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BACKGROUND: The most recommended treatment for stage IV EGFR-positive lung cancer is osimertinib monotherapy. The dosage of osimertinib is fixed at 80 mg/day regardless of body surface area (BSA), however some patients withdraw or reduce the dosage due to adverse events (AEs). METHODS: We performed a retrospective cohort study of 98 patients with EGFR mutation-positive non-small cell lung cancer (NSCLC), who received 80 mg osimertinib as the initial treatment. We investigated the impact of BSA on efficacy and safety of osimertinib. RESULTS: The cut-off value of BSA was estimated using the receiver operating characteristics curve, and was determined to be 1.5 m2. There were 44 patients in the BSA < 1.5 group and 54 patients in the BSA ≥ 1.5 group. There was no significant difference in the incidence of AEs (hematologic toxicity of ≥grade 3 or higher, and non-hematologic toxicity of ≥grade 3) between the two groups. However, the incidence of dose reduction due to AEs was significantly higher in the BSA < 1.5 group compared with the BSA ≥ 1.5 group (16 patients vs 5 patients, p = 0.003). The main reasons were fatigue, anorexia, diarrhea, and liver disfunction. Median progression-free survival (PFS) was not significantly different (16.9 months in the BSA < 1.5 group vs 18.1 months in the BSA ≥ 1.5 group, p = 0.869). CONCLUSION: Differences in BSA affected the optimal dose of osimertinib. However, the PFS with osimertinib treatment was not affected by BSA. Therefore, when using osimertinib as an initial treatment for patients with EGFR-mutant NSCLC, dose reduction to control AEs should be considered, especially in the BSA<1.5 group.
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Inotuzumab ozogamicin (IO), a novel therapeutic drug for relapsed or refractory acute lymphoblastic leukemia (RR)(ALL), is a humanized anticluster of differentiation (CD) 22 monoclonal antibody conjugated with calicheamicin that causes DNA single and doublestrand breaks. Although the efficacy of IO is significantly improved compared with that of conventional chemotherapies, the prognosis for RRALL remains poor, highlighting the need for more effective treatment strategies. The present study examined the role of DNA damage repair inhibition using the poly (ADPribose) polymerase (PARP) inhibitors olaparib or talazoparib on the enhancement of the antitumor effects of IO on BALL cells in vitro. The Reh, Philadelphia (Ph)BALL and the SUPB15 Ph+ BALL cell lines were used for experiments. Both cell lines were ~90% CD22+. The halfmaximal inhibitory concentration (IC50) values of IO were 5.3 and 49.7 ng/ml for Reh and SUPB15 cells, respectively. The IC50 values of IO combined with minimally toxic concentrations of olaparib or talazoparib were 0.8 and 2.9 ng/ml for Reh cells, respectively, and 36.1 and 39.6 ng/ml for SUPB15 cells, respectively. The combination index of IO with olaparib and talazoparib were 0.19 and 0.56 for Reh cells and 0.76 and 0.89 for SUPB15 cells, demonstrating synergistic effects in all combinations. Moreover, the addition of minimally toxic concentrations of PARP inhibitors augmented IOinduced apoptosis. The alkaline comet assay, which quantitates the amount of DNA strand breaks, was used to investigate the degree to which DNA damage observed 1 h after IO administration was repaired 6 h later, reflecting successful repair of DNA strand breaks. However, DNA strand breaks persisted 6 h after IO administration combined with olaparib or talazoparib, suggesting inhibition of the repair processes by PARP inhibitors. Adding olaparib or talazoparib thus synergized the antitumor effects of IO by inhibiting DNA strand break repair via the inhibition of PARP.
