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1.
Annu Rev Biochem ; 93(1): 367-387, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38594929

RESUMEN

Lysosomes are the degradative endpoints of material delivered by endocytosis and autophagy and are therefore particularly prone to damage. Membrane permeabilization or full rupture of lysosomal or late endosomal compartments is highly deleterious because it threatens cellular homeostasis and can elicit cell death and inflammatory signaling. Cells have developed a complex response to endo-lysosomal damage that largely consists of three branches. Initially, a number of repair pathways are activated to restore the integrity of the lysosomal membrane. If repair fails or if damage is too extensive, lysosomes are isolated and degraded by a form of selective autophagy termed lysophagy. Meanwhile, an mTORC1-governed signaling cascade drives biogenesis and regeneration of new lysosomal components to reestablish the full lysosomal capacity of the cell. This damage response is vital to counteract the effects of various conditions, including neurodegeneration and infection, and can constitute a critical vulnerability in cancer cells.


Asunto(s)
Autofagia , Endosomas , Lisosomas , Diana Mecanicista del Complejo 1 de la Rapamicina , Transducción de Señal , Lisosomas/metabolismo , Humanos , Animales , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Endosomas/metabolismo , Endocitosis , Neoplasias/metabolismo , Neoplasias/patología , Neoplasias/genética
2.
Cell ; 174(1): 88-101.e16, 2018 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-29909986

RESUMEN

In colorectal cancer patients, a high density of cytotoxic CD8+ T cells in tumors is associated with better prognosis. Using a Stat3 loss-of-function approach in two wnt/ß-catenin-dependent autochthonous models of sporadic intestinal tumorigenesis, we unravel a complex intracellular process in intestinal epithelial cells (IECs) that controls the induction of a CD8+ T cell based adaptive immune response. Elevated mitophagy in IECs causes iron(II)-accumulation in epithelial lysosomes, in turn, triggering lysosomal membrane permeabilization. Subsequent release of proteases into the cytoplasm augments MHC class I presentation and activation of CD8+ T cells via cross-dressing of dendritic cells. Thus, our findings highlight a so-far-unrecognized link between mitochondrial function, lysosomal integrity, and MHC class I presentation in IECs and suggest that therapies triggering mitophagy or inducing LMP in IECs may prove successful in shifting the balance toward anti-tumor immunity in colorectal cancer.


Asunto(s)
Inmunidad Adaptativa , Mitofagia , Inmunidad Adaptativa/efectos de los fármacos , Animales , Azoximetano/toxicidad , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/metabolismo , Permeabilidad de la Membrana Celular , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Citocinas/metabolismo , Células Dendríticas/citología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Femenino , Compuestos Ferrosos/metabolismo , Humanos , Interferón gamma/metabolismo , Interferón gamma/farmacología , Mucosa Intestinal/citología , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Lisosomas/metabolismo , Masculino , Ratones , Ratones Noqueados , Mitofagia/efectos de los fármacos , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Tasa de Supervivencia
3.
Cell ; 173(4): 851-863.e16, 2018 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-29576452

RESUMEN

Hibernating mammals survive hypothermia (<10°C) without injury, a remarkable feat of cellular preservation that bears significance for potential medical applications. However, mechanisms imparting cold resistance, such as cytoskeleton stability, remain elusive. Using the first iPSC line from a hibernating mammal (13-lined ground squirrel), we uncovered cellular pathways critical for cold tolerance. Comparison between human and ground squirrel iPSC-derived neurons revealed differential mitochondrial and protein quality control responses to cold. In human iPSC-neurons, cold triggered mitochondrial stress, resulting in reactive oxygen species overproduction and lysosomal membrane permeabilization, contributing to microtubule destruction. Manipulations of these pathways endowed microtubule cold stability upon human iPSC-neurons and rat (a non-hibernator) retina, preserving its light responsiveness after prolonged cold exposure. Furthermore, these treatments significantly improved microtubule integrity in cold-stored kidneys, demonstrating the potential for prolonging shelf-life of organ transplants. Thus, ground squirrel iPSCs offer a unique platform for bringing cold-adaptive strategies from hibernators to humans in clinical applications. VIDEO ABSTRACT.


