Differential clustering of Caspr by oligodendrocytes and Schwann cells

Abstract

Formation of the paranodal axoglial junction (PNJ) requires the presence of three cell adhesion molecules: the 155-kDa isoform of neurofascin (NF155) on the glial membrane and a complex of Caspr and contactin found on the axolemma. Here we report that the clustering of Caspr along myelinated axons during development differs fundamentally between the central (CNS) and peripheral (PNS) nervous systems. In cultures of Schwann cells (SC) and dorsal root ganglion (DRG) neurons, membrane accumulation of Caspr was detected only after myelination. In contrast, in oligodendrocytes (OL)/DRG neurons cocultures, Caspr was clustered upon initial glial cell contact already before myelination had begun. Premyelination clustering of Caspr was detected in cultures of oligodendrocytes and retinal ganglion cells, motor neurons, and DRG neurons as well as in mixed cell cultures of rat forebrain and spinal cords. Cocultures of oligodendrocyte precursor cells isolated from contactin- or neurofascin-deficient mice with wild-type DRG neurons showed that clustering of Caspr at initial contact sites between OL processes and the axon requires glial expression of NF155 but not of contactin. These results demonstrate that the expression of membrane proteins along the axolemma is determined by the type of the contacting glial cells and is not an intrinsic characteristic of the axon.

Somatodendritic Expression of JAM2 Inhibits Oligodendrocyte Myelination

“…Wrapped neuronal dendrites also exhibited clustered CASPR (Fig S2a, inset 2), but unwrapped somata and dendrites showed no CASPR clusters (Fig S2a, inset 3). This pattern of molecular organization is indicative of a direct neuroglial molecular interaction normally restricted to paranodes at the node of Ranvier (Einheber et al, 1997; Eisenbach et al, 2009; Pedraza et al, 2009). …”

Vitamin C promotes oligodendrocytes generation and remyelination

“…The results showed a significant increase in the length of the myelinated axons in As‐2P‐treated co‐cultures at both day 6 and 14 (Figure c–f). Caspr (Contactin‐associated protein), which is clustered upon OL contact and ensheathment (Eisenbach et al, ; Pedraza, Huang, & Colman, ; Yang et al, ), was also studied at day 14 in the co‐culture. As demonstrated in Figure g,h, the axonal clustering of Caspr was significantly higher in As‐2P‐treated co‐cultures.…”

In vitro myelin formation using embryonic stem cells

“…During myelination by oligodendrocytes, CASPR initially clusters at the contact sites between axon and oligodendrocyte processes, then spreads across the entire ensheathed portion of the axon and finally accumulates only at the paranodes (Eisenbach et al, 2009;Pedraza et al, 2009). This premyelination CASPR accumulation does not (B) Quantification of the number of cells immunostained for several markers of oligodendrocytes, neurons (TUJ1) and astrocytes (GFAP) at D8 and D15 (two independent experiments).…”