胰岛素对正常或妊娠期糖尿病孕妇人脐动脉平滑肌细胞中腺苷转运的调节作用。

Modulation of adenosine transport by insulin in human umbilical artery smooth muscle cells from normal or gestational diabetic pregnancies.

作者信息

Aguayo C, Flores C, Parodi J, Rojas R, Mann G E, Pearson J D, Sobrevia L

机构信息

Cellular and Molecular Physiology Laboratory (CMPL), Department of Physiology, Faculty of Biological Sciences, University of Concepción, PO Box 160-C, Concepción, Chile.

出版信息

J Physiol. 2001 Jul 1;534(Pt 1):243-54. doi: 10.1111/j.1469-7793.2001.00243.x.

DOI:10.1111/j.1469-7793.2001.00243.x

PMID:11433005

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2278675/

Abstract

Adenosine transport was measured in human cultured umbilical artery smooth muscle cells, isolated from non-diabetic or gestational diabetic pregnancies, under basal conditions and after pretreatment in vitro with insulin. 2. Adenosine transport in non-diabetic smooth muscle cells was significantly increased by insulin (half-maximal stimulation at 0.33 +/- 0.02 nM, 8 h) and characterized by a higher maximal rate (V(max)) for nitrobenzylthioinosine (NBMPR)-sensitive (es) saturable nucleoside transport (17 +/- 5 vs. 52 +/- 12 pmol (microg protein)(-1) min(-1), control vs. insulin, respectively) and maximal binding sites (B(max)) for [(3)H]NBMPR (0.66 +/- 0.07 vs. 1.1 +/- 0.1 fmol (microg protein)(-1), control vs. insulin, respectively), with no significant changes in Michaelis-Menten (K(m)) and dissociation (K(d)) constants. 3. In contrast, in smooth muscle cells from diabetic pregnancies, where the values of V(max) for adenosine transport (59 +/- 4 pmol (microg protein)(-1) min(-1)) and B(max) for [(3)H]NBMPR binding (1.62 +/- 0.16 fmol (microg protein)(-1)) were significantly elevated by comparison with non-diabetic cells, insulin treatment (1 nM, 8 h) reduced the V(max) for adenosine transport and B(max) for [(3)H]NBMPR binding to levels detected in non-diabetic cells. 4. In non-diabetic cells, the stimulatory effect of insulin on adenosine transport was mimicked by dibutyryl cGMP (100 nM) and reduced by inhibitors of phosphatidylinositol 3-kinase (10 nM wortmannin), nitric oxide synthase (100 microM N (G)-nitro-L-arginine methyl ester, L-NAME) or protein synthesis (1 microM cycloheximide), whereas inhibition of adenylyl cyclase (100 microM SQ-22536) had no effect. 5. Wortmannin or SQ-22536, but not L-NAME or cycloheximide, attenuated the inhibitory action of insulin on the diabetes-induced stimulation of adenosine transport. 6. Protein levels of inducible NO synthase (iNOS) were similar in non-diabetic and diabetic cells, but were increased by insulin (1 nM, 8 h) only in non-diabetic smooth muscle cells. 7. Our results suggest that adenosine transport via the es nucleoside transporter is modulated differentially by insulin in either cell type. Insulin increased adenosine transport in non-diabetic cells via NO and cGMP, but inhibited the diabetes-elevated adenosine transport via activation of adenylyl cyclase, suggesting that the biological actions of adenosine may be altered under conditions of sustained hyperglycaemia in uncontrolled diabetes.

摘要

在基础条件下以及体外经胰岛素预处理后，对从非糖尿病或妊娠糖尿病孕妇分离出的人脐动脉平滑肌细胞中的腺苷转运进行了测量。2. 胰岛素可显著增加非糖尿病平滑肌细胞中的腺苷转运（在0.33±0.02 nM、8小时时达到半数最大刺激），其特征为对硝基苄硫基肌苷（NBMPR）敏感的（es）可饱和核苷转运具有更高的最大速率（V(max)）（分别为17±5与52±12 pmol（μg蛋白）⁻¹分钟⁻¹，对照与胰岛素组）以及对[³H]NBMPR的最大结合位点（B(max)）（分别为0.66±0.07与1.1±0.1 fmol（μg蛋白）⁻¹，对照与胰岛素组），米氏常数（K(m)）和解离常数（K(d)）无显著变化。3. 相比之下，在妊娠糖尿病患者的平滑肌细胞中，腺苷转运的V(max)值（59±4 pmol（μg蛋白）⁻¹分钟⁻¹）和[³H]NBMPR结合的B(max)值（1.62±0.16 fmol（μg蛋白）⁻¹）与非糖尿病细胞相比显著升高，胰岛素处理（1 nM，8小时）使腺苷转运的V(max)和[³H]NBMPR结合的B(max)降至非糖尿病细胞中检测到的水平。4. 在非糖尿病细胞中，二丁酰环磷鸟苷（100 nM）可模拟胰岛素对腺苷转运的刺激作用，而磷脂酰肌醇3激酶抑制剂（10 nM渥曼青霉素）、一氧化氮合酶抑制剂（100 μM N(G)-硝基-L-精氨酸甲酯，L-NAME）或蛋白质合成抑制剂（1 μM环己酰亚胺）可降低该作用，而腺苷酸环化酶抑制剂（10０ μM SQ-22536）则无作用。5. 渥曼青霉素或SQ-22536可减弱胰岛素对糖尿病诱导的腺苷转运刺激的抑制作用，但L-NAME或环己酰亚胺则无此作用。6. 诱导型一氧化氮合酶（iNOS）的蛋白水平在非糖尿病和糖尿病细胞中相似，但仅在非糖尿病平滑肌细胞中胰岛素（1 nM，8小时）可使其升高。7. 我们的结果表明，在两种细胞类型中，胰岛素对通过es核苷转运体的腺苷转运的调节存在差异。胰岛素通过一氧化氮和环磷鸟苷增加非糖尿病细胞中的腺苷转运，但通过激活腺苷酸环化酶抑制糖尿病时升高的腺苷转运，这表明在未控制的糖尿病持续高血糖情况下，腺苷的生物学作用可能会改变。