Asunto(s)
Adaptación Fisiológica , Células Madre Pluripotentes Inducidas/metabolismo , Neuronas/metabolismo , Animales , Diferenciación Celular , Frío , Humanos , Células Madre Pluripotentes Inducidas/citología , Riñón/efectos de los fármacos , Riñón/metabolismo , Lisosomas/metabolismo , Ratones , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Neuronas/citología , Estrés Oxidativo , Inhibidores de Proteasas/farmacología , Ratas , Especies Reactivas de Oxígeno/metabolismo , Retina/metabolismo , Sciuridae , Transcriptoma , Tubulina (Proteína)/química , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo
4.
Mol Cell ; 84(8): 1556-1569.e10, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38503285

RESUMEN

Cells respond to lysosomal membrane permeabilization by membrane repair or selective macroautophagy of damaged lysosomes, termed lysophagy, but it is not fully understood how this decision is made. Here, we uncover a pathway in human cells that detects lipid bilayer perturbations in the limiting membrane of compromised lysosomes, which fail to be repaired, and then initiates ubiquitin-triggered lysophagy. We find that SPG20 binds the repair factor IST1 on damaged lysosomes and, importantly, integrates that with the detection of damage-associated lipid-packing defects of the lysosomal membrane. Detection occurs via sensory amphipathic helices in SPG20 before rupture of the membrane. If lipid-packing defects are extensive, such as during lipid peroxidation, SPG20 recruits and activates ITCH, which marks the damaged lysosome with lysine-63-linked ubiquitin chains to initiate lysophagy and thus triages the lysosome for destruction. With SPG20 being linked to neurodegeneration, these findings highlight the relevance of a coordinated lysosomal damage response for cellular homeostasis.


Asunto(s)
Lisosomas , Macroautofagia , Humanos , Autofagia/fisiología , Membranas Intracelulares/metabolismo , Lípidos , Lisosomas/metabolismo , Ubiquitina/genética , Ubiquitina/metabolismo
5.
J Cell Sci ; 137(9)2024 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-38578235

RESUMEN

Endosomal-lysosomal trafficking is accompanied by the acidification of endosomal compartments by the H+-V-ATPase to reach low lysosomal pH. Disruption of the correct pH impairs lysosomal function and the balance of protein synthesis and degradation (proteostasis). Here, we treated mammalian cells with the small dipeptide LLOMe, which is known to permeabilize lysosomal membranes, and find that LLOMe also impacts late endosomes (LEs) by neutralizing their pH without causing membrane permeabilization. We show that LLOMe leads to hyperactivation of Rab7 (herein referring to Rab7a), and disruption of tubulation and mannose-6-phosphate receptor (CI-M6PR; also known as IGF2R) recycling on pH-neutralized LEs. pH neutralization (NH4Cl) and expression of Rab7 hyperactive mutants alone can both phenocopy the alterations in tubulation and CI-M6PR trafficking. Mechanistically, pH neutralization increases the assembly of the V1G1 subunit (encoded by ATP6V1G1) of the V-ATPase on endosomal membranes, which stabilizes GTP-bound Rab7 via RILP, a known interactor of Rab7 and V1G1. We propose a novel pathway by which V-ATPase and RILP modulate LE pH and Rab7 activation in concert. This pathway might broadly contribute to pH control during physiologic endosomal maturation or starvation and during pathologic pH neutralization, which occurs via lysosomotropic compounds and in disease states.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Endosomas , ATPasas de Translocación de Protón Vacuolares , Proteínas de Unión a GTP rab7 , Animales , Humanos , Endosomas/metabolismo , Células HeLa , Concentración de Iones de Hidrógeno , Lisosomas/metabolismo , Transporte de Proteínas , Receptor IGF Tipo 2/metabolismo , Receptor IGF Tipo 2/genética , ATPasas de Translocación de Protón Vacuolares/metabolismo , ATPasas de Translocación de Protón Vacuolares/genética
6.
Mol Pharm ; 21(6): 2993-3005, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38722865

