Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.145
Filtrar
1.
Proc Natl Acad Sci U S A ; 121(28): e2403034121, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38954547

RESUMO

Nanomaterials acquire a biomolecular corona upon introduction to biological media, leading to biological transformations such as changes in protein function, unmasking of epitopes, and protein fibrilization. Ex vivo studies to investigate the effect of nanoparticles on protein-protein interactions are typically performed in buffer and are rarely measured quantitatively in live cells. Here, we measure the differential effect of silica nanoparticles on protein association in vitro vs. in mammalian cells. BtubA and BtubB are a pair of bacterial tubulin proteins identified in Prosthecobacter strains that self-assemble like eukaryotic tubulin, first into dimers and then into microtubules in vitro or in vivo. Förster resonance energy transfer labeling of each of the Btub monomers with a donor (mEGFP) and acceptor (mRuby3) fluorescent protein provides a quantitative tool to measure their binding interactions in the presence of unfunctionalized silica nanoparticles in buffer and in cells using fluorescence spectroscopy and microscopy. We show that silica nanoparticles enhance BtubAB dimerization in buffer due to protein corona formation. However, these nanoparticles have little effect on bacterial tubulin self-assembly in the complex mammalian cellular environment. Thus, the effect of nanomaterials on protein-protein interactions may not be readily translated from the test tube to the cell in the absence of particle surface functionalization that can enable targeted protein-nanoparticle interactions to withstand competitive binding in the nanoparticle corona from other biomolecules.


Assuntos
Proteínas de Bactérias , Nanopartículas , Dióxido de Silício , Tubulina (Proteína) , Tubulina (Proteína)/metabolismo , Tubulina (Proteína)/química , Nanopartículas/química , Dióxido de Silício/química , Dióxido de Silício/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Transferência Ressonante de Energia de Fluorescência , Humanos , Microtúbulos/metabolismo , Multimerização Proteica , Ligação Proteica
2.
Elife ; 132024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38949652

RESUMO

Tubulin posttranslational modifications (PTMs) modulate the dynamic properties of microtubules and their interactions with other proteins. However, the effects of tubulin PTMs were often revealed indirectly through the deletion of modifying enzymes or the overexpression of tubulin mutants. In this study, we directly edited the endogenous tubulin loci to install PTM-mimicking or -disabling mutations and studied their effects on microtubule stability, neurite outgrowth, axonal regeneration, cargo transport, and sensory functions in the touch receptor neurons of Caenorhabditis elegans. We found that the status of ß-tubulin S172 phosphorylation and K252 acetylation strongly affected microtubule dynamics, neurite growth, and regeneration, whereas α-tubulin K40 acetylation had little influence. Polyglutamylation and detyrosination in the tubulin C-terminal tail had more subtle effects on microtubule stability likely by modulating the interaction with kinesin-13. Overall, our study systematically assessed and compared several tubulin PTMs for their impacts on neuronal differentiation and regeneration and established an in vivo platform to test the function of tubulin PTMs in neurons.


Assuntos
Caenorhabditis elegans , Microtúbulos , Processamento de Proteína Pós-Traducional , Tubulina (Proteína) , Animais , Tubulina (Proteína)/metabolismo , Tubulina (Proteína)/genética , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Microtúbulos/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Acetilação , Axônios/metabolismo , Axônios/fisiologia , Fosforilação , Regeneração Nervosa , Cinesinas/metabolismo , Cinesinas/genética
3.
Drug Dev Res ; 85(4): e22224, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38867474

RESUMO

The mammalian cytoplasmic protein SIRT2, a class III histone deacetylase family member, possesses NAD+-dependent lysine deacetylase/deacylase activity. Dysregulation of SIRT2 has been implicated in the pathogenesis of several diseases, including neurological and metabolic disorders and cancer; thus, SIRT2 emerges as a potential therapeutic target. Herein, we identified a series of diaryl acetamides (ST61-ST90) by the structural optimization of our hit STH2, followed by enhanced SIRT2 inhibitory potency and selectivity. Among them, ST72, ST85, and ST88 selectively inhibited SIRT2 with IC50 values of 9.97, 5.74, and 8.92 µM, respectively. Finally, the entire study was accompanied by in silico prediction of binding modes of docked compounds and the stability of SIRT2-ligand complexes. We hope our findings will provide substantial information for designing selective inhibitors of SIRT2.


Assuntos
Acetamidas , Sirtuína 2 , Sirtuína 2/antagonistas & inibidores , Sirtuína 2/química , Sirtuína 2/metabolismo , Humanos , Acetamidas/química , Acetamidas/farmacologia , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/química
4.
Cancer Lett ; 597: 217011, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38849011

RESUMO

BACKGROUND: Improving survival for patients diagnosed with metastatic disease and overcoming chemoresistance remain significant clinical challenges in treating breast cancer. Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by a lack of therapeutically targetable receptors (ER/PR/HER2). TNBC therapy includes a combination of cytotoxic chemotherapies, including microtubule-targeting agents (MTAs) like paclitaxel (taxane class) or eribulin (vinca class); however, there are currently no FDA-approved MTAs that bind to the colchicine-binding site. Approximately 70 % of patients who initially respond to paclitaxel will develop taxane resistance (TxR). We previously reported that an orally bioavailable colchicine-binding site inhibitor (CBSI), VERU-111, inhibits TNBC tumor growth and treats pre-established metastatic disease. To further improve the potency and metabolic stability of VERU-111, we created next-generation derivatives of its scaffold, including 60c. RESULTS: 60c shows improved in vitro potency compared to VERU-111 for taxane-sensitive and TxR TNBC models, and suppress TxR primary tumor growth without gross toxicity. 60c also suppressed the expansion of axillary lymph node metastases existing prior to treatment. Comparative analysis of excised organs for metastasis between 60c and VERU-111 suggested that 60c has unique anti-metastatic tropism. 60c completely suppressed metastases to the spleen and was more potent to reduce metastatic burden in the leg bones and kidney. In contrast, VERU-111 preferentially inhibited liver metastases and lung metastasis repression was similar. Together, these results position 60c as an additional promising CBSI for TNBC therapy, particularly for patients with TxR disease.

5.
Sci Rep ; 14(1): 13797, 2024 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877139

RESUMO

In filamentous fungi, microtubules are important for polar growth and morphological maintenance and serve as rails for intracellular trafficking. The molecular mechanisms associated with microtubules have been analyzed. However, little is known about when and where tubulin, a component of microtubules, is biosynthesized in multinuclear and multicellular filamentous fungi. In this study, we visualized microtubules based on the enhanced green fluorescence protein (EGFP)-labeled α-tubulin and ß-tubulin mRNA tagged by the EGFP-mediated MS2 system in living yellow Koji mold Aspergillus oryzae cells in order to understand the spatiotemporal production mechanism of tubulin. We found that mRNA of btuA, encoding for ß-tubulin, localized at dot-like structures through the apical, middle and basal regions of the hyphal cells. In addition, some btuA mRNA dots showed microtubule-dependent motor protein-like dynamics in the cells. Furthermore, it was found that btuA mRNA dots were decreased in the cytoplasm just before mitosis but increased immediately after mitosis, followed by a gradual decrease. In summary, the localization and abundance of ß-tubulin mRNA is spatiotemporally regulated in living A. oryzae hyphal cells.


Assuntos
Aspergillus oryzae , Microtúbulos , RNA Mensageiro , Tubulina (Proteína) , Aspergillus oryzae/genética , Aspergillus oryzae/metabolismo , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Microtúbulos/metabolismo , Hifas/genética , Hifas/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo
6.
Biochim Biophys Acta Mol Cell Res ; 1871(7): 119770, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38897390

RESUMO

Microtubule stabilization is critical for axonal growth and regeneration, and many microtubule-associated proteins are involved in this process. In this study, we found that the knockdown of echinoderm microtubule-associated protein-like 1 (EML1) hindered axonal growth in cultured cortical and dorsal root ganglion neurons. We further revealed that EML1 facilitated the acetylation of microtubules and that the impairment of axonal growth due to EML1 inhibition could be restored by treatment with deacetylase inhibitors, suggesting that EML1 affected tubulin acetylation. Moreover, we verified an interaction between EML1 and the alpha-tubulin acetyltransferase 1, which is responsible for the acetylation of alpha-tubulin. We thus proposed that EML1 might regulate microtubule acetylation and stabilization via alpha-tubulin acetyltransferase 1 and then promote axon growth. Finally, we verified that the knockdown of EML1 in vivo also inhibited sciatic nerve regeneration. Our findings revealed a novel effect of EML1 on microtubule acetylation during axonal regeneration.

