1,721,018 research outputs found
Caratteristiche delle molecole di membrana di cellule nervose embrionali: interazione con lectine esogene
No full text
Muscarinic receptor subclasses in retinal cultures: effect of corticosterone.
No full textWe have previously shown that exogenously administered corticosterone affects muscarinic receptor binding in the chick embryo retina. Analysis with the selective antagonist pirenzepine has shown that both muscarinic receptor subclasses M1 and M2 are present in treated retinas. On the contrary, only M2 is detectable in controls. Moreover, receptor affinity for agonists is modified by hormone treatment. Since these studies did not show whether or not the hormone directly influences retinal cells, a similar study was performed on retinal tissue cultures. Cells were treated at day 5 in vitro for 24 hr with 1.10(-8) M corticosterone. Scatchard analysis of results obtained with 3H-quinuclidinyl benzilate (3H-QNB) binding showed no difference between treated and control cultures. However, displacement experiments demonstrated that both M1 and M2 were present in treated cultures, whereas controls had only M2. Also, receptor affinity for the agonist carbachol was modified, as already observed with in vivo studies. In addition, a new phenomenon was observed: treated cultures had a significantly higher number of cells. The possibility that the hormone can prevent cell death or stimulate cell mitosis is considered
DYSTROPHIN DISTRIBUTION IN NEURONS OF NORMAL AND DUCHENNE MUSCULAR-DYSTROPHY HUMAN FETUSES
No full textDevelopmentally regulated expression and localization of dystrophin and utrophin in the human fetal brain
No full text
Effect of dystrophin antisense oligonucleotides on cultured human neurons
No full textAntisense oligonucleotides offer the potential to block the expression of specific molecules within the cell, thus providing a useful tool in cell function studies. In this paper, we tested the possibility to block dystrophin expression in in vitro cultured neurons with antisense oligonucleotides administration. Human fetal neuronal cultures were treated with different doses of antisense oligonucleotides against dystrophin, the protein coded by the Duchenne muscular dystrophy gene. Results showed that labelled oligonucleotides rapidly accumulated into cultured neurons, but were discarded 15–24 h after treatment. However, no effects could be observed until 3–4 days after treatment, when immunocytochemical staining for dystrophin was significantly decreased in treated neurones. This result was confirmed by polymerase chain reaction assay which showed a significantly lower expression of the dystrophin specific mRNA. Electron microscope observations confirmed that neurons were affected. Large inclusions or packed granules were detectable in their cytoplasm and in terminal endings. Neuronal nuclear membrane was sometimes shredded, so that nuclear shape was altered. These phenomena were dose-dependent, further substantiating the hypothesis of a specific effect of antisense treatment. This interpretation was supported by the absense of alterations when cultures were treated with mismatch or non specific antisenses. Since the function of dystrophin is still unknown, these data might help in understanding the role played by this protein in the developing brain
- …
