Longitudinal changes in adipose tissue of dairy cows from late pregnancy to lactation. Part 2: The SIRT-PPARGC1A axis and its relationship with the adiponectin system

Abstract

The transition period in dairy cows is characterized by major changes in glucose and adipose tissue metabolism. The Sirtuin-1 (SIRT1) PPARγ co-activator 1α (PPARGC1A) axis might be related to the adiponectin (ADIPOQ) system to orchestrate the regulation of these processes. We aimed to assess the mRNA abundance of the aforementioned components in one visceral and one subcutaneous fat depot, together with the ADIPOQ concentrations in serum of dairy cows from late gestation to early lactation. In addition, the effect of 2 diets differing in energy density was tested. Twenty pluriparous German Holstein cows were all kept on the same silage-based diet until d 42 antepartum. From then on until d 1 antepartum, 10 animals each were assigned to either high-concentrate (60:40 concentrate:roughage) or low-concentrate (30:70) diets. Both groups were further subdivided into a control and a niacin group, the latter receiving 24 g/d nicotinic acid from d -42 until d 24. From d 1 postpartum (p.p.) to d 24 p.p., the concentrate portion was increased from 30 to 50% for all cows. Biopsies of subcutaneous (SCAT) and retroperitoneal adipose tissue (RPAT) were taken at d -42, 1, 21, and 100 relative to parturition. Blood samples were drawn along with the biopsies as well as on d -21, -14, -7, -3, 1, 3, 7, 14, 21, 28, 35, 42, 63, 82, and 100 relative to calving. Quantification of target mRNA was done using quantitative PCR and serum ADIPOQ concentration was measured via ELISA. The feeding regimen did not affect the variables examined. Serum ADIPOQ concentrations decreased toward parturition, returned to precalving levels within 1 wk after parturition, and remained on a constant level until the end of the experiment. The mRNA abundance of SIRT1, PPARGC1A, NAMPT, and the ADIPOQ receptors 1 (ADIPOR1) and 2 (ADIPOR2) changed in SCAT and RPAT during the considered time period. Comparing SCAT and RPAT, the mRNA of SIRT1, ADIPOR1, and ADIPOR2 were more abundant in RPAT, whereas PPARGC1A and NAMPT were expressed more highly in SCAT. The protein abundance of SIRT1 tended to increase from d -42 to 21. At d 21 we detected more PPARGC1A protein in the low-concentrate group as compared with the high-concentrate group. The correlations observed point to a link between these factors and might hint to a functional role of the variables in the regulation of glucose metabolism. This study substantiates the existence of the SIRT1-PPARGC1A-axis and indicates a functional relationship between SIRT1 and ADIPOR1 in bovine adipose tissue.

Gain and loss of subcutaneous and abdominal fat depot mass from late pregnancy to 100 days in milk in German Holsteins

“…This was further supported by the fact that in the present study differences disappeared after 21 DIM when cell size is not different between depots anymore (Kenéz et al, 2015). Furthermore, the mentioned companion studies of Weber et al (2016aWeber et al ( , 2016b again confirm higher lipolytic potential in RPAT compared to SCAT due to differences in mRNA and protein expression of several effectors of lipolytic pathways. In the present study, MAT showed the biggest adL during fresh cow period.…”

“…Furthermore, the mentioned companion studies of Weber et al . (2016 a , 2016 b ) again confirm higher lipolytic potential in RPAT compared to SCAT due to differences in mRNA and protein expression of several effectors of lipolytic pathways. In the present study, MAT showed the biggest adL during fresh cow period.…”

“…Even though Weber et al . (2016 a , 2016 b ) in companion studies found higher mRNA expression of insulin dependent antilipolytic factors like hydroxycarboxylic receptor (HCAR) 1 and 2 in RPAT than in SCAT at −42 DIM, this did not lead to a relatively higher actual accretion of fat in AAT during dry period.…”

Disturbed bovine mitochondrial lipid metabolism: a review

“…Furthermore, SIRT3 deacetylates FOXO3 to protect mitochondria against oxidative stress (Tseng et al 2013). The existence of the SIRT1-peroxisome proliferator-activated receptor (PPAR) GC1A-axis has been demonstrated in dairy cows and indicates a functional relationship between SIRT1 and adiponectin type 1 receptor in bovine adipose tissue (Weber et al 2016).…”

Short communication: Adipocyte sizes in the digital fat pad and their relationship to body condition in dairy cows

“…Tissue homogenates (500 mg/mL) for WB were prepared with 10 mM HEPES, pH 7.4, according to Weber et al (2016). Samples were diluted to 0.5 mg of total protein/mL with water and mixed with loading buffer (final concentrations: 0.1 M Tris HCl pH 6.8, 1% SDS, 0.0032% bromophenol blue, 10% glycerol).…”