Conjugated linoleic acid synthesis-related protein proteasome subunit α 5 (PSMA5) is increased by vaccenic acid treatment in goat mammary tissue

Abstract

This study was conducted to identify proteins associated with the endogenous synthesis of conjugated linoleic acid (CLA) from trans-vaccenic acid (TVA; trans-11 C18:1, a precursor for CLA endogenous synthesis) in mammary tissues. Six lactating goats were divided into 2 groups. One group was given an intravenous bolus injection of TVA (150mg) twice daily over 4 d; the other group received saline injections. Treatment with TVA increased the concentration of cis-9,trans-11 CLA and TVA in goat milk. Additionally, TVA treatment increased the expression of stearoyl-CoA desaturase (SCD) in mammary tissue. Using 2-dimensional gel electrophoresis and electrospray ionization quadrupole time-of-flight mass spectrometry, 3 proteins affected by infusions of TVA were identified. Proteasome (prosome, macropain) subunit α type 5 (PSMA5) was upregulated, whereas peroxiredoxin-1 and translationally controlled tumor protein 1 were downregulated in TVA-treated animals compared with the vehicle-injected controls. Only the effect of TVA on PSMA5 could be confirmed by Western blot analysis. To further explore the regulation of PSMA5 in mammary epithelial cells when TVA is converted into CLA, we used a differentiated bovine mammary epithelial cell line treated with TVA for 6h. Changes in cis-9,trans-11 CLA concentrations and mRNA expression patterns of both SCD and PSMA5 were monitored. The concentration of cis-9,trans-11 CLA increased after TVA treatment. The mRNA expression level of PSMA5 was significantly elevated to 6h, but SCD mRNA expression only increased in 2h after TVA treatment. These results indicate that PSMA5 is highly expressed in goat mammary tissue and bovine mammary epithelial cells when TVA is converted into CLA. Our data suggest that PSMA5 protein is associated with CLA biosynthesis in mammary tissue.

Proteomic Analysis Reveals PGAM1 Altering cis‐9, trans‐11 Conjugated Linoleic Acid Synthesis in Bovine Mammary Gland

“…And the translational response of SCD1 observed in this study was partially consistent with some reports showing that trans-11 C18:1 can enhance SCD1 activity or SCD1 protein expression [7,14,15]. In another study, SCD1 mRNA expression in MAC-T cells was found to significantly increase after 2 h of incubation with trans-11 C18:1 (50 μM), but decreased thereafter [16].…”

Discovery and validation of the tumor-suppressive function of long noncoding RNA PANDA in human diffuse large B-cell lymphoma through the inactivation of MAPK/ERK signaling pathway

“…It mediates cancer cell invasion and proliferation by orchestrating several key biological processes during the development and progression of cancer [ 30 ]. For example, inhibition of MAPK signaling in breast cancer impairs proliferation and promotes apoptosis [ 31 ]. Interestingly, this signaling pathway are reported to be regulated by another lncRNA, MALAT1.…”

Stearoyl-CoA Desaturase Genes in Lipid Metabolism

“…( b ) Relationship between the responses (% of the control group) of SCD activity and milk cis-9-14:1/14:0 to the six lipid supplements Ollier et al 2009 ), the relationship between the responses of SCD1 mRNA and enzyme activity (means per treatment) to the eight lipid supplements (expressed relative to the control) was relatively weak ( r = 0.55), which may indicate the existence of putative post-traductional regulatory events. In the same way, a recent study in goats using a proteomic analysis suggested an increased protein expression of PSMA5 (proteasome subunit α type 5) and a higher mRNA abundance of SCD in the mammary tissue following trans-11-18:1 treatment (by intravenous bolus injection) (Jin et al 2012 ). SCD is a short-lived integral membrane protein of the endoplasmic reticulum (Oshino and Sato 1972 ), and PSMA5 as a part of the ubiquitin proteasome system may be involved in constitutive SCD degradation, and thus could play a role in SCD regulation as further suggested in MAC-T cells (Jin et al 2012 ).…”