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1.
Cell Chem Biol ; 31(6): 1203-1218.e17, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38906111

RESUMO

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the biosynthesis of nicotinamide adenine dinucleotide (NAD+), making it a potential target for cancer therapy. Two challenges hinder its translation in the clinic: targeting the extracellular form of NAMPT (eNAMPT) remains insufficient, and side effects are observed in normal tissues. We previously utilized proteolysis-targeting chimera (PROTAC) to develop two compounds capable of simultaneously degrading iNAMPT and eNAMPT. Unfortunately, the pharmacokinetic properties were inadequate, and toxicities similar to those associated with traditional inhibitors arose. We have developed a next-generation PROTAC molecule 632005 to address these challenges, demonstrating exceptional target selectivity and bioavailability, improved in vivo exposure, extended half-life, and reduced clearance rate. When combined with nicotinic acid, 632005 exhibits safety and robust efficacy in treating NAPRT-deficient pan-cancers, including xenograft models with hematologic malignancy and prostate cancer and patient-derived xenograft (PDX) models with liver cancer. Our findings provide clinical references for patient selection and treatment strategies involving NAMPT-targeting PROTACs.


Assuntos
Antineoplásicos , Niacina , Nicotinamida Fosforribosiltransferase , Nicotinamida Fosforribosiltransferase/metabolismo , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Humanos , Animais , Niacina/química , Niacina/farmacologia , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Masculino , Proteólise/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Camundongos Nus , Citocinas/metabolismo , Linhagem Celular Tumoral , Feminino , Ensaios Antitumorais Modelo de Xenoenxerto , Estrutura Molecular , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia
2.
Cell Death Dis ; 15(5): 381, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816365

RESUMO

Osteosarcoma (OS) therapy presents numerous challenges, due largely to a low survival rate following metastasis onset. Nerve growth factor (NGF) has been implicated in the metastasis and progression of various cancers; however, the mechanism by which NGF promotes metastasis in osteosarcoma has yet to be elucidated. This study investigated the influence of NGF on the migration and metastasis of osteosarcoma patients (88 cases) as well as the underlying molecular mechanisms, based on RNA-sequencing and gene expression data from a public database (TARGET-OS). In osteosarcoma patients, the expression of NGF was significantly higher than that of other growth factors. This observation was confirmed in bone tissue arrays from 91 osteosarcoma patients, in which the expression levels of NGF and matrix metallopeptidase-2 (MMP-2) protein were significantly higher than in normal bone, and strongly correlated with tumor stage. In summary, NGF is positively correlated with MMP-2 in human osteosarcoma tissue and NGF promotes osteosarcoma cell metastasis by upregulating MMP-2 expression. In cellular experiments using human osteosarcoma cells (143B and MG63), NGF upregulated MMP-2 expression and promoted wound healing, cell migration, and cell invasion. Pre-treatment with MEK and ERK inhibitors or siRNA attenuated the effects of NGF on cell migration and invasion. Stimulation with NGF was shown to promote phosphorylation along the MEK/ERK signaling pathway and decrease the expression of microRNA-92a-1-5p (miR-92a-1-5p). In in vivo experiments involving an orthotopic mouse model, the overexpression of NGF enhanced the effects of NGF on lung metastasis. Note that larotrectinib (a tropomyosin kinase receptor) strongly inhibited the effect of NGF on lung metastasis. In conclusion, it appears that NGF promotes MMP-2-dependent cell migration by inhibiting the effects of miR-92a-1-5p via the MEK/ERK signaling cascade. Larotrectinib emerged as a potential drug for the treatment of NGF-mediated metastasis in osteosarcoma.


Assuntos
Neoplasias Ósseas , Movimento Celular , Metaloproteinase 2 da Matriz , Fator de Crescimento Neural , Osteossarcoma , Pirazóis , Pirimidinas , Humanos , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia , Osteossarcoma/metabolismo , Osteossarcoma/genética , Fator de Crescimento Neural/metabolismo , Animais , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Camundongos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Neoplasias Ósseas/genética , Camundongos Nus , Masculino , Metástase Neoplásica , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Camundongos Endogâmicos BALB C
3.
Acta Pharmacol Sin ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760543

