Young Roger C, Schumann Ralph, Zhang Peisheng
Department of Obstetrics and Gynecology, Medical University of South Carolina, 96 Janathan Lucas Street, Suite 634, Charleston, SC 29425, USA.
J Muscle Res Cell Motil. 2002;23(4):279-84. doi: 10.1023/a:1022052910585.
Cultured human myocytes exhibit intercellular calcium waves that travel farther than 100 microm ('far waves'). This work investigates the mechanism of far wave propagation. Culture lines were initiated from myometrial biopsies of term pregnant women. Calcium green-1 was used as a fluorescence probe for intracellular free calcium. Serial imaging was performed at a frame rate of 0.83 frames/s. Intercellular calcium waves were mechanically initiated by atraumatically applying small drops of mineral oil onto the surface of the monolayer. Each intercellular calcium wave was scored using a standardized grid, and points were assigned depending upon the distance the wave traveled and the fluorescent intensity observed within each region. Experiments were performed in the presence of inhibitors of gap junctions and connexin hemichannels (octanol), ATP (apyrase and MDL 12330 A), prostaglandins (indomethacin, high concentrations of lanthanum), the prostaglandin transporter, PGT (DIDS), and transmembrane calcium flux (low concentrations of lanthanum). Octanol, apyrase and MDL 12330 A failed to modify the far waves, indicating gap junctions, connexin hemichannels and ATP do not participate in the paracrine mechanism. Indomethacin at 30, 100 and 300 microM, in a dose dependent manner, reduced the far wave score to 0, suggesting a prostaglandin was critically involved in the mechanism. DIDS reduced the far wave score, but did not fully inhibit wave propagation, suggesting the presence of PGT-dependent and -independent components to the mechanism. Lanthanum at 0.1 mM had no effect, but at 1 mM, reduced the far wave score. These results are consistent with PGF2alpha and/or PGE2 being the signal molecule for the PGT-dependent component. Taken together, these data indicate that long distance intercellular calcium waves in cultured human myocytes utilizes a paracrine signaling mechanism, but with more than one extracellular signaling compound.
培养的人肌细胞表现出细胞间钙波，其传播距离超过100微米（“远波”）。这项工作研究了远波传播的机制。培养系源自足月孕妇的子宫肌层活检组织。钙绿-1用作细胞内游离钙的荧光探针。以0.83帧/秒的帧率进行连续成像。通过在单层表面无创伤地滴加小滴矿物油来机械引发细胞间钙波。使用标准化网格对每个细胞间钙波进行评分，并根据波传播的距离和每个区域内观察到的荧光强度分配分数。在存在缝隙连接和连接蛋白半通道抑制剂（辛醇）、ATP（腺苷三磷酸双磷酸酶和MDL 12330 A）、前列腺素（吲哚美辛、高浓度镧）、前列腺素转运体PGT（二异丙基氨基磺酸钠）和跨膜钙通量（低浓度镧）的情况下进行实验。辛醇、腺苷三磷酸双磷酸酶和MDL 12330 A未能改变远波，表明缝隙连接、连接蛋白半通道和ATP不参与旁分泌机制。30、100和300微摩尔的吲哚美辛以剂量依赖方式将远波评分降至0，表明前列腺素在该机制中起关键作用。二异丙基氨基磺酸钠降低了远波评分，但未完全抑制波的传播，表明该机制存在PGT依赖性和非依赖性成分。0.1毫摩尔的镧没有影响，但在1毫摩尔时降低了远波评分。这些结果与PGF2α和/或PGE2作为PGT依赖性成分的信号分子一致。综上所述，这些数据表明培养的人肌细胞中的长距离细胞间钙波利用旁分泌信号机制，但涉及不止一种细胞外信号化合物。
