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1.
Angew Chem Int Ed Engl ; 63(18): e202402007, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38407551

RESUMO

Pathological hyperphosphorylation and aggregation of microtubule-associated Tau protein contribute to Alzheimer's Disease (AD) and other related tauopathies. Currently, no cure exists for Alzheimer's Disease. Aptamers offer significant potential as next-generation therapeutics in biotechnology and the treatment of neurological disorders. Traditional aptamer selection methods for Tau protein focus on binding affinity rather than interference with pathological Tau. In this study, we developed a new selection strategy to enrich DNA aptamers that bind to surviving monomeric Tau protein under conditions that would typically promote Tau aggregation. Employing this approach, we identified a set of aptamer candidates. Notably, BW1c demonstrates a high binding affinity (Kd=6.6 nM) to Tau protein and effectively inhibits arachidonic acid (AA)-induced Tau protein oligomerization and aggregation. Additionally, it inhibits GSK3ß-mediated Tau hyperphosphorylation in cell-free systems and okadaic acid-mediated Tau hyperphosphorylation in cellular milieu. Lastly, retro-orbital injection of BW1c tau aptamer shows the ability to cross the blood brain barrier and gain access to neuronal cell body. Through further refinement and development, these Tau aptamers may pave the way for a first-in-class neurotherapeutic to mitigate tauopathy-associated neurodegenerative disorders.


Assuntos
Doença de Alzheimer , Tauopatias , Proteínas tau , Humanos , Doença de Alzheimer/metabolismo , Neurônios/metabolismo , Ácido Okadáico/metabolismo , Ácido Okadáico/farmacologia , Ácido Okadáico/uso terapêutico , Fosforilação , Proteínas tau/antagonistas & inibidores , Proteínas tau/metabolismo , Tauopatias/tratamento farmacológico , Tauopatias/metabolismo , Tauopatias/patologia , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/farmacologia
2.
Mol Cancer ; 22(1): 43, 2023 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-36859240

RESUMO

B7-H3 (CD276), a member of the B7 family of proteins, is a key player in cancer progression. This immune checkpoint molecule is selectively expressed in both tumor cells and immune cells within the tumor microenvironment. In addition to its immune checkpoint function, B7-H3 has been linked to tumor cell proliferation, metastasis, and therapeutic resistance. Furthermore, its drastic difference in protein expression levels between normal and tumor tissues suggests that targeting B7-H3 with drugs would lead to cancer-specific toxicity, minimizing harm to healthy cells. These properties make B7-H3 a promising target for cancer therapy.Recently, important advances in B7-H3 research and drug development have been reported, and these new findings, including its involvement in cellular metabolic reprograming, cancer stem cell enrichment, senescence and obesity, have expanded our knowledge and understanding of this molecule, which is important in guiding future strategies for targeting B7-H3. In this review, we briefly discuss the biology and function of B7-H3 in cancer development. We emphasize more on the latest findings and their underlying mechanisms to reflect the new advances in B7-H3 research. In addition, we discuss the new improvements of B-H3 inhibitors in cancer drug development.


Assuntos
Desenvolvimento de Medicamentos , Fatores de Transcrição , Humanos , Proliferação de Células , Proteínas de Checkpoint Imunológico , Células-Tronco Neoplásicas , Antígenos B7
3.
Acta Radiol ; 64(9): 2636-2645, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37312525

