DOCSLIB.ORG

Circular HDAC9/Microrna-138/Sirtuin-1 Pathway Mediates Synaptic and Amyloid Precursor Protein Processing Deficits in Alzheimer’S Disease

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Circular HDAC9/Microrna-138/Sirtuin-1 Pathway Mediates Synaptic and Amyloid Precursor Protein Processing Deficits in Alzheimer’S Disease Neurosci. Bull. October, 2019, 35(5):877–888 www.neurosci.cn https://doi.org/10.1007/s12264-019-00361-0 www.springer.com/12264 ORIGINAL ARTICLE Circular HDAC9/microRNA-138/Sirtuin-1 Pathway Mediates Synaptic and Amyloid Precursor Protein Processing Deficits in Alzheimer’s Disease 1 2 1 Yanjun Lu • Lu Tan • Xiong Wang Received: 2 September 2018 / Accepted: 12 December 2018 / Published online: 18 March 2019 Ó Shanghai Institutes for Biological Sciences, CAS 2019 Abstract Synaptic dysfunction and abnormal processing circHDAC9 was decreased in the serum of both AD of amyloid precursor protein (APP) are early pathological patients and individuals with mild cognitive impairment. features in Alzheimer’s disease (AD). Recently, non- These results suggest that the circHDAC9/miR-138/Sirt1 coding RNAs such as microRNAs (miRNAs) and circular pathway mediates synaptic function and APP processing in RNAs (circRNAs) have been reported to contribute to the AD, providing a potential therapeutic target for its pathogenesis of AD. We found an age-dependent elevation treatment. of miR-138 in APP/PS1 (presenilin-1) mice. MiR-138 inhibited the expression of ADAM10 [a disintegrin and Keywords Alzheimer’s disease Á Synapse Á Memory Á metalloproteinase domain-containing protein 10], pro- Sirtuin-1 Á microRNA Á Circular RNA moted amyloid beta (Ab) production, and induced synaptic and learning/memory deficits in APP/PS1 mice, while its suppression alleviated the AD-like phenotype in these Introduction mice. Overexpression of sirtuin 1 (Sirt1), a target of miR- 138, ameliorated the miR-138-induced inhibition of Alzheimer’s disease (AD) is a neurodegenerative disorder ADAM10 and elevation of Ab in vitro. The circRNA that is the most frequent cause of dementia, accounting for HDAC9 (circHDAC9) was predicted to contain a miR-138 60%–80% of all cases with dementia. The prevalence of binding site in several databases. Its expression was AD is 10% in people aged 65 and over, and increases to inversely correlated with miR-138 in both Ab-oligomer- 32% in those aged 85 and over [1]. The symptoms include treated N2a cells and APP/PS1 mice, and it co-localized a gradually worsening ability to remember new informa- with miR-138 in the cytoplasm of N2a cells. CircHDAC9 tion in the initial stage and an inability to communicate in acted as a miR-138 sponge, decreasing miR-138 expres- the advanced stage. The mechanism underlying AD sion, and reversing the Sirt1 suppression and excessive Ab remains unclear [2]. production induced by miR-138 in vitro. Moreover, Accumulating evidence indicates that non-coding RNAs (ncRNAs) are involved in AD, including microRNAs (miRNAs), long ncRNAs, piwi-interacting RNAs, and Yanjun Lu and Lu Tan have contributed equally to this work. circular RNAs (circRNAs) [3–5]. MiRNAs suppress target mRNA translation or induce mRNA decay via binding with & Xiong Wang 0 [email protected] seed sequences in the 3 -untranslated region of the target mRNA. Numerous dysregulated miRNAs in AD contribute 1 Department of Laboratory Medicine, Tongji Hospital, Tongji to the processing of amyloid precursor protein (APP), tau