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1.
Mol Cell ; 83(22): 4000-4016.e6, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37935198

RESUMO

While 19S proteasome regulatory particle (RP) inhibition is a promising new avenue for treating bortezomib-resistant myeloma, the anti-tumor impact of inhibiting 19S RP component PSMD14 could not be explained by a selective inhibition of proteasomal activity. Here, we report that PSMD14 interacts with NSD2 on chromatin, independent of 19S RP. Functionally, PSMD14 acts as a histone H2AK119 deubiquitinase, facilitating NSD2-directed H3K36 dimethylation. Integrative genomic and epigenomic analyses revealed the functional coordination of PSMD14 and NSD2 in transcriptional activation of target genes (e.g., RELA) linked to myelomagenesis. Reciprocally, RELA transactivates PSMD14, forming a PSMD14/NSD2-RELA positive feedback loop. Remarkably, PSMD14 inhibitors enhance bortezomib sensitivity and fosters anti-myeloma synergy. PSMD14 expression is elevated in myeloma and inversely correlated with overall survival. Our study uncovers an unappreciated function of PSMD14 as an epigenetic regulator and a myeloma driver, supporting the pursuit of PSMD14 as a therapeutic target to overcome the treatment limitation of myeloma.


Assuntos
Histonas , Mieloma Múltiplo , Humanos , Histonas/genética , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Bortezomib/farmacologia , Bortezomib/metabolismo , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Linhagem Celular Tumoral , Enzimas Desubiquitinantes/metabolismo , Inibidores de Proteassoma/farmacologia , Transativadores/metabolismo
2.
Mol Cell ; 82(2): 420-434.e6, 2022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-34951963

RESUMO

Exon back-splicing-generated circular RNAs, as a group, can suppress double-stranded RNA (dsRNA)-activated protein kinase R (PKR) in cells. We have sought to synthesize immunogenicity-free, short dsRNA-containing RNA circles as PKR inhibitors. Here, we report that RNA circles synthesized by permuted self-splicing thymidylate synthase (td) introns from T4 bacteriophage or by Anabaena pre-tRNA group I intron could induce an immune response. Autocatalytic splicing introduces ∼74 nt td or ∼186 nt Anabaena extraneous fragments that can distort the folding status of original circular RNAs or form structures themselves to provoke innate immune responses. In contrast, synthesized RNA circles produced by T4 RNA ligase without extraneous fragments exhibit minimized immunogenicity. Importantly, directly ligated circular RNAs that form short dsRNA regions efficiently suppress PKR activation 103- to 106-fold higher than reported chemical compounds C16 and 2-AP, highlighting the future use of circular RNAs as potent inhibitors for diseases related to PKR overreaction.


Assuntos
Inibidores de Proteínas Quinases/farmacologia , RNA Circular/farmacologia , eIF-2 Quinase/antagonistas & inibidores , Células A549 , Bacteriófago T4/enzimologia , Bacteriófago T4/genética , Células HEK293 , Células HeLa , Humanos , Imunidade Inata/efeitos dos fármacos , Íntrons , Conformação de Ácido Nucleico , Inibidores de Proteínas Quinases/imunologia , RNA Ligase (ATP)/genética , RNA Ligase (ATP)/metabolismo , Precursores de RNA/genética , Precursores de RNA/metabolismo , RNA Circular/genética , RNA Circular/imunologia , Timidilato Sintase/genética , Timidilato Sintase/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , eIF-2 Quinase/metabolismo
3.
Mol Cell ; 81(11): 2361-2373.e9, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-33838104

RESUMO

Toxin-antitoxin (TA) systems are widespread in bacteria, but their activation mechanisms and bona fide targets remain largely unknown. Here, we characterize a type III TA system, toxIN, that protects E. coli against multiple bacteriophages, including T4. Using RNA sequencing, we find that the endoribonuclease ToxN is activated following T4 infection and blocks phage development primarily by cleaving viral mRNAs and inhibiting their translation. ToxN activation arises from T4-induced shutoff of host transcription, specifically of toxIN, leading to loss of the intrinsically unstable toxI antitoxin. Transcriptional shutoff is necessary and sufficient for ToxN activation. Notably, toxIN does not strongly protect against another phage, T7, which incompletely blocks host transcription. Thus, our results reveal a critical trade-off in blocking host transcription: it helps phage commandeer host resources but can activate potent defense systems. More generally, our results now reveal the native targets of an RNase toxin and activation mechanism of a phage-defensive TA system.


