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1.
Cell ; 184(21): 5465-5481.e16, 2021 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-34582787

RESUMO

In vivo cell fate conversions have emerged as potential regeneration-based therapeutics for injury and disease. Recent studies reported that ectopic expression or knockdown of certain factors can convert resident astrocytes into functional neurons with high efficiency, region specificity, and precise connectivity. However, using stringent lineage tracing in the mouse brain, we show that the presumed astrocyte-converted neurons are actually endogenous neurons. AAV-mediated co-expression of NEUROD1 and a reporter specifically and efficiently induces reporter-labeled neurons. However, these neurons cannot be traced retrospectively to quiescent or reactive astrocytes using lineage-mapping strategies. Instead, through a retrograde labeling approach, our results reveal that endogenous neurons are the source for these viral-reporter-labeled neurons. Similarly, despite efficient knockdown of PTBP1 in vivo, genetically traced resident astrocytes were not converted into neurons. Together, our results highlight the requirement of lineage-tracing strategies, which should be broadly applied to studies of cell fate conversions in vivo.


Assuntos
Astrócitos/citologia , Diferenciação Celular , Linhagem da Célula , Neurônios/citologia , Animais , Astrócitos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Encéfalo/patologia , Lesões Encefálicas/patologia , Linhagem Celular Tumoral , Reprogramação Celular , Dependovirus/metabolismo , Regulação para Baixo , Regulação da Expressão Gênica , Genes Reporter , Proteína Glial Fibrilar Ácida/genética , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Proteínas de Homeodomínio/metabolismo , Humanos , Integrases/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/metabolismo , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/metabolismo
2.
Nat Immunol ; 21(11): 1470, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32939095

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

3.
Nat Immunol ; 21(5): 546-554, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32231300

RESUMO

High-dose radiation activates caspases in tumor cells to produce abundant DNA fragments for DNA sensing in antigen-presenting cells, but the intrinsic DNA sensing in tumor cells after radiation is rather limited. Here we demonstrate that irradiated tumor cells hijack caspase 9 signaling to suppress intrinsic DNA sensing. Instead of apoptotic genomic DNA, tumor-derived mitochondrial DNA triggers intrinsic DNA sensing. Specifically, loss of mitochondrial DNA sensing in Casp9-/- tumors abolishes the enhanced therapeutic effect of radiation. We demonstrated that combining emricasan, a pan-caspase inhibitor, with radiation generates synergistic therapeutic effects. Moreover, loss of CASP9 signaling in tumor cells led to adaptive resistance by upregulating programmed death-ligand 1 (PD-L1) and resulted in tumor relapse. Additional anti-PD-L1 blockade can further overcome this acquired immune resistance. Therefore, combining radiation with a caspase inhibitor and anti-PD-L1 can effectively control tumors by sequentially blocking both intrinsic and extrinsic inhibitory signaling.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Caspase 9/metabolismo , Inibidores de Caspase/uso terapêutico , Quimiorradioterapia/métodos , Neoplasias Colorretais/terapia , Ácidos Pentanoicos/uso terapêutico , Animais , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Caspase 9/genética , Linhagem Celular Tumoral , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transplante de Neoplasias , Transdução de Sinais , Regulação para Cima
4.
Annu Rev Neurosci ; 46: 1-15, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-36750409

RESUMO

A holy grail of regenerative medicine is to replenish the cells that are lost due to disease. The adult mammalian central nervous system (CNS) has, however, largely lost such a regenerative ability. An emerging strategy for the generation of new neurons is through glia-to-neuron (GtN) conversion in vivo, mainly accomplished by the regulation of fate-determining factors. When inhibited, PTBP1, a factor involved in RNA biology, was reported to induce rapid and efficient GtN conversion in multiple regions of the adult CNS. Remarkably, PTBP1 inhibition was also claimed to greatly improve behaviors of mice with neurological diseases or aging. These phenomenal claims, if confirmed, would constitute a significant advancement in regenerative medicine. Unfortunately, neither GtN conversion nor therapeutic potential via PTBP1 inhibition was validated by the results of multiple subsequent replication studies with stringent methods. Here we review these controversial studies and conclude with recommendations for examining GtN conversion in vivo and future investigations of PTBP1.


