TY - JOUR
T1 - L-leucine and SPNS1 coordinately ameliorate dysfunction of autophagy in mouse and human Niemann-Pick type C disease
AU - Yanagisawa, Hiroko
AU - Ishii, Tomohiro
AU - Endo, Kentaro
AU - Kawakami, Emiko
AU - Nagao, Kazuaki
AU - Miyashita, Toshiyuki
AU - Akiyama, Keiko
AU - Watabe, Kazuhiko
AU - Komatsu, Masaaki
AU - Yamamoto, Daisuke
AU - Eto, Yoshikatsu
N1 - Funding Information:
We thank Prof. Toya Ohashi, Prof. Masataka Okabe, the Jikei University School of Medicine, for allowing us to use their laboratories, Drs. Hiroyuki Ida, Hiroshi Kobayashi and Takeo Iwamoto, the Jikei University School of Medicine, for their helpful input, and Dr. Junko Kimura-Kuroda, Tokyo Metropolitan Institute of Medical Research, for her help in operating the MetaMorph Imaging software. This work was supported, in part, by a JSPS KAKENHI Grant (JP25460510) to H. Y. The funders had no role in the study design, data collection, analysis, decision to publish, or preparation of the manuscript.
Publisher Copyright:
© 2017 The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Lysosomal storage disorders are characterized by progressive accumulation of undigested macromolecules within the cell due to lysosomal dysfunction. 573C10 is a Schwann cell line derived from a mouse model of Niemann-Pick type C disease-1, NPC (-/-). Under serum-starved conditions, NPC (-/-) cells manifested impaired autophagy accompanied by an increase in the amount of p62 and lysosome enlargement. Addition of L-leucine to serum-starved NPC (-/-) cells ameliorated the enlargement of lysosomes and the p62 accumulation. Similar autophagy defects were observed in NPC (-/-) cells even without serum starvation upon the knockdown of Spinster-like 1 (SPNS1), a putative transporter protein thought to function in lysosomal recycling. Conversely, SPNS1 overexpression impeded the enlargement of lysosomes, p62 accumulation and mislocalization of the phosphorylated form of the mechanistic Target of rapamycin in NPC (-/-) cells. In addition, we found a reduction in endogenous SPNS1 expression in fibroblasts derived from NPC-1 patients compared with normal fibroblasts. We propose that SPNS1-dependent L-leucine export across the lysosomal membrane is a key step for triggering autophagy, and that this mechanism is impaired in NPC-1.
AB - Lysosomal storage disorders are characterized by progressive accumulation of undigested macromolecules within the cell due to lysosomal dysfunction. 573C10 is a Schwann cell line derived from a mouse model of Niemann-Pick type C disease-1, NPC (-/-). Under serum-starved conditions, NPC (-/-) cells manifested impaired autophagy accompanied by an increase in the amount of p62 and lysosome enlargement. Addition of L-leucine to serum-starved NPC (-/-) cells ameliorated the enlargement of lysosomes and the p62 accumulation. Similar autophagy defects were observed in NPC (-/-) cells even without serum starvation upon the knockdown of Spinster-like 1 (SPNS1), a putative transporter protein thought to function in lysosomal recycling. Conversely, SPNS1 overexpression impeded the enlargement of lysosomes, p62 accumulation and mislocalization of the phosphorylated form of the mechanistic Target of rapamycin in NPC (-/-) cells. In addition, we found a reduction in endogenous SPNS1 expression in fibroblasts derived from NPC-1 patients compared with normal fibroblasts. We propose that SPNS1-dependent L-leucine export across the lysosomal membrane is a key step for triggering autophagy, and that this mechanism is impaired in NPC-1.
UR - http://www.scopus.com/inward/record.url?scp=85034791188&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85034791188&partnerID=8YFLogxK
U2 - 10.1038/s41598-017-15305-9
DO - 10.1038/s41598-017-15305-9
M3 - Article
AN - SCOPUS:85034791188
VL - 7
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
IS - 1
M1 - 15944
ER -
