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1.
Mol Neurobiol ; 60(8): 4811-4827, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37171575

ABSTRACT

We have previously shown that histone deacetylase (HDAC) inhibition and cranial radiotherapy (RT) independently improve molecular and behavioral Alzheimer's disease (AD)-like phenotypes. In the present study, we investigate the synergistic potential of using both RT and HDACi as a low-dose combination therapy (LDCT) to maximize disease modification (reduce neuroinflammation and amyloidogenic APP processing, increase neurotrophic gene expression) while minimizing the potential for treatment-associated side effects.LDCT consisted of daily administration of the HDAC3 inhibitor RGFP966 and/or bi-weekly cranial x-irradiation. Amyloid-beta precursor protein (APP) processing and innate immune response to LDCT were assessed in vitro and in vivo using human and murine cell models and 3xTg-AD mice. After 2 months of LDCT in mice, behavioral analyses as well as expression and modification of key AD-related targets (Aß, tau, Csf1r, Bdnf, etc.) were assessed in the hippocampus (HIP) and prefrontal cortex (PFC).LDCT induced a tolerant, anti-inflammatory innate immune response in microglia and increased non-amyloidogenic APP processing in vitro. Both RT and LDCT improved the rate of learning and spatial memory in the Barnes maze test. LDCT induced a unique anti-AD HIP gene expression profile that included upregulation of neurotrophic genes and downregulation of inflammation-related genes. RT lowered HIP Aß42/40 ratio and Bace1 protein, while LDCT lowered PFC p-tau181 and HIP Bace1 levels.Our study supports the rationale for combining complementary therapeutic approaches at low doses to target multifactorial AD pathology synergistically. Namely, LDCT with RGFP966 and cranial RT shows disease-modifying potential against a wide range of AD-related hallmarks.


Subject(s)
Alzheimer Disease , Mice , Humans , Animals , Alzheimer Disease/metabolism , Amyloid Precursor Protein Secretases/metabolism , Amyloid beta-Peptides/metabolism , Mice, Transgenic , Aspartic Acid Endopeptidases/metabolism , Amyloid beta-Protein Precursor/genetics , Amyloid beta-Protein Precursor/metabolism , Maze Learning , Disease Models, Animal
3.
J Alzheimers Dis ; 86(1): 173-190, 2022.
Article in English | MEDLINE | ID: mdl-35034905

ABSTRACT

BACKGROUND: Alzheimer's disease (AD) has minimally effective treatments currently. High concentrations of resveratrol, a polyphenol antioxidant found in plants, have been reported to affect several AD-related and neuroprotective genes. To address the low bioavailability of resveratrol, we investigated a novel oral formulation of resveratrol, JOTROL™, that has shown increased pharmacokinetic properties compared to non-formulated resveratrol in animals and in humans. OBJECTIVE: We hypothesized that equivalent doses of JOTROL, compared to non-formulated resveratrol, would result in greater brain exposure to resveratrol, and more efficacious responses on AD biomarkers. METHODS: For sub-chronic reversal studies, 15-month-old male triple transgenic (APPSW/PS1M146V/TauP301L; 3xTg-AD) AD mice were treated orally with vehicle or 50 mg/kg JOTROL for 36 days. For prophylactic studies, male and female 3xTg-AD mice were similarly administered vehicle, 50 mg/kg JOTROL, or 50 mg/kg resveratrol for 9 months starting at 4 months of age. A behavioral battery was run, and mRNA and protein from brain and blood were analyzed for changes in AD-related gene and protein expression. RESULTS: JOTROL displays significantly increased bioavailability over non-formulated resveratrol. Treatment with JOTROL resulted in AD-related gene expression changes (Adam10, Bace1, Bdnf, Psen1) some of which were brain region-dependent and sex-specific, as well as changes in inflammatory gene and cytokine levels. CONCLUSION: JOTROL may be effective as a prophylaxis and/or treatment for AD through increased expression and/or activation of neuroprotective genes, suppression of pro-inflammatory genes, and regulation of central and peripheral cytokine levels.


