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1.
Am J Pathol ; 192(7): 1028-1052, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35460614

RESUMO

Diabetic nephropathy (DN), once manifested, is unlikely to completely recover. Factors that influence DN progression were explored by investigating the process of glomerulosclerosis and interstitial fibrosis and chronological changes in glucose, albuminuria, hyperfiltration, and expressions of sodium-glucose cotransporter 2 (SGLT2) and hypoxia-inducible factors (HIFs) up to 50 weeks in inducible cAMP early repressor transgenic mice, a model of severe DN. Long-term intervention with the SGLT2 inhibitor canagliflozin or islet transplantation or heminephrectomy was used. Inducible cAMP early repressor transgenic mice exhibited progressive diabetic glomerulosclerosis and mild interstitial fibrosis, and expressed extensive HIF-1α and HIF-2α in glomerulus and tubules, with sustained hyperfiltration up to 50 weeks. Canagliflozin ameliorated glomerulosclerosis/interstitial fibrosis gradually and reduced HIF overexpression. Islet-transplanted mice exhibited no amelioration. None of the heminephrectomized diabetic mice survived the hyperfiltration overload, but all of the canagliflozin-treated mice survived with re-expressions of HIF-1α and HIF-2α. These results suggest that persistent glomerular hyperfiltration might initiate glomerular injury, and persistent overexpression of HIFs could promote the development of glomerulosclerosis and interstitial fibrosis. Canagliflozin attenuated both changes. Oxidative stress or hypoxia was undetectable in this model. The abnormal expression of HIF-1α and HIF-2α may be a potential therapeutic target for preventing glomerulosclerosis and interstitial fibrosis.


Assuntos
Diabetes Mellitus Experimental , Nefropatias Diabéticas , Inibidores do Transportador 2 de Sódio-Glicose , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Canagliflozina , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/metabolismo , Fibrose , Glucose , Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Camundongos , Camundongos Transgênicos , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia
2.
Bioorg Med Chem Lett ; 80: 129125, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36621553

RESUMO

Lankamycin, a macrolide antibiotic produced by Streptomyces rochei 7434AN4, exhibits a moderate antimicrobial activity and acts as a synergistic pair with carbocyclic antibiotic lankacidin C by binding to the ribosome exit tunnel. Its biosynthetic gene (lkm) cluster (orf24-orf53) is located on the largest plasmid pSLA2-L (210,614 bp). Our group possesses a variety of lankamycin derivatives and macrolide-modification enzymes including P450 enzymes and glycosyltransferases, which may lead to expand the chemical library of bioactive macrolides. Here we constructed a mutant of a 3-ketoreductase gene lkmCVI (orf42) involved in d-chalcose biosynthesis, and its metabolite was isolated and structure-elucidated. Accumulation of novel lankamycin derivative harboring a branched-chain deoxysugar, 5-O-(4',6'-dideoxy-3'-C-acetyl-d-ribo-hexopyranosyl)-3-O-(4″-O-acetyl-l-arcanosyl)-lankanolide, indicated that LkmCVI acts as a gate keeper enzyme for d-chalcose synthesis in lankamycin biosynthesis.


Assuntos
Antibacterianos , Açúcares , Antibacterianos/farmacologia , Macrolídeos/farmacologia , Família Multigênica
3.
J Nat Prod ; 86(9): 2185-2192, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37624992

RESUMO

A triple mutant (strain KA57) of Streptomyces rochei 7434AN4 produces an azoxy-alkene compound, KA57A, which was not detected in a parent strain or other single and double mutants. This strain accumulated several additional minor components, whose structures were elucidated. HPLC analysis of strain KA57 indicated the presence of two UV active components (KA57D1 and KA57D2) as minor components. They exhibited a maximum UV absorbance at 218 nm, whereas a UV absorbance of azoxy-alkene KA57A was detected at 236 nm, suggesting that both KA57D1 and KA57D2 contain a different chromophore from KA57A. KA57D1 has a molecular formula of C12H22N2O2, and NMR analysis revealed KA57D1 is a novel hydrazide-alkene compound, (Z)-N-acetyl-N'-(hex-1-en-1-yl)isobutylhydrazide. Labeling studies indicated that nitrogen Nß of KA57D1 is derived from l-glutamic acid, and the isobutylamide unit (C-1 to C-3, 2-Me, and Nα) originates from valine. KA57D2 has a molecular formula of C13H24N2O2, and its structure was determined to be (Z)-N-acetyl-N'-(hex-1-en-1-yl)-2-methylbutanehydrazide, in which a 2-methylbutanamide unit was shown to originate from isoleucine. Different biogenesis of the Nα atom (l-serine for KA57A, l-valine for KA57D1, and l-isoleucine for KA57D2) indicates the relaxed substrate recognition for nitrogen-nitrogen bond formation in the biosyntheses of KA57A, KA57D1, and KA57D2.


