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1.
Nature ; 634(8035): 986-994, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39358506

RESUMO

Mutation of tet methylcytosine dioxygenase 2 (encoded by TET2) drives myeloid malignancy initiation and progression1-3. TET2 deficiency is known to cause a globally opened chromatin state and activation of genes contributing to aberrant haematopoietic stem cell self-renewal4,5. However, the open chromatin observed in TET2-deficient mouse embryonic stem cells, leukaemic cells and haematopoietic stem and progenitor cells5 is inconsistent with the designated role of DNA 5-methylcytosine oxidation of TET2. Here we show that chromatin-associated retrotransposon RNA 5-methylcytosine (m5C) can be recognized by the methyl-CpG-binding-domain protein MBD6, which guides deubiquitination of nearby monoubiquitinated Lys119 of histone H2A (H2AK119ub) to promote an open chromatin state. TET2 oxidizes m5C and antagonizes this MBD6-dependent H2AK119ub deubiquitination. TET2 depletion thereby leads to globally decreased H2AK119ub, more open chromatin and increased transcription in stem cells. TET2-mutant human leukaemia becomes dependent on this gene activation pathway, with MBD6 depletion selectively blocking proliferation of TET2-mutant leukaemic cells and largely reversing the haematopoiesis defects caused by Tet2 loss in mouse models. Together, our findings reveal a chromatin regulation pathway by TET2 through retrotransposon RNA m5C oxidation and identify the downstream MBD6 protein as a feasible target for developing therapies specific against TET2 mutant malignancies.


Assuntos
5-Metilcitosina , Cromatina , Proteínas de Ligação a DNA , Dioxigenases , Histonas , Oxirredução , Proteínas Proto-Oncogênicas , Ubiquitinação , Dioxigenases/metabolismo , Animais , Camundongos , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/deficiência , Cromatina/metabolismo , Humanos , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas/deficiência , Histonas/metabolismo , 5-Metilcitosina/metabolismo , Leucemia/metabolismo , Leucemia/genética , Leucemia/patologia , Retroelementos/genética , Hematopoese , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinogênese/patologia , RNA/metabolismo , RNA/genética , Feminino , Proliferação de Células , Mutação , Masculino
2.
Mol Cell ; 82(4): 833-851.e11, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35180428

RESUMO

HOTTIP lncRNA is highly expressed in acute myeloid leukemia (AML) driven by MLL rearrangements or NPM1 mutations to mediate HOXA topologically associated domain (TAD) formation and drive aberrant transcription. However, the mechanism through which HOTTIP accesses CCCTC-binding factor (CTCF) chromatin boundaries and regulates CTCF-mediated genome topology remains unknown. Here, we show that HOTTIP directly interacts with and regulates a fraction of CTCF-binding sites (CBSs) in the AML genome by recruiting CTCF/cohesin complex and R-loop-associated regulators to form R-loops. HOTTIP-mediated R-loops reinforce the CTCF boundary and facilitate formation of TADs to drive gene transcription. Either deleting CBS or targeting RNase H to eliminate R-loops in the boundary CBS of ß-catenin TAD impaired CTCF boundary activity, inhibited promoter/enhancer interactions, reduced ß-catenin target expression, and mitigated leukemogenesis in xenograft mouse models with aberrant HOTTIP expression. Thus, HOTTIP-mediated R-loop formation directly reinforces CTCF chromatin boundary activity and TAD integrity to drive oncogene transcription and leukemia development.


Assuntos
Fator de Ligação a CCCTC/metabolismo , Cromatina/metabolismo , Leucemia Mieloide Aguda/metabolismo , Estruturas R-Loop , RNA Longo não Codificante/metabolismo , beta Catenina/metabolismo , Animais , Fator de Ligação a CCCTC/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Cromatina/genética , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Regulação Leucêmica da Expressão Gênica , Células HEK293 , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Camundongos Transgênicos , RNA Longo não Codificante/genética , Relação Estrutura-Atividade , Transcrição Gênica , Ativação Transcricional , beta Catenina/genética , Coesinas
3.
EMBO Rep ; 24(10): e57032, 2023 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-37650863

