Abstract
The conversion of cyanocobalamin to adenosyl- and methylcobalamin is impaired in cobalamin-deficient cultured human glial cells. In contrast cultured human skin fibroblasts retained their ability to synthesize coenzyme forms when grown in cobalamin-deficient medium. Cells were pre-conditioned by growing in cobalamin-deficient media for six weeks and then subcultured in medium containing either free or transcobalamin II-bound 57Co-cyanocobalamin. Although both coenzyme levels were low in cobalamin-deficient glial cells, the decrease in methylcobalamin was more marked than that of adenosylcobalamin. Methionine synthase and Cbl reductase activities were markedly decreased in cobalamin-deficient glial cells but were unchanged in fibroblasts cultured in cobalamin-deficient medium. Our data suggest that in glial cells, cobalamin coenzyme synthesis and function is exquisitely sensitive to short-term cobalamin deprivation. Glial cells apparently synthesize and secrete transcobalamin II since antibodies directed against the transport protein inhibit the uptake of free cobalamin.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 832-839 |
| Number of pages | 8 |
| Journal | Biochemical and Biophysical Research Communications |
| Volume | 184 |
| Issue number | 2 |
| DOIs | |
| State | Published - Apr 30 1992 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Molecular Biology
Cite this
Glial cells as a model for the role of cobalamin in the nervous system : Impaired synthesis of cobalamin coenzymes in cultured human astrocytes following short-term cobalamin-deprivation. / Pezacka, Ewa H.; Jacobsen, Donald W.; Luce, Kathy; Green, Ralph.
In: Biochemical and Biophysical Research Communications, Vol. 184, No. 2, 30.04.1992, p. 832-839.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Glial cells as a model for the role of cobalamin in the nervous system
T2 - Impaired synthesis of cobalamin coenzymes in cultured human astrocytes following short-term cobalamin-deprivation
AU - Pezacka, Ewa H.
AU - Jacobsen, Donald W.
AU - Luce, Kathy
AU - Green, Ralph
PY - 1992/4/30
Y1 - 1992/4/30
N2 - The conversion of cyanocobalamin to adenosyl- and methylcobalamin is impaired in cobalamin-deficient cultured human glial cells. In contrast cultured human skin fibroblasts retained their ability to synthesize coenzyme forms when grown in cobalamin-deficient medium. Cells were pre-conditioned by growing in cobalamin-deficient media for six weeks and then subcultured in medium containing either free or transcobalamin II-bound 57Co-cyanocobalamin. Although both coenzyme levels were low in cobalamin-deficient glial cells, the decrease in methylcobalamin was more marked than that of adenosylcobalamin. Methionine synthase and Cbl reductase activities were markedly decreased in cobalamin-deficient glial cells but were unchanged in fibroblasts cultured in cobalamin-deficient medium. Our data suggest that in glial cells, cobalamin coenzyme synthesis and function is exquisitely sensitive to short-term cobalamin deprivation. Glial cells apparently synthesize and secrete transcobalamin II since antibodies directed against the transport protein inhibit the uptake of free cobalamin.
AB - The conversion of cyanocobalamin to adenosyl- and methylcobalamin is impaired in cobalamin-deficient cultured human glial cells. In contrast cultured human skin fibroblasts retained their ability to synthesize coenzyme forms when grown in cobalamin-deficient medium. Cells were pre-conditioned by growing in cobalamin-deficient media for six weeks and then subcultured in medium containing either free or transcobalamin II-bound 57Co-cyanocobalamin. Although both coenzyme levels were low in cobalamin-deficient glial cells, the decrease in methylcobalamin was more marked than that of adenosylcobalamin. Methionine synthase and Cbl reductase activities were markedly decreased in cobalamin-deficient glial cells but were unchanged in fibroblasts cultured in cobalamin-deficient medium. Our data suggest that in glial cells, cobalamin coenzyme synthesis and function is exquisitely sensitive to short-term cobalamin deprivation. Glial cells apparently synthesize and secrete transcobalamin II since antibodies directed against the transport protein inhibit the uptake of free cobalamin.
UR - http://www.scopus.com/inward/record.url?scp=0026650418&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026650418&partnerID=8YFLogxK
U2 - 10.1016/0006-291X(92)90665-8
DO - 10.1016/0006-291X(92)90665-8
M3 - Article
C2 - 1349477
AN - SCOPUS:0026650418
VL - 184
SP - 832
EP - 839
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 2
ER -