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1.
Cell ; 180(1): 107-121.e17, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31866069

RESUMO

Fibrosis can develop in most organs and causes organ failure. The most common type of lung fibrosis is known as idiopathic pulmonary fibrosis, in which fibrosis starts at the lung periphery and then progresses toward the lung center, eventually causing respiratory failure. Little is known about the mechanisms underlying the pathogenesis and periphery-to-center progression of the disease. Here we discovered that loss of Cdc42 function in alveolar stem cells (AT2 cells) causes periphery-to-center progressive lung fibrosis. We further show that Cdc42-null AT2 cells in both post-pneumonectomy and untreated aged mice cannot regenerate new alveoli, resulting in sustained exposure of AT2 cells to elevated mechanical tension. We demonstrate that elevated mechanical tension activates a TGF-ß signaling loop in AT2 cells, which drives the periphery-to-center progression of lung fibrosis. Our study establishes a direct mechanistic link between impaired alveolar regeneration, mechanical tension, and progressive lung fibrosis.


Assuntos
Células-Tronco Adultas/metabolismo , Fibrose Pulmonar Idiopática/etiologia , Alvéolos Pulmonares/metabolismo , Células-Tronco Adultas/patologia , Idoso , Células Epiteliais Alveolares/patologia , Animais , Fenômenos Biomecânicos/fisiologia , Feminino , Fibrose/patologia , Humanos , Fibrose Pulmonar Idiopática/metabolismo , Fibrose Pulmonar Idiopática/patologia , Pulmão/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Alvéolos Pulmonares/patologia , Regeneração , Transdução de Sinais , Células-Tronco/patologia , Estresse Mecânico , Estresse Fisiológico/fisiologia , Fator de Crescimento Transformador beta/metabolismo , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismo
3.
Nature ; 602(7897): 431-436, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35173341

RESUMO

Marked evolution of properties with minute changes in the doping level is a hallmark of the complex chemistry that governs copper oxide superconductivity as manifested in the celebrated superconducting domes and quantum criticality taking place at precise compositions1-4. The strange-metal state, in which the resistivity varies linearly with temperature, has emerged as a central feature in the normal state of copper oxide superconductors5-9. The ubiquity of this behaviour signals an intimate link between the scattering mechanism and superconductivity10-12. However, a clear quantitative picture of the correlation has been lacking. Here we report the observation of precise quantitative scaling laws among the superconducting transition temperature (Tc), the linear-in-T scattering coefficient (A1) and the doping level (x) in electron-doped copper oxide La2-xCexCuO4 (LCCO). High-resolution characterization of epitaxial composition-spread films, which encompass the entire overdoped range of LCCO, has enabled us to systematically map its structural and transport properties with unprecedented accuracy and with increments of Δx = 0.0015. We have uncovered the relations Tc ~ (xc - x)0.5 ~ (A1□)0.5, where xc is the critical doping in which superconductivity disappears and A1□ is the coefficient of the linear resistivity per CuO2 plane. The striking similarity of the Tc versus A1□ relation among copper oxides, iron-based and organic superconductors may be an indication of a common mechanism of the strange-metal behaviour and unconventional superconductivity in these systems.

4.
Nature ; 599(7884): 222-228, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34587621

RESUMO

The transition metal kagome lattice materials host frustrated, correlated and topological quantum states of matter1-9. Recently, a new family of vanadium-based kagome metals, AV3Sb5 (A = K, Rb or Cs), with topological band structures has been discovered10,11. These layered compounds are nonmagnetic and undergo charge density wave transitions before developing superconductivity at low temperatures11-19. Here we report the observation of unconventional superconductivity and a pair density wave (PDW) in CsV3Sb5 using scanning tunnelling microscope/spectroscopy and Josephson scanning tunnelling spectroscopy. We find that CsV3Sb5 exhibits a V-shaped pairing gap Δ ~ 0.5 meV and is a strong-coupling superconductor (2Δ/kBTc ~ 5) that coexists with 4a0 unidirectional and 2a0 × 2a0 charge order. Remarkably, we discover a 3Q PDW accompanied by bidirectional 4a0/3 spatial modulations of the superconducting gap, coherence peak and gap depth in the tunnelling conductance. We term this novel quantum state a roton PDW associated with an underlying vortex-antivortex lattice that can account for the observed conductance modulations. Probing the electronic states in the vortex halo in an applied magnetic field, in strong field that suppresses superconductivity and in zero field above Tc, reveals that the PDW is a primary state responsible for an emergent pseudogap and intertwined electronic order. Our findings show striking analogies and distinctions to the phenomenology of high-Tc cuprate superconductors, and provide groundwork for understanding the microscopic origin of correlated electronic states and superconductivity in vanadium-based kagome metals.