RESUMEN

The susceptibility of lysosomal membranes in tumor cells to cationic amphiphilic drugs (CADs) enables CADs to induce lysosomal membrane permeabilization (LMP) and trigger lysosome-dependent cell death (LDCD), suggesting a potential antitumor therapeutic approach. However, the existence of intrinsic lysosomal damage response mechanisms limits the display of the pharmacological activity of CADs. In this study, we report that low concentrations of QS-21, a saponin with cationic amphiphilicity extracted from Quillaja Saponaria tree, can induce LMP but has nontoxicity to tumor cells. QS-21 and MAP30, a type I ribosome-inactivating protein, synergistically induce apoptosis in tumor cells at low concentrations of both. Mechanistically, QS-21-induced LMP helps MAP30 escape from endosomes or lysosomes and subsequently enter the endoplasmic reticulum, where MAP30 downregulates the expression of autophagy-associated LC3 proteins, thereby inhibiting lysophagy. The inhibition of lysophagy results in the impaired clearance of damaged lysosomes, leading to the leakage of massive lysosomal contents such as cathepsins into the cytoplasm, ultimately triggering LDCD. In summary, our study showed that coadministration of QS-21 and MAP30 amplified the lysosomal disruption and can be a new synergistic LDCD-based antitumor therapy.


Asunto(s)
Antineoplásicos , Apoptosis , Autofagia , Lisosomas , Proteínas Inactivadoras de Ribosomas Tipo 1 , Saponinas , Animales , Humanos , Ratones , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Línea Celular Tumoral , Sinergismo Farmacológico , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Quillaja/química , Proteínas Inactivadoras de Ribosomas Tipo 1/farmacología , Saponinas/farmacología
7.
Cell Mol Biol Lett ; 29(1): 116, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39237893

RESUMEN

Lysosomes are acidic organelles involved in crucial intracellular functions, including the degradation of organelles and protein, membrane repair, phagocytosis, endocytosis, and nutrient sensing. Given these key roles of lysosomes, maintaining their homeostasis is essential for cell viability. Thus, to preserve lysosome integrity and functionality, cells have developed a complex intracellular system, called lysosome quality control (LQC). Several stressors may affect the integrity of lysosomes, causing Lysosomal membrane permeabilization (LMP), in which membrane rupture results in the leakage of luminal hydrolase enzymes into the cytosol. After sensing the damage, LQC either activates lysosome repair, or induces the degradation of the ruptured lysosomes through autophagy. In addition, LQC stimulates the de novo biogenesis of functional lysosomes and lysosome exocytosis. Alterations in LQC give rise to deleterious consequences for cellular homeostasis. Specifically, the persistence of impaired lysosomes or the malfunctioning of lysosomal processes leads to cellular toxicity and death, thereby contributing to the pathogenesis of different disorders, including neurodegenerative diseases (NDs). Recently, several pieces of evidence have underlined the importance of the role of lysosomes in NDs. In this review, we describe the elements of the LQC system, how they cooperate to maintain lysosome homeostasis, and their implication in the pathogenesis of different NDs.


Asunto(s)
Lisosomas , Enfermedades Neurodegenerativas , Lisosomas/metabolismo , Humanos , Enfermedades Neurodegenerativas/metabolismo , Animales , Homeostasis , Autofagia
8.
Cell Mol Life Sci ; 80(6): 160, 2023 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-37210406

