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1.
Mol Cell ; 82(10): 1894-1908.e5, 2022 05 19.
Article in English | MEDLINE | ID: mdl-35390275

ABSTRACT

miR-10b is silenced in normal neuroglial cells of the brain but commonly activated in glioma, where it assumes an essential tumor-promoting role. We demonstrate that the entire miR-10b-hosting HOXD locus is activated in glioma via the cis-acting mechanism involving 3D chromatin reorganization and CTCF-cohesin-mediated looping. This mechanism requires two interacting lncRNAs, HOXD-AS2 and LINC01116, one associated with HOXD3/HOXD4/miR-10b promoter and another with the remote enhancer. Knockdown of either lncRNA in glioma cells alters CTCF and cohesin binding, abolishes chromatin looping, inhibits the expression of all genes within HOXD locus, and leads to glioma cell death. Conversely, in cortical astrocytes, enhancer activation is sufficient for HOXD/miR-10b locus reorganization, gene derepression, and neoplastic cell transformation. LINC01116 RNA is essential for this process. Our results demonstrate the interplay of two lncRNAs in the chromatin folding and concordant regulation of miR-10b and multiple HOXD genes normally silenced in astrocytes and triggering the neoplastic glial transformation.


Subject(s)
Glioma , MicroRNAs , RNA, Long Noncoding , Cell Line, Tumor , Cell Proliferation/genetics , Cell Transformation, Neoplastic/genetics , Chromatin/genetics , Gene Expression Regulation, Neoplastic , Glioma/genetics , Glioma/metabolism , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism
2.
Proc Natl Acad Sci U S A ; 121(22): e2400648121, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38781210

ABSTRACT

After central nervous system injury, a rapid cellular and molecular response is induced. This response can be both beneficial and detrimental to neuronal survival in the first few days and increases the risk for neurodegeneration if persistent. Semaphorin4B (Sema4B), a transmembrane protein primarily expressed by cortical astrocytes, has been shown to play a role in neuronal cell death following injury. Our study shows that after cortical stab wound injury, cytokine expression is attenuated in Sema4B-/- mice, and microglia/macrophage reactivity is altered. In vitro, Sema4B enhances the reactivity of microglia following injury, suggesting astrocytic Sema4B functions as a ligand. Moreover, injury-induced microglia reactivity is attenuated in the presence of Sema4B-/- astrocytes compared to Sema4B+/- astrocytes. In vitro experiments indicate that Plexin-B2 is the Sema4B receptor on microglia. Consistent with this, in microglia/macrophage-specific Plexin-B2-/- mice, similar to Sema4B-/- mice, microglial/macrophage reactivity and neuronal cell death are attenuated after cortical injury. Finally, in Sema4B/Plexin-B2 double heterozygous mice, microglial/macrophage reactivity is also reduced after injury, supporting the idea that both Sema4B and Plexin-B2 are part of the same signaling pathway. Taken together, we propose a model in which following injury, astrocytic Sema4B enhances the response of microglia/macrophages via Plexin-B2, leading to increased reactivity.


Subject(s)
Astrocytes , Mice, Knockout , Microglia , Nerve Tissue Proteins , Semaphorins , Animals , Mice , Astrocytes/metabolism , Brain Injuries/metabolism , Brain Injuries/pathology , Brain Injuries/genetics , Cell Communication , Macrophages/metabolism , Mice, Inbred C57BL , Microglia/metabolism , Microglia/pathology , Nerve Tissue Proteins/metabolism , Nerve Tissue Proteins/genetics , Semaphorins/metabolism , Semaphorins/genetics
3.
Immunity ; 47(3): 566-581.e9, 2017 09 19.
Article in English | MEDLINE | ID: mdl-28930663

ABSTRACT

Microglia play a pivotal role in the maintenance of brain homeostasis but lose homeostatic function during neurodegenerative disorders. We identified a specific apolipoprotein E (APOE)-dependent molecular signature in microglia from models of amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and Alzheimer's disease (AD) and in microglia surrounding neuritic ß-amyloid (Aß)-plaques in the brains of people with AD. The APOE pathway mediated a switch from a homeostatic to a neurodegenerative microglia phenotype after phagocytosis of apoptotic neurons. TREM2 (triggering receptor expressed on myeloid cells 2) induced APOE signaling, and targeting the TREM2-APOE pathway restored the homeostatic signature of microglia in ALS and AD mouse models and prevented neuronal loss in an acute model of neurodegeneration. APOE-mediated neurodegenerative microglia had lost their tolerogenic function. Our work identifies the TREM2-APOE pathway as a major regulator of microglial functional phenotype in neurodegenerative diseases and serves as a novel target that could aid in the restoration of homeostatic microglia.