RESUMO

Bromodomain-containing protein 4 (BRD4) is overexpressed and functionally implicated in various myeloid malignancies. However, the role of BRD4 in normal hematopoiesis remains largely unknown. Here, utilizing an inducible Brd4 knockout mouse model, we find that deletion of Brd4 (Brd4Δ/Δ ) in the hematopoietic system impairs hematopoietic stem cell (HSC) self-renewal and differentiation, which associates with cell cycle arrest and senescence. ATAC-seq analysis shows increased chromatin accessibility in Brd4Δ/Δ hematopoietic stem/progenitor cells (HSC/HPCs). Genome-wide mapping with cleavage under target and release using nuclease (CUT&RUN) assays demonstrate that increased global enrichment of H3K122ac and H3K4me3 in Brd4Δ/Δ HSC/HPCs is associated with the upregulation of senescence-specific genes. Interestingly, Brd4 deletion increases clipped H3 (cH3) which correlates with the upregulation of senescence-specific genes and results in a higher frequency of senescent HSC/HPCs. Re-expression of BRD4 reduces cH3 levels and rescues the senescence rate in Brd4Δ/Δ HSC/HPCs. This study unveils an important role of BRD4 in HSC/HPC function by preventing H3 clipping and suppressing senescence gene expression.


Assuntos
Histonas , Fatores de Transcrição , Animais , Camundongos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Histonas/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Senescência Celular/genética , Células-Tronco Hematopoéticas/metabolismo , Diferenciação Celular , Hematopoese
4.
Nano Lett ; 24(33): 10072-10080, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39132906

RESUMO

Probabilistic bits (p-bits) with thermal- and spin torque-induced nondeterministic magnetization switching are promising candidates for performing probabilistic computing. Previously reported spin torque p-bits include volatile low-energy barrier nanomagnets (LBNMs) with spontaneously fluctuating magnetizations and initialization-necessary nonvolatile magnets. However, initialization-free nonvolatile spin torque p-bits are still lacking. Here, we demonstrate moderately thermal stable spin-orbit torque (SOT) p-bits with non-consecutively deposited Pt//Pt/Co/Pt stacks. Backhopping-like (BH) magnetization switching with a wide range current-tunable probability of final up and down magnetization states from 0% to 100% was achieved, regardless of the initial magnetization state, which was attributed to the interplay of SOT and thermal contributions. Integer factorization using such BH-SOT p-bits in zero magnetic field was demonstrated at times that are significantly shorter than those of existing nonvolatile STT or volatile LBNMs p-bits. Our realization of initialization-free and magnetic field-free moderately thermally stable BH-SOT p-bits opens up a new perspective for probabilistic spintronic applications.

5.
J Cell Physiol ; 239(5): e31248, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38501506

RESUMO

The loss of semaphorin 3A (Sema3A), which is related to endothelial-to-mesenchymal transition (EndMT) in atrial fibrosis, is implicated in the pathogenesis of atrial fibrillation (AF). To explore the mechanisms by which EndMT affects atrial fibrosis and assess the potential of a Sema3A activator (naringin) to prevent atrial fibrosis by targeting transforming growth factor-beta (TGF-ß)-induced EndMT, we used human atria, isolated human atrial endocardial endothelial cells (AEECs), and used transgenic mice expressing TGF-ß specifically in cardiac tissues (TGF-ß transgenic mice). We evaluated an EndMT marker (Twist), a proliferation marker (proliferating cell nuclear antigen; PCNA), and an endothelial cell (EC) marker (CD31) through triple immunohistochemistry and confirmed that both EndMT and EC proliferation contribute to atrial endocardial fibrosis during AF in TGF-ß transgenic mice and AF patient tissue sections. Additionally, we investigated the impact of naringin on EndMT and EC proliferation in AEECs and atrial fibroblasts. Naringin exhibited an antiproliferative effect, to which AEECs were more responsive. Subsequently, we downregulated Sema3A in AEECs using small interfering RNA to clarify a correlation between the reduction in Sema3A and the elevation of EndMT markers. Naringin treatment induced the expression of Sema3A and a concurrent decrease in EndMT markers. Furthermore, naringin administration ameliorated AF and endocardial fibrosis in TGF-ß transgenic mice by stimulating Sema3A expression, inhibiting EndMT markers, reducing atrial fibrosis, and lowering AF vulnerability. This suggests therapeutic potential for naringin in AF treatment.