Subject(s)
Alzheimer Disease , Alzheimer Disease/drug therapy , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Amyloid Precursor Protein Secretases , Animals , Aspartic Acid Endopeptidases , Cytokines/genetics , Disease Models, Animal , Female , Humans , Male , Mice , Mice, Transgenic , Resveratrol , tau Proteins/metabolism
4.
Heliyon ; 7(7): e07570, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34377851

ABSTRACT

Brain-derived neurotrophic factor (Bdnf) expression is tightly controlled at the transcriptional and post-transcriptional levels. Previously, we showed that inhibition of noncoding Bdnf antisense (Bdnf-AS) RNA upregulates Bdnf protein. Here, we generated a Bdnf-antisense knockout (Bdnf-AS KO) mouse model by deleting 6 kilobases upstream of Bdnf-AS. After verifying suppression of Bdnf-AS, baseline behavioral tests indicated no significant difference in knockout and wild type mice, except for enhanced cognitive function in the knockout mice in the Y-maze. Following acute involuntary exercise, Bdnf-AS KO mice were re-assessed and a significant increase in Bdnf mRNA and protein were observed. Following long-term involuntary exercise, we observed a significant increase in nonspatial and spatial memory in novel object recognition and Barnes maze tests in young and aged Bdnf-AS KO mice. Our data provides evidence for the beneficial effects of endogenous Bdnf upregulation and the synergistic effect of Bdnf-AS knockout on exercise and memory retention.

5.
Sci Rep ; 11(1): 3455, 2021 02 10.
Article in English | MEDLINE | ID: mdl-33568776

ABSTRACT

The Nucleocapsid Protein (N Protein) of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV2) is located in the viral core. Immunoglobulin G (IgG) targeting N protein is detectable in the serum of infected patients. The effect of high titers of IgG against N-protein on clinical outcomes of SARS-CoV2 disease has not been described. We studied 400 RT-PCR confirmed SARS-CoV2 patients to determine independent factors associated with poor outcomes, including Medical Intensive Care Unit (MICU) admission, prolonged MICU stay and hospital admissions, and in-hospital mortality. We also measured serum IgG against the N protein and correlated its concentrations with clinical outcomes. We found that several factors, including Charlson comorbidity Index (CCI), high levels of IL6, and presentation with dyspnea were associated with poor clinical outcomes. It was shown that higher CCI and higher IL6 levels were independently associated with in-hospital mortality. Anti-N protein IgG was detected in the serum of 55 (55%) patients at the time of admission. A high concentration of antibodies, defined as signal to cut off ratio (S/Co) > 1.5 (75 percentile of all measurements), was found in 25 (25%) patients. The multivariable logistic regression models showed that between being an African American, higher CCI, lymphocyte counts, and S/Co ratio > 1.5, only S/Co ratio were independently associated with MICU admission and longer length of stay in hospital. This study recommends that titers of IgG targeting N-protein of SARS-CoV2 at admission is a prognostic factor for the clinical course of disease and should be measured in all patients with SARS-CoV2 infection.


Subject(s)
COVID-19/immunology , Immunoglobulin G/immunology , Nucleocapsid Proteins/immunology , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , Female , Humans , Immunoglobulin G/blood , Intensive Care Units , Length of Stay , Male , Middle Aged , Prognosis , Spike Glycoprotein, Coronavirus/immunology
7.
Am J Hum Genet ; 104(4): 767-773, 2019 04 04.
Article in English | MEDLINE | ID: mdl-30929741

