PPARs Expression in Adult Mouse Neural Stem Cells: Modulation of PPARs during Astroglial Differentiaton of NSC

PPAR isotypes are involved in the regulation of cell proliferation, death, and differentiation, with different roles and mechanisms depending on the specific isotype and ligand and on the differentiated, undifferentiated, or transformed status of the cell. Differentiation stimuli are integrated by key transcription factors which regulate specific sets of specialized genes to allow proliferative cells to exit the cell cycle and acquire specialized functions. The main differentiation programs known to be controlled by PPARs both during development and in the adult are placental differentiation, adipogenesis, osteoblast differentiation, skin differentiation, and gut differentiation. PPARs may also be involved in the differentiation of macrophages, brain, and breast. However, their functions in this cell type and organs still awaits further elucidation. PPARs may be involved in cell proliferation and differentiation processes of neural stem cells (NSC). To this aim, in this work the expression of the three PPAR isotypes and RXRs in NSC has been investigated

Association of diamineoxidase with microsomal membranes in rabbit liver.

In this paper the microsomal localization of rabbit liver diamine oxidase was demonstrated. This enzyme is belongs to the microsomal membrane and, while the release of activity from washed microsomes ocuurs exclusively in the presence of high concentration of deoxycholate, tight binding of this enzyme to membrane structure is apparent

Ornithine decarboxylase, transglutaminase, diamine oxidase and total diamines and polyamines in maternal liver and kidney throughout rat pregnancy.

Ornithine decarboxylase (ODC; EC 4.1.1.17), transglutaminase (EC 2.3.2.13), diamine oxidase (DAO; EC 1.4.3.6) and total di- and poly-amines were studied in rat liver and kidney cortex throughout pregnancy. In liver, ODC activity exhibited two major peaks (4.5-5 times the control activities) on days 15 and 17. Also putrescine and spermidine increased biphasically (3-4-fold), but no variation in spermine content was observed. Transglutaminase activity showed slight variations only near the end of gestation. In kidney, ODC activity did not fluctuate significantly during pregnancy, whereas both transglutaminase activity and putrescine content showed three major increases, in very early, middle and late pregnancy. No significant variations in spermidine and spermine were observed. In both organs, DAO activity, very low or undetectable until day 10, dramatically increased (10- and 20-fold in kidney and liver respectively) in the second half of pregnancy, reaching maxima on days 16-17 and 19. The results obtained for transglutaminase, ODC and total di- and poly-amines are interpreted on the basis of hyperplastic and hypertrophic events in the liver and kidney respectively. The behaviour of DAO suggests that the enzyme plays an important role in the control of intracellular diamine concentration

Purification of peroxisomal fraction from rat brain

A purification procedure to obtain peroxisomes (microperoxisomes) from the brain of suckling rats is reported. A P2 fraction, (crude light mitochondria) frozen and thawed seven times, was subfractionated yielding a P4 fraction, 4-fold enriched in catalase activity with respect to the cytoplasmic extract S1. The P4 fraction was used for further purification of peroxisomes by isopicnic centrifugation on Nycodenz gradient (1.10-1.20 g/ml). When the cerebellum was not included in the starting material, the equilibrium density of peroxisomes was 1.152-1.162 g/ml. In this case the overall yield of catalase in the most enriched fraction was 7% and its relative specific activity more than 50. When the cerebellum was included in the total homogenate, the equilibrium density shifted towards higher values (1.177 g/ml) and in this case the catalase relative specific activity in the peroxisomal enriched fraction was extremely high (> 100). The biochemical results, together with the electron microscope examination of the purified fractions, demonstrate that our procedure allows the best purification of brain peroxisomes so far obtained. The different equilibrium densities of peroxisomes observed in the two sets of experiments are interpreted in terms of size heterogeneity of these organelles in different brain portions and cell types