Cellular stress due to impairment of collagen prolyl hydroxylation complex is rescued by the chaperone 4-phenylbutyrate
Cellular stress due to impairment of collagen prolyl hydroxylation complex is rescued by the chaperone 4-phenylbutyrate
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DOI：
10.1242/dmm.038521
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发表时间：
2019-06-01
影响因子：
4.3
通讯作者：
Forlino, Antonella
中科院分区：
文献类型：
--
作者：
Besio, Roberta;Garibaldi, Nadia;Forlino, Antonella
分别由软骨相关蛋白（CRTAP）、脯氨酰-3-羟化酶1（P3 H1）和亲环蛋白B（PPIB）的隐性突变引起的成骨细胞（OI）VII、VIII和IX型的特征在于过度修饰的胶原的合成。这些基因编码内质网（ER）复合物的组分，负责I型胶原蛋白中特定脯氨酸残基的3-羟基化。我们的研究解剖的复杂的蛋白质突变对细胞内稳态的影响，使用原代成纤维细胞从7个隐性OI患者。在所有细胞系中，过度修饰的I型胶原分子的细胞内滞留导致与蛋白质聚集体的存在相关的ER增大、未折叠蛋白质反应的PERK分支的活化和凋亡性死亡。4-苯基丁酸（4-PBA）的施用通过恢复ER池大小和使磷酸化PERK（p-PERK）：PERK比率和凋亡标志物的表达正常化来减轻细胞应激。该药物对自噬也有刺激作用。我们证明了4-PBA处理后细胞稳态的拯救与其伴侣活性相关，因为它增加了蛋白质分泌，恢复了ER蛋白质稳态，并在存在自噬的药理学抑制的情况下降低了PERK活化和细胞存活。我们的研究结果提供了一个新的洞察4-PBA行动的机制，并表明，在隐性OI的细胞内应力可以减轻4-PBA治疗，类似于我们最近报道的显性OI，从而允许一个共同的目标OI形式的特点是过度修饰collagin.This文章有相关的第一人称采访的第一作者的文件。
Osteogenesis imperfecta (OI) types VII, VIII and IX, caused by recessive mutations in cartilage-associated protein (CRTAP), prolyl-3-hydroxylase 1 (P3H1) and cyclophilin B (PPIB), respectively, are characterized by the synthesis of overmodified collagen. The genes encode for the components of the endoplasmic reticulum (ER) complex responsible for the 3-hydroxylation of specific proline residues in type I collagen. Our study dissects the effects of mutations in the proteins of the complex on cellular homeostasis, using primary fibroblasts from seven recessive OI patients. In all cell lines, the intracellular retention of overmodified type I collagen molecules causes ER enlargement associated with the presence of protein aggregates, activation of the PERK branch of the unfolded protein response and apoptotic death. The administration of 4-phenylbutyrate (4-PBA) alleviates cellular stress by restoring ER cisternae size, and normalizing the phosphorylated PERK (p-PERK):PERK ratio and the expression of apoptotic marker. The drug also has a stimulatory effect on autophagy. We proved that the rescue of cellular homeostasis following 4-PBA treatment is associated with its chaperone activity, since it increases protein secretion, restoring ER proteostasis and reducing PERK activation and cell survival also in the presence of pharmacological inhibition of autophagy. Our results provide a novel insight into the mechanism of 4-PBA action and demonstrate that intracellular stress in recessive OI can be alleviated by 4-PBA therapy, similarly to what we recently reported for dominant OI, thus allowing a common target for OI forms characterized by overmodified collagen.This article has an associated First Person interview with the first author of the paper.