RESUMEN

The Structural Maintenance of Chromosomes (SMC) protein complexes are DNA-binding molecular machines required to shape chromosomes into functional units and to safeguard the genome through cell division. These ring-shaped multi-subunit protein complexes, which are present in all kingdoms of life, achieve this by organizing chromosomes in three-dimensional space. Mechanistically, the SMC complexes hydrolyze ATP to either stably entrap DNA molecules within their lumen, or rapidly reel DNA into large loops, which allow them to link two stretches of DNA in cis or trans. In this chapter, the canonical structure of the SMC complexes is first introduced, followed by a description of the composition and general functions of the main types of eukaryotic and prokaryotic SMC complexes. Thereafter, the current model for how SMC complexes perform in vitro DNA loop extrusion is presented. Lastly, chromosome loop formation by SMC complexes is introduced, and how the DNA loop extrusion mechanism contributes to chromosome looping by SMC complexes in cells is discussed.

Asunto(s)

Cromosomas , Cromosomas/química , Complejos Multiproteicos/metabolismo , Complejos Multiproteicos/química , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , ADN/química , ADN/metabolismo , ADN/genética , Proteínas Cromosómicas no Histona/metabolismo , Proteínas Cromosómicas no Histona/química , Adenosina Trifosfato/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/química

RESUMEN

Hi-C reads, which represent ligation events between different regions of the genome, must be processed into matrices of interaction frequencies for downstream analysis. Here, I describe a procedure for mapping Hi-C reads to the genome and conversion of mapped reads into the HOMER tag directory format and interaction matrix format for visualization with Juicebox. The method is demonstrated for the mouse composite X chromosome in which reads from the active and inactive X chromosomes are combined after mock DMSO treatment or targeted degradation of cohesin.

Asunto(s)

Cromosoma X , Animales , Cromosoma X/genética , Ratones , Programas Informáticos , Cohesinas , Mapeo Cromosómico/métodos , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas Cromosómicas no Histona/genética , Proteínas Cromosómicas no Histona/metabolismo , Biología Computacional/métodos

RESUMEN

Cohesin is a protein complex that plays a key role in regulating chromosome structure and gene expression. While next-generation sequencing technologies have provided extensive information on various aspects of cohesin, integrating and exploring the vast datasets associated with cohesin are not straightforward. CohesinDB ( https://cohesindb.iqb.u-tokyo.ac.jp ) offers a web-based interface for browsing, searching, analyzing, visualizing, and downloading comprehensive multiomics cohesin information in human cells. In this protocol, we introduce how to utilize CohesinDB to facilitate research on transcriptional regulation and chromatin organization.

Asunto(s)

Proteínas de Ciclo Celular , Proteínas Cromosómicas no Histona , Cohesinas , Navegador Web , Proteínas Cromosómicas no Histona/metabolismo , Proteínas Cromosómicas no Histona/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Humanos , Programas Informáticos , Biología Computacional/métodos , Genómica/métodos , Bases de Datos Genéticas , Cromatina/metabolismo , Cromatina/genética , Internet , Multiómica

RESUMEN

DNA meiotic recombinase 1 (disrupted meiotic cDNA, Dmc1) protein is homologous to the Escherichia coli RecA protein, was first identified in Saccharomyces cerevisiae. This gene has been well studied as an essential role in meiosis in many species. However, studies on the dmc1 gene in reptiles are limited. In this study, a cDNA fragment of 1,111 bp was obtained from the gonadal tissues of the Chinese soft-shell turtle via RT-PCR, containing a 60 bp 3' UTR, a 22 bp 5' UTR, and an ORF of 1,029 bp encoding 342 amino acids, named Psdmc1. Multiple sequence alignments showed that the deduced protein has high similarity (>95 %) to tetrapod Dmc1 proteins, while being slightly lower (86-88 %) to fish species.Phylogenetic tree analysis showed that PsDmc1 was clustered with the other turtles' Dmc1 and close to the reptiles', but far away from the teleost's. RT-PCR and RT-qPCR analyses showed that the Psdmc1 gene was specifically expressed in the gonads, and much higher in testis than the ovary, especially highest in one year-old testis. In situ hybridization results showed that the Psdmc1 was mainly expressed in the perinuclear cytoplasm of primary and secondary spermatocytes, weakly in spermatogonia of the testes. These results indicated that dmc1 would be majorly involved in the developing testis, and play an essential role in the germ cells' meiosis. The findings of this study will provide a basis for further investigations on the mechanisms behind the germ cells' development and differentiation in Chinese soft-shell turtles, even in the reptiles.