RESUMEN

We previously reported that permanent ischemia induces marked dysfunction of the autophagy-lysosomal pathway (ALP) in rats, which is possibly mediated by the transcription factor EB (TFEB). However, it is still unclear whether signal transducer and activator of transcription 3 (STAT3) is responsible for the TFEB-mediated dysfunction of ALP in ischemic stroke. In the present study, we used AAV-mediated genetic knockdown and pharmacological blockade of p-STAT3 to investigate the role of p-STAT3 in regulating TFEB-mediated ALP dysfunction in rats subjected to permanent middle cerebral occlusion (pMCAO). The results showed that the level of p-STAT3 (Tyr705) in the rat cortex increased at 24 h after pMCAO and subsequently led to lysosomal membrane permeabilization (LMP) and ALP dysfunction. These effects can be alleviated by inhibitors of p-STAT3 (Tyr705) or by STAT3 knockdown. Additionally, STAT3 knockdown significantly increased the nuclear translocation of TFEB and the transcription of TFEB-targeted genes. Notably, TFEB knockdown markedly reversed STAT3 knockdown-mediated improvement in ALP function after pMCAO. This is the first study to show that the contribution of p-STAT3 (Tyr705) to ALP dysfunction may be partly associated with its inhibitory effect on TFEB transcriptional activity, which further leads to ischemic injury in rats.


Asunto(s)
Autofagia , Factor de Transcripción STAT3 , Animales , Ratas , Autofagia/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Isquemia/metabolismo , Lisosomas/metabolismo , Fosforilación , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo
9.
Ecotoxicol Environ Saf ; 274: 116195, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38479315

RESUMEN

Fluoride is known to induce nephrotoxicity; however, the underlying mechanisms remain incompletely understood. Therefore, this study aims to explore the roles and mechanisms of lysosomal membrane permeabilization (LMP) and the GSDME/HMGB1 axis in fluoride-induced nephrotoxicity and the protective effects of rutin. Rutin, a naturally occurring flavonoid compound known for its antioxidative and anti-inflammatory properties, is primarily mediated by inhibiting oxidative stress and reducing proinflammatory markers. To that end, we established in vivo and in vitro models. In the in vivo study, rats were exposed to sodium fluoride (NaF) throughout pregnancy and up until 2 months after birth. In parallel, we employed in vitro models using HK-2 cells treated with NaF, n-acetyl-L-cysteine (NAC), or rutin. We assessed lysosomal permeability through immunofluorescence and analyzed relevant protein expression via western blotting. Our findings showed that NaF exposure increased ROS levels, resulting in enhanced LMP and increased cathepsin B (CTSB) and D (CTSD) expression. Furthermore, the exposure to NaF resulted in the upregulation of cleaved PARP1, cleaved caspase-3, GSDME-N, and HMGB1 expressions, indicating cell death and inflammation-induced renal damage. Rutin mitigates fluoride-induced nephrotoxicity by suppressing ROS-mediated LMP and the GSDME/HMGB1 axis, ultimately preventing fluoride-induced renal toxicity occurrence and development. In conclusion, our findings suggest that NaF induces renal damage through ROS-mediated activation of LMP and the GSDME/HMGB1 axis, leading to pyroptosis and inflammation. Rutin, a natural antioxidative and anti-inflammatory dietary supplement, offers a novel approach to prevent and treat fluoride-induced nephrotoxicity.


Asunto(s)
Fluoruros , Proteína HMGB1 , Enfermedades Renales , Rutina , Animales , Ratas , Antiinflamatorios/farmacología , Antioxidantes/metabolismo , Caspasa 3/metabolismo , Fluoruros/metabolismo , Fluoruros/toxicidad , Proteína HMGB1/efectos de los fármacos , Proteína HMGB1/metabolismo , Inflamación/metabolismo , Lisosomas/efectos de los fármacos , Piroptosis/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Especies Reactivas de Oxígeno/toxicidad , Rutina/farmacología , Fluoruro de Sodio/toxicidad , Enfermedades Renales/inducido químicamente , Enfermedades Renales/tratamiento farmacológico , Gasderminas/efectos de los fármacos , Gasderminas/metabolismo
10.
Environ Toxicol ; 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39031462

