Conferencia: "Functional analysis of G-protein-coupled receptors during porcine subcutaneous preadipocytes differentiation"

Fecha de primera publicación: 12/07/2019

Conferencia: "Functional analysis of G-protein-coupled receptors during porcine subcutaneous preadipocytes differentiation"
Ponente: Dr. Masaaki Taniguchi (Animal Genome Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Japan).
Fecha: martes, 16 de julio
Horario: 12:00h
Lugar: Salón de actos del Lascaray
Resumen: G-protein-coupled receptors (GPCRs) are membrane proteins that enable cells to sense molecular signals and to respond in a broad range of biological processes according to the external circumstances of cells. Recent studies elucidated that short-medium chain fatty acids can stimulate GPCRs to activate signaling pathways for adipocyte differentiation. In order for the process of differentiation of Porcine Subcutaneous Pre-Adipocytes (PSPA), it has been demonstrated that octanoate (C8:0) supplementation in the differentiation medium is essential for growth arrest which triggers the differentiation initiation of PSPA followed by lipid synthesis and accumulation to develop into fully differentiated adipocyte. We, therefore, aimed to elucidate GPCR genes expressed at a semi-confluent phase of the PSPA using the Genome Sequencer FLX to obtain 5′ end of messenger RNA sequence. Consequently, we detected 11 candidate GPCR genes considered to be expressed before the PSPA differentiation induction. Of 11 GPCRs, leucine rich repeat containing G protein-coupled receptor 4(LGR4) gene appeared to be associated with preadipocytes differentiation by functional annotation of those GPCRs. So, we intended to analyze gene knockdown effect using transfection of small interfering RNA (siRNA) for LGR4 gene into the PSPA followed by differentiation induction. The result indicated that the knockdown of LGR4 gene obviously retarded the PSPA differentiation and decreased lipid synthesis in the cells. Therefore, we further investigated gene expression profiles of PSPA transfected with LGR4 siRNA using a porcine custom 4 × 44K microarray. Our result of the gene expression microarray indicated that larger numbers of downregulated genes were detected more than upregulated genes by the siRNA transfection. Gene ontology analysis elucidated that upregulated genes by LGR4 gene knockdown were categorized in biological processes of cell adhesion. Interestingly, downregulated genes, on the other hand, were categorized in PPAR signaling pathway which is known for the key pathway of adipogenesis and lipid synthesis. The adipocytes differentiation of PSPA might be attributable to the alteration of gene expression profiles regulated by LGR4 identified in this study.