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1.
Phytomedicine ; 131: 155765, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38851105

RESUMO

BACKGROUND: Infection by Toxoplasma gondii can lead to severe pneumonia, with current treatments being highly inadequate. The NLRP3 inflammasome is one member of the NOD-like receptor family with a pyrin domain, which is crucial in the innate immune defense against T. gondii. Research has shown that resveratrol (RSV) prevents lung damage caused by this infection by inhibiting the T. gondii-derived heat shock protein 70/TLR4/NF-κB pathway, thus reducing the macrophage-driven inflammatory response. However, it should be mentioned that the participation of NLRP3 inflammasome in the immune response to the lung injuries caused by T. gondii infections is not entirely clear. PURPOSE: This study aims to clarify how RSV ameliorates lung damage triggered by Toxoplasma gondii infection, with a particular focus on the pathway involving TLR4, NF-κB, and the NLRP3 inflammasome. METHODS: Both in vitro and in vivo models of infection were developed by employing the RH strain of T. gondii in BALB/c mice and RAW 264.7 macrophage cell lines. The action mechanism of RSV was explored using techniques such as molecular docking, surface plasmon resonance, ELISA, Western blot, co-immunoprecipitation, and immunofluorescence staining. RESULTS: Findings indicate that the suppression of TLR4 or NF-κB impacts the levels of proteins associated with the NLRP3 inflammasome pathway. Additionally, a significant affinity for binding between RSV and NLRP3 was observed. Treatment with RSV led to a marked reduction in the activation and formation of the NLRP3 inflammasome within lung tissues and RAW 264.7 cells, alongside a decrease in IL-1ß concentrations in the bronchoalveolar lavage fluid. These outcomes align with those seen when using the NLRP3 inhibitor CY-09. Moreover, the application of CY-09 prior to RSV negated the latter's anti-inflammatory properties. CONCLUSION: Considering insights from previous research alongside the outcomes of the current investigation, it appears that the TLR4/NF-κB/NLRP3 signaling pathway emerges as a promising target for immunomodulation to alleviate lung injury from T. gondii infection. The evidence gathered in this study lays the groundwork for the continued exploration and potential future clinical deployment of RSV as a therapeutic agent with anti-Toxoplasma properties and the capability to modulate the inflammatory response.

2.
Heliyon ; 10(2): e24372, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38304841

RESUMO

Objectives: Patients with epidermal growth factor receptor (EGFR) mutations in lung adenocarcinoma (LUAD) can benefit from individualized targeted therapy. This study aims to develop, compare, analyse prediction models based on dual-energy spectral computed tomography (DESCT) and CT-based radiomic features to non-invasively predict EGFR mutation status in LUAD. Materials and methods: Patients with LUAD (n = 175), including 111 patients with and 64 patients without EGFR mutations, were enrolled in the current study. All patients were randomly divided into a training dataset (122 cases) and validation dataset (53 cases) at a ratio of 7:3. After extracting CT-based radiomic, DESCT and clinical features, we built seven prediction models and a nomogram of the best prediction. Receiver operating characteristic (ROC) curves and the mean area under the curve (AUC) values were used for comparisons among the models to obtain the best prediction model for predicting EGFR mutations. Results: The best distinguishing ability is the combined model incorporating radiomic, DESCT and clinical features for predicting the EGFR mutation status with an AUC of 0.86 (95 % CI: 0.79-0.92) in the training group and an AUC value of 0.83 (95 % CI: 0.73, 0.96) in the validation group. Conclusions: Our study provides a predictive nomogram non-invasively with a combination of CT-based radiomic, DESCT and clinical features, which can provide image-based biological information for targeted therapy of LUAD with EGFR mutations.

3.
Eur Radiol ; 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38224375

RESUMO

OBJECTIVES: As a novel imaging marker, pericoronary fat attenuation index (FAI) reflects the local coronary inflammation which is one of the major mechanisms for in-stent restenosis (ISR). We aimed to validate the ability of pericoronary FAI to predict ISR in patients undergoing percutaneous coronary intervention (PCI). MATERIALS AND METHODS: Patients who underwent coronary CT angiography (CCTA) before PCI within 1 week between January 2017 and December 2019 at our hospital and had follow-up invasive coronary angiography (ICA) or CCTA were enrolled. Pericoronary FAI was measured at the site where stents would be placed. ISR was defined as ≥ 50% diameter stenosis at follow-up ICA or CCTA in the in-stent area. Multivariable analysis using mixed effects logistic regression models was performed to test the association between pericoronary FAI and ISR at lesion level. RESULTS: A total of 126 patients with 180 target lesions were included in the study. During 22.5 months of mean interval time from index PCI to follow-up ICA or CCTA, ISR occurred in 40 (22.2%, 40/180) stents. Pericoronary FAI was associated with a higher risk of ISR (adjusted OR = 1.12, p = 0.028). The optimum cutoff was - 69.6 HU. Integrating the dichotomous pericoronary FAI into current state of the art prediction model for ISR improved the prediction ability of the model significantly (△area under the curve = + 0.064; p = 0.001). CONCLUSION: Pericoronary FAI around lesions with subsequent stent placement is independently associated with ISR and could improve the ability of current prediction model for ISR. CLINICAL RELEVANCE STATEMENT: Pericoronary fat attenuation index can be used to identify the lesions with high risk for in-stent restenosis. These lesions may benefit from extra anti-inflammation treatment to avoid in-stent restenosis. KEY POINTS: • Pericoronary fat attenuation index reflects the local coronary inflammation. • Pericoronary fat attenuation index around lesions with subsequent stents placement can predict in-stent restenosis. • Pericoronary fat attenuation index can be used as a marker for future in-stent restenosis.

4.
Radiology ; 308(2): e230124, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37606570

RESUMO

Background Lipid-rich plaques detected with intravascular imaging are associated with adverse cardiovascular events in patients with non-ST-segment elevation (NSTE) acute coronary syndrome (ACS). But evidence about the prognostic implication of coronary CT angiography (CCTA) in NSTE ACS is limited. Purpose To assess whether quantitative variables at CCTA that reflect lipid content in nonrevascularized plaques in individuals with NSTE ACS might be predictors of subsequent nonrevascularized plaque-related major adverse cardiovascular events (MACEs). Materials and Methods In this multicenter prospective cohort study, from November 2017 to January 2019, individuals diagnosed with NSTE ACS (excluding those at very high risk) were enrolled and underwent CCTA before invasive coronary angiography (ICA) within 1 day. Lipid core was defined as areas with attenuation less than 30 HU in plaques. MACEs were defined as cardiac death, myocardial infarction, hospitalization for unstable angina, and revascularization. Participants were followed up at 6 months, 12 months, and annually thereafter for at least 3 years (ending by July 2022). Multivariable analysis using Cox proportional hazards regression models was performed to determine the association between lipid core burden, lipid core volume, and future nonrevascularized plaque-related MACEs at both the participant and plaque levels. Results A total of 342 participants (mean age, 57.9 years ± 11.1 [SD]; 263 male) were included for analysis with a median follow-up period of 4.0 years (IQR, 3.6-4.4 years). The 4-year nonrevascularized plaque-related MACE rate was 23.9% (95% CI: 19.1, 28.5). Lipid core burden (hazard ratio [HR], 12.6; 95% CI: 4.6, 34.3) was an independent predictor at the participant level, with an optimum threshold of 2.8%. Lipid core burden (HR, 12.1; 95% CI: 6.6, 22.3) and volume (HR, 11.0; 95% CI: 6.5, 18.4) were independent predictors at the plaque level, with an optimum threshold of 7.2% and 10.1 mm3, respectively. Conclusion In NSTE ACS, quantitative analysis of plaque lipid content at CCTA independently predicted participants and plaques at higher risk for future nonrevascularized plaque-related MACEs. Chinese Clinical Trial Registry no. ChiCTR1800018661 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Tavakoli and Duman in this issue.


Assuntos
Síndrome Coronariana Aguda , Angiografia por Tomografia Computadorizada , Humanos , Masculino , Pessoa de Meia-Idade , Síndrome Coronariana Aguda/diagnóstico por imagem , Angiografia Coronária , Estudos Prospectivos , Lipídeos
5.
Int Immunopharmacol ; 118: 110031, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36933491

RESUMO

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that causes pulmonary toxoplasmosis, although its pathogenesis is incompletely understood. There is no cure for toxoplasmosis. Coixol, a plant polyphenol extracted from coix seeds, has a variety of biological activities. However, the effects of coixol on T. gondii infection have not been clarified. In this study, we infected a mouse macrophage cell line (RAW 264.7) and BALB/c mice with the T. gondii RH strain to establish infection models in vitro and in vivo, respectively, to explore protective effects and potential mechanisms of coixol on lung injury caused by T. gondii infection. Anti-T. gondii effects and underlying anti-inflammatory mechanisms of coixol were investigated by real-time quantitative PCR, molecular docking, localized surface plasmon resonance, co-immunoprecipitation, enzyme-linked immunosorbent assay, western blotting, and immunofluorescence microscopy. The results show that coixol inhibits T. gondii loads and T. gondii-derived heat shock protein 70 (T.g.HSP70) expression. Moreover, coixol reduced inflammatory cell recruitment and infiltration, and ameliorated pathological lung injury induced by T. gondii infection. Coixol can directly bind T.g.HSP70 or Toll-like receptor 4 (TLR4) to disrupt their interaction. Coixol prevented overexpression of inducible nitric oxide synthase, tumor necrosis factor-α, and high mobility group box 1 by inhibiting activation of the TLR4/nuclear factor (NF)-κB signaling pathway, consistent with effects of the TLR4 inhibitor CLI-095. These results indicate that coixol improves T. gondii infection-induced lung injury by interfering with T.g.HSP70-mediated TLR4/NF-κB signaling. Altogether, these findings suggest that coixol is a promising effective lead compound for the treatment of toxoplasmosis.


Assuntos
Lesão Pulmonar , Toxoplasma , Toxoplasmose , Animais , Camundongos , Toxoplasma/metabolismo , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Lesão Pulmonar/tratamento farmacológico , Simulação de Acoplamento Molecular , Toxoplasmose/tratamento farmacológico , Transdução de Sinais , Proteínas de Choque Térmico HSP70/metabolismo
6.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 38(4): 348-355, 2022 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-36414560

RESUMO

Objective: To investigate the role of Cav1.2 and its possible mechanism in the apoptosis of cochlear spiral ganglion neurons(SGNs) induced by cisplatin (CDDP) in C57BL/6J mice. Methods: Animal experiment: 8-week-old male C57BL/6J mice were randomly divided into the following two groups (10 mice/group) : normal saline group (Control group) and Cisplatin group (Cisplatin group). The Control group received daily intraperitoneal injections of normal saline, Cisplatin group was injected with cisplatin intraperitoneally at a dose of 3 mg/kg at the first 4 days of each cycle, and normal saline was injected daily at the last 10 days,repeat for 3 cycles. After administration, auditory threshold was detected by auditory brainstem response (ABR). Blood samples were collected from inner canthus of mice, and cochlea was cut off from neck. SOD and MDA kits were used to detect SOD activity and MDA content in serum and cochlea tissues. The expressions of apoptosis proteins in cochlear tissues were detected by Western blot. Morphological changes of spiral ganglion in mouse cochlea were observed by hematoxylin-eosin (HE) staining. TUNEL staining was used to observe the apoptosis of SGNs in cochlea of mice. The distribution and expression of Cav1.2 in SGNs of cochlea were observed by immunofluorescence. Cell experiment: Primary cultured SGNs were randomly divided into: control group (Control), solvent group (DMSO), Cav1.2 blocker group (N), cisplatin group, cisplatin and Cav1.2 blocker co-incubation group (Cisplatin+N). 5 µmol/L cisplatin was selected to treat SGNs based on the results of CCK8. Western blot was used to detect the protein expressions of Cav1.2.and apoptotic proteins. Hoechst33342 staining was used to observe the apoptosis of each group. Flow cytometry was used to detect the apoptosis rate of each group. Mitochondrial superoxide indicator (MitoSOXTM-Red) was used to detect the ROS release of mitochondria. Results: Animal experiments: Compared to the Control group, the hearing threshold was increased in Cisplatin group (P<0.01), the content of MDA in serum and cochlea tissues, apoptosis protein Cleaved caspase-3, Bax protein level, TUNEL positive rate, Cav1.2 protein expression level were increased significantly (P<0.05, P<0.01); the activity of SOD in serum and cochlear tissue, anti-apoptotic protein bcl-2 protein level and SGCs density in cochlear tissue were decreased significantly (P<0.05, P<0.01). Cell tests: Compared with the Control group, the expression of Cav1.2, apoptosis rate, Cleaved caspase-3, Bax protein level, intracellular calcium ion concentration, and ROS release were increased significantly only in Cisplatin group (P<0.05, P<0.01). The levels of bcl-2 protein and mitochondrial membrane potential were decreased significantly (P<0.01). Cav1.2 blockers could partially reverse the above changes (P<0.05). Conclusion: Cisplatin may increase intracellular Ca2+ concentration through up-regulation of Cav1.2, and then damage mitochondria, causing oxidative stress injury of SGNs and inducing neuronal apoptosis.


Assuntos
Cisplatino , Gânglio Espiral da Cóclea , Masculino , Camundongos , Animais , Gânglio Espiral da Cóclea/metabolismo , Cisplatino/farmacologia , Cisplatino/metabolismo , Proteína X Associada a bcl-2/metabolismo , Caspase 3/metabolismo , Camundongos Endogâmicos C57BL , Solução Salina , Espécies Reativas de Oxigênio/metabolismo , Cóclea/metabolismo , Apoptose , Neurônios , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Superóxido Dismutase/metabolismo
7.
Ann Transl Med ; 9(9): 787, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34268400

RESUMO

BACKGROUND: The number of citations of an article reflects its impact on the scientific community. The aim of this study was to identify and characterize the 100 most cited articles on lung cancer screening. METHODS: The 100 most cited articles on lung cancer screening published in all scientific journals were identified using the Web of Science database. Relevant data, including the number of citations, publication year, publishing journal and impact factor (IF), authorship and country of origin, article type and study design, screening modality, and main topic, were collected and analyzed. RESULTS: The 100 most cited articles were all English and published between 1973 and 2017, with 81 published after 2000. The mean number of citations was 292.90 (range 100-3,910). Sixty articles originated from the United States. These articles were published in 32 journals; there was a statistically significant positive correlation between journal IF and the number of citations (r=0.238, P=0.018). Seventy-nine articles were original research of which 37.9% were about results from randomized controlled trials (RCTs). The most common screening modalities in these articles were low-dose computed tomography (LDCT) (n=78), followed by chest X-ray radiography (CXR) and sputum cytology (n=11). The most common topic in these articles was screening test effectiveness. CONCLUSIONS: Our study presents a detailed list and analysis of the 100 most cited articles published about lung cancer screening which provides insight into the historical developments and key contributions in this field.

8.
Transl Cancer Res ; 10(5): 2509-2515, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-35116566

RESUMO

With the application of computed tomography (CT) imaging technology, the incidence rate of multiple primary lung cancer has gradually increased. However, the prevalence of concomitant epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene (KRAS) mutations in patients with non-small cell lung cancer (NSCLC) is low, and cases of concomitant EGFR and KRAS mutations have rarely been reported. In this case, we report a 71-year-old male patient with multiple primary lung adenocarcinoma harboring different gene mutation subtypes of KRAS and EGFR. The lesions in different lung lobes had distinct imaging features. One lesion was a solid mass in the upper lobe of the left lung, and the other was a cyst-like lung adenocarcinoma in the upper lobe of the right lung. Laboratory tests were positive for the marker carcinoembryonic antigen (CEA). The patient underwent thoracoscopic resection of the bilateral lung lesions, received chemotherapy and immunosuppressant therapy and exhibited progression-free survival (PFS) for 1 year. Later, the patient developed mediastinal lymph node and brain metastasis and died of multiple metastases. It is important to note that lung lesions with distinct imaging features may be associated with different types of gene mutations. Prediction of the gene mutation phenotype of lesions based on differences in imaging features and the biological behavior of genes, including the coexistence of EGFR and KRAS mutations, will undoubtedly assist the clinical development of individualized diagnosis and treatment planning.

9.
Transl Cancer Res ; 10(9): 4217-4231, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35116717

RESUMO

OBJECTIVE: The purpose of this paper was to perform a narrative review of current research evidence on conventional computed tomography (CT) imaging features and CT image-based radiomic features for predicting gene mutations in lung adenocarcinoma and discuss how to translate the research findings to guide future practice. BACKGROUND: Lung cancer, especially lung adenocarcinoma, is the leading cause of cancer-related deaths. With advances in the diagnosis and treatment of lung adenocarcinoma with the emergence of molecular testing, the prediction of oncogenes and even drug resistance gene mutations have become key to individualized and precise clinical treatment in order to prolong survival and improve quality of life. The progress of imageological examination includes the development of CT and radiomics are promising quantitative methods for predicting different gene mutations in lung adenocarcinoma, especially common mutations, such as epidermal growth factor receptor (EGFR) mutation, anaplastic lymphoma kinase (ALK) mutation and Kirsten rat sarcoma viral oncogene (KRAS) mutation. METHODS: The PubMed electronic database was searched along with a set of terms specific to lung adenocarcinoma, radiomics (including texture analysis), CT, computed tomography, EGFR, ALK, KRAS, rearranging transfection (RET) rearrangement and c-ros oncogene 1 (ROS-1), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), and human epidermal growth factor receptor 2 (HER2) mutations et al. This review has been reported in compliance with the Narrative Review checklist guidelines. From each full-text article, information was extracted regarding a set of terms above. CONCLUSIONS: Research on the application of conventional CT features and CT image-based radiomic features for predicting the gene mutation status of lung adenocarcinoma is still in a preliminary stage. Noninvasively determination of mutation status in lung adenocarcinoma before targeted therapy with conventional CT features and CT image-based radiomic features remains both hopes and challenges. Before radiomics could be applied in clinical practice, more work needs to be done.

10.
Ann Transl Med ; 7(14): 308, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31475178

RESUMO

BACKGROUND: Primary colorectal lymphoma (PCL) is a rare disorder, the accurate imaging diagnosis of which remains a clinical challenge. This study aimed to characterize the imaging features of PCL by double-contrast barium enema (DCBE) examination and computed tomography (CT) and correlate them with histopathological findings. METHODS: DCBE (n=6) and CT (n=19) findings for 19 pathologically proven PCLs were evaluated and compared with histopathological findings in this retrospective analysis. RESULTS: Non-Hodgkin lymphoma was present in all patients, and the most common histological type was diffuse large B-cell lymphoma (63.2%, 12/19). The most common site was the ileocecum (84.2%, 16/19). CT revealed circumferential infiltrative lesions (68.4%, 13/19), polypoid masses (26.3%, 5/19) and ulcerative lesions (5.3%, 1/19). Most (94.7%, 18/19) lesions appeared as moderate enhancements. Fourteen (73.7%, 14/19) patients had serous membrane infiltration presenting as a poorly defined serous membrane and focal opacities in the pericolonic fat. Regional lymph node involvement was observed in twelve (63.2%, 12/19) patients who presented with aggregated nodules or masses. Frequent findings of the DCBE exam included a filling defect and niche with slight mucosal destruction, mild luminal narrowing and preserved peristalsis. The imaging appearance reflected the gross pathological findings well, although the preoperative diagnostic accuracy was low. CONCLUSIONS: The imaging features of PCL have a relatively characteristic appearance but are still, at times, hardly differentiated from carcinoma. Familiarity with the radiological features of PCL on DCBE and CT can help ensure a correct diagnosis.

11.
Chem Commun (Camb) ; 48(85): 10565-7, 2012 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-23001350

RESUMO

Lys16 is present in the core region of the amyloid ß (Aß) self-assembly in Alzheimer's disease. Here we report that the P9-NCS peptide can covalently react with Lys16 and inhibit Aß neurotoxic fibrillization. Moreover P9-NCS has high selectivity and it cannot react with amylin, insulin, fetal bovine serum, Q11 and MUC1 peptide.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Peptídeos/metabolismo , Sequência de Aminoácidos , Peptídeos beta-Amiloides/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Lisina/metabolismo , Camundongos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Peptídeos/química , Peptídeos/farmacologia , Ligação Proteica
12.
J Am Chem Soc ; 134(21): 8730-3, 2012 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-22587010

RESUMO

In the development of vaccines for epithelial tumors, the key targets are MUC1 proteins, which have a variable number of tandem repeats (VNTR) bearing tumor-associated carbohydrate antigens (TACAs), such as Tn and STn. A major obstacle in vaccine development is the low immunogenicity of the short MUC1 peptide. To overcome this obstacle, we designed, synthesized, and evaluated several totally synthetic self-adjuvanting vaccine candidates with self-assembly domains. These vaccine candidates aggregated into fibrils and displayed multivalent B-cell epitopes under mild conditions. Glycosylation of Tn antigen on the Thr residue of PDTRP sequence in MUC1 VNTR led to effective immune response. These vaccines elicited a high level antibody response without any adjuvant and induced antibodies that recognized human breast tumor cells. These vaccines appeared to act through a T-cell independent pathway and were associated with the activation of cytotoxic T cells. These fully synthetic, molecularly defined vaccine candidates had several features that hold promise for anticancer therapy.


Assuntos
Vacinas Anticâncer/síntese química , Vacinas Anticâncer/imunologia , Desenho de Fármacos , Mucina-1/química , Neoplasias/patologia , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/imunologia , Sequência de Aminoácidos , Vacinas Anticâncer/química , Linhagem Celular Tumoral , Humanos , Repetições de Microssatélites , Dados de Sequência Molecular , Mucina-1/genética , Neoplasias/imunologia , Neoplasias/terapia , Fragmentos de Peptídeos/química , Multimerização Proteica , Estrutura Terciária de Proteína
13.
Environ Sci Technol ; 45(24): 10627-33, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22066493

RESUMO

By grafting butyl or ethyl onto tetramethylethylenediamine, quaternary ammonium salts with two positive charge centers were formed at the first step. Metathesis with Ag(2)O followed. Through neutralization with glycine, l-alanine, or valine, a series of new ditetraalkylammonium amino acid ionic liquids (DILs) for CO(2) capture were generated. The structures of DILs, as shown in Figure 1, were verified by using (1)H NMR and EA. These DILs were found to be of quite high viscosity which militated against their industrial application in CO(2) removal. Drawing on the experience of mixed amines' aqueous solutions, these DILs were blended with water or N-methyldiethanolamine (MDEA) aqueous solutions to act as special absorbents of CO(2). Using a Double-Tank Absorption System, the absorption performance of these DIL solutions was investigated in detail. The experimental results indicated that among the three aqueous solutions of DILs (20%, 40%, and 80 wt %), the solution of 40% DIL had a higher absorption rate of CO(2) than the other two, demonstrating the different effects of concentration and viscosity on the absorption. The solution of 40% DIL or the 15% DIL + 15% MDEA had much higher capacity for CO(2) than the corresponding monocation tetraalkylammonium AAILs, due to the special structure of the dication which could influence the solubility of CO(2) in the aqueous solution.


Assuntos
Dióxido de Carbono/química , Líquidos Iônicos/química , Compostos de Amônio Quaternário/química , Poluentes Químicos da Água/química , Adsorção , Poluição do Ar/prevenção & controle , Dióxido de Carbono/análise , Recuperação e Remediação Ambiental , Modelos Químicos , Estrutura Molecular , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise
14.
FEBS J ; 276(12): 3365-71, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19438709

RESUMO

One of the most important pathological features of type 2 diabetes is the formation of islet amyloid, of which the major component is amylin peptide. However, the presence of a natural inhibitor such as insulin may keep amylin stable and physiologically functional in healthy individuals. Some previous studies demonstrated that insulin was a potent inhibitor of amylin fibril formation in vitro, but others obtained contradictory results. Hence, it is necessary to elucidate the effects of insulin on amylin aggregation. Here we report that insulin is a kinetic inhibitor of amylin aggregation, only keeping its inhibitory effect for a limited time period. Actually, insulin promotes amylin aggregation after long-term incubation. Furthermore, we found that this promotional effect could be attributed to the copolymerization of insulin and amylin. We also found that insulin copolymerized with amylin monomer or oligomer rather than preformed amylin fibrils. These results suggest that the interaction between insulin and amylin may contribute not only to the inhibition of amylin aggregation but also to the coaggregation of both peptides in type 2 diabetes.


Assuntos
Amiloide/química , Insulina/química , Sequência de Aminoácidos , Amiloide/metabolismo , Amiloide/ultraestrutura , Humanos , Insulina/metabolismo , Insulina/farmacologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Cinética , Luz , Microscopia Eletrônica , Dados de Sequência Molecular , Polímeros/química , Polímeros/metabolismo , Ligação Proteica , Conformação Proteica/efeitos dos fármacos , Espalhamento de Radiação , Termodinâmica
15.
Biochem Biophys Res Commun ; 368(2): 414-8, 2008 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-18243137

RESUMO

The misfolding of islet amyloid polypeptide (IAPP, amylin) results in the formation of islet amyloid, which is one of the most common pathological features of type 2 diabetes (T2D). Amylin, a 37-amino-acid peptide co-secreted with insulin and apolipoprotein E (ApoE) from the beta-cells of pancreatic islets, is thought to be responsible for the reduced mass of insulin-producing beta-cells. However, neither the relationship between amylin and ApoE nor the biological consequence of amylin misfolding is known. Here we have characterized the interaction between ApoE4 and amylin in vitro. We found that ApoE4 can strongly bind to amylin, and insulin can hardly inhibit amylin-ApoE binding. We further found that amylin fibrillization can be prevented by low concentration of ApoE4 and promoted by high concentration of ApoE4. Taken together, we propose that under physiological conditions ApoE4 efficiently binds and sequesters amylin, preventing its aggregation, and in T2D the enhanced ApoE4-amylin binding leads to the critical accumulation of amylin, facilitating islet amyloid formation.


Assuntos
Amiloide/química , Amiloide/ultraestrutura , Apolipoproteína E4/química , Apolipoproteína E4/ultraestrutura , Sítios de Ligação , Dimerização , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Complexos Multiproteicos/química , Complexos Multiproteicos/ultraestrutura , Ligação Proteica
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