Asunto(s)

Gametogénesis , Filogenia , Tortugas , Animales , Tortugas/genética , Tortugas/metabolismo , Masculino , Gametogénesis/genética , Femenino , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Testículo/metabolismo , Clonación Molecular , Secuencia de Aminoácidos , Meiosis/genética , Ovario/metabolismo , Espermatocitos/metabolismo , Pueblos del Este de Asia

RESUMEN

Osteosarcoma (OS) is the most frequent bone malignancy in humans. Previous evidence suggest that circ_0032463 is an oncogenic circular RNA (circRNA) in various cancers, including OS. However, the molecular mechanism of circ_0032463 involved in OS is still unclear. Circ_0032463, microRNA-145-5p (miR-145-5p), GDNF receptor alpha 1 (GFRA1), and Wilms tumor 1-associated protein (WTAP) levels were determined using real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, apoptosis, migration, invasion, and angiogenesis were analyzed using 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell, and tube formation assays. Western blot analysis was performed to measure matrix metalloproteinase 2 (MMP2), MMP9, GFRA1, and WTAP protein levels. Binding between miR-145-5p and circ_0032463 or GFRA1 was confirmed using a dual-luciferase reporter and pull-down assay. The biological role of circ_0032463 on OS cell growth was also analyzed using a xenograft tumor model in vivo. Methylated RNA immunoprecipitation assay validated the interaction between WTAP and circ_0032463. Circ_0032463, GFRA1, and WTAP levels were increased, and miR-145-5p was decreased in OS tissues and cells. Circ_0032463 deficiency might hinder OS cell proliferation, migration, invasion, angiogenesis, and promote apoptosis in vitro. Mechanically, circ_0032463 worked as a miR-145-5p sponge to increase GFRA1 expression. Repression of circ_0032463 knockdown on tumor cell growth was proved in vivo. Besides, N6-methyladenosine (m6A) modification facilitates the biogenesis of circ_0032463. Taken together, m6A-mediated biogenesis of circ_0032463 facilitates OS cell malignant biological behavior partly via regulating the miR-145-5p/GFRA1 axis, suggesting a promising molecular marker for OS treatment.

Asunto(s)

Neoplasias Óseas , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial , MicroARNs , Osteosarcoma , ARN Circular , MicroARNs/genética , MicroARNs/metabolismo , Humanos , Osteosarcoma/genética , Osteosarcoma/patología , Osteosarcoma/metabolismo , ARN Circular/genética , ARN Circular/metabolismo , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial/genética , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial/metabolismo , Animales , Línea Celular Tumoral , Ratones , Neoplasias Óseas/genética , Neoplasias Óseas/metabolismo , Neoplasias Óseas/patología , Regulación Neoplásica de la Expresión Génica , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/metabolismo , Ratones Desnudos , Masculino , Ratones Endogámicos BALB C , Proliferación Celular/genética , Progresión de la Enfermedad , Femenino , ARN Neoplásico/genética , ARN Neoplásico/metabolismo , Adenosina/análogos & derivados , Proteínas de Ciclo Celular

RESUMEN

During embryonic development, Wnt signaling influences both proliferation and sensory formation in the cochlea. How this dual nature of Wnt signaling is coordinated is unknown. In this study, we define a novel role for a Wnt-regulated gene, Mybl2, which was already known to be important for proliferation, in determining the size and patterning of the sensory epithelium in the murine cochlea. Using a quantitative spatial analysis approach and analyzing Mybl2 loss-of-function, we show that Mybl2 promoted proliferation in the inner sulcus domain but limited the size of the sensory domain by influencing their adjoining boundary position via Jag1 regulation during development. Mybl2 loss-of-function simultaneously decreased proliferation in the inner sulcus and increased the size of the sensory domain, resulting in a wider sensory epithelium with ectopic inner hair cell formation during late embryonic stages. These data suggest that progenitor cells in the inner sulcus determine boundary formation and pattern the sensory epithelium via MYBL2.

Asunto(s)

Proliferación Celular , Cóclea , Proteína Jagged-1 , Células Madre , Animales , Cóclea/embriología , Cóclea/citología , Cóclea/metabolismo , Ratones , Epitelio/embriología , Epitelio/metabolismo , Células Madre/citología , Células Madre/metabolismo , Proteína Jagged-1/metabolismo , Proteína Jagged-1/genética , Regulación del Desarrollo de la Expresión Génica , Vía de Señalización Wnt , Tipificación del Cuerpo/genética , Transactivadores/metabolismo , Transactivadores/genética , Células Ciliadas Auditivas Internas/metabolismo , Células Ciliadas Auditivas Internas/citología , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética

RESUMEN

The in vivo three-dimensional genomic architecture of adult mature neurons at homeostasis and after medically relevant perturbations such as axonal injury remains elusive. Here, we address this knowledge gap by mapping the three-dimensional chromatin architecture and gene expression program at homeostasis and after sciatic nerve injury in wild-type and cohesin-deficient mouse sensory dorsal root ganglia neurons via combinatorial Hi-C, promoter-capture Hi-C, CUT&Tag for H3K27ac and RNA-seq. We find that genes involved in axonal regeneration form long-range, complex chromatin loops, and that cohesin is required for the full induction of the regenerative transcriptional program. Importantly, loss of cohesin results in disruption of chromatin architecture and severely impaired nerve regeneration. Complex enhancer-promoter loops are also enriched in the human fetal cortical plate, where the axonal growth potential is highest, and are lost in mature adult neurons. Together, these data provide an original three-dimensional chromatin map of adult sensory neurons in vivo and demonstrate a role for cohesin-dependent long-range promoter interactions in nerve regeneration.

Asunto(s)

Axones , Cromatina , Cohesinas , Regeneración Nerviosa , Regiones Promotoras Genéticas , Células Receptoras Sensoriales , Animales , Células Receptoras Sensoriales/metabolismo , Células Receptoras Sensoriales/fisiología , Ratones , Regiones Promotoras Genéticas/genética , Cromatina/metabolismo , Regeneración Nerviosa/genética , Regeneración Nerviosa/fisiología , Axones/metabolismo , Axones/fisiología , Humanos , Proteínas Cromosómicas no Histona/metabolismo , Proteínas Cromosómicas no Histona/genética , Elementos de Facilitación Genéticos/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Ganglios Espinales/metabolismo , Ganglios Espinales/citología , Nervio Ciático/metabolismo

RESUMEN

Chromatin remodelling complexes (CRC) are ATP-dependent molecular machines important for the dynamic organization of nucleosomes along eukaryotic DNA. CRCs SWI/SNF, RSC and INO80 can move positioned nucleosomes in promoter DNA, leading to nucleosome-depleted regions which facilitate access of general transcription factors. This function is strongly supported by transcriptional activators being able to interact with subunits of various CRCs. In this work we show that SWI/SNF subunits Swi1, Swi2, Snf5 and Snf6 can bind to activation domains of Ino2 required for expression of phospholipid biosynthetic genes in yeast. We identify an activator binding domain (ABD) of ATPase Swi2 and show that this ABD is functionally dispensable, presumably because ABDs of other SWI/SNF subunits can compensate for the loss. In contrast, mutational characterization of the ABD of the Swi2-related ATPase Sth1 revealed that some conserved basic and hydrophobic amino acids within this domain are essential for the function of Sth1. While ABDs of Swi2 and Sth1 define separate functional protein domains, mapping of an ABD within ATPase Ino80 showed co-localization with its HSA domain also required for binding actin-related proteins. Comparative interaction studies finally demonstrated that several unrelated activators each exhibit a specific binding pattern with ABDs of Swi2, Sth1 and Ino80.

Asunto(s)

Adenosina Trifosfatasas , Ensamble y Desensamble de Cromatina , Proteínas de Unión al ADN , Unión Proteica , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Factores de Transcripción , Activación Transcripcional , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Ensamble y Desensamble de Cromatina/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas Cromosómicas no Histona/genética , Proteínas Cromosómicas no Histona/metabolismo , Regulación Fúngica de la Expresión Génica , Dominios Proteicos , Proteínas Nucleares , Proteínas de Ciclo Celular , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico

RESUMEN

Microtubule-based vesicle trafficking usually relies upon kinesin and dynein motors and few reports describe microtubule polymerisation driving directional vesicle trafficking. Here we show that Arabidopsis END BINDING1b (EB1b), a microtubule plus-end binding protein, directly interacts with SYP121, a SNARE protein that mediates the trafficking of the K+ channel KAT1 and its distribution to the plasma membrane (PM) in Arabidopsis guard cells. Knockout of AtEB1b and its homologous proteins results in a modest but significant change in the distribution of KAT1 and SYP121 in guard cells and consequently delays light-induced stomatal opening. Live-cell imaging reveals that a portion of SYP121-associated endomembrane compartments co-localise with AtEB1b at the growing ends of microtubules, trafficking along with the growth of microtubules for targeting to the PM. Our study reveals a mechanism of vesicle trafficking driven by microtubule growth, which is involved in the redistribution of PM proteins to modulate guard cell movement.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Membrana Celular , Proteínas Asociadas a Microtúbulos , Microtúbulos , Estomas de Plantas , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/fisiología , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Microtúbulos/metabolismo , Estomas de Plantas/metabolismo , Estomas de Plantas/fisiología , Membrana Celular/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Transporte de Proteínas , Katanina/metabolismo , Katanina/genética , Movimiento Celular , Proteínas de Ciclo Celular