Assuntos
Aminoácidos , Streptomyces , Aminoácidos/metabolismo , Alcenos , Streptomyces/genética , Streptomyces/metabolismo
4.
Biosci Biotechnol Biochem ; 87(4): 395-410, 2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36592962

RESUMO

The tobacco BY-2 cell line is one of the most utilized plant cell lines. After long-term culture, the cells turn brown to black, but the causal pigment is unknown. We successfully isolated a blackish-brown pigment from BY-2 cells cultured for 3 weeks. Morphological and spectroscopic analyses indicated that the pigment had similar features to a melanin-like substance reported previously. Furthermore, physicochemical analyses revealed that this pigment possessed most of the properties of melanin-like pigments. In addition, the high nitrogen content suggested that it differed from common plant melanins classified as allomelanins, suggesting a novel eumelanin-like pigment: "BY2-melanin". This is the first example showing that eumelanin-like pigments are produced in the cultures of plant cells for which the accumulation of melanin has not been reported. This tobacco BY-2 cell culture technique may represent a customizable and sustainable alternative to conventional melanin production platforms, with significant potential for industrial and pharmacological applications.


Assuntos
Melaninas , Nicotiana , Linhagem Celular , Nicotiana/genética , Nicotiana/metabolismo
5.
Biosci Biotechnol Biochem ; 87(3): 320-329, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36496162

RESUMO

Kusaya, a traditional Japanese fermented fish product, is known for its high preservability, as it contains natural antibiotics derived from microorganisms, and therefore molds and yeasts do not colonize it easily. In this study, the Streptomyces diastaticus strain TUA-NKU25 was isolated from Kusaya, and its growth as well as the production of antibiotics were investigated. Strain TUA-NKU25 showed advantageous growth characteristics in the presence, but not in the absence, of sodium chloride (NaCl). Antimicrobial assay, high-performance liquid chromatography, and electrospray ionization-mass spectrometry analysis showed that this strain produced surugamide A and uncharacterized antimicrobial compound(s) during growth in the presence of NaCl, suggesting that the biosynthesis of these compounds was upregulated by NaCl. Draft genomic analysis revealed that strain TUA-NKU25 possesses a surugamide biosynthetic gene cluster (sur BGC), although it is incomplete, lacking surB/surC. Phylogenetic analysis of strain TUA-NKU25 and surugamide-producing Streptomyces showed that sur BGC formed a clade distinct from other known groups.


Assuntos
Cloreto de Sódio , Streptomyces , Animais , Filogenia , Streptomyces/genética , Antibacterianos , Família Multigênica
6.
Mol Plant Microbe Interact ; 35(1): 73-84, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34585955

RESUMO

Agrobacterium tumefaciens is a bacterial pathogen that causes crown gall disease on a wide range of eudicot plants by genetic transformation. Besides T-DNA integrated by natural transformation of plant vegetative tissues by pathogenic Agrobacterium spp., previous reports have indicated that T-DNA sequences originating from an ancestral Agrobacterium sp. are present in the genomes of all cultivated sweet potato (Ipomoea batatas) varieties analyzed. Expression of an Agrobacterium-derived agrocinopine synthase (ACS) gene was detected in leaf and root tissues of sweet potato, suggesting that the plant can produce agrocinopine, a sugar-phosphodiester opine considered to be utilized by some strains of Agrobacterium spp. in crown gall. To validate the product synthesized by Ipomoea batatas ACS (IbACS), we introduced IbACS into tobacco under a constitutive promoter. High-voltage paper electrophoresis followed by alkaline silver nitrate staining detected the production of an agrocinopine-like substance in IbACS1-expressing tobacco, and further mass spectrometry and nuclear magnetic resonance analyses of the product confirmed that IbACS can produce agrocinopine A from natural plant substrates. The partially purified compound was biologically active in an agrocinopine A bioassay. A 16S ribosomal RNA amplicon sequencing and meta-transcriptome analysis revealed that the rhizosphere microbial community of tobacco was affected by the expression of IbACS. A new species of Leifsonia (actinobacteria) was isolated as an enriched bacterium in the rhizosphere of IbACS1-expressing tobacco. This Leifsonia sp. can catabolize agrocinopine A produced in tobacco, indicating that the production of agrocinopine A attracts rhizosphere bacteria that can utilize this sugar-phosphodiester. These results suggest a potential role of IbACS conserved among sweet potato cultivars in manipulating their microbial community.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Ipomoea batatas , Microbiota , Agrobacterium tumefaciens , Rizosfera , Fosfatos Açúcares , Nicotiana
7.
Bioorg Med Chem ; 53: 116551, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34883453

