Kang-Sun Park

Effect of Lactobacillus plantarum CJLP243 on the growth performance and cytokine response of weaning pigs challenged with enterotoxigenic Escherichia coli1

The purpose of the present study was to evaluate the effect of diets containing Lactobacillus plantarum CJLP243 on the growth and cytokine response of weaning pigs (Sus scrofa) challenged with enterotoxigenic Escherichia coli (ETEC). In a 28-d experiment (14 d before and 14 d after challenge), a total of 108 pigs at 20 ± 1 d of age were allotted to 1 of 6 diets. These were a control diet without ETEC challenge (CON) and 5 treatment diets with ETEC challenge, including a control diet with ETEC challenge (negative control, NC); a positive control diet containing antibiotics (PC); control diet plus (10(8), 10(9), or 10(10)) cfu/kg L. plantarum CJLP243 (T1, T2, and T3, respectively). After challenge, NC showed the least ADFI, whereas PC and T3 had the greatest ADFI (P = 0.002). The ADG of PC, T2, and T3 were greater (P = 0.001) than that of CON, NC, and T1 during wk 1 to wk 2. During wk 3 to wk 4, a marked decline was seen in NC (P = 0.001) compared with CON, whereas PC and T3 showed increased ADG (P = 0.001). The overall ADG of PC and T3 were greater (P < 0.001) than the remaining groups. The PC and T3 had the greatest G:F during the second 2 wk (P = 0.002), and the overall 4-wk experimental period (P = 0.003). At 3 h after challenge, all groups except CON had greater rectal temperatures (RT; P < 0.05). The RT decreased to prechallenge temperatures at 9 h (PC and T3), 24 h (T1 and T2), and remained increased until d 7 in NC. At 7 and 14 d postinfection, the number of animals detected positive for ETEC by PCR assay was the greatest in NC; however, the PC group had the fewest ETEC-positive animals (P < 0.05), which was similar to T3. All challenged pigs, except T2, had greater concentrations of serum haptoglobin compared with CON, with the greatest concentration observed in NC (P < 0.001). Challenged pigs had increased serum concentrations of tumor necrosis factor alpha (TNF-α) 3 to 48 h postinfection, with the greatest concentration of TNF-α at 48 h observed in NC (P < 0.05). Similarly, greater (P < 0.05) serum concentrations of interferon-γ were observed for 9 h (T1 and T3), 24 h (T2 and PC), and 48 h (NC) postinfection. The serum concentration of IL-6 increased (P < 0.05) for 3 h in T3 and 24 h in NC. In conclusion, our findings suggest that L. plantarum CJLP243, at a concentration of 10(10) cfu/kg, may serve as a potential alternative to antibiotic supplementation to improve the growth and health performance of weaning pigs, especially during acute inflammation of the gut after bacterial infections.

Neuronal cell differentiation of mesenchymal stem cells originating from canine amniotic fluid

The amniotic fluid contains mesenchymal stem cells (MSCs) and can be readily available for tissue engineering. Regenerative treatments such as tissue engineering, cell therapy, and transplantation show potential in clinical trials of degenerative diseases. Disease presentation and clinical responses in the Canis familiaris not only are physiologically similar to human compared with other traditional mammalian models but is also a suitable model for human diseases. The aim of this study was to investigate whether canine amniotic-fluid-derived mesenchymal stem cells (cAF-MSCs) can differentiate into neural precursor cells in vitro when exposed to neural induction reagent. During neural differentiation, cAF-MSCs progressively acquire neuron-like morphology. Messenger RNA (mRNA) expression levels of neural-specific genes, such as NEFL, NSE, and TUBB3 (βIII-tubulin) dramatically increased in the differentiated cAF-MSCs after induction. In addition, protein expression levels of nestin, βIII-tubulin, and tyrosine hydroxylase remarkably increased in differentiated cAF-MSCs. This study demonstrates that cAF-MSCs have great potential for neural precursor differentiation in vitro. Therefore, amniotic fluid may be a suitable alternative source of stem cells and can be applied to cell therapy in neurodegenerative diseases.

