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1.
Prog Neurobiol ; 233: 102558, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38128822

ABSTRACT

Familial adult myoclonus epilepsy (FAME) is a neurological disorder caused by a TTTTA/TTTCA intronic repeat expansion. FAME4 is one of the six types of FAME that results from the repeat expansion in the first intron of the gene YEATS2. Although the RNA toxicity is believed to be the primary mechanism underlying FAME, the role of genes where repeat expansions reside is still unclear, particularly in the case of YEATS2 in neurons. This study used Drosophila to explore the effects of reducing YEATS2 expression. Two pan-neuronally driven dsDNA were used for knockdown of Drosophila YEATS2 (dYEATS2), and the resulting molecular and behavioural outcomes were evaluated. Drosophila with reduced dYEATS2 expression exhibited decreased tolerance to acute stress, disturbed locomotion, abnormal social behaviour, and decreased motivated activity. Additionally, reducing dYEATS2 expression negatively affected tyrosine hydroxylase (TH) gene expression, resulting in decreased dopamine biosynthesis. Remarkably, seizure-like behaviours induced by knocking down dYEATS2 were rescued by the administration of L-DOPA. This study reveals a novel role of YEATS2 in neurons in regulating acute stress responses, locomotion, and complex behaviours, and suggests that haploinsufficiency of YEATS2 may play a role in FAME4.


Subject(s)
Drosophila melanogaster , Epilepsies, Myoclonic , Animals , Drosophila melanogaster/genetics , Dopamine , Introns , Epilepsies, Myoclonic/genetics , Seizures/genetics
2.
Neurotherapeutics ; 20(5): 1330-1346, 2023 09.
Article in English | MEDLINE | ID: mdl-37493896

ABSTRACT

Pathogenic changes to TAR DNA-binding protein 43 (TDP-43) leading to alteration of its homeostasis are a common feature shared by several progressive neurodegenerative diseases for which there is no effective therapy. Here, we developed Drosophila lines expressing either wild type TDP-43 (WT) or that carrying an Amyotrophic Lateral Sclerosis /Frontotemporal Lobar Degeneration-associating G384C mutation that recapitulate several aspects of the TDP-43 pathology. To identify potential therapeutics for TDP-43-related diseases, we implemented a drug repurposing strategy that involved three consecutive steps. Firstly, we evaluated the improvement of eclosion rate, followed by the assessment of locomotive functions at early and late developmental stages. Through this approach, we successfully identified fingolimod, as a promising candidate for modulating TDP-43 toxicity. Fingolimod exhibited several beneficial effects in both WT and mutant models of TDP-43 pathology, including post-transcriptional reduction of TDP-43 levels, rescue of pupal lethality, and improvement of locomotor dysfunctions. These findings provide compelling evidence for the therapeutic potential of fingolimod in addressing TDP-43 pathology, thereby strengthening the rationale for further investigation and consideration of clinical trials. Furthermore, our study demonstrates the utility of our Drosophila-based screening pipeline in identifying novel therapeutics for TDP-43-related diseases. These findings encourage further scale-up screening endeavors using this platform to discover additional compounds with therapeutic potential for TDP-43 pathology.


Subject(s)
Amyotrophic Lateral Sclerosis , TDP-43 Proteinopathies , Animals , Amyotrophic Lateral Sclerosis/genetics , DNA-Binding Proteins/genetics , Drosophila/metabolism , Drug Repositioning , Fingolimod Hydrochloride/therapeutic use , TDP-43 Proteinopathies/pathology
3.
Cell Mol Life Sci ; 79(3): 183, 2022 Mar 12.
Article in English | MEDLINE | ID: mdl-35279775

ABSTRACT

The so-called Yaf9, ENL, AF9, Taf14, and Sas5 (YEATS) domain-containing proteins, hereafter referred to as YD proteins, take control over the transcription by multiple steps of regulation either involving epigenetic remodelling of chromatin or guiding the processivity of RNA polymerase II to facilitate elongation-coupled mRNA 3' processing. Interestingly, an increasing amount of evidence suggest a wider repertoire of YD protein's functions spanning from non-coding RNA regulation, RNA-binding proteins networking, post-translational regulation of a few signalling transduction proteins and the spindle pole formation. However, such a large set of non-canonical roles is still poorly characterized. Notably, four paralogous of human YEATS domain family members, namely eleven-nineteen-leukaemia (ENL), ALL1-fused gene from chromosome 9 protein (AF9), YEATS2 and glioma amplified sequence 41 (GAS41), have a strong link to cancer yet new findings also highlight a potential novel role in neurological diseases. Here, in an attempt to more comprehensively understand the complexity of four YD proteins and to gain more insight into the novel functions they may accomplish in the neurons, we summarized the YD protein's networks, systematically searched and reviewed the YD genetic variants associated with neurodevelopmental disorders and finally interrogated the model organism Drosophila melanogaster.


