Astrocyte cell lineage. V. Similarity of astrocytes that form in the presence of dBcAMP in cultures to reactive astrocytes in vivo

Abstract

The relationship between astrocytes forming in the presence of dibutyryl cyclic AMP (dBcAMP) in culture and reactive astrocytes responding to a cerebral cortex stab wound was investigated. using computerized image analysis (Zeiss IBAS 1) and immunocytochemical staining. The diameters of the nuclei of astrocytes in primary cultures of newborn mouse neopallial cells were compared to those of the nuclei of normal and reactive astrocytes in histological sections of mouse cerebral cortex. We found that the nuclei of astrocytes that formed in the presence of dBcAMP in cultures are significantly larger than those of spontaneously occurring small stellate astrocytes in culture and of normal astrocytes of the cerebral cortex in vivo but corresponded more closely to the nuclei of reactive astrocytes in the area surrounding a stab wound in the cerebral cortex. Large stellate cells formed in the presence of dBcAMP had vimentin and an increase in GFP-containing intermediate filaments. Formation of reactive astrocytes in vivo is also asssociated with an increase in both vimentin and GFP-containing intermediate filaments.These observations indicate a closer relationship of astrocytes formed in the presence of dBcAMP in cultures to the reactive astrocytes in the cerebral cortex than to normal astrocytes. We propose, therefore, that the large stellate astrocytes that form in the presence of dBcAMP be referred to as reactive astrocytes in culture.

Two distinct inwardly rectifying conductances are expressed in long term dibutyryl‐cyclic‐AMP treated rat cultured cortical astrocytes

“…In contrast, the requirement of a long lasting elevation of intracellular cAMP suggests that the expression of the observed inwardly rectifying conductances relies on a time-dependent new synthesis of channel proteins which could be induced by a cAMP-regulated gene activation. Although dBcAMP treated astrocytes have been proposed to reflect reactive astrocytes [35], there are evidences indicating that in vitro dBcAMP acts as a signal that induces a physiological astrocyte differentiation with changes in both morphology and function [36,37]. In this respect it is worth to note that also in vivo rat astrocytes require several weeks after birth to reach maturity [38].…”

Differential expression of dystrophin isoforms and utrophin during dibutyryl-cAMP-induced morphological differentiation of rat brain astrocytes

“…However, in vitro, we could only find the higher level of Dp71 expression and the reduced level of utrophin in differentiated astrocytes. This may be because cultured astrocytes cannot progress into the fully matured state by treatment with dBcAMP, i.e., the dBcAMP-treated astrocytes in culture are closer to reactive astrocytes than to matured astrocytes in vivo (33).…”

APP RNA splicing is not affected by differentiation of neurons and glia in culture

“…3). Upon stimulation of the cells with bFGF (50 &ml) or CAMP (1 mM) the expression pattern of APP remained unchanged, while this treatment altered the morphology and antigen expression of astrocytes in a way that resembled a reactive gliosis [14].…”

“…For the relative quantification of APP spliceforms we used PCR amplification of APP cDNA [7] from primary cultures of neurons (from cortex, hippocampus, septum, substantia nigra and rostra1 raphe), cortical astrocytes, micro&a and oligodendrocytes. To mimic the in vivo situation of reactive gliosis, astrocytes were activated with bFGF or CAMP [14], and microglial cells with LPS, a highly potent activator of macrophages [ 151. Neurons were studied with respect to their age in culture and to the influence of appropriate survival and differentiation factors.…”