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1.
Int J Med Sci ; 21(9): 1629-1639, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39006843

RESUMO

The complete molecular mechanism underlying doxorubicin-induced cardiomyopathy remains incompletely elucidated. In this investigation, we engineered mice with cardiomyocyte-specific sorting nexin 3 knockout (SNX3Cko ) to probe the potential protective effects of SNX3 ablation on doxorubicin-triggered myocardial injury, focusing on GPX4-dependent ferroptosis. Our findings indicate that SNX3 deletion normalized heart contractile/relaxation function and thwarted the escalation of cardiac injury biomarkers following doxorubicin exposure. Additionally, SNX3 deletion in the heart mitigated the inflammatory response and oxidative stress in the presence of doxorubicin. At the molecular level, the detrimental effects of doxorubicin-induced cell death, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction were alleviated by SNX3 deficiency. Molecular analysis revealed the activation of GPX4-mediated ferroptosis by doxorubicin, whereas loss of SNX3 prevented the initiation of GPX4-dependent ferroptosis. Furthermore, treatment with erastin, a ferroptosis inducer, markedly reduced cell viability, exacerbated ER stress, and induced mitochondrial dysfunction in SNX3-depleted cardiomyocytes upon doxorubicin exposure. In summary, our results demonstrate that SNX3 deficiency shielded the heart from doxorubicin-induced myocardial dysfunction by modulating GPX4-associated ferroptosis.


Assuntos
Cardiomiopatias , Doxorrubicina , Ferroptose , Camundongos Knockout , Miócitos Cardíacos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Nexinas de Classificação , Ferroptose/efeitos dos fármacos , Ferroptose/genética , Animais , Doxorrubicina/efeitos adversos , Doxorrubicina/toxicidade , Cardiomiopatias/induzido quimicamente , Cardiomiopatias/patologia , Cardiomiopatias/genética , Nexinas de Classificação/genética , Nexinas de Classificação/metabolismo , Camundongos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Humanos , Estresse Oxidativo/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos
2.
Sci Rep ; 14(1): 13093, 2024 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849490

RESUMO

Sorting nexin 16 (SNX16), a pivotal sorting nexin, emerges in tumor progression complexity, fueling research interest. However, SNX16's biological impact and molecular underpinnings in hepatocellular carcinoma (HCC) remain elusive. This study probes SNX16's function, clinical relevance via mRNA, and protein expression in HCC. Overexpression/knockdown assays of SNX16 were employed to elucidate impacts on HCC cell invasion, proliferation, and EMT. Additionally, the study delved into SNX16's regulation of the EGFR-AKT signaling cascade mechanism. SNX16 overexpression in HCC correlates with poor patient survival; enhancing proliferation, migration, invasion, and tumorigenicity, while SNX16 knockdown suppresses these processes. SNX16 downregulation curbs phospho-EGFR, dampening AKT signaling. EGFR suppression counters SNX16-overexpression-induced HCC proliferation, motility, and invasiveness. Our findings delineate SNX16's regulatory role in HCC, implicating it as a prospective therapeutic target.


Assuntos
Carcinoma Hepatocelular , Movimento Celular , Proliferação de Células , Receptores ErbB , Neoplasias Hepáticas , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Nexinas de Classificação , Animais , Humanos , Camundongos , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/mortalidade , Linhagem Celular Tumoral , Movimento Celular/genética , Transição Epitelial-Mesenquimal/genética , Receptores ErbB/metabolismo , Receptores ErbB/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/mortalidade , Invasividade Neoplásica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Nexinas de Classificação/metabolismo , Nexinas de Classificação/genética
3.
J Cell Sci ; 137(13)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38884339

RESUMO

Early endosomes sort transmembrane cargo either for lysosomal degradation or retrieval to the plasma membrane or the Golgi complex. Endosomal retrieval in eukaryotes is governed by the anciently homologous retromer or retriever complexes. Each comprises a core tri-protein subcomplex, membrane-deformation proteins and interacting partner complexes, together retrieving a variety of known cargo proteins. Trichomonas vaginalis, a sexually transmitted human parasite, uses the endomembrane system for pathogenesis. It has massively and selectively expanded its endomembrane protein complement, the evolutionary path of which has been largely unexplored. Our molecular evolutionary study of retromer, retriever and associated machinery in parabasalids and its free-living sister lineage of Anaeramoeba demonstrates specific expansion of the retromer machinery, contrasting with the retriever components. We also observed partial loss of the Commander complex and sorting nexins in Parabasalia but complete retention in Anaeramoeba. Notably, we identified putative parabasalid sorting nexin analogs. Finally, we report the first retriever protein localization in a non-metazoan group along with retromer protein localization in T. vaginalis.