5.
Brief Bioinform ; 25(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38343327

RESUMO

Hyperactive ribosome biogenesis (RiboSis) fuels unrestricted cell proliferation, whereas genomic hallmarks and therapeutic targets of RiboSis in cancers remain elusive, and efficient approaches to quantify RiboSis activity are still limited. Here, we have established an in silico approach to conveniently score RiboSis activity based on individual transcriptome data. By employing this novel approach and RNA-seq data of 14 645 samples from TCGA/GTEx dataset and 917 294 single-cell expression profiles across 13 cancer types, we observed the elevated activity of RiboSis in malignant cells of various human cancers, and high risk of severe outcomes in patients with high RiboSis activity. Our mining of pan-cancer multi-omics data characterized numerous molecular alterations of RiboSis, and unveiled the predominant somatic alteration in RiboSis genes was copy number variation. A total of 128 RiboSis genes, including EXOSC4, BOP1, RPLP0P6 and UTP23, were identified as potential therapeutic targets. Interestingly, we observed that the activity of RiboSis was associated with TP53 mutations, and hyperactive RiboSis was associated with poor outcomes in lung cancer patients without TP53 mutations, highlighting the importance of considering TP53 mutations during therapy by impairing RiboSis. Moreover, we predicted 23 compounds, including methotrexate and CX-5461, associated with the expression signature of RiboSis genes. The current study generates a comprehensive blueprint of molecular alterations in RiboSis genes across cancers, which provides a valuable resource for RiboSis-based anti-tumor therapy.


Assuntos
Variações do Número de Cópias de DNA , Neoplasias , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Genômica , Mutação , Ribossomos/genética , Ribossomos/metabolismo , Proteínas de Ligação a RNA/genética
6.
Nature ; 579(7797): 118-122, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32103178

RESUMO

It has long been assumed that lifespan and healthspan correlate strongly, yet the two can be clearly dissociated1-6. Although there has been a global increase in human life expectancy, increasing longevity is rarely accompanied by an extended healthspan4,7. Thus, understanding the origin of healthy behaviours in old people remains an important and challenging task. Here we report a conserved epigenetic mechanism underlying healthy ageing. Through genome-wide RNA-interference-based screening of genes that regulate behavioural deterioration in ageing Caenorhabditis elegans, we identify 59 genes as potential modulators of the rate of age-related behavioural deterioration. Among these modulators, we found that a neuronal epigenetic reader, BAZ-2, and a neuronal histone 3 lysine 9 methyltransferase, SET-6, accelerate behavioural deterioration in C. elegans by reducing mitochondrial function, repressing the expression of nuclear-encoded mitochondrial proteins. This mechanism is conserved in cultured mouse neurons and human cells. Examination of human databases8,9 shows that expression of the human orthologues of these C. elegans regulators, BAZ2B and EHMT1, in the frontal cortex increases with age and correlates positively with the progression of Alzheimer's disease. Furthermore, ablation of Baz2b, the mouse orthologue of BAZ-2, attenuates age-dependent body-weight gain and prevents cognitive decline in ageing mice. Thus our genome-wide RNA-interference screen in C. elegans has unravelled conserved epigenetic negative regulators of ageing, suggesting possible ways to achieve healthy ageing.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Epigênese Genética , Envelhecimento Saudável/genética , Histona-Lisina N-Metiltransferase/metabolismo , Fatores Genéricos de Transcrição/metabolismo , Envelhecimento/genética , Animais , Proteínas de Caenorhabditis elegans/genética , Cognição , Disfunção Cognitiva , Histona-Lisina N-Metiltransferase/deficiência , Histona-Lisina N-Metiltransferase/genética , Histonas/química , Histonas/metabolismo , Humanos , Longevidade/genética , Lisina/metabolismo , Masculino , Memória , Metilação , Camundongos , Mitocôndrias/metabolismo , Neurônios/metabolismo , Proteínas/genética , Interferência de RNA , Aprendizagem Espacial , Fatores Genéricos de Transcrição/deficiência , Fatores Genéricos de Transcrição/genética
7.
Plant J ; 117(4): 1069-1083, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37947285