RESUMO

BACKGROUND: Lymphovascular space invasion (LVSI) of endometrial cancer (EC) is a postoperative histological index, which is associated with lymph node metastases. A preoperative acknowledgement of LVSI status might aid in treatment decision-making. PURPOSE: To explore the utility of multiparameter magnetic resonance imaging (MRI) and radiomic features obtained from intratumoral and peritumoral regions for predicting LVSI in endometrioid adenocarcinoma (EEA). MATERIAL AND METHODS: A total of 334 EEA tumors were retrospectively analyzed. Axial T2-weighted (T2W) imaging and apparent diffusion coefficient (ADC) mapping were conducted. Intratumoral and peritumoral regions were manually annotated as the volumes of interest (VOIs). A support vector machine was applied to train the prediction models. Multivariate logistic regression analysis was used to develop a nomogram based on clinical and tumor morphological parameters and the radiomics score (RadScore). The predictive performance of the nomogram was assessed by the area under the receiver operator characteristic curve (AUC) in the training and validation cohorts. RESULTS: Among the features obtained from different imaging modalities (T2W imaging and ADC mapping) and VOIs, the RadScore had the best performance in predicting LVSI classification (AUCtrain = 0.919, and AUCvalidation = 0.902). The nomogram based on age, CA125, maximum anteroposterior tumor diameter on sagittal T2W images, tumor area ratio, and RadScore was established to predict LVSI had AUC values in the training and validation cohorts of 0.962 (sensitivity 94.0%, specificity 86.0%) and 0.965 (sensitivity 90.0%, specificity 85.3%), respectively. CONCLUSION: The intratumoral and peritumoral imaging features were complementary, and the MRI-based radiomics nomogram might serve as a non-invasive biomarker to preoperatively predict LVSI in patients with EEA.


Assuntos
Carcinoma Endometrioide , Nomogramas , Feminino , Humanos , Estudos Retrospectivos , Carcinoma Endometrioide/diagnóstico por imagem , Carcinoma Endometrioide/cirurgia , Imageamento por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética
4.
J Cell Mol Med ; 25(17): 8087-8094, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34312998

RESUMO

Inflammatory responses play a vital role in the onset and development of atherosclerosis, and throughout the entire process of the chronic disease. The inflammatory responses in atherosclerosis are mainly mediated by the NLRP3 inflammasome and its downstream inflammatory factors. As a powerful anti-inflammatory medicine, colchicine has a history of more than 200 years in clinical application and is the first-choice treatment for immune diseases such as gout and familial Mediterranean fever. In atherosclerosis, colchicine can inhibit the assembly and activation of NLRP3 inflammasome via various mechanisms to effectively reduce the expression of inflammatory factors, thereby reducing the inflammation. Recent clinical trials show that a low dose of colchicine (0.5 mg per day) has a certain protective effect in stable angina patients or those with acute myocardial infarction after PCI. This article summarizes and discusses the mechanisms of colchicine in the treatment of atherosclerosis and the latest research progress.


Assuntos
Anti-Inflamatórios , Aterosclerose/tratamento farmacológico , Colchicina , Inflamassomos/metabolismo , Inflamação/tratamento farmacológico , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/farmacologia , Colchicina/administração & dosagem , Colchicina/farmacologia , Humanos , Placa Aterosclerótica
5.
Chembiochem ; 22(4): 754-759, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33051959

RESUMO

Functional nucleic acids (FNAs) are garnering tremendous interest owing to their high modularity and unique bioactivity. Three-dimensional FNAs have been developed to overcome the issues of nuclease degradation and limited cell uptake. We have developed a new facile approach to the synthesis of multiple three-dimensional FNA nanostructures by harnessing photo-polymerization-induced self-assembly. Sgc8 aptamer and CpG oligonucleotide were modified as macro chain-transfer reagents to mediate in situ polymerization and self-assembly. Diverse structures, including micelles, rods, and short worms, afford these two FNAs afford these two FNAs with higher nuclease resistance in serum serum, greater cellular uptake efficiency, and increased bioactivity.


Assuntos
Aptâmeros de Nucleotídeos/química , Nanoestruturas/química , Ácidos Nucleicos/metabolismo , Oligodesoxirribonucleotídeos/química , Polímeros/química , Ilhas de CpG , Metacrilatos/química , Micelas , Ácidos Nucleicos/química , Polimerização
6.
Cancer Metastasis Rev ; 38(1-2): 157-164, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30997670

RESUMO

The Warburg effect is prevalent in human cancer. Accordingly, most cancer cells display highly elevated glycolysis without proportionally increasing pyruvate oxidation. The metastatic process imposes strong selective pressure on cancer cells, and metastasizing cancer cells experience heightened oxidative stress. By constraining mitochondrial oxidative metabolism, the Warburg effect helps cancer cells to minimize oxidative stress, thereby facilitating metastatic dissemination. The PGC1α transcriptional coactivator is a central coordinator of oxidative metabolism. While promoting oxidative metabolism and reversing the Warburg effect, PGC1α critically activates antioxidant genes and protects cells against oxidative damage. Therefore, depending on the context, PGC1α may promote or suppress tumor metastasis. Cancer cells generally retain metabolic flexibility and can resist antiglycolysis treatment by undergoing metabolic reprogramming. Synthetic lethal combination therapies are thus essential to attack the liabilities of the Warburg metabolism for therapeutic benefit.


