Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 16.722
Filtrar
1.
JCO Precis Oncol ; 8: e2300634, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38662984

RESUMO

PURPOSE: While 177Lu-PSMA-617 (LuPSMA) is an effective therapy for many patients with metastatic castration-resistant prostate cancer (mCRPC), biomarkers associated with outcomes are not well defined. We hypothesized that prostate cancer mutational profile may associate with clinical activity of LuPSMA. We devised a study to evaluate associations between mCRPC mutational profile with LuPSMA clinical outcomes. METHODS: This was a multicenter retrospective analysis of patients with mCRPC with next-generation sequencing (NGS) who received LuPSMA. PSA50 response (ie, ≥50% decline in prostate-specific antigen [PSA]) rate, PSA progression free survival (PSA PFS), and overall survival (OS) were compared between genetically defined subgroups. RESULTS: One hundred twenty-six patients with NGS results who received at least one cycle of LuPSMA were identified. The median age was 73 (IQR, 68-78) years, 124 (98.4%) received ≥1 prior androgen receptor-signaling inhibitor, and 121 (96%) received ≥1 taxane-based chemotherapy regimen. Fifty-eight (46%) patients with a DNA damage repair gene mutation (DNA damage response group) and 59 (46.8%) with a mutation in TP53, RB1, or PTEN tumor suppressor genes (TSG group) were identified. After adjusting for relevant confounders, the presence of ≥1 TSG mutation was associated with shorter PSA PFS (hazard ratio [HR], 1.93 [95% CI, 1.05 to 3.54]; P = .034) and OS (HR, 2.65 [95% CI, 1.15 to 6.11]; P = .023). There was improved OS favoring the DNA damage response group (HR, 0.37 [95% CI, 0.14 to 0.97]; P = .044) on multivariable analysis. Univariate analysis of patients with ATM mutations had significantly higher rates of PSA50 response, PSA PFS, and OS. CONCLUSION: Outcomes on LuPSMA varied on the basis of mutational profile. Prospective studies to define the clinical activity of LuPSMA in predefined genomic subgroups are justified.


Assuntos
Dipeptídeos , Lutécio , Neoplasias de Próstata Resistentes à Castração , Humanos , Masculino , Estudos Retrospectivos , Idoso , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Lutécio/uso terapêutico , Dipeptídeos/uso terapêutico , Compostos Heterocíclicos com 1 Anel/uso terapêutico , Antígeno Prostático Específico/sangue , Antígenos de Superfície/genética , Estudos de Coortes , Glutamato Carboxipeptidase II/genética
2.
Cells ; 13(8)2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38667323

RESUMO

Bladder cancer aggressiveness is correlated with abnormal N-cadherin transmembrane glycoprotein expression. This protein is cleaved by the metalloprotease ADAM10 and the γ-secretase complex releasing a pro-angiogenic N-terminal fragment (NTF) and a proliferation-activating soluble C-terminal fragment (CTF2). Tetraspanin 15 (Tspan15) is identified as an ADAM10-interacting protein to induce selective N-cadherin cleavage. We first demonstrated, in invasive T24 bladder cancer cells, that N-cadherin was cleaved by ADAM10 generating NTF in the extracellular environment and leaving a membrane-anchored CTF1 fragment and that Tspan15 is required for ADAM10 to induce the selective N-cadherin cleavage. Targeting N-cadherin function in cancer is relevant to preventing tumor progression and metastases. For antitumor molecules to inhibit N-cadherin function, they should be complete and not cleaved. We first showed that the GW501516, an agonist of the nuclear receptor PPARß/δ, decreased Tspan15 and prevented N-cadherin cleavage thus decreasing NTF. Interestingly, the drug did not modify ADAM10 expression, which was important because it could limit side effects since ADAM10 cleaves numerous substrates. By targeting Tspan15 to block ADAM10 activity on N-cadherin, GW501516 could prevent NTF pro-tumoral effects and be a promising molecule to treat bladder cancer. More interestingly, it could optimize the effects of the N-cadherin antagonists those such as ADH-1 that target the N-cadherin ectodomain.


Assuntos
Proteína ADAM10 , Secretases da Proteína Precursora do Amiloide , Antígenos CD , Caderinas , Dipeptídeos , Ácidos Hidroxâmicos , Proteínas de Membrana , Tetraspaninas , Neoplasias da Bexiga Urinária , Humanos , Proteína ADAM10/metabolismo , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/genética , Tetraspaninas/metabolismo , Tetraspaninas/genética , Caderinas/metabolismo , Linhagem Celular Tumoral , Secretases da Proteína Precursora do Amiloide/metabolismo , Proteínas de Membrana/metabolismo , Invasividade Neoplásica , Proteólise/efeitos dos fármacos
3.
Proc Natl Acad Sci U S A ; 121(17): e2307814121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38621131

RESUMO

Efforts to genetically reverse C9orf72 pathology have been hampered by our incomplete understanding of the regulation of this complex locus. We generated five different genomic excisions at the C9orf72 locus in a patient-derived induced pluripotent stem cell (iPSC) line and a non-diseased wild-type (WT) line (11 total isogenic lines), and examined gene expression and pathological hallmarks of C9 frontotemporal dementia/amyotrophic lateral sclerosis in motor neurons differentiated from these lines. Comparing the excisions in these isogenic series removed the confounding effects of different genomic backgrounds and allowed us to probe the effects of specific genomic changes. A coding single nucleotide polymorphism in the patient cell line allowed us to distinguish transcripts from the normal vs. mutant allele. Using digital droplet PCR (ddPCR), we determined that transcription from the mutant allele is upregulated at least 10-fold, and that sense transcription is independently regulated from each allele. Surprisingly, excision of the WT allele increased pathologic dipeptide repeat poly-GP expression from the mutant allele. Importantly, a single allele was sufficient to supply a normal amount of protein, suggesting that the C9orf72 gene is haplo-sufficient in induced motor neurons. Excision of the mutant repeat expansion reverted all pathology (RNA abnormalities, dipeptide repeat production, and TDP-43 pathology) and improved electrophysiological function, whereas silencing sense expression did not eliminate all dipeptide repeat proteins, presumably because of the antisense expression. These data increase our understanding of C9orf72 gene regulation and inform gene therapy approaches, including antisense oligonucleotides (ASOs) and CRISPR gene editing.


Assuntos
Esclerose Amiotrófica Lateral , Demência Frontotemporal , Humanos , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Alelos , Esclerose Amiotrófica Lateral/metabolismo , Demência Frontotemporal/metabolismo , Neurônios Motores/metabolismo , Mutação , Expansão das Repetições de DNA/genética , Dipeptídeos/metabolismo
4.
Zhongguo Zhong Yao Za Zhi ; 49(5): 1172-1185, 2024 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-38621964

RESUMO

Cyclopeptides isolated from a variety of plants are a class of cyclic nitrogen-containing compounds, and they are primarily formed by peptide bonds between amino acids, generally containing 2 to 37 L-configuration encoded or non-encoded amino acid residues. Cyclopeptides have significant values in scientific research as natural small-molecule metabolites produced by plants. The available studies have revealed that such natural products are ubiquitous in plants, which mainly include cyclic dipeptides, cyclic tetrapeptides, cyclic pentapeptides, cyclic hexapeptides, cyclic heptapeptides, cyclic octapeptides, cyclic nonapeptides, and cyclic decapeptides. Among them, cyclic dipeptides, cyclic hexapeptides, and cyclic octapeptides are the major active compounds. It has been reported that plant cyclopeptides have novel and unique chemical structures. They possess diverse pharmacological activities, such as antineoplastic, antimicrobial, antimalarial, anti-inflammatory, and antiviral activities. This paper summarizes the research achievements of plant cyclopeptides since 2006, aiming to provide theoretical reference for the research and application of plant cyclopeptides in medicine, health, and agriculture fields.


Assuntos
Anti-Infecciosos , Antineoplásicos , Peptídeos Cíclicos/química , Antineoplásicos/farmacologia , Anti-Infecciosos/farmacologia , Dipeptídeos
5.
Int J Mol Sci ; 25(7)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38612472

RESUMO

Birinapant, an antagonist of the inhibitor of apoptosis proteins, upregulates MHCs in tumor cells and displays a better tumoricidal effect when used in combination with immune checkpoint inhibitors, indicating that Birinapant may affect the antigen presentation pathway; however, the mechanism remains elusive. Based on high-resolution mass spectrometry and in vitro and in vivo models, we adopted integrated genomics, proteomics, and immunopeptidomics strategies to study the mechanism underlying the regulation of tumor immunity by Birinapant from the perspective of antigen presentation. Firstly, in HT29 and MCF7 cells, Birinapant increased the number and abundance of immunopeptides and source proteins. Secondly, a greater number of cancer/testis antigen peptides with increased abundance and more neoantigens were identified following Birinapant treatment. Moreover, we demonstrate the existence and immunogenicity of a neoantigen derived from insertion/deletion mutation. Thirdly, in HT29 cell-derived xenograft models, Birinapant administration also reshaped the immunopeptidome, and the tumor exhibited better immunogenicity. These data suggest that Birinapant can reshape the tumor immunopeptidome with respect to quality and quantity, which improves the presentation of CTA peptides and neoantigens, thus enhancing the immunogenicity of tumor cells. Such changes may be vital to the effectiveness of combination therapy, which can be further transferred to the clinic or aid in the development of new immunotherapeutic strategies to improve the anti-tumor immune response.


Assuntos
Apresentação de Antígeno , Dipeptídeos , Indóis , Masculino , Animais , Humanos , Terapia Combinada , Modelos Animais de Doenças
6.
Int J Mol Sci ; 25(7)2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38612534

RESUMO

Early detection of diseases can increase the chances of successful treatment and survival. Therefore, it is necessary to develop a method for detecting or sensing biomolecules that cause trouble in living organisms. Disease sensors should possess specific properties, such as selectivity, reproducibility, stability, sensitivity, and morphology, for their routine application in medical diagnosis and treatment. This work focuses on biosensors in the form of surface-functionalized gold (AuNPs) and silver nanoparticles (AgNPs) prepared using a less-time-consuming, inexpensive, and efficient synthesis route. This allows for the production of highly pure and stable (non-aggregating without stabilizers) nanoparticles with a well-defined spherical shape, a desired diameter, and a monodisperse distribution in an aqueous environment, as confirmed by transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM-EDS), X-ray diffraction (XRD), photoelectron spectroscopy (XPS), ultraviolet-visible (UV-VIS) spectroscopy, and dynamic light scattering (DLS). Thus, these nanoparticles can be used routinely as biomarker sensors and drug-delivery platforms for precision medicine treatment. The NPs' surface was coated with phosphonate dipeptides of L-leucine (Leu; l-Leu-C(R1)(R2)PO3H2), and their adsorption was monitored using SERS. Reproducible spectra were analyzed to determine the orientation of the dipeptides (coating layers) on the nanoparticles' surface. The appropriate R2 side chain of the dipeptide can be selected to control the arrangement of these dipeptides. This allows for the proper formation of a layer covering the nanoparticles while also simultaneously interacting with the surrounding biological environment, such as cells, tissues, and biological fluids.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Adsorção , Ouro , Leucina , Reprodutibilidade dos Testes , Prata , Dipeptídeos
7.
Nutrients ; 16(7)2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38613052

RESUMO

Memory impairment is a serious problem with organismal aging and increased social pressure. The tetrapeptide Ala-Phe-Phe-Pro (AFFP) is a synthetic analogue of Antarctic krill derived from the memory-improving Antarctic krill peptide Ser-Ser-Asp-Ala-Phe-Phe-Pro-Phe-Arg (SSDAFFPFR) after digestion and absorption. The objective of this research was to assess the neuroprotective effects of AFFP by reducing oxidative stress and controlling lipid metabolism in the brains of mice with memory impairment caused by scopolamine. The 1H Nuclear magnetic resonance spectroscopy results showed that AFFP had three active hydrogen sites that could contribute to its antioxidant properties. The findings from in vivo tests demonstrated that AFFP greatly enhanced the mice's behavioral performance in the passive avoidance, novel object recognition, and eight-arm maze experiments. AFFP reduced oxidative stress by enhancing superoxide dismutase activity and malondialdehyde levels in mice serum, thereby decreasing reactive oxygen species level in the mice hippocampus. In addition, AFFP increased the unsaturated lipid content to balance the unsaturated lipid level against the neurotoxicity of the mice hippocampus. Our findings suggest that AFFP emerges as a potential dietary intervention for the prevention of memory impairment disorders.


Assuntos
Dipeptídeos , Euphausiacea , Animais , Camundongos , Metabolismo dos Lipídeos , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/prevenção & controle , Derivados da Escopolamina , Hipocampo , Lipídeos
8.
PLoS One ; 19(4): e0289239, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38625918

RESUMO

Dipeptidyl peptidase 4 (DP4)/CD26 regulates the biological function of various peptide hormones by releasing dipeptides from their N-terminus. The enzyme is a prominent target for the treatment of type-2 diabetes and various DP4 inhibitors have been developed in recent years, but their efficacy and side effects are still an issue. Many available crystal structures of the enzyme give a static picture about enzyme-ligand interactions, but the influence of amino acids in the active centre on binding and single catalysis steps can only be judged by mutagenesis studies. In order to elucidate their contribution to inhibitor binding and substrate catalysis, especially in discriminating the P1 amino acid of substrates, the amino acids R125, N710, E205 and E206 were investigated by mutagenesis studies. Our studies demonstrated, that N710 is essential for the catalysis of dipeptide substrates. We found that R125 is not important for dipeptide binding but interacts in the P1`position of the peptide backbone. In contrast to dipeptide substrates both amino acids play an essential role in the binding and arrangement of long natural substrates, particularly if lacking proline in the P1 position. Thus, it can be assumed that the amino acids R125 and N710 are important in the DP4 catalysed substrate hydrolysis by interacting with the peptide backbone of substrates up- and downstream of the cleavage site. Furthermore, we confirmed the important role of the amino acids E205 and E206. However, NP Y, displaying proline in P1 position, is still processed without the participation of E205 or E206.


Assuntos
Aminoácidos , Dipeptidil Peptidase 4 , Domínio Catalítico , Dipeptídeos/química , Dipeptidil Peptidase 4/química , Dipeptidil Peptidase 4/metabolismo , Peptídeos , Prolina/metabolismo , Serina Endopeptidases/metabolismo , Especificidade por Substrato , Humanos
9.
Theranostics ; 14(6): 2560-2572, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38646643

RESUMO

Management of prostate cancer (PC) might be improved by combining external beam radiotherapy (EBRT) and prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) with lutetium-177 (177Lu)-labeled PSMA inhibitors. We hypothesized a higher efficacy of the combination due to augmentation of the radiation dose to the tumor and interactions of EBRT with PSMA expression potentially increasing radiopharmaceutical uptake. Therefore, this study analyzed the influence of radiation on PSMA expression levels in vitro. The results were translated to evaluate the efficacy of the combination of photon EBRT and [177Lu]Lu-PSMA-617 in a murine PC xenograft model. Finally, a clinical case report on a combined elective field EBRT with RLT dose escalation illustrates a proof-of-concept. Methods: PSMA gene and protein expression were assessed in human PSMA-overexpressing LNCaP cells after irradiation using reverse transcription quantitative polymerase chain reaction (RT-qPCR), flow cytometry and On-Cell Western assays. In the in vivo therapy study, LNCaP tumor-bearing BALB/c nu/nu mice were irradiated once with 2 Gy X-ray EBRT and injected with 40 MBq [177Lu]Lu-PSMA-617 after 4 h or received single or no treatment (n = 10 each). Tumor-absorbed doses by [177Lu]Lu-PSMA-617 were calculated according to the Medical Internal Radiation Dosimetry (MIRD) formalism after deriving time-activity curves using a gamma probe. An exemplified patient case is demonstrated where fractionated EBRT (54 Gy to prostate; 45 Gy to pelvic lymphatics) and three cycles of [177Lu]Lu-PSMA-617 (3.4-6.0 GBq per cycle) were sequentially combined under concurrent androgen deprivation for treating locally advanced PC. Results: At 4 h following irradiation with 2-8 Gy, LNCaP cells displayed a PSMA protein upregulation by around 18% relative to non-irradiated cells, and a stronger upregulation on mRNA level (up to 2.6-fold). This effect was reversed by 24 h when PSMA protein levels were downregulated by up to 22%. Mice treated with the combination therapy showed significantly improved outcomes regarding tumor control and median survival (p < 0.0001) as compared to single or no treatment. Relative to monotherapy with PSMA-RLT or EBRT, the tumor doubling time was prolonged 1.7- or 2.7-fold and the median survival was extended by 24% or 60% with the combination, respectively. Additionally, tumors treated with EBRT exhibited a 14% higher uptake of the radiopharmaceutical as evident from the calculated tumor-absorbed dose, albeit with high variability in the data. Concerning the patient case, the tri-modality treatment was well tolerated and the patient responded with a long-lasting complete biochemical remission for five years following end of PSMA-RLT. The patient then developed a biochemical relapse with oligo-recurrent disease on follow-up imaging. Conclusion: The present preclinical and clinical data demonstrate that the combination of EBRT with dose escalation by PSMA-RLT improves tumor control and potentially prolongs survival. This may pave the way for further clinical investigations of this approach to explore the curative potential of the combination therapy.


Assuntos
Dipeptídeos , Compostos Heterocíclicos com 1 Anel , Lutécio , Antígeno Prostático Específico , Neoplasias da Próstata , Radioisótopos , Compostos Radiofarmacêuticos , Animais , Masculino , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/metabolismo , Humanos , Lutécio/uso terapêutico , Lutécio/farmacologia , Compostos Heterocíclicos com 1 Anel/uso terapêutico , Compostos Heterocíclicos com 1 Anel/farmacologia , Dipeptídeos/farmacologia , Dipeptídeos/uso terapêutico , Linhagem Celular Tumoral , Camundongos , Compostos Radiofarmacêuticos/uso terapêutico , Compostos Radiofarmacêuticos/farmacologia , Compostos Radiofarmacêuticos/farmacocinética , Radioisótopos/uso terapêutico , Radioisótopos/farmacologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Glutamato Carboxipeptidase II/metabolismo , Glutamato Carboxipeptidase II/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Antígenos de Superfície/metabolismo , Antígenos de Superfície/genética
10.
BMC Vet Res ; 20(1): 95, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38461255

RESUMO

BACKGROUND: We investigated breed and gender variations in the compositions of long-chain (≥ C20) omega-3 polyunsaturated fatty acids (LC omega-3 PUFA), fat melting point (FMP) and intramuscular fat (IMF) contents in biopsy samples of the M. longissimus dorsi muscle of grazing beef cattle. The hypothesis that biopsy compositions of health-beneficial LC omega-3 PUFA, FMP and IMF in a pasture-based production system will vary with breed, was tested. Muscle biopsies were taken from 127 yearling pasture-based Angus, Hereford, and Wagyu heifers and young bulls exclusive to the Australian Bowen Genetics Forest Pastoral breeding stud averaging 12 ± 2.43 months of age and under the same management routine. RESULTS: Breed had a significant influence on IMF, FMP, and the compositions of oleic acid, α-linolenic acid (ALA), eicosapentaenoic (EPA), docosahexaenoic (DHA), docosapentaenoic (DPA), and total EPA + DHA + DPA in the M. longissimus dorsi muscle biopsies (P ≤ 0.03). The Wagyu breed had the highest (11.1%) and Hereford the lowest (5.9%) IMF (P = 0.03). The reverse trend was observed in FMP values where the Hereford breed had the highest (55 °C), Angus intermediate (46.5 °C), and Wagyu the lowest (33 °C) FMP. The Wagyu and Angus breeds had similar oleic fatty acid (18:1n-9) content, while the Hereford breed had the lowest (P < 0.01). The highest ALA, DPA, total EPA + DHA, total EPA + DHA + DPA and total ALA + EPA + DHA + DPA contents were detected in the Wagyu breed (P ≤ 0.03). The Hereford had similar EPA and DPA contents to the Angus (P ≥ 0.46). Total EPA + DHA + DPA contents in Wagyu, Angus, and Hereford were 28.8, 21.5, and 22.1 mg/100g tissue (P = 0.01), respectively. Sex was an important source of variation that influenced LC omega-3 PUFA composition, FMP and IMF, where yearling heifers had higher IMF (11.9% vs 5.3%), lower FMP (33°C vs 37°C), and higher LC omega-3 PUFA than bulls. CONCLUSION: All the results taken together indicate that the Wagyu breed at 28.8 mg/100g tissue, was the closest to meeting the Australia and New Zealand recommended source level threshold of 30 mg/100g tissue of health-beneficial ≥ C20 omega-3 FA content. Since gender was a significant determinant of LC omega-3 PUFA composition, IMF content and FMP, it should be factored into enhancement strategies of healthy meat eating quality traits in grazing cattle. These findings also suggest that the Bowen Genetics Forest Pastoral beef cattle studs are important sources of LC omega-3 PUFA that can be used to cover the deficit in these health claimable fatty acids in Western diets.


Assuntos
Dipeptídeos , Ácidos Graxos Ômega-3 , Bovinos/genética , Animais , Masculino , Feminino , Austrália , Ácidos Graxos , Músculos
11.
Eur J Med Res ; 29(1): 169, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38475920

RESUMO

Myocardial Infarction (MI) is major cause of heart failure, highlighting the critical need for effective therapeutic strategies to improve cardiac repair. This study investigated the cardioprotective effects of VX765-coated polyethyleneimine (PEI)/sodium alginate (AG) composite nanogels (AG/PEI-VX765 NGs) in a rat model of MI. Additionally, AG-VX765 NGs and PEI-VX765 nanospheres (NPs) were synthesized and tested to compare their efficacy. MI was caused in rats by ligating the left anterior descending branch of the coronary artery, and the rats were grouped and set as Sham, MI, MI + VX765, MI + AG-VX765NGs, MI + PEI-VX765NPs, and MI + AG/PEI-VX765NGs. Results demonstrate that AG/PEI-VX765NGs were non-toxic and exhibited a sustained release of VX765. In vivo, experiments demonstrated that all treatment groups significantly enhanced cardiac function, reduced infarct size, fibrosis, and apoptosis in rats with MI, with the MI + AG/PEI-VX765NGs group exhibiting the most favorable outcomes. Our findings indicate that AG/PEI-VX765NGs represent a promising therapeutic approach for MI treatment.


Assuntos
Alginatos , Infarto do Miocárdio , para-Aminobenzoatos , Ratos , Animais , Nanogéis/uso terapêutico , Alginatos/uso terapêutico , Dipeptídeos/uso terapêutico
12.
Chem Pharm Bull (Tokyo) ; 72(3): 309-310, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38479891

RESUMO

The inhibition mode of a retro-inverso (RI) inhibitor containing a hydroxyethylamine dipeptide isostere against the human T-cell leukemia virus type-1 (HTLV-1) protease was examined. Enzymatic evaluation of the RI-modified inhibitor containing a D-allo-Ile residue revealed that HTLV-1 was competitively inhibited. IC50 values of the RI-modified inhibitor and pepstatin A, a standard inhibitor of aspartic proteases, were nearly equivalent.


Assuntos
Ácido Aspártico Endopeptidases , Vírus Linfotrópico T Tipo 1 Humano , Humanos , Sequência de Aminoácidos , Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/metabolismo , Vírus Linfotrópico T Tipo 1 Humano/metabolismo , Dipeptídeos , Inibidores de Proteases/farmacologia
13.
EBioMedicine ; 102: 105005, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38553262

RESUMO

BACKGROUND: Sweeteners and sweetness enhancers (S&SE) are used to replace energy yielding sugars and maintain sweet taste in a wide range of products, but controversy exists about their effects on appetite and endocrine responses in reduced or no added sugar solid foods. The aim of the current study was to evaluate the acute (1 day) and repeated (two-week daily) ingestive effects of 2 S&SE vs. sucrose formulations of biscuit with fruit filling on appetite and endocrine responses in adults with overweight and obesity. METHODS: In a randomised crossover trial, 53 healthy adults (33 female, 20 male) with overweight/obesity in England and France consumed biscuits with fruit filling containing 1) sucrose, or reformulated with either 2) Stevia Rebaudioside M (StRebM) or 3) Neotame daily during three, two-week intervention periods with a two-week washout. The primary outcome was composite appetite score defined as [desire to eat + hunger + (100 - fullness) + prospective consumption]/4. FINDINGS: Each formulation elicited a similar reduction in appetite sensations (3-h postprandial net iAUC). Postprandial insulin (2-h iAUC) was lower after Neotame (95% CI (0.093, 0.166); p < 0.001; d = -0.71) and StRebM (95% CI (0.133, 0.205); p < 0.001; d = -1.01) compared to sucrose, and glucose was lower after StRebM (95% CI (0.023, 0.171); p < 0.05; d = -0.39) but not after Neotame (95% CI (-0.007, 0.145); p = 0.074; d = -0.25) compared to sucrose. There were no differences between S&SE or sucrose formulations on ghrelin, glucagon-like peptide 1 or pancreatic polypeptide iAUCs. No clinically meaningful differences between acute vs. two-weeks of daily consumption were found. INTERPRETATION: In conclusion, biscuits reformulated to replace sugar using StRebM or Neotame showed no differences in appetite or endocrine responses, acutely or after a two-week exposure, but can reduce postprandial insulin and glucose response in adults with overweight or obesity. FUNDING: The present study was funded by the Horizon 2020 program: Sweeteners and sweetness enhancers: Impact on health, obesity, safety and sustainability (acronym: SWEET, grant no: 774293).


Assuntos
Apetite , Dipeptídeos , Diterpenos do Tipo Caurano , Stevia , Trissacarídeos , Adulto , Masculino , Humanos , Feminino , Sacarose/farmacologia , Sobrepeso/tratamento farmacológico , Paladar , Estudos Cross-Over , Estudos Prospectivos , Glicemia , Obesidade/tratamento farmacológico , Edulcorantes/farmacologia , Glucose , Insulina/farmacologia , Açúcares/farmacologia
14.
Plant Cell Rep ; 43(4): 92, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38466441

RESUMO

KEY MESSAGE: Pepper fruits contain two leucine aminopeptidase (LAP) genes which are differentially modulated during ripening and by nitric oxide. The LAP activity increases during ripening but is negatively modulated by nitration. Leucine aminopeptidase (LAP) is an essential metalloenzyme that cleaves N-terminal leucine residues from proteins but also metabolizes dipeptides and tripeptides. LAPs play a fundamental role in cell protein turnover and participate in physiological processes such as defense mechanisms against biotic and abiotic stresses, but little is known about their involvement in fruit physiology. This study aims to identify and characterize genes encoding LAP and evaluate their role during the ripening of pepper (Capsicum annuum L.) fruits and under a nitric oxide (NO)-enriched environment. Using a data-mining approach of the pepper plant genome and fruit transcriptome (RNA-seq), two LAP genes, designated CaLAP1 and CaLAP2, were identified. The time course expression analysis of these genes during different fruit ripening stages showed that whereas CaLAP1 decreased, CaLAP2 was upregulated. However, under an exogenous NO treatment of fruits, both genes were downregulated. On the contrary, it was shown that during fruit ripening LAP activity increased by 81%. An in vitro assay of the LAP activity in the presence of different modulating compounds including peroxynitrite (ONOO-), NO donors (S-nitrosoglutathione and nitrosocyteine), reducing agents such as reduced glutathione (GSH), L-cysteine (L-Cys), and cyanide triggered a differential response. Thus, peroxynitrite and reducing compounds provoked around 50% inhibition of the LAP activity in green immature fruits, whereas cyanide upregulated it 1.5 folds. To our knowledge, this is the first characterization of LAP in pepper fruits as well as of its regulation by diverse modulating compounds. Based on the capacity of LAP to metabolize dipeptides and tripeptides, it could be hypothesized that the LAP might be involved in the GSH recycling during the ripening process.


Assuntos
Capsicum , Óxido Nítrico , Óxido Nítrico/metabolismo , Frutas/metabolismo , Capsicum/genética , Capsicum/metabolismo , Leucina/metabolismo , Leucil Aminopeptidase/genética , Leucil Aminopeptidase/metabolismo , Ácido Peroxinitroso/metabolismo , Cianetos/metabolismo , Dipeptídeos/metabolismo
15.
Neurosci Lett ; 828: 137752, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38552868

RESUMO

BACKGROUND: Exercise training showed beneficial effects on brain. The purpose of the present study is to evaluate the effect of six weeks of high-intensity interval training (HIIT) and Endurance training (ET) with calcitonin gene-related peptide (CGRP) receptor antagonist on the expression of genes involved in mitochondrial dynamics and apoptosis in hippocampal tissue of male Wistar rats. METHODS: In this study, forty-two healthymale Wistar rats (8-week) were randomly divided into 6 groups (n = 7) as follow; 1) Control; 2) HIIT which performed 6 weeks of HIIT; 3) ET which performed 6 weeks of endurance training; 4) CGRPi received 10 mg/kg CGRP receptor antagonist every day at the last 2 weeks; 5) CGRPi-HIIT performed HIIT and received CGRP receptor antagonist; 6) CGRPi-ET performed ET and received CGRP receptor antagonist. Real-time PCR (2-ΔΔCT) and western blotting were employedto measure the expression of genes and protein, respectively. RESULTS: HIIT and ET significantly increased Bcl-2, Pgc-1α, Sirt3, and Nrf-1 gene expression in the hippocampal tissue (p < 0.05, p < 0.01, p < 0.01, and p < 0.001, respectively). ET-CGRPi and HIIT-CGRPi significantly increased Sirt3, Pgc-1α, and Nrf-1 gene expression compared to the control group (p < 0.05, p < 0.01, and p < 0.05, respectively). CONCLUSION: ET and HIIT-induced physiological alterations in the hippocampus. In fact, this modulation showed protective properties in the hippocampusvia up regulation of Bcl-2, Pgc-1α, Nrf-1, and Sirt3 gene expression. CGRPi did not cause gene or protein changes harmful to mitochondrial dynamic balance and apoptosis in the hippocampus of rats.


Assuntos
Dipeptídeos , Treinamento Intervalado de Alta Intensidade , Condicionamento Físico Animal , Quinazolinas , Sirtuína 3 , Ratos , Masculino , Animais , Ratos Wistar , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina/metabolismo , Dinâmica Mitocondrial , Sirtuína 3/metabolismo , Hipocampo/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Condicionamento Físico Animal/fisiologia
16.
Biomacromolecules ; 25(4): 2476-2485, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38551400

RESUMO

Dipeptides stereoisomers and regioisomers composed of norleucine (Nle) and phenylalanine (Phe) self-assemble into hydrogels under physiological conditions that are suitable for cell culture. The supramolecular behavior, however, differs as the packing modes comprise amphipathic layers or water channels, whose diameter is defined by either four or six dipeptide molecules. A variety of spectroscopy, microscopy, and synchrotron-radiation-based techniques unveil fine details of intermolecular interactions that pinpoint the relationship between the chemical structure and ability to form supramolecular architectures that define soft biomaterials.


Assuntos
Dipeptídeos , Hidrogéis , Dipeptídeos/química , Hidrogéis/química , Água/química , Estereoisomerismo , Microscopia
17.
J Agric Food Chem ; 72(13): 7121-7129, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38511275

RESUMO

The dipeptide Tyr-Pro has physiological potential for intact transportability into the brain parenchyma, prevention of cognitive impairment, and an adiponectin receptor 1 (AdipoR1) agonistic effect. The present study aimed to understand the effect of Tyr-Pro on the acetylcholine (ACh) nervous system and its underlying mechanism in NE-4C nerve cells. Concentration-dependent ACh production was induced by stimulation with Tyr-Pro and AdipoRon (an AdipoR1 agonist), along with the expression of AdipoR1 and choline acetyltransferase (ChAT) in NE-4C cells. By knocking down AdipoR1 in the cells, Tyr-Pro promoted ChAT expression, along with the activations of AMPK and ERK 1/2. Tyr-Pro did not alter acetylcholinesterase or ACh receptors, indicating that the dipeptide might operate as an ACh accelerator in nerve cells. This study provides the first evidence that the AdipoR1 agonistic Tyr-Pro is a promising dipeptide responsible for the stimulation of the ACh nervous system by AdipoR1-induced ChAT activation.


Assuntos
Acetilcolina , Acetilcolinesterase , Acetilcolina/farmacologia , Acetilcolina/metabolismo , Acetilcolinesterase/metabolismo , Adiponectina/metabolismo , Dipeptídeos/farmacologia , Dipeptídeos/metabolismo , Neurônios , Proteínas de Transporte
18.
Toxins (Basel) ; 16(3)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38535807

RESUMO

During an experiment where we were cultivating aflatoxigenic Aspergillus flavus on peanuts, we accidentally discovered that a bacterium adhering to the peanut strongly inhibited aflatoxin (AF) production by A. flavus. The bacterium, isolated and identified as Klebsiella aerogenes, was found to produce an AF production inhibitor. Cyclo(l-Ala-Gly), isolated from the bacterial culture supernatant, was the main active component. The aflatoxin production-inhibitory activity of cyclo(l-Ala-Gly) has not been reported. Cyclo(l-Ala-Gly) inhibited AF production in A. flavus without affecting its fungal growth in a liquid medium with stronger potency than cyclo(l-Ala-l-Pro). Cyclo(l-Ala-Gly) has the strongest AF production-inhibitory activity among known AF production-inhibitory diketopiperazines. Related compounds in which the methyl moiety in cyclo(l-Ala-Gly) is replaced by ethyl, propyl, or isopropyl have shown much stronger activity than cyclo(l-Ala-Gly). Cyclo(l-Ala-Gly) did not inhibit recombinant glutathione-S-transferase (GST) in A. flavus, unlike (l-Ala-l-Pro), which showed that the inhibition of GST was not responsible for the AF production-inhibition of cyclo(l-Ala-Gly). When A. flavus was cultured on peanuts dipped for a short period of time in a dilution series bacterial culture broth, AF production in the peanuts was strongly inhibited, even at a 1 × 104-fold dilution. This strong inhibitory activity suggests that the bacterium is a candidate for an effective biocontrol agent for AF control.


Assuntos
Aflatoxinas , Aspergillus flavus , Klebsiella , Dipeptídeos , Arachis , Glutationa Transferase
19.
Food Chem ; 446: 138870, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38430771

RESUMO

Mustard (Brassica spp.) is one of the world's oldest condiments in the food basket, which holds a significant place in the global culinary landscape due to historical prominence and perceived health benefits. This study explores the extraction of oils from Mustard seeds by employing traditional 'Kolhu' method, modern supercritical fluid, and solvent extraction techniques. This study, for the first-time, identified Aurantiamide acetate, a potent anti-cancer dipeptide in Mustard seeds using ultra-performance liquid chromatography-mass spectrometry coupled with quadrupole time-of-flight (UPLC/MS-QToF) analytical platform. The analytical methodology was meticulously validated encompassing optimal parameters such as limit of detection, limit of quantification, precision, accuracy, linearity and robustness, within the range. Interestingly, 'Kolhu' method of oil extraction exhibited better yield of Aurantiamide acetate, suggesting superior efficiency of traditional methods. This study accentuates the importance of classical extraction methods, used traditionally, and emphasizes that naturally occurring substances indeed could be harnessed for better health.


Assuntos
Mostardeira , Espectrometria de Massas em Tandem , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , 60705 , Dipeptídeos , Sementes
20.
J Nucl Med ; 65(4): 560-565, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38453363

RESUMO

In metastatic castration-resistant prostate cancer (mCRPC) patients treated with prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT), the recently proposed criteria for evaluating response to PSMA PET (RECIP 1.0) based on 68Ga- and 18F-labeled PET agents provided prognostic information in addition to changes in prostate-specific antigen (PSA) levels. Our aim was to evaluate the prognostic performance of this framework for overall survival (OS) in patients undergoing RLT and imaged with [18F]PSMA-1007 PET/CT and compare the prognostic performance with the PSA-based response assessment. Methods: In total, 73 patients with mCRPC who were scanned with [18F]PSMA-1007 PET/CT before and after 2 cycles of RLT were retrospectively analyzed. We calculated the changes in serum PSA levels (ΔPSA) and quantitative PET parameters for the whole-body tumor burden (SUVmean, SUVmax, PSMA tumor volume, and total lesion PSMA). Men were also classified following the Prostate Cancer Working Group 3 (PCWG3) criteria for ΔPSA and RECIP 1.0 for PET imaging response. We performed univariable Cox regression analysis, followed by multivariable and Kaplan-Meier analyses. Results: Median OS was 15 mo with a median follow-up time of 14 mo. Univariable Cox regression analysis provided significant associations with OS for ΔPSA (per percentage, hazard ratio [HR], 1.004; 95% CI, 1.002-1.007; P < 0.001) and PSMA tumor volume (per unit, HR, 1.003; 95% CI, 1.000-1.005; P = 0.03). Multivariable Cox regression analysis confirmed ΔPSA (per percentage, HR, 1.004; 95% CI, 1.001-1.006; P = 0.006) as an independent prognosticator for OS. Kaplan-Meier analyses provided significant segregation between individuals with versus those without any PSA response (19 mo vs. 14 mo; HR, 2.00; 95% CI, 0.95-4.18; P = 0.04). Differentiation between patients with or without progressive disease (PD) was also feasible when applying PSA-based PCWG3 (19 mo vs. 9 mo for non-PD and PD, respectively; HR, 2.29; 95% CI, 1.03-5.09; P = 0.01) but slightly failed when applying RECIP 1.0 (P = 0.08). A combination of both response systems (PCWG3 and RECIP 1.0), however, yielded the best discrimination between individuals without versus those with PD (19 mo vs. 8 mo; HR, 2.78; 95% CI, 1.32-5.86; P = 0.002). Conclusion: In patients with mCRPC treated with RLT and imaged with [18F]PSMA-1007, frameworks integrating both the biochemical (PCWG3) and PET-based response (RECIP 1.0) may best assist in identifying subjects prone to disease progression.


Assuntos
Niacinamida , Oligopeptídeos , Antígeno Prostático Específico , Neoplasias de Próstata Resistentes à Castração , Ureia , Humanos , Masculino , Dipeptídeos/efeitos adversos , Compostos Heterocíclicos com 1 Anel/efeitos adversos , Lutécio , Niacinamida/análogos & derivados , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Prognóstico , Neoplasias de Próstata Resistentes à Castração/diagnóstico por imagem , Neoplasias de Próstata Resistentes à Castração/radioterapia , Estudos Retrospectivos , Resultado do Tratamento , Ureia/análogos & derivados
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA