Related Experiment Videos
Metabotropic glutamate receptor expression in cultured rat astrocytes and human gliomas
D F Condorelli1, P Dell'Albani, M Corsaro
1Institute of Biochemistry, School of Medicine, University of Catania, Italy.
Abstract:
In order to confirm the existence of metabotropic glutamate receptors in astroglial cultures and to provide information on different receptor subtypes, the expression of different mGluRs was analysed in cultures highly enriched in rat astroglial cells. mRNA levels for mGluR1, 2, 3, 4, 7 were undetectable by Northern blot analysis in primary type-1 astroglial cultures derived from total cerebral hemispheres, cerebral cortex and striatum. Interestingly, these cultures expressed a low, but detectable, level of mGluR5 mRNA. The more sensitive technique Reverse Transcription-Polymerase Chain Reaction (RT-PCR) confirmed the presence of mGluR5 transcript in cultured astrocytes and, in addition, revealed the presence of mGluR3 mRNA. The lack of expression of mGluR5 in CG-4 cells, a rat cell line able to differentiate in type-2 astrocytes or oligodendrocytes depending on the culture conditions, suggested that the presence of mGluR5 was not a general feature of cells of glial origin. Moreover, all the examined mGluR transcript were undetectable by RT-PCR in CG4 cells. In order to confirm the possible expression of mGluR5 in cell of glial origin we examined the mRNA levels for this receptor in tissue samples from human gliomas obtained after surgical resection of the tumors: only 1 sample (grade II astrocytoma), out of 8 examined, showed the presence of mGluR5 mRNA. In conclusion our data show that the only cloned metabotropic receptor linked to phosphoinositide hydrolysis, whose expression is detectable in cultured type-1 astrocytes, in mGluR5. It remains to be established if the low level of expression of mGluR3 could be responsible for the group II metabotropic glutamate receptor activity previously observed in cultured astroglial cells.
Insights
Metabotropic glutamate receptors (mGluRs) were studied in rat astroglial cells. Only metabotropic glutamate receptor 5 (mGluR5) mRNA was detected in cultured astrocytes, with limited expression in human glioma samples.
Area of Science:
- Neuroscience
- Molecular Biology
- Cell Biology
Background:
- Metabotropic glutamate receptors (mGluRs) are crucial for neuronal signaling.
- Understanding mGluR expression in glial cells is important for neurological research.
- Astroglial cells play vital roles in brain function and disease.
Purpose of the Study:
- To investigate the expression of various metabotropic glutamate receptor (mGluR) subtypes in rat astroglial cultures.
- To determine which mGluR subtypes are present in primary type-1 astrocytes.
- To explore the presence of mGluR5 in human glioma tissues.
Main Methods:
- Northern blot analysis to detect mRNA levels of mGluRs in astroglial cultures.
- Reverse Transcription-Polymerase Chain Reaction (RT-PCR) for sensitive detection of mGluR transcripts.
- Analysis of mGluR5 mRNA in human glioma tissue samples.
Main Results:
- mGluR1, 2, 3, 4, and 7 mRNA were undetectable in primary type-1 astroglial cultures.
- Low levels of mGluR5 mRNA were detected in cultured astrocytes using Northern blot and confirmed by RT-PCR.
- RT-PCR also revealed the presence of mGluR3 mRNA in cultured astrocytes.
- mGluR5 mRNA was detected in only one of eight human glioma samples (grade II astrocytoma).
Conclusions:
- Metabotropic glutamate receptor 5 (mGluR5) is the only cloned metabotropic receptor linked to phosphoinositide hydrolysis detectable in cultured type-1 astrocytes.
- The expression of mGluR5 is not a general feature of all glial cells, as shown by its absence in CG-4 cells.
- Further research is needed to determine if the low expression of mGluR3 contributes to previously observed group II mGluR activity in astroglial cells.