RESUMO

We investigated the importance of the δ-lactone ring (C1-C5) in lankacidin C using chemoenzymatic synthesis and computational prediction and assessing biological activity, including antitumor activity. Pyrroloquinoline quinone-dependent dehydrogenase (Orf23) in Streptomyces rochei was used in the chemoenzymatic synthesis of lankacyclinone C, a novel lankacidin C congener lacking the δ-lactone moiety. Orf23 could convert the monocyclic lankacidinol derivatives, lankacyclinol and 2-epi-lankacyclinol, to the C-24 keto compounds, lankacyclinone C and 2-epi-lankacyclinone C, respectively, elucidating the relaxed substrate specificity of Orf23. Computational prediction using molecular dynamics simulations and the molecular mechanics/generalized Born-surface area protocol indicated that binding energy values of all the monocyclic derivatives are very close to those of lankacidin C, which may reflect a comparable affinity to tubulin. Monocyclic lankacidin derivatives showed moderate antitumor activity when compared with bicyclic lankacidins, suggesting that the δ-lactone moiety is less important for antitumor activity in lankacidin-group antibiotics.


Assuntos
Antineoplásicos/farmacologia , Macrolídeos/farmacologia , Simulação de Dinâmica Molecular , Antineoplásicos/química , Antineoplásicos/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Macrolídeos/química , Macrolídeos/metabolismo , Conformação Molecular , Oxirredutases/metabolismo , Streptomyces/enzimologia , Relação Estrutura-Atividade
8.
J Nat Prod ; 85(7): 1867-1871, 2022 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-35694852

RESUMO

A new maniwamycin analogue, maniwamycin G, was isolated from Streptomyces sp. TOHO-M025 as a major product. Maniwamycin G has a molecular formula of C12H22N2O4, and its extensive NMR analysis revealed that maniwamycin G contains a methoxycarbonyl group instead of an amide as found in maniwamycin F. Its C-2 and C-3 configurations were determined to be (2R, 3R) by circular dichroism spectrum and a modified Mosher method, respectively. The biosynthetic origin of maniwamycin G was investigated using isotope-labeled compounds. The carbon source of maniwamycin G is four acetate units (C-1', C-2'; C-3', C-4'; C-5', C-6'; and C-4, C-5) and l-serine (C-1 to C-3). The nitrogen atom attached at C-2 (Nα) originates from serine, whereas the nitrogen atom of a hexen-1-yl amine unit (Nß) is derived from glutamic acid. The quorum-sensing inhibitory activity of maniwamycin G was 2-fold lower than that of maniwamycin F.


Assuntos
Streptomyces , Dicroísmo Circular , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Nitrogênio , Percepção de Quorum , Streptomyces/química
9.
Biosci Biotechnol Biochem ; 86(2): 177-184, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-34849547

RESUMO

Streptomyces antibiotic regulatory proteins (SARPs) are well characterized as transcriptional activators for secondary metabolites in Streptomyces species. Streptomyces rochei 7434AN4 harbors 15 SARP genes, among which 3 were located on a giant linear plasmid pSLA2-L and others were on the chromosome. Some SARP genes were cloned into an integrative thiostrepton-inducible vector pIJ8600, and their recombinants were cultivated. The recombinant of SARP gene, SRO_3163, accumulated a UV-active compound YM3163-A, which was not detected in the parent strain and other SARP recombinants. Its molecular formula was established to be C8H11NO. Extensive NMR analysis revealed that YM3163-A is a novel enamide, 2-(cyclohex-2-en-1-ylidene)acetamide, and its structure was confirmed by chemical synthesis including Horner-Wadsworth-Emmons reaction and ammonolysis.


