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1.
Genes Dev ; 33(1-2): 90-102, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30567997

RESUMO

Piwi-interacting RNAs (piRNAs) engage Piwi proteins to suppress transposons and nonself nucleic acids and maintain genome integrity and are essential for fertility in a variety of organisms. In Caenorhabditis elegans, most piRNA precursors are transcribed from two genomic clusters that contain thousands of individual piRNA transcription units. While a few genes have been shown to be required for piRNA biogenesis, the mechanism of piRNA transcription remains elusive. Here we used functional proteomics approaches to identify an upstream sequence transcription complex (USTC) that is essential for piRNA biogenesis. The USTC contains piRNA silencing-defective 1 (PRDE-1), SNPC-4, twenty-one-U fouled-up 4 (TOFU-4), and TOFU-5. The USTC forms unique piRNA foci in germline nuclei and coats the piRNA cluster genomic loci. USTC factors associate with the Ruby motif just upstream of type I piRNA genes. USTC factors are also mutually dependent for binding to the piRNA clusters and forming the piRNA foci. Interestingly, USTC components bind differentially to piRNAs in the clusters and other noncoding RNA genes. These results reveal the USTC as a striking example of the repurposing of a general transcription factor complex to aid in genome defense against transposons.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Regulação da Expressão Gênica/genética , RNA Interferente Pequeno/genética , Motivos de Aminoácidos , Animais , Proteínas de Caenorhabditis elegans/genética , Genoma Helmíntico/genética , Ligação Proteica , Proteômica , RNA Interferente Pequeno/biossíntese
2.
PLoS Genet ; 19(2): e1010628, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36763670

RESUMO

Temperature greatly affects numerous biological processes in all organisms. How multicellular organisms respond to and are impacted by hypothermic stress remains elusive. Here, we found that cold-warm stimuli induced depletion of the RNA exosome complex in the nucleoli but enriched it in the nucleoplasm. To further understand the function and mechanism of cold-warm stimuli, we conducted forward genetic screening and identified ZTF-7, which is required for RNA exosome depletion from nucleoli upon transient cold-warm exposure in C. elegans. ZTF-7 is a putative ortholog of human ZNF277 that may contribute to language impairments. Immunoprecipitation followed by mass spectrometry (IP-MS) found that ZTF-7 interacted with RPS-2, which is a ribosomal protein of the small subunit and participates in pre-rRNA processing. A partial depletion of RPS-2 and other proteins of the small ribosomal subunit blocked the cold-warm stimuli-induced reduction of exosome subunits from the nucleoli. These results established a novel mechanism by which C. elegans responds to environmental cold-warm exposure.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Humanos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Núcleo Celular/metabolismo , Temperatura Baixa , Temperatura , Ligação Proteica
3.
Pharmacol Res ; 205: 107236, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38797358

RESUMO

The rapid antidepressant effects of ketamine depend on the N-methyl-D-aspartate (NMDA) receptor containing 2B subunit (NR2B), whose function is influenced by its phosphorylated regulation and distribution within and outside synapses. It remains unclear if ketamine's rapid onset of antidepressant effects relies on the dynamic phosphorylated regulation of NR2B within and outside synapses. Here, we show that ketamine rapidlyalleviated depression-like behaviors and normalized abnormal expression of pTyr1472NR2B and striatal-enriched protein tyrosine phosphatase (STEP) 61 within and outside synapses in the medial prefrontal cortex (mPFC) induced by chronic unpredictable stress (CUS) and conditional knockdown of STEP 61, a key phosphatase of NR2B, within 1 hour after administration Together, our results delineate the rapid initiation of ketamine's antidepressant effects results from the restoration of NR2B phosphorylation homeostasis within and outside synapses. The dynamic regulation of phosphorylation of NR2B provides a new perspective for developing new antidepressant strategies.