Subject(s)
Apolipoproteins E/metabolism , Membrane Glycoproteins/metabolism , Microglia/metabolism , Neurodegenerative Diseases/genetics , Neurodegenerative Diseases/metabolism , Receptors, Immunologic/metabolism , Signal Transduction , Transcriptome , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/metabolism , Animals , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Apoptosis/genetics , Apoptosis/immunology , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Cluster Analysis , Disease Models, Animal , Encephalomyelitis, Autoimmune, Experimental , Female , Gene Expression Profiling , Gene Expression Regulation , Gene Targeting , Humans , Immune Tolerance , Mice , Mice, Knockout , Mice, Transgenic , Microglia/immunology , Monocytes/immunology , Monocytes/metabolism , Neurodegenerative Diseases/immunology , Neurons/metabolism , Phagocytosis/genetics , Phagocytosis/immunology , Phenotype , Plaque, Amyloid/metabolism , Plaque, Amyloid/pathology , Superoxide Dismutase-1/genetics , Superoxide Dismutase-1/metabolism , Transforming Growth Factor beta/metabolism
4.
Neurobiol Dis ; 178: 106011, 2023 03.
Article in English | MEDLINE | ID: mdl-36702317

ABSTRACT

Metabolic reactions within cells occur in various isolated compartments with or without borders, the latter being known as membrane-less organelles (MLOs). The MLOs show liquid-like properties and are formed by a process known as liquid-liquid phase separation (LLPS). MLOs contribute to different molecules interactions such as protein-protein, protein-RNA, and RNA-RNA driven by various factors, such as multivalency of intrinsic disorders. MLOs are involved in several cell signaling pathways such as transcription, immune response, and cellular organization. However, disruption of these processes has been found in different pathologies. Recently, it has been demonstrated that protein aggregates, a characteristic of some neurodegenerative diseases, undergo similar phase separation. Tau protein is known as a major neurofibrillary tangles component in Alzheimer's disease (AD). This protein can undergo phase separation to form a MLO known as tau droplet in vitro and in vivo, and this process can be facilitated by several factors, including crowding agents, RNA, and phosphorylation. Tau droplet has been shown to mature into insoluble aggregates suggesting that this process may precede and induce neurodegeneration in AD. Here we review major factors involved in liquid droplet formation within a cell. Additionally, we highlight recent findings concerning tau aggregation following phase separation in AD, along with the potential therapeutic strategies that could be explored in this process against the progression of this pathology.


Subject(s)
Alzheimer Disease , Humans , Alzheimer Disease/metabolism , tau Proteins/metabolism , Neurofibrillary Tangles/metabolism , RNA/metabolism
5.
Mol Cancer ; 21(1): 17, 2022 01 15.
Article in English | MEDLINE | ID: mdl-35033060

ABSTRACT

BACKGROUND: miRNAs are regulatory transcripts established as repressors of mRNA stability and translation that have been functionally implicated in carcinogenesis. miR-10b is one of the key onco-miRs associated with multiple forms of cancer. Malignant gliomas exhibit particularly striking dependence on miR-10b. However, despite the therapeutic potential of miR-10b targeting, this miRNA's poorly investigated and largely unconventional properties hamper the clinical translation. METHODS: We utilized Covalent Ligation of Endogenous Argonaute-bound RNAs and their high-throughput RNA sequencing to identify miR-10b interactome and a combination of biochemical and imaging approaches for target validation. They included Crosslinking and RNA immunoprecipitation with spliceosomal proteins, a combination of miRNA FISH with protein immunofluorescence in glioma cells and patient-derived tumors, native Northern blotting, and the transcriptome-wide analysis of alternative splicing. RESULTS: We demonstrate that miR-10b binds to U6 snRNA, a core component of the spliceosomal machinery. We provide evidence of the direct binding between miR-10b and U6, in situ imaging of miR-10b and U6 co-localization in glioma cells and tumors, and biochemical co-isolation of miR-10b with the components of the spliceosome. We further demonstrate that miR-10b modulates U6 N-6-adenosine methylation and pseudouridylation, U6 binding to splicing factors SART3 and PRPF8, and regulates U6 stability, conformation, and levels. These effects on U6 result in global splicing alterations, exemplified by the altered ratio of the isoforms of a small GTPase CDC42, reduced overall CDC42 levels, and downstream CDC42 -mediated effects on cell viability. CONCLUSIONS: We identified U6 snRNA, the key RNA component of the spliceosome, as the top miR-10b target in glioblastoma. We, therefore, present an unexpected intersection of the miRNA and splicing machineries and a new nuclear function for a major cancer-associated miRNA.