7.
Eur J Med Chem ; 275: 116611, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38901104

RESUMO

The identification of chemically different inhibitors that target the colchicine site of tubulin is still of great value for cancer treatment. Combretastatin A-4(CA-4), a naturally occurring colchicine-site binder characterized by its structural simplicity and biological activity, has served as a structural blueprint for the development of novel analogues with improved safety and therapeutic efficacy. In this study, a library of forty-eight 4-phenyl-5-quinolinyl substituted triazole, pyrazole or isoxazole analouges of CA-4, were synthesized and evaluated for their cytotoxicity against Esophageal Squamous Cell Carcinoma (ESCC) cell lines. Compound C11, which features a 2-methyl substitution at the quinoline and carries an isoxazole ring, emerged as the most promising, with 48 h IC50s of less than 20 nmol/L against two ESCC cell lines. The findings from EBI competitive assay, CETA, and in vitro tubulin polymerization assay of C11 are consistent with those of the positive control colchicine, demonstrating the clear affinity of compound C11 to the colchicine binding site. The subsequent cellular-based mechanism studies revealed that C11 significantly inhibited ESCC cell proliferation, arrested cell cycle at the M phase, induced apoptosis, and impeded migration. Experiments conducted in vivo further confirmed that C11 effectively suppressed the growth of ESCC without showing any toxicity towards the selected animal species. Overall, our research suggests that the tubulin polymerization inhibitor incorporating quinoline and the isoxazole ring may deserve consideration for cancer therapy.

8.
J Enzyme Inhib Med Chem ; 39(1): 2367139, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38904149

RESUMO

Estradiol dimers (EDs) possess significant anticancer activity by targeting tubulin dynamics. In this study, we synthesised 12 EDs variants via copper-catalysed azide-alkyne cycloaddition (CuAAC) reaction, focusing on structural modifications within the aromatic bridge connecting two estradiol moieties. In vitro testing of these EDs revealed a marked improvement in selectivity towards cancerous cells, particularly for ED1-8. The most active compounds, ED3 (IC50 = 0.38 µM in CCRF-CEM) and ED5 (IC50 = 0.71 µM in CCRF-CEM) demonstrated cytotoxic effects superior to 2-methoxyestradiol (IC50 = 1.61 µM in CCRF-CEM) and exhibited anti-angiogenic properties in an endothelial cell tube-formation model. Cell-based experiments and in vitro assays revealed that EDs interfere with mitotic spindle assembly. Additionally, we proposed an in silico model illustrating the probable binding modes of ED3 and ED5, suggesting that dimers with a simple linker and a single substituent on the aromatic central ring possess enhanced characteristics compared to more complex dimers.


Assuntos
Antineoplásicos , Proliferação de Células , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Estradiol , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Estradiol/farmacologia , Estradiol/química , Estradiol/síntese química , Estrutura Molecular , Relação Estrutura-Atividade , Proliferação de Células/efeitos dos fármacos , Dimerização , Química Click , Linhagem Celular Tumoral
9.
Bioorg Chem ; 150: 107569, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38905886

RESUMO

Erianin, a natural compound derived from Dendrobium, has shown significant anticancer properties against a wide range of cancer cells. Despite the identification of multiple mechanisms of action for erianin, none of these mechanisms fully account for its broad-spectrum effect. In this study, we aimed to identify the cellular target and underlying mechanism responsible for the broad-spectrum antitumor effects of erianin. We found that erianin effectively inhibited tubulin polymerization in cancer cells and purified tubulin. Through competition binding assays and X-ray crystallography, it was revealed that erianin bound to the colchicine site of ß-tubulin. Importantly, the X-ray crystal structure of the tubulin-erianin complex was solved, providing clear insight into the orientation and position of erianin in the colchicine-binding site. Erianin showed activity against paclitaxel-resistant cells, evidenced by G2/M cell cycle arrest, apoptosis-related PARP and Caspase-3 cleavage, and in vivo xenograft studies. The study concluded that erianin bound reversibly to the colchicine site of ß-tubulin, inhibited tubulin polymerization, and displayed anticancer activity against paclitaxel-resistant cells, offering valuable insights for further exploration as potential anticancer agents.

