CONTROL OF CHONDROGENIC EXPRESSION IN MESODERMAL CELLS OF EMBRYONIC CHICK LIMB
CONTROL OF CHONDROGENIC EXPRESSION IN MESODERMAL CELLS OF EMBRYONIC CHICK LIMB
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DOI：
10.1073/pnas.70.6.1713
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发表时间：
1973-01-01
影响因子：
11.1
通讯作者：
STOOLMILLER, AC
中科院分区：
文献类型：
--
作者：
CAPLAN, AI;STOOLMILLER, AC
鸡肢中胚层细胞在允许肌肉和软骨发育的条件下维持在组织培养中。 3-乙酰吡啶是一种烟酰胺拮抗的肌肉致畸剂，可增强细胞培养物中的软骨形成表达，组织学和生化标准证明，包括软骨粘蛋白的产生。木糖基转移酶和N-乙酰半乳糖氨基转移酶是软骨粘蛋白合成所需的两种酶；在3-乙酰吡啶存在和不存在的情况下以及在完整的肢体组织中培养不同时间段的中胚层细胞的分化中测量了这些酶的比活性。尽管两种转移酶的水平在培养的中胚层细胞的软骨形成过程中增加了数倍，但在培养的细胞和肢体组织中，特定酶活性的比率几乎相同。 3-Acetylpyridine 导致木糖基-和 N-乙酰半乳糖胺基转移酶的比活性分别比未处理的培养物增加 10 倍和 2 倍。与肢体组织和分化细胞培养物中的转移酶活性比率相比，3-乙酰吡啶似乎比 N-乙酰半乳糖胺基转移酶更能增加木糖基转移酶（硫酸软骨素链合成的引发剂）的活性；这一发现意味着这两种酶的合成可能是单独调节的。
Chick-limb mesodermal cells have been maintained in tissue culture under conditions that permit development of muscle and cartilage. 3-Acetylpyridine, a nicotinamide-antagonized muscle teratogen, potentiates chondrogenic expression in cell cultures, as evidenced by histological and biochemical criteria, including the production of chondromucoprotein. Xylosyltransferase andN-acetylgalactosaminyltransferase are two enzymes required for chondromucoprotein synthesis; the specific activities of these enzymes were measured in differentiating mesodermal cells cultured for various periods of time in the presence and absence of 3-acetylpyridine and in intact limb tissue. The ratios of specific enzyme activities were nearly the same in both cultured cells and limb tissue, although the levels of both transferases increased severalfold during chondrogenic expression by mesodermal cells in culture. 3-Acetylpyridine causes the specific activities of xylosyl- andN-acetylgalactosaminyltransferases to increase 10- and 2-fold, respectively, above those of untreated cultures. Compared to the ratio of transferase activities in limb tissue and differentiating cell cultures, 3-acetylpyridine appears to increase the activity of xylosyltransferase, the initiator of chondroitin sulfate chain synthesis, more than doesN-acetylgalactosaminyltransferase; this finding implies that the synthesis of these two enzymes may be separately regulated.