Assuntos
Neuroglia , Neurônios , Animais , Camundongos , Neurônios/fisiologia , Sistema Nervoso Central , Retina , Mamíferos
5.
Nat Methods ; 19(11): 1419-1426, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36280718

RESUMO

Structured illumination microscopy (SIM) doubles the spatial resolution of a fluorescence microscope without requiring high laser powers or specialized fluorophores. However, the excitation of out-of-focus fluorescence can accelerate photobleaching and phototoxicity. In contrast, light-sheet fluorescence microscopy (LSFM) largely avoids exciting out-of-focus fluorescence, thereby enabling volumetric imaging with low photobleaching and intrinsic optical sectioning. Combining SIM with LSFM would enable gentle three-dimensional (3D) imaging at doubled resolution. However, multiple orientations of the illumination pattern, which are needed for isotropic resolution doubling in SIM, are challenging to implement in a light-sheet format. Here we show that multidirectional structured illumination can be implemented in oblique plane microscopy, an LSFM technique that uses a single objective for excitation and detection, in a straightforward manner. We demonstrate isotropic lateral resolution below 150 nm, combined with lower phototoxicity compared to traditional SIM systems and volumetric acquisition speed exceeding 1 Hz.


Assuntos
Imageamento Tridimensional , Iluminação , Imageamento Tridimensional/métodos , Microscopia de Fluorescência/métodos , Fotodegradação
6.
Plant Cell ; 34(5): 2038-2055, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35188198

RESUMO

In tomato (Solanum lycopersicum) and other plants, the photoreceptor UV-RESISTANCE LOCUS 8 regulates plant UV-B photomorphogenesis by modulating the transcription of many genes, the majority of which depends on the transcription factor ELONGATED HYPOCOTYL 5 (HY5). HY5 transcription is induced and then rapidly attenuated by UV-B. However, neither the transcription factors that activate HY5 transcription nor the mechanism for its attenuation during UV-B signaling is known. Here, we report that the tomato B-BOX (BBX) transcription factors SlBBX20 and SlBBX21 interact with SlHY5 and bind to the SlHY5 promoter to activate its transcription. UV-B-induced SlHY5 expression and SlHY5-controlled UV-B responses are normal in slbbx20 and slbbx21 single mutants, but strongly compromised in the slbbx20 slbbx21 double mutant. Surprisingly, UV-B responses are also compromised in lines overexpressing SlBBX20 or SlBBX21. Both SlHY5 and SlBBX20 bind to G-box1 in the SlHY5 promoter. SlHY5 outcompetes SlBBX20 for binding to the SlHY5 promoter in vitro, and inhibits the association of SlBBX20 with the SlHY5 promoter in vivo. Overexpressing 35S:SlHY5-FLAG in the WT background inhibits UV-B-induced endogenous SlHY5 expression. Together, our results reveal the critical role of the SlBBX20/21-SlHY5 module in activating the expression of SlHY5, the gene product of which inhibits its own gene transcription under UV-B, forming an autoregulatory negative feedback loop that balances SlHY5 transcription in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Solanum lycopersicum , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Retroalimentação , Regulação da Expressão Gênica de Plantas/genética , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Fatores de Transcrição/metabolismo , Raios Ultravioleta
7.
Proc Natl Acad Sci U S A ; 119(11): e2107339119, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35254903

RESUMO

SignificanceOutside the neurogenic niches, the adult brain lacks multipotent progenitor cells. In this study, we performed a series of in vivo screens and reveal that a single factor can induce resident brain astrocytes to become induced neural progenitor cells (iNPCs), which then generate neurons, astrocytes, and oligodendrocytes. Such a conclusion is supported by single-cell RNA sequencing and multiple lineage-tracing experiments. Our discovery of iNPCs is fundamentally important for regenerative medicine since neural injuries or degeneration often lead to loss/dysfunction of all three neural lineages. Our findings also provide insights into cell plasticity in the adult mammalian brain, which has largely lost the regenerative capacity.


