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1.
J Steroid Biochem Mol Biol ; 188: 124-130, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30611910

RESUMO

Bisphosphonates like risedronate inhibit osteoclast-mediated bone resorption and are therefore used in the prevention and treatment of osteoporosis. Also vitamin D3 and calcium supplementation is commonly used in the prevention or treatment of osteoporosis. Combined therapy of risedronate with 1,25(OH)2D3, the active metabolite of vitamin D3, may be advantageous over the use of either monotherapy, but bears a risk of causing hypercalcemia thereby decreasing the therapeutic window for osteoporosis treatment. In this study, we evaluated the effect on bone mass of the combination of risedronate with the 17-methyl 19-nor five-membered D-ring vitamin D3 analog WY 1048 in a mouse ovariectomy model for postmenopausal osteoporosis. Ovariectomy-induced bone loss was restored by administration of risedronate or a combination of risedronate with 1,25(OH)2D3. However, the combination of WY 1048 with risedronate induced an even higher increase on total body and spine bone mineral density and on trabecular and cortical bone mass. Our data indicate that combination therapy of risedronate with WY 1048 was superior in restoring and improving bone mass over a combination of risedronate with 1,25(OH)2D3 with minimal calcemic side effects.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Colecalciferol/uso terapêutico , Osteoporose Pós-Menopausa/tratamento farmacológico , Ácido Risedrônico/uso terapêutico , Vitaminas/uso terapêutico , Animais , Densidade Óssea/efeitos dos fármacos , Colecalciferol/análogos & derivados , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Osteoporose Pós-Menopausa/patologia , Vitaminas/química
2.
Eur J Med Chem ; 162: 495-506, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30471551

RESUMO

The Hedgehog (Hh) pathway is a developmental pathway with therapeutic potential as a target for a variety of cancers. In recent years, several vitamin D-based compounds have been identified as potent inhibitors of Hh signaling. These analogues contain aromatic phenol A-ring mimics coupled to the CD-ring side chain of vitamin D3 through modified seco-B regions. To continue structure-activity relationship studies on this class of Hh pathway inhibitors, multiple series of vitamin D-based analogues that contain an amine-based seco-B tether and/or incorporate a hydroxyl moiety on C-25 were designed and synthesized. These compounds were evaluated in multiple cell lines for their anti-Hh activity, and we identify analogues 16, 21, 22 as potent vitamin D-based Hh inhibitors (IC50 values of 110-340 nM). We also performed a series of mechanism of action studies in knockout cell lines to further explore whether these analogues inhibit the Hh pathway through a known Hh pathway component or the vitamin D receptor. While the specific cellular target that mediates these effects remains elusive, our studies suggest multiple cellular targets may mediate the anti-Hh activity of this scaffold.


Assuntos
Colecalciferol/síntese química , Proteínas Hedgehog/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular , Colecalciferol/análogos & derivados , Colecalciferol/farmacologia , Técnicas de Inativação de Genes , Humanos , Concentração Inibidora 50 , Receptores de Calcitriol/metabolismo , Relação Estrutura-Atividade , Proteína GLI1 em Dedos de Zinco/metabolismo
3.
Anticancer Res ; 38(7): 3879-3887, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29970508

RESUMO

BACKGROUND: Breast cancer ranks second in the list of cancer-related deaths for women. Even under multidisciplinary treatment, 25-50% of patients with breast cancer still ultimately develop metastasis, leading to poor prognosis. In addition to inducing angiogenesis, vascular endothelial growth factor-A (VEGF-A) is believed to directly increase cancer cell metastatic potential and overexpression of VEGF-A is associated with higher invasiveness of breast cancer. 1α,25(OH)2D3, the active form of vitamin D, and its analogs have been widely applied as anticancer agents in the past. MATERIAL AND METHODS: Western blot, migration and invasion assays, enzyme-linked immunosorbent assay, and immunofluorescent stain were applied in this study. RESULT: VEGF-A increased cell migration and invasion in estrogen receptor-positive (ER+) breast cancer MCF-7 cells. VEGF-A induced an autocrine loop in MCF-7 cells as VEGF-A treatment increased both VEGF-A expression and secretion. The expression of VEGF receptor type 2 (VEGFR2) and neuropilin 1 was also up-regulated by VEGF-A in MCF-7 cells. In addition, F-actin synthesis and LIM domain kinase 1 (LIMK-1) phosphorylation were increased by VEGF-A. VEGF-A also increased ß-catenin expression and nuclear translocation of both ß-catenin and nuclear factor-ĸB (NF-ĸB), indicating increased ß-catenin and NF-ĸB activity. 1α,25(OH)2D3 and MART-10, an analog of 1α,25(OH)2D3, effectively repressed VEGF-A-induced MCF-7 cell migration and invasion and other VEGF-A-induced effects on MCF-7 cells, with MART-10 being more potent than 1α,25(OH)2D3 Conclusion: MART-10 can be deemed as a promising agent for prevention and treatment of metastasis of ER+ breast cancer with VEGF-A overexpression.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Colecalciferol/análogos & derivados , Receptores Estrogênicos/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Western Blotting , Neoplasias da Mama/metabolismo , Colecalciferol/farmacologia , Ensaio de Imunoadsorção Enzimática , Feminino , Imunofluorescência , Humanos , Quinases Lim/metabolismo , Células MCF-7 , Metástase Neoplásica , Neuropilina-1 , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
4.
Org Biomol Chem ; 16(14): 2448-2455, 2018 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-29560490

