Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 230
Filtrar
1.
J Am Chem Soc ; 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-39446027

RESUMO

Spiro-OMeTAD hole transport materials typically exhibit an amorphous state in perovskite solar cells. However, the lack of structural ordering leads to weak intermolecular interaction, inferior carrier transfer, and poor stability in devices. Herein, we developed a π-conjugation-induced short-range ordering strategy to modulate the stacking order of spiro-OMeTAD during film formation. A clear molecular ordering at the nanoscale is observed, which enhances intermolecular π-π stacking in spiro-OMeTAD and enables effective carrier extraction and favorable energy level alignment. The nanoscale-ordered spiro-OMeTAD allows the achievement of perovskite solar cells with a champion efficiency of 25.37%, surpassing devices utilizing amorphous spiro-OMeTAD (23.52%). The unencapsulated device demonstrates enhanced operational stability by retaining 98% of its initial efficiency under continuous 1 sun equivalent illumination at 60 °C for 840 h. This work establishes a significant and valid modulation concept for the stacking order of organic transport materials, paving the way for the development of efficient and stable perovskite solar cells.

2.
Am J Physiol Heart Circ Physiol ; 326(1): H166-H179, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37947434

RESUMO

Neurons in the stellate ganglion (SG) provide sympathetic innervation to the heart, brown adipose tissue (BAT), and other organs. Sympathetic innervation to the heart becomes hyperactive following myocardial infarction (MI). The impact of MI on the morphology of cardiac sympathetic neurons is not known, but we hypothesized that MI would stimulate increased cell and dendritic tree size in cardiac neurons. In this study, we examined the effects of ischemia-reperfusion MI on sympathetic neurons using dual retrograde tracing methods to allow detailed characterization of cardiac- and BAT-projecting neurons. Different fluorescently conjugated cholera toxin subunit B (CTb) tracers were injected into the pericardium and the interscapular BAT pads, respectively. Experimental animals received a 45-min occlusion of the left anterior descending coronary artery and controls received sham surgery. One week later, hearts were collected for assessment of MI infarct and SGs were collected for morphological or electrophysiological analysis. Cardiac-projecting SG neurons from MI mice had smaller cell bodies and shorter dendritic trees compared with sham animals, specifically on the left side ipsilateral to the MI. BAT-projecting neurons were not altered by MI, demonstrating the subpopulation specificity of the response. The normal size and distribution differences between BAT- and cardiac-projecting stellate ganglion neurons were not altered by MI. Patch-clamp recordings from cardiac-projecting left SG neurons revealed increased spontaneous excitatory postsynaptic currents despite the decrease in cell and dendritic tree size. Thus, increased dendritic tree size does not contribute to the enhanced sympathetic neural activity seen after MI.NEW & NOTEWORTHY Myocardial infarction (MI) causes structural and functional changes specifically in stellate ganglion neurons that project to the heart, but not in cells that project to brown adipose fat tissue.


Assuntos
Infarto do Miocárdio , Gânglio Estrelado , Animais , Camundongos , Gânglio Estrelado/fisiologia , Coração/inervação , Neurônios/fisiologia , Reperfusão
3.
J Med Virol ; 96(1): e29357, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38235532

RESUMO

The Coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a global threat, exacerbated by the emergence of viral variants. Two variants of SARS-CoV-2, Omicron BA.2.75 and BA.5, led to global infection peaks between May 2022 and May 2023, yet their precise characteristics in pathogenesis are not well understood. In this study, we compared these two Omicron sublineages with the previously dominant Delta variant using a human angiotensin-converting enzyme 2 knock-in mouse model. As expected, Delta exhibited higher viral replication in the lung and brain than both Omicron sublineages which induced less severe lung damage and immune activation. In contrast, the Omicron variants especially BA.5.2 showed a propensity for cellular proliferation and developmental pathways. Both Delta and BA.5.2 variants, but not BA.2.75, led to decreased pulmonary lymphocytes, indicating differential adaptive immune response. Neuroinvasiveness was shared with all strains, accompanied by vascular abnormalities, synaptic injury, and loss of astrocytes. However, Immunostaining assays and transcriptomic analysis showed that BA.5.2 displayed stronger immune suppression and neurodegeneration, while BA.2.75 exhibited more similar characteristics to Delta in the cortex. Such differentially infectious features could be partially attributed to the weakened interaction between Omicron Spike protein and host proteomes decoded via co-immunoprecipitation followed by mass spectrometry in neuronal cells. Our present study supports attenuated replication and pathogenicity of Omicron variants but also highlights their newly infectious characteristics in the lung and brain, especially with BA.5.2 demonstrating enhanced immune evasion and neural damage that could exacerbate neurological sequelae.


