Temporal gene expression profiling of liver from periparturient dairy cows reveals complex adaptive mechanisms in hepatic function

Abstract

Long-term molecular adaptations in liver from high-producing dairy cows are virtually unknown. Liver from five Holstein cows was biopsied at -65, -30, -14, +1, +14, +28, and +49 days relative to parturition for transcript profiling using a microarray consisting of 7,872 annotated cattle cDNA inserts. More than 5,000 cDNA elements represented on the microarray were expressed in liver. From this set we identified 62 differentially expressed genes related to physiological state, with a false discovery rate threshold of P = 0.20. The dominant expression pattern consisted of upregulation from day -30 through day +1, followed by downregulation through day +28. There was a threefold decrease from day -65 through day +14 in expression of IGFBP3, GSTM5, and PDPK1. These genes mediate IGF-I transport, oxidative stress, and glucose homeostasis, respectively. IGFBP3, EIF4B, and GSTM5 mRNA levels were positively correlated with blood serum total protein. Correlation analysis showed positive associations between serum nonesterified fatty acids and mRNA expression for SAA1, CPT1A, ACADVL, and TFAP2A. Transcript levels of ACSL1, PPARA, and TFAP2A were positively correlated with serum beta-hydroxybutyrate. Expression patterns for certain genes (e.g., IGFBP3, HNF4A, GPAM) revealed adaptations commencing well ahead of parturition, suggesting they are regulated by factors other than periparturient hormonal environment. Results provide evidence that hepatic inflammatory responses occurring near parturition initiate or augment adipose catabolism. In this context, cytokines, acute-phase proteins, and serum nonesterified fatty acids are key players in periparturient cow metabolism. We propose a model for integrating gene expression, metabolite, and liver composition data to explain physiological events in placenta, adipose, and liver during the periparturient period.

Nutrition, immune function and health of dairy cattle

“…Insulin resistance is associated with a low-grade inflammation with adipose tissue, and partly liver tissue, as the main contributor to heightened inflammation in blood. In postpartal dairy cows, Loor et al (2005) observed an increase in hepatic mRNA expression of serum amyloid A (SAA1), a pro-inflammatory acute phase protein. Recent evidence shows that adipose tissue depots of Holstein cows are immune responsive, as reflected in greater mRNA abundance of TNFA and IL6 after stimulation with LPS in vitro (Mukesh et al, 2010).…”

Effects of herbage allowance of native grasslands in purebred and crossbred beef cows: metabolic, endocrine and hepatic gene expression profiles through the gestation–lactation cycle

“…Primers (Supplementary Table S1) to specifically amplify cDNA of target genes: GHR, GHR-1A, IGF1, IGF-binding proteins-2 and -3 (IGFBP2, IGFBP3), acyl-CoA oxidase-1 (ACOX1), acyl-CoA dehydrogenase very long chain (ACADVL), pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase-1 (PCK1), fibroblast growth factor-21 (FGF21) and peroxisome proliferator-activated receptor-α (PPARA), and from endogenous controls: β-actin (ACTB) and hypoxanthine phosphoribosyltransferase (HPRT) were obtained from the literature (Loor et al, 2005;Carriquiry et al, 2009;Astessiano et al, 2012) or specifically designed using Primer3 (http://frodo.wi.mit.edu/) and bovine nucleotide sequences available from NCBI (http://www.ncbi.nlm.nih.gov/). Before use, primer product size (1% agarose gel separation) and sequence (Macrogen, Inc., Seoul, Korea) were determined to ensure that primers produced the desired amplicons (Supplementary Tables S2 and S3).…”

“…The expression of IGFBP3 or the IGFBP3 to IGFBP2 ratio could represent possible mechanisms, whereby insulin regulates plasma IGF-I concentrations (Mashek et al, 2001;Loor et al, 2005;Carriquiry et al, 2009). Circulating IGF-I forms a ternary complex (IGFBP3/IGF-I) that increases IGF-I half-life and potentiates its role, whereas IGFBP2 inhibits IGF-I action by preventing the binding to its receptors (Rajaram et al, 1997).…”

“…This was reflected in the high correlations determined in this study between plasma insulin and IGF-I and the IGFBP3 to IGFBP2 mRNA ratio. Reduced IGFBP3 and increased IGFBP2 have been associated with NEB (Rajaram et al, 1997;Loor et al, 2005;Carriquiry et al, 2009). The greater IGFBP2 mRNA and reduced IGFBP3 to IGFBP2 mRNA ratio observed in LO than in HI cows, indicated a more severe nutrient restriction in the former ones (Rajaram et al, 1997) and could explain, at least partly, their reduced circulating IGF-I concentrations (Mashek et al, 2001).…”

“…Elevated GH and decreased insulin concentrations during NEB stimulate hepatic gluconeogenesis to supply glucose for the fetus or for lactose synthesis, and the use of non-esterified fatty acids (NEFA) mobilized from the adipose tissue to supply energy for peripheral needs (Bauman, 2000;McCarthy et al, 2010). Several authors have shown an increased activity and/or hepatic mRNA expression of rate-limiting enzymes involved in gluconeogenesis and/or fatty-acid oxidation during the NEB associated with the transition period in dairy cows (Drackley et al, 2001;Loor et al, 2005;McCarthy et al, 2010).…”