CRYPTDIN EFFECTS ON CRYPT EPITHELIA

Cryptdin是释放到肠腺腔中的一种防御素形式 由特化的上皮细胞如潘氏细胞形成。 这些分子 表现出抗菌活性，因此可能参与防御 隐窝上皮表面，也许是为了保护肠道 上皮细胞表面。 我们已经生成了飞行员数据， 这些分子可以通过与隐窝顶端膜相互作用， 改变隐窝上皮单层的电生理特性。 特异性纯化的cryptdin诱导离子的净产电转运 穿过这一上皮， 频道 这些数据特别令人感兴趣，因为众所周知， 其他种类的防御素分子可以在细胞中产生阴离子选择性孔， 人造膜 手头的数据与cryptdin最为吻合 诱导产电C1转运-保护粘膜的事件 用等渗溶液“冲洗”表面。 在这个项目中，我们 将首先描述运输事件的性质， cryptdins。 其次，我们将使用隐窝上皮单层， 透化基底外侧膜，以更好地表征 穴状蛋白诱导的气孔。 第三，我们将研究分数 来源于纯化的cryptdin种类，以鉴定特定的 crytdin组分中对隐窝有影响的分子 上皮细胞 最后，我们将使用合成肽来验证 对上皮转运产生影响的肽类 然后合成突变的肽种类以执行结构-功能 分析。 这样的数据应该提供对串扰之间的见解 潘氏细胞和其他隐窝细胞并产生有关如何 这些细胞类型相互作用以防御隐窝单位。

Cryptdins are a form of defensin released into the intestinal crypt lumen by specialized epithelial cells such as Paneth cells. These molecules exhibit antimicrobial activity and thus likely participate in defense of the crypt epithelial surface and perhaps in defense of the intestinal epithelial surface in general. We have generated pilot data indicating that these molecules can, by interacting with crypt apical membranes, alter the electrophysiological properties of crypt epithelial monolayers. Specifically purified cryptdin induces net electrogenic transport of ions across this epithelium associated with the introduction of an apical channel. These data are of particular interest since it is known that other species of defensin molecules can produce anion selective pores in artificial membranes. The data in hand are most consistent with cryptdin induction of electrogenic C1 transport- an event which protects mucosal surfaces by "flushing" them with isotonic solution. In this project we will first characterize the nature of the transport event stimulated by cryptdins. Secondly, we will then use crypt epithelial monolayers with permeabilized basolateral membranes to better characterize the nature of the pore induced by cryptdins. Thirdly, we will examine fractions derived from purified cryptdin species in order to identify the specific molecule(s) in the crytdin fraction responsible for the effects on crypt epithelia. Lastly, we will use synthetic peptides to verify the peptide(s) species responsible for these effects on epithelial transport and then synthesize mutant peptide species to perform structure-function analyses. Such data should provide insights into cross-talk between Paneth cells and other crypt cells and yield information concerning how these cell type interact in defense to the crypt unit.