Subject(s)
Cell Nucleus/genetics , Gene Expression Regulation, Neoplastic , MicroRNAs/genetics , Oncogenes , RNA Splicing , RNA, Small Nuclear/genetics , Alternative Splicing , Antigens, Neoplasm/metabolism , Cell Line, Tumor , Humans , Membrane Glycoproteins/genetics , Models, Biological , RNA Interference , RNA, Small Nuclear/chemistry , RNA-Binding Proteins/metabolism , Receptors, Immunologic/genetics , Spliceosomes/metabolism , cdc42 GTP-Binding Protein/genetics
6.
Neurobiol Dis ; 134: 104617, 2020 02.
Article in English | MEDLINE | ID: mdl-31669733

ABSTRACT

As the most common cause of progressive cognitive decline in humans, Alzheimer's disease (AD) has been intensively studied, but the mechanisms underlying its profound synaptic dysfunction remain unclear. Here we confirm that exposing wild-type mice to an enriched environment (EE) facilitates signaling in the hippocampus that promotes long-term potentiation (LTP). Exposing the hippocampus of mice kept in standard housing to soluble Aß oligomers impairs LTP, but EE can fully prevent this. Mechanistically, the key molecular features of the EE benefit are an upregulation of miRNA-132 and an inhibition of histone deacetylase (HDAC) signaling. Specifically, soluble Aß oligomers decreased miR-132 expression and increased HDAC3 levels in cultured primary neurons. Further, we provide evidence that HDAC3 is a direct target of miR-132. Overexpressing miR-132 or injecting an HDAC3 inhibitor into mice in standard housing mimics the benefits of EE in enhancing hippocampal LTP and preventing hippocampal impairment by Aß oligomers in vivo. We conclude that EE enhances hippocampal synaptic plasticity by upregulating miRNA-132 and reducing HDAC3 signaling in a way that counteracts the synaptotoxicity of human Aß oligomers. Our findings provide a rationale for prolonged exposure to cognitive novelty and/or epigenetic modulation to lessen the progressive effects of Aß accumulation during human brain aging.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides/toxicity , Histone Deacetylases/metabolism , Housing, Animal , Long-Term Potentiation/physiology , MicroRNAs/metabolism , Animals , Female , Gene Expression Regulation/physiology , Hippocampus/drug effects , Hippocampus/metabolism , Humans , Male , Mice , Signal Transduction/physiology
7.
PLoS Genet ; 12(7): e1006192, 2016 07.
Article in English | MEDLINE | ID: mdl-27462983

ABSTRACT

Local translation at the synapse plays key roles in neuron development and activity-dependent synaptic plasticity. mRNAs are translocated from the neuronal soma to the distant synapses as compacted ribonucleoparticles referred to as RNA granules. These contain many RNA-binding proteins, including the Fragile X Mental Retardation Protein (FMRP), the absence of which results in Fragile X Syndrome, the most common inherited form of intellectual disability and the leading genetic cause of autism. Using FMRP as a tracer, we purified a specific population of RNA granules from mouse brain homogenates. Protein composition analyses revealed a strong relationship between polyribosomes and RNA granules. However, the latter have distinct architectural and structural properties, since they are detected as close compact structures as observed by electron microscopy, and converging evidence point to the possibility that these structures emerge from stalled polyribosomes. Time-lapse video microscopy indicated that single granules merge to form cargoes that are transported from the soma to distal locations. Transcriptomic analyses showed that a subset of mRNAs involved in cytoskeleton remodelling and neural development is selectively enriched in RNA granules. One third of the putative mRNA targets described for FMRP appear to be transported in granules and FMRP is more abundant in granules than in polyribosomes. This observation supports a primary role for FMRP in granules biology. Our findings open new avenues for the study of RNA granule dysfunctions in animal models of nervous system disorders, such as Fragile X syndrome.


