Zinc Oxide Nanoparticle Improves the Intestinal Function of Intrauterine Growth Retardation Finishing Pigs via Regulating Intestinal Morphology, Inflammation, Antioxidant Status and Autophagy

Abstract

This study was to investigate effects of zinc oxide nanoparticle (Nano-ZnO) on growth, immunity, intestinal morphology and function of intrauterine growth retardation (IUGR) finishing pigs. Six normal birth weight (NBW) and 12 IUGR male piglets were obtained and weaned at 21 d. NBW-weaned piglets fed basal diets (NBW group), IUGR-weaned piglets allocated to two groups fed basal diets (IUGR group) and basal diets further supplemented 600 mg Zn/kg from Nano-ZnO (IUGR+Zn group), respectively. All pigs were slaughtered at 163 d. Results showed: (1) IUGR pigs showed no difference in body weight at 77d and 163d (P > 0.05), while had increased villus height (VH) and villus surface area in jejunum (P < 0.05) and enhanced interleukin-6, TNF-α and NF-κB mRNA expression (P < 0.05) as compared to NBW group; Compared with IUGR group, dietary Nano-ZnO did not affect the body weight (P > 0.05), but increased VH to crypt depth ratio and IgA concentration (P < 0.05) and decreased TNF-α and NF-κB mRNA expression in jejunum (P < 0.05). (2) IUGR increased the number of swollen mitochondria and autolysosomes, and protein expressions of sequestosome-1 (P62) and microtubule-associated protein light chain 3 B/A (LC3B/A) in jejunum as compared to NBW group (P < 0.05); Compared with IUGR group, Nano-ZnO decreased the number of swollen mitochondria and autolysosomes, and P62 and LC3B/A protein expression (P < 0.05). (3) IUGR increased mucosal contents of malondialdehyde and protein carbonyl (PC) and Keap1 protein expression (P < 0.05) as compared to NBW group; Compared with IUGR group, dietary Nano-ZnO increased activities of total antioxidant capacity, catalase, glutathione peroxidase, and glutathione content (P < 0.05), and enhanced nuclear respiratory factor 2 (Nrf2), glutamate-cysteine ligase modifier subunit and glutathione peroxidase 1 mRNA expression, and increased total and nuclear Nrf2 protein expression (P < 0.05), and decreased malondialdehyde and PC content, and Keap1 protein expression (P < 0.05) in jejunum. Results suggested that IUGR pigs showed postnatal catch-up growth and improved intestinal morphology, and dietary Nano-ZnO may further improve intestinal morphology, reduce inflammation, decrease autophagy and alleviate oxidative stress via Nrf2/Keap1 pathway in jejunum of IUGR pigs.

Effects of Long-Term Dietary Zinc Oxide Nanoparticle on Liver Function, Deposition, and Absorption of Trace Minerals in Intrauterine Growth Retardation Pigs

“…This experiment is part of a series of researches to study the effects of long-term dietary Nano-ZnO in IUGR pigs [Duroc × (Landrace × Yorkshire)]. Speci c experimental design has been described in previous study [19]. Brie y, a total of 18 male neonatal pigs were selected and grouped to NBW (6 normal birth weight piglets fed basal diet), IUGR (6 IUGR piglets fed basal diet) and IUGR + NZ (6 IUGR piglets fed basal diet + 600 mg Zn/kg from Nano-ZnO) groups at 21days of age (weaning age).…”

“…in the previous studies [9,19]. All the piglets were individually housed in stainless steel pen with the leaking manure oor at the appropriate temperature with unlimited access to feed and water.…”

“…The TEM sections of jejunum, liver and muscle were made as previously described [19]. Brie y, the xedsamples (2.5% glutaraldehyde solution for 48h) further xed with 1% osmium tetroxide, and dehydrated and embedded in epoxy resin.…”

“…As previously described [16,19], extracted the jejunal mucosal total RNA and obtained the cDNA samples, which were then reversed transcription polymerase chain reaction (RT-PCR). The β-actin (internal reference gene) and the 2…”

“…As a pregnancy syndrome in mammals, intrauterine growth retardation (IUGR) impairs fetal growth and development and negatively affects postnatal growth and feed utilization e ciency, bringing a host of economic losses to the global livestock industry every year, especially for the swine industry [15]. Dietary Nano-ZnO could effectively alleviate the IUGR induced intestinal oxidative stress, in ammatory response and excessive autophagy of pigs [16][17][18][19]. However, it remains unclear about the possible effects of dietary Nano-ZnO on development of organs, trace mineral metabolism and liver function in IUGR nishing pigs.…”