RESUMEN

In sepsis, bacterial components, particularly lipopolysaccharide (LPS), trigger organ injuries such as liver dysfunction. Although sepsis induces hepatocyte damage, the mechanisms underlying sepsis-related hepatic failure remain unclear. In this study, we demonstrated that the LPS-treated rat hepatocyte cell line Clone 9 not only induced reactive oxygen species (ROS) generation and apoptosis but also increased the expression of the autophagy marker proteins LC3-II and p62, and decreased the expression of intact Lamp2A, a lysosomal membrane protein. Additionally, LPS increased lysosomal membrane permeability and galectin-3 puncta formation, and promoted lysosomal alkalization in Clone 9 cells. Pharmacological inhibition of caspase-8 and cathepsin D (CTSD) suppressed the activation of caspase-3 and rescued the viability of LPS-treated Clone 9 cells. Furthermore, LPS induced CTSD release associated with lysosomal leakage and contributed to caspase-8 activation. Pretreatment with the antioxidant N-acetylcysteine (NAC) not only diminished ROS generation and increased the cell survival rate, but also decreased the expression of activated caspase-8 and caspase-3 and increased the protein level of Lamp2A in LPS-treated Clone 9 cells. These results demonstrate that LPS-induced ROS causes lysosomal membrane permeabilization and lysosomal cell death, which may play a crucial role in hepatic failure in sepsis. Our results may facilitate the development of new strategies for sepsis management.

11.
Nano Lett ; 23(23): 10657-10666, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-38018769

RESUMEN

CaO2 nanoparticles (CNPs) can produce toxic Ca2+ and H2O2 under acidic pH, which accounts for their intrinsic anticancer activity but at the same time raises safety concerns upon systemic exposure. Simultaneously realizing minimized Ca2+/H2O2 production and enhanced anticancer activity poses a dilemma. Herein, we introduce a "crystallinity gradient-based selective etching" (CGSE) strategy, which is realized by creating a crystallinity gradient in a CNP formed by self-assembled nanocrystals. The nanocrystals distributed in the outer layer have a higher crystallinity and thus are chemically more robust than those distributed in the inner layer, which can be selectively etched. CGSE not only leads to CNPs with tailored single- and double-shell hollow structures and metal-doped compositions but more surprisingly enables significantly enhanced anticancer activity as well as tumor growth inhibition under limited Ca2+/H2O2 production, which is attributed to an alkalinity-reinforced lysosome-dependent cell death pathway.


Asunto(s)
Nanopartículas , Nanoestructuras , Neoplasias , Humanos , Peróxido de Hidrógeno/metabolismo , Nanoestructuras/química , Neoplasias/tratamiento farmacológico , Nanopartículas/química
12.
J Cell Physiol ; 238(2): 287-305, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36502521

RESUMEN

Recent developments in lysosome biology have transformed our view of lysosomes from static garbage disposals that can also act as suicide bags to decidedly dynamic multirole adaptive operators of cellular homeostasis. Lysosome-governed signaling pathways, proteins, and transcription factors equilibrate the rate of catabolism and anabolism (autophagy to lysosomal biogenesis and metabolite pool maintenance) by sensing cellular metabolic status. Lysosomes also interact with other organelles by establishing contact sites through which they exchange cellular contents. Lysosomal function is critically assessed by lysosomal positioning and motility for cellular adaptation. In this setting, mechanistic target of rapamycin kinase (MTOR) is the chief architect of lysosomal signaling to control cellular homeostasis. Notably, lysosomes can orchestrate explicit cell death mechanisms, such as autophagic cell death and lysosomal membrane permeabilization-associated regulated necrotic cell death, to maintain cellular homeostasis. These lines of evidence emphasize that the lysosomes serve as a central signaling hub for cellular homeostasis.


Asunto(s)
Apoptosis , Transducción de Señal , Humanos , Supervivencia Celular , Homeostasis/fisiología , Transducción de Señal/fisiología , Lisosomas/metabolismo , Autofagia/fisiología
13.
Chembiochem ; 24(24): e202300579, 2023 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-37869939

RESUMEN

Lipidation of the LC3 protein has frequently been employed as a marker of autophagy. However, LC3-lipidation is also triggered by stimuli not related to canonical autophagy. Therefore, characterization of the driving parameters for LC3 lipidation is crucial to understanding the biological roles of LC3. We identified a pseudo-natural product, termed Inducin, that increases LC3 lipidation independently of canonical autophagy, impairs lysosomal function and rapidly recruits Galectin 3 to lysosomes. Inducin treatment promotes Endosomal Sorting Complex Required for Transport (ESCRT)-dependent membrane repair and transcription factor EB (TFEB)-dependent lysosome biogenesis ultimately leading to cell death.


