BUSCADOR RECOLECTA

Amyotrophic lateral sclerosis (ALS) is an adult-onset motor neuron disease with a mean survival time of three years. The 97% of the cases have TDP-43 nuclear depletion and cytoplasmic aggregation in motor neurons. TDP-43 prevents non-conserved cryptic exon splicing in certain genes, maintaining transcript stability, including ATG4B, which is crucial for autophagosome maturation and Microtubule-associated proteins 1A/1B light chain 3B (LC3B) homeostasis. In ALS mice (G93A), Atg4b depletion worsens survival rates and autophagy function. For the frst time, we observed an elevation of LC3ylation in the CNS of both ALS patients and atg4b−/− mouse spinal cords. Furthermore, LC3ylation modulates the distribution of ATG3 across membrane compartments. Antisense oligonucleotides (ASOs) targeting cryptic exon restore ATG4B mRNA in TARDBP knockdown cells. We further developed multi-target ASOs targeting TDP-43 binding sequences for a broader efect. Importantly, our ASO based in peptide-PMO conjugates show brain distribution post-IV administration, ofering a non-invasive ASO-based treatment avenue for neurodegenerative diseases., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. G.M. was supported by grants from Ministerio Ciencia e Innovación (Spain) (PID2021-127534OB-I00). M.P.-O. and R.M.S. were supported by grants from Instituto de Salud Carlos III (PI20/000155, PI23/00176 and PI20/00098). R.P. was supported by Generalitat de Catalunya (2021 SGR 00990). P.T. was supported by an Unzué-Luzón grant.

Despite the great advances in macroautophagy/autophagy research in the last years, the in vivo role of the different members of the four mammalian orthologs of yeast Atg4 protease (ATG4A-D) remain unclear. To gain further insights into the functional relevance of Atg4 orthologs, we have generated mutant mice deficient in Atg4c. These mice are viable and fertile, and do not display any obvious abnormalities, indicating that they are able to develop the autophagic response required during the early neonatal period. However, they show tissue-specific autophagy alterations, including reduced autophagic flux in diaphragm and show decreased breathing and locomotor activity after fasting. In addition, atg4c-/- mice show reduced number of circulating T and B lymphocytes, which is associated with accumulation of apoptotic cells in the spleen and an increased susceptibility to develop chemically-induced fibrosarcomas. Moreover, through the analysis of cells and mice simultaneously deficient for ATG4C and ATG4D proteases we also reveal a role for ATG4C in mATG8 proteins delipidation.

ATG4 (autophagy related 4 cysteine peptidase); ATG4A (autophagy related 4A cysteine peptidase); ATG4B (autophagy related 4B cysteine peptidase); ATG4C (autophagy related 4C cysteine peptidase); ATG4D (autophagy related 4D cysteine peptidase); Atg8 (autophagy related 8); GABARAP (GABA type A receptor-associated protein); GABARAPL1(GABA type A receptor-associated protein like 1); GABARAPL2 (GABA type A receptor-associated protein like 2); MAP1LC3A/LC3A (microtubule associated protein 1 light chain 3 alpha); MAP1LC3B/LC3B (microtubule associated protein 1 light chain 3 beta); mATG8 (mammalian Atg8); PE (phosphatidylethanolamine); PS (phosphatydylserine); SQSTM1/p62 (sequestosome 1)., This work was supported by grants from Ministerio Ciencia eInnovación (Spain) (PID2021-127534OB-I00), the South-Eastern 1315 Norway Regional Health Authority (2021088 to N.E.) and Instituto de Salud Carlos III (RTICC Spain). Jesús Prieto-Lloret is funded by Programa Estrategico IBGM, Escalera de Excelencia, ref. CCVC8485, Consejería de Educación, Junta de Castilla y León (Spain). Funding for open Access Charge: Roche Farma”, as the aricle will be published via Open access and the OA costs will be funded by Roche Farma., Peer reviewed

Amyotrophic lateral sclerosis (ALS) is an adult-onset motor neuron disease with a mean survival time of three years. The 97% of the cases have TDP-43 nuclear depletion and cytoplasmic aggregation in motor neurons. TDP-43 prevents non-conserved cryptic exon splicing in certain genes, maintaining transcript stability, including ATG4B, which is crucial for autophagosome maturation and Microtubule-associated proteins 1A/1B light chain 3B (LC3B) homeostasis. In ALS mice (G93A), Atg4b depletion worsens survival rates and autophagy function. For the first time, we observed an elevation of LC3ylation in the CNS of both ALS patients and atg4b−/− mouse spinal cords. Furthermore, LC3ylation modulates the distribution of ATG3 across membrane compartments. Antisense oligonucleotides (ASOs) targeting cryptic exon restore ATG4B mRNA in TARDBP knockdown cells. We further developed multi-target ASOs targeting TDP-43 binding sequences for a broader effect. Importantly, our ASO based in peptide-PMO conjugates show brain distribution post-IV administration, offering a non-invasive ASO-based treatment avenue for neurodegenerative diseases., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. G.M. was supported by grants from Ministerio Ciencia e Innovación (Spain) (PID2021-127534OB-I00). M.P.-O. and R.M.S. were supported by grants from Instituto de Salud Carlos III (PI20/000155, PI23/00176 and PI20/00098). R.P. was supported by Generalitat de Catalunya (2021 SGR 00990). P.T. was supported by an Unzué-Luzón grant. P.T. received a Margarita Salas postdoctoral fellowship from the Spanish Ministry of Universities (Spanish Government) which was supported by NextGenerationEU. Work supported by IRBLleida Scientific and Technical Service of Immunohistochemistry.