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1.
J Nat Prod ; 86(1): 209-221, 2023 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-36583957

RESUMO

Continued efforts to expand the structural diversity of dichapetalins and explore further the cytotoxic structure-activity relationships have led to the isolation of 17 undescribed analogues, dichapelonins A-Q (1-17), and three known compounds (18-20) from the twigs of Dichapetalum longipetalum. Compounds 1-17 comprise five compound classes as classified by varied C6-C2 conjugates at the A ring of the 13,30-cyclodammarane skeleton, and their structures were determined by spectroscopic data analysis, experimental electronic circular dichroism measurements, and X-ray crystallography. Biological tests revealed compounds 1-7 with a phenyl-butadiene appendage to be the most potent cytotoxic compound type of those evaluated.


Assuntos
Antineoplásicos , Estrutura Molecular , Antineoplásicos/farmacologia , Relação Estrutura-Atividade
2.
Can J Physiol Pharmacol ; 99(10): 1057-1068, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34492212

RESUMO

G (1-5)-NH2, G (1-7)-NH2, and G (1-9) are the active fragments of ghrelin. The aim of this study was to investigate the antinociceptive effects, their ability to cross the blood-brain barrier, and the receptor mechanism(s) of these fragments using the tail withdrawal test in male Kunming mice. The antinociceptive effects of these fragments (2, 6, 20, and 60 nmol/mouse) were tested at 5, 10, 20, 30, 40, 50, and 60 min after intravenous (i.v.) injection. These fragments induced dose- and time-related antinociceptive effects relative to saline. Using the near infrared fluorescence imaging experiments, our results showed that these fragments could cross the brain-blood barrier and enter the brain. The antinociceptive effects of these fragments were completely antagonized by naloxone (intracerebroventricular, i.c.v.); however, naloxone methiodide (intraperitoneal, i.p.), which is the peripheral restricted opioid receptor antagonist, did not antagonize these antinociceptive effects. Furthermore, the GHS-R1α antagonist [D-Lys3]-GHRP-6 (i.c.v.) completely antagonized these antinociceptive effects, too. These results suggested that these fragments induced antinociceptive effects through central opioid receptors and GHS-R1α. In conclusion, our studies indicated that these active fragments of ghrelin could cross the brain-blood barrier and enter the brain and induce antinociceptive effects through central opioid receptors and GHS-R1α after intravenous injection.


Assuntos
Dor Aguda/tratamento farmacológico , Analgésicos/farmacologia , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Grelina/administração & dosagem , Grelina/farmacocinética , Temperatura Alta/efeitos adversos , Dor Aguda/etiologia , Dor Aguda/metabolismo , Dor Aguda/patologia , Animais , Animais não Endogâmicos , Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Grelina/farmacologia , Masculino , Camundongos , Antagonistas de Entorpecentes/farmacologia , Receptores de Grelina/antagonistas & inibidores , Receptores de Grelina/metabolismo , Receptores Opioides/química , Receptores Opioides/metabolismo
3.
J Infect Dis ; 222(1): 38-43, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32348485

RESUMO

Currently, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been reported in almost all countries globally. No effective therapy has been documented for COVID-19, and the role of convalescent plasma therapy is unknown. In the current study, 6 patients with COVID-19 and respiratory failure received convalescent plasma a median of 21.5 days after viral shedding was first detected, all tested negative for SARS-CoV-2 RNA within 3 days after infusion, and 5 eventually died. In conclusion, convalescent plasma treatment can end SARS-CoV-2 shedding but cannot reduce the mortality rate in critically ill patients with end-stage COVID-19, and treatment should be initiated earlier.


Assuntos
Anticorpos Antivirais/uso terapêutico , Betacoronavirus/genética , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/terapia , Pneumonia Viral/mortalidade , Pneumonia Viral/terapia , Eliminação de Partículas Virais/imunologia , Adulto , Idoso , Doadores de Sangue , COVID-19 , China , Infecções por Coronavirus/virologia , Estado Terminal , Feminino , Humanos , Imunização Passiva/efeitos adversos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/virologia , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , SARS-CoV-2 , Taxa de Sobrevida , Resultado do Tratamento , Soroterapia para COVID-19
4.
Acta Pharmacol Sin ; 41(5): 731-732, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32081977

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

5.
Proc Natl Acad Sci U S A ; 112(16): 5087-92, 2015 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-25848010

RESUMO

Prey shifts in carnivorous predators are events that can initiate the accelerated generation of new biodiversity. However, it is seldom possible to reconstruct how the change in prey preference occurred. Here we describe an evolutionary "smoking gun" that illuminates the transition from worm hunting to fish hunting among marine cone snails, resulting in the adaptive radiation of fish-hunting lineages comprising ∼100 piscivorous Conus species. This smoking gun is δ-conotoxin TsVIA, a peptide from the venom of Conus tessulatus that delays inactivation of vertebrate voltage-gated sodium channels. C. tessulatus is a species in a worm-hunting clade, which is phylogenetically closely related to the fish-hunting cone snail specialists. The discovery of a δ-conotoxin that potently acts on vertebrate sodium channels in the venom of a worm-hunting cone snail suggests that a closely related ancestral toxin enabled the transition from worm hunting to fish hunting, as δ-conotoxins are highly conserved among fish hunters and critical to their mechanism of prey capture; this peptide, δ-conotoxin TsVIA, has striking sequence similarity to these δ-conotoxins from piscivorous cone snail venoms. Calcium-imaging studies on dissociated dorsal root ganglion (DRG) neurons revealed the peptide's putative molecular target (voltage-gated sodium channels) and mechanism of action (inhibition of channel inactivation). The results were confirmed by electrophysiology. This work demonstrates how elucidating the specific interactions between toxins and receptors from phylogenetically well-defined lineages can uncover molecular mechanisms that underlie significant evolutionary transitions.


Assuntos
Caramujo Conus/fisiologia , Peixes/fisiologia , Comportamento Predatório/fisiologia , Sequência de Aminoácidos , Animais , Bioensaio , Conotoxinas/química , Conotoxinas/toxicidade , Caramujo Conus/anatomia & histologia , Dados de Sequência Molecular , Peptídeos/metabolismo , Filogenia
6.
J Biol Chem ; 291(13): 7205-20, 2016 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-26817840

RESUMO

Cone snail toxins are well known blockers of voltage-gated sodium channels, a property that is of broad interest in biology and therapeutically in treating neuropathic pain and neurological disorders. Although most conotoxin channel blockers function by direct binding to a channel and disrupting its normal ion movement, conotoxin µO§-GVIIJ channel blocking is unique, using both favorable binding interactions with the channel and a direct tether via an intermolecular disulfide bond. Disulfide exchange is possible because conotoxin µO§-GVIIJ contains anS-cysteinylated Cys-24 residue that is capable of exchanging with a free cysteine thiol on the channel surface. Here, we present the solution structure of an analog of µO§-GVIIJ (GVIIJ[C24S]) and the results of structure-activity studies with synthetic µO§-GVIIJ variants. GVIIJ[C24S] adopts an inhibitor cystine knot structure, with two antiparallel ß-strands stabilized by three disulfide bridges. The loop region linking the ß-strands (loop 4) presents residue 24 in a configuration where it could bind to the proposed free cysteine of the channel (Cys-910, rat NaV1.2 numbering; at site 8). The structure-activity study shows that three residues (Lys-12, Arg-14, and Tyr-16) located in loop 2 and spatially close to residue 24 were also important for functional activity. We propose that the interaction of µO§-GVIIJ with the channel depends on not only disulfide tethering via Cys-24 to a free cysteine at site 8 on the channel but also the participation of key residues of µO§-GVIIJ on a distinct surface of the peptide.


Assuntos
Conotoxinas/química , Dissulfetos/química , Proteínas Musculares/química , Canal de Sódio Disparado por Voltagem NAV1.2/química , Bloqueadores dos Canais de Sódio/química , Canais de Sódio/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Conotoxinas/síntese química , Cristalografia por Raios X , Expressão Gênica , Modelos Moleculares , Dados de Sequência Molecular , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Mutação , Canal de Sódio Disparado por Voltagem NAV1.2/genética , Canal de Sódio Disparado por Voltagem NAV1.2/metabolismo , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Ratos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Caramujos/química , Bloqueadores dos Canais de Sódio/síntese química , Canais de Sódio/genética , Canais de Sódio/metabolismo , Técnicas de Síntese em Fase Sólida , Relação Estrutura-Atividade
7.
Acta Pharmacol Sin ; 38(4): 551-560, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28112184

RESUMO

Histone deacetylases (HDACs), especially HDAC1, 2, 3 and 4, are abundantly expressed and over-activated in prostate cancer that is correlated with the poor prognosis. Thus, inhibition of HDAC activity has emerged as a potential alternative option for prostate cancer therapy. Chromopeptide A is a depsipeptide isolated from the marine sediment-derived bacterium Chromobacterium sp. HS-13-94; it has a chemical structure highly similar to FK228, a class I HDAC inhibitor that is approved by FDA for treating T-cell lymphoma. In this study, we determined whether chromopeptide A, like FK228, acted as a class I HDAC inhibitor, and whether chromopeptide A could inhibit the growth and migration of human prostate cancer in vitro and in vivo. HDAC enzyme selectivity and kinetic analysis revealed that chromopeptide A selectively inhibited the enzymatic activities of HDAC1, 2, 3 and 8 in a substrate non-competitive manner with comparable IC50 values for each HDAC member as FK228 in vitro. Importantly, chromopeptide A dose-dependently suppressed the proliferation of human prostate cancer cell lines PC3, DU145 and LNCaP with IC50 values of 2.43±0.02, 2.08±0.16, and 1.75±0.06 nmol/L, respectively, accompanied by dose-dependent inhibition of HDAC enzymatic activity in PC3 and DU145 cells. Chromopeptide A (0.2-50 nmol/L) caused G2/M phase arrest and induced apoptosis in the prostate cancer cell lines. Moreover, chromopeptide A dose-dependently inhibited the migration of PC3 cells. In mice bearing PC3 prostate cancer xenografts, intravenous injection of chromopeptide A (1.6, 3.2 mg/kg, once a week for 18 d) significantly suppressed the tumor growth, which was associated with increased expression levels of Ac-H3 and p21 in tumor tissues. Our results identify chromopeptide A as a novel class I HDAC inhibitor and provide therapeutic strategies that may be implemented in prostate cancer.


Assuntos
Antineoplásicos/uso terapêutico , Inibidores de Histona Desacetilases/uso terapêutico , Peptídeos Cíclicos/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Xenoenxertos , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Neoplasias da Próstata/patologia
8.
Proc Natl Acad Sci U S A ; 111(7): 2758-63, 2014 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-24497506

RESUMO

A cone snail venom peptide, µO§-conotoxin GVIIJ from Conus geographus, has a unique posttranslational modification, S-cysteinylated cysteine, which makes possible formation of a covalent tether of peptide to its target Na channels at a distinct ligand-binding site. µO§-conotoxin GVIIJ is a 35-aa peptide, with 7 cysteine residues; six of the cysteines form 3 disulfide cross-links, and one (Cys24) is S-cysteinylated. Due to limited availability of native GVIIJ, we primarily used a synthetic analog whose Cys24 was S-glutathionylated (abbreviated GVIIJSSG). The peptide-channel complex is stabilized by a disulfide tether between Cys24 of the peptide and Cys910 of rat (r) NaV1.2. A mutant channel of rNaV1.2 lacking a cysteine near the pore loop of domain II (C910L), was >10(3)-fold less sensitive to GVIIJSSG than was wild-type rNaV1.2. In contrast, although rNaV1.5 was >10(4)-fold less sensitive to GVIIJSSG than NaV1.2, an rNaV1.5 mutant with a cysteine in the homologous location, rNaV1.5[L869C], was >10(3)-fold more sensitive than wild-type rNaV1.5. The susceptibility of rNaV1.2 to GVIIJSSG was significantly altered by treating the channels with thiol-oxidizing or disulfide-reducing agents. Furthermore, coexpression of rNaVß2 or rNaVß4, but not that of rNaVß1 or rNaVß3, protected rNaV1.1 to -1.7 (excluding NaV1.5) against block by GVIIJSSG. Thus, GVIIJ-related peptides may serve as probes for both the redox state of extracellular cysteines and for assessing which NaVß- and NaVα-subunits are present in native neurons.


Assuntos
Conotoxinas/toxicidade , Dissulfetos/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.2/metabolismo , Neurônios/metabolismo , Bloqueadores do Canal de Sódio Disparado por Voltagem/toxicidade , Sequência de Aminoácidos , Animais , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Conotoxinas/genética , Conotoxinas/metabolismo , Cisteína/metabolismo , Primers do DNA/genética , DNA Complementar/genética , Dados de Sequência Molecular , Oócitos/metabolismo , Técnicas de Patch-Clamp , Ratos , Análise de Sequência de DNA , Espectrometria de Massas em Tandem , Bloqueadores do Canal de Sódio Disparado por Voltagem/metabolismo
9.
Ann Plast Surg ; 78(1): 22-27, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27015335

RESUMO

BACKGROUND: Nipple-sparing mastectomy (NSM) preserves the native skin envelope, including the nipple-areolar skin, and has significant benefits including improved aesthetic outcome and psychosocial well-being. Patients with prior breast scars undergoing NSM are thought to be at increased risk for postoperative complications, such as skin and/or nipple necrosis. This study describes our experience performing NSM in patients who have had prior breast surgery and aims to identify potential risk factors in this subset of patients. METHODS: A retrospective review of all patients undergoing nipple sparing mastectomy at The University of Utah from 2005 to 2011 was performed. Fifty-two patients had prior breast scars, for a total of 65 breasts. Scars were categorized into 4 groups depending on scar location: inframammary fold, outer quadrant, periareolar, and circumareolar. Information regarding patient demographics, social and medical history, treatment intent, and postoperative complications were collected and analyzed. RESULTS: Eight of the 65 breasts (12%) developed a postoperative infection requiring antibiotic treatment. Tobacco use was associated with an increased risk of infection in patients with prior breast scars (odds ratio [OR], 7.95; 95% confidence interval [CI], 1.37-46.00; P = 0.0206). There was a 13.8% rate of combined nipple and skin flap necrosis and receipt of chemotherapy (OR, 5.00; CI, 1.11-22.46; P = 0.0357) and prior BCT (OR, 12.5; CI, 2.2-71.0; P = 0.004) were found to be associated with skin flap or NAC necrosis. CONCLUSIONS: Nipple-sparing mastectomy is a safe and viable option for patients with a prior breast scar. Our results are comparable to the published data in patients without a prior scar. Caution should be exercised with patients who have a history of tobacco use or those requiring chemotherapy because these patients are at increased risk for infection and NAC/skin flap necrosis, respectively, when undergoing NSM in the setting of a prior breast scar.


Assuntos
Cicatriz/etiologia , Mastectomia Subcutânea , Complicações Pós-Operatórias/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
10.
Acta Pharmacol Sin ; 37(12): 1587-1596, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27616574

RESUMO

AIM: Inhibition of heat shock protein (Hsp90) has been proven to be effective in overriding primary and acquired resistance of kinase inhibitors. In this study, we investigated the role of FS-108, a newly developed Hsp90 inhibitor, to overcome gefitinib resistance in EGFR mutant non-small cell lung cancer cells. METHODS: Cell proliferation was assessed using the SRB assay. Cell cycle distribution and apoptosis were analyzed by flow cytometry. Protein expression was examined by Western blotting. The in vivo effectiveness of FS-108 was determined in an NCI-H1975 subcutaneous xenograft model. RESULTS: FS-108 triggered obvious growth inhibition in gefitinib-resistant HCC827/GR6, NCI-H1650 and NCI-H1975 cells through inducing G2/M phase arrest and apoptosis. FS-108 treatment resulted in a remarkable degradation of key client proteins involved in gefitinib resistance and further abrogated their downstream signaling pathways. Interestingly, FS-108 alone exerted an identical or superior effect on circumventing gefitinib resistance compared to combined kinase inhibition. Finally, the ability of FS-108 to overcome gefitinib resistance in vivo was validated in an NCI-H1975 xenograft model. CONCLUSION: FS-108 is a powerful agent that impacts the survival of gefitinib-resistant cells in vitro and in vivo through targeting Hsp90.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Receptores ErbB/genética , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Isoxazóis/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Oxazóis/farmacologia , Quinazolinas/farmacologia , Resorcinóis/farmacologia , Animais , Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Gefitinibe , Xenoenxertos , Humanos , Isoxazóis/uso terapêutico , Neoplasias Pulmonares/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutação , Transplante de Neoplasias , Oxazóis/uso terapêutico , Resorcinóis/uso terapêutico
11.
Biochemistry ; 54(25): 3911-20, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26039939

RESUMO

µO§-Conotoxin GVIIJ is a 35-amino acid peptide that readily blocks six of eight tested NaV1 subunit isoforms of voltage-gated sodium channels. µO§-GVIIJ is unusual in having an S-cysteinylated cysteine (at residue 24). A proposed reaction scheme involves the peptide-channel complex stabilized by a disulfide bond formed via thiol-disulfide exchange between Cys24 of the peptide and a Cys residue at neurotoxin receptor site 8 in the pore module of the channel (specifically, Cys910 of rat NaV1.2). To examine this model, we synthesized seven derivatives of µO§-GVIIJ in which Cys24 was disulfide-bonded to various thiols (or SR groups) and tested them on voltage-clamped Xenopus laevis oocytes expressing NaV1.2. In the proposed model, the SR moiety is a leaving group that is no longer present in the final peptide-channel complex; thus, the same koff value should be obtained regardless of the SR group. We observed that all seven derivatives, whose kon values varied over a 30-fold range, had the same koff value. Concordant results were observed with NaV1.6, for which the koff was 17-fold larger. Additionally, we tested two µO§-GVIIJ derivatives (where SR was glutathione or a free thiol) on two NaV1.2 Cys replacement mutants (NaV1.2[C912A] and NaV1.2[C918A]) without and with reduction of channel disulfides by dithiothreitol. The results indicate that Cys910 in wild-type NaV1.2 has a free thiol and conversely suggest that in NaV1.2[C912A] and NaV1.2[C918A], Cys910 is disulfide-bonded to Cys918 and Cys912, respectively. Redox states of extracellular cysteines of sodium channels have hitherto received scant attention, and further experiments with GVIIJ may help fill this void.


Assuntos
Conotoxinas/química , Cisteína/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.2/química , Animais , Sítios de Ligação , Conotoxinas/metabolismo , Cisteína/química , Cisteína/genética , Dissulfetos/química , Dissulfetos/metabolismo , Cinética , Canal de Sódio Disparado por Voltagem NAV1.2/genética , Canal de Sódio Disparado por Voltagem NAV1.2/metabolismo , Oócitos , Oxirredução , Ratos , Xenopus laevis
12.
J Neurophysiol ; 113(7): 2289-301, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25632083

RESUMO

We investigated the identities of the isoforms of the α (NaV1)- and ß (NaVß)-subunits of voltage-gated sodium channels, including those responsible for action potentials in rodent sciatic nerves. To examine α-subunits, we used seven µ-conotoxins, which target site 1 of the channel. With the use of exogenously expressed channels, we show that two of the µ-conotoxins, µ-BuIIIB and µ-SxIIIA, are 50-fold more potent in blocking NaV1.6 from mouse than that from rat. Furthermore, we observed that µ-BuIIIB and µ-SxIIIA are potent blockers of large, myelinated A-fiber compound action potentials (A-CAPs) [but not small, unmyelinated C-fiber CAPs (C-CAPs)] in the sciatic nerve of the mouse (unlike A-CAPs of the rat, previously shown to be insensitive to these toxins). To investigate ß-subunits, we used two synthetic derivatives of the recently discovered µO§-conotoxin GVIIJ that define site 8 of the channel, as previously characterized with cloned rat NaV1- and NaVß-subunits expressed in Xenopus laevis oocytes, where it was shown that µO§-GVIIJ is a potent inhibitor of several NaV1-isoforms and that coexpression of NaVß2 or -ß4 (but not NaVß1 or -ß3) totally protects against block by µO§-GVIIJ. We report here the effects of µO§-GVIIJ on 1) sodium currents of mouse NaV1.6 coexpressed with various combinations of NaVß-subunits in oocytes; 2) A- and C-CAPs of mouse and rat sciatic nerves; and 3) sodium currents of small and large neurons dissociated from rat dorsal root ganglia. Our overall results lead us to conclude that action potentials in A-fibers of the rodent sciatic nerve are mediated primarily by NaV1.6 associated with NaVß2 or NaVß4.


Assuntos
Potenciais de Ação/fisiologia , Conotoxinas/administração & dosagem , Ativação do Canal Iônico/fisiologia , Potenciais da Membrana/fisiologia , Canais de Sódio Disparados por Voltagem/metabolismo , Potenciais de Ação/efeitos dos fármacos , Animais , Células Cultivadas , Conotoxinas/química , Relação Dose-Resposta a Droga , Ativação do Canal Iônico/efeitos dos fármacos , Masculino , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Oócitos , Subunidades Proteicas , Ratos , Ratos Sprague-Dawley , Sódio/metabolismo , Relação Estrutura-Atividade , Bloqueadores do Canal de Sódio Disparado por Voltagem , Canais de Sódio Disparados por Voltagem/química , Xenopus laevis
13.
Bioorg Med Chem Lett ; 24(19): 4672-4677, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25193233

RESUMO

Over-expression of the Bcl-2 anti-apoptotic proteins is closely related to tumorigenesis and associated with drug resistance. Here we report that luteolin, a main substance found in Flos Chrysanthemi, directly binds to and shows inhibitory activity against the Bcl-2 protein. We studied the binding mode of luteolin and its derivatives with target proteins, their structure-activity relationship, and their effect on the human leukemia cell line HL-60. The results suggest that luteolin and its derivatives with a benzyl group introduced to the B ring, are new small molecule Bcl-2 protein inhibitors, and their anti-tumor activity is likely related to their effect on the Bcl-2 protein.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Chrysanthemum/química , Flores/química , Luteolina/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HL-60 , Humanos , Luteolina/química , Luteolina/isolamento & purificação , Modelos Moleculares , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/isolamento & purificação , Relação Estrutura-Atividade
14.
Proc Natl Acad Sci U S A ; 108(25): 10302-7, 2011 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-21652775

RESUMO

Voltage-gated sodium channels (VGSCs) are important for action potentials. There are seven major isoforms of the pore-forming and gate-bearing α-subunit (Na(V)1) of VGSCs in mammalian neurons, and a given neuron can express more than one isoform. Five of the neuronal isoforms, Na(V)1.1, 1.2, 1.3, 1.6, and 1.7, are exquisitely sensitive to tetrodotoxin (TTX), and a functional differentiation of these presents a serious challenge. Here, we examined a panel of 11 µ-conopeptides for their ability to block rodent Na(V)1.1 through 1.8 expressed in Xenopus oocytes. Although none blocked Na(V)1.8, a TTX-resistant isoform, the resulting "activity matrix" revealed that the panel could readily discriminate between the members of all pair-wise combinations of the tested isoforms. To examine the identities of endogenous VGSCs, a subset of the panel was tested on A- and C-compound action potentials recorded from isolated preparations of rat sciatic nerve. The results show that the major subtypes in the corresponding A- and C-fibers were Na(V)1.6 and 1.7, respectively. Ruled out as major players in both fiber types were Na(V)1.1, 1.2, and 1.3. These results are consistent with immunohistochemical findings of others. To our awareness this is the first report describing a qualitative pharmacological survey of TTX-sensitive Na(V)1 isoforms responsible for propagating action potentials in peripheral nerve. The panel of µ-conopeptides should be useful in identifying the functional contributions of Na(V)1 isoforms in other preparations.


Assuntos
Potenciais de Ação/fisiologia , Conotoxinas/metabolismo , Isoformas de Proteínas/metabolismo , Nervo Isquiático/fisiologia , Bloqueadores dos Canais de Sódio/metabolismo , Canais de Sódio/metabolismo , Animais , Neurotoxinas/metabolismo , Oócitos/citologia , Oócitos/fisiologia , Técnicas de Patch-Clamp , Ratos , Xenopus laevis
15.
Parkinsonism Relat Disord ; 107: 105254, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36584484

RESUMO

INTRODUCTION: Growing evidence has demonstrated dysfunction of the glymphatic system in α-synucleinopathy and related diseases. In this study, we aimed to use diffusion tensor image analysis along the perivascular space (DTI-ALPS) and MRI-visible enlarged perivascular spaces (EPVS) to evaluate glymphatic system function quantitatively and qualitatively and its relationship to clinical scores of disease severity in Parkinson's disease (PD) and essential tremor (ET). METHODS: Overall, 124 patients with PD, 74 with ET, and 106 healthy controls (HC) were enrolled. Two trained neurologists performed quantitative calculations of ALPS on DTI and visual ratings of EPVS on T2-weighted images in the centrum semiovale (CSO), basal ganglia (BG), midbrain, and cerebellum. RESULTS: The ALPS index was lower in patients with PD than in patients with ET (p < 0.001) and HC (p < 0.001). Similarly, patients with PD showed a more severe EPVS burden in the CSO, BG, and midbrain compared to ET and HC. Moreover, the ALPS index was negatively correlated with disease severity in the PD subgroups; however, it did not differ within the ET subgroup. No differences in ALPS or EPVS were observed between the ET and HC groups. CONCLUSION: In conclusion, DTI-ALPS and EPVS both provide neuroimaging evidence of glymphatic system dysfunction in PD, which further supports that PD is an α-synucleinopathy disease, while ET is a cerebellar dysfunction-related disease.


Assuntos
Tremor Essencial , Sistema Glinfático , Doença de Parkinson , Sinucleinopatias , Humanos , Doença de Parkinson/diagnóstico por imagem , Sistema Glinfático/diagnóstico por imagem , Tremor Essencial/diagnóstico por imagem , Neuroimagem , Imageamento por Ressonância Magnética
16.
Biochemistry ; 51(49): 9826-35, 2012 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-23167564

RESUMO

In the preparation of synthetic conotoxins containing multiple disulfide bonds, oxidative folding can produce numerous permutations of disulfide bond connectivities. Establishing the native disulfide connectivities thus presents a significant challenge when the venom-derived peptide is not available, as is increasingly the case when conotoxins are identified from cDNA sequences. Here, we investigate the disulfide connectivity of µ-conotoxin KIIIA, which was predicted originally to have a [C1-C9,C2-C15,C4-C16] disulfide pattern based on homology with closely related µ-conotoxins. The two major isomers of synthetic µ-KIIIA formed during oxidative folding were purified and their disulfide connectivities mapped by direct mass spectrometric collision-induced dissociation fragmentation of the disulfide-bonded polypeptides. Our results show that the major oxidative folding product adopts a [C1-C15,C2-C9,C4-C16] disulfide connectivity, while the minor product adopts a [C1-C16,C2-C9,C4-C15] connectivity. Both of these peptides were potent blockers of Na(V)1.2 (K(d) values of 5 and 230 nM, respectively). The solution structure for µ-KIIIA based on nuclear magnetic resonance data was recalculated with the [C1-C15,C2-C9,C4-C16] disulfide pattern; its structure was very similar to the µ-KIIIA structure calculated with the incorrect [C1-C9,C2-C15,C4-C16] disulfide pattern, with an α-helix spanning residues 7-12. In addition, the major folding isomers of µ-KIIIB, an N-terminally extended isoform of µ-KIIIA identified from its cDNA sequence, were isolated. These folding products had the same disulfide connectivities as µ-KIIIA, and both blocked Na(V)1.2 (K(d) values of 470 and 26 nM, respectively). Our results establish that the preferred disulfide pattern of synthetic µ-KIIIA and µ-KIIIB folded in vitro is 1-5/2-4/3-6 but that other disulfide isomers are also potent sodium channel blockers. These findings raise questions about the disulfide pattern(s) of µ-KIIIA in the venom of Conus kinoshitai; indeed, the presence of multiple disulfide isomers in the venom could provide a means of further expanding the snail's repertoire of active peptides.


Assuntos
Conotoxinas/farmacologia , Dissulfetos/química , Ativação do Canal Iônico , Isomerismo , Canais de Sódio/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Conotoxinas/química , Conotoxinas/genética , Espectrometria de Massas , Ressonância Magnética Nuclear Biomolecular , Oxirredução
17.
J Biol Inorg Chem ; 17(2): 247-61, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21960256

RESUMO

Liriodenine, an oxoaporphine alkaloid with anticancer activity isolated from Zanthoxylum nitidum (rutaceous anticancer traditional Chinese medicine), was selected as a bioactive ligand to react with HAuCl(4) and NaAuCl(4) to afford [LH][AuCl(4)] (1) and [AuCl(3)L] (2), respectively (where L is liriodenine). The structures of 1 and 2 were characterized by IR spectroscopy, electrospray ionization mass spectrometry, (1)H-NMR spectroscopy, and elemental analysis. The single-crystal X-ray diffraction analysis of 1 revealed that it is an ionic compound consisting of protonated liriodenine cation [LH](+) and [AuCl(4)](-) anion. The spectroscopic analysis showed that 2 is a coordination compound, in which one liriodenine coordinates to gold via its 7-N donor. In aqueous solution, 1 is relatively stable, but 2 undergoes rapid hydrolysis. The in vitro cytotoxicity towards five human tumor cell lines shows that 1 and 2 manifest roughly similar biological behavior and appreciable antiproliferative properties, with IC(50) values falling in the 2-16 µM range. The flow-cytometric analysis of 1 and 2 suggests that both compounds induced an S-phase arrest. Compounds 1 and 2 significantly poison topoisomerase I in vitro at low concentration (25 µM or less). DNA binding studies indicate that both 1 and 2 interact with DNA mainly via intercalation between the neighboring base pairs of the DNA double helix. Electrostatic interactions of 1 and 2 with the polyanionic DNA phosphate backbone may reinforce the intercalation because both 1 and 2 are composed of planar cationic species.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Aporfinas/química , Aporfinas/farmacologia , Compostos Organoáuricos/química , Compostos Organoáuricos/farmacologia , Antineoplásicos/síntese química , Aporfinas/síntese química , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , DNA/metabolismo , Humanos , Substâncias Intercalantes/síntese química , Substâncias Intercalantes/química , Substâncias Intercalantes/farmacologia , Medicina Tradicional Chinesa , Neoplasias/tratamento farmacológico , Compostos Organoáuricos/síntese química , Zanthoxylum/química
18.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 30(4): 1056-1062, 2022 Aug.
Artigo em Zh | MEDLINE | ID: mdl-35981362

RESUMO

OBJECTIVE: To observe the expression of helper T cells 17(Th17), interleukin 23 (IL-23) in peripheral blood in patients with acute myeloid leukemia (AML), to analyze the relationship between Th17, IL-23 in peripheral blood and immunophenotype. METHODS: 105 patients with AML in the hospital from January 2019 to January 2021 were prospectively selected as the research subjects, the expression of Th17 and IL-23 in peripheral blood of patients with AML was detected by flow cytometry; immunophenotype was detected and counted. The relationship between the expression of Th17, IL-23 in peripheral blood and immunophenotype of AML patients was analyzed. Draw ROC curve and analyze the predictive value of Th17 and IL-23 expression in peripheral blood to immunophenotype. RESULTS: The immunophenotype results of AML patients showed that myeloid antigen, lymphoid antigen and hematopoietic stem/progenitor cell marker antigen were positive expressed for various antigens in 105 AML patients, in myeloid antigens, CD13+ accounted for the highest proportion (93.33%), in lymphoid antigens, CD56+ accounted for the highest proportion (32.38%), and in hematopoietic stem/progenitor cell marker antigens, CD38+ accounted for the highest proportion (68.57%). The expression of Th17 in peripheral blood of AML patients with CD56+, CD7+, CD34+ and human leukocyte antigen DR+(HLA-DR+) were higher than that of AML patients with CD56-, CD7-, CD34-, HLA-DR-, the expression of IL-23 in peripheral blood of AML patients with CD56+, CD34+ and HLA-DR+ were higher than that of AML patients with CD56-, CD34-, HLA-DR-, the differences were statistically significant (P<0.05); compared the expression of Th17 and IL-23 in peripheral blood between other antibody positive and negative patients, there was no statistical significant difference (P>0.05). Logistic regression analysis showed that the high expression of Th17 in patients with AML was related to the positive expression of CD56, CD7, CD34 and HLA-DR in the detection of immunophenotype, the high expression of IL-23 was related to the positive expression of CD56, CD34 and HLA-DR in the detection of immunophenotype. The ROC curve showed that the AUC of expression levels of Th17 and IL-23 in peripheral blood alone and in combination for predicting CD56+, CD34+, HLA-DR+ and Th17 in peripheral blood for predicting CD7+ were mostly 0.5-0.7, which had certain predictive value, but the predictive performance was low. CONCLUSION: Myeloid antigen, lymphoid antigen and hematopoietic hematopoietic stem/progenitor cell marker antigen are positive expressed for various antigens in AML patients, the high expression of Th17 in peripheral blood of AML patients is related to the positive expression of CD56, CD7, CD34 and HLA-DR in detection of immunophenotyping, the high expression of IL-23 is related to the positive expression of CD56, CD34 and HLA-DR in the detection of immunophenotype.


Assuntos
Subunidade p19 da Interleucina-23/sangue , Interleucina-23 , Leucemia Mieloide Aguda , Antígenos CD34 , Citometria de Fluxo/métodos , Antígenos HLA-DR/análise , Humanos , Imunofenotipagem , Leucemia Mieloide Aguda/genética , Células Th17
19.
Front Neurol ; 13: 811629, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35222248

RESUMO

OBJECTIVE: To analyze the effect of endovascular thrombectomy (EVT) alone vs. EVT after an intravenous (IV) alteplase of ischemic stroke on a patient-reported anxiety/depression, and to identify predictors of patient-reported anxiety/depression by analyzing data from Direct Intraarterial Thrombectomy in Order to Revascularize the patients with Acute Ischemic Stroke with a Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals: a Multicenter Randomized Clinical Trial (DIRECT-MT). METHODS: Patients with acute ischemic stroke (AIS), triggered by a large-vessel occlusion in the anterior circulation, were randomly allocated to undergo an EVT after IV alteplase (combination-therapy group) or an EVT alone (EVT-alone group) at a 1:1 ratio in DIRECT-MT. Patients in both groups were followed up for 90 days (±14 days) after stroke using a structured modified Ranking Scale (mRS), a Barthel Index (BI), and a 5-Dimensional European Quality of Life Scale (EQ-5D-5L). Patients who returned EQ-5D-5L were included. The EQ-5D-5L anxiety/depression dimension was used to analyze the patient-reported anxiety/depression. First, differences in patient-reported anxiety/depression were compared between the combination-therapy group and the EVT-alone group. Then, the baseline and influencing factors between the anxiety/depression group and no anxiety/depression group were analyzed using univariate regression analysis. Finally, variables with p < 0.1 in univariate regression were subjected to multivariable binary regression analysis to screen independent predictors for patient-reported anxiety /depression after ischemic stroke. RESULTS: : Five hundred fifteen patients returned the EQ-5D-5L in Direct-MT. Of these patients, 226 (43.88%) reported a level of anxiety/depression, and about 7% reported a severe or extremely severe anxiety/depression. The patient-reported anxiety/depression in the EVT-alone group was significantly higher than that in the combination-therapy group (48.26% vs. 39.45%, p = 0.04). The clinical outcomes were significantly different between the no Anxiety/Depression Group and the anxiety/depression group (mRS at 90 days:2 vs 3, p < 0.001; BI of 95 or 100 at 90 days: 73.36% vs 42.04%, p < 0.001; EQ-5D-5l utility indexes at 90 days:0.96 vs.57, p < 0.001). Logistic regression analysis showed that allocation to thrombolysis before EVT strategy was inversely associated with anxiety/depression [0.61(0.40, 0.94), p = 0.03], an insular cortex ischemia, and National Institute of Health Strocke Scale (NIHSS) at 7 days were positively associated with anxiety/depression [2.04(1.07, 3.90), p = 0.03; 1.07(1.03, 1.12), p < 0.001]. CONCLUSIONS: Patient-reported anxiety/depression may suggest that there is a benefit to administering intravenous alteplase before EVT. It may also indicate that it is better to provide IV alteplase before EVT, rather than EVT alone according to patient-reported anxiety/depression. Future research should consider not only the motor function impairments but also the patient-reported mental problems as measures of treatment efficacy in patients with stroke (DIRECT-MT ClinicalTrials.gov number, NCT03469206).

20.
J Pharmacol Exp Ther ; 338(2): 687-93, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21586605

RESUMO

Voltage-gated sodium channels (VGSCs) consist of a pore-forming α-subunit and regulatory ß-subunits. Several families of neuroactive peptides of Conus snails target VGSCs, including µO-conotoxins and µ-conotoxins. Unlike µ-conotoxins and the guanidinium alkaloid saxitoxin (STX), which are pore blockers, µO-conotoxins MrVIA and MrVIB inhibit VGSCs by modifying channel gating. µO-MrVIA/B can block Na(v)1.8 (a tetrodotoxin-resistant isoform of VGSCs) and have analgesic properties. The effect of Na(v)ß-subunit coexpression on susceptibility to block by µO-MrVIA/B and STX has, until now, not been reported. Here, we show that ß1-, ß2-, ß3-, and ß4-subunits, when individually coexpressed with Na(v)1.8 in Xenopus laevis oocytes, increased the k(on) of the block produced by µO-MrVIB (by 3-, 32-, 2-, and 7-fold, respectively) and modestly decreased the apparent k(off). Strong depolarizing prepulses markedly accelerated MrVIB washout with rates dependent on ß-subunit coexpression. Thus, coexpression of ß-subunits with Na(v)1.8 can strongly influence the affinity of the conopeptide for the channel. This observation is of particular interest because ß-subunit expression can be dynamic, e.g., ß2-expression is up-regulated after nerve injury (J Neurosci, 25:10970-10980, 2005); therefore, the effectiveness of a µO-conotoxin as a channel blocker could be enhanced by the conditions that may call for its use therapeutically. In contrast to MrVIB's action, the STX-induced block of Na(v)1.8 was only marginally, if at all, affected by coexpression of any of the ß-subunits. Our results raise the possibility that µO-conotoxins and perhaps other gating modifiers may provide a means to functionally assess the ß-subunit composition of VGSC complexes in neurons.


Assuntos
Analgésicos não Narcóticos/farmacologia , Conotoxinas/farmacologia , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/fisiologia , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/metabolismo , Animais , Relação Dose-Resposta a Droga , Feminino , Canal de Sódio Disparado por Voltagem NAV1.8 , Oócitos/metabolismo , Biossíntese Peptídica/efeitos dos fármacos , Ligação Proteica , Subunidades Proteicas/biossíntese , Ratos , Canais de Sódio/fisiologia , Xenopus laevis
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