Asunto(s)
Autofagia , Lisosomas , Transporte Biológico , Galectina 3 , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo
14.
Int J Mol Sci ; 24(4)2023 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-36835418

RESUMEN

Costunolide (CTL), an active compound isolated from Saussurea lappa Clarke and Laurus nobilis L, has been shown to induce apoptosis via reactive oxygen species (ROS) generation in various types of cancer cells. However, details of molecular mechanisms underlying the difference in sensitivity of cancer cells to CTL are still largely unknown. Here, we tested the effect of CTL on the viability of breast cancer cells and found that CTL had a more efficient cytotoxic effect against SK-BR-3 cells than MCF-7 cells. Mechanically, ROS levels were significantly increased upon CTL treatment only in SK-BR-3 cells, which leads to lysosomal membrane permeabilization (LMP) and cathepsin D release, and subsequent activation of the mitochondrial-dependent intrinsic apoptotic pathway by inducing mitochondrial outer membrane permeabilization (MOMP). In contrast, treatment of MCF-7 cells with CTL activated PINK1/Parkin-dependent mitophagy to remove damaged mitochondria, which prevented the elevation of ROS levels, thereby contributing to their reduced sensitivity to CTL. These results suggest that CTL is a potent anti-cancer agent, and its combination with the inhibition of mitophagy could be an effective method for treating breast cancer cells that are less sensitive to CTL.


Asunto(s)
Antineoplásicos Fitogénicos , Neoplasias de la Mama , Resistencia a Antineoplásicos , Femenino , Humanos , Apoptosis , Neoplasias de la Mama/metabolismo , Mitocondrias/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Antineoplásicos Fitogénicos/farmacología
15.
Molecules ; 28(4)2023 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-36838702

RESUMEN

Cationic, water-soluble benzophenothiaziniums have been recognized as effective type I photosensitizers (PSs) against hypoxic tumor cells. However, the study of the structure-property relationship of this type of PS is still worth further exploration to achieve optimized photodynamic effects and minimize the potential side effects. Herein, we synthesized a series of benzophenothiazine derivatives with minor N-alkyl alteration to study the effects on the structure-property relationships. The cellular uptake, subcellular organelle localization, reactive oxygen species (ROS) generation, and photocytotoxicity performances were systematically investigated. NH2NBS and EtNBS specifically localized in lysosomes and exhibited high toxicity under light with a moderate phototoxicity index (PI) due to the undesirable dark toxicity. However, NMe2NBS with two methyl substitutions accumulated more in mitochondria and displayed an excellent PI value with moderate light toxicity and negligible dark toxicity. Without light irradiation, NH2NBS and EtNBS could induce lysosomal membrane permeabilization (LMP), while NMe2NBS showed no obvious damage to lysosomes. After irradiation, NH2NBS and EtNBS were released from lysosomes and relocated into mitochondria. All compounds could induce mitochondria membrane potential (MMP) loss and nicotinamide adenine dinucleotide phosphate (NADPH) consumption under light to cause cell death. NMe2NBS exhibited remarkable in vivo photodynamic therapy (PDT) efficacy in a xenograft mouse tumor (inhibition rate, 89%) with no obvious side effects. This work provides a valuable methodology to investigate the structure-property relationships of benzophenothiazine dyes, which is of great importance in the practical application of PDT against hypoxia tumor cells.