RESUMEN

Bruton tyrosine kinase inhibitor (BTKi) combined with rituximab-based chemotherapy benefits diffuse large B-cell lymphoma (DLBCL) patients. However, drug resistance is the major cause of relapse and death of DLBCL. In this study, we conducted a comprehensive analysis BTKi-resistance related genes (BRRGs) and established a 10-gene (CARD16, TRIP13, PSRC1, CASP1, PLBD1, CARD6, CAPG, CACNA1A, CDH15, and NDUFA4) signature for early identifying high-risk DLBCL patients. The resistance scores based on the BRRGs signature were associated with prognosis. Furthermore, we developed a nomogram incorporating the BRRGs signature, which demonstrated excellent performance in predicting the prognosis of DLBCL patients. Notably, tumor immune microenvironment, biological pathways, and chemotherapy sensitivity were different between high- and low-resistance score groups. Additionally, we identified TRIP13 as a key gene in our model. TRIP13 was found to be overexpressed in DLBCL and BTKi-resistant DLBCL cell lines, knocking down TRIP13 suppresses cell proliferation, promotes cell apoptosis, and enhances the apoptosis effect of BTKi on DLBCL cells by regulating the Wnt/ß-catenin pathway. In conclusion, our study presents a novel BRRGs signature that could serve as a promising prognostic marker in DLBCL, and TRIP13 might be a potential therapeutic target for resistant DLBCL.

Asunto(s)

Agammaglobulinemia Tirosina Quinasa , Resistencia a Antineoplásicos , Linfoma de Células B Grandes Difuso , Humanos , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Resistencia a Antineoplásicos/genética , Agammaglobulinemia Tirosina Quinasa/antagonistas & inhibidores , Agammaglobulinemia Tirosina Quinasa/genética , Agammaglobulinemia Tirosina Quinasa/metabolismo , Pronóstico , Línea Celular Tumoral , Inhibidores de Proteínas Quinasas/uso terapéutico , Inhibidores de Proteínas Quinasas/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Microambiente Tumoral/genética , Microambiente Tumoral/efectos de los fármacos , Femenino , Masculino , Apoptosis/efectos de los fármacos , Apoptosis/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , ATPasas Asociadas con Actividades Celulares Diversas

RESUMEN

Uterine leiomyosarcoma (uLMS) is the most common type of uterine sarcoma, associated with poor prognosis, high rates of recurrence, and metastasis. Currently, the molecular mechanism of the origin and development of uLMS is limited. Bromodomain and extra-terminal (BET) proteins are involved in both physiological and pathological events. However, the role of BET proteins in the pathogenesis of uLMS is unknown. Here, we show for the first time that BET protein family members, BRD2, BRD3, and BRD4, are aberrantly overexpressed in uLMS tissues compared to the myometrium, with a significant change by histochemical scoring assessment. Furthermore, inhibiting BET proteins with their small, potent inhibitors (JQ1 and I-BET 762) significantly inhibited the uLMS proliferation dose-dependently via cell cycle arrest. Notably, RNA-sequencing analysis revealed that the inhibition of BET proteins with JQ1 and I-BET 762 altered several critical pathways, including the hedgehog pathway, EMT, and transcription factor-driven pathways in uLMS. In addition, the targeted inhibition of BET proteins altered several other epigenetic regulators, including DNA methylases, histone modification, and m6A regulators. The connections between BET proteins and crucial biological pathways provide a fundamental structure to better understand uterine diseases, particularly uLMS pathogenesis. Accordingly, targeting the vulnerable epigenome may provide an additional regulatory mechanism for uterine cancer treatment.

Asunto(s)

Leiomiosarcoma , Factores de Transcripción , Neoplasias Uterinas , Humanos , Femenino , Leiomiosarcoma/metabolismo , Leiomiosarcoma/patología , Leiomiosarcoma/genética , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patología , Neoplasias Uterinas/genética , Factores de Transcripción/metabolismo , Proliferación Celular , Azepinas/farmacología , Regulación Neoplásica de la Expresión Génica , Triazoles/farmacología , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral , Epigénesis Genética , Puntos de Control del Ciclo Celular/efectos de los fármacos , Puntos de Control del Ciclo Celular/genética , Persona de Mediana Edad , Proteínas que Contienen Bromodominio , Benzodiazepinas , Proteínas