Medical College, Huazhong University of Science and phosphorylation, and synaptic plasticity [6, 7]. Technology, Wuhan 430030, China CircRNAs are a group of RNAs with covalently closed 2 Key Laboratory for Molecular Diagnosis of Hubei Province, loop structures, generated during splicing. A number of The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, conserved circRNAs are highly enriched in the mammalian Wuhan 430014, China brain, some of which are derived from synaptic genes and 123 878 Neurosci. Bull. October, 2019, 35(5):877–888 regulated depending on the developmental stage [8, 9]. Ethics Committee of Tongji Hospital approved the study Natural circRNAs function as miRNA sponges in the brain, and informed consent was given. providing potential novel therapeutic targets for AD treatment [8, 10]. Materials MiR-138 is a conserved miRNA that is enriched in the brain. It is increased in the cerebrospinal fluid (CSF) of AD Anti-APP antibody was from Abcam (Cambridge, UK), patients [11], acts as a potential regulator of memory anti-ADAM10 from Abcam, anti-BACE1 from Cell Sig- performance in humans, and negatively regulates dendritic naling Technology (Danvers, MA, USA), anti-b-actin from spine morphogenesis [12, 13]. Our previous study demon- Cell Signaling Technology (Danvers, MA, USA), anti- strated that miR-138 is increased in 12-month-old Tg2576 GAPDH from Proteintech (Wuhan, China), anti-sAPPb mice, N2a/APP cells, and HEK293/tau cells. Furthermore, from IBL (Fujioka-Shi, Gunma, Japan); and anti-Sirt1 from miR-138 promotes tau phosphorylation by targeting Cell Signaling Technology (Danvers, MA) or Proteintech retinoic acid receptor alpha [7, 14]. (Wuhan, China). The Ab42 ELISA kit was from Elab- Therefore we set out to determine the role of science (Wuhan, China), FISH kit from Bersinbio circHDAC9/miR-138/Sirt1 pathway in the synaptic, learn- (Guangzhou, China), RevertAid First Strand cDNA Syn- ing/memory, and APP processing deficits in AD. thesis Kit from Takara (Kusatsu, Shiga, Japan), miRNA Purification Kit from Cwbiotech (Beijing, China), RIPA lysis buffer from Beyotime (Shanghai, China), and HRP- Materials and Methods conjugated secondary antibody from Santa Cruz (Santa Cruz, CA, USA). The miR-138 mimic and agomir/an- Transgenic AD Mice tagomir and the scrambled control were from RiboBio (Guangzhou, China) and the miR-138-overexpressing con- Male APP/PS1 (APPswe and PSEN1dE9) transgenic mice struct was from GeneCopoeia (San Diego, CA, USA). The and control littermates were purchased from the Animal Sirt1 and APP plasmids were kindly gifted by Prof. Jianzhi Model Research Center of Nanjing University (Nanjing, Wang (Tongji Medical College, Huazhong University of Jiangsu, China). This work was approved by the Animal Science and Technology). The miR-138 mimic was from Care and Use Committee of Tongji Hospital, Tongji RiboBio (Guangzhou, China). Medical College of Huazhong University of Science and Technology. Stereotaxic Microinfusion Human Blood Samples Mice were anesthetized with chloral hydrate (400 mg/kg, intraperitoneal). Holes were drilled above the CA3 field of Ten amnestic patients with mild cognitive impairment the hippocampus (anterior/posterior ± 1.9 mm, medial/ (MCI) (7 males, 3 females; 70.20 ± 10.40 years old) and lateral ± 1.9 mm, dorsal/ventral 2.1 mm). Agomir seven AD patients (5 males, 2 females; 70.43 ± 5.08 years (350 nmol/L, 1.5 lL) or antagomir (600 nmol/L, 1.5 lL) old) diagnosed as previously