Transport stress-induced cerebrum oxidative stress is not mitigated by activating the Nrf2 antioxidant defense response in newly hatched chicks

Effects of rumen-protected creatine pyruvate on blood biochemical parameters and rumen fluid characteristics in transported beef cattle

Background

The fasting and stress associated with road transportation contributes to a lack of energy and a decline in the immune system of beef cattle. Therefore, it is essential for beef cattle to enhance energy reserves before transportation. Creatine pyruvate (CrPyr) is a new multifunctional nutrient that can provide both pyruvate and creatine, which are two intermediate products of energy metabolism. To investigate the effects of transport and rumen-protected (RP)-CrPyr on the blood biochemical parameters and rumen fluid characteristics of beef cattle, twenty male Simmental crossbred cattle (659 ± 16 kg) aged 18 months were randomly allocated to four groups (n = 5) using a 2 × 2 factorial arrangement with two RP-CrPyr supplemental levels (0 or 140 g/d) and two transport treatments (5 min or 12 h): T_CrPyr140, T_CrPyr0, NT_CrPyr140, and NT_CrPyr0. After feeding for 30 days, three cattle per treatment were slaughtered.

Results

Compared with nontransport, transport decreased the total antioxidant capacity, catalase activity, contents of IgA, interferon γ, interleukin-1β (IL-1β), and IL-6 in serum, and the amounts of total volatile fatty acids (TVFA), acetate, and butyrate in rumen (P < 0.05); increased the serum lipopolysaccharide (LPS) level, contents of rumen LPS and ammonia nitrogen (P < 0.05). RP-CrPyr supplementation decreased the levels of cortisol and LPS in serum and the butyrate concentration in the rumen of beef cattle compared with those in the unsupplemented groups (P < 0.05). RP-CrPyr and transport interaction had a significant effect on the contents of serum tumour necrosis factor-α, IL-6, LPS, ruminal pH, acetate content, and acetate/propionate (P < 0.05). In terms of ruminal bacterial composition, group T_CrPyr0 increased the Prevotella genus abundance compared with group NT_CrPyr0 (P < 0.05), while group T_CrPyr140 increased Firmicutes phylum abundance and decreased Bacteroidetes phylum and genus Prevotella abundance compared with group T_CrPyr0 (P < 0.05). Moreover, Bacteroidetes was positively correlated with serum LPS.

Conclusions

These results indicated that dietary supplementation with RP-CrPyr might be beneficial to alleviate transport stress by decreasing serum cortisol and LPS levels and promoting the restoration of the rumen natural flora.

Enriched environment housing improved the laying hen's resistance to transport stress via modulating the heat shock protective response and inflammation

An enriched environment can promote adaptability of animals to cope with complex environments. A total of 18-week-old 216 laying hens were randomly divided into 2 groups; of which, one group was housed in conventional battery cages (CC, n = 36), and the others were housed in furnished cages (FC, n = 180). At the end of 64 wk of age, 24 chickens of each group were selected for 4-hour transport treatment. The spleen tissues of laying hens were collected before transportation (BT), immediately after transportation, and at 48 h after transportation to detect the expression of the heat shock protective response signaling pathway and inflammatory factors. Serum samples were collected to detect the content of immune cytokines. Transport stress decreased heat shock proteins (HSP; including Small HSP, HSP27, HSP40, HSP60, HS70, HSP90, HSP110) in the CC group (P < 0.05), whereas there was no significant difference in the expression of HSP (except for Small HSP and HSP40) in the FC group (P > 0.05) immediately after transportation. At 48 h after transportation, mRNA levels of HSP (except for Small HSP and HSP40) in the FC group were upregulated, which were higher than those at BT (P < 0.05). The changes in HSP60, HSP70, and HSP90 protein levels had similar tendencies. The results showed that housing in furnished cages alleviated the inhibition of expression of HSP in the hens' spleen induced by transport stress. In addition, the hens housed in the FC group had lower expression levels of proinflammatory factors (nuclear transcription factor-kappa B, inducible nitric oxide synthase, cyclooxygenase-2, prostaglandin E synthase, inflammatory cytokines [IL-1β and IL-6], and tumor necrosis factor alpha) (P < 0.05). We suggest that the enriched environment can reduce transport stress damage in laying hens and improve resistance to transport stress by regulating expression of heat shock response proteins and inflammatory cytokines.

Antioxidant Defence Systems and Oxidative Stress in Poultry Biology: An Update

Poultry in commercial settings are exposed to a range of stressors. A growing body of information clearly indicates that excess ROS/RNS production and oxidative stress are major detrimental consequences of the most common commercial stressors in poultry production. During evolution, antioxidant defence systems were developed in poultry to survive in an oxygenated atmosphere. They include a complex network of internally synthesised (e.g., antioxidant enzymes, (glutathione) GSH, (coenzyme Q) CoQ) and externally supplied (vitamin E, carotenoids, etc.) antioxidants. In fact, all antioxidants in the body work cooperatively as a team to maintain optimal redox balance in the cell/body. This balance is a key element in providing the necessary conditions for cell signalling, a vital process for regulation of the expression of various genes, stress adaptation and homeostasis maintenance in the body. Since ROS/RNS are considered to be important signalling molecules, their concentration is strictly regulated by the antioxidant defence network in conjunction with various transcription factors and vitagenes. In fact, activation of vitagenes via such transcription factors as Nrf2 leads to an additional synthesis of an array of protective molecules which can deal with increased ROS/RNS production. Therefore, it is a challenging task to develop a system of optimal antioxidant supplementation to help growing/productive birds maintain effective antioxidant defences and redox balance in the body. On the one hand, antioxidants, such as vitamin E, or minerals (e.g., Se, Mn, Cu and Zn) are a compulsory part of the commercial pre-mixes for poultry, and, in most cases, are adequate to meet the physiological requirements in these elements. On the other hand, due to the aforementioned commercially relevant stressors, there is a need for additional support for the antioxidant system in poultry. This new direction in improving antioxidant defences for poultry in stress conditions is related to an opportunity to activate a range of vitagenes (via Nrf2-related mechanisms: superoxide dismutase, SOD; heme oxygenase-1, HO-1; GSH and thioredoxin, or other mechanisms: Heat shock protein (HSP)/heat shock factor (HSP), sirtuins, etc.) to maximise internal AO protection and redox balance maintenance. Therefore, the development of vitagene-regulating nutritional supplements is on the agenda of many commercial companies worldwide.

Regulation of lipid peroxidation and ferroptosis in diverse species

This review by Conrad et al. reviews the functions and regulation of lipid peroxidation, ferroptosis, and the antioxidant network in diverse species, including humans, other mammals and vertebrates, plants, invertebrates, yeast, bacteria, and archaea, and discusses the potential evolutionary roles of lipid peroxidation and ferroptosis.

Lipid peroxidation is the process by which oxygen combines with lipids to generate lipid hydroperoxides via intermediate formation of peroxyl radicals. Vitamin E and coenzyme Q₁₀ react with peroxyl radicals to yield peroxides, and then these oxidized lipid species can be detoxified by glutathione and glutathione peroxidase 4 (GPX4) and other components of the cellular antioxidant defense network. Ferroptosis is a form of regulated nonapoptotic cell death involving overwhelming iron-dependent lipid peroxidation. Here, we review the functions and regulation of lipid peroxidation, ferroptosis, and the antioxidant network in diverse species, including humans, other mammals and vertebrates, plants, invertebrates, yeast, bacteria, and archaea. We also discuss the potential evolutionary roles of lipid peroxidation and ferroptosis.