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Reparo do DNA , Sinergismo Farmacológico , Inotuzumab Ozogamicina , Ftalazinas , Piperazinas , Inibidores de Poli(ADP-Ribose) Polimerases , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Ftalazinas/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Piperazinas/farmacologia , Piperazinas/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Linhagem Celular Tumoral , Reparo do DNA/efeitos dos fármacos , Inotuzumab Ozogamicina/farmacologia , Apoptose/efeitos dos fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Indóis/farmacologiaRESUMO
Critical chain length that divides small molecule crystallization from macromolecular crystallization is an important index in macro-organic chemistry to predict chain-length dependent properties of oligomers and polymers. However, extensive research on crystallization behavior of individual oligomers has been inhibited by difficulties in their synthesis and crystallization. Here, we report on the determination of critical chain length of macromolecular crystallization for structurally flexible polyketones consisting of 3,3-dimethylpentane-2,4-dione. Discrete polyketone oligomers were synthesized via stepwise elongation up to 20-mer. Powder and single crystal X-ray diffraction showed that the critical chain length for polyketones existed at an unexpectedly short chain length, 5-mer. While shorter oligomers adopted unique conformations and packing structures in the solid state, higher oligomers longer than 4-mer produced helical conformations and similar crystal packing. The critical chain length helped with understanding the inexplicable changes in melting point in the shorter chain length region resulting from chain conformations and packing styles.
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The application of ultraviolet-B (UV-B) irradiation to supplement visible light as an elicitor to increase bioactive compounds under controlled conditions is increasing. This study aimed to evaluate the effects of UV-B dose and wavelength region (280−300 and 300−320 nm) on the morphological, physiological, and biochemical responses of canola plants (Brassica napus L.). Canola plants (17 days after sowing) were subjected to various UV-B intensities (i.e., 0.3, 0.6, and 0.9 W m−2) and were divided into cut and non-cut treatments for each UV treatment. Plant growth parameters exhibited different trends based on the treated UV irradiation intensity. Plant growth gradually decreased as the UV irradiation intensity and exposure time increased. Despite the same UV irradiation intensity, plant response varied significantly depending on the presence or absence of a short-wavelength cut filter (<300 nm). Canola plants suffered more leaf damage in nonfilter treatments containing shorter wavelengths (280−300 nm). UV treatment effectively activates the expression of secondary metabolite biosynthetic genes, differing depending on the UV irradiation intensity. Our results suggest that both UV irradiation intensity and wavelength should be considered when enhancing antioxidant phytochemicals without inhibiting plant growth in a plant factory with artificial light.
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Concentrations of 13 phase-partitioned polycyclic aromatic hydrocarbons (PAHs) in seawater were monitored monthly off Oki Island, Japan, during 2015-2019 to elucidate seasonal variations, main source, and transport pathways of PAHs in the southwestern Sea of Japan. Total PAH (dissolved plus particulate) concentrations in surface seawater at 36°09.0'N, 133°17.3'E (site OK) were in the range 0.49-9.36â¯ngâ¯L-1 (mean 2.77, SD 2.05â¯ngâ¯L-1) with higher levels in summer-autumn, an order of magnitude lower than those in the East China Sea during 2005 and 2009-2011 and about one-third of those recorded in the Sea of Japan in 2008 and 2010. The main sources of dissolved and particulate PAHs were combustion products. Increasing dissolved PAH levels during July-October indicate that the area around southern Oki Island is impacted by PAH-rich summer continental-shelf water transported by the Tsushima Warm Current flowing from the East China Sea.
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Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , China , Carvão Mineral , Monitoramento Ambiental , Japão , Hidrocarbonetos Policíclicos Aromáticos/análise , Estações do Ano , Poluentes Químicos da Água/análiseRESUMO
As specific inhibitors of the gastric proton pump, responsible for gastric acidification, K+-competitive acid blockers (P-CABs) have recently been utilized in the clinical treatment of gastric acid-related diseases in Asia. However, as these compounds have been developed based on phenotypic screening, their detailed binding poses are unknown. We show crystal and cryo-EM structures of the gastric proton pump in complex with four different P-CABs, tegoprazan, soraprazan, PF-03716556 and revaprazan, at resolutions reaching 2.8 Å. The structures describe molecular details of their interactions and are supported by functional analyses of mutations and molecular dynamics simulations. We reveal that revaprazan has a novel binding mode in which its tetrahydroisoquinoline moiety binds deep in the cation transport conduit. The mechanism of action of these P-CABs can now be evaluated at the molecular level, which will facilitate the rational development and improvement of currently available P-CABs to provide better treatment of acid-related gastrointestinal diseases.