ABSTRACT

The diagnostic gap for rare neurodegenerative diseases is still considerable, despite continuous advances in gene identification. Many novel Mendelian genes have only been identified in a few families worldwide. Here we report the identification of an autosomal-dominant gene for hereditary spastic paraplegia (HSP) in 10 families that are of diverse geographic origin and whose affected members all carry unique truncating changes in a circumscript region of UBAP1 (ubiquitin-associated protein 1). HSP is a neurodegenerative disease characterized by progressive lower-limb spasticity and weakness, as well as frequent bladder dysfunction. At least 40% of affected persons are currently undiagnosed after exome sequencing. We identified pathological truncating variants in UBAP1 in affected persons from Iran, USA, Germany, Canada, Spain, and Bulgarian Roma. The genetic support ranges from linkage in the largest family (LOD = 8.3) to three confirmed de novo mutations. We show that mRNA in the fibroblasts of affected individuals escapes nonsense-mediated decay and thus leads to the expression of truncated proteins; in addition, concentrations of the full-length protein are reduced in comparison to those in controls. This suggests either a dominant-negative effect or haploinsufficiency. UBAP1 links endosomal trafficking to the ubiquitination machinery pathways that have been previously implicated in HSPs, and UBAP1 provides a bridge toward a more unified pathophysiology.


Subject(s)
Carrier Proteins/genetics , Mutation , Spastic Paraplegia, Hereditary/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Child , Child, Preschool , Databases, Factual , Disease Models, Animal , Endosomes/metabolism , Family Health , Female , Fibroblasts/metabolism , Genes, Dominant , Genetic Linkage , Genetic Predisposition to Disease , Genomics , HEK293 Cells , Haploinsufficiency , Humans , Male , Middle Aged , Pedigree , Protein Isoforms , Young Adult , Zebrafish
8.
BMC Med Genet ; 19(1): 86, 2018 05 25.
Article in English | MEDLINE | ID: mdl-29801479

ABSTRACT

BACKGROUND: Osteogenesis imperfecta (OI) is a group of connective tissue disorder caused by mutations of genes involved in the production of collagen and its supporting proteins. Although the majority of reported OI variants are in COL1A1 and COL1A2 genes, recent reports have shown problems in other non-collagenous genes involved in the post translational modifications, folding and transport, transcription and proliferation of osteoblasts, bone mineralization, and cell signaling. Up to now, 17 types of OI have been reported in which types I to IV are the most frequent cases with autosomal dominant pattern of inheritance. CASE PRESENTATION: Here we report an 8- year- old boy with OI who has had multiple fractures since birth and now he is wheelchair-dependent. To identify genetic cause of OI in our patient, whole exome sequencing (WES) was carried out and it revealed a novel deleterious homozygote splice acceptor site mutation (c.1257-2A > G, IVS7-2A > G) in FKBP10 gene in the patient. Then, the identified mutation was confirmed using Sanger sequencing in the proband as homozygous and in his parents as heterozygous, indicating its autosomal recessive pattern of inheritance. In addition, we performed RT-PCR on RNA transcripts originated from skin fibroblast of the proband to analyze the functional effect of the mutation on splicing pattern of FKBP10 gene and it showed skipping of the exon 8 of this gene. Moreover, Real-Time PCR was carried out to quantify the expression level of FKBP10 in the proband and his family members in which it revealed nearly the full decrease in the level of FKBP10 expression in the proband and around 75% decrease in its level in the carriers of the mutation, strongly suggesting the pathogenicity of the mutation. CONCLUSIONS: Our study identified, for the first time, a private pathogenic splice site mutation in FKBP10 gene and further prove the involvement of this gene in the rare cases of autosomal recessive OI type XI with distinguished clinical manifestations.


Subject(s)
Exome Sequencing/methods , Mutation , Osteogenesis Imperfecta/genetics , RNA Splice Sites , Tacrolimus Binding Proteins/genetics , Child , Down-Regulation , Female , Heterozygote , Humans , Male , Pedigree
9.
Asian J Psychiatr ; 38: 92-95, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29158148

ABSTRACT

BACKGROUND: Escitalopram has some unique features among selective serotonin reuptake inhibitors. The aim of this survey is to compare the efficacy of escitalopram with sertraline on obsessive and compulsive symptoms in patients with Obsessive Compulsive Disorder (OCD). METHODS: In this 12-week double blind controlled randomized clinical trial, 57 patients with OCD were randomly allocated to receive escitalopram or sertraline. Yale Brown obsessive compulsive behavior scale (YBOCS) was used to assess the outcomes. Adverse effects were also recorded. RESULTS: 41 patients (20 in the escitalopram group and 21 in the sertraline group) completed the trial. In the escitalopram group 15 (70%) patients and in the sertraline group 16 (76.19%) patients showed more than 34% decrease in mean YBOCS score at the end of the trial (P=0.531). The two groups revealed significant decrease in YBOCS scores without significant difference (P=0.861) at week 12. No serious adverse effects were reported. CONCLUSIONS: Our results demonstrated that escitalopram is as effective as sertraline in treatment of obsessions and compulsions in patients with OCD. However, it needs to be noted that our study is preliminary and larger double blind controlled studies are needed to confirm the results.


Subject(s)
Citalopram/pharmacology , Obsessive-Compulsive Disorder/drug therapy , Obsessive-Compulsive Disorder/physiopathology , Outcome Assessment, Health Care , Selective Serotonin Reuptake Inhibitors/pharmacology , Sertraline/pharmacology , Adult , Double-Blind Method , Female , Humans , Male , Young Adult
10.
BMC Med Genet ; 18(1): 73, 2017 07 17.
Article in English | MEDLINE | ID: mdl-28716012

ABSTRACT

BACKGROUND: Type II or juvenile GM1-gangliosidosis is an autosomal recessive lysosomal storage disorder, which is clinically distinct from infantile form of the disease by the lack of characteristic cherry-red spot and hepatosplenomegaly. The disease is characterized by slowly progressive neurodegeneration and mild skeletal changes. Due to the later age of onset and uncharacteristic presentation, diagnosis is frequently puzzled with other ataxic and purely neurological disorders. Up to now, 3-4 types of GM1-gangliosidosis have been reported and among them type I is the most common phenotype with the age of onset around 6 months. Various forms of GM1-gangliosidosis are caused by GLB1 gene mutations but severity of the disease and age of onset are directly related to the position and the nature of deleterious mutations. However, due to its unique genetic cause and overlapping clinical features, some researchers believe that GM1 gangliosidosis represents an overlapped disease spectrum instead of four distinct types. CASE PRESENTATION: Here, we report a less frequent type of autosomal recessive GM1 gangliosidosis with perplexing clinical presentation in three families in the southwest part of Iran, who are unrelated but all from "Lurs" ethnic background. To identify disease-causing mutations, Whole Exome Sequencing (WES) utilizing next generation sequencing was performed. Four patients from three families were investigated with the age of onset around 3 years old. Clinical presentations were ataxia, gate disturbances and dystonia leading to wheelchair-dependent disability, regression of intellectual abilities, and general developmental regression. They all were born in consanguineous families with no previous documented similar disease in their parents. A homozygote missense mutation in GLB1 gene (c. 601 G > A, p.R201C) was found in all patients. Using Sanger sequencing this identified mutation was confirmed in the proband, their parents, grandparents, and extended family members, confirming its autosomal recessive pattern of inheritance. CONCLUSIONS: Our study identified a rare pathogenic missense mutation in GLB1 gene in patients with complex neurodevelopmental findings, which can extend the list of differential diagnoses for childhood ataxia in Iranian patients.


