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1.
Cell ; 185(20): 3823-3837.e23, 2022 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-36179672

RESUMO

Biochemical processes often require spatial regulation and specific microenvironments. The general lack of organelles in bacteria limits the potential of bioengineering complex intracellular reactions. Here, we demonstrate synthetic membraneless organelles in Escherichia coli termed transcriptionally engineered addressable RNA solvent droplets (TEARS). TEARS are assembled from RNA-binding protein recruiting domains fused to poly-CAG repeats that spontaneously drive liquid-liquid phase separation from the bulk cytoplasm. Targeting TEARS with fluorescent proteins revealed multilayered structures with composition and reaction robustness governed by non-equilibrium dynamics. We show that TEARS provide organelle-like bioprocess isolation for sequestering biochemical pathways, controlling metabolic branch points, buffering mRNA translation rates, and scaffolding protein-protein interactions. We anticipate TEARS to be a simple and versatile tool for spatially controlling E. coli biochemistry. Particularly, the modular design of TEARS enables applications without expression fine-tuning, simplifying the design-build-test cycle of bioengineering.


Assuntos
Escherichia coli , Organelas , Escherichia coli/genética , Organelas/metabolismo , RNA/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Solventes/análise , Solventes/metabolismo
2.
Mol Cell ; 84(5): 938-954.e8, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38272024

RESUMO

Phase separation is a vital mechanism that mediates the formation of biomolecular condensates and their functions. Necroptosis is a lytic form of programmed cell death mediated by RIPK1, RIPK3, and MLKL downstream of TNFR1 and has been implicated in mediating many human diseases. However, whether necroptosis is regulated by phase separation is not yet known. Here, we show that upon the induction of necroptosis and recruitment by the adaptor protein TAX1BP1, PARP5A and its binding partner RNF146 form liquid-like condensates by multivalent interactions to perform poly ADP-ribosylation (PARylation) and PARylation-dependent ubiquitination (PARdU) of activated RIPK1 in mouse embryonic fibroblasts. We show that PARdU predominantly occurs on the K376 residue of mouse RIPK1, which promotes proteasomal degradation of kinase-activated RIPK1 to restrain necroptosis. Our data demonstrate that PARdU on K376 of mouse RIPK1 provides an alternative cell death checkpoint mediated by phase separation-dependent control of necroptosis by PARP5A and RNF146.


Assuntos
Necroptose , Separação de Fases , Animais , Camundongos , Apoptose/fisiologia , Morte Celular , Fibroblastos/metabolismo , Necroptose/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
3.
Mol Cell ; 75(6): 1188-1202.e11, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31399345

RESUMO

The maternal-to-zygotic transition (MZT) is a conserved and fundamental process during which the maternal environment is converted to an environment of embryonic-driven development through dramatic reprogramming. However, how maternally supplied transcripts are dynamically regulated during MZT remains largely unknown. Herein, through genome-wide profiling of RNA 5-methylcytosine (m5C) modification in zebrafish early embryos, we found that m5C-modified maternal mRNAs display higher stability than non-m5C-modified mRNAs during MZT. We discovered that Y-box binding protein 1 (Ybx1) preferentially recognizes m5C-modified mRNAs through π-π interactions with a key residue, Trp45, in Ybx1's cold shock domain (CSD), which plays essential roles in maternal mRNA stability and early embryogenesis of zebrafish. Together with the mRNA stabilizer Pabpc1a, Ybx1 promotes the stability of its target mRNAs in an m5C-dependent manner. Our study demonstrates an unexpected mechanism of RNA m5C-regulated maternal mRNA stabilization during zebrafish MZT, highlighting the critical role of m5C mRNA modification in early development.


Assuntos
5-Metilcitosina/metabolismo , Embrião não Mamífero/embriologia , Desenvolvimento Embrionário/fisiologia , Estabilidade de RNA/fisiologia , RNA Mensageiro Estocado/metabolismo , Peixe-Zebra/embriologia , Animais , Células HeLa , Humanos , Camundongos , RNA Mensageiro Estocado/genética , Peixe-Zebra/genética
4.
Nature ; 587(7832): 133-138, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32968279