Assuntos
Streptomyces
10.
Biosci Biotechnol Biochem ; 85(1): 115-125, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33577670

RESUMO

To elucidate the gross lankamycin biosynthetic pathway including two cytochrome P450 monooxygenases, LkmK and LkmF, we constructed two double mutants of P450 genes in combination with glycosyltransferase genes, lkmL and lkmI. An aglycon 8,15-dideoxylankanolide, a possible substrate for LkmK, was prepared from an lkmK-lkmL double mutant, while a monoglycoside 3-O-l-arcanosyl-8-deoxylankanolide, a substrate for LkmF, was from an lkmF-lkmI double mutant. Bioconversion of lankamycin derivatives was performed in the Escherichia coli recombinant for LkmK and the Streptomyces lividans recombinant for LkmF, respectively. LkmK catalyzes the C-15 hydroxylation on all 15-deoxy derivatives, including 8,15-dideoxylankanolide (a possible substrate), 8,15-dideoxylankamycin, and 15-deoxylankamycin, suggesting the relaxed substrate specificity of LkmK. On the other hand, LkmF hydroxylates the C-8 methine of 3-O-l-anosyl-8-deoxylankanolide. Other 8-deoxy lankamycin/lankanolide derivatives were not oxidized, suggesting the importance of a C-3 l-arcanosyl moiety for substrate recognition by LkmF in lankamycin biosynthesis. Thus, LkmF has a strict substrate specificity in lankamycin biosynthesis.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Eritromicina/análogos & derivados , Biotransformação , Eritromicina/biossíntese , Técnicas de Inativação de Genes , Proteínas Recombinantes/metabolismo , Especificidade por Substrato
11.
Antonie Van Leeuwenhoek ; 111(5): 743-751, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29476430

RESUMO

Streptomyces is well characterized by an ability to produce a wide variety of secondary metabolites including antibiotics, whose expression is strictly controlled by small diffusible signaling molecules at nano-molar concentrations. The signaling molecules identified to date are classified into three skeletons; γ-butyrolactones, furans, and γ-butenolides. Accumulated data suggest the structural diversity of the signaling molecules in Streptomyces species and their potential in activating cryptic secondary metabolite biosynthetic pathways. Several genome mining approaches to activate silent biosynthetic gene clusters have been reported for natural product discovery. This review updates recent examples on genetic manipulation including blockage of metabolic pathways together with inactivation of transcriptional repressor genes.


Assuntos
Antibacterianos/biossíntese , Genoma Bacteriano , Genômica/métodos , Redes e Vias Metabólicas/genética , Streptomyces/genética , Streptomyces/metabolismo , Antibacterianos/química , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/metabolismo , Regulação Bacteriana da Expressão Gênica , Família Multigênica/genética , Proteínas Repressoras/genética , Metabolismo Secundário/genética , Transdução de Sinais , Streptomyces/química
12.
Biochem Biophys Res Commun ; 483(1): 674-679, 2017 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-27986566

RESUMO

Perilla frutescens is a dietary leafy herb consumed as a traditional Japanese condiment as well as used for Chinese medicine with anti-inflammatory activity. Here we report a hitherto-unrecognized P. frutescens phytochemical that potently suppresses IgE-mediated type I hypersensitivity reactions. Structural analysis reveals that the purified anti-allergic compound (Perilla-derived methoxyflavanone, PDMF) is identified as 8-hydroxy-5,7-dimethoxyflavanone. PDMF significantly inhibits IgE-mediated histamine release from RBL-2H3 rat basophilic leukemia cells as compared with those seen in known P. frutescens-derived anti-inflammatory polyphenols. We also show that oral administration of PDMF not only suppresses passive cutaneous anaphylaxis, but also prevents allergic rhinitis-like nasal symptoms in a murine model of Japanese cedar pollinosis. Mechanistically, PDMF negatively regulates Akt phosphorylation and intracellular Ca2+ influx, both of which are essential for mast cell secretory granule translocation and its exocytosis upon high-affinity IgE receptor (FcεRI) cross-linking. These results represent PDMF as a new potent anti-allergic phytochemical useful for prevention of IgE-driven hypersensitivity reactions.


Assuntos
Antialérgicos/administração & dosagem , Medicamentos de Ervas Chinesas/administração & dosagem , Flavanonas/administração & dosagem , Hipersensibilidade Imediata/prevenção & controle , Imunoglobulina E/imunologia , Perilla frutescens/química , Plantas Medicinais/química , Rinite Alérgica Sazonal/tratamento farmacológico , Animais , Antialérgicos/química , Antialérgicos/isolamento & purificação , Antialérgicos/farmacologia , Linhagem Celular Tumoral , Cryptomeria/imunologia , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Feminino , Flavanonas/química , Flavanonas/isolamento & purificação , Flavanonas/farmacologia , Liberação de Histamina/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Anafilaxia Cutânea Passiva/efeitos dos fármacos , Ratos , Receptores de IgE/imunologia , Rinite Alérgica Sazonal/prevenção & controle
13.
Biosci Biotechnol Biochem ; 81(5): 938-950, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28388360

RESUMO

The life cycle of the moon jellyfish, Aurelia aurita, alternates between a benthic asexual polyp stage and a planktonic sexual medusa (jellyfish) stage. Transition from polyp to medusa is called strobilation. To investigate the molecular mechanisms of strobilation, we screened for genes that are upregulated during strobilation using the differential display method and we identified aspartylglucosaminidase (AGA), which encodes a lysosomal hydrolase. Similar to AGAs from other species, Aurelia AGA possessed an N-terminal signal peptide and potential N-glycosylation sites. The genomic region of Aurelia AGA was approximately 9.8 kb in length and contained 12 exons and 11 introns. Quantitative RT-PCR analysis revealed that AGA expression increased during strobilation, and was then decreased in medusae. To inhibit AGA function, we administered the lysosomal acidification inhibitors, chloroquine or bafilomycin A1, to animals during strobilation. Both inhibitors disturbed medusa morphogenesis at the oral end, suggesting involvement of lysosomal hydrolases in strobilation.


Assuntos
Aspartilglucosilaminase/genética , Aspartilglucosilaminase/metabolismo , Lisossomos/enzimologia , Reprodução Assexuada , Cifozoários/enzimologia , Cifozoários/fisiologia , Regulação para Cima , Sequência de Aminoácidos , Animais , Aspartilglucosilaminase/química , Sequência de Bases , Clonagem Molecular , Loci Gênicos/genética , Morfogênese , Cifozoários/genética , Cifozoários/crescimento & desenvolvimento , Transcrição Gênica
14.
Mol Microbiol ; 95(5): 846-58, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25495952

RESUMO

Streptomyces rochei 7434AN4 carries three linear plasmids, pSLA2-L (211 kb), pSLA2-M (113 kb) and pSLA2-S (18 kb), their complete nucleotide sequences having been determined. Restriction and sequencing analysis revealed that the telomere sequences at both ends of the linear chromosome are identical to each other, are 98.5% identical to the right end sequences of pSLA2-L and pSLA2-M up to 3.1 kb from the ends and have homology to those of typical Streptomyces species. Mutant 2-39, which lost all the three linear plasmids, was found to carry a circularized chromosome. Sequence comparison of the fusion junction and both deletion ends revealed that chromosomal circularization occurred by terminal deletions followed by nonhomologous recombination. Curing of pSLA2-L from strain 51252, which carries only pSLA2-L, also resulted in terminal deletions in newly obtained mutants. The tap-tpg gene pair, which encodes a telomere-associated protein and a terminal protein for end patching, is located on pSLA2-L and pSLA2-M but has not hitherto been found on the chromosome. These results led us to the idea that the tap-tpg of pSLA2-L or pSLA2-M functions to maintain a linear chromosome in strain 7434AN4. This hypothesis was finally confirmed by complementation and curing experiments of the tap-tpg of pSLA2-M.


Assuntos
Cromossomos Bacterianos/genética , Cromossomos Bacterianos/ultraestrutura , DNA Bacteriano/metabolismo , Plasmídeos/genética , Streptomyces/genética , Sequência de Aminoácidos , Replicação do DNA , Dados de Sequência Molecular , Mutação , Recombinação Genética , Mapeamento por Restrição , Alinhamento de Sequência , Análise de Sequência de DNA , Telômero/genética
15.
J Pharmacol Sci ; 132(4): 255-261, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27889414

RESUMO

We investigated whether structurally different sodium-glucose cotransporter (SGLT) 2 inhibitors, when co-administered with dipeptidyl peptidase-4 (DPP4) inhibitors, could enhance glucagon-like peptide-1 (GLP-1) secretion during oral glucose tolerance tests (OGTTs) in rodents. Three different SGLT inhibitors-1-(ß-d-Glucopyranosyl)-4-chloro-3-[5-(6-fluoro-2-pyridyl)-2-thienylmethyl]benzene (GTB), TA-1887, and canagliflozin-were examined to assess the effect of chemical structure. Oral treatment with GTB plus a DPP4 inhibitor enhanced glucose-induced plasma active GLP-1 (aGLP-1) elevation and suppressed glucose excursions in both normal and diabetic rodents. In DPP4-deficient rats, GTB enhanced glucose-induced aGLP-1 elevation without affecting the basal level, whereas metformin, previously reported to enhance GLP-1 secretion, increased both the basal level and glucose-induced elevation. Oral treatment with canagliflozin and TA-1887 also enhanced glucose-induced aGLP-1 elevation when co-administered with either teneligliptin or sitagliptin. These data suggest that structurally different SGLT2 inhibitors enhance plasma aGLP-1 elevation and suppress glucose excursions during OGTT when co-administered with DPP4 inhibitors, regardless of the difference in chemical structure. Combination treatment with DPP4 inhibitors and SGLT2 inhibitors having moderate SGLT1 inhibitory activity may be a promising therapeutic option for improving glycemic control in patients with type 2 diabetes mellitus.


Assuntos
Inibidores da Dipeptidil Peptidase IV/farmacologia , Peptídeo 1 Semelhante ao Glucagon/sangue , Hipoglicemiantes/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose , Animais , Canagliflozina/farmacologia , Teste de Tolerância a Glucose , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monossacarídeos/farmacologia , Pirazóis/farmacologia , Piridinas/farmacologia , Ratos , Ratos Endogâmicos F344 , Fosfato de Sitagliptina/farmacologia , Transportador 1 de Glucose-Sódio/antagonistas & inibidores , Tiazolidinas/farmacologia
16.
J Pharmacol Exp Ther ; 354(3): 279-89, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26105952

RESUMO

The sodium glucose cotransporter (SGLT) 1 plays a major role in glucose absorption and incretin hormone release in the gastrointestinal tract; however, the impact of SGLT1 inhibition on plasma glucagon-like peptide-1 (GLP-1) levels in vivo is controversial. We analyzed the effects of SGLT1 inhibitors on GLP-1 secretion in normoglycemic and hyperglycemic rodents using phloridzin, CGMI [3-(4-cyclopropylphenylmethyl)-1-(ß-d-glucopyranosyl)-4-methylindole], and canagliflozin. These compounds are SGLT2 inhibitors with moderate SGLT1 inhibitory activity, and their IC50 values against rat SGLT1 and mouse SGLT1 were 609 and 760 nM for phloridzin, 39.4 and 41.5 nM for CGMI, and 555 and 613 nM for canagliflozin, respectively. Oral administration of these inhibitors markedly enhanced and prolonged the glucose-induced plasma active GLP-1 (aGLP-1) increase in combination treatment with sitagliptin, a dipeptidyl peptidase-4 (DPP4) inhibitor, in normoglycemic mice and rats. CGMI, the most potent SGLT1 inhibitor among them, enhanced glucose-induced, but not fat-induced, plasma aGLP-1 increase at a lower dose compared with canagliflozin. Both CGMI and canagliflozin delayed intestinal glucose absorption after oral administration in normoglycemic rats. The combined treatment of canagliflozin and a DPP4 inhibitor increased plasma aGLP-1 levels and improved glucose tolerance compared with single treatment in both 8- and 13-week-old Zucker diabetic fatty rats. These results suggest that transient inhibition of intestinal SGLT1 promotes GLP-1 secretion by delaying glucose absorption and that concomitant inhibition of intestinal SGLT1 and DPP4 is a novel therapeutic option for glycemic control in type 2 diabetes mellitus.


Assuntos
Diabetes Mellitus Experimental/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Mucosa Intestinal/metabolismo , Transportador 1 de Glucose-Sódio/antagonistas & inibidores , Transportador 1 de Glucose-Sódio/metabolismo , Animais , Células CHO , Cricetulus , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Dipeptidil Peptidase 4/metabolismo , Glucose/metabolismo , Humanos , Hiperglicemia/sangue , Hiperglicemia/tratamento farmacológico , Hiperglicemia/metabolismo , Hipoglicemiantes/farmacologia , Absorção Intestinal/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Sprague-Dawley , Ratos Zucker , Transportador 2 de Glucose-Sódio/metabolismo
17.
Chembiochem ; 16(15): 2237-43, 2015 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-26300120

RESUMO

Streptomyces rochei 7434AN4 predominantly produces lankacidin and lankamycin under normal culture conditions, thus suggesting that other biosynthetic gene clusters for secondary metabolites are silent. To identify the silent metabolites of 7434AN4, we constructed mutant KA57 with multiple disruptions of the transcriptional repressor srrB and the biosynthesis genes for both antibiotics. KA57 accumulated a compound (KA57A) with a strong UV absorption at 235 nm, not detected in the parent strain or other mutants. Various spectroscopic analyses revealed that KA57A is an azoxyalkene compound with the molecular formula C10 H20 N2 O3 and with the R configuration at C-2. Biosynthesis of KA57A was also studied by feeding with labeled acetates, amino acids, and 1-hexylamine. The hexenyl moiety (C1'-C6') was derived from fatty acid, whereas the 3-aminobutan-1,2-diol moiety (C1-C4) was derived from C-2 of acetate (C1) and serine (C2-C4). Incorporation of [1,1-(2) H2 ]-1-hexylamine indicated that C1'-C2' dehydrogenation occurs as the final step of biosynthesis.


Assuntos
Alcenos/isolamento & purificação , Alcenos/metabolismo , Antibacterianos/biossíntese , Antibacterianos/isolamento & purificação , Mutação , Streptomyces/genética , Streptomyces/metabolismo , Alcenos/química , Antibacterianos/química , Espectroscopia de Ressonância Magnética , Conformação Molecular
18.
J Pharmacol Sci ; 127(4): 456-61, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25892328

RESUMO

To assess the impact of concomitant inhibition of sodium-glucose cotransporter (SGLT) 2 and dipeptidyl peptidase IV (DPP4) for the treatment of type 2 diabetes mellitus (T2DM), the effect of combined treatment with canagliflozin, a novel SGLT2 inhibitor, and teneligliptin, a DPP4 inhibitor, on glucose intolerance was investigated in Zucker diabetic fatty (ZDF) rats. Canagliflozin potently inhibited human and rat SGLT2 and moderately inhibited human and rat SGLT1 activities but did not affect DPP4 activity. In contrast, teneligliptin inhibited human and rat DPP4 activities but not SGLT activities. A single oral treatment of canagliflozin and teneligliptin suppressed plasma glucose elevation in an oral glucose tolerance test in 13 week-old ZDF rats. This combination of agents elevated plasma active GLP-1 levels in a synergistic manner, probably mediated by intestinal SGLT1 inhibition, and further improved glucose intolerance. In the combination-treated animals, there was no pharmacokinetic interaction of the drugs and no further inhibition of plasma DPP4 activity compared with that in the teneligliptin-treated animals. These results suggest that the inhibition of SGLT2 and DPP4 improves glucose intolerance and that combined treatment with canagliflozin and teneligliptin is a novel therapeutic option for glycemic control in T2DM.


Assuntos
Canagliflozina/farmacologia , Canagliflozina/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Intolerância à Glucose/tratamento farmacológico , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Tiazolidinas/farmacologia , Tiazolidinas/uso terapêutico , Administração Oral , Animais , Canagliflozina/administração & dosagem , Células Cultivadas , Cricetinae , Cricetulus , Diabetes Mellitus Tipo 2/sangue , Dipeptidil Peptidase 4/metabolismo , Inibidores da Dipeptidil Peptidase IV/administração & dosagem , Inibidores da Dipeptidil Peptidase IV/farmacologia , Quimioterapia Combinada , Peptídeo 1 Semelhante ao Glucagon/sangue , Humanos , Hipoglicemiantes/administração & dosagem , Masculino , Pirazóis/administração & dosagem , Ratos Zucker , Transportador 1 de Glucose-Sódio/antagonistas & inibidores , Transportador 2 de Glucose-Sódio , Inibidores do Transportador 2 de Sódio-Glicose , Tiazolidinas/administração & dosagem
19.
Neuropathology ; 35(4): 343-7, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25955768

RESUMO

Neurogenic pulmonary edema (NPE) is a clinical syndrome characterized by the acute onset of pulmonary edema following a significant central nervous system insult. Only a few cases of NPE after Cryptococcal meningitis have been reported. We report a case of NPE following Cryptococcal meningoencephalitis. A 40-year-old man with no medical history was hospitalized for disturbance of consciousness. Blood glucose level was 124 mg/dL. Non-contrast head computed tomography showed no abnormalities. Lumbar puncture revealed a pressure of over 300 mm H2 O and cerebrospinal fluid (CSF) confirmed a white blood cell count of 65/mm(3) . The CSF glucose level was 0 mg/dL. The patient was empirically started on treatment for presumptive bacterial and viral meningitis. Four days after, the patient died in a sudden severe pulmonary edema. Autopsy was performed. We found at autopsy a brain edema with small hemorrhage of the right basal ganglia, severe pulmonary edema and mild cardiomegaly. Histologically, dilated Virchow-Robin spaces, crowded with Cryptococci were observed. In the right basal ganglia, Virchow-Robin spaces were destroyed with hemorrhage and Cryptococci spread to parenchyma of the brain. No inflammatory reaction of the lung was seen. Finally, acute pulmonary edema in this case was diagnosed as NPE following Cryptococcal meningoencephalitis. After autopsy, we found that he was positive for serum antibodies to human immunodeficiency virus.


Assuntos
Infecções por HIV/complicações , Meningite Criptocócica/patologia , Meningoencefalite/patologia , Edema Pulmonar/patologia , Adulto , Anticorpos , Cryptococcus neoformans/isolamento & purificação , Evolução Fatal , Infecções por HIV/sangue , Infecções por HIV/imunologia , Humanos , Masculino , Meningoencefalite/microbiologia , Edema Pulmonar/microbiologia
20.
J Pharmacol Exp Ther ; 351(2): 423-31, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25216746

RESUMO

Sodium-glucose cotransporter 2 (SGLT2) plays a major role in renal glucose reabsorption. To analyze the potential of insulin-independent blood glucose control, the effects of the novel SGLT2 inhibitor canagliflozin on renal glucose reabsorption and the progression of hyperglycemia were analyzed in Zucker diabetic fatty (ZDF) rats. The transporter activity of recombinant human and rat SGLT2 was inhibited by canagliflozin, with 150- to 12,000-fold selectivity over other glucose transporters. Moreover, in vivo treatment with canagliflozin induced glucosuria in mice, rats, and dogs in a dose-dependent manner. It inhibited apparent glucose reabsorption by 55% in normoglycemic rats and by 94% in hyperglycemic rats. The inhibition of glucose reabsorption markedly reduced hyperglycemia in ZDF rats but did not induce hypoglycemia in normoglycemic animals. The change in urinary glucose excretion should not be used as a marker to predict the glycemic effects of this SGLT2 inhibitor. In ZDF rats, plasma glucose and HbA1c levels progressively increased with age, and pancreatic ß-cell failure developed at 13 weeks of age. Treatment with canagliflozin for 8 weeks from the prediabetic stage suppressed the progression of hyperglycemia, prevented the decrease in plasma insulin levels, increased pancreatic insulin contents, and minimized the deterioration of islet structure. These results indicate that selective inhibition of SGLT2 with canagliflozin controls the progression of hyperglycemia by inhibiting renal glucose reabsorption in ZDF rats. In addition, the preservation of ß-cell function suggests that canagliflozin treatment reduces glucose toxicity via an insulin-independent mechanism.


Assuntos
Glucose/metabolismo , Glucosídeos/farmacologia , Hiperglicemia/tratamento farmacológico , Hiperglicemia/patologia , Rim/efeitos dos fármacos , Tiofenos/farmacologia , Animais , Glicemia/efeitos dos fármacos , Canagliflozina , Diabetes Mellitus Experimental , Cães , Hemoglobinas Glicadas/metabolismo , Humanos , Hiperglicemia/metabolismo , Hipoglicemiantes/farmacologia , Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Rim/metabolismo , Rim/patologia , Camundongos , Ratos , Ratos Zucker , Transportador 2 de Glucose-Sódio/metabolismo
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