Zixu Wang

Effects of Monochromatic Light on Immune Response of Broilers

A total of 260 one-day-old Arbor Acres male broilers were exposed to red light (RL), green light (GL), blue light (BL), and white light (WL), respectively, by using a light-emitting diode system for 7 wk. There were 5 replicate pens for each light treatment and 13 birds per pen. The effects of monochromatic light on the immune response were studied. The results indicated that proliferation of peripheral blood T lymphocytes in the GL group was significantly increased (by 80.8 and 54.8%) compared with those in the RL and BL groups, respectively, at 21 d of age (P < 0.05). At 49 d of age, however, the proliferation response was significantly increased in the BL group compared with the RL group (26.9%, P< 0.05). Moreover, the GL group showed a significant elevation in the serum anti-Newcastle disease virus level as compared with that of the RL group at 28 d of age (32.9%, P < 0.05). In contrast, no significant difference in serum anti-Newcastle disease virus level was observed among the BL, RL, and WL groups at this age (P > 0.05). By 49 d of age, the antibody titer was higher in the BL group than in the RL group (62.8%, P < 0.05). However, no significant difference in antibody titer was seen among the BL, GL, and WL groups at this age. Interestingly, the BL group showed a 44.0% reduction in the level of serum interleukin-1beta as compared with that in the RL group at 49 d of age (P < 0.05). These results suggest that GL and BL enhance the immune response better than RL, and that BL may play a role in alleviating the stress response in broilers.

Oncogenic E17K mutation in the pleckstrin homology domain of AKT1 promotes v-Abl-mediated pre-B-cell transformation and survival of Pim-deficient cells

Abl-mediated transformation requires the activation of multiple pathways involved in the cellular proliferation and survival, including PI3K/AKT and JAK/STAT-dependent Pim kinases. Recently, the E17K mutation in the AKT1 has been associated with multiple human malignancies and leukemia in mice. However, this mutation has not been identified in Abl-transformed cells. We investigated the presence of the AKT1(E17K) mutation in v-Abl-transformed cell clones. AKT1(E17K) was detected in 3 (2.6%) of 116 specimens examined. To show the involvement of AKT1(E17K) directly in v-Abl-mediated tumorigenesis, we infected bone marrow cells from mice with bicistronic retroviruses encoding v-Abl and either wild-type or the mutant AKT1. Interestingly, we found that E17K mutant greatly increased the v-Abl transformation efficiency as compared with wild-type AKT1. Ectopic expression of E17K mutant increased the expression levels of antiapoptotic protein BCL2 and phosphorylation levels of proapoptotic protein BAD. This correlated with an increased protection from imatinib-induced apoptosis in Abl transformants. Furthermore, AKT1(E17K) promotes survival of the Pim-deficient cells, indicating a functional link between AKT and Pim in v-Abl transformation. In addition, AKT1(E17K) delays loss of Pim-1 and Pim-2 protein levels on v-Abl inactivation, which suggests that there exists reciprocal signaling between AKT and Pim in v-Abl transformants.

Effects of Monochromatic Light on Proliferation Response of Splencyte in Broilers

To investigate the effects of various monochromatic lights on splenocyte proliferation responses, a total of 260 Arbor Acre male broilers on P1 (post‐hatching day 1) were exposed to blue light (BL), green light (GL), red light (RL) and white light treatments by light emitting diode system for 7 weeks, respectively. All light sources were equalized on the intensity of 15 lx and light period of 23 h daily. Morphological change of spleen and response of splenocyte proliferation were assessed by using histochemistry staining and colorimetric test in cultures of purified splenic cells. The results were as follows: (1) At P21, GL increased significantly the spleen weight by 163.6% and spleen index by 118.8% compared with RL (P < 0.05). Until P49, BL enhanced significantly the spleen weights by 42.2% compared with RL (P < 0.05), but no significant difference was found in the spleen index among four light‐treated groups (P > 0.05). (2) Compared with RL, GL increased significantly the diameter of splenic nodule and area of periarterial lymphatic sheath at P21 by 87.2 and 58.1%, respectively (P < 0.05); BL increased significantly the diameter of splenic nodule and area of periarterial lymphatic sheath at P49 by 64.4 and 50.5%, respectively (P < 0.05). (3) At P21, GL enhanced spleen lymphocytes proliferation in response to concanavalin A compared with RL by 50.0% (P < 0.05). Until P49, the mitogenic response in BL was significantly higher (29.4%) than that of RL (P < 0.05). (4) The interleukin‐2 (IL‐2) bioactivity was significantly increased to 34.3% in GL than in RL at P21 (P < 0.05). Until P49, the IL‐2 bioactivity in BL was significantly higher (62.2%) than that of RL (P < 0.05). (5) There was no significant difference in the nitric oxide (NO) concentration of splenocyte among RL, GL and BL groups at P21 (P > 0.05), but the concentration in RL group at P49 was significantly increased, 59.0 and 63.7% compared to that of GL and BL groups, respectively (P < 0.05). These results suggested that the monochromatic light affected splenocyte proliferation mainly because of alterations in IL‐2 bioactivity and NO production in splenocyte of broiler. In early stage of broiler growth, the action of GL was obvious, while the response of BL was stronger in later stage.