Subject(s)
Fragile X Mental Retardation Protein/genetics , Fragile X Syndrome/genetics , RNA-Binding Proteins/genetics , Synapses/genetics , Animals , Brain/growth & development , Brain/metabolism , Fragile X Mental Retardation Protein/metabolism , Fragile X Syndrome/pathology , Gene Expression Regulation, Developmental , Humans , Mice , Neuronal Plasticity/genetics , Neurons/metabolism , Polyribosomes/genetics , Protein Biosynthesis/genetics , RNA, Messenger/genetics , RNA-Binding Proteins/biosynthesis , Synapses/metabolism
8.
J Allergy Clin Immunol ; 142(6): 1894-1908.e7, 2018 12.
Article in English | MEDLINE | ID: mdl-29470999

ABSTRACT

BACKGROUND: Given their unique capacity for antigen uptake, processing, and presentation, antigen-presenting cells (APCs) are critical for initiating and regulating innate and adaptive immune responses. We have previously shown the role of nicotinamide adenine dinucleotide (NAD+) in T-cell differentiation independently of the cytokine milieu, whereas the precise mechanisms remained unknown. OBJECTIVE: The objective of this study is to further dissect the mechanism of actions of NAD+ and determine the effect of APCs on NAD+-mediated T-cell activation. METHODS: Isolated dendritic cells and bone marrow-derived mast cells (MCs) were used to characterize the mechanisms of action of NAD+ on CD4+ T-cell fate in vitro. Furthermore, NAD+-mediated CD4+ T-cell differentiation was investigated in vivo by using wild-type C57BL/6, MC-/-, MHC class II-/-, Wiskott-Aldrich syndrome protein (WASP)-/-, 5C.C7 recombination-activating gene 2 (Rag2)-/-, and CD11b-DTR transgenic mice. Finally, we tested the physiologic effect of NAD+ on the systemic immune response in the context of Listeria monocytogenes infection. RESULTS: Our in vivo and in vitro findings indicate that after NAD+ administration, MCs exclusively promote CD4+ T-cell differentiation, both in the absence of antigen and independently of major APCs. Moreover, we found that MCs mediated CD4+ T-cell differentiation independently of MHC II and T-cell receptor signaling machinery. More importantly, although treatment with NAD+ resulted in decreased MHC II expression on CD11c+ cells, MC-mediated CD4+ T-cell differentiation rendered mice resistant to administration of lethal doses of L monocytogenes. CONCLUSIONS: Collectively, our study unravels a novel cellular and molecular pathway that regulates innate and adaptive immunity through MCs exclusively and underscores the therapeutic potential of NAD+ in the context of primary immunodeficiencies and antimicrobial resistance.


Subject(s)
CD4-Positive T-Lymphocytes/drug effects , Mast Cells/drug effects , NAD/pharmacology , Adult , Animals , Antigen Presentation , CD4-Positive T-Lymphocytes/immunology , Cell Differentiation/drug effects , Cell Line , Humans , Listeria monocytogenes , Listeriosis/drug therapy , Listeriosis/immunology , Mast Cells/immunology , Mice, Inbred C57BL , Mice, Transgenic , NAD/therapeutic use
9.
Acta Neuropathol ; 136(4): 537-555, 2018 10.
Article in English | MEDLINE | ID: mdl-29982852

ABSTRACT

MicroRNAs (miRNA) regulate fundamental biological processes, including neuronal plasticity, stress response, and survival. Here, we describe a neuroprotective function of miR-132, the miRNA most significantly downregulated in neurons in Alzheimer's disease. We demonstrate that miR-132 protects primary mouse and human wild-type neurons and more vulnerable Tau-mutant neurons against amyloid ß-peptide (Aß) and glutamate excitotoxicity. It lowers the levels of total, phosphorylated, acetylated, and cleaved forms of Tau implicated in tauopathies, promotes neurite elongation and branching, and reduces neuronal death. Similarly, miR-132 attenuates PHF-Tau pathology and neurodegeneration, and enhances long-term potentiation in the P301S Tau transgenic mice. The neuroprotective effects are mediated by direct regulation of the Tau modifiers acetyltransferase EP300, kinase GSK3ß, RNA-binding protein Rbfox1, and proteases Calpain 2 and Caspases 3/7. These data suggest miR-132 as a master regulator of neuronal health and indicate that miR-132 supplementation could be of therapeutic benefit for the treatment of Tau-associated neurodegenerative disorders.