Asunto(s)
Fotoquimioterapia , Fármacos Fotosensibilizantes , Humanos , Animales , Ratones , Fármacos Fotosensibilizantes/farmacología , Fenotiazinas , Alquilación , Fotoquimioterapia/métodos , Línea Celular Tumoral
16.
Ecotoxicol Environ Saf ; 248: 114333, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36446170

RESUMEN

PM2.5 exposure can be associated with the onset of neurodegenerative diseases, with oxidative stress-induced cellular homeostasis disruption and cell death as one of the main mechanisms. However, the exact cellular and molecular processes are still rarely investigated. Autophagy and KEAP1-NRF2 (Kelch-like ECH-Associating protein 1-nuclear factor erythroid 2 related factor 2) signaling pathway are two main cellular defense systems for maintaining cellular homeostasis and resisting oxidative stress. In this study, we primarily investigated the role of autophagy and KEAP1-NRF2 in regulating cell death resulting from PM2.5 exposure in mouse neuroblastoma N2a cells. Our results showed that PM2.5 exposure disrupted autophagic flux by impairing lysosomal function, including lysosomal alkalinization, increased lysosome membrane permeabilization (LMP), and Cathepsin B release. Furthermore, dysregulated autophagy enhances NRF2 activity in a p62-dependent manner, which then initiates the expression of a series of antioxidant genes and increases cellular insensitivity to ferroptosis. Meanwhile, autophagy dysfunction impairs the intracellular degradation of ferroptosis related proteins such as GPX4 and ferritin. As these proteins accumulate, cells also become less sensitive to ferroptosis. LMP-associated cell death may be the main mechanism of PM2.5-induced N2a cytotoxicity. Our results may provide insights into the mechanisms of PM2.5-induced neurotoxicity and predict effective prevention and treatment strategies.


Asunto(s)
Ferroptosis , Animales , Ratones , Proteína 1 Asociada A ECH Tipo Kelch , Factor 2 Relacionado con NF-E2/genética , Lisosomas , Muerte Celular , Autofagia , Material Particulado/toxicidad
17.
Cancer Sci ; 112(8): 3324-3337, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34051014

RESUMEN

Cancer cells use autophagy for growth, survival, and cytoprotection from chemotherapy. Therefore, autophagy inhibitors appear to be good candidates for cancer treatment. Our group previously reported that macrolide antibiotics, especially azithromycin (AZM), have potent autophagy inhibitory effects, and combination treatment with tyrosine kinase inhibitors or proteasome inhibitors enhances their anti-cancer activity. In this study, we evaluated the effect of combination therapy with DNA-damaging drugs and AZM in non-small-cell lung cancer (NSCLC) cells. We found that the cytotoxic activities of DNA-damaging drugs, such as doxorubicin (DOX), etoposide, and carboplatin, were enhanced in the presence of AZM in NSCLC cell lines, whereas AZM alone exhibited almost no cytotoxicity. This enhanced cell death was dependent on wild-type-p53 status and autophagosome-forming ability because TP53 knockout (KO) and ATG5-KO cells attenuated AZM-enhanced cytotoxicity. DOX treatment upregulated lysosomal biogenesis by activating TFEB and led to lysosomal membrane damage as assessed by galectin 3 puncta assay and cytoplasmic leakage of lysosomal enzymes. In contrast, AZM treatment blocked autophagy, which resulted in the accumulation of lysosomes/autolysosomes. Thus, the effects of DOX and AZM were integrated into the marked increase in damaged lysosomes/autolysosomes, leading to prominent lysosomal membrane permeabilization (LMP) for apoptosis induction. Our data suggest that concomitant treatment with DNA-damaging drugs and AZM is a promising strategy for NSCLC treatment via pronounced LMP induction.


Asunto(s)
Azitromicina/farmacología , Carboplatino/farmacología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Neoplasias Pulmonares/metabolismo , Lisosomas/metabolismo , Inhibidores de Topoisomerasa II/farmacología , Células A549 , Autofagia/efectos de los fármacos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Línea Celular Tumoral , Permeabilidad de la Membrana Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Daño del ADN , Sinergismo Farmacológico , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Lisosomas/efectos de los fármacos
18.
EMBO J ; 36(2): 135-150, 2017 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-27753622