Subject(s)
Chromosomal Proteins, Non-Histone/metabolism , Nervous System Diseases/pathology , Transcription Factors/metabolism , Transcriptional Elongation Factors/metabolism , Animals , Chromosomal Proteins, Non-Histone/chemistry , Chromosomal Proteins, Non-Histone/genetics , Drosophila Proteins/chemistry , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Epigenesis, Genetic , Evolution, Molecular , Humans , Nervous System Diseases/metabolism , Protein Domains , Transcription Factors/chemistry , Transcription Factors/genetics , Transcriptional Elongation Factors/chemistry , Transcriptional Elongation Factors/genetics
4.
Trop Med Int Health ; 26(11): 1401-1410, 2021 11.
Article in English | MEDLINE | ID: mdl-34478609

ABSTRACT

OBJECTIVE: Germline mutations of the TP53 tumour suppressor gene are the only known cause of the hereditary autosomal disorder called Li-Fraumeni syndrome (LFS). However, little information is available about TP53 pathogenic variants in Asian LFS patients, making it difficult to provide precise genetic counselling with regard to long-term cancer risk. We conducted a systematic review to gather relevant case-control studies exploring the association between TP53 polymorphisms and the incidence of cancer belonging to the LFS spectrum in Asian populations. METHOD: Systematic review and meta-analysis. The odds ratio was used as a summary effect measure to quantify the strength of the association between TP53 polymorphisms and cancer risk by means of random-effects meta-analysis. RESULTS: In total, 16 studies were included in this systematic review, with 13 studies (involving 10,645 cases and 28,288 controls) that enabled meta-analysis. The majority of the studies focused on a single-nucleotide variation at codon 72 in exon 4 (c.215C>G, p.Arg72Pro, rs1042522). Therefore, we tested either dominant, co-dominant, recessive, or heterozygous models and found that the p.Arg72Pro was not significantly associated with increased cancer risk in any of the models. CONCLUSION: We found the number of studies on cancers belonging to the LFS spectrum in Asia is very small. Thus, at the present time a meta-analysis approach is somewhat useful to identify germline TP53 mutations as potential markers of hereditary cancer associated with LFS in Asian populations.


Subject(s)
Genetic Predisposition to Disease , Li-Fraumeni Syndrome/genetics , Tumor Suppressor Protein p53/genetics , Asia/epidemiology , Asian People , Germ-Line Mutation , Humans , Li-Fraumeni Syndrome/epidemiology , Polymorphism, Single Nucleotide
5.
Cancers (Basel) ; 13(16)2021 Aug 21.
Article in English | MEDLINE | ID: mdl-34439367

ABSTRACT

Circulating cell-free nucleic acids recently became attractive targets to develop non-invasive diagnostic tools for cancer detection. Along with DNA and mRNAs, transcripts lacking coding potential (non-coding RNAs, ncRNAs) directly involved in the process of tumor pathogenesis have been recently detected in liquid biopsies. Interestingly, circulating ncRNAs exhibit specific expression patterns associated with cancer and suggest their role as novel biomarkers. However, the potential of circulating long ncRNAs (c-lncRNAs) to be markers in osteosarcoma (OS) is still elusive. In this study we performed a systematic review to identify thirteen c-lncRNAs whose altered expression in blood associate with OS. We herein discuss the potential impact that these c-lncRNAs may have on clinical decision-making in the management of OS. Overall, we aimed to provide novel insights that can contribute to the development of future precision medicine in oncology.

