Changes in expression of insulin signaling pathway genes by dietary fat source in growing-finishing pigs

Abstract

This study investigated changes in gene expression by dietary fat source, i.e., beef tallow, soybean oil, olive oil, and coconut oil (each 3% in feed), in both male and female growing-finishing pigs. Real-time PCR was conducted on seven genes (insulin receptor; INSR, insulin receptor substrate; IRS, phosphatidylinositol (3,4,5)-triphosphate; PIP3, 3-phosphoinositide-dependent protein kinase-1; PDK1, protein kinase B; Akt, forkhead box protein O1; FOXO1 and cGMP-inhibited 3’, 5’-cyclic phosphodiesterase; PDE3) located upstream of the insulin signaling pathway in the longissimus dorsi muscle (LM) of pigs. The INSR, IRS, PIP3, and PDE3 genes showed significantly differential expression in barrow pigs. Expression of the PIP3 and FOXO1 genes was significantly different among the four dietary groups in gilt pigs. In particular, the PIP3 gene showed the opposite expression pattern between barrow and gilt pigs. These results show that dietary fat source affected patterns of gene expression according to animal gender. Further, the results indicate that the type of dietary fat affects insulin signaling-related gene expression in the LM of pigs. These results can be applied to livestock production by promoting the use of discriminatory feed supplies.

Complex cis-regulatory landscape of the insulin receptor gene underlies the broad expression of a central signaling regulator

“…In addition, physiological stimuli influence the expression of INSR, although the importance and consequences of this regulation are unknown. Diet, hormone levels and other signals impact INSR expression levels, as can viral infection and diabetes (Mamula et al, 1990;Kriauciunas et al, 1993;Chatterjee, 2001;Iritani et al, 2000;Gunton et al, 2005;Kim et al, 2014). Elevated levels of INSR expression are observed in numerous cancers, leading to an insulin-dependent growth phenotype (Belfiore and Malaguarnera, 2011).…”

Regulation of Swine Growth by Backfat Tissue during Growing and Finishing Stages

“…A previous study reported that pigs reached their highest fat content (~15%) at 21 days after birth [ 35 ]; thus, the fat synthesis gene becomes progressively less expressed after 21 days of postnatal development [ 35 ]. Similarly, here ‘Lipid catabolic process’ and ‘Protein kinase B signaling’, which include the degradation of fat through the Akt pathway [ 36 ], were significant in the 10 W group. Therefore, this indicated a decrease in fat synthesis depending on the growth rate, corresponding to the previous studies [ 35 , 36 ].…”

“…Similarly, here ‘Lipid catabolic process’ and ‘Protein kinase B signaling’, which include the degradation of fat through the Akt pathway [ 36 ], were significant in the 10 W group. Therefore, this indicated a decrease in fat synthesis depending on the growth rate, corresponding to the previous studies [ 35 , 36 ].…”

Effect of feeding less shell, extruded and enzymatically treated palm kernel cake on expression of growth-related genes in broiler chickens

“…The insulin signalling pathway mechanisms involve glucose storage and uptake, protein synthesis, and regulation of lipid synthesis (Kim et al 2014). Another gene that was found to be up-regulated in LSPKC and ETPKC fed-chickens was PRKCZ (p < .05), which plays an important role in the modulating insulin signalling pathways (Hassan et al 2016).…”