RESUMO

The color of purple carrot taproots mainly depends on the anthocyanins sequestered in the vacuoles. Glutathione S-transferases (GSTs) are key enzymes involved in anthocyanin transport. However, the precise mechanism of anthocyanin transport from the cytosolic surface of the endoplasmic reticulum (ER) to the vacuoles in carrots remains unclear. In this study, we conducted a comprehensive analysis of the carrot genome, leading to the identification of a total of 41 DcGST genes. Among these, DcGST1 emerged as a prominent candidate, displaying a strong positive correlation with anthocyanin pigmentation in carrot taproots. It was highly expressed in the purple taproot tissues of purple carrot cultivars, while it was virtually inactive in the non-purple taproot tissues of purple and non-purple carrot cultivars. DcGST1, a homolog of Arabidopsis thaliana TRANSPARENT TESTA 19 (TT19), belongs to the GSTF clade and plays a crucial role in anthocyanin transport. Using the CRISPR/Cas9 system, we successfully knocked out DcGST1 in the solid purple carrot cultivar 'Deep Purple' ('DPP'), resulting in carrots with orange taproots. Additionally, DcMYB7, an anthocyanin activator, binds to the DcGST1 promoter, activating its expression. Compared with the expression DcMYB7 alone, co-expression of DcGST1 and DcMYB7 significantly increased anthocyanin accumulation in carrot calli. However, overexpression of DcGST1 in the two purple carrot cultivars did not change the anthocyanin accumulation pattern or significantly increase the anthocyanin content. These findings improve our understanding of anthocyanin transport mechanisms in plants, providing a molecular foundation for improving and enhancing carrot germplasm.


Assuntos
Antocianinas , Daucus carota , Antocianinas/metabolismo , Daucus carota/genética , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Pigmentação/genética
8.
Gut ; 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38981667

RESUMO

OBJECTIVE: The metabolic characteristics of liver cancer drive considerable hurdles to immune cells function and cancer immunotherapy. However, how metabolic reprograming in the tumour microenvironment impairs the antitumour immune response remains unclear. DESIGN: Human samples and multiple murine models were employed to evaluate the correlation between GPR109A and liver cancer progression. GPR109A knockout mice, immune cells depletion and primary cell coculture models were used to determine the regulation of GPR109A on tumour microenvironment and identify the underlying mechanism responsible for the formation of intratumour GPR109A+myeloid cells. RESULTS: We demonstrate that glutamine shortage in liver cancer tumour microenvironment drives an immunosuppressive GPR109A+myeloid cells infiltration, leading to the evasion of immune surveillance. Blockade of GPR109A decreases G-MDSCs and M2-like TAMs abundance to trigger the antitumour responses of CD8+ T cells and further improves the immunotherapy efficacy against liver cancer. Mechanistically, tumour cells and tumour-infiltrated myeloid cells compete for glutamine uptake via the transporter SLC1A5 to control antitumour immunity, which disrupts the endoplasmic reticulum (ER) homoeostasis and induces unfolded protein response of myeloid cells to promote GPR109A expression through IRE1α/XBP1 pathway. The restriction of glutamine uptake in liver cancer cells, as well as the blockade of IRE1α/XBP1 signalling or glutamine supplementation, can eliminate the immunosuppressive effects of GPR109A+ myeloid cells and slow down tumour progression. CONCLUSION: Our findings identify the immunometabolic crosstalk between liver cancer cells and myeloid cells facilitates tumour progression via a glutamine metabolism/ER stress/GPR109A axis, suggesting that GPR109A can be exploited as an immunometabolic checkpoint and putative target for cancer treatment.