10.
Neurosci Lett ; 836: 137870, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38852764

RESUMO

Depression is considered a crucial psychiatric disease correlated with neuronal-dysfunctions induced by stress-stimuli. This study aimed to investigate effect of Fluoxetine (FL) on chronic unpredictable mild stress (CUMS) and explore the associated mechanisms. CUMS rat model was established by treating with lots of stresses. CUMS rats were administered FL, SB216763 (SB), Wortmannin (WT) alone or in combination. CUMS rats were administered 1 % sugar water to conduct sugar water consumption experiment. Acet-Tub, Tyr-Tub, tau46, p-tau-Ser199/202, p-tau-Ser396, p-tau-Ser231, expression was examined using immunohistochemical assay and western blotassay. Interaction between tau and tubulin was evaluated with immunoprecipitation assay. Double immunohistochemical assay was used to identify interaction between Nestin and Tau. The results indicated that FL treatment only increased sugar consumption of CUMS rats (P < 0.05), but also strengthened effects of SB and WT. FL significantly treatment decreased tau phosphorylation (p-tau) in hippocampal tissues of rats compared to those of rats in CUMS group (P < 0.05). FL treatment markedly decreased Acet-Tub and increased Tyr-Tub expression in hippocampal tissues of rats compared to those of rats in CUMS group (P < 0.05). The effects of FL treatment on p-tau down-regulation and tubulin modulation in hippocampal tissues were independent from PI3K and GSK-3 signaling pathways. FL treatment could also enhance proliferation and total tau of newborn neurons of CUMS rats. FL treatment strengthened interaction between tau and botulin in hippocampal tissues of CUMS rats. In conclusion, Fluoxetin suppressed phosphorylation of tau and modulated the interaction between tau and tubulin in hippocampus of adult CUMS rats.

11.
Int J Mol Sci ; 25(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38892135

RESUMO

Podophyllotoxin (PPT) is an active pharmaceutical ingredient (API) with established antitumor potential. However, due to its systemic toxicity, its use is restricted to topical treatment of anogenital warts. Less toxic PPT derivatives (e.g., etoposide and teniposide) are used intravenously as anticancer agents. PPT has been exploited as a scaffold of new potential therapeutic agents; however, fewer studies have been conducted on the parent molecule than on its derivatives. We have undertaken a study of ultrastructural changes induced by PPT on HaCaT keratinocytes. We have also tracked the intracellular localization of PPT using its fluorescent derivative (PPT-FL). Moreover, we performed molecular docking of both PPT and PPT-FL to compare their affinity to various binding sites of tubulin. Using the Presto blue viability assay, we established working concentrations of PPT in HaCaT cells. Subsequently, we have used selected concentrations to determine PPT effects at the ultrastructural level. Dynamics of PPT distribution by confocal microscopy was performed using PPT-FL. Molecular docking calculations were conducted using Glide. PPT induces a time-dependent cytotoxic effect on HaCaT cells. Within 24 h, we observed the elongation of cytoplasmic processes, formation of cytoplasmic vacuoles, progressive ER stress, and shortening of the mitochondrial long axis. After 48 h, we noticed disintegration of the cell membrane, progressive vacuolization, apoptotic/necrotic vesicles, and a change in the cell nucleus's appearance. PPT-FL was detected within HaCaT cells after ~10 min of incubation and remained within cells in the following measurements. Molecular docking confirmed the formation of a stable complex between tubulin and both PPT and PPT-FL. However, it was formed at different binding sites. PPT is highly toxic to normal human keratinocytes, even at low concentrations. It promptly enters the cells, probably via endocytosis. At lower concentrations, PPT causes disruptions in both ER and mitochondria, while at higher concentrations, it leads to massive vacuolization with subsequent cell death. The novel derivative of PPT, PPT-FL, forms a stable complex with tubulin, and therefore, it is a useful tracker of intracellular PPT binding and trafficking.


Assuntos
Células HaCaT , Queratinócitos , Simulação de Acoplamento Molecular , Podofilotoxina , Tubulina (Proteína) , Humanos , Podofilotoxina/análogos & derivados , Podofilotoxina/farmacologia , Podofilotoxina/química , Tubulina (Proteína)/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Corantes Fluorescentes/química , Sítios de Ligação , Estresse do Retículo Endoplasmático/efeitos dos fármacos
12.
Int J Mol Sci ; 25(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38892342

RESUMO

The synthesis of biphenylmethoxydibenzo[b,f]oxepine or photoswitchable fluorinated dibenzo[b,f]oxepine derivatives with one or three azo bonds, potential microtubule inhibitors, is described. Our studies provide a concise method for constructing derivatives containing the dibenzo[b,f]oxepine skeleton. An analysis of products was run using experimental and theoretical methods. Next, we evaluated the E/Z isomerization of azo-dibenzo[b,f]oxepine derivatives, which could be photochemically controlled using visible-wavelength light.


Assuntos
Moduladores de Tubulina , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/farmacologia , Moduladores de Tubulina/química , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Estrutura Molecular
13.
Bioorg Med Chem ; 109: 117794, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38875875

RESUMO

Dolastatin 10 (Dol-10), a natural marine-source pentapeptide, is a powerful antimitotic agent regarded as one of the most potent anticancer compounds found to date. Dol-10 however, lacks chemical conjugation capabilities, which restricts the feasibility of its application in targeted drug therapy. This limitation has spurred the prospect that chemical structure of the parent molecule might allow conjugation of the derivatives to drug carriers such as antibodies. By first employing docking studies, we designed and prepared a series of novel Dol-10 analogs with a modified C-terminus, preserving high potency of the parent compound while enhancing conjugation capability. The modifications involved the introduction of a methyleneamine functionality at position 4 of the 1,3-thiazole ring, along with the substitution of the thiazole ring with a 1,2,3-triazole moiety, furnished with methylenehydroxy, carboxy, methyleneamine, and N(Me)-methyleneamine tethering functionalities at position 4. Among the synthesized pentapeptides, DA-1 exhibited the highest potency in prostate cancer (PC-3) cells, eliciting apoptosis (IC50 0.2 ± 0.1 nm) and cell cycle arrest at the mitotic stage after at least 6 days of culture. This delayed response suggests the accumulation of cellular stress or significant physiological alterations that profoundly impact the cell cycle. We believe that these novel Dol-10 derivates represent a new and straightforward route for the development of C-terminus modified Dol-10-based microtubule inhibitors, thereby advancing targeted anticancer therapy.


Assuntos
Antineoplásicos , Proliferação de Células , Depsipeptídeos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Relação Estrutura-Atividade , Depsipeptídeos/química , Depsipeptídeos/farmacologia , Depsipeptídeos/síntese química , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Estrutura Molecular , Relação Dose-Resposta a Droga , Simulação de Acoplamento Molecular , Apoptose/efeitos dos fármacos , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/síntese química
14.
Gynecol Oncol ; 188: 60-70, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38936282

RESUMO

OBJECTIVE: Ovarian cancer, a leading cause of cancer-related deaths in women, remains a formidable challenge, especially in the context of platinum-resistant disease. This study investigated the potential of the benzimidazole derivative BNZ-111 as a novel treatment strategy for platinum-resistant ovarian cancer. METHODS: The human EOC cell lines A2780, HeyA8, SKOV3ip1, A2780-CP20, HeyA8-MDR, and SKOV3-TR were treated with BNZ-111, and cell proliferation, apoptosis, and cell cycle were assessed. RESULTS: It demonstrated strong cytotoxicity in both chemo-sensitive and chemo-resistant epithelial ovarian cancer cell lines, inducing apoptosis and G2/M cell cycle arrest. In vivo experiments using orthotopic and patient-derived xenograft models showed significant tumor growth inhibition without apparent toxicity to vital organs. Unlike paclitaxel, BNZ-111 proved effective in paclitaxel-resistant cells, potentially by bypassing interaction with MDR1 and modulating ß-3 tubulin expression to suppress microtubule dynamics. CONCLUSION: BNZ-111, with favorable drug-like properties, holds promise as a therapeutic option for platinum-resistant ovarian cancer, addressing a critical clinical need in gynecologic oncology.

15.
Vet Parasitol Reg Stud Reports ; 52: 101036, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38880561

RESUMO

Ancylostoma caninum is a widely prevalent parasitic nematode in dogs across the world. There has been a notable increase in reports of anthelmintic resistance in A. caninum within the United States of America in recent years, which has led us to investigate the potential of this scenario in Canada. The study objectives were to assess the prevalence of A. caninum in two different groups, including a colony of rescued dogs in Canada and three imported Greyhound dogs from USA, and to evaluate the efficacy of two benzimidazole (BZ) anthelmintics against A. caninum, complemented with a molecular genetic analysis adapted to low prevalence. Fecal samples were collected at pre- and post-treatment with fenbendazole for the native shelters-origin group, and a combination of anthelmintic formulations, including the pro-BZ febantel for the USA-origin group. The coprology analyses found several genera of internal parasites. Canine ancylostomiasis was the most prevalent parasitosis with 30.77% in the native group and 100% in the USA group, but with overall low average of A. caninum eggs per gram. Through the fecal egg count reduction test (FECRT), applying a cut-off at 90% as baseline of egg reduction for successful efficacy, BZ showed variable efficacy. Furthermore, molecular analysis confirmed the presence of A. caninum in both groups of dogs and found differences in the genetics linked to BZ resistance on the A. caninum ß-tubulin isotype 1 gene. In the isolate from the native group, both codons 167 and 200 were homozygous without the presence of single nucleotide polymorphism (SNP). In contrast, the selected isolate from the USA group, showed a homozygous allele at position 200 and a heterozygous SNP at position 167. The latter was congruent with the low efficacy in FECRT and agrees with the recent findings of USA A. caninum isolate resistant phenotype to the BZ anthelmintics. The limitations of the study include an overall low eggs-per-gram in both canine groups, and the shortage of additional fecal samples from the USA group, restraining the molecular analysis only to one out of the three Greyhounds. This study provided some insights on the efficacy of BZs against A. caninum and revealed the presence of BZ resistant isolates in imported dogs in Quebec, Canada. All this information should be considered, for choosing the best strategy in the control of A. caninum using anthelmintic drugs.


Assuntos
Ancylostoma , Ancilostomíase , Anti-Helmínticos , Benzimidazóis , Doenças do Cão , Resistência a Medicamentos , Fezes , Animais , Cães , Doenças do Cão/parasitologia , Doenças do Cão/tratamento farmacológico , Doenças do Cão/epidemiologia , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Ancylostoma/efeitos dos fármacos , Ancylostoma/isolamento & purificação , Ancylostoma/genética , Ancilostomíase/veterinária , Ancilostomíase/tratamento farmacológico , Ancilostomíase/epidemiologia , Ancilostomíase/parasitologia , Anti-Helmínticos/uso terapêutico , Anti-Helmínticos/farmacologia , Fezes/parasitologia , Quebeque/epidemiologia , Prevalência , Feminino , Masculino
16.
bioRxiv ; 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38826480

RESUMO

One of the defining features of apicomplexan parasites is their cytoskeleton composed of alveolar vesicles, known as the inner membrane complex (IMC) undergirded by intermediate-like filament network and an array of subpellicular microtubules (SPMTs). In Toxoplasma gondii, this specialized cytoskeleton is involved in all aspects of the disease-causing lytic cycle, and notably acting as a scaffold for parasite offspring in the internal budding process. Despite advances in our understanding of the architecture and molecular composition, insights pertaining to the coordinated assembly of the scaffold are still largely elusive. Here, T. gondii tachyzoites were dissected by advanced, iterative expansion microscopy (pan-ExM) revealing new insights into the very early sequential formation steps of the tubulin scaffold. A comparative study of the related parasite Sarcocystis neurona revealed that different MT bundling organizations of the nascent SPMTs correlate with the number of central and basal alveolar vesicles. In absence of a so far identified MT nucleation mechanism, we genetically dissected T. gondii γ-tubulin and γ-tubulin complex protein 4 (GCP4). While γ-tubulin depletion abolished the formation of the tubulin scaffold, a set of MTs still formed that suggests SPMTs are nucleated at the outer core of the centrosome. Depletion of GCP4 interfered with the correct assembly of SPMTs into the forming daughter buds, further indicating that the parasite utilizes the γ-tubulin complex in tubulin scaffold formation .

17.
Pest Manag Sci ; 2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38853401

RESUMO

Pyridachlometyl is a novel tubulin dynamics modulator fungicide developed by Sumitomo as a new agent designed to tackle fungicide resistance. Pyridachlometyl is being developed as a first-in-class molecule with an anti-tubulin mode of action, the chemical structure of which is characterized by a unique tetrasubstituted pyridazine ring. The first commercial product 'Fuseki flowable' received initial registration in 2023 in Japan. The concepts of the discovery project, optimization of chemical structures, and biological profiles are reviewed herein. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

18.
Animals (Basel) ; 14(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38891592

RESUMO

Soil-transmitted helminth (STH) infections, commonly treated with benzimidazoles, are linked to resistance through single nucleotide polymorphisms (SNPs) at position 167, 198, or 200 in the ß-tubulin isotype 1 gene. The aim of this study was to establish a novel genotyping assay characterized by its rapidity and specificity. This assay was designed to detect the presence of SNPs within the partial ß-tubulin gene of Trichuris trichiura. This was achieved through the biallelic discrimination at codons 167, 198, and 200 by employing the competitive binding of two allele-specific forward primers. The specificity and reliability of this assay were subsequently confirmed using Trichuris samples isolated from captive primates. Furthermore, a molecular study was conducted to substantiate the utility of the ß-tubulin gene as a molecular marker. The assays showed high sensitivity and specificity when applied to field samples. Nevertheless, none of the SNPs within the ß-tubulin gene were detected in any of the adult worms or eggs from the analyzed populations. All specimens consistently displayed an SS genotype. The examination of the ß-tubulin gene further validated the established close relationships between the T. trichiura clade and Trichuris suis clade. This reaffirms its utility as a marker for phylogenetic analysis.

19.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(3): 569-576, 2024 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-38932544

RESUMO

Tumor treatment fields (TTFields) can effectively inhibit the proliferation of tumor cells, but its mechanism remains exclusive. The destruction of cellular microtubule structure caused by TTFields through electric field force is considered to be the main reason for inhibiting tumor cell proliferation. However, the validity of this hypothesis still lacks exploration at the mesoscopic level. Therefore, in this study, we built force models for tubulins subjected to TTFields, based on the physical and electrical properties of tubulin molecules. We theoretically analyzed and simulated the dynamic effects of electric field force and torque on tubulin monomer polymerization, as well as the alignment and orientation of α/ß tubulin heterodimer, respectively. Research results indicate that the interference of electric field force induced by TTFields on tubulin monomer is notably weaker than the inherent electrostatic binding force among tubulin monomers. Additionally, the electric field torque generated by the TTFileds on α/ß tubulin dimers is also difficult to affect their random alignment. Therefore, at the mesoscale, our study affirms that TTFields are improbable to destabilize cellular microtubule structures via electric field dynamics effects. These results challenge the traditional view that TTFields destroy the microtubule structure of cells through TTFields electric field force, and proposes a new approach that should pay more attention to the "non-mechanical" effects of TTFields in the study of TTFields mechanism. This study can provide reliable theoretical basis and inspire new research directions for revealing the mesoscopic bioelectrical mechanism of TTFields.


Assuntos
Microtúbulos , Neoplasias , Tubulina (Proteína) , Tubulina (Proteína)/metabolismo , Microtúbulos/metabolismo , Humanos , Neoplasias/terapia , Proliferação de Células , Eletricidade Estática , Polimerização , Campos Eletromagnéticos
20.
Cureus ; 16(5): e61132, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38919239

RESUMO

TUBG1, a tubulin gene, plays an important role in neurodevelopment. Here we describe a case of a novel TUGB1 mutation (NM_001070.4:c.821C>T) (p.Thr274Ile). This patient presented similarly to previous cases with features including microcephaly, epilepsy, and speech and motor delay. Unique characteristics were also present such as trigonocephaly, tethered frenulum, scoliosis, nystagmus, and a concurrent FBXW7 mutation. This case expands our breadth of knowledge on TUBG1 genotypic and phenotypic variation. However, further work is needed to fully understand this rare mutation and the associations between TUBG1 and FBXW7 mutations.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...