RESUMO

Cell death in human diseases is often a consequence of disrupted cellular homeostasis. If cell death is prevented without restoring cellular homeostasis, it may lead to a persistent dysfunctional and pathological state. Although mechanisms of cell death have been thoroughly investigated1-3, it remains unclear how homeostasis can be restored after inhibition of cell death. Here we identify TRADD4-6, an adaptor protein, as a direct regulator of both cellular homeostasis and apoptosis. TRADD modulates cellular homeostasis by inhibiting K63-linked ubiquitination of beclin 1 mediated by TRAF2, cIAP1 and cIAP2, thereby reducing autophagy. TRADD deficiency inhibits RIPK1-dependent extrinsic apoptosis and proteasomal stress-induced intrinsic apoptosis. We also show that the small molecules ICCB-19 and Apt-1 bind to a pocket on the N-terminal TRAF2-binding domain of TRADD (TRADD-N), which interacts with the C-terminal domain (TRADD-C) and TRAF2 to modulate the ubiquitination of RIPK1 and beclin 1. Inhibition of TRADD by ICCB-19 or Apt-1 blocks apoptosis and restores cellular homeostasis by activating autophagy in cells with accumulated mutant tau, α-synuclein, or huntingtin. Treatment with Apt-1 restored proteostasis and inhibited cell death in a mouse model of proteinopathy induced by mutant tau(P301S). We conclude that pharmacological targeting of TRADD may represent a promising strategy for inhibiting cell death and restoring homeostasis to treat human diseases.


Assuntos
Apoptose/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Proteína de Domínio de Morte Associada a Receptor de TNF/antagonistas & inibidores , Proteína de Domínio de Morte Associada a Receptor de TNF/metabolismo , Animais , Autofagia/efeitos dos fármacos , Proteína 3 com Repetições IAP de Baculovírus/metabolismo , Proteína Beclina-1/química , Proteína Beclina-1/metabolismo , Bortezomib/antagonistas & inibidores , Bortezomib/farmacologia , Linhagem Celular , Humanos , Proteína Huntingtina/metabolismo , Proteínas Inibidoras de Apoptose/metabolismo , Masculino , Camundongos , Modelos Moleculares , Emaranhados Neurofibrilares/metabolismo , Proteoma/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/química , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Proteína de Domínio de Morte Associada a Receptor de TNF/química , Proteína de Domínio de Morte Associada a Receptor de TNF/deficiência , Fator 2 Associado a Receptor de TNF/metabolismo , Ubiquitinação , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismo
5.
Proc Natl Acad Sci U S A ; 120(39): e2308079120, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37733743

RESUMO

TAK1 is a key modulator of both NF-κB signaling and RIPK1. In TNF signaling pathway, activation of TAK1 directly mediates the phosphorylation of IKK complex and RIPK1. In a search for small molecule activators of RIPK1-mediated necroptosis, we found R406/R788, two small molecule analogs that could promote sustained activation of TAK1. Treatment with R406 sensitized cells to TNF-mediated necroptosis and RIPK1-dependent apoptosis by promoting sustained RIPK1 activation. Using click chemistry and multiple biochemical binding assays, we showed that treatment with R406 promotes the activation of TAK1 by directly binding to TAK1, independent of its original target Syk kinase. Treatment with R406 promoted the ubiquitination of TAK1 and the interaction of activated TAK1 with ubiquitinated RIPK1. Finally, we showed that R406/R788 could promote the cancer-killing activities of TRAIL in vitro and in mouse models. Our studies demonstrate the possibility of developing small molecule TAK1 activators to potentiate the effect of TRAIL as anticancer therapies.


Assuntos
Apoptose , Neoplasias , Animais , Camundongos , Morte Celular , Citosol , Neoplasias/tratamento farmacológico , Neoplasias/genética , Ubiquitinação
6.
Proc Natl Acad Sci U S A ; 119(44): e2214227119, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36279464

RESUMO

LUBAC-mediated linear ubiquitination plays a pivotal role in regulation of cell death and inflammatory pathways. Genetic deficiency in LUBAC components leads to severe immune dysfunction or embryonic lethality. LUBAC has been extensively studied for its role in mediating TNF signaling. However, Tnfr1 knockout is not able to fully rescue the embryonic lethality of LUBAC deficiency, suggesting that LUBAC may modify additional key cellular substrates in promoting cell survival. GPx4 is an important selenoprotein involved in regulating cellular redox homeostasis in defense against lipid peroxidation-mediated cell death known as ferroptosis. Here we demonstrate that LUBAC deficiency sensitizes to ferroptosis by promoting GPx4 degradation and downstream lipid peroxidation. LUBAC binds and stabilizes GPx4 by modulating its linear ubiquitination both in normal condition and under oxidative stress. Our findings identify GPx4 as a key substrate of LUBAC and a previously unrecognized role of LUBAC-mediated linear ubiquitination in regulating cellular redox status and cell death.