6.
Front Pharmacol ; 12: 628198, 2021.
Article in English | MEDLINE | ID: mdl-33995026

ABSTRACT

Allergic rhinitis (AR) is considered a major nasal condition impacting a large number of people around the world, and it is now becoming a global health problem. Because the underlying mechanisms of AR are complex, the development of single-drug treatment might not be enough to treat a wide spectrum of the disease. Although the standard guidelines classify and provide suitable diagnosis and treatment, the vast majority of people with AR are still without any means of controlling it. Moreover, the benefits of AR drugs are sometimes accompanied by undesirable side effects. Thus, it is becoming a significant challenge to find effective therapies with limited undesirable side effects for a majority of patients suffering from uncontrolled AR. Aller-7/NR-A2, a polyherbal formulation, has revealed promising results in patients by reducing nasal symptoms and eosinophil counts without serious adverse effects. Interestingly, three out of seven of the herbals in the Aller-7/NR-A2 formulation are also found in an Ayurvedic polyherbal formulation known as "Triphala," which is a potential candidate for the treatment of AR. However, there are no current studies that have examined the effects of Triphala on the disease. This review aims to describe the complexity of AR pathophysiology, currently available treatments, and the effects of Triphala on AR in order to help develop it as a promising alternative treatment in the future.

7.
Biology (Basel) ; 10(4)2021 Apr 01.
Article in English | MEDLINE | ID: mdl-33916174

ABSTRACT

Many medicinal plants have been used to treat wounds. Here, we revealed the potential wound healing effects of Curcuma amarissima (CA). Our cell viability assay showed that CA extract increased the viability of HaCaT cells that were cultured in the absence of serum. This increase in cell viability was proved to be associated with the pharmacological activities of CA extract in inducing cell proliferation. To further define possible molecular mechanisms of action, we performed Western blot analysis and immunofluorescence study, and our data demonstrated that CA extract rapidly induced ERK1/2 and Akt activation. Consistently, CA extract accelerated cell migration, resulting in rapid healing of wounded human keratinocyte monolayer. Specifically, the CA-induced increase of cell monolayer wound healing was blocked by the MEK inhibitor (U0126) or the PI3K inhibitor (LY294002). Moreover, CA extract induced the expression of Mcl-1, which is an anti-apoptotic protein, supporting that CA extract enhances human keratinocyte survival. Taken together, our study provided convincing evidence that Curcuma amarissima can promote proliferation and survival of human keratinocyte through stimulating the MAPK and PI3K/Akt signaling cascades. These promising data emphasize the possibility to develop this plant as a wound healing agent for the potential application in regenerative medicine.

8.
Exp Cell Res ; 403(1): 112584, 2021 06 01.
Article in English | MEDLINE | ID: mdl-33812867

ABSTRACT

Drosophila is emerging as a convenient model for investigating human diseases. Functional homologues of almost 75% of human disease-related genes are found in Drosophila. Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease that causes defects in motoneurons. Charcot-Marie-Tooth disease (CMT) is one of the most commonly found inherited neuropathies affecting both motor and sensory neurons. No effective therapy has been established for either of these diseases. In this review, after overviewing ALS, Drosophila models targeting several ALS-causing genes, including TDP-43, FUS and Ubiquilin2, are described with their genetic interactants. Then, after overviewing CMT, examples of Drosophila models targeting several CMT-causing genes, including mitochondria-related genes and FIG 4, are also described with their genetic interactants. In addition, we introduce Sotos syndrome caused by mutations in the epigenetic regulator gene NSD1. Lastly, several genes and pathways that commonly interact with ALS- and/or CMT-causing genes are described. In the case of ALS and CMT that have many causative genes, it may be not practical to perform gene therapy for each of the many disease-causing genes. The possible uses of the common genes and pathways as novel diagnosis markers and effective therapeutic targets are discussed.


Subject(s)
Amyotrophic Lateral Sclerosis/metabolism , Charcot-Marie-Tooth Disease/metabolism , Motor Neurons/metabolism , Neurodegenerative Diseases/metabolism , Amyotrophic Lateral Sclerosis/genetics , Animals , Charcot-Marie-Tooth Disease/genetics , DNA-Binding Proteins/metabolism , Drosophila/metabolism , Humans
9.
Wiley Interdiscip Rev RNA ; 12(6): e1661, 2021 11.
Article in English | MEDLINE | ID: mdl-33913612

