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    Determination of the trace minerals requirements for maintenance and growth of 35-50 kg Dorper x Hu crossbred ram lambs
    (Taylor & Francis Ltd, 2020) Zhang, Hao; Zhang, Ying; Peng, Along; Nie, Haitao; Wang, Feng; Elsabagh, Mabrouk; Loor, Juan J.
    This study aimed at estimating the trace minerals net requirements for maintenance and growth of Dorper x Hu ram lambs using the comparative slaughter techniques in 35 lambs of 35-50 kg body weight (BW). Seven lambs were slaughtered at the initial BW (34.93 +/- 0.37 kg) to determine the basal whole-body composition. Another seven lambs were fed ad libitum (AL) and then slaughtered when it reached 41.73 +/- 0.53 kg BW. The remained 21 lambs were assigned into three treatment groups, seven animals each, and fed 100, 70 or 40% of AL intake, respectively, and were slaughtered when they reached a BW of 49.93 +/- 1.03 kg. The net requirements of maintenance were 5.1, 429.3, 94.0 and 48.8 mu g/kg empty BW (EBW) for Mn, Fe, Zn and Cu, respectively. The net requirements of growth at 35 kg BW were 0.86, 70.41, 33.46 and 4.31 mg/kg EBW for Mn, Fe, Zn and Cu, respectively. At a BW of 50 kg, the net growth requirements were 0.93, 68.40, 35.20 and 4.15 mg/kg EBW for Mn, Fe, Zn and Cu, respectively. Our data indicated that the Mn and Zn requirements increase, whereas those of Fe and Cu decrease when BW increases. In addition, the net Cu, Mn and Fe requirements for maintenance and Zn, Cu, Mn and Fe requirements for growth of Dorper x Hu hybrid ram lambs were higher than those reported in the NRC but Zn requirements for maintenance matched that of the NRC.
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    Dietary N-carbamylglutamate and L-arginine supplementation improves redox status and suppresses apoptosis in the colon of intrauterine growth-retarded suckling lambs
    (Keai Publishing Ltd, 2022) Zhang, Hao; Zheng, Yi; Zha, Xia; Liu, Xiaoyun; Ma, Yi; Loor, Juan J.; Elsabagh, Mabrouk
    Previous studies have revealed that dietary N-carbamylglutamate (NCG) or L-arginine (Arg) improves small intestinal integrity and immune function in suckling Hu lambs that have experienced intrauterine growth retardation (IUGR). Whether these nutrients alter redox status and apoptosis in the colon of IUGR lambs is still unknown. This study, therefore, aimed at investigating whether dietary supplementation of Arg or NCG alters colonic redox status, apoptosis and endoplasmic reticulum (ER) stress and the underlying mechanism of these alterations in IUGR suckling Hu lambs. Forty-eight 7-d old Hu lambs, including 12 with normal birth weight (4.25 +/- 0.14 kg) and 36 with IUGR (3.01 +/- 0.12 kg), were assigned to 4 treatment groups (n = 12 each; 6 males and 6 females) for 3 weeks. The treatment groups were control (CON), IUGR, IUGR + Arg and IUGR + NCG. Relative to IUGR lambs, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) content, as well as proliferation index, were higher (P < 0.05) whereas reactive oxygen species (ROS), malondialdehyde (MDA) levels and apoptotic cell numbers were lower (P < 0.05) in colonic tissue for both IUGR + Arg and NCG lambs. Both mRNA and protein levels of C/ EBP homologous protein 10 (CHOP10), B-cell lymphoma/leukaemia 2 (Bcl-2) -associated X protein (Bax), apoptosis antigen 1 (Fas), activating transcription factor 6 (ATF6), caspase 3, and glucose-regulated protein 78 (GRP78) were lower (P < 0.05) while glutathione peroxidase 1 (GPx1), Bcl-2 and catalase (CAT) levels were higher (P < 0.05) in colonic tissue for IUGR + Arg and IUGR + NCG lambs compared with IUGR lambs. Based on our results, dietary NCG or Arg supplementation can improve colonic redox status and suppress apoptosis via death receptor-dependent, mitochondrial and ER stress pathways in IUGR suckling lambs.(c) 2022 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/).