RESUMO

Both 2α- and 2ß-hydroxypropyl substituted 14-epi-1α,25-dihydroxy-19-nortachysterols were synthesized to study the human vitamin D receptor (hVDR) binding affinity, binding configurations, and interactions with amino acid residues in the ligand binding domain of hVDR by X-ray co-crystallographic analysis. In conjunction with our previous results on 14-epi-19-nortachysterol, 2-methylidene-, 2α-methyl-, 2ß-methyl, and 2α-hydroxypropoxy-14-epi-19-nortachysterol, we propose a variety of effects of substitution at the C2 position in the 14-epi-19-nortachysterol skeleton on biological activities.


Assuntos
Colecalciferol/análogos & derivados , Receptores de Calcitriol/química , Sítios de Ligação , Colecalciferol/síntese química , Colecalciferol/química , Cristalografia por Raios X , Humanos , Ligantes , Estrutura Molecular
5.
J Steroid Biochem Mol Biol ; 181: 1-10, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29452159

RESUMO

Prolonged exposure of the skin to UV radiation causes previtamin D3, the initial photoproduct formed by opening of the B ring of 7-dehydrocholesterol, to undergo a second photochemical reaction where the B-ring is reformed giving lumisterol3 (L3), a stereoisomer of 7-dehydrocholesterol. L3 was believed to be an inactive photoproduct of excessive UV radiation whose formation prevents excessive vitamin D production. Recently, we reported that L3 is present in serum and that CYP11A1 can act on L3 producing monohydroxy- and dihydroxy-metabolites which inhibit skin cell proliferation similarly to 1α,25-dihydroxyvitamin D3. In this study we tested the ability of human CYP27A1 to hydroxylate L3. L3 was metabolized by purified CYP27A1 to 3 major products identified as 25-hydroxyL3, (25R)-27-hydroxyL3 and (25S)-27-hydroxyL3, by NMR. These three products were also seen when mouse liver mitochondria containing CYP27A1 were incubated with L3. The requirement for CYP27A1 for their formation by mitochondria was confirmed by the inhibition of their synthesis by 5ß-cholestane-3α,7α,12α-triol, an intermediate in bile acid synthesis which serves as an efficient competitive substrate for CYP27A1. CYP27A1 displayed a high kcat for the metabolism of L3 (76 mol product/min/mol CYP27A1) and a catalytic efficiency (kcat/Km) that was 260-fold higher than that for vitamin D3. The CYP27A1-derived hydroxy-derivatives inhibited the proliferation of cultured human melanoma cells and colony formation with IC50 values in the nM range. Thus, L3 is metabolized efficiently by CYP27A1 with hydroxylation at C25 or C27 producing metabolites potent in their ability to inhibit melanoma cell proliferation, supporting that L3 is a prohormone which can be activated by CYP-dependent hydroxylations.


Assuntos
Colecalciferol/análogos & derivados , Colecalciferol/metabolismo , Colestanotriol 26-Mono-Oxigenase/metabolismo , Ergosterol/metabolismo , Mitocôndrias Hepáticas/metabolismo , Animais , Hidroxilação , Camundongos , Estereoisomerismo
6.
ChemMedChem ; 13(7): 748-753, 2018 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-29409113

RESUMO

The Hedgehog (Hh) signaling pathway is critical for embryonic patterning and postembryonic tissue regeneration. Constitutive pathway activation has also been linked to human malignancies such as basal cell carcinoma (BCC) and medulloblastoma; therefore, multiple small-molecule scaffolds that inhibit Hh signaling are in development. Previously, Grundmann's alcohol, also known as the "northern region" of vitamin D3 (VD3), has been identified as a moderate Hh pathway inhibitor. In this study, isomers of Grundmann's alcohol with different orientations of the C4 hydroxy group and C3α proton were investigated to determine the optimal configuration for this hexahydroindane scaffold with respect to Hh inhibition. A series of analogues containing Grundmann's alcohol linked to a substituted phenyl or benzyl ring through an ether or thioether linker were synthesized and evaluated for their anti-Hh activity. Of these, analogue 17 ((1R,3aR,4R,7aR)-1-[(R)-1,5-dimethylhexyl]-4-(4-aminophenoxy)-7a-methyloctahydro-1H-indene) demonstrated potent anti-Hh activity in Hh-dependent BCC cells and did not activate canonical vitamin D receptor signaling, demonstrating its selective nature for the Hh signaling pathway.


Assuntos
Colecalciferol/análogos & derivados , Colecalciferol/farmacologia , Éteres/farmacologia , Proteínas Hedgehog/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Sulfetos/farmacologia , Animais , Linhagem Celular Tumoral , Colecalciferol/síntese química , Éteres/síntese química , Éteres/química , Camundongos , Estrutura Molecular , Estereoisomerismo , Relação Estrutura-Atividade , Sulfetos/síntese química , Sulfetos/química
7.
Int J Oncol ; 52(2): 337-366, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29345296

RESUMO

Numerous in vitro and in vivo studies have demonstrated that calcitriol [1,25(OH)2D3] and different vitamin D analogs possess antineoplastic activity, regulating proliferation, differentiation and apoptosis, as well as angiogenesis. Vitamin D compounds have been shown to exert synergistic effects when used in combination with different agents used in anticancer therapies in different cancer models. The aim of this study was to evaluate the mechanisms of the cooperation of the vitamin D compounds [1,24(OH)2D3 (PRI­2191) and 1,25(OH)2D3] with tyrosine kinase inhibitors (imatinib and sunitinib) together with cytostatics (cisplatin and docetaxel) in an A549 non-small cell lung cancer model. The cytotoxic effects of the test compounds used in different combinations were evaluated on A549 lung cancer cells, as well as on human lung microvascular endothelial cells (HLMECs). The effects of such combinations on the cell cycle and cell death were also determined. In addition, changes in the expression of proteins involved in cell cycle regulation, angiogenesis and the action of vitamin D were analyzed. Moreover, the effects of 1,24(OH)2D3 on the anticancer activity of sunitinib and sunitinib in combination with docetaxel were examined in an A549 lung cancer model in vivo. Experiments aiming at evaluating the cytotoxicity of the combinations of the test agents revealed that imatinib and sunitinib together with cisplatin or docetaxel exerted potent anti-proliferative effects in vitro on A549 lung cancer cells and in HLMECs; however, 1,24(OH)2D3 and 1,25(OH)2D3 enhanced the cytotoxic effects only in the endothelial cells. Among the test agents, sunitinib and cisplatin decreased the secretion of vascular endothelial growth factor (VEGF)­A from the A549 lung cancer cells. The decrease in the VEGF­A level following incubation with cisplatin correlated with a higher p53 protein expression, while no such correlation was observed following treatment of the A549 cells with sunitinib. Sunitinib together with docetaxel and 1,24(OH)2D3 exhibited a more potent anticancer activity in the A549 lung cancer model compared to double combinations and to treatment with the compounds alone. The observed anticancer activity may be the result of the influence of the test agents on the process of tumor angiogenesis, for example, through the downregulation of VEGF­A expression in tumor and also on the induction of cell death inside the tumor.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Colecalciferol/análogos & derivados , Citostáticos/farmacologia , Di-Hidroxicolecalciferóis/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Animais , Becaplermina , Calcitriol/farmacologia , Carcinoma Pulmonar de Células não Pequenas/irrigação sanguínea , Carcinoma Pulmonar de Células não Pequenas/patologia , Cisplatino/administração & dosagem , Citostáticos/administração & dosagem , Docetaxel , Feminino , Humanos , Mesilato de Imatinib/administração & dosagem , Indóis/administração & dosagem , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/patologia , Camundongos SCID , Proteínas Proto-Oncogênicas c-sis/metabolismo , Pirróis/administração & dosagem , Sunitinibe , Taxoides/administração & dosagem , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Chemistry ; 24(13): 3314-3320, 2018 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-29239492

RESUMO

We describe an efficient convergent synthesis of vitamin D3 metabolites and analogues. The synthetic strategy relies on a tandem Pd-catalyzed A-ring closure and Suzuki-Miyaura coupling to the CD-side chain component to set directly the vitamin D triene system under protic conditions. This strategy enables rapid access to vitamin D3 and 3-epi-vitamin D3 metabolites and analogues modified at the side chain for biological evaluation and structural and metabolic studies.


Assuntos
Colecalciferol/análogos & derivados , Colecalciferol/síntese química , Paládio/química , Catálise , Colecalciferol/química , Estrutura Molecular , Solventes/química , Estereoisomerismo , Relação Estrutura-Atividade
9.
Int J Mol Sci ; 19(1)2017 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-29283379

RESUMO

The development of radiation countermeasures for acute radiation syndrome (ARS) has been underway for the past six decades, leading to the identification of multiple classes of radiation countermeasures. However, to date, only two growth factors (Neupogen and Neulasta) have been approved by the United States Food and Drug Administration (US FDA) for the mitigation of hematopoietic acute radiation syndrome (H-ARS). No radioprotector for ARS has been approved by the FDA yet. Gamma-tocotrienol (GT3) has been demonstrated to have radioprotective efficacy in murine as well as nonhuman primate (NHP) models. Currently, GT3 is under advanced development as a radioprotector that can be administered prior to radiation exposure. We are studying this agent for its safety profile and efficacy using the NHP model. In this study, we analyzed global metabolomic and lipidomic changes using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry (QTOF-MS) in serum samples of NHPs administered GT3. Our study, using 12 NHPs, demonstrates that alterations in metabolites manifest only 24 h after GT3 administration. Furthermore, metabolic changes are associated with transient increase in the bioavailability of antioxidants, including lactic acid and cholic acid and anti-inflammatory metabolites 3 deoxyvitamin D3, and docosahexaenoic acid. Taken together, our results show that the administration of GT3 to NHPs causes metabolic shifts that would provide an overall advantage to combat radiation injury. This initial assessment also highlights the utility of metabolomics and lipidomics to determine the underlying physiological mechanisms involved in the radioprotective efficacy of GT3.


Assuntos
Cromanos/farmacocinética , Metabolismo dos Lipídeos/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Protetores contra Radiação/farmacocinética , Vitamina E/análogos & derivados , Síndrome Aguda da Radiação/sangue , Síndrome Aguda da Radiação/prevenção & controle , Animais , Antioxidantes/metabolismo , Disponibilidade Biológica , Colecalciferol/análogos & derivados , Colecalciferol/sangue , Ácido Cólico/sangue , Cromanos/sangue , Ácidos Docosa-Hexaenoicos/sangue , Feminino , Humanos , Ácido Láctico/sangue , Macaca mulatta , Masculino , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Vitamina E/sangue , Vitamina E/farmacocinética
10.
Anticancer Res ; 37(11): 6215-6221, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29061804

RESUMO

AIMS: Pancreatic neuroendocrine tumors (PanNETs) are usually diagnosed in an advanced stage. Most patients with PanNETs die of metastasis. Vascular endothelial growth factor-A (VEGF-A) is a strong stimulator of angiogenesis and tumor metastasis. We aimed to investigate the effect of MART-10 [19-nor-2α-(3-hydroxypropyl)-1α,25(OH)2D3], a 1α,25-dihydroxy-vitamin D3 (1α,25(OH)2D3) analog, on PanNET cell metastasis after VEGF-A stimulation. MATERIALS AND METHODS: Migration and invasion assays, western blot, and immunofluorescent staining were applied in this study. RESULTS: VEGF-A increased PanNET cell migration and invasion, which was attenuated by 1α,25(OH)2D3 and MART-10. VEGF-A treatment stimulated epithelial-mesenchymal transition (EMT) of PanNET cells. During this process, expression of snail family transcriptional repressor 1 and 2, and fibronectin was up-regulated. 1α,25(OH)2D3 and MART-10 counteracted VEGF-A-induced EMT. In addition, expression of neuropilin 1, a key protein in VEGF-A signaling, was down-regulated by 1α,25(OH)2D3 and MART-10. Furthermore, synthesis of F-actin was increased by VEGF-A and reduced by 1α,25(OH)2D3 and MART-10. CONCLUSION: Our data indicate that MART-10 could be deemed a promising drug for PanNET treatment.


Assuntos
Colecalciferol/análogos & derivados , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Insulinoma/tratamento farmacológico , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Colecalciferol/farmacologia , Insulinoma/metabolismo , Insulinoma/secundário , Ratos , Células Tumorais Cultivadas
11.
Bioorg Med Chem Lett ; 27(17): 4011-4014, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28780161

RESUMO

Previous structure-activity relationship studies have provided potent and selective analogues of vitamin D3 as inhibitors of the Hedgehog (Hh) signaling pathway. These analogues contain both modified A- and seco-B ring motifs, and have been evaluated for anticancer therapeutic potential. To continue our studies on this scaffold, a new series of compounds were synthesized to explore additional interactions and spatial constraints. These compounds incorporate functional groups of varying size and hydrophobicity at the C-11 position. While large hydrophobic moieties (9c-e) resulted in significant loss of Hh inhibition, smaller or more flexible moieties (9a, 11) maintain anti-Hh activity. These results call for additional and continued studies to identify the binding pocket to better understand these structure-activity relationships.


Assuntos
Colecalciferol/farmacologia , Proteínas Hedgehog/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular , Colecalciferol/análogos & derivados , Colecalciferol/síntese química , Relação Dose-Resposta a Droga , Proteínas Hedgehog/metabolismo , Camundongos , Estrutura Molecular , Relação Estrutura-Atividade
12.
Calcif Tissue Int ; 101(4): 433-444, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28624935

RESUMO

Diabetes mellitus is known to adversely affect the bones and be associated with increased fracture risk. We examined whether eldecalcitol (ELD), an active vitamin D3 derivative, could inhibit the diabetic bone loss in streptozotocin-induced type I diabetic rats. ELD (10, 20, or 40 ng/kg), alfacalcidol (ALF; 25, 50, or 100 ng/kg), or vehicle was administered 5 times per week for 12 weeks from 1 week after diabetes induction. Normal control rats received the vehicle. Bone turnover markers, bone mineral density (BMD), and biomechanical strength of the lumbar spine and femur were measured, and bone histomorphometry was performed. Content of advanced glycation end products (AGEs) in the femoral shaft was also determined. In diabetic rats, serum osteocalcin (OC) concentration was lower and urinary excretion of deoxypyridinoline (DPD) tended to be higher than in normal rats. Areal BMD and maximum load of the lumbar vertebrae and femoral shaft were lower in diabetic rats than in normal rats. All doses of ELD and the highest dose of ALF reduced urinary DPD excretion, but had no effect on serum OC. The 20 and 40 ng/kg doses of ELD prevented decreases in BMD and the highest dose of ELD prevented the reduction in maximum load of the lumbar vertebrae, while ALF did not change these parameters. ELD and ALF did not affect areal BMD or biomechanical strength of the femoral shaft. In diabetic rats, bone volume and trabecular thickness in the trabecular bone of the lumbar vertebrae decreased and trabecular separation increased compared to normal rats. ELD and ALF prevented diabetes-induced deterioration of trabecular microstructure. AGE content in the femoral cortical bone increased in the diabetic rats, and ELD and ALF did not change AGE content compared to the diabetic rats. These results indicated that ELD suppressed bone resorption and prevented trabecular bone loss and deterioration of trabecular microstructure, resulting in prevention of reduction in biomechanical strength in type I diabetic rats.


Assuntos
Conservadores da Densidade Óssea/farmacologia , Densidade Óssea/efeitos dos fármacos , Diabetes Mellitus Experimental/complicações , Vitamina D/análogos & derivados , Animais , Reabsorção Óssea , Colecalciferol/análogos & derivados , Masculino , Ratos , Ratos Sprague-Dawley , Vitamina D/farmacologia
13.
Sci Rep ; 7: 43773, 2017 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-28256614

RESUMO

Cholangiocarcinoma (CCA) is a devastating disease due to no effective treatments available. Since the non-mineral functions of vitamin D emerges, 1α,25(OH)2D3, the active form of vitamin D, has been applied in anti-cancer researches. In this study, we demonstrated that both the 1α,25(OH)2D3 analog, MART-10, and 1α,25(OH)2D3 possessed anti-growth effect on human CCA cells with MART-10 much more potent than 1α,25(OH)2D3. The growth inhibition of both drugs were mediated by induction of G0/G1 cell cycle arrest through upregulation of p27 and downregulation of CDK4, CDK6, and cyclin D3. Human neutrophil gelatinase associated lipocalin (NGAL) was found to be involved in 1α,25(OH)2D3 and MART-10 meditated growth inhibition for CCA as knockdown of NGAL decreased Ki-67 expression in SNU308 cells and rendered SNU308 cells less responsive to 1α,25(OH)2D3 and MART-10 treatment. Vitamin D receptor (VDR) knockdown partly abolished MART-10-induced inhibition of NGAL and cell growth in SNU308 cells. The xenograft animal study demonstrated MART-10 could effectively repressed CCA growth in vivo without inducing obvious side effects. The IHC examination of human CCA specimen for VDR revealed that higher VDR expression was linked with better prognosis. Collectively, our results suggest that MART-10 could be a promising regimen for CCA treatment.


Assuntos
Neoplasias dos Ductos Biliares/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Colangiocarcinoma/tratamento farmacológico , Colecalciferol/análogos & derivados , Receptores de Calcitriol/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Idoso , Animais , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/metabolismo , Linhagem Celular Tumoral , Colangiocarcinoma/genética , Colangiocarcinoma/metabolismo , Colecalciferol/farmacologia , Feminino , Técnicas de Silenciamento de Genes , Humanos , Estimativa de Kaplan-Meier , Masculino , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Pessoa de Meia-Idade , Prognóstico , Receptores de Calcitriol/genética
14.
J Phys Chem A ; 121(12): 2331-2342, 2017 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-28234492

RESUMO

We present a comparative study of the photoisomerizations of lumisterol (Lumi), previtamin (Pre), and provitamin D3 (Pro) to tachysterol (Tachy) at 77 K in EPA (5:5:2 ether, isopentane, and ethanol by volume) glass. Fluorescence, fluorescence excitation, and UV spectra, measured in the course of these reactions, were analyzed using singular value decomposition with self-modeling (SVD-SM). This represents an extension of previous work that led to the conclusion that in the EPA glass Pre exists as an s-cis,s-cis-conformer (cZc-Pre) which gives, exclusively, an unstable s-cis,s-cis-conformer of Tachy (cEc-Tachy) and Pro gives mainly the tEc-Tachy, that corresponds to a stable s-trans,s-cis-conformer. ( Redwood , C. ; et al. J. Phys. Chem. Lett. 2013 , 4 , 716 - 721 . ) The surprising result was that the major Pre photoproduct from Pro also has a tZc-Pre conformation instead of the expected cZc-Pre conformation. Accordingly, the Pre to Tachy cis-trans photoisomerization proceeds via a conformer specific one-bond-twist (OBT) process as proposed by Havinga ( Maessen , P. A. ; et al. Angew. Chem. Int. Ed. Engl. 1983 , 22 , 718 - 719 . Maessen , P. A. ; et al. Angew. Chem. Int. Ed. Engl. 1983 , 22 , 994 - 1004 . Maessen , P. A. Ph.D. Thesis, State University at Leiden, Leiden, The Netherlands, 1983. ). The role of the EPA glass in controlling conformer distributions and reaction outcomes is further explored by the extension of the studies to Lumi, whose structure differs substantially from that of its stereoisomer, Pro. Initially, the light-induced conrotatory ring openings of Pro and Lumi are expected to give cZc-Pre conformers that differ in the relative orientation of the double bond dihedral angles that define the chiral axis of the triene moiety: (-)cZ(-)c-Pre and (+)cZ(+)c-Pre, respectively. In the case of Pro, much of the cZc-Pre proceeds to tZc-Pre, the precursor of tEc-Tachy. In contrast, we show that under the same conditions most cZc-Pre formed from Lumi retains the cZc-conformation and isomerizes to cEc-Tachy. cZc-Pre from Lumi was not detected by fluorescence, but UV absorption measurements establish its formation as an essential intermediate to Tachy. Aided by theoretical calculations of conformer UV and CD spectra, we conclude that fluorescent thermodynamic Pre and nonfluorescent Pre from Lumi are both (+)cZ(+)c-Pre conformers. They differ in the orientation of the OH in the A ring, pseudoequatorial in the former and pseudoaxial in the latter. The most likely major photochemical sequences starting from Pre and Lumi are (+)cZ(+)c-Pre-eq-OH → (+)cE(+)c-Tachy-eq-OH and Lumi → (+)cZ(+)c-Pre-ax-OH → (+)cE(+)c-Tachy-eq-OH.


Assuntos
Colecalciferol/análogos & derivados , Ácido Eicosapentaenoico/química , Ergosterol/química , Vidro/química , Processos Fotoquímicos , Temperatura , Colecalciferol/síntese química , Colecalciferol/química , Isomerismo
15.
J Autoimmun ; 79: 39-52, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28126203

RESUMO

Regulatory T cells (Tregs) are a subset of CD4+ T cells with suppressive function and are critical for limiting inappropriate activation of T cells. Hence, the expansion of Tregs is an attractive strategy for the treatment of autoimmune diseases. Here, we demonstrate that the skin possesses the remarkable capacity to systemically expand Treg numbers by producing thymic stromal lymphopoietin (TSLP) in response to vitamin D receptor stimulation. An ∼2-fold increase in the proportion and absolute number of Tregs was observed in mice treated topically but not systemically with the Vitamin D3 analog MC903. This expansion of Tregs was dependent on TSLP receptor signaling but not on VDR signaling in hematopoietic cells. However, TSLP receptor expression by Tregs was not required for their proliferation. Rather, skin-derived TSLP promoted Treg expansion through dendritic cells. Importantly, treatment of skin with MC903 significantly lowered the incidence of autoimmune diabetes in non-obese diabetic mice and attenuated disease score in experimental autoimmune encephalomyelitis. Together, these data demonstrate that the skin has the remarkable potential to control systemic immune responses and that Vitamin D-mediated stimulation of skin could serve as a novel strategy to therapeutically modulate the systemic immune system for the treatment of autoimmunity.


Assuntos
Citocinas/metabolismo , Pele/imunologia , Pele/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Animais , Biomarcadores , Colecalciferol/análogos & derivados , Colecalciferol/farmacologia , Citocinas/farmacologia , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Experimental/metabolismo , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Modelos Biológicos , Transdução de Sinais/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacos
16.
Phys Chem Chem Phys ; 19(8): 5763-5777, 2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28105477

RESUMO

To investigate the role of tachysterol in the photophysical/photochemical regulation of vitamin D photosynthesis, we studied its electronic absorption properties and excited state dynamics using time-dependent density functional theory (TDDFT), second-order approximate coupled cluster theory (CC2), and non-adiabatic surface hopping molecular dynamics in the gas phase. In excellent agreement with experiments, the simulated electronic spectrum shows a broad absorption band with a remarkably higher extinction coefficient than the other vitamin D photoisomers provitamin D, lumisterol, and previtamin D. The broad band arises from the spectral overlap of four different ground state rotamers. After photoexcitation, the first excited singlet state (S1) decays with a lifetime of 882 fs. The S1 dynamics is characterized by a strong twisting of the central double bond. In 96% of all trajectories this is followed by unreactive relaxation to the ground state near a conical intersection. The double-bond twisting in the chemically unreactive trajectories induces a strong interconversion between the different rotamers. In 2.3% of the trajectories we observed [1,5]-sigmatropic hydrogen shift forming the partly deconjugated toxisterol D1. 1.4% previtamin D formation is observed via hula-twist double bond isomerization. In both reaction channels, we find a strong dependence between photoreactivity and dihedral angle conformation: hydrogen shift only occurs in cEc and cEt rotamers and double bond isomerization occurs mainly in cEc rotamers. Hence, our study confirms the previously formed hypothesis that cEc rotamers are more prone to previtamin D formation than other isomers. In addition, we also observe the formation of a cyclobutene-toxisterol in the hot ground state in 3 trajectories (0.7%). Due to its large extinction coefficient and mostly unreactive behavior, tachysterol acts mainly as a Sun shield suppressing previtamin D formation. Tachysterol shows stronger toxisterol formation than previtamin D and can thus be seen as the major degradation route of vitamin D. Absorption of low energy ultraviolet light by the cEc rotamer can lead to previtamin D formation. In addition, the cyclobutene-toxisterol, which possibly reacts thermally to previtamin D, is also preferably formed at long wavelengths. These two mechanisms are consistent with the wavelength dependent photochemistry found in experiments. Our study reinforces a recent hypothesis that tachysterol constitutes a source of previtamin D when only low energy ultraviolet light is available, as it is the case in winter or in the morning and evening hours of the day.


Assuntos
Colecalciferol/análogos & derivados , Fotossíntese , Vitamina D/biossíntese , Colecalciferol/metabolismo , Simulação de Dinâmica Molecular , Processos Fotoquímicos
17.
J Allergy Clin Immunol Pract ; 5(1): 23-31, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28065340

RESUMO

Sublingual immunotherapy (SLIT) relies on high doses of allergens to treat patients with type I allergies. Although SLIT is commonly performed without any adjuvant or delivery system, allergen(s) could be further formulated with allergen-presentation platforms to better target oral dendritic cells eliciting regulatory immune responses. Improving the availability of allergens to the immune system should enhance SLIT efficacy, while allowing to decrease allergen dosing. Herein, we present an overview of adjuvants and vector systems that have been, or could be, considered as candidate allergen-presentation platforms for the sublingual route. Such platforms encompass adjuvants capable of stimulating allergen-specific TH1 and/or regulatory CD4+ T-cell responses, including 1,25-dihydroxy vitamin D3, glucocorticoids, Toll-like receptor ligands as well as selected bacterial probiotic strains. A limiting factor for SLIT efficacy is the number of dendritic cells capturing the allergens in the upper layers of oral tissues. Thus, adsorption or encapsulation of the allergen(s) within mucoadhesive particulate vector (or delivery) systems also has the potential to significantly enhance SLIT efficacy due to a facilitated allergen uptake by tolerogenic oral dendritic cells.


Assuntos
Alérgenos/uso terapêutico , Células Dendríticas/imunologia , Mucosa Bucal/imunologia , Boca/imunologia , Imunoterapia Sublingual/métodos , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Alérgenos/imunologia , Animais , Apresentação do Antígeno , Colecalciferol/análogos & derivados , Colecalciferol/imunologia , Glucocorticoides/imunologia , Humanos , Probióticos/metabolismo , Imunoterapia Sublingual/tendências , Receptores Toll-Like/metabolismo
18.
J Dermatol ; 44(5): 567-572, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28012189

RESUMO

Bacterial colonization on skin or tonsil may influence the clinical response of patients with psoriasis to immunosuppressive drugs. However, few studies have investigated the effects of bacterial superantigens on therapy in these patients. Recently, combination therapy with topical glucocorticoids (GC) and vitamin D3 (VD3) appears to be more effective than GC or VD3 monotherapy for psoriasis. We evaluated the suppressive effects of betamethasone butyrate propionate (BBP), three VD3 derivatives (calcipotriol, maxacalcitol and tacalcitol), cyclosporin and BBP plus VD3, on concanavalin A (ConA)- or streptococcal pyrogenic enterotoxin A (SPEA)-stimulated proliferation of peripheral blood mononuclear cells (PBMC) obtained from 35 psoriasis patients. Drug concentrations effecting 50% inhibition concentration of ConA- or SPEA-stimulated PBMC proliferation were estimated. Cytokine levels of tumor necrosis factor-α, γ-interferon, interleukin-1b, -2, -4, -5, -6, -8 -10 and -12p70 in PBMC culture supernatants were measured with bead-array procedures. Suppression of PBMC proliferation by BBP was significantly lower when PBMC were stimulated by SPEA than when stimulated by ConA. In contrast, the suppressive effects of calcipotriol and tacalcitol increased significantly when PBMC were stimulated by SPEA than when stimulated by ConA. The suppressive effect of BBP on SPEA-stimulated PBMC proliferation was improved significantly by adding 1-1000 ng/mL calcipotriol, compared with BBP alone. Cytokine levels in PBMC culture supernatants were not significantly different between ConA- and SPEA-stimulated PBMC. Calcipotriol and BBP in combination markedly suppressed SPEA-stimulated PBMC proliferation. SPEA produced by colonization of hemolytic streptococci may reduce the efficacy of BBP but not VD3 derivatives in the treatment of psoriasis.


Assuntos
Betametasona/análogos & derivados , Colecalciferol/farmacologia , Glucocorticoides/farmacologia , Leucócitos Mononucleares/efeitos dos fármacos , Psoríase/tratamento farmacológico , Adulto , Idoso , Toxinas Bacterianas , Betametasona/farmacologia , Betametasona/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Colecalciferol/análogos & derivados , Colecalciferol/uso terapêutico , Citocinas/metabolismo , Feminino , Glucocorticoides/uso terapêutico , Humanos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Psoríase/imunologia
19.
Biomed Pharmacother ; 85: 141-147, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27930978

RESUMO

OBJECTIVES: The aim of this work is to study the possible mechanisms through which different immune-modulating agents can produce their beneficial effects on treatment of psoriasis and to determine whether the supplementation of these agents for psoriasis patients induces regression of psoriasis. SUBJECTS AND METHODS: One hundred fifty participants were included in this study. The participants were divided into five groups: 1. Normal control group, 2. Psoriasis patients not taking any treatment, 3. Psoriasis patients treated with anti-psoriatic treatment (including coal tar, vitamin D3 analogues and corticosteroids). 4. Psoriasis patients treated with anti-psoriatic treatment and oral metformin (850mg twice daily) and 5. Psoriasis patients treated with anti-psoriatic treatment and oral pioglitazone (15mg once a day). Demographic characteristics, diabetic index, lipid profile and liver function tests were monitored. The CD4+ Tcells, CD8+ Tcells, CD4+/CD8+ ratio, interleukin-2 (IL-2), C-reactive protein (CRP) and ceruloplasmin (CP) were assayed. RESULTS: After treatment of psoriasis patients with a traditional anti-psoriatic drug in combination with metformin and peroxisome proliferator-activated receptor gamma (PPARɤ) agonist (pioglitazone), the CD4+ T cells, IL-2, CRP, CP, ALT and AST levels were statistically significantly decreased compared to psoriasis patients without treatment. Positive and significant correlations between CD4+ % and IL-2, CRP, CP, ALT and AST in psoriasis patients were recorded. CONCLUSIONS: The activation of PPAR-γ receptors by pioglitazone results in reduced formation of the proinflammatory cytokines and infiltration by inflammatory cells. Additionally, metformin acts as a modulator of the immune system in psoriasis patients and has a remarkable effect on the early stages of psoriasis. Therefore, either pioglitazone or metformin in combination with traditional anti-psoriatic drugs provides better results in the treatment of psoriasis than does each alone.


Assuntos
Fatores Imunológicos/uso terapêutico , Metformina/uso terapêutico , Psoríase/tratamento farmacológico , Tiazolidinedionas/uso terapêutico , Corticosteroides/administração & dosagem , Corticosteroides/uso terapêutico , Adulto , Colecalciferol/análogos & derivados , Colecalciferol/uso terapêutico , Alcatrão/administração & dosagem , Alcatrão/uso terapêutico , Quimioterapia Combinada , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Masculino , Metformina/administração & dosagem , Pessoa de Meia-Idade , Pioglitazona , Psoríase/imunologia , Tiazolidinedionas/administração & dosagem
20.
J Med Chem ; 59(17): 7888-900, 2016 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-27535484

RESUMO

Vitamin D receptor (VDR) controls the expression of numerous genes through the conformational change caused by binding 1α,25-dihydroxyvitamin D3. Helix 12 in the ligand-binding domain (LBD) is key to regulating VDR activation. The structures of apo VDR-LBD and the VDR-LBD/antagonist complex are unclear. Here, we reveal their unprecedented structures in solution using a hybrid method combining small-angle X-ray scattering and molecular dynamics simulations. In apo rat VDR-LBD, helix 12 is partially unraveled, and it is positioned around the canonical active position and fluctuates. Helix 11 greatly bends toward the outside at Q396, creating a kink. In the rat VDR-LBD/antagonist complex, helix 12 does not generate the activation function 2 surface, and loop 11-12 is remarkably flexible compared to that in the apo rat VDR-LBD. On the basis of these structural insights, we propose a "folding-door model" to describe the mechanism of agonism/antagonism of VDR-LBD.


Assuntos
Apoproteínas/química , Receptores de Calcitriol/antagonistas & inibidores , Receptores de Calcitriol/química , Animais , Sítios de Ligação , Colecalciferol/análogos & derivados , Colecalciferol/química , Cristalografia por Raios X , Ligantes , Conformação Molecular , Simulação de Dinâmica Molecular , Domínios Proteicos , Ratos , Receptores de Calcitriol/agonistas , Espalhamento a Baixo Ângulo , Soluções , Raios X
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