9.
Biophys J ; 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38853434

RESUMO

Endothelial cells (ECs) experience a variety of highly dynamic mechanical stresses. Among others, cyclic stretch and increased plasma membrane tension inhibit clathrin-mediated endocytosis (CME) in non-ECs. It remains elusive how ECs maintain CME in these biophysically unfavorable conditions. Previously, we have used simultaneous two-wavelength axial ratiometry (STAR) microscopy to show that endocytic dynamics are similar between statically cultured human umbilical vein endothelial cells (HUVECs) and fibroblast-like Cos-7 cells. Here, we asked whether biophysical stresses generated by blood flow influence CME. We used our data processing platform-DrSTAR-to examine if clathrin dynamics are altered in HUVECs after experiencing fluidic shear stress (FSS). We found that HUVECs cultivated under a physiological level of FSS had increased clathrin dynamics compared with static controls. FSS increased both clathrin-coated vesicle formation and nonproductive flat clathrin lattices by 2.3-fold and 1.9-fold, respectively. The curvature-positive events had significantly delayed curvature initiation relative to clathrin recruitment in flow-stimulated cells, highlighting a shift toward flat-to-curved clathrin transitions in vesicle formation. Overall, our findings indicate that clathrin dynamics and clathrin-coated vesicle formation can be modulated by the local physiological environment and represent an important regulatory mechanism.

10.
Stroke ; 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38920043

RESUMO

BACKGROUND: This study aimed to quantify the global stroke burden attributable to low physical activity and high body mass index in adults aged ≥55 years using data from the Global Burden of Disease 2019 study. METHODS: We extracted data on stroke mortality, disability-adjusted life years, and risk factor exposure from the Global Burden of Disease 2019 study for people aged ≥55 years. We calculated the population-attributable fraction and absolute number of stroke cases and disability-adjusted life years attributable to low physical activity and high body mass index by location, age group, sex, and year. RESULTS: Globally, body mass index and physical inactivity-attributable stroke burden have declined modestly since 1990, but with diverging escalatory regional trajectories. Population growth and aging drive this rising burden. CONCLUSIONS: Multidimensional, context-specific strategies focused on modifiable lifestyle risks are imperative to address the modest declines and escalatory regional trajectories in body mass index and physical inactivity-attributable stroke burden.

11.
J Mol Recognit ; 37(2): e3071, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38167828

RESUMO

Cancer is associated with the highest mortality rate globally. While life-saving screening and treatments exist, better awareness is needed. RNF187, an E3 ligase regulating biological processes, belongs to the RING domain-containing E3 ligase family. RNF187 may serve as an oncogene due to abnormal expression in tumors. However, its association with immune infiltration and prognosis across various cancers remains unclear. We searched several databases including TCGA, GTE x, CCLE, TIMER, and GSEA. R software was used to evaluate RNF187 differential expression, survival, pathology stage, DNA methylation, tumor mutational burden (TMB), microsatellite instability (MSI), gene co-expression analysis, mismatch repairs (MMRs), tumor microenvironment (TME), and immune cell infiltration. Clinicopathological data were collected, and immunohistochemistry was used to verify RNF187 expression in tumor tissues. RNF187 expression was up-regulated in various cancers compared to that in normal tissues and associated with poor patient outcomes. Dysregulation of RNF187 expression in multiple cancer types was strongly correlated with DNA methylation, MMR, MSI, and TMB. RNF187 could interact with different immune cells in cancers. Biomarkers associated with RNF187 may be helpful for prognosis and immunology in treating pan-cancer patients.


Assuntos
Biomarcadores Tumorais , Neoplasias , Humanos , Biomarcadores Tumorais/genética , Prognóstico , Neoplasias/diagnóstico , Neoplasias/genética , Software , Ubiquitina-Proteína Ligases/genética , Microambiente Tumoral/genética , Transativadores
12.
J Transl Med ; 22(1): 580, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898490