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    Dietary supplementation of l-arginine and N-carbamylglutamate enhances duodenal barrier and mitochondrial functions and suppresses duodenal inflammation and mitophagy in suckling lambs suffering from intrauterine-growth-restriction
    (Royal Soc Chemistry, 2020) Zhang, Hao; Ma, Yi; Wang, Mengzhi; Elsabagh, Mabrouk; Loor, Juan J.; Wang, Hongrong
    The current work aimed at investigating the effects of the dietary supplementation of N-carbamylglutamate (NCG) or l-arginine (Arg) on the duodenal mitophagy, mitochondrial function, inflammation, and barrier function in suckling lambs suffering from intrauterine-growth-retardation (IUGR). Forty-eight neonate Hu lambs were used in this study: 12 lambs with normal birth weight (NBW: 4.25 +/- 0.14 kg) and 36 lambs with IUGR (3.01 +/- 0.13 kg). Seven day old lambs were assigned to 4 treatment groups (12 lambs in each group) as follows: control group (CON), IUGR group, IUGR + Arg, and IUGR + NCG. Lambs were fed the experimental diets for 21 days from 7 days to 28 days of age. Compared with IUGR lambs, the Arg or NCG-treated IUGR lambs had a markedly higher duodenal transepithelial electrical resistance (TER) and lower fluorescein isothiocyanate dextran (FD4) (P < 0.05), respectively. The duodenal mitochondrial membrane potential change (Delta psi(m)), relative mitochondrial DNA (mtDNA) content, adenosine triphosphate (ATP) level, together with the activities of the respiratory complexes I, III, and IV were markedly higher in Arg or NCG-treated IUGR lambs than those in non-supplemented IUGR lambs (P < 0.05). The expressions of the integrity-related proteins (occludin and zonula occludens-1 (ZO-1)), antioxidant- and apoptosis-related proteins (B-cell lymphoma/leukaemia 2 (Bcl2), superoxide dismutase 2 (SOD2), catalase (CAT), and glutathione peroxidase 1 (GPx1)), and the nitric oxide-dependent pathway-related proteins (epithelial NO synthase (eNOS) and inducible NO synthase (iNOS)) were higher in NCG or Arg-supplemented IUGR lambs than those in nontreated IUGR lambs (P < 0.05). The duodenal expressions of the mitophagy-related proteins (microtubule-associated protein light chain 3 (LC3) I, LC3 II, Belin1, PTEN induced putative kinase 1 (PINK1), and Parkin) and the immune function-related proteins (myeloid differentiation factor 88 (MyD88), IL-6, nuclear factor kappa B (p65), toll-like receptor (TLR4) and TNF-alpha) were reduced (P < 0.05) in NCG or Arg-supplemented IUGR lambs compared with non-supplemented IUGR lambs. These results demonstrated that the dietary supplementation of Arg or NCG enhanced the duodenal barrier function and mitochondrial function, mitigated duodenal inflammation, and suppressed mitophagy in suckling lambs suffering from IUGR.