described [15], were recruited was bilaterally microinfused into the hippocampus. from Tongji Hospital. A diagnosis of MCI included: (1) memory complaint; (2) clinical dementia rating 0.5; and (3) Morris Water Maze Test normal general cognitive function and daily life activities. A diagnosis of AD included: (1) the NINCDS-ADRDA The Morris water maze (MWM) was a deep pool criteria (National Institute of Neurological and Commu- (diameter: 120 cm, deep: 80 cm) filled with water made nicative Disorders and Stroke-Alzheimer’s Disease and opaque with milk. The pool was divided into four Related Disorders Association); (2) Mini-Mental State quadrants with a platform submerged 1 cm beneath the Examination score B 26; and (3) exclusion of brain tumor, surface in the target quadrant. Mice were trained for 5 vascular dementia, and cerebrovascular diseases. Ten consecutive days to find the platform (n = 12/group). A healthy individuals (7 males, 3 females; digital tracking device was used to measure movement. On 64.40 ± 12.69 years old) were recruited as a control group day 7, the platform was removed, and the crossing time and for the MCI patients, and another seven (4 males, 3 distance in the target quadrant (%) were recorded. females; 70.86 ± 4.11 years old) as controls for the AD patients. No statistically significant differences in age were Golgi Staining found between the MCI/AD and corresponding control groups. Serum was collected for RNA extraction. The Mice were anesthetized with chloral hydrate (400 mg/kg, intraperitoneal). After perfusion with normal saline and 4% 123 Y. Lu et al.: CircHDAC9/mRNA-138/Sirtuin-1 Pathway Mediates Synaptic and APP Processing 879 formaldehyde, brain tissue was immersed in 5% potassium Statistics dichromate, 4% formaldehyde, and 5% silver nitrate for one month. Slices were then cut on a vibrating microtome Data are shown as mean ± SD and analyzed with SPSS (Leica, Wetzlar, Germany). version 16.0 (SPSS Inc., Chicago, IL). The difference between two groups was analyzed with unpaired Student’s Fluorescence In situ Hybridization (FISH) t-test (two-tailed). The variance among multiple groups was analyzed with one-/two-way analysis of variance with/ The probes for circHDAC9 (green) and miR-138 (red) without repeated measures followed by the Bonferroni post were from Bersinbio (Guangzhou, China). N2a cells were hoc test. All experiments were performed three times, and harvested and fixed in 4% formaldehyde. The denatured P \ 0.05 was considered statistically significant. probes were hybridized with N2a cells for 20 h at 42 °C. Nuclei were stained with DAPI. The slices were observed under a fluorescence microscope (LSM800, Carl Zeiss, Results Darmstadt, Germany). Age-Dependent Elevation of miR-138 in APP/PS1 Real-Time Quantitative PCR Mice RNA was extracted with TRIzol reagent and reverse- The expression of miR-138 in the hippocampus of APP/ transcribed into cDNA. MiRNAs were isolated with a PS1 and control mice was assessed in 2-, 4-, and 5-month- miRNA purification kit. Real-time quantitative PCR was old mice. No difference in expression was found in performed with a SYBR Premix Dimer Eraser kit. Mouse 2-month-old APP/PS1 mice, while the miR-138 level circHDAC9: F, AGCAGTTCCTGGAGAAGCAG, R, GC increased to 1.6-fold in in the hippocampus of 4-month-old ATCTGTGTCTCGCACTTC; mouse ciRS7: F, ATGTTG and 2.4-fold in 5-month-old APP/PS1 mice relative to the GAAGACCTTGGTACTGGC, R, CCAACATCTCCACA control group (Fig.
