A regional study of developing rat brain: The accumulation and distribution of proteolipid proteins

Abstract

The accumulation and distribution of proteolipid proteins in rat brain and selected brain regions (cerebellum, cerebral cortex, basal ganglia, and hippocampus) were studied during early postnatal development. In whole brain an eightfold increase of proteolipid was observed between ten and 33 days after birth. This was reflected in the separate regions examined where the proteolipid protein content increased six- to ten-fold during the same period. The basal ganglia and cerebral cortex contributed the greatest amount to the total proteolipid present. However, at 28-33 days the greatest concentration (mg/g tissue) was observed in the basal ganglia and hippocampus. When the proteolipid protein preparations were examined by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis, distinctive, heterogeneous patterns for each brain region were obtained. Proteolipid from basal ganglia (the region richest in white matter) consisted primarily of two major protein bands with apparent molecular weights of approximately 21,500 and 26,000. Both of these bands dramatically increased in quantity during myelination, and the larger protein coelectrophoresed with isolated myelin proteolipid protein. Both bands were also found present in proteolipid preparations from the other brain regions but in varying amounts relative to the total. The data suggest that the increase in proteolipid observed during this developmental period was due in large measure to the accumulation of myelin-specific proteolipids, but also that a significant proportion of the increase was due to the accumulation of nonmyelin components.

Synthesis of the myelin proteolipid protein in the developing mouse brain

“…Over the developmental period examined the yield of proteolipid isolated from whole mouse brains increased approximately tenfold, from a value of 0.46 mg/ brain at 16 days to 4.66 mg/brain at 44 days (Table 1). This increase in proteolipid content during this developmental period is similar to that which we and others have observed in rats (Agrawal et al, 1976;Campagnoni et al, 1976).…”

Molecular Biology of Myelin Proteins from the Central Nervous System

“…Nave et al (19874 synthesis work indicating that the two proteolipids were the products of separate mRNAs (Dautigny et al, 1983;Sorg et al, 1986) and the peptide mapping and immunological data predicting that the DM20 was identical to the PLP except for a deletion of -40 amino acid residues (Trifilieff et al, 1985(Trifilieff et al, , 1986. In addition to the PLP and DM20, the presence of other brain proteolipid polypeptides has been reported in mouse, rat, and bovine brain (Nussbaum and Mandel, 1973;Chan and Lees, 1974;Lerner et al, 1974;Campagnoni et al, 1976;Lepage et al, 1986). Lepage et al (1986) have characterized two proteolipid polypeptides with apparent molecular masses of 14 and 16 kDa using fast atom bombardment-mass spectrometry.…”

High resolution neurochemical gold staining method for myelin in peripheral and central nervous system at the light- and electron-microscopic level

“…These changes in BG staining in shiverer mice might reflect the described altered myelin membrane lamellae and membrane debris found at the ultrastructural level (Bird et al 1978;Privat et al 1979;Kirschner and Ganser 1980;Rosenbluth 1980). Central and peripheral myelin is composed of several proteins such as PLP (Campagnoni et al 1976), MAG (Li et al 1996McKerracher et al 1994;Mukhopadhyay et al 1994), P 0 (Greenfield et al 1973), Omgp (Wang et al 2002;Kottis et al 2002), chondroitin-sulfate proteoglycans (Dou and Levine 1994;Niederost et al 1999), and Rtn-4/NogoA (Chen et al 2000;GrandPre et al 2000;Prinjha et al 2000), which could all be candidate targets with different affinity for the gold stain. Since gold particles are distributed all over the central and peripheral myeloarchitecture, the gold stain probably has high affinity to more Fig.…”