RESUMO

The importance of the immune microenvironment in poorly cohesive carcinoma (PCC) has been highlighted due to its limited response rate to conventional therapy and emerging treatment resistance. A combination of clinical cohorts, bioinformatics analyses, and functional/molecular experiments revealed that high infiltration of Interferon Induced Protein with Tetratricopeptide Repeats 1 (IFIT1) + tumor-associated neutrophils (TANs) is a distinguishing feature of PCC patients. Upregulation of IFIT1 + TANs promote migration and invasion of gastric cancer (GC) cell lines (MKN45 and MKN74) and stimulates the growth of cell-derived xenograft models. Besides, by promoting macrophage secreted phosphoprotein 1 (SPP1) expression and facilitating cancer-associated fibroblast and endothelial cell recruitment and activation through TANs, IFIT1 promotes a mesenchymal phenotype, which is associated with a poor prognosis. Importantly, compared to non-PCC (NPCC), PCC tumors is more immunosuppressive. Mechanistically, IFIT1 can be stimulated by IFN-γ and contributes to the expression of Programmed Cell Death 1 Ligand (PDL1) in TANs. We demonstrated in mouse models that IFIT1 + PDL1 + TANs can induce acquired resistance to anti-PD-1 immunotherapy, which may be responsible for the difficulty of PCC patients to benefit from immunotherapy. This work highlights the role of IFIT1 + TANs in mediating the remodeling of the tumor immune microenvironment and immunotherapeutic resistance and introduces IFIT1 + TANs as a promising target for precision therapy of PCC.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Neutrófilos , Proteínas de Ligação a RNA , Humanos , Neutrófilos/imunologia , Neutrófilos/metabolismo , Animais , Proteínas de Ligação a RNA/metabolismo , Linhagem Celular Tumoral , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Microambiente Tumoral/imunologia , Feminino , Antígeno B7-H1/metabolismo , Neoplasias Gástricas/patologia , Neoplasias Gástricas/imunologia , Masculino , Camundongos , Resistencia a Medicamentos Antineoplásicos , Movimento Celular , Tolerância Imunológica , Terapia de Imunossupressão , Regulação Neoplásica da Expressão Gênica , Invasividade Neoplásica , Camundongos Nus , Imunoterapia , Pessoa de Meia-Idade
13.
J Transl Med ; 22(1): 549, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849852

RESUMO

Cellular communication (CC) influences tumor development by mediating intercellular junctions between cells. However, the role and underlying mechanisms of CC in malignant transformation remain unknown. Here, we investigated the spatiotemporal heterogeneity of CC molecular expression during malignant transformation. It was found that although both tight junctions (TJs) and gap junctions (GJs) were involved in maintaining the tumor microenvironment (TME), they exhibited opposite characteristics. Mechanistically, for epithelial cells (parenchymal component), the expression of TJ molecules consistently decreased during normal-cancer transformation and is a potential oncogenic factor. For fibroblasts (mesenchymal component), the expression of GJs consistently increased during normal-cancer transformation and is a potential oncogenic factor. In addition, the molecular profiles of TJs and GJs were used to stratify colorectal cancer (CRC) patients, where subtypes characterized by high GJ levels and low TJ levels exhibited enhanced mesenchymal signals. Importantly, we propose that leiomodin 1 (LMOD1) is biphasic, with features of both TJs and GJs. LMOD1 not only promotes the activation of cancer-associated fibroblasts (CAFs) but also inhibits the Epithelial-mesenchymal transition (EMT) program in cancer cells. In conclusion, these findings demonstrate the molecular heterogeneity of CC and provide new insights into further understanding of TME heterogeneity.


Assuntos
Fibroblastos Associados a Câncer , Comunicação Celular , Neoplasias Colorretais , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Microambiente Tumoral , Animais , Humanos , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/genética , Transição Epitelial-Mesenquimal/genética , Junções Comunicantes/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Análise Espaço-Temporal , Junções Íntimas/metabolismo , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Autoantígenos/genética , Autoantígenos/metabolismo
14.
Opt Express ; 32(7): 11952-11963, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571031

RESUMO

Speckle with non-Rayleigh amplitude distribution has significant research value in imaging and measurement using structured illumination. However, existing speckle customizing schemes have been limited in generation speed due to the refresh rate of spatial light modulators (SLMs). In this work, we proposed a method to rapidly generate non-Rayleigh distributed speckle fields using a digital micro-mirror device (DMD). In contrast to SLMs that allow for gray-scale phase modulation, DMD is limited to binary amplitude control. To solve this limitation, we design a Gerchberg-Saxton-like algorithm based on super-pixel method, this algorithm enables the customization of non-Rayleigh speckle with arbitrary intensity probability density function. Statistical analyses of experimental results have demonstrated that the customized speckles exhibit excellent stability in their lateral statistical properties, while also maintaining consistent propagation characteristics with Rayleigh speckle in the longitudinal direction. This method provides a new approach for high-speed and arbitrary intensity speckle customization, holding potential applications in imaging, measurement, and encryption fields.

15.
Clin Endocrinol (Oxf) ; 100(3): 294-303, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38214116

RESUMO

This study aimed to evaluate whether there is a causal relationship between autoimmune thyroid disorders (AITDs) and telomere length (TL) in the European population and whether there is reverse causality. In this study, Mendelian randomization (MR) and colocalization analysis were conducted to assess the potential causal relationship between AITDs and TL using summary statistics from large-scale genome-wide association studies, followed by analysis of the relationship between TL and thyroid stimulating hormone and free thyroxine (FT4) to help interpret the findings. The inverse variance weighted (IVW) method was used to estimate the causal estimates. The weighted median, MR-Egger and leave-one-out methods were used as sensitivity analyses. The IVW method results showed a significant causal relationship between autoimmune hyperthyroidism and TL (ß = -1.93 × 10-2 ; p = 4.54 × 10-5 ). There was no causal relationship between autoimmune hypothyroidism and TL (ß = -3.99 × 10-3 ; p = 0.324). The results of the reverse MR analysis showed that genetically TL had a significant causal relationship on autoimmune hyperthyroidism (IVW: odds ratio (OR) = 0.49; p = 2.83 × 10-4 ) and autoimmune hypothyroidism (IVW: OR = 0.86; p = 7.46 × 10-3 ). Both horizontal pleiotropy and heterogeneity tests indicated the validity of our bidirectional MR study. Finally, colocalization analysis suggested that there were shared causal variants between autoimmune hyperthyroidism and TL, further highlighting the robustness of the results. In conclusion, autoimmune hyperthyroidism may accelerate telomere attrition, and telomere attrition is a causal factor for AITDs.


Assuntos
Doença de Graves , Doença de Hashimoto , Hipotireoidismo , Tireoidite Autoimune , Humanos , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Telômero/genética , Hipotireoidismo/genética
16.
Int Microbiol ; 27(2): 535-544, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37505307

RESUMO

Cajaninstilbene acid (CSA), longistylin A (LLA), and longistylin C (LLC) are three characteristic stilbenes isolated from pigeon pea. The objective of this study was to evaluate the antibacterial activity of these stilbenes against Staphylococcus aureus and even methicillin-resistant Staphylococcus aureus (MRSA) and test the possibility of inhibiting biofilm formation. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these stilbenes were evaluated. And the results showed that LLA was most effective against tested strains with MIC and MBC values of 1.56 µg/mL followed by LLC with MIC and MBC values of 3.12 µg/mL and 6.25 µg/mL as well as CSA with MIC and MBC values of 6.25 µg/mL and 6.25-12.5 µg/mL. Through growth curve and cytotoxicity analysis, the concentrations of these stilbenes were determined to be set at their respective 1/4 MIC in the follow-up research. In an anti-biofilm formation assay, these stilbenes were found to be effectively inhibited bacterial proliferation, biofilm formation, and key gene expressions related to the adhesion and virulence of MRSA. It is the first time that the anti-S. aureus and MRSA activities of the three stilbenes have been systematically reported. Conclusively, these findings provide insight into the anti-MRSA mechanism of stilbenes from pigeon pea, indicating these compounds may be used as antimicrobial agents or additives for food with health functions, and contribute to the development as well as application of pigeon pea in food science.


Assuntos
Cajanus , Staphylococcus aureus Resistente à Meticilina , Estilbenos , Antibacterianos/farmacologia , Estilbenos/farmacologia , Testes de Sensibilidade Microbiana , Anticorpos/farmacologia , Biofilmes
17.
Inorg Chem ; 63(9): 4152-4159, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38372260

RESUMO

The template-directed strategy has been extensively employed for the construction of supramolecular architectures. However, with the increase in the size and complexity of these structures, the synthesis difficulty of the templates escalates exponentially, thereby impeding the widespread application of this strategy. In this study, two truncated triangles T1 and T2 were successfully self-assembled through a novel segmented template strategy by segmenting the core triangular template into portions. Two metallo-organic ligands L2 and L3 were designed and synthesized by dividing the central stable triangle into three separate parts and incorporating them into the precursor ligands, which served as templates to guide the self-assembly process with ligands L1 and L4, respectively. The assembled structures were unambiguously characterized by multidimensional and multinuclear NMR (1H, COSY, NOESY), multidimensional mass spectrometry analysis (ESI-MS and TWIM-MS), and transmission electron microscopy (TEM). Moreover, we observed the formation of fiberlike nanotubes from single-molecule triangles by hierarchical self-assembly.

18.
Inorg Chem ; 63(16): 7442-7454, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38606439

RESUMO

As electrocatalysts, molecular catalysts with large aromatic systems (such as terpyridine, porphyrin, or phthalocyanine) have been widely applied in the CO2 reduction reaction (CO2RR). However, these monomeric catalysts tend to aggregate due to strong π-π interactions, resulting in limited accessibility of the active site. In light of these challenges, we present a novel strategy of active site isolation for enhancing the CO2RR. Six Ru(Tpy)2 were integrated into the skeleton of a metallo-organic supramolecule by stepwise self-assembly in order to form a rhombus-fused six-pointed star R1 with active site isolation. The turnover frequency (TOF) of R1 was as high as 10.73 s-1 at -0.6 V versus reversible hydrogen electrode (vs RHE), which is the best reported value so far at the same potential to our knowledge. Furthermore, by increasing the connector density on R1's skeleton, a more stable triangle-fused six-pointed star T1 was successfully synthesized. T1 exhibits exceptional stability up to 126 h at -0.4 V vs RHE and excellent TOF values of CO. The strategy of active site isolation and connector density increment significantly enhanced the catalytic activity by increasing the exposure of the active site. This work provides a starting point for the design of molecular catalysts and facilitates the development of a new generation of catalysts with a high catalytic performance.

19.
J Immunol ; 209(10): 2012-2021, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36426941

RESUMO

Germline-encoded pattern recognition receptors (PRRs) recognize molecules frequently found in pathogens (pathogen-associated molecular patterns [PAMPs]) during viral infection. This process induces production of IFNs, leading to expression of IFN-stimulated genes to establish a cellular antiviral state against viral infection. However, aberrant activation of the IFN system may cause immunopathological damage and systemic autoimmune diseases such as systemic lupus erythematosus. Stringent control of IFN signaling activation is critical for maintaining homoeostasis of the immune system; yet, the mechanisms responsible for its precise regulation remain to be elucidated. In this study, we identified that ring finger protein 215 (RNF215), a zinc finger protein, was upregulated by viral infection in human macrophages. In addition, we demonstrated that RNF215 inhibited the production of type I IFNs at least in part via interacting with p65, a subunit of NF-κB, and repressed the accumulation of NF-κB in the promoter region of IFNB1. Moreover, we found that the expression of RNF215 negatively correlated with type I IFNs in patients with systemic lupus erythematosus, indicating that RNF215 plays an important role in the pathogenesis of autoimmune diseases. Collectively, our data identified RNF215 as a key negative regulator of type I IFNs and suggested RNF215 as a potential target for intervention in diseases with aberrant IFN production.


Assuntos
Doenças Autoimunes , Lúpus Eritematoso Sistêmico , Humanos , Interferon Tipo I/biossíntese , NF-kappa B , Moléculas com Motivos Associados a Patógenos , Transdução de Sinais
20.
Anal Bioanal Chem ; 416(9): 2371-2387, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38319358

RESUMO

Fatty acids (FAs) have attracted many interests for their pivotal roles in many biological processes. Imbalance of FAs is related to a variety of diseases, which makes the measurement of them important in biological samples. Over the past two decades, mass spectrometry (MS) has become an indispensable technique for the analysis of FAs owing to its high sensitivity and precision. Due to complex matrix effect of biological samples and inherent poor ionization efficiency of FAs in MS, sample preparation including extraction and chemical derivatization prior to analysis are often employed. Here, we describe an updated overview of FA extraction techniques, as well as representative derivatization methods utilized in different MS platforms including gas chromatography-MS, liquid chromatography-MS, and mass spectrometry imaging based on different chain lengths of FAs. Derivatization strategies for the identification of double bond location in unsaturated FAs are also summarized and highlighted. The advantages, disadvantages, and prospects of these methods are compared and discussed. This review provides the development and valuable information for sample pretreatment approaches and qualitative and quantitative analysis of interested FAs using different MS-based platforms in complex biological matrices. Finally, the challenges of FA analysis are summarized and the future perspectives are prospected.


Assuntos
Ácidos Graxos Insaturados , Ácidos Graxos , Ácidos Graxos/análise , Espectrometria de Massas/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massa com Cromatografia Líquida
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