Assuntos
Receptores Tipo I de Fatores de Necrose Tumoral , Ubiquitina , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , NF-kappa B/metabolismo , Ubiquitinação
7.
BMC Biol ; 22(1): 114, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38764013

RESUMO

BACKGROUND: Cotton is a major world cash crop and an important source of natural fiber, oil, and protein. Drought stress is becoming a restrictive factor affecting cotton production. To facilitate the development of drought-tolerant cotton varieties, it is necessary to study the molecular mechanism of drought stress response by exploring key drought-resistant genes and related regulatory factors. RESULTS: In this study, two cotton varieties, ZY007 (drought-sensitive) and ZY168 (drought-tolerant), showing obvious phenotypic differences under drought stress, were selected. A total of 25,898 drought-induced genes were identified, exhibiting significant enrichment in pathways related to plant stress responses. Under drought induction, At subgenome expression bias was observed at the whole-genome level, which may be due to stronger inhibition of Dt subgenome expression. A gene co-expression module that was significantly associated with drought resistance was identified. About 90% of topologically associating domain (TAD) boundaries were stable, and 6613 TAD variation events were identified between the two varieties under drought. We identified 92 genes in ZY007 and 98 in ZY168 related to chromatin 3D structural variation and induced by drought stress. These genes are closely linked to the cotton response to drought stress through canonical hormone-responsive pathways, modulation of kinase and phosphatase activities, facilitation of calcium ion transport, and other related molecular mechanisms. CONCLUSIONS: These results lay a foundation for elucidating the molecular mechanism of the cotton drought response and provide important regulatory locus and gene resources for the future molecular breeding of drought-resistant cotton varieties.


Assuntos
Cromatina , Secas , Regulação da Expressão Gênica de Plantas , Gossypium , Gossypium/genética , Gossypium/fisiologia , Cromatina/metabolismo , Estresse Fisiológico/genética , Genes de Plantas
8.
Br J Cancer ; 130(4): 597-612, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38184692

RESUMO

BACKGROUND: The expression of Egl-9 family hypoxia-inducible factor 3 (EGLN3) is notably decreased in various malignancies, including gastric cancer (GC). While the predominant focus has been on the hydroxylase activity of EGLN3 for its antitumour effects, recent findings have suggested nonenzymatic roles for EGLN3. METHODS: This study assessed the clinical significance of EGLN3 expression in GC and explored the connection between EGLN3 DNA promoter methylation and transcriptional silencing. To investigate the effect of EGLN3 on GC cells, a gain-of-function strategy was adopted. RNA sequencing was conducted to identify the key effector molecules and signalling pathways associated with EGLN3. RESULTS: EGLN3 expression was significantly reduced in GC tissues, correlating with poorer patient prognosis. EGLN3 hypermethylation disrupts transcriptional equilibrium, contributing to deeper tumour invasion and lymph node metastasis, thus exacerbating GC progression. Conversely, restoration of EGLN3 expression in GC cells substantially inhibited cell proliferation and metastasis. EGLN3 was also found to impede the malignant progression of GC cells by downregulating Jumonji C domain-containing protein 8-mediated activation of the NF-κB pathway, independent of its hydroxylase activity. CONCLUSIONS: EGLN3 has the potential to hinder the spread of GC cells through a nonenzymatic mechanism, thereby shedding light on the complex nature of GC progression.


Assuntos
NF-kappa B , Neoplasias Gástricas , Humanos , NF-kappa B/genética , NF-kappa B/metabolismo , Neoplasias Gástricas/patologia , Transdução de Sinais/genética , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Oxigenases de Função Mista/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo
9.
Small ; : e2400587, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38837673

RESUMO

Precise integration of diverse therapeutic approaches into nanomaterials is the key to the development of multimodal synergistic cancer therapy. In this work, tadpole-like carbon nanotubes with Fe nanoparticle encapsulated at the head and Zn single-atom anchored on the body (Fe@CNT-Zn) is precisely designed and facilely prepared via one-pot carbonization. In vitro studies revealed the integration of chemotherapy (CT), chemodynamic therapy (CDT), photothermal therapy (PTT), and photodynamic therapy (PDT) in Fe@CNT-Zn as well as the near-infrared light (NIR)-responsive cascade therapeutic efficacy. Furthermore, in vivo studies demonstrated the NIR-triggered cascade-amplifying synergistic cancer therapy in a B16 tumor-bearing mouse model. The results not only showcased the Fe@CNT-Zn as a potential tetramodal therapeutic platform, but also demonstrated a proof-of-concept on metal-organic framework-based "one stone for multiple birds" strategy for in situ functionalization of carbon materials.

