2. Academic Validation
  3. Lysosomal TPC2 channel as a new target of chlorpromazine and clomipramine to induce protective autophagy in L-BMAA-induced neurodegeneration

Lysosomal TPC2 channel as a new target of chlorpromazine and clomipramine to induce protective autophagy in L-BMAA-induced neurodegeneration

  • Biochem Pharmacol. 2025 Aug 10;242(Pt 2):117219. doi: 10.1016/j.bcp.2025.117219.
Valentina Tedeschi 1,  Raffaella Ciancio 1,  Giorgia Magliocca 1,  Emilia Esposito 1,  Silvia Piccirillo 2,  Valentina Rubino 3,  Alessandra Preziuso 2,  Tatiana Spadoni 4,  Noemi Di Muraglia 5,  Giuseppina Ruggiero 3,  Anna Pannaccione 1,  Agnese Secondo 6
Affiliations

Affiliations

  • 1 Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, University of Naples "Federico II", Via S. Pansini 5, Naples 80131, Italy.
  • 2 Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, Ancona 60126, Italy.
  • 3 Department of Translational Medical Sciences, University of Naples "Federico II", Via S. Pansini 5, Naples 80131, Italy.
  • 4 Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, Ancona 60126, Italy; Center of Confocal and Electronic Microscopy and CLEM, University "Politecnica delle Marche", Ancona, Italy.
  • 5 Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, University of Naples "Federico II", Via S. Pansini 5, Naples 80131, Italy; International School of Advanced Studies, University of Camerino, Camerino, Italy.
  • 6 Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, Ancona 60126, Italy. Electronic address: a.secondo@staff.univpm.it.
PMID: 40796055 DOI: 10.1016/j.bcp.2025.117219
Abstract

Several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS) are characterized by toxic aggregates accumulation due to Autophagy blockade, prompting researchers to identify new autophagy-activating drugs. Here we tested, in an in vitro ALS/PDC model, the neuroprotective effects of the antipsychotic Chlorpromazine (CPZ) and the antidepressant Clomipramine (CMI), chosen by drug repurposing approach for their ability to stimulate TPC2 lysosomal channel. Patch-clamp electrophysiology on enlarged lysosomes in NSC-34 motor neurons showed that CPZ and CMI induced large inwardly-rectifying currents, that were inhibited by TPC2 synthetic blocker trans-Ned-19. The same currents were evoked by TPC2 endogenous agonist NAADP and its mimetic agent TPC2-A1-N, and inhibited by trans-Ned-19 and siRNAs against TPC2 (siTPC2). CPZ and CMI elicited a significant [CA2+]i increase that rapidly induced nuclear translocation of TFEB (transcription factor EB), the master regulator of Autophagy. Accordingly, TPC2 stimulation by both the drugs boosted Autophagy, as revealed by the activation of Autophagy initiators ULK and AMPK α and modification of LC3-II/p62(SQSTM1) ratio. Furthermore, by normalizing Autophagy markers, CPZ and CMI counteracted the detrimental effects induced by L-BMAA, a neurotoxin mimicking ALS/PDC. Notably, siTPC2 partially reverted CMI- and CPZ-induced neuroprotection as well as that produced by NAADP. At mitochondrial level, these drugs prevented ATP reduction and ROS overproduction in motor neurons exposed to L-BMAA for 24 h. For a longer L-BMAA exposure, CPZ and CMI counteracted LDH, cytochrome C and SMAC/DIABLO release, thus preventing cell demise. These findings suggest that TPC2 activation by drug repurposing could provide novel therapeutic options for ALS via Autophagy regulation.

Keywords

ALS/PDC; Autophagy; Chlorpromazine; Clomipramine; Drug repurposing; Lysosomal Ca(2+) homeostasis; TPC2 channel.

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