Effect of a combination of green and blue monochromatic light on broiler immune response

Our previous study suggested that green light or blue light would enhance the broiler immune response; this study was conducted to evaluate whether a combination of green and blue monochromatic light would result in improved immune response. A total of 192 Arbor Acre male broilers were exposed to white light, red light, green light, and blue light from 0 to 26 days. From 27 to 49 days, half of the broilers in green light and blue light were switched to blue light (G-B) and green light (B-G), respectively. The levels of anti-Newcastle disease virus (NDV) and anti-bovine serum albumin (BSA) IgG in G-B group were elevated by 11.9-40.3% and 17.4-48.7%, respectively, compared to single monochromatic lights (P<0.05). Moreover, the proliferation of peripheral blood T and B lymphocytes and the IL-2 concentration in the G-B groups increased by 10.4-36.2%, 10.0-50.0% and 24.7-60.3% (P<0.05), respectively, compared with the single monochromatic light groups. However, the serum TNF-α concentration in the G-B group was reduced by 3.64-40.5% compared to other groups, and no significant difference was found between the G-B and B-G groups in any type of detection index at the end of the experiment. These results suggested that the combination of G-B and B-G monochromatic light could effectively enhance the antibody titer, the proliferation index of lymphocytes and alleviate the stress response in broilers. Therefore, the combination of green and blue monochromatic light can improve the immune function of broilers.

Effect of Oestradiol on Mast Cell Number and Histamine Level in the Mammary Glands of Rat

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Melatonin plays a critical role in inducing B lymphocyte proliferation of the bursa of Fabricius in broilers via monochromatic lights

To study the role of melatonin in the monochromatic light-induced B lymphocyte proliferation of bursa, a total of 360 newly hatched broilers, including intact, sham-operated, and pinealectomized groups, were exposed to blue light (BL), green light (GL), red light (RL) and white light (WL) from a light-emitting diode system for 14d. Both in vivo and in vitro studies showed that the percentage of proliferating cell nuclear antigen (PCNA)-immunoreactive lymphocytes and the lymphocyte proliferation in response to lipopolysaccharide in the bursa of broilers in the GL intact group was the highest values among the different intact groups with altered plasma melatonin levels. Additionally, the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and total antioxidant capability (T-AOC) were the highest, whereas malondialdehyde (MDA) content and inducible nitric oxide synthase (iNOS) expression were significantly decreased in the GL intact group. After pinealectomy, the levels of SOD, GSH-Px and T-AOC decreased remarkably in the various light-treatment groups, whereas the MDA content and iNOS expression significantly increased. The administration of exogenous melatonin (250pg/mL) in vitro also significantly enhanced the bursal B lymphocyte proliferation. These findings suggest that GL illumination effectively elevates the antioxidative capacity to promote B lymphocyte proliferation of bursa in young broilers, which might depend on enhanced melatonin secretion.

Restraint stress alters immune parameters and induces oxidative stress in the mouse uterus during embryo implantation

Abstract The influence of stress on embryo implantation is not well understood. Prior studies have focused on later gestational stages and the long-term impact of stress on immune function. The objective of this study is to investigate the effects of restraint stress on the immune parameters and the oxidative states of the uterus during implantation. In this study, pregnant CD1 mice were subjected to restraint stress (4 h/d) on embryonic day 1 (E1) and sacrificed on E3, E5, and E7. Maternal plasma corticosterone (CORT) secretion and implantation sites in the uterus were examined. The uterine (excluding embryos) homogenate and uterine lymphocytes were collected to examine oxidative stress states and associated immune parameters. The results demonstrated that restraint stress increased maternal plasma CORT secretion and reduced the number of implantation sites by 15.3% on E5 and by 26.1% on E7. Moreover, restraint stress decreased the density of uterine natural killer (uNK) cells in the endometrium by 22.1–47.9% and increased the density of mast cells in the myometrium by 55.6–76.9%. Restraint stress remarkably decreased the CD3+CD4+ T/CD3+CD8+ T cell ratio (by 26.2–28.9%) and attenuated uterine lymphocyte proliferation and secretion of cytokines. In addition, restraint stress threatened the intracellular equilibrium between oxidants and antioxidants, resulting in decreased glutathione peroxidase (GSH-PX) (32.2% and 45.7%), superoxide dismutase (SOD) (15.5% and 26.1%), and total antioxidant capacity (T-AOC) (18.4% and 18.2%) activities and increased malondialdehyde (MDA) (34.4% and 43.0%) contents on E5 and E7. In conclusion, these findings demonstrate that restraint stress causes abnormal implantation and negatively impacts immune parameters in association with oxidative stress in mice.

