Secreted Amyloid Precursor Protein β and Secreted Amyloid Precursor Protein α Induce Axon Outgrowth In Vitro through Egr1 Signaling Pathway

BACKGROUND: sAPPα released after α secretase cleavage of Amyloid Precursor Protein (APP) has several functions including the stimulation of neurite outgrowth although detailed morphometric analysis has not been done. Two domains involved in this function have been described and are present in sAPPβ released at the first step of amyloid peptide cleavage, raising the possibility that sAPPβ could also stimulate neurite outgrowth. We investigated the morphological effects of sAPPα and sAPPβ on primary neurons and identified a key signaling event required for the changes observed. METHODOLOGY/PRINCIPAL FINDINGS: Final concentrations of 50 to 150 nM bacterial recombinant sAPPα or sAPPβ added to primary neuronal cultures after 1 day in vitro decreased cell adhesion 24 hours later and primary dendrite length 96 hours later. 150 nM sAPPα and sAPPβ induced a similar increase of axon outgrowth, although this increase was already significant at 100 nM sAPPα. These morphological changes induced by sAPPs were also observed when added to differentiated neurons at 5 days in vitro. Real time PCR and immunocytochemistry showed that sAPPα and sAPPβ stimulated Egr1 expression downstream of MAPK/ERK activation. Furthermore, in primary neurons from Egr1 -/- mice, sAPPs affected dendritic length but did not induce any increase of axon length. CONCLUSION/SIGNIFICANCE: sAPPα and sAPPβ decrease cell adhesion and increase axon elongation. These morphological changes are similar to what has been observed in response to heparan sulfate. The sAPPα/sAPPβ stimulated increase in axon growth requires Egr1 signaling. These data suggest that sAPPβ is not deleterious per se. Since sAPPβ and sAPPα are present in the embryonic brain, these two APP metabolites might play a role in axon outgrowth during development and in response to brain damage

ANTIOXIDANT AND THERAPEUTIC EFFICACY OF PROANTHOCYANIDIN IN SODIUM FLUORIDE-INTOXICATED MICE

In a study to assess the antioxidant activity of proanthocyanidin (Pro), 90 adult female Balb/c mice weighing 35-40 g were evenly divided into six groups. The experimental groups were administered Pro by gavage (25-50 mg/kg bw/day) (Pro-25, Pro-50) and sodium fluoride in drinking water (250 mg F ion/L) either alone (F in DW) or consecutively (F+Pro-25 and F+Pro-50) in certain periods of the trial. Blood samples were collected in heparinised tubes on days 0, 7, 8,10,12, and 15. Compared to the control group, plasma malondialdehyde (MDA) levels increased significantly at day 7 by 54.25%, 57.76%, and 53.71% and at day 8 by 47.33%, 54.41%, and 48.40% for the F in DW, F+Pro-25, and F+Pro-50 groups, respectively. On the other hand, erythrocyte superoxide dismutase (SOD) activities decreased significantly at day 7 by 48.15%, 46.30%, and 48.15% and at day 8 by 43.40%, 37.74%, and 37.74% for the same groups. Like MDA levels, erythrocyte catalase (CAT) activities increased significantly at day 8 by 59.50%, 56.20%, and 58.68%, at day 10 by 42.52%, 38.58%, and 38.58%, and at day 12 by 47.50%, 34.17%, and 27.50% for the same groups. On day 10, the plasma MDA levels in the F+Pro-25, and F+Pro-50 groups were decreased by 12.48% and 15.86% compared to the F in DW group and were close to that of the control group. Similarly, on day 15, the plasma MDA in the high dosage F+Pro-50 group showed a 9.32% decrease compared to the F in DW group and was close to that of the control level. In conclusion, exposure of mice to 250 mg F/L in their drinking water for the indicated periods of time was found to cause oxidative stress that was reduced by administration of Pro

EFFECTS OF MOLDSTOP (R) ON AFLATOXICOSIS IN QUAILS

ALTINTAS, Levent/0000-0002-5148-723XWOS: 000262248800015This study was conducted to evaluate the toxic effects of anatoxin (AF) oil the growth performance of quails, and to determine the preventive efficacy of MOLDSTOP (R) (calcium formate, calcium propionate, citric acid, sorbic acid, acetic acid, and carrier). A total of 60 one-clay-old quails (Coturnix coturnix japonica) of both sexes were equally divided into four experimental groups each comprising of five replicates of three birds. The supplementation of diet with AF decreased significantly (P<0.001) the feed consumption. The 0.5% addition of MOLDSTOP (R) to the AF diet did not significantly prevent or reduce negative effect of AF on feed consumption at any time period. Light microscopic examination demonstrated that the addition of MOLDSTOP (R) did not decrease flat deposition Caused by the toxin, and besides, an electron microscopic examination indicated the reorganisation in the endoplasmic reticulum and increase in the number of ribosomes and polisomes compared to the AF plus MOLDSTOP (R) group. The data indicated that the addition of MOLDSTOP (R) to diets containing AF did not prevent the negative effects of AF observed in the quail

