Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.61 (caspase-8)
 6,833 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have used C6 glial cells (2B clone), early and late passage, as well as advanced passages (8-17) of glial cells derived from aged (18-month-old) mouse cerebral hemispheres (MACH), as model systems for studying glial properties. In this study passages 20-24 were considered "early" and passages 73-90 were considered "late." Activities of glutamine synthetase (GS) and cyclic nucleotide phosphohydrolase (CNP) were used as biochemical markers for astrocytes and oligodendrocytes, respectively. Glial phenotypes were identified immunocytochemically using double staining for glial fibrillary acidic protein (GFAP) and A2B5 antigen (type 1 and type 2 astrocytes) or galactocerebroside (GalC) and A2B5 antigen (oligodendrocytes); cells positive for A2B5 and negative for both GFAP and GalC were considered to be precursor cells. Cultures were grown either in DMEM supplemented with 10% fetal bovine serum or in serum-free chemically defined medium (CDM) supplemented with insulin and transferrin. We report that early-passage C6 glial cells continue to be bipotential cells and when grown in the absence of serum express high GS and CNP activities correlating with the high number of GFAP- and GalC-positive cells, respectively. Late-passage cells continued to be committed to the type 2 astrocytic phenotype regardless of media composition (+/- serum). MACH cultures consist of protoplasmic type 1 astrocytes, differentiated type 2 astrocytes, and oligodendrocytes as well as glial progenitor cells. When these cultures were grown in CDM+transferrin, both GS and CNP activities increased, suggesting that transferrin has provided the signal for progenitor cells present in these cultures derived from aged brain to differentiate into type 2 astrocytes and oligodendrocytes.
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PMID:Comparative biochemical, morphological, and immunocytochemical studies between C-6 glial cells of early and late passages and advanced passages of glial cells derived from aged mouse cerebral hemispheres. 136 Nov 80

We have previously reported that glial cells derived from aged mouse cerebral hemispheres (MACH) in primary cultures and after several passages consist of protoplasmic astrocytes (Type 1), differentiated stellate astrocytes (Type 2), a few oligodendrocytes, and also glial precursors. In this study, we examined the influence of culture substrata: plastic, poly-L-lysine, laminin or collagen on the differentiation of MACH glial cells of advanced passages (P18-19) using glutamine synthetase (GS) and cyclic nucleotide phosphohydrolase (CNP) activity as biochemical markers for astrocytes and oligodendrocytes, respectively. Cultures were also examined morphologically using light microscopy. In general, GS activity was increased in cultures grown on the three chemical substrata versus plastic alone with the most striking effect being the 2-fold increase observed in those cells grown in laminin. No differences were noted in CNP activity. Morphologically, proliferation of protoplasmic (Type 1) astrocytes was enhanced by culture day 2 on polylysine substratum and stellate differentiated (Type 2) astrocytes were noted on collagen. The striking feature in cultures grown on laminin was the presence of astrocytes with markedly long processes. Thus, morphological astrocyte differentiation appears to correspond to the increased GS activity. We propose that the extracellular matrix components such as collagen and laminin may play an important role in promoting glial precursors to differentiate into astrocytes.
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PMID:Influence of culture substrata on the differentiation of advanced passage glial cells in cultures from aged mouse cerebral hemispheres. 790 67

In this study we used as glial cell models, early and late passage C-6 glial cells, 2B clone, and advanced passages of glial cells derived from aged mouse cerebral hemispheres (MACH) to examine responsiveness to opioids. We have previously reported that early passage C-6 glial cells, 2B clone, are bipotential and can be geared toward oligodendrocyte or astrocytic expression, whereas late passage C-6 glial cells are astrocytic. In addition, MACH cultures have been previously characterized and consist of astrocytes type 1 and 2, some oligodendrocytes, and few glial precursors. In this study, early passage (17-20) and late passage (106-108) C-6 glial cells or MACH cells of passages 16-19 were grown from plating time until harvesting, day 7 or 8, in DMEM + 10% FBS in the presence or absence of opioid peptides, Leu-enkephalin (10(-8) to 10(-10) M) or its synthetic analog, dalargin (Tyr-D-Ala-Gly-Phe-Leu-Arg; 10(-8) to 10(-10) M). We examined for the activities of glutamine synthetase (GS) and cyclic nucleotide phosphohydrolase (CNP), enzyme markers for astrocytes and oligodendrocytes, respectively. We found that CNP activity was markedly increased in the early passage following opioid treatment, indicative of a shift to oligodendrocytic expression. In the late passage cells, already committed to astrocytic expression, opioid treatment enhanced GS activity suggesting that astrocytes respond to opioids. GS activity was markedly increased in MACH cultures grown in the presence of opioids with no changes in CNP. Thus, type 1 astrocytes, the predominant glial type in MACH cultures, responded to opioids.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Maintenance of glial plasticity with aging in C-6 glial cells and normal astrocytes in culture: responsiveness to opioid peptides. 790 40