10.
Opt Express ; 32(11): 19950-19962, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38859116

RESUMO

Semiconductor quantum dots (QDs) have recently caused a stir as a promising and powerful lighting material applied in real-time fluorescence detection, display, and imaging. Photonic nanostructures are well suited for enhancing photoluminescence (PL) due to their ability to tailor the electromagnetic field, which raises both radiative and nonradiative decay rate of QDs nearby. However, several proposed structures with a complicated manufacturing process or low PL enhancement hinder their application and commercialization. Here, we present two kinds of dual-resonance gratings to effectively improve PL enhancement and propose a facile fabrication method based on holographic lithography. A maximum of 220-fold PL enhancement from CdSe/CdS/ZnS QDs are realized on 1D Al-coated photoresist (PR) gratings, where dual resonance bands are excited to simultaneously overlap the absorption and emission bands of QDs, much larger than those of some reported structures. Giant PL enhancement realized by cost-effective method further suggests the potential of better developing the nanostructure to QD-based optical and optoelectronic devices.

11.
Reprod Biol Endocrinol ; 22(1): 5, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38169395

RESUMO

BACKGROUND: Neuroepithelial transforming gene 1 (NET1) is a RhoA subfamily guanine nucleotide exchange factor that governs a wide array of biological processes. However, its roles in meiotic oocyte remain unclear. We herein demonstrated that the NET1-HACE1-RAC1 pathway mediates meiotic defects in the progression of oocyte maturation. METHODS: NET1 was reduced using a specific small interfering RNA in mouse oocytes. Spindle assembly, chromosomal alignment, the actin cap, and chromosomal spreads were visualized by immunostaining and analyzed under confocal microscopy. We also applied mass spectroscopy, and western blot analysis for this investigation. RESULTS: Our results revealed that NET1 was localized to the nucleus at the GV stage, and that after GVBD, NET1 was localized to the cytoplasm and predominantly distributed around the chromosomes, commensurate with meiotic progression. NET1 resided in the cytoplasm and significantly accumulated on the spindle at the MI and MII stages. Mouse oocytes depleted of Net1 exhibited aberrant first polar body extrusion and asymmetric division defects. We also determined that Net1 depletion resulted in reduced RAC1 protein expression in mouse oocytes, and that NET1 protected RAC1 from degradation by HACE1, and it was essential for actin dynamics and meiotic spindle formation. Importantly, exogenous RAC1 expression in Net1-depleted oocytes significantly rescued these defects. CONCLUSIONS: Our results suggest that NET1 exhibits multiple roles in spindle stability and actin dynamics during mouse oocyte meiosis.


Assuntos
Actinas , Fuso Acromático , Animais , Camundongos , Actinas/metabolismo , Meiose , Oncogenes , Oócitos/metabolismo , Fuso Acromático/metabolismo
12.
Gastrointest Endosc ; 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38692516

RESUMO

BACKGROUND AND AIMS: Lymph node metastasis significantly affects the prognosis of early gastric cancer patients. Endoscopic ultrasonography (EUS) plays a crucial role in the preoperative assessment of early gastric cancer. This study evaluated the efficacy of EUS in identifying lymph node metastasis in early gastric cancer patients and developed a risk score model to aid in choosing the best treatment options. METHODS: We retrospectively analyzed the effectiveness of EUS for detecting lymph node metastasis in early gastric cancer patients. A risk score model for predicting lymph node metastasis preoperatively was created using independent risk factors identified through binary logistic regression analysis and subsequently validated. Receiver operating characteristic (ROC) curves were generated for both the development and validation cohorts. RESULTS: The overall accuracy of EUS in identifying lymph node metastasis was 85.3%, although its sensitivity (29.2%) and positive predictive value (38.7%) were relatively low. Patients were categorized based on preoperative risk factors for lymph node metastasis, including tumor size ≥20 mm, lymph nodes ≥10 mm, BMI ≥24 kg/m2, and lymph node metastasis on CT scans. A 7-point risk score model was developed to assess the likelihood of lymph node metastasis. The areas under the ROC curve (AUCs) for the development and validation sets were 0.842 and 0.837, respectively, with sensitivities of 64% and 79%, respectively. CONCLUSION: We developed a practical risk score model based on preoperative factors to help EUS predict lymph node metastasis in early gastric cancer patients, guiding the selection of optimal treatment approaches for these patients.