Assuntos
Antidepressivos , Depressão , Ketamina , Camundongos Endogâmicos C57BL , Córtex Pré-Frontal , Receptores de N-Metil-D-Aspartato , Receptores de N-Metil-D-Aspartato/metabolismo , Ketamina/farmacologia , Animais , Fosforilação/efeitos dos fármacos , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Masculino , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , Depressão/tratamento farmacológico , Depressão/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Tirosina/metabolismo , Camundongos , Estresse Psicológico/metabolismo , Estresse Psicológico/tratamento farmacológico , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Comportamento Animal/efeitos dos fármacos
4.
Proc Natl Acad Sci U S A ; 118(27)2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34187893

RESUMO

PIWI-interacting RNAs (piRNAs) play significant roles in suppressing transposons, maintaining genome integrity, and defending against viral infections. How piRNA source loci are efficiently transcribed is poorly understood. Here, we show that in Caenorhabditis elegans, transcription of piRNA clusters depends on the chromatin microenvironment and a chromodomain-containing protein, UAD-2. piRNA clusters form distinct focus in germline nuclei. We conducted a forward genetic screening and identified UAD-2 that is required for piRNA focus formation. In the absence of histone 3 lysine 27 methylation or proper chromatin-remodeling status, UAD-2 is depleted from the piRNA focus. UAD-2 recruits the upstream sequence transcription complex (USTC), which binds the Ruby motif to piRNA promoters and promotes piRNA generation. Vice versa, the USTC complex is required for UAD-2 to associate with the piRNA focus. Thus, transcription of heterochromatic small RNA source loci relies on coordinated recruitment of both the readers of histone marks and the core transcriptional machinery to DNA.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Heterocromatina/metabolismo , RNA Interferente Pequeno/metabolismo , Animais , Caenorhabditis elegans/genética , Montagem e Desmontagem da Cromatina , Testes Genéticos , Células Germinativas/citologia , Células Germinativas/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Metilação , Peptídeos/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Ligação Proteica , Temperatura
5.
Nucleic Acids Res ; 49(16): 9194-9210, 2021 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-34365510

RESUMO

Eukaryotic cells express a wide variety of endogenous small regulatory RNAs that function in the nucleus. We previously found that erroneous rRNAs induce the generation of antisense ribosomal siRNAs (risiRNAs) which silence the expression of rRNAs via the nuclear RNAi defective (Nrde) pathway. To further understand the biological roles and mechanisms of this class of small regulatory RNAs, we conducted forward genetic screening to identify factors involved in risiRNA generation in Caenorhabditis elegans. We found that risiRNAs accumulated in the RNA exosome mutants. risiRNAs directed the association of NRDE proteins with pre-rRNAs and the silencing of pre-rRNAs. In the presence of risiRNAs, NRDE-2 accumulated in the nucleolus and colocalized with RNA polymerase I. risiRNAs inhibited the transcription elongation of RNA polymerase I by decreasing RNAP I occupancy downstream of the RNAi-targeted site. Meanwhile, exosomes mislocalized from the nucleolus to nucleoplasm in suppressor of siRNA (susi) mutants, in which erroneous rRNAs accumulated. These results established a novel model of rRNA surveillance by combining ribonuclease-mediated RNA degradation with small RNA-directed nucleolar RNAi system.


Assuntos
RNA Ribossômico/metabolismo , RNA Interferente Pequeno/metabolismo , Elongação da Transcrição Genética , Animais , Caenorhabditis elegans , Nucléolo Celular/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Exossomos/genética , Exossomos/metabolismo , Inativação Gênica , Mutação , RNA Ribossômico/genética , RNA Interferente Pequeno/genética
6.
Aging Clin Exp Res ; 33(6): 1465-1475, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32767273

