Angelis Dimitrios, Delivoria-Papadopoulos Maria
Department of Pediatrics, Texas Tech University-HSC at the Permian Basin, Odessa, TX, USA.
Department of Pediatrics, Drexel University and St. Christopher's Hospital for Children, Philadelphia, PA, USA.
Mediators Inflamm. 2017;2017:2810295. doi: 10.1155/2017/2810295. Epub 2017 May 23.
Protein tyrosine phosphatases (PTPs) in conjunction with protein tyrosine kinases (PTKs) regulate cellular processes by posttranslational modifications of signal transduction proteins. PTP nonreceptor type 1B (PTP-1B) is an enzyme of the PTP family. We have previously shown that hypoxia induces an increase in activation of a class of nonreceptor PTK, the Src kinases. In the present study, we investigated the changes that occur in the expression of PTP-1B in the cytosolic component of the brain of newborn piglets acutely after hypoxia as well as long term for up to 2 weeks.
Newborn piglets were divided into groups: normoxia, hypoxia, hypoxia followed by 1 day and 15 days in FiO 0.21, and hypoxia pretreated with Src kinase inhibitor PP2, prior to hypoxia followed by 1 day and 15 days. Hypoxia was achieved by providing 7% FiO for 1 hour and PTP-1B expression was measured via immunoblotting.
PTP-1B increased posthypoxia by about 30% and persisted for 2 weeks while Src kinase inhibition attenuated the expected PTP-1B-increased expression.
Our study suggests that Src kinase mediates a hypoxia-induced increased PTP-1B expression.
蛋白酪氨酸磷酸酶（PTPs）与蛋白酪氨酸激酶（PTKs）共同作用，通过对信号转导蛋白进行翻译后修饰来调节细胞过程。蛋白酪氨酸磷酸酶非受体1B型（PTP - 1B）是PTP家族的一种酶。我们之前已经表明，缺氧会导致一类非受体PTK即Src激酶的激活增加。在本研究中，我们调查了新生仔猪大脑胞质成分中，急性缺氧后以及长达2周的长期缺氧后PTP - 1B表达的变化。
将新生仔猪分为几组：常氧组、缺氧组、缺氧后在FiO₂ 0.21环境下饲养1天和15天的组，以及在缺氧前用Src激酶抑制剂PP2预处理，然后在缺氧后饲养1天和15天的组。通过提供7% FiO₂ 1小时来实现缺氧，并通过免疫印迹法测量PTP - 1B的表达。
缺氧后PTP - 1B增加约30%，并持续2周，而Src激酶抑制减弱了预期的PTP - 1B表达增加。
我们的研究表明，Src激酶介导缺氧诱导的PTP - 1B表达增加。