Glutathione and cysteine enhance porcine preimplantation embryo development in vitro after intracytoplasmic sperm injection

Because intracytoplasmic sperm injection (ICSI) had been introduced to animal science, not only reproductive biology of domestic animals, but also medicine to treat infertility has been developed. This assisted reproductive technology is beneficial for generating transgenic animals, especially pigs, because polyspermy is the greatest hurdle in porcine IVF when researchers make highly qualified preimplantation embryos. However, ICSI-derived embryos expressed high level of reactive oxygen species (ROS), which are known to cause serious dysfunction during preimplantation development. The objective of this study was to investigate the developmental competence, ROS level, and apoptosis index when glutathione (GSH) or cysteine was supplemented into the in vitro culture medium for ICSI-derived porcine embryos. First, we evaluated the effect of different concentrations of GSH or cysteine on developmental ability of porcine ICSI-derived embryos. The cleavage rate (79.6%) and the blastocyst formation rate (20.9%) were significantly improved in culture medium supplemented with 1 mmol/L GSH compared with other concentrations or no supplementation. Also, 1.71 mmol/L cysteine showed a significantly higher proportion of cleavage (80.7%) and blastocyst formation (22.5%) than other cysteine-supplemented groups. Next, we confirmed that intracellular ROS level was significantly reduced in the group of blastocysts cultured with GSH or cysteine after ICSI compared with the no supplementation group. Finally, we found that terminal uridine nick-end labeling index, fragmentation, and total apoptosis were significantly decreased and the total cell number was significantly increased in blastocysts when ICSI-derived embryos were cultured with supplementation of 1.71 mmol/L cysteine or 1 mmol/L GSH. Taken together, these results strongly indicate that GSH or cysteine can improve the developmental competence of porcine ICSI-derived embryos by reducing intracellular ROS level and the apoptosis index.

Effect of Acteoside as a Cell Protector to Produce a Cloned Dog.

Somatic cell nuclear transfer (SCNT) is a well-known laboratory technique. The principle of the SCNT involves the reprogramming a somatic nucleus by injecting a somatic cell into a recipient oocyte whose nucleus has been removed. Therefore, the nucleus donor cells are considered as a crucial factor in SCNT. Cell cycle synchronization of nucleus donor cells at G0/G1 stage can be induced by contact inhibition or serum starvation. In this study, acteoside, a phenylpropanoid glycoside compound, was investigated to determine whether it is applicable for inducing cell cycle synchronization, cytoprotection, and improving SCNT efficiency in canine fetal fibroblasts. Primary canine fetal fibroblasts were treated with acteoside (10, 30, 50 μM) for various time periods (24, 48 and 72 hours). Cell cycle synchronization at G0/G1 stage did not differ significantly with the method of induction: acteoside treatment, contact inhibition or serum starvation. However, of these three treatments, serum starvation resulted in significantly increased level of reactive oxygen species (ROS) (99.5 ± 0.3%) and apoptosis. The results also revealed that acteoside reduced ROS and apoptosis processes including necrosis in canine fetal fibroblasts, and improved the cell survival. Canine fetal fibroblasts treated with acteoside were successfully arrested at the G0/G1 stage. Moreover, the reconstructed embryos using nucleus donor cells treated with acteoside produced a healthy cloned dog, but not the embryos produced using nucleus donor cells subjected to contact inhibition. In conclusion, acteoside induced cell cycle synchronization of nucleus donor cells would be an alternative method to improve the efficiency of canine SCNT because of its cytoprotective effects.

Follistatin Rescues Blastocyst Development of Poor Quality Porcine Cumulus–Oocyte Complexes by Delaying Meiotic Resumption With Decreased cGMP

Mammalian oocytes resume maturation when removed from follicles and cultured in vitro. During folliculogenesis, oocytes are bathed in follicular fluid (FF), which provides an important and specialized microenvironment for oocyte competence. Follistatin (FST) is one component of FF that may play a role in oocyte maturation and embryo development. This study was conducted to examine possible effects of FST on porcine oocyte competence and embryo development. Exogenous FST in oocyte maturation medium for 22 or 44 hours did not improve nuclear maturation and had no effect on good quality cumulus–oocyte complexes (COCs). However, FST improved blastocyst rates in embryos derived from oocytes with less than 2 layers of cumulus. Follistatin treatment of the poor quality COC group increased transcript levels for genes indicative of oocyte quality. Transcript levels were also altered for cumulus expansion–related genes in response to FST when measured during the germinal vesicle breakdown stage. Interestingly, high-quality oocytes remained at germinal vesicle stage much longer than low-quality oocytes, FST treatment induced temporary blockage of spontaneous meiotic resumption when added during culture of both good and poor quality COCs, and levels of cyclic guanosine monophosphate (cGMP) were higher in FST-treated versus untreated groups for both good and poor quality oocytes. In conclusion, FST treatment of porcine oocytes during in vitro maturation can rescue competency of poor quality oocytes to develop to blastocyst stage following in vitro fertilization. Beneficial effects of addition of FST to culture medium may be mediated by inhibiting degradation of cGMP and temporarily delaying nuclear maturation.

WITHDRAWN: Effects of various glycerol concentrations and thawing temperatures on CASA parameters and acrosomal integrity of frozen–thawed canine spermatozoa

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.