Assuntos
Fibrilação Atrial , Proliferação de Células , Células Endoteliais , Transição Epitelial-Mesenquimal , Flavanonas , Átrios do Coração , Semaforina-3A , Fator de Crescimento Transformador beta , Animais , Humanos , Masculino , Camundongos , Fibrilação Atrial/metabolismo , Fibrilação Atrial/patologia , Fibrilação Atrial/genética , Fibrilação Atrial/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose , Flavanonas/farmacologia , Átrios do Coração/metabolismo , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/patologia , Camundongos Transgênicos , Semaforina-3A/metabolismo , Semaforina-3A/genética , Fator de Crescimento Transformador beta/metabolismo
6.
J Am Chem Soc ; 146(36): 25137-25150, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39207218

RESUMO

Living crystallization-driven self-assembly (CDSA) has emerged as an efficient strategy to generate nanofibers of π-conjugated polymers (CPNFs) in a controlled fashion. However, reports of donor-acceptor (D-A) heterojunction CPNFs are extremely rare. The preparation of these materials remains a challenge due to the lack of rational design guidelines for the D-A π-conjugated units. Herein, we report a versatile CDSA strategy based upon carefully designed D-A-co-oligomers in which electron-deficient benzothiadiazole (BT) or dibenzo[b,d]thiophene 5,5-dioxide (FSO) units are attached to the two ends of an oligo(p-phenylene ethynylene) heptamer [BT-OPE7-BT, FSO-OPE7-FSO]. This arrangement with the electron-deficient groups at the two ends of the oligomer enhances the stacking interaction of the A-D-A π-conjugated structure. In contrast, D-A-D structures with a single BT in the middle of a string of OPE units disrupt the packing. We employed oligomers with a terminal alkyne to synthesize diblock copolymers BT-OPE7-BT-b-P2VP and BT-OPE7-BT-b-PNIPAM (P2VP = poly(2-vinylpyridine), PNIPAM = poly(N-isopropylacrylamide)) and FSO-OPE7-FSO-b-P2VP and FSO-OPE7-FSO-b-PNIPAM. CDSA experiments with these copolymers in ethanol were able to generate CPNFs of controlled length by both self-seeding and seeded growth as well as block comicelles with precisely tunable length and composition. Furthermore, the D-A CPNFs with a BT-OPE7-BT-based core demonstrate photocatalytic activity for the photooxidation of sulfide to sulfoxide and benzylamine to N-benzylidenebenzylamine. Given the scope of the oligomer compositions examined and the range of structures formed, we believe that the living CDSA strategy with D-A-based co-oligomers opens future opportunities for the creation of D-A CPNFs with programmable architectures as well as diverse functionalities and applications.

7.
Mol Cancer ; 23(1): 215, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39350121

RESUMO

The Nab-paclitaxel combined with gemcitabine (AG) regimen is the main chemotherapy regimen for pancreatic cancer, but drug resistance often occurs. Currently, the ability to promote sensitization in drug-resistant cases is an important clinical issue, and the strategy of repurposing conventional drugs is a promising strategy. This study aimed to identify a classic drug that targets chemotherapy resistance's core signaling pathways and combine it with the AG regimen to enhance chemosensitivity. We also aimed to find reliable predictive biomarkers of drug combination sensitivity. Using RNA sequencing, we found that abnormal PI3K/Akt pathway activation plays a central role in mediating resistance to the AG regimen. Subsequently, through internal and external verification of randomly selected AG-resistant patient-derived organoid (PDO) and PDO xenograft models, we discovered for the first time that the classic anti-inflammatory drug sulindac K-80003, an inhibitor of the PI3K/Akt pathway that we focused on, promoted sensitization in half (14/28) of AG-resistant pancreatic ductal adenocarcinoma cases. Through RNA-sequencing, multiplex immunofluorescent staining, and immunohistochemistry experiments, we identified cFAM124A as a novel biomarker through which sulindac K-80003 promotes AG sensitization. Its role as a sensitization marker is explained via the following mechanism: cFAM124A enhances both the mRNA expression of cathepsin L and the activity of the cathepsin L enzyme. This dual effect stimulates the cleavage of RXRα, leading to large amounts of truncated RXRα, which serves as a direct target of K-80003. Consequently, this process results in the pathological activation of the PI3K/Akt pathway. In summary, our study provides a new treatment strategy and novel biological target for patients with drug-resistant pancreatic cancer.