Assuntos
Neoplasias/metabolismo , Neoplasias/patologia , Animais , Glicólise , Humanos , Metástase Neoplásica , Fosforilação Oxidativa , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo
7.
J Cell Biochem ; 119(1): 712-722, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28657656

RESUMO

Transcription factor TFII-I is a multifunctional protein implicated in the regulation of cell cycle and stress-response genes. Previous studies have shown that a subset of TFII-I associated genomic sites contained DNA-binding motifs for E2F family transcription factors. We analyzed the co-association of TFII-I and E2Fs in more detail using bioinformatics, chromatin immunoprecipitation, and co-immunoprecipitation experiments. The data show that TFII-I interacts with E2F transcription factors. Furthermore, TFII-I, E2F4, and E2F6 interact with DNA-regulatory elements of several genes implicated in the regulation of the cell cycle, including DNMT1, HDAC1, CDKN1C, and CDC27. Inhibition of TFII-I expression led to a decrease in gene expression and in the association of E2F4 and E2F6 with these gene loci in human erythroleukemia K562 cells. Finally, TFII-I deficiency reduced the proliferation of K562 cells and increased the sensitivity toward doxorubicin toxicity. The results uncover novel interactions between TFII-I and E2Fs and suggest that TFII-I mediates E2F function at specific cell cycle genes.


Assuntos
Proteínas de Ciclo Celular/genética , Fatores de Transcrição E2F/metabolismo , Fatores de Transcrição TFII/metabolismo , Ciclo Celular , Proliferação de Células , Imunoprecipitação da Cromatina , Biologia Computacional/métodos , Fatores de Transcrição E2F/genética , Humanos , Células K562 , Regiões Promotoras Genéticas , Ligação Proteica , Fatores de Transcrição TFII/genética
8.
Mol Med ; 22: 192-201, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26835698

RESUMO

Cardiac hypertrophy can be broadly classified as either physiological or pathological. Physiological stimuli such as exercise cause adaptive cardiac hypertrophy and normal heart function. Pathological stimuli including hypertension and aortic valvular stenosis cause maladaptive cardiac remodeling and ultimately heart failure. Syndecan-4 (synd4) is a transmembrane proteoglycan identified as being involved in cardiac adaptation after injury, but whether it takes part in physiological cardiac hypertrophy is unclear. We observed upregulation of synd4 in exercise-induced hypertrophic myocardium. To evaluate the role of synd4 in the physiological form of cardiac hypertrophy, mice lacking synd4 (synd4-/-) were exercised by swimming for 4 wks. Ultrasonic cardiogram (UCG) and histological analysis revealed that swimming induced the hypertrophic phenotype but was blunted in synd4-/- compared with wild-type (WT) mice. The swimming-induced activation of Akt, a key molecule in physiological hypertrophy was also more decreased than in WT controls. In cultured cardiomyocytes, synd4 overexpression could induce cell enlargement, protein synthesis and distinct physiological molecular alternation. Akt activation also was observed in synd4-overexpressed cardiomyocytes. Furthermore, inhibition of protein kinase C (PKC) prevented the synd4-induced hypertrophic phenotype and Akt phosphorylation. This study identified an essential role of synd4 in mediation of physiological cardiac hypertrophy.