Assuntos
Astrócitos/citologia , Astrócitos/metabolismo , Diferenciação Celular , Linhagem da Célula , Reprogramação Celular , Corpo Estriado/citologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular/genética , Linhagem da Célula/genética , Reprogramação Celular/genética , Corpo Estriado/metabolismo , Imunofluorescência , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Expressão Gênica , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Genes Reporter , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Camundongos , Células-Tronco Multipotentes/citologia , Células-Tronco Multipotentes/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurogênese , RNA-Seq , Receptores Notch/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
8.
Biol Chem ; 405(2): 91-104, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-36942505

RESUMO

Glycoprotein (GP) Ib-IX-V is the second most abundant platelet receptor for thrombin and other ligands crucial for hemostasis and thrombosis. Its activity is involved in platelet adhesion to vascular injury sites and thrombin-induced platelet aggregation. GPIb-IX-V is a heteromeric complex composed of four subunits, GPIbα, GPIbß, GPV and GPIX, in a stoichiometric ratio that has been wildly debated. Despite its important physiological roles, the overall structure and molecular arrangement of GPIb-IX-V are not yet fully understood. Here, we purify stable and functional human GPIb-IX-V complex from reconstituted EXPi293F cells in high homogeneity, and perform biochemical and structural characterization of this complex. Single-particle cryo-electron microscopy structure of GPIb-IX-V is determined at ∼11 Å resolution, which unveils the architecture of GPIb-IX-V and its subunit organization. Size-exclusion chromatography-multi-angle static light scattering analysis reveals that GPIb-IX-V contains GPIb-IX and GPV at a 1:1 stoichiometric ratio and surface plasmon resonance assays show that association of GPV leads to slow kinetics of thrombin binding to GPIb-IX-V. Taken together, our results provide the first three-dimensional architecture of the intact GPIb-IX-V complex, which extends our understanding of the structure and functional mechanism of this complex in hemostasis and thrombosis.


Assuntos
Complexo Glicoproteico GPIb-IX de Plaquetas , Trombose , Humanos , Complexo Glicoproteico GPIb-IX de Plaquetas/química , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Trombina/metabolismo , Microscopia Crioeletrônica , Plaquetas/metabolismo , Trombose/metabolismo
9.
Am J Kidney Dis ; 81(2): 240-244, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35970429

RESUMO

Focal segmental glomerulosclerosis (FSGS) is a histological lesion with a variety of potential causes, including rare variants of podocyte-related genes. Recently, it has been found that variants in the TBC1D8B gene on the X chromosome can lead to early-onset focal segmental glomerulosclerosis and steroid-resistant nephrotic syndrome by affecting endocytosis and recycling of nephrin. Here, we report a 19-year-old Chinese patient with nephrotic syndrome and normal kidney function. He had a complete remission of nephrotic syndrome after full-dose prednisone and cyclosporine treatment. Unfortunately, a relapse of nephrotic syndrome occurred during prednisone tapering. Focal segmental glomerulosclerosis was proven by a kidney biopsy, and a hemizygous pathogenic variant located in the TBC (Tre-2-Bub2-Cdc16) domain of TBC1D8B was detected by whole-exome sequencing. By comparing our case with reports of other patients with TBC1D8B variants, we suggest possible genotype-phenotype correlations. To our knowledge, this is the first report identifying a pathogenetic variant in the TBC domain of TBC1D8B in an adult-onset focal segmental glomerulosclerosis patient with steroid-dependent NS. With this report, we broaden the clinical and genetic spectrum of X-linked genetic FSGS.


