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1.
Acta Pharmacol Sin ; 2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36476808

RESUMO

Normal sensory and cognitive function of the brain relies on its intricate and complex neural network. Synaptogenesis and synaptic plasticity are critical to neural circuit formation and maintenance, which are regulated by coordinated intracellular and extracellular signaling. Growth hormone (GH) is the most abundant anterior pituitary hormone. Its deficiencies could alter brain development and impair learning and memory, while GH replacement therapy in human patients and animal models has been shown to ameliorate cognitive deficits caused by GH deficiency. However, the underlying mechanism remains largely unknown. In this study, we investigated the neuromodulatory function of GH in young (pre-weaning) mice at two developmental time points and in two different brain regions. Neonatal mice were subcutaneously injected with recombinant human growth hormone (rhGH) on postnatal day (P) 14 or 21. Excitatory and inhibitory synaptic transmission was measured using whole-cell recordings in acute cortical slices 2 h after the injection. We showed that injection of rhGH (2 mg/kg) in P14 mice significantly increased the frequency of mEPSCs, but not that of mIPSCs, in both hippocampal CA1 pyramidal neurons and L2/3 pyramidal neurons of the barrel field of the primary somatosensory cortex (S1BF). Injection of rhGH (2 mg/kg) in P21 mice significantly increased the frequency of mEPSCs and mIPSCs in both brain regions. Perfusion of rhGH (1 µM) onto acute brain slices in P14 mice had similar effects. Consistent with the electrophysiological results, the dendritic spine density of CA1 pyramidal neurons and S1BF L2/3 pyramidal neurons increased following in vivo injection of rhGH. Furthermore, NMDA receptors and postsynaptic calcium-dependent signaling contributed to rhGH-dependent regulation of both excitatory and inhibitory synaptic transmission. Together, these results demonstrate that regulation of excitatory and inhibitory synaptic transmission by rhGH occurs in a developmentally dynamic manner, and have important implication for identifying GH treatment strategies without disturbing excitation/inhibition balance.

2.
Chem Commun (Camb) ; 57(65): 8055-8058, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34291778

RESUMO

An efficient Pd-catalysed ß-C(sp3)-H arylation of diverse native amides with aryl iodides was developed. This protocol overcomes the necessity of the Thorpe-Ingold effect and features broad substrate scope and good functional group tolerance. The potential application of this protocol is collectively demonstrated by gram-scale synthesis and the synthesis of several bioactive molecules.

3.
Chem Commun (Camb) ; 57(37): 4544-4547, 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33956008

RESUMO

The Pd-cataylsed direct ortho-C(sp2)-H fluorination of aromatic ketones has been developed for the first time. The reaction features good regioselectivity and simple operations, constituting an alternative shortcut to access fluorinated ketones. A concise synthesis of anacetrapib has also been achieved by using late-stage C-H fluorination as a key step.


Assuntos
Cetonas/química , Oxazolidinonas/síntese química , Paládio/química , Catálise , Halogenação , Estrutura Molecular , Oxazolidinonas/química
4.
Chem Commun (Camb) ; 57(6): 765-768, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33355557

RESUMO

Herein, we report a novel strategy to access CH2F-containing ketones through Pd-catalysed ß-selective methyl C(sp3)-H fluorination. The reaction features high regioselectivity and a broad substrate scope, constituting a modular method for the late-stage transformation of the native methyl (CH3) into the monofluoromethyl (CH2F) group.

5.
Risk Manag Healthc Policy ; 13: 2291-2299, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33149709

RESUMO

While China's medical tourism industry is increasingly standardized and institutionalized, the relevant research assessing its legal risks is still absent. This paper aims to evaluate the risks of medical tourism from the legal perspective by exploring the conflict between the developing new practice and the existing legal system, summarizing the legal risks in medical tourism, and proposing measures and suggestions to mitigate such risks. The empirical research method is employed to review the legal risks in Boao Lecheng International Medical Tourism Pilot Zone, which is the pioneering project of China's development within the medical tourism industry. These research methods include collecting the latest medical tourism policies and regulations, judicial decisions, and on-the-spot investigation of the Pilot Zone. It is found that the legal risks in medical tourism activities are mainly concentrated in the administrative, civil and litigious legal relations, and concern four major subjects which are regulators, medical operators, tourism operators and consumers. For regulators, their administrative supervision has not been well in place before and during medical tourism activities, and there remain legal gaps in regulation. In terms of the protection of consumers' substantive rights, service providers and operators may evade their responsibilities by exploring the vacuum area during the transition from the old laws to the new ones, and the conflicting provisions exist between the special laws and general ones. Concerning the protection of consumers' litigation rights, there are many obstacles for consumers to safeguard their interests through litigation in a foreign land. In this paper, medical tourism activities are identified among four legal subjects and involving three types of legal risks, in the hope to help improve the overall understanding of medical tourism from the legal perspective, and put forward targeted suggestions on the potential legal risks.

6.
Chem Commun (Camb) ; 55(49): 7049-7052, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31143893

RESUMO

A palladium catalyzed selective C(sp3)-H arylation and acetoxylation of alcohols using a practical bidentate auxiliary were developed. Masked alcohols were selectively arylated at the ß-position with diverse aryl iodides for the first time. Moreover, an efficient and site-selective acetoxylation of various primary methyl, methylene, and benzylic C(sp3)-H bonds was performed by using cheap K2S2O8 as the external oxidant.

7.
Chem Commun (Camb) ; 55(14): 2019-2022, 2019 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-30564815

RESUMO

A novel palladium catalyzed highly para-selective C-H difluoromethylation of electron-deficient aromatic carbonyls was developed. Diverse substituted aromatic ketones and benzoates were selectively difluoromethylated at the remote para-site of carbonyl groups in moderate to good yields. Moreover, the difuoromethylation was also compatible with several complex bioactive molecules.

8.
Neuron ; 100(1): 183-200.e8, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30269986

RESUMO

Acute infection, if not kept in check, can lead to systemic inflammatory responses in the brain. Here, we show that within 2 hr of systemic inflammation, PDGFRß mural cells of blood vessels rapidly secrete chemokine CCL2, which in turn increases total neuronal excitability by promoting excitatory synaptic transmission in glutamatergic neurons of multiple brain regions. By single-cell RNA sequencing, we identified Col1a1 and Rgs5 subgroups of PDGFRß cells as the main source of CCL2. Lipopolysaccharide (LPS)- or Poly(I:C)-treated pericyte culture medium induced similar effects in a CCL2-dependent manner. Importantly, in Pdgfrb-Cre;Ccl2fl/fl mice, LPS-induced increase in excitatory synaptic transmission was significantly attenuated. These results demonstrate in vivo that PDGFRß cells function as initial sensors of external insults by secreting CCL2, which relays the signal to the central nervous system. Through their gateway position in the brain, PDGFRß cells are ideally positioned to respond rapidly to environmental changes and to coordinate responses.


Assuntos
Quimiocina CCL2/metabolismo , Inflamação/metabolismo , Neuroimunomodulação/fisiologia , Pericitos/metabolismo , Animais , Colágeno Tipo I/biossíntese , Cadeia alfa 1 do Colágeno Tipo I , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/fisiologia , Pericitos/citologia , Proteínas RGS/biossíntese , Receptor beta de Fator de Crescimento Derivado de Plaquetas/biossíntese , Transmissão Sináptica/fisiologia
9.
Neuron ; 94(6): 1155-1172.e8, 2017 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-28641114

RESUMO

The formation of functional synapses requires coordinated assembly of presynaptic transmitter release machinery and postsynaptic trafficking of functional receptors and scaffolds. Here, we demonstrate a critical role of presynaptic cadherin/catenin cell adhesion complexes in stabilizing functional synapses and spines in the developing neocortex. Importantly, presynaptic expression of stabilized ß-catenin in either layer (L) 4 excitatory neurons or L2/3 pyramidal neurons significantly upregulated excitatory synaptic transmission and dendritic spine density in L2/3 pyramidal neurons, while its sparse postsynaptic expression in L2/3 neurons had no such effects. In addition, presynaptic ß-catenin expression enhanced release probability of glutamatergic synapses. Newly identified ß-catenin-interacting protein p140Cap is required in the presynaptic locus for mediating these effects. Together, our results demonstrate that cadherin/catenin complexes stabilize functional synapses and spines through anterograde signaling in the neocortex and provide important molecular evidence for a driving role of presynaptic components in spinogenesis in the neocortex.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Caderinas/metabolismo , Adesão Celular , Espinhas Dendríticas/metabolismo , Neocórtex/metabolismo , Terminações Pré-Sinápticas/metabolismo , Células Piramidais/metabolismo , beta Catenina/metabolismo , Animais , Antígenos CD/metabolismo , Western Blotting , Proteínas de Transporte/metabolismo , Células HEK293 , Humanos , Imunoprecipitação , Camundongos , Camundongos Knockout , Neocórtex/embriologia , Proteínas do Tecido Nervoso/metabolismo , Ratos , Sinapses/metabolismo
10.
J Biomed Res ; 30(6): 502-509, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27924069

RESUMO

Increasing evidence suggests that the impaired neuroprotection of vesicular monoamine transporter 2 (VMAT2) contributes to the pathogenesis of Parkinson's disease. That has been linked to aberrant subcellular retrograde trafficking as strongly indicated by recent genomic studies on familial Parkinson's diseases. However, whether VMAT2 function is regulated by retrograde trafficking is unknown. By using biochemistry and cell biology approaches, we have shown that VMAT2 was stringently localized to the trans-Golgi network and underwent retrograde trafficking in non-neuronal cells. The transporter also interacted with the key component of retromer, Vps35, biochemically and subcellularly. Using specific siRNA, we further showed that Vps35 depletion altered subcellular localization of VMAT2. Moreover, siRNA-mediated Vps35 knockdown also decreased the stability of VMAT2 as demonstrated by the reduced half-life. Thus, our work suggested that altered vesicular trafficking of VMAT2 may play a vital role in neuroprotection of the transporter as well as in the pathogenesis of Parkinson's disease.

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