Subject(s)
Gangliosidosis, GM1/genetics , Mutation, Missense , beta-Galactosidase/genetics , Child , Child, Preschool , Consanguinity , Female , Humans , Male
11.
BMC Med Genet ; 18(1): 49, 2017 05 03.
Article in English | MEDLINE | ID: mdl-28468610

ABSTRACT

BACKGROUND: Hemophagocytic Lymphohistiocytosis (HLH) is a life-threatening immunodeficiency and multi-organ disease that affects people of all ages and ethnic groups. Common symptoms and signs of this disease are high fever, hepatosplenomegaly, and cytopenias. Familial form of HLH disease, which is an autosomal recessive hematological disorder is due to disease-causing mutations in several genes essential for NK and T-cell granule-mediated cytotoxic function. For an effective cytotoxic response from cytotoxic T lymphocyte or NK cell encountering an infected cell or tumor cell, different processes are required, including trafficking, docking, priming, membrane fusion, and entry of cytotoxic granules into the target cell leading to apoptosis. Therefore, genes involved in these steps play important roles in the pathogenesis of HLH disease which include PRF1, UNC13D (MUNC13-4), STX11, and STXBP2 (MUNC18-2). CASE PRESENTATION: Here, we report a novel missense mutation in an 8-year-old boy suffered from hepatosplenomegaly, hepatitis, epilepsy and pancytopenia. The patient was born to a first-cousin parents with no previous documented disease in his parents. To identify mutated gene in the proband, Whole Exome Sequencing (WES) utilizing next generation sequencing was used on an Illumina HiSeq 2000 platform on DNA sample from the patient. Results showed a novel deleterious homozygous missense mutation in PRF1 gene (NM_001083116: exon3: c. 1120 T > G, p.W374G) in the patient and then using Sanger sequencing it was confirmed in the proband and his parents. Since his parents were heterozygous for the identified mutation, autosomal recessive pattern of inheritance was confirmed in the family. CONCLUSIONS: Our study identified a rare new pathogenic missense mutation in PRF1 gene in patient with HLH disease and it is the first report of mutation in PRF1 in Iranian patients with this disease.


Subject(s)
Genes, Recessive , Lymphohistiocytosis, Hemophagocytic/genetics , Mutation, Missense , Perforin/genetics , Child , Female , Humans , Lymphohistiocytosis, Hemophagocytic/diagnostic imaging , Magnetic Resonance Imaging , Male , Pedigree
12.
J Biomol Screen ; 20(9): 1132-41, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26173710

ABSTRACT

Long non-protein coding RNAs (lncRNAs) are an important class of molecules that help orchestrate key cellular events. Although their functional roles in cells are not well understood, thousands of lncRNAs and a number of possible mechanisms by which they act have been reported. LncRNAs can exert their regulatory function in cells by interacting with epigenetic enzymes. In this study, we developed a tool to study lncRNA-protein interactions for high-throughput screening of small-molecule modulators using AlphaScreen technology. We tested the interaction of two lncRNAs: brain-derived neurotrophic factor antisense (BDNF-AS) and Hox transcript antisense RNA (HOTAIR), with Enhancer of zeste homolog 2 (EZH2), a histone methyltransferase against a phytochemical library, to look for small-molecule inhibitors that can alter the expression of downstream target genes. We identified ellipticine, a compound that up-regulates BDNF transcription. Our study shows the feasibility of using high-throughput screening to identify modulators of lncRNA-protein interactions and paves the road for targeting lncRNAs that are dysregulated in human disorders using small-molecule therapies.


Subject(s)
High-Throughput Screening Assays , RNA, Long Noncoding/antagonists & inhibitors , Brain-Derived Neurotrophic Factor/biosynthesis , Brain-Derived Neurotrophic Factor/genetics , Drug Evaluation, Preclinical , Ellipticines/pharmacology , Enhancer of Zeste Homolog 2 Protein , Gene Expression/drug effects , HEK293 Cells , Humans , Polycomb Repressive Complex 2/biosynthesis , Polycomb Repressive Complex 2/genetics , Protein Binding/drug effects , RNA Interference/drug effects , RNA, Long Noncoding/biosynthesis , RNA, Long Noncoding/chemistry
13.
Nat Biotechnol ; 30(5): 453-9, 2012 Mar 25.
Article in English | MEDLINE | ID: mdl-22446693

