Loss of CLN3, the gene mutated in juvenile neuronal ceroid lipofuscinosis, leads to metabolic impairment and autophagy induction in retinal pigment epithelium

Yu Zhong, Kabhilan Mohan, Jinpeng Liu, Ahmad Al-Attar, Penghui Lin, Robert M. Flight, Qiushi Sun, Marc O. Warmoes, Rahul R. Deshpande, Huijuan Liu, Kyung Sik Jung, Mihail I. Mitov, Nianwei Lin, D. Allan Butterfield, Shuyan Lu, Jinze Liu, Hunter N.B. Moseley, Teresa W.M. Fan, Mark E. Kleinman, Qing Jun Wang

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Juvenile neuronal ceroid lipofuscinosis (JNCL, aka. juvenile Batten disease or CLN3 disease) is a lysosomal storage disease characterized by progressive blindness, seizures, cognitive and motor failures, and premature death. JNCL is caused by mutations in the Ceroid Lipofuscinosis, Neuronal 3 (CLN3) gene, whose function is unclear. Although traditionally considered a neurodegenerative disease, CLN3 disease displays eye-specific effects: Vision loss not only is often one of the earliest symptoms of JNCL, but also has been reported in non-syndromic CLN3 disease. Here we described the roles of CLN3 protein in maintaining healthy retinal pigment epithelium (RPE) and normal vision. Using electroretinogram, fundoscopy and microscopy, we showed impaired visual function, retinal autofluorescent lesions, and RPE disintegration and metaplasia/hyperplasia in a Cln3 ~ 1 kb-deletion mouse model [1] on C57BL/6J background. Utilizing a combination of biochemical analyses, RNA-Seq, Seahorse XF bioenergetic analysis, and Stable Isotope Resolved Metabolomics (SIRM), we further demonstrated that loss of CLN3 increased autophagic flux, suppressed mTORC1 and Akt activities, enhanced AMPK activity, and up-regulated gene expression of the autophagy-lysosomal system in RPE-1 cells, suggesting autophagy induction. This CLN3 deficiency induced autophagy induction coincided with decreased mitochondrial oxygen consumption, glycolysis, the tricarboxylic acid (TCA) cycle, and ATP production. We also reported for the first time that loss of CLN3 led to glycogen accumulation despite of impaired glycogen synthesis. Our comprehensive analyses shed light on how loss of CLN3 affect autophagy and metabolism. This work suggests possible links among metabolic impairment, autophagy induction and lysosomal storage, as well as between RPE atrophy/degeneration and vision loss in JNCL.

Original languageEnglish
Article number165883
JournalBiochimica et Biophysica Acta - Molecular Basis of Disease
Volume1866
Issue number10
DOIs
StatePublished - Oct 1 2020

Bibliographical note

Funding Information:
This work was supported by a New Scholar in Aging award from Ellison Medical Foundation (to Q.J.W.), National Institutes of Health (sub-awards to Q.J.W. from Center of Biomedical Research Excellence (COBRE) awards P20GM103486 and P20GM121327 ), National Institutes of Health EY028206 and BrightFocus Foundation (to M.E.K.), and National Science Foundation grant 1419282 (to H.N.B.M.). This research was also supported by the Redox Metabolism Shared Resource Facility of the University of Kentucky Markey Cancer Center ( P30CA177558 ).

Publisher Copyright:
© 2020 Elsevier B.V.

Keywords

  • Autophagy
  • CLN3
  • Glycogen
  • Metabolism
  • Retinal pigment epithelium
  • Vision loss

ASJC Scopus subject areas

  • Molecular Medicine
  • Molecular Biology

Fingerprint

Dive into the research topics of 'Loss of CLN3, the gene mutated in juvenile neuronal ceroid lipofuscinosis, leads to metabolic impairment and autophagy induction in retinal pigment epithelium'. Together they form a unique fingerprint.

Cite this