Caimei Wu

Effects of spermine on the morphology, digestive enzyme activities, and antioxidant status of jejunum in suckling rats

Spermine is a ubiquitous cellular component that plays vital roles in the maintenance of nucleic acids, regulation of kinase activities, protein synthesis, control of ion channel activities and renewal of the gut epithelium. However, knowledge of the effects of spermine supplementation and its duration extension on intestinal growth and antioxidant capacity is lacking. The present work aims to investigate the effects of spermine administration and its extended supplementation on the morphology, digestive enzyme activities, and antioxidant status of the jejunum in suckling rats. The rats received 0.2 μmol g−1 body weight of either spermine or saline solution via intragastric ingestion for 3 or 7 d, and jejunum samples obtained 24 h after the last spermine supplementation were analyzed. The results demonstrated that the specific activity of maltase and the total antioxidant capacity (T-AOC) in rat jejunum were significantly increased by 105.5% and 11.1%, respectively; in contrast, lactase activity was significantly decreased by 34.8% (spermine group versus the control group). Time extension of spermine administration (7 d) significantly increased the villus height, villus width, surface area, and crypt depth in rat jejunum by 11.2%, 18.2%, 5.9%, and 50%, respectively, but significantly decreased the specific activities of lactase, maltase, alkaline phosphatase, and malondialdehyde content by 26.8%, 36.4%, 41.3%, and 26.0% (P < 0.05), respectively. Protein content, sucrase, catalase, T-SOD, and anti-superoxide anion activities were also increased by 23.1%, 424.2%, 45.7%, 11.7%, and 26.4% (P < 0.05), respectively, relative to the levels observed during spermine administration for 3 d. Taken together, the results suggest that spermine administration and extension of its supplementation duration can accelerate gut development and enhance antioxidant properties.

Spermine: new insights into the intestinal development and serum antioxidant status of suckling piglets

The present work aimed at investigating the effects of spermine supplementation and extended spermine administration on the intestinal morphology, enzyme activity, and serum antioxidant capacity of suckling piglets. Eighty piglets were randomly assigned to two groups, i.e., those with adequate nutrient intake supplemented with spermine (0.4 mmol kg−1 body weight) or those with restricted nutrient intake supplemented with saline. The piglets were fed in pairs for 7 h or 3, 6, or 9 days. The results of analysis are as follows: (1) the villus height, villus width, villus : crypt ratio, and villus surface area in the jejunum of spermine-treated piglets significantly increased by 17.39%, 21.56%, 45.22%, and 45.45%, respectively, compared with those of the control. The specific activities of sucrase, maltase, and diamine oxidase in this organ also significantly increased by 34.55%, 12.77%, and 10.00%, respectively, but lactase activity decreased by 22.56% (spermine group vs. the control group). Extended spermine administration significantly increased jejunal development. (2) Compared with those of the control group, the ileum of the piglets in the spermine group showed significant increases in villus height, villus width, villus : crypt ratio, and villus surface area of 25.64%, 21.61%, 61.05%, and 52.94%, respectively. The specific activities of sucrase, alkaline phosphatase, and diamine oxidase in this organ significantly increased by 24.36%, 5.56%, and 20.23%, respectively, but lactase activity decreased by 39.08%. Extended spermine administration also significantly enhanced ileal development. (3) Compared with the control piglets, spermine promoted increases in catalase (CAT), total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), and anti-superoxide anion (ASA) activities and glutathione (GSH) content (by 23.19%, 30.63%, 5.64%, 10.31%, and 33.70%, respectively, P < 0.05), as well as decreases in malondialdehyde (MDA) activity (by 23.01%; P < 0.05) in piglet serum. Extended spermine administration significantly enhanced antioxidant capacity of serum. Collectively, these results suggest that spermine ingestion and extended spermine supplementation can accelerate gut maturation and enhance the antioxidant status of piglets.