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Inibidores da Bomba de Prótons , Bombas de Próton , Ácido Gástrico/metabolismo , Potássio/metabolismo , Inibidores da Bomba de Prótons/metabolismo , Inibidores da Bomba de Prótons/farmacologia , Bombas de Próton/metabolismo , EstômagoRESUMO
Neuropsychiatric systemic lupus erythematosus (NPSLE) with cerebral vasculitis is rare, and its prognosis is unfavorable. High-dose glucocorticoids and cyclophosphamide are widely used for the treatment of NPSLE, but cyclophosphamide has a risk of cervical intraepithelial neoplasia and ovarian insufficiency, which may discourage its use in young women. We experienced a case of NPSLE with cerebral vasculitis and lupus nephritis that responded successfully to glucocorticoids and mycophenolate mofetil (MMF). MMF might be a treatment option for NPSLE without concern for reproductive toxicity. However, there are only a few reports on the efficacy of MMF in NPSLE, and further investigations are needed.
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Lúpus Eritematoso Sistêmico , Nefrite Lúpica , Vasculite Associada ao Lúpus do Sistema Nervoso Central , Ciclofosfamida/uso terapêutico , Feminino , Glucocorticoides/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Nefrite Lúpica/complicações , Nefrite Lúpica/tratamento farmacológico , Vasculite Associada ao Lúpus do Sistema Nervoso Central/complicações , Vasculite Associada ao Lúpus do Sistema Nervoso Central/tratamento farmacológico , Ácido Micofenólico/uso terapêuticoRESUMO
Clobetasol propionate ointment (CLPO) formulations have been classified as members of the "strongest" steroidal efficacy group, with eight of these formulations currently marketed in Japan. Evaluations of pharmaceutical properties of each formulation revealed three classification types: droplet dispersion type containing propylene glycol (PG) and surfactant, type with surfactant but not PG, and other types. These rheological properties were diverse, with no correlation found between viscosity and ointment type. However, when CLPO and six types of heparinoid oil-based cream (HPOC) formulation mixtures were stored at 37â, a liquid layer was observed starting at 24 h for one CLPO formulation in which polyoxyethylene hydrogenated castor oil 40 was used as a surfactant out of the four droplet-dispersion type ointments and two low-viscosity HPOC formulations. In contrast, one other type of CLPO formulation that contained a surfactant with polysorbate 80, but not PG, exhibited a liquid layer for all of HPOC formulations. This suggests that CLPO formulations that contain a surfactant with a high hydrophilic-lipophilic balance value are likely to generate a liquid layer for mixtures containing HPOC formulation. The present results demonstrate that not only the pharmaceutical properties of the eight CLPO formulations differ from one another, but also that the stabilities of HPOC formulation mixtures are significantly different. Therefore, pharmacists need to focus on inactive as well as active pharmaceutical ingredients to select formulations that patients will want to use, in addition to successfully treating their pathological conditions.
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Heparinoides , Clobetasol , Excipientes , Humanos , Japão , PomadasRESUMO
A systematic investigation of the polymerization of representative diphenylacetylenes with TaCl5 and cocatalysts suggested that low-valent Ta species, which are formed by in situ reduction of TaCl5 by the cocatalysts, are involved in the polymerization and that the polymerization reaction proceeds by an insertion ring expansion mechanism via the formation of tantalacyclopentadiene intermediates, rather than the previously considered metathesis mechanism. This polymerization mechanism indicates the production of unprecedented cis-stereoregular cyclic poly(diphenylacetylene)s. Indeed, the possibilities of a cyclic structure and high cis-stereoregularity of the resulting polymers were reasonably supported by the results of their detailed atomic force microscopy (AFM) and NMR analyses, respectively.