ABSTRACT

In the last decade, an intriguing new paradigm of regulation has emerged in which some transcripts longer than 200 nucleotides and no coding potential, long noncoding RNA (lncRNAs), exhibit the capability to control posttranslational modifications of nonhistone proteins in both invertebrates and vertebrates. The extent of such a regulation is still largely unknown. We performed a systematic review to identify and evaluate the potential impact of lncRNA-dependent methylation of nonhistone proteins. Collectively, these lncRNAs primarily act as scaffolds upon which methyltransferases (MTases) and targets are brought in proximity. In this manner, the N-MTase activity of EZH2, protein arginine-MTase 1/4/5, and SMYD2 is exploited to modulate the stability or the compartmentalization of several nonhistone proteins with roles in cell signaling, gene expression, and RNA processing. Moreover, these lncRNAs can indirectly affect the methylation of nonhistone proteins by transcriptional or posttranscriptional regulation of MTases. Strikingly, the lncRNAs/MTases/nonhistone proteins networking seem to be relevant to carcinogenesis and neurological disorders. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.


Subject(s)
RNA, Long Noncoding , Animals , Gene Expression Regulation , Methylation , Protein Processing, Post-Translational , RNA Processing, Post-Transcriptional , RNA, Long Noncoding/genetics
10.
BMC Complement Med Ther ; 20(1): 267, 2020 Aug 31.
Article in English | MEDLINE | ID: mdl-32867756

ABSTRACT

BACKGROUND: Mutations in the human Ubiquilin 2 gene are associated with neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) with or without frontotemporal dementia (FTD), the fatal neurodegenerative disease that progressively affected neuronal cells in both brain and spinal cord. There is currently no effective therapy for these diseases. Over the last decade, researchers have focused on the potential use of natural products especially in neurodegenerative studies. Insect products have been used as traditional medicines, however, scientific information is still lacking. Fruit fly is recently used as a model organism to investigate degenerative diseases related to the nervous system because it has a short life span and produces a large number of offspring. METHODS: The present study investigated the effects of honeybee products and edible insect powders on the locomotive and learning abilities, neuromuscular junctions (NMJs) structure, and reactive oxygen species (ROS) in larval brains of Ubiquilin- knockdown Drosophila. RESULTS: dUbqn knockdown flies showed defects in locomotive and learning abilities accompanied with structural defects in NMJs. The results obtained revealed that the recovery of locomotive defects was significantly greater in dUbqn knockdown flies fed with coffee honey from Apis cerana (1% v/v) or Apis dorsata melittin (0.5 µg/ml) or wasp powder (2 mg/ml) than that of in untreated dUbqn knockdown flies. Furthermore, dUbqn knockdown flies fed with coffee honey showed the partial rescue of structural defects in NMJs, improved learning ability, and reduced the accumulation of ROS caused by dUbqn depletion in the brain over the untreated group. CONCLUSION: These results suggest that coffee honey from Apis cerana contains a neuroprotective agent that will contribute to the development of a novel treatment for ALS/FTD.


Subject(s)
Apitherapy/methods , Edible Insects , Locomotion/drug effects , Neurodegenerative Diseases/drug therapy , Animals , Bees , Drosophila , Female , Powders , Thailand
11.
Cancers (Basel) ; 12(6)2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32549375

ABSTRACT

Ubiquilins or UBQLNs, members of the ubiquitin-like and ubiquitin-associated domain (UBL-UBA) protein family, serve as adaptors to coordinate the degradation of specific substrates via both proteasome and autophagy pathways. The UBQLN substrates reveal great diversity and impact a wide range of cellular functions. For decades, researchers have been attempting to uncover a puzzle and understand the role of UBQLNs in human cancers, particularly in the modulation of oncogene's stability and nucleotide excision repair. In this review, we summarize the UBQLNs' genetic variants that are associated with the most common cancers and also discuss their reliability as a prognostic marker. Moreover, we provide an overview of the UBQLNs networks that are relevant to cancers in different ways, including cell cycle, apoptosis, epithelial-mesenchymal transition, DNA repairs and miRNAs. Finally, we include a future prospective on novel ubiquilin-based cancer therapies.