RESUMO

BACKGROUND: Major depressive disorder is a global public health problem among older adults. Many studies show that problem-solving therapy (PST) is a cognitive behavioral approach that can effectively treat late-life depression. AIM: To summarize and assess the effects of PST on major depressive disorders in older adults. METHODS: We searched the PubMed, Web of Science, Cochrane Library, EMBASE, MEDLINE, UpToDate, and PsycINFO databases and three Chinese databases (CNKI, CBM, and Wan Fang Data) to identify articles written in English or Chinese that were published until Feb 1, 2020. Randomized controlled trials were included if they evaluated the impact of PST on major depression disorder (MDD) in older adults. Two authors of this review independently selected the studies, assessed the risk of bias, and extracted the data from all the included studies. We calculated the standard mean differences (SMDs) with 95% confidence intervals (CIs) for continuous data. We assessed heterogeneity using the I2 statistic. RESULTS: Ten studies with a total of 892 participants met the inclusion criteria. Subgroup analyses and quality ratings were performed. After problem-solving therapy, the depression scores in the intervention group were significantly lower than those in the control group (SMD = - 1.06, 95% CI - 1.52 to - 0.61, p < 0.05; I2 = 88.4%). DISCUSSION: Compared with waitlist (WL), PST has a significant effect on elderly patients with depression, but we cannot rank the therapeutic effects of all the treatment methods used for MDD. CONCLUSIONS: Our meta-analysis and systematic review suggest that problem-solving therapy may be an effective approach to improve major depressive disorders in older adults.


Assuntos
Terapia Cognitivo-Comportamental , Transtorno Depressivo Maior , Idoso , Transtorno Depressivo Maior/terapia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
Proc Natl Acad Sci U S A ; 115(40): 10082-10087, 2018 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-30224484

RESUMO

Ribosome biogenesis is a multistep process, during which mistakes can occur at any step of pre-rRNA processing, modification, and ribosome assembly. Misprocessed rRNAs are usually detected and degraded by surveillance machineries. Recently, we identified a class of antisense ribosomal siRNAs (risiRNAs) that down-regulate pre-rRNAs through the nuclear RNAi pathway. To further understand the biological roles of risiRNAs, we conducted both forward and reverse genetic screens to search for more suppressor of siRNA (susi) mutants. We isolated a number of genes that are broadly conserved from yeast to humans and are involved in pre-rRNA modification and processing. Among them, SUSI-2(ceRRP8) is homologous to human RRP8 and engages in m1A methylation of the 26S rRNA. C27F2.4(ceBUD23) is an m7G-methyltransferase of the 18S rRNA. E02H1.1(ceDIMT1L) is a predicted m6(2)Am6(2)A-methyltransferase of the 18S rRNA. Mutation of these genes led to a deficiency in modification of rRNAs and elicited accumulation of risiRNAs, which further triggered the cytoplasmic-to-nuclear and cytoplasmic-to-nucleolar translocations of the Argonaute protein NRDE-3. The rRNA processing deficiency also resulted in accumulation of risiRNAs. We also isolated SUSI-3(RIOK-1), which is similar to human RIOK1, that cleaves the 20S rRNA to 18S. We further utilized RNAi and CRISPR-Cas9 technologies to perform candidate-based reverse genetic screens and identified additional pre-rRNA processing factors that suppressed risiRNA production. Therefore, we concluded that erroneous rRNAs can trigger risiRNA generation and subsequently, turn on the nuclear RNAi-mediated gene silencing pathway to inhibit pre-rRNA expression, which may provide a quality control mechanism to maintain homeostasis of rRNAs.


Assuntos
Inativação Gênica , Metiltransferases , Proteínas Nucleares , RNA Ribossômico 18S , RNA Ribossômico , RNA Interferente Pequeno , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Humanos , Metiltransferases/genética , Metiltransferases/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteína O-Metiltransferase , RNA Ribossômico/genética , RNA Ribossômico/metabolismo , RNA Ribossômico 18S/genética , RNA Ribossômico 18S/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
8.
Biol Cell ; 110(10): 217-224, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30132958

RESUMO

Epigenetic information can be inherited over multiple generations, which is termed as transgenerational epigenetic inheritance (TEI). Although the mechanism(s) of TEI remains poorly understood, noncoding RNAs have been demonstrated to play important roles in TEI. In many eukaryotes, double-stranded RNA (dsRNA) triggers the silencing of cellular nucleic acids that exhibit sequence homology to the dsRNA via a process termed RNA interference (RNAi). In Caenorhabditis elegans, dsRNA-directed gene silencing is heritable and can persist for a number of generations after its initial induction. During the process, small RNAs and the RNAi machinery mediate the initiation, transmission and re-establishment of the gene silencing state. In this review, we summarise our current understanding of the underlying mechanism(s) of transgenerational inheritance of RNAi in C. elegans and propose that multiple RNAi machineries may act cooperatively to promote TEI.


Assuntos
Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Interferência de RNA , Animais , Epigênese Genética/genética
9.
RNA Biol ; 14(11): 1492-1498, 2017 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-28640690

RESUMO

Ribosome biogenesis drives cell growth and proliferation, but mechanisms that modulate this process remain poorly understood. For a long time, small rRNA sequences have been widely treated as non-specific degradation products and neglected as garbage sequences. Recently, we identified a new class of antisense ribosomal siRNAs (risiRNAs) that downregulate pre-rRNA through the nuclear RNAi pathway in C. elegans. risiRNAs exhibit sequence characteristics similar to 22G RNA while complement to 18S and 26S rRNA. risiRNAs elicit the translocation of the nuclear Argonaute protein NRDE-3 from the cytoplasm to nucleus and nucleolus, in which the risiRNA/NRDE complex binds to pre-rRNA and silences rRNA expression. Interestingly, when C. elegans is exposed to environmental stimuli, such as cold shock and ultraviolet illumination, risiRNAs accumulate and further turn on the nuclear RNAi-mediated gene silencing pathway. risiRNA may act in a quality control mechanism of rRNA homeostasis. When the exoribonuclease SUSI-1(ceDis3L2) is mutated, risiRNAs are dramatically increased. In this Point of View article, we will summarize our understanding of the small antisense ribosomal siRNAs in a variety of organisms, especially C. elegans, and their possible roles in the quality control mechanism of rRNA homeostasis.


Assuntos
Caenorhabditis elegans/genética , Interferência de RNA , Precursores de RNA/genética , RNA Ribossômico/genética , RNA Interferente Pequeno/genética , Ribossomos/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Exorribonucleases/genética , Exorribonucleases/metabolismo , Homeostase , Neurospora crassa/genética , Neurospora crassa/metabolismo , Ligação Proteica , Transporte Proteico , Precursores de RNA/metabolismo , RNA Ribossômico/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ribossomos/genética
10.
Psychiatry Res ; 332: 115637, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38150810

RESUMO

Second-generation antipsychotics (SGAs) are widely used in treating schizophrenia and related disorders, also other mental disorders. However, the efficacy and safety of SGAs for treating other mental disorders is unclear. A systematic literature search for randomized, placebo-controlled trials of 11 SGAs for treating 18 mental disorders apart from schizophrenia were carried out from database inception to April 3, 2022. The primary outcome was the mean change in the total score for different mental disorders. The secondary outcome was the odds ratio (OR) of response, remission rates and risk ratio (RR) of adverse events (AEs). A total of 181 studies (N = 65,480) were included. All SGAs showed significant effects in treating other mental disorders compared with placebo, except autistic disorder and dementia. Aripiprazole is the most effective treatment for bipolar mania [effect size = -0.90, 95% CI: -1.59, -0.21] and Tourette's disorder [effect size = -0.80, 95% CI: -1.14, -0.45], olanzapine for bipolar depression [effect size = -0.86, 95% CI: -1.32, -0.39] and post-traumatic stress disorder [effect size = -0.98, 95% CI: -1.55, -0.41], lurasidone for depression [effect size = -0.66, 95% CI: -0.82, -0.50], quetiapine for anxiety [effect size = -1.20, 95% CI: -1.96, -0.43], sleep disorders [effect size = -1.2, 95% CI: -1.97, -0.58], and delirium [effect size = -0.36, 95% CI: -0.70, -0.03], and risperidone for obsessive-compulsive disorder [effect size = -2.37, 95% CI: -3.25, -1.49], respectively. For safety, AE items for each SGAs was different. Interestingly, we found that some AEs of OLZ, QTP, RIS and PALI have significant palliative effects on some symptoms. Significant differences in the efficacy and safety of different SGAs for treatment of other mental disorders should be considered for choosing the drug and for the balance between efficacy and tolerability for the specific patient.


Assuntos
Antipsicóticos , Esquizofrenia , Humanos , Antipsicóticos/efeitos adversos , Antipsicóticos/uso terapêutico , Olanzapina/efeitos adversos , Olanzapina/uso terapêutico , Fumarato de Quetiapina/efeitos adversos , Fumarato de Quetiapina/uso terapêutico , Risperidona/efeitos adversos , Risperidona/uso terapêutico , Esquizofrenia/tratamento farmacológico
11.
Nat Commun ; 15(1): 5799, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987544

RESUMO

Germ granules are biomolecular condensates present in most animal germ cells. One function of germ granules is to help maintain germ cell totipotency by organizing mRNA regulatory machinery, including small RNA-based gene regulatory pathways. The C. elegans germ granule is compartmentalized into multiple subcompartments whose biological functions are largely unknown. Here, we identify an uncharted subcompartment of the C. elegans germ granule, which we term the E granule. The E granule is nonrandomly positioned within the germ granule. We identify five proteins that localize to the E granule, including the RNA-dependent RNA polymerase (RdRP) EGO-1, the Dicer-related helicase DRH-3, the Tudor domain-containing protein EKL-1, and two intrinsically disordered proteins, EGC-1 and ELLI-1. Localization of EGO-1 to the E granule enables synthesis of a specialized class of 22G RNAs, which derive exclusively from 5' regions of a subset of germline-expressed mRNAs. Defects in E granule assembly elicit disordered production of endogenous siRNAs, which disturbs fertility and the RNAi response. Our results define a distinct subcompartment of the C. elegans germ granule and suggest that one function of germ granule compartmentalization is to facilitate the localized production of specialized classes of small regulatory RNAs.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Grânulos Citoplasmáticos , Células Germinativas , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Animais , Células Germinativas/metabolismo , Grânulos Citoplasmáticos/metabolismo , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/genética , RNA Polimerase Dependente de RNA/metabolismo , RNA Polimerase Dependente de RNA/genética , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas Intrinsicamente Desordenadas/genética
12.
Stem Cells ; 30(3): 461-70, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22213079

RESUMO

Unlike mouse embryonic stem cells (ESCs), which are closely related to the inner cell mass, human ESCs appear to be more closely related to the later primitive ectoderm. For example, human ESCs and primitive ectoderm share a common epithelial morphology, growth factor requirements, and the potential to differentiate to all three embryonic germ layers. However, it has previously been shown that human ESCs can also differentiate to cells expressing markers of trophoblast, an extraembryonic lineage formed before the formation of primitive ectoderm. Here, we show that phorbol ester 12-O-tetradecanoylphorbol 13-acetate causes human ESCs to undergo an epithelial mesenchymal transition and to differentiate into cells expressing markers of parietal endoderm, another extraembryonic lineage. We further confirmed that this differentiation is through the activation of protein kinase C (PKC) pathway and demonstrated that a particular PKC subtype, PKC-δ, is most responsible for this transition.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Células-Tronco Embrionárias/fisiologia , Endoderma/citologia , Proteína Quinase C/fisiologia , Antígenos de Diferenciação/metabolismo , Células Cultivadas , Regulação para Baixo , Células-Tronco Embrionárias/metabolismo , Ativação Enzimática , Ativadores de Enzimas/farmacologia , Transição Epitelial-Mesenquimal , Perfilação da Expressão Gênica , Humanos , Isoenzimas/metabolismo , Isoenzimas/fisiologia , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Proteína Quinase C/metabolismo , Acetato de Tetradecanoilforbol/farmacologia
13.
Nat Commun ; 14(1): 1254, 2023 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-36878913

RESUMO

The chromatin organization modifier domain (chromodomain) is an evolutionally conserved motif across eukaryotic species. The chromodomain mainly functions as a histone methyl-lysine reader to modulate gene expression, chromatin spatial conformation and genome stability. Mutations or aberrant expression of chromodomain proteins can result in cancer and other human diseases. Here, we systematically tag chromodomain proteins with green fluorescent protein (GFP) using CRISPR/Cas9 technology in C. elegans. By combining ChIP-seq analysis and imaging, we delineate a comprehensive expression and functional map of chromodomain proteins. We then conduct a candidate-based RNAi screening and identify factors that regulate the expression and subcellular localization of the chromodomain proteins. Specifically, we reveal an H3K9me1/2 reader, CEC-5, both by in vitro biochemistry and in vivo ChIP assays. MET-2, an H3K9me1/2 writer, is required for CEC-5 association with heterochromatin. Both MET-2 and CEC-5 are required for the normal lifespan of C. elegans. Furthermore, a forward genetic screening identifies a conserved Arginine124 of CEC-5's chromodomain, which is essential for CEC-5's association with chromatin and life span regulation. Thus, our work will serve as a reference to explore chromodomain functions and regulation in C. elegans and allow potential applications in aging-related human diseases.


Assuntos
Envelhecimento , Caenorhabditis elegans , Animais , Humanos , Envelhecimento/genética , Caenorhabditis elegans/genética , Cromatina/genética , Proteínas de Fluorescência Verde , Longevidade , Histonas/metabolismo
14.
Cell Rep ; 42(8): 112915, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37537842

RESUMO

The nucleolus is the most prominent membraneless organelle within the nucleus. How the nucleolar structure is regulated is poorly understood. Here, we identified two types of nucleoli in C. elegans. Type I nucleoli are spherical and do not have visible nucleolar vacuoles (NoVs), and rRNA transcription and processing factors are evenly distributed throughout the nucleolus. Type II nucleoli contain vacuoles, and rRNA transcription and processing factors exclusively accumulate in the periphery rim. The NoV contains nucleoplasmic proteins and is capable of exchanging contents with the nucleoplasm. The high-order structure of the nucleolus is dynamically regulated in C. elegans. Faithful rRNA processing is important to prohibit NoVs. The depletion of 27SA2 rRNA processing factors resulted in NoV formation. The inhibition of RNA polymerase I (RNAPI) transcription and depletion of two conserved nucleolar factors, nucleolin and fibrillarin, prohibits the formation of NoVs. This finding provides a mechanism to coordinate structure maintenance and gene expression.


Assuntos
Caenorhabditis elegans , Proteínas Nucleares , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas Nucleares/metabolismo , Vacúolos/metabolismo , Nucléolo Celular/metabolismo , Núcleo Celular/metabolismo , RNA Ribossômico/metabolismo
15.
Gen Hosp Psychiatry ; 83: 156-163, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37201445

RESUMO

BACKGROUND: Previous reports had linked depression to thyroid function. However, the relationship between thyroid function and clinical characteristics in major depressive disorder (MDD) patients with suicidal attempts (SA) is still unclear. AIMS: This study aims to reveal the association between thyroid autoimmunity and clinical characteristics in depressed patients with SA. METHODS: We divided 1718 first-episode and drug-naive MDD patients into groups with suicide attempt (MDD-SA) and without suicide attempt (MDD-NSA). Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), and the positive subscale of the Positive and Negative Syndrome Scale (PANSS) were assessed; thyroid function and autoantibodies were detected. RESULTS: The total scores of HAMD, HAMA and psychotic positive symptoms were significantly higher in patients with MDD-SA, accompanied by higher levels of TSH, TG-Ab and TPO-Ab, than in patients with MDD-NSA, without gender differences. Total scores of positive symptoms (TSPS) in MDD-SA patients with increased TSH or TG-Ab was significantly higher than in MDD-NSA patients and in MDD-SA patients with normal TSH and TG-Ab. The proportion of elevated-TSPS in MDD-SA patients was >4 times that in MDD-NSA patients. The proportion of MDD-SA patients with elevated-TSPS was >3 times that with not-elevated TSPS patients. CONCLUSIONS: Thyroid autoimmune abnormalities and psychotic positive symptoms may be the clinical features of MDD-SA patients. Psychiatrists should be more alert to the possibility of suicidal behaviors when they first encounter such a patient.


Assuntos
Transtorno Depressivo Maior , Humanos , Transtorno Depressivo Maior/diagnóstico , Tentativa de Suicídio , Glândula Tireoide , Autoimunidade , Tireotropina
16.
J Genet Genomics ; 49(10): 952-964, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35283340

RESUMO

Dietary restriction usually suppresses biosynthesis but activates catabolic pathways in animals. However, the short-term starvation enhances biosynthetic activities and promotes ribosomal biogenesis in adult Caenorhabditis elegans. The mechanism underlying the processes remains largely unknown. Here, we find that the short-term starvation enhances the SL1 trans-splicing of translation-related genes in adult C. elegans by transcriptome analysis. The small nuclear RNA-activating protein complex (SNAPc) promotes SL RNA production and mediates starvation-induced trans-splicing. TOFU-5, a core factor in the upstream sequence transcription complex (USTC) essential for piRNA production, is also involved in the starvation-induced trans-splicing processes. Knocking down components of the SNAPc complex and tofu-5 extends worm survival under starvation conditions. Taken together, our study highlights the importance of SL trans-splicing in the nutrition response and reveals a mechanism of the survival regulation by food deprivation via SNAPc and TOFU-5.


Assuntos
Caenorhabditis elegans , Trans-Splicing , Animais , Trans-Splicing/genética , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , RNA Líder para Processamento/genética , RNA Líder para Processamento/metabolismo , RNA Nuclear Pequeno/metabolismo , RNA Interferente Pequeno
17.
Elife ; 112022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36125117

RESUMO

Histone methylation plays crucial roles in the development, gene regulation, and maintenance of stem cell pluripotency in mammals. Recent work shows that histone methylation is associated with aging, yet the underlying mechanism remains unclear. In this work, we identified a class of putative histone 3 lysine 9 mono/dimethyltransferase genes (met-2, set-6, set-19, set-20, set-21, set-32, and set-33), mutations in which induce synergistic lifespan extension in the long-lived DAF-2 (insulin growth factor 1 [IGF-1] receptor) mutant in Caenorhabditis elegans. These putative histone methyltransferase plus daf-2 double mutants not only exhibited an average lifespan nearly three times that of wild-type animals and a maximal lifespan of approximately 100 days, but also significantly increased resistance to oxidative and heat stress. Synergistic lifespan extension depends on the transcription factor DAF-16 (FOXO). mRNA-seq experiments revealed that the mRNA levels of DAF-16 Class I genes, which are activated by DAF-16, were further elevated in the daf-2;set double mutants. Among these genes, tts-1, F35E8.7, ins-35, nhr-62, sod-3, asm-2, and Y39G8B.7 are required for the lifespan extension of the daf-2;set-21 double mutant. In addition, treating daf-2 animals with the H3K9me1/2 methyltransferase G9a inhibitor also extends lifespan and increases stress resistance. Therefore, investigation of DAF-2 and H3K9me1/2 deficiency-mediated synergistic longevity will contribute to a better understanding of the molecular mechanisms of aging and therapeutic applications.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Histona Metiltransferases/metabolismo , Histonas/genética , Histonas/metabolismo , Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Longevidade/genética , Lisina/metabolismo , Mamíferos/genética , Metilação , Metiltransferases/genética , Metiltransferases/metabolismo , RNA Mensageiro/metabolismo , Receptor de Insulina/genética , Receptor de Insulina/metabolismo
18.
Proc Natl Acad Sci U S A ; 105(11): 4093-8, 2008 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-18326628

RESUMO

Epigenetic regulation through chromatin is thought to play a critical role in the establishment and maintenance of pluripotency. Traditionally, antibody-based technologies were used to probe for specific posttranslational modifications (PTMs) present on histone tails, but these methods do not generally reveal the presence of multiple modifications on a single-histone tail (combinatorial codes). Here, we describe technology for the discovery and quantification of histone combinatorial codes that is based on chromatography and mass spectrometry. We applied this methodology to decipher 74 discrete combinatorial codes on the tail of histone H4 from human embryonic stem (ES) cells. Finally, we quantified the abundances of these codes as human ES cells undergo differentiation to reveal striking changes in methylation and acetylation patterns. For example, H4R3 methylation was observed only in the presence of H4K20 dimethylation; such context-specific patterning exemplifies the power of this technique.


Assuntos
Diferenciação Celular , Células-Tronco Embrionárias/química , Células-Tronco Embrionárias/citologia , Sequência de Aminoácidos , Linhagem Celular , Células-Tronco Embrionárias/metabolismo , Histonas , Humanos , Espectrometria de Massas , Dados de Sequência Molecular , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo
19.
Nat Commun ; 12(1): 5595, 2021 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-34552083

RESUMO

By incorporating two mutually exclusive factors, PID-1 and TOST-1, C. elegans PICS complex plays important roles in piRNA biogenesis, chromosome segregation and cell division. We firstly map the interaction network between PICS subunits, then uncover the mechanisms underlying the interactions between PICS subunits by solving several complex structures, including those of TOFU-6/PICS-1, ERH-2/PICS-1, and ERH-2/TOST-1. Our biochemical experiment also demonstrates that PICS exists as an octamer consisting of two copies of each subunit. Combining structural analyses with mutagenesis experiments, we identify interfacial residues of PICS subunits that are critical for maintaining intact PICS complex in vitro. Furthermore, using genetics, cell biology and imaging experiments, we find that those mutants impairing the in vitro interaction network within PICS, also lead to dysfunction of PICS in vivo, including mislocalization of PICS, and reduced levels of piRNAs or aberrant chromosome segregation and cell division. Therefore, our work provides structural insights into understanding the PICS-mediated piRNA biogenesis and cell division.


Assuntos
Proteínas de Caenorhabditis elegans/química , Divisão Celular , RNA Interferente Pequeno/biossíntese , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Segregação de Cromossomos , Cristalografia por Raios X , Espaço Intracelular/metabolismo , Complexos Multiproteicos , Mutagênese , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Subunidades Proteicas
20.
Asian J Psychiatr ; 53: 102169, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32446215

RESUMO

Morita therapy was developed for common mental problems, and our aim was to evaluate the clinical effect of Morita therapy on schizophrenia. The literature was searched in 10 databases, namely, PubMed, Chinese National Knowledge Infrastructure (CNKI), Sinomed, Wanfang, Cochrane Library, UpToDate, Web of Science, Medline, PsycINFO and Embase, from inception to September 4, 2019. Random-effects models were used. For continuous results, the standardized mean differences (SMDs) and 95% confidence intervals (CIs) were calculated to synthesize the effects. Thirty studies were included, with a total of 2651 patients with schizophrenia. Compared to pharmacotherapy alone and standard care alone, Morita therapy plus pharmacotherapy and Morita therapy plus standard care both had significant effects on mental state (pooled effect size = -1.09, 95% CI: -0.35, -0.83), social functioning (pooled effect size = -0.61, 95% CI: -2.30, -0.92) and behavior (pooled effect size = 1.13, 95% CI: 0.75, 1.51). Significant heterogeneity between studies was found for mental state (I2 = 89%, p < 0.05) and social functioning (I2 = 95%, p < 0.05), but no heterogeneity was found for behavior (I2 = 0%, p = 0.84). Morita therapy has positive effects on mental state and social functioning among patients with schizophrenia, but it leads to some problems with behavior among these patients. Most included studies have unclear bias, and the forest plots show high heterogeneity among the results. Thus, Morita therapy cannot be implemented in clinical practice as a feasible strategy, the conclusion has yet to be confirmed, and new trials and future studies are desired.


Assuntos
Esquizofrenia , Humanos , Esquizofrenia/terapia
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