13.
Value Health ; 27(3): 330-339, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38135215

RESUMO

OBJECTIVES: This study aimed to develop the scoring functions for the recently developed value assessment framework (VAF) for China, which comprises 12 attributes. METHODS: We implemented a factorial survey among Chinese healthcare stakeholders from July to September 2022. A total of 240 hypothetical drug value profiles described by the VAF were grouped into 60 blocks and randomly assigned to respondents. Each respondent was assigned with 1 block, each presented in 3 disease scenarios of different levels of severity. For each profile, respondents were asked to assess the drug's value on a scale from 0 (lowest) to 10 (highest) and make 1 of the 3 insurance recommendations: cover, to be negotiated for coverage, or reject. Linear and logistic mixed-effects models were used to develop scoring functions for aggregating the value attributes. RESULTS: A total of 365 respondents participated in the survey. 3968 responses from 331 respondents were included in the analysis. Most of the included respondents were under 45 (n = 256, 77.3%), females (n = 208, 62.8%), living in urban areas (n = 296, 89.4%), and with a bachelor's degree or higher (n = 303, 91.5%). Health benefits and safety carried more weights than other attributes in the scoring functions across disease scenarios. The value and probability of entering negotiation or receiving insurance coverage for the attribute profiles for severe/critical disease were higher than for mild/moderate disease. CONCLUSIONS: The scoring functions of the VAF can be used to assess the value of a drug and its probability of entering negotiation or receiving insurance coverage in China.


Assuntos
Atenção à Saúde , Cobertura do Seguro , Feminino , Humanos , Inquéritos e Questionários , Probabilidade , China
14.
Artigo em Inglês | MEDLINE | ID: mdl-38547512

RESUMO

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. CVD and kidney disease are closely related, with kidney injury increasing CVD mortality. The pathogenesis of cardiovascular and renal diseases involves complex and diverse interactions between multiple extracellular and intracellular signaling molecules, among which transient receptor potential vanilloid 1 (TRPV1)/ transient receptor potential ankyrin 1(TRPA1) channels have received increasing attention. TRPV1 belongs to the vanilloid receptor subtype family of transient receptor potential (TRP) ion channels, and TRPA1 belongs to the TRP channel superfamily. TRPV1/TRPA1 are jointly involved in the management of cardiovascular and renal diseases, and play important roles in regulating vascular tension, promoting angiogenesis, anti-fibrosis, anti-inflammation, and anti-oxidation. The mechanism of TRPV1 / TRPA1 is mainly related to regulation of intracellular calcium influx and release of nitric oxide (NO) and calcitonin gene-related peptide (CGRP). Therefore, this study takes TRPV1 / TRPA1 channel as the research object, analyzes and summarizes the process and mechanism of TRPV1 / TRPA1 affecting cardiovascular and renal diseases, and lays a foundation for the treatment of cardio-renal diseases.

15.
J Nat Prod ; 87(4): 893-905, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38417166

RESUMO

The bridged polycyclic sesquiterpenoids derived from sativene, isosativene, and longifolene have unique structures, and many chemical synthesis approaches with at least 10 steps have been reported. However, their biosynthetic pathway remains undescribed. A minimal biosynthetic gene cluster (BGC), named bip, encoding a sesquiterpene cyclase (BipA) and a cytochrome P450 (BipB) is characterized to produce such complex sesquiterpenoids with multiple carbon skeletons based on enzymatic assays, heterologous expression, and precursor experiments. BipA is demonstrated as a versatile cyclase with (-)-sativene as the dominant product and (-)-isosativene and (-)-longifolene as minor ones. BipB is capable of hydroxylating different enantiomeric sesquiterpenes, such as (-)-longifolene and (+)-longifolene, at C-15 and C-14 in turn. The C-15- or both C-15- and C-14-hydroxylated products are then further oxidized by unclustered oxidases, resulting in a structurally diverse array of sesquiterpenoids. Bioinformatic analysis reveals the BipB homologues as a discrete clade of fungal sesquiterpene P450s. These findings elucidate the concise and divergent biosynthesis of such intricate bridged polycyclic sesquiterpenoids, offer valuable biocatalysts for biotransformation, and highlight the distinct biosynthetic strategy employed by nature compared to chemical synthesis.