Assuntos
Endossomos , Endossomos/metabolismo , Transporte Proteico , Trichomonas vaginalis/metabolismo , Trichomonas vaginalis/genética , Filogenia , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/genética , Evolução Molecular , Humanos , Complexo de Golgi/metabolismo , Nexinas de Classificação/metabolismo , Nexinas de Classificação/genética , Animais
4.
Biosci Rep ; 44(6)2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38836326

RESUMO

Cumulative research findings support the idea that endocytic trafficking is crucial in regulating receptor signaling and associated diseases. Specifically, strong evidence points to the involvement of sorting nexins (SNXs), particularly SNX1 and SNX2, in the signaling and trafficking of the receptor tyrosine kinase (RTK) MET in colorectal cancer (CRC). Activation of hepatocyte growth factor (HGF) receptor MET is a key driver of CRC progression. In the present study, we utilized human HCT116 CRC cells with SNX1 and SNX2 genes knocked out to demonstrate that their absence leads to a delay in MET entering early endosomes. This delay results in increased phosphorylation of both MET and AKT upon HGF stimulation, while ERK1/2 (extracellular signal-regulated kinases 1 and 2) phosphorylation remains unaffected. Despite these changes, HGF-induced cell proliferation, scattering, and migration remain similar between the parental and the SNX1/2 knockout cells. However, in the absence of SNX1 and SNX2, these cells exhibit increased resistance to TRAIL-induced apoptosis. This research underscores the intricate relationship between intracellular trafficking, receptor signaling, and cellular responses and demonstrates for the first time that the modulation of MET trafficking by SNX1 and SNX2 is critical for receptor signaling that may exacerbate the disease.


Assuntos
Movimento Celular , Proliferação de Células , Neoplasias Colorretais , Fator de Crescimento de Hepatócito , Proteínas Proto-Oncogênicas c-met , Nexinas de Classificação , Humanos , Nexinas de Classificação/metabolismo , Nexinas de Classificação/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Proteínas Proto-Oncogênicas c-met/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Neoplasias Colorretais/genética , Células HCT116 , Fator de Crescimento de Hepatócito/metabolismo , Transdução de Sinais , Fosforilação , Endossomos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transporte Proteico
5.
Cancer Lett ; 592: 216953, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38729557

RESUMO

TGFBR2, a key regulator of the TGFß signaling pathway, plays a crucial role in gastric cancer (GC) metastasis through its endosomal recycling process. Despite its importance, the mechanisms governing this process remain unclear. Here, we identify integrin ß5 (ITGB5) as a critical mediator that promotes TGFBR2 endosomal recycling. Our study reveals elevated expression of ITGB5 in GC, particularly in metastatic cases, correlating with poor patient outcomes. Knockdown of ITGB5 impairs GC cell metastasis both in vitro and in vivo. Mechanistically, ITGB5 facilitates epithelial-mesenchymal transition mediated by TGFß signaling, thereby enhancing GC metastasis. Acting as a scaffold, ITGB5 interacts with TGFBR2 and SNX17, facilitating SNX17-mediated endosomal recycling of TGFBR2 and preventing lysosomal degradation, thereby maintaining its surface distribution on tumor cells. Notably, TGFß signaling directly upregulates ITGB5 expression, establishing a positive feedback loop that exacerbates GC metastasis. Our findings shed light on the role of ITGB5 in promoting GC metastasis through SNX17-mediated endosomal recycling of TGFBR2, providing insights for the development of targeted cancer therapies.


Assuntos
Endossomos , Transição Epitelial-Mesenquimal , Receptor do Fator de Crescimento Transformador beta Tipo II , Transdução de Sinais , Neoplasias Gástricas , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Endossomos/metabolismo , Regulação Neoplásica da Expressão Gênica , Cadeias beta de Integrinas/metabolismo , Cadeias beta de Integrinas/genética , Metástase Neoplásica , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Receptor do Fator de Crescimento Transformador beta Tipo II/metabolismo , Nexinas de Classificação/genética , Nexinas de Classificação/metabolismo , Neoplasias Gástricas/patologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Fator de Crescimento Transformador beta/metabolismo
6.
Biophys Chem ; 310: 107255, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38728808

RESUMO

In solution NMR, chemical shift perturbation (CSP) experiments are widely employed to study intermolecular interactions. However, excluding the nonsignificant peak shift is difficult because little is known about errors in CSP. Here, to address this issue, we introduce a method for estimating errors in CSP based on the noise level. First, we developed a technique that involves line shape fitting to estimate errors in peak position via Monte Carlo simulations. Second, this technique was applied to estimate errors in CSP. In intermolecular interaction analysis of VAP-A with SNX2, error estimation of CSP enabled the evaluation of small but significant changes in peak position and yielded detailed insights that are unattainable with conventional CSP analysis. Third, this technique was successfully applied to estimate errors in residual dipolar couplings. In conclusion, our error estimation method improves CSP analysis by excluding the nonsignificant peak shift.


Assuntos
Método de Monte Carlo , Nexinas de Classificação/química , Ressonância Magnética Nuclear Biomolecular , Espectroscopia de Ressonância Magnética/métodos
7.
Int J Mol Sci ; 25(7)2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38612903

RESUMO

Proteins of the sorting nexin (SNX) family present a modular structural architecture with a phox homology (PX) phosphoinositide (PI)-binding domain and additional PX structural domains, conferring to them a wide variety of vital eukaryotic cell's functions, from signal transduction to membrane deformation and cargo binding. Although SNXs are well studied in human and yeasts, they are poorly investigated in protists. Herein, is presented the characterization of the first SNX identified in Leishmania protozoan parasites encoded by the LdBPK_352470 gene. In silico secondary and tertiary structure prediction revealed a PX domain on the N-terminal half and a Bin/amphiphysin/Rvs (BAR) domain on the C-terminal half of this protein, with these features classifying it in the SNX-BAR subfamily of SNXs. We named the LdBPK_352470.1 gene product LdSNXi, as it is the first SNX identified in Leishmania (L.) donovani. Its expression was confirmed in L. donovani promastigotes under different cell cycle phases, and it was shown to be secreted in the extracellular medium. Using an in vitro lipid binding assay, it was demonstrated that recombinant (r) LdSNXi (rGST-LdSNXi) tagged with glutathione-S-transferase (GST) binds to the PtdIns3P and PtdIns4P PIs. Using a specific a-LdSNXi antibody and immunofluorescence confocal microscopy, the intracellular localization of endogenous LdSNXi was analyzed in L. donovani promastigotes and axenic amastigotes. Additionally, rLdSNXi tagged with enhanced green fluorescent protein (rLdSNXi-EGFP) was heterologously expressed in transfected HeLa cells and its localization was examined. All observed localizations suggest functions compatible with the postulated SNX identity of LdSNXi. Sequence, structure, and evolutionary analysis revealed high homology between LdSNXi and the human SNX2, while the investigation of protein-protein interactions based on STRING (v.11.5) predicted putative molecular partners of LdSNXi in Leishmania.


Assuntos
Leishmania , Humanos , Leishmania/genética , Células HeLa , Nexinas de Classificação/genética , Transdução de Sinais , Anticorpos , Glutationa Transferase
8.
J Cell Sci ; 137(9)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38606629

RESUMO

The ADP-ribosylation factors (ARFs) and ARF-like (ARL) GTPases serve as essential molecular switches governing a wide array of cellular processes. In this study, we used proximity-dependent biotin identification (BioID) to comprehensively map the interactome of 28 out of 29 ARF and ARL proteins in two cellular models. Through this approach, we identified ∼3000 high-confidence proximal interactors, enabling us to assign subcellular localizations to the family members. Notably, we uncovered previously undefined localizations for ARL4D and ARL10. Clustering analyses further exposed the distinctiveness of the interactors identified with these two GTPases. We also reveal that the expression of the understudied member ARL14 is confined to the stomach and intestines. We identified phospholipase D1 (PLD1) and the ESCPE-1 complex, more precisely, SNX1, as proximity interactors. Functional assays demonstrated that ARL14 can activate PLD1 in cellulo and is involved in cargo trafficking via the ESCPE-1 complex. Overall, the BioID data generated in this study provide a valuable resource for dissecting the complexities of ARF and ARL spatial organization and signaling.