Load more

Recommended publications
  • In Vitro Studies of Self-Splicing Group II Introns
    Order Number 8913650 In vitro studies of self-splicing group II introns Hebbar, Sharda Kattingeri, Ph.D. The Ohio State University, 1989 Copyright ©1989 by Hebbar, Sharda Kattingeri. All rights reserved. U-M-I 300N.ZecbRd. Ann Arbor, MI 48106 IN VITRO STUDIES OF SELF-SPLICING GROUP II INTRONS DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University By Sharda Kattingeri Hebbar, B.S., M.S. ***** The Ohio State University 1989 Dissertation Committee: Approved by P. A. Fuerst L. F. Johnson — A. M. Lambowitz * Adviser P. S. Perlman Department of Molecular Genetics Copyright by Sharda Kattingeri Hebbar 1989 To My Parents, and To My Husband, Raja. ACKNOWLEDGEMENTS I would like to thank Dr. P.S. Perlman for his assistance and guidance. Special thanks go to Kevin Jarrell and Rosemary Dietrich not only for their technical advice but also for their friendship. To my husband, Raja, I would like to express my sincere gratitude for his encouragement, support and endurance throughout my endeavors. iii VITA February 21, 1960 ............. Born - Andhra Pradesh, India 1980 ................... B«S., Osnania University, Hyderabad, India 1980 - 1982 ................... M.S., Andhra University, Waltair, Andhra Pradesh 1983 - 1986 .................... Graduate Teaching Associate, MCDB Program, The Ohio State University, Columbus, Ohio 1986 - 1988 ................. Graduate Research Associate, Department of Molecular Genetics, The Ohio Sta+e University, Columbus, Ohio FIELDS OF STUDY Major Field: Molecular Genetics TABLE OF CONTENTS INTRODUCTION ................................................. 1 I.A. Catalytic RNA .......................... ......... 1 I.B. Yeast mitochondrial DNA ............................... 2 I.B.l. Mosaic genes 2 I.B.2.
    [Show full text]
  • Circular Rnas: a Rising Star in Respiratory Diseases Jian Wang1†, Mengchan Zhu1,2†, Jue Pan2, Cuicui Chen1, Shijin Xia3* and Yuanlin Song1*
    Wang et al. Respiratory Research (2019) 20:3 https://doi.org/10.1186/s12931-018-0962-1 REVIEW Open Access Circular RNAs: a rising star in respiratory diseases Jian Wang1†, Mengchan Zhu1,2†, Jue Pan2, Cuicui Chen1, Shijin Xia3* and Yuanlin Song1* Abstract Circular RNAs (CircRNAs), as a new class of non-coding RNA molecules that, unlike linear RNAs, have covalently closed loop structures from the ligation of exons, introns, or both. CircRNAs are widely expressed in various organisms in a specie-, tissue-, disease- and developmental stage-specific manner, and have been demonstrated to play a vital role in the pathogenesis and progression of human diseases. An increasing number of recent studies has revealed that circRNAs are intensively associated with different respiratory diseases, including lung cancer, acute respiratory distress syndrome, pulmonary hypertension, pulmonary tuberculosis, and silicosis. However, to the best of our knowledge, there has been no systematic review of studies on the role of circRNAs in respiratory diseases. In this review, we elaborate on the biogenesis, functions, and identification of circRNAs and focus particularly on the potential implications of circRNAs in respiratory diseases. Keywords: Circular RNAs, Non-coding RNA, miRNA sponge, Alternative splicing, Respiratory diseases Background [8–10]. Now, there is considerable interest in circRNAs In the early 1970s, Sanger et al. [1] detected the presence in the field of RNA research. of circRNAs in the plant viroid for the first time by Up until September 17, 2018, we identified 1370 records electro-microscopy. Soon after, similar circular RNAs about “circular RNA”, “circRNA” or “RNA, circular” in were found in yeast mitochondria and human hepatitis PubMed (https://www.ncbi.nlm.nih.gov/pubmed/).
    [Show full text]
  • Circapp Competes with APP Mrna to Promote Malignant Progression of Bladder Cancer
    CircAPP Competes with APP mRNA to Promote Malignant Progression of Bladder Cancer Minjun Qi Aliated No2 people's hospital of nanjing medical university Wei Cao Changzhou No 2 people's hospital Xingyu Wu changzhou no2 people's hospital Weijiang Mao changzhou no2 people's hospital Kai Cao wujin people's hospital Chao Lu changzhou no2 people's hospital xiaowu liu ( [email protected] ) wujin people's hospital https://orcid.org/0000-0003-4500-0023 Li Zuo Changzhou no2 people's hospital Primary research Keywords: bladder cancer, malignant progression, miRNA-186, circAPP Posted Date: April 12th, 2021 DOI: https://doi.org/10.21203/rs.3.rs-293144/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Page 1/19 Abstract Background: Bladder cancer (BCa) is the most common cancer in the urinary system with high recurrence rate and poor prognosis. Circular RNA (circRNA) is a novel subclass of noncoding-RNA which participate in progression of BCa. Here, we identied a novel circRNA—circAPP and aimed to investigate the role of circAPP in progression of BCa. Method: Public data of RNA sequencing was used to identify signicant circRNA related to BCa. The role of circRNAs in progression in BCa was assessed in cytotoxicity assay, transwell assay and ow cytometry. Biotin-coupled RNA pull-down and uorescence in situ hybridization (FISH) were performed to evaluate the interaction between circRNAs and miRNAs. Results: The expression of circAPP was higher in BCa tissues and cells than in normal samples. In vitro experiments showed that knockdown of circAPP inhibited cell proliferation and impeded the metastasis of BCa cells.
