Mitogen-activated protein kinase (MAPK) pathway regulates branching by remodeling epithelial cell adhesion.
Mitogen-activated protein kinase (MAPK) pathway regulates branching by remodeling epithelial cell adhesion.
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DOI：
10.1371/journal.pgen.1004193
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发表时间：
2014-03
期刊：
影响因子：
4.5
通讯作者：
Kuure S
中科院分区：
文献类型：
--
作者：
Ihermann-Hella A;Lume M;Miinalainen IJ;Pirttiniemi A;Gui Y;Peränen J;Charron J;Saarma M;Costantini F;Kuure S
虽然生长因子（GF）信号传导引导肾分支已被很好地表征，但介导GF功能的细胞内级联却知之甚少。我们在同时缺乏双特异性蛋白激酶Mek1和Mek2的小鼠中，通过基因取消MAPK通路活性，研究了裂丝原活化蛋白激酶（MAPK）通路在发育中的肾分枝上皮中的特异性。我们的数据显示，MAPK通路在G1期和s期上皮细胞亚群中被异质性激活，其组织特异性缺失导致严重肾发育不良。因此，由于Mek1/2的缺失，上皮中ERK1/2的激活丢失，突变肾脏中正常的分支模式被仅延长的表型所取代，其中上皮在很大程度上无法形成新的分支和复杂的三维模式，但能够在有丝分裂中没有原发性缺陷的情况下生长。双突变上皮的细胞特征显示细胞表面的e -钙粘蛋白增加，并在基底外侧部位积聚。这表明了细胞粘附的变化，电镜分析显示双突变上皮细胞间间隙和细胞外间隙增加。当挑战形成单层培养时，突变上皮细胞的扩散受到损害，并表现出强烈的局灶粘连，以及尖刺的e -钙粘蛋白。抑制MAPK活性降低了paxillin在丝氨酸83上的磷酸化，而磷酸化paxillin的残余与另一种局灶黏附（FA）蛋白vinculin一起在细胞表面接触处增强。我们发现MAPK活性是分支形态发生所必需的，并提出它通过重塑细胞粘连促进细胞周期进程和更高的细胞运动性。输尿管和肾集管的发育需要上皮管（输尿管芽）的广泛生长和分支。虽然许多控制这一过程的基因是已知的，但对肾脏形态发生的细胞内信号通路仍然知之甚少。促进输尿管芽形态发生的细胞变化，如粘连和运动，是由细胞表面刺激触发的细胞内信号引导的。众所周知，丝裂原活化蛋白激酶（MAPK）途径在一般情况下调节细胞增殖，但其在不同细胞周期阶段的确切功能尚存争议。此外，MAPK活性在细胞粘附控制中的作用已在培养细胞中得到证实，但这种在体内的调节仍有待阐明。在这里，我们研究了MAPK活性在输尿管芽分支中的重要性，并发现同时缺乏Mek1和Mek2基因可以使芽伸长，但特别阻止新分支的形成。我们发现缺乏MAPK活性会导致局灶黏附分子和e -钙粘蛋白介导的细胞黏附的变化和细胞周期进程的延迟。我们的发现可能有助于理解人类某些先天性畸形的起源。
Although the growth factor (GF) signaling guiding renal branching is well characterized, the intracellular cascades mediating GF functions are poorly understood. We studied mitogen-activated protein kinase (MAPK) pathway specifically in the branching epithelia of developing kidney by genetically abrogating the pathway activity in mice lacking simultaneously dual-specificity protein kinases Mek1 and Mek2. Our data show that MAPK pathway is heterogeneously activated in the subset of G1- and S-phase epithelial cells, and its tissue-specific deletion results in severe renal hypodysplasia. Consequently to the deletion of Mek1/2, the activation of ERK1/2 in the epithelium is lost and normal branching pattern in mutant kidneys is substituted with elongation-only phenotype, in which the epithelium is largely unable to form novel branches and complex three-dimensional patterns, but able to grow without primary defects in mitosis. Cellular characterization of double mutant epithelium showed increased E-cadherin at the cell surfaces with its particular accumulation at baso-lateral locations. This indicates changes in cellular adhesion, which were revealed by electron microscopic analysis demonstrating intercellular gaps and increased extracellular space in double mutant epithelium. When challenged to form monolayer cultures, the mutant epithelial cells were impaired in spreading and displayed strong focal adhesions in addition to spiky E-cadherin. Inhibition of MAPK activity reduced paxillin phosphorylation on serine 83 while remnants of phospho-paxillin, together with another focal adhesion (FA) protein vinculin, were augmented at cell surface contacts. We show that MAPK activity is required for branching morphogenesis, and propose that it promotes cell cycle progression and higher cellular motility through remodeling of cellular adhesions. Development of the ureter and collecting ducts of the kidney requires extensive growth and branching of an epithelial tube, the ureteric bud. While many genes that control this process are known, the intracellular signaling pathways that underlie renal morphogenesis remain poorly understood. The cellular changes that contribute to ureteric bud morphogenesis, such as adhesion and movements, are guided by intracellular signaling triggered by stimuli at the cell surface. Mitogen-activated protein kinase (MAPK) pathway is known to regulate proliferation in general, but its precise functions during different cell cycle phases are debatable. Moreover, the role of MAPK activity in control of cell adhesion has been demonstrated in cultured cells, but such regulation in vivo remains to be elucidated. Here, we examine the importance of the MAPK activity in ureteric bud branching, and find that simultaneous lack of Mek1 and Mek2 genes allows elongation of the bud but specifically arrests new branch formation. We show that lack of MAPK activity leads to changes in focal adhesion molecules and E-cadherin mediated cell adhesion and delay in cell cycle progression. Our findings may help to understand the origins of certain congenital malformations in humans.
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DOI：
10.1083/jcb.201001149
发表时间：
2010-06-28
期刊：
The Journal of cell biology
影响因子：
--
作者：
le Duc Q;Shi Q;Blonk I;Sonnenberg A;Wang N;Leckband D;de Rooij J
通讯作者：
de Rooij J
影响因子：
64.8
作者：
Cavey, Matthieu;Rauzi, Matteo;Lecuit, Thomas
通讯作者：
Lecuit, Thomas
影响因子：
5.3
作者：
Lefloch, Renaud;Pouyssegur, Jacques;Lenormand, Philippe
通讯作者：
Lenormand, Philippe
影响因子：
11.8
作者：
Costantini, Frank;Kopan, Raphael
通讯作者：
Kopan, Raphael
影响因子：
11.8
作者：
Chi, Xuan;Michos, Odysse;Costantini, Frank
通讯作者：
Costantini, Frank