Assuntos
COVID-19 , Doenças Transmissíveis , Doenças do Sistema Nervoso , Animais , Camundongos , Humanos , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética
4.
Proc Natl Acad Sci U S A ; 118(16)2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33846240

RESUMO

Positive allosteric modulators (PAMs) of the mu-opioid receptor (MOR) have been hypothesized as potentially safer analgesics than traditional opioid drugs. This is based on the idea that PAMs will promote the action of endogenous opioid peptides while preserving their temporal and spatial release patterns and so have an improved therapeutic index. However, this hypothesis has never been tested. Here, we show that a mu-PAM, BMS-986122, enhances the ability of the endogenous opioid Methionine-enkephalin (Met-Enk) to stimulate G protein activity in mouse brain homogenates without activity on its own and to enhance G protein activation to a greater extent than ß-arrestin recruitment in Chinese hamster ovary (CHO) cells expressing human mu-opioid receptors. Moreover, BMS-986122 increases the potency of Met-Enk to inhibit GABA release in the periaqueductal gray, an important site for antinociception. We describe in vivo experiments demonstrating that the mu-PAM produces antinociception in mouse models of acute noxious heat pain as well as inflammatory pain. These effects are blocked by MOR antagonists and are consistent with the hypothesis that in vivo mu-PAMs enhance the activity of endogenous opioid peptides. Because BMS-986122 does not bind to the orthosteric site and has no inherent agonist action at endogenously expressed levels of MOR, it produces a reduced level of morphine-like side effects of constipation, reward as measured by conditioned place preference, and respiratory depression. These data provide a rationale for the further exploration of the action and safety of mu-PAMs as an innovative approach to pain management.


Assuntos
Regulação Alostérica/fisiologia , Dor/tratamento farmacológico , Receptores Opioides mu/metabolismo , Regulação Alostérica/efeitos dos fármacos , Analgesia/métodos , Analgésicos , Analgésicos Opioides/farmacologia , Animais , Células CHO , Cricetulus , Feminino , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Morfina , Antagonistas de Entorpecentes , Manejo da Dor/métodos , Estudo de Prova de Conceito , Ratos , Ratos Sprague-Dawley , Receptores Opioides mu/efeitos dos fármacos
5.
Phytochem Anal ; 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39072803

RESUMO

INTRODUCTION: The identification of Aucklandiae Radix (AR), Vladimiriae Radix (VR), and Inulae Radix (IR) based on traits and microscopic features is susceptible to the state of samples and the subjective awareness of personnel, and the identification based on a few or single chemical compositions is a cumbersome and time-consuming procedure and fails to rationally and effectively utilize the information of unknown components and is not specificity enough. OBJECTIVES: This study aimed to improve the identification efficiency, strengthen supervision, and realize digital identification of three Chinese medicines. Ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) combined with multivariate algorithms was used to explore the digital identification of AR, VR, and IR. MATERIALS AND METHODS: UHPLC-QTOF-MS was used to analyze AR, VR, and IR. The MS data combined with multivariate algorithms such as partial least squares discrimination analysis (PLS-DA) and artificial neural networks (ANNs) was used to filter important variables and data modeling. Finally, the optimal model was selected for the digital identification of three herbs. RESULTS: The results showed that three herbs can be distinguished on the whole level, and through feature screening, 591 characteristic variables combined with multivariate algorithms to construct data models. The ANN model was the best with accuracy = 0.983, precision = 0.984, and external verification showed the reliability and practicability of ANN model. CONCLUSION: ANN model combined with MS data is of great significance for tdigital identification of AR, VR, and IR. It is an important reference for developing the digital identification of traditional Chinese medicines at the individual level based on UHPLC-QTOF-MS and multivariate algorithms.