12.
Sci Rep ; 10(1): 5689, 2020 03 30.
Article in English | MEDLINE | ID: mdl-32231214

ABSTRACT

Drosophila melanogaster is a useful and highly tractable model organism for understanding the molecular mechanisms of human diseases. We previously characterized a new dUbqn knockdown model that induces learning-memory and locomotive deficits mediated by impaired proteostasis. Although proteinopathies are the main causes of neurodegenerative diseases, limited information is currently available on the relationship between proteostasis and neurodegenerative-related behavioral perturbations, such as locomotion, wakefulness, and sexual activities. Thus, the present study aimed to elucidate the mechanisms by which dUbqn depletion which is known to cause proteinopathies, affects neurodegenerative-related behavioral perturbations. Pan-neuronal dUbqn-depleted flies showed significantly reduced evening activity along with altered pre- and postsynaptic structural NMJ's proteins by attenuating signals of Bruchpilot puncta and GluRIIA clustering. In addition, the neurochemical profiles of GABA, glutamate, dopamine, and serotonin were disturbed and these changes also affected courtship behaviors in dUbqn-depleted flies. Collectively, these results extend our understanding on how dUbqn depletion affects neurochemical regulation to drive behavioral disturbances that are generally found in the early stage of neurodegenerative diseases. Moreover, the present study may contribute a novel finding to the design of new agents that prevent disease progression or even treat diseases related to neurodegeneration.


Subject(s)
Drosophila melanogaster/metabolism , Ubiquitin/deficiency , Animals , Courtship , Dopamine/metabolism , Dopamine/physiology , Drosophila melanogaster/physiology , Female , Gas Chromatography-Mass Spectrometry , Glutamic Acid/metabolism , Glutamic Acid/physiology , Larva , Male , Mass Spectrometry , Motor Activity/physiology , Nervous System/metabolism , Nervous System/physiopathology , Neurodegenerative Diseases/metabolism , Neurodegenerative Diseases/physiopathology , Neuromuscular Junction/metabolism , Neuromuscular Junction/physiology , Serotonin/metabolism , Serotonin/physiology , Tandem Mass Spectrometry , Ubiquitin/metabolism , Ubiquitin/physiology , gamma-Aminobutyric Acid/metabolism , gamma-Aminobutyric Acid/physiology
13.
Int J Mol Sci ; 21(5)2020 Mar 03.
Article in English | MEDLINE | ID: mdl-32138327

ABSTRACT

Neuronal insulin resistance is a significant feature of Alzheimer's disease (AD). Accumulated evidence has revealed the possible neuroprotective mechanisms of antidiabetic drugs in AD. Liraglutide, a glucagon-like peptide-1 (GLP-1) analog and an antidiabetic agent, has a benefit in improving a peripheral insulin resistance. However, the neuronal effect of liraglutide on the model of neuronal insulin resistance with Alzheimer's formation has not been thoroughly investigated. The present study discovered that liraglutide alleviated neuronal insulin resistance and reduced beta-amyloid formation and tau hyperphosphorylation in a human neuroblostoma cell line, SH-SY5Y. Liraglutide could effectively reverse deleterious effects of insulin overstimulation. In particular, the drug reversed the phosphorylation status of insulin receptors and its major downstream signaling molecules including insulin receptor substrate 1 (IRS-1), protein kinase B (AKT), and glycogen synthase kinase 3 beta (GSK-3ß). Moreover, liraglutide reduced the activity of beta secretase 1 (BACE-1) enzyme, which then decreased the formation of beta-amyloid in insulin-resistant cells. This indicated that liraglutide can reverse the defect of phosphorylation status of insulin signal transduction but also inhibit the formation of pathogenic Alzheimer's proteins like Aß in neuronal cells. We herein provided the possibility that the liraglutide-based therapy may be able to reduce such deleterious effects caused by insulin resistance. In view of the beneficial effects of liraglutide administration, these findings suggest that the use of liraglutide may be a promising therapy for AD with insulin-resistant condition.


Subject(s)
Amyloid beta-Peptides/metabolism , Insulin/metabolism , Liraglutide/therapeutic use , tau Proteins/metabolism , Alzheimer Disease/metabolism , Amyloid Precursor Protein Secretases/metabolism , Aspartic Acid Endopeptidases/metabolism , Blotting, Western , Cell Line, Tumor , Cell Survival/drug effects , Glucagon-Like Peptide 1/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Humans , Immunoprecipitation , Insulin Receptor Substrate Proteins/metabolism , Phosphorylation/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects
14.
Int J Mol Sci ; 20(24)2019 Dec 13.
Article in English | MEDLINE | ID: mdl-31847284

