Invasion of Cryptococcus neoformans into human brain microvascular endothelial cells requires protein kinase C-α activation
Invasion of Cryptococcus neoformans into human brain microvascular endothelial cells requires protein kinase C-α activation
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DOI：
10.1111/j.1462-5822.2008.01172.x
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发表时间：
2008-09-01
影响因子：
3.4
通讯作者：
Huang, Sheng-He
中科院分区：
文献类型：
--
作者：
Jong, Ambrose;Wu, Chun-Hua;Huang, Sheng-He
致病真菌新型隐球菌有一个好发中枢神经系统引起毁灭性的脑膜脑炎。C.通过血脑屏障（BBB）是C.新人类我们以前的研究表明，CPS 1基因是C.新生儿粘附于人脑微血管内皮细胞（HBMEC）的表面蛋白CD 44，其构成BBB。在本报告中，我们证明了C。在存在蛋白激酶C（PKC）抑制剂G109203 X的情况下，以及通过HBMEC中显性阴性形式的PKC α的过表达，阻断了新生儿对HBMEC的侵袭。在C.在新生儿感染后，诱导了PKC α的磷酸化，并在HBMEC膜部分中检测到PKC酶活性。我们的研究结果表明，PKC α亚型可能在C。新生物入侵免疫荧光显微镜图像显示，诱导的磷酸化PKC α与β-肌动蛋白共定位在HBMEC的膜上。此外，细胞松弛素D（一种F-丝破坏剂）以剂量依赖的方式抑制真菌侵入HBMEC。此外，阻断PKC α功能减弱了C.新生物入侵这些结果表明，在真菌入侵HBMEC过程中，PKC α和下游肌动蛋白丝活性发挥了重要作用。
Pathogenic fungus Cryptococcus neoformans has a predilection for the central nervous system causing devastating meningoencephalitis. Traversal of C. neoformans across the blood-brain barrier (BBB) is a crucial step in the pathogenesis of C. neoformans. Our previous studies have shown that the CPS1 gene is required for C. neoformans adherence to the surface protein CD44 of human brain microvascular endothelial cells (HBMEC), which constitute the BBB. In this report, we demonstrated that C. neoformans invasion of HBMEC was blocked in the presence of G109203X, a protein kinase C (PKC) inhibitor, and by overexpression of a dominant-negative form of PKC alpha in HBMEC. During C. neoformans infection, phosphorylation of PKC alpha was induced and the PKC enzymatic activity was detected in the HBMEC membrane fraction. Our results suggested that the PKC alpha isoform might play a crucial role during C. neoformans invasion. Immunofluorescence microscopic images showed that induced phospho-PKC alpha colocalized with beta-actin on the membrane of HBMEC. In addition, cytochalasin D (an F-filament-disrupting agent) inhibited fungus invasion into HBMEC in a dose-dependent manner. Furthermore, blockage of PKC alpha function attenuated actin filament activity during C. neoformans invasion. These results suggest a significant role of PKC alpha and downstream actin filament activity during the fungal invasion into HBMEC.