RESUMEN

The centromere, a chromosome locus defined by the histone H3-like protein centromeric protein A (CENP-A), promotes assembly of the kinetochore to bind microtubules during cell division. Centromere maintenance requires CENP-A to be actively replenished by dedicated protein machinery in the early G1 phase of the cell cycle to compensate for its dilution after DNA replication. Cyclin-dependent kinases (CDKs) limit CENP-A deposition to once per cell cycle and function as negative regulators outside of early G1. Antithetically, Polo-like kinase 1 (PLK1) promotes CENP-A deposition in early G1, but the molecular details of this process are still unknown. We reveal here a phosphorylation network that recruits PLK1 to the deposition machinery to control a conformational switch required for licensing the CENP-A deposition reaction. Our findings clarify how PLK1 contributes to the epigenetic maintenance of centromeres.

Asunto(s)

Proteínas de Ciclo Celular , Proteína A Centromérica , Centrómero , Proteínas Cromosómicas no Histona , Epigénesis Genética , Quinasa Tipo Polo 1 , Humanos , Proteínas de Ciclo Celular/metabolismo , Centrómero/metabolismo , Proteína A Centromérica/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Fase G1 , Células HeLa , Cinetocoros/metabolismo , Fosforilación , Quinasa Tipo Polo 1/genética , Quinasa Tipo Polo 1/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/genética

RESUMEN

BACKGROUND: Glucose fluctuations may be involved in the pathophysiological process of cardiomyocyte apoptosis, but the exact mechanism remains elusive. This study focused on exploring the mechanisms related to glucose fluctuation-induced cardiomyocyte apoptosis. METHODS: Diabetic rats established via an injection of streptozotocin were randomized to five groups: the controlled diabetic (CD) group, the uncontrolled diabetic (UD) group, the glucose fluctuated diabetic (GFD) group, the GFD group rats with the injection of 0.9% sodium chloride (NaCl) (GFD + NaCl) and the GFD group rats with the injection of N-acetyl-L-cysteine (NAC) (GFD + NAC). Twelve weeks later, cardiac function and apoptosis related protein expressions were tested. Proteomic analysis was performed to further analyze the differential protein expression pattern of CD and GFD. RESULTS: The left ventricular ejection fraction levels and fractional shortening levels were decreased in the GFD group, compared with those in the CD and UD groups. Positive cells tested by DAB-TUNEL were increased in the GFD group, compared with those in the CD group. The expression of Bcl-2 was decreased, but the expressions of Bax, cleaved caspase-3 and cleaved caspase-9 were increased in response to glucose fluctuations. Compared with CD, there were 527 upregulated and 152 downregulated proteins in GFD group. Txnip was one of the differentially expressed proteins related to oxidative stress response. The Txnip expression was increased in the GFD group, while the Akt phosphorylation level was decreased. The interaction between Txnip and Akt was enhanced when blood glucose fluctuated. Moreover, the application of NAC partially reversed glucose fluctuations-induced cardiomyocyte apoptosis. CONCLUSIONS: Glucose fluctuations lead to cardiomyocyte apoptosis by up-regulating Txnip expression and enhancing Txnip-Akt interaction.

Asunto(s)

Proteínas Reguladoras de la Apoptosis , Apoptosis , Glucemia , Proteínas Portadoras , Diabetes Mellitus Experimental , Miocitos Cardíacos , Proteínas Proto-Oncogénicas c-akt , Ratas Sprague-Dawley , Transducción de Señal , Animales , Miocitos Cardíacos/patología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Apoptosis/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Diabetes Mellitus Experimental/metabolismo , Masculino , Proteínas Portadoras/metabolismo , Glucemia/metabolismo , Proteínas Reguladoras de la Apoptosis/metabolismo , Fosforilación , Función Ventricular Izquierda/efectos de los fármacos , Tiorredoxinas/metabolismo , Cardiomiopatías Diabéticas/metabolismo , Cardiomiopatías Diabéticas/patología , Cardiomiopatías Diabéticas/fisiopatología , Cardiomiopatías Diabéticas/etiología , Proteómica , Ratas , Mapas de Interacción de Proteínas , Proteínas de Ciclo Celular

