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1.
Chem Biol Drug Des ; 104(3): e14617, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39223105

ABSTRACT

Puerarin has been reported to have anticancer properties; however, its mechanism in regulating triple-negative breast cancer (TNBC) remains unclear. Cell function was assessed using a cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine assay, flow cytometry, and transwell assay. Additionally, the glucose assay kit, lactate assay kit, and ADP/ATP ratio assay kit were used to analyze glucose metabolism. mRNA and protein expression levels were analyzed using qRT-PCR and western blotting assays, respectively. The relationship between FUS RNA binding protein (FUS) and mitogen-activated protein kinase 4 (MAPK4) was determined using an RNA immunoprecipitation assay. TNBC cell malignancy in vitro was validated using a xenograft mouse model assay. Puerarin treatment or MAPK4 knockdown effectively inhibited TNBC cell proliferation, invasion, and glucose metabolism, and induced cell apoptosis. Additionally, puerarin treatment downregulated MAPK4 and FUS expression. Conversely, MAPK4 overexpression attenuated the effects of puerarin in TNBC cells. FUS stabilized MAPK4 mRNA expression in TNBC cells. Furthermore, puerarin decreased MAPK4 expression by downregulating FUS in TNBC cells. Finally, puerarin inhibited tumor formation in vivo. Puerarin inhibited TNBC development by decreasing the expression of FUS-dependent MAPK4, indicating that puerarin may serve as a promising therapeutic agent to hind TNBC.


Subject(s)
Cell Proliferation , Isoflavones , RNA-Binding Protein FUS , Triple Negative Breast Neoplasms , Isoflavones/pharmacology , Isoflavones/chemistry , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/pathology , Humans , Animals , Female , Cell Line, Tumor , Mice , Cell Proliferation/drug effects , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics , Apoptosis/drug effects , Mice, Nude , Xenograft Model Antitumor Assays , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry
2.
Head Neck Pathol ; 18(1): 70, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39102073

ABSTRACT

FUS::CREM fusion is a distinct primary driver in rare neoplasms of the head and neck and other anatomic sites. Herein, we describe the clinicopathological, imaging, and molecular features of a malignant epithelioid mesenchymal neoplasm harboring FUS::CREM fusion, arising in the tongue of a 46-year-old male. Clinically, the patient presented with a left upper neck mass. Imaging revealed a 4.0 cm mass at the left base of tongue. Histologically, the tumor consisted of sheets of loosely cohesive, small round to ovoid cells with moderate cytoplasm, small nuclei with coarse chromatin, frequent nuclear pseudoinclusions, and dense peripheral lymphoplasmacytic and histiocytic infiltrates. Malignant features, including tumor necrosis, perineural invasion, and increased mitotic activity were observed; however, lymphovascular invasion was absent with no evidence metastatic disease in the examined lymph nodes. A comprehensive panel of immunohistochemical stains showed positivity for synaptophysin and ALK, with negative results for all other markers. RNA-based next-generation sequencing using anchored multiplex polymerase chain reaction (PCR) was performed and detected FUS::CREM fusion gene. The patient was treated by excision and postsurgical chemoradiation with no evidence of recurrence after four months. Additional cases supported by comprehensive clinical data collected over an extended period are necessary to precisely characterize epithelioid mesenchymal neoplasms harboring FUS::CREM fusion in the head and neck.


Subject(s)
RNA-Binding Protein FUS , Tongue Neoplasms , Humans , Male , Middle Aged , Tongue Neoplasms/genetics , Tongue Neoplasms/pathology , RNA-Binding Protein FUS/genetics , Oncogene Proteins, Fusion/genetics , Mesenchymoma/genetics , Mesenchymoma/pathology
3.
Int J Mol Sci ; 25(15)2024 Aug 03.
Article in English | MEDLINE | ID: mdl-39126066

ABSTRACT

Pathogenic variations in the fused in sarcoma (FUS) gene are associated with rare and aggressive forms of amyotrophic lateral sclerosis (ALS). As FUS-ALS is a dominant disease, a targeted, allele-selective approach to FUS knockdown is most suitable. Antisense oligonucleotides (AOs) are a promising therapeutic platform for treating such diseases. In this study, we have explored the potential for allele-selective knockdown of FUS. Gapmer-type AOs targeted to two common neutral polymorphisms in FUS were designed and evaluated in human fibroblasts. AOs had either methoxyethyl (MOE) or thiomorpholino (TMO) modifications. We found that the TMO modification improved allele selectivity and efficacy for the lead sequences when compared to the MOE counterparts. After TMO-modified gapmer knockdown of the target allele, up to 93% of FUS transcripts detected were from the non-target allele. Compared to MOE-modified AOs, the TMO-modified AOs also demonstrated reduced formation of structured nuclear inclusions and SFPQ aggregation that can be triggered by phosphorothioate-containing AOs. How overall length and gap length of the TMO-modified AOs affected allele selectivity, efficiency and off-target gene knockdown was also evaluated. We have shown that allele-selective knockdown of FUS may be a viable therapeutic strategy for treating FUS-ALS and demonstrated the benefits of the TMO modification for allele-selective applications.


Subject(s)
Alleles , Amyotrophic Lateral Sclerosis , Oligonucleotides, Antisense , RNA-Binding Protein FUS , Humans , Oligonucleotides, Antisense/therapeutic use , Oligonucleotides, Antisense/genetics , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/drug therapy , Amyotrophic Lateral Sclerosis/therapy , RNA-Binding Protein FUS/genetics , Fibroblasts/metabolism , Fibroblasts/drug effects , Gene Knockdown Techniques , Morpholinos/therapeutic use , Morpholinos/genetics
4.
Mol Cell Biol ; 44(9): 391-409, 2024.
Article in English | MEDLINE | ID: mdl-39133076

ABSTRACT

Myogenesis is a highly orchestrated process whereby muscle precursor cells, myoblasts, develop into muscle fibers to form skeletal muscle during embryogenesis and regenerate adult muscle. Here, we studied the RNA-binding protein FUS (fused in sarcoma), which has been implicated in muscular and neuromuscular pathologies but is poorly characterized in myogenesis. Given that FUS levels declined in human and mouse models of skeletal myogenesis, and that silencing FUS enhanced myogenesis, we hypothesized that FUS might be a repressor of myogenic differentiation. Interestingly, overexpression of FUS delayed myogenesis, accompanied by slower production of muscle differentiation markers. To identify the mechanisms through which FUS inhibits myogenesis, we uncovered RNA targets of FUS by ribonucleoprotein immunoprecipitation (RIP) followed by RNA-sequencing (RNA-seq) analysis. Stringent selection of the bound transcripts uncovered Tnnt1 mRNA, encoding troponin T1 (TNNT1), as a major effector of FUS influence on myogenesis. We found that in myoblasts, FUS retained Tnnt1 mRNA in the nucleus, preventing TNNT1 expression; however, reduction of FUS during myogenesis or by silencing FUS released Tnnt1 mRNA for export to the cytoplasm, enabling TNNT1 translation and promoting myogenesis. We propose that FUS inhibits myogenesis by suppressing TNNT1 expression through a mechanism of nuclear Tnnt1 mRNA retention.


Subject(s)
Cell Differentiation , Muscle Development , Myoblasts , RNA-Binding Protein FUS , Troponin T , Muscle Development/genetics , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics , Animals , Mice , Humans , Troponin T/metabolism , Troponin T/genetics , Myoblasts/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Muscle, Skeletal/metabolism , Cell Line
5.
Cell Rep ; 43(8): 114626, 2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39167487

ABSTRACT

The majority of severe early-onset and juvenile cases of amyotrophic lateral sclerosis (ALS) are caused by mutations in the FUS gene, resulting in rapid disease progression. Mutant FUS accumulates within stress granules (SGs), thereby affecting the dynamics of these ribonucleoprotein complexes. Here, we define the interactome of the severe mutant FUSP525L variant in human induced pluripotent stem cell (iPSC)-derived motor neurons. We find increased interaction of FUSP525L with the PARP1 enzyme, promoting poly-ADP-ribosylation (PARylation) and binding of FUS to histone H1.2. Inhibiting PARylation or reducing H1.2 levels alleviates mutant FUS aggregation, SG alterations, and apoptosis in human motor neurons. Conversely, elevated H1.2 levels exacerbate FUS-ALS phenotypes, driven by the internally disordered terminal domains of H1.2. In C. elegans models, knockdown of H1.2 and PARP1 orthologs also decreases FUSP525L aggregation and neurodegeneration, whereas H1.2 overexpression worsens ALS-related changes. Our findings indicate a link between PARylation, H1.2, and FUS with potential therapeutic implications.


