Chemical Chaperones Protect Epidermolysis Bullosa Simplex Keratinocytes from Heat Stress-Induced Keratin Aggregation: Involvement of Heat Shock Proteins and MAP Kinases
Chemical Chaperones Protect Epidermolysis Bullosa Simplex Keratinocytes from Heat Stress-Induced Keratin Aggregation: Involvement of Heat Shock Proteins and MAP Kinases
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DOI：
10.1038/jid.2011.93
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发表时间：
2011-08-01
影响因子：
6.5
通讯作者：
Torma, Hans
中科院分区：
文献类型：
--
作者：
Chamcheu, Jean Christopher;Navsaria, Harshad;Torma, Hans
单纯性大疱性表皮松解症 (EBS) 是一种由角蛋白基因（KRT5 或 KRT14）突变引起的水疱性皮肤病，目前尚无治疗方法。在来自严重 EBS 患者的培养角质形成细胞中发现了错误折叠的突变角蛋白聚集体。在其他蛋白质折叠疾病中，分子伴侣和泛素蛋白酶体系统的参与可能会改变疾病的严重程度。在这项研究中，在添加和不添加各种测试化合物的情况下，检查了热应激对来自两名 EBS 患者 (KRT5) 和一名健康对照的永生化细胞中角蛋白聚集的影响。在所有细胞系中均观察到热诱导（43 摄氏度，30 分钟）聚集，其数量与供体表型相关。在预先暴露于蛋白酶体抑制剂 MG132 和 p38 丝裂原激活蛋白激酶 (MAPK) 抑制剂 SB203580 的 EBS 细胞中，聚集阳性细胞的比例增加，表明蛋白酶体和磷酸化在去除突变角蛋白中的作用。相比之下，通过用两种化学伴侣，三甲胺 N-氧化物 (TMAO) 和 4-苯基丁酸酯 (4-PBA) 预处理，聚集体减少。 TMAO 还调节应激诱导的 p38/c-jun N 末端激酶 (JNK) 激活和热休克蛋白 (HSPA1A) 的表达，后者与 EBS 细胞中的磷酸化角蛋白 5 共定位。总而言之，我们的研究结果提出了 EBS 和其他角蛋白病的治疗靶点。
Epidermolysis bullosa simplex (EBS) is a blistering skin disease caused by mutations in keratin genes (KRT5 or KRT14), with no existing therapies. Aggregates of misfolded mutant keratins are seen in cultured keratinocytes from severe EBS patients. In other protein-folding disorders, involvement of molecular chaperones and the ubiquitin-proteasome system may modify disease severity. In this study, the effects of heat stress on keratin aggregation in immortalized cells from two patients with EBS (KRT5) and a healthy control were examined with and without addition of various test compounds. Heat-induced (43 degrees C, 30 minutes) aggregates were observed in all cell lines, the amount of which correlated with the donor phenotype. In EBS cells pre-exposed to proteasome inhibitor, MG132, and p38-mitogen-activated protein kinase (MAPK) inhibitor, SB203580, the proportion of aggregate-positive cells increased, suggesting a role of proteasomes and phosphorylation in removing mutated keratin. In contrast, aggregates were reduced by pretreatment with two chemical chaperones, trimethylamine N-oxide (TMAO) and 4-phenylbutyrate (4-PBA). TMAO also modulated stress-induced p38/c-jun N-terminal kinase (JNK) activation and expression of heat shock protein (HSPA1A), the latter of which colocalized with phosphorylated keratin 5 in EBS cells. Taken together, our findings suggest therapeutic targets for EBS and other keratinopathies.