Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 817
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 183(1): 143-157.e13, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32877699

RESUMO

Humoral responses in coronavirus disease 2019 (COVID-19) are often of limited durability, as seen with other human coronavirus epidemics. To address the underlying etiology, we examined post mortem thoracic lymph nodes and spleens in acute SARS-CoV-2 infection and observed the absence of germinal centers and a striking reduction in Bcl-6+ germinal center B cells but preservation of AID+ B cells. Absence of germinal centers correlated with an early specific block in Bcl-6+ TFH cell differentiation together with an increase in T-bet+ TH1 cells and aberrant extra-follicular TNF-α accumulation. Parallel peripheral blood studies revealed loss of transitional and follicular B cells in severe disease and accumulation of SARS-CoV-2-specific "disease-related" B cell populations. These data identify defective Bcl-6+ TFH cell generation and dysregulated humoral immune induction early in COVID-19 disease, providing a mechanistic explanation for the limited durability of antibody responses in coronavirus infections, and suggest that achieving herd immunity through natural infection may be difficult.


Assuntos
Infecções por Coronavirus/imunologia , Centro Germinativo/imunologia , Pneumonia Viral/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Idoso , Idoso de 80 Anos ou mais , Linfócitos B/imunologia , COVID-19 , Feminino , Centro Germinativo/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Baço/imunologia , Baço/patologia , Fator de Necrose Tumoral alfa/metabolismo
2.
Nature ; 614(7946): 75-80, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36725995

RESUMO

Time-periodic light field has emerged as a control knob for manipulating quantum states in solid-state materials1-3, cold atoms4 and photonic systems5 through hybridization with photon-dressed Floquet states6 in the strong-coupling limit, dubbed Floquet engineering. Such interaction leads to tailored properties of quantum materials7-11, for example, modifications of the topological properties of Dirac materials12,13 and modulation of the optical response14-16. Despite extensive research interests over the past decade3,8,17-20, there is no experimental evidence of momentum-resolved Floquet band engineering of semiconductors, which is a crucial step to extend Floquet engineering to a wide range of solid-state materials. Here, on the basis of time and angle-resolved photoemission spectroscopy measurements, we report experimental signatures of Floquet band engineering in a model semiconductor, black phosphorus. On near-resonance pumping at a photon energy of 340-440 meV, a strong band renormalization is observed near the band edges. In particular, light-induced dynamical gap opening is resolved at the resonance points, which emerges simultaneously with the Floquet sidebands. Moreover, the band renormalization shows a strong selection rule favouring pump polarization along the armchair direction, suggesting pseudospin selectivity for the Floquetband engineering as enforced by the lattice symmetry. Our work demonstrates pseudospin-selective Floquet band engineering in black phosphorus and provides important guiding principles for Floquet engineering of semiconductors.

3.
Mol Cell ; 69(6): 1028-1038.e6, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29547716

RESUMO

N6-methyladenosine (m6A) is an abundant modification in eukaryotic mRNA, regulating mRNA dynamics by influencing mRNA stability, splicing, export, and translation. However, the precise m6A regulating machinery still remains incompletely understood. Here we demonstrate that ZC3H13, a zinc-finger protein, plays an important role in modulating RNA m6A methylation in the nucleus. We show that knockdown of Zc3h13 in mouse embryonic stem cell significantly decreases global m6A level on mRNA. Upon Zc3h13 knockdown, a great majority of WTAP, Virilizer, and Hakai translocate to the cytoplasm, suggesting that Zc3h13 is required for nuclear localization of the Zc3h13-WTAP-Virilizer-Hakai complex, which is important for RNA m6A methylation. Finally, Zc3h13 depletion, as does WTAP, Virilizer, or Hakai, impairs self-renewal and triggers mESC differentiation. Taken together, our findings demonstrate that Zc3h13 plays a critical role in anchoring WTAP, Virilizer, and Hakai in the nucleus to facilitate m6A methylation and to regulate mESC self-renewal.


