Rubin J E, Catherwood B D
Research Service, Veterans Administration Medical Center, San Diego, CA.
Mol Cell Endocrinol. 1987 Aug;52(3):213-8. doi: 10.1016/0303-7207(87)90046-3.
1,25-Dihydroxyvitamin D (1,25(OH)2D3) receptors appear in cultured lymphocytes after activation; 1,25(OH)2D3 has been shown to affect both the immune function and proliferation of activated cells. However, the mechanism of these effects is not completely understood. We therefore studied the effect of 1,25(OH)2D3 on forskolin-stimulated lymphocyte cAMP production during concanavalin A (ConA) activation. Purified lymphocytes were cultured with ConA; 1,25(OH)2D3 was added concurrently or 24-48 h later. To measure cAMP production, aliquots of 10(6) cells were preincubated with a phosphodiesterase inhibitor and then stimulated with the diterpene activator, forskolin (15 microM, x 10 min). The cAMP production was 4 +/- 2 pmol/10(6) cells prior to activation, increasing markedly in 48-72 h and then declining. When 1,25(OH)2D3 was added to the culture for 48 h beginning 24 h after activation, forskolin-stimulated cAMP production was consistently reduced by greater than half. This effect on cAMP production was dose dependent with half-maximal attenuation at 5 X 10(-10) M 1,25(OH)2D3. Neither 10(-8) M 24,25(OH)2D3 nor 25(OH)D3 diminished the cAMP response to forskolin. Blastic transformation was not altered by 48 h exposure to 1,25(OH)2D3 at any time during the 120 h the cultures were maintained. We conclude that 1,25(OH)2D3 can modulate cAMP production and suggest that this may contribute to other effects on T lymphocyte function. We have described the ability of 1,25(OH)2D3 to attenuate the hormone-stimulated cAMP production in other cell types and suggest that this may be a generalized mechanism through which 1,25(OH)2D3 works.
1,25 - 二羟维生素D（1,25(OH)₂D₃）受体在培养的淋巴细胞活化后出现；1,25(OH)₂D₃已被证明会影响活化细胞的免疫功能和增殖。然而，这些作用的机制尚未完全明确。因此，我们研究了1,25(OH)₂D₃在伴刀豆球蛋白A（ConA）活化过程中对福斯高林刺激的淋巴细胞环磷酸腺苷（cAMP）生成的影响。将纯化的淋巴细胞与ConA一起培养；同时或在24 - 48小时后加入1,25(OH)₂D₃。为了测量cAMP的生成，将10⁶个细胞的等分试样先用磷酸二酯酶抑制剂预孵育，然后用二萜激活剂福斯高林（15微摩尔，10分钟）刺激。活化前cAMP的生成量为4±2皮摩尔/10⁶个细胞，在48 - 72小时显著增加，然后下降。当在活化后24小时开始向培养物中加入1,25(OH)₂D₃并持续48小时时，福斯高林刺激的cAMP生成量持续减少超过一半。这种对cAMP生成的影响呈剂量依赖性，在1,25(OH)₂D₃浓度为5×10⁻¹⁰摩尔时出现半数最大衰减。10⁻⁸摩尔的24,25(OH)₂D₃和25(OH)D₃均未减弱对福斯高林的cAMP反应。在培养的120小时内的任何时间，暴露于1,25(OH)₂D₃ 48小时均未改变细胞的增殖转化。我们得出结论，1,25(OH)₂D₃可以调节cAMP的生成，并表明这可能有助于其对T淋巴细胞功能的其他作用。我们已经描述了1,25(OH)₂D₃在其他细胞类型中减弱激素刺激的cAMP生成的能力，并表明这可能是1,25(OH)₂D₃发挥作用的一种普遍机制。
