Analysis of gene expression profiles at different stages during preadipocyte differentiation in rabbits.

Excessive accumulation of fat is harmful to human health. The preadipocyte differentiation is a critical process of fat development. Studying the expression profiles of genes related to preadipocyte differentiation contributes to understanding of the mechanism of fat accumulation. Despite being considered an ideal animal model for studying adipogenesis, little is known about the gene expression profiles at different stages during preadipocyte differentiation in rabbits. In the present study, rabbit preadipocytes were cultured in vitro and induced for differentiation, and gene expression profiles of adipocytes collected at days 0, 3, and 9 of differentiation were analyzed by RNA-seq. We identified 1352 differentially expressed genes (DEGs) when comparing day 3 with day 0 and identified 888 DEGs when comparing day 9 with day 3. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the PPAR signaling pathway and PI3K-Akt signaling pathway were significantly enriched by the DEGs that up-regulated within the period of day 0 - day 3, and the GO terms and KEGG pathways that were associated with cell cycle were enriched by the DEGs that up-regulated within the period of day 3 - day 9. The DEGs that specifically up-regulated within the period of day 0 - day 3 might play roles in the cytoplasm, and the DEGs that specifically up-regulated within the period of day 3 - day 9 might act in the nucleus. The protein-protein interaction (PPI) network constructed by DEGs showed that hub node genes might modulate rabbit preadipocyte differentiation via regulating cell cycle.

Genome-wide identification and characterization of long non-coding RNAs during differentiation of visceral preadipocytes in rabbit.

Emerging evidence suggests that long non-coding RNAs (lncRNAs) are critical regulators of diverse biological processes, including adipogenesis. Despite being considered an ideal animal model for studying adipogenesis, little is known about the roles of lncRNAs in the regulation of rabbit preadipocyte differentiation. In the present study, visceral preadipocytes isolated from newborn rabbits were cultured in vitro and induced for differentiation, and global lncRNA expression profiles of adipocytes collected at days 0, 3, and 9 of differentiation were analyzed by RNA-seq. A total of 2066 lncRNAs were identified from nine RNA-seq libraries. Compared to protein-coding transcripts, lncRNA transcripts exhibited characteristics of a longer length and lower expression level. Furthermore, 486 and 357 differentially expressed (DE) lncRNAs were identified when comparing day 3 vs. day 0 and day 9 vs. day 3, respectively. Target genes of DE lncRNAs were predicted by the cis-regulating approach. Prediction of functions revealed that DE lncRNAs when comparing day 3 vs. day 0 were involved in gene ontology (GO) terms of developmental growth, growth, developmental cell growth, and stem cell proliferation, and involved in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of PI3K-Akt signaling pathway, fatty acid biosynthesis, and the insulin signaling pathway. The DE lncRNAs when comparing day 9 vs. day 3 were involved in GO terms that associated with epigenetic modification and were involved in the KEGG pathway of cAMP signaling pathway. This study provides further insight into the regulatory function of lncRNAs in rabbit visceral adipose and facilitates a better understanding of different stages of preadipocyte differentiation.