Assuntos
Fatores de Ribosilação do ADP , Fosfolipase D , Transdução de Sinais , Fatores de Ribosilação do ADP/metabolismo , Fatores de Ribosilação do ADP/genética , Humanos , Fosfolipase D/metabolismo , Fosfolipase D/genética , Células HEK293 , Animais , Nexinas de Classificação/metabolismo , Nexinas de Classificação/genética , Mapeamento de Interação de Proteínas
9.
JCI Insight ; 9(10)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38625743

RESUMO

Dysregulated lipid homeostasis is emerging as a potential cause of neurodegenerative disorders. However, evidence of errors in lipid homeostasis as a pathogenic mechanism of neurodegeneration remains limited. Here, we show that cerebellar neurodegeneration caused by Sorting Nexin 14 (SNX14) deficiency is associated with lipid homeostasis defects. Recent studies indicate that SNX14 is an interorganelle lipid transfer protein that regulates lipid transport, lipid droplet (LD) biogenesis, and fatty acid desaturation, suggesting that human SNX14 deficiency belongs to an expanding class of cerebellar neurodegenerative disorders caused by altered cellular lipid homeostasis. To test this hypothesis, we generated a mouse model that recapitulates human SNX14 deficiency at a genetic and phenotypic level. We demonstrate that cerebellar Purkinje cells (PCs) are selectively vulnerable to SNX14 deficiency while forebrain regions preserve their neuronal content. Ultrastructure and lipidomic studies reveal widespread lipid storage and metabolism defects in SNX14-deficient mice. However, predegenerating SNX14-deficient cerebella show a unique accumulation of acylcarnitines and depletion of triglycerides. Furthermore, defects in LD content and telolysosome enlargement in predegenerating PCs suggest lipotoxicity as a pathogenic mechanism of SNX14 deficiency. Our work shows a selective cerebellar vulnerability to altered lipid homeostasis and provides a mouse model for future therapeutic studies.


Assuntos
Homeostase , Metabolismo dos Lipídeos , Células de Purkinje , Nexinas de Classificação , Nexinas de Classificação/metabolismo , Nexinas de Classificação/genética , Animais , Camundongos , Humanos , Células de Purkinje/metabolismo , Células de Purkinje/patologia , Modelos Animais de Doenças , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Doenças Neurodegenerativas/genética , Camundongos Knockout , Cerebelo/metabolismo , Cerebelo/patologia , Masculino , Gotículas Lipídicas/metabolismo
10.
Mol Biol Cell ; 35(6): ar76, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38598303

RESUMO

Endosomal coats incorporate membrane-binding subunits such as sorting nexin (SNX) proteins. The Saccharomyces cerevisiae SNX-BAR paralogs Vin1 and Vps5 are respective subunits of the endosomal VINE and retromer complexes whose dimerizing BAR domains are required for complex assembly and membrane association. However, a degree of promiscuity is predicted for yeast BAR-BAR pairings, and recent work has implicated the unstructured N-terminal domains of Vin1 and Vps5 in coat formation. Here, we map N-terminal signals in both SNX-BAR paralogs that contribute to the assembly and function of two distinct endosomal coats in vivo. Whereas Vin1 leverages a polybasic region and adjacent hydrophobic motif to bind Vrl1 and form VINE, the N-terminus of Vps5 interacts with the retromer subunit Vps29 at two sites, including a conserved hydrophobic pocket in Vps29 that engages other accessory proteins in humans. We also examined the sole isoform of Vps5 from the milk yeast Kluyveromyces lactis and found that ancestral yeasts may have used a nested N-terminal signal to form both VINE and retromer. Our results suggest that the specific assembly of Vps5-family SNX-BAR coats depends on inputs from unique N-terminal sequence features in addition to BAR domain coupling, expanding our understanding of endosomal coat biology.