Subject(s)
Amyotrophic Lateral Sclerosis , Caenorhabditis elegans , Histones , Mutation , Poly (ADP-Ribose) Polymerase-1 , RNA-Binding Protein FUS , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/metabolism , Amyotrophic Lateral Sclerosis/pathology , Humans , Histones/metabolism , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics , Caenorhabditis elegans/metabolism , Caenorhabditis elegans/genetics , Animals , Mutation/genetics , Poly (ADP-Ribose) Polymerase-1/metabolism , Poly (ADP-Ribose) Polymerase-1/genetics , Motor Neurons/metabolism , Motor Neurons/pathology , Poly ADP Ribosylation , Induced Pluripotent Stem Cells/metabolism , Protein Binding
7.
Int J Mol Sci ; 25(16)2024 Aug 08.
Article in English | MEDLINE | ID: mdl-39201350

ABSTRACT

Post-translational modifications (PTMs) affecting proteins during or after their synthesis play a crucial role in their localization and function. The modification of these PTMs under pathophysiological conditions, i.e., their appearance, disappearance, or variation in quantity caused by a pathological environment or a mutation, corresponds to post-translational variants (PTVs). These PTVs can be directly or indirectly involved in the pathophysiology of diseases. Here, we present the PTMs and PTVs of four major amyotrophic lateral sclerosis (ALS) proteins, SOD1, TDP-43, FUS, and TBK1. These modifications involve acetylation, phosphorylation, methylation, ubiquitination, SUMOylation, and enzymatic cleavage. We list the PTM positions known to be mutated in ALS patients and discuss the roles of PTVs in the pathophysiological processes of ALS. In-depth knowledge of the PTMs and PTVs of ALS proteins is needed to better understand their role in the disease. We believe it is also crucial for developing new therapies that may be more effective in ALS.


Subject(s)
Amyotrophic Lateral Sclerosis , Protein Processing, Post-Translational , RNA-Binding Protein FUS , Superoxide Dismutase-1 , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/metabolism , Humans , Superoxide Dismutase-1/genetics , Superoxide Dismutase-1/metabolism , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Mutation , Animals , Phosphorylation , Acetylation
8.
Nat Commun ; 15(1): 6717, 2024 Aug 07.
Article in English | MEDLINE | ID: mdl-39112465

ABSTRACT

Biomolecular condensates are broadly implicated in both normal cellular regulation and disease. Consequently, several chemical biology and optogenetic approaches have been developed to induce phase separation of a protein of interest. However, few tools are available to perform the converse function - dissolving a condensate of interest on demand. Such a tool would aid in testing whether the condensate plays specific functional roles. Here we show that light-gated recruitment of a solubilizing domain, maltose-binding protein (MBP), results in rapid and controlled dissolution of condensates formed from proteins of interest. Our optogenetic MBP-based dissolution strategy (OptoMBP) is rapid, reversible, and can be spatially controlled with subcellular precision. We also provide a proof-of-principle application of OptoMBP by disrupting condensation of the oncogenic fusion protein FUS-CHOP and reverting FUS-CHOP driven transcriptional changes. We envision that the OptoMBP system could be broadly useful for disrupting constitutive protein condensates to probe their biological functions.


Subject(s)
Biomolecular Condensates , Light , Maltose-Binding Proteins , Optogenetics , RNA-Binding Protein FUS , Solubility , Maltose-Binding Proteins/metabolism , Maltose-Binding Proteins/chemistry , Maltose-Binding Proteins/genetics , Humans , Biomolecular Condensates/metabolism , Biomolecular Condensates/chemistry , Optogenetics/methods , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/chemistry , HeLa Cells
9.
Cell Mol Biol Lett ; 29(1): 95, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38956466