Assuntos
Albuminas , Protocolos de Quimioterapia Combinada Antineoplásica , Desoxicitidina , Resistencia a Medicamentos Antineoplásicos , Gencitabina , Paclitaxel , Neoplasias Pancreáticas , Sulindaco , Ensaios Antitumorais Modelo de Xenoenxerto , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Humanos , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Animais , Camundongos , Albuminas/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Sulindaco/farmacologia , Sulindaco/análogos & derivados , Linhagem Celular Tumoral , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Feminino , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/metabolismo , Masculino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos
8.
Development ; 148(5)2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33574039

RESUMO

In mice, the entry of germ cells into meiosis crucially depends on the expression of stimulated by retinoic acid gene 8 (Stra8). Stra8 is expressed specifically in pre-meiotic germ cells of females and males, at fetal and postnatal stages, respectively, but the mechanistic details of its spatiotemporal regulation are yet to be defined. In particular, there has been considerable debate regarding whether retinoic acid is required, in vivo, to initiate Stra8 expression in the mouse fetal ovary. We show that the distinctive anterior-to-posterior pattern of Stra8 initiation, characteristic of germ cells in the fetal ovary, is faithfully recapitulated when 2.9 kb of the Stra8 promoter is used to drive eGFP expression. Using in vitro transfection assays of cutdown and mutant constructs, we identified two functional retinoic acid responsive elements (RAREs) within this 2.9 kb regulatory element. We also show that the transcription factor DMRT1 enhances Stra8 expression, but only in the presence of RA and the most proximal RARE. Finally, we used CRISPR/Cas9-mediated targeted mutation studies to demonstrate that both RAREs are required for optimal Stra8 expression levels in vivo.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Células Germinativas/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Sítios de Ligação , Sistemas CRISPR-Cas/genética , Feminino , Desenvolvimento Fetal/genética , Feto/citologia , Feto/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Células Germinativas/citologia , Meiose , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutagênese , Ovário/citologia , Ovário/metabolismo , Regiões Promotoras Genéticas , Receptores X de Retinoides/genética , Receptores X de Retinoides/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/farmacologia , Tretinoína/farmacologia
9.
Ann Surg Oncol ; 31(6): 4138-4147, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38396039

RESUMO

BACKGROUND: Although social vulnerability has been associated with worse postoperative and oncologic outcomes in other cancer types, these effects have not been characterized in patients with soft tissue sarcoma. This study evaluated the association of social vulnerability and oncologic outcomes. METHODS: The authors conducted a single-institution cohort study of adult patients with primary and locally recurrent extremity or truncal soft tissue sarcoma undergoing resection between January 2016 and December 2021. The social vulnerability index (SVI) was measured on a low (SVI 1-39%, least vulnerable) to high (60-100%, most vulnerable) SVI scale. The association of SVI with overall survival (OS) and recurrence-free survival (RFS) was evaluated by Kaplan-Meier analysis and Cox proportional hazard regression. RESULTS: The study identified 577 patients. The median SVI was 44 (interquartile range [IQR], 19-67), with 195 patients categorized as high SVI and 265 patients as low SVI. The median age, tumor size, histologic subtype, grade, comorbidities, stage, follow-up time, and perioperative chemotherapy and radiation utilization were similar between the high and low SVI cohorts. The patients with high SVI had worse OS (p = 0.07) and RFS (p = 0.016) than the patients with low SVI. High SVI was independently associated with shorter RFS in the multivariate analysis (hazard ratio, 1.64; 95% confidence interval, 1.06-2.54) but not with OS (HR, 1.47; 95% CI 0.84-2.56). CONCLUSION: High community-level social vulnerability appears to be independently associated with worse RFS for patients undergoing resection of extremity and truncal soft tissue sarcoma. The effect of patient and community-level social risk factors should be considered in the treatment of patients with extremity sarcoma.


Assuntos
Extremidades , Recidiva Local de Neoplasia , Sarcoma , Humanos , Feminino , Masculino , Sarcoma/cirurgia , Sarcoma/mortalidade , Sarcoma/patologia , Pessoa de Meia-Idade , Extremidades/cirurgia , Extremidades/patologia , Taxa de Sobrevida , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Recidiva Local de Neoplasia/mortalidade , Idoso , Seguimentos , Prognóstico , Adulto , Populações Vulneráveis , Tronco/cirurgia , Tronco/patologia , Estudos Retrospectivos , Fatores de Risco , Neoplasias de Tecidos Moles/cirurgia , Neoplasias de Tecidos Moles/mortalidade , Neoplasias de Tecidos Moles/patologia
10.
Opt Express ; 32(2): 2321-2332, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38297765

RESUMO

Deep learning-based computer-generated holography (DeepCGH) has the ability to generate three-dimensional multiphoton stimulation nearly 1,000 times faster than conventional CGH approaches such as the Gerchberg-Saxton (GS) iterative algorithm. However, existing DeepCGH methods cannot achieve axial confinement at the several-micron scale. Moreover, they suffer from an extended inference time as the number of stimulation locations at different depths (i.e., the number of input layers in the neural network) increases. Accordingly, this study proposes an unsupervised U-Net DeepCGH model enhanced with temporal focusing (TF), which currently achieves an axial resolution of around 5 µm. The proposed model employs a digital propagation matrix (DPM) in the data preprocessing stage, which enables stimulation at arbitrary depth locations and reduces the computation time by more than 35%. Through physical constraint learning using an improved loss function related to the TF excitation efficiency, the axial resolution and excitation intensity of the proposed TF-DeepCGH with DPM rival that of the optimal GS with TF method but with a greatly increased computational efficiency.

11.
Chemistry ; : e202403680, 2024 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-39431983

RESUMO

The diiron-containing YtfE protein in Escherichia coli is pivotal in counteracting nitrosative stress, a critical barrier to bacterial viability. This study delves into the biochemical complexity governing YtfE's conversion of nitric oxide (NO) to nitrous oxide, a key process for alleviating nitrosative stress. Through site-directed mutagenesis, we explored YtfE's molecular structure, with a particular focus on two internal transport tunnels important for its activity. Our findings illuminate Tunnel 1 as the primary conduit for substrate transport, regulated by conformational shifts within the N-terminal domain that enable substrate access to the diiron core in the C-terminal domain. Tunnel 2 emerges as a secondary, supportive route, activated when Tunnel 1 is compromised. This result challenges a previous model of distinct tunnels for substrate entry and product exit, suggesting both tunnels are capable of transporting substrates and products. Our engineering efforts enhanced the role of Tunnel 2, enabling a synergistic operation with Tunnel 1 and tripling YtfE's enzymatic activity compared to its wild-type form. This research not only deepens our understanding of YtfE's regulatory mechanism for NO reduction but also introduces a strategy to amplify its enzymatic efficiency. The outcomes offer new ravenues for modulating bacterial stress responses.

12.
Anim Cogn ; 27(1): 26, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38530499

RESUMO

Little is known about the behavioral and cognitive traits that best predict invasion success. Evidence is mounting that cognitive performance correlates with survival and fecundity, two pivotal factors for the successful establishment of invasive populations. We assessed the quantity discrimination ability of the globally invasive red-eared slider (Trachemys scripta elegans). We further compared it to that of the native stripe-necked turtle (Mauremys sinensis), which has been previously evaluated for its superior quantity discrimination ability. Specifically, our experimental designs aimed to quantify the learning ability as numerosity pairs increased in difficulty (termed fixed numerosity tests), and the immediate response when turtles were presented with varied challenges concurrently in the same tests (termed mixed numerosity tests). Our findings reaffirm the remarkable ability of freshwater turtles to discern numerical differences as close as 9 vs 10 (ratio = 0.9), which was comparable to the stripe-necked turtle's performance. However, the red-eared slider exhibited a moderate decrease in performance in high ratio tests, indicating a potentially enhanced cognitive capacity to adapt to novel challenges. Our experimental design is repeatable and is adaptable to a range of freshwater turtles. These findings emphasize the potential importance of cognitive research to the underlying mechanisms of successful species invasions.


Assuntos
Tartarugas , Animais , Tartarugas/fisiologia , Projetos de Pesquisa , Adaptação Fisiológica
13.
J Org Chem ; 2024 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-39396198

RESUMO

A palladium-catalyzed annulation reaction of bay-diiodinated arenes with o-chloroaromatic carboxylic acids was established. This approach enables the synthesis of a variety of polycyclic aromatic compounds, especially polyalkoxy-substituted polycyclic aromatic compounds, frequently found in discotic liquid-crystalline materials. The investigations indicate that the product 2,3,8,9,12,13-hexakis(hexyloxy)-5-azadibenzo[fg,op]tetracene demonstrates favorable room-temperature liquid-crystalline properties.

14.
J Org Chem ; 89(6): 4085-4097, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38394366

RESUMO

A palladium-catalyzed annulative π-extension reaction of bay-iodinated triphenylenes with aryl iodides/o-chloroaromatic carboxylic acids was developed. This approach enabled the synthesis of diverse polycyclic aromatic compounds, including dibenzo[fg,op]tetracenes, azadibenzo[fg,op]tetracenes, and tribenzo[a,g,m]coronenes. Initial studies indicate that the resulting product, 2,3,8,9,14,15-hexakis(decyloxy)tribenzo[a,g,m]coronene, exhibits good liquid-crystalline properties.

15.
J Immunol ; 208(2): 321-327, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34911771

RESUMO

Previous studies have demonstrated that 8-hydroxydeoxyguanosine (8-OHdG) exerted key roles in various pulmonary diseases, but the evidence for its role in community-acquired pneumonia (CAP) was lacking. The goal of this research was to evaluate the correlations of serum 8-OHdG with the severity and prognosis among patients with CAP through a prospective cohort study. A total of 239 patients with CAP and 239 healthy participants were enrolled. Fasting blood samples were collected. 8-OHdG and inflammatory cytokines were measured by ELISA. On admission, serum 8-OHdG was significantly increased in patients with CAP compared with control subjects. Besides, serum 8-OHdG was incrementally increased in line with CAP severity scores. Pearson correlative analysis found that serum 8-OHdG was correlated with clinical characteristics and inflammatory cytokines in patients with CAP. Linear and logistic regression analysis showed that serum 8-OHdG was positively associated with CAP severity scores. Furthermore, the prognostic outcomes were tracked. Higher serum 8-OHdG on admission increased the risks for intensive care unit admission, mechanical ventilation, vasoactive agent usage, death, and longer hospital stay among patients with CAP. Serum 8-OHdG combination with confusion, respiratory rate, blood pressure, and age ≥65 y or pneumonia severity index had stronger predictive powers for death than single 8-OHdG, CAP severity scores, or several inflammatory cytokines in patients with CAP. These results indicated that serum 8-OHdG is positively associated with the severity and poor prognosis in patients with CAP, demonstrating that 8-OHdG may be involved in the pathophysiology process of CAP.


Assuntos
8-Hidroxi-2'-Desoxiguanosina/sangue , Infecções Comunitárias Adquiridas/patologia , Pneumonia/sangue , Pneumonia/mortalidade , Índice de Gravidade de Doença , Idoso , Biomarcadores/sangue , Infecções Comunitárias Adquiridas/sangue , Cuidados Críticos/estatística & dados numéricos , Citocinas/sangue , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/fisiologia , Pneumonia/patologia , Prognóstico , Estudos Prospectivos , Respiração Artificial/estatística & dados numéricos
16.
Macromol Rapid Commun ; 45(2): e2300482, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37922939

RESUMO

Living crystallization-driven self-assembly (CDSA) has emerged as an efficient route to generate π-conjugated-polymer-based nanofibers (CPNFs) with promising applications from photocatalysis to biomedicine. However, the lack of efficient tools to endow CPNFs with morphological stability and surface tailorability becomes a frustrating hindrance for expanding application spectrum of CPNFs. Herein, a facile strategy to fabricate length-controllable OPV-based (OPV = oligo(p-phenylenevinylene)) CPNFs containing a cross-linked shell with high morphological stability and facile surface tailorability through the combination of living CDSA and thiol-ene chemistry by using OPV5 -b-PNAAM32 (PNAAM = poly(N-allyl acrylamide)) as a model is reported. Uniform fiber-like micelles with tunable length can be generated by self-seeding of living CDSA. By taking advantage of radical thiol-ene reaction between vinyls of PNAAM corona and four-arm thiols, the shell of micelles can be cross-linked with negligible destruction of structure of vinylene-containing OPV core. The resulting micelles show high morphological stability in NaCl solution and PBS buffer, even upon heating at 80 °C. The introduced extra thiol groups in the cross-linked shell can be further employed to install extra functional moieties via convenient thiol-Michael-type reaction. Given the negligible cytotoxicity of resulting CPNFs, this strategy opens an avenue to fabricate various CPNFs of diverse functionalities for biomedicine.


Assuntos
Micelas , Nanofibras , Polímeros/química , Cristalização , Compostos de Sulfidrila/química
17.
J Sex Marital Ther ; 50(3): 326-341, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38018139

RESUMO

Problematic pornography use and its adverse consequences are prevalent, but little is known about its psychosocial contributors. Drawing on the Differential Susceptibility to Media Effects Model (DSMM), this study explores whether and how perceived problematic Internet pornography use is associated with psychological factors from three domains: social (i.e., family adaptability), dispositional (i.e., self-acceptance), and development factors (i.e., impulse control difficulties). Analysis of an anonymous survey of 1,483 Chinese emerging adults showed that family adaptability and self-acceptance were negatively correlated with perceived problematic pornography use, whereas impulse control difficulties were positively correlated with perceived problematic pornography use. Self-acceptance mediated the association between family adaptability and perceived problematic pornography use. Impulse control difficulties moderated such mediation effect, in which the protective effect of family adaptability on self-acceptance and that of self-acceptance on perceived problematic pornography use were attenuated by impulse control difficulties. These findings advance understanding of the complex underlying psychosocial mechanisms of perceived problematic pornography use by providing evidence to the applicability of DSMM on such problematic use and clarifying the direct, indirect, and/or moderating role(s) of family adaptability, self-acceptance, and impulse control difficulties in those mechanisms. They also provide insights for targeted approaches in future intervention programs among emerging adults.


Assuntos
Literatura Erótica , Personalidade , Adulto , Humanos , Literatura Erótica/psicologia , Inquéritos e Questionários
18.
Acta Pharmacol Sin ; 45(9): 1912-1925, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38684800

RESUMO

Ulcerative colitis (UC) is associated with changed dietary habits and mainly linked with the gut microbiota dysbiosis, necroptosis of epithelial cells, and mucosal ulcerations. Liver dysfunction and abnormal level of liver metabolism indices were identified in UC patients, suggesting a close interaction between gut and liver disorders. Methionine-choline deficient diet (MCD) has been shown to induce persistent alterations of gut microbiota and metabolome during hepatitis. In this study we further explored the disease phenotypes in UC patients and investigated whether MCD functioned as a trigger for UC susceptibility. After assessing 88 serum specimens from UC patients, we found significant liver dysfunction and dyslipidemia including abnormal ALT, AST, TG, TC, LDL-c and HDL-c. Liver dysfunction and dyslipidemia were confirmed in DSS-induced colitis mice. We fed mice with MCD for 14 days to cause mild liver damage, and then treated with DSS for 7 days. We found that MCD intake significantly exacerbated the pathogenesis of mucosal inflammation in DSS-induced acute, progressive, and chronic colitis, referring to promotion of mucosal ulcers, colon shortening, diarrhea, inflammatory immune cell infiltration, cytokines release, and abnormal activation of inflammatory macrophages in colon and liver specimens. Intraperitoneal injection of clodronate liposomes to globally delete macrophages dramatically compromised the pathogenesis of MCD-triggering colitis. In addition, MCD intake markedly changed the production pattern of short-chain fatty acids (SCFAs) in murine stools, colons, and livers. We demonstrated that MCD-induced colitis pathogenesis largely depended on the gut microbes and the disease phenotypes could be transmissible through fecal microbiota transplantation (FMT). In conclusion, this study supports the concept that intake of MCD predisposes to experimental colitis and enhances its pathogenesis via modulating gut microbes and macrophages in mice.


