentiation of primary preadipocytes and immortalized preadipocyte lines,after inhibiting calcineurin with CsA,an important factor in NFAT dephosphorylation and also related to autophagy pathway,preadipocyte differentiation was promoted.(5)The mRNA and protein expression levels of autophagy-related genes BECN1 and ATG5 were detected in abdominal adipose tissues and preadipocytes of chickens at different ages.We found that transcription and protein expression level of BECN1 was high in the fat line,but not significantly different.In conclusion,our findings show that NRON is related to the growth and development of heart and muscle in broilers,and could potentially be involved in the regulation of adipogenesis.How NRON participates in the autophagy pathway and regulates adipogenesis remains to be further studied.