ABSTRACT

BACKGROUND: An increasing number of studies have demonstrated the association of circular RNAs (circRNAs) with the pathological processes of various diseases and their involvement in the onset and progression of multiple cancers. Nevertheless, the functional roles and underlying mechanisms of circRNAs in the autophagy regulation of gastric cancer (GC) have not been fully elucidated. METHODS: We used transmission electron microscopy and the mRFP-GFP-LC3 dual fluorescent autophagy indicator to investigate autophagy regulation. The cell counting kit-8 assay, colony formation assay, 5-ethynyl-2'-deoxyuridine incorporation assay, Transwell assay, and Western blot assay were conducted to confirm circPTPN22's influence on GC progression. Dual luciferase reporter assays validated the binding between circPTPN22 and miR-6788-5p, as well as miR-6788-5p and p21-activated kinase-1 (PAK1). Functional rescue experiments assessed whether circPTPN22 modulates PAK1 expression by competitively binding miR-6788-5p, affecting autophagy and other biological processes in GC cells. We investigated the impact of circPTPN22 on in vivo GC tumors using a nude mouse xenograft model. Bioinformatics tools predicted upstream regulatory transcription factors and binding proteins of circPTPN22, while chromatin immunoprecipitation and ribonucleoprotein immunoprecipitation assays confirmed the binding status. RESULTS: Upregulation of circPTPN22 in GC has been shown to inhibit autophagy and promote cell proliferation, migration, and invasion. Mechanistically, circPTPN22 directly binds to miR-6788-5p, subsequently regulating the expression of PAK1, which activates protein kinase B (Akt) and extracellular signal-regulated kinase (Erk) phosphorylation. This modulation ultimately affects autophagy levels in GC cells. Additionally, runt-related transcription factor 1 (RUNX1) negatively regulates circPTPN22 expression, while RNA-binding proteins such as FUS (fused in sarcoma) and ELAVL1 (recombinant ELAV-like protein 1) positively regulate its expression. Inhibition of the autophagy pathway can increase FUS expression, further upregulating circPTPN22 in GC cells, thereby exacerbating the progression of GC. CONCLUSION: Under the regulation of the transcription factor RUNX1 and RNA-binding proteins FUS and ELAVL1, circPTPN22 activates the phosphorylation of Akt and Erk through the miR-6788-5p/PAK1 axis, thereby modulating autophagy in GC cells. Inhibition of autophagy increases FUS, which in turn upregulates circPTPN22, forming a positive feedback loop that ultimately accelerates the progression of GC.


Subject(s)
Autophagy , Cell Movement , Cell Proliferation , Core Binding Factor Alpha 2 Subunit , ELAV-Like Protein 1 , MicroRNAs , RNA, Circular , RNA-Binding Protein FUS , Stomach Neoplasms , p21-Activated Kinases , Humans , Stomach Neoplasms/genetics , Stomach Neoplasms/pathology , Stomach Neoplasms/metabolism , RNA, Circular/genetics , RNA, Circular/metabolism , Autophagy/genetics , MicroRNAs/genetics , MicroRNAs/metabolism , p21-Activated Kinases/metabolism , p21-Activated Kinases/genetics , Cell Proliferation/genetics , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics , Cell Movement/genetics , Cell Line, Tumor , Animals , ELAV-Like Protein 1/metabolism , ELAV-Like Protein 1/genetics , Core Binding Factor Alpha 2 Subunit/metabolism , Core Binding Factor Alpha 2 Subunit/genetics , Gene Expression Regulation, Neoplastic , Mice, Nude , Mice , Neoplasm Invasiveness , Mice, Inbred BALB C
10.
Nat Commun ; 15(1): 5686, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38971830

ABSTRACT

The assembly and disassembly of biomolecular condensates are crucial for the subcellular compartmentalization of biomolecules in the control of cellular reactions. Recently, a correlation has been discovered between the phase transition of condensates and their maturation (aggregation) process in diseases. Therefore, modulating the phase of condensates to unravel the roles of condensation has become a matter of interest. Here, we create a peptide-based phase modulator, JSF1, which forms droplets in the dark and transforms into amyloid-like fibrils upon photoinitiation, as evidenced by their distinctive nanomechanical and dynamic properties. JSF1 is found to effectively enhance the condensation of purified fused in sarcoma (FUS) protein and, upon light exposure, induce its fibrilization. We also use JSF1 to modulate the biophysical states of FUS condensates in live cells and elucidate the relationship between FUS phase transition and FUS proteinopathy, thereby shedding light on the effect of protein phase transition on cellular function and malfunction.


Subject(s)
Peptides , Phase Transition , RNA-Binding Protein FUS , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/chemistry , RNA-Binding Protein FUS/genetics , Humans , Peptides/chemistry , Peptides/metabolism , Amyloid/metabolism , Amyloid/chemistry , Biomolecular Condensates/metabolism , Biomolecular Condensates/chemistry , Light
11.
Structure ; 32(7): 854-855, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38996511

ABSTRACT

In a recent issue of Nature Chemical Biology, Emmanouilidis et al. (2024) investigate the maturation of biomolecular condensates of FUS1-267 and probe the molecular details of droplet aging. They observe that the liquid-to-solid transition of the droplet is mediated at the surface by FUS1-267 molecules that have adopted ß-strand conformations.