Biological System Responses to Zearalenone Mycotoxin Exposure by Integrated Metabolomic Studies

This study aims to investigate the effect of zearalenone supplementation on rat metabolism. Rats received biweekly intragastric administration of zearalenone mycotoxin (3 mg/kg body weight) for 2 weeks. Urine and plasma samples after zearalenone administration were analyzed by NMR-based metabolomics. Zearalenone exposure significantly elevated the plasma levels of glucose, lactate, N-acetyl glycoprotein, O-acetyl glycoprotein, and propionate but reduced the plasma levels of tyrosine, branched-chain amino acids, and choline metabolites. Zearalenone supplementation decreased the urine levels of butyrate, lactate, and nicotinate. However, it increased the urine levels of allantoin, choline, and N-methylnicotinamide at 0-8 h after the last zearalenone administration and those of 1-methylhistidine, acetoacetate, acetone, and indoxyl sulfate at 8-24 h after the last zearalenone administration. These results suggest that zearalenone exposure can cause oxidative stress and change common systemic metabolic processes, including cell membrane metabolism, protein biosynthesis, glycolysis, and gut microbiota metabolism.

Systemic responses of weaned rats to spermine against oxidative stress revealed by a metabolomic strategy

Many factors can induce oxidative stress in livestock production. Such stress results in damage to cellular antioxidant defense, suboptimal livestock health conditions, and decrease in production efficiency. Spermine supplementation is known to have the potential to mitigate the effects of oxidative stress. However, the systematic changes in metabolic biochemistry associated with oxidative stress and spermine intervention remain largely unknown. This study aims to investigate the effects of oxidative stress and spermine supplementation on the metabolism of weaned rats. Rats received intragastric administration of either 0.4 μmol g−1 body weight of spermine or saline solution for 3 days. The rats in each treatment were then intraperitoneally injected with diquat at 12 mg kg−1 body weight or sterile solution. The 24 h urine and 48 h plasma samples after the last spermine ingestion were analyzed by using nuclear magnetic resonance-based metabolomics. Spermine supplementation and diquat injection can change common systemic metabolic processes, including lipid metabolism, glucose and energy metabolism, amino acid metabolism, as well as gut microbiota functions. Moreover, diquat can induce oxidative stress and alter bile acid metabolism. Under oxidative stress, spermine supplementation could partially counteract the metabolite changes induced by oxidative stress, including amino acid metabolism and lipid metabolism. This study demonstrates the importance of spermine supplementation in regulating the metabolism of weaned rats.

Nutrimetabolomic analysis provides new insights into spermine-induced ileum-system alterations for suckling rats

This study aimed to investigate the effects of spermine supplementation on the ileum metabolism of suckling rats. Rats were intragastrically administered with 0.2 μmol g−1 body weight of either spermine or saline for 3 or 7 days. The ileum samples taken 24 h after the last spermine ingestion were analyzed by NMR-based metabolomics. The results showed that the villus width, surface area, and crypt depth of the rat ileum were increased by 18.0%, 33.3%, 15.7%, respectively, and the specific activities of sucrase and maltase in the rat ileum were also significantly increased by 789.4%, 44.9%, respectively, but the activity of lactase and alkaline phosphatase were decreased by 49.9%, 35.5%, respectively (spermine group relative to control group) and the villus width, surface area, and crypt depth of the rat ileum were increased by 15.1%, 33.3%, 26.3%, respectively [duration extension of spermine (7 days) relative to 3 days] (P < 0.05). Spermine also increased ileum choline, amino acids, inosine, lactate, myo-inositol, scyllo-inositol, and trimethylamine-N-oxide levels and decreased the level of lysine (P < 0.05). The ileum levels of α-glucose, aspartate, creatine, D-galactose, formate, glutathione, glycerolphosphocholine, lipid, and tyrosine were also significantly affected by spermine supplementation (P < 0.05). Collectively, spermine ingestion induces the morphological and common systemic metabolic modifications characterizing the ileum postnatal maturation suggesting the important role of spermine. The metabolic variations could be attributed to functional variations in lipid metabolism, energy metabolism, amino acid metabolism, gut microbial activity, osmoregulation, and oxidative protection.

Molecular Cloning, Tissue Distribution, and Functional Analysis of Porcine Akirin2

Akirin2 is a recently discovered gene that is involved in innate immune response. In this study, the porcine Akirin2 gene was cloned. The full-length coding sequence (CDS) of porcine Akirin2 consists of 612 bp and encodes 203 amino acids with a molecular mass of 22493 kD. The homology tree analysis showed that the pig Akirin2 has closer genetic relationships and distance with the known mammalian Akirin2. Real time quantitative PCR analysis showed that the porcine Akirin2 transcript was most abundant in the lung, followed by the skeletal muscle, heart, liver, fat, thymus, lymph node, small intestine, kidney, and spleen. Overexpression of porcine Akirin2 increased expression of IL-6 in porcine jejunal epithelial cell line IPEC-J2 cells. Our data suggest that porcine Akirin2 could play an important role in intestinal immune regulation.

NMR-based metabolomic studies reveal changes in biochemical profile of urine and plasma from rats fed with sweet potato fiber or sweet potato residue

Dietary fiber has attracted more interest in recent years because many studies have uncovered its disease preventive and health-promoting features: containing blood cholesterol and/or glucose attenuation and reducing obesity risk. However, the health effects of sweet potato fiber (SF) and sweet potato residue (SR) and the knowledge of their exact mechanisms of action are still not fully understood. This study investigates the effect of SF and SR administration on rat metabolism. Rats were randomly assigned to one of three dietary groups of 11 rats each and given a basal diet containing 15% SF, 15% SR, or no supplemental fiber (control). The groups were observed for 30 days, and urine and plasma samples were analyzed by proton nuclear magnetic resonance. Compared with the rats in the control group, those administered the diet containing SF exhibited significantly increased plasma levels of lipid, lactate, and myo-inositol, as well as urine levels of acetate, citrulline, N-acetylglutamate, and p-hydroxyphenylacetate. SF significantly decreased the plasma levels of glutamine, glutamine/glutamate, lysine, phosphorylcholine/glycerolphosphocholine, tyrosine, and glucose, as well as the urine level of allantoin. Moreover, SR significantly increased the plasma levels of acetone, lipid, and lactate, as well as the urine levels of acetamide, alanine, citrulline, ethanol, lactate, methylamine, methylmalonate, N-acetylglutamate, and α-hydroxybutyrate, compared with the control group. SR significantly decreased the plasma levels of citrate, glutamate, glutamine, isoleucine, lysine, methionine, and glucose, as well as the urine level of isobutyrate. These results suggest that SF and SR supplementation have certain systemic metabolic processes in common, including lipid metabolism, glycogenolysis and glycolysis metabolism, energy metabolism, protein biosynthesis, and gut microbiota metabolism. This study demonstrates the potential for the routine use of metabolomics in nutritional studies to characterize metabolic effects and understand the influence of diet on animal metabotypes.

Pea fiber and wheat bran fiber show distinct metabolic profiles in rats as investigated by a 1H NMR-based metabolomic approach.

This study aimed to examine the effect of pea fiber (PF) and wheat bran fiber (WF) supplementation in rat metabolism. Rats were assigned randomly to one of three dietary groups and were given a basal diet containing 15% PF, 15% WF, or no supplemental fiber. Urine and plasma samples were analyzed by NMR-based metabolomics. PF significantly increased the plasma levels of 3-hydroxybutyrate, and myo-inositol as well as the urine levels of alanine, hydroxyphenylacetate, phenylacetyglycine, and α-ketoglutarate. However, PF significantly decreased the plasma levels of isoleucine, leucine, lactate, and pyruvate as well as the urine levels of allantoin, bile acids, and trigonelline. WF significantly increased the plasma levels of acetone, isobutyrate, lactate, myo-inositol, and lipids as well as the urine levels of alanine, lactate, dimethylglycine, N-methylniconamide, and α-ketoglutarate. However, WF significantly decreased the plasma levels of amino acids, and glucose as well as the urine levels of acetate, allantoin, citrate, creatine, hippurate, hydroxyphenylacetate, and trigonelline. Results suggest that PF and WF exposure can promote antioxidant activity and can exhibit common systemic metabolic changes, including lipid metabolism, energy metabolism, glycogenolysis and glycolysis metabolism, protein biosynthesis, and gut microbiota metabolism. PF can also decrease bile acid metabolism. These findings indicate that different fiber diet may cause differences in the biofluid profile in rats.

Arginine, N-carbamylglutamate, and glutamine exert protective effects against oxidative stress in rat intestine

The objective of the current study is to evaluate the effects of dietary supplementation with arginine (ARG), N-carbamylglutamate (NCG), and glutamine (GLN) on rat intestinal morphology and antioxidant status under oxidative stress. Rats were fed for 30 d with one of the following iso-nitrogenous diets: basal diet (BD), BD plus 1% ARG, BD plus 0.1% NCG, and BD plus 1% GLN. On day 28, half of the rats fed BD were intraperitoneally injected with 12 mg/kg body weight of diquat (DT; i.e., the DT group) and the other half was intraperitoneally injected with sterile solution (i.e., the control group). The other diet groups were intraperitoneally injected with 12 mg/kg body weight of DT (i.e., DT + 1% GLN [DT + GLN], DT + 1% ARG [DT + ARG], and DT + 0.1% NCG [DT + NCG]). Rat jejunum samples obtained at 48 h after DT injection were analyzed. Results showed that DT significantly decreased catalase (CAT) activity and glutathione (GSH) content by 58.25% and 56.57%, respectively, and elevated malondialdehyde (MDA) content and crypt depth (CD) by 19.39% and 22.13%, respectively, in the jejunum (P < 0.05, relative to the control group). Compared with the DT group, the DT + GLN group exhibited significantly improved villus height (VH), villus width (VW), villus surface area (VSA), CD and total antioxidant capacity (T-AOC) activity (P < 0.05); the DT + ARG group exhibited significantly increased the ratio of VH to CD (H:D) and T-AOC activity (P < 0.05); the DT + GLN, DT + ARG and DT + NCG groups exhibited significantly enhanced CAT activity and GSH content as well as decreased MDA content (P < 0.05). Moreover, VH, VW, VSA, CD and GSH content in the DT + GLN group were higher whereas MDA content was lower compared with the corresponding values observed in both the DT + ARG and the DT + NCG groups (P < 0.05). The H:D ratio in the DT + ARG group significantly increased compared with that in the DT + NCG and DT + GLN groups (P < 0.05). Collectively, this study suggested that dietary supplementation with 1% GLN, 0.1% NCG, and 1% ARG was effective in enhancing the antioxidant status and maintaining the morphological structure of rat jejunum under oxidative stress; of these supplements, 1% GLN exerted the greatest effects on mitigating oxidative stress.

Differences in plasma metabolomics between sows fed dl -methionine and its hydroxy analogue reveal a strong association of milk composition and neonatal growth with maternal methionine nutrition

The aim of the present study was to determine whether increased consumption of methionine as DL-methionine (DLM) or its hydroxy analogue DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA) could benefit milk synthesis and neonatal growth. For this purpose, eighteen cross-bred (Landrace × Yorkshire) primiparous sows were fed a control (CON), DLM or HMTBA diet (n 6 per diet) from 0 to 14 d post-partum. At postnatal day 14, piglets in the HMTBA group had higher body weight (P= 0·02) than those in the CON group, tended (P= 0·07) to be higher than those in the DLM group, and had higher (P< 0·05) mRNA abundance of jejunal fatty acid-binding protein 2, intestinal than those in the CON and DLM groups. Compared with the CON diet-fed sows, milk protein, non-fat solid, and lysine, histidine and ornithine concentrations decreased in the DLM diet-fed sows (P< 0·05), and milk fat, lactose, and cysteine and taurine concentrations increased in the HMTBA diet-fed sows (P< 0·05). Plasma homocysteine and urea N concentrations that averaged across time were increased (P< 0·05) in sows fed the DLM diet compared with those fed the CON diet. Metabolomic results based on ¹H NMR spectroscopy revealed that consumption of the HMTBA and DLM diets increased (P< 0·05) both sow plasma methionine and valine levels; however, consumption of the DLM diet led to lower (P< 0·05) plasma levels of lysine, tyrosine, glucose and acetate and higher (P< 0·05) plasma levels of citrate, lactate, formate, glycerol, myo-inositol and N-acetyl glycoprotein in sows. Collectively, neonatal growth and milk synthesis were regulated by dietary methionine levels and sources, which resulted in marked alterations in amino acid, lipid and glycogen metabolism.