Subject(s)
MicroRNAs/genetics , Signal Transduction/genetics , Tauopathies/genetics , Amyloid beta-Peptides/genetics , Animals , Cell Death , Glutamic Acid/toxicity , Humans , Mice , Mice, Transgenic , MicroRNAs/physiology , Mutation/genetics , Nerve Degeneration/genetics , Nerve Degeneration/pathology , Neurites/pathology , Neurons/pathology , Primary Cell Culture , Protein Processing, Post-Translational , RNA, Long Noncoding/genetics , tau Proteins/genetics
10.
Mol Ther ; 25(2): 368-378, 2017 02 01.
Article in English | MEDLINE | ID: mdl-28153089

ABSTRACT

Glioblastoma (GBM) brain tumor remains among the most lethal and incurable human diseases. Oncogenic microRNA-10b (miR-10b) is strongly and universally upregulated in GBM, and its inhibition by antisense oligonucleotides (ASOs) reduces the growth of heterogeneous glioma cells; therefore, miR-10b represents a unique therapeutic target for GBM. Here we explored the effects of miR-10b gene editing on GBM. Using the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system, we investigated effects of miR-10b gene editing on the growth of cultured human glioma cells, tumor-initiating stem-like cells, and mouse GBM xenografts, as well as the oncogene-induced transformation of normal astrocytes. We show that GBM is strictly "addicted" to miR-10b and that miR-10b gene ablation is lethal for glioma cell cultures and established intracranial tumors. miR-10b loss-of-function mutations lead to the death of glioma, but not other cancer cell lines. We have not detected escaped proliferative clones of GBM cells edited in the miR-10b locus. Finally, neoplastic transformation of normal astrocytes was abolished by the miR-10b-editing vectors. This study demonstrates the feasibility of gene editing for brain tumors in vivo and suggests virus-mediated miR-10b gene ablation as a promising therapeutic approach that permanently eliminates the key regulator essential for tumor growth and survival.


Subject(s)
Brain Neoplasms/genetics , Gene Editing , Glioblastoma/genetics , MicroRNAs/genetics , Animals , Astrocytes/metabolism , Astrocytes/pathology , Base Sequence , Brain Neoplasms/pathology , CRISPR-Cas Systems , Cell Line, Tumor , Cell Proliferation , Cell Survival/genetics , Cell Transformation, Neoplastic/genetics , Disease Models, Animal , Gene Expression Regulation, Neoplastic , Glioblastoma/pathology , Humans , Mice , Mutation , RNA, Guide, Kinetoplastida/chemistry , RNA, Guide, Kinetoplastida/genetics
11.
PLoS Genet ; 9(10): e1003890, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24204304

ABSTRACT

Fragile X syndrome is caused by loss of function of a single gene encoding the Fragile X Mental Retardation Protein (FMRP). This RNA-binding protein, widely expressed in mammalian tissues, is particularly abundant in neurons and is a component of messenger ribonucleoprotein (mRNP) complexes present within the translational apparatus. The absence of FMRP in neurons is believed to cause translation dysregulation and defects in mRNA transport essential for local protein synthesis and for synaptic development and maturation. A prevalent model posits that FMRP is a nucleocytoplasmic shuttling protein that transports its mRNA targets from the nucleus to the translation machinery. However, it is not known which of the multiple FMRP isoforms, resulting from the numerous alternatively spliced FMR1 transcripts variants, would be involved in such a process. Using a new generation of anti-FMRP antibodies and recombinant expression, we show here that the most commonly expressed human FMRP isoforms (ISO1 and 7) do not localize to the nucleus. Instead, specific FMRP isoforms 6 and 12 (ISO6 and 12), containing a novel C-terminal domain, were the only isoforms that localized to the nuclei in cultured human cells. These isoforms localized to specific p80-coilin and SMN positive structures that were identified as Cajal bodies. The Cajal body localization signal was confined to a 17 amino acid stretch in the C-terminus of human ISO6 and is lacking in a mouse Iso6 variant. As FMRP is an RNA-binding protein, its presence in Cajal bodies suggests additional functions in nuclear post-transcriptional RNA metabolism. Supporting this hypothesis, a missense mutation (I304N), known to alter the KH2-mediated RNA binding properties of FMRP, abolishes the localization of human FMRP ISO6 to Cajal bodies. These findings open unexplored avenues in search for new insights into the pathophysiology of Fragile X Syndrome.


Subject(s)
Coiled Bodies/genetics , Fragile X Mental Retardation Protein/genetics , Fragile X Syndrome/genetics , Protein Isoforms/biosynthesis , Animals , Cell Nucleus/genetics , Cell Nucleus/ultrastructure , Coiled Bodies/ultrastructure , Fragile X Mental Retardation Protein/biosynthesis , Fragile X Syndrome/pathology , Gene Expression Regulation , Humans , Mice , Neurons/metabolism , Protein Isoforms/ultrastructure , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , RNA-Binding Proteins/genetics , Ribonucleoproteins/genetics
12.
Hum Mol Genet ; 22(4): 668-84, 2013 Feb 15.
Article in English | MEDLINE | ID: mdl-23136128