RESUMEN

Rupture of endosomes and lysosomes is a major cellular stress condition leading to cell death and degeneration. Here, we identified an essential role for the ubiquitin-directed AAA-ATPase, p97, in the clearance of damaged lysosomes by autophagy. Upon damage, p97 translocates to lysosomes and there cooperates with a distinct set of cofactors including UBXD1, PLAA, and the deubiquitinating enzyme YOD1, which we term ELDR components for Endo-Lysosomal Damage Response. Together, they act downstream of K63-linked ubiquitination and p62 recruitment, and selectively remove K48-linked ubiquitin conjugates from a subpopulation of damaged lysosomes to promote autophagosome formation. Lysosomal clearance is also compromised in MEFs harboring a p97 mutation that causes inclusion body myopathy and neurodegeneration, and damaged lysosomes accumulate in affected patient tissue carrying the mutation. Moreover, we show that p97 helps clear late endosomes/lysosomes ruptured by endocytosed tau fibrils. Thus, our data reveal an important mechanism of how p97 maintains lysosomal homeostasis, and implicate the pathway as a modulator of degenerative diseases.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Autofagia , Proteínas Portadoras/metabolismo , Proteínas de Ciclo Celular/metabolismo , Endopeptidasas/metabolismo , Lisosomas/metabolismo , Proteínas/metabolismo , Tioléster Hidrolasas/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Proteínas Adaptadoras del Transporte Vesicular , Animales , Proteínas Relacionadas con la Autofagia , Células Cultivadas , Humanos , Ratones , Proteína que Contiene Valosina
19.
FASEB J ; 34(9): 12932-12945, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-33000523

RESUMEN

We previously demonstrated that Tetraticopeptide 4 (TTC4) inhibited apoptosis in vascular endothelial cells (VEC) deprived of serum and fibroblast growth factor 2 (FGF-2). In this study, we aimed to resolve the mechanism of TTC4 inhibiting VEC apoptosis. TTC4, predicted as a HSP70 co-chaperone protein, may regulate the fate of cells by affecting the activity of HSP70, however, there is no experimental evidence showing the interaction of TTC4 and HSP70. Using Co-immunoprecipitation (Co-IP), we demonstrated that TTC4 interacted with HSP70. If HSP70 was knockdown, TTC4 no longer suppressed apoptosis. Furthermore, we found ABO, an inhibitor of annexin A7 (ANXA7) GTPase, could promote the interaction of TTC4 and HSP70 and the translocation of ANXA7 to lysosome. At the same time, ABO inhibited the interaction of HSP70 and ANXA7. Moreover, Akt, as a downstream effector of HSP70 was upregulated, and ANXA7 translocating to lysosome protected the stability of lysosomal membrane. Here, we discovered a special mechanism by which TTC4 inhibited apoptosis via HSP70 in VECs. On the one hand, increasing TTC4 and HSP70 interaction upregulated Akt that inhibited apoptosis. On the other hand, decreasing HSP70 and ANXA7 interaction promoted the translocation of ANXA7 to lysosome, which inhibited apoptosis through protecting the lysosomal membrane stability.


Asunto(s)
Anexina A7/metabolismo , Apoptosis , Proteínas HSP70 de Choque Térmico/metabolismo , Células Endoteliales de la Vena Umbilical Humana/citología , Lisosomas/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Humanos , Unión Proteica , Proteínas Proto-Oncogénicas c-akt/metabolismo
20.
Angew Chem Int Ed Engl ; 60(40): 21807-21816, 2021 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-34189812

RESUMEN

Here we report on the design, synthesis, and assembly of an enzymatic programmable peptide system inspired by endocytic processes to induce molecular assemblies formation spatiotemporally in living cancer cells, resulting in glioblastoma cell death mainly in necroptosis. Our results indicate the stability and glycosylation of molecules play an essential role in determining the final bioactivity. Detailed mechanistic studies by CLSM, Flow cytometry, western blot, and Bio-EM suggest the site-specific formation of assemblies, which could induce the LMP and activate the downstream cell death pathway. Moreover, we also demonstrate that our strategy can boost the activity of commercial chemotherapy drug by escaping lysosome sequestration. We expected this work would be expanded towards artificial intelligent biomaterials for cancer therapy and imaging precisely.


Asunto(s)
Antineoplásicos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Sustancias Macromoleculares/síntesis química , Sustancias Macromoleculares/química , Sustancias Macromoleculares/farmacología , Estructura Molecular
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