ABSTRACT

The ability to specifically upregulate genes in vivo holds great therapeutic promise. Here we show that inhibition or degradation of natural antisense transcripts (NATs) by single-stranded oligonucleotides or siRNAs can transiently and reversibly upregulate locus-specific gene expression. Brain-derived neurotrophic factor (BDNF) is normally repressed by a conserved noncoding antisense RNA transcript, BDNF-AS. Inhibition of this transcript upregulates BDNF mRNA by two- to sevenfold, alters chromatin marks at the BDNF locus, leads to increased protein levels and induces neuronal outgrowth and differentiation both in vitro and in vivo. We also show that inhibition of NATs leads to increases in glial-derived neurotrophic factor (GDNF) and ephrin receptor B2 (EPHB2) mRNA. Our data suggest that pharmacological approaches targeting NATs can confer locus-specific gene upregulation effects.


Subject(s)
Oligonucleotides, Antisense/antagonists & inhibitors , Up-Regulation , Animals , Cell Line , Chromatin/chemistry , Chromatin/metabolism , Exons , Gene Expression Profiling , Genomics , Glial Cell Line-Derived Neurotrophic Factor/biosynthesis , HEK293 Cells , Humans , Mice , Models, Genetic , RNA, Messenger/metabolism , RNA, Small Interfering/metabolism , Receptor, EphB2/biosynthesis , Sequence Analysis, DNA , Transcription, Genetic
14.
Int J Alzheimers Dis ; 2011: 929042, 2011.
Article in English | MEDLINE | ID: mdl-21785702

ABSTRACT

Background. Alzheimer's disease (AD) is a devastating neurological disorder and the main cause of dementia in the elderly population worldwide. Adult neurogenesis appears to be upregulated very early in AD pathogenesis in response to some specific aggregates of beta-amyloid (Aß) peptides, exhausting the neuronal stem cell pools in the brain. Previously, we characterized a conserved nonprotein-coding antisense transcript for ß-secretase-1 (BACE1), a critical enzyme in AD pathophysiology. We showed that the BACE1-antisense transcript (BACE1-AS) is markedly upregulated in brain samples from AD patients and promotes the stability of the (sense) BACE1 transcript. In the current paper, we examine the relationship between BACE1, BACE1-AS, adult neurogenesis markers, and amyloid plaque formation in amyloid precursor protein (APP) transgenic mice (Tg-19959) of various ages. Results. Consistent with previous publications in other APP overexpressing mouse models, we found adult neurogenesis markers to be noticeably upregulated in Tg-19959 mice very early in the development of the disease. Knockdown of either one of BACE1 or BACE1-AS transcripts by continuous infusion of locked nucleic acid- (LNA-) modified siRNAs into the third ventricle over the period of two weeks caused concordant downregulation of both transcripts in Tg-19959 mice. Downregulation of BACE1 mRNA was followed by reduction of BACE1 protein and insoluble Aß. Modulation of BACE1 and BACE1-AS transcripts also altered oligomeric Aß aggregation pattern, which was in turn associated with an increase in neurogenesis markers at the RNA and protein level. Conclusion. We found alterations in the RNA and protein concentrations of several adult neurogenesis markers, as well as non-protein-coding BACE1-AS transcripts, in parallel with the course of ß-amyloid synthesis and aggregation in the brain of Tg15999 mice. In addition, by knocking down BACE1 or BACE1-AS (thereby reducing Aß production and plaque deposition), we were able to modulate expression of these neurogenesis markers. Our findings suggest a distortion of adult neurogenesis that is associated with Aß production very early in amyloid pathogenesis. We believe that these alterations, at the molecular level, could prove useful as novel therapeutic targets and/or as early biomarkers of AD.

