UVA causes dual inactivation of cathepsin B and L underlying lysosomal dysfunction in human dermal fibroblasts.
UVA causes dual inactivation of cathepsin B and L underlying lysosomal dysfunction in human dermal fibroblasts.
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DOI：
10.1016/j.jphotobiol.2013.03.007
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发表时间：
2013-06-05
影响因子：
5.4
通讯作者：
Wondrak, Georg T.
中科院分区：
文献类型：
--
作者：
Lamore, Sarah D.;Wondrak, Georg T.
皮肤暴露于慢性太阳UVA辐射是光致癌和光老化的一个致病因素。最近，我们已经确定了巯基依赖性半胱氨酸蛋白酶组织蛋白酶B作为一种新的UVA靶点，在成纤维细胞自噬溶酶体功能障碍的上游进行光氧化失活。在这项研究中，我们研究了UVA对更广泛的组织蛋白酶的影响，并探讨了UVA诱导的组织蛋白酶失活在其他培养的皮肤细胞类型的发生。在真皮成纤维细胞中，长期暴露于非细胞毒性剂量的UVA导致溶酶体半胱氨酸蛋白酶组织蛋白酶B和L的显著失活，在初级角质形成细胞中未观察到这种效应，并且在初级黑素细胞中仅在较小程度上发生。为了确定UVA诱导的溶酶体损伤是否需要组织蛋白酶B和/或L的单一或双重失活，我们使用遗传方法（siRNA）来选择性地下调这些靶组织蛋白酶的酶活性。通过监测一组已建立的蛋白质标记物（包括LAMP 1、LC 3-II和p62）和电子显微镜检测到的细胞超微结构变化，我们观察到只有双重遗传拮抗作用（靶向CTSB和CTSL表达）才能模拟UVA诱导的自噬-溶酶体改变，而单一敲除（仅靶向CTSB或CTSL）不显示“UVA模拟”效应，无法重现UVA诱导的表型。两者合计，我们的数据表明，慢性UVA抑制组织蛋白酶B和L酶的活性和双失活的两种酶是一个致病因素的UVA诱导的损害皮肤成纤维细胞的溶酶体功能。
Cutaneous exposure to chronic solar UVA-radiation is a causative factor in photocarcinogenesis and photoaging. Recently, we have identified the thiol-dependent cysteine-protease cathepsin B as a novel UVA-target undergoing photo-oxidative inactivation upstream of autophagic-lysosomal dysfunction in fibroblasts. In this study, we examined UVA effects on a wider range of cathepsins and explored the occurrence of UVA-induced cathepsin inactivation in other cultured skin cell types. In dermal fibroblasts, chronic exposure to non-cytotoxic doses of UVA caused pronounced inactivation of the lysosomal cysteine-proteases cathepsin B and L, effects not observed in primary keratinocytes and occurring only to a minor extent in primary melanocytes. In order to determine if UVA-induced lysosomal impairment requires single or dual inactivation of cathepsin B and/or L, we used a genetic approach (siRNA) to selectively downregulate enzymatic activity of these target cathepsins. Monitoring an established set of protein markers (including LAMP1, LC3-II, and p62) and cell ultrastructural changes detected by electron microscopy, we observed that only dual genetic antagonism (targeting both CTSB and CTSL expression) could mimic UVA-induced autophagic-lysosomal alterations, whereas single knockdown (targeting CTSB or CTSL only) did not display ‘UVA-mimetic’ effects failing to reproduce the UVA-induced phenotype. Taken together, our data demonstrate that chronic UVA inhibits both cathepsin B and L enzymatic activity and that dual inactivation of both enzymes is a causative factor underlying UVA-induced impairment of lysosomal function in dermal fibroblasts.
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影响因子：
3.1
作者：
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通讯作者：
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通讯作者：
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