9.
J Biol Chem ; 288(9): 6238-47, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23349461

RESUMO

SFMBT1 belongs to the malignant brain tumor domain-containing chromatin reader family that recognizes repressive histone marks and represses transcription. The biological functions and molecular basis underlying SFMBT1-mediated transcriptional repression are poorly elucidated. Here, our proteomic analysis revealed that SFMBT1 is associated with multiple transcriptional corepressor complexes, including CtBP/LSD1/HDAC complexes, polycomb repressive complexes, and malignant brain tumor family proteins, that collectively contribute to SFMBT1 repressor activity. During myogenesis, Sfmbt1 represses myogenic differentiation of cultured and primary myoblasts. Mechanistically, Sfmbt1 interacts with MyoD and mediates epigenetic silencing of MyoD target genes via recruitment of its associated corepressors and subsequent induction of epigenetic modifications and chromatin compaction. Therefore, our study identified novel mechanisms accounting for SFMBT1-mediated transcription repression and revealed an essential role of Sfmbt1 in regulating MyoD-mediated transcriptional silencing that is required for the maintenance of undifferentiated states of myogenic progenitor cells.


Assuntos
Montagem e Desmontagem da Cromatina/fisiologia , Inativação Gênica/fisiologia , Desenvolvimento Muscular/fisiologia , Proteínas Repressoras/metabolismo , Transcrição Gênica/fisiologia , Linhagem Celular , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Humanos , Proteína MyoD/genética , Proteína MyoD/metabolismo , Proteômica/métodos , Proteínas Repressoras/genética
10.
J Biol Chem ; 288(38): 27680-27691, 2013 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-23928305

RESUMO

Chromatin readers decipher the functional readouts of histone modifications by recruiting specific effector complexes for subsequent epigenetic reprogramming. The LSD1 (also known as KDM1A) histone demethylase complex modifies chromatin and represses transcription in part by catalyzing demethylation of dimethylated histone H3 lysine 4 (H3K4me2), a mark for active transcription. However, none of its currently known subunits recognizes methylated histones. The Snai1 family transcription factors are central drivers of epithelial-to-mesenchymal transition (EMT) by which epithelial cells acquire enhanced invasiveness. Snai1-mediated transcriptional repression of epithelial genes depends on its recruitment of the LSD1 complex and ensuing demethylation of H3K4me2 at its target genes. Through biochemical purification, we identified the MBT domain-containing protein SFMBT1 as a novel component of the LSD1 complex associated with Snai1. Unlike other mammalian MBT domain proteins characterized to date that selectively recognize mono- and dimethylated lysines, SFMBT1 binds di- and trimethyl H3K4, both of which are enriched at active promoters. We show that SFMBT1 is essential for Snai1-dependent recruitment of LSD1 to chromatin, demethylation of H3K4me2, transcriptional repression of epithelial markers, and induction of EMT by TGFß. Carcinogenic metal nickel is a widespread environmental and occupational pollutant. Nickel alters gene expression and induces EMT. We demonstrate the nickel-initiated effects are dependent on LSD1-SFMBT1-mediated chromatin modification. Furthermore, in human cancer, expression of SFMBT1 is associated with mesenchymal markers and unfavorable prognosis. These results highlight a critical role of SFMBT1 in epigenetic regulation, EMT, and cancer.


Assuntos
Cromatina/metabolismo , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal , Histona Desmetilases/metabolismo , Histonas/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Proteínas Repressoras/metabolismo , Carcinógenos/farmacologia , Cromatina/genética , Cromatina/patologia , Células Epiteliais/patologia , Células HEK293 , Histona Desmetilases/genética , Histonas/genética , Humanos , Metilação , Proteínas de Neoplasias/genética , Neoplasias/genética , Neoplasias/patologia , Níquel/efeitos adversos , Níquel/farmacologia , Proteínas Repressoras/genética , Fatores de Transcrição da Família Snail , Oligoelementos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
11.
EMBO J ; 29(5): 969-80, 2010 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-20075865