RESUMEN

Hepatitis B virus (HBV) exploits the endosomal sorting complexes required for transport (ESCRT)/multivesicular body (MVB) pathway for virion budding. In addition to enveloped virions, HBV-replicating cells nonlytically release non-enveloped (naked) capsids independent of the integral ESCRT machinery, but the exact secretory mechanism remains elusive. Here, we provide more detailed information about the existence and characteristics of naked capsid, as well as the viral and host regulations of naked capsid egress. HBV capsid/core protein has two highly conserved Lysine residues (K7/K96) that potentially undergo various types of posttranslational modifications for subsequent biological events. Mutagenesis study revealed that the K96 residue is critical for naked capsid egress, and the intracellular egress-competent capsids are associated with ubiquitinated host proteins. Consistent with a previous report, the ESCRT-III-binding protein Alix and its Bro1 domain are required for naked capsid secretion through binding to intracellular capsid, and we further found that the ubiquitinated Alix binds to wild type capsid but not K96R mutant. Moreover, screening of NEDD4 E3 ubiquitin ligase family members revealed that AIP4 stimulates the release of naked capsid, which relies on AIP4 protein integrity and E3 ligase activity. We further demonstrated that AIP4 interacts with Alix and promotes its ubiquitination, and AIP4 is essential for Alix-mediated naked capsid secretion. However, the Bro1 domain of Alix is non-ubiquitinated, indicating that Alix ubiquitination is not absolutely required for AIP4-induced naked capsid secretion. Taken together, our study sheds new light on the mechanism of HBV naked capsid egress in viral life cycle.

Asunto(s)

Cápside , Proteínas de Ciclo Celular , Complejos de Clasificación Endosomal Requeridos para el Transporte , Virus de la Hepatitis B , Ubiquitina-Proteína Ligasas Nedd4 , Ubiquitina-Proteína Ligasas , Ubiquitinación , Liberación del Virus , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Humanos , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Cápside/metabolismo , Virus de la Hepatitis B/metabolismo , Virus de la Hepatitis B/fisiología , Virus de la Hepatitis B/genética , Ubiquitina-Proteína Ligasas Nedd4/metabolismo , Liberación del Virus/fisiología , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Hepatitis B/metabolismo , Hepatitis B/virología , Proteínas de Unión al Calcio

RESUMEN

Thyroid cancer is the most frequently observed endocrine-related malignancy among which anaplastic thyroid cancer (ATC) is the most fatal subtype. The synthesis of protein is active to satisfy the rapid growth of ATC tumor, but the mechanisms regulating protein synthesis are still unknown. Our research revealed that kinetochore protein NUF2 played an essential role in protein synthesis and drove the progression of ATC. The prognosis of patients with thyroid carcinoma was positively correlated with high NUF2 expression. Depletion of NUF2 in ATC cells notably inhibited the proliferation and induced apoptosis, while overexpression of NUF2 facilitated ATC cell viability and colony formation. Deletion of NUF2 significantly suppressed the growth and metastasis of ATC in vivo. Notably, knockdown of NUF2 epigenetically inhibited the expression of magnesium transporters through reducing the abundance of H3K4me3 at promoters, thereby reduced intracellular Mg2+ concentration. Furthermore, we found the deletion of NUF2 or magnesium transporters significantly inhibited the protein synthesis mediated by the PI3K/Akt/mTOR pathway. In conclusion, NUF2 functions as an emerging regulator for protein synthesis by maintaining the homeostasis of intracellular Mg2+, which finally drives ATC progression.

Asunto(s)

Progresión de la Enfermedad , Homeostasis , Magnesio , Carcinoma Anaplásico de Tiroides , Animales , Femenino , Humanos , Ratones , Apoptosis , Proteínas de Transporte de Catión/metabolismo , Proteínas de Transporte de Catión/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Magnesio/metabolismo , Ratones Desnudos , Biosíntesis de Proteínas , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Carcinoma Anaplásico de Tiroides/metabolismo , Carcinoma Anaplásico de Tiroides/patología , Carcinoma Anaplásico de Tiroides/genética , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/metabolismo , Neoplasias de la Tiroides/genética , Serina-Treonina Quinasas TOR/metabolismo

RESUMEN

Purpose: To investigate the neuroplasticity hypothesis of depression by measuring brain-derived neurotrophic factor (BDNF) levels in plasma astrocyte-derived extracellular vesicles (ADEVs) and to evaluate their potential as biomarkers for depression compared with plasma BDNF levels. Patients and Methods: Thirty-five patients with major depressive disorder (MDD) and 35 matched healthy controls (HCs) were enrolled. Plasma ADEVs were isolated using a combination of ultracentrifugation and immunoaffinity capture. Isolated ADEVs were validated using transmission electron microscopy, nanoparticle tracking analysis, and Western blotting. BDNF levels were quantified in both ADEVs and plasma. ALG-2-interacting protein X (Alix) and cluster of differentiation 81 (CD81) levels, two established extracellular vesicle markers, were measured in ADEVs. Results: After false discovery rate correction, patients with MDD exhibited higher CD81 levels (P FDR = 0.040) and lower BDNF levels (P FDR = 0.043) in ADEVs than HCs at baseline. BDNF levels in ADEVs normalized to CD81 (P FDR = 0.002) and Alix (P FDR = 0.040) remained consistent with this finding. Following four weeks of selective serotonin reuptake inhibitor treatment (n=10), CD81 levels in ADEVs decreased (P FDR = 0.046), while BDNF levels normalized to CD81 increased (P FDR = 0.022). BDNF levels in ADEVs were more stable than in plasma. Exploratory analysis revealed no correlation between BDNF levels in ADEVs and plasma (ρ=0.117, P = 0.334). Conclusion: This study provides human in vivo evidence supporting the neuroplasticity hypothesis of depression by demonstrating altered BDNF levels in ADEVs. ADEVs may be more suitable for developing biomarkers of depression than plasma-derived biomarkers.