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    L-Arginine Alleviates Hydrogen Peroxide-Induced Oxidative Damage in Ovine Intestinal Epithelial Cells by Regulating Apoptosis, Mitochondrial Function, and Autophagy
    (Oxford Univ Press, 2021) Zhang, Hao; Liu, Xiaoyun; Fan, Yaotian; Yu, Yin; Loor, Juan J.; Elsabagh, Mabrouk; Peng, Along
    Background: Previous studies demonstrated that dietary L-arginine (Arg) alters the equilibrium between reactive oxygen species (ROS) generation and biological defenses to resist oxidant-induced toxicity. Whether supplying Arg can protect ovine intestinal epithelial cells (OIECs) from hydrogen peroxide (H2O2)-induced oxidative damage is unclear. Objectives: The current study aimed to examine the effect of Arg on mitophagy, mitochondrial dysfunction, and apoptosis induced by H2O2 in OIECs. Methods: The OIECs were incubated in Arg-free DMEM supplemented with 100 AM Arg (CON) or 350 AM Arg (ARG) alone or with 150 mu M H2O2 (CON + H2O2, ARG + H2O2) for 24 h. Cellular apoptosis, mitochondrial function, autophagy, and the related categories of genes and proteins were determined. All data were analyzed by ANOVA using the general linear model procedures of SAS (SAS Institute) for a 2 x 2 factorial design. Results: Relative to the CON and ARG groups, H2O2 administration resulted in 44.9% and 26.5% lower (P < 0.05) cell viability but 34.7% and 61.8% greater (P < 0.05) ROS concentration in OIECs, respectively. Compared with the CON and CON + H2O2 groups, Arg supplementation led to 40.7% and 28.8% lower (P < 0.05) ROS concentration but 14.9%-49.0% and 29.3%-64.1% greater (P < 0.05) mitochondrial membrane potential, relative mitochondrial DNA content, and complex (I-IV) activity in OIECs, respectively. Compared with the CON and CON + H2O2 groups, Arg supplementation led to 33.9%-53.1% and 22.4%-49.1 % lower (P < 0.05) mRNA abundance of proapoptotic genes, respectively. Relative to the CON and CON + H2O2 groups, Arg supplementation resulted in 33.0%-59.2% and 14.6%-37.7% lower (P< 0.05) abundance of proapoptotic, mitophagy, and cytoplasmic cytochrome c protein, respectively. Conclusions: Supply of Arg protects OIECs against H2O2-induced damage partly by improving mitochondrial function and alleviating cellular apoptosis and autophagy.
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    L-Arginine Inhibits Apoptosis of Ovine Intestinal Epithelial Cells through the L-Arginine-Nitric Oxide Pathway
    (Oxford Univ Press, 2020) Zhang, Hao; Zhao, Fangfang; Peng, Along; Guo, Shuang; Wang, Mengzhi; Elsabagh, Mabrouk; Loor, Juan J.
    Background: In nonruminants, many of the biological roles of L-arginine (Arg) at the intestinal level are mediated through the Arg-nitric oxide (Arg-NO) pathway. Whether the Arg-NO pathway is involved in controlling the immune response and viability in ovine intestinal epithelial cells (IOECs) is unclear. Objectives: The current study aimed to examine the role of the Arg-NO pathway in apoptosis, antioxidant capacity, and mitochondrial function of IOECs. Methods: The IOECs were incubated in Arg-free DMEM supplemented with 150 mu M Arg (CON) or 300 mu M Arg (ARG) alone or with 350 mu M Nw-nitro-L-arginine methyl ester hydrochloride (L-NAME) (CON + NAME, ARG + NAME) for 24 h. The reactive oxygen species (ROS) concentration, antioxidant capacity, and cell apoptotic percentage were determined. Results: Arg supplementation decreased (P < 0.05) the ROS concentration (38.9% and 22.7%) and apoptotic cell percentage (57.2% and 54.8%) relative to the CON and CON + NAME groups, respectively. Relative to the CON and ARG treatments, the L-NAME administration decreased (P < 0.05) the mRNA abundance of superoxide dismutase 2 (32% and 21.3%, respectively) and epithelial NO synthase (36% and 29.1%, respectively). Arg supplementation decreased (P < 0.05) the protein abundance of apoptosis antigen 1 (FAS) (52.0% and 43.9%) but increased (P < 0.05) those of nuclear respiratory factor 1 (31.3% and 22.9%) and inducible NO synthase (35.2% and 41.8%) relative to the CON and CON + NAME groups, respectively. Conclusions: The inhibition of apoptosis in IOECs due to the increased supply of Arg is associated with the mitochondria- and FAS-dependent pathways through the activity of the Arg-NO pathway. The findings help elucidate the role of the Arg-NO pathway in IOEC growth and apoptosis.