Subject(s)
RNA-Binding Protein FUS , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/chemistry , Biophysics , Biomolecular Condensates/metabolism , Biomolecular Condensates/chemistry , Humans , Protein Conformation, beta-Strand
12.
Gen Physiol Biophys ; 43(4): 301-312, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38953570

ABSTRACT

Vascular endothelial growth factor A (VEGFA) is an important regulator for non-small cell lung cancer (NSCLC). Our study aimed to reveal its upstream pathway to provide new ideas for developing the therapeutic targets of NSCLC. The mRNA and protein levels of VEGFA, ubiquitin-specific peptidase 35 (USP35), and FUS were determined by quantitative real-time PCR and Western blot. Cell proliferation, apoptosis, invasion and angiogenesis were detected using CCK8 assay, EdU assay, flow cytometry, transwell assay and tube formation assay. The interaction between USP35 and VEGFA was assessed by Co-IP assay and ubiquitination assay. Animal experiments were performed to assess USP35 and VEGFA roles in vivo. VEGFA had elevated expression in NSCLC tissues and cells. Interferences of VEGFA inhibited NSCLC cell proliferation, invasion, angiogenesis, and increased apoptosis. USP35 could stabilize VEGFA protein level by deubiquitination, and USP35 knockdown suppressed NSCLC cell growth, invasion and angiogenesis via reducing VEGFA expression. FUS interacted with USP35 to promote its mRNA stability, thereby positively regulating VEGFA expression. Also, USP35 silencing could reduce NSCLC tumorigenesis by downregulating VEGFA. FUS-stabilized USP35 facilitated NSCLC cell growth, invasion and angiogenesis through deubiquitinating VEGFA, providing a novel idea for NSCLC treatment.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Cell Proliferation , Lung Neoplasms , Neoplasm Invasiveness , Neovascularization, Pathologic , RNA-Binding Protein FUS , Ubiquitination , Vascular Endothelial Growth Factor A , Humans , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factor A/genetics , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Lung Neoplasms/metabolism , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Cell Proliferation/genetics , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/genetics , Neoplasm Invasiveness/genetics , Cell Line, Tumor , Mice , Animals , Ubiquitin-Specific Proteases/metabolism , Ubiquitin-Specific Proteases/genetics , Mice, Nude , Angiogenesis
13.
J Gene Med ; 26(7): e3711, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38967638

ABSTRACT

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the death of upper and lower motor neurons with an unknown etiology. The difficulty of recovering biological material from patients led to employ lymphoblastoid cell lines (LCLs) as a model for ALS because many pathways, typically located in neurons, are also activated in these cells. METHODS: To investigate the expression of coding and long non-coding RNAs in LCLs, a transcriptomic profiling of sporadic ALS (SALS) and mutated patients (FUS, TARDBP, C9ORF72 and SOD1) and matched controls was realized. Thus, differentially expressed genes (DEGs) were investigated among the different subgroups of patients. Peripheral blood mononuclear cells (PBMCs) were isolated and immortalized into LCLs via Epstein-Barr virus infection; RNA was extracted, and RNA-sequencing analysis was performed. RESULTS: Gene expression profiles of LCLs were genetic-background-specific; indeed, only 12 genes were commonly deregulated in all groups. Nonetheless, pathways enriched by DEGs in each group were also compared, and a total of 89 Kyoto Encyclopedia of Genes and Genomes (KEGG) terms were shared among all patients. Eventually, the similarity of affected pathways was also assessed when our data were matched with a transcriptomic profile realized in the PBMCs of the same patients. CONCLUSIONS: We conclude that LCLs are a good model for the study of RNA deregulation in ALS.


Subject(s)
Amyotrophic Lateral Sclerosis , Gene Expression Profiling , Mutation , Transcriptome , Humans , Amyotrophic Lateral Sclerosis/genetics , Female , Male , Middle Aged , C9orf72 Protein/genetics , C9orf72 Protein/metabolism , Leukocytes, Mononuclear/metabolism , Superoxide Dismutase-1/genetics , Cell Line , Aged , Gene Expression Regulation , DNA-Binding Proteins , RNA-Binding Protein FUS
14.
Curr Opin Neurol ; 37(5): 560-569, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38967083

ABSTRACT

PURPOSE OF REVIEW: Amyotrophic lateral sclerosis (ALS) has a strong genetic basis, but the genetic landscape of ALS appears to be complex. The purpose of this article is to review recent developments in the genetics of ALS. RECENT FINDINGS: Large-scale genetic studies have uncovered more than 40 genes contributing to ALS susceptibility. Both rare variants with variable effect size and more common variants with small effect size have been identified. The most common ALS genes are C9orf72 , SOD1 , TARDBP and FUS . Some of the causative genes of ALS are shared with frontotemporal dementia, confirming the molecular link between both diseases. Access to diagnostic gene testing for ALS has to improve, as effective gene silencing therapies for some genetic subtypes of ALS are emerging, but there is no consensus about which genes to test for. SUMMARY: Our knowledge about the genetic basis of ALS has improved and the first effective gene silencing therapies for specific genetic subtypes of ALS are underway. These therapeutic advances underline the need for better access to gene testing for people with ALS. Further research is needed to further map the genetic heterogeneity of ALS and to establish the best strategy for gene testing in a clinical setting.


Subject(s)
Amyotrophic Lateral Sclerosis , C9orf72 Protein , Genetic Predisposition to Disease , RNA-Binding Protein FUS , Humans , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/diagnosis , C9orf72 Protein/genetics , Genetic Predisposition to Disease/genetics , RNA-Binding Protein FUS/genetics , Superoxide Dismutase-1/genetics , Superoxide Dismutase/genetics , Proteins/genetics , DNA-Binding Proteins/genetics , Genetic Testing
15.
Cell Rep ; 43(8): 114537, 2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39052476

ABSTRACT

Various ribonucleoprotein complexes (RNPs) often function in the form of membraneless organelles derived from multivalence-driven liquid-liquid phase separation (LLPS). Post-translational modifications, such as phosphorylation and arginine methylation, govern the assembly and disassembly of membraneless organelles. This study reveals that asymmetric dimethylation of arginine can create extra binding sites for multivalent Tudor domain-containing proteins like survival of motor neuron (SMN) protein, thereby lowering the threshold for LLPS of RNPs, such as fused in sarcoma (FUS). Accordingly, FUS hypomethylation or knockdown of SMN disrupts the formation and transport of neuronal granules in axons. Wild-type SMN, but not the spinal muscular atrophy-associated form of SMN, SMN-Δ7, rescues neuronal defects due to SMN knockdown. Importantly, a fusion of SMN-Δ7 to an exogenous oligomeric protein is sufficient to rescue axon length defects caused by SMN knockdown. Our findings highlight the significant role of arginine methylation-enabled multivalent interactions in LLPS and suggest their potential impact on various aspects of neuronal activities in neurodegenerative diseases.


Subject(s)
Arginine , Cytoplasmic Granules , RNA-Binding Protein FUS , RNA-Binding Protein FUS/metabolism , Arginine/metabolism , Methylation , Humans , Animals , Cytoplasmic Granules/metabolism , Mice , Neurons/metabolism , Axons/metabolism , Survival of Motor Neuron 1 Protein/metabolism , Survival of Motor Neuron 1 Protein/genetics , Phase Separation
16.
Mol Neurodegener ; 19(1): 46, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38862967

ABSTRACT

RNA binding proteins have emerged as central players in the mechanisms of many neurodegenerative diseases. In particular, a proteinopathy of fused in sarcoma (FUS) is present in some instances of familial Amyotrophic lateral sclerosis (ALS) and about 10% of sporadic Frontotemporal lobar degeneration (FTLD). Here we establish that focal injection of sonicated human FUS fibrils into brains of mice in which ALS-linked mutant or wild-type human FUS replaces endogenous mouse FUS is sufficient to induce focal cytoplasmic mislocalization and aggregation of mutant and wild-type FUS which with time spreads to distal regions of the brain. Human FUS fibril-induced FUS aggregation in the mouse brain of humanized FUS mice is accelerated by an ALS-causing FUS mutant relative to wild-type human FUS. Injection of sonicated human FUS fibrils does not induce FUS aggregation and subsequent spreading after injection into naïve mouse brains containing only mouse FUS, indicating a species barrier to human FUS aggregation and its prion-like spread. Fibril-induced human FUS aggregates recapitulate pathological features of FTLD including increased detergent insolubility of FUS and TAF15 and amyloid-like, cytoplasmic deposits of FUS that accumulate ubiquitin and p62, but not TDP-43. Finally, injection of sonicated FUS fibrils is shown to exacerbate age-dependent cognitive and behavioral deficits from mutant human FUS expression. Thus, focal seeded aggregation of FUS and further propagation through prion-like spread elicits FUS-proteinopathy and FTLD-like disease progression.


