Malattia Leventinese (MAL) is an inherited macular degeneration disorder characterized by retinal drusen formation in adolescence, leading to vision loss. A mutation in the fibulin-3 gene (EFEMP1) causes MAL; however, the mechanisms underlying disease onset and drusen formation remain unclear. In this study, we generated induced pluripotent stem cell–derived retinal pigment epithelial (iPSC-RPE) cells from a patient with MAL to investigate disease mechanisms and potential therapies. MAL iPSC-RPE exhibited fibulin-3 and apolipoprotein E (ApoE) aggregation, increased endoplasmic reticulum stress, and enhanced apoptosis. Long-term culture with photoreceptor outer segments led to drusen-like deposits containing ApoE, complement components, and collagen IV accumulation, and it showed activation of matrix metalloproteinase-2 (MMP2). Untargeted lipid analysis revealed increased hexosylceramide and bis-monoacylglycerophosphate levels in MAL iPSC-RPE cells. A key pathological feature was lysosomal dysfunction associated with altered regulation of lysosomal gene programs, including reduced transcription factor EB transcript levels. Treatment with trehalose, a lysosome-modulating compound, increased lysosomal content and function, reducing drusen-like deposit formation, inhibiting MMP2 activation, and suppressing apoptosis. This study highlighted lysosomal dysfunction as a contributor to RPE damage, drusen-like deposit accumulation, and extracellular matrix degradation. Pharmacological restoration of lysosomal function alleviated these defects, suggesting therapeutic potential for MAL and other drusen-related diseases, including age-related macular degeneration.
Yumi Inoue, Hanako O. Ikeda, Masayuki Hata, Yuto Iida, Keiko Okamoto-Furuta, Isao Asaka, Makoto Arita, Akitaka Tsujikawa
Usage data is cumulative from July 2026 through July 2026.
| Usage | JCI | PMC |
|---|---|---|
| Text version | 227 | 0 |
| 45 | 0 | |
| Figure | 86 | 0 |
| Supplemental data | 39 | 0 |
| Citation downloads | 15 | 0 |
| Totals | 412 | 0 |
| Total Views | 412 | |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.