ABSTRACT

: Salacia chinensis L. (SC) stems have been used as an ingredient in Thai traditional medicine for treating patients with hepatic fibrosis and liver cirrhosis. However, there is no scientific evidence supporting the antifibrotic effects of SC extract. Therefore, this study aimed to determine the antifibrotic activity of SC stem extract in human hepatic stellate cell-line called LX-2. We found that upon TGF-ß1 stimulation, LX-2 cells transformed to a myofibroblast-like phenotype with a noticeable increase in α-SMA and collagen type I production. Interestingly, cells treated with SC extract significantly suppressed α-SMA and collagen type I production and reversed the myofibroblast-like characteristics back to normal. Additionally, TGF-ß1 also influenced the development of fibrogenesis by upregulation of MMP-2, TIMP-1, and TIMP-2 and related cellular signaling, such as pSmad2/3, pErk1/2, and pJNK. Surprisingly, SC possesses antifibrotic activity through the suppression of TGF-ß1-mediated production of collagen type 1, α-SMA, and the phosphorylation status of Smad2/3, Erk1/2, and JNK. Taken together, the present study provides accumulated information demonstrating the antifibrotic effects of SC stem extract and revealing its potential for development for hepatic fibrosis patients.


Subject(s)
Hepatic Stellate Cells/metabolism , Liver Cirrhosis/drug therapy , MAP Kinase Signaling System/drug effects , Plant Extracts/pharmacology , Plant Stems/chemistry , Salacia/chemistry , Smad2 Protein/metabolism , Smad3 Protein/metabolism , Transforming Growth Factor beta1/metabolism , Cell Line , Hepatic Stellate Cells/pathology , Humans , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Plant Extracts/chemistry
15.
Int J Mol Sci ; 20(8)2019 Apr 17.
Article in English | MEDLINE | ID: mdl-30999567

ABSTRACT

Ubiquitin-like/ubiquitin-associated proteins (UbL-UbA) are a well-studied family of non-proteasomal ubiquitin receptors that are evolutionarily conserved across species. Members of this non-homogenous family facilitate and support proteasomal activity by promoting different effects on proteostasis but exhibit diverse extra-proteasomal activities. Dysfunctional UbL-UbA proteins render cells, particularly neurons, more susceptible to stressors or aging and may cause earlier neurodegeneration. In this review, we summarized the properties and functions of UbL-UbA family members identified to date, with an emphasis on new findings obtained using Drosophila models showing a direct or indirect role in some neurodegenerative diseases.


Subject(s)
Neurodegenerative Diseases/metabolism , Neurons/pathology , Ubiquitin/metabolism , Ubiquitins/metabolism , Adaptor Proteins, Signal Transducing , Animals , Autophagy-Related Proteins , Carrier Proteins/metabolism , Cell Cycle Proteins/metabolism , DNA Repair Enzymes/metabolism , DNA-Binding Proteins/metabolism , Disease Models, Animal , Drosophila , Humans , Intracellular Signaling Peptides and Proteins/metabolism , Neurodegenerative Diseases/pathology , Neurons/metabolism , Proteasome Endopeptidase Complex/metabolism , Proteostasis , Transcription Factors/metabolism , Ubiquitin-Protein Ligases
16.
Biochim Biophys Acta Mol Basis Dis ; 1865(6): 1579-1591, 2019 06 01.
Article in English | MEDLINE | ID: mdl-30904609

ABSTRACT

Evolutionarily conserved homeostatic systems have been shown to modulate synaptic efficiency at the neuromuscular junctions of organisms. While advances have been made in identifying molecules that function presynaptically during homeostasis, limited information is currently available on how postsynaptic alterations affect presynaptic function. We previously identified a role for postsynaptic Dystrophin in the maintenance of evoked neurotransmitter release. We herein demonstrated that Dystrobrevin, a member of the Dystrophin Glycoprotein Complex, was delocalized from the postsynaptic region in the absence of Dystrophin. A newly-generated Dystrobrevin mutant showed elevated evoked neurotransmitter release, increased bouton numbers, and a readily releasable pool of synaptic vesicles without changes in the function or numbers of postsynaptic glutamate receptors. In addition, we provide evidence to show that the highly conserved Cdc42 Rho GTPase plays a key role in the postsynaptic Dystrophin/Dystrobrevin pathway for synaptic homeostasis. The present results give novel insights into the synaptic deficits underlying Duchenne Muscular Dystrophy affected by a dysfunctional Dystrophin Glycoprotein complex.


