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1.
Biochem Biophys Res Commun ; 695: 149394, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38157629

RESUMO

In addition to its role in pyroptosis and inflammatory cytokine maturation, caspase-4 (CASP4) also contributes to the fusion of phagosomes with lysosomes and cell migration. However, its role in cell division remains elusive. In this study, we demonstrate that CASP4 is indispensable for proper cell division in epithelial cells. Knockout of CASP4 (CASP4 KO) in HepG2 cells led to delayed cell proliferation, increased cell size, and increased multinucleation. In mitosis, CASP4 KO cells showed multipolar spindles, asymmetric spindle positioning, and chromosome segregation errors, ultimately increasing DNA content and chromosome number. We also found that phalloidin, a marker of filamentous actin, increased in CASP4 KO cells owing to suppressed actin depolymerization. Moreover, the levels of actin polymerization-related proteins, including Rho-associated protein kinase1 (ROCK1), LIM kinase1 (LIMK1), and phosphorylated cofilin, significantly increased in CASP4 KO cells. These results suggest that CASP4 contributes to proper cell division through actin depolymerization.


Assuntos
Fatores de Despolimerização de Actina , Actinas , Actinas/metabolismo , Fatores de Despolimerização de Actina/metabolismo , Movimento Celular , Mitose , Células Epiteliais/metabolismo , Quinases Lim/genética , Fosforilação
2.
J Org Chem ; 89(15): 10693-10697, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39008521

RESUMO

Pd/DPEphos-catalyzed direct amination of allylic alcohols with readily available ammonium acetate as a nitrogen source provides access to convenient and scalable syntheses of primary allylic amines with high monoallylation selectivity. Mechanistic studies revealed that ammonium acetate functions as a Brønsted acid to activate the hydroxyl groups and inhibit overreaction.

3.
Clin Exp Nephrol ; 27(3): 203-210, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36371578

RESUMO

BACKGROUND: Peritoneal dialysis (PD) is an important alternative treatment for end-stage renal disease. Continuous exposure to non-physiological fluids during PD is associated with pathological responses, such as sustained microinflammation, leading to tissue fibrosis and angiogenesis. However, the effect of PD fluid on submesothelial cells has not yet been investigated in detail. METHODS: We investigated the association between macrophages and the expression of matrix metalloproteinase-12 (MMP-12), an elastin proteinase secreted by macrophages, in the peritoneal tissue of rats undergoing continuous PD. RESULTS: Morphological data revealed that the submesothelial layer of the peritoneum in PD model rats was markedly thickened, with fibrosis and angiogenesis. In the fibrillization area, elastin was disorganized and fragmented, and macrophages accumulated, which tended to have M2 characteristics. The expression of MMP-12 was enhanced by continuous exposure to PD fluid, suggesting that MMP-12 expression may be involved in PD fluid-induced peritoneal damage. CONCLUSIONS: The results of this study may lead to a better understanding of the mechanisms underlying fibrosis in PD.


Assuntos
Diálise Peritoneal , Peritônio , Ratos , Animais , Peritônio/metabolismo , Metaloproteinase 12 da Matriz/metabolismo , Metaloproteinase 12 da Matriz/farmacologia , Elastina/metabolismo , Elastina/farmacologia , Soluções para Diálise/farmacologia , Fibrose
4.
Chem Pharm Bull (Tokyo) ; 71(2): 101-106, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36724973

RESUMO

Catalytic control of chemoselectivity is crucial in the synthesis of highly functionalized compounds. Although there are reports of efficient chemoselective reactions of alcohols and amines as nucleophiles, there are no reports of the chemoselective activation of alcohols and amines as electrophiles. In this study, highly O- and N-selective electrophilic activation of allylic alcohols and amines was achieved in Pd-catalyzed direct allylic alkylation. Allylamines were inherently more reactive than allylic alcohols (N-selectivity). On the other hand, the addition of catalytic amounts of 9-phenanthreneboronic acid preferentially activated allylic alcohols over allylamines (O-selectivity). Density functional theory (DFT) calculations suggested that the N-selectivity is due to the selective activation of allylic amines with ammonium cations, and boronate formation accelerates the activation of allylic alcohols.


Assuntos
Compostos Alílicos , Alilamina , Aminas , Paládio , Estrutura Molecular , Estereoisomerismo , Álcoois , Alquilação , Catálise
5.
Histochem Cell Biol ; 158(1): 5-13, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35469099

RESUMO

Paneth cells are antimicrobial peptide-secreting epithelial cells located at the bottom of the intestinal crypts of Lieberkühn. The crypts begin to form around postnatal day 7 (P7) mice, and Paneth cells usually appear within the first 2 weeks. Paneth cell dysfunction has been reported to correlate with Crohn's disease-like inflammation, showing narrow crypts or loss of crypt architecture in mice. The morphology of dysfunctional Paneth cells is similar to that of Paneth/goblet intermediate cells. However, it remains unclear whether the formation of the crypt is related to the maturation of Paneth cells. In this study, we investigated the histological changes including epigenetic modification in the mouse ileum postnatally and assessed the effect of the methyltransferase inhibitor on epithelium development using an organoid culture. The morphological and functional maturation of Paneth cells occurred in the first 2 weeks and was accompanied by histone H3 lysine 27 (H3K27) trimethylation, although significant differences in DNA methylation or other histone H3 trimethylation were not observed. Inhibition of H3K27 trimethylation in mouse ileal organoids suppressed crypt formation and Paneth cell maturation, until around P10. Overall, our findings show that post-transcriptional modification of histones, particularly H3K27 trimethylation, leads to the structural and functional maturation of Paneth cells during postnatal development.


Assuntos
Histonas , Celulas de Paneth , Animais , Diferenciação Celular , Epigênese Genética/genética , Mucosa Intestinal , Camundongos , Celulas de Paneth/patologia , Celulas de Paneth/fisiologia , Desmame
6.
J Phys Ther Sci ; 34(2): 85-91, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35221509

RESUMO

[Purpose] Patients with chronic unilateral vestibular hypofunction show decreased postural stability and low levels of physical activity and also experience much anxiety. Physical activity is known to improve these symptoms; however, no study has reported any positive effects of physical activity, such as symptom reduction or improvement in function in these patients. In this study, we investigated the role of a walking program in improvement of dizziness, anxiety, and postural stability in this patient population. [Participants and Methods] This study included 21 patients with unilateral vestibular hypofunction and chronic dizziness. Patients were instructed to walk 30 min daily for 3 months. Physical activity levels and questionnaires for clinical symptoms, anxiety, and postural stability were evaluated before and after intervention. [Results] We observed significant differences in the amount of moderate-to-vigorous physical activity, clinical symptoms, and self-perceived handicap before and after the intervention. Additionally, anxiety levels were significantly reduced and postural stability was significantly improved in these patients. [Conclusion] A walking program improved physical activity levels, clinical symptoms, and postural stability and reduced self-perceived handicap and anxiety in patients with chronic unilateral vestibular hypofunction. These results highlight the effectiveness of a walking program for these patients and emphasize its role as a complementary vestibular rehabilitation strategy.

7.
Immunity ; 36(5): 795-806, 2012 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-22633459

RESUMO

Primary resistance to pathogens is reliant on both basal and inducible immune defenses. To date, research has focused upon inducible innate immune responses. In contrast to resistance via cytokine induction, basal defense mechanisms are less evident. Here we showed that the antiviral protein kinase R (PKR) inhibited the key actin-modifying protein gelsolin to regulate actin dynamics and control cytoskeletal cellular functions under homeostatic conditions. Through this mechanism, PKR controlled fundamental innate immune, actin-dependent processes that included membrane ruffling and particle engulfment. Accordingly, PKR counteracted viral entry into the cell. These findings identify a layer of host resistance, showing that the regulation of actin-modifying proteins during the innate immune response bolsters first-line defense against intracellular pathogens and has a sustained effect on virus production. Moreover, these data provide proof of principle for a concept in which the cell cytoskeleton could be targeted to elicit broad antiviral protection.


Assuntos
Actinas/metabolismo , Gelsolina/metabolismo , Imunidade Inata/imunologia , eIF-2 Quinase/metabolismo , Actinas/imunologia , Linhagem Celular Transformada , Linhagem Celular Tumoral , Citocinas/imunologia , Citocinas/metabolismo , Citoesqueleto/imunologia , Citoesqueleto/metabolismo , Gelsolina/antagonistas & inibidores , Gelsolina/imunologia , Células HEK293 , Células HeLa , Humanos , Proteínas dos Microfilamentos/imunologia , Proteínas dos Microfilamentos/metabolismo , Domínios e Motivos de Interação entre Proteínas/imunologia , Vírus/imunologia , Vírus/metabolismo , eIF-2 Quinase/imunologia
8.
J Org Chem ; 85(18): 11592-11606, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32819091

RESUMO

2-Acylimidazoles are widely used as post-transformable carboxylic acid equivalents in chemoselective and enantioselective reactions. Their transformations, however, require pretreatment with highly reactive, toxic methylating reagents to facilitate C-C bond cleavage. Here, we demonstrate that such pretreatment can be avoided and the C-C bond cleaved under neutral conditions without the use of additional reagents or catalysts. The scope of the reaction, including the use of products reported in the literature as substrates, and some mechanistic insights are described.

9.
Immunol Invest ; 49(7): 698-710, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31821046

RESUMO

Although it is known that desert dust exacerbates allergic diseases, how it affects the onset of autoimmune diseases is unclear. No epidemiological investigations or animal experiments have been conducted so far to elucidate the effects of desert dust on autoimmune diseases. Here, we focused on particulate matter, such Asian sand dust (ASD) that has been known to cause adverse health effects in East Asian countries, and conducted animal experiments to examine how ASD influences type 1 diabetes (T1D), an autoimmune disease. An ASD suspension was intratracheally administered into NOD mice, which spontaneously develop T1D, for 4 times at 2-week intervals. Subsequently, the incidence of cyclophosphamide (CY)-induced diabetes was examined, which was then quantified using adoptive splenocyte-transfer assays. Kaplan-Meier curves of the cumulative T1D incidence were compared using the log-rank test, and unpaired two-tailed t tests were used for comparing the other data. We observed that ASD administration delayed T1D, and adoptive splenocytes derived from ASD-administered donor NOD mice also delayed the onset of T1D in recipient NOD mice. We further found that ASD increases concanavalin A-induced IFN-γ production and decreases regulatory T cells. Consequently, ASD suppresses the onset of T1D, activates spleen cells, and affects T-cell differentiation.


Assuntos
Ciclofosfamida/efeitos adversos , Diabetes Mellitus Tipo 1/etiologia , Poeira , Material Particulado , Areia , Animais , Citocinas/metabolismo , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Feminino , Imunomodulação , Ativação Linfocitária/imunologia , Linfócitos/imunologia , Linfócitos/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Material Particulado/efeitos adversos , Baço/citologia , Baço/imunologia , Baço/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo
10.
Dig Endosc ; 31(6): 653-661, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31120161

RESUMO

OBJECTIVE: To evaluate the usefulness of a training program on endoscopic head and neck surveillance for beginner endoscopists. METHODS: This prospective multicenter study included 13 beginner endoscopists from 10 institutions who received training in systematic observation techniques and diagnostic criteria, and the training involved hands-on learning. Between May 2016 and February 2017, enrolled patients with current or previously diagnosed esophageal squamous cell carcinomas underwent head and neck surveillance using narrow band imaging (NBI) endoscopy, and histologically confirmed head and neck squamous cell carcinoma (HNSCC) detection rates, endoscopic image quality, and examination times were compared before (group A) and after (group B) the training program. Maximum possible score for the endoscopic images was 30 points. RESULTS: A total of 330 patients, comprising 181 in group A and 149 in group B, were enrolled. Three patients with HNSCC were detected in group A (1.7%) and in group B (2.0%; P = 1.000). Mean ± standard deviation (SD) examination times were 157 ± 71 s and 174 ± 109 s in groups A and B, respectively, (P = 0.073). Mean ± SD scores of the endoscopic images were 25.04 ± 5.47 points and 27.01 ± 4.35 points in groups A and B, respectively, (P < 0.001). CONCLUSION: The HNSCC detection rate based on the use of NBI on patients with ESCC did not improve after the training program for beginner endoscopists; however, endoscopic image quality improved significantly after the training program.


Assuntos
Competência Clínica , Neoplasias Esofágicas/diagnóstico , Carcinoma de Células Escamosas do Esôfago/diagnóstico , Esofagoscopia/métodos , Gastroenterologia/educação , Aumento da Imagem/métodos , Imagem de Banda Estreita/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
11.
J Phys Ther Sci ; 31(1): 53-56, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30774205

RESUMO

[Purpose] Sports activity has been shown to improve postural stability and vestibular function in healthy older adults. The hypothesis was that healthy young adults undertaking sports activity will also have better postural stability and vestibular function compared with healthy young adults who do not undertake sports activity. The purpose of this study was to investigate the differences in postural stability and vestibular function between healthy young adults who undertake sports activity and those who do not undertake such activity. [Participants and Methods] Thirty-nine healthy young adults were recruited and divided into sports and non-sports groups on the basis of their response to a questionnaire concerning regular participation in sports activities over the past 12 months. In both groups, postural stability was measured during quiet standing and standing during head rotation, and dynamic visual acuity was assessed during head rotation. [Results] The results showed significant differences in postural stability during head rotation and dynamic visual acuity between the two groups, whereas no significant differences were found in postural stability during quiet standing. [Conclusion] The results suggest that healthy young adults who undertake sports activity have better postural stability during head rotation and better dynamic visual acuity. The causal effect of these differences is not clear and further investigation is warranted.

12.
Chemistry ; 24(57): 15211-15214, 2018 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-30098059

RESUMO

Although BINOL-derived phosphoric acids are among the most widely used chiral Brønsted acid organocatalysts, their structures are mostly limited to 3,3'-disubstituted ones and simple 3-mono-substituted ones without any polar functionalities on the 3-substituent have not been used in highly enantioselective reactions. This work reports such 3-mono-substituted analogues as effective organocatalysts in direct highly enantioselective Friedel-Crafts-type alkylation of N-unprotected α-ketiminoester. The origin of the observed high enantioselectivity with the 3-mono-substituted catalyst is also discussed.

13.
Gastrointest Endosc ; 87(5): 1231-1240, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29233673

RESUMO

BACKGROUND AND AIMS: The aim of this study was to clarify whether dental floss clip (DFC) traction improves the technical outcomes of endoscopic submucosal dissection (ESD). METHODS: A superiority, randomized control trial was conducted at 14 institutions across Japan. Patients with single gastric neoplasm meeting the indications of the Japanese guidelines for gastric treatment were enrolled and assigned to receive conventional ESD or DFC traction-assisted ESD (DFC-ESD). Randomization was performed according to a computer-generated random sequence with stratification by institution, tumor location, tumor size, and operator experience. The primary endpoint was ESD procedure time, defined as the time from the start of the submucosal injection to the end of the tumor removal procedure. RESULTS: Between July 2015 and September 2016, 640 patients underwent randomization. Of these, 316 patients who underwent conventional ESD and 319 patients who underwent DFC-ESD were included in our analysis. The mean ESD procedure time was 60.7 and 58.1 minutes for conventional ESD and DFC-ESD, respectively (P = .45). Perforation was less frequent in the DFC-ESD group (2.2% vs .3%, P = .04). For lesions located in the greater curvature of the upper or middle stomach, the mean procedure time was significantly shorter in the DFC-ESD group (104.1 vs 57.2 minutes, P = .01). CONCLUSIONS: Our findings suggest that DFC-ESD does not result in shorter procedure time in the overall patient population, but it can reduce the risk of perforation. When selectively applied to lesions located in the greater curvature of the upper or middle stomach, DFC-ESD provides a remarkable reduction in procedure time.


Assuntos
Adenocarcinoma/cirurgia , Adenoma/cirurgia , Ressecção Endoscópica de Mucosa/métodos , Neoplasias Gástricas/cirurgia , Adenocarcinoma/patologia , Adenoma/patologia , Idoso , Estudos de Equivalência como Asunto , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/patologia , Carga Tumoral
14.
Chemistry ; 23(67): 17022-17028, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28950035

RESUMO

Direct catalytic C-C bond-forming addition to N-unprotected ketimines is an efficient and straightforward method of synthesizing N-unprotected tetrasubstituted amines that eliminates prior protection/deprotection steps and allows facile transformation of the products. Despite its advantages, however, N-unprotected ketimines have difficulties in C-C bond-forming reactions, and only a limited number of reactions and substrates are reported compared with their N-protected counterparts. Herein we report that N-unprotected trifluoromethyl ketimines are effective for C-C bond-forming reactions using Mannich-type reactions as a model case. We demonstrate that Lewis acid catalysis was effective for promoting reactions with various N-unprotected trifluoromethyl ketimines, and thiourea organocatalysis was effective for promoting highly enantioselective reactions with various carbonyl nucleophiles, providing direct access to various N-unprotected α- and/or ß-tetrasubstituted amino acid esters. Furthermore, direct construction of vicinal tetrasubstituted chiral carbon stereocenters was achieved for the first time in a highly enantio- and diastereoselective manner. These results demonstrate the potential of N-unprotected ketimines as substrates applicable to many other addition reactions.

15.
Gastrointest Endosc ; 86(3): 492-499, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28137598

RESUMO

BACKGROUND AND AIMS: Biodegradable stents are reportedly effective for refractory benign esophageal strictures; however, little is known about their use in patients with refractory stricture after endoscopic submucosal dissection (ESD) or chemoradiotherapy (CRT) for esophageal cancer. This study aimed to evaluate the effectiveness of biodegradable stents for these patients. METHODS: Patients with refractory benign esophageal stricture with a dysphagia score (DS) of 2 or worse and for whom the passage of a standard size endoscope was not possible were eligible. The primary endpoint was the proportion of those who improved their DSs (% DS improved) at 12 weeks after stent placement, and the secondary endpoints were the proportion of those who improved their DSs at 24 weeks, dysphagia-free survival (DFS), and adverse events. RESULTS: Eighteen patients (men:women, 15:3; median age, 72 years; range, 53-80) were enrolled. Twelve patients improved their DS at 12 weeks (% DS improved, 66.7%; 90% CI, 44.6%-84.4%). Also, 8 of 11 patients (72.7%) after esophagectomy, 4 of 6 patients (66.7%) after ESD, and 3 of 4 patients (75%) after CRT improved at 12 weeks. Three patients who were treated with esophagectomy maintained their DS improvement at 24 weeks (% DS improved, 16.7%; 95% CI, 3.6%-41.4%). The median DFS was 14.1 weeks (95% CI, 13.0-19.0). One patient who had ESD and CRT developed an esophagobronchial fistula 3 months after stent placement. CONCLUSIONS: Biodegradable stents are effective and tolerable for refractory benign esophageal strictures after treatment for esophageal cancer; however, long-term efficacy was limited, especially after ESD or CRT. (Clinical trial registration number: UMIN000008054.).


Assuntos
Implantes Absorvíveis , Neoplasias Esofágicas/terapia , Estenose Esofágica/cirurgia , Complicações Pós-Operatórias/cirurgia , Stents , Idoso , Idoso de 80 Anos ou mais , Fístula Brônquica , Quimiorradioterapia/efeitos adversos , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/fisiopatologia , Ressecção Endoscópica de Mucosa/efeitos adversos , Fístula Esofágica , Estenose Esofágica/etiologia , Estenose Esofágica/fisiopatologia , Esofagectomia/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/fisiopatologia , Estudos Prospectivos , Resultado do Tratamento
16.
Chem Pharm Bull (Tokyo) ; 65(11): 1089-1092, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29093297

RESUMO

This note describes the construction of tetrasubstituted carbon stereocenters via palladium-catalyzed allylation of sp3 C-H bonds of 2,2,2-trifluoroethylamine derivatives. The presence of 2-pyridyl group of the imines derived from 1-substituted-2,2,2-trifluoroethylamine was key to promoting the reaction efficiently, allowing an access to a variety of 1-allylated 2,2,2-trifluoroethylamine derivatives with tetrasubstituted carbon stereocenters.


Assuntos
Compostos Alílicos/síntese química , Etilaminas/síntese química , Paládio/química , Compostos Alílicos/química , Catálise , Etilaminas/química , Estrutura Molecular
17.
Biochim Biophys Acta ; 1850(9): 1676-84, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25960391

RESUMO

BACKGROUND: The mitotic spindles are among the most successful targets of anti-cancer chemotherapy, and they still hold promise as targets for novel drugs. The anti-mitotic drugs in current clinical use, including taxanes, epothilones, vinca alkaloids, and halichondrins, are all microtubule-targeting agents. Although these drugs are effective for cancer chemotherapy, they have some critical problems; e.g., neurotoxicity caused by damage to neuronal microtubules, as well as innate or acquired drug resistance. To overcome these problems, a great deal of effort has been expended on development of novel anti-mitotics. METHODS: We identified novel microtubule-targeting agents with carbazole and benzohydrazide structures: N'-[(9-ethyl-9H-carbazol-3-yl)methylene]-2-methylbenzohydrazide (code number HND-007) and its related compounds. We investigated their activities against cancer cells using various methods including cell growth assay, immunofluorescence analysis, cell cycle analysis, tubulin polymerization assay, and tumor inhibition assay in nude mice. RESULTS: HND-007 inhibits tubulin polymerization in vitro and blocks microtubule formation and centrosome separation in cancer cells. Consequently, it suppresses the growth of various cancer cell lines, with IC50 values in the range 1.3-4.6µM. In addition, HND-007 can inhibit the growth of taxane-resistant cancer cells that overexpress P-glycoprotein. Finally, HND-007 can inhibit HeLa cell tumor growth in nude mice. CONCLUSIONS AND GENERAL SIGNIFICANCE: Taken together, these findings suggest that HND-007 is a promising lead compound for development of novel anti-mitotic, anti-microtubule chemotherapeutic agents.


Assuntos
Antimitóticos/farmacologia , Antineoplásicos/farmacologia , Carbazóis/farmacologia , Microtúbulos/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Moduladores de Tubulina/farmacologia
18.
J Am Chem Soc ; 138(19): 6194-203, 2016 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-27092817

RESUMO

Mechanistic studies and expansion of the substrate scope of direct enantioselective alkynylation of α-ketiminoesters catalyzed by adaptable (phebox)rhodium(III) complexes are described. The mechanistic studies revealed that less acidic alkyne rather than more acidic acetic acid acted as a proton source in the catalytic cycle, and the generation of more active (acetato-κ(2)O,O')(alkynyl)(phebox)rhodium(III) complexes from the starting (diacetato)rhodium(III) complexes limited the overall reactivity of the reaction. These findings, as well as facile exchange of the alkynyl ligand on the (alkynyl)rhodium(III) complexes led us to use (acetato-κ(2)O,O')(trimethylsilylethynyl)(phebox)rhodium(III) complexes as a general precatalyst for various (alkynyl)rhodium(III) complexes. Use of the (trimethylsilylethynyl)rhodium(III) complexes as precatalysts enhanced the catalytic performance of the reactions with an α-ketiminoester derived from ethyl trifluoropyruvate at a catalyst loading as low as 0.5 mol % and expanded the substrate scope to unprecedented α-ketiminophosphonate and cyclic N-sulfonyl α-ketiminoesters.

19.
Lab Invest ; 96(10): 1050-62, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27617401

RESUMO

Osteosarcoma is the most frequent primary bone tumor. Serine/threonine protein phosphatase 2A (PP2A) participates in regulating many important physiological processes, such as cell cycle, growth, apoptosis, and signal transduction. In this study, we examined the expression and function of PP2A Cα in osteosarcoma cells. PP2A Cα expression was expected to be higher in malignant osteosarcoma tissues. PP2A Cα expression level and PP2A activity was higher in malignant osteosarcoma LM8 cells compared with that in primary osteoblasts and in the osteoblast-like cell line MC3T3-E1. Okadaic acid, an inhibitor of PP2A, reduced cell viability and induced apoptosis in LM8 cells. PP2A Cα-knockdown LM8 cells (shPP2A) exhibited less striking filopodial and lamellipodial structures than that in original LM8 cells. Focal adhesion kinase phosphorylation and NF-κB activity decreased in shPP2A-treated cells. Sensitivity to serum deprivation-induced apoptosis increased in shPP2A-treated cells, accompanied by a lower expression level of anti-apoptotic BCL-2 in these cells. Reduction of PP2A Cα resulted in a decrease in the migration ability of LM8 cells in vitro. Reduction in PP2A Cα levels in vivo suppressed proliferation and metastasis in LM8 cells. PP2A Cα expression was also higher in human osteosarcoma MG63 and SaOS-2 cells than that in primary osteoblasts and MC3T3-E1 cells, and reduction in PP2A Cα levels suppressed the cell proliferation rate and migration ability of MG63 cells. These results indicate that PP2A Cα has a critical role in the proliferation and metastasis of osteosarcoma cells; therefore, its inhibition could potentially suppress the malignancy of osteosarcoma cells.


Assuntos
Osteossarcoma/enzimologia , Proteína Fosfatase 2/metabolismo , Animais , Apoptose , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Forma Celular , Camundongos , Metástase Neoplásica
20.
Biochem Biophys Res Commun ; 478(1): 53-59, 2016 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-27457803

RESUMO

Microglia are derived from myelogenous cells and contribute to immunological and inflammatory responses in central nervous system. They play important roles not only in infectious diseases and inflammation after stroke, but also in psychiatric diseases such as schizophrenia. While recent studies suggest the significances of serum- and glucocorticoid-inducible kinases (SGKs) in other immune cells such as macrophages, T cells and dendritic cells, their role in microglia remains unknown. Here we, for the first time, report that SGK1 and SGK3 are expressed in multiple microglial cell lines. An SGK inhibitor, gsk650394, inhibits cell viability. In addition, lipopolysaccharide-induced expression of inflammatory regulators iNOS and TNFα was enhanced by gsk650394. Furthermore, translocation of NF-κB was enhanced by gsk650394. Taken together, these findings suggest that SGKs may play an important role in regulating microglial viability and inflammatory responses.


Assuntos
Proteínas Imediatamente Precoces/análise , Microglia/enzimologia , Proteínas Serina-Treonina Quinases/análise , Animais , Sobrevivência Celular/efeitos dos fármacos , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/enzimologia , Córtex Cerebral/imunologia , Proteínas Imediatamente Precoces/imunologia , Inflamação/tratamento farmacológico , Inflamação/enzimologia , Inflamação/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/citologia , Microglia/efeitos dos fármacos , Microglia/imunologia , NF-kappa B/imunologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/imunologia , Transdução de Sinais
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