Monochromatic light affects the development of chick embryo liver via an anti-oxidation pathway involving melatonin and the melatonin receptor Mel1c

Wang, T., Wang, Z., Cao, J., Dong, Y. and Chen, Y. 2014. Monochromatic light affects the development of chick embryo liver via an anti-oxidation pathway involving melatonin and the melatonin receptor Mel1c. Can. J. Anim. Sci. 94: 391-400. Monochromatic light can influence muscle development during incubation and post-hatching. This process is related to IGF-1, which is primarily secreted by the liver. However, the effect of monochromatic light on liver development of chick embryo is unclear. In this study, 600 Arbor Acres fertile broiler eggs were randomly assigned to four incubators and exposed to continuous red light (R-group), green light (G-group), blue light (B-group), or a dark environment (D-group, control). The liver index of the G-group was higher than that of other groups (6.47-15.46%) at E21, accompanied by a higher percentage of proliferating cell nuclear antigen (PCNA). The superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX), and total antioxidant capability (T-AOC) contents were the highest in the G-group, and this trend was positively correlated with plasma melatonin (Mel) levels and the Mel receptor Mel1c expression of liver, while the malondialdehyde (MDA) content appeared to follow an opposite trend. In vitro, the administration of exogenous melatonin (250 pg mL-1) increased the proliferative activity and the antioxidant status of hepatocytes. However, this effect was significantly inhibited by Prazosin, a Mel1c inhibitor. These results suggest that green light improves the antioxidant status of the liver, which is mediated by melatonin and mel1c, and finally accelerates liver development.

Quantitative Analysis of Cells in the Ganglion Cell Layer of the Chick Retina: Developmental Changes in Cell Density and Cell Size

Changes in cell density and size in the ganglion cell layer (GCL) of the retina were studied in chick embryos and post‐hatching chicks. The total number of cells in the GCL increased from 3.64 million at embryonic day 8 (E8) to the maximal 7.85 million at E14. After E14, the number of cells decreased to 6.08 million at post‐hatching day 1 (P1) and 4.87 million at P8. Cell density in the GCL decreased unevenly according to retinal regions; cell density in the presumptive central area (pCA) of P8‐chicks decreased to approximately 45% of that in E8‐embryos. Densities of the nasal peripheral retina (NP) and temporal peripheral retina (TP) of P8‐chicks decreased to 23 and 18% of E8‐embryos, respectively. Differentiation of the central (44 000 cells/mm2 in pCA) – peripheral (28 000 cells/mm2 in TP) gradient in cell density was formed by E8. The presumptive dorsal area (pDA) was shaped by E11, but became obscure with age. Although ganglion cell sizes were basically uniform at E8, differentiation occurred with the appearance of larger ganglion cells after E14. Mean size of retinal ganglion cells increased 2.8‐fold in the pCA and 3.8‐fold in the TP between E8 and P8, accompanying a similar scale of decreases in cell densities.

Effect of monochromatic light on circadian rhythmic expression of clock genes in the hypothalamus of chick

To clarify the effect of monochromatic light on circadian clock gene expression in chick hypothalamus, a total 240 newly hatched chickens were reared under blue light (BL), green light (GL), red light (RL) and white light (WL), respectively. On the post-hatched day 14, 24-h profiles of seven core clock genes (cClock, cBmal1, cBmal2, cCry1, cCry2, cPer2 and cPer3) were measured at six time points (CT 0, CT 4, CT 8, CT 12, CT 16, CT 20, circadian time). We found all these clock genes expressed with a significant rhythmicity in different light wavelength groups. Meanwhile, cClock and cBmal1 showed a high level under GL, and followed a corresponding high expression of cCry1. However, RL decreased the expression levels of these genes. Be consistent with the mRNA level, CLOCK and BMAL1 proteins also showed a high level under GL. The CLOCK-like immunoreactive neurons were observed not only in the SCN, but also in the non-SCN brain region such as the nucleus anterior medialis hypothalami, the periventricularis nucleus, the paraventricular nucleus and the median eminence. All these results are consistent with the auto-regulatory circadian feedback loop, and indicate that GL may play an important role on the circadian time generation and development in the chick hypothalamus. Our results also suggest that the circadian clock in the chick hypothalamus such as non-SCN brain region were involved in the regulation of photo information.