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1.
Pediatr Rheumatol Online J ; 21(1): 124, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37848905

RESUMO

BACKGROUND: Monogenic autoinflammatory diseases (AIDs) are rare inflammatory diseases caused by genetic variants. The pathogenesis is complex and treatment options are limited. This study aimed to describe the safety and efficacy of thalidomide in the treatment of monogenic AIDs. METHODS: This was a single-center, single-arm, real-world study. From September 2016 to August 2021, patients with monogenic AIDs who met the inclusion and exclusion criteria were given thalidomide for 12 months. There was a 3-month run-in period before dosing. The efficacy and adverse events were evaluated and recorded every 3 months. After 3 and 12 months of thalidomide treatment, clinical manifestations, disease activity score, inflammatory markers, and background medication adjustments were compared with baseline for efficacy analyses. RESULTS: A total of 16 patients entered this study, including 3 with Aicardi-Goutières syndrome (AGS), 4 Blau syndrome, 2 chronic infantile neurologic cutaneous articular syndrome (CINCA), 2 A20 haploinsufficiency (HA20), 1 adenosine deaminase 2 deficiency(DADA2), 1 familial Mediterranean fever (FMF),1 tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS), 1 PLCγ2-associated antibody deficiency and immune dysregulation (PLAID), and 1 stimulator of interferon genes-associated vasculopathy with onset in infancy(SAVI). The efficacy rate in the 16 patients after 3-month and 12-month thalidomide treatment in patients was 56.3%. Twelve patients completed the study, the fever improved in all of them, rash improved in 7 patients, and 5 patients stopped using glucocorticoids or other immunosuppressive agents. C-reactive protein was normal in 8 patients and erythrocyte sedimentation rate was normal in 11 patients. Anorexia and nausea occurred in 2 cases, with no other reported drug-related adverse reactions. CONCLUSION: The largest cohort of monogenic AIDs with the treatment of thalidomide demonstrated that thalidomide can help reduce disease activity and inflammation, reduce the dosage of glucocorticoids, and improve clinical outcomes. Thalidomide is relatively safe in monogenic AIDs.


Assuntos
Síndromes Periódicas Associadas à Criopirina , Febre Familiar do Mediterrâneo , Doenças Hereditárias Autoinflamatórias , Humanos , Criança , Talidomida/efeitos adversos , Adenosina Desaminase , Peptídeos e Proteínas de Sinalização Intercelular , Doenças Hereditárias Autoinflamatórias/tratamento farmacológico , Doenças Hereditárias Autoinflamatórias/genética , Febre Familiar do Mediterrâneo/tratamento farmacológico
2.
World J Pediatr ; 19(7): 674-686, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36622578

RESUMO

BACKGROUND: Progressive pseudorheumatoid dysplasia (PPRD) is a rare genetic disease with autosomal recessive inheritance. There was a lack of genotype-phenotype correlation data from the Chinese population. This study aimed to identify the genotype and phenotype characteristics of Chinese PPRD patients and to conduct a genotype-phenotype analysis of Chinese PPRD patients. METHODS: Genetic analysis was performed for suspected PPRD patients from Peking Union Medical College Hospital. Medical records were collected from the electronic medical record system and patient-held portable health records. Published Chinese PPRD cases were gathered from both international and Chinese local databases. We collected demographic information, genetic variants, clinical manifestations, and imaging characteristics for further analysis. RESULTS: We included 105 Chinese PPRD patients in the current study. Thirty-three variants, including nine novels and five hotspot variants, were identified, with 26/33 (79%) variants exclusively seen in the Chinese population. Chinese PPRD patients share a phenotype similar to that in international reports. Joint involvement may progress with age (R2 = 0.2541). Long bone shortening and severe deformities occur in three patients with biallelic null variants, of which at least one variant is located in exon 2. Among hotspot variants, c.624dupA (p.C209Mfs*21) were associated with later onset and more involved joints. Elbow joints were more likely to be affected in patients carrying c.624dupA (p.C209Mfs*21) and c.866dupA (p.S209Efs*13). Shoulder joints are more likely to be involved in patients with biallelic null variants (P = 0.027). CONCLUSIONS: Chinese PPRD patients share a unique mutation spectrum. Among the five hotspot variants, c.624dupA is associated with later onset of disease, more extensive joint involvement, and a tendency to affect elbow joints. Biallelic null variants with at least one variant in exon 2 could be a likely cause of long bone shortening and severe deformities.


Assuntos
População do Leste Asiático , Artropatias , Humanos , População do Leste Asiático/genética , Genótipo , Mutação , Fenótipo , Estudos Retrospectivos , Artropatias/congênito , Artropatias/genética
4.
Oxid Med Cell Longev ; 2022: 6482363, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602097

RESUMO

Background: Endothelial dysfunction and cardiomyopathy are considered to be important vascular complications associated with diabetes. This study was designed to investigate whether capsaicin (CAP), a selective TRPV1 agonist, could prevent diabetes-induced endothelial dysfunction and cardiomyopathy. Methods: Male Sprague Dawley rats aged 8 weeks were injected intraperitoneally with streptozotocin (STZ, 50 mg/kg) to establish the diabetes model. The diabetic rats were randomly divided into the untreated diabetes group (DM, 10/group) and diabetes plus CAP treatment group (DM+CAP, 10/group); meanwhile, the nondiabetic healthy rats were used as normal controls (10/group). DM+CAP group were treated with CAP by gavage for 8 weeks. The cultured mouse vascular endothelial cells were exposed to different concentrations of glucose in the presence or absence of CAP treatment. The TRPV1 inhibitor capsazepine (CPZ) and eNOS inhibitor L-NAME were used in vivo and in vitro experiment. Results: CAP treatment significantly decreased the serum total cholesterol (TC) and total triglyceride (TG) and ameliorated the pathogenesis and fibrosis in the heart, while did not significantly improve plasma glucose level and the body weights of diabetic rats. In addition, CAP enhanced the expression of TRPV1 and eNOS in the heart and normalized the vascular permeability under diabetic state. Similarly, CAP treatment also increased nitric oxide and reduced reactive oxygen species. The same results were observed in cultured mouse vascular endothelial cells by CAP treatment. These beneficial effects of CAP were abolished by either CPZ or L-NAME. Conclusions: CAP might protect against hyperglycemia-induced endothelial dysfunction and diabetic cardiomyopathy through TRPV1/eNOS pathway.


Assuntos
Diabetes Mellitus Experimental , Cardiomiopatias Diabéticas , Doenças Vasculares , Animais , Capsaicina/farmacologia , Capsaicina/uso terapêutico , Diabetes Mellitus Experimental/metabolismo , Cardiomiopatias Diabéticas/metabolismo , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Masculino , Camundongos , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase Tipo III/metabolismo , Ratos , Ratos Sprague-Dawley , Estreptozocina/farmacologia , Canais de Cátion TRPV/metabolismo , Doenças Vasculares/patologia
5.
Front Med (Lausanne) ; 8: 781689, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34966761

RESUMO

Background: Postoperative nausea and vomiting (PONV) is a common and disturbing problem in patients undergoing ambulatory thyroidectomy. This prospective trial aimed to explore whether dexmedetomidine (DEX) combined with azasetron (AZA) can further drop the incidence of PONV in patients undergoing ambulatory thyroidectomy compared with AZA. Methods: This single-center, randomized, double-blind trial involved 172 adult patients undergoing ambulatory thyroidectomy. The individuals were randomized to DEX + AZA group and AZA group. In the DEX + AZA group, patients received dexmedetomidine 0.5 µg kg-1 for 10 min and then the infusion rate was held at 0.1 µg kg-1 h-1 until the completion of the operation, while the same amount of 0.9% saline in the AZA group. At the completion of the surgery, 10 mg azasetron was administered to every patient in both groups. The primary outcome was the incidence of 24 h PONV after ambulatory thyroidectomy. The secondary outcomes included residence time in recovery room, pain scores, severity of nausea, and adverse events. Results: No significant difference was found in the incidence of 24-h PONV between the DEX + AZA group and the AZA group [36% (30 of 84) vs. 38% (32 of 84); relative risk, 0.94; 95% confidence interval (CI), 0.63-1.40; P = 0.749]. The incidence of severe nausea was similar between the DEX + AZA group and the AZA group [57% (12 of 21) vs. 43% (9 of 21); relative risk, 1.33; 95% CI, 0.72-2.50; P = 0.355]. Conclusions: Intraoperative dexmedetomidine combined with azasetron failed to drop the incidence of 24-h PONV compared with azasetron alone in patients undergoing ambulatory thyroidectomy.

6.
Front Oncol ; 11: 669746, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249706

RESUMO

Cancer is a leading contributor to deaths worldwide. Surgery is the primary treatment for resectable cancers. Nonetheless, it also results in inflammatory response, angiogenesis, and stimulated metastasis. Local anesthetic lidocaine can directly and indirectly effect different cancers. The direct mechanisms are inhibiting proliferation and inducing apoptosis via regulating PI3K/AKT/mTOR and caspase-dependent Bax/Bcl2 signaling pathways or repressing cytoskeleton formation. Repression invasion, migration, and angiogenesis through influencing the activation of TNFα-dependent, Src-induced AKT/NO/ICAM and VEGF/PI3K/AKT signaling pathways. Moreover, the indirect influences are immune regulation, anti-inflammation, and postoperative pain relief. This review summarizes the latest evidence that revealed potential clinical benefits of lidocaine in cancer treatment to explore the probable molecular mechanisms and the appropriate dose.

7.
Mol Biol Rep ; 47(7): 5165-5173, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32572732

RESUMO

Parthenolide (PTL) is a natural product from the shoots of Tanacetum parthenium, which has immunomodulatory effects in multiply type of diseases. This study aimed to explore the effect and the underlying mechanism of PTL on the anti-apoptotic and anti- inflammatory ability of tweak-induced podocytes. Conditionally immortalized mouse podocytes were incubated with Tumor necrosis factor-like weak inducer of apoptosis (Tweak, 100 ng/ml), PTL(10 µM) or Tweak + PTL for 12 h, 24 and 48 h, respectively. Podocytes viability was detected by CCK-8 assay. Tweak and Cxcl16 expression were evaluated by western blot and immunofluorescence assay. Dil-oxLDL stain was detected by immunofluorescence analysis. Intracellular Total Cholesterol (TC) content was measured through TC detection Kit. These results demonstrated that the podocytes cells viability was gradually decreased after treatment with different concentrations of Tweak (0, 50, 100, 150). Tweak and Cxcl16 protein expression in mouse podocytes treated with tweak were remarkably elevated and were found to have higher intracellular lipid accumulation compared with the control group, whereas co-administration with PTL, tweak and Cxcl16 expression as well as the intracellular lipid accumulation were notablely decreased in tweak-induced podocytes. Therefore, our conclusion was that tweak and Cxcl16 were involved in the regulation of tweak-induced podocytes injury. Meanwhile, the anti-apoptotic and anti-inflammatory effect of PTL may be correlated with the tweak and Cxcl16 expression decreased.


Assuntos
Anti-Inflamatórios/farmacologia , Apoptose , Podócitos/efeitos dos fármacos , Sesquiterpenos/farmacologia , Animais , Linhagem Celular , Quimiocina CXCL16/genética , Quimiocina CXCL16/metabolismo , Colesterol/metabolismo , Camundongos , Podócitos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
8.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 31(5): 582-587, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31198144

RESUMO

OBJECTIVE: To investigate the feasibility of using optimized protocol of iodine contrast agent with fixed injection time in triple-rule-out CT examination of acute chest pain patients. METHODS: A prospective study was conducted. The patients who underwent triple-rule-out CT examination of acute chest pain at the Second Hospital of Shanxi Medical University from September 2017 to June 2018 were enrolled. According to the patient's body mass index (BMI), they were divided into BMI ≤ 23 kg/m2 group and BMI > 23 kg/m2 group. The patients in each group were subdivided into two subgroups according to the random number table, and they were given two iodine contrast injection protocols with fixed injection time (14 s). Protocol 1 was performed with 55 mL of total iodinated contrast media: iodinated contrast media was first injected at 5.0 mL/s for 8 s, followed by the same contrast media injection at 2.5 mL/s for 6 s, finally followed by injection of 40 mL of saline at a rate of 2.5 mL/s. Protocol 2 with 60 mL of total iodinated contrast media: iodinated contrast media was first injected at 5.0 mL/s for 10 s, followed by the same contrast media injection at 2.5 mL/s for 4 s, finally followed by injection of 40 mL of saline at a rate of 2.5 mL/s. The primary and objective evaluation was conducted on the image quality of the patients' blood vessels in different segments. The primary score, CT value and contrast-to-noise ratio (CNR) of the pulmonary artery, coronary artery, aorta and total effective radiation dose for the examination were recorded. RESULTS: A total of 92 patients were enrolled in the analysis. There were 44 patients in BMI≤ 23 kg/m2 group, in which 22 patients received in protocol 1 and protocol 2, 48 patients in BMI > 23 kg/m2 group, in which 24 patients in protocol 1 and protocol 2, respectively. There was no significant difference in the effective radiation dose between the two subgroups receiving different injection protocols in different BMI groups (mSv: 6.7±1.1 vs. 6.5±0.8 between protocol 1 and protocol 2 in BMI ≤ 23 kg/m2 group; 7.8±1.0 vs. 8.0±1.1 between protocol 1 and protocol 2 in BMI > 23 kg/m2 group, both P > 0.05). In BMI ≤ 23 kg/m2 group, the CT value, CNR and primary scores of pulmonary artery images in patients receiving protocol 2 were significantly higher than those receiving protocol 1 [CT value (HU): 584±110 vs. 472±86 for main pulmonary artery, 561±93 vs. 467±78 for left pulmonary artery, 555±91 vs. 472±83 for right pulmonary artery; CNR: 24.2±7.5 vs. 18.7±4.6 for main pulmonary artery, 23.2±6.8 vs. 18.6±4.8 for left pulmonary artery, 22.9±6.7 vs. 18.8±4.7 for right pulmonary artery; primary score: 4.0 (4.0, 4.0) vs. 3.5 (3.0, 4.0), all P < 0.05]; and there was no statistically significant difference in the primary or objective evaluation of coronary artery or aortic image quality between the two protocols. In BMI > 23 kg/m2 group, the CT value, CNR and primary scores of coronary artery and aortic images in patients receiving protocol 2 were significantly higher than those receiving protocol 1 [CT value (HU): 369±63 vs. 315±61 for proximal right coronary artery (RCA), 388±63 vs. 323±63 for proximal left coronary artery (LCA), 328±83 vs. 272±51 for ascending aorta, 348±82 vs. 272±49 for aortic arch; CNR: 15.0±4.6 vs. 12.3±4.7 for proximal RCA, 15.7±3.8 vs. 12.8±5.2 for proximal LCA, 13.2±5.3 vs. 10.4±4.1 for ascending aorta, 14.1±5.3 vs. 10.4±3.9 for aortic arch; primary score: 4.0 (3.0, 4.0) vs. 3.0 (3.0, 4.0) for coronary, 4.0 (3.0, 4.0) vs. 3.0 (2.0, 4.0) for aorta; all P < 0.05]; and there was no statistically significant difference in the primary or objective evaluation of pulmonary artery image quality between the two protocols. CONCLUSIONS: The effective radiation dose of triple-rule-out CT examination of acute chest pain is relatively low. The low-dose iodine contrast agent application program with fixed injection time can meet the needs of clinical diagnosis of triple-rule-out CT examination of acute chest pain patients. For patients with BMI ≤ 23 kg/m2, both protocols 1 and 2 can obtain excellent image quality; in order to avoid the influence of superior vena cava artifacts, protocol 1 is recommended. For patients with BMI > 23 kg/m2, application protocol 2 can obtain stable, excellent image quality that is more suitable for clinical applications.


Assuntos
Dor no Peito/diagnóstico por imagem , Meios de Contraste , Iodo , Tomografia Computadorizada por Raios X/métodos , Humanos , Estudos Prospectivos , Doses de Radiação
9.
Mol Biol Rep ; 46(4): 3809-3816, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31004300

RESUMO

The purpose of our research is to elucidate whether oxLDL activates P2X7R in cultured human podocytes and if the activation of P2X7R leads to podocyte apoptosis. Additionally, we explore the underlying mechanism involved in podocyte apoptosis. Immortalized human podocytes were incubated with oxLDL (80 µg/ml), P2X7R antagonist A438079 (10 µM), or the compound of A438079 and oxLDL for 48 h, respectively. Cellular apoptosis and ROS were evaluated using flow cytometer. P2X7R, Bax, and Caspase-3 protein expression were detected by western blot and immunofluorescence analysis.The expression of P2X7R, ROS, Bax, and Caspase-3 in human podocytes incubated with oxLDL was significantly up-regulated and was found to have higher intracellular lipid accumulation and podocyte apoptosis compared with the NC group. However, co-administration with A438079, ROS, Bax, and Caspase-3 expression both significantly down-regulate as well as lower lipid accumulation and cellular apoptosis in the oxLDL-induced podocyte group. We revealed that P2X7R is involved in the regulation of oxLDL-treated podocytes. Additionally, we found that the anti-apoptotic effect of A438079 is correlated with ROS, Bax, and Caspase-3 expression down-regulated.


Assuntos
Apoptose/efeitos dos fármacos , Lipoproteínas LDL/farmacologia , Podócitos/efeitos dos fármacos , Piridinas/farmacologia , Receptores Purinérgicos P2X7/metabolismo , Tetrazóis/farmacologia , Caspase 3/metabolismo , Linhagem Celular , Humanos , Podócitos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores Purinérgicos P2X7/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismo
10.
Toxins (Basel) ; 8(9)2016 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-27626447

RESUMO

Due to unavoidable contaminations in feedstuff, pigs are easily exposed to aflatoxin B1 (AFB1) and suffer from poisoning, thus the poisoned products potentially affect human health. Heretofore, the metabolic process of AFB1 in pigs remains to be clarified, especially the principal cytochrome P450 oxidases responsible for its activation. In this study, we cloned CYP3A29 from pig liver and expressed it in Escherichia coli, and its activity has been confirmed with the typical P450 CO-reduced spectral characteristic and nifedipine-oxidizing activity. The reconstituted membrane incubation proved that the recombinant CYP3A29 was able to oxidize AFB1 to form AFB1-exo-8,9-epoxide in vitro. The structural basis for the regioselective epoxidation of AFB1 by CYP3A29 was further addressed. The T309A mutation significantly decreased the production of AFBO, whereas F304A exhibited an enhanced activation towards AFB1. In agreement with the mutagenesis study, the molecular docking simulation suggested that Thr309 played a significant role in stabilization of AFB1 binding in the active center through a hydrogen bond. In addition, the bulk phenyl group of Phe304 potentially imposed steric hindrance on the binding of AFB1. Our study demonstrates the bioactivation of pig CYP3A29 towards AFB1 in vitro, and provides the insight for understanding regioselectivity of CYP3A29 to AFB1.


Assuntos
Aflatoxina B1/análogos & derivados , Citocromo P-450 CYP3A/metabolismo , Fígado/enzimologia , Ativação Metabólica , Aflatoxina B1/metabolismo , Regulação Alostérica , Animais , Sítios de Ligação , Clonagem Molecular , Citocromo P-450 CYP3A/genética , Isoenzimas , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Mutação , Ligação Proteica , Conformação Proteica , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato , Sus scrofa
11.
Biochem Pharmacol ; 86(9): 1357-65, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-24008121

RESUMO

Aflatoxin B1 (AFB1) is a severe threat to human and animal health. The aflatoxin B1 aldehyde reductase (AFAR) family specifically catalyzes AFB1-dialdehyde, a toxic metabolic intermediate of AFB1, producing a nontoxic dialcohol. Although several AFARs have been found and characterized, the binding specificity of the family for AFB1-dialdehyde remains unclear. Herein, according to the published sequence, we cloned a porcine AFAR gene. Recombinant porcine AFAR was expressed and purified from Escherichia coli as hexa-histidine tagged fusion protein. Using the cloned porcine AFAR as a model, site-directed mutagenesis combined with high performance liquid chromatography studies revealed that the substitution of Trp266 with Ala resulted in almost complete loss of catalytic activity for AFB1-dialdehyde. Interestingly, the substitution of Met86 with Ala exhibited an obviously increased activity to the dialdehyde. Based on these results and by using molecular docking simulations, this work provides a structural explanation for why the AFAR family exhibits high specificity for AFB1-dialdehyde. The Trp266 residue in porcine AFAR plays a critical role in stabilizing the binding of AFB1-dialdehyde in the active pocket through the hydrophobic interaction of the side-chain indole ring of Trp266 with the fused coumarin rings of the dialdehyde molecule. The enhanced activity of M86A may be attributed to the formed π-π stacking interaction between Trp266 and the dialdehyde. In addition, other hydrophobic residues (e.g. Phe and Trp) around the dialdehyde molecule also stabilize the substrate binding. The findings may contribute to understanding the substrate specificity of the AFAR family for AFB1-dialdehyde.


Assuntos
Aldeído Redutase/genética , Aldeído Redutase/metabolismo , Triptofano , Aflatoxina B1/metabolismo , Aldeído Redutase/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Clonagem Molecular , Cinética , Simulação de Acoplamento Molecular , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Conformação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Especificidade por Substrato , Suínos/genética , Triptofano/genética , Triptofano/metabolismo
12.
Org Lett ; 14(11): 2746-9, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22583057

RESUMO

The synthesis of a directly linked zinc chlorin dimer was first achieved by a facile and efficient oxidative coupling of zinc chlorin monomers with phenyliodine bis(trifluoroacetate) (PIFA). The reaction shows high regioselectivity at the 20-position near the hydrogenated pyrrole ring producing selective dichlorin in 74% yield.


Assuntos
Fluoracetatos , Metaloporfirinas/química , Pirróis/síntese química , Zinco/química , Iodobenzenos , Estrutura Molecular , Acoplamento Oxidativo , Pirróis/química , Estereoisomerismo , Ácido Trifluoracético/química
13.
Drug Metab Dispos ; 40(4): 788-95, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22266778

RESUMO

Mequindox (MEQ) is a novel synthetic quinoxaline 1,4-dioxides derivative, which is widely used as a veterinary drug and animal feed additive. However, the metabolic mechanism of MEQ is rarely reported. The N-oxide reduction mechanism of MEQ was reported in our previous work. In this article, the toxicity and the reduction of the carbonyl of MEQ were studied. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assays demonstrated that the carbonyl-reduced MEQ, 2-isoethanol MEQ was much less toxic than MEQ. High-performance liquid chromatography analysis showed that the cytosol extracts of chicken and pig livers were able to reduce MEQ to 2-isoethanol MEQ and the reaction was NADPH-dependent. Further study via enzyme-inhibitory experiment revealed that carbonyl reductase 1 (CBR1) participated in this metabolism. The enzyme activity analysis showed that both chicken CBR1 (cCBR1) and porcine CBR1 (pCBR1) were capable of catalyzing the carbonyl reduction of MEQ and its N-oxide reductive metabolite, 1-deoxymequindox. By comparison of the kinetic constants, we observed that the activity of cCBR1 was higher than pCBR1 to MEQ and the standard substrate of CBR1, menadione. On the other hand, both CBR1s exhibited higher activity to 1-deoxymequindox than MEQ. Mutation analysis suggested that the difference of amino acid at position 141/142 may be one possible reason that caused the activity difference between cCBR1 and pCBR1. Thus far, CBR1 was first reported to participate in the carbonyl reduction of MEQ. Our results will be helpful to recognize the metabolic pathways of quinoxaline drugs deeply and to provide a theoretical basis for controlling the negative effects of these drugs.


Assuntos
Oxirredutases do Álcool/metabolismo , Citosol/efeitos dos fármacos , Fígado/efeitos dos fármacos , Quinoxalinas/metabolismo , Oxirredutases do Álcool/genética , Sequência de Aminoácidos , Animais , Biotransformação , Sobrevivência Celular/efeitos dos fármacos , Galinhas/metabolismo , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Citosol/enzimologia , Citosol/metabolismo , Escherichia coli/genética , Células Hep G2 , Humanos , Fígado/enzimologia , Fígado/metabolismo , Dados de Sequência Molecular , Estrutura Molecular , Oxirredução , Quinoxalinas/química , Quinoxalinas/toxicidade , Alinhamento de Sequência , Especificidade da Espécie , Sus scrofa/metabolismo
14.
Mutat Res ; 741(1-2): 70-5, 2012 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-22094289

RESUMO

Mequindox, a quinoxaline-N-dioxide derivative that possesses antibacterial properties, has been widely used as a feed additive in the stockbreeding industry in China. While recent pharmacological studies have uncovered potential hazardous effects of mequindox, exactly how mequindox induces pathological changes and the cellular responses associated with its consumption remain largely unexplored. In this study, we investigated the cellular responses associated with mequindox treatment. We report here that mequindox inhibits cell proliferation by arresting cells at the G2/M phase of the cell cycle. Interestingly, this mequindox-associated deleterious effect on cell proliferation was observed in human, pig as well as chicken cells, suggesting that mequindox acts on evolutionarily conserved target(s). To further understand the mequindox-host interaction and the mechanism underlying mequindox-induced cell cycle arrest, we measured the cellular content of DNA damage, which is known to perturb cell proliferation and compromise cell survival. Accordingly, using γ-H2AX as a surrogate marker for DNA damage, we found that mequindox treatment induced cellular DNA damage, which paralleled the chemical-induced elevation of reactive oxygen species (ROS) levels. Importantly, expression of the antioxidant enzyme catalase partially alleviated these mequindox-associated effects. Taken together, our results suggest that mequindox cytotoxicity is attributable, in part, to its role as a potent inducer of DNA damage via ROS.


Assuntos
Antibacterianos/toxicidade , Dano ao DNA , Mutagênicos/toxicidade , Quinoxalinas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Criação de Animais Domésticos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos
15.
Org Lett ; 11(22): 5266-9, 2009 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-19835399

RESUMO

An efficient and metal-free oxidative method was reported for synthesis of triply linked diporphyrins with 2.5 equiv of phenyliodine bis(trifluoroacetate) (PIFA). This reaction showed high selectivity for Zn(II) porphyrins and had been successfully applied in the synthesis of a novel triply-singly interlacedly linked porphyrin array with lower energy gap.


Assuntos
Fluoracetatos , Compostos Organometálicos/síntese química , Porfirinas/química , Iodobenzenos , Estrutura Molecular , Compostos Organometálicos/química , Oxirredução , Estereoisomerismo , Ácido Trifluoracético/química , Zinco/química
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