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International Journal of Molecular... Jun 2024In our prior investigations, we elucidated the role of the tryptophan-to-tyrosine substitution at the 61st position in the nonstructural protein NSsW61Y in diminishing...
The Effect of Tryptophan-to-Tyrosine Mutation at Position 61 of the Nonstructural Protein of Severe Fever with Thrombocytopenia Syndrome Virus on Viral Replication through Autophagosome Modulation.
In our prior investigations, we elucidated the role of the tryptophan-to-tyrosine substitution at the 61st position in the nonstructural protein NSsW61Y in diminishing the interaction between nonstructural proteins (NSs) and nucleoprotein (NP), impeding viral replication. In this study, we focused on the involvement of NSs in replication via the modulation of autophagosomes. Initially, we examined the impact of NP expression levels, a marker for replication, upon the infection of HeLa cells with severe fever thrombocytopenia syndrome virus (SFTSV), with or without the inhibition of NP binding. Western blot analysis revealed a reduction in NP levels in NSsW61Y-expressing conditions. Furthermore, the expression levels of the canonical autophagosome markers p62 and LC3 decreased in HeLa cells expressing NSsW61Y, revealing the involvement of individual viral proteins on autophagy. Subsequent experiments confirmed that NSsW61Y perturbs autophagy flux, as evidenced by reduced levels of LC3B and p62 upon treatment with chloroquine, an inhibitor of autophagosome-lysosome fusion. LysoTracker staining demonstrated a decrease in lysosomes in cells expressing the NS mutant compared to those expressing wild-type NS. We further explored the mTOR-associated regulatory pathway, a key regulator affected by NS mutant expression. The observed inhibition of replication could be linked to conformational changes in the NSs, impairing their binding to NP and altering mTOR regulation, a crucial upstream signaling component in autophagy. These findings illuminate the intricate interplay between NSsW61Y and the suppression of host autophagy machinery, which is crucial for the generation of autophagosomes to facilitate viral replication.
Topics: Humans; Viral Nonstructural Proteins; Virus Replication; Autophagosomes; HeLa Cells; Phlebovirus; Autophagy; Tyrosine; Tryptophan; TOR Serine-Threonine Kinases; Mutation; Amino Acid Substitution; Severe Fever with Thrombocytopenia Syndrome; Lysosomes; Nucleoproteins
PubMed: 38928101
DOI: 10.3390/ijms25126394 -
Genes Jun 2024Clouding of the transparent eye lens, or cataract(s), is a leading cause of visual impairment that requires surgical replacement with a synthetic intraocular lens to... (Review)
Review
Clouding of the transparent eye lens, or cataract(s), is a leading cause of visual impairment that requires surgical replacement with a synthetic intraocular lens to effectively restore clear vision. Most frequently, cataract is acquired with aging as a multifactorial or complex trait. Cataract may also be inherited as a classic Mendelian trait-often with an early or pediatric onset-with or without other ocular and/or systemic features. Since the early 1990s, over 85 genes and loci have been genetically associated with inherited and/or age-related forms of cataract. While many of these underlying genes-including those for lens crystallins, connexins, and transcription factors-recapitulate signature features of lens development and differentiation, an increasing cohort of unpredicted genes, including those involved in cell-signaling, membrane remodeling, and autophagy, has emerged-providing new insights regarding lens homeostasis and aging. This review provides a brief history of gene discovery for inherited and age-related forms of cataract compiled in the database and highlights potential gene-based therapeutic approaches to delay, reverse, or even prevent cataract formation that may help to reduce the increasing demand for cataract surgery.
Topics: Cataract; Humans; Lens, Crystalline; Animals; Crystallins; Aging
PubMed: 38927721
DOI: 10.3390/genes15060785 -
Genes May 2024Ageing has been identified as an independent risk factor for various diseases; however, the physiological basis and molecular changes related to ageing are still largely...
Ageing has been identified as an independent risk factor for various diseases; however, the physiological basis and molecular changes related to ageing are still largely unknown. Here, we show that the level of APPL2, an adaptor protein, is significantly reduced in the major organs of aged mice. Knocking down APPL2 causes premature ageing of human umbilical vein endothelial cells (HUVECs). We find that a lack of , the homologue of mammalian APPL2, leads to premature ageing, slow movements, lipid deposition, decreased resistance to stresses, and shortened lifespan in (), which are associated with decreased autophagy. Activating autophagy by rapamycin or inhibition of suppresses the age-related alternations, impaired motility, and shortened lifespan of , which are reversed by knocking down autophagy-related genes. Our work provides evidence that APPL2 and its homologue decrease with age and reveals that a lack of bridges autophagy decline and ageing in .
Topics: Animals; Caenorhabditis elegans; Longevity; Autophagy; Caenorhabditis elegans Proteins; Humans; Adaptor Proteins, Signal Transducing; Aging, Premature; Mice; Human Umbilical Vein Endothelial Cells; Aging
PubMed: 38927595
DOI: 10.3390/genes15060659 -
Biology Jun 2024The membrane glycoprotein CD133 (prominin-1) is widely regarded as the main molecular marker of cancer stem cells, which are the most malignant cell subpopulation within... (Review)
Review
The membrane glycoprotein CD133 (prominin-1) is widely regarded as the main molecular marker of cancer stem cells, which are the most malignant cell subpopulation within the tumor, responsible for tumor growth and metastasis. For this reason, CD133 is considered a promising prognostic biomarker and molecular target for antitumor therapy. Under normal conditions, CD133 is present on the cell membrane in glycosylated form. However, in malignancies, altered glycosylation apparently leads to changes in the functional activity of CD133 and the availability of some of its epitopes for antibodies. This review focuses on CD133's glycosylation in human cells and its impact on the function of this glycoprotein. The association of CD133 with proliferation, differentiation, apoptosis, autophagy, epithelial-mesenchymal transition, the organization of plasma membrane protrusions and extracellular trafficking is discussed. In this review, particular attention is paid to the influence of CD133's glycosylation on its immunodetection. A list of commercially available and custom antibodies with their characteristics is provided. The available data indicate that the development of CD133-based biomedical technologies should include an assessment of CD133's glycosylation in each tumor type.
PubMed: 38927329
DOI: 10.3390/biology13060449 -
Immunonutrition, Metabolism, and Programmed Cell Death in Lung Cancer: Translating Bench to Bedside.Biology Jun 2024Lung cancer presents significant therapeutic challenges, motivating the exploration of novel treatment strategies. Programmed cell death (PCD) mechanisms, encompassing... (Review)
Review
Lung cancer presents significant therapeutic challenges, motivating the exploration of novel treatment strategies. Programmed cell death (PCD) mechanisms, encompassing apoptosis, autophagy, and programmed necrosis, are pivotal in lung cancer pathogenesis and the treatment response. Dysregulation of these pathways contributes to tumor progression and therapy resistance. Immunonutrition, employing specific nutrients to modulate immune function, and metabolic reprogramming, a hallmark of cancer cells, offer promising avenues for intervention. Nutritional interventions, such as omega-3 fatty acids, exert modulatory effects on PCD pathways in cancer cells, while targeting metabolic pathways implicated in apoptosis regulation represents a compelling therapeutic approach. Clinical evidence supports the role of immunonutritional interventions, including omega-3 fatty acids, in augmenting PCD and enhancing treatment outcomes in patients with lung cancer. Furthermore, synthetic analogs of natural compounds, such as resveratrol, demonstrate promising anticancer properties by modulating apoptotic signaling pathways. This review underscores the convergence of immunonutrition, metabolism, and PCD pathways in lung cancer biology, emphasizing the potential for therapeutic exploration in this complex disease. Further elucidation of the specific molecular mechanisms governing these interactions is imperative for translating these findings into clinical practice and improving lung cancer management.
PubMed: 38927289
DOI: 10.3390/biology13060409 -
Biomolecules May 2024The p53 protein is the master regulator of cellular integrity, primarily due to its tumor-suppressing functions. Approximately half of all human cancers carry mutations... (Review)
Review
The p53 protein is the master regulator of cellular integrity, primarily due to its tumor-suppressing functions. Approximately half of all human cancers carry mutations in the TP53 gene, which not only abrogate the tumor-suppressive functions but also confer p53 mutant proteins with oncogenic potential. The latter is achieved through so-called gain-of-function (GOF) mutations that promote cancer progression, metastasis, and therapy resistance by deregulating transcriptional networks, signaling pathways, metabolism, immune surveillance, and cellular compositions of the microenvironment. Despite recent progress in understanding the complexity of mutp53 in neoplastic development, the exact mechanisms of how mutp53 contributes to cancer development and how they escape proteasomal and lysosomal degradation remain only partially understood. In this review, we address recent findings in the field of oncogenic functions of mutp53 specifically regarding, but not limited to, its implications in metabolic pathways, the secretome of cancer cells, the cancer microenvironment, and the regulating scenarios of the aberrant proteasomal degradation. By analyzing proteasomal and lysosomal protein degradation, as well as its connection with autophagy, we propose new therapeutical approaches that aim to destabilize mutp53 proteins and deactivate its oncogenic functions, thereby providing a fundamental basis for further investigation and rational treatment approaches for TP53-mutated cancers.
Topics: Humans; Tumor Suppressor Protein p53; Neoplasms; Tumor Microenvironment; Proteolysis; Proteasome Endopeptidase Complex; Autophagy; Animals; Mutation; Lysosomes; Carcinogenesis
PubMed: 38927053
DOI: 10.3390/biom14060649 -
The Korean Journal of Physiology &... Jul 2024Breast cancer (BC) is most commonly diagnosed worldwide. Liquiritigenin is a flavonoid found in various species of the Glycyrrhiza genus, showing anti-tumor activity....
Breast cancer (BC) is most commonly diagnosed worldwide. Liquiritigenin is a flavonoid found in various species of the Glycyrrhiza genus, showing anti-tumor activity. This article was to explore the influences of liquiritigenin on the biological behaviors of BC cells and its underlying mechanism. BC cells were treated with liquiritigenin alone or transfected with oe-HSP90 before liquiritigenin treatment. RT-qPCR and Western blotting were employed to examine the levels of HSP90, Snail, E-cadherin, HSC70, and LAMP-2A. Cell viability, proliferation, migration, and invasion were evaluated by performing MTT, colony formation, scratch, and Transwell assays, respectively. Liquiritigenin treatment reduced HSP90 and Snail levels and enhanced E-cadherin expression as well as inhibiting the proliferation, migration, and invasion of BC cells. Moreover, liquiritigenin treatment decreased the expression of HSC70 and LAMP-2A, proteins related to chaperone-mediated autophagy (CMA). HSP90 overexpression promoted the CMA, invasion, and migration of BC cells under liquiritigenin treatment. Liquiritigenin inhibits HSP90-mediated CMA, thereby suppressing BC cell growth.
PubMed: 38926844
DOI: 10.4196/kjpp.2024.28.4.379 -
Journal of Experimental & Clinical... Jun 2024Paclitaxel (PTX) treatment resistance is an important factor leading to poor prognosis in triple-negative breast cancer (TNBC), therefore there is an urgent need to...
BACKGROUND
Paclitaxel (PTX) treatment resistance is an important factor leading to poor prognosis in triple-negative breast cancer (TNBC), therefore there is an urgent need to identify new target for combination therapy. Neddylation is a post-translational process that introduces a ubiquitin-like protein called neural precursor cell expressed developmentally downregulated protein 8 (NEDD8). Previous studies have found that neddylation is activated in multiple tumors, but its relationship with PTX chemotherapy sensitivity has not been reported.
METHODS
Differences in UBC12 and NEDD8 expression levels between PTX-sensitive and PTX-insensitive TNBC tissues were validated using public databases and immunohistochemistry. The in vitro and in vivo functional experiments were used to observe the effect of neddylation inhibition combined with PTX therapy on tumor progression. Co-IP, western blot and PCR assays were used to investigate the molecular mechanisms. Molecular docking was used to simulate the protein binding of UBC12 and TRIM25. Molecular dynamics simulation was used to observe the changes in TRIM25 protein conformation.
RESULTS
We found that in TNBC that is insensitive to PTX, NEDD8 and NEDD8 conjugating enzyme UBC12 are highly expressed. Treatment with the NEDD8-activating enzyme (NAE) inhibitor mln4924 or knockdown of UBC12 significantly increased the sensitivity of the tumor to PTX, and this increase in sensitivity is related to UBC12-mediated autophagy activation. Mechanistically, UBC12 can transfer NEDD8 to E3 ubiquitin ligase tripartite motif containing 25 (TRIM25) at K117. Molecular dynamics simulations indicate that the neddylation modification of TRIM25 reduces steric hindrance in its RING domain, facilitating the binding of TRIM25 and ubiquitylated substrates. Subsequently, TRIM25 promotes the nuclear translocation of transcription factor EB (TFEB) and transcription of autophagy related genes by increasing K63-polyubiquitination of TFEB, thereby reducing tumor sensitivity to PTX.
CONCLUSIONS
Neddylation is activated in PTX-insensitive TNBC. Specifically, autophagy gene transcriptional activation mediated by the UBC12/TRIM25/TFEB axis reduces TNBC sensitivity to PTX. Neddylation suppression combination with PTX treatment shows a synergistic anti-tumor effect.
Topics: Humans; Triple Negative Breast Neoplasms; Paclitaxel; Female; Mice; Animals; Autophagy; NEDD8 Protein; Ubiquitin-Protein Ligases; Tripartite Motif Proteins; Cell Line, Tumor; Transcription Factors; Cyclopentanes; Drug Resistance, Neoplasm; Xenograft Model Antitumor Assays; Ubiquitin-Conjugating Enzymes
PubMed: 38926803
DOI: 10.1186/s13046-024-03085-w -
Scientific Reports Jun 2024We examined the role of protein tyrosine phosphatase receptor sigma (PTPRS) in the context of Alzheimer's disease and synaptic integrity. Publicly available datasets...
We examined the role of protein tyrosine phosphatase receptor sigma (PTPRS) in the context of Alzheimer's disease and synaptic integrity. Publicly available datasets (BRAINEAC, ROSMAP, ADC1) and a cohort of asymptomatic but "at risk" individuals (PREVENT-AD) were used to explore the relationship between PTPRS and various Alzheimer's disease biomarkers. We identified that PTPRS rs10415488 variant C shows features of neuroprotection against early Tau pathology and synaptic degeneration in Alzheimer's disease. This single nucleotide polymorphism correlated with higher PTPRS transcript abundance and lower p(181)Tau and GAP-43 levels in the CSF. In the brain, PTPRS protein abundance was significantly correlated with the quantity of two markers of synaptic integrity: SNAP25 and SYT-1. We also found the presence of sexual dimorphism for PTPRS, with higher CSF concentrations in males than females. Male carriers for variant C were found to have a 10-month delay in the onset of AD. We thus conclude that PTPRS acts as a neuroprotective receptor in Alzheimer's disease. Its protective effect is most important in males, in whom it postpones the age of onset of the disease.
Topics: Alzheimer Disease; Humans; Male; Female; tau Proteins; Biomarkers; Polymorphism, Single Nucleotide; Aged; Synapses; Synaptosomal-Associated Protein 25; Receptor-Like Protein Tyrosine Phosphatases, Class 2; Aged, 80 and over; Synaptotagmin I; Brain; Middle Aged
PubMed: 38926456
DOI: 10.1038/s41598-024-65104-2 -
Zhongguo Dang Dai Er Ke Za Zhi =... Jun 2024To observe the effects of melatonin on autophagy in cortical neurons of neonatal rats with hypoxic-ischemic brain damage (HIBD) and to explore its mechanisms via the...
OBJECTIVES
To observe the effects of melatonin on autophagy in cortical neurons of neonatal rats with hypoxic-ischemic brain damage (HIBD) and to explore its mechanisms via the PI3K/AKT signaling pathway, aiming to provide a basis for the clinical application of melatonin.
METHODS
Seven-day-old Sprague-Dawley neonatal rats were randomly divided into a sham operation group, an HIBD group, and a melatonin group (=9 each). The neonatal rat HIBD model was established using the classic Rice-Vannucci method. Neuronal morphology in the neonatal rat cerebral cortex was observed with hematoxylin-eosin staining and Nissl staining. Autophagy-related protein levels of microtubule-associated protein 1 light chain 3 (LC3) and Beclin-1 were detected by immunofluorescence staining and Western blot analysis. Phosphorylated phosphoinositide 3-kinase (p-PI3K) and phosphorylated protein kinase B (p-AKT) protein expression levels were measured by immunohistochemistry and Western blot. The correlation between autophagy and the PI3K pathway in the melatonin group and the HIBD group was analyzed using Pearson correlation analysis.
RESULTS
Twenty-four hours post-modeling, neurons in the sham operation group displayed normal size and orderly arrangement. In contrast, neurons in the HIBD group showed swelling and disorderly arrangement, while those in the melatonin group had relatively normal morphology and more orderly arrangement. Nissl bodies were normal in the sham operation group but distorted in the HIBD group; however, they remained relatively intact in the melatonin group. The average fluorescence intensity of LC3 and Beclin-1 was higher in the HIBD group compared to the sham operation group, but was reduced in the melatonin group compared to the HIBD group (<0.05). The number of p-PI3K and p-AKT cells decreased in the HIBD group compared to the sham operation group but increased in the melatonin group compared to the HIBD group (<0.05). LC3 and Beclin-1 protein expression levels were higher, and p-PI3K and p-AKT levels were lower in the HIBD group compared to the sham operation group (<0.05); however, in the melatonin group, LC3 and Beclin-1 levels decreased, and p-PI3K and p-AKT increased compared to the HIBD group (<0.05). The correlation analysis results showed that the difference of the mean fluorescence intensity of LC3 and Beclin-1 protein in the injured cerebral cortex between the melatonin and HIBD groups was negatively correlated with the difference of the number of p-PI3K and p-AKT cells between the two groups (<0.05).
CONCLUSIONS
Melatonin can inhibit excessive autophagy in cortical neurons of neonatal rats with HIBD, thereby alleviating HIBD. This mechanism is associated with the PI3K/AKT pathway.
Topics: Animals; Melatonin; Hypoxia-Ischemia, Brain; Rats, Sprague-Dawley; Rats; Proto-Oncogene Proteins c-akt; Animals, Newborn; Cerebral Cortex; Autophagy; Phosphatidylinositol 3-Kinases; Neurons; Signal Transduction; Male; Female
PubMed: 38926381
DOI: 10.7499/j.issn.1008-8830.2312053