6.
Angew Chem Int Ed Engl ; 63(10): e202318591, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38230583

RESUMO

The thermally stable inorganic cesium-based perovskites promise efficient and stable photovoltaics. Unfortunately, the strong ionic bonds lead to uncontrollable rapid crystallization, making it difficult in fabricating large-area black-phase film for photovoltaics. Herein, we developed a facile hydrogen-bonding assisted strategy for modulating the crystallization of CsPbI2 Br to achieve uniform large-area phase-pure films with much-reduced defects. The simple addition of methylamine acetate in precursors not only promotes the formation of intermediate phase via hydrogen bonding to circumvent the direct crystallization of CsPbI2 Br from ionic precursors but also widens the film processing window, thus enabling to fabricate large-area high-quality phase-pure CsPbI2 Br film under benign conditions. Combining with stable dopant-free poly(3-hexylthiophene), the CsPbI2 Br solar cells achieve the record-high efficiencies of 18.14 % and 16.46 % for 0.1 cm2 and 1 cm2 active area, respectively. The obtained high efficiency of 38.24 % under 1000 lux illumination suggests its potential in indoor photovoltaics for powering the Internet of Things, etc.

7.
J Physiol ; 601(7): 1247-1264, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36797985

RESUMO

The sympathetic nervous system vitally regulates autonomic functions, including cardiac activity. Postganglionic neurons of the sympathetic chain ganglia relay signals from the central nervous system to autonomic peripheral targets. Disrupting this flow of information often dysregulates organ function and leads to poor health outcomes. Despite the importance of these sympathetic neurons, fundamental aspects of the neurocircuitry within peripheral ganglia remain poorly understood. Conventionally, simple monosynaptic cholinergic pathways from preganglionic neurons are thought to activate postganglionic sympathetic neurons. However, early studies suggested more complex neurocircuits may be present within sympathetic ganglia. The present study recorded synaptic responses in sympathetic stellate ganglia neurons following electrical activation of the pre- and postganglionic nerve trunks and used genetic strategies to assess the presence of collateral projections between postganglionic neurons of the stellate ganglia. Orthograde activation of the preganglionic nerve trunk, T-2, uncovered high jitter synaptic latencies consistent with polysynaptic connections. Pharmacological inhibition of nicotinic acetylcholine receptors with hexamethonium blocked all synaptic events. To confirm that high jitter, polysynaptic events were due to the presence of cholinergic collaterals from postganglionic neurons within the stellate ganglion, we knocked out choline acetyltransferase in adult noradrenergic neurons. This genetic knockout eliminated orthograde high jitter synaptic events and EPSCs evoked by retrograde activation. These findings suggest that cholinergic collateral projections arise from noradrenergic neurons within sympathetic ganglia. Identifying the contributions of collateral excitation to normal physiology and pathophysiology is an important area of future study and may offer novel therapeutic targets for the treatment of autonomic imbalance. KEY POINTS: Electrical stimulation of a preganglionic nerve trunk evoked fast synaptic transmission in stellate ganglion neurons with low and high jitter latencies. Retrograde stimulation of a postganglionic nerve trunk evoked direct, all-or-none action currents and delayed nicotinic EPSCs indistinguishable from orthogradely-evoked EPSCs in stellate neurons. Nicotinic acetylcholine receptor blockade prevented all spontaneous and evoked synaptic activity. Knockout of acetylcholine production in noradrenergic neurons eliminated all retrogradely-evoked EPSCs but did not change retrograde action currents, indicating that noradrenergic neurons have cholinergic collaterals connecting neurons within the stellate ganglion.


Assuntos
Neurônios Adrenérgicos , Camundongos , Animais , Camundongos Knockout , Sistema Nervoso Simpático/fisiologia , Gânglios Simpáticos/fisiologia , Colinérgicos
8.
J Am Chem Soc ; 145(10): 5872-5879, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36872583

RESUMO

Passivating defects using organic halide salts, especially chlorides, is an effective method to improve power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) arising from the stronger Pb-Cl bonding than Pb-I and Pb-Br bonding. However, Cl- anions with a small radius are prone to incorporation into the perovskite lattice that distorts the lead halide octahedron, degrading the photovoltaic performance. Here, we substitute atomic-Cl-containing organic molecules for widely used ionic-Cl salts, which not only retain the efficient passivation by Cl but also prevent the incorporation of Cl into the bulk lattice, benefiting from the strong covalent bonding between Cl atoms and organic frameworks. We find that only when the distance of Cl atoms in single molecules matches well with the distance of halide ions in perovskites can such a configuration maximize the defect passivation. We thereby optimize the molecular configuration to enable multiple Cl atoms in an optimal spatial position to maximize their binding with surface defects. The resulting PSCs achieve a certified PCE of 25.02%, among the highest PCEs for PSCs, and retain 90% of their initial PCE after 500 h of continuous operation.

9.
Analyst ; 147(18): 4098-4104, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-35946518

RESUMO

In this work, the first endoplasmic reticulum-targeted near-infrared fluorescent probe, ISO-Chy, with a dicyanoisophorone derivative as a fluorophore is reported by introducing the recognition group of 4-bromobutyl for chymotrypsin detection. The probe can be easily synthesized and has shown satisfactory sensitivity and selectivity to chymotrypsin. Meanwhile, ISO-Chy has a large Stokes shift (135 nm) to minimize self-absorption and interference from autofluorescence and then generate significant fluorescence enhancement upon incubation with chymotrypsin. Additionally, ISO-Chy has an excellent ability to target the endoplasmic reticulum, along with preferable Pearson's correlation coefficients (Rr) of 0.9411 and 0.9522 in P815 cells and HepG2 cells, respectively. Moreover, ISO-Chy was successfully utilized to visualize endogenous chymotrypsin in P815 cells and HepG2 cells and was first used to detect chymotrypsin activity in HepG2 tumor-bearing mice. These findings indicate that ISO-Chy could be an effective tool for detecting endogenous chymotrypsin activity, supporting its use for investigating chymotrypsin function in pathologic processes.


Assuntos
Quimotripsina , Corantes Fluorescentes , Animais , Quimotripsina/análise , Retículo Endoplasmático , Células Hep G2 , Humanos , Camundongos , Microscopia de Fluorescência/métodos , Imagem Óptica
10.
J Sep Sci ; 45(7): 1297-1304, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35000282

RESUMO

Pulsatillae Radix, the root of Pulsatilla chinensis (Bge.) Regel, is recorded in the Pharmacopoeia of the People's Republic of China and has been widely used for its pharmacological activities, such as anti-inflammatory, antioxidant, antibacterial, antitumor, and cardiovascular benefits. However, there are several look-alike species that can be marketed as Pulsatillae Radix. To distinguish P. chinensis (Bge.) Regel from its look-alikes, viz. Pulsatilla cernua (Thunb.) Bercht et Opiz., Pulsatilla dahurica (Fisch.) Spreng., Anemone tomeutosa (Maxim.) Pei., and Rhaponticum uniflorum (L.) DC, we used ultra high performance liquid chromatography with time-of-flight mass spectrometry combined with principal component analysis to compare their chemical compositions. Four ions, a (RT 8.98 min, m/z 1381.6671), b (RT 10.64 min, m/z 1219.6143), c (RT 11.52 min, m/z 1217.5978), and d (RT 13.6 min, m/z 749.4463), from P. chinensis (Bge.) Regel were identified as potential chemical markers to distinguish it from look-alike species using an unsupervised statistical model combined with orthogonal partial least-squares discriminant analysis. The results of this study provide an effective method for identifying and distinguishing P. chinensis (Bge.) Regel from similar plants.


Assuntos
Anemone , Pulsatilla , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Espectrometria de Massas , Análise Multivariada , Pulsatilla/química
11.
Zhongguo Zhong Yao Za Zhi ; 47(3): 635-642, 2022 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-35178945

RESUMO

The continuous cropping obstacle of Panax notoginseng is serious, and effective control measures are lacking. Soil disinfection with chloropicrin(CP) has been proven to be effective in reducing the obstacles to continuous cropping of other crops. In order to ascertain the effect of CP in the continuous cropping of P. notoginseng, this paper explored the influences of CP at different treatment concentrations(0,30,40,50 kg/Mu, 1 Mu≈667 m~2) on soil macro-element nutrients, soil enzyme activity, growth and development of P. notoginseng, and the accumulation of medicinal components. The results showed that CP fumigation significantly increased the content of total nitrogen, alkali-hydrolyzable nitrogen, ammonium nitrogen, nitrate nitrogen, and available phosphorus in the soil, but it had no significant effect on potassium content. The soil protease activity showed a trend of first increasing and then decreasing with the prolonging of the treatment time. Both the soil urease and acid phosphatase activities showed a trend of first decreasing and then increasing with the prolonging of the treatment time. The higher the CP treatment concentration was, the lower the urease and acid phosphatase activities would be in the soil. The protease activity was relatively high after CP40 treatment, which was better than CP30 and CP50 treatments in promoting the nitrogen-phosphorus-potassium accumulation in P. notoginseng. The seedling survival rates after CP0, CP30, CP40, and CP50 tratments in October were 0, 65.56%, 89.44%, and 83.33%, respectively. Compared with the CP30 and CP50 treatments, CP40 treatment significantly facilitated the growth and development of P. notoginseng, the increase in fresh and dry weights, and the accumulation of root saponins. In summary, CP40 treatment accelerates the increase in soil nitrogen and phosphorus nutrients and their accumulation in P. notoginseng, elevates the seedling survival rate of P. notoginseng, enhances the growth and development of P. notoginseng, and promotes the accumulation of medicinal components. CP40 treatment is therefore recommended in production.


Assuntos
Panax notoginseng , Fumigação , Crescimento e Desenvolvimento , Hidrocarbonetos Clorados , Solo
12.
Mol Pharmacol ; 100(3): 217-223, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34135098

RESUMO

Regulators of G protein signaling (RGS) proteins modulate signaling by G protein-coupled receptors. Using a knock-in transgenic mouse model with a mutation in Gαo that does not bind RGS proteins (RGS-insensitive), we determined the effect of RGS proteins on presynaptic µ opioid receptor (MOR)-mediated inhibition of GABA release in the ventrolateral periaqueductal gray (vlPAG). The MOR agonists [d-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO) and met-enkephalin (ME) inhibited evoked inhibitory postsynaptic currents (eIPSCs) in the RGS-insensitive mice compared with wild-type (WT) littermates, respectively. Fentanyl inhibited eIPSCs similarly in both WT and RGS-insensitive mice. There were no differences in opioid agonist inhibition of spontaneous GABA release between the genotypes. To further probe the mechanism underlying these differences between opioid inhibition of evoked and spontaneous GABA release, specific myristoylated Gα peptide inhibitors for Gαo1 and Gαi1-3 that block receptor-G protein interactions were used to test the preference of agonists for MOR-Gα complexes. The Gαo1 inhibitor reduced DAMGO inhibition of eIPSCs, but Gαi1-3 inhibitors had no effect. Both Gαo1 and Gαi1-3 inhibitors separately reduced fentanyl inhibition of eIPSCs but had no effects on ME inhibition. Gαi1-3 inhibitors blocked the inhibitory effects of ME and fentanyl on miniature postsynaptic current (mIPSC) frequency, but both Gαo1 and Gαi1-3 inhibitors were needed to block the effects of DAMGO. Finally, baclofen-mediated inhibition of GABA release is unaffected in the RGS-insensitive mice and in the presence of Gαo1 and Gαi1-3 inhibitor peptides, suggesting that GABAB receptor coupling to G proteins in vlPAG presynaptic terminals is different than MOR coupling. SIGNIFICANCE STATEMENT: Presynaptic µ opioid receptors (MORs) in the ventrolateral periaqueductal gray are critical for opioid analgesia and are negatively regulated by RGS proteins. These data in RGS-insensitive mice provide evidence that MOR agonists differ in preference for Gαo versus Gαi and regulation by RGS proteins in presynaptic terminals, providing a mechanism for functional selectivity between agonists. The results further define important differences in MOR and GABAB receptor coupling to G proteins that could be exploited for new pain therapies.


Assuntos
Subunidade alfa Gi2 de Proteína de Ligação ao GTP/fisiologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/fisiologia , Terminações Pré-Sinápticas/fisiologia , Receptores Opioides mu/fisiologia , Ácido gama-Aminobutírico/metabolismo , Analgésicos Opioides/farmacologia , Animais , Baclofeno/farmacologia , Feminino , Subunidade alfa Gi2 de Proteína de Ligação ao GTP/antagonistas & inibidores , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/antagonistas & inibidores , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Potenciais Pós-Sinápticos Inibidores/efeitos dos fármacos , Potenciais Pós-Sinápticos Inibidores/fisiologia , Masculino , Camundongos , Camundongos Transgênicos , Modelos Animais , Proteínas RGS/metabolismo , Receptores de GABA-B/metabolismo , Receptores Opioides mu/agonistas
13.
Angew Chem Int Ed Engl ; 60(30): 16388-16393, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34018292

RESUMO

Inorganic cesium lead halide perovskites offer a pathway towards thermally stable photovoltaics. However, moisture-induced phase degradation restricts the application of hole transport layers (HTLs) with hygroscopic dopants. Dopant-free HTLs fail to realize efficient photovoltaics due to severe electrical loss. Herein, we developed an electrical loss management strategy by manipulating poly(3-hexylthiophene) with a small molecule, i.e., SMe-TATPyr. The developed P3HT/SMe-TATPyr HTL shows a three-time increase of carrier mobility owing to breaking the long-range ordering of "edge-on" P3HT and inducing the formation of "face-on" clusters, over 50 % decrease of the perovskite surface defect density, and a reduced voltage loss at the perovskite/HTL interface because of favorable energy level alignment. The CsPbI2 Br perovskite solar cell demonstrates a record-high efficiency of 16.93 % for dopant-free HTL, and superior moisture and thermal stability by maintaining 96 % efficiency at low-humidity condition (10-25 % R. H.) for 1500 hours and over 95 % efficiency after annealing at 85 °C for 1000 hours.

14.
J Neurosci ; 38(41): 8737-8744, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30150362

RESUMO

Regulators of G-protein signaling (RGS) proteins negatively modulate presynaptic µ-opioid receptor inhibition of GABA release in the ventrolateral periaqueductal gray (vlPAG). Paradoxically, we find that G-protein-coupled receptor (GPCR) activation of G-protein-gated inwardly rectifying K+ channels (GIRKs) in the vlPAG is reduced in an agonist- and receptor-dependent manner in transgenic knock-in mice of either sex expressing mutant RGS-insensitive Gαo proteins. µ-Opioid receptor agonist activation of GIRK currents was reduced for DAMGO and fentanyl but not for [Met5]-enkephalin acetate salt hydrate (ME) in the RGS-insensitive heterozygous (Het) mice compared with wild-type mice. The GABAB agonist baclofen-induced GIRK currents were also reduced in the Het mice. We confirmed the role of Gαo proteins in µ-opioid receptor and GABAB receptor signaling pathways in wild-type mice using myristoylated peptide inhibitors of Gαo1 and Gαi1-3 The results using these inhibitors indicate that receptor activation of GIRK channels is dependent on the preference of the agonist-stimulated receptor for Gαo versus that for Gαi. DAMGO and fentanyl-mediated GIRK currents were reduced in the presence of the Gαo1 inhibitor, but not the Gαi1-3 inhibitors. In contrast, the Gαo1 peptide inhibitor did not affect ME activation of GIRK currents, which is consistent with results in the Het mice, but the Gαi1-3 inhibitors significantly reduced ME-mediated GIRK currents. Finally, the reduction in GIRK activation in the Het mice plays a role in opioid- and baclofen-mediated spinal antinociception, but not supraspinal antinociception. Thus, our studies indicate that RGS proteins have multiple mechanisms of modulating GPCR signaling that produce negative and positive regulation of signaling depending on the effector.SIGNIFICANCE STATEMENT Regulators of G-protein signaling (RGS) proteins positively modulate GPCR coupling to GIRKs, and this coupling is critical for opioid- and baclofen-mediated spinal antinociception, whereas µ-opioid receptor-mediated supraspinal antinociception depends on presynaptic inhibition that is negatively regulated by RGS proteins. The identification of these opposite roles for RGS proteins has implications for signaling via other GPCRs.


Assuntos
Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/metabolismo , Neurônios/metabolismo , Substância Cinzenta Periaquedutal/metabolismo , Proteínas RGS/metabolismo , Analgésicos/administração & dosagem , Animais , Baclofeno/administração & dosagem , Feminino , Agonistas dos Receptores de GABA-B/administração & dosagem , Locomoção/efeitos dos fármacos , Masculino , Camundongos Transgênicos , Neurônios/efeitos dos fármacos , Substância Cinzenta Periaquedutal/efeitos dos fármacos , Receptores de GABA-B/metabolismo , Receptores Opioides mu/agonistas
15.
Org Biomol Chem ; 17(34): 7854-7857, 2019 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-31408075

RESUMO

A copper-catalyzed DTBP oxidative dual C-H sulfurization has been developed for the direct thiocarbamation of imidazopyridines using a combination of elemental sulfur and formamides as carbamothioyl surrogates. NBS (bromo succinimide) was found to promote the thiocarbamation in good yields. This dual C-H sulfurization strategy enables access to a wide range of carbamothioyl imidazoheterocycles without the use of highly toxic phosgene.

16.
J Neurosci ; 37(3): 626-636, 2017 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-28100744

RESUMO

The rostral ventromedial medulla (RVM) is a relay in the descending pain modulatory system and an important site of endocannabinoid modulation of pain. Endocannabinoids inhibit GABA release in the RVM, but it is not known whether this effect persists in chronic pain states. In the present studies, persistent inflammation induced by complete Freund's adjuvant (CFA) increased GABAergic miniature IPSCs (mIPSCs). Endocannabinoid activation of cannabinoid (CB1) receptors known to inhibit presynaptic GABA release was significantly reduced in the RVM of CFA-treated rats compared with naive rats. The reduction in CFA-treated rats correlated with decreased CB1 receptor protein expression and function in the RVM. Paradoxically, the nonselective CB1/CB2 receptor agonist WIN55212 inhibited GABAergic mIPSCs in both naive and CFA-treated rats. However, WIN55212 inhibition was reversed by the CB1 receptor antagonist rimonabant in naive rats but not in CFA-treated rats. WIN55212-mediated inhibition in CFA-treated rats was blocked by the CB2 receptor-selective antagonist SR144528, indicating that CB2 receptor function in the RVM is increased during persistent inflammation. Consistent with these results, CB2 receptor agonists AM1241 and GW405833 inhibited GABAergic mIPSC frequency only in CFA-treated rats, and the inhibition was reversed with SR144528. When administered alone, SR144528 and another CB2 receptor-selective antagonist AM630 increased mIPSC frequency in the RVM of CFA-treated rats, indicating that CB2 receptors are tonically activated by endocannabinoids. Our data provide evidence that CB2 receptor function emerges in the RVM in persistent inflammation and that selective CB2 receptor agonists may be useful for treatment of persistent inflammatory pain. SIGNIFICANCE STATEMENT: These studies demonstrate that endocannabinoid signaling to CB1 and CB2 receptors in adult rostral ventromedial medulla is altered in persistent inflammation. The emergence of CB2 receptor function in the rostral ventromedial medulla provides additional rationale for the development of CB2 receptor-selective agonists as useful therapeutics for chronic inflammatory pain.


Assuntos
Bulbo/metabolismo , Dor/metabolismo , Receptor CB2 de Canabinoide/agonistas , Receptor CB2 de Canabinoide/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Benzoxazinas/farmacologia , Canabinoides/farmacologia , Canabinoides/uso terapêutico , Masculino , Bulbo/efeitos dos fármacos , Morfolinas/farmacologia , Naftalenos/farmacologia , Técnicas de Cultura de Órgãos , Dor/tratamento farmacológico , Medição da Dor/efeitos dos fármacos , Medição da Dor/métodos , Ratos , Ratos Sprague-Dawley , Receptor CB2 de Canabinoide/antagonistas & inibidores
17.
Environ Health Prev Med ; 23(1): 18, 2018 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-29769021

RESUMO

Depleted uranium (DU) has been widely applied in industrial and military activities, and is often obtained from producing fuel for nuclear reactors. DU may be released into the environment, polluting air, soil, and water, and is considered to exert both radiological and chemical toxicity. In humans and animals, DU can induce multiple health effects, such as renal tubular necrosis and bone malignancies. This review summarizes the known information on DU's routes of entry, mechanisms of toxicity, and health effects. In addition, we survey the chelating agents used in ameliorating DU toxicity.


Assuntos
Quelantes/farmacologia , Protetores contra Radiação/farmacologia , Urânio/toxicidade , Animais , Humanos , Inativação Metabólica , Urânio/metabolismo
18.
Zhongguo Zhong Yao Za Zhi ; 43(21): 4198-4202, 2018 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-30583617

RESUMO

With the rapid development of traditional Chinese medicine (TCM) in China as well as the implementation of the four most strict requirements, the quality of Chinese medicinal materials and decoction pieces had beem improved in recent years, however new problems and challenges were occurred. All the data of Chinese medicinal materials and decoction piece in special inspection,supervision test and evaluation inspection of drug administration department to were summarized and analyzed evaluate and analyze of the quality of Chinese medicinal materials and decoction pieces in 2017. On this basis, the relevant quality control strategies and suggestions were put forward for the relevant departments of China Food and Drug Administration to formulate and implement regulatory measures, furthermore to improve drug standards, and ensure the safety of medication.


Assuntos
Medicamentos de Ervas Chinesas/normas , Medicina Tradicional Chinesa , China , Vigilância de Produtos Comercializados , Controle de Qualidade
19.
J Neurosci ; 36(5): 1669-81, 2016 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-26843648

RESUMO

The ventrolateral periaqueductal gray (vlPAG) is a key structure in the descending pain modulatory circuit. Activation of the circuit occurs via disinhibition of GABAergic inputs onto vlPAG output neurons. In these studies, we tested the hypothesis that GABAergic inhibition is increased during persistent inflammation, dampening activation of the descending circuit from the vlPAG. Our results indicate that persistent inflammation induced by Complete Freund's adjuvant (CFA) modulates GABA signaling differently in male and female rats. CFA treatment results in increased presynaptic GABA release but decreased high-affinity tonic GABAA currents in female vlPAG neurons. These effects are not observed in males. The tonic currents in the vlPAG are dependent on GABA transporter activity and are modulated by agonists that activate GABAA receptors containing the δ subunit. The GABAA δ agonist THIP (gaboxadol) induced similar amplitude currents in naive and CFA-treated rats. In addition, a positive allosteric modulator of the GABAA δ subunit, DS2 (4-chloro-N-[2-(2-thienyl)imidazo[1,2-a]pyridin-3-yl]benzamide), increased tonic currents. These results indicate that GABAA δ receptors remain on the cell surface but are less active in CFA-treated female rats. In vivo behavior studies showed that morphine induced greater antinociception in CFA-treated females that was reversed with microinjections of DS2 directly into the vlPAG. DS2 did not affect morphine antinociception in naive or CFA-treated male rats. Together, these data indicate that sex-specific adaptations in GABAA receptor signaling modulate opioid analgesia in persistent inflammation. Antagonists of GABAA δ receptors may be a viable strategy for reducing pain associated with persistent inflammation, particularly in females. SIGNIFICANCE STATEMENT: These studies demonstrate that GABA signaling is modulated in the ventrolateral periaqueductal gray by persistent inflammation differently in female and male rats. Our results indicate that antagonists or negative allosteric modulators of GABAA δ receptors may be an effective strategy to alleviate chronic inflammatory pain and promote opioid antinociception, especially in females.


Assuntos
Dor Crônica/fisiopatologia , Substância Cinzenta Periaquedutal/fisiologia , Receptores de GABA-A/fisiologia , Caracteres Sexuais , Transdução de Sinais/fisiologia , Animais , Dor Crônica/etiologia , Relação Dose-Resposta a Droga , Feminino , Agonistas GABAérgicos/farmacologia , Temperatura Alta/efeitos adversos , Inflamação/patologia , Inflamação/fisiopatologia , Masculino , Medição da Dor/efeitos dos fármacos , Medição da Dor/métodos , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Ácido gama-Aminobutírico/farmacologia
20.
J Biol Chem ; 291(35): 18370-83, 2016 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-27402850

RESUMO

An important contributor to brain ischemia is known to be extracellular acidosis, which activates acid-sensing ion channels (ASICs), a family of proton-gated sodium channels. Lines of evidence suggest that targeting ASICs may lead to novel therapeutic strategies for stroke. Investigations of the role of ASICs in ischemic brain injury have naturally focused on the role of extracellular pH in ASIC activation. By contrast, intracellular pH (pHi) has received little attention. This is a significant gap in our understanding because the ASIC response to extracellular pH is modulated by pHi, and activation of ASICs by extracellular protons is paradoxically enhanced by intracellular alkalosis. Our previous studies show that acidosis-induced cell injury in in vitro models is attenuated by intracellular acidification. However, whether pHi affects ischemic brain injury in vivo is completely unknown. Furthermore, whereas ASICs in native neurons are composed of different subunits characterized by distinct electrophysiological/pharmacological properties, the subunit-dependent modulation of ASIC activity by pHi has not been investigated. Using a combination of in vitro and in vivo ischemic brain injury models, electrophysiological, biochemical, and molecular biological approaches, we show that the intracellular alkalizing agent quinine potentiates, whereas the intracellular acidifying agent propionate inhibits, oxygen-glucose deprivation-induced cell injury in vitro and brain ischemia-induced infarct volume in vivo Moreover, we find that the potentiation of ASICs by quinine depends on the presence of the ASIC1a, ASIC2a subunits, but not ASIC1b, ASIC3 subunits. Furthermore, we have determined the amino acids in ASIC1a that are involved in the modulation of ASICs by pHi.


Assuntos
Canais Iônicos Sensíveis a Ácido/metabolismo , Isquemia Encefálica/metabolismo , Acidente Vascular Cerebral/metabolismo , Animais , Isquemia Encefálica/fisiopatologia , Modelos Animais de Doenças , Concentração de Íons de Hidrogênio , Camundongos , Propionatos/metabolismo , Acidente Vascular Cerebral/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA