ABSTRACT
Mental and neurological illnesses affect one in four people. While genetic linkage analyses have shown an association of nuclear distribution factor E (NDE1, or NudE) and its ohnolog NDE-like 1 (NDEL1, or Nudel) with mental disorders, the cellular mechanisms remain unclear. In the present study, we have demonstrated that Nde1 and Ndel1 are differentially localised in the subventricular zone (SVZ) of the forebrain and the subgranular zone (SGZ) of the hippocampus, two regions where neurogenesis actively occurs in the adult brain. Nde1, but not Ndel1, is localized to putative SVZ stem cells, and to actively dividing progenitors of the SGZ. The influence of these proteins on neural stem cell differentiation was investigated by overexpression in a hippocampal neural stem cell line, HCN-A94. Increasing Nde1 expression in this neural stem cell line led to increased neuronal differentiation while decreasing levels of astroglial differentiation. In primary cultured neurons and astrocytes, Nde1 and Ndel1 were found to have different but comparable subcellular localizations. In addition, we have shown for the first time that Nde1 is heterogeneously distributed in cortical astrocytes of human brains. Our data indicate that Nde1 and Ndel1 have distinct but overlapping distribution patterns in mouse brain and cultured nerve cells. They may function differently and therefore their dosage changes may contribute to some aspects of mental disorders.
Subject(s)
Brain/metabolism , Carrier Proteins/metabolism , Cell Cycle Proteins/metabolism , Microtubule-Associated Proteins/metabolism , Neural Stem Cells/metabolism , Animals , Astrocytes/metabolism , Carrier Proteins/genetics , Cell Cycle Proteins/genetics , Cell Line , Cells, Cultured , Hippocampus/metabolism , Humans , Lateral Ventricles/metabolism , Male , Mice, Inbred C57BL , Microtubule-Associated Proteins/genetics , Middle Aged , Neurons/metabolism , Prosencephalon/metabolism , RatsABSTRACT
Sub-yearling spring chinook salmon were fed either a LoFat or HiFat diet from February to November. Fish were sampled over 2 days in November, following 24- and 48-h fasts. Length vs. weight relationships between fish fed the two diets were similar; however, fish fed the HiFat diet had roughly twice the body lipid as fish fed the LoFat diet (9% vs. 4.5%, respectively). Plasma IGF-I vs. length relations between fish fed the two diets were similar; overall, there was a strong relation between plasma IGF-I and length (r(2)=0.53). Similarly, plasma log (insulin) vs. length relations did not vary between the two diets; however, the relationship of log (insulin) vs. length was weak (r(2)=0.2). There was little or no relationship between plasma IGF-I or log (insulin) and body adiposity. Finally, there was a weak relationship between plasma IGF-I and log (insulin) (r(2)=0.23).
Subject(s)
Adipose Tissue , Body Constitution , Insulin-Like Growth Factor I/metabolism , Insulin/blood , Salmon/physiology , Animals , Diet, Fat-RestrictedABSTRACT
We examined the response of growth hormone (GH), total plasma insulin-like growth-factor I (IGF-I), and growth rate to a change in ration in coho salmon. Tanks of individually tagged fish were placed on high, medium, or low ration, and sampled every 2 weeks for 8 weeks to create a range of growth rates. Some fish received non-lethal blood draws, while others were sampled terminally. Plasma IGF-I levels were higher in high ration fish than in low ration fish from 4 weeks after the beginning of experimental diets to the end of the experiment. GH levels were low and similar in all fish after changing rations, except for the fish in the low ration group at week 2. IGF-I was strongly correlated with specific growth rate in weight in terminally sampled fish after 4 weeks. GH did not correlate with growth rate or IGF-I levels. Growth parameters (length, weight, specific growth rates in weight and length, and condition factor) responded to ration. Serial sampling reduced growth rates and hematocrit, but did not change hormone levels. This study shows that IGF-I responds to changed rations within 2-4 weeks in salmonids.
Subject(s)
Diet , Growth Hormone/metabolism , Insulin-Like Growth Factor I/metabolism , Analysis of Variance , Animals , Body Constitution , Oncorhynchus kisutch , RNA, Messenger/metabolism , Time FactorsABSTRACT
Rainbow trout (Oncorhynchus mykiss) (mean initial weight 0.84 g) were fed diets containing graded levels of magnesium (Mg) (78 to 725µg/g) while being exposed to one of several levels in the rearing water (1.4 to 1000 mg/l). Uptake of Mg from the water, in Mg-deficient fish, was linearly related to the water Mg concentrated. It appears that the fish's Mg requirement can be met from either or both the diet or water. Under the experimental conditions, a water-borne concentration of 46 mg/l was calculated to be sufficient to meet the Mg requirement of the fish fed a Mg-free diet.