RESUMO

Autophagy is primarily considered a non-selective degradation process induced by starvation. Nutrient-independent basal autophagy, in contrast, imposes intracellular QC by selective disposal of aberrant protein aggregates and damaged organelles, a process critical for suppressing neurodegenerative diseases. The molecular mechanism that distinguishes these two fundamental autophagic responses, however, remains mysterious. Here, we identify the ubiquitin-binding deacetylase, histone deacetylase-6 (HDAC6), as a central component of basal autophagy that targets protein aggregates and damaged mitochondria. Surprisingly, HDAC6 is not required for autophagy activation; rather, it controls the fusion of autophagosomes to lysosomes. HDAC6 promotes autophagy by recruiting a cortactin-dependent, actin-remodelling machinery, which in turn assembles an F-actin network that stimulates autophagosome-lysosome fusion and substrate degradation. Indeed, HDAC6 deficiency leads to autophagosome maturation failure, protein aggregate build-up, and neurodegeneration. Remarkably, HDAC6 and F-actin assembly are completely dispensable for starvation-induced autophagy, uncovering the fundamental difference of these autophagic modes. Our study identifies HDAC6 and the actin cytoskeleton as critical components that define QC autophagy and uncovers a novel regulation of autophagy at the level of autophagosome-lysosome fusion.


Assuntos
Autofagia/fisiologia , Histona Desacetilases/metabolismo , Fagossomos/metabolismo , Ubiquitina/metabolismo , Actinas/metabolismo , Animais , Animais Geneticamente Modificados , Autofagia/genética , Linhagem Celular , Drosophila , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Desacetilase 6 de Histona , Histona Desacetilases/genética , Imuno-Histoquímica , Lisossomos/genética , Lisossomos/metabolismo , Camundongos , Microscopia de Fluorescência , Fagossomos/genética
12.
Proc Natl Acad Sci U S A ; 108(37): 15231-6, 2011 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-21896759

RESUMO

Angiogenesis is meticulously controlled by a fine balance between positive and negative regulatory activities. Vascular endothelial growth factor (VEGF) is a predominant angiogenic factor and its dosage is precisely regulated during normal vascular formation. In cancer, VEGF is commonly overproduced, resulting in abnormal neovascularization. VEGF is induced in response to various stimuli including hypoxia; however, very little is known about the mechanisms that confine its induction to ensure proper angiogenesis. Chromatin insulation is a key transcription mechanism that prevents promiscuous gene activation by interfering with the action of enhancers. Here we show that the chromatin insulator-binding factor CTCF binds to the proximal promoter of VEGF. Consistent with the enhancer-blocking mode of chromatin insulators, CTCF has little effect on basal expression of VEGF but specifically affects its activation by enhancers. CTCF knockdown cells are sensitized for induction of VEGF and exhibit elevated proangiogenic potential. Cancer-derived CTCF missense mutants are mostly defective in blocking enhancers at the VEGF locus. Moreover, during mouse retinal development, depletion of CTCF causes excess angiogenesis. Therefore, CTCF-mediated chromatin insulation acts as a crucial safeguard against hyperactivation of angiogenesis.


Assuntos
Cromatina/metabolismo , Elementos Isolantes/genética , Neovascularização Patológica/genética , Proteínas Repressoras/metabolismo , Dedos de Zinco/genética , Animais , Fator de Ligação a CCCTC , Linhagem Celular , Elementos Facilitadores Genéticos/genética , Genes Reporter/genética , Humanos , Camundongos , Neoplasias/irrigação sanguínea , Neoplasias/patologia , Neovascularização Patológica/patologia , Regiões Promotoras Genéticas/genética , Ligação Proteica , Retina/crescimento & desenvolvimento , Retina/patologia , Transcrição Gênica , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
13.
J Immunother Cancer ; 12(7)2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39060025