RESUMO

Bevacizumab is a recombinant humanized monoclonal immunoglobulin (Ig) G1 antibody of VEGF, and inhibits angiogenesis and tumor growth in hepatocellular carcinoma (HCC). Ferroptosis, a new form of regulated cell death function independently of the apoptotic machinery, has been accepted as an attractive target for pharmacological intervention; the ferroptosis pathway can enhance cell immune activity of anti-PD1 immunotherapy in HCC. In this study we investigated whether and how bevacizumab regulated ferroptosis and immune activity in liver cancer. Firstly, we performed RNA-sequencing in bevacizumab-treated human liver cancer cell line HepG2 cells, and found that bevacizumab significantly altered the expression of a number of genes including VEGF, PI3K, HAT1, SLC7A11 and IL-9 in liver cancer, bevacizumab upregulated 37 ferroptosis-related drivers, and downregulated 17 ferroptosis-related suppressors in particular. We demonstrated that bevacizumab triggered ferroptosis in liver cancer cells by driving VEGF/PI3K/HAT1/SLC7A11 axis. Clinical data confirmed that the expression levels of VEGF were positively associated with those of PI3K, HAT1 and SLC7A11 in HCC tissues. Meanwhile, we found that bevacizumab enhanced immune cell activity in tumor immune-microenvironment. We identified that HAT1 up-regulated miR-143 targeting IL-9 mRNA 3'UTR in liver cancer cells; bevacizumab treatment resulted in the increase of IL-9 levels and its secretion via VEGF/PI3K/HAT1/miR-143/IL-9 axis, which led to the inhibition of tumor growth in vivo through increasing the release of IL-2 and Granzyme B from activated CD8+ T cells. We conclude that in addition to inhibiting angiogenesis, bevacizumab induces ferroptosis and enhances CD8+ T cell immune activity in liver cancer. This study provides new insight into the mechanisms by which bevacizumab synergistically modulates ferroptosis and CD8+ T cell immune activity in liver cancer.

4.
Acta Pharmacol Sin ; 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589688

RESUMO

Lymphocyte activation gene 3 (LAG3), an immune checkpoint molecule expressed on activated T cells, functions as a negative regulator of immune responses. Persistent antigen exposure in the tumor microenvironment results in sustained LAG3 expression on T cells, contributing to T cell dysfunction. Fibrinogen-like protein 1 (FGL1) has been identified as a major ligand of LAG3, and FGL1/LAG3 interaction forms a novel immune checkpoint pathway that results in tumor immune evasion. In addition, ubiquitin-specific peptidase 7 (USP7) plays a crucial role in cancer development. In this study we investigated the role of USP7 in modulation of FGL1-mediated liver cancer immune evasion. We showed that knockdown of USP7 or treatment with USP7 inhibitor P5091 suppressed liver cancer growth by promoting CD8+ T cell activity in Hepa1-6 xenograft mice and in HepG2 or Huh7 cells co-cultured with T cells, whereas USP7 overexpression produced the opposite effect. We found that USP7 upregulated FGL1 in HepG2 and Huh7 cells by deubiquitination of transcriptional factor PR domain zinc finger protein 1 (PRDM1), which transcriptionally activated FGL1, and attenuated the CD8+ T cell activity, leading to the liver cancer growth. Interestingly, USP7 could be transcriptionally stimulated by PRDM1 as well in a positive feedback loop. P5091, an inhibitor of USP7, was able to downregulate FGL1 expression, thus enhancing CD8+ T cell activity. In an immunocompetent liver cancer mouse model, the dual blockade of USP7 and LAG3 resulted in a superior antitumor activity compared with anti-LAG3 therapy alone. We conclude that USP7 diminishes CD8+ T cell activity by a USP7/PRDM1 positive feedback loop on FGL1 production in liver cancer; USP7 might be a promising target for liver cancer immunotherapy.

5.
Res Sq ; 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38659960

RESUMO

The World Health Organization has designated Pseudomonas aeruginosa as a critical pathogen for the development of new antimicrobials. Bacterial viruses, or bacteriophages, have been used in various clinical settings, commonly called phage therapy, to address this growing public health crisis. Here, we describe a high-resolution structural atlas of a therapeutic, contractile-tailed Pseudomonas phage, Pa193. We used bioinformatics, proteomics, and cryogenic electron microscopy single particle analysis to identify, annotate, and build atomic models for 21 distinct structural polypeptide chains forming the icosahedral capsid, neck, contractile tail, and baseplate. We identified a putative scaffolding protein stabilizing the interior of the capsid 5-fold vertex. We also visualized a large portion of Pa193 ~ 500 Å long tail fibers and resolved the interface between the baseplate and tail fibers. The work presented here provides a framework to support a better understanding of phages as biomedicines for phage therapy and inform engineering opportunities.