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Following a rubella outbreak in 2011, Vietnam implemented a mass measles-rubella vaccination campaign for children aged 1-14 years in 2014-2015, further expanding the target age to 16-17 years in 2016; routine vaccination was introduced in 2014. However, there was concern that a substantial proportion of women of child-bearing age were still susceptible to rubella, with the fear of congenital rubella emergence. Thus, we conducted a prospective cohort study in Nha Trang, Vietnam, from 2017-2018 to investigate pregnant women's susceptibility to rubella infection, the incidence of congenital rubella infection, and factors associated with susceptibility. Cord blood was tested for rubella-specific immunoglobulin M (IgM) and IgG; neonatal saliva and cord blood specimens were examined for rubella-RNA. We analyzed 2013 mother-baby pairs. No baby was rubella-IgM or rubella-RNA positive. Overall, 20.4% of mothers were seronegative (95% confidence interval, 18.6%-22.1%). The seronegativity was significantly low among mothers aged <35 years. We found that maternal age groups of 20-24 and 25-29 years, and the lack of self-reported vaccination history were significantly associated with seronegativity. Many pregnant women who were not covered by the vaccination campaign are still at risk of rubella infection.
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Mães , Rubéola (Sarampo Alemão) , Anticorpos Antivirais , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Gravidez , Estudos Prospectivos , Rubéola (Sarampo Alemão)/epidemiologia , Rubéola (Sarampo Alemão)/prevenção & controle , Vacina contra Rubéola , Estudos Soroepidemiológicos , Vietnã/epidemiologiaRESUMO
In this paper Pd-catalyzed intramolecular dehydrogenative C(sp3)-H amidation for the synthesis of isoindolinones is described. This method features the use of a Pd/C catalyst and the addition of a stoichiometric amount of oxidant is not necessary. A mechanistic study suggested the possible formation of H2 gas during the reaction.
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The common marmoset is an important primate species used in drug metabolism studies. However, glutathione S-transferases (GSTs), essential drug-metabolizing enzymes involved in the conjugation of various endogenous and exogenous substrates, have not been identified or characterized in this species. In this study, 20 GSTs [including 3 microsomal GSTs (MGSTs)] were identified and characterized in marmosets. Marmoset GSTs had amino acid sequences highly identical (86-99%) to human GSTs, except for GSTA4L, which had lower identities (59-62%) with human GSTAs. Phylogenetic analysis revealed that marmoset GSTs were closely clustered with their human counterparts. Marmoset GSTs had gene and genomic structures generally similar to their human counterparts, with some differences in GSTA, GSTM, and GSTT clusters. Marmoset GST mRNAs exhibited distinct tissue expression patterns: GSTA1, GSTA3, GSTA4L, GSTK1, GSTT1, GSTZ1, and MGST1 mRNAs were expressed most abundantly in liver. Other GST mRNAs were expressed most abundantly in small intestine, lung, brain, or kidney. Expression of GSTT4 and GSTT4L mRNAs was detected only in testis. Among all 20 marmoset GST mRNAs, the most abundant mRNAs were GSTA1 mRNA in liver, small intestine, and kidney; GSTM3 mRNA in testis; and MSGT3 mRNA in brain and lung. All 20 GSTs mediated the conjugation of GST substrates 1-chloro-2,4-dinitrobenzene; 1,2-epoxy-3-(p-nitrophenoxy)propane; styrene 7,8-oxide; and/or 1-iodohexane, but with different activity levels. Kinetic analyses showed that marmoset GSTM2/GSTM5 and GSTM5/GSTT1 effectively conjugated styrene 7,8-oxide and 1-iodohexane, respectively, with the highest affinity. These results suggest that the 20 newly identified marmoset GSTs were functional drug-metabolizing enzymes able to conjugate typical GST substrates.
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Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Sequência de Aminoácidos , Animais , Callithrix , Feminino , Humanos , Masculino , Filogenia , Especificidade da EspécieRESUMO
Albumin has reportedly enhanced cytochrome P450 (P450)-mediated drug oxidation rates in human liver microsomes. Consequently, measurements of clearances and fractions metabolized could vary depending on the experimental albumin concentrations used. In this study, the oxidation rates of diclofenac and warfarin by human liver microsomes were significantly enhanced in the presence of 0.10% (w/v) bovine serum albumin, whereas those of tolbutamide and phenytoin required 1.0% and 2.0% of albumin for significant enhancement. Values of the fractions metabolized by P450 2C9 for four substrates did not markedly change in the presence of albumin at the above-mentioned concentrations. The oxidation rates of bupropion, omeprazole, chlorzoxazone and phenacetin in human liver microsomes were reportedly enhanced by 0.5%, 1%, 2% and 2% of albumin, respectively. Analysis of reported intrinsic clearance values and suitable albumin concentrations for the currently analyzed substrates and the reported substrates revealed an inverse correlation, with warfarin as an outlier. Suitable albumin concentrations were multivariately correlated with physicochemical properties, that is, the plasma unbound fractions, octanol-water partition coefficient and acid dissociation constant (r = 0.98, p<.0001, n = 10). Therefore, multiple physicochemical properties may be determinants of suitable albumin concentrations for substrate oxidations in human liver microsomes.
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Citocromo P-450 CYP2C9/química , Microssomos Hepáticos/enzimologia , Modelos Químicos , Preparações Farmacêuticas/química , Farmacocinética , Albumina Sérica Humana/química , Citocromo P-450 CYP2C9/metabolismo , Humanos , Oxirredução , Albumina Sérica Humana/metabolismoRESUMO
Glutathione S-transferase (GST) is a family of important drug-metabolizing enzymes, conjugating endogenous and exogenous compounds. Genetic polymorphisms result in the inter-individual variability of GST activity in humans. Especially, human GSTT1 and GSTT2 null alleles are associated with toxicity and various cancers derived from chemicals. Cynomolgus macaque, a nonhuman primate species widely used in drug metabolism studies, has molecular and enzymatic similarities of GSTs to the human orthologs; however, genetic polymorphisms have not been investigated in this species. In this study, resequencing of GSTT1 and GSTT2 in 64 cynomolgus and 32 rhesus macaques found 15 nonsynonymous variants and 1 nonsense variant for GSTT1 and 15 nonsynonymous variants for GSTT2. Some of these GSTT variants were distributed differently in Indochinese and Indonesian cynomolgus macaques and rhesus macaques. For analysis of functional relevance of the GSTT variants, 1-iodohexane and dibromomethane were determined to be suitable substrates for cynomolgus GSTT1 and GSTT2. However, the conjugation activities were roughly correlated with GSTT protein levels immunochemically quantified in cynomolgus liver samples with no statistical significances, implying the contributions of the GST genetic variants. Among the GSTT1 variants identified, the animals carrying R76C and D125G mutations showed lower conjugation activities toward dibromomethane than those of the wild-type in liver cytosolic fractions. Moreover, the recombinant R76C/D125G and D125G GSTT variant proteins showed significantly lower 1-iodohexane or dibromomethane conjugation activities than those of the wild-type protein. Therefore, inter-animal variability of GSTT-dependent drug metabolism is at least partly accounted for by GSTT1 and possibly GSTT2 variants in cynomolgus and rhesus macaques.
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Glutationa Transferase/genética , Macaca fascicularis/genética , Animais , Códon sem Sentido , Glutationa Transferase/metabolismo , Hidrocarbonetos Bromados/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Cinética , Fígado/enzimologia , Macaca mulatta/genética , Polimorfismo Genético , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por SubstratoRESUMO
Tributyltin (TBT), a common organotin environmental pollutant, has been widely used as a component of marine antifouling paints. We previously reported that exposure to TBT inhibits the expression and DNA binding of nuclear respiratory factor-1 (NRF-1) and causes neurotoxicity. In the present study, we focused on the epigenetic effects of TBT and investigated whether TBT decreases NRF-1 expression via epigenetic modifications in SH-SY5Y human neuroblastoma cells. First, we found that exposure to 300 nM TBT decreases NRF-1 expression. We examined epigenetic changes induced by TBT, and showed that TBT causes hypermethylation of the NRF-1 promoter region, increases the amount of methyl-CpG-binding protein 2 (MeCP2) bound to the NRF-1 promoter, and alters the expression of DNA methyltransferases and ten-eleven translocation (TET) demethylation enzymes. These results suggest that epigenetic changes play an important role in regulation of NRF-1 expression. Next, we investigated effect of NRF-1 expression decrease on cells, and TBT reduces mitochondrial membrane potential and overexpression of NRF-1 rescued this reduction in membrane potential. Thus, we suggested that NRF-1 is important for maintaining mitochondrial membrane potential. Our study indicates that TBT causes epigenetic changes such as hypermethylation, which increases recruitment of MeCP2 to the NRF-1 promoter and probably lead to decreased of NRF-1 expression and mitochondrial membrane potential. Therefore, this research provides new evidence of the epigenetic action caused by organotin.
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Metilação de DNA , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Potencial da Membrana Mitocondrial , Neuroblastoma/genética , Fator 1 Nuclear Respiratório/genética , Compostos de Trialquitina/farmacologia , Sobrevivência Celular , Genoma Humano , Humanos , Proteína 2 de Ligação a Metil-CpG/genética , Proteína 2 de Ligação a Metil-CpG/metabolismo , Neuroblastoma/tratamento farmacológico , Neuroblastoma/patologia , Fator 1 Nuclear Respiratório/metabolismo , Regiões Promotoras Genéticas , Sulfitos , Células Tumorais CultivadasRESUMO
BACKGROUND: Respiratory rehabilitation reduces breathlessness from patient with respiratory dysfunction. Chest expansion score, which represents the circumference magnitude of the thoracic cage, is used for a target when treating patients with respiratory disease. However, it is often difficult for patients to understand the changes in the respiratory status and be motivated for therapy continuously. We developed a new measurement system with biofeedback named BREATH which shows chest expansion scores in real time. The purpose of this study was to determine the reliability and validity of the novel system in advance of clinical application. METHODS: Three evaluators measured chest expansion in 33 healthy individuals using tape measure, which is used for the measurement traditionally, and BREATH. The wire for BREATH system was threaded over the thoracic continuously and the data was recorded automatically; whereas the tape was winded and measured each maximal expiration and inspiration timing by evaluator. All participants were performed both measurement simultaneously for three times during deep breath. In this study, we studied chest expansion score without using biofeedback data of BREATH to check the validity of the result. To confirm intra- and inter-evaluator reliability, we computed intra-class correlations (ICCs). We used Pearson's correlation coefficient to evaluate the validity of measurement result by BREATH with reference to the tape measure results. RESULTS: The average (standard deviation) chest expansion scores for all, men and women by the tape measure were 5.53 (1.88), 6.40 (1.69) and 5.22 (1.39) cm, respectively, and those by BREATH were 3.89 (2.04), 4.36 (1.83) and 2.89 (1.66) cm, respectively. ICC within and among the three evaluators for BREATH and the tape measure were 0.90-0.94 and 0.85-0.94 and 0.85 and 0.82, respectively. The correlation coefficient between the two methods was 0.76-0.87. CONCLUSION: The novel measurement system, BREATH, has high intra- and inter-evaluator reliabilities and validity; therefore it can lead us more effective respiratory exercise. Using its biofeedback data, this system may help patients with respiratory disease to do exercises more efficiently and clinicians to assess the respiratory exercise more accurately.
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Biorretroalimentação Psicológica/métodos , Exercícios Respiratórios/métodos , Fenômenos Fisiológicos Respiratórios , Doenças Respiratórias/reabilitação , Adulto , Biorretroalimentação Psicológica/instrumentação , Exercícios Respiratórios/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Tórax , Adulto JovemRESUMO
Gymnopilin is one of the substances produced by the hallucinogenic mushroom, Gymnopilus junonius. In this study, we examined effects of gymnopilins purified from wild fruiting bodies of G. junonius on contractile activity of aorta preparations and blood pressure in rats. Gymnopilins at lower concentrations than 5 mg/mL did not evoke contraction of helical strips of the thoracic aorta. In contrast, gymnopilins (5 mg/mL) applied to the aorta strips pre-contracted by norepinephrine (100 nM) caused relaxation. This relaxing action did not depend on the activity of the endothelium cells. The relaxing effect of 5-mg/mL gymnopilins was observed in aorta strips contracted by angiotensin II (10 nM) and the high K+ solution (60 mM). Moreover, the adenylyl cyclase inhibitor, SQ-22536, significantly inhibited the relaxing effect of gymnopilins at 1 mg/mL on the norepinephrine-contracted strips. These results suggested that gymnopilins acted directly on smooth muscle cells of the aorta and activated the cAMP-dependent cascade to cause the vasodilation. Paradoxically, gymnopilins injection into the jugular vein transiently increased blood pressure without affecting the heart rate. This result suggests that gymnopilins increase cardiac output and/or tension of the artery through the excitation of the vasomotor nerve that overcame the direct relaxing effect on the vascular smooth muscle.
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Basidiomycota/química , Produtos Biológicos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Meglutol/análogos & derivados , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Terpenos/farmacologia , Vasodilatação/efeitos dos fármacos , Adenina/análogos & derivados , Adenina/farmacologia , Inibidores de Adenilil Ciclases , Angiotensina II/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , AMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Carpóforos , Frequência Cardíaca/efeitos dos fármacos , Veias Jugulares/efeitos dos fármacos , Masculino , Meglutol/farmacologia , Músculo Liso Vascular/fisiologia , Norepinefrina/farmacologia , Potássio/farmacologia , Ratos , Ratos WistarRESUMO
Gymnopilus junonius is a widely spread mushroom in Japan and well known as a hallucinogenic mushroom. Gymnopilin was purified from the fruiting body of G. junonius and was reported to act on the spinal cord and depolarize motoneurons. This is the only evidence that gymnopilin has a biological effect on animals and no mechanism of the action has been determined at all. In this study, we examined effects of gymnopilin on intracellular Ca(2+) concentrations ([Ca(2+)](i)) of cultured cells isolated from the dorsal root ganglion (DRG) of the rat. The cell culture consisted of neurons and non-neuronal cells. Gymnopilin increased [Ca(2+)](i) in both the types of cells. The gymnopilinevoked [Ca(2+)](i) rise in the non-neuronal cells was inhibited by cyclopiazonic acid and U-73122, inhibitors of Ca(2+)-ATPase of the intracellular Ca(2+) store and phospholipase C, respectively, but not by removal of extracellular Ca(2+). These results indicate that gymnopilin activated phospholipase C and mobilize Ca(2+) from the intracellular Ca(2+) store in non-neuronal cells from the DRG. This is the first report to show that gymnopilin directly acts on cells isolated from the mammalian nervous system.
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Agaricales/química , Sinalização do Cálcio/efeitos dos fármacos , Ativadores de Enzimas/farmacologia , Gânglios Espinais/citologia , Meglutol/análogos & derivados , Neuroglia/efeitos dos fármacos , Terpenos/farmacologia , Animais , Células Cultivadas , Estrenos/farmacologia , Masculino , Meglutol/farmacologia , Neuroglia/metabolismo , Pirrolidinonas/farmacologia , Ratos , Ratos Wistar , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Fosfolipases Tipo C/antagonistas & inibidores , Fosfolipases Tipo C/metabolismoRESUMO
UNLABELLED: The human ether-a-go-go-related gene (hERG) encodes the α subunit of the potassium current I(Kr), which plays a pivotal role in cardiac action potential repolarization. Inherited mutations of this gene cause Long QT syndrome type 2. hERG expression is altered by several types of drugs as well as by temperature. Heat shock protein 70 (Hsp70) and Heat shock cognate protein 70 (Hsc70) have reciprocal effects on hERG proteins. We examined the effects of poisonous mushrooms on hERG protein expression and its channel function. METHODS: We evaluated the effects of several types of poisonous mushrooms on the expression and function of wild-type hERG by Western blotting, reverse transcription polymerase chain reaction (PCR), and patch clamping in transfected HEK293 cells and mouse HL-1 cardiomyocytes. RESULTS: Extracts of Gymnopilus junonius (junonius) increased expression of both hERG and Hsp70 in HEK293 cells with concomitant decrease in Hsc70, whereas extracts of Amanita ibotengutake (ibotengutake) decreased hERG proteins with increase in Hsc70. Knockdown of Hsp70 and Hsc70 by small interfering RNA abolished the effects of the two mushrooms on hERG, respectively. Certain fractions of junonius increased expression of hERG proteins. hERG currents were increased by extracts of junonius, resulting in shortening of action potential duration (APD). In contrast, hERG currents were decreased and APD was prolonged by extracts of ibotengutake. CONCLUSION: junonius enhanced the expression and function of hERG by increasing Hsp70 and decreasing Hsc70. Ibotengutake decreased hERG expression via increase in Hsc70. Constituents of junonius may have the potential for use in treatment of arrhythmia.