In the cytosol, OAA can also be converted into PEP by PCK1
. This pathway is predominant when an amino acid such as alanine is the glucogenic precursor.
The cDNA probes for detecting apolipoprotein E (Apoe), fatty acid synthase (Fas), Gck, insulin-like growth factor-binding protein (Igfbp-1), and Pck1
genes have been published previously (23).
(a) G6PC, (b) PCK1
, and (c) FBPase mRNA expression levels in mice liver of the diabetes, diabetes + KD, and diabetes + KD + AE groups, after 6-week intervention.
A selected gene panel from the genes identified by microarray analysis data based on their involvement in adipogenesis-related processes, including AdipoQ, AP2, PPAR[gamma]2, CEBP[alpha], CNTFR, LPL, LIPE, ACACB, and PCK1
, was chosen for validation using qRT-PCR (Figure 2(c)).
For example, PCK1
, PLIN4, and FABP5 were all increased to a greater extent by TPP.
Relative mRNA abundance of the G6pc (a), Pck1
(b), Acaca (c), Fasn (d), Scd1 (e), Hsd11b1 (g), and Hsd11b2 (h) genes in the liver tissue from either C57BL/6J mice fed either Western diet for 20 weeks (black panels) or 14-week-old db/db mice (gray panels).
Three catabolic enzymes that are involved in glucose metabolism were included in the "Metabolism" pathway: pck1
(phosphoenolpyruvate carboxykinase 1), pcxb (pyruvate carboxylase b), and pgd (phosphogluconate dehydrogenase).
Hsieh et al., "Phosphoenolpyruvate carboxykinase (Pck1
) helps regulate the triglyceride/fatty acid cycle and development of insulin resistance in mice," Journal of Lipid Research, vol.
The Igfbpl promoter shares common insulin regulatory response elements with the phosphenolpyruvate carboxykinase (Pck1
) gene, which catalyzes the rate-limiting and committed step in gluconeogenesis, although different mechanisms are used by insulin to inhibit expression of these two genes (Yeagley et al.
Candidate genes phosphoenolpyruvate carboxykinase 1 (PCK1
) and bone morphogenetic protein 7 (BMP7) are located adjacent to the block.
The other subtype, PCK1
, and the insulin receptor were however not differentially expressed between the groups (Figure 5(b)).
Consequently, FoxO1 is not capable of enhancing the expression of two vast gluconeogenic executors, PCK1
(phosphoenolpyruvate carboxykinase 1) and G6PC (glucose 6-phosphatase).