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1.
J Phys Chem B ; 128(14): 3350-3359, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38564809

RESUMO

Secondary coordination sphere (SCS) interactions have been shown to play important roles in tuning reduction potentials and electron transfer (ET) properties of the Type 1 copper proteins, but the precise roles of these interactions are not fully understood. In this work, we examined the influence of F114P, F114N, and N47S mutations in the SCS on the electronic structure of the T1 copper center in azurin (Az) by studying the hyperfine couplings of (i) histidine remote Nε nitrogens and (ii) the amide Np using the two-dimensional (2D) pulsed electron paramagnetic resonance (EPR) technique HYSCORE (hyperfine sublevel correlation) combined with quantum mechanics/molecular mechanics (QM/MM) and DLPNO-CCSD calculations. Our data show that some components of hyperfine tensor and isotropic coupling in N47SAz and F114PAz (but not F114NAz) deviate by up to ∼±20% from WTAz, indicating that these mutations significantly influence the spin density distribution between the CuII site and coordinating ligands. Furthermore, our calculations support the assignment of Np to the backbone amide of residue 47 (both in Asn and Ser variants). Since the spin density distributions play an important role in tuning the covalency of the Cu-Scys bond of Type 1 copper center that has been shown to be crucial in controlling the reduction potentials, this study provides additional insights into the electron spin factor in tuning the reduction potentials and ET properties.


Assuntos
Nativos do Alasca , Azurina , Azurina/genética , Azurina/química , Cobre/química , Nitrogênio/química , Mutação , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Amidas
2.
Sci Rep ; 14(1): 8291, 2024 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594566

RESUMO

Neonicotinoids (NEOs) have been designed to act selectively on insect nicotinic acetylcholine receptors (nAChRs). However, nAChRs are also expressed in vertebrate immune cells, so NEOs may interfere with the immune system in exposed non-target animals. The present study shows that NEOs: imidacloprid and thiacloprid, and their main metabolites: desnitro-imidacloprid and thiacloprid amide, at sub-micromolar concentrations ranging from 2.25 to 20 µM, affect the immune cells of fish. This was found both in primary cultures of leukocytes isolated from the carp head kidney and in the continuous adherent carp monocyte/macrophage cell line. Moreover, the results revealed that the studied pesticides and metabolites generate oxidative stress in carp immune cells and that this is one of the most important mechanisms of neonicotinoid immunotoxicity. Significant increases were observed in the formation of ROS and malondialdehyde (MDA). The antioxidant status alteration was linked with decrease in antioxidant enzyme activity: superoxide dismutase (SOD), catalase (CAT), and non-enzymatic antioxidant glutathione (GSH). Importantly, the metabolites: desnitro-imidacloprid and thiacloprid amide showed significantly higher cytotoxicity towards fish leukocytes than their parent compounds, imidacloprid and thiacloprid, which emphasizes the importance of including intermediate metabolites in toxicology studies.


Assuntos
Carpas , Inseticidas , Receptores Nicotínicos , Tiazinas , Animais , Inseticidas/toxicidade , Carpas/metabolismo , Antioxidantes/metabolismo , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Estresse Oxidativo , Receptores Nicotínicos/metabolismo , Leucócitos/metabolismo , Amidas
3.
Molecules ; 29(7)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38611871

RESUMO

Oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) are endogenous lipids that act as agonists of the peroxisome proliferator-activated receptor α (PPARα). Recently, an interest in the role of these lipids in malignant tumors has emerged. Nevertheless, the effects of OEA and PEA on human neuroblastoma cells are still not documented. Type I interferons (IFNs) are immunomodulatory cytokines endowed with antiviral and anti-proliferative actions and are used in the treatment of various pathologies such as different cancer forms (i.e., non-Hodgkin's lymphoma, melanoma, leukemia), hepatitis B, hepatitis C, multiple sclerosis, and many others. In this study, we investigated the effect of OEA and PEA on human neuroblastoma SH-SY5Y cells treated with IFNß. We focused on evaluating cell viability, cell proliferation, and cell signaling. Co-exposure to either OEA or PEA along with IFNß leads to increased apoptotic cell death marked by the cleavage of caspase 3 and poly-(ADP ribose) polymerase (PARP) alongside a decrease in survivin and IKBα levels. Moreover, we found that OEA and PEA did not affect IFNß signaling through the JAK-STAT pathway and the STAT1-inducible protein kinase R (PKR). OEA and PEA also increased the phosphorylation of p38 MAP kinase and programmed death-ligand 1 (PD-L1) expression both in full cell lysate and surface membranes. Furthermore, GW6471, a PPARα inhibitor, and the genetic silencing of the receptor were shown to lower PD-L1 and cleaved PARP levels. These results reveal the presence of a novel mechanism, independent of the IFNß-prompted pathway, by which OEA and PEA can directly impair cell survival, proliferation, and clonogenicity through modulating and potentiating the intrinsic apoptotic pathway in human SH-SY5Y cells.


Assuntos
Amidas , Endocanabinoides , Etanolaminas , Neuroblastoma , Ácidos Oleicos , Humanos , Neuroblastoma/tratamento farmacológico , Antígeno B7-H1 , Janus Quinases , PPAR alfa , Inibidores de Poli(ADP-Ribose) Polimerases , Fatores de Transcrição STAT , Transdução de Sinais , Apoptose , Ácidos Palmíticos/farmacologia
4.
Eur Radiol Exp ; 8(1): 41, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38584248

RESUMO

BACKGROUND: We investigated the value of three-dimensional amide proton transfer-weighted imaging (3D-APTWI) in the diagnosis of early-stage breast cancer (BC) and its correlation with the immunohistochemical characteristics of malignant lesions. METHODS: Seventy-eight women underwent APTWI and dynamic contrast-enhanced (DCE)-MRI. Pathological results were categorized as either benign (n = 43) or malignant (n = 37) lesions. The parameters of APTWI and DCE-MRI were compared between the benign and malignant groups. The diagnostic value of 3D-APTWI was evaluated using the area under the receiver operating characteristic curve (ROC-AUC) to establish a diagnostic threshold. Pearson's correlation was used to analyze the correlation between the magnetization transfer asymmetry (MTRasym) and immunohistochemical characteristics. RESULTS: The MTRasym and time-to-peak of malignancies were significantly lower than those of benign lesions (all p < 0.010). The volume transfer constant, rate constant, and wash-in and wash-out rates of malignancies were all significantly greater than those of benign lesions (all p < 0.010). ROC-AUCs of 3D-APTWI, DCE-MRI, and 3D-APTWI+DCE to differential diagnosis between early-stage BC and benign lesions were 0.816, 0.745, and 0.858, respectively. Only the difference between AUCAPT+DCE and AUCDCE was significant (p < 0.010). When a threshold of MTRasym for malignancy for 2.42%, the sensitivity and specificity of 3D-APTWI for BC diagnosis were 86.5% and 67.6%, respectively; MTRasym was modestly positively correlated with pathological grade (r = 0.476, p = 0.003) and Ki-67 (r = 0.419, p = 0.020). CONCLUSIONS: 3D-APTWI may be used as a supplementary method for patients with contraindications of DCE-MRI. MTRasym can imply the proliferation activities of early-stage BC. RELEVANCE STATEMENT: 3D-APTWI can be an alternative diagnostic method for patients with early-stage BC who are not suitable for contrast injection. KEY POINTS: • 3D-APTWI reflects the changes in the microenvironment of early-stage breast cancer. • Combined 3D-APTWI is superior to DCE-MRI alone for early-stage breast cancer diagnosis. • 3D-APTWI improves the diagnostic accuracy of early-stage breast cancer.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/diagnóstico por imagem , Prótons , Amidas , Estudos Prospectivos , Imageamento por Ressonância Magnética/métodos , Microambiente Tumoral
5.
BMC Pregnancy Childbirth ; 24(1): 254, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589777

RESUMO

BACKGROUND: Epidural test dose for labor analgesia is controversial and varies widely in clinical practice. It is currently unclear whether using a portion of the initial dose for analgesia as the test dose delays the onset time of analgesia, compared to the traditional test dose. METHODS: One hundred and twenty-six parturients who chose epidural analgesia during labor were randomly assigned to two groups. The first dose in group L was 3 ml 1.5% lidocaine, and in the RF group was 10 ml 0.1% ropivacaine combined with 2 µg/ml fentanyl. After 3 min of observation, both groups received 8 ml 0.1% ropivacaine combined with 2 µg/ml fentanyl. The onset time of analgesia, motor and sensory blockade level, numerical pain rating scale, patient satisfaction score, and side effects were recorded. RESULTS: The onset time of analgesia in group RF was similar to that in group L (group RF vs group L, 7.0 [5.0-9.0] minutes vs 8.0 [5.0-11.0] minutes, p = 0.197). The incidence of foot numbness (group RF vs group L, 34.9% vs 57.1%, p = 0.020) and foot warming (group RF vs group L, 15.9% vs 47.6%, p < 0.001) in group RF was significantly lower than that in group L. There was no difference between the two groups on other outcomes. CONCLUSIONS: Compared with 1.5% lidocaine 3 ml, 0.1% ropivacaine 10 ml combined with 2 µg/ml fentanyl as an epidural test dose did not delay the onset of labor analgesia, and the side effects were slightly reduced. CLINICAL TRIAL REGISTRATION: http://www.chictr.org.cn (ChiCTR2100043071).


Assuntos
Analgesia Epidural , Analgesia Obstétrica , Feminino , Humanos , Ropivacaina , Anestésicos Locais/efeitos adversos , Amidas/efeitos adversos , Analgesia Obstétrica/efeitos adversos , Analgésicos , Fentanila/efeitos adversos , Lidocaína , Analgesia Epidural/efeitos adversos , Método Duplo-Cego
6.
Pestic Biochem Physiol ; 200: 105843, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38582603

RESUMO

Isoxazoline is a novel structure with strong potential for controlling agricultural insect pests, but its high toxicity to honeybees limits its development in agriculture. Herein, a series of N-phenylamide isoxazoline derivatives with low honeybee toxicity were designed and synthesized using the intermediate derivatization method. Bioassay results showed that these compounds exhibited good insecticidal activity. Compounds 3b and 3f showed significant insecticidal effects against Plutella xylostella (P. xylostella) with median lethal concentrations (LC50) of 0.06 and 0.07 mg/L, respectively, comparable to that of fluralaner (LC50 = 0.02 mg/L) and exceeding that of commercial insecticide fluxametamide (LC50 = 0.52 mg/L). It is noteworthy that the acute honeybee toxicities of compounds 3b and 3f (LD50 = 1.43 and 1.63 µg/adult, respectively) were significantly reduced to 1/10 of that of fluralaner (LD50 = 0.14 µg/adult), and were adequate or lower than that of fluxametamide (LD50 = 1.14 µg/adult). Theoretical simulation using molecular docking indicates that compound 3b has similar binding modes with fluralaner and a similar optimal docking pose with fluxametamide when binding to the GABA receptor, which may contribute to its potent insecticidal activity and relatively low toxicity to honey bees. This study provides compounds 3b and 3f as potential new insecticide candidates and provides insights into the development of new isoxazoline insecticides exhibiting both high efficacy and environmental safety.


Assuntos
Inseticidas , Mariposas , Abelhas , Animais , Inseticidas/toxicidade , Inseticidas/química , Simulação de Acoplamento Molecular , Insetos , Receptores de GABA/metabolismo , Amidas/toxicidade , Mariposas/metabolismo
7.
Public Health ; 230: 198-206, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38574425

RESUMO

OBJECTIVES: Long COVID is characterized by persistent symptoms lasting for 4 weeks or more following the acute infection with SARS-CoV-2. Risk factors for long COVID and the impact of pre-COVID vaccination and treatment during acute COVID-19 remain uncertain. This study aimed to investigate patient-specific factors associated with long COVID in a large cohort of non-hospitalized adult patients with mild to moderate COVID-19 in Dubai. STUDY DESIGN: Cohort study. METHODS: The study included 28,375 non-hospitalized adult patients diagnosed with mild to moderate COVID-19 between January 1, 2021, and September 31, 2022, in Dubai, who were followed up for 90 days. The presence of long COVID symptoms was documented by physicians during patient visits to the family medicine department. Furthermore, long COVID-related risk factors were collected and analyzed, including patient demographics, comorbidities, pre-COVID vaccination status, and the COVID-related treatments received during the acute phase of the illness. Cox proportional hazard models were applied for the statistical analysis. RESULTS: Among the cohort, 2.8% of patients experienced long COVID symptoms during the 90-day follow-up. Patients with long COVID tended to be younger, female, and of Caucasian race. Common symptoms included fatigue, muscle pain, respiratory symptoms, abdominal and neurological symptoms, allergic reactions, skin rashes, and hair loss. Risk factors for long COVID were identified as diabetes mellitus, asthma, and Vitamin D deficiency. Females and Caucasians had a higher risk of long COVID during the pre-Omicron period compared to the Omicron period. Pre-COVID vaccination was associated with a reduced risk of long COVID in all patient subgroups. Treatment with favipiravir or sotrovimab during the acute phase of COVID-19 was linked to a decreased risk of long COVID, although favipiravir showed limited effectiveness in the high-risk group. CONCLUSION: This study contributes to the existing knowledge by identifying risk factors for long COVID among non-hospitalized patients and emphasizing the potential benefits of pre-COVID vaccination and timely treatment.


Assuntos
Amidas , COVID-19 , Síndrome Pós-COVID-19 Aguda , Pirazinas , Adulto , Humanos , Feminino , COVID-19/epidemiologia , COVID-19/prevenção & controle , Emirados Árabes Unidos/epidemiologia , SARS-CoV-2 , Estudos de Coortes , Fatores de Risco
8.
J Pineal Res ; 76(2): e12941, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38606814

RESUMO

The labeled ligand commonly employed in competition binding studies for melatonin receptor ligands, 2-[125I]iodomelatonin, showed slow dissociation with different half-lives at the two receptor subtypes. This may affect the operational measures of affinity constants, which at short incubation times could not be obtained in equilibrium conditions, and structure-activity relationships, as the Ki values of tested ligands could depend on either interaction at the binding site or the dissociation path. To address these issues, the kinetic and saturation binding parameters of 2-[125I]iodomelatonin as well as the competition constants for a series of representative ligands were measured at a short (2 h) and a long (20 h) incubation time. Concurrently, we simulated by molecular modeling the dissociation path of 2-iodomelatonin from MT1 and MT2 receptors and investigated the role of interactions at the binding site on the stereoselectivity observed for the enantiomers of the subtype-selective ligand UCM1014. We found that equilibrium conditions for 2-[125I]iodomelatonin binding can be reached only with long incubation times, particularly for the MT2 receptor subtype, for which a time of 20 h approximates this condition. On the other hand, measured Ki values for a set of ligands including agonists, antagonists, nonselective, and subtype-selective compounds were not significantly affected by the length of incubation, suggesting that structure-activity relationships based on data collected at shorter time reflect different interactions at the binding site. Molecular modeling simulations evidenced that the slower dissociation of 2-iodomelatonin from the MT2 receptor can be related to the restricted mobility of a gatekeeper tyrosine along a lipophilic path from the binding site to the membrane bilayer. The enantiomers of the potent, MT2-selective agonist UCM1014 were separately synthesized and tested. Molecular dynamics simulations of the receptor-ligand complexes provided an explanation for their stereoselectivity as due to the preference shown by the eutomer at the binding site for the most abundant axial conformation adopted by the ligand in solution. These results suggest that, despite the slow-binding kinetics occurring for the labeled ligand, affinity measures at shorter incubation times give robust results consistent with known structure-activity relationships and with interactions taken at the receptor binding site.


Assuntos
Melatonina , Quinolinas , Ligantes , Receptores de Melatonina , Melatonina/metabolismo , Amidas , Receptor MT2 de Melatonina/metabolismo , Receptor MT1 de Melatonina/metabolismo
9.
Cells ; 13(7)2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38607071

RESUMO

Adjuvant treatment for Glioblastoma Grade 4 with Temozolomide (TMZ) inevitably fails due to therapeutic resistance, necessitating new approaches. Apoptosis induction in GB cells is inefficient, due to an excess of anti-apoptotic XPO1/Bcl-2-family proteins. We assessed TMZ, Methotrexate (MTX), and Cytarabine (Ara-C) (apoptosis inducers) combined with XPO1/Bcl-2/Mcl-1-inhibitors (apoptosis rescue) in GB cell lines and primary GB stem-like cells (GSCs). Using CellTiter-Glo® and Caspase-3 activity assays, we generated dose-response curves and analyzed the gene and protein regulation of anti-apoptotic proteins via PCR and Western blots. Optimal drug combinations were examined for their impact on the cell cycle and apoptosis induction via FACS analysis, paralleled by the assessment of potential toxicity in healthy mouse brain slices. Ara-C and MTX proved to be 150- to 10,000-fold more potent in inducing apoptosis than TMZ. In response to inhibitors Eltanexor (XPO1; E), Venetoclax (Bcl-2; V), and A1210477 (Mcl-1; A), genes encoding for the corresponding proteins were upregulated in a compensatory manner. TMZ, MTX, and Ara-C combined with E, V, and A evidenced highly lethal effects when combined. As no significant cell death induction in mouse brain slices was observed, we conclude that this drug combination is effective in vitro and expected to have low side effects in vivo.


Assuntos
Amidas , Antineoplásicos , Compostos Bicíclicos Heterocíclicos com Pontes , Glioblastoma , Pirimidinas , Sulfonamidas , Animais , Camundongos , Temozolomida/farmacologia , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Metotrexato/farmacologia , Metotrexato/uso terapêutico , Citarabina/farmacologia , Citarabina/uso terapêutico , Antineoplásicos Alquilantes/farmacologia , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Apoptose
10.
J Infect Public Health ; 17(5): 897-905, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38569269

RESUMO

BACKGROUND: The efficacy of the viral clearance and clinical outcomes of favipiravir (FPV) in outpatients being treated for coronavirus disease 2019 (COVID-19) is unclear. Ivermectin (IVM), niclosamide (NCL), and FPV demonstrated synergistic effects in vitro for exceed 78% inhibiting severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) replication. METHODS: A phase 2, open-label, 1:1, randomized, controlled trial was conducted on Thai patients with mild-to-moderate COVID-19 who received either combination FPV/IVM/NCL therapy or FPV alone to assess the rate of viral clearance among individuals with mild-to-moderate COVID-19. RESULTS: Sixty non-high-risk comorbid patients with mild-to-moderate COVID-19 were randomized; 30 received FPV/IVM/NCL, and 30 received FPV alone. Mixed-effects multiple linear regression analysis of the cycle threshold value from SARS-CoV-2 PCR demonstrated no statistically significant differences in viral clearance rates between the combined FPV/IVM/NCL therapy group and the FPV-alone group. World Health Organization Clinical Progression scores and symptomatic improvement did not differ between arms on days 3, 6, and 10, and no adverse events were reported. No patients required hospitalization, intensive care unit admission, or supplemental oxygen or died within 28 days. C-reactive protein on day 3 was lower in the FPV/IVM/NCL group. CONCLUSION: Viral clearance rates did not differ significantly between the FPV/IVM/NCL combination therapy and FPV-alone groups of individuals with mild-to-moderate COVID-19, although the combined regimen demonstrated a synergistic effect in vitro. No discernible clinical benefit was observed. Further research is required to explore the potential benefits of FVP beyond its antiviral effects. TRIAL REGISTRATION: TCTR20230403007, Registered 3 April 2023 - Retrospectively registered,https://trialsearch.who.int/Trial2.aspx?TrialID=TCTR20230403007.


Assuntos
Amidas , COVID-19 , Pirazinas , Adulto , Humanos , SARS-CoV-2 , Ivermectina/uso terapêutico , Niclosamida , Aceleração , Resultado do Tratamento , Antivirais/efeitos adversos
11.
Int J Mol Sci ; 25(7)2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38612735

RESUMO

The antitumor activity of different ent-kaurane diterpenes has been extensively studied. Several investigations have demonstrated the excellent antitumor activity of synthetic derivatives of the diterpene atractyligenin. In this research, a series of new synthetic amides and their 15,19-di-oxo analogues obtained from atractyligenin by modifying the C-2, C-15, and C-19 positions were designed in order to dispose of a set of derivatives with different substitutions at the amidic nitrogen. Using different concentrations of the obtained compounds (10-300 µM) a reduction in cell viability of HCT116 colon cancer cells was observed at 48 h of treatment. All the di-oxidized compounds were more effective than their alcoholic precursors. The di-oxidized compounds had already reduced the viability of two colon cancer cells (HCT116 and Caco-2) at 24 h when used at low doses (2.5-15 µM), while they turned out to be poorly effective in differentiated Caco-2 cells, a model of polarized enterocytes. The data reported here provide evidence that di-oxidized compounds induced apoptotic cell death, as demonstrated by the appearance of condensed and fragmented DNA in treated cells, as well as the activation of caspase-3 and fragmentation of its target PARP-1.


Assuntos
Atractilosídeo/análogos & derivados , Neoplasias do Colo , Diterpenos do Tipo Caurano , Humanos , Diterpenos do Tipo Caurano/farmacologia , Células CACO-2 , Neoplasias do Colo/tratamento farmacológico , Amidas , Apoptose
12.
Front Endocrinol (Lausanne) ; 15: 1287930, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38577572

RESUMO

Objective: To evaluate the role of foot muscle amide proton transfer weighted (APTw) contrast and tissue rest perfusion in quantifying diabetic foot (DF) infection and its correlation with blood parameters. Materials and methods: With approval from an ethical review board, this study included 40 diabetes mellitus (DM) patients with DF and 31 DM patients without DF or other lower extremity arterial disease. All subjects underwent MRI, which included foot sagittal APTw and coronal arterial spin labeling (ASL) imaging. The normalized MTRasym (3.5 ppm) and the ratio of blood flow (rBF) in rest status of the affected side lesions to the non-affected contralateral side were determined. The inter-group differences of these variables were evaluated. Furthermore, the association between normalized MTRasym (3.5 ppm), rBF, and blood parameters [fasting blood glucose (FBG), glycosylated hemoglobin content, C-reactive protein, neutrophil percentage, and white blood cell count] was explored. Using an ROC curve, the diagnostic capacity of normalized MTRasym (3.5 ppm), BF, and blood biochemical markers in differentiating with or without DF in DM was assessed. Results: In the DF group, MTRasym (3.5 ppm) and BF in lesion and normalized MTRasym (3.5 ppm) were higher than those in the control group (p < 0.05). In addition, correlations were identified between normalized MTRasym (3.5 ppm) and blood parameters, such as C-reactive protein, glycosylated hemoglobin content, FBG, neutrophil ratio, and white blood cell (p < 0.001). Meanwhile, association between BF in lesion and blood parameters, such as C-reactive protein, neutrophil percentage, and FBG (p < 0.01). AUC of normalized MTRasym (3.5 ppm) in identifying with/without DF in patients with DM is 0.986 (95% CI, 0.918-1.00) with the sensitivity of 97.22% and the specificity of 100%. Conclusion: Normalized MTRasym (3.5 ppm) and the BF in lesion may be treated as a safer and more convenient new indicator to evaluate the tissue infection without using a contrast agent, which may be useful in monitoring and preoperatively assessing DF patients with renal insufficiency.


Assuntos
Diabetes Mellitus , Pé Diabético , Humanos , Prótons , Pé Diabético/diagnóstico por imagem , Amidas/química , Proteína C-Reativa , Estudos de Casos e Controles , Hemoglobinas Glicadas , Imageamento por Ressonância Magnética/métodos
13.
Mol Biol Rep ; 51(1): 482, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38578512

RESUMO

BACKGROUND: Natural bone grafts are the highly preferred materials for restoring the lost bone, while being constrained of donor availability and risk of disease transmission. As a result, tissue engineering is emerging as an efficacious and competitive technique for bone repair. Bone tissue engineering (TE) scaffolds to support bone regeneration and devoid of aforesaid limitations are being vastly explored and among these the avian eggshell membrane has drawn attention for TE owing to its low immunogenicity, similarity with the extracellular matrix, and easy availability. METHODOLOGY AND RESULTS: In this study, the development of bone ingrowth support system from avian eggshell membrane derived collagen hydrolysates (Col-h) is reported. The hydrolysate, cross-linked with glutaraldehyde, was developed into hydrogels with poly-(vinyl alcohol) (PVA) by freeze-thawing and further characterized with ATR-FTIR, XRD, FESEM. The biodegradability, swelling, mechanical, anti-microbial, and biocompatibility evaluation were performed further for the suitability in bone regeneration. The presence of amide I, amide III, and -OH functional groups at 1639 cm- 1,1264 cm- 1, and 3308 cm- 1 respectively and broad peak between 16°-21° (2θ) in XRD data reinstated the composition and form. CONCLUSIONS: The maximum ratio of Col-h/PVA that produced well defined hydrogels was 50:50. Though all the hydrogel matrices alluded towards their competitive attributes and applicability towards restorative bone repair, the hydrogel with 40:60 ratios showed better mechanical strength and cell proliferation than its counterparts. The prominent E. coli growth inhibition by the hydrogel matrices was also observed, along with excellent biocompatibility with MG-63 osteoblasts. The findings indicate strongly the promising application of avian eggshell-derived Col-h in supporting bone regeneration.


Assuntos
Casca de Ovo , Escherichia coli , Animais , Colágeno/farmacologia , Tecidos Suporte , Engenharia Tecidual/métodos , Hidrogéis , Regeneração Óssea , Amidas
14.
Biomacromolecules ; 25(4): 2531-2541, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38508219

RESUMO

Peptide amphiphiles (PAs) are highly tunable molecules that were recently found to exhibit aggregation-induced emission (AIE) when they self-assemble into nanofibers. Here, we leverage decades of molecular design and self-assembly study of PAs to strategically tune their molecular motion within nanofibers to enhance AIE, making them a highly useful platform for applications such as sensing, bioimaging, or materials property characterization. Since AIE increases when aggregated molecules are rigidly and closely packed, we altered the four most closely packed amino acids nearest to the hydrophobic core by varying the order and composition of glycine, alanine, and valine pairs. Of the six PA designs studied, C16VVAAK2 had the highest quantum yield at 0.17, which is a more than 10-fold increase from other PA designs including the very similar C16AAVVK2, highlighting the importance of precise amino acid placement to anchor rigidity closest to the core. We also altered temperature to increase AIE. C16VVAAK2 exhibited an additional 4-fold increase in maximum fluorescence intensity when the temperature was raised from 5 to 65 °C. As the temperature increased, the secondary structure transitioned from ß-sheet to random coil, indicating that further packing an already aligned molecular system makes it even more readily able to transfer energy between the electron-rich amides. This work both unveils a highly fluorescent AIE PA system design and sheds insights into the molecular orientation and packing design traits that can significantly enhance AIE in self-assembling systems.


Assuntos
Nanofibras , Nanofibras/química , Fluorescência , Peptídeos/química , Estrutura Secundária de Proteína , Amidas
15.
Int J Biol Macromol ; 264(Pt 2): 130574, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38453125

RESUMO

The prevalent use of disposable plastic tableware presents notable environmental and health risks. An alternative, polylactic acid (PLA), often does not meet usage requirements due to its low crystallization rate. This research introduces an amide-based nucleating agent, BRE-T-100, developed through a straightforward method to enhance the heat resistance and crystallization rate of PLA. This study systematically investigates the impact of BRE-T-100 and other nucleating agents on the properties of PLA composites. The incorporation of 0.8 % BRE-T-100 increases the crystallization temperature of PLA from 109.6 °C to 131.9 °C. Further, the total crystallization time of PLA composites at 120 °C is reduced to <60 s, while maintaining good transparency. BRE-T-100 exhibits superior comprehensive properties compared to talcum, TMC-200, and TMC-300 and is nearly on par with LAK-301. Its application as a nucleating agent in PLA-based disposable tableware shows promise.


Assuntos
Amidas , Temperatura Alta , Poliésteres/química , Temperatura
16.
Int Immunopharmacol ; 131: 111774, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38489971

RESUMO

Corona Virus Disease 2019 (COVID-19) is an infectious disease that seriously endangers human life and health. The pathological anatomy results of patients who died of the COVID-19 showed that there was an excessive inflammatory response in the lungs. It is also known that most of the COVID-19 infected patients will cause different degrees of lung damage after infection, and may have pulmonary fibrosis remaining after cure. Macrophages are a type of immune cell population with pluripotency and plasticity. In the early and late stages of infection, the dynamic changes of the balance and function of M1/M2 alveolar macrophages have a significant impact on the inflammatory response of the lungs. In the early stage of pulmonary fibrosis inflammation, the increase in the proportion of M1 type is beneficial to clear pathogenic microorganisms and promote the progress of inflammation; in the later stage of fibrosis, the increase in the number of M2 type macrophages can inhibit the inflammatory response and promote the degradation of fibrosis. As a potential treatment drug for new coronavirus pneumonia, favipiravir is in the process of continuously carried out relevant clinical trials. This study aims to discuss whether the antiviral drug favipiravir can suppress inflammation and immune response by regulating the M1/M2 type of macrophages, thereby alleviating fibrosis. We established a bleomycin-induced pulmonary fibrosis model, using IL-4/13 and LPS/IFN-γ cell stimulating factor to induce macrophage M1 and M2 polarization models, respectively. Our study shows that favipiravir exerts anti-fibrotic effects mainly by reprogramming M1/M2 macrophages polarization, that is, enhancing the expression of anti-fibrotic M1 type, reducing the expression of M2 type pro-fibrotic factors and reprogramming it to anti-fibrotic phenotype. Aspects of pharmacological mechanisms, favipiravir inhibits the activation of JAK2-STAT6 and JAK2-PI3K-AKT signaling by targeting JAK2 protein, thereby inhibiting pro-fibrotic M2 macrophages polarization and M2-induced myofibroblast activation. In summary, favipiravir can reduce the progression of pulmonary fibrosis, we hope to provide a certain reference for the treatment of pulmonary fibrosis.


Assuntos
Amidas , COVID-19 , Pneumonia , Fibrose Pulmonar , Pirazinas , Humanos , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/metabolismo , Bleomicina/efeitos adversos , Fosfatidilinositol 3-Quinases/metabolismo , Macrófagos , Inflamação/metabolismo , Fibrose , Pneumonia/metabolismo , COVID-19/metabolismo
17.
Cancer Imaging ; 24(1): 33, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38439101

RESUMO

OBJECTIVES: To differentiate benign and malignant solitary pulmonary lesions (SPLs) by amide proton transfer-weighted imaging (APTWI), mono-exponential model DWI (MEM-DWI), stretched exponential model DWI (SEM-DWI), and 18F-FDG PET-derived parameters. METHODS: A total of 120 SPLs patients underwent chest 18F-FDG PET/MRI were enrolled, including 84 in the training set (28 benign and 56 malignant) and 36 in the test set (13 benign and 23 malignant). MTRasym(3.5 ppm), ADC, DDC, α, SUVmax, MTV, and TLG were compared. The area under receiver-operator characteristic curve (AUC) was used to assess diagnostic efficacy. The Logistic regression analysis was used to identify independent predictors and establish prediction model. RESULTS: SUVmax, MTV, TLG, α, and MTRasym(3.5 ppm) values were significantly lower and ADC, DDC values were significantly higher in benign SPLs than malignant SPLs (all P < 0.01). SUVmax, ADC, and MTRasym(3.5 ppm) were independent predictors. Within the training set, the prediction model based on these independent predictors demonstrated optimal diagnostic efficacy (AUC, 0.976; sensitivity, 94.64%; specificity, 92.86%), surpassing any single parameter with statistical significance. Similarly, within the test set, the prediction model exhibited optimal diagnostic efficacy. The calibration curves and DCA revealed that the prediction model not only had good consistency but was also able to provide a significant benefit to the related patients, both in the training and test sets. CONCLUSION: The SUVmax, ADC, and MTRasym(3.5 ppm) were independent predictors for differentiation of benign and malignant SPLs, and the prediction model based on them had an optimal diagnostic efficacy.


Assuntos
Fluordesoxiglucose F18 , Prótons , Humanos , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Amidas
18.
Pestic Biochem Physiol ; 199: 105757, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38458660

RESUMO

Fenhexamid are fungicides that act against plant pathogens by inhibiting sterol biosynthesis. Nonetheless, it can trigger endocrine disruption and promote breast cancer cell growth. In a recent study, we investigated the mechanism underlying the lipid accumulation induced by fenhexamid hydroxyanilide fungicides in 3 T3-L1 adipocytes. To examine the estrogen receptor alpha (ERα)-agonistic effect, ER transactivation assay using the ERα-HeLa-9903 cell line was applied, and fenhexamid-induced ERα agonist effect was confirmed. Further confirmation that ERα-dependent lipid accumulation occurred was provided by treating 3 T3-L1 adipocytes with Methyl-piperidino-pyrazole hydrate (MPP), an ERα-selective antagonist. Fenhexamid mimicked the actions of ERα agonists and impacted lipid metabolism, and its mechanism involves upregulation of the expression of transcription factors that facilitate adipogenesis and lipogenesis. Additionally, it stimulated the expression of peroxisome proliferator-activated receptor (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), fatty acid synthase (FAS), and sterol regulatory element-binding protein 1 (SREBP1) and significantly elevated the expression of fatty acid-binding protein 4 (FABP4). In contrast, in combination with an ERα-selective antagonist, fenhexamid suppressed the expression of adipogenic/lipogenic transcription factors. These results suggest that fenhexamid affects the endocrine system and leads to lipid accumulation by interfering with processes influenced by ERα activation.


Assuntos
Amidas , Receptor alfa de Estrogênio , Fungicidas Industriais , Camundongos , Animais , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Fungicidas Industriais/toxicidade , Fungicidas Industriais/metabolismo , Adipócitos/metabolismo , Adipogenia , Metabolismo dos Lipídeos , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/farmacologia , Lipídeos , Células 3T3-L1 , PPAR gama/metabolismo
19.
MAbs ; 16(1): 2333436, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38546837

RESUMO

Asparagine (Asn) deamidation and aspartic acid (Asp) isomerization are common degradation pathways that affect the stability of therapeutic antibodies. These modifications can pose a significant challenge in the development of biopharmaceuticals. As such, the early engineering and selection of chemically stable monoclonal antibodies (mAbs) can substantially mitigate the risk of subsequent failure. In this study, we introduce a novel in silico approach for predicting deamidation and isomerization sites in therapeutic antibodies by analyzing the structural environment surrounding asparagine and aspartate residues. The resulting quantitative structure-activity relationship (QSAR) model was trained using previously published forced degradation data from 57 clinical-stage mAbs. The predictive accuracy of the model was evaluated for four different states of the protein structure: (1) static homology models, (2) enhancing low-frequency vibrational modes during short molecular dynamics (MD) runs, (3) a combination of (2) with a protonation state reassignment, and (4) conventional full-atomistic MD simulations. The most effective QSAR model considered the accessible surface area (ASA) of the residue, the pKa value of the backbone amide, and the root mean square deviations of both the alpha carbon and the side chain. The accuracy was further enhanced by incorporating the QSAR model into a decision tree, which also includes empirical information about the sequential successor and the position in the protein. The resulting model has been implemented as a plugin named "Forecasting Reactivity of Isomerization and Deamidation in Antibodies" in MOE software, completed with a user-friendly graphical interface to facilitate its use.


Assuntos
Anticorpos Monoclonais , Asparagina , Isomerismo , Asparagina/química , Anticorpos Monoclonais/química , Amidas/química , Software
20.
Opt Express ; 32(4): 5287-5300, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38439260

RESUMO

Misfolding of amyloid protein will cause neurodegeneration and trigger conformational disease. The lack of an effective detection approach is a brake on unveiling the mechanism of protein misfolding. We theoretically proposed a novel metasurface-based biosensor for characterizing the protein's conformation. The coupling complementary split ring resonator (cSRR) was engineered to manipulate incident waves in the near-infrared (NIR) and mid-infrared (MIR) windows at the same sensing surface. The cSRRs had the advantages of intensifying the electric field and sharpening the resonance profile, resulting in a highly qualified biosensing performance. In the NIR window, the biolayer's refractive index and thickness change were detected by the dual-wavelength, which resolved into an optogeometrical parameter of the amyloid biolayer. In the MIR window, the resonant wave specifically triggered the rotation-vibration transition of amyloid protein molecules with different conformations, which was shown as the unique Amide I and II bands in the fingerprint spectrum. Thus, our proposed biosensor presented sensitive detection of biolayer and specific identification of constituent molecules. It is helpful to interpret the protein's misfolding behavior on the molecular level by associating the biolayer's structure and the constituent molecule's conformational change.


Assuntos
Amidas , Proteínas Amiloidogênicas , Conformação Proteica , Eletricidade , Rotação
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