ABSTRACT

SMN1, the causative gene for spinal muscular atrophy (SMA), plays a housekeeping role in the biogenesis of small nuclear RNA ribonucleoproteins. SMN is also present in granular foci along axonal projections of motoneurons, which are the predominant cell type affected in the pathology. These so-called RNA granules mediate the transport of specific mRNAs along neurites and regulate mRNA localization, stability, as well as local translation. Recent work has provided evidence suggesting that SMN may participate in the assembly of RNA granules, but beyond that, the precise nature of its role within these structures remains unclear. Here, we demonstrate that SMN associates with polyribosomes and can repress translation in an in vitro translation system. We further identify the arginine methyltransferase CARM1 as an mRNA that is regulated at the translational level by SMN and find that CARM1 is abnormally up-regulated in spinal cord tissue from SMA mice and in severe type I SMA patient cells. We have previously characterized a novel regulatory pathway in motoneurons involving the SMN-interacting RNA-binding protein HuD and CARM1. Thus, our results suggest the existence of a potential negative feedback loop in this pathway. Importantly, an SMA-causing mutation in the Tudor domain of SMN completely abolished translational repression, a strong indication for the functional significance of this novel SMN activity in the pathology.


Subject(s)
Gene Expression Regulation, Enzymologic , Protein Biosynthesis , Survival of Motor Neuron 1 Protein/genetics , Animals , Cells, Cultured , Genes, Reporter , Humans , Luciferases, Renilla/biosynthesis , Luciferases, Renilla/genetics , Mice , Mice, Transgenic , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/metabolism , Polyribosomes/metabolism , Protein Structure, Tertiary , Protein-Arginine N-Methyltransferases/genetics , Protein-Arginine N-Methyltransferases/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Ribonucleoproteins/metabolism , Spinal Cord/enzymology , Survival of Motor Neuron 1 Protein/metabolism , Survival of Motor Neuron 1 Protein/physiology , Untranslated Regions , Up-Regulation
13.
Heliyon ; 10(18): e37321, 2024 Sep 30.
Article in English | MEDLINE | ID: mdl-39323826

ABSTRACT

Snake venom is a cocktail and rich source of various bioactive compounds that have been extensively studied for their potential as pharmaceutical agents due to their diverse chemical structures and wide range of biological activities. In light of the emergency and the re-emergence of viral infectious diseases that threaten human health and economic systems, exploring new fertile and rich fields such as snake venom is an attractive path for anti-viral drug discovery, especially in the lack of effective vaccines. Although 85 % of reported antiviral molecules belong to the phospholipase A2 (PLA2) family, other protein families including L-amino acid oxidases (LAAO), disintegrins, metalloproteases (SVMPs), and cathelicidins have also shown antiviral activity. Thus, in this review, we have highlighted the antiviral properties of compounds derived from snake venom and their mechanisms of action against virus classes like HIV, Coronaviridae, Flaviviridae, and Paramyxoviridae. Although the initial research emphasis has been on Retroviridae (HIV) and Flaviviridae viruses, it is crucial to extend the exploration of the potential of these compounds to other viruses. The utilization of snake venom-derived compounds as antivirals shows significant promise for the development of novel therapeutics to address viral infections. However, a more in-depth investigation is necessary to fully assess the potential of these compounds against other viruses and unveil the mechanisms underlying their action.

14.
Int J Pharm ; 660: 124331, 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-38866083

ABSTRACT

The present work reports the adsorption, release, antibacterial properties, and in vitro cytotoxicity of sodium fusidate (SF) associated with a carbonated calcium phosphate bone cement. The adsorption study of SF on cement powder compared to stoichiometric hydroxyapatite and nanocrystalline carbonated apatite was investigated to understand the interaction between this antibiotic and the calcium phosphate phases involved in the cement formulation and setting reaction. The adsorption data revealed a fast kinetic process. However, the evolution of the amount of adsorbed SF was well described by a Freundlich-type isotherm characterized by a low adsorption capacity of the materials toward the SF molecule. The in vitro release results indicated a prolonged and controlled SF release for up to 34 days. The SF amounts eluted daily were at a therapeutic level (0.5-2 mg/L) and close to the antibiotic minimum inhibitory concentration (0.1-0.9 mg/L). Furthermore, the release data fitting and modeling suggested that the drug release occurred mainly by a diffusion mechanism. The antibacterial activity showed the effectiveness of SF released from the formulated cements against Staphylococcus aureus. Furthermore, the biological in vitro study demonstrated that the tested cements didn't show any cytotoxicity towards human peripheral blood mononuclear cells and did not significantly induce inflammation markers like IL-8.


Subject(s)
Anti-Bacterial Agents , Bone Cements , Calcium Phosphates , Drug Liberation , Fusidic Acid , Staphylococcus aureus , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/toxicity , Humans , Staphylococcus aureus/drug effects , Calcium Phosphates/chemistry , Bone Cements/chemistry , Bone Cements/pharmacology , Adsorption , Fusidic Acid/pharmacology , Fusidic Acid/chemistry , Fusidic Acid/administration & dosage , Cell Survival/drug effects , Microbial Sensitivity Tests , Leukocytes, Mononuclear/drug effects , Kinetics
15.
Genes Dis ; 11(6): 101174, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39224109

ABSTRACT

Sodium-glucose co-transporter inhibitors (SGLTis) are the latest class of anti-hyperglycemic agents. In addition to inhibiting the absorption of glucose by the kidney causing glycosuria, these drugs also demonstrate cardio-renal benefits in diabetic subjects. miR-30 family, one of the most abundant microRNAs in the heart, has recently been linked to a setting of cardiovascular diseases and has been proposed as novel biomarkers in kidney dysfunctions as well; their expression is consistently dysregulated in a variety of cardio-renal dysfunctions. The mechanistic involvement and the potential interplay between miR-30 and SGLT2i effects have yet to be thoroughly elucidated. Recent research has stressed the relevance of this cluster of microRNAs as modulators of several pathological processes in the heart and kidneys, raising the possibility of these small ncRNAs playing a central role in various cardiovascular complications, notably, endothelial dysfunction and pathological remodeling. Here, we review current evidence supporting the pleiotropic effects of SGLT2is in cardiovascular and renal outcomes and investigate the link and the coordinated implication of the miR-30 family in endothelial dysfunction and cardiac remodeling. We also discuss the emerging role of circulating miR-30 as non-invasive biomarkers and attractive therapeutic targets for cardiovascular diseases and kidney diseases. Clinical evidence, as well as metabolic, cellular, and molecular aspects, are comprehensively covered.

16.
Elife ; 122024 Feb 19.
Article in English | MEDLINE | ID: mdl-38372712

ABSTRACT

Septic shock is characterized by an excessive inflammatory response depicted in a cytokine storm that results from invasive bacterial, fungi, protozoa, and viral infections. Non-canonical inflammasome activation is crucial in the development of septic shock promoting pyroptosis and proinflammatory cytokine production via caspase-11 and gasdermin D (GSDMD). Here, we show that NAD+ treatment protected mice toward bacterial and lipopolysaccharide (LPS)-induced endotoxic shock by blocking the non-canonical inflammasome specifically. NAD+ administration impeded systemic IL-1ß and IL-18 production and GSDMD-mediated pyroptosis of macrophages via the IFN-ß/STAT-1 signaling machinery. More importantly, NAD+ administration not only improved casp-11 KO (knockout) survival but rendered wild type (WT) mice completely resistant to septic shock via the IL-10 signaling pathway that was independent from the non-canonical inflammasome. Here, we delineated a two-sided effect of NAD+ blocking septic shock through a specific inhibition of the non-canonical inflammasome and promoting immune homeostasis via IL-10, underscoring its unique therapeutic potential.


Subject(s)
Cytokines , Shock, Septic , Animals , Mice , Interleukin-10 , Inflammasomes , NAD , Shock, Septic/prevention & control , Macrophages
17.
Front Genet ; 14: 1145166, 2023.
Article in English | MEDLINE | ID: mdl-37576548

ABSTRACT

Introduction: Zoonotic transition of Influenza A viruses is the cause of epidemics with high rates of morbidity and mortality. Predicting which viral strains are likely to transition from their genetic sequence could help in the prevention and response against these zoonotic strains. We hypothesized that features predictive of viral hosts could be leveraged to identify biomarkers of zoonotic viral transition. Methods: We trained deep learning models to predict viral hosts based on the virus mRNA or protein sequences. Our multi-host dataset contained 848,630 unique nucleotide sequences obtained from the NCBI Influenza Virus and Influenza Research Databases. Each sequence, representing one gene from one viral strain, was classified into one of the three host categories: Avian, Human, and Swine. Trained models were analyzed using various neural network interpretation methods to identify interesting candidates for zoonotic transition biomarkers. Results: Using mRNA sequences as input led to higher prediction accuracies than amino acids, suggesting that the codon sequence contains information relevant to viral hosts that is lost during protein translation. UMAP visualization of the latent space of our classifiers showed that viral sequences clustered according to their host of origin. Interestingly, sequences from pandemic zoonotic viral strains localized at the margins between hosts, while zoonotic sequences incapable of Human-to-Human transmission localized with non-zoonotic viruses from the same host. In addition, host prediction for pandemic zoonotic sequences had low prediction accuracy, which was not the case for the other zoonotic strains. This supports our hypothesis that ambiguously predicted viral sequences bear features associated with cross-species infectivity. Finally, we compared misclassified sequences to well-classified ones to extract interesting candidates for zoonotic transition biomarkers. While features varied significantly between pairs of species and viral genes, several codons were conserved in Swine-to-Human and Avian-to-Human misclassified sequences, and in particular in the NA, HA, and NP genes, suggesting their importance for zoonosis in Humans. Discussion: Analysis of viral sequences using neural network interpretation approaches revealed important genetic differences between zoonotic viruses with pandemic potential, compared to non-zoonotic viral strains or zoonotic viruses incapable of Human-to-Human transmission.

18.
Mol Ther Nucleic Acids ; 31: 265-275, 2023 Mar 14.
Article in English | MEDLINE | ID: mdl-36700043

ABSTRACT

MicroRNA-10b (miR-10b) is an essential glioma driver and one of the top candidates for targeted therapies for glioblastoma and other cancers. This unique miRNA controls glioma cell cycle and viability via an array of established conventional and unconventional mechanisms. Previously reported CRISPR-Cas9-mediated miR-10b gene editing of glioma cells in vitro and established orthotopic glioblastoma in mouse models demonstrated the efficacy of this approach and its promise for therapy development. However, therapeutic gene editing in patients' brain tumors may be hampered, among other factors, by the imperfect delivery and distribution of targeting vectors. Here, we demonstrate that miR-10b gene editing in glioma cells triggers a potent bystander effect that leads to the selective cell death of the unedited glioma cells without affecting the normal neuroglial cells. The effect is mediated by the secreted miR-10b targets phosphoglycerate kinase 1 (PGK1) and insulin-like growth factor binding protein 2 (IGFBP2) that block cell-cycle progression and induce glioma cell death. These findings further support the feasibility of therapeutic miR-10b editing without the need to target every cell of the tumor.

19.
PLoS One ; 18(2): e0272781, 2023.
Article in English | MEDLINE | ID: mdl-36757991

ABSTRACT

Women's breast cancer is one of the most significant healthcare issues for the human race that demands a proactive strategy for a cure. In this study, the cytotoxic activity (MTT assay) of two natural steroidal compounds, protodioscin and dioscin, against two major subtypes of human breast cancer estrogen receptor-positive (ER-positive)/MCF-7 and triple-negative breast cancer (TNBC)/MDA-MB-468), was assessed. The clonogenic capacity was evaluated using the clonogenic assay. Oxidative stress was determined by measuring the formation of malondialdehyde and H2O2 and the assessment of total antioxidant enzyme activities (SOD, GPx, GR, and TrxR). Protodioscin and dioscin were highly cytotoxic against the tested cell lines (1.53 µM

Subject(s)
Antineoplastic Agents , Breast Neoplasms , Triple Negative Breast Neoplasms , Female , Humans , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Antioxidants/pharmacology , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Cell Line, Tumor , Cell Proliferation , Hydrogen Peroxide/pharmacology , Leukocytes, Mononuclear/metabolism , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/metabolism , Endoplasmic Reticulum/metabolism
20.
Front Immunol ; 14: 1188497, 2023.
Article in English | MEDLINE | ID: mdl-37564652

ABSTRACT

Innate immunity constitutes the first nonspecific immunological line of defense against infection. In this response, a variety of mechanisms are activated: the complement system, phagocytosis, and the inflammatory response. Then, adaptive immunity is activated. Major opsonization mediators during infections are immunoglobulins (Igs), the function of which is mediated through Fc receptors (FcRs). However, in addition to their role in adaptive immunity, FcRs have been shown to play a role in innate immunity by interacting directly with bacteria in the absence of their natural ligands (Igs). Additionally, it has been hypothesized that during the early phase of bacterial infection, FcRs play a protective role via innate immune functions mediated through direct recognition of bacteria, and as the infection progresses to later phases, FcRs exhibit their established function as receptors in adaptive immunity. This review provides detailed insight into the potential role of FcRs as innate immune mediators of the host defense against bacterial infection independent of opsonins.


Subject(s)
Immunity, Innate , Receptors, Fc , Phagocytosis , Immunoglobulins , Complement System Proteins
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