Assuntos
Adenosina/análogos & derivados , Núcleo Celular/metabolismo , Proliferação de Células , Autorrenovação Celular , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas Nucleares/metabolismo , Processamento Pós-Transcricional do RNA , RNA Mensageiro/metabolismo , Regiões 3' não Traduzidas , Transporte Ativo do Núcleo Celular , Adenosina/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular , Diferenciação Celular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Humanos , Metilação , Camundongos , Proteínas Nucleares/genética , Fatores de Processamento de RNA , Estabilidade de RNA , RNA Mensageiro/genética , Proteínas de Ligação a RNA , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
4.
Proc Natl Acad Sci U S A ; 120(50): e2220496120, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38064514

RESUMO

Massive GGGGCC (G4C2) repeat expansion in C9orf72 and the resulting loss of C9orf72 function are the key features of ~50% of inherited amyotrophic lateral sclerosis and frontotemporal dementia cases. However, the biological function of C9orf72 remains unclear. We previously found that C9orf72 can form a stable GTPase activating protein (GAP) complex with SMCR8 (Smith-Magenis chromosome region 8). Herein, we report that the C9orf72-SMCR8 complex is a major negative regulator of primary ciliogenesis, abnormalities in which lead to ciliopathies. Mechanistically, the C9orf72-SMCR8 complex suppresses the primary cilium as a RAB8A GAP. Moreover, based on biochemical analysis, we found that C9orf72 is the RAB8A binding subunit and that SMCR8 is the GAP subunit in the complex. We further found that the C9orf72-SMCR8 complex suppressed the primary cilium in multiple tissues from mice, including but not limited to the brain, kidney, and spleen. Importantly, cells with C9orf72 or SMCR8 knocked out were more sensitive to hedgehog signaling. These results reveal the unexpected impact of C9orf72 on primary ciliogenesis and elucidate the pathogenesis of diseases caused by the loss of C9orf72 function.


Assuntos
Esclerose Lateral Amiotrófica , Proteína C9orf72 , Cílios , Demência Frontotemporal , Animais , Camundongos , Esclerose Lateral Amiotrófica/metabolismo , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Cílios/metabolismo , Expansão das Repetições de DNA , Demência Frontotemporal/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Humanos , Células HEK293
5.
Proc Natl Acad Sci U S A ; 119(25): e2201761119, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35709319

RESUMO

The BABY BOOM (BBM) AINTEGUMENTA-LIKE (AIL) AP2/ERF domain transcription factor is a major regulator of plant cell totipotency, as it induces asexual embryo formation when ectopically expressed. Surprisingly, only limited information is available on the role of BBM during zygotic embryogenesis. Here we reexamined BBM expression and function in the model plant Arabidopsis thaliana (Arabidopsis) using reporter analysis and newly developed CRISPR mutants. BBM was expressed in the embryo from the zygote stage and also in the maternal (nucellus) and filial (endosperm) seed tissues. Analysis of CRISPR mutant alleles for BBM (bbm-cr) and the redundantly acting AIL gene PLETHORA2 (PLT2) (plt2-cr) uncovered individual roles for these genes in the timing of embryo progression. We also identified redundant roles for BBM and PLT2 in endosperm proliferation and cellularization and the maintenance of zygotic embryo development. Finally, we show that ectopic BBM expression in the egg cell of Arabidopsis and the dicot crops Brassica napus and Solanum lycopersicon is sufficient to bypass the fertilization requirement for embryo development. Together these results highlight roles for BBM and PLT2 in seed development and demonstrate the utility of BBM genes for engineering asexual embryo development in dicot species.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Endosperma , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassica napus/genética , Brassica napus/crescimento & desenvolvimento , Endosperma/genética , Endosperma/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Solanum lycopersicum/genética , Solanum lycopersicum/crescimento & desenvolvimento , Sementes/genética , Sementes/crescimento & desenvolvimento , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
6.
Nano Lett ; 24(1): 261-269, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38113224

RESUMO

2D Dion-Jacobson (DJ) perovskites have emerged as promising photovoltaic materials, but the insulating organic spacer has hindered the efficient charge transport. Herein, we successfully synthesized a terthiophene-based semiconductor spacer, namely, 3ThDMA, for 2D DJ perovskite. An interesting finding is that the energy levels of 3ThDMA extensively overlap with the inorganic components and directly contribute to the band formation of (3ThDMA)PbI4, leading to enhanced charge transport across the organic spacer layers, whereas no such orbital interactions were found in (UDA)PbI4, a DJ perovskite based on 1,11-undecanediaminum (UDA). The devices based on (3ThDMA)MAn-1PbnI3n+1 (nominal n = 5) obtained a champion efficiency of 15.25%, which is a record efficiency for 2D DJ perovskite solar cells using long-conjugated spacers (conjugated rings ≥ 3) and a 22.60% efficiency for 3ThDMA-treated 3D PSCs. Our findings provide an important insight into understanding the orbital interactions in 2D DJ perovskite using an organic semiconductor spacer for efficient solar cells.

7.
Nano Lett ; 24(25): 7716-7723, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38848111

RESUMO

Mixed-dimensional heterostructures integrate materials of diverse dimensions with unique electronic functionalities, providing a new platform for research in electron transport and optoelectronic detection. Here, we report a novel covalently bonded one-dimensional/two-dimensional (1D/2D) homojunction structure with robust junction contacts, which exhibits wide-spectrum (from the visible to near-infrared regions), self-driven photodetection, and polarization-sensitive photodetection capabilities. Benefiting from the ultralow dark current at zero bias voltage, the on/off ratio and detectivity of the device reach 1.5 × 103 and 3.24 × 109 Jones, respectively. Furthermore, the pronounced anisotropy of the WSe2 1D/2D homojunction is attributed to its low symmetry, enabling polarization-sensitive detection. In the absence of any external bias voltage, the device exhibits strong linear dichroism for wavelengths of 638 and 808 nm, with anisotropy ratios of 2.06 and 1.96, respectively. These results indicate that such mixed-dimensional structures can serve as attractive building blocks for novel optoelectronic detectors.

8.
J Am Chem Soc ; 146(5): 3363-3372, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38265366

RESUMO

Inverted organic solar cells (OSCs) have attracted much attention because of their outstanding stability, with zinc oxide (ZnO) being commonly used as the electron transport layer (ETL). However, both surface defects and the photocatalytic effect of ZnO could lead to serious photodegradation of acceptor materials. This, in turn, hampers the improvement of the efficiency and stability in OSCs. Herein, we developed a multiarmed aromatic ammonium salt, namely, benzene-1,3,5-triyltrimethanaminium bromide (PhTMABr), for modifying ZnO. This compound possesses mild weak acidity aimed at removing the residual amines present within ZnO film. In addition, the PhTMABr could also passivate surface defects of ZnO through multiple hydrogen-bonding interactions between its terminal amino groups and the oxygen anion of ZnO, leading to a better interface contact, which effectively enhances charge transport. As a result, an efficiency of 18.75% was achieved based on the modified ETL compared to the bare ZnO (PCE = 17.34%). The devices utilizing the modified ZnO retained 87% and 90% of their initial PCE after thermal stress aging at 65 °C for 1500 h and continuous 1-sun illumination with maximum power point (MPP) tracking for 1780 h, respectively. Importantly, the extrapolated T80 lifetime with MPP tracking exceeds 10 000 h. The new class of materials employed in this work to modify the ZnO ETL should pave the way for enhancing the efficiency and stability of OSCs, potentially advancing their commercialization process.

9.
J Am Chem Soc ; 146(20): 14287-14296, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38718348

RESUMO

PEDOT: PSS has been widely used as a hole extraction layer (HEL) in organic solar cells (OSCs). However, their acidic nature can potentially corrode the indium tin oxide (ITO) electrode over time, leading to adverse effects on the longevity of the OSCs. Herein, we have developed a class of biphosphonic acid molecules with tunable dipole moments for self-assembled monolayers (SAMs), namely, 3-BPIC(i), 3-BPIC, and 3-BPIC-F, which exhibit an increasing dipole moment in sequence. Compared to centrosymmetric 3-BPIC(i), the axisymmetric 3-BPIC and 3-BPIC-F exhibit higher adsorption energies (Eads) with ITO, shorter interface spacing, more uniform coverage on ITO surface, and better interfacial compatibility with the active layer. Thanks to the incorporation of fluorine atoms, 3-BPIC-F exhibits a deeper highest occupied molecular orbital (HOMO) energy level and a larger dipole moment compared to 3-BPIC, resulting in an enlarged work function (WF) for the ITO/3-BPIC-F substrate. These advantages of 3-BPIC-F could not only improve hole extraction within the device but also lower the interfacial impedance and reduce nonradiative recombination at the interface. As a result, the OSCs using SAM based on 3-BPIC-F obtained a record high efficiency of 19.71%, which is higher than that achieved from the cells based on 3-BPIC(i) (13.54%) and 3-BPIC (19.34%). Importantly, 3-BPIC-F-based OSCs exhibit significantly enhanced stability compared to that utilizing PEDOT:PSS as HEL. Our work offers guidance for the future design of functional molecules for SAMs to realize even higher performance in organic solar cells.

10.
J Am Chem Soc ; 146(9): 6189-6198, 2024 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-38386630

RESUMO

Polyketides with the isochroman-3-one pharmacophore are rare among fungal natural products as their biosynthesis requires an unorthodox S-type aromatic ring cyclization. Genome mining uncovered a conserved gene cluster in select leotiomycetous fungi that encodes the biosynthesis of cytosporones, including isochroman-3-one congeners. Combinatorial biosynthesis in total biosynthetic and biocatalytic formats in Saccharomyces cerevisiae and in vitro reconstitution of key reactions with purified enzymes revealed how cytosporone structural and bioactivity diversity is generated. The S-type acyl dihydroxyphenylacetic acid (ADA) core of cytosporones is assembled by a collaborating polyketide synthase pair. Thioesterase domain-catalyzed transesterification releases ADA esters, some of which are known Nur77 modulators. Alternatively, hydrolytic release allows C6 hydroxylation by a flavin-dependent monooxygenase, yielding a trihydroxybenzene moiety. Reduction of the C9 carbonyl by a short chain dehydrogenase/reductase initiates isochroman-3-one formation, affording cytosporones with cytotoxic and antimicrobial activity. Enoyl di- or trihydroxyphenylacetic acids are generated as shunt products, while isocroman-3,4-diones are formed by autoxidation. The cytosporone pathway offers novel polyketide biosynthetic enzymes for combinatorial synthetic biology to advance the production of "unnatural" natural products for drug discovery.


Assuntos
Produtos Biológicos , Policetídeos , Fungos/genética , Saccharomyces cerevisiae/metabolismo , Policetídeo Sintases/metabolismo , Policetídeos/química , Produtos Biológicos/metabolismo
11.
Small ; 20(10): e2305131, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37875640

RESUMO

Protein drugs hold promise in treating multiple complex diseases, including cancer. The priority of protein drug application is precise delivery of substantial bioactive protein into tumor site. Metal-organic-framework (MOF) is widely considered as a promising carrier to encapsulate protein drug owing to the noncovalent interaction between carrier and protein. However, limited loading efficiency and potential toxicity of metal ion in MOF restrict its application in clinical research. Herein, a tumor targeted collagenase-encapsulating MOF via protein-metal ion-organic ligand coordination (PMOCol ) for refining deep tissue pancreatic cancer photoimmunotherapy is developed. By an expedient method in which the ratio of metal ion, histidine residues of protein and ligand is precisely controlled, PMOCol is constructed with ultrahigh encapsulation efficiency (80.3 wt%) and can release collagenase with high enzymatic activity for tumor extracellular matrix (ECM) regulation after reaching tumor microenvironment (TME). Moreover, PMOcol exhibits intensively poorer toxicity than the zeolitic imidazolate framework-8 biomineralized protein. After treatment, the pancreatic tumor with abundant ECM shows enhanced immunocyte infiltration owing to extracellular matrix degradation that improves suppressive TME. By integrating hyperthermia agent with strong near-infrared absorption (1064 nm), PMOCol can induce acute immunogenicity to host immunity activation and systemic immune memory production to prevent tumor development and recurrence.


Assuntos
Estruturas Metalorgânicas , Neoplasias Pancreáticas , Humanos , Estruturas Metalorgânicas/química , Ligantes , Proteínas , Neoplasias Pancreáticas/terapia , Colagenases , Microambiente Tumoral
12.
J Transl Med ; 22(1): 543, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844930

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is a common malignant tumor, and glutamine is vital for tumor cells. The role of glutamine transporter SLC1A5 in tumor progression and transarterial chemoembolization (TACE) efficacy is under study. This research seeks to determine the impact of SLC1A5 expression on the prognosis and TACE efficacy of HCC and elucidate its mechanisms. METHODS: SLC1A5 expression in HCC, correlation with patient outcomes, and response to TACE were studied in an open access liver cancer dataset and confirmed in our cohort. Additionally, the correlation between SLC1A5 expression and hypoxia, angiogenesis and immune infiltration was analyzed and verified by immunohistochemistry, immunofluorescence and transcriptome sequencing. Liver cancer cell lines with SLC1A5 expression knockdown or overexpression were constructed, and cell proliferation, colony formation, apoptosis, migration and drug sensitivity as well as in vivo xenograft tumor were measured. A gene set enrichment analysis was conducted to determine the signaling pathway influenced by SLC1A5, and a western blot analysis was performed to detect protein expression alterations. RESULTS: SLC1A5 expression was higher in HCC tissue and associated with poor survival and TACE resistance. Hypoxia could stimulate the upregulation of glutamine transport, angiogenesis and SLC1A5 expression. The SLC1A5 expression was positively correlated with hypoxia and angiogenesis-related genes, immune checkpoint pathways, macrophage, Tregs, and other immunosuppressive cells infiltration. Knockdown of SLC1A5 decreased proliferation, colony formation, and migration, but increased apoptosis and increased sensitivity to chemotherapy drugs. Downregulation of SLC1A5 resulted in a decrease in Vimentin and N-cadherin expression, yet an increase in E-cadherin expression. Upregulation of SLC1A5 increased Vimentin and N-cadherin expression, while decreasing E-cadherin. Overexpression of ß-catenin in SLC1A5-knockdown HCC cell lines could augment Vimentin and N-cadherin expression, suppress E-cadherin expression, and increase the migration and drug resistance. CONCLUSIONS: Elevated SLC1A5 was linked to TACE resistance and survival shortening in HCC patients. SLC1A5 was positively correlated with hypoxia, angiogenesis, and immunosuppression. SLC1A5 may mediate HCC cell migration and drug resistance via Epithelial-mesenchymal transition (EMT) pathway.


Assuntos
Sistema ASC de Transporte de Aminoácidos , Carcinoma Hepatocelular , Quimioembolização Terapêutica , Resistencia a Medicamentos Antineoplásicos , Neoplasias Hepáticas , Antígenos de Histocompatibilidade Menor , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/irrigação sanguínea , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Sistema ASC de Transporte de Aminoácidos/metabolismo , Sistema ASC de Transporte de Aminoácidos/genética , Animais , Linhagem Celular Tumoral , Prognóstico , Masculino , Feminino , Antígenos de Histocompatibilidade Menor/metabolismo , Antígenos de Histocompatibilidade Menor/genética , Regulação Neoplásica da Expressão Gênica , Pessoa de Meia-Idade , Camundongos Nus , Proliferação de Células , Movimento Celular , Apoptose , Camundongos , Camundongos Endogâmicos BALB C , Regulação para Cima/genética
13.
Plant Physiol ; 192(2): 1483-1497, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-36810650

RESUMO

Glandular secretory trichomes (GSTs) can secrete and store a variety of specific metabolites. By increasing GST density, valuable metabolites can be enhanced in terms of productivity. However, the comprehensive and detailed regulatory network of GST initiation still needs further investigation. By screening a complementary DNA library derived from young leaves of Artemisia annua, we identified a MADS-box transcription factor, AaSEPALLATA1 (AaSEP1), that positively regulates GST initiation. Overexpression of AaSEP1 in A. annua substantially increased GST density and artemisinin content. The HOMEODOMAIN PROTEIN 1 (AaHD1)-AaMYB16 regulatory network regulates GST initiation via the jasmonate (JA) signaling pathway. In this study, AaSEP1 enhanced the function of AaHD1 activation on downstream GST initiation gene GLANDULAR TRICHOME-SPECIFIC WRKY 2 (AaGSW2) through interaction with AaMYB16. Moreover, AaSEP1 interacted with the JA ZIM-domain 8 (AaJAZ8) and served as an important factor in JA-mediated GST initiation. We also found that AaSEP1 interacted with CONSTITUTIVE PHOTOMORPHOGENIC 1 (AaCOP1), a major repressor of light signaling. In this study, we identified a MADS-box transcription factor that is induced by JA and light signaling and that promotes the initiation of GST in A. annua.


Assuntos
Artemisia annua , Tricomas , Tricomas/genética , Tricomas/metabolismo , Artemisia annua/genética , Artemisia annua/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ciclopentanos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
14.
Opt Lett ; 49(4): 891-894, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38359209

RESUMO

A high-power all-fiber radially polarized laser system is demonstrated, in which an integrated nanograting mode convertor (S-wave plate) is used for the generation of radially polarized beam. Experimentally, a 1-W radially polarized beam was used as the seed laser, whose mode purity and mode extinction ratio (MER) were 96.5% and 98.3%, respectively. A single-stage few-mode fiber amplifier was employed to boost the 1-W seed laser to an average power of 113.2 W, when the pump power was 160 W. The corresponding slope efficiency and beam quality factor (M2) were approximately 72% and 2.3%, respectively. Moreover, the mode purity and MER of the amplified radially polarized laser were measured to be 95.7% and 97%, respectively. To the best of our knowledge, this is the highest output power from an all-fiber radially polarized laser system without obvious degradations of the mode purity and MER.

15.
FASEB J ; 37(7): e23057, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37367700

RESUMO

Heterotopic ossification occurs as a pathological ossification condition characterized by ectopic bone formation within soft tissues following trauma. Vascularization has long been established to fuel skeletal ossification during tissue development and regeneration. However, the feasibility of vascularization as a target of heterotopic ossification prevention remained to be further clarified. Here, we aimed to identify whether verteporfin as a widely used FDA-approved anti-vascularization drug could effectively inhibit trauma-induced heterotopic ossification formation. In the current study, we found that verteporfin not only dose dependently inhibited the angiogenic activity of human umbilical vein endothelial cells (HUVECs) but also the osteogenic differentiation of tendon stem cells (TDSCs). Moreover, YAP/ß-catenin signaling axis was downregulated by the verteporfin. Application of lithium chloride, an agonist of ß-catenin, recovered TDSCs osteogenesis and HUVECs angiogenesis that was inhibited by verteporfin. In vivo, verteporfin attenuated heterotopic ossification formation by decelerating osteogenesis and the vessels densely associated with osteoprogenitors formation, which could also be readily reversed by lithium chloride, as revealed by histological analysis and Micro-CT scan in a murine burn/tenotomy model. Collectively, this study confirmed the therapeutic effect of verteporfin on angiogenesis and osteogenesis in trauma-induced heterotopic ossification. Our study sheds light on the anti-vascularization strategy with verteporfin as a candidate treatment for heterotopic ossification prevention.


Assuntos
Tendão do Calcâneo , Ossificação Heterotópica , Camundongos , Humanos , Animais , Osteogênese , Tendão do Calcâneo/patologia , Verteporfina/farmacologia , beta Catenina , Células Endoteliais/patologia , Cloreto de Lítio/farmacologia , Ossificação Heterotópica/tratamento farmacológico , Ossificação Heterotópica/etiologia , Ossificação Heterotópica/prevenção & controle
16.
EMBO Rep ; 23(11): e54853, 2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36129789

RESUMO

Cohesin regulates sister chromatid cohesion but also contributes to chromosome folding by promoting the formation of chromatin loops, a process mediated by loop extrusion. Although PDS5 regulates cohesin dynamics on chromatin, the exact function of PDS5 in cohesin-mediated chromatin looping remains unclear. Two paralogs of PDS5 exist in vertebrates, PDS5A and PDS5B. Here we show that PDS5A and PDS5B co-localize with RAD21 and CTCF at loop anchors. Rapid PDS5A or PDS5B degradation in liver cancer cells using an inducible degron system reduces chromatin loops and increases loop size. RAD21 enrichment at loop anchors is decreased upon depletion of PDS5A or PDS5B. PDS5B loss also reduces CTCF signals at loop anchors and has a stronger effect on loop enlargement compared with PDS5A. Co-depletion of PDS5A and PDS5B reduces RAD21 levels at loop anchors although the amount of cohesin on chromatin is increased. Our study provides insight into how PDS5 proteins regulate cohesin-mediated chromatin looping.


Assuntos
Proteínas de Ciclo Celular , Proteínas Cromossômicas não Histona , Animais , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ciclo Celular/metabolismo , Cromossomos/genética , Cromossomos/metabolismo , Cromatina/genética , Mamíferos/genética , Mamíferos/metabolismo , Coesinas
17.
Inorg Chem ; 63(12): 5365-5377, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38466201

RESUMO

Herein, Bi3+/Mn4+ doped Ca2LaTaO6 phosphors with a double-perovskite structure were successfully synthesized with solid-state reaction at high temperature. The photoluminescence (PL) performances were investigated in detail. The blue radiation (∼465 nm) from the Bi3+ ion and the red radiation (∼686 nm) originating from the Mn4+ ion were obtained under 313 nm excitation. Especially, the pathway of energy transfer (Bi3+ → Mn4+) contributes to enhance the red emission intensity (Mn4+: ∼686 nm) in Ca2LaTaO6:Bi3+/Mn4+ system. The PL mechanism of Ca2LaTaO6:Bi3+/Mn4+ was analyzed through luminescence lifetimes and PL spectra. Moreover, the emitting bands of Ca2LaTaO6:Bi3+/Mn4+ were primarily matched with the absorbing bands of carotenoids and phytochrome PFR on behalf of plant growth, so the phosphors were suitable for the design of a plant growth light under near-ultraviolet to blue excitation. At last, the optical temperature dependent performances of the Ca2LaTaO6:Bi3+/Mn4+ were analyzed with luminescence intensity ratio technology. The sample has presented excellent temperature measuring relative sensitivity (SR = 2.106% K-1). The results illustrated that the Ca2LaTaO6:Bi3+/Mn4+ phosphor also can be used to develop an optical temperature sensor.

18.
J Immunol ; 209(7): 1401-1413, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36038289

RESUMO

Myeloid-derived suppressor cells (MDSCs) are pathologically activated neutrophils and monocytes with potent immunosuppressive activity that regulate immune responses in the tumor microenvironment. We identified a novel long noncoding RNA (lncRNA), named as lnc57Rik, in the MDSCs that controls their immunosuppressive functions. Lnc57Rik was induced in in vitro and in vivo inflammatory settings and upregulated the genes related to MDSC-mediated immunosuppression, including Arg-1, NOS2, NOX2, and COX2 Furthermore, Lnc57Rik can not only bind with the C/EBPß isoform liver-enriched activator protein to activate C/EBPß but also with the methyltransferase WD repeat-containing protein 5 that enables the enrichment of histone H3 trimethylated lysine 4 marks on the promoter regions of Arg-1, NOS2, NOX2, and COX2, eventually resulting in their transcriptional activation. Furthermore, the conserved human lnc57Rik has a similar function as murine lnc57Rik Taken together, upregulation of lnc57Rik in the tumor microenvironment promotes the immunosuppressive function of MDSCs.


Assuntos
Células Supressoras Mieloides , Neoplasias , RNA Longo não Codificante , Animais , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Histonas/metabolismo , Humanos , Lisina/metabolismo , Metiltransferases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Microambiente Tumoral/genética
19.
Bioorg Chem ; 143: 107017, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38056388

RESUMO

Eleven new amides, four racemic pairs of (±)-chlorahupetamides A, B, D, E (1, 2, 4, 5) and chlorahupetamides C, F, G (3, 6, 7), have been isolated from Chloranthus henryi var. hupehensis. Compounds 1-3 are the first naturally occurring dimers via an unprecedented [2 + 2] cycloaddition derived from two dissimilar cinnamic acid amides, while compounds 4 and 5 represent the first examples of lignanamides in Chloranthus; together with two new hydroxycinnamic acid amide monomers (6-7), these compounds were obtained. Their structures were characterized by nuclear magnetic resonance (NMR), electronic circular dichroism (ECD), and X-ray diffraction analysis. Meanwhile, an LPS-induced BV-2 cell inflammatory model was used to determine the potential anti-inflammatory activity of all the isolated compounds. Intriguingly, compound -1 treatment showed a much greater inhibition of TNF-α expression with an EC50 value of 1.80 µM, while compound + 1 had more advantages in reducing IL-1ß expression with an EC50 value of 19.93 µM. Moreover, compounds + 1 and -1 could significantly suppress inflammation and inhibit the Akt signaling pathway by decreasing the phosphorylated protein levels of Akt.


Assuntos
Anti-Inflamatórios , Proteínas Proto-Oncogênicas c-akt , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosforilação , Anti-Inflamatórios/farmacologia , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Estrutura Molecular
20.
Bioorg Chem ; 147: 107420, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38718461

RESUMO

Phytochemical analysis of Chloranthus henryi var. hupehensis roots led to the identification of a new eudesmane sesquiterpenoid dimer, 18 new sesquiterpenoids, and three known sesquiterpenoids. Among the isolates, 1 was a rare sesquiterpenoid dimer that is assembled by a unique oxygen bridge (C11-O-C8') of two highly rearranged eudesmane-type sesquiterpenes with the undescribed C16 carbon framework. (+)-2 and (-)-2 were a pair of new skeleton dinorsesquiterpenoids with a remarkable 6/6/5 tricyclic ring framework including one γ-lactone ring and the bicyclo[3.3.1]nonane core. Their structures were elucidated using spectroscopic data, single-crystal X-ray diffraction analysis, and quantum chemical computations. In the LPS-induced BV-2 microglial cell model, 17 suppressed IL-1ß and TNF-α expression with EC50 values of 6.81 and 2.76 µM, respectively, indicating its excellent efficacy in inhibiting inflammatory factors production in a dose dependent manner and without cytotoxicity. In subsequent mechanism studies, compounds 3, 16, and 17 could reduce IL-1ß and TNF-α production by inhibiting IKBα/p65 pathway activation.


Assuntos
Relação Dose-Resposta a Droga , Raízes de Plantas , Sesquiterpenos , Transdução de Sinais , Sesquiterpenos/farmacologia , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Raízes de Plantas/química , Transdução de Sinais/efeitos dos fármacos , Estrutura Molecular , Camundongos , Animais , Relação Estrutura-Atividade , Fator de Transcrição RelA/metabolismo , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Descoberta de Drogas , Inibidor de NF-kappaB alfa/metabolismo , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA