bims-lypmec 2026-01-25 papers

Cell Commun Signal. 2026 Jan 20.

Peripheral lysosome levels dictate mTORC1 inactivation even when catabolically impaired.

Huy Quang Dang, Therése Forssén, Spyridon Pantelios, Aisegkioul Nteli Chatzioglou, Ewa Kurzejamska, C Theresa Vincent, Yasir Ibrahim, Anders P Mutvei.

The mechanistic target of rapamycin complex 1 (mTORC1) is a central driver of cell growth that is frequently hyperactivated in cancer. While mTORC1 is activated at the lysosomal surface in response to growth factors and amino acids, the processes governing its inactivation are not fully understood. Here, we report that sustained mTORC1 suppression during leucine or arginine starvation requires the translocation of peripheral lysosomes to the perinuclear region. Our data suggest that a pool of mTOR remains active at peripheral lysosomes during starvation, and that increased spatial separation between lysosomes and the plasma membrane attenuates PI3K/Akt signaling-thereby reducing inputs that otherwise maintain mTORC1 activity. Consequently, preventing lysosome translocation and increasing peripheral lysosome levels sustains mTORC1 signaling during prolonged starvation in a PI3K/Akt-dependent manner independently of autophagy. Under these conditions, mTORC1 signaling persists even when lysosomal catabolism is perturbed by chloroquine or concanamycin A. Collectively, these data indicate that the peripheral lysosome pool, even when catabolically impaired, can sustain mTORC1 signaling under nutrient scarcity, by modulating PI3K/Akt signaling input to the pathway. These observations identify peripheral lysosome levels as a critical determinant of mTORC1 inactivation during nutrient stress and may have implications for diseases with aberrant mTORC1 signaling, including cancer.

Keywords: Amino acid deprivation; Catabolically impaired lysosomes; Lysosome positioning; MTORC1; PI3K-Akt signaling; Rab7; Rap1

DOI: https://doi.org/10.1186/s12964-026-02659-9

Front Cell Dev Biol. 2025 ;13 1663094

4-HNE-induced cellular dysfunction from lipid peroxidation: a potential therapeutic target in diabetic cardiomyopathy.

Nan Jiang, Yanchun Ma, Huijun Chen, Chengjia Li.

Diabetic cardiomyopathy (DCM) is one of the crucial causes leading to heart failure and adverse outcomes in patients with diabetes mellitus; however, effective strategies targeting its molecular pathological mechanisms and therapies are currently lacking. DCM is primarily characterized by early diastolic dysfunction, cardiomyocyte apoptosis, and fibrosis. Its disease progression is relatively insidious, eventually evolving into heart failure with preserved ejection fraction. The intrinsic metabolic environment of diabetes markedly exacerbates oxidative stress, and the accumulated polyunsaturated fatty acids within cardiomyocytes are highly susceptible to lipid peroxidation, leading to the excessive generation of 4-hydroxy-2-nonenal (4-HNE). The pivotal role of this reactive aldehyde in promoting the progression of DCM has been extensively demonstrated in animal, cellular, and clinical models. However, its subcellular targets and the underlying molecular mechanisms remain inadequately elucidated. Organelles, as central executors of diverse intracellular functions, may serve as potential sites of 4-HNE-induced interference and therapeutic targeting. This article focuses on the central role of 4-HNE in triggering energy depletion, calcium overload, autophagic flux blockade, and ferroptosis through its interactions among mitochondria, endoplasmic reticulum, lysosomes, and other organelles. On the basis of existing evidence, potentially translatable therapeutic avenues include ALDH2 activators, G protein-coupled receptor 40 (GPR40) agonists, mitochondria-targeted antioxidants and ferroptosis inhibitors. The aim is to provide a theoretical foundation and reference for the clinical identification of myocardial injury in DCM, model replication, and the development of targeted intervention strategies.

Keywords: 4-HNE; diabetic cardiomyopathy; lipid peroxidation; organelles; oxidative stress

DOI: https://doi.org/10.3389/fcell.2025.1663094

FEBS Lett. 2026 Jan 22.

Motif-guided trafficking of leishmanial PAS domain-containing phosphoglycerate kinase into glycosomes and lysosomes.

Yuthika Dholey, Gaurab Chowdhury, Puja Panja, Subrata Adak.

Recently, we showed that the Per-ARNT-Sim (PAS) domain-containing phosphoglycerate kinase from Leishmania major (LmPAS-PGK) is imported into both the glycosome and the lysosome; however, the mechanism underlying its dual targeting has remained unclear. LmPAS-PGK contains a C-terminal tripeptide sequence and two dileucine base motifs. To investigate the roles of these sorting signals, we generated different complement cell lines from null mutants by transfecting constructs encoding the wild-type protein, an L230A/L231A mutant, the C-terminal tripeptide deleted variant (∆525-527), a dileucine motif deleted variant (∆504-508), and a double-deletion mutant (∆525-527/∆504-508). Our results demonstrate that the dileucine motif governs the lysosomal targeting of LmPAS-PGK, whereas the C-terminal tripeptide is required for glycosomal localization. Deletion of both motifs abolished trafficking to either organelle, leading to cytosolic redistribution. Notably, ∆525-527, ∆504-508, and ∆525-527/∆504-508 cells displayed lower virulence compared with control cells in infected macrophages, underscoring the importance of proper LmPAS-PGK localization in Leishmania pathogenicity. Impact statement Here, we show the dileucine motif of PAS-PGK of Leishmania major governs its lysosomal targeting, whereas its C-terminal tripeptide is required for glycosomal localization. Cells lacking these domains displayed lower virulence compared with control cells in infected macrophages. These results increase our understanding of intracellular trafficking, as well as host-parasite interactions.

Keywords: Leishmania; dileucine; lysosomes; phosphoglycerate kinase; sorting motifs

DOI: https://doi.org/10.1002/1873-3468.70283