Assuntos
Glomerulosclerose Segmentar e Focal , Síndrome Nefrótica , Podócitos , Masculino , Humanos , Síndrome Nefrótica/tratamento farmacológico , Síndrome Nefrótica/genética , Glomerulosclerose Segmentar e Focal/tratamento farmacológico , Glomerulosclerose Segmentar e Focal/genética , Prednisona/uso terapêutico , Ciclosporina/uso terapêutico , Podócitos/patologia
10.
Plant Physiol ; 189(2): 527-540, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35312008

RESUMO

The transcription factor ELONGATED HYPOCOTYL5 (HY5) plays critical roles in plant photomorphogenesis. Previous studies on HY5 have mainly focused on the seedling stage in Arabidopsis (Arabidopsis thaliana), and its functions in other plant species have not been well characterized, particularly at adult stages of development. In this report, we investigated the functions of tomato (Solanum lycopersicum) HY5 (SlHY5) from seedlings to adult plants with a focus on fruits. Genome-edited slhy5 mutants exhibited typical compromised photomorphogenesis in response to various light conditions. The slhy5 mutants showed reduced primary root length and secondary root number, which is associated with altered auxin signaling. SlHY5 promoted chlorophyll biosynthesis from seedling to adult stages. Notably, the promotive role of SlHY5 on chlorophyll accumulation was more pronounced on the illuminated side of green fruits than on their shaded side. Consistent with this light-dependent effect, we determined that SlHY5 protein is stabilized by light. Transcriptome and metabolome analyses in fruits revealed that SlHY5 has major functions in the regulation of metabolism, including the biosynthesis of phenylpropanoids and steroidal glycoalkaloids. These data demonstrate that SlHY5 performs both shared and distinct functions in relation to its Arabidopsis counterpart. The manipulation of SlHY5 represents a powerful tool to influence the two vital agricultural traits of seedling fitness and fruit quality in tomato.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Solanum lycopersicum , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Clorofila/metabolismo , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Luz , Solanum lycopersicum/metabolismo , Desenvolvimento Vegetal , Plântula/metabolismo
11.
Exp Eye Res ; 236: 109668, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37774963

RESUMO

BACKGROUND: Investigation of biomarkers may facilitate understanding the mechanisms of primary open-angle glaucoma (POAG) and developing therapeutic targets. This study aimed to identify potential genes based on competing endogenous RNA (ceRNA) network for POAG. METHODS: Based on long noncoding RNAs (lncRNAs), microRNAs (miRNAs) and messenger RNAs (mRNAs) from the Gene Expression Omnibus (GEO) database, we identified differential expressed lncRNAs (DELs), differential expressed miRNAs (DEMis) and differential expressed mRNAs (DEMs) and then constructed a ceRNA network. Through weighted gene co-expression network analysis (WGCNA), we identified gender-specific genes for gender-associated ceRNA network construction, followed by the protein-protein interaction (PPI) network and functional enrichment analysis to screen hub genes and reveal their functions. The expression levels of hub genes were measured in steroid-induced ocular hypertension (SIOH) mice. RESULTS: A total of 175 DELs, 727 DEMs and 45 DEMis were screened between control and POAG samples. Seven modules were identified through WGCNA and one module was associated with gender of POAG patients. We discovered 41 gender-specific genes for gender-associated ceRNA construction and then identified 8 genes (NAV3, C1QB, RXRB, P2RY4, ADAM15, VAV3, ZNF207 and TOP1), which were enriched in cell cycle-related pathways and immune-related pathways. C1QB, RXRB, Top1 and ZNF207 were highly interacted with other proteins. The expression levels of NAV3 and C1QB were downregulated in SIOH, while the levels of RXRB, P2RY4, ADAM15, VAV3, ZNF207 and TOP1 were upregulated in SIOH. CONCLUSION: This study identifies hub genes associated with the pathogenesis of gender-specific POAG and provides potential biomarkers for POAG.


Assuntos
Glaucoma de Ângulo Aberto , MicroRNAs , RNA Longo não Codificante , Humanos , Camundongos , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , Glaucoma de Ângulo Aberto/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Redes Reguladoras de Genes , Biomarcadores Tumorais/genética , Proteínas de Membrana/genética , Proteínas ADAM/genética , Proteínas Associadas aos Microtúbulos/genética
12.
Surg Endosc ; 37(7): 5094-5100, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36920575

RESUMO

Magnifying endoscopy is advantageous in detecting precancerous lesions. Our study aimed to clarify its ability to detect easily missed neoplastic lesions on the upper gastrointestinal tract. A retrospective analysis of clinical, endoscopic, and pathological data of cases undergoing gastroscopy was performed using magnifying and routine endoscopy. The detection rates of overall lesions, the ability to identify flat-type neoplastic lesions, and the easily missed neoplastic lesions were compared between the two groups. Endoscopic data from 32,367 patients was analyzed in this study. The use of magnifying endoscopy was an independent factor in identifying flat lesions (OR 2.236, 95% CI 1.969-2.540, p < 0.001), particularly type IIb lesions (OR 3.117, 95% CI 2.333-4.165, p < 0.001). For neoplastic lesions, magnifying endoscopy was also identified as having better sensitivity than routine endoscopy (sensitivity, 90.4% vs. 78.9%, p < 0.001). Similarly, magnifying endoscopy was an independent factor for identifying flat lesions (OR 2.927, 95% CI 2.365-3.621, p < 0.001), especially type IIc lesions (OR 4.415, 95% CI 3.076-6.339, p < 0.001). Magnifying endoscopy was also identified as having superior sensitivity (44.7% vs. 13.3%, p = 0.034) for early cancerous lesions. Compared to routine endoscopy, magnification endoscopy is advantageous in detecting and identifying neoplastic lesions in the upper gastrointestinal tract, especially flat neoplastic lesions and early cancers.


Assuntos
Neoplasias Gástricas , Trato Gastrointestinal Superior , Humanos , Estudos Retrospectivos , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/patologia , Endoscopia Gastrointestinal , Gastroscopia , Trato Gastrointestinal Superior/diagnóstico por imagem
13.
Proc Natl Acad Sci U S A ; 117(11): 5782-5790, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32123087

RESUMO

Transfer RNAs (tRNAs) are products of RNA polymerase III (Pol III) and essential for mRNA translation and ultimately cell growth and proliferation. Whether and how individual tRNA genes are specifically regulated is not clear. Here, we report that SOX4, a well-known Pol II-dependent transcription factor that is critical for neurogenesis and reprogramming of somatic cells, also directly controls, unexpectedly, the expression of a subset of tRNA genes and therefore protein synthesis and proliferation of human glioblastoma cells. Genome-wide location analysis through chromatin immunoprecipitation-sequencing uncovers specific targeting of SOX4 to a subset of tRNA genes, including those for tRNAiMet Mechanistically, sequence-specific SOX4-binding impedes the recruitment of TATA box binding protein and Pol III to tRNA genes and thereby represses their expression. CRISPR/Cas9-mediated down-regulation of tRNAiMet greatly inhibits growth and proliferation of human glioblastoma cells. Conversely, ectopic tRNAiMet partially rescues SOX4-mediated repression of cell proliferation. Together, these results uncover a regulatory mode of individual tRNA genes to control cell behavior. Such regulation may coordinate codon usage and translation efficiency to meet the demands of diverse tissues and cell types, including cancer cells.


Assuntos
Neoplasias Encefálicas/metabolismo , Proliferação de Células , Glioblastoma/metabolismo , RNA de Transferência/metabolismo , Fatores de Transcrição SOXC/metabolismo , Linhagem Celular Tumoral , DNA Polimerase III/metabolismo , Células HEK293 , Humanos , RNA de Transferência/genética , Fatores de Transcrição SOXC/genética , Proteína de Ligação a TATA-Box/genética , Proteína de Ligação a TATA-Box/metabolismo
14.
J Labelled Comp Radiopharm ; 66(3): 108-115, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36794560

RESUMO

We report the synthesis and biological evaluation of 131 I-labeled antihuman tumor-derived immunoglobulin G (IgG) light chain monoclonal antibody (4E9) ([131 I]I-4E9) as a promising probe for tumor imaging. [131 I]I-4E9 was synthesized in radiochemical yield of 89.9 ± 4.7% with radiochemical purity of more than 99%. [131 I]I-4E9 showed high stability in normal saline and human serum. In cell uptake studies, [131 I]I-4E9 exhibited favorable binding affinity and high specificity in HeLa MR cells. In biodistribution studies, [131 I]I-4E9 showed high tumor uptake, high tumor/non-tumor ratios, and specific binding in BALB/c nu/nu mice bearing human HeLa MR xenografts. Single-photon emission computerized tomography (SPECT) imaging of [131 I]I-4E9 in the HeLa MR xenograft model demonstrated clear visualization of tumor after 48 h and confirmed specific binding in tumor. These findings suggest that [131 I]I-4E9 possesses favorable biological characteristics and warrants further investigation as a prospective probe for imaging and treatment of cancers.


Assuntos
Anticorpos Monoclonais , Neoplasias , Animais , Camundongos , Humanos , Camundongos Nus , Radioisótopos do Iodo , Cadeias Leves de Imunoglobulina/metabolismo , Imunoglobulina G , Distribuição Tecidual , Estudos Prospectivos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Linhagem Celular Tumoral
15.
Genes Dev ; 29(4): 440-50, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25691470

RESUMO

The orphan nuclear receptor TLX regulates neural stem cell self-renewal in the adult brain and functions primarily as a transcription repressor through recruitment of Atrophin corepressors, which bind to TLX via a conserved peptide motif termed the Atro box. Here we report crystal structures of the human and insect TLX ligand-binding domain in complex with Atro box peptides. In these structures, TLX adopts an autorepressed conformation in which its helix H12 occupies the coactivator-binding groove. Unexpectedly, H12 in this autorepressed conformation forms a novel binding pocket with residues from helix H3 that accommodates a short helix formed by the conserved ALXXLXXY motif of the Atro box. Mutations that weaken the TLX-Atrophin interaction compromise the repressive activity of TLX, demonstrating that this interaction is required for Atrophin to confer repressor activity to TLX. Moreover, the autorepressed conformation is conserved in the repressor class of orphan nuclear receptors, and mutations of corresponding residues in other members of this class of receptors diminish their repressor activities. Together, our results establish the functional conservation of the autorepressed conformation and define a key sequence motif in the Atro box that is essential for TLX-mediated repression.


Assuntos
Drosophila melanogaster/química , Modelos Moleculares , Receptores Nucleares Órfãos/química , Receptores Citoplasmáticos e Nucleares/química , Animais , Cristalização , Proteínas de Drosophila/química , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Células HEK293 , Humanos , Receptores Nucleares Órfãos/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo
16.
Int J Mol Sci ; 24(20)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37894803

RESUMO

As an important hormone response gene, Gretchen Hagen 3 (GH3) maintains hormonal homeostasis by conjugating excess auxin with amino acids during plant stress-related signaling pathways. GH3 genes have been characterized in many plant species, but they are rarely reported in potato. Here, 19 StGH3 genes were isolated and characterized. Phylogenetic analysis indicated that StGH3s were divided into two categories (group I and group III). Analyses of gene structure and motif composition showed that the members of a specific StGH3 subfamily are relatively conserved. Collinearity analysis of StGH3 genes in potato and other plants laid a foundation for further exploring the evolutionary characteristics of the StGH3 genes. Promoter analysis showed that most StGH3 promoters contained hormone and abiotic stress response elements. Multiple transcriptome studies indicated that some StGH3 genes were responsive to ABA, water deficits, and salt treatments. Moreover, qRT-PCR analysis indicated that StGH3 genes could be induced by phytohormones (ABA, SA, and MeJA) and abiotic stresses (water deficit, high salt, and low temperature), although with different patterns. Furthermore, transgenic tobacco with transient overexpression of the StGH3.3 gene showed positive regulation in response to water deficits by increasing proline accumulation and reducing the leaf water loss rate. These results suggested that StGH3 genes may be involved in the response to abiotic stress through hormonal signal pathways. Overall, this study provides useful insights into the evolution and function of StGH3s and lays a foundation for further study on the molecular mechanisms of StGH3s in the regulation of potato drought resistance.


Assuntos
Solanum tuberosum , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Filogenia , Secas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Cloreto de Sódio/farmacologia , Água/metabolismo , Hormônios , Regulação da Expressão Gênica de Plantas
17.
Int J Mol Sci ; 24(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36674521

RESUMO

Sucrose non-ferment 1-related protein kinase 2 (SnRK2) is a highly conserved protein kinase in plants that plays an important role in regulating plant response to drought stress. Although it has been reported in some plants, the evolutionary relationship of potato SnRK2s and their function in drought resistance have not been systematically analyzed. In this study, molecular characteristic analysis showed that 8 StSnRK2s were distributed on six chromosomes, coding proteins were divided into three subgroups, and StSnRK2s clustered in the same subgroup had similar conserved motifs and domains. In addition, StSnRK2 has a wide range of replication events in some species, making it closer to dicots in the process of evolution. In addition, the average nonsynonymous substitution rate/synonymous substitution rate (Ka/Ks) value of SnRK2s in monocots was higher than that of dicots. The codon usage index showed that SnRK2s prefer to use cytosine 3 (C3s), guanine 3 (G3s) and GC content (GC3s) in monocots, whereas thymine 3 (T3s) and adenine 3 (A3s) are preferred in dicots. Furthermore, stress response analysis showed that the expression of StSnRK2s under different degrees of drought stress significantly correlated with one or more stress-related physiological indices, such as proline and malondialdehyde (MDA) content, superoxide dismutase (SOD) and catalase (CAT) activity, ion leakage (IL) etc. The drought resistance of StSnRK2 transgenic plants was determined to occur in the order of StSnRK2.1/2.8 > StSnRK2.2/2.5 > StSnRK2.4/2.6 > StSnRK2.3 > StSnRK2.7, was attributed to not only lower IL but also higher proline, soluble sugar contents and stress-related genes in transgenic plants compared to wild type (WT). In conclusion, this study provides useful insights into the evolution and function of StSnRK2s and lays a foundation for further study on the molecular mechanism of StSnRK2s regulating potato drought resistance.


Assuntos
Resistência à Seca , Proteínas de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nicotiana/metabolismo , Secas , Proteínas Quinases/metabolismo , Antioxidantes , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Prolina/metabolismo , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico/genética
18.
J Neurosci ; 41(9): 2024-2038, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33468570

RESUMO

DYT1 dystonia is a hereditary neurologic movement disorder characterized by uncontrollable muscle contractions. It is caused by a heterozygous mutation in Torsin A (TOR1A), a gene encoding a membrane-embedded ATPase. While animal models provide insights into disease mechanisms, significant species-dependent differences exist since animals with the identical heterozygous mutation fail to show pathology. Here, we model DYT1 by using human patient-specific cholinergic motor neurons (MNs) that are generated through either direct conversion of patients' skin fibroblasts or differentiation of induced pluripotent stem cells (iPSCs). These human MNs with the heterozygous TOR1A mutation show reduced neurite length and branches, markedly thickened nuclear lamina, disrupted nuclear morphology, and impaired nucleocytoplasmic transport (NCT) of mRNAs and proteins, whereas they lack the perinuclear "blebs" that are often observed in animal models. Furthermore, we uncover that the nuclear lamina protein LMNB1 is upregulated in DYT1 cells and exhibits abnormal subcellular distribution in a cholinergic MNs-specific manner. Such dysregulation of LMNB1 can be recapitulated by either ectopic expression of the mutant TOR1A gene or shRNA-mediated downregulation of endogenous TOR1A in healthy control MNs. Interestingly, downregulation of LMNB1 can largely ameliorate all the cellular defects in DYT1 MNs. These results reveal the value of disease modeling with human patient-specific neurons and indicate that dysregulation of LMNB1, a crucial component of the nuclear lamina, may constitute a major molecular mechanism underlying DYT1 pathology.SIGNIFICANCE STATEMENT Inaccessibility to patient neurons greatly impedes our understanding of the pathologic mechanisms for dystonia. In this study, we employ reprogrammed human patient-specific motor neurons (MNs) to model DYT1, the most severe hereditary form of dystonia. Our results reveal disease-dependent deficits in nuclear morphology and nucleocytoplasmic transport (NCT). Most importantly, we further identify LMNB1 dysregulation as a major contributor to these deficits, uncovering a new pathologic mechanism for DYT1 dystonia.


Assuntos
Técnicas de Reprogramação Celular/métodos , Distonia Muscular Deformante/metabolismo , Lamina Tipo B/metabolismo , Neurônios Motores/metabolismo , Adolescente , Adulto , Técnicas de Cultura de Células/métodos , Diferenciação Celular/fisiologia , Células Cultivadas , Distonia Muscular Deformante/genética , Feminino , Fibroblastos , Humanos , Células-Tronco Pluripotentes Induzidas , Masculino , Pessoa de Meia-Idade , Chaperonas Moleculares/genética , Neurônios Motores/patologia , Células-Tronco Neurais , Adulto Jovem
19.
J Cell Mol Med ; 26(2): 354-363, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34894202

RESUMO

Stress is one of the leading causes of male infertility, but its exact function in testosterone synthesis has scarcely been reported. We found that adult male rats show a decrease in bodyweight, genital index and serum testosterone level after continual chronic stress for 21 days. Two-dimensional gel electrophoresis (2-DE) and MALDI-TOF-MS analysis identified 10 differentially expressed proteins in stressed rats compared with controls. A strong protein interaction network was found to be centred on Atp5a1 among these proteins. Atp5a1 expression significantly decreased in Leydig cells after chronic stress. Transfection of Atp5a1 siRNAs decreased StAR, CYP11A1, and 17ß-HSD expression by damaging the structure of mitochondria in TM3 cells. This study confirmed that chronic stress plays an important role in testosterone synthesis by regulating Atp5a1 expression in Leydig cells.


Assuntos
Células Intersticiais do Testículo , Testosterona , Animais , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Células Intersticiais do Testículo/metabolismo , Masculino , Mitocôndrias/metabolismo , ATPases Mitocondriais Próton-Translocadoras , Ratos
20.
Glia ; 70(2): 273-286, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34643969

RESUMO

In response to brain injury, resident astrocytes become reactive and play dynamic roles in neural repair and regeneration. The signaling pathways underlying such reactive astrogliosis remain largely unclear. We here show that NEK6, a NIMA-related serine/threonine protein kinase, is rapidly induced following pathological stimulations and plays critical roles in reactive astrogliosis. Enhanced NEK6 expression promotes reactive astrogliosis and exacerbates brain lesions; and conversely, NEK6 downregulation dampens injury-induced astrocyte reactivity and reduces lesion size. Mechanistically, NEK6 associates with and phosphorylates STAT3. Kinase activity of NEK6 is required for induction of GFAP and PCNA, markers of reactive astrogliosis. Interestingly, NEK6 is also localized in the nucleus and binds to STAT3-responsive genomic elements in astrocytes. These results indicate that NEK6 constitutes a molecular target for the regulation of reactive astrogliosis.


Assuntos
Astrócitos , Gliose , Quinases Relacionadas a NIMA , Fator de Transcrição STAT3 , Astrócitos/metabolismo , Lesões Encefálicas , Proteína Glial Fibrilar Ácida , Gliose/patologia , Humanos , Quinases Relacionadas a NIMA/genética , Quinases Relacionadas a NIMA/metabolismo , Fosforilação , Antígeno Nuclear de Célula em Proliferação , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais
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