Subject(s)
Disease Progression , Frontotemporal Dementia , Mice, Transgenic , RNA-Binding Protein FUS , Animals , Humans , Mice , Amyotrophic Lateral Sclerosis/pathology , Amyotrophic Lateral Sclerosis/metabolism , Brain/metabolism , Brain/pathology , Disease Models, Animal , Frontotemporal Dementia/pathology , Frontotemporal Dementia/metabolism , Frontotemporal Dementia/genetics , Protein Aggregation, Pathological/metabolism , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics
17.
Acta Neuropathol Commun ; 12(1): 97, 2024 06 15.
Article in English | MEDLINE | ID: mdl-38879502

ABSTRACT

Wasteosomes (or corpora amylacea) are polyglucosan bodies that appear in the human brain with aging and in some neurodegenerative diseases, and have been suggested to have a potential role in a nervous system cleaning mechanism. Despite previous studies in several neurodegenerative disorders, their status in frontotemporal lobar degeneration (FTLD) remains unexplored. Our study aims to characterize wasteosomes in the three primary FTLD proteinopathies, assessing frequency, distribution, protein detection, and association with aging or disease duration. Wasteosome scores were obtained in various brain regions from 124 post-mortem diagnosed sporadic FTLD patients, including 75 participants with tau (FTLD-tau), 42 with TAR DNA-binding protein 43 (FTLD-TDP), and 7 with Fused in Sarcoma (FTLD-FUS) proteinopathies, along with 29 control subjects. The wasteosome amount in each brain region for the different FLTD patients was assessed with a permutation test with age at death and sex as covariables, and multiple regressions explored associations with age at death and disease duration. Double immunofluorescence studies examined altered proteins linked to FTLD in wasteosomes. FTLD patients showed a higher accumulation of wasteosomes than control subjects, especially those with FTLD-FUS. Unlike FTLD-TDP and control subjects, wasteosome accumulation did not increase with age in FTLD-tau and FTLD-FUS. Cases with shorter disease duration in FTLD-tau and FTLD-FUS seemed to exhibit higher wasteosome quantities, whereas FTLD-TDP appeared to show an increase with disease progression. Immunofluorescence studies revealed the presence of tau and phosphorylated-TDP-43 in the periphery of isolated wasteosomes in some patients with FTLD-tau and FTLD-TDP, respectively. Central inclusions of FUS were observed in a higher number of wasteosomes in FTLD-FUS patients. These findings suggest a role of wasteosomes in FTLD, especially in the more aggressive forms of FLTD-FUS. Detecting these proteins, particularly FUS, in wasteosomes from cerebrospinal fluid could be a potential biomarker for FTLD.


Subject(s)
DNA-Binding Proteins , Frontotemporal Lobar Degeneration , RNA-Binding Protein FUS , tau Proteins , Humans , Frontotemporal Lobar Degeneration/pathology , Frontotemporal Lobar Degeneration/metabolism , Female , Male , RNA-Binding Protein FUS/metabolism , Aged , tau Proteins/metabolism , Middle Aged , Aged, 80 and over , DNA-Binding Proteins/metabolism , Brain/pathology , Brain/metabolism
18.
Nat Commun ; 15(1): 5033, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38866783

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease due to gradual motoneurons (MN) degeneration. Among the processes associated to ALS pathogenesis, there is the formation of cytoplasmic inclusions produced by aggregation of mutant proteins, among which the RNA binding protein FUS. Here we show that, in neuronal cells and in iPSC-derived MN expressing mutant FUS, such inclusions are significantly reduced in number and dissolve faster when the RNA m6A content is diminished. Interestingly, stress granules formed in ALS conditions showed a distinctive transcriptome with respect to control cells, which reverted to similar to control after m6A downregulation. Notably, cells expressing mutant FUS were characterized by higher m6A levels suggesting a possible link between m6A homeostasis and pathological aggregates. Finally, we show that FUS inclusions are reduced also in patient-derived fibroblasts treated with STM-2457, an inhibitor of METTL3 activity, paving the way for its possible use for counteracting aggregate formation in ALS.


Subject(s)
Amyotrophic Lateral Sclerosis , Induced Pluripotent Stem Cells , Motor Neurons , RNA-Binding Protein FUS , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics , Amyotrophic Lateral Sclerosis/metabolism , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/pathology , Humans , Motor Neurons/metabolism , Motor Neurons/pathology , Induced Pluripotent Stem Cells/metabolism , Cytoplasmic Granules/metabolism , Fibroblasts/metabolism , Adenosine/metabolism , Adenosine/analogs & derivatives , Methyltransferases/metabolism , Methyltransferases/genetics , Mutation , Inclusion Bodies/metabolism , Stress Granules/metabolism , Transcriptome
19.
Dev Cell ; 59(16): 2134-2142.e6, 2024 Aug 19.
Article in English | MEDLINE | ID: mdl-38878774

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing, highly heterogeneous neurodegenerative disease, underscoring the importance of obtaining information to personalize clinical decisions quickly after diagnosis. Here, we investigated whether ALS-relevant signatures can be detected directly from biopsied patient fibroblasts. We profiled familial ALS (fALS) fibroblasts, representing a range of mutations in the fused in sarcoma (FUS) gene and ages of onset. To differentiate FUS fALS and healthy control fibroblasts, machine-learning classifiers were trained separately on high-content imaging and transcriptional profiles. "Molecular ALS phenotype" scores, derived from these classifiers, captured a spectrum from disease to health. Interestingly, these scores negatively correlated with age of onset, identified several pre-symptomatic individuals and sporadic ALS (sALS) patients with FUS-like fibroblasts, and quantified "movement" of FUS fALS and "FUS-like" sALS toward health upon FUS ASO treatment. Taken together, these findings provide evidence that non-neuronal patient fibroblasts can be used for rapid, personalized assessment in ALS.


Subject(s)
Amyotrophic Lateral Sclerosis , Fibroblasts , RNA-Binding Protein FUS , Humans , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/metabolism , Amyotrophic Lateral Sclerosis/pathology , Fibroblasts/metabolism , Fibroblasts/pathology , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics , Mutation/genetics , Male , Female , Skin/pathology , Skin/metabolism , Machine Learning , Middle Aged
20.
Nat Commun ; 15(1): 4893, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38849340

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a debilitating motor neuron disease and lacks effective disease-modifying treatments. This study utilizes a comprehensive multiomic approach to investigate the early and sex-specific molecular mechanisms underlying ALS. By analyzing the prefrontal cortex of 51 patients with sporadic ALS and 50 control subjects, alongside four transgenic mouse models (C9orf72-, SOD1-, TDP-43-, and FUS-ALS), we have uncovered significant molecular alterations associated with the disease. Here, we show that males exhibit more pronounced changes in molecular pathways compared to females. Our integrated analysis of transcriptomes, (phospho)proteomes, and miRNAomes also identified distinct ALS subclusters in humans, characterized by variations in immune response, extracellular matrix composition, mitochondrial function, and RNA processing. The molecular signatures of human subclusters were reflected in specific mouse models. Our study highlighted the mitogen-activated protein kinase (MAPK) pathway as an early disease mechanism. We further demonstrate that trametinib, a MAPK inhibitor, has potential therapeutic benefits in vitro and in vivo, particularly in females, suggesting a direction for developing targeted ALS treatments.


Subject(s)
Amyotrophic Lateral Sclerosis , Disease Models, Animal , MAP Kinase Signaling System , Mice, Transgenic , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/drug therapy , Amyotrophic Lateral Sclerosis/metabolism , Humans , Female , Animals , Male , Mice , MAP Kinase Signaling System/drug effects , Pyridones/pharmacology , Pyridones/therapeutic use , RNA-Binding Protein FUS/metabolism , RNA-Binding Protein FUS/genetics , Prefrontal Cortex/metabolism , Transcriptome , Superoxide Dismutase-1/genetics , Superoxide Dismutase-1/metabolism , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Middle Aged , MicroRNAs/genetics , MicroRNAs/metabolism , C9orf72 Protein/genetics , C9orf72 Protein/metabolism , Sex Characteristics , Aged , Sex Factors , Pyrimidinones
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