15.
PLoS One ; 5(10)2010 Oct 04.
Article in English | MEDLINE | ID: mdl-20957177

ABSTRACT

Natural antisense transcripts represent a class of regulatory RNA molecules, which are characterized by their complementary sequence to another RNA transcript. Extensive sequencing efforts suggest that natural antisense transcripts are prevalent throughout the mammalian genome; however, their biological significance has not been well defined. We performed a loss-of-function RNA interference (RNAi) screen, which targeted 797 evolutionary conserved antisense transcripts, and found evidence for a regulatory role for a number of natural antisense transcripts. Specifically, we found that natural antisense transcripts for CCPG1 and RAPGEF3 may functionally disrupt signaling pathways and corresponding biological phenotypes, such as cell viability, either independently or in parallel with the corresponding sense transcript. Our results show that the large-scale siRNA screen can be applied to evaluate natural antisense transcript modulation of fundamental cellular events.


Subject(s)
RNA Interference , RNA, Antisense/genetics , RNA, Messenger/genetics , Cell Line , Cell Proliferation , Gene Knockdown Techniques , Humans , Oligonucleotide Array Sequence Analysis
16.
Genome Biol ; 11(5): R56, 2010.
Article in English | MEDLINE | ID: mdl-20507594

ABSTRACT

BACKGROUND: MicroRNAs (miRNAs) have the potential to regulate diverse sets of mRNA targets. In addition, mammalian genomes contain numerous natural antisense transcripts, most of which appear to be non-protein-coding RNAs (ncRNAs). We have recently identified and characterized a highly conserved non-coding antisense transcript for beta-secretase-1 (BACE1), a critical enzyme in Alzheimer's disease pathophysiology. The BACE1-antisense transcript is markedly up-regulated in brain samples from Alzheimer's disease patients and promotes the stability of the (sense) BACE1 transcript. RESULTS: We report here that BACE1-antisense prevents miRNA-induced repression of BACE1 mRNA by masking the binding site for miR-485-5p. Indeed, miR-485-5p and BACE1-antisense compete for binding within the same region in the open reading frame of the BACE1 mRNA. We observed opposing effects of BACE1-antisense and miR-485-5p on BACE1 protein in vitro and showed that Locked Nucleic Acid-antimiR mediated knockdown of miR-485-5p as well as BACE1-antisense over-expression can prevent the miRNA-induced BACE1 suppression. We found that the expression of BACE1-antisense as well as miR-485-5p are dysregulated in RNA samples from Alzheimer's disease subjects compared to control individuals. CONCLUSIONS: Our data demonstrate an interface between two distinct groups of regulatory RNAs in the computation of BACE1 gene expression. Moreover, bioinformatics analyses revealed a theoretical basis for many other potential interactions between natural antisense transcripts and miRNAs at the binding sites of the latter.


Subject(s)
MicroRNAs/metabolism , RNA, Antisense/metabolism , Aged , Aged, 80 and over , Alzheimer Disease/enzymology , Alzheimer Disease/genetics , Amyloid Precursor Protein Secretases/genetics , Amyloid Precursor Protein Secretases/metabolism , Animals , Aspartic Acid Endopeptidases/genetics , Aspartic Acid Endopeptidases/metabolism , Base Sequence , Binding Sites , Binding, Competitive/drug effects , Brain/drug effects , Brain/enzymology , Brain/pathology , Cell Line , High-Throughput Screening Assays , Humans , Luciferases/metabolism , Mice , MicroRNAs/genetics , Molecular Sequence Data , Oligonucleotides/pharmacology , Open Reading Frames/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Untranslated/genetics , RNA, Untranslated/metabolism , Reproducibility of Results , Sequence Analysis, DNA
17.
Nat Med ; 14(7): 723-30, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18587408