Assuntos
Sistema Enzimático do Citocromo P-450 , Família Multigênica , Estrutura Molecular , Sistema Enzimático do Citocromo P-450/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sesquiterpenos/metabolismo , Sesquiterpenos/química , Vias Biossintéticas/genética , Sesquiterpenos Policíclicos/química , Sesquiterpenos Policíclicos/metabolismo , Estereoisomerismo
16.
Exp Cell Res ; 427(1): 113598, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37054772

RESUMO

Aberrantly activated mTOR signaling pathway is commonly found in malignancies including gastric cancer (GC). DEPTOR, as a naturally occurred inhibitor of mTOR, functions in the pro- or anti-tumor manner depending on distinct tumor contexts. However, the roles of DEPTOR in GC remain largely unknown. In this study, DEPTOR expression was identified to be significantly decreased in GC tissues compared with matched normal gastric tissues, and reduced DEPTOR level was indicative of poor prognosis in patients. Restored DEPTOR expression inhibited the propagation in AGS and NCI-N87 cells, whose DEPTOR levels are low, via deactivating mTOR signaling pathway. Likewise, cabergoline (CAB) attenuated the proliferation in AGS and NCI-N87 cells via partially rescuing DEPTOR protein level. Targeted metabolomics analysis showed that several key metabolites, such as l-serine, significantly changed in AGS cells with DEPTOR restoration. These results revealed the anti-proliferation function of DEPTOR in GC cells, suggesting that restored DEPTOR expression using CAB may be a potential therapeutic approach for patients with GC.


Assuntos
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/genética , Prognóstico , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Linhagem Celular Tumoral
17.
Acta Pharmacol Sin ; 45(2): 238-247, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37803138

RESUMO

The γ isoform of Class I PI3Ks (PI3Kγ) is primarily found in leukocytes and is essential for the function of myeloid cells, as it regulates the migration, differentiation, and activation of myeloid-lineage immune cells. Thus, PI3Kγ has been identified as a promising drug target for the treatment of inflammation, autoimmune disease, and immuno-oncology. Due to the high incidence of serious adverse events (AEs) associated with PI3K inhibitors, in the development of PI3Kγ inhibitors, isoform selectivity was deemed crucial. In this review, an overview of the development of PI3Kγ selective inhibitors in the past years is provided. The isoform selectivity of related drugs was achieved by different strategies, including inducing a specificity pocket by a propeller-shape structure, targeting steric differences in the solvent channel, and modulating the conformation of the Asp-Phe-Gly DFG motif, which have been demonstrated feasible by several successful cases. The insights in this manuscript may provide a potential direction for rational drug design and accelerate the discovery of PI3Kγ selective inhibitors.


Assuntos
Doenças Autoimunes , Fosfatidilinositol 3-Quinases , Humanos , Inibidores de Fosfoinositídeo-3 Quinase/química , Doenças Autoimunes/tratamento farmacológico , Isoformas de Proteínas , Inflamação/tratamento farmacológico
18.
Acta Pharmacol Sin ; 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38641746