Asunto(s)

Astrocitos , Biomarcadores , Factor Neurotrófico Derivado del Encéfalo , Trastorno Depresivo Mayor , Vesículas Extracelulares , Plasticidad Neuronal , Humanos , Factor Neurotrófico Derivado del Encéfalo/sangre , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/química , Masculino , Femenino , Plasticidad Neuronal/fisiología , Adulto , Persona de Mediana Edad , Trastorno Depresivo Mayor/sangre , Trastorno Depresivo Mayor/metabolismo , Biomarcadores/sangre , Astrocitos/metabolismo , Tetraspanina 28/metabolismo , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Estudios de Casos y Controles , Proteínas de Unión al Calcio , Proteínas de Ciclo Celular , Complejos de Clasificación Endosomal Requeridos para el Transporte

RESUMEN

PDIA5 is responsible for modification of disulfide bonds of proteins. However, its impact on the malignant progression of glioblastoma multiforme (GBM) remains unknown. We analyzed the expression and prognostic significance of PDIA5 in cohorts of GBM and clinical samples. The PDIA5 protein was significantly overexpressed in GBM tissues, and higher expression of PDIA5 was statistically associated with a worse prognosis in patients with GBM. Transcriptional data from PDIA5 knockdown GBM cells revealed that downstream regulatory genes of PDIA5 were enriched in malignant regulatory pathways and PDIA5 enhanced the proliferative and invasive abilities of GBM cells. By constructing a PDIA5 CXXC motif mutant plasmid, we found CCAR1 was the vital downstream factor of PDIA5 in regulating GBM malignancy in vitro and in vivo. Additionally, RUNX1 bound to the promoter region of PDIA5 and regulated gene transcription, leading to activation of the PDIA5/CCAR1 regulatory axis in GBM. The RUNX1/PDIA5/CCAR1 axis significantly influenced the malignant behavior of GBM cells. In conclusion, this study comprehensively elucidates the crucial role of PDIA5 in the malignant progression of GBM. Downregulating PDIA5 can mitigate the malignant biological behavior of GBM both in vitro and in vivo, potentially improving the efficacy of treatment for clinical patients with GBM.

Asunto(s)

Proteínas Reguladoras de la Apoptosis , Neoplasias Encefálicas , Proteínas de Ciclo Celular , Glioblastoma , Proteína Disulfuro Isomerasas , Animales , Femenino , Humanos , Masculino , Ratones , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Proliferación Celular/genética , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Glioblastoma/metabolismo , Glioblastoma/genética , Glioblastoma/patología , Ratones Desnudos , Proteína Disulfuro Isomerasas/metabolismo , Proteína Disulfuro Isomerasas/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas Reguladoras de la Apoptosis/metabolismo

RESUMEN

OBJECTIVE: To analyze the expression of SPAG5 in gastric cancer tissues and its regulatory roles in gastric cancer cell growth. METHODS: TCGA analysis, immunohistochemistry, and immunofluorescence staining were used to analyze the expression patterns of SPAG5 and MKi67 in gastric cancer and adjacent tissues. In gastric cancer AGS and MGC803 cells, the effects of lentivirus-mediated SPAG5 knockdown on cell growth and apoptosis were evaluated using Celigo, MTT, clone formation assays and flow cytometry. RESULTS: Proteinatlas and TCGA database analysis suggested that SPAG5 was highly expressed in gastric cancer, and Kaplan-Meier analysis and GEPIA analysis showed high expressions of SPAG 5 in lung adenocarcinoma, breast cancer, hepatocellular carcinoma, pancreatic carcinoma, cervical cancer and bladder carcinoma. Immunohistochemistry revealed that SPAG5 was highly expressed in gastric cancer tissues (P < 0.001), and immunofluorescence colocalization analysis demonstrated a significant correlation between SPAG5 and MKI67 (R=0.393, P < 0.001). RT-qPCR and Western blotting showed that SPAG5 was highly expressed in MKN74, BGC823, MGC803, SGC7901 and AGS cells. In AGS and MGC803 cells, SPAG5 knockdown significantly inhibited proliferation and promoted apoptosis. CONCLUSIONS: The expressions of SPAG5 and MKi67 are correlated in gastric cancer tissues, and SPAG5 knockdown inhibits the proliferation of gastric cancer cells. SPAG5 is associated with the prognosis of gastric cancer patients and may serve as a promising biomarker for gastric cancer.

