RESUMEN
Tardigrades are captivating organisms known for their resilience in extreme environments, including ultra-high-dose radiation, but the underlying mechanisms of this resilience remain largely unknown. Using genome, transcriptome, and proteome analysis of Hypsibius henanensis sp. nov., we explored the molecular basis contributing to radiotolerance in this organism. A putatively horizontally transferred gene, DOPA dioxygenase 1 (DODA1), responds to radiation and confers radiotolerance by synthesizing betalains-a type of plant pigment with free radical-scavenging properties. A tardigrade-specific radiation-induced disordered protein, TRID1, facilitates DNA damage repair through a mechanism involving phase separation. Two mitochondrial respiratory chain complex assembly proteins, BCS1 and NDUFB8, accumulate to accelerate nicotinamide adenine dinucleotide (NAD+) regeneration for poly(adenosine diphosphate-ribosyl)ation (PARylation) and subsequent poly(adenosine diphosphate-ribose) polymerase 1 (PARP1)-mediated DNA damage repair. These three observations expand our understanding of mechanisms of tardigrade radiotolerance.
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Reparación del ADN , Tolerancia a Radiación , Tardigrada , Transcriptoma , Animales , Daño del ADN , Transferencia de Gen Horizontal , Genoma , Proteínas Mitocondriales/metabolismo , Proteínas Mitocondriales/genética , Multiómica , NAD/metabolismo , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Poli(ADP-Ribosa) Polimerasa-1/genética , Proteoma , Tolerancia a Radiación/genética , Tardigrada/genética , Tardigrada/metabolismo , Tardigrada/efectos de la radiaciónRESUMEN
RATIONALE: The phenylalkylamine hallucinogen (-)-2,5-dimethoxy-4-methylamphetamine (DOM) exhibits an inverted U-shaped dose-response curve for both head twitch response (HTR) and locomotor activity in mice. Accumulated studies suggest that HTR and locomotor hyperactivity induced by DOM are mainly caused by the activation of serotonin 5-hydroxytryptamine 2 A receptor (5-HT2A receptor). However, the mechanisms underlying the biphasic dose response of HTR and locomotor activity induced by DOM, particularly at high doses, remain unclear. OBJECTIVES: The primary objective of this study is to investigate the modulation of 5-HT2A/2C/1A receptors in HTR and locomotor activity, while also exploring the potential receptor mechanisms underlying the biphasic dose response of DOM. METHODS: In this study, we employed pharmacological methods to identify the specific 5-HT receptor subtypes responsible for mediating the biphasic dose-response effects of DOM on HTR and locomotor activity in C57BL/6J mice. RESULTS: The 5-HT2A receptor selective antagonist (R)-[2,3-di(methoxy)phenyl]-[1-[2-(4-fluorophenyl)ethyl]piperidin-4-yl]methanol (M100907) (500 µg/kg, i.p.) fully blocked the HTR at every dose of DOM (0.615-10 mg/kg, i.p.) in C57BL/6J mice. M100907 (50 µg/kg, i.p.) decreased the locomotor hyperactivity induced by a low dose of DOM (0.625, 1.25 mg/kg, i.p.), but had no effect on the locomotor hypoactivity induced by a high dose of DOM (10 mg/kg) in C57BL/6J mice. The 5-HT2C antagonist 6-chloro-5-methyl-1-[(2-[2-methylpyrid-3yloxy]pyrid-5yl)carbamoyl]indoline (SB242084) (0.3, 1 mg/kg, i.p.) reduced the HTR induced by a dose of 2.5 mg/kg DOM, but did not affect the response to other doses. SB242084 (1 mg/kg, i.p.) significantly increased the locomotor activity induced by DOM (0.615-10 mg/kg, i.p.) in mice. The 5-HT1A antagonist N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]N-(2-pyridinyl) cyclohexane carboxamide maleate (WAY100635) (1 mg/kg, i.p.) increased both HTR and locomotor activity induced by DOM in mice. The 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) (1 mg/kg, i.p.) significantly reduced both the HTR and locomotor activity induced by DOM in mice. Additionally, pretreatment with the Gαi/o inhibitor PTX (0.25 µg/mouse, i.c.v.) enhanced the HTR induced by DOM and attenuated the effect of DOM on locomotor activity in mice. CONCLUSIONS: Receptor subtypes 5-HT2C and 5-HT1A are implicated in the inverted U-shaped dose-response curves of HTR and locomotor activity induced by DOM in mice. The biphasic dose-response function of HTR and locomotor activity induced by DOM has different mechanisms in mice.
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Relación Dosis-Respuesta a Droga , Receptor de Serotonina 5-HT2C , Animales , Ratones , Masculino , Receptor de Serotonina 5-HT2C/efectos de los fármacos , Receptor de Serotonina 5-HT2C/metabolismo , 2,5-Dimetoxi-4-Metilanfetamina/farmacología , Piperidinas/farmacología , Piperidinas/administración & dosificación , Receptor de Serotonina 5-HT2A/efectos de los fármacos , Receptor de Serotonina 5-HT2A/metabolismo , Locomoción/efectos de los fármacos , Locomoción/fisiología , Actividad Motora/efectos de los fármacos , Actividad Motora/fisiología , Receptor de Serotonina 5-HT1A/efectos de los fármacos , Receptor de Serotonina 5-HT1A/metabolismo , Alucinógenos/farmacología , Alucinógenos/administración & dosificación , Ratones Endogámicos C57BL , Movimientos de la Cabeza/efectos de los fármacos , Aminopiridinas/farmacología , Aminopiridinas/administración & dosificación , Antagonistas del Receptor de Serotonina 5-HT2/farmacología , Antagonistas del Receptor de Serotonina 5-HT2/administración & dosificación , Fluorobencenos/farmacología , Agonistas del Receptor de Serotonina 5-HT2/farmacología , Agonistas del Receptor de Serotonina 5-HT2/administración & dosificación , IndolesRESUMEN
Certain amino acid sites of 5-HT2AR play crucial roles in interacting with various G proteins. Hallucinogens and non-hallucinogens both act on 5-HT2AR but mediate different pharmacological effects, possibly due to the coupling of different G proteins. Therefore, this study identified the binding sites of hallucinogens and non-hallucinogens with 5-HT2AR through molecular docking. We conducted site mutation to examine the impact of these sites on G proteins, in order to find out the sites that can distinguish the pharmacological effects of hallucinogens and non-hallucinogens. Our results indicate that I4.60A and S3.39A did not affect the ability of hallucinogens to activate Gq signaling, but significantly reduced Gs signaling activation by hallucinogens. These results suggest that S3.39 and I4.60 are important for the activation of Gs signaling by hallucinogens.
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Receptor de Serotonina 5-HT2A , Serina , Transducción de Señal , Receptor de Serotonina 5-HT2A/metabolismo , Receptor de Serotonina 5-HT2A/genética , Receptor de Serotonina 5-HT2A/química , Humanos , Células HEK293 , Serina/metabolismo , Serina/química , Sitios de Unión , Isoleucina/metabolismo , Isoleucina/química , Simulación del Acoplamiento Molecular , Alucinógenos/farmacología , Alucinógenos/metabolismo , Alucinógenos/química , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/química , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/genética , Unión ProteicaRESUMEN
BACKGROUND: Psilocybin offers new hope for treating mood disorders due to its rapid and sustained antidepressant effects, as standard medications require weeks or months to exert their effects. However, the mechanisms underlying this action of psilocybin have not been identified. AIMS: To investigate whether psilocybin has rapid and sustained antidepressant-like effects in mice and investigate whether its potential mechanisms of action are related to promoted neuroplasticity. METHODS: We first examined the antidepressant-like effects of psilocybin in normal mice by the forced swimming test and in chronic corticosterone (CORT)-exposed mice by the sucrose preference test and novelty-suppressed feeding test. Furthermore, to explore the role of neuroplasticity in mediating the antidepressant-like effects of psilocybin, we measured structural neuroplasticity and neuroplasticity-associated protein levels in the prefrontal cortex (PFC) and hippocampus. RESULTS: We observed that a single dose of psilocybin had rapid and sustained antidepressant-like effects in both healthy mice and chronic CORT-exposed mice. Moreover, psilocybin ameliorated chronic CORT exposure-induced inhibition of neuroplasticity in the PFC and hippocampus, including by increasing neuroplasticity (total number of dendritic branches and dendritic spine density), synaptic protein (p-GluA1, PSD95 and synapsin-1) levels, BDNF-mTOR signalling pathway activation (BDNF, TrkB and mTOR levels), and promoting neurogenesis (number of DCX-positive cells). CONCLUSIONS: Our results demonstrate that psilocybin elicits robust, rapid and sustained antidepressant-like effects which is accompanied by the promotion of neuroplasticity in the PFC and hippocampus.
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Antidepresivos , Factor Neurotrófico Derivado del Encéfalo , Corticosterona , Hipocampo , Plasticidad Neuronal , Corteza Prefrontal , Psilocibina , Animales , Plasticidad Neuronal/efectos de los fármacos , Antidepresivos/farmacología , Ratones , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/metabolismo , Masculino , Psilocibina/farmacología , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Depresión/tratamiento farmacológico , Ratones Endogámicos C57BL , Serina-Treonina Quinasas TOR/metabolismo , Proteína Doblecortina , Conducta Animal/efectos de los fármacos , Modelos Animales de EnfermedadRESUMEN
TSPO, translocator protein (18 kDa) ligands have demonstrated consistent antidepression and anxiolytic effects in several preclinical studies. This study aimed to examine whether YL-IPA08[N-ethyl-N-(2-pyridinylmethyl)-2-(3,4-ichlorophenyl) -7-methylimidazo [1,2-a] pyridine-3-acetamide hydrochloride], a potent and selective TSPO ligand synthesized by our institute, could alleviate anxiety-related behaviors induced by electric shock (ES) and investigate its underlying mechanism. As expected, we showed that chronic treatment with YL-IPA08 significantly reversed anxiety-related behaviors induced by electrical stimulation (0.5 mA, 12 times, duration 1s, interval 10s) exposure. Using the analysis of RNA-sequencing (RNA-seq) technology, it was found that the differential genes associated with the anxiolytic effect of YL-IPA08 were mainly related to synaptic plasticity. Furthermore, YL-IPA08 restored the decreased levels of brain-derived neurotrophic factor (BDNF), synapse-related protein (e.g. synapsin-1 and post-synaptic density95, PSD95), and the number of doublecortin (DCX) + neurons in the hippocampus of post-ES mice. In addition, YL-IPA08 also enhanced the dendritic complexity and dendritic spine density of hippocampal dentate gyrus (DG) granule neurons. Meanwhile, the induction of long-term potentiation (LTP) was significantly enhanced by YL-IPA08. In summary, the findings from the current study showed that YL-IPA08 exerted a clear anxiolytic effect, which might be partially mediated by promoting hippocampal neuroplasticity.
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Ansiolíticos , Imidazoles , Ratones , Animales , Ansiolíticos/farmacología , Ansiolíticos/uso terapéutico , Ligandos , Hipocampo , Piridinas/farmacología , Plasticidad NeuronalRESUMEN
BACKGROUND: Posttraumatic stress disorder (PTSD) and depression are highly comorbid. Psilocybin exerts substantial therapeutic effects on depression by promoting neuroplasticity. Fear extinction is a key process in the mechanism of first-line exposure-based therapies for PTSD. We hypothesized that psilocybin would facilitate fear extinction by promoting hippocampal neuroplasticity. METHODS: First, we assessed the effects of psilocybin on percentage of freezing time in an auditory cued fear conditioning (FC) and fear extinction paradigm in mice. Psilocybin was administered 30 min before extinction training. Fear extinction testing was performed on the first day; fear extinction retrieval and fear renewal were tested on the sixth and seventh days, respectively. Furthermore, we verified the effect of psilocybin on hippocampal neuroplasticity using Golgi staining for the dendritic complexity and spine density, Western blotting for the protein levels of brain derived neurotrophic factor (BDNF) and mechanistic target of rapamycin (mTOR), and immunofluorescence staining for the numbers of doublecortin (DCX)- and bromodeoxyuridine (BrdU)-positive cells. RESULTS: A single dose of psilocybin (2.5 mg/kg, i.p.) reduced the increase in the percentage of freezing time induced by FC at 24 h, 6th day and 7th day after administration. In terms of structural neuroplasticity, psilocybin rescued the decrease in hippocampal dendritic complexity and spine density induced by FC; in terms of neuroplasticity related proteins, psilocybin rescued the decrease in the protein levels of hippocampal BDNF and mTOR induced by FC; in terms of neurogenesis, psilocybin rescued the decrease in the numbers of DCX- and BrdU-positive cells in the hippocampal dentate gyrus induced by FC. CONCLUSIONS: A single dose of psilocybin facilitated rapid and sustained fear extinction; this effect might be partially mediated by the promotion of hippocampal neuroplasticity. This study indicates that psilocybin may be a useful adjunct to exposure-based therapies for PTSD and other mental disorders characterized by failure of fear extinction.
Asunto(s)
Miedo , Psilocibina , Humanos , Ratones , Animales , Psilocibina/farmacología , Psilocibina/uso terapéutico , Psilocibina/metabolismo , Extinción Psicológica , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Bromodesoxiuridina/metabolismo , Bromodesoxiuridina/farmacología , Hipocampo/metabolismo , Plasticidad Neuronal , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Psychedelics alter consciousness and may have potential for drug development. As psychedelics are likely therapeutically active, it is important to study their effects and mechanisms using preclinical models. Here, we examined the effects of phenylalkylamine and indoleamine psychedelics on locomotor activity and exploratory behaviour using the mouse Behavioural Pattern Monitor (BPM). DOM, mescaline, and psilocin reduced locomotor activity at high doses and influenced rearings, an exploratory behaviour, in a characteristic inverted U-shaped dose-response function. Pretreatment with the selective 5-HT2A antagonist M100907 reversed the drug-induced alterations in locomotor activity, rearings, and jumps after systemic administration of DOM at low doses. However, holepoking at the full range of doses tested was not blocked by M100907. Administration of the hallucinogenic 5-HT2A agonist 25CN-NBOH induced striking similarities in response to that to psychedelics; these alterations were significantly diminished by M100907, whereas the putatively non-hallucinogenic 5-HT2A agonist TBG did not affect locomotor activity, rearings, or jumps at the most effective doses. The nonhallucinogenic 5-HT2A agonist lisuride failed to increase rearing. The results of these experiments provide strong evidence that DOM-elicited increases in rearing are due to mediation by the 5-HT2A receptor. Finally, discriminant analysis was able to distinguish all four psychedelics from lisuride and TBG based on behavioural performance alone. Thus, increased rearing in mice could provide additional evidence of behavioural differences between hallucinogenic and nonhallucinogenic 5-HT2A agonists.
RESUMEN
Chemodynamic therapy (CDT) is novel and promising for cancer treatment, however, the potential systematic toxicity of the used nanoparticles is still a big concern. In this work the biocompatible hypocrellin A-Fe(III) nanoparticles (HA-Fe(III) NPs) were synthesized and studied. The CDT effect of HA-Fe(III) NPs in the dark is negligible but can be photo-activated upon red light irradiation, which is meaningful to realize precise CDT treatment by selective light irradiation. Moreover, HA-Fe(III) NPs can also generate O2Ë-, which may be converted into H2O2 to further enhance the CDT effect. As a result, HA-Fe(III) NPs had little cytotoxicity in the dark at the concentration up to 200 µg ml-1, but exhibited efficient CDT activity upon red light irradiation under both normoxic and hypoxic conditions. The in vivo results also showed that HA-Fe(III) NPs can efficiently inhibit tumor growth upon 628 nm light irradiation.
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Antineoplásicos/química , Antineoplásicos/farmacología , Hierro/química , Nanopartículas del Metal/química , Perileno/análogos & derivados , Fenol/química , Quinonas/química , Nanomedicina Teranóstica , Línea Celular Tumoral , Resistencia a Antineoplásicos , Humanos , Perileno/química , Procesos FotoquímicosRESUMEN
Novel antibacterial agents capable of efficiently sterilizing intracellular Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) but with low cytotoxicity and low resistance development are quite appealing. In this work, three Ru(II) complexes with photolabile ligands were explored to realize such a goal. Complex 3 (5 µM) can inhibit more than 90% growth of S. aureus/MRSA that has invaded in J774A.1 cells upon visible light irradiation, being much more efficient than vancomycin. In similar conditions, negligible dark- and phototoxicity were found toward the host cells. The bactericidal activity is highly correlated with DNA covalent binding by the Ru(II) fractions generated after ligand photodissociation. Moreover, S. aureus quickly developed resistance toward vancomycin, while negligible resistance toward complex 3 even after 700 generations was obtained. These appealing results may pave a new way for fighting against intracellular antibiotic-resistant pathogens.
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Antibacterianos/farmacología , Complejos de Coordinación/química , Luz , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Rutenio/química , Staphylococcus aureus/efectos de los fármacos , Animales , Antibacterianos/química , Antibacterianos/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Complejos de Coordinación/metabolismo , Complejos de Coordinación/farmacología , ADN/química , ADN/metabolismo , Eritrocitos/citología , Eritrocitos/efectos de los fármacos , Eritrocitos/metabolismo , Hemólisis/efectos de los fármacos , Humanos , Ligandos , Fotólisis , ConejosRESUMEN
Ru(ii)-based photoactivated chemotherapy (PACT) agents are promising; however, their short wavelength absorption (generally <550 nm) and poor tumor accumulation ability limit their in vivo applications. Herein, bovine serum albumin (BSA) coated lanthanide-doped upconversion nanoparticles (NaYF4:Yb:Tm@NaYF4 (UCNPs)) were loaded with a Ru(ii) PACT agent, i.e. [Ru(dip)2(spc)]+ (dip = 4,7-diphenyl-1,10-phenanthroline; spc = 2-sulfonic acid pyridine-3-carboxylic acid). The resultant UCNP@BSA@Ru can transfer [Ru(dip)2(spc)]+ to tumor cells in vitro as well as tumor tissues in vivo highly efficiently and selectively owing to the targeting ability of BSA and the enhanced permeability and retention effect of the nanoparticles. The subsequent near infrared (NIR) light irradiation at 980 nm or visible light irradiation at 470 nm can initiate dissociation of the spc ligand, and the released Ru(ii) aqua compounds ([Ru(dip)2(H2O)2]2+) may exert a potent cytotoxicity towards a series of cancer cells but a much weaker effect on the normal IOSE80 cells. The in vivo (mouse) results showed that UCNP@BSA@Ru could inhibit tumor growth upon 980 nm irradiation more efficiently than in the dark and more efficiently than cisplatin (in the dark).
RESUMEN
Ru(ii) polypyridyl complexes which can undergo photo-induced ligand dissociation and DNA covalent binding are considered as potential photoactivated chemotherapeutic (PACT) agents. Herein four pyridine-2-sulfonate (py-SO3-) ligand based Ru(ii) complexes [Ru(N-N)2(py-SO3)]+ (1-4) were synthesized and studied. All the complexes can undergo fast py-SO3- ligand dissociation and DNA covalent binding upon visible light irradiation. However, only complex 4 exhibited high photo-induced anticancer activities towards a series of cancer cells, with half maximal inhibitory concentration (IC50) values in 100-300 nM regions and phototoxicity index (PI) values of about 100. In particular, complex 4 can also kill cisplatin resistant SKOV-3 and A549 cancer cells with IC50 values in 200-400 nM regions and PI values of about 50, which should be the first report of Ru(ii) based PACT agents that are also effective towards cisplatin resistant cancer cells. Complex 4 exhibited much higher cell uptake and nuclear accumulation levels, which may be the main reasons for its high anticancer activities. The in vivo anticancer experiments indicated that complex 4 can inhibit tumor growth significantly with fewer side effects. Our results may provide guidelines for developing novel photoactivatable Ru(ii) anticancer agents.
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Antineoplásicos/farmacología , Complejos de Coordinación/farmacología , Luz , Fármacos Fotosensibilizantes/farmacología , Rutenio/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Estructura Molecular , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/patología , Fármacos Fotosensibilizantes/síntesis química , Fármacos Fotosensibilizantes/química , Rutenio/química , Relación Estructura-ActividadRESUMEN
Novel fatty acid-bile acid conjugates (1a-1k) were designed and synthesized by coupling of the fatty acids to the 3-OH of bile acids using lysine for linkage. In the conjugates, the 24-COOH of the bile acids was kept intact to preserve liver-specific recognition. The ability of the newly synthesized conjugates (at 100 mg/kg dosage) to reduce total cholesterol (TC) and triglyceride (TG) levels in mice fed with high-fat diet (HFD) was evaluated. Conjugates of stearic acid with cholic acid and palmitic acid with ursodeoxycholic acid (at dosages of 50, 100, and 200 mg/kg) were further evaluated to determine their ability to reduce aspartate aminotransferase (AST), alanine aminotransferase (ALT), TC, and TG levels in mice fed with HFD. All conjugates showed potent hypolipidemic activity. Further investigation revealed that compounds 1c and 1 g not only dose-dependently reduced serum levels of TC and TG, but also inhibited the elevation of serum AST and ALT levels in mice fed with HFD. Thus, compounds 1c and 1 g are promising hypolipidemic agents with hepatocyte protective effects against HFD-induced liver damage.
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Ácidos y Sales Biliares/administración & dosificación , Ácidos Grasos/administración & dosificación , Hiperlipidemias/tratamiento farmacológico , Hipolipemiantes/administración & dosificación , Hígado/efectos de los fármacos , Animales , Ácidos y Sales Biliares/química , Colesterol/sangre , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Ácidos Grasos/química , Humanos , Hiperlipidemias/sangre , Hiperlipidemias/etiología , Hiperlipidemias/patología , Hipolipemiantes/química , Metabolismo de los Lípidos/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Pruebas de Función Hepática , Lisina/química , Ratones , Triglicéridos/sangreRESUMEN
The first example of the synthesis of mono-N,O-B-chelated dipyrromethene (BODIPY) derivatives through an unexpected intramolecular nucleophilic displacement of the fluorine by alkenols in the presence of boron trifluoride as Lewis acid is reported. The chlorine in the indacene core allowed for further structural modifications through nucleophilic substitutions or palladium-catalysed coupling reactions to afford new fluorophores with tuneable photophysical properties. Their expanded conjugation structure resulted in distinct red-shifted absorption and emission spectra in organic solutions. Furthermore, the twisted steric hindrance of the benzene substitution patterns suppressed aggregation-induced quenching, leading to an enhanced NIR emission in the aggregate/solid state, which was rarely observed for BODIPY dyes. Nanoparticles of the fluorophores formed by the assembly with the polymeric surfactant F127 were successfully used for bioimaging of living cells and for tumour-targeted imaging in a tumour-bearing mouse model.
RESUMEN
In an attempt to improve the antitumor activity and reduce the side effects of irinotecan (2), novel prodrugs of SN-38 (3) were prepared by conjugating amino acids or dipeptides to the 10-hydroxyl group of SN-38 via a carbamate linkage. The synthesized compounds completely generated SN-38 in pH 7.4 buffer or in human plasma, while remaining stable under acidic conditions. All prodrug compounds demonstrated much greater in vitro antitumor activities against HeLa cells and SGC-7901 cells than irinotecan. The most active compounds, 5h, 7c, 7d, and 7f, exhibited IC50 values that were 1000 times lower against HeLa cells and 30 times lower against SGC-7901 cells than those of irinotecan, and the inhibitory activities of these prodrugs against acetylcholinesterase (AchE) were significantly reduced, with IC50 values more than 6.8 times greater than that of irinotecan. In addition, compound 5e exhibited the same level of tumor growth inhibitory activity as irinotecan (CPT-11) in a human colon xenograft model in vivo.
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Camptotecina/análogos & derivados , Profármacos/síntesis química , Profármacos/farmacología , Animales , Camptotecina/síntesis química , Camptotecina/química , Camptotecina/farmacología , Camptotecina/uso terapéutico , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Inhibidores de la Colinesterasa/farmacología , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/patología , Estabilidad de Medicamentos , Humanos , Concentración de Iones de Hidrógeno , Irinotecán , Ratones Desnudos , Profármacos/química , Profármacos/uso terapéutico , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The reaction of U-shaped, bimetallic, Cu(I) complexes, assembled from a heteroditopic pincer, with cyano-capped pi-conjugated linkers gives a straightforward access to pi-stacked metallocyclophanes in good yields. In these assemblies, the pi-walls have an almost face-to-face arrangement. The versatility of this rational supramolecular synthesis is demonstrated with the use of linkers that have nanoscale lengths (up to 27.7 A), different chemical compositions (oligo(para-phenylenevinylene)s OPVs, oligo(phenylene)s, oligo(phenylethynylene)s), and alternative geometries (linear, angular). Linkers that incorporate an internal pyridyne moiety can also be employed. X-ray diffraction studies revealed that the metallocyclophanes based on linear linkers self-organize into infinite pi-stacked columns in the solid state with intermolecular distances of about 3.6 A. This approach, based on coordination-driven self-assembly, provides a novel and rational strategy for the stacking of extended pi-systems in the solid state.