Short‐term feedback regulation of bile salt uptake by bile salts in rodent liver
Short‐term feedback regulation of bile salt uptake by bile salts in rodent liver
复制标题
啮齿动物肝脏中胆盐摄取胆盐的短期反馈调节
作者：
Mühlfeld S;Domanova O;Berlage T;Stross C;Helmer A;Keitel V;Häussinger D;Kubitz R
牛磺胆酸钠共转运多肽（Ntcp）是肝细胞窦膜上主要的胆盐摄取转运蛋白。尚未在体内研究初级胆汁盐对Ntcp的短期反馈调节。在Ntcp转染的HepG 2-细胞中通过流式细胞术分析Ntcp的亚细胞定位，并通过新的自动图像分析方法在组织切片的免疫荧光图像中分析Ntcp。采用脉冲追踪技术研究了大鼠肝脏的净胆盐摄取。在表达Flag-Ntcp-EGFP（增强型绿色荧光蛋白）的HepG 2-细胞中，牛磺鹅脱氧胆酸盐（TCDC）而非牛磺胆酸盐（TC）诱导Ntcp的内吞作用。TCDC，但不是TC，引起显着的内化的Ntcp灌注大鼠肝脏，细胞内Ntcp免疫反应性的增加，而Bsep分布保持不变。这些结果与功能研究相关。用100 μmol/L TC持续灌流大鼠肝脏。加入25 μmol/L TCDC、牛磺脱氧胆酸盐（TDC）、牛磺熊脱氧胆酸盐（TUDC）或TC，持续30分钟，洗脱，然后脉冲3 [H]-TC。TCDC，而不是TDC，TUDC或TC显著增加了流出物中3 [H]-TC的量，表明正弦净TC吸收减少。这种作用对白屈菜红碱（蛋白激酶C抑制剂）和氯氰菊酯（蛋白磷酸酶2B抑制剂）敏感。磷脂酰肌醇3激酶（PI 3 K）抑制剂具有累加效应，而Erk 1/2（细胞外信号激活激酶1/2）、p38 MAPK、蛋白磷酸酶1/2A（PP 1/2A）和活性氧（ROS）不参与其中。结论：TCDC通过蛋白激酶C-和蛋白磷酸酶2B-介导的从质膜回收Ntcp调节窦膜的胆盐转运。在门静脉胆汁盐负荷增加时，这种机制可能会调节沿着腺泡的胆盐摄取，保护门静脉周围肝细胞免受有害胆盐浓度的影响。（肝脏病学2012;56：2142-2153）
The sodium taurocholate cotransporting polypeptide (Ntcp) is the major bile salt uptake transporter at the sinusoidal membrane of hepatocytes. Short‐term feedback regulation of Ntcp by primary bile salts has not yet been investigatedin vivo. Subcellular localization of Ntcp was analyzed in Ntcp‐transfected HepG2‐cells by flow cytometry and in immunofluorescence images from tissue sections by a new automated image analysis method. Net bile salt uptake was investigated in perfused rat liver by a pulse chase technique. In Flag‐Ntcp‐EGFP (enhanced green fluorescent protein) expressing HepG2‐cells, taurochenodeoxycholate (TCDC), but not taurocholate (TC), induced endocytosis of Ntcp. TCDC, but not TC, caused significant internalization of Ntcp in perfused rat livers, as shown by an increase in intracellular Ntcp immunoreactivity, whereas Bsep distribution remained unchanged. These results correlate with functional studies. Rat livers were continuously perfused with 100 μmol/L of TC. 25 μmol/L of TCDC, taurodeoxycholate (TDC), tauroursodeoxycholate (TUDC), or TC were added for 30 minutes, washed out, followed by a pulse of3[H]‐TC. TCDC, but not TDC, TUDC, or TC significantly increased the amount of3[H]‐TC in the effluent, indicating a reduced sinusoidal net TC uptake. This effect was sensitive to chelerythrine (protein kinase C inhibitor) and cypermethrin (protein phosphatase 2B inhibitor). Phosphoinositide 3‐kinase (PI3K) inhibitors had an additive effect, whereas Erk1/2 (extracellular signal activated kinase 1/2), p38MAPK, protein phosphatase 1/2A (PP1/2A), and reactive oxygen species (ROS) were not involved.Conclusion: TCDC regulates bile salt transport at the sinusoidal membrane by protein kinase C‐ and protein phosphatase 2B‐mediated retrieval of Ntcp from the plasma membrane. During increased portal bile salt load this mechanism may adjust bile salt uptake along the acinus and protect periportal hepatocytes from harmful bile salt concentrations. (HEPATOLOGY2012;56:2142–2153)
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影响因子：
29.4
作者：
Denson, LA;Sturm, E;Karpen, SJ
通讯作者：
Karpen, SJ
不同渗透压对大鼠 Bsep 基因编码胆汁盐输出泵动态定位的调节
影响因子：
13.5
作者：
M. Schmitt;R. Kubitz;S. Lizun;M. Wettstein;D. Häussinger
通讯作者：
D. Häussinger
影响因子：
4.8
作者：
Hirohashi, T;Suzuki, H;Sugiyama, Y
通讯作者：
Sugiyama, Y
影响因子：
13.5
作者：
Kubitz, R;Huth, C;Häussinger, D
通讯作者：
Häussinger, D
蛋白激酶 C 诱导牛磺胆酸钠共转运多肽的内吞作用
DOI：
10.1152/ajpgi.00180.2010
发表时间：
2010
期刊：
American journal of physiology. Gastrointestinal and liver physiology
影响因子：
--
作者：
Stross C;Helmer A;Weissenberger K;Görg B;Keitel V;Häussinger D;Kubitz R
通讯作者：
Kubitz R