The stress signalling pathway nuclear factor E2-related factor 2 is activated in the liver of sows during lactation

Abstract

BackgroundIt has recently been shown that the lactation-induced inflammatory state in the liver of dairy cows is accompanied by activation of the nuclear factor E2-related factor 2 (Nrf2) pathway, which regulates the expression of antioxidant and cytoprotective genes and thereby protects tissues from inflammatory mediators and reactive oxygen species (ROS). The present study aimed to study whether the Nrf2 pathway is activated also in the liver of lactating sows.FindingsTranscript levels of known Nrf2 target genes, UGT1A1 (encoding glucuronosyltransferase 1 family, polypeptide A1), HO-1 (encoding heme oxygenase 1), NQO1 (encoding NAD(P)H dehydrogenase, quinone 1), GPX1 (encoding glutathione peroxidase), PRDX6 (encoding peroxiredoxin 6), TXNRD1 (encoding thioredoxin reductase 1), and SOD (encoding superoxide dismutase), in the liver are significantly elevated (between 1.7 and 3.1 fold) in lactating sows compared to non-lactating sows. The inflammatory state in the liver was evidenced by the finding that transcript levels of genes encoding acute phase proteins, namely haptoglobin (HP), fibrinogen γ (FGG), complement factor B (CFB), C-reactive protein (CRP) and lipopolysaccharide-binding protein (LBP), were significantly higher (2 to 8.7 fold) in lactating compared to non-lactating sows.ConclusionsThe results of the present study indicate that the Nrf2 pathway in the liver of sows is activated during lactation. The activation of Nrf2 pathway during lactation in sows might be interpreted as a physiologic means to counteract the inflammatory process and to protect the liver against damage induced by inflammatory signals and ROS.

Changes in Nrf2 Expression in the Spinal Cord in Mouse Model of Experimental Autoimmune Encephalomyelitis

“…An inflammatory response and oxidative stress are detected in MS, and Nrf2 has been reported as being closely related to these inflammatory and oxidative stresses in the brain of MS patients (Gilgun-Sherki et al, 2004;Pöllinger et al, 2009;Johnson et al, 2010;Rosenbaum et al, 2012). In our EAE-modeled spinal cords, increased Nrf2 protein levels were again confirmed.…”

Potential of plant polyphenols to combat oxidative stress and inflammatory processes in farm animals

“…Recent studies have shown that lactation is another metabolic condition which is associated with the development of inflammation in the liver of pigs (Rosenbaum et al., ,b). It is likely that the induction of inflammation in the liver of lactating sows – which was also associated with the development of stress of the endoplasmic reticulum (ER stress), a condition triggered by inflammation – might be due to oxidative stress caused by the high metabolic activity or the occurrence of infectious diseases such as mastitis or metritis which are commonly observed in sows after parturition (Gessner et al., ,b).…”

Protective Effects of Polydatin on Septic Lung Injury in Mice via Upregulation of HO-1

“…Recent studies show that PD has obvious antioxidant property thought increasing the activities of superoxide dismutase (SOD) and catalase (CAT) [41, 42]. In fact, Nrf2 is an important regulator against oxidative stress, which increases the expression of HO-1, SOD, and CAT [43]. Thereby, we speculate that PD may be through the mechanism of Nrf2 activation to upregulation of HO-1.…”