The effects of experimental aflatoxicosis on the exocrine pancreas in quails (Coturnix coturnix japonica)

Essiz, Dinc/0000-0002-4759-7858WOS: 000248109400006PubMed: 17486318The present investigation was undertaken to assess the effects of aflatoxin (AF) on the exocrine pancreas in quails by means of light and electron microscopy. A total of 30 quails were divided into three groups, each composed of ten animals. Total AF was incorporated into the diet of these groups, at doses of 0, 2.5, and 5.0 mg of AF/kg feed, ppm, respectively. The quails were raised in cages with electrical heating and 24-h lighting for a period of 3 weeks. Ad libitum access was provided to feed and drinking water. Pancreas samples were taken for light and electron microscopic examination from animals that were killed by means of cervical dislocation at the end of the study. Light microscopic examination demonstrated mild mononuclear cell infiltration of exocrine tissue and vacuolisation of acinar cells in the group fed on AF at 2.5 ppm. On the other hand, electron microscopic examination demonstrated degranulation of the rough endoplasmic reticulum (rER) of acinar cells, decrease in the number of zymogen granules and free ribosomes and polisomes, and dilatation of capillaries in the group fed on AF at a dose of 2.5 ppm. Numerous degenerative acinar cells were determined in the group fed a diet containing 5.0 ppm AF, in addition to the findings common with the other group exposed to the toxin

Prophylactic effect of N-acetylcysteine against sodium fluoride-induced blood oxidative stress in mice

Ninety female Balb/c mice were used. The animals were allocated to evenly six groups. While the first group was maintained as control. Groups 3, 4, 5, and 6 were administered 750 ppm, 1500 ppm, 3000 ppm, and 6000 ppm of N-acetylcysteine, respectively, for a period of 15 days. After day 15. Groups 2-6 were administered sodium fluoride, containing 100 ppm fluoride in drinking water, for another 15 days. Plasma malondialdehyde (MDA) levels and erythrocyte superoksid dismutase (SOD) and catalase (CAT) activities were determined at the beginning of the trial and on days 15 and 30. According to the data obtained in the present study, N-acetylcysteine, when administered at the indicated doses, did not produce a significant alteration in any of the three parameters investigated. On the other hand, while the plasma MDA level was determined to have increased significantly, erythrocyte SOD and CAT activities were ascertained to have decreased significantly in the group, which was administered sodium fluoride alone on day 30. In the groups, which were administered N-acetylcysteine prior to sodium fluoride, however, it was observed that, after sodium fluoride administration, plasma MDA levels and erythrocyte SOD and CAT activities drew closer to the values of the control group. (C) 2010 Elsevier Ltd. All rights reserved

Effects of short-term exposure to pulsed electromagnetic field on some biochemical parameters in mice

57-59Five-months-old male albino mice were subjected to an electromagnetic field (EMF) of 5 mT of magni-tude with a frequency of 60 Hz for 8hr of single application. Analysis of blood sampled on hourly basis (up to 8 hr) for levels/activities of total protein, albumin, globulin, uric acid, creatinine, cholesterol, and alkaline phosphatase indicated no significant differences (p>0.05) from that of the control group

Studies on antioxidant enzymes in mice exposed to pulsed electromagnetic fields

In this study, 56 female albino mice weighing 30-35 g were used. The animals were divided into a control and an experimental group. The animals in the experimental group were subjected to a pulsed electromagnetic field (PEMF) with a field magnitude of 50 Hz and 2 mT for 8 h each day between 0900 and 1700 for 90 days. In both control and experimental groups, blood was sampled at 45, 60, and 90 days in heparinized tubes and erythrocyte malondialdehyde levels, and superoxide dismutase, glutathione peroxidase, catalase, and glucose-6-phosphate dehydrogenase activities were determined. The results revealed that the PEMF applied chronically within the given period and field magnitude does not cause oxidative damage. (c) 2006 Elsevier Inc. All rights reserved