    [Show full text]
  • A Group Ill Twintron Encoding a Maturase-Like Gene Excises Through Lariat Intermediates
    I.=) 1994 Oxford University Press Nucleic Acids Research, 1994, Vol. 22, No. 6 1029-1036 A group Ill twintron encoding a maturase-like gene excises through lariat intermediates Donald W.Copertino1 2+, Edina T.Hall2,§, Fredrick W.Van Hook2, Kristin P.Jenkins2 and Richard B.Hallick1,2* 1Departments of Biochemistry and 2Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA Received December 9, 1993; Revised and Accepted February 10, 1994 ABSTRACT The 1605 bp intron 4 of the Euglena gracilis chloroplast the closely related nonphotosynthetic euglenoid Astasia longa psbC gene was characterized as a group Ill twintron (8, 9). composed of an internal 1503 nt group Ill intron with Euglena chloroplast genes also contain 15 twintrons, introns- an open reading frame of 1374 nt (ycfl3, 458 amino within-introns, that are sequentially spliced (3). There are acids), and an external group Ill intron of 102 nt. twintrons with one intron internal to another intron (2, 6, 10), Twintron excision proceeds by a sequential splicing and complex twintrons with multiple internal introns (11; for pathway. The splicing of the internal and external group review, see 3). Group II and group III introns can occur as Ill introns occurs via lariat intermediates. Branch sites internal and/or external introns of twintrons. Excision of internal were mapped by primer extension RNA sequencing. introns occurs prior to excision of external introns. The excision The unpaired adenosines in domains VI of the internal of internal group IH introns of twintrons can proceed from and external introns are covalently linked to the 5' multiple 5' and 3' splice sites (6, 1 1).
    [Show full text]
  • Novel Circular RNA Circnf1 Acts As a Molecular Sponge, Promoting Gastric Cancer by Absorbing Mir-16
    26 3 Endocrine-Related Z Wang et al. Mechanism of circNF1 in 26:3 265–277 Cancer gastric cancer RESEARCH Novel circular RNA circNF1 acts as a molecular sponge, promoting gastric cancer by absorbing miR-16 Zhe Wang1,2, Ke Ma2, Steffie Pitts3, Yulan Cheng2, Xi Liu4, Xiquan Ke5, Samuel Kovaka6, Hassan Ashktorab7, Duane T Smoot8, Michael Schatz6, Zhirong Wang1 and Stephen J Meltzer2 1Department of Gastroenterology, Tongji Hospital, Tongji University School of Medicine, Shanghai, China 2Division of Gastroenterology, Department of Medicine, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA 3Cellular and Molecular Medicine Graduate Program, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA 4Department of Pathology, The First Affiliated Hospital of Xi’ an Jiaotong University, Xi’ an, Shaanxi, China 5Department of Gastroenterology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China 6Department of Computer Science, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland, USA 7Cancer Center, Howard University School of Medicine, Washington, District of Columbia, USA 8Department of Medicine, Meharry Medical College, Nashville, Tennessee, USA Correspondence should be addressed to S J Meltzer: [email protected] Abstract Circular RNAs (circRNAs) are a new class of RNA involved in multiple human malignancies. Key Words However, limited information exists regarding the involvement of circRNAs in gastric f gastric carcinoma carcinoma (GC). Therefore, we sought to identify novel circRNAs, their functions and f circNF1 mechanisms in gastric carcinogenesis. We analyzed next-generation RNA sequencing f proliferation data from GC tissues and cell lines, identifying 75,201 candidate circRNAs. Among these, f miR-16 we focused on one novel circRNA, circNF1, which was upregulated in GC tissues and cell lines.
    [Show full text]
  • Synthesis of Circular RNA in Bacteria and Yeast Using RNA Cyclase
    Proc. Nati. Acad. Sci. USA Vol. 91, pp. 3117-3121, April 1994 Biochemistry Synthesis of circular RNA in bacteria and yeast using RNA cyclase ribozymes derived from a group I intron of phage T4 (spdng/RNA /Eschenclhi coli/Skecmmyces ceremisia/td gene) ETHAN FoRD* AND MANUEL ARES, JRJ Biology Department, Sinsheimer Laboratories, University of California, Santa Cruz, Santa Cruz, CA 95064 Communicated by Harry F. Noller, December 22, 1993 ABSTRACT Studies on the of circular RNA and introns (for example, see refs. 11-15) indicates that these RNA topology in vivo have been limited by the dffIculty in splicing machineries have no mechanism for enforcing the expressng circular RNA of desired sequence. To overcome requirement for proper splice site position within a transcript. this, the group I intron from the phage T4 d gene was split in Thus, group I and group II transcripts in which the 3' splice a peripheral loop (L6a) and rearranged so that the 3' half site is artificially placed upstream of the 5' splice site will intron and 3' splice site are upstream and a 5' splice site and carry out intramolecular cis-splicing to produce circles in 5' half intron are do eam of a single exon. The group I vitro (16-18). Galloway-Salvo et al. (19) showed that separate splici reactions excise the internal exon RNA as a circle (RNA transcripts, each containing half ofa T4 td intron split in L6a cyclase ribozyme activity). We show that foreign sequences can (20, 21) carry out group I trans-splicing in vivo, suggesting be placed in the exon and made circular in vitro.
    [Show full text]
  • Circular Rnas: Diversity of Form and Function
    Downloaded from rnajournal.cshlp.org on October 4, 2021 - Published by Cold Spring Harbor Laboratory Press REVIEW Circular RNAs: diversity of form and function ERIKA LASDA and ROY PARKER Department of Chemistry and Biochemistry, Howard Hughes Medical Institute, University of Colorado, Boulder, Colorado 80309, USA ABSTRACT It is now clear that there is a diversity of circular RNAs in biological systems. Circular RNAs can be produced by the direct ligation of 5′ and 3′ ends of linear RNAs, as intermediates in RNA processing reactions, or by “backsplicing,” wherein a downstream 5′ splice site (splice donor) is joined to an upstream 3′ splice site (splice acceptor). Circular RNAs have unique properties including the potential for rolling circle amplification of RNA, the ability to rearrange the order of genomic information, protection from exonucleases, and constraints on RNA folding. Circular RNAs can function as templates for viroid and viral replication, as intermediates in RNA processing reactions, as regulators of transcription in cis, as snoRNAs, and as miRNA sponges. Herein, we review the breadth of circular RNAs, their biogenesis and metabolism, and their known and anticipated functions. Keywords: circRNA; circular RNA; backsplicing; splicing; intron; intermediates; nonlinear INTRODUCTION DIFFERENT TYPES OF RNA CIRCLES In addition to the classic tRNA, mRNA, and rRNAs, cells Circular RNA genomes—viroid and contain a striking diversity of additional RNA types includ- hepatitis delta virus circles ing miRNAs, lncRNAs, piRNAs, siRNAs, tmRNAs, sRNAs, tiRNAs, eRNAs, snoRNAs, snRNAs, and other noncoding One class of circular single-stranded RNAs (ssRNAs) are vi- RNAs. A growing component of this family of diverse RNA roids and the hepatitis delta virus (HDV).
    [Show full text]
  • RNA: Circular Rnas As Mirna Sponges
    RESEARCH HIGHLIGHTS IN BRIEF DEVELOPMENT A biphasic push breaks symmetry During oocyte maturation, polar body extrusion results from two asymmetric meiotic cell divisions that depend on the chromosome–spindle complex migrating from the oocyte centre to a subcortical location. Li and colleagues report that this migration occurs in two phases during meiosis I. The first phase was slow and dependent on formin 2 (FMN2). FMN2 colocalized with endoplasmic reticulum structures that surround the spindle and promoted local F-actin nucleation, which pushed the chromosome–spindle complex away from the centre. The second phase was rapid, driven by cytoplasmic streaming and initiated upon activation of a cortical actin-related protein 2/3 (ARP2/3) complex as chromosomes approached the cortex. ORIGINAL RESEARCH PAPER Yi, K. et al. Sequential actin-based pushing forces drive meiosis I chromosome migration and symmetry breaking in oocytes. J. Cell Biol. 200, 567–576 (2013) CELL SIGNALLING Transducing mechanical signals Mechanosensing is a vital cellular process, but how cells transduce mechanical stimuli is not well defined. Here, Ulbricht et al. report that, in mammalian cells, tension-induced unfolding of the cytoskeleton protein filamin is sensed by BAG3, a component of the CASA (chaperone-assisted selective autophagy) complex. BAG3 binds to unfolded filamin and to the adaptor protein synaptopodin 2 (SYNPO2); SYNPO2 links the CASA complex to a membrane-tethering and fusion complex, which leads to autophagosome formation and filamin degradation. In addition, BAG3 stimulates the transcriptional activators YAP and TAZ, which leads to increased filamin mRNA and protein levels. Thus, by regulating the degradation and transcription of filamin in mechanically strained cells, BAG3 is a key transducer of mechanical signals.
    [Show full text]
  • Circznf827 Nucleates a Transcription Inhibitory Complex to Balance
    RESEARCH ARTICLE circZNF827 nucleates a transcription inhibitory complex to balance neuronal differentiation Anne Kruse Hollensen1, Henriette Sylvain Thomsen1, Marta Lloret-Llinares1,2, Andreas Bjerregaard Kamstrup1, Jacob Malte Jensen3, Majbritt Luckmann1, Nanna Birkmose1, Johan Palmfeldt4, Torben Heick Jensen1, Thomas B Hansen1, Christian Kroun Damgaard1* 1Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; 2European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory, Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom; 3Bioinformatics Research Centre, Aarhus University, Aarhus, Denmark; 4Department of Clinical Medicine, Research Unit for Molecular Medicine, Aarhus University, Aarhus, Denmark Abstract Circular RNAs are important for many cellular processes but their mechanisms of action remain poorly understood. Here, we map circRNA inventories of mouse embryonic stem cells, neuronal progenitor cells and differentiated neurons and identify hundreds of highly expressed circRNAs. By screening several candidate circRNAs for a potential function in neuronal differentiation, we find that circZNF827 represses expression of key neuronal markers, suggesting that this molecule negatively regulates neuronal differentiation. Among 760 tested genes linked to known neuronal pathways, knockdown of circZNF827 deregulates expression of numerous genes including nerve growth factor receptor (NGFR), which becomes transcriptionally upregulated to enhance NGF signaling. We identify a circZNF827-nucleated
    [Show full text]
  • Computational Design of a Circular RNA with Prionlike Behavior
    Stefan Badelt** Computational Design of † Christoph Flamm**, † ‡ a Circular RNA with Ivo L. Hofacker*,**, , Prionlike Behavior University of Vienna Keywords RNA structure, sequence design, self-replication, folding kinetics Abstract RNA molecules engineered to fold into predefined conformations have enabled the design of a multitude of functional RNA devices in the field of synthetic biology and nanotechnology. More complex designs require efficient computational methods, which need to consider not only equilibrium thermodynamics but also the kinetics of structure formation. Here we present a novel type of RNA design that mimics the behavior of prions, that is, sequences capable of interaction-triggered autocatalytic replication of conformations. Our design was computed with the ViennaRNA package and is based on circular RNA that embeds domains amenable to intermolecular kissing interactions. 1 Introduction During the last decade, the field of synthetic biology has impressively illustrated that nucleic acids and in particular RNA molecules are reliable materials for the design and implementation of func- tional circuits as well as nano-scale devices and objects [18, 24, 1, 23]. The reasons for this success are grounded in the facts that for RNA (i) an experimentally measured energy model exists, (ii) regulation at the level of RNA molecules is faster than via the production of proteins, and (iii) design questions are more readily expressed in the discrete framework of binary base pairing than in con- tinuous interactions between, say, the amino acids in proteins. 1.1 RNA Design RNA molecules have been extensively engineered in the classical context of gene regulation. Suc- cessful designs include Boolean networks with miRNAs [27, 34, 47], synthetic RNA switches [22, 40, 17], and artificial ribozymes [43, 13].
    [Show full text]
  • The Identification of Meccirnas and Their Roles in Mitochondrial Entry of Proteins
    bioRxiv preprint doi: https://doi.org/10.1101/668665; this version posted June 12, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. The identification of mecciRNAs and their roles in mitochondrial entry of proteins Xu Liu1, Xiaolin Wang1, Jingxin Li1, Shanshan Hu2, Yuqi Deng1, Hao Yin1, Xichen Bao3, Qiangfeng Cliff Zhang4, Geng Wang4, Baolong Wang1, Qinghua Shi1, 5, Ge Shan1, 5, 6, * 1. Department of Clinical Laboratory, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China. 2. Department of neurosurgery, The First Affiliated Hospital of University of Science and Technology of China, Hefei 230001, China. 3. Key Laboratory of Regenerative Biology of the Chinese Academy of Sciences, Joint School of Life Sciences, Guangzhou Medical University and Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China. 4. MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China. 5. CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, CAS, Shanghai 200031, China 6. Lead Contact *Correspondence should be addressed to Ge Shan ([email protected]). Abstract Mammalian mitochondria have small genomes encoding very limited numbers of proteins. Over one thousand proteins and noncoding RNAs encoded by nuclear genome have to be imported from the cytosol into the mitochondria.
    [Show full text]
  • The Enigma of Circular
    RESEARCH HIGHLIGHTS this model. Tape stripping increased stimulates ILC2s to produce IL-4 the number of tuft cells in the small and IL-13 that stimulate IL-25 intestine and their expression of production by tuft cells, which Il25 mRNA. Mice lacking tuft cell- further promotes ILC2 activation. Getty Credit: specific expression of IL-25 did not IL-4 and IL-13 also signal directly to have increased numbers of intestinal mast cells, such that in tape-stripped mast cells after tape stripping. mice with ILC2-specific deficiency Group 2 innate lymphoid cells of IL-4 and IL-13 or with mast cell- (ILC2s) are known targets for IL-33 specific deficiency of IL-4 receptor and IL-25, and experiments with and IL-13 receptor, there is a mice lacking ILC2s showed that decreased oral anaphylaxis response. they are required for the mast cell The authors suggest that this response to tape stripping. Tape pathway connecting mechanical stripping increased the number skin injury to intestinal responses of ILC2s in the small intestine evolved to protect the gut from and increased their expression helminth infections that breach INNATE IMMUNITY of Il4, Il5 and Il13 mRNAs. This the skin barrier. Its relevance to response was abolished in mice atopic responses in humans was The enigma of circular RNA lacking keratinocyte-specific IL-33 shown by the expanded mast cell expression or tuft cell-specific IL-25 populations observed in duodenal Circular RNAs (circRNAs), which are generated through expression, as well as in mice lacking biopsies from patients with atopic back-splicing of pre-mRNAs, are stable and widely expressed, ILC2 expression of the receptors dermatitis compared with controls, but their biological role has remained a mystery.
    [Show full text]