RESUMO

BACKGROUND: The high metastasis rate is one of the main reasons for the poor prognosis of patients with hepatocellular carcinoma (HCC). Coagulation factor Xa (FXa) and its receptor proteinase-activated receptor-2 (PAR-2) proven to promote tumor metastasis in other forms of cancer. Here, we explore the role and mechanism of FXa in the regulation of resistance of anoikis and immune escape of HCC. METHODS: In vitro and in vivo experiments were conducted to explore the role of FXa in HCC metastasis and its potential mechanism. The effects of FXa inhibitor rivaroxaban on HCC immunotherapy were evaluated using intrahepatic metastasis animal models and clinical trial (No. ChiCTR20000040540). We investigated the potential of FXa inhibition as a treatment for HCC. RESULTS: FXa was highly expressed in HCC and promoted metastasis by activating PAR-2. Mechanistically, FXa-activated PAR-2 endows HCC cells with the ability of anoikis resistance to survive in the circulating blood by inhibiting the extrinsic apoptosis pathway. Furthermore, suspension stimulation-induced phosphorylation of STAT2, which promotes programmed death-ligand 1 (PD-L1) transcription and inhibits the antitumor effects of immune cells by inhibiting the infiltration of CD8+T cells in tumors and the levels of secreted cytokines. In vivo inhibition of FXa with rivaroxaban reduced HCC metastasis by decreasing PD-L1 expression and exhausting tumor-infiltrating lymphocytes. Notably, the combination of rivaroxaban and anti-programmed death-1 monoclonal antibody (anti-PD-1) programmed Death-1 monoclonal antibody (anti-PD-1) induced synergistic antitumor effects in animal models. Most importantly, rivaroxaban improved the objective response rate of patients with HCC to immune checkpoint inhibitors and prolonged overall survival time. CONCLUSIONS: FXa-activated PAR-2 promotes anoikis resistance and immune escape in HCC, suggesting the potential for combining coagulation inhibitors and PD-1/PD-L1 immune checkpoint blockade to enhance the therapeutic efficacy of HCC.


Assuntos
Anoikis , Antígeno B7-H1 , Carcinoma Hepatocelular , Imunoterapia , Neoplasias Hepáticas , Receptor PAR-2 , Evasão Tumoral , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/patologia , Humanos , Receptor PAR-2/metabolismo , Animais , Camundongos , Imunoterapia/métodos , Antígeno B7-H1/metabolismo , Antígeno B7-H1/antagonistas & inibidores , Fator Xa/metabolismo , Fator Xa/farmacologia , Fator Xa/uso terapêutico , Masculino , Feminino , Linhagem Celular Tumoral , Inibidores do Fator Xa/farmacologia , Inibidores do Fator Xa/uso terapêutico
14.
Nat Chem ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858518

RESUMO

Adding synthetic nucleotides to DNA increases the linear information density of DNA molecules. Here we report that it also can increase the diversity of their three-dimensional folds. Specifically, an additional nucleotide (dZ, with a 5-nitro-6-aminopyridone nucleobase), placed at twelve sites in a 23-nucleotides-long DNA strand, creates a fairly stable unimolecular structure (that is, the folded Z-motif, or fZ-motif) that melts at 66.5 °C at pH 8.5. Spectroscopic, gel and two-dimensional NMR analyses show that the folded Z-motif is held together by six reverse skinny dZ-:dZ base pairs, analogous to the crystal structure of the free heterocycle. Fluorescence tagging shows that the dZ-:dZ pairs join parallel strands in a four-stranded compact down-up-down-up fold. These have two possible structures: one with intercalated dZ-:dZ base pairs, the second without intercalation. The intercalated structure would resemble the i-motif formed by dC:dC+-reversed pairing at pH ≤ 6.5. This fZ-motif may therefore help DNA form compact structures needed for binding and catalysis.

15.
Bone ; 170: 116709, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36863499

RESUMO

FBXO11 is the substrate-recognition component of a ubiquitin ligase complex called SKP1-cullin-F-boxes. The role of FBXO11 in bone development is unexplored. In this study, we reported a novel mechanism of how bone development is regulated by FBXO11. FBXO11 gene knockdown by lentiviral transduction in mouse pre-osteoblast MC3T3-E1 cells leads to reduced osteogenic differentiation, while overexpressing FBXO11 accelerates their osteogenic differentiation in vitro. Furthermore, we generated two osteoblastic-specific FBXO11 conditional knockout mouse models, Col1a1-ERT2-FBXO11KO and Bglap2-FBXO11KO mice. In both conditional FBXO11KO mouse models, we found FBXO11 deficiency inhibits normal bone growth, in which the osteogenic activity in FBXO11cKO mice is reduced, while osteoclastic activity is not significantly changed. Mechanistically, we found FBXO11 deficiency leads to Snail1 protein accumulation in osteoblasts, leading to suppression of osteogenic activity and inhibition of bone matrix mineralization. FBXO11 knockdown in MC3T3-E1 cells reduced Snail1 protein ubiquitination and increased Snail1 protein accumulation in the cells, which eventually inhibited osteogenic differentiation. In conclusion, FBXO11 deficiency in osteoblasts inhibits bone formation through Snail1 accumulation, inhibiting osteogenic activity and bone mineralization.


