Byung-Chul Park

Effects of dietary supplementation of lipid-encapsulated zinc oxide on colibacillosis, growth and intestinal morphology in weaned piglets challenged with enterotoxigenic Escherichia coli

This study was aimed to evaluate the effect of dietary supplementation of lipid-encapsulated (coated) zinc oxide ZnO on post-weaning diarrhea (colibacillosis) in weaned piglets challenged with enterotoxigenic Escherichia coli (ETEC). Thirty-two 35-day-old weaned piglets were orally challenged with 3 × 10(10) colony forming units of ETEC K88 while eight piglets received no challenge (control). Each eight challenged piglets received a diet containing 100 ppm ZnO (low ZnO), 2500 ppm ZnO (high ZnO) or 100 ppm of lipid (10%)-coated ZnO (coated ZnO) for 7 days; control pigs received the low ZnO diet. Daily gain, goblet cell density in the villi of the duodenum, jejunum and ileum, and villus height in the jejunum and ileum, which decreased due to the challenge, were equally greater in the coated ZnO and high ZnO groups versus low ZnO group. Fecal consistency score, serum interleukin-8 concentration, subjective score of fecal E. coli shedding, and digesta pH in the stomach, jejunum and ileum, which increased due to the challenge, were equally low in the coated ZnO and high ZnO groups versus low ZnO. Results suggest that a low level of coated ZnO might well substitute for a pharmacological level of native ZnO in dietary supplementation to alleviate colibacillosis of weaned piglets.

Barrier protection via Toll-like receptor 2 signaling in porcine intestinal epithelial cells damaged by deoxynivalnol

Intestinal barrier is the first line of defense inside the body and comprises intercellular tight junction (TJ) proteins that regulate paracellular permeability. Deoxynivalenol (DON), a fungal metabolite often found in the contaminated food of domestic animals, is known to impair intestinal barrier function and may be involved in intestinal inflammation. Unlike in humans and mice, the importance of Toll-like receptor (TLR) 2 expressed in porcine intestinal epithelial cells is largely unclear. Therefore, the aim of the present study was to investigate whether TLR2 stimulation enhances intestinal barrier function and protects against DON exposure. We found that the cells treated with TLR2 ligands decreased the epithelial barrier permeability and enhanced TJ protein expression in intestinal porcine epithelial cells (IPEC-J2). In addition, pretreatment with TLR2 ligand, including Pam3CSK4 (PCSK) and lipoteichoic acid from Bacillus subtilis, prevented DON-induced barrier dysfunction by increasing the expression of TJ proteins via the PI3K-Akt-dependent pathway. It is likely that the DON-disrupted intestinal barrier caused biological changes of immune cells in the lamina propria. Thus, we conducted co-culture of differentiated IPEC-J2 cells in the upper well together with peripheral blood mononuclear cells in the bottom well and found that apical TLR2 stimulation of IPEC-J2 cells could alleviate the reduction in cell survival and proliferation of immune cells. Conclusively, TLR2 signaling on intestinal epithelial cells may enhance intestinal barrier function and prevent DON-induced barrier dysfunction of epithelial cells.

Effects of Dietary Energy Level on Growth Efficiency and Carcass Quality Traits of Finishing Pigs

ABSTRACT A total of 96 non-lean-type (Yorkshire ×Landrace) × Duroc gilts and barrows weighing approximately 80 kg were randomly allocated to 24 pens under a 2 (sex) × 3 [diet; 3.4, 3.2, and 3.0 Mcal DE/kg {‘high’-, ‘medium’-, and ‘low’-energy diets (HE, ME, and LE), respectively}] factorial arrangement of treatments. All animals were slaughtered approximately at 115 kg, after which carcass quality traits and grades and physicochemical and sensory characteristics of the loin related to meat quality were analyzed. The ADG and gain:feed were not affected by the sex or dietary treatment, whereas ADFI was greater in the ME vs HE group. Backfat thickness was greater in barrows vs gilts and also in ME and HE vs LE only in barrows. Enumerated carcass marbling and quality grade, which were highly correlated (r=0.56; P<0.01), were greater in barrows vs gilts. Physicochemical characteristics including the color, pH, drip loss and contents of moisture, protein, and fat of fresh loin, as well as sensory characteristics of fresh and cooked loin, were not affected by the sex or dietary treatment, except for shear force for cooked loin which was greater (P<0.05) in LE and ME vs HE. In conclusion, it is thought that ME is comparable to HE in terms of the effect on growth and carcass quality of finishing pigs, but that the relative effect of LE vs ME needs to be further studied. (

Ginsenoside Re enhances survival of human CD4+ T cells through regulation of autophagy.

In the present study, we examined the effects of ginsenoside Re (Re) on cytokine expression, cytokine-dependent autophagy and cell survival in human CD4(+) T cells. When CD4(+) T cells isolated from human peripheral blood were treated with Re, LC3 and monodansylcadaverine (MDC), representative markers of autophagy, were decreased in a dose-dependent manner. Interestingly, Re suppressed the production of interferon-gamma (IFN-gamma) and immunity-related GTPase family M (IRGM) in CD4(+) T cells whereas no changes in other autophagy-related signaling molecules (ERK, p38 and AKT-mTOR-p70S6k) were found. Concomitantly, we observed that Re increased the proliferation of CD4(+) T cells with decreased cell death. Our results demonstrate that ginsenoside Re enhanced viability of CD4(+) T cells through the regulation of IFN-gamma-dependent autophagy activity.

Relationships of Muscle Fiber Characteristics to Dietary Energy Density, Slaughter Weight, and Muscle Quality Traits in Finishing Pigs

The present study was conducted to investigate the relationships of muscle fiber characteristics to dietary energy density (3.0 (Low-E) vs. 3.2 (Med-E) Mcal DE/kg)) and slaughter weight (SW; 110, 125, and 138 kg) in finishing pigs (gilt vs. barrow) using a 2×3×2 factorial treatment design. Forty-one longissimus dorsi muscle (LM) samples were analyzed histochemically, with growth performance and physicochemical data for the 41 animals and their LM out of 192 animals and 72 LM used in a previous study retrospectively included. The ADG was less (P<0.01) in the Low-E than in the Med-E group (0.93 vs. 0.73 kg) whereas lightness (L*) and redness (a*) of LM were greater in the Low-E group SW did not influence these variables. The diameter and perimeter of the type I (slow-oxidative), type IIA (fast oxido-glycolytic) and type IIB (fast glycolytic) fibers increased with increasing SW whereas densities of the fibers decreased. However, the number and area percentages of the fiber types were not influenced by SW or dietary energy density. The percentage and per-mm 2 density of type IIB fibers were negatively correlated with SW (r =-0.33 and -0.57, with P<0.05 and <0.01, respectively), whereas type I fiber number percentage was positively correlated with SW (r = 0.31; P<0.05). Marbling score was negatively correlated (P<0.05) with type I (r =-0.36) and type IIB (r =-0.39) fiber densities. The a* was correlated (P<0.01) with both type I and type IIB fiber number percentages in the opposite way (r = 0.42 and -0.47, respectively). However, L* (lightness), drip loss and pH24h were not correlated with the fiber number percentage or density of any fiber type. Collectively, results indicate that muscle fibers grow by hypertrophy during the late finishing period, but that fiber characteristics other than the size are not significantly influenced by dietary energy density or SW.

Effects of dietary supplementation of lipid-coated zinc oxide on intestinal mucosal morphology and expression of the genes associated with growth and immune function in weanling pigs

Objective The present study was conducted to investigate the effects of a lipid-coated zinc oxide (ZnO) supplement Shield Zn (SZ) at the sub-pharmacological concentration on intestinal morphology and gene expression in weanling pigs, with an aim to gain insights into the mechanism of actions for SZ. Methods Forty 22-day-old weanling pigs were fed a nursery diet supplemented with 100 or 2,500 mg Zn/kg with uncoated ZnO (negative control [NC] or positive control [PC], respectively), 100, 200, or 400 mg Zn/kg with SZ for 14 days and their intestinal tissues were taken for histological and molecular biological examinations. The villus height (VH) and crypt depth (CD) of the intestinal mucosa were measured microscopically following preparation of the tissue specimen; expression of the genes associated with growth and immune function was determined using the real-time quantitative polymerase chain reaction. Results There was no difference in daily gain, gain:feed, and diarrhea score between the SZ group and either of NC and PC. The VH and VH:CD ratio were less for the SZ group vs NC in the jejunum and duodenum, respectively (p<0.05). The jejunal mucosal mRNA levels of insulin-like growth factor (IGF-I) and interleukin (IL)-10 regressed and tended to regress (p = 0.053) on the SZ concentration with a positive coefficient, respectively, whereas the IL-6 mRNA level regressed on the SZ concentration with a negative coefficient. The mRNA levels of IGF-I, zonula occludens protein-1, tumor necrosis factor-α, IL-6, and IL-10 did not differ between the SZ group and either of NC and PC; the occludin and transforming growth factor-β1 mRNA levels were lower for the SZ group than for PC. Conclusion The present results are interpreted to suggest that dietary ZnO provided by SZ may play a role in intestinal mucosal growth and immune function by modulating the expression of IGF-I, IL-6, and IL-10 genes.

Myotube differentiation in clustered regularly interspaced short palindromic repeat/Cas9-mediated MyoD knockout quail myoblast cells

Objective In the livestock industry, the regulatory mechanisms of muscle proliferation and differentiation can be applied to improve traits such as growth and meat production. We investigated the regulatory pathway of MyoD and its role in muscle differentiation in quail myoblast cells. Methods The MyoD gene was mutated by the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 technology and single cell-derived MyoD mutant sublines were identified to investigate the global regulatory mechanism responsible for muscle differentiation. Results The mutation efficiency was 73.3% in the mixed population, and from this population we were able to establish two QM7 MyoD knockout subline (MyoD KO QM7#4) through single cell pick-up and expansion. In the undifferentiated condition, paired box 7 expression in MyoD KO QM7#4 cells was not significantly different from regular QM7 (rQM7) cells. During differentiation, however, myotube formation was dramatically repressed in MyoD KO QM7#4 cells. Moreover, myogenic differentiation-specific transcripts and proteins were not expressed in MyoD KO QM7#4 cells even after an extended differentiation period. These results indicate that MyoD is critical for muscle differentiation. Furthermore, we analyzed the global regulatory interactions by RNA sequencing during muscle differentiation. Conclusion With CRISPR/Cas9-mediated genomic editing, single cell-derived sublines with a specific knockout gene can be adapted to various aspects of basic research as well as in functional genomics studies.

Effects of milk replacer and starter diet provided as creep feed for suckling pigs on pre‐ and post‐weaning growth

This study was aimed at investigating the long-term effects of provision of liquid milk replacer (MR) and solid starter diet (SD) during lactation on post-weaning (PW) growth of pigs. In experiment 1, 33 cross-bred litters were allotted to four treatments: no supplement (CON), MR ad libitum, SD ad libitum and 100 g SD/litter/day from lactation day 4 through weaning at day 21 during late fall. In experiment 2, 40 litters received MR or none in July. PW pigs received commercial diets to marketing. In experiment 1, weaning weight (WW), pre-weaning average daily gain (ADG) and mortality (2.4%) were not influenced by creep-feeding MR or SD. ADG was greater (P < 0.05) in the MR group versus CON during days 21-54, but did not differ across the treatments during days 54-162. In experiment 2, ADG during lactation and WW were greater in the MR group versus CON, with mortality lower in the former (5.6 vs. 10.3%). However, PW ADG to day 175 did not differ between the two groups. Results suggest that creep-feeding MR or SD has no effect on PW growth. However, it remains possible that MR reduces PW mortality during the hot season.

Regulation of CD4 + CD8 − CD25 + and CD4 + CD8 + CD25 + T cells by gut microbiota in chicken

The gut microbiota in chicken has long been studied, mostly from the perspective of growth performance. However, there are some immunological studies regarding gut homeostasis in chicken. Although CD4+CD25+ T cells are reported to act as regulatory T cells (Tregs) in chicken, there have been no studies showing the relationship between gut microbiota and Tregs. Therefore, we established a model for ‘antibiotics (ABX)-treated chickens’ through administration of an antibiotic cocktail consisting of ampicillin, gentamycin, neomycin, metronidazole, and vancomycin in water for 7 days. CD4+CD8−CD25+ and CD4+CD8+CD25+ T cells in cecal tonsils were significantly decreased in this model. Gram-positive bacteria, especially Clostridia, was responsible for the changes in CD4+CD8−CD25+ or CD4+CD8+CD25+ T cells in cecal tonsils. Feeding ABX-treated chickens with acetate recovered CD4+CD8−CD25+ and CD4+CD8+CD25+ T cells in cecal tonsils. GPR43, a receptor for acetate, was highly expressed in CD4+CD8−CD25+ T cells. In conclusion, our study demonstrated that the gut microbiota can regulate the population of CD4+CD8−CD25+ and CD4+CD8+CD25+ T cells, and that acetate is responsible for the induction of CD4+CD8−CD25+ T cells in cecal tonsils via GPR43.

Distinct pattern of immune tolerance in dendritic cells treated with lipopolysaccharide or lipoteichoic acid

HighlightsRepeated LTA stimulation suppressed TNF‐&agr; and IL‐6 production in BMDCs.BMDCs treated with repeated LTA down‐regulated IL‐10 and enhanced LAP.BMDCs treated with LTA showed sustained expression of TOLLIP and IDO.LPS exposure to BMDCs induced cross tolerance to LTA while LTA did not to LPS. &NA; Cytokine induction is often critical for the host defense during acute immune responses while, if not tightly regulated, it may cause an immunological pathology coincident with tissue damage. Despite the fact that gram‐positive bacterial infection has become increasingly prevalent, immune modulation induced by lipoteichoic acid (LTA), the major cell wall component of gram‐positive bacteria has not been studied thoroughly at the cellular level. In the current study, tolerance induction in mouse bone marrow‐derived dendritic cells (BMDCs) treated with single or repeated stimulation of Staphylococcus aureus LTA was compared with those of Escherichia coli lipopolysaccharide (LPS). The results showed that repeated LTA stimulation significantly suppressed pro‐inflammatory cytokine (TNF‐&agr; and IL‐6) production in BMDCs, comparable to that of LPS, but with less extent, down‐regulated IL‐10 and enhanced the inhibitory molecule, LAG‐3‐associated protein (LAP). Furthermore, we observed a sustained expression of unique negative regulators, Toll interacting protein (TOLLIP) and Indoleamine 2,3‐dioxygenase (IDO), in BMDCs treated with LTA. A transient hyporesponsiveness period appeared when DCs were treated repeatedly with LTA or LPS showing a distinctive pattern. Intriguingly, LPS exposure induced cross tolerance to LTA while LTA exposure did not to LPS, implicating that a distinct signaling components are involved in response to LTA. Collectively, a distinct immune regulation appeared to be responsible for the LPS‐ and LTA‐induced tolerance on cytokine production, expression of surface markers and intracellular proteins.