ABSTRACT

Recent efforts have revealed that numerous protein-coding messenger RNAs have natural antisense transcript partners, most of which seem to be noncoding RNAs. Here we identify a conserved noncoding antisense transcript for beta-secretase-1 (BACE1), a crucial enzyme in Alzheimer's disease pathophysiology. The BACE1-antisense transcript (BACE1-AS) regulates BACE1 mRNA and subsequently BACE1 protein expression in vitro and in vivo. Upon exposure to various cell stressors including amyloid-beta 1-42 (Abeta 1-42), expression of BACE1-AS becomes elevated, increasing BACE1 mRNA stability and generating additional Abeta 1-42 through a post-transcriptional feed-forward mechanism. BACE1-AS concentrations were elevated in subjects with Alzheimer's disease and in amyloid precursor protein transgenic mice. These data show that BACE1 mRNA expression is under the control of a regulatory noncoding RNA that may drive Alzheimer's disease-associated pathophysiology. In summary, we report that a long noncoding RNA is directly implicated in the increased abundance of Abeta 1-42 in Alzheimer's disease.


Subject(s)
Alzheimer Disease/etiology , Alzheimer Disease/metabolism , Amyloid Precursor Protein Secretases/metabolism , Aspartic Acid Endopeptidases/metabolism , RNA, Untranslated/metabolism , Aged , Aged, 80 and over , Alzheimer Disease/enzymology , Alzheimer Disease/physiopathology , Amyloid Precursor Protein Secretases/genetics , Amyloid beta-Peptides/metabolism , Animals , Aspartic Acid Endopeptidases/genetics , Cell Line, Tumor , Feedback, Physiological , Gene Expression Regulation , Humans , Male , Mice , Mice, Transgenic , Middle Aged , Models, Genetic , Neuroblastoma/pathology , Peptide Fragments/metabolism , Protein Processing, Post-Translational , RNA, Messenger/metabolism , RNA, Small Interfering/pharmacology , RNA, Untranslated/analysis , Transcription, Genetic , Transfection
18.
PLoS One ; 3(1): e1486, 2008 Jan 23.
Article in English | MEDLINE | ID: mdl-18213394

ABSTRACT

Several genome-wide transcriptomics efforts have shown that a large percentage of the mammalian genome is transcribed into RNAs, however, only a small percentage (1-2%) of these RNAs is translated into proteins. Currently there is an intense interest in characterizing the function of the different classes of noncoding RNAs and their relevance to human disease. Using genomic approaches we discovered FMR4, a primate-specific noncoding RNA transcript (2.4 kb) that resides upstream and likely shares a bidirectional promoter with FMR1. FMR4 is a product of RNA polymerase II and has a similar half-life to FMR1. The CGG expansion in the 5' UTR of FMR1 appears to affect transcription in both directions as we found FMR4, similar to FMR1, to be silenced in fragile X patients and up-regulated in premutation carriers. Knockdown of FMR4 by several siRNAs did not affect FMR1 expression, nor vice versa, suggesting that FMR4 is not a direct regulatory transcript for FMR1. However, FMR4 markedly affected human cell proliferation in vitro; siRNAs knockdown of FMR4 resulted in alterations in the cell cycle and increased apoptosis, while the overexpression of FMR4 caused an increase in cell proliferation. Collectively, our results demonstrate an antiapoptotic function of FMR4 and provide evidence that a well-studied genomic locus can show unexpected functional complexity. It cannot be excluded that altered FMR4 expression might contribute to aspects of the clinical presentation of fragile X syndrome and/or related disorders.


Subject(s)
Apoptosis/genetics , Fragile X Syndrome/genetics , Gene Silencing , RNA, Long Noncoding/genetics , RNA, Messenger/genetics , Animals , Base Sequence , Cell Cycle , Cell Line , Cell Proliferation , DNA Primers , Fragile X Mental Retardation Protein/genetics , Humans , In Situ Nick-End Labeling , Promoter Regions, Genetic , Protein Biosynthesis , RNA Polymerase II/metabolism , Transcription, Genetic
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