Assuntos
Calcificação Fisiológica , Osteogênese , Animais , Camundongos , Osteogênese/fisiologia , Diferenciação Celular , Osteoclastos , Osteoblastos/metabolismo
16.
Theranostics ; 13(7): 2281-2300, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37153737

RESUMO

Heat Shock Factor 1 (HSF1) is a master regulator of heat shock responsive signaling. In addition to playing critical roles in cellular heat shock response, emerging evidence suggests that HSF1 also regulates a non-heat shock responsive transcriptional network to handle metabolic, chemical, and genetic stress. The function of HSF1 in cellular transformation and cancer development has been extensively studied in recent years. Due to important roles for HSF1 for coping with various stressful cellular states, research on HSF1 has been very active. New functions and molecular mechanisms underlying these functions have been continuously discovered, providing new targets for novel cancer treatment strategies. In this article, we review the essential roles and mechanisms of HSF1 action in cancer cells, focusing more on recently discovered functions and their underlying mechanisms to reflect the new advances in cancer biology. In addition, we emphasize new advances with regard to HSF1 inhibitors for cancer drug development.


Assuntos
Neoplasias , Fatores de Transcrição , Humanos , Fatores de Transcrição/metabolismo , Fatores de Transcrição de Choque Térmico/genética , Fatores de Transcrição de Choque Térmico/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Transformação Celular Neoplásica , Resposta ao Choque Térmico
17.
Comput Intell Neurosci ; 2022: 8307398, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35795728

RESUMO

Digitalization brings challenges and new opportunities to the development of landscape gardening, "smart gardening," which is a product of landscape gardening in response to the development of the digital era. Based on the multimodal intelligent computing method and deep neural network machine learning algorithm, this paper adopts "digital landscape design logic" to analyze and research smart gardens and digital design. The digital landscape design process and methods are discussed based on design logic, design basis, environment analysis, and results presentation, and the greenery maintenance scheduling system is constructed. The paper focuses on the digital implementation of the environmental analysis of the site and uses Rhino software and Grasshopper visual programming language to build parametric logic, establish parametric analysis models, and conduct a comprehensive analysis of the current environment. The main theme of the whole paper is a logical approach to digital landscape design for smart gardens, using digital technology tools from the perspective of smart garden thinking, combining quantitative analysis and qualitative design, and intervening in digital landscape garden planning and design to explore the application of digital technology and tools.


Assuntos
Aprendizado de Máquina , Redes Neurais de Computação , Algoritmos , Software
18.
Chemosphere ; 299: 134421, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35346738

RESUMO

Zinc oxide nanoparticles (ZnO NPs) dissolution is a critical process for the transformation and toxicity of ZnO NPs in aquatic environments. However, the effect of microplastics (MPs) on dissolution and toxicity of ZnO NPs under sunlight irradiation is still lacking. Herein, the dramatic increase in sunlight-induced ZnO NPs dissolution by polystyrene (PS) MPs was proven, which was attributed to the increase in h+-dependent and proton-dependent ZnO NPs dissolution by PS MPs, yielding 1O2 generation inhibition and acid release, respectively. The sizes, functional groups and aging status of PS MPs and pH were characteristic ZnO NPs dissolution through modifying 1O2, •OH and O2•- generation and acid release. Furthermore, the ZnO NPs dissolution affected by PS MPs also occurred in three realistic water samples, which were mainly governed by dissolved organic matter (DOM) and CO32-, rather than Cl- or SO42-. The PS MPs (1 µg/mL) dramatically altered the Zn2+:ZnO ratio in ZnO NPs suspension after 96 h of sunlight irradiation and presented vehicle effects on Zn2+, which in turn significantly increased the ion-related toxicity of ZnO NPs to Daphnia magna. Based on the PS MPs enhanced dissolution and toxicity of ZnO NPs, the effects of PS MPs on the environmental risk assessment of ZnO NPs should be seriously considered in freshwater environments under sunlight irradiation.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Óxido de Zinco , Microplásticos , Nanopartículas/toxicidade , Plásticos , Poliestirenos/toxicidade , Solubilidade , Luz Solar , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade
19.
Mater Today Bio ; 14: 100233, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35280330