Subject(s)
Drosophila Proteins/genetics , Drosophila melanogaster/genetics , Dystrophin-Associated Proteins/genetics , Dystrophin/genetics , Neuromuscular Junction/genetics , cdc42 GTP-Binding Protein/genetics , Animals , Animals, Genetically Modified , Disease Models, Animal , Drosophila Proteins/metabolism , Drosophila melanogaster/metabolism , Dystrophin/deficiency , Dystrophin-Associated Proteins/metabolism , Gene Expression Regulation , Homeostasis/genetics , Humans , Muscular Dystrophy, Duchenne/genetics , Muscular Dystrophy, Duchenne/metabolism , Muscular Dystrophy, Duchenne/pathology , Neuromuscular Junction/metabolism , Neuromuscular Junction/pathology , Synaptic Potentials/genetics , Synaptic Transmission , Synaptic Vesicles/metabolism , cdc42 GTP-Binding Protein/metabolism
17.
Brain Res ; 1712: 158-166, 2019 06 01.
Article in English | MEDLINE | ID: mdl-30711401

ABSTRACT

The Drosophila olfactory system provides an excellent model to elucidate the neural circuits that control behaviors elicited by environmental stimuli. Despite significant progress in defining olfactory circuit components and their connectivity, little is known about the mechanisms that transfer the information from the primary antennal olfactory receptor neurons to the higher order brain centers. Here, we show that the Dystrophin Dp186 isoform is required in the olfactory system circuit for olfactory functions. Using two-photon calcium imaging, we found the reduction of calcium influx in olfactory receptor neurons (ORNs) and also the defect of GABAA mediated inhibitory input in the projection neurons (PNs) in Dp186 mutation. Moreover, the Dp186 mutant flies which display a decreased odor avoidance behavior were rescued by Dp186 restoration in the Drosophila olfactory neurons in either the presynaptic ORNs or the postsynaptic PNs. Therefore, these results revealed a role for Dystrophin, Dp 186 isoform in gain control of the olfactory synapse via the modulation of excitatory and inhibitory synaptic inputs to olfactory projection neurons.


Subject(s)
Dystrophin/metabolism , Olfactory Pathways/physiology , Smell/physiology , Animals , Calcium/metabolism , Drosophila Proteins/metabolism , Drosophila melanogaster/metabolism , Dystrophin/physiology , Female , Interneurons/metabolism , Male , Odorants , Olfactory Perception/physiology , Olfactory Receptor Neurons/physiology , Synapses/physiology
18.
Biochim Biophys Acta Mol Basis Dis ; 1864(9 Pt B): 3038-3049, 2018 09.
Article in English | MEDLINE | ID: mdl-29936333

ABSTRACT

The proteostasis machinery has critical functions in metabolically active cells such as neurons. Ubiquilins (UBQLNs) may decide the fate of proteins, with its ability to bind and deliver ubiquitinated misfolded or no longer functionally required proteins to the ubiquitin-proteasome system (UPS) and/or autophagy. Missense mutations in UBQLN2 have been linked to X-linked dominant amyotrophic lateral sclerosis with frontotemporal dementia (ALS-FTD). Although aggregation-prone TAR DNA-binding protein 43 (TDP-43) has been recognized as a major component of the ubiquitin pathology, the mechanisms by which UBQLN involves in TDP-43 proteinopathy have not yet been elucidated in detail. We previously characterized a new Drosophila Ubiquilin (dUbqn) knockdown model that produces learning/memory and locomotive deficits during the proteostasis impairment. In the present study, we demonstrated that the depletion of dUbqn markedly affected the expression and sub-cellular localization of Drosophila TDP-43 (TBPH), resulting in a cytoplasmic ubiquitin-positive (Ub+) TBPH pathology. Although we found that the knockdown of dUbqn widely altered and affected the turnover of a large number of proteins, we herein showed that an augmented soluble cytoplasmic Ub+-TBPH is as a crucial source of neurotoxicity following the depletion of dUbqn. We demonstrated that dUbqn knockdown-related neurotoxicity may be rescued by either restoring the proteostasis machinery or reducing the expression of TBPH. These novel results extend our knowledge on the UBQLN loss-of-function pathomechanism and may contribute to the identification of new therapeutics for ALS-FTD and aging-related diseases.


