VCP maintains lysosomal homeostasis and TFEB activity in differentiated skeletal muscle
VCP maintains lysosomal homeostasis and TFEB activity in differentiated skeletal muscle
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DOI：
10.1080/15548627.2019.1569933
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发表时间：
2019-06-03
期刊：
影响因子：
13.3
通讯作者：
Weihl, Conrad C.
中科院分区：
文献类型：
--
作者：
Arhzaouy, Khalid;Papadopoulos, Chrisovalantis;Weihl, Conrad C.
分化的组织特别容易受到蛋白质和细胞器稳态改变的影响。在遗传性包涵体肌病、肌萎缩侧索硬化症和额颞叶痴呆症中突变的必需蛋白VCP对于有效清除分裂细胞中的错误折叠蛋白和受损细胞器至关重要，但其在受疾病突变影响的终末分化组织中的作用尚不清楚。为了了解VCP在分化组织中的相关性，我们在成年小鼠的骨骼肌中使其失活。令人惊讶的是，敲除肌肉表现出坏死性肌病，具有增加的巨自噬/自噬蛋白和受损的溶酶体。这不仅仅是由于自噬降解缺陷造成的，因为自噬必需蛋白ATG 5肌肉失活的年龄匹配小鼠并未表现出肌病。值得注意的是，肌纤维坏死之前是LGALS 3/半乳糖凝集素-3（受损溶酶体的标志物）和TFEB活化的上调，表明溶酶体系统中的早期缺陷。与此一致，骨骼肌中溶酶体膜透化（LMP）的化学诱导重现了肌纤维坏死。此外，TFEB在细胞中LMP后被激活，但在VCP失活或疾病突变体表达后，TFEB的激活和核定位持续存在。缩写：AAA：与多种细胞活性相关的ATP酶; TUBA 1A/-微管蛋白：微管蛋白α 1a; ATG 5：自噬相关5; ATG 7：自噬相关7; ACTA 1：肌动蛋白α 1，骨骼肌; CLEAR：协调的溶酶体表达和调节; CTSB/D：组织蛋白酶B/D; Ctrl：对照; DAPI：二脒基-2-苯基吲哚; EBSS：Earle平衡盐溶液; ELDR：内溶酶体损伤反应; ESCRT：转运所需的内体分选复合物; Gastroc/G：腓肠肌; H&E：苏木精和伊红; HSPA 5/GRP 78：热休克蛋白家族A（Hsp 70）成员5; IBMPFD/ALS：与骨的佩吉特病、额颞叶痴呆和肌萎缩侧索硬化相关的包涵体肌病;注射液：腹膜内; LAMP 1/2：溶酶体相关膜蛋白1/2; LLOMe：Leu-Leu甲酯氢溴酸盐; LGALS 3/Gal 3：半乳糖凝集素3; LMP：溶酶体膜透化作用; MTOR：雷帕霉素激酶的机制靶点; MYL 1：肌球蛋白轻链1; MAP 1 LC 3/LC 3：微管相关蛋白1轻链3; MSP：多系统蛋白病; PBS：磷酸盐缓冲盐水; PCR：聚合酶链反应; Quad/Q：四头肌; RHEB：Ras同源物，mTORC 1结合; SQSTM 1：隔离体1; TFEB：转录因子EB; TA：胫骨前肌; siRNA：小干扰RNA; SQSTM 1/p62，隔离体1; TARDBP/TDP-43：TAR DNA结合蛋白; TBS：Tris缓冲盐水; TXFN，他莫昔芬; UBXN 6/UBXD 1：UBX结构域蛋白6; VCP：含valosin的蛋白; WT：野生型。
Differentiated tissue is particularly vulnerable to alterations in protein and organelle homeostasis. The essential protein VCP, mutated in hereditary inclusion body myopathy, amyotrophic lateral sclerosis and frontotemporal dementia, is critical for efficient clearance of misfolded proteins and damaged organelles in dividing cells, but its role in terminally differentiated tissue affected by disease mutations is less clear. To understand the relevance of VCP in differentiated tissue, we inactivated it in skeletal muscle of adult mice. Surprisingly, knockout muscle demonstrated a necrotic myopathy with increased macroautophagic/autophagic proteins and damaged lysosomes. This was not solely due to a defect in autophagic degradation because age-matched mice with muscle inactivation of the autophagy essential protein, ATG5, did not demonstrate a myopathy. Notably, myofiber necrosis was preceded by upregulation of LGALS3/Galectin-3, a marker of damaged lysosomes, and TFEB activation, suggesting early defects in the lysosomal system. Consistent with that, myofiber necrosis was recapitulated by chemical induction of lysosomal membrane permeabilization (LMP) in skeletal muscle. Moreover, TFEB was activated after LMP in cells, but activation and nuclear localization of TFEB persisted upon VCP inactivation or disease mutant expression. Our data identifies VCP as central mediator of both lysosomal clearance and biogenesis in skeletal muscle.Abbreviations: AAA: ATPases Associated with diverse cellular Activities; TUBA1A/-tubulin: tubulin alpha 1a; ATG5: autophagy related 5; ATG7: autophagy related 7; ACTA1: actin alpha 1, skeletal muscle; CLEAR: coordinated lysosomal expression and regulation; CTSB/D: cathepsin B/D; Ctrl: control; DAPI: diamidino-2-phenylindole; EBSS: Earle's balanced salt solution; ELDR: endolysosomal damage response; ESCRT: endosomal sorting complexes required for transport; Gastroc/G: gastrocnemius; H&E: hematoxylin and eosin; HSPA5/GRP78: heat shock protein family A (Hsp70) member 5; IBMPFD/ALS: inclusion body myopathy associated with Paget disease of the bone, frontotemporal dementia and amyotrophic lateral sclerosis; i.p.: intraperitoneal; LAMP1/2: lysosomal-associated membrane protein 1/2; LLOMe: Leu-Leu methyl ester hydrobromide; LGALS3/Gal3: galectin 3; LMP: lysosomal membrane permeabilization; MTOR: mechanistic target of rapamycin kinase; MYL1: myosin light chain 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MSP: multisystem proteinopathy; PBS: phosphate-buffered saline; PCR: polymerase chain reaction; Quad/Q: quadriceps; RHEB: Ras homolog, mTORC1 binding; SQSTM1: sequestosome 1; TFEB: transcription factor EB; TA: tibialis anterior; siRNA: small interfering RNA; SQSTM1/p62, sequestosome 1; TARDBP/TDP-43: TAR DNA binding protein; TBS: Tris-buffered saline; TXFN, tamoxifen; UBXN6/UBXD1: UBX domain protein 6; VCP: valosin containing protein; WT: wild-type.