Assuntos
Endossomos , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Nexinas de Classificação , Proteínas de Transporte Vesicular , Endossomos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Nexinas de Classificação/metabolismo , Nexinas de Classificação/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas de Transporte Vesicular/genética , Ligação Proteica , Domínios Proteicos , Humanos , Sequência de Aminoácidos
11.
Nat Commun ; 15(1): 2553, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38519472

RESUMO

Lysosomal Storage Disorders (LSDs), which share common phenotypes, including enlarged lysosomes and defective lysosomal storage, are caused by mutations in lysosome-related genes. Although gene therapies and enzyme replacement therapies have been explored, there are currently no effective routine therapies against LSDs. During lysosome reformation, which occurs when the functional lysosome pool is reduced, lysosomal lipids and proteins are recycled to restore lysosome functions. Here we report that the sorting nexin protein SNX8 promotes lysosome tubulation, a process that is required for lysosome reformation, and that loss of SNX8 leads to phenotypes characteristic of LSDs in human cells. SNX8 overexpression rescued features of LSDs in cells, and AAV-based delivery of SNX8 to the brain rescued LSD phenotypes in mice. Importantly, by screening a natural compound library, we identified three small molecules that enhanced SNX8-lysosome binding and reversed LSD phenotypes in human cells and in mice. Altogether, our results provide a potential solution for the treatment of LSDs.


Assuntos
Doenças por Armazenamento dos Lisossomos , Camundongos , Animais , Humanos , Doenças por Armazenamento dos Lisossomos/genética , Doenças por Armazenamento dos Lisossomos/terapia , Doenças por Armazenamento dos Lisossomos/metabolismo , Proteínas/metabolismo , Encéfalo/metabolismo , Mutação , Lisossomos/metabolismo , Nexinas de Classificação/genética , Nexinas de Classificação/metabolismo
12.
Anim Biotechnol ; 35(1): 2309956, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38315463

RESUMO

SNX29 is a potential functional gene associated with meat production traits. Previous studies have shown that SNX29 copy number variation (CNV) could be implicated with phenotype in goats. However, in Diannan small-ear (DSE) pigs, the genetic impact of SNX29 CNV on growth traits remains unclear. Therefore, this study investigated the associations between SNX29 CNVs (CNV10810 and CNV10811) and growth traits in 415 DSE pigs. The results revealed that the CNV10810 mutation was significantly associated with backfat thickness in DSE pigs at 12 and 15 months old (P < 0.05), while the CNV10811 mutation had significant effects on various growth traits at 6 and 12 months old, particularly for body weight, body height, back height and backfat thickness (P < 0.05 or P < 0.001). In conclusion, our results confirm that SNX29 CNV plays a role in regulating growth and development in pigs, thus suggesting its potential application for pig breeding programmes.


Assuntos
Variações do Número de Cópias de DNA , Nexinas de Classificação , Suínos/genética , Animais , Variações do Número de Cópias de DNA/genética , Nexinas de Classificação/genética , Fenótipo , Peso Corporal/genética , Dosagem de Genes
13.
Biochim Biophys Acta Biomembr ; 1866(4): 184305, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38408696

RESUMO

The proteolipid code determines how cytosolic proteins find and remodel membrane surfaces. Here, we investigate how this process works with sorting nexins Snx1 and Snx3. Both proteins form sorting machines by recognizing membrane zones enriched in phosphatidylinositol 3-phosphate (PI3P), phosphatidylserine (PS) and cholesterol. This co-localized combination forms a unique "lipid codon" or lipidon that we propose is responsible for endosomal targeting, as revealed by structures and interactions of their PX domain-based readers. We outline a membrane recognition and remodeling mechanism for Snx1 and Snx3 involving this code element alongside transmembrane pH gradients, dipole moment-guided docking and specific protein-protein interactions. This generates an initial membrane-protein assembly (memtein) that then recruits retromer and additional PX proteins to recruit cell surface receptors for sorting to the trans-Golgi network (TGN), lysosome and plasma membranes. Post-translational modification (PTM) networks appear to regulate how the sorting machines form and operate at each level. The commonalities and differences between these sorting nexins show how the proteolipid code orchestrates parallel flows of molecular information from ribosome emergence to organelle genesis, and illuminates a universally applicable model of the membrane.


Assuntos
Proteínas de Transporte , Proteínas de Transporte Vesicular , Proteínas de Transporte/química , Proteínas de Transporte Vesicular/metabolismo , Nexinas de Classificação/metabolismo , Transporte Proteico , Proteolipídeos/metabolismo
14.
J Cell Biol ; 223(3)2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38323995

RESUMO

In autophagy, autophagosomes deliver the lumenal contents to lysosomes for degradation via autophagosome-lysosome fusion. In contrast, autophagosome outer membrane components were recycled via autophagosomal components recycling (ACR), which is mediated by the recycler complex. The recycler complex, composed of SNX4, SNX5, and SNX17, cooperate with the dynein-dynactin complex to mediate ACR. However, how ACR is regulated remains unknown. Here, we found that Rab32 family proteins localize to autolysosomes and are required for ACR, rather than other autophagosomal or lysosomal Rab proteins. The GTPase activity of Rab32 family proteins, governed by their guanine nucleotide exchange factor and GTPase-activating protein, plays a key role in regulating ACR. This regulation occurs through the control of recycler complex formation, as well as the connection between the recycler-cargo and dynactin complex. Together, our study reveals an unidentified Rab32 family-dependent regulatory mechanism for ACR.


Assuntos
Autofagossomos , Dineínas , Proteínas Ativadoras de GTPase , Nexinas de Classificação , Proteínas rab de Ligação ao GTP , Humanos , Citoesqueleto de Actina/metabolismo , Autofagossomos/metabolismo , Complexo Dinactina/metabolismo , Dineínas/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Lisossomos , Proteínas rab de Ligação ao GTP/metabolismo
15.
Eur J Cell Biol ; 103(1): 151381, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38183814

RESUMO

The facultative intracellular pathogen Shigella flexneri invades non-phagocytic epithelial gut cells. Through a syringe-like apparatus called type 3 secretion system, it injects effector proteins into the host cell triggering actin rearrangements leading to its uptake within a tight vacuole, termed the bacterial-containing vacuole (BCV). Simultaneously, Shigella induces the formation of large vesicles around the entry site, which we refer to as infection-associated macropinosomes (IAMs). After entry, Shigella ruptures the BCV and escapes into the host cytosol by disassembling the BCV remnants. Previously, IAM formation has been shown to be required for efficient BCV escape, but the molecular events associated with BCV disassembly have remained unclear. To identify host components required for BCV disassembly, we performed a microscopy-based screen to monitor the recruitment of BAR domain-containing proteins, which are a family of host proteins involved in membrane shaping and sensing (e.g. endocytosis and recycling) during Shigella epithelial cell invasion. We identified endosomal recycling BAR protein Sorting Nexin-8 (SNX8) localized to IAMs in a PI(3)P-dependent manner before BCV disassembly. At least two distinct IAM subpopulations around the BCV were found, either being recycled back to cellular compartments such as the plasma membrane or transitioning to become RAB11A positive "contact-IAMs" involved in promoting BCV rupture. The IAM subpopulation duality was marked by the exclusive recruitment of either SNX8 or RAB11A. Hindering PI(3)P production at the IAMs led to an inhibition of SNX8 recruitment at these compartments and delayed both, the step of BCV rupture time and successful BCV disassembly. Finally, siRNA depletion of SNX8 accelerated BCV rupture and unpeeling of BCV remnants, indicating that SNX8 is involved in controlling the timing of the cytosolic release. Overall, our work sheds light on how Shigella establishes its intracellular niche through the subversion of a specific set of IAMs.


Assuntos
Fosfatos de Fosfatidilinositol , Shigella , Humanos , Shigella/fisiologia , Vacúolos/metabolismo , Células Epiteliais/fisiologia , Shigella flexneri/genética , Células HeLa , Nexinas de Classificação/metabolismo
16.
J Virol ; 98(1): e0159923, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38169281

RESUMO

African swine fever virus (ASFV) causes a highly contagious and deadly disease in domestic pigs and European wild boars, posing a severe threat to the global pig industry. ASFV CP204L, a highly immunogenic protein, is produced during the early stages of ASFV infection. However, the impact of CP204L protein-interacting partners on the outcome of ASFV infection is poorly understood. To accomplish this, coimmunoprecipitation and mass spectrometry analysis were conducted in ASFV-infected porcine alveolar macrophages (PAMs). We have demonstrated that sorting nexin 32 (SNX32) is a CP204L-binding protein and that CP204L interacted and colocalized with SNX32 in ASFV-infected PAMs. ASFV growth and replication were promoted by silencing SNX32 and suppressed by overexpressing SNX32. SNX32 degraded CP204L by recruiting the autophagy-related protein Ras-related protein Rab-1b (RAB1B). RAB1B overexpression inhibited ASFV replication, while knockdown of RAB1B had the opposite effect. Additionally, RAB1B, SNX32, and CP204L formed a complex upon ASFV infection. Taken together, this study demonstrates that SNX32 antagonizes ASFV growth and replication by recruiting the autophagy-related protein RAB1B. This finding extends our understanding of the interaction between ASFV CP204L and its host and provides new insights into exploring the relationship between ASFV infection and autophagy.IMPORTANCEAfrican swine fever (ASF) is a highly contagious and acute hemorrhagic viral disease with a high mortality near 100% in domestic pigs. ASF virus (ASFV), which is the only member of the family Asfarviridae, is a dsDNA virus of great complexity and size, encoding more than 150 proteins. Currently, there are no available vaccines against ASFV. ASFV CP204L represents the most abundantly expressed viral protein early in infection and plays an important role in regulating ASFV replication. However, the mechanism by which the interaction between ASFV CP204L and host proteins affects ASFV replication remains unclear. In this study, we demonstrated that the cellular protein SNX32 interacted with CP204L and degraded CP204L by upregulating the autophagy-related protein RAB1B. In summary, this study will help us understand the interaction mechanism between CP204L and its host upon infection and provide new insights for the development of vaccines and antiviral drugs.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Fatores de Restrição Antivirais , Autofagia , Nexinas de Classificação , Proteínas rab1 de Ligação ao GTP , Animais , Proteínas Relacionadas à Autofagia/metabolismo , Sus scrofa/virologia , Suínos/virologia , Nexinas de Classificação/metabolismo , Fatores de Restrição Antivirais/metabolismo , Proteínas rab1 de Ligação ao GTP/metabolismo , Macrófagos/virologia , Replicação Viral
17.
Mol Immunol ; 166: 79-86, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38271879

RESUMO

BACKGROUND: Liver ischemia reperfusion (IR) injury is a common cause of liver dysfunction in patients post liver partial resection and liver transplantation. However, the cellular defense mechanisms underlying IR are not well understood. Macrophage mediated sterile inflammation plays critical roles in liver IR injury. Sorting nexin (SNX) 10, a member of the SNX family which functions in regulation of endosomal sorting. This study aimed to explore the role of sorting nexin 10 (SNX10) during liver IR injury with a focus on regulating macrophage function. METHODS: Both the gene and protein expression levels of SNX10 were analyzed in human specimens from 10 patients undergoing liver partial resection with ischemic insult and in a mouse model of liver IR. The in vivo effects of SNX10 in liver IR injury and sterile inflammation in mice were investigated. Bone marrow derived macrophages (BMDMs) were used to determine the role of SNX10 in modulating macrophage function in vitro. RESULTS: Increased expression of SNX10 was observed both in human specimens and mice livers post IR. SNX10 knockdown alleviated IR induced sterile inflammation and liver damage in mice. SNX10 promoted M1 polarization of macrophage treated with LPS and facilitated inflammatory response by activating NLRP3 inflammasome. CONCLUSIONS: We report for the first time that SNX10 is upregulated in IR-stressed livers. SNX10 activation aggravates liver IR injury and sterile inflammation by facilitating macrophage M1 polarization and inflammatory response suggesting SNX10 as a potential therapeutic target for liver IR injury.


Assuntos
Inflamassomos , Traumatismo por Reperfusão , Humanos , Animais , Camundongos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Nexinas de Classificação/genética , Nexinas de Classificação/metabolismo , Fígado/metabolismo , Macrófagos/metabolismo , Inflamação/metabolismo , Traumatismo por Reperfusão/metabolismo
18.
Mol Neurobiol ; 61(3): 1346-1362, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37704928

RESUMO

Sorting nexin17 (SNX17) is a member of the sorting nexin family, which plays a crucial role in endosomal trafficking. Previous research has shown that SNX17 is involved in the recycling or degradation of various proteins associated with neurodevelopmental and neurological diseases in cell models. However, the significance of SNX17 in neurological function in the mouse brain has not been thoroughly investigated. In this study, we generated Snx17 knockout mice and observed that the homozygous deletion of Snx17 (Snx17-/-) resulted in lethality. On the other hand, heterozygous mutant mice (Snx17+/-) exhibited anxiety-like behavior with a reduced preference for social novelty. Furthermore, Snx17 haploinsufficiency led to impaired synaptic transmission and reduced maturation of dendritic spines. Through GST pulldown and interactome analysis, we identified the SRC kinase inhibitor, p140Cap, as a potential downstream target of SNX17. We also demonstrated that the interaction between p140Cap and SNX17 is crucial for dendritic spine maturation. Together, this study provides the first in vivo evidence highlighting the important role of SNX17 in maintaining neuronal function, as well as regulating social novelty and anxiety-like behaviors.


Assuntos
Espinhas Dendríticas , Nexinas de Classificação , Animais , Camundongos , Espinhas Dendríticas/metabolismo , Homozigoto , Transporte Proteico , Deleção de Sequência , Nexinas de Classificação/genética , Nexinas de Classificação/metabolismo
19.
Chem Biol Drug Des ; 103(1): e14405, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37989501

RESUMO

Gastric cancer currently has no effective treatment due to its high metastasis and heterogeneity. It has been reported that ropivacaine (Rop) can inhibit the growth, migration, and invasion of gastric cancer. However, the therapeutic mechanism of Rop still needs to be further explored to provide insights for its clinical application. This study aimed to explore the effects of Rop on the growth, migration, and invasion of gastric cancer cells and the underlying mechanisms. The expression levels of SNX10 were assessed in gastric cancer tissues and cell line AGS by qRT-PCR. Cell Counting Kit-8 (CCK8) assay, wound-healing assay, and transwell assay were then used to examine the effects of Rop on the AGS cell viability, migration, invasion, and proliferation, respectively. Additionally, colony formation assay was used to measure cell proliferation ability, and flow cytometry was used to detect apoptosis level. Protein levels of SNX10, SRC, and STAT3 were detected by western blot. According to the experimental results, the decreased SNX10 mRNA expression was observed in gastric cancer tissue and cell line AGS. Rop inhibited the proliferation, migration, and invasion of AGS cells, but promoted apoptosis and upregulated SNX10 expression. Moreover, Rop inhibited the expression of MMP-2 and MMP-9, phosphorylation of SRC and STAT3. SNX10 knockdown could reverse Rop-induced anticancer effects. Collectively, Rop showed a potential role in preventing proliferation and metastasis of gastric cancer. The action mechanism of Rop may be related to the upregulation of SNX10 expression and further inhibition of SRC/STAT3 signaling pathway. Our findings provide new insights into the anticancer properties of Rop.


Assuntos
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamento farmacológico , Ropivacaina/farmacologia , Ropivacaina/uso terapêutico , Movimento Celular , Transdução de Sinais , Proliferação de Células , Linhagem Celular Tumoral , Apoptose , Regulação Neoplásica da Expressão Gênica , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Nexinas de Classificação/genética , Nexinas de Classificação/metabolismo
20.
Sci Adv ; 9(35): eadh5016, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37647408

RESUMO

Intestinal stem cell (ISC) is a promising therapeutic target for inflammatory bowel disease. Cholesterol availability is critical for ISC stemness. Low plasma cholesterol is a typical feature of Crohn's disease (CD); however, its impact on mucosal healing remains unclear. Here, we identified an essential role of sorting nexin 10 (SNX10) in maintaining the stemness of ISCs. SNX10 expression in intestinal tissues positively correlates with the severity of human CD and mouse colitis. Conditional SNX10 knockout in intestinal epithelial cells or ISCs promotes intestinal mucosal repair by maintaining the ISC population associated with increased intracellular cholesterol synthesis. Disassociation of ERLIN2 with SCAP by SNX10 deletion enhances the activation of SREBP2, resulting in increased cholesterol biosynthesis. DC-SX029, a small-molecule inhibitor of SNX10, was used to verify the druggable potential of SNX10 for the treatment of patients with CD. Our study provides a strategy for mucosal healing through SREBP2-mediated stemness restoration of ISCs.


Assuntos
Doenças Inflamatórias Intestinais , Nexinas de Classificação , Animais , Humanos , Camundongos , Mucosa Intestinal , Intestinos , Nexinas de Classificação/genética , Células-Tronco
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