RESUMO

Acute kidney injury (AKI) is defined as sudden loss of renal function characterized by increased serum creatinine levels and reduced urinary output with a duration of 7 days. Ferroptosis, an iron-dependent regulated necrotic pathway, has been implicated in the progression of AKI, while ferrostatin-1 (Fer-1), a selective inhibitor of ferroptosis, inhibited renal damage, oxidative stress and tubular cell death in AKI mouse models. However, the clinical translation of Fer-1 is limited due to its lack of efficacy and metabolic instability. In this study we designed and synthesized four Fer-1 analogs (Cpd-A1, Cpd-B1, Cpd-B2, Cpd-B3) with superior plasma stability, and evaluated their therapeutic potential in the treatment of AKI. Compared with Fer-1, all the four analogs displayed a higher distribution in mouse renal tissue in a pharmacokinetic assay and a more effective ferroptosis inhibition in erastin-treated mouse tubular epithelial cells (mTECs) with Cpd-A1 (N-methyl-substituted-tetrazole-Fer-1 analog) being the most efficacious one. In hypoxia/reoxygenation (H/R)- or LPS-treated mTECs, treatment with Cpd-A1 (0.25 µM) effectively attenuated cell damage, reduced inflammatory responses, and inhibited ferroptosis. In ischemia/reperfusion (I/R)- or cecal ligation and puncture (CLP)-induced AKI mouse models, pre-injection of Cpd-A1 (1.25, 2.5, 5 mg·kg-1·d-1, i.p.) dose-dependently improved kidney function, mitigated renal tubular injury, and abrogated inflammation. We conclude that Cpd-A1 may serve as a promising therapeutic agent for the treatment of AKI.

19.
Biotechnol Appl Biochem ; 71(1): 193-201, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37904286

RESUMO

In this study, an electrochemical biosensor was constructed for the detection of fibrin, specifically by a simple two-step approach, with a novel artificial enzyme (Tetrazyme) based on the DNA tetrahedral framework as signal probe. The multichannel screen-printed electrode with the activated surface cannot only remove some biological impurities, but also serve as a carrier to immobilize a large number of antigen proteins. The DNA tetrahedral nanostructure was employed to ensure the high sensitivity of the probe for biological analysis. The hemin was chimeric into the G-quadruplex to constitute the complex with peroxidase catalytic activity (hemin/G4-DNAzyme), subsequently, Tetrazyme was formed through combining of this complex and DNA tetrahedral nucleic acid framework. The artificial enzyme signal probe formed by the covalent combination of the homing peptide (Cys-Arg-Glu-Lys-Ala, CREKA), which is the aptamer of fibrin and the new artificial enzyme is fixed on the surface of the multichannel carbon electrode by CREKA-specific recognition, so as to realize the sensitive detection of fibrin. The feasibility of sensing platform was validated by cyclic voltammetry (CV) and amperometric i-t curve (IT) methods. Effects of Tetrazyme concentration, CREKA concentrations and hybridization time on the sensor were explored. Under the best optimal conditions of 0.6 µmol/L Tetrazyme, 80 µmol/L CREKA, and 2.5 h reaction time, the immunosensor had two linear detection ranges, 10-40 nmol/L, with linear regression equation Y = 0.01487X - 0.011 (R2 = 0.992), and 50-100 nmol/L, with linear regression equation Y = 0.00137X + 0.6405 (R2 = 0.998), the detection limit was 9.4 nmol/L, S/N ≥ 3. The biosensor could provide a new method with great potential for the detection of fibrin with good selectivity, stability, and reproducibility.


Assuntos
Técnicas Biossensoriais , Técnicas Biossensoriais/métodos , Hemina/química , Fibrina , Reprodutibilidade dos Testes , Limite de Detecção , Imunoensaio , DNA/química , Técnicas Eletroquímicas/métodos
20.
J Adolesc ; 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38804189

RESUMO

BACKGROUND: Academic cyberloafing refers to students' engagement in non-learning-related online activities during online courses, which can negatively affect their academic performance. Prior studies investigated cyberloafing primarily in the workplace, neglecting core behaviors and interactions among academic cyberloafing in educational contexts. AIMS: This study employed network analysis to capture academic cyberloafing as an interactive behavior network to explore the core behavioral patterns of academic cyberloafing and the interactions between these behaviors. MATERIALS & METHODS: A total of 3537 adolescents (Mage = 12.49; 53.7% boys and 46.3% girls) in China were included in this study. RESULTS: The findings indicated that "seeking gossip news" and "watching short videos" are central behaviors. Among boys, "browsing nonacademic web pages" and "watching short videos" are central behaviors; "seeking gossip news" is the most central behavior among girls. Furthermore, in early adolescence, central behaviors encompass "chatting privately" and "seeking gossip news"; in middle adolescence, central behaviors include "seeking gossip news" and "watching short videos." Additionally, the comparisons indicated that academic cyberloafing networks (between boys and girls; between early and middle adolescence) show a similar structure and global strength but differ in specific academic cyberloafing associations. CONCLUSION: As adolescents of different sexes and ages engage in academic cyberloafing differently, tailored education interventions can be implemented to address unregulated cyberloafing.

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