Assuntos
Sulfato de Dextrana , Microbioma Gastrointestinal , Macrófagos , Metionina , Camundongos Endogâmicos C57BL , Animais , Metionina/deficiência , Macrófagos/metabolismo , Macrófagos/imunologia , Masculino , Camundongos , Sulfato de Dextrana/toxicidade , Humanos , Colite Ulcerativa/microbiologia , Colite Ulcerativa/patologia , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/imunologia , Deficiência de Colina/complicações , Feminino , Dieta , Colina/metabolismo , Colo/patologia , Colo/microbiologia , Colo/imunologia , Colite/microbiologia , Colite/patologia , Colite/induzido quimicamente , Fígado/patologia , Fígado/metabolismo
19.
J Nanobiotechnology ; 22(1): 308, 2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38825711

RESUMO

Research into mRNA vaccines is advancing rapidly, with proven efficacy against coronavirus disease 2019 and promising therapeutic potential against a variety of solid tumors. Adjuvants, critical components of mRNA vaccines, significantly enhance vaccine effectiveness and are integral to numerous mRNA vaccine formulations. However, the development and selection of adjuvant platforms are still in their nascent stages, and the mechanisms of many adjuvants remain poorly understood. Additionally, the immunostimulatory capabilities of certain novel drug delivery systems (DDS) challenge the traditional definition of adjuvants, suggesting that a revision of this concept is necessary. This review offers a comprehensive exploration of the mechanisms and applications of adjuvants and self-adjuvant DDS. It thoroughly addresses existing issues mentioned above and details three main challenges of immune-related adverse event, unclear mechanisms, and unsatisfactory outcomes in old age group in the design and practical application of cancer mRNA vaccine adjuvants. Ultimately, this review proposes three optimization strategies which consists of exploring the mechanisms of adjuvant, optimizing DDS, and improving route of administration to improve effectiveness and application of adjuvants and self-adjuvant DDS.


Assuntos
Adjuvantes Imunológicos , Vacinas Anticâncer , Nanotecnologia , Neoplasias , Vacinas de mRNA , Humanos , Vacinas Anticâncer/imunologia , Nanotecnologia/métodos , Neoplasias/terapia , Neoplasias/imunologia , Animais , Sistemas de Liberação de Medicamentos/métodos , COVID-19/prevenção & controle , Adjuvantes de Vacinas , RNA Mensageiro/genética , SARS-CoV-2/imunologia , Vacinas Sintéticas/imunologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-39317914

RESUMO

PURPOSE: In vitro maturation (IVM) of oocytes is a promising technique among assisted reproductive technologies. Although IVM has been used for many years, its efficiency is still relatively low compared to that of traditional in vitro fertilization (IVF) procedures. Therefore, we aimed to explore the hotspots and frontiers of IVM research over the past two decades and provide direction for IVM advancement. METHODS: The articles and reviews related to IVM in the Web of Science Core Collection (WoSCC) were retrieved on June 03, 2024. Three bibliometric tools, VOSviewer 1.6.18 (2010), CiteSpace 6.1. R6 (2006), and Bibliometrix R package 4.1.0 (2017), were used to generate network maps and explore knowledge frontiers and trends. To uncover the latest research advancements and frontiers in the IVM field, we conducted an analysis of the entire IVM field, including all species. Given our focus on human IVM developments, we identified the leading countries, institutions, authors, and journals driving progress in human IVM. RESULTS: A total of 5150 publications about IVM and 1534 publications in the specific context of human IVM were retrieved from the WoSCC. The number of publications on both overall IVM and human IVM fields has increased steadily. In human IVM, the United States (USA) and McGill University were the most prolific country and institution, respectively. Human Reproduction was both the most published in and the most cited journal in human IVM. Seang Lin, Tan was the most productive author, and Ri-Cheng, Chian's papers were the most cited in human IVM. Furthermore, five hotspot topics were summarized, namely, culture system, supplementation, cooperation in the ovarian follicle, gene expression, and oocyte cryopreservation. CONCLUSIONS: Further studies could concentrate on the following topics: (1) the mechanisms involved in oocyte maturation in vivo and in vitro, especially in energy metabolism and intercellular communications; (2) the establishment of IVM culture systems, including standardization of the biphasic IVM culture system and supplementation; (3) the genetic differences between oocytes matured in vivo and in vitro; and (4) the mechanism of cryopreservation-inflicted damage and solutions to this challenge. For human IVM, it is necessary to precisely assess the developmental stages of oocytes and adjust the IVM process accordingly to develop tailored culture media. Concurrently, clinical trials are essential for evaluating the effectiveness and safety of IVM.

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