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1.
Molecules ; 27(18)2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36144626

RESUMO

Previous investigations of the Leishmania infantum eIF4A-like protein (LieIF4A) as a potential drug target delivered cholestanol derivatives inhibitors. Here, we investigated the mode of action of cholesterol derivatives as a novel scaffold structure of LieIF4A inhibitors on the RNA-dependent ATPase activity of LieIF4A and its mammalian ortholog (eIF4AI). We compared their biochemical effects on RNA-dependent ATPase activities of both proteins and investigated if rocaglamide, a known inhibitor of eIF4A, could affect LieIF4A as well. Kinetic measurements were conducted at different concentrations of ATP, of the compound and in the presence of saturating whole yeast RNA concentrations. Kinetic analyses showed different ATP binding affinities for the two enzymes as well as different sensitivities to 7-α-aminocholesterol and rocaglamide. The 7-α-aminocholesterol inhibited LieIF4A with a higher binding affinity relative to cholestanol analogs. Cholesterol, another tested sterol, had no effect on the ATPase activity of LieIF4A or eIF4AI. The 7-α-aminocholesterol demonstrated an anti-Leishmania activity on L. infantum promastigotes. Additionally, docking simulations explained the importance of the double bond between C5 and C6 in 7-α-aminocholesterol and the amino group in the C7 position. In conclusion, Leishmania and mammalian eIF4A proteins appeared to interact differently with effectors, thus making LieIF4A a potential drug against leishmaniases.


Assuntos
Fator de Iniciação 4A em Eucariotos , Leishmania infantum , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Colestanóis/metabolismo , Colesterol/metabolismo , Fator de Iniciação 4A em Eucariotos/química , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , Mamíferos/metabolismo , Camundongos , Proteínas/metabolismo , RNA/metabolismo , Esteróis/metabolismo , Esteróis/farmacologia
2.
J Biochem Mol Toxicol ; 36(6): e23026, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35253313

RESUMO

Brassinolide is a new type of steroidal hormone with strong activities, which is well known as an efficient and low-toxicity plant growth regulator for a long time. Because steroidal hormones have a wide application prospect, brassinosteroids have been gradually explored in pharmacology and animal cells in recent decades. Brassinolide could effectively reverse the resistance of human T lymphoblastoid cell line CCRF-VCR 1000 by inhibiting the effusion of drug transported by P-glycoprotein. Brassinosteroids could also accelerate wound healing by positively eliminating inflammation and stimulating reepithelialization of the reparation stage. The occurrence of cancer is a multistep process mediated by a variety of factors. Until now, cancer has always been one group of the major diseases that threaten human health. Many studies have found that brassinosteroids have attracted a great deal of potential as an anticancer agent in the treatment of cancer cells, and most of them exert anticancer activity by inducing apoptosis in cancer cells. There are few articles on the relationship between brassinosteroids and cancer so far. Accordingly, in this article, we summarized current research about the brassinosteroids and cancers. Through the review, researchers could know more about brassinosteroids which might become a new tool for the treatment of cancer in the future, and not only a plant hormone.


Assuntos
Brassinosteroides , Neoplasias , Animais , Brassinosteroides/farmacologia , Colestanóis/metabolismo , Colestanóis/farmacologia , Neoplasias/tratamento farmacológico , Reguladores de Crescimento de Plantas/farmacologia
3.
Int J Mol Sci ; 22(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34445112

RESUMO

Brassinosteroids (BRs) are steroid phytohormones that are known to regulate plant growth and nutrient uptake and distribution. However, how BRs regulate nutrient uptake and balance in legume species is not fully understood. Here, we show that optimal BR levels are required for soybean (Glycine max L.) seedling growth, as treatments with both 24-epicastasterone (24-epiCS) and the BR biosynthesis inhibitor propiconazole (PPZ) inhibit root growth, including primary root elongation and lateral root formation and elongation. Specifically, 24-epiCS and PPZ reduced the total phosphorus and potassium levels in the shoot and affected several minor nutrients, such as magnesium, iron, manganese, and molybdenum. A genome-wide transcriptome analysis identified 3774 and 4273 differentially expressed genes in the root tip after brassinolide and PPZ treatments, respectively. The gene ontology (GO) analysis suggested that genes related to "DNA-replication", "microtubule-based movement", and "plant-type cell wall organization" were highly responsive to the brassinolide and PPZ treatments. Furthermore, consistent with the effects on the nutrient concentrations, corresponding mineral transporters were found to be regulated by BR levels, including the GmPHT1s, GmKTs, GmVIT2, GmZIPs, and GmMOT1 genes. Our study demonstrates that optimal BR levels are important for growth and mineral nutrient homeostasis in soybean seedlings.


Assuntos
Brassinosteroides/metabolismo , Glycine max/crescimento & desenvolvimento , Glycine max/metabolismo , Homeostase/fisiologia , Minerais/metabolismo , Nutrientes/metabolismo , Colestanóis/metabolismo , Fabaceae/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/metabolismo , Esteroides Heterocíclicos/metabolismo
5.
J Agric Food Chem ; 68(13): 3912-3923, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32146811

RESUMO

Gas chromatography-mass spectrometry (GC-MS) analysis revealed that castasterone and its biosynthetic precursors are found in Brachypodium distachyon. In vitro conversion experiments with crude enzyme solutions prepared from B. distachyon demonstrated the presence of the following biosynthetic sequences: campesterol → campesta-4-en-3-one → campesta-3-one → campestanol → 6-deoxocathasterone → 6-deoxoteasterone → teasterone ↔ 3-dehydroteasterone ↔ typhasterol → castasterone. campesterol → 22-hydroxycampesterol → 22-hydroxy-campesta-4-en-3-one → 22-hydroxy-campesta-3-one → 6-deoxo-3-dehydroteasterone → 3-dehydroteasterone. 6-deoxoteasterone ↔ 6-deoxo-3-dehydroteasterone ↔ 6-deoxotyphasterol → 6-deoxocastasterone → castasterone. This shows that there are campestanol-dependent and campestanol-independent pathway in B. distachyon that synthesize 24-methylated brassinosteroids (BRs). Biochemical analysis of BRs biosynthetic enzymes confirmed that BdDET2, BdCYP90B1, BdCYP90A1, BdCYP90D2, and BdCYP85A1 are orthologous to BR 5α-reductase, BR C-22 hydroxylase, BR C-3 oxidase, BR C-23 hydroxylase, and BR C-6 oxidase, respectively. Brassinolide was not identified in B. distachyon. Additionally, B. distachyon crude enzyme solutions could not catalyze the conversion of castasterone to brassinolide, and the gene encoding an ortholog of CYP85A2 (a brassinolide synthase) was not found in B. distachyon. These results strongly suggest that the end product for brassinosteroid biosynthesis which controls the growth and development of B. distachyon is not brassinolide but rather castasterone.


Assuntos
Brachypodium/metabolismo , Colestanóis/metabolismo , Vias Biossintéticas , Brachypodium/química , Brachypodium/genética , Brassinosteroides/biossíntese , Brassinosteroides/química , Colestanóis/química , Cromatografia Gasosa-Espectrometria de Massas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
J Phys Chem B ; 124(2): 355-365, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31873025

RESUMO

Brassinosteroids (BRs) are essential phytohormones, which bind to the plant receptor, BRI1, to regulate various physiological processes. The molecular mechanism of the perception of BRs by the ectodomain of BRI1 remains not fully understood. It also remains elusive why a substantial difference in biological activity exists between the BRs. In this work, we study the binding mechanisms of the two most bioactive BRs, brassinolide (BLD) and castasterone (CAT), using molecular dynamics simulations. We report free-energy landscapes of the binding processes of both ligands, as well as detailed ligand binding pathways. Our results suggest that CAT has a lower binding affinity compared to BLD due to its inability to form hydrogen-bonding interactions with a tyrosine residue in the island domain of BRI1. We uncover a conserved nonproductive binding state for both BLD and CAT, which is more stable for CAT and may further contribute to the bioactivity difference. Finally, we validate past observations about the conformational restructuring and ordering of the island domain upon BLD binding. Overall, this study provides new insights into the fundamental mechanism of the perception of the two most bioactive BRs, which may create new avenues for genetic and agrochemical control of their signaling cascade.


Assuntos
Proteínas de Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Colestanóis/metabolismo , Proteínas Quinases/metabolismo , Esteroides Heterocíclicos/metabolismo , Arabidopsis/química , Proteínas de Arabidopsis/química , Brassinosteroides/química , Colestanóis/química , Ligação de Hidrogênio , Ligantes , Modelos Químicos , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Proteínas Quinases/química , Esteroides Heterocíclicos/química , Termodinâmica , Tirosina/química
7.
J Steroid Biochem Mol Biol ; 194: 105447, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31415823

RESUMO

Dendrogenin A (DDA) is a newly-discovered steroidal alkaloid, which remains to date the first ever found in mammals. DDA is a cholesterol metabolites that induces cancer cell differentiation and death in vitro and in vivo, and thus behave like a tumor suppressor metabolite. Preliminary studies performed on 10 patients with estrogen receptor positive breast cancers (ER(+)BC) showed a strong decrease in DDA levels between normal matched tissue and tumors. This suggests that a deregulation on DDA metabolism is associated with breast carcinogenesis. To further investigate DDA metabolism on large cohorts of patients we have developed an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS) procedure for the quantification of DDA in liquid and in solid tissues. This method enabled the identification of DDA analogues such as its geometric isomer C17 and dendrogenin B (C26) in human samples showing that other 5,6α-epoxycholesterol conjugation products with biogenic amines exist as endogenous metabolites . We report here the first complete method of quantification of DDA in liquid and solid tissues using hydrophilic interaction liquid chromatography (HILIC). Two different methods of extraction using either a Bligh and Dyer organic extraction or protein precipitation were successfully applied to quantify DDA in solid and liquid tissues. The protein precipitation method was the fastest. The fact that this method is automatable opens up possibilities to study DDA metabolism in large cohorts of patients.


Assuntos
Colestanóis/análise , Imidazóis/análise , Mama/metabolismo , Neoplasias da Mama/metabolismo , Colestanóis/metabolismo , Cromatografia Líquida/métodos , Feminino , Humanos , Imidazóis/metabolismo
8.
Elife ; 82019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-31045492

RESUMO

Prey are under selection to minimize predation losses. In aquatic environments, many prey use chemical cues released by predators, which initiate predator avoidance. A prominent example of behavioral predator-avoidance constitutes diel vertical migration (DVM) in the freshwater microcrustacean Daphnia spp., which is induced by chemical cues (kairomones) released by planktivorous fish. In a bioassay-guided approach using liquid chromatography and mass spectrometry, we identified the kairomone from fish incubation water as 5α-cyprinol sulfate inducing DVM in Daphnia at picomolar concentrations. The role of 5α-cyprinol sulfate in lipid digestion in fish explains why from an evolutionary perspective fish has not stopped releasing 5α-cyprinol sulfate despite the disadvantages for the releaser. The identification of the DVM-inducing kairomone enables investigating its spatial and temporal distribution and the underlying molecular mechanism of its perception. Furthermore, it allows to test if fish-mediated inducible defenses in other aquatic invertebrates are triggered by the same compound.


Assuntos
Ácidos e Sais Biliares/metabolismo , Colestanóis/metabolismo , Daphnia/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Feromônios/metabolismo , Animais , Ácidos e Sais Biliares/isolamento & purificação , Bioensaio , Colestanóis/isolamento & purificação , Cromatografia Líquida , Peixes , Espectrometria de Massas , Feromônios/isolamento & purificação
9.
Biochimie ; 160: 130-140, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30844411

RESUMO

The bile alcohol 5ß-scymnol ([24R]-(+)-5ß-cholestan-3α,7α,12α,24,26,27-hexol) is a therapeutic nutraceutical derived from marine sources, however very little is known about its potential for biotransformation as a xenobiotic in higher vertebrates. In this study, biotransformation products of scymnol catalysed by liver microsomes isolated from normal and streptozotocin (STZ)-treated male Wistar rats were characterised by liquid chromatography-tandem mass spectroscopy (LC-MSMS). In order of increasing polarity relative to the reversed phase sorbent, structural assignments were made for four biotransformation products, namely 3-oxoscymnol (5ß-cholestan-3-one-7α,12α,24,26,27-pentol); 7-oxoscymnol (5ß-cholestan-7-one-3α,12α,24,26,27-pentol); 3ß-scymnol (5ß-cholestan-3ß,7α,12α,24,26,27-hexol) and 6ß-hydroxyscymnol (5ß-cholestan-3α,6ß,7α,12α,24,26,27-heptol). In addition, a total of eight biotransformation products were characterised from microsomal incubations of crude oxoscymnol compounds, namely 7ß-scymnol; 3,12-dioxoscymnol; 3,7-dioxoscymnol; 7,12-dioxoscymnol; 12-oxo-3ß-scymnol; 7-oxo-3ß-scymnol; 6ß-hydroxy-12-oxoscymnol and 6ß-hydroxy-7-oxoscymnol. Collectively, the results indicate hepatic enzyme-catalysed hydroxylation, dehydrogenation and epimerisation reactions on the steroid nucleus of scymnol, and provide an insight into biotransformation pathways for scymnol use as a therapeutic nutraceutical in higher vertebrates.


Assuntos
Colestanóis/química , Colestanóis/metabolismo , Cromatografia Líquida/métodos , Cetosteroides/metabolismo , Microssomos Hepáticos/metabolismo , Esteroide Hidroxilases/metabolismo , Espectrometria de Massas em Tandem/métodos , Animais , Biotransformação , Cetosteroides/química , Masculino , Ratos , Ratos Sprague-Dawley
10.
J Plant Physiol ; 232: 107-114, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30537597

RESUMO

Although structurally simple, viroids can trigger numerous changes in host plants and cause loss of yield in agronomically important crops. This study investigated changes in the endogenous status of phytohormones and antioxidant enzyme activity in Solanum tuberosum cv. Désirée in response to Potato spindle tuber viroid (PSTVd) infection. Phytohormone analysis showed that the content of endogenous jasmonic acid (JA) and its precursor cis-OPDA significantly increased in leaves, while the content of castasterone (CS) increased in both leaves and tubers of systemically infected plants compared to mock-inoculated control plants at 8 weeks post-inoculation. The indole-3-acetic acid content moderately increased only in tubers, while no differences in salicylic acid and abscisic acid content were observed between infected and control plants. Changes in endogenous phytohormone content were associated with upregulated expression of genes involved in the biosynthesis of JA and brassinosteroids, and the metabolism of auxins. Additionally, PSTVd infection provoked overproduction of hydrogen peroxide, which coincided with increased activity of guaiacol peroxidase in leaves and ascorbate peroxidase in potato tubers. The activity of catalase decreased in leaves, while superoxide dismutase activity remained steady regardless of the treatment and organ type. Total ascorbate and glutathione did not change significantly, although a shift towards oxidized forms was observed. Results suggest the existence of organ-specific differences in phytohormone and antioxidative responses in potato upon PSTVd infection. Possible effects of the observed changes on symptom development are discussed.


Assuntos
Doenças das Plantas/virologia , Reguladores de Crescimento de Plantas/metabolismo , Solanum tuberosum/fisiologia , Viroides/metabolismo , Antioxidantes/metabolismo , Brassinosteroides/metabolismo , Clorofila/metabolismo , Colestanóis/metabolismo , Ciclopentanos/metabolismo , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Folhas de Planta/metabolismo , Tubérculos/metabolismo , Solanum tuberosum/metabolismo , Solanum tuberosum/virologia
11.
Sci Rep ; 8(1): 16622, 2018 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-30413746

RESUMO

When a spermatozoon shows chemotactic behavior, transient [Ca2+]i increases in the spermatozoon are induced by an attractant gradient. The [Ca2+]i increase triggers a series of stereotypic responses of flagellar waveforms that comprise turning and straight-swimming. However, the molecular mechanism of [Ca2+]i modulation controlled by the attractants is not well defined. Here, we examined receptive mechanisms for the sperm attractant, SAAF, in the ascidian, Ciona intestinalis, and identified a plasma membrane Ca2+-ATPase (PMCA) as a SAAF-binding protein. PMCA is localized in sperm flagella membranes and seems to interact with SAAF through basic amino acids located in the second and third extracellular loops. ATPase activity of PMCA was enhanced by SAAF, and PMCA inhibitors, 5(6)-Carboxyeosin diacetate and Caloxin 2A1, inhibited chemotactic behavior of the sperm. Furthermore, Caloxin 2A1 seemed to inhibit efflux of [Ca2+]i in the sperm, and SAAF seemed to competitively reduce the effect of Caloxin 2A1. On the other hand, chemotactic behavior of the sperm was disordered not only at low-Ca2+, but also at high-Ca2+ conditions. Thus, PMCA is a potent candidate for the SAAF receptor, and direct control of Ca2+ efflux via PMCA is a fundamental mechanism to mediate chemotactic behavior in the ascidian spermatozoa.


Assuntos
Cálcio/metabolismo , Membrana Celular/enzimologia , Quimiotaxia , Ciona intestinalis/fisiologia , Peptídeos/metabolismo , ATPases Transportadoras de Cálcio da Membrana Plasmática/metabolismo , Espermatozoides/fisiologia , Animais , Sinalização do Cálcio , Colestanóis/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Masculino , ATPases Transportadoras de Cálcio da Membrana Plasmática/genética , Motilidade dos Espermatozoides , Ésteres do Ácido Sulfúrico/metabolismo
12.
Biochem Pharmacol ; 153: 75-81, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29409832

RESUMO

Dendrogenin A (DDA) is a mammalian cholesterol metabolite recently identified that displays tumor suppressor properties. The discovery of DDA has revealed the existence in mammals of a new metabolic branch in the cholesterol pathway centered on 5,6α-epoxycholesterol and bridging cholesterol metabolism with histamine metabolism. Metabolic studies showed a drop in DDA levels in cancer cells and tumors compared to normal cells, suggesting a link between DDA metabolism deregulation and oncogenesis. Importantly, complementation of cancer cells with DDA induced 1) cancer cell re-differentiation, 2) blockade of 6-oxo-cholestan-3ß,5α-diol (OCDO) production, an endogenous tumor promoter and 3) lethal autophagy in tumors. Importantly, by binding the liver X receptor (LXR), DDA activates the expression of genes controlling autophagy. These genes include NR4A1, NR4A3, LC3 and TFEB. The canonical LXR ligands 22(R)hydroxycholesterol, TO901317 and GW3965 did not induce these effects indicating that DDA delineates a new class of selective LXR modulator (SLiM). The induction of lethal autophagy by DDA was associated with the accumulation in cancer cells of lysosomes and of the pro-lysosomal cholesterol precursor zymostenol due to the inhibition of the 3ß-hydroxysteroid-Δ8Δ7-isomerase enzyme (D8D7I). The anti-cancer efficacy of DDA was established on different mouse and human cancers such as breast cancers, melanoma and acute myeloid leukemia, including patient derived xenografts, and did not discriminate bulk cancer cells from cancer cell progenitors. Together these data highlight that the mammalian metabolite DDA is a promising anticancer compound with a broad range of anticancer applications. In addition, DDA and LXR are new actors in the transcriptional control of autophagy and DDA being a "first in line" driver of lethal autophagy in cancers via the LXR.


Assuntos
Antineoplásicos/metabolismo , Autofagia/fisiologia , Colestanóis/metabolismo , Colesterol/metabolismo , Imidazóis/metabolismo , Receptores X do Fígado/metabolismo , Neoplasias/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Autofagia/efeitos dos fármacos , Linhagem Celular Tumoral , Colestanóis/farmacologia , Colestanóis/uso terapêutico , Colesterol/farmacologia , Colesterol/uso terapêutico , Humanos , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Neoplasias/tratamento farmacológico
13.
New Phytol ; 216(3): 868-881, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28833172

RESUMO

Plant hormones (PH) adjust plant growth to environmental conditions such as nutrient availability. Although responses of individual PHs to growth-determining nutrient supplies have been reported, little is known about simultaneous dynamics in the metabolism of different PH species. Brassica napus seedlings were grown under increasing supply of B, and LC-MS/MS was used to characterize bioactive forms of different PH species together with several of their precursors, storage and inactivated forms. Increasing shoot B concentrations in response to B supply were accompanied by decreasing concentrations of abscisic acid (ABA) and indole-3-acetic acid (IAA), which appeared to be synthesized under B deficiency mainly via indole-3-acetonitrile (IAN). By contrast, shoot B concentrations correlated closely with cytokinins, and the B-dependent growth response appeared to be triggered primarily by de-novo synthesis of cytokinins and by re-routing less active towards highly active forms of cytokinin. Also gibberellin biosynthesis strongly increased with B supply, in particular gibberellin species from the non-13-hydroxylation pathway. The brassinosteroid castasterone appeared to support shoot growth primarily at suboptimal B nutrition. These results indicate that a variable B nutritional status causes coordinated changes in PH metabolism as prerequisite for an adjusted growth response.


Assuntos
Boro/farmacologia , Brassica napus/efeitos dos fármacos , Brassica napus/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Ácido Abscísico/metabolismo , Colestanóis/metabolismo , Citocininas/metabolismo , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Espectrometria de Massas em Tandem
14.
J Steroid Biochem Mol Biol ; 174: 120-127, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28807679

RESUMO

5α-Cyprinol 27-sulfate is the major biliary bile salt present in cypriniform fish including the zebrafish (Danio rerio). The current study was designed to identify the zebrafish cytosolic sulfotransferase (Sult) enzyme(s) capable of sulfating 5α-cyprinol and to characterize the zebrafish 5α-cyprinol-sulfating Sults in comparison with human SULT2A1. Enzymatic assays using zebrafish homogenates showed 5α-cyprinol-sulfating activity. A systematic analysis, using a panel of recombinant zebrafish Sults, revealed two Sult2 subfamily members, Sult2st2 and Sult2st3, as major 5α-cyprinol-sulfating Sults. Both enzymes showed higher activities using 5α-cyprinol as the substrate, compared to their activity with DHEA, a representative substrate for mammalian SULT2 family members, particularly SULT2A1. pH-Dependence and kinetics experiments indicated that the catalytic properties of zebrafish Sult2 family members in mediating the sulfation of 5α-cyprinol were different from those of either zebrafish Sult3st4 or human SULT2A1. Collectively, these results imply that both Sult2st2 and Sult2st3 have evolved to sulfate specifically C27-bile alcohol, 5α-cyprinol, in Cypriniform fish, whereas the enzymatic characteristics of zebrafish Sult3 members, particularly Sult3st4, correlated with those of human SULT2A1.


Assuntos
Arilsulfotransferase/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Animais , Colestanóis/metabolismo , Ácidos Cólicos/metabolismo , Desidroepiandrosterona/metabolismo , Embrião não Mamífero , Humanos , Peixe-Zebra
15.
Bioorg Med Chem ; 25(17): 4566-4578, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28751198

RESUMO

Brassinolide (BL) and castasterone (CS) are the representative members of brassinosteroid class of plant steroid hormone having plant growth promoting activity. In this study, eleven CS analogs bearing a variety of side chains were synthesized to determine the effect of the side chain structures on the BL-like activity. The plant hormonal activity was evaluated in a dwarf rice lamina inclination assay, and the potency was determined as the reciprocal logarithm of the 50% effective dose (ED50) from each dose-response curve. The reciprocal logarithm of ED50 (pED50) was decreased dramatically upon deletion of the C-28 methyl group of CS. The introduction of oxygen-containing groups such as hydroxy, methoxy, and ethoxycarbonyl was also unfavorable to the activity. The pED50 was influenced by the geometry of carbon-carbon double bond between C-24 and C-25 (cis and trans), but the introduction of a fluorine atom at the C-25 position of the double bond did not significantly change the activity. The binding free energy (ΔG) was calculated for all ligand-receptor binding interactions using molecular dynamics, resulting that ΔG is linearly correlated with the pED50.


Assuntos
Colestanóis/química , Reguladores de Crescimento de Plantas/química , Sítios de Ligação , Brassinosteroides/química , Brassinosteroides/metabolismo , Brassinosteroides/farmacologia , Colestanóis/metabolismo , Colestanóis/farmacologia , Ligantes , Simulação de Acoplamento Molecular , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Estrutura Terciária de Proteína , Esteroides Heterocíclicos/química , Esteroides Heterocíclicos/metabolismo , Esteroides Heterocíclicos/farmacologia
16.
J Chem Ecol ; 43(6): 543-549, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28634722

RESUMO

Sea lamprey, Petromyzon marinus, rely heavily on chemical cues that mediate their life history events, such as migration and reproduction. Here, we describe petromyzone A-C (1-3), three novel bile alcohols that are highly oxidized and sulfated, isolated from water conditioned with spermiated male sea lamprey. Structures of these compounds were unequivocally established by spectroscopic analyses and by comparison with spectra of known compounds. Electro-olfactogram recordings showed that 1 at 10-11 M was stimulatory to the adult sea lamprey olfactory epithelium, while 2 and 3 were stimulatory at 10-13 M. Behavioral assays indicated that 1 is attractive, 2 is not attractive or repulsive, and 3 is repulsive to ovulated female sea lamprey. The results suggest that 1 and 2 may be putative pheromones that mediate chemical communication in sea lamprey. The identification of these three components enhances our understanding of the structures and functions of sex pheromone components in this species and may provide useful behavioral manipulation tools for the integrated management of sea lamprey, a destructive invader in the Laurentian Great Lakes.


Assuntos
Colestanóis/química , Colestanóis/metabolismo , Petromyzon/fisiologia , Atrativos Sexuais/química , Atrativos Sexuais/fisiologia , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Sinais (Psicologia) , Feminino , Masculino , Espectrometria de Massas , Estrutura Molecular , Mucosa Olfatória/fisiologia , Ovulação , Esteroides/química , Esteroides/metabolismo
17.
Biochim Biophys Acta Biomembr ; 1859(6): 1099-1113, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28257814

RESUMO

We introduce the novel fluorescent cholesterol probe RChol in which a sulforhodamine group is linked to the sixth carbon atom of the steroid backbone of cholesterol. The same position has recently been selected to generate the fluorescent reporter 6-dansyl-cholestanol (DChol) and the photoreactive 6-azi-cholestanol. In comparison with DChol, RChol is brighter, much more photostable, and requires less energy for excitation, i.e. favorable conditions for microscopical imaging. RChol easily incorporates into methyl-ß-cyclodextrin forming a water-soluble inclusion complex that acts as an efficient sterol donor for cells and membranes. Like cholesterol, RChol possesses a free 3'OH group, a prerequisite to undergo intracellular esterification. RChol was also able to support the growth of cholesterol auxotrophic cells and can therefore substitute for cholesterol as a major component of the plasma membrane. According to subcellular fractionation, slight amounts of RChol (~12%) were determined in low-density Triton-insoluble fractions whereas the majority of RChol was localized in non-rafts fractions. In phase-separated giant unilamellar vesicles, RChol preferentially partitions in liquid-disordered membrane domains. Intracellular RChol was transferred to extracellular sterol acceptors such as high density lipoproteins in a dose-dependent manner. Unlike DChol, RChol was not delivered to the cholesterol storage pathway. Instead, it translocated to endosomes/lysosomes with some transient contacts to peroxisomes. Thus, RChol is considered as a useful probe to study the endosomal/lysosomal pathway of cholesterol.


Assuntos
Colesterol/química , Endossomos/metabolismo , Corantes Fluorescentes/metabolismo , Lisossomos/metabolismo , Sondas Moleculares/metabolismo , Rodaminas/química , Células 3T3-L1 , Animais , Células CHO , Fracionamento Celular , Colestanóis/química , Colestanóis/metabolismo , Cricetulus , Endossomos/química , Corantes Fluorescentes/síntese química , Células HEK293 , Humanos , Lisossomos/química , Microdomínios da Membrana , Camundongos , Sondas Moleculares/síntese química , Octoxinol/química , Imagem Óptica , Lipossomas Unilamelares/química , Lipossomas Unilamelares/metabolismo , beta-Ciclodextrinas/química
18.
Molecules ; 21(9)2016 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-27563866

RESUMO

A sensitive and reliable method was developed and validated for the determination of unsaturated bile alcohols in sea lamprey tissues using liquid-liquid extraction and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The liver, kidney, and intestine samples were extracted with acetonitrile and defatted by n-hexane. Gradient UHPLC separation was performed using an Acquity BEH C18 column with a mobile phase of water and methanol containing 20 mM triethylamine. Multiple reaction monitoring modes of precursor-product ion transitions for each analyte was used. This method displayed good linearity, with correlation coefficients greater than 0.99, and was validated. Precision and accuracy (RSD %) were in the range of 0.31%-5.28%, while mean recoveries were between 84.3%-96.3%. With this technique, sea lamprey tissue samples were analyzed for unsaturated bile alcohol analytes. This method is practical and particularly suitable for widespread putative pheromone residue analysis.


Assuntos
Colestanóis/química , Colestanóis/metabolismo , Lampreias/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Oxirredução
19.
Biochimie ; 130: 109-114, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27262406

RESUMO

Tamoxifen (Tam) was developed as a ligand and modulator of estrogen receptor α (ERα) and is one of the main drugs used globally for the hormonotherapy of breast cancers. Besides ERα, Tam also binds with high affinity to the microsomal antiestrogen binding site (AEBS). The AEBS is a hetero-oligomeric proteinaceous complex with cholesterol-5,6-epoxide hydrolase (ChEH) activity that is associated with an intracellular histamine (HA) binding site. The enzymatic activities of the ChEH subunits control developmental programs in mammals and transform cholesterol-5,6-epoxides (5,6-EC) into cholestane-3ß,5α,6ß-triol. Inhibition of the ChEH activity by pharmacological agents such as Tam induce cancer cell re-differentiation through the accumulation of 5,6-EC. A few years ago, the putative chemical reactivity of the 5,6-EC epoxide group towards nucleophiles led our group to hypothesize that 5,6-EC could react with HA that was co-localized at the AEBS to give a new molecule involved in cell differentiation. This hypothesis was chemically tested and the conjugation of 5,6α-EC: with HA was found possible but only under catalytic conditions. It gave a stereo-selective single product of transformation which was named dendrogenin A (DDA). DDA was found to display potent cancer cell differentiation and anticancer properties in vitro and in vivo, suggesting that it was a tumor suppressor metabolite. The presence of DDA was then established in several mammalian tissues, providing the first evidence of a steroidal alkaloid metabolite in mammals. The discovery of DDA highlights a new metabolic pathway in mammals which lies at the crossroads of cholesterol and histamine metabolism and produces this tumor suppressor metabolite.


Assuntos
Antineoplásicos/metabolismo , Colestanóis/metabolismo , Colesterol/metabolismo , Descoberta de Drogas , Imidazóis/metabolismo , Tamoxifeno/metabolismo , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Colestanóis/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/metabolismo , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Imidazóis/farmacologia , Tamoxifeno/farmacologia
20.
Biochem Soc Trans ; 44(2): 652-8, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-27068984

RESUMO

In this short review we provide a synopsis of recent developments in oxysterol research highlighting topics of current interest to the community. These include the involvement of oxysterols in neuronal development and survival, their participation in the immune system, particularly with respect to bacterial and viral infection and to Th17-cell development, and the role of oxysterols in breast cancer. We also discuss the value of oxysterol analysis in the diagnosis of disease.


Assuntos
Oxisteróis/metabolismo , Sobrevivência Celular , Colestanóis/metabolismo , Humanos , Imidazóis/metabolismo , Sistema Imunitário/metabolismo , Neurônios/citologia , Receptores de Estrogênio/metabolismo
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