Asunto(s)

Apoptosis , Proliferación Celular , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patología , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Línea Celular Tumoral , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Antígeno Ki-67/metabolismo

RESUMEN

The lymphatic system consists of a vessel network lined by specialized lymphatic endothelial cells (LECs) that are responsible for tissue fluid homeostasis and immune cell trafficking. The mechanisms for organ-specific LEC responses to environmental cues are not well understood. We found robust lymphangiogenesis during influenza A virus infection in the adult mouse lung. We show that the number of LECs increases twofold at 7 days post-influenza infection (dpi) and threefold at 21 dpi, and that lymphangiogenesis is preceded by lymphatic dilation. We also show that the expanded lymphatic network enhances fluid drainage to mediastinal lymph nodes. Using EdU labeling, we found that a significantly higher number of pulmonary LECs are proliferating at 7 dpi compared to LECs in homeostatic conditions. Lineage tracing during influenza indicates that new pulmonary LECs are derived from preexisting LECs rather than non-LEC progenitors. Lastly, using a conditional LEC-specific YAP/TAZ knockout model, we established that lymphangiogenesis, fluid transport and the immune response to influenza are independent of YAP/TAZ activity in LECs. These findings were unexpected, as they indicate that YAP/TAZ signaling is not crucial for these processes.

Asunto(s)

Proteínas Adaptadoras Transductoras de Señales , Células Endoteliales , Pulmón , Linfangiogénesis , Infecciones por Orthomyxoviridae , Proteínas Señalizadoras YAP , Animales , Proteínas Señalizadoras YAP/metabolismo , Células Endoteliales/metabolismo , Ratones , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Pulmón/metabolismo , Pulmón/patología , Infecciones por Orthomyxoviridae/metabolismo , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/patología , Virus de la Influenza A/fisiología , Vasos Linfáticos/metabolismo , Vasos Linfáticos/patología , Ratones Noqueados , Transducción de Señal , Proliferación Celular , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Ratones Endogámicos C57BL , Factores de Transcripción/metabolismo , Factores de Transcripción/genética

RESUMEN

N6-methyladenosine (m6A) methylation, as a new regulatory mechanism, has been reported to be involved in diverse biological processes in recent years. Wilms tumor 1-associated protein (WTAP), as the key member of m6A methylation, has been proven to participate in tumorigenesis. Here, we studied the expression of WTAP and its potential mechanism involved in the development of esophageal squamous cell carcinoma (ESCC). We detected the expression of WTAP and its correlation with clinicopathological features, and we determined the function of WTAP on ESCC cells by MTS assay, colony formation, scratch wound healing assay, Transwell assay, and subcutaneous xenograft assay. We used mRNA sequencing technology to screen candidate downstream targets for WTAP and investigated the underlying mechanism of CCND1 in ESCC promotion through a series of rescue assays. An elevated expression of WTAP in ESCC malignancy indicated a worse prognosis. WTAP promoted the proliferation and metastasis of ESCC cells, and CCND1 was identified as the potential downstream effecter of WTAP. Moreover, WTAP modulated ESCC progression through a MAPK pathway-dependent pattern. Our research suggested that WTAP promoted both proliferation and metastasis of ESCC by accelerating the expression of CCND1 via the MAPK signaling pathway, indicating that WTAP may be a candidate prognostic biomarker for ESCC and also will be a promising strategy for ESCC cancer therapy.

Asunto(s)

Proliferación Celular , Ciclina D1 , Progresión de la Enfermedad , Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Sistema de Señalización de MAP Quinasas , Humanos , Ciclina D1/metabolismo , Ciclina D1/genética , Carcinoma de Células Escamosas de Esófago/patología , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas de Esófago/metabolismo , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Animales , Línea Celular Tumoral , Ratones , Masculino , Regulación Neoplásica de la Expresión Génica , Pronóstico , Femenino , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/metabolismo , Movimiento Celular , Ratones Desnudos , Persona de Mediana Edad , Proteínas de Ciclo Celular