Activity

Data were analyzed using the MIXED procedure in SAS, and differences were reported where P ≤ 0.05. High MEI treatment pullets had 2.3-fold higher GnRH and 1.8-fold higher GnRH-RI mRNA levels than low MEI pullets. MEI affected neither expression of GnIH and GnIH-R nor carcass protein content. For high MEI (489 kcal/D) and low MEI treatments (258 kcal/D), respectively, from 22 to 26 wk of age (P ≤ 0.05), LH concentration was 3.05 and 1.60 ng/mL; FSH concentration was 145 and 89.3 pg/mL; E2 concentration was 429 and 266 pg/mL, and carcass lipid was 13.9 and 10.3%. The onset of lay for pullets in the high MEI treatment advanced such that 100% had laid by 26 wk of age compared with 30% in the low MEI treatment. We concluded that higher MEI advanced the activation of the hypothalamic-pituitary-gonadal axis and also increased body lipid deposition, and moreover, stimulated reproductive hormone levels which overall accelerated puberty in broiler breeder pullets. GS9973 Leghorn chickens are used as a preclinical model of ovarian cancer as they develop epithelial ovarian adenocarcinoma spontaneously at a very high frequency. Ovarian cancer is the most lethal disease among all gynecological malignancies in women. A small proportion of ovarian cancer stem cells are responsible for drug resistance and relapse of ovarian cancer. The objectives of this study are to isolate ovarian cancer stem cells from ascites of Leghorn chickens that spontaneously developed ovarian cancer and to determine their invasiveness, spheroid formation in three-dimensional culture devoid of extracellular matrix over several months. Ovarian cancer cells obtained from ascites were subjected to ALDEFLOUR assay that measures aldehyde dehydrogenase (ALDH) activity to separate ALDH1+ and ALDH1- cells by fluorescence-activated cell sorting. The cells were cultured using serum-free media for up to 6 mo in ultra-low attachment plates. Invasiveness of ALDH1+ and ALDH1- cells was determined by Matrigel invasion assay. Cellular uptake of acetylated low-density lipoprotein was evaluated. A small proportion ( less then 4.75%) of ovarian cancer cells isolated from ascites were found to be ALDH1+ cells. ALDH1+ cells formed a greater number of spheroids and were also highly invasive in extracellular matrix compared to ALDH1- cells. Several spheroids developed 0.1- to 1-mm-long capillary-like tubules connecting other spheroids, thus forming a complex network that underwent remodeling over several months. Cells in the spheroids incorporated acetylated low-density lipoprotein suggestive of scavenger receptor activity. In summary, ALDH1+ ovarian cancer stem cells isolated from ascites of chickens appear to be invasive and form spheroids with complex networks of tubules reminiscent of vascular mimicry. Understanding the structure and function of spheroids and tubular network would provide valuable insight into the biology of ovarian cancer and improve poultry health. This study was conducted to evaluate the effect of curcumin on laying performance, egg quality, biochemical indicators, hormone levels, and immune activity in hens under heat stress. Hy-Line brown hens (280-day-old) were fed with 0, 100, 150, and 200 mg/kg of curcumin during a 42-D experiment. Compared with the control treatment, supplementation with 150 mg/kg of curcumin improved laying performance and egg quality by significantly increasing egg production, eggshell thickness, eggshell strength (P  less then 0.01), and albumen height (P less then 0.05) while decreasing the feed-to-egg ratio. Antioxidant activity was improved by significantly increasing the activity of superoxide dismutase and glutathione peroxidase but decreasing malondialdehyde levels in serum (P less then 0.05) and significantly increasing the levels of follicle-stimulating hormone, luteinizing hormone, estradiol, IgG, IgA, and complement C3 activity in serum (P  less then  0.05). These results indicated that supplemental 150 mg/kg curcumin can improve productive performance, antioxidant enzyme activity, and immune function in laying hens under the heat stress conditions applied in the present study. The signal pathway of target of rapamycin (TOR) plays an important role in regulating cell growth and proliferation, follicular development, and ovulation. Melatonin (N-acetyl-5-methoxytryptamine) (MT) is involved in the regulation of many physiological functions in animals. Recent studies have shown that MT affects the number and the degree of maturation of follicles in the ovary, but there are few studies concerning its mechanism. Therefore, the aim of this study was to investigate the mechanism of TOR signal pathway in the regulation of ovarian function by MT in aging laying hens. In the present study, a total of 60 hens (70-week-old) were randomly divided into 2 groups control group and melatonin group (M). Melatonin was administered intraperitoneally at a dose of 20 mg/kg/D for 28 D in the M group. The results showed that MT significantly increased the levels of the antioxidant enzymes superoxide dismutase and total antioxidant capacity (P  less then 0.01) as well as levels of immunoglobulin (IgA, IgG, and IgM) (P less then 0.05) and the reproductive hormones estradiol and luteinizing hormone (P less then 0.01) in the plasma and also increased the numbers of middle white follicles and small white follicles (P less then 0.05) and decreased the level of reactive oxygen species in plasma (P less then 0.01) in laying hens. There were higher expression levels in MT receptor A (P less then 0.05), melatonin receptor B (P less then 0.01), and tuberous sclerosis complex 2 (P less then 0.01). Activation of TOR, 4E binding protein-l (4E-BP1), and ribosomal protein 6 kinase (P  less then  0.01) was found in the M. The levels of mTOR and p-mTOR protein were increased in the M (P  less then  0.05). The mTORC1-dependent 4E-BP1 and p-4E-BP1 were increased in the M (P  less then  0.05). This study indicated that MT may enhance follicle growth by increasing levels of antioxidant enzymes and reproductive hormones and by activating the mTOR and downstream components in aging laying hens.