Effect of dietary manganese on antioxidant status and expression levels of heat-shock proteins and factors in tissues of laying broiler breeders under normal and high environmental temperatures

Abstract

To investigate the effect of Mn on antioxidant status and expression levels of heat-shock proteins/factors in tissues of laying broiler breeders subjected to heat challenge, we used a completely randomised design (n 6) with a factorial arrangement of 2 environmental temperatures (normal, 21 (SEM 1)°C and high, 32 (SEM 1)°C) × 3 dietary Mn treatments (an Mn-unsupplemented basal diet (CON), or a basal diet supplemented with 120 mg Mn/kg diet as inorganic Mn sulphate (iMn) or organic Mn proteinate (oMn)). There were no interactions (P > 0·10) between environmental temperature and dietary Mn in all of the measured indices. High temperature decreased (P < 0·003) Mn content, and also tended (P = 0·07) to decrease copper zinc superoxide dismutase (CuZnSOD) activity in the liver and heart. However, an increased manganese superoxide dismutase (MnSOD) activity (P < 0·05) and a slight increase of malondialdehyde level (P = 0·06) were detected in breast muscle. Up-regulated (P < 0·05) expression levels of heat-shock factor 1 (HSF1) and HSF3 mRNA and heat-shock protein 70 (HSP70) mRNA and protein were found in all three tissues. Broiler breeders fed either iMn or oMn had higher tissue Mn content (P < 0·0001), heart MnSOD and CuZnSOD activities (P < 0·01) and breast muscle MnSOD protein levels (P < 0·05), and lower (P < 0·05) breast muscle HSP70 mRNA and protein levels than those fed CON. Broiler breeders fed oMn had higher (P < 0·03) bone Mn content than those fed iMn. These results indicate that high temperature decreases Mn retention and increases HSP70 and HSF1, HSF3 expression levels in tissues of laying broiler breeders. Furthermore, dietary supplementation with Mn in either source may enhance heart antioxidant ability and inhibit the expression of HSP70 in breast muscle. Finally, the organic Mn appears to be more available than inorganic Mn for bone in laying broiler breeders regardless of environmental temperatures.Key words: Broiler breeders: Manganese: Heat stress: Antioxidant status: Heat-shock proteins/factorsThe effect of heat stress on productive performance has been extensively studied in poultry, especially in high-producing hens (1)(2)(3)(4) . High environmental temperature negatively influences the performance of laying commercial hens (1,2) and broiler breeders (3,4) by reducing feed intake, egg production and eggshell quality. In addition to altered productive performance, heat stress can also disturb the redox balance and induce oxidative stress, with the production of reactive oxygen species (ROS), in broiler breeders (5) and commercial hens (6) . Although substantial attention has been paid to the roles of antioxidant trace minerals (Se, Zn) in minimising the harmful effect of heat stress in broilers (7) and commercial laying hens (8) , the role of Mn in stress reduction has not been well studied. Mn is a crucial component of the metalloenzyme manganese superoxide dismutase (MnSOD) (9) , which has a key role in the detoxification of superoxide free radicals. A series of studies in our laboratory...

Maternal dietary zinc supplementation enhances the epigenetic-activated antioxidant ability of chick embryos from maternal normal and high temperatures

“…As described previously [38], the homogenates of the embryonic liver samples were prepared to determine the total protein content, MDA and MT4 levels and CuZnSOD activity. The levels of total protein MDA and MT4 were determined using a BCA Protein Assay kit (Cat #23225, Pierce, Rockford, IL, USA), a commercial assay kit (Cat #A003-1, Nanjing Jiancheng Bioengineering Institute) and a Chicken MT4 ELISA Kit (Cat #CG3309, Waltham), respectively.…”

“…The geometric mean of internal references, β-actin and glyceraldehyde 3-phosphate dehydrogenase ( GAPDH ), was used to normalize the expressions of the targeted genes. The 2 −ΔΔCt was used to calculate mRNA level of each target gene [38]. …”

“…Total protein was extracted from frozen samples of the embryonic liver tissue as described previously [38]. The protein specimens (25 μg protein/lane) were separated on a 12% SDS-polyacrylamide gel and blotted on transferred to PVDF membranes (Cat #IPVH00010, Merck-Millipore).…”

Manganese enhances the expression of the manganese superoxide dismutase in cultured primary chick embryonic myocardial cells

“…The diet samples were collected for analyses of dietary Mn, Ca and CP contents, and the eggs collected from laying broiler breeders were separated to get egg yolks for analysis of egg yolk Mn content. The Mn and Ca contents were measured using an inductively coupled plasma emission spectroscope (model IRIS Intrepid II; Thermo Jarrell Ash, USA) after wet digestions with HNO 3 and HClO 4 , as described by Zhu et al (2015a). Validation of the mineral analysis was conducted using bovine liver powder (GBW (E) 080193; National Institute of Standards and Technology, China) as a standard reference material.…”

“…The MnSOD mRNA level was determined as described by Zhu et al (2015a) with slight modifications. Briefly, a total of 1 μg of RNA was used to obtain complementary DNA (cDNA) by reverse transcription using the QuantiTect Reverse Transcription Kit (Cat no.…”