Subject(s)
Carrier Proteins/metabolism , Cell Cycle Proteins/metabolism , DNA-Binding Proteins/metabolism , Drosophila Proteins/metabolism , TDP-43 Proteinopathies/pathology , Animals , Animals, Genetically Modified , Carrier Proteins/genetics , Cell Cycle Proteins/genetics , Disease Models, Animal , Drosophila , Gene Knockdown Techniques , Male , TDP-43 Proteinopathies/genetics , Ubiquitin/metabolism , Ubiquitination/genetics , Valosin Containing Protein/metabolism
19.
Exp Cell Res ; 362(2): 461-471, 2018 01 15.
Article in English | MEDLINE | ID: mdl-29247619

ABSTRACT

Ubiquilin (UBQLN) plays a crucial role in cellular proteostasis through its involvement in the ubiquitin proteasome system and autophagy. Mutations in the UBQLN2 gene have been implicated in amyotrophic lateral sclerosis (ALS) and ALS with frontotemporal lobar dementia (ALS/FTLD). Previous studies reported a key role for UBQLN in Alzheimer's disease (AD); however, the mechanistic involvement of UBQLN in other neurodegenerative diseases remains unclear. The genome of Drosophila contains a single UBQLN homolog (dUbqn) that shows high similarity to UBQLN1 and UBQLN2; therefore, the fly is a useful model for characterizing the role of UBQLN in vivo in neurological disorders affecting locomotion and learning abilities. We herein performed a phenotypic and molecular characterization of diverse dUbqn RNAi lines. We found that the depletion of dUbqn induced the accumulation of polyubiquitinated proteins and caused morphological defects in various tissues. Our results showed that structural defects in larval neuromuscular junctions, abdominal neuromeres, and mushroom bodies correlated with limited abilities in locomotion, learning, and memory. These results contribute to our understanding of the impact of impaired proteostasis in neurodegenerative diseases and provide a useful Drosophila model for the development of promising therapies for ALS and FTLD.


Subject(s)
Alzheimer Disease/genetics , Amyotrophic Lateral Sclerosis/genetics , Carrier Proteins/genetics , Cell Cycle Proteins/genetics , Ubiquitins/genetics , Adaptor Proteins, Signal Transducing , Alzheimer Disease/physiopathology , Amyotrophic Lateral Sclerosis/physiopathology , Animals , Autophagy-Related Proteins , Drosophila Proteins , Drosophila melanogaster/genetics , Drosophila melanogaster/physiology , Gene Knockdown Techniques , Humans , Learning/physiology , Locomotion/genetics , Locomotion/physiology , Mutation , Proteasome Endopeptidase Complex/genetics , Proteostasis/genetics , Ubiquitination/genetics
20.
Sci Rep ; 7(1): 15660, 2017 Nov 15.
Article in English | MEDLINE | ID: mdl-29142303

ABSTRACT

FUS is an aggregation-prone hnRNP involved in transcriptional and post-transcriptional regulation that aberrantly forms immunoreactive inclusion bodies in a range of neurological diseases classified as FUS-proteinopathies. Although FUS has been extensively examined, the underlying molecular mechanisms of these diseases have not yet been elucidated in detail. We previously reported that RNAi of the lncRNA hsrω altered the expression and sub-cellular localization of Drosophila FUS in the central nervous system of the fly. In order to obtain a clearer understanding of the role of hsrω in FUS toxicity, we herein drove the expression of human FUS in Drosophila eyes with and without a hsrω RNAi background. We found that hFUS was largely soluble and also able to form aggregates. As such, hFUS was toxic, inducing an aberrant eye morphology with the loss of pigmentation. The co-expression of hsrω double-stranded RNA reduced hFUS transcript levels and induced the formation of cytoplasmic non-toxic hFUS-LAMP1-insoluble inclusions. The combination of these events caused the titration of hFUS molar excess and a removal of hFUS aggregates to rescue toxicity. These results revealed the presence of a lncRNA-dependent pathway involved in the management of aggregation-prone hnRNPs, suggesting that properly formed FUS inclusions are not toxic to cells.


Subject(s)
Pigmentation/genetics , Protein Aggregates/genetics , RNA, Long Noncoding/genetics , RNA-Binding Protein FUS/genetics , Animals , Animals, Genetically Modified/genetics , Animals, Genetically Modified/growth & development , Central Nervous System/growth & development , Central Nervous System/metabolism , Drosophila melanogaster/genetics , Eye/growth & development , Eye/metabolism , Gene Expression Regulation/genetics , Heterogeneous-Nuclear Ribonucleoproteins/genetics , Lysosomal-Associated Membrane Protein 1/genetics , RNA, Double-Stranded/genetics
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