Assuntos
Bacteriófago T4/genética , Bacteriófago T7/genética , Endorribonucleases/genética , Proteínas de Escherichia coli/genética , Escherichia coli/virologia , Sistemas Toxina-Antitoxina/genética , Antibiose/genética , Bacteriófago T4/crescimento & desenvolvimento , Bacteriófago T4/metabolismo , Bacteriófago T7/crescimento & desenvolvimento , Bacteriófago T7/metabolismo , Endorribonucleases/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Transcrição Gênica
4.
Physiol Rev ; 101(1): 319-352, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32584192

RESUMO

The extracellular domain of plasma membrane integrin αvß3 contains a cell surface receptor for thyroid hormone analogues. The receptor is largely expressed and activated in tumor cells and rapidly dividing endothelial cells. The principal ligand for this receptor is l-thyroxine (T4), usually regarded only as a prohormone for 3,5,3'-triiodo-l-thyronine (T3), the hormone analogue that expresses thyroid hormone in the cell nucleus via nuclear receptors that are unrelated structurally to integrin αvß3. At the integrin receptor for thyroid hormone, T4 regulates cancer and endothelial cell division, tumor cell defense pathways (such as anti-apoptosis), and angiogenesis and supports metastasis, radioresistance, and chemoresistance. The molecular mechanisms involve signal transduction via mitogen-activated protein kinase and phosphatidylinositol 3-kinase, differential expression of multiple genes related to the listed cell processes, and regulation of activities of other cell surface proteins, such as vascular growth factor receptors. Tetraiodothyroacetic acid (tetrac) is derived from T4 and competes with binding of T4 to the integrin. In the absence of T4, tetrac and chemically modified tetrac also have anticancer effects that culminate in altered gene transcription. Tumor xenografts are arrested by unmodified and chemically modified tetrac. The receptor requires further characterization in terms of contributions to nonmalignant cells, such as platelets and phagocytes. The integrin αvß3 receptor for thyroid hormone offers a large panel of cellular actions that are relevant to cancer biology and that may be regulated by tetrac derivatives.


Assuntos
Integrinas/fisiologia , Hormônios Tireóideos/fisiologia , Animais , Humanos , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Receptores dos Hormônios Tireóideos/fisiologia , Transdução de Sinais , Tiroxina/fisiologia , Tri-Iodotironina
5.
EMBO J ; 43(15): 3287-3306, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38886579

RESUMO

Conjugative type IV secretion systems (T4SS) mediate bacterial conjugation, a process that enables the unidirectional exchange of genetic materials between a donor and a recipient bacterial cell. Bacterial conjugation is the primary means by which antibiotic resistance genes spread among bacterial populations (Barlow 2009; Virolle et al, 2020). Conjugative T4SSs form pili: long extracellular filaments that connect with recipient cells. Previously, we solved the cryo-electron microscopy (cryo-EM) structure of a conjugative T4SS. In this article, based on additional data, we present a more complete T4SS cryo-EM structure than that published earlier. Novel structural features include details of the mismatch symmetry within the OMCC, the presence of a fourth VirB8 subunit in the asymmetric unit of both the arches and the inner membrane complex (IMC), and a hydrophobic VirB5 tip in the distal end of the stalk. Additionally, we provide previously undescribed structural insights into the protein VirB10 and identify a novel regulation mechanism of T4SS-mediated pilus biogenesis by this protein, that we believe is a key checkpoint for this process.


Assuntos
Microscopia Crioeletrônica , Fímbrias Bacterianas , Sistemas de Secreção Tipo IV , Fímbrias Bacterianas/metabolismo , Fímbrias Bacterianas/ultraestrutura , Fímbrias Bacterianas/genética , Sistemas de Secreção Tipo IV/metabolismo , Sistemas de Secreção Tipo IV/genética , Sistemas de Secreção Tipo IV/química , Modelos Moleculares , Conjugação Genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/química , Escherichia coli/metabolismo , Escherichia coli/genética , Conformação Proteica
6.
Proc Natl Acad Sci U S A ; 121(41): e2401897121, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39352935

RESUMO

The Legionella pneumophila Dot/Icm type IVB secretion system (T4BSS) is a large, multisubunit complex that exports a vast array of substrates into eukaryotic host cells. DotO, a distant homolog of the T4ASS ATPase VirB4, associates with the bacterial inner membrane despite lacking hydrophobic transmembrane domains. Employing a genetic approach, we found DotO's membrane association is mediated by three inner-membrane Dot/Icm components, IcmT, and a combined DotJ-DotI complex (referred to as DotJI). Although deletion of icmT or dotJI individually does not affect DotO's membrane association, the simultaneous inactivation of all three genes results in increased amounts of soluble DotO. Nevertheless, deleting each receptor separately profoundly affects positioning of DotO, disrupting its link with the Dot/Icm complex at the bacterial poles, rendering the receptors nonredundant. Furthermore, a collection of dotO point mutants that we isolated established that DotO's N-terminal domain interacts with the membrane receptors and is involved in dimerization, whereas DotO's C-terminal ATPase domain primarily contributes to the protein's formation of oligomers. Modeling data revealed the complex interaction between DotO and its receptors is responsible for formation of DotO's unique "hexamer of dimers" configuration, which is a defining characteristic of VirB4 family members.


Assuntos
Adenosina Trifosfatases , Proteínas de Bactérias , Legionella pneumophila , Legionella pneumophila/metabolismo , Legionella pneumophila/genética , Legionella pneumophila/enzimologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/genética , Membrana Celular/metabolismo , Sistemas de Secreção Tipo IV/metabolismo , Sistemas de Secreção Tipo IV/genética
7.
Proc Natl Acad Sci U S A ; 121(33): e2405209121, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39106308

RESUMO

The obligatory intracellular bacterium Anaplasma phagocytophilum causes human granulocytic anaplasmosis, an emerging zoonosis. Anaplasma has limited biosynthetic and metabolic capacities, yet it effectively replicates inside of inclusions/vacuoles of eukaryotic host cells. Here, we describe a unique Type IV secretion system (T4SS) effector, ER-Golgi exit site protein of Anaplasma (EgeA). In cells infected by Anaplasma, secreted native EgeA, EgeA-GFP, and the C-terminal half of EgeA (EgeA-C)-GFP localized to Anaplasma-containing inclusions. In uninfected cells, EgeA-C-GFP localized to cis-Golgi, whereas the N-terminal half of EgeA-GFP localized to the ER. Pull-down assays identified EgeA-GFP binding to a transmembrane protein in the ER, Transport and Golgi organization protein 1 (TANGO1). By yeast two-hybrid analysis, EgeA-C directly bound Sec1 family domain-containing protein 1 (SCFD1), a host protein of the cis-Golgi network that binds TANGO1 at ER-Golgi exit sites (ERES). Both TANGO1 and SCFD1 localized to the Anaplasma inclusion surface. Furthermore, knockdown of Anaplasma EgeA or either host TANGO1 or SCFD1 significantly reduced Anaplasma infection. TANGO1 and SCFD1 prevent ER congestion and stress by facilitating transport of bulky or unfolded proteins at ERES. A bulky cargo collagen and the ER-resident chaperon BiP were transported into Anaplasma inclusions, and several ER stress marker genes were not up-regulated in Anaplasma-infected cells. Furthermore, EgeA transfection reduced collagen overexpression-induced BiP upregulation. These results suggest that by binding to the two ERES proteins, EgeA redirects the cargo-adapted ERES to pathogen-occupied inclusions and reduces ERES congestion, which facilitates Anaplasma nutrient acquisition and reduces ER stress for Anaplasma survival and proliferation.


Assuntos
Anaplasma phagocytophilum , Proteínas de Bactérias , Retículo Endoplasmático , Complexo de Golgi , Anaplasma phagocytophilum/metabolismo , Anaplasma phagocytophilum/patogenicidade , Retículo Endoplasmático/metabolismo , Humanos , Complexo de Golgi/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Corpos de Inclusão/metabolismo , Corpos de Inclusão/microbiologia , Animais , Sistemas de Secreção Tipo IV/metabolismo , Sistemas de Secreção Tipo IV/genética , Interações Hospedeiro-Patógeno
8.
Mol Microbiol ; 121(4): 636-645, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37975530

RESUMO

Bacterial secretion systems, such as the type 3, 4, and 6 are multiprotein nanomachines expressed at the surface of pathogens with Gram-negative like envelopes. They are known to be crucial for virulence and to translocate bacteria-encoded effector proteins into host cells to manipulate cellular functions. This facilitates either pathogen attachment or invasion of the targeted cell. Effector proteins also promote evasion of host immune recognition. Imaging by cryo-electron microscopy in combination with structure determination has become a powerful approach to understand how these nanomachines work. Still, questions on their assembly, the precise secretion mechanisms, and their direct involvement in pathogenicity remain unsolved. Here, we present an overview of the recent developments in in situ cryo-electron microscopy. We discuss its potential for the investigation of the role of bacterial secretion systems during the host-bacterial crosstalk at the molecular level. These in situ studies open new perspectives for our understanding of secretion system structure and function.


Assuntos
Sistemas de Secreção Bacterianos , Tomografia com Microscopia Eletrônica , Tomografia com Microscopia Eletrônica/métodos , Microscopia Crioeletrônica , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Sistemas de Secreção Tipo III/metabolismo
9.
Proc Natl Acad Sci U S A ; 119(40): e2203272119, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36161892

RESUMO

Many icosahedral viruses assemble proteinaceous precursors called proheads or procapsids. Proheads are metastable structures that undergo a profound structural transition known as expansion that transforms an immature unexpanded head into a mature genome-packaging head. Bacteriophage T4 is a model virus, well studied genetically and biochemically, but its structure determination has been challenging because of its large size and unusually prolate-shaped, ∼1,200-Å-long and ∼860-Å-wide capsid. Here, we report the cryogenic electron microscopy (cryo-EM) structures of T4 capsid in both of its major conformational states: unexpanded at a resolution of 5.1 Å and expanded at a resolution of 3.4 Å. These are among the largest structures deposited in Protein Data Bank to date and provide insights into virus assembly, head length determination, and shell expansion. First, the structures illustrate major domain movements and ∼70% additional gain in inner capsid volume, an essential transformation to contain the entire viral genome. Second, intricate intracapsomer interactions involving a unique insertion domain dramatically change, allowing the capsid subunits to rotate and twist while the capsomers remain fastened at quasi-threefold axes. Third, high-affinity binding sites emerge for a capsid decoration protein that clamps adjacent capsomers, imparting extraordinary structural stability. Fourth, subtle conformational changes at capsomers' periphery modulate intercapsomer angles between capsomer planes that control capsid length. Finally, conformational changes were observed at the symmetry-mismatched portal vertex, which might be involved in triggering head expansion. These analyses illustrate how small changes in local capsid subunit interactions lead to profound shifts in viral capsid morphology, stability, and volume.


Assuntos
Bacteriófago T4 , Capsídeo , Vírion , Bacteriófago T4/química , Bacteriófago T4/fisiologia , Capsídeo/química , Proteínas do Capsídeo/química , Microscopia Crioeletrônica , Domínios Proteicos , Vírion/química , Montagem de Vírus
10.
J Virol ; 97(6): e0059923, 2023 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-37306585

RESUMO

Many phages, such as T4, protect their genomes against the nucleases of bacterial restriction-modification (R-M) and CRISPR-Cas systems through covalent modification of their genomes. Recent studies have revealed many novel nuclease-containing antiphage systems, raising the question of the role of phage genome modifications in countering these systems. Here, by focusing on phage T4 and its host Escherichia coli, we depicted the landscape of the new nuclease-containing systems in E. coli and demonstrated the roles of T4 genome modifications in countering these systems. Our analysis identified at least 17 nuclease-containing defense systems in E. coli, with type III Druantia being the most abundant system, followed by Zorya, Septu, Gabija, AVAST type 4, and qatABCD. Of these, 8 nuclease-containing systems were found to be active against phage T4 infection. During T4 replication in E. coli, 5-hydroxymethyl dCTP is incorporated into the newly synthesized DNA instead of dCTP. The 5-hydroxymethylcytosines (hmCs) are further modified by glycosylation to form glucosyl-5-hydroxymethylcytosine (ghmC). Our data showed that the ghmC modification of the T4 genome abolished the defense activities of Gabija, Shedu, Restriction-like, type III Druantia, and qatABCD systems. The anti-phage T4 activities of the last two systems can also be counteracted by hmC modification. Interestingly, the Restriction-like system specifically restricts phage T4 containing an hmC-modified genome. The ghmC modification cannot abolish the anti-phage T4 activities of Septu, SspBCDE, and mzaABCDE, although it reduces their efficiency. Our study reveals the multidimensional defense strategies of E. coli nuclease-containing systems and the complex roles of T4 genomic modification in countering these defense systems. IMPORTANCE Cleavage of foreign DNA is a well-known mechanism used by bacteria to protect themselves from phage infections. Two well-known bacterial defense systems, R-M and CRISPR-Cas, both contain nucleases that cleave the phage genomes through specific mechanisms. However, phages have evolved different strategies to modify their genomes to prevent cleavage. Recent studies have revealed many novel nuclease-containing antiphage systems from various bacteria and archaea. However, no studies have systematically investigated the nuclease-containing antiphage systems of a specific bacterial species. In addition, the role of phage genome modifications in countering these systems remains unknown. Here, by focusing on phage T4 and its host Escherichia coli, we depicted the landscape of the new nuclease-containing systems in E. coli using all 2,289 genomes available in NCBI. Our studies reveal the multidimensional defense strategies of E. coli nuclease-containing systems and the complex roles of genomic modification of phage T4 in countering these defense systems.


Assuntos
Bacteriófago T4 , Enzimas de Restrição-Modificação do DNA , Escherichia coli , Bacteriófago T4/genética , Sistemas CRISPR-Cas , Escherichia coli/enzimologia , Escherichia coli/virologia , Genoma Viral
11.
Crit Rev Microbiol ; : 1-12, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39257231

RESUMO

Antimicrobial resistance (AMR) has been recognized as an important health crisis in the twenty first century. Type IV secretion systems (T4SSs) play key roles in the dissemination of AMR plasmids. Novel strategies that combat AMR problem by targeting T4SS sprung up in recent years. Here, we focus on the strategy of male-specific phages that could target and kill bacteria carrying conjugative AMR plasmids encoding T4SSs. We reviewed the recent advances in male-specific phages, including anti-conjugation mechanisms, clinical isolation and identification methods, classification and characteristics, in vitro and in vivo anti-conjugation efficacy and improving strategies. Male-specific phages constitute exciting candidates for developing sustainable anti-resistance biocontrol applications.

12.
Ann Surg Oncol ; 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39283578

RESUMO

BACKGROUND: Performing laparoscopic surgery for T4 colon cancer remains controversial because of concerns about whether its oncologic outcomes are comparable to those of open surgery, and postoperative peritoneal metastasis (PM) has been reported to occur more frequently in laparoscopic colectomy for T4 colon cancer. We investigated whether minimally invasive surgery (MIS) demonstrated a higher PM rate than open surgery and analyzed the risk factors for PM in pT4 colon cancer. METHODS: This study included 392 patients with pT4 colon cancer who underwent curative surgery at a referral hospital between January 2000 and December 2018. Patients with previous neoadjuvant therapy, synchronous malignancy, metastasis, or those who underwent hyperthermic intraperitoneal chemotherapy were excluded. RESULTS: The MIS group had fewer high-risk clinical features, such as tumors too large for endoscope admission or complications like perforation and fistula. The group also exhibited shorter operative time, intraoperative blood loss, multivisceral resection, hospital stay, fewer postoperative complications, smaller tumor size, lower pT4b ratio, and higher pN+ rates. Multivariate analysis revealed that high-risk clinical features, MIS, pT4b, pN+, tumor size < 5 cm, high histological grade, lymphovascular invasion, and postoperative complications were significant risk factors for PM. During the median 59-month follow-up, the 5-year cumulative incidence of PM was elevated in the MIS group (17.5% vs. 8.2%; P = 0.057). No significant differences were observed in the 5-year overall and disease-free survival rates. CONCLUSIONS: Minimally invasive surgery increases the risk of postoperative PM in patients with pT4 colon cancer. Surgeons may require thorough tumor staging and radical resection to prevent PM.

13.
Clin Endocrinol (Oxf) ; 101(1): 69-77, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38630936

RESUMO

OBJECTIVE: Thyroid function tests are common biochemical analyses, and agreement between the routinely used immunoassays is important for diagnosis and monitoring of thyroid disease. Efforts are continuously made to align the biochemical assays, and we aimed to evaluate the agreement between immunoassays used in a clinical laboratory setting among non-pregnant and pregnant adults. DESIGN: Cross-sectional study. PARTICIPANTS: Serum samples were obtained from 192 blood donors (non-pregnant adults) and from 86 pregnant women in the North Denmark Region with no known thyroid disease. MEASUREMENTS: Each sample was used for measurement of thyroid-stimulating hormone (TSH) with the routinely used automatic immunoassays in the regional Departments of Clinical Biochemistry (Alinity, Abbott Laboratories, Cobas, Roche Diagnostics, and Atellica, Siemens Healthineers) and reported as the median with 95% confidence interval (95% CI). RESULTS: In nonpregnant adults, the level of TSH was higher with Cobas and Atellica than with Alinity as reflected by median (Alinity: 1.39 mIU/L (95% CI: 1.30-1.51 mIU/L); Cobas: 1.57 mIU/L (95% CI: 1.48-1.75 mIU/L); Atellica: 1.74 mIU/L (95% CI: 1.61-1.83 mIU/L)). Similarly, a trend was seen towards higher median TSH with Cobas than with Alinity among pregnant women (Alinity: 1.90 mIU/L (95% CI: 1.37-2.82 mIU/L); Cobas: 2.33 mIU/L (95% CI: 1.69-3.62 mIU/L)). CONCLUSION: Results of thyroid function tests obtained with different immunoassays were not interchangeable when evaluated among pregnant and non-pregnant adults. The distinct differences are relevant for clinical decision making and emphasize the necessity of clinical laboratory information when different assays are used for diagnosis and monitoring of patients with thyroid disease.


Assuntos
Testes de Função Tireóidea , Tireotropina , Humanos , Feminino , Gravidez , Testes de Função Tireóidea/normas , Testes de Função Tireóidea/métodos , Adulto , Imunoensaio/métodos , Imunoensaio/normas , Estudos Transversais , Tireotropina/sangue , Dinamarca , Adulto Jovem , Pessoa de Meia-Idade , Masculino
14.
Cytokine ; 182: 156711, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39094437

RESUMO

BACKGROUND: Brucellosis is an economically important infectious caused by most commonly by Brucella. Detection of infected animals at the early stage is important for controlling the disease. The diagnostic antigens, usually protein antigens, have attracted much interest. However, the accurate mechanism of immune response is still unknown. The secretory effectors (BPE005, BPE275, and BPE123) of the type IV secretion system (T4SS) were involved in the intracellular circulation process of Brucella and the immune responses of the host. METHODS: Genes encoding three B. abortus effector proteins (BPE005, BPE275, and BPE123) of T4SS were cloned and the recombinant proteins were expressed and purified. The purified recombinant proteins were named rBPE005, rBPE275 and rBPE123. Then, the expressions of Th1- and Th2-related cytokine genes were analyzed in mice bone marrow-derived macrophages (BMDMs) after stimulation with rBPE005, rBPE275, and rBPE123. Furthermore, four apoptosis-associated genes (Caspase-3, Caspase-8, Bax, and Bcl-2) were also detected to explore the damage of the proteins to the cells. RESULTS: Expressions of all Th1- and Th2-related cytokine genes were induced with three proteins, and different cytokine expression patterns induced by each protein depend on the stimulation time and dose of protein. However, expressions of apoptosis-related genes did not change. CONCLUSION: These results showed that the secreted antigens of Brucella induced an immune reaction via the production of Th1- and Th2-type cytokines in BMDMs without exerting any damage on the cells.


Assuntos
Apoptose , Proteínas de Bactérias , Citocinas , Macrófagos , Proteínas Recombinantes , Sistemas de Secreção Tipo IV , Animais , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Citocinas/metabolismo , Sistemas de Secreção Tipo IV/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Camundongos Endogâmicos BALB C , Brucella abortus/imunologia , Brucelose/imunologia , Brucelose/genética , Feminino , Brucella/imunologia , Células Th1/imunologia
15.
Toxicol Appl Pharmacol ; 487: 116959, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38734151

RESUMO

Pethoxamid (PXA) is a chloroacetamide herbicide that works by inhibiting the germination of target weeds in crops. PXA is not a genotoxic agent, however, in a two-year chronic toxicity study, incidence of thyroid follicular cell hyperplasia was observed in male rats treated at a high dose. Many non-mutagenic chemicals, including agrochemicals are known to produce thyroid hyperplasia in rodents through a hepatic metabolizing enzyme induction mode of action (MoA). In this study, the effects of oral gavage PXA treatment at 300 mg/kg for 7 days on the disposition of intravenously (iv) administered radio-labeled thyroxine ([125I]-T4) was assessed in bile-duct cannulated (BDC) rats. Another group of animals were treated with phenobarbital (PB, 100 mg/kg), a known enzyme inducer, serving as a positive control. The results showed significant increase (p < 0.01) in the mean liver weights in the PB and PXA-treated groups relative to the control group. The serum total T4 radioactivity Cmax and AUC0-4 values for PB and PXA-treated groups were lower than for the control group, suggesting increased clearance from serum. The mean percentages of administered radioactivity excreted in bile were 7.96 ± 0.38%, 16.13 ± 5.46%, and 11.99 ± 2.80% for the control, PB and PXA groups, respectively, indicating increased clearance via the bile in the treated animals. These data indicate that PXA can perturb the thyroid hormone homeostasis in rats by increasing T4 elimination in bile, possibly through enzyme induction mechanism similar to PB. In contrast to humans, the lack of high affinity thyroid binding globulin (TBG) in rats perhaps results in enhanced metabolism of T4 by uridine diphosphate glucuronosyl transferase (UGT). Since this liver enzyme induction MoA for thyroid hyperplasia by PB is known to be rodent specific, PXA effects on thyroid can also be considered not relevant to humans. The data from this study also suggest that incorporating a BDC rat model to determine thyroid hormone disposition using [125I]-T4 is valuable in a thyroid mode of action analysis.


Assuntos
Herbicidas , Fígado , Ratos Sprague-Dawley , Tiroxina , Animais , Tiroxina/sangue , Masculino , Ratos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Herbicidas/toxicidade , Radioisótopos do Iodo , Tamanho do Órgão/efeitos dos fármacos , Fenobarbital/farmacologia , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo , Glândula Tireoide/patologia
16.
Artigo em Inglês | MEDLINE | ID: mdl-39377811

RESUMO

PURPOSE: Trophoblast glycoprotein, the so-called 5T4, is an oncofetal antigen expressed in many different cancers. However, no 5T4-specific radioligand is employed in the clinic for non-invasive diagnosis. Thus, the aim of the current study was to develop a PET radiotracer for imaging 5T4 expression in preclinical and clinical stages. METHODS: A VHH library was constructed by camel immunization. The specificity of the VHHs toward 5T4 antigen was screened through phage display biopanning and periplasmic extract enzyme-linked immunosorbent assay. 1,4,7-Triazacyclononane-1,4,7-triacetate acid (NOTA) derivative was conjugated to the selected VHH. After radiolabeling, microPET/CT and ex vivo biodistribution were conducted using BxPC-3 and MDA-MB-468 tumor-bearing mice. Cold VHH was co-injected with the tracer to challenge its binding in vivo. For the pilot clinical study, PET/CT images were acquired at 1 h after injection of tracer in patients with pathologically confirmed primary and metastatic tumors. RESULTS: A library with a capacity of 1.2 × 1012 colony-forming units was constructed after successful camel immunization. Nb1-40 with a median effect concentration of 0.43 nM was selected. After humanization, the resulting H006 maintained a high affinity towards 5T4. [68Ga]Ga-NOTA-H006 with the molar activities of 6.48-54.2 GBq/µmol was prepared with high radiochemical purity (> 98%). Using [68Ga]Ga-NOTA-H006, microPET/CT revealed a clear visualization of 5T4 expression in BxPC-3 tumor-bearing mice. Ex vivo biodistribution showed that the highest tumor-to-blood ratio (∼ 3-fold) and tumor-to-muscle ratio (∼ 5-fold) were achieved at 60 min post-injection. Co-injection of the cold H006 at a dose of 1.5 mg/kg significantly reduced the tumor uptake (p < 0.0001). In the pilot clinical study, [68Ga]Ga-NOTA-H006 demonstrated its capacity to map 5T4-positive lesions in humans and yielded a mean effective dose of 3.4 × 10- 2 mSv/MBq. CONCLUSIONS: [68Ga]Ga-NOTA-H006, which can visualize 5T4 expression in vivo, has been successfully developed. This opens up opportunities for non-invasively studying 5T4 expression through nuclear medicine. Further clinical investigations are warranted to explore its clinical value in disease progression and companion diagnosis.

17.
Arch Biochem Biophys ; 755: 109939, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38387829

RESUMO

Recent research into membrane interactions has uncovered a diverse range of therapeutic opportunities through the bioengineering of human and non-human macromolecules. Although the majority of this research is focussed on fundamental developments, emerging studies are showcasing promising new technologies to combat conditions such as cancer, Alzheimer's and inflammatory and immune-based disease, utilising the alteration of bacteriophage, adenovirus, bacterial toxins, type 6 secretion systems, annexins, mitochondrial antiviral signalling proteins and bacterial nano-syringes. To advance the field further, each of these opportunities need to be better understood, and the therapeutic models need to be further optimised. Here, we summarise the knowledge and insights into several membrane interactions and detail their current and potential uses therapeutically.

18.
Arch Microbiol ; 206(6): 272, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38772980

RESUMO

Phage-encoded endolysins have emerged as a potential substitute to conventional antibiotics due to their exceptional benefits including host specificity, rapid host killing, least risk of resistance. In addition to their antibacterial potency and biofilm eradication properties, endolysins are reported to exhibit synergism with other antimicrobial agents. In this study, the synergistic potency of endolysins was dissected with antimicrobial peptides to enhance their therapeutic effectiveness. Recombinantly expressed and purified bacteriophage endolysin [T7 endolysin (T7L); and T4 endolysin (T4L)] proteins have been used to evaluate the broad-spectrum antibacterial efficacy using different bacterial strains. Antibacterial/biofilm eradication studies were performed in combination with different antimicrobial peptides (AMPs) such as colistin, nisin, and polymyxin B (PMB) to assess the endolysin's antimicrobial efficacy and their synergy with AMPs. In combination with T7L, polymyxin B and colistin effectively eradicated the biofilm of Pseudomonas aeruginosa and exhibited a synergistic effect. Further, a combination of T4L and nisin displayed a synergistic effect against Staphylococcus aureus biofilms. In summary, the obtained results endorse the theme of combinational therapy consisting of endolysins and AMPs as an effective remedy against the drug-resistant bacterial biofilms that are a serious concern in healthcare settings.


Assuntos
Antibacterianos , Peptídeos Antimicrobianos , Biofilmes , Sinergismo Farmacológico , Endopeptidases , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa , Staphylococcus aureus , Biofilmes/efeitos dos fármacos , Endopeptidases/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/química , Nisina/farmacologia , Nisina/química , Polimixina B/farmacologia , Bacteriófagos , Colistina/farmacologia , Bacteriófago T4/efeitos dos fármacos , Bacteriófago T4/fisiologia , Bacteriófago T7/efeitos dos fármacos , Bacteriófago T7/genética
19.
Int J Colorectal Dis ; 39(1): 54, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38639915

RESUMO

BACKGROUND: Conditional survival (CS) takes into consideration the duration of survival post-surgery and can provide valuable additional insights. The aim of this study was to investigate the risk factors associated with reduced one-year postoperative conditional survival in patients diagnosed with stage III T3-T4 colon cancer and real-time prognosis prediction. Furthermore, we aim to develop pertinent nomograms and predictive models. METHODS: Clinical data and survival outcomes of patients diagnosed with stage III T3-T4 colon cancer were obtained from the Surveillance, Epidemiology, and End Results (SEER) database, covering the period from 2010 to 2019. Patients were divided into training and validation cohorts at a ratio of 7:3. The training set consisted of a total of 11,386 patients for conditional overall survival (cOS) and 11,800 patients for conditional cancer-specific survival (cCSS), while the validation set comprised 4876 patients for cOS and 5055 patients for cCSS. Univariate and multivariate Cox regression analyses were employed to identify independent risk factors influencing one-year postoperative cOS and cCSS. Subsequently, predictive nomograms for cOS and cCSS at 2-year, 3-year, 4-year, and 5-year intervals were constructed based on the identified prognostic factors. The performance of these nomograms was rigorously assessed through metrics including the concordance index (C-index), calibration curves, and the area under curve (AUC) derived from the receiver operating characteristic (ROC) analysis. Clinical utility was further evaluated using decision curve analysis (DCA). RESULTS: A total of 18,190 patients diagnosed with stage III T3-T4 colon cancer were included in this study. Independent risk factors for one-year postoperative cOS and cCSS included age, pT stage, pN stage, pretreatment carcinoembryonic antigen (CEA) levels, receipt of chemotherapy, perineural invasion (PNI), presence of tumor deposits, the number of harvested lymph nodes, and marital status. Sex and tumor site were significantly associated with one-year postoperative cOS, while radiation therapy was notably associated with one-year postoperative cCSS. In the training cohort, the developed nomogram demonstrated a C-index of 0.701 (95% CI, 0.711-0.691) for predicting one-year postoperative cOS and 0.701 (95% CI, 0.713-0.689) for one-year postoperative cCSS. Following validation, the C-index remained robust at 0.707 (95% CI, 0.721-0.693) for one-year postoperative cOS and 0.700 (95% CI, 0.716-0.684) for one-year postoperative cCSS. ROC and calibration curves provided evidence of the model's stability and reliability. Furthermore, DCA underscored the nomogram's superior clinical utility. CONCLUSIONS: Our study developed nomograms and predictive models for postoperative stage III survival in T3-T4 colon cancer with the aim of accurately estimating conditional survival. Survival bias in our analyses may lead to overestimation of survival outcomes, which may limit the applicability of our findings.


Assuntos
Neoplasias do Colo , Humanos , Reprodutibilidade dos Testes , Prognóstico , Neoplasias do Colo/cirurgia , Nomogramas , Área Sob a Curva , Programa de SEER
20.
Colorectal Dis ; 26(8): 1569-1583, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38978153

RESUMO

AIM: Minimally invasive surgery has been increasingly adopted for locally advanced colon cancer. However, evidence comparing robotic (RRC) versus laparoscopic right colectomy (LRC) for nonmetastatic pT4 cancers is lacking. METHODS: This was a multicentre propensity score-matched (PSM) study of a cohort of consecutive patients with pT4 right colon cancer treated with RRC or LRC. The two surgical approaches were compared in terms of R0, number of lymph nodes harvested, intra- and postoperative complication rates, overall (OS), and disease-free survival (DFS). RESULTS: Among a total of 200 patients, 39 RRC were compared with 78 PS-matched LRC patients. The R0 rate was similar between RRC and LRC (92.3% vs. 96.2%, respectively; p = 0.399), as was the odds of retrieving 12 or more lymph nodes (97.4% vs. 96.2%; p = 1). No significant difference was noted for the mean operating time (192.9 min vs. 198.3 min; p = 0.750). However, RRC was associated with fewer conversions to laparotomy (5.1% vs. 20.5%; p = 0.032), less blood loss (36.9 vs. 95.2 mL; p < 0.0001), fewer postoperative complications (17.9% vs. 41%; p = 0.013), a shorter time to flatus (2 vs. 2.8 days; p = 0.009), and a shorter hospital stay (6.4 vs. 9.5 days; p < 0.0001) compared with LRC. These results were confirmed even when converted procedures were excluded from the analysis. The 1-, 3- and 5-year OS (p = 0.757) and DFS (p = 0.321) did not significantly differ between RRC and LRC. CONCLUSION: Adequate oncological outcomes are observed for RRC and LRC performed for pT4 right colon cancer. However, RRC is associated with lower conversion rates and improved short-term postoperative outcomes.


Assuntos
Colectomia , Neoplasias do Colo , Laparoscopia , Complicações Pós-Operatórias , Pontuação de Propensão , Procedimentos Cirúrgicos Robóticos , Humanos , Colectomia/métodos , Neoplasias do Colo/cirurgia , Neoplasias do Colo/patologia , Neoplasias do Colo/mortalidade , Masculino , Feminino , Laparoscopia/métodos , Laparoscopia/estatística & dados numéricos , Procedimentos Cirúrgicos Robóticos/métodos , Idoso , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento , Intervalo Livre de Doença , Duração da Cirurgia , Estadiamento de Neoplasias , Excisão de Linfonodo/métodos , Estudos Retrospectivos , Europa (Continente)
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