6.
Res Sq ; 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38463957

RESUMO

DEV is an obligatory lytic Pseudomonas phage of the N4-like genus, recently reclassified as Schitoviridae. The DEV genome encodes 91 ORFs, including a 3,398 amino acid virion-associated RNA polymerase. Here, we describe the complete architecture of DEV, determined using a combination of cryo-electron microscopy localized reconstruction, biochemical methods, and genetic knockouts. We built de novo structures of all capsid factors and tail components involved in host attachment. We demonstrate that DEV long tail fibers are essential for infection of Pseudomonas aeruginosa and dispensable for infecting mutants with a truncated lipopolysaccharide devoid of the O-antigen. We identified DEV ejection proteins and, unexpectedly, found that the giant DEV RNA polymerase, the hallmark of the Schitoviridae family, is an ejection protein. We propose that DEV ejection proteins form a genome ejection motor across the host cell envelope and that these structural principles are conserved in all Schitoviridae.

7.
Menopause ; 31(4): 282-287, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38412386

RESUMO

OBJECTIVE: Estrogen deficiency in postmenopausal women is associated with bone loss and a decline in muscle mass. However, the associations between lumbar muscle size and bone mineral density (BMD) in postmenopausal women with and without osteoporosis remain unclear. The aim of this study was to investigate the associations between lumbar muscle size and BMD in nonfractured postmenopausal women with osteoporosis and those with osteopenia. METHODS: A total of 89 postmenopausal women with osteopenia (n = 53) and osteoporosis (n = 36) were retrospectively enrolled in this study from 2014 to 2022. All participants underwent lumbar magnetic resonance imaging and dual-energy absorptiometry within a month. The lean lumbar muscle sizes at different lumbar levels were quantitatively evaluated on axial T1-weighted images. The associations between lumbar muscle size and BMD were analyzed using Pearson's correlation analysis. RESULTS: The osteoporosis group had significantly smaller lean psoas muscle sizes than the osteopenia group. Based on the correlation analysis, the erector spinae and multifidus muscle sizes were significantly associated with lumbar and femoral neck BMDs in the osteoporosis group. However, no significant association was found between lean psoas muscle size and BMDs in the osteopenia group. Thus, the associations between lumbar muscle decline and bone loss differed between postmenopausal women with osteoporosis and those with osteopenia. CONCLUSIONS: The study findings suggest differences in the associations between BMD and lumbar muscle size between postmenopausal women with osteoporosis and those with osteopenia.


Assuntos
Doenças Ósseas Metabólicas , Osteoporose Pós-Menopausa , Osteoporose , Feminino , Humanos , Densidade Óssea/fisiologia , Estudos Retrospectivos , Pós-Menopausa , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/complicações , Vértebras Lombares/diagnóstico por imagem , Osteoporose/complicações , Doenças Ósseas Metabólicas/diagnóstico por imagem , Músculos
8.
Sci Adv ; 10(2): eadi7606, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38198557

RESUMO

Nuclear import of the hepatitis B virus (HBV) nucleocapsid is essential for replication that occurs in the nucleus. The ~360-angstrom HBV capsid translocates to the nuclear pore complex (NPC) as an intact particle, hijacking human importins in a reaction stimulated by host kinases. This paper describes the mechanisms of HBV capsid recognition by importins. We found that importin α1 binds a nuclear localization signal (NLS) at the far end of the HBV coat protein Cp183 carboxyl-terminal domain (CTD). This NLS is exposed to the capsid surface through a pore at the icosahedral quasi-sixfold vertex. Phosphorylation at serine-155, serine-162, and serine-170 promotes CTD compaction but does not affect the affinity for importin α1. The binding of 30 importin α1/ß1 augments HBV capsid diameter to ~620 angstroms, close to the maximum size trafficable through the NPC. We propose that phosphorylation favors CTD externalization and prompts its compaction at the capsid surface, exposing the NLS to importins.


Assuntos
Vírus da Hepatite B , Nucleocapsídeo , Humanos , Transporte Ativo do Núcleo Celular , Carioferinas , Proteínas do Capsídeo , Fatores Imunológicos , Serina
9.
Small Methods ; 8(3): e2301249, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38012517

RESUMO

Proton exchange membrane fuel cells (PEMFCs) are gaining significant interest as an attractive substitute for traditional fuel cells, with higher energy density, lower environmental pollution, and better operation efficiency. However, the cathode reaction, i.e., the oxygen reduction reaction (ORR), is widely proved to be inefficient, and therefore an obstacle to the widespread development of PEMFCs. The requirement for affordable highly-efficient ORR catalysts is extremely urgent to be met, especially at fuel cell level. Unfortunately, most previous reports focus on the ORR performance at rotating disk electrodes (RDE) level instead of membrane electrode assembly (MEA) level, making it harder to evaluate ORR catalysts operating under real vehicle conditions. Obviously, it is extremely necessary to develop an in-depth understanding of the structure-activity relationship of highly-efficient ORR catalysts applied at MEA level. In this work, an overview of the latest advances in ORR catalysts is provided with an emphasis on their performance at MEA level, hoping to cover the novel and systemic insights for innovative and efficient ORR catalyst design and applications in PEMFCs.

10.
Hematology ; 29(1): 2293496, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38095349

RESUMO

OBJECTIVE: Extramedullary relapse (EMR) is rare in acute promyelocytic leukemia (APL) and, there is a lack of information on its management. Current practices for EMR in APL are always to adopt strategies from other subtypes of Acute lymphoblastic leukemia (ALL) and Acute myeloid leukemia (AML). Gilteritinib, a highly selective FLT3 inhibitor, has demonstrated a remarkable effect on EMR in FLT3-mutant AML. Therefore, it is worthwhile exploring if FLT3 mutation can be a therapeutic target and assessing the efficacy of Gilteritinib on FLT3-mutant EMR in APL. METHODS: We described three cases of FLT3-mutant EMR in APL, comprising two isolated EMR cases and one systemic relapse. The patients underwent treatment with Gilteritinib-based regimens based on FLT3 mutation. RESULTS: All three patients achieved complete regression of EMR, and no signs of tumor lysis syndrome during Gilteritinib-based therapy, only patient 1 showed mild granulocytopenia. They all maintained molecular complete remission (mCR) during the follow-up period. CONCLUSIONS: The Gilteritinib-based regimen shows a high and sustained therapeutic effect with minimal adverse effects, and provides a valuable experience for further evaluation in EMR APL patients.


Assuntos
Leucemia Mieloide Aguda , Leucemia Promielocítica Aguda , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/genética , Mutação , Leucemia Mieloide Aguda/genética , Recidiva , Tirosina Quinase 3 Semelhante a fms/genética
11.
Methods Mol Biol ; 2738: 215-228, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37966602

RESUMO

Cryogenic electron microscopy (cryo-EM) single-particle analysis has revolutionized the structural analysis of icosahedral viruses, including tailed bacteriophages. In recent years, localized (or focused) reconstruction has emerged as a powerful data analysis method to capture symmetry mismatches and resolve asymmetric features in icosahedral viruses. Here, we describe the methods used to reconstruct the 2.65-MDa tail apparatus of the Shigella phage Sf6, a representative member of the Podoviridae superfamily.


Assuntos
Shigella , Siphoviridae , Vírion , Projetos de Pesquisa , Imagem Individual de Molécula
12.
J Mol Biol ; 435(24): 168365, 2023 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-37952769

RESUMO

Bacteriophage P22 is a prototypical member of the Podoviridae superfamily. Since its discovery in 1952, P22 has become a paradigm for phage transduction and a model for icosahedral viral capsid assembly. Here, we describe the complete architecture of the P22 tail apparatus (gp1, gp4, gp10, gp9, and gp26) and the potential location and organization of P22 ejection proteins (gp7, gp20, and gp16), determined using cryo-EM localized reconstruction, genetic knockouts, and biochemical analysis. We found that the tail apparatus exists in two equivalent conformations, rotated by ∼6° relative to the capsid. Portal protomers make unique contacts with coat subunits in both conformations, explaining the 12:5 symmetry mismatch. The tail assembles around the hexameric tail hub (gp10), which folds into an interrupted ß-propeller characterized by an apical insertion domain. The tail hub connects proximally to the dodecameric portal protein and head-to-tail adapter (gp4), distally to the trimeric tail needle (gp26), and laterally to six trimeric tailspikes (gp9) that attach asymmetrically to gp10 insertion domain. Cryo-EM analysis of P22 mutants lacking the ejection proteins gp7 or gp20 and biochemical analysis of purified recombinant proteins suggest that gp7 and gp20 form a molecular complex associated with the tail apparatus via the portal protein barrel. We identified a putative signal transduction pathway from the tailspike to the tail needle, mediated by three flexible loops in the tail hub, that explains how lipopolysaccharide (LPS) is sufficient to trigger the ejection of the P22 DNA in vitro.


Assuntos
Bacteriófago P22 , Salmonella typhimurium , Bacteriófago P22/genética , Bacteriófago P22/química , Bacteriófago P22/metabolismo , Proteínas do Capsídeo/química , Salmonella typhimurium/virologia , Proteínas da Cauda Viral/genética
13.
Behav Sci (Basel) ; 13(11)2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37998650

RESUMO

In this study, we examined the relationships between the use of online dating applications (apps), online victimization, and psychosocial distress among adolescents. This study was conducted in 2020. A sample of 2595 seventh-grade students from 30 Taiwanese middle schools was surveyed. We conducted a self-administered survey. Overall, 15% of the adolescents reported using online dating apps in the past year, while 78% reported having seen dating app advertisements on the internet in the past year. Multivariate analysis results indicated that adolescents' exposure to the marketing of dating apps and poor academic performance were both associated with the use of online dating apps. Adolescents who used dating apps were more likely to experience online privacy victimization, cyberbullying victimization, and online sexual harassment. The use of dating apps by adolescents, online privacy victimization, cyberbullying victimization, and online sexual harassment were associated with higher levels of depression, anxiety, and stress. In conclusion, adolescent use of dating apps is related to online victimization and psychological distress.

14.
Cell Rep ; 42(10): 113246, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37831605

RESUMO

Metastasis is the leading cause of high ovarian-cancer-related mortality worldwide. Three major processes constitute the whole metastatic cascade: invasion, intravasation, and extravasation. Tumor cells often reprogram their metabolism to gain advantages in proliferation and survival. However, whether and how those metabolic alterations contribute to the invasiveness of tumor cells has yet to be fully understood. Here we performed a genome-wide CRISPR-Cas9 screening to identify genes participating in tumor cell dissemination and revealed that PTGES3 acts as an invasion suppressor in ovarian cancer. Mechanistically, PTGES3 binds to phosphofructokinase, liver type (PFKL) and generates a local source of prostaglandin E2 (PGE2) to allosterically inhibit the enzymatic activity of PFKL. Repressed PFKL leads to downgraded glycolysis and the subsequent TCA cycle for glucose metabolism. However, ovarian cancer suppresses the expression of PTGES3 and disrupts the PTGES3-PGE2-PFKL inhibitory axis, leading to hyperactivation of glucose oxidation, eventually facilitating ovarian cancer cell motility and invasiveness.


Assuntos
Dinoprostona , Neoplasias Ovarianas , Humanos , Feminino , Fosfofrutoquinases , Fosfofrutoquinase-1/genética , Fígado/metabolismo , Glucose/metabolismo , Neoplasias Ovarianas/patologia , Proliferação de Células , Linhagem Celular Tumoral , Invasividade Neoplásica
15.
Int Immunopharmacol ; 124(Pt B): 110909, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37722260

RESUMO

Rheumatoid arthritis (RA) is the most common autoimmune disease, affecting the joints of the hands and feet. Several chemokines and their receptors are crucial in RA pathogenesis through immune cell recruitment. C-X-C Motif Chemokine Ligand 1 (CXCL1), a chemokine for the recruitment of various immune cells, can be upregulated in patients with RA. However, the discussion on the role of CXCL1 in RA pathogenesis is insufficient. Here, we found that CXCL1 promoted cyclooxygenase-2 (COX-II) expression in a dose- and time-dependent manner in rheumatoid arthritis synovial fibroblasts (RASFs). CXCL1 overexpression in RASFs led to a significant increase in COX-II expression, while the transfection of RASFs with the shRNA plasmid resulted in a noticeable decrease in COX-II expression. Next, we delineated the molecular mechanism underlying CXCL1-promoted COX-II expression and noted that CXC chemokine receptor 2 (CXCR2), phospholipase C (PLC), and protein kinase C (PKC) signal transduction were responsible for COX-II expression after CXCL1 incubation for RASFs. Finally, we confirmed the transcriptional activation of nuclear factor κB (NF-κB) in RASFs after incubation with CXCL1. In conclusion, the current study provided a novel insight into the role of CXCL1 in RA pathogenesis.


Assuntos
Artrite Reumatoide , NF-kappa B , Humanos , NF-kappa B/metabolismo , Receptores de Interleucina-8B/metabolismo , Membrana Sinovial/patologia , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Fosfolipases Tipo C/metabolismo , Transdução de Sinais , Quimiocinas/metabolismo , Fibroblastos/metabolismo , Células Cultivadas , Quimiocina CXCL1/metabolismo
16.
Environ Sci Technol ; 57(40): 15232-15242, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37603422

RESUMO

Breakpoint chlorination is prevalent in drinking water and potable reuse water treatment. Breakpoint chlorination enhances the formation of N-nitrosamines through reactions that form nitrosating agents. The most recent study suggests that nitroxyl (HNO) can react with free chlorine (HOCl) to form the nitrosyl chloride (ClNO) nitrosating agent but has not experimentally verified its importance in breakpoint chlorination. This study first assessed the formation of N-nitrosamines from model N-chloro-alkylamine precursors when they were added to a mixture of HOCl and HNO-derived nitrosating agents generated by chlorinating hydroxyurea. Results demonstrated negligible N-nitrosamine formation. Instead, we observed that the interaction of NCl3 with NHCl2 (total Cl2/total N molar ratio = 2.4-3:1) produced an intermediate capable of nitrosating N-chloro-alkylamines to N-nitrosamines at yields 8-fold higher to those observed in NHCl2 treatment alone, within a very short timescale (<3 min). We examined the stoichiometry of the reaction of NCl3 with NHCl2 using a UV-spectrum-based approach. Nitrosyl chloride was proposed as the key intermediate, likely formed alongside the reformation of NHCl2. Further isotopic experiments, byproduct measurements, and kinetic modeling supported the hypotheses. Modeling indicated that the reaction of NCl3 with NHCl2 explained ∼75% of NDMA formation during breakpoint chlorination. Because NCl3 is mainly derived from the reaction of HOCl with NHCl2, controlling NHCl2 (e.g., with additional treatment) is critical for minimizing nitrosamine formation in waters where breakpoint chlorination occurs.

17.
Acta Pharmacol Sin ; 44(12): 2525-2536, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37474643

RESUMO

Heat shock protein family A member 8 (HSPA8) participates in the folding or degradation of misfolded proteins under stress and plays critical roles in cancer. In this study, we investigated the function of HSPA8 in the development of liver cancer. By analyzing the TCGA transcriptome dataset, we found that HSPA8 was upregulated in 134 clinical liver cancer tissue samples, and positively correlated with poor prognosis. IHC staining showed the nuclear and cytoplasmic localization of HSPA8 in liver cancer cells. Knockdown of HSPA8 resulted in a decrease in the proliferation of HepG2 and Huh-7 cells. ChIP-seq and RNA-seq analysis revealed that HSPA8 bound to the promoter of pleckstrin homology-like domain family A member 2 (PHLDA2) and regulated its expression. The transcription factor ETV4 in HepG2 cells activated PHLDA2 transcription. HSPA8 and ETV4 could interact with each other in the cells and colocalize in the nucleus. From a functional perspective, we demonstrated that HSPA8 upregulated PHDLA2 through the coactivating transcription factor ETV4 to enhance the growth of liver cancer in vitro and in vivo. From a therapeutic perspective, we identified both HSPA8 and PHDLA2 as novel targets in the treatment of HCC. In conclusion, this study demonstrates that HSPA8 serves as a coactivator of ETV4 and upregulates PHLDA2, leading to the growth of HCC, and is a potential therapeutic target in HCC treatment.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/genética , Fatores de Transcrição/genética , Carcinoma Hepatocelular/genética , Proteínas de Choque Térmico , Regulação da Expressão Gênica , Proteínas Proto-Oncogênicas c-ets/genética
18.
Nat Commun ; 14(1): 4052, 2023 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-37422479

RESUMO

E217 is a Pseudomonas phage used in an experimental cocktail to eradicate cystic fibrosis-associated Pseudomonas aeruginosa. Here, we describe the structure of the whole E217 virion before and after DNA ejection at 3.1 Å and 4.5 Å resolution, respectively, determined using cryogenic electron microscopy (cryo-EM). We identify and build de novo structures for 19 unique E217 gene products, resolve the tail genome-ejection machine in both extended and contracted states, and decipher the complete architecture of the baseplate formed by 66 polypeptide chains. We also determine that E217 recognizes the host O-antigen as a receptor, and we resolve the N-terminal portion of the O-antigen-binding tail fiber. We propose that E217 design principles presented in this paper are conserved across PB1-like Myoviridae phages of the Pbunavirus genus that encode a ~1.4 MDa baseplate, dramatically smaller than the coliphage T4.


Assuntos
Fagos de Pseudomonas , Fagos de Pseudomonas/genética , Microscopia Crioeletrônica , Antígenos O , Microscopia Eletrônica , Myoviridae , Bacteriófago T4/química
19.
Cells ; 12(13)2023 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-37443757

RESUMO

We assessed interactions between the astrocytic volume-regulated anion channel (VRAC) and aquaporin 4 (AQP4) in the supraoptic nucleus (SON). Acute SON slices and cultures of hypothalamic astrocytes prepared from rats received hyposmotic challenge (HOC) with/without VRAC or AQP4 blockers. In acute slices, HOC caused an early decrease with a late rebound in the neuronal firing rate of vasopressin neurons, which required activity of astrocytic AQP4 and VRAC. HOC also caused a persistent decrease in the excitatory postsynaptic current frequency, supported by VRAC and AQP4 activity in early HOC; late HOC required only VRAC activity. These events were associated with the dynamics of glial fibrillary acidic protein (GFAP) filaments, the late retraction of which was mediated by VRAC activity; this activity also mediated an HOC-evoked early increase in AQP4 expression and late subside in GFAP-AQP4 colocalization. AQP4 activity supported an early HOC-evoked increase in VRAC levels and its colocalization with GFAP. In cultured astrocytes, late HOC augmented VRAC currents, the activation of which depended on AQP4 pre-HOC/HOC activity. HOC caused an early increase in VRAC expression followed by a late rebound, requiring AQP4 and VRAC, or only AQP4 activity, respectively. Astrocytic swelling in early HOC depended on AQP4 activity, and so did the early extension of GFAP filaments. VRAC and AQP4 activity supported late regulatory volume decrease, the retraction of GFAP filaments, and subside in GFAP-VRAC colocalization. Taken together, astrocytic morphological plasticity relies on the coordinated activities of VRAC and AQP4, which are mutually regulated in the astrocytic mediation of HOC-evoked modulation of vasopressin neuronal activity.


Assuntos
Aquaporina 4 , Núcleo Supraóptico , Ratos , Animais , Aquaporina 4/metabolismo , Núcleo Supraóptico/metabolismo , Astrócitos/metabolismo , Vasopressinas/farmacologia , Vasopressinas/metabolismo , Ânions/metabolismo , Neurônios/metabolismo
20.
J Plast Reconstr Aesthet Surg ; 85: 26-33, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37454547

RESUMO

BACKGROUND: Although replantation of amputated facial segments remains challenging in reconstructive surgery, it offers excellent aesthetic and functional outcomes. METHODS: From May 2004 to October 2019, 12 patients underwent replantation of amputated facial tissues by supermicrosurgery. The case details, such as the rationale for replantation, the operation method, and postoperative therapy, are described. Four cases are discussed to demonstrate the replantation of different facial parts. RESULTS: Facial tissue replantation was successful in all 12 patients without secondary surgery. The cases included the nose (1 patient), ears (8 patients), lips (2 patients), and one of the soft tissue segments surrounding the lower jaw. Venous congestion occurred in three patients who received a solitary arterial repair and were treated with bloodletting. All patients expressed satisfaction with the cosmetic and functional results at the final follow-up. CONCLUSIONS: Supermicrosurgical facial tissue replantation is a promising and effective procedure for providing patients with the best aesthetic and functional outcomes.


Assuntos
Amputação Traumática , Procedimentos de Cirurgia Plástica , Humanos , Amputação Traumática/cirurgia , Microcirurgia/métodos , Reimplante/métodos , Nariz/cirurgia
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