RESUMO

Hemostatic materials are generally applied in surgical operations for cancer, but their effects on the growth and recurrence of tumors are unclear. Herein, three commonly used naturally derived hemostatic materials, gelatin sponge, Surgicel (oxidized regenerated cellulose), and biopaper (mixture of sodium hyaluronate and carboxymethyl chitosan), were cocultured with A549 human lung adenocarcinoma cells in vitro. Furthermore, the performance of hemostatic materials and the tumorigenicity of the materials with A549 â€‹cells were observed after subcutaneous implantation into BALB/c mice. The in vitro results showed that biopaper was dissolved quickly, with the highest cell numbers at 2 and 4 days of culture. Gelatin sponges retained their structure and elicited the least cell infiltration during the 2- to 10-day culture. Surgicel partially dissolved and supported cell growth over time. The in vivo results showed that biopaper degraded rapidly and elicited an acute Th1 lymphocyte reaction at 3 days after implantation, which was decreased at 7 days after implantation. The gelatin sponge resisted degradation and evoked a hybrid M1/M2 macrophage reaction at 7-21 days after implantation, and a protumor M2d subset was confirmed. Surgicel resisted early degradation and caused obvious antitumor M2a macrophage reactions. Mice subjected to subcutaneous implantation of A549 â€‹cells and hemostatic materials in the gelatin sponge group had the largest tumor volumes and the shortest overall survival (OS), while the Surgicel and the biopaper group had the smallest volumes and the longest OS. Therefore, although gelatin sponges exhibited cytotoxicity to A549 â€‹cells in vitro, they promoted the growth of A549 â€‹cells in vivo, which was related to chronic M2d macrophage reaction. Surgicel and biopaper inhibited A549 â€‹cell growth in vivo, which is associated with chronic M2a macrophage reaction or acute Th1 lymphocyte reaction.

20.
Cells ; 11(14)2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35883651

RESUMO

Epithelial-mesenchymal transition (EMT) is implicated in tumor metastasis and therapeutic resistance. It remains a challenge to target cancer cells that have undergone EMT. The Snail family of key EMT-inducing transcription factors directly binds to and transcriptionally represses not only epithelial genes but also a myriad of additional genomic targets that may carry out significant biological functions. Therefore, we reasoned that EMT inherently causes various concomitant phenotypes, some of which may create targetable vulnerabilities for cancer treatment. In the present study, we found that Snail transcription factors bind to the promoters of multiple genes encoding subunits of the AMP-activated protein kinase (AMPK) complex, and expression of AMPK genes was markedly downregulated by EMT. Accordingly, high AMPK expression in tumors correlated with epithelial cell markers and low AMPK expression in tumors was strongly associated with adverse prognosis. AMPK is the principal sensor of cellular energy status. In response to energy stress, AMPK is activated and critically reprograms cellular metabolism to restore energy homeostasis and maintain cell survival. We showed that activation of AMPK by energy stress was severely impaired by EMT. Consequently, EMT cancer cells became hypersensitive to a variety of energy stress conditions and primarily underwent pyroptosis, a regulated form of necrotic cell death. Collectively, the study suggests that EMT impedes the activation of AMPK signaling induced by energy stress and sensitizes cancer cells to pyroptotic cell death under energy stress conditions. Therefore, while EMT promotes malignant progression, it concurrently induces collateral vulnerabilities that may be therapeutically exploited.


Assuntos
Transição Epitelial-Mesenquimal , Neoplasias , Piroptose , Proteínas Quinases Ativadas por AMP/metabolismo , Transição